US2896688A - Machine having a pivoted former and clamp for forming flattened helical coils - Google Patents

Description

y 1959 N. GUEVARA 2,896,688

MACHINE HAVING A PIVOTED FORMER AND CLAMP FOR FORMING FLATTENED HELICAL COILS Filed June 7. 1954 5 Sheets-Sheet 1 INVENTOR;

July 28, 1959 N. GUEVARA MACHINE HAVING A PIVOTED FORMER AND CLAMP FOR FORMING FLATTENED HELICAL COILS 5 She ets-Sheet 2 Filed June 7. 1954 y 28, 1959 N. GUEVARA MACHINE HAVING A PIVOTED FORMER AND CLAMP FOR FORMING FLATTENED HELICAL cons k 5 Sheets-Sheet 5" Filed Junel 7. 1 954 if 5% z j; //II //R\ \I K M H. k 30 J; i My zz fly IN VEN TOR. #155041; 012411 y 28, 1959 N. GUEVARA I 2,896,688

MACHINE HAVING A PIVOTED FORMER AND CLAMP FOR FORMING FLATTENE'D HELICAL COILS Filed June 7. 1954 s sheets-sheet 4 INVENTOR.

zwawzfls 647 x4214 July 28, 1959 Y GUEVARA 2,896,688

MACHINE HAVING A PIVOTED FORMER AND CLAMP FOR FORMING FLATTENED HELICALCOILS Filed'June 7, 1954 5 Sheets-Sheet 5 IN V EN TOR.

M/CHOLAS 72225! Nicholas Guevara, Bronx, NY. Application June 7, 1954, Serial No. 434,956

8 Claims. (Cl. 153-40) This invention relates to a machine for forming coils of a flattened or elongated shape and is especially adapted to the forming of such coils from tubing, although the machine can be used for forming coils of solid stock should occasion for such coils arise.

Odds of tubing of a flattened or elongated form are much used in heat exchange devices, such as for heating coils in hot water heaters or the like, or for refrigeration or condensing coils of refrigeration or air conditioning apparatus. The forming of such flattened or elongated coils presents numerous difficulties not encountered in the winding of cylindrical helical coils, as they cannot be formed by simply winding to a uniform curvature. Two series of spaced bends are required and the stock and partially formed coil have to be shifted between each bend. Difiiculties are particularly encountered where the coils are formed of copper or other relatively soft metal and are thin walled. In such cases the means used for manipulation of the tubing must be such as to prevent collapse or damage to the tubing. Tubing with fins is largely used for the purpose, and it is important not to damage the fins. The difliculties of forming coils of soft metal have often been such that it has been necessary to use an internal mandrel or filler. With the present machine this is usually unnecessary, although a mandrel may be used if found desirable.

It is the object of the present invention to provide a machine for bending tubing or the like into the form of flattened or elongated helical coils of accurate dimensions and shape in a rapid and eflicient manner without damage to the material being worked upon, and with a minimum of hand manipulation. More specific objects and advantages will appear in connection with the description of one particular embodiment of the invention shown in the accompanying drawings and illustrative of the principles thereof.

In the drawings:

Figure 1 is a perspective view of the machine showing the parts in the position to receive the end of a piece of tubing to be operated on.

Figure 2 is a perspective view taken from a different position.

Figure 3 is a sectional view of the shaft, sleeve and helical bending former taken on line 3-30f Fig. 1.

Figure 4 is a fragmentary perspective view showing a partially formed coilresting on the sweep table at an intermediate point of the bending operation.

Figure 5 is a fragmentary vertical cross sectional view taken on line 5--5 of Fig. 1.

Figure 6 is a plan view of the lead-in guide, bending former and lower clamping member, the upper clamping member being broken away.

Figure 7 is a view similar to Fig. 6 after the clamp has been swung over and the bend made.

