Patent ID: 7313978

Claim:
A linear motion device ( 10 ) including a worm ( 14 ) provided with grooves ( 54 ), comprising: a box-shaped body ( 12 ); a housing seat defined internally in the shaped body and forming a partial delimitation of said worm ( 14 ); a mobile device ( 52 ) which temporarily engages with at least one of the grooves ( 54 ) of the worm; and pressure means ( 40 ) for moving the mobile device ( 52 ) in contact with at least one of the grooves ( 54 ), said pressure means comprising a pneumatic pistons wherein the box-shaped body ( 12 ) comprises: opposite sidewalls ( 24 , 26 ) and an upper edge or mouthpiece ( 20 ) and the housing seat and partial delimitation of the worm ( 14 ) is obtained in the central part of the body ( 12 ), said worm being crosswise extended and having a lower part delimited by an internal face of the base of the same body, and side portions of said worm ( 14 ) being delimited by opposite shoulders ( 16 , 18 ) developing in height for a limited portion, such that opposing upper ends of said opposite shoulders are spaced a distance from the mouthpiece or edge ( 20 ) of said body ( 12 ); and the mobile means ( 52 ) include at least one rod or pin associated with said pressure means ( 40 ) and extending crosswise inside the box-shaped body ( 12 ) and parallel to said grooves ( 54 ) and inserted in opposite guiding slots ( 52 ′) obtained on the internal face of the sidewalls ( 24 , 26 ) of the body ( 12 ).