SAFETY DEVICE FOR PORTABLE HEATING APPARATUS

Abstract: A portable heating apparatus comprising a burner (10) disposed at the bottom portion of a combustion cylindrical body (2), a heating container (6) containing substance that is heated when in use and placed on the top portion of the combustion cylindrical body, a fuel tank (12) for storing fuel gas to be supplied to the burner, and ignition means (8) having an ignition lever (21) for operating the burner for ignition, wherein a safety device for preventing heating of the heating container in a sealed state, a combustion safety device for preventing discharge of gas at the time of flame failure, and a tubling safety device for automatically shutting off flame when the apparatus is tumbled are provided thereon with simple constructions.

Description: This invention relates to a safety device for use with a portable heater according to the pre-characterizing part of claims 1 and 2. The heater is used for warming canned goods by the combustion of gas. A safety device of this type is shown in CH-A-341,629. The burner is in the form of a heating cartridge, which can be ignited by means of a short cable only after a hole-opening lever has been actuated. The hole-opening lever bores an opening hole into the lid of the container. During outdoor activities such as camping, a portable heater having a simple structure is considered as an appliance for easily heating water held in a container, canned goods or the like for the purpose of cooking precooked foods or making tea or coffee. Such a portable heater supports the container, the canned goods or the like, and, for instance, a fuel tank, a burner and an ignition means are arranged at the bottom of the heater. The emission and ignition of gas from the burner are carried out by the operation of an ignition lever, and heating is effected by combustion using a burner that is relatively small about the size of a gas lighter or thereabouts. In a portable heater such as previously mentioned, when a container to be heated is warmed by a burner, an internal pressure of the container body rises owing to an increase in temperature of the contents of the container if the container is heated while it is sealed. Eventually, several problems may arise which are ascribed to the rupture of the container during heating or the spewing-out of the contents of the container when the container is opened. Hence, the above prior-art-device maintains the container open to the atmosphere when being heated. The object of this invention is to provide a safety device for use with a portable heater which automatically bores a hole in a container body when the container is heated. Another object of this invention is to provide a safety device for use with a portable heater that ensures easy opening of the container and allows ignition operation to be performed only after the container is opened and also releases the container from its closed state when it is heated. These objects are achieved in accordance with the features of claims 1 and 2, respectively. A safety device for use with a portable heater according to this invention comprises a burner disposed on the bottom of a combustion cylinder; a container to be heated, disposed at an upper part of the cylinder, for containing contents to be heated when the heater is in use; a fuel tank for storing fuel gas to be supplied to the burner; an ignition means having an ignition lever which performs ignition operation of the burner; and a hole-opening lever which moves in conjunction with the ignition lever and automatically bores a vent hole for steam in an upper part of the container body. With such an arrangement, when the ignition lever is operated to ignite a burner so that the container can be heated, the hole-opening lever is operated in association with the operation of this ignition lever, whereby a vent hole is automatically bored in an upper part of the container body. Steam, or the like, produced as a result of the heating of contents is expelled from this vent hole, so that the internal pressure of the container drops. This prevents the container from being ruptured while being heated or the contents from being spewed out when the container is opened. Another safety device for use with a portable heater, according to this invention, is provided with an operation rod that extends upward along a combustion cylinder with the lower end thereof coupled to the ignition means and the upper end thereof further extended upwardly past the combustion cylinder. The safety device is arranged in such a way that the ignition of a burner is carried out in accordance with the pressing of this operation rod. The safety device is also provided with an opening member that engages with a pull tab used for opening and formed on an upper part of the container and that opens the pull tab. This opening member is arranged to enable the ignition of the operation rod to be performed in conjunction with the rise of the opening member after the container has been opened. With this arrangement, the container is opened by operating the opening member, and hence smaller force is needed to actuate an operating section when compared with a case when a pull tab is directly removed. After the container has been opened by the operation of this opening member, the ignition is effected by raising the opening member to a further extent. Hence, the container becomes opened before an ignition operation is performed. This prevents the container from being heated while being sealed, and also the implosion of the container while heated or the eruption of contents of the container when it is opened. It is desirable that the upper end of the operation rod should be arranged in a foldable manner, and that the upper end of the operation rod should be housed below the lower surface side of the opening member when the container remains out of ignition. