|Harry Harlick was an institution in the conveyor
industry, and an inspiration in the founding of FloStor. Harry
prepared the following information as a training manual for
engineers at Conveyors & Casters (Hamerslag Equipment), which
closed in 1985.
Significant advances have been achieved in conveyor technology
since this manual first appeared, though many of the basics remain
constant. This paper is provided as an introduction to the scope
considered by the FloStor professional sales engineers in
BASIC INTRODUCTION TO CONVEYORS
by Harry Harlick (1905-1987)
Section One: Gravity Conveyors
Section Two: Powered Belt Conveyors
Section Three: Live Roller Conveyors
Section Four: Chain Conveyors
Section Five: Supports
Section Six: Couplings
Section Seven: Accessories
Section Eight: Useful Formulas
Section Nine: Essential Information Required
Section Ten: A Brief History of Conveyor
The package conveyor business has been in existence for almost one
Material handling engineering, in an over-simplified, basically,
consists of determining "how a product should be moved from
one place to another, within the shortest allowable period of
time, for the least cost and with the least amount of manual
We hope that this publication will help to guide you to the best
possible solution to the many material handling problems, which
you may encounter.
It is extremely difficult to put in to writing the many years of
problem solving experienced by "old-timers" in this
industry, no two solutions are identical. This publication will
merely give you an idea of the uses of the many different types of
conveyors available, and, it will be up to you to sift through to
determine the best conveyor for your particular application.
Probably no other type of conveyor is applied to so many gravity
materials handling uses as roller and wheel conveyor, handling
various packaged materials efficiently for distances as short as 2
ft. or as long as 100 ft. or more. Any item from light bulbs to
bagged cement to heavy castings can be moved on gravity.
Most items are best handled on roller conveyor, however, wheel
conveyor may be substituted where a portable type gravity conveyor
is required, where light weight containers (38 lbs. per ft. in
steel, 18 lbs. per ft. in aluminum) are to be handled and where
semi-rigid filled multi-wall paper bags or bales are to be
handled. In general, roller conveyor should not be used for
conveying burlap bags of coffee beans, paper or cotton bags of
rice, cotton bags of flour or freshly filled paper bags of cement
because the type of material mentioned has a tendency to drape
Conveyors, when properly applied, confine the flow of materials
thus conserving valuable production and storage space. Frequently,
as in storage racks and production assembly lines, roller or wheel
conveyor are used for storage providing accessibility and easy
movement for processing or production. Breakage or damage is
generally minimized when the products are supported and restricted
during the travel on conveyor.
Supports should have some height adjustment and should be selected
for convenient height for personnel.
Skatewheel conveyor, as a rule, is generally used for handling
smooth bottom, wood, fiber or plastic containers. Semi-rigid
smooth bottom bags or bales may also be conveyed on some wheel
conveyor. If there is any doubt, the product and container should
be tested on an appropriate wheel conveyor. Such testing can help
determine the suitable grade.
Skatewheel conveyor is not recommended for handling cans with
chimes, open bottom crates, cleated containers or damp, soft,
soggy cartons. It is further not recommended for conveying
flexible filled bags or articles too small to span at least three
rows of wheels. Extremely heavy or soft-bottomed cartons may fold
around wheels and are therefore also not recommended for use on
From the Hytrol Catalog, you will note that skatewheel conveyor is
available in varied widths and varied wheels per foot patterns.
The selection of wheel conveyor is based upon the rigidity, size
and weight of package to be conveyed. The denser the wheel
pattern, the greater the range of cartons that can be handled on
such wheel conveyor.
Roller conveyor are also used for handling smooth bottom, wood,
fiber or plastic containers, crates (without wire binding), drums
and cans with chimes, kegs and long narrow packaged materials.
Gravity conveyors are used as a level push line or down grade by
utilizing the natural force of gravity. The use of gravity to
convey the selected class of packages to move by their own weight,
on a bed of rollers or wheels, is, perhaps, the most widely used
means for conveying in industry. The weights to be conveyed may
vary from a few ounces to several tons. For example, in department
stores, conveyors are used for handling light weight boxes of
hosiery and the same conveyors handle heavier boxes of dishes and
appliances. The selection of rollers is tailored to fit the
Roller conveyor is not recommended for conveying soft bottom
cartons or bags which will flex and fold or wrap around the upper
carrying portion of the roller and thus deter the free motion of
The degree of decline required will vary depending on whether the
bearings are dry or grease packed, on the ambient temperature (if
outdoors) and, in some areas, on humidity. The degree of decline
also depends on the specific application. The first package will
start rotation of the rollers. The second package if it followed
shortly, would benefit from this rotation and would travel a bit
faster than the first package and the third package even faster.
In the course of the day's production, trains of packages could be
traveling very fast on a degree of decline originally defined to
start package movement from rest. Retarding devices to help
control this situation are available.
A few elementary rules in the selection of roller conveyor are
offered as follows:
(1.) Packages to be handled should, in general, have smooth firm
bottom riding surface.
(2.) For normal conveying, at least three (3) rollers should be
under the package being conveyed at all times.
(3.) To select the proper roller, divide the weight of the package
by the number of rollers supporting the package. The load capacity
charts in the Hytrol General Catalog will help in your selection.
Other important areas to be considered are the actual items to be
conveyed as well as their size. While the load capacity chart
indicates that 50 lb. empty oil drums could be conveyed on
1.9" Dia. x 16 Ga. rollers, we would recommend the use of
2" Dia. x 12 Ga. rollers because of the greater wall
thickness in handling a steel drum.
The tolerances of the various components, which make up a roller
conveyor, may be such as to not present a perfect conveying
surface. Uniformly loaded packages, with some flexibility, will
distribute the weight approximately to each roller supporting the
package, whereas rigid packages may impose their entire load on a
reduced number of rollers. Wood or steel pallets may actually be
supported by only 50 per cent of the rollers under them. Select
from the Hytrol General Catalog a roller to suit the required load
capacity, taking into consideration the type of product being
handled, so that in the event the load is actually supported by
one-half of the rollers under the product. The rollers selected
will actually support this type of load. When roller lengths
exceed the catalog lengths, the axle deflection may be the
limiting factor in place of ball bearing capacity. Package roller
conveyors are not normally considered to be precision equipment,
and past experience indicates that the tops of all of the rollers
in the conveyor may not be at exactly the same height. Where an
excessive impact might occur in the loading area of a conveyor, it
is advisable to consider providing twice the number of rollers
normally required for conveying the package in this loading area
Nominal roller length is determined by the maximum width of the
commodity to be conveyed. Ordinarily, rollers would be two to
three inches longer than the widest package within the standards
listed in the Hytrol General Catalog. It is, however, permissible,
in certain package handling situations, for the package to extend
beyond the ends of the rollers if the rollers are mounted in a
high position in the side frames and provided the bottom of the
package does not flex and make contact with the side frames.
While it is difficult to recommend specific grades for various
materials to be conveyed on wheel or roller conveyer, we offer the
following suggested grades based upon average conditions. The
actual grade for a specific requirement should be determined by
test. Grades required for roller conveyer may vary because light
cartons with soft bottoms may require more grade than heavy
packages with hard bottoms.
Grades on curves are based upon the length of the outside rail and
grades on straight roller curves should be increased 25 to 50
percent than charted in fig. 7.
