GB2313296A

GB2313296A - Anchoring arrangements for windscreen wiper arm springs

Info

Publication number: GB2313296A
Application number: GB9610937A
Authority: GB
Inventors: Mark Anthony Lewis; Alistair Duncan Robertson; Jeffrey Hugh Williams; Dennis Williams; Mahesan Pathmanathan
Original assignee: Trico Ltd; Trico Products Corp
Current assignee: Trico Ltd; Trico Products Corp
Priority date: 1996-05-24
Filing date: 1996-05-24
Publication date: 1997-11-26
Anticipated expiration: 2016-05-24
Also published as: GB9610937D0; GB2313296B

Abstract

An anchor tail 4 is provided, which will be attached to the end of the biassing spring of a pivotal wiper arm assembly. This tail terminates in an elongated head 5 to create a T-formation. The head 5 is passed through a slot 6 in a plate 7 forming part a drive head 1 and is rotated through 90{ so that the head 5 is securely located beneath the body of the plate 7. A slot 8 is formed in the other end of the tail 4 for location of a hook at the end of the biassing spring. Any wear created by rocking of the tail 4 and head 5, under pressure of the biassing spring, will be distributed over the length of the head 5. The potential for wear due to abrasion between the tail 4 and the plate 7 can be reduced by forming the end of the slot 6 with a rounded or angled upper face.

Description

Improvements relating to Anchoring Arranqement There is often a need to interconnect two bodies in such a way that they can articulate with respect to one another. Abrasion and wear at the interconnection point can lead to damage and ultimately disruption of the interconnection.

According to the present invention there is provided an anchoring arrangement for attaching one body to another wherein a first body incorporates an elongated slot passing through a plate and the second body carries a tail terminating in an enlarged head which forms a T with the tail, the head having a length comparable to but less than the length of the slot and a thickness less than the width of the slot, and the tail, at least where it joins the head, having a cross-section of a width in any direction less than the width of the slot, whereby the head can be passed through the slot and then rotated through 900 to lie under the body of the plate, with the tail passing through the slot.

Such a design provides a large area of contact between the head of the second body and the material of the plate, to either side of the slot, which can absorb wear, for a substantial period of time, created by a rocking movement of the tail of the second body with respect to the plate of the first body. The T-shaped end of the second body should be formed from a material that will resist permanent deformation under operating loads and will have a high wear and corrosion resistance.

It is preferred that the end of the slot against which the tail will bear when the two bodies are attached to one another should have a face which is rounded or angled towards the tail of the second body. This helps to reduce the possibility of wear on the portion of the tail which joins the head of the T.

The second body may be attached to or form part of a biassing spring. This is particularly relevant in an arrangement where the first body is a drive head of a windscreen wiper assembly. In this instance the drive head will ideally carry a pivotal mounting for a wiper arm of the assembly.

The invention may be performed in various ways and a preferred embodiment will now be described, by way of example, with reference to the accompanying drawings, in which:- Figure 1 is a perspective view of a drive head of a windscreen wiper assembly; Figure 2 is an underneath view of part of the drive head shown in Figure 1, together with an anchor tail of a biassing spring; Figure 3 shows the two parts of Figure 2 interconnected; Figures 4A and 4B illustrate alternative shapes for a slot forming part of the drive head, in cross-section on line IV-IV of Figure 2; Figure 5 is an underneath view of an alternative form of drive head of the invention; and Figure 6 is an illustration of a detail of the type of drive head shown in Figure 5 together with an anchor tail.

The drive head 1 of Figure 1 will be mounted onto a drive shaft of a motor by means of a shaped recess 2. At the other end aligned passageways 3 are formed for a pivot pin of a wiper arm of the wiper assembly. The wiper arm is additionally linked to the drive head 1 by a spring which allows the wiper arm to be pivoted to an outward position where it will be held by the spring.

As can be seen from Figures 2 and 3 an anchor tail 4 is provided, which will be attached to the end of the biassing spring. This tail terminates in an elongated head 5 to create a T-formation. The head 5 can be passed through a slot 6 in a plate 7 forming part of the drive head 1. After rotation through 900 the head 5 of the tail 4 will be securely located beneath the body of the plate 7. A slot 8 is formed in the other end of the tail 4 for location of a hook at the end of the biassing spring.

Any wear created by rocking of the tail 4 and head 5, under pressure of the biassing spring, will be distributed over the length of the head 5. The potential for wear due to abrasion between the tail 4 and the plate 7 can be reduced by forming the end of the slot 6 with a rounded face 9 (Figure 4A) or an angled face 10 (Figure 4B).

In the alternative arrangement shown in Figure 5 and 6 the slot 6A is in the form of a keyhole having an enlarged head 11. This enables the anchor tail 4 to be inserted with ease into the slot 6A but the width of the tail 4 will be a close dimensional working fit within the narrower portion 6B of the slot so that the tail 4 will be held in place with little or no potential for sideways movement. This reduces the possibility of wear due to movement between the tail 4 and the plate 7.

Claims

1. An anchoring arrangement for attaching one body to another wherein a first body incorporates an elongated slot passing through a plate and the second body carries a tail terminating in an enlarged head which forms a T with the tail, the head having a length comparable to but less than the length of the slot and a thickness less than the width of the slot, and the tail, at least where it joins the head, having a cross-section of a width in any direction less than the width of the slot, whereby the head can be passed through the slot and then rotated through 90" to lie under the body of the plate, with the tail passing through the slot.

2. An anchoring arrangement according to Claim 1, wherein the end of the slot against which the tail will bear when the two bodies are attached to one another has a face which is rounded or angled towards the tail of the second body.

3. An anchoring arrangement according to Claim 1 or Claim 2, wherein the second body is attached to or forms part of a biassing spring.

4. An anchoring arrangement according to Claim 3, wherein the first body is a drive head of a windscreen wiper assembly.

5. An anchoring arrangement according to Claim 4, wherein the drive head carries a pivotal mounting for a wiper arm of the assembly.

6. An anchoring arrangement substantially as herein described with reference to the accompanying drawings.