DK168565B1 - A stackable trolley - Google Patents

Description

in DK 168565 B1

The invention relates to a trolley of the kind specified in the preamble of claim 1.

Such trolleys are used, among other things, in large super-5 market chains, where the goods are packed in packages with modular dimensions. At a distribution center the goods are placed on trolleys and then sent to the individual retail stores. Transport takes place in trucks. The modular dimensions of the goods ensure maximum utilization of the truck's floor area during transport. When the trolleys are sent back to the central station, it will often be appropriate to stack the trolleys as they will thus be easier to handle while taking up less floor space during transport. There are a number of trolleys that can be stacked under the 15 return transport. However, these wagons have a number of drawbacks, as the wagons are not fixed relative to each other. Therefore, during the transport, the carriages will be able to be displaced and this displacement will propagate through the stack of carriages, so that there will be a high risk of the stack tipping over. The wagons are usually very sturdy and thus heavy, which is why an overturned stack can easily injure an operator. This risk is present both during the stacking itself and during the subsequent handling.

25

French utility model # 2 308 525 indicates a stackable trolley where the center of gravity of the stacked trolleys is shifted upwards in the stack. The carriages are mutually fixed in that the wheels of a carriage are taken up and secured in a frame of the carriage arranged below. If a certain number of wagons are stacked, e.g. about a dozen pieces, the center of gravity of the pile will be shifted substantially relative to the outer wheel set of the lower carriage, which will give a pronounced risk of towing instability.

French Patent No. 2,132,971 discloses a construction of a trolley in which the wagons are stacked directly on top of one another.

35 2 DK 168565 B1

There is no possibility of compressing the stack, whereby the height of a stack will substantially match the height difference between the floor level and the surface of the trolley upon which the next trolley rests, multiplied by 5 by the number of trolleys. French Patent No. 2 126 521 discloses a trolley structure of the same type.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a trolley of the kind in which empty trolleys on the return road 10 can be stacked and thus compressed. This stacking must be done in such a way that the operator is not exposed to the risk of the stack toppling as a result of displacement of the stack's center of mass.

This object is achieved according to the measures specified in the characterizing part of claim 1. Hereby a trolley can be placed on top of another trolley, with the one wheel set of the upper trolley being accommodated in the associated openings of the lower trolley, while the second wheel set of the trolley protrudes beyond the end of the lower trolley. The two carriage bottoms will be locked with respect to longitudinal displacement, since the cooperating positioning means of the carriage bottoms are engaged with each other. It is especially important to achieve good stability in the longitudinal direction of the carriages, since it is here that the carriages are displaced relative to each other by stacking. The direction by which the trolleys are displaced by stacking is determined by the fact that at the one end of the trolley in the area around the wheels placed there are provided barriers which prevent the pick-up of the wheels on a second trolley placed on top of the first trolley. This prevents errors in stacking the trolleys to a large extent, otherwise these errors occur frequently in the prior art with the risk of personal injury. These operating errors will also be avoided even if the user has not undergone any training or training in the system.

3 DK 168565 B1

The wheels being mounted as defined in claim 2, it is achieved that the brackets form part of the positioning means, with a longitudinal staggered carriage being locked on top of it, by its wheels or wheel forks abutting the brackets of the carriage below. The other positioning means can thus be very simple. In that the barriers are configured as claimed in claim 3, it is possible to obtain a very effective barring against complete uptake of the wheels by placing the carriage bottom frame against 10 base frame. When stacking, it is advantageous to place trolley bottom # 2 offset on top of trolley # 1 so that the wheels of trolley # 2 extend outside. Trolley floor 3 is then placed so that its wheels rest on the brackets of trolley No. 1. Here, the bottom of the carriage floor # 2 will act as fixing means for the wheels of the carriage floor # 3. This results in extremely safe control of even high stacks.

As set forth in claim 3, there may be different track widths for the fixedly oriented wheel set and the pivotally arranged wheel set. This will ensure that the trolleys can only be stacked when they are oriented the same. say that stacking can only be achieved when the swivel wheel sets are facing in the same direction. The bottom frame may advantageously have upwardly extending flanges at the ends where these flanges serve as end stops on the trolley's barn. As these flanges as claimed in claim 5 can be broken at one end of the trolley, the longitudinal stiffening elements of the trolley can be accommodated in the recesses of the flanges. This also achieves a particularly effective retention of two frame 30 against frame placed carriages in the transverse direction. The positioning means can then advantageously be designed as set out in claim 6. By having the bent cross member formed as set forth in claim 7, good mechanical contact between the positioning means is obtained and at the same time the user is given a good visual indication of which way the trolleys should turn. by stacking. As stated in claim 8, the brackets may be provided with additional control means by which the swivel wheels are retained in a predetermined position. This can be a supplement to the control that is otherwise obtained by the proper construction of the trolley. Here, the trolley will be suitably sized so that the 5 wheels will stand on a bracket underneath the trolley and just touch the end elements of the bottom frame. In the lateral direction, the wheels are then guided by abutment against the side elements of the bottom frame or against the longitudinal stiffening elements. By the measures specified in claim 9, 10 space is allowed for the pivot wheels of the pivot wheels.

