US3443907A

US3443907A - Gas-generating device utilizing a chemical composition candle

Info

Publication number: US3443907A
Application number: US568656A
Authority: US
Inventors: John W Mausteller
Original assignee: Mine Safety Appliances Co
Current assignee: MSA Safety Inc
Priority date: 1966-07-28
Filing date: 1966-07-28
Publication date: 1969-05-13
Anticipated expiration: 1986-05-13

Description

May 13, 1969 J. w. MAUSTELLER 3,443,907

GAS'NERATNG UlVC UTlLlZlNU A CHEMICAL COMPOSITION CANDLE Filed July 28. 1966 United States Patent O 3,443,907 GAS-GENERATING DEVICE UTILIZING A CHEMICAL COMPOSITION CANDLE John W. Mausteller, Evans City, Pa., assignor to Mine Safety Appliances Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed July 28, 1966, Ser. No. 568,656 Int. Cl. B01j 7/00; C01h 13/00 U.S. Cl. 23-281 7 Claims ABSTRACT F THE DISCLOSURE A chemical composition candle having embedded therein a pair of metal contact members, at least one of which is a prong projecting from one end. The contact members are electrically connected to an igniter in the candle. The candle is placed in a housing having an outlet for gas liberated by the burning candle. An end wall of the housing is provided with an electric socket receiving the prong when the wall is placed on the housing to close it.

This invention relates to devices for generating gas, and more particularly to the production of oxygen by burning sodium chlorate candles.

One way of producing oxygen for breathing purposes is to burn a chlorate candle that gives off oxygen. To ignite the candle, it has been the practice to embed a starting cone in it and to ignite the cone by means of a small coil of fine wire in the cone or by an electrically actuated chemical squib implanted in the cone. It also has been the practice to connect the ignition wires to larger wires that extend out through the wall of the container through a ceramic seal soldered into the wall. This arrangement has made it difficult to mount the candle in its housing and to replace it with a new candle after use. Also, the wires connecting the igniter with the outside circuit have interfered with arranging filtering material in the housing for filtering the oxygen produced.

It is among the objects of this invention to provide a gas-generating device of the candle type, in which the candle can be quickly and easily inserted in its housing and removed therefrom, and in which there are no wires that interfere with the oxygen filter.

In accordance with this invention, a gas-generating candle is placed in a housing provided with an end wall and with a gas outlet. An electrical connector is secured to the end wall and is provided with a socket that opens toward the opposite end of the housing. An electric igniter is embedded in the candle. A metal prong projects from an end of the candle. Also, a metal contact member projects from the candle. The contact member and prong are electrically connected with the igniter. The prong is slidably mounted in the connector socket in contact with the electrical connector. The contact member engages a conducting surface. with which the housing is provided and which, along with the electrical connector, is adapted to be connected in an electric circuit to supply current to the igniter.

The invention is illustrated in the accompanying drawings, in which FIG. l is a plan view;

FIG. 2 is a side View;

FIG. 3 is an enlarged longitudinal section taken on the line III-III of FIG. 2;

FIG. 4 is a cross section taken on the line IV-IV of FIG. 3; and

FIGS. 5 and 6 are reduced fragmentary longitudinal sections of two different modifications.

Referring to FIGS. 1 to 4 of the drawings, a candle housing 1 has an end wall 2 that can be permanently at- 3,443,907 Patented May 13, 1969 ICC tached to the rest of the housing or, as shown, be a removable closure. This closure can be attached to the housing in various ways, such as by a suitable clamp 3. The housing also is provided with a gas outlet, which preferably is an opening 4 in the center of the opposite end of the housing. Only one end wall of the housing needs to be removable. Disposed inside the housing is a candle 5 of sodium chlorate or the like, which, for best results, is spaced from the side wall of the housing by spacing members, such as parallel rods 6 attached to the inner surface of the housing.

It is a feature of this invention that after the candle has been inserted in the housing while the end closure is removed, attachment of the closure to the housing again will automatically connect the candle with electrical connectors that readily can be connected in an external electric circuit for igniting the candle. Accordingly, a pair of parallel stiff metal prongs 8 are embedded in an end of the candle, from which they project a short distance. Each of them is connected by a wire 9 to an electrically operated igniter 10 embedded in a starting cone 1l that is molded into the candle. The candle is inserted in the housing with the prongs located at end 2. To receive the projecting ends of the prongs, a pair of electrical connectors are rigidly secured to the housing end closure and are provided with sockets into which the prongs extend. At least one of the connectors may be formed from a socket member 12 of insulating material extending through an opening in the closure and sealed therein. Inside the socket there is a metal contact 13 or clip engaged by the adjoining prong and connected to an electric lead 14 extending out of the outer end of the socket member, in which it is sealed. The other electrical connector can be made in the same way. or it can be simply a metal socket member 15 engaged by a prong and rigidly mounted in the closure member, which is grounded when it is desired to ignite the candle.

