US2437285A

US2437285A - Means for flaring tubing

Info

Publication number: US2437285A
Application number: US509931A
Authority: US
Inventors: James R Welshman
Original assignee: Grinnell Corp
Current assignee: Grinnell Corp
Priority date: 1943-11-11
Filing date: 1943-11-11
Publication date: 1948-03-09
Anticipated expiration: 1965-03-09

Description

March 9, 1948. l Y. J. R. wELsHMAN 2,437,285

' MEANSl FOR FLARING TUBlNG Filed Noir. 11, 1945 Patented Mar. 9, 1,948

MEANS FOR FLARING TUBING James R. Welshman, Cranston, R. I., assignor to Grinnell Corporation, Providence, R. I., a corporation of Delaware Application November 11, 1943, Serial No. 509,931

4 Claims.

This invention relates to improvements in a method of and means for flaring tubing. More especially it has to do with the formation of 'a tapering flared portion at the end of tubing so that the tubing may be engaged by a flared i'ltting,

My improved method and means are particularly adapted for llaring'tubing which has a weak longitudinal seam, or `similar longitudinal weakness, likely to produce a split in the tube wall when an attempt is made to vflare the tubing in the usual manner with the means customarily employed.Y

It is an object of my invention is provide a method of flaring `such tubing without rupture of the tube wall and to provide simple but highly effective apparatus iorpra'cticing the improved method.

The best mode in which I have contemplated applying th'e principles of my invention is described in the following .text and shown in the accompanying drawings, but the latter are to be deemed merely illustrative for it is intended that the patent shall cover by suitable expression in the claims whatever features of patentable novelty exist in `the invention disclosed.

in the accompanying drawings,

Figure 1 is an exploded 'View of the several parts of a preferred form of apparatus for flaring tubing in accordance with my improved method;

Figure 2 is a medial section showing the vparts oi' my improved apparatus and a piece o'ftubing in thel relative positions they occupy when the flaring operation is about to be performed;

Figure 3 is a section on line 3 3 of Figure 2;

Figures 4, I5 and 6, show the tubing and immediately adjacent parts of the apparatus in their relative positions at different stages of the daring operation;

Figure '7 shows the end of the tubing as it gen-k erally appears when removed from the apparatus; and

Figure 8 shows the nnished "flared end.

The essence of my improvedmethod resides in holding the externalV surface of a portion adjacent the lend of the tubing to a diameter less than the greatest diameter of the external surface o'f the dared portion of the tubing. The thickness of the wall kclose by the end is reduced, however, and vpart of the wall material is swaged downward slightly into that portion of the tubing which is dared. By` thus holding the edge of the tube from any substantial expansion, coupled with the slight upsetting or swaging of the material toward where the greatest stretch of the tubing will normally occur, it is possible to flare the present available tubing without rupture or weakening of the tube wall.

Referring -now to Figure l, vthere is shown in separated relation the various parts of a pre- 2 ferred form of flaring means for practicing my invention. These comprise a block or clamping ring I0, a pair of jaw holders I2, I4, a pair of ila-ring jaws I 6, I8, and a aring plunger 20.

The block I d may be secured in a vise but its outer` lsurface is knurled so that it can rbe held in ones hand. It has a tapered axial hole Illa extending through it.

The jaw holders I2, lll have exterior curved surfaces I2a, Ida tapered to fit the wall of the hole Illa in the clamping ring It, and also have opposed dat surfaces I2b and hib. Each holder has a semi-cylindrical recess I2c, Ic which terminates in an enlargement i211, Ild at the upper end to provide a shoulder I2e, Ite. When the holders are together they provide a cylindrical hole between them for 'the reception of the liaring jaws I5 and I8'.

These jaws have 'external cylindrical surfaces Ilia, Ilia and external shoulders Ib, Ib to fit the hole formed by the holders I2, Hi. A clamping jaw may be held toa holder by a screw 22, whose threaded portion passes through a shouldered hole in the holder and screws into a tapped hole in the jaw. Each jaw hasfor most of its length a semi-cylindrical recess Ic, ISC, but at its upper end is particularly formed with tapered surfaces ltd, Id which diverge outward at an angle from the axis equal to one-half the degree of flare to be imposed on the tubing 24. Each outwardly 'tapered surface Idd, I8d extends Ialong the axis as far as desired to` make the length of the flare wanted. From the ring of greatest diameter of the outwardly flared surface, the wall is tapered inward sharply, as at It'e and Ie, to terminate in a short cylindrical portion It?, Itf, a little larger than the outside dimension of the unared tube.

The vfla-ring plunger 2d has a cylindrical portion 2da substantially the same size as the hole in the tubing to be flared. From this portion, to another cylindrical portion Zlib, is a tapered or flaring surface 2de making 4an angle with the axis of the plunger equal to the degree of flare to be imposed on the tubing. The diameter of the larger cylindrical portion 26D of the plunger is slightly less than that of the short cylindrical hole formed by the portions IBf and ISf of the flaring jaws.

In the practice of my improved method the tubing 24 to be flared is placed between the jaws I6 and I8 with its end 24a extending slightly beyond the ends of the jaws as shown in Figure 2. The jaws are set in the holders I2 and I4 and the latter in the ring I il. The larger ends of the holders are ,preferably tapped lightly with a hammer to tighten the jaws against the tubing. The plunger 2i] is inserted in the tubing with its flared portion 20c resting on the edge 24a of the tube. The latter edge, by the way,

need not be out or finished with any special care but maybe the edge left when tubing is out with a hack saw or pipe cutter.

