Shaft locking device
AssigneeNHK Spring Co., Ltd.
InventorYoshiharu Kitamura
Life of this patent
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Abstract
A shaft-locking device which locks rotation of a movable shaft by a clamping force of a coil spring closely surrounding a fixed shaft and a movable shaft. Both sides of the coil spring are inserted surrounding the fixed shaft and a central portion of the coil spring surrounds the movable shaft. In case of rotation of the movable shaft on both sides, the locking torque is applied. Further, the closed state of the coil spring to the movable shaft is maintained uniformly without any relation to operation by separating the end portions of the coil spring at the movable shaft side of the coil spring from an outer circumference of the movable shaft so that a constant locking torque may be always obtained.
Claims11
A shaft-locking device for locking rotation at any arbitrary position of an article requiring control of an inclined angle, said device comprising
- a movable bracket secured to the article requiring control of an inclined angle,
- a fixed bracket secured to a supporting member for supporting the article,
- two fixed shafts integrally secured to said fixed bracket,
- a movable shaft rotatably secured to the movable bracket,
- the movable shaft being a stepped shaft with two small diameter portions being mounted within the fixed shafts and an outer diameter of a large diameter portion of the movable shaft being at least equal to the outer diameter of said fixed shafts and one of said fixed shafts being located between said movable bracket and said large diameter portion of said movable shaft,
- a continuous coil spring spiraling in a single direction surrounding the fixed shafts and the movable shaft in a closely contacted state,
- opposite end portions of said coil spring surrounding said fixed shafts to securely lock rotation of said movable bracket at any arbitrary position until an external force is applied to the movable bracket which is greater than a locking force exerted by the end portions of the coil spring on the fixed shafts to release said coil spring from said fixed shaft by expansion of said coil spring.
Dependencies are inferred from the claim text.