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view showing the basic structure of a portable heater which is equipped with a safety device according to a first embodiment of this invention; Figure 2 is a partially cut-away perspective view showing one example of the appearance of the portable heater as shown in Figure 1; Figure 3 is a cross-sectional view of the chief portion of the heater that illustrates a detailed example of the structure of an ignition means of a burner; Figure 4 is a horizontal cross-sectional schematic view showing an example of structure between a combustion cylinder and a container to be heated of the portable heater; Figure 5 is a cross-sectional view showing the basic structure of a portable heater equipped with a safety device according to a second embodiment of this invention; Figure 6 is a schematic plan view showing the portable heater shown in Figure 5; Figure 7 is a cross-sectional view showing the basic structure of a portable heater equipped with a safety device according to a third embodiment of this invention; Figure 8 is a schematic plan view of the portable heater as shown in Figure 7; Figure 9 is a cross-sectional view showing the basic structure of a portable heater equipped with a safety device according to a fourth embodiment of this invention; Figure 10 is a schematic plan view illustrating the portable heater as shown in Figure 9; Figure 11 is a schematic cross-sectional view showing the basic structure of portable heater equipped with a safety device according to a fifth embodiment of this invention; Figure 12 is a plan view showing the portable heater as shown in Figure 11; Figure 13 is a perspective view showing an opening member as shown in Figure 11; Figures 14 to 17 are cross-sectional views of the chief portion of the heater that illustrate opening processes, in sequence, with the use of the opening member as shown in Figure 13; Figure 18 is a perspective view showing a modified example of the opening member; Figure 19 is a perspective view showing another modified example of the opening member; Figures 20 to 22 are perspective views showing modified examples of shape of the opening member's end as shown in Figure 18; Figures 23A - 23D are perspective views showing opening processes, in order, when the direction of mounting of the opening member is reversed with respect to a pull-tab; Figure 24 is a perspective view showing the top surface of an opening member of a safety device according to a sixth embodiment of this invention; Figure 25 is a perspective view showing the bottom of the opening member; Figures 26A - 26D are perspective views of the chief portion of the portable heater showing opening processes by means of the opening member as shown in Figure 24; Figure 27 is a schematic cross-sectional view showing the chief portion of a portable heater equipped with a safety device according to a seventh embodiment of this invention; Figure 28 is a plan view showing the portable heater as shown in Figure 27; Figure 29 is a cross-sectional view of the chief portion of the heater illustrating opening processes as shown in Figure 27; and Figures 30A - 30D are perspective views of the chief portion of the heater showing opening processes of another example of a pull-tab in sequence. BEST MODES FOR PRACTICING THE INVENTION With reference to the drawings, each embodiment of the present invention will be described hereinbelow. 〈First Embodiment〉 Figures 1 and 2 show a portable heater equipped with a safety device of this embodiment. This is an example of a safety device for avoiding closed heating by automatically boring a hole in a container to be heated upon ignition. Basically, the portable heater is composed of: a cylindrical combustion cylinder 2 with at least its upper end open; a container to be heated (canned goods) 6 fixedly housed in an upper inside of this combustion cylinder 2 with a gap 4 for the updrafting of combustion gas formed between it and the cylinder 2, and also made of a cylindrical heat-resistant container body 6 having a lid 6d in which an opening pull-tab 6c is provided on the upper end surface of the lid; a burner 10 equipped with an ignition means 8, and fixedly housed inside a lower portion of the combustion cylinder 2 for heating the container 6; and a fuel tank 12 fixed inside the lower portion of the cylinder 2 for supplying fuel to the burner 10. The container 6 stores contents 5 to be heated when the heater is in use, and the cylinder 2 is provided with an air inlet port 2a for supplying air from the outside to the burner 10 and an opening 2b which allows the ignition means 8 to be operated from the outside. The opening 2b, made on the cylinder 2 in order to allow the ignition means 8 to be operated from the outside, is provided with a window 14 that enables the verification of flames of the burner 10 from the outside and a scaled window 16 for the verification of the quantity of remaining fuel in the tank 12. The ignition means 8 of the burner 10 is also provided with an ignition lever 21 which supplies gas to the burner 10 and effects ignition. This ignition lever 21 is provided with a hole-opening lever 22 which operates in conjunction with the ignition lever. The upper end of this hole-opening lever 22 extends upwards through the gap 4, and the lever has a pointed protuberance 22a for boring purposes that is formed at a location of the lever which is opposite to the top of the container body 6c. Figure 3 shows the structure of the burner 10 and a link structure between the ignition lever 21 and the hole-opening lever 22. A housing 23 is connected to the side of the fuel tank 12 that contains pressurized