US3151437A - Method and apparatus for twisting wires - Google Patents

Description

Oct. 6, 1964 s. N. SCHLEIN METHOD AND APPARATUS FOR TWISTING WIRES Filed Sept. 20, 1961 4 Sheets-Sheet 1 m W wm w A mi u 5 S. N. SCHLEIN Oct. 6, 1964 METHOD AND APPARATUS FOR TWISTING WIRES Filed Sept. 20, 1961 4 Sheets-Sheet 2 W////////////////////////// R\\\\\ \m;

INVENTOR Fl'y-JE Seymour/l ch/21' 1 BY d. flu ATTORNEY 1964 v s. N. SCHLEIN 3,151,437

METHOD AND APPARATUS FOR TWISTING WIRES Filed Sept. 20, 1961 4 Sheets-Sheet 3 INVENTOR 5e Ymoaf 4 Sc file n F' .dE BY 19. My

# ATTORNEY Oct. 6, 1964 s. N. SCHLEIN METHOD AND APPARATUS FOR 'IVWISTING WIRES Filed Sept. 20, 1961 4 Sheets-Sh eet 4 INVENTOR Seymour- /Y h M ATTORNEY United States Patent Island Filed Sept. 20, 1961, Ser. No. 139,528 13 Claims. (Cl. 57--25) The present invention relates to a machine for twisting a group of wires in a zone of predetermined length substantially midway between its ends. It is particularly useful in conjunction with the preforming of a hard twisted portion on a half lay of preformed helical anchor rods.

In providing anchoring means for electrical conductors, it has heretofore been the practice to preform various lengths of round, hard resilient wires into open helices of a predetermined internal diameter. These helical wires are then assembled into groups to provide half lays. The groups maybe cemented together to provide a unitary half lay assembly. The half lay thus provided was then twisted by hand in a zone of predetermined length, usually midway between its ends to provide a full lay central zone which was of smaller diameter and having half lay end portions of the original open helix conformation. The structure thus provided may be utilized for various purposes. For instance, the hard twisted portion is bent to form a loop or bight which is secured to a suitable support, such as a pole or to an insulator on the pole.

The two half lay portions, which are arranged so that the open helices defined thereby are 180 out of phase with each other, are applied to a line or cable by first wrapping one leg of the dead end around the cable and then wrapping the other leg in position in the spaces left between the helices of the other leg.

The twisting of a half lay by hand is not only timeconsuming but is laborious and this is particularly true when relatively thick helical wires are used to form the half lay. Although a half lay is described, less or more than a half lay can be so twisted if desirable. Such an element, after being twisted, is illustrated in FIGS. 2, 3, and 4. As shown in FIG. 2, the open helical conformation at the ends is shown at A and the hard twisted center portion is shown at B. In actual practice, the parts A would be considerably longer than illustrated. The interior A of the part A has an internal diameter slightly less than that of the conductor or cable to which it is to be applied. The pitch of the individual elements may be the same as, slightly less than, or even longer than the pitch of the wires of the cable.

In accordance with the present invention, a machine is provided by means of which a half lay may be quickly twisted in a zone of a predetermined length substantially midway between its ends.

The invention will be better understood by reference to the accompanying drawings in which:

FIG. 1 is a side elevational view of a portion of my improved machine, with part of the machine broken away;

FIG. Zis an enlarged fragmentary elevational view of a twisted half lay as formed on the machine of the invention;

FIGS. 3 and 4 are sectional views taken from a plane from the lines 3-3 and 4-4, respectively, of FIG. 2;

FIGS. 5, 6, and 7 are cross sectional views taken from planes passing through the lines 55, 6-6 and 77, respectively, of FIG. 1, with the movable jaw of each clamp in open position;

FIG. 8 is a view of the clamping means shown in FIG. 7, with the movable jaw of the clamp in closed position;

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FIG. 10 is an enlarged cross sectional view taken from I a plane passing through the line 1ll-1ii of FIG. 7;

FIG. 11 is a cross sectional view taken from a plane passing through the line 11-11 of FIG. 1, looking in the direction of the arrows, with the movable jaw of the clamping means in open position;

FIG. 12 is an enlarged detail view of the movable clamping jaw shown in FIG. 13, with the movable jaw in closed position;

FIG. 13 is a view taken from a plane from the line 13-43 of FIG. 12;

FIG. 14 is an enlarged fragmentary elevational view of the right end of the machine of FIG. 1;

FIG. 15 is a detail plan view as seen from a plane in dicated by the line 1515 of FIG. 14 of the switches and cams for'controlling the operation;

FIG. 16 is a cross sectional view taken from a plane indicated by the line 1616 of FIG. 14;

FIG. 17 is a cross sectional view taken on a plane indicated by the line 17--17 of FIG. 14;

FIG. 18 is a side elevational view of a cam plate on a reduced scale;

FIG. 19 is a view, on an enlarged scale, of a switch and its operating cam; and

FIG. 20 is a wiring diagram of one type of circuit which may be used in connection with the machine to provide a certain form of operation.

