Transport apparatus for vertically moving objects and method

A Transport apparatus includes a vertically extending frame, three plate assemblies mounted on the frame and three assembly drives connected to the plate assemblies for vertically moving the plate assemblies in the frame. The frame surrounds a transport column which includes a bottom work position, a middle storage position and a top storage position. Each plate assembly includes a carriage adjacent a side of the frame, a rectangular plate, a hinge between the carriage and plate and a pair of hinge drives for rotating the plate between a horizontal load supporting position in the transport column and a vertical position adjacent the column. The assemblies are lowered to the under position with horizontal plates supporting pallets filled with work parts. After the work parts and pallets are removed, the plates are rotated to the vertical and moved up to storage positions.

FIELD OF THE INVENTION 
The Invention relates to transport apparatus for repetitively moving 
objects between a number of vertically spaced transport positions. The 
invention is used on assembly lines to keep assembly line workers stocked 
with the necessary work parts which are attached to assemblies moving 
along the line. 
DESCRIPTION OF THE PRIOR ART 
Parts are conventionally supplied to assembly line workers on pallets which 
are stored in two level and three-level pallet racks located on one side 
of the line adjacent a work station. These racks are relatively narrow, 
given the close spacing of work stations along the line. The worker picks 
parts from the pallet at the bottom of the rack and places the parts on 
assemblies moving along the line. Pallets loaded with parts are placed on 
the rack at the upper two levels in order to assure that a supply of parts 
is maintained adjacent the work station for transfer to the lower level 
when parts are exhausted from the pallet at the lower level. 
Loaded pallets on the racks are moved to different positions in the rack 
using a fork lift truck which is driven along a roadway extending along 
the side of the racks away from the assembly line. The fork lift trucks 
load filled pallets in the upper two levels on the rack and, in response 
to requests from workers, remove empty pallets from the bottom level of 
the rack and then pick up a full pallet from one of the upper levels and 
move the pallet to the bottom level. It is essential that these operations 
be performed promptly in order to assure that the workers always have a 
supply of parts. If a work station runs out of parts the assembly line 
must be shut down until parts are resupplied to the station. 
The worker is unable to transfer a loaded pallet on the rack to the bottom 
station but must await the arrival of a fork lift truck to perform this 
operation. There can be a considerable delay between the time a worker 
signals that the pallet at the lower work level is empty and an available 
lift truck can be driven to the opposite side of the rack for removal of 
the empty pallet and movement of a loaded pallet at an upper level down to 
the lower level. 
The job of supplying work parts to assembly line workers is further 
complicated because the number of parts carried by a single pallet may 
vary depending upon the size or weight of the part. This means that there 
is a greater call for fork lift trucks to service the work stations with 
pallets carrying a small number of parts than there is for work stations 
with pallets carrying a larger number of parts. 
The problem of supplying work parts to assembly line work stations is 
further complicated because the work stations are closely spaced together 
along the length of the line. Parts must be stored above the lower level 
in pallet racks because there is no available space to either side of the 
work station. 
All of these factors complicate the supply of pallets with work parts to 
assembly line workers, particularly in assembly lines where the delay or 
misplacement of a single pallet of critical parts could delay or stop 
production on the entire line. Shutdown of an assembly line of this type 
because of a lack of work parts is very expensive. 
SUMMARY OF THE INVENTION 
The invention is a transport apparatus useful on an assembly line for 
on-demand delivery of loaded pallets to a bottom work position. The 
apparatus includes a vertically extending frame, a transport column in the 
frame, a number of vertically movable plate assemblies mounted on the 
frame and a number of assembly drives connected to the plate assemblies 
for moving the assemblies up and down the frame. 
The frame has an operator side with a work part discharge opening that 
provides worker access to work parts on a pallet at the bottom work 
position and an opposed loading side that provides fork lift truck access 
to the bottom work position and to two elevated storage positions. 
The plate assemblies each include a carriage mounted on the frame, a pallet 
support plate, a hinge connection between the carriage and the support 
plate and a hinge drive. The hinge drive rotates the plate from a 
horizontal load-supporting position in the transport column to a retracted 
vertical position outside the column close to the frame. The assembly 
drive lowers plate assemblies with horizontal plates carrying loaded 
pallets down to the bottom work position to supply parts to an assembly 
line worker on demand. 
When all the work parts have been removed from the pallet at the work 
position, the worker pushes the empty pallet from the work position and 
actuates the transport apparatus to automatically rotate the empty lower 
plate to a vertical position at one side of the column and then lower an 
elevated plate assembly carrying a loaded pallet down the column, past the 
vertical plate and to the work position to resupply parts to the lower or 
bottom position. The plate assembly with the vertical plate is raised past 
the new assembly at the lower position to an elevated position and the 
vertical plate is then returned to the horizontal to receive a loaded 
pallet from a supply fork lift truck. 