The plunger is now subjected to hammer blows until the aring is completed. In Figures 4, 5V

and 6 I have attempted to illustrate what I believe occurs as the flaring takes place. As the plunger is driven into the tubing the holders l2 and I4 settle very firmly into the ring I0, causing the jaws IS and I8 to grip more tightly the tubing 24 between them. As the flared surface 20c of the plunger moves downward it acts with swaging effect on the tube wall, gradually thinu ning it opposite the portions lf and I8f of the jaws. Part of the metal displaced by the swaging action may move upward to swell very slightly the edge 24a of the tubing, but for the most part it moves downward and apparently slightly thickens the tubing just below the said portions if and I8f of the jaws.

As the progress of the plunger continues, the

. tube is forced outward into the space around it,

formed by the tapered surfaces ld, ld, le and l8e, until when the plunger bottoms (that is, when the lower end of its flared portion is opposite the lower ends of the flared portions of the flaring jaws) the wall of the tube is flared outward desired and as shown in Figure 6.

'The holders I2 and I4 can then be tapped lightly at their smaller end to free them from the ring, the latter can be slipped downward, and the holders and jaws separated to remove them from the tubing. Either before this is doneor afterward the plunger can be withdrawn'from the tubing. The end of the tubing will appear generally as shown in Figure 7 and the final step is to clean off the necked portion 24h and edge 24a and thus produce the finished flared end 24e shown in Figure 8.

Examination of the ared end discloses no rupture, tear or crack in the tubing. The entire flared portion is intact. If anything, it may be slightly stronger than would be the case if ared in the usual way, because despite the increased circumferential size, the wall thickness of the flared portion is not appreciably thinned but usually measures as thick as the original thickness of the tube wall.

I claim:

1. Means for flaring tubing comprising a die having a cylindrical wall fitting the normal external wall of the tubing, a conically flared wall for determining the degree of flare of the tubing, and ak short cylindrical wall adjacent the large end of said flared wall providing an open--A ing slightly larger than the external dimensions of the tubing; and a plunger for insertion in the tubing having a conically flared surface whose larger end is slightly smaller than the said opening whereby upon the plunger being inserted into the tubing until the said larger end of the flared surface of the plunger is opposite the saidvshort cylindrical wall of the die, the tubing is flared against the flared surface of the die and its wall opposite the said short cylindrical Wall 0f the die is appreciably thinned. I

2. Means for forming a conical flared end on tubing comprising a die having a cylindrical section fitting the normal external wall of the tubing, a conical section diverging outward from the end of the cylindrical section and a conical surface converging inward from the larger end of the diverging conical section, and a plunger for insertion in the tubing having a leading cylindrical section fitting the normal internal wall of the tubing and a conical section diverglng outward from the end of the cylindrical section; the diverging conical section of the plunger having its largest external diameter substantially the same as the smallest internal diameter of the inwardly converging conical section of the die,

whereby the conical section of the plunger and the converging conical section of the die effect a swaging of the tubing as the plunger is inserted therein.

3. Means for forming a conical flared end on tubing comprising a die having a cylindrical surface fitting the normal external wall of the tubing, a conical surface diverging outward from the end of the said cylindrical surface, a conical surface converging inward from the end of the diverging conical` surface, and a short cylindrical surface extending from the end of the converging conical surface; and a plunger for insertion in the tubing having a leading cylindrical surface fitting the normal internal wall of the tubing, a conical surface diverging outward from the end of the last said cylindrical surface, and a second cylindrical surface extending from the end of said diverging conical surface; the diameter of the said second cylindrical surface of the plunger being substantially the same as the diameter of the said short cylindrical surface of the die.

4. Means for forming a conical flared end on tubing comprising a die having a cylindrical surface fitting the normal external wall of the tubing, a conical surface diverging outward from the end of said cylindrical surface for determining the flared end desired, a reentrant surface at the larger end of said conical surface having its smallest diameter substantially the same as the diameter of the normal external wall of the tub- I ing; and a plunger for insertion in the tubing having a cylindrical surface fitting the normal internal wall of the tubing, a conical surface diverging outward from the end of the last said cylindrical surface to a diameter only slightly smaller than the said smallest diameter of the reentrant surface of 'the die; the said reentrant surface of the die and the conical surface of the plunger coacting to swage the tubing as the plunger is inserted, thereby maintaining the wall of the flared end of the tubing substantially at the same thickness as that of the unflared tubing wall and causing the tubing between the said reentrant wall and the conical surface of the plunger having the largest diameter to be appreciably thinned.

JAMES R. WELSHMAN.

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

UNITED STATES PATENTS Number Name Date 410,000 Matheson Aug. 27, 1889 1,791,887 Davies et al. Feb. 10, 1931 1,817,854 Sorenson Aug. 4, 1931 1,724.920 Fischer Aug. 20, 1929 1,804,815 Schultis May 12, 1931 2,024,803 Nelson Dec. 17, 1935 412,389 Isherwood Oct. 8, 1889 606,046 Chillingworth June 21, 1898 FOREIGN PATENTS Number Country Date 5,500 Great Britain Mar. 11, 1896