FR2495653A1 - IMPROVED MACHINE FOR THE PRODUCTION OF STRANDS - Google Patents

Abstract

THE OBJECT OF THE INVENTION IS A MACHINE FOR FORMING A STRAND, CHARACTERIZED BY THE FACT THAT IT INCLUDES A WIRE FEEDING GROUP 10, A ROTATING GROUP 11 RECEIVING THESE WIRES AND SUBJECTING THEM TO A TORSION TO FORM A STRAND AT DEFINITIVE PITCH AND SENDING THE STRAND THUS FORMED TO A GUIDE WITH ARC 33 ROTATING AT A SPEED EQUAL TO ABOUT HALF THE SPEED OF ROTATING GROUP 11, LEDIT TORON, AT THE END OF THE GUIDE COURSE, BEING RETURNED - BY A REFERENCE OF WHICH THE AXIS TURNS WITH THE GUIDE - TOWARDS A WINDING SPOOL 37, EXCEEDED BY LEDIT GUIDE, A STATIONARY AXIS.

Description

We know that we commonly use bi-

  twist for the production of strands of steel wire and, more generally, of wire of non-ferrous materials

and not metallic.

  Bi-twist machines are powered from

  crowns or rollers that run on supports

  ports supported or anchored on the ground. The wires are intro-

  duits in the bi-twist machine where they are stranded with a step equal to half of that which would correspond

  the number of turns made by the bi-torsion machine.

  Indeed, the strand is subjected to a first twist when it enters the machine and to a second twist when it

  is collected by fixed organs.

  The strands thus produced are collected on coils which rotate around their stationary axis at

  inside the bi-torsion machine.

  The stranding steps are imposed on the strand by acting on the speed of advancement of this strand when it has already undergone the first and second twist, characteristics

of the machine.

  This working method requires that the crowns or

  feed rollers have geometrical lengths of wire

  three times corresponding to the formation of a strand with a double pitch of the effective pitch, which results on the contrary from

the duplication of the twist.

  The purpose of the present invention is to provide a

  machine in which the strand does not undergo dislocation

  harmful, specific to known machines, but assumes the exact geometrical configuration provided by the ratio between advancement of the wires and speed of rotation of the

machine for twisting.

  To achieve this result, a ma-

  china which includes a wire feed group, a rotary group which receives the wires and subjects them to a twist to form a strand with definite pitch and sends this strand thus formed to an arc guide, rotating at a speed equal to approximately half the speed of the rotary group, the said strand, at the end of the guide path, being returned backwards - by means of a return pulley rotating with the guide - to a winding reel, at

  stationary axis., which is exceeded by said guide.

  The aims of the invention, as well as the characteristics

  ques essentials of machine structure according to the

  vention, will be better identified thanks to the description

  given below, by way of example, of a form of realization

  sation, illustrated by the accompanying drawing, in which the single figure is a schematic view of the machine according to the invention. As this figure shows, the machine shown

  consists of three online units, namely: a rectifier

  sonsese (10), a rotary block (11) and a tor-

deuse final winder (12).

  The groups (10) and (11) are mounted on supports (14) so as to be able to turn together, driven in rotation by the transmission (16) mounted on the shaft

(17) powered by the motor (18).

  Both the group (10) and the group (11) are of a traditional type, the first carrying out the straightening of the wires which come from a supply device.

(19) schematically represented.

  The device (11), also of a known type, comprises

  takes a muffle (20-21) on which the strand in formation is guided. The pulleys (20-21) are set in motion

  by a toothed wheel (13) actuated by a gear train

  ges (15) so as to advance the strand in formation

  at a preset speed which, in combination with the speed-

  of rotation of the group, imposes on the strand a defined pitch.

  The rotary muffle is completed by traditional devices which guarantee a correct arrangement of the

  wires that combine to form the strand.

  The group (12) comprises two end rotary hubs (30), connected by the transmissions (31) to the shaft (17) and supported at (32); between the two hubs (30) is mounted an arcuate guide (33) on which are provided loops (34) for guiding the strand. The course of this strand continues towards the pulley (35) which returns it towards

  a drive unit (36) placed before a supply coil

bearing (37).

