US2093034A - Blowpipe lighter - Google Patents

Description

S p 1 H. WLCOWIN ET AL BLOWPIPE LIGHTER Filed Aug. 9,' 1934 a2 3 38 v as 'l 4/ z/ INVENT6R HERBERT w. cowm QNYILGOT I IACOESSON ATTORNEY Patented Sept. 14, 1937 UNITED STATES PATENT OFFICE BLOWPIPE LIGHTER Application August 9, 1934, Serial No. 739,092

17 Claims.

This invention relates to a fluid fuel burner and more particularly to an improved pilot light for such a burner which will consume a minimum amount of fuel and yet be always ready for lighting the burner.

It is desirable to have available a pilot light for lighting burners when they become extinguished, and it is necessary that such pilot lights remain lighted continuously during intermittent use of the burner. Economy in the amount of fuel consumed by the pilot light is frequently an important factor, and when this requirement exists it is necessary to maintain the continuously burning pilot light with as small a flame as possible. The danger always exists, however, that the small flame may be extinguished by drafts, and it therefore, becomes necessary to shield the pilot flame against such drafts. On the other hand, with the use of some fluid fuels, such as acetylene, restriction by a shield of the air coming to the pilot burner is a serious handicap since sufllcient air must be supplied to the pilot light burner when the flame is enlarged for lighting ,the main burner. It is necessary therefore, to shield the flame and at the same time to make sure that sumcient air will reach the pilot light burner under all conditions of operation.

From the foregoing discussion it will be evident that the invention is particularly useful in connection with a lighter for blowpipes such as those employed in welding, cutting or deseaming metals. In the use of such blowpipes one operation after another is performed; but between successive operations it is highly desirable temporarily to shut oif the welding or heating gases for the sake of fuel economy.

One object of this invention, therefore, is to provide means for shielding the pilot flame from drafts which may extinguish it, thereby permitting a minimum gas consumption when the main burner is not in use, and at the same time to provide ample air for the enlarged or extended flame required for lighting the main burner. Another object is the provision of metering means in the pilot burner construction in order to prevent undue fuel consumption. A further object is the screening of the fuel coming to the metering means and the pilot light nozzle. Still aand the accompanying drawing which illustrates one embodiment of the invention, and in which:

Fig. 1 is a broken longitudinal elevation of a blowpipe embodying the invention;

Fig. 2 is a partial longitudinal mid-section illustrating one form of the invention;

Fig. 3 is a partial longitudinal mid-section corresponding to Fig. 2 illustrating a variant form of the invention; and

Fig. 4 is a fragmentary cross-section showing certain related parts of the blowpipe construction.

The embodiment illustrated in the drawing shows the invention as applied to an oxy-acetylene blowpipe, but it will be realized that the invention is applicable to other forms of fluid fuel burners.

In. the drawing there is shown a blowpipe comprising a handle 10, having a valve body section II at its rear end, together with a lever l2 for controlling the heating flame, anda valve knob l3 for controlling the cutting oxygen. A stem section I4 connects the handle ill with a head I5 to which is attached a tip I6 in the usual manner.

It is preferred to place the pilot burner close to the underside of the head I5 at some distance from the end of the nozzle ,in a position to protect the burner from knocks, heat from cutting and slag. Thus, a bracket i1 is carried by the stem H in any convenient manner and is here shown as being clamped by means of bolts ill to one of the conduits l9 comprising the stem M. The bracket IT has a bore 20 through it; and a fuel conduit 2| communicates with the bore 20 in the bracket, for instance, by having the end of the conduit inserted in an enlarged section 22 of the bore and soldered therein. The fuel conduit 2i may be connected with any source of fluid fuel and in an acetylene blowpipe such as that here illustrated, is preferably connected with the source of acetylene in the valve body.

The bracket I! has a projection 23 thereon extending generally toward the far end of the tip 6 of the blowpipe. The bore 20 in the bracket extends through and to the end of this projection, which is both externally and internally threaded substantially concentrically with the bore. Thus, acetylene coming to the bracket through the fuel conduit 2| may pass through the bore 20 in the bracket and out of the threaded end of the projection 23 thereof. A pilot light nozzle 24 externally threaded at one end may be screwed into the internal thread at the end of the projection 23 of the bracket l1, and a substantially axial fuel passage 25 in the nozzle will thus be brought into communication with the end of the bore 20 in the bracket from which it will receive the acetylene passing through the bore. There is also provided in the nozzle 24 one or 5 more air passages 26 disposed at an angle to the fuel passages with an external opening or external openings in the surface of the nozzle. The axial fuel passage 25 having a'constricted throat 21 through which fuel coming to the nozzle must 10 of theair passages 26, an aspirating action will be exerted by the fuel 'upon any air in the air passages 26 which will be mixed with the fuel and projected from the end of the nozzle 24.

