GB503776A - Improvements relating to electro-magnetically operated brakes - Google Patents

Abstract

503,776. Electromagnetically - operated brakes. SCOTT, W. Oct. 11, 1937, No. 27631. [Class 103 (i)] In a brake of the kind wherein a pair of brake shoes is operated by the armature of an electromagnet through a tapered member engageable between the shoes, the tapered member is mounted with play transversely of its direction of movement to permit of its self-alignment in relation to the shoes. In Figs. 3, 4, a pair of shoes 4 are pivoted at 6 on a back-plate 1 which may be secured to or form the cover of an electric motor. A bracket 13 extending from the plate 1 and around the drum and shoes carries a magnet 25 of E-form the armature 24 of which is mounted on a plate 19 pivoted at 21 on the back-plate. A tapered pin 17 on the plate 19 engages between rollers 8 on the shoe-ends. The shoes are applied to a drum 2 on the shaft 3 by springs 11 abutting on the shoe-ends and on ears 12 of the bracket 13. When the magnet is energized the shoes are disengaged by the pin 17 and engage adjustable stops 14 screwed into the ears 12. The pin 17 has an increased taper at its extremity to effect quick disengagement of the shoes. Lateral movement of the pin 17 to ensure equal release displacement of the shoes is allowed by providing clearance between the ears 20, 22 of the pivotal mounting of the plate 19. The armature 24 has a pivotal connection 29 with the plate 19 to permit self-alignment of the armature with the magnet. Upward movement of the plate and armature is effected by a torsion spring on the pivot 21 and is limited by a stop 27, 28. In a modification, Fig. 7, the magnet 30 is mounted on the plate 1 directly above the drum and the armature 33 and tapered' pin 31 are carried by a plate 34 mounted through springs 37 on the magnet, the pins 35 being free in the plate to permit lateral movement of the pin 31. In a further construction, in which the armature is pivoted similarly to the arrangement of Fig. 3, the armature and magnet are mounted directly on the .motor casing and are disposed between the armature pivot and the tapered pin the upper end of which extends into a socket on the armature-carrying plate. To permit the lateral movement of the lower part of the pin the upper part is rounded and bears on a similarly rounded part in the socket.