Briefly, the invention contemplates a means whereby a preformed half lay may be laid in the machine and whereby the half lay is gripped at spaced apart positions in its mid-section and whereby the half lay is held at one of the positions and rotated at the other of the positions, resulting in the zone between the two positions being formed into a hard twist that provides a full lay. During the twisting, tension is exerted on the half lay which prevents the twisted portion from buckling. After being twisted, the machine is reversed automatically. During the reversal, the half lay is held for a predetermined number of revolutions before being released to prevent the half lay from whipping as it would if released immediately after twisting, due to the fact that the wire is highly resilient and must be slightly over twisted in the initial part of the operation to provide the final hard twist in the completed product.

Referring now to the drawings, throughout which like parts are designated by like reference characters, and more particularly to FIGS. 1 and 14, there is shown a bed 1 supported by legs 1a and having a supporting base 1b at its upper end.

At the extreme right of the machine, as viewed in the figures, there is provided a reversible motor 2 connected by a coupling 3 to a transmission 4, which comprises a reduction gearing. The output from the transmission 4 includes a shaft 5 which is connected to a drive head 6. The drive head 6 has extending outwardly therefrom toward the center of the machine, a plurality of drive rods 7 which are spaced apart from each other. Near one end of the rods 7 they support a first clamp member 8 and at the end they are connected to a second clamp member 9. The clamp means 8 and 9 are substantially identical.

The end clamp means 9 is rotatably supported in a bracket 12 of generally C-shaped form, securely fixed to the bed plate 1b by screws, not shown. The bracket is provided with rollers 14 secured on spindles 15 by nuts 16, the rollers thus extending outboard on the side toward the right or head end of the machine. Each of the clamp heads 8 and 9 are substantially the same, having a circular outer periphery provided with a throat opening 19. A sufiicien-t number of rollers 14 are provided that the head may be smoothly rotated within the supporting rollers.

Each of the heads has a fixed jaw 21) supported at the base of the throat in the, exact center of the head. Opposite to the throat the head is cut away at 21 to provide a space in which is supported the clamping mechanism. The clamping mechanism includes a clamp lever 22, which is supported on a pin 23 and extends through an opening in the narrow neck 24, with a clamp jaw 25 extending into the throat 1b and opposite to the fixed jaw 21). The clamp lever is rocked about its pivot 23 by toggle linkage 2d, 27, one end of which is pivoted on pin 28 in a recess 29 near the periphery of the head. The knuckle 3b is pivotally connected to the piston rod 31 of an air cylinder 32, the end of the cylinder being pivotally journalled on a pin 33 which bridges a pair of bosses 34 formed by providing an aperture 35 through the periphery of the cylinder. Thus, all of the operating clamping apparatus is confined substantially Within the confines of the sides of the head. As was stated, the heads are substantially identical but, as will later appear, a slight difference is provided in the clamp members 25a on the head 9 and 25 of the head 8.

To the left of the bracket 12 is the non-rotatable clamp means. As previously stated, the rotatable clamp means clamps and rotates the half lay while the non-rotatable clamp means holds the half lay against rotation and also exerts a tension on the half lay during rottion by the rotatable clamp means so that the hard twisted portion of the half lay does not buckle during the twisting operation. The non-rotatable clamp means includes a carriage 40, supported for longitudinal movement on the bed plate 112, by rollers 41. Lateral movement of the carriage on the bed is prevented by rollers 42, which extend downward alongside the edges of the bed plate 1b on each side thereof.

The rear end of the carriage 41) is provided with an upstanding bracket 43 to which the piston rod 44 of an air cylinder 45 is connected. The end of the air cylinder is anchored by a pin 46 to a bracket 47 supported by the bed plate 15. As will later more clearly appear, the air cylinder 45, being connected to the carriage 40, may reciprocate the carriage longitudinally on the plate 1b toward and away from the rotatable clamp head. Movement toward the clamp head is limited by an adjustable stop 48, which merely comprises a cap screw threaded through the upwardly extending arm 49 of a bracket 49a, which is adjustably secured to the bed plate 1b by screws, not shown. The stop screw 48 may be locked in position by the usual lock nut.

