U.S. patent number 3,876,089 [Application Number 05/363,394] was granted by the patent office on 1975-04-08 for conveyor equipment, especially cargo loading and unloading equipment for a vehicle.
This patent grant is currently assigned to J. J. Barham, Giles Clegg, Jr.. Invention is credited to William H. Moser.
United States Patent |
3,876,089 |
Moser |
April 8, 1975 |
Conveyor equipment, especially cargo loading and unloading
equipment for a vehicle
Abstract
There is disclosed a conveyor device and frame suitable for use
as a vehicle bed which includes a slatted floor carried on lugs
that are in turn mounted on a closed loop cable. The cable is
trained over and driven by notched sheaves at each end of the
conveyor frame.
Inventors: |
Moser; William H. (Paris,
TX) |
Assignee: |
Clegg, Jr.; Giles (Dallas,
TX)
Barham; J. J. (Paris, TX)
|
Family
ID: |
23430036 |
Appl.
No.: |
05/363,394 |
Filed: |
May 24, 1973 |
Current U.S.
Class: |
414/528; 198/822;
198/850 |
Current CPC
Class: |
B60P
1/38 (20130101) |
Current International
Class: |
B60P
1/38 (20060101); B60P 1/36 (20060101); B60p
001/38 (); B65g 017/10 () |
Field of
Search: |
;214/83.36
;198/195,196,197,199,181,182 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
441,325 |
|
May 1912 |
|
FR |
|
185,738 |
|
May 1956 |
|
OE |
|
798,156 |
|
Jul 1958 |
|
GB |
|
Primary Examiner: Spar; Robert J.
Assistant Examiner: Peperner; Leslie J.
Attorney, Agent or Firm: Clegg, Cantrell & Crisman
Claims
What is claimed is:
1. Conveyor apparatus comprisinsg:
a generally rectangular support frame including at least two
longitudinal beams extending the length of said frame, a plurality
of cross beams connected between said longitudinal beams, and means
for supporting said frame to permit the lower run of the conveyor
to pass below the major portion of said frame;
first and second parallel spaced apart axles extending transversely
thereof adjacent opposite ends of said frame;
axle support means for said axles mounted on said frame adjacent
said opposite ends of said longitudinal beams;
at least one pair of coplanar notched sheaves, one of said pair
being mounted on said first axle and the other of said pair being
mounted on said second axle;
a conveyor cable trained over each coplanar pair of sheaves in a
closed loop having upper and lower runs;
said conveyor cable being provided with lugs fixed thereon at
spaced intervals, said lugs being configured to engage notches on
said sheaves;
a plurality of floor slats, one of said floor slats being directly
connected to each of at least a majority of said lugs on said
conveyor cable, the lugs connected to floor slats being contiguous
to one another, the point of connection of a floor slat to a lug
being between the ends of the floor slat;
at least a pair of rails mounted on said frame and extending
longitudinally thereof between said pair of axles in position to
support floor slats connected to lugs located in said upper run
with said slats sliding directly on said rails; and
means for driving at least one of said sheaves.
2. Apparatus in accordance with claim 1 in which said conveyor
cable comprises a length of cable whose two ends are attached to a
single one of said lug to form said closed loop.
3. Apparatus in accordance with claim 2 in which said single lug
has a pair of divergent passageways formed therein for receiving
the two ends of said length of cable, said passageways being angled
to permit the ends of the cable to enter the single lug on opposite
sides of the lug at opposed positions aligned with the cable
rung.
4. Apparatus in accordance with claim 1 in which one of said axle
support means includes positioning means for varying the
longitudinal separation of said axles.
5. Apparatus in accordance with claim 1 and further comprising a
cargo body having side walls and an end wall, said side walls being
supported by said longitudinal beams.
6. Apparatus in accordance with claim 1 in which evey lug has a
floor slat connected thereto.
7. Apparatus in accordance with claim 1 in which adjacent ones of
said slats overlap one another.
