US3106944A - Wire winding machines - Google Patents

Description

Oct. 15, 1963 ),COLQUHOUN y '3,106,944

WIRE WINDING MACHINES 2 Sheets-Sheet 1 Filed June 1, 1961 INI/En/Tek .mm coLQuHou/v Oct. 15, 1963 J. coLQUHoUN 3,106,944

WIRE WINDING MACHINES Filed June l, 1961 2 Sheets-Sheet 2 muv cobu HouN ES 6mm/a+ @56E/m www United States Patent 3,106,944 WIRE ING MACHlNES John Colquhonn, Castletown, Sunderland, England, as-

signor to Associated Electrical Industries Limited, London, England, a British cnmpany Filed Enne i, 1961, Ser. No. lll-1,226 Claims priority, appiication Great Britain duly 2S, 196i? 8 Claims. (Cl. 34e-71.5)

The invention relates to wire winding machines and especially to such machines for winding turns of comparatively thin wire in helical fashion around straight lengths of comparatively thick and rigid support wire. Such machines are used, for example, `for the production of the grids of thermionic valves.

Known machines of this kind may comprise a fixed bed and a headstock including a gearing housing, which encloses gearing for rotating a yoke carrying spools of support wire which are fed through the headstock and a rotating Winding head and along guide channels in a nose piece, commonly known as a grid nose, secured to and projecting from the winding head. The emerging ends of the support wires are gripped in a spring-loaded chuck carried at the end of a coaxial draw bar, which is rotated in known manner at the same speed as the yoke `and the winding head by another set of gears, the draw bar being advanced at the same time by a lead screw at a known rate according to the pitch of the helical turns required in the finished grids. At the same time the grid helical turns are wound round the support wires as they pass over the tip of the grid nose, the grid wire being taken oli in known manner from a spool. lt is the practice to wind the grids yby what is known as the break and re-feed technique, and to nick and swage the helix turns to the support wires.

Such machines Iare designed to produce a stick of grids for example, 11"-12 lengths of support wires with grids Wound at intervals along them.

Assuming that the feed of the helix wire to the break and re-feed mechanism and the setting of the nick and swage cutters and rollers has been attended to, once the drive has been engaged the machine proceeds to wind `grids at pre-set intervals along the support wires until the draw bar is at the limit of its travel to the right. The

machine is ystopped atthis point by the operation of a micro-switch or some similar means.

At the end of the run the stick'is cut near theV grid nose tip by foot operated cutters.

Whilst the next stick of grids is being wound the operator stretches the iirst stick longitudinally and then cuts the stick up into separate grids using a hand and foot operated machine, located on the bench in front of the winding machine. It is necessary lirst to stretch the grids longitudinally because when the stick is removed from the machine it is rarely straight, but almost'invariably has a set in one direction.

The rate of production of grids is governed mainly by the speed of translation of the draw bar which is' moved by the lead screw at constant speed during the grid winding periods and during the intervening blank periods representing the spacing between individual grids in a stick.

An object of the invention is to provide an improved automatic grid Winder capable of a higherspeed of production and of producing separate grids rather than a stick of grids as does the known machine.

According to the invention a wire winding machine having a rotating winding head includes means for repeatedly performing a cycle of operations, including gripi ping and drawing support material through the winding head and cutting it into lengths after being wound, the said means comprising jaws movably mounted in a carriage slidable axially with respect to the winding head and control means dependent on the position of the carriage for operating the jaws.

More particularly the invention comprises a wire winding machine of the kind for winding wire in helical fashion upon rotating support material comprising a headstock provided with rotatable means for guiding a supply of support material centrally therethrough, and a winding head for supplying the wire to be wound in helical form around the support material, means for gripping and drawing the support material through the headstock whilst being wound and for cutting it into lengths after winding, said drawing and cutting means comprising la carriage adapted to support cutting jaws positioned around the support material, means for reciprocating the said carriage together with the jaws coaxially of the headstock and means co-operating with the said jaws during the travel of the carriage to cause said jaws to close upon and to grip the support material whilst the latter is being wound and by increasing pressure of said jaws to cut the said support material after a predetermined length thereof has been wound with the wire.

in order to reduce the operating time to the minimum the means for reciprocating the carriage comprises a cam driven in timed relationship with the winding head by means of gearing, the said cam and its follower being adapted to eifeot a rapid return of the carriage to the starting point for gripping a fresh length of support wire after a previously wound length has beencut.

