Abstract:
A carbon dioxide cartridge is triggered when a lance with a piercing tip punctures its burst disc. The cartridge has a cap that has an outlet and a passage for the lance and puncturing tip to travel. The lance is pushed into the burst disc when a heat expanding substance which is stored hermetically the cap in such a way that the only direction to expand is to displace and push the lance right into the burst disc. Once the burst disc is pierced, the cartridge empties its contents quickly out the outlet. In at least one embodiment the cartridge and the cap are attached by screw threads.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This Application is a Divisional Application claiming priority from a U.S. Utility Application having Ser. No. 11/344,322 filed Feb. 1, 2006 now U.S. Pat. No. 7,703,640. 
    
    
     FEDERALLY SPONSORED RESEARCH 
     Not applicable. 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not applicable. 
     FIELD OF INVENTION 
     The present invention relates to the field of portable compressed gas cartridge dispensers comprising heat-actuable pressure relief systems. 
     BACKGROUND OF THE INVENTION 
     Hereinafter, a compressed gas cartridge will be referred as a cgc. 
     Many people use compressed gas dispensers daily in a variety of applications such as medical, commercial and domestic. Common uses of such a dispenser are for use in the medical industry. Exemplary medical industry devices include: pneumatic inflation, cryogenic-related devices, pneumatic staple devices and dry powder and wet inhalers. 
     Good hospital hygiene practices frequently include incineration of used disposable medical devices in order to minimize the hazards of infectious waste. CGC&#39;s, particularly those filled with compressed carbon dioxide or nitrous oxide retain in the range of 700 to 900 psi, depending on room temperature. Introduced heat quickly raises cgc pressure. For example, raising a cgc of carbon dioxide to 140 degrees Fahrenheit increases the cgc pressure to about 3400 psi while a cgc of carbon dioxide at 160 degrees Fahrenheit yields about 4200 psi. These temperatures/pressures exceed cartridge manufacture&#39;s specified safe temperature range and have now become a dangerous pressure vessel waiting to violently explode. Typically, a steel cgc will not gradually release high pressure because the cartridge sealing cap is welded into place to form an all metal sealed pressure vessel. Instead, the sudden release of pressure upon explosion causes the cgc to become a projectile, randomly sending shrapnel into the air, and creating dangerously high decibel noise, capable of permanently damaging one&#39;s ears. 
     Some incinerators are armored to protect personnel and equipment should a full cgc accidentally be added to the furnace. Incinerator temperatures can quickly bring a cgc temperature up to dangerous levels in minimal time, perhaps within seconds of introduction to the heat. 
     There are many commercial and domestic uses of cgc&#39;s and a few exemplary applications include: tire inflation, portable pneumatic tool applications, actuators—by heat, manual, electronic, and other methods, air guns, life preserver inflation, aircraft redundant pneumatic systems, and more. 
     Some of these applications are potentially subjected to intense heat that could result in dangerous explosion of a cgc thus causing user injury and property damage. For example, a cyclist may leave a cgc dispenser in a car on a hot day with the windows rolled up. CGC&#39;s can, and do, occasionally rapidly explode in a hot vehicle which is overall, an undesirable event. A portable pneumatic tool may be left out in the sunlight for a period of time. The intense heat buildup can cause a cgc to reach dangerous temperatures. 
     In summary, there has been a long felt need for a safety feature that prevents a cgc from reaching dangerously high pressures should a cgc be subjected to high heat while installed in a dispenser head. 
     Two distinct types of cgc&#39;s are currently common—threaded neck portion and non-threaded neck portion. Many current art compressed gas dispensers, particularly the models manufactured by Genuine Innovations, Inc. in Tucson, Ariz. U.S.A. are manufactured to dispense a non-threaded neck compressed gas cartridge, dispense a threaded neck compressed gas cartridge, or capable of dispensing both species within the same dispenser. 
     One feature of current art compressed gas dispensers is a lance housing that has been used in part to contain the high pressure from a compressed gas cartridge. Historically, lance housings have been manufactured from metal such as brass. A lance housing also provides an excellent recess or pocket for a seal that is used to contain the compressed gas in a lanced cartridge and studying the prior-art exemplifies many methods of virtually accomplishing the same sealing result. A lance housing can feature internal threads that are used to mate with a compressed gas cartridge also exhibiting a threaded neck portion and a lance housing sometimes exhibits no threads to mate with a compressed gas cartridge and can accept only non-threaded varieties. 
     U.S. Pat. No. 6,843,388 by Hollars titled Compressed gas cartridge dispensing system allowing interchangeable use of different capacity compressed gas cartridges and novel storage feature teaches some methods of how a non-threaded neck compressed gas cartridge can be dispensed as well as teaches an additional method of how a threaded neck compressed gas cartridge can be dispensed. Additionally, the terminology from the 6,843,388 patent is carried over into this application in an effort to maintain consistency for each of understanding. 