Figure 8 is a vertical cross section taken at the position indicated by line 8--8 of Fig. 7, and showing the clamp 2,896,688 Patented July 2%, 1959 opened preparatory to the return of the sweep table and clamp to the position shown in Fig. 2.

Figure 9 is a fragmentary view in vertical section showing a modified form of clamp suitable for use with corrugated tubing.

Figures 10, 11, 12 and 13 are fragmentary views in perspective with parts broken away showing various positions of the bending former, and sleeve and shaft for carrying the bending former and sweep table.

Referring to the drawings in detail the bending machine is shown as mounted on a table or bench 20 on which are mounted a pair of pillow blocks 22 and 24, in which is journaled the sleeve 26. through which passes a shaft 28. In the example of the invention shown the table is horizontal, but it might be mounted at an angle or in a vertical plane, in which event thesleeve and shaft would be similarly mounted so as to be parallel to the table surface. Fixed to the end of the shaft 28 is a bending former 30 which is preferably in the form of a helix segment or worm having a helical groove 32 therein and having a flattened or cut away side 34. The end of the sleeve and the end of the shaft carrying the helix segment 30 project beyond the pillow block 24 and overhang a depressed portion or channel 36 formed in the top of the table 20. Mounted in a shallow. transverse groove 38 in the top of the table is a channeled lead-in guide 40 shaped to receive the tube to be bent and which is preferably mounted so as to be capable of a slight lateral motion at its end which is adjacent to the helix segment 30. This movement is preferably provided for by mounting the guide on the end of a bar 41 pivoted at its rear. end as indicated at 42; the channel 38 being slightly wider than the guide. The purpose of providing for this movement is to enable the guide and the tube carried thereby to keep in alignment with the groove in the helix segment as the latter is rotated.

Mounted adjacent to that part of the table beyond the depressed channel portion 36 is a movable plate or sweep table 44. This is mounted on the lower face of a pivot block 46 which is fixed to the end of the sleeve 26. Mounted on the sweep table 4-4 adjacent to the pivot block 46 is a tube clamp which comprises a lower clamp member 50 having a groove 52 in substantial alignment with the groove in the guide member 40. Pivoted in ears 54 on the lower clamp member 50 is a pivoted clamp. member 56 having a groove 58 in its lower surface matching the groove 52 so that the two clamping members when brought together will grip and hold an end of the tube to be bent. The clamping member 56 has a projecting arm 60 which is engaged by the rod of a piston 62 in an air cylinder 64 so that by turning the air pressure on or off the clamp may be tightly closed or opened. The cylinder 64 is mounted on a bracket 64a secured to the sweep table 44. A spring 65 moves the clamp to open position when the air pressure is released. Air is preferably supplied to the cylinder 64 through a flexible tube 66 so as to permit the cylinder to swing over with the clamp and sweep table 44.

Any suitable means maybe employed for swinging over the sweep table and clamp, so as to bend the tubing around the helix segment or worm 30. In the construction shown this is accomplished by means of an air cylinder 68, the piston rod 70 of which is connected to a chain '72 which winds around and is secured to a pulley 74. The shaft 78 of the pulley 74 carries a sprocket wheel 80 which drives a chain 82 running over a second sprocket wheel 8 mountedon the sleeve 26. Operation of the air cylinder 68 will thus rotate the sleeve 26 through an angle of it being returned to initial position on release of the air pressure by the spring 86.

The bending former, worm or helix segment 30, as

above described, is fixed on the end of shaft 28 which is rotatable within the sleeve 26. The shaft is provided with a pin 88 which works in a slot 90 extending a quarter of the way around the sleeve 26. The outer end of the shaft projects beyond the end of the sleeve and has fixed to it a collar 92 in which is mounted a pin 94 which projects radially from the axis of shaft 28 at an angle of 180 from the direction of pin 88. During the return movement of the sleeve and shaft the pin 94 engages and is stopped by the end 96 of a pivoted block 98 which is actuated in one direction by the piston rod 100 of an air cylinder 102 in the other direction by a spring 103;. This stops the return movement of the shaft and worm in a 90 position, while the sleeve and sweep table swing back through the entire 180 to initial position. The collar 92, shaft 28 and worm 30 have a rotative torque applied to them by a spring 104 which acts on these parts in the same sense as the spring 86 acts on the sleeve 26 and sweep table 44.

