US31492A

US31492A - William stewart

Info

Publication number: US31492A
Authority: US
Publication date: 1861-02-19
Anticipated expiration: 1878-02-19

Description

- w. STEWART.

Grinding Mm.

Patented Feb. 19, 1861.

N, PETERS. mmumgnmn wnhmgmn. psc.

UNITED STATES PATENT OFFIE.

VILLIAM STIMVART, OF PHILADELPHIA, PENNSYLVANIA.

MILL.

Specification of Letters Patent No.

To all whom it may concern:

Be it known that I, IILLIAM STEWART, of Philadelphia., in the county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in Grinding- Mills; and I do hereby declare that the fo] lowing is a full, clear, and exact description of the saine, reference being had to the annexed drawings, making a part of this specification, in which- Figure 1 is a vertical central section of my invention taken in the line fc, Fig. 4. Fig. 2 is a detached external view of the conical grinder.l Fig. 3 is a detached veitical central section of the shell. Fig. 4 is a horizontal section of Fig. 1, taken in the line w, Fig. 1.

Similar letteis of reference indicate corresponding parts in the several figures.

The invention relates to an improvement in that class of grinding mills iii which a castemetal conical grinder is placed within a-shell of corresponding form. The chief difficulty attending the operation of this kind of mill has been the producing of uneven work that is to say, portions of the article being ground, are discharged much coarser than others, and the mill while working rapidly produces ,inferior work. In order to obviate this difficulty diagonal teeth or projections have been used in connectioii with the ordinary corrugations or grinding surfaces, said teeth or projections being designed to arrest the progress of the article being ground through the mill, and thereby insure its reduction to a proper fine state before its discharge. This arrangement has not been generally adopted as it creates as great a difficulty as the one it` was designed to obviate, to wit, the choking or clogging of the mill. This class of mills also have been hitherto liable to heat and soon become worn and unfit for use.

My invention consists in a peculiar construction whereby the above named difficulties are avoided, while the advantages of this class of mills, to wit, rapidity of grinding in connection with economy of construction, are retained.

To enable those skilled in the art to vfully understand and construct my invention I will proceed to describe it.

A represents a vertical shaft on which a frustum of a cone B, is secured, and C, C, C, C, 0, are rings or bands which are placed on B, one over the other, each ring 31,492, dated February 19, 1861.

or band being the frustuin of a cone, and the upper end of each a little smaller in diameter than the base of the one immediately above it, as shown clearly in Figs. l and 2. The rings or bands C, are of cast metal, while the conical body B, on which they are placed is of wood. The rings or bands C, may be secured to their body B, in any proper vay so as to prevent them slipping or turning thereon and the whole number of rings when adjusted on their body B, may be described as being a frustum of a cone with an unequal surface caused by the difference in the diameters of the adjoining surfaces of the rings or bands. By referring to Fig. 4 it will be seen that the body B, on which the rings or bands C, are

placed is grooved longitudinally, and a projection a., on the inner side of each ring or band is vfitted in this groove. This arrangement effectually prevents the turning' of the rings or bands on the body B. The top ring or band C, is also secured to the body B, by screws o. The rings or bands C, are provided at their periphery with teeth or coriugatioiis c, which are inclined from a vertical line in a greater or less degree according to the draft required, and the teeth of the rings or bands gradually decrease in size from the upper to the lowermost ring or band, as shown clearly in Fig. 2.

D represents a conical shell which is of cast metal of suitable thickness and has a series of cast metal rings or bands E, E', E, E", E, secured within it. These rings or bands are of conical form, and when secured one over the other in the shell D, form the frustuin of a hollow cone. The rings or bands E, are each provided with a projection c', at their outer sides, and these projections fit in agroove (l, in the shell D,- see Fig. 4. This arrangement efectually prevents the rings or bands E, from turning within the shell D. The lowermost ring or band E, rests on horizontal pins or projections cZ, attached to the shell D. Tlie'inner surfaces of the rings or bands E, are pro vided with teeth or corrugations c, which, like the teeth c, of the rings or bands C, are inclined from a vertical line in a. degree equal to the draft required. The inner surfaces of the rings or bands E, form a uniform surface throughout; that. is to say, the diameter of the adjoining ends of the rings or bands are equal, as will be seen by referring to Figs. 1 and 3.

The rings or bands C, are placed within the rings or bands E, the shell. D, of the latter being secured permanently in a `vertical position, and the lower edge of each ring or band C, just touches the lower edge of its fellow ring or band E, as shown clearly in Fig. l, the rings or bands C, gradually receding from their fellows E, :troni their lower to their upper ends. By this arrangement it will be seen that each ring or band C, with its fellow E, forms a distinct grinding device, and as the shaft A, and rings or bands C, rotate, the article to be ground passes consecutively through a series of grinding devices which are toothed to act in the most eilicient way on the article at different stages of the grinding process, and cause the same to be ground in a uniform manner. p

The superiority of my device over the ordinary conical grinder which is cast in one piece and is brought in contact with the shell only at its base, must be evident, for in this case many portions of the ground article escape in a coarse state. Besides the grinder being also cast in one piece, if it break or crack, an entire new casting is required, and the same may also be said of the shell which is cast in one piece. In my invention any of the rings or bands in case of breaking may be readily replaced by a new one. Y

I would remark that the rings or bands C, are provided at intervals with teeth or clearers a, which extend outward nearly to the teeth of the rings or bands EA These prominent teeth are for the purpose of preventing the choking or clogging of the mill a result which is effected in consequence of the clearers or teeth ai, stirring the mass in the spaces between the upper parts of the rings or bands.

Having thus described my invention what I claim as new and desire to secure by Letters Patent, is

The construction of the grinder with a series of conical toothed rings or concaves E, placed one above the other within an eXterior conical case D, and a series of conical grinding toot-hed rings C placed one above the other upon a cone B, the whole arranged and operating in the manner and for the purposes herein shown and described.

WILLIAM STEW'ART.

lVitnesses:

WILLIAM A. PALMER, JAMES MoCAI-IEN.