US3481514A

US3481514A - Combustion devices

Info

Publication number: US3481514A
Application number: US613807A
Authority: US
Inventors: Arthur Trevor Theobald
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-02-17
Filing date: 1967-02-03
Publication date: 1969-12-02
Anticipated expiration: 1986-12-02
Also published as: GB1156665A; DE1629926A1; BR6786602D0; DK133189B; FR1511896A; CH461407A; AT273548B; BE694161A; NL6702270A; DK133189C; SE309129B; NO123082B

Description

Dec. 2, 1969 A. T. THECBALD CoMBUsToN DEVICES 2 Sheets-Sheet 1 Filed Feb. 5, 1967 r ,.N \\\\\\\\\\\\\\Z n IoN. Iv. e NN 0 S Y MNHNHHMMMMMHHmmmIMd mwN ,Ilz \\\\\\\\\\N\\\\\\\ N .om

` INVENTO` Arthur Trevor Theobold 2 Sheets-Sheet 2 Dec. 2, 1969 A. T. THEOBALD COMBUSTI-ON DEVICES Filed Feb. 5. 1967 FIG. 4

United States Patent O COMBUSTION DEVICES Arthur Trevor Theobald, 23 Halepit Road, Great Bookham, Surrey, England Filed Feb. 3, 1967, Ser. No. 613,807 Claims priority, application Great Britain, Feb. 17, 1966,

Int. Cl. B65d 25/40, 5/ 72 U.S. Cl. 222-500 3 Claims ABSTRACT OF THE DISCLOSURE A metering device for small quantities of pyrophoric substance used to ignite a primary fuel, the device having a cavity containing the pyrophoric substance. The cavity is closed by a diaphragm which is mechanically associated with a discharge valve so that a sudden impulse against the diaphragm opens the valve and ejects a small amount of pyrophoric substan-ce into the ambient atmosphere adjacent a primary fuel stream.

This invention relates to combustion devi-ces and particularly to combustion devices for domestic use such as heat producing devices, light producing devices, gas wands, flame welding torches and cigarette lighters, in which the ignition `of fuel escaping from a burner is effected by the spontaneous combustion of a substa-nce which is pyrophoric when brought into contact with air or combustion fuel.

Since suitable pyrophoric substances are generally extremely expensive it is necessary to arrange that only a very small and accurately metered quantity of the pyrophoric substance shall be released to the atmosphere when it is desired to effect combustion of the fuel, and it is an object of this invention to provide an improved combustion device having manually operable means providing accurate metering of the pyrophoric substance.

The metering device for a pyrophoric igniter substance pursuant to the present invention comprises a valve housing provided with a cavity opening into one surface portion of the housing, a flexible diaphragm positioned to close the opening into said cavity, and an anvil member mounted centrally of the diaphragm and extending outwardly therefrom. The valve housing is further provided with a valve stem passage extending from said cavity to another surface portion of the housing, and a valve stem is positioned within said passage with one end of the stem communicating with the anvil member and the other end communicating with a valve member which is operatively associated with a valve seat. A source of pyrophoric igniter substance communicates with the valve housing cavity and the valve stem passage, and a hammer member is operatively positioned with respect to the valve housing so as to be movable toward and away from the anvil member. A hammer member operating means is further providing for causing the hammer member to strike the anvil member with a sharp impulse and thus inwardly deflect the diaphragm and unseat the valve member to discharge therefrom a discrete amount of the pyrophoric igniter substance.

The invention will be more readily understood from the following description taken in conjunction with the accompanying drawings in which:

FIG. l is a cross-sectional side elevation of a metering device embodying the invention;

FIG. 2 is a cross-sectional side elevation of another form of metering device embodying the invention;

FIG. 3 is a cross-sectional side elevation of still another form of metering device of the invention embodying a delayed action valve;

FIG. 4 is a front elevation, partly in section, of a lighter- "ice operating mechanism adapted to provide the impulse action to a metering device of the invention; and

FIG. 5 is a cross-sectional end view, partly broken away, of the mechanism shown in FIG. 4.

As shown in FIG. 1, the metering device comprises a valve housing 1 in which is formed a cavity 2 closed by a movable wall portion advantageously in the form of a flexible diaphragm 3 which may be made, for example, of a suitable plastic such as a polytetrauoethylene polymer, and which can be held in place by a conventional thread retaining ring B. One wall of the cavity 2 is also formed with an orifice A which is constituted by the end of a valve stem bore 4. This orifice is normally closedby a valve member 5 which is mounted on one end of a valve stem 6. The other end of' the valve stem 6 is appropriately secured to the diaphragm 3, for example, by means of two nuts 7 and 8 threadedly mounted on the valve stem 6 and between which the diaphragm is clamped. The valve member 5 is held in closed position by a compression coil spring 9 which extends between an inner wall of the cavity 2 and the inner diaphragm clamping nut 8. The outer surface C of the outer diaphragm clamping nut 7 forms an anvil member by which the metering device is actuated. i

In order that the valve housing cavity 2 may be supplied with a pyrophoric substance, the housing 1 is formed with a threaded supply bore 10 within which extends a hollow needle 11 communicating with the cavity 2. The pyrophoric substance can be under pressure such as its own vapor pressure, or an inert gas such as nitrogen can be used to pressurize the pyrophoric substance. The pressurized substance is provided in a conventional supply container which is formed with a threaded neck closed by a frangible seal such that, when the neck of the container is screwed into the threaded supply bore 10, the needle 11 pierces the seal and provides communication between the supply container and the valve housing cavity. At the end of the supply bore 10 is a sealing washer 12 to insure a fluid-tight connection Ibetween the container neck and the housing 1.

