US2113836A - Polishing apparatus - Google Patents

Description

April 12, i938 A. E. HAM-5N 2,113,836

POLISHING APPARATUS OriginaINFiled April @1955 INVENTOR Patented Apr. 12, 1938 UNITED STATES POLISHING APPARATUS Alfred E. Hamilton, Pittsburgh, Pa.

Application April 6, 1935, Serial No. 15,067 Renewed December 8, 1936 3 Claims.

My invention relates to polishing apparatus and .more particularly to those of thetype customarily classified with bufling' wheels and grinding wheels. The invention is particularly suitable for the polishing of various articles such as knife blades, axes,metallic articles generally, and particularly those having irregular curves and thicknesses.

Heretofore it has been common practice to employ polishing rolls-or wheels builtup of felt or other fabric, and having some yieldability, but suchpolishing rolls become hardened in time and have to be frequently renewed at great ex-- pense. Furthermore, they are not sufliciently yieldable to permit of uniform polishing of articles which are not of uniform thickness, as for example, in the case of most knife blades, axes, and the like.

One object of my invention is to provide a bufilng wheel or roll of such form that it can be rendered sufllciently yieldable to avoid excessive polishing or grinding on the thicker areas of articles which are of non-uniformthickness, and which on the other hand, willexert suflicient polishing pressure against the thinner sections of the articles being operated upon.

Another object of my invention is to provide a polishing roll or wheel of such form that the degree of yieldability thereof can be readily changed at the will of the operator.

Still another object of my invention is to provide a polishing and bufllng tool of such form that worn abrasive carrying elements can be quickly replaced at small expense.

35 Some of the forms which my invention may take are shown in the accompanying drawing wherein Figure 1 is a longitudinal sectional view through a. pair of polishing rolls; Fig. 2 is a view taken on the line III-11 of Fig. 1; Fig. 3

40 shows a modification of one of the polishing rolls of Fig. 1; Fig. 4 shows still another modification;

Fig. 5 is an edge view of an abrasive-carrying sleeve for one of the polishing wheels, andFig. 6

is a face view thereof.

Referring first to Figs. 1 and 2, I show roll stands 8 that support a pair of polishing rolls 9. The rolls 9 are mounted on shafts In which are driven from any suitable source of power, and at desired rates of speed.

The rolls 9 may be or identical construction, and therefore only one of them is shown in section. The body portions of the rolls may conveniently be of yieldable material such as reinforced rubber or rubberized fabric, and are rigidly secured to the shafts III in any suitable manner. As shown in the drawing, the rolls are composed mainly of rubber, reinforced by fabric that is. imbedded therein, the hub portions 9a of the rolls being stretched onto the shaft, or may be held thereon by pressureapplied interiorly of 5 the rolls.

An abrasive covering II is provided for each roll, which cover may be in the form of a sleeve 'made of walrus skin, canvas or other fabric,

or of any flexible material to which an abrasive 10 such as emery may be applied. The sleeves can be placed on the rolls by contracting the rolls slightly, and then permitting them to expand.

The rolls have'intemal annular ribs 12 formed integrally therewith, and of increasing thickness 15 toward the middle of the rolls at which point there is, of course, greater tendency toward radial displacement, either through centrifugal forces or through pressure applied against the periphery of the rolls. A valve I3 is provided in an end of each of the rolls through which valve air under pressure may be introduced. The degree of pressure provided within the rolls 9 will be dependent, of course, upon the extent to which it is desired that the rolls shall resist pressuresagainst their peripheries.

It will be understood that the articles to be polished are moved into the roll pass and then withdrawn, or passed'entirely through the rolls, depending upon the nature of the articles being ground and polished. In the case of knife blades, for example, wherein the thickness may vary greatly, the pressure within the rolls 9 may be maintained fairly high, especially if considerable polishing pressure is desired. 0n the other hand, where the article operated upon varies greatly in thickness, the air pressures within the "rolls will'be reduced somewhat so there will not be excessive polishing pressures on the thicker portions of the articles, and so that the thinner 40 portions of the articles will be adequately engaged by the rolls.

The ribs I! serve not only to stiifen the rolls somewhat against inward deflection, especially when air pressures within the rolls are low, but

they resist excessive displacement under centrii ugal forces when the rolls are rotated rapidly.

For some classes of work, the air within 'the rolls' may be at atmospheric pressures, and there may be' cases where it'is desirable to create subatmospheric pressures-within the rolls, in which instances, the rolls can be rotated so rapidly that they will distort radially under centrifugal force, and therefore exert a lighter polishing pressure than where there is super-atmospheric pressure within the rolls. In either event, however, the polishing pressure within certain limits can be controlled by regulating the speed of rotation of the rolls.

Referring now to Fig. 3, I show a polishing wheel l4 which may be of reinforced rubber, and which is provided with an internal circumferentiallyextending rib l5 which yieldably resists radial displacement of the peripheral wall of the wheel, as in the case of the ribs II. In this instance, an

abrasive-carrying sleeve 16 can he slipped into place on the wheel, whenever desired, and a valve I I is provided for the introduction of a desired quantity of air to-the interior of the wheel to render the same more or less yieldable, as may be desired. The periphery of the wheel I4 is concave in directions axially of the wheel, to accommodate articles whose surfaces are curved. The rolls of Fig. 1, of course, are capable of properly polishing curved articles which are not too sharply curved, but the wheel of Fig. 4 will more accurately polish articles curved on extremely short and varying radii.

In Fig. 4, I show a polishing wheel l8 that is of the same general form as the wheel H, but which has two annular ribs IS in its side walls, instead of a peripheral stifiening rib. The ribs l9 will permit of greater radial movement or depression of the peripheral wall of the wheel at its central line,

but will resist displacement of the side walls of the wheel.

The wheels l4 and I8 as in the case of the rolls 9 at their ends or peripheral corners, are of greater diameter than at points intermediate their ends,

tions will prevent the sleeves from shifting axially on the wheels when in use.

The wheels of Figs. 3 and 4 can be used singly,-

and can also be mo nted in side-by-side groupings upon shafts suc as the shafts l0.

It will be understood that the polishing rolls and wheels are capable of being used for general grinding, bufling, and polishing operations, and with various kinds of grinding and polishing materials. Also, that abrasive material could be directly imbedded in the peripheral surfaces of the rolls or wheels, and that the polishing tools need not necessarily be in the form of wheels or rolls.

The terms wheels, "rolls and drums are employed in a broad sense, since it is obvious that a roll is in efiect a wheel that is of relatively great dimension in an axial direction.

I claim as my invention:-

1. A polishing device of drum-like form closed at its ends, and provided with. annular ribs axially spacedon its inner peripheral wall, all of said elements being of yieldable material.

2. A polishing device of drum-like form closed at its ends, and provided with annular ribs on its inner peripheral wall, all of said elements being of yieldable material, and those ribs near the mid portion of the drum being of greater thickness than the other ribs.

3. A polishing device of drum-like form closed at its ends, and provided with annular ribs axially spaced on its inner peripheral wall, all of said elements being of yieldable material, and means for maintaining air at a desired pressure within the device.

ALFRED E. HAMILTON.

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