GB2041857A

GB2041857A - Vehicle Rear-view Mirror Mounting Arrangement

Info

Publication number: GB2041857A
Application number: GB7902990A
Authority: GB
Original assignee: Magnatex Ltd
Current assignee: Magnatex Ltd
Priority date: 1979-01-29
Filing date: 1979-01-29
Publication date: 1980-09-17
Also published as: GB2041857B

Abstract

A vehicle rear-view mirror mounting arrangement has a mirror support arm 3 mounted for turning movement about the substantially vertical axis of a bearing member 1 having a surface of revolution 11 formed with substantially vertical indexing grooves 13 extending parallel to the axis, an indexing ridge 19 of a retaining member 18 being urged towards the grooves by a leaf spring 20 to disengage from and engage with the respective groove to locate the arm in an indexed position relative to the bearing member. <IMAGE>

Description

SPECIFICATION Vehicle Rear-view Mirror Mounting Arrangement This invention relates to a vehicle rear-view mirror mounting arrangement, primarily for a commerical vehicle, comprising a mirror support arm mounted for turning movement about a substantially vertical axis with reference to a bearing member adapted to be secured to the side of a vehicle body.

In one such mounting arrangement, opposing faces of the mirror support arm and the bearing member are formed with interengaging rings of ratchet teeth extending perpendicularly to the axis and defining a plurality of indexing positions, the ratchet teeth being urged into engagement by a coil spring compressed by a bolt which extends parallel to the axis and about which the mirror support arm can ratchet forwards and backwards if the mirror should be struck or strike an object.

Such arrangements are of bulky construction in order to house the coil spring and may, in certain instances, transmit unacceptable vibrations caused by vehicle movement to the mirror support arm.

The main object of the present invention is to provide a vehicle rear-view mirror mounting arrangement which is compact and of neat appearance.

The present invention consists in a vehicle rear-view mirror mounting arrangement comprising a mirror support arm mounted for turning movement about a substantially vertical axis with reference to a bearing member adapted to be secured to the side of a vehicle body, characterized in that the bearing member has a surface of revolution about said axis, said surface being formed with a plurality of spaced apart indexing grooves extending substantially parallel to said axis and the arm carries a retaining member formed with a ridge extending parallel to said grooves and urged theretowards by a leaf spring located between the retaining member and an opposing part of the arm, said spring permitting the retaining member to disengage from and engage with the respective groove to locate the arm in an indexed position relative to the bearing member.

In a preferred embodiment of the invention, the bearing member comprises a part of generally cylindrical form which extends substantially parallel to said axis and which presents said surface of revolution, the cylindrical part projecting into a recess in the inner end of the mirror support arm such that portions of the arm are disposed at opposite ends respectively of said cylindrical part, the leaf spring and retaining member are disposed in an outer portion of said recess, a hinge pin which defines said axis extends through the arm portions and the bore in the cylindrical part, resilient means is interposed between one of the arm portions and the adjacent end of the cylindrical part and said indexing grooves have, at least at one end thereof an axial extent which is greater than that of the indexing ridge.

This construction reduces the vibration of the mirror support arm caused by vehicle movement.

The leaf spring may be of single or multiple leaf constrution.

The retaining member may be of a wear resistant plastics material or of metal and the mirror support arm and bearing member are conveniently metal diecastings.

In order that the invention may be more clearly understood, an embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a part-sectional rear elevation of a rear view mirror assembly for a commercial vehicle, including a mounting arrangement constructed in accordance with the invention, and Figure 2 is a cross-section taken along the line Il-Il of Figure 1.

The vehicle rear-view mirror assembly shown in the drawings comprises a bearing member in the form of a bracket 1 provided with countersunk holes 2 for receiving screws (not shown) for securing the mirror assembly to the side of a vehicle body. A mirror support 3 of open frame work construction is mounted at its inner end on the bracket 1 for turning movement about a headed hinge pin 4 which defines a substantially vertical axis and, at its outer end, the mirror support arm has a pst 5 carrying a rear-view mirror 6. The mirror drum 7 is connected to the post by a ball and socket joint 8 and is fixed to the post by a nut 9, the back of the mirror drum and joint being enclosed by a rubber or plastics cover 10.

The bracket 1 has a surface of revolution 11 presented by a generally cylindrical part 12 of the bracket and being formed with a plurality (four as illustrated) of spaced apart indexing grooves 13 extending substantially parallel to the axis of the hinge pin 4. The cylindrical part 12 projects into the wider inner portion of a stepped recess 14 in the inner end of the mirror support arm with the upper and lower walls of the recess forming arm portions 15, 16 disposed at opposite ends respectively of the part 12.The hinge pin 4 extends through and engages in the arm portion 15, the bore through the cylindrical part 12 and the arm portion 1 6 and is secured in position by a circlip 1 7 accommodated in a countersunk hole in the undersurface of the lower arm portion 1 6. The head of the pin 4 is accommodated in a countersunk hole in the upper arm portion 1 5 with a clearance between the bottom of the hole and the adjacent surface of the pin head.

