US2823498A - Honing element - Google Patents

Description

Feb. 18, 1958 a. A. SAUNDERS 2,823,498

HONING ELEMENT 2 Sheets-Sheet l a fi Linden J Filed April 5. 1956 Feb. 18, 1958 G. A. SAUNDERS 2,823,498

HONING ELEMENT 2 Sheets-Sheet 2 Filed April 5. 1956 5% l 7 2 b WC w v 5/ s H 2 I m 5 O 9 a O wk 1. 2 2% m w z m m a 9 Z z 2 MVETIQTQM e tj uvnciem/f Gear W2 Maw HONING ELEMENT George A. Saunders, Rockford, Ill., assignor to Barnes Drill Co., Rockford, Ill., a corporation of Illinois Application April 5, 1956, Serial No. 576,402 3 Claims. (Cl. 51-204 This invention relates to a honing element comprising an abrasive stick and a holder therefor adapted to fit closely in the slot of a rotary body for radial shifting by. an expanding cam. The invention has more particular reference to the manner of frictionally holding the honing element in its slot. v

The general object is to provide between the honing element and the associated cam follower a novel disengageable connection which permits of low cost manufacture of the element, a wide range of adjustment and long wear of the abrasive stick, ready replacement of the element when worn, and solid backing of the stick during service use.

A more detailed object is to frictionally hold the cam follower plate in the hone body and interlock with the plate the projecting ends of a simple holder secured to the bottom of thestick. H v

The invention also resides in the novel construction of the interlocking joint which permits sidewise shifting of g the honing elementrelative to the follower plate and into solid abutment with the trailing side wall of the body slot.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which Figure 1 is a fragmentary longitudinal sectional view of a honing tool having abrasive elements embodying the novel features of the present invention.

Figs. 2 and 3 are fragmentary sections taken respectively along the lines 2-2 and 3-3 of Fig. 1.

Fig. 4 is an exploded perspective view of the improved honing element and its support.

Fig. 5 is a fragmentary view of part of Fig. 1 showing another position of the cam follower by which the honing element is expanded.

Fig. 6 is a section taken along the line 6-6 of Fig. 5.

Fig. 7 is a perspective view of a modified form of the honing element.

Fig. 8 is a perspective view of the modified abrasive stick holder.

Referring first to the form shown in Figs. 1 to 4, the improved honing element is especially adapted for use in a rotary honing tool having elongated parallel sided slots 10 angularly spaced around the tool body 11 and each adapted to receive a composite replaceable honing element 12 comprising an abrasive stick 13 and a holder 14 therefor. The stick is an elongated block of bonded abrasive covered on at least one side and in this instance on both sides with a thin strip 15 of resinous plastic material which is adapted to wear down with the working face 16 in service use. In this instance, the strips 15 extend from the working face all the way down to the bottom of the stone. The combined width of the stone and the strips is only slightly less than the width of the slots 10.

The honing elements 12 are adapted to be expanded radially by the usual conical cams 17 spaced along a 2 push rod 18 slidable axially of the body 11. The cam surfaces bear against complemental surfaces on the narrowed inner edges of projections 19 spaced along the inner edge of elongated follower plates 20 adapted to fit closely within the slots 10 both laterally and longitudinally. Preferably and for a purpose to appear later, the

outer flat faces 21 of the plates 20 are disposed slightly beyond the outer periphery of the body 10 when the push rod 18 is in its limit position shown in Fig. 5 of maximum expansion of the follower plates.

In accordance with one aspect of the invention, the

different radial positions of the follower plates 20 are maintained frictionally. This may be accomplished for example by plugs 22 of firm resiliently yieldable material such as rubber pressed into transverse holes 23 in the plates 20 and having a free length slightly greater than the Width of the plates so that at least one end 24 (see Fig. 4) projects a short distance, for example, of an inch, beyond the side of the plate before insertion thereof in a slot 10. By pressing the plug ends inwardly, the bar with the plugs thereon may be inserted edgewise between the side walls of the slot, the follower projections 19 thus becoming seated against the earns 17. With the plug thus compressed and abutting against the slot walls, enough friction will be created to hold the plates .securely within the slots under the centrifugal forces encountered in the service use of the tool. T he friction de- 19. In this location, the plug ends remain in engagement with the slot walls in all ofthe degrees of expansion 4 of the plates.

