WO2007048152A1

WO2007048152A1 - Load-lifting apparatus

Info

Publication number: WO2007048152A1
Application number: PCT/AT2006/000413
Authority: WO
Inventors: Franz Ehrenleitner
Original assignee: Franz Ehrenleitner
Priority date: 2005-10-28
Filing date: 2006-10-10
Publication date: 2007-05-03
Also published as: EP1948549B1; EP1948549A1

Abstract

The invention relates to a load-lifting apparatus, in particular for the car industry, with an upper platform (1) and a lower platform (2) arranged therebelow, wherein the lower platform is held on the upper platform by traction means (3) and is movable vertically by driving of the traction means, and with bracing means (4) which are provided between the upper platform and the lower platform and comprise elements which can transmit both compression and traction, and with a mechanical synchronizing device which co-ordinates the vertical distance between the two ends of the individual bracing means with each other. In order to increase the stability and to reduce the dead weight, the bracing means (4) are each oriented obliquely with respect to two vertical planes, which are normal to each other, and run at least along one section between upper and lower platforms.

Description

Load lifting device

The invention relates to a load lifting device, in particular for the automotive industry, with an upper platform and a lower platform arranged therebelow, wherein the lower platform is held on the upper platform by traction means and can be moved vertically by driving the traction means.

A load lifting device is known for example from EP 1 106 563 Bl. It consists of a top frame, a subframe and provided therebetween, connected to a drive traction cables. The traction cables are guided over pulleys on a motor-driven drum. In addition to fully vertical ropes, ropes are also provided, which extend partially obliquely to the vertical. Such a cable extends from the upper frame obliquely to the sub-frame, where it is steered around a roller and then extends vertically in the direction of the upper frame, where it is then connected to the same drive, which is also intended for the vertical cables. The partially inclined ropes serve to increase the stability of the sub-frame and the load hanging thereon. In order to prevent the load held by the load lifting device from falling due to a cable break and crushing a person working thereunder, a double vertical cable guide is proposed. Although additional ropes, pulleys and suspensions can prevent a crash, at the same time, however, the weight of the lifting device and thus also the manufacturing, assembly and maintenance costs increases.

DE 23 19 647 discloses a crane for lifting loads. In this case, a loading member, on which the loads to be transported are attached, hangs on hoisting ropes whose Auflängungspunkte are in the carriage of the crane. In addition to the hoisting ropes auxiliary ropes are provided, which are guided to a separate cable drum and which extend obliquely both to the longitudinal direction and to the transverse direction of the loading member. The loader itself is rectangular and all ropes, ie both auxiliary and hoisting ropes, engage in the corner areas of the loader. This design is designed to allow accurate load placement without causing larger pendulum motion. A pivoting of the load about a horizontal axis is not provided and with such a device also difficult and limited possible. All ropes or rope lengths would have to be coordinated in such a maneuver in a strictly defined manner to each other. The US 4,705,180 discloses a lifting device consisting of vertically arranged tension cables and in addition to four extending substantially along the edges of a pyramid to the loading platform auxiliary ropes. As in the previous publication, all ropes in the corner areas of the loading platform also attack here. A pivoting about a horizontal axis is not intended with such a device and also not possible, since all four traction cables are wound on the same cable drum.

US 5,769,250 (or the corresponding EP 0 793 615 B1) discloses a lifting device in which a loading platform can be raised or lowered by means of cables. All ropes acting in this device are aligned obliquely to the horizontal, wherein in each case a traction means, consisting of a roller attached to the loading platform and a revolving rope, engages in a corner region of the loading platform. In the area of the shorter sides of the loading platform are located between the arranged in each corner pulleys two more pulleys, run around the additional auxiliary ropes. The device disclosed in this document is based on the use of four identical but mechanically independent control mechanisms, which are tuned to a travel information of each auxiliary cable and the respective rotational speed of the motor connected to the auxiliary cable or the drum. It can be damped by such a device occurring in a horizontal plane vibrations, however, a pivoting of the position platform to a horizontal axis is not possible and not intended.

EP 0 123 846 A1 discloses a load lifting device with vertically extending hoisting ropes and inclined cables serving as pendulum damping, each lying within a vertical plane. The carrying roles of the vertical hoisting ropes are each arranged on a main cat, the support rollers of the stay cables on two provided on both sides of the main cat auxiliary cats. By varying the distance between the main cat and the auxiliary cats, the inclination of the stay cables can be changed. According to the disclosure, this is to serve, in the event that the load must be transported in a narrow shaft, to make the inclination of the stay cables smaller, so that their upper portions do not protrude beyond the contour defined by the hoisting ropes. However, if space enough for the stay cables, the auxiliary crabs are moved further apart, which increased swing damping can be achieved. The support rollers of the stay cables fastened to the load carrier are offset along the longitudinal extent of the load carrier and arranged coaxially with each other, whereby a horizontal axis of rotation is formed with the opposite rollers. However, since no separate drives for each two vertically extending hoisting ropes are provided (they are from the same support roller up or unwound), a pivoting of the load about the axis of rotation is not possible in this load lifting device. The specified ability to tilt the load in all directions is limited to minimal list and trim movements.

