US3019985A

US3019985A - Heat exchanger valve

Info

Publication number: US3019985A
Application number: US862581A
Authority: US
Inventors: Grosjean Kurt
Original assignee: Landis and Gyr AG
Current assignee: Landis and Gyr AG
Priority date: 1959-01-14
Filing date: 1959-12-29
Publication date: 1962-02-06
Anticipated expiration: 1979-02-06

Description

K. GROSJEAN INVENTOR Kurt Grosjeon W,.W9mfw'ze ATTORNEYS United States Patent Ofitice 7 3,019,985 Patented Feb. 6, 1962 3,019,985 HEAT EXCHANGER VALVE Kurt Grosjean, Zug, Switzerland, assignor to Landis &

Gyr, A.G., Zug,-Switzerland, a corporation of Switzerland Filed Dec. 29, 1959, Ser. No. 862,581 (llaims priority, application Switzerland Jan. 14, 1959 3 Claims. (Cl. 236-1) This invention relates to a thermostatic, heat-exchanger regulator valve for automatic changeover to heating or cooling regulation and more particularly to such a valve having improved control valve means. I

A known thermostatic, heat-exchange regulator valve for automatic changeover to heating or cooling regulation such as disclosed in Patent No. 2,936,121 issued to the assignee of the instant application, comprises a diaphragm pressure member which is subject to a desired-value setting and detects the room temperature by means of a liquid temperature sensor and also includes a control valve having two throttle members working in opposition, one of which is effective during heating operation and the otherduring cooling operation. This control valve is subject to theinfluence of the diaphragm pressure member and controls a hydraulic servornotor for opening and closing the main valve. The changeover of the throttle members of the control valve, on changing the installation from heating to cooling or vice versa, is efi'ected automatically by means of a bimetal disc which is exposed to the temperature of the heating or cooling medium. In the known arrangement the throttle members of the control valve are constructed in the form of poppet valves arranged one behind the other and the bimetal disc is a snap disc. Both the poppet-valvertype throttle members, and the bimetal snap spring, have proved unsuitable in that these means are difficult to adjust. j The object of the present invention is an improvement to said control valve. A specific object of the invention is to provide a valve capable of being readily'and accurately adjusted.

Another object of the invention is to provide a valve capable of being adjusted for difierent conditions in which said adjustments may be independently made.

These and other objects and advantages of'the inventionwill be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims. 1

The invention, briefly and generally, comprises a thermostatic heat exchanger regulator valve for automatic changeover to heating or cooling regulation and includes a control valve for a hydraulic servomotor which consists of a two-armed rocker which carries two bimetal strips bending in opposite directions and additionally includes two throttle members constructed in the form of ball valves, each of said ball valves and the free end of each bimetal strip lying respectively under each end of the rocker. Dependingon the temperature of the heating or cooling medium, one or the other bimetal strip acts on the associated ball valve while the other bimetal strip is bent out of its range of action towards the rocker; the control is eifected as a result of the fact that the diaphragm pressure member presses on one rocker arm and a compression spring acting as a counteracting force presses on the other rocker arm. The particular ball valve which is inoperative is held closed by a leaf spring.

In one embodiment of the invention automatic changeover of the control valve to heating or cooling is accomplished within a very narrow temperature range of the drop of the medium and hence a precise dimensioning of the required servo force is rendered possible. I

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described. 7 t 7 One embodiment of the subject of the invention is illus trated diagrammatically by way of example in the draw- The housing of the regulator valve consists of four parts, namely a lower part-1 with the base 23, an upper part 6 and a cover 1 6. The lower part 1 of the housing has an inlet connection2, an outlet connection 3 and a cylindrical center portion 4 in the axis of which is mount ed the main valve 5 for opening and closing. The upper part 6 of the housing is mounted on the cylindrical center portion 4. The parts 4 and 6 of the housing together form a hollow chamber which is divided by a setting diaphragm 7 into a low-pressure chamber 8 and a highpressure chamber 9. The, pressure drop for the two

chambers

8 and 9 is produced as a result of the fact that in the lower part 1 of the housing, the passage between the inlet and outlet connections :2 and 3 respectively is constructed in the form of a venturi tube 10; the highpressure chamber 9 is connected by athrottle 12 and a high-pressure passage 11 to the inlet 2; and the lowpressure chamber 8 is connected by a low-pressure passage 13 to the constricted part of the outlet '3 behind the main valve 5. In orderto control the pressure drop, the high-pressure chamber 9.is connectedto the low-pressure chamber 8 through a control valve mounted on a plate 14, with two ball valves 21, 22 serving as throttle members. The connection is completed-through a passage 15.-

Mounted on the upper part of the housing is the cover 16 which comprises a diaphragm pressure member 17 which is connected through a capillary tube, 18 top liquid temperature sensor which is not illustrated. The position of-the diaphragm pressure member 17 'can be adjusted inrelation to the control valve by means of adesired-value setscrew 19 in order to set the temperature to be maintained. The diaphragm pressure member 17 acts .by means of a push rod .20 on the control valve device.

