Pressure reducer device

Claim 2

In a pressure reducer device, for hydraulic brake systems in motor vehicles, comprising: a housing having a bore; pressure responsive valve means within said bore of said housing having a cylindrical portion having a closed bore and a land portion projecting radially from said cylindrical portion, said land portion sealingly engaging said bore of said housing to axially divide the same into a high pressure chamber and a low pressure chamber, said cylindrical portion having at least one valve port at that side thereof from said land portion which is exposed to said high pressure chamber and at least one opening at that side thereof from said land portion which is exposed to said low pressure chamber, said at least one valve port opening to said closed bore of said cylindrical portion, said at least one opening opening to said closed bore of said cylindrical portion; an end plug closing one end of said bore of said housing, said end plug having a blind bore sealingly and slidably receiving said that side of said cylindrical portion which is exposed to said high pressure chamber, said end plug having an integral sleeve disposed coaxially with and in alignment with said blind bore, said pressure responsive valve means having a first effective area exposed to said high pressure chamber pressure and a second effective area exposed to said low pressure chamber pressure after closure of said at least one valve port by said sleeve; and spring means biasing said pressure responsive valve means in a direction assisting said high pressure chamber pressure; the force applied to said pressure responsive valve means by pressure acting on said second effective area after the closure of said at least one valve port by said sleeve biasing said pressure responsive valve means to a closed position against the force of said spring means; the improvement comprising said sleeve slidably receiving that side of said cylindrical portion which is exposed to said high pressure chamber to open and close said at least one valve port to limit transmission of pressure from said high pressure chamber to said low pressure chamber through said at least one valve port, said closed bore of said cylindrical portion and said opening without the the presence of a seal.

Claim 3

A pressure reducer device as claimed in claim 1, in which said integral sleeve is formed with at least one valve port adapted to stay in lap position with said at least one valve port of said cylindrical portion.

Claim 4

A pressure reducer device as claimed in claim 1, in which said integral sleeve has an edge adapted to stay in lap position with said at least one valve port of said cylindrical portion.

Claim 5

A pressure reducer device, for hydraulic brake systems in motor vehicles, comprising: a housing having a bore; a pressure responsive valve element movable within said bore of said housing between one dead position and another dead position, said pressure responsive valve element having a cylindrical portion having a closed bore and a land portion projecting radially from said cylindrical portion, said land portion sealingly engaging said bore of said housing to axially divide the same into a high pressure chamber and a low pressure chamber, said cylindrical portion having a plurality of valve ports at the side thereof from said land portion which is exposed to said high pressure chamber and at least one opening at that opposite side thereof from said land portion which is exposed to said low pressure chamber, said plurality of valve ports opening to said closed bore of said cylindrical portion, said at least one opening opening to said closed bore of said cylindrical portion; an end plug closing one end of said bore of said housing, said end plug having a blind bore sealingly and slidably receiving said that side of said cylindrical portion which is exposed to said high pressure chamber, said end plug having an integral sleeve disposed coaxially with and in alignment with said blind bore, said sleeve slidably receiving that side of said cylindrical portion which is exposed to said high pressure chamber to close said plurality of valve ports of said cylindrical portion to close transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports, said closed bore of said cylindrical portion and said at least one opening, said integral sleeve having a plurality, corresponding in number to said plurality of valve ports of said cylindrical portion, of valve ports adapted to stay in lap position with said plurality of valve ports of said cylindrical portion, respectively, to open transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports of said cylindrical portion, said closed bore of said cylindrical portion and said at least one opening, said pressure responsive valve element having a first effective area exposed to said high pressure chamber and a second effective area exposed to said low pressure chamber pressure after closure of said plurality of valve ports of said cylindrical portion by said integral sleeve; and spring means biasing said pressure responsive valve element in a direction assisting said high pressure chamber pressure; the force applied to said pressure responsive valve element by pressure acting on said second effective area after the closure of said plurality of valve ports of said cylindrical portion by said sleeve biasing said pressure responsive valve element in a direction opposing the force of said spring means.

Claim 6

A pressure reducer device, for hydraulic brake systems in motor vehicles, comprising: a housing having a bore; a pressure responsive valve element movable within said bore of said housing between one dead position and another dead position, said pressure responsive valve element having a cylindrical portion having a closed bore and a land portion projecting radially from said cylindrical portion, said land portion sealingly engaging said bore of said housing to axially divide the same into a high pressure chamber and a low pressure chamber, said cylindrical portion having a plurality of valve ports at the side thereof from said land portion which is exposed to said high pressure chamber and at least one opening at that opposite side thereof from said land portion which is exposed to said low pressure chamber, said plurality of valve ports opening to said closed bore of said cylindrical portion, said at least one opening opening to said closed bore of said cylindrical portion; an end plug closing one end of said bore of said housing, said end plug having a blind bore sealingly and slidably receiving said that side of said cylindrical portion which is exposed to said high pressure chamber, said end plug having an integral sleeve disposed coaxially with and in alignment with said blind bore, said sleeve slidably receiving that side of said cylindrical portion which is exposed to said high pressure chamber to close said plurality of valve ports of said cylindrical portion to close transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports, said closed bore of said cylindrical portion and said at least one opening, said integral sleeve having a plurality, corresponding in number to said plurality of valve ports of said cylindrical portion, of valve ports adapted to stay in lap position with said plurality of valve ports of said cylindrical portion, respectively, to open transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports of said cylindrical portion, said closed bore of said cylindrical portion and said at least one opening, said pressure responsive valve element having a first effective area exposed to said high pressure chamber and a second effective area exposed to said low pressure chamber pressure after closure of said plurality of valve ports of said cylindrical portion by said integral sleeve; and spring means biasing said pressure responsive valve element in a direction assisting said high pressure chamber pressure; the force applied to said pressure responsive valve element by pressure acting on said second effective area after the closure of said plurality of valve ports of said cylindrical portion by said sleeve biasing said pressure responsive valve element in a direction opposing the force of said spring means.

