Linear actuator
AssigneeAktiebolaget Skf
InventorsJohannes Andrianus Maria Duits, Martin Voegelin
Life of this patent
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Abstract
Linear actuator device, comprising a housing (2), an externally threaded screw (5), a piston (9) and an internally threaded extended nut (7), where the extended nut (7) comprises a plurality of longitudinal segments (40) having longitudinal edges (39) parallel to a center axis (18) of the internally threaded nut (7), where each segment (40) has an identical radius of curvature and an angle of curvature of less than 360°, so that the circumference of the internally threaded nut (7) is formed by at least two segments (40). One advantage of the invention is that linear actuators of different lengths can be manufactured in an easy and cost-effective manner.
Claims23
An internally threaded tube comprising a plurality of longitudinal segments each having internal threads, two longitudinal edges extending generally parallel to a central axis of the internally threaded tube, a radius of curvature about the axis, and an angle of curvature of less than 360 degrees, the radius of curvature of each segment being substantially identical to the radius of each other segment, the internally threaded tube being formed by coupling at least two segments along the longitudinal edges, and wherein
- said plurality of segments are assembled such that each segment is longitudinally displaced along the central axis with respect to at least one other segment.
A segment of a threaded tube, the tube segment comprising an arcuate portion having two longitudinal edges extending parallel to a central axis of the tube and an angle of curvature with respect to the axis of less than 360 degrees, a plurality of radial grooves being provided on a radially inner surface of the arcuate portion so as to form a part of the internal thread of the tube, the grooves being adapted to connect with corresponding grooves on at least one other segment with an identical radius of curvature such that a complete internal thread is formed when the at least two segments are assembled about the central axis to form the tube, and wherein
- said plurality of segments are assembled such that each segment is longitudinally displaced along the central axis with respect to at least one other segment.
A linear actuator device, comprising:
- a housing,
- an externally threaded screw,
- a piston, and
- an internally threaded extended nut including an internally threaded tube having a central axis and being formed of a plurality of longitudinal segments, each segment having internal threads, two longitudinal edges extending generally parallel to the central axis, a radius of curvature about the axis, and an angle of curvature of less than 360 degrees, the radius of curvature of each segment being substantially identical to the radius of each other segment, the internally threaded tube being formed by coupling at least two segments along the longitudinal edges, and wherein
- said plurality of segments are assembled such that each segment is longitudinally displaced along the central axis with respect to at least one other segment.
A method of producing an internally threaded tube with a central axis, comprising the step of assembling a plurality of longitudinal segments each having an internal thread and two longitudinal edges extending generally parallel to the central axis, each segment providing an arcuate portion of the tube, and the segments being assembled so that each longitudinal edge of each segment is disposed against a separate one of the edges of another one of the segments so as to form a tube with a circular cross-section, and wherein
- the segments are assembled such that each segment is displaced longitudinally along the central axis with respect to at least one other segment.
Dependencies are inferred from the claim text.