8. Apparatus in accordance with claim 1 including a plurality of
pairs of coplanar sheaves, the number of pairs of sheaves being n
and the number of rails being at least n +1 with the plane of each
pair of coplanar sheaves positioned between a pair of rails.
9. Apparatus in accordance with claim 1 wherein said support frame
includes a pair of transverse means, one positioned adjacent each
end of said frame and means for supporting the longitudinal beams
and cross beams above the transverse beams to define a slat in
which the lower run passes.
10. Apparatus in accordance with claim 9 and further
comprising:
means connecting one of said transverse beams to road wheels and
the other of said transverse beams to a fifth wheel thereby
adapting said equipment for use as a semi-trailer.
Description
BACKGROUND OF THE INVENTION
This invention relates to conveyor equipment, especially conveyor
equipment which is adapted for loading and unloading a vehicle. The
equipment of the invention is useful in many conveyor type
applications. In its more specific aspects, it is concerned with
cargo carrying, and loading and unloading equipment for, or
comprising part of, a transportation vehicle such as a truck or
semi-trailer.
The loading and unloading of cargo vehicles has been a continuing
problem impairing the efficiency of their use. For road vehicles
carrying bulk cargo, the dump truck or dump trailer configuration
has long been popular for unloading purposes, despite its
disadvantages which include the necessity for heavy structural
equipment which amounts to dead weight so far as the hauling
capacity of the vehicle is concerned, a dangerous raising of the
center of gravity of the vehicle during dumping operations, and
difficulty in controlling the rate of discharge of the bulk
material. More recently, as exemplified by my U.S. Pat. No.
3,482,717, entitled "Self-Unloading Trailer" and U.S. Pat. No.
3,247,983, to Thompson, entitled "Truck Unloading Structure", the
use of bulk cargo bodies having belt conveyors forming the bed or
floor of the cargo body has begun. While such constructions
overcome many of the disadvantages of dump trailers or dump trucks,
the relatively expensive large endless conveyor belts involved (and
the relatively complex understructure involved in the Thompson-type
vehicle) have limited the application of such vehicles.
Slat-type conveyor belts have been proposed in the past, both for
general cargo vehicles and for bulk cargo vehicles. In this
connection see U.S. Pat. Nos. 1.081,697, 1,375,535 and 1,558,164.
Such slatted conveyor vehicle beds have uniformly employed chains
working over sprocket wheels to carry the slats of the conveyor.
Such chains are expensive, prone to breakage, sensitive to
alignment with respect to the sprocket wheels, and inherently
require a large amount of slackness and tolerance between slats, to
accommodate the manufacturing tolerances involved in each link of
chain.
The disadvantages of prior slatted conveyors utilizing chains in
other applications are similar to those encountered when such
conveyors have been employed in vehicle beds.
In accordance with the present invention a conveyor structure,
especially suited for use as loading and unloading equipment
forming the bed of a cargo vehicle, is provided which, while it is
of the slatted conveyor type, has substantially none of the
disadvantages of such conveyors as employed heretofore, and which,
by virtue of its simple and economic construction, retains all of
the advantages gained by the before-mentioned conveyor belt vehicle
bed constructions, while eliminating the costly large endless
conveyor belt involved in such constructions.
SUMMARY OF THE INVENTION
The conveyor structure and vehicle bed of the present invention
includes a specially constructed slatted conveyor which is built
upon an improved frame that may also comprise the vehicle frame.
Conveyor chains driven by sprocket wheels and their attendant
disadvantages are eliminated. Sheaves are mounted for rotation on
the frame and are arranged in one or more co-planar pairs, one
sheave of each pair being located at each end of the frame. The
sheaves are notched to accommodate and drivingly engage spaced lugs
carried by a cable which is trained in a loop over co-planar
sheaves. The side of each lug which faces outboard of the cable
loop is attached to a conveyor slat. The frame is also desirably
provided with longitudinal rails on which the slats ride and are
supported when they are moving along or positioned on the upper run
of the cable loop. By this construction, a slatted, but movable
vehicle bed floor is obtained. In accordance with the invention,
the slats may be arranged in either of two configurations; in one,
the slats are closely abutting one another; in the other, the slats
lap one another. Both arrangements result in the formation of a
surface which is substantially impervious, and which will not leak
bulk material such as gravel. Since conventional sprocket-driven
conveyor chains are eliminated and replaced by a driving cable, all
parts of the conveyor mechanism, including all of the slats,
commence movement substantially at the same time when the conveyor
mechanism is started, there being no chain slack to be taken up.
