GB2156052A

GB2156052A - Manual actuator, e.g. brake or clutch lever

Info

Publication number: GB2156052A
Application number: GB08407245A
Authority: GB
Inventors: Christopher John Boyett
Original assignee: Sturmey Archer Ltd
Current assignee: Sturmey Archer Ltd
Priority date: 1984-03-20
Filing date: 1984-03-20
Publication date: 1985-10-02
Also published as: GB8407245D0; GB2156052B

Abstract

An actuator (10) for a push-pull cable, eg a brake for a cycle, has a support for securement to structure and a generally L-shaped lever (21) having a longer limb (22) and a shorter limb (23), the end of the shorter limb and the support having complementary load bearing surfaces (24, 17) circular about a common axis enabling the lever (21) or the lever (21) and the support to be made from plastics material. The load bearing surfaces (24, 17) can be part spherical or can have a plurality of part cylindrical surfaces of different diameters. Instead of the lever (21) having the boss (24) and the support a socket, the support can have the boss and the lever can have the socket. <IMAGE>

Description

SPECIFICATION Actuator This invention relates to an actuator for one end of a push pull cable whose other end may connect with a brake, clutch or similar equipment on, for example, a cycle.

Conventional brake actuators for cycles are normally made from metal and have a generally L-shaped lever having a longer and a shorter limb, the shorter limb being pivoted adjacent its free end on a pin in a support secured to a handlebar and the longer limb extending generally alongside the handlebar, one end of the core of a push-pull cable being secured to the short limb remote from its free end.

It is clearly desirable to make such an actuator from plastics material to obtain advantages in weight reduction, ease of manufacture, greater resistance to corrosion and lack of maintanence such as lubrication. However, the adoption of plastics material poses a problem at the pivot. The aforesaid known metal actuator has a pin and this is quite sufficient to bear the high loads exerted in use. With the lever, (plus possibly also the body) of plastics material such a pin connection is inadequate. A metal pin in plastics seating would wear or deform the plastics to such an extent under load that the assembly would soon fail. Conversely, a plastics pin would have to be so large that the compactness and appearance of the actuator would be compromised, and large amounts of material would be needed.

An object of the present invention is to provide an actuator structure wherein the above disadvantage can be obviated or minimised.

Accordingly the invention provides an actuator for a push-pull cable comprising a support for securement to structure and a generally L-shaped lever having a longer limb and a shorter limb, the free end of the shorter limb and the support engaging each other by complementary load-bearing surfaces which are circular about a common axis.

Preferably the surfaces are part-spherical or part-cylindrical. The housing advantageously provides a socket and the end portion of the shorter limb is in the form of a boss received therein. Alternatively the housing can present the boss and the limb end can have the socket therein.

The support can have a socket for receiving an end portion of the sheath of the push-pull cable and a passage extending therefrom for accommdating the core of the cable.

The lever can have a nose extending beyond the end of the longer limb past the shorter limb and accommodating an end portion of the cable core which terminates in a nipple secured to the lever by being disposed in a recess therein. The nose can have a slot or passage therein whose radially inward base surface is circular about the axis of pivoting to ensure that axial tension is always applied to the cable core in use.

The invention will be described further, by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a plan view of a preferred actuator of the invention in position on a cycle handlebar.

Figure 2 is a longitudinal cross-sectional view of the actuator of Fig. 1; and Figure 3 is a cross section on the line 3-3 of Fig. 2.

A preferred actuator 10 of the invention has a support 11 moulded from plastics and is in use secured to a cycle handlebar 1 2 or similar structure by a steel band 1 3 secured by a screw 14 and nut 1 5. The handlebar facing surface 1 6 of support 11 is part-cylindrical.

The support 11 is generally channel-shaped and adjacent its left hand end in the drawings has a socket providing a part-cylindrical seating surface 1 7. At its right hand end the support 11 has a snout 1 8 which is forward with a cylindrical socket for receiving a sheath 1 9 of a push-pull cable 20.

The actuator 10 also has an L-shaped lever 21 having a longer limb 22 constituting a handle and a shorter limb 23 which terminates in a part-cylindrical boss 24 complementary to the surface 1 7. Boss 24 engages the socket in the support 11 and a pin 25 secures the lever 21 and support 11 together, and serves to prevent separation of the lever 21 and support 11. Although the pin 25 may take some of the load upon operation of the actuator, the main load is borne by the engaged cylindrical surfaces.

The lever 21 has a transverse bore 26 which receives a nipple 27 on the end of the core 28 of the cable 20. The core 28 is accommodated in a slot 29 in the lever 21 and an extended nose 30 thereof. The end 31 of the nose 30 forms a stop and engages a stop surface 32 in the support 11. The slot 29 has a lower surface 33 which is circular about the pivot axis to ensure that only axial tension is applied to the core 28.

In use, the maximum load applied to the lever 21 due to tensioning of the core 28 is a radially inward force which is borne by engaged surfaces 1 7 and 24, thus relieving pin 25 which, in a plastics construction, would without such surfaces, merely deform the components.

The invention is not limited to the foregoing and variations can be made thereto within the scope of the following claims.

For example, the complementary load bearing surfaces 24, 1 7 can be of any convenient cross-section circular about the pivot axis, eg can be part spherical or can have a plurality of part cylindrical surfaces of different diameters.

Instead of the lever 21 having the boss 24 and the support providing a socket, the support can have the boss and the lever can have the socket.

Many other variations are possible.

Claims

1. An actuator for a push-pull cable comprising a support for securement to structure and a generally L-shaped lever having a longer limb and a shorter limb, the free end of the shorter limb and the support engaging each other by complementary load-bearing surfaces which are circular about a common axis.

2. An actuator as claimed in claim 1, wherein the surfaces are part-spherical or partcylindrical.

3. An actuator as claimed in claim 1 or 2 wherein the housing provides a socket and the end portion of the shorter limb is in the form of a boss received therein.

4. An actuator as claimed in claim 1 or 2 wherein the housing presents a boss and the limb end has a socket therein.

5. An actuator as claimed in claim 3 wherein the support has a socket for receiving an end portion of the sheath of the push-pull cable and a passage extending therefrom for accommodating the core of the cable.

6. An actuator as claimed in claim 3 or 5 wherein the lever has a nose extending beyond the end of the longer limb past the shorter-limb and accommodating an end portion of the cable core which terminates in a nipple secured to the lever by being disposed in a recess therein.

7. An actuator as claimed in claim 6 wherein the nose has a slot or passage therein whose radially inward base surface is circular about the axis of pivoting to ensure that axial tension is always applied to the cable core in use.

8. An actuator for a push-pull cable substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

CLAIMS Amendments to the claims have been filed, and have the following effect: Claim 1 above has been deleted or textually amended.

New or textually amended claims have been filed as follows:

1. An actuator for a push-pull cable comprising a support for securement to structure and a generally L-shaped lever having a longer limb, constituting a handle, and a shorter limb, the free end of the shorter limb and the support engaging each other by complementary surfaces which are circular about a common axis, said surfaces being so disposed that when pivotal movement of said handle in a direction tending to increase tension in a core of said cable applies a force to said shorter limb tending to move it axially in a direction towards its free end, such tendency is resisted by and said force is transmitted from said shorter limb to said support by said complementary surfaces.