Description

The present finding concerns a pincer for binding with wire-shaped bodies, according to the general part of claim 1.

Many industrial activities use the operation of binding with wire-shaped bodies that are twisted together to form a slot that holds the product.

As an example we quote the binding of reinforcement rods in construction casts.

It is known that rods intended to form the reinforcements of reinforced concrete casts in construction must be bound together so as to be able to maintain the position taken up before carrying out the casting of concrete.

These binding operations require substantial use of labour, as is well known to all workers in the field, which, after many hours work, results in heavy fatigue.

Indeed, the operator, at each binding point, when he has picked up the pincer, must make the tool perform two operations, to be precise a rotation operation about its own longitudinal axis to carry out the twisting of the wire-shaped body and a cutting or shearing operation to detach the portion of the twisted wire-shaped body or binding from the remaining part of feed wire-shaped body usually wound in a skein.

Even those who are not experts in construction can easily imagine the substantial difficulties encountered by an operator, who has to repeat over and again the operation of picking up/closing the branches and the subsequent rotation of the tool before the final shearing of wire-shaped body.

Indeed, by holding the pincers manually, each time they are held it is possible to rotate the tool by a maximum of 180°, for which reason it carries out just a half turn of wound wire portion.

It thus follows from this that the operator, in order to make a strong binding, must repeat many times over the opening/closing of the branches and the rotation of the tool, all requiring a waste of energy and a substantial period of time even by qualified personnel.

In patent documents IT01280278, IT01281621, EP 0727549 and US 5,669,425 a pincer is described that makes the binding operation easier, making it easier for the operator to carry out the rotation action of the pincer, after this has been hooked to the wire-shaped body, hereafter identified with the generic term "wire".

Such a pincer foresees that one of the two branches is screw-shaped with a long pitch, on which a sleeve is mounted, equipped with balls held by a grooved flange, so that, when the pincer is closed, i.e. the branches are locked on the wire, by making the aforementioned sleeve slide axially on the aforementioned screw, the pincer is forced to rotate, so as to carry out the binding of the wire itself, without having to physically rotate the hand, with substantial saving of physical effort for the operator. Operatively, the use of the aforementioned rotary pincer foresees the following steps:

a) manual closing of the two branches so that the jaws of the two heads are locked on the portion of the wire to be twisted;

b) locking of the two arms of the pincer in the aforementioned closing position, so that the pincer itself can remain freely fixed to the wire to be twisted;

c) pushing back the ball sleeve, which causes the rotation of the handle on which it is fitted, as well as of the two jaws, which involves the formation of some twists on the wire constituting the final binding.

d) cutting the wire, compressing the two arms of the two branches, to separate the binding twists from the rest of the feed wire.

The adoption of such a rotary pincer thus allows the binding wires, such as those present in metal reinforcement for the casting of reinforced concrete, to be twisted and cut, without having to rotate the tool by hand, but simply by applying a traction with longitudinal displacement of a sleeve applied on one of the two handles of the pincer itself.

Against the aforementioned substantial advantages, the use of the pincer described above has an operative drawbacks that, in particular working conditions, becomes very negative.

Indeed, as can be seen from the succession of working steps outlined above, the shearing with which the detachment of the binding from the feed wire is carried out takes place after the pincer, with the jaws closed, has been rotated for a few turns.

This means that, during the rotation of the pincer, since the wire has not yet been cut, the stock of wire is also rotated at the same time, normally consisting of a wound reel or a container that contains the skein, left free to dangle or applied onto the free lever arm of the pincer itself.

With such an embodiment, the supports, reel or container, are also made to rotate for which reason, due to their bulk, they make the rotation of the pincer fairly problematic, in particular in narrow or inaccessible locations.

Of course, such a drawback has an even greater negative impact when a normal pincer is used, i.e. when binding is carried out with manual rotation of the tool.

The purpose of the present finding is that of making a rotary pincer both of the conventional type and made up of two identical branches or of the type described in the aforementioned patent documents, which lacks the listed operative drawback, so as to make the entire binding operation quicker and the pincer more manageable.

Such a purpose is achieved, operatively, by foreseeing that the shearing step, to detach the wire portion, necessary to carry out the binding, from the rest of the feed wire, be carried out before the rotation step of the pincer. In such a way the reel or the container of the wire is moved away from the pincer for which reason said pincer, freed from the bulk of said elements, is less bulky and therefore can rotate freely and with greater ease.

Of course, the pincer, after the shearing of the wire, must remain attached to the portion of wire to be twisted for the entire duration of its rotation.

This is made possible thanks to the special configuration of the two jaws or heads of the pincer for which reason, with the closing thereof, the shearing of the wire takes place and, before this step has ended, the locking of the jaws themselves on the portion of wire to be twisted begins, leaving the wire underneath free to fall, together with the possible skein or container attached to it.

