Abstract:
A mechanical valve assembly for the control of a gas flow to a gas appliance, the mechanical valve assembly comprising: a housing; a gas inlet port associated with the housing; a gas outlet port associated with the housing; a timer-controlled valve operable to open and close a gas flow between the inlet port and outlet port; and a manually-operated emergency shut-off valve positioned between the inlet port and the outlet port, ahead of the timer-controlled valve relative to a direction of the gas flow through the mechanical valve assembly.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to mechanical devices for the control of a gas flow, and, more particularly, to a mechanical valve assembly utilized therein. 
         [0003]    2. Description of the Related Art 
         [0004]    In many applications, a flow of gas is required to operate various appliances. Some appliances, for example, include fireplaces, stoves, ovens, furnaces, heaters, etc. Because of inherent sudden and/or unforeseen circumstances surrounding the use of such apparatuses, it is desired to be provided with a way of controlling the gas flow in general, and shutting off the gas flow in particular. 
         [0005]    It is known in the art to have separate valves for controlling gas flow: a primary valve that is used to turn on and off the gas flow in normal operations, and a separate electrically-operated valve to shut off the gas flow. The latter valve is sometimes referred to as an “emergency shut-off” valve. The function of the emergency shut-off valve is to completely stop the flow of gas to the appliance until various courses of action are taken. 
         [0006]    Depending upon the types of valves and the applications in which they are used, various problems can be encountered. One problem is the reliance of the emergency shut-off valve upon electricity. In an urgent situation where the power source may be unreliable or completely absent, the emergency valve would fail to operate and thereby allow the gas flow to continue unabated. Further, an electrical connection may not be reliable and prone to disruption. 
         [0007]    Another problem that can be encountered is the distance between the two valves. If the emergency shut-off valve is at a distance from the primary valve, there may be a lag in the time an urgent situation is noted and the emergency shut-off valve is actuated. Furthermore, the distance can create more opportunities for failure as a result of additional conduits, wiring, etc. between the two valves. 
         [0008]    What is needed in the art is an apparatus to reliably shut off a timed flow of gas in an urgent situation. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention is directed to an improved mechanical valve assembly incorporating features that enable it to allow a timed gas flow as well as interrupt the gas flow, whether or not the timed gas flow is in operation. 
         [0010]    The present invention provides a mechanical valve assembly with a time-controlled valve to allow a gas flow through the mechanical valve assembly for a predetermined time. A mechanical valve assembly with an emergency shut-off valve is positioned ahead of the timer-controlled valve relative to a direction of the gas flow through the mechanical valve assembly to interrupt a gas flow through the mechanical valve assembly. 
         [0011]    The present invention further provides a mechanical valve assembly with a shaft assembly operable by both the time-controlled valve as well as the emergency shut-off valve. 
         [0012]    An advantage of the present invention is that the operation of the timer-controlled valve, emergency shut-off valve, and shaft assembly is purely of a mechanical nature and does not require electronics to function. 
         [0013]    Another advantage of the present invention is the emergency shut-off valve is capable of interrupting a gas flow whether or not the timer-controlled valve is in operation. 
         [0014]    Yet another advantage of the present invention is the emergency shut-off valve must be depressed and simultaneously rotated to allow gas flow, thereby serving as a safety device. 
         [0015]    Still another advantage of the present invention is that the timer-controlled valve and the emergency shut-off valve are located proximate to each other in the housing and operate the same valve, thereby eliminating components and making access and operation easier. 
         [0016]    Yet another advantage is as a result of the timer-controlled valve and the emergency shut-off valve having separate locations in the same mechanical valve assembly, the gas flow can be shut off by either valve; that is, there is less risk than would be encountered if the two valves were located on the same working shaft, for example. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0018]      FIG. 1  is a perspective view of an embodiment of a mechanical valve assembly of the present invention; 
           [0019]      FIG. 2  is a top view of the mechanical valve assembly of  FIG. 1  in two parts; 
           [0020]      FIG. 3  is a top sectioned view of the mechanical valve assembly of  FIG. 1  with selected components, showing gas flowing in an ON condition; 
           [0021]      FIG. 4  is a top sectioned view of the mechanical valve assembly of  FIG. 1  with selected components, showing an OFF condition with no gas flowing; 
           [0022]      FIG. 5A  is a sectioned side view of a portion of an emergency shut-off valve of the mechanical valve assembly of  FIG. 1  in an ON position to allow gas flow; 
           [0023]      FIG. 5B  is a sectioned side view of a portion of an emergency shut-off valve of the mechanical valve assembly of  FIG. 1  in an OFF position to allow gas flow; and 
           [0024]      FIG. 6  is a top sectioned view of the mechanical valve assembly of  FIG. 1  with selected components, showing an OFF condition with no gas flowing. 
       
    
    
       [0025]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates an embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    Referring now to  FIGS. 1-2 , there is shown an embodiment of a mechanical valve assembly  10  according to the present invention. Mechanical valve assembly  10  includes housing  12 , emergency shut-off valve  14 , timer-controlled valve  16 , and shaft assembly  26 . It is to be understood that the spatial relationship between emergency shut-off valve  14  and timer-controlled valve  16 , as well as their respective locations on mechanical valve assembly  10 , may vary from the embodiment shown in  FIG. 1  without changing the scope of the invention. 
         [0027]      FIG. 2  shows the housing  12  of mechanical valve assembly  10  disassembled into two sections: cover plate  18 , and base  20 . Screws or other fasteners used to removably join cover plate  18  to base  20  are not shown. 
