US1460427A - Expanding fly cutter - Google Patents

Description

July 3, 1923.. 1,460,427 :J. P. MILLS v I EXPANDING FLY CUTTER Fil ed Feb, 24. 1920 INVENTOR.

JAMES P. MILLS.

A TTORNEY.

Patented July 3, 1923.

UNITED sr T's-s1- PATE QEE CE JAMES P. MILLS, or nnfrrtorr, MIGI-IIGEAN, ASSIGNOR' To-oouTINEN'rAL-Morons-con ron a'rrou; or nnrajorr, MICHIGAN, AoonroaATIou or VIRGINIA; I

- EXPANDING FLY CUTTER.

I v..A plication filed February 2 192:9. Serialjll'o. 360962.

ToaZZ whomit may concern; f; j -'Be it known that I, JAMEslVlrLns, a citizenof, the-United Statesj res ding at Detroit, inthecounty of lVayne and-sea 5 of Michigan have invented a new' and useful Improvement in Expanding ters, of .which the following s a specificati'on. v

. My invention relates'to an in rprovedform of expanding fly cutter for use where a shell cutter must be employed asdistinguls'hed from a solid cutter, and it is a further feature of my invention to provide such adevice with improved means of accurately grinding the fly cutter to a desired cutting radius. 1 I 1 My improved construction is particularly applicable for use in connection Wltllltl1 finishingof' bearings or seats for bearings 20 where a central boreis finished by the same operation that outside bores of lesser diameter are finished by means of the same boring bar.

My invention will best be understood by showing a preferred embodiment thereof in which- I Fig. 1 shows the device in longitudmal sectional view, 1 i

Fig. 2 is an end view of the parts shown in Fig. 1,

Fig. 3 is a plan view of one of the cutters employed, and V I I Fig. 4: shows the cutter in side elevation.

Similar numerals refer to similar parts throughout the several views.

As shown inFig. 1 my device consists of a sleeve 10 having on opposite sidesthereof, inclined grooves 11 and 12 for receiving the bars 13 and 14 respectively, said bars hav ing inclined inner faces corresponding with the lnclination of the bottoms of thegrooves.

The ends of the bars 13 and 14 are beveled to be engaged by internally threaded collars 15 and 16 which engage corresponding threads formed on the ends of the shell 10.

The collars 15 and 16 are held in any desired adjustment by the locking collars 17" and 18 respectively which. are internally threaded and fit on the threads on the ends of the shell 10. One of the bars-13 and 14 has a cutter 19 or 20 projecting outwardly from it. this cutterbeing preferably inclined somewhat to the axis of the shell 10 as'indicated for the cutter 19 in Figs. 3 and 4.

' reference to the accompanying drawings Pins 21 project inwardly-from theshelfll l toengage a driying' baron which thejs'hell'" may be mountedjw-hen the'cutter is' intuse.

Inf preparing'm'yj improved I euttencdn struction for 7 use; the shell 510" is mounted on the arbor-of a 1 grinding machine, theahre ded collars are adjusted so thatthe "cutter19 and the projection 20'b0th project" slightly v beyond required s s ad u idr the jection 20' are ground, by; g qmtio Ofthe arbor Carrying the ll 10 until the diam- 7 ter oyer the cutter "19 and 'the projection 20 is exactly thedesi'red cutting diameter 'for. I

'70 certain operations which are contemplated the present inventiom any cutter must be emp'loyed to give good. results' as", distin- 1 guished from a cutterihaving a pluralityof; cutting edges and to produce" this eoa'strue the tool. As is well knownlin' the 1' art; .for

tion, after the, tool has been ground as described, the projection 20, has an additional amount ground from its edge which is just I sufficient to clear the depth of cut f the cutter. This it will be readily seen does not disturb the cutting radius of the cutter, and the dev ce may be placed" on a boring bar and used with the certainty that the bored hole willhave the desired diameter. When it 1s necessary to sharpen the cutter sthe threaded collars are released and moved I along the sleeve 10 so that the bars. 13 and 14 are moved outwardly enough'togpermit their outeredges to be ground off to bring. the cutter and the projectionagain togthe desired radius.

It will be understood'that the boring bar supporting the cutter forming'the subject;

matter of this invention, particularly. where I the boring bar is used as above referred to, to bore a plurality of bearings or seats for bearings by the same operation andby the same boring bar, is preferably supported at I both ends to prevent vibration and insure s mo accurate work. In the event o-f'bo'ring several bearings or seats for bearings by the same operation; particularly where the bear-. 5

ings or seats for bearings are of different diameter, as for example the crank shaft bearings in the, crank case of aninternal combustion motor; a separate cutteriis used for'each bearing :or bearing seatj'Yt-he con- '1 struction of boring bar preferably permitting ready engagement of the borlng bar,

by the pins 21 of the cutter and ready re movability of the-cutter from the boring bar.

From the above it will be understood that by myinvention ready means are provided for accurately grinding a fly cutter of the type described to size, and furthermore that by my construction all of the parts may be used repeatedly by moving a tubular cutter has its cutting portion formed integrally with its shell.

While I have shown my invention in the particular embodiment above described, I :do nothowever limit myself to this exact construction in carrying out my invention, asI may employ equivalents thereof known to the art at the time of the filing of this application without departing from the scope of the appended claims.

What I claim is:

1. A fly cutter comprising a cylindrical shell, a pair of longitudinally extending bars adj ustably secured at diametrically o-p- .posite sides of said shell, a cutting blade carried by and extending radially'from one of said bars, and a gauging projection carried by and extending radially from the other of said bars, said gauging projection, when the cutter is ready for use, being reduced to slightly less radius than said cutting blade, whereby said projection clears the finished portion of the bore.

The hereindescribed method of accurately gauging the cutting radius of a rotary cutter having but asingle cutting blade projec'ting from its periphery, which comprises providing a radial projection on said cutter at a point diametrically opposite said blade, grinding the ends of said blade and projection to an equal radius and until their overall diameter is equal to that of the bore desired, and then further grinding off the end of said projection until its radius is slightly less than that of the blade, whereby, in operation, when the cutter is mounted on a rigid arbor, the projection does not engage the Work.

In witness whereof, I hereunto subscribe my name this 2nd day of February, A. D. 1920. 1

JAMES P. MILLS.

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