GB2321845A

GB2321845A - Windscreen wiper arm of adjustable length

Info

Publication number: GB2321845A
Application number: GB9802255A
Authority: GB
Inventors: Alistair Duncan Robertson; Edward John Bosley; Dean Cubitt
Original assignee: Trico Products Corp
Current assignee: Trico Products Corp
Priority date: 1997-02-05
Filing date: 1998-02-04
Publication date: 1998-08-12
Also published as: GB9702286D0; GB9802255D0

Abstract

When a bolt 10 is loosened, a block 7 can slide within a sleeve 11 (by virtue of an adjustment slot 9 in the block 7 through which the bolt 10 passes) until a desired length for a wiper arm comprising a box section 5 and a retainer part 6, is achieved. The bolt is then secured to lock the block 7 within the sleeve 11. The sleeve 11 is riveted within the retainer 6 by rivets at positions 12.

Description

Improvements relating to Windscreen Wiper Arm Adiustment For certain types of windscreen wiper arm it is desirable to be able to alter the arm length to some extent, to suit a particular use. This is especially the case with a commercial windscreen wiper assembly which has a main arm and a linked slave arm. It is often necessary to be able to adjust the length of the slave arm to suit the particular configuration of the windscreen with which is it used, for example.

According to the present invention there is provided a windscreen wiper arm with an adjustment mechanism in the form of an adjustor body connecting a first main part of the arm which is formed of box section to a second retainer part of the arm, the adjustor body comprising a block located at least partially within the box section of the first part of the arm and at least partially within a sleeve member secured to or forming part of the second part of the arm, with the block being slidably movable with respect to either the first or the second part of the arm, and retaining mechanism for fixing said block at a chosen location against such slidable movement.

For heavy duty commercial designs the wiper arm needs to be fairly robust and a box section is particularly suitable for this purpose. This does however create difficulties in incorporating a mechanism which enables the length of the arm to be adjusted. The mechanism of the present invention overcomes this problem by utilising the particular design of adjustor body in connection with the box section of the arm.

In one preferred arrangement the retaining mechanism comprises a fixing bolt passing through said sleeve and received within a slotted passageway extending within said block, in the longitudinal direction of the arm, whereby the bolt can be tightened to fix the block against sliding movement within the sleeve, when the block has been moved relative to the sleeve to said chosen location.

In an alternative preferred arrangement the block is slidable within the first part of the arm and is held with respect to the second part of the arm by one or more fixing bolts passing through a respective slotted passageway formed in the box section of the first part of the arm, and extending in the longitudinal direction of the arm, each bolt also passing through the second part of the arm, whereby each bolt can be tightened to fix the block against sliding movement within the first part of the arm when the first part of the arm has been moved relative to the block to said chosen location.

The invention may be performed in various ways and preferred embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which:- Figure 1 is a view of a commercial dual wiper arm assembly; Figure 2 shows a detail of the slave arm of the assembly shown in Figure 1; Figure 3 illustrates part of the arm of Figure 2 in an extended condition; Figure 4 is a view of an adjustment block of the assembly of Figure 3; Figure 5 is an underneath view of the arm as shown in Figure 3; Figures 6 and 7 are top and underneath views respectively of a detail of the interconnection of the wiper arm and retainer of Figures 1 to 5; Figure 8 is an exploded view of an alternative form of adjustment mechanism for a wiper arm assembly; and Figure 9 illustrates the full wiper arm assembly of Figure 6 with the parts connected together.

The commercial windscreen wiper arm illustrated in Figure 1 has a main arm 1 and a slave arm 2, linked at one end 3 to a drive mechanism and at the other end to a wiper blade mounting 4. As can be seen from Figure 2 the slave arm 2 is formed from a box section 5 together with a retainer part 6 of the arm. The box section 5 has a block 7 (see Figures 3 and 4) inserted therein and secured by a rivet 8. The other end of the block 7 incorporates an adjustment slot 9. A bolt 10 passing through the retainer 6 and a sleeve 11, which receives the other end of the block 7, also passes through the adjustment slot 9. When the bolt 10 is loosened the block 7 can slide within the sleeve 11 until a desired length for the slave arm 2 is achieved. The bolt 10 is then secured to lock the block 7 within the sleeve 11. The sleeve 11 is riveted within the retainer 6 by rivets at positions 12 (see Figure 6). The outer end of the sleeve 11 is shaped and provided with a hole 13 (Figure 7) to receive the end of a spring 14 which acts in the usual way to hold the wiper arm in either a raised or a (lowered) operating position.

In the arrangement shown in Figures 8 and 9 a connecting block member 15 is received within the box section 5 and the box section in turn is received within a sleeve portion 16 formed at one end of the retainer part 6 of the wiper arm. Slots 17 are formed in the box section 5 and a pair of bolts 18 are located through the retainer part 6, the slots 17 and passageways 19 through the block 15 and are held in place by nuts (not shown). With the nuts loosened the box section 5 can be slid relative to the retainer part 6, about the block 15 to a desired location. The nuts can then be tightened about the bolt 18 so as to secure the box section 5 relative to the retainer part 6 in the chosen location.

In this particular example, at least, the block 15 could be formed as a box section rather than as a solid block. If desired a spring anchorage can be provided on a fixed part of the adjuster formation, namely the block 15 It will be appreciated that this adjustment mechanism could equally well be used on a windscreen wiper which has a single arm but where a degree of adjustment would be useful.

Claims

1. A windscreen wiper arm with an adjustment mechanism in the form of an adjustor body connecting a first main part of the arm which is formed of box section to a second retainer part of the arm, the adjustor body comprising a block located at least partially within the box section of the first part of the arm and at least partially within a sleeve member secured to or forming part of the second part of the arm, with the block being slidably movable with respect to either the first or the second part of the arm, and retaining mechanism for fixing said block at a chosen location against such slidable movement.

2. A wiper arm according to Claim 1, wherein the retaining mechanism comprises a fixing bolt passing through said sleeve and received within a slotted passageway extending within said block, in the longitudinal direction of the arm, whereby the bolt can be tightened to fix the block against sliding movement within the sleeve, when the block has been moved relative to the sleeve to said chosen location.

3. A wiper arm according to Claim 1, wherein the block is slidable within the first part of the arm and is held with respect to the second part of the arm by one or more fixing bolts passing through a respective slotted passageway formed in the box section of the first part of the arm and extending in the longitudinal direction of the arm, each bolt also passing through the second part of the arm, whereby each bolt can be tightened to fix the block against sliding movement within the first part of the arm when the first part of the arm has been moved relative to the block to said chosen location.

4. A wiper arm according to any one of Claims 1 to 3, wherein a spring anchorage is provided on a fixed part of the adjustor formation.

5. A windscreen wiper arm with an adjustment mechanism substantially as herein described with reference to the accompanying drawings.