Abstract:
A gas cartridge introduced into the housing of the invention is punctured by a pin moved by an arm designed to show through a series of windows whether the cartridge is full or empty. A pulling on a tab rotates the arm to action, in puncturing the cartridge and a spring then locks the visual displays in position. The pin is provided with a cone-shaped head which prevents any re-arming of the arm from changing the display to show that the cartridge is full, when in fact the cartridge has been spent. The amount of pull needed to activate the arm can be selectively controlled.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     NONE 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Research and development of this invention and Application have not been federally sponsored, and no rights are given under any Federal program. 
     REFERENCE TO A MICROFICHE APPENDIX 
     NOT APPLICABLE 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to the marine inflatable device industry and, more particularly, to apparatus for inflating life preservers, vests, rafts, or similar such devices in accordance with Coast Guard and Airline rules and/or regulations. 
     2. Description of the Related Art 
     Small cartridges which hold large quantities of carbon dioxide or other gas under compression for inflating these types of devices are known. Typical are those described in the Mackal U.S. Pat. Nos. 3,809,288; 4,223,805; 4,267,944; 4,498,605; 5,058,635; and 5,333,656. As this last patent pointed out, one problem in the industry followed from the fact that a person could not quickly determine whether the cartridge attached to the inflator was spent. Since a discharged cartridge was virtually identical in outward appearance to a fully charged one, the possibility existed that the cartridge in place was empty, and not filled. As the patent noted, the only way to resolve the question was to unscrew the cartridge, and visually inspect its membrane to see whether it had been already punctured. 
     U.S. Pat. No. 5,333,656 addressed the problem by painting a red sign on an inflator arm, to appear in a window when the arm was in the discharge position of the inflator, to indicate that the cartridge was empty. Although the theory was that the red sign would disappear only after a full cartridge was replaced back into position, testing revealed that the red sign on the inflator arm was moved out of the viewing area no matter the condition of the replacement cartridge being reinserted. Investigation revealed that this followed from the irregular type hole the patent&#39;s chisel-shaped pin produced when puncturing the cartridge to release its compressed gas when filling the inflatable device. The intent of the invention—to show that an empty cartridge was in place—was thus not reliably achieved. 
     Further testing showed that this problem persisted even with the modified puncture pin described in Mackal&#39;s earlier U.S. Pat. No. 5,058,635. There, it was found that its chisel-shaped head often caused the puncture hole rim to snag on the pin, and because the arrangement also included an internal spring. that was biased in a direction to exert a backward pull on the puncture pin. Such biasing was noted to sometimes snag (and lodge) on its way into the charged cartridge during its detonation—which interfered with the desired venting and inflation. 
     These puncture pin problems were overcome, however, with the safety inflator described in my own U.S. Pat. No. 5,643,030, in which the pin was provided with a cone-shaped head. With it, a perfectly round hole was created upon puncture in the cap of the gas cartridge. This puncture pin possessed a barely perceptible flat head, enabling it to bear against the cap without prematurely puncturing it, as if the head were pointed instead. With the cone-shaped configuration, the accidental insertion of a spent cartridge was automatically prevented from changing the display to improperly indicate the cartridge to be full when, in fact, it were empty. 
