Patent GB-843937-A (GB)
Title: Improvements in windscreen cleaners
IPC: B60S1/20
Filed: 1956-07-20
Abstract: 843,937. Windscreen cleaners. TRICO PRODUCTS CORPORATION. July 20, 1956 [July 22, 1955], No. 22581/56. Class 138(1). A vehicle having a windscreen 2, Fig. 1, with a frontal area 3 and a lateral area 4 joined by a relatively sharper corner portion forming a rest area 5, is providedwith a wiper 6 mounted on an arm 8, means 18 for oscillating the arm so as to move the wiper on its outward stroke up over the area 3, around the crest 5 and down over the area 4 and load modifying means 201, Fig. 12, serving to improve an additional load on the means 18 during the downward part of the outward stroke and to assist the means 18 during the upward part of the inward stroke. As shown in Fig. 1, the wiper arm 8 carrying a wiper blade assembly of known kind, is oscillated by a suction motor 18 and cables 19 connected to pulleys on the wiper actuated shaft. The pulleys 241, 25<SP>1</SP>, Fig. 14, are relatively adjustable on the wiper shaft 211 by means of interengaging teeth 31 and clamp nut (not shown). When the nut is slackened the slack in the cables 19 is taken-up by relative rotation of the pulleys under the action of a spring 32. The pulley 25<SP>1</SP> is provided with a hub 36 serrated at 35 to receive the serrations 34 in a retainer cap 33 secured on the hub by a C-ring 37 engaging in a groove 38 in the shaft 21<SP>1</SP>. The load-modifying means is in the form of a spring 201 surrounding the cap 33 and housed within a guard member 26<SP>1</SP>, Fig. 12, secured to a fixed bushing 221 for the shaft 211. One end 291 of the spring 20<SP>1</SP> is anchored to the cap between lugs 301 and 30<SP>11</SP> thereon, whilst the other end 281 is free and has a rubber sleeve 39. The guard member 26<SP>1</SP> has a shoulder 271 thereon covered by a sleeve 40. The arrangement is such that when the wiper is positioned on the frontal area of the windscreen the end 28<SP>1</SP> is always out of contact with the shoulder 27<SP>1</SP>. However when the wiper reaches the crest portion of the windscreen the sleeve 39 contacts the sleeve 40 and thereafter as the wiper moves outwardly and downwardly over the lateral area of the windscreen the spring 201 is wound-up and comprises a load on the driving motor 18. When the wiper moves inwardly and upwardly over the lateral area the energy stored in the spring 20<SP>1</SP> is released to assist the motor. By this arrangement a substantially constant load is maintained on the motor throughout its wiping strokes as described with reference to Fig. 15 (not shown). The loading of the spring during the wiping of the lateral area is determined by the relative positions of the cap 33 and hub 36. In another embodiment described with reference to Figs. 2 and 4 (not shown), the spring loading is not adjustable. If desired the load-modifying spring may be associated with the motor drive shaft or another interposed shaft of the drive mechanism, as described with reference to Figs. 10 and 11 (not shown). The wiper blade is maintained normal to the windscreen in the manner similar to that described in Specification 735,558. Specification 821,049 also is referred to.