US3512912A - Gas torch - Google Patents

Description

' R. E. LINCH May 19, 1970 GAS TORCH Filed Jan. 25, 1968 tNvENToiZ. ze E. /NCH ATT' D RN EYS United States Patent() U.s. Cl. 431-344 s claims ABSTRACT OF THE DISCLOSURE A portable torch utilizing pressurized gas fuel and provided with a replacable orifice member having a selfcontained filter element.

BACKGROUND Portable pressurized gas fuel devices such as liquid propane torches adaptable for a variety of uses are well known in the art. In such devices, it is important that a proper iiame be maintained while the device is operating on ia supply of the pressurized fuel which is supplied to the burner head through a minute orifice. The burner orifice thus provided in the device may be of varying sizes dependent upon the type of work to be performed and the nature of the ame necessary for the performance of such Work.

In these devices, it is customary to provide fuel flow and pressure regulating means so that the torch or appliance will operate properly in any position whether it be upright, tilted or inverted. For example, for the flow regulation, it is common practice to provide an adjustable needle valve or the like for use in establishing the desired torch or burner fiame, and for pressure regulation, diverse types of metering valves and/or flow retarders interposed in the fuel line between the supply source and the needle valve have been proposed.

In addition, it is customary practice to filter the fuel in advance of the burner orifice in an effort to minimize or eliminate clogging of the minute orifice by any foreign particles which might be contained in the fuel. For this purpose, various types of filters formed of a variety of materials have been heretofore utilized.

However, these prior filter elements have generally been built into the torch or other fuel burning appliance in such a manner as to be relatively inaccessible. Accordingly, if they should become ineffective due to clogging or the like, they cannot be readily replaced by a novice, and the torch is therefore frequently discarded and replaced in its entirety. Also, in many instances, the type of filter materials used are relatively ineffective for the intended purpose, and foreign particles will still find their way to the burner orifice and result in clogging and fuel flow interference and improper functioning. In still other instances, the placement and design of the filter elements is such as to result in inefficiency, sometimes causing the user of the device to employ a burner nozzle which is not intended or suited for the particular job at hand.

SUMMARYV It is therefore an object of the present invention to provide an improved filter element for a propane burner or the like which is highly efficient in actual use and which is readily accessible for periodic cleaning and/or replacement.

Another object of this invention is to provide -an improved filter element for a pressurized fuel burner which is built into and forms an integral part of the burner orifice member in a manner whereby maximum efficiency in burner operation is obtained.

lCC

Still another object of the invention is to provide aportable gas fuel burning device with an improved readily accessible and replaceable filtered orifice cartridge for the burner nozzle wherein the orifice is properly sized for a given job and the filter is positively positioned and retained relative to the orifice for maximum efficiency in intercepting foreign particles without interfering with the desired fuel flow through the orifice.

A further object of the present invention is to provide ia replacable orifice-forming and filter-containing cartridge for the nozzle of a portable fuel burner which comprises, a cylindrical shell having an outer circumferential flange at one end thereof and afuel orifice extending therethrough, and a sintered metal filter element secured Within the shell and extending outwardly beyond the end thereof remote from the flanged end.

These and other objects and advantages of the invention will become apparent from the following detailed description.

THE DRAWING A clear conception of the several features constituting the present invention, and of the construction and mode of operation of a typical propane hand torch embodying the improvements, may be had by referring to the drawing accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

FIG. 1 is an elevational view of a typical pressurized propane torch embodying the invention;

FIG. 2 is an enlarged fragmentary transverse section through the torch and burner assembly;

FIG. 3 is an enlarged exploded view, in section, through the burner nozzle; and

FIG. 4 is a further enlarged transverse section through one of the improved orifice-forming and filter-containing capsules embodied in the torch.

DETAILED DESCRIPTION Referring now to the drawing, the pressurized gas fuel appliance shown therein as embodying the invention is a etypical liquid propane torch designated generally by the reference numeral 10. The torch 10 is comprised generally of a cylinder 12 containing a supply of liquid fuel under pressure, a valve body 14 threaded to a cylindrical plug 16 carried by the cylinder 12, and a tubular neck or supply pipe 18 secured to and extending outwardly from the valve body 14 and equipped with a nozzle 20 at its outer end. For relieving excess pressures in the cylinder 12, a pressure relief valve 22 is provided.