The average roller conveyor line handling 40 to 45 lb. packages
and equipment with ball bearing rollers requires a pitch of about
½" per lineal foot of travel, and for wheel conveyor the
pitch is about 3/8" per lineal foot of travel. The pitch will
increase or decrease according to the riding surface and the
weight of the commodity to be conveyed. Also, the use of sleeve
(sanitary) type bearings will affect the conveyor pitch.
Roller and wheel conveyor curves are made to match the straight
conveyor. The radii of any curve are dependent upon the length and
width of the package to be conveyed. The length and width of the
package also determines the width (between rails) of the curve and
generally, the width of the curve determines the width of the
adjacent connecting straight conveyor. If a package is
exceptionally long, as for florescent light tubes or cut flowers,
the adjacent straight conveyor might normally be excessively wide
for such a package, which condition, of course creates a costly
conveyor. The imbalance of this type of situation can be corrected
by using a narrower width curve and offset guard rails thus
permitting the package to overhang the rollers on the curve but
still keep the adjacent straight conveyor to a satisfactory width
and help keep the price of the required conveyor within
Wheel curves, because of the multiple rows of individual ball
bearing wheels, perform an excellent job of conveying rectangular
packages, as the individual wheels apply the necessary
differential action to keep the package centered as it traverses
the curve. Hytrol wheel curves are available in standard overall
widths to join to adjacent straight sections, with 45° and 90°
of curvature as standard.
Hytrol also has available tapered steel rollers, which also apply
the necessary differential action to keep the package centered as
it travels through the curve.
Straight roller curves are generally more satisfactory for
handling cylindrical packages rather than rectangular packages
because of the lack of the differential action required on this
type of roller conveyer. Since a package has a longer distance to
travel adjacent to the outer rail, the package in this type of
curve has a tendency to slip to the outer frame.
Double roller (curves with a center frame midway between the two
outer frames which splits the roller length) will convey a square
or rectangular package better than the single straight roller
curve because of the differential action of the two separate lanes
For best results, gravity curves should have a straight gravity
roller conveyor section at the infeed and the discharge ends of
the curve of minimum length equal to approximately 2/3 of the
length of the package.
Gravity curves are not recommended for accumulation of square or
rectangular packages. The line pressure will prevent the packages
from maneuvering the gravity curves and generally will force the
package against the outer guard thus blocking the free flow of
Gravity roller or wheel conveyor spurs are used for merging and
diverging of packages onto or off of a main line transportation
conveyor. The standard angles are 30°, 45° and 90°. The 45°
diverging unit is not normally recommended for automatic diverging
of packages but should be manually attended. Turning wheels should
be used as shown in the Hytrol General Catalog where spurs are
used in the converging application.
"Y" AND SPUR CURVE SWITCHES
These switches utilizing skate wheels provide a simple method of
diverting or converging products from one line to another as
described in the Hytrol General Catalog.
These are hinged sections used as gates and are available for
vertical movement of the section to provide access for personnel,
lift trucks or other equipment. They are available with or without
springs. The springs provide some assistance in lifting the
heavier gate sections. Horizontal gate sections with a pivot pin
on one end and caster supports on the opposite end are also
Thin wall rollers are perfectly satisfactory for most package
handling, but should not be used for handling extremely heavy
packages with steel strapping or filled steel drums regardless of
the indicated roller capacity. Thin wall rollers may be easily
bent, dented or cut, thus impairing their usefulness. The heavier
rollers such as 2 ½" Dia. x 11 Ga., 2 9/16" Dia. x 7
Ga., and 3 ½" Dia. x 9 Ga. are much better suited for this
Spring-Loaded axle construction is a Hytrol standard for:
1 3/8" Dia. x 18 Ga. Rollers using ¼" Dia. Galv. steel
axles 1.9" Dia. x 16 Ga. Rollers using 7/16" Hex. steel
axles 2" Dia. x 12 Ga. Rollers using 7/16" Hex. steel
axles 2 ½" Dia. x 11 Ga. Rollers using 11/16" Hex.
steel axles 2 9/16" Dia. x 7 Ga. Rollers using 11/16"
Hex. steel axles.
The spring-loaded construction which requires no hog rings or
cotter pins permits the customer to easily remove and relocate or
Other than wheel conveyor and 1 3/8" Dia. roller conveyor,
which have bar and hook type couplings, all other frames have butt
couplings for bolting sections together.
Hytrol stationary supports are available in light, medium and
heavy duty styles. Consult the Hytrol General Catalog for further
Poly-tier supports for support of multi-level conveyor lines are
also described in the Hytrol General Catalog.
Ceiling hangers are 5/8" Dia. painted steel rods with
Tripod stands are useful in setting up temporary conveyor lines,
using skatewheel and/or 1 3/8" Dia. x 18 Ga. roller conveyor.
For other types of supports, consult the Hytrol General Catalog.
Most overhead conveyor are usually required to be provided with
guardrails both sides. Curves as an option, may also be provided
with guards at the outside rail. Consult the Hytrol General
Catalog for various types.
Some frames are of steel galvanized, heat-treated aluminum, and
powdercoat painted steel. Hytrol green is our standard color.
You will at times, receive request to quote on replacement rollers
even for frames, which may have been furnished by other than
Hytrol. It is extremely important that exact information be
furnished. DO NOT GUESS.
1. Obtain roller diameter and gauge.
2. Check axle size; i.e. ¼" Dia., 7/16" Hex,
11/16" Hex. etc. on 1 3/8" Dia. x 18 Ga. rollers, Hytrol
furnishes ¼" Dia. Galv. steel spring loaded axles. Other
conveyor suppliers may use 5/16" hex axles.
3. Check to see if bearings are dry, grease packed or re-greasable.
4. Measure the exact distance between existing frames.
5. Measure the frame thickness, i.e. 12 Ga., 10 Ga., 3/16",
6. Some customers re-use their existing axles. Determine if axles
should be furnished. If the customer uses rollers with
spring-loaded axles, it is best that we furnish these complete.
If you have questions, the answers to which are not to be found in
Hytrol Catalogs, do not hesitate to call your master Hytrol
Distributor. He will obtain the information for you. Do not place
collect calls to your master distributor.
|SUGGESTED GRADES FOR ROLLER CONVEYER
INCHES PER FT
||5 to 10 lbs.
||6-1/2 to 7
||10 to 20 lbs.
||5-1/2 to 6
||20 to 50 lbs.
||50 to 100 lbs.
||20 to 50 lbs.
||50 to 100 lbs.
||100 to 250 lbs.
||2-1/2 to 3
Wood Shells (Empty)
||3 to 4 lbs.
||5-1/2 to 6
Wood Shells (Empty Bottles)
||15 to 20 lbs.
Wood Shells (Filled Bottles)
||45 to 50 lbs.
||20 to 125 lbs.
||4-1/2 to 5
||50 to 150 lbs.
||150 to 750 lbs.
||2-1/2 to 3
||50 to 100 lbs.
||100 to 250 lbs.
||250 500 lbs.
||2-1/2 to 3
POWERED BELT CONVEYORS FOR UNIT HANDLING ONLY
1. TYPES OF BELT CONVEYORS
A. Slider or roller bed
B. Horizontal - Reversing and non-reversing
C. Incline/Decline - reversing and non-reversing
D. Powered Feeder
E. Brake and Meter Belts
F. Metal "Piano Hinge" Belts
Belt conveyors are used for the controlled movement of a large
variety of both regular and irregular shaped products. They can
move light, fragile to heavy, rugged unit loads on a horizontal,
inclined or declined path within the limits of product stability
and the conveyor component capacities. The items being conveyed
are carried by the top surface of the belt.
