GB2301657A

GB2301657A - Handbrake lever

Info

Publication number: GB2301657A
Application number: GB9511194A
Authority: GB
Inventors: Alan James Banks
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1995-06-02
Filing date: 1995-06-02
Publication date: 1996-12-11
Anticipated expiration: 2015-06-02
Also published as: GB2301657B; GB9511194D0

Abstract

A pivoted handbrake lever employs a pawl 28 and ratchet arrangement 26 to hold the lever in any desired position. The pawl 28 is mounted on the lever through a flexible, resilient mounting 30 which deforms to allow the pawl to ride over the ratchet teeth, whilst providing a restoring force biasing the pawl into engagement with the ratchet teeth.

Description

HANDBRAKE LEVER This invention relates to a handbrake lever, in particular for use on wheeled vehicles.

Handbrake levers are conventionally pivoted to a fixed part of the vehicle and have a ratchet and pawl arrangement which ensures that the lever is retained in any position to which it is adjusted. The use of conventional ratchet and pawl arrangements however leads to undesirable noise and vibration during operation.

According to a first aspect of the invention, there is provided a pivoted handbrake lever comprising a pawl and ratchet arrangement to hold the lever in any desired position, wherein the pawl is mounted on the lever through an elastomeric mounting which deforms elastically to allow the pawl to ride over the ratchet teeth and to provide a restoring force biasing the pawl into engagement with the ratchet teeth.

According to a second aspect of the invention, there is provided a handbrake lever comprising a base member, a lever arm pivoted to the base member, a toothed rack forming a ratchet on the base member, and a pawl mounted on the lever arm for pivoting movement, the pawl being supported on a resilient mount which deforms to allow the axis about which the pawl pivots to move towards and away from the base member when the pawl rides over the ratchet teeth and which provides a restoring force biasing the pawl into engagement with the ratchet teeth, and means for deforming the resilient mount to lift the pawl away from the teeth.

The resilient mount may be a void elastomeric bush with a centre annulus and a peripheral annulus spaced apart and joined to one another by flexible webs. One of the annuli is then fixed to the lever arm and the other annulus is fixed to the pawl in a position such that, when external forces are removed, the pawl is in contact with the ratchet.

The means for deforming the resilient mount to lift the pawl can be a push rod ending in a push button at the end of the lever arm remote from the base member.

Use of an elastomeric mount to support the pawl makes it possible to omit a separate spring for providing a restoring force on the pawl, and also provides a "soft" characteristic when the pawl rides over the ratchet, to absorb noise.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view, partly in section, of a handbrake lever in accordance with the invention; Figure 2 is a side view of a void bush for use in the lever of Figure 1; and Figure 3 is a section through the bush of Figure 2 on the line III-III.

The lever of Figure 1 has a base member 10 which will be permanently secured to the vehicle bodywork by bolting and/or welding, as appropriate. A lever arm 12 is connected to the base member 10 through a pivot axle 14, and the lower end of the arm 12 has an attachment point 16 for a handbrake cable, in a known manner. The maximum possible angle of pivoting movement of the lever arm 12 on the base member 10 is limited by an arcuate slot 18 on the base member 10 into which a pin 20 fixed on the arm 12 will engage.

The lever arm has a hand grip 22 and a push button 24, at the end remote from the base member 10.

One edge of the base member 10 has a toothed surface at 26, and a pawl 28 is mounted on the arm 12. The pawl is secured to the arm 12 by a void bush, details of which are shown in Figures 2 and 3. The bush 30 has a central annulus 32 and a peripheral annulus 34 joined by resilient, elastic webs 36. In this embodiment, the central annulus 32 is secured to the lever arm 12 and the peripheral annulus 34 is secured to the pawl 28, but the opposite arrangement is also possible. It will be clear that the pawl axis can move relative to the lever arm by distortion of the webs 36, and that the webs 36 will provide a restoring force to return the pawl axis to its original position.

In use, to apply the handbrake, the lever 12 is lifted in the direction indicated by an arrow 38. The lever turns about the pivot axis 14, and a tip 40 of the pawl 28 rides against the surface 26 of the base member 10. The tip 40 rides up the flank of one tooth, over the top of the tooth and then down the opposite flank of the tooth before riding in the same way over the next tooth. When lifting of the lever 12 in the direction of the arrow 38 stops, the tip 40 will engage in a trough between two teeth on the surface 26 to retain the lever in the desired position. This is usually the "brake on" position.

The shape of the tip 40 and the shape of the teeth on the surface 26 will ensure that any pressure on the lever in the direction opposite to that of arrow 38 will merely serve to reinforce the engagement between the pawl tip 40 and the surface 26.

To release the handbrake, the push-button 24 will be pushed in and this will cause a push rod 42 to move to the right and to tip the pawl 28 (through distortion of the webs 36) until the pawl tip 40 is lifted away from the toothed surface 26. The lever 12 can then be lowered, i.e. moved in the direction opposite to that of arrow 38.

When the handbrake lever is lifted without first depressing the lever 24, the vibrations of the tip 40 as this travels over the teeth on the surface 26 will be damped and absorbed by the flexible webs 36 of the bush 30, and the pawl axis will move. As a result, the noise resulting from the operation of the handbrake will be low.

Claims

1. A pivoted handbrake lever comprising a pawl and ratchet arrangement to hold the lever in any desired position, wherein the pawl is mounted on the lever through an elastomeric mounting which deforms elastically to allow the pawl to ride over the ratchet teeth and to provide a restoring force biasing the pawl into engagement with the ratchet teeth.

2. A handbrake lever comprising a base member, a lever arm pivoted to the base member, a toothed rack forming a ratchet on the base member, and a pawl mounted on the lever arm for pivoting movement, the pawl being supported on a resilient mount which deforms to allow the axis about which the pawl pivots to move towards and away from the base member when the pawl rides over the ratchet teeth and which provides a restoring force biasing the pawl into engagement with the ratchet teeth, and means for deforming the resilient mount to lift the pawl away from the teeth.

3. A handbrake lever as claimed in Claim 2, wherein the resilient mount is a void bush with a centre annulus and a peripheral annulus spaced apart and joined to one another by flexible webs.

4. A handbrake lever as claimed in Claim 2 or Claim 3, wherein the means for deforming the resilient mount to lift the pawl is a push rod ending in a push button at the end of the lever arm remove from the base member.

5. A handbrake lever substantially as herein described with reference to the accompanying drawings.