Note: Descriptions are shown in the official language in which they were submitted.
FIELD OF THE INVENT ION
This invention relates to an article handling system,
and more particularly to a system for shifting and crienting
!containers withi.n the confines of a truck or tractor-drawn trailer
¦body.
¦ This invention is concerned with truck-mounted
mechanized article handling systems which may be easily fitted
;to existing truc~ bodies, including -tractor-drawn tràiler bodies.
~The mechanized system is particularly adapted for use with
standarized cohtalners although it is to be understood that
the invention is not limited specifically thereto. The system
of this invention is designed to facilitate the general loading
and unloading of the containers, but more importantly a primary
purpose of the system is to permit access to a particular container
regardless of its position on the truck relative to the rear
opening without having to remove other containers fro~ the truck.
BACKGROUND OF THE INVENTION
A number of systems are known in the prior art for
facilitating the general loading and unloading of the contents
of a truck. Generally, these systems take the form of roller
¦conveyors, pushing and pulling power elements or the like, and
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do not permit access to a container at the forward end of the
truck without removing other containers. It is known to use
an endless power conveyor on a truck body which is designed to
deliver a particular container to the rear of the truck. However,
such systems are impractical from a cost standpoint in that
entirely too much free space must be allowed for the containers
on the conveyor to make the turns around the sharp corners of
the truck body. Further, the mechanism of the conveyor itself
has generally been of a rather bulky construction further
l~ reducing the space that is available for the hauling of cargo.
The s~stem of this invention permits the carrier to maximize
the -usage of the space within the truck body.
This invention is an improvement oSver the article
handling systems disclosed in applicant's~Patent No. 3,802,588,
dated April 9, 1974, entitled ARTICLE HANDLING SYSTEM and U.S.
Patent No. 3,777,916, dated December 11, 1973, also entitled
ARTICLE HANDLING SYSTEM, both of which issued to the applicant
herein.
The basic concept under which the system disclosed in
those patents operates involves the sectioning of the truck
body into a plurality of contiguous, generally square areas
aligned in two longitudinal rows. Each of the squares receives
a container with the exception of one which is left blank.
By subjecting the two rows of containers to a plurality of
sequenced rectilinear movements using the blank space, a particular
container may be brought to a particular location on the floor of
the truck body without having to remove any of the containers
from the truck, thereby saving many man hours in unloading the
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truck. Wear and tear on the truck body is minimized in that, since a con-
tainer is delivered to the rear opening mechanically, a fork lift need not
enter the ~ruck for the removal of a container located at the front.
This invention is designed on the basic concept disclosed in those
earlier patents but constitutes an improvement over the apparatus disclosed
in those patents for moving the loads in a rectangular endless path.
SUMMARY OF THE INVENTION
As stated above, the apparatus of this invention constitutes an
improvement over those mechanisms disclosed in applicant's prior patents in
that it is, for the most part, simpler in construction, has fewer parts,
and is more readily installed in truck bodies. Further, the apparatus of
this invention is more versatile in that by redirecting and rearranging drive
cables on the floor of the vehicle, the system can be changed to operate
either with a double-blank space or a single-blank space and the direction
of movement can be changed.
The invention provides in combination with a vehicle having a load
supporting floor, an article handling system for handling a plurality of
loads of generally rectangular configuration in horizontal cross-section
arranged in two closely adjacent longitudinal rows and substantially covering
2Q the entire floor area of said vehicle with the exception of at least one
void area approximately the size of the area covered by one load, means for
supporting said loads for movement on said floor in four directions, namely,
back and forth longitudinally of said vehicle and back and forth transversely
of said vehicle, first drive means for shifting the loads in said rows in
two of said four directions, second drive means for shifting said loads in
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the other two of said directions, said movements being possible through
utilization of said void area, each of said drive means comprising a
reversible power source, a flexible elongated element attached to said power
source for movement in reversible directions, a pair of load engaging drive
detents attached to said flexible elongated element, underlying said loads,
and drivingly engaged therewith for moving said loads upon activation of
said power source, and means for selectively activating said first and
second drive means to intermittently move said loads through a rectangular
path on said floor.
lQ In one embodiment there is a plurality of load-receiving trays
which are movably supported on casters which in turn are secured to the
vehicle floor. The trays are arranged in the two longitudinal rows on the
vehicle and the void area is either a single blank space the size of one of
the trays or a double-blank space, one for each row depending upon the move-
ment to which the system is geared as will be explained more fully below.