A pair of non-rotatable clamp members 50 are supported on top of the carriage 41) in adjustably spaced relation to each other. Hereafter, in the interest of brevity, these non-rotatable clamp members will be referred to as holding clamp members. Each of the holding clamp members comprises a generally rectangular frame having a fixed jaw 51 which is supported coaxial with the jaws 20 of the rotatable clamp member. As with the rotatable clamp members, the holding clamp member is provided with a clamp lever 52 connected to a toggle 43, 54, the end of which is anchored on a pin 55 in a recess in a lower right-hand corner of the frame, as viewed in FIG. 11. A piston rod 56 is connected to the knuckle of the toggle by a pin 57, the piston rod being operated by the air cylinder 58, which is pivotally anchored at 59 on a pair of bosses in the upper left-hand corner of the frame.

A bracket 43, secured to the end of the carriage 43, carries a V-shaped trough member 61 which provides a support for the half lay. This trough may be provided with an adjustable stop 62 which is one means for determining the postion of the half lay relative to the rest of the machine and prior to the twisting operation. An index rod 65 extends upwardly from the carriage 4t and is used for engagement with the half lay to properly index its position in the mechanism. An alternative means for determining the position of the rod in the machine comprises a cup it! supported by spokes 71 extending from sleeves 72 which are held in adjustable position on the rods 7 by set screws 73. The end of the half lay may be inserted into and bottom in the bottom of the cup. The cup is thus disposed axially of the clamping members and may be adjusted longitudinally to the proper position for locating the half lay.

As previously stated, the rotatable clamp members a are operated by the air cylinders 32. Air for the cylinders is supplied through a conduit 30, from a source not shown, to a rotatable joint 81 which connects to a conduit 82 that extends through the hollow spindle or shaft 5 and is connected by suitable connections 83, PEG. 5, to a solenoid valve 84, which is mounted on the head 6. The valve is of the solenoid type and may be one operated by single electrical impulses to supply air alternately to the lines 85, 36. Various types of valves may be used, and one which is satisfactory and well known is called the Bellows Bulletin 300, manufactured by The Bellows Company, of Akron, Ohio. The lines 85 and 86 are preferably of flexible tubing and may be releasably clamped by a ring 8'7 to one of the drive rods '7. Adjacent the heads 8 and 9 T connectors $8 and 89 are provided having branched lines 93 and 91 extending therefrom, which connect to opposite ends of the cylinders 32. It will thus be seen that the solenoid and the air lines rotate together with the drive head 6, drive rods 7 and the heads 8 and 9.

Current for operating the solenoids is supplied through the cable to a brush assembly 101, the brushes of which engage with contact or slip rings 2 carried on an insulated bushing 133 disposed about the hollow shaft 5. The rings 162 are connected by wires 152 and 184 to the solenoid valve 84. The connection is such that when the solenoid valve is operated in one direction, the piston rod 31 of the cylinder is retracted to operate the levers 22 to open position and, when operated in the other direction, the piston rod is extended to move the levers 22 to a closed position. The two positions are shown in FIGS. 7 and 8.

Air is also supplied through a line 30 and a branch line 111) to a pressure reducing valve 111 which supplies air to a first solenoid 112 which is in series with a second solenoid 112a connected to operate the air cylinder 45. The solenoid 112 is operated by current through the wire 152 simultaneously with the other valves. The second solenoid valve 112a is operated through the line 161 and through a branch line 152a controlled by a relay 152b of the delay type. A branch air line 115 from the main air line 30 connects to a solenoid 116 which is energized simultaneously with the solenoids 112 and 84, and which admits air to the lines 119 and 120 which are likewise connected to the cylinders 58 with a similar T coupling to that of the heads, to operate the cylinders 58 on the fixed jaw members.

