ITMC20110021A1 - ISOTONIC TRAINING MACHINE EQUIPPED WITH A BENCH WITH ARTICULATED HEADREST. - Google Patents

Description

DESCRIPTION

accompanying a patent application for an industrial invention entitled:

â € œISOTONIC TRAINING MACHINE EQUIPPED WITH A BENCH WITH ARTICULATED HEADRESTâ €.

TEXT OF THE DESCRIPTION

The present patent application for industrial invention relates to an isotonic training machine equipped with a bench with an articulated headrest.

The peculiarities and advantages of the present invention will become more evident following a brief description of the prior art.

As is known, an ever-increasing number of people usually attend gyms to develop or maintain their physical shape, using the special machines provided to them.

Among the most used machines are certainly the isotonic training machines, those that favor the development or maintenance of the user's muscle mass by lifting or pulling weights.

A specific type of these machines are those that adopt a bench consisting of a seat and a backrest with variable inclination.

In this context, the user is intended to sit on the aforementioned seat and lean his back on the aforementioned backrest before gripping a barbell loaded with the desired amount of weights and lifting it, by force of his arms. , even for repeated series.

It is easy to understand, however, how the different possible inclinations attributed to the aforementioned backrest must lead to the user being forced, from time to time, to assume different postures on the aforementioned bench, which naturally correspond to a different level of effort and a specific solicitation towards the various muscular districts of the user himself.

Normally these benches can vary their position for a range of inclination comprised between a condition in which the respective backrest assumes a perfectly vertical position and a condition in which the same backrest assumes a sensibly sub-vertical position.

In the first case, the user is forced to practice substantially seated, while in the second case the user is forced to practice substantially lying down; it being naturally foreseen that for any possible intermediate angle of inclination of the aforementioned backrest the user is then forced to assume gradually different postures.

It should also be said that each of the aforementioned variable inclination benches is often found to cooperate with a pair of upright rods which adopt on the front respective series of â € œshelfâ € hooks, designed to be used to support in horizontal position, and on different heights , the barbell which must then be lifted by the person who has taken his place on the same bench.

In particular, a similar pair of rods is located on the back of the aforementioned bench, in a position that allows the user occupying the bench to extract the aforementioned balance wheel from the respective pair of hooks that supports it, perform the desired repetitions and then reposition it in the same position from which it was taken.

The selection of the `` rest '' position of the balance wheel on a similar pair of upright rods naturally depends not only on the height of the user, but also on the more or less inclined position that the latter will want to give to the respective user. bench press before starting your exercises.

A careful examination of this traditional technology has made it possible to highlight a significant practical drawback, which in reality greatly penalizes the practicality and ease of use of the current machines equipped with variable inclination benches.

To optimize the effort of the user when positioned a bench with variable inclination, it is in fact envisaged that in certain conditions the bench itself must be equipped with a headrest and that in other conditions it must be without one.

In particular, when the backrest of such a bench reaches the point of maximum inclination (at which the respective user assumes a substantially lying position), it is essential that the user himself can firmly abut the head against a perfectly aligned padded headrest. with the same backrest.

A similar support point for the head, in fact, allows the user to optimize the effort made to lift the barbell while lying down, in the sense of being able to practically involve the entire musculature of the upper part of the body.

When, on the other hand, the back of the same bench is led towards the vertical position, the presence of the aforementioned headrest is not only useless, but also inconvenient, as it can easily be an obstacle to the user's freedom of movement.

For these reasons, the current machines equipped with a bench with variable inclination provide that the respective bench is equipped with a removable headrest, which is able to be kept at the top of the respective backrest as long as it has assumed the position of maximum inclination and on the other hand, it must be removed when the backrest must be gradually brought back to its vertical position.

It goes without saying that until now a similar assembly-disassembly operation of the headrest must be performed directly by the user of a traditional variable inclination bench, imposing on him a certainly unwelcome manual operation and perhaps even an interruption any regular cadence programmed for the execution of his exercises on the different inclination angles of the bench itself.

Starting from similar critical considerations, the specific purpose of the present invention is to produce a machine of the type equipped with a variable inclination bench, within which, however, the bench itself is associated with an innovative articulated headrest. .

The articulation of this headrest is such that it is automatically able to vary its position with respect to the backrest of the new bench in question, as a result of the different inclination angles imposed on the backrest itself.