  The drive unit (36) and the coil (37) are mounted in a cradle (38), freely supported by the hubs (30), so that it remains stationary when the latter rotate. It should be noted that the kinematic transmission ratios between the engine (18) and the groups (10-11) and (12) are such that the first rotate at a speed substantially double that of the second. In the practical embodiment described, the transmission (16) has a transmission ratio twice that of the

transmission (31).

  The operation of the machine is therefore as follows.

  From the device (19) arrive at the stranding machine

  wires in the direction followed by a dotted line

  tillés representing the course of the threads which form the strand; the wires are straightened in (10) and stranded in (11), pulled by the group's mittens. The wires leave this group formed in strand with a pitch and a configuration

definitive geometric.

  The strand then passes over the guide (33); in this group, the strand theoretically undergoes a first twist

  at the inlet and a second between the pulley (35) and the coil

ne fixed axis (37).

  Given that the guide (33) rotates at a speed equal to half the speed of the group (11), one could assume that the strand risks losing half of its twist; however, this does not happen in the machine according to the invention, because the strand adopts on the guide the line

  which corresponds to it by centrifugal action at the

  which it is subjected, without forced support on the passers-by (34) or on the guide, so that it can turn on itself while maintaining the step which it. was imposed by the group (11) or by increasing it very slightly, and of all

  ways never to the point of warping.

  At the exit of the pulley (35), the strand is subjected to another twist, because it is routed towards the stationary group (36), and the strand is thus exactly tightened to the twist with which it came out of the group (11), although the speed of group (12) is equal to the

  half that of the groups (10-11).

  It is obvious that the small differences that can occur in this group speed ratio have not

  a lot of importance; indeed, if the speed of the tor-

  the two winder (12) is slightly higher or lower

  less than half the speed of the previous group, the strand will simply undergo a little additional torsional or unwinding effort, without this being able to modify

its geometric configuration.

  With the machine according to the invention, the final pitch stranding being obtained in a single group and a single phase, with adequate control of the position of the wires, it is possible to produce a strand of an exceptionally exact geometrical configuration, without no anomalies

training.

  It is obvious that if the wires were directly routed to the torsion group (12), they would undergo a first mid-twist at the entry and, under these conditions, they would be returned by the pulley (25) to undergo the

  second mid-twist. However, in practice

  that on a strand which is only half-plied, deformations easily occur which are not canceled during the final twisting which follows, and the product is therefore

not satisfying.

  In the light of the provisions of the invention, as defined above, it becomes obvious that many variants can be made to the machine

  described above as a simple example.

  The configuration of the different groups is not immutable, each group performing a processing of the wires according to a technique already known; thus, the wire straightener (10), advantageous but not essential, can be

both fixed and rotary.

  The rotary group (11) which forms the strand can have any configuration according to known techniques; since it is only asked to apply to the wires a twist which forms a strand of a pitch and a shape

  to feed the mower (12).

  The winding twister (12) can also be

  equipped with all accessory and complementary devices

  silences known to properly collect the strand; it is particularly important that the method of guiding the latter from entry to return for the second twist is designed so as not to impart a rotation to the strand which can unroll it substantially, but that it allows

  on the contrary, to leave this strand free to rotate on itself-

  even with respect to the guide (33) in order to maintain the tor-

  sion that the previous torsion group (11) gave it.

  The machine object of the invention is designed to form strands of wire, metallic or not, either bare or

  provided with a coating, for example of plastic.

Claims (4)

Claims   1 - Machine for forming a strand, characterized in that it comprises a group (10) for supplying wires, a rotary group (11) receiving these wires and subjecting them to a twist to form a strand with the final pitch and sending the strand thus formed to an arc guide (33) rotating at a speed equal to approximately half the speed of the rotary group (11), the said strand, at the end of the guide path, being returned backwards - by a return whose axis rotates with the guide - to a coil   reel (37), passed by said guide, with stationary axis   nary. 2 - Machine according to claim 1, characterized in that said rotary group (11) comprises means for advancing the son at a speed of movement in a preset relationship with the speed of rotation of the   group, in order to define the pitch of the twist.   3 - Machine according to claim 1, characterized in that said rotary group (11) forming the strand is   associated a group (1o) for the straightening of the purchased wires mined to form the strand.   4 - Machine according to claim 1, characterized by   the fact that the strand is held on said tour guide   free to turn on itself.