US1692977A - Broach with adjustable broaching members - Google Patents

Description

Now 27, 1.928. I

, W. DE VOE ET AL.

BROAOH WITH ADJUSTABLE BROACHING MEMBERS Filed May 23, 1927 72 4? z 55-: MHZ am: H

V62 (Ewe: J: 115/0 Fatente d Nov. 2?, i928.

s ren STATES I mew PATENT orrics.

WILLIAM DE VOE, OE WORCESTER, MASSACHIJ'SETTS, AND JAMES J. WABD, OF DE- TROIT, MICHIGAN, ASSIGNOBS TO DETROIT BROAGH CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

BROAGH WITH ADJUSTABLE BBOACHING MEMBERS.

Application filed May 28, 1927. Serial No. 193,467.

This invention relates to a broach duch as is used for accurately finishing holes to a desired form and size. Such tools are widely used to finish center holes in cams, gears,

a collars or sleeves, for providin spiral keyses. In the general use of a broach of this na ture the cutting elements partake of a substantially longitudinal movement, although ways, and for many other -si ar purpo do in the useof cutting a spiral key-way there will, ofcourse, be a slight rotary movement accompanying the longitudinal movement, that is to say, the general cutting action of the broach is substantially longitudinal, but

115 contains a small proportion of rotational movement. I It is the general object of our inventlon to provide a breach with a plurality of separate broaching members which may beeasily adjusted radially. With this construction, a

worn broach may be restored to size by setting the broaching members outward and then grinding their eripl ieral surfacesagain to size, instead of y face grinding the cutting 2 faces of the broach, as is necessary with the usual one-piece breach.

A further object of our, invention is to provide an improved construction for securing the breaching members to the supporting radially, as and-when desired.

Our invention further'relates to certain arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims. Y

A preferred form of the invention and cer-' tain modifications thereof are shown in the drawings in which Fig. 1 is a side elevationof one form of our improved breach;

Fig. 2 is a side elevation of a portion of the supporting shaft;

igs. 3 and-4 are transverse sectional elevvatipns taken along the lines 3'-3 and 4'-4: .in i 1; v p

Fig? 5. is a side view of one of theb'roaching members;

Fig. 6 is an end .view thereof;

Figs. 7, 8 and 9 are side views of breaching members for cutting different shaped bodysor shaft of the broach, and for simultaneously adjusting said members axially and overlap at their ends, as shown in Fig. 10 is a detail sectional side elevation, illustrating a modification; and

-Fig. 11 is a partial sectional end e1eva tion, showing a further modification.

Referring to the drawings, our improved broach comprises a supporting shaft 20 having an end portion 21 adapted to fit into a breach holder or chuck and having a transverse opening 22 through which a key or stud may be inserted to hold the breach in the holder. Both end portions of the shaft 20 are preferably threaded to receive adjusting nuts 24 and lock nuts 25. u The middle portion of the supporting shaft 20 is provided with a plurality'of flat bearing surfaces 26, spaced about the axis of the breach as indicated in Figs. 3 and 4, and each provided with an undercut or dovetailed guideway or recess 27. The bearingsurfaces 26 are inclined with. respect to the axis of the broach, the angle shown in the drawings being substantially 10. This angle is illustrative only and may be increased or decreased in accordance with the work to be performed.

The surfaces 26 are preferably arranged in groups, each of which, as shown in Figs. U 3 and 4, comprises three surfaces 26 symmetrically arranged about the axis of the breach. The bearing surfaces of one group preferably overlap the bearin surfaces of the next group, and are positioned axially and angularly substantially midway between the bearing surfaces of the next successiv group; i

A broaching member 30 is mounted on each bearingsurface 26 and is provided with an over hanging or dove-tailed projection 31, fitting the guideway or recess 27. The broach as illustrated in Figs. 1 to 6 is depreferably forms a segment of a cone with the extreme edge portion 33 substantially cylindrical.

' The side faces 34 and 35 of the breaching members are disposed at such an angle to their inner faces 36 that they will be perpendicular to the axis-of the breach. when inworking position. The breaching members 30 are of such circumferential width that the breach members of successive lgroups 105 and 4, thus broaching the complete inner surface of the hole to be finished.

In the operation of our improved broach,-

I the broaching members 30 are mounted in thedove-tailed recesses 27, and spacing collars are interposed between successive groups of broaching members. Collars or sleeves 41 of greater length may be used at the ends of the broach to fill up the space not occupied by the broaching members. The collars 41 are engaged by the adjusting nuts 24, which are used to clamp the collars and broaching members firmly together, after which the broaching members may be ground on their outer peripheral surfaces to the desired size of the finished hole.

