US3842728A

US3842728A - Device for tying coils of wire

Info

Publication number: US3842728A
Application number: US00348617A
Authority: US
Inventors: H Elineau
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-03-09
Filing date: 1973-04-06
Publication date: 1974-10-22
Anticipated expiration: 1991-10-22
Also published as: FR2174751A1; FR2174751B1; IT981173B

Abstract

A tie-wire is placed around a coil of wire, then twisted and knotted by means comprising at least one mandrel which is capable of both translational and rotational motion and adapted to receive the two ends of the tie-wire, and at least one back-plate for holding the tie-wire in position during rotational motion of the mandrel, the back-plate being placed opposite to the mandrel head.

Description

United States Patent 1191 Elin'eau Oct. 22, 1974 [54] DEVICE FOR TYING COILS 0F WIRE 3,195,444 7/1965 lzivcLean 100 12 x 3,44 80 6 1969 b 100 X [76] Inventor Elma, 9 rue Exelmans 3,633,292 111972 oiiua r 1 0 0/7 Versaflles, France 3,678,845 7/1972 Francois 100/12 x [22] Filed: Apr. 6, 1973 2 A N .3 34 17 Primary ExaminerBilly J. Wilhite I] pp 0 8 6 Attorney, Agent, or FirmYoung and Thompson [30] Foreign Application Priority Data May 23, 1972 France 72.8273 ABSTRACT [52] U S Cl 100/7 100/3 100/12 A tie-wire is placed around a coil of wire, then twisted Ibo/31 140/93 and knotted by means comprising at least one mandrel [51] Int Cl which is capable of both translational and rotational [58] Fie'ld 7 12 'motion and adapted to receive the two ends of the tie- 6 wire, and at least one backfplate for holding the tiewire in position during rotational motion of the man- 56] References Cited drel, the back-plate being placed opposite to the man- UNITED STATES PATENTS drel head 2,674,181 4/1954 Jones 100/12 14 Claims, 18 Drawing Figures PATENIEDumzzmm SHEET 70$ 7 DEVICE FOR TYING COILS OF WIRE This invention relates to a device for tying coils of wire produced in metallurgical plants.

In known devices of this type, tongs can be displaced in a direction parallel to the axis of the coil both outside for guiding troughs in which the wire is displaced towards a twisting head.

These machines are subject to a certain number of disadvantages: positioning of the tie-wire usually takes a fairly long time which is virtually incompatible with the rate of production of coils to be tied.

Propulsion of the binding wire within guiding troughs causes strain-hardening which is in turn liable to result in failure of the wire at the moment of binding. Annealed wire can be employed in order to avoid this drawback but the tying operation in that case entails higher capital cost.

Moreover, the guiding troughs are subject to a high degree of wear and the systems employed for opening said troughs in order to release the tie-wire and apply this latter tightly around the coil are both complex and costly.

Finally, the mechanical strength of the binding hoops thus obtained and the appearance of the twisted ends are relatively unsatisfactory. In point of fact, said ends project to an excessive extent and are not turned back, are potential causes of accidents and complicate the handling of tied coils.

In the known devices, the coil is laid horizontally on a receiving cradle by means of a hook conveyor and a longitudinally moving carriage applies the coil against the tying system, an inclined plane being provided for the removal of the coil after tying.-

These devices are fairly slow and therefore do not prove wholly satisfactory.

The object of the invention is to overcome thesedisadvantages by providing a device which permits both rapid and reliable tying of coils.

'In accordance with the invention, the device for tying coils of wire and comprising means for placing a tiewire around a coil and means for twisting said tie-wire is characterized in that the means for twisting said tiewire comprise at least one mandrel which is capable of both translational and rotational motion and is provided with a head adapted to receive the two ends of the tie-wire, and at least one back-plate placed opposite to the head of said mandrel so as to maintain the tie-wire in position during rotation of the mandrel.

The device aforesaid serves to clamp the tie-wire between the mandrel and the back-plate whilst this latter remains stationary during the twisting operation.