     The preferred embodiment and alternative embodiments will be exemplified in the following paragraphs and in the FIGS. The following embodiments will describe the afore-mentioned prior-art and the present invention. Additionally, with the aid of figures, one skilled in the art will be able to understand and appreciate the scope of the exemplary embodiments to follow. 
     OBJECTS AND ADVANTAGES 
     Accordingly, several objects and advantages of the present invention will be presented in the following paragraphs followed by a thorough disclosure of each aspect in the accompanying embodiments in the DETAILED DESCRIPTION. 
     In light of the above-mentioned problems, it is therefore an object of the present invention to provide a simple method of manufacturing a compressed gas dispenser featuring a reliable heat-actuable pressure discharge feature. 
     Additionally, another object of the present invention is to provide a cgc dispenser having means for a flame-actuable pressure discharge feature. 
     It is another object of the present invention to utilize as little metal as possible in a lance housing and incorporate as many features and components as possible out of injection moldings, particularly for affordable manufacturing reasons and reduced components. 
     Further objects and advantages will become apparent in the following paragraphs. Solely and in combination, the above objects and advantages will be illustrated in the exemplary figures and accompanying embodiments to follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The figures are exemplary of different embodiments of the present invention. Each illustration conveys the invention and is not to be considered as limiting, rather, exemplary to the scope and spirit of the present invention. Like components in the figures share identical numbering. 
         FIG. 1A  illustrates a partial cross-section view of part of an exemplary compressed gas cartridge dispenser comprising a heat and/or flame actuable pressure discharge puncturer in a first position, in accordance with an embodiment of the current invention; 
         FIG. 1B  illustrates a partial cross-section view of part of an exemplary compressed gas cartridge dispense comprising a heat and/or flame actuable pressure discharge puncturer in a second position, in accordance with an embodiment of the current invention; 
         FIG. 1C  illustrates a partial cross-section view of part of an exemplary compressed gas cartridge dispenser comprising a heat and/or flame actuable pressure discharge puncturer in a third position, in accordance with an embodiment of the current invention; 
         FIG. 2  illustrates a partial cross-section view of part of an exemplary compressed gas cartridge dispenser comprising a heat expandable pressure discharge puncturer, in accordance with an embodiment of the current invention; 
         FIG. 3A  illustrates a partial cross-section view of part of an exemplary compressed gas cartridge dispenser comprising a heat expandable pressure discharge puncturer in a first position, in accordance with an embodiment of the current invention; 
         FIG. 3B  illustrates a partial cross-section view of part of an exemplary compressed gas cartridge dispenser comprising a heat expandable pressure discharge puncturer in a second position, in accordance with an embodiment of the current invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following paragraphs will detail several modes including the best mode of the present invention. The exemplary figures and description of the invention as it is exemplified in each figure is representative of the current invention and the scope of the invention disclosure is not intended to be limited by the exemplary teachings. One skilled in the pertinent art realizes that the embodiments to follow may reasonably be combined and/or modified without deviating from the intended spirit of the present invention. Like physical structure in different figures share the same identifying numbers. 
       FIG. 1A  illustrates a partial cross-section view of part of an exemplary compress gas cartridge (cgc) dispenser  100  in a first position comprising a non-threaded cgc functionally situated in a cgc dispenser, in accordance with the present invention. A cgc  105  situates within a lance housing  106  comprising a cgc seal  115  capable of retaining the pressure contained within a cgc upon harnessing in cgc dispenser  100 . Exemplified in a cgc dispenser body  110  is a floatable cartridge piercing lance  125  featuring a rigid pierce tip  126 . A piercing lance seal  120  circumferentially situates around cartridge piercing lance  125  and maintains piercing lance  125  in position. Not illustrated in this exemplary figure is a cgc retainer commonly referred to as a cgc cup. A cgc cup maintains cgc  105  in position with cgc dispenser  100 . Typical attachment means for cgc cup to cgc dispenser is a threadable connection and can be seen in may exemplary reference works such as in U.S. Pat. No. 6,843,388 to Hollars, filed Jul. 22, 2002. 
     Also contained within cgc dispenser  100  is a lance hammer  135  situated within a hammer bore  136  that is an integral feature within cgc dispenser body  110 . A hammer spring  140  centers around lance hammer  135  and is exemplified in a compressed position in  FIG. 1 . A beveled retaining feature  150  coexists between the top end of lance hammer  135  and a hammer retainer  145 . Preferably, beveled retaining feature  150  is angled to approximately 45 degrees for both mating components. 
     A tensile line  155  retains hammer retainer in position with lance hammer  135 . Preferably, tensile line  155  is comprised of a monofilament or braided element composition. Such exemplary line compositions can be nylon monofilament or polyethylene braided. Tensile line  155  wraps around and/or is retained by a protrusion  160 . 
