GB1568431A - Time controlled valve - Google Patents

Description

(54) A TIME CONTROLLED VALVE (71) We, AMERACE CORPORA TION a Corporation organized and existing under the laws of the State of Delaware, United States of America, of 245 Park Avenue, New York, State of New York, United States of America, do hereby de clare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the follow ing statement: The present invention relates generally to valves and pertains, more specifically, to time controlled valves of the type in which a fluid circuit is opened or closed after the lapse of a predetermined time interval following actuation of the valves by a relay of some like actuating apparatus.

A variety of time-delay control apparatus is currently available in which a timing device is operated by an actuator to provide a timed interval between actuation of the timing device and the occurrence of some desired event, such as the operation of an electric switch. Among the most widely accepted of such control apparatus are those which employ a pneumatic timing device together with a solenoid actuator so that the timed interval can be measured either from activation or deactivation of the solenoid.

In certain environments, such as in the control of the flow of flammable fluids, and especially combustible gases, time-delay control apparatus is employed to open or close flow control valves. For example, fluid circuits for pilot flames in gas-burning sys tems are controlled by time-delay apparatus so that the fluid circuits are opened or - closed after a time-delay interval measured from the occurrence of a given event, such as an interruption in gas flow. In such environments, the employment of electrical devices may present a hazard and it would be advantageous to have available a time delay device which does not rely upon electrical components for its operation.

Pneumatic timing mechanisms which provide accurately measured intervals for timedelay purposes without the use of electrical components are especially well-suited for use in environments where electrical components are unnecessary, undesirable or dangerous. The utilization of such pneumatic timing mechanisms for the control of fluids requires a reliable valve which is easily operated by a pneumatic timing mechanism to provide positive actuation between open and closed positions with no deleterious effect upon the functioning of the timing mechanism.

According to the present invention there is provided a time controlled valve incorporating a housing defining separate first and second chambers, a spindle longitudinally displaceable within said first chamber, a timing unit coupled to said spindle to control longitudinal movement thereof, a fluid valve located within said second chamber and incorporating a valve seat and a cooperating movable valve member, a snap action switch located in said first chamber and coupled to said spindle, a pivotally movable lever extending through an opening in a wall separating said first and second chambers and coupling the snap action switch with the movable valve member, and a fluid tight sealing element sealing said opening and acting as a pivot for said lever, the arrangment being such that upon longitudinal movement of the spindle under the control of the timing unit the snap action switch is triggered after a predetermined time controlled interval whereupon said valve member is snapped from or to a sealed position with the cooperating valve seat.

The invention will be more fully understood, while still further objects and advantages will become apparent, by reference to the following detailed description of an embodiment of the invention illustrated in the accompanying drawings, in which: Figure I is an elevational view of a time controlled valve constructed in accordance with the invention, with portions broken away to reveal operating component parts thereof and a diagrammatic illustration of the environment in which the valve is installed; Figure 2 is an elevational view similar to Figure 1, but with the component parts in a different operating position; Figure 3 is an elevational view similar to Figures 1 and 2 but with the component parts in a still different operating position; Figure 4 is a fragmentary cross-sectional view taken along line 4-4 of Figure 1;; Figure 5 is an enlarged fragmentary crosssectional view of a portion of the time controlled valve as shown in Figures 1 to 3; Figure 6 is a further enlarged fragmentary cross-sectional view of a portion of the valve as shown in Figure 5; Figure 7 is a fragmentary cross-sectional view of a portion of the valve with certain component parts re-arranged for an alternate operating mode; Figure 8 is an elevational view of a time controlled valve constructed in accordance with the invention, with portions broken away to reveal operating component parts thereof and a diagrammatic illustration of the environment in which the valve is installed; Figure 9 is an elevational view similar to Figure 8, but with the component parts in a different operating position; Figure 10 is a fragmentary cross-sectional view taken along line 10-10 of Figure 8;; Figure 11 is a fragmentary cross-sectional view of a portion of the valve with certain component parts re-arranged for an alternate operating mode; Figure 12 is a fragmentary cross-sectional view of a portion of an alternate time controlled valve constructed in accordance with the invention; Figure 13 is a fragmentary cross-sectional view similar to Figure 12, but with the component parts in another operating position; and Figure 14 is a perspective view of a component part of the valve of Figure 12.

Referring now to the drawings, and especially to Figure 1 thereof, a time controlled valve constructed in accordance with the invention is illustrated at 10. The valve 10 has a frame 12 extending longitudinally between an upper end 14 and a lower end 16 of the valve.

Actuator means is shown in the form of a fluid actuator 20 at the lower end 16 of the valve 10. Actuator 20 includes a piston 22 placed in a cylinder 24 for reciprocating movement in longitudinally upward and downward directions. Piston 22 is biased downwardly by a helical spring 26 which extends between the piston and a gland 28 which closes the cylinder 24 at the uppermost end thereof. An actuator rod 30 is affixed to the piston 22 and extends longitudinally upwardly through the gland 28, the actuator rod 30 being movable relative to the gland with movement of the piston. An inlet port 32 is provided for admitting a working fluid to the cylinder 24 below the piston 22 so as to urge the piston upwardly against the bias of spring 26. An alternate port 34 serves as a vent port and vents the cylinder above the piston to permit upward movement of the piston.

