GB1602248A

GB1602248A - Storage system for palletized goods

Info

Publication number: GB1602248A
Application number: GB19627/78A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-05-17
Filing date: 1978-05-15
Publication date: 1981-11-11
Also published as: IT7823467A0; FR2391124A1; SE420821B; SE7805510L; JPS5417276A; NL7805281A; CH628852A5; IT1096083B

Abstract

The storage apparatus for palletised goods has a number of storage lines, it being possible for pallets (5) loaded on each storage line to be arranged one behind the other. The storage apparatus is designed in such a way that it is distinguished by low construction cost, easy and accurate controllability and execution of the transport movement in one or both directions, protection of the storage material, high operating reliability, small space requirement and low wear. For this purpose, at least two multi-piece supporting surfaces (3, 4, 6) for the pallets (5) run along the line. Each supporting surface can support the pallets of this line by itself. One (3, 4) of the supporting surfaces is attached in a fixed position, and the other supporting surface, which in the state of rest runs below the level of the fixed supporting surface (3, 4), can be raised above the fixed supporting surface (3, 4) for transporting the pallets (5) along the line and can be moved in the raised state in the line direction for transporting the pallet by little more than a pallet length (measured in the line direction). It can then be lowered again and returned into the initial position. <IMAGE>

Description

(54) STORAGE SYSTEM FOR PALLETIZED GOODS (71) I, MAX KErrNER of Ottobrunnerstrasse 1. 8000 Munchen 83, Federal Republic of Germany, formerly of Prinzregentenstrasse 79, 8000 Munchen 80, Federal Republic of Germany, a citizen of the Federal Republic of Germany, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to pallet storage apparatus and more particularly to such apparatus comprising a plurality of parallel elongate storage compartments each adapted to store pallets one behind the other longitudinally thereof.

While in a storage facility of this kind, the storage compartments could extend at a slight angle to the horizontal, they are usually disposed in a horizontal plane. In the simplest case the storage facility consists of a single compartment, for example when it merely serves as an intermediate deposit in a materials handling system. Usually, however, it comprises a plurality of adjacent and superposed storage compartments to ensure optimal space utilization. Preferably, such storage compartments are designed for continuous operation of the kind where the pallets are fed to the compartments from one end and discharged at the other end; feeding and discharge, however, may be required to take place at one and the same end of the compartment.The former design is costly, while the latter construction suffers from the disadvantage that palletized goods fed first to the storage compartment, are discharged last, while those fed last are discharged first.

The prior art includes storage facilities wherein the individual storage compart ments are provided with roller conveyors which convey the pallets in longitudinal direction by gravity or by means of special driving mechanisms. This type of construction has a number of drawbacks. Roller conveyors are costly. Pallets can not be placed in storage by being moved, optionally, in longitudinal or transverse direction, but only by means of runners extending longitudinally relative to the compartment; when the pallets to be stored are moved transversely, however, the construction cost is materially reduced.A further dsadvan- tage of the roller conveyor resides in that the pallets, on passing across a roller con veyor, are exposed to deformation and 1 more particularly, to a kind of corrugation, due to the weight of the goods carried by the pallet, an effect which of course, is most undesirable. When the storage compartments are provided with chain conveyors, the construction is complex and costly. Moreover, in the case of chain conveyors, the pallets are required to be slidingly displaced from the chains; this construction requires very great driving forces, unless the drawbacks of a roller type storage system are accepted.

A further drawback of these two types of construction results from the fact that they do not permit storing in a compartment several pallets on top of one another, although it is often desired that the conveyor apparatus provided for each compartment, accommodates as many loaded pallets as possible per unit of length. When using a roller conveyor in the compartment, a stack of two or three superposed pallets would rock back and forth due to the deformation noted above. With chain conveyors, the sliding resistance of a series of pallet stacks conveyed in the compartment, would be quite excessive.

It is an object of this invention to provide improved pallet storage apparatus.

