US3476130A - Fuel valves with safety latching means - Google Patents

Description

Nov. 4, 1969 c. s. J. KINGMA FUEL VALVES WITH SAFETY LATCHING MEANS Filed Jan. 24, 1966 Fig.

INVENTOR. CORNELIS S. J. KINGMA ATTORNEY United States Patent 3,476,130 FUEL VALVES WITH SAFETY LATCHING MEANS Cornelis S. .I. Kingma, Emmen, Netherlands, assignor to Honeywell G.m.b.H., Frankfurt-Main, Germany, a corporation of Germany Filed Jan. 24, 1966, Ser. No. 522,615 (llaims priority, application Germany, Mar. 27, 1965, H 55,613; May 15, 1965, H 56,042 Int. Cl. FZSd /16; F16k 51/00; F23q 9/08 US. Cl. 137-66 5 2 Claims ABSTRACT OF THE DISCLOSURE A fuel valve including a rotatable plug valve and a thermocouple operated safety valve in series flow relationship and having a latch cooperating with the plug valve so that when the plug valve is returned from an on position to a position between the on and off positions but wherein the fuel flow may be insufficient to support combustion at a burner controlled by the valve and thereby cause the flame at such burner to be extinguished, it cannot again be turned toward the on position until the safety valve closes and thereby disables the latch.

This invention relates to fuel valves and more specifically to those fuel valves having a manually operable control valve and a safety valve which must be manually opened and then is held open by a flame responsive device so long as a flame exists at a burner to which the flow of fuel is controlled by the valve. Specifically, the invention relates to valves as described above wherein there is provided means for restricting the movement of the manual valve when the safety valve is open.

In controlling the flow of fuel, such as gas, to burners for furnaces and appliances, it is customary to utilize a valve having a manual control valve and a safety valve which will automatically shut off the flow of fuel should the flame be extinguished. Various types of manual valves and safety valves have been devised in the past and are well known in the art. The safety valves utilize various types of operators such as bimetals, expansible rods and the like, but the most popular is the type utilizing a thermoelectric generator heated by the flame and energizing an electromagnet which is not strong enough to open the safety valve but of suflicient strength to hold it open when it is manually opened. In all of these types of flame-sensing operators for safety valves there is a certain amount of heat inertia so that the safety valve does not close immediately upon the flame being extinguished. Due to this phenomena, it has been possible for a dangerous condition to be inadvertently created by establishing a flame and manually setting the safety valve, and then moving the manual valve to a position so that the flame is extinguished but reopening it before the flame-responsive operator for the safety valve has cooled sufficiently to close the safety valve. When this occurred, gas was allowed to flow to the burner without the presence-of a flame and, in some instances, suflicient gas accumulated at the burner to create a hazardous condition without the operator being aware of what had happened.

The possibility of such a condition being inadvertently brought about has been recognized in the past. For example, the Putz et al. Patent 3,099,994 discloses an arrangement wherein a control including a manual ga valve and a thermocouple safety valve is provided with a latching arrangement which precludes movement of the manual valve from its closed position unless the safety valve is closed. The structure disclosed in the Putz et al. patent is utilized in connection with a manual valve of the type wherein a rotatable operator operates an axially movable disc-type valve. There appears to be no readily apparent "ice way of adapting the structure of Putz et al. to the more conventional rotatable plug or disc-type manual gas valve. In addition, the structure disclosed in Putz et al. is very complex, including a plurality of co-acting parts, several of which have odd shapes which would require rather delicate machining operations rendering the structure expensive to produce.

My invention is deemed to be an improvement over the disclosure of Putz et al. It provides a simple and easily manufactured latching arrangement which can be readily incorporated into most conventional fuel valves without substantial redesign of the valves or substantial retooling for their production. This latching arrangement precludes the manual valve from being reopened until the safety valve has been closed, should the manual valve be moved to a flame-extinguishing position after a flame has been established. The invention is particularly applicable to fuel valves utilizing a rotatable plug or disc-type valve with a rotatable manual operator but may be utilized in axially movable valves of the general type disclosed in Putz et al. so long as there is a rotatable portion of the valve and manual operator combination. A latching surface is provided which is rotatable with the previously mentioned rotatable portion of the manual valve-operator combination and extends generally parallel to the axis of rotation of this portion. The latching surface is disposed so that it traverses an arcuate path when the manual valve means is moved. A cooperating latching member is mounted for movement toward and away from the path of the latching surface, transverse to the axis of rotation thereof. A resilient means is provided for urging the latching member into the path of the latching surface and the latching member is operably connected to the safety valve and is moved thereby out of the path of the latching surface when the safety valve is closed.

