Abstract:
A single coil, two operator controller for simultaneously actuating two spaced apart magnetically responsive operators has a bar extending between the spaced apart operators, and a coil on the bar, between the operators for creating a magnetic field for moving the magnetically responsive operators. The single coil, two operated controller is particularly suited for operating a gas valve.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to a single coil, two operator controller, and in particular to a single coil, two operator controller for gas valves, and gas valves incorporating such a controller. 
   There are a number of instances where it is desirable to simultaneously operate two devices. For example, operating the main valve and the redundant value in a conventional gas valve. This is most commonly achieved by simultaneously operating two controllers, for example, two solenoids. Even if it were possible to operate the members with a single coil, the size and expense of a single coil to operate two operators would result in little, if any, savings. 
   SUMMARY OF THE INVENTION 
   The present invention relates to a single coil, two operator controller for simultaneously actuating two spaced apart magnetically responsive operators. The controller is particularly useful in conventional gas valves having a main and redundant valves, but which is applicable to other systems where it is desirable to simultaneously or nearly simultaneously operate two members. Generally, the controller comprises a bar extending between the spaced apart operators and a coil on the bar between the operators for creating a magnetic field for moving the magnetically responsive operators. There is preferably also a plate extending between the spaced apart operators to form a substantially closed flux path through the bar, the plate, and the two controllers, to facilitate the actuation of the magnetically responsive operators. 
   In the preferred embodiment, the single coil comprises first and second windings, and there is a return between the first and second coils, extending between the bar and the plate, forming two separate closed magnetic flux paths, each containing one of the operators. This allows a reduction in the overall size of the coil needed to actuate the two operators, resulting in reduction in material used and in cost of the controller. These and other features and advantages will be apparent in the detailed description of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a longitudinal cross sectional view of a single coil, two operator controller of the present invention, shown as it would be incorporated into a conventional two-valve gas valve; 
       FIG. 2  is an enlarged longitudinal cross sectional view of the single coil, two operator controller of the present invention; 
       FIG. 3  is an enlarged longitudinal cross section view of the single coil, two operator controller of the present inventions, with its cover removed; 
       FIG. 4A  is a side elevation view of the controller with the cover removed, showing the operations in position when the valve is closed; 
       FIG. 4B  is a side elevation view of the controller with the cover removed, showing the operations in position when the valve is open; 
       FIG. 5  is a side elevation view of a gas valve incorporating a single coil, two operator controller of the present invention; 
       FIG. 6  is a top plan view of the gas valve. 
   

   Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
   DETAILED DESCRIPTION OF THE INVENTION 
   A single coil, two operator controller of the present invention, indicated generally as  20 , is shown in  FIG. 1  as it would be mounted on a conventional gas valve  24 . The conventional gas valve  24  includes an inlet  26  and an outlet  28 , a main valve  30  and an auxiliary valve  32 , and a pressure regulator  34 . When both the main valve  30  and the auxiliary valve  32  are open, the gas valve  22  provides gas from the inlet  26  to the outlet  28  at a pressure determined at least in part by the regulator  34 . When either the main valve  30  or the auxiliary valve  32  is closed, gas does not flow through the gas valve  22 . 
   The main valve  30  has a magnetically responsive operator  36  that reciprocates inside a closed-end sleeve  38 . The sleeve  38  projects upwardly from the top surface of the gas valve  22 . The reciprocating movement of the operator  36  opens and closes the main valve  30 . Similarly, the auxiliary valve  32  has a magnetically responsive operator  40  that reciprocates inside a closed-end sleeve  42 . The sleeve  42  projects upwardly from the top surface of the gas valve  22 . The reciprocating movement of the operator  36  opens and closes the auxiliary valve  32 . 
   The controller  20  comprises a bar  44  extending between the spaced apart operators  36  and  40 . The underside of the bar  44  has recesses  46  and  48  for receiving the closed ends of the sleeves  38  and  42 . 
   There is a coil  50  on the bar  44  of a flux-conducting material. The coil  50  comprises first and second winding sections  52  and  54  wound on a plastic core  56 . The plastic core  56  has a first bobbin section  58  for the first winding section  52  and a second bobbin section  60  for the second winding section  54 . As shown in the drawings and described herein, the first and second winding sections are unequal in size, although the sizes of the two winding sections depends upon their application, and thus, their relative sizes may differ in different applications. 