DE 3 241 380 A1 discloses a load suspension consisting of 4 cables which are guided in such a way that they have inclined and vertically extending sections (in particular FIG. 4 is self-explanatory). The oblique sections open in pairs (V-shaped) in each case in a point of application on a relative to the load carrier block. The movable block can be moved with respect to the hanger in the horizontal plane in two mutually normal directions (parallel to the longitudinal extent of the load and normal thereto) and additionally pivoted in the horizontal plane.

The movable block has two purposes to accomplish: If no pivoting or tilting of the load is desired, the relative movement of the block to the hanger serves to damp undesirably induced swinging motions. For this purpose, the movable block is connected via hydraulic cylinders to the load carrier. A hydraulic circuit coupled to the hydraulic cylinder provides damping when the movable block begins to move due to impacts, etc. This mechanism is intended to additionally strengthen the pendulum damping achieved by oblique bracing. However, if pivoting of the load is intended, then the hydraulic cylinder (or cylinders) is actuated by a pump and the block is moved relative to the load carrier. Due to the resulting imbalance, the load is pivoted accordingly.

US 3,653,518 A discloses a load hanger consisting of 4 ropes having substantially vertical sections and inclined sections. Starting from a common point of the subframe two ropes V-shaped apart, are deflected on the upper frame each by means of a roller in the direction of the subframe, from where it in turn deflected over a roller on a common drum on the upper frame be guided. With are called Trim actuators, which probably provide for a length compensation. The two adjacent to the sub-frame rollers are coupled together via a gear. Pivoting is not possible with this device.

All load suspensions described above have in common that the tension and tensioning means are only loadable on train, but not on pressure.

From the prior art, a load suspension is further known, in which at the lower platform in each case at the corners attacking, vertically extending tension cables are provided with which the lower platform is lifted. A stabilizing scissor-like structure connects the lower and upper platforms. The respective free Scherenarmende slides along provided on the upper and lower frame guides, whereby the total length of the scissor-type construction changes in the vertical direction. The use of such scissors-shaped devices has disadvantages, in particular because of their high weight. In this construction, occur almost exclusively in the lifting movement, as well as the interception of horizontal shear forces bending forces, therefore, all parts of the scissors design must meet the requirement of high bending stability, which is achieved for correspondingly massive dimensioning of the bending beam. A pivoting of the load about a horizontal axis is impossible due to the scissors mechanism.

Such a scissors-like mechanism is disclosed, for example, in EP 0 963 904 A1. All the scissors rods are in a vertical plane and all the above-mentioned disadvantages and limitations arise.

In the still unpublished international application PCT / AT05 / 000393 a Hubgehänge is disclosed, the upper fixed platform is connected to the lower, relatively movable platform by means of four vertically extending ropes. These ropes are each raised or lowered by individually operable motors including winches. The position stability is effected by three actuators, wherein in the disclosed embodiment, the actuators are variable-length rods in the form of a combination of hydraulic cylinder and piston rod. Each of the three actuators has a separate drive from the cable drives and is shortened or extended for the purpose of positional positioning of the load carried on the subframe. It is a parallel kinematic one Device in which both the actuation of the actuators, as well as the setting of the respective cable lengths must be coordinated. The illustrated device has two mutually parallel actuators and a Queraktuator, which runs in the illustrated case in the longitudinal center plane of the device, and derived occurring forces in this plane.

Another known from the prior art load hanger has vertically extending tension cables and two extending between the upper and lower platform non-driven telescopes. Via a cable mechanism, the two telescopes are connected to one another in such a way that during the lifting movement a common, mutually coordinated change in length of the telescopes takes place. The two telescopic tubes each extend in a direction aligned parallel to the longitudinal axis of the frame vertical plane and are rotatably mounted on the upper and lower platform each about a horizontal axis. Transverse forces acting on the lower platform cause high bending moments in the telescopic tubes and in their articulation points on the platforms. This requires the use of massive and appropriately sized bending beams and thus significantly increases the weight of the hanger. In addition, such a load suspension has the disadvantage that the lower frame can not be pivoted about a horizontal axis.

