US1395823A - Tool for scraping cylindrical surfaces - Google Patents

Description

.R. D. HEACOX.

TOOL FOR SCRAPING CYLINDRICAL SURFACES.

Patented Nov. 1, 1921 .H m a an 4w I M W 1 WWII/M22 1 ma a D. fl'eac 0.3!. 05 5 1 N VEN TOR.

A TTORNEY6 R. D. HEACOX.

TOOL FOR SCRAPING CYLINDRICAL SURFACES.

APPLICATION FlL'ED MAR. 16, 1921.

1,395,823. Patented Nov. 1,- 1921.

- 2 SHEETS-SHEET 2.

INVENTOR.

WW gaw duw A TTORNEY-S NHTED STATES,

PATENT OFFICE.

TOOL FOR SCRAPING GYLINDRIGAL SURFACES.

Application filed March 16, 1921.

To all whom it may concern:

Be it known that I, Ross 1). HnAoox, a citizen of the United States, residing at Washington, in the Districtof Columbia, have invented certain new and useful I'mprovements in Tools for. Scraping Cylindrical Surfaces; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to metal working tools and more particularly to a scraper for use in repairing engine cylinders.

The object of the present invention is to provide an improved scraper by means of which the interior of an engine cylinder or metal insert placed in the interior surface of an engine cylinder may be scraped to the correct contour of the cylinder.

A further object of the present invention is to provide a tool adapted to be adjusted to the exact contour of the engine cylinder to be repaired.

The invention consists in the novel method and construction, arrangement and combination of parts as hereinafter more particularly described and claimed.

Two sheets of drawings accompany this specification as part thereof, in which like reference characters indicate similar parts throughout.

Figure l is a side elevation of the preferred form of the present invention;

Fig. 2 is an end elevation;

Fig. 3 is a top plan view of the device shown in Fig. 1;

Fig. 4 is a vertical medial section of the same device;

. Fig. 5 is a diagrammatic view illustrating the adjustability of the scraper;

Fig. 6 is a side elevation of a second modified form of the present invention;

Fig. 7 is an end view of the device shown in Fig. 6;

Fig. 8 is a side elevation partly in section of a third modification, and

Fig. 9 illustrates diagrammatically the operation of the type of device illustrated in Figs. 6 and 7 The cylinders of explosive engines are very apt to become scored in operation by broken wrist pins, broken rings or by reason ofwrist pins working loose and out against the sides of the cylinder. Such scores may be satisfactorily repaired by cleaning out Specification of Letters Patent.

- Patented Nov. 1, 1921.

Serial No. 452,868.

and properly preparing such scores and then filling the scores with a suitable hard solder as is fully described in my copending application, Serial Number453,502. It is then necessary that the solder thus inserted be scraped off to conform with the true cy1indrical surface of the cylinder. Cylinders in use become worn so that the radius of the bore gradually increases with use and it is hence particularly desirable that an adjustable scraper be available which can be made to exactly conform to the bore of the particular cylinder which is to be repaired. An adjustable scraper of the character indicated will obviously have a general application beyond the specific purpose above indicated.

The present invention involves the principle that what may be termed the effective radius of an arc increases proportionately as the plane of the arc is inclined from the perpendicular relative to the axis of a cylindrical surface. To illustrate concretely a flat scraper having an arcuate scraping edge struck on a radius of one inch will, when held perpendicular relative to a plane surface and drawn repeatedly across the same, scrape a cylindrical groove having a radius of one inch. If this same scraper is inclined from the perpendicular relatively to the said surface to be scraped the groove scraped will have a greater radius, proportional to the inclination of the scraper from the perpendicular, which will increase until the scraper lies perfectly parallel with the plane surface in which position no groove at all would be scraped.

Furthermore an adjustment of efiective curvature occurs where a flat scraper having an arcuate cutting edge is bent or shaped cylindrically about an axis parallel with the radius of curvature that bisects said arcuate cutting edge, the effect of which operation is to incline the plane of the arcuate cutting edge relative to said axis.