In the configuration illustrated in Figures 1 to 3, the time controlled valve 10 is to operate a fluid valve to either open or close a fluid circuit after the lapse of a predetermined interval of time following activation of actuator 20 to move piston 22 from the lower or rest position seen in Figure 1 to the upper or activated position seen in Figures 2 and 3.

The fluid valve is shown at 40 and may be connected into a fluid circuit 42 through a common leg 44, illustrated as an input leg, and either one or both of alternate legs 46 and 48, illustrated as output legs, of the fluid circuit. Input leg 44 is thus connected to valve 40 at a first passage 50, which, in this instance, constitutes an inlet passage, while output legs 46 and 48 can be connected at alternate second passages 52 and 54, which, in this instance, would constitute outlet passages, in the valve body 56. Valve body 56 includes a valve chamber, shown in the form of a longitudinally extending cylindrical bore 58, and the passages 50, 52 and 54 communicate with the bore 58. A valve seat 60 is affixed within valve body 56 at each end of the bore 58, preferably by means of threaded connections at 62.Each valve seat 60 includes an annular groove 64 communicating with a respective second passage 52 or 54 and an internal conduit 66 extending between annular groove 64 and a seating portion in the form of seating end 68 of the valve seat 60.

A shuttle 70 is placed in the bore 58 and has an external configuration, portions of which are complementary to the bore to enable the shuttle to slide upwardly and downwardly within the bore. The shuttle 70 carries a sealing member in the form of a ball 72 of elastomeric material at each end of the shuttle, each ball 72 being in such axial alignment with each conduit 66 at seating end 68 of each valve seat 60 so that a ball 72 is seated against one or the other of the seats 60 to close the respective conduit 66. In the lower positon of the shuttle, as seen in Figures 1 and 2, the lower ball 72 is seated against the lower valve seat 60 to close the conduit 66 therein, and thereby close communication between second passage 54 and the chamber provided by bore 58.At the same time, communication between first passage 50 and second passage 52 remains open, via conduit 66 in the upper valve seat 60, bore 58 and longitudinal channels 73 in the external surface of shuttle 70 (also see Figure 4).

The valve 10 employs a time-delay mechanism, shown in the form of a pneumatic timing mechanism 74 at the upper end of device 10. Timing mechanism 74 is of a type now well-known in the art. A very similar pneumatic timing mechanism is described in United States Patent No. 3,599,131, issued on August 10, 1971, to Flanagan et al. A motion transmitting member in the form of a spindle 76 extends downwardly from timing mechanism 74 and it is the function of the timing mechanism to move spindle 76 from a lowermost location, as seen in Figure 1, to an uppermost location, as seen in Figure 3, at a timed rate of movement so that the elapsed time during such movement of spindle 76 corresponds to a selected time-delay interval. The duration of the interval is selected by setting a dial 78 at the top of the timing mechanism 74.

As clearly shown in Figure 1 the spindle 76 is displaceable with a sealed chamber and passes through a bushing 80 and is affixed at Its upper end to a collar 82, which is a part of the timing mechanism 74. a helical spring 84 biases the collar 82 and spindle 76 upwardly.

The pneumatic arrangement in timing mechanism 74 enables upward movement of collar 82 and, therefore, spindle 76 from the lowermost location at a selected rate while permitting downward movement to the lowermost location, against the bias of spring 84, at an unrestricted rate. At its lower end, spindle 76 is coupled to actuator rod 30 by means of a yoke arrangement which includes a pin 86 affixed to the spindle 76 and passing through a pair of opposed longitudinal slots 88 in a sleeve-like portion 90 of the actuator rod 30. In the position of the parts illustrated in Figure 1, the downward biasing force of spring 26 upon piston 22 maintains the piston and actuator rod 30 in the downward position and holds spindle 76 in the lowermost location, against the upward bias of spring 84, by virtue of the engagement of pins 86 with the uppermost ends of slots 88.

Upon activation of the time controlled valve 10, as seen in Figure 2, fluid (in this instance air) is introduced into cylinder 24 of actuator 20 through inlet port 32 under pressure so as to raise piston 22 against the bias of spring 26 and thereby actuate rod 30 to move the rod to an uppermost position, as illustrated in Figure 2. Such upward movement of rod 30 takes place almost instantaneously and frees the spindle 76 for upward movement, in response to the upward bias of spring 84, at a predetermined rate, the pin 86 now being able to move upwardly within slots 88 in rod 30.

