Recloseal Ltd. of Nottingham, England, has developed a linear over-center toggle latch, produced by plastic extrusion. Like a conventional toggle latch, the Recloseal latch tends naturally to maintain itself in the closed position, whether or not any external forces are acting.
By contrast with traditional metal latches, the Recloseal engages along its whole length, enabling it to close securely regardless of where the parting forces act. Closure forces are distributed evenly particularly useful when the latch is applied to soft materials or to tension fabrics.
Production by extrusion means that the latch can be made (or cut) to virtually any length. Both the design (for which patents are pending) and the extrusion process are fully scalable to suit applications ranging from the miniature to the industrial scale, Recloseal claims. The need for separate rubber seals may be obviated; alternatively a rubber seal can be co-extruded directly into the latch.
The latch is co-extruded using rigid and flexible plastics through a single die. The softer plastics form a living hinge that flexes to give the latching action. Unlike a conventional hinge there are no pins, tubes or cavities to capture dust or microorganisms, and the plastics are corrosion-free. Ease of cleaning and sterilization may facilitate medical and pharmaceutical applications.
Having initially aimed the latch at the re-usable transit packaging market, the company now is examining other potential applications, including industrial pipe insulation and protection, closures for medical packaging, and cable trunking for electrical control panels.
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