In a preferred embodiment, the head of the mandrel and the back-plate are provided respectively with two radial grooves adapted to receive the tie-wire, the axes of the grooves of said back-plate being relatively displaced by the thickness of a tie-wire.

The grooves aforesaid receive the two ends of the tiewire to be twisted, the crossing of said ends being more readily performed by virtue of the fact that the grooves of the back-plate are relatively displaced.

In one advantageous embodiment, that face of the back-plate which is.directed towards the mandrel head is frusto-conical and the grooves of the back-plate are disposed along opposite generating-lines of the frustoconical surface and on each side of an axial plane of said surface.

In another embodiment, the back-plate is made up of two separable sections each having one groove and provision is made for arms which serve to support said two separable sections as well as means for causing said arms to rotate about a stationary pivot-pin.

In yet another embodiment; the device comprises binding arms fitted with jaws for gripping the end of the t tie-wire and pivotally mounted on a pin supported by a carriage, means being additionally provided for displacing said carriage in translational motion parallel to the axis of the coil and also for causing one arm to pass outside the coil and the other arm to pass inside said coil.

This last-mentioned arrangement makes it possible to pass the tie-wire over both the external face and the internal face of the coil.

In a preferred embodiment, a mandrel and a backplate are placed at each end of the coil.

. Said coil can thus be securely tied by forming a twistjoint at each end thereof. 7

In accordance with the method which is also provided by the invention for handling and compacting a wire coil, the coil is transported by means of a hook conveyor, placed on a receiving support, said support is lifted so as to reduce the load on the hook, the coil is compacted and tied, the support is lowered and the coil is removed by means of the hook.

This method makes it possible to maintain the conveying hook in position during the operations involved in compacting and tying and then to make use of the same hook for the removal of the coil without any loss of time.

Further properties and advantages of the invention will become apparent from the detailed description which is given hereinafter.

One embodiment of the invention is illustrated in the accompanying drawings which are given by way of example without any limitation being implied, and in which:

FIG. 1 is a longitudinal sectional view of the device, taken along line I.I of FIG. 14;

FIG. 2 is a partial longitudinal sectional view taken along line IIII of FIG. 14 and showing the binding arms in the closed position at one end of the coil prior to positioning of the tie-wire;

FIGS. 3 to 5 are views which are similar to FIG. 2 and show the successive positions of the binding arms;

FIG. 6 is a partial sectional view showing the twisting means of the device of FIG. 1;

FIG. 7 is a sectional view taken along line VIIVII of F IG. 2;

FIG. 8 is a partial view showing the clamping jaw of a binding arm;

FIG. 9 is a transverse sectional view showing the means for transmitting rotational motion to the twisting means of FIG. 6;

FIG. is a partial axial sectional view taken along line XX of FIG. 11; 7

FIG. 11 is a sectional view taken along line XI-Xl of FIG. 10;

FIG. 12 is a sectional view taken along line Xll--Xll of FIG. 11 and showing the cross-section of each mandrel groove;

FIG. 13 is a front view of the back-plate taken along line XML-XIII of FIG. 10;

FIG. 14 is a transverse sectional view of the device, taken along line XIV-XIV of FIG. 1;

FIG. is a longitudinal view, partly in section, showing the device for driving in translational motion the carriage which supports the binding arms of FIGS. 2 to 5;

FIG. 16 is a transverse sectional view taken along line XVI-XVI of FIG. 15;

FIG. 17 is a transverse sectional view taken along line XVIIXVII of FIG. 1 and showing the coil-receiving support;

FIG. 18 is a perspective view of a knot formed on completion of the twisting operation.

There will now be described in succession the means for compacting the coil, the means for positioning the tie-wire, the means for twisting the tie-wire, and the means for handling the coil. I

The device for tying a coil 7 of wire which is brought by the hook 8 of a conveyor comprises a stationary frame 1 (shown in FIGS. 1, 14, 17) having the shape of a rectangular parallelepiped.

There are placed at the ends of said frame 1 a stationary plate 2 mounted on a casing 10 and a compacting plate 3 attached to a moving carriage 11 which is mounted on wheels 12 and capable of displacement along guiding rails 4 under the action of a hydraulic compacting jack 5.