Accordingly, the present invention consists in pallet storage apparatus comprising a plurality of parallel elongate storage compartments each adapted to store pallets one behind the other longitudinally thereof and a transverse roller conveyor co-operating with corresponding ends of the compartments for conveying pallets to the compartments, each storage compartment having a pair of fixed load rails extending longitudinally thereof to support pallets and a lifting rail extending longitudinally of the compartment between the load rails, the lifting rail being movable from a lower position beneath the load bearing surface of the load rails to an upper position above said surface in which upper position the lifting rail can be displaced longitudinally to convey pallets along the compartment, wherein the load beanng surface of the roller conveyor is coplanar with said load bearing surface of the load rails and wherein the lift rails are adapted in their lower position to extend between rollers of the conveyor, whereby a pallet positioned on the conveyor adjacent the end of a compartment may be lifted on the associated lifting rail, conveyed into the compartment through longitudinal displacement of the lifting rail and deposited on the associated load rails through subsequent lowering of the lift rail.

The invention is illustrated in the drawings accompanying this specification which show quite schematically, a preferred embodiment of the invention which of course, is susceptible of numerous modifications within the letter and spirit of the present disclosure.

In the drawings, Fig. 1 is a horizontal section through part of a palletized storage facility according to the invention compnsmg a number of storage compartments next to as well as superposed on one another, each compartment being capable of accommodating several series of loaded pallets superposed on one another; Fig. 2 shows, on an enlarged scale, a vertical section through part of the storage building of Fig. 1, viewed from the feed side, i.e.

from the bottom of Fig. 1; Fig. 3 shows, on an even more enlarged scale, a longitudinal section through a rail unit composed of two stationary rails and a movable rail extending therebetween; Fig. 4 shows in actual size, the section VI VI of Fig. 3; Fig. 5 shows the section III - III of Fig. 4, the displaced position of the lifting wedge, however, being different form that shown in Figs. 3 and 4; Fig. 6 shows, on about the same scale as that used in Fig. 2, the lifting device positioned in front of the transverse conveyor, viewed from the left in Fig. 2, and Fig. 7 is a front view, in perspective, of an entire storage facility according to the invention, including feed and discharge elevators.

Referring to the drawings, and first to Figs. 1 and 2, the storage apparatus or facility facility illustrated quite diagrammatically, comprises a number of vertically disposed double T-beams 1 and horizontal crossbeams 2 extending therebetween.

Each storage compartment of the facility, as seen in Fig. 2, is limited on the sides by a series of vertical double T-beams 1, and at top and bottom by a series of horizontal cross-beams 2. This construction, of course, is conventional and may be replaced by any other known construction compatible with the invention. The vertical distance between the cross-beams 2 permits the stacking of three loaded pallets 5 on top of one another, in each storage compartment.

Fig. 2 shows the bottom pallet 5, and part of the pallet in the middle of the stack. In Fig. 1, which is a horizontal section through part of the storage facility, one of the storage compartments is filled with pallets 5.

Two pairs of stationary rails 3 and 4 are mounted on the cross-beams 2 to extend parallel to one another and in longitudinal direction along the bottom of each compartment. The rails 3 and 4 are spaced from one another by a distance such that each pair of rails extends at least approximately below a runner or row of columns of the loaded pallet 5 placed on the rails to be stored in the compartment, as shown in Fig.

2.

A movable rail 6 is positioned between the adequately spaced rails 3 and 4 of each pair of stationary rails; rail 6 is displaceable not only along a horizontal plane, i.e. in Fig.

