DESC:Field of invention

The present invention relates to a valve for fluids, and more particularly, to the temperature responsive shut-off valve.

Background of the invention

Many industrial processes require measurement of contaminants to ensure quality of liquid passing through equipment. The most common way to measure the quality of liquid is to pass representative sample of liquid through various analyzers which measure the quality of sample. Very often these analyzers require sample to be conditioned below certain pressure and temperature. If the pressure or temperature of the sample to be analyzed exceeds the limit, it may result in the failure of the analyzer. Hence, it is very important to safeguard the analyzers against increased temperature. Also, it is important to block the flow of fluid to the analyzers till the time the root cause of increased sample temperature is diagnosed and addressed.

US Patent No. 5826790 discloses a temperature-sensitive valve for handling liquids. The valve includes a housing having a valve seat and a valving member mounted for movement from a flow-permitting first position spaced from the seat to a flow-blocking second position against the seat. A latching mechanism is coupled to the valving member for retaining such member in the first position when the temperature of the liquid is below a shutoff temperature. A temperature-sensitive device is mounted in the valve body and has an actuator coupled to the latching mechanism. The valve body has a chamber containing the sensing portion of the temperature-sensitive device and also has flow apertures positioned so that when the valve is open, liquid flows across and is in contact with the sensing portion for excellent heat transfer and quick response. The latching mechanism is released and the valving member moves to the second position when the temperature of the liquid is above the shutoff temperature. Sensitive analyzing instruments are thereby protected from exposure to liquids, the temperature of which may be damaging to the instruments.

Another German Patent DE20306025 discloses a thermal closure valve. The valve has a mechanically acting expansion element and shuts off a liquid flow immediately without the input of external energy with an axially moving a sliding element and suitable sealing rings. The device operates without electric current. Very fast, pressure-tight sealing up to a maximum of 400 bars with zero output quantity takes place with a spring-loaded mechanism.

However, the temperature responsive shut off valves of the prior art have following drawbacks.

A. The prior art valves uses spherical ball or pin which has two way movement; hence there is difficulty in resetting the valve.
B. The prior art valves does not use antifriction element; hence there is wear and tear of the valve component.
C. The prior art valves require more manual force to reset.
D. The prior art valves do not have provision of relief valve.

Accordingly, there exists a need to provide a temperature responsive shut off valve, which overcomes abovementioned drawbacks.

Objects of the invention

An object of the present invention is to reduce wear and tear of a temperature responsive shut off valve.

Another object of the present invention to reduce manual effort required to reset the temperature responsive shut off valve.

Yet another object of the present invention is to provide enhanced safety to the temperature responsive shut off valve.

Summary of the invention

Accordingly, the present invention provides a temperature responsive shut-off valve (TRSV) (100) for fluids. The TRSV (100) comprises housing (50) having a first open end (10), a second open end (20), a third open end (30) and a fourth open end (40).

The TRSV (100) further comprises a first cap (12) configured on the first open end (10). The first cap (12) includes at least oneport. The port acts as an inlet for fluid sample, wherein the inlet is connected to a chamber (51) and then a chamber (52). The first cap (12) further includes a ball (14) enclosed in the chamber (52) moving freely within the chamber (52), and a pin (16) configured within the chamber (52)for keeping the ball (14) within the chamber(52). The first cap (12) also includes a plurality of tapered holes(12a) configured thereon which facilitates entry of the fluid from the inlet to the housing (50).

The TRSV (100) furthermore comprises a second cap (22) configured on the second open end (20) of the housing (50). The second cap (22) includes a shaft (24) configured therein. The shaft (24) is capable of moving axially, In an embodiment, the shaft (24) is guided by an antifriction element (24a). Further, the second cap (22) includes a cam (26) connected to the shaft (24) inside the housing (50), a screw (28) configured on the shaft (24) on side of the third open end (30) of the housing, and a spring (22a) configured in the cap (22);

The TRSV (100) moreover includes a third cap (32) configured on the third end (30) of the housing (50). The third cap (32) includes a temperature responsive element (34) configured within the cap (32) in such a way that flow of the fluid passes over the temperature responsive element (34) before exiting through outlet. The third cap (32) further includes a pin (36) configured on the temperature responsive element (34) for giving a stroke when the temperature of the fluid passing over the temperature responsive element (34) rises and crosses a trigger temperature. Specifically, the screw (28) adjusts for the gap between the shaft (24) and the pin (36).

