US2944447A - Hole chamfering tool - Google Patents

Description

July 12, 1960 H. w. EBERHARDT HOLE CHAMF'ERING, TOOL Filed Dec. 1. 1958 VIII/III! INVENTOR HERMAN w. LBERHARDT Hli ATTORNEY .1 Home Term .Herman"WJ"EberharilhlFitirlawnfNl, as'signor. toCurtiss-Wright 'Gorporaition, -a" corporation of Delaware :Filed Bee; 1, 1958;Ser. No.7775291 Claims. or; 772 3.5;

-My -invention*r'elateszto a holech'amfering tobl and- 'is particularly directed tome'ans'forchamfe'ring a'hole with a hidden j e'dgei'? 'Whenboth sidesof a' workpiece are accessible,:holes through the part are easily chamfered with conventional,

chamfering tools. -If,4however,..one.side of,rthe workpiece is"'inacces'ible,as 'for example,""in closed or sub-, stantially closed shapes, aspecialtool "is required to .chamferathe .hidden edge.of .the :hole, that? ion the inaccessible .side .of .the:=piece. wl'speciali .Itools .em- :ployed heretofore. .for this..purpose shave not:I-been. too

satisfactory either in operation or in results obtained.

theeiedge One of the diflicultiesencounterediirtchamfering a hid- -xlen edge.rof' a; h ole;is thatgthe -operation-zcannot be observed and in consequence the depth of cut is not readily controlled.

The prime object of this invention is to provide a generally improved tool forchamfering the hidden edge" of a hole and to provide for a controlled depth of cut I on a hidden edge with such a tool.

Other objects and advantages of the invention will become apparent hereinafter.

The invention is explained in detailin the ensuing description, which should be read in conjunction with the annexed drawing in which similar reference char acters designate similar parts and in which: I

" Fig. 1 is a top plan view, and Fig. 2 is an elevational view, partially in section, showing the tool of the invention;

Figs. 3 and 4 are top and elevational views respectively of a cylindrical member constituting the tool body;

Figs. 5 and 6 are elevational views of portions of the tool movable within the cylindrical member of Figs. 3 and 4;

Fig. 7 is a top plan view of a wedge used in conjunction with the tool of the invention; 7

Fig. 8 is a side elevational view of the wedge of Fig. 7; I

Fig. 9 is an enlarged elevational view illustrating the cutting portion of the tool.

Referring to the drawings, reference character 1 designates the tool of the invention. Such tool includes a cylindrical body member 2 which houses a two-part member 3. The two-part member 3 comprises an upper cylindrical portion 4, having a sliding fit with member 2, and a lower cylindrical portion 5 of lesser diameter than the portion 4. A spring 6 within the member 2 abuts at opposite ends against member 2 and portion 4 of the member 3. The purpose of the spring 6 in carrying out the function of the tool will be explained hereinafter.

As shown, portion 4 of the two-part member 3 is tapped at 7 to receive a screw 8. The body member 2 is provided with an L-shaped slot 9, and the screw 8 registers a the hole.

2,944,447, p tent d July 12, 19

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7 :2 '7 slot"'9. Whenthetool' is' being rea'diedfor use. or'for .withdrawall-from a holeupon completion of, a chamfer- 'ing operatiomthe screw 8 -is positioned in the horizontal portion 11 ofthe slot'9 and. caused to lock in placein "the end'12' of slot portion 11. Thescrew is positioned bydepressing the-knob 13 formed on the upper end of portion 4 of the two-partmember 3 to compress'the spring'6. With the screw at the lower end of'the vertical ,portionltl of the slot'9 the knob 13 is turned slightly in] acounterclockwise direction to lock the screw in smaller'diametefthan portion 4. .The portion 5 carries a hook-shaped working part of the tool 14 at its lower end. 'fTlie two parts,'4 and. 5, .are separable, being joined by a screw connection at 15. If, replacement of the working part becomes necessary due .to.darnage or if a different 3 working part is required for any other reason the; lower portion 5 .of two-part member 3 may be separated from 3 upper portion '4. and withdrawn 'from the housing .2, through ope'ning15' at the lowerendofthe housingand .;the .part.5 replaced. Portion 4 of 'thetwo-part member remains Jwithin Ithe cylindrical. member. 2. A