Normally, acetylene coming to the pilot light nozzle 24 will be restricted to a minimum quantity to keep the light burning. One means for controlling the access of acetylene to the pilot light nozzle is illustrated by the construction shown in Fig. 4. In this arrangement acetylene enters the passages in a valve block 28 through a conduit 28 and passes through a bore 30 to a duct 3| at the end of which a valve 32 is positioned to control the rate of flow of the acetylene. A valve stem 33 connects the valve 32 to a threaded portion 34 which turns in corresponding threads in the valve block 28. The position of the valve 32 is adjusted by turning a head 35 having a kerf 36 therein, the head being fast to the threaded portion 34, the head 35 having therebeneath a washer of such resiliency that it will maintain contact between the block 28 and the head 35 for varying positions of the valve 32. Acetylene passing the valve 32 enters a valve chamber 31 and passes thence through a. duct 38 to the fuel conduit 2|. Thus, by turning the head 35 in one direction the amount of acetylene reaching the pilot light nozzle 24 will be lessened, whereas turning the head 35 in the other direc- 40 tion will increase the amount of acetylene reaching the pilot light nozzle. It is desirable to adjust the head 35 in such a manner as to provide a minimum amount of acetylene to the nozzle 24 and a minimum length of flame at its end.

A second valve is provided in the valve block 28 for effecting a rush of fuel to the pilot light nozzle 24 and thus extending the flame to such a length that it will project in front of the blowpipe nozzle l6 to light the gases issuing there- 50 from. This second valve arrangement comprises a hollow nut 38 having a valve seat 40 at its lower end and being adapted to screw into a threaded cavity 4| in the valve block 28. A central passage 42 through the hollow nut 38 connects with the 55 duct 38 by means of a. plurality of radial passages 43 extending therefrom to an annular space 44 formed between a recess in the hollow nut 38 and the valve block 28. The annular space 44 opens into the duct 38. A valve 45, carried by a valve stem 46 which is threaded at the end thereof opposite the valve 45 and screwed into an annular bushing 41 in a button 48, seats upon the valve seat 40, thereby normally closing the central passage 42 against access of fuel from the bore 30. A helical spring 48 in the hollow nut 38 bears upon the bushing 47 and tends normally to maintain the valve 45 in closed position.

When it is desired to use the pilot flame to light the gases issuing from the tip Hi, the button 48 7 is pressed inwardly thereby opening the valve 45 and permitting an inrush of fuel gas which passes into the central passage 42 through the radial passages 43 to the annular space 44 and through the duct 38 to the fuel conduit 2|. The sudden 75 rush of fuel gas passes through the constricted pass immediately before passing the inner ends' throat 21 and out through the axial fuel passage 25 with great velocity. The jet of flame is thus elongated by many times its original length, and, because of the rate at which it passes through the constricted throat 21, aspirates a large quantity of air which passes through the air passages 26 at an accelerated rate.

As best illustrated in Fig. 1, the pilot light control means is preferably located in the front handle bushing in sucha position that the button 48 may be easily operated by pressure from the thumb of the hand holding the blowpipe.

In order to protect the normally small flame at the end of the nozzle 24 there is provided a shield 50, here illustrated as a hollow cylinder. One end of the shield 58 is internally threaded and is of such diameter that it may be screwed upon the externally threaded end of the projection 23 on the bracket I]. When the pilot light is used for lighting the gases issuing from the nozzle l6 and the rush of fuel gas is projected from the nozzle 24, it is necessary to supply quickly to the nozzle a greatly increased volume of air. This is especially the case where acetylene is used and a cloud of smoke will be formed unless sumcient air is present. Accordingly, a hole 5| is made in the shield 50 opposite the external opening of each air passage 26. Movement of air through the holes 5| will not tend to extinguish the flame at the end of the nozzle 24 because of the position of the holes in the shield; which serves to protect the flame at the end of the nozzle 24 in the desired manner. However, when the pressure in the air passages 26 is reduced the holes 5| provide means for access of an ample supply of air to the passages 28.

