Patent ID: 8746129
Filing Date: 2014-06-10
Classification: F15B

Abstract:
1. A rodless cylinder comprising: a cylinder tube including an inner hole and a slit parallel to the length of the cylinder tube and communicating with the inner hole; an inner moving unit arranged in the inner hole of the cylinder tube and movable along the length of the cylinder tube; an outer moving unit coupled to the inner moving unit by a connector extending through the slit and arranged on the outside of the cylinder tube; and an inner seal band extending along the slit to close the slit from inside the inner hole; wherein longitudinal ends of the inner seal band are restricted so that the inner moving unit passes through an intermediate portion of the inner seal band; wherein a band accommodating depression having a transverse inner surface substantially extending in a direction of a width of the slit and a wall surface inclined at an angle to the transverse inner surface is formed on each side of an inner opening of the slit; wherein the cross section of each of the transverse inner surfaces is an arcuately curved surface having the center of curvature located at a position nearer to the corresponding transverse inner surface than a center of the slit; wherein the band accommodating depression is formed in such a manner that in the case where one of transverse end portions of the inner seal band comes into contact with one of the wall surfaces, the other transverse end portion of the inner seal band comes into contact with the other transverse inner surface and a predetermined distance is set between the inner seal band and the inner opening of the slit; wherein the fluid introduced into the cylinder tube with the slit closed by the inner seal band acts on the inner moving unit thereby to move the inner moving unit; and wherein each of the wall surfaces is formed as a slope farther from the center line of the slit, the nearer to the center of the cylinder tube.