AU756067B2

AU756067B2 - Lever unit

Info

Publication number: AU756067B2
Application number: AU65390/99A
Authority: AU
Inventors: Daniel Gerard Kunkel
Original assignee: Fico Cables SA
Current assignee: Fico Cables SA
Priority date: 1998-12-22
Filing date: 1999-12-21
Publication date: 2003-01-02
Anticipated expiration: 2019-12-21
Also published as: DE19859496B4; JP2000229560A; AU6539099A; DE19859496A1

Description

S&F Ref: 487772

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

*9 C

C

Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: The following statement is a full performing it known to me/us:- Fico Cables C/de Josep Pujol s/n.

Rubi 08191 Barcelona Spain Daniel Gerard Kunkel Spruson Ferguson St Martins Tower 31 Market Street Sydney NSW 2000 Lever Unit description of this invention, including the best method of 5845c Lever Unit 1. Technical field: The present invention relates to a lever unit with a security mechanism, in particular for the use in a parking brake of a vehicle.

2. The prior art Lever units are used in many fields of technology for operating Bowden cables or similar control elements. In the automotive field for example gear shifts and parking brakes are often operated by levers and connected Bowden cables. In particular in the case of the latter a security mechanism is typically provided at the lever unit allowing for example by means of a detent pawl and corresponding teeth a movement of the lever in one direction (for applying the brake), whereas the opposite movement is hindered. Thereby, the brake can be fixed in the applied position (for example during parking) and an unintended release of the brake is avoided.

For an intended release of such a parking brake a button is typically provided at the end of the lever so that the lever can be moved in all directions, once the button is pressed. This is achieved by a release of the security mechanism caused by the pressing of the button, for example by lifting the detent pawl from the teeth so that the lever can freely move as long as the button remains pressed.

However, if the button at the end of the lever is unintentionally pressed, the brake might be in spite of the security mechanism be released with possibly terrible consequences (rolling away of the vehicle on an inclined road and subsequent collision with other vehicles). Such a situation may easily arise when children or animals are left for a short time unsupervised in the vehicle or if a heavy blow caused by a sudden movement of a person unintentionally hits the button at the upper end of the lever.

It is therefore the problem of the present invention to provide a lever unit with a security mechanism which effectively prevents unintended movements of the lever in one direction, or at least provides useful alternative to existing lever units.

Summary of the Invention The present invention provides a lever unit, in particular for a parking brake of a motor vehicle, with a lever and a security mechanism, wherein the security mechanism comprises: a. an operating element; b. a releasable ratchet mechanism which blocks a movement of the lever into a first direction and which is unloaded by a movement of the lever into a second direction; c. a transmitting element for transmitting the movements of the operating element onto the ratchet mechanism; a first spring element arranged between the operating element; and the 15 transmitting element which is loaded or unloaded by the operation of the operating element, wherein S: e. the spring element provides in the loaded state a force onto the transmitting element which is not sufficient to release the ratchet mechanism to move the lever into the first direction; and f. the operating element and the spring element are arranged in-side a bushing inside the lever.

The preferred embodiment relates to a lever unit, in particular for the use in a parking brake of a vehicle with a lever and a security mechanism comprising an actuator, releasable locking mechanism blocking a movement of the lever in a first direction which is relieved by a movement of the lever in a second direction, a transmitting element for transmitting the movements of the actuator to the locking mechanism and a first spring element arranged between the actuator and the transmitting element, which is loaded or unloaded by the operation of the actuator, wherein the spring element exerts in the loaded state a force on the transmitting element, which is not sufficient to release the locking mechanism for a movement of the lever in the first direction.

Due to the spring element arranged between the actuator and the transmitting element the locking mechanism can only be released, if it is simultaneously unloaded by an additional movement of the lever into the second direction. Thus, the locking mechanism is only ST -2- -2- [R:\LIBD]03000.doe:can released similar to a children security cap for drugs by a combined movement of the lever on the one side and the actuator on the other side.

As a result, an incidental pressure on the actuator without the simultaneous unloading of the locking mechanism by a movement of the lever, only causes an elastic deflection of the spring element. In case of a use in a parking brake of a vehicle an unintended release of the parking brake can thus effectively be prevented.

