US2525093A - Means for coiling tubing - Google Patents

Description

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Filed NOV. 4, 1944 M. T. cAHENzLl, JR

MEANS FOR COILING TUBING I oct. 1o, 195o Patented Oct. 10, 1950 U-NiifeofsTATEs VPATEN'I' OFFICE FOR COILING TUBING Martin T, CahenzlLfJr., Chicago, Ill., assignor to The Harry Alter Company, Chicago, Ill., a corporation of Illinois Application Nevember 4,1944Qseria1 No. 561,959

' a metering tube for refrigerants in refrigerating systems. `Such a tube eliminates the need'of pin hole orifices, expansion valves, and the like, and gauges the flow of refrigerant from `the compressor or reservoir to the evaporator of a refrigerating system. It has been found that if the tubing is wound into a relatively tight elongated coil, a considerable saving results in the amount of tubing needed. It has also been found that the smaller the inside diameter of the coil, the less tubing is needed to provide adequate metering. Of course, in winding the tubing it is essential that the bore of the tubing remain constant throughout the coil. The instant invention is primarily directed to the'coiling of such tubing into a coil of a relatively small inside diameter, the invention being highly desirable for use in connection with the ceiling of suchl tubing into-a coil having an inside diameter of three-sixteenths inch or less, and may be used to provide a coil having an inside diameter of one-sixteenth inch, without altering the boreof the tubing throughout the length of the coil. `I am not aware that tubing of this character has ever been wound into a coil of thatsmall size.

In the winding of an elongated' coil about' a mandrel, especially when that mandrel `has a diameter of one-eighth inch or less, the mandrel in most instances will not have sui'licient rigidity to properly support the tubing during the winding operation.V Itis therefore an important object of the invention to provide a machine for winding tubing into a coil and automatically compensate for the lack of rigidity and strength in the mandrel about which the coil is being wound.

Another important object of this'invention is the provision of means for winding a relatively small diameter tube into a coil of relatively small inside diameter without crushing the tube.

Another object of the instant invention is the provision of a machine for winding a coil of tubing about a freely floating mandrel.

Also anA object of the instant invention is the provision of a machine for winding a coil of tubing about a mandrel in such a manner that the progressively growing coilsupports the mandrel in proper position during the winding operation.

Still a further object of the instant invention is the provision of tube winding machine comprising a chuck arranged to hold both the end of the tubing to be wound and the mandrel about which it is to be wound, and means to insure a proper winding of the tubing about the free floating portion of the mandrel.

Another feature of the invention resides in the provision of a machine for winding tubing into an elongated coil and means for insuring that the tubing is wound underthe proper tension and in such a manner that the coil is formed in a straight line regardless of the rigidity or strength of the mandrel along which the coil is wound.

Itis also a feature of the instant invention to provide a machine for winding an elongated coil of relatively small inside-diameter, the machine being so arranged as to automatically maintain the coil being wound'straight and true regardless of the internal support for the coil, the machine providing a reaction against the feeding tension on the material being wound in the nature of a rest or bearing surface for the coil so as to maintain the coil definitely in a straight line during the winding operation.

Still a further object of the invention resides in the'provision of a machine for providing a metering tube for a refrigeration system, which tube is in the form of a tightly wound elongated coil having an extremely small inside diameter.

While some of the more salient features, characteristics and advantages ofthe instant invention have been above pointed out, others will become apparent from the following disclosures, taken in conjunction with the accompanying drawing, in which:

Figure 1 is a side elevational view of a machine embodying the principles of the instant invention;

Figure 2 is an enlarged fragmentary transverse vertical sectional View, with parts shown in elevation and parts omitted, taken substantially 3 as indicated by the line'II-II of Figure 1, looking in the direction of the arrows;

Figure 3 is an enlarged fragmentary part sectional, part elevational view of a portion of the machine, illustrating the winding of the tube into a coil;

Figure 4 is an enlarged transverse vertical sectional view taken substantially as indicated by the line IV--IV of Figure 3; and

Figure 5 is a View similar in character and 1oca-. tion toFigure 3, but showing a slightly different form of mandrel construction.

As shown on the drawings:

In the illustrated embodiment of the instant invention there is-shown a coil winding machine which is roughly of the appearance and embodies certain of the operating principles of a lathe.

'Ihe machine includes a supporting base I havingl on one end thereof a suitable gear housing 2. Mounted Ona shaft projecting from one end of the gear housing is a pulley 3 over which a belt 4 may be trained from a drive pulley 5 on the armature shaft of a motor 6 or equivalent prime mover. Mounted upon a shaft projecting from the other side ofthe gear housing 2 is a master chuck 'l substantially of the character used on the commonly known lathes.