gas, thereby constituting a gas chamber 24 that becomes wider upwardly. A connection hole 25 is formed on the side wall on an upper part of the tank 12 so as to be connected with the gas chamber 24. This connection hole 25 is opened and closed by bringing a valve rubber 28 on one end of a pivotal lever disposed within the gas chamber 24 to come into pressed contact with the hole. The middle of the pivotal lever 27 is rotatably supported by a fulcrum, and the other end of the lever is forced in a direction of closing of the valve by means of a return spring 29. The end of a lever pin 31 comes into contact with a surface that is opposite to this return spring 29. A gas pipe 32 is disposed on the side of the gas chamber 24 above the fuel tank 12 for supplying gas from the chamber 24 to the burner 10. The burner 10 is attached to the upper end of this gas pipe 32. A nozzle 34 with its end sharply formed is disposed at the base portion of the burner so as to be connected with an emission port 33 which is opened to the gas chamber 24. The gas pipe 32 and the burner 10 may be formed in an integrated manner. The lever pin 31 projects from the housing 23 while the end thereof is sealed by means of an O-ring 36, and the ignition lever 21 of the ignition means 8 links with this lever pin 31. In other words, the ignition lever 21 is supported by a pivotal pin 37 in a vertically pivotable manner. An operation part 21a is projected from the cylinder 2, and it remains in an operable state. A link part 21b downwardly extends from the ignition lever, and is forced in a return direction by means of a spring 38 interposed between the lever and the housing. The lower end of the link part 21b comes into contact with the end of the lever pin 31 when the ignition lever 21 is rotated downwards, thereby thrusting the lever pin 31 into the housing. Although a specific structure is not illustrated, a lock mechanism is arranged to maintain the thrusting action of the lever pin 31 and the opening action of the pivotal lever 27 during ignition and combustion. Similarly, though a specific structure is not illustrated, a discharge electrode or the like is disposed to cause the burner 10 to be ignited by electric discharge by the operation of a piezoelectric unit in conjunction with downward rotations of the ignition lever 21. An engaging protuberance 21c is formed on the ignition lever 21 above the pivotal pin 37, and this protuberance 21c meshes with a lower end engaging part 22b of the hole-opening lever 22. The hole-opening lever 22 is supported by a pin in a rotatable fashion, and is arranged in such a manner that when the engaging protuberance 21c of the ignition lever 21 comes into contact with the lower end engaging part 22b, the lever 22 rotates, and the upper end protuberance 22a is forced against the side surface of an upper part of the container body 6c to bore a vent hole in the body 6c. The gap 4 is established between the container body 6c of the container 6 and the combustion cylinder 2 for the updraft of combustion gas, and the structure for forming this gap 4 also serves as a means for fixing the cylinder 2 and the body 6c. Specifically, as seen from a horizontal cross section of Figure 4, a corrugated partition plate 9 that longitudinally extends is sandwiched between the cylinder 2 and the body 6c, and corrugated inner spacing 9a of the corrugated plate 9 serves as the gap 4 for the updraft of combustion gas. The operation of the embodiment set forth above will now be described. When combustion is started with the use of the burner 10 to heat the container 6, the operation part 21a of the ignition lever 21 is pressed. The link part 21b of the lever thrusts the lever pin 31 into the housing, which causes the pivotal lever 27 to rotate against the return spring 29. Then, the valve rubber 28 is separated from the connection hole 25, and fuel is supplied to the gas chamber 24 from the fuel tank 12. Fuel within this chamber 24 is emitted from the burner 10 via the emission port 33, the nozzle 34 and the gas pipe 32. Combustion is effected by the ignition of this discharged gas, and the container body 6c is directly heated from underneath by flames which are being discharged. The lower end of the partition plate 9 extends downwards past the bottom of the container body 6c, and hence hot air produced by flames from the burner 10 flow upwards solely along the inner spacing 9a that faces the peripheral wall of the body 6c. Thus, the container 6 is efficiently heated, and ambient air flows through a spacing 9b, thereby suppressing a rise in temperature of the outside of the combustion cylinder 2 and hence facilitating the handling of the same. Moreover, the corrugated partition plate 9 serves to keep the contents 5 warm after the heating of the contents within the container 6 has been completed. Concurrently with the supply of fuel and ignition, the engaging protuberance 21c engages with the engaging part 22b of the hole-opening lever 22 in accordance with the ignition operation of the lever 21, that is, the rotation of the lever 21. This causes the hole-opening lever 22 to rotate and automatically bore a vent hole in the container body 6c. Thus, a rise in internal pressure caused by heating is suppressed by expelling vapor or the like through the vent hole. When a flame is extinguished, the lever pin 31 is caused to protrude, whereby the pivotal lever 27 rotates under the thrusting force of the return spring 29. This causes the valve rubber 28 to close the connection hole 25, and hence the emission of gas is stopped. Thus, the combustion by the burner 10 is completed. In the previous embodiment, a governor mechanism may be incorporated into the heater for regulating in such a manner that the pressure of supplied gas becomes substantially constant even when temperature varies. For instance, a diaphragm should preferably be disposed in such a way as that the pivotal lever 27 causes the diaphragm to be closed when the pressure of the gas chamber 24 rises but to be opened in accordance with a pressure drop. Instead of the mechanism for opening and closing the supply of gas by the operation of the pivotal lever 27 in the previous embodiment, a valve mechanism for closing and opening the supply of gas may be disposed at the nozzle 34, and may be linked in such a fashion that the valve mechanism is operated and opened in accordance with the ignition operation of the ignition lever 21. In that case, the pivotal lever 27 will be omitted, or will be arranged to cause the connection hole 25 to be opened or closed in accordance with pressure with the help of a governor mechanism. 