THESIS
CONTINUOUS CONVEYORS
eB
HANDLING MATERIALS

FOR DEGREE OF M. E.

OPO
i
 

‘NItSCHEKE BROs.
| 31-87 East Gay St.
COLUMBUS, O,

 

 

‘JHESIS
CONTINUOUS CONVEYORS
~FOR-
HANDLING MATERIALS.
---000--=
NINETEEN HUNDRED TWELVE.
CLEM C- FORD.

-o00=
THESIS
vontinuous Conveyors for Handling Naterials,

The manufecture of conveying machinery in this coun-
try and its development to meet the demands of possible ap-
plications begen about 1850. The first steps taken in re-
sponse to requests for such machinery was by manufacturers
of the detachable link belt and was due to reyuests for a
chain with attachments to which pans, flights, etc., could
be fastened,

Tnere is very little published information r>garding
elevating and conveying mechinery aside from the meager ac-
counts of its use and adeptability, in specific instances,
given in the trade journals as advertising matter by the
vérious manufecturers. and as far as the writer has been
able to learn, there ere no text books devoted to this sub-
ject, nor any schools in which definite instruction regard~
ing it is given, although it is playing a very importent
role in tie present tendency toward "conservation of energy",
"labor seving applienves", etc,

Reelly reliable deta as to economies effected Ly the

36314
Sh, #2.
Continuous Conveyors for Handling “aterials.

use of continuous conveyors is lacking even emong their man-
ufacturers, however, there is no doutt that the managers of
many concerns have been eble to show their directors where
Savings have been made by their use. But they are careful
not to make such information public for competitors to prof-
it by their ideas and the expense of testing them out.
uspecially have the large manufacturing plants, to-
gether with lerge producers of raw or finished products,
found the use of continuous conveyors to te most profiteble,
Further, it would be practically imrossible to manufacture
many products on a commercial scale were it not possible to
handle same during the process of manufacture with continu-
ous conveyors. There is practically no material used in quan-
tities sufficient to insure the installation of conveying
machinery to which it is not adaptable. Even small factories
or institutions which handle a given article in guantities find

various uses for conveyors,

A short history or auescription of the cheins used in
tne development of elevating and conveying machinery will be
of interest in leading un to the various styles of conveyors
in use as well as their adaptation to specific machines,

The detachable chain (Fig. 1) was the first to be in-
vented and developed. As steted above this was about 1880.

This chain is still very popular for light, simple elevators
 

 

 

 

 

 
“h. #3.

Continuous Conveyors for Handling Materials.

and conveyors.

Two or three years later a chain with solid ends and

steel pins was developed (Fig. 2).

About the same time a roller chain was patented. Of
this type there are now three styles in use, the malleable
roller chain, the steel thimble roller chain, and the steel
roller chain (Pigs. 3 and 4).

The Malleable Roller Chain has malleable iron side
bars made in two pieces, with a projection at one end, on
which the roller fits. The bars are held together with a
steel rivet pin.

The Steel Thimble Roller Chain is made of steel side
bars. It has casehardened bushings or thimbles over the pins
on which the rollers fit. The thimble is pressed into the
two inside bars and locked so it can not turn. The pins are
locked in the two outer bars, The articulation takes place
between the pin and thimble where there is a large wearing
surface, thus making a very durable chain,

*

The Steel Roller Chain is of the same general con-
struction as the steel thimble roller chain, except it is
not provided with thimbles and the pin is not locked in the
side bars, The articulation is between the links and the
pins on a comparatively small surface. The pin being free

to turn allowsit to take the wear around its entire circum
Sh. #4.

Continuous Conveyors for handling waterials.

ference,

The rollers on these chains reduce the wear on the
sprockets very. materially. They also reduce the friction
on the conveyor runways, especially in conveyors which carry
their load, thus prolonging the life of an eyuipment as well

as reducing the amount of power necessary for driving the

conveyor.

The short piteh steel thimble roller chains are used

for transmitting power.

The drag or sawdust chain (Fig. 5) is allowed to run
in the bottom of a trough thus acting as a conveyor by it-
self. The chain is covered with the material handled, mov~
ing it along bodily, often of a depth up to a point where
the friction on the sides of the trough is 80 great that the
Chain drags thru the material instead of moving it along.
These chains are made of malleable iron or forged steel bars.
They are also made with projections from the side bars to in-
crease the width of the chain, thus giving them greater car-

rying capacity. These chains are used for handling sawdust,

sand, ashes, etc.

The transfer chain (Fig. 6) is used in two or more
strands side by side for handling lumber, boxes, etc. The

Ghains slide on runways and are spaced the proper distance

apart so that the articles handled can extend across them,
Sh. #5.

Continuous Conveyors for Handling tiaterials.

For conveyors of long span the coil chain (Fig. 7) .
is often used. It is forged from round stock and drawn to
pitch so that the links will fit the teeth in the driving
sprockets. Malleable iron blocks are inserted at the artie-
ulation points to give a large wearing surface for the links,
also to take the wear from the sprocket teeth. ‘hen attach-
ments are reyuired they arecast integrel with these blocks,
This Chain is adaptable to conveyors which make either hori-

zontal or vertical turns or both.

The flat and round link chain (Pig. 8) is adapt-
able to conveyors for which the flights, buckets, spurs,
ete., are bolted directly to the links. An ordinary black~

smith can forge links for repairs in case of emergency.

The steel or bronze bushed chain (Fig. 9) is used
where gritty material is to be handled. The articulation
takes place between the pin and the bushing. These parts

can be quickly replaced at little expense when necessary.

The combination steel and malleahle chain (Fig. 10)
is a great favorite for elevators and conveyors of medium
Size. It is easily assembled and dismantled. The pins are
locked in the steel links, thus giving a large surface be-
tween the head of the malleable link and pin, for wear due
to articulation. jfith this chain it is elso possible to use
traction wheels at heads of elevators. These cause less wear

than sprockets. Attachments are cast integral with the mal-~-
leeble links,
 
Sh. 35,

Continuous Conveyors for Handling llaterials,

The steel link chain (Fig. 11) is of simple con-
struction and inexpensive. It is often used for light
scraper conveyors by forging a bar so it will extend across
between the strends of chain and also form the inner bars
of the two chains. Steel screpers are then bolted to these
cross bars. Hard iron werring blocks are spaced at inter-~
vals on the chain to take the wear due to the friction on

the runways.

