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(11) | EP 0 159 393 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Gas valve assembly |
| (57) A gas valve assembly has a safety valve (13) and a electromagnetic controlled valve
(14) connected in series. A control knob (42) provides for manual control of the safety
valve (13) and for locking the electromagnetically controlled valve (14) in closed
position. The manual control knob, when in the OFF and PILOT positions, causes a stop
member (61) to be moved against the movable core member (23) of the electromagnetic
operator to hold the electromagnetic controlled valve closed. |
[0001] Known gas valve assemblies have safety valves and manually controlled valves connected in series with a thermostatically controlled valve, whether it be a pressure operator or an electromechanically operated valve. The manual control valves have generally been of the plug type which are very expensive to manufacture and the valve assembly is quite bulky. Additionally, with the ad- 'vent of electronic ignition and the need for more safety with gas valve assemblies, it was recommended that a dual valve be used for the automatic control to ensure that when the automatic control is in the off condition, positive shut off is assured. Such dual valve requirement additionally adds to the cost of the gas valve assembly. A gas valve assembly of this type is shown in the Instruction Sheet #60-2019-4, published July 1979 by Honeywell Inc.
[0002] The present invention is concerned with a gas valve assembly according to the general portion of Claim 1 having a safety valve and an automatically controlled valve connected in series. It is the main object of the present invention to improve this kind of assembly and to provide a less complex mechanical structure for such an assembly without impairing its reliability. It should be easily operable without leading to false operation. These and other objects are achieved by the invention as characterized in Claim 1. A single manual operator or knob controls the operation of the safety valve and of the automatically controlled valve. Specifically, when the manual control is in a first position ("pilot"), the safety valve can be controlled and the electromechanically controlled automatic valve is rendered inoperative. When the manual control is in a second position ('on"), the electromechanically controlled valve can be operated. The plunger of the automatically controlled valve is moved by the energization of an electric coil in response to the automatic control signal. When the manual control is in the first position ("pilot"), a pin is positioned against the plunger to limit its movement and maintain the automatically controlled valve in an off position. Further features of the new valve assembly are described in the subclaims and will be explained in more detail with reference to the accompanying drawings, wherein:
Figure 1 is a side cutaway view of the gas valve assembly;
Figure 2 is a top view showing the positions of the manual control knob;
Figure 3 is a more specific cutaway view of a portion of the valve shown in Figure 1; and
Figures 4 and 5 disclose another embodiment of the gas valve assembly.
[0003] Referring to Figure 1, a gas valve assembly has a body or housing 10 with an inlet opening 11 adapted to be connected to a source of gas under pressure and an outlet opening 12 adapted to be connected to a gas burning appliance such as a furnace or boiler. The assembly has three valves, a safety valve 13, an electromagnetically or actuator controlled valve 14, and a pressure operated or actuator controlled valve 15 connected in series between inlet 11 and outlet 12.
[0004] Safety valve 13 comprises a valve closure member 20 connected to a power unit or actuator 21 of a conventional flame proving means or thermocouple of the type described in US-A 2,881,779 and 3,290,178 for holding the safety valve 13 in an open position once the valve is manually opened and a pilot flame is present at a thermocouple. When actuator 21 is no longer energized by the thermocouple, the safety valve 13 will close. Valve 14 comprises a valve closure member 22 connected to a shaft, plunger or core member 23 of an electromagnetic actuator 24. Closure member 22 and plunger 23 are biased downward against a valve opening to close valve 14 when electromagnetic coil 25 is not energized over a control circuit including conductors 30 and 31. Valve 15 is a conventional pressure operated valve which might be controlled from a pressure regulator and an electrically controlled pilot valve of the type shown in US-A 3,354,901.
[0005] A safety valve cocking mechanism and pilot valve operator or shaft 32 is connected to a button 33 and is spring biased upward by spring 34. A pilot valve 35 has a valve closure member 40 attached to an end of shaft 32 for closing the pilot valve when in its upward extreme position. In the position shown, pilot valve 35 is open and gas is allowed to pass from inlet 11 to a pilot burner by a pipe or tube 41. A manual control knob 42 is supported on body 10 by body portion 43 so that the knob rotates on an axis in line with plunger 23 of electromagnetic actuator 24.
[0006] Knob 42 has a cam surface 45 attached thereto which has a wide portion at 44 and a thin portion at 50. When knob 42 is rotated, depending upon the thickness of the cam 45, button 33 is moved up and down to control the position of closure member 40. As shown, knob 42 is in the on position and pilot valve 35 is held open by cam 45.
