Self-modulated input clutch for vehicle drive transmissions

Claim 2

A clutch for coupling a vehicle engine to an input of a change speed gear box of said vehicle, comprising: a rotatable input member having means for connection to said engine and having means defining a chamber for containing a fluid volume wherein centrifugal force generates a pressure within said fluid which is a function of engine speed, a driven member having means for connection to said change speed gear box input, a plurality of input clutch plates including at least one driving plate coupled to said input member and at least one driven plate coupled to said driven member, an input clutch capacity modifying member exposed to said fluid pressure of said chamber of said input member and being movable in response to increases of said pressure to produce a force tending to engage said clutch plates, at least one engagement spring acting between said capacity modifying member and said clutch plates to transmit said engagement force therebetween, at lease one disengagement spring acting against said capacity modifying member to resist said movement thereof to prevent engagement of said clutch plates until said fluid pressure reaches a predetermined low value which is greater than the value corresponding to the idling speed of said engine, whereby said gearbox input is decoupled from said engine at said idling speed thereof, and a stop blocking said movement of said capacity modifying member after said fluid pressure reaches a value which is intermediate between said low value and a value corresponding to maximum engine speed whereby changes of said fluid pressure change the capacity of said clutch at lower engine speeds only and the capacity of said clutch is substantially constant and determined by said engagement spring after said movement of said capacity modifying member is blocked by said stop.

Claim 3

The combination defined in claim 1 further comprising fluid signal actuated means for relieving the force of said capacity modifying member against said input clutch plates to disengage said clutch plates for facilitating shifting of said gear box at engine speeds above said idling speed thereof.

Claim 4

A clutch for transmitting torque from a vehicle engine to the input of a change speed gear box transmission of said vehicle, comprising: an annular rotatable input member having means for connection to said engine and having means defining an annular liquid retaining chamber whereby centrifugal force generates a fluid pressure in said chamber which is a function of the rate of rotation of said input member, an annular driven hub disposed coaxially with respect to said input member and being drivingly coupled to said transmission input shaft, a pack of annular input clutch plates disposed coaxially with respect to said input member, said pack having at least one driving plate constrained for rotation with said input member and having at least one driven plate constrained for rotation with said driven hub, an annular pressure plate disposed coaxially with respect to said clutch plates for exerting a force thereon tending to engage said driving and driven plates thereof, aN annular clutch capacity modifying member disposed in said chamber of said input member and exposed to said fluid pressure therein, said input clutch capacity modifying member being movable axially in response to changes of said fluid pressure, at least one engagement spring acting between said capacity modifying member and said pressure plate for exerting a force on said pressure plate tending to engage said input clutch plates, at least one disengagement spring acting on said capacity modifying member in opposition to the force of said fluid pressure thereon whereby said engagement spring is ineffective to engage said input clutch plates until said fluid pressure reaches a first predetermined level, and stop means blocking movement of said capacity modifying member in response to increasing fluid pressure after said fluid pressure reaches a second higher predetermined level whereby changes of said fluid pressure affect the capacity of said clutch only at an intermediate range of engine speeds, said capacity being substantially constant and being determined by said engagement spring at the highest range of engine speeds.

Claim 5

A clutch for transmitting torque from a vehicle engine to the input of a change speed gear box transmission of said vehicle, comprising: an annular rotatable input member having means for connection to said engine and having means defining an annular liquid retaining chamber whereby centrifugal force generates a fluid pressure in said chamber which is a function of the rate of rotation of said input member, an annular driven hub disposed coaxially with respect to said input member and being drivingly coupled to said transmission input shaft, a pack of annular input clutch plates disposed coaxially with respect to said input member, said pack having at least one driving plate constrained for rotation with said input member and having at least one driven plate constrained for rotation with said driven hub, an annular pressure plate disposed coaxially with respect to said clutch plates for exerting a force thereon tending to engage said driving and driven plates thereof, aN annular clutch capacity modifying member disposed in said chamber of said input member and exposed to said fluid pressure therein, said input clutch capacity modifying member being movable axially in response to changes of said fluid pressure, at least one engagement spring acting between said capacity modifying member and said pressure plate for exerting a force on said pressure plate tending to engage said input clutch plates, at least one disengagement spring acting on said capacity modifying member in opposition to the force of said fluid pressure thereon whereby said engagement spring is ineffective to engage said input clutch plates until said fluid pressure reaches a first predetermined level, and stop means blocking movement of said capacity modifying member in response to increasing fluid pressure after said fluid pressure reaches a second higher predetermined level whereby changes of said fluid pressure affect the capacity of said clutch only at an intermediate range of engine speeds, said capacity being substantially constant and being determined by said engagement spring at the highest range of engine speeds.

Claim 6

The combination defined in claim 3 wherein said input of said transmission is a shaft extending along the axis of rotation of said input member and has a passage with a radially directed outlet for supplying oil to said chamber of said input member whereby said oil is trapped in said chamber by centrifugal force to produce said fluid pressure.

Claim 7

The combination defined in claim 3 further comprising an annular plate disposed coaxially with respect to said clutch pressure plate and being movable axially between a first position at which said annular plate urges said pressure plate against said clutch pack and a second position at which said annular plate urges said pressure plate away from said clutch pack, said annular plate being capable of a limited amount of free travel between said first and second positions, said engagement spring acting between said annular plate and said capacity modifying member to exert said engagement force on said pressure plate by urging said annular plate towards said first position, said combination further comprising means for forcing said annular plate to said first position thereof to relieve the force of said engagement spring on said clutch pack whereby said transmission may be shifted.

Claim 8

The combination defined in claim 3 wherein the output element of said vehicle engine is a rotary flywheel having a plurality of passages spaced angularly around the axis of rotation thereof and directed in parallel relation to said axis and wherein said input member of said clutch is disposed adjacent said flywheel in coaxial relationship therewith, and wherein the means coupling said input member to said flywheel comprises a plurality of cylindrical buttons secured to said input member and extending therefrom into said passages of said flywheel.