GB2046408A

GB2046408A - Apparatus for supporting and sealing a manually operated shift lever

Info

Publication number: GB2046408A
Application number: GB8007856A
Authority: GB
Original assignee: International Harverster Corp
Current assignee: Navistar Inc
Priority date: 1979-04-05
Filing date: 1980-03-07
Publication date: 1980-11-12
Also published as: FR2453047A1; DE2913774A1; DE2913774C2

Abstract

In apparatus for supporting and sealing a manually operated shift lever (8) a support (1) is provided on which the lever is mounted for appropriate movement. An annular flexible sealing member (6) has an inner surface in contact with the shift lever and rests on part (5) of the support to be movable relative thereto. The sealing member is secured neither to the part (5) of the support nor to the shift lever (5) but effects a seal between these elements. <IMAGE>

Description

SPECIFICATION Apparatus for supporting and sealing a manually operated shift lever This invention relates to apparatus for supporting and sealing a manually operated shift lever. It may find particular application in the supporting and sealing of gear shift levers on motor vehicles, but the broad concept is more generally applicable.

One known form of supporting sealing means for a manually operated shift lever comprises a flexible sealing member which is secured both to the shaft of the shift lever and to a support on which the lever is mounted. Although the design provides a soundmuffling and dirt-deflecting seal the costs are high because of the moulding, gluing, vulcanisation or other costs involves in securing the sealing member to the respective components. Furthermore, in use high stresses develop in the sealing member leading to early wear of this component, which generally necessitates replacement not only of the seal, but also of the complete shift lever, cleaning of the old seal from the shift lever being more expensive than such replacement. In addition, use of a seal of this known type restricts travel of the shift lever to small distances.

The present invention has for its objective to overcome the disadvantages of such earlier construction, without sacrificing sound-muffling and dirt-deflecting capabilities.

According to the present invention apparatus for supporting and sealing a manually operated shift lever comprises a support on which the lever is mounted for appropriate movement, and an annular flexible sealing member having an inner surface in contact with a shaft of the shift lever and resting on part of the support to be movable relative thereto, the member effecting a seal between the shaft and the part of the support.

In this arrangement the annular, flexible sealing member is a simple, easily manufactured and cheap component. The mounting of the sealing member is also extremely simple and it allows comparatively long paths of movement for the shift lever, not only laterally of the sealing member but also vertically with respect to the sealing member. During such movements satisfactory sealing is maintained and the sealing member continuously rests on the part of the support and follows exactly the shifting movements of the shift lever.

Preferably the part of the support on which the sealing member rests comprises a guide face having a circular opening through which the shaft of the shift lever passes, and the sealing member has a circumferential groove in its outer surface, that part of the guide face surrounding the circular opening fitting within the groove and the inner diameter of the groove being less than the diameter of the circular opening by an amount that allows the sealing member to move freely relative to the guide face during all normal movements of the shift lever.

It is particularly advantageous if the inner surface of the sealing member has a convex cross-section, in order to reduce compressive stresses on the sealing member during movement of the shift lever, particularly to its extreme positions. The sealing member is desirably made from a flexible plastics material, for example polyvinyl chloride, polyurethane foam or similar material.

A housing, for example a cover of a transmission housing can serve as that part of the support on which the lever is mounted. However, any other component, for example a floor plate of the operator's platform can alternatively be used for the same purpose. In the latter case that part of the support on which the sealing member rests is conveniently a component of inverted bowl-shaped cross-section secured to the floor plate, the guide face for the sealing member being formed by a level centre section of the component. Use of a component of inverted bowl-shaped cross-section is advantageous, since the higher centre section of this component assists in preventing coarse dirt particles from penetrating between the sealing member and the guide face of the component. The component may be manufactured of metal, a polymeric plastics material or some other material.

A particular embodiment of apparatus according to the invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, the single figure of which is a cut away perspective view of the apparatus, partly sectioned.

Referring now to the drawing this shows the floor plate 1 of an operator's platform of a motor vehicle.