An example of a wire winding machine according to the invention will now be described with reference tothe accompanying diagrammatic drawings, in which:

FIG. l is an elevation showing the main components of the machine;

FlG. 2 is a cross-section on a larger scale in aplane containing the main axis of the machine and showing some details of the sliding carriage used in FIG. l;

FIG. 3 is a perspective view of a still larger scale of the delivery end of the winding head;

FG. 4 is an end View partly in section and substantially along line lV-lV in FGURE l to show part of the 'arrangement shown in FIG. 2;

FiG. 5 is a plan view of two support wires emerging from Ithe winding head and illustrating the sequence of operations in for-ming and cutting separate grids;

FIG. 6 is a similar view to FIG. 5 shown in elevation, and

FlG. 7 is a perspective View of one example of means :for preventing retraction of the support wires after a wound grid section has been cut.'

Referring now to the drawings and particularly to FIG.

1 the machine comprise-sa bed plate 1 upon which is mounted a fixed headstock 2 enclosing gearing for rotating a yoke 3 carrying spools' 4 and v5 of support wire, such support Wire passing through the headstock and through a winding head 6 also rotated by the said gearing at the same speed as the yoke 3, the support Wires 7 and 3 being retained in parallel relationship by wire guiding means when issuing from the winding head. The elements above referred to may be of known construction and will not be referred to in more detail. Y

Also ymounted upon the bed plate i are a further fixed 'gearing housing 9 and a tail stock 10, which may also include gearing, the purpose of these components being to support and to drive a draw tu-be 51S mounted inside the tube il coaxially o-f and -at the same speed las the winding head 6, one Vor more lay shafts (not shown) being provided between the various gear housings.

Slida-bly mounted upon the bed plate 1 is a carriage i?, the detail of which is seen more clearly in FIG. 2,

which carriage is reciprocated axially by means of a` cam i3 driven from suitable gearing in the housing 9 and operating through a parallel link follower mechanism 14.

An extension of the draw tube 15 extends freely through a support cone 16 and yand integral ange '17. Internally'of the carriage 12 a split tube 13 is keyed or otherwise secured to the extension `and carries a pair of transverse bearing pins 19* for lever arms 2li carrying gripping and cutting jaws 21 with tungsten carbide tips adapted to close onto the support wires 7 and 8 and to draw said wires from the winding head and afterwards to sever the said wires, these operations being performed at the `appropriate times in the working cycle in a manner to be further described.

The assembly of tubes 15 `and 13 and Icutters 21 is movable -aXially by the carriage *12 -and is rotatable inside the carriage at the `same speed as the winding head and is mounted on ball bear-ings such as 22 and 22a.

The cone Iand flange have a thrust-bush 29 bearing 'against a spring r23, and the chamfered ends of the cutter @arms 20 bear against the cone surface 116 so -that when the 'carriage is moved to the right closing land gripping pressure is applied to the jaws due to the resistance of the spring 23.

Also driven by suitable gearing contained within the gear housing 9 are means for controlling the relative axial movements of the cone and flange w-ith respect to the carriage 12 to achieve the gripping and drawing of the support wires 7 and 8 and the subsequent cutting thereof by the jaws 21.

Such control means comprises a rigid stop 24 pivoted to move in a plane normal to the `axis of the draw tube 15 into and out of the path of the flange, such movements being effected by suitable gearing 30 at the appropriate times.

Rotatable about a xed horizonal axis is a timing cam 25, the purpose of which is to control the movements of the cone and liange, rand hence of the cutters, after the support wires have been cut. The said timing cam 25 is adapted to co-operate with the upper end of a lever .26 the lower end of which is controlled by an arm 27 fixed upon the carriage 12.

