DE20200409U1 - Locking device based on a rotary push-push movement principle - Google Patents

Description

Patent Attorney Dipl.-Ing. Lambert Eichelbaum

D-45659 Recklinghausen Krüppeleichen 6

Telephone: (02361) 21091-2 · Fax: (02361) 22949 . E-mail: pa@eichpatent.de

07.01.2002 eig 2870a/01

Applicant:

Eigler procon GmbH

Höh 1,D- 58540 Meinerzhagen

"Locking device based on a rotary push-push movement principle"

Description:

The invention relates to a locking device according to the push-push movement principle for locking a locking device for a lid, a flap, a compartment, a door, a cover or a similar object, which is pressed into a closing locking position after one force actuation and into an open locking position after a further force actuation in the same direction of force by exerting a force ω against the effect of the force of a pre-tensioned locking spring.

A locking device of this type is known from DE 199 42 956 A1. This device has, within the guide surfaces of a plate-shaped locking body which is guided linearly in slots, a pin which is coupled to a door and which is guided linearly against the effect of a pre-tensioned locking spring. The pin contacts several guide surfaces in a specific cycle before reaching its closed locking position. To reach its open locking position, it is actuated again in the same direction of force against the effect of a locking spring (not shown) before again reaching its open locking position after a specific cycle of the guide surfaces. This locking device has the disadvantage of high overpressure, i.e. the path measured from the open position of the object to be locked to its locking position is relatively long. A particular disadvantage is the thin pin which, in the event of incorrect operation, e.g.

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when the object is lifted from its closed position, it can break off in this locking position. On the other hand, due to the linear guide principle and to achieve the lowest possible overpressure, the pin must only be provided with the smallest possible cross-sectional area, because otherwise the size of the plate-shaped locking body increases accordingly. Another disadvantage is the relatively large length of the locking body in conjunction with the guide pin.

&iacgr;&ogr; Other known locking devices of the type mentioned

The locking devices of the type mentioned, which cannot currently be documented in writing, work with a heart-shaped control curve inside or outside a slot, with locking positions along which a guide pin slides. These locking devices are also linked to the disadvantages mentioned above and have low mechanical stability due to the guide pin having to be kept as small as possible in cross-section.

The relatively long path required to overpress the locking devices has proven to be particularly problematic.

Starting from this closest prior art, the object of the invention is to create a locking device of the type mentioned at the outset which, with a small installation space and minimal overpressure, has such a high mechanical stability that even in the event of incorrect operation, only a predetermined movement sequence with defined forces that do not lead to destruction occurs.

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This complex problem is solved according to the invention in conjunction with the generic term mentioned at the beginning in that the locking device is formed by a shaft which can be rotated in bearings of a stationary base body, the tumbler arranged thereon in a rotationally fixed manner, a locking cam wheel which can be rotated thereon and a stepping detent coupled to the shaft in a rotationally fixed manner, as well as by a locking lock which can be pivoted on an axis which is also fastened to the base body and which, in the open locking position, is held with its broad locking surface in a raised position on a cam of the locking cam wheel against the action of a locking lock spring and, in the closed locking position, comes into contact with a broad support surface of the tumbler under the action of the tumbler spring, wherein the locking cam wheel is prevented from rotating in the direction of the open locking position of the tumbler by a pawl lock arranged on the base body and is provided with a stepping detent toothing in its area facing away from the tumbler, in which a leaf spring-like locking projection of the stepping detent engages.

It is understood that the kinematic reversal, namely the base body being movable and the locking bracket being stationary, is also covered by the scope of protection of claim 1.

This design creates a locking device that no longer works linearly, but rather rotary, with minimal installation space, which, due to the wide locking surface of the locking device and the equally wide support surface of the locking device, has such high mechanical stability that even with high surface pressures, e.g. as a result of

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Incorrect operation means that the locking device can hardly be destroyed under the forces to be taken into account here, but the specified rotary movement sequence with defined forces for opening and closing must be maintained. In a departure from the linear movement according to the state of the art, not only is a minimal installation space size achieved, but also an equally minimal overpressure.

