Abstract:
An inflator comprising a housing having an integrally formed mounting flange adapted to be heat-sealed directly to an inflatable article. A sleeve is injection molded in-situ inside the housing in which a pierce pin assembly is reciprocatably mounted within a central bore thereof. The sleeve within the housing allows the wall thickness of the housing to be significantly reduced and assures that the escaping gas from the cylinder always contacts the housing material. The sleeve includes a skirt extension with a socket defining the blind hole for receiving the end of the pivot pin of the firing lever to allow the injection-molding of a blind hole for the pivot pin without the need for subsequent drilling of the hole.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to an inflator for inflating articles such as personal floatation devices, rafts, buoys, and emergency signaling equipment. More particularly, this invention relates to inflators whose housings may be directly heat-sealed to the inflatable article while assuring that the inflatable article remains inflated even when the gas cartridge of the inflator is removed. 
         [0003]    2. Description of the Background Art 
         [0004]    Presently, there exist many types of inflators designed to inflate inflatable articles such as personal floatation devices (life vests, rings and horseshoes), life rafts, buoys and emergency signaling equipment. Inflators typically comprise a body for receiving the neck of a cartridge of compressed gas such as carbon dioxide. A reciprocating pierce pin is disposed within the body of the inflator for piercing frangible seal of the cartridge to permit compressed gas therein to flow into a manifold assembly of the inflator and then into the article to be inflated. Typically, a manually movable firing lever is operatively connected to the piercing pin such that the piercing pin pierces the frangible seal of the cartridge upon jerking of a ball lanyard. U.S. Pat. No. 3,809,288, the disclosure of which is hereby incorporated by reference herein, illustrates one particular embodiment of a manual inflator. 
         [0005]    Water-activated actuators have been incorporated into manual inflators so that in an emergency situation such as downed aviator, injured person or a man overboard, the inflator is automatically actuated to inflate the inflatable article to which it is connected. Representative automatic actuators for inflators are disclosed in U.S. Pat. Nos. 3,059,814, 3,091,782, 3,426,942, 3,579,964, 3,702,014, 3,757,371, 3,910,457, 3,997,079, 4,223,805, 4,267,944, 4,260,075, 4,382,231, 4,436,159, 4,513,248, 4,627,823, and 5,076,468, the disclosures of which are hereby incorporated by reference herein. 
         [0006]    As disclosed in the above-referenced patents, inflators, whether manually or water-activated, are typically connected to the inflatable article by means of the manifold assembly that consists of a metal manifold having a lower flange which is molded in situ with a rubber flange to establish a flow path between the flange and the metal manifold. A one-way valve, such as a schraeder valve, is installed in the manifold. During installation, a hole is formed in the inflatable article and the manifold is positioned therethrough. The flange of the manifold assembly is then heat-sealed to the wall of the inflatable article. Notably, the one-way valve in the manifold permits inflation of the inflatable article while precluding deflation once inflated. Representative patents relating to manifold assemblies are U.S. Pat. Nos. 5,080,402, 5,058,933, 5,058,932, 4,216,182, 3,809,288 and 3,754,731, the disclosures of which are hereby incorporated by reference herein. 
         [0007]    Correspondingly, typical inflators comprise a manifold hole which is configured and dimensioned to receive the manifold of the manifold assembly. A locking nut is threaded onto the end of the manifold to secure the inflator. An O-ring seal is provided to prevent leakage between the manifold and the inflator. 
         [0008]    During use, upon firing of the inflator, either manually or automatically, gas from the compressed gas cartridge flows into the manifold hole of the inflator and then into the manifold. The gas then flows past the one-way valve in the manifold and into the inflatable article. Since the one-way valve of the manifold assembly precludes deflation of the inflatable article, the gas cartridge may be removed from the inflator and the inflatable article will remain inflated. 
         [0009]    While manifold assemblies have been in extensive use in the industry for many years, they are relatively expensive to manufacture and require additional assembly operations. Accordingly, there existed a need in the inflator industry for an inflator which may be heat-sealed directly to the inflatable article thereby obviating the need for manifold assemblies and the like. 