The grid wire 28 to be wound round the pair of supports 7 and S is supplied -to the winding head 6 in known mannerV and the means for feeding the said wire, swaging it to the support wires and cutting it `after a grid has been wound, lform no part of the present invention and are therefore not described herein.

The sequence of movements of the parts of the machine during a working cycle kare indicated diagrammatically in FIGS. and 6, in which, for convenience of description, it will be assumed that only grids Q1 and Q2 have been wound and that 'grid Q3 is about to be wound so that the working cycle begins with grid Q2 in the position of Q3 and `grid, Q1 in the position of grid Q2.

'I'he jaws 21 now ygrip the wires 7 and `S at position I Iand draw them from the grid nose 31 of the winding head to position IV, the :grid Q3 being wound in the meantime. At position IV the jaws vclose and sever the wires and the grid Q1 is delivered to a receptacle. Immediately after this the jaws open, move a short distance to the right lto position IVa and then return to position I Where they close on to the wires once more and the cycleis repeated. There is a short dwell time at position I, and the reason for this and for the small movement to the right beyond position IV will appear later.

It will be evident from Vthe diagram that the travel D of the carriage is equal to slightly more than the length of a complete grid, i.e. from the mid-point of the space V'between one pair of grids to just beyond the mid-point of the next space. =It is arranged by design of the cam 13 that ther-carriage shail travel relatively quickly when the helix turns are not actually being wound on the wires V7 and 8 in order that the output of the machine shall be as high `as possible. Hence the return movement of the jaws from position lVa to position I is quick and the iilrst part i of` their lforward movement, i.e. from I Vto II is also relatively quick. Thereafter the speed of the jaws to position III is governed by the pitch of the helix turns and is uniform if `a uniformly wound grid is to be produced and is varied appropriately if a variable pitch grid is required.

The arrangement shown is one of the 'two which are the most economical in terms of the acceleration of the carriage carrying the jaws and hence in ter-ms of wear in the machine. The other is that in which the winding of the grid Q3 is about to start when the jaws are at position IV. Any other -arrangement involves two speed changes instead of one as the carriage moves from I to IV.

Considering now the sequence of movements from position fl with the jaws gripping the support wires as shown. As the carriage 12 moves to the right it pushes with it the flanged cone member 16 against the compression spring 23. The spring 23 is so designed that whilst the grid is being wound the pressure of the cone `16 against the bevelled ends of the arms 20, which are pivoted at '19, will cause `the jaws to grip the support wires 7 and 8 firmly but without severing them. Near the end of the travel of the carriage 12 to the right (i.e. at point IV in FIGS. 5 and 6) the flange :17 of the `cone 16 strikes the stop 24 and the movement of the cone =to the right is momentarily arrested. The carriage 12 continues to move, however, relative to the cone 16 and the ends o-f the arms 20 are pulled suiciently hard against the cone for the jaws 21 to sever the support wires. An air blast from a ilexible tube 32, attached to carriage `12, then blows the finished grid down tube 11 whence it `falls into the tray 33. Y

As soon las the wires are severed, a cam or other suitable mechanism (not shown) comprised in the gearing 30 moves the stop 24 `away from the flange 17 of the cone 16; rat the same time the arm 27 Iattached to the carriage bears upon the lower end of the movement amplifying lever 26, `and the small further movement of the carriage (from IV to IVa, FIGS. 5 and 6) imparted by cam 13 causes the Icone 16 and flange 17 to move rapidly to the right. The jaws 21 (which are spring-urged into the open position) then open and the carriage is returned rapidly to the position I in IFIGS. 5 and 6, the open jaws passing over the wound lgrid Q2 and coming to rest yabove the mid-point of the'space between Q2 and grid Q3.