This overpressure can be freely selected depending on the intended use of the locking device with regard to the number of locking cams of the locking cam wheel in relation to the step locking teeth, whereby a favorable ratio is 1 : 2, ie that twice the number of step locking teeth is allocated to the number of cams.
15

The stable ratchet lock arranged on the base body prevents the locking cam wheel from rotating in the direction of the open locking position, which could otherwise lead to incorrect operation. This means that the locking cam wheel can only rotate in one direction.

The base body advantageously has two spaced-apart bearing eyes for receiving the shaft and two spaced-apart bearing eyes for receiving the axle for the locking lock that can be pivoted thereon, with the longitudinal axes of symmetry of the shaft and axle running parallel to each other. Furthermore, the base body is provided with a leaf spring-like ratchet lock below the locking cam wheel, which, under the effect of its own spring preload, slides into the recess between two cams in one direction of rotation of the locking cam wheel and in its

other direction of rotation. This ratchet lock can be manufactured as a separate part or directly connected to the base body.

According to an advantageous development of the invention, the locking device arranged on the shaft in a rotationally fixed manner is provided on its outer circumference with two projecting jaws for coupling a locking bracket connected to the object to be locked. These jaws can be designed as spring clips or can be replaced by a joint connected to the locking bracket. The choice of design depends on the intended use of the locking device.

According to a particularly advantageous development of the invention, the locking spring, designed as a torsion spring, is arranged on the shaft between one bearing eye of the shaft and the facing front side of the locking device, with one leg of the locking spring resting on a projection of the front side and the other leg on the stationary base body. This ensures an effective force effect on the locking device despite the small size.

This locking device is advantageously provided with a wide support surface on its other end face in a recess, the radial extension of which ends below the circle of the surface of the cams of the adjacent locking cam wheel. Since this large support surface can extend over a relatively large part of the circumference of the locking device, it has such a high stability that it cannot be broken off under any incorrect operating forces - in

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In contrast to the thin pen as in the state of the art, this is excluded.

The locking cam wheel can be rotated relative to the locking mechanism and the stepping detent on the shaft and is provided with stepping detent teeth on the face facing the stepping detent. This also allows its radial size to be kept small.

According to a particularly advantageous development of the invention, when the guard is actuated into the open locking position, the stepping detent, which is fixed in rotation on the shaft and can be rotated together with the guard, rotates the locking cam wheel by one step in its one possible direction of rotation via its leaf spring-like locking projection and at the same time pushes the locking lock with its broad locking surface up onto the surface of the locking cam closest in the direction of rotation, counter to the effect of the locking lock spring, while simultaneously releasing the support surface of the guard. As a result, the broad locking surface of the locking lock and the broad support surface of the guard are disengaged, allowing the guard to pivot into its open locking position under the effect of its locking spring. This locking lock spring is also designed as a torsion leg spring, which is supported with one leg on the locking lock and with the other leg on the base body.

The stepping detent can either be coupled directly to the shaft in a rotationally fixed manner or can be rotated in the direction of rotation of the locking cam wheel against the action of a spring via a driver disk coupled to the shaft in a rotationally fixed manner with a driver projection, which pre-tensions the stepping detent in

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This design is suitable for cases where a free movement of the stepping gear is desired. It is not necessary for the implementation of the operating principle mentioned in claim 1. 5

The spring acting on the step rest is also designed as a torsion spring and is supported with one leg on the step rest and with its other leg on the base body.

For cost-effective production, the base body, the locking bracket, the locking mechanism, the locking cam wheel, the stepping detent, the drive plate and the locking lock are made of plastic, namely PA, POM, ABS, PC or PEEK, whereas the torsion springs are made of hardened spring steel.

Depending on the intended use and the associated load, the shaft and axle are made of steel or plastic.

An embodiment of the invention is shown in the drawings.

