| 摘要 |
<p>This invention relates to a frangible strip of clips and a method of making same. The clips are used for closing bags containing bread, food produce and the like and the clips are made from laminar plastics material. The strip is characterized by breaking portions at which each individual clip is separable from its longitudinal neighbours. These portions are coextensive, longitudinally of the strip, with the line of separation which divides off each clip from its longitudinal neighbours and which is found without removal of material from the strip. This line is achieved by shearing the material of the strip while bowing it about a longitudinal axis so as to present a curved surface to an oncoming shearing tool which has an oppositely curved surface. The extent of intersection of the opposite curve defines the length of the line of the separation. The breaking portion is adjacent each end of the line. The clips during severance, suffer apparent lateral contraction but no longitudinal distortion. This invention solves the problem of avoiding the production of chips of material or of snagging projections upon the separation of clips from the strip.</p> |