In the operation of the metering device shown in FIG. l, means is provided for striking the outer end of the anvil nut 7 a sudden blow so as to produce a momentary pressure rise in the chamber. When the nut 7 is struck, the valve stem 6 will move to unseat the Valve member 5 from the orifice 4. The simultaneous movement of the diaphragm 3 will set up a pressure rise in the atmosphere inside the chamber 2. A pressure wave will travel down to valve stem bore 4, and when the pressure rise reaches thev orifice a small quantity of the pyrophoric substance in the valve housing cavity will be ejected. The ejection of pyrophoric substance takes place rapidly, and after it has occurred the orifice will be firmly sealed by the valve member 5 before any significant amount of fuel or air can be drawn back into the valve stem bore.

In the modification of the invention shown in FIG. 2, the valve housing 1 is provided with a cavity 2 of sufficient size to receive a spool 13 on which is wound a number of layers 14 of porous sheet material such as fiber glass fabric or ne wire mesh whose interstices carry the igniter substance supply. One end of the spool body 15 is provided with an axially aligned spindle 16 having a central bore 17 communicating with an axial bore 18 in the spool body 15 and thus forming a single valve stem bore. The head 19 of the spool adjacent the spindle 16 is mounted in one end of the valve housing 1 by crimping or the like. The other head 20 of the spool fits within the interior surface of the valve housing and is provided with apertures 21. In order that pneumatic pressure applied through the apertures 21 can be transmitted to the valve stem bore 17, the spool body 15 is provided with radial apertures 22. The outer face of the spool head is contacted by the face of a pliable flanged grommet 23 having a stem portion 24 which is provided with a central bore communicating with the valve stem bore. A valve stem 6 is mounted within the resulting valve stem bore 4 and is provided with a head portion 25 at its end proximate the grommet stern portion 24 and with a valve member 26 at its other end adapted to engage a valve seat 27 at the outboard end of the spindle bore 17. A fiexible diaphragm 28 is mounted so as to close the valve housing cavity and is held in place 4by a peripheral retaining ring 29 and an inner double-flanged sleeve 30 surrounding the flanged grommet 23. The outboard fiange of the sleeve 30 is urged outwardly by a compression coil spring 31, and the head of the sleeve is provided with an anvil surface 32 overlying the head end 25 of the valve stem.

In operation of the device shown in FIG. 2, a sharp blow on the anvil surface 32 causes deflection of the diaphragm 28 and movement of the valve member 26 away from its valve seat 27. Deflection of the diaphragm creates a shock wave which is transmitted through the mass of igniter substance via the spool head apertures 21 and the spool body apertures 22 and causes a small amount of the igniter substance to be ejected from the valve.

In another modification of the metering device of the invention, the valve stem 6 is not secured to the diaphragm but terminates adjacent thereto so that when the diaphragm is moved inwardly it hits the end of the valve stem and thus displaces the valve member from the orifice. This modification is shown in FIG. 3 wherein the valve housing 1 is in the form of a cylindrical can one end of which is closed except for a central valve stem bore 4 through which the valve stem 6 extends. The valve housing cavity 2 contains a spool 33 both heads of which slidably fit within the cavity and the main body portion of which surrounds the valve stem 6 with sufiicient clearance to accommodate a compression spring 34, but which is secured at one end to the stem 6. The spool is Wound with igniter substance-impregnated sheet material 14 as in FIG. 2, and the body portion of the spool is provided with apertures 35 so that the igniter substance can be caused to flow from the body of impregnated sheet material into the space surrounding the valve stem 6.

In the device shown in FIG. 3, the open end of the valve housing 1 is closed with a flexible diaphragm 36 locked in place by a suitable retainer ring 37. An anvil-shaped member 38 having a stern portion 39 is mounted on the central portion of the diaphragm with the stern portion of the anvil member penetrating through the diaphragm. The inboard end of the stern portion 39` of the anvil member is secured to the inside surface of the diaphragm -by a retaining ring 40. The body of the anvil member 38 is provided with an axial bore 41 to accommodate the end of the valve stem 6 but deeper than the extension of the valve stern into the anvil member. Thus, when the anvil member is struck a sharp blow, it first defiects the diaphragm 36 to cause axial movement of the spool 33 and then, when the bottom of the anvil member bore 41 reaches the end of the valve stem, the anvil moves the valve stern to open the valve 42. This action causes a small metered amount of the igniter substance to be ejected from the valve only after a substantially increased internal pressure has been developed, and the coil spring 34 causes the valve 42 to close first on the return stroke.

