Patent Description:
One of those primarily in use is pneumatic equipment, in which the resistance the user encounters to perform exercise is determined by the compression of a pneumatic actuator, the main components of which include a cylinder, a piston and a piston rod.

Specifically, the compression of the pneumatic actuator occurs when the piston moves inside the cylinder due to the motion of the piston rod.

Performing exercises against this type of resistance is advantageous for improving explosive contractions throughout the entire motion, as the force required to compress a pneumatic actuator does not decrease after an initial impulse, which is not the case during the lifting of weights due to the momentum these acquire.

Pneumatic training equipment generally consists of a pneumatic actuator, which may be connected to an air tank and which, through the operation of a valve system, is able to increase the pressure by drawing air from a source of compressed air or to reduce the pressure by dispersing air into the atmosphere.

This pressure regulation thus makes it possible to change the force required to compress the pneumatic actuator, which increases as the pressure inside the cylinder of the actuator increases.

In early pneumatic equipment, such as that described in patent <CIT>, the top of the piston rod has attached to it a lever that the user can move to perform exercises by directly compressing the pneumatic actuator.

However, in more versatile pneumatic equipment, as illustrated in patent <CIT>, the top of the piston rod has attached to it a pulley, on which passes a cable, having one end anchored to a fixed point of the equipment, and having a second end passing on a second pulley so that it can be pulled in different directions by the user and so that the pneumatic actuator can be compressed for a length equal to twice its maximum stroke, corresponding to the complete movement of the piston inside the cylinder.

Likewise, in more recent pneumatic equipment, as illustrated in patent <CIT>, the cable passing over the pulley of the piston rod is anchored at one end to a fixed point of the apparatus and at the opposite end to a pulley block through which passes a second cable which, when pulled by the user, compresses the pneumatic actuator due to the motion of the cable passing over the pulley of the piston rod.

Although, in the latter type of equipment, the purpose of the hoist is to further increase the length of the cable pulled by the user to compress the pneumatic actuator, using the systems described in patents <CIT> and <CIT>B2A1, the length of the cable pulled by the user, for construction practicality reasons, is not more than <NUM> times the stroke of the pneumatic actuator. This is a limitation for performing exercises such as sprints and changes of direction against resistance, which are critical for improving sports performances, but which generally require resistance cables longer than <NUM> meters.

Other relevant references in the state of the art are the patent applications:.

In light of these limitations, the first purpose of the present invention is to make the resistance offered by a pneumatic actuator also applicable to the performance of exercises such as sprints and changes of direction where a cable greater than <NUM> meters is required.

A second purpose of the present invention is to also make constant the resistance generated by a pneumatic actuator throughout the pull of the cable being operated by the user to perform out exercises.

Indeed, the force required to compress a pneumatic actuator generally increases progressively as the compression of the air (and thus the pressure) inside the pneumatic actuator increases.

The present invention achieves the first purpose by attaching one end of the cable passing over the pulley on the piston rod of the pneumatic actuator to a rotational shaft, preferably mounted on two bearings bolted within the equipment, and attaching to the rotational shaft a larger-diameter pulley wheel about which a second cable is wound with one end free to be pulled to perform exercise.

In this way, the user performs the exercise by pulling the cable wound on the pulley wheel so as to set the rotational shaft in rotation, which winds the cable passing over the pulley bound to the piston rod about itself, thus compressing the pneumatic actuator.

In the system pertaining to the new invention, the length of the cable pulled by the user to perform exercise is thus equal to the length of the stroke of the pneumatic actuator multiplied by two as a result of the first passage of the cable over the pulley of the piston rod on the actuator, and further multiplied by the ratio between the diameter of the pulley wheel on which the cable pulled by the user is wound and the diameter of the shaft on which the cable passing over the pulley on the piston rod is wound.

For example, in the new invention, using a pneumatic actuator with a stroke of <NUM> meter, a rotational shaft with a diameter of <NUM> millimetres and a pulley wheel with a diameter of <NUM> millimetres, a <NUM>-metre-long cable can be obtained to perform exercise.

The second purpose, on the other hand, is achieved by making the rotational shaft, about which the cable passing over the pulley on the piston rod of the pneumatic actuator is wound, conical in shape with decreasing diameter.

