Abstract:
A pressure regulator ( 10 ) includes a changeover regulator ( 12 ) with plural inlets ( 16, 18 ). Inside the regulator, each inlet has a closure member ( 62 ) connected to a diaphragm ( 100 ) for control of the closure members ( 62 ) in response to pressure inside the regulator ( 12 ). Biasing members ( 56 ) are stabilized in position by either an apertured plate ( 102 ), a cup ( 104 ) or both. A changeover handle ( 19 ) depresses one spring ( 56 ) or the other to bias one closure member ( 62 ) open to admit gas from the associated inlet ( 16  or  18 ).

Description:
BACKGROUND OF INVENTION 
   The present invention relates to regulators for gas systems and, more particularly, to an automatic changeover two-stage LP gas regulator. 
   Automatic changeover two-stage LP gas regulators are widely known and used to provide gas to selected appliances at a stepped-down pressure. Automatic changeover regulators, such as the Marshall Gas Controls Model 250, typically include a high-pressure changeover regulator that includes at least one inlet for receiving gas from a pressurized container, reduces the gas pressure to a first predetermined level, and transmits that gas to a second, low-pressure regulator. The low-pressure regulator further reduces the gas pressure to a predetermined level prior to conveying the gas through an outlet to, e.g., an appliance. 
   In many applications, and particularly in the Recreational Vehicle (“RV”) field, at least two gas source containers (a “supply” container and a “reserve” container) are connected to at least two corresponding inlets at the first high-pressure regulator, with each inlet for receiving gas from a different gas source container. During use of the connected appliance, when the supply container becomes depleted of gas, the regulator automatically changes over to the reserve container such that the reserve container becomes the “new supply” container for providing gas to the regulator. After such a changeover, the original supply container can be disconnected from the corresponding inlet of the regulator and be refilled. 
   SUMMARY OF THE PRESENT INVENTION 
   One aspect of the present invention is to provide a pressure regulator comprising a housing having an interior space, at least one input into the interior space and an output out of the interior space. The housing is configured to have a fluid enter into the interior space through the at least one input and exit the interior space through the output. The pressure regulator also includes a closure member for each input. The closure member selectively covers an associated one of the at least one input for preventing fluid flow into the interior space of the housing. The pressure regulator further includes a diaphragm in the housing, with the diaphragm being interconnected to the closure member. The pressure regulator also includes a biasing member for each closure member. The biasing member is configured to selectively bias the closure member away from the associated one of the at least one input to allow fluid flow through the input. The diaphragm is configured to move against the biasing member when pressure in the interior space is above a predetermined amount, whereby the closure member will move in response to movement of the diaphragm to close the at least one input such that fluid is not able to pass into the interior space through the input. The pressure regulator further includes a stabilizing member in the housing. The stabilizing member surrounds the biasing member for maintaining the biasing member in position. 
   Another aspect of the present invention is to provide a pressure regulator comprising a housing, a pair of closure members, a diaphragm, a pair of biasing members and a pair of cups. The housing has an interior space, two inputs into the interior space and an output out of the interior space, with the housing being configured to have a fluid enter into the interior space through at least one of the two inputs and exit the interior space through the output. Each closure member selectively covers an associated one of the two inputs for preventing fluid flow into the interior space of the housing through the associated one of the two inputs. The diaphragm is in the housing and is interconnected to each closure member. Each biasing member is configured to selectively bias one of the closure members away from the associated one of the two inputs to allow fluid flow through the associated one of the two inputs. The diaphragm is configured to move against the biasing members when pressure in the interior space is above a predetermined amount, whereby the closure members will move in response to movement of the diaphragm to close the inputs such that fluid is not able to pass into the interior space through the inputs. Each cup surrounds a bottom of one of the biasing members for maintaining the biasing members in position. 
   Yet another aspect of the present invention is to provide a pressure regulator comprising a housing, a pair of closure members, a diaphragm, a pair of biasing members and a plate. The housing has an interior space, two inputs into the interior space and an output out of the interior space, with the housing being configured to have a fluid enter into the interior space through at least one of the two inputs and exit the interior space through the output. Each closure member selectively covers an associated one of the two inputs for preventing fluid flow into the interior space of the housing through the associated one of the two inputs. The diaphragm is in the housing and is interconnected to each closure member. Each biasing member is configured to selectively bias one of the closure members away from the associated one of the two inputs to allow fluid flow through the associated one of the two inputs. The diaphragm is configured to move against the biasing members when pressure in the interior space is above a predetermined amount, whereby the closure members will move in response to movement of the diaphragm to close the inputs such that fluid is not able to pass into the interior space through the inputs. The plate has a pair of apertures therein, with each aperture surrounding one of the biasing members for maintaining the biasing members in position. 
