GB378380A - Improvements in brakes - Google Patents

Abstract

378,380. Electric brakes. BARKER, G. G., 59, Chancery Lane, London.-(Bendix Brake Co. ; 401, North Bendix Drive, South Bend, Indiana, U.S.A.) April 30, 1931, No. 12753. [Class 103 (i).] Brake mechanism comprises a pedal directly connected to the brakes by mechanical linkage including an electric controlling device, Fig. 7, controlling an electric power device, Figs. 2 and 3, to vary the brake-applying force of this power device in direct proportion to the brakeapplying force mechanically transmitted by the controlling device. Pressure on the brake pedal applies the brakes directly and produces pressure on the carbon disc rheostat, Fig. 7, which 'allows current to flow to an electromagnet or to the motor, Figs. 2 and 3, which is adapted to swing an arm 20 connected to the brakes through a limited arc. The rheostat, Fig. 7, comprises carbon discs 55 contained in a tube 53 lined with insulation 54. Bolts 62 hold endplates 59, 60 on the tube and a member 71 spaced by tubes 70 from the plate 60. The member 71 is connected by a lug 52 to the brakes. A plate 72 carrying a metal plug 77 adapted to contact the carbon discs is provided with holes through which extend bolts 63 passing through ears 61 in the endplates and screwed in a member 75 connected to the brake pedal. Operation of the brake pedal compresses springs 73 on the bolts 63 and presses the carbon discs into contact with one another which lessens the resistance. Metal endplates 56, 57 are arranged at each end of the carbon discs, and plate 57 has a binding post 58 riveted thereto insulated by discs 67 from the end plates. Washers 64 insulate the discs from the endplates. The motor which operates through part only of a revolution comprises a bipolar field core formed by bars 24, Figs. 2 and 3, bent to semicircular form with the ends turned in and welded at 26 to form poles 27 provided with winding 32. In grooves in the bars 24 fit bearing heads 30 held by bolts 31. The armature core comprises bars 33 bent to V-form machined at 34 to form magnetic joint and secured together by bolts 35 and dowels 36. Journal heads 40 fit in grooves 39 and are held by screws 41 to the armature core. The armature coil 42 is wound on an insulating spool 43, surrounding the core. The armature oscillates on journals 44 secured in the journal heads 40. The current is conveyed to the armature and field windings through leads connecting the coils to binding posts 45. The leads 46 from coil 42 being brought through the heads 40 as near to its centre of rotation as possible. The lever 20 of the motor is considerably shorter than the lever of the transmission to which it is connected to give increased leverage and so that the rotation of the motor can be limited to 90‹.