2 at a right angle to the plane of the drawing, and in Fig. 1 from top to bottom, but also vertically, i.e. in Fig. 2 upward or downward, and in Fig. 1 at a right angle to the plane of the drawing. It is apparent from Fig. 2 that when the movable rails 6 are raised from their position in Fig. 2, they will raise the pallets 5 resting on the stationary rails 3 and 4, will carry the pallets 5 along in the course of horizontal displacement of the rails 6 in longitudinal direction in the compartment, and on return to the lowered position shown in Fig. 2, will redeposit the pallets 5 on the stationary rails 3 and 4. Each horizontal step in the displacement of the movable rails 6 has a length corresponding to the length of a pallet 5 in longitudinal direction in the compartment, plus a small safety margin in the order of magnitude of 5 percent of this length of the pallet.

In order to feed the pallets 5 into individual compartments forming part of the honeycomb type assembly of compartments, a transverse or cross-conveyor is provided on each floor in the form of a roller conveyor 7 disposed on the feed side of the storage building. The carrying surface of the roller conveyor 7 is disposed in the plane of the supporting surfaces 3a and 4a on the stationary rails 3 and 4 on the same floor. A pair of rails 30 extends in front of the roller conveyor 7, and a fork-lift truck 31 is mounted for displacement along the rails 30. The fork-lift truck 31 has a portal 32 onwhich a slide 33 carrying the lifting fork 34, is mounted for sliding, upward and downward displacement. The lifting fork 34 is horizontally displaceable on the slide 33, in the direction in which the fork extends.

As indicated in Fig. 7, an analogous system of transverse conveyor and lifting device is provided on the discharge side on each floor.

If, for example, the roller conveyor 7 has moved a loaded pallet 5 in front of the feed opening of a compartment, the fork-lift truck 31 engages, with its lifting fork 34, the pallet 5 and lifts the same to a height permitting the transverse conveyor 7 to move a second pallet into the space vacated by the first pallet. At this point, the fork-lift truck 31 deposits the first pallet on top of the second pallet as shown in Fig. 6. The fork 34 is withdrawn from the upper pallet 5 (downward in Fig. 1 and toward the right in Fig. 6) and is moved downward to then re-engage the stack underneath the bottom pallet.The two superposed pallets S are lifted to a height permitting the transverse conveyor 7 to feed a third pallet into the empty space below the two elevated pallets, which in turn are deposited on the third, bottom pallet, whereupon the fork 34 is withdrawn from the pallet in the center of the pallet "tower" (toward the right in Fig. 6). The stack of pallets is raised a small distance by raising the movable rails 6, and by horizontal displacement of the rails 6, is displaced by one step, to a location above the ends of the pairs of stationary rails 3 and 4, to be deposited thereon by a lowering of the rails 6, as described below in detail. For this purpose, the movable rails 6 may extend beyond the feed opening of each compartment, between two rollers of the roller conveyor 7, to the far side thereof relative to the compartment, as shown in Fig. 1.This arrangement eliminates the need for additional equipment for conveying the stack of pallets assembled by the lifting device 31 in front of the entrance of the compartment, into the compartment itself.

When another compartment is to be charged, the lifting device 31 is simply moved on the track 30 to the entrance of this compartment.

The discharge of the storage compartments is taken care of at the other end of the storage building, in an analogous manner.

While Figs. 1 and 2 show the arrangement of the stationary and the movable rails in the storage compartments, only quite diagrammatically, Figs. 3 to 5 illustrate a preferred embodiment of this rail system, which will now be described in greater detail.

As shown in Figs. 3 to 5, each pair of stationary rails comprises two rails 3 and 4 made, for example, of rolled or drawn steel and having C-profiles the openings of which face one another. Disposed between the two rails 3 and 4 of each pair, and at a small horizontal distance therefrom of e.g. one half to one centimeter, is the movable rail 6 which comprises, as shown in Fig. 4, e.g. a rolled or drawn steel channel or U-profile the opening of which faces downward.

Each movable rail 6 is provided, at intervals corresponding to one pallet length plus a safety margin, or a multiple or fractional integer thereof, with vertical carrying plates or brackets 11 mounted inside the vertical sides 6a of the rail 6. The carrying plates 11 may be mounted on the arms 6a, for example, by means of screws 10, as shown in Fig.