It will be appreciated that a variety of mechanisms can be used to provide the sharp impulse or operating blow on the anvil member of the metering device of this invention. A particularly effective impulse-producing mechanism is shown in FIGS. 4 and 5. This mechanism comprises a two-piece case: one piece comprises a bottom plate 50, front and back plates 51 and a side plate 52; the other piece comprises a top plate 53, front and back plates 54 and a side plate S5. The two pieces of the case are hinged together by hinge pins 56 extending through adjacent overlapping front and

back plates

51 and 52 of the two case pieces. An impulse igniter device of the invention, designated as 57, is secured to the end plate 52 of one case piece with the valve end of the igniter device extending through this end plate. The other case piece is urged into an open position by a leaf spring 58 secured to the top plate 53 and pressing against the igniter device 57. A hammer member 59 is mounted in line with the anvil member `60 of the igniter device and is supported by a pivot piece `61 extending through both the front and back plates 51 and the hammer member. The pivoted hammer member 59 is urged upwardly and forwardly by a leaf spring 62, and a set-screw 63 extends through the hammer member perpendicular to its pivot axis so as to adjust the point in the hammer pivotal movement where it is desired for the hammer member to impart impulse contact to the anvil member `60 of the igniter device. The side plate 55 of one of the case pieces is provided with a nger spring 64 which bears against an upstanding pin 65 in the head of the hammer member. Thus, when the top plate 53 of the case is pressed downwardly toward the bottom plate 50, the finger spring 64 presses against the hammer pin 65 so as to tilt the hammer member 59 backward against the action of the leaf spring 62. As this tilting movement continues, the finger spring 64 will suddenly slide over the hammer pin 65 and the hammer member, thus released, will be driven upwardly and forwardly by the leaf spring 62 with considerable force against the anvil member 60 of the igniter device. As a result, a small but discrete amount of igniter substance will be metered out in the form of a spurt through the valve end of the igniter device. 'Ignition of the igniter substance, say by contact with the ambient atmosphere, takes place immediately and can be used to ignite a jet of fuel, such as butane, directed past the valve end of the igniter devicenfThe entire operating mechanism can therefore be secured by fasteners 66 to the body portion 67 of a fuel-containing device such as a cigarette lighter or the like.

The pyrophoric substance charged to the valve body cavity in the igniter device of the invention can be either normally gaseous or normally liquid, such, for example, as aluminum borohydride, trimethyl aluminum, lboranes such as diborane through pentaborane, silanes such as mono, di, and trisilane, dimethyl Zinc, carbonyl nickel, dimethyl boron, and the like.

A disadvantage of many arrangements proposed heretofore for metering a pyrophoric substance is that when the pyrophoric substance is being ejected it is possible for air to enter the space in which the pyrophoric substance is housed. The reaction of this air with the pyrophoric substance produces an ash which eventually builds up to the extent that the operation of the device is adversely affected by the valve controlling the egress of the pyrophoric substance sticking in its open position. This disadvantage is minimized With the construction of the present invention in that the rapid ejection of the pyrophoric substance and the sudden movement of the valve member to open the orifice only at a time when a positive pressure wave is adjacent the orifice allows little or no air to enter behind the valve member. The improved device has been found to be simple and efficient in operation and it enables a very economical quantity of pyrophoric substance to be delivered at each operation of the device.

I claim:

1. A metering device for supplying a pyrophoric igniter substance to the ambient atmosphere which comprises a valve housing provided with a cavity opening into one surface portion of the valve housing, a flexible closure member positioned at and closing the opening into said cavity, an anvil member fixedly connected to the flexible closure member exteriorly of said cavity, a spring member loading the fiexible closure member against inward action of the anvil member, the valve housing being further provided with a valve stem passage extending from said cavity to another surface portion of the valve housing, a valve stem positioned within said passage with one end of the stem communicating with the anvil member and the other end communicating with a valve member, a valve seat operatively associated with the valve member, a source of pyrophoric igniter substance communicating with the valve housing cavity and with the valve stern passage, a hammer member operatively connected to the valve housing so as to be movable percussively toward and away from the anvil member, and hammer memberoperating means adapted to cause the hammer member to strike the anvil member with a sharp impulse, whereby the sharp impulse by the hammer member against the anvil member inwardly deects the movable member and momentarily unsets the valve member to discharge therefrom a discrete amount of the pyrophoric igniter substance without permitting access of the ambient atmosphere to the valve housing cavity.

2. A metering device according to claim 1 in which the source of pyrophoric igniter substance is positioned within the valve housing cavity.

3. A metering device according to claim 1 in which there is lost motion between the anvil member and the end of the valve stem communicating therewith.

References Cited UNITED STATES PATENTS 2,015,158 9/ 1935 Rosenberg 222-91 2,980,296 4/ 1961 Edelstein et al. 222-70 3,018,056 1/ 1962 Montgomery 222-70 3,187,948 6/1965 Hunt 222-70 3,200,994 8/ 1965 Levinson etal 222-82 FOREIGN PATENTS 121,076 12/ 1918 Great Britain.

211,407 2/ 1924 Great Britain.

828,160 2/ 1960 Great Britain.

ROBERT B. REEVES, Primary Examiner