[0007] Knob 42, as shown in Figure 2, has a pointing portion 51 and an opposite wide portion 52. When the knob is pointed in the "pilot" position, portions 51 and 52 are in line with openings 53 and 54, respectively, in cover or body 43. In this position, knob 42 can be moved or manually pushed downward against button 33 to move shaft 32 and closure member 40 against closure member 20 of the safety valve to open safety valve 13.
[0008] Referring to Figure 3, knob 42 contains an inner sleeve or bushing 60 which is splined or guided by knob 42 and attached to a pin 61. Pin 61 is guided in a sleeve 62 which is crimped at its upper end forming an abutment for a spring 63 which biases pin 61 and bushing 60 downward. Bushing 60 has a pair of feet or cam riders 64 and 65 which ride on cam member 70. This cam member is attached to housing 10 by means of the support of the electromagnetic coil.
[0009] As shown in Figure 1, cam member 70 has a cam surface 71 supporting bushing 60 which is splined at 72 and 73 to the knob 42, as shown in both Figures 2 and 3. The rotation of knob 42 rotates bushing 60 and cam riders 64 and 65 follow cam surface 71 to raise or lower pin 61 between the two positions shown in Figure 3. In the lower dotted position, pin 61 holds plunger 23 in a position to maintain the valve 14 closed regardless of the energization of actuator 24.
[0010] With a source of gas under pressure connected to inlet 11 with the gas valve assembly in the position shown in Figure 1 gas flows to pilot the burner through pilot valve 35. The safety valve 13 is open and closure member 20 is being held in the position shown by the flame proving apparatus or hot thermocouple connected to actuator 21. To obtain this particular operation, knob 42 had been turned to the "pilot" position so that the pointer portion 51 coincided with the opening 53 in cover or body 43 and knob 42 had been manually pushed downward. Cam surface 45 engaged button 33 to push shaft 32 downward so that the end of the shaft and closure member 40 engaged the closure member 20 of the safety valve to open the safety valve. Gas then flowed to the pilot burner and heated the thermocouple until its current flowing through actuator 21 was strong enough to hold the safety valve open. In that "pilot" position, pin 61 is lowered to the dotted position as shown in Figure 3 so that the electromagnetic operated valve 14 could not be opened. This prevents gas flow to a main burner of the furnace.
[0011] Once the pilot burner flame was ignited, whether by manual means or spark ignition, and the thermocouple was hot, safety valve 13 would stay open. Knob 42 is then released and turned to the "on" position as shown in Figures 1 and 2. In this position, bushing 60 is raised as the members 64 and 65 are riding on the high portion of the cam 71. Pin 61 is then in the position as shown to allow for movement of the plunger 23 when the electromagnetic actuator 24 is energized. Gas would then flow to the outlet assuming that the second of the dual valve assembly or control valve 15 was also opened.
[0012] In the off position with pointer portion 51 of knob 42 pointed to "off" as shown in Figure 2, the narrow portion 50 of cam 45 is adjacent or in line with button 33. Shaft 32 can move farther up than is shown to close pilot valve 35. This would result in the pilot burner being extinguished and the thermocouple cooling off to close safety valve 13.
[0013] Referring to Figures 4 and 5, another embodiment of the present invention is shown by modifying the upper portions of the gas valve assembly of Figures 1, 2 and 3. In the embodiment of Figures 4 and 5, the reset button 33' is separately operated rather than being operated by the manual control knob 42' as done with the above described embodiment.
[0014] In Figure 5, knob 42' is shown attached to stop member 61'. Both the stop member and knob 42' are biased downward by spring 63'. Knob 42' has cam 45' which cooperates with the pilot reset button 33'; however, in this embodiment, cam 45' is used to prevent the operation of the reset button 33' when the manual control knob 42' is in any position but the pilot position. Specifically, cam 45' as shown in Figure 4 has opening 70'which falls in line with the reset button 33' when the knob 42' is in the pilot position. The notch allows movement of the button 33' downward by manual operation_to set the safety valve 13 as described above. Cam 45' has a thicker portion 71'which falls in line with the button 33' when the manual control knob is in "off" position to raise the button 33' and thus close the pilot valve 35.
[0015] Another cam 72'is attached to the control knob 42' as shown in Figures 4 and 5. Cam 72'is biased downward on -the upper surface 43' of the body and controls the raising and lowering of pin 61'. The upper surface 43' has a higher portion at 73'and 74'so that when the manual control knob is in the "on" position, cam 72'will lie on the higher portions 73'and 74'to raise the knob and thus pin 61' to allow the automatic valve to operate.