The flame emanating from the nozzle 20 is adjusted by means of an adjustment valve 24 housed in the valve body 14 located between the cylinder or supply tank 12 and the nozzle 20. The typical fiame adjustment valve shown herein is in the form of a needle valve having a stem 26 threaded as at 28 into the valve body 14 and provided with an adjustment knob 30. The flow of fuel from the supply tank 12 to the nozzle 20 may accordingly be regulated by manipulating the adjustment knob 30. An O-ring seal or the like embraces the needle valve 26.

Thus, by turning the knob 30 in one direction, the nose portion 32 of the needle will be seated against the seat 34 to close the passageway 36 and shut off the supply of fuel from the supply tank 12 to the nozzle 20. By turning the knob 30 in the opposite direction, pressurized fuel will fiow from the cylinder or `supply tank 12 through the passageway 36 and into the burner tube 18 to the nozzle unit 20. The ame issuing from the nozzle 20, upon igniting the fuel delivered from the nozzle, may then be adjusted by rotating the knob 30 to the desired extent.

Referring particularly to FIG. 2 of the drawing, the valve body unit 14 is illustrated as being screw threaded upon the cylindrical plug 16 which has a central bore 38 extending therethrough. The bore 38 in the plug 16 is adapted to receive a valve unit 40 which is in the nature of the customary tire valve. This valve unit 40 is spring controlled so as to remain closed prior to insertion of the stem portion 42 of the valve body unit 14 Within the bore 38 of the cylindrical plug 16. Accordingly, the pressurized fuel supply cylinder or tank remains sealed until the burner valve and nozzle assembly is applied thereto, and these tanks 12 may therefore be sold and/0r merchandised as separate disposable units. Upon insertion of the stem 42 of the valve body unit 1,4 within the bore 38 of the cylindrical plug 16, the tire valve 40 is opened to thereby allow pressurized gas fuel to flow from the cylinder 12.

The stem 42 is provided with a bore 44 extending longitudinally therethrough, and the valve body unit 14 is threaded, as at 46, for receiving the stem 42. The valve body unit 14 containing the stem 42 is also provided with threads 48 for reception by the plug 16, and the stem 42 may be suitably sealed as at 50. Gas from the tank 12 is accordingly conducted past the valve 40 through passageway 44 of the stem 42 and then through passageway 36 past the needle valve 26 to the tube 18 and burner nozzle 20 as will hereinafter more fully appear.

In devices of this type, it is also customary to provide some type of valve means or pressure regulator for insuring a constant uniform flow of fuel from the tank to the burner nozzle regardless of the position of the torch or other appliance. One such device is shown and'described in detail in U.S. Pat No. 3,190,496y dated June 22, 1965 to John Weiland, Ir. et al., and, for purposes of illustration, such pressure regulating or gas metering device is also shown as being utilized in the present instance. Briefly, this device is in the nature of a metering diaphragm valve 52 spanning the upper or inner end of the passageway 44 of the stem 42. The diaphragm 52 is formed with an annular detent 54 and one or more apertures 56 located outwardly beyond the annular detent 54. Upon demand and with the needle valve 24 open, the pressurized gas passing through the passageway 44 acts upon the diaphragm 52 to raise the annular detent 54 from its normally seated position on the upper end of the stem 42 whereupon the gas is free to flow through the aperture or apertures 56 into the passageway 36 and past the needle control valve.

One end of the tube 18 is secured to the valve body 14 as by means of a plug 58 having a central bore 60 for receiving the tube 18, the plug 58 being externally threaded as at l62 for reception in the valve body 14 and the end of the tube 18 beyond the plug 58 being formed with a spherical abutment 64 preventing displacement of the plug from the tube while also providing a seat within the valve body. The nozzle assemblage 20 consists generally of a body 66 screw threaded as at 68 to the outer end of the tube 18 and having an air and gas mixing chamber 70 formed therein. The mixing chamber 70 formed in the body 66 communicates with the ambient atmosphere through a plurality of radial passageways 72 and has an axially extending passageway 74 through which the gas and air mixture is conducted to the interior of a cylindrical shield 76 secured to the body 66 in a suitable manner as by brazing or the like, the shield functioning to confine the flame emanating from the burner nozzle and, in some instances, also being provided with wall apertures 78 for admitting additional oxygen to the flame.

