US3281916A

US3281916A - Apparatus for making electrical winding assemblies

Info

Publication number: US3281916A
Application number: US211929A
Authority: US
Inventors: Goldsmith Bernard Morton
Original assignee: Nytronics Inc
Current assignee: Nytronics Inc
Priority date: 1962-07-11
Filing date: 1962-07-11
Publication date: 1966-11-01
Anticipated expiration: 1983-11-01

Description

3,281,916 APPARATUS FOR MAKING ELECTRICAL WINDING ASSEMBLIES Original Filed April 10, 1958 Nov. 1, 196 B. M. GOLDSMITH 5 Sheets-Sheet 1 FIG. 2. FIG.

Nov. 1, 1966 B. M. GOLDSMITH APPARATUS FOR MAKING ELECTRICAL WINDING ASSEMBLIES Original Filed April 10, l958 5 Sheets-Sheet 2 PEG. 9.

ATTORNEY5 Nov. 1, 1966 B. M. GOLDSMITH 3,231,916

APPARATUS FOR MAKING ELECTRICAL WINDING ASSEMBLIES Original Filed April 10, 1958 5 Sheets-Sheet 5 FIG. I4.

l I P/CK-l/P Mandre] Align/nan Z L Tube 4 CASING TRANfiFER Alignment MANDREL POS/T/O/V/NG POI? C/45/N6 PICK-UP Down Up Wl/VD/A/G WIRE FEED 0ur 51.55% P05/770/V/N6 45/10 BEND ca/L Wl/VO RAISE/L OWEA W/RE rue/5:405? I 2'! L 5140 FOE/WEI? POSITION/N6 curon LEAD L 2 LEAD BEND Advance -l?etracf C RSI/V6 POS/ T ON/NG "AA/60L AR CAPP/N6LEADP0$/ r/o/w/va ".9 UP /1. CASING P05/770N/N6 (oawu-z/ P 1 CAP TEANEFE/P ABM 1 1.540

ST/FA/GHTEN/NG BAEJ (Ml-007) m. PUSH (/P CAP INTO CHS'l/VG I1. CASING LOWER? ONTO JWAG/NG TOOL p. /NDEX INVENTOR BEEN/4R0 M 60LD5M/7'H ATTORNEYS United States Patent 3,281,916 APPARATUS FOR MAKING ELECTRICAL WINDING ASSEMBLIES Bernard Morton Goldsmith, Westfield, N.J., assignor to Nytronics, Inc., Phillipsburg, N.J., a corporation of New Jersey Continuation of application Ser. No. 727,612, Apr. 10, 1958. This application July 11, 1962, Ser. No. 211,929 18 Claims. (Cl. 29-33) This invention relates to automatic machinery, and to methods for making miniature inductors and transformers of the cylindrical type. This application is a continuation of my copending application Serial No. 727,612, filed April 10, 1958, now abandoned.

Inductors and transformers of the cylindrical type have found extensive use, particularly in the radio and television fields where slug-tuning is employed.

For many years, and in fact, even to date, cylindrical inductors are made largely by hand. Hand labor is expensive, and now, with the trend toward miniaturization, such inductors are even more difiicult to fabricate.

Although automatic machinery has been developed for making toroidal coils, this machinery does not lend itself for making cylindrical inductive components.

Accordingly, it is an object of this invention to provide automatic machinery for making miniature inductors and transformers of the cylindrical type and, in particular, inductors and transformers of the type described and claimed in Goldsmith Patent No. 2,836,805, granted March 27, 1958.

It is a specific object to meet the above object with a multiple-station indexing-type machine wherein the different basic operations take place simultaneously and in synchronism on different work pieces at different stations, so that with each indexing cycle a newly completed article is delivered by the machine.

In order to understand the operation of the machine, it is of course desirable to have some knowledge of the article to be produced.

Briefly, the article comprises a cylindrical (or substantially cylindrical) casing having a double wall. The outside surface of the inner wall constitutes a coil form, and the inside surface defines an axial bore through the casing, the space between the walls being open at one end and closed at the other. A first winding is positioned between the walls, preferably frictionally engaged to the inner wall, and if a transformer is desired, a second winding is positioned over and frictionally retained by the first winding. The space between the Walls at the open end is closed by a plastic insulator cap and the end of the inner wall is formed over the insulator cap, securing it in place.

In accordance with a first aspect of the invention, there is provided a machine for making an encapsulated inductor, comprising means for forming a cylindrical coil having lead wires, the lead wires extending in the same direction and parallel to the axis of the coil, means for mounting the coil in the space between the walls with the lead wires extending through the open end of the cylinder, and means for applying insulated sealing means to the open end of the cylinder.

In accordance with another aspect of the invention, the machine comprises a plurality of work holders, each having means fitting tightly into the bore of a casing for supporting the casing during subsequent operations. Means are provided for forming a coil with integral leadout wires extending parallel to the axis thereof, and in the same direction. Additional means are provided for positioning the coil between the walls, with the lead wires extending from the open end of the casing. The space between the Walls is then closed at the open end by a 3,281,916 Patented Nov. 1, 1966 preformed insulated cap. The shape of the cap corresponds to the end profile of the space between the walls, and includes slots for properly locating the lead-out wires. A cap-installing device forces the cap into the space Within the walls, a short distance from the ends thereof. A forming tool then forms the end of the inner wall over the cap, to secure it in place. Finally, means are provided for disengaging the article from the work holder.

