Abstract:
A pill for insertion into a bobbin of a bobbin assembly of an automatic inflator, the pill including a distal surface and a proximal surface, at least one of the surfaces including an undulating configuration.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to automatic inflators for inflatable articles such as life rafts, life vests, and the like. More particularly, this invention relates to inflators that are actuated automatically upon immersion in water. 
     2. Description of the Background Art 
     Presently, there exists 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. Manual inflators typically comprise a body for receiving the neck of a cartridge of compressed gas such as carbon dioxide. A reciprocating piercing pin is disposed within the body of the inflator for piercing the 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 gas 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. 
     While manual inflators work suitably well, it was quickly learned that in an emergency situation, the person needing the assistance of the inflatable device, such as a downed aviator, injured person, or a man overboard, would fail or be unable to manually activate the inflator. Accordingly, it was realized that a means should be provided for automatically activating the inflator in such an emergency situation. 
     In response to this realized inadequacy of the prior art manual inflators, water-activated automatic inflators were developed which, when exposed to a fluid such as water, automatically activated the piercing pin of the inflator when immersed in water thereby causing inflation of the inflatable device. Typical water-activated automatic inflators comprise a water activated trigger assembly including a water destructible or dissolvable element, often referred to as a “bobbin”, which retains a spring-loaded actuator pin in a cocked position in alignment with a piercing pin. Upon exposure to water, the “pill” contained within the bobbin immediately starts dissolving and then destructs altogether once it loses sufficient rigidity and therefore the bobbin loses its ability to hold-back the spring-loaded actuator pin in its cocked position. The spring-loaded actuator pin is thus released to forcibly move from its cocked position to an actuated position to strike the piercing pin, either directly or indirectly by means of an intermediate transfer pin. Upon striking the piercing pin, the pin fractures the seal of the cartridge thereby allowing the gas contained therein to flow into the inflatable device to inflate the same. 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, 5,076,468, 5,601,124, 5,685,455, 5,562,233, 5,370,567, 5,333,756, 4,488,546 and 5,694,986, the disclosures of which are hereby incorporated by reference herein. 
     While the above referenced automatic inflators operate quite well in inflating inflatable devices in the event of an emergency situation, one major disadvantage to these automatic inflators is the tendency of their bobbins to prematurely destruct in non-emergency situations by exposure of the pill contained therein to excessive humidity. Bobbin pills of various designs and chemical compositions have been used to minimize their susceptibility to humidity. Indeed, the problem of premature and unintentional activation of automatic inflators is so acute that it is not uncommon for the water-destructible bobbins of the automatic inflators to be replaced on a regular basis as part of a periodic maintenance program, particularly when the inflators are employed in humid weather conditions or around water. In this regard, it is noted that each of the prior art water-activated automatic inflators disclosed in the above referenced patents teach a structure which may easily be disassembled to facilitate the replacement of the water destructible bobbin so that the inflator may be periodically maintained by replacing the bobbin. In order to minimize such periodic maintenance, there therefore exists a need for an improved bobbin pill that is less susceptible to humid weather conditions and yet retains its ability to immediately dissolve upon being immersed in water. 
     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. 
     Another object of this invention is to provide an improved bobbin pill design for an automatic inflator that is less susceptible to humid weather conditions that may prematurely activate the automatic inflator in non-emergency situations. 
     Another object of this invention is to provide an improved bobbin pill design for an automatic inflator that provides sufficient strength to retain the actuator pin in its cocked position and thereby minimize premature activation of the automatic inflator in non-emergency situations. 
     Another object of this invention is to provide an improved bobbin pill design for a bobbin of an automatic inflator that comprises at least one surface having an undulating configuration having an increased strength to hold-back the spring-loaded actuator pin and an increased surface area to facilitate dissolving once exposed to water to thereby be less susceptible to humid weather conditions that may otherwise result in the premature activation of the automatic inflator in non-emergency situations. 
