EP4051621B1 - Drive device - Google Patents

Description

The invention relates to a drive device, in particular for a device for receiving and transporting loads, which is attached or is to be attached to another device. This other device can be a stationary or movable device, whereby the movable device can be, for example, a vertically movable lifting carriage of an industrial truck.

Such devices for picking up loads can, for example, be integrated into an industrial truck or designed as an attachment that is attached or is to be attached to a device such as a forklift truck. They usually have two or more load-carrying elements that can move relative to one another and, for example, can have the form of two fork tines that can move relative to one another. This mobility of the fork tines is achieved by appropriately designed adjustment devices and enables users to adapt the fork tines to the width of an object to be picked up or to recesses in it into which the fork tines engage.

In many cases, the load-handling elements can not only be moved towards and away from each other, but also both can be moved parallel and simultaneously in the same direction in order to compensate for an inaccurate approach with the industrial truck without having to maneuver the entire vehicle. This sideshift movement is made possible by the same drive units as the movement of load-handling elements towards and away from each other. The respective adjustment devices are operated by the operator of the industrial truck from the workplace without him having to get off.

Since such load-bearing devices are usually used intensively in relatively harsh environments, the robustness of the construction is an important requirement criterion. The load to be carried always comes directly with the device in contact and protruding parts of the load or picking up the load too roughly can lead to damage.

From the German disclosure document EN 10 2011 002 433 (A1 ) a device for transporting loads is known which comprises two load-bearing elements, each of which is attached to horizontally movable sliding arms which can be moved relative to one another by drive elements, wherein the sliding arms are mounted on at least one sliding guide body and can be moved along a sliding guide body by the drive elements. The load-bearing elements are additionally each attached to movable guide arms which are guided on a guide rail, wherein the sliding guide body and the guide rail are connected to one another by two connecting elements and spaced apart from one another. The drive elements are partially arranged inside the sliding guide body and the sliding arms are movably guided within the sliding guide body, wherein the sliding guide body has a longitudinal slot through which a connecting section of the sliding arm protrudes from the sliding guide body and is connected to a load-bearing element. When the device is in operation, the largest part of the respective drive element lies within the sliding guide body. The sliding guide body thus at least partially encompasses both the drive elements and the sliding arms, so that these are advantageously protected in a sliding guide body, which also serves to guide the sliding arms. Damage and failure of the industrial truck can thus be reduced and maintenance costs remain low. At the same time, the device can be designed to be compact, thus ensuring a good view from the operator to the load-handling elements and can be manufactured inexpensively. The disadvantage of this design is that two sliding guide bodies lie on top of each other and, despite the compactness of the design, still limit the free cross-section for an industrial truck operator to see through the device. The higher weight of this design is also a disadvantage.

From the international patent application WO 2016 / 205 376 A1 A fork positioning arrangement for mounting on a lift truck is known. The device comprises a first fork positioner and a second fork positioner, the fork positioners being connected to a fork frame. The The first fork positioner is constructed substantially as a mirror image of the second fork positioner. Each fork positioner comprises a tube having an internal cavity in which a piston and a carrier are arranged, both coupled to a rod. The piston and the carrier are both in sliding contact with the tube. Each fork positioner has a fork holder arranged outside the tube, the fork holder being coupled to the carrier through a slot in the tube. The part of the carrier coupled to the fork holder is located between a first carrier bushing and a second carrier bushing. The fork frame makes the fork positioning arrangement quite large, reducing the free cross-section between the fork positioners and thus the visibility for an operator of an industrial truck to which the fork positioning arrangement is attached.

From the German disclosure document DE10 2017 213 236 A1 A device for picking up and transporting loads, which can be attached to a moving or stationary device, is known. A first guide profile element has a hollow profile element, wherein a drive element is at least partially integrated in the interior of the first guide profile element. The drive element and the guide of a driver plate for a fork tine are on one axis. With this embodiment, a large view cross-section is already achieved. However, drive elements available on the market also impair the operator's view cross-section in this embodiment.

From the Japanese utility model JP H02 147 486 U a drive device for the lateral movement of at least two load-bearing elements of a device for receiving and transporting loads for mounting on a movable or stationary device according to the preamble of claim 1 is known, comprising a first

Drive element and a second drive element, wherein a first load-bearing element is movable laterally in the axial direction of a first guide profile of the device for receiving and transporting loads by the first drive element and a second load-bearing element is movable laterally in the axial direction of a first guide profile of the device for receiving and transporting loads, wherein the at least two load-bearing elements are supported by the first guide profile, wherein the two drive elements are connected by exactly one drive unit, with exactly one drive unit being positioned between the two drive elements. This drive device also does not solve the problems described above.

