EP1190981B1 - Scissors-type lifting table - Google Patents

Abstract

The scissor action elevating platform has a scissor mechanism (4) with inner (5) and outer (6) scissor members. One of the scissor members has two cams (8), and the other has two slides or suchlike movable to and fro along the scissor member onto the cams, acting as a drive (7). The slides are positioned in such a way that in the lowered position of the platform's upper frame (3) they lie on the cams on both sides in the edge region.

Description

The invention relates to a scissor lift with a lower frame, a one Working plane or a table forming upper frame and one between the lower frame and the upper frame acting scissors mechanism, wherein the Scissors mechanism includes intersecting inner and outer scissor members, the for raising or lowering the upper frame are actuated, wherein at least a pair of intersecting scissor members drive means zugeodnet are and wherein the one scissor link two curves are assigned.

Scissor lift tables have been known in practice for many years. Merely as an example For this purpose, the DE-AS 11 75 852 and the registered documents of the German Utility Model 79 32 713 referenced. The drives disclosed there in addition to which the scissor members act with force acting Anstellorgan to the prior art and will not be discussed further below.

From DE 196 49 867 A1 discloses a scissor lift is known in which the free Ends of the scissors links on one side via fixed hinge axes with the upper one and the lower frame are pivotally connected. On the other side are the free ends of the scissor members equipped with rollers and run in the upper frame and the lower frame associated guide rails. Becomes erected the scissor mechanism by the geared motor provided there, The ends of the scissor members, which are provided with fixed joint axes, remain on fixed on one side of the two frames. The opposite free ends the scissor members roll towards the middle when the scissor mechanism is raised Accordingly, the fixed - compared to the two frame - ends of the Scherenglieder, whereby the Aufrichtbewegung and thus the lifting of the Table level results.

From DE 44 13 527 A1 a generic Scherenhubtisch is known which corresponds to the preamble of independent claim 1. The pairs of intersecting scissor links are driving means and each scissor link assigned two curves. To operate the scissor lift table are special rollers provided, the pair of scissor pairs in pairs and while on both sides along the curves by means of a cylinder-piston assembly for erecting the lift table can be moved together and moved apart to lower the lift table.

However, the known from DE 44 13 527 A1 scissor lift is so far problematic when a total of four pairs of rollers are required for actuation, which are subject to wear. They are also used to unroll the rollers required curves assigned in pairs to each of the scissor links, so that for changing the stroke characteristic both scissor members would have to be exchanged, which is excluded in practice. Due to the all scissor links in pairs associated curves is not only the design effort but in terms of a wear and tear of maintenance costs considerably.

Based on the above-described problems in the generic Scissor lift is the object of the present invention a scissor lift of the generic type to design and thus to develop that with a simple construction maintenance-friendly operation results.

The above object is solved by the features of claim 1. Thereafter, the generic Scherenhubtisch is characterized in that the other scissor member two along the scissor member on the curves on each other to and away from each other movable carriage or carriage as a drive means assigned.

According to the invention has therefore been recognized that a robust and thereby reliable design of the drive means can realize that one realized a kind of tandem drive, namely, in each case one of the scissor members two curves are assigned. Accordingly, the other scissor link are two along the scissor link on the curves towards and away from each other movable carriages or carriages associated with the cooperating Curves and carriages or sleds are the main driving means of the Form scissor lift table. In accordance with the invention, the load is distributed during Lifting the work plane or table onto at least two arrangements of Curves and wagons or sleds, with the interaction between wagons or carriage with the curves causes the actual stroke of the scissors mechanism. Ultimately, there are at least two cars or sledges along the two Traversing curves so that a stroke of the working plane or the table takes place.

Advantageously, the carriages or carriages are positioned so that they are in the lowered state of the upper frame or the work plane on both sides in Edge area abut the curves. To lift the upper frame are the Carriage or sled over a drive along the carriage or sledge leading scissor link on the curves or in engagement with the curves movable towards each other. To lower the upper frame are the car or Slide away from each other, in the simplest case on the Gravity takes place.