The Hytrol General Catalog contains recommended uses for each
model of powered conveyor. This general catalog also lists
standard specifications as well as optional equipment for each
model. Study the Hytrol General Catalog carefully and often. There
is a world of good information to be gained from this practice.
Slider Bed is a belt conveyor, which utilizes a smooth surface bed
as the carrying surface for the belt. In the Hytrol General
Catalog this is a steel bed. In other applications, you may find
the carrying surface for the belt to be Masonite or other solid
Roller bed is a belt conveyor, which utilizes rollers as the
supporting surface of the belt. A good rule of thumb is to have at
least two rollers under the belt supporting the shortest item
being conveyed. This will give the item a reasonably smooth ride.
The selection of the size of the carrying rollers is a function of
the weight of the item being conveyed, the belt speed and the
manner in which the items are placed on the belt. Normal loading
would simply be a gravity or powered conveyor transferring a
package. This is a smooth transition such as packages transferring
from the discharge end of a gravity or powered conveyor to the
infeed end of this belt conveyor. If packages are hand loaded onto
the belt, there is a strong possibility that the packages might be
thrown and dropped onto the belt. We might consider more rollers
(twice the number normally supplied), heavier duty rollers or
slider bed in the area of impact only.
How do we select whether to offer the slider or roller bed
conveyor? If we have light loads within the load parameters
outlined in the Hytrol General Catalog, then, since cost is
usually an important factor, we would select the slider bed
conveyor. For heavier loads, again within the load parameters
outlined in the Hytrol General Catalog, we recommend the selection
of roller bed conveyor. 1.9" or 2" dia. rollers should
not be used at belt speeds in excess of 150 F.P.M. Also, very wide
conveyors require special consideration because of the possibility
of axle deflection within the rollers.
Special conditions, such as high or low temperature conditions,
and dirty or wet conditions should be brought to the attention of
your Master Hytrol Distributor prior to quoting. Relatively heavy
packages should not be transferred onto the middle of a belt
conveyor say one 20 feet or longer in length. Continual transfer
of the relatively heavy packages would have a tendency to push the
belt to the one side of the conveyor, and if these packages were
to enter the belt conveyor as a continuous flow, then could push
the belt over to the extent that the edge of the belt could
possibly be damaged at the drive or tail ends. The best type of
transfer described above would be with the use of 1ive roller
conveyors. However, if for some reason, the use of live roller
conveyors is not practical, then we should consider the use of the
three-pulley device normally furnished with the integral powered
feeder, at each side of the junction of the push-on or push-off
location. This provides a tight belt in the strategic location. A
thin strip of wood, plastic, or steel, along the one edge of the
belt opposite the push-on or push-off would also be helpful in
retaining the belt in the proper tracking position. The solutions
suggested herein are not to be construed as approval to accomplish
a specific described action, these are merely recommendations for
alleviating a non-recommended condition.
A single direction non-reversing belt conveyor of reasonable
length, may use a standard end drive with the 4" dia. drive
pulley. A reversing belt conveyor should use a center drive,
generally, with a larger than 4" dia. drive pulley,
particularly with longer conveyor lengths or heavy loads on the
belt. See the Hytrol General Catalog.
Horizontal belt conveyors usually consist of the following listed
1. An end or center drive which would include a gear motor and a
2. Either one or two end pulleys, depending upon the type of drive
used, or a power take-off device.
3. Bed sections, either slider or roller bed.
4. A suitable length of flexible belt.
5. Return idlers on approximately 10'-0" centers to support
the return strand of belt.
6. Floor or hanger supports on approximately 10'-0" centers.
7. Electrical controls and field wiring (optional).
Incline and decline conveyors: Consists of the same components
listed above except this unit would include a single or double
noseover, possible a feeder section, one of the two types offered,
and a "rough" surface belt on the incline (decline)
instead of friction surface belt.
Brake and Meter Belts
The Brake belt is used as a stop at the end of an accumulation
(Live Roller) conveyor and the Meter belt is used as the speed up
belt to obtain case separation. The Meter belt would normally have
the drive and the Brake belt would be slave driven from the Meter
belt through a power take-off similar to that used at the
chain-feeder section of an inclined belt conveyor. Meter belts
normally run 1 1/2 to 2 times faster than the Brake belt. Both
Meter and Brake belts are normally provided with a
"rough" top type belting, such as "Hilltopper".
As a rule of thumb, the total length of the combination of Brake
and Meter belts should be about 1/7 the total length of
accumulation conveyor with the Brake and Meter belts. The length
of the Meter belt, based upon the belt width would be the same as
a powered feeder section. As an example: If the total length of
accumulation conveyor with Brake and Meter belts were 84 feet,
then the total length of the combination Brake and Meter belts
would be 12 feet; then, subtracting the length of the Meter belt
would give us the length of the Brake belt portion.
Metal "Piano Hinge" conveyor: This is a hinged steel
belt, ideal for carrying hot and oily parts from punch presses,
forging machines, etc. This type of conveyor may be level,
horizontal or inclined "S" shaped as required. The
design and dimensional information is described in the Hytrol
Wire mesh belt conveyor: This type of belt conveyor, because of
the open mesh, permitting the free flow of air, is excellent for
conveying hot or cold materials too hot or too cold to handle on
standard duck or PVC belts. The wire mesh belt can travel on
rollers or longitudinal runners covered with a dense plastic
material. The pulleys are generally cast with multiple teeth to
grip the mesh of the belt. Under some circumstances, the pulleys
can be standard rubber or neoprene lagged to grip the underside of
the wire mesh belt. Since it carries no load, the return strand
can also be supported by return idlers or by longitudinal runners.
Portable conveyors: The Hytrol General Catalog lists a large
number of portable belt conveyors. A portable conveyor is one,
which can be rolled from one position to another on caster wheels.
In addition, Hytrol offers a large variety of skatewheel conveyors
or 1 3/8" diameter roller conveyors with tripod stands and
portable castered supports. The catalog also lists various
extendible portable gravity conveyors, the descriptions of which
are well covered in the Hytrol General Catalog.
Caution areas for belt conveyors: A reversible belt conveyor has
been and will, no doubt, continue to be an item with which the
operating results will be in doubt until the conveyor is installed
and tested under no load and load conditions. Theoretically, a
belt conveyor will not operate reversibly unless all revolving
surfaces in contact with the belt are square with the frame or
unless the belt tracking devices are properly adjusted. Conveyors
& Casters employs capable Millwrights who have had extensive
experience in installing and testing the reversible belt
When a reversible belt starts to give belt-tracking trouble, even
after it has worked for a number of years, random adjustments
should not be made. It could easily get out of hand if someone who
does not know the proper procedure tries to correct the trouble by
making various adjustments. If, after operating satisfactorily for
a number of years, it must be assumed that something must have
happened to cause the belt to run off to one side.
Before trying to make any adjustments the following points should
1. If a new belt has been installed, has the belt been cut
perfectly square or has it been cut on a cambor?