Claim 7

In a dual hydraulic brake system having front and rear brake cylinders and a dual master cylinder for separately pressurizing said front and rear brake cylinders, a pressure reducer device comprising: a housing having a bore; a pressure responsive valve element movable within said bore of said housing, said pressure responsive valve element having a cylindrical portion having a closed bore and a land portion projecting radially from said cylindrical portion, said land portion sealingly engaging said bore of said housing to axially divide the same into a high pressure chamber communicating with rear system master cylinder pressure and into a low pressure chamber communicating with rear brake pressure, said cylindrical portion having a plurality of valve ports at that side thereof from said land portion which is exposed to said high pressure chamber and at least one opening at that opposite side thereof from said land portion which is exposed to said low pressure chamber, said plurality of valve ports opening to said closed bore of said cylindrical portion, said at least one opening opening to said closed bore of said cylinrical portion; an end plug closing one end of said bore of said housing, said end plug having a blind bore sealingly and slidably receiving said that side of said cylindrical portion which is exposed to said high pressure chamber, said end plug having an integral sleeve disposed coaxially with and in alignment with said blind bore, said sleeve slidably receiving that side of said cylindrical portion which is exposed to said high pressure chamber to close said plurality of valve ports of said cylindrical portion to close transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports, said closed bore of said cylindrical portion and said at least one opening, said integral sleeve having a plurality of valve ports corresponding in number to said plurality of valve ports of said cylindrical portion, adapted to stay in lap position with said plurality of valve ports of said cylindrical portion, respectively, to open transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports of said cylindrical portion, said closed bore of said cylindrical portion and said at least one opening, said plurality of valve ports of said integral sleeve and said plurality of valve ports of said cylindrical portion being shaped such that as said cylindrical portion moves from one dead position to another dead position, an opening area of each of said plurality of valve ports of said cylindrical portion varies substantially quadratically; said pressure responsive valve element having a first effective area exposed to the rear system master cylinder pressure, a second effective area exposed to the rear brake pressure after closure of said plurality of valve ports of said cylindrical portion and a third effective area exposed to front system brake pressure; and spring means biasing said pressure responsive valve element in a direction assisting the rear system master cylinder pressure; the force applied to said pressure responsive valve element by pressure acting on said second and third effective areas biasing said pressure responsive valve element in a direction opposing the bias of said spring means, said third effective area being sealed from said first and second effective areas whereby a failure in front brake pressure will substantially modify the functioning of said pressure responsive valve element.

Claim 8

In a dual hydraulic brake system having front and rear brake cylinders and a dual master cylinder for separately pressurizing said front and rear brake cylinders, a pressure reducer device comprising: a housing having a bore; a pressure responsive valve element movable within said bore of said housing, said pressure responsive valve element having a cylindrical portion having a closed bore and a land portion projecting radially from said cylindrical portion, said land portion sealingly engaging said bore of said housing to axially divide the same into a high pressure chamber communicating with rear system master cylinder pressure and into a low pressure chamber communicating with rear brake pressure, said cylindrical portion having a plurality of valve ports at that side thereof from said land portion which is exposed to said high pressure chamber and at least one opening at that opposite side thereof from said land portion which is exposed to said low pressure chamber, said plurality of valve ports opening to said closed bore of said cylindrical portion, said at least one opening opening to said closed bore of said cylinrical portion; an end plug closing one end of said bore of said housing, said end plug having a blind bore sealingly and slidably receiving said that side of said cylindrical portion which is exposed to said high pressure chamber, said end plug having an integral sleeve disposed coaxially with and in alignment with said blind bore, said sleeve slidably receiving that side of said cylindrical portion which is exposed to said high pressure chamber to close said plurality of valve ports of said cylindrical portion to close transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports, said closed bore of said cylindrical portion and said at least one opening, said integral sleeve having a plurality of valve ports corresponding in number to said plurality of valve ports of said cylindrical portion, adapted to stay in lap position with said plurality of valve ports of said cylindrical portion, respectively, to open transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports of said cylindrical portion, said closed bore of said cylindrical portion and said at least one opening, said plurality of valve ports of said integral sleeve and said plurality of valve ports of said cylindrical portion being shaped such that as said cylindrical portion moves from one dead position to another dead position, an opening area of each of said plurality of valve ports of said cylindrical portion varies substantially quadratically; said pressure responsive valve element having a first effective area exposed to the rear system master cylinder pressure, a second effective area exposed to the rear brake pressure after closure of said plurality of valve ports of said cylindrical portion and a third effective area exposed to front system brake pressure; and spring means biasing said pressure responsive valve element in a direction assisting the rear system master cylinder pressure; the force applied to said pressure responsive valve element by pressure acting on said second and third effective areas biasing said pressure responsive valve element in a direction opposing the bias of said spring means, said third effective area being sealed from said first and second effective areas whereby a failure in front brake pressure will substantially modify the functioning of said pressure responsive valve element.