Runner-wheels 30 for transverse guiding of the carriage 11 (as shown in FIG. 17) are mounted beneath this latter and applied against the rails 4.

The plate 2 is of annular shape and has dimensions approximating to those of the cross-section of the coil 7.

A recess (not shown in the figures) is formed in the plate 3 in order that this latter can slide around the hook 8 when it is displaced in the direction of the casing 10 by the jack 5.

The device also comprises means for handling the coil 7.

Said means, which will be described in detail hereinafter, comprise two retractable supporting bars 20 which are intended to bear the weight of the coil 7 during the compacting and tying operations.

Referring now to FIGS. 2 and 14, it is apparent that the device comprises means for positioning a tie-wire 34 around the coil 7, that said means are placed within the interior ofa casing 10 (shown in FIG. 1) and comprise binding arms 13, each arm being capable of gripping a tie-wire 34 derived from a reel (which is not shown in the drawings). The tie-wire 34 is guided by horizontal and vertical rollers 35 and passes into a stretching and straightening system comprising rollers 36.

The arms 13 aforesaid are pivotally mounted on pins 14 which are supported by a carriage 15.

Four pairs of similar arms 13 are thus mounted at right angles within the casing 10 (as shown in FIG. 14).

The carriage 15 is attached to a central sleeve 16 which is slidably mounted on a stationary shaft 17. Said sleeve can be driven in translational motion around said shaft by means of a hydraulic jack 18 which is mounted on the frame 1 and connected to the sleeve 16 by means of an articulated lever or link-arm 19 and a yoke "21 (as shown in FIGS. 15 and 16).

When the operating rod of the jack 18 has completely withdrawn, the link-arm 19 takes up the position shown in chain-dotted lines and the sleeve 16 comes into a position of abutment at that end of the shaft 17 which is remote from the coil.

As shown in FIG. 2, provision is made for two connecting-rods 22 which are each pivotally attached at one end to a binding arm 13 in the vicinity of the pivotpin 14 and at the other end to a second carriage 23 which is capable of moving with respect to the first carriage. The carriage 23 is mounted on a collar 24 (FIGS. 2, 15) which is rigidly fixed to the sliding sleeve 16.

The body of a hydraualic jack 25 (shown in FIG. 15) is pivotally mounted on a member 26 which is rigidly fixed to the sleeve 16 and the operating rod of said jack is connected to the collar 24 in order topermit displacement of the carriage 23 and the collar 24 in trans lational motion with respect to the sleeve 16.

Elbowed levers 31 which are capable of rotating about a pin 32 under the action of hydraulic jacks 29 are mounted at the extremities of the arms 13 so as to form clamping jaws 33 in conjunction with said extrem ities, said jaws being capable of gripping a tie-wire 34 (see FIG. 8).

The arms 13 are elbowed substantially at right-angles (as shown in FIG. 7) so as to permit the insertion of four twisting heads.

The device comprises a group of four twisting heads on eachside of the coil 7.

The four heads of the first group are mounted at right-angles within the casing 10, each group being disposed between two binding arms 13, the four heads of the second group being placed opposite to those of the first group on the other side of the coil 7.

Each head comprises a mandrel 27 (as shown in FIGS. 2 and 14) which is associated with a back-plate 28 as shown in FIG. 6. The mandrel 27 is slidably mounted on an upright member of the frame. The end of the mandrel 27 which is remotefrom the back-plate 28 is in turn keyed in a pinion 42, said pinion being disposed in meshing engagement with a toothed driving fly-wheel 39 which is rotatably mounted on a stationary shaft 41.

Said fly-wheel 39 can in turn be driven in rotation by a jack 45 which is capable of actuating a lever 46, said lever being rigidly coupled for rotation with a toothed wheel 47 which engages with the fly-wheel 39.

A moving sleeve 43 is interposed between the stationary shaft 41 and the fly-wheel 39 and this latter is capable of rotating about the sleeve 43 by virtue of roller-bearings 44.

One end of a connecting-arm 48 is screwed into the sleeve 43; the other end of said connecting-arm is traversed by the terminal portion of the mandrel 27 and rigidly coupled for translational motion with this latter by means of a nut 49.

