US1949780A

US1949780A - Blowpipe tip

Info

Publication number: US1949780A
Application number: US515525A
Authority: US
Inventors: Jr Lorn Campbell
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-02-13
Filing date: 1931-02-13
Publication date: 1934-03-06
Anticipated expiration: 1951-03-06

Description

March 6, 1934. CAMPBELL,v JR 1,949,780

BLOWPIPE TIP Filed Feb. 13. 1931 lll /fwfw Patented Mar. 6, 1934 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to the production of a tip for cutting blowpipes comprising inner and outer tip members, wherein the inner member is provided with a central bore for cutting oxygen extending therethrough and with a series of longitudinally extending slots which, when the outer member is applied to the inner member, are converted into passages for the preheating mixture of combustible gas and oxygen. Specifically, the inner tip member is provided in the tapered operating end thereof with a series of slots, the body of said tip member being annularly recessed between the series of slots whereby, on assembling the outer tip member upon the inner tip member, a series of upper channels for preheating mixture will be formed, the lower ends of these channels delivering the mixture into an annular chamber whence the preheating mixture is delivered through the lower series of passages to the operating end of the tip. In practice, the channels in each series have been equidistantly spaced.

For the purpose of assembling the inner and the outer members, it has been proposed to unite the same by inserting a key into the upper end of one of the upper passages, formed by assembling the outer tip member upon the inner tip member, thus converting this passage into a keyway, the outer surface of the key gripping the inner surface of the outer member. This results in blocking oif one of the passages, with a corresponding restriction in the volume of the preheating mixture that may be supplied to the operating end of the tip and also with a more or less unequal distribution of the preheating mixture supplied from such upper passages to the lower series of passages extending to the operating end of the tip. The equidistant spacing of the upper slots is necessary on account of the design of the tip, the inner tip member not being sufciently large to provide room between adjacent slots for a special keyway for the insertion of a key. Furthermore, the size of the tip is so restricted that it cannot be enlarged to widen the space between adjacent slots sufliciently to accommodate a keyway.

Further objections to the former mode of connecting the inner and outer tip member are; the expense of making the keys; the necessity for re- 'moving burrs therefrom so that the outer tip member may slide over the key which has been inserted into the slot selected therefor; and also the necessity for inserting the key in exactly the right position in such slot in the inner tip member.

It is the general purpose and object of my in- (Cl. 15S-27.4)

vention to so construct and connect inner and outer tip members of the character heretofore referred to as to enable all of the passages in the upper portion of the tip to conduct the preheating mixture; to eliminate the necessity for making and inserting keys; and generally to increase the capacity and efciency of tips of this character.

I secure the foregoing advantages by constructing the inner tip member and assembling the inner and outer tip members in the manner shown in the drawing hereof, wherein Fig. 1 represents a central vertical sectional view through the head of a blowpipe having a tip embodying my invention; Fig. 2 a side elevation of the inner tip member of such blowpipe; Fig. 3 a detail in section corresponding to the line 3-3 of Fig. 1; and Fig. 4 a detail in section corresponding to the line 4 4 of Fig. 2.

Describing by reference characters the various parts illustrated, 1 denotes the head of a blowpipe to which my tip is attached, the said head being provided with a neck 2 having in the upper portion thereof a branched passageway 3 communicating at its forward end with a chamber 4, the head also having upwardly inclined passageways 5 and 6. Communicating with the rear or receiving ends of the

passageways

3, 5 and 6 are the pipes '7, 8 and 9 which serve to conduct cutting oxygen, preheating oxygen, and combustible gas, respectively, to the said passageways. Thefupper end of the passageway 5 is shown as communicating with a chamber 10 formed by a bore extending downwardly and forwardly into said head and having threaded thereinto the body 1l of an injector, the said injector having a stem 12 extending through said chamber and being provided with an operating head 13, between which and a seat 14 on said head a packing ring l5 is inserted. The injector is provided with a central bore 16, the upper end of which communicates by lateral ports 17 with the chamber l0 and the lower end of which bore is adapted to discharge centrally into an inclined passageway 18 which in turn discharges into an annular chamber 19 provided in the lower portion of the blowpipe head above the outer tip member and surrounding the upper portion of the inner tip member. The passageway 6 discharges into a chamber 20 surrounding the lower end of the injector and communicating with the passageway 18.

Extending downwardly from the chamber 4 is a short passageway 2l which merges with an enlarged threaded bore 22 extending to the charnber 19.

The blowpipe head just described is one which is adapted to cooperate with a tip construction, which will now be described. 23 denotes generally an inner tip member having a cylindrical main body portion 24, with an upper threaded extension 25 adapted to engage the thread of the bore 22, the upper end of the tip member being reduced and having a convex seating portion 26 adapted to engage a beveled seat 27 below the lower end of the passage 21. Below the body portion 24, the inner tip member is provided with a downwardly tapered reduced portion 28, there being an annular shoulder 24@l provided between the top of such reduced portion and the-body portion 24, the lower end of the tip member being frusto-conical, as shown at 29, and there being an outwardly extending shoulder 30 between the upper `end of such frusto-conical portion and the reduced portion 28. f

The inner tip member is provided with a central bore 31 the upper end of which receives cutting oxygen from the chamber 4 and the passage 21, the lower end of the bore being reduced, -as shown at 31a. The body portion 24 is provided with a plurality of equidistantly spaced slots 32 extending radially inwardly from the outer surface thereof, the upper ends of the slots being spaced from the threaded portion 25. Five such slots are shown and, while the number of the slots may be varied, this number provides, when the outer tip member is assembled upon the inner tip member, passages of suflicient aggregate cross sectional area. to insure an eicient preheating operation without unnecessarily weakening the walls of ythe dovetailed ribs 33 which separate the said passages. The slots 32 extend through and below the shoulder 24, and the lower frustoconical end of the inner tip member is provided with a plurality of equidistantly spaced slots 34 extending the full length of such frusta-conical portion and, when converted into passages by mounting the outer member thereon, serving to deliver to the operating end of the tip a convergent series of jets of preheating gas.