In any event, a particular tray can be moved through a longitudinal row to
an end of the vehicle whereupon it is shifted transversely to the other
longitudinal row to be moved through that row to the other end of the vehicle
whereupon it can be either removed or shifted transversely back to the
2Q other row to repeat the cycle. Cable driven detents or trolleys are mounted
on trackways in the vehicle floor and engage the trays to move them longitu-
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dinally and transversely of the vehicle. The trolleys or detents are recip-
rocated in their trackways by means of cables which in turn are driven in a
preferred embodiment, by hydraulically actuated, double-acting cylinders.
In one of the preferred embodiments, a single double-acting cylinder effects
both transverse movements at either end of the vehicle and a single double-
acting cylinder effects the longitudinal movements through each longitudinal
row. In other words, only two power sources are needed to effect movement
of the loads through the rectangular path. A number of variations of this
basic arrangement are disclosed utilizing the single blank space concept and
the faster, double blank space concept.
BRIEF DESCRIPTION OF T~IE DRA~INGS
Figure 1 is a generally schematic plan view of a preferred embodi-
ment of the article handling system of this invention whereby loads may be
moved in a rectangular path in a counterclockwise direction;
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Figure 2 is a fragmentary view of the system of Figure 1,
more clearly illustratlng the changeover between the transverse
drive means and the longitudinal drive means;
Figure 3 is a view taken on line 3-3 of Figure 2;
Figure 4 is a plan view of the drive detent which engages
and moves the load-supporting trays;
Figure 5 is a side view in elevation of the detent
of Figure 4;
Figure 6 is a front view in elevation of the drive detent
of Figure 4;
Figure 7 is a schematic illustration of an article
handling system similar to that of Figure 1 except that the
cables are so arranged that the load is moved in a clockwise
directlon utilizing the single blank space;
Figure 8 is a further alternative embodiment of the
article handling system of this invention showing the cables
arranged in a different manner for effecting clockwise rotation
of the loads utilizing a single blank space;
Figure 9 is a schematic illustration of an arrangement
of fluid actuated cylinders wherein the tray engaging drive
detents are connected directly to the pi.ston rods of the cylinders
and wherein loads may be moved in the counterclockwise direction
utilizi.ng either a single blank space or a double blank space;
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.
Figure 10 is a schematic illustration of an arrangement
of the article hand].ing system of this invention which effects
clockwise rotation utilizing either a single blank space or a
double blank space;
Figure 11 is a schematic illustration of another
embodiment of the article handling system of this invention wherein
the cables are arranged to effect clockwise movement of the loads
utilizing a douhle blank space;
Figure 12 is a plan view of the arrangement of Figure 1
emphasizing the load supporting rollers and braking strips
affixed to the vehicle floor;
Figure 13 is a partial fragmentary diagrammatical view
of the right lower corner section of each of the embodiments
shown heretofore, emphasizing the offset between the longitudinal
rows to prevent snagging during transverse movements;
Figure 14 is a diagrammatical side view in elevation
of a modified form of this invention; and
Figure 15 is a plan view of the embodiment of
Figure 14.
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The concept upon which this invention is based can bcst
be understood with rcference to Figure 1 wherein 10 generally
indicates an enclosed truck body, in this case, a tractor-drawn
trailer. The trailer includes a floor 12 on which are positioned
a longitudinal drive unit 14 and a transverse drive unit 16
each of which will be described in greater detail hereinafter.
As can be best seen in Figure 1, the trailer is sectioned into
squares aligned in two longitudinal rows, A and B. The squares
in the two rows are numbered Al through A7 and Bl through B7,
0 respectively.
Each of the squares is occupied by a roller supported
tray 22 with the exception of one square which in Figure 1
is square A7. Accordingly, the transverse drive means 16 is
first actuated to shift the tray in B7 to A7. Longitudinal drive
means 14 is then actuated to move the tray in spaces Bl through
B6 to spaces B2 through B7, following which the transverse drive
means 16 is again actuated to move the tray in Al to Bl. The
longitudinal drive means 14 is agaln actuated to move the trays
in A2 through A7 to Al through A6, whereupon space A7 is again
vacant and one cycle is completed. A cycle comprises four
successive movements where a single blank space is used.