A hydraulic jack 51 is mounted on the frame 1 of the device in order to .permit displacement in translational motion parallel to the shaft 41 of the assembly which comprises the sleeve 43, the fly-wheel 39 and the mandrel 27, this latter being rigidly fixed to the two other components by means of the connecting-arm 48.

At the end of travel of the jack 51, the connectingarm 48 is stopped against an abutment member 40 which is held in position on the shaft 41 by means of a nut 50.

The back-plate 28 is retractable and made up of two similar and separable components 28a which are supported by clamping jaws 52, means being additionally provided for the purpose of displacing said jaws 52 in pivotal motion about stationary pins 53.

To this end, the jaws 52 are provided with arms 52;: pivotally mounted on pins 53 and adapted to carry rollers applied against a plate 54 which is slidably mounted on the mandrel 27. Provision is made for an elastic member constituted by a spring 55, one end of which is applied against an annular shoulder 37 of the mandrel 27 and the other end of which is applied against the plate 54.

Restoring springs 56 are attached to the clamping jaws 52 in order to maintain these latter at a distance from each other when they are not subjected to the action of the plate 54 under the pressure exerted by the spring 55.

The twisting means will now be described with reference to FIGS. to 13. The head of the mandrel 27 and the back-plate 28 have substantially circular transverse cross-sections and are provided respectively with two

radial grooves

57 and 58 which are adapted to receive the two end portions of the tie-wire 34, the axes of the grooves 58 of the back-plate 28 being relatively displaced by the thickness of the tie-wire (as shown in FIG. 13).

The face of the back-plate 28 which is directed towards the head of the mandrel 27 is of frusto-conical shape (as shown in FIG. 10) and the grooves 58 are disposed along opposite generating-lines of said frustoconical surface on each side of an axial plane 59 (FIG. 13) of said surface.

The head of the mandrel 27 has a central recess 61, radial grooves 57 being formed on each side of said recess in the line of extension of each other.

Each groove 57 has a sloping wall 57a (as shown in FIG. 12) and a wall 57b which is substantially perpendicular to the bottom of the groove, the object of the sloping wall 57a being to facilitate introduction of the tie-wire 34.

The peripheral portions of the head of the mandrel 27 which are located at the opposite ends of the grooves 57 are truncated so as to form recesses 62 in the mandrel 27.

On the mandrels 27 which are located within the casing 10, the edges of the recesses aforesaid are adapted to carry rotary knives 63 which are capable of cutting the tie-wire 34 in conjunction with stationary knives 64 placed in oppositely facing relation, the recesses 62 being intended to facilitate sharpening of the cut-off knives 63.

The mandrels which are located on the same side as the moving plate 3 do not carry cut-off knives since these latter are made unnecessary by the fact that the tie-wire 34 is already cut on this side.

The device in accordance with the invention further comprises means for handling the coil 7 as will now be described with reference to FIG. 17.

zontal bars for supporting the coil 7, said bars being attached to two pairs (only one of which is visible) of 'elbowed levers 65, 66 which are coupled for rotation with two horizontal shafts 67 mounted on the frame of the device.

The two shafts 67 aforesaid are rotationally coupled with two toothed wheels 68 which are disposed in meshing relation.

The lever 66 is provided with a terminal portion 66a and this latter is connected to the operating rod of a hydraulic jack 69 which is mounted so as to be supported on the frame 1.

When the jack 69 is actuated, the bars 20 can therefore be placed in the top position (shown in full lines) for supporting the coil 7 or in the bottom position which is designated by the reference 20a.

The cycle of operation of this device is as follows:

At the beginning of the cycle, the compacting carriage 11 which carries the moving plate 3 is located at the end of the frame 1 of the machine as-shown in FIG. 1 and the supporting bars 20 are in the bottom position 200 (as shown in FIG. 17).

The binding arms 13 are-closed in the position which can be seen in FIG. 2, the clamping jaws 33 (shown in FIG. 8) being open.