If a transformer is desired, further means are provided for forming a second coil and positioning it over the first coil.

In accordance with still another aspect of the invention, there is provided a multi-station machine, comprising a rotatable carrier and a plurality of work holders mounted on the carrier at spaced positions therearound, each holder comprising means for supporting a cylinder. A mechanism is provided at a first station for transport ing the cylinders to a position where respective cylinders are picked up by successive holders. The cylinders are transported to a second station where a coil former is provided for winding a coil having lead wires extending in the same direction and parallel to the axis of the coil. The coil is mounted in the space between the walls, the lead wires extending through the open end of the cylinder. The cylinder is then transported to a third station where sealing means is applied to the open end of the cylinder. This aspect of the invention is characterized by indexing means controlling the rotation of the carrier so that the operations at the respective stations are effected simultaneously and in sychronism on the different work pieces, whereby with each indexing cycle, an encapsulated inductor is produced by the machine.

Other functions may be provided at the several stations in addition to those already described. For example, at the coil winding stations, the casings may be axially rotated so that the lead-out wires of the windings extend from the casing at predetermined locations.

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the acc'ompaying drawings, wherein:

FIG. 1 is a perspective view of an automatic multiplestation indexing-type machine of the character indicated;

FIGS. 2, 3 and 4 are cross-sectional views of the article during three different stages of assembly;

FIG. 5 is a detailed perspective view of the first station showing the mechanism for delivering the casing to a work holder;

FIGS. 6, 7, 9 and 10 are detailed views of mechanism at the second and third stations where coils are formed and inserted into the casing;

FIG. 8 is a diagrammatic view of a cam and gear arrangement for controlling essential mechanical movements at the second and third stations;

FIG. 11 is an exploded perspective view of mechanism at the fourth or capping station;

FIG. 12 is a detailed partial view of swaging mechanism at the fifth station;

FIG. 13 shows a piece counter and a tool for disengaging the completed article from the workholder; and

FIG. 14 is a program chart showing the relative timing of the several operations, for a single automatic cycle of operation of the machine.

Referring first to FIG. 1, the machine essentially comprises a rotatably indexed horizontal table I, carrying a plurality of workholders 2, spaced equally about a central indexing axis. The table is mounted on an indexingdrive shaft (not shown) and is driven by motor-operated indexing mechanism, which in the drawing is concealed by other parts. Indexed rotation of the table may be governed by programming means, suggested at curve p of FIG. 14 and effective during the last part of the machine cycle. The specific means for controlling the operation of the cams will be understood to be conventional, so that it need not be described herein.

Preformed casings 4, made of insulating material, preferably nylon, are fed from a hopper (not shown) int-o a vertical feed tube 5; one such casing is shown in cross section in FIGS. 2, 3 and 4. The casing is in the shape of an annular cup or double-walled cylinder, the outer wall 6 and the inner wall 7 being closed at one end 8 and open at the other; the axial depth of the coilreceiving space in the casing may be specific to the intended length of coil to be received therein, but a generalized casing 4 is shown wherein a plug or insert 3 (preassernbled to the casing) defines the correct coil-insertion stop position. The inner wall 7 constitutes a coil form, and the space within the inner wall defines an axial bore 9 into which a ferro-magnetic core (e.g. of ferrite) is subsequently threaded. The outer wall 6 is formed with a key projection 10, extending longitudinally along the surface of the wall, said key 10 serving to facilitate later handling, as when automatically assembling the finished article into a printed circuit. The feed tube is provided with an elongated slot 11, which accommodates the projection 10. The casings, therefore, are all oriented in a given position as they leave the feed tube 5.

The tube 5 is supported by a cylindrical frame 12 which is attached to a post 13, fixedly mounted on a general framework 14 of the machine.

The casings are applied to the feed tube 5 with the open end facing down and are gravity fed to a worktransfer arm or table 15 (FIG. 5). The transfer arm 15 operates in synchronism with the index cycle of the machine, and it carries each casing 4 successively to a position where one of the work holders 2 picks it up and moves it to another station; curve a of FIG. 14 suggests that the work-transfer operation (from feed-tube alignment to work-holder alignment) occurs in the central part of the index cycle at the first station. The table 15 is sector-shaped and is pivot-ally mounted at the central angle end on a pivot rod 16. The rod 16 is driven by a lever 17 (only partially shown for simplicity) which imparts pivotal motion to the table 15, as in accordance with the program of FIG. 14a. A keyed recess or counterbore 18, conforming in shape to the external profile of the casing, is formed in the table top. The slot 18 is so located that when the table 15 is in a receiving position, the lowermost casing 4 registers with and falls into the slot. The slot depth (to a retaining lug or shoulder, not shown) is approximately equal to the casing height so that the deposited casing is flush with the table top. The table is then pivoted to a delivery or pick-up position (the position illustrated in FIG. 5) where the casing is picked up by a workholder 2.