Various objects and advantages of my invention will become apparent upon reading the following detailed description of certain preferred embodiments thereof wherein reference is made to the drawing.

In the drawing: FIGURE 1 is an elevational view, partially in cross section, disclosing a fuel valve utilizing my invention; FIGURE 2 is a fragmentary plan view disclosing the manual operator for the valve; FIGURE 3 is a fragmentary cross-sectional view taken generally along line 3-3 of FIGURE 1; FIGURE 3a is a fragmentary cross-sectional View generally similar to FIGURE 3 but disclosing a slightly modified form of the invention; FIG- URE 4 is an enlarged view of a latching member which forms part of the invention; FIGURE 5 is a top view of the latching member of FIGURE 4; FIGURE 6 is a front view of the latching member of FIGURES 4 and 5; FIG- URE 7 is an enlarged fragmentary view of a portion of the structure disclosed in FIGURE 3; FIGURE 8 is an enlarged fragmentary view of a portion of the structure disclosed in FIGURE 3a; and FIGURE 9 is a schematic representation of a programming arrangement for the manual valve.

Referring to FIGURE 1, reference numeral 10 generally designates a fuel control valve for controlling the flow of a fuel, such as gas, to a burner. Valve 10 includes a body or housing 11 which may take the form of a generally cup-shaped casting having an inlet 12. Preferably valve It) has a main outlet (not shown) which is adapted to be connected to a main burner 13 and a pilot outlet (not shown) which is adapted to be connected to a pilot burner 14. Valve 10 includes a manual valve-operator combination 15 and a safety valve 16 which are connected in series relationship to control the flow of gas through the valve. The particular form of the manual valve-operator combination is not critical but the manual valve must be movable between at least an on and an off position and, during movement between these positions, at least a portion of the valve-operator combination must rotate. Preferably the manual valve is a rotatable plug or disc but the invention may also be used in connection with axially movable disc-type valves if desired. The particular configuration of the safety valve is also not critical to the invention and, while various types of flame-responsive safety valves may be used, the conventional thermocouple type safety valve is preferred. I have chosen to disclose, by Way of example, a rotatable plug valve and thermocouple safety valve generally similar to that discolsed in the Walter F. Allingham Patent Number 3,236,252 assigned to the assignee of the present invention. Since the particular structure of the manual valve and operator and the safety valve are not critical, these devices will be described only briefly herein.

Valve body 11 may be cast with a tapered valve seat 17 for a rotatable plug valve 20 which has operably connected thereto a manual operator taking the form of a knob 21 disposed above the upper surface of body 11. Plug valve 20 has a central opening extending upwardly into it from the lower end thereof and connecting to a transverse port (not shown) which is adapted to connect into a passage in the valve body when the valve is rotated to a particular angular position. I have chosen to disclose the plug valve as being rotatable from an off position to pilot, high and low positions, as seen in FIGURE 3. The angular position of the plug valve may be indicated by providing a fixed mark 22 on the valve body to cooperate with appropriate indicia on knob 21. It is to be understood that it is not essential to the invention that this plurality of positions be provided for the plug valve, it being essential only that the valve have off and on positions. The term on position, as used herein, is intended to include a pilot position, One or more main burner on positions, or both.

Safety valve 16 includes a valve closure member 23 which is adapted to cooperate with the lower end of plug valve 20 to control the flow of fuel therethrough. Closure member 23 is operably connected to a stem 24 which extends up through the center of the plug valve and is connected to knob 21. A spring 25 urges closure member 23 downward away from the end of the plug valve and into engagement with one end of a lever 26 which is pivoted on a downwardly extending portion 27 of valve body 11, as by a pin 30. The other end of lever 26 is engaged by a plate 31 which is connected to the armature (not shown) of an electromagnetic unit 32 including a coil which is adapted to be energized by a thermocouple 33 disposed to be heated by a pilot burner 14. A spring 34 urges plate 31 downwardly and rotates lever 26 in a counter clockwise direction to close closure member 23 when the electromagnet in unit 32 is de-energized. When the magnet is energized, it has insufficient strength to draw the armature upward but can hold the armature upward against the force of spring 34 when the device is reset as by depressing knob 21. When the magnet in unit 32 is energized and holds plate 31 up, spring 25 holds closure member 23 away from the end of plug valve 20.