In their starting positions, the carriage 15 for supporting the arms 13 aforesaid and the driving sleeve 16 of the carriage 15 are located at the left end of the shaft 17 (as shown in chain-dotted lines in FIG. 15), the operating rod of the jack 18 being fully withdrawn.

The connecting-arm 48 of the sleeve 43 (shown in FIG. 6)'and of the mandrel 27 is applied against the abutment member 40, with the result that the mandrel 27 is set back with respect to the position shown in FIG. 6. Furthermore, the twisting jaws 52 are separated from each other (in the position designated by the reference 5217) and the moving plate 54 is located at 54a.

Finally, the operating rod of the jack 45 which serves to drive the fly-wheel 39 in rotation (FIG. 9) is retracted.

A coil 7 of wire suspended from a hook 8 is then introduced transversely between the casing 10 and the compacting plate 3 (as shown in FIG. 1).

The successive steps of the compacting and tying cycle are as follows:

a.,the jack 69 which serves to lift the supporting bars 20 (and which is shown in FIG. 17) is actuated so as to place said bars in the top position in which these latter support the coil 7.

The effect'thereby achieved is to lift the coil 7 to ashort distance above the conveying hook 8 (as shown in FIG. 14).

b. the compacting jack 5 shown in FIGS. 1 and 17 is actuated, with the result that the bars 20, the coil 7 and the carriage 11 are displaced towards the casing 10.

The recess formed in the carriage 11 and the plate 3 enables these latter to slide along the hook 8 which remains motionless.

The coil is therefore compacted by the plate 3 against the stationary plate 2 which serves as an abutment.

During this compacting operation, there is a slight increase in the diameter of the coil 7, with the result that the axis of said coil is lifted to an appreciable extent with respect to the arm 13 and that the good performance of the binding operation could consequently be impaired.

In order to guard against this danger, the pressure within the hydraulic jack 69 (shown in FIG. 17 is slightly increased with a view to lowering the supporting bars 20 so as to bring the axis of the coil back to its initial level.

c. A tie-wire is engaged in each pair of binding jaws 33 (shown in FIG. 8) and these latter are closed on the tie-wire 34 by actuating the jacks 29.

d. The jack 25 (shown in FIG. 15) is actuated, thereby moving the carriage 23 away from the carriage 15 which supports the binding arms 13.

The connecting-rods 22 then cause the arms 13 to open in a pivotal movement about the pins 14 and to take up the position shown in FIG. 3 while crossing the two corresponding tie-wires.

e. The jack 51 (FIG. 6) is actuated so as to cause displacement of this latter over approximately one-half of its total range of travel, with the result that the flywheel 39 and the mandrel 27 are moved away from the abutment member 40 and that said mandrel engages .52 and bringing together the two portions 28a of the back-plate 28.

f. The jack 18 (shown in FIG. 15) is actuated so that the carriage 15 which supports the binding arms 13 is driven in translational motion, the eight arms 13 are moved to the other side of the coil 7 and then placed in the position which can be seen in FIG. 4.

During this displacement, four of the arms 14 pass inside the coil 7 whilst the four other arms pass outside this latter, one tie-wire being carried by each arm.

g. The binding arms 13 are closed by means of the jack 25 (shown in FIG. 15), which places them in the position shown in FIG. and crosses the ends of the tiewires.

The eight tie-wires 34 now completely surround the coil 7 and are engaged within the grooves 58 (FIG. 13)

- of the back-plates 28.

h. The jack 51 is again actuated and completes its travel, thereby bringing the head of the mandrel 27 towards the back-plate 28. During this movement, the tie-wires 34 penetrate into the grooves 57 of the head of the mandrel 27 (as shown in FIGS. to 13).

The eight twisting heads are then ready to operate.

i. The binding jaws 33 which hold the tie-wire 34 (as shown in FIG. 8) are opened in order to release the wire.

j. The jack 45 (shown in FIG. 9) is actuated so that the toothed fly-wheel 39 and the mandrels 27 are thus caused to rotate. The velocity ratio between the flywheel 39 and the driving sleeves 42 of the mandrels 27 is chosen so that these latter perform a rotation in slightly more than one revolution.