The workholder, as best seen in FIG. 5, comprises a C-shaped bracket 19, the base of which is affixed to the indexed table 1. A mandrel 20 is freely mounted through holes at opposite ends of the C-shaped bracket. The lower end of the mandrel 20 passes through and extends a given distance below the table 1. The mandrel, axially movable, is urged in an upward position by a coil spring 21 mounted around the mandrel between the top of the bracket 19, and a stop block 22, the stop block being rigidly attached to the end of the mandrel. The opposite ends of the spring 21 are secured to the mandrel and stop block respectively, to urge the mandrel counterclockwise as well as in the upward direction.

The mandrel is limited in its counterclockwise rotation by a fixed stop 23, which may be attached to the rear of the bracket 19, contacting a roller 24. The roller 24 is carried by a rod which passes through the block 22 and is secured thereto. In place of the rod 25, a stud (roller 24) may be secured in one end of the block and a boss secured to the opposite end of the block, the stud and boss forming a T with the mandrel.

The upward and downward movements of the mandrel are limited by a block 25 mounted between the ends of bracket 19. The mandrel passes through the block 26 and is rigidly attached thereto. A roller 27 is carried by the block 26 and serves to communicate an axial driving force to the mandrel. As shown in FIG. 5, whenthe casin -transfer table or arm 15 is in the pickup position, an angle bar 28, overlying the roller 27, is urged downwardly against the roller by conventional means, not shown, causing the mandrel to move downwardly into the bore 9 of the casing. The mandrel engages the bore 9 with a tight fit (limited, if desired, by a stop pin 20', see FIG. 12) so that, when the mandrel is retracted, the casing is carried with it. Since the spring 21 urges the mandrel in the upward position, the mandrel is returned to this position simply by moving the angle bar 28 upwardly. Thus, at the first station, the workholder picks up a casing with the open space between the walls facing down.

It should now be apparent that the efficiency of the machine is largely a function of proper timing. For example, the table 15 shoud be at the delivery position (as shown in 'FIG. 5) at the same time that the mandrel 20 is ready to pick up the casing; this relationship is illustrated by curve b of FIG. 14, which covers the depression of arm 28 (and therefore of mandrel 20) in synchronism with delivery of a new casing 4 to the position shown in FIG. 5.

On the way to the second station, the casing, carried below the table 1, contacts an interlock switch 29. In the absence of a casing, the switch operates to cut-off the power to the machine, in order to prevent a free mandrel from moving onto the next station.

At the second station, mechanism is provided to wind wire into the shape of a coil and to insert the coil into the casing. This station is shown generally at 30 in FIG. 1, and in detail in FIGS. 6-10.

Referring first to FIG. 6, insulated wire 31 (e.g. enamelcoated, copper-sheathed steel wire) is paid-out from a spool (not shown) through a pair of friction rollers 32 driven by meshing feed gears 33. The gears 33 preferably have one-way engagement to their respective friction rollers 32, engagement being in the feed direction to drive the wire in the feed direction, shown by an arrow; wire feed-out is governed by a crank 33 driving the shaft for the lower feed gear 33, and the length of initial wire feed-out is determined by the adjusted position of connection of a drive rod 33 to the crank 33', the timing of feed-out being suggested at curve 0 of FIG. 14. The wire is then passed through a threading block 34 which threads the wire in a coil former, shown generally at 35. The wire is sufficiently stitf so that as it leaves the threading block 34, it has no tendency to droop, it being noted that '(as set forth in said Goldsmith application), the wire ends of the machine product provide not only electrical lead connections, but also substantial mounting support for the product.

The coil former 35, mounted in front of the threading block 34, comprises a rotatable spindle 36 and a sleeve 37 axially slidable on the spindle. The sleeve 37 is segmented by :a pair of slots 38, aligned to pass the fed-out wire end tangentially of the spindle 36. The sleeve is positioned so that the wire served by the threading block passes through the aligned slots 38 between a pin 39 mounted to the inside of the sleeve, facing the spindle, and an oppositely disposed offset lug 40, mounted on the spindle. The purpose of the sleeve, pin and lug is to form a first axially directed lead-out wire for the coil. After a predetermined length of wire is served by the threading block, the sleeve is moved downwardly, relative to the spindle, by a lever 41 connected to an enlarged portion of the sleeve; the timing of lever 41 is suggested at curve d of FIG. 14. The pin 39 is ofiset forward of the lug 40 so that, as shown in FIG. 7, the end of the wire is bent perpendicular to its original direction; in FIG. 7, 39 and 39" suggest upper and lower positions of pin 39 in relation to the wire feed-out elevation, bending being accomplished once pin 3d strikes and then continues to ride on the projecting wire end, as will be understood. The sleeve is moved down sufficiently to be out of the path of the wire. The spindle 36 is then rotated clockwise so that, as the winding development proceeds, the lug 4t] anchors the wire at one end to the spindle.

As the spindle is rotating, forming turns in the wire, the entire wire-feed mechanism, including the threading block '34 and friction rollers 32, all carried by a vertically movable support means 34', is moved gradually upwardly to give the correct pitch to the wire. The threading block and rollers and support means 34, are mounted on a frame-based parallelogram-type suspension, two opposed tie rods 42 of which are shown. The suspension system is raised and lowered by a crown cam 43 driving a cam follower 44 carried by the wire feed-out support means 34.

