US1983183A - Valve - Google Patents

Description

Dec. 4, 1934.

R. E. NEWELL El AL VALVE Filed April 22, 1955 Patented Dec. 4, 1934 PATENT v VALVE Robert E. Newell, Irwin, and John A. Robertshaw,

Greensburg, Pa., assignors to Robertshaw 'llhermostat Company, Youngwood, Pa., a corporation of Pennsylvania Application April 22, 1933, Serial No. 667,488

12 Claims.

The present invention relates broadly to the art of fluid control, and more particularly to an improved valve construction for effecting control of fluid flow.

It is customary in the art to which our invention relates to efiect such control by means of thermostatic or pressure operated valves. Such valves as heretofore used have generally been of two types. For purposes of convenience, these types may be referred to as the throttling type and the so-called snap-action type, theidifierences between which are well recognized; Both types of valves possess certain desirable characteristics but these desirable characteristics are peculiar to the types, and neither of the two types possess the desirable characteristics of the other.

1 It has heretofore been proposed to combine the two types of valves in order to provide a unitary structure possessing the desirable characteristics of both types of valves. In the copending application of Robert E. Newell, Serial No. 471,723,

there is shown and described a construction wherein the advantages of both the throttling type and the snap-action type of valves may be obtained in a unitary structure. Such structure, however, includes both a snap-acting valve and a throttling valve, and isv relatively complicated, and the cost of manufacture thereof is relatively high.

-' By our invention we provide a control device or valve construction wherein the advantages of both the throttling type valve and the snap-action type valve may be obtainedin a single valve structure without utilizing two separate valves as heretofore proposed.

In accordance with our invention, we provide a control device or valve construction such that a fraction of its total capacity, which fraction may be either'relatively large or small, may be opened or closed with a snap while the remainder of the valve capacity is made available or cut off by a gradual or throttling action upon further changes in conditions which it is desired to control, such, for example, as further increases or decreases in temperature beyond those at which the snap-action occurs.

In accordance with the preferred embodiment of our invention, we provide a control device or valve mechanism wherein the snap action is obtained by means of a flexible element which is of such character that it will not be damaged by over-strains, and which, after the snap-action has occurred and the control means operated by a snap movement, will continue to operate the control means above the snap range with a graduated action without straining any of the valve mechanism. One of theadvantages of such a structure is that it may be operated over a greater range of temperatures, jamming of the parts avoided, and the advantages of both the throttling and snap-action valves obtained in a unitary structure. In accordance with the preferred embodiment of our invention, the flexible element is a concave spring steel tape. A flexible element 5 of this character in effecting the snap-action changes from a concave strip to a flat strip. This is advantageous over the usual concavo-convex type of flexible element, as it is of such characacter to enable it to continue to bend after the 7 snap has occurred without undue straining of the metal.

Control devices of the above character may be advantageously'used in the control of temperatures of either liquids or gases. Where the temperature of a liquid is to be controlled and the thermostatic element extends from the control device into the liquid whose temperature is to be controlled, it is desirable to provide suitable sealing means to prevent the escape of the liquid 30 into the control device or valve mechanism. Consequently, by our invention we also provide novel sealing means for preventing leakage of the fluid directly into the gas passage to the burner.

In the accompanying drawing, we have shown for purposes of illustration only, a preferred embodiment of our invention.

In the drawing- Figure 1 is a sectional view through the struc- 90 ture which we provide, the thermostatic element being partially shown'in elevation, and the parts being shown in normal or inoperative position;

Figure 2 is a sectional view similar to that shown in Figure 1 with the parts shown in an 5 operative position;

v Figure 3 is an elevational view of the flexible element and the connecting link shown in Figures 1 and 2;

Figure 4 is an elevational'view of the flexible c element and connecting link shown in Figure 3 taken at right angles to the showing of Figure 3; and

Figure 5 is a sectional view taken along the line V-V of Figure 3.

Referring to the drawing, there is illustrated a valve structure comprising a suitable casing 2 having an inlet port 3 and 'an outlet port 4 therein, the flow between which is controlled by the novel structure which we provide by our in- 11 vention. A valve member 5 is provided between the inlet and outlet ports and cooperates with a valve seat 6 threaded in the valve casing. The valve seat 6 has a plurality of openings '7 therethrough through which the fluid passes in its passage from the inlet opening to the outlet opening of the structure. One end of a spring 8 surrounds a boss 9 carried by the valve member and bears at its opposite end against a cap 10 and yieldably urges the valve member against its seat 6. The cap 10 is threaded into the easing 2 and may be readily removed to permit access to the ports.