As previously stated, the rotatable clamp members are arranged to clamp the half lay element securely to rotate and twist it. Each of the lever arms 22 is provided with a jaw 25 and 25a having welded thereto a pressure foot at least one of which is shaped to conform to the inner surface of the half lay. The jaws 25, 25a are adjustably held to the lever arms 22 by cap screws 22a. Preferably the gripping member 25 is in the form of a short cylindrical member having rounded ends the diameter of which is substantially the same as the inner diameter of the interior of the open helix A. Since the head 3 may be adjustably positioned relative to the head 9, the adjustment is such that the jaw on head 8 engages the bottom interior of the half lay at A and the jaw on the clamp 9 engages crosswise of the half lay at A". The half lay is thus securely gripped by the grippers, which first force the halp lay down, firmly into the sockets 20a of the fixed jaw members. The sockets Zda provide a semi-circular seat which conforms substantially to the outer surface of the half lay A, therefore, the half lay is gripped securely at these two points without deformation.

The two fixed jaw gripping members 50 may be arranged to grip the half lay in a similar manner. The jaws 52!: are arranged in a similar manner with the jaw next to the twisting zone crosswise to the half lay and the other jaw seated in the interior. Like the heads 8 and 9, the heads 50 may be adjustably spaced so that the interior of the half lay is engaged at C" and crosswise at C, to the left of the zone B, and immediately adjacent where the half lay is to be twisted. The gripping elements which extend crosswise of the half lay, may be made of a material which does not mar the rods, such as nylon. The ones that seat in the interiors are preferably of a hard material.

The operator takes a half lay of preformed elements and inserts it through the throat of the fixed and rotatable jaws, laying the same in the fixed jaws 20 and 51. The end of the half lay may engage and bottom in the cup 70 or alternately the other end engage against the adjustable stop 62 in the trough 61. Only one of these elements are used at one time and the one used is adjusted so that the heads, both the fixed and rotatable, are disposed immediately adjacent to where the twisted zone B is to be made, at opposite ends of the zone.

Proper circular orientation of the half lay is provided so that the clamps will properly engage therewith. The operator pulls the half lay into engagement with the rod 65, which engages with the transverse extremities of the interior convolutions of the half lay.

The half lay is then gripped by the fixed jaws and rotated by the rotatable jaws upon energization of the motor 2. Adjustable timing means, later described, is provided whereby the motor can be made to rotate a desired number of revolutions, or fractions thereof, in one direction to twist the half lay, then stop and revolve in the reverse direction, back to the place where it started;

The performance of the twisting or untwisting operation, once the machine is started into a cycle, is all automatic. The number of revolutions of the head and the control of the air solenoids are all coordinated to provide the desired results. It will be appreciated, however, that other types of controls than those illustrated can be designed to perform the same function and work equally well with the machine. One particular apparatus contemplates having a gear 120 on the spindle 5 in mesh with a smaller gear 121, which is mounted on a lead screw 122 journalled in pillow blocks 123. The pillow blocks are in turn mounted on a sub-base 124 above the main base 112. The lead screw has a nut 126 journalled thereon and carries a plate 127. The plate is provided with longitudinally extending slots 128 in which are adjustably mounted switcfi operating cams 129. The bottom edge of the plate 127 rides in a guideway 13%. It may thus be reciprocated in a longitudinal direction alongside the lead screw 122 to move all of the cams simultaneously.

Opposite to the plate 127, at the edge of the base 124, a switch support plate 131 is secured to an angle member 132 and carries in aligned spaced relation thereto a plurality of switches such as 134a, 134b and 1340. Since the lead screw is driven through the reduction gearing by the motor, the nut 126 travels in timed relation thereto and the cam carrying plate is carried past the switches to actuate them in the proper order. The' switches each have an operating lever 140 which operates an actuating pin 141. Preferably the switches are of the type which only operate upon movement of the cam past them in one direction. The end ofeach switch lever is provided with a pawl 142 having an arm 143 in spring pressed engagement with the underside of the lever 140, the construction being such that the pawl 142 is pivoted when the cam 129 passes in one direction, as best shown in FIG. 19, but when engaged by the pawl in the other direction causes the switch to operate. Thus the cams may be arranged to operate the switches in only one direction, which can be in either direction depending upon the way the switch is mounted.

The operation of the device will be explained in conjunction with a certain type of operation which enables improved results to be obtained. This operation may be varied in practice to suit the occasion. The simplified wiring diagram illustrated in FIG. 20 illustrates a form of control for operating upon one particular size and type of Wire. It should be appreciated that the manner of controlling the machine can be effected in many ways. The sequence of the operation, which will lead to a better understanding of the diagram as well as the operation of the machine, involves the starting of the machine by actuating a starter button 150. The starter button controls two circuits.

