US3403964A - Oxyacetylene blowpipes - Google Patents

Description

Oct. 1, 1968 Filed June 8, 1967 R. D. DELBOURGO ET AL OXYACETYLENE BLOWPIPES 5 Sheets-Sheet 5 /NVENTOES RALPH DELBOURQO fiqwnolva Foumr/se PA LAP/77E Ji-AN MENE'RET 1.01/45 M/NJ'OLLE 7' TORNE Y6 United States Patent 6 Claims. 61. 431-256) ABSTRACT OF THE DISCLOSURE A blowpipe assembly for oxyacetylene devices having at least three adjustable feed means connected to a combustible gas pipe, a combustion supporting gas pipe and a motivating gas pipe. Each feed means being controlled by a needle which coacts with an adjustable orifice through which the gases must pass, and electrical ignition means for the combustible mixture formed by the combustion and supporting gases. The needles are all connected to a common yoke which is displaced by a driving device actuated by the motivating gas and which cooperates with a contactor member controlling the electrical ignition rneans.

The present invention relates to oxyacetylene blowpipes.

In oxyacetylene blowpipes known hitherto, the gas feeding device produces carbon deposits both during ignition and extinction of the flame.

The improvement to oxyacetylene blowpipes according to the present invention consists in providing a feed of combustible and combustion supporting gas in definite and adjustable proportions, and ignition of the combustion mixture by an electric spark within the feed nozzle in synchronism with the progressive arrival of the mixture.

Such a blowpipe improved according to the invention enables instantaneous ignition of an intense high temperature flame to take place from a preformed mixtures, without production of carbon deposits.

Carbon deposits are thus avoided both during ignition and extinction of the flame so that a progressive growth or diminution of the required flame can be obtained from a mixture whose concentration is strictly controlled and stable.

The device of the invention moreover enables rapid performance of the operations of variable opening and closing of the control valves to be effected, a complete independance of the regulation of the flow of the combustible and combustion supporting fluids to be achieved, and a controlled interval between the Opening of the valves controlling the discharge of the respective gases. These adjustments can be effected without dismantling the apparatus. These characteristics enable instantaneous and repeatable ignition of a preformed mixture to be obtained.

According to the present invention, the admission control needles for the gas are rigidly secured to a yoke operable by an actuating member and which cooperates with a contactor element controlling the electric ignition means of the combustible mixture, adjustment means ensuring the positioning of the needles with respect to the yoke and control of the gas admission apertures.

Other characteristics and advantages of the invention will appear from the following description of one embodiment of the invention, given by way of example, with reference to the accompanying drawings in which:

3,403,964 Patented Oct. 1, 1968 r'lca FIG. 1 is a schematic view of a feeding and ignition device for an oxyacetylene blowpipe of the invention,

P16. 2 is a plan view of one embodiment of a feed and ignition device for a blowpipe, I

3 is a sectional view along line III-III of FIG. 4 is a sectional-view alon lin I FIG. 2 g e V IV of FIG. 5 is a sectional view FIG. 2 along line V .V of

FIG. 6 is an elevational view showing in detail the contacting device and its control member, and

FIG. 7 is a sectional view of an embodiment of a seal used in the device of the invention.

The feed and ignition device shown schematically in FIG. 1, comprises a pneumatic driving device 1 constituted by a piston 2 movable in a cylinder 3 and subjected on its two faces to the action of a fluid introduced into the cylinder by ducts 4 and 5 connected to a five-way valve 6 enabling the ducts 4 and 5 to be connected alternately to a source of compressed fluid by a further duct 7 and to an opening 8 to the atmosphere. In this way, one of the faces of the piston is subjected to the pressure of the fluid when the other face communicates with the atmosphere. The piston 2 is connected by a hollow rod 9 to a yoke 10 having threaded holes 11, 12, 13 in which are engaged the threaded upper portions 14, 15, 16 of needles 17, 18, 19, which are thus connected for axial movement with the yoke 10. The needles 17 and 19 are slidingly mounted respectively in guiding sleeves 20, 21, whose lower parts 22, 23, forming throttle chambers, are rotatably mounted in cylindrical housings 24, 25, formed in a valve body 26. The needle 18 is slidingly mounted within the hollow rod 9 of the piston and in an extension 27 of the cylinder 3 which is engaged in a housing 28 of the valve body 26.

The needle 17, by means of its extremity 29 which forms a point, controls the output of acetylene which circulates through the admission duct 30a and the exit duct 30b, the needle 18 by its pointed extremity 31 controlling the output of operating or projecting air circulating in the admission duct 32a and exit duct 32b, and the needle 19, by its pointed extremity 33 controlling the oxygen circulating in the admission duct 34a and the exit duct 34b.

The guiding sleeves 20 and 21 have respectively at their lower portions 22, 23 which form throttle chambers, an orifice 35, 36, which ensures communication between the gas admission duct and exit duct. By rotating the sleeves 20, 21, through a predetermined angle, the size of the admission orifice, and thus the output of gas, can be varied. There is thus provided a first adjustment of the needles 17, 18, 19 in depth, by screwing the heads 11, 12, 13 on the yoke 10, by means of knurled knobs 37, 38, 39 and a second adjustment by means of the guide sleeves 20, 21 which are displaced by rotation to obtain a desired opening of the orifices of the admission ducts 30a and 34a.

These two adjustments enable the relative discharges of the constituents to be controlled, which latter are preserved when the three needles 17, 18 and 19 are simultaneously displaced under the action of the driving device 1.