4. Near their upper ends they have juxtaposed bores 12 which accomodate, with press or sliding fit, a horizontal transverse axis 13 extending therebetween.

A rotary member or idler 15 axially held in position by spacer bushings 14 is mounted, by a needle bearing, in the center of axis 13. The idler 15 runs on the inclined surface of a lifting wedge 17. The lifting wedges 17 are mounted, for example by welding, on a supporting rod 18 extending over the length of the movable rails 6, as indicated in Fig. 5. The spacing of the lifting wedges 17 from one another corresponds to the spacing of the pairs of carrying plates or brackets 11.

The lifting wedges 17 are supported by the supporting rod 18 which for example, may be made of drawn rectangular tubular steel. The rod 18 is mounted, vertically underneath the rolls 16, on a strong transverse rotary member or shaft 20 on which it rolls. This shaft 20 is supported, in its position vertically below the roll 16, in two elongated slots lia which are disposed in the carrying plates 11 and are open at the bottom, in 2 vertically displaceable manner apparent from Figs. 4 and 5. The movable rail 6 is prevented from being laterally displaced in axial direction of the shaft 20, by annular guides 21 mounted, e.g. shrunk on the shaft 20 which as shown in the drawing, permit a certain lateral play of the rail 6, just as the elongated slots 11 a are a little wider than the diameter of the shaft 20.The shaft 20 is secured against axial displacement by abutment of its ends against the vertical webs of the stationary rails 3 and 4, and carries, for this purpose, protective caps 23 which, for example, may be made of wearresistant plastic and may be pressed on the ends of shaft 20.

Near its ends shaft 20 is supported by roller bearings 22 which may be pressed or shrunk on the shaft. The outer rings of the roller bearings 22 run, as shown on Fig. 5, on the interior surfaces of the bottom portions of the stationary C-profile rails 3 and 4, in longitudinal direction of the rails.

At one end, and preferably at the end toward which the lifting wedges 17 incline, the draw rod 18 is linked to a servo-motor 24 having a hydraulic piston which in turn, is linked to the movable rail 6, as shown in Fig.

3.

As also shown in Fig. 3, the movable rail 6 is linked at the other end, to a servo-motor 25, preferably also of the hydraulic type. At its other end the servo-motor 25, in turn, is linked to a fixed member, e.g. a plate 27 welded between the stationary rails 3 and 4.

The servo-motors 24 and 25 are not required to be provided separately for each movable rail 6. Thus, for example, a servo-motor may serve to move both rods 18 of a compartment, and both movable rails 6 in one compartment may be rigidly connected with one another, for joint longitudinal displacement by a servo-motor shared in common.

The installation described above operates as follows: Let it be assumed that the movable rails 6 of a compartment are in their lowered position of rest. In order to cause the rails 6 to perform a lifting and conveying step, the servo-motor 24 is actuated to move the rods 18 toward the right in Fig. 3. This causes the idlers 15 to roll on the lifting wedges 17 upward to thereby elevate the movable rails 6 which in turn, with their supporting surfaces 6 b, lift the pallets which rest on the stationary rails 3 and 4. or on the roller conveyor 7. pto this point, the movable rails 6 are not yet displaced horizontally.The lifting stroke is effected solely by the movement of the wedge and rod system 17, 18 between the idler 15 and the shaft 20, which involves rotation of the idler 15 on the axis 13, aud rotation of the shaft 20 in the antifriction bearing 22 which possibly, may bring about a very minor longitudinal displacement permitted by the play afforded by the elongated slots 11 a.

