WO1982003368A1

WO1982003368A1 - Device for twisting a binding metal wire

Info

Publication number: WO1982003368A1
Application number: PCT/FR1982/000057
Authority: WO
Inventors: Rene Grenon
Original assignee: Rene Grenon
Priority date: 1981-03-26
Filing date: 1982-03-23
Publication date: 1982-10-14
Also published as: EP0074985A1; BR8207245A; AU8272482A; EP0074985B1; JPH0132085B2; FR2502582A1; SU1435148A3; IT1151528B; JPS58500248A; IT8220435A0; DE3260568D1; US4508030A; AU552426B2

Abstract

Two pliers (17, 18) are arranged to clamp and hold the wire in the throat of the wire guide (19) at the vicinity of the rotary head (1) which is associated to a stop (12) for stopping the wire and to a shearing means (13) and which has a central clearing (4) open in the direction of the object (S) to the bound in which inclined radial passages (2, 3) for the wire open, of which the ends are twisted during the rotation of the head (1) to form a twist of which the configuration is imposed by the inner configuration of said central clearing (4).

Description

Wire twisting device for ligature.

The invention relates to a device for twisting the two end parts of a metal wire used as a ligating means.

We already know many devices having the same role. The state of the art can be illustrated in this field by the following patents: DE 1,511,828 - US 3,470,813 US 4,252,157 - FR 1,576,602. With most known devices, at the time of twisting, the stresses in the two ends of the binding wire are different which causes asymmetry of the twist and a decrease in resistance. On the other hand, these devices include clamps for holding the ends of the binding wire which are placed beyond the twist with respect to the linked object so that the execution of the twist often leads to a elongation of this wire, elongation which can be excessive, which can cause necking and further decrease the resistance. In addition, as the ends are held in the clamps, it is necessary to then fold them back against the linked object, after execution of the twist.

Finally, the tying yarn used necessarily has a length greater than the value strictly necessary to carry out the twisting itself.

The main object of the invention is to provide a device which performs a twist of the two ends of a metal link without imposing additional lengthening on this wire, using the length of wire strictly necessary, and which removes all need to fold the ends of the twisted wire or to fold the twist itself.

In a device for twisting the two end parts of a wire serving as a link around an object, comprising a grooved wire guide with a fixed part containing a rotary twisting head having two opposite inclined passages starting from the face lateral of this head in extension of the groove in a stop position of said head,

WIPO according to the invention two opposite clamps are arranged to immobilize respectively the end parts of the wire in the wire guide near the head and the latter has a hollow central clearance open towards the interior of the wire guide, in which open the opposite inclined passages, this central clearance having an interior configuration suitable for the twist to be produced.

A stop is arranged opposite the external opening of a passage and a shearing means is arranged symmetrically in correspondence with the external opening of the opposite passage.

Preferably, the length of the passages is finished so that the wire is sheared to the exact length necessary for making the twist. According to one embodiment of the invention, the means of shearing consists of a fixed part of the thread guide in which is drilled a guide channel of the wire in prolongation of the corresponding passage and each clamp comprises _^ on the one hand respectively fixed part of the wire guide, on the other hand a movable jaw able to immobilize the wire in the groove of the wire guide.

In a preferred embodiment of the invention, the hollow central clearance is terminated by a flat transverse bottom to a depth equal to the length of the desired twist and it is cylindrical with a diameter equal to that of the completed twist; the inclined passages are widened in the direction of the wire guide before reaching the central clearance by internal clearances which allow the end portions of the wire to lie in a transverse plane when they are applied against the transverse flat bottom; in addition, the central clearance is enlarged on the side of each passage in a direction opposite to the direction of rotation of the head by a lateral clearance whose bottom starts from the level of the transverse flat bottom and rises in the direction of the thread guide. so as to push back each free end of the wire to wind it in the opposite direction.

A description will now be given, without any limiting intention, of a preferred embodiment of the invention. Reference is made to the appended drawings in which: ^• *.

