US3618868A

US3618868A - Indexing core holder for a toroidal winding machine

Info

Publication number: US3618868A
Application number: US23409A
Authority: US
Inventors: Bohuslav Vavrinec
Original assignee: Tesla AS
Current assignee: Tesla AS
Priority date: 1970-03-27
Filing date: 1970-03-27
Publication date: 1971-11-09
Anticipated expiration: 1988-11-09

Abstract

Small rectangular toroidal cores are held for winding by a pair of clamping jaws mounted on a slide to be indexed for precise placement of the winding by a reversible, step-by-step transmission. The transmission includes a driven cam acting through a stepping pawl and ratchet means to drive associated gearing terminating in a rack carried by the slide. The direction of indexing is reversed by a shiftable, two-way bevel clutch in said gearing. The clutch is controlled by adjustable switchactuating means carried by the slide and operably connected to clutch-operating means.

Description

O United States Patent 11113,618,868

[72] Inventor Bohuslav Vavrlnec [56] Relerences Cited Prague, Czechoslovakia UNITED STATES PATENTS [21] f g' 1970 2,656,124 10/1953 Stevens 242/4 [22] e 2,657,865 11/1953 Bennert et al. H 242/4 [45] Patented Nov. 9, 1971 [73] Assignee Tesla, narodnl podnlk FOREIGN PATENTS p Czechoslovakia l,144,8l6 3/1969 Great Britain 242/4 Primary Examiner-Billy S. Taylor Allorneys- Richard Low and Murray Schaffer [54] INDEXING CORE HOLDER FORATOROIDAL ABSTRACT: Small rectangular toroidal cores are held for WINDING MACHINE winding by a pair of clamping jaws mounted on a slide to be in- 5 Claims6 Drawing Figs dexed for precise placement of the winding by a reversible, step-by-step transmission. The transmlssron includes a driven cam acting through a stepping pawl and ratchet means to drive [52] U.S.Cl 242/4, associated gearing terminating in a rack carried by the slide. 74/142 The direction of indexing is reversed by a shiftable, two-way [Sl] Int. Cl H0lf4l/08 bevel clutch in said gearing. The clutchis controlled by ad- [50] Field of Search 242/4, justable switch-actuating means carried by the slide and operably connected to clutch-operating means.

l c j 1.24

FATENTEDNDV SHEET 4 OF 6 INVEN'IOR. 'BoHuSL nv VHvmA/ac Y PATENTEUuuv 9 Ian SHEET 8 BF 6 INDEXING CORE HOLDER FOR A TOROIDAL WINDING MACHINE BACKGROUND OF THE INVENTION This invention relates to a clamping head adapted to perform a straight-line, step-by-step movement with the possibility to reverse this movement, which clamping head can be used particularly for winding of calls on closed rectangular cores.

Coils of miniature closed two-column ferrite transformer cores of rectangular shape have been wound manually. Actual microtoroid coil winding machine enable an automatic winding of miniature closed cores of annular shape only, whereby the feed of the core is unidirectional and rotational. Similar coil-winding machines are for instance described in U.S. Pat. No. 2,978,193 and in the British Pat. No. 911,622. It is however impossible to wind on similar machines coils of miniature two-column ferrite transformer cores of closed rectangular shape.

SUMMARY OF THE INVENTION It is an object of this invention to provide a clamping head, which would enable to wind coils on miniature closed cores of rectangular shape automatically on existing shuttleless coilwinding machines.

It is another object of this invention to provide a compact unit, which could be mounted on existing shuttleless coilwinding machines to replace clamping heads for winding of coils on toroidal cores.

Bearing these and other objects in mind we provide a clamping head having a sliding board with adjustable clamping jaws for the core, which sliding board receives a'step-by-step movement from a ratchet wheel to which an intermittent rotary movement is transmitted after one finished turn of the coil, with limit switches actuating means for changing the direction of the step-by-step movement transmitted by the ratchet wheel to the sliding board after one layer of turns of the coil has been finished.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view with parts of the clamping head in section along the line 1-1 in FIG. 2a.