     Another object of this invention is to provide an improved bobbin pill design for an automatic inflator that comprises a surface having an undulating configuration applied to opposing surfaces of the bobbin pill, with the opposing undulations being aligned with respect to each other to maximize the increased strength to hold-back the spring-loaded actuator pin while still being capable of easily dissolving once exposed to water to thereby be less susceptible to humid weather conditions that may otherwise result in the premature activation of the automatic inflator in non-emergency situations. 
     Another object of this invention is to provide an improved bobbin pill design of various shapes such as annular-shaped (flat and dome-configured) with a center hole, disk-shaped without a center hole, cylindrical-shaped, etc. for use with the respective style of automatic inflator, each such pill shape including an undulating surface configuration that increases the strength to hold-back the spring-loaded actuator pin while still being capable of easily dissolving once exposed to water to thereby be less susceptible to humid weather conditions that may otherwise result in the premature activation of the automatic inflator in non-emergency situations. 
     Another object of this invention is to provide an improved bobbin pill design for an automatic inflator that comprises non-uniform thickness having an increased strength to hold-back the spring-loaded actuator pin yet still being easily dissolvable once exposed to water to thereby be less susceptible to humid weather conditions that may otherwise result in the premature activation of the automatic inflator in non-emergency situations. 
     Another object of this invention is to provide an improved bobbin pill design of various shapes such as annular-shaped (flat and dome-configured) with a center hole, disk-shaped without a center hole, cylindrical-shaped, etc. for use with the respective style of automatic inflator, each such shape including a non-uniform thickness that increases the strength to hold-back the spring-loaded actuator pin while still being capable of easily dissolving once exposed to water. 
     These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or by modifying the invention within the scope of the disclosure. Accordingly, other objects and a more comprehensive understanding of the invention may be obtained by referring to the summary 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 
     The invention is defined by the appended claims with the specific embodiment shown in the attached drawings. For the purposes of summarizing the invention, the invention comprises an improved pill of a bobbin for a water-activated automatic inflator that is less susceptible to humid weather conditions that may otherwise prematurely activate the automatic inflator in non-emergency situations. In one embodiment, the pill of the bobbin of the invention comprises at least one surface having an undulating configuration. The undulating surface configuration increases the strength of the bobbin pill to hold-back the spring-loaded actuator pin and increases the surface area to enhance dissolving once exposed to water. In another embodiment, the pill of the bobbin of the invention comprises a non-uniform thickness that is configured to increase the strength of the bobbin pill to hold-back the spring-loaded actuator pin while still being able to be easily dissolved once exposed to water. The undulating configuration and the non-uniform thickness features of the invention may be both utilized to achieve a bobbin pill having both an undulating surface configuration and a non-uniform thickness. 
     The pill of the bobbin may comprise various shapes, with each such shape including the undulating surface configuration and/or non-uniform configuration in accordance with the invention, such as annular-shaped with a center hole, disk-shaped without a center hole, cylindrical-shaped, etc. for use with the respective style of automatic inflator. In this manner, it should be appreciated that in accordance with the invention, the undulating surface configuration and/or the non-uniform thickness may be incorporated into virtually all bobbin pills of different shapes and therefore the invention is adaptable to virtually all existing makes and models of water-activated inflators. 
