EP1602619B1 - Device for retaining a load on the load supporting means of an industrial truck - Google Patents

Description

The invention relates to a device for holding a load on a load supporting means of a truck according to claim 1.

Forklifts, lift trucks or the like trucks have a load supporting means for receiving, transporting and depositing a load. The cargo is usually arranged on pallets, which in turn can be transported, for example by means of the forks of a truck.

High center of gravity or low weight, low footprint cargo may fall off the pallet or load support, especially when the truck is traveling over rough terrain or through bends. It is therefore also known for a long time to use so-called load holders, which press from above onto the goods to be transported, in order to drop them from the pallet or the pallet to prevent the load carrying means. Out DE 9418354 U1 or EP 467210 B1 is a holding device has become known, in which a horizontal plate arranged vertically adjustable and can be pressed by vertical lowering on the cargo. If there are several goods in the pallet of different heights on the pallet or if there are several pallets with goods of different heights on the load carrying means, a sufficient fixing of the goods to be transported fails.

It is therefore out DE 412989 C or WO 214206 A2 already known, several load holder side by side to attach to a support device. This makes it possible to clamp several juxtaposed on the load carrying goods of different heights. However, it is not possible to clamp sufficiently high transport goods, which are in the fork direction before each other, sufficiently.

Out GB 2250267 A and DE 2929621 C2 It is known to make several plates, which are mounted side by side or one behind the other, individually height-adjustable. Disadvantage of this solution is that the height differences between the individual transport goods must move within narrow limits.

Out US-A-2566863 a device for holding a load on a load supporting means of a truck has become known, in which a support structure is mounted by means of a lifting drive height adjustable above the load carrying means. The support structure has a plurality of distributed over a surface vertical guides, in each of which a punch is guided vertically. Out DD 248314 A a device for handling devices is known with movable in axial guides pins with which a gripping surface contour is adjustable. On a support structure, a clamping device is attached, with which the pins be clamped in any height in the guides. An actuator is used to selectively cause the clamp to clamp or release the pins. An actuatable by an actuator clamping unit is limited horizontally guided between a release and a clamping position. The clamping unit has clamping elements which can be brought into clamping position or rubbing with the pins in the clamping position. The clamping elements are formed by clamping jaws.

The invention has for its object to provide a device for holding a load on a load supporting means of a truck, in which the transported goods can be significantly different in height.

This object is solved by the features of patent claim 1.

In the device according to the invention, as in the prior art, a support structure guided vertically adjustable above the load carrying means on the truck. With the help of a linear actuator, the support structure can be adjusted in height. It has a plurality of vertical guides, in which punches are guided vertically over a surface which corresponds for example approximately to the surface of a pallet. If the punches are not held, they can be supported on the underlying cargo in each case. If after this process it is ensured that the punches retain this position, a secure fixing of the transported goods is achieved. The invention provides a Clamping device before, with which the stamp can be clamped in any height in the guides. An actuator worries about clamping means selectively clamping or releasing the punches in the guides. The support structure has an actuatable by the actuator clamping unit, which is guided horizontally between a release and a clamping position. The clamping unit has clamping means, which in the clamping position can be clamped or rubbed laterally into engagement with the punches. The clamping unit, which is preferably guided linearly from the support structure, can for example be operated by means of a single actuating cylinder to bring the clamping unit either in the release or in the clamping position. Instead of a double-acting actuating cylinder and a single-acting is conceivable, in the opposite direction, preferably in the direction of clamping position, a biasing spring acts.

The clamping means are friction elements, which can be brought into frictional engagement with the shaft of the stamp. As a friction element is elastic band, which is arranged horizontally and which wraps around the associated stamp partially non-positively when the clamping unit is in its clamping position.

In the invention, the larger number of punches disposed in a field approximately equal to the size of the load and lowered onto a load to reflect the irregular surface contour of the load provides for sufficient securing of the cargo on the load carrying means. All stamps are in contact with the load and can be fixed vertically. Thus, a backup of the load is given in particular against tipping over.