Applying the principles above indicated applicant employs a scraper 11 of relatively thin sheet steel which is preferably provided with oppositely disposed arcuate cutting edges 12. This may be held between a base plate 6 and a follower member 7 secured together by a nut 8 as illustrated in Fig. 8, base plate 6 being angularly adjustable relative to a tool handle 13 by any suitable means, illustrated here as by having base plate 6 provided with an ear 14 adapted to be pivotally supported as at 15 to a hinge member 16 carried by tool handle 13 and provided with locking bolts 17. In this,the simplest type of device herein illustrated, the scraper 11 is tilted relative to tool handle 13 which will be held by the operator at the most convenient angle relative to the plane of the surface being scraped which with a skilled mechanic may be regarded as substantially a constant.

In Figs. 6 and 7, the scraper 11 is shown secured in a holder adapted to bend it circularlyon an axis extending parallel with the cutter blade and parallel with the chords of the arcuate cutting edges.

Figs. 1 to 4. illustrate a similar scraper 11 in a holder adapted to bend it circularly on an axisextending parallel with the cutter v blade'and perpendicular to the chords of the arcuate cutting edges.

An improved holding device adapted to adj ustably bend the cutter as desired is illustrated herein as comprising the shank 1 having a threaded stud 2 adapted to be received into a mating socket in tool handle 13 and further threaded as at 5 to receive base plate 6. Base plate 6 is preferably provided with parallel flattened sides 9 and rounded ends 18. A projection 3 extends from stud 1 through plate 6 and through a central orific-e of a follower member 7 having rounded ends 18 and depending ears 10 u on its sides adapted to overhang and guide the follower on plate 6. The end of projection 3 which extends abovefollower 7 is threaded to receive an adjustment nut 8 by means of which the follower 7 may be adjusted to or away from base plate 6. The adjacent faces of base plate 6 and follower? are struck to substantially coaxial cylindrical surfaces extending parallel with a straight line bisecting the axes of the cutting-edges as in Figs. 1 to 4: or parallel with the chords of the axes of the cutting edge as illustrated in Figs. 5 and 8.

By tightening or loosening nut 8 the curvature of the scraper member may be increased or reduced as desired and as previously pointed out the radius of the are which the cutting edges 12 will cut will be modified in proportion with this change in the curvature of the scraper. A similar result will be secured by means of tilting the scraper with the device illustrated in Fig. 8.

It will be noted, however, that where the scraper is tilted or where it is bent on an axis extending transversely of the scraper as in Figs. 5 and 6, the angle of the bevel of the cutting edge will be varied relatively to the surface to be scraped which is not always desirable. By bending the scraper on an axis extending longitudinally thereof as illustrated in Figs. 1 to 4, a similar mains constant.

modification of the radius of the groove scraped is secured while in addition the angle of the bevel of the cutting edge re- Experiments further indicate that with the scraper thus bent, a particularly efficient cutting action is secured decidedly superior to that obtained with a fiatscraper, clean cut shavings commencing adjacent the ends of the arcuate cutting edges and curling inwardly toward the center leaving the scraped surface in a highly polished condition. 7

To insure scraping only the alloy inlay and not the original cylinder wall, it is desirable that scrapers intended for this work be made of a steel sufficiently hard to cut the alloy inlay and not the cast'iron of the cylinder.

Having thus fully tion, I claim: Y

1. In a tool for scraping cylindrical surfaces, a holder, a scraper blade having an arcuate cutting edge and means for bending said scraper blade to vary the effective are of the cutting edge with respect to the general plane of the blade in the holder and the holder.

2. A tool for scraping cylindrical surfaces comprising a base plate, a follower member, the facing surfaces of said plate and follower being struck to substantially coaxial cylindrical surfaces, a scraper member adapted to be interposed between the said cylindrical surfaces and means for described my inv'en drawing said base plate and follower tofaces comprising a base plate, a follower,

the facing surfaces of said plate and follower being struck to co-axial cylindrical surfaces, a scraper interposed'between the plate and follower and having an arcuate cutting edge extending beyond the same and means for drawing the plate and follower together to bend the scraper cylindrically therebetween. j

i. In a tool for scraping cylindrical surfaces, a base plate having a convex cylindrical surface, a:follower having a concave cylindrical surface, a fiat scraper member adapted to be received between said surfaces, said scraper having an arcuate cutting edge so disposed relatively to said cylindrical surfaces that the chordiof said arcuate cutting edge is perpendicular to the ROSS D. HEAOOX.

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