The lines L1 and L2 are energized by direct current from a source not shown. The start switch 150 is mounted on the bed 1b opposite the rotatable clamp jaws in position for convenient actuation by the operator. When the button is pushed, a first movable contact 151 makes a connection between the line L1 and a conductor 152. The line L2 may be permanently grounded. The circuit is then through one of the slip rings 102 via a winding 153 on solenoid valve 84 to ground. This causes both of the cylinders 32 on the rotary heads to close the clamp jaws, securely gripping the half lay.

Simultaneously current is supplied to the Winding 154 of solenoid valves 116 to cause the operation of the holding jaw cylinders 58 actuating the holding jaws to a closed position on the half lay.

At the same time, current is supplied to the winding 190 of a starter solenoid valve 112 which is disposed in series with the carriage control valve 112a, and through the closed contacts of the relay 152k and the line 152a to the lower winding 155a to operate the valve 112a to admit air to the rear of the cylinder and to cause the rod 44 to push the carriage 40 toward and against the stop 48. The movement of the carriage to the right foilows the clamping of the half lay because the cylinder 45 .is a larger cylinder and it takes more time for the pressure to become effective. The longitudinal movement of the carriage 40, in this instance, although slight, causes the half lay to be securely seated and settled in the gripping aws.

Continued pressure on the start switch button causes the switch blade to close the circuit to the line 161. This furnishes current through the line 163 to a relay coil 162, which is grounded to line 164 and causes the armature 162a to operate the switch blades a to f inclusive. The switches a to e inclusive close and the switch 1 opens. Switches a and I; close a circuit between the lines L1 and L3 to the motor armature 2 through the lines 169 and 170. Switches 0 and d close a circuit through the lines 167 and 168 to the field winding 166. Switch 6 closes and completes a circuit from line L1 through line and normally closed switch 134a to coil 162 and thus provides a holding circuit which keeps the relay locked in when the switch 150 is released. At this time the motor starts and rotates the heads 3 and 9 in a clockwise direction, as viewed from the right end of FIG. 1.

Should the half lay be the opposite hand of pitch to that shown in FIG. 2, a polarity reversing switch in lines L1 and L2, not shown, would simply be used to reverse the polarity of the lines L1 and L2 and the same operation being described would be carried out, with the direction of operation of the motor reversed.

At the same time as the motor starts, a current is supplied to the winding 155 of solenoid valve 112a, through the line 161 which reverses the pressure in the cylinder 45, air being admitted at the opposite end to exert tension on the carriage 40 and on the half lay. The tension or pressure on the carriage is determined by the setting of the reducer valve 111 and is determined empirically. during operation and is of sufiicient tension to prevent kinks or buckling of the wires in zone B and to assist in forming a hard twist during the twisting operation. At this time the relay'lSZb is also operated to open the line 152-1521: to the coil 155a of the solenoid valve 112a.

When the motor starts, the timing shaft 122, which is driven by the gears 129421, also starts to rotate and the nut 126 with the plate 127 and its operating cams 129 is slid along opposite to the switches 134a, 1341? and 1340. The first movement of the cam plate causes an immediate closure'of the switch 134b, which is a normally closed switch. Nothing happens in this circuit, however, because the switch is open.

As previously stated, the. number of revolutions for twisting the half lay will vary, depending on the diameter of the half lay, the size of the wires and the length of the zone to be twisted. The wires normally being a hard resilient material, the material is preferably slightly over twisted to make it take the desired set. When it is re leased, it will untwist to some extent and remain in the desired state.

If the wires or rods were released immediately after being twisted, there would be a tendency for the rods to Whip and result in possible injury to the operator. Therefore, the motor is reversed a predetermined number of revolutions before the rods are released, to relieve the torsional strains.

After the desired number of revolutions in a clockwise direction, the motor is stopped and reversed. This is brought about by one of the cams 129 engaging the switch 134a to open the circuit. This deenergizes the holding coil 162 and the contacts a, b, c and d are opened deenergizing the field 166. The contact closes at the same time.

Upon the closure of contact 1, a circuit is made to the holding coil 180 through the lines 181 and 182 connectting through the closed switch 134b to line L1, which energizes the coil 180 and closes the switches g, k, m and n. The closure of these switches results in a reversal of current in the motor which stops quickly and reverses, rotating in the counter clockwise direction and starting to untwist the half lay. At the same time the motor stopped, the line 161 which connected to line 153, became deenergized, and the line 181a to the coil 19% of solenoid valve 112 was energized to shut off the air to cylinder 45.