There are various constructive possibilities conceivable to realize the teaching described. An embodiment of the invention provides for this, that the support structure is guided in a mast of the truck and driven by a lifting cylinder, a chain drive or the like. The mast can be designed similar to a mast of a forklift. For lifting and lowering a double-acting lifting cylinder can be provided which is operated hydraulically or pneumatically. However, it can also be provided a single-acting lifting cylinder, in addition a braking device is required, which is switched on when needed to set the support structure in any position. Instead of a lifting cylinder, however, a mechanical lifting device may also be provided, for example a spindle or chain drive.

It is known to provide a stacker for a double-decker load with two load support means. The lower load support is rigidly attached to the mast of the stacker. By lifting the entire lifting device, the cargo can be lifted. On the lifting device, a load carriage is guided, on which the upper load carrying means is attached. In such a construction, the upper load carriage can be replaced by the support structure according to the invention or attached to the upper load carriage.

For the support structure different designs are conceivable. So this may have a support plate which is provided with holes in which the stamp are added. The support plate can be made for example of plastic or of a composite material. Alternatively, a welded construction can also be produced from standard profiles, whereby, for example, instead of the bores, sleeves are provided in which the punches are guided vertically.

According to a further embodiment of the invention, the stamp on the ends of a stop, which prevents slippage of the stamp down. For this purpose, e.g. Thickening of the stamp at the top serve. The punches, which preferably have circular cross-section, as well as the associated holes can be made as pipes or solid.

The clamping unit may be formed according to a further embodiment of the invention of a frame structure, which is guided horizontally linear in the support structure is. The frame structure may have a plurality of parallel spaced U-profiles, the web has slots through which the stamp are passed and in which the clamping means are associated with the slots which are attached to the legs of the U-profiles, for example in the form of the aforementioned elastic bands.

The actuation of the lifting drive and the actuating device is controlled according to a further embodiment of the invention by a control device. For this purpose, a further embodiment of the invention provides that the control device controls the clamping device in the release position when the support structure is moved and controls in the clamping position when the support structure is at a standstill. As a result, the actuation of the holding device is carried out largely automatically.

A timed even more coordinated control of the holding device according to the invention allows a further embodiment of the invention, according to the first sensors are associated with the punches, which determine when a stamp has been adjusted by a maximum distance from the support structure upwards. The control device terminates the lowering operation of the support structure when it receives a first sensor signal. The support structure can not be lowered further in this case, as they would otherwise damage the cargo. For very large height differences, however, not all stamps are engaged in this state yet. Thus, the sensor signal marks the later possible, but not necessarily the time-optimal shutdown time.

A further control possibility results according to the invention, when connected to the support structure with the control device second sensors are provided which emit a second sensor signal when a punch reaches a maximum lower position. The control device stops the lowering movement of the support structure when all the punches are raised from the lowest position. This sensor circuit serves to terminate the lowering movement at the earliest possible time. It thus saves time.

The sensors may be formed, for example, by providing electrical contacts on the support structure which cooperate with contact surfaces on the punches.

The lower end of the stamp is preferably widened in order to have better security and to prevent damage to the cargo. In any case, it is advantageous if the lower end face of the punches have a coating or the like with a high coefficient of friction.

Fig. 1

zeigt die Seitenansicht eines Flurförderzeugs mit einer Vorrichtung nach der Erfindung.

Fig. 2

zeigt die Draufsicht auf die Darstellung nach Fig. 1.

Fig. 3

zeigt die Vorderansicht des Flurförderzeugs nach Fig. 1 mit der erfindungsgemäßen Vorrichtung.

Fig. 4

zeigt die Einzelheit 4 in Fig. 2.

Fig. 5

zeigt einen Schnitt durch die Darstellung nach Fig. 4 entlang der Linie 5-5.

Fig. 6

zeigt schematisch die Unterseite der Tragplatte nach der erfindungsgemäßen Vorrichtung.

The invention will be explained in more detail with reference to an embodiment shown in the drawings.

Fig. 1

shows the side view of a truck with a device according to the invention.

Fig. 2

shows the top view on the representation Fig. 1 ,

Fig. 3

shows the front view of the truck Fig. 1 with the device according to the invention.

Fig. 4

shows the detail 4 in Fig. 2 ,

Fig. 5

shows a section through the illustration Fig. 4 along the line 5-5.

Fig. 6

schematically shows the underside of the support plate according to the device according to the invention.

