GB374547A - An improved automatic friction clutch - Google Patents

Abstract

374,547. Free - wheel clutches ; variable-speed gearing. BOLTON, A., 13, Windy Nook Road, Gateshead, and ENGLISH, J., North Leam, Felling-on- Tyne. March 26, 1931, No. 9191. [Class 80 (ii).] An automatic free-wheel clutch, which may be used in motor vehicle variable-speed gearing, of the kind comprising a conical nut c<1> threaded on a shaft a and movable under the influence of the torque into frictional engagement with a coned female part h<1>, is provided with control means comprising three, or other number of, sunk keys d each with a projection el engaging a keyway in the nut at right-angles to its thread, so that axial movement of the key travels the nut on its thread. The nut can be disengaged, moved into such engagement that play of the projection e<1> in its keyway allows driving with free-wheeling, or moved further into engagement and locked there against disengagement by the projection. In the free-wheel position the key acts as a stop to keep the nut in light dragging contact with the part h ; and in the final position it acts as a wedge to prevent disengagement. One, two, three or more clutches cl, c<2> may be mounted on a common shaft and controlled by a common key d as shown in Fig. 3 or set of keys so that one clutch is engaged whilst the other is disengaged. The keys may be operated by an external sliding collar v, Fig. 4, or by a bar sliding within the shaft which is then hollow. The keys may slide helically and the key way in the nut be axial. In the four-speed gear shown in Fig. 4 two such clutches c<1>, c<2> are arranged on a driven shaft q and controlled through a selector fork w by a common key d to yield either direct-drive through clutch c<1> or third speed through a countershaft splined wheel t and clutch c<2>. In an intermediate neutral position, the key d holds both clutches c<1>, c<2> out of engagement. Second speed is obtained by engaging a countershaft automatic clutch c<3> by means of a key d<1> and first speed is through a sliding pinion o splined on the countershaft. There is an interlock between the operating rods x for the keys d, d<1> so that neither rod can be moved from the neutral position until the companion rod has been returned thereto. This interlock comprises a ball engaging recesses in each rod x. The automatic clutches are engaged through springs z so that the ratios may be preselected by the usual gate-guided lever, and rendered effective only on releasing the main clutch of the wheel or closing the engine throttle.