2. Has the conveyor frame itself been pushed out of line by lift
trucks or other devices?
3. Have adjustments been made on the return idlers or the end
pulleys by mechanics inexperienced in solving such problems?
4. Have the bolts which hold the flange bearings pulley shafts
become loose and shifted from their original positions?
5. Have any of the roller conveyor bearings or flange bearings
become so worn as to effect their original square alignment?
6. Have any of the return idler supporting clips or mountings
become loose so as to affect the alignment of the belt?
It is quite possible, if all of the above items are carefully
checked and any corrections properly made that the belt will then
track in its original squared up position in both directions. The
belt tracking conditions should be approached by correcting those
things which may have gone wrong due to the age of the conveyor
components thus returning it as near as possible to its original
The practice used in tracking a one-direction belt cannot be
applied to a reversible belt conveyor. All moving parts in contact
with the belt must be squared up with one another and all with the
frame for the single direction only. Do not class a reversible
belt conveyor in the same category as a single or one direction
belt conveyor so far as installation time is concerned. The
reversible belt conveyor does take considerably longer because of
all the variable conditions herein described to install properly.
Belting: Belting manufacturers have come a long way in the
manufacture of excellent quality belting. For example, most
belting for level conveyors furnished by Hytrol will probably be
PVC (poly vinyl chloride) machine woven nearly impervious to most
liquids and ambient temperatures. The "Hilltopper" belt
has a rough surface bonded to the PVC base. Other belts, some
impervious to food oils and some approved by USDA (US Department
of Agriculture) for food handling are also available. Check with
the Hytrol Master Distributor for belt recommendations for
specific special applications.
Motors: Hytrol Conveyor Company manufacturers their own gear
reducers for most conveyor applications. The integral width gear
reducer for "V" built variable speed drives and the
"C" face reducer to receive any "C" face
electric motor. Motors are available in open drip proof and
totally enclosed, either single or 3 phase. In the Western States,
we mostly use totally enclosed motors. Hytrol reducers are
available in commercially standard speed ratios of 10 to 1, 20 to
1, etc. Hytrol Conveyor Company can provide variable speed motor
drives at additional charge. They have one which is.2.7 to 1 ratio
and another, which is 6 to 1 ratio. As an example, this means that
the 2.7 to 1 ratio can have, lets say, a low speed range down to
10 F.P.M. and can be adjusted up to a maximum of 27 F.P.M. On the
6 to 1 ratio we can have, the low speed at 10 F.P.M. and the
maximum speed at 60 F.P.M. We can adjust the low speed instead of
using 10 F.P.M. to say 15 F.P.M. with the high-speed range greater
than that stated above, within the speed capacity of the rollers,
if the conveyor is a roller bed.
Many Hytrol portable conveyors are normally furnished with single
phase motors and with reversing drum switch all for 115 volts.
This reversing drum switch has no overload protection. When 3
Phase motors are used, then the push-button controls operating
on.115 Volt single phase which in turn actuates a 3 phase magnetic
starter which does have overload protection in the form of heater
coils. If the motor, for any reason, is overloaded and starts to
heat up in excess of its rated capacity, the heater coil
automatically will be destroyed, which, in turn, interrupts the
electrical current to the motor. The motor stops undamaged and the
condition which caused the heater coil to be destroyed, can be
corrected, a new coil replaced in the starter and the system
started up once again. It is extremely important that the proper
coil size be used. Other than portable conveyors, Hytrol does not
normally furnish electrical controls unless specifically requested
to do so, at additional charge. Limit switches, photo cells and
other controls can also be furnished at additional charge.
Conveyors & Casters is proud to report they have "in
house" capabilities to prepare sophisticated electrical
wiring schematic drawings, at additional charge and can arrange
with qualified local electrical contractors in order to provide a
LIVE ROLLER CONVEYORS FOR UNIT HANDLING ONLY
Types of Live Roller Conveyor:
A. V-Belt Driven
B. Flat Belt Driven
D. Single strand roller chain driven
E. Roller to roller chain drive
F. Roller Slat Conveyor
Live roller conveyors, because of the relatively low coefficient
of friction between the bed rollers and the items conveyed, are
used in preference to belt conveyor where:
1. Temporary utilization of the items being conveyed is a
2. Items are stopped momentarily such as traffic control points.
3. Items must be turned, say 90° on the conveyor.
4. An air operated or manual stop is injected into the line so
that the item may be inspected or some operation performed while
the conveyor remains in motion.
5. Side loading or unloading is required involving a sliding
motion across the bed rollers.
Belt driven live roller using regular friction surface rubber
filled belting is not recommended for use in high environmental
temperature extremes. Rubber can become sticky and soft at
temperatures exceeding 150°F, and this belting can stiffen
considerably and crack in the minus zero range. PVC or cotton
belting is a considerable improvement in the range described
above. Check with your Master Hytrol Distributor for special cold
Keep in mind, that the belt travels in a direction opposite to the
items being conveyed. This is unlike a belt conveyor where the
items are being carried directly upon the belt, so they both go in
the same direction.
V-Belt driven live roller conveyor is that type where a single
strand of V-belt is under the roller bed, on one side of the
rollers, adjacent to the side-frame and is powered in a direction
opposite to that of the items being conveyed. We recommend this
type of conveyor for light and medium duty loads. This type of
conveyor is not recommended for use where moisture or oily
conditions may exist. A very light contact with the underside of
the bed rollers is all that is required to keep the items being
conveyed in motion. This type of conveyor may also be reversible.
Belt driven tapered roller curves generally give good package
conveying action. The tapered roller presents a true conveying
surface on a curve giving the correct radial speed along the full
length of each roller. The curve radius along with the taper on
the roller which comes to a common focal point causes the package
to leave the curve in much the same position in which it entered.
For best results, there should be live rollers, a minimum of 2/3
of package length at the entry and at the discharge ends of the
Two rail curves with straight rollers are not normally recommended
for use as a live roller curve because both rows of rollers must
be powered separately and with a different speed in order to
obtain some semblance of differential action. Under some
conditions, the center rail may be move off center, closer to the
outer rail with the longer rollers powered.
Flat Belt driven live roller conveyor is that type where a flat
width of belt is under the roller bed, generally in the center of
the conveyor, but can be mounted off-of-center adjacent to the
side frame if required. Because of the greater contact surface at
the underside of the roller bed, this type of conveyor is
recommended for handling medium to heavy duty loads, where
moisture, hot, dirty or oily conditions do not exist. Again, the
pressure rollers which snub the driving belt to the underside of
the bed rollers are set to a minimum, just enough to convey the
load, yet allow belt slip without undue wear or stress on the gear
motor when the loads are momentarily blocked.
The above described conveyor design cannot be incorporated into a
roller bed curve, and another type of live roller curve must be
utilized where a curve is necessary.
Ripple Belt conveyor is one utilizing a belt, which varies in
thickness at regular intervals along the full length of the belt.
It is set so that the thicker portions of the belt make contact
with the underside of the bed rollers. If the ripples are
relatively far apart, only a few are in contact with the bed
rollers. This makes for a fairly inexpensive live roller with
reduced line pressure under blocked load conditions.