The Patnoe chain (Fig. 12) is used for heavy con-
tinuous bucket elevators for handling stone, gravel, etc.
Tne buckets are bolted, with their backs flat against the

Ghain without the use of attachments.

The forged steel chain (Fig. 13) is made with the
inner links of drop forgings end the outer links of steel
bars. The pin is of lerge digmeter with a flet extension
milled on each end for locking it in the outer bars. The
head of the inner link furnishes e large wearing surface
for the pin to tcke wear due to articulation. Yhe pins and
forged links are cteehardened, This chein is especially

adapted to heavy work.
oh. 7.

Continuous Conveyors for Handling Materials.

vonveyors.

Continuous conveyors may be divided into two clésses:~
namely,

1. Those which push or pull toe load, and

2. “hose which actually cerry the load.

T.e style of conveyor to be used in a given case is
usually determined by the physicel properties of the mater-
jal to le handled. The amount of material to be conveyed,
to. ether with the locel conditions under which it is fo be
hendled :aust also te given consideration. Such considera~
tion will suggest the many different possible arrangements
of conveyors to suit the verious conditions under which they
must be operated.

Conveyors which Push their Loads-Claess 41,

Cf the conveyors which push or pull their load, the
spirel conveyor (Pigs.14 and15) is no doubt the most widely
used. It is mede up of spiral steel plates mounted on @
hollow sheft of 106'-0" to 12'-O" in length. The sections
of conveyor are coupled together with pieces of shafting
which extend into the hollow shafts and are bolted in place=
vith a space between the ends of the conveyor for a bearing
on the coupling snaft. The bearings are carried by hangers
from the top of the conveyor trough. These conveyors are
very compact and are especially suitable where available
Space is very limited. Tney are not usuelly used for lengths

over 100'-C" or 125'-0", uue to the tortional strein on the
oh. TS

Continuous Conveyors for Handling Materials.

hollow shafts.

for certein meterigl.» some engineers prefer to nave
the conveyors lie on the Lottom of the trough and do away
with the hangers. the writer has recently constructed a con-
veyor of this tyre 16" in diameter on 4" extra heavy pipe
175'-O" long for handling soue powder. This particuler con-
veyor reyuired 5 H. F. to operate empty, as measured in cur-=
rent consumed by a motor. This, however, was with a very
thin coat of heavy greese on the trough bottom.

Spiral conveyors are usually allowed to carry mater~
jel of e depth eyual to 1/3 the diameter of the spiral and
are driven at 60 to 80 r.p.m. For light unabrasive material
however, sucn as grain, seeds, etec., the; are often speeded
up to 1CC or 125 r.p.m. tne friction of tne material in
the trough ena on the conveyor or flights cauces ravid wear
and consumes a great deel of power, hence it is preferahle
to overate at the lower speeds. These conveyors are made by
manufecturers in all sizes from 4" to 18" diameter with the
pitch of the flights equal to the diameter of the conveyor.

For handling sand, eshes or other gritty materials,
the flights are often made of cest iron and mounted on a
Solid shaft. The cest iron flights will wear better than the
Steel flights. However, the iron flights are so heavy for
the size shaft it is possible to use, that these conveyors

do not alweys give perfect satisfaction. Conseyuently, a

heavy steel flight is usually more preferable than the cast
 

ev

FIG 26

 

 

    

aaa ji 2
ESTES
Sh. 710.

Continuous VConveyors for Handlittg “iaterials.

bolted together about the cable at regular intervals to
match the spacing of the geps in the sheaves used for driv-
ing the conveyor. The ceble is driven by the end of the
flight engaging against the face of the gaps in the sheave .
and not due to friction between the rope and sheave as in
the case of a transmission rope drive (Fig. 18a}. Sheaves
are made with adjustable rims so that as the cable wears

and stretches, the pitch diameter of the sheaves may be in-~
creased to keep the distance face to face of geps equal to
the distance face to face of clamps and flights. Flexible
teeth are also provided to reduce the wear on the clamps and
to prevent the ceble running with a jerky motion. In good
practice the pitch diameter of the sheaves should not be less
then sixty diameters of the rope. The two strands of con-
veyor may be made to operate one above the other or side by
Side in @ horizontal plane as the available space and local
conditions may require. The cable is suitable for conveyors
which turn in either vertical or horizontal planes. It is
adaptable to retarding conveyors for bringing coal, etc. down
mountain sides and is also used on long car hauls and con-
veyors farhandling lumber, pulpwood, etc. The cables used
for this purpose are so woven as not to twist or rotate when
used in a conveyor. Those used in best practice are woven
about a steel center, although ropes with a hemp center are
often used. “ith ropes on hemp centers it is difficult to
hola the flights and clamps in plece due to the fact that

the rope will crush out of shape, thus making it difficult
Sh. #11.

Continuous Conveyors for Handling Materials.

to maintain the proper bearing surface between the clamp end
the rope. The weak point in a cable conveyor is usually due
tc the fact that the cables have a tendency to crack and
break at the ends of the clamps due to the continuous bend=
ing about this point as the cable turns about the head and

foot wheels,

Log conveyors (Fig. 19) are made up of a strand of
Chain with steel spurs running in timber guides. The spurs
are arranged at intervals with a spacing somewhat greater
than the length of the logs to te handled. The logs are
rolled into the guides on top of the chain and ere thus pulled
eélong lengthwise by the spurs.