With this construction, it will be seen that after the candle has been inserted in the housing the closure 2 is placed over the exposed end of the candle with the two electrical connector sockets in line with the prongs, and then the closure is pushed down on the prongs and housing and clamped in placed. Of course, there is a sealing ring 17 between the closure and the housing. When the closure member and lead 14 are connected in an external circuit, electric current flows through the two electrical connectors and prongs to ignite the candle so that it will start to generate oxygen.

It is highly desirable that the oxygen leaving this apparatus be filtered. For this purpose the outlet 4 of the housing is connected with a filter in a lter case. Preferably, the filter case is in the form of a cup 20 that receives a filter cartridge 21, which is held in place by a screw cap 22 on the case. The cap is provided with one or more openings 23, through which oxygen can escape after being filtered. The inlet of the filter case preferably is connected with outlet 4 of the candle housing by means of a short rigid tube 24 welded to both.

The candle should be spaced from the outlet end Wall of the housing, as well as from the side wall. One way of doing this is to mold another pair of prongs 26 in the end of the candle opposite the first pair. These additional prongs serve merely as spacers.

It will be seen that after the candle has been consumed the housing closure can be removed, the residue dumped out of the housing, a new candle dropped into the housing, and then the closure reattached. These are simple and easy operations. No wires have to be spliced inside the housing and there are no wires to interfere with filtering. The mere act of putting the housing closure in place electrically connects the candle to the outside of the housing.

In the modification shown in FIG. 5 one metal prong 3l, extending out of a candle 32 and electrically connected by a wire 33 to the starting cone 34, projects into an insulating socket member 35 mounted in the removable closure 36 of the candle housing 37 as before. Inside the socket the prong engages a metal contact 38 that is connected to a wire 39 leading out of the socket member. Unlike the first embodiment of the invention, this modification is not provided with a second socket member. Instead, the second metal prong 40 extends entirely through the candle but projects only a short distance from its upper end so that a wire 41 can connect it to the starting cone. The lower end of the prong projects from the bottom of the candle and engages the lower wall of the candle housing. In use, the housing is grounded so that there is an electric circuit through both prongs to the starting cone.

A still further embodiment of the invention is illustrated in FIG. 6. Here again the removable closure member 45 of a candle housing 46 is provided with only one electrical connector having a socket 47 for receiving a metal prong 48 projecting from the upper end of the candle 49. This prong is connected by a wire 50 to the starting cone 51. The other prong or rod S2 projects just far enough from the top of the candle to be connected by a wire 53 to the starting cone. Rigidly attached to the upper end of this rod is a spring metal clip 54 that is engaged by the housing closure when the latter is put in place. The starting cone therefore is grounded against the housing, as in the form of the invention shown in FIG. 5. An advantage of these last two embodiments of the invention is that only one electrical connector needs to be mounted in the housing end wall.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

l. Gas-generating apparatus comprising a housing provided with an end wall and with a gas outlet, an electrical connector rigidly secured to said end wall and provided inside the housing with a socket that opens toward the opposite end of the housing, a gas-generating chemical composition candle removably disposed inside said housing, an electric igniter embedded in the candle composition, a metal prong embedded in the candle composition and projecting from an end of it within the periphery of the candle, a metal contact member embedded in the candle composition and projecting from it, and means electrically connecting said igniter with said contact member and prong, said prong being slidably mounted in said socket in contact with said electrical connector, said housing being provided with a conducting surface engaged by said contact member, and said surface and electrical connector being adapted to be connected in an electric circuit to supply current to said igniter.

2. Gas-generating apparatus according to claim 1, in which said contact member is a spring contact engaging an inside surface of the housing.

3. Gas-generating apparatus according to claim 1, in which said contact member is a second Prong projecting from the end of the candle opposite to said lirst-mentioned prong.

4. Gas-generating apparatus according to claim 1, including a filter, and means connecting said outlet with the filter.

5. Gas-generating apparatus according to claim 1, in which said contact member is a second prong projecting from the same end of the candle as said rst-mentioned prong, and said conducting surface is the inner surface of a second socket carried by said housing end wall, and further including means projecting from the end of the candle opposite said prongs for spacing the candle from the adjacent end of the housing.

6. Gas-generating apparatus according to claim 1, in which said end wall is removable and said outlet is in the opposite end of the housing, a filter case is connected with the outer end of said outlet, and a filter is removably disposed in said case.

7. Gas-generating apparatus according to claim 6, in which said housing and case are rigidly connected together by a short tube forming a passage from said housing outlet.

References Cited UNITED STATES PATENTS 3/1966 Brooks 23-281 XR 10/1966 Moni et al. 2 3-281 U.S. Cl. X.R. 23-221; IGZ-70.2