The object of the invention is therefore to provide a drive device for a lateral movement of load-carrying elements, which can be connected to a device for receiving and transporting loads and with which the free cross-section for the view through of an operator of the device for receiving and transporting loads is further maximized.

According to the invention, this object is achieved by a drive device having the features of independent claim 1. Advantageous further developments of the drive device emerge from subclaims 2 to 10.

An inventive drive device for the lateral movement of at least two load-bearing elements of a device for receiving and transporting loads for mounting on a movable or stationary device has a first drive element and a second drive element, wherein a first load-bearing element can be moved laterally in the axial direction of a first guide profile of the device for receiving and transporting loads by the first drive element and a second load-bearing element can be moved laterally by the second drive element. The at least two load-bearing elements can be carried by the first guide profile. The two drive elements can be driven by exactly one drive unit, wherein exactly one drive unit is positioned between the two drive elements. Since the load-bearing elements can be driven by the drive elements, in other words the drive unit is also arranged between the load-bearing elements. The exactly one drive unit has an internal and continuous output shaft, wherein the first output shaft end is operatively connected in a rotationally fixed manner to the first drive element and the second output shaft end is operatively connected in a rotationally fixed manner to the second drive element, and the axis of the output shaft and the axes of the drive elements lie on one line. According to the invention, the first guide profile has a hollow profile, a drive element is at least partially integrated in the interior of the first guide profile and, in addition, exactly one drive unit is at least partially integrated in the interior of the first guide profile.

The connection of the output shaft with the two drive elements can This can be done, for example, in the middle of the output shaft. Because the axis of the output shaft and the axes of the drive elements are in line, makes the drive device particularly compact. The axes of the drive elements can also be offset from one another. For example, one drive element can be operatively connected to a gear wheel. This embodiment can be advantageous for special applications.

In this document, a drive unit is understood to be a unit that is capable of driving the drive elements. The drive unit can have a motor and possibly other components, such as bearings, gears, etc. The motor can be a hydraulic motor or an electric motor, for example.

In this document, a lateral movement of the load-bearing elements is understood to mean a movement of the load-bearing elements towards or away from each other, i.e. in a direction transverse to a load-bearing or load-transport direction, as well as the parallel movement of the load-bearing elements transverse to a load-bearing direction. The load-bearing elements can usually be fastened to a first guide profile, with this first guide profile being arranged transversely to the transport and bearing direction of the loads and the lateral direction pointing in the direction of the first guide profile.

Since the two drive elements can only be driven by exactly one drive unit, the drive device is particularly compact.

In a further advantageous embodiment, at least one drive element has a spindle. Alternatively, each drive element has a spindle with a different direction of rotation.

In a further advantageous embodiment, each of the two drive elements has a double spindle with a different direction of rotation.

In a further advantageous embodiment, each drive element can be operatively connected to at least one load-bearing element. The operative connection can, for example, have a direct connection between the drive element and the at least one load-bearing element. However, it is also possible for the operative connection to be made, for example, via an adapter piece in the form of for example, a carrier plate. The load-bearing elements can be easily inserted into the carrier plates, so that the standard load-bearing elements such as standard forks, which can still perform lateral movements.

Furthermore, it has proven to be advantageous if the first guide profile has a hollow profile and a drive element is at least partially integrated in the interior of the first guide profile, wherein the first guide profile has a longitudinal slot through which a holder for a load-bearing element protrudes. Due to the at least partial integration of the drive element in the hollow profile, the drive element is protected against external influences and thus against damage.

In addition to a drive element, the exact one drive unit is at least partially inside the first Guide profile integrated. Due to the at least partial integration of the drive unit into the hollow profile, the drive unit is protected against external influences and thus against damage.

In a further advantageous embodiment, the one drive unit has a gear, the gear being drivable and the gear being rotationally fixedly connected to the output shaft. This design makes the one drive unit very compact, which further maximizes the free cross-section for the operator of the device for picking up and transporting loads to see through.

In an advantageous embodiment, at least one drive element has a spindle. Ball screws or threaded spindles can be used, for example. A bushing can serve as a counterpart to the spindle, to which a connecting element can be attached for connection to a load-bearing element.

