US3466707A - Flaring tool - Google Patents

Description

Sept. 16, 1969 G. T. CLICK ET AL FLARING TOOL Filed Nov. 7'. 1966 Gay/0n 7. (Y/ck (fame: M Gray, di'.

1 .VVEN'TORJ BY W United States Patent U.S. Cl. 18-19 6 Claims ABSTRACT OF THE DISCLOSURE Apparatus for flaring plastic or plastic-like tubing characterized by compressor means having a plurality of frusto-conical sections which perform a locking function in conjunction with holding means and which compressor means flare the tubing by pressing the tubing against the holding means.

The invention relates to an apparatus for flaring the ends of flexible plastic or plastic like tubing to make coupling joints. More particularly, the invention relates to an improved flaring tool that can be conveniently employed with flexible plastic tubing such as polyethylene or polybutene to produce a flared tube of any one of a number of different sizes.

Prior to the present invention, much difliculty has attended the joining together of sections of plastic tubing. One method has been to fuse the sections of the pipe together. This method is generally undesirable, in view of the nature of plastic tubing, and results quite often in the mutilation of the pipe. Another method of joining sections has been the use of solvents which attack the various types of plastic pipe. By coating the segments of the pipe to be joined with the solvent, a tacky surface is produced which enables the pipe to be fitted together. While fairly effective with specified plastic materials, the method does not have utility with all flexible plastics and consequently is not generally adopted. A third method is the practice of flaring the ends of the flexible tubing for use in conjunction with conventional fittings. The application of this method has been limited, however, by the lack of an effective tool for flaring plastic tubing. One flaring tool currently in use requires the addition of heat in the area to be flared to soften the tubing and enhance the flaring. Prior to the invention, therefore, no effective method or device for the flaring of flexible plastic tubing without the application of heat was known.

Accordingly, it has been an object of the invention to provide an effective tool for the flaring of segments of flexible plastic tubing. More particularly, it has been an object of the invention to provide a flaring tool which is especially effective in the flaring of polybutene and polyethylene tubing.

The objects of the invention are obtained by the provision of a flaring tool characterized by an especially unique compressor member and other features. Broadly, the invention comprises a means or mechanism for holding the tubing, means for positioning and actuating a compressor member in registration with the holding means, the compressor means being described as comprised of three frusto-conical sections, including a frustoconical nose section, a frusto-conical section of slight taper connected through its smaller base to the larger base of the nose section, and the third frusto-conical section being connected through its smaller base and a concave annular fillet to the larger base of the frusto-conical section of slight taper. Reference is made to the accompanying drawing in which the same numerals are used to designate identical parts in all the figures.

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FIGURE I is a perspective view of a flaring tool embodying the invention.

FIGURE II is a section on line 22 of FIGURE I.

FIGURE III shows the special plug or compressor member of the invention.

FIGURE IV shows a segment of flared polybutene tubing.

More particularly, the drawings show a pair of clamping bars 1 and 2 for receiving and holding the tubing which are preferably connected at one end thereof by a link 11. The body of link 11 is preferably rectangular in cross section and is pivoted by the rivet 13 in a slot 14 formed at the end of the bars 1 and 2. The rectangular portion of link 11 can be swung into the recess 14 formed in the end of the bars 1 and 2 by means of pivot pin 13 to receive the same, and the outer end of the link 11 is threaded to receive the wing nut 7A by which the bars at that end can be clamped together. The opposite ends of the clamping bars 1 and 2 are held together by any suitable means which will permit the bars to be opened somewhat, as for example, threaded pin or bolt 15 and wing nut 7B. The details of the adjustment mechanism for the clamping bars form no part of the present invention and are disclosed more particularly in U.S. Patent 1,724,697, to Dobrick. Formed in the adjacent edges of the bars 1 and 2 are a series of serrated semicircular registering openings which together form circular openings 20A, 20B and 20C, these circular openings each being joined by the circular flaring recesses 8A, 8B and 8C. The dimensions of the flared recessed areas 8A, 8B and 8C, should be large enough to accommodate the flared portion of the tubing, as more particularly hereinafter described. As noted, the circular openings beneath each flaring recess are serrated or threaded as seen at 20A of FIGURE II, in order to aid in securing a tube placed therein and to retard any longitudinal movement when the clamping bars are tightened on the tube. The openings 20A, 20B and 20C are of different sizes to accommodate tubes of different standard outside diameters. While the drawing illustrates only three sets of openings and recesses, it will be appreciated that more or less may be provided, so as to accommodate various standard size tubings. The higher resilience of flexible plastic tubings makes it necessary to make the angle of compression in the recessed areas of the clamping bars greater than the angle desired in the finished flared tubing, for example, from 5 to 25 degrees greater.

In conjunction with the chamfered or recessed area 8A, and the opening 20A, for example, a tube 6 is flared by a compressor 4 which is secured to the threaded bolt 9 having the perforated head 19. The plug 4 may be fastened to the bolt 9 in a variety of ways, the only requirement being that the plng does not rotate once contact is made with the tubing and as the plug advances into the recess 20A. Thus, a snap ring groove combination may be utilized, as shown at 21, or a pin or pins with a slot in rod 9 may be provided to allow rotation with respect to rod 9. A ball bearing 24 is provided with grooves 25 and bolt receiving slot 26 to absorb the thrust of bolt 9 and facilitate turning. Rod 10 may be provided in various lengths so that as much leverage as is desired can be secured by sliding the rod through head 19. The bolt 9 is threaded through the closed end of the generally U-shaped yoke 3. It will be observed that the yoke 3 has two angled slots 12A and 12B equally distant along the legs of the yoke in order to lock the yoke in place for operation. Thus the yoke is positioned in operation, as shown in FIGURE I, at an angle to the clamping bars.