Refuse conveyors (Fig. 20) used for handling the ref-
use from saw mills or woodworking machinery, are of the same
generel construction as the log haul except that the wood
flights are used instead of steel spurs and ere spaced much

Gloser together, usuelly 2'-0" to 4'-0O" centers,

Trolley conveyors are made up of a single strand of
rope or chain which is carried by roller attachments on one
runway and provided with a finger or projecting attachment
extending over an adjacent runway on which is @ trolley with
a sling or hook for carrying the material to be handled, As
the conveyor moves along, the projecting finger engages the
trolley end pushes it along on its runway. These conveyors

are used extensively in packing houses for handling carcasses
Sh. 712.

Continuous Conveyors for Handling Materials.

of dressed meats. They are also used for handling large

cans of milk, packages, bundles, etc.
Conveyors Which Carry Their Load-Class #42,

Of this class the belt conveyor is probably the old-
est and most commonly used. Fig. 21 will give an idea of
how the conveyor is arranged and how troughing idlers are
made. The conveyor consists simply of/heavy belt driven over
pulleys on head and foot shaft and supported between pulleys
by troughing idlers. “Then handling light material the belt
is often carried in a flat bottom trough. Conveyors are made
with belts from 16" to 48" in width and up to 1000'~0" in
length, that is, center of head shaft to center of foot shaft.
_ Experience has shown that it is a very difficult matter to
train a belt less than 16" in width so that it will run
straight and smooth, consequently, manufacturers do not gen=<
erally recommend using a belt less than 16" wide. The belts
used are either of heavy canvas closely stitched or of can=-
vas ducking with a rubber binder and rubber cover to protect
the canvas from wear and moisture. The rubber covering var=
ies from 1/16" to 1/4" in thickness. For handling hot mat-
erial there is a closely stitched canvas belt on the market
which is guaranteed to handle material up to a temperature
of 350 degrees Fahrenheit. For handling materials which
tend to stick to the belt, a small revolving brush is placed

just under the discharge pulley and driven from its shaft
Sh. 135.
Continuous Conveyors for Handling Materials.

so as to rotate in the opposite direction of the travel of
the belt. The brush shaft is carried in adjustable bear-
ings so as to make it possible to shift the brush in order
to keep it in contact with the belt.

The limiting angle for inclined conveyors is about
20 degrees, however, conveyors handling wet sand have been
installed with an incline of 3% degrees.

For handling small packages, paper boxes, etc., a
flat belt is used with supporting idlers of 2" and 3" dia.
rollers mounted with ball bearings and spaced from one to
three feet apart.

For handling bulky material such as coal, ore, etc.,
troughing idlers are used. These are made with inclined
pulleys to hold the edges of the belt above the center and
causing it to assume a troughed shape. This gives it a great-
er carrying capacity than in the case of a flat belt and also
prevents material spilling off along the conveyor. The first
troughing idlers used were made in one solid piece either of
wood or iron and of greater diameter at the ends than at the
middle of the rollers. Thus the peripheral travel of the ends
of the rollers was greater than that of the middle portion

and consequently wore the belts very rapidly. This style was
later replaced with an idler made with horizontal pulleys in
the middle and inclined pulleys at either end of the horizon-

tal pulleys mounted on independent shafts so that each could
Sh. 714.

Continuous Conveyors for Handling Materials.

revolve independently of the other. The most up-to-date id-
lers are of this type with ball bearings for the pulleys.
Troughing idlers should be spaced as follows, depending up-
on the weight of materiel to be handled:- for 16" belts~

Ae ft. to 5 ft. apart and 18" to 22" belts and over~ 3 ft.
to % ft. apart. The return belt is carried on straight
face idlers spaced 10 ft. to 12 ft. apart.

The lubrication of idlers is a very important item
especially when a rubber belt is used, as oil or gresse
causes the rubber to deteriorate very rapidly. Oil should
not be used as it will run down over the bearings, shaft, etc.,
cause dirt and dust to collect, and produce excessive wear,
It is also apt to run out over the pulleys when they are
Standing still, coat the pulley face and thus finally cover
the belt. Grease is much more preferable and when applied
near the middle of the bearing or pulley hub thru a hollow
Shaft it will work out towards the ends of the bearings and
carry out any dirt or dust which may get into them. It will
also collect in a ring on the shaft at the end of the bear-
ing and form a very efficient dust collar.

Endless belts are often used, however, steel lacings
have been found to give good satisfaction for connecting the
ends of the belts and are more commonly used.

For long wide belt conveyors it is often found nec
essary to use a snubbing pulley to get a large are of con-

tact on the driving pulley. It may also be found necessary
Sh. 415.

Continuous Conveyors for Handling Materials,

to use rubber covered pulleys to increase the friction of belt
on pulley to secure the necessary tractive power. Pulleys
Should alweys be crown feced and two inches wider than the belt.
Diameter of driving pulley should be not less than five inches
per ply of belt used. Diameter of teil pulley, four inches

per ply of belt used. For very long conveyors it may be found
necessary to insert intermediate driving pulleys. <A belt trav~
el of 200 ft. per minute is considered good practices; however,
speeds up to 5CC ft. travel per minute are often used. A good
yuality belt properly installed for rough work, such as hand-~
ling coel in a coaling station, should give about three year's
satisfactory service.

The simplest form of belt conveyor dischérges its load
over the head pulley. Zowever, when handling material in bulk,
it is possible to uischnerge at any point &long the conveyor
by use of a tripper. It is also possible to arrenge a series
of fixed discharge points by arranging pulleys Similar to those
in e tripzer.

Trippers are maue to te eitner hand propelled or power
driven. Phe power is obtainedfromthne belt itself in such a
way as to csuse the tripper toc operate automatically back and
forth over the entire length of the conveyor or over any por=
tion of it.

The formula on the attached blue prints will give the

approximate amount of horse power necessary to drive a belt

conveyor under ordinary conaitions when properly installed.
They clso show the cepacities of different width belts in dif-
ferent styles of trougning idlers in tons per hour.
 
 
 
 

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Sh. #16,

Continuous Conveyors for Hendling “ater: els,

Curved Flight Conveyors (Pig. 22).