After a large number of broaching operations have been performed, so that the sharp edges of the broaching members have become du l or worn, the broaching members are adjusted toward the right, as viewed in Fig. 1, by loosening'the right hand nut 24 and i advancing the left hand nut 24. This will produce axialmovement of all of the broaching members, with a corresponding outward or radial movement of said members. When the broaching members have thus been slight- 1y expanded, the broaching members may be again ground on their peripheral faces to restore the size and sharp cutting edges of the broachin members. a

It will e noted that the only grinding operation is plain cylindrical grinding and that no face grindin is necessary, as was the case in the old style roaches. This operation of expanding and regrinding will be repeated as often as is necessary, until the broaching members have been moved to the extreme outer ends of the bearing surfaces 26, whenthey may be removed and replaced by new members at relatively small expense. One or more pilot collars 42 may be used at the entering end-of the broach if desired.

While we have indicated the broaching members, as arranged in alternate groups of three members each, it' will be understood that any other desired number of broaching members may be used, and that they may be .variously grouped. It is evident also that our broach may be modified by forming the dove-tailed projections 45 (Fig. 11) on the bearing surfaces 46 and by forming the dove tailed recesses 47 in the broaching members 48. f

While we. have shown and. described a broach for finishing circular holes, we have indicated in Figs. 7, 8 and 9 that the broach members 50 may be fvariously shaped, to

broach hexagonal or octagonal holes, or holes y members slmultaneouslyaxially on said surhaving any other 'desired cross section. In a broach of the type designed for cutting keyways, it will be appreciated that the crosssection of the broach member will be suitably shaped. I

While the general cutting movement of the broach is lon 'tudinal with respect to the work-piece it Is evident that a small proportion of rotational movement may be intro duced if desired or necessary. 1

In Fig. 10, we have illustrated a further modification in which the broaching members have their side faces 61 and 62 formed perpendicular to the bearing surfaces 63, instead of perpendicular to the axis of the broach. The spacing collars 64 used with such broaching members Will be provided with bevelled ends corresponding to the inclination of the surfaces 61 and 62 with respect to the axis of the broach. This form of broaching member provides a natural rake for the cutting face, without the necessity of under cutting the side faces of the broaching me-mbers, and is very desirable in many cases. K

Having described our invention and the 4 method of using the same, the advantages thereof will be readily apparent. The broaching members may be expanded outwardly and reg'round to size a great number stantially reducing the users investment.

compared'with that of maintaining a stock of the old-style, solid broaches.

Having thus described our invention and the advantages thereof, we do not wish to be limited to t-he details herein di closed, otherwise than as set forth in the cla1 s, but what we do claim is:

1. An adjustable broach for finishing internal work by relative movement longitudinall thereof, comprising a supporting shaft having a plurality of bearing surfaces spaced apart, both axially and circumferentially, and inclined outwardly with respect'to the broach axis, and a separate broaching member seated on each bearing surface and firmly retained in position thereon, said broaching members being adjustable axially of said broach to vary the radial position of their outer circumferentialsurfaces.

.2. An adjustable broach for finishing internal work by relative movement longitudinally thereof, comprising a supporting shaft having a plurality of bearing surfaces spaced apart, both axially and circumferentially, and inclined outwardly with respect to the broach axis, a plurality of broaching members slidably mounted on said bearing suraces, and means to move said broaching thereof, comprising a supporting shaft having a plurality of bearing surfaces arranged substantially on the periphery thereof and spaced apart, both axially and circumferentially, and? inclined outwardly with respect 5 to the breach axis, a plurality of breaching membersslidably mounted on said bearing surfaces, said breaching members bein located in successive parallel planes along t e axis of said breach, and means to secure said breaching members on said bearing surfaces.

4:. An adjustable breach for finishing internal work-by relative movement longitudinally thereof, comprising a supporting shaft having a plurality of bearing surfaces arranged substantially on the periphery thereof and spaced apart, both axially and circumferentially, and inclined outwardly with respect to the breach axis, a plurality of breaching members slidably mounted on said bearin surfaces, said breathing members being located in successive parallel planes along the axis of said breach and the breaching members in one plane having their ends circumferentially overlapping the ends of the 'b'ri'oachingj members in each next adjacent p ane.