Claim 9

In a dual hydraulic brake system having front and rear brake cylinders and a dual master cylinder for separately pressurizing said front and rear brake cylinders, a pressure reducer device comprising: a housing having a bore; a pressure responsive valve element movable within said bore of said housing, said pressure responsive valve element having a cylindrical portion having a closed bore and a land portion projecting radially from said cylindrical portion, said land portion sealingly engaging said bore of said housing to axially divide the same into a high pressure chamber communicating with rear system master cylinder pressure and into a low pressure chamber communicating with rear brake pressure, said cylindrical portion having a plurality of valve ports at that side thereof from said land portion which is exposed to said high pressure and at least one opening at that opposite side thereof from said land portion which is exposed to said low pressure chamber, said plurality of valve ports opening to said closed bore of said cylindrical portion, said at least one opening opening to said closed bore of said cylindrical portion; an end plug closing one end of said bore of said housing, said end plug having a blind bore sealingly and slidably receiving said that side of said cylindrical portion which is exposed to said high pressure chamber, said end plug having an integral sleeve disposed coaxially with and in alignment with said blind bore, said sleeve slidably receiving that side of said cylindrical portion which is exposed to said high pressure chamber to close said plurality of valve ports of said cylindrical portion to close transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports, said closed bore of said cylindrical portion and said at least one opening, said sleeve having an edge adapted to stay in lap position with said plurality of valve ports of said cylindrical portion to open transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports of said cylindrical portion, said closed bore of said cylindrical portion to said at least one opening, said pressure responsive valve element having a first effective area exposed to the rear system master cylinder pressure, a second effective area exposed to the rear brake pressure after closure of said plurality of valve ports of said cylindrical portion and a third effective area exposed to front system brake pressure; and spring means biasing said pressure responsive valve element in a direction assisting the rear system master cylinder pressure; the force applied to said pressure responsive valve element by pressure acting on said second and third effective areas biasing said pressure responsive valve element in a direction opposing the bias of said spring means, said third effective area being sealed from said first and second effective areas whereby a failure in front brake pressure will substantially modify the functioning of said pressure responsive valve element.

Claim 10

In a dual hydraulic brake system having front and rear brake cylinders and a dual master cylinder for separately pressurizing said front and rear brake cylinders, a pressure reducer device comprising: a housing having a bore; a pressure responsive valve element movable within said bore of said housing, said pressure responsive valve element having a cylindrical portion having a closed bore and a land portion projecting radially from said cylindrical portion, said land portion sealingly engaging said bore of said housing to axially divide the same into a high pressure chamber communicating with rear system master cylinder pressure and into a low pressure chamber communicating with rear brake pressure, said cylindrical portion having a plurality of valve ports at that side thereof from said land portion which is exposed to said high pressure and at least one opening at that opposite side thereof from said land portion which is exposed to said low pressure chamber, said plurality of valve ports opening to said closed bore of said cylindrical portion, said at least one opening opening to said closed bore of said cylindrical portion; an end plug closing one end of said bore of said housing, said end plug having a blind bore sealingly and slidably receiving said that side of said cylindrical portion which is exposed to said high pressure chamber, said end plug having an integral sleeve disposed coaxially with and in alignment with said blind bore, said sleeve slidably receiving that side of said cylindrical portion which is exposed to said high pressure chamber to close said plurality of valve ports of said cylindrical portion to close transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports, said closed bore of said cylindrical portion and said at least one opening, said sleeve having an edge adapted to stay in lap position with said plurality of valve ports of said cylindrical portion to open transmission of pressure from said high pressure chamber to said low pressure chamber through said plurality of valve ports of said cylindrical portion, said closed bore of said cylindrical portion to said at least one opening, said pressure responsive valve element having a first effective area exposed to the rear system master cylinder pressure, a second effective area exposed to the rear brake pressure after closure of said plurality of valve ports of said cylindrical portion and a third effective area exposed to front system brake pressure; and spring means biasing said pressure responsive valve element in a direction assisting the rear system master cylinder pressure; the force applied to said pressure responsive valve element by pressure acting on said second and third effective areas biasing said pressure responsive valve element in a direction opposing the bias of said spring means, said third effective area being sealed from said first and second effective areas whereby a failure in front brake pressure will substantially modify the functioning of said pressure responsive valve element.