- Figure 1 is a sectional view along II of Figure 2 of a ^" twisting device according to the invention, - Figure 2 is a view in the axis of the tor¬ sadage head, along the arrow B in FIG. 1, the clamps not being shown,

FIGS. 3a and 3b are views showing the position of the wire after a rotation of the twisting member of about half a turn,

FIGS. 4a and 4b are similar views after a rotation of approximately three quarters of a turn,

- Figures 5a and 5b are similar views after a rotation of about one revolution, - Figures 6a to 6c show the twist completed respectively from the side, from below and from above,

FIG. 7 is a sectional view along VU-VU of FIG. 1 showing a jaw of a wire retaining clamp,

- Figure 8 is a detailed sectional view along VIII- -VIII of Figure 2 showing a raised surface.

For a better understanding of the constitution of the device of the invention, it is preferable to give it now a brief description followed by an explanation of its operating mode. This will make it easier to see the reason for certain construction details which are described completely below.

A device according to the invention comprises a single piece of revolution constituted by a twisting head 1, constructed symmetrically, having two inclined cylindrical passages 2 and 3, a central hollow recess 4, a conical outer part. 5, two clearances 6 and 7 internal to channels 2 and 3, and two openings 8 and 9 which have raised surfaces 10 and 11 as a background.

This twisting head is associated on one side with an external stop 12 situated opposite one of the cylindrical passages 2 and with a fixed shearing means 13 intended to cooperate with the end of the other passage 3.

_. WIPO The part 1 is held in place in a frame 14 by two bearings 15 and driven in rotation by known external means 16. Two independent and symmetrical clamps 17 and 18 also form part of the device, each being able to hold in position one of the parts ends of the wire. A detailed description will be given below.

A known yarn guide 19 ensures the continuity of a • guide circuit around the object to bind S, ^'while a known outboard engine body 20 serves to urge the binder yarn 21, which is sometimes represented, for clarity of the drawing, by a simple mixed line.

At the start, the front end of the tying wire is at the level of the shears and the object to be tied S is inside the wire guide 19; the twisting head 1 is stopped at a position which ensures the continuity of the guide of the thread through the passage 3, the thread guide 19 and the passage 2. The drive member 20 pushes the tying thread 21 in the passage 3, then in the clamp 17, in the thread guide 19, in the clamp 18 and in the passage 2. The thread stops against the stop 12.

The clamp 18 closes and retains the binding wire 21 while the motor member 20 reverses in rotation and tightens the object to be tied S by pulling on the binding wire 21. At the end of tightening the clamp 17 closes and retains the binding wire 21. The drive member 20 stops and the twisting head 1 begins to rotate. The tying wire is immediately cut between the fixed blade 13 and the outer edge 22 of the passage 3. The rotation of the head 1 continues and the two free end portions 23 and 24 of the tying wire begin to wind the one around the other, the necessary length being obtained by the axial sliding of these end portions of the wire 21 which enter the passages 2 and 3.

After part of the rotation, the rectilinear parts 23 and 24 pivot around the angles 25 and 26 of the channels 2 and 3, under the effect of the progression of the first part of the twist 27, the end parts 28 and 29 of the parts 23 and 24 staying in the openings

51 internals 6 and 7. At this time the twist 27 touches the bottom 30 of the central clearance 4 and the current twist has the configuration of FIG. 3. The progression of the rotation of the twist head 1 forces the thread to s '' spiraling around the first part of the twist 27 parallel to the bottom 30 of the clearance 4, the clearances 8 and 9 allowing the orientation of the ends 23 and 24 of the binding wire in the plane of the spiral part of the twist . The current twist then has the configuration of FIG. 4. A further progression of the rotation of the twisting head 1 causes the arrival of the end portions 28 and 29 of the binding wire on the raised surfaces 10 and 11; these end portions are then raised in the direction of the start of the twist 27. This results in an inversion of the direction of progression of the twist so that a second layer covers the first winding. The twisting in progress then takes the configuration of FIG. 5. The continuation of the rotation of the twisting head 1 causes the complete winding of the end portions 28 and 29 which come to end against the portions 31 and 32 of the binding wire 21 surrounding the object to be linked S.

The completed twist then has the configuration of Figures 6a, 6b, 6c. It has only a slight relief in relation to the circled object and it only has rounded surfaces terminated by an extreme flat face.

