US1980850A

US1980850A - Storage apparatus

Info

Publication number: US1980850A
Application number: US494438A
Authority: US
Inventors: Malcolm S Clark
Original assignee: Individual
Current assignee: Harnischfeger Corp
Priority date: 1930-11-08
Filing date: 1930-11-08
Publication date: 1934-11-13
Anticipated expiration: 1951-11-13

Description

NOV. 13, 1934. 7' M CLARK 1,980,850

STORAGE APPARATUS Original Filed May 14, 19:28 3 Sheets-Sheet l wuentoz No v. 13, 1934 I Q M, CLARK 1,980,850

STORAGE APPARATUS Original Filed May 14, 1928 3 Sheets-Sheet 2 Nov. 13, 1934. M s, CLARK 1,980,850

STORAGE APPARATUS Original Filed May 14, 1928 3 Sheets-Sheet 3 Patented Nov. 13, 1934.

was

UNITED STATES PATENT OFFICE STORAGE APPARATUS Edwin A. Roehling Continuation of application Serial No; 277,584, May 14, 1928. This application November 8, 1930, Serial No. 494,438

21 Claims.

This invention relates to apparatus for the stor age and movement of merchandise, and more particularly to the storing of bulky'articles in large warehouses, such as automobiles and other vehicles in garages.

The present application is a continuation of and a substitute for my application for storage apparatus, filed Mayl4, 1928, Serial No. 277,584. The primary object of the present invention is the conservation and utilization of space within the storage building and the making of every stored article readily accessible and available for removal within a minimum time. A further object is toreduce cost of operation and expense of installation by arranging storage units in vertically parallel columns with the weight of one column counterbalancing the weight of the other column, thereby reducing to a minimum the power required for moving the columns, and also to provide for quick exchange of units from one column to the other so that any unit in either column may be brought to a particular location for the loading or unloading of the unit. It is also an object to provide a construction and arrangement whereby the vertical column'of units are self supporting, thus relieving the building to a large degree from the load'and permitting the use of a more cheaply constructedbuilding.

It is also an object to provide certain other new and useful features, all as hereinafter more fully set forth.

forth and more particularly pointed out in the appended claims reference being had to the accompanying drawings, in which:

of Figure 1 with the upper end of the machine shown in plan View;

Figure 4 is a vertical section substantially upon,

the line 4-4 of Figure 1, but showing the cages or compartments in end elevation; and

Figure 5 is a diagrammatic view of the two machines illustrative of the manner of installing and operating the same. I

The present machine is particularly designed for the storage of automobiles but it will be obvious that a machine may be built to operate upon the same principle, for the storage of commodities other than motor vehicles and may be designed to suit the particular class of goods, articles or merchandise to be handled and stored thereby and to adapt it to the particular place of installation.

However, for the purpose of the present illustration, the machine is shown as installed in a garage building and is designed to handle automobiles, it being supported upon the building foundation or upon a foundation located at the basement floor of the building, to extend vertically upward to any desired height within the building, and it will be understood that while a single machine comprising two vertical columns or stacks of storage units is shown, this machine may be duplicated any desired number of times within a single building, as indicated diagrammatically in Figure 5. I

.The'machine as illustrated comprises two parallel vertical columns or stacks of storage units,

cages or compartments, which for convenience of J description are indicated as a whole by the numerals 1 and2 although these storage units are nearly identical in structure, each comprising a framework of sufficient strength and rigidity and of any suitable construction, to support the weight of the several superposed units in each vertical 3

column

3 and 4 of these units. Each storage unit Figure l is a slde elevation of a devlce or mais of such dimensions that a motor vehicle may be run directly into the same, each unit forming a cage or box-like structure for housing the automobile and if found desirable the framework of each of these units may be covered with sheet metal to form a tight enclosure and provided with tightly closing end doors, not shown in the drawings.

ly upon the other, the lower unit of the column supporting the entire weight of the units above and the lower unit is supported in a manner hereinafter described upon any suitable foundation These several storage units in cache column are designed to normally rest one direct- 1y to one end of the rack bar.

which may be located at the level of the basement floor and therefore the weight of each column of units is supported upon a foundation independent of the building structure, which structure may therefore be of comparatively light and cheap construction. Preferably, the building would be formed with a well or wells extending from basement to the desired height in the 1 building and within which the vertical columns of units are placed, the walls 5 of the building forming the walls of this well and between the floors 6 entrance and exit openings into the well may be provided and these entrances and exits may all be at the same floor level or may be located at different levels as desired so that the automobile may be driven directly into one of the storage units and then by transferring this unit from one column to the other as hereinafter described, the automobile may be driven directly out through the exit from the storage unit after said unit is brought to the level of the exit.

