US2904218A

US2904218A - Automatic inflator for life preserving apparatus

Info

Publication number: US2904218A
Application number: US559804A
Authority: US
Inventors: Harry L Pontious; Edward L Caustin
Original assignee: North American Aviation Corp
Current assignee: North American Aviation Corp
Priority date: 1956-01-18
Filing date: 1956-01-18
Publication date: 1959-09-15
Anticipated expiration: 1976-09-15

Description

Sept. 15, 1959 H. L.. PoNTloUs ET AL 2,904,218

AUTOMATIC INFLAToR FOR LIFE PRESERVING APPARATUS 2 Sheets-Suse?.

Filed Jan. 18, 1956 FIG. 2

FIG. l

INVENToRs HARRY L. Pormous EDWARD L. cAusTlN ATTORNEY Sept. 15, 1959 v H. L. PoNTlous ETAL 2,904,218 AUTOMATIC INFLATOR FOR LIFE PRESERVING APPARATUS Filed Jan. 1e, 195e 2 sheets-smet 2 FIG. 6

ATTORNEY known in the art.

AU'IMATIC INFLATOR FOR LIFE PRESER'VING APPTUS Harry L. Pontious, Los Angeles, and Edward L. Caustn, Hawthorne, Calif., assignors to North American Aviation, Inc.

Application January t18, 1956, Serial No. 559,804

2 Claims. ((21.222-5) This invention relates to an iniiating device for oatation equipment and in particular relates to an inator for .life preserving equipment which operates 'quickly kand automatically to Vinflate such equipment upon immersion in '-water.

Many types of automaticlife `preserver inators are devices for puncturing a pressurized `gas cartridge and `causing the gas contained ,therein to be releasedto-inllate the preserver. Some such devices utilize a water soluble tablet for holding the trigger mechanism'in an inoperative vposition until the tablet 'is dissolved upon contact with Most of these use varioustriggering other devices use a pressure operated triggering 'means that requires the generation of a considerable gas pressure for its operation. Some ofthe latter devicesalso have the disadvantage `ot requiring sugmergen'ce to an appreciable predetermined depth in order to` commence actuation of the gas generating means. In addition to th'e various special requirements, Asome of which are -set out above and which are 'necessaryto the operation of many of these triggering devices,vmose of .these mechanisms do not operate with suicient rapidity torend'er themV fully effective for` inflating life'preserving equipment in the shortest possible time'.

The present invention contemplatesf'the use of a dependable, gas actuated, spring-loaded triggermechanism foruse with the standard typecarbon 'dioxide' cartridge and: holder in use by U.S. armed forces. VIt utilizes a fast acting chemical tablet designedto produce suic'ient noncombustible gas,'upon contact with Va singledrop of water, to be able to operate the trigger mechanism within a few seconds. The triggering vmechanism is so lightweight and compact as to be able to tinto the same` pocket on the Armed Forces Mae West`fty`p`e life preserver that is presentlyl used for storingonlythe manually operated gas cartridge and holder. Y l

Accordingly it is the principal object of this invention to provide a reliable, positive acting means for `automatically inilating life preserving apparatus upon 'immersion in'water.

It is another object ofthis invention to 'provide an inilator that is not dependent for actuation upon its position -or depth of submersion in the water.

pendable in operation and which may be comfortably worn with a life preserver of the Mae West type.-

These and other objects and advantages of the vpresent invention will become apparent tothose skilled in the art after reading the present specification and the accompanying drawings forming a part hereof, in which:

Fig, 1 is a side elevational view of the automaticxinator of this invention showing the plunger and trigger lever in a fired position.

Fig. 2 is a top plan view of the automatic inator :as connected to an inatable life preserver.

Fig. 3 is a side elevational View, partly in cross section showing the spring loaded plunger and the cartridge piercing pin mechanism, all ina cocked position.

Fig.` 4 is a fragmentary sectional View taken in'the plane of line 4 4 in Fig. 2 showing the piston operated latching mechanism in a cocked position prior to activation.

Fig. 5 is a fragmentary transverse sectional yview taken in the plane of line 5-5 in Fig. 1 showing the piston operated latching mechanism in a fired position withthe spring biased plunger released for movement downwardly.