In order further to restrict the quantity of fluid fuel consumed by the pilot light when not in use a metering orifice may be provided between the supply of fluid fuel and the pilot light nozzle 24. One means of providing such a nozzle is to insert between the bracket I1 and the pilot light nozzle 24, a nipple wherein a metering orifice is formed, and such a construction is illustrated in Fig. 3 of the drawing. As shown in Fig. 3, a nipple 52, having a bore therein internally threaded at one end, is screwed upon the external thread of the bracket H. The nipple 52 has a metering orifice 53 therein in continuation of the bore and is internally and externally threaded at one end like the projection 23. The pilot light nozzle 24 is screwed into the internal thread in the outer end of the nipple 52, and a shield 50 is screwed upon the external thread at the outer end of the nipple protecting the pilot light nozzle 24 as previously described. The resistance provided by the metering orifice 53 limits the volume of fluid fuel reaching the pilot light nozzle and requires an appreciable pressure within the bore of the nipple to cause passage of any considerable quantity of fuel through the nozzle.

It has been found that impurities are frequently carried by the fluid fuel. These impurities may be solids or even globules of liquid, and if allowed to reach the metering orifice or the constricted throat 21 in the pilot light nozzle will tend to clog its passages and prevent proper operation of the apparatus. Accordingly, one or more screens may be inserted in the bore of the nipple 52, and as here shown two screens 54 and 55 are so inserted, the screens themselves being conical in shape and having their apices pointing in the direction of fuel travel. The base edges of the Screens are flared outwardly in the form of annular flanges and are held in place between an interior annular shoulder in the bore of the nipple and an externally threaded bushing I! screwed into the internal threading in the nipple 52. The screens 54 and 55 have different conical altitudes thereby providing a space between them so that the fluid fuel is twice screened before reaching the metering orifice 53. Clearly, a single screen or more than two screens may be employed under conditions permitting or requiring such screening.

It is even more likely that extraneous solids may be drawn into the pilot light nozzle 24 through the holes Si in the shield 50 than that such solids may be carried in the fiuid fuel. Accordingly, a screen is provided covering each hole in the shield. One form of screen for this purpose is indicated in Fig. 3, wherein a circular screen 51, of different diameters along its axial extent, is firmly held between an annular shoulder 58 in the shield 50 and the outer surface ofv the pilot light nozzle 24. The edge of the screen 51 adjacent the end of the nipple 52 may either rest uponthe annular face of the nipple between the external and internal threads or may be otherwise attached at this point. Thus, air passing through the holes in the shield 5| will be properly screened before entering the air passages 28 in the pilot light nozzle 24.

The examples here described and illustrated are presented merely to indicate how the invention may be applied. Other forms of the invention differing in detail but not in principle from that here described will, of course, suggest themselves to those skilled in this art.

We claim:

1. In a blowpipe, a pilot light nozzle. having therein a substantially axial fuel gas passage and an air inlet passage at an angle to the fuel gas passage with an external opening in the surface of said nozzle, means for supp ying said passage with a minimumquantity of gas, means for supplying said passage at will with an increased quantity of gas, and a shield for said nozzle, said shield having a hole therein adjacent the external opening of the air inlet passage in said nozzle, the hole in said shield serving to permit additional air easily to reach said air inlet passage upon increase of gas supply.

-2. In a blowpipe, a pilot light nozzle having therein a substantially axial constricted fuel gas passage and an air inlet passage at an angle to the fuel gas passage with an external opening in the surface of said nozzle, a fuel gas supply con P duit connected with the fuel gas passage in said nozzle, means for supplying saidconduit with a minimum quantity of gas, means for supplying said conduit at will with an increased quantity of gas, and a conicalscreen having its apex pointing inthe direction of fuel gas travel disposed in said conduit and serving to protect the constricted fuel gas passage in said nozzle from becoming clogged.

3. In a blowpipe,. a pilot light nozzle having therein a substantially axial constricted fuel gas passage and an air inlet passage at an angle to the fuel gas passage with an external opening in the surface of said nozzle, a fuel gas supply conduit connected with the fuel gas passage, means for supplying said conduit with a minimum quantity of gas, means for supplying said conduit at will with an increased quantity of gas, and a pair of conical screens having their .apices pointing in conduit, said screens having different conical altitudes. said screens serving to protect the constricted fuel gas passage in said nozzle from be- 7 passage with an external opening in the surface of said nozzle, a nipple having a fuel metering orifice therein connected to said nozzle and opening into the fuel passage therein, and a conical screen having its apex pointing in the direction of fuel travel disposed in said nipple on the pressure side of the fuel metering orifice therein to prevent clogging of the orifice by particles in the fuel gas. I