5,. An adjustable breach for finishing internal work by relative movement longitudinally thereof, comprising a supporting shaft having a plurality efbearing surfaces spaced apart, both axially and circumferentially, and inclined outwardly with respect to the breach axis, a plurality of'broaching members slidably mounted on said bearing surfaces and arranged in circumferential groups, spacing collars separating said groups of breaching members, and means to move all of said collars and members axially to adjust tube radial positions of said breaching memers, 4

6. An adjustable breach forfinishing internal work by relative movement longitudinally thereof, comprising a supporting shaft having a plurality of bearing surfaces are ranged substantially on the periphery thereof and spaced apart, both axially and circumferentially, and inclined outwardly with respect to the breach axis, a plurality of breaching members slidably mounted on said bearso ing surfaces, spacing collars separating said breaching members, and lock nuts threaded on said supporting shaft and effective to move said collars and said breaching members axially on said shaft to adjust the radial position of said breaching members,

7. An adjustable breach for finishing internal. work by relative movement longitudinally thereof, comprising a supporting shaft having a plurality of bearing surfaces arranged substantially on the periphery thereof and spaced apart, both axially and circumferentially, and inclined outwardly with respect to the breach axis, a plurality, of breaching members slidably mounted on said bearing surfaces, each of one set of parts having an undercut axially-extended guiding recess and each of the other set of parts having a corresponding overhanging pro ection fitting therein.

8. An adjustable breach for finishing internal work by relative movement longitudinallythereof, comprising a supporting shaft having a plurality of bearing surfaces arranged substantially on the peripherv thereof and spaced apart, both axially and circumferentially, and inclined outwardly with respect to the breach axis, a plurality of breaching members slidably mounted on said bearing surfaces, said shaft having undercut axiallyextended guiding recesses formed in said bearing surfaces, and said breaching members having dove-tailed projections fitting said recesses.

9. An adjustable breach for finishing internal work by relative movement longitudinally thereof, comprising a supporting shaft having a plurality of bearing surfaces, arranged substantially on the periphery thereof and each inclined outwardly from the axis of the breach, said surfaces being arranged ee in axial rows angularly spaced about said shaft, and having-each bearing surface ineach row displacedaxiallywith respect to the bearing surfaces in the adjacent rows, and

breaching members slidably mounted on said bearing surfaces.

10. An adjustable breach for finishing internal work by relative movement longitudinally thereof, comprising a supporting shaft having a plurality of bearing surfaces, arranged substantially en. the periphery thereof and each equally inclined outwardly from the axis of the breach, said surfaces being arranged in parallel axial rows equally spaced angularly about said shaft, and having each bearing surface in each row displaced axially with respect to the bearing surfaces in J the adjacent rows by substantially half the length of a bearing surface, and breaching members slidably mounted'en said bearing surfac s. v

11. n adjustable breach for finishing internal work by relative movement longitudinally thereof, comprising a supporting shaft having 'a plurality of bearing surfaces arranged substantially en the periphery thereof and each equally inclined outwardly from the axis of the breach, said surfaces being arranged in parallel axial rows angularly spaced "about said shaft, and having each bearing surface in each row displaced axially with respect to the bearing surfaces in the adjacent rows, breaching members slidably mounted on said bearing surfaces, and ar ranged in circumferential groups, and means to secure the breaching members in each group to said supporting shaft with their cutting edges in a single plane.

12. An adjustable breach for finishing internal work by relative movement longitudi nall thereof, comprising a supporting shaft having a plurality of bearing surfaces, each equally inclined outwardly from the axis of the broach, said surfaces being arranged in parallel axial rows equally spaced angularly about said shaft, certain of said bearing surfaces bein displaced axially with respect to the other ear1ng surfaces, broaching members slidably mounted on said bearing surfaces, certain of said broaching members be- .ing displaced axially with respect to the other broaching members, means to prevent outward displacement of said broaching members, and means to move said members simultaneously axially along said broach, thereby also moving said members radially outward.

13. An adjustable broach for finishing internal work by relative movement longitudinally thereof, comprising a shaft, having a plurality of bearing surfaces arranged substantially at the periphery thereof and spaced apart, both axially and. circumferentially, a plurality of broaching members each slidably mounted on one of said surfaces, said broaching members being located in successive planes along the axis of the breach, the members in one plane having their ends circumferentially overlapping the ends of the broaching members in each next adjacent plane.

14. An adjustable broach for finishing internal work by relative movement longitudinally thereof, comprisin a shaft, having a plurality of bearin sur aces arranged sub.- stantially at the periphery thereof and spaced apart, both axially and circumferentially, a plurality of broaching members each slldably mounted on one of said surfaces, said broaching members being located in successive planes along the axis of the broach, the members in one plane having their ends axially overlapping the ends of the broaching members in each next adjacent plane.

15. An adjustable broach for finishing internal work by relative movement longitudinally thereof, comprising a shaft, having a plurality of bearing surfaces arranged substantially at the periphery thereof and spaced apart, both axially and circumferentially, a plurality of broaching members each slidably mounted on one of said surfaces, said broaching members being located in successive planes along the axis of the broach, the members in one plane having their ends circumferentially and axially overlapping the ends of the broaching members in each next adjacent plane.

In testimony whereof we have hereunto aflixed our signatures.

WILLIAM DE VOE.

JAMES J. WARD.

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