A valve. stem or pin 11' extends throughan opening 12 in the valve seat 6 and is adapted to cooperate with the flexible element 13 for opening the valve to permit fluid to flow between the inlet and the outlet openings. The stem or pin bears at its free end against the flexible element 13 when said element is in a flexed position and is spaced a slight distance from it when the parts are in the position shown in Figure 1.

As shown in the drawing, the flexible element through which both the snap-action and the throttling action are imparted to the valve comprises a short piece of concave spring steel tape. The upper end of the flexible element 13 is riveted or otherwise suitably secured to a connecting lever 14 located in the outlet passage 4 of the valve structure. The connecting lever 14 is provided adjacent the upper end thereof with a recess 15 adapted to cooperate with one end of a gland pin 16 adapted to be actuated by the thermostat indicated generally by the reference character 17. The extreme upper end of the connecting lever 14 is provided with an opening 18 adapted to cooperate with and receive a pin 19 carried by an adjusting screw 20 extending through a threaded opening in an extension 21 on the upper portion of the valve casing 2. As shown in the drawing, the upper end of the connecting lever 14 is bent inwardly adjacent the opening 18 to provide bearing surfaces 22 adapted to bear against the rear face of the adjusting screw 20 carrying the pivot pin 19.

The lower end of the flexible element 13 is provided with a concave substantially U-shaped reinforcing member 23 which is secured to the lower end of the flexible member by a rivet 24 having a bearing surface 25 which cooperates with an adjusting screw and stop member 26 carried by the valve casing. w

The valve casing is provided with an extension 32 adjacent the upper end thereof. The extension 32 has a threaded portion 33 which may be threaded in a suitable opening 34 of a boiler-35, or any other structure to which it is to be 'attached.

The extension 32 is provided with an opening 36 into which the gland pin 16 extends. This opening has an enlarged portion 37 which is threaded to receive the threaded end of the expansible tube. 30 of the thermostat. The one end of the gland, pin 16 bears against the inner end of the non-expansible rod 31 and any movement thereof is transmitted by the pin 16 to the flexible element through the connections and parts described hereinbefore.

Where the thermostat 17 extends into a liquid whose temperature is to be controlled, it'is desirable to provide suitable means for preventing the liquid from leaking past the thermostat tubethreads and into the gas conduit of the valve structure. Accordingly, a sump 41 is provided in the extension 32 for collecting any water that leaks past the threads, and suitable openings 42 are provided to discharge any water collected in the sump. -'Ihe gland pin 16 is suitably ma chined to form a seal with the passageway 36 'to prevent the escape of gas from the valve casing into the sump 41.

The valve structure above described having been properly calibrated, and the indicator with which such structures are generally provided set at-a temperature-of-130, for example, if the medium being controlled is at a temperature of 140, for example, the parts of the valve will be in the position illustrated in Figure 1, wherein the valve member is effective for preventing fluid flow through the casing. When the medium cools to a temperature of 130", or slightly below, the rod 31 of the thermostat pushes the gland pin 16 inwardly and forces the lower portion of the lever 14 carrying the flexible element 13 inwardly until the bearing surface 25 on the lower end of the flexible element engages the stop pin 26. A further fall of 15 or 20, for example, will develop sufficient strain on the flexible strip to cause it to snap and take the bent position as shown in Figure 2, thereby moving the valve member 5 away from its seat 6 by a snap action.

In the event of a further drop in the temperature of the medium being controlled, the lever 14 will continue to flex the flexible element 13, causing the valve member 5 to further recede from its seat 6 with a gradual movement. The valve member 5 may be gradually moved a substantial distance without danger of straining or damaging the strip. Thus, there is secured in this one valve structure an operation characterized by an initial snap action followed by a subsequent throttling or graduated action.

Upon reversal of temperatures, the release of pressure from the valve member 5 through the stem 11 permits the spring 8 togradually force the valve member back towards its seat. Thereafter, at a predetermined temperature, the snap action will occur and completely cut 011 the supply of fluid being controlled, and the flexible element 11 will assume a non-flexed or inoperative position, such as shown in Figure 1 of the drawing.

