Tongue lock for stackable containers
AssigneeInternational Paper Company
InventorStanley L. Fry
Life of this patent
Estimating the term…
Abstract
A tongue shaped friction lock is integrally formed in a dust cover or a bottom panel of an open-topped container and positioned to capture the stacking tabs of an adjacent open-topped container. The friction lock provides a small opening through which a stacking tab may be inserted, while at the same time pushing up a locking flap, which pivots up and frictionally engages the stacking tab. A strip of reinforcing tape is embedded within the dust cover and allows one to remove and reuse the dust cover without tearing the tongue lock or the surrounding portions of the dust cover.
Claims21
A friction locking mechanism formed in a flexible material, comprising at least one flap having a front edge, a back pivot line, and two side incision lines, said at least one flap bordering at least one cut-out slot in said flexible material along said front edge, said cut-out slot having a front edge, a back edge, and two side edges, wherein said flap can pivot along said back pivot line in an upwards direction.
A flexible material for use as a top or bottom panel of a container, having a locking mechanism for securing the flexible material to the container, the locking mechanism comprising:
- at least one flap having a front contact edge, a back pivot line, and two side incision lines, said flap integrally attached to said flexible material along said back pivot line,
- at least one cut-out slot in said flexible material inwardly spaced from at least one side edge of said flexible material, said cut-out slot having a front edge, a back edge, and two side edges,
- said front contact edge of the at least one flap bordering said back edge of the at least one cut-out slot,
- wherein said flap can pivot along said back pivot line in an upwards direction.
A method for fastening a flexible material onto an open-topped container, said container having a bottom panel, four side walls and stacking tabs extending from at least two opposing side walls of said four side walls, and said flexible material having locking flaps bordering cut-open slots, comprising the steps of:
- inserting said stacking tabs through said cut-open slot, said stacking tabs contacting said locking flaps during said insertion,
- bending said locking flaps upward along a back pivot line by the pressure exerted by the stacking tabs extending fully through said cut-open slots,
- wherein said stacking tabs are held secure by a frictional force between said locking flaps and said flexible material.
Dependencies are inferred from the claim text.