US4738279A — Multiway valves with load feedback

Claim 1

Independent Claim 277 words

Multiway acting valve for a load sensing-regulated drive system with a housing with a longitudinal bore, a first annular groove intermediate the ends of said bore adapted to be connected to a pump, a pair of second grooves in said bore on opposite sides of said first groove and adapted to be connected with a consumer to be controlled, a pair of third annular grooves on opposite sides of said second grooves and adapted to be connected with a drain line, a pair of fourth annular grooves on opposite sides of said third grooves and adapted to be connected with a control pressure signal line, a valve piston having a longitudinal hole located on at least one side movable in said bore, spaced transverse holes in the valve piston communicating with said longitudinal hole and through which a connection between the first annular groove connected with the pump and one of the pair of second annular grooves connected with the consumer and one of the pair of third annular grooves connected with the drain and through which a connection between one of the pairs of second annular grooves connected with the consumer and one of the fourth annular grooves connected with the control pressure signal line is produced on movement of the valve piston in the bore characterized in that a pressure-reducing element that reduces the pressure conveyed to the connection with the control pressure signal line and which is controlled as a function of the displacement path of the valve piston is located in the connection produced by the annular grooves connected with the consumer with the annular grooves connected with the control pressure signal line.

Claim 2

Dependent Claim 277 words

Multiway acting valve for a load sensing-regulated drive system with a housing with a longitudinal bore, a first annular groove intermediate the ends of said bore adapted to be connected to a pump, a pair of second grooves in said bore on opposite sides of said first groove and adapted to be connected with a consumer to be controlled, a pair of third annular grooves on opposite sides of said second grooves and adapted to be connected with a drain line, a pair of fourth annular grooves on opposite sides of said third grooves and adapted to be connected with a control pressure signal line, a valve piston having a longitudinal hole located on at least one side movable in said bore, spaced transverse holes in the valve piston communicating with said longitudinal hole and through which a connection between the first annular groove connected with the pump and one of the pair of second annular grooves connected with the consumer and one of the pair of third annular grooves connected with the drain and through which a connection between one of the pairs of second annular grooves connected with the consumer and one of the fourth annular grooves connected with the control pressure signal line is produced on movement of the valve piston in the bore characterized in that a pressure-reducing element that reduces the pressure conveyed to the connection with the control pressure signal line and which is controlled as a function of the displacement path of the valve piston is located in the connection produced by the annular grooves connected with the consumer with the annular grooves connected with the control pressure signal line.

Claim 3

Dependent Claim 29 words

Multiway valve according to claim 1, in which the connection between the annular grooves is controlled by an auxiliary piston slidable in the longitudinal hole in the valve piston.

Claim 4

Dependent Claim 117 words

A multiway valve as claimed in claim 2 wherein, in an operative position of the valve piston, a connection is provided between the first groove and one of the pair of second grooves and between one of the pair of third grooves and one of the pair of fourth grooves by means of a longitudinal hole in the auxiliary piston, a fixed restrictor in said longitudinal hole between the first groove and said one of the pair of second grooves and a variable restrictor between said one of the pair of third grooves and said one of the fourth grooves, said variable restrictor restricting flow of fluid as a function of the displacement of the valve piston.

Claim 5

Dependent Claim 73 words

Multiway valve according to claim 3, characterized in that a transverse hole is provided in the auxiliary piston, said hole being continuously connected with a transverse hole in the valve piston, which in the operative state produces a conection between said pump and consumer, and to which the longitudinal hole of the auxiliary piston is connected, in which case at least one part of this longitudinal hole is designed as the fixed restrictor.

Claim 6

Dependent Claim 85 words

Multiway valve according to claim 4, characterized in that a second transverse hole connecting to the longitudinal hole in the auxiliary piston is connected with an annular groove in said auxiliary piston, which is connected with at least one transverse hole in the valve piston, in which case the mouth of this transverse hole located in the valve piston is capable of being more or less covered by the wall of the bore in the housing depending on the displacement position of the valve piston.

Claim 7

Dependent Claim 27 words

A multiway valve as claimed in claims 1 or 2 or 3 or 4 or 5 wherein the valve piston has a longitudinal hole in each end.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1991-04-19	1991-10-19	1992-04-19	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1995-04-19	1995-10-19	1996-04-19	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1999-04-19	1999-10-19	2000-04-19	$7700.00	Window Closed / Lapsed

Multiway valves with load feedback

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