Another advantage is when the two curves on both sides of the crossing point the scissor members, preferably at least slightly spaced therefrom, are arranged on the respective scissor member. Such a design provides a central focus and contributes to the stable and stable design the device at.

It is also conceivable that at least one of the two curves in their position the scissor member is variable, namely, a change in the stroke characteristics cause. This could be the curves on the one hand in their position along the Scissor link and on the other hand changeable in their angular position to the scissor link be. An exchange of curves is also conceivable, namely by change the waveform to be able to realize a different stroke characteristics. An optimal Adaptation to the loads to be lifted and other conditions possible.

In particular, it should be emphasized that the curves with their predetermined curve shape serve to influence the kinematics and dynamics of the lifting / lowering movement. The curves can be designed such that at constant speed the drive lifts the upper frame or the table at a constant speed and / or lowers. With the interchangeability of the curves is the greatest possible flexibility realized the scissor lift.

With regard to the distribution of forces during the lifting movement, it is from far away Advantage, if the two curves with their active or running surfaces on opposite Pages of the scissor link are arranged so that the carriages or carriages Run on opposite sides. A mutual pushing away between the two curves on the one hand and the car or carriage on the other causes the operation of the scissors mechanism and thus a lifting of the table.

As part of a particularly simple construction, it is advantageous if the car or carriage in a rail associated with the respective scissor member run, wherein the rail may be formed in cross-section U-shaped. in the Concretely, the rail could laterally on the scissor member, preferably on the respective Inside, be provided with the car or carriage in the rail are slidable or rolling in the rail. As part of a particularly simple Embodiment, a carriage could be displaced within the rail.

In any case, a reduction in the forces required at startup is achieved. when a car rolls in the track, with the least possible rolling resistance. In that regard, the engaging in the rail guide elements of the Carriage be designed as preferably ball-bearing rollers, wherein the guide elements need sufficient space within the rail.

For a perfect functioning of the scissor lift, it is from far more Advantage, if the car or carriage each at least one preferably Ball bearing Abtragrolle to roll on the curve. Also in this respect The forces required to open or start up are reduced. One proper procedure along the curve surface is guaranteed.

As previously stated, the movement of the car or Carriage along the cam surface for operating the scissors mechanism. Any drives for the car or carriage are feasible. Especially Advantageously, the carriages or carriages are moved by traction means, with special arrangements made to the car or sled are. In concrete terms, the carriages or carriages could be very special holding means and / or at least one deflection roller for a traction means, wherein the Traction means from the drive forth the two carriages or carriages on the holding means and so interconnects on the pulleys, that when pulling the By means of the two carriages or carriages - rolling on the curves - under Pulley effect are movable towards each other.

At this point, it should be emphasized that a realization of here addressed pulley effect again the forces required for lifting reduced, depending on the number of roles provided there. According to that Pulley principle, the required forces can be significantly reduced, at least half.

As a special traction means are belts, ropes or chains in question. Anyway the traction means over the carriage or carriage associated pulleys so firmly connect with one of the carriages or carriages while pulling on the Traction means the two cars or carriages moved towards each other equally be under the action of the respective Abtragrolle on the Curve surface. A safe lifting movement of the scissors mechanism is thereby realized the simplest construction.

In the context of the above, it was assumed that the Drive means are assigned only to a pair of scissor members. Should with the scissor lift according to the invention in particular lifted heavy loads be, so it is advantageous if the drive means in addition to rails two pairs the scissor links are assigned. In such a case, the car or Slide over a yoke in the arranged on the inside of both scissor links Rails by means of the guide elements, preferably by means of ball bearings Casters, intervene. Accordingly, on both sides of the yoke Abtragrollen for Rolling be provided on the curves. In the context of such an embodiment the yoke could preferably arranged centrally between the scissor members Wear pulley, which is sufficiently wide to accommodate several Traction means may be formed. The use of two or three traction means, the are arranged parallel to each other and preferably together over the same Turn pulleys run, would be conceivable and would on top of an increased level of Operational safety. Even with destruction of a single traction device could the other one or could the others still work adequately?