Fig. 1 is a perspective view of a cover with a locking bracket which is held in the closed position by a locking device,

Fig. 2 shows the cover of Fig. 1 with the locking bracket released from the locking device in the open locking position,

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Fig. 3 a cover provided with a locking bracket at three different points, which is held in its closed position by three synchronously interacting locking devices,

Fig. 4 shows the view of the cover of Fig. 3 in an open locking position released from the locking device,

Fig. 5 the perspective view of the locking device in connection with a locking bracket,

Fig. 6 is a perspective view of the locking device of Fig. 5 approximately in the direction of arrow VI of Fig. 5, 15

Fig. 7 is an exploded view of the individual parts of the locking device of Fig. 6,

Fig. 8 is a vertical plan view of the exploded view in the direction of arrow VIII of Fig. 7,

Fig. 9 is a perspective view of the exploded view of Fig. 8,

Fig. IO the side view of the individual parts of the exploded view in the direction of arrow X of Fig. 8,

Fig. 11 is a perspective view of the base body, shaft, locking spring and locking bracket of Fig. 5,

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Fig. 12 the perspective view of the guard locking device as a single part,

Fig. 13 the perspective view of the locking mechanism of Fig. 12 approximately in the direction of arrow XIII,
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Fig. 14 the individual representation of the guard locking in connection with the guard locking bracket approximately in the direction of arrow XIV of Fig. 6,

Fig. 15 the view of the locking mechanism of Fig. 14 in the direction of arrow XV,

Fig. 16 the perspective partial view of the locking cam wheel with the locking mechanism arranged behind it and the engaging locking lock of Fig. 6 with the stepping detent and driver plate removed,

Fig. 17 the individual perspective view of the step catch of Fig. 6,

Fig. 18 the view of Flg. 16 with step catch placed on the shaft,

Fig. 19 is a partial perspective view of Fig. 18 with the stepping detent removed from the shaft and the stepping detent teeth removed from the cams of the detent cam wheel in conjunction with the engaging detent lock,

Fig. 20 the perspective partial view of the locking mechanism of Fig. 19 with the cams of the locking cam wheel removed and

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Fig. 21 the view of Fig. 20 without locking mechanism,

Fig. 22 the perspective partial view in the direction of arrow XXII of Fig. 5 of the underside of the drive plate and the step catch and

Fig. 23 is a partial view in the direction of arrow XXIII of Fig.

In the figures, only one embodiment of the locking device 1 is shown. All identical parts are therefore designated with the same reference numerals.

In Figures 1 and 2, a lid 16 provided with a locking bracket 4 is brought into and out of engagement with the locking device 1. This lid can thereby close a container (not shown), a compartment, cover or the like as desired. For this purpose, the lid 16 of Fig. 2 is pressed down in the direction of arrow C (C for closing) with its locking bracket 4 towards the locking device 1 until it has reached the closed position of Fig. 1. After a further force actuation according to arrow O (O for opening) in the same direction, the lid 16 is again released from the locking device 1 and transferred to its open locking position according to Fig. 2.

In Figures 3 and 4, a relatively long cover 16 with a total of three locking devices is held by a total of three locking brackets 4, of which at least one must correspond to the locking device 1 according to the invention. The others only need the locking device 3 with the

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Driving jaws 26, 27. So that the movement of three locking devices 1 is synchronous, they are connected by a common shaft 8. Here too, closing takes place by pressing the lid 16 down in the direction of arrow C towards the three locking devices 1 according to Fig. 4. As soon as the three retaining brackets 4 are gripped by the locking device and moved into their closed position, the lid 16 has closed the container (not shown), the compartment and another hollow space. After another force is applied in the same direction of the arrow according to arrow O in Fig. 3, the locking devices 1 are moved into their open position so that the lid 16 can be automatically pivoted into the desired opening width by a spring/gear mechanism (not shown).

