Patent GB-775052-A (GB)
Title: Cooling arrangement for brake mechanism
IPC: F16D55/228
Filed: 1955-04-25
Abstract: 775,052. Cooling brakes; vehicle wheels. SANFORD, R. S., EATON, W. A., SEDERGREN, E. D., CASLER, R. H., and EAMES, J. O. April 25, 1955 [May 3,1954], No. 11810/55. Classes 103 (1) and 144 (2). [Also in Group XIII] In a friction brake a pair of relatively rotatable friction elements are mounted for movement into frictional engagement with each other, one of said elements including a member having one facing of substantially non-metallic sheetinsulating friction material and the other element having a hollow chamber for cooling fluid provided with inlet and outlet ports for receiving and discharging a cooling fluid, and a member formed of copper-based material forming one wall of the chamber, the outer surface of said member being positioned for engagement with the friction material and the inner surface of said member being in contact with the cooling fluid in the chamber. In the embodiment illustrated in Figs. 1 and 2 an internal shoe-drum brake for a motor vehicle is provided with a brake to which is secured at its drum inner annular surface a substantially non- metallic friction lining 10 of heat-insulating material. The brake shoes 12 are of composite construction comprising a cavity 27 bounded by an arcuate U-shaped section 26, 30 of steel, the open side of the cavity 27 being closed by a friction element 31 of copper-based material consisting of at least 99 per cent pure copper. Transverse grooves 91 may be provided across the outer surface of the friction element to minimize distortion effect. The shoes 12 are provided with a frictional connection with, and mounted on, floating anchor links 13 pivotally secured to the back plate 5; the upper end portions 18a of the shoes being forced apart to bring the friction surface head 31 of the shoes into frictional contact with the drum by means of a conventional hydraulic wheel brake cylinder 20. Cooling liquid, e.g. water, may be circulated to the brake shoe by means of a power driven circulating pump 35 from a radiator 34 through conduits 37, 39, cavity 27 in brake shoes 12, through conduits 40, 42 to the radiator. In the embodiment illustrated in Fig. 3 a disc brake is provided with a brake disc 45a attached to the rim of a wheel hub 44 rotatable on axle tube 43. Friction discs 47 of substantially non- metallic heat-insulating brake lining material are secured to either side of brake disc 45a and the brake actuator carriers 48, 52 rigid with the axle tube 43, carry annular pistons 59, 60 respectively which, when supplied through conduits 57 with fluid pressure via conduit 58 from a brake master cylinder (not shown), are moved towards the brake disc 45a to bear against annular brake shoes 61 and 62. Each brake shoe 61, 62 is constructed of a steel or cast iron annular U-shaped member 65 and formed with a continuous cavity 66 closed by an annular friction element 70 of pure copper; the shoes 61, 62 being secured to spring steel shoe-supporting elements 49, 51 respectively, which are rigidly secured to the axle tube 43. Liquid may be circulated through cavities 66 in the brake shoes 61, 62 by means of conduits 73, 74, 75 and contuits 79, 77, 78 to a radiator circuit similar to that illustrated in Fig. 1. A dust shield 80 is attached to brake actuator carrier 48 to seal the brake assembly against the entrance of dirt and water. The embodiment illustrated in Fig. 7 shows an application of the invention to aircraft brake wherein a liquid cooled brake shoe 92 having a copper-based friction element 93 is adapted to engage a non-metallic brake lining 94 secured to the inner surface of a disc rim 95, thus dispensing with the normal brake drum. The Specification lists details of brake tests results both on dynamometer tests rigs and on vehicles on the road.