In the meantime the travel to the right of the cone and flange will have been stopped by the spring 23 and they will be returning to the left under the influence of this spring. If the ange 17 were allowed to travel until stopped by the arms 20, the force of the impact would cause the jaws 21 to sever the support wires. Accordingly, it is arranged that as soon as the flange 17 has moved to the right of the stop 24, the latter is returned by cam action to its original position and so takes the full force of the impact of the cone and flange on their return. In the meantime the cam 25 has rotated and moved the lower end of lever 26 until it is just touching the flange 17. At this point the stop 24 is again moved away from the ange 17 and further rotation of cam 25 permits the lever 26 gently to return the cone to the arms 20. The support wires are thus gripped again, the carriage 12 proceeds to move to the right and the above de- Y of the pivoted stop 24 shown in FIG. l, if, for example f because of the width of the ange 17 and the geometry of the machine it is not possible to cause bush 29 to travel sufficiently far to the right for the left-hand edge of iange 17 to clear the right hand edge of stop 24. VIn

such case the additional stop located to the left of stop 24 Y could be used to arrest the leftward movement of the ilange before passing over the control to the cam 25 and lever 26.

Some means is required to-prevent the grid support Ywires running back through the winding head 6 when the Wires are severed at point lV (FIGS. 5 and 6). This is conveniently done by providing two spring loaded iingers (not shown) which pass radially into the winding head and press onto the wires as they pass through the holes in the winding head.

An alternative arrangement for anchoring the support wires is shown in FIG. 7. Part of the channelled cylindrical section of a grid nose 35 is removed to form the at bed 36 over which the support wires 7 and 8 pass. Two channel-section holding blocks 37 t over the bed 36 to engage the support wires. At least one block is spring loaded, for example, one block may be secured to the bed and the other spring loaded so that the wire is held against the fixed block. An advantage of this device is that it may serve as a straightening die, because it is very important to ensure that the support wires 7 and 8 upon which the helices are wound are straight. For example, if the support wires after the grids are wound are found to be curved owing to a set on the wire, i.e. if the grids are not plane, this can often be counteracted by so positioning the fixed one of the blocks 37 that when the support wires pass through there is a tendency to bend the wires in the opposite sense. The pressure exerted on the wire by the members 37 also iniiuences the degree of straightening achieved since the higher the pressure the greater the tension in the wires 7 as they are pulled along the grid nose. There is a limit to this of course since the tension must not be so great that the jaws 2i (FIG. 2) will slip instead of gripping the wires.

Known devices for winding the grid wire 28 by the break and re-feed method and to nick and swage the wire to the support wires may be provided.

Notching punches may also be provided in the machine so that grids with ready notched supports may be produced.

What l claim is:

1. A wire winding machine of the kind adapted for the production of thermionic valve grids by winding comparatively thin wire around thicker support material fed through a winding head inthe axial direction of the winding operation and comprising a freely axially slidable carriage, coacting jaws positioned on opposite sides of the axis of feed of the winding head pivoted upon transverse axes on said carriage for operating upon the support material, means for reciprocating said carriage together with said jaws carried thereby parallel to said axis and causing periodic movements of said jaws transversely of the axis in timed relationship to the reciprocating movements of the carriage to repeatedly perform a cycle of operations consisting essentially in sliding said carriage axially towards the Winding head, causing the saidrjaws to grip the support material, reversing the carriage movement to draw the support material through the winding head while the wire is being wound and increasing the pressure of said jaws at the end of the reverse stroke of the carriage to cut oli the lengths of wound support material, each cutting operation at the end of a cycle being followed by the forward return of the carriage to bring the jaws into position for gripping the support material at the start of a new cycle, said means for reciprocating the carriage compising a cam and associated follower driven in timed relationship with the winding head, the said cam and its follower being adapted to elect a rapid return of the carriage to the starting point for gripping a fresh length of support wire after a previously wound length has been cut, a spring-supported abutment opposing the axial travel of the carriage during the winding of the support material with wire and operatively engaging said jaws for exerting a component of the spring reaction upon the jaws to grip the wire during that movement of the carriage, and a stop adapted to arrest the motion of the said spring supported abutment at a predetermined point in the travel of the carriage when the cutting of the support wire is to be effected.

2. A machine according to claim 1, wherein the gripping and cutting jaws are spring biased into the open position, and the said stop is movably mounted and comprising means for imparting rapid axial separation of the spring supported abutment and carriage after the cutting of the support wire, and means for removing the said stop from the path of the spring-supported abutment so as to relieve the pressure on the gripping and cutting jaws to allow the same to open before the carriage is returned to the starting point.