In Figures 5 to 10, the locking device 1 is shown in all its individual parts. It consists of a base body 2 with two bearing eyes 12, 13 for the shaft 8 and two further bearing eyes 14, 15 for receiving the axle 10.

According to Fig. 5, the pre-tensioned locking spring 3a, the locking device 3, the locking cam wheel 5, the stepping detent 6 with the leaf spring-like projection 6b, the stepping detent spring 6a and the driving disk 9 with driving projection 9a (see Fig. 22) are arranged on the shaft 8 from left to right. In the present case, the locking device 3 and the driving disk 9 are arranged on the shaft 8 in a rotationally fixed manner and can only be rotated together in one direction or the other. The stepping detent 6 is arranged rotatably on the shaft 8, but is prevented from rotating by the driving projection 9a of the

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Driving disk 9 is prevented. The expression "rotatably fixed" in claim 1 therefore also includes such equivalent embodiments. The locking cam wheel 5 is freely rotatably mounted on the shaft 8, but can only be rotated in the direction of the arrow because it is prevented from rotating in the opposite direction of the arrow by the stable pawl lock 11 shown in Fig. 8, which is arranged in a fixed position on the bottom of the base body 2.

The axle 10, which is advantageously pressed with its two knurled ends into the bearing eyes 14, 15, only accommodates the locking device 7 and the locking device spring 7a. Both can be rotated on the axle 10. However, the locking device spring 7a, under its pre-tension, always presses the locking device 7 with its locking surface 24 down in the direction of the locking cam wheel 5.

All springs 3a, 6a and 7a are designed as torsion springs. The tumbler spring 3a is supported with one leg 3b on the base body 2 and with its other leg 3c on a projection 18 of the tumbler 3.

The stepping rest spring 6a is supported with one leg 6c on the base body 2 and with its other leg 6d on the stepping rest 6.

Likewise, the locking spring 7a is supported with one leg 7b on the base body 2 and with its other leg 7c on a projection 19 of the locking device 7. As a result, the locking device 7 is always pressed downwards in the direction of the arrow 17.

On the other hand, the locking spring 3a always tries to keep the locking mechanism 3 in

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Direction of arrow 20 in an opposite swivel direction.

As can be seen in particular from Figures 7, 8 and 9, the locking cam wheel 5 has locking cams 21 on one side and the teeth 22 of the step locking toothing 23 on the other side. The teeth 22 interact with the leaf spring-like projection 6b of the step locking mechanism 6, whereas the cams 21 rounded in the direction of arrow 17 with their straight surfaces tapering radially towards the shaft 8 interact with part of the broad locking surface 24 of the locking lock 7. Since the locking spring 7a always strives to pivot the locking lock 7 in the direction of arrow 17 about the axis 10, part of the broad locking surface 24 engages in the space between two cams 21 in a locking manner. However, when the locking cam wheel 5 has been moved by the projection 6b of the stepping detent 6 by one step, i.e. by one tooth width, further in the direction of the arrow 17, the wide locking surface 24 is raised onto the surface 21a of the next locking cam 21 against the force of the pre-tensioned locking spring 7a. In this position, the wide support surface 25 (see Fig. 7) of the tumbler 3 can move under the wide locking surface 24 of the locking lock 7 and thus be rotated by the pre-tension of the tumbler spring 3a with the shaft 8 into its open locking position.

As can be seen in particular from Fig. 7, both the locking surface 24 of the locking mechanism 7 and the support surface 25 of the locking mechanism 3, which interacts with it in the closed locking position, are designed to be relatively wide, so that they can also absorb correspondingly high surface pressures.

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They can also absorb correspondingly high torques, e.g. in the event of incorrect operation, without the locking surface 24 or the support surface 25 breaking.

As shown in Figures 12 and 13, the locking mechanism 3, which is arranged on the shaft 8 in a rotationally fixed manner, is provided on its outer circumference with two projecting jaws 26, 27 for coupling the locking bracket 4 connected to the object 16 to be locked. These jaws 26, 27 can be designed as spring clips, as open arms or as a joint.