In a further advantageous embodiment, at least one drive element has a switchable gear for reversing the direction of movement of at least one load-handling element. This makes it possible for the lateral movement of the load-handling elements to run in the same or opposite directions depending on the position of the gear. The opposing mobility of the forks enables users to adjust the distance between the load-handling elements to the width of an object to be picked up or to recesses in it into which the load-handling elements can engage. The parallel movement of the load-handling elements in the same direction enables an imprecise approach with an industrial truck to a load to be picked up, whereby the parallel movement of the load-handling elements in the same direction enables the load to be picked up without maneuvering the entire vehicle.

In an advantageous embodiment, bearings are provided in the drive device which are designed to absorb lateral forces of the drive elements. The lateral forces of the drive elements can arise from the side thrust movement and consist, for example, of inertial forces of the moving masses, friction and possible forces caused by the lateral displacement of loads with a load-bearing element. By providing the bearings, such forces can be absorbed without putting strain on gears or other components of the drive unit. The bearings can be provided at the respective ends of the drive elements.

It has also proven to be advantageous if the drive unit has a housing, whereby axial forces of the drive elements can be transferred via the housing to the device for receiving and transporting loads. The load can be transferred from the drive elements to the housing, for example, via the bearings described above. The loads can be transferred via the housing to the overall structure, for example via a frame or other structural elements, without loading movable functional elements of the drive device. Axial loads can arise, for example, if the load-bearing elements are loaded laterally during transport or receiving of loads.

In a further advantageous embodiment, the drive device has at least a first connecting element and a second connecting element for receiving the at least two load-bearing elements, wherein the first connecting element can be operatively connected to a first bushing and the second connecting element to a second bushing with internal threads, wherein the first bushing is operatively connected to the first drive element and the second bushing to the second drive element, wherein the drive elements each have an end stop, wherein a spring is provided between the bushings and the respective end stop. The connecting elements are moved laterally via bushings, for example by rotating the drive elements, wherein the lateral movement can take place in the opposite or the same direction. The spring prevents the drive element from getting stuck in the bushing at the end stop. When the bushing running on the spindle approaches an end stop, the spring is initially subjected to pressure. The counterforce built up by the spring slowly increases as the bushing advances further on the spindle, so that the bushing on the spindle does not suddenly block and thereby create a high tension force in the thread of the spindle. In addition, the release force required later when turning the Sindel back to release the bushing supported by the spring. In other words, the spring acts as a force accumulator. The spring can be arranged at the end stop on the spindle or in the bushing.

In one embodiment, at least one spring is installed for each direction of movement. If one spring is installed in opposite directions for each direction of movement and provided with even a slight offset so that both springs cannot be brought to a stop at the same time, only one spring brakes in each direction. Since the output shaft in the drive unit, which is connected to the anti-vibration elements in a rotationally fixed manner, is continuous, the entire anti-vibration shaft and both drive elements brake. This means that one spring can be saved for each direction of movement, which means that the drive device takes up less space and is inexpensive to manufacture. All known suitable springs can be used as springs, such as helical, disc, evolute, ring, gas pressure, rubber or air springs.

It has also proven to be advantageous to arrange the spring in a chamber in the bushing. This prevents the spring from moving when loaded. In addition, the range of motion of the load-bearing elements is maximized.

The drive unit can, for example, have a hydraulic motor. A hydraulic fluid flows under pressure into a chamber in which the two gears are arranged to rotate and mesh with one another. The gears are arranged in the chamber in a similar way to a gear pump in such a way that they can rotate in the chamber housing with little play. The hydraulic fluid presses on two gear flanks in the direction of rotation and one gear flank against the direction of rotation. The hydraulic fluid is guided to the drain side in chambers that are formed between the tooth flanks and the housing wall. This means that such a hydraulic motor is very compact, so that the free cross-section for an operator to see through the device for picking up and transporting loads is further maximized. The use of a hydraulic motor is particularly advantageous when using the drive unit on an industrial truck, since industrial trucks are usually designed to drive additional actuators. have a hydraulic unit so that pressurized hydraulic fluid is available on the industrial truck as standard.

It has proven to be advantageous if the hydraulic motor has a connection for the supply and return of the hydraulic fluid, with the connections facing the same side of the hydraulic motor. This also allows the connecting lines to be laid in such a way that the visibility of the operator of the device for picking up and transporting loads is not restricted.