The transport apparatus moves loaded pallets from an elevated storage 
position down to the bottom work position upon worker demand. Loaded 
pallets are transfered to the work position automatically and rapidly. 
There is no need to position a fork lift truck at the back of the frame, 
lift a loaded pallet from an upper storage position, withdraw the lifted 
pallet from the frame, lower the pallet on the truck to the bottom 
position and then move the pallet into the frame and place the pallet in 
the lower position. On-demand delivery of loaded pallets to the work 
position reduces assembly line downtime due to a lack of parts. 
The transport apparatus is compact with all plate assemblies and associated 
drives located within the space occupied by a conventional three level or 
tier pallet frame. The compact design is important because there is very 
limited space available for pallet storage to one side of a production 
line. 
Other objects and features of the invention will become apparent as the 
description proceeds, especially when taken in conjunction with the 
accompanying drawings illustrating the invention, of which there are 
sixteen sheets and one embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
As illustrated in FIGS. 1 and 2, transport apparatus 10 includes a 
rectangular vertically extending frame 12, three plate assemblies 14, 16 
and 18 mounted on the frame 12 and three assembly drives 20, 22 and 24 
connected respectively to assemblies 14, 16 and 18 for moving the plate 
assemblies vertically along frame 12. 
Frame 12 includes a right side 26, a left side 28, an operator side 30 and 
a loading side 32 each extending from frame base 34 to top 36. Frame 12 
surrounds and defines vertical transport column 38. Transport column 38 
includes a bottom work position 40 adjacent base 34, a middle storage 
position 42 spaced above bottom work position 40 and a top storage 
position 44 spaced above middle storage position 42 and below top 36. 
Like assembly drives 20 and 22 move like plate assemblies 14 and 16 up and 
down along transport column 38 between bottom work position 40, middle 
storage position 42 and top storage position 44. Assembly drive 24 moves 
plate assembly 18 up and down between bottom work position 40 and middle 
storage position 42. 
Frame 12 includes four elongate corner posts 46 extending from base 34 to 
top 36, a number of cross members 47 between the posts, and three pairs of 
opposed vertical U-channels 48, 50 and 52 at the edges of right side 26, 
left side 28 and operator side 30, respectively. Each U-channel is joined 
to and extends the full height of frame 12 along one of posts 46. 
As shown in FIGS. 3-5, plate assembly 14 includes a vertically moveable 
carriage 56 extending across side 26 between adjacent pair of U-channels 
48, a rectangular plate 58, a horizontal hinge 60 joining plate 58 to 
carriage 56 and a pair of fluid cylinder hinge drives 62 and 64 mounted on 
carriage 56 and operable to rotate plate 58 between a horizontal load 
supporting position in column 38 and a vertical position adjacent the 
frame and to one side of the column. 
Two spaced carriage wheels 66, 68 and 70, 72 are mounted on each opposed 
end of carriage 56. The wheels run in U-channels 48 to facilitate vertical 
movement of carriage 56 on the frame. The axis of hinge 60 extends 
horizontally across the right side 26 of frame 12 and along the carriage 
56, to one side of transport column 38. Cylinder drives 62 and 64 connect 
the plate and carriage a distance outwardly from the hinge to rotate the 
plate relative to the carriage as described. The drives 62 and 64 are 
located at the ends of the hinge 60 and do not obstruct the load 
supporting surface of the plate 58 in column 38. Stops on the carriage 56 
support the plate when in the horizontal position. When the plate is in 
the vertical position, the assembly drive 20 may move plate assembly 14 
vertically past the other plate assemblies 16 and 18. Pairs of spaced 
guide rails 74 are mounted on frame 12 right and left sides 26 and 28 and 
extend vertically from the base 34 to top 36 of the frame. 
Assembly drive 20 includes a hydraulic cylinder 76 having a body mounted on 
the base 34 between guide rails 74 and a piston rod 78 extending 
vertically from the body to a lift head 80 on the end of the rod. A pair 
of idler sprocket gears 82 are mounted on head 80. Assembly drive 20 also 
includes two like lift chains 84. One end of each chain is secured to a 
cross member 47 at bottom of the frame. The chains extend up from the 
cross member, are wrapped around gears 82 on head 80 and extend down from 
the gears to second ends secured to carriage 56 of plate assembly 14. 
Extension and retraction of cylinder 76 moves assembly 14 between the 
bottom, middle and top positions in column 38. Pairs of guide wheels 86 
and 88 on head 80 are located to either side of rails 74 and hold the head 
in place between the rails during raising and lowering of assembly 14. 
Assembly drive 20 is located entirely within the frame 12. The drive 
rapidly raises and lowers plate assembly 14 at twice the extension and 
retraction speed of cylinder 76. 