As best seen in Figures 4 and 5, as well as in Figures 1 to 3, as spindle 76 moves upwardly a trip means shown in the form of an arm 92 carried by the spindle 76 and projecting laterally therefrom, also moves upwardly at the same rate of movement. A first, or lower bearing edge 93 on arm 92 preferably has a knife-edge configuration and engages a U-shaped toggle lever 94 to swing the toggle lever in a clockwise direction, as viewed in Figure 5, about knife-edge pivots provided at 96 by pivot blocks 98 affixed to extremities 100 of the toggle lever 94 and seated in V-shaped bearing blocks 102, carried by a plate 104 affixed to the frame 12 of the valve 10.Toggle lever 94 is coupled to a valve-operating lever 106 by means of an over-center or snap-action toggle spring 108 which has a U-shaped configuration and includes a pair of opposed legs 110, one of which legs 110 engages the toggle lever 94 and the other one of which legs 110 engages the valve-operating lever 106. Valve-operating lever 106 extends through the wall of the valve body 56 and terminates within the valve 40 at a bifurcated end 112 which engages shuttle 70 within an annular recess 114 in the shuttle.

Lever 106 is held in place by a support block 116 of elastomeric material which surrounds intermediate portion 118 of lever 106 and is seated in a cavity 120 within the wall of the valve body 56. The resilient, flexible nature of the material of block 116 allows lever 106 to swing about an axis perpendicular to the plane of the paper, as viewed in Figures 1 to 3 and 5, while intimate contact between the material of block 116 and portion 118 of lever 106 serves as a seal which seals the valve body against leakage along the lever 106 between the valve chamber provided by bore 58 and the exterior of the valve. Block 116 is retained within cavity 120 by plate 104 and preferably is placed under compression within the cavity so as to assure intimate sealing contact between the block 116 and portion 118 of lever 106.In order to simplify construction, as well as to assure proper sealing and effective operation, block 116 may be molded around portion 118 to fabricate an integral lever 106 and block 116 assembly.

Continued upward movement of spindle 76 and concomitant upward movement of arm 92 will swing toggle lever 94 and toggle spring 108 to a dead-center position relative to the valve operating lever 106, which is held stationary by the support block 116, as seen in Figure 2. As soon as toggle lever 94 moves beyond the dead-center position, toggle spring 108 will swing valve-operating lever 106 in a counterclockwise direction, as viewed in Figure 3, with a relatively quick, snap-action to immediately move shuttle 70 from the first or lowermost position, seen in Figure 1, to the second or uppermost position, seen in Figure 3.Such movement of the shuttle will seat the upper ball 72 against the seating end 68 of the upper valve seat 60 to close the conduit 66 therein, and thereby close communication between second passage 42 and the chamber provided by bore 58, thus closing off communication between first passage 50 and second passage 52. At the same time, communication between first passage 50 and second passage 52 is opened. In this manner, valve 40 operates to switch the fluid circuit 42 to change the communication between common leg 44 of the circuit and the alternate legs 46 and 48. Because valve seats 60 are threaded into valve body 56, the valve seats may be adjusted longitudinally to position seating ends 68 relative to shuttle 70 for optimum performance.Thus, the toggle lever 94, valve-operating lever 106 and toggle spring 108, together with the knifeedge bearing means provided by the knifeedge pivots at 96 and support block 116, provide a snap-action mechanism for moving the shuttle 70 to actuate valve 40 rapidly in response to the relatively slower movement of spindle 76 at the expiration of a predetermined timed interval following activation of time controlled valve 10.

Upon deactivation of time controlled valve 10, the working fluid in cylinder 24 is released to permit the piston 22 to move downwardly, under the biasing force of spring 26, thereby moving actuator rod 30 downwardly until the yoke provided by slots 88 in portion 90 of rod 30 engage pin 86 in spindle 76 and pull spindle 76 downwardly until the component parts return to the initial position illustrated in Figure 1. Since the timing mechanism 74 does not impede downward movement of spindle 74, such movement can occur rapidly.The rapid downward movement of spindle 74 brings arm 92 rapidly downward so that a second, or upper knife-edge bearing edge 122 on the arm engages the toggle lever 94 to swing the lever counterclockwise, as viewed in Figures 1 to 3 and 5, back through the dead-center positon, and operate the toggle spring 108 and valve-operating lever 106 so as to quickly return the shuttle 70 back to the lower position.

In order to facilitate operation of valve 40 in the snap-action fashion described above, several features have been provided in the arrangement of toggle lever 94. valveoperating lever 106, and toggle spring 108.

The U-shaped configuration of toggle lever 94 provides a relatively long lever arm between the knife-edge pivots at 96 and the bearing edges 93 and 122 of the arm 92 carried by spindle 76, while enabling a compact arrangement which allows for a relatively long valve-operating lever 106. In addition, as best seen in Figures 4 to 6, toggle spring 108 is provided with arcuate bearing surfaces 124 which engage the toggle lever 94 and the valve-operating lever 106 at the sides of the tabs 126 and 128 which are integral with toggle lever 94 and valve-operating lever 106, respectively, and which pass through the toggle spring to secure the toggle spring in place.These arcuate bearing surfaces 124 assure that the toggle spring 106 is in rolling contact with the levers 94 and 106 during the swinging movements, as seen in the various positions illustrated in phantom in Figure 5, to further reduce frictional forces in the snap-action mechanism. Further, as best seen in Figure 6, toggle spring 108 is provided with opposed knife-edge bearing edges 130 engaging tab 126 of toggle lever 14 and opposed knife-edge bearing edges 132 engaging tab 128 of valve-operating lever 106.