As can be readily seen, the structure which we provide can be much more economically manufactured than a. structure utilizing two separate valves, one a snap-acting valve and the other a slow-moving or throttling valve, and that the structure which we provide can be used where the temperatures being controlled vary over a wide range. Ordinary concavo-convex diaphragms, such as have been used in snap-action devices heretofore, have a very limited movement. After snapping from a concave position, they instantly assume a convex position which limits their further movement. In the event of wide variations of temperature, they suffer permanent distortion by the resulting over-strains. As can be readily seen, these conditions are clearly overcome in the structure which 'we provide.

While we have shown and described a preferred embodiment of our invention, it will be understood that we do not intend to be limited thereby, but that the invention may be otherwise embodied within the scope of the appended claims.

We claim: Y

1. A control device comprising a trough 3 shaped flexible element, means for actuating said element, a stop member adjacent one end of said'flexible element and adapted to limit the movement thereof, and control means between said actuating means and said stop member cent one end of said flexible element and adapted to limit the movement thereof, and control means between said actuating means and said stop member adapted to be operated by the flexing of said element by the actuating means.

3. A control device comprising a substantially trough-shaped flexible element adapted to move from a normal non-flexed position to a flexed position with a snap-action, means for flexing said element, and control means intermediate the ends of said element adapted to be operated by the flexing thereof.

4. A control device comprising a flexible element adapted to move from a non-flexed position to a flexed position with a snap-action, ac-

tuating means operatively connected with said element adjacent one end thereof, stop means adjacent the other end of said element adapted to limit the movement .thereof, and control means intermediate the ends of said element adapted to be operated by the flexing thereof.

5. A control device comprising'asubstantially trough-shaped flexible element adapted to move from a non-flexed position to a flexed position with a snap-action, control means intermediate the ends of said element adapted to be' operated by the flexing of said element, and means for flexing said element to impart the snap-action thereto and for thereafter effecting further flexing of said element. I

6. A control device comprising a flexible member adapted to move to a flexed position with a snap-action, control means intermediate the ends of said element adapted to be operated by the flexing of said element, and means for flexing said element to impart the snap-action thereto and for thereafter effecting further flexing of said element, whereby a snap-action is imparted to the control means followed by a graduated movement.

7. A control device comprising a substantially trough-shaped flexible element adapted to move to a flexed position with a snap-action and to return to substantially normal position with a snap-action, actuating means for flexing said element, control means intermediate the ends of said element adapted to be operated by the flexing of said element, and means for returning said control means to normal position as said flexible element returns to normal position.

8. A control device comprising a flexible element adapted to move from a normal position to a flexed position with a snap-action, control means intermediate the ends of said element element cooperating with said valve member for gin) adapted to be operated by the flexing thereof, means for flexing said element to impart a snapaction thereto and for thereafter effecting further flexing of the element, and means for returning said control means to normal position as said element returns to normal position.

9. In a valve, a casing having an inlet and an outlet port, a valve member in said casing between said inlet and outlet ports, a flexible operating the same, said flexible element being adapted to move from a normal position to a flexed position with a snap-action, and means for flexing the flexible element to impart a snapaction thereto and for thereafter effecting further flexing thereof, whereby a snap-action is imparted to said valve member followed by a further gradual movement.

10. In a valve, a casing having an inlet and an outlet port, a valve member in said casing between said inlet and outlet ports, a flexible element cooperating with said valve member for operating the same, said flexible element being adapted to move from a normal position to a flexed positionwith a snap-action, means for flexing the flexible element to'impart a snapaction thereto and for thereafter effecting further flexing thereof, whereby a snap-action is imparted to, said valve member followed by a further gradual movement, and means for returning said valve member to normal position.

11. In a valve, a casing having an inlet and an outlet port, a valve member in said casing between said inlet and outlet ports, a flexible element mounted in said casing and adapted 11 to operate said valve member, said flexible ele-' ment being normally in a non-flexed position and adapted to move from a non-flexed position to a flexed position with a snap-action, and means for actuating said flexible element to effect a snapaction thereof and for thereafter effecting a further gradual flexing thereof.

12. In a valve, a casing having an inlet and an outlet port, a valve member in said casing between said inlet and outlet ports, a flexible element mounted in said casing and adapted to operate said valve member, said flexible element being normally in a nonflexed position and adapted to move from a non-flexed position to a flexed position with a snap-action, and means for actuating said flexible element to effect a snap-action thereof and for thereafter effecting a further gradualv flexing thereof. whereby an initial snap-action and a subsequent slow gradual movement is imparted to said valve member.

ROBERT E. NEWELL. JOHN A. ROBERTSHAW.

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