The absence of chain slack, and the absence of a need to
accommodate it, make it possible to have the slats forming the
vehicle bed floor in continuous close abutment to one another, if
that configuration of slats is employed.
In accordance with the invention, the slatted conveyor structure is
superior to a conveyor belt structure in that it is more economical
in construction, and because in the event of damage or heavy wear
in one localized section of the conveyor it is possible to remove
and replace only those slats which are in poor condition. By
contrast, a damaged or locally worn conveyor belt must in most
instances be completely replaced.
It is an object of the present invention to provide a slatted
conveyor structure which overcomes the disadvantages of prior
structures of this type, and at the same time is superior to
conveyor belt structures in many respects.
It is an object of the present invention to provide an improved
conveyor mechanism, and more particularly, such a mechanism which
is specially adapted to serve as a vehicle bed for cargo vehicles,
both of the bulk cargo type and of the general cargo type.
It is a further object of this invention to provide a conveyor
structure and vehicle bed which is of simple, rugged construction,
easy to maintain, and reliable to operation.
Still another object of the invention is the provision of improved
transportation vehicles incorporating as part thereof the conveyor
structure of the invention.
The foregoing objects, together with other objects and purposes can
better be understood by consideration of the detailed description
which follows together with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified perspective view, with parts omitted, of a
conveyor constructed in accordance with the invention;
FIG. 2 is a side elevational view of a portion of the upper run of
one embodiment of the conveyor of the present invention showing one
preferred slat arrangement;
FIG. 3 is a fragmentary isometric view of a portion of the upper
run of a conveyor constructed in accordance with the invention,
illustrating an alternate form or shape for the conveyor slats;
FIG. 4 is a side elevational view with parts broken away and with a
section broken out, of a semi-trailer constructed in accordance
with and incorporating the present invention;
FIG. 5 is a rear sectional elevational view of the semi-trailer of
FIG. 4, the section being taken along the line 5--5 of FIG. 4;
FIG. 6 is a plan view of an enlarged scale with parts broken away,
and with a section broken out, of the conveyor structure of the
semi-trailer of FIGS. 4 and 5;
FIG. 7 is a sectional elevational view of the conveyor structure of
FIG. 6, the section being taken on line 7--7 of FIG. 6;
FIG. 8 is a isometric view of an enlarged scale of the sheave and
cable structure forming a portion of the conveyor apparatus of the
invention, with certain parts shown in ghost outline;
FIG. 9 is a fragmentary elevational view of an enlarged scale of
the sheave, conveyor, and one form of slat structure of the
conveyor apparatus of the invention;
FIG. 10 is a fragmentary isometric view of the rear portion of the
semi-trailer of FIGS. 4 and 5;
FIG. 11 is a plan view of the sheave of FIG. 9;
FIGS. 12A, B, C and D are side, front, plan and isosmetric views
respectively of a cable lug employed in accordance with the
invention;
FIGS. 13A, B, C and D are side, front, plan and isometric views
respectively of a cable splicing lug employed in accordance with
the invention;
FIG. 14 is a side elevational view of an alternate form of conveyor
lug employed in accordance with the invention, the view also
showing a slat, and a portion of a cable;
FIG. 15 is a side elevational view of another alternate form of lug
employed in accordance with the invention;
FIG. 16 is an exploded sectional view of the lug of FIG. 15, the
section being taken on the line 16--16 of FIG. 15; and
FIG. 17 is a isometric view of another form of splicing lug
employed in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 a conveyor constructed in accordance with the invention
is designated generally as 10. It is generally rectangular in plan
view and has an upper run 11 and a lower run 12. At the ends of the
conveyor the runs are trained over sheaves 13 and 14 which are
shown very diagramatically in FIG. 1 because of its scale, but
which are shown in more detail in other figures discussed
hereinbelow. The load carrying surface of the conveyor 10 is
comprised of slats 15, which in the embodiment of FIG. 1 are flat
rectangular members extending transversely across the conveyor, in
closely abutting relationship to one another.
