US 1831813 A
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Filed July 2, 1928 is ing so as to center the bit -to and enable the spotting hole'to bedrilled Patented Nov. 17., 1931 AXEL Lll'illillAHI,l 0F AURORA., ILLINOIS, TOOL COMPANY, OF CHICAGO, ILLINOIS,
ASSIGNOR T INDEPENDENT PNEUMATIC vun:Mmmm: ron DmLLs Application led July 2,
rlhis invention relates to a device for use with portable power driven drilling tools, such as pneumatic and' electric drills, for drilling spotting 3 n for pieces of hardware and other fixtures.
The invention contemplates an attachment which when applied to a drill will automati- Y cally center thedrill bit with respect to the screw-receiving opening in the fixture-whe m 'fastened in place and limit theidepth to which the spotting hole may loe drilled by the blt.-
' s [a lurther object ol the invention 1s to pro-` vide'the attachment with a guide which enters and lis within the screw-receivingqopeni with respectthereexactly in the center et said opening, so that the screw-head when brought into the same will he concentric and not eccentric therewith #so to'spoil 'the appearance ot the worl'r.
l liurther object of the invention is toprovide the attachment with telescopic parts and a stop therefor by spotting hole will be limited on one of the ae parts coming into contact with the stop.
'lhe invention consists Jnrther in the matters hereinafter described and claimed.
lln the accompanying drawings- Fig. 'l shows an electric the attachment of my invention; and Fie. the attachment to show its details of construction. f
The portable power driven drilling tool inv Fig. 1 is in the form of an electric drill, having secured together motor and gear case sections 1, 2 and a chuck 3 at the outer end oi the gear case section and supporting a drill hit Il, as in tools of this general character. The attachment of my invention comprises a collar 6' which is clamped about the forwardly extending tubular portion 5 of the gear case section 2 and which portion 5 is turned up concentric with the spindle of the tool. The collar 6 is slotted on one side and is drawn tightly about the portion 5 by means of a clamp provided on the collar at one side thereof, and a post 8 has a pressed lit in said boss. The
holes for fastening screws .the spring engages the which the depth'ot the' drill provided with 2 is a vertical sectional'view throughy screw. An apertured boss 7 is.
1928. Serial No. 289,691.
post 8 has the length desired and extends forward from the boss in substantially parallel relation to the coinciding axes of the spindle and bit 4 of the tool. 4
A. member 9, which may be in'the form of a sleeve,v has a sliding liti'on the posty 8 and is provided-on one or bothsides with an elongated slot 10, through-'which extends 'a pin or screw 11 carried by Ithe post 8 to limit the sliding movement of. thefsleeve on L the post. The uppernrinner en'lfoi' loneor both of the slots 10' ishclosed .soasjto limit the outward movement ofl the islefe'vel) on the posta-nd thus prevent thesle'evefrom sliding or dropping ott o the post.' f
, A coil spring 12 is located in the sleeve 9 and entends into a chamber or recessglfwhich is provided in the outer end portion o the -post 8, as-shown inligv. Theinner end of cess and the outer endV of the spring bears against the closed outer end of the Ito normally torce the sleeve outward on the post., as shown in Fig. 2. Che outer end of the sleeve 9 is provided with a recess le to receive f the adjacent end of the spring l2 so as the latter central. l I
An arin 15 is provided at the outer end of the sleeve' 9, and said arm extends over the center of the drill spindle. A tubular guide lis provided at the outer end of the arm 15 and extends forward therefrom concentric with'the axis' of the drill spindle. i The guide 16 is provided 'with a passage or loore to receive the drill bit 4 and thus permit the latter '85 to enter the work on forcing thedrill toward the. same, as usual in drilling operations. The guide 16 may have screw-threaded connection with the arm 15 for removability, and said threads may be lett-handed ones so that the guide will not 'be turned oil the arm in the right-hand rotation of the bit 4 during a. drilling operation. The guide 16 is provided on one side with a slot 17 which opens into the bore of the guide to allow chips to reely pass out of the guide during a` drilling operation.
The guide 16 is made of a size and .shape to enter and fit within the screw-receiving openings 18 in a piece of hardware or other inner 'end ot said resleeve 9l Ill on the sleeve furth same, as shown in the drawings.
To drill the spotting holes for the screws 21 in the support 20, the piece of hardware 19 t0 be attached to the support is placed thereon in the position it is to be fastened to the support by the screws 21. The operator holding the tool then inserts the guide 16 in one o the countersunk openin s 18, and, with the outer end of the guide tting within said opening, the guide centers the drill bit 4 with respect thereto. Then by pressing the tool against the iixture 19, the drill bit 4. will be forced into the support 2Q with the outer surface of the plate 19, as desired for finished work. The spotting holes for the other screws may be drilled in the sameway, and the screw-heads penings 18 and not eccentric thereto to spoil the finish of the work as heretofore. s the operator presses thetool against the work in drilling the spotting holes, the post 8 and sleeve 9 slide one with respect to the other against the tension of the spring 12, and 9 contacting with the boss 7 er movement of the bit 4. Y 1s stopped, thereby automatically limiting the depth of the spotting holes that may be drilled by the bit.
On withdrawing the bit 4 from the support 20, the spring 12 forces the sleeve 9 outward until it 1s contacting h he inner end of the slot 10, in which parts are normal and are set to center and be drilled.
my invention is simple operation and positive Y By means of the device, spotting holes for the screws may accurately and quickly drilled to the depth Y desired and accurately formed in the center of the screw-receiving openings, without any attention required on the part of the operator except to insert the guide 16 into the openings and press the tool against the work. The centering of the it and tures, such as hinges and latches for the outside of frames and doors for refrigerators, kitchen cabinets and the like; handles, latches and the like on sliding windows with thereto so that driven gauge the next spotting hole to frames of wood in cars, and other attachments in such cars, as corner pieces on seat backs, etc.
"The details of structure shown and demay be variously changed and modiied without departing from the spirit yand scope of my invention.
I claim as -my invention:
1. A11 attachment for portable power driven drilling tools, comprising a collar t0 be clamped about the tool and having a boss at one side thereof, a post carried by said boss, a sleeve having a sliding t on said post, a guide carried by said sleeve at its outer en and adapted to enter and lit within a screw-receiving opening in a piece of hardware or other lixture on applying the tool the spotting ho e for the screw by the bit of the tool central may be drilled said opening, and a spring with respect Ato for normally moving the post, said sleeve contacting to limit the depth of the hole drilled by the blt. l
2. An attachment `for portable power driven drilling tools, comprising a collar to be clamped about the tool and having boss at one side thereof, a post oss, a sleeve slidably mounted on said post having an elongated slot in one side thereof, a pin carried by the post and extending through the slot, a spring in said .sleeve lly moving the sleeve outward on the post, an arm at the outer end of the sleeve and extending toward the bit of the tool, and a guide carried by said arm at the bit and having a passage therethrough for the bit.
3. The combination with a drilling tool having with the boss that may be respect to said opening. means associated with said members for e same against rotation and for limiting the depth of the hole that may be drilled by the bit.
In testimony whereof I atlix my signature. AXEL LEVEDAHL. i
the sleeve outward on passenger and sleeping l