3. A machine according to claim 2, wherein the means for imparting rapid separational movement of the springsupported abutment and the carriage after the cutting of the support wire comprises a motion-amplifying linkage connected between the said carriage and the said springsupported abutment.

4, A machine according to claim 3, wherein said motion-amplifying linkage comprises a lever arm movable about a lixed pivot and adapted to operatively engage said abutment, the said arm lying in the path of a striker member carried by the carriage so that said striker swings the said lever arm about its pivot to move the springsupported abutment away from the carriage to allow the said jaws to be open.

5. A machine according to claim 2, including means for preventing a rapid return of abutment towards the carriage under the influence of the spring comprising means for replacing the said rigid stop in the path of abutment to arrest the same.

6. A machine according to claim 4, including means for ensuring gradual return of the said abutment towards the carriage after cutting of the wire comprising a cam adapted to control the said pivoted lever arm, the said cam being driven in timed relation with the winding head and with the carriage reciprocating cam.

7. A machine according to claim l, including means for preventing rapid return of the said spring-supported abutment towards the carriage comprising a second removable abutment and means for controlling the motion thereof to bring the same in the path of the springsupported abutment after the cutting of the wire.

8. A wire winding machine of the kind adapted for the production of thermionic valve grids by winding comparatively thin wire around thicker support material fed through a winding head in the axial direction of the winding operation and comprising an axially slidable carriage; drawing, gripping and cutting means comprising jaws pivoted upon transverse axes in the carriage for operating upon the support material, said jaws being spring biased into the open position, means for reciprocating said carriage together with the jaws carried therein, a spring-supported abutment opposing the axial travel of the carriage in one direction during the winding of the support material with wire and thereby exerting a component of spring reaction upon the jaws to grip the support material to draw the same from the winding head during the said travel of the carriage; and a stop adapted to arrest the motion of the said spring supported abutment and increase the jaw pressure at a predetermined point in the travel of the carriage thus effecting the cutting ofthe support wire at said point.

References Cited in the tile of this patent UNITED STATES PATENTS 1,970,599 Franke Aug. 21, 1934 2,181,288 Washburn Nov. 28, 1939 2,727,540 Marshall et al. Dec. 20, 1955 3,001,556 Bans et al Sept. 26, 1961

Claims (1)

1. 8. A WIRE WINDING MACHINE OF THE KIND ADAPTED FOR THE PRODUCTION OF THERMIONIC VALVE GRIDS BY WINDING COMPARATIVELY THIN WIRE AROUND THICKER SUPPORT MATERIAL FED THROUGH A WINDING HEAD IN THE AXIAL DIRECTION OF THE WINDING OPERATION AND COMPRISING AN AXIALLY SLIDABLE CARRIAGE; DRAWING, GRIPPING AND CUTTING MEANS COMPRISING JAWS PIVOTED UPON TRANSVERSE AXES IN THE CARRIAGE FOR OPERATING UPON THE SUPPORT MATERIAL, SAID JAWS BEING SPRING BIASED INTO THE OPEN POSITION, MEANS FOR RECIPROCATING SAID CARRIAGE TOGETHER WITH THE JAWS CARRIED THEREIN, A SPRING-SUPPORTED ABUTMENT OPPOSING THE AXIAL TRAVEL OF THE CARRIAGE IN ONE DIRECTION DURING THE WINDING OF THE SUPPORT MATERAIL WITH WIRE AND THEREBY EXERTING A COMPONENT OF SPRING REACTION UPON THE JAWS TO GRIP THE SUPPORT MATERIAL TO DRAW THE SAME FROM THE WINDING HEAD DURING THE SAID TRAVEL OF THE CARRIAGE; AND A STOP ADAPTED TO ARREST THE MOTION OF THE SAID SPRING SUPPORTED ABUTMENT AND INCREASE THE JAW PRESSURE AT A PREDETERMINED POINT IN THE TRAVEL OF THE CARRIAGE THUS EFFECTING THE CUTTING OF THE SUPPORT WIRE AT SAID POINT.

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