The invention will be explained in the following with reference to a preferred embodiment and with reference to the drawing, in which: FIG. 1 shows a preferred embodiment of a trolley according to the invention; FIG. 2 shows a number of carriages of the embodiment of FIG. 1 in which the carriages are stacked in such a way that each other carriage is displaced in its longitudinal direction; and FIG. 3 shows a number of carriages of the type shown in FIG. 1, where the carriages are stacked directly on top of one another.

25 In FIG. 1 shows a trolley according to the invention. The trolley is in its entirety denoted by reference numerals light 10 and has a bottom frame consisting of two end pieces 12 and two side pieces 13. The end and side pieces 12, 13 are rectangular profile tubes welded together in the corners. The end pieces 12 of the trolley are externally provided with two upwardly facing end profiles or flanges 25, 26 which are bent at the corners 28 of the trolley so that they appear rounded. This is an advantage of using the trolley, as it thereby facilitates steering into narrow passages, e.g. when loading onto trucks. The upwardly extending flange 26 at one end of the carriage is unbroken across the carriage. The flange serves to retain goods placed on the trolley 10 when these goods do not have a modular dimension and therefore cannot be retained in the inner transport surface of the trolley. The second flange 25 serves the same purpose, 5 but is otherwise broken by a series of recesses 27, the function of which can be understood by the following.

The trolley here has four longitudinal stiffening elements 16, 18 welded to respective end pieces 12. A 10 transverse stiffening element 14 which divides the transport area of the trolley 10 into two halves is welded partly to the frame side pieces 13 and partly to the stiffening elements 16, 18. transverse stiffening element 14 lies in the same plane as the upper side of the bottom frame, while the transport area formed by the stiffening elements 16, 18 is recessed. The transverse element 14 together with the base frame 12, 13 itself provides support for module boxes. The module boxes will have downwardly projecting flanges and be held in place by these extending 20 along the frame portions. When on the trolley only module boxes belonging to the system are transported, the flanges 25, 26 will be superfluous and therefore can be omitted.

While the bracing members 16 and 14 will preferably be rectangular profile tubes, the longitudinal bracing members 18 may in the preferred embodiment be made of flat iron. At one end of the trolley, brackets 21, bearing wheels 20 with fixed orientation are welded between the side pieces 13 and the longitudinal stiffening elements 18. The wheels 20 are, in a known manner, fixed to the brackets 21 via a hub with a built-in roller bearing, axle bushing and hub cover.

At the other end of the trolley, brackets 23 are mounted between the side members 13 and 35 of the stiffening elements 18, on which respective pivotable wheels 22 are mounted. The pivot wheels are provided with ball bearings at the bracket plate 23, allowing free movement around a vertical axis. On the upper side of the console 23 there are control means, e.g. in the form of guide pins 24, whereby the position of the pivotable wheels 22 is maintained by stacking. The wheels 5 are received between the guide pins 24 and the stiffening elements 18 by stacking the trolleys as shown in FIG. Third

Between the side pieces 13 and the longitudinal stiffening elements 18, locking cross members 19 are mounted. The distance between the bracket 23 and the cross member 19 is of a size so that a wheel 22 will not be accommodated. This prevents unintentional stacking of the trolleys. By contrast, the distance between the transverse stiffening element 14 and the brackets 21 is so large that a wheel 20 on another roller 15 can easily be accommodated in the opening. When the trolleys are stacked as shown in FIG. 2, every other trolley will be displaced relative to that of FIG. 3.

Upon stacking, the wheels of the second trolley 20 will be accommodated in the opening formed between the stiffener element 20 and the bracket 21 in the bottom of the first trolley. The wheels of the second trolley 22 will extend beyond the flange 25. The stiffening elements 16 and 18 of the second trolley will be accommodated in the recesses 27 in the flange 25, whereby the bottom frames of the two trolleys will lie close to one another.

Between the longitudinal stiffening members 16 there is provided a positioning member which, in the preferred embodiment, is shaped like a V-shaped cross member 17. The cross member 17, upon stacking, bears against the inner edge of the flange 25 of the lower trolley 30, the two above mounted rollers are interlocked, the abutment of the cross member 17 against the flange 25 impeding movement in one direction and the other side of the flange 25 engaging the bracket 23, thereby preventing movement in the other direction. In addition, the hub cover will prevent transverse movement along with the stiffening elements 16, 18's inclusion in the recesses 27. Thereafter, the stacking is continued in the same way, with the wheels resting on the trolleys below. consoles. This can be seen in FIG. 2nd

To allow space for the pivot wheels, the longitudinal stiffener elements 18 are formed with bent 5 portions of material 15.

