Patent GB-712610-A (GB)
Title: Improvements in or relating to windscreen wiper blades
IPC: B60S1/38
Filed: 1950-09-18
Abstract: 712,610. Windscreen cleaners. O'SHEI, W. E. Sept. 18, 1951 [Sept. 18, 1950; Sept. 25, 1950; Oct. 17, 1950; Dec. 4, 1950], Nos. 22915/50, 23495/50, 25272/50, and 29679/50. Class 138 (1) In a windscreen wiper blade, particularly for curved windscreens, the back edge of the squeegee is embraced substantially throughout its length by a plurality of rigid channelshaped backing members arranged along the length of the squeegee and connected together for relative rocking movement in the plane of the squeegee, the side portions of the backing members supporting the squeegee against transverse deflection out of its plane whilst leaving the squeegee free to be resiliently deflected in its own plane within and relative to the individual backing members in order to accommodate itself to the curvature of the windscreen. In the embodiment shown in Figs. 2 and 3, four backing members 6 are arranged end to end along the back of the squeegee 1. The outer ends of the two end members 6 are turned down as at 5 to retain the squeegee against longitudinal displacement. The free edges of the side walls 7, Fig. 3, of the members 6 are straight and provided with inturned flanges 8 to embrace flanges 2, 3 projecting from the back edge of the squeegee. The pairs of members 6 are hingedly connected at 18<SP>1</SP>, 19<SP>1</SP> to the ends of channelledyokes 21 which in turn and hingedly connected at 18, 19 to the ends of a channelled bridgepiece 10 adapted for connection to a wiper arm 13<SP>1</SP>. All the hinged connections allow the parts to rock with respect to each other about axes transverse to the plane of the squeegee. The connections between the bridge-piece and yokes and between the yokes and backing members are such that corresponding parts can only be connected or disconnected when those parts are at right angles to one another. When the parts are assembled the connections are thus prevented from separating. In operation the side walls 7 prevent transverse flexing of the squeegee but the arched back walls 9 of the channels 6 allow the sections of the squeegee between the ends of the channels to flex in the plane of the squeegee to assume a concave shape to suit the convex curvature of the windscreen. In the embodiment of Fig. 5, two channelled backing members 6 only are employed and the portion of the squeegee between the inner ends of those members is embraced by a channelled member 14 having side walls 15 with inturned flanges 16. When the distance between the members 6 is small the back of the member 14 need not be arched and is flat as shown. Fingers 17 extend from both ends of the member 14 into the members 6 and above the back of the squeegee. These fingers positively assist the squeegee to assume a straight position as the blade moves on to a flat portion of the windscreen from a curved portion but cause no restriction when the blade moves from a flat to curved portion of the windscreen. In the embodiment of Fig. 7, employing two members 6, a flat spring-metal strip 4 is disposed between the back of the squeegee and the members 6, and the member 14 and the fingers 17 are shortened. The strip 4 normally retains the wiping edge of the squeegee substantially straight but causes no restriction when the squeegee flexes to a concave form. Ends 18 of the bridge-piece 10 pass through apertures 19 in the backs 9 of the members 6 and are bent inwardly and are adapted to prevent the squeegee assuming a convex form but to allow of it assuming a concave form. The embodiment of Fig. 10, shows the member 14 integral with the members 6, notches 20 in the side walls of the single member permitting the sections to flex. The flanges 8 of the backing members 6 need not extend the entire length of the edges of the side walls 7 but can be replaced by flange sections or fingers located only at the ends of a backing member or at spaced points therebetween. If desired one or both of the backing members 6 in the case of the embodiment of Fig. 5, may have an arm extending from its inner end into the member 14 if this is of sufficient length to be arched. According to a modification light leaf or other springs may be positioned within the backing members to engage the back of the squeegee intermediate the ends of that of a member. In one form of this modification the spring means is constituted by a thin rubber-like web moulded integrally with the squeegee and upstanding from the back thereof. The first Provisional Specification discloses that the squeegee may be initially stretched in a longitudinal direction and retained thus by clamping the outer ends of the backing members thereto, whereby the squeegee assumes a normally curved form. The third Provisional Specification discloses and illustrates a squeegee having two channelled-backing members and a spring metal strip along the back of the squeegee without the interposing of a channelled member between the inner ends of the backing members. In this case the outer ends of the backing members are open and the ends of the spring strip are turned down to prevent displacement between the strip and squeegee. End clips on the outer ends of the backing members prevent displacement longitudinally, of the squeegee. The fourth Provisional Specification discloses and illustrates embodiments similar to the embodiments shown in Figs. 7 and 10 but in which the outer ends of the backing members are open and the ends of the spring metal strip are turned down to retain the squeegee. Specifications, 666,474, 679,540, 683,201 and 712,603 are referred to. Specifications 619,320, 626,016, 666,473, 675,757 and 712,611 also are referred to.