Any suitable valve arrangement for controlling the pressures to the various cylinders may be employed, but preferably a simple interlocking mechanism is utilized which will operate the valves in proper sequence. Such a mechanism is shown in Fig. 1 in which there is a main valve 106 which, when open, will supply air at the same time to cylinders 64 and 68. The passages to these two cylinders are so arranged that actually the clamp 56 will be closed just before there is any substantial movement of the chain and sprocket mechanism to start the bending, but the action is substantially simultaneous. The valve 108 controls the air to the pipe 110 leading to the cylinder 102. In the construction shown a single operating lever 112 operates both valves. The operating lever 112 has pivoted to it a dog 114 which engages by a cam action a nose on the end of a lever 116, the other end of which bears against the stem 118 of the valve 1.08. The lever 112 also has a projection 120 which engages the stem 122 of the valve 106. Upon downward movement of the lever 112 the lever 116 is forced over so as to momentarily open the valve 108, further downward movement of the lever 112 thereafter immediately opening the valve 106. The lever 112 is then held down until the tube bend is fully made whereupon the spring 124 lifts the lever and permits the valve 106 to close, thereby cutting ofi the power. On the upward movement of the lever 112 the dog 114 will pivot so as to slip by the nose of the lever 116 without again opening the valve 108.

The sequence of operations of the machine is as follows: The parts first occupy the position shown in Figs. 1 and 2 in which the bending former or helix segment is in a position in which the helical groove is in line with the end of the guide 40 and with the cut away side of the segment facing upward. The end of the straight tube is now pushed through the guide 40 and through the bottom of the helical groove in the segment and through the open clamp to a position fitting in the bottom groove 52 of the clamp.

The lever 112 is now pressed down and as the dog 114 passes the nose of the lever 116 the valve 108 is momentarily openend. This causes the piston in the cylinder 102 to tilt the block 98 so as to clear the pin 94. This permits the spring 104 to rotate the shaft and worm through a further 90 so as to bring the worm to substantially the position shown in Fig. 13, where is can support the tube during the entire 180 of bend. The downward movement of the lever 112 now opens the valve 106, closes the clamp 56 so as to grip the tube firmly and apply power to the cylinder 68 which swings the clamp and sweep table over and thereby bends the tube. This is the position of the parts indicated in Fig. 10. The lever 112 is now released, which causes the valve 106 to close and cuts oif the pressure to the cylinders 68 and 64. The clamp 56 is now opened by its spring 65 and the spring 86 rotates the sleeve 26in reverse direction, thereby swinging the sweep table 44 4 back to the initial position. The segmental slot in the sleeve 26 during this m ovement swings from the position shown in Fig. 10 to that shown in Fig. 11, namely through an arc of 180". However, when a reverse movement to the extent of 90 has taken place, the pin 94 has again come into engagement with the end of the block 98 which has returned to its initial position under the influence of the spring 103, thereby stopping the further return movement of the shaft 28 and worm 30, in the position with the cut away side 34 of the worm upward, as shown in Figs. ll, 12, l and 2. The tube can now be advanced as shown in Fig. 12 so as to position the partially formed coil for the formation of the next bend. In this position of the worm, the helical groove therein does not interfere with the shifting of the coil. The parts are now in the position shown in Figs. 1 and 2, ready for the beginning of the next cycle.