         [0028]    Now referring to  FIG. 3 , base  20  of mechanical valve assembly  10  is shown with selected components, showing gas flowing in an ON condition. Base  20  includes gas inlet port  22 , gas outlet port  24 , and seat  28 . As shown, it is to be understood that the ON position signifies gas  48  is able to flow unobstructed from gas inlet port  22  to gas outlet port  24  (from A to B). Shaft assembly  26  includes spring  34 , seal  44  and shaft  46 . Gas  48  is able to flow unobstructed from gas inlet port  22  to gas outlet port  24  because while in the ON position, seal  44  of shaft assembly  26  is not resting on seat  28  of base  20 . Seal  44  of shaft assembly  26  is not resting on seat  28  of base  20  because timer-controlled valve  16 , which includes timer mechanism  32  and activation bar  30 , is in an ON position and has been set to a predetermined time for gas to flow through mechanical valve assembly  10 . Until the predetermined time has expired, activation bar  30  displaces slidably attached seal  44  on shaft  46  of shaft assembly  26  from seat  28  of base  20  while simultaneously compressing spring  34 . 
         [0029]    In the ON condition shown in  FIG. 3 , emergency shut-off valve  14  is also in an ON position (see  FIG. 5A ), the details of which are described in detail later in this specification. Spring plate  36 , pivotally mounted in base  20 , is undisplaced. 
         [0030]    Now referring to  FIG. 4  with continued reference to  FIG. 3 , base  20  of mechanical valve assembly  10  is shown with selected components, showing gas flowing in an OFF condition. As shown, it is to be understood that the OFF position signifies gas  50  is not able to flow unobstructed from gas inlet port  22  to gas outlet port  24  (from A, stopping at C). Gas is not able to flow unobstructed from gas inlet port  22  to gas outlet port  24  because while in the OFF position, seal  44  of shaft assembly  26  is resting on seat  28  of base  20 . Seal  44  of shaft assembly  26  is resting on seat  28  of base  20  because timer-controlled valve  16  is in an OFF position either because it was manually put into that position, or because a predetermined time for gas to flow through mechanical valve assembly  10  has expired. When timer-controlled valve  16  is in the OFF position, activation bar  30  does not displace shaft  46  of shaft assembly  26 , thereby allowing spring  34  to decompress and urge seal  44  on shaft  46  of shaft assembly  26  to contact seat  28  of base  20 . 
         [0031]    In the OFF condition shown in  FIG. 4 , emergency shut-off valve  14  is in an ON position (see  FIG. 5A ), the details of which are described in detail later in this specification. As is the case when timer-controlled valve  16  is in the ON position, spring plate  36  is undisplaced. 
         [0032]    Now referring to  FIGS. 5A-B  with continued reference to  FIGS. 3 and 4 , emergency shut-off valve  14  is detailed. Emergency shut-off valve  14 , located ahead of and similar to timer-controlled valve  16 , is capable of operating in two modes: ON and OFF. As detailed above and seen in  FIGS. 3, 4, and 5A , emergency shut-off valve  14  is in an ON position during normal operation; that is, emergency shut-off valve  14  in an ON position does not affect the operation of timer-controlled valve  16  to act as a primary valve in allowing gas to flow or stopping gas from flowing through mechanical valve assembly  10 . 
         [0033]    Emergency shut-off valve  14  includes shaft  38 , spring  40 , and knob  42 .  FIG. 5A  shows a cross-section of emergency shut-off valve  14  in an ON position. In this position, spring plate  36  (also seen in  FIGS. 3 and 4 ) is in a resting position with respect to shaft  38  of emergency shut-off valve  14  and seal  44  of shaft assembly  26 ; that is, it is proximate to but does not displace seal  44 , thereby allowing timer-controlled valve  16  to determine whether or not gas is able to flow. 
         [0034]    In contrast to the ON position of emergency shut-off valve  14  shown in  FIG. 5A , emergency shut-off valve  14  is also capable of operating in an OFF mode as shown in  FIG. 5B  and now also referring to  FIG. 6 . As can be seen particularly in  FIG. 5B , timer-controlled valve  16  is in an ON position. As emergency shut-off valve  14  is activated by pushing knob  42 , spring  40  is compressed and shaft  38  displaces spring plate  36  in a pivotal manner. The displacement of spring plate  36 , which had previously been proximate to but not displacing seal  44  of shaft assembly  26 , now displaces seal  44  and seats it against seat  28  of base  20 , thereby preventing gas flow from gas inlet port  22  to gas outlet port  24 . 
         [0035]    In addition to the above consequences of pushing knob  42  of emergency shut-off valve  14 , it can also be seen in  FIG. 5B  that knob  42  is then captured by cover plate  18 . In order to re-set emergency shut-off valve  14  (bring it back into an ON position) while timer-controlled valve  16  is in an ON position, knob  42  must be rotated. This rotation of knob  42  allows spring  40  to decompress, thereby urging shaft  38  upwards and consequently returning spring plate  36  to its neutral position, thereby allowing seal  44  to be unseated. 
         [0036]    As previously disclosed, emergency shut-off valve  14  can also be used when timer-controlled valve  16  is in an OFF position. This prevents the operation of timer-controlled valve  16  until knob  42  is rotated as described above. Thus, emergency shut-off valve  14  can also function as a safety device. 
         [0037]    While mechanical valve assemblies have been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.