The radial extension of the broad support surface 25 of the locking mechanism 3 to the shaft 8 is dimensioned such that it ends below the circle of the surfaces 21a of the cams 21 of the locking cam wheel 5. Otherwise, the support surface 25 could not move under the broad locking surface 24 of the locking lock 7 in the open locking position.

Figures 14 to 17, which are self-explanatory, show details of the locking mechanism 3 as well as the locking device 7 and the stepping notch 6. The same applies to Figures 20 to 23, which show details of the locking mechanism 3 in connection with the locking device 7 (Figures 20 and 21) as well as the driving disk 9 in connection with the stepping notch 6 (see Figures 22 and 23) in different perspectives.

The function of the locking device 1 is described below with reference to Figures 18 and 19. It is assumed that the cover 16 is in its open position according to Figure 2. If the cover 16 is now in

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Direction of arrow C in Fig. 2, after the opening stroke the locking bracket 4 hits the jaw 27 of the locking device 3, whereby the locking device 3 is given a rotational movement in the direction of arrow 17. In the open position, the wide locking surface 24 of the locking lock 7 rests on the surface 21a of a cam 21. Due to the rotational movement of the locking device 3 in the direction of arrow 17, the stepping detent 6, which is coupled to the shaft 8 in a rotationally fixed manner, is also rotated in the direction of arrow 17, whereby the locking cam wheel 5 is rotated by one step, i.e. by one tooth 22 of its

&iacgr;&ogr; step locking teeth 23, is rotated further. As a result, the relevant cam 21 supporting the wide locking surface 24 also rotates in the direction of arrow 17 by, for example, half a cam width, so that the locking lock 7, which is under the effect of the locking spring 7a, engages in the direction of arrow 17 in the subsequent space between the locking cam 21 and thus prevents the tumbler 3 from rotating in the direction of arrow 20. If a force is again exerted on the object 16 in the direction of arrow O in this closed locking position, the tumbler 3 is rotated in the direction of arrow 17 and at the same time the locking lock 6 with its leaf spring-like projection 6a engaging in the step locking teeth is also rotated further. During this rotation, the cam 21 of the locking cam wheel 5 also rotates. On its surface 21b, which is rounded in the direction of rotation of arrow 17, the broad locking surface 24 now slides upwards against the force of the locking spring 7a until it rests on the surface 21a of the next cam 21. In this position, the broad support surface of the tumbler 3 can move under the broad locking surface 24 of the locking device and thus pivot into its open position in the direction of arrow 20 under the action of the locking spring 3a.

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During this pivoting in the direction of arrow 20, the stepping detent 6, which is arranged on the shaft 8 in a rotationally fixed manner with the locking mechanism 3, is also rotated, whereby the leaf spring-like projection 6a engages in the next tooth gap of the stepping detent toothing 23. The locking cam wheel 5 cannot participate in this pivoting movement in the direction of arrow 20 because it is prevented from doing so by the pawl lock 11 (see Fig. 8) arranged stationary on the base body 2. The locking bracket 4 can now slide out of the space between the jaws 26, 27 and, with the cover 16 connected to it, can once again assume its open position as shown in Fig. 2 or 4.

If the cover 16 is then pressed down again in the direction of arrow C with the locking bracket 4, it again contacts the jaw 27, thereby setting the locking device 3 into a rotary movement in the direction of arrow 17, whereby the stepping detent 6 with its leaf spring-like projection 6a moves the locking cam wheel 5 forwards via the stepping detent teeth 23 and then the locking lock 7 with its broad locking surface 24 again dips into a gap between two cams 21 under the action of the locking lock spring 7a, whereby during the subsequent pivoting movement of the locking device 3 under the action of its locking spring 3a in the direction of arrow 20, the broad support surface 25 moves against the broad locking surface 24 of the locking lock 7 and the closed locking position is thus reached.