Controlled gravity live roller is similar, in construction, to
flat belt or V-belt driven live roller conveyor, except that the
conveyor is sloped at a grade just sufficient to allow the items
to convey by gravity. On the flat belt conveyor the snubbing
rollers are spaced further apart than the standard horizontal live
roller. Since gravity is the driving force of the items being
conveyed, the snubbing pressure is light enough to simply prevent
the rollers from turning at excessive speeds particularly when
trains of items coming one after another are being conveyed.
Hytrol Zero-Pressure Live Roller Conveyor is very completely
described in the General Catalog under the headings 190-ACO and
190-ACOC. This is a full length drive shaft arrangement, with each
thread roller driven by a urethane o-ring from a 1.9"
diameter longitudinal drive roller. The 190-ACOC curves, which are
slave driven from the adjacent 190-ACO, is designed for
applications that require accumulation of products without a
build-up of line pressure. In addition, Hytrol has developed the
model 190-ACA, a flat belt drive zero-pressure conveyor. In all
zero-pressure live roller, the conveyor length is divided into
zones, the length of each is greater than the maximum package
length. Zero-pressure is achieved since the packages never touch
Single strand chain driven live roller is a medium duty live
roller conveyor, ideal for conveying hot or oily items, or items
subject to wash down. In this type of live roller, "Type
A" plate sprockets are welded to one end of each roller. Care
must be taken that the dimension form the end of each roller is
identical to keep the roller chain in a straight path. In this
type of conveyor, the roller chain which powers each roller only
makes contact with just one or tow teeth of the sprocket. The
sprockets and the chain are completely enclosed by the chain guard
which sometimes acts as a hold down for the upper strand of chain.
Rack tooth sprockets must be used for this type of conveyor. If
rollers used are a large diameter and would necessitate a greater
roller spacing than desired, then idler (non-powered) rollers may
be spaced between each driven roller.
Because the chain guard on chain driven live roller conveyor forms
a guardrail on the one side of the conveyor, items can only be
transferred to and from the opposite side of the conveyor. Hytrol
has developed a chain crossover, which simply crosses the chain
over to the opposite side on a slave driven arrangement when items
must be transferred to or from the driven side. Access is
available from the one non-powered side only.
Single strand chain driven live roller curves can also be supplied
using a side bow chain, especially designed to bend around a
Roll to roll chain driven live roller is a heavy-duty live roller
conveyor for use under the same conditions as for single strand
live roller. In this instance, two type "A" sprockets
are welded to one end of each roller. The roller chain then makes
a complete loop around each pair of adjacent roller sprockets.
With a greater number of sprocket teeth in contact with the roller
chain, more power can be transmitted to and through each roller.
Rack tooth sprockets must not be used on this type of conveyor.
Roll to roll chain driven live roller curves can also be supplied.
A heavier duty roll to roll chain driven live roller conveyor
utilizing two "B" type sprockets attached to the
extended shaft on the outside of one side frame accomplishes the
same as described above and permits the use of smaller drive
sprockets, thus enabling us to keep the rollers to reasonable
closer centers. This type of live roller can also allow access
from either side of the conveyor provided the chain guard which
covers the outboard row of sprockets does not project above the
top of the conveyor side frame.
Roller slat conveyor utilizes extended pitch bushed roller chain
with oversize rollers rolling in tracks adjacent to the outer
rails. Using ball bearing rollers with the hexagon axles longer
than normal; these axle ends pass through the hexagon broached
bushings of the chain and are generally cottered at both ends on
the outside of the chain.
On a blocked load, the conveyor continues to run and the ball
bearing rollers simply roll under the blocked load. The line
pressure thus is kept to a reasonable low level.
This roller slat conveyor is an extremely heavy type of conveyor,
and must be assembled at the job site as the assembled conveyor
rollers in the chain are much too heavy to handle as an assembled
unit. This is also a fairly expensive type of live roller and is
used only under special conditions; such as heavy duty type for
filled oil drums or perhaps for newspaper mail rooms where the
blocked load of newspapers permit the roller slat to run under the
newspapers without damage.
Except for Hytrol's Zero-Pressure 190-ACOC conveyor, under no
circumstances should curves be used for accumulation of square or
rectangular items. Cylindrical items only are permissible. The
very nature of a square or rectangular conveyor would cause the
corner of one container to dig into the corner of another.
Powered curves should not be warped because of the difficulty in
providing power to the individual rollers of a warped curve.
There is a wide variety of chain conveyor classified into four
A. Sliding chain conveyors.
B. Rolling chain conveyors.
C. Pusher Bar chain conveyors.
D. Vertical chain conveyors.
Sliding chain conveyor: This is the type of conveyor consisting
generally of two parallel strands of chain. For light unit loads
and for short distances, the chain can be a double pitch roller
chain with the standard small rollers running in a track lined
with high density low co efficient friction plastic material. For
heavier loads, it is best to consider a heavy duty cast pintle
chain which will also run in a channel track lined with a high
density, low coefficient of friction plastic material of which
there are many available today. The sliding chain conveyors carry
the loads on the chains and the bottom of the chains are in low
frictional contact with the track.
Rolling chain conveyors: This is the type of conveyor, which
utilizes generally, two parallel strands of double pitch roller
chains (sometimes three strands), with the rollers running on key
stock material of width to fit between the side plates of the
roller chain. Again, this design is used for fairly light loads
and for short conveyors. For heavier loads, we can use the double
pitch chain with oversize rollers where the rollers are greater in
diameter than the width of the chain side plates thus the rollers
do project below the side plate of the chain. This rolling
friction design utilizes a lower horsepower requirement and thus
can be used for longer runs of chain driven conveyor. The loads
are carried on attachments, which raise the load above the chain
A slat or apron conveyor using steel or wood slats or even a ball
bearing conveyor rollers between the two parallel strands of
roller chain actually fits the category description for roller
slat conveyor previously described. In the use of steel or wood
slats, heavy loads can be carried under such conditions where
perhaps a PVC or a rubber belt could not possibly be utilized.
Also another type of sliding chain conveyor, which utilizes single
strand of link chain riding in a plastic lined track in the center
of the conveyor. Outboard of this center track on both sides to
the outer frame rails are gravity rollers or wheels spaced on
suitable centers compatible with the container being handled. The
link chain, which is powered, projects slightly above the side
rollers and is the driving force which carries the containers
while the side rollers or wheels merely balance the load. Some
advantages of this conveyor are:
1. Excellent for wash down conditions.
2. A single drive can be used to convey on the level, up an
incline, down a decline, around a curve, etc.
Some disadvantages are that it can only be used satisfactorily for
fairly light loads and inclines and declines cannot be too steep,
probably not more than 15 degrees.
Pusher Bar Conveyors are similar in design to the horizontal slat
conveyor in that we have two outboard strands of roller chain
adjacent to the side frames. We can use an attachment on the chain
to which we can fasten an angle, a flat bar or a round rod. This
angle, flat bar or rod is the pusher bar. Under the chain track
and between the side frames we have a slider bed. The units to be
conveyed will slide on the slider bedplate and will be pushed by
the pusher bars. The spacing of the pusher bars must be such as to
permit the conveyed items to fit in between. Some advantages of
this type of conveyor are:
1. Can convey heavy items up much steeper inclines than
conventional Hilltopper belt.
2. Can handle wire bound crates or bales of hay.
3. Can handle heavy burlap or cotton bags of flour, rice or green
coffee items which might be difficult to incline or decline at
angles in excess of 25 degrees on Hilltopper belt.