   A plate  62  extends substantially between the spaced apart operators  36  and  40 . In the preferred embodiment, the plate  62  has openings  64  and  66  through which the sleeves  38  and  42  extend. The operators  36  and  40  are sized and positioned so that when the coil  50  is not energized, the operators form gaps G 1  and G 2  between the bar  44  and the plate  62 , and when the coil is energized, the magnetic force moves the operators to close the gaps G 1  and G 2  and form a substantially continuous flux path through bar  44 , operator  36 , plate  62 , and operator  38 . The movement of the operators  36  and  40  to close the gaps G 1  and G 2  opens the main and auxiliary valves  30  and  32 . There are small gaps between the plate  62  and the actuators and between the bar  44  and the actuators, but these are generally negligible. 
   In accordance with the preferred embodiment of this invention, a return  68 , positioned between the first and second winding sections  52  and  54 , extends between the bar  44  and the plate  62 , providing an alternate flux path so that when the coil  50  is energized, two parallel paths L 1  and L 2  are formed, the first, L 1 , comprising operator  36 , a portion of the plate  62 , and the portion of the bar  44  over which the first winding section  52  lies, and the second, L 2 , comprising the return  68 . In the preferred embodiment, the return  68  is a U-shaped member, arranged so that the bottom of the “U” extends over the bar  44 , and the legs of the “U” are adjacent the plate, preferably fitting into slots  70  in the plate. The core  56  creates a small gap between the inside of the bottom of the “U” of the return, and the bar  44 . A portion of the core  56  could be cut away to between the bobbin section to reduce or eliminate the gap. 
   As shown in  FIG. 3 , rather than a single path L with two gaps, G 1  and G 2 , the return  64  provides two paths, L 1  and L 2 , to substantially eliminate gap g 1 . Thus, the total size of the coil (in terms of number of turns) can be reduced. For one particular configuration of gas valve, it was determined that a single coil operating in a single path L would need 3600 turns to actuate the operators, and close the gaps G 1  and G 2 , but that a single coil with two paths, L 1  and L 2 , would need only 2700 turns in order to actuate the actuators and close the gaps G 1  and G 2 . 
   In the particular gas valve design shown and described herein, the force required to operate the primary valve is substantially less than the force required to operate the auxiliary valve. Moreover, the gap G 1  that defines the travel of operator  36  (about 0.05 inches) is approximately ⅓ of the gap G 2  that defines the travel of the operator  50  (about 0.150 inches). Since path L 2  substantially shunts gap G 1  and path L 1 , the total gap is reduced by gap G 1  (about 25 percent) such that the second winding section needs 2700 turns to actuate the operator  40  to close the gap G 2 . 
   In operation, when the coil  50  is energized, the magnetic force created by the second winding section  54  in path L 2  moves the operator  40 , closing the gap G 2  and opening the auxiliary valve. The magnetic force created by the second winding, particularly after the second gap G 2  is closed, also moves the operator  36 , closing the gap G 1  and opening the primary valve. The first winding  52  is not necessary to actuate the much lower force operator  36 , but improves its actuation with only 200 turns. 
   The controller  20  is preferably enclosed in a housing  71 . The controller  20  preferably also includes a switch  74  for selectively powering the coil  50  to open and close the gas valve. The switch  74  includes a switch member  76  pivotally mounted in the housing  72  to operate between the first and second positions. The switch member  76  is resiliently biased with an overcenter spring mechanism to retain the switch in its position until it is affirmatively operated to the other position. When the gas valve  22  is connected to a gas line, and the controller connected to a system via contacts  78  and  80 , the controller  20  opens the gas valve  22  in response to applied power from the system when switch  74  is “on,” but does not open the gas valve in response to applied power from the system when the switch is “off.” 
   The controller  20  thus economically operates both the main valve  30  and the auxiliary valve  32  of the gas valve with a single coil, and in the preferred embodiment that includes the return  68 , with a single coil with minimal number of turns, thus reducing material usage and cost.