     SUMMARY OF THE INVENTION 
     As will become clear from the following description, the inflator of the present invention retains this cone-shaped, cross-section puncture pin, although somewhat modified, to prevent any cartridge replacement from wrongly changing a display of readiness. As will also become clear, the inflator of the invention goes one step further, in offering a construction which makes it easier to observe the cartridge condition than with my U.S. Pat. No. 5,643,030 design, and one which is more compact for use. In one version, a snap-action lever arm is employed to allow controlled detonation at even low pull tensions. In a second version, an internal signalling flag is removed to significantly reduce the size and weight of the inflator. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features of the invention will be more clearly understood from a consideration of the following description, taken in connection with the accompanying drawings, in which: 
     FIG. 1 is a disassembled view of a compressed gas safety inflator for life vests, life rafts and the like according to the invention; 
     FIGS. 2A and 2B are perspective views of the compressed gas safety inflator in assembled form for the “armed” and “discharged” conditions of the inflator, respectively; 
     FIGS. 3 and 4 are internal views of the compressed gas safety inflator for the “armed” and “discharged” conditions, respectively; 
     FIGS. 5A and 5B are top and bottom views, respectively, of the inflator arm of the invention and of the inflator body, helpful in an understanding of the invention; 
     FIG. 6 is a view of the partially assembled, partially disassembled compressed gas safety inflator of the invention, employing the snap-action feature for detonation at even low pull tensions; 
     FIG. 7 is an internal view of an embodiment of the compressed gas safety inflator in which the “cartridge display readiness flag” has been removed; and 
     FIG. 8 shows a puncture pin constructed in accordance with the invention to detonate a gas cartridge of the types illustrated in FIGS. 1-4 and  6 - 7 , modified somewhat from the puncture pin of my U.S. Pat. No. 5,643,030 patent. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS.  1  and  3 - 4  illustrate several improvements and modifications to the safety inflator indicator flag described in my afore-noted patent. There, the indicator flag was colored “green” and “red”—whereas, here, the flag consists of two plastic parts  10  and  12 , the one  10  being permanent green plastic and the other  12  being permanent red plastic to insure that the green and red colors remain distinctly separated on the flag. With the color “green” being shown in the drawings by “vertical lines”, and with the color “red” being shown by “horizontal lines”, this further insures that the colors will not fade or wear over time, and that the ratios of the coloration for each flag will be exactly the same. By otherwise painting or hot-stamping the colors onto the flag, a risk results that the colors might run together or be otherwise incorrectly applied in a manner to throw-off the correct red/green color ratio. 
     Both plastic parts are hollow, with the red plastic part  12  having a pin  14  to seat within a hole  16  on the green plastic part  10  for a secure, permanent fit to anchor the parts  10 ,  12  together. One end  17  of a spring  18  is inserted into the hollow opening of the green plastic part  10  to attach to a hook  19 , while a second opposite end  21  loops around a pin  20  in the inflator body  22  (FIGS. 3,  4 ). This attachment of the spring  18  to the part  10  and to the pin  20  expedites the assembly of the inflator. Such pin  20  may also be of plastic, and automatically molded into the inflator body  22  to save the cost of an extra steel pin in securing the spring  18  in place. The injection mold cam employed to produce the plastic pin  20  leaves a hole in the side of the inflator body  22 , which is covered with a small, circular plug  23 . (As will be appreciated, the “hollowing-out” of the green/red plastic parts by “coring” is a common occurrence in an injection molding process; this allows the entire flag to be manufactured faster as it reduces the cycle time for molten plastic material to be injected into the mold, and offers the further feature of the finished flag being significantly lighter for use in those instances where weight considerations are important—for example, when employing the compressed gas safety inflator of the invention for use in an airline vest where “weight” is an important factor in determining jetliner fuel consumption costs.) 
     Whereas the cover for the safety inflator of my U.S. Pat. No. 5,643,030 was secured by metal screws, the cover  24  employed here is devoid of any screws, but is allowed to slide via raised tongue ridges on opposite sides  25  into a pair of grooves  26 . Once in place, the cover  24  then snugly fits with the body  22  so as not to be dislodged upon falling. A signalling window having a bevelled side is cut into the top of the cover  24  at  27 , and a pair of similar signalling windows  29  are cut on opposite sides of the inflator body  22 , also with bevelled sides. The three windows offer easy, wide viewing of the flag color in alignment therewith. 
     A pair of signalling windows  30  are additionally included, one on each side of the inflator body  22  adjacent to a body slot  32  for the inflator arm  34 . Two small pieces of green plastic snap onto each side of the inflator arm  34  at  36 , to be seen only through the window  30  when the inflator arm  34  is closed and a fully charged compressed gas cartridge is in place. 