Some disadvantages are:
1. The height of the pusher bars above the slider bed must be such
that the containers will not fall forward or backward. This limits
the variation of box sizes.
2. The timing of containers is critical so two containers cannot
try to get between the two pusher bars simultaneously.
3. This type of conveyor can definitely not be used with sheet
polyethylene bags, as the frictional heat generated would create
holes in these bags.
Vertical chain conveyors can be designed for use to handle
individual cartons as well as full pallet loads. The design can be
similar to a dumb waiter style where the unit is a reciprocating
lift handling one unit at a time or can be a continuous lift with
flights attached to side roller chains. Each flight can handle one
unit, therefore the flight spacing vertically depends upon the
maximum height of the unit being handled.
Types of supports are listed as follows:
A. Tripod stands.
B. Portable castered supports.
C. Stationary floor supports.
D. Polytier supports.
E. Ceiling hangers.
F. Under trussing.
Tripod Stands are used for temporary installations. It consists of
a "T" shape upper top which fits under the cross brace
of wheel conveyor or SSR/SAR roller conveyor. The bottom part of
the "T" slips into a 3-legged tripod and is held in the
height position by a friction grip.
Portable castered supports utilizes the "T" portion of
the tripod stand which slips into a vertical pipe with a flat
cross piece at the bottom to which are attached casters for
Stationary/Floor supports consists of two pivot plates attached to
the underside of the conveyor section, to which are attached
formed steel channel legs. Adjustable feet are attached to the
bottom of the legs. The feet are provided with holes for fastening
the support to the floor. Stationary floor supports may also be
fitted with castered supports.
Polytier supports are designed to provide sturdy supports for
multi-level conveyor lines, utilizing formed steel channel
uprights with 1 1/2 inch diameter pipe cross braces to which the
conveyor lines are attached with "U" shaped brackets.
Knee braces, which are angled between the upright leg and the
underside of the conveyor frame, provide increased longitudinal
Ceiling hangers consist of 5/8 inch diameter painted steel rods
fastened to the 1 1/2 inch diameter cross pipe mounts on the
underside of the bed sections and the upper portion is fastened
either to ceiling beams or metal clips which in turn are fastened
to ceiling beams.
Types of couplings are as follows:
A. Hook and rod normally used on conveyors at temporary
installations. These are only provided on wheel or SSR/SAR roller
conveyors. Hook and rod couplings can be used in fixed
installations with stationary floor supports.
B. Butt Couplings used in fixed installations and are attached to
each corner of the bed section for bolting the sections together.
1. The traffic cop is a mechanical device with spring loaded arms
and cams located at the junction of two powered conveyor lines and
prevents the flow of carton traffic on one line from interfering
with the flow on the adjacent line. In other words, it eliminates
collision of cartons arriving at the junction simultaneously. If
possible, the two conveyors should be of the live roller type.
2. Case stops of blade and roller type are available as hand
operated and foot operated. The air cylinder operated type is
available as the roller type only. The blades or rollers are
located between the rollers on the live roller or gravity
conveyors only. They cannot be used in the middle of a belt
conveyor, for obvious reasons.
3. Turning wheels are used at the junction of a branch line to a
main line to insure proper carton orientation and to prevent
cartons from falling off the conveyor during the course of the
4. Angle end stop is mounted to the ends of the conveyor side
frames to prevent the continued flow of cartons on the conveyor
from falling off of the conveyor.
5. Guard rails are available in many shapes and sizes. Their
purpose is to prevent cartons from falling off the conveyor and
they must be used on all overhead conveyors.
6. Ball transfers consist of a large steel ball riding on a bed of
smaller balls all contained within a steel stamping to hold and
support the configuration together. We utilize a pattern
arrangement of ball transfers on a steel bed in a conveyor line to
permit cases to be manually positioned or rotated easily.
7. "Y" Switch of skatewheel design provides a simple
method of converging or diverging cartons. Consult the Hytrol
General Catalog for a description and photo.
8. Spur curve switch of skatewheel design also provides a simple
method of converging or diverging cartons. Again consult the
Hytrol General Catalog.
9. Carton push-offs come in various sizes and designs. All
push-offs simply push a carton at right angles to the original
direction of flow. The overhead push-off is a high speed air
cylinder actuated unit which can cycle up to 40 times per minute
and can push carton with weights up to a maximum of 150 lbs. The
medium duty horizontal push-off can push up to 300 lbs. and the
heavy duty over 300 lbs. A horizontal push-off will cycle
considerable less than the 40 cycles per minute available with the
10. Pop-up wheel diverter is specifically designed for use in the
190-ACC Accumulating conveyor. It provides for high speed
automatic diverting of cartons onto a 30 degree spur. It consists
of three rows of 2 1/2 inch diameter powered wheels, the mechanism
of which is raised and lowered pneumatically. It can handle
cartons of 150 lb. maximum weight up to 40 cycles per minute
maximum. A description and photo is in you Hytrol General Catalog.
11. High speed diverter uses a powered diverting belt and can
handle maximum weight cartons of 200 lbs. each. It is best used
for rapid singulation and diverting. See the Hytrol General
12. The powered turn-table is used when two parallel lines must be
close together. The minimum turning radius is much less than our
standard roller or even powered curves.
13. The manually operated turn-table simply consists of a given
length of conveyor on a revolving mechanism, which allows the
conveyor to be manually turned and positioned for
"inline" flow of products. It is used where curves are
unable to fit into the system. Pneumatic and motor indexing
turntables are also available.
14. Plows can only be used to divert to a 30 degree spur from a
main line. In addition to the manual1y positioned plow, Hytrol has
the pneumatic positioned plow as well as the V-belt motorized and
pneumatic positioned unit.
15. Manual Vertical Gates for gravity lines are available and the
maximum length of gate is determined by the weight of the conveyor
to be lifted. Gates are used to provide access through a conveyor
16. Spring Balanced Gate allows the use of heavier gates than with
manual gates with the use of tension springs adjusted to provide a
minimum weight lift.
17. Horizontal Swing Gates with castered supports can also be
supplied. The conveyor in this instance may be powered as well as
18. Jump transfers are devices set between rollers of gravity or
live roller conveyor to transfer the product at right angels from
the conveyor. They perform the same function as the push-offs
under more controlled circumstances. Hytrol has available the
skatewheel transfer, the powered V-belt transfer and the powered
chain transfer. In most instances, air bags are used to raise and
lower the transfer.
CONVEYOR - HORSEPOWER CALCULATIONS
To determine the horsepower required for a belt conveyor, it is
first necessary to determine the total belt pull. The belt pull,
in turn, is based upon the live load plus the weight of all moving
parts, multiplied by the coefficient of friction. The information
required is listed as follows:
1. Size and weight of each package.
2. Belt speed.
3. Number of bed rollers times the weight of each roller.
4. Number of return idlers times the weight of each roller.
5. Total weight of all of the belting.
6. Total weight of all pulleys.
7. On inclines (or declines), the additional belt pull is required
for that portion of weight on the conveyor on the incline (or
decline). This is equal to the weight of all packages on the
incline (or decline) times the sine of the angle.
|COEFFICIENT OF FRICTION
|Type of Conveyor
|Roller Bed - Ball Brgs.
|Roller Bed - Wood Sleeve
|Steel Slider Bed with
|Steel Slider Bed with
|Belt Driven Live Roller
A. Live Load
The live load is the actual load on the conveyor at
a given time. First we multiply the weight of each package times
the number of packages per minute; we divide this total by the
belt speed in feet per minute. This gives us the live load per
foot which when multiplied by the total length of conveyor results
in the total live load.