Other embodiments are disclosed wherein each of the
squares is occupied by a roller supported tray 22 with the
exception of two squares, for example, squares Bl and A7, which
are left vacant. These vacant areas permit the trays to be
shifted in simultaneous transverse or simultaneous longitudinal
movements as will hereinafter be more fully described. This
effectively halves the time required to move a load through a
complete rectangular path.
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One complete circuit is defined as rcpeating the cycle
until the original arrangement is regained. Thus, it can be seen
that by performing a certain number of operational sequences
a particular container, for example, one occupying the position
in station Al at the front end of the trailer can be delivered to
the position B7 at the rear end of the trailer where it can be
conveniently removed by a fork lift truck or the like without
having to remove any of the other containers from the trailer.
It is also to be observed that this system permits the utilization
1 of a maximum amount of space within the truck body. This is
contrary to endless conveyor systems of the prior art wherein a
large amount of wasted space had to be allowed at each end of the
trailer to permit the containers to make the turns.
The transverse drive means generally indicated by the
numeral 16 in Figure 1 includes a fluid actuated cylinder 24
which is double-acting and which includes a piston rod 26 on one
end and a piston rod 28 on the other. The stroke length of the
piston is generally`equal to the width of a tray 22 which is the
distance required to move the tray from one space to another.
A cable 30 is attached at one end to the end of piston rod 26 and
extends around guide pulley 32 which is mounted on the floor of
the vehicle for rotation about a vertical axis and then around
pulleys 34, 36, 38, 40 and 42 whereupon the other end of the
cable is connected to the end of piston rod 28. Drive detents
44 and 46 to be described in greater detail below are connected
to the cable at 48 and 50 respectively on what are~referred to
as the transverse runs-of the cable 30. It can be seen that
when the cylinder 24 is actuated so that the piston rod 26
is retracted and the rod 28 is extended, the cable 30 is pulled
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to the left by the piston rod 26 causing the drive detents 44
and 46 to move to their respective dotted line positions as
shown in Figure 1. When the cylinder is again actuated to
extend the piston 26 and retract the piston rod 28, the drive
detents are moved back to their full line positions as shown in
Figure 1.
The longitudinal drive means 14 includes a fluid-
actuated cylinder 56 having piston rods 58 and 60. A cable 62
extends from piston rod 58 around guide pulleys 64, 66, 68, 70,
1~ 72, and 74 and is attached at its other end to the end of piston
rod 60. Drive detents 76 and 78 are attached to the cable at
80 and 82 respectively along what will be referred to as the
longitudinal runs of the cable 62. When the cylinder 56
is actuated to retract the piston rod 58 and extend the rod 60,
the cable 62 will be pulled to the left as viewed in Figure
1 whereupon drive detent 76 will be pulled to the right to the
dotted line position. Likewise drive detent 78 will be pulled
to the right to its dotted line position. It is to be under-
stood that the drive detents engage trays which occupy the
spaces diagrammatically illustrated in Figure 1, with the
exception o~ one space which is left blank.
As shown in Figure ~, a plurality of casters, all
indicated by the same number 8~, are mounted on the floor
12 of the vehicle 10 for swivel motion as is conventional
with casters. Figure ~ is illustrative of a floor arrangement
suitable for supporting trays 22 for movement over the floor. This
arrangement is suitable for the embodiment of Figure 1 and the
embodiments to be disclosed later herein with only slight modifica-
tions necessary to accommodate the different positions of the
conveyor hardware.
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In Figure 12 it can be seen that strings of rollers 13
underlie the longitudinal rows of conveyors with preferably three
strings of rollers for each row. Of course, sufficient space is
left for the trackways which receive the drive detents. Braking
members or static rests 15 are spaced stragetically on the floor
of the vehicle, preferably at the ends thereof. These rests
comprise a supporting base and are covered on the top with a
friction-reducing material such as nylon or the like. The top
surfaces of the members are substantially level with the surface
of the rollers of the roller strings 13 and the casters 84. The
purpose of these braking members is to provide a more stable
support when the loads are in transit. The loads which are
supported entirely on the rollers or casters would not be very
stable. The front end of the vehicle in the area of transverse
movement is provided solely with the braking member type of
supports while on the rear end of the vehicle a combination of
braking support members 15 and the casters 84 is used. To
further assist in stabilizing the load, toggle throw type of load-
bracking devices 17 are provided at the rear ends of the longi-
tudinal rows. When unloading, rollerways 19 are provided at the
rear of one row of loads to facilitate removal of loads from the
vehicle and onto a loading dock, or at least onto a position where
it can be reached by a forklift truck. The area 21 is the
operator's area and includes a control panel 23 and operator
protecting stanchions 25.
