US2282854A - Stationary induction appartus - Google Patents

Description

y 1942- H. L. DRIFTMEYER 2,282,854

. STATIONARY INDUCTION APPARATUS 2 Sheets-Sheet 1 Original Filed Sept. 28, 1959 Inventor Herbert L. Driftmegev is Attovneg May 12, 1942. H. L. DRIFTMEYER STATIONARY INDUCTION APPARATUS Original Filed Sept. 28, 1939 2 Sheets-Sheet 2-- Inventor: Herbert LDriftmeygev, b C

Hls Attorney.

tangent in the center of Patented May 1942 stares estates STATIONARY UG'EION APPARA'EUS iictzbert 1L. Drittmeyes, Fort Wayne, iinrl, assignor General New York Original application September 28, No. 290.940. Divided Electric Company, a corporation or 1939, aerial and this application June 20, 1941, Serial Neo 398,9 4!

1 Claim, 175-356) oi my copending filed September This application is a division application Serial No. 296,940, 28, 1939.

My invention relates to wound strip core sta-= tlonary induction apparatus and concerns parcore type. g

Other and further objects and advantages will become apparent as. the description proceeds. In carrying out my invention in itspreferred form, particularly in connection with stationary induction core part, flatwise spirally strip with the turns the same size and shape as they are to, have in'the finished magnetic cores, I subject the coils of strip to heat treatloops they are collapsed to form the finished magnetic cores closely embracing the winding legs. In the collapsing process the larger loops are reduced to smaller size by rotation of collapsing rollers friotionally engaging the outer surfaces of the larger loops. The two loops are the winding window and in the same tangential direction tangency (but in opposite angurotate together at the point of lar directions), thereby ing process by the frictional engagement between the two loops and by the ing to prevent either stri apparatus having two parallel facilitating the collapsthe opposite side of collapsing rollers. v

The invention will be understood more readily from the 5 considered in the winding window by the In the drawings, Fig. 1 is a perspective view of one of the wound-strip annular utilized in one embodiment of my invention. Fig. 2 is an 7 constructed in accordance with Fig. 3 is is initial step senting a step in the is cut oil. at the completion oi the coil. Fig. 6 shows the strip as it would appear if unwound from the coil and laid out flat, portions thereof which the strip chine showing another step in applying the strip to the conductive winding structure at the point where'the passed through the window 01' the winding structure. Fig. 9 is a view corresponding to the prefollowing detailed description when 2| of the strip III as well Fig. 4, a punch is brought cross-section formed than 90 degrees. circular in cross-section, but has a slightly reduced radius at the portion of the slot it on the counterclockwise side or said slot. The diiference' in radius on either side or the slot i3 is the thickness of the strip it in order that when a complete turn of strip has been wound upon the mandrel l2 there will be no bulge above the bend ii in the strip and the succeeding layers will lie flatly. substantially circularly above one another, as shown in Fig. 4. Actually the surfaces the mandrel i2 and the successive layers of strip are along a spiral having a. radius increasing an amount equal to the thickness or the strip III for each complete revolution or turn.

The strip Ill is passed through a die and cutter head It located between the reel ii and the mandrel l2. The die and cutter it has an op erating lever l1 and an internal mechanism, not shown, with three positions. In the first position, with. the lever ll perpendicular, as shown in Fig. 3, the strip may pass ireely through the head l6. By moving the lever i! to the second position it, represented by the dotted lines in such as to in Fig. 6. By moving the lever ii to the third position 20, in which the handle i! is hori'mntal, as shown in .lull lines, the strip is cut of! and simultaneously a hook 23 is punched near the end or the strip. The cut-oil terms the final end as the initial end 2'2 of the next strip ill, corresponding in shape to the initial end it, which is the end that is inserted in the slot I4 oi the mandrel l2.

The opening it is punched near the outer end of the strip by bringing the lever l1 into the position it after nearly a complete length or strip the mandrel l2. After roshort distance further. approximately two or three turns, the die operating lever ii is brought to the position so as to cut oil the strip and form the hook 23. The mandrel I2 is then rotated until all of the strip has been wound up to form the coil 24. I! desired, shoes pressing against the surfaces of the coil 24 may be employed to insure that the Alter the coil 24 formed, the end of the strip H is preferably fastoned down in some suitable manner to avoid unwinding of the strip during anneal. This may be done, if desired, by spot welding, utilizing a welding electrode 26 carried by a pivoted arm (not shown) connected to a welding transformer having the electrical circuit completed through the shoe 25. The coil is then ready to be subiected to suitable heat treatment for bringing out its best magnetic loss and magnetizing current properties. and giving the material a permanent set. It will be understood that the coil 24 has the turns of the same size and shape as the core of the completed induction apparatus. It will also be understood that the mandrel I2 is so constructed that the coil 24 may be slipped off endwise.

In order to transfer the strip material from the coils, such as the coil 24, to a conductive winding, a pair of coils is placed on driving spindles adapted to engage the bent ends ll, as shown in Fig. 7. A conductive winding structure 21 is placed between a pair of such coils, only one against a die block, out a rectangular opening it, as shown hasbeen and it will have more oneness of which is shown in Fig. 7. and the outer ends of the coils are unfastened so that they may be opening or window 29 01' slipped through the the conductive winding structure 21. The outer end 2! o! the strip I0 is brought around and astened to the next underlying layer 01 strip to form a larger loop 3B. The fastening may be accomplished through the opening I9- and pulling the strip back tightly so as to cause the hook 215 to grasp the material at the edge 3| of the opening 59. The spindle 85 is rotated to force rotation of the coil 23 and the larger loop 30, and consequently causes transference of the material from the outside of the coil 24 to the inside of the larger loop 30. The rotation of the drive spindles 35 is continued until substantially all of the material has been transferred to the larger loops 30. as shown in Fig. 8, whereupon the drive spindles 35 are removed. The inner cent ends it of the strip are placed in suitable recesses in the winding legs 32'. For example, in the case of a cruciform section coil the bent ends it may be caused to 00-- cupy the corner 32' between the high and low voltage windings. The process as carried out in the foregoing manner avoids any possibility of bending the strip material so far as to strain it beyond the to the original size and shape of turn so that it will be free from elastic strains favorable magnetic properties.