In the FIGS. 1 to 3 is an electric pedestrian pallet truck 1 to recognize with a fork carriage, the three forks 3 (see Fig. 3 ), which are provided at the front with support rollers 20, against which the tines 3 can be lifted hydraulically, as is generally known. As can be seen, a plurality of rolling pallets 4 are received in the longitudinal direction one behind the other on the forks 3.

On lifting truck 1, a mast 2 is attached to which a support plate 6 is guided vertically movable. The lifting and lowering movement of the support plate 6 causes a double-acting lifting cylinder 16 (FIG. FIGS. 2 and 3 ). Instead of a pneumatic or hydraulic lifting cylinder and other mechanical lifting devices are conceivable, for example, a spindle or chain drive. The lift cylinder may also be single-acting, requiring a brake device that is engaged to fix the support plate in its respective position. At sufficiently high weight of the load-holding device may possibly be dispensed with a braking device.

The support plate 6 is shown as a solid plate made of plastic or a composite material. Instead of a solid support plate and a welded construction can be provided from standard profiles.

In the support plate 6 are holes 22 in which punch 8 can move vertically. How out Fig. 6 shows, are located on the underside of the support plate 6 on opposite sides of the holes contact elements 24, which are not shown for all holes. They are connected to a battery 26. All pairs of contact elements 24 are connected in series.

In the illustrated embodiment, 4 x 6 holes 22 are arranged at a uniform distance from each other, which corresponds to a field that can be occupied by the load supporting means or the transportable on the load carrying means. Thus, 24 punches 8 are provided. The thickness of the support plate 6 is sufficient to ensure proper guidance in the holes 22. It is also conceivable to use additional sleeves or sleeves in welding constructions for guidance alone in order to ensure frictionless guidance of the punches 8.

On the support plate 6 rests a clamping unit 7, which is designed as a frame construction with four parallel spaced U-profiles 26, which are welded together by two transverse U-profiles 28. On the plate 6 there are two parallel strips 15, through which the clamping unit 7 linear along the axis of the truck is guided. On the support plate 6, an actuating cylinder 14 is articulated, which engages with its piston rod on a transverse strut 28. On the opposite side of the cylinder 14, a spring 12 is arranged, which is supported on the one hand on the transverse profile 28 and on the other to an abutment 13 on the plate 6. Instead of the spring 12, however, the actuating cylinder 14 may also be double-acting.

As it turned out 4 and 5 shows, the webs of the U-profiles 26 slots 30, which are aligned with the bores 22 of the support plate 6. The punches 8 are also passed through the elongated holes 30. In the region of the elongated holes 30, an inner side of the legs of the U-profiles 7 is in each case arranged a bow-shaped holder 17 for an elastic band 18. Is the stamp 8 in the in Fig. 4 shown position, it is partially wrapped by the elastic band 11.

In Fig. 5 is also a contact element pair 24 can be seen. At the lower end of the punch 8 a larger diameter Reibauflage 10 is mounted and between friction pad 10 and punch 8 an electrically conductive material 19. If the punch 8 is moved upwardly at maximum, passes the conductive material 19 with the contact element pair 24 into engagement.

1. 1. Aufsetzen der gezeigten Lasthaltevorrichtung auf einer Last am Aufnahmepunkt
2. 2. Halten der Lasthaltevorrichtung auf der Last während des Transports
3. 3. Abheben der Lasthaltevorrichtung am Absetzpunkt der Last
   An dem Punkt, an dem die Rollpaletten 4 mit der darauf befindlichen Last 5 aufgenommen werden sollen, fährt der Bediener den Hubwagen 1 mit den Gabelzinken 3 unter sechs in Blocklagerung am Boden gelagerte Rollpaletten 4. Die Gabelzinken 3 befinden sich in ihrer untersten Position. Die Tragplatte 6 mit der Klemmeinheit 7 befindet sich in der obersten Position, in der alle Stempel 8 mit ihrer Verdickung 9 an den Stegen der U-Profile 26 anliegen. Die Stempel 8 ragen mit ihrer maximal verfügbaren Länge nach unten aus der Tragplatte 6 hervor.
4. 4. Bei der Verwendung eines Hubwagens für die Doppelstockbeladung sollte die Abfolge der Funktionen wie folgt sein:
   1. a) Der Bediener fährt mit den Gabeln unter die Rollpaletten
   2. b) Verspannungsvorrichtung wird gelöst
   3. c) Tragplatte wird abgesenkt
   4. d) Stempel geraten in Eingriff und werden wieder verspannt
   5. e) Die unteren Gabeln mit den Rollpaletten werden mitsamt dem Hubgerüst und der Tragplatte angehoben.