The nut 126, with its cam plate, is now traveling in the other direction and after a predetermined number of revolutions of the head, one of the cams 129 engages with the actuator of switch 1340 to momentarily close the switch which supplies a pulse of current from the line L1 through the conductor 184 and slip ring 102a by way of a conductor to the coil 153a of the solenoid air valve 84. At the same time the other coils for valve 154 are energized. This causes all the clamp means to open, releasing the half lay.

The reverse revolutions continue, the cam plate and its cams moving back toward its original position. Eventually the switch 134]) is operated, which opens the circuit to the holding coil 186, and the motor stops.

The stopping occurs with the throats in the rotary gripping members being aligned with the opening into the bracket 12, as shown in FIG. 17. The twisted half lay is then removed and replaced by another untwisted half lay and the process repeated.

A typical cycle of operation may involve five movements of the carriage 49, all of which are desirable to produce a uniform product, although in some instances some of the movements may be omitted.

The rod is first clamped by the clamping means. This occurs very quickly after the solenoid is operated to admit air to the cylinders 32 and 53, because these cylinders are small. At the same time pressure is admitted to the rear of the cylinder which, because of its larger volume does not become effective as quick as the clamp cylinders. This causes a first movement of the carriage 40 to the right, pushing it tightly up againstthe stop 48-49. This assists in seating the clamps securely on the half lay. Almost immediately after this occurs the heads 8 and 9 start to rotate. Immediately after the rotation starts, the valve 112a is operated in the opposite direction to admit air to the front end of the cylinder which starts pulling the carriage toward the left end of the. machine, this being a second movement of the carriage.

During the twisting operation, the. desired pressure is maintained in the cylinder 45 to exercise the desired amount of tension on the wires. As the wires twist up, a third movement of'the carriage to the right occurs, which is a secondary movement due to the twisting of the wires which cause the twist zone to be shortened. At this time the carriage 40 moves to the right against the pressure exerted by the cylinder 45. it should be noted that the pressure in the. cylinder should-be such that this movement can occur since it aidsin enabling a hard, closely wound twisted zone to be made without unduly stretching the wires.

When the rotary. heads reverse, there is a fourth movement of the carriage to the left, due to the untwisting of the previously slightly overtwisted zone. After the desired. amount of untwisting occurs, the pressure in the cylinder 45 is released and the fifth movement of the head to .the right occurs since the release of tension on the twisted zones causes the wire to pull the head back toward its original position.

The machine is also useful in the manufacture of rods where the center zone B is of larger diameter than the ends zones. Such rods are useful in conjunction with the making of line splices where the smaller diameter helices atone end are first wrapped around the line and then the enlarged part, over the splice and finally the remaining smaller diameter helices wrapped around the line the other side of the splice. The parts are wrapped around the line usually have the same or shorter pitch and the same lay asthe line and are of slightly smaller diameter in order. that. they grip the line tightly. The part that bridges the splice, which can be any of theconventional type of splice units, has-a considerably larger inside diameter to the helix than the end parts.

The manufactureof the above is carried out by placing the rods in the machine the same as described in the first operation. However, instead of twisting the rods, they are now untwisted by rotating the head in the opposite direction to the direction of the lay. During the untwisting operation pressure is applied to push the ends of the zone B toward each other and thispressure causes the helix to beenlarged. As in the twisting operation, the untwisting is continued until the enlargement is slightly larger thanthe finished produce in order that the ultimate permanent set, when the rods are released, will be of the desired amount.

When the machine is usedto cause an untwisting and enlargement of the helices, the operation is substantially a reversal of the twisting operation. In this instance, the wire are gripped at the ends of the zone to be untwisted. At this time the carriage 40, with its holding heads 50, is spaced away from the stop 48-49. At the start of the operation a slight pull is first applied to the wires which assist in seating the clamp on the wires. Then as the'r'otation of theheads starts in the opposite direction, air is admitted to the rear of the cylinder. The combination of endwise pressure on the wires and the untwisting action of the rotary head causes the wires to bulge outwardly and assume a lesser pitch. The movement continues until the wire is untwisted slightly beyond the desired amount because, when it is released, it will collapse to a certain extent. After a predetermined number of rotations'of the head, it is then reversed and then the pressure is released after which the wire is released and the head continues its rotation to the normal position.

It is apparent that the construction of the machine is such that various modifications of the controls may readily be made and thus the machine programmed to provide any desired form of operation.