〈SECOND EMBODIMENT〉 This embodiment is a modified example of the first embodiment, and is illustrated in Figures 5 and 6. This example relates to a safety device arranged such that a pull-tab is opened in conjunction with an ignition operation, thereby rendering a container to be heated unsealed. A container to be heated 6 in this embodiment is provided with a pull-tab 6a located at the center of a lid 6b of a container body 6c. A burner 10 and a fuel tank 12 are arranged in the same manner as in the previous embodiment, an ignition means 8 for igniting the burner is provided with an ignition lever 41 that operates a valve mechanism 40 for closing and opening the supply of gas to the burner 10 and also effects ignition. A hole-opening lever 42 is disposed which is connected with this ignition lever 41. the hole-opening lever 42 has a rod part 42a with its lower end connected to the ignition lever 41 and extending upwards through a gap 4. This rod part 42a is pivotable coupled with a lever part 42c that extends in a direction of the center of the container 6 over the same via an upper end coupling part 42b. A lever-shaped end part 42d of the lever part 42c is interposed between a lower side of the pull-tab 6a and the lid 6b. With the arrangement of this embodiment, ignition operation caused by the pressing of the ignition lever 41 cause the rod part 42a and the coupling part 42b of the lever part 42c to be pulled downwards. Thereby, the end part 42d causes the pull-tab 6a to be pulled up, and a vent hole is automatically opened together with the ignition operation. 〈Third Embodiment〉 This embodiment is a modified example of the first embodiment, and is shown in Figures 7 and 8. This example relates to a safety device that renders a container to be heated unsealed by boring a vent hole in a lid 6b together with ignition operation. As with the previous embodiment, an ignition means 8 in this embodiment is provided with an ignition lever 41 that operates a valve mechanism 40 and effects ignition. A hole-opening lever 44 is disposed which is connected with this ignition lever 41 for boring a hole in a container to be heated 6. The hole-opening lever 44 has a rod part 44a with its lower end connected to the ignition lever 41 and extending upwards through a gap 4. An upper end part 44b is bent in a direction of the center of the lid 6b above the same. An end part 44c is bent downwards, and is pointed. With the arrangement of this embodiment, ignition operation caused by the pressing of the ignition lever 41 cause the rod part 44a of the opening lever 44 to be pulled downwards. This causes the end part 44c to pressed against the lid 6b, thereby automatically boring a vent hole. 〈Fourth Embodiment〉 This embodiment is another modified example of the first embodiment, and is shown in Figures 9 and 10. This example relates to a safety device that renders a container to be heated unsealed by boring a vent hole in a lid 6b together with ignition operation. As with the previous embodiment, an ignition means 8 in this embodiment is provided with an ignition lever 41 that operates a valve mechanism 40 and effects ignition. A hole-opening lever 46 is disposed which is connected with this ignition lever 41 for boring a hole in a container to be heated 6. The hole-opening lever 46 has a rod part 46a with its lower end connected with the ignition lever 41 and extending upwards through a gap 4. A lever part 46c, extending to the opposite end of the container 6 over the same, is connected to the upper end of the hole-opening lever in a pivotable manner via a coupling part 46b. An end part 46d of the lever part 46c is engaged with a joined part between a lid 6b and a container body 6c. A pointed protuberance 46e for boring purposes is formed on the lower surface to the inside of the lever part 46c at a distance from this end part 46d. With the arrangement of this embodiment, ignition operation caused by the pressing of the ignition lever 41 cause the rod part 46a of the hole-opening lever 46 and the coupling part 46b of the lever part 46c to be pulled downwards. This causes the lever part 46c to rotate around the end part 46d that acts as a fulcrum and, also, the protuberance 46e to be pressed against the lid 6b, thereby automatically boring a vent hole. In the foregoing embodiments 1 through 4, the design of the ignition levers 21 and 41 can be appropriately changed to a laterally pivotable type as well as a longitudinally pivotable type, a rotatable type, a press type or the like. In response to this, the design of a mechanism for closing and opening the supply of fuel, an ignition mechanism and a link mechanism with the hole-opening levers 22, 42, 44 and 46 are varied. 