The in the FIGS. 1 to 6 The device shown operates as follows. The transport of cargo by means of the lift truck 1 is divided into three sub-functions:

1. 1. placing the load holding device shown on a load at the pickup point
2. 2. Hold the load holding device on the load during transport
3. 3. Lifting the load holding device at the set point of the load
   At the point where the rolling pallets 4 are to be received with the load 5 thereon, the operator drives the lift truck 1 with the forks 3 under six stored in block storage on the ground rolling pallets 4. The forks 3 are in their lowest position. The support plate 6 with the clamping unit 7 is in the uppermost position, in which all the stamp 8 with its thickening 9 on the webs of U-profiles 26 abut. The stamp 8 protrude with their maximum available length down from the support plate 6.
4. 4. When using a double-deck lift truck, the sequence of functions should be as follows:
   1. a) The operator drives with the forks under the rolling pallets
   2. b) bracing device is released
   3. c) support plate is lowered
   4. d) Stamps engage and are tightened again
   5. e) The lower forks with the rolling pallets are lifted together with the mast and the support plate.

This order ensures that you can not overturn when lifting the pallets.

If the operator actuates the lifting device for the forks 3, the rolling pallets 4 are lifted off the ground and rest on the forks 3. At the same time, the single-acting hydraulic cylinder 14 is actuated and shifts the clamping unit 7 against the force of the spring 14 from the truck 1 away. As a result, the elastic bands 11 move away from the punches 8, and the punches 8 are free to move vertically. Simultaneously, the double-acting hydraulic cylinder 16 moves the support plate 6 in the mast 2 down. The simultaneity of the three operations described is realized by means of a control device, not shown, which may be designed so that no manual operations have to be performed by the operator.

By lowering the support plate 6, the stamp come 8 with their Reibauflagen 10 on the top of the load 5 to lie. Since the punches in the bores 22 and 30 are free to move, they slide up through the support plate. The deeper the support plate 6 is lowered, the more punch 8 come to rest on the different height levels of the load 5.

The described lowering of the support plate 6 must be terminated automatically when at least one of the punch 8 has been pushed upwards through the bore 22. The metal support 19 then comes into contact with the contact element pair 24. As it turned out Fig. 6 results, thereby a current flow is effected, for example, can be displayed in the instrument 32 and can be used to end the operation of the lifting cylinder 16. When using a double-acting lifting cylinder for the support plate 6 is preferably a pressure relief valve (not shown) to provide for the downward movement in order to avoid injury to persons or damage to the cargo.

In addition to the described termination of the lowering operation, which indicates the latest possible time, a time saving can be achieved by introducing a second condition. As soon as all the punches 8 have come to rest on the load, their extensions 9 are released from the clamping unit 7, since the punches 8 begin to push through the bores 22 and 30. This can be sensed by the same principle as described for the contact pair elements 24 and the contact pad 19. Thus, contact surfaces can be provided on the lower side of the extension 9, which cooperate with upper contact pairs (not shown) on the webs of the U-profiles 26. The lowering movement of the support plate 6 is terminated when the contact between these contact pairs and the contact surfaces is interrupted for all stamp.

When the lowering movement of the support plate 6 is completed, the actuating cylinder 14 is relaxed by the control device. As a result, the spring 12 presses the clamping unit 7 in the direction of lifting truck, which causes the elastic bands 11 are pressed against the punch 8. This creates a frictional engagement between the punch and elastic band 14, which inhibits vertical movement of the punch 8. The punch 8 is therefore located with its Reibauflage 10 on the load 5 and is fixed in its vertical movement. Since rest on the entire height contour of the load 5 stamp 8, which are not vertically movable, the load is positively against tipping and by means of the Reibauflage 10 frictionally secured against slipping.