The circuit shown and described merely shows one manner of its operation and has been simplified in order to more clearly show the versatility of the machine. For instance, it has been illustrated as using direct current throughout. In actual practice, the lines L1 and L2 would be used merely to supplydirect current to the motor and the various solenoids and relay coils would be operated by stepped down alternating current at a much lower voltage, such as 6 or 12 volts.

Likewise the cams 129 and switches 134a, 134b and 134s could be placed in different positions than that shown, and, the number of cams and switches increased to provide the desired programming. For instance, limit switches would normally be provided at the extreme limits of movement of the cam plate 127, disposed in the motor circuit to cut ofi the motor in event of failure of the pro gramming switches to operate.

The drive of the rotary head through the torsion bars 7 provides several advantages. One of the advantages resides in the fact that they provide a drive to the heads with a certain amount of resiliency which prevents extreme shocks to the head and the product.

It also permits quick and easy adjustment of the rotary heads relative to each other and this enables the machine to operate upon a wide range of different pitch helices. This adjustment feature is also facilitated by having the clamping mechanism disposed substantially within the lateral confines of the head so that they may be brought very close together when helices of short pitch are being twisted or untwisted.

The provision of two different gauges 70 and 62 for placement of the wires allows the most convenient one to be used.

Having thus described my invention in an embodiment thereof, I am aware that numerous and extensive departures may be made therefrom without departing from the spirit of the invention as defined in the appended claims.

I claim:

1. A machine for twisting a partial lay of open helically preformed wires in a zone intermediate its ends into a hard twisted full lay, said means comprising a first clamping means movable into firm clamping engagement with the wires of the partial lay at one position and a second rotatable clamping means movable into firm clamping engagement with said partial lay of wires at a spaced distance from the first clamping means, means for rotating the second clamping means relative to the first clamping means to twist that portion of the partial lay between the two clamping means to provide a hard twist full lay.

2. A machine as described in claim 1, wherein means is provided for moving one of the clamping means, under tension, away from the other to apply tension to the portion of the wires being twisted.

3. A machine as described in claim 2, wherein said rotating means is reversible to rotate said clamping means in the opposite direction to remove the torsional strains in the twisted portion of the wires.

4. A machine for twisting a portion of a half lay of wires of open helical formation into a hard twisted full lay comprising a first and second clamping means movable into firm clamping engagement with the inner and outer surfaces of said half lay at a spaced distance from each other and the ends, and means for rotating one of said clamping means relative to the other to twist the zone of the half lay between the clamping means to a sufficient extent to produce a full lay zone intermediate the half lay end portions.

5. A machine for twisting a portion of a half lay of preformed wires to open helical formation into a hard twisted full lay zone intermediate its ends, said machine including means for holding the half lay against rotation including a first clamping means arranged at a predetermined distance from one end of the half lay and including a frame having a seat therein for receiving the outer surface of the half lay, a clamp for engaging the interior of the half lay, a second rotatable clamping means spaced from the first clamping means including a support having a seat therein for receiving the outer surface of the half lay, a clamp for engagement with the inner surface of the half lay, means for rotating the second clamping means relative to the first clamping means including a driving shaft, a base connected to the driving shaft, and a plurality of spaced bars connected to said base and the second clamping means for rotating the second clamping means to twist the half lay between the clamping means, means for applying tension to that portion of the half lay between the first and second clamping means while it is being twisted to prevent buckling and to enable the twisted portion of the half lay to be formed into a full lay having compact smooth convolutions, said driving means being reversible to release the strains in the twisted portion of the half lay, and means releasing said clamps to enable the half lay'having the twisted midportion to be released from the machine.

6. A machine for twisting a plurality of wires of preformed open helical formation assembled into a group of less than a full lay into a hard twisted full lay zone intermediate its ends including means for holding said wires adjacent the zone to be twisted comprising a frame having a seat of engagement with the exterior of the wires and clamp means movable into the interior of the helices to press the wires against the seat, a second pair of rotatable clamp means each comprising a rotatable frame having a seat for engagement with the exterior of the wires and clamp means movable into the interior of the helices for pressing it into clamping engagement with the seat, reversible means for rotating the rotatable clamp means to twist said wires into a zone between said clamp means comprising a rotatable base member, torsion bars extending from said base member and connected to said rotatable clamp means.