Furthermore, it is conceivable that the scissor mechanism several side by side or also arranged on top of each pair of scissor members. In that regard could a kind of two-story design of the scissor mechanism can be realized to namely to be able to realize very considerable lifting heights. If the pair of scissor links arranged one above the other, could be a common drive of the scissors mechanism take place, namely, namely, the pairs of scissor links on common Traction means are actuated.

In terms of operational safety, it is of further advantage when monitoring functioning, in particular to ensure adequate Operational safety, special monitoring means are provided. These monitoring devices For example, the traction monitoring detectors and / or directly the traction means monitoring detectors include. Upon detection of a malfunction, in particular damage to the traction means and / or the scissors mechanism, the drive could be switched off automatically. In a further advantageous manner In case of such a detection, the scissor mechanism is locked in its position or blocked, so that a taking place due to damage lowering the table is effectively avoided.

The drive, in particular the drive for the traction means, could be designed as an electric motor be, with a pneumatic or hydraulic actuation also conceivable is. Regardless of the specific embodiment of the drive could this the lower Be assigned frame or even outside the frame or off be arranged the actual scissor lift.

Fig. 1

in einer schematischen Seitenansicht ein Ausfürungsbeispiel eines erfindungsgemäßen Scherenhubtischs, wobei der Tisch angehoben ist,

Fig. 2

in einer schematischen Seitenansicht den Gegenstand aus Fig. 1 bei abgesenktem Tisch,

Fig. 3

in einer schematischen Draufsicht, teilweise, den Scherenhubtisch aus Fig. 1,

Fig. 4

in einer schematischen Ansicht den als Antriebsmittel zur Betätigung der Scherenglieder dienende Wagen mit Joch und

Fig. 5

die Anordnung aus Fig. 4 im Eingriff mit der zur Führung dienenden Schiene.

There are now various possibilities for designing and developing the teaching of the present invention in an advantageous manner. For this purpose, on the one hand to the claims subordinate to claim 1, on the other hand, to refer to the following explanation of an embodiment of the invention with reference to the drawings. In conjunction with the explanation of the preferred embodiment of the invention with reference to the drawing, generally preferred embodiments and developments of the teaching are explained. In the drawing shows

Fig. 1

1 is a schematic side view of an exemplary embodiment of a scissor lift table according to the invention, wherein the table is raised,

Fig. 2

in a schematic side view of the object of FIG. 1 with the table lowered,

Fig. 3

in a schematic plan view, partially, the scissor lift of Fig. 1,

Fig. 4

in a schematic view serving as a drive means for actuating the scissor members carriage with yoke and

Fig. 5

the arrangement of Fig. 4 in engagement with the rail serving for guiding.

Figs. 1 and 2 show - in the extended and retracted state of the lifting mechanism - A scissor lift with a lower frame 1, a working plane or a table 2 forming the upper frame 3 and one between the lower Frame 1 and the upper frame 3 acting scissors mechanism 4, wherein the Scissor mechanism 4 intersecting inner scissor members 5 and outer scissor members 6 operable to raise or lower the upper frame 3 are. In the embodiment chosen here, both pairs of Crossing scissor members 5, 6 associated drive means 7, wherein the Fig. 1 and Figure 2 shows only a pair of the inner and outer scissor members 5, 6.

In each case a scissor member - the outer scissor member 6 - are two curves. 8 and the other scissor member - the inner scissor member 5 - two along the Scissor member 5 on the curves 8 towards each other and away from each other movable Car 9 assigned as a drive means 7.

In Figs. 1 and 2 is further indicated that the scissor members 5, 6 at their one end with the frame 1, 3 stationary and pivotally connected are. With the other ends, the scissor members 5, 6 slidably engage in the Frame 1, 3, in order to realize the scissor movement. Special Guides 10 are provided.

Fig. 2 shows particularly clearly that the carriage 9 is positioned or arranged are that they in the lowered state of the upper frame 3 and the table 2 on both sides in the edge region of the curves 8 abut. Because of this arrangement Already at a slight movement of the carriage 9, the lifting movement is initiated.