   In another aspect of the present invention, a pressure regulator is provided. The pressure regulator comprises a housing having an interior space, at least one input into the interior space and an output out of the interior space, with the housing being configured to have a fluid enter into the interior space through the at least one input and exit the interior space through the output. The pressure regulator also includes a closure member for each input, with the closure member selectively covering an associated one of the at least one input for preventing fluid flow into the interior space of the housing. The pressure regulator further includes a diaphragm in the housing, with the diaphragm being interconnected to the closure member. The pressure regulator also includes a biasing member for each closure member, with the biasing member configured to selectively bias the closure member away from the associated one of the at least one input to allow fluid flow through the input. The diaphragm is configured to move against the biasing member when pressure in the interior space is above a predetermined amount, whereby the closure member will move in response to movement of the diaphragm to close the at least one input such that fluid is not able to pass into the interior space through the input. Furthermore, the diaphragm includes a pair of sleeves, with each sleeve having a rolling receiver portion and the diaphragm includes a substantially flat surface portion surrounding the sleeve, whereby the rolling receiver portion can move with movement of the biasing member without substantially moving the substantially flat surface portion. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view showing an exemplary gas regulator embodying the present invention. 
       FIG. 2  is a side view of the gas regulator of the present invention. 
       FIG. 3  is a front view of the gas regulator of the present invention. 
       FIG. 4  is a cross-sectional view of the gas regulator taken along line A-A of  FIG. 3 . 
       FIG. 5  is a perspective view of a lower cup of the present invention. 
       FIG. 6  is a top view of the lower cup of the present invention. 
       FIG. 7  is cross-sectional view of the lower cup taken along line A-A of  FIG. 6 . 
       FIG. 8  is a perspective view of a guide of the present invention. 
       FIG. 9  is a top view of the guide of the present invention. 
       FIG. 10  is a bottom view of the guide of the present invention. 
       FIG. 11  is a cross-sectional view of the guide taken along line A-A of  FIG. 9 . 
       FIG. 12  is a front view of the guide of the present invention. 
       FIG. 13  is a cross-sectional view of the guide taken along line B-B of  FIG. 12 . 
       FIG. 14  is a cross-sectional view of the guide illustrating detail A of  FIG. 13 . 
       FIG. 15  is a side view of the guide of the present invention. 
       FIG. 16  is a perspective view of a diaphragm of the present invention. 
       FIG. 17  is a top view of the diaphragm of the present invention. 
       FIG. 18  is a cross-sectional view of the diaphragm taken along line A-A of  FIG. 17 . 
       FIG. 19  is a bottom view of the diaphragm of the present invention. 
       FIG. 20  is a cross-sectional view of the diaphragm illustrating detail A of  FIG. 18 . 
       FIG. 21  is a cross-sectional view of the diaphragm illustrating detail B of  FIG. 20 . 
       FIG. 22  is a perspective view of a guide of a second embodiment of the present invention. 
       FIG. 23  is a top view of the guide of the second embodiment of the present invention. 
       FIG. 24  is a side view of the guide of the second embodiment of the present invention. 
       FIG. 25  is a side view of the guide of the second embodiment of the present invention illustrating detail A of  FIG. 24 . 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as orientated in  FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting. 
   Referring to the drawings, and in particular to  FIGS. 1-4 , a two-stage LP gas regulator  10  includes a first regulation portion  12  having a high-pressure changeover regulator  13  and a second regulation portion  14  having a low-pressure regulator  15 . The first regulation portion  12  includes a pair of inlets  16 ,  18 , each of which receives gas from a separate gas storage container (not shown). The first portion  12  of the regulator  10  also includes a changeover knob  19  for selecting which of the inlets  16 ,  18  supplies the gas to the high-pressure regulator  13 . In operation, the high-pressure changeover regulator  13  processes gas input from one of the inlets  16 ,  18  by reducing the pressure of the received gas to a predetermined level. The lower-pressure gas is then transmitted to the low-pressure regulator  15  for further reducing the gas pressure to a level that is suitable for use in, e.g., an appliance. As shown in  FIGS. 1-4 , the second regulator  14  includes an outlet  27  for transmitting the gas to the appliance. 
   To begin use, the changeover knob  19  is moved toward whichever inlet  16 ,  18  and container is to be used first, e.g., the “supply” container, thus making the container connected to the other inlet  16 ,  18  the “reserve” container. Thereafter, a main control valve on each of the gas storage containers is opened such that gas is supplied to both inlets  16 ,  18 . Although both inlets  16 ,  18  receive gas from their respective gas storage containers, the changeover knob  19  operates an internal mechanism which selectively couples gas received through only one of the inlets  16 ,  18  to the regulator  10 . After opening the main control valves on the gas storage containers, a full/empty indicator  22  attached to an end  20  of the high-pressure regulator  13  senses the pressure of the gas supplied by the selected storage container and, based on the sensed pressure, indicates the full/empty status of that container. 