Alternatively, the drive unit can have an electric motor. The electric motor does not require any connections for the supply and return of the hydraulic fluid, which means that the operator's visibility of the device for picking up and transporting loads is even less restricted.

It has also proven to be advantageous if the first guide profile has a receiving profile with a protruding strip on one of its outer sides, wherein the at least one load-bearing element can be suspended in the receiving profile by means of a suspension profile that is a mirror image of the receiving profile, wherein the suspension profile has a sliding piece that rests on the protruding strip of the receiving profile when the load-bearing element is suspended in the receiving profile. The load-bearing elements can be suspended on the upper guide profile, wherein they are carried by the upper guide profile and supported by the lower guide profile. The sliding piece minimizes friction during the lateral adjustment of the load-bearing element, whereby less energy is required for the lateral adjustment of the load-bearing element and wear is minimized.

It has proven to be particularly advantageous if only one guide profile has a drive element.

Furthermore, it has proven to be advantageous if at least the first guide profile encompasses the drive element arranged inside it by more than half. Furthermore, it has proven to be particularly advantageous if the degree of encirclement is more than 75%. By encircling the drive element by the guide profile, the drive element is protected in the guide profile and is held by it in such a way that it cannot bend or buckle even when great force is applied.

Further advantages, special features and expedient developments of the invention emerge from the subclaims and the following presentation of preferred embodiments with reference to the figures.

• Fig. 1 dreidimensionlae Darstellung einer nicht beanspruchten Antriebsvorrichtung mit Lastaufnahmelementen in maximaler Weitstellung
• Fig. 2 dreidimensionlae Darstellung einer nicht beanspruchten Antriebsvorrichtung mit Lastaufnahmelementen in maximaler Engstellung
• Fig. 3 dreidimensionale Darstellung einer nicht beanspruchten Antriebsvorrichtung mit Verbindungselementen in maximaler Weitstellung
• Fig. 4 dreidimensionlae Darstellung einer erfindungsgemäßen Antriebsvorrichtung mit Lastaufnahmelementen in einer Zwischenstellung
• Fig. 5 dreidimensionlae Darstellung einer erfindungsgemäßen Antriebsvorrichtung im Schnitt
• Fig. 6 Draufsicht einer erfindungsgemäßen Antriebsvorrichtung im Schnitt

From the pictures shows:

• Fig.1 three-dimensional representation of a non-stressed drive device with load-bearing elements in maximum wide position
• Fig.2 three-dimensional representation of a non-stressed drive device with load-bearing elements in maximum narrow position
• Fig.3 three-dimensional representation of a non-stressed drive device with connecting elements in maximum wide position
• Fig.4 three-dimensional representation of a drive device according to the invention with load-bearing elements in an intermediate position
• Fig.5 three-dimensional representation of a drive device according to the invention in section
• Fig.6 Top view of a drive device according to the invention in section

Fig.1 shows a three-dimensional representation of a non-claimed drive device 100 with load-bearing elements 191, 192 inserted into connecting elements 125, 136. The first and the second drive element are located in one plane and in this embodiment below a first guide profile 120 (in Fig.1 not shown, see Fig.4 , 5 and 6 )) or a fork carrier bar 124 to which the drive device 100 is attached. Alternatively, the drive device can also be arranged above the first guide profile 120. Furthermore, the drive device can also be integrated in the lifting frame (not shown) of an industrial truck by connecting the mast cheeks of the industrial truck (not shown) directly to the frame construction, which means that a fork carrier bar can be dispensed with. The load-bearing elements 191, 192 are are suspended from the first guide element 120 and are supported by it. The load-bearing elements 191, 192 are also supported by a second guide profile 140. Between the first drive element 121 and the second drive element 131 there is a drive unit 160 in a housing 165. This drive unit 160 can be, for example, an electric motor or a fluid motor, for example a hydraulic motor. The drive unit 160 drives both the first drive element 121 and the second drive element 131, which are located on a continuous shaft, in a rotational manner. Spindles, for example recirculating ball spindles or threaded spindles, are installed as drive elements 121, 131. Bushings 121 h, 131 h, to which connecting elements 125, 135 are attached, are moved via the drive elements 121, 131. Gears can be integrated in the drive elements 121, 131 (not shown in the figure), which can be switched and can reverse the direction of rotation of a drive element 121, 131, so that both a side-shift movement, in which the connecting elements 125, 135 are moved parallel and in the same direction, and an opposite movement of the connecting elements 125, 135, as is necessary for adjusting the distance between the load-bearing elements 191, 192, is possible. In Fig.1 the connecting elements 125, 135 and thus the load-bearing elements 191, 192 are in the maximum wide position.

