Patent GB-433726-A (GB)
Title: Improvements in and relating to braking means used with bogies for travelling suspended cars, aircraft or the like
IPC: B60T1/04
Filed: 1934-02-21
Abstract: 433,726. Skid brakes for vehicles. FRASER, H., 3, Blairbeth Terrace, Burnside, Rutherglen, Lanarkshire. Feb. 21, 1934, No. 5698. [Class 103 (i)] Brake mechanism for bogies for travelling cars, aircraft &c. suspended from an overhead track having upper and lower rails comprises service and emergency brakes, each comprising a pair of shoes operated by equalizing or compensating mechanism the arrangement being such that the shoes of a brake are applied simultaneously and conform to the rails irrespective of irregularities therein or in their distance apart. The emergency brake may be spring-applied. The car is carried by fore and aft bogies each of which comprises a frame 1 and springs 4 from which is suspended by links 9 the member 11 attached to the car. The brakes are mounted on a pair of brackets 12, 12<1> suspended directly from the frame 1 by links 13, 13<1> and connected by spacing bars 14, 15. Vertical pins on the main suspension member 11 pass through the bars 14, 15 to permit vertical but not horizontal movement of this member relatively to the bogie. The brackets 12, 12<1> also carry wheels 18 which take the weight of the car should the springs 4 fail. The service brake comprises a pair of brake shoes 22 for engagement with upper and lower rails 3, 3<1> each shoe being pivotally mounted upon a pair of arms or trunnions 21 pivoted respectively to lugs 19, 20 on the bracket 12. The trunnions are actuated by levers 23 mounted on the lugs 19, 20 on the same pivot as the trunnions and connected to them. A lever 24 is connected directly to the upper lever 23, to the lower lever 23 by a link 25 and by a link 26 to a bell-crank 27, 28 pivoted to the lug 20. The emergency brake comprises a similar arrangement of shoes 22<1> and similar operating connections 23<1> .. 281 except that the lever 24<1> is connected to the lever 23<1> at an intermediate point. The operating mechanism for the lever 28 comprises a hand winch or power means in the car between which and a compensating lever 32, Figs. 6, 8 extends a cable 31. One arm of the lever 32 is connected by link 33 and lever 34 to a vertical shaft 35 extending outside the car where it is connected by a link 37 and rod 38 to lever 28, the rod 38 passing through a guide 39. The other arm of lever 32 is connected by a rod 40 with an interposed spring 41 to a cable 42 leading to the corresponding lever and shaft 34, 35 for the brake on the rear bogie. A release spring 43 is connected to lever 34. The spring 41 may be pre-set to the maximum force to be applied to the brakes but yields to permit accommodation of the shoes to local variations in depth or thickness of the rails or rail bearers. The operating mechanism for the emergency brakes comprises a pair of application springs 49, Fig. 10, arranged one on each side of and connected eccentrically at 50 to a pulley 46, to which is secured a cable 44 connected to a winch or other means in the car by which the springs are compressed to release the brake. The arrangement is such that the turning moment of the springs about the pulley centre remains substantially constant with variation of the compression of the springs. A second cable 48 attached to the pulley 46 extends to a compensating lever 51 one arm of which is connected by link 53, lever 54, shaft 55, lever 56, link 371 and rod 381 to emergency brake lever 28<1> of the forward bogie while the other arm is connected by rod and cable 57, 58 to the corresponding lever 54 of the brake of the rear bogie. A release spring 59 is connected to the lever 54 and a dash-pot 52 prevents sudden application of the brakes. Specification 328,946, [Class 103 (i)], is referred to.