Fig. 6 is an elevational view of the exible apper inlet valve.V v

Referring specifically to the drawings, wherein `like reference characters have been used'throughout the'several views to designate like parts, and' referring atrst-to Fig. 2 numeral 10 designates an inatable life preserver in the form of a vest or Mae West type of -life jacket of standard construction. A commercially available cartridge 11, shown in Fig. 3, is charged with -a compressed gas, such as carbon dioxide, and sealed' by a puncturable disk 16. Gas cartridge 11 is tted within a standard commercially available holder 12 having afthreadedly engaged head 13 removable for replacement of spent'carw tridges.V A piercing pin or element 14 is'longitudinally slidable relative to cartridge 11V whereby 'it may `be made .to puncture disk 16 and release the pressurized gas linto casing chamber 47 which communicates with the interior of the life prcserver through passage 34. A bellcrank type lever or trigger 15 is pivotally mounted atthe'lower end'of holder 12 and has a cam portion 48 bearing on the lower end of piercing pin 14, with the outer end 49--of lever 15 being manually operable toforce spring loaded pin 14 into piercing relationship with cartridge 11 and thereby release the compressed' gas and inate they life preserver. The above `described cartridge andhol'derare of the conventional manually operated type standard with the U.S. Armed Forces.

ln accordance with the present invention thereis'provided a trigger mechanism 17 for automatically actuating lever 15 upon immersion in water and adapted 'to bedetachably clamped to the standard cartridge holder- 12. Trigger mechanism 17 comprises an elongated housing 1S having transversely extending C-clamps 55 spaced along the housing. Complementary C-clamps 56 yare adapted to be bolted to matching clamps 55 and-coact therewith to attach housing 18 to holder 12. A loosely fitting plunger 19 is slidably mounted in cylindrical bore 20 for longitudinal movement therein. The 'lowerfend of bore 20 is closed by end wall 21 centrally apertured for passage of plunger 19.V The upper end of housing -18 is interiorly threaded for closure by threaded plug-33. Plunger 19 has an axially aligned counterbore 22 extending downwardly from the upper end thereof.

A button 23 has a stem threadedly engaging the lower end of the plunger and bearing on the outer end 49 vof lever 15. By removing button 23 and plug 33 plunger 19 may be withdrawn from housing 18 for-cleaning `after immersion in water. A shoulder or lip 27 is formed'ion the exterior of ythe plunger at the upper endthe'r'eof.

offset from the longitudinal axis of bore 20, projects transversely from housing 18 near its upper end. Boss 31 is yexternally threaded for engagement with interiorly threaded cap 35 and forms therewith a piston chamber 37. Cap 35 compresses an O-ring 53 against shoulder 54 to provide a pressure-tight seal for chamber 37. Cap 35 also has an axially concentric inlet port 36 in the cap end thereof, with a removable flexible apper valve 40 held in position against the inner surface of the cap end by annular retaining ring 41.

The entrance passageway 24 leading to port 36 in the end of the cap has a smooth round edged substantially `tapering configuration forming an airfoil like surface.

This airfoil shaped surface has an important elfect on the prompt actuation of the flapper valve. When moved `relative to the water this surface acts similarly to the diverging portion of a venturi tube, so that as trigger mechanism 17 is dropped into the water either vertically or with port 36 in an upwardly facing direction, water tends to ilow over the airfoil-like surface and inwardly against flapper valve 40'thereby opening the valve and allowing water to flow into chamber 37 and contact chem- -ica1 tablet 52. This venturi-like characteristic of passageway 24 insures prompt and positive operation of the flapper valve and causes the ow of water therethrough into chamber 37 under action of the hydrodynamic forces created by the ow of water over the airfoil-like surface. If the trigger mechanism 17 is tilted, upon entering the water, so that the passageway 24 and port 36 are facing -downwardly from a horizontal plane, the flapper valve 40 will be directly contacted by the water and opened by Vthe force of the impact thereon. Additionally valve 40 is of such a flexible resilient construction that it will be opened by an extremely small hydrostatic pressure there- 'on and need not be immersed to any considerable depth before it will open to admit the liquid. Thus it is evident that flexible apper valve 40 will admit liquid into chamber 37 under the slightest hydrodynamic or hydrostatic pressure. p

Upon actuation of the gas generation means valve 40 will close tightly and seal inlet port 36 under pressure of the gas generated within chamber 37. Any suitable material may be employed for the flapper valve but an oil resistant composition such as neoprene is particularly adapted for this purpose.

4Cylindrical piston stem bore 42 extends from the inner end of chamber 37 transversely through housing 1S and 'substantially tangentially intersects and opens at 32 into bore 20 near one end thereof. Bore 42 is axially concentric with the extended longitudinal axis of chamber 37 but is offset or eccentric to the longitudinal axis of bore 20.