It is meant otherwise that such an articulation means that the aforementioned headrest can assume a position perfectly aligned with the underlying backrest when the latter assumes the sub-vertical position of maximum inclination and can instead rotate progressively downwards and towards the rear of the backrest itself, as the latter tends to return to its perfectly vertical position.

Another object of the present invention is to make possible the inclination variations of the bench supplied with the machine according to the invention according to extremely easy and fast methods.

A further object of the present invention is to make available to the user occupying the bench of the machine according to the invention a second pair of upright rods capable of supporting the balance wheel with which the same user will subsequently have to exercise.

In fact, the new machine in question is expected to be equipped, in addition to the traditional pair of rods located on the back of the respective bench, also with a pair of similar rods located just on the front of the bench itself.

This provision considerably increases the practicality of use of the machine in question; in fact, the respective user can freely decide, from time to time, to deposit his own balance wheel on the pair of rear rods or on the pair of front rods according to the specific exercise he intends to perform.

In this specific perspective, it should be noted that the ultimate aim of the present invention is to allow the user of the machine according to the invention to vary at will, with equally simple and fast methods, the position of the entire aforementioned bench with respect to to the two pairs of those aforementioned uprights intended to support the balance wheel on the front and rear of the same.

In this way the user can comfortably arrange, according to the needs dictated by his height and the length of his arms, to bring his bench from time to time to a position closer or further away than one or the other. ™ another of the aforementioned pairs of uprights; all this in order to have the certainty of being able to grip the barbell resting on them correctly and with less effort, once it has taken its place on the bench itself.

For greater explanatory clarity, the description of the invention continues with reference to the attached drawing tables, having only illustrative and certainly not limiting value, in which:

- figure 1 is an axonometric representation of the new machine in question, shown in the condition in which the respective bench maintains its backrest in vertical position;

- figure 2 is a side view of the aforesaid machine, shown after removing one of the sides of its supporting frame and in the specific condition in which the respective bench maintains its backrest in a perfectly vertical position; - figure 3 is similar to the previous one, but serves to show the aforementioned bench in the condition in which it maintains its backrest in partial inclination position;

- figure 4 is similar to the previous one, but serves to show the aforementioned bench in the condition in which it maintains its backrest in the position of maximum inclination;

- figure 5 is an axonometric representation of the aforementioned bench only, in the condition in which the respective backrest maintains a vertical position;

- figure 6 is similar to figure 5, but shows the aforesaid bench in the condition in which the respective backrest maintains a position of partial inclination;

- figure 7 is similar to figure 5, but shows the aforementioned bench in the condition in which the respective backrest maintains a position of maximum inclination.

With reference to the aforementioned figures, the machine in question (M) makes use of a metal support frame formed by two identical ground stabilization legs (1a, 1b), substantially in an arc of circumference, each of which bears at the two respective ends rubber feet (2).

These two arched legs (1a, 1b) are connected on the back, side by side, by means of a crossbar (3), also used to support a platform (4).

Above each of these legs (1a, 1b) a rear rod (5) and a front rod (6) are vertically fixed, made integral, towards the base, by a connecting crosspiece (7).

Figure 1 also allows us to verify how the aforementioned front (5) and rear (6) rods of the first (1a) of the two aforementioned arched legs occupy an exactly symmetrical position with respect to that occupied by the corresponding front (5) and rear (6) rods. ) of the second (1b) of these legs.

On the inside of the two pairs of rear rods (5) and front rods (6), respective hooks (5a, 6a) are welded in cantilever mode, facing each other and with the concavities facing upwards; it being usually provided that each side-by-side pair of such hooks (5a, 6a) has the function of horizontally supporting a typical weight lifting barbell (B), as long as it is not gripped by the user of the machine according to the invention (M).

Below each of the aforementioned legs (1a, 1b), on the other hand, a respective cylindrical bar (9) is hung by means of two end brackets (9a), which practically occupies the space between the aforementioned rear rod (5) and the aforementioned front rod (6).

Well, such a load-bearing frame is intended to support a bench (10) making use of a sturdy metal profile (11), substantially at â € œJâ €, clearly visible in figure 6. In this context it is envisaged, in particular, that the straight section (11a), facing upwards, of the aforementioned â € œJâ € profile (11) must frontally support the backrest (SC) of the aforementioned bench (10), while the relative lower section (11b ), substantially disposed at 90 °, has the task of supporting a quill (12) on the front, parallel to that of the aforementioned straight section (11a) of the same â € œJâ € profile (11).