The transformer and reactor assembling machine comprises a table (not shown), a pair or turn tables (not shown) for supporting and drivingthe coils of strip 24 of Figs. 1 and 4, a pair 0! core-driving spindles 35, one of which is shown partially in section in Fig. '7, adapted to fit into sockets in the turn tables, a driving motor (not shown) arranged to rotate the turn tables and spindles 35, a pair of idling pressure rollers 31 (one shown) for holding the strip in the coils 24 until unwound, two pairs of collapsing rollers 38 for quickly collapsing the larger loops when cornpleted, and a suitable clamping arrangement (not shown) for holding the conductive-winding structure 21 while the core strip material is being applied.

A collar 51 is provided on the upper portion of the spindle 35 in order to serve as a guide for the strip on the coil 24 as the coil 24 is being unwound. A set screw 58 may be provided for ad- ;iustably securing the collar 51 at the proper height for the width of strip in the coil 24.

For receiving the end ii of the magnetic strip and releasing it at the proper time, a self-opening slot 59 (see Fig. 7) is provided in the drive spindie 35. This sell-opening slot 59 is formed by cutting a sector longitudinally out or the portion 56 of the spindle $5 and providing a pivoted latch with a pivot axis 6! parallel with the axis of the spindle 35, but of! center. The

latch 80 is adapted to lie against edge 6| of the sector cut into the spindle portion 56. However, it has a portion 82 which is out back sufllciently to form the self-opening slot 59. The outer tip, or nose 62' of the latch 60 extends lengthwise in the sector-shaped opening of the spindle portion 58, and is carried by two arms 63 through which pass the pivot pins ii of the latch 50. The arms 53 are at the upper and lower ends of the lengthwise extending tip portion 62 and occupy transverse slots or recesses 63' in the spindle 85. To permit the latch ti 82' to swing away from quickly by drawing the hook 23 elastic limit and permits bringing the material back strip material in are mounted on driving-spindles 35 and the latter are rotated. The coils are mounted upon the spindles 35 by moving the pivoted latch 60 into the position shown in Fig. 7 and the spindles are placed through the openings or windows 86 in the coils 24 with the bent inner ends l3 of the coils inserted in the slots 59 in the driving spindie 35.

the strip the linear speed of the adjacent portions of strip in the coil 24 in the larger loop 30 to remain approximately the same, so that the coil 24 and the loop 30 remain tangent and the strip will feed' smoothly from the coil 24 to the inside of the loop 39. The two coils 2 1 are so placed on the turn tables 34 that they unwind by being The pressure of the rollers 31 causes rotated in opposite directions.

Owing to the fact that the latch 80 is pivoted off center it cannot be rotated away from the position shown in Fig. 7 without pressing against the inner surface of the coil 24. Just so long ,as the strip remains coiled in the form oi. the coil to be unwound uniformly and causes lapsing completely as nent set which the material has acquired in the heat treatment. The outer ends of the strip are then unfastened and the bent inner ends I4 are positioned in recesses in the winding legs 32. It will be understood that friction of the strip upon the supporting table prevents the strip from colits permanent set would otherwise cause it to do. The driving rollers 38 are moved into frictional contact with the magnetic strip, rotating the loops 30 and collapsing them to the size and shape shown in Fig. 10.

Since each loop exerts substantially the same pressure as the other at the point of tangency 98, the strip is kept approximately at the middle of the winding window 29 so as to minimize the possibility of scraping of the strip material on the conductive winding structure. The frlctiona] contact at the point 98 also helps to keep the outer layers of both loops 30 in rotation. The directions of rotation are opposite so as to have the some linear direction. of motion of the strip at the point of tangency 98. Although the permanent set of the material tends to keep itin the shape shown in Fig. 18, it may be advantageous to secure the outer ends 2| of the strip to the next adjacent lower layer in some suitable manner as by means of spot welds 99. When 24, the latch Bil is held in place, the bent and of the strip 96 is held in the slot. 59 and the driven spindle produces positive drive of the coil 24 and causes it to rotate and unwind into the larger loop 30, which is in turn caused to rotate thereby. After nearly all of the strip has wound into the larger loop so that there is no longer a complete turn of strip on the spindle portion 56, as shown in Fig. 8, the pivoted latch 69 is released permitting the slot 53 to open up. Thus, the bent inner end it leased and springs out as a result of the rotation of the spindle 85. This makes it unnecemary to stop the driving motor at the precise moment that the inner turn of coil 2d starts to unwind, and prevents the being broken of their sockets whereupon the the larger loops at collapses to the position shown in Fig. 9 due to the permaof the strip is re? it is desired to disassemble a transformer or reactor, i. e. to remove the core, the entire procedure explained in the foregoing description is reversed with the directions of rotation of the rollers and shafts reversed.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the'United States is:

A flatwisespirally wound coil of strip hav n a tab punched at the end thereof to form a hook and having a slot punched in the strip a short distance from the end of the strip, adapted to receive the said hook for securing the outer turns of the coil in a larger loop when the outer turns of the coil are unwound.

HERBERT DRIF'IMEYER.

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