     The foregoing has outlined rather broadly, the more pertinent and prominent features of the present invention. The detailed description of the invention that follows is offered so that the present contribution to the art may be more fully appreciated. Additional features of the invention will be described hereinafter. These form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the disclosed specific embodiment may be readily utilized as a basis for modifying or designing other methods and 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 structures do not depart from the spirit and scope of the invention as set forth in the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more succinct understanding of the nature and objects of the invention, reference should be directed to the following description taken in conjunction with the accompanying drawings in which: 
     FIG. 1 is a longitudinal cross-sectional view of a particular style of an automatic inflator assembly showing the various internal parts and their relative position to one another; 
     FIG. 1A is a distal plan view of automatic inflator&#39;s bobbin assembly having the improved pill of the invention installed therein; 
     FIG. 1B is a proximal plan view of FIG. 1A; 
     FIG. 1C is a diametric cross-sectional view of FIG. 1A; 
     FIG. 2A is a plan view of the first embodiment of the pill design of the invention; 
     FIG. 2B is an edge view of FIG. 2A showing the first embodiment of the pill design of the invention with the undulating proximal and distal surfaces thereof, with such undulations of the distal and proximal surfaces of the pill being out-of-phase with each other; 
     FIG. 2C is a cross-sectional view of FIG. 2B along lines  2 C— 2 C; 
     FIG. 3A is a plan view of the second embodiment of the pill design of the invention; 
     FIG. 3B is an edge view of FIG. 3A showing the cross-sectional configuration of the second embodiment of the pill design of the invention with the undulating proximal and distal surfaces thereof, with such undulations of the distal and proximal surfaces of the pill being in-phase with each other; 
     FIG. 3C is a cross-sectional view of FIG. 3B along lines  3 C— 3 C; 
     FIG. 4A is a plan view of the third embodiment of the pill design of the invention in which the undulations are in a checkerboard or quilted configuration. 
     FIG. 4B is an edge view of FIG. 4A showing the third embodiment of the pill design of the invention with such checkerboard undulations of the distal and proximal surfaces of the pill being out-of-phase with each other; 
     FIG. 4C is a cross-sectional view of FIG. 4B along lines  4 C— 4 C; 
     FIG. 5A is a plan view of the fourth embodiment of the pill design of the invention in which the undulations are positioned concentrically; 
     FIG. 5B is an edge view of FIG. 5A showing the fourth second embodiment of the pill design of the invention; 
     FIG. 5C is a cross-sectional view of FIG. 5B along lines  5 C— 5 C showing the concentric undulations of the distal and proximal surfaces of the pill being out-of-phase with each other; 
     FIG. 6A is a plan view of the fifth embodiment of the pill design of the invention having a non-uniform configuration with a thicker inside edge and a thinner outside edge; 
     FIG. 6B is an edge view of FIG. 6A showing the fifth embodiment of the pill design of the invention; 
     FIG. 6C is a cross-sectional view of FIG. 6B along lines  6 C— 6 C showing the frusto-conical cross-sectional configuration of the non-uniform configuration; 
     FIG. 7A is a plan view of the sixth embodiment of the pill design of the invention having a non-uniform configuration with thicker inside and outside edges and a thinner middle portion; 
     FIG. 7B is an edge view of FIG. 7A showing the sixth embodiment of the pill design of the invention; and 
     FIG. 7C is a cross-sectional view of FIG. 7B along lines  7 C— 7 C showing the double frusto-conical cross-sectional configuration of the non-uniform configuration. 
     Similar reference numerals refer to similar parts throughout the several figures. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 illustrates an exemplary automatic inflator  10  as comprising an inflator body  12 , an actuator body assembly  14 , and a cylindrical cap assembly  16 . The inflator body  12  has a longitudinal central bore, generally indicated by numeral  18 , having a proximal end and a distal end and which is sized to receive a piercing pin assembly  20  reciprocatably positioned therein so that a gas-containing cartridge  22  is pierced when the piercing pin assembly  20  is forcibly moved proximally towards the cartridge  22 . The piercing pin assembly  20  comprises a piercing pin  24  having a distal end portion  26 , a sealing gasket  28 , and a small compression spring  30 . A conventional metal insert  32 , having interior threads  34  and gasket  36 , is molded in situ within the upper portion of the inflator body  12 . The gas-containing cartridge  22  is threaded into the metal insert  32 . The gasket  36  assures that the gas-containing cartridge  22  is sealed within the metal insert  32 . 
     The automatic inflator includes a manual actuator. As seen in FIG. 1, the manual actuator means includes a lever  38 , of generally an L-shape, pivotally mounted to the distal portion of the inflator body  12  by a pivot pin  40  which passes through the inflator body  12 , a hole  42  located in the distal portion of the lever  38 , and a second slot portion  44  of an intermediate transfer pin  46 . The distal end portion  48  of the lever  38  has a cam extension  50  which forcibly engages the distal end  28  of the piercing pin assembly  20  when the lever  38  is pulled, thereby causing the gas-containing cartridge  22  to be pierced. A lanyard handle  52  is connected to the lever  38 . 