As indicated, the structure described thus far is old and forms no part of my invention. My invention lies in combining with the structure described above, a simple latching arrangement to preclude moving the manual valve from a substantially closed position to an open position when the safety valve is open. This is accomplished by providing on a rotatable portion of the manual valveoperator combination, a latching surface which cooperates with a latching member 41. Latching surface 40 may be formed on any rotatable portion of the manual valve-operator combination, and in the case of the plug valve and knob disclosed herein, may be either on the plug valve or the knob. However, I have chosen to form it on a peripheral wall of plug valve 20 near the bottom of the plug valve. Latching surface 40 may take the form of an indentation or depression such as shown in FIG- URES 1 and 3 or it may take the form of a generally 4 radially extending cam-like protrusion 40a as disclosed in FIGURE 3a.

Latching member 41 is a bell-crank type member having a generally cylindrical portion 41a which is rotatably mounted on pin 30. Extending from cylindrical portion 41a are a pair of spaced, parallel, finger-like members 41b which are adapted to engage the upper portion of lever 26 adjacent the point where it engages closure member 23 and to straddle a neck portion 23a of member 23. Extending from cylindrical portion 41a, generally per pendicular to fingers 41b, is an arm 41c which has a transverse latching portion 41d extending in the direction of fingers 41b and generally parallel thereto. It will be obvious that as the plug valve is rotated the latching surface 40 will traverse an arcuate path and the latching member is so constructed and disposed that portion 41d thereof is rotatable into and out of this path. Latching member 41 is resiliently urged in a clockwise direction by an appropriate biasing means such as a spring 42 which may be a generally U shaped element encircling cylindrical portion 41a and having one end abutting a fixed abutment 43 on housing 11 and the other end bent so as to have a portion 42a disposed in a slot 41e formed in arm 41c of the latching member. If desired, a groove 41 may be formed in cylindrical portion 41a to aid in positioning spring 42. Latching member 41 is constructed so that whenever the safety valve is open, spring 42 urges latching portion 41d into engagement with the peripheral wall of plug valve 20 so that when the plug valve is rotated to a position wherein latching surface 40 is adjacent to the latching member, portion 41d will drop into the depression or be intersected by the cam-like protrusion if the arrangement of FIGURE 3a is utilized.

While it is desirable to preclude turning the valve to an on position when the flame has been extinguished and the safety valve is open, it is essential that the manual valve be rotatable from an on to an off position regardless of the position of the safety valve. This is facilitated by forming the latching surface 40 with an abutment portion 40a which engages latching portion 41d of the latching member when the plug valve is rotated in a counter-clockwise direction (as seen in FIGURE 2) and with a sloping surface 40b which engages portion 41d of the latching member when the plug valve is rotated in a clockwise direction. Sloping surface 40b does not preclude rotation of the plug valve but simply cams the latching member in a counter-clockwise direction, in opposition to spring 42, and allows the plug valve to rotate with respect to it. If the cam-like protrusion (disclosed in FIGURE 3a) is utilized, a similar provision can be made by providing an abutting surface 140a which abuts substantially flatly against the latching member when the plug valve is rotated in a counter-clockwise direction and a sloping cam surface 14012 which simply urges the latching member outwardly away from the plug valve when the valve is rotated in a clockwise direction.

The location of the latching surface 40 may be such that the,plug valve is latched, and thereby prevented from being rotated towards on, only when the valve is turned all the way to the off position. However, generaly a flame at the pilot burner will be extinguished before the valve is turned all the way to the off position. Therefore, it may be desirable to locate latching surface 40 at a point intermediate the off and pilot positions. By way of example, the latching surface has been located in the illustrative embodiment so that the valve is latched at a position about 60 from the off position. Thus, any time that the valve is in a pilot or on position and a flame exists at burners 14 and/ or 13, and the plug valve is then rotated backwards a distance sufficiently beyond the pilot position, toward the off position, so that the flame might be extinguished at pilot burner 14, the latch becomes effective to preclude turning the valve back toward the on position until the safety valve has dropped out.