. 'As. stated,-.' the tool'jis readied foruseqby. lockingthe -screw. 8'. in portiorL'lZ of the slot 9,1thereby. disposing the ...two;part Qmember. and..the, .cutting. portion 14. of. the .tool intheir' lowest positions relative to the member 2. When the screw has been so located, the working part 14 of the tool protrudes a considerable distance below the extreme end of member 2 and can be inserted through a hole for chamfering the hidden edge. Because of the configuration of the working part 14, such part must be manipulated into the hole by first inserting the extreme end offpart 14.,into the hole with the axis of the tool at an acute angle to the surface of the workpiece, and then moving the tool into a vertical position to complete the insertion.

, After insertion of the cutting portion of the tool into a hole as 16 (Fig. 9) a wedge 17 is inserted between the lower end 18 of cylindrical member 2 and the-workpiece 19, the wedge being recessed at 17' to fit about portion 5 of two-part member 3. The knob 13 of the member 3 is then slightly depressed and turned to release the member 3 from its locked condition. The spring 6 becomes effective to urge the member 3 upwardly in cylindrical member 2 and force the cutting edge 20 of the tool against the edge 21 of the hole. The spring 6 urges the lower end 18 of cylindrical member 2 against the upper surface of the wedge. The knob 13 of the tool is then turned so as to rotate the tool and cause the cutting edge 20 to chamfer the edge 21 of Knob 13 is preferably knurled as at 13 to facilitate the turning of the tool with the fingers. Preferably the diameter of the working portion 14 of the tool is only slightly less than the diameter of the hole. The cutting portion 14 of the tool is formed with an abutment shown as a flat surface at 22. This surface of the workpiece and prevents further cutting of the metal. The cutting portion 14 of the tool may be designed with an abutting surface 22 to provide any depth of cut and different parts may be substituted for portion 5 as required to obtain a different depth of'c'ut, the

with and protrudes into this slot in the assembled tool. When the tool is in use theiscrew 8 is disposed in some 22 in relation to cutting edge 2 p v V 1 intermediate position in the vertical portion 10 of the After the edge 21 of the hole has been chamfered,

depth of cut being determined by the position of surface 'knob 13 is depressed and turned to lock the screw 8 in The wedge'17 is then Withdrawn tion of the device is, for example, extremely simple and the parts are easily assembled. Also the working portion of the tool is easily removed and replaced when necessary. In addition, a controlled depth of cut. is provided for even though the actual cutting during a chamfering operation is not directly observable by one using the tool.

While only one form of the invention has been shown 7 in the drawings and described in the specification, it will be obvious to those skilled in the art that various changes and modifications may be made in structure without departing from the spirit and scope of the invention as set out in the appended claims.

I claim: 1. A hole chamfering device'comprising a tool portion with a cutting edge for 'chamfering the inside edge of v the hole of a workpiece, a pair of members one of which urging the cutting edge against the inside edge of the hole and the said other member against said support, and means for turning the tool portion to accomplish the chamfering of the hole.

2. The combination as defined in claim 1 including locking means for holding the said one member in a fixed position against the biasing force of the spring means.

3. A hole chamfering device comprising a tool portion with a cutting edge for chamfering the inside edge of the hole of a workpiece, a pair of'members one of which is attached to said tool portion and is axially movable relative to the other member, a support for the other member having a substantially -U-shaped end portion insertable between the other said member and the workpiece and being substantially wedge shaped in a plane perpendicular to the plane of the U-shaped portion,

.spring means which bears against said members urging the cutting edge against the inside edge of the hole and the said other member against said support, and means for turning the tool portion to accomplish the chamfering is attached to said tool portion and is axially movable, relative to the other member, a support for the said other member having a substantially U-shaped portion insertable between the said other member and the workpiece, spring means which bears against said members of the. hole.

References Cited in the file ofthis patent UNITED STATES PATENTS 308,842 Hunt Dec. 2, 1884 2,188,624 Dantry et a1. Jan. 30, 1940 2,365,648 Rossmann Dec. 19, '1944 FOREIGN PATENTS 7 658,867 Great Britain Oct. 17, 1951

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