US787543A - Rag-engine. - Google Patents

Description

No. 787,543. PATENTED APR. 18, 1905.-

' W. SCHMIDT.

RAG ENGINE.

' APPLICATION FILED FEB. 9, 1901- 2 SHEETS-SHEET 1.

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wad W140i mmwwm UNITED STATES latented April 18, 1905.

W ILHELM SCHMIDT, OF LAMBREOHT, GERMANY.

RAG-ENGINE.

SPECIFICATION forming part of Letters Patent No. 787,543, dated April 18, 1905.

Application filed February 9, 1901. Serial No. 46,607. 7

1'0 all whom it may concern.-

Be it known that I, W'ILHELM SCHMIDT, manufacturer, residin at Kaiserslauterer Staatsstrasse, No. 93, ambrecht, in the Palatinate, Germany, have invented new and useful Improvements in Rag-Engines, (for which I have applied for Letters Patent in Germany, Sch. 16,633. VII 55, dated -December 8, 1900; in France, No. 294,948, dated December 22, 1900; in England, No. 22,963, dated December 15, 1900; in Russia, No. 12,894, dated December 19, 1900; in Denmark, No. 1,357, dated December 12, 1900; in Finland, application dated December 14, 1900; in Norway, No. 13,305, dated December 13, 1900; in Sweden, No. 2,128, dated December 11, 1900, and in Belgium, No. 121,945, dated December 24, 1900,) of which the following is a specification.

My invention relates to the grinding-surfaces of rag-engines in which a rotary drum or roller cooperates with a bed-plate.

The object of my invention 1s to improve such grinding-surfaces or grinding elements so as to render them very strong, durable, and efficient.

The invention will be full described hereinafter and the features of novelty pointed out in the appended claims.

In order to enable anybody skilled in the art to carry out my invention, I have appended drawings showing the same.

Figure 1 shows a roller provided with stone cutters disposed insockets on the roller-body. Fig. 2 shows a roller providedwith a stone ring on its periphery. Fig. 3 shows a bedplate with cutters of stone.

Referring to Fig. 1, a is the roller-body, made, for instance, as hitherto, of cast-iron. b represents,sckets or slots, preferably of somewhat conical shape, disposed at suitable intervals, which sockets are adapted to receive the cutters or knives or groups of cutters c. d is anintermediate layer of wood, cement, or the like between the cast-iron body and the stone cutters, while e is a wedge, of wood, cement, or other suitable material, for clamping the cutters fast in the sockets. The hold in the cutter is further increased by swelling the wood with water and in the case of cement by allowing it to harden. f represents the grooves or recesses, wedge-shaped in form, which form projections, the working edge 9 of which is arranged as far as possible at right angles to the shaft, the opposite ed e 71. being beveled ofi. These grooves there ore when viewed in cross-section have approximately the shape of a triangle the apex of which is rounded. This form of the grooves presents the following advantage over the hitherto employed rectangular U shaped grooves. In the latter only about that half of each groove is filled with material which in the new form is fully filled therewith, the other half in the old form remaining full of air, which is carried round by the material and which then escapes into the material. The use of the new form of the grooves prevents the disadvantageous formation of scum caused by ,the air carried around. Even the sharpened edges of the stone do not act with such shearing effect as the metal knives one against the other, so that the stones thus rub down the material more into its separate fibers and disintegrate it rather than out it transversely. When the working surfaces become blunted, the grooves may be sharpened by their being dressed again.

Referring now to Fig. 2, instead of the several cutters disposed in slots of the roller-body the latteris surrounded on its periphery by a I ring of stone fastened by suitable means. On

- the outer surface of this ring i grooves or recesses f are cut out in the same manner as above described, the letter k denoting the deeper grooves corresponding to the intervals between the several cutters of the arrangement shown in Fig. 1.

Referring to Fig. 3, there is shown a bedplate provided with cutters of stones. Zis the frame or box of the bed-platemade, for instance, of cast-iron. m represents the several cutters of stone, likewise furnished with grooves and fastened in the frame or box by cement, wood, or other suitable material. The stone of the bed-plate is preferably softer than that employed for the roller in order that the wear may preferably take place on bed-plate, which is more easily replaced. Especially in the case of the ring form this would be advantageous. It is also to be noticed that rollers provided with stone cutters may, however, be employed in conjunction with bed-plates or stationary parts of the kind employed hitherto, and, further, the cutters of the bed-plate, may also be made of stone and the rollers made in the manner formerly employed. As is well known, a lar e stone is usually composed of hard and so t parts, so that, for instance, even the French millstones are made up of several small pieces in orderito obtain an even hardness. By this reason the cutters, groups of cutters, or rings may be made of several stones cemented or otherwise firmly connected together. Especially in the case of a ring surrounding the roller-body this ring may consist of a number of rings dis posed edgewise and cemented together. The improved arrangement is not expensive, since the existing roller-bodies and bed-plate frames may be further employed. The stone cutters become worn less than metal knives. Furthermore, the replacement of a knife or cutter which may have become damaged is considerably facilitated, especially in the case of the arrangement according to Fig. 1.

The manufacture of rollers and bed-plates provided with cutters of stone has a considerable advantage for certain kinds of paper such, for instance, as the paper for photo graphic purposes-over the use of metal, as this paper material does not contain iron, copper, and tin, which would entirely prevent the use of the paper for photographic purposes even if the smallest traces of these substances were present. I prefer to employ basaltic lava on account of its being a homogeneously hard and porous stone. The large number of pores provides a rough and efficient grinding-surface, which is not materially smoothed by wear, for the reason that the stone is porous throughout. It must also be noticed that the use of the improved rollers and bed-plates is also suitable for bevel-mills for grinding paper material, the roller and groundwork of which are conical in shape, so as to fit together. The improved arrangement may also be employed for socalled centrifugal rag-engmes, 1n which the rotary grinding-surface, which 1s provlded with grooves, is not placed on the periphery, but on the ends of the rollers.

For the purpose of protecting the metallic parts of the working bodies against acids and for preventing metal or rust from mixing with the paper material all free parts are preferably coated with cement or any suitable material. For this purpose the stones which form the groups of cutters and which are inserted in the roller preferably extend over the ends of the roller, the extension being about a half to one inch. These extensions are coated on a level with the end surfaces with the protecting material. In the case of the ring form of the stone also the rings extend over the end of the roller, and the metallic parts are likewise coated with protecting material. In a similar manner the free edges of the frame or box of the bed-plate may be coated.

What I claim, and desire to secure by Letters Patent, is the following:

1. A grinding element, comprising a frame having a plurality of recesses, a filling forming a lining for each of said recesses, grinding members set in said recesses and embraced by the filling, said members projecting outwardly from the recesses, and wedges interposed between adjacent grinding members at their projectin portions and en aging the end faces of the fi ling and the end face of the frame between adjacent recesses.

2. A grindin element, comprising a frame having a plurality of recesses contracted at their mouths, a filling forming a lining for each of said recesses and made of varying thickness, so that its inner surface incloses a space of uniform width, grinding members set in said recesses and embraced by the filling, the side surfaces of a grinding member, within the recess, being substantially par- 1 allel, while the outwardly-projecting portions of adjoining grinding members have their adjacent faces disposed at an angle to each other, and wedges interposed between said adjacent faces. a

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILHELM SCHMIDT.

Witnesses l\/IICHAEL ZIMMERMANN, HEINRIGH RINDERROCKE.

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