Patent Publication Number: US-6338624-B1

Title: Automatic putting-out apparatus

Description:
FIELD OF THE INVENTION 
     The present invention relates to an automatic putting-out apparatus and particularly to an automatic putting-out apparatus which can be used to control room heating by automatically interrupting combustion when the room temperature reaches a predetermined temperature. 
     BACKGROUND OF THE INVENTION 
     A variety of fire putting-out means have been developed so far in the field of room heating, which can put off heating apparatuses when the room temperature reaches a certain level. 
     As an example, a Japanese patent publication 41/12269 discloses a heating controller wherein the flow of fuel through a main combustion device is controlled by operating a control valve in a bleed line to adjust the pressure depending on the room temperature. This system, however, is not suited for practical use because it includes so many different components like pressure controllers, several valves, lever devices with temperature-responding members and supporting means to maintain the lever devices at neutral position that responding speed is not only slow but also its construction is very complicated and costly. 
     As another typical type widely used in many countries, there are fire extinguishers based on bimetals in which a power switch is operated based on a bimetal plate to actuate a motor to shift operating load through rotary movement of an eccentric cam to thereby interrupt ignition. This kind of system is also associated with drawbacks in that an electric circuit comprising an connector to operate a motor by bending bimetal through heating based on the difference in thermal expansion of metals is needed and further both a device for interrupting combustion and a mechanism for initiating combustion are required, resulting in complex operation and high manufacturing cost. 
     SUMMARY OF THE INVENTION 
     Under the circumstances stated above, the present inventors made an intensive effort to develop an automatic putting-out apparatus which is simple in construction and easy in operation to be adapted for practical embodiment and which can contribute to improvement in human health by controlling the levels of harmful gases like carbon monoxide and carbon dioxide in the air in a room where the heater is installed as well as the room temperature within acceptable levels. As the result, an automatic putting-out apparatus which can fulfill the sought desire in spite of a simple structure has been devised. 
     The present invention takes the advantage of a property of a shape-memory alloy which restores its original shape at the critical temperature intrinsic of the material of the alloy regardless of its ability to deform freely below that temperature to actuate the switching means of the putting-out apparatus in response to a certain elevated temperature. The approximate relation of the accumulation of harmful indoor gases with the room temperature is also used. Thus, the object of the present invention is to provide an automatic putting-out apparatus which is reliable to operate for prevention of overheating or fire and for preserving human health and is simple to construct by using a shape-memory alloy, is manufactured at a low cost mainly because of elimination of electric power and motor and can be operated irrespective of electric power failure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     An automatic putting-out apparatus according to the first embodiment of the present invention is represented in FIGS. 1 to  5   b,  of which: 
     FIG. 1 shows the present invention in installed state, 
     FIG. 2 shows the perspective view of the present invention, 
     FIG. 3 shows an exploded perspective view of a major part of the invention, 
     FIGS. 4 a  and  4   b  show the operative states of the present invention and 
     FIGS. 5 a  and  5   b  show the operative states of the lever in the present invention. 
     An automatic putting-out apparatus according to the second embodiment of the present invention is represented in FIGS. 6 to  10   b,  of which: 
     FIG. 6 shows the present invention in installed state, 
     FIG. 7 shows the perspective view of the present invention, 
     FIG. 8 shows an exploded perspective view of a major part of the invention, 
     FIGS. 9 a  and  9   b  show the operative states of the present invention and 
     FIGS. 10 a  and  10   b  show the operative states of the lever in the present invention. 
    
    
     DETAILED DRAWINGS OF THE INVENTION 
     The invention will be described in detail below by referring to the accompanying drawings. 
     First, an automatic putting-out apparatus according to the first embodiment of the present invention is described with reference to FIGS. 1 to  5   b.:    
     The rotary shaft  1  is securely provided with a grip  1   a,  which can be turned clockwise to raise a wick or wicks in a wick case  2 , wherein the rotary shaft  1  is prevented from reverse rotation due to a ratchet  4  with a lever  6 , as seen best in FIG. 5 a.    