         [0010]    U.S. Pat. No. 4,894,036, the disclosure of which is hereby. incorporated by reference herein, discloses an inflator which may be heat-sealed directly to an inflatable article thereby obviating the need for manifold assemblies and the like. The heat-sealable inflator as shown in such patent includes a mounting flange integrally formed about the housing of the inflator. The housing together with the integral mounting flange are composed of a plastic or similar material which may be heat-sealed to inflatable articles composed of conventional plastic or other materials. The housing includes a reciprocal pierce pin and a firing lever. A pair of compression springs are provided at opposing ends of the pierce pin to exert forces thereon in opposite directions. A pair of O-rings is also provided at opposing ends of the pierce pin. During firing upon jerking of the manual firing lever, the cammed end thereof exerts a force on the rearward (stronger) spring and causes the pierce pin to move forwardly and pierce the gas cartridge. The cammed end of the manual firing lever is configured such that upon further movement of the lever, the pierce pin may be blown-back fully rearwardly by means of the forward (weaker) compression spring combined with the pressure exerted by the gas from the gas cartridge. The bore of the housing in which the pierce pin is reciprocatably positioned is configured in such a manner that when the pierce pin is blown-back fully rearwardly, the gas may flow through a port into the inflatable article. However, once the gas has escaped from the gas cartridge into the inflatable article, the lost pressure allows the rearward (stronger) spring to return the pierce pin assembly to its rest position. The bore of the housing is configured so that when the pierce pin is in its rest position, the O-rings seal the port both forwardly and rearwardly in the bore thereby precluding the gas from the inflatable article from escaping. 
         [0011]    Unfortunately, the specific design of the heat-sealable inflator as shown in U.S. Pat. No. 4,894,036 is expensive to manufacture due to the necessity of dual springs and its other components. Moreover, it appears that the specific design could undesirably prevent inflation if the firing lever was only moved partially through its path of travel (see  FIG. 5  thereof). 
         [0012]    U.S. Pat. No. 5,564,478, the disclosure of which is hereby incorporated by reference herein discloses an improved heat sealable inflator having a design that is significantly easier to manufacture and less costly. The heat sealable inflator as disclosed in U.S. Pat. No. 5,564,478 comprises a housing with an integrally formed mounting flange that is injected molded. A pierce pin assembly is then assembled within a bore in the housing. A firing lever is then pivotally connected to the pierce pin assembly such that upon actuation of the firing lever, the pierce pin assembly is actuated to pierce the frangible seal of a gas cartridge threaded therein, thereby allowing inflation of the article to which the inflator is heat sealed. Unfortunately, however, the inflator of U.S. Pat. No. 5,564,478 requires thick wall sections for a metal thread insert that threadably receives the gas cartridge, thereby increasing cycle times and costs during injection molding. Moreover, the escaping gas contacts the heat sealable material along with the metal components of the pierce pin assembly, which could lead to leaks to the outside if adequate sealing adhesion is not attained between such components. Moreover, the pivot pin on which the firing lever pivots is installed through a hole that must be drilled through the housing. Since the main bore core pin, during injection, has water running through it, thereby precluding the possibility of positioning a pin for the pivot hole through the core pin. It is noted that the running water through the main bore core pin is required to maintain the type of tolerances required by the O-ring that seals the bore in the assembly. Accordingly, there presently exists a need for a more easily manufacturable and assemblable heat sealable inflator that allows thinner wall sections and obviates the need for manual drilling of the hole for the pivot pin of the firing lever. 
         [0013]    Therefore, it is an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the inflation art. 
         [0014]    Another object of this invention is to provide a heat-sealable inflator for inflatable articles having a housing with a mounting flange integral thereto, the housing and the flange being composed of a material that is capable of being easily sealed to the type of materials that are typically utilized in the construction of inflatable articles. 
         [0015]    Another object of this invention is to provide a heat-sealable inflator which utilizes a minimal number of components and is therefore economical to manufacture. 
         [0016]    Another object of this invention is to provide a heat-sealable inflator having a design which precludes deflation of the inflatable article once inflated even if the gas cartridge threaded into the housing is removed. 
         [0017]    Another object of this invention is to provide a heat-sealable inflator having a design which eliminates a condition of non-inflation even if the firing lever thereof does not move through its full path of travel. 
         [0018]    The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings. 