In Fig.2 the drive device 100 is from the Fig.1 shown in the maximum narrow position. The two connecting elements 125, 135 are moved up to a stop (not shown) on the drive unit 160.

Fig.3 shows a non-claimed drive device 100 with connecting elements 125, 135 in the maximum wide position in a three-dimensional representation detached from an assembly situation. The connecting elements 125, 135 are attached to the bushings 121h, 131h driven by the drive elements 121, 131. The drive unit 160 is arranged centrally between the bushings 121h, 131h.

Fig.4 shows a further three-dimensional representation of a drive device 100 with connecting elements 125, 135 load-bearing elements in an intermediate position. The drive elements 121, 131 are integrated into the first guide element 120, which is designed as a hollow profile, and are therefore not visible in this representation. By integrating them into the first guide profile 120, the drive elements 121, 131 are largely protected against damage. The Drive unit 160 of this embodiment has a hydraulic motor. The hydraulic connections 200 point upwards out of the first guide profile 120 through openings in the housing 165, so that the hydraulic connections 200 and hydraulic hoses attached thereto (not shown) do not interfere with the load pickup and the clear view for an operator of a device for picking up and transporting loads on which the drive device is mounted is not restricted.

Fig.5 time a three-dimensional representation of a drive device 100 in section. Bearings 162 are provided in the drive unit 160 and are designed to absorb lateral forces of the drive elements 121, 131. The lateral forces of the drive elements 121, 131 can arise from the side-shift movement and are composed, for example, of inertial forces of the moving masses, friction and possible forces from the lateral displacement of loads with a load-bearing element 191, 192. By providing the bearings 162, such forces can be absorbed. The drive unit 160 has a housing 165, wherein axial forces of the drive elements 121, 131 can be transferred via the housing 165 to the device for receiving and transporting loads, on which the drive device 100 is mounted. The first connecting element 121 has a first bushing 121h and the second connecting element 131 has a second bushing 131h with an internal thread, the first bushing 121h being operatively connected to the first drive element 121 and the second bushing 131h being operatively connected to the second drive element 131, the drive elements 121, 131 each having an end stop 300, a spring 400 being provided between the bushings 121h, 131h and the respective end stop 300. Connecting elements 125, 135 can be fastened to the bushings 121h, 131h and can be moved laterally, for example by rotating the drive elements 121, 131 via the bushings 121h, 131h, the lateral movement being able to take place in the same or opposite direction. The spring 400 prevents the respective drive element i121, 131 from getting stuck in the respective bushing 121h, 131h at the end stop 300. If the bushing 121h, 131h running on the respective spindle 121i, 131i approaches an end stop 300, the spring 400 is initially subjected to pressure. The counterforce built up by the spring 400 slowly increases as the respective bushing 121h, 131h advances further on the respective Spindle 121i, 131i, so that the bushing 121h, 131h on the spindle 121i, 131i does not suddenly block and thereby create a high tension force in the thread of the spindle 121i, 131i. In addition, the release force required later when turning back the spindle 121i, 131i to release the bushing 121h, 131h is supported by the spring 400. In other words, the spring 400 acts here as a force accumulator. The spring 400 can be arranged on the end stop 300 on the spindle 121i, 131i and/or partially in the bushing 121h, 131h. In the embodiment shown in the figure, the spring 400 in the first drive element 121 is arranged on the spindle 121i such that it can engage between the anti-roll element 160 and the bushing 121h, while the spring 400 in the second drive element 131 is arranged in the bushing 131h such that it can engage between the bushing 131h and the release stop 300.

Fig.6 shows an embodiment of the drive device 100 from Fig.5 in a top view in section. The anti-vibration unit 160 has a gear 161 on an output shaft 170, via which the output shaft 170 can be driven. The output shaft 170 has a first output shaft end 171, via which the output shaft 170 is connected in a rotationally fixed manner to the first drive element 121. The output shaft 170 also has a second output shaft end 172, via which the output shaft 170 is connected in a rotationally fixed manner to the second drive element 131. The drive unit 160 has two bearings 162, via which lateral forces introduced by the drive elements 121, 131 are absorbed via the housing 165, without the gear 161 or other components of the drive unit 160 being loaded. One spring 400 is installed for each direction of movement. Each of these springs 400 is installed in opposite directions and is offset only slightly so that both springs 400 cannot be brought to a stop at the same time. As a result, only one spring 400 brakes in each direction. Since the output shaft 170 is continuous in the drive unit 160, the entire output shaft 170 and thus the two drive elements 121, 131 brake when a stop 300 is approached in each direction of movement. Coil springs are used as springs 400 in the embodiment shown. In principle, all known suitable springs 400 can be used, such as coil, disc, evolute, ring, gas pressure, rubber or air springs.

