EMERGENCY HAND CRANK DRIVE FOR A SHAFT THAT IS TO BE MADE TO ROTATE

Abstract

Emergency hand crank drive consisting of a load shaft that is to be made to rotate, and a crank arm hingedly connected to said load shaft, and a coupling piece on said load shaft and a catch, which is fixedly connected to said crank arm and which has a shape that is complementary to the shape of said coupling piece and which can be releasably connected to said coupling piece, whereby a rotary sliding piece is mounted on said load shaft in such a way as to be movable in the longitudinal direction of said load shaft and be rotatable around the longitudinal direction thereof and said crank arm is hingedly secured to said rotary sliding piece.

Claims

1. Emergency hand crank drive consisting of a load shaft (1) that is to be made to rotate, and a crank arm (2) hingedly connected to said load shaft (1), and a coupling piece (11) on said load shaft (1) and a catch (21), which is fixedly connected to said crank arm (2) and which has a shape that is complementary to the shape of said coupling piece (11) and which can be releasably connected to said coupling piece (11), wherein a rotary sliding piece (3) is mounted on said load shaft (1) in such a way as to be movable in the longitudinal direction of said load shaft (1) and be rotatable around the longitudinal direction thereof and said crank arm (2) is hingedly secured to said rotary sliding piece (3).

2. Emergency hand crank drive, according to claim 1, wherein said coupling piece (11) is arranged concentrically on said load shaft (1).

3. Emergency hand crank drive, according to claim 1, wherein a different external tool or a motor can be placed on said coupling piece (11) as an alternative to said crank arm (2).

4. Emergency hand crank drive, according to claim 1, wherein the travelling distance of said rotary sliding piece (3) on said load shaft (1) is limited by an inner stopper (41) close to the load and an outer stopper (42) which is remote from the load.

5. Emergency hand crank drive, according to claim 4, wherein a spring (5) is supported from said outer stopper (42) and said spring (5) presses said rotary sliding piece (3) against said inner stopper (41).

6. Emergency hand crank drive, according to claim 5, wherein the front side (32) of said rotary sliding piece (3), which faces said inner stopper (41), is corrugated and engages under the pressure of said spring (5) into the face (43) of said inner stopper (41), which is formed complementary to said front side (32), or said front side (32) and said face (43) are designed as a different type of torque-limited slip clutch.

7. Emergency hand crank drive, according to claim 1, wherein two gudgeons (31) are shaped onto said rotary sliding piece (3) and on said gudgeons (31) the two limbs (22) of a fork are pivotally mounted, whereby the centerpiece (23) of said fork carries said catch (21) and said centerpiece (23) is connected to said crank arm (2).

8. Emergency hand crank drive, according to claim 1, wherein said load shaft (1) drives the lifting drive of a vertical telescopic support of a semi-trailer or other vehicle trailer.

9. Emergency hand crank drive, according to claim 8, wherein the lifting drive is a transmission having a fixed ratio.

Description

[0024] In the following, further details and features of the invention are explained in more detail by means of an example. However, this example is not intended to limit the invention, but only to explain it. It is shown schematically:

[0025] FIG. 1: Cross section of an emergency hand crank drive with the fork connecting the load shaft (1) with the fork and the rotary sliding piece (3)

[0026] FIG. 2: as FIG. 1, but crank turned further by 90°

[0027] FIG. 3: as FIG. 2, but crank folded in

[0028] FIG. 1 shows from an emergency hand crank according to the invention only the end of the crank arm (2) and the therewith connected fork, which is connected to the load shaft (1). For the sake of clarity the largest part of the crank arm (2) and the attached handle are not plotted. Depicted is the active operating state of the emergency hand crank in which the catch (21), located inside of the tubular and angled end region of the crank arm (2), encompasses the coupling piece (11) of the load shaft (1).

[0029] Because in the illustrated embodiment the coupling piece (11) is integrally formed onto the end of the load shaft (1), the centerlines of the coupling piece (11), of the catch (21) and of the load shaft (1) are aligned.

[0030] In FIG. 1, the lateral flattening of the coupling piece (11) is marked with a diagonal cross. It is easy to understand that the catch (21), which is complementary to the coupling piece (11), can transmit a torque to the coupling piece (11) and thus further on to the load shaft (1).

[0031] Attached to the tubular end region of the crank arm (2) is a fork, which is graphically cut by its length. The two limbs (22) of the fork extend parallel to both sides of the load shaft (1). Into the end region of each limb (22) a bore is inserted. Into each bore a gudgeon (31) engages.