Coordination between rotation of the spindle 36 and that of crown cam 43 is controlled by a drive mechanism shown in FIG. 8. The mechanism comprises a main continously running drive shaft 45 for variably positioning an eccentrically mounted roll or cam 46. The cam 46 bears against an idler roller 47 carried by an arm 48. The arm 48 is movable about a fixed pivot 4-9, and controls the movement of a connecting rod 50; spring means (not shown) constantly urges arm '48 counterclockwise in the sense of FIG. 8. One end of the connecting rod 50 is terminated in a follower nut threaded on a lead screw 51 which extends lengthwise of the arm 48, whereby the oscillated throw of rod 50 may be selectively adjusted. The other end of the rod 50 is rotatably connected to a gear 52. Thus, rotation of the main drive shaft 45 results in partial rotation of the gear 52. The gear 52 drives the crown cam 43 over a shaft 53, to which the gear and cam are fixed. Gear 52 also drives a gear 54 over a pinion 55, and, in turn, gear 54 rotates the win-ding spindle 36 over a gear 56. The number of revolutions made by the winding spindle 36 (as well as the total elevation of the wire feed-out support means 34) for each revolution of the eccentric roller 46 may be adjusted by selectively positioning the connecting rod 50 on the lead screw 51, as will be understood. The timing of these functions at the second station is suggested at curves e and f of FIG. 14.

Immediately after the coil is formed, a second lead former 57 (FIGS. 6 and 9) is elfective to bend the remaining wire end in the same direction as the first lead wire. The second lead former comprises a block having an arcuate surface 58, corresponding in shape to the surface of the coil; the contoured surface 58 terminates in a retaining or locating shoulder 59. When the former 57 is brought into posit-ion (see FIG. 14g), the coil rests against the arcuate surface 53, the last coil turn being in underlying contact with the shoulder 59. The lead is formed mechanically, in a manner similar to the formation of the first lead. A lug 6! is mounted on the former 57, directly under the extending wire, and a pin 61 is mounted above the wire on a vertically movable leadformer arm 62. The former arm 62 is movable in a direction parallel to the axis of the coil, and is spring urged upwardly. The pin 61 is olfset both above and forward of the lug 60 by approximately the thickness of the wire, whereby the wire is located between the lug 60 and the pin 61 when the lead former is in unactuated position.

Immediately after the lead former is positioned, the wire is cut at the front face of the threading block 34 by a wire cutter 63 comprising a knife blade 63' and an L-shaped angle member. The base of the L-shaped member extends toward the lead former 57 and is positioned a given distance above the former arm 62 when the former is in unactuated position (solid outlines in FIG. 6). The cutting edge 63' of the knife blade is positioned below the base of the L by an amount slightly more than the distance between the base and the former arm 62. Thus, the initial movement of the cutter 63 in the downward direction causes the knife blade to sever the wire. Continued movement causes the base of the L-shaped arm to bear against and move the former arm 62 downwardly, thus driving pin 61 to bend the cut end of the wire around the lug 60 to the axially directed position shown in FIG. 9.

The wire cutter 63 is operated by a bell-crank 64 which, for example, may be driven by a solenoid 65. The solenoid may be operated by a switch (not shown) actuated when the drive mechanism arm 48 (FIG. 8) reaches a given position, or by a wiper attached at a given location on the gear 54, as will be understood.

The return stroke of the solenoid armature retracts the wire cutter 63, and the former arm 62 (under spring tension) is returned to its original position.

The coil, as shown in the lower part of FIG. 2, is now completely formed and is ready to be inserted into the casing 4.

The programming of the cams to wind a coil has been generally described in connection with FIG. 14, the applicable cams being grouped under the caption Winding." The first mechanical movement is the paying-out and threading of the wire in the sleeve. This operation, shown .at curve 0, takes place during the time between 30 and 60. When the wire comes to rest in the feed-out position, the sleeve is moved downwardly (curve d) to produce the first lead-out wire. The sleeve remains in the down position during the formation of the coil. The spindle is then rotated, causing the wire to wind therearound (curve e) while the threading block is gradually raised (curve to produce the correct pitch or lead in the turns. Shortly before the last winding of the coil is formed, the second lead former starts to move towards its final position (curve g). The timing is adjusted so that the former arrives in position with the winding of the last turn. The cutter is then lowered (curve h), first cutting the wire at the face of the threading block and then bending the second lead.

It will become clear from the following discussion that it is essential for the coil to be inserted into the casing with the lead out wires emerging from predetermined angular locations at the bottom of the casing (i.e. accurately referenced with respect to key 10). To achieve this or some other specified positioning, the casing may be axially rotated a predetermined angle before receiving the coil.

In FIG. 10, a rack 66 and pinion 67 are shown for rotating the mandrel 20 which carries the casing 4. The rack 66 is slidably driven on a track 68. As previously mentioned, the mandrel is normally urged in one extreme angular position by the spring 21. This extreme position is determined by the stop '23 preventing further counterclockwise rotation of the stud 24, to which the mandrel is fixed. The pinion 67 i fixed to a shaft 69 which shaft is attached to one end of a bracket 70, the shaft and bracket being in the form of an L-shaped connecting rod. A finger 71, attached to the opposite end of the bracket 70, acts on the rod 25 to rotate the mandrel. Thus, movement of the rack in the direction of the arrow causes clockwise movement of the finger '71, which movement is communicated to the mandrel 20.