The combination of the long lever arms, together with the low-friction pivots provided by knife-edge pivots at 96, the knifeedge bearing edges 93, 122, 130 and 132 and the resilient nature of support block 116, and the rolling engagement of the toggle spring, reduces to a minimum the force which must be exerted by the moving spindle 76 to operate the valve 40. Thus, the timing mechanism 74 can operate effectively to provide an accurately measured timedelay interval.

Turning now to Figure 7, where it is desired to actuate valve 40 upon the expiration of an interval of time measured from the deactivation of valve 10, rather than from activation of the valve 10 as described above, the location of spring 26 is changed from between the piston 22 and gland 28 to below the piston 22, as illustrated in Figure 7. In this manner, spring 26 exerts an upwardly directed biasing force upon the piston 22. However, upward movement of the piston 22 in response to the biasing force of spring 26 is resisted by the presence of a working fluid introduced into cylinder 24 above the piston 22, via the alternate port 34. Thus, as long as the valve 10 remains activated; that is, as long as working fluid under pressure is maintained in the cylinder 24 above the piston 22, the timing mechanism 74. spindle 76 and valve 40 will remain in the positions illustrated in Figure 1.

Upon deactivation of time controlled valve 10; that is, upon release of the working fluid from the cylinder 24 above the piston 22, spring 26 will immediately move piston 22 to the uppermost position of the piston, releasing the spindle 76 and enabling the timing mechanism 74 to operate so as to move spindle 76 upwardly toward the uppermost location thereof and actuate valve 40, all as described hereinabove. Hence, valve 40 will be actuated following the expiration of a predetermined timed interval measured from deactivation of the valve 10.

It is noted that the illustrated embodiment employs a fluid-operated timing mechanism to actuate a fluid valve in response to activation or deactivation of a fluid actuator. Since all of the components are operated by fluid, or handle a fluid, no electrical devices are required. Thus, the time controlled valve 10 is well-suited to installations where electrical components would introduce a hazard. Moreover, since the interior of valve 40 is completely isolated from the interior of the timing mechanism 74, and the interior of fluid actuator 20 is likewise isolated, there will be no contamination of one fluid by another.

Therefore, valve 40 can be employed to handle corrosive, flammable or otherwise dangerous fluids which would not contaminate the fluid which operates the device or the timing mechanism and which may be exhausted to the surrounding areas. Of course, where no hazard would exist, fluid actuator 20 could be replaced with an electrical actuator such as a solenoid.

Figure 8 also shows an embodiment of the invention illustrated at 10. The time controlled valve 10 has a frame 12 extending longitudinally between an upper end 14 and a lower end 16 of the valve.

Actuator means is shown in the form of a fluid actuator 20 at the lower end 16 of the time controlled valve 10. Actuator 20 includes a piston 22 placed in a cylinder 24 for reciprocating movement in longitudinally upward and downward directions. Piston 22 is biased downwardly by a helical spring 26 which extends between the piston and a gland 28 which closes the cylinder 24 at the uppermost end thereof. An actuator rod 30 is affixed to the piston 22 and extends longitudinally upwardly through the gland 28, the actuator rod 30 being movable relative to the gland movement of the piston. An inlet port 32 is provided for admitting a working fluid to the cylinder 24 below the piston 22 so as to urge the piston upwardly against the bias of spring 26. An alternate port 34 serves as a vent port and vents the cylinder above the piston to permit upward movement of the piston.

In the configuration illustrated in Figures 8 and 9, the time controlled valve 10 is to operate a fluid valve to either close or open a fluid circuit after the lapse of a predetermined interval of time following activation of actuator 20 to move piston 22 from the lower or rest position seen in Figure 8 to the upper or activated position seen in Figure 19.

The fluid valve is shown at 40 and may be connected into a fluid circuit 42 through a common leg 44, illustrated as an input leg, and either one or both of alternate legs 46 and 48, illustrated as output legs, of the fluid circuit. Input leg 44 is thus connected to valve 40 at a first passage 50, which, in this instance, constitutes an inlet passage, while output legs 46 and 48 can be connected at alternate second passages 52 and 54, which, in this instance, would constitute outlet passages, in the valve body 56. Valve body 56 includes a valve chamber, shown in the form of a longitudinally extending cylindrical bore 58, and the passages 50, 52 and 54 communicate with the bore 58. A valve seat 60 is affixed within valve body 56 at each end of the bore 58, preferably by means of threaded connections at 62.Each valve seat 60 includes an annular groove 64 communicating with a respective second passage 52 or 54 and an internal conduit 66 extending between annular groove 64 and a seating portion in the form of seating end 68 of the valve seat 60.

