One-way twist lock for telescopic tubes
AssigneeSeaway Supply Company
InventorsHarrison William Hine, Veli A. Saarinen
Life of this patent
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Abstract
A locking mechanism operates to selectively lock and unlock a pair of telescopic tubes. A lock base is fixed to one tube and is formed with an eccentric pin. A lock ring is slidably disposed within the other tube and is slipped over and carried by the eccentric pin. The external configuration of the lock pin and cross section of its associated tube are polygonal or multi-sided to prevent relative rotation. By relatively rotating the tubes in only one direction locking is accomplished and by relatively rotating the tubes in just the opposite direction unlocking is effected. The overall end-to-end length of the tubes can be adjusted by unlocking them, sliding one axially relative to the other and then locking them again.
Claims10
A twist lock mechanism for telescopic tubes, comprising:
- a. a first tube having a multi-sided cross section;
- b. a second tube telescopically disposed within the first tube;
- c. a split lock ring formed with a bore and slidably disposed within the first tube, the lock ring having a multisided external periphery sized to prevent rotation between the lock ring and first tube and a notch in one end intersecting both sides of said split;
- d. a lock base fixed to one end of the second tube;
- e. an eccentric pin extending from the lock base and disposed within the bore of the lock ring, the eccentric pin and lock ring being structured to wedge and accomplish locking when the tubes are relatively rotated in one direction;
- and,
- f. turn limiting means for preventing the eccentric pin and lock ring from locking when the tubes are relatively rotated in the opposite direction.
A one-way twist lock mechanism for telescopic tubes, comprising:
- a. a first tube having a rectangular cross section;
- b. a second tube telescopically disposed within the first tube;
- c. a resilient split lock ring formed with a bore and slidably disposed within the first tube, the lock ring having a rectangular external periphery sized to prevent rotation between the lock ring and first tube;
- d. a lock base fixed to one end of the second tube;
- e. an eccentric pin extending from the lock base and disposed within the bore of the lock ring, the eccentric pin and lock ring being structured to wedge and accomplish locking when the tubes are relatively rotated in one direction;
- f. said split defining means along one side of the lock ring by which it can be laterally slipped over and removed from the eccentric pin;
- and,
- g. turn limiting means including a peg projecting laterally outwardly from the eccentric pin, and a notch in one end of said ring intersecting both sides of said split to define
- a pair of stop shoulders formed by the lock ring and positioned on opposite sides of the peg to limit angular displacement by the peg
- wherein engagement of one stop shoulder by the peg prevents locking between the eccentric pin and lock ring, and, engagement of the other stop shoulder by the peg prevents the eccentric pin and lock ring from exceeding a predetermined locking force and becoming jammed.
Dependencies are inferred from the claim text.