FIG. 2 shows the structure of the conveyor in greater detail, and
also illustrates another arrangement of the slats. From FIG. 2 it
can be seen that the conveyor 10 includes a cable 16, which is
preferably constructed of steel. Mounted on the cable at evenly
spaced intervals are lugs 17, and slats 15 are attached to the lugs
17. Assuming that only a single cable is used in a given conveyor,
one slat 15 is attached to each of its lugs 17, at least in the
upper run. (More than one cable 16 may be employed in accordance
with the invention as discussed more fully hereinbelow.)
In the embodiment of FIG. 2 the slats 15 are arranged in lapping
relationship, with each slat having its left edge above its
neighbor to the left and its right edge beneath its neighbor to the
right. Such an arrangement is of particular advantage when the
conveyor is employed to handle bulk material such as gravel or
aggregate because there is less spillage of such material into the
works of the conveyor at the turnaround points.
FIG. 3 illustrates a form of the conveyor of the invention in which
two cables 16 are employed, each carrying lugs to which slats are
attached, and in which the slats 15 are in lapping relationshsip as
explained above in connection with FIG. 2. In addition, the ends of
slats 15 are bent upwardly to provide a conveyor surface which is
generally trough shaped. This configuration is particularly useful
in applications of the conveyor structure where bulk material is to
be handled, and no stationary side walls for the conveyor are
provided or desired.
In FIGS. 4-7 and 10 a semi-trailer constructed in accordance with
and incorporating the invention is designated generally as 20.
FIGS. 4 and 5 show that it includes trailer wheels 21 carried on
axles 22 which are journaled through axle posts 23. For the sake of
simplicity the conventional spring suspension mechanism associated
with axles 21 and axle posts 23 is omitted from the drawings.
Mounted above the axle posts 23 is a transverse beam structure 24
which extends substantially across the full width of the trailer.
Beam structure 24 may be built up of a plurality of smaller beams,
and is so proportioned as to constitute one of the principal load
bearing structural members of the frame of the semi-trailer. At the
front end of the semi-trailer 20, a second transverse beam
structure 25 is provided. It too may be built up of a plurality of
smaller beams, and is proportioned to constitute a principal load
bearing portion of the trailer frame. Attached to front transverse
beam structure 25 is the upper half 26 of a conventional fifth
wheel unit. In operation, the upper half 26 of the fifth wheel is
connected to lower half 27 which is in turn supported by frame 28
of a conventional truck tractor, only a fragment of which appears
in FIG. 4.
A pair of longitudinal side beams 29 are mounted on and run between
transverse beam structures 24 and 25. A plurality of cross beams 30
are transversely mounted on longitudinal beams 29. A cargo body
designated 31 is mounted on the frame of the semi-trailer 20, and
is supported principally by cross beams 30. In FIGS. 4 and 5 the
cargo body shown is of the bulk cargo type, although the invention
may also be employed to advantage for general cargo, in which case
a general cargo body can be mounted upon cross beams 30 in a manner
similar to the mounting of the bulk cargo body 31. It should also
be noted that in some applications of the invention a flat-bed
style trailer is desirable, in which case no carbo body
superstructure of any kind is required.
The structure of the conveyor forming the vehicle bed of the
semi-trailer 20 can best be understood by a consideration of FIGs.
6 and 7, together with some reference to FIGS. 4 and 5. As is shown
in FIG. 6, the cross beams 30 are interrupted by four internal
longitudinally oriented beams 32. The cross beams 30 and
longitudinal beams 32, are welded together at their points of
intersection to form a grid-like frame. A series of runners is
formed of an inherently slippery material such as oak are mounted
longitudinally on the top of said frame. Preferably the top surface
of runners 35 is coated with a wear layer 36 formed of a synthetic
rubber.
