Abstract:
An earthquake actuated device includes a flapper-valve adapted to block a gas flow and a micro switch for closing or opening a circuit. A seismic sensor responds to accelerations characteristic of an earthquake. The sensor cooperates with a magnet in a flapper arm to hold the flapper-valve open. When the sensor experiences sufficient motion, the flapper arm is released and the flapper-valve falls onto a seat, thereby closing and blocking the gas flow. The closing of the flapper-valve is further coupled into an actuation of the micro switch, thereby opening or closing the circuit.

Description:
BACKGROUND OF THE INVENTION 
   The present application is a Continuation In Part of U.S. application Ser. No. 10/844,884 filed May 14, 2004. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to earthquake safety devices, and more particularly to devices which close a valve and actuate a micro switch as a result of an earthquake. 
   There is world wide concern regarding the effects of earthquakes. In recent years, earthquakes occurring around the world resulted in tens of thousands of deaths. Although modern building codes drastically reduce the human harm resulting from earthquakes, there is still a significant likelihood that deaths will occur even in modern countries. Although building codes have been successful in reducing the catastrophic collapse of structures, there is often substantial secondary damage resulting from gas fires, broken electrical wiring, and the like. Various devices have been developed to turn off gas lines and the like, either directly through a mechanical action, or indirectly through actuation of an electrical switch. 
   One such device is described in U.S. Pat. No. 4,185,507 for “Acceleration Responsive Tripping Mechanism,” which describes a ball sitting on a pedestal. When motion occurs, the ball falls off the pedestal into a surrounding chamber (or dish), causing the chamber to lower against a spring, and to trip a micro switch. Disadvantageously, the device of the &#39;507 patent includes a number of moving parts including a spring, vertically moving piston, and levers. Devices such as this are generally mounted, and forgotten. There is typically little to no inspection or maintenance, and as a result, such complexity is an invitation to failure. 
   U.S. Pat. No. 4,261,379 for “Vibration/Temperature Sensitive Valve Operating Apparatus,” describes a ball siting in a cup. Motion causes the ball to fall out of the cup, and the cup raises slightly, this motion releases a trigger which results in the desired actuation. Unfortunately the &#39;379 patent also includes substantial mechanical complexity, including several arms, springs, and pins. Such mechanical complexity is undesirable for the reasons cited above. 
   A simple device for directly turning off a gas flow is described by U.S. Pat. No. 5,209,454 for “Automatic Safety Shutoff Valve,” which is assigned the inventor of the present invention. The &#39;454 patent describes several embodiments of a flapper-type gas valve which closes when experiencing the accelerations characteristic of an earthquake. While the valve of the &#39;454 patent provides the desired gas shut-off functionality, in some applications there is an additional need for a valve which both shuts off a gas flow, and provides an electrical signal for an alarm or monitor. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention addresses the above and other needs by providing an earthquake actuated device includes a flapper-valve adapted to block a gas flow and a micro switch for closing or opening a circuit. A seismic sensor responds to accelerations characteristic of an earthquake. The sensor cooperates with a magnet in a flapper arm to hold the flapper-valve open. When the sensor experiences sufficient motion, the flapper arm is released and the flapper-valve falls onto a seat, thereby closing and blocking the gas flow. The closing of the flapper-valve is further coupled into an actuation of the micro switch, thereby opening or closing the circuit. 
   In accordance with one aspect of the invention, there is provided an earthquake actuated valve and switch. The valve and switch include a valve housing having a gas inlet and a gas outlet, a seismic sensor having a rest position and a disturbed position, a flapper-valve having an open position and a closed position, and an electrical switch mechanically actuated by the flapper-valve. The flapper-valve is adapted to be held in the open position when the seismic sensor is in the rest position, and the flapper-valve is adapted to fall into the closed position when the seismic sensor moves from the rest position to the disturbed position. The electrical switch is actuated when the flapper-valve moves between the open position and the closed position. 
