| 摘要 |
458,778. Pencil-leads. EAGLE PENCIL CO., 703, East 13th Street, New York, U.S.A.- (Assignees of Chesler, 1.) June 25, 1935, No. 18212. Convention date, July 6, 1934. [Class 146 (iii)] In a pencil-lead for propelling pencils having sharp edges longitudinally thereof and equidistant from its axis, the edges are arranged peripherally in a series of pairs of adjacent edges, the surface between each pair and the consecutive pair being concave. Preferably, the edges 10<1> are separated by an angular distance of 30‹ and the two pairs of edges 10, 101 by 60‹. The arrangement is symmetrical round the axis of the lead. The concavity 13 between the edges 10<1> is greater than that between the pairs 10, 10<1> and is preferably arranged so that each writing edge is approximately rectangular. |
