US2518895A

US2518895A - Hand blowpipe

Info

Publication number: US2518895A
Application number: US702440A
Authority: US
Inventors: Wilgot J Jacobsson; Samuel R Oldham
Original assignee: Linde Air Products Co
Current assignee: Linde Air Products Co
Priority date: 1946-10-10
Filing date: 1946-10-10
Publication date: 1950-08-15
Anticipated expiration: 1967-08-15

Description

-Aug. 15, 1-950 w. J. JACOBSSON ET AL 2,518,395

' HAND IBLOWPIPE.

Filed Oct. 10, 1946 2 Sheets-Sheet 1 IINVENTORS W/LGOT J. JACOBSSON s wua R. OLDHAM ATTONEY Patented Aug. 1950 4 HAND BLOWPIPE I Wilgot J. Jacobsson, Plainfield, and Samuel R. Oldham, East Orange, N J., assignors to The Iinde Air Products 00., a corporation of Ohio Application October 10, 1946, Serial No. 702,440

1 This invention relates to relatively small, lightweight, medium-pressure. manual type oxy-fuel gas blowpipes which are providedwith a plurality of interchangeable heads of different sizes, so that the same handle can be used "for a wide variety of flame utilizing operations including welding.

In such blowpipes one problem, especially in the case of oxy-acetylene blowpipes, is overheating of the handle due to heat transmitted from the tip. Another problem is holding and selectively'adjusting the gas valves of the blowpipes with one hand. Still another problem involves the time and efiort of quickly changing heads readily and adjusting a selected head rotationally on the handle while work is in progress. -Such problems are very diiflcult to solve in aircraft type hand blowpipes. for example, because thelatter are very small in size compared to conventional blowpipes. g

The main objects of the invention are to provide a blowpipe of this type which is relatively cool to hold inuse, and in which the oxygen and fuel gas valves maybeeasily and accurately adjusted with a finger of the hand holding the blowpipe. Another object is to provide animproved slip-fit. lock connection between the handleand head. I

These objects are attained by a blowpipe having a handle provided with gas inlets at the rear and novel adjustable gas valves at the front thereof. The valves are on a common centerline extending transversely of the handle, and are located very close together on the front of the handle so that either valve can be opened or closed by aflnger of the operator's hand which grips the handle in a normal andnatural position. This permits regulation of gas flows by one hand while welding for example. A novel push-in type self-sealing joint connects the head to the handle without making use of screw threads of any type. Thus, substantially instantaneous attachment or detachment of the head with the handle is possible. Novel means are also provided for securely locking the head axially in working position on the handle, while the head may be angularly adjusted on the handle, as desired. An efllcient heat dam and hand grip effectively retard the flow of heat from the head to the hand holding the blowpipe.

Referring to the drawings:

, Fig. 1 is a perspective view of'a handwelding oxy-acetylene blowpipe' exemplifying the invention;

'12 Claims. (01. 158-274) mechanism:

Fig. 2 is anexploded view of Fig. 3 is an enlarged fragmentary view mainly in longitudinal section of such blowpipe;

Fig.4 is an enlarged cross-sectionalyiew taken on line 4-4'of Fig. 3;

Fig. 5, is ajview similar to Fig. 3 of a headhandle modification; and

Fig. 6 is a fragmentary view in side elevation of a modifiedhandle.

As shown in Fig. 1 of the drawing, the hand ,blowpipe A comprises a handle B and a head C;

The handle B is provided with a fuel gas inlet connection l0 and an oxygen inletconnection l2. These connections are adapted to couple the gas inlets in-the handle to suitable fuel gas and oxygen supply hoses F and 0, respectively. The handle B ha longitudinal oxygen and fuel gas passages I4 and i6 communicating at the rear of the handle with the respective gas supply hoses F and O, and in the front of the handle with gas valve wells or recesses l5 and I1, Fig. 3, The handle is covered by a grip l8 of soft material, such as molded rubber, which may be slip-fit over the handle or molded-in-place on the handle.