An inverted bowl-shaped component 2, preferably made of polymeric plastics material, is mounted on the floor plate 1 by any convenient means. The component comprises a laterally extending flangetype edge 3, an outer annular section 4 and a level centre section 5 which extends parallel to the floor plate 1 and constitutes a guide face. An annular, flexible sealing member 6, desirably made of plastics material such as polyvinyl chloride or a polyurethane foam, rest on the guide face 5 and is freely movable relative thereto within the plane of that face. The sealing member 6 surrounds a shaft 8 of a manually operated shift lever 7.

The shift lever 7, which controls a gear shift mechanism (for example a synchronised creep gear shifting mechanism), has a conventional ball and socket joint 9 comprising a top guide plate 11, a bottom guide plate 12 and a seal 13 arranged between the two plates. Beneath the joint 9 of the shaft 7 is connected to a guide sleeve 14 located above a guide piece 15, which is connected by a yoke 16to a rod 17 of the creep gear. The guide plates 11 and 12 are mounted to the floor plate 1 by means of bolts 18.

With the exception of a circular space immediately surrounding the joint 9 and guide plates 11 and 12, sound-muffling foam material 21 is filled into the space between the floor plate 1 and the support 2.

The sealing member 6 has a circumferential groove 22 in its outer surface, dividing the radially outer part of this member into upper and lower lips 23 and 24. The lips fit to opposite sides of the guide face 5 to mount the sealing member on this face in such a way that the sealing member is able to move horizontally relative to the face. The inner diameter 25 of the guide face 5 is considerably larger than the inner diameter 26 of the circumferential groove 22.

This allows the shift lever 7 to be moved to its extreme positions, indicated by the chain lines 27, 28 without causing the inner diameter 26 of the sealing member 6 to contact the inner diameter 25 of the guide face 5. The disposition of the members is such that with the lever 8 in its central, neutral position the lever 8, sealing member 6 and circular opening 25 in the guide face 5 are all concentric.

The inner surface 29 of the sealing member 6 (which forms the passage for the shift lever) has a convex cross-section and rests against the shift lever without being secured thereto. This allows the shift lever to rest against the inner surface without substantially distorting that surface even when the lever is moved to its extreme positions.

Itwill be appreciated that the apparatus described effects proper sealing around the shift lever during all lateral movements of that lever. Furthermore, the sealing effect is maintained for any limited vertical movement of the shift lever that may be made.

Claims

1. Apparatus for supporting and sealing a manually operated shift lever, comprising a support on which the lever is mounted for appropriate movement, and an annular flexible sealing member having an inner surface in contact with a shaft of the shift lever and resting on part of the support to be movable relative thereto, the member effecting a seal between the shaft and the part of the support.

2. Apparatus according to claim 1, in which the part of the support on which the sealing member rests comprises a guide face having a circular opening through which the shaft of the shift lever passes, and the sealing member has a circumferential groove in its outer surface, that part of the guide face surrounding the circular opening fitting within the groove and the inner diameter of the groove being less than the diameter of the circular opening by an amountthat allows the sealing memberto move freely relative to the guide face during all normal movements of the shift lever.

3. Apparatus according to claim 2 in which the support comprises a housing or floor plate on which the lever is mounted, and a component of bowlshaped cross-section secured to the housing or floor plate, the guide face being formed by a level centre section of said component.

4. Apparatus according to claim 3 in which the component is manufactured of a polymeric plastics material.

5. Apparatus according to claim 3 or claim 4, in which, with the exception of the area wherein the lever is mounted on the housing or floor plate, the space between that plate and the component is filled with a sound-muffling material.

6. Apparatus according to any one of the preceding claims in which the lever is mounted on the support by a ball-and-socket joint.

7. Apparatus according to any one of the preceding claims in which the inner surface of the sealing member has a convex cross-section.

8. Apparatus according to any one of the preceding claims in which the sealing member is manufactured of a flexible plastics material.

9. Apparatus for supporting and sealing a manually operated shift lever, substantially as herein described with reference to the accompanying drawing.