〈Fifth Embodiment〉 Figures 11 and 12 illustrate a portable heater equipped with a safety device of this embodiment. This embodiment relates to an example of a safety device that enables an ignition operation after a container to be heated having an opening member has been opened, and this avoids heating while the container is sealed. The portable heater is made up of a cylindrical combustion cylinder 102; a container 106a fixedly housed in an upper inside of this combustion cylinder 102 with a gap 104 formed between the container and the cylinder, and also composed of a cylindrical heat-resistant container body 106c having a lid 106a in which an opening pull-tab 105 is formed on the upper end surface of the lid; a burner 110 fixedly housed within a lower inside of the cylinder 102, and equipped with an ignition means 108; and a fuel tank 112. The base of the opening pull-tab 105 is fixed to the center side section of an opening flap 106b formed by stamping a cut line on the lid 106a. When a ring portion of the pull-tab 105, extending in a direction opposite to the opening flap 106b, is raised, the center side section of the flap 106b is also raised and separated. Then, a small hole is opened, and the container is also opened. Further raising of the pull-tab 105 causes the pull-tab and the opening flap 106b to be separated from the lid 106a, thereby opening an outlet port for the contents of the container. There is another known structure for the shape of the pull-tab 105 and the flap 106b. An opening member 115 that engages with the pull-tab 105 and opens the container by raising the pull-tab 105 is also provided on the top of the lid 106b of the container 106. As shown in Figure 13, this opening member 115 comprises a lever section 116 which extends in the form of a stick; a connection leaf 118 connected to the lever section 116 and having an engagement section 117 which engages with the pull-tab 105; an operation section 116a formed on one end of the lever for affording a hold for a finger when pull operation is carried out. Concretely, the lever section 116 is made of a plate member (for instance, a metal plate), and has a length that is slightly shorter than a bore diameter of the upper end outer periphery of the container 106 and a width that is slightly wider than that of the pull-tab 105. Both sides of the opening member are bent downwards to form side walls 116b. Both ends of the opening member are formed into an arc. A circular finger hold aperture 119 is opened in the vicinity of one of the ends, that is, the operation section 116a. In the meantime, the base of the connection leaf 118 is supported in a rotatable fashion by a pin 120 that is arranged at substantially the center position opposite to the operation section 116a and in a direction orthogonal to the longitudinal direction of the operation section. The end of this connection leaf 118 is cylindrically curled to form the engagement section 117. This engagement section 117 engages with the pull-tab 105 in a rotatable fashion. An insertable opening is also formed on the area of the lever 116 that corresponds to the connection leaf 118. The ignition means 108 of the burner 110 is provided with an ignition lever 125 for supplying gas to the burner 110 and effecting ignition. An operation rod 126 is connected with this ignition lever 125 with one end of the rod projecting upwards along the side of the container 106. The ignition lever 125 is provided with a first arm 127 and a second arm 128, both arms pivotally moving in conjunction with the pivotal operation of the ignition lever. The first arm 127 is caused to be closed and opened in conjunction with a nozzle member 129 of a valve mechanism which controls the supply of gas from the fuel tank 112, whereas the second arm 128 causes a piezoelectric ignition unit 130 to be actuated. The nozzle member 129 is opened and actuated in accordance with the pressing of the ignition lever 125, so that fuel gas is supplied to the burner 110. A discharge voltage is applied from the ignition unit 130 to a non-illustrated discharge electrode, thereby effecting ignition and combustion. On the other hand, the lower end of the operation rod 126 is connected to the end of the ignition lever 125, and the upper end of the same extends upwards through the gap 104. When the ignition lever 125 is situated at its upper position (a non-operation position), that is, the operation rod 126 locates at its upper position, the end 126a is arranged on the top of the container 106 in a foldable manner. The end 126a is forced to stand upright, namely straight, by means of a non-illustrated spring. A stopper mechanism is also provided to maintain the end in this straight state. When the container 106 is kept in a preserved state, the end 126a of the rod 126 is fixedly folded away on the opening member 115. The thrust of the operation rod 126 connected to the ignition lever 125 causes the ignition operation to be performed. A triangularly corrugated partition plate 109, which extends longitudinally, is interposed between the combustion cylinder 102 and the container body 106c. The inner wave-shaped spacing 109a of this corrugated partition plate 109 serves as a gap 104 for the updraft of combustion gas. The operation of the above embodiment will now be described. When the container is in a preserved state as shown in Figures 11 and 12, the opening member 115 is mounted flat on the top of the container 106. The engagement section 117 of the opening member engages with the pull-tab 105, and the end 126a of the rod 126 of the ignition means 108 is folded flat and stored. When the container 106 is heated, the operation section 116a of the lever section 116 of the opening member 115 is raised using the finger hold 119, thereby raising the lever 116. At this time, the end 126a of the rod 126 of the ignition means 108 is released from its fixed state, and hence stands upright. As shown in Figure 14, further raising of the lever 116 brings its end into contact