On continuing the operation, the servomotor 25 is caused to displace the movable rail 6 horizontally by a distance exceeding slightly one pallet length. As the movable rail 6, through the servo-motor 24 which is blocked at this point, is rigidly connected with the rod 18, the movable rail 6 remains in its elevated position and conveys the pallets it carries, in the longitudinal direction of the rails. During this part of the operation, the movable rail 6 rolls, by means of the outer rings of the anti-friction bearing 22, on the interior bottom portions of the stationary rails 3 and 4.On reaching the desired end position of the rail 6, the servo-motor 25 is inactivated, and the servo-motor 24 is actuated to effect displacement in the opposite direction, with the result that the wedge and rod system 17, 18 is drawn between the idler 15 and the shaft 20, and the movable rail 6 is lowered to deposit the pallets it has carried, once again on the supporting portions 3 a and 4 a of the stationary rails 3 and 4.

A particularly suitable arrangement may provide movable rails of a length corresponding to that of the stationary rails plus the width of a transverse conveyor. Interference of the movable rail 6 with the transverse conveyor when the latter is in motion, is avoided by vertical or horizontal displacement of the movable rail 6.

In the event the pallets are not required to be stacked on top of one another in the compartments, the clear height of the compartments may be reduced correspondingly, and the lifting devices 31 and the track 30 therefor may be dispensed with; also, the building construction is not required to be as strong as in the case of the pallet "towers".

Viewed in its broader aspects, the invention provides a storage facility for palletized good distinguished by an economic building construction, easy and precise control and conveying operation in one or both directions in each compartment, prevention of damage to the palletized goods and the pallets conveyed to and stored in the compartments, great safety of operation, reduced space requirements and little wear. If desired, each compartment may accomodate a series of superposed, stacked loaded pallets, provided the compartments are dimensioned to have the necessary height.

A particularly significant advantage resides in the ease of control of displacement of the palletized goods in the compartments, as it facilitates the automation of the entire storing operation, i.e. the fully automatic supply and discharge of the pallets. This does not mean, however, that the invention is limited to fully automatic storage facilities, as its advantages are important also if only part of the storage operation is automated.

The invention renders it possible to elevate a series of loaded pallets resting on a stationary support, by means of a movable support and to redeposit the pallets following a longitudinal displacement over a distance preferably corresponding to the length of a pallet (its extension in longitudinal direction in the compartment) plus an addi tional small safety margin. Inasmuch as the movable supporting member extends over the length of the compartment, all pallets disposed in the compartment are uniformly lifted, displaced and redeposited, whereupon the movable support returns to its starting plane and comes to rest, or else, following the deposit thereon of another pallet, conveys the entire series of pallets for another step. The vertical displacement in this operation may be kept very small. In its position of rest, the movable support must extend below the supporting portions of t;ie stationary supports only sufficiently for the pallets to rest on the supporting portions of the stationary supports without being carried along again by the movable support in the course of its return displacement. For conveying purposes, the movable support is required to be elevated above the supporting portions of the stationary supports, only to the extent that the pallets are safely supported by the movable support, to be carried along thereby.Dependent on the design of the two supports, it is normally sufficient that the movable support, in its position of rest, extends from a few millimeters to one centimeter below the plane of the stationary support, while in elevated, conveying position, it extends from a few millimetres to one centimeter above the plane of the stationary support.

The upward and downward displacement of the movable supporting portion 6 b ro- ceeds at least approximately vertically. This has the important advantage that it avoids slip between the pallets and the movable support in the course of raising and lowering of the pallets.