, Suitable plastic material may be used instead of wrapped type-cord or tape. Located in the front rubber for the grip which may also be of the of the handle B are

novel gas valves

22 and 24.

The head C includes a stem 26 provided with an oxy-fuel gas mixer 28 and a nozzle or tip 30. The tip 30 is threaded at 32 into the stem 26; while the gas mixer 28 is press-fitted into the stem at 34. The head C is readily interchangeable in the handle B with other heads adapted to produce larger or smaller oxy-fuel gas flames, by virtue of a novel joint which is described in detail below.

In operation, Fig, 3, oxygen is fed into the blowpipe A through the oxygen as passage 14, in the handle B-,- which leads to the oxygen valve 22. In a similar manner fuel gas such as acetylene enters the fuel gas passage I6 to the valve 24. When valve stem 36 is moved off its seat 38 in the handle B acetylene flows past the stem 36 and-into gas passage 40 from which-it flows into axial metering orifice 42 of the mixer 28 which is pressed into the stem 26, and out through gas. passage 5! throughalongitudinally-extending annular passage 52 between the mixer 28 .and stem 26. This annular passage 62 is of such he stemllockinglength and width as to give good flashback resistance and proportioned to suit the maximum gas consumption of the blowpipe. The acetylene metering orifice 42 in mixer 28 is proportioned to accommodate the capacity of the head C at predetermined acetylene pressures. Oxygen passes inwardly through radial holes 54 in the mixer 28 at right angles to its longitudinal axis, and, mixing with the acetylene flowing through the central passage 44, passes into the stem passage 46, and out through the tip 38.

The valves are located in the wells I5, I! in diametrically opposite sides of the front of the handle and are much shorter than needle valves of the usual type and are in-line valves. Only a small valve lift is required to produce full flow. Although both valve stems are threaded to the handle B, each has a transverse hole 56 drilled through the threaded section, into which is pressed a length of plastic rod to form a friction plug 58 which is of length equal to the outside diameter of the thread. A thread is formed on this plastic material which completely fills the thread grooves by screwing the valve stem into the threaded section of the handle. Thus, backlash is eliminated and suflicient friction is introduced to maintain the stem in fixed position at any desired adjustment of the valve.

A plastic material in the form of a solid ring 68, not split, and of round, square, or rectangular cross-section, surrounds the shank portion of each valve stem and is clamped down against flange 62 by a compression cup 64. The compression cup is provided with suitable sockets 66 to accommodate compression cup screws 68. A coil spring 18 is located beneath each screw head which can be tightened to increase the load on the packing ring 68 to obtain sealing or a desired increase in the amount of friction on the valve stem. If necessary or desirable, the screws 68 can be tightened so that the springs I8 go solid to obtain added loading.

A valve wheel 12, locatedin, and comprising at least a partial closure for the well I1, is secured over the end of. the valve stem 55, which is provided with two lateral flats, and held in place on the stem by a lock washer I4, and a screw I6 threaded into a suitable socket in the stem. The valve wheel I2 contains holes 18 each of which can be alined with a corresponding compression cup screw 88 by rotation of the valve wheel so that clearance for a screwdriver through the wheel-closure I2 is obtained for tightening the compression cup screws and thereby adjusting the packing load without dismantling the valve assembly. The handle is shaped so that an opening I1 is provided in the top of the handle for the projection of a segment of the periphery of each wheel "I2.

As shown in Fig. 6, in an alternative arrangement, the handle may be provided with arcuate flanges 19 adjacent the front and rear segments of wheels 12, in which case the upper and lower segments of the wheels are exposed for convenient manipulation, while the Wheels are protected by the flanges.

The valve wheel 12 is suitably corrugated on its circumference and is wide enough to minimize side thrust on the thread when the wheel is turned. Each valve can be manipulated by finger tip pressure, closing when turned in a forward direction and opening when turned toward the rear of the blowpipe. To prevent the upper thread of the valve stem from digging into the packing material, a small metal Washer 88 acting as a stop is placed under the packing ring 88.