Such load suspensions are disclosed, for example, in EP 0265 813 A1 and US Pat. No. 4,273,242 A. The telescopes described in the two publications, which extend between the upper and lower platform, lie in a vertical plane and must be extremely massive in order to be able to act reasonably as stabilizers at all.

EP 1 157 960 A1 discloses a load hanger which can be actuated by means of vertical pull ropes and which additionally has a structure of bars extending between the upper and lower platforms and stiffening the hangers. This structure includes a centrally arranged, in the longitudinal direction parallel to the vertical plane lying scissors structure, wherein when lifting and lowering of the load in each case a Fußpunktverschiebung a scissor arm on the upper and lower platform. On both sides of the scissors structure is in each case one known as oscillating rod means consisting of two acute triangles, which are connected in their tips at half height between the upper and lower platform via a joint and are mutually pivotable about a horizontal axis. The baseline of the lower triangle coincides with the axis of rotation to the the Triangle is pivotable relative to the lower platform, while the baseline of the upper, upside down triangle coincides with the axis of rotation with respect to the upper platform. The scissor structure and the two oscillating rods composed of two triangles are mechanically independent of each other. Apart from the fact that the plurality of rods and mechanisms is an excessive weight load, such stabilization is inadequate for many purposes. For example, forces that urge the lower platform to oscillate about a horizontal longitudinal axis can not be trapped because each of them yields one triangle in which they collapse while the other triangles fold out on the opposite side. The articulation in the region of only short baselines of the triangles, but in particular the joint in the tips of which can not counteract the usually occurring transverse forces, so that a swinging of the load can not be efficiently prevented. Incidentally, for the purpose of maneuvering the load, the lower frame can not be pivoted about a horizontal axis.

US 3 241 686 A discloses a load lifting device with stabilizers made of bars which are synchronized with one another at their ends by means of intermeshing teeth. When lifting the load, the structure of two hinged together rods together, when lowering apart. The stabilizers run in a vertical plane, all axes of rotation lie in a horizontal plane. Even by this measure, a pendulum of the load can not be suppressed sufficiently strong, because forces normal to the vertical plane of the stabilizers cause enormous stress on the pivot points. As in previous references, for the purpose of maneuvering, the load can not be pivoted about a horizontal axis.

EP 1 426 275 A1, which is further away from the field of application, discloses a single fold-down solid frame, which is articulated on the lifting platform. Due to its weight and its inflexibility in terms of maneuvering the load, this lifting device is limited to a few applications.

Lifting equipment has to meet a lot of requirements in order to be efficient on the one hand and to be able to comply with the statutory safety precautions on the other hand. In addition, the production of such lifting devices should be connected inexpensively and without much effort. The following properties must be fulfilled:

- A high stability of the sub-frame including the attached hanger for receiving vehicle bodies, against forces acting thereon, for example, caused by acceleration or deceleration in the process to the next

Work step, human muscular strength, forces and vibrations by tools or other parts of the plant (manipulators),

- a low overall height in the retracted state at the same time high lift height,

a high degree of safety against the falling of the load, since in most of the work steps people are working next to or under the load lifting device or the load it holds,

- The smallest possible weight for large moving masses and thereby high component stiffness,

favorable production, assembly and maintenance costs of the load lifting device, a stroke speed which is as linear as possible, whereby lower-power and therefore more cost-effective motors can be used, a lifting movement preferably in the vertical direction,

Additional benefits for the user, e.g. Possibility of a rotary movement of the lower Aufhahmegestells to one of the two horizontal spatial axes.

There is a need for a Schwerlastgehänge especially for the final automotive assembly, which offer a market advantage over already known Hubgehängen by its low height in retracted state, its low weight and its low price. This advantage is to be further enhanced by, if necessary, pivoting the subframe about a horizontal axis, e.g. the longitudinal axis of an automobile, (at least up to an angle of 45 °) is possible. In the vehicle final assembly, pivoting about the longitudinal axis of the vehicle and pivoting across the vehicle longitudinal axis are most often important in the vehicle finish.

In summary, it can be stated that while there are lifting devices in the prior art, which allow a vertical lifting movement with a stabilization of the load against longitudinal, lateral forces and moments about the vertical axis, wherein the lifting motor has constant driving speed at a constant lifting speed. The stabilizers are either variants of driven scissors or scissors-like structures or Hinged or telescopic tubes. The devices of the prior art can allow pivotal movements only by increased effort eg serial intermediate levels. All these devices wear the forces always or at least for the most part by means of bending beams and are therefore very heavy. Dead weights of 3,000 kg - 5,000 kg with a payload of 2,000 kg are quite common.