Assembly drive 22 for plate assembly 16 is identical to assembly drive 20 
and need not be further described. 
As shown in FIGS. 3-5, hinge 60 includes a number of plate ribs 90, 92, 94, 
96, 98 and 100 mounted on the bottom of plate 58, a number of carriage 
ribs 102 mounted on carriage 56 and a hinge pin 104 extending through 
bores in the free ends of the ribs. Hinge drive cylinders 62 and 64 are 
connected between the carriage 58 and the free ends of plate ribs 98 and 
100 so that extension of the cylinders raises the plate from the 
horizontal position to the vertical position. 
Plate assembly 16 is identical to plate assembly 14 and includes a 
vertically moveable carriage 106, a rectangular plate 108, a hinge 110 
joining plate 108 to carriage 106 and a pair of hinge drives 112 and 114 
mounted on carriage 106 and operable to rotate plate 108 like the 
corresponding members of plate assembly 14 and need not be described 
further. 
As shown in FIGS. 6-10, plate assembly 18 differs from plate assemblies 14 
and 16 and includes a vertically moveable rectangular carriage 116 
defining a rectangular opening 134, a rectangular support plate 118, a 
hinge 120 joining plate 118 to the bottom bar of the carriage 116 and a 
pair of cylinder hinge drives 122 and 124 mounted on carriage 116 and 
operable to rotate plate 118. 
Carriage 116 includes bottom bar 126, top bar 128 and side bars 130 and 132 
joining the ends of bottom bar 126 and top bar 128 to form a hollow 
rectangular frame surrounding the rectangular work part discharge opening 
134. Opening 134 extends across the width of operator side 30 of the frame 
and vertically a distance equal to the distance between the bottom work 
position 40 and the middle storage position 42. The hollow rectangular 
frame provides operator access through opening 134 to plate 118 when the 
carriage 116 is in the bottom work position 40. 
Three spaced carriage wheels 136, 138, 140 and 142, 144, 146 are mounted on 
each opposed ends of carriage 116 and run in U-channels 52 to facilitate 
vertical movement of carriage 116 on the frame 12. 
Assembly drive 24 raises and lowers the assembly 18 between the work and 
middle positions only. A pair of opposed vertical guide rails 148 on frame 
12 extend from a point on the frame 12 adjacent middle storage position 42 
to top 36 along operator side 30. The drive 24 includes a hydraulic 
cylinder 150 having a body mounted on a frame cross member 47 at middle 
position 42 between rails 148 and a piston rod 152 extending vertically 
from the body to a lift head 154 on the end of the rod 152. Two pairs of 
drive wheels 156 and 158 mounted on opposed ends of lift head 154. Each 
pair 156 and 158 engaging one of rails 148 for guiding vertical movement 
of cylinder 150 between rails 148. A pair of idler sprocket gears 160 are 
mounted on head 154 and a pair of chains 162 secured to the cross member 
47, wrapped around gears 160 and secured to carriage top bar 126. 
Extension and retraction of the cylinder 150 raises and lowers the 
assembly 18 between bottom position 40 and middle position 42. Drive 24 is 
located entirely within frame 12 and does not obstruct workers access to 
the bottom work positions. 
As shown in FIGS. 6-10, hinge 120 includes a number of long plate ribs 164 
and short plate ribs 166 mounted on the bottom of plate 118, a number of 
carriage ribs 168 mounted on carriage 116, two drive ribs 170 and 172, and 
a hinge pin 174 extending through bores in the free ends of the ribs. 
Hinge drive cylinders 122 and 124 are connected between the carriage 116 
and the free ends of drive ribs 170 and 172 so that extension of the 
cylinders raises the plate from the horizontal position to the vertical 
position to one side of column 35. Stops hold the plate in the horizontal 
position. 
The axies of the plate hinges are located outside of the transport column 
38 and inside the frame sides to permit upward rotation of the plates from 
the horizontal load-carrying position to the vertical position located 
outside of the column and inside the adjacent frame side. When in the 
horizontal position, the plates extend across the transport column with 
the plate edges away from the hinges defining the sides of the column. 
Transport apparatus 10 includes a control system (not illustrated) for 
operating the apparatus in response to operator input. The control system 
extends and contracts the disclosed power cylinders to cycle the apparatus 
as described below. 
The cycle of operation of transport apparatus 10 will now be described with 
reference to FIGS. 14A and B through 25A and B. The paired views of these 
figures show operation of the apparatus 10 from the operator side 30 in 
the A figure and from the right side 26 in the B figure. 
As shown in FIGS. 14A and B, apparatus 10 begins operation with the plates 
of assemblies 16, 18 and 14 extending into transport column 38 in bottom 
work position 40, middle storage position 42 and top storage position 44, 
respectively. Each plate assembly 14, 16 and 18 supports a filled work 
material pallet (not illustrated). 