B. Weight of Belt
This includes the actual weight of both the
TDP and bottom runs, in other words, the belt on top of the slider
bed or carrying rollers and the return strand. See attached belt
|WEIGHTS OF COMMONLY USED BELTS
||Weights per inch width x 12" long
|3 Ply Solid Woven
|Black PVC - 90
|Balck PVC - 120
|Black or White IWP-3
|Brown - 3 Ply Neoprene
- Ruff tip
How To Obtain Approximate Belt Lengths For Various Conveyors
NOTE: These formulas are for calculating horsepower only, not for
determining replacement lengths of belts. *OAL = Overall Length
||TYPE OF DRIVE
||4" or 8" Dia. End Drive
4" or 8" Dia. Center Drive
|2 x OAL + 1' - 0"
2 x OAL + 3' - 6"
||Same as for "TA"
||8" End Drive, 4" or 6" Dia.
8" Center Drive, 4" or 6" Dia. Tail Pulleys
|2 x OAL + 1' - 0"
2 x OAL + 3' - 6"
||8" End Drive, 4" or 6" Dia.
8" Center Drive, 4" or 6" Dia. Tail Pulleys
|2 x OAL + 6"
2 x OAL + 3' - 0"
||12" or 16" End Drive
12" or 16" Center Drive
|2 x OAL + 3' - 0"
2 x OAL + 6' - 0"
||8" Center Drive
||2 x OAL + 3' - 6"
||12" or 16" Center Drive
||2 x OAL + 6' - 0"
Add 2’ – 0” for double nose over on incline belts.2.
Add 2’ – 6” for underside take-ups for all above,
except 25 RB.3. Add 6’ – 6” for underside take-up for
25 RB.4. Add 2 x OAL + 6” for chain driven power
feeders.5. Add 2 x OAL + 2’ – 6” for integral type
C. Weight of Rollers: Include the total weight of all bed rollers
and return idlers. When slider bed construction is use, include
only the weight of the return idlers.
||ROLLER WEIGHTS (IN POUNDS)
|1.9 x 16 Ga.
|1.9 x 9 Ga.
D. Coefficient of Friction: Use the coefficient of friction which
corresponds to one of the sketches pictured below. The percentages
shown are for all types of belting on roller conveyor. Rubber
covered belting is not normally recommended for slider bed
construction, except for short lengths and light loads.
1. Roller bed with return idlers Coef. of friction
a. Ball bearings 5%
b. Wood burning 10%
2. Roller bed with steel slider return Coef. of friction
a. Roller bed with slider return & F.S. x F.S. belt 30%
b. With PVC belt 25%
3. Steel slider bed with return idlers Coef. of friction
a. With F.S. x F.S. belt 30%
b. With PVC belt 25%
4. Steel slider bed with steel slider return Coef. of friction
a. With F.S. x F.S. belt 35%
b. With PVC belt 30%
E. Weights of All Pulleys: Include total weight of all drive
and idler pulleys, snub rollers, end and take-up pulleys.
|PULLEY WEIGHTS (IN POUNDS)
F. Inclines or Declines: When all or any part of a conveyor is
inclined or declined, an added belt pull is applied. This
additional belt pull is obtained by multiplying the total live
load on the inclined (or declined) portion by the sine of the
|SINE OF ANGLES
Belt pull for inclined portion = Live Load on incline times sine
of angle or incline.
G. Two and Three Pulley Device: Add 5% of the Live Load
preceding the device.
H. Deflectors: To accurately determine the total belt pull, add
30% of the weight of the heaviest package being diverted. We
normally do not recommend diverting from belt conveyors except for
light weight packages.
Belt pull equals weight of heaviest package times coefficient of
friction for specific belting being used. Use only a smooth top
I. Mechanical Traffic Cop: Add 30% of the weight of the maximum
number of packages which will be held back by the traffic cop arm.
The maximum weight of the total number of packages should never
exceed 250 lbs.
Horsepower = Effective belt pull x conveyor speed (feet per
33,000 x .85 x .95
1. One horsepower is defined as the power required to move 33,000
lbs. A distance of one
foot in one minute.
2. .85 allows for 85% for worm gear efficiency. Hytrol gear boxes
use worm gears.
3. .95 allows for the roller chain drive efficiency.
Example (Level RB Belt Conveyor)
1. Package weight = 45 lbs.
2. No. of packages per minute = 20
3. Belt speed = 65 FPM
4. Bed rollers = 12" CTRS. (Ball bearings)
5. Return idlers = 10' - 0" CTRS.
6. Belt width = 12" PVC 120
7. Conveyor width = 15" BR
8. Conveyor length = 100'= 0"
9. Drive 8" pulley = Center drive and take-up
Live load per foot = 45 x 20 = 14 lbs. Per foot
Live load = 100 ft. x 14 lbs. Per foot = 1400 lbs.
Bed rollers = 100 x 1.5 lbs = 150 lbs
Return idlers = 10 x 1.5 lbs. = 15 lbs.
Belting = 206 ft x .060 x 12 = 150 lbs.
Center drive and end pulleys = 77 lbs.
TOTAL WEIGHT TO MOVE 1792 lbs
Coef. of Friction 5% x .05
EFFECTIVE BELT PULL 90 lbs.
HP = 90 lbs. X 65 FPM = .20
33,000 x .85 x .95
Summary: Use the minimum horsepower offered by Hytrol: 1/3 hp (1/3
more than required).
LIVE ROLLER - HORSEPOWER CALCULATIONS
The same method for belt conveyors can be used for belt driven
live roller conveyors. If the live roller is to accumulate a
blocked load, simply calculate as though it were a moving load
then double the horsepower.
Horsepower for single strand chain driven live roller as well as
roller-to-roller chain driven live roller is calculated as
A. Determine the live load in the same manner as for belt
B. Add the weight of the rollers (See chart under belt conveyor).
C. Add the weight of sprockets and roller chain.
||WEIGHT OF SPROCKETS
||2 ½” Dia. #50 CH
||2 ½” Dia. #60 CH
||3 ½” Dia. #80 CH
|Roller to roller
D. Determine chain pull in the same manner as for belt pull under
||Allowable Chain Pull
||Conveyor Speed F.P.M
||65 to 80
||80 to 100
||100 to 150
Operation up to 24 hours
Continuous single strand: 1.0
Roller to roller: 1.2
Sudden stopping or reversing: 1.4
Dirty conditions: 1.4
COEFFICIENT OF FRICTION
Single strand 6%
Roller to roller 5%
The formula to use is:
HP = Effective chain pull x speed in FPM
33,000 x .85 x .95
Multiply the effective chain pull service factor to determine if
it is higher or lower than the allowable chain pull.
Horsepower calculations for chain conveyors are more complex in
that shaft torque and bending moments farther the picture.
Suggest checking with your Master Hytrol Distributor on
applications which require chain conveyor.
Below is a formula for determining sprocket ratio, motor RPM, or
No. of teeth (motor spkt.) x Pulley Dia. (inches) x TT x Reducer
shaft RPM = Belt speed (ft. per min)
No. of teeth (pulley spkt.) 12
Substitute known values and solve for unknown.
