Improvements relating to wiper arm assemblies

Abstract: An armpiece 1 is placed in a desired location within a retainer 2 and side portions 6 are then swaged down at 7 over the armpiece 1. At the same time the material of the retainer 2 is crimped at 8 into recesses 4 which have been preformed in the side edges of the armpiece 1 to provide a secure location of the armpiece within the retainer 2.

Description: A wiper arm assembly forms a linkage between the drive motor and the wiper blade of a windscreen wiper and conventionally comprises two parts, namely a retainer and an armpiece. In the final construction of such a wiper arm assembly it is required that the end of the armpiece should be securely held within the retainer. The tip of the armpiece often provides a mounting for a compression spring which holds the wiper arm down onto the windscreen. Consequently there is a force (provided by the spring) tending to pull the armpiece further into the retainer. Secure fixing of the armpiece is therefore very important. A wiper arm assembly as illustrated in GB-A-2069325 comprises an armpiece and a retainer, the retainer having side portions which are swaged over one end of the armpiece, said one end of the armpiece having grip configurations in the form of cut away portions or projections, into or about which the parts of the swaged side portions have been crimped during the swaging procedure. According to the present invention the swaging comprises external deformation of these side portions so that the inner faces of the deformed sections of the side portions flow into or about said grip configurations to hold the armpiece firmly within the retainer. The moulding of the material of the side portions of the retainer into or about the grip configurations provides a secure interconnection of the armpiece with the retainer. In one form of construction the grip configurations can comprise one or more notches cut into both side edges of the end part of the armpiece, into which crimped parts of the retainer have been impressed. The grip configurations could comprise a single elongated notch on either side of the end portion of the armpiece. A preferred arrangement has at least two notches in each side edge of the retainer, which notches are staggered with respect to one another from the one side to the other. This provides a better gripping effect and reduces the extent to which the body of the armpiece is weakened. The invention may be performed in various ways and some preferred embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:- Figures 1A and B are perspective views of the end of an armpiece of an assembled wiper arm assembly for one form of the invention; and Figures 2A and B are corresponding views for a second embodiment of the invention. In the arrangement shown in Figure 1 the end of an armpiece 1 is fitted into the end of a retainer 2. The armpiece 1 has an upturned end 3 to provide a mounting for a retaining spring. The sides of the armpiece 1 are cut away to provide two elongated notches 4. The precise location of these notches is ensured by providing a pilot hole 5 for location of the arm 1 during the cutting of the notches. When the armpiece 1 has been placed in the desired location within the retainer 2 the side portions 6 are swaged down at 7 over the armpiece 1 and at the same time crimping of the material of the retainer 2 at 8 into the recesses 4 provides a secure location of the armpiece within the retainer 2. In the wiper arm assembly shown in Figure 2 a pair of notches 9 are formed in each side of the armpiece 1. Again the side portions 7 of the retainer are swaged over and crimped inwardly to locate part of the material of the retainer at 8 in the notches 9. The staggered location of the notches 9 reduces the extent of weakening of the armpiece 1.

Claims: A wiper arm assembly comprising an armpiece (1) and a retainer (2), the retainer having side portions (7) which are swaged over one end of the armpiece, said one end of the armpiece having grip configurations in the form of cut away portions (4,9) or projections, into or about which the parts of the swaged side portions have been crimped during the swaging procedure characterised in that the swaging comprises external deformation of these side portions so that the inner faces of the deformed section of the side portions flow into or about said grip configurations to hold the armpiece firmly within the retainer. A wiper arm assembly according to Claim 1, wherein the grip configurations comprise one or more notches (4,9) cut into both side edges of the end part of the armpiece, into which crimped parts of the retainer have been impressed. A wiper arm assembly according to Claim 2, wherein there are at least two notches (9) in each side edge of the retainer, which notches are staggered with respect to one another from the one side to the other.

Inventors: CLARKE BYRON, DANCER NIGEL PAUL, ROBERTSON ALISTAIR DUNCAN, CLARKE, BYRON, DANCER, NIGEL PAUL, ROBERTSON, ALISTAIR DUNCAN
Applicants: TRICO PRODUCTS CORP, TRICO PRODUCTS CORPORATION
Application year: 1997
Main classification: B60S1
IPC codes: B60S1