   In accordance with another aspect of the present invention a method is provided for closing a gas valve and actuating a switch in the event of an earthquake. The method comprises steps of aligning a seismic sensor to hold a flapper-valve in an open position, coupling a valve housing containing the seismic sensor to a structure that experiences accelerations during an earthquake, disturbing the seismic sensor when an earthquake occurs, allowing the flapper-valve to fall against a seat to block a flow of gas when the seismic switch is disturbed, coupling the fall of the flapper-valve to a switch actuator of an electrical switch, and actuating the switch. The method may further include turning a set lever to close the flapper-valve and actuate the switch, and turning a reset mechanism to open the flapper-valve and de-actuate the switch. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: 
       FIG. 1A  is a side view of a valve and switch according to the present invention. 
       FIG. 1B  is a top view of the valve and switch. 
       FIG. 1C  is an end view of the valve and switch. 
       FIG. 2A  is a cross-section view of the interior of the valve and switch taken along line  2 — 2  of  FIG. 1A  with a flapper-valve open. 
       FIG. 2B  is a second cross-section view of the interior of the valve and switch taken along line  2 — 2  of  FIG. 1A , with the flapper-valve closed due to seismic accelerations. 
       FIG. 2C  is a third cross-section view of the interior of the valve and switch taken along line  2 — 2  of  FIG. 1A , with the flapper-valve closed due to use of a set lever. 
       FIG. 2D  is a fourth cross-section view of the interior of the valve and switch taken along line  2 — 2  of  FIG. 1A , showing a switch arm mechanically cooperating with the flapper-valve. 
       FIG. 3A  is a side view of a second valve housing and an externally mounted electrical switch. 
       FIG. 3B  is a cross-sectional top view taken along line  3 B— 3 B of  FIG. 3A  of a portion of the second valve housing and the externally mounted electrical switch. 
       FIG. 3C  is a cross-sectional end view taken along line  3 C— 3 C of  FIG. 3A  of a portion of the second valve housing and the externally mounted electrical switch. 
       FIG. 3D  is a cross-sectional end view taken along line  3 C— 3 C of  FIG. 3A  of a portion of the second valve housing and the externally mounted electrical switch with the switch actuated. 
       FIG. 4A  is a side view of a third valve housing and a second externally mounted electrical switch. 
       FIG. 4B  is a side view showing elements for actuating the second externally mounted electrical switch. 
       FIG. 4C  is top view of a portion of the third valve housing and the second externally mounted electrical switch and actuating elements. 
       FIG. 5  shows a switch cable held to the valve housing using an o-ring and o-ring retainer. 
       FIG. 6  is a method for blocking a flow of gas and actuating a switch. 
   

   Corresponding reference characters indicate corresponding components throughout the several views of the drawings. 
   DETAILED DESCRIPTION OF THE INVENTION 
   The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims. 
   An earthquake actuated valve and switch  10  according to the present invention is shown in side view in  FIG. 1A , in top view in  FIG. 1B , and in end view in  FIG. 1C . The valve and switch  10  includes both a gas flow control and electrical switching. The gas flow control structure is similar to the structure described in U.S. Pat. No. 6,112,764 for Automatic Safety Shutoff Valve,” issued to the inventor of the present invention, and in particular as described in  FIG. 1  as modified by  FIG. 5  of the &#39;764 patent. In the event of an earthquake, a seismic sensor (see  FIG. 2A ) triggers closing the flapper-valve. Such a seismic sensor is described in U.S. Pat. No. 5,307,699 for “Seismic Initiator for Earthquake Shutoff Valves and the Like,” also issued to the inventor of the present invention. The &#39;764 and &#39;699 patents are hereby incorporated by reference. 
   The valve and switch  10  includes a control portion  17  including a set mechanism housing  12 , a set lever  14  turnable about arc A 1 , a sensor housing cap  36 , a window  28 , and a sensor housing  16 . First o-ring  37   a  forms a seal between the sensor housing cap  36  and the sensor housing  16 . A valve housing  18  resides below the control portion  17  and includes a reset control  20  turnable about arc A 2 , a switch access  22  for providing access to an internal electrical switch, and a cable  24  carrying conductors  26 . A gasket  34  (or alternatively, a sealer) resides between the sensor housing  16  and the valve housing  18 . The window  28  allows viewing into the valve housing  18  to ascertain the state (i.e., open or closed) of the valve and switch  10 . The various parts of the valve and switch  10  are attached by screws  30  of various sizes. The screws  30  may be slot screws, phillips screws, allen head screws, torx® screws, anti-tamper screws, or any screw type suitable to attaching the various parts. The screws  30  are preferably machine screws. 