with the outer periphery of the top surface of the lid 106a, thereby causing the lever to be pivoted around this contacted point. This causes the engagement section 117 of the connection leaf 118 to raise the pull-tab 105, and hence the center of the opening flap 106b is raised, thereby opening a small hole. Subsequently, as shown in Figure 15, when the lever 116 is raised until it stands substantially upright, the pull-tab 105 is further raised, and the connection leaf 118 comes into line with the pull-tab 105. Thus, both the leaf and the pull-tab become fully extended. When the lever 116, thus standing upright, is folded away from the container, the lever 116 pivots about a connection point between the connection leaf 118 and the lever, that is, the pin 120. Then, the end of the lever which is opposite to the operating section 116a travels toward the center of the lid 106a over the same. The following half pivotal movement of the lever causes the end 126a of the rod 126 to come into contact with the vicinity of the center on the upper surface side of the lever 116. As shown in Figure 17, this thrusts the operation rod 126, and the down-thrust of this operation rod 126 causes the ignition lever 125 of the ignition means 108 to pivot, thereby causing gas to be discharged from the burner 110 and to be ignited. Thus, it is arranged that several operations, namely, the raising of the opening member 115, the raising of the pull-tab 105 and the opening of the container 106 by the hinging of the opening member to the front, and the ignition of the burner 110 are successively and dependently performed, thereby preventing the heating of a container while it is sealed. Figure 18 shows a modified example of the opening member of the fifth embodiment. In the opening member 115 of the fifth embodiment mentioned above, the operation section 116a of the lever section 116 is provided with the finger hold aperture 119. In an opening member 121 of this example, one end of the lever 116 is formed to extend outside past the upper edge of the container body 106c, thereby constituting an operation section 116a which has a part, extending from the container body 106c, to be held and raised by a finger from its lower side. Notches 116c to be engaged with the brim of a can are formed on the side walls 116b to the inside of the operation section 116a. The connection leaf 118 of the lever 116 is formed in the shape of a strip by stamping the lever 116 with nicks. A connection part serves as the center of the pivotal movement of the connection leaf 118, thereby rendering the pin 120 used in the foregoing embodiment unnecessary. The width of the lever 116 is smaller than that of the lever used in the foregoing embodiment, and clearance grooves 116d are formed on the side walls 116b to avoid interference with the pull-tab 105. Figure 19 shows another modified example of the opening member. In an opening member 122 of this example, the connection leaf 118 having the engagement section 117 is formed separately from the lever 116. A base of the leaf is connected to, and supported by, the pin 120 in a rotatable fashion at substantially the center of the lever 116 on the rear surface of the same. The rest of the opening member is structurally the same as the member shown in Figure 18. Figures 20 - 22 respectively show modified examples of the shape of the end of the opening member 121 as shown in Figure 18. In the example shown in Figure 20, ends 116e of the side walls 116b are rounded. Similarly, in the example shown in Figure 21, the ends 116e of the side walls 116b are rounded, and the end of the lever 116 is formed into a concavely curved surface 116f. Moreover, in the example shown in Figure 22, the end of the lever 116 is formed into a convexly curved surface 116g. In any event, the opening member 121 is improved in operability when the member is raised and folded away from the container. The opening member is arranged in such a manner that the engagement of the member with the outer brim of the lid 106a of the container 106 and the sliding of the member over the upper surface of the lid can be improved. Even in other examples, the shape of the end of the opening member can be modified, if necessary. On the other hand, Figure 23 shows a case where the opening member 122 is attached in a direction, which is opposite to that in the above examples, with respect to the pull-tab 105. The connection leaf 118 is folded away towards the operation section 116a, and then the engagement section 117 engages with the pull-tab 105. As shown in Figures 23A - 23D, a container is opened by the similar operation to the previous examples, and the ignition operation of a non-illustrated operation rod is carried out. The size of an opening in the container that is made when the opening member 122 is raised becomes large. 〈Sixth Embodiment〉 This embodiment is a modified example of the fifth embodiment. This embodiment relates to an example of a safety device which enables an ignition operation, as shown in Figure 26, after a container to be heated has been opened with the use of an opening member shown in Figures 24 and 25. An opening member 135 of this embodiment engages with the pull-tab 105 in a slidable fashion. The member is made of a plate member (for example, a metal plate). A lever section 136 has a length which is slightly shorter than the bore diameter of the upper end outer periphery of the container 106, and has a width which is slightly wider than that of the pull-tab 105. Both sides of the member are bent downwards to form engagement sections 137. These engagement sections 137 engage with both sides of the pull-tab 105. One end of the engagement sections 137 is left open, and the other end thereof is provided with a removal stopper 137a. Front and