DESCRIPTION OF PREFERRED EMBODIMENT With reference to FIG. I there is the left front part 1.1 and the right front part 1.2 of the frame of the clamping head with a vertical sliding board 1.3 with straight-line, three-point ball guidings between both front parts 1.1 and 1.2, whereby two balls 1.4 are provided in a guiding groove in the left front part 1.1 whereas a short guide piece 1.31 provided with a guiding groove and with a single ball 1.30 connected with the right front part 1.2 by a flat spring 1.32 eliminates any clearance of the guiding. The sliding board 1.3 supports a stable jaw 1.23 and in addition a jaw 2.14 (see FIG. 2a) resiliently pressed against the clamped core 1.24 by fiat springs 2.17, fixed on the sliding board by means of a bracket 5.1 (see FIG. 5 The sliding board 1.3 supports in addition on its rear side a rack 1.5 meshing with a pinion 1.6 (see FIG. 1 and 2a) the direction of rotation of which is determined by the position of a bevel clutch 1.13 by means of friction disks 1.11 and 1.12 and by means of bevel gears 1.9 and 1.10 fixed to said friction discs 1.11 and 1.12 respectively, engaging with a bevel gear 1.8 fixed on the shaft of the pinion 1.6. A bracket 1.7 for a rotatable mounting of the pinion is fixed on the front part 1.1 of the clamping head. The body 1.13 of a both-way bevel clutch forms a unit with the shaft 1.14, this shaft being mounted easily slidably in sleeves 1.15 and 1.16 passing through the front parts 1.1 and 1.2 respectively. The sleeves 1.15 and 1.16 are in both front parts 1.1 and 1.12 axially adjustable by means of threads and their extremities facing the clutch body are taking over the axial forces of the clutch, fonning races for balls of thrust bearings of the friction disks 1.11 and 1.12 and of the bevel gears 1.9 and 1.10 which are a unit with the friction disks 1.11 and 1.12. The friction disk, which is just out of engagement with the clutch body 1.13 is freely turning on the shaft 1.14. The shaft 1.14 extends on both ends beyond the front parts 1.1 and 1.2 whereby a ratchet wheel 1.17 for a step-by-step motion of the clutch body 1.13 is fixed on the shaft and extending beyond the front part 1.2. A two-arm lever 1.18 is freely rotatably mounted on the hub of the ratchet wheel 1.17, which lever 1.18 actuates by its oscillating movement the ratchet wheel in one direction by means of the pawl 4.3 (see FIG. 4) mounted on the lever, whereas a stop pawl 4.4 securing the ratchet wheel against rear movement is mounted on the front part 1.2. The oscillating movement is transmitted to the lever 1.18 by a lifter 1.20 (see FIG. 1) actuated by the coil-winding machine having a constant stroke, whereas the stroke of the lever 1.118 is adjustable by a stop screw 4.1 limiting the rest position of the lever into which the lever is returned by the pull spring 4.2. The shaft 1.14 with the clutchbody 1.13 is shifted into the position indicated in FIG. 1 by the pressure of a flat spring 1.19 fixed by means of two brackets 1.28 on the front part 1.2, whereby the spring force can be adjusted by prestressing by means of two screws 1.29 (FIG. 1). The shaft 1.14 with the clutch body 1.13 can be pressed against the force of the spring 1.19 by means of an electromagnet 1.21 fixed on the external side of the front part 1.1 the pressure being transmitted by way of an axial guiding bolt 1.22 of the core of the electromagnet against the face of the shaft 1.14, extending beyond the guiding sleeve 1.15. The automatic changeover switching of the electromagnet for changing the direction of feeding of the core 1.24 is accomplished by limit switches mounted on the front part of the clamping head and by adjustable stops on the sliding board 1.3. The arrangement of these limit switches and stops is indicated in FIG. 2a and 2b, whereby FIG. 2a is a side view in partly section on the limit switch and on the stop causing a changeover in the upper extreme position of the sliding board, whereas FIG. 2b is a detailed side view of a part of the limit switch and stop in partly section causing the changeover in the lower extreme position of the sliding board. The arrangement of both limit switches is similar. The limit switch for the upper extreme position shown in FIG. 2a is a miniature single-pole pushbutton changeover switch 2.2 and a two-arm lever 2.3 mounted on a mounting board 2.1 within a cover 1.35 with a spring 2.5 pressing in the rest position on the push button of the changeover switch 2.2, maintaining it in the depressed position. The board 2.1 is fixed on the front part 1.2 and the adjustable stop for this limit switch is represented by a screw 2.6 passing through an extension 2.8 on the upper part of the sliding board 1.2, provided on the lower part with a head striking in the upper extreme position from the bottom against the shorter arm of the lever 2.3, releasing thus for a short time the pushbutton of the change over switch 2.2. The limit switch for the lower extreme position according to FIG. 2b is similarly represented by a miniature single-pole pushbutton changeover switch 2.11 and a two-arm lever 2.12 mounted both on a mounting board 2.10, whereby the longer arm of the lever 2.12 does not act upon the pushbutton of its changeover switch in the rest position, as the pushbutton is pressed upwards by a screw 2.7 passing through the extension 2.9 on the upper part of the sliding board 1.3. Due to the action of this screw the pushbutton of the changeover switch is pressed for a short time in the lower extreme position of the screw 2.7, that is when the sliding board 1.2 is in its lower extreme position. In the position of the bevel clutch as indicated in FIG. 1, that is when the electromagnet is deenergized, the sliding board 1.2 is moving upwards. The mounting board 2.10 is fixed on the front part 1.1.

