BRAKE SHOES.

Auckland Star, Volume LXIX, Issue 126, 31 May 1938, Page 16

BRAKE SHOES.

FRICTION PROBLEMS. Many a mechanic, when refacing a brake shoe, must have thought to himself: "Surely all these rivets are unnecessary,; whe'n the fabric is being tightly pressed against the shoe by the brake drum and the only tendency is for the facing to turn with the drum." The reasoning is sound, for the friction between the shoe and the facing little, if any, less than that between the facing and the drum. Possibly ~a similar thought, together with an appreciation of the advantages resulting from the elimination of rivets, prompted an English manufacturer of brakes In the development of its new rivetless facing. In this case, there is a slotted steel strip, on to which the fabric is woven, the whole being compressed, under heat, to form a unit. Refacing a shoe involves simply the attachment of the steel strip to the shoe by fOljr small bolts. Tie scheme permits all the fabric to be worn away before refacing, and much simplifies this operation.

INFLATION AND ECONOMY.

Recent research has revealed that, when a motor car or truck is driven with its tyres under-inflated by 10 per cent, the tyre wear increases by 13 per cent. Thus, if tyres that should be run at 301b pressure are run at 271b, the tyres 'will show as, .-much wear after travelling 870 miles as they would after running 1000 miles at the correct inflation pressure. From this, it will be seen that tyre economy and inflation are closely allied. j