US2038782A - Abrasive element and method of making same - Google Patents

Description

w. J. ELLIS 2,038,782 ABRASIVE ELEMENT AND METHOD OF MAKING SAME April 28, 1936.

Original Filed May 16, 1951 U m/ 1 :T OJ u .i. 1 1 8 :1 i 7 in INVENTOR.

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A TTORNEYS Patented Apr. 28, 1 93 6 ABRASIVE LELEMENT MAKING AND METHOD OF SAME William'J. Ellis, Los Angeles, Calif., assignor to Hazel J. Ellis, Los Angeles, Calif.

Application May 16,1931, Serial No. 537,792 Renewed November 7, 1935 9 Claims.

which has been wrapped a strip of abrasive-cov-' ered fabric. It has now been discovered that the mandrel and the abrasive surface may be formed in'a single operation with consequent increased production and reduced costs. These abrasive elements are used in surfacing articles of metal and wood, castings, etc;, such articles often having curved surfaces which it is desired to treat with the abrasive. A revolving cylindrical tube or sleeve does not fit into these curved surfaces very well and it is also desired to provide an abrasive element which shall conform to the surface being treated.

It is accordingly an object of the invention to provide a method of making tubular abrasive elements in an improved and economical manner. Another object of the invention is to provide a 43 method for manufacturing these. elements in'a strong and durable form and in a single process. A further object of the invention is to provide an abrasive element of sturdy construction molded to conform to curved surfaces which are to be treated and which will retain its shape under the stresses encountered during use. To the. accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawing:

Fig. 1 is a diagrammatic view showing the method of forming abrasive elements; Fig. 2 is a perspective of a tubular element built up by the new method with the various layers exposed;

Fig. 3 is a perspective of a complete element with mandrel and abrasive layers in place; Fig. 4 is a view showing one modification of a molded tubular element; Fig. 5 is a view of another modification; Fig. 6 is a view of a tubular element having molded ends.

Referring to Fig. 1, a series of rolls 1, 8, 9 and III are mounted on a shaft I I. These rolls, which may vary in number from that shown, carry strips of fabric l2, l3, l4 and I5 suitable to be built up into a tubular abrasive element, for example, strips l 2 and l 3 may consist of chipboard or kraft paper suitable to form a mandrel, while strip I! may be of kraft paper to form an inner or supporting 5 sleeve and strip I5 will consist of paper with an abrasive coating to form the outer surface of the abrasive element. I do not desire to be limited to the materials named, it being understood that cloth may be used as well as various kinds of 10 paper for any of the layers mentioned provided the outer layer bears an abrasive coating.

The various strips are fed from the rolls onto a mandrel I6 and are spiraled thereon, the mandrel strips I2 and [3 being wrapped first to form 15 a permanent mandrel for the abrasive element and the strip l5 being wrapped last to form the abrasive surface. Adhesive is supplied to the various stripsin order that they will adhere in a strong and permanent fashion. The element is 2o pushed off the mandrel l6 as fast as it is formed, the process'thus being continuous in character. The various strips may overlap each other in order to stagger the seams and thus increase the strength of the finished article. If a cylindrical 25 abrasive element is desired, the tube may be cut off in suitable lengths as it is formed.

A section of the abrasive element so formed is shown in Fig. 2 in which the element I l is shown as consisting of a mandrel in two layers l8 and 30 I9, although this may be formed in one layer or in many layers if desired by omitting one of the rolls I and. 8 or increasing the number'of such rolls. Over the mandrel may be placed the inner or supporting sleeve 2| although this also 35 may be omitted. The outermost layer 22 bears the surface of abrasive particles which is to be used in surfacing operations. Fig. 3 shows a finished cylindrical abrasive element 29 with mandrel, sleeve and abrasive layers. 0

As above mentioned, it is often desired to treat articles having curved surfaces and it is highly desirable to provide a surfacing element which will conform to the surface of the work being treated. Fig. 4 shows a surfacing element 24 45 having a convex surface 25 adapted to treat con- .cave surfaces where encountered, while Fig. 5

shows a surfacing element 26 having a concave surface 21 adapted to treat convex surfaces where encountered. 50

The desired contour is imparted to the cylindrical element formed in the above method either immediately after the formation of the cylinder while the adhesive is still soft and the element still moldable or, the element may be moistened 55 .or placed in a steam box, and then molded.

' shapes thus imparted to the abrasive elements will be surfaces of revolution since the element is,

The

to be applied while rotating to the curved surfaces of the work under treatment. It will be obvious that any desired contour may be im- I of the seam will not be encountered by the work.

4 cal thereto.

parted, those shown on the drawing being merely illustrative.

While the tubular element is being molded, I have found it desirable also to mold the ends of the section in order to bend these slightly inward toward the axis of the tube although, of course,

desired, only the ends need be molded, this being a special case where a-cylindrical element is under the general method. My purpose in thus molding or turning in the ends of the-cylinder is to avoid tearing or ripping the abrasive element which often encounters sharp corners when applied, while rotating, to the. work, the edge or corner encountered being likely to catch the seam 28. If the ends are bent inward as at 29, the end By building up the entire element, including the .mandrel and abrasive surface, in one operation,

the molding step may .be carried out on the newly formed tube while it is still plastic, before any of the adhesive necessary to form the tube has set.

The present method of making an abrasive sleeve or element by forming the mandrel simultaneously with the abrasive surface results in increased speed of production and lower cost while the abrasive elements having surfaces molded to conform to the work being treated are much more eflicient and cut down the cost of surfacing articles treated thereby. v

Other modes, of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means' stated by any of the following claims or the equivalent of such stated means be employed.

1- therefore particularly point out and distinctly claim as my invention:

1. A method of making abrasive elements which comprises forminga mandrel and permanently uniting an abrasive covering thereto in one continuous operation and then molding the same under pressure. I

2. A method of making abrasive elements which comprises winding fabric strips to form a mandrel andimmediat'ely winding an abrasive strip over said mandrel strips in one continuous operation and then subjecting said element to a molding operation under pressure.

3. A method of making abrasive elements which comprises simultaneously winding man-.- drel strips and anabrasivestrip to form a composite abrasive element and then softening said element and molding the same to impart a surface of revolution thereto.

4. A method of making abrasive elements which comprises simultaneously winding mandrel strips and an abrasive strip to form a-composite cylindrical abrasive element and then molding the same, while the adhesive used is soft, to impart a surface of revolution other than cylindri- 5. A method of making tubular abrasive velements which comprises forming a. cylindrical abrasive tube and then. molding the same under pressure.

6. A method of making an abrasive'element which comprises forming a tubular abrasive ele-- ment and then compressing the same to impart a surface ofrevolution thereto.

7. In the method of making an abrasive element the step which comprises molding a tubular

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