     A shutting-off knob  7  and a safety weight  8  are arranged on a frame  5 , beside the lever  6 . The lever  6  is provided with a switching bar  6   b  at a position on its leading end part, which bar serves to prevent reverse rotation of the ratchet  4  when it is engaged with the ratchet  4  under the elastic force of a leaf spring  6   a.  The lever  6  is mounted on a lever shaft  6   c  pivotally in a frame  5 , which lever shaft is provided with a torsion bar  6   d.  The lever shaft  6   c  spans the opposite walls of the frame  5 . 
     The lever  6  is disposed pivotally and elastically through a torsion spring  6   d  arranged around the lever shaft  6   c,  as also seen clearly in FIG. 5 a  or  b.  When the lever  6  is raised on the left side of the drawings, the blocking bar  6   b  which was locked on the ratchet  4  is lowered to leave the ratchet  4 , freeing it. Then, the rotation shaft  1  which has been rotated clockwise is now turned anticlockwise due to the torque of a torsion spring  3  mounted on the shaft  1  to return to the original state, whereby the wick  2  is lowered to extinguish the combustion. 
     The switching knob  7  which can be used to interrupt the combustion as required is provided elastically on the front side of the frame  5 . When the knob  7  is pressed down, the lever  6  is raised to free the ratchet  4  through the switching bar  6   b  to thereby perform putting-out, as described above. 
     A safety weight  8  which is a safety measure intended to prevent a fire for a possible case of the heating apparatus being tilted or moved is arranged on the top of the frame  5  so that this weight may be tilted in any direction and extends down through the lever  6  at a position on the outer side of the lever shaft  6   c.  Thus, any considerable inclination of the safety weight  8  with the inclination of the heating apparatus would actuate the lever  6  to ascend so that automatic putting-out may be conducted as described above. 
     A bracket  10  is bent to form spring connections  11  and  12  on its top corner and is also bent to form a securing piece  13  on the other top corner of the bracket, which securing piece is secured to the frame  5  by means of a screw S 1 . The bracket is also formed at a central position with a hole  14  to receive a shaft pin P 1 , as seen in FIGS. 2 and 3. 
     A blocking plate  20  is formed on the top and middle parts on its one side with spring connections  22  and  23 , is formed on the bottom on its other side with an actuating piece  21  to be in contact with the bottom surface of the lever  6  and is further formed at a central position with a hole  24  for receiving a shaft pin P 1 . Therefore, the blocking plate  20  can be mounted to the bracket  10  pivotally by means of the shaft pin P 1 , wherein the blocking plate  20  may be limited in its pivotal motion by the projection  15  formed on the bracket  10  in assembled state. The spring connection  23  of the blocking plate  20  comes in contact with the projection  15  also in the assembled state. 
     The coil spring  30  both ends of which are respectively connected to the spring connection  11  of the bracket  10  and the spring connection  22  of the blocking plate  20  is made of such a shape-memory alloy as would undergo change in its shape at a room temperature between 20° C. and 32° C. which temperature corresponds to the levels of CO concentration of 0.01% and CO 2  concentration of about 1% based on the case of ordinary room heating, so that putting-out takes place well ahead of dangerous level for such harmful gases. Detailed operation in this connection will be given later. 
     As a shape-memory alloy suited for the coil spring  30 , various alloys including Ti—Ni alloy and aluminum alloys may be mentioned. Preferably the intrinsic critical temperature may be set at an environmental temperature between 20° C. and 32° C., and particularly between 23° C. and 28° C., as suggested above. 
     Still referring to FIGS. 2 and 3, a bias spring  40  is connected, with its both ends, to the bracket  10  at the spring connection  12  and to the blocking plate  20  at the spring connection  23 . The bias spring  40 , which may be formed of a torsion spring or leaf spring, acts as a mere bias spring while helping maintenance of the hysteretic behavior for the coil spring  30  below the specific temperature below which the coil spring  30  does not operate automatically for fire putting-out but boosts the working force of the coil spring  30  by deforming in such a way as to exert force in the same direction as the force of the coil spring  30  above the above-mentioned temperature. 