Vouble beaded flight conveyors are used for picking
tables in coal tipples, feeders. etc., where a continuous
apron conveyor is reyuired for materials in bulk. They are
made up on roller cheins snd vary from 12" to 6'-o" or 7'-o"
in width. Steel ends are provided to extend up at right
angles with the flignts, thus meking the completed conveyor
in the shape of e« rectangular trough. These ends are made
ur to 12" in height. “hen used as feeders, stationary skirt
boards 18" to 24" in height are arranged inside the ends,
thus making it possible to handle material of this depth
full width of the conveyor. The conveyor is then run very
Slowly to obtain tre desired cepacity. ‘hen used a3 feed~
ers they are driven at 20' to 20' per minute. ‘when used as
ordinary conveyors they are driven at 50' to 100' per minute.
The shape of the flights gives them stiffness for ordinary
spans, but for the wider conveyors they aré reinforced with
an angle iron pleced on the under side and running the full
length of the flight. ‘When the conveyor is on an incline
such thet the material has a tendency to slide back down
same, angles are riveted on top of the flights with an up-=
standing leg. These act as lifting blades and hola the
material from rolling back.

When handling material the breakage of which is an
importent item, such as lu:p bitumionous coal, the single

beaded flight (Fig. 23) is used because of the fact that
Sh. #17.

Continuous Conveyors for Handling Meterials.

the delivery spout cen be raised higher than with the double
beaded flights and the coal does not drop as great a dis-
tance when discharging from the conveyor; consequently, there
is not as much breskage at this point as with the double
beaded flights,

Figure 23a shows relative height of discharge chute for single
beaded and double beaded flights.

Pivoted Bucket Conveyors (Fig. 24).

The pivoted bucket type’‘of conveyor is used in boil~
er houses, cement milis, coal storage plants, etc., where a
conveyor is required to elevate, convey to storage, and re=
Claim to storage or where a runaround conveyor can be ar-~
ranged, to do the work of two conveyors. For instance, in
@ boiler house the pivoted bucket will elevate coal from a
railway track hopper to an overhead bunker from which the
coal is delivered directly to furnace hopper, through valves
and chutes, as required. The same conveyor will also reclaim
the ashes from a pit under the boiler room floor and deliver
them to a storage tank outside of the building from which
they can be delivered to cars or wagons through valves and
chutes.

Thereare two styles of pivoted buckets. They are.
known as the "contact lip bucket" and the “overlapping lip
bucket". In the former the edge of the buckets barely butt
together when assembled in the chain and loaders are re=

quired for delivering material to them. The loeders are
Sh. #18,

Continuous Conveyors for Handling Materials.

placed directly over the conveyor on & horizontal run and
attached to the bottom side of a bin. They are so construoct=
ed that as each bucket comes centrally under them & given
anount of material is dropred directly into the bucket. The
loaders are operated automatically by the conveyor through

a set of levers which project down so as to engage the chain
rollers. This type can be reversed and operated in either
direction.

The overlapping pivoted buckets are made with a pro-
jecting lip so that one end of one bucket overhangs the end
of the next bucket vhen assembled in the chain. Instead of
the loaders, skirt boards are provided at the loading points.
These consist of steel plates arranged just above and at
each side of the conveyor, on a bevel, with the lower edge
overhanging the bucxets. These form a hoppered trough full
length of the loading portion of the conveyor. The material
is delivered to the conveyor in a steady flow thru chutes
arranged at the loading points. Naterial can also be shovel-.
ed or scraped directly into the conveyor at any point along
the loading section. This type of bucket can be operated
in only one direction. Lap changing devices are also nec=-
essary to keep the buckets lapped in such a way that they
will turn the corner wheels when loaded without tipping and
spilling their loads.

Bither the "contact lip" or "overlapping lip” bucket

Can be discharged at any point desired along the horizontal

run. This is accomplished by a tripping cam which engages
(*%
sh. 719.

Continuous Conveyors for Fandling Naterials.

rollers or projections at the ends of the buckets anid tilts
them sufficiently to allow the material to run out. The
tripper is carried by rollers on a runway, extending the
full length of the bin or hopper into which the material is
to be delivered, and is operated by an endless rope over a
drum located at one end of the conveyor either automatical~
ly or by hand so thet an even distribution of material may
be had in the bins,

These conveyors operate at a speed of about 50 ft.
per minute. The buckets are made of malleable iron and

mounted in either 18" or 24" pitch steel thimble roller

chains.

Drop Pan Conveyors.

The drop pan conveyor (Fig. 25) is used for deliver~
ing rock, cement clinker, etc., to furnaces where @ prac-
tically continuous feed is desired to more than one furnace
at a time. These are made up of steel pans in sets, the
number of pans in a set corresponding to the number of fur-
naces to be fed. The front ends of the pans are carried by
axles extending from chain to chain, with a roller at each
end of the axle, the axle being arranged to pivot in the
Chain, The rear end of the pan is also carried by an exile
and rollers. The axle, however, does not connect in the
chains and the rollers ate at a different gage than the
front rollers, each pan in a set has rear rollers of a dif-
ferent gage then the other pans. There is also a separate

runway for each set of rear rollers. The discharge is ef-
Sh. #20.

Continuous Conveyors for Handling laterials.

fected by a curved drop in the runway for rear rollers at
the discharge point for that particular pan. As the pan
passes this point the rear end drops down and the material
slides out. Fan % of a set will discharge at the first
furnace; pan #2 will disoharge at the second furnace; pan
#3 will discharge at the third furnace; and so on, thus
making a constant intermittent feed at such short inter-

vals of time as to be practically continuous at each fur-

nace,

Cast Iron Pan Conveyors.