In this way a coil may be formedhaving as many convolutions as desired, the previously formed convolutions being supported on the sweep table 44 and carried over as each bend is made. The partially formed coil thus moved over by the sweep table is supported by the part of the table 20 along side of the lead-in guide 40, until it is pushed ahead to the Fig. 12 position when it is again supported by the sweep table. The partially formed coil is thus adequately supported at all stages in its formation so that it cannot get out of shape.

Figs. 4, 6, 7 and 8 show the form of the coil and how the successive convolutions are angularly disposed, so as to lie in close and regular formation. Fig. 6 shows that the clamp on the sweep table is not a right angles to the axis of the shaft and sleeve. This is due to the fact that the bend must be made on a slant determined by the pitch of the helical groove in the worm. In order to permit the tubing to be advanced through the end of this groove and through the clamp, the guide 40 may swing, as indicated in Fig. 6. As the bend is made and the sweep table and clamp move through the 180 angle to the position shown in Fig. 7, it will be seen that the return bend portion of the tubing will be inclined sufficiently to lay the previously formed coil along side of the portion of the tubing which is to form the next convolution.

From the foregoing it will be seen that a perfectly formed flattened helical coil is produced in which each bend is given the proper amount of twist or skew so as to lay the convolutions in close formation.

The sweep table may be made of such dimensions as to handle and support a coil of the desired number of convolutions and length. The leading end of the coil preferably projects beyond the bends so as to provide a coil-end for attachment to the piping of the apparatus in which the coil is to be used. The depressed portion or channel 36 in the table permits this projecting end to be accommodated as the second and each succeeding alternate bend is formed in the coil.

Figure 9 shows a modified form of clamp which is provided with roughened surfaces 132. This is desirable for use with helically corrugated or flanged tubing as it gives a better grip with less danger of damaging the flanges on the tubing.

While certain preferred embodiments of the invention have been illustrated and described in detail, it is to be understood that changes may be made therein and the invention embodied in other structures. It is not, there fore, the intention to limit the patent to the specific construction illustrated, but to cover the invention broadly in whatever form its principles may be utilized.

I claim:

1. In a machine for forming flattened helical coils of tubing or the like, a bending former mounted for oscillatory motion about an axis, said former having a circular portion with a helical groove therein and a flattened side, guide means for directing the tubing to be bent through said groove, an oscillatory clamp mounted in substantial alignment with said guide means on the far side of said bending former, means for operating said clamp to engage the portion of the tubing projecting beyond the bending former, means for oscillating said clamp through an angle of about 180 around said bending former so as to bend the tubing into the helical groove thereof, means for returning said clamp to initial position, and means for rotating said bending former so as to bring the flat side thereof under the bent portion of the tubing and thereby permit the bent tubing to be advanced without interference from the helical groove.

2. In a machine for forming flattened helical coils of tubing or the like, a supporting table having bearings thereon, a sleeve rotatably mounted in said bearings parallel with an edge of said table but above the level of the table, a sweep table mounted on said sleeve and having a surface substantially coincident with the surface of said supporting table and having an edge parallel with the axis of said sleeve, a shaft rotatably mounted in said sleeve, a bending former mounted on said shaft, said former having a portion concentric with the axis of said shaft and having a cut away portion at one side of said shaft, means carried by the sweep table for engaging a section of tubing extended transversely over said sweep table, means for rotating said sleeve through an angle of approximately 180 so as to swing said sweep table into a position parallel with and above said supporting table so as to bend the tubing around said bending former and means for rotating said bending former with said sweep table during the bending operation.

3. A construction as claimed in claim 2 in which means are provided for rotating the bending former with the sweep table through a part only of the return movement of the sweep table, and separate means for rotating the bending former through the balance of its return movement.