     A flame or high heat introduced to tensile line  155  will quickly allow line failure thus allowing lance hammer  135  to travel along hammer acceleration zone  130  thus ultimately striking cgc lance  125  and driving into cgc  105 . 
     A user is capable of manually lancing a cgc upon breaking tensile line  155  through heat or cutting or by applying an in-line puncturing force  199  ( FIG. 1B ) onto protrusion  160  thus shifting hammer retainer  145  such that lance hammer  135  is no longer retained by beveled retaining feature  150 . In exemplary  FIG. 1 , actuation hardware is not illustrated, rather illustrated with arrows, and can be comprised of simple fulcrumbed thumb levers to solenoid actuators or any complexity device in between. 
       FIG. 1B  illustrates dispenser  100  in a second position such that piercing lance  125  has punctured cgc  105 . A lanced cgc releases pressurized gas, driving piercing lance away from cgc  105  (shown in  FIG. 1C  as a third position) allowing compressed gas out through an exit port  165  that fluidly connects to any device or attachment desired in connection. 
     Even though a non-threaded compressed gas cartridge is exemplified in  FIG. 1 , a slightly different embodiment not illustrated is a cgc having a threaded neck portion adaptable to such a dispenser. The lance housing would be threaded in this embodiment thereby not requiring use of a cartridge-retaining container. 
       FIG. 2  illustrates a partial cross-section view of part of an exemplary compressed gas cartridge dispenser  200  comprising a heat expandable pressure discharge puncturer, in accordance with an embodiment of the current invention. Illustrated in this embodiment is a threaded neck portion cgc  205  threaded into a threaded lance housing  206  located distally at a cgc dispenser body  210 . A piercing lance seal  220  abuts the puncturable face of cgc  205 . A cgc lance  226  situates within a lance driver  235  that is allowed to translate within a driver bore  236  that is an integral feature of cgc dispenser body  210 . A lower lance driver seal  227  and an upper lance driver seal  228  maintain lance driver  235  in place as well as providing sealing on each end. A cgc dispenser cap  250  is shown threadably attached to cgc dispenser body  210 . A reservoir  245  is contained by cgc dispenser cap  250  and is sealed from leaking by a cap seal  240 . 
     Certain application may benefit from a slower reacting, heat-actuable pressure release system. Intuitively, this embodiment is probably slower to respond to a heat application than the embodiment illustrated in  FIG. 1 . As reservoir  245  melts from high heat, the wax expands thus driving lance driver  235  toward cgc  205 . Current technology in the wax actuation industry allows one to dope the paraffin so that it melts (and expands) and a predictable temperature. Two common terms for this type of actuator can be a wax motor or thermoactuator and has seen great success in appliance applications among other industries. 
     Also in accordance with an embodiment of the present invention, the wax actuator can be combined with a heat source. A temperature sensor can provide an actuation means, either mechanical or electrical, to a switch that can heat the paraffin quickly through battery/resistance, chemical, environmental, or other means. 
     An additional embodiment of the present invention combines the spring biased lance hammer mechanism similar to that exemplified in  FIGS. 1A-1C  and the paraffin wax actuator exemplified in  FIGS. 2 ,  3 A- 3 B. An expanding wax reservoir can easily be designed to actuate a hammer retainer, thus releasing a lance hammer to rapidly relieve the high pressure in a cgc. Again, the paraffin can be tailored to melt, thus expand at a predictable temperature. 
     Intentionally dispensed fluid heat from cgc  205  or by heat-puncturing exits dispenser  200  through an exit port  265  and fluidly connects to any device or attachment desired in connection. 
     A puncturer  297  rotated about a post  299  allows one to manually puncture lance driver  235  toward cgc  205  and puncture cgc  205  with lance  226 . One skilled in the art could conceivable attach puncturer  297  to a host of manual or automated triggering devices to increase versatility of dispenser  200 . 
     An alternative embodiment that can be exemplified from  FIG. 2  utilizes a non-threaded neck cgc and utilizes a cgc cup to hold cgc into place. 
       FIG. 3A  illustrates a partial section view of an exemplary heat expandable pressure discharge dispenser  300  in a first position, in accordance with an embodiment of the present invention. Illustrated in  FIGS. 3A and 3B  are non-threaded cgc&#39;s  105  but threaded cgc&#39;s are equally intended to be within the scope of this embodiment. A monolithically formed dispenser body  310  houses reservoir  245  of paraffin wax or similar expandable substance. Abutted to wax in reservoir  245  is a slideable lance  335 , sealed in driver bore  236  by lance seal  228 . 
     Upon heating, wax in reservoir  245  expands thus displacing slideable lance  335  along driver bore  236  and punctures cgc  105  with piercing tip  226 . 
     To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope thereof which is limited only by a fair assessment of the following claims.