To lift one column of storage units vertically and at the same time lower the units in the other column, pairs of vertical rack bars '7 are guided in suitable guides 8, there being a pair of rack bars 7 at each side of the lower storage unit of each column. In addition to the rack bars '7, a similar pair of rack bars 9 is provided at each side of the lower unit of each column, these latter bars being guided in suitable guides extending parallel with and'being similar to the guides 8. Extending parallel with the sides of the storage units and mounted in bearings intermediate the ends of the rack bars '7 and 9, are

power shafts

10 and 11, there being a pair of these shafts at each side of the structure with one shaft directly above and parallel tothe other and the shafts of both pairs extending across the entire length of the lower ends of the two columns of units at each side thereof. The upper shafts 10 are provided with gear wheels 12 which engage rack bars 9 on one side of the structure and rack bars '7 on the other, and the lower shafts 11 are provided with gear wheels 13 which engage rack bars '7 on the side of the structure first mentioned and rack bars 9 on the other side. In other words, the rack bars 7 on one side (the upper side in Figure 2) are driven by gear wheels 12 of the adjacent upper shaft 10 while the racks '7 on the other side ,(the lower side in Figure 2) are driven by the gear wheels 13 of their adjacent lower shaft 11. Similarly, the rack bars 9 on one side of the structure (the upper side in Figure 2) are driven by gear wheels 13 on their adjacent lower shaft 11 while the rack bars 9 on the other side (the lower side in Figure 2) are driven by the gear wheels 12 on their adjacent upper shaft 10. To simultaneously turn the

shafts

10 and 11 of the two of these shafts, the shafts 10 have secured thereto at one end gears 14 and directly below these gears 14 are gears 15 on the shafts 11, and a rack bar 16 extends at right angles to the shafts 1G andv 11 and between these shafts in engagement with both of the gears 14: and 15, said rack having teeth upon both its top and bottom sides. Motion is transmitted to the power shafts l0 and 11 by this rack bar 16 which in turn is moved endwise'by any suitable means such as an hydraulic cylinder 1'7 containing a piston connected direct- Upon movement of the rack bar 16 in one direction, the power shafts 10 will be rotated in one direction and the power shafts 11 in an opposite direction. Therefore, the two rack bars 9 at each side of each storage unit at the bottom of the columns, will be moved vertically in one direction and the tworack bars '7 at each side of the storage units will be moved simultaneously in an opposite direction, that is the four rack bars 9 at the lower end of each column will be moved upwardly and simultaneously with a downward movement of the four rack bars 7 of each column.

Projecting from the sides of each unit or cage 2 are lugs 18 positioned and adapted to be engaged by corresponding lugs 19 on the rack bars '7. Similarly, the storage cages or units 1 have lugs 20 projecting laterally from the sides thereof and engageable by corresponding lugs 21 provided on the rack bars 9. Because the spacing of the lugs 18 of the units 2 corresponds to the spacing of the racks '7 and their lugs 19, the rack bars '7 engage only the storage units 2. For the same reason, the rack bars 9 engage only the storage units 1. Now, as the

storage units

1 and 2 are alternately arranged in the stacks or

columns

3 and 4 and as the rack bars '7 and 9 operate on the

storage units

2 and 1, respectively, and as these rack bars move in opposite directions, it follows that whenever the rack bars '7 associated with the column 4 have their lugs 19 engaged with the lugs 18 of the bottom unit 2 of this column and are moving downwardly to control the lowering of the column 4, then the column 3 is being raised because the rack bars 9 associated with the column 3 are moving upwardly and have their lugs 21 engaged with the lugs 20 on the bottom cage 1 of such column. During this operation, the rack bars 9 of column 4 are also moving upwardly but are merely idling.