Indeed, in such a way, as the cable passing over the piston rod is wound about the rotational shaft from a larger diameter to a smaller diameter to compress the pneumatic actuator, the ratio between the diameter of the shaft about which the cable passing over the pulley on the piston rod is wound and the diameter of the pulley wheel about which the cable pulled by the user is wound becomes more and more favourable for pulling, compensating for the increase in resistance generated by the growth of pressure inside the pneumatic actuator during its compression.

The invention relates to a physical training apparatus as claimed in claim <NUM>. The additional features are defined by the dependent claims.

This invention will now be described in more detail with reference to the figures, which illustrate a non-limiting embodiment of the invention, wherein:.

As can be seen from <FIG>, the present invention concerns a physical training apparatus comprising a supporting structure (<NUM>) onto which is attached a pneumatic actuator (<NUM>), comprising a piston rod (<NUM>), connected by an air pipe to a source of compressed air (<NUM>), such as a compressor, being preferably interposed an air tank (<NUM>) between the pneumatic actuator (<NUM>) and the source of compressed air (<NUM>). Between the air tank (<NUM>) and the source of compressed air (<NUM>) is interposed a pressure regulation system, which is composed of two valves, one for the inlet (105a) and one for the outlet (105b) of air. The inlet valve (105a), when open, allows air to flow from the source of compressed air (<NUM>), with increased pressure, to the system comprising the air tank (<NUM>) and the pneumatic actuator (<NUM>), increasing its pressure. In contrast, the outlet valve (105b), when open, allows the pressure within the same system to decrease by dispersing air into the atmosphere.

Ideally, a pressure sensor (<NUM>), such as an electronic pressure transmitter, is connected to the pneumatic actuator (<NUM>) to measure the change in pressure within the pneumatic actuator (<NUM>) itself.

It must be premised that the term "fixed pulley" means a pulley animated by rotary motion only, which does not change its coordinates in space, while the term "mobile pulley" means a pulley that, in addition to rotating, also moves in space, for example in a vertical direction.

Attached to the outer end of the piston rod (<NUM>) of the pneumatic actuator (<NUM>) is a mobile pulley (<NUM>) on which passes a first cable (<NUM>) with a first end (109a) anchored to the supporting structure (<NUM>) and a second end (109b) attached to a rotational shaft (<NUM>), which is in turn preferably mounted on two bearings (111a; 111b) that are also bolted to the supporting structure (<NUM>). The rotational shaft (<NUM>) is integral with a fixed pulley (<NUM>), with a diameter greater than the diameter of the rotational shaft (<NUM>), on which a second cable (<NUM>) having one end (<NUM>) free to be pulled to perform exercise is attached and freely windable.

When not in use, the piston rod (<NUM>) is kept ejected by the pressure present inside the pneumatic actuator (<NUM>); the first cable (<NUM>) passing over the mobile pulley (<NUM>) on top of the piston rod (<NUM>) is taut and unwound from the rotational shaft (<NUM>); and the second cable (<NUM>) attached to the fixed pulley (<NUM>) is wound around it.

When the user pulls the free end (<NUM>) of the second cable (<NUM>) to unwind it from the fixed pulley (<NUM>), this sets the rotational shaft (<NUM>) connected to it in rotation. Consequently, the first cable (<NUM>) connected to the rotational shaft (<NUM>) begins to wind about it and, as it shortens, it compresses the piston rod (<NUM>) of the pneumatic actuator (<NUM>) over which it passes.

Two further pulleys (115a; 115b) can also be attached to the supporting structure (<NUM>), the first pulley (115a) attached to the supporting structure (<NUM>) frontally to the fixed pulley (<NUM>), and the second pulley (115b) freely slidable along a guide mechanism (<NUM>) also fixed to the supporting structure (<NUM>) perpendicularly to the axis of the fixed pulley (<NUM>).

This latter pulley (115b) can be locked using an appropriate locking system (<NUM>), for example with a positioning plunger, at different heights on the guiding mechanism (<NUM>), so as to change the point from which the user can pull the end (<NUM>) of the second cable (<NUM>) to perform the exercise.