       SUMMARY OF THE INVENTION 
       [0019]    For the purpose of summarizing this invention, this invention comprises an inflator adapted to be heat-sealed directly to an inflatable article thereby obviating the need for inflation manifolds and the like. More particularly, the inflator of the invention comprises a housing having an integrally formed mounting flange. A pierce pin assembly is reciprocatably mounted within a central bore of the housing. Importantly, a sleeve is injection molded in-situ inside the housing in either an insert-molded or a two-shot molding process. 
         [0020]    The utilization of a sleeve within the housing allows the wall thickness of the housing to be significantly reduced, thereby significantly minimizing cycle times and costs during the injection molding process. Moreover, the molding of the sleeve in-situ inside the housing assures that the escaping gas from the cylinder always contacts the housing material. The likelihood of leaks which may otherwise occur because of the lack of adequate sealing adhesion during molding between the housing material and the sleeve is essentially eliminated due to the escaping gas always contacting the housing material. 
         [0021]    Another significant aspect of the heat sealable inflator of the invention is the incorporation of a blind hole for the pivot pin of the firing lever in the inflator body without the need for drilling the hole as is common in my prior patent, U.S. Pat. No. 5,564,478. More particularly, in this invention, the blind hole formed in the inflator housing is created by first injection molding the sleeve having a skirt extension formed with a socket defining the blind hole for receiving the end of the pivot pin. The blind hole of the socket is blocked-off during the molding of the housing around the cylinder in such a way that the plastic does not fill the hole. A more complete description of this molding process is described in our concurrently-filed patent application entitled “Two-Shot Injection Molding Manufacturing Apparatus and Method”, the disclosure of which is hereby incorporated by reference herein. 
         [0022]    The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which: 
           [0024]      FIG. 1  is a front view of the inflator of the invention; 
           [0025]      FIG. 2  is a rear view thereof; 
           [0026]      FIG. 3  is a right side view thereof; 
           [0027]      FIG. 4  is a left side view thereof; 
           [0028]      FIG. 5  is bottom view thereof; 
           [0029]      FIG. 6  is a top view thereof; 
           [0030]      FIG. 7  is a perspective view thereof; 
           [0031]      FIG. 8A  is a perspective view of the firing lever incorporated into the inflator of the invention; 
           [0032]      FIG. 8B  is a front view thereof; 
           [0033]      FIG. 8C  is a right side view thereof; 
           [0034]      FIG. 9A  is a front view of the housing of the inflator of the invention with all other components removed; 
           [0035]      FIG. 9B  is a right side view thereof; 
           [0036]      FIG. 9C  is a left side view thereof; 
           [0037]      FIG. 9D  is a top view thereof; 
           [0038]      FIG. 9E  is a bottom view thereof; 
           [0039]      FIG. 10A  is a front view of the operative components of the inflator of the invention with the housing omitted; 
           [0040]      FIG. 10B  is a right side view thereof; 
           [0041]      FIG. 10C  is a left side view thereof; 
           [0042]      FIG. 10D  is a top view thereof; 
           [0043]      FIG. 10E  is a perspective view thereof; 
           [0044]      FIG. 11A  is a cross-sectional view of  FIG. 10B  along lines  11 A- 11 A with the firing lever removed for clarity; 
           [0045]      FIG. 11B  is a perspective view of  FIG. 11A ; 
           [0046]      FIG. 11C  is a partial cross-sectional of the inflator of the invention employing an alternative embodiment of a check valve to prevent an inflated inflatable from deflating in the event the gas cartridge is removed; 
           [0047]      FIG. 11D  is a partial cross-sectional of the inflator of the invention employing another alternative embodiment of a check valve to prevent an inflated inflatable from deflating in the event the gas cartridge is removed; 
           [0048]      FIG. 12A  is a cross-sectional view of  FIG. 10A  along lines  12 A- 12 A; and 
           [0049]      FIG. 12B  is a perspective view thereof. 
       
    
    
       [0050]    Similar reference characters refer to similar parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0051]    Referring to  FIGS. 1-7 , the heat sealable inflator  10  of the invention comprises a generally rectangular housing  12  having an integral peripheral flange  14 . The material constituting the housing  12  with its flange  14  is composed of a heat sealable material such as polyurethane that may be heat sealed to conventional inflatable articles such as personal floatation devices, life rafts, and the like (not shown). Characteristically, the material constituting the housing  12  and its integral flange  14  is of a generally softer material having a hardness in the range of 40 to 90 on the durometer scale Shore D and a tensile strength of about 5800 psi. 