Both front parts 1.1 and 1.2 of the clamping head are held together by distance rods 5.2, 5.3 and 5.3 and 5.4 (see FIG. and by a distance prism 1.25, which can serve as a clamping bracket.

In operation the core 1.24 of rectangular shape is clamped between the lower jaw 1.23 and the upper jaw 2.14 and one side of a skein of a conductor, which has to be wound on the core 1.24 is guided through the opening of the core. After each turn wound on the core 1.24, the lifter 1.20 actuated by the movement of the coil-winding machine strikes the twoann lever 1.18 turning it against the force of the spring 4.2 (see FIG. 4), the pawl 4.3 engaging into the teeth of the ratchet wheel 1.17 takes along the ratchet wheel, 1.17 whereby the stop pawl 4.4 slides along the teeth of the ratchet wheel 1.17. When the lifter 1.20 returns into its rest position, the spring 4.2 forces the two-arm lever 1.18 back until it strikes the adjustable stop screw 4.1 whereby the pawl 4.3 slides along the teeth of the ratchet wheel 1.17 which is prevented from turning by the stop pawl 4.4. The stroke of the two-arm lever 1.18 and thus also the advance of the ratchet wheel 1.17 can be adjusted by the stop screw 4.1.

The movement of the ratchet wheel 1.17 is transmitted to the shaft 1.14 (see FIG. 1) and to the body 1.13 of the bevel clutch which transfers this movement in the position indicated in FIG. 1 to the left friction disk 1.11 and via the left bevel gear 1.9 to the bevel gear 1.8 actuating the pinion 1.6, which meshes with the rack 1.5 fixed to the sliding board 1.3 which thus moves step-by-step either upwards or downwards. When the prior-adjusted extreme position of the sliding board 1.3 is reached, one of the limit switches is actuated, for instance the adjustable screw 2.6 (see FIG. 2a), taken along by the sliding board 1.3 which by way of the two-arm lever 2.3 causes a change of the changeover switch 2.2, energizing the electromagnet 1.21 (see FIG. 1), which shifts the shaft 1.14 against the force of the flat spring 1.19 to the right, whereby the other part of the bevel clutch for the movement in the opposite direction comes to action and the whole operation is repeated. The sliding board performs a step-by-step movement in the opposite direction until the stop screw 2.7 strikes the two-arm lever 2.12 and causes actuation of the other change over switch 2.10 which again deenergizcs the electromagnet 1.21, whereby the flat spring 1.19 forces the shaft 1.14 into the position indicated in FIG. 1.

