GB354711A - Improvements relating to overrunning devices for motor vehicles and the like - Google Patents

Abstract

354,711. Free-wheel clutches. LEGGE, N., Hall Orchard, Hexham, Northumberland. May 6, 1930, Nos. 13834, 19406, 25663, and 26245. [Class 80 (ii).] Synchronized overrunning devices for motor road or rail vehicles &c. comprise driving and driven members automatically coupled by a claw clutch adapted to be uncoupled on overrunning, operation thereof being effected by an auxiliary positive unidirectional drive operated by the driving or driven member and controlling an intermediate member, which is provided with one of the sets of claws and is axially movable on helical splines &c. on the driven or driving member, means being provided to ensure correct rotational positioning of the claws on synchronization and to prevent transmission of torque through the auxiliary one-way clutch. An intermediate member d, Fig. 1, is free to move on a quick-pitch thread b<1> between a collar b<2> and shoulder b<5> on the driven part b, and has clutch teeth d<1> to engage teeth a<1> on the driving- member a, these teeth being, if desired, slightly inclined to facilitate engagement. The teeth d<1> also extend inwardly to engage keys or fingers e<1> on the part e of a controlling-member, the other part e<2> of which carries a pawl f to engage ratchet teeth a<3> on the member a. When the member a tends to overrun the member b, the auxiliary ratchet clutch f, a<3> transmits rotation to the member d, causing it to move into engagement against a spring d<2>, which disengages it when the part b overruns. The pawl f and teeth a<3> are so designed that the teeth d<1>, a<1> are correctly placed for engagement at the end of the travel of the sleeve d. In order that the load shall not be taken by the pawl, the parts e, e<2> of the controlling-member are connected by conical pins e<3> and recesses e<4> under spring pressure so that they have sufficient rotational yield to allow for working clearance between the main clutch teeth. Bidirectional drive is provided by engaging teeth a<2> with teeth a<1> on a sleeve c, splined at c<2>, b<3> to the driven member and actuated by a fork &c. g<1>. Fig. 2 shows a modification in which the sleeve d moves to the right to bring the teeth d<1>, a<1> into engagement, the teeth c<1> of the bidirectional clutch member c then being engageable with teeth d<3> thereon without shock. The controlling-member e is in one piece, being connected to the sleeve d by pins e<5> and holes d<4>, the relative positions of which may be interchanged. In order to provide rotational freedom, the pins are partly tapered, as shown, or made of spring steel or other slightly flexible material. The member c may be spring-pressed to the left to provide normal bidirectional drive until manually withdrawn. In order to remove the pawl f from contact during overrunning, the drag-effect of a ball or roller bearing may be used, the outer race being secured to the driving-member a and the inner race to a floating bush having a peg or tongue h3, Fig. 4, coacting with the tail of the pawl f. When the driving-member overtakes, the tongue h<3> is shifted and the pawl thrown out by a light spring k or a second peg or tongue. In a further modification, the controlling-member may be unidirectionally connected to the clutch sleeve d and slidably connected to the driving-member. The functions of the driving and driven members and the positions of the pawl and ratchet teeth may be interchanged, and the screw-thread b<1> may be replaced by a cam.