5. In a blowpipe, a pilot light nozzle having therein a substantially axial fuel gas passage and an air inlet passage at an angle to the fuel passage with an external opening in the surface of said nozzle, means for supplying said passage with a minimum quantity of gas, means for supplying said passage at will with an increased quantity of gas, a shield for said nozzle, said shield having a hole therein adjacent the external opening of the air passage'in said nozzle, and a screen covering the hole in said shield, the hole in said shield serving to permit additional air easily to reach said air inlet passage upon increase of gas supply. u

6. In a fluid fuel burner, a pilot light nozzle having therein a substantially axial fuel passage and an air inlet passage at an angle to the fuel passage with an external opening in the surface of said nozzle, a fuel conduit connected with the fuel passage in said nozzle, and a conical screen having its apex pointing in the direction of fuel travel disposed in said conduit, in combination with a shield for said nozzle, said shield having .a hole therein opposite the external opening of the air inlet passage in said nozzle, and a screen passage with an external opening in the surface of said nozzle, a nipple having a fuel metering orifice therein connected to said nozzle and opening into the fuel passage therein, and a conical screen having its apex pointing in the direction of fuel travel disposed in said nipple, in combination with a shield for said nozzle said shield having a hole therein opposite the external opening of the air passage in said nozzle, and a screen covering the hole in said shield.

8. In a blowpipe, a bracket attached to the forward part'of the blowpipe, a pilot light nozzle carried by said bracket, said nozzle having therein a substantially axial fuel passage and an air inlet passage at an angle to the fuel passage with an external opening in the surface of said nozzle, a shield for said nozzle independently carried by said bracket, said shield having a hole therein adjacent the external opening of the air inlet passage in said nozzle, a bore in said bracket communicating with the fuel passage in said nozzle, and a fuel conduit communicating. with the bore in said bracket.

9. In a blowpipe, a bracket attached to the forward part of the blowpipe, a pilot light nozzle carried by said bracket, said nozzle having therein a substantially axial fuel passage and an air inlet passage at an angle to the fuel passage with an external opening in the surface of said nozzle, a shield for said nozzle independently carried by said bracket, said shield having a hole therein opposite the external opening of the air passage in said nozzle, said bracket having a bore therein communicating with the fuel passage in said nozzle, a fuel conduit communicating with the bore in said bracket, and a screen covering the hole in said shield.

10. In a blowpipe, a bracket attached to the forward part of the blowpipe, a nipple attached to said bracket at one end, a pilot light nozzle attached to said nipple at the other end, said nozzle having therein a substantially axial fuel passage and an air inlet passage'at an angle to the fuel passage with an external opening in the surface of said nozzle. a shield for said nozzle independently carried by said nipple, said shield having a hole therein opposite the external opening of the air inlet passage in said nozzle, a screen covering the hole in said shield and a conical screen having its apex pointing in the direction 2 of fuel travel disposed in said nipple.

11. In a blowpipe, a bracket attached to the forward part of the blowpipe, said bracket having a bore therethrough; a fuel conduit connected to said bracket at one end of the bore there- 25 through; an external thread on said bracket substantially concentric with the other end of the bore; a nipple having a bore internally threaded at one end adapted to screw upon the external thread on said bracket, said nipple also having 30 a metering orifice therein in continuation of the bore and being internally and externally threaded at its other end; a pilot light nozzle externally threaded at one end for screwing into said nipple, said nozzle having therein a substantially 35 axial fuel passage and an air inlet passage at an angle to the fuel passage with an external opening in the surface of said nozzle; and a shield for said nozzle having an internal thread therein screwed upon the external thread of said nipple,

40 said shield having a hole therein opposite the external opening of the air inlet passage in said nozzle.

12. In a blowpipe, a bracket attached to the forward part of the blowpipe, said bracket hav- 5 ing a bore therethrough; a fuel conduit connected to said bracket at one end of the bore therethrough; an external thread on said bracket substantially concentric with the other end of the bore; a nipple having a bore internally threaded 50 at one end adapted to screw upon the external thread on said bracket, said nipple also having a metering orifice therein in continuation of the bore, and being internally and externally threaded at its other end; a pilot light nozzle exter- 55 nally threaded at one end for screwing into said nipple, said nozzle having therein a substantially axial fuel passage and an air inlet passage at an angle to the fuel passage with an external opening in the surface of said nozzle; and a. shield 0 for said nozzle having an internal thread therein screwed upon the external thread of said nipple,

said shield having a hole therein opposite theexternal opening of the air passage in said nozzle; in combination with a conical screen having 05 its apex pointing in the direction of fuel travel disposed in the bore of said nipple.