   The two-stage LP gas regulator  10  as described herein is identical to a low pressure two-stage LP gas regulator as sold by Marshall Gas Controls, a division of S.H. Leggitt Co. located in San Marcos, Tex., under the part number 254-00, except that the two-stage gas regulator  10  includes a new convoluted diaphragm  100 , a guide  102  and a pair of lower spring cups  104  in the first regulator portion  12 . In the illustrated example, gas is supplied to an interior  50  of the first regulator portion  12  through the inlets  16 ,  18  through a valve seat  52  selectively covered by a lever arm  54  for each inlet  16 ,  18 . In use, the changeover knob  19  is rotated to align a protrusion  55  on the underside of the changeover knob  19  with a spring  56  interconnected with one of the lever arms  54  for a selected inlet  16 ,  18 . The protrusion  55  pushes down on a top piston  58 , which compresses the selected spring  56 . The selected spring  56  therefore pushes a lower cup  106  surrounding a lower end of the spring  56 . The lower cup  106  thereafter presses down on a sleeve  108  of the convoluted diaphragm  100 , which presses down on a diaphragm post  60  that presses down on a first end  61  of the lever arm  54 . When the first end  61  of the lever arm  54  is pressed down, a second end  62  of the lever arm  54  uncovers the valve seat  52  of one of the inlets  16 ,  18  to open a fluid line from one of the inlets  16 ,  18  to the interior  50  of the first regulator portion  12 . If the pressure in the interior  50  of the first regulator portion  12  raises above a predetermined level, the pressure will push the sleeve  108  of the convoluted diaphragm  100  upward, thereby pushing the diaphragm post  60  upward. Therefore, the diaphragm post  60  will pull the first end  61  of the lever arm  54  upward and move the second end  62  of the lever arm  54  into contact with the valve seat  52  to stop fluid from entering the interior  50  of the first regulator portion  12  from the relative inlet  16 ,  18 . 
   In the illustrated example, each lower cup  106  ( FIGS. 5-7 ) includes a circular wall  109 , a disc-shaped lower plate  110  and an inner circular rim  112 . The circular wall  109  surrounds a lower portion of the spring  56  and a terminal lower end of the spring rests on the disc-shaped lower plate  110 . The inner circular rim  112  maintains the terminal lower end of the spring on the disc-shaped lower plate  110 . The diaphragm post  60  is connected to the lower cup  106  through an opening in the disc-shaped lower plate  110 . 
   The illustrated guide  102  ( FIGS. 8-15 ) is located above the lower cups  106  and provides an upper limit for travel of the lower cups  106 . The guide  102  includes a peripheral rim  114  having a cup stopping portion  116  located therein and a base plate  115 . The cup stopping portion  116  includes a pair of circular cup jackets  118  that surround a top portion of the lower cups  106 . The cup jackets  118  are connected to each other, to the peripheral rim  114  and to the base plate  115 . A double wish-bone shaped stop  120  is connected to a top of the cup jackets  118 . If the lower cups  106  move too far upward, the lower cups  106  will abut a bottom of the stop  120 , thereby preventing upward movement of the lower cups  106 . The guide  102  is preferably die cast metal. 
   In the illustrated example, the convoluted diaphragm  100  ( FIGS. 16-21 ) includes a planar sheet  122  having two sleeves  108  therein. Each sleeve  108  receives one of the lower cups  106 . The sleeves  108  are circular and include an upward portion  124  connected to the planar sheet  122 , a rolling receiver  126  connected to the upward portion  124  and a bottom plate  128  connected to a bottom portion of the rolling receiver  126 . The rolling receiver  126  surrounds the lower cup  106  and the lower cup  106  rests on the bottom plate  128 . In use, pressure in the interior  50  of the first regulator portion  12  will press up against the bottom plate  128  of the sleeve  108  when the pressure rises above the predetermined level. As the bottom plate  128  of the sleeve  108  is pushed upward, the rolling receiver  126  will move upward, thereby rolling onto the upward portion  124  to enlarge the upward portion  124 . 
   In a second embodiment of the two-stage LP gas regulator, the gas regulator is identical to the low pressure two-stage LP gas regulator as sold by Marshall Gas Controls, a division of S.H. Leggitt Co. located in San Marcos, Tex., under the part number 254-00, and further includes a spring guide  200  ( FIGS. 22-25 ). The spring guide  200  surrounds the springs  56  and maintains the springs  56  over the respective portion of a flat diaphragm (or a pair of flat diaphragms) and the respective post. The spring guide  200  includes a flat plate  202  with a pair of circular apertures  204 . Each of the springs  56  is positioned into one of the apertures  204 . The spring guide  200  also preferably includes a stiffening rib  206 . 
   The foregoing detailed description is considered that of a preferred embodiment only, and the particular shape and nature of at least some of the components in this embodiment are at least partially based on manufacturing advantages and considerations as well as on those pertaining to assembly and operation. Modifications of this embodiment may well occur to those skilled in the art and to those who make or use the invention after learning the nature of this preferred embodiment, and the invention lends itself advantageously to such modification and alternative embodiments. Therefore, it is to be understood that the embodiment shown in the drawings and described above is provided principally for illustrative purposes. 
   It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.