The stem (13) which supports the seat (SE) of the aforementioned bench (10) is inserted inside this tube (12) with the possibility of axial sliding.

It goes without saying that the presence of a similar sliding stem (13) was designed to allow each user to adjust the height of the overlying seat (SE) according to their height; the examination of figure 2 allows to detect the presence of the aforesaid stem (13), as well as of the cross pin (SP) which allows to fix the aforesaid seat (SE) on the desired height, using two corresponding series of holes with horizontal axis, specially made on the outer tube (12) and on the inner stem (13).

On the front of the aforementioned â € œJâ € profile (11), substantially at the height of the connection point between its two aforementioned sections (11a, 11b), a first horizontal axis bushing is transversely welded (14) .

A second similar bush (15), parallel to the first (14), is instead welded on the back and towards the top of the aforementioned straight section (11a) of the same â € œJâ € profile (11).

The entire bench (10) is supported, with the possibility of varying its inclination with respect to the ground, by a respective metal supporting structure (ST), within which it is possible to identify a horizontal element, acting as an authentic support base, and a vertical element, as shown in figure 7.

More precisely, the horizontal element of the aforementioned supporting metal structure (ST) is formed by a rear side member (17) and by an identical front side member (18), placed side by side and connected at the ends by two identical sleeves cylindrical (19), as expressly shown in the aforementioned figure 6.

Moreover, it should be considered that the two aforementioned longitudinal members (17, 18) adopt a length substantially equal to the distance between the two aforementioned legs (1a, 1b) of the machine in question (M), so that their aforementioned connection (19) can be coupled, with the possibility of alternative sliding, on the outside of the aforementioned rods (9) fixed below the same arched legs (1a, 1b); to verify this condition, please refer in particular to the consultation of figure 1.

For its part, the aforementioned figure 6 allows to verify how from the center of the aforementioned rear side member (17) a sturdy arm (20) projects upwards, connected to the base with the front side member (18) by means of a plate arranged for cutting (21); it is useless that said arm (20) represents the vertical element of the aforementioned supporting structure (ST) of the bench (10).

In any case, it must be said that the aforementioned plate (21) is crossed by a third bush (22), exactly corresponding in size and orientation to the aforementioned first (14) and second bush (15) incorporated in the structure of the aforementioned bench (10).

A fourth bushing (23) completely corresponding to the aforementioned three (14, 15, 22) is fixed to the top of the aforementioned vertical arm (20).

Each of these four bushings (14, 15, 22, 23) contains a respective revolving pin (14a, 15a, 22a, 23a), which protrudes slightly from both ends.

The ends of the pin (14a) inserted inside the first bushing (14) and the ends of the pin (22a) inserted inside the third bushing (22) are connected by a pair of first levers (24a, 24b) .

The ends of the pin (15a) inserted inside the second bushing (15) and the ends of the pin (23a) inserted in the fourth bushing (23) are instead connected by a pair of second levers (25a, 25b).

With particular reference to figure 3, it should be noted, however, that the ends of the aforementioned pin (15a) of the second bushing (15) are inserted at the front ends of the aforementioned second levers (25), while the ends of the aforementioned pin (23a) of the fourth bushing (23) are inserted into the aforementioned second levers (25), substantially at half the length of the latter.

The two rear ends of these second levers (25a, 25b) are instead designed to support a padded cushion (P), which acts as a headrest for the aforementioned bench (10).

The combined examination of figures 5, 6 and 7 also allows us to verify how the first (25a) of the aforementioned second levers carries a first curved ear (26a) at the rear, located in an intermediate position at the pivot points of the two aforementioned pins (15a , 23a) and a second curved ear (26b) displaced in a more external position with respect to the pin (23a), but symmetrically opposed to it.

On each of these ears (26a, 26b) there is a similar through hole (26aâ € ™, 26bâ € ™).

The same figures instead show how the second (25b) of the aforementioned second levers carries an appendage (27) at the rear, in a position between the aforementioned third pin (15) and the aforementioned fourth pin (23). arranged cutting.

In correspondence with the tapered end of this appendix (27) the jacket of a compensation jack (28) is pivoted, whose extendable stem is instead fixed in correspondence with a peg (29) which projects horizontally on the side of the Aforesaid arm (20), near the bottom of the latter.