The TRSV (100) also includes a piston (42) enclosed on the fourth open end (40) of the housing (50). The piston (42) includes a cam profile slot (42a). Specifically, the piston is guided by a bush (42b) and a nut (42c) at one end and the pin (16) of the chamber (52)at the other end. The piston (42) also includes a spring (44) wounded thereon allowing the piston (42) to move axially inside the housing (50). Further, a reset lever (46) is pivoted to the piston (42).

Specifically, when the temperature of the fluid reaches the trigger temperature value, the pin (36)of temperature-responsive element (34) starts pushing the screw (28) thereby moving the shaft (24) and compressing the reset spring (22a). Thereafter, the cam (26) guides over the cam profile (42a) of the piston (42) thereby pushing the piston (42) in forward direction due to expansion of spring (44) and the pin (16) pushes the ball (14) to close the inlet.

Brief description of the drawing

Figure 1 shows a temperature responsive shut off valve in open condition, in accordance with the present invention;

Figure 2 shows a reset button position when the temperature responsive shut off valve is in open condition;

Figure 3 shows a temperature responsive shut off valve in closed condition, in accordance with the present invention;

Figure 4 shows a reset button position when the temperature responsive shut off valve is in closed condition; and

Figure 5 shows a temperature responsive shut off valve with an alarm contact, in an embodiment of the present invention.

Detailed description of the invention

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.

Accordingly, the present invention provides a temperature responsive shut off valve. The temperature responsive shut off valve uses an antifriction element which reduces wear and tear. Further, a cam guiding over a profile of an actuator reduces effort of manual reset. Furthermore, the temperature responsive shut off valve of the present invention provides enhanced safety to liquid analyzers by providing liquid sample below predefined temperature.

The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

Referring now to figure 1-4, there is shown a temperature responsive shut-off valve (100) (hereinafter referred to as “the TRSV (100)”). The TRSV (100) includes housing (50). The housing (50) includes a first open end (10), a second open end (20), a third open end (30) and a fourth open end (40).

The first open end (10) of the housing (50) comprises a first cap (12) configured thereon. The first cap (12) includes at least one port configured thereon. Specifically, the port acts as an inlet for fluid sample. Further, the inlet is connected to a chamber (51) and then a chamber (52) as shown in figure 1. The first cap (12) further includes a ball (14) enclosed in the chamber (52) moving freely within the chamber (52)and a pin (16) configured within the chamber(52) for keeping the ball (14) within the chamber(52). The first cap (12) also includes a plurality of tapered holes which facilitate entry liquid from inlet to the housing (50) when the TRSV (100) is in open condition.

In an embodiment, the first cap (12) includes a plug moving freely within the chamber (52) to close the valve.

Further, the second open end (20) of the housing (50) comprises a second cap (22) configured on thereon. The second cap (22) includes a shaft (24) configured therein. Specifically, the shaft (24) is capable of moving axially. In an embodiment, the shaft (24) is guided by an antifriction element (24a). The second cap (22) further includes a cam (26) connected to the shaft (24) inside the housing (50).In another embodiment, the second cap (22) furthermore includes a screw (28) configured on the shaft (24) on side of the third open end (30) of the housing, and spring (22a). The spring (22a) in the cap (22) is used to reset the TRSV (100). Specifically, the antifriction element(24a) keeps the concentricity of shaft (24) within the second cap (22).

Furthermore, the third open end (30) of the housing (50) comprises a third cap (32) configured thereon. The third cap (32) includes a temperature responsive element (34) configured therewithin such a way that flow of the fluid passes over the temperature responsive element (34) before exiting through outlet. The third cap (32) further includes a pin (36) configured on the temperature responsive element (34) for giving a stroke when the temperature of the fluid passing over the temperature responsive element (34) rises and crosses a trigger temperature. Specifically, the screw (28) adjusts for the gap between the shaft (24) and the pin (36) during operation of the TRSV (100). In an embodiment, the temperature responsive element used is wax.

Moreover, the fourth open end (40) of the housing (50) comprises a piston (42) enclosed thereon. The piston (42) includes a cam profile slot(42a) configured thereon. Specifically, the piston (42) is guided by a bush (42b) and a nut (42c) at one end and the pin (16) of the chamber (52) at the other end i.e. at the end of cam profile (42a). The piston (42) further includes a spring (44) wounded for allowing the piston (42) to move axially inside the housing (50) and a reset lever (46) pivoted thereon. Specifically, the spring (44) decides the opening and closing of the TRSV (100). The reset lever (46) is pivoted to the piston (42) and facilitates the indication of TRSV (100) closure and can be used to set the valve open.