-At the beginning of the rotation of the mandrel 27, the tie-wires 34 are cut on one side of the coil by the knives 63, 64. During the movement of rotation, the knot is formed within the interior of the central recess 61 of the mandrel 27 and fills said recess progressively.

When the movement of rotation is completed, the

twist-joint having turned-back ends is obtained as shown in FIG. 18.

k. The binding arms 13 are opened by means of the jacks 25 (shown in FIG. 15).

' I. Said arms 13are brought back to the other side of the coil 7 by means of the jack 18 (shown in FIG. 15).

Q i m. The eight twisting heads are returned by the jacks 51 to their position of starting in translational motion.

. pacting jack 5 (shown in FIG.'.l).

' At this point, the coil 7 again occupies the position shown in FIG. 1 and its elasticity has the effect of applying a high degree of tension to the tie-wires 34 and tightening these latter.

1'. The two bars 20 are lowered approximately to the mid-point of travel of the jack 69 (shown in FIG. 7) so as to place the coil 7 on the hook 8.

s. The return travel of the compacting jack 5 is completed and the coil 7 is removed by means of the hook 8 of the conveyor.

The compacting and tying device is then ready to begin afurther cycle.

It is readily apparent that the successive steps of the compacting and tying cycle can be rendered automatic by means which are known per se, the order for initiating the cycle being transmitted tothe device by the conveyor which supplies the coil.

A coil of wire hasthus been compacted and securely tied by forming at each of its extremities four twistjoints which are similar to the joint shown in FIG. 18 and spaced apart at angular intervals of The twist-joints formed in accordance with the invention are capable of withstanding the considerable residual forces applied by the compacted coil, which can attain 45 tons. By virtue of said twist-joints, the coils can therefore be handled in complete safety.

Moreover, the twist-joints have short and foldedback ends, which facilitates handling of coils by means of bridge transporters, cranes and the like and prevents any danger of accidents which could otherwise be caused by projecting ends of substantial length.

The device provided by the invention even offers further advantages:

the back-plates 28 make it possible at the outset to secure the tie-wire 34 and to carry out correct positional adjustmentpf this latter before it engages within the grooves 57 of the head of the mandrel 27. Said back-plates then hold the tie-wire 34 in position during rotational motion of the mandrel. Said back-plates 28 therefore ensure very reliable twisting and, in particular, removeany danger of faulty preliminary positioning of the tie-wire.

Withdrawal of the back-plates after formation of the twist-joint permits stretching of the tie-wires 34 under the action of the residual forces applied by the coil 7, thereby tightening the twisted ends against the coil.

The back-plates 28 aforesaid and the systems for operating these latter are relatively simple and inexpensive to construct.

The lateral introduction of the coil 7 within the machine and the method of compacting in accordance with the invention permit an appreciable saving of time. This arises from the fact that the conveying hook 8 remains in position during the compacting and binding cycle and can therefore remove the coil immediately after completion of the cycle without intermediate handling operations. The following coil can thus be placed in position without any loss of time.

Moreover, the time required to carry out the compacting and tying cycle proper is reduced to the minimum, with the result that the high production speeds encountered in modern metallurgical plants can readily be followed by the device according to the invention.

It will be understood that the invention is not limited to the example hereinabove described and can extend to alternative practical forms which come within the scope of the appended claims.

I claim:

1. A device for tying coils of wire and comprising means for placing a tie-wire around a coil and means for twisting and knotting said tie-wire, wherein the means for twisting the tie-wire comprise at least one mandrel which is capable of both translational and rotational motion and is provided with means for receiving the two ends of the tie-wire, and at least one backplate for holding the tie-wire in position during rotation of the mandrel, said back-plate being placed opposite to the head of said mandrel.

2. A device according to claim 1, wherein the head of the mandrel and the back-plate are provided respectively with two radial grooves adapted to receive the tie-wire, the axes of the grooves of said back-plate being relatively displaced by the thickness of said tiewire.

3. A device according to claim 2, wherein the backplate face which is. directed towards the mandrel head is frusto-conical and wherein the grooves of said back plate are disposed along opposite generating-lines of the frusto-conical surface and on each side of a plane of said surface.