A piston 38 is reciprocably mounted in chamber 37 and has a peripheral groove 43 for a piston seal ring 44 seated therein. Piston seal ring 44 may be of any suitable material but is also preferably of an oil resistant material such as neoprene. Integral with piston 38 cylindrical piston stem 39 extends reciprocably into bore 42. With piston 38 in its outermost or cocked position end portion 46 of stem 39 projects tangentially into bore 20, near the edge thereof, and supports plunger 19 under shoulder 27 whereby downward movement of the spring biased plunger is restrained. However, at an intermediate location on stem 39, predetermined by the position of the integral piston and stem when it has been forced inwardly by the gas pressure generated, a portion 45 of the stern ,is reduced in diameter suciently to allow shoulder 27 ,4 of the plunger to clear the reduced portion when it is opposite bore 20.

Thus it is evident that stem 39 and integral piston 38 comprise a latching or restraining mechanism for retaining the spring biased plunger in a cocked position near the upper end of housing 18. Upon actuation of the piston inwardly toward the housing body under pressure ofY gas generated in piston chamber 37, the latching mechanisrn is released and spring 2S forces plunger 19 down wardly to actuate trigger lever 15 and thereby move piercing pin 14 to puncture disk 16 and release the gas compressed in cartridge 11.

Since the automatic operation of a life preserver inating device is designed for situations wherein the person wearing or using the life preserver is unconscious or otherwise unable to operate the intlating device manually, speed in actuating the mechanism is of the utmost importance. Although any suitable chemical tablet may be used to generate a gas, in the preferred embodiment an effervescent tablet comprising 60% dry tartaric acid and 40% sodium bicarbonate is utilized. 'I'his tablet is ordinarily able to lire the inflator in less than ten seconds after contact with a single drop of water. This soda-acid type tablet liberates a non-toxic, non-combustible gas. This is an extremely important and desirable characteristic in view of the fact that life preserving equipment of this type must often be used in or around highly intlammable materials such as fuels floating on the surface of water in the vicinity of a damaged ship or aircraft. Most of the existing types of intlator mechanisms that depend on the generation of a gas for their operation utilize a calcium carbide tablet to form highly combustible acetylene gas upon contact with water. The use of such a combustible and inllammable gas is extremely dangerous in the above circumstances.

In operation the standard cartridge having the intlator mechanism of this invention securely attached thereto would normally be operated by the user by manually pulling down on pull cord 50 attached at the outer end of trigger 15 with a button 51 mounted on the end of the cord. This operation will move lever 15 to drive piercing pin 14 to puncture cartridge 11 and release the pressurized gas contained therein to inflate the connected and communicating Mae West or life preserver.

In the event the user has not manually inflated the life preserver shortly after being immersed the automatic trigger mechanism 14 will perform this function. Under the slightest hydrodynamic or hydrostatic pressure apper valve 40 will open to admit water into chamber 37, chemical tablet 52 reacts with the water to effervesce and release a gas. The gas pressure generated in the chamber seals valve 40 against the interior of the end of cap 35. The gas pressure increases rapidly until it exerts a force on piston 38 suicient to overcome the frictional force exerted by the shoulder 27 of the spring biased plunger on piston stem end portion 46. This required force is in the range of from 5 to 8 pounds. When this frietional force is exceeded piston 38 and integral piston stem 39 move inwardly and reduced piston stem portion 45 is thus positioned at a point opposite bore 20. This reduced portion 45 of the piston stem is of such size as to allow plunger shoulder 27 to pass by the reduced portion of `the stem. When this occurs spring 28 drives plunger 19 and attached button 23 forcefully downwardly against the outer end 49 of trigger 15 and thus actuates piercing pin 14.

To cock the trigger mechanism piston 38 must be at its innermost position with reduced stem portion 45 opposite bore 20. Plunger 19 may then be forced up into bore 20'until plunger shoulder 27 is above piston stem 39. The stem is then pushed to the left, by means of projecting stem end portion 46, to its cocked position wherein the lower edge of shoulder 27 will bear on the top surface of end portion 46 and the piston is at its outermost position. Cap 35 is disengaged from'boss 31 and a chemical tablet 52 is inserted therein so as to be positioned between inlet valve `40 and piston 38 when the cap is threadedly replaced on the boss. Trigger 15 is then moved in a clockwise direction until the outer end 49 bears against plunger button 23. Upon removal of the spent cartridge from holder 12, insertion of a charged cartridge therein and replacement of holder head 13 the inator unit is once more ready for automatic or manual operation.