Tray 22 is substantially a planar metal sheet of
sufficient strength to support palletized loads and is provided
with slots 86 along each side edge portion thereof. These slots
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receive the drive detents as will be explained more fully below.
Figure 2 further shows in greater detail the cable arrangement
at the changeover section between the transverse drive means and
the longitudinal drive means. Figure 2 also more clearly shows
the trackway 45 which receives the transverse drive detent 44 and
the trackway 77 which receives the longitudinal drive detent 76.
It is to be understood that all of the drive detents and trackways
are substantially identical. Figure 2 also shows detent devices
90 which hold trays in the space A7. The detents permit movement
of the trays into space A7 from space B7 but prevent the trays
from moving back into space B7, though it does not prevent the
trays from moving from A7 to A6. In other words, the detents are
arranged for counterclockwise movement of the trays through the
rectangular path defined by the two rows of trays.
Figure 3 further illustrates guide rail 100 which ex-
tends down the center of the vehicle and which is provided with
outwardly extending flange 102 which keep the trays from rising
up. Likewise a similar flange 104 is mounted along each side
wall of the vehicle. Again, the purpose is to again keep the
trays in position on the rollers or casters to prevent them from
rising upwardly.
One of the drive detents is shown in greater detail
in Figures 4 through 6. Detent 76 will be described, however,
it is to be understood that the other drive detents 44, 46 and
78 are identical. The detent includes a floor portion 108 which
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terminates in underlying flanges 75 which are received in the
channels defined by the overlying flanges 79 on the trackway
77- The drive detent will be referred to as havi.ng a front
end 110 and a rear end 112. The side walls 114 extend the
length of the detent and at the rear end portion thereof an
axle 116 extends between the two walls. The axle swingably
supports the detent element 118, the upper portion of which
is the part that is actually received in the slots 86 in the
trays when the drive detent is in driving position. A pair of
~0 stops 120 are mounted on the floor of the detent and prevent the
detent element 118 from swinging in the counterclockwise
direction from the position shown in Figures 4 and 5. A tension
spring 122 is connected at one end to the floor 108 and at the
other end to the lower end of the drive detent 118 to maintain
it in the position shown in Figures 4 and 5, up against the
stops 120. lt can be seen that when the element 118 is engaged
in one of the slots 86 of the tray and the drive detent is
moved to the right as viewed in the figures, the element 118,
¦because of its inability to swing in a counterclockwise direction
¦about the axle 116, will pull the tray to the right. However,
when the drive detent is moved to the left, the element 118 can
pivot in the clockwise direction against the bias of the spring
122 whereupon the element 118 is released from the slot 86 of
one of the trays and permits the detent to move under and into
driving engagement with an adjacent tray. .
Referring again to Figure 1, it is to be understood
that the embodiment shown therein utilizes a single blank
space to move the loads in a rectangular path through the two
ows Al to ~7 and ~1 to ~7. In operation, assuming that space
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A7 is vacant, transverse drive means 16 is actuated to retract
p;~t~ fod
o~m~er 26 whereupon the detent 44 which is in driving ellgage-
ment with the tray occupying the space B7 is moved to the dotted
line position to move the tray in B7 to A7. At the same time,
the detent 46 which had been in engagement with the tray
occupying space Bl is released and moved back to the dotted line
position and into engagement with one of the drive slots of the
tray occupyin~ space Al. In the second step of the cycle,
longitudinal drive means are actuated whereupon piston rod
58 is retracted and cable 62 is pulled to the left thereby pulling
detent 78 which is in driving engagement with the tray occupying
space Bl to the dotted line position. The trays occupying
sPaces B2 through B6 are pushed bv the trav occ~pvina sp~ce
Bl one tray length such that the trays will occupy positions
B2 through B7. At the same time, drive detent 80 will be
released from the tray in space A6 and will be moved bac]~ to the
position underlying and in driving engagement with the tray
occupying space A7. The transverse drive means 24 is actuated
to move the tray in Al to the now vacated space in Bl, following
which the longitudinal drive means is again actuated to move the
trays occupying spaces A2 through A7 to the spaces Al through
~6. Space A7 is now vacant and one cycle has been completed.
The successive actuations of the transverse and longitudinal drive
~
means is continued until a selected load appears at the rear of
the vehicle whereupon it can be readily unloaded.