In valves of the type described herein, it is customary to provide a programming arrangement so that the valve can be operated only through a safe lighting sequence. This is generally provided by a programming track or groove, in either a portion of the valve body or in the knob, and a cooperating pin in the other one of the two members. By way of example, one such programming arrangement is disclosed in FIGURE 9 where a pin 50, which is attached to knob 21, operates in a programming groove 51 which is a portion of the body. This structure is conventional and is not disclosed in FIGURE 1 and it will be understood that the disclosure of FiGURE 9 is schematic and for purposes of explanation only. In a conventional programming arrangement, it may be possible to depress knob 21 to open the safety valve any time when the plug valve is in the off or pilot position. It will be understood that knob 21 is biased upward by a means not shown in this disclosure. Thus, in the off position, pin 50 occupies the position shown in dashed lines and indicated at 50a in FIGURE 9. To rotate to the pilot position, the knob must be depressed sufficiently to move the pin under a downwardly extending portion of the area surrounding programming slot 51. Thus, the programming slot would follow the dashed portion shown in FIGURE 9. The knob could be depressed to move pin 50 to a position 50b and then rotated to a position 50c to supply gas to the pilot burner which could then be ignited. The safety valve would be held open until the thermocouple provides suflicient current to energize the electromagnet in unit 32 to hold the safety valve. At this time the knob can be released to allow the pin to move upward to a position 50d where it may be rotated to positions 50c and 50 for high or low operation of the main valve as desired. However, with the latching structure provided by my invention, the Valve cannot be rotated toward the on position if the safety valve is open. Thus, in order to get the plug valve to the pilot position, it is necessary to modify the programming slot so that knob 21 cannot be depressed until the plug valve has been rotated past the position where the latching surface and the latching member coact. This position is indicated by the solid line position of pin 50 in FIGURE 9.

The operation of the structure will be apparent from the foregoing description. When it is desired to ignite burner 14, knob 21 is depressed slightly and rotated to the pilot position wherein it is depressed to position 50c and a flame established at the pilot burner. When the thermocouple unit has energized the magnet in unit 32, the safety valve remains open and the plug valve may be rotated to either of the on positions. It is possible to turn the plug valve back to the pilot position, extinguishing the main burner but maintaining a flame at the pilot burner, without bringing the latching apparatus into operation. However, should the plug valve be rotated backwards beyond the pilot position, toward the off position sufliciently so that the flame might be extinguished at pilot burner 14, it brings latching surface 40 into cooperative engagement with latching member 41, and the cooperation of the latching surface and latching member will preclude rotation of the plug valve toward the pilot and on positions, so long as the safety valve is open. However, the plug valve can be rotated back to the off position. Once the safety valve has closed, lever 26 pivots latching member 41 to a position wherein latching surface 41b is out of the path of latching surface 40. The valve can then be operated again in the manner described above.

I claim:

1. A fuel valve having manual valve means including a closure member-manual operator combination movable between off and on positions and including a portion which is rotated during such movement, the closure member being constructed so that it progressively closes a fuel passage as the manual valve means is moved from the on toward the off position, a safety valve which must be manually opened and which is then held open in the presence of flame by a flame responsive device, and latch means operable to restrict movement of the manual valve means when the safety valve is held open by the flame responsive device, characterized by: a latching surface extending generally parallel to the axis of rotation of said rotatable portion and rotatable with the rotatable portion of said manual valve means, said latching; surface traversing an arcuate path upon movement of the manual valve means; a cooperating latching member movable transversely to the axis of rotation of said rotatable portion; means mounting laid latching member for movement into and out of the path of said latching surface; means resiliently urging said latching member into the path of said latching surface; said latching surface and said latching member being disposed so that they engage when the closure member is in a predetermined position between said off and on positions and wherein the closure member has closed the fuel passage to the extent that it may allow insufficient fuel flow therethrough to support combustion at a burner controlled by the valve; and means operably associated with said latching member and said safety valve for moving said latching member out of the path of said latching surface when said safety valve is closed.

2. The fuel valve of claim 1 wherein the manual valve closure member is a rotatable plug valve, and wherein said latching surface comprises a recess in the peripheral surface of the plug and disposed so that a latching portion of said latching member extends thereinto only when said plug is in said predetermined angular position, between said off and said on positions, and said safety valve is open.

References Cited UNITED STATES PATENTS 3,099,994 8/1963 Putz et al. 13766 3,236,252 2/1966 Allingham l3766 3,303,866 2/1967 Ray 431-54 WILLIAM F. ODEA, Primary Examiner R. GERARD, Assistant Examiner US. Cl. X.R. 25 l287; 43 l54

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