This clamping head enables thus an automatic feeding of closed cores of rectangular shape when winding coils on said cores on shuttleless core-winding machines. This clamping head can be advantageously designed as a removable unit replacing an existing feeding device of toroidal cores on said coil-winding machines.

I claim:

1. A clamping head adapted to perform a straight-line, stepby-step movement with the possibility to reverse this movement, particularly for clamping of cores on coil-winding machines comprising in combination:

a frame,

a sliding board mounted in sliding fashion on this frame,

a couple of adjustable clamping jaws arranged on said sliding board,

a rack fixed to said sliding board,

a shaft, supported rotatably and axially shiftably by said frame,

a first part of a two-way bevel clutch fixed to said shaft, two second parts of the bevel clutch mounted freely rotatably on said shaft, adapted to engage alternately with side first part,

a bevel gear with a pinion supported by said frame,

said bevel gear meshing with both second parts of the bevel clutch,

said pinion meshing with said rack fixed to the sliding board,

a ratchet wheel with pawls for one-direction, step-by-step movement fixed on said shaft,

means for transmitting to said ratchet wheel an intermittent rotary movement after finishing one turn of the coil,

limit switches actuating means for changing the position of the two-way bevel clutch. t 2. A clamping head as claimed in claim 1 said means for changing the position of the two-way bevel clutch comprising an electromagnet energized in the course of feeding of the sliding board in one direction and acting on the shaft of the bevel clutch, with a spring force returning the shaft of the bevel clutch into the opposite position for feeding the sliding board in the opposite direction.

3. A clamping head as claimed in claim 1 the shaft supported rotatably and axially shiftably in adjustable sleeves, the extremities of said sleeves facing the first part of the bevel clutch forming races for antifriction thrust bearings of both second parts of the two-way bevel clutch.

4. A clamping head as claimed in claim 1 said sliding board guided by three-point ball guidings with two balls guided in a groove of a frame part on one side and a third ball guided in a groove of a second frame part on the other side, one of said frame parts spring loaded to eliminate any clearances.

5. A clamping head as claimed in claim 2 comprising limit change over switches for energizing and deenergizing the electromagnet changing the feeding direction of the sliding board after it has reached its extreme positions.

Claims

1. A clamping head adapted to perform a straight-line, step-bystep movement with the possibility to reverse this movement, particularly for clamping of cores on coil-winding machines comprising in combination: a frame, a sliding board mounted in sliding fashion on this frame, a couple of adjustable clamping jaws arranged on said sliding board, a rack fixed to said sliding board, a shaft, supported rotatably and axially shiftably by said frame, a first part of a two-way bevel clutch fixed to said shaft, two second parts of the bevel clutch mounted freely rotatably on said shaft, adapted to engage alternately with side first part, a bevel gear with a pinion supported by said frame, said bevel gear meshing with both second parts of the bevel clutch, said pinion meshing with said rack fixed to the sliding board, a ratchet wheel with pawls for one-direction, step-by-step movement fixed on said shaft, means for transmitting to said ratchet wheel an intermittent rotary movement after finishing one turn of the coil, limit switches actuating means for changing the position of the two-way bevel clutch.

2. A clamping head as claimed in claim 1 said means for changing the position of the two-way bevel clutch comprising an electromagnet energized in the course of feeding of the sliding board in one direction and acting on the shaft of the bevel clutch, with a spring force returning the shaft of the bevel clutch into the opposite position for feeding the sliding board in the opposite direction.

5. A clamping head as claimed in claim 2 comprising limit changeover switches for energizing and deenergizing the electromagnet changing the feeding direction of the sliding board after it has reached its extreme positions.