An auxiliary chuck 8 embodying principles of the instant invention may be secured within the clamps of the master chuck I in a well known manner. With reference more particularly to Figures 3 and 4, it will be seen that the auxiliary chuck has a central bore in one end for the reception of the head 9 of a mandrel III. The mandrel head is held xedly in place within the bore of the auxiliary chuck by a suitable set screw I I or equivalent means. It will be apparent that the head 9 is preferably considerably'larger than the mandrel itself so that mandrels of various diameters, but all having the same diameter head may be used in the chuck 8. Y

The auxiliaryv chuck is also provided with an eccentric or olsetsocket for the reception of an end of ythe tube I2 to be coiled. This socket is provided by means of a recess in the body portion of the chuck and a complemental recess in a cover piece I3 hinged as-atl to a boss ori the chuck. The free end of the top piece I3 is bifurcated as indicated at Itiin Figure 4 to pass over the shank of an eye-bolt I6' pinned between a pair of lugs I'I on the chuck, and this top piece may be held down tightly against the end of the tube I2 by means of a suitable wing nut I8 engaged around the eyebolt I6. It will be appreciated that with this arrangement, the chuck is able to accommodate tubes of different outside diameters.

It will be noted, therefore, that the instant machine is capable of winding coils of different inside diameters and at the same time capable of utiliz'- ing tubing having different outside diameters for winding such coils.

Mounted on the bed of the base frame I is a pair of spaced upright supports I9-I9. An angular frame member 29 is secured to the upper face of each of the uprights I9 in any suitable manner such as by bolts 29a. The lower ends of the angle frames -29 carry an elongated bar or rail2I, the upper face of which functions as an underrest for the coil during the winding operation. Secured to the front face of the rail 2I is another outside rail 22 which also provides a bearing surface for the coil being wound as will be explained more fully later herein. The upper ends of the angle frames 20--20 carry a rail v23 securedthereto by bolts 24 extending through elongated bolt openings 25 in the rail, thus, the upper rail 23 is adjustable vertically relatively to the lower rail 22 to selectively vary the width of a slot 26 between these rails. The slot 26 is of a substantial depth defined by the thickness of the rails 22 and 23, which will normally greatly exceed the diameter of the tubing being wound. During the Winding operation the tube is fed through the slot 26, and the slot may be varied to accommodate tubes of different diameters. It will be appreciated that the rail 22 and the inside rail 2I may be formed in one integral structure if so desired. Likewise, in the event only a certain diameter tube is to be used extensively on one machine, the rails 22 and 23 might also be integral with each other with a slot provided therein.

In the oper-ation of making a coil, a mandrel of the desired diameter is selected. The head of this mandrel is locked in the auxiliary chuck 8, and it will be noted that with the exception of the head portion within the chuck, the mandrel floats freely in the direction of development of the coil, no other support being provided for that mandrel. The end 0f the tube to be wound is unturned substantially at right angles to the length of tubing and locked in the upper socket of the auxiliary chuck 8. The tubing is then inserted in the slot 26 at the front of the device so that the tubing may be fed through this slot during the winding of the coil. The machine may then be started, and the tube fed through the slot 26 from a supply roll of tubing. Tension may beV placed upon the tubing during the feeding, by the hands of the operator or otherwise, if so desired, and some tension is placed upon the tubing by its passage through the slot 26. The slot is preferably either adjusted or originally made to such size as to intimately receive the tubing so that as the tubing is turned into a coil, there will be a definite pressure cf the tubing against the upper side of the slot thus resulting in tension being placed upon the tubing during the winding operation.

As the auxiliary chuck 8 is rotated, the tubing is coiled around the mandrel I9. During the coiling operation the structure provides two bearing points for the coil being formed. These bearing points are indicated at 21 and 28 in Figure 2. The bearing point 21 is against the inside of the front rail 22 and the bearing point 28 is on the upper edge of the inner rail 2 I. The bearing of the coiled tube against these points or surfaces provides an adequate reaction to the tension upon the tubing as it is fed to the mandrel and the coil is maintained straight and true during the entire winding operation. By virtue of the slot feed and the bearing surfaces there adjacent, the tubing will wind into only a single lap coil.

It will be appreciated that if the coil is to have an inside diameter of one-sixteenth inch, for example, the mandrel is not of suicient rigidity and strength to support the coil during the winding operation, but the mandrelwould give so that the coil would not be true if it ultimately were wound without trouble. However, with the winding arrangement above described, the pro.- gressively completed coil supports the floating portion of the mandrel and holds that mandrel in proper position. All the mandrel need do is determine the inside diameter of the resultant coil. As the winding continues, a single layer tightly wound coil 29 results.