List of reference symbols:

100

Drive device

120

first leadership profile

121

first drive element

121 hours

first socket

121 i

first spindle

124

Fork carrier bar

125

first connecting element

131

second drive element

131 hours

second socket

131 i

second spindle

135

second connecting element

160

Drive unit

161

gear

162

camp

165

Housing

170

Output shaft

171

first output shaft end

172

second output shaft end

191

first load-bearing element, first fork

192

second load-bearing element, second fork

200

Hydraulic connection

300

End stop

400

Feather

Claims (10)

1. A drive unit (100) for lateral movement of at least two load-bearing elements (191, 192) of a device for receiving and transporting loads for assembly on a movable or stationary device, having a first drive element (121) and a second drive element (131), whereby a first load-bearing element (191) can be moved laterally through the first drive element (121) and a second load-bearing element (192) through the second drive element (131) of a first guide profile (120) of the device for mounting and transport of loads, whereby at least two load-bearing elements (191, 192) can be supported by the first guide profile (120), whereby the two drive elements (121, 131) can be driven by exactly one drive unit (160), whereby the exactly one drive unit (160) is positioned between the two drive elements (121, 131), whereby the exactly one drive unit (160) has an internal continuous driveshaft (170), whereby the first end of the driveshaft (171) is non-rotatably connected to the first drive element (121) and the second end of the driveshaft (172) with the second drive element (131) and the axis of the driveshaft (170) and the axes of the drive element (121, 131) are in line,
   characterized in that
   the first guide profile (120) has a hollow profile and in the first guide profile (120) a drive element (121, 131) is at least partially integrated inside the first guide profile (120) and additionally the exactly one drive unit (160) is at least partially integrated into the first guide profile (120).
2. A drive unit (100) according to Claim 1,
   characterized in that
   at least one drive element (121, 131) has a spindle or each drive element (121, 131) has a spindle each with a different direction of rotation.
3. A drive unit (100) according to Claim 1,
   characterized in that
   each of the two drive elements (121, 131) has a double spindle with a different direction of rotation.
4. A drive unit (100) according to one of the previous Claims,
   characterized in that
   each drive element (121, 131) with at least one load-bearing element (191, 192) is effectively connectible.
5. A drive unit (100) according to one of the previous Claims,
   characterized in that
   the first guide profile (120) has a longitudinal slot through which a mounting for a load-bearing element (191, 192) protrudes.
6. A drive unit (100) according to one of the Claims 2 to 5,
   characterized in that
   the exactly one drive unit (160) has a gear (161), whereby the gear (161) can be driven and whereby the gear (161) with the driveshaft (170) is non-rotatably effectively connectible.
7. A drive unit (100) according to one of the Claims 1 or 2,
   characterized in that
   at least one drive element (121, 131) has a switchable gear to reverse the direction of movement of at least one load-bearing element (191, 192).
8. A drive unit (100) according to one of the previous Claims,
   characterized in that
   bearings (162) are provided in the drive unit (100) which are designed to absorb the lateral forces of the drive elements (121, 131).
9. A drive unit (100) according to one of the previous Claims, characterized in that
   the drive unit (160) has a housing (165), whereby axial forces of the drive elements (121, 131) are transferable though the housing (165) to the device for supporting and transporting the loads.
10. A drive unit (100) according to one of the previous Claims,
    characterized in that
    the drive device (100) has at least one connection element (125) and a second connection element (135) for accommodating the at least two load-bearing elements (191, 192), whereby the first connection element (125) is effectively connectible to a first bushing (121h) and the second connection element (135) to a second bushing (131h) with internal threads, whereby the first bushing (121h) is effectively connected to the first drive element (121) and the second bushing (131h) to the second drive element (131), whereby the drive elements (121, 131) each have an end stop (300), whereby a spring (400) is provided between the bushings (121h, 131h) and the respective end stop (300).

Images