Pneumatic actuator

A pneumatic actuator, comprising:

• a containment jacket (2) comprising a first bell-shaped element and a second bell-shaped element coupled in a sealed fashion at respective free edges;
• a rolling membrane (9) mounted in a fluid-tight fashion between the first bell-shaped element and the second bell-shaped element, the rolling membrane (9) dividing a space inside the containment jacket (2) into two separate chambers;
• an activating bar (14) slidably inserted through a through-hole (6) in the first bell-shaped element and having a first end (15) located inside the containment jacket (2) and engaged with the rolling membrane (9), and a second end (16) located outside the containment jacket (2), the activating bar (14) being able to move between a first operating position of maximum extension outside the containment jacket (2) and a second operating position of maximum retraction inside the containment jacket (2);
• elastic means (22) acting on the rolling membrane (9) and the activating bar (14) to push the activating bar (14) towards its first operating position;
• a fixed part (23) integral with the inside of the jacket (2) and having a shape extending along a main axis of extension (X),
• a mobile part (26) mounted inside the containment jacket (2), being slidably connected to the fixed part (23) and operatively connected to the activating bar (14) in such a way that it moves with the latter;
• the actuator being characterised in that the fixed part (23) also has at least a core (25) made of ferromagnetic material extending along the main axis of extension (X);
• and also being characterised in that it also comprises at least two magnets (29) fixed to the mobile part (26) and mounted on diametrically opposed sides relative to the main axis of extension (X) of the fixed part (23), the magnets (29) having the same radial orientation of magnetic polarization relative to the main axis of extension (X);
• also being characterized in that the mobile part (26) can move relative to the fixed part (23) between a first position of maximum magnetic uncoupling between the magnets (29) and the ferromagnetic core (25), and a second position of maximum magnetic coupling between the magnets (29) and the ferromagnetic core (25);
• and also being characterized in that it also comprises a sensor (30) for detecting a magnetic field mounted at one end of the ferromagnetic core (25), wherein the operating position of the activating bar (14) can be determined based on the magnetic field detected by the sensor (30);
• and
• wherein the pneumatic actuator has a ratio of between 1 and 2 between the length of the ferromagnetic core (25) and the length of each of the magnets (29) measured parallel with the main axis of extension (X).

A pneumatic actuator, comprising:

• a containment jacket (2) comprising a first bell-shaped element and a second bell-shaped element coupled in a sealed fashion at respective free edges;
• a rolling membrane (9) mounted in a fluid-tight fashion between the first bell-shaped element and the second bell-shaped element, the rolling membrane (9) dividing a space inside the containment jacket (2) into two separate chambers;
• an activating bar (14) slidably inserted through a through-hole (6) in the first bell-shaped element and having a first end (15) located inside the containment jacket (2) and engaged with the rolling membrane (9), and a second end (16) located outside the containment jacket (2), the activating bar (14) being able to move between a first operating position of maximum extension outside the containment jacket (2) and a second operating position of maximum retraction inside the containment jacket (2);
• elastic means (22) acting on the rolling membrane (9) and the activating bar (14) to push the activating bar (14) towards its first operating position;
• a fixed part (23) integral with the inside of the jacket (2) and having a shape extending along a main axis of extension (X);
• a mobile part (26) mounted inside the containment jacket (2), being slidably connected to the fixed part (23) and operatively connected to the activating bar (14) in such a way that it moves with the latter;
• the actuator being characterised in that the fixed part (23) also has at least a core (25) made of ferromagnetic material extending along the main axis of extension (X);
• and also being characterized in that is also comprises at least two magnets (29) fixed to the mobile part (26) and mounted on diametrically opposed sides relative to the main axis of extension (X) of the fixed part (23), the magnets (29) having the same radial orientation of magnetic polarization relative to the main axis of extension (X);
• also being characterized in that the mobile part (26) can move relative to the fixed part (23) between a first position of maximum magnetic uncoupling between the magnets (29) and the ferromagnetic core (25), and a second position of maximum magnetic coupling between the magnets (29) and the ferromagnetic core (25);
• and also being characterized in that it also comprises a sensor (30) for detecting a magnetic field mounted at one end of the ferromagnetic core (25), wherein the operating position of the activating bar (14) can be determined based on the magnetic field detected by the sensor (30);
• and wherein the dimension of each of the magnets (29) measured parallel with the main axis of extension (X) is greater than the dimension measured in the radial direction relative to the main axis of extension (X), the latter in turn being greater than the dimension measured tangentially relative to the main axis of extension (X).

A pneumatic actuator, comprising:

• a containment jacket (2) comprising a first bell-shaped element and a second bell-shaped element coupled in a sealed fashion at respective free edges;
• a rolling membrane (9) mounted in a fluid-tight fashion between the first bell-shaped element and the second bell-shaped element, the rolling membrane (9) dividing a space inside the containment jacket (2) into two separate chambers;
• an activating bar (14) slidably inserted through a through-hole (6) in the first bell-shaped element and having a first end (15) located inside the containment jacket (2) and engaged with the rolling membrane (9), and a second end (16) located outside the containment jacket (2), the activating bar (14) being able to move between a first operating position of maximum extension outside the containment jacket (2) and a second operating position of maximum retraction inside the containment jacket (2);
• elastic means (22) acting on the rolling membrane (9) and the activating bar (14) to push the activating bar (14) towards its first operating position;
• a fixed part (23) integral with the inside of the jacket (2) and having a shape extending along a main axis of extension (X);
• a mobile part (26) mounted inside the containment jacket (2), being slidably connected to the fixed part (23) and operatively connected to the activating bar (14) in such a way that is moves with the latter;
• the actuator being characterised in that the fixed part (23) also has at least a core (25) made of ferromagnetic material extending along the main axis of extension (X);
• and also being characterized in that it also comprises at least two magnets (29) fixed to the mobile part (26) and mounted on diametrically opposed sides relative to the main axis of extension (X) of the fixed part (23), the magnets (29) having the same radial orientation of magnetic polarization relative to the main axis of extension (X);
• also being characterized in that the mobile part (26) can move relative to the fixed part (23) between a first position of maximum magnetic uncoupling between the magnets (29) and the ferromagnetic core (25), and a second position of maximum magnetic coupling between the magnets (29) and the ferromagnetic core (25);
• and also being characterized in that it also comprises a sensor (30) for detecting a magnetic field mounted at one end of the ferromagnetic core (25), wherein the operating position of the activating bar (14) can be determined based on the magnetic field detected by the sensor (30);
• and
• wherein the mobile part (26) consists of two concentric bushings between them forming two housings (35) in which the magnets (29) are inserted.