In many cases the tubing itself will be of a larger outside diameter than the internal diam- .nn l

eter of the coil being formed. As an example of the material used, metering tubing, sometimes referred to as capillary tubing, for refrigerating systems is preferably of dead soft copper having an internal diameter varying from 0.025 inch to approximately 0.08 inch, depending upon the particular refrigerant used and the size of "the refrigerating system. With the instant invention, such tubing may be Wound into a coil having an internal diameter as small as one-sixteenth inch, without affecting the uniformity of the bore of the tubing.

After the Winding has progressed until a coil of the desired length has been formed, the tube may be cut outside of the machine. The tubing is then slid through the remainder of the slot 26, if there is any such remainder, and stripped from the mandrel, and the Winding process may be repeated. In some instances, the stripping of the coil from the mandrel may be expedited by turning the machine backward a partial revolution so as to slightly loosen the coil around the mandrel. Obviously, Where many coils are to be wound of Y exactly the same length, it is preferable to utilize rails or other slot defining means of such length 6 maintained. Variances in the length of the wound coil may readily be provided, and variances in the diameter of the tubing used, or the variances in the diameter of the coil itself may be had at will through a small number of adjustments.

It Will, of course, be understood that various details of construction may be varied through a wide range Without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claim.

I claim as my invention:

In a tube coiling machine, rotary means, an elongated mandrel around which a single layer coil of tubing is to be Wound carried adjacent one end by said means, and Xed guide means defining an elongated slot adjacent and substantially parallel to said mandrel through which tubing to be wound is fed to the mandrel, said slot having a depth greatly exceeding the diameter of the tubinl said guide means` being shaped to provide a bearing surface to. one side of said slot against as to provide a slot just as long as the intended coil. This eliminates any difficulty in urging the projecting end of the tube through the remainder of the slot 26 after the coil has been Wound, it being too much trouble to loosen the bolts 24-24 after each winding operation.

In Figure 5 I have shown a slightly different form of mandrel construction in that the mandrel Illa is provided with a head 9a having a tapering neck portion 30. the coil 29 Will therefore be of gradually lessening diameter until the uniform mandrel lila is reached. This arrangement is desirable for use with a tube of larger diameter or one having relatively thick walls to ease the strain on both the tube and machine at the start-of the coiling operation.

In the operation of the machine, the Winding or a tube into a coil requires only a fraction of a minute, and coils may be produced exceedingly vrapidly and very economically. f

From the foregoing, it is apparent that I have provided a novel machine for formulating elongated coils, the invention being highly desirable for the formulation of elongated coils having eX- tremely small internal diameters in -comparison with the outside diameter of the material being coiled. It will also be noted that with this invention metering tubes for refrigerators may be provided with rapidity, great economy, little labor, and with a resultant materialjsaving in the amount of tubing necessary to adequately meter the refrigerant for a particular installation. l'ur-l thermore, the coil'is woundtruly and uniformly and the'uniformity of the bore in the4 tubing is The first few turns of f" which the Wound coil is formed, and a rest eX- tending parallel to said slot on the inside of said guide means and providing another bearing surface against Which the coil is Wound.

' MARTIN T. CAHENZLI, JR.

REFERENCES CITED The following references are of record in the i'lle of this patent:

l i .UNITED- STATES PATENTS Number Name Date Re. 814 Perkins Sept. 20, 1859 175,484 Metcalf Mar. 28, 1876 531,673 Almond Jan. 1, 1895 561,579 Gare 1 June 9, 1896 720,092 Aiken Feb. 10, 1903 911,296 Daniels Feb. 2, 1909 952,582 Ritter Mar. 22, 1910 1,063,505 Byrnes June 3, 1913 1,124,874 Diebel Jan. 12, 1915 1,238,445 Scholl Aug. 28, 1917 1,289,453 Hyatt Dec. 31, 1918 1,627,681 Woodruff May 10, 1927 1,632,095 Newton June 14, 1927 1,710,634 Schlaich Apr. 23, 1929 1,868,063 Harter July 19, 1932 2,365,953 Hauton Dec. 26, 1944 FOREIGN PATENTS Number Country Date 154,111 1 Australia Aug. 25, 1938 268,685 Great Britain Apr. 7, 1927 54, France` Aug. 17, 1791 117,817 vSwitzerland Dec. 1, 1926

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