A particular advantage of the invention derives from the fact that the stationary support is not required to be a distinct structural member, but may be integrated as a load carrying building component e.g. with the steel construction of the storage building. The supporting portions may take many forms. For example, two comb-shaped supporting systems extending in longitudinal direction in the compartment, may be provided, one being stationary while the other is displaceable. It is true that with this arrangement. a yery considerable vertical elevation is required. More advantageously the two supports are provided as distinct elements extending parallel to one another longitudinally through the compartment, so that the movable support, in the course of its displacement, is not interfered with by the stationary support.For this reason it is preferred that at least one supporting portion, and preferably both supporting portions, form part of a plurality of rails extending through the compartment in longitudinal direction. The stationary supports may be formed, for example, by two angle rods forming part of the steel construction of the storage building, while the movable supporting portion may be part of a rail extending midway between the two angle rods, this rail having the required width or having at least at the top, a supporting portion of the width required. Particularly preferred is the arrangement of the preferred embodiment of the invention described above in detail, where the supporting portions at the top of the stationary rails, are disposed closely adjacent to the supporting portions at the top of the movable rails.This arrangement accomplishes, for example, that the pallets are supported precisely underneath the runners, or the columns or posts connecting the top and bottom plates, of the pallets, this precise support being afforded by the stationary rails as well as by the movable rails. A further advantage of this arrangement resides in that the system composed of two stationary rails and one movable rail, may be prefabricated as a complete unit, which either already contains the servo-- motors for the raising and lowering, as well as the horizontal displacement of the movable rail, or is adapted to be readily connected with such servo-motors which can lift or shift all movable rails in a compartment simultaneously.

The movable rails, preferably, are provided in the form of U-profile members or channels open toward the bottom. This design enables the lifting mechanism to be arranged below the movable rails, so that this mechanism is protected to a far reaching extent, against contamination by matter dropped from above. This arrangement also ensures rigidity of construction of the movable rail, in a simple fashion.

More than mere design advantages accrue from the feature of the invention involving the use of portions of the stationary rails as sliding bearings for the movable rails. This feature also facilitates the provision of the stationary rails as prefabricated structural elements assisting in the construction of the storage building. The sliding support of the movable rails on portions of the stationary rails, of course, must be so arranged that the tops or heads of the movable rails extend, in the position of rest, below the tops or heads of the stationary rails.

The feature of the invention involving the raising and lowering of the supporting portion of the movable rails by means of flat wedges arranged in longitudinal direction relative to the compartment, to roll in the same direction on a system of rotary members (exemplified by idler 15, shaft 20 and outer ring of bearing 22) ensure a lifting operation requiring but little power and low construction cost. The use of the rotary members eliminates sliding friction between the wedges and the rails. The structural height of such a wedge-tyPe lifting mechanism is small, and the production cost is also small.

The provision of wedges and rotary members which in the longitudinal direction of the compartment, are slideably displaceable relative to one another, enables the movable rails to be raised and lowered in the absence of any horizontal displacement. The displacement of wedges and rotary members relative to one another is preferably effected by a servo-motor, and preferably one of the hydraulic type.

In addition to the provision of the stationary and movable supporting portions as parts of rails extending side by side, the wedge-type lifting mechanism is an important feature of the invention. Thus, for example, the wedge having a downwardly inclined face, may be mounted on the movable rail to roll on an idler which in turn, is mounted on a shaft which on both sides of the idler, has carrier rollers which run on lateral flanges of the two stationary rails; the stationary rails between themselves, accomodate the movable rail. For lifting purposes all that is required, is a displacement of the roller shaft in longitudinal direction relative to the movable rail which is held in place and therefore, is unable, at this point, to move in longitudinal direction.

Subsequently, the movable rail, rolling on the carrier rollers, is displaced in the longitudinal direction of the compartment, over the desired distance, preferably also by means of hydraulic servo-motors. In the course of this operation, the roller shaft is displaced along with the movable rail.

Manifestly, the invention contemplates the provision of quite a number of lifting wedge mechanisms for each movable rail, as the movable rails may have a relatively great length of e.g. from ten to fifty meters. An efficient arrangement includes for each movable rail. at least one lifting wedge mechanism disposed below each pallet.

Either the wedges (17) or the rotary members (20, 22) may be mounted on a longitudinal rod (18) susceptible of being displaced relative to the movable rail (6) by means of a servo-motor (24) mounted on the latter.

In a preferred embodiment of the invention shown in Fig. 5, the wedges are mounted for longitudinal displacement relative to the movable rails; the movable rails rest, by means if idlers mounted for rotation thereon, on the wedges; and the wedges roll on rotary members carried by the movable rails at least approximately vertically underneath the idlers, the rotary members preferably being arranged to roll on portions of the stationary rails. This arrangement is preferred as it is distinguished by outstanding simplicity.

