Patent GB-670333-A (GB)
Title: Improvements in or relating to windscreen wiper blades
IPC: B60S1/42
Filed: 1948-10-26
Abstract: 670,333. Windscreen cleaners. 0'SHEI, W. E. Oct. 25, 1949 [Oct. 26, 1948], No. 27845/48. Class 138 (i). A windscreen wiper blade is constructed with a squeegee member secured in a rigid backing member or a plurality of rigid backing members arranged along the back of the squeegee, the wiping edge of the squeegee member being curved in the plane of the member along the, or each, length of the member embraced by the, or a, backing member. A squeegee member of stepped plies of rubber or like material is formed of outer plies 2 and a central or wiping ply 2', all secured in a rigid channelshaped metal backing member 1. The wiping edge of the ply 2<SP>1</SP> is cut or shaped to a uniform curvature from one end to the other preferably corresponding to the maximum curvature of the windscreen 4. In order that the wiper blade,may work' from side to side as it moves over the windscreen so as to assume a trailing position thereon, the backing member 1 is pivotally connected to lugs 7, on a bridge piece 6, passing through apertures 8 in the back of the member 1, by means of a rod 9 extending within the member 1 and passing through apertures in the lugs 7. The bridge piece has side walls which at their end regions embrace the sides of the member 1. The centre of the bridge piece 6 is formed with an aperture.11 to receive the down-turned end 12 of the wiper arm 5. The end 12 which is.provided with a dimple 23 also passes through an aperture 22 in a spring urged slider 13. The slider 13 is formed with lateral lugs which pass through slots in the side walls of the bridge piece 6, which lugs facilitate the movement of the slider against its spring to release the end 12 and dimple.23 from the aperture 11. By making the aperture 11 of sufficient size the blade is enabled to rock to an inclined position with respect to the arm when the blade touches the frame of the windscreen. Means may be provided for positively reversing the direction of trailing when the direction of movement of the blade changes. In a modification means may be provided for varying the angle of trailing as the blade moves across the screen e.g. the angle of trailing may increase as the blade moves through its vertical position and to reduce, preferably continuously, as the blade approaches its limiting positions of movement. In a further modification the blade may comprise two or more backing members secured along the back of a single squeegee the various backing members being interconnected by a bridge member. The wiping edge in this case need not be in the form of a continuously uniform curve but may be cut to two or more curves, for example with a deeper portion in the middle as well as at the ends. In all the above forms the blade need not be of stepped multi-ply form but could be constructed with a single strip or plurality of strips all of 1 he same size or the squeegee may be moulded or extruded to the desired cross-section. In the case of the multi-ply blade the free edges of the outer plies may be straight or curved. Furthermore the backing member may have a curved back. Specification 657,822 is referred to.