US 4,287,972 A · Automatic clutch assembly

Abstract

A locking gear in the form of an annular, slotted cam member causes a driving member to move into locking engagement with a member to be driven automatically in response to the application of torque or positive rotation to the driving member. The driving member can be disengaged only by removing torque from the driving member and reversing the direction of rotation of the driven member without relying upon spring force for disengagement. Accordingly, the driving member is not only forcefully cammed into engagement with the member to be driven but is mechanically and positively cammed into disengagement at the will and under the full control of the operator. Thus in four-wheel drive vehicles, the wheels or members to be driven are selectively engaged by a drive gear which is slidably advanced through interengagement of cam followers on the drive gear with camming surfaces on the locking gear. In one form, the camming surfaces may be inner and outer concentric cam surfaces which cooperate to simultaneously control the axial displacement of the driving member into engagement with the member to be driven and to positively cam the driving member in a return direction away from engagement with the member to be driven when torque is no longer applied to the driving member and the member to be driven is reversed in rotation.

Claims24

Dependent claims

In a clutch assembly, an actuator mechanism operative to effect releasable but positive driving engagement between a member to be rotated and a rotatable drive member, said actuator mechanism comprising:

first actuating means including a cam follower rotatable in response to positive rotation of said drive member;
second actuating means releasably locked against rotation and provided with first cam control means operative to advance said first actuating means into engagement with the member to be driven, second cam control means engageable by said first actuating means to release said second actuating means for rotation upon engagement between said first actuating means and the member to be driven, and third cam control means engageable by said first actuating means when said drive member is no longer positively rotated and the member to be driven is reversed in its direction of rotation with respect to said drive member whereby to return said second actuating means to its locked position and to disengage said first actuating means from driving engagement with the member to be driven.

A clutch assembly adapted to selectively and automatically engage and disengage an outer hub and wheel member in a four-wheel drive vehicle with respect to an inner concentric drive axle, said inner concentric drive axle mounted for rotation within a stationary axle housing and having a splined end portion projecting outwardly from one end of said drive axle, said clutch assembly comprising:

an actuator mechanism interposed between the splined end portion of said drive axle and said outer hub, said actuator mechanism including an annular drive gear keyed for rotation on said splined end portion and having at least one radially outwardly projecting drive lug thereon and a series of axially extending, circumferentially spaced tooth members on its external surface;
a driven gear connected to said outer hub for rotation therewith and having a series of internally projecting teeth arranged at spaced circumferential intervals and adapted to intermesh with said external teeth on said drive gear;
and
inner and outer concentric cam ring members disposed in outer concentric relation to said drive gear, said cam ring members each provided with first, second and third bearing surfaces engageable with said drive lug, one of said inner and outer cam ring members being releasably locked against rotation to said axle housing, and the other of said cam ring members being fixed against axial displacement, said first bearing surface engageable with said drive lug to advance said drive gear axially into intermeshing engagement with said driven gear in response to positive rotation of said drive axle, said second bearing surface engageable with said drive lug upon movement of said drive gear into intermeshing engagement with said driven gear to axially advance said one cam ring member away from locked engagement with said axle housing, and a third bearing surface engageable with said drive lug in response to the removal of positive rotation of said drive axle and the reversal of rotation of said outer hub with respect to said drive axle whereby to axially retract said drive gear away from intermeshing engagement with said driven gear and to retract said one cam ring member to its normally locked position with said axle housing.

1 more element

Dependencies are inferred from the claim text.

Automatic clutch assembly

Life of this patent

Automatic clutch assembly

Life of this patent

Abstract

Claims24