Cast iron pan conveyors (Fig. 26) are made very
Shallow, not over 3" to 4" in depth, for handling hot
ashes and clinkers. ‘hen the material handled has a tem=
perature equal to a red heat the pans are made in halves
and bolted together to prevent their breaking due to ex-

pansion and contraction. These conveyors can only dis=

Charge over the end,

Wood Apron Conveyors.
Yood apron conveyors (Fig. 27) are used for hand-
ling boxes, barrels, bundles, etc. They are made up of
&@ double strand of chain with wood flights bolted to them
So as to form practically a continuous apron.
For short conveyors, or for handling light material,

Such as in cooling tanks in canning factories, a flat and

round link chsin is often ttsed. “ith this chain the ends
Continuous Conveyors for Handling Waterials.

of the boards are notched out and fitted into the flat links,
This makes a very simple and inexpensive construction,

Amore durable construction, however, consists of a
roller chain with attachments on one side only so as to hold
the chain outside of the flights. This leaves the chain in
the clear to be carried by its rollers on runways for both
carrying and return strand. This construction with heavy
Chains and flights is used for freight ramps, heavy packa~-

ges, etc.

Steel Pan Conveyors.

Steel pan conveyors (Pig. 28) are used for handling
crushed rock, gravel, ores, etc. The pans are made of steel,
often wood lined, and suspended between two strands of chains
by being bolted rigidly to the chain bars. The lips of the
pans are curved and overlap each other, The best construc-
tion for this type of conveyor is with thru rods in place of
the regular chain pins and with each end of the rod drilled
and fitted with greese cups so as to force the grease out
into the roller at cbdout the middle of the hub. Waterial

can be discharged only as the pans turn the head wheel to

take the return strand,
Continuous Conveyors for Handling Materials,

ilevators.

( See Fig. 29-the following lettering arranged for
elevators reading left to right).
4- Single strand Chain Centrifugal Discharge.
B- Double " " " "
C- Belt Elevator | " "
b- Deflecting ‘heel - Perfect Discharge.
i= Fnuckle heel " "

F- Continuous Type Bucket " " and Centrifugal Discharge.

Continuous elevators may be equipped with different
styles of buckets. The most common and widely used is what
is known as the "Stendard Steel Bucket". MThnese are pressed
and folded into shape from steel plates, of various thick-
ness for each size of bucket to suit the weight and nature
of material to be handled,

“or handling materials which wear on the equipment
rapidly, malleable iron buckets are used. They are made in
practically the same sizes anu shapes as the steel buckets,
For handling sticky material, such a suger, damp clay,
Pine wet ore, etc., the malleable iron "shelf bucket" is
used. This is made with tne back and bottom at right angles
With each other, so as not to allow any"pockets" for the

material to cling to.

Centrifugal Discharge Hlevators.

ventrifugel elevators ere usually made up with a
She 723,

Continuous Conveyors for Handling Vaterials,.

chein or belt attached on the back of either "stanaerd steel"
or malleable iron buckets and are uriven at such speed that
as tne buckets turn over the head wheels the material is
thrown out into a discharge chute. The following table gives
the chain tr: vel and r. p.m. of head shaft for various aian-
eters cf head wheels, as determined by ctreful tests, to give
& clear aischarge from tne bucxets. These speeds may be

a
84

varied by or af éy4 Still] oblteéein fair results,

Dia. of heed wheel 15 Mee GM 21M 24 Me D7 Mae BOM FAN BSN OMA Ge
Rev. per min. 42 -40 =-%= 37 = 25 =35 =-34 -74 -33 -32

Sreed in ft. per cine 195-150= 209 252+ 254-27 d= 274 = 520= 74 5=dC2

Deflecting “heel levator.

This tyre of elevéetor is made up of two strands of
chain, one attached at each end of either steel or malleable
iron buckets. The deflecting wheels are placed just below
and under tre head wheels, and deflect the chain back on the
down strand so that as the buckets turn the heed they will
overharg the end of a delivery shute. In good practice those
‘elevators are constructed with head wheels 24" to 35" dia.,
and with the buckets treéeveling at a speed of about 175 ft.

per minute.

Knuckle ‘wheel slevator,
knuckle wheel elevators are made up with chains and
buckets assembled the same as for deflecting wheel elevators.

They are driven at slow speed, 50' to 100" travel rer min-
ch. fed.

Continuous Conveyors for Handling Materials.

ute, and the buckets discharge their loads into 4& chute lo-
cated between the two upper wheels. These uprer wheels are
raised one higher than the other, so that as the buckets
pass the discharge chute they are traveling down an incline,
thus bringing the buckets as near bottom side up as possible
at the delivery coint. This type of elevator is serviceable
in handling very wet sand, gréevel, and other substances
which have a tendency to cling to the buckets, ‘wnen héend=
ling sticky material a water pipe is often arranged just
above the chute and extending across under the buckets, SO
as to throw a spray into the bucket while over the chute,

to wash the material out end keep the buckets clean, The
Spray also keeps the chain clean and reduces the wear caused

by sand and grit at the points of oecillstion.

Continuous Type Bucket Elevator.

The continuous type bucket is made to have a chain
or belt attached on its back with only a small clearance
between tre bottom of one bucket and the top of the next
bucket. ‘ith these buckets material can be fed to the ele~
vator along the up-going strand with very little spilling.
When run at slow speed, as the buckets turn the head wheel,
the material is discharged upon the back of the next pre=
ceding bucket, and to prevent tre material from spilling
over the ends of the buckets and falling back down the ele-

vator, their ends are made to extend about 2" below the
ha-
Sh. #25.

Continuous Conveyors for Handling Naterials,

bottom so that as they turn over the head the bottom of
each bucket forms a trough for the material of each succeed-
ing bucket to flow direotly into the discharge chute. “ith
the above style of bucket the elevator may be driven at a
speed of 100 ft. to 140 ft. per minute,

Continuous buckets without the flanged bottom are
also used, but in these cases the elevators must be driven
fast enough to obtain a centrifugel discharge, in order to

insure a clean delivery.

V Bucket Elevator and Conveyor (Pig. 3%).

