US1776280A - Bit lock - Google Patents

Description

'Sept 23, 1930' J. M. BOYD 1,776,280

BIT LOCK Filed Nov. 19..'1927 In en or Jam f7. 305/09 Allorney Patented Sept. 23, 1930 UNITED STATES :roi-:N M. BOYD7 or SEATTLE, WASHINGTON BIT LOCK Application filed November 19, 1927. Serial No. 234,341.71;` y

end of the drilling tool and prevent the bit from becoming loosened, thereby preventing loss of the bit. v

In carrying out my invention, l provide ra locking bolt that is adapted to lock the bit to the drill rod after the former has been screwed to the latter, and means jare pro'- vided whereby the retaining` bolt may with facility be withdrawn in order that the bit may be unscrewed from the rod when deired.

The invention consists in certain novel combinations and arrangements of parts as will hereinafter be more fully pointed out and claimed.

ln the accompanying drawings, l have illustrated one complete example of the physical embodiment of my invention wherein the parts are combined and arranged according to the best Inode I have so far devised for the practical application of the principles of my invention.

Figure 1 is a view in elevation at the lower end of an earth boring or drilling tool showing the use of the device of my invention;

Fig. 2 is an enlarged detail vertical sectional view at line 22 of Fig. 1 showing the bit locked on the lower end of the drill rod;

Fig. 8 is a View similar to Fig. 2V but with the locking bolt withdrawn and the bit re- 1eased so that it may be nnscrewed;

4 is an enlarged detail view as at line 4--4 of Fig. 2;

Fig. 5 is a perspective view of the spring pressed locking bolt; and

Fig. 6 is an enlarged perspective view of the lever for the bolt.

In order that the general'arrangement and relation of parts may readily be understood, l have shown in Fig. 1 a well known type PTNT "oFF- ics Ofbit as 1 :having a vshank 2 vwhich isyse- A cured tothe rod or tool 3. The shank is provided with the usual tapered threaded head 4 andthisis screwed into 'the complementary socket head 5 Onthelower endof ythe tool. Thefprimary Object of`1ny-invention is to prevent the lthreaded head 4 from becoming `imscrewed from thesocket head, and to this end l employ a spring pressed b olt16 located at. one side j, of the longitudinal center of the-tool` and .normallycarriedin theV sockethead. n. y i Y.

y AThe bit shank ,-2 is lfashioned withpseveral sockets indicated as'"7 in Fig. 4, and one of these sockets is adapted to receive the bolt 6 as indicated. The bolt is carried in a recess 8 in the socket head 5 and a spring 9 in this Vrecess bears against thespring bolt 6 and tends to force it from its socket 8 into the socket 7 in the bit shank. In locked position as in Fig. 2, the spring retains the bolt in the socket 7 and the bit is thus prevented from turning with relation to the socket head 5.

To withdraw the bolt from its socket 7 I provide a lever 10 which normally lies in a i groove 11 in the exterior face of the socket head 5, and this lever coacts with the spring l bolt 6 which is provided with a longitudinal slot 12. The spring bolt is equipped with a pin 13 that extends transversely through the l bolt and through the slot 12, and the lever 10 is` provided with a curved arm 14 of proper width to iit within the slot 12. arm 14 lits around the pin 13 and the shoulders 15 of the lever at the sides of the arm 14 prevent -excess movement ofthe lever. As shown in Fig. 2, the lever 10 lies in the groove 11 and its angular arm'14 engages the pin 13. r1`he angular arm 14 projects through a transverse slot 16 in the socket head and the bent portion of the lever 10Y bears against the bottom wall of this slot 16 as the fulcrum whenthe lever is turned to-withdraw the bolt 6. In F ig. 3, it will be seen that the lever has been swung outwardly to withdraw the bolt, in order that the bitmay be unscrewed from the socket head. As soon as the lever 10 is released, the spring 9 bearing against the spring bolt quickly moves the This curved bolt and swings the lever 10 into itsgroove 11 in order to hold the lever in position.

The lever 10 may be turned by slipping the thumb-nail or a sharp edge tool under the free end of the lever to give it the initial movement and then it may be swung by hand to rele-ase the spring bolt. After release, the lever lO'is automatically returned to its groove l1 by action of the spring 9. e

Having thus fully described my invention,

what I claim as new and desire to seeure'by Letters Patent is The combination with a bit having a boltY socket and a threaded head, oa complementary nteriorly threaded socket head receiving the threaded heaehsaid socket head havfing an exterior groove and transverse slot,

' a spring-pressed bolt in said socket head eooperating with the bolt socket and provided i with a longitudinal slot, a transverse pin in vthe bolt-slot, an L-sha-ped lever having a curved end looselyengaging said pin and adapted to lie'in the' groove, and lateral stop shoulders en the lever adapted to engage the bolt, whereby said lever co-operates with the bottom wall of the-transverse slot to acta-s a fulerum when the lever is turned,

VIn testimony whereo vaffix my signa-ture.

JOHN M. Born.

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