The heads C are of the gasket-sealed, push-in type with round, square, or rectangular ring gaskets. The sealing ring 88, Fig. 3, for the mixer, seals between the oxygen and fuel gas passages, while mixer sealing ring 88 seals to the atmosphere.

The tips 38 are of one-piece, swaged-and-bent pipe. To reduce heat conduction to the blowpipe handle, the mixer 26 is provided with an elongated annular area-restricting groove 94 which reduces the cross-section of the tube at this zone. Thus, heat engendered in the tip 38 can only flow into the handle B through the areas of the narrow surfaces which contact the portion 86 and through the mixer area contiguous with the portion 98 of the handle B. In effect, then, there is provided an efllcient heat dam which minimizes contact area between the mixer and handle in order to reduce heat transmission. The mixer is also preferably composed of material of low heat conductivity.

Even though the friction of the sealing rings '86, 88 is sufllcient in most cases to prevent the head C from blowing out of the handle if a flashback occurs, positive locking means is provided for securing the head C in place on the handle B. The lock comprises a rotatable collar I88 fitting over the front end portion 86 of the blowpipe handle B with one or more small movable members such as steel balls I82 located in mating holes I84 in such portion 96, engaging an annular shoulder I86 on the stem, and normally prevented from moving out of the locking position by the collar. When the latter is rotated, however, the movable members I82 are allowed to move into internal longitudinal grooves I83, Fig. 4, in the collar so that the interference between them and stem 28 is eliminated and the head C can be removed axially from the handle B.

A coiled torque spring H8 is located in the rear end of the collar I88, one end being inserted at H2 in a hole in the collar and the other at H4 in a hole in the body of the handle B. The spring II8 functions to always return the collar I88 to a locking position. To prevent removal of the collar I88, the latter is held in longitudinal place by a split expanding spring ring IIB which engages mating grooves in the handle portion 98 and collar I88, so that once assembled the collar cannot be removed from the handle. The look also functions as a guard against improper insertion of the head C, since the collar I88 must be turned to the head unlocking position before the head C can be properly inserted in the socket portion 96.

Referring to Fig. 5, the handle B of the modified blowpipe A is generally cylindrical, and the oxygen and fuel gas passages I4 and I6 are similar to those of Figs. 1-3. Oxygen is fed into the blowpipe through oxygengas passage I4, in the handle, which leads to the oxygen valve 22. In a similar manner fuel gas such as acetylene enters through the fuel gas gas passage I6 to the valve 24. When the valve stem 36 is moved off its seat 38 fuel gas flows into gas passage 48 from where it flows into a mixer nozzle 25 which is press-fit into a mixer tube 26', and out through a throat section 21, which is held in place in the mixer tube 26' by the nozzle 25, then through mixer tube 26' and the welding tip 38 which is screwed into the mixer tube.

When valve stem 48 is moved off its seat 58, oxygen flows into gas passage 5| and through a plurality of longitudinal clearance slots 58 in the periphery of the front portion 51 of the mixer nozzle 25. These slots 53 are of such length and section as to give good flashback resistance and are proportioned to suit the maximum consumption of the particular size of the blowpipe. The fuel gas metering orifice 42' in nozzle 25 is proportioned to accommodate the capacity of individual heads at predetermined fuel gas pressures. Oxygen gas then passes through a slot 59 in the nose of the mixer nozzle at right angles to its longitudinal axis, and, mixing with the fuel gas flowing through the center of the nozzle, passes into the throat section 21 which is held in place by nozzle 25, and out through mixer tube 26' and the welding tip 30.

The plastic ring 60 of the valve is clamped down against the handle body by a compression cup lW'consisting of a solid mass with suitable drillings B6 to accommodatethe compression cup screws 68.