4. A device according to claim 1, wherein the backplate is retractable.

5. A device according to claim 4, wherein the backplate is made up of two separable sections each having one groove.

6. A device according to claim 5, wherein said device comprises jaws for supporting the two separable sections of the back-plate and means for causing said jaws to rotate about a stationary pivot-pin.

7. A device according to claim 6, wherein the jaws are'provided with arms applied against a plate which is slidably mounted on the mandrel, provision being made for an elasticmember which serves to transmit the translational movement of the mandrel to said plate.

8. A device according to claim 1, wherein the means for positioning the tie-wire comprise binding arms equipped with means which serve to grip the end of said tie-wire and are rotatably mounted on a pivot-pin supported by a first carriage which is capable of displacement in translational motion, means for displacing said carriage in a direction parallel to the axis of the coil and adapted to cause one arm to pass outside the coil and the other arm to pass inside said coil, and means for causing the said arms to rotate about their pivot-pins.

9. A device according to claim 8, wherein the means for displacing the first carriage in translational motion comprise a sleeve which is rigidly fixed to the carriage and capable of moving about a stationary shaft, and a hydraulic jack connected to the sleeve and mounted so as to be capable of driving said sleeve in translational motion.

10. A device according to claim 8, wherein the means for causing the arms to rotate about their pivot-pins comprise two connecting-rods such that one end of each connecting-rod is pivotally attached to one arm and the other end is pivotally attached to a second carriage which is capable of moving with respect to the first carriage.

11. A device according to claim 10, wherein said device comprises means for handling and compacting the coil.

12. A device according to claim 11, wherein the means for handling the coil comprise two coilsupporting bars and means for withdrawing said bars and allowing the coil to rest ona conveying hook.

13. A device according to claim 12, wherein the means for withdrawing the bars comprise two elbowed levers coupled for rotation with two shafts, and a hydraulic jack mounted so as to control the rotation of said shafts.

14. A device according to claim 13, wherein at least one mandrel and one back-plate are disposed at each end of the coil in order to twist the tie-wire at both ends Patent; NO, 3,842,728 Dated October 22, 1974 Inventor(s) Hubert E1 lneau It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below;

On the cover sheet item [30] "72.8273" should read Signed and sealed this l lth day of FebTuary I975.

QSEAL) Attest:

RUTH C MASON C. MARSHALL DANN Commissioner of P t Attesting Officer and Trademaikz USCOMM-DC 603 76-P69 u.s. GOVERNMENY PRINTING orncz: 69 93o FORM PO-IOSO (10-69)

Claims

1. A device for tying coils of wire and comprising means for placing a tie-wire around a coil and means for twisting and knotting said tie-wire, wherein the means for twisting the tiewire comprise at least one mandrel which is capable of both translational and rotational motion and is provided with means for receiving the two ends of the tie-wire, and at least one back-plate for holdIng the tie-wire in position during rotation of the mandrel, said back-plate being placed opposite to the head of said mandrel.

2. A device according to claim 1, wherein the head of the mandrel and the back-plate are provided respectively with two radial grooves adapted to receive the tie-wire, the axes of the grooves of said back-plate being relatively displaced by the thickness of said tie-wire.

3. A device according to claim 2, wherein the back-plate face which is directed towards the mandrel head is frusto-conical and wherein the grooves of said back-plate are disposed along opposite generating-lines of the frusto-conical surface and on each side of a plane of said surface.

4. A device according to claim 1, wherein the back-plate is retractable.

5. A device according to claim 4, wherein the back-plate is made up of two separable sections each having one groove.

7. A device according to claim 6, wherein the jaws are provided with arms applied against a plate which is slidably mounted on the mandrel, provision being made for an elastic member which serves to transmit the translational movement of the mandrel to said plate.

12. A device according to claim 11, wherein the means for handling the coil comprise two coil-supporting bars and means for withdrawing said bars and allowing the coil to rest on a conveying hook.

14. A device according to claim 13, wherein at least one mandrel and one back-plate are disposed at each end of the coil in order to twist the tie-wire at both ends of said coil.