or being moved to a position where their lugs 21 will engage the lugs 20 of the unit 1 next above the bottom unit 2 of the column 4 so that, after the column 4 and the bottom unit 2 thereof have been completely lowered, the rack bars 9 of the column i will take the load of all of the storage units of this column except the bottom unit 2 which will then be free for lateral shifting into the column 3 as will hereinafter be more fully described. During this same phase of the operation the rack bars '1 associated with the column 3 will be idling, that is, moving downwardly to 'a 1 position where they are adapted for engagement with the lugs 18 of the unit 2 that will next be shifted over from the bottom of the column 4 to beneath the raised storage units of the column 3.

In the next cycle of operation the rack bars that have been idling will be working and those that have been working in the previous cycle will be idling. In general, there is a duplicate set of alternately acting lowering mechanism associated with the column 4 and a duplicate set of alternately acting raising mechanism associated with the column 3 and the sets of raising and lowering mechanisms alternately act on the bottom storage unit of their column and the storage unit next above the storage unit of their column.

During the raising and lowering movements, the storage units of the stacks or

columns

3 and 4 are constrained to vertical movement and are held against lateral displacement. This may be accomplished in any suitable way. For the sake of illustration, guide-ways 22 are shown as secured in any suitable manner to the side walls of the well of the building in which the columns are positioned. On each side of each of the several storage units laterally projecting guide 5 rollers 23 are provided and ride in the guide-ways 22 for the purpose mentioned.

Any particular storage unit or cage may be brought into alinement with the entrance and exit ways 6 by shifting the storage stacks or col- .1 of column 3.

umns through the necessary number of shifting or circulating cycles, the number of shifting cycles required in anyparticular instance depending upon the positionof the particular storage unit in the stacks. Each shifting or circulating cycle broadly consists in, first, lowering one of the stacks and raising the other stack and then transferring the bottom unit of the lowered stack beneath the lower end of the, raised stack and the top unit of the raised stack over onto the top of the-lowered stack. In order to effect the transferring of the top'and bottom units 'of one stack to the other, theraised stack is held or supported in raised position and all of the units of the loweredistack, except the bottom unit thereof, are supported slightly above the bottom unit during the transferring or lateral shifting operation. This shifting cycle will be better understood from the following description of the different phases of the operation illustrated in Figure 1.

, When the storage units are in the positions shown in'Figure. 1, the lower unit 1 is in position beneath the column 3, ready to be raised andv thus raise all the units in said column. But, in this phase of the operation, the unit 2 of column 3,

which has its lugs 18 engaged with the lugs 19' i of the rack bars '7 of column 3, is supporting the bars 9 column 3. In like manner, column 4 is being supported when the parts are in the position shown in Figure 1, by the rack bars 7 and the rack bars 9 of column 4 are at the lower ends of their stroke. Consequently the entire weight of both

columns

3 and 4 is taken by the rack bars '7 which, being in engagement with the pinions 13 on the shaft 11 and the pinions 12 on the shaft 10, throws the entire load of both columns onto the motor. This, however, occurs only during the short period when both columns are held fully elevated to permit lateralshifting of the storage units at the top and bottom from one column to the other. In the showing of Figure 1, the lateral shifting has been completed.

In the next phase of the operation appropriate rotation of, the

power shafts

10 and 11 lowers the entire column 4' simultaneously with the lifting of the column 3, the lowering of the column 4 being controlled by the rack bars '7 which have their lugs 19 engaging the lugs'18 of the bottom unit 2 of such coliunn and the elevation of the column 3 being efiected by the upwardly moving rack bars 9 of the column 3 which have their lugs 21 engaging the lugs 20 of the lowermost unit Due to the manner in which the rack bars '7 and 9 are geared together and to the fact that the rack bars 7 take the load of the downwardly moving column 4 while the rack bars 9 of column 3 are simultaneously pushing. the column 3 upwardly,-the upward movementof column 3 is aided by the downward movement of column 4. In other words, the weight of one column is counterbalanced by the Weight of the other column. Thus greatly reducing the power required to operate the lifting mechanism.