A valve element in the form of a shuttle 70 is placed in the bore 58 and has an external configuration, portions of which are complementary to the bore to enable the shuttle to slide downwardly and upwardly within the bore. The shuttle 70 carries a sealing member in the form of a ball 72 of elastomeric material at each end of the shuttle, each ball 72 being in such axial alignment with each conduit 66 at seating end 68 of each valve seat 60 so that a ball 72 is seated against one or the other of the seats 60 to close the respective conduit 66. In the upper position of the shuttle, as seen in Figure 8, the upper ball 72 is seated against the upper valve seat 60 to close the conduit 66 therein, and thereby close communication between second passage 54 and the chamber provided by bore 58.At the same time, communication between first passage 50 and second passage 52 remains open, via conduit 66 in the lower valve seat 60, bore 58 and longitudinal channels 73 in the external surface of shuttle 70 (also see Figure 10).

The time controlled valve 10 employs a time-delay mechanism, shown in the form of a pneumatic timing mechanism 74 at the upper end of the valve 10. Timing mechanism 74 is of a type now well known in the art. A very similar pneumatic timing mechanism is described in United States Patent No. 3,599,131, issued on August 1, 1971, to Flanagan et al. A motion transmitting member in the form of a spindle 76 extends downwardly from timing mechanism 74 and it is the function of the timing mechanism to move spindle 76 from a lowermost location, as seen in Figure 8, to an uppermost location, as seen in Figure 9, at a timed rate of movement so that the elapsed time during such movement of spindle 76 corresponds to a selected timedelay interval. The duration of the interval is selected by setting a dial 78 at the top of the timing mechanism 74.

Spindle 76 passes through a bushing 80 and is affixed at its upper end to a collar 82, which is a part of the timing mechanism 74.

A helical spring 84 biases the collar 82 and spindle 76 upwardly. The pneumatic arrangement in timing mechanism 74 enables upward movement of collar 82 and, therefore, spindle 76 from the lowermost location at a selected rate while permitting downward movement to the lowermost location, against the bias of spring 84, at an unrestricted rate. At its lower end, spindle 76 is coupled to actuator rod 30 by means of a yoke arrangement which includes a pin 86 affixed to the spindle 76 and passing through a pair of opposed longitudinal slots 88 in a sleeve-like portion 90 of the actuator rod 30.

In the position of the parts illustrated in Figure 8, the downward biasing force of spring 26 upon piston 22 maintains the piston and actuator rod 30 in the downward position and holds spindle 76 in the lowermost location, against the upward bias of spring 84, by virtue of the engagement of pin 86 with the uppermost ends of slots 88.

Upon activation of the time controlled valve 10, fluid (in this instance air) is introduced into cylinder 24 of actuator 20 through inlet port 32 under pressure so as to raise piston 22 against the bias of spring 26 and thereby actuate rod 30 to move the rod to a uppermost position, as illustrated in Figure 9. Such upward movement of rod 30 takes place almost instantaneously and frees the spindle 76 for upward movement, in response to the upward bias of spring 84, at a predetermined rate, the pin 86 now being able to move upwardly within slots 88 in rod 30.

As best seen in Figure 10, as well as in Figures 8 and 9, a U-shaped trip arm 92 is affixed to spindle 76 by means of a clamp 94 and is thereby carried by the spindle 76 for upward movement with the spindle at the same rate of movement. A drive member in the form of a bearing pin 96 is carried by the trip arm 92, at the other end thereof, and moves upwardly with the trip arm 92 and the spindle 76.

Bearing pin 96 is engaged with a latch 98 at a drive surface 100 of the latch 98. Latch 98 is journaled upon a shaft 102 which extends between a pair of mounting brackets 104 secured to frame 12 so that latch 98 can pivot about the axis of the shaft 102, which axis is perpendicular to the direction of movement of spindle 76.

Latch 98 is biased in a counterclockwise direction (as viewed in Figures 8 and 9) by resilient biasing means in the form of a helical spring 106 extending between the lower end of the latch and the frame 12 to urge a latching shoulder 108 into latching engagement with a valve-operating lever 110. Valve-operating lever 110 extends through the wall of the valve body 56 and terminates within the valve 40 at a bifuricated end 112 which engages shuttle 70 within an annular recess 114 in the shuttle.

Lever 110 is held in place by a support block 116 of elastomeric material which surrounds intermediate portion 118 of lever 110 and is seated in a cavity 120 within the wall of the valve body 56. The resilient, flexible nature of the material of block 116 allows lever 110 to swing about an axis perpendicular to the plane of the paper, as viewed in Figures 8 and 9, while intimate contact between the material of block 116 and portion 118 of lever 110 serves as a seal which seals the valve body against leakage along the lever 110 between the valve chamber provided by bore 58 and the exterior of the valve. Block 116 is retained within cavity 120 by a plate 122 and preferably is placed under compression within the cavity so as to assure intimate sealing contact between the block 116 and portion 118 of lever 110.In order to simplify construction, as well as to assure proper sealing and effective operation, block 116 may be molded around portion 118 to fabricate an integral lever 110 and block 116 assembly.

Valve-operating lever 110 is biased upwardly, in a clockwise direction as viewed in Figures 8 and 9, by resilient biasing means in the form of a helical valve spring 124. Valve spring 124 has a lower end secured to valve-operating lever 110 at 126 and an upper end secured to frame 12 at 128. When the spindle 76 is at the location shown in Figure 8, latch 98 is in a first position wherein latching shoulder 108 engages valve-operating lever 110 and retains lever 110 in its first position. During initial upward movement of spindle 76 from the location shown in Figure 8 toward the location shown in Figure 9, latch 98 will retain valve-operating lever 110 in its first position.