All devices which use ropes as bracing means have the common disadvantage that the rigidity of the bracing means is limited. This is because the diameters of the winding drums may not be too large, the traction means can only accept a value proportional to the diameter of the drum (otherwise the stresses in the traction means would be too great due to the winding process). Furthermore, these lifting devices have in common that for tensioning the traction means always a drive (with all control components) or at least one energy storage unit must be available. Versions that distribute all traction means from a common drive, have the disadvantage that the lifting speed is highly non-linear.

The object of the present invention is to solve the problems arising from the prior art and to provide a load lifting device that is insensitive to forces, shocks, vibrations and the like in the horizontal plane as well as undesirable pivoting about the vertical axis. The drives required to lift and lower the load should be kept to a minimum, but without affecting the previously mentioned specification. Furthermore, the weight of the entire load lifting device must be kept as low as possible. Of particular importance is the fact that a load lifting device must be pivotable about a horizontal axis to allow access to different locations of the load.

According to the invention, these objects are achieved with a load lifting device mentioned in the introduction in that bracing means are provided between the upper platform and the lower platform and extend at least along a section between the upper and lower platforms, each aligned obliquely to both of two mutually perpendicular vertical planes and consist of elements that can transmit both pressure and tension, and that a mechanical synchronizer is provided which tunes the vertical distance between the two ends of the individual tensioning means to each other. The bracing itself have no own drive, but are changed exclusively by the lifting movement of the lower platform in their length. Since no drive for the Verspannmittel is needed, the weight of a load lifting device according to the invention can be reduced and the control, which now has to be done only on the traction means are simplified. At the same time, however, the stabilization effect of the tensioning means is considerably increased by the use of elements which can transmit tension and pressure. In order to prevent during the lifting process that caused by unequal length change of individual Verspannmittel pivoting or tilting of the load, the Verspannmittel, preferably in the region of the upper platform are mechanically synchronized.

In contrast to the prior art, exclusively tensile and compressive forces are transmitted in the tensioning means according to the invention. The load is distributed over the entire cross section substantially constant. Since no bending-stable elements as in the prior art for punctual peak loads are needed, the structure of the rod kinematics can be made in lightweight construction.

The synchronizer ensures that the tensioning means can not change their length independently or the vertical distances between the respective two ends of the individual tensioning means can not change independently of one another. The synchronizer must not be confused with the usual, indirect connection between individual Verspannmitteln on the lower or upper platform or the traction cables, because this indirect connection is just unable to effect a coordinated movement of all Verspannmittel. The synchronization according to the invention is actually an additional device that the

Clamping means directly interconnects and tunes their movements to each other and even then a synchronization of their lengths or the distances of their

Ends caused when synchronizer and Verspannmittel would be considered detached from the rest of the lifting device.

The following advantages can be achieved by the measure according to the invention: constant lifting speed due to constant input speed, since only the vertical traction cables have to be driven. - When using variable-length rods piezo elements can be used as a pressure gauge for measuring the mechanical stresses occurring. The measured variable itself can be used as a controlled variable for setting an electrical voltage, which optimally compensates for the mechanical displacements that have occurred on a further piezoelectric element in the cross-section of the rod.

- The stability and the effective distances of the tension, pressure elements is freely selectable and thus the stiffness as the weight of the lifting device positively influenced (according to the prior art, a mechanical Hubhänänge weighs 4-5 t and has a stiffness against shear forces of about 50 N. / mm - 100 N / mm, a comparable

Hanger of the type according to the invention has a stiffness of 300 N / mm at about 1.2 t own weight).

- There are no drives, motors, clamping devices and the like needed to operate the Verspannmittel can. - By appropriate connection of the tensioning means on the lower platform, this can be tilted without serial additional platforms around a horizontal axis.

- Due to the optimal arrangement and the fact that no additional motors are required for the Verspannmittel, and the favorable net weight, the manufacturing cost is halved compared to the prior art.

In a preferred embodiment, a tensioning means consists of a variable-length rod connecting the upper and lower platforms.

In one variant, a bracing means consists of two mutually articulated rod structures, which are pivotable relative to each other about a horizontal axis. The vertical change in length is a direct consequence of a change in the angle between the two parts.

In a further embodiment, the tensioning means are rods whose upper ends connected to the upper platform are horizontally movable, the rods undergoing a base-point displacement when lifting or lowering the load. In a preferred Ausffihrungsform the Verspannmittel engage in two points of attack on the lower platform, preferably located on the longitudinal center axis of the lower platform at.