back ends of the lever 136 are slightly bent upwards. One end of the opening member where the removal stopper 137a is provided is formed into a thrust section 136a for sliding purposes. The other end of the opening member is formed into an operation section 136b for raising purposes. As shown in Figure 26A, the opening member 135 as set forth above is fitted inside the periphery of an upper part of the container 106 by inserting the pull-tab 105 of the container 106 into the engagement sections 137 from the open side of the opening member (from the operation section 136b), so that the engagement sections engage with the pull tab. The operation rod 126 of the ignition means 108 as constituted in a similar manner to the previous embodiment is disposed so as to locate at an extended part of the operation section 136b of the opening member 135. The end 126a is folded and engagedly inserted between the lower surface of the operation section 136b and the lid. The operation of this embodiment will now be described with reference to Figure 26. When the container 106 is heated from its preserved state as mentioned above, the thrust section 136a of the lever 136 of the opening member 135 is slid towards the center when it is pressed. This causes the operation section 136b at one end of the opening member 135 to project outside over the upper brim of the container body 106c. The pull-tab 105 is held at the end of the opening member by means of the removal stopper 137a of the engagement sections 137. Subsequently, as shown in Figure 26c, when the lever section 136 starts being raised by pulling the operation section 136b upwards, the pull tab 105 engaging with the other end of the lever is also raised by the engagement section 137. This causes the center of the opening flap 106b to be separated, thereby producing a small hole. At this time, the end 126a of the rod 126 of the ignition means 108 is disengaged from the opening member 135, and hence stands upright. After the container body 106c has been opened, the opening member 135 is horizontally pressed down in a manner opposite to the previous procedures. This brings the back surface of the lever 136 into contact with the end 126a of the rod 126. The thrust of this operation rod 126 causes the ignition lever 125 of the ignition means 108 to pivot in accordance with the pressing of this operation section 126b, thereby causing gas to be discharged from the burner 110 and ignited. As mentioned above, the raising of the pull tab 105, the opening of the container 106 and the ignition of the burner 110 are successively and associatedly carried out by the sliding, raising and returning of the opening member 135, thereby preventing the heating of the container while it is sealed. 〈Seventh Embodiment〉 This embodiment is another modified example of the fifth embodiment, and is shown in Figures 27 to 29. This embodiment relates to an example having a different link structure disposed between the opening member and the operation rod. An opening member 145 of this embodiment has a lever section 146. A connection leaf 148 is connected to the lever section 146 by a pin 120 in a rotatable fashion, and an end engagement section 147 of the leaf engages with a pull tab 105. One end of the lever section is formed into an operation section 146a. An end foldable section 141a of an operation rod 141 is disposed in a foldable fashion around a fulcrum. Bifurcated ends of the foldable section are bent downwards, and held below an end 146b of the lever 146 that is opposite to the operation section 146a. A sleeve 142 is fitted around the shaft of the operation rod 141, and is forced upwards by means of a spring 143 disposed below the sleeve. This sleeve 142 causes the end foldable section 141a to stand and be held upright. In other words, when the operation section 146a of the opening member 145 is pivoted so that it can be raised from its folded state as shown in Figures 27 and 28, the container is opened by raising the pull-tab 105 in a similar manner to the previous embodiments. Accordingly, as the end 146b of the opening member travels towards the center over the lid 106a, the end 146b is disengaged from the foldable section 141a of the operation rod 141. As shown in Figure 29, the elevation of the sleeve 142 owing to the spring 143 causes the foldable section 141a to stand upright. The sleeve 142 is positioned around the outer periphery of the fulcrum of the rod, thereby maintaining the foldable section 141a in an upright state. Further folding of the opening member 145 causes the operation rod 141 to be pressed, thereby effecting ignition. Figure 30 shows an example of the opening of a container to be heated which is arranged in such a manner that a pull-tab, as employed in the fifth - seventh embodiments, is not separated from a lid. In this embodiment, the opening member 135 (which is slightly different in structure from the original.) of the sixth embodiment is used. Namely, a pull-tab 150 of this embodiment is arranged in such a way that the tab is once raised to open an opening flap 160b, and then the tab 150 is horizontally folded. The opening member 135 is slid and engaged with the pull-tab 150. The end 141a of the operation rod 141 is folded flat and held between the rear side of the operation section 136b of the lever 136 and the lid while the end engages with the operation section (see Figure 30B). The opening operation of the container is the same as the container as shown in Figure 26. The container is opened by raising the operation section 136b, and hence the end foldable section 141a of the operation rod 141 is disengaged from the operation section, and stands upright. Simultaneously, ignition is effected by the following thrust of the foldable section to a horizontal level.