The device shown in FIG. 1 is in the closed position of the ducts and the aforesaid adjustments have been made. The conduit 5 is then placed in communication with the source of compressed air and the duct 4 with the opening to the atmosphere, so that the piston is displaced in the direction indicated by the arrow A raising simultaneously the yoke 10 and the needles 17, 18, 19 which uncover the openings of the admission ducts 30a,

32a and 34a to admit combustible gas and combustion supporting gas into the blowpipe schematically shown at 30.

For a determined position of the needles 17, 18, 19 corresponding to the ignition of the blowpipe, the piston, which is controlled by the electro-valve 6, is stopped, and simultaneously the yoke 10 comes into Contact with a contacting element 40 which controls in known manner the electrical blowpipe ignition device 40a.

In order to extinguish the blowpipe flame, the feed of the ducts 4 and 5 is reversed so as to drive the piston in the reverse direction to that of the arrow A, together with the yoke and needles 17, 18, 19 which close the orifices of the admission ducts 30a, 32a and 34a. In FIGS. 2, 3, 4 and 5, there is shown an embodiment of the device of the invention in which will be found the principal elements described with reference to FIG. 1. The cylinder 3 is constituted by a body 41 which is closed at its upper end by a screw-cap 42, a sealed joint 43 being interposed between the cap 42 and the body 41, and a further seal 44 being interposed between the rod of the piston 9 and the opening in the cap 42 through which it passes.

The cylinder body 41 is fixed to the valve body 26 by screws 45.

The upper ends of the needles 17, 18, are held tightly in sleeves 46, 47 by means of set- screws 48, 49 the sleeves 46, 47 being externally threaded to receive nuts 50, 50a and 51, 51a which secure the sleeves 47, 46 and consequently needles 17, 19 in the yoke 10. By adjusting the sleeves and nuts, it is possible to vary the positions of the needles.

The needle 18, which is mounted in the hollow rod 9 of the piston, is fixed by a set screw 52 on a sleeve 53 which is itself screwed onto the threaded end 54 of the hollow rod 9, together with a lock nut 55. The yoke 10 is gripped between the sleeve 53 and the nut 55 in such a way as to move the needle 18 with respect to the yoke 10 and to the hollow rod 9.

To provide an angular adjustment of the guide sleeves 20, 2.1, the latter are provided with clamping plates 56, 57 having slots 58, 59 in which are engaged respectively screws 60, 61 fixed in the valve body 26 of the blowpipe.

On the lower parts 29, 31 and 33 of the pointed needles 17, 18, 19 are disposed seals 62, 62a separated by a spacer 63, which seals are disposed in housings 64 within the guiding sleeves 20, 21 and in the extension 27 of the cylinder 3. The upper seal 62 seals around the needle to avoid leaks to the exterior and the lower seal 62a constitutes the seating of the needle. The yoke 10 is laterally extended by a plate 65 on which is fixed by means of collars 70, 70a, a shaft 71 carrying a cam 72 the shaft 71 being guided at its lower portion by a bearing 73. The cam 72 cooperates with a roller 74 of a microswitch 66 of well known type.

When the cam 72 is displaced, it contacts the roller 74 which actuates the microswitch 66 so as to control the blowpipe ignition device.

FIG. 7 shows in section a preferred embodiment of a seal used in the device of the invention, such joint being constituted by a ring 67 of resilient material, preferably of rubber, which has on its contact faces for engagement with movable surfaces a layer 69 of a self-lubricating material such as Teflon, which provides a satisfactory sliding of the surfaces without sticking and which obviates the necessity for greasing so as to satisfy se curity standards.

Of course, the invention is not limited to the embodiment shown and described in detail, since various modifications can be made thereto without departing from its scope.

What is claimed is:

1. A blowpipe assembly comprising feed means respectively connected to at least one combustible gas pipe, at least one combustion supporting gas pipe and at least one motivating gas pipe, each feed means being controlled respectively by a needle the point of which is adapted to adjust an orifice through which passes one of the gases, and electrical ignition means for the combustible mixture formed by the combustion and supporting gases, characterized in that the needles controlling the flow of the gases are rigidly connected to a yoke which is displaceable by a driving device actuated by the motivating gas, and which cooperates with a contactor member controlling the electrical ignition means, regulating means controlling the positioning of the needles with respect to the yoke and also the sizes of the gas admission orifices.

2. A blowpipe assembly according to claim 1, characterized in that the driving device for the yoke comprises a piston having a rod rigid with the yoke, the piston being disposed in a cylinder and subjected on its faces to the action of the motivating gas whose admission to the cylinder is controlled by a valve.

3. A blowpipe assembly according to claim 1, characterized in that the regulating means are constituted by a threaded portion on each needle which is engaged in a corresponding threaded hole in the yoke, each needle being held in position in the yoke by means of a setscrew.

4. A blowpipe assembly according to claim 1, characterized in that the regulating means are constituted by a sleeve for each needle in which the needle is held in position by a set-screw, the sleeves being engaged in holes in the yoke and each having an external threaded portion on which are screwed on either side of the yoke lock-nuts which grip the latter.

5. A blowpipe assembly according to claim 1, characterized in that each needle is slidably mounted in a central bore in a throttle device mounted for rotation through a given angle in a body portion of the assembly, said throttle device being in communication at one side with an exhaust orifice and at the other side, by means of a lateral opening with a gas admission orifice.

6. A blowpipe assembly according to claim 1, characterized in that seals are provided in the form of rings of resilient material having on their faces a lining of self-lubricating material, which will contact the movable parts.

References Cited UNITED STATES PATENTS 6/1922 Godfrey l58-27.4 10/1966 Hach et al. 15827.4

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