At the rear end of trailer 20 (at the top of FIG. 6) four pillow
blocks 37, are mounted, one at the end of each of longitudinal
beams 32. Journaled through the pillow blocks is an axle 40. At the
front end of trailer 20 (bottom of FIG. 6), a conveyor tension
adjusting structure is provided, which consists of three pairs of
slotted plates 41 abutted against the frontmost cross beam 30.
Slotted plates 41 are joined at their front ends by a cross member
42. Each pair of slotted plates 41 has a pillow block 43 adjustably
positioned on it. Associated with each pillow block 43 in a pair of
adjusting screws 44 which work against nuts 45 welded to the
frontmost cross beam 30 and, abuttments 43A on pillow blocks 43. A
front axle 46 is journaled through pillow blocks 43 and extends
across the front of the unit.
Rear axle 40 carries three rotatable sheaves 47, and front axle 46
also carries three rotatable sheaves 48. On the front axle the
sheaves are positioned between the posts of the pillow blocks
43.
For purposes of the present discussion, a rear sheave 47 and a
front sheave 48 are regarded as a pair when they are arranged
coplanarly. In the embodiment of the invention shown in FIGs. 4-7
there are three such coplanar pairs of sheaves provided. It should
be understood however that in some embodiments of the invention a
single pair may suffice, while in other embodiments it may be
desirable to provide two, or more than three such pairs. An example
of the latter case is a trailer or other transportation vehicle
designed to carry extraordinary heavy loads.
Trained around each of the pairs of sheaves is cable 16, which is
preferably constructed of steel. Cable 16 is arranged in a closed
loop extending longitudinally of the semi-trailer 20 and has an
upper run and a lower run as a consequence of the vertical planes
in which the sheave pairs are arranged.
The structure and operation of the drive system for the conveyor
mechanism of the invention can best be understood by a
consideration of FIGS. 8, 9 and 11, taken together with the views
of the semi-trailer appearing in FIGS. 4, 5, and 10. From the
enlarged views it can be seen that sheave 47 is a modified form of
a conventional pulley sheave. It has a hub 57, a bore 58 to
accommodate an axle 40 and a disc portion 59. Around the periphery
of the disc portion 59, there is provided a relatively deep groove
60 in which cable 16 is accommodated. Groove 60 serves to restrain
sideward displacement of cable 16. Sheave 47 differs from
conventional sheaves in that it is provided with a series of
notches 61 around the periphery of disc 59. Notches 61 are
substantially uniformly spaced, as appears most clearly in FIG. 9.
Cable 16 has mounted on it in fixed position a series of lugs 17.
The lugs, and their means of mounting, are more fully described
hereinbelow in connection with FIGS. 12-17. As best appears in
FIGs. 8, 9 and 4, lugs 17 are spaced along cable 16 at distances
such that they fit into and enagage the notches 61 of sheave 47
when cable 16 passes around sheave 47 in the groove thereof. It
should be noted that since lugs 17 extend radially inwardly from
cable 16, the notches 61 on sheave 47 are of a depth such that they
extend radially inwardly from the floor of the groove 60.
Attached to each lug 17, on the radially outward side thereof is a
slat 15. Slats 15 are generally board-shaped, and are positioned
with respect to lugs 17 so that they extend parallel to the axle 40
which carries sheave 47. As appears best in FIG. 10, slats 15,
taken together, establish a movable vehicle bed floor 64 when they
are positioned in the upper run of cable 16. In the embodiment of
FIGS. 4-11, the width of slats 15 is such that adjacent slats are
in close abutment to one another so that the floor 64 is
substantially impervious. The length of slats 15 is such that they
extend substantially across the full width of the transporation
vehicle; their length is at least adequate to extend across the
floor of the cargo space. As can be seen in FIGS. 5 and 7, the
sloping side walls 62 of cargo body 31 approach the vehicle bed
floor 34 closely, and angle members 63 close the space behind the
lower edges of side walls 62 to prevent packing of bulk material
therein.