     That is, in the case the torque (M×L 1 ) by the coil spring  30  is smaller than that (K×L) by the bias spring  40 , or M×L 1 &lt;K×L, the blocking plate  20  makes no movement, while, if the coil spring  30  has a larger force as the temperature rises due to its shape restoring habit, or K×L&lt;M×L 1 , the blocking plate  20  goes into action, as shown in FIG. 4 b.  At that time, when the position of the bias spring  40  or the connecting point  23  of the spring  40  with the blocking plate  20  crosses the center line ( 01 - 02 ) connecting the hinge point  12  on the bracket  10  and the hinge point  24  on the blocking plate  20 , the direction of force for the bias spring  40  is reversed to be anticlockwise so that the large combined torque of M×L 1  for the coil spring  30  and K×L for the bias spring  40  may act on the lever  6  for automatic hasty putting-out. Moreover, more accurate hysteresis and constant physical property for the coil spring  30  can be maintained before its temperature-dependant actuation, as the bias spring  40  can be kept within a minimum movement. 
     In the state, as shown in FIGS. 4 a  and  5   a,  wherein the room temperature at usual times or under room-heating condition is below the predetermined temperature for the coil spring  30 , the switching bar  6   b  is engaged with the ratchet  4  under the elastic force of the leaf spring  6   a  to prevent reverse rotation of the rotation shaft  1 . At this time, the lever  6  is in the lowered position at its outer end point, suppressing the actuating piece  21  of the blocking plate  20 , and the coil spring  30  is in tension state, with its length expanded from its original form shown in FIG. 4 b.    
     As described above, in the automatic putting-out apparatus according to the first embodiment of the invention as shown in FIGS. 1 to  5   b,  ignition is caused in the state of the wick being raised in a wick case  2  by turning the rotation shaft  1  clockwise through a grip  1   a  for heating a room, and thus the room temperature rises as the combustion continues until the preset temperature for coil spring  30  is reached, when the coil spring  30  is contracted to its original state as shown in FIG. 4 b,  whereby the blocking plate  20  is turned anticlockwise to lift up the lever  6  by means of the actuating piece  21 . At this time, the operating force of the coil spring  30  is reinforced to the maximum, as the bias spring  40  changes its direction of action to agree with the coil spring  30 , as mentioned above. Thus, the locking between the switching bar  6   b  on the lever  6  and the ratchet  4  is released to turn the rotation shaft  1  anticlockwise elastically due to the biased torsional force from the torsion spring  3  mounted on the ratchet  4 , whereby the wick in the wick case  2  is lowered almost instantly to carry out putting-out. 
     On the other hand, after self putting-out is carried out due to the operation of the coil spring  6   a,  the raised lever  6  is returned to the original state under the restoring force of the leaf spring  6   a,  as shown in FIG. 5 a,  wherein the blocking plate  20 , coil spring  30  and bias spring  40  are returned to normal state, as shown in FIG. 4 a.    
     The automatic putting-out apparatus according to the second embodiment of the present invention is shown in FIGS. 6 to  10   b.    
     The parts which are shown in FIGS. 6 to  10   b  but are of the same or similar construction or function as in the first embodiment depicted in FIGS. 1 to  5   b  are given the identical numerical numbers and excepted from further explanation. 
     Particularly referring to FIGS. 7 and 8, a bracket  50  is formed at the top and bottom area on its one side with a tube securing part  51  and a spring connection  52 , is formed at a top area on its other side with a securing piece  53  for a screw S 2  to join with a frame  5 , is formed at a central position with a hole  54  for receiving a shaft pin P 2  and is formed at a central top area with an operative opening  55 . 
     A blocking plate  60  is formed at the top and bottom area on its one side with a iron wire securing part  62  and with a spring connection  63 , is formed on its other side with an actuating piece  61  for contacting the bottom face of the lever  6  and is formed at a central position with a shaft hole  64  to be located inwardly of the above-described hole  54  on the wall of the bracket  50  and used for receiving the shaft pin P 2  in assembled state. Thus, the blocking plate  60  is assembled to the bracket  50  pivotally through a shaft pin P 2 , wherein the blocking plate  60  is inserted in the operative opening  55  of the bracket  50 , with its wire securing part  62  protruding from the opening. 
     The iron wire  70  is provided at its one end with a securing means  71  to be tightly fitted in the wire securing part  62  of the blocking part  60  and at its opposite end with a spring connector  72 . 
