| 摘要 |
1,091,450. Cutting tools. GENERAL ELECTRIC CO. Dec. 23, 1965 [Feb. 16, 1965], No. 54544/65. Heading B3B. A tool comprises a shank 4 having a recess and a seat 2 for a cutting bit 1 and a locking pin 3 which is loosely threaded to the lower portion 15 of a hole in the shank beneath the cutting bit and seat; when tightened down, a tapered portion 17 of the pin 3 makes wedging contact with an offset tapered portion 14 of this hole to force the upper end of the pin 3 against the side of a hole 21 in the cutting bit thereby locking the bit against the shoulder face of the recess. In order to hold the cutting bit 1 firmly on seat 2 the pin 3 has an enlarged portion 18 positioned to make contact with the side of hole 21 near the lower face of the cutting bit while the shoulder of the recess is disposed at a slight angle with the face of the cutting bit so that the latter contacts the shoulder near its upper edge. To facilitate the wedging movement of the pin 3 the threaded portion 16 is made very slightly convex. In a modification (Fig. 6, not shown), the seat is omitted. In another modification (Fig. 5, not shown) the cutting bit is formed with positive rake and the hole therein and the complementary portion of the locking pin are tapered. In this embodiment the axis (C-C) of the hole in the cutting bit is offset from the axis of the pin and shank hole in a direction away from the shoulder of the recess. Triangular, square or circular cutting bits (Figs. 7-9, not shown) may be employed. |