It will be noted at the very beginningof the loweringmovement of column 4 and the raising movement of column 3, the column 3, except for the lower unit thereof,-'is supported for a brief interval by the downwardly moving racks 7 thereor", but as the racks 9 of column 3 begin to elevate the bottom unit 1 of column 3 simultaneously with the lowering movementof the racks '7 of column 3 and as the clearance between the units land 2 of the column 3 is but slight, there is .very little lowering of the column 3 because the be in position to engage the lugs 20 of the unit 1 next above the bottom unit 2 of column 4 and thereby elevate all of the units of column 4 except the bottom unit 2 thereof inorder to free the said bottom unit 2 for lateral shifting.

In the position of the parts shown in Figure 1, the unit 1, which is in position at thelower end of column 3, has just been shifted from the lower end of column 4 by means of a suitable truck 24 mounted upon rollers engaging a suitable track 25 extending across the lower ends of the two columns. When the storage unit 1 was lowered in column 4, the truck 24 was in position beneath that column and as the rack bars 7 came into supporting position beneath the unit 2 in that column, said unit 1 was loweredby the rack bars 9 down upon the truck with a clearance space between its upper end and the unit 2 above. At the same time the unit 2 of column 3 was supported in a like manner by its rack bars 7 and therefore the truck 24 with its storage unit 1 in place thereon was then free to be moved or shifted into the position shownin Figure 1 beneath column 3 by any suitable means such as an hydraulic piston and cylinder 26, the rod of which piston is attached in any suitable manner to one end of the truck.

Immediately upon reversal of the movement of the rack bars and with the truck and unit 1 thereon in the position shown in Figure 1, said unit is lifted from the truck and the downward movement of column 4 is simultaneously started.

While column 4 is being lowered and column 3 is being raised, the truck 24 which is now empty is shifted back to position beneath column 4 in readiness to receive the lower unit of that column.

In order that column 3 may be lifted, there must be a vacant space at the top of that column and as shown in Figure 1 and previously described, there is a like vacant space at the lower end of column 4 so that said column may be simultaneously lowered with the lifting of column 3. In order to provide such a vacant space at the upper end of column 3, mechanism is probetween this uppermost unit and the next unit below so that said units may be shifted across into column 4 and into the position shown in Figure 1. This shifting mechanism comprises a truck 27 mounted to roll upon a transverse track 28 extending across the upper ends of the two columns and this truck is moved by means of an hydraulic cylinder 29 having a piston therein with its piston rod attached to one end of the truck 27. Pivotally attached to the ends of the truck are hooks 30 adapted to engage the frame of the storage unit to be shifted and these hooks .are

swung by means of bell cranks 31 pivotally mounted on the truck with one arm of each pivotally attached to the upper end of each hook. The other arm of the bell crank is pivotally attached at 32, each to an end of a piston rod connected to a piston within an hydraulic cylinder 33, there beingtwo cylinders mounted on the truck, one for operating each of the bell cranks and hooks. Each hook is pivotally attached to the truck by means of a pin 34 passing through a cam slot 35 in the hook and this cam slot is. so arranged as to cause each hook to swing beneath and into engagement with the frame of the storage unit and at the same time have an upward swinging movement which will lift the unit slightly and thus provide clearance between this unit and the next unit below. In the position shown in Figure 1 the unit has just been shifted from column 3 to position above column 4 but has not as yet been released by the hooks -30. Immediately upon the starting of the upward movement of rack bars '7, or just previous thereto, the hooks will be operated to release the storage unit and lower it upon the units below in column 4 and then as column 4 is lowered and column 3 is simultaneously being raised, the truck 27 is shifted back into position above column 3 in readiness to raise and shift the uppermost unit therein when said column has reached thelimit of its upward j movement.

In the diagram shown in Figure 5 the hydraulic cylinders 26 and 29 for effecting theshifting movement of the units at the lower and upper ends of the columns respectively, are con nected by suitable fluid pipes 36 which are controlled by a suitable valve 37 so that the shifting movement from one column to the other at both upper and lower ends of the columns will be caused to take place simultaneously. A separate control line 38 extends to the hydraulic in proper timed relation to the shifting of the carriage 27 from one column to the other.