A worker, standing adjacent operator side 30, reaches into frame 12 through 
the access opening between bottom work position 40 and middle storage 
position 42 and removes the work parts from the pallet on plate assembly 
16. When all the work parts have been removed from the pallet, the worker 
pushes the pallet out from frame 12 through loading side 32 and activates 
the drive control for apparatus 10. 
As shown in FIGS. 15A and B, the empty plate of plate assembly 16 is 
rotated out of transport column 38 by hinge drives 112 and 114 to the 
retracted vertical position parallel left side 28 and outside column 38. 
As shown in FIGS. 16A and B, plate assembly 14 is then moved by assembly 
drive 20 from top storage position 44 to middle storage position 42 and 
simultaneously plate assembly 18 is moved by assembly drive 24 from middle 
storage position 42 to bottom work position 40, thereby resupplying work 
parts to the work positions. 
As shown in FIGS. 17A and B, plate assembly 16 is next moved by assembly 
drive 22 from bottom work position 40 to top storage position 44 and the 
plate is rotated back to the horizontal in the transport column 38 by 
hinge drives 112 and 114. A fork lift truck then places a filled pallet on 
assembly 16. 
The worker again reaches into frame 12 through the access opening between 
bottom work position 40 and middle storage position 42 and opening 134 and 
removes the work parts from plate assembly 18. When all the work parts 
have been removed from the pallet on plate assembly 18, the worker pushes 
the pallet off plate assembly 18 and out of frame 12 as before and again 
activates the drive control. 
As shown in FIGS. 18A and B, the empty plate of plate assembly 18 is then 
rotated out of transport column 38 by hinge drives 122 and 124 to the 
retraced vertical position parallel operator side 30. 
As shown in FIGS. 19A and B, plate assembly 16 is moved down from the top 
storage position 44 to the middle position 42 and plate assembly 14 is 
simultaneously moved from middle storage position 42 to bottom work 
position 40 to resupply work parts to the bottom position. 
As shown in FIGS. 20A and B, plate assembly 18 is then moved by assembly 
drive 24 from bottom work position 40 to middle storage position 42 and is 
held with the plate in the vertical position. 
The worker again reaches into frame 12 through the access opening between 
bottom work position 40 and middle storage position 42 and removes the 
work parts from plate assembly 14. When all the work parts are removed 
from plate assembly 14, the worker pushes the pallet off plate assembly 14 
out of frame 12 through loading side 32 and again activates the drive 
control. 
As shown in FIGS. 21A and B, the assembly 14 plate is then rotated out of 
transport column 38 by hinge drives 62 and 64 to the retraced vertical 
position parallel to right side 26. As shown in FIGS. 22A and B, plate 
assembly 16 is then moved by assembly drive 22 from middle storage 
position 42 to bottom work position 40 to resupply work parts to the 
bottom position. 
As shown in FIGS. 23A and B, plate assembly 18 is then rotated into 
transport column 38 at the middle work position 42. 
As shown in FIGS. 24A and B, plate assembly 14 is then moved by assembly 
drive 20 from bottom work position 40 to top storage position 44 and 
rotated into transport column 38 by hinge drives 62 and 64. 
As shown in FIGS. 25A and B, this completes one cycle of operation and 
plate assemblies 14, 16 and 18 are in there original starting position. 
After a plate assembly has been moved from the bottom work position 40 to a 
storage position 44 or 42 and rotated back into transport column 38, the 
plate assembly is loaded with work material by a forklift from the loading 
side. 
All the plate assemblies move down column 38 to the bottom position with 
horizontal plates supporting filled pallets. After the pallets are emptied 
at the bottom position, the plates are rotated to the vertical outside the 
column and moved up to elevated positions to receive filled pallets. 
Assembly 14 and 16 move between all three bottom, middle and top 
positions. Assembly 18 moves between the bottom and middle positions only. 
Apparatus 10 has been described has having a work position and two elevated 
storage positions. The invention includes transport apparatus with a 
single storage position for feeding pallets or work to the work position. 
Additionally, if desired, the apparatus may have more than two storage 
positions and additional plate assemblies for these positions. 
The disclosed work position is located at the bottom of the frame. It is 
contemplated that the work position may be located at the top of the frame 
or even in the middle of the frame. In the former case pallets would be 
conveyed up the frame from a storage position to the work position for 
unloading. In the latter case, pallets would be conveyed up to the work 
position from one or more storage positions located below the work 
position and pallets would be conveyed down to the work position from one 
or more storage positions located above the work position. 
While I have illustrated and described a preferred embodiment of my 
invention, it is understood that this is capable of modification, and I 
therefore do not wish to be limited to the precise details set forth, but 
desire to avail myself of such changes and alterations as fall within the 
purview of the following claims.