Spaced lugs 17 are provided throughout the length of the looped
cable 16 so that lugs are always available for engagement with both
the front and rear sheaves 48 and 47. In the preferred embodiment,
each lug has associated with it a slat 15. However, in order to
save on weight and material, in some applications of the invention
half or somewhat less than half of the slats may be omitted. Stated
differently, it is necessary only to provide sufficient contiguous
slats to establish a floor in the upper run of cable 16. When the
invention is employed in a bulk cargo vehicle, somewhat more than
half of the iength of cable 16 should be fitted with slats to
accommodate spillback of the bulk cargo as the slatted fllor is
moved in an unloading operation as discussed below.
The remainder of the conveyor structure of the invention can be
seen from FIGs. 4-7 where it appears clearly that cross beams 30
are so proportional that they fit between the upper and lower runs
of cable 16. Cross beams 30 support above mentioned rails 35 which
extend longitudinally of the frame of the trailer. They are so
proportioned that their upper surfaces underlie and support slats
15 located in the upper run of cable 16. Rails 35 are preferably
formed of a strong but inherently slippery material, such as
oak.
As appears from FIG. 4, at the forward end of the semi-trailer, a
pulley (not shown) is journaled onto an end of axle 46, and a drive
motor 67 is mounted on the frame of the trailer and connected to
the pulley on axle 46 by belt 68. Drive motor 67 may be a
self-contained power plant such as a gasoline engine, or a power
plant driven by an auxiliary system of the truck tractor, such as
an air motor. Drive motor 67 is desirably reversible and of
variable speed so that conveyor speed may be controlled
independently of vehicle road speed, and correlated therewith in
any desired manner. As is shown in FIG. 10, rear axle 40 is
desirably also provided with a drive motor 66, whose operation is
correlated with that of front drive motor 67.
In FIGs. 12-17 there are illustrated the two basic types of lugs 17
employed in accordance with the invention. The lugs illustrated in
FIGS. 12 and 14-16 are variations of the type used for all portions
of a cable 16 except the portion at the ends of the cable. The lugs
illustrated in FIGs. 13 and 17 are two forms of splicing lugs by
which the two ends of cable 16 are joined to form it into a closed
loop trained about the sheaves.
From FIG. 12B it can be seen that the standard lug 17 is generally
wedge-shaped in elevation, while FIGS. 12A and 12C show that it is
generally rectangular in side elevation and in plan view. (When the
lapped slat configuration shown in FIGS. 2 and 3 is used, the tops
of lugs 17 should preferably be angled to accommodate the lapping,
as illustrated in FIG. 2.) Each lug 17 is provided with a cable
hole 69 which passes through it from one side to the other. It is
somewhat larger in diameter than cable 16 which is passed through
hole 69. A cross hole 70 is provided in each lug and is internally
threaded to accommodate a set screw 71. When the set screw is
positioned in the cross hole, it compresses and distorts somewhat
the cable 16, thereby effectively attaching the lug 17 to the cable
tightly enough that it will not be displaced along the cable under
the influence of the ordinary forces encountered in operation of
the conveyor system.
The lug 17 illustrated in FIG. 14 is substantially the same in
shape as that illustrated in FIG. 12, and is provided with a cable
hole 69 in the same manner. However, the means of attachment to the
cable, and to the slat 15, differ, in that a vertically extending
slot 72 is formed in the lug, and a U-bolt 73 is fitted in slot 72.
When nut 74 (a pair of such nuts are employed, one on each leg of
the U-bolt) is tightened, the U-bolt 73 grips the cable 16 tightly,
thus affixing the lug to the cable, and at the same time attaches
the slat 15 to the lug.
The lug 17 shown in FIGS. 15 and 16 is also of the same shape as
that shown in FIG. 12, and is also provided with a cable hole 69
through which cable 16 is passed. A sideward oriented slot 75,
having legs at one end to accommodate the legs of a U-bolt 76 is
provided in lug 17. When U-bolt 76 is inserted in slot 75, and nuts
77 are tightened on the legs of the U-bolt 76, the cable is again
tightly gripped and the lug fixed on it.