A significant feature of the invention is the compressor or plug 4, more particularly shown in FIGURE IH of the drawing. The compressor 4 is a member having a body segment 16 and a frustoconical section 18 which joins a rather elongated frustoconical section through a circular concave surface 22. The taper in section 5 which renders the section frustoconcial in shape is slight, for example, on the order of a few thousandths of an inch magnitude. A most suitable taper for section 5 has been a change in diameter of from to 30 thousandths of an inch over the length of the section. The drawing exaggerates the angle of the taper in order to emphasize its presence. Frustoconical section 5 integrally joins nose section 17 of the plug. It has been found that a compression member wherein the distance between A and B shown in FIGURE III of the drawing (i.e., the length of section 5 plus the fillet or concave surface 22) bears a ratio of from about 0.25 to 0.4 to the outside diameter of the nose of the tubing fitting to which the flared pipe will be coupled is most suitable.

The turning fillet 22 is in actuality a concave surface extending circumferentially around the plug wherein the concave arc is an arc of circle of such size as to cause the tubing to flare outwardly. An example of a suitable dimension, depending of course on the size of the plug, etc., which has been found suitable, is an arc of a circle having a radius of about to A; of an inch in length.

For operation, the wing nuts 7A and 7B are loosened and a section of plastic tubing 6 is inserted in a holding opening (e.g., 20A) corresponding to the size of the tubing. The wing nuts are tightened to provide a holding action on the tubing. Yoke 3 is then inserted in place above the tubing and is locked in place by virtue of the angled slots. Lever handle 10 is then turned until the compressor plug 4 engages the end of the tube to be flared. Continued rotation of 10 will advance plug section 5 into tube 6 until the top of the tube engages section 18. Further rotation of 10 will advance plug 4 and tubing 6 together downward through the circular opening 20A in the clamping bars until the gradually increasing outer diameter of the plug section 5 locks the tubing against the upper portion of the opening. The plug 4 will continue to slide inside the tubing, now locked in place, thus expanding the tubing over section 18 of the plug and forming a flare 23 with a greater angle than the desired angle. By reversing the turn of lever 10 the plug 4 may be removed. At this time the plastic tube will undergo some elastic recovery leaving a flare of the desired angle. The tube with flare 23 may be withdrawn from the clamping bars 1 and 2 by loosening the wing nuts 7A and 7B.

It will be appreciated by those of skill in the art that the present invention provides an admirable solution to the problem of flaring plastic tubing. Accordingly, while we have shown and described the invention as embodied in the form which is best adapted to carry out its purposes it will be understood that it is capable of modifications and it is not desired to be limited in the interpretation of the following claims except as may be necessitated by the state of the prior art.

We claim:

1. Apparatus for flaring plastic or plastic like tubing comprising, holding means for holding a section of tubing, said holding means having at least one recess to receive the flared portion of the tubing as it is flared, means detachably connected to said holding means for positioning and actuating compressor means to bring said compressor means into registration with the holding means and said recess, and compressor means rotatively attached to said actuating means, said compressor means comprising a nose section, a frusto-conical section of slight taper connected through its smaller base to the nose section, said slightly tapered frusto-conical section being of such taper as to provide locking of a section of tubing in said holding means, and another larger frusto-conical section connected through its smaller base and a concave annular fillet to the larger base of the frusto-conical section of slight taper for flaring a portion of said tubing section by pressing the portion of tubing to be flared against said recess.

2. The apparatus of claim 1 wherein the angle of compression in said recess is greater than the angle of the flare desired in the tubing.

3. The apparatus of claim 2 wherein the angle of compression is from 5 degrees to 25 degrees greater than the angle of the flare desired in the tubing.

4. The apparatus of claim 1 wherein the ratio of the sum of the height of the frusto-conical section of slight taper and the length of the concave annular fillet connecting said slight taper section with the third frusto-conical section, to the outside diameter of a nose section of a tubing fitting to be joined with the flared tubing is from about 0.25 to 0.4, and wherein the angle of compression in said recess is greater than the angle desired in the tubing to be flared.

5. The apparatus of claim 1 wherein the holding means comprises a pair of associated clamping bars having at least one pair of semicircular registering openings which form a circular opening, and having at least one recess joining the circular opening for receiving a flared section of tubing; and wherein the positioning and actuating means comprises yoke means.

6. The apparatus of claim 5 wherein the ratio of the sum of the height of the frusto-conical section of slight taper and the length of the concave annular fillet connecting said slight taper section with the third frusto-conical section, to the outside diameter of a nose section of a tubing fitting to be joined with the flared tubing is from about 0.25 to 0.4.

References Cited UNITED STATES PATENTS 1,571,267 2/ 1926 Hartsock 723 17 XR 2,226,852 12/1940 Dobrick 723 17 2,278,932 4/ 1942 Kellems 723l7 2,853,116 9/1958 Wilson 72317 XR 3,142,868 8/1964 Blount 18-19 3,335,484 8/1967 Parker et a1. l819 XR 3,359,599 12/1967 Martin et al. 18-19 WILLIAM J. STEPHENSON, Primary Examiner US. Cl. X.R. 72-3 l7

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