Figs. 1 and 2 further show together that the carriage 9 for lifting of the upper frame 3 via a merely indicated drive 11 along the Carriage 9 leading inner scissor member 5 on the curves 8 toward each other to move and for lowering the upper frame 3 away from each other by gravity are movable. If therefore the drive 11 is switched off or finds relief instead, the carriages 9 can travel along the cam surfaces 12 due to the Move back gravity, so that a lowering movement of the upper frame. 3 takes place.

Figs. 1 and 2 further show that the two curves 8 on both sides of the crossing point 13 of the scissor members 5, 6 arranged on the outer scissor member 6 are. The curves 8 are at least slightly to the intersection point 13th spaced.

With regard to a variability or interchangeability of the curves 8 is to avoid from repetitions to the general description. The same applies to the associated influence on the kinematics or the dynamics of the Lifting / lowering movement.

1 and 2 show particularly clearly that the two curves 8 with their active or running surfaces 12 on opposite sides of the outer scissor member. 6 are arranged, so that the inner scissor member 5 associated carriage. 9 Run on opposite sides. This results in a special stable construction.

In Figs. 1 to 5 is indicated in total that the carriage 9 in one of the respective Scissor member - inner scissor member 5 - associated rail 14 run. at In the embodiment shown in the figures, the rail 14 is U-shaped in cross-section formed and laterally on the inner scissor member 5 - on the respective inner side - intended. Specifically, the carriage 9 is rollable in the rail 14, wherein to a very special guide 15 is provided. This is indicated in Fig. 5.

In the Fig. It is further shown that the carriage 9 each have a ball bearing Abtragrolle 16 have to roll on the curve 8. This is special clearly Figs. 1, 4 and 5 refer.

The carriages 9 furthermore each comprise a deflection roller 17 as well as holding means 18 for fixing a traction means 19, wherein the traction means 19 - here in the form of a Belt - is guided over the pulleys 17 up to the holding means 18, that the pulley principle applies to the reduction of the forces required for lifting. Also in this respect is to avoid repetition on the introduction to the description directed.

Figs. 3, 4 and 5 show particularly clearly that the drive means 7 together with the for guiding rails 14 associated with both pairs of scissor members 5, 6 are. The cars 9 are equipped with a yoke 20, so that a two-sided engagement in the rails 14 for guiding the carriage 9 is realized. Of the Intervention takes place in accordance with the above statements on the guide elements 15, on both sides of the yoke 20.

Fig. 5 indicates, hinted, that the guide elements 15 as rollers 21 are formed. On both sides of the yoke 20 are removal rollers 16 for unrolling provided on the curves 8, which can be seen particularly clearly in FIGS. 3, 4 and 5 is. Figs. 3, 4 and 5 show further clearly that the yoke 20 the centrally disposed between the scissor members 5, 6 arranged guide roller 17, the sufficient is configured wide, namely for receiving or for deflecting a Traction means or more traction means 19.

Finally, it should be noted that in the embodiment chosen here as Traction means only a belt 19 is provided which - symbolically indicated in Fig. 1 - About a lower frame 1 associated drive 11 runs. The drive, For example, an electric motor could also outside the lower frame 1, so that a connection or a coupling from outside is required.

Finally, his special emphasis should be that discussed above Embodiment of the exemplary explanation of the claimed teaching is used However, this does not restrict to the embodiment.

Claims (15)