Continued upward movement of spindle 76 and concomitant upward movement of trip arm 92 will cause bearing pin 96 to drive latch 98 clockwise about shaft 102, thereby releasing the engagement between latching shoulder 108 and valve-operating lever 110.

As soon as valve-operating lever 110 is released from latch 98, the positive biasing force of valve spring 124 will very quickly swing valve-operating lever 110 in a clockwise direction to immediately move shuttle 70 from the first or uppermost position, seen in Figure 8, to the second or lowermost position, seen in Figure 9. Such movement of the shuttle will seat the lower ball 72 against the seating end 68 of the lower valve seat 60 to close the conduit 66 therein, and thereby close communication between second passage 52 and the chamber provided by bore 58, thus closing off communication between first passage 50 and second passage 52. At the same time, communication between first passage 50 and second passage 54 is opened.In this manner, valve 40 operates to switch the fluid circuit 42 to change the communication between common leg 44 of the circuit and the alternate legs 46 and 48. Since the positive biasing force of valve spring 124 is transmitted directly to lower ball 72, through valveoperating lever 110 and shuttle 70, the biasing force directly exerts a valve sealing force tending to enhance the seal between lower ball 72 and corresponding lower valve seat 60. Thus, the tripping mechanism provided by trip arm 92, bearing pin 96, latch 98, and the associated component parts described above, enables valve spring 124 to provide a snap-action actuation of valve 40 together with a relatively strong positive valve sealing force, while still enabling tripping to take place in response to the relatively light forces exerted by the relatively slow upward movement of spindle 76.

The relative location of the bearing pin 96, the pivot provided by shaft 102 and the latch biasing spring 106, together with the relatively light biasing force supplied by spring 106, assures that accurate movement of spindle 76, in response to timing mechanism 74, is not impeded.

In order to assure that valve 40 is actuated precisely at the expiration of a predetermined timed interval following activation of the time controlled valve 10, the location of bearing pin 96 is adjustable upwardly and downwardly relative to trip arm 92 and the spindle 76. Thus, bearing pin 96 is carried by a carriage 130 having a threaded aperture 132 engaged by a lead screw 134 secured in a bracket 136 on the trip arm 92. Rotation of lead screw 134, by engagement of an appropriate driving tool (not shown) in slotted head 138, provides a vernier adjustment of the location of bearing pin 96 for precise calibration of the tripping mechanism.

Upon deactivation of the time controlled valve 10, the working fluid in cylinder 24 is released to permit the piston 22 to move downwardly, under the biasing force of spring 26, thereby moving actuator rod 30 downwardly until the yoke provided by slots 88 in portion 90 of rod 30 engage pin 86 in spindle 76 and pull spindle 76 downwardly until the component parts return to the intitial position illustrated in Figure 8. Since the timing mechanism 74 does not impede downward movement of spindle 76, such movement can occur rapidly. The rapid downward movement of spindle 76 brings trip arm 92 rapidly downward so that a reset means in the form of threaded pin 140 carried by trip arm 92 can engage valveoperating lever 110 and quickly move the lever 110 to the initial position shown in Figure 8 and return the shuttle 70 back to the upper position.Because reset pin 140 is threaded into a complementary threaded aperture 142 in trip arm 92, the position of reset pin 140 relative to trip arm 92 can be adjusted to accurately locate the initial position of valve-actuating lever 110. At the same time, such adjustment enables the biasing force of spring 26 to be transmitted directly to upper ball 72, through valveoperating lever 110 and shuttle 70, so as to exert a positive valve sealing force tending to enhance the effectiveness of the seal between upper ball 72 and corresponding upper valve seat 60.

Turning now to Figure 11, where it is desired to actuate valve 40 (not shown in Figure 11) upon the expiration of an interval of time measured from the deactivation of the valve 10, rather than from activation of the valve 10 as described above, the location of spring 26 is changed from between the piston 22 and gland 28 to below the piston 22, as illustrated in Figure 11. In this manner, spring 26 exerts an upwardly directed biasing force upon the piston 22.

However, upward movement of the piston 22 in response to the biasing force of spring 26 is resisted by the presence of a working fluid introduced into cylinder 24 above the piston 22, via the alternate port 34. Thus, as long as the valve 10 remains activated; that is, as long as working fluid under pressure is maintained in the cylinder 24 above the piston 22, the timing mechanism 74, spindle 76 and valve 40 will remain in the positions illustrated in Figure 8.

Upon deactivation of valve 10; that is, upon release of the working fluid from the cylinder 24 above the piston 22, spring 26 will immediately move piston 22 to the uppermost position of the piston, releasing the spindle 76 and enabling the timing mechanism 74 to operate so as to move spindle 76 upwardly toward the uppermost location thereof and actuate valve 40, all as described hereinabove. Hence, valve 40 will be actuated following the expiration of a predetermined timed interval measured from deactivation of the valve 10.