The present arrangement is such that the weight of one column is substantially counterbalanced by the weightv of the other column and by properly distributing the load carried by the several storage units, this balance may be practically maintained and thus the power required for raising and lowering the columns is greatly reduced. Further, with this arrangement the columns are self supporting, that is, substantially the entire weight of each column and its load is supported at the lower end of each column where a suitable foundation may be provided, with this foundation independent of the building, the building simply forming a housing for the machine and a guide for these vertical columns of storage units. The buildingmay therefore be of simple construction and as it is not requiredstorage capacity is secured within a building by the bulk, weight, and strength of the severalunits required to support the load of each column and also by the strength and power required for lifting one column vertically and'simultaneously lowering the other, this power being greatly reduced by the balancing of the two columns.

By the arrangement employing parallel vertical columns comprising separate storage units, together with means for shifting these units from one column to the other, and means for raising and lowering the columns, any particular unit is made available with a minimum of time as these units may be quickly shifted about to bring the desired unit into the desired position and where the apparatus is used for the storage of '3 and the top cage 2 is left at the top of column .4 and the racks are operated then, of course,

column 4 will descend and column 3 will be elevated to permit the bottom unit of column 4 to be positioned to be shifted beneath column 3 and the top unit of column 3 to be shifted over onto the top of column 4. If this operation is repeated the cages will be circulated up through column 3 and down through column 4. Reverse circulation may be effected with the parts positioned as shown in Figure l by moving the bottom unit 1 of column 3 over to beneath column 4 and shifting the topunit 2 of column 4 over onto the top of column 3. Operation of the racks will then lower column 3 and raise column 4. Thus, repetition of this operation will cause the cages to progress downwardly through column 3 and upwardly through column 4.

Obviously any suitable power means may be employed to operate the several parts but for convenience of illustration hydraulic means has been shown. Changes in the operating mechanism and in the construction and arrangement of parts are also contemplated to meet the conditions of the particular installation andI do not therefore limit myself to the particular construction shown.

From the foregoing, it will be understood that the present invention involves a novel method of storing articles which consists first in placing the articles in storage units or cages arranged in stacks or columns with the storage units of each stack or column supported one upon another in load sustaining relation, and second, in bringing anyparticular storage unit to a loading or discharge station by subjecting the stacks tothe necessary number of shifting cycles, each of which shifting cycles consists broadly in displacing the stacks relatively to each other and supporting the stacks after such displacement While leaving certain of the storage units free for individual shifting and then shifting the free storage units from one stack to the other. More particularly, each shifting cycle consists in lowering one stack and raising the other stack, shifting the bottom unit of the lowered stack into position beneath the lower end of the raised stack, and shifting the top unit of the raised stack over onto the top of the lowered stack.

Having thus fully described my invention what I claim is:-

1. In a storage system, the combination of a plurality of separate detached storage units arranged in vertical columns with the units of each column in superposed relation and all supported at the lower end of each column, means for lifting either column bodily a distance equal to the height of one unit and simultaneously lowering the other column bodily an equal distance, means transferring a unit from the lower end of one column to the lower end of the other and into the control of its lifting means while said columns are supported by said lifting means, and means for tranferring a unit from one column to the other at the upper ends of the columns.

2. In a storage system as characterized in claim 1, and wherein said lifting and lowering means is interconnected to counterbalance the weight of one column by weight of the other column during lifting and lowering operations.

3. In 'a storage system as characterized in claim 1, and wherein said lifting and lowering means comprises vertically reciprocable members for each column movable simultaneously in opposite directions.