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The longitudinal rows are preferably offset, as
shown in Figures 12 and 13 such that a load being shifted
transversely from one row to the next will not snag a load
in the next row. This offset is accomplished by only slightly
lengthening the stroke of the longitudinal drive pistons.
The stroke length will be equal to a load length plus the
offset. When a load is engaged, for longitudinal movement
it will first cover the distance of the offset space and will
then cover one load length to move the entire row one load
length.
Figures 7 through 11 schematically illustrate
different arrangements of the cable-driven detents utilizing
either the single blank space or double blank space concepts,
and in the instance of the arrangements shown in Figures 9
and 10, utilizing additional fluid power cy'inders and in some
instances utilizing drive detents which are directly connected
to the piston rods of some of the fluid power cylinders.
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~ Figure 7 is the mirror image of the arrangement shown
; in Figure 1 and the only difference in the arrangement shown in
- Figure 1 and that of Figure 7 is that in Figure 1 the loads are
moved in a counterclockwise direction while in Figure 7, the
loads are moved in a clockwise direction.
In the arrangement shown in Figure 8, the fluid power
cylinder A drives the longitudinal detent 76 and the transverse
detent 46 while the cylinder B drives the longitudinal detent
78 and the transverse detent 44. In the case of rectangular
0 trays wherein the length is greater than the width, a lost motion
connection has to be provided between the cables and the trans-
verse detents 44 and 46 since the stroke length for the cylinders
A and B will be the same for a transverse or a longitudinal
movement. The arrangement shown in Figure 8 utilizes a single
blank space as with the arrangements of Figures 1 and 7 and move
the loads in the clockwise direction. Of course, it is to be
understood that for all arrangements shown, the direction of
movement is dependent upon the positioning of the drive detents
and the arrangement of the cables over the Eloor of the vehicle.
In Figure 9 a still further simplified system is shown
wherein four power cylinders 200, 201, 202 and 203 are placed on
the vehicle floor, with cylinders 201 and 203 effecting longitu-
dinal movement of the trays while cylinders 200 and 202 effect
the transverse movements. The detents 204, 206, 208, and 210
are identical to that described with the earlier described
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embodiments; however, they are connected directly to the piston
rods of the cylinders 200 - ~03. As shown, the cylinders are
designed for counterclockwise movement of the load through the
rectangular path. However, it is to be understood, as with all
the other embodiments, the direction of the cylinders may be
merely reversed whereupon clockwise rotation can be effected.
In any event, assuming that the space in the upper righthand
corner is vacant, cylinder 202 is extended and then retracted
to draw the load in the adjacent space transversely and into the
vacant upper righthand corner space whereupon cylinder 201 is
actuated to move its row of trays to the right and into the newly
vacated space. Transverse drive cylinder 200 is then activated,
following which the longitudinal cylinder 203 is activated. After
this sequence of movements, the space in the upper righthand
corner is again vacant. This describes the operation wherein
a single blank space was utilized. Assuming that double blank
spaces are utilized and the system shown in Figure 9 is operable
with double blank spaces, then the time consumed in moving a
load throughout the entire rectangular path is cut in half. For
example, assuming that the space in the uppcr righthand corner and
the space in the lower left hand corner are vacant, then,
transverse cylinders 200 and 202 may be operated simultaneously
to move loads from adjacent rows into those vacant spaces,
following which hydraulic cylinders 201 and 203 are simultaneously
actuated to move the two rows longitudinally in opposite directionc ,.
In Figure 10 an arrangement is shown for moving loads in
the clockwise direction utilizing either a single blank space
or double blank spaces. Again, it is to be understood that by
ilizing the mirror image arrangement of the arrangement shown
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lOS907Z
in Figure 10, the directlon of movement of the load can be
reversed~ In any event, a pair of cylinders 220 and 222 are
utilized to effect movement of.one transverse detent 224
¦through connecting cable 234 while cylinders 226 and 228 effect
movement of the other transverse detent 230 through connecting
cable 232. By using pairs of cylinders in this manner, the
detents 224 and 230 may be operated simultaneously to move loads
from adjacent rows to adjacent blank spaces ~7here the double
blank space concept is used. The longitudinal movements are
\~ effected by cylinders 240 and 242 which have directly connected
thereto longitudinal drive detents 244 and 246. By simultaneous
actuation of the cylinders 240 and 242, the trays or loads in
the two rows may be moved simultaneously in opposite directions.
