Proportioning device

Claim 2

A brake pressure control device for use in a vehicle hydraulic brake system comprising: a housing having fluid inlet adapted to receive fluid from a source of fluid pressure, a fluid outlet through which fluid is adapted to be displaced to a brake cylinder, and a fluid chamber for providing communication between said inlet and said outlet; means in said chamber for movement in response to fluid pressure at said inlet above a first predetermined pressure to decrease the transmission of fluid pressure from said inlet to said outlet; an annular member in said fluid chamber arranged coaxially of and surrounding said means adapted for movement to provide an additional passage for traNsmission of said pressure from said inlet to said outlet in response to a second higher predetermined fluid pressure at said inlet for influencing the decrease in the transmission of fluid pressure provided by said device, a resilient valve member between said inlet and said outlet; a valve portion on said means in said chamber cooperating with said resilient valve member to provide said interruption of said pressure transmission from said inlet to said outlet at said first predetermined pressure; the position of said valve member being controlled by said first mentioned member for movement in accordance therewith at said second predetermined fluid pressure at said inlet, and movement of said resilient member in response to decreasing fluid pressure at said inlet above said second predetermined fluid pressure causing said resilient member to sealingly engage said means and a relatively fixed element in said housing to provide a reduction in pressure at said outlet.

Claim 3

A brake pressure control device according to claim 1 wherein said member is an annular member coaxially disposed with said means in said chamber.

Claim 4

A brake pressure control device according to claim 2 wherein said member surrounds said means in said chamber.

Claim 5

A brake pressure control device according to claim 1 wherein said means in said chamber has a first total area exposed to fluid pressure at said inlet and a second total area greater than said first area exposed to fluid pressure at said outlet, the ratio of said first and second total areas being established so as to provide movement of said means in response to said fluid pressure at said inlet.

Claim 6

A brake pressure control device according to Claim 4 wherein said member is adapted for movement away from said inlet in response to a pressure drop across said member.

Claim 7

A brake pressure control device for use in a vehicle hydraulic brake system comprising: a housing having fluid inlet adapted to receive fluid from a source of fluid pressure, a fluid outlet through which fluid is adapted to be displaced to a brake cylinder, and a fluid chamber for providing communication between said inlet and said outlet; differential area means in said chamber sealingly engaging the walls thereof and providing fluid communication from said inlet to said outlet, said differential area means being adapted for movement in response to fluid pressure at said inlet to decrease the transmission of fluid pressure from said inlet to said outlet; resilient means for exerting a force on said differential area means for preventing movement of said differential area means and consequent decrease in the transmission of fluid pressure thereby below a first predetermined fluid pressure at said inlet and for yielding to allow movement of said differential area means to decrease the transmission of fluid pressure from said inlet to said outlet above said first predetermined fluid pressure at said inlet; a member in said fluid chamber separate from said differential area means being adapted for a predetermined movement in response to fluid pressure at said inlet for influencing the decrease in the transmission of fluid pressure from said inlet to said outlet; and resilient means for exerting a force on said member for providing said predetermined movement of said member which influences the transmission of fluid pressure from said inlet to said outlet above a second higher predetermined pressure at said inlet, a first valve portion between said inlet and said outlet; a second valve portion on said differential area means in said chamber engageable with said first valve portion to provide said interruption of said pressure transmission from said inlet to said outlet at said first predetermined pressure; said first valve portion being movable at said second predetermined fluid pressure at said inlet, movement of said first valve portion in response to decreasing fluid pressure at said inlet above said second prEdetermined fluid pressure providing a reduction in pressure at said outlet, said first valve portion being sealingly engageable with both said second valve portion and a fixed element in said housing.

Claim 8

A brake pressure control device for use in a vehicle hydraulic brake system comprising: a housing having fluid inlet adapted to receive fluid from a source of fluid pressure, a fluid outlet through which fluid is adapted to be displaced to a brake cylinder, and a fluid chamber for providing communication between said inlet and said outlet; differential area means in said chamber sealingly engaging the walls thereof and providing fluid communication from said inlet to said outlet, said differential area means being adapted for movement in response to fluid pressure at said inlet to decrease the transmission of fluid pressure from said inlet to said outlet; resilient means for exerting a force on said differential area means for preventing movement of said differential area means and consequent decrease in the transmission of fluid pressure thereby below a first predetermined fluid pressure at said inlet and for yielding to allow movement of said differential area means to decrease the transmission of fluid pressure from said inlet to said outlet above said first predetermined fluid pressure at said inlet; a member in said fluid chamber separate from said differential area means being adapted for a predetermined movement in response to fluid pressure at said inlet for influencing the decrease in the transmission of fluid pressure from said inlet to said outlet; and resilient means for exerting a force on said member for providing said predetermined movement of said member which influences the transmission of fluid pressure from said inlet to said outlet above a second higher predetermined pressure at said inlet, a first valve portion between said inlet and said outlet; a second valve portion on said differential area means in said chamber engageable with said first valve portion to provide said interruption of said pressure transmission from said inlet to said outlet at said first predetermined pressure; said first valve portion being movable at said second predetermined fluid pressure at said inlet, movement of said first valve portion in response to decreasing fluid pressure at said inlet above said second prEdetermined fluid pressure providing a reduction in pressure at said outlet, said first valve portion being sealingly engageable with both said second valve portion and a fixed element in said housing.

Claim 9

A brake pressure control device according to claim 6 wherein said member is an annular member coaxially disposed with said differential area means in said chamber.

Claim 10

A brake pressure control device according to claim 7 wherein said member surrounds said differential area means in said chamber.

Claim 11

A brake pressure control device according to claim 6 wherein said predetermined movement of said member provides an additional passage for transmission of said fluid pressure from said inlet to said outlet.

Claim 12

A brake pressure control device according to claim 8 further including an additional passage for pressure transmission from said inlet to said outlet and wherein said predetermined movement of said member opens said additional passage.

Claim 13

A brake pressure control device according to claim 6 further including a valve member between said inlet and said outlet, and wherein said differential area means has a valve portion cooperating with said valve member to provide said interruption of fluid pressure transmission from said inlet to said outlet.

Claim 14

A brake pressure control device according to claim 6 wherein said differential area means in said chamber has a first total area exposed to fluid pressure at said inlet and a second total area exposed to fluid pressure at said outlet, the ratio of said first and second total areas being established so as to provide movement of said means in response to said fluid pressure at said inlet.

Claim 15

A brake pressure control device according to claim 12 wherein said second total area is greater than said first total area so that said differential area means moves toward said inlet in response to said fluid pressure at said fluid inlet.

Claim 16

A brake pressure control device according to claim 13 wherein said member is adapted for movement away from said inlet in response to a pressure drop across said member.