From the opposite side of the same arm (20), and at a considerably greater height, protrudes a substantially â € œLâ € (30) shelf which supports horizontally, on the outside of its vertical wing (30a), a first rigid cylindrical casing (31) which represents the housing seat of an axially sliding pin (32) and of the respective spring able to discharge a forward thrust on it, such as to allow said pin (32) to protrude permanently on the inside of the € ™ aforementioned vertical wing (30a) of the shelf (30), through a corresponding through hole made on it.

A second rigid cylindrical casing (33), similar to the first (31), is fixed horizontally on the inside of a cut welded eyelet (34) near one of the lateral ends of the aforementioned front side member (18).

Also in this case the aforementioned cylindrical casing (33) houses inside it an axially sliding pin (35) together with the respective spring which permanently tends to push it forward, in a condition that allows it to protrude on the outside. of the aforementioned eyelet (34), through the central hole of the latter.

From the center of the internal face of the first (1a) of the two aforementioned legs of the machine in question (M) a box-shaped plate (36) protrudes longitudinally, on whose front wall there is a horizontal series of circular through holes (36a).

Once the overall structure of the machine according to the invention (M) has been illustrated, all that remains is to clarify the methods envisaged for adjusting the attitude of its aforesaid bench (10) and of the respective headrest (P).

The combined examination of figures 1, 2 and 5 allows to verify the interaction modalities of the components of the aforementioned machine (M) as long as the respective bench (10) is maintained with its backrest in vertical position, that is to say in correspondence of its upper end stop.

In this situation, the aforementioned â € œJâ € profile (11) of the bench itself (10) is at a close distance with the aforementioned vertical arm (20) supported by the aforementioned pair of side members (17, 18) .

For their part, the two aforementioned first levers (24a, 24b), interposed between the pin (22a) of the third bushing (22) and the pin (14a) of the first bushing (14) maintain a substantially vertical position.

In this circumstance, a substantially vertical arrangement is also maintained by the aforementioned second levers (25a, 25b), i.e. those which are interposed between the pin (15a) of the second bushing (15) and the pin (23a) of the fourth bushing. (23).

In particular, the position assumed by the two aforementioned second levers means that the headrest (P) fixed at their free end faces the ground, completely hidden behind the backrest (SC) of the bench (10).

It is therefore easy to understand how the user who has taken his place on the same bench (10), in order to lift the barbell (B) from a substantially â € œseatedâ € position, is in a position not to suffer any uncomfortable interference, at the € ™ height of the head, from the headrest itself (P).

The further significant condition that occurs on this occasion is related to the fact that the second ear (26b) of the first (25a) of the second levers is arranged on the inside of the vertical wing (30a) of the aforementioned shelf (30) provided laterally to the aforementioned vertical arm (20), in a condition whereby its aforementioned through hole (26bâ € ™) can be penetrated by the aforementioned first pin with horizontal axis (31) which protrudes on the € ™ inside of the same tab (30a) of the shelf (30).

Such interference prevents any possibility of rotation of the two aforementioned second levers (25a, 25b), as well as, consequently, also of the two aforementioned first levers (24a, 24b) and therefore serves to stabilize the aforementioned â € œverticalâ € position. € of the bench (10).

It goes without saying that the machine in question (M) makes use of the possibility of unlocking such a set-up, whenever its user wants to use the aforementioned bench (10) in a â € œ lying downâ € setting.

A similar release can be carried out by the same user using a first knob (37) with respective control lever (37a) fixed laterally to the aforementioned â € œJâ € profile (11) which supports the bench (10) on the same side in correspondence of which lies, on the aforesaid vertical arm (17), the aforesaid shelf at â € œLâ € (30).

The operation of said lever (37a), substantially comparable in the operating logic to a brake of a bicycle, serves to put in traction a cable, not shown in the attached figures, able to retract inside the respective rigid casing (32) the aforementioned first pin (31), overcoming the resistance of the aforementioned spring enslaved to the same first pin (31).

In this way this pin (31) slips out of the aforementioned hole (26bâ € ™) of the second ear (26b) of the first (25a) of the aforementioned second levers, in such a way that these same two second levers (25a, 25b ), as well as, moreover, the aforementioned first levers (24a, 24b) acquire the freedom to rotate with respect to the aforementioned vertical arm (20).