[0016] With the source of gas under pressure connected to the inlet of the valve assembly shown in Figure 1, the operation of the second embodiment shown in Figures 4 and 5 will be similarly explained. When the manual control knob 42' is in the off position, cam 45' is positioned so the thicker portion 71'lies adjacent button 33' and the button is raised to an even higher position to close the pilot valve 35.
[0017] Upon the desire to operate the appliance attached to the gas valve assembly, knob 42' is turned to the "pilot" position, and in this position, opening 70'coincides with the button 33 and not only is the pilot valve 35 open to allow gas to go to the pilot, but button 33' can be pushed downward to operate the safety valve 13 and activate power unit 21. As soon as the pilot flame is ignited and the flame proving means energizes power unit 21, button 33 can be released and returns to a position wherein cam 45' maintains the button 33 and also pilot valve open.
[0018] Thereafter, manual control button 42' can be turned to the "on" position. In the "on" position cam 45' ensures that button 33 can no longer be operated as the pilot is in operation and the energy proving means or thermocouple connected to the power unit is heated. When knob 42' is turned to the "on" position, cam 72' results in the movement of knob 42' and pin 61' slightly upward to release the automatic control valve plunger 23 and allow for automatic control.
a first valve (13) and a second valve (14) connected in series between an inlet (11) and an outlet (12) of a valve body (10);
an actuator (24) connected to the closure member (22) of the second valve for moving said closure member from a closed position to an open position upon energization of the actuator;
a manual control knob (42) mounted on said body (10), characterized by first means (32) connecting said control knob (42) for operating the closure member (20) of the first valve (13) to an open position when said control knob is in a first position (53, PILOT), and
second means (61, 61') connecting said control knob (42) to the closure member (22) of the second valve (14) for holding said second valve in a closed position when said control knob (42) is in said first position and allowing operation of said second valve to an open position by its actuator (24) when said control knob (42) is in a second position (51, ON).
upon said knob (42) being in said second position (53, PILOT) said button opens said pilot valve (35).
a) a first valve (13) which is a safety valve whose closure member (20) can be opened manually and afterwards is kept in the open position by a power unit connected to a thermocouple;
b) a solenoid operated second valve (14) whose closure member (22) is spring biased in closing direction and can be opened by the magnetic force acting upon a plunger (23) which is moveable within the coil of the solenoid when supplied with current; characterized in that
c) a shaft (32) for manually opening the first valve (13) and the plunger (23) carrying the closure member (22) of the second valve (14) extend in parallel;
d) the axis of rotation of the control knob (42) is aligned with the plunger (23);
e) a push button (33) fixed to one end of the shaft (32) engages a cam surface (45) provided at the control knob (42);
f) the control knob (42) is moveable in axial direction for opening the first valve (13) if the control knob (42) is turned into the first angular position (53, PILOT);
g) a bushing (60) carries a pin (61) which is aligned with the plunger (23);
h) the bushing (60) together with the pin (61) is mechanically coupled for rotation with the control knob (42);
i) the bushing (60) is guided moveably in axial direction within the control knob (42) and is_spring biased in the direction to the plunger (23);
j) cam riders (64, 65) of the bushing (60) engage a stationary cam surface (71) such that in the first position (53, PILOT) of control knob (42) the pin (61) is pressed by the biasing spring (63) against the plunger (23) and therewith prevents opening of the second valve (14);
k) in the second position (51, ON) of the control knob (42) the cam surface (71) lifts the pin (61) off the plunger (23) (Figure 1 - 3).
a) a first valve (13) which is a safety valve whose closure member (20) can be opened manually and afterwards is kept in the open position by a power unit connected to a thermocouple;
b) a solenoid operated second valve (14) whose closure member (22) is spring biased in closing direction and can be opened by the magnetic force acting upon a plunger (23) which is moveable within the coil of the solenoid when supplied with current; characterized in that
c) a shaft (32) for manually opening the first valve (13) and the plunger (23) carrying the closure member (22) of the second valve (14) extend in parallel;
d) the axis of rotation of the control knob (42) is aligned with the plunger (23);
1) a manually operable push button (33') is fixed to one end of said shaft (32) for opening the first valve (13) ;
m) the control knob (42') comprises a first cam (45') cooperating with the push button (33') to prevent pushing of the button unless knob (42') is in the first position (PILOT);
n) the control knob (42') carries a pin (61') which is aligned with the plunger (23);
o) the control knob (42') together with the pin (61') are guided moveably in axial direction and are spring biased in the direction to the plunger (23);
p) the control knob (42') comprises a second cam (72') engaging a stationary cam surface (43', 73', 74') such that the pin (61') is lifted off the plunger (23) if the knob (42') is in the second angular position (ON) (Figure 4, 5).