Patent GB-143856-A (GB)
Title: Improved automatic regulating apparatus for transmitting motion, more particularly applicable for adjusting the slack in brake mechanism
IPC: B61H15/00
Filed: 1920-05-21
Abstract: 143,856. Soc. de Construction et de Location d'Appareils de Levage et de Materiel de Travaux Publics. May 23, 1919, [Convention date]. Compensating for wear.-Relates to automatic means for adjusting motion-transmitting mechanism, particularly for compensating for the wear of the brake blocks in brake mechanism, in which an adjustment of length is permitted by a nut free to traverse a screw of quick pitch in one direction only. According to the invention the engagement of the screw-and-nut member with the member to which it is connected takes place only after a definite delay, such delay determining for example the play between the brake block and the wheel. In one form, Fig. 1, the nut 2 works on a screw 1 and is free to slide to a limited extent in a shackle 3. If a force tending to shorten the distance 5, 6 is applied, the nut 2 abuts against the shackle 3 after the play between these two parts has been taken up, and being free to rotate traverses the screw member 1. A tendency to lengthen the distance 5, 6, apart from the play between the members 2, 3, is however resisted since the contacting surfaces 4 of these members on the other side of the nut are roughened and prevent rotation thereof. Fig. 4 shows a form in which the distance between two points 5, 6 is free to lengthen and in which a screw stop 8 is provided for adjusting the play between the members 2, 3. Fig. 5 shows an application of this form in which the brake piston a and a lever d are respectively connected to the shackle 3 and screw 1 of the device b, the lever d being connected also to the shackle of a second device g of which the screw 1 is connected to a fixed point h. In an application of the brakes. the shackle 3 of the device g is first displaced relatively to the nut 2, and then the roughened surfaces of these members engage and actuate the lever d. If, owing to wear of the block f, the clearance between it and the wheels exceeds the play between the shackle 3 and nut 2 of the device g, these members contact and the nut traverses the screw. The return movement of the lever d, however, is permitted only to the extent of the play between the members 2, 3 of the device g by reason of the engagement of the roughened surfaces 4 of these members; the nut 2 of the device b is accordingly traversed along its screw to a certain extent by the shackle 3 as the piston returns to its initial position. In another arrangement, a pair of brake blocks acting upon a single wheel are connected each to the lower end of a pair of levers disposed between the blocks. One of the adjusting-devices, of the form shown in Fig. 1, is connected between the lower ends of the levers and another between two intermediate points on the levers, the upper ends of which are moved apart to apply the brakes. According to the Specification as open to inspection under Sect. 91 (3) (a), the device may be applied also as shown in Fig. 7 (Cancelled) and Fig. 9 (Cancelled), and to tramcar brakes of the kind comprising a brake beam and an equalizing-beam at each end of the car and tension-rods conecting the two equalizing-beams, the adjusting-devices in this case being shown as interposed between the equalizing-beam and the brakebeam at each end of the car. This subject-matter does not appear in the Specification as accepted.