     As previously noted, FIG. 5A is a top view of the inflator arm  34  while FIG. 5B is a bottom view of the inflator body  22 . A pair of small, red plastic tabs snap into place within two slots  39  of the arm  34  to signal through the windows  30  when the inflator arm  34  is jerked downward and the compressed gas cartridge is discharged. When the inflator arm  34  is in the closed position, on the other hand, the two red tabs enter the two slots  39  in the inflator arm and become concealed. Such red tabs are shown at  41  in FIG. 5B, adjacent the windows  30 . 
     A first pin  45  passes through an aperture  46  in the body  22  to align with an aperture  48  in the inflator arm  34  to hold it in position and serve as a pivot point. A pull-tab  50  couples to a lanyard  52  for rotating the inflator arm  34  in a counterclockwise direction when jerking downwardly on the tab  50 . In so doing, the inflator arm  34  rotates about the pin  45  in apertures  46  and  48 . 
     FIGS. 2A and 2B show the external views of the compressed gas safety inflator for the “armed” and “discharged” conditions of the inflator, before and after the tab  50  is jerked downwardly. The gas cartridge is shown at  60 , with the manifold hole for filling the inflatable life preserver, vest, raft, etc. being shown at  62 . 
     FIG. 3 is an internal view of the safety inflator of the invention in its armed position with a fully charged compressed gas cartridge  60  in place. With the green and red signalling parts, or flags  10 ,  12  pinned together as described, and inserted over the flag arm or lever  65 , the signalling feature of the safety inflator is activated when the compressed gas cartridge is inserted. Such action forces the detonator or puncture pin  67  rearwardly against the arm  65  (i.e. to the right), which pivots the arm  65  against the action of the spring  18  about a second pin  47  passing through a second aperture  49  in the body  22  in alignment with an aperture  53  in the arm  65 . This action-continues to force the arm  65  in a clockwise direction until it contacts a cam surface  71  of the inflator arm  34  until it reaches its closed position which exactly corresponds to the cartridge being fully screwed into its threaded well. In such position, the green plastic part  10  shows through the window  27  of the cover  24  and through the windows  29  on each side of the body (i.e., the “vertical lines” in FIG.  3 ). 
     With the tab  50  jerked downwardly to actuate the inflator, the view of FIG. 4 results, in which the cam surface  71  of the inflator arm  34  bears against the lever arm  65  to rotate it in a counterclockwise direction about the pin  47  in aperture  53 , compressing the spring  18  until the puncture pin  67  pierces the compressed cartridge cap, detonating the cartridge  60 , and venting its contained gas into the life vest or other inflatable device via the manifold  62 . In such position, the red plastic part  12  then becomes visible through the signalling windows  27  and  29  (i.e., the “horizontal lines” in FIG.  4 ). As will be appreciated by those skilled in the art, the green notation through the windows  30  is likewise switched to the red notation when the tab  50  and the inflator arm  34  are thus yanked downwardly. 
     (In this respect, FIG. 3 shows the body or housing  22  that includes a chamber  100 , in part defined by internal front and rear housing walls  101 ,  102  respectively. Within the chamber  100  is the puncture pin  67 , with its barrel end  103  extending through the rear wall  102  and with its cone-shaped cross-section head end  104  extending towards the front wall  101 . As will be seen, screwing in the cartridge  60  forces its cap to bear against the head end  104  of the puncture pin  67 .) 
     The embodiment of the invention shown in FIG. 6, on the other hand, is quite useful in detonating the compressed gas cartridge with minimal pressure pull when jerking downwardly on the tab actuator  50 . This is particularly attractive in instances within the province of the United States Coast Guard—whose regulations presently require that a compressed carbon dioxide cartridge, for example, discharge at an inflator arm pull pressure of no less than 5 pounds, and no more than 15 pounds. Because of variations in the internal assembly manufacture of inflators presently on the market (and because of variations in the manufacture and operation of their enclosed compressed gas cartridges), many violations have been noted to occur where detonation has taken upwards of 25-30 pounds to discharge. With the embodiment of the invention shown in FIG. 6, these problems are overcome, and through the use of a small, elevated ridge molded into the inflator arm  34  which allows the arm to firmly snap over a small plastic lip located in the body of the safety inflator, between the middle of the lanyard holes located on each underside of the body. 