         [0052]    As best shown in  FIG. 2 , formed in the rear surface  16  of the inflator housing  12  is an exhaust port  18  which provides fluid communication from the inflator  10  into the inflatable article (not shown). 
         [0053]    As best shown in  FIG. 7 , the inflator  10  is adapted to receive the threaded neck of a gas cylinder (shown in phantom as numeral  20 ) such that upon release of the gas therefrom, the gas may flow through the inflator  10  and then out the exhaust port  18  (see  FIG. 2 ) into the inflatable article (not shown). 
         [0054]    As shown in  FIG. 7 , the inflator  10  comprises a firing lever  22  to which is tethered a jerk handle  24  by means of a braided lanyard  26 . A removable safety clip  28  is provided for retaining the firing lever  22  into its normal unfired position substantially flush with the left side  30  of the inflator (see  FIGS. 5 and 6 ) such that the firing lever  22  does not protrude therefrom and otherwise be inadvertently caught or snagged. 
         [0055]    The firing lever  22  is shown in  FIGS. 8A ,  8 B and  8 C and generally comprises an L-shaped configuration having an upstanding arm  32  to which the lanyard  26  is inserted into and tightly and permanently secured such as by staking. The lower leg portion  34  of the firing lever  22  comprises a pivot hole  36  through which a pivot pin  38  is inserted and a cammed surface  40  which is operatively designed to cam against the actuator pin  42  of the pierce pin assembly  44  described hereinafter in more detail. To reduce friction, the pivot hole may be a plurality of upstanding protrusions  36 A encircling the pivot hole  36 . 
         [0056]      FIGS. 9A-9E  illustrate the housing  12  of the invention with all of the other components removed. Correspondingly,  FIGS. 10A-10E  illustrate the other components that are assembled within the housing  12  of  FIG. 9 . These other components shown in  FIG. 10  include the firing lever  22  and the safety clip  28  as previously described above and a safety flag  48 , preferably colored red, that is snap-fitted between ridges  50  formed in the housing  12 . The safety flag  48  is hidden behind the firing lever  22  when the firing lever  22  is in its unactuated/unfired condition. Conversely, the flag  48  is exposed when the firing lever  22  is actuated, thereby indicating a fired condition. 
         [0057]    As best shown in  FIGS. 11A and 11B  and  12 A and  12 B, a generally cylindrical sleeve  52  is molded in-situ with the housing  12 . The cylindrical sleeve  52  comprises at its upper portion  42  a threaded bore  56  for receiving the threaded neck of the gas cylinder  20 . 
         [0058]    As best shown in  FIGS. 11A and 11B  and  12 A and  12 B, the pierce pin assembly  44  is reciprocatably positioned within a longitudinal bore  60  of the housing  12 . The pierce pin assembly  44  comprises an actuator pin  42  with a firing pin  54  staked therein for piercing the frangible seal of the gas cartridge  20  when actuated. The actuator pin  42  comprises an O-ring groove  62  at its lower end for receiving a conventional O-ring  64 . The O-ring  64  prevents air flowing from the gas cartridge  20  from escaping from the longitudinal bore  60  such that it is directed to exit the housing  12  via exhaust port  18  to flow into and inflate the inflatable. 
         [0059]    It is noted that once the gas cartridge  20  is removed, an air may simply escape from inflated inflatable path in the reverse direction. In order to prevent deflation of the inflatable once the gas cartridge  20  is removed, a check valve is employed. The preferred embodiment of the check valve best illustrated in  FIGS. 11A and 11B  comprises a seat assembly  66  that is reciprocally and sealingly positioned over the actuator pin  42 . The seat assembly  66  comprises an annular seal  68  positioned within a retainer clip  70  for support. The annular seal  68  functions to seal against the opening  72  in the bore  60  leading into the threaded bore  56  and against the outer cylindrical surface of the actuator pin  42 . A spring  74  is positioned between the seat assembly  66  and the O-ring groove  62  to urge the seal  68  into sealing engagement with the opening  72  and to allow the seat assembly  66  to blow back by the force of the escaping gas from the cartridge  20  upon firing. The spring  74  also functions to return the seat assembly  66  to its sealing engagement with the opening  72  after the gas has escaped, thereby preventing leakage of the inflated inflatable in the event the gas cartridge  20  is removed. 