The finding shall hereafter be described in greater detail, with the help of the attached tables of drawings, where:

- fig. 1 (table I) represents the pincer according to the finding, in open position;

- fig. 2 represents a detailed view of the jaws, sectioned according to the line II-II of fig. 1;

- fig. 3 (table II) represents the pincer according to the finding in operative condition;

- figs. 4 to 7 (table III) represent the operative steps, in succession, of the pincer according to the finding;

- fig. 8 (table IV) represents a pincer with the normal branches, equipped with the shaped jaws according to the finding.

As can be seen from the figures, the rotary pincer according to the finding, wholly indicated with reference numeral 1, comprises an arm 2, on which a sleeve 3 is fitted, equipped with balls, which slides on a long pitch screw 4 and arranged inside the aforementioned sleeve for which reason, with the longitudinal traction of said sleeve (see arrow "Z") , the rotation (see arrow "V3") of the pincer takes place, after the binding wire 5, which unwinds from the container 6, has been gripped, with the closing of the jaws 7 and 8, by the pincer itself.

The pincer is equipped with a plate 9, which is used to hold the other arm 10 when the pincer is in closed position.

All of this is per se known, as described in the aforementioned patent documents.

The novelty characteristic of the finding concerns the configuration of the end of the two jaws 7 and 8 which, through mortising, during their closing, carry out a shearing action of the wire and, at the same time, a pressing action on the portion of wire to be twisted to allow the pincer itself to remain connected to the aforementioned wire.

A further characteristic of the finding consists of the fact that the rotation of the pincer for the twisting of the wire is carried out after the cutting/pressing action described above.

Operatively, therefore, the use of the rotary pincer according to the finding foresees the following steps:

a) manual closing of the two jaws of the pincer on the portion of the wire to be twisted to carry out the shearing of the wire and the compression, between the jaws themselves, of the portion of the wire to be twisted;

b) locking of the two arms of the pincer in the aforementioned closing position, so that the pincer itself remains fixed to the portion of the wire to be twisted;

c) pushing back the ball sleeve, which causes the rotation of the handle on which it is fitted, as well as of the two jaws, which involves the formation of some twists on the wire, constituting the final binding.

Constructively, as can be seen from the comparison between figs. 1 and 3, the two jaws 7 and 8 have the respective interfacing walls shaped like a tenon and mortise, where, when they close, the two projections 7.1 and 7.2 of the first jaw 7 engage with the projection 8.1 of the second jaw 8.

In greater detail, as can be seen in figures 4 to 7, after the binding wire 5 has been introduced between the open jaws 7 and 8 (see fig. 4), said jaws are closed.

Thanks to the shaped profiles described above, in the first closing step (arrows "Vl") of the jaws 7 and 8 (see fig. 5) , a shearing action of the wire 5 is carried out between the projection 7.1, which acts as a cutting blade, and the opposite projection 8.1, which acts as a counter blade.

With this the portion of the wire 5.1 to be twisted is separated from the rest of the wire 5, which is taken away from the pincer.

Before the cutting action described above has ended, continuing the closing of the jaws (arrows "V2") , the pressing action of the wire 5.1 begins, carried out by the projection 7.1, until they are completely closed.

As can be seen in fig. 6, to increase the gripping effect, a bending action of the portion of wire 5.1 between the two jaws 7 and 8 is combined with the pressing, through the combined action of the two projections 7.2 and 8.1, which act as punches.

Finally, after having locked the arm 10 through the plate 9, the pincer is rotated (arrow V3) in the way described above, obtaining the twisting 5.2 of the wire and therefore the desired binding of the products λΛK".

The finding also foresees two further embodiments, which improve the use of the rotary pincer.

As can be seen in fig. 2, the jaw 7 is mounted eccentrically on the pin 11, through the bushing 12 so that, by angularly rotating the aforementioned bushing, the position of the blade 7.1 is modified, thus being able to recover the possible wear of its cutting edge with respect to the counter blade.

Moreover, as can be seen in fig. 2, the jaws 7 and 8 project slightly at the side, to allow the operator to insert the binding wire 5 more easily between the jaws themselves. As can be seen in fig. 8, the constructive characteristics according to the finding are also applicable to a common pincer 100, provided that it has the jaws or heads 7 and 8 of the branches 101 shaped according to the profile according to the finding.

The advantages obtained by adopting the rotary pincer according to the finding are clear, in particular in that the cutting of the wire, taking place before the rotation of the pincer itself, makes it possible to carry out the binding also using different wires to metal wire that are weaker than the aforementioned wire, such as plastified wire or vegetable wire, used in the field of agriculture for binding grapes, since the weight of the reel or of the container for the wire does not act on the wire itself.

The pincer described above, the completely manual one or the partially automated one, can nevertheless also be used according to the conventional method, when one wishes to just vary the final position of the binding of the wire 5.

It is clear that the particular shape taken up by the pincer in the attached drawings can be modified, based upon particular requirements of the user, with the essential characteristics according to the finding still remaining the same, without for this reason departing from the scope of the following claims.