4. In a machine for forming flattened helical coils of tubing or the like, a supporting table, a bending former having its axis parallel to and above an edge of the supporting table, a sweep table normally lying substantially in the plane of the supporting table, means for pivoting said sweep table for movement about the bending former axis into a position above the supporting table, said bending former having a helical groove extending part way around the same, a grooved guide member on the supporting table for receiving the tubing to be bent, said guide lying in a plane transverse to the axis of the bending former and being so mounted that its end adjacent to the bending former has limited lateral movement, a tube clamp mounted on the sweep table and in substantial alignment with said guide when the sweep table is in its initial position, and means for swinging the sweep table and clamp over so as to bend the tubing about the bending former into a return bend.

5. A construction as claimed in claim 4 in which the bending former has a flattened side and is mounted for partial rotation about its axis.

6. In a machine for form-ing flattened helical coils of tubing or the like, a supporting table having bearings thereon, a sleeve rotatably mounted in said bearings parallel with an edge of said table but above the level of the table, a shaft rotatably mounted in said sleeve, a sweep table mounted on said sleeve and having a surface substantially coincident with the surface of said supporting table andhaving an edge parallel with the axis of said sleeve, a shaft rotatably mounted in said sleeve, a

bending former mounted on said shaft, said former having a portion substantially e.ncentric with the axis of said shaft and having a cut away portion at one side of said shaft, means carried by the sweep table for engaging a section of tubing extended transversely of said supporting table over said sweep table, means for rotating said sleeve through an angle of approximately so as to swing said sweep table and bend the tubing around said bending former, interlocking formations on the sleeve and shaft for causing said shaft and bending former to rotate with the sleeve and sweep table during the bending operation, said interlocking formations being so formed as to provide the lost motion on the return movement of the sleeve and sweep table to cause return rotation of the shaft and bending former during part only of the return movement of the sleeve and sweep table, means for arresting the return rotation of the shaft and bending former while the sleeve and the sweep table continue their return movement and means for releasing said arresting means and completing the return rotation of the shaft and bending former to initial position.

7. The method of forming a flattened helical coil of tubing or the like which comprises advancing the end of the tubing to be formed across a supporting table and into movable clamping means at one side of said table, clamping a length of tubing projecting beyond the edge of the table in said clamping means, swinging the clamping means over 180' so as to put a substantially 180 bend in the tubing, releasing the clamping means and swinging it back to its original position, advancing the tubing a distance equal to the major diameter of the flattened coil to be formed, again clamping the unbent portion of the tubing into said clamping means, swinging the clamping means through 180 to make a second 180 bend in the tubing, thereby depositing the first bent section of the tubing upon the supporting table, again releasing and returning the clamping means and advancing the partially formed coil through a distance equal to the major axis of the coil, and repeating such actions to produce a coil having the desired number of convolutions.

8. The method of forming a flattened helical coil of tubing or the like which comprises advancing the end of the tubing to be formed across a supporting table and into movable clamping means at one side of said table, clamping a length of tubing projecting beyond the edge of the table in said clamping means, swinging the clamping means over 180 around a helically grooved bending former so as to put a substantially 180 bend in the tubing, releasing the clamping means and swinging it back to its original position, partially rotating the bending former so as to clear the bent tubing from interference by the bending former, advancing the tubing a distance equal to the major diameter of the flattened coil to be formed, restoring the bending former to initial position, again clamping the unbent portion of the tubing into said clamping means, swinging the clamping means through 180 to make a second 180 bend in the tubing, thereby depositing the first bent section of the tubing upon the supporting table, again releasing the clamping means and advancing the partially formed coil through a distance equal to the major axis of the coil and repeating the cycle to produce a coil having the desired number of convolutions.

References Cited in the file of this patent UNITED STATES PATENTS 652,808 Parker July 3, 1900 690,023 Hampson Dec. 31, 1901 932,191 Trosiener Aug. 24, 1909 2,153,935 Neukirch Apr. 11, 1939 2,341,178 Duer Feb. 8, 1944 2,396,996 Frost Mar. 19, 1946 2,413,523 Shaw Dec. 31, 1946 2,474,276 Payne June 28, 1949 2,627,889 Morrison Feb. 10, 1953

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