The invention contemplates the provision of a novel means for connecting the honing element 12 detachably to oneof the plates 20 so that the friction on theplates is also utilized to 'hold the elements in the slots while at the same time permitting lateral shifting of the element relative to its supporting plate into firm abutting contact with the trailing wall of the slot as shown in Fig. 3. This connecting means includes the holder 14 which, in the form shown in Figs. 1 to 4, comprises a relatively thin and flat bar 25 of metal corresponding in width approximately to the stick 13 and its side coverings 15 but longer than the stick so that the ends 26 of the bar extend beyond opposite ends of the stick. These ends, when the bar is lying against the outer surface 21 of the follower plate 20, project into squared notches .27 formed in lugs 28 upstanding from the ends of the bar and having ends 29 turned inwardly and toward each other so as to overlie the bar ends 26 and hold the honing element against the follower bar. the bar 25 so that by shifting the honing element laterally with the ends 26 in register with the notches, these ends will interlock with the lugs 28 as the honing element is brought into the plane of the plate 20 as shown in Fig. 3.

The lugs 28 may perform the additional function of holding the honing element against endwise shifting during its reciprocation while engaging the work. For this purpose, the ends 29 of the lugs may project close to the ends of the abrasive stick or, as in this instance, be positioned for engagement with short lugs 30 struck out of the holder ends 26 and upstanding at the ends of the stick in abutment with the latter.

To remove a worn out set of honing elements in a hone constructed as above described, the push rod 18 and the cams thereon are shifted to the limit position shown in Fig. 5 thus fully expanding the follower plates 20 so as to expose their outer edges 21 above the periphery of the body 11. The worn out honing elements may then he slid sidewise out of the notches 27 and thus separated from the plates as shown in Fig. 6. New honing elements are then inserted and brought into edgewise alinement one Patented Feb. 18, 8

The notches 27 are open at the sides of corresponding plates 20, each element, after retraction of the expanding cams, may be pushed down into the slots until the working faces 16 are spaced only a short distance outwardly beyond the periphery of the body. The tool is then ready for service use, the folslower plates 20 being held frictionally in the slots by the plugs 22 and the honing elements being held by virtue of the interlocking of the bar ends 26 and the lugs 28. At the same time, each element is free to shift sidewise along the top 21 of its plate 20 and thus come solidly against the trailing side wall-of the slot under the circumferentially directed friction force applied to the working face 16 of the element when this face first comes into contact with a work surface with the hone rotating. Thus, each honing element-s, although received loosely in its slot, is shifted automatically to working position without the necessity of disturbing the accurately guided follower plates.

By making the bar wider than the bottom of the 7 stick 13 as shown in Fig. 3 andextending the side strips 15 clear to the stick bottom, the expanding pressure exerted by the cams is transmitted through the bar directly to the strips rather than through the adhesive securing the strips to the stick. The possibility of the strips being dislodged in service use is thus avoided.

If desired, the nonmetallic coverings 15 at the sides of the stick 13 and the holder 14 including the bar 25 for supporting the latter and for interlocking with the lugs 28 may be formed as one unitary piece and take the form of a channel as shown in Figs. 7 and 8. The lugs of the construction shown in Fig. 4 are omitted and the lug ends 29 are extended for abutment with the ends of the abrasive stick.

I claim as my invention:

1. For use in a hone having a rotary body and an elongated slot therein, the combination of, an elongated member adapted to fit loosely in said slot, a resiliently yieldable member projecting from said member and frictionally engageable under compression with a wall of said slot to hold the member in the slot during rotation of said body, lugs at opposite ends of said member upstanding from the outer facethereof and turned inwardly to form opposed notches open'in at least one direction laterally of the member, a stickof bonded abrasive lying along said face and disposed between said lugs, and a holder underlying -the.bottom of said stick and rigidly secured to the latter, said "holder having ends projecting beyond opposite ends of the stick and adapted to enter said notches by bodily edgewise movement of the holder.

2. For use in a hone having a camfollower plate with outstanding lugs near opposite ends defining opposed notches facing toward each other along the outer edge of the plate, a honing element comprising a stick of bonded abrasive adapted to fitbetweensaid lugs,.a strip of nonmetallic material covering at. least one side of said stick and extending to the bottom thereof, and a flat bar extending along and rigidly secured tothebottom of said stick with one edge underlyingand engaging the lower edge of said strip, the ends of said bar. projecting beyond the ends of said stick and being adapted to. enter said notchesby bodily edgewisemovement of the bar while lying against said plate edge.

3. A homingelement as defined by claim 2 including projections rigid with saidbar and. upstanding from the latter short of the bar ends. and adjacent opposite ends of said stick.

References Cited in the: file of thispatent UNITED STATES PATENTS 1,698,590 Harter Jan. 8,1929 2,106,205; Connor Ian.- 25, 1938 2,201,593 Prange May 21, 1940 2,265,377 Kline Dec. 9, 1941 2,751,726 Klein June 26, 1956

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