         [0060]    Another embodiment of the check valve is illustrated in  FIG. 11C  and comprises a flapper valve  68 A that secured over the exhaust port  18  by a fastener  69 . The flapper valve is composed of a sealing material that forms a seal with the exhaust port  18  when the inflatable is inflated, thereby allowing the gas cartridge  20  to be removed without deflation of the inflatable. 
         [0061]    Still another embodiment of the check valve is illustrated in  FIG. 11D  and comprises an annular seal  68 B centered within a retainer ring  70 A for support. The annular seal  68 B functions to seal against the exhaust port  18 . A spring  74 B is positioned between the retainer ring  70 A and an annular mounting ring  70 A secured to the housing  12  to urge annular seal  68 B into sealing engagement with the exhaust port  18  and to allow annular seal  68 B to blow back by the force of the escaping gas from the cartridge  20  upon firing. The spring  74 B also functions to return the annular seal  68 B to its sealing engagement with the exhaust port  18  after the gas has escaped, thereby preventing leakage of the inflated inflatable in the event the gas cartridge  20  is removed. 
         [0062]    It is noted that as shown in  FIGS. 11C and 11D , the pierce pin  54  may comprise a central passageway that allows the flow of gas through the pierce pin  54  and the actuator pin  42  to exit therefrom proximate to the exhaust port  18 . However, when using the pierce pin assembly  44  of the preferred embodiment, the pierce pin  54  may simply be fluted as shown in the other figures whereupon the escaping gas simply flows through the flute on the pierce pin  54  to blow back the seat assembly  66 , then around the actuator pin  42  to exit the exhaust port  18 . 
         [0063]    An important feature of the present invention is the use of the cylindrical sleeve  52  of  FIG. 10  in combination with the housing of  FIG. 9 . Specifically, as noted above, the material constituting the housing  12  should be of a softer material that is heat sealable with conventional articles to be inflated. In contrast, the material constituting the cylindrical sleeve  52  may be of a significantly harder, high-strength, material such as glass-filled nylon and having a tensile strength of about 30,000 psi. According to the invention, the cylindrical sleeve  52  is injection molded in a first step and then the housing  12  is injection molded about the sleeve  52  in a second injection molding step. These two steps may occur with the cylindrical sleeve  52  being insert-molded or with the cylindrical sleeve  52  being formed in-situ in a two-step molding process as more particularly set forth in our concurrently-filed patent application directed to the same and incorporated by reference herein. 
         [0064]    Since the material constituting the cylindrical sleeve  52  is composed of a much stronger material than that of the housing  12 , it should be appreciated that it can better withstand the significant pressures that occur immediately upon actuation when gas is rapidly flowing from the gas cartridge  20  through the housing  12  into the inflatable article. Indeed, the use of the cylindrical sleeve  52  in the structure provides the needed strength to withstand the force of the rapidly-flowing gas from the cartridge. Yet, the gas contacts only the housing  12  and no portion of the sleeve  52 . The likelihood of separation between the materials is therefore essentially eliminated since the gas flows directly into the article being inflated without contacting the bond formed between the materials constituting the sleeve  52  and the housing  12 . 
         [0065]    Another significant advantage achieved by utilizing the cylindrical sleeve  52  as described above is the ability to incorporate a depending skirt portion  76  therefrom which forms a socket  78  with a blind hole for receiving the pivot pin  38 . Specifically, the socket  78  depending from the skirt  76  is embedded within the housing  12  during the two-step injection process. Consequently, during assembly, the pivot pin  38  may be easily inserted therein without having to pre-drill a hole as in the case of my prior patent, U.S. Pat. No. 5,564,478. The elimination of any need for pre-drilling significantly reduces manufacturing and assembly costs. A more detailed description of the manufacturing apparatus and method for forming the blind hole is set forth in our concurrently-filed application noted above that is hereby incorporated by reference herein. 
         [0066]    The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention. 
         [0067]    Now that the invention has been described,