In the following the invention will be explained in more detail with reference to the drawing. It shows

1 shows an embodiment of the load lifting device according to the invention with variable-length rods,

1a is a side view of the load lifting device of Fig. 1,

2 shows the clamping system with a synchronizing device, FIG. 2a shows the synchronizing device in detail,

Fig. 3 shows a variant of a synchronizer

4 shows an embodiment of the load lifting device according to the invention with mutually pivotable frameworks,

5 is a side view of the load lifting device of FIG. 4, FIG. 6 is a side view of the load lifting device of FIG. 4 in the retracted state,

Fig. 7 shows an embodiment of the load lifting device according to the invention

base support points,

8 shows a side view of the load lifting device from FIG. 7 with the synchronizing device and a connecting joint in detail, FIG. 9 shows a detailed view of a joint,

Fig. 10 section through a joint, and

Fig. 11, 12 and 13 a further embodiment with the formation of a triple point.

Fig. 1 shows a load lifting device according to the invention with an upper platform 1, an underlying lower platform 2 in the form of a frame which is held by vertically extending bending soft traction means, traction cables 3, on the upper platform 1 and vertically movable. The vertical traction cables 3 engage on the lower frame 2 at each of its corners arranged support rollers 18 and are deflected to rotatably mounted on the upper platform 1, driven by a motor 17 drums 16. At least 3 hoisting ropes are required to hold and lift the load, but it would also be conceivable to use more than 4 hoisting ropes depending on the loads to be lifted.

Within the cuboid defined by the traction ropes 3 are four rods 4 running obliquely to the vertical, which are also referred to below as the tensioning means, provided that are variable in length. Each of these four bars runs continuously between the upper and lower platforms in a substantially straight line and connects the two together. In the example shown, in each case two tensioning means run in the same obliquely to the vertical (in the coordinate system drawn for clarity) and parallel to the x-axis plane and form a pair of pointers whose origin is in the region of the point of application of the Verspannmittel on sub-frame (Sub Pointer pair are understood in this application, two straight lines, which lie substantially in one plane and emanate at least approximately from a single point). The other pair of pointers extends in a symmetrically inclined plane in the opposite direction. In the projection of the tensioning means in the x direction-as can be seen from the view of FIG. 1a-the individual bars intersect each other, but in reality they do not touch one another. Dashed line can be seen in Fig. Ia, the retracted position of the subframe.

The change in length of the rods 4 takes place solely by lifting or lowering the lower platform 2 relative to the upper platform. The variable-length rods therefore have no own drive. At least three of these continuous rods must be present to ensure stability, but it is advantageous to use more than three rods for efficient avoidance of pivoting about the vertical axis (z-axis in the coordinate system).

In the illustrated embodiment, the variable-length rods 4 consist of a threaded spindle 6, which is screwed into a provided at the end of a hollow cylinder 5 counter thread, the nut 5a, while disappearing inside the hollow cylinder. Of course, other variable-length rods may also be used, for example cylinder-piston units, telescoping rods, racks, all types of spindles, combinations of threads and counter-threads, more generally parts that mirror each other.

While on the upper platform each rod 4 acts on its own point of attack, preferably in each case at the corners of the largest possible rectangle, two bars each run in a V-shape towards a common point of application 9a or 9b on the lower frame 2. Preferably, the common points of attack 9a and 9b are on the Longitudinal central axis 15 (parallel to the y-axis of the imaginary coordinate system) of the lower platform. 2

The lifting and lowering of the load takes place exclusively by operating the traction cables 3. The task of extending obliquely to the vertical bars 4 is to stabilize the lower platform 2 with respect to the upper platform 1 and in particular in the horizontal

Level occurring forces acting on the sub-frame 2 to catch. In the illustrated preferred embodiment, the bars 4 are each double oblique to

Aligned vertically, i. they arise as a line of intersection of two obliquely oriented to the vertical planes. By this measure forces can be taken from all horizontal

Directions are best absorbed.

At the point at which two rods 4 open into a common point of application 9a or 9b on the lower frame 2, a joint 14 is provided, which allows a pivoting of the lower frame 2 about the horizontal axis of rotation 15. For the purpose of pivoting two independent motors must be provided for the traction cables. In the load lifting device of Fig. 1 thus the two drums 16 shown would be operated separately from each other. There is nothing against it and is for the expert in the knowledge of the invention no problem to let the tensioning means run so that a rotation axis is parallel to the x-direction.

An essential part of the invention is that the change in length of the variable-length rods 4 is not carried out for each individual rod independently of the others, but that they are synchronized with each other. For this purpose, the threaded spindles 6 are connected at their end facing the upper platform 1 with a synchronizing device 7.