Claims: A safety device for use with a portable heater, including a burner (10), a container (6) to be heated for storing contents which are heated when the heater is in use and an ignition means (8) for igniting the burner (10) and a hole-opening lever (22, 44, 46) which automatically bores an exhaust hole for vapor or the like in an upper part of the container body (6b, 6c), characterized in that said burner (10) is disposed at the bottom of a combustion cylinder (2), said container (6) to be heated is disposed in an upper part of the combustion cylinder (2), a fuel tank (12) stores fuel gas to be supplied to the burner (10), said ignition means (8) has an ignition lever (21, 41), and said hole-opening lever (22, 44, 46) moves in conjunction with the ignition lever (21, 41) which ignites the burner (10) and also automatically bores said exhaust hole. A safety device for use with a portable heater, including a burner (10, 110), a container (6, 106) to be heated for storing contents which are heated when the heater is in use and an ignition means (8, 108) for igniting the burner (10, 110) and an opening member (42d, 115, 121, 122, 135) for opening the container (6, 106), characterized in that said burner (10, 110) is disposed at the bottom of a combustion cylinder (2, 202), said container (6, 106) to be heated is disposed in an upper part of the combustion cylinder (2, 202), a fuel tank (12, 112) stores fuel gas to be supplied to the burner (10, 110), the ignition means is disposed in the vicinity of the burner and causes the ignition of gas from the burner, an operation rod (42, 126, 141) extends upwards along the combustion cylinder (2, 102) with its lower end connected to the ignition means (8, 108) and the upper end extending upwards past the combustion cylinder (2, 102), wherein the pressing of the operation rod (42, 126, 141) causes the ignition means (8, 108) to be actuated and also causes the burner (10, 110) to be ignited, said opening member (42d, 115, 121, 122, 135, 145) is engaged with an opening pull-tab (6a, 105) on the top of the container (6, 106) and causes the pull-tab (6a, 105) to be opened and the operation rod (42, 126, 141) effects an ignition operation in conjunction with the raising and hinging of the opening member (42d, 115, 121, 122, 135, 145) after the container (6, 106) has been opened. A safety device as defined in Claim 2, wherein the upper end (42c, 126a, 141a) of the operation rod (42, 126, 141) is arranged in a foldable fashion and is housed below a lower surface side of the opening member (42d, 115, 145) before opening when ignition is not effected. A safety device as defined in Claim 2 or 3, wherein one end of the opening member (42d) comes into contact with an upper surface (6b) of the container (6) when opening the container (6), and serves as a fulcrum. A safety device as defined in Claim 2 or 3, wherein the opening member (135) is constituted in such a manner that it is engaged with both sides of the pull-tab (105) in a slidable fashion.

Inventors: KAGA YOSIMITU, MIFUNE HIDEO, NITTA TOMIO, SEKI MASATO, SERIZAWA NORIYUKI, KAGA, YOSIMITU, MIFUNE, HIDEO, NITTA, TOMIO, SEKI, MASATO, SERIZAWA, NORIYUKI, KAGA, YOSIMITU, MAIN FACTORY, TOKAI CORPORATION, MIFUNE, HIDEO, MAIN FACTORY, TOKAI CORPORATION, NITTA, TOMIO, MAIN FACTORY, TOKAI CORPORATION, SEKI, MASATO, MAIN FACTORY, TOKAI CORPORATION, SERIZAWA, NORIYUKI, MAIN FACTORY, TOKAI CORPORATIO
Applicants: TOKAI CORP, TOKAI CORPORATION
Application year: 1993
Main classification: A47J36
IPC codes: B65D81, A47J36