This style of elevator is made up of two strands
of chains, one bolted on each end of a Y shaped bucket.
For light run-around systems this makes a very simple con~
struction. The buckets scrape the material along on the
horizontal runs, and with a curved trough at the corners,
they can scoop the material up end carry it on the vertical
strand, drop back into a trough on the upper horizontel run
and scrape along to the discharge points. They are used

mostly for handling small coal.

Barrel Elevators.

Barrel elevators (Pig. 31) are made up of curved
arms bréced by heel links and extending out at right angles
from two strands of chain. Both arms and heel links are
festened to chain attachments anu to eagh other by pin
connections to allow them to turn the head and foot wheels.

Barrels or packages are picked up from loading fingers which
sh. 426,

Continuous Conveyors for Handling Materials.

project out from the loading platform, and are discharged
over the head on to unloading fingers. For handling secks
of flour, grain, or any material which does not pack close~
ly so as to make a firm, solid package, it is necessary to
use arms of special shape and with a wide face to keep the
sack from sagging down between the arms and catching on the
sprocket teeth as they turn over the head, or wedging be-
“tween the trey fingers and loading fingers, as they are

picked up, in such a way as to break or tear the sack,

Tray Klevators,.

Tray elevators (Fig. 32 and Drege. 4543-C) are used
for handling packages from one floor of a building to any
other floor. The package is picked up on the up going
strand, carried over the head and delivered at any floor
desired while on the down strand. The trays are hung from
stud-pins between two strands of chain by arms of such length
that the center of gravity of the package is well below the
pivot point of the hangers. At the lower end of the hangers
is a cross bar to which the carrying arms are fastened. The
cross bar extends through the hengers and is fitted at the
ends with rollers which run in guides to prevent the tray
from swinging on the up and down strands.

The loading and unloading of trays is effected by
fingers which extend across the floor opening from either
Side and are so arranged that the trays and fingers can

pass between. The loading fingers are slightly inclined
 

ee ee

 

ogee eer

 

 

 

 
Sh. #27.
Continuous Conveyors for Handling Miaterials.

toward the center so as to have a tendency to load the trays

centrally. The unloading fingers are arranged with the

inner set raised above the floor and the outer set at about
the floor level all of them on & straight incline from the

inner shaft to the edge of the floor opening. This incline
with fingers for handling barrels and kegs is about 3C degrees
with the horizontal and 45 degrees for boxes, bundles, bales,

eve.
| large
When handling, packages it is necessary to use two

short head shafts instead of one thru shaft. iach of these
shafts is provided with a spur gear and is driven by pin-~-
ions from one countershaft. It is customary to use a worm
gear drive to this countershaft. The worm will act as a lock
to prevent the elevator from running away should power be
suddenly cut off while the elevator is loaded.

These elevators should run at 50' to 70' per minute,
The trays can be spaced from 8' to 10' apart, thus giving
a capacity of 6 to & packages per minute.

These elevators are especially serviceable in large
ware houses, wholesale houses, breweries, storehouses for
barrels, etc.

There is also a patented tray which will discharge
its load while on the up going strand. This is serviceable

where available space is very limited for installing an ele=

vator.

So much for the conveyor and its companion, the

elevator. Following are several descriptions of installations
of conveyors.
 
Sh. #28,

Continuous Conveyors for Handling liaterials.

Some Typical Installations.

A Coal-Hendling Conveyor.

Drg. 0-5608-09, Sh. fl-4 shows a system of belt conveyors
for handling coal from the mine entrance and delivering
either to washery or to storage bins. The entrance to this
mine is by means of a drift into a side hill. The washer
and power plant is located below the entrance on the hill side
and the coke ovens are scattered along the bottom of the valley
below the washery. As all of the coal mined at this plant
is made into coke, it is all pulverized and washed before
delivery to coke ovens so as to make the coke as low in sul-
phur as possible.

Previous to the installation of this system of con-
veyors, the coal was gethered in the mines in small cars
and brought to the opening by means of an electric locomo-
tive. A wooden trestle extended from the opening out from
the hill side to a point over the pulverizer in the weshery
building. The cars of coal were hauled out on this trestle,
a distance of about 175 ft., one at a time, with a mule,
- dumped and brought back to the entrance. The out put of
the entire plant wes limited by this method of getting the
coal from the entrance to the washery. It will be noted
from the drawing that the coal is now delivered to the con-
veyors from a& large concrete hopper by means of a double

beaded flight conveyor acting as a feeder. This hopper, for
 
Sh. #29. |

Continuous Conveyors for Handling Materials.

which it was necessary to blast out the rock, is located
just outside of the drift, the top being at a level with

the track into the mine. The entrance to the mine was made
a ¥ so that the car tracks could come out around a small
loop and back into the mane. The loop passes over this
hopper. The oars are now brought out of the mine in a

long train by the locomotive, and as they pass slowly over
the hopper they are dumped two at a time and are immediately
returned into the mine for reloading. ‘While these are being
loaded another trein is brought out by the locomotive, and
so on.

It will be noticed that the first conveyor is on an
incline and terminates in a steel frame head house. Here
the coal is delivered into a two way chute provided with a
fly valve. One chute leads out to the power house boiler
roomand the other, which is about 50 ft. long, leads on
down to a chute at right angles with the main chute and
delivers into the washery building to the crusher. If for
any reeson the washery is shut down, the coal is allowed to
pass on down the main chute, instead of going to the crush-
er, to @ second belt conveyor which delivers to an elevated
storage bin. The delivery end of the first conveyor is
elevated 80 as to get sufficient incline for the chute leade
ing to the boiler room. This chute is used only as coal is
needed for the boilers, and delivers the coal on to the

boiler room floor in fromt of the furnaces. The head house
Sh. #%C.

Continuous Conveyors for Handling Materials.

is utilized for transmission machinery for conveyors, and
steam engine for driving same. The chute to crusher is
provided with a flat bar soreen which removes the fine coal,
thus relieving the duties of the crusher considerably.

The fine coal taken out by the screen is carried on into

the washery by a flume.

The coal delivered to the storage bin is drawn out
into cars, which pass underneath the bins, and is delivered
to the coke ovens without being washed and made into a sec~
ond or cheaper grade of coke.