     Such ridge is shown in FIG. 6 as  80  with the plastic lip in the inflator body  22  being shown at  81 . By adjusting the thickness of the elevated ridge  80  (measured from left-to-right in the drawing) the inflator arm  34  will automatically pull free from the inflator body  22  at any predetermined tension selected. By making the ridge  80  slightly thicker, the inflator arm  34  will firmly snap into the inflator body  22 , and consistently release at a pull force of approximately 15 pounds. By making the elevated ridge  80  slightly thinner, the inflator arm  34  would release from the body  22  at a lesser pull force, for example, at about 5 pounds. 
     As will be understood, when this arm snap-fit feature of FIG. 6 is included, the two signalling windows  30  of the inflator body  22  must be removed since the signalling feature of the inflator relies first, on closing the inflator arm  34  by snapping it shut, and second, by screwing in the fully charged compressed gas cartridge  60 . This is to be contrasted with the signalling actions described with respect to the constructions of FIGS.  3  and  4 —which rely on screwing in the fully charged compressed gas cartridge  60  first—which, in turn, moves the detonating pin  67 , the flag and the inflating arm cam until the inflator arm  34  closes. 
     The embodiment of the invention shown in FIG. 7, on the other hand, is one which is desirable in those instances where weight is a critical consideration, as with airline life vests, in attempting to keep down fuel costs. In particular, this embodiment is one in which the green and red plastic parts  10 ,  12  are removed, as well as the signalling windows  27  and  29 . In this mini-version of the inflator, only the signalling windows  30  are retained, one on each side of the inflator arm  34  as shown in FIG.  1 . 
     In the operation of the safety inflator of FIG. 7, when a fully charged compressed gas cartridge with an intact cap is screwed into the inflator, the cap forces back the puncture pin  67 , which forces the cam  71  on the arm  34  to rotate clockwise in a manner to close into the inflator body itself. Once the cartridge is snugly screwed into place, the green plastic pieces at  36  on each side of the arm  34  then show through the two windows  30 , signalling that the inflator is armed. If, on the other hand, a discharged cartridge with a hole in the cartridge cap is screwed into the inflator, the detonator pin  67  will penetrate into the hole—but neither the detonator pin nor the inflator arm cam will move. As a consequence, the inflator arm  34  will not close, and its red signals will remain in the two lower windows  30 , thereby signalling that a fully charged gas cartridge must still be reinserted into the inflator. 
     FIG. 8 shows a modified detonating puncture pin inflator to that shown in my U.S. Pat. No. 5,643,030. While still having a barely perceptible flat tip, this detonator pin  67  has the sides of the pin taper at a much sharper angle. This allows the cone shaped pin head to more easily penetrate the charged cartridge cap. This is so even for the situation where the cone shaped pin head includes a slightly rounded tip with a collar behind it. 
     One further improvement in the pin  67  follows from the possible tendency for the puncture pin of my earlier patent to slide too far forward when the inflator arm is pulled downwardly—which might sometimes cause the pin head to enter the cartridge and snag against the rim of the cartridge cap hole. By widening and extending the length of the pin into a round barrel directly in front of the “O” ring wall, the top of the barrel forms an upper step which comes into direct contact with the retaining wall that forms the bottom of the threaded hole in which the cartridge is screwed. This stops the pin from advancing too far into the cartridge once the inflator is activated. Since the lower step of the barrel does not quite reach the retaining wall, when the compressed gas passes down through the vent notch, the open space directly in front of the lower barrel step allows the gas to vent over this lower step directly into the life vest or other inflatable device. As with my earlier patent, the compressed gas may typically be carbon dioxide. 
     In FIG. 8, the “O” ring is shown at  90 , the lower step is shown at  92 , the upper step is shown at  93 , the collar behind the cone shaped head  94  is shown at  96 , the vent notch is shown at  98 , and the flat or slightly rounded pin tip is shown at  105 . 
     While there have been described what are considered to be preferred embodiments of the present invention, it will be readily appreciated by those skilled in the art that modifications can be made without departing from the scope of the teachings herein. For at least such reason, therefore, resort should be had to the claims appended hereto for a true understanding of the scope of the invention.