Such a twist combines excellent presentation with good solidity due to its two superimposed windings.

The device necessary for its execution comprises only the following three mobile elements: the twisting head 1 and the two clamps 17 and 18.

More easily understood now detailed description ^"of the three.

In the head 1, the passages 2 and 3 are inclined symmetrically so as to be substantially in the direction of the wire guide 19. Each passage 2, 3 has an external opening opening in the lateral face of the head 1.

In the normal stop position of the head 1, the external orifice of the passage 2 opposite the drive member 20 is very close to the fixed external abutment 12 while the external orifice of the passage 3 on the side of the motor member 20 is in the extension of a channel '33 drilled in a fixed part 19B of the wire guide 19 to constitute the shearing means 13. This channel 33 also serves to guide the wire 21 coming from the motor member 20 ^' feeding the wire 21. The latter is sheared, from the start of the rotation of the head 1, as a result of the displacement of the passage 3 relative to the channel 33. The passages 2 and 3 have a determined length so that the wire is sheared exactly to the length necessary to achieve the twist visible in Figure 6a. There is no extra length to cut later and the finished twist does not have to be folded.

Inside the head 1, the incli¬ born passages 2, 3 open into a hollow central clearance 4 whose bottom 30 is flat, that is to say located in a plane perpen¬ dicular to the axis of rotation of the head 1. Opposite its bottom 30, the central clearance 4 is open towards the interior of the wire guide 19, that is to say towards the object S to be tied. Before reaching the central clearance 4, the passages 2, 3 are widened, in the direction of the wire guide 19 and of the object S to be linked by the internal clearances 6, 7. These allow the wire to be completely placed in a transverse plane, as soon as it left the inclined parts which made it possible to initiate the twist. This situation is illustrated in Figure 3a. The transverse flat bottom 30 gives the wire the planar terminal end face of the twist, as can be seen in FIG. 4a. It is therefore clear that the depth of the central clearance 4 is equal to the length of the desired twist.

The central clearance 4 is enlarged on the side of each passage 2, 3, in a direction opposite to the direction of rotation of the head 1, by lateral clearances 8, 9.

In the radial direction, the latter have a length at least equal to that of the free end portions 23, 24 of the wire 21 after they have been laid flat transversely, as explained above and as seen in FIG. 4b. . FIG. 8 shows that each lateral clearance 8, 9 has a bottom which leaves from the level of the bottom 30 of the central clearance 4 and which then rises progressively in the direction of the thread guide 19 and of the object S to be tied. Each bottom 10, 11 is raised so as to push the free end 28, 29 of the wire in the opposite direction from the first winding. Each end part 28, 29 is pushed back as soon as the wire 21 is completely withdrawn, due to its winding, the internal clearances 6, 7 of the passages 2, 3. FIG. 4b shows the wire just when the lifting is going to take place. produce. Continued rotation causes, as has been said, a final winding in the opposite direction (FIGS. 5a, 5b) until the final configuration of FIGS. 6a to 6c.

With the exception of the lateral clearances 8, 9, the central clearance 4 is cylindrical, with a diameter which is equal to that of the completed twist measured on the second inverted winding (Figures 6b or 6c). Consequently, when the twist is finished, the head 1 could rotate indefi¬ nently, without risk of breaking or even of additional tension of the wire 21.

This result is obtained because the head 1 twists only the free end parts of the cut wire exactly to the desired length, while the tightening tension around the object S is maintained by the clamps 17, 18.

Figure 1 shows that each clamp 17, 18 comprises a body 34 which constitutes a fixed part 19A, 19B of the wire guide 19 in which a guide groove is hollowed out

(fig. 7). 35 / Near the head 1, on either side thereof, a movable jaw 36 is pivotally mounted about a radial axis 37. Each jaw is shaped to end in a spout 36 'locally constituting a wall of the groove 35 which is open towards the object to be strapped as is known. With this jaw 36 are associated a spring plunger 38 acting in the opening direction and a jack

40 with push rod 41 acting in the closing direction. On the fixed part of the wire guide 19, each jaw 36 is located as close as possible to the rotating head 1. In