     The tube  80  is fitted in tube caps  81  and  82  at opposite ends, wherein one tube cap  81  is placed in a tube securing part  51  formed in the bracket  50  and fixed by the help of a screw S 3 . 
     A spring housing  90  is composed of an upper body  90   a  and a lower body  90   b  through hooks  92  and hook slots  93  in a detachable manner. The lower body  90   b  is formed on one side with a tube securing groove  94  for receiving the other tube cap  82  of the tube  80  and to be secured with the help of a screw S 4  and is formed with a spring connection  95  at top of a side wall on the other side. The upper body  90   a  is formed with vents  91  on its top wall. 
     A coil spring  100 , in the state housed in the spring housing, is connected to the spring connection  95  of the spring housing  90  and the spring connector  72  of the iron wire  70  at opposite ends, wherein the construction and operation of such a spring according to this second embodiment are the same as those for the coil spring  30  in the first embodiment. 
     A bias spring  110  is connected to the spring connection  52  of the bracket  50  and the spring connection  63  of the blocking plate  60 , wherein the construction and operation of such a spring according to this second embodiment are also the same as those for the bias spring  40  in the first embodiment. 
     In the automatic putting-out apparatus according to the second embodiment of the invention as shown in FIGS. 6 to  10   b,  ignition is initiated in the state of the wick being raised in a wick case  2  by turning the rotation shaft  1  clockwise through a grip  1   a  for heating a room, and thus the room temperature rises as the combustion continues until the predetermined temperature for coil spring  30  is reached, when the coil spring  100  is contracted to its original state, pulling the iron wire  70  housed in the tube  80 , whereby the blocking plate  60  is turned anticlockwise by means of the securing means  71  to thereby lift the lever  6  through the actuating piece  61 , as the shift is represented in FIGS. 9 a  and  b.  Thus, as in the case of the first embodiment, the engagement between the switching bar  6   b  on the lever  6  and the ratchet  4  is released to turn the rotation shaft  1  anticlockwise elastically due to the biased force from the torsion spring  3  mounted on the ratchet  4 , whereby the wick in the wick case  2  is lowered almost instantly to carry out putting-out, as can be seen in FIGS. 10 a  and  b.    
     An important feature for the automatic putting-out apparatus according to the second embodiment of the invention is that the coil spring  100  is connected to the blocking plate  60  through an iron wire  70 , so that the actuating force of the coil spring  100  can be easily or flexibly transmitted to the blocking plate  60  through the iron wire  70  even in the case of a complicated construction wherein the position required for sensing the room temperature and the position suitable for installing the extinguisher are different. In that case, the iron wire  70  and tubes  80  may preferably have a suitable flexibility to be bent as required to adapt the coil spring  100  which may be located at any correct location. 
     The present invention which takes the advantage of shape-memory metal as one of its major characteristics as described above may have the following merits. 
     First, the pollution of indoor air is prevented and the safety of human body is protected from toxic gases, because the hazardous gases like CO and CO 2  can be kept in its concentration within the safe limit by automatically and rapidly shutting-off the combustion of the furnace. 
     Second, the present invention is very economical in that the present invention is of simple construction mainly based on shape-memory metal in comparison to conventional costly apparatuses employing various different components including, for example, temperature sensor, micro-switch, motor, solenoid valve and like. 
     Third, the present invention is safe and reliable in operation on the ground that it is operated in sheer mechanical manner irrespective of electric power in contrast to the types of conventional apparatuses based on electric circuit, which fail to function when power is off or at low level. 
     Fourth, the bias spring used in the present invention acts to maintain the hysteretic behavior of the coil spring below its actuation temperature and specially it exerts the force in the same direction as the coil spring made of shape-memory metal in putting-out operation at an elevated temperature. In other case, the transfer of force can be conducted easily even when the location for sensing correct temperature and the location for the putting-out device do not match. 
     It is to be understood that, while the invention was described mainly with respect to two specific embodiments, the invention is not just restricted to those embodiments and a variety of modifications and alterations would be possible to a man skilled in the art by referring to the description or drawings presented here and within the spirit of the invention and thus those modifications or alterations are to fall within the scope of the invention, which scope should be limited only by the attached claims.