The cross member 17 may have shapes other than V-shape, e.g. it may be U-shaped, semi-circle shaped, however, a generally point-shaped contact surface against the frame or flange of the following 10 is preferable as the stacking is thereby facilitated. If the carriage bottoms have no end flanges, the cross member 17 may project below the plane of the bottom frame and grasp the end piece 12 itself. It is preferable that the cross member 17 is disposed in the center line of the carriage, but other locations may be used.

To the one end piece 12 of the trolley, a housing or sleeve 29 is welded for a locking pin or locking pawl which is not slidably accommodated in the housing 29. This locking pin can be engaged with a hole in the base, whereby the carriage is fixed. It will be appreciated that the track width between the pivotal wheels 22 may advantageously be less than the track width between the fixed wheels 20, as it is thereby achieved that the wheels 22 cannot be accommodated in the openings between the brackets 21 and the stiffener element 14. The wheels of the trolley will preferably be arranged such that the wheels 20, 22 precisely touch the end pieces 12 of the trolley when the carts are stacked as shown in FIG. 3. Thus, no displacement can occur when the carts 30 are stacked, which results in good utilization of the space in the return transport. The cross member 17 is V-shaped, giving the user a clear indication of how the trolleys should be oriented when the carts are stacked as shown in FIG. Thus, the cross member 17 serves both visual and practical purposes.

8 DK 168565 B1 In some situations it will be desirable if the carts can be stacked further compressed, which can be done by stacking the first two trolleys as previously described, while the third trolley is turned 180 ° so that the 5 rotatable wheels project beyond the trailing edge 12 of the first two trolleys. However, this requires minor structural changes, as the locking cross members must be omitted so that the wheels 20 must be accommodated in this area. Instead, the wheel brackets 23 are moved further towards the center, so that the wheels 10 22 are brought into alignment with the bracing elements 18.

In the illustrated embodiment of a trolley 10, it can be handled partly manually and partly by using a forklift, since the forks can be accommodated between the wheels 20, 22. The bottom of the trolley will be substantially flat, since the underside of the frame parts 12, 13 with advantage may be provided to align with the longitudinal stiffening members 16, 18.

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Claims (9)

9 DK 168565 B1 A trolley, preferably for transporting goods with modular dimensions, comprising a generally flat bottom frame for supporting the goods placed on the trolley, wherein the trolley has a first set of fixed wheels (20) at a first end of the bottom frame, and at least one other wheel (22) pivotally mounted at a different end of the bottom frame 10, and in addition there are supporting surfaces for another wheel of a trolley by stacking empty trolleys, the trolley base in connection with respective wheels at one end of the trolley having respective openings extending along the sides (13) for receiving respective wheels of 15 on a trolley mounted on stacker displaced in the longitudinal direction, the upper side of the bottom frame being brought into contact with the underside of the bottom frame of the trolley arranged, the bottom frame of respective wheels at the opposite end of the carriage has latches 20 (18, 19) which prevent the pickup of the wheels of other carts (22) by unintentional staggered stacking, and that on the bottom frame is provided a first positioning means (17) which, by staggered stacking, is engaged by a second positioning means (25) complementary to the first positioning means (25) on the carriage arranged above, thereby preventing longitudinal displacement of the two stacked carts. . A trolley according to claim 1, characterized in that the wheels (20, 22) are mounted on respective plate-shaped brackets (21, 23) which are fixed between the side elements (13) of the bottom frame and generally parallel longitudinal stiffening elements parallel thereto. (18). Trolley according to claim 2, characterized in that the barriers (18, 19) are provided in the form of transverse struts (19) between the side elements (13) of the bottom frame and the longitudinal stiffening elements (18). 10 DK 168565 B1 A trolley according to claims 1-3, characterized in that the fixed wheels (20) are spaced apart so that they are accommodated by staggered stacking between the side elements (13) of the bottom frame and the longitudinal stiffening elements (18). and that the flywheels (22) are less spaced apart so that the stiffening elements (18) impede their complete uptake. Trolley according to claims 1-4, characterized in that the bottom frame at its end portions (12) has upwardly extending flanges (25, 26) which are unbroken at one end of the trolley and broken at the other end for receiving the longitudinal stiffening elements ( 16, 18) on another trolley by staggered stacking. 15 A trolley according to claim 5, characterized in that the broken flange (25) constitutes the first positioning means, while the second positioning means is constituted by a bent cross member (17) disposed between two longitudinal stiffening elements (17). A trolley according to claim 6, characterized in that the bent cross member (17) is V-shaped with the tip facing the broken flange (25). 25 A trolley according to claims 1-7, characterized in that the brackets of the swivel wheels (22) are provided on the upper side with control means (24) to maintain the position of the swivel wheels (22) in stacking. 30 Trolley according to claims 1-8, characterized in that the longitudinal stiffening elements (18) between the brackets (23) of the pivotable wheels (22) and the latches are arcuate (15), so that a partial take-up of the pivotable 35 wheels (22) is allowed by stacking, with the wheels of a trolley (22) resting on the brackets (23) of a lower down trolley. -