SUBSTITUTE SHEET T (- ^OM g closed position of the jaws 36, the wire 21 is strongly tightened in the groove 35 and immobilized against any slipping, the fixed part of the wire guide serving as the second jaw of the pliers. . When the thread placed around the object S to be tied is clamped in the clamp 18, near the head 1, on the side of the channel 33, the tension of the thread 21 can be adjusted exactly, by means of a reverse movement. of the drive member 20. The closure of the second clamp 17 on the side of the stop 12 for the arrival of the wire 21 maintains the latter at the voltage which has been given to it. This tension is retained during the making of the twist, which only interests the free end portions of the wire, apart from the clamps 17, 18 since these act on the wire between the head 1 and the object S to be bound.

It will be noted that the movable jaw 36A (fig. 1) of the clamp 17 has a lateral surface which is arranged very close to the head 1 so that this surface serves as a stop 12 for stopping the wire 21. The existence and the the location of the clamps 17, 18 is an essential characteristic; thanks to it the twisting is done on the end parts J.ibers of the wire without variation of the tension of the latter. The twisting could be done in any desired manner by means of an appropriate corresponding interior configuration of the central clearance 4 into which the passages 2,3 open. The configuration described above is preferred because it gives a particularly advantageous twist. It is clear that, from the teaching provided by the invention, a person skilled in the art could easily adapt any other configuration of the interior clearance of the head, without however departing from the scope of the invention, with a view to '' get another type of twist.

O

Claims

CLAIMS.

1. Device for twisting the two end parts (23, 24) of a wire (21) serving as a link around an object (S), comprising a grooved wire guide (19) (35) with 5 a part fixed (19A, 19B) containing a rotary twisting head (1) having two opposite inclined passages (2, 3) starting from the lateral face of this head in extension of the groove (35) in a position for stopping said head (1), characterized in that two opposite clamps (17, 18)

10 are arranged to immobilize respectively the end portions of the wire (21) in the wire guide (19) near the head (1) and the latter has a hollow central clearance (4) open towards the interior of the wire guide (19), into which the opposite inclined passages open

15 (2, 3), this central clearance (4) having an interior configuration suitable for the twist to be produced.

2. Device according to claim 1 characterized in that a stop (12) is arranged opposite the external orifice of a passage (2) and a shearing means (13)

20 is arranged symmetrically in correspondence with the external orifice of the opposite passage (3).

3. Device according to claim 2 characterized in that the length of the passages (2, 3) is determined so that the wire (21) is sheared to the exact length

25 necessary for the preparation of the. twist.

4. Device according to claim 2 characterized in that the shearing means (13) consists of a fixed part (19A) of the wire guide (19) in which is drilled a channel (33) for guiding the wire (21) as an extension of

30 corresponding passage (3).

5. Device according to claim 1 characterized in that each clamp (17, 18) respectively comprises on the one hand the fixed part (19A, 19B) of the wire guide (19),

"On the other hand a movable jaw (36, 36A) suitable for imznobi-

35 read the wire (21) in the groove (35) ^' of the wire guide (19).

6. Device according to claim 5 characterized in that a movable jaw (36A) has a lateral surface

O PI close to the head (1) constituting the stop (12) for stopping the wire (21).

7. Device according to claim 1 characterized in that the hollow central clearance (4) is terminated by a transverse flat bottom (30) at a depth equal to the length of the desired twist and it is cylindrical with a diameter equal to that of the twist finished.

8. Device according to claim 7 characterized in that the inclined passages (2, 3) are widened in the direction of the wire guide (19) before reaching the central clearance (4) by internal clearances (6, 7) which allow the end portions (23, 24) of the wire (21) to lie in a transverse plane when they are applied against the transverse flat bottom (30).

9. Device according to claim 7 characterized in that the central clearance (4) is enlarged on the side of each passage (2, 3) in a direction opposite to the direction of rotation of the head (1) by a lateral clearance (8 , 9) whose bottom starts from the level of the transverse flat bottom (30) and rises in the direction of the wire guide (19) so as to repous¬ ser each free end part (23, 24) of the wire (21) to wind it in reverse.

WIPO