Of course, by energizing the drive means one at a time, the
arrangement of Figure 10 can be used to move loads through the
rectangular path utilizing only a sinyle blanl; space.
Finally, in Figure 11 an arrangement is disclosed which
is used to move a load through a path in the clockwise direction
utilizing double blank spaces. Cylinder 300 when actuated, causes
~0 longitudinal driving movement of longitudinal drive detents 302
and 304 through cable 306. Transverse drive cylinder 308
simultaneously effects transverse driving movement of transverse
detents 310 and 312 by means of cable 314.
It can be seen that the cable, drive detent arrangement
disclosed by applicant is highly versatile and may be readily
adapted to existing vehicles without significant structural
modification. Further, by varying the disposition of the cables,
detents and power cylinders on the floor of the vehicle, the
lOS~072
direction of movement of the loads can be varied. Further, by
making other modifications previously described, a double blank
space concept may be utilized whereby loads are moved through
the rectangular path in half the time required when only a single
blank space is employed. F'inally, a savings in power is realized
in a number of the embodiments disclosed herein, particularly
those described in Figures 1, 8 and 11, wherein only a pair of
hydraulic cylinders are required to effect the two transverse
movements and the two longitudinal movements.
~D Figures 14 and 15 diagrammatically illustrate a system
whereby a vehicle load may be exchanged with a load in another
vehicle or in a stationary housing or unit on a loading dock. The
system employs the indexing arrangement described with respect to
the aforegoing embodiments wherein loads are indexed in a
rectangular path using at least a single void area on the floor
of the vehicle. In the Figures, the number 400 indicates a
trailer loaded with a plurality of unitized containers or
palletized loads 402. The loads are aligned in two longitudinal
rows on conveyors which are designed to index the loads in a
rectangular path through the two rows. The embodiments described
earlier herein can be used in thls system or the embodiments
disclosed in applicant's earlier patents may be used. A
stationary unit 404 can be mounted on a loading dock or is mounted
on hydraulically adjustable supports 406 by which the stationary
unit 404 can be adjusted to the height of the vehicle or trailer
400. The loads in the stationary unit 404 are identified by
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the numeral 402a. The stationary uni t 404 is likcwise provided
with a conveyor mcchanism which will index the loads through an
endless rectanyular path within the confines of the unit. Further,
the trailer and the stationary unit 404 are provided with
closures which may be locked for security purposes. It is to
be understood that the stationary unit 404 may be replaced by
another trailer or the like.
The purpose of this arrangement is to exchange the load
of the trailer 400 with the load of the unit 404. This is
accomplished by deactivating the transverse conveying units at the
adjacent ends of the units 400 and 404. For example, in the
embodiment of Figure 1 of this application, the drive detent may
be held by any suitable mechanical means in the downward, out-of-
engagement position such that even though it is actuated and
goes through the motions, it will not engage the trays. A
spanning or connecting conveyor such as a roller conveyor or the
like 408 ls positioned between the floors of the trailer 400
and the stationary unit 404. In Figure 14, the connecting convey-
or 408 is exaggerated, however, it is to be understood that it is
of a height which is substantially equal to the height of the
supporting rollers or casters which support the loads 402 or 402a.
Since the transverse movements at the adjacent ends of the units
(which movements are indicated by the dotted-line arrows X and
Y) have been eliminated, upon actuation of the system, the units
will travel in an enlarged rectangular path which covers the two
units. Accordingly, the loads are indexed within the longitudinal
rows and within the units until they are completely exchanged.
In Figure 15, the exchange process is indicated as being in
process.
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In practical application, a supermarket or the like
may employ one of the stationary units on one of its loading
docks and perhaps may fill it with empties to be returned.
supply truck may arrive at any time during the night or day.
The driver can unlock the unit 404 and by actuatlng the conveyors
in each, can fully exchange the loads, can lock up the unit 404,
and then dxive off. There is no need for an attendant to be
present and when the store manager arrives in the morning he
will find a complete new stock. It is contemplated that the
power units for the conveyor systems for each of the units can
be connected in tandem such that one will be a slave to the
other.
In a general manner, while there has been disclosed
effective and efficient embodiments of the invention, it should
be well understood that the invention is not limited to such
embodiments as there might be changes made in the arrangement,
disposition, and form of the parts without departing from the
principle of the present invention as comprehended within the
scope of the accompanying claims.
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