192 clutches and power-stop control – Clutch and brake – Crank control
Reexamination Certificate
2001-09-12
2003-08-12
Bonck, Rodney H (Department: 3681)
192 clutches and power-stop control
Clutch and brake
Crank control
C192S015000, C192S223000
Reexamination Certificate
active
06604619
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority of International application number PCT/DE99/03676, filed Nov. 18, 1999, which in turn claims priority to German patent application number 198 55 282.8, filed Nov. 24, 1998.
FIELD OF INVENTION
The invention relates to a two-directional manual drive which produces a rotational movement. A drive of this kind is suitable in particular for manually adjusting the height or rake of a vehicle seat.
BACKGROUND OF THE INVENTION
A two-directional drive is known from DE 43 09 334 A1 wherein force transfer from a drive lever to a driven shaft takes place through friction locking elements which are mounted on the shaft. When the drive lever is moved away from the neutral position of the drive lever the friction locking elements clamp with the shaft and transfer torque introduced on the drive side to the shaft.
The friction locking elements thus have a friction-conditioned self-locking action when entering into the drive phase with the surface of the shaft which is to be driven. It is thereby ensured that the friction torque is intensified in dependence on the drive torque itself so that large forces can also be transferred. During the reverse movement of the drive lever back towards its neutral position the self-locking action is however lifted and the friction torque is kept as small as possible.
Controlling the conditions of the self-locking action is undertaken by an elastic switching element. Swivel movement of the drive lever beyond its neutral position leads to the expansion of the elastic switching element which is designed in particular as a shaped wire spring. The tangentially acting force which is thereby produced causes tilting and tensioning processes within the scope of the proposed play of the drive device so that the self-locking action can become active and intensified.
In the event of a return of the drive lever to the neutral position the one spring end of the elastic switching element exerts a tangential force on the friction locking elements through a bolt whereby this force acts in the swivel direction of the drive lever and lifts the self-locking properties so that the shaft is prevented from jamming and turning back.
From FR-A 2 750 186 a drive mechanism for producing a rotational movement is known which takes place starting from a neutral position of a drive lever which can pivot about a drive axis selectively in one or other rotational direction. A driven element is only turned when the drive lever is moved away from the neutral position whilst when the drive lever is moved into the neutral position the driven element is not displaced. In order to produce the rotational movement the driven element has internal teeth which interact with two locking pawls mounted on a fixed flange. A toothed segment-shaped disc which is able to swivel about a cam connected to the drive lever with diametric play has two driving pawls of which during activation of the drive lever the driving pawl corresponding to the direction of rotation of the drive lever, as well as the corresponding locking pawl, are brought into engagement with the internal teeth of the driven element whilst the other driving pawl and the locking pawl are kept out of engagement with the internal teeth of the driven element.
The known drive mechanism for producing a rotational movement is automatically locked after each operation of the drive lever so that no additional locking device is required which blocks torque on the driven side but transfers torque on the drive side arising from the drive lever to the device which is to be driven. When the drive lever returns to the neutral position the teeth of the driving pawls are brought out of engagement with the internal teeth of the driven element.
From WO 96 23672 A, a two-directional manual drive is known for producing a rotational movement by means of a drive lever which starting from a neutral position can pivot with restricted angle into one or other rotational direction, through which a shaft is rotated when the drive lever is moved away from its neutral position while the drive lever is pivoted in the direction of the neutral position the shaft is not displaced. The drive lever which is mounted on an axis is provided with swivel detent elements while the ends provided with teeth engage into the teeth arranged round the periphery of a drive wheel. A slide guide is associated with the detent elements and lifts each unloaded detent element out from the teeth of the drive wheel. Furthermore a locking device is connected to the drive shaft so that torque on the output side is blocked while torque on the drive side is transferred.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a two-directional manual drive for producing a rotational movement which enables infinite transfer of torque from a drive lever to a driven element, operates without play and noise and which can also be readily used, i.e. without greater demands on tolerance, as a locking clutch with a substantially matching construction with a two-directional drive mechanism and can, therefore, be manufactured cost-effectively.
According to one embodiment of the present invention, a driven element has a cylindrical shaped driving surface arranged concentric with a drive axis and on which bearing surfaces of coupling elements are placed in non-positive fit when the drive lever is rotated out of a neutral position. In this way the driven element is entrained in the direction of the periphery. When the drive lever is returned to the neutral position the coupling elements are released from a position of non-positive fit so that the driven element is no longer displaced as the drive lever is returned into the neutral position.
The solution has the particular advantage that it can be constructed without any spring-elastic switching element. In this way external factors, such as dirt or the like, have substantially little effect or even no effect whatsoever on the functioning of the drive according to the present invention so that proper functioning of the drive according to the present invention is always guaranteed. This also applies in the event of long-lasting and high strain on the drive.
The drive according to the invention preferably has circular section coupling elements which are placed against the cylindrical driving surface through bearing faces of their partially circular shaped surfaces which are opposite the cylindrical shaped driving surface of the driven element. With this embodiment advantageous that the formation of the bearing faces of the coupling elements matches the cylindrical shaped formation of the driving surface so that a particularly good force-locking or frictional engagement connection between the bearing faces of the coupling elements and the cylindrical drive face of the output element becomes possible.
In another preferred embodiment of the drive according to the invention a drive element is mounted between the coupling elements. Furthermore expanding flanks of the coupling elements are arranged at such a distance from the drive axis that a substantially radially aligned force produces the frictional engagement between the coupling elements and the cylindrical driving surface. In the event of the drive lever being moved out from its neutral position, the bearing faces of the coupling elements for transferring torque on the drive side adjoin with a frictional engagement against the cylindrical driving surface of the driven element.
In a further preferred embodiment the bearing faces of the coupling elements adjoin the cylindrical driving surface of the driven element elastically pretensioned by at least one spring element, for example a compression or leaf spring. The spring element thereby preferably bears against the coupling elements in the centre of at least one of the bearing faces and presses these apart from each other in the direction of the periphery until they bear on the drive element with their expanding flanks which are each turned remote from the spring element relative to
Scheck Georg
Schumann Peter
Bonck Rodney H
Brose Fahrzeugteile GmbH & Co. KG
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