Fig. 2 shows such a synchronizing device 7, wherein for better clarity, the upper and lower platform and drive was omitted. By lifting the load, the threaded spindles 6 are rotated due to the nuts 5a. The rotational movement of the spindle is - as shown in the detail drawing of Fig. 2a - converted via a joint 20, for example, a universal joint, in a rotational movement about a horizontal axis 21, whereby a plurality of one or more circumferential bands 22 coupled to each other rollers 23 in Movement be offset. The bands stand with the Rolls 23 in positive engagement, for example via intermeshing ribs, which are provided in a corresponding manner on the inside of the bands and along the circumference of the rollers. About a connected to a roller 23 torsion shaft 8, the rotational movements of two combined by bands 22 threaded spindles 6 are synchronized with those of the attacking at the opposite end of the upper platform threaded spindles.

3 shows a variant of a synchronizing device 7: The rotating threaded spindles 6 are connected via a joint 25 provided at their upper end, e.g. a Kardangelenk, with a horizontally extending and about a horizontal axis of rotation 24 rotatable rod 26 (the storage of the rod to the upper platform is not shown for clarity) connected. Via a bevel gear 27 and a torsion shaft 8, the transmission to the opposite pair of pointers takes place.

The effect of the synchronizer is that the length of all tensioning means always changes uniformly. An irregular change in length of one or more bracing means would cause the lower platform to tilt about any pivot point and become unstable.

4 shows a second variant of the invention in which the tensioning means do not extend over the entire distance between the platforms but only over a section. The four bracing means 30 are rods which, like the bracing means in the first example, are each oriented obliquely to both of two mutually perpendicular vertical planes. In each case two of the bracing means 30 form a pair of pointers originating in the region of the subframe, thus each run in a V-shape towards a common point of application 9a or 9b of the subframe 2, and are combined to form a triangular planar framework 10. FIG. The other two bracing means are mirror images aligned and form the framework 10 '. Between the upper ends of the tensioning means 30 and the upper platform, a spatial truss 31 extends.

In the following, the structure and operation will be explained with reference to a coordinate system indicated in FIG. 4. The composite to a triangular framework 10 tensioning means 30, and the upper framework 31 are articulated in the area between the upper and lower platform to each other such that they against each other about a horizontal axis 32 (parallel to the x-direction) are pivotable. The upper framework 31 is also pivotable relative to the upper platform 1 about a horizontal axis 33 (also parallel to the x-direction). The system consisting of the skeleton 10 containing the Verersparmmittel 30, the upper framework 31 and upper platform (detached from the other parts of the lifting device) behaves such that pivoting of the individual parts against each other about two horizontal axes (fixed axis between the upper frame and upper framework and variable axis between upper framework and lower framework) are possible. However, with respect to force components acting in the x direction, the system behaves stiffly, whereby the tensioning means exerts a stabilizing function on the lower platform. If one looks at the overall system, ie together with the mirror-image parts, ie lower truss 10 'and upper truss 31' and the sub-frame, then it is also stiff compared to force components in the y-direction.

In the projection in the x-direction results in a z-axis substantially symmetrical course of the clamping means, as shown in FIG. 5 or FIG. 6, which represents the retracted state, can be seen.

The change in length of the entire system is not as in the previous example by a change in length of the individual rods, but by a pivoting or

Folding the two frame parts 10, 31 and 10 ', 31' against each other, thus by a

Angle change. However, the tensioning means 30 are as in the first embodiment in

Area of the upper platform 1 coupled together via a Synchronisiereichrichtung 7, while the upper framework 31, 31 'only a connection between the Synchronisiereirnichtung and the Verspannmitteln ago. When changing the vertical

Distance between the two ends of the individual tensioning means 30 is pivoted in each case the upper frame part 31 with respect to the upper platform. This rotational movement is transmitted respectively to gears 34, 34 '. By the meshing of the gears, the synchronization of the vertical distance of the two Verspannmittelenden done. Of course it would also be conceivable to synchronize by means of belts, toothed belts,

Racks etc.

The upper and lower frameworks 31, 10 need not necessarily be designed as frameworks. Other flat or spatial rigid structures, such as corrugated or ribbed plates, would also be possible, as long as the special arrangement does not require penetration of the parts. It is only important that the two parts 10, 31 are pivotable about an axis against each other, behave in the direction parallel to this axis as a rigid structure.

As in the embodiment of Fig. 1, the change in the distance between the two ends of the individual Verspannmittel exclusively by lifting and lowering the lower platform by means of tension cables. None of the Verspannmittel thus has its own drive. As in the embodiment of FIG. 1, the points of application 9 a and 9 b of the lower rod are workpieces 30 in the form of joints 14 which allow rotation of the subframe about a horizontal axis 15.

