EASY CHANGING.

Press, Volume LXVIII, Issue 20563, 3 June 1932, Page 6

EASY CHANGING.

SUPERCESSION OF GEARBOX. ! Engineers for the past few years have been concentrating much study on methods by which the conventional gearbox —a makeshift in the first instance, and never regarded as a satisfactory solution of the part it has to play in the transmission system—can be superseded. Bome excellent devices have been introduced, but for the most part they are complicated and costly, and none has come into general us© except what is known as the silent third or twin high box, which, while it has provided two riming gears with an easily effected change, has not got over the initial difficulty of the change up and change down in the lower range. Inventors have consequently been inclined to desert the conventional type of box altogether. That there is no need to do so seems to be proved by a new and simple device developed in Britain and protected there and in the States. Jt consists in employing two very thin gear wheels mounted against the lace of the layshaft gear and cut with teeth of similar "shape and pitch. These two thin wheels are lightly pressed n gainst a ring of friction fabric, and pegs secured to one of them pass through slots cut m the other. The result is that the teeth of the two thin gears are allowed a small amount of relative movemen , such that they may either coincide or may move to the extent of about half a witch, the teeth of the first small wheel then coming opposite the gaps m the other. This other is in fnctional contact with the layshaft gepr, and the arrangement is such that when the gear change is being made only a ve 'y short period elapses before the speeds of the parts synchronise and the sliding gear can slip through into engagement. Double declutching is unnecessary in making downward changes, but in practice it has been found desirable to increase the speed of tne engine to effect a rapid and smooth change.

POWERFUL CAR. .The cabled announcement from Paris tli.it the special racing car built by M. Stapp, a French engineer, with a view to capturing from Britain the world's land speed record, has come to grief while being tried out on La lioule beach (France), adds yet another failure ,to the long list of optimistic aspirants who have set out with high hopes of capturing this classic* record. Tho Stapp machine was fitted with three 800 h.p. engines—24oo h.p. in 'l—and weighed BJ tons, whereas the IJlue Bird, driven by Sir Malcolm Campbell, when he registered 253.06 m.p.h. at Daytona Beach (U.S.A.) last February, bad one 12-cylirder engine developing 1400 h.p., .m«l weighed about three tons..