[0032] In FIG. 1 one can easily understand that the limbs (22) can be pivoted around the gudgeons (31). Thus the fork and the crank arm (2), which is attached to it, pivot also. The limbs (22) of the fork thus guide the crank arm (2) during the pivoting. In addition they also serve as a stabilization of the crank arm (2) in the operating state, by transferring forces onto the load shaft (1), which act vertically to the centerline of the hand crank.

[0033] FIG. 1 clearly shows that the rotary sliding piece (3) slides along the load shaft (1) and is pushed by the spring (5) in the direction of the inner stopper (41), whereby the spring (5) is resting on the outer stopper (42). On closer inspection it is to be seen that the rotary sliding piece (3) is still somewhat away from the inner stopper (41). Nevertheless even in this intermediate state torque can be transferred already from the crank arm (2) via the fork to the load shaft (1).

[0034] In FIG. 1 it is easy to understand, but not depicted that the rotary sliding piece (3) moves under the pressure of the spring (5) towards the inner stopper (41), so that the front side (32) of the rotary sliding piece (3) pretty soon will be pressed onto the face (43) of the inner stopper (41). FIG. 1 also not shows that the front side (32) and the face (43) are designed as a slip clutch, which transfers small and unwelcome torques from the load shaft (1) onto the rotary sliding piece and from there to the crank arm (2).

[0035] FIG. 2 shows the same operating state as in FIG. 1, but the crank arm (2) is rotated by 90° with respect to FIG. 1. Thus only one limb (22) from the fork on the crank arm (2) is visible, and only one gudgeon (31) on the rotary sliding piece (3) faces the observer. In this angular position of the crank arm (2), its bended end, which is fixedly connected to the fork, is particularly clearly recognizable.

[0036] In FIG. 3 can be seen the crank arm (2) and the fork attached thereto with its limb (22) from the same direction as in FIG. 2. The essential difference is that the emergency hand crank is folded down into a waiting position, so that the limbs (22) are now pivoted around the gudgeons (31). Due to the weight of the crank arm (2), which is shown here only partially, and the non-visible handle, the limb (22) has only pivoted out of the centerline of the load shaft (1) by about 65°. In FIG. 3 one can easily understand that the crank arm (2) can be pivoted further, as required, e.g. up to a holder.

[0037] The coupling piece (11) protrudes freely into the space so that an external drive, such as a motor, can be mounted thereon easily. By comparing FIG. 3 with FIG. 1 it is clear that the rotary sliding piece (3) does not move with a rotation of the load shaft (1), but slides on the load shaft (1), so that the limbs (22) and thus the entire emergency hand crank do not move.

[0038] In FIG. 3 it is clear that when the limbs (22) are pivoted back into the operating position, the rotary sliding piece (3) must be shifted on the load shaft (1) to the right against the force of the spring (5), i.e. away from the inner stopper (41), so that the catch (21), visible only in FIG. 1, will be moved in front of the coupling piece (11) and will be pressed thereon by the force of the spring (5).

[0039] In FIG. 3 it is obvious that the spring (5) presses the front side (32) of the rotary sliding piece (3) against the face (43) of the inner stopper (41). Not depicted is in FIG. 3, that the front side (32) and the face (43) are designed as a slip clutch. In the case of a very small, undesired, disturbing torque from the load on the load shaft (1), this slip clutch derives the disturbing torque on the rotary slide (3). From there, it is guided onto the limbs (22) and further onto the crank arm (2). When the crank arm (2) is fixed in the position of FIG. 3 by means of a device—not shown here—an undesired rotation of the load shaft (1) due to the undesired disturbance torque is prevented.

LIST OF REFERENCE SIGNS

[0040] 1 load shaft [0041] 11 coupling piece on load shaft 1 [0042] 2 crank arm [0043] 21 catch, connected with crank arm 2 [0044] 22 limb of a fork on crank arm 2 [0045] 23 centerpiece of the fork on the crank arm 2 [0046] 3 rotary sliding piece, can be pivoted and shifted on load shaft 1 [0047] 31 gudgeon on rotary sliding piece [0048] 32 front side of rotary sliding piece [0049] 41 inner stopper on load shaft 1 for rotary sliding piece 3 [0050] 42 outer stopper on load shaft 1 for rotary sliding piece 3 [0051] 43 face of the inner stopper 41 [0052] 5 spring, rests on outer stopper 42, pushes the rotary sliding piece 3 towards the inner stopper 41