As shown in figure 5, the fourth open end (40) also includes an alarm contact (61) mounted on thereon for giving the signal when the TRSV (100)is operated. When TRSV (100) is open, the pin of alarm contact (not shown) is in contact with piston (42). When TRSV (100) gets closed, then the piston (42) moves away from the pin of alarm contact (61) thus breaking the contact.

During operation, initially the TRSV (100) is in open condition as shown in Figure1 with reset lever (32) position as shown in Figure2. The cam (26) rests on the vertical face of cam profile (42a) of the piston (42) arresting the forward motion of the piston (42). Further, the sliding bearingkeeps the concentricity of shaft (24) with the second cap (22) under the load of spring (22a).

Specifically, the liquid or fluid enters in the housing (50) through the inlet port, to the chamber (52) and passes over the temperature-responsive element (34) and then exits though outlet of the third cap (30).

More specifically, when the temperature of the liquid reaches the trigger temperature value, then the pin (36) of temperature-responsive element (34) starts pushing the screw (28). The screw (28) is the adjusting screw and the shaft (24) move and, compressing the reset spring (22a). Simultaneously, the cam (26) guides over the cam profile (42a) of the piston (42). When the cam (26) guides over the inclined cam profile(42a) of the piston (42), the latching gets removed and the piston (42) moves forward due to expansion of spring (44). As the pin (16) of the chamber (52)is located at the end of cam profile (42a) of the piston (42), the pin (16) pushes the spherical ball (14) to close the inlet and hence closing the TRSV (100).

During the forward motion of the piston (42), the reset lever (46) rotates about pivot due to its profile guiding over the nut (42c)and settles at a position away from the valve as shown in figure 4. This position gives the indication of the TRSV (100) closure. The TRSV (100) remains in closed condition until reset manually.

In an embodiment, the TRSV (100) can be reset manually only when the temperature inside the valve as sensed by temperature-responsive element (34) drops below the trigger temperature. When this condition reaches, the TRSV (100) can be reset by pressing the reset lever (46) manually towards the TRSV (100). The pressing of reset lever (46) facilitates the backward motion of the piston (42) compressing the spring (44). Due to expansion of spring (22a), the shaft (36) moves down while the cam (26) guides over the cam profile(42a) of the piston (42) and settles on the vertical face of cam profile (42a). At this position, the mechanism gets latched even if the force on the reset lever (46) is withdrawn. Now the TRSV (100) is in open condition.

In an embodiment, a sensor (not shown) is mounted on the TRSV (100). The sensor provides an electrical output indicating the "OPEN" and "CLOSE" condition of TRSV (100) which serve the purpose of remote monitoring of TRSV (100).

Advantages of the invention

1. The temperature-responsive shut-off valve (TRSV (100)) is guided in all four sides for smooth operation.
2. The TRSV (100) is subjected to low wear and tear due to use of antifriction element.
3. In the TRSV (100), a small displacement of pin in temperature-responsive element is amplified to a large displacement of mechanism.
4. The TRSV (100) provides low reset time due to cooling off the temperature-responsive element by convection.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.
,CLAIMS:We Claim:

1. A temperature responsive shut-off valve (100) for fluids comprising:
housing (50) having a first open end (10), a second open end (20), a third open end (30) and a fourth open end (40);
a first cap (12) configured on the first open end (10), the cap (12) having,
• at least one port, which acts as an inlet for fluid sample, the inlet is connected to a chamber (51) and then a chamber (52),
• at least one ball (14) enclosed in the chamber (52)moving freely within the chamber(52),
• a pin (16) configured within the chamber (52)for keeping the ball (14) within the chamber(52), and
a second cap (22) configured on the second open end (20) of the housing (50), the second cap (22) having,
• a shaft (24) configured therein, the shaft (24) capable of moving axially;
• a cam(26) connected to the shaft (24) inside the housing (50);
• a spring (22a) configured in the cap (22);
a third cap (32) configured on the third end (30) of the housing (50), the third cap (32) having,
• a temperature responsive element (34) configured within the cap (32) in such a way that flow of the fluid passes over the temperature responsive element (34) before exiting through outlet,
• a pin (36) configured on the temperature responsive element (34) for giving a stroke when the temperature of the fluid passing over the temperature responsive element (34) rises and crosses a trigger temperature, wherein the screw (28) adjusts for the gap between the shaft (24) and the pin (36); and
a piston (42) enclosed on the fourth open end (40) of the housing (50), the piston (42) having a cam profile slot (42a), the piston being guided by a bush (42b) and a nut (42c) at one end and the pin (16) of the chamber (52)at the other end;
a spring (44) configured on the piston (42) allowing the piston (42) to move axially inside the housing (50); and
a reset lever (46) is pivoted to the piston (42);
wherein, when the temperature of the fluid reaches the trigger temperature value, the pin (36)of temperature-responsive element (34) starts pushing the screw (28) thereby moving the shaft (24) and compressing the reset spring (22a), thereafter, the cam(26) guidesover the cam profile (42a) of the piston (42) thereby pushing the piston (42) in forward direction due to expansion of spring (44) and the pin (16) pushes the ball (14) to close the inlet.