- In case the body B is composed of a soft material such as aluminum, the body thread for the stem is made in a separate piece 85 and inserted in the valve cavity 81 with a sealing gasket 89 underneath. This improves the wear qualities and makes provision for a replaceable thread unit. If the body is of a harder material, this thread section may be introduced in the material itself, as in Fig. 3, thus simplifying the construction and eliminating the gasket 89.

The sealing ring 86' for the mixer nozzle seals between the oxygen and fuel gas, while mixer tube sealing ring 88' seals the gases to the atmosphere. When the body B is of aluminum a wear-resistant sleeve 90 is inserted into the front body cavity 92 to prevent collapse of the soft material.

To reduce heat conduction to the blowpipe handle B, the mixer tube 26' is provided with two contact area-restricting grooves 95 and 81 which reduce the cross-section of the tube at these zones. Thus, heat engendered in the tip can only flow into the handle through the area of the three narrow annular fins 99 which contact the sleeve 92, and through the mixer tube area IOI contiguous with the front portion of the sleeve. In effect, then, there is provided an efficient heat dam" which reduces contact area between the mixer tube and handle and prevents heat transmission to the latter.

What is claimed is:

l'. A hand blowpipe having a handle provided with a laterally opening gas valve well, a needle valve having a short stem threaded to the handle, -and a finger wheel connected to said stem, the

axis of rotation of said wheel and stem coinciding with that of said well, and the external diameter of said wheel being only slightly smaller than the internal diameter of saidwell and providing a lateral closure for-such well, the handle having an opening through which a segment of said finger wheel projects for manual operation, the valve and wheel thus being substantially protected from damage and inadvertent operation.

2. A hand blowpipe haying a handle provided with a socket in the front endthereof, a head comprising an oxy-fuel gas mixef'and a tip for the blowpipe, the gas inlet portion of said head being disposed within such socket, and means including a plurality of plastic rings connecting and hermetically sealing the handle and head within said socket for telescopic insertion and removal thereof, said rings frictionally engaging tubular walls of said socket so as to hold portion within said socket.

3. A hand blowpipe having a handle provided with a socket in the front end thereof, a push-in head cooperatively associated with such socket, and locking means on the handle for releasably securing the head to the handle, comprising an annular shoulder on the head, at least one radially movable detent in the handle adapted to engage said shoulder when the head is in place in the socket, a collar rotatably mounted on the front portion of the handle and having an internal cam-surface cooperating with said detent for locking the latter in engagement with such shoulder when the collar is turned in one direction, and a coiled spring connected between said collar and the handle and urging the collar to turn in such direction, but permitting the collar to be turned in the opposite direction when it is desired to remove the head from the handle.

4. A hand blowpipe having a handle provided with a rotatably adjustable push-in head, and means for axially locking the head on the handle comprising a collar rotatably associated with such handle, and spring means resiliently urgin said collar to turn towards head-locking position on the handle, so that the head is angularly adjustable with respect to the handle.

5. An oxy-fuel gas hand blowpipe having a handle containing diametricallyopposed laterally opening valve recesses near the front thereof, valves reversely threaded in such recesses for opening movement when rotated about a common axis in the same direction, and valve wheels connected to said stems so that the wheels are close to directly opposite sides of the handle and may be adjusted as desired with the thumb of the hand gripping the handle to open or close the selected valve without reversal of direction of rotation thereof due to the opposed location of the wheels.

6. A blowpipe comprising a longitudinal handle member having a laterally opening well provided with an inner portion of smaller diameter than the outer portion of the well, such inner portion having an annular flange projecting into such outer portion, the bottom of such inner portion having a central gas inlet and a lateral gas outlet, a valve having a stem threaded to said member in the inner portion of said well, said stem having a valve seat cooperating with said gas inlet to control the flow of gas to the outlet when the valve stem is rotated, said stem having a transverse hole containing a friction plug composed of plastic material the length of which is such that the opposite ends of the plug are also self-threaded in such inner portion of the well, eliminating backlash and providing suflicient friction to maintain the stem in adjusted position, said stem having a shank of reduced diameter, a gas tight packin surrounding said shank and engaging said annular flange, and a hollow finger wheel secured to the outer end of said shank, said wheel having a maximum diameter slightly smaller than that of such outer portion of the well, the wheel being protectively located within in such socket, of combined gas sealing and retaining means disposed between said members within such socket comprising a pair of axially spaced rings composed of resilient plastic material disposed in suitable annular grooves in one of said members and adapted to engage and be compressed by the other member when such male portion is inserted in such socket, forming gastight seals and at the same time frictionally retaining such male portion in adjusted place in such socket, said members having an annular gas distributing passage located between said rings, one of said members having a gas inlet .passage leading to said annular gas distributing passage, and the other member having a gas outlet passage leading from said annular gas distributing passage.