The two frameworks 10 and 10 'containing the bracing means 30 penetrate each other, but do not touch each other in the area between the platforms.

In the case of Fig. 1, the variable-length rods each extend in a plane which is aligned twice obliquely to the vertical. By this measure it is achieved that disturbances can be intercepted from both spatial directions and can lead to any vibration of the load hanger. In the embodiment of FIG. 4, this is achieved by the same principle, but in a variant. The trusses are each constructed so that a pivoting about other than the two horizontal axes is not possible, whereby the load lifting device behaves like a rigid system with respect to all horizontally acting forces.

FIGS. 7 and 8 show a further variant of the invention. In this case, the bracing means 40 are again constructed of rods which are each aligned obliquely to two of two mutually perpendicular vertical planes. The bars extend continuously between upper and lower platform. As in the example of FIG. 1, two bars respectively run towards a common point of attack on the subframe with the formation of a horizontal axis of rotation 15. In contrast to FIG. 1, the upper ends of the bars do not retain their position with respect to the upper platform, but instead are movable along the upper platform. In the illustrated embodiment, in each case the upper ends of two rods formed into a pair of pointers are connected to one another via a horizontal rod 41 to form a triangular planar framework. The two pairs of pointers act in turn via a Synchronisiereiiirichtung 7, which is shown in Fig. 8 in detail together. The bracing means 40 are articulated to horizontally (in y-direction) displaceable racks 42 which are in opposite sense with a pinion 43 in engagement. The vertical distance between the upper and lower ends of a tensioning means (ie the length resulting from a projection of the rods on the z-axis) can thus only change to the same extent with all tensioning means.

From Fig. 9 and 10 it can be seen clearly that the bracing pass at its lower end in a joint 14, which allow the rotation of the lower frame 2 with respect to the Verspannmittel about an axis 15, by the two opposite points of attack 9a, 9b on the subframe is defined. In the illustrated embodiment, this is a universal joint. Of course, also conceivable hinges, ball joints and the like.

It is also possible to provide pressure sensors, such as piezoelements, for the individual bars of the tensioning means, with which the tension or pressurization within the bars can be determined. The voltage generated by the piezoelectric element can then be used as a controlled variable for an excitation voltage which is applied to a further piezoelectric element arranged in the rod in the form of a piezo pack or piezostack. The excitation voltage causes a change in length of the piezoelectric element and thus of the rod itself, which can be compensated from tensions resulting changes in length in the individual rods.

The invention is not limited to the illustrated examples, so the synchronizer can take all conceivable forms, as long as a coordinated change in length of all Verspannmittel is guaranteed. Also, the formation of the bracing means is not limited to rod constructions, other rigid full-surface or spatial structures are conceivable, but represent rods and frameworks due to weight considerations preferred variants.

In principle, an arrangement of the synchronizing device in the region of the subframe is possible. The illustrated examples would only be upside down or reversed with the lower platform. However, the arrangement in the region of the upper platform is a preferred variant, as this makes it easier to achieve a horizontal Rotary axis of the subframe can be realized and the synchronizer itself does not have to be lifted.

In the example of Figure 4, the synchronizer could also be in the middle in the region of the horizontal axes of rotation, e.g. with a similar combination of racks and a pinion as in the example of Fig. 7. I

I The type and components of the synchronizer used are not essential to the invention. Thus, all possible combinations of spindles, nuts, racks, pinions, gears, hydraulic cylinders, telescopes, rotating ropes, belts, chains, etc., joints such as cardan joints, swivel joints, ball joints, etc. can be used.

Also, the number of bracing means may vary, but at least three should be present in order to insure the load lifting device against all possible lateral forces.

11 and 12, a variant of the invention is shown, wherein the pliable traction means 3 and the composite of rods 4 Verspannmittel are shown in a purely schematic manner. The tensioning means may, of course, be all variants already described. For clarity, the upper platform in Fig. 11 is hidden. As the example of FIGS. 11 and 12 shows, it is not absolutely necessary that the common point of application 9a or 9b of two tensioning means, in the present case two variable-length bars 4, is arranged centrally on the lower platform between the points of application of the traction means 3. In the illustrated embodiment, the rotational axis 15 defined by the two points of application 9a and 9b of the tensioning means is not above the geometric center of gravity of the lower platform 2. Also, it is not absolutely necessary to use four traction means 3, in principle three of them suffice. Also, the traction means 3 are not arranged in the corner region of the loading platform, but each form together with the point of application 9a or 9b two Verspannmittel 4 a so-called. Triple point. A third traction means is laterally spaced from the axis of rotation 15 in the region of the outer side of the lower platform 2. This embodiment is preferred because only one laterally spaced traction means must be actuated for pivoting the load, which is for this purpose also has its own drive. Fig. 12 shows the front view of the device according to the invention.