13. In a blowpipe, a bracket attached to the forward part of the blowpipe, said bracket having a,bore therethrough; a fuel conduit connected 7 to said bracket at one end of the bore therethrough; an external thread on said bracket substantially concentric with the other end of the bore; a nipple having a bore internally threaded at one end adapted to screw upon the external 75 thread on said bracket, said nipple also having a metering orifice therein in continuation of the bore and being internally and externally threaded at its other end; a pilot light nozzle externally threaded at one end for screwing into said nipple, said nozzle having therein a substantially 5 axial fuel passage and an air inlet passage at an angle to the fuel passage with an external opening in the surface of said nozzle; and a shield for said nozzle having an internal, thread therein screwed upon the external thread of said nipple, 10 said shield having a hole therein opposite the external opening of the air passage in said nozzle;

in combination with apair of conical screens having their apices pointing in the direction of fuel travel disposed in the bore of said nipple, 5 said screens having diiferent conical altitudes.

14. In a blowpipe, a bracket attached to the forward part of the blowpipe, said bracket having abore therethrough; a fuel conduit connected to said bracket at one end of the bore therethrough; an external thread on said bracket substantially concentric with the other end of the bore; a nipple having a bore internally threaded at one end adapted to screw upon the external thread on said bracket, said nipple also having a metering orifice therein in continuation of the bore and being internally and externally threaded at its other end; a pilot light nozzle externally threaded at one end for screwing into said nipple, said nozzle having therein a substantially axial fuel passage and an air inlet passage at an angle to the fuel passage with an external opening in the surface of said nozzle; and a shield for said nozzle having an internal thread therein screwed upon the external thread of said nipple, said shield having a hole therein opposite the external opening of the air inlet passage in said nozzle; in combination with a conical screen having its apex pointing in the direction of fuel travel disposed in the bore of said nipple; and a screen covering the-hole in said shield.

15. In a blowpipe, a bracket attached to the forward part of the blowpipe, said bracket having a bore therethrough; a fuel conduit connected to said bracket at one end of the bore therethrough; an external thread on said bracket substantially concentric with the other end of the bore; a nipple having a bore internally threaded at one end adapted to screw upon the external thread on said bracket, said nipple also having a metering orifice therein in continuation of the bore and being internally and externally threaded at its other end; a pilot light nozzle externally threaded at one end for screwing into said nipple, said nozzle having therein a substantially axial fuel passage and an air inlet passage at an angle to the fuel passage with an external opening in the surface of said nozzle; and a shield for said nozzle having an internal thread therein screwed upon the external thread of said nipple, said shield 00 having a hole therein opposite the external opening of the air inlet passage in said nozzle; in combination with. a pair of conical screens having their apices pointing in the direction of fuel travel disposed in the bore of said nipple, said 5 screens having different conical altitudes; and a screen covering the hole in said shield, substantially as described.

16. A blowpipe comprising a handle; a tip; and a stem joining said handle and said tip, said 7 stem comprising conduits for fuel gas and combustion supporting gas; a bracket having a bore therethrough carried by said stem; and a fuel conduit in said stem connected to one end of the bore in said bracket; in combination with a pilot 7 light nozzle connected to said bracket, said nozzle said bracket; in combination with a pilot light having therein a substantially axial fuel passage nozzle connected to said bracket. said nozzle havin continuation of the bore in said bracket and ing therein a substantially axial fuel passage in an air inlet passage at an angle to the fuel pascontinuation of the bore in said bracket and an 5 sage with an external opening in the surface of air inlet passage at an angle to the fuel passage 5 said nozzle; and a conical screen having its apex with an external opening in the surface of said pointing in the direction of fuel travel screening nozzle; a conical screen having its apex pointing the fuel going to the fuel passage. in the direction of fuel travel screening the fuel 17. A blowpipe comprising a handle; a tip; and going to the fuel passage; a shield for said nozzle,

10 astem joining said handle and said tip. said stem said shield having a hole therein opposite the 10 comprising conduits for fuel gas and combustion external opening of the air passage in, said nozzle; supporting gas; a bracket having a bore thereand a screen covering the hole in said shield. through carried by said stem; and a fuel conduit HERBERT W. COWIN. in said stem connected to one end of the bore in WILGO'I' J. JACOBSSON.

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