At this point the user must impose a forward roto-translation on the entire bench (10), which also produces the loading of the aforementioned compensating jack (28), pivoted between the second (25b) of the second levers and the ™ aforesaid vertical arm (20).

In particular, the geometry of the aforementioned first (24a, 24b) and second levers (25a, 25b) means that the entire bench (10), following the aforementioned forward roto-translation, tends to perform a high-low stroke, at the end of which its backrest (SC) assumes its maximum inclination with respect to the aforementioned vertical arm (20) and its aforementioned seat (SE) reaches its maximum distance from the latter.

Figures 3 and 6 show the results of the first phase (substantially the first half) of the aforementioned forward roto-translation of the bench (10).

Meanwhile, note that the first two levers (24a, 24b) have made a forward stroke of about 45 ° and how the two second levers (25a, 25b) have instead made a forward rotation of about 90 °, until they assume a substantially horizontal arrangement, in correspondence with which the headrest (P) supported by them is still completely hidden on the back of the backrest (SC) of the bench (10).

Figures 4 and 7 instead show the position assumed by the bench itself (10) at the end of its aforementioned forward roto-translation, when it reaches its condition of maximum inclination and therefore the aforementioned desired â € œ lying downâ € position; in this context it can be stated otherwise that the bench itself (10) has reached its lower end point.

Well in this phase the two aforementioned first levers (24a, 24b) have reached the greatest angle of inclination forward and the two aforementioned second levers (25a, 25b) have completed their rotation of about 180 °, reaching a substantially coplanar attitude with the aforementioned straight section (11a), facing upwards, of the â € œJâ € profile (11) which supports the bench (10).

This implies that the headrest (P) supported by them is placed at the top of the backrest (SC) of the bench (10), in a condition in which the user lying on the same bench (10) can comfortably rest his head on it during lifting the barbell (B).

In the same situation it is envisaged that the aforementioned first ear (26a) supplied with the first (25a) of the second levers is arranged inside the aforementioned vertical wing (30a) of the shelf (30) which supports the first plug (31).

Certainly, to obtain such a condition, the user must operate again the aforementioned lever (37a) which controls the retraction of the first plug (31), to prevent the latter from opposing the entry of the aforementioned first orecchiola (26a) within the same shelf (30).

However, as soon as the same user has ascertained that such an insertion has actually occurred, he only has to interrupt the traction on the aforementioned lever (37a), so as to ensure that the aforementioned first pin (31) returns subject to the forward thrust of the respective spring and can penetrate exactly into the hole (26aâ € ™) supplied with the same first ear (26a).

This coupling naturally serves to prevent the two second levers (25a, 25b), the two first levers (24a, 24b) and ultimately the entire bench (10) from freely performing a new unwanted roto-translation in the opposite direction.

However, when you want to bring the bench (10) back to the substantially vertical position shown in figure 1, it will be enough to repeat the aforementioned operating sequence in reverse, making sure that the roto-translation backwards of the same bench (10 ) will be favored by the traction force exerted on the occasion by the aforementioned compensation jack (28).

It remains only to clarify a last important function of the machine according to the invention (M), consisting in the ability that it offers to the entire bench (10) to slide back and forth, regardless of its possible â € œuprightâ € or â € œright arrangement. € œ lying downâ €, with respect to the two aforementioned support legs (1a, 1b) or, better said, with respect to the two aforementioned pairs of upright rods (5, 6) intended to support the balance wheel (B).

This possibility serves to favor the user sitting on the bench (10), that is to say to bring him appropriately to the barbell (B) to be grasped, depending on whether it is resting on the pair of rear rods (5) or on the pair of rods front (6).

Naturally, once the user has adjusted the stroke of the bench (10) between these two pairs of rods (5, 6), he will have to lock the bench itself (10) to prevent it from making unwanted and accidental sliding due to the stresses that the user himself would easily transmit during his demanding exercises with a barbell (B) loaded with weights.

In this regard, please refer to the examination of figure 1 which shows how the bench (10), integral with the two underlying support longitudinal members (17, 18), occupies a position of maximum retraction, in correspondence with which the aforementioned second pin (35) protruding from the respective cylindrical rigid casing (33) mounted above the front side member (17) is inserted in the first of the aforementioned holes (36a) made on the aforementioned boxed plate (36) fixed on the inside of the aforementioned first leg (1a).