   A cross-sectional view of the valve and switch  10  taken along line  2 — 2  of  FIG. 1B  is shown in  FIG. 2A . The set lever  14  connects to a magnet carrier  44  residing inside the set mechanism housing  12 . A first magnet  46   a  resides in the magnet carrier  44 . A seismic sensor comprises a shaft  40  loosely carrying a mass  38 , and a conical base  42  resides inside the sensor housing  16 . An upper end of the shaft  40  resides in a shaft cavity  53 , wherein the shaft  40  may lean but still be constrained to a maximum lean. The function and structure of the seismic sensor is described in U.S. Pat. No. 5,307,699 for “Seismic Initiator for Earthquake Shutoff Valves and the Like.” The seismic sensor normally rests squarely in a base cavity  43  (i.e., a flat lower surface of the conical base  42  rests parallel and on the floor of the base cavity  43 ). The structure and function of the set lever  14 , magnet carrier  44 , and magnet  46   a  are described in U.S. Pat. No. 6,112,764 for Automatic Safety Shutoff Valve,” in FIGS. 5, 6, and 7. The &#39;699 and 764 patents are incorporated by reference above. 
   A flapper arm  48 , and a flapper-valve  50  attached to the flapper arm  48 , pivot about a valve pivot  21 . The flapper arm  48  and flapper-valve  50  are depicted in an open position in  FIG. 2A  wherein the flapper arm  48  and flapper-valve  50  are approximately horizontal. A second magnet  46   b  resides in the flapper arm  48  adjacent to the seismic sensor shaft  40 , wherein magnetic attraction between the magnet  46   b  and the shaft  40  hold the flapper arm  48  and flapper-valve  50  in the open position allowing an inlet flow  56  to enter the inlet  54 , pass though the valve housing  18 , and exit as an outlet flow  60  through the outlet  58 . The inlet  54  and the outlet  58  are approximately horizontal and are aligned to receive substantially horizontally running lines or pipes. The inlet  54  is preferably horizontally displaced from the outlet  58  thereby allowing easy connection into a horizontally running line. 
   A switch  62  resides in the valve housing  18  and includes a switch actuator  64  for actuating the switch  62 . The switch  62  is held in place by fasteners  66  which preferably comprise screws, and more preferably comprise #2 screws and lock washers. Three of the conductors  26  connect to a normally open post, a normally closed post, and a neutral post on the switch  62 . A fourth conductor  26  is grounded to the valve housing  18 , preferably by a #2 screw and lock washer. The switch  62  is preferably a micro switch, more preferably a Single-Pole Double-Throw (SPDT) micro switch, and most preferably a type 15X, style 4, 311 5X 3-T micro switch manufactured by Honeywell in Morristown, N.J. The cable  24  is held in place in the valve housing  18  by a set screw  70  which is preferably a ¼ inch-20 by ¼ inch hex socket set screw having a cup point. The cable  24  and set screw are sealed to prevent gas leaks, preferably using DOW CORNING RTV 734 adhesive sealant. 
   A second cross-sectional view of the valve and switch  10  taken along line  2 — 2  of  FIG. 1B  is shown in  FIG. 2B . The seismic sensor is shown in a disturbed position and no longer resides squarely in the rest position in the base cavity  43  (see  FIG. 2A ). The magnet  46   b  is somewhat separated from the shaft  40 , thus reducing the magnetic attraction between the seismic sensor and the magnet  46   b  and thereby releasing the flapper arm  48  and attached flapper-valve  50 . The flapper arm  48  and flapper-valve  50  are shown having pivoted along arc A 3  around the valve pivot  21  into a closed (or fallen) position against the seat  51  (see  FIG. 2A ). The pin  52  (see  FIG. 2A ) is pressed against the switch actuator  64  thereby actuating the switch  62 . 
