Regulating valve

Claim 2

In a valve for maintaining the rate of flow of a fluid through a pipe substantially constant, said valve comprising: a valve body (1, 8, 11) having a fluid inlet port and a fluid outlet port, a hollow member (4) within said body between said ports defining a central chamber, a first duct (5) connecting said inlet port to said chamber, a second duct (16) connecting said outlet port to said chamber, and a valve member (9) movable in response to pressure changes within said chamber and cooperating with a valve seat (10) in said body to control said fluid flow, thrust-responsive means (22, 23, 24) positioned to receive the hydrodynamic thrust of fluid entering said valve-body through said inlet port, and connected to control the flow of fluid through said second duct in dependence on said thrust, thereby controlling the prpessure within said chamber and the position of said valve member, the improvement which comprises: a lever (20) pivotally connected to said thrust-responsive means and fixed to a pin (21) which can rotate about its own axis and projects from the valve body (1, 8, 11), a fork-shaped appendix (26) keyed on the pin (21), external to the valve body, a member (27) sliding between the arms of the fork shaped appendix under the action of a screw (28); a calibrating spring (29) inclined to the axis of the appendix which connects the sliding member (27) to the body (8), and a spring (37), biassing said appendix in the opposite direction from that in which it is biassed by the spring (29).

Claim 3

A valve as claimed in claim 1, in which the spring (37) biasses the appendix (26) through an intermediate transverse shaft (34) having a recess (33) which engages a projection (32) projecting from the appendix (26).

Claim 4

A valve as claimed in claim 2, in which the recess (33) is larger than the diameter of the appendix (32), to permit the free movement of the latter.

Claim 5

A valve as claimed in claim 1, in which the shaft (34) engages a pneumatic piston (36) which operates the shaft against the thrust of the spring (37).

Claim 6

Valve as claimed in claim 1, comprising a piston chamber, a fluid pressure responsive piston in said chamber, and a lost motion connection between said piston and lever whereby movement of said piston relative to said lever beyond a predetermined limit will swing said lever to actuate said valve.

Claim 7

Valve as claimed in claim 5, comprising additional spring means resiliently biassing said piston to a position in which it permits closing of said valve.

Claim 8

Valve as claimed in claim 6, comprising an auxiliary piston aligned with said first mentioned piston in said piston chamber at the opposite end of said first-mentioned piston from said additional spring means, and fluid ports in said valve chamber permitting the successive actuation of said pistons.

Claim 9

In a valve for maintaining the rate of flow of a fluid through a pipe substantially constant, said valve comprising: a valve body (1, 8, 11) having a fluid inlet port and a fluid outlet port, a hollow member (4) within said body between said ports defining a central chamber, a first duct (5) connecting said inlet port to said chamber, a second duct (16) connecting said outlet port to said chamber, and a valve member (9) movable in response to pressure changes within said chamber and cooperating with a valve seat (10) in said body to control said fluid flow, thrust-responsive means (22, 23, 24) positioned to receive the hydrodynamic thrust of fluid entering said valve-body through said inlet port, and connected to control the flow of fluid through said second duct in dependence on said thrust, thereby controlling the pressure within said chamber and the position of said valve member, the improvement which comprises: a lever (20) pivotally connected intermediate its end to said valve body for swinging movement through a median position between two extreme positions, one end of said lever being pivotally connected to said thrust-responsive means, spring means (29) connected between said body and the other end of said lever and biassing said lever to swing in a direction opposite to that in which said lever is urged by said thrust-responsive means, the total force exerted by said spring means being proportional to the degree of extension of said spring means, which lies at an acute angle to said lever such that pivotal movement of said lever increases the component of said total force which is effective to resist the force applied by said thrust-responsive means as said total force decreases, and decreases said component as said total force increases.

Claim 10

In a valve for maintaining the rate of flow of a fluid through a pipe substantially constant, said valve comprising: a valve body (1, 8, 11) having a fluid inlet port and a fluid outlet port, a hollow member (4) within said body between said ports defining a central chamber, a first duct (5) connecting said inlet port to said chamber, a second duct (16) connecting said outlet port to said chamber, and a valve member (9) movable in response to pressure changes within said chamber and cooperating with a valve seat (10) in said body to control said fluid flow, thrust-responsive means (22, 23, 24) positioned to receive the hydrodynamic thrust of fluid entering said valve-body through said inlet port, and connected to control the flow of fluid through said second duct in dependence on said thrust, thereby controlling the pressure within said chamber and the position of said valve member, the improvement which comprises: a lever (20) pivotally connected intermediate its end to said valve body for swinging movement through a median position between two extreme positions, one end of said lever being pivotally connected to said thrust-responsive means, spring means (29) connected between said body and the other end of said lever and biassing said lever to swing in a direction opposite to that in which said lever is urged by said thrust-responsive means, the total force exerted by said spring means being proportional to the degree of extension of said spring means, which lies at an acute angle to said lever such that pivotal movement of said lever increases the component of said total force which is effective to resist the force applied by said thrust-responsive means as said total force decreases, and decreases said component as said total force increases.

Claim 11

Valve as claimed in claim 8, in which said body is equipped with a plurality of means for attaching said spring thereto, located at varying distances from the median position occupied by said lever.

Claim 12

Valve as claimed in claim 8, in which said increase in the effective component of said total force is directly proportional to the decrease in said total force and said decrease in said component is directly proportional to the increase in said total force.

Claim 13

Valve as claimed in claim 8, comprising means carried by said other end of said lever for adjusting the point at which said lever is connected to said spring longitudinally of said lever.