2. The temperature responsive shut-off valve (100) as claimed in claim 1, wherein the shaft (24) is guided by an antifriction element (24a)within the second cap (22).

3. The temperature responsive shut-off valve (100) as claimed in claim 1, wherein the shaft (24) includes a screw (28) configured thereon on side of the third open end (30) of the housing.

4. The temperature responsive shut-off valve (100) as claimed in claim 1, wherein the reset lever (46) rotates about pivot due to its profile guiding over the nut (42c) and settles at a position away from the valve when the piston (42) moves in forward direction thereby closing the valve.

5. The temperature responsive shut-off valve (100) as claimed in claim 1, wherein, the firstcap (12)of the first open end (10) includes a plurality of tapered holes (12a) adapted thereon which facilitates entry of the fluid from the inlet to the housing (50);

6. The temperature responsive shut-off valve (100) as claimed in claim 1, wherein temperature responsive shut-off valve (100) is be reset manually only when the temperature inside the valve as sensed by temperature-responsive element (34) drops below the trigger temperature.

7. The temperature responsive shut-off valve (100) as wherein a sensor is provided an electrical output indicating the "OPEN" and "CLOSE" condition of the TRSV (100) which serve the purpose of remote monitoring of TRSV (100).

8. The temperature responsive shut-off valve (100) as claimed in claim 1, the fourth open end(40) includes an alarm contact (61) mounted thereon for givinga signal when the TRSV (100) is operated.

9. A temperature responsive shut-off valve (100) for fluids comprising:
housing (50) having a first open end (10), a second open end (20), a third open end (30) and a fourth open end (40);
a first cap (12) configured on the first open end (10), the cap (12) having,
• at least one port, which acts as an inlet for fluid sample, the inlet is connected to a chamber (51) and then a chamber (52),
• aplug moving freely within the chamber (52) to close the valve,
a second cap (22) configured on the second open end (20) of the housing (50), the second cap (22) having,
• a shaft (24) configured therein, the shaft (24) capable of moving axially,
• a cam (26) connected to the shaft (24) inside the housing (50); and
• a spring (22a) configured in the cap (22);
a third cap (32) configured on the third end (30) of the housing (50), the third cap (32) having,
• a temperature responsive element (34) configured within the cap (32) in such a way that flow of the fluid passes over the temperature responsive element (34) before exiting through outlet,
• a pin (36) configured on the temperature responsive element (34) for giving a stroke when the temperature of the fluid passing over the temperature responsive element (34) rises and crosses a trigger temperature, wherein the screw (28) adjusts for the gap between the shaft (24) and the pin (36); and
a piston (42) enclosed on the fourth open end (40) of the housing (50), the piston (42) having a cam profile slot (42a), the piston being guided by a bush (42b) and a nut (42c) at one end and the pin (16) of the chamber (52) at the other end;
a spring (44) configured on the piston (42) allowing the piston (42) to move axially inside the housing (50); and
a reset lever (46) is pivoted to the piston (42);
wherein, when the temperature of the fluid reaches the trigger temperature value, the pin (36)of temperature-responsive element (34) starts pushing the screw (28) thereby moving the shaft (24) thereby compressing the reset spring (22a), thereafter, the cam (26) guidesover the cam profile (42a) of the piston (42) thereby pushing the piston (42) in forward direction due to expansion of spring (44) and the pin (16) pushes the ball (14) to close the inlet.