In order to facilitate the relocation of spring 26 between the two locations set forth above, piston 22 is secured to actuator rod 30 by means of a screw 150 which is easily removed to enable withdrawal of the piston 22 from actuator rod 30 for access to the portion of cylinder 24 above piston 22. A seal 152 assures fluid-tight assembly of the piston 22 and actuator rod 30.

Referring now to Figures 12 through 14, an alternate arrangement is illustrated for the actuator means at the lower end of the valve, the alternate arrangement enabling the valve to be actuated in response to short-term activating pulses, as opposed to the long-term actuating forces required in the embodiment illustrated in Figures 8 through 11.

In the time controlled valve illustrated in Figures 8 through 10, working fluid admitted through inlet port 32 to cylinder 24 below piston 22 to move piston 22 upwardly must remain in cylinder 24 to retain piston 22 in the uppermost position, against the downward bias of spring 26. Not until after the expiration of the predetermined timed interval and actuation of valve 40 is the working fluid released from cylinder 24 to allow spring 26 to reset the valve. Likewise, in the configuration of Figure 11, a working fluid must be present in the portion of cylinder 24 above piston 22 to maintain the piston 22 in the lowermost position against the bias of spring 26. In both instances, the forces provided by the working fluid are long-term activating forces.

In order to enable the time controlled valve to respond to relatively short-term activating pulses, the alternate arrangement of Figures 12 through 14 provides a fluid actuator 220 at the lower end 216 of valve 210 which, in all other respects is similar to valve 10. Fluid actuator 220 includes a piston 222 placed in a cylinder 224 for reciprocating movement upwardly and downwardly. A gland 228 closes the cylinder at the uppermost end thereof and an actuator rod 230, affixed to piston 222, extends upwardly through the gland 228 to be coupled to the spindle (not shown) of the timing device in the same manner as described above. A first inlet port 232 is provided for admitting a working fluid to the cylinder 224 below the piston 222 and a second inlet port 234 is provided above the piston 222.

Piston 222 is movable in cylinder 224 between a lower position, shown in Figure 12, and an upper position, shown in Figure 13. The piston 222. and actuator rod 230, are retained in each of the lower and upper positions by resilient detent means having detent elements located on the frame 212 and on the actuator rod 230 as follows. A spring member 240 has a base 242 from which there projects a pair of resiliently deflectable arms 244, each carrying a detent projection 246. The base 242 is secured to frame 212 by fasteners (not shown) passing through cars 248 (see Figure 14) of base 242.

The actuator rod 230 is provided with a pair of detent notches 250 spaced apart axially a distance equivalent to the travel of the piston 222, each detent notch 250 being complementary to the detent projections 246.

Upon introducing working fluid into inlet port 232, piston 222 will be moved upwardly from the lower position to the upper position. Since the piston 222, and actuator rod 230, will be retained in the upper position by engagement of the detent projections 246 with the lower detent notch 250, as seen in Figure 13, working fluid need not be maintained in the cylinder 224 below piston 222 in order for the time controlled valve to complete its timing cycle. Thus, only a short-term activating pulse of working fluid is required to activate the time control and enable the valve (not shown) of the time controlled valve to be actuated at the expiration of a predetermined timed interval following the activating pulse.Reset is achieved by introducing a working fluid into the cylinder 224 through second inlet port 234 to move piston 222 downwardly to the lower position shown in Figure 12, where the piston 222 and actuator rod 230 are retained by engagement of the detent projections 246 with upper detent notch 250.

Again, only a pulse is required since the piston and actuator rod are retained at the lower position.

It is noted that the illustrated embodiments employ a fluid-operated timing mechanism to actuate a fluid valve in response to activation or deactivation of a fluid actuator. Since all of the components are operated by fluid, or handle fluid, no electrical devices are required Thus, the time controlled valves 10 and 210 are well-suited to installations where electrical components would introduce a hazard. Of course, where no hazard would exist, fluid actuator 20 could be replaced with an electrical actuator such as a solenoid.

WHAT WE CLAIM IS: 1. A time controlled valve incorporating a housing defining separate first and second chambers, a spindle longitudinally displaceable within said first chamber, a timing unit coupled to said spindle to control longitudinal movement thereof, a fluid valve located within said second chamber and incorporating a valve seat and a cooperating movable valve member, a snap action switch located in said first chamber and coupled to said spindle, a pivotally movable lever extending through an opening in a wall separating said first and second chambers and coupling the snap action switch with the movable valve member, and a fluid tight sealing element sealing said opening and acting as a pivot for said lever, the arrangement being such that upon longitudinal movement of the spindle under the control of the timing unit the snap action switch is

