JPS63116592U

JPS63116592U -

Info

Publication number: JPS63116592U
Application number: JP969687U
Authority: JP
Priority date: 1987-01-26
Filing date: 1987-01-26
Publication date: 1988-07-27

Description

[Brief explanation of the drawing]

第１図ないし第３図は、この考案の一実施例を
示す図であり、第１図は、ロツクビツトの側面図
、第２図は、同平面図、第３図は、ロツクビツト
の要部の断面図、第４図および第５図は、この考
案の他の実施例を示す図であり、第４図は、ロツ
クビツトの側面図、第５図は、同平面図、第６図
は、穿孔時のビツト径φＤの減少量を示す図、第
７図ないし第９図は従来のロツクビツトの一例を
示す図であり、第７図は、ロツクビツトの側面図
、第８図は、同平面図、第９図はロツクビツトの
要部の断面図である。１……ビツト本体、１ａ……頭部、１０，１６
……チツプ（刃体）、１１，１７……円弧面。 Figures 1 to 3 are views showing one embodiment of the invention, with Figure 1 being a side view of the lock bit, Figure 2 being a plan view of the lock bit, and Figure 3 showing the main parts of the lock bit. A cross-sectional view, FIGS. 4 and 5 show other embodiments of the invention. FIG. 4 is a side view of the lock bit, FIG. 5 is a plan view of the lock bit, and FIG. FIGS. 7 to 9 are diagrams showing an example of a conventional lock bit. FIG. 7 is a side view of the lock bit, and FIG. 8 is a plan view thereof. FIG. 9 is a sectional view of the main parts of the lock bit. 1... Bit body, 1a... Head, 10, 16
...Chip (blade body), 11, 17...Circular surface.

Claims

[Claim for Utility Model Registration] A plurality of blades are implanted on the top end surface of the head of the bit body, and among these blades, the blade located at the outermost periphery of the top end surface is the one described above. In a lock bit that is implanted so as to be inclined away from the axis of the bit body as it goes from the rear end side to the front end side of the bit body, the blade body is implanted at the outermost periphery of the head tip surface. A lock bit characterized in that the surface facing the outer circumferential side of the bit body is an arcuate surface having a radius of curvature that is approximately the same as the outer circumferential surface of the head with the axis of rotation of the bit body as the center.