It is easy to understand how the installation of this second pin (35) within the respective hole of the plate (36) fixed to the supporting frame of the machine (M) produces the effect of preventing the bench (10) from sliding freely to the Interior of the latter.

However, this same figure shows how from the aforementioned â € œJâ € profile (11) that supports the bench (10) projects a second knob (38) with respective lever (38a), on the opposite side from that occupied by the aforementioned first knob (37).

Like what has been said for the lever (37a) in relation to the aforementioned first pin (31), this second lever (38a) is expected to be able to exert traction on a cable capable of causing Withdrawal of the second spine (35) and therefore its complete retraction inside the respective cylindrical casing (33).

By virtue of this retraction, the second pin (35) loses its coupling with the hole it previously occupied inside the aforesaid boxed plate (36).

Free from this constraint, the bench (10) can therefore be made to slide forward to the point desired by the user, exploiting the aforementioned coupling between the two aforementioned sleeves (19) - those that connect the two ends at the ends side members (17, 18) that support the bench itself (10) - and the two bars (9) hanging from the center of the two aforementioned stabilizing legs (1a, 1b).

Having reached a similar condition, the same user will have to leave the aforementioned lever (38a) to make the second pin (35) subject to the forward thrust of the respective spring contained in the cylindrical casing (33).

This will be enough to cause a new exit of this second pin (35) beyond the respective eyelet (34) and its insertion in another of the holes (36a) of the usual boxed plate (36) fixed on the inside of the aforementioned first leg (1a).

The attached figures show how the machine according to the invention (M) is equipped with further components of substantially traditional use.

First of all, we allude to a handle (39) fixed on the back of the pair of rear upright rods (5) at a higher level than the aforementioned platform (4).

Secondly, we allude to a pair of further hooks (40) with the concavities facing upwards which project on the front of the two rear upright rods (5) and which have the task of blocking any fall due to simple gravity of a balance wheel (B) that may have escaped the user's hand, who could otherwise cause serious damage to the user's physical safety.

Claims (10)