How the connection of the tensioning and traction means can be made at the triple point is shown in FIG. 13 in detail. It is also a universal joint, wherein the traction means 3 is connected to the sub-frame 2 via an axle 44 which is identical to an axis of the universal joint.

In order to reach the pivoted state, only the traction means spaced from the axis of rotation 15 must be actuated in this preferred embodiment. The length of all other tension and tensioning means remains constant. As can be seen from the detailed views, the joint in the triple point is so connected to the subframe that the subframe in

Reference to the hinge about the rotation axis 15 is rotatable. To be a simple one too

To be able to perform pivoting in the other direction, a fourth traction means, which acts on the opposite side of the subframe, can also be provided.

It is not absolutely necessary that the points of attack 9a or 9b of the

Defining means defined axis of rotation 15 is oriented parallel to the vehicle longitudinal axis. In principle, any orientation is possible, but especially in the

Fahrzeugendmontage pivoting only about the vehicle longitudinal axis and in the vehicle immersion pivoting transverse to the vehicle longitudinal axis of importance.

A similar load lifting device, in which two triple points are formed, is described in the still unpublished international patent application with the application number PCT / AT05 / 000429. The entire contents of PCT / AT05 / 000429 are incorporated by reference into this specification.

Claims

claims

1. Lifting device, in particular for the automotive industry, with an upper platform and a lower platform arranged therebelow, wherein the lower

Platform held by traction means on the upper platform and is moved vertically by driving the traction means, and provided between the upper platform and the lower platform Verspannmittel consisting of elements that can transmit both pressure and train, and with a mechanical synchronizer adjusting the vertical distance between the two ends of the individual bracing means, characterized in that the bracing means (4, 30, 40) are each aligned obliquely to both of two mutually perpendicular vertical planes and at least along a section between the upper platform (1 ) and lower platform (2).

2. Lifting device according to claim 1, characterized in that the tensioning means (4, 30, 40) are variable-length rods.

3. Lifting device according to claim 2, characterized in that the variable-length rods each of a spindle (6) and a nut (5a) are constructed.

4. Lifting device according to claim 3, characterized in that the synchronizing device (7) synchronizes the rotation caused by the change in length.

5. Lifting device according to claim 1, characterized in that the one ends of the tensioning means (40) on the upper platform (1) are arranged movable and synchronizing means (7) synchronizes the Fußpunktverschiebung on the upper platform (1).

6. Lifting device according to one of claims 1 to 5, characterized in that the Verspannmittel (30) only over a portion between the upper platform (1) and lower platform (2) and are connected via connecting parts (31) with the synchronizer (7).

7. Lifting device according to one of claims 1 to 6, characterized in that at least four Verspannmittel (4, 30, 40) are provided, wherein each two

Clamping means (4, 30, 40) at least approximately in a common point (9a, 9b) on the lower platform (2) attack.

8. Lifting device according to one of claims 1 to 7, characterized in that the ends of each two Verspannmittel (4, 30, 40) pass into a joint connected to the lower platform joint (14), which is the rotation of the lower platform (2). with respect to the tensioning means (4, 30, 40) allowed about a rotation axis (15), which is given by the two engagement points (9a, 9b).

9. Lifting device according to one of claims 1 to 8, characterized in that the synchronizing device (7) rollers (23) which are connected to each other via at least one circumferential, with the rollers (23) positively cooperating band (22).

10. Lifting device according to one of claims 1 to 8, characterized in that the synchronizing device (7) comprises racks (42) which are in opposite sense with a pinion (43) into engagement.

11. Lifting device according to one of claims 1 to 8, characterized in that the synchronizing device (7) comprises two toothed wheels (34, 34 '), which together in

Engage.

12. Lifting device according to one of claims 1 to 8, characterized in that the synchronizing device (7) comprises hydraulic cylinders.

13. Lifting device according to one of claims 1 to 8, characterized in that in each case two Verspannmittel (30, 40) to a rod factory (10) are composed.

14. Lifting device according to claim 2, characterized in that the variable-length rods (4) are each constructed from a cylinder-piston unit.

15. Lifting device according to one of claims 1 to 14, characterized in that each two Verspannmittel (4, 30, 40) at least approximately in a common point (9a, 9b) engage the lower platform (2) and that in each case a traction means ( 3) engages at least approximately at the two points of attack (9a, 9b) and with the two clamping means (4, 30, 40) forms a triple point per point of attack.