After the casing is rotated to the desired angular position, the mandrel is lowered to a position directly above the spindle 36, the inner wall 7 of the casing being coextensive with the wall of the spindle. The sleeve 37 is then urged upwardly. The upper end of a neck portion 72 of the sleeve (FIG. 6) forces the coil off the spindle and into the casing around the inner wall 7, and against the plug or limit stop 3, as shown in FIG. 3. The inside diameter of the coil is such as to frictionally hug the wall or coil-form portion 7.

The cam programming for angularly positioning the casing and inserting the coil into the casing is shown in FIG. 14, at curves i and j, respectively, under the Winding operations.

The mandrel containing the casing loaded with a first coil is then retracted and moved to a second coil-forming station, being the third station in the overall fabrication of the final article; this second coil-forming station is used only if the final article is a transformer. Coil-forming operations at the third station are the same as at the first coil-forming station, except that the winding spindle for the second coil-winding operation must be of a sufficiently large diameter than spindle 36 to assure axial overlap of the second winding on the first winding. Also, the casing is rotated to a different position before receiving the coil; this is to position the lead wires of the second coil so that they emerge from the casing at angularly spaced locations relative to the lead wires of the first coil. The four lead-wire locations may define four corners of a rectangle.

As best seen in FIGS. 3 and 4, the second lead wire of the first coil is spaced from the body of the coil, so that the second coil may be nested over the first coil, inside the second lead wire.

It will be understood that the second coil is required only if a transformer is being fabricated. If an inductor is desired, the casing, upon receiving one coil, by-passes the second coil-forming station.

The coil-loaded casing is next carried to a capping station (FIG. 11) where an annular insulated cap 73 (having a locating key to register with the casing key is wedged into the bottom of the casing in the space between the walls 6 and 7.

Referring to FIG. 11, three plates 74-75-76 are shown in an exploded view. Actually, the upper and intermediate plates are contiguous cams, and the lower plate 74 is separated from the intermediate plate 75 by the thickness of a cap.

The capping mechanism, which serves the dual function of straightening and accurately spacing the two or four lead-out wires, as the case may be, comprises the two cams 75-76, plate 74, a feed tube 77 (for caps), a cap-transfer arm 78 and a cap elevator 79 (see also FIG. 4). The caps 73 are supplied to the feed tube 77 by a hopper (not shown). The feed tube 77 includes a slot for the projecting key portion of the cap, so that the caps are oriented in the tube. The caps, properly oriented, are fed onto the surface of the plate 74 and into a recess 80 in the transfer arm 78. The transfer arm 78 reciprocates to carry the new cap to a central location (defined by locating stop 80'), returning to its original position for another cap, as controlled in accordance with curve I of FIG. 14. In its normal unactuated position, the cap transfer arm 78 closes a limit switch 81 serving a safety-interlock function to apply and maintain power to the program camshaft. As shown, the arm 78 is normally urged by a spring 82 into a position to receive a cap, and is driven by a shaft 83 to carry the cap to the center of the cam 74.

At the center of the cam 74, a circular hole is formed to provide space for axial movement of the elevator 79. The stop 80' serves to position the cap over the elevator.

As best seen in FIG. 4, the cap 73 includes peripheral slots 84 through which the lead wires pass. Since these slots are of the same size or are only slightly larger than the diameter of the lead wires, it is essential that the wires by straight and accurately positioned before the cap is elevated to the casing. Accordingly, the mandrel carrying the wire-loaded casing is lowered so that the lead wires extend into a hole 85 provided in the lower cam plate 75. Two pairs of oppositely disposed straightening bars 86-87 and 88-89 are slidably mounted in grooves provided in the cam 75. The ends of the bars are chamfered, and the four leads are initially positioned between adjacent chamfered corners, respectively.

The elevator 79 is also best seen in FIG. 4 and simply comprises a rod for supporting the cap and a narrowed centering portion for fitting into the center hole of the cap.

The straightening bars are driven by the transfer arm 78 via a pin passing through an arcuately shaped slot 91 in cam 75 and into a linear slot 92 in the cam 76. Follower pins 93, provided on the top of each of the straightening bars, ride in cam slots 94 in the cam 76.

The straightening bars are moved radially inwardly by the movement of the cap-transfer arm 78, while arm 78 is in the further act of carrying a new cap to the center of the :plate 74. The pin 90 rides idly in slot 91 of cam 75, but drives the cam 76 in the direction shown by the arrow. Rotation of this cam causes the pins 93, and thus the straightening bars, to move radially towards the center. This action straightens and properly spaces the lead wires. Return of the cap-transfer arm moves the straightening bars from the hole 85, and the cap elevator 79 (FIG. 4) is then raised to force the cap into the bottom of the casing. The cam programming for the capping and lead-positioning operations is shown under that heading in FIG. 14, at curves k, l, m, respectively.

The mandrel carrying the wide-loaded casing, closed at both ends, is then retracted and moved to the fifth station, where the inner wall is swaged over the cap, permanently securing it in place.