The mirror support arm carries, in a narrower outer portion of the recess 14 in the inner end of the arm, a retaining member 18 formed with an indexing ridge 1 9 extending substantially parallel to the indexing grooves 13. The ridge 1 9 is urged towards the grooves 13 by a leaf spring 20 located between the retaining member and an opposing part of the arm formed by the base of the recess 14. Thus, the leaf spring is accommodated in the narrower outer portion of the recess 14, which is of lesser axial extent than the inner recess portion with the end of the spring engaging the retaining member 1 8 by means of a locating peg 21 which projects from the base of the recess and into a hole through the centre of the spring.As illustrated, the leaf spring 20 is of multiple-leaf construction and is of semi-elliptical form. The leaf spring causes the indexing ridge 1 9 to engage with a selected one of the indexing grooves to locate the mirror support arm 3 in an indexed position relative to the bracket 1 for correct rear viewing and to retain the arm in the indexed position during normal running of the vehicle. Also, the leaf spring permits disengagement of the indexing ridge with the respective indexing groove if the mirror support arm is turned to adjust the mirror to another indexed position and if the mirror strikes or is struck by an object in an accident or in an automatic car wash, the mirror support arm can turn backwards or forwards about the hinge pin and into a position in which the arm is disposed along the side of the vehicle body.

To guard against the possibility of the mirror support arm and/or the mirror striking the vehicle body when the mirror is struck or strikes an object, the amount of backwards and forwards turning movement of the arm is iimited by the inner ends of the side walls 22 of the recess 14 abutting against respective portions 26 and 27 forming two end stops, of the bracket 1. To facilitate engagement and disengagement of the indexing ridge when the mirror is turned, the ridge is outwardly tapered with the indexing grooves being complementary in shape and the form of the spring enables the retaining member to move outwardly with respect to the arm so that the indexing ridge enters the narrower portion of the recess 14 and can ride over the surface 11 of the cylindrical part 12.The recess side wals 22 and the inner face of the retaining member are curved to conform to the curvature of the surface 11.

There is a clearance between the upper end of the cylindrical part 12 and the undersurface of the upper arm portion 14 and resilient means in the form of a bellville washer 23 which encircles the hinge pin 4 projects into this clearance from an annular recess in the upper end of the part 12.

The bellville washer 23 engages a washer 24 in the bottom of the annular recess and is held in position by an annular shoulder 25 of the hinge pin 4. By means of the clearances between the head of the hinge pin 4 and the bottom of the countersunk hole in the upper arm portion 1 5 and between the undersurface of the arm portion 1 5 and the upper end of the cylindrical part 1 2 and since the indexing grooves 13 have a greater axial extent than the indexing ridge 19, the bellville washer can flex or compress during vibration caused by vehicle movement and minimize vibration of the mirror support arm and thus of the mirror.

Various modifications may be made without departing from the invention. For example, the leaf spring may be turned through 1 BOC about an axis which is parallel to the hinge pin, in which case the locating peg will project from the retaining member 18. The rear-view mirror may be of any desired shape and construction.

Claims

1. A vehicle rear-view mirror mounting arrangement comprising a mirror support arm mounted for turning movement about a substantially vertical axis with reference to a bearing member adapted to be secured to a side of the vehicle body, characterized in that the bearing member has a surface of revolution about said axis, said surface being formed with a plurality of spaced apart indexing grooves extending substantially parallel to said axis and the arm carries a retaining member formed with a ridge extending parallel to said grooves and urged theretowards by a leaf spring located between the retaining member and an opposing part of the arm, said spring permitting the retaining member to disengage from and engage with the respective groove to locate the arm in an indexed position relative to the bearing member.

2. A mounting arrangement as claimed in claim 1, characterized in that the bearing member comprises a part of generally cylindrical form which extends substantially parallel to said axis and which presents said surface of revolution, the cylindrical part projecting into a recess in the inner end of the mirror support arm such that portions of the arm are disposed at opposite ends of said cylindrical part.

3. A mounting arrangement as claimed in claim 2, characterized in that the leaf spring and retaining member are disposed in an outer portion of said recess, a hinge pin which defines said axis extends through the arm portions and the bore in the cylindrical part, resilient means is interposed between one of the arm portions and the adjacent end of the cylindrical part and in that said indexing grooves have, at least at one end thereof, an axial extent which is greater than that of the indexing ridge.

4. A mounting arrangement as claimed in any one of claims 1 to 3, characterized in that the -leaf spring is of multiple leaf construction.

5. A mounting arrangement as claimed in any one of claims 2 to 4, characterized in that the leaf spring is of semi-elliptical form and is located in said recess by a locating peg projecting from the retaining member or the base of said recess and into a hole through the centre of the spring.

6. A mounting arrangement as claimed in any one of claims 1 to 5, characterized in that the bearing member has end stops which are engageable by the mirror support arm to limit the amount of turning movement in two directions respectively about said axis.

7. A mounting arrangement as claimed in any one of claims 1 to 6, characterized in that the mirror support arm is of open frame-work construction.

8. A mounting arrangement as claimed in any one of claims 1 to 7, characterized in that the retaining member is of wear-resistant plastics material.

9. A vehicle rear-view mirror mounting arrangement substantially as hereinbefore described with reference to the accompanying drawings.

10. A vehicle rear-view mirror including a mounting arrangement as claimed in any one of the preceding claims.

11. A vehicle having secured to a side of its body a rear-view mirror as claimed in claim 10.