Advantageously, the base body 2, the locking bracket 4, the locking mechanism 3, the locking cam wheel 5, the stepping latch 6, the

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The drive plate 9 and the locking mechanism 7 are made of plastic, such as PA, POM, ABS, PC or PEEK, whereas the torsion springs 3a, 6a, 7a are made of hardened spring steel.

The shaft 8 and the axle 10 can be made of steel or plastic depending on the application and load.

List of reference symbols:

Locking device 1

Base body 2

Locking 3

Locking spring 3a

Legs of the locking spring 3a 3b, 3c

Locking bracket 4

&iacgr;&ogr; locking cam wheel 5

Step rest 6

Step rest spring 6a

leaf spring-like projection 6b

Leg of the stepping spring 6a 6c, 6d

Lock 7

Locking spring 7a

Leg of the detent locking spring 7a, 7b, 7c

Wave 8

Drive plate 9

Driving lead 9a

Axis 10

Latch lock 11

Bearing eyes 12, 13, 14,

Lid 16

Projection of the locking mechanism 3 18

Locking mechanism projection 7 19

Locking cam 21

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Surfaces of the locking cam 21 21a, 21b Teeth 22 Step locking teeth 23 Restricted area 24 5 Support surface 25 Bake 26, 27 Pfeüe C, O, 17, 20

Claims (16)