Also preferred is the arrangement involving movable U-profile or channel-type rails which in their interior support, by means of axis members, idlers rolling on the wedges, while the rotary members carrying the wedges, are provided as shafts which by means of anti-friction bearings disposed at their ends, roll on the bottom portions of the re-entrant flanges of two stationary double rails formed of C-profile bars, the openings of which are disposed to face one another.

This construction has the advantage of requiring only simple profiles for the stationary and movable rails. Another significant im rovement results from the fact that the rolls running on the stationary rails, are located under a roof which provides far reaching protection from contamination.

Where the storage facility includes a plurality of adjacent compartments with entrances disposed in one line, and further includes a transverse roller or crossconveyor extending in front of these entrances for the purpose of feeding or discharging pallets to and from the compartments, the invention contemplates movable rails which in their end position on the side of the roller conveyor, extend between rollers of the roller conveyor, the conveying surface of which is disposed in the same plane as the supporting portions of the stationary rails.

Due to this arrangement, the movable rail is enabled to lift pallets resting on the roller conveyor and convey the same into the storage compartment. This arrangement is particularly advantageous as it permits the transfer of the pallets or stacks of pallets from the roller conveyor extending transversely to the compartments, to the latter by especially simple means, thus eliminating the need for a distinct additional transfer device.

In the arrangement described in the preceding paragraph, the compartments preferably have a height sufficient for permitting the storage of several pallets stacked on top of one another.

In this event, the invention contemplates the provision of at least one lifting device arranged to move along the roller conveyor, and designed to stack loaded pallets on top of one another, or remove pallets from a stack thus produced. This arrangement permits the storage of several, and preferably three rows of pallets in each compartment. In addition to excellent space utilization, this arrangement has the advantage of simple, precise and economical feed and discharge of pallets to and from pallet stacks.

In the operation of the embodiment of the invention just described, a loaded pallet is moved by the transverse conveyor in front of the entrance of a compartment, and is elevated by the lifting device sufficiently for another pallet to be placed underneath the first pallet, which is then lowered so it will rest on top of the second pallet. The lifting device may now lift both pallets, and following introduction of a third pallet in the space thus vacated, may lower the two pallets again so they are deposited on the third pallet last introduced into the stack. Depending on the dimensions and weight of the loaded pallets, the operation could be continued until limits set by the height of the compartment and permissible weight are reached. The completed stack is conveyed into the interior of the compartment in the manner described above. When discharging pallets from a compartment, a stack of pal lets is first deposited on the transverse con veyor on the discharge side of the storage building; a lifting device raises all but the bottom pallet, and the bottom pallet is carried away by the transverse conveyor. The lifting device then deposits the remainder of the stack on the transverse conveyor, and raises again the pallet or pallets remaining in the stack, except for the bottom pallet, the operation being continued until the uppermost pallet in the stack has been deposited on the transverse conveyor.

It was to be understood that there is no desire to- be limited to the details of construction and operation shown and described, as numerous modifications within the scope of the appended claims may occur to persons skilled in the art.

WHAT WE CLAIM IS: 1. Pallet storage apparatus comprising a plurality of parallel elongate storage compartments each adapted to store pallets one behind the other longitudinally thereof and a transverse roller conveyor co-operating with corresponding ends of the compartments for conveying pallets to the compartments, each storage compartment having a pair of fixed load rails extending longitudinally thereof to support pallets and a lifting rail extending longitudinally of the compartment between the load rails, the lifting rail being movable from a lower position beneath the load bearing surface of the load rails to an upper position above said surface in which upper position the lifting rail can be displaced longitudinally to convey pallets along the compartment, wherein the load bearing surface of the roller conveyor is coplanar with said load bearing surface of the load rails and wherein the lift rails are adapted in their lower position to extend between rollers of the conveyor, whereby a pallet positioned on the conveyor adjacent the end of a compartment may be lifted on the associated lifting rail, conveyed into the compartment through longitudinal displacement of the lifting rail and deposited on the associated load rails through subsequent lowering of the lift rail.