4. In a storage system as characterized in claim* 1, and wherein said lifting and lowering means comprises vertically reciprocable members for each column movable simultaneously in op- I posite directions, with saidmembers arranged to engage alternate units at the lower ends of the columns, whereby a unit next above the lower unit of the column is engaged and supported by certain of said members and said lower unit is freed of the column to permit the shifting thereof to position beneath the other column. p 5. In a storage system, the combination "of a plurality of separate storage units arranged in vertical columns with said units of each column supported, one upon another, vertically reciprocable members at the lower end of each column,

. said members at the lower end of each column being simultaneously movable in opposite directions and arranged with certain of said members to engage the lower unit in a column and oppositelymoving members to engage the unit next above, and means for simultaneously reciprocating all of said members. I

6. In a storage system, the combination of a plurality of separate storage units arranged in vertical columns with said units of each column supported, one upon another, means for moving one column bodily upward and simultaneously bodily lowering the other column, said means affording a support for all of the units in one column and all except the lower unit in the other column when one column is in fully raised and the other fully lowered position, and a shiftable member to receive and sustain the unsupported unit and shift the same into position below the other column. v V

'7. In a storage system, the combination of a plurality of separate storage units arranged in vertical columns with said units of each column supported, one upon another, means for moving one column bodily upward and simultaneously .bodily lowering the other column, said means comprising vertically reciprocablesets of mombers for each column, the sets of each column being simultaneously reciprocable in opposite directions and arranged to engage alternate units at the lower end of each column, and means for reciprocating all of said members simultaneously, said means being constructed to impart a lift to the load of one column by the downward movement of the weight of the other column.

8. In a storage system as characterized in claim '7, and including horizontally reciprocable means at the upper and lower ends of the columns for transferring the lower unit in one column into position below thev other column and the upper unit in one column into position above the other column.

9. In a storage system as characterized in claim 5,.and including horizontally reciprocable means at the upper and lower ends of said columns, said means at the lower ends of said columns being adapted to receive the lowermost unit in the descending column and shift it into position below the elevated column, and said means at the upper ends of said columnsbeing operative to lift the uppermost unit in the elevated column to clear it from the units below and shift said unit into position above the lowered column. i i

V 10. In a storage system, the combination of a plurality of separate storage units arranged in vertical columns with said units of each column supported, one upon another, means for moving one column bodily upward and simultaneously bodily lowering the other column, said means comprising vertically reciprocable pairs of racks at the lower ends of each column, pairs of shafts,

at the lower ends of the columns, gears on one of theshaftsof each pair in engagement with one of the racks of each pair of racks, gears on the other shaft of each pair of shafts in engagement with the otherrack of each pair of racks, and means for rotating the shafts of the pair of shafts in opposite directions.

11. In a storage system as characterized in claim 7, and including horizontally disposed tracks above and below said columns, trucks movable along their tracks to shift units from one column to the other, the truck at the lower end of the column being arranged to receive and support the lower unit of the column when released therefrom, and means carried by the truck at the upper ends of the columns for engaging, liftingand suspending therefrom an upper unit of one of said columns.

12. In a storage system, the combination of a plurality of detached separate storage units arranged in vertical columns with said units of each column supported, one upon another, means cooperable with the storage units at the lower ends of the stacks for moving one column bodily upward and simultaneously bodily lowering the other column, said means affording a support for all of the units in one column and all except the lower unit in the other column when one col umn is in fully raised and the other fully lowered position, and means for sustaining and transferring the unsupported unit over into position beneath the other column.

13. A storage system comprising a plurality of operated to lower one stack and raise the other and to support all of the units of the raised stack in elevated position and to elevate and support all of the units of the lowered stack except the bottom unit thereof, and means for transferring the bottom unit from the lowered stack to beneath the raised stack and for transferring the top unit of the raised stack over onto the top of the lowered stack.

14. In a storage system comprising a plurality of separate storage units supported one upon another in vertical columns and in load sustaining relation, means for moving one column bodily upward and simultaneously bodily lowering the other column, said means comprising vertically reciprocable sets of racks at the lower end of each column, alternate storage units of each column having means engageable with one set of racks of each column, the other storage units having means engageable with the other set of racks of each column, power means and motion transmission mechanism between the power means and the racks operating to simultaneously reciprocate the sets of racks of each column in opposite directions whereby the racks engage alternate units at the lower end of each column.

15. A storage system comprising a plurality of stacks of storage units, the storage units of each stack being supported one upon another in load sustaining relation, raising and lowering means cooperable with the bottom unit of each stack and with the unit of each stack next above the bottom unit thereofandacting when operated to lower one stack and raise the other and to support all of the units of the raised stack in elevated position and to elevate and support all of the units of the lowered stack except the bottom unit thereof, and means for transferring the bot tom unit from the lowered stack to beneath the i raised stack and the top unit of the raised stack over onto the top of the lowered stack.