Wanted number of teeth on motor sprocket:
1. Drive pulley dia. = 8 inches.
2. Reducer output shaft = 48 RPM
3. Belt speed = 65 FPM
4. Number of teeth (pulley sprocket) = 32
Then: 65 x 32 x 12 = 21 teeth
8 P x 48
MORE MISCELLANEOUS USEFUL FORMULAS
RPM (pulley) = FPM (belt) x 12
Pulley dia. (in inches) x P
RPM (roller) = FPM belt x 12
Roller dia. (in inches) x P
RPM (pulley) = Motor sprocket (no. of teeth)
RPM (motor) Pulley sprocket (no. of teeth)
FPM = RPM (motor) x no. teeth (motor spkt.) x pulley (or roller)
dia. x P
No. of teeth (pulley sprocket x 12)
HP = Torque (lb. -ft.) x RPM = Torque (lb - inch) x RPM
Torque = Effective belt pull x ½ dia. of drive pulley.
ESSENTIAL INFORMATION REQUIRED FOR MOST PROBLEM SOLVING
1. Type of Products to be conveyed:
A. Carton (corrugated) (glued, stapled or taped bottom).
B. Bag (multiwall paper, cotton or plastic).
C. Bundle or bale (tight, steel or plastic bonds).
D. Wood case (cleats on bottom).
E. Plastic tray (smooth or grip bottom).
2. Size of Products:
3. How is product to be conveyed?
4. How will product be placed on conveyor?
B. Transferred from anther conveyor.
5. Method of Transport?
C. Combination of gravity and power.
6. How many hours per day will conveyor be used?
A. 8 hours (one shift).
B. 16 hours (two shifts).
C. 24 hours (three shifts).
7. Available electrical current?
A. Volt Phase Hertz
8. Maximum (not average) production rate?
9. Will conveyors be floor supported or hang from overhead?
10. Will conveyors be subjected to unusual conditions?
A. Wash down.
B. Extreme heat.
C. Extreme cold.
11. Will the customer require engineering services?
A BRIEF HISTORY OF THE CONVEYOR INDUSTRY
The conveyor industry actually started about 80 years ago
 in the Minneapolis-St. Paul area by a group of men
unloading wood shingles from rail cars. The idea worked so well
that part of the group decided to relocate to a steel tube mill
location and selected Ellwood City Pennsylvania, the home of
National Tube. This relocated group called itself Mathews Gravity
Conveyer Company with Rufus P. Mathews as president.
The group that remained in the Minneapolis-St. Paul area also
started a conveyor company named Standard Conveyor Company.
A Mr. Offutt was superintendent of National Tube in Ellwood City,
Pennsylvania. At times, Mathews got into financial difficulty, and
Mr. Offutt bailed them out and received stock in the company. He
also secured employment for his son John in the Mathews
engineering department. Also, Mr. Offutt's daughter was married to
the Ellwood city bank president. Upon Mr. Offutt's death, John,
his son, inherited all of the Mathews stock his father owned.
After Rufus P. Mathews, F.E. Moore became president. Then came
Bill Dean, then Odd McLeary.
F.E. Moore set up Mailer-Searles in San Francisco as the west
coast manufacturer of Mathews Conveyors and built a new plant in
Port Hope, Ontario, Canada. Mailer-Searles sold the area west of
the Mississippi River and maintained offices in Salt Lake City,
Los Angeles, San Francisco, Portland Oregon, and Seattle.
Mathews Chief Engineer, Norton Meyer, and Chief Draftsman, John
Offutt took Harry Harlick under their wings and taught him all
about the application of conveyors to industry.
In addition to Mathews, Mailer-Searles also acquired the
Standard-Knapp line of packaging machines.
Bill Dean was jealous of Bill Jaenicke, president of Mailer-Searles
because Jaenicke was offered the presidency of Mathews before Bill
Dean, but, Jaenicke refused, saying he had been born and raised in
San Francisco and did not care to relocate to Ellwood City.
Bill Dean decided to build a Mathews Plant in San Carlos and take
the Mathews line back. He also appointed P.W. (Joie) Brown as
President of Mathews-West Coast. The new plant had only 2 acres
and quickly outgrew the San Carlos facility. They purchased 80
acres in Chico and built a new plant. P.W. Brown ultimately died
of a heart attack and Bill Peppard was appointed Vice-President
and General Manager.
When Mathews took the line from Mailer-Searles, Bill Jaenicke
obtained the Alvey Conveyer line from Jack Alvey of St. Louis.
The Alvey Conveyor Company had started in the north barn of
Anhuser-Busch in St. Louis, furnishing all the conveyor for the
brewery. When Alvey solicited more work from other St. Louis
breweries, he was politely told to move.
Alvey eventually passed away and Jack Alvey and Bob Mayer bought
the company from his uncle's widow. Both Jack and Bob were
standard Conveyor sales people in New York and specialized in
Meanwhile, Hartford-Empire, manufacturers of automatic blowmold
glass making equipment bought Standard-Knapp. It was suggested
that Mailer-Searles also sell to Hartford-Empire, later known as
Bill Jaenicke later was told that Emhart was going to dissolve
Mailer-Searles. Emhart formed a separate Standard-Knapp office in
San Mateo and Harry Harlick was retained to finish up all
outstanding Alvey business, after which he went to work for FMC
corporation in Riverside, CA.
Now, Odd McLeary was President of Mathews and arranged a sale of
Mathews to Rex-Chainbelt of Milwaukee Wisconsin. Rex also bought
Nordberg a rock crushing equipment manufacturer and changed their
name to Rexnord. The cost of Mathews to Rex was $9M with $25k per
year retirement to Odd for a period of 5 years. Mathews had $9M in
the bank, so the actual cost to Rex as zero.
FMC set aside $10M for the Riverside Division to get into the
conveyor business. Since they were furnishing practically all
conveyor to the citrus industry, they had a good start. The
Riverside Division could purchase a conveyor company or start one
from scratch. The Riverside Division also manufactured about 7
different product lines; the bulk feed trucks which deliver cattle
and chicken feed, egg machines which automatically grade and
package eggs for producers, along with juicers and other equipment
for citrus growers.
Also FMC purchased some Palletizer patents from an inventor in Los
Angeles. The rest of the patents were purchased by Lamson
Corporation, of Syracuse, New York. This caused a legal battle
between FMC and Lamson which nearly bankrupted Lamson. Both
companies manufactured Palletizers.
FMC head office in San Jose discovered the Riverside Division was
diverting conveyor funds to other product lines and fired all
product managers and demoted the division manager Mr. Sid Boucher,
the conveyor sales manager Don Derricott was allowed to retire.
About the time Tom Loberg (Hytrol) designed the bale conveyor,
Bill Jaenicke also designed a variable speed bale conveyor to
elevate bales of hay to truck beds. E.W. Buschman (Buschman) was a
Rapistan salesman in Cincinnati when he decided to go into
business for himself.
There was a wheel conveyor manufacturer in, I believe, Buffalo,
New York, who hired local housewives to assemble wheel conveyors
at hours they chose and paid minimum wages. Their profits were
rock-bottom. Mathews also used women to assemble wheel conveyors.
They did a very good job in Chico.