At the swaging station, FIG. 12, the mandrel 20 is lowered over a rotary driven swaging tool 95. The working surface of the swaging tool is generally conical and of suflicient diameter to roll over the edge of the innner wall 7. The swaging tool is rotated at a high speed to cause the edge of the wall to become plastic as a result of the frictional heat, and upon cooling to remain permanently deformed, thus permanently retaining the parts in assembled relation.

The casing is lowered against the swaging tool until the outer wall of the casing contacts a limit switch 96. Operation of this switch causes the mandrel to be withdrawn, and the article is now completed.

The cam programming for this operation is shown under Swaging (curve n) in FIG. 14.

Upon the next indexing of the work-supporting table 1, the mandrel 20 carrying the completed article is disengaged from the mandrel. This last operation is shown in FIG. 13. The table 1 carries the mandrel 20 into the path of a work-piece counter 97 and between a pair of fixed cam fingers 98. If a stop pin 20' is employed to axially locate casing 4 on mandrel 20, then it will be understood that the angular location of pin 20' is such as to avoid interference with fingers 98 when mandrel 20 is in its normal angular position (determined by contact at 23-24, FIG. 5). The counter 97 is of the contact type; each time a casing contacts the counter arm, the counter records another finished piece.

The fingers 98 are spaced apart to permit the mandrel 20 to pass therebetween. The fingers are wedge-shaped and disposed so that the narrow part of the Wedge first makes contact with the casing. As the mandrel passes through the fingers, the top of the casing rides along the lower edges of the fingers which effectively cam the casing off the mandrel. A receptacle (not shown) is provided under the fingers for receiving the article as it leaves the mandrel, thus completing automatic fabrication of the article.

It will thus be seen that the machine of the invention provides a substantial advance in the art of manufacturing electrical inductors and transformers. As compared with the products of prior methods (extensive manual labor), the products of the new machine exhibit superior electrical performance and, because tolerances can be closely held, the products are much more closely consistent in their electrical properties. The machine lends itself to the fabrication of inductors, chokes and transformers by simple set-up change, and wide latitude is available for selection of turns per winding and, therefore, of turns ratio for transformer windings. In a typical op- 9 eration of the machine, finished encapsulated inductors or transformers (exemplified by said Goldsmith application) are delivered by the machine at a rate of 35 to 40 per minute, and savings in fabrication costs in excess of 50 percent are realized over prior methods.

While the principles of the invention have been described in detail in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention as defined in the accompanying claims.

What is claimed is:

1. An automatic machine for making an encapsulated inductor, the capsule being initially an open ended, double walled insulated cylinder, the machine comprising means for forming a cylindrical coil having lead wires, the lead wires extending in the same direction and parallel to the axis of the coil, means for mounting the coil in the space between said Walls with the lead wires extending through the open end of the cylinder, and means for applying insulated sealing means to the open end of the cylinder with the lead wires extending therethrough, thereby completely enclosing said coil between the double walls.

2. The machine according to claim 1 and comprising further means for forming a second coil having lead out wires, and means for inserting said second coil in the space between said walls, the diameter of said second coil being such that the coil frictionally engages said first coil.

3. The machine according to claim 1, wherein said insulated sealing means comprises a cap, the shape of said cap being similar to the configuration of the space between the double walls, and including slots for the lead wires, said sealing applying means inserting said cap into said space and within said double walls, the lead wires extending through said slots and means for deforming the end of the inner Wall over said cap, thereby securing said cap in place.

4. The machine according to claim 1, wherein the space within the inner wall defines a bore through the capsule, and further comprising a mandrel for fitting tightly into said bore for supporting said capsule during subsequent operations, and means for disengaging the capsule from said mandrel when the article is completed.

5. A machine for making automatically an encapsulated miniature inductor, the capsule being initially an open ended double walled insulated cylinder, the inner wall constituting a coil form and the space within the inner Wall defining an axial bore through the cylinder, the machine comprising a plurality of workholders, each of said workholders having means for fitting tightly into the bore of a cylinder, for supporting the cylinder during subsequent operations, means for forming a coil having lead wires extending in the same direction and parallel to the axis of the coil, the inside diameter of the coil being slightly less than the coil form diameter, means for forcing said coil over said coil form with the lead wires extending from the open end of said cylinder, means for installing a preformed insulated cap, having slots for 10- cating the lead wires, into the space between said walls, at a given distance from the end of the inner wall, means for deforming the end of said inner wall over said cap thereby securing the cap in place, and means for disengaging the encapsulated inductor from said workholder.

6. The machine according to claim 5, and comprising further means for forming a second coil having lead wires extending in the same direction and parallel to the axis of the coil, the inside diameter of the second coil being slightly less than the outside diameter of said first coil, and means for forcing said second coil over said first coil, thereby forming a transformer.

7. A multi-station automatic machine for making an encapsulated inductor, the capsule being initially an open ended, double walled insulated cylinder, the machine comprising a rotatable carrier, a plurality of work holders mounted on said carrier at spaced positions therearound, each holder comprising means for supporting a cylinder, means at a first station for transporting said cylinder to a position where the respective cylinders are picked up by successive holders, means at a second sta tion for winding a coil having lead wires extending in the same direction and parallel to the axis of the coil, means for mounting said coil in the space between said walls, the lead wires extending through the open end of the cylinder, means at a third station for applying insulated sealing means to the open end of the cylinder with the lead wires extending therethrough, means for rotating said carrier so that the workholders pass successively through each of said stations, and means for indexing said rotating means so that the operations at the respective stations are effected simultaneously and in synchronism on the different workpieces, whereby with each indexing cycle, an encapsulated inductor is produced by the machine.