CLAIMS 1) Machine for isotonic training characterized by the fact of adopting the following components: - a bench (10) making use of a metal profile (20) substantially shaped like a â € œJâ € and therefore formed by a straight section facing upwards (11a) designed to frontally support the backrest (SC) of the bench itself ( 10), as well as a lower section (11b), substantially arranged at 90 ° with respect to the previous one (11a), suitable for supporting the respective session (SE) - a support structure (ST) of the bench itself (10), comprising a horizontal element (17, 18) and a vertical element (20) - a first pair of levers (24a, 24b) pivoted, thanks to a respective pair of pins (14a, 22a), to the aforementioned â € œJâ € profile (11) and to the aforementioned bearing structure (ST) and a second pair of levers (25a, 25b) pivoted, thanks to a respective pair of pins (15a, 23a), to the same â € œJâ € profile (11) and to the same bearing structure (ST), yes to allow the bench itself (10) to perform roto-translations forward and backward with respect to the same load-bearing structure (ST), passing through an upper end-of-stroke point, at which the respective backrest (SC) assumes a substantially vertical position , at a lower end-of-stroke point, at which the same backrest (SC) assumes an inclined position; - a headrest (P) which is fixed to the ends of the aforementioned pair of levers (25a, 25b) which extend beyond the aforementioned pivot pin (23a) located at the top of the aforementioned vertical element (20) of the load-bearing structure (ST) of the bench (10), in such a way that the same headrest (P) is arranged on the back of the aforementioned backrest (SC) of the bench (10) when the latter is in correspondence of its aforesaid upper end-of-stroke point and is placed instead at the top of the same backrest (SC) when the respective bench (10) is in correspondence with its lower end-of-stroke point; - means (32, 26aâ € ™, 26bâ € ™) suitable for allowing the locking of the aforesaid bench (10) in one or other of its aforesaid upper and lower end-of-stroke points. 2) Machine according to claim 1, characterized in that the aforementioned means suitable for locking the aforementioned roto-translations of the bench (10) consist of: - a first ear (26a), equipped with a respective hole (26aâ € ™), which projects below from the first (25a) of the two aforementioned second levers (25a, 25b) in an intermediate position between its aforementioned pivot pins (15a, 23a) - a second ear (26b), equipped with a respective hole (26bâ € ™), which projects from the first (25a) of the two aforementioned second levers (25a, 25b) in a substantially symmetrical position with respect to the aforementioned first ear (26a) and in any case in a more external position than the aforementioned pivot pin (23a) - a first pin (32) sliding horizontally, supported by a small shelf (30) on the side of the aforementioned vertical element of the supporting structure (ST) of the aforesaid bench (10) and able to penetrate alternately, under the thrust of a respective spring , inside the hole (26a ') of the aforementioned first ear (26a) and the hole (26b') of the aforementioned second ear (26b), at the moment in which one (26a ... ™) or the other (26bâ € ™) are placed in front of the pin itself (32), respectively in correspondence with the lower end point and the upper end point of the bench (10); it being provided that said pin (32) is also subject to the action of a cable capable of causing it to retract, overcoming the resistance of the aforementioned respective spring, which is controlled by means of a fixed lever (37a) in correspondence with the aforementioned â € œJâ € profile (11) of the bench (10). 3) Machine according to claim 1, characterized by the fact that the second (25b) of the two aforementioned second levers (25a, 25b) bears at the bottom an appendage arranged for cutting (27), in correspondence with which the jacket is pivoted of a compensation jack (28), whose extendable stem is fixed at a peg (29) which projects horizontally on the side of the aforementioned vertical element of the aforementioned load-bearing structure (ST) of the bench (20). 4) Machine according to one or more of the preceding claims, characterized in that the aforementioned seat (SE) of the bench (10) is mounted at the top of a cylindrical stem (13) able to slide axially inside a sleeve (12) welded to the front of the aforementioned lower section (11b) of the â € œJâ € profile (11), in an arrangement substantially parallel to that of the aforesaid upper straight section (11) of the same â € œJ section € œJâ € (11); it being provided that said stem (13) is associated with means (SP) adapted to selectively lock its position inside the respective sleeve (12). 5) Machine according to one or more of the preceding claims, characterized in that the aforementioned horizontal element (17, 18) of the aforementioned supporting structure (ST) of the bench (10) is mounted inside a support frame formed by two identical arched legs (1a, 1b), each of which has respective support feet at the two ends (2); it being provided that said arched legs (1a, 1b) are connected at the rear by a crosspiece (3). 6) Machine according to claim 5, characterized in that each of the aforesaid legs (1a, 1b) bears at the bottom, substantially in correspondence with its central portion, a cylindrical bar (9) hanging from two end brackets (9a). 7) Machine according to claim 6, characterized in that the aforementioned horizontal element of the aforementioned supporting structure (ST) of the bench (10) is substantially formed by a side by side pair of identical longitudinal members (17, 18) connected at the ends by two cylindrical sleeves (19) able to be inserted, with the possibility of alternative sliding, on the outside of the aforementioned cylindrical bars (9) hanging below the two aforesaid legs (1a, 1b); it being also provided that the aforementioned horizontal element (17, 18) of the load-bearing structure (ST) of the bench (10) adopts means (35) adapted to cooperate with corresponding means (36a) provided on the first (1a) of the two aforementioned legs (1a, 1b), in order to block the sliding of the aforementioned cylindrical sleeves (19) along the corresponding rods (9). 8) Machine according to claim 7, characterized in that the aforementioned locking means provided on the horizontal element (17, 18) of the aforementioned bearing structure (ST) consist of a second pin (35), sliding horizontally, able to penetrate, under the thrust of a respective spring, inside one of the holes (36a) provided on the front of a boxed plate (36) mounted on the inside of the first (1a) of the two arched legs (1a, 1b) of the aforementioned support frame; it being provided that said pin (35) is also subject to the action of a cable capable of causing it to retract, overcoming the resistance of the aforementioned respective spring, which is controlled by means of a fixed lever (38a) in correspondence with the aforementioned â € œJâ € profile (11) of the bench (10). 9) Machine according to one or more of the preceding claims, characterized in that it adopts, above the two aforementioned arched legs (1a, 1b), a symmetrically opposed pair of rear rods (5) which bear respective series of hooks on the front (5a) with the concavity facing upwards. 10) Machine according to one or more of the preceding claims, characterized in that it adopts, above the two aforementioned arched legs (1a, 1b), a symmetrically opposed pair of front rods (6) which bear respective series of hooks on the back (5a) with the concavity facing upwards.