     The pivot pin  40  fixedly secures the actuator body assembly  14  to the inflator body  12 . The actuator body assembly  14  of the invention is generally comprised of an actuator body  54 , an actuator pin  55 , the intermediate transfer pin  46 , a conventional O-ring  56 , and a bobbin assembly  58 . A heavy spring  57  urges the head  55 H of the actuator pin  55  forwardly against the bobbin assembly  58 . 
     As better shown in FIGS. 1A-1C, the bobbin assembly  58  includes a generally cylindrical design with a center portion with longitudinal fingers  60  positioned parallel to each other and an outside wall portion  62 . An annular-shaped bobbin pill  64  with a center hole  66  is positioned between the outside wall portion  62  and the longitudinal fingers  60  to retain the fingers  60  in their longitudinal position. So long as the longitudinal fingers  60  are retained in their parallel position by the bobbin pill  64 , the tips of them form a seat for receiving the head  55 H of the spring-loaded actuator pin  55  and holding the spring-loaded actuator pin  55  back against the force of the spring  57  in a “cocked” position. 
     However, once the bobbin pill  64  is dissolved, the longitudinal fingers  60  are allowed to flex radially outwardly under the pressure of the spring-loaded actuator pin  55 . As they flex outwardly, their tips spread apart and no longer form a seat for the head  55 H of the actuator pin  55 , whereupon the actuator pin  55  is urged to move forwardly under the force of the spring  57  to actuate the pierce pin  20  via the transfer pin  46  (i.e., the actuator  10  is automatically “fired”). Thus, it can be appreciated that the bobbin pill  64  must have sufficient strength to hold-back the spring-loaded actuator pin  55  and yet must be dissolvable once exposed to water to allow the fingers  60  to flex radially outwardly and allow the actuator pin  55  to fire. 
     The first embodiment of the bobbin pill  64  of the invention is illustrated in FIGS.  2 A, 2 B and  2 C. As shown, the opposing distal and proximal surfaces  70  and  72  include undulations  74  with each peak  76  and trough  78  thereof extending radially from the center of the pill  64 . As best shown in FIG. 2B, the undulations  24  are out of phase with respect to each other by 180 degrees such that the peaks  76  and troughs  78  of the proximal surface  72  are respectively aligned with the peaks  76  and troughs  78  of the opposing distal surface  70  (i.e., the opposing peaks  76  and troughs  78  are aligned). 
     FIGS.  3 A, 3 B, and  3 C illustrate the second embodiment of the bobbin pill  64  of the invention, which is similar in configuration with the first embodiment, but with the undulations  74  of the distal and proximal surfaces  70  and  72  being oriented in-phase with each other (see FIG.  3 B). As such, the troughs  78  of the proximal surface  72  are aligned with the peaks  76  of the distal surface  70  and the peaks  76  of the proximal surface  72  are aligned with the troughs  78  of the distal surface  70  (i.e., the opposing peaks  76  and troughs  78  are not aligned). 
     The out-of-phase alignment of the undulations  74  on the distal and proximal surfaces  70  and  72  as shown in FIG. 2 is the most preferred. It is believed that the out-of-phase relative orientation provides as much compressive strength as the in-phase orientation of the second embodiment, but increases the rate of dissolving when exposed to water due to the aligned troughs  78  of the undulations  74 . 
     It is noted that due to the annular configuration of the pill  64 , the width of each of the undulations  74  formed on the surfaces  76  and  78  should narrow from the outside to the inside of the pill  64 , as best shown in the respective embodiments of FIGS. 2A and 3A. In this manner, as best shown in the respective embodiments of FIG. 2C and 3C, the distance between opposing troughs  78  (FIG. 2B) and between the opposing troughs  78  and peaks  76  is the greatest toward the center  66  of the bobbin pill  64  and radially decreases toward the outside of the pill  64 . This results in a frustro-conical cross-sectional configuration (i.e., a non-uniform configuration) that achieves greater compressive strength along the lumen of the pill  60  to better withstand the forces exerted by the fingers  60  of the bobbin assembly  58 . 
