GB1095620A - Unitary hinge - Google Patents

Abstract

1,095,620. Hinged box. WESTHEM CORPORATION Ltd. Oct. 12, 1966, No. 45509/66. Addition to 1,025,826. Heading B8P. [Also in Division E2] A one-piece ring box, injection moulded from polypropylene, has an integral hinge with a spring biasing action to open the box on release of a securing catch. In Figs. 5 and 7, which are sectional and plan views respectively, the box comprises a base 31 having a bottom 33, end walls 34, and sloping walls 35 and 36 at the front and rear, with a lid 32 having ends 37, and curved front and rear walls 38 and 39, the base and lid being connected by the hinge assembly shown generally at 40; there is also a front catch 50. The rear walls 36 and 39, of the base and lid are joined in end to end relationship, at either side of a central spring arm 16<SP>11</SP> and connecting arm 19<SP>11</SP>, by flexible bending lines 2011 and 2111 formed adjacent to V-shaped depressions in the outer wall surfaces. The spring arm 16<SP>11</SP>, integral with lid rear wall 39, is formed during moulding inclined outwardly from 39, and its other end connects along a flexible bending line 17<SP>11</SP> to a connecting arm 19<SP>11</SP>, itself flexibly integrally connected at 18<SP>11</SP> to the base rear wall 36. Above and below bending lines 2011 and 21<SP>11</SP>, the lid and base rear walls are bent in at 40 and 42 to enclose the part of the box between the hinge and end walls, when the box is closed; the edges of the turned in portions abut on closure to form stops for the hinge. On closing the box, the spring arm 16<SP>11</SP> is stressed by connecting arm 19<SP>11</SP>, into alignment with rear wall 39, and remains so deformed until the catch 50 is released, when, due to the elastic properties of the polypropylene, it returns to its original angular relationship with 39 and the lid opens to the position shown in Fig. 5. The box has two serrated clamping parts 43 to hold a ring 44; the box inner surfaces may be coated with flocking and the outside suitably embossed. The box may alternatively be moulded from other synthetic thermoplastics, such as nylon, or the hinge may be separated from but secured to the box.