Safety trapped key interlock system
AssigneeEnex Group Ltd.
InventorWayne Hodgson
Life of this patent
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Abstract
A trapped key interlock system is disclosed. A pair of hollow tubular casings located one inside the other and each having a series of elongate slots are used. When the lock is in a locked condition the elongate slots are aligned as inner and outer pairs with engaging members extending through the pairs of slots is preventing rotational movement of the tubular casings relative to each other. The engaging members are biased towards this locked condition. On insertion of the correctly coded key the engaging members are caused to move against the biasing force out of engagement with the slots in the outer tubular casing thereby allowing the inner tubular casing to rotate relative to the outer tubular casing and moving the lock to an unlocked condition.
Claims21
A lock movable between a locking and an unlocking condition, the lock comprising:—
- (i) a first hollow tubular casing;
- (ii) a second hollow tubular casing disposed within the hollow portion of the first hollow casing;
- and
- (iii) a lock portion mounted within the second hollow casing,
- wherein the lock portion comprises a plurality of annular elements arranged side by side, each said annular element comprising an engaging member extending radially outwards from the periphery of the annular element, and
- wherein the first hollow casing comprises a plurality of first elongate notches extending substantially along the length of the first hollow casing, each first elongate notch disposed at a predetermined position on the periphery of the first hollow casing, and
- wherein the second hollow casing comprises a plurality of second elongate notches extending substantially along the length of the second hollow casing, each second elongate notch disposed at a predetermined position on the periphery of the second hollow casing such that, when said lock is in said locking condition, each of the first elongate notches substantially overlaps with a corresponding second elongate notch, and
- wherein each said engaging member is biased towards a position whereby said engaging member is disposed within one of said first elongate notches and its corresponding overlapping second elongate notch, defining said locking condition in which rotational movement of said second hollow casing within said first hollow casing is prevented, and
- wherein said lock is movable between said locking condition and an unlocking condition in which at least one said engaging member is disposed within a second elongate notch, but is not engaged with its corresponding overlapping first elongate notch, to allow for rotational movement of said second hollow casing within said first hollow casing.
A key comprising:—
- a handling portion for engagement by an operator;
- a coding portion for engaging and moving a respective receiving portion of a lock mechanism between a locked and unlocked conditions;
- a driving portion for transferring a rotational force applied to said handling portion to said lock causing a driven portion of said lock to rotate when in an unlocked condition, wherein said coding portion and said driving portion are axially separated along an axis of rotation of said key.
A lock comprising:—
- a receiving portion movable between a locked and unlocked condition upon receiving a respective key having a correctly coded key portion;
- a driven portion for engaging a driving portion of said key such that rotation of said driving portion causes rotation of said driven portion when said receiving portion is in an unlocked condition, wherein said receiving portion and said driven portion are axially separated along an axis of rotation of said lock.
-26. (canceled)
Dependencies are inferred from the claim text.