Arrived at the set point, the operator actuates the lowering movement for the forks 3. As a result, the rolling pallets 4 are placed on the ground. At the same time, the following two operations are performed by the control device described above:

The actuating cylinder 14 is pressurized, so that the clamping unit 7 is pressed against the force of the spring 17 in the direction of the fork tines. As a result, the elastic bands 11 are relieved and the frictional engagement of the punch 8 is canceled. As a result, the stamps in their guides are free to move again.

On the other hand, the double-acting lifting cylinder 16 moves the support plate 6 upwards. Since the punches 8 are vertically freely movable, they slide through the holes 22 to its extension 9 on the clamping unit 7 from. When the double-acting lifting cylinder 16 has reached its uppermost position, the actuating cylinder 14 is relieved and the punch 8 are clamped again by means of the elastic bands 11.

In this position, the load is no longer fixed, and the operator can go back with the truck.

Claims (17)

1. Device for holding a load (5) on a load support (3) of an industrial truck having a support construction, adjustable in its height by a lifting drive, is mounted above the load support wherein the support construction has several vertical guidances, distributed across a plane, in each of which one plunger (8) is vertically guided, characterised in that a clamping device is attached on the support construction, by means of which the plungers (8) are fixable in the guidances in an arbitrary height position, that an actuation device for the clamping device for optional clamping or releasing the plungers (8) in their guidances is provided, wherein a clamping unit, operable by the actuation device, movable in a limited path between a release position and a clamping position and the clamping unit has frictional elements in form of an elastic, horizontally arranged ribbon (11), which partly non-positively loops around the respective plunger (8) in the clamping position and in the clamping position can be brought into clamping or frictional lateral engagement, respectively, with the plungers (8).
2. Device according to claim 1, characterised in that the support construction is guided in a lifting scaffold (2) of the industrial truck (1) and is driven by a lifting plunger (16), a chain drive or the like.
3. Device according to claim 1 or 2, characterised in that the vertical guidances are formed by sleeves or bores (22) in the support construction.
4. Device according to claim 3, characterised in that the support construction has a support plate (6).
5. Device according to any one of claims 1 to 4, characterised in that the plungers (8) have a stop on the upper ends, which prevents any slipping of the plungers (8) towards the downside.
6. Device according to any one of claims 1 to 5, characterised in that the actuation device has an actuation cylinder (14).
7. Device according to claim 6, characterised in that the actuation cylinder (14) is single-acting and a pretension spring (12) preloads the clamping unit into the clamping position.
8. Device according to any one of claims 1 to 7, characterised in that the clamping unit has a frame construction, which is linearly horizontally guided on the support construction.
9. Device according to claim 8, characterised in that the clamping unit has several parallel spaced apart U-profiles (26), the bridge of which has long holes (30) through which plungers (8) are guided through, and the elastic ribbons (11) are assigned to those long holes (30) which are made on the limbs of the U-profiles (26).
10. Device according to any one of claims 1 to 9, characterised in that the lifting drive and the actuation device are controlled by a controlling device.
11. Device according to claim 10, characterised in that the controlling device controls the clamping unit into the release position when the support construction is moved and that it controls into the clamping position when the support construction is in the idle condition.
12. Device according to claim 10 or 11, characterised in that first sensors are assigned to the plungers (8), which determine whether a plunger (8) has been shifted towards the upside about a predetermined path with respect to the support construction, an that the controlling device stops the lowering movement of the support construction, when it receives a first sensor signal.
13. Device according to claim 12, characterised in that contacts (24), connected to the controlling device, are attached on the support construction, which co-operate with a contact surface (19) on the bottom end of the plungers (8).
14. Device according to any one of claims 10 to 13, characterised in that second sensors, connected to the controlling device, are provided on the support construction, which emit a second sensor signal when a plunger (8) reaches a predetermined lower position and that the controlling device stops the lowering movement of the support construction, when all the plungers (8) are lifted with respect to the undermost position.
15. Device according to claim 14, characterised in that second contact elements, connected to the controlling device, are provided on the support construction, and that second contact surfaces are provided on the upper end of the plungers (8), which co-operate with the second contact elements when the plungers are in the lower position.
16. Device according to any one of claims 1 to 15, characterised in that the plungers (8) have an enlargement (9) on the upper end.
17. Device according to any one of claims 1 to 16, characterised in that disks (10) are mounted on the lower end of the plungers (8), the bottom sides of which have a high frictional value.

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