GB1364539A - Overrunning brake installations for trailers - Google Patents

Abstract

1364539 Brake transmitting mechanism; over-run and hand actuation KOBER MANPAR AG 23 Nov 1971 [27 Nov 1970 12 Feb 1971] 54411/71 Heading F2E An actuating device for an over-running trailer brake, such brake being preferably as described and claimed in Specification 1,364,540, divided from the present Specification, comprises a hand-brake lever, an over-running selector device, and linkages connecting the hand-brake lever and selector device to a common joint which is connectible to the mechanically-actuated expanding device of the brake, the linkage connecting the hand-brake lever to the common joint including a compression spring, and the hand-brake lever being capable of sufficient swivelling movement to cause further displacement of the common joint after displacement of the common joint by the overrunning selector device. As shown, a pull rod or plunger 35, longitudinally displaceable in a housing 36, acts on a reversing lever 37 pivotable at 38 in the housing. Linked to the reversing lever 37 is linkage 39 (a stirrup of U-section) provided with a hinge bolt 40 to which a brake-operating cable 41 is attached. A hand brake lever 44 is also pivoted at 38. A rod 48 is slidable in a bolt 46 on the lower arm of hand brake lever 44, and engages, by a head 50, a spring 49 whose other end is engaged by a restriction 51 of a casing 47 (these parts constituting another linkage). In operation, on over-running of the trailer, pull rod 35 moves to the right relative to housing 36, so lever 37 is swivelled clockwise, thereby applying the trailer brakes. The connection between handbrake lever 44 and the brakes is not affected, so the lever remains in the position shown in full lines in Fig. 6 (because bolt 40, which extends through casing 47, pushes the casing and rod 48 to the left, but rod 48 slides through bolt 46). The same sequence occurs when the trailer is reversed by the towing vehicle, but for reasons given in the Specification the trailer brakes are not then applied. When the handbrake lever 44 is rotated, rod 48 is entrained by nut 46 (via head 52), spring 49 is compressed, and the brakes are applied via casing 47 and hinge bolt 40. Simultaneously linkage 39 is moved by bolt 40, and in turn, lever 37 is swivelled clockwise, coming away from pull rod 35. Hand-braking of reversed trailer. - When the trailer has been reversed and the over-running device has moved the linkages, without applying the brakes, to the positions described in an earlier paragraph, the handbrake lever (which has an exceptional range of movement), on being rotated to its limit position shown dotted in Fig. 6, is able to entrain rod 48 and move it still further to the left. The ensuing extra movement imparted to cable 41 serves to apply the brakes, when the brakes are such as have been referred to earlier.