7. A machine for twisting or untwisting a plurality of wires of preformed open helical formation assembled into a group intermediate its ends including a pair of means for holding said wires adjacent the zone to be twisted or untwisted, each comprising a frame having a seat for engagement with the exterior of the helices and clamp means movable into the interior of the helices to press the wires against the seat, a second pair of rotatable clamp means each comprising a rotatable frame having a seat for engagement with the exterior of the helices and clamp means movable into the interior of the helices for pressing it into clamping engagement with the seat, reversible means for rotating the rotatable clamp means to twist or untwist said wires in a zone between said clamp means comprising a rotatable base member, torsion bars extending from said base member and connected to said rotatable clamp means.

8. A machine as described in claim 7, wherein each of said pair of said holding means is adjustable toward and away from each other to enable the clamp means to engage with adjacent convolutions of said helices.

9. A machine for twisting a plurality of wires of preformed open helical formation assembled into a group of less than a full lay in a zone intermediate their ends into a hard twisted full lay comprising a first clamping means and a second clamping means arranged to grip said wires at the boundaries of the zone to be twisted, a bed, a carriage reciprocably mounted on the bed, pneumatic tension means connected to said carriage to move it in opposite directions, said first clamping means being mounted on the carriage and comprising first and second clamp members one of which is adjustably mounted on the carriage for adjustment toward and away from the other, a support means mounted on said bed and said second clamping means comprising a pair-of clamp .meansone of which is rotatably mounted in said support .means, drive means for rotating said second clamping means comprising a motor, a drive plate rotatably connected tosaid motor, a plurality of torsion bars connected between said drive plate and one of said second clamp means, the other of said second clamp means being adjustably mounted upon said torsion bars for adjustment toward and awayfrom'the other.

10. A machine for twisting a plurality of wires of preformed open helical formation assembled into 'a group of less than a full lay in a Zone intermediate their ends into a hard twistedfulllay comprising a first clamping means and a-second clamping means arranged to grip said wires atthe boundaries ofthe zone to be twisted, a bed, a carria'ge reciprocably mounted on the bed, means for exerting resilient tension connected to said carriage to move .it in opposite directions, said first clamping means being mounted'on the carriage and comprising first and second clamp members one of which is adjustably mounted on the carriage for adjustmenttoward and awayfrom the-other .to clamp said Wires in adjacent helices, 'a-supportmeans mounted on said bed and said second clamping means comprising a pair of clamp means one of which is'rotatably mounted in said support means, drive means for rotating said second clamping means comprising a reversible motor, a drive plate rotatably connected to said motor, a plurality of torsion bars connected between said drive ,plate and one of said second clamp means, the otherof said second clamp meansbeing adjustably mounted upon saidtorsion bars for adjustment toward and away from the other to clamp said wires in adjacent helices.

11. A machine as-described in claim 10, wherein control means :is provided connected to said motor and to said clamping means and tension/means'to operate them in timed relation to each other.

12.,A device as described in claim '11, wherein index means is provided on said carriage for engagement with References Cited in the file of this patent UNITED STATES PATENTS 556,203 Ordway 'Mar. 10, 1896 605,930 Stauffer June 21, 1898 939,308 Personett Nov. 9, 1909 2,414,136 Bodendieck i] an. '14, 1947 3,028,720 Honk Apr. 10, 1962 3,025,656 Cook Mar. 20, 1962 3,049,858 Bonds Aug. '21, 1962 3,052,079 Henning 'Sept. 4, 1962 3,052,081 'Wallshein Sept. 4, 1962

Claims (1)

1. A MACHINE FOR TWISTING A PARTIAL LAY OF OPEN HELICALLY PREFORMED WIRES IN A ZONE INTERMEDIATE ITS ENDS INTO A HARD TWISTED FULL LAY, SAID MEANS COMPRISING A FIRST CLAMPING MEANS MOVABLE INTO FIRM CLAMPING ENGAGEMENT WITH THE WIRES OF THE PARTIAL LAY AT ONE POSITION AND A SECOND ROTATABLE CLAMPING MEANS MOVABLE INTO FIRM CLAMPING ENGAGEMENT WITH SAID PARTIAL LAY OF WIRES AT A SPACED DISTANCE FROM THE FIRST CLAMPING MEANS, MEANS FOR ROTATING THE SECOND CLAMPING MEANS RELATIVE TO THE FIRST CLAMPING MEANS TO TWIST THAT PORTION OF THE PARTIAL LAY BETWEEN THE TWO CLAMPING MEANS TO PROVIDE A HARD TWIST FULL LAY.

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