The locking mechanism preferably comprises a detent pawl and a plurality of blocking teeth and the transmitting element is formed as a rod serving to move the detent pawl with respect to the blocking teeth. Further, preferably a second spring element is provided to bring the actuator after its operation back onto its starting position and to bias the detent *pawl in the direction of the blocking teeth.

i OF -2a- 7

-D*

[R:\LIBD]03000.doc:caa Further measures for the improvement of the lever unit according to the invention are the subject matter of further dependent claims.

4. Short description of the drawing In the following detailed description a presently preferred embodiment of the present invention is described with reference to the drawing which shows: Fig. 1: A view of the lever unit according to the invention in a parking brake of a vehicle; Fig. 2: An enlarged representation of the lever of the lever unit of Figure 1.

4. Detailed description of the invention In the following a preferred embodiment of the lever unit according to the invention in a parking brake of a vehicle is described. However, it is to be understood that the lever unit can S 20 also be used in other fields of technology.

S With reference to Figure 1 the lever unit according to the invention comprises a lever 1 which is pivotally mounted by a pivot 61 to a support 60. A Bowden cable 70 for the operation of brakes mounted to the wheels of the vehicle is operated by means of the lever 1. The details i 25 of the connection of the Bowden cables 70 and the support of the lever 1 are well-known to a person skilled in the art and are therefore not discussed in the following.

When the lever 1 is pulled in the direction of the continuous arrow in Figure 1 (against the force provided by the brakes) a detent pawl 20 slides with a tip 21 over a fixed surface provided with blocking teeth 25. When the lever 1 no longer moves the detent pawl 20 engages the blocking teeth and thereby prevents a movement of the lever 1 in the opposite direction of the continuous arrow in Figure 1 (and thereby prevents the release of the parking brake). The detent pawl 20 is to this end PivotTable mounted on a pivot 22.

To provide a secure engagement with the corresponding blocking teeth 25 the detent pawl is counter clockwise biased in the direction of the dashed arrow by a tension transmitted by the rod 30. The rod 30 comprises to this end a hook-like end 31 engaging a corresponding recess 24 of the detent pawl 20 and thus transforms pulling or pushing movements of the rod 30 parallel to the dashed arrow in Figure 1 into rotating movements of the detent pawl. Alternatively also another flexible connection between the rod and the detent pawl is conceivable, for example by means of a small pivot mounted to the detent pawl and cooperating with a corresponding eyelet at the end of the rod As soon as the lever 1 is no longer moved in the direction of the continuous arrow, the detent Spawl 20 contacts the upper flank of a blocking tooth 25 and engages due to the bias the recess between this tooth and the adjacent tooth. In the engaged state the detent pawl resists a clockwise torque due to the pulling load onto the lever I (caused by the brakes of the vehicle and transmitted by the Bowden cable 70) so that the rod 30 cannot be moved in the direction 20 opposite to the dashed arrow. Only if the lever I is pulled the release of the detent pawl Sallows a movement of the rod 30 in the direction opposite to the dashed arrow to completely detach the detent pawl 20 from the blocking teeth In the following the parts of the lever unit arranged in the front part of the lever are discussed 25 with reference to the detailed drawing in Figure 2.

Inside the lever 1 a cartridge 2 is positioned in which an actuating button 10 is slideably arranged. The actuating button comprises a lower part 14 and an upper part 13 which are for assembly detachably connected by connecting elements 12 and which form together a cavity in which a spring 40 is arranged. Behind the inner end of the actuating button 10 a second spring 50 is arranged which is elastically compressed under sliding movement of the actuating button 10 to the inside. Instead of the two springs also elastomeric elements can be used.

The second spring 50 is on the opposite side with respect to the actuating button fixed to the cartridge 2 by means of a mounting 51.

