US1792546A - Cutting element - Google Patents

Description

Feb. 17, 1931. c w NOBLE 1,792,546

- CUTTING ELEMENT 7 Filed Dec. 2'7, 1927 lNl/ENTOR f/a/zence l4. Nab/a ATTORNEY Patented Feb. 17, 1931 UNITED STATES} PATEN OFFICE CLARENCE W. NOBLE, OF HOOSICK BALLS, NEW YORK, ASSIGNOR TO THE NOBLE AND WOOD .MACH'INE 00., OF HOOSICK FALLS, NEW YORK, A CORPORATION OF NEW YORK CUTTING ELEMENT Application filed. December 27, 1927. SeriaI No. 242,913.

'My invention relates to the so-called cutting elements employed in the various machines used in the process of paper making. It refers particularly to the cutting elements used in beating engines and similar devices such as mixing, breaking, pulping and bleaching engines, and also'to those elements as used in refiningengines and the like.

In a beating engine, for exampleflzhe bed plate comprises a plurality of so called cutting elements which, however, have dull edges and may be steel lates about onequarter inch in thickness. otatively mounted over the bed plate is the beater roll which is provided with a plurality of similar cutting elements arranged about the periphery thereof, and which is supported in vertically adjustable bearings so that the distance between the cutting elements in the beater roll and those in the bed platemay be varied.

The roll is turned from a suitable source of power and the fibers in the material being or drawn out by repeated passage between theroll and plate. I

These cutting elements are constantly subjected not only to the corrosive action of water but also to that of the various chem- I icals used in the process. Furthermore, be-

cause the machines run constantly in one direction, the elements become worn on one side so that the edges, instead of remaining dull and square, become rounded and comparatively sharp. In this condition they are more readily susceptible to erosion and corrosion and soon become so serrated and uneven that replacement is necessary. Moreover, particles of metal are carried into the stock and cause spots in the finished paper.

. Entirely aside from the fact that the present type of element is susceptible to corrosion and rapid disintegration, the particular way in which it wears soon renders it extremely ineflicient if not entirely unfit for use in the manufacture of the better grades of paper. VJ hat is desired, is a cutting element which 1 will hold a substantially square, dull edge'so that it will brush, comb or draw 'out the fibers rather than cut them.

to provide a cuttting element which will be 7 substantially non-corrosive, which will be highly resistant to erosion, and yet, will possess the desired ductility and resilience. to

prevent breakage Another object is to provide an element which will wear slowly in such a way as to maintain the cutting edge substantially square and dull. A further object is to provide an element in which the central portion of the cutting edge will wear at a somewhat more rapid rate than the outer portions so that the cutting edge will be slightly concave. I

With these objects in view my invention includes the novel features of the elements described below and illustrated in the accompanying drawings in which-'- Fig. 1 is a fragmentary perspective view of a cutting element; the end thereof being shown in section; V

Fig. 2 is a sectional view of two coacting elements illustrating how the edges thereof become worn with use; and

Fig. 3 is a fragmentary perspective view of the present type of cutting element showing,'in a more or less conventional manner, how the edge thereof becomes worn with use.

The ordinary cutting elements used in paper making machinery may be and are made of various metals or alloys having the necessary hardness,'elasticity, ductility and other physical or chemical characteristics rendering them more or less fit for the purpose intended. 'Ihe elements now in practical use are substantially homogeneous throughout although it has been proposed to weld relatively thick plates of iron to the sides of a steel core and thus form a composite beater bar having a surface offering a higher resistance to corrosion than ordinary steel.

My invention proceeds upon the general principle of constructing these elements of two separate metals of widely difi'erent physicalcharacteristics insofar as hardness and wear resisting qualities are concerned where by the manner in which the composite ele-- ment wears may be controlled. In its preferred form, my invention contemplates the formation of an element from any suitable metal or alloy, and" plating it with another metal or alloy which, in a comparative sense, is extremely hard and .not Susceptible to erosion or corrosion by the ordinary chemicals or agents used in thepaper making industry.

It is well known, for example, that the element chromium is extremely hard, is not afiected by water or the ordinary chemicals used in preparing paper stock, and moreover, may beplated on other metals to form a film having the hardness of a diamond.

This being so, I find that by plating an ordinary cutting element with a-thin film or layer of chromium it is rendered not only noncorrosive and highly resistant to Wear and erosion, but also that the manner in which it wears is entirely different from themanner in which the ordinary homogeneous element wears.

In the drawings, 1 represents a fragmentary portion of the present type of element illustrating how the edge, 2, thereof becomes worn with use. When new, the cutting edge of the element is substantially as shown by the dotted outline, 8, and it is highly desirable, for reasons above mentioned, that the cutting edge be maintained substantially square across and dull rather than curved and sharp.

Referring to Fig. 1, 4 represents generally a fragmentary portion of a cutting element having a surface of chromium plate. The interior portion, 5, may be of any suitable material having'the desired elasticity, ductility and strength, and, 6 represents the chromium.

Referring to Fig. 2, 7 represents, for example, a section of a cutting element on the beater roll while, 8 represents a section of a cutting element in the bed plate of a beater. Although the chromium is. very hard, the thin layer thereof on the cutting edge is soon worn off and, because the main body of the element is of a softer material, such as steel or the like, and the cutting edge is subjected to the greatest wear, this surface becomes slightly concaved as shown at 9. The extreme hardnessof the chromium prevents the element from wearing as shown in Fig. 3 and the cutting edges are maintained substantially square anddull as shown in Fig. 2.

In addition to providing a cutting element which is substantially non-corrosive and which has a useful life many times longer than those of the present type, a machine equipped withthese elements is found to be somewhat more eflicientthan the same machine equipped with elementsof the older type. This is believed to be due to the concavity of the cutting edges.

While I have mentioned only chromium as a suitable plating metal because of its extreme hardness and non-corrosive qualities,

it will be apparent that the beneficial results herein described may be obtained in a lesser degree perhaps by the use of other hard, noncorrosive substances as a coating for the elements. I

It is therefore to be understood that my invention, in its broader aspects, is not limited to chromium alone as a,plating material but that other substances possessing the essential physical characteristics of chromium as above described, may be used.

What I claim is 1. Acutting element of the character described adapted for use in paper making engines and having a dull, slightly, concave cutting surface; the extreme edges of said surface being of chromium, and the portion intermediate the edges being of a relatively softer and faster wearing metal.

2. A cutting element of the character described adapted for use in paper making engines and having the central portion of the cutting edge and the side portions thereof composed respectively of different metals; the metal of the side portions being very much harder than the metal of the central portion.

3. In a paper making machine, a cutting element of the character described,comprising a blade-like metal bar having a dull cutting edge protected on one side by a plating of chromium.

4. In a paper making machine, a cutting element of the character described characterized by side surface portions adjacent the cutting edge of a much greater degree of hardness than the cutting edge itself.

5. In a paper making machine, a cutting element comprising a substantially integral bar having the extreme side portions thereof of a much greater degree of hardness than the interior portions.

6. In a paper making machine, a cutting element of the character described characterized bya side surface portion adjacent the cutting edge of a much greater degree of hardness than the cutting edge itself.

CLARENCE W. NOBLE.

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