   A third cross-sectional view of the valve and switch  10  taken along line  2 — 2  of  FIG. 1B  is shown in  FIG. 2C . The set lever  14 , magnet carrier  44 , and magnet  46   a  have been turned along arc A 1  (see  FIG. 1 ) to a position where the magnet  46   a  is aligned with the shaft  40 , thereby raising the seismic sensor. As a result the magnet  46   b  is somewhat separated from the shaft  40 , thus releasing the flapper arm  48  and attached flapper-valve  50 , thus closing the valve and switch  10  and actuating the switch  62 . The structure and use of the set lever  14  is described in FIG. 5 U.S. Pat. No. 6,112,764 for Automatic Safety Shutoff Valve,” incorporated by reference above. 
   In some uses, it is desirable that the micro switch  62  does not reside inside the valve housing. A fourth cross-sectional view of the valve and switch  10  taken along line  2 — 2  of  FIG. 1B  is shown in  FIG. 2D . A second valve housing  18   a  with a first switch arm  72  is shown in mechanical cooperation with the pin  52  (see  FIG. 2A ) whereby closing the flapper-valve is coupled into a motion of the switch arm  72 . 
   A side view of the valve housing  18   a  is shown in  FIG. 3A . The switch  62  is attached to the outside of the housing  18   a , which switch  62  is inverted and at approximately a 45 degree angle, thereby aligning the switch actuator  64  approximately perpendicular to the motion imparted from the seal  50  to the switch arm  72   a . The switch arm  72   a  extends though a diaphragm  74  in the side of the housing  18   a , which diaphragm  74  flexibly supports the switch arm  72   a . The diaphragm is preferably a flexible metal diaphragm or an elastomer diaphragm. The externally mounted switch is preferably a micro switch, and more preferably a 311 SM702-T switch manufactured by Honeywell in Morristown, N.J. 
   A cross-sectional top view of a portion of the valve housing  18   a  taken along line  3 B— 3 B of  FIG. 3A  is shown in  FIG. 3B , and a cross-sectional end view taken along line  3 C— 3 C of  FIG. 3A  in  FIG. 3C . The switch arm  72   a  is shown extending through the diaphragm  74  to cooperate with the switch actuator  64 . A second cross-sectional end view taken along line  3 C— 3 C is shown in  FIG. 3D  wherein an interior end of the switch arm  72   a  has been depressed by the pin  52  as depicted in  FIG. 2D . The switch arm  72   a  pivots about an axis approximately in the plane of the diaphragm  74  and an exterior end of the switch arm  72   a  pushes the switch actuator  64  upward to activate the switch  62 . 
   A side view of a third valve housing  18   b  is shown in  FIG. 4A . A second switch arm  72   b  is attached to a switch shaft  80  extending though a side of the valve housing  18   b . The switch  62  is mounted on the side of the valve housing  18   b . The switch arm  72   b  rotates along arc A 4  when the flapper-valve  50  is closed, and thereby pushes the switch actuator  64  up, and activates the switch  62 . A view of the elements providing actuation of the switch  62  are shown in  FIG. 4B . The when the seal  50  closes along arc A 3 , the pin  52  pushed against a third switch arm  72   c . The arm  72   c  pivots about the shaft  80  as indicated by arc A 5 . The shaft  80  couples the rotation to the arm  72   b , causing the arm  72   b  to pivot along arc A 4 , thereby lifting the switch actuator  64  and actuating the switch  62 . A top view of a portion of the valve housing  18   b  and the switch actuating elements are shown in  FIG. 4C . Second o-ring  37   b  forms a seal between the valve housing  18   b  and the shaft  80 . 
   A second method of sealing and/or securing the cable  24  to the valve housing  18  is shown in  FIG. 5 . A third o-ring  37   c  forms a seal between the cable  24  and the valve housing  18 , which o-ring  37   c  is retained by an o-ring retainer  78 . 
   A method for closing a gas valve and actuating a switch in the event of an earthquake is described in  FIG. 6 . The method includes aligning a seismic sensor to hold a flapper-valve in an open position at step  100  and coupling a housing containing the seismic sensor to a structure that experiences accelerations during an earthquake at step  102 . An earthquake occurrence disturbs the seismic sensor at step  104 , allowing the flapper-valve to fall against a seat to block a flow of gas at step  106 , The fall of the flapper-valve is coupled to a switch actuator of an electrical switch at step  108 , actuating the switch at step  110 . The method may further include turning a set lever to close the flapper-valve and actuate the switch, and/or turning a reset mechanism to open the flapper-valve and de-actuate the switch. 
   While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.