While a particular embodiment of this invention has been illustrated and described herein, it will be apparent that various changes and modications may be made in the construction and arrangement of the various parts Without departing from the spirit and scope of this invention in its broader aspects or as defined in the following claims.

We claim:

1. An inliating device for pneumatic lloatation apparatus for both automatic and manual actuation comprising a sealed inflation gas cartridge mounted in a holder having a relatively movable piercing element therein adapted to contact said cartridge and communicating with the lioatation apparatus, a lever pivotally mounted on said holder having one end contacting said piercing element for actuating the same to puncture said cartridge, a housing having an axially extending bore therein open at one end in juxtaposition to said cartridge holder; a plunger slidably mounted in the `axial bore in said housing having an outer end operatively contacting the other end of said lever; a spring in said housing biasing said plunger outwardly of the housing in an axial direction to pivot the lever and actuate said piercing element; a body integral with said housing having a piston chamber therein normal to said housing axial bore, said housing having a cylindrical bore therein communicating with the piston chamber and axially coincident therewith extending through said housing and intersecting and cornmunicating with the housing axial bore; a piston reciprocal in said piston chamber; a stem on said piston extending in to the cylinder bore and forming an interference latch means retaining said spring biased plunger against axial movement when said piston is at one end of its travel, said piston stem having a reduced diameter portion permitting unlatching and axial movement of the spring biased plunger when the piston is positioned at the other end of its travel, said piston chamber having an opening permitting entrance of Water therein and a apper valve thereover adapted to close said opening when acted upon by gas pressure within said piston chamber; an effervescent tablet in said piston chamber capable of rapidly generating sulicient noncombustible gas upon contact with a slight amount of Water -to close said flapper valve and operate said piston to drive said stem latching means to an unlatched position whereby said lever may be pivoted by the spring biased plunger to actuate the piercing element; and means for actuating said piercing element manually.

2. An automatically and manually actuable iniiating device for pneumatic oatation apparatus comprising a sealed ination gas cartridge mounted in a holder having a relatively movable piercing element therein adapted to contact said cartridge and communicating with the oatation apparatus; a lever pivotally mounted on said holder having one end contacting said piercing element and adapted to actuate the same to puncture said cartridge; a housing having an axially extending bore therein open at one end attached to said cartridge holder; a plunger slidably mounted in the axial bore in said housing having a piston portion and a reduced diameter piston rod portion, said piston rod portion extending exteriorly of the housing bore and having an end portion contacting the other end of the pivotally mounted lever; a spring in said housing biasing said plunger outwardly of the housing in an axial direction to pivot the lever and thereby actuate said piercing element; a body integral with said housing having a piston chamber therein normal to said housing axial bore; said housing having a cylindrical bore communicating with said piston chamber and axially coincident therewith extending through the housing and tangentially intersecting and communicating with said housing axial bore; a piston reciprocal in said piston chamber; a stem on said piston extending into said cylinder bore and forming a latch means retaining said plunger against axial movement by engaging the piston portion of said plunger when the piston is at one end of its travel, said piston stem having a reduced diameter portion permitting unlatching and axial movement of the spring biased plunger when the piston is positioned at the other end of its travel, said piston chamber having an opening therein with a venturi-like tapered entrance configuration for inducing flow therethrough upon relative movement of water past the inlet; a resilient apper valve covering said inlet and adapted to open under the slightest water pressure and to close when acted upon by gas pressure within said piston chamber; and an effervescent tablet in said piston chamber capable of rapidly generating sufficient noncombustible gas upon contact with a slight amount of water to close said apper valve and operate said piston to drive the stem latch means to an unlatched position whereby said lever may be pivoted by the spring biased plunger to actuate the piercing element, said etervescent tablet comprising essentially dry tartaric acid and 40% sodium bircarbonate; and means for actuating said piercing element manually.

References Cited in the iile of this patent UNITED STATES PATENTS 1,367,225 Barker Feb. 1, 1921 2,349,480 Walk May 23, 1944 2,378,613 Young June 19, 1945 2,675,144 Eukann Apr. 13, 1954 2,722,342 Fox Nov. 1, 1955 2,786,599 Highee Mar. 26, 1957