1. Scissor-type lifting table having a lower frame (1), an upper frame (3) which forms a working plane (2) and a scissor mechanism (4) which acts between the lower frame (1) and the upper frame (3), the scissor mechanism (4) having inner and outer scissor members (5, 6) which intersect and which can be actuated in order to raise or lower the upper frame (3), drive means (7) being associated with at least one pair of the intersecting scissor members (5, 6) and two curved members (8) being associated with the first scissor member (6), characterised in that two carriages (9) or slides which can be displaced towards and away from each other along the scissor member on the curved members (8) are associated with the second scissor member (5) as drive means (7).
2. Scissor-type lifting table according to claim 1, characterised in that the carriages (9) or slides are positioned in such a manner that they abut the curved members (8) at both sides in the peripheral region when the upper frame (3) is in the lowered state.
3. Scissor-type lifting table according to claim 1 or claim 2, characterised in that the carriages (9) or slides can be moved by means of a drive (11) towards each other along the scissor member (5) which guides the carriages (9) or slides on the curved members (8) in order to raise the upper frame (3), and can be moved away from each other in order to lower the upper frame (3).
4. Scissor-type lifting table according to any one of claims 1 to 3, characterised in that the two curved members (8) are arranged at both sides of the intersection point of the scissor members (5, 6) on the respective scissor member (5, 6), at least one of the two curved members (8) being able to be adjusted in terms of its position on the scissor member (6).
5. Scissor-type lifting table according to any one of claims 1 to 4, characterised in that the curved members (8) can be adjusted in terms of their position along the scissor member (6) and/or in terms of their angular position relative to the scissor member (6).
6. Scissor-type lifting table according to any one of claims 1 to 5, characterised in that the curved members (8) serve to influence the kinematics and dynamics of the lifting/lowering movement with the curved form thereof which can be predetermined.
7. Scissor-type lifting table according to any one of claims 1 to 6, characterised in that the curved members (8) are constructed in such a manner that the upper frame (3) or the table (2) is lifted and/or lowered at a constant speed when the speed of the drive (11) is constant.
8. Scissor-type lifting table according to any one of claims 1 to 7, characterised in that the two curved members (8) are arranged with the operative or running faces (12) thereof at opposing sides of the scissor member (6) so that the carriages (9) or slides run at mutually opposing sides.
9. Scissor-type lifting table according to any one of claims 1 to 8, characterised in that the carriages (9) or slides run in a rail (14) which is associated with the respective scissor member (5), the rail (14) being able to be constructed so as to have a U-shaped cross-section and being provided at the side on the scissor member (5), the carriages (9) or slides being able to be displacable, or being able to run in the rail (14), and the carriages (9) or slides having guiding elements (15) for engaging in the rail (14).
10. Scissor-type lifting table according to any one of claims 1 to 9, characterised in that the carriages (9) or slides each have at least one disengagement roller (16) for rolling over the curved member (8).
11. Scissor-type lifting table according to any one of claims 1 to 10, characterised in that the carriages (9) or slides have retaining means (18) and/or at least one redirecting roller (17) for a pulling means (19), the pulling means (19) being able to connect the two carriages (9) or slides from the drive (11) by means of their retaining means (18) and by means of the redirecting rollers (17) in such a manner that, when the pulling means (19) is pulled, the two carriages (9) or slides - rolling over the curved members (8) - can be moved towards each other with a pulley-like action, and a belt (19), a cable or a chain being able to be used as a pulling means (19).
12. Scissor-type lifting table according to claim 11, characterised in that the drive means (7) including rails (14) are associated with both pairs of the scissor members (5, 6), and in that the carriages (9) or slides engage, by means of a yoke (20), in the rails (14) which are arranged at the inner side of the two scissor members (5, 6) by means of the guiding elements (15), disengagement rollers (16) being able to be provided at both sides of the yoke (21) for rolling over the curved members (8), the yoke (20) being able to carry the redirecting roller (17) and two or three pulling means (19) being able to be arranged parallel with each other and running together over the same redirecting rollers (17).
13. Scissor-type lifting table according to any one of claims 1 to 12, characterised in that the scissor mechanism (4) comprises scissor member pairs (5, 6) which are arranged one above the other and which have a common drive (11).
14. Scissor-type lifting table according to any one of claims 1 to 13, characterised in that special monitoring means are provided in order to monitor the operation, in particular in order to ensure a sufficient level of operational reliability, the monitoring means being able to comprise detectors which monitor the pulling force and/or detectors which directly monitor the pulling means (17), and, if a malfunction is detected, in particular damage to the pulling means (19) and/or the scissor mechanism (4), it being possible for the drive (11) to be able to be automatically switched off and the scissor mechanism (4) to be able to be locked or blocked in its position.
15. Scissor-type lifting table according to any one of claims 1 to 14, characterised in that the drive (11), in particular the drive (11) for the pulling means (19), is in the form of an electric motor and/or functions pneumatically or hydraulically and/or is associated with the lower frame (1).

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