16. A storage system including a plurality of stacks of detached storage units supported one upon another in load sustaining relation, means for raising one stack and lowering the other and for supporting the stacks in the position to which they are shifted while leaving the bottom unit of the lowered stack and the top unit of the raised stack free for lateral shifting, means for receiv- 1 ing and supporting the bottom unit of the lowered stack free of its stack and operable to shift the same to beneath the raised stack and means for elevating the top unit or". the raised stack and shifting it onto the top of the lowered stack.

17. A storage system comprising a plurality of stacks of detached storage units, the storage units of each stack being supported one upon another in load sustaining relation, raising and lowering means cooperable with the bottom unit of each stack and with the unit of each stack next above the bottom unit thereof and acting when operated to lower one stack and raise the other and to support all of the units of the raised stack in elevated position and to elevate and support all of the units of the lowered stack except the bottom unit thereof, means for transferring the bottom unit of the lowered stack to beneath the raised stack and means for slightly elevating the top unit of the raised stack and shifting the same over onto the top of the lowered stack.

18. A storage system comprising a plurality of stacks of storage units, the storage units of each stack being supported one upon another in load sustaining relation, two sets of raising and lowering devices at the lower end of each stack and alternately cooperable with the bottom unit of each stack and with the unit of each stack next above the bottom unit thereof and acting when operated to lower one stack and raise the other and to support all of the units of the raisedstack in elevated positionand to elevate and support all of the units of the lowered stack except the bottom unit thereof, said raising and lowering devices being interconnected whereby the weight of one stack counterbalances the weight of the other during the phase of the operation in which one stack is being raised and the other stack is being lowered and means for transferring the bottom unit from the lowered stackto beneath the raised stack and the top unit of the raised stack over onto the top of the lowered stack,

19. In a storage system, the combination of a plurality of separate storage units arranged in vertical columns with said units of each column supported, one upon another, means for moving one column bodily upward and simultaneously bodily lowering the other column, said means comprising vertically reciprocable pairs of racks at the lower ends of each column, pairs of shafts at the lower ends of the columns, gears on one of the shafts of each pair in engagement with one of the racks of each pair of racks, gears on the other shaft of each pair of shafts in engagement withthe other rack of each pair of racks, a power driven member extending between said shafts and having racks on its opposite faces and pinions of said shafts meshed with said racks whereby the weight of the columnsare counterbalanced during the period that one column is being raised and the other column is being lowered.

20. A storage system comprising a plurality of stacks of storage units, the storage units of each stack being supported one upon another in load sustaining relation, two sets'of raising and lowering devices. at the lower end of each stack, each set of raising and lowering devices comprising a plurality of vertically reciprocable members, the

vertically reciprocable members of one set at the lower end of each column being spaced differently from the vertically reciprocable members of the other set at the lower end of the same column but the vertically reciprocable members of one column having the same spacing arrangement as the vertically reciprocable'members of the other column, half of the storage units having lugs thereon positioned to engage the vertically reciprocable members of one set at the lower end of each column, the other half of the storageunits having differently spaced lugs positioned to engage the vertically reciprocable members of the other set at the lower end of each column, and means for moving all of the members of one set upwardly and simultaneously. moving all of the members of the other set downwardly and vice versa. 7

21. A storage system comprising a plurality of stacksof storage units, the storage units of each v stack being supported one upon another in load sustaining relation, two sets of raising and lowering devices at the lower end of each stack, each set of raising and lowering devices comprising a plurality of vertically reciprocable members, the vertically reciprocable members of one set at the lower end of each column being spaced differently from the vertically reciprocable members of the other set at the lower end of the same. column. but the vertically reciprocable members of one column having the same spacing arrangement as the vertically reciprocable members of the other column, half of the storage units havall of the members of the other set downwardly and vice versa, said means interconnecting said sets of vertically reciprocable members so that the weight of one column counterbalances the weight of the other during lifting and lowering operations.

MALCOLM S. CLARK.