In order to produce an opposing force for the setting diaphragm 7, there is provided in a hollow space between the 'lower part 1 of the housing and the base 23, a restoring diaphragm 24 which divides the hollow space into a lower high-pressure chamber'26'connected through a passage 25 to the inlet 2, and-an upper low-pressure chamber 28 connected through a passage 27 to the constricted part of the outlet 3. The pressure of the heating orcooling medium on the restoring diaphragm 24 is not controlled and depends on the pump pressure. If the control force on the setting diaphragm 7 is greater than the counteracting force on the restoring diaphragm 24, the main valve 5 is closed; if the control force is less, it is open. v V V The control valve comprises a twoarmed r'ocker 30 which is pivotal-lymounted about a pin 29 or, preferably, on pivots or knife edges, and which is arranged in such a manner that the ball valve 21 is below the left-hand end and the ball valve 22 below the right-hand end of the rocker 30. On the under side of the rocker, that is to say on the side facing the plate 14, two

bimetal strips

31, 32 are secured in such a manner that one free end of each is opposite one end of the rocker 3t} and one ball valve. At their free ends, the two

bimetal strips

31, 32 each carry a

screw stud

33 or 34, which can be screwed into a thread provided in the bimetal and which presses downwards on the corresponding ball valve and can thus release the valve passage concerned. Each of the

screw studs

33, 34 projects upwards through an aperture in the associated arm of the rocker and each is provided, at its upper end, with a

screw head

35 or 36, which can rest on the rocker 30. The two

bimetal strips

31, 32 are arranged in such a manner that they bend in opposite directions, that is to say, during heating, the bimetal strip 31 bends downwards towards the valve 21 and the bimetal strip 32 bends upwards towards the rocker 36; the bending takes place in the reverse direction during cooling. The deflection of a bimetal strip in the direction of the associated ball valve, that is to say of the bimetal strip 31 during heating and of the bimetal strip 32 during cooling, is limited in each case by the

corresponding screw head

35 or 36. In this end position, the bimetal strips run substantially parallel to the rocker arms and the

screw heads

35 and 36 bear with pressure against the ends of the rocker arms. Leaf springs 37, 38 on the under side of the plate 14 each urge their associated valve ball 21 or 22 into the corresponding valve seating while stops 39 and 40 respectively each prevents the associated valve ball from being pushed too far out and falling out. The push rod 20 of the diaphragm pressure member 17 presses on the right-hand rocker arm, the bimetal strip 32 of which is in operation during cooling. A compression spring 41 which serves as a counteracting force, presses on the lefthand rocker arm, the bimetal strip 31 of which is in operation during heating.

The drawing shows the regulating valve during heating. The two hal-l valves 21, 22 of the control valve are at first closed. The pressure of the medium therefore rises in the chamber 9 and the setting diaphragm 7 closes the main valve 5. As a result of the throttling of the heating medium, the temperature to be controlled drops and the push rod 20 of the diaphragm pressure member 17 is lifted. As a result, the rocker 30 is inclined towards the left and the screw stud 33 urges the ball valve 21 downwards so that theassociated valve passage is opened. The pressure in the chamber 9 therefore decreases and the main valve opens under the counter pressure of the restoring diaphragm 24. If the temperature to be controlled rises, the diaphragm pressure member 17 expands and the push rod 20 urges the right-hand arm of the rocker downwards as a result of which the lefthand arm thereof is raised accordingly, so that the ball 21 again closes its valve passage.

On changing over from heating to cooling, that is to say within a temperature range of the heating or cooling medium lying, for example between 28 to 29 C. and 21 to 22 C., the bimetal strip 31 bends towards the rocker 30 and the bimetal strip 32 stretches. As a result, the right-hand end of the rocker 30 is lowered and the screw stud 34 urges the valve ball 22 downwards so that the associated valve passage is opened. As a result, the pressure in the chamber 9 decreases and the main valve 5 opens so that the cooling medium can now flow through. If thetemperature to be controlled drops to the set desired value, the push rod 20 is raised and so, too, is the right-hand end of the rocker 30, as a result of which the valve ball 22 closes the associated valve passage and so The control valve according to the invention has the advantage that the distances between the

screw studs

33, 34 and the associated valve balls 21, 22 and the distance between the

screw heads

35, 36 and the rocker 30 can be easily and accurately adjusted. The simple bimetal strips provided for the changeover to heating or cooling comprise a deflection of their free ends which permits control in a temperature range of about 6 to 8 C.

he invention in its broader aspect is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

1. In a thermostatic, heat exchanger regulator valve for controlling the flow of a liquid medium during heating and cooling functions comprising a diaphragm pressure member and hydraulic servo means including a control valve for controlling the flow of said liquid medium, said control valve being controlled according to the pressure exerted by said diaphragm pressure member, means for improving said control valve comprising a two-armed rocker, Said rocker being urged in one direction by said diaphragm pressure member and in the opposite direction by a compression spring, two bimetal strips carried by said rocker, said strips having free ends lying respectively under said arms of said rocker and being adapted to bend in opposite directions relative to their respective arms in response to a particular temperature condition of said liquid medium, a pair of throttle members each comprising a ball valve, said throttle members being disposed respectively below said arms of said rocker and said free ends of said strips, leaf spring means adjacent said ball valves for urging said Valves into the closed position, each of said throttle members being located to control the actuation of said control valve and each being controlled according to the position of the associated strip whereby a change in temperature during heating functions causes one of said strips to actuate the associated throttle member to thereby actuate said control valve while the other said strip moves away from its associated throttle member, whereas a change in temperature during cooling functions causes said other strip to actuate its associated throttle member to thereby actuate said control valve, while the first one of said strips moves away from its associated throttle member.

2. A regulating valve as claimed in claim 1, wherein each of the arms of said rocker includes means defining an aperture in the end thereof, each of said bimetal strips carries, at its free end, a screw stud which is perpendicular thereto and which can be screwed into the bimetal strip, one end of the screw stud cooperating with the associated ball valve, the other end projecting through the aperture provided at the end of one of said rocker arms, said projecting end carrying a screw head which is adapted to limit the deflection ofthe bimetal strip in relation to the rocker by bearing against the latter.

3. A regulating valve as claimed in claim 1, characterized in that said rocker is mounted on pivot bearings.

References Cited in the file of this patent UNITED STATES PATENTS 1,270,438 Roesch June 25, 1918 2,309,848 King Feb. 2, 1943 2,805,025 Dillrnan Sept. 3, 1957