     FIGS.  4 A, 4 B, and  4 C illustrate the third embodiment of the bobbin pill  64  of the invention with the undulations  74  of the distal and proximal surfaces  70  and  72  being formed in a checkerboard configuration. As shown in FIG. 4C, the pill  64  comprises a non-uniform configuration  65  including a frustro-conical cross-sectional configuration. As noted above, this achieves greater compressive strength along the lumen of the pill  60  to better withstand the forces exerted by the fingers  60  of the bobbin assembly  58 . It is noted that although shown oriented out-of-phase with each other (see FIG.  4 B), the undulations  74  may be aligned to be in-phase similar to the in-phase alignment of the undulations  74  of FIG.  3 . 
     FIGS.  5 A, 5 B, and  5 C illustrate the fourth embodiment of the bobbin pill  64  of the invention with the undulations  74  of the distal and proximal surfaces  70  and  72  being oriented concentrically instead of radially as shown in FIGS. 3 and 4. The concentric undulations may be aligned to be out-of-phase as shown in FIG. 5C or in-phase (not shown). 
     FIGS.  6 A, 6 B, and  6 C illustrate the fifth embodiment of the bobbin pill  64  of the invention having a non-uniform configuration. More specifically, as best shown in FIG. 6C, bobbin pill  64  has a generally non-uniform cross-sectional configuration having a thinner outer edge  64 OE with a step  64 S and a thicker inner edge  64 IE that defines a generally frustro-conical cross-sectional configuration, preferably formed at a 10 degree angle. As such, the increased thickness of the pill  60  along the inside edge  64 IE that engages the fingers  60  of the bobbin assembly  58  significantly increases the ability to withstand the compressive forces thereof caused by the actuator pin  55  and spring  97 . 
     FIGS.  7 A, 7 B, and  7 C illustrate the sixth embodiment of the bobbin pill  64  of the invention having another non-uniform configuration similar to that of the fourth embodiment but with a double frustro-conical cross-sectional configuration. More specifically, referring to FIG. 7C, the double frustro-conical cross-sectional configuration includes thicker outer and inner edges  64 OE &amp;  64 IE and a thinner middle portion  64 M thereby defining the double frustro-conical cross-sectional configuration. As such, the reduced thickness of the pill  64  along its middle portion assures that it will easily dissolve when immersed in water. 
     The foregoing detailed description has been principally directed to pills for bobbins used in automatic inflators manufactured by the assignee of this invention. However, it should be appreciated that without departing from the spirit and scope of this invention, the above-described undulations and non-uniform configurations may be applied to pills of other designs (e.g., disk-shaped without a center hole, cylindrical-shaped, etc.) of other makes or models of inflators manufactured by third parties. For example, inflators manufactured by Bernhardt Apparatebau GmbH in accordance with U.S. Pat. Nos. 5,685,455, 5,562,233, 5,370,567, 5,333,756, 4,488,546, the disclosures of which are hereby incorporated by reference herein, typically utilize a disk-shaped pill that could be, in accordance with the present invention, adapted to include the undulations and/or non-uniform configurations described herein. 
     The chemical composition of the pill  64  is typically composed of microcrystalline cellulose that is compressed into the desired configurations. This composition is selected for its characteristics of being resistant to moisture from humid weather conditions while maximizing compressive strength. The method of compressing the powder into the pill  64  often produces an outer surface that resembles a thin skin that enhances the pill&#39;s  64  resistance to humid weather conditions. Indeed, chemical additives may be combined with the cellulose powder to enhance the pill&#39;s  64  resistance to humidity and increase its compressed forces. 
     The present invention includes that contained in the appended claims as well as that of the foregoing description. Although this description has been described in its preferred form with a certain degree of particularity, it should be 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, combination, or arrangement of parts thereof may be resorted to without departing from the spirit and scope of the invention. 
     Now that the invention has been described,