The entire structure and supporting frame is of
structural steel work covered with corrugated iron. A walk~
way is provided on each side and the full length of the con»
veyor runways. Small doors are placed opposite all idilers
to facilitate oiling and inspection. A 30", 5-ply Century
rubber conveying belt with 1/8" cover was used and was carried
by 3-pulley troughing idlers every 5'-0" on the carrying
Side and straight faced return idlers every 10'-0" on the
empty side. Head and foot pulleys were 36" diameter and
42" fece, and snubbing pulleys of the same size were used
near the driving pulleys. Both conveyors are driven from
one main jack shaft by chain and sprocket and provided with
Clutches so that they may be started one at a time and also
so that the lower conveyor may be thrown out when not in
use. The double beaded flight feeder is driven from the

foot shaft of the first conveyor.

vith the installation of modern machinery as sbove
 
 

 
Sh. 31.

Continuous Conveyors for Handling liateriels.

described, the output of this mine wes increased approxi-~
mately one hundred percent without an incre&se in cost of
handling, this to say nothing rerarding the greater ease
of handling.

iuilk Can Conveyor.

Drawing 0-392-11, Sh. %1, Drawing H-2455 and Photo-
graphs Nos. 4452 and 4354 show the arrangement of a conveyor
for transferring cans of milk from milking barn to dairy
building. The conveyor is made of wire rope cable with at~
tachments for pushing a trolley which carries the can of
milk. The attachments and transmission clamps are provided
with rollers which are carried by angle iron runways end
just above the trolley runway. The runways cre held in
proper positicn relative to each other by steel slings and
are supported from the cross arms of steel pire roles. The
poles are 5" diameter, spaced 15'-0O" apart and set in con-
crete piers.

A large locp is provided in the trolley track at
each end of tne conveyor on which the trolleys &Gre allowed
to accumulate or be held for loa&uing @nd unloading. The
cans are placed in the trolley slings on the loop at one
end of the conveyor, pushed out on to the runway and as
the pusher attachment s come around they engere the trolleys
and push then to the other end of the conveyor. Here the

trolleys run out on to the loop and stop.
ee
Sh. 732.

Continuous Conveyors for Handling Meterials.

Clean cans, milking pails, streiners, etc., are sent
to the barn on the conveyor & neeced,.

With this eyuiprernt the milk is delivered to the
dairy as fest es gethered, thus méexving it possible to pro-
duce "certified milk" on e commerciel scele and at the same
time facilitating the work in the deiry beceuse the mili is
brought in one can at a time as fest as collected instead
of vteing delivered all at once and not until the last rpail-
ful has been getherec.

Two of these conveyors were inst&lled at the Fartman
stock arm ne&ér Columbus, OShio. Cne conveyor is ebout 250'~0O"
and the other about 450'-0O" long. The total cost of the
installation of these two conveyors wes about 2>4500.00.
However, they meen & saving of the time ana expense of a team
and wagon as well as a half dey of one men's time. The man~
ager of the farm claims this to be a saving of 32.50 per day
or a return of epproximately 20% on the investment.

Tne construction is very simple and amply heavy for
the work so that repairs will be very light. The design is
also one that presents an attractive aprearance on the land-
scape,

These conveyors were designed by the writer and in=
stalled under his direction and so far as known they are the
first of this type to be used. Shortly after the above in=
Stallation es made the deiry at the “Imendorf Parm of Lex=
ington, ry., w&s elso equipped with the same kind of a con-

veyor,
oh. 733.

Continuous Conveyors for Handling Materials.

Conveyor for Handling Ban&nas at Docks

to ana from Holds of Ships,

The b&énana conveyor is used for transferring bunches
of bafanss from docks into the holds of ships which transport
them to the merkets of the world. It can also be used for
unloading from ship to dock. The machine consists of a struc
tural steel frame for supporting the machinery parts and run-
ways, the conveyor itself, with the necessary gearing and
transmission machinery for driving it, and a steam engine,
Steam sucply being obtained from the ship. A general erec=
tion of the complete machine is shown on drawing 0-2890-10,
sheet 72,

The structural steel frame consists of two trusses
latticed together at top and bottom to form a box and is
made up of standard sizes of angles and @ bars, It is ar-=
ranged to hinge on the dock and extend out from Same over
the vessels whicn are moved along the wharf for receiving
or discharging their cargoes. A steel platform is provid=
ed at the wharf for the hinge shaft of the frame, and also
the engine, so as to distribute the weight of the whole con
veyor over a considerable space on the dock, and also to make
it possible to move the apparatus intect from one dock to
another. The platform is made of standard steel channels
placed edgewise and provided with an angle riveted to the
back of same so as to give a good footing. The tops of

the channels are covered with 2" steel plate. Two short
Sh. 734.

Continuous Conveyors for Handling Naterials.

sections of I beams are riveted on top of the platform and
directly over two of: the supporting channels for carrying
the hinge shaft bearings. The hinge is made by bolting a
solid box in an inverted position to the lower cords of

the two trusses, also one to e&ch of the two sections of
I-beems on the platform and passing a shaft thru the four
bearings. The bearings carried by the platform are spaced
so as to come just outside of those on the frame, thus mak~
ing the distance center to center of the bearings at either
side of the frame equal to the length of the bearings and mak-~
ing the bending stress in the hinge shaft as small as pos~
Sible. The trusses of the frame are 3'~3" deep from back
of the 4 bar which forms the upper chord of truss to back of
the bottom chord angle. The Yarren type of truss was used
so as to t:ke oare of the different stresses Caused by the
various positions encountered in raising and lowering. The
upper chords of the trusses are made of Z bars so that the
inner leg of same could be used for the upper runway of

the conveyor, and the outstanding leg for connecting the
cross ties and bracing between the two trusses, The run-
way for the lower or return strand of conveyor consists of
an angle carried by the diagonals of the trusses and set
out from same by washers so as to bring the back of the up-
standing leg of the angle on a line with the web of the Z
bar above. This brings the horizontal leg of the angle
central below the inner leg of the Z, thus keeping the con=

veyor chains in line. The upper end of the frame is pro-
 
Sh. #35.