3. The machine according to claim 7, wherein said capsule includes a keyed projection on the surface thereof for orientation during subsequent operations, said first station further comprising a vertically disposed feed tube for said capsules, said tube including a longitudinally extending slot in the surface thereof adapted to accommodate the keyed projections on said capsule, whereby as the capsules leave said feed tube they are axially oriented in relation to said keyed projection.

9. The machine according to claim 8, wherein said transporting means at said first station comprises a pivotal arm underlying said feed tube, a slot in the surface of said arm corresponding tothe end profile of said cylintler, means under control of said indexing means for pivoting said arm so that the cylinder is moved to said position where it is picked up by a workholder.

10. The machine according to claim 7 and comprising further means for forming a second coil having lead out wires, and means for inserting said second coil in the space between said walls, the diameter of said second coil being such that the coil frictiona-lly engages said first coil.

11. The machine according to claim 7, wherein said insulated sealing means comprises a cap, the shape of said cap being similar to the configuration of the space between the double walls, and including slots for the lead wires, said sealing applying means inserting said cap into said space and within said double walls, the lead wires extending through said slots and means for deforming the end of the inner wall over said cap, thereby securing said cap in place.

12. The machine according to claim 7, wherein the inner wall constitutes a coil form, said coil having an inside diameter slightly less than the diameter of said coil form, and said mounting means being capable of forcing said coil over said coil form.

13. The machine according to claim 12, and comprising further means for forming a second coil having lead wires extending in the same direction and parallel to the axis of the coil, the inside diameter of the second coil being slightly less than the outside diameter of said first coil, and means for forcing said second coil over said first coil, thereby forming a transformer.

14. A multi-station automatic machine for making an encapsulated inductor, the capsule being initially an open ended, double walled insulated cylinder, the inner wall constituting a coil form and the space within the inner wall defining an axial bore, the machine comprising a rotatable circular table, a plurality of workholders mounted on said table about the perimeter thereof, each of said workholders comprising a C-shaped bracket, the base of the C being afiixed to said table with the opposite end of the C forming an overhanging arm, a mandrel extending freely through aligned holes in the table, bracket base and over-hanging arm of the C, a block rigidly attached to the upper end of the mandrel, a spring mounted around said mandrel and attached to said block and said overhanging arm respectively, the spring urging said mandrel upwardly and in a counterclockwise direction, a stop attached to the back of said C shaped bracket, a stud attached to said block and extending perpendicular to said mandrel in a direction to contact said stop in one extreme angular position of said mandrel, a second stop rigidly attached to said mandrel and located between the base and overhanging arm, for limiting the vertical movement of said mandrel, a roller rotatably attached to said second stop for communicating a vertical force to said mandrel, the lower part of said mandrel, extending below said table, having a diameter slightly larger than the diameter of the cylinder bore; a first station comprising a vertically disposed capsule feed tube, the capsules being oriented in said tube with the open end facing down, a pivotally mounted capsule transport arm including a slot conforming in shape to the open end of said capsule, the slot being located to underlie said feed tube when the transport arm is in a first position for receiving a capsule, means for pivoting said arm to a second position where the capsule coaxially underlies said mandrel, means for applying a vertical downward force on said roller thereby causing said mandrel to move downwardly into said cylinder bore, and upon said downward force being released the mandrel being under spring tension returning to its original position carrying a cylinder with the open end facing down; a second station comprising a supply of wire, a vertically movable threading block, wire driving means for paying out wire from said supply to said threading block, a coil former comprising a rotatable spindle, an axially movable sleeve mounted on said spindle, the sleeve being segmented by a pair of slots aligned with said wire as it leaves said threading block, a lug on said spindle and an oppositely disposed offset pin on said sleeve, the wire being threaded between said lug and said pin, the offset therebetween being such that when said sleeve is moved down relative to said spindle the pin bends the wire against said lug, the wire bent by the movement of said sleeve constituting a first lead wire, means for rotating said spindle causing said wire to wind therearound while moving said threading block vertically upwardly to control the pitch of the wire turns, a second lead former, comprising a block having a curved portion adapted to bear against the body of the developed coil and a shoulder portion overlying the last turn of the coil, a lug adapted to be positioned under the wire extending from the last turn and at a given distance from the periphery of the coil, a vertically movable lead former arm spring urged in an upper position, a pin attached to said arm and adapted to be positioned above the extending wire, a wire cutter and arm actuator member mounted on said threading block, the wire cutter portion comprising a blade for severing the wire at the wire emerging end of said threading block, said arm actuating portion extending from said wire cutter a given dis tance above said blade and in a direction to bear on said lead former arm, means for depressing said wire cutter and arm actuator member, for severing the wire and causing said former arm to bend the extending wire against said lug, means for rotating said table, indexing means for controlling the rotation of said table so that as a coil is formed a cylinder is positioned directly above said spindle, means under control of said indexing means for raising said sleeve when the cylinder is positioned above said spindle, the sleeve comprising .a neck portion for forcing said coil off said spindle and around the cylinder coil form, the lead wires extending through the open end of said cylinder; said indexing means being adapted to operate said table rotating means upon said coil being inserted in said cylinder so that the coil loaded cylinder is carried to a third station, the third station comprising means for closing the space between the walls at the open end, thereby encapsulating the inductor, and said indexing means again operating said table rotating means so that the encapsulated inductor is carried to a final station, which comprises means for disengaging the cylinder from said mandrel.