8. In a gas torch, as defined by claim 7, means retarding the flow of heat from the head to the handle, comprising an axially elongated annular space in such socket between said members which is bounded by relatively narrow annular metalto-metal contacts between said members, said space being axially spaced from said gas distributin chamber and located on one side of said sealing means, said contacts acting to positively prevent the head from tilting in the handle but permitting the head to be axially and circumferentially positioned with respect to the handie.

9. In a gas torch, as defined by claim 8, means latching the head axially in place with respect to the handle, comprising a collar carried by said handle, and means on the inside of said collar engaging an annular part of the head so that the head can be turned with respect to the handle when the head is latched on the handle.

10. A hand blowpipe havin a handle provided with longitudinal oxygen and fuel gas passages for conducting oxygen and fuel gas from inlets at the rear endof the handle to oxygen and fuel gas outlets in the front end thereof, said handle having axially alined laterally opening oxygen and fuel gas valve wells in diametrically opposite sides near the front end of the handle, and oxygen and fuel gas valves disposed within such wells for controlling the flow of oxygen and fuel gas through such passages, said valves comprising finger wheels located in and providing lateral closures for the wells in the handle, said wells having side openings therein exposing segments of the wheels for convenient selective operation by a digit of the operator's hand gripping the handle, while the wheels and valves are substantially protected from damage and inadvertent operation.

11. A hand blowpipe having a handle provided with a longitudinal gas passage, and a laterally opening well near the front end of the handle, and a valve disposed in such well for controlling the flow of gas through the passage, said valve comprising a rotatable finger wheel located with in and providing a lateral closure for the well in the handle, said well having a side opening exposing a segment of the periphery of the wheel for convenient operation by the thumb of the operator's hand gripping the handle, while the valve and wheel are substantially protected from damage and inadvertent operation.

12. An oxy-fuel gas hand blowpipe as defined by claim 5, in which said handle has arcuate flanges concentric with said recesses adjacent segments of the valve wheels, which flanges protect the wheels from damage and inadvertent operation.

WILGOT J. JACOBSSON. SAMUEL R. OLDHAM.

REFERENCES CITED I The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,078,578 Gehring et al. Nov. 11, 1913 1,151,496 Pettis Aug. 24, 1915 1,230,204 Nash June 19, 1917 1,276,214 Harris Aug. 20, 1918 1,304,198 Nyquist May 20, 1919 1,430,026 Pasch Sept. 26, 1922 1,460,654 Huston July 3, 1923 1,481,535 Burdett June 22, 1924 1,701,377 Langley Feb. 5, 1929 1,724,371 Roth Aug. 13, 1929 1,793,052 Buttner Feb. 17, 1931 1,865,905 Hammon July 5, 1932 1,989,649 Bucknam Jan. 29, 1935 2,070,396 Evleth Feb. 9, 1937 2,164,256 Peterson June 27, 1939 2,164,972 Wagner July 4, 1939 2,176,813 Hammon Oct. 17, 1939 2,291,199 Anderson July 28. 1942 2,348,774 Anthes May 16, 1944 2,356,048 Goddeau Aug. 15, 1944 2,376,265 Meredith May 15, 1945 FOREIGN PATENTS Number Country Date 352,485 Italy Sept. 15, 1937 834,356 France Nov. 18, 1938;