It is customary practice to provide means forming a restricted orifice between the mixing body 66 and the fuel supply tube 18 within the area of the burner nozzle. `It is also common practice in some instances to provide a filter in advance of the burner orifice for trapping any foreign particles which might be contained in the fuel. In some instances, this filter is located between the tube 18 and the valve body 14, and in other instances it has been proposed to locate the filter within the medial portion of the tube 18.

However, in the present instance, an orifice-forming and filter-containing capsule or cartridge 80 has been provided. This cartridge 80 comprises a cylindrical body or shell 82 having a central cavity 84 open at one end of the body, the other end of -the body being substantially closed but provided with a central restricted orice 86 communicating the interior of the shell -82 with the mixing chamber 70. The end of the shell 82 surrounding the Orifice 86 is provided with an enlarged head 88 providing a circumferential flange engageable with the end of the tube 18 and seated as at 90 in the body l66 about the mixing chamber 70 formed therein. A cylindrical body or pellet 92 is held captive in the chamber 84, and the cylindrical body 92 is in the nature of a sintered metal filter element preferably of about Q0 microns. This filter element 92 extends into the cavity or chamber 84 but terminates short of the end wall which contains the restricive orifice 86, the filter element 92 being sized so that it eX- tends outwardly beyond the opposite end of the shell 82 as at 94 and being tapered as at 96 at the extending end thereof. In order to positively retain the filter element 92 in proper position within the recess or cavity 84 of the shell 82, the end 98 of the shell wall may be crimped or bent upwardly to peripherally grip the filter element.

The orifice-forming and filter-containing capsule of the present invention thus provides an integral unit which is conveniently accessible upon removal of the nozzle body 66 from the tube 18 in an obvious manner. The tapering end 94 of the sintered metal filter element 92 provides an extensive area for the combustible gases admitted to the tube 18, and the chamber 100 formed between the inner end of the filter 92 and the adjacent end wall of the shell 82 permits free passage of gas through the full diameter of the filter element to the orifice 86, thus insuring that the full capacity of the filter element is utilized.

From the foregoing detailed description, it is apparent that a Variety of filter and orifice-containing cartridges 80 may be made available to the user of the torch, and depending upon the work to be performed by the torch, the proper cartridge may be selected. To remove the cartridge 80, it is only necessary to unscrew the burner head 66 and remove the same from the tube 18. The cartridge 80 may then be freely removed from the end of the tube and may be replaced by the cartridge having the desired orifice. The cartridge is properly secured in position by seating the ange-forming head 88 on the end of the tube and then firmly screwing the nozzle assemblage 20 back onto the' tube whereupon the portion 90 of the cartridge is seated against the adjacent surface of the burner body 66 around the mixing chamber 70. The improved devices have gone into actual commercial use and have proven highly satisfactory and extremely eicient.

I claim:

1. A portable gas fuel device comprising, a container for pressurized fuel, a valve body receivable by said container and having a fuel passage therethrough communicable with the interior of said container, valve means adapted to be manipulated to open and close the fuel passage, a burner tube extendingnfrom said valve body in communication with the fuel passage, a burner nozzle removably secured to the end of said burner tube remote from said valve body, and a cylindrical member containing a filter element and having a burner orice in one end thereof communicating with said nozzle and said burner tube by way of said filter element, said filter element being sized and retained by said cylindrical member so as to project freely therefrom into said burner tube remote from said nozzle, the end of said filter element located in the burner nozzle terminating a spaced diS- tance from the cylinder member end containing the orifice to provide an open unobstructed chamber between the filter element and the orifice containing end, said cylindrical lter containing member having a head surrounding the orifice and providing a flange seated on the end of the burner tube between said tube end and the burner nozzle, whereby said cylindrical member is retained in position by said burner nozzle.

2. A portable gas fuel device according to claim 1, wherein the lter element is a sintered metal pellet medially clamped against displacement within the cylindrical member.

3. A portable gas fuel device according to claim 1, wherein the projecting end of the filter element is axially tapered.

References Cited UNITED STATES PATENTS lo `EDWARD G. FAVORS, Primary Examiner U.S. Cl. X.R.

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