2. Apparatus according to Claim 1, wherein the lifting movement and longitudinal displacement of each lifting rail takes place in a plane which is substantially vertical.

3. Apparatus according to Claim 1 or Claim 2, wherein two pairs of fixed load rails are provided in each compartment, there being a lifting rail extending between the load rails of each pair.

4. Apparatus according to any one of the preceding claims, wherein the lifting rails comprise U-profiled members open at the bottom.

5. Apparatus according to any one of the preceding claims, wherein the lifting rails are mounted for lifting and lowering movement relative to respective carriers which are displaceable longitudinally of the associated fixed rails.

6. Apparatus according to any one of the preceding claims, wherein the means for lifting and lowering the lifting rails comprise wedges extending longitudinally of the compartment.

7. Apparatus according to Claim 6, wherein the wedges or rotary members co-operating therewith are mounted on the carrier and are displaceable relative to the lifting rails by means of a servo-motor secured to the lifting rail.

8. Apparatus according to Claim 5, wherein the carrier is mounted on axles which are provided at their opposite ends with bearings, the corresponding fixed rails having C-profiles with their openings facing one another and said bearings running within the respective openings.

9. Apparatus according to any one of the preceding claims, wherein the longitudinal displacement of the lifting rail relative to the load rails is effected by means of a hydraulic servo-motor.

10. Apparatus according to any one of the preceding claims, including compartments high enough to permit storage of several superposed pallets, and comprising a lifting device displaceably mounted on the roller conveyor, said lifting device including means for stacking pallets on top of one another and for removing pallets from a stack thus produced.

11. Apparatus according to Claim 10, wherein the lifting device is a fork-lift truck, said truck comprising a lifting form extending in the longitudinal direction of the compartment and adapted to move in this direction over a distance corresponding at least to the length of a pallet in this direction.

12. Apparatus according to Claim 11, wherein the lifting device comprises means for lifting a load pallet to a height exceeding by a small margin the height of a loaded pallet.

13. Apparatus according to any one of the preceding claims, wherein the storage compartments are arranged in two or more floors, there being a transverse roller conveyor for each floor.

14. Pallet storage apparatus, constructed arranged and adapted to operate substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. bottom pallet, and the bottom pallet is carried away by the transverse conveyor. The lifting device then deposits the remainder of the stack on the transverse conveyor, and raises again the pallet or pallets remaining in the stack, except for the bottom pallet, the operation being continued until the uppermost pallet in the stack has been deposited on the transverse conveyor. It was to be understood that there is no desire to- be limited to the details of construction and operation shown and described, as numerous modifications within the scope of the appended claims may occur to persons skilled in the art. WHAT WE CLAIM IS:

1. Pallet storage apparatus comprising a plurality of parallel elongate storage compartments each adapted to store pallets one behind the other longitudinally thereof and a transverse roller conveyor co-operating with corresponding ends of the compartments for conveying pallets to the compartments, each storage compartment having a pair of fixed load rails extending longitudinally thereof to support pallets and a lifting rail extending longitudinally of the compartment between the load rails, the lifting rail being movable from a lower position beneath the load bearing surface of the load rails to an upper position above said surface in which upper position the lifting rail can be displaced longitudinally to convey pallets along the compartment, wherein the load bearing surface of the roller conveyor is coplanar with said load bearing surface of the load rails and wherein the lift rails are adapted in their lower position to extend between rollers of the conveyor, whereby a pallet positioned on the conveyor adjacent the end of a compartment may be lifted on the associated lifting rail, conveyed into the compartment through longitudinal displacement of the lifting rail and deposited on the associated load rails through subsequent lowering of the lift rail.