| 摘要 |
<p>1443113 Bookbinding; filing papers MINNESOTA MINING & MFG CO 12 Aug 1974 [13 Aug 1973] 35500/74 Headings B6A and B6E A binder element, e.g. of plastics material, for permanently binding together apertured sheets 21, comprises a first spine 17 having studs 27 provided with ratchet teeth 29, and a second spine 19 having complementary openings each with a wall provided with at least one ratchet tooth 41 thereon extending into the opening and adapted to engage the ratchet teeth of the corresponding stud, a locking block 43 for each opening being adapted to fit into the opening to hold the ratchet teeth of the two spines in engagement. Each locking block is attached adjacent its respective opening by a thin web 45 which may be broken, or may act as a hinge, as the block is forced into the opening. The protruding portions of the studs are cut off. The studs may be of circular, oval or rectangular cross-section. In the latter case, only one face of each stud, except the centre stud (33) is provided with ratchet teeth, Fig. 2 (not shown). The spines have sheet engaging points 49, 51.</p> |
