| 摘要 |
1,092,709. Cutting tools. TREVATHAN SALES CORPORATION. Aug. 16, 1966 [Sept. 1, 1965], No. 36595/66. Heading B3C. [Also in Division B5] A cutting head assembly of the type adapted to be rotatably driven about its longitudinal axis comprises a cutting head 11 having a body portion 23 open at the lower end on which are a plurality of teeth 27, and a disc 57 movable mounted in the body with its outer peripheral edge being substantially equal in diameter to the inner diameter of the body portion, means 49 in the cutting head maintaining the disc perpendicular to the longitudinal axis of the assembly, and a spring 69 in the body portion for urging the disc downwardly towards the lower edge of the body portion. The disc acts to retain the body section 23 circular when the assembly is used for cutting bores at an angle to the surface of a workpiece W. The assembly includes a shank 17 which is adapted for engagement by the chuck 15 of an electric drill 13 and is formed with a circular flange 21 having a pin-and-slot releasable connection with the body section 23. A portion 47 of the shank extends within the body sections and has a screw-threaded bore 53 receiving an extension portion 49, the lower end of which may be formed as a bit 55 for forming a bore B in the workpiece. The disc 57 is formed with a hub 65 and is slidable on the portion 49 with its outer periphery 61 in close proximity to the body section. The teeth 27 are set alternately inward 271 and outward 27<SP>11</SP> the inward teeth acting as a stop against which the disc is pressed by the spring. |