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. seal 152 assures fluid-tight assembly of the piston 22 and actuator rod 30. Referring now to Figures 12 through 14, an alternate arrangement is illustrated for the actuator means at the lower end of the valve, the alternate arrangement enabling the valve to be actuated in response to short-term activating pulses, as opposed to the long-term actuating forces required in the embodiment illustrated in Figures 8 through 11. In the time controlled valve illustrated in Figures 8 through 10, working fluid admitted through inlet port 32 to cylinder 24 below piston 22 to move piston 22 upwardly must remain in cylinder 24 to retain piston 22 in the uppermost position, against the downward bias of spring 26. Not until after the expiration of the predetermined timed interval and actuation of valve 40 is the working fluid released from cylinder 24 to allow spring 26 to reset the valve. Likewise, in the configuration of Figure 11, a working fluid must be present in the portion of cylinder 24 above piston 22 to maintain the piston 22 in the lowermost position against the bias of spring 26. In both instances, the forces provided by the working fluid are long-term activating forces. In order to enable the time controlled valve to respond to relatively short-term activating pulses, the alternate arrangement of Figures 12 through 14 provides a fluid actuator 220 at the lower end 216 of valve 210 which, in all other respects is similar to valve 10. Fluid actuator 220 includes a piston 222 placed in a cylinder 224 for reciprocating movement upwardly and downwardly. A gland 228 closes the cylinder at the uppermost end thereof and an actuator rod 230, affixed to piston 222, extends upwardly through the gland 228 to be coupled to the spindle (not shown) of the timing device in the same manner as described above. A first inlet port 232 is provided for admitting a working fluid to the cylinder 224 below the piston 222 and a second inlet port 234 is provided above the piston 222. Piston 222 is movable in cylinder 224 between a lower position, shown in Figure 12, and an upper position, shown in Figure 13. The piston 222. and actuator rod 230, are retained in each of the lower and upper positions by resilient detent means having detent elements located on the frame 212 and on the actuator rod 230 as follows. A spring member 240 has a base 242 from which there projects a pair of resiliently deflectable arms 244, each carrying a detent projection 246. The base 242 is secured to frame 212 by fasteners (not shown) passing through cars 248 (see Figure 14) of base 242. The actuator rod 230 is provided with a pair of detent notches 250 spaced apart axially a distance equivalent to the travel of the piston 222, each detent notch 250 being complementary to the detent projections 246. Upon introducing working fluid into inlet port 232, piston 222 will be moved upwardly from the lower position to the upper position. Since the piston 222, and actuator rod 230, will be retained in the upper position by engagement of the detent projections 246 with the lower detent notch 250, as seen in Figure 13, working fluid need not be maintained in the cylinder 224 below piston 222 in order for the time controlled valve to complete its timing cycle. Thus, only a short-term activating pulse of working fluid is required to activate the time control and enable the valve (not shown) of the time controlled valve to be actuated at the expiration of a predetermined timed interval following the activating pulse.Reset is achieved by introducing a working fluid into the cylinder 224 through second inlet port 234 to move piston 222 downwardly to the lower position shown in Figure 12, where the piston 222 and actuator rod 230 are retained by engagement of the detent projections 246 with upper detent notch 250. Again, only a pulse is required since the piston and actuator rod are retained at the lower position. It is noted that the illustrated embodiments employ a fluid-operated timing mechanism to actuate a fluid valve in response to activation or deactivation of a fluid actuator. Since all of the components are operated by fluid, or handle fluid, no electrical devices are required Thus, the time controlled valves 10 and 210 are well-suited to installations where electrical components would introduce a hazard. Of course, where no hazard would exist, fluid actuator 20 could be replaced with an electrical actuator such as a solenoid. WHAT WE CLAIM IS:

1. A time controlled valve incorporating a housing defining separate first and second chambers, a spindle longitudinally displaceable within said first chamber, a timing unit coupled to said spindle to control longitudinal movement thereof, a fluid valve located within said second chamber and incorporating a valve seat and a cooperating movable valve member, a snap action switch located in said first chamber and coupled to said spindle, a pivotally movable lever extending through an opening in a wall separating said first and second chambers and coupling the snap action switch with the movable valve member, and a fluid tight sealing element sealing said opening and acting as a pivot for said lever, the arrangement being such that upon longitudinal movement of the spindle under the control of the timing unit the snap action switch is

triggered after a predetermined time controlled interval whereupon said valve member is snapped from or to a sealed position with the cooperating valve seat.

2. A time controlled valve according to claim 1, wherein the snap action switch incorporates a spring biassing the lever to locate the movable valve member in a first position, a latch mounted for movement about a pivot between a position in engagement with said lever to restrain the latter from movement under the influence of said spring and a position in which said lever is released to snap the valve member to a second position under the influence of said spring and a trip carried by said spindle and cooperating with said latch to move said latch from said restraining position to said releasing position upon controlled longitudinal sliding movement of said spindle.

3. A time controlled valve according to claim 1 or claim 2, wherein an actuator is housed within an isolated third chamber and incorporates a member selectively movable between first and second positions, a spring urging said actuator member toward one of said positions, and a coupling between said actuator member and the longitudinally displaceable spindle to permit longitudinal sliding movement of said spindle when said actuator member is in one of said positions and prevent spindle movement when the actuator is in the other of said positions.

4. A time controlled valve according to claim 3, wherein the movable actuator member is a piston and is selectively movable by the pressure of fluid introduced through ports respectively opening into a piston cylinder towards opposite ends thereof.

5. A time controlled valve substantially as hereinbefore described with reference to the accompanying drawings