A comparison of FIG. 13 with FIG. 12 reveals that in external
configuration the splicing lug 17 of FIG. 13 is the same as that of
the standard lug 17 illustrated in FIG. 12. A pair of curved cable
holes 78 and 79 are provided in splicing lug 17. These holes enter
the sides of the splicing lug, as cable hole 69 entered the sides
of the standard lug. However, interiorly of the splicing lug 17 the
cable holes 78 and 79 are curved substantially 90.degree. and issue
from opposite faces of the splicing lug. A vertical set screw hole
80 is provided in the splicing lug and is so positioned that it
intercepts both of the curved cable holes 78 and 79. A set screw
81, when threaded into hole 80 engages and distorts the portions of
cable 16 which are disposed within cable holes 78 and 79, and
effectively links the two ends of the cable together to form a
closed loop. The portions of the cable 16 issuing from the faces of
the splicing lug may be conveniently trimmed substantially flush
with the faces of the splicing wedge, although such parts are shown
projecting from the faces in FIGS. 13C and 13D for clarity of
illustration.
The splicing lug 17 shown in FIG. 17 has the same wedge shape as
those in FIGS. 12 through 16, but it is longer than any of those
lugs. A consideration of the shape of notches 61 of sheave 47 as
shown in FIGS. 8, 9 and 11 will demonstrate that such greater
length will not interfere with the passage of the lug of FIG. 17
around the sheave. Lug 17 of FIG. 17 is provided with a pair of
cable holes 82 and 83, which cable holes enter the lug centrally
thereof and are angled to pass through the lug toward one side
thereof. The ends of cable 16 are passed through cable holes 82 and
83 and are then looped back toward lug 17 to pass through clamping
cable holes 84 and 85. Set screws 86 are mounted in holes in the
ends of lug 17 to engage the clamp the portion of cable 16 passing
through the cable holes 84 and 85. Again, the portions of the cable
16 issuing from the cable holes 84 and 85 may conveniently be
trimmed substantially flush with the lug, although such parts are
shown projecting in FIG. 17 for clarity of illustration.
While the conveyor system of the present invention, especially as
applied to a vehicle, may be constructed of a variety of materials,
it is preferred that the frame, as discussed above, be fabricated
of steel for strength, with the exception of the rails 35, which
are most conveniently formed of a slippery, but strong, wood such
as oak. Cables 16 should also be of steel for strength. Lugs 17 may
be of steel, or of another strong material. Slats 15 may be of
steel, wood, or aluminum, but aluminum is preferred for its
combination of strength and light weight. When slats 15 are formed
of aluminum, they may be welded or brazed to the lugs 17.
Alternately, the slats may be attached to the lugs by screws or
bolts, one example of such attachment being illustrated in FIg. 14
discussed above.
When the invention is applied to a bulk cargo vehicle of the kind
illustrated in FIGS. 4, 5 and 10, it finds its principal utility in
unloading operations. The rear gate 87 (see FIG. 10) of the trailer
may be opened partially and fixed in such partially open position
to serve as a doctor blade. Drive motors 66 and 67 are then
operated to move the upper run of the conveyor in the leftward
direction as FIG. 4 is drawn. Bulk material in the cargo space of
the semi-trailer is thus propelled leftwardly and out of the
semi-trailer onto the ground. At the same time the vehicle may be
pulled by its tractor to the right, as FIG. 4 is drawn, thus
affording uniform distribution of the bulk material onto the road
surface which is its point of use. When the invention is applied in
a general cargo vehicle, packages and the like are placed on the
lefthand end of the floor of the conveyor from a loading dock, and
drive motors 66 and 67 are operated to carry them forward in the
cargo space of the trailer. When it is desired to unload such
packages at a point of delivery, drive motors 66 and 67 are
operated in the opposite direction to move the packages from within
the cargo space of the trailer to the rear of the trailer where
they may be removed to a loading dock.
* * * * *