15. The machine according to claim 14, and further comprising means at said coil forming station for axially rotating the mandrel prior -to the insertion of said coil in said cylinder, so that the lead wires extend from predetermined locations at the open end of the cylinder, said third station comprising an elevator for elevating an insulated cap into said open end, within and between the walls of said cylinder, the shape of the cap conforming to the open end of said cylinder and including locating slots for said lead wires, and means for forming the edge of the inner wall over said cap, thereby securing the cap in place.

16. The machine according to claim 15, wherein said means for axially rotating said mandrel comprises a rack and pinion arrangement mounted above said mandrel block, a boss extending from said block perpendicular to said mandrel, the boss and stud forming a T with said mandrel, a finger adapted to engage said boss connected to said pinion over an L-shaped connecting rod arrangement, said pinion being connected to the leg of the L, and said finger being connected to the base of the L at an end opposite from said leg, whereby rotation of said pinion is communicated to said finger which bears against said boss, thus angularly rotating said mandrel, the rotation being clockwise, moving said stud away from said stop.

17. The machine according to claim 14, wherein the open end of said cylinder is closed by a preformed insulated cap, the shape of the cap conforming to the open end of said cylinder and including notches for said lead wires, first second and third plate members, each having a. centrally located hole, the holes in said second and third plates being slightly larger than the diameter of said cylinder, and the hole in said first plate being slightly smaller than the width of said cap, the second and third plate members being contiguous and the first plate member being separated from said second plate member by approximately the thickness of a cap, a gravity operated tube, a pivotal cap transport arm having a recess conforming to a portion of the peripheral contour of said cap, the recess underlying said feed tube when the arm is in a first position, means under control of said indexing means for pivoting said arm when a cap is positioned in the recess, the arm being adapted to carry said cap to the center of said first plate over said centrally located hole, a vertically extending pin on said arm extending through slots in said second and third plate members, the slot in said second plate being shaped to permit the pin to ride idly therein, the slot in said third plate being shaped so that movement of the pin with said arm causes rotation of this plate, two pairs of oppositely disposed straightening bars slidably located in grooves in the surface of said second plate, the bars being radially disposed along quadrant lines of the plate, the ends of the bars movable into the hole having chamfered corners, each of said bars carrying pins mounted on the surface thereof and extending into respective slots in said third plate member, the slots being shaped so that rotation of said third plate member by movement of the arm carrying a cap to the center of said first plate causes inward radial movement of said straightening bars, means under control of said indexing means for lowering a mandrel so that the lead wires extend into the hole in said second plate between adjacent chamfered edges prior to the movement of said cap transport a-rm, whereby movement of said cap transport arm causes said bars to straighten and locate the lead wires while carrying a cap to the center of the first plate, the return of said arm to the first position causing a counter-rotation of said third plate and a retraction of said straightening bars from the hole in said second plate, an elevator underlying said cap adapted to pass through the hole in said first plate, means under control of said indexing means for raising said elevator to carry said cap into the space between and within said walls, thereby enclosing said coil, the lead wires extending through the notches in said cap,

said mandrel being raised and said table being rotated to a fourth station, a rotatable swaging tool at said fourth station, said mandrel adapted to be lowered at said fourth station so that the swaging tool contacts the end of the inner Wall, the frictional heat produced by the rotating swaging tool on the end of said Wall causing the end to become plastic, the swaging tool being shaped to rol-lsaid end over said cap thereby securing the cap in place.

18. The machine according to claim 14, and further comprising a second coil forming station located adjacent said first coil forming station, both said coil forming stations being substantially the same, the diameter of the second coil however, 'being such as to fit with frictional 2,334,880 11/1954 Marlow 29-3351 3,064,333 11/1962 Kristiansen et a1. 29155.56

RICHARD H. EANES, JR., Primary Examiner.

WHITMORE A. WILTZ, Examiner.

Claims

1. AN AUTOMATIC MACHINE FOR MAKING AN ENCAPSULATED INDUCTOR, THE CAPSULE INITIALLY AN OPEN ENDED, DOUBLE WALLED INSULATED CYLINDER, THE MACHINE COMPRISING MEANS FOR FORMING A CYLINDRICAL COIL HAVING LEAD WIRES, THE LEAD WIRES EXTENDING IN THE SAME DIRECTION AND PARALLEL TO THE AXIS OF THE COIL, MEANS FOR MOUNTING THE COIL IN THE SPACE BETWEEN SAID WALLS WITH THE LEAD WIRES EXTENDING THROUGH THE OPEN END OF THE CYLINDER, AND MEANS FOR APPLYING INSULATED SEALING MEANS TO THE OPEN END OF THE CYLINDER WITH THE LEAD WIRES EXTENDING THERETHROUGH, THEREBY COMPLETELY ENCLOSING SAID COIL BETWEEN THE DOUBLE WALLS.