The transmitting elements in the form of a rod 30 extends through the windings of the second spring 50 and an opening between the upper and the lower part of the actuating button 10. It terminates in a disk-like end 31 which is in direct contact with the first spring 40. Simultaneously the backside of the disk-like end 31 contacts the inner ends of the upper and the lower part 13, 14, respectively, of the actuating button 10. Since the actuating button 10 is pushed by the second spring 50 to the outside (in the direction of the dashed arrow) a tension is caused in the same direction on the rod 30 for providing the above mentioned counter clockwise bias of the detent pawl 20. When the actuating button 10 is pressed with an engaged detent pawl 20 without a simultaneous pull of the lever 1 in the direction of the continuous arrow in Figure 1 (for example by an unintended blow or an unsupervised child left in the car) the first spring 40 in the cavity between the upper part 13 and the lower part 14 of the actuating button 10 is compressed. Thereby, a force is exerted on the rod 30 (in the opposite direction of the dashed arrow in Figure However, since the detent pawl 20 is engaged, the force exerted by the spring 40 cannot release the detent pawl (see above) so that the parking 20 brake remains applied. Further, by the compression of the first spring 40 arranged between the actuating button 10 and the disk-like end 31 an excessive mechanical stress (for example S* caused by a blow on the actuating button 10) is dampened and kept away from the detent pawl.

i 25 When the pressure on the actuating button 10 decreases, it is by the compression of the first spring 40 and the simultaneously compressed second spring 50 pushed back into its starting position.

However, if the lever 1 is simultaneously pulled and thus the detent pawl 20 released, a compression of the first spring 40 caused by a pressure on the actuating button 10 and the resulting force on the rod 30 in the opposite direction of the dashed arrow in Figure 2 causes that the detent pawl 20 is clockwise rotated and thereby lifted from the blocking teeth 25 so that the lever 1 can be freely moved in both directions. If the pressure on the actuating button stops, the actuating button 10 is in this situation only by the compressed second spring moved back into its starting position. Simultaneously, the detent pawl 20 is once more biased in a counter clockwise direction.

By the selection of the spring constants of the first and second spring the resistance of the actuating button during operation can be adjusted, Although in the described embodiment of the lever unit compression springs 40, 50 are used, also an embodiment using expanding springs (or elastomeric elements subjected to expansion) are conceivable under a corresponding adaptation of the shape of the actuating button 10 and the rod For the lever unit according to the invention stable plastics, in particular Polyamide No. 6 and metals can be used. For the parts subject to a greater mechanical stress (detent pawl, blocking teeth etc.) preferably metals, for example steel, are used, whereas for the other parts for cost reasons preferably plastic is used. The compression springs are preferably made out of spring 15 steel.

*e oo go ooo** o*o** e o

Claims

1. Lever unit, in particular for a parking brake of a motor vehicle, with a lever and a security mechanism, wherein the security mechanism comprises: a. an operating element; b. a releasable ratchet mechanism which blocks a movement of the lever into a first direction and which is unloaded by a movement of the lever into a second direction; c. a transmitting element for transmitting the movements of the operating element onto the ratchet mechanism; d. a first spring element arranged between the operating element; and the transmitting element which is loaded or unloaded by the operation of the operating element, wherein e. the spring element provides in the loaded state a force onto the transmitting element which is not sufficient to release the ratchet 15 mechanism to move the lever into the first direction; and f. the operating element and the spring element are arranged in-side a bushing inside the lever.

2. Lever Unit according to claim 1, wherein the locking mechanism comprises a detent pawl and a plurality of blocking teeth. 20

3. Lever unit according to claim 2, wherein the transmitting element is provided as a rod for moving the detent pawl relative to the blocking teeth.

004. Lever unit according to claim 3, where a second spring element is provided to bring the actuator after its operation back into its starting position and to bias 0::0 .the detent pawl in the direction of the blocking teeth. gig

5. Lever unit according to claim 4, wherein the first and second spring element are provided as compression springs.

6. Lever unit according to one of the preceding claims wherein the security mechanism is arranged inside the lever unit.

7. Parking break with a lever unit according to one of the claims 1 to 6.

8. A lever unit, in particular for a parking brake of a motor vehicle, with a lever and a security mechanism, substantially as hereinbefore described with reference to the accompanying drawings. Dated 23 October, 2002 Fico Cables 3 ST Patent Attorneys for the Applicant/Nominated Person -0SPRUSON FERGUSON '0 Q\-7- [R\LIBD]03000.doc:caa