Continuous Conveyors for Handling Materials,

yided with heavy plates which are drilled for attaching a
hoisting rope which passes thru a set of blocks and sheaves
and is fastened to the steam Capstain or hoist of the ship
being loaded or unloaded, when the frame is to be raised

or lowered as the case may be.

It was necessary to keep the frame as compact as
' possible and as the conveyor tekes up all of the space in-~
Side of the frame it was impossible to have diagonals in
the cross section to. prevent the frame from racking, con-~
sequently, the upper end of the trusses are given a slight
curve or bend to stiffen the frame and also to give a
better appearance. It is also impossible to have thru
corner shafts at the upper end of the frame with this style
of conveyor unless very large sprocket wheels are used.

So, instead, brackets were built out from the trusses at the
upper end to carry two bearings for each of the stub cor=
ner shafts.

The frame is shown in detail on drawing 0- 2890-10,
sheet Al.

The conveyor is made up of two equal matched strands
of #18 JuFYREY Malleable Roller Chain with T-1 attachments
spaced 48" apart in the chain. The chains are spaced apart
by pieces of 1" standard pipe which fit over the T-1 attach-
ments and are held in place by cotter pins which extend thru

the end of the pipe and the attachments. Heavy canvas is

stretched across the pipe spacers loosely so as to hang be-~
Continuous Conveyors for Handling Materials.

tween same end form a pocket for the bunches of fruit on the
vertical strand of the conveyor as well as on the inclined

or horizontal section. The chains are carried by runway
angles extending inside of the frame on either side. These
keep the chains in perfect alignment and are wide enough
apart to allow the canvas and fruit to hang between same.

The conveyor was built with two stub head shafts, each of
which is driven from the countershaft by a pair of spur
gears. The countershaft is in turn driven by chain and
sprockets from the steam engine. After the conveyor was
completed it was found necessary to replace the two stub

head shafts with one thru shaft and to place a drum, heavily
padded with felt, on seme, for discharging the bananas
properly. This drum is about the same diameter as the sprock=
et and rolls the fruit out on a table instead of dropping it
on same. The hanging shaft was also eyuipped in this manner,

‘The engine is located on the steel platform above
mentioned. The piping for it is carried to the edge of the
wharf where it is connected to the steam supply on the boat
by means of a steam hose.

The machine has &@ capacity of 900 bunches of ban-
anas per hour. This amount could be increased, however, if
it were possible to cet the fruit onto the machine and take
it away any faster. It is an improvement over the old meth=
of of hand loading, the work being accomplished much more

rapidly and with less damage to the fruit.
Sh. 437.

Continuous Conveyors for Handling Naterials.

Apron Conveyors.

Drawing 0- 3290-11, Sh. #1, and Fhotographs ‘os.
4065, 4065 and 40°¢4 show the general arrangement of an
apron conveyor built for the Gendron Wheel Co. of Toledo,
Ohio. This company manufactures bicycle wheels, sulky
parts, baby buggies, toy carts, wagons, leather cushions,
etc. The conveyor is used to transfer these various
erticles from the factory building to a storage building
where they are held pending shipment. The ground space
between these two buildings is taken up by small shop
buildings which are one and one and one half stories high.
There is no system or regularity in their location and
arrangement. For supporting the structural frame work of
the conveyor, it was desirable to have two steel frame
bents in the span and it was necessary to locate these
bents so that one would rest on the wall of a brick build
ing and so that the other could extend to the ground be-
tween two buildings whose eaves clear each other by about
le inches.

The work of securing data and plans of locations
of these buildings with reference to the main buildings
was very difficult, in fact, a local engineer had refused
to undertake the task, However, he rendered the writer

great assistance by the loan of instruments which aided in

the success of the undertaking.

The conveyor is arranged in a steel truss frame
Sh. #38,

Continuous Conveyors for Handling lLlaterials.

which is supported by the building walls at each end and
by two bents intermediate in the span. A walkway is pro-
vided the full length on one side and the complete frame
is enclosed with a corrugated iron housing.

The conveyor is made up of @ malleable roller chain
6" pitch with 3" rollers and 11/16" pins. Every other link
is provided with an attachment extending out on one side for
fastening to wood flights. The overall width of the chains
is about %O0 inches. Both carrying and return strand are
carried by the chain rollers on angle irons running the full
length of the frame.

Power for driving is furnished by 6 5 H.P. motor
which is hung from the ceiling of the room into which the mater~
ial is discharged. The motor connects by belt with a counter~
Shaft located in the head frame which in turn transmits power
to the driving sheft thru a pair of spur gears. Blue prints
from plates i0s. 4055, 4065 and 40°4 are from photographs
taken after the equipment was in operation,

The material handled is gathered from the different
floors of the factory building by a platform elevator and
discharged at the receiving end of the conveyor. In the .
Storage building the material is discharged just in front
of e platform elevator for distribution to the various floors
of this building.

Before the conveyor was installed it was the practice

to transfer all material from one building to the other with

smal] two wheeled hand trucks, ‘Now, with the conveyor, the
3h e #3) e

Continuous Conveyors for Handling Naterials.

transfer is made more easily as well as more economically.

Conelusion.

 

vonsidering the subject of conveying machinery as
a whole, it presents a varied and interesting field of en-
deavor to the engineer. As has been pointed out, in many
respects, it is still in its initial stages, and new appli-~
cations continually call for the best ability and endeavor
of the engineer in solving just such problems as outlined
above.

And finally, to recapitulate, as a labor saving
device it occupies a field of its own, both in the greater
facilities afforded in operation, and in the increased out-
put of a given plant, as well as in furthering the produc~
tion of ae more perfect product. It must take its place as
a factor of no mean imrortemce in the present day tendency
toward development of resources, conservation of energy and

purity stendards for all products,
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