As shown in <FIG>, to keep constant the pull on the second cable (<NUM>) wound about the fixed pulley (<NUM>) throughout the user's movement, the rotational shaft (<NUM>) about which the first cable (<NUM>) passing over the piston rod (<NUM>) is wound, is conical in shape.

Thus, when the pneumatic actuator (<NUM>) is compressed, the ratio between the diameters of the rotational shaft (<NUM>) and the fixed pulley (<NUM>), on which the second cable (<NUM>) pulled by the user is wound, varies, becoming more favourable to be pulled by the user by counterbalancing the increase in resistance that must be overcome to compress the pneumatic actuator (<NUM>).

In one variant of the invention, as shown in <FIG>, the first end (109a) of the first cable (<NUM>), opposite to that attached to the rotational shaft (<NUM>), protrudes outside the supporting structure (<NUM>), guided by another pulley (<NUM>), and is held in place by an appropriate stop (<NUM>), complemented by a pin (<NUM>) attached to said first cable (<NUM>) so as to allow it to be pulled outwards, if necessary, to perform exercises directly using the first cable (<NUM>).

In addition, in this variant the source of compressed air (<NUM>) is connected to the actuator (<NUM>) and the air tank (<NUM>) through a tube equipped with an appropriate two-way T-joint (<NUM>), which makes it possible, through the operation of an appropriate valve (<NUM>), to shut off the passage of air into the air tank (<NUM>) and to make the source of compressed air (<NUM>) communicate only with the pneumatic actuator (<NUM>).

In this way, the user can choose whether to perform exercises with a constant resistance or to perform exercises using incremental resistance, since shutting off the passage of air into the air tank (<NUM>) causes a more pronounced increase in pressure inside the pneumatic actuator (<NUM>) during its compression, which is not fully counterbalanced by the use of a conical rotational shaft (<NUM>).

In a further variant of the apparatus (<NUM>), as shown in <FIG>, the first cable (<NUM>) is guided by a special pulley system (123a, 123b, 123c, 123d), which acts as a hoist to double once more the length of the first cable (<NUM>) to be wound about the rotational shaft (<NUM>) to compress the pneumatic actuator (<NUM>) and, consequently, to increase the length of the second cable (<NUM>) wound about the fixed pulley (<NUM>) that must be pulled to cause the first cable (<NUM>) be wound about the rotational shaft (<NUM>).

<FIG> schematically shows an alternative pressure regulation system interposed between the air tank (<NUM>) and the source of compressed air (<NUM>), which enables the pressure inside the pneumatic actuator (<NUM>) to be configured by means of a piloted pressure regulator (<NUM>) controlled by an air inlet valve (125a) and an air outlet valve (125b) operable using two respective buttons (126a; 126b).

Claim 1:
A physical training apparatus comprising a supporting structure (<NUM>), to which is fixed a pneumatic actuator (<NUM>) connected to a source of compressed air (<NUM>) through a piping with at least one air inlet valve (105a) and one air outlet valve (105b), said pneumatic actuator being provided with a piston rod (<NUM>) supporting at least a mobile pulley (<NUM>), on which passes a first cable (<NUM>) having a first cable end (109a) anchored to the supporting structure (<NUM>) and a second cable end (109b) attached to a rotational shaft (<NUM>), said apparatus (<NUM>) being characterised in that it comprises a fixed pulley (<NUM>) integral with the rotational shaft (<NUM>) and having a diameter larger than the diameter of the rotational shaft (<NUM>), and a second cable (<NUM>), wound on said fixed pulley (<NUM>), that can be pulled to perform exercises for a length that is greater than that of the first cable (<NUM>) in the same ratio as that which exists between the diameter of the fixed pulley (<NUM>) and the diameter of the rotational shaft (<NUM>), the rotational shaft (<NUM>) being conical in shape and having a decreasing diameter so as to progressively vary the ratio between the circumference of the rotational shaft (<NUM>) about which the first cable (<NUM>) is wound and the circumference of the fixed pulley (<NUM>) about which the second cable (<NUM>) pulled by the user is wound, so as to keep the force exerted by the user constant despite the increase in pressure inside the pneumatic actuator (<NUM>) during its compression.