1. Locking device according to the push-push movement principle for locking a locking device for a lid, a flap, a compartment, a door, a cover or a similar object, which is pressed into a closed locking position by exerting a force counter to the effect of the force of a pre-tensioned locking spring during one force actuation and into an open locking position after a further force actuation in the same direction of force, characterized in that the locking device ( 1 ) is formed by a shaft ( 8 ) which can be rotated in bearings ( 12 , 13 ) of a stationary base body ( 2 ), the locking device ( 3 ) arranged thereon in a rotationally fixed manner, a locking cam wheel ( 5 ) which can be rotated thereon and a stepping detent ( 6 ) coupled to the shaft ( 8 ) in a rotationally fixed manner, as well as by a locking lock ( 7 ) which can be pivoted on an axis ( 10 ) which is also fastened to the base body ( 2 ), which in the open locking position, it is held in a raised position on a cam ( 21 ) of the locking cam wheel ( 5 ) with its broad locking surface ( 24 ) against the action of a locking spring ( 7a ), and in the closed locking position it comes into contact with a broad support surface ( 25 ) of the tumbler ( 3 ) under the action of the tumbler spring ( 3a ), the locking cam wheel ( 5 ) being prevented from rotating in a direction (arrow 20 ) in the direction of the open locking position of the tumbler ( 3 ) by a pawl lock ( 11 ) arranged on the base body ( 2 ) and being provided on its area facing away from the tumbler ( 3 ) with a step locking toothing ( 23 ) into which a leaf spring-like locking projection ( 6b ) of the step detent ( 6 ) engages. 2. Locking device according to claim 1, characterized in that the base body ( 2 ) has two spaced-apart bearing eyes ( 12 , 13 ) for receiving the shaft ( 8 ) and two spaced-apart bearing eyes ( 14 , 15 ) for receiving the axis ( 10 ) for the locking device ( 7 ) pivotable thereon, the longitudinal axes of symmetry of the shaft ( 8 ) and the axis ( 10 ) running parallel to one another. 3. Locking device according to claim 1 or 2, characterized in that the base body ( 2 ) below the locking cam wheel ( 5 ) is provided with a leaf spring-like pawl lock ( 11 ) which, under the effect of its own spring preload, engages in the recess between two cams ( 21 ) in a sliding manner in one direction of rotation (arrow 17 ) of the locking cam wheel ( 15 ) and in a locking manner in its other direction of rotation (arrow 20 ). 4. Locking device according to one of claims 1 to 3, characterized in that the locking device ( 3) arranged in a rotationally fixed manner on the shaft (8 ) is provided on its outer circumference with two projecting jaws ( 26 , 27 ) for coupling a locking bracket ( 4 ) connected to the object to be locked ( 16 ). 5. Locking device according to claim 4, characterized in that the jaws ( 26 , 27 ) are designed as spring clips. 6. Locking device according to one of claims 1 to 5, characterized in that the tumbler spring ( 3 a) designed as a torsion spring is arranged on the shaft ( 8 ) between the one bearing eye ( 12 ) of the shaft ( 8 ) and the facing end face of the tumbler ( 3 ) and is supported with its one leg ( 3 c) on a projection ( 18 ) of the end face and with its other leg ( 3 b) on the stationary base body ( 2 ). 7. Locking device according to one of claims 1 to 6, characterized in that the tumbler ( 3 ) is provided on its other end face in a recess ( 3d ) with the broad support surface ( 25 ), the radial extension of which ends below the circle of the surface ( 21a ) of the cams ( 21 ) of the adjacent locking cam wheel ( 5 ). 8. Locking device according to one of claims 1 to 7, characterized in that the locking cam wheel ( 5 ) is rotatable relative to the locking device ( 3 ) and the stepping detent ( 6 ) on the shaft ( 8 ). 9. Locking device according to one of claims 1 to 8, characterized in that the locking cam wheel ( 5 ) is provided with the step locking toothing ( 23 ) on its end face facing the step locking device ( 6 ). 10. Locking device according to one of claims 1 to 9, characterized in that the step catch ( 6 ) arranged on the shaft ( 8 ) in a rotationally fixed manner and rotatable together with the tumbler ( 3 ) rotates the locking cam wheel ( 5 ) in its one possible direction of rotation (arrow 17 ) by one step via its leaf spring-like locking projection ( 6b ) when the tumbler ( 3 ) is actuated into the open locking position (arrow 17 ) and thus pushes the locking lock ( 7 ) against the action of the locking lock spring ( 7a ) with its broad locking surface ( 24 ) up onto the surface ( 21a ) of the locking cam ( 21 ) closest in the direction of rotation (arrow 17 ), releasing the support surface ( 25 ) of the tumbler ( 3 ). 11. Locking device according to one of claims 1 to 10, characterized in that the locking spring ( 7 a) is also designed as a torsion spring which is supported with its one leg ( 7 b) on a projection ( 19 ) of the locking device ( 7 ) and with its other leg ( 7 c) on the base body ( 2 ). 12. Locking device according to one of claims 1 to 11, characterized in that the step catch ( 6 ) can be rotated via a driver disk ( 9 ) coupled to the shaft ( 8 ) in a rotationally fixed manner with a driver projection ( 9a ) in the one possible direction of rotation (arrow 17 ) of the locking cam wheel ( 5 ) against the action of a spring ( 6a ) which holds the step catch ( 6 ) under prestress in contact with the driver projection ( 9a ). 13. Locking device according to claim 12, characterized in that the spring ( 6 a) is designed as a torsion spring which is supported with its one leg ( 6 d) on the step catch ( 6 ) and with its other leg ( 6 c) on the base body ( 2 ). 14. Locking device according to one of claims 1 to 13, characterized in that the pitch of the cams ( 21 ) and the pitch of the step locking toothing ( 23 ) with its teeth ( 22 ) are in the ratio of 1:2 and a tooth ( 22 ) of the step locking toothing ( 23 ) is arranged between two adjacent flanks of two cams ( 21 ). 15. Locking device according to one of claims 1 to 14, characterized in that the base body ( 2 ), the locking bracket ( 4 ), the locking device ( 3 ), the locking cam wheel ( 5 ), the stepping detent ( 6 ), the driver disk ( 9 ) and the locking lock ( 7 ) are made of plastic, namely PA, POM, ABS, PC or PEEK, and the torsion springs ( 3a , 6a , 7a ) are made of hardened spring steel. 16. Locking device according to one of claims 1 to 15, characterized in that the shaft ( 8 ) and the axle ( 10 ) are made of steel or plastic depending on the area of application and load.