Cooperating with the inner tip member 23 is an outer tip member, indicated generally at 35, the outer member having a cylindrical upper portion 36 adapted to fit snugly about the cylindrical body 24 of the inner member, thereby sealing the slots 32 and providing passages for the preheating mixture. The top of the inner tip member terminates below the upper ends of the slots 32 whereby the slots communicate with the annular chamber 19 provided in the head when the tip is assembled therein, as indicated in Fig. 1. The lower end of the outer tip member is frusto-conical, as shown at 37, and ts snugly about the frusto-conical lower end of the inner tip member, thereby sealing the outer ends of the slots 34 to form passages for the preheating mixture which is delivered through the upper passages into the annular chamber 38 provi-ded between the inner wall of the outer tip member and the reduced portion 28 of the inner tip member.

For the purpose of uniting the inner and outer tip members, I subject a portion of one of the ribs to a pressing action, exerted on opposite sides of the rib, whereby a key 39 is provided. the sai-d key projecting radially beyond the body of the rib and being substantially rectangular in section and narrower than the remaining portion of the rib. Because of the fact that this key projects radially outwardly beyond the rib 33, the outer member is provided with a slot 40 constituting a keyway and extending downwardly from the upper end of the outer member a distance sulhcient to accommodate the key during the operation of pressing the outer member upon the inner member.

By constructing and assembling the tip members in the manner described, I am enabled to obtain an extra passage for the preheating mixture in the upper portion of the tip. This, for the same size of tip, enables me to increase by 20% the aggregate cross sectional areas of the passages for gas, which results in a correspond- -ing decrease in the velocity of the gas supplied through such passages. These passages conduct the gas in contact with the heated shell of the outerl tip member, thus not only expanding the gas, but raising the temperature thereof so as to secure better combustion of the preheating mixture. `It is important to have as much heated area as possible for the mixture flowing through the passages 32 and to deliver the mixture through such passage at as slow velocity as possible. This result is secured by the manner of constructing and assembling the inner and outer tip members. v

Furthermore, because of the fact that theinner tip member is made of ductile material, such as bronze, when a `portion of one of the ribs 33 is subjected to pressure to form the key 39, this results in compacting the molecular structure -of such key and increasing the density thereof, whereby it is enabled the better to perform its function.

It will be noted that the lower end of the inner tip member is shown as terminating above the lower end of the outer tip member, whereby a chamber 41 is provided below the lower end of the inner tip member. This chamber is parits lio

ticularly useful in enabling the blowpipe to be operated without danger of blowing out the flame through the pressure of the oxygen delivered through the bore 312.

Having thus described my invention, what I claim is:

1. A blowpipe tip comprising in combination an outer member having a cylindrical upper body portion and a lower frusto-conical end portion, an inner member having its upper end projecting beyond the upper end of the outer member and provided with means for attachment to a blowpipe head and also provided with a central bore for cutting oxygen and having an upper cylindrical portion adapted to be received within the cylindrical portion of the outer member and a lower downwardly tapered reduced end portion adapted to be received within the frustoconical portion of the outer tip member, the cylindrical portion of the inner member fitting closely within the cylindrical portion of the outer member and extending substantially the full length of the cylindrical portion of said outer member, the cylindrical portion of the inner member being provided with slots extending inwardly from the exterior thereof and forming passages for a preheating mixture with the outer member, the upper ends of the slots extending as far as the upper end of the outer member and the lower ends of the said slots extending to substantially the lower end of the cylindrical portion of the outer member, the slots being spaced equidistantly and being separated by ribs, one of said ribs having an integral longitudinal key extending radially beyond the outer surfaces of the other ribs, the outer member being provided with a keyway receiving the said key, the said i... fi)

tip having passages at the delivery end thereof for preheating mixture supplied through the first mentioned passages.

2. A blowpipe tip comprising in combination an outer member having a cylindrical upper body portion and a lower frusto-conical end portion, an inner member having its upper end projecting beyond the upper end of the outer member and provided with means for attachment to a blowpipe head and also provided with a central bore for cutting oxygen and having an upper cylindrical portion adapted to be received within the cylindrical portion of the outer member and a lower downwardly tapered reduced end portion adapted to be received within the frusto-conical portion of the outer tip member, the cylindrical portion of the inner member fitting closely within the cylindrical portion of the outer member and extending substantially the full length of the cylindrical portion of said outer member, the

cylindrical portion of the inner member being provided with slots extending inwardly from the exterior thereof and forming passages for a preheating mixture with the outer member, the upper ends of the slots extending as far as the upper end of the outer member and the lower ends of the said slots extending to substantially the lower end of the cylindrical portion of the outer member, the slots being spaced equidistantly and being separated by ribs, one of said ribs having an integral longitudinal key extending radially beyond the outer surfaces of the other ribs and being of less width than the width of the outer surface from which it extends, the outer member being provided with a keyway receiving the said key, the said tip having passages at the delivery end thereof for preheating mixture supplied through the rst mentioned passages.

LORN CANIPBELL, JR.