US147733A - Isaac yearsley - Google Patents

Description

l. YEARSLEY, 1r.

M'i'llstnne-Dress for Bone-Nilis.

N0.147,733. PatenxeuFehJLmM..

UNITED STATES PATENT QFFICE.

isAAo rEAnsLnnon., or ooArnsvrLLn, rrsnsrLvArrA.

IMPROVEMENT IN MlLLSTNE-DRESS FR BONENHLLS.

Specification forming part of Letters Patent No. 147,733, dated February 17, 1874; application filed May 21,1873.

To all whom it may concern:

Be it known that I, IsAAc YnAnsLnv, Jr., of Goatesville, Chester county, Pennsylvania, have invented an Improved Dress for Bone- Mills, of which the following is a specification:

The object of my invention is the eiiective trituration of bones by grinding-surfaces which do not become unduly heated, and which can be used for a longer period than ordinary grinding-surfaces without being impaired, a-nd can be easily renewed by reversing the motion of the mill. I attain this object by annular' grinding plates, portions of which are shown in Figures l and 2 of the accompanying drawing, the said plates having a dress consisting of annular rows of quadrangular teeth a a, the t'ull size of which is represented iu the perspective view, Fig.

The two grinding surfaces, Figs. l and 2, bear such relation to each other that the annular rows of teeth ot' the revolving plate A shall traverse the spaces between the annular rows of teeth of the fixed plate A', hence, supposing the view, Fig. 3, to represent a portion of the fixed plate, and the revolving' plate to be moving in the direction of the arrow, the cutting effect on the bones will be produced bythe action of two ot' the four edges ot' each pyramidal tooth of the revolving plate, in conjunction with two edges, w of each p yramidal tooth of the fixed plate. Vhen these cuttingedges of the teeth have become worn and unservicea-ble, the motion of the revolving plate should be reversed, when a new sharp set of cutting-edges are brought into play, hence the importance of making the teeth of quadrangular shape, so as to present four cuttingedges. In order to permit this reversal of the motion of the revolving plate and still retain the triturating effect, it is essential that there should be groups of rows of teeth, the rows being parallel with each other and with a radial line passing through the center of each group. Thus the plate A has a series of groups, m, of five rows in each group, the

central row of which is on the radial line y y, the other rows being parallel with the radial row, and all the teeth of each group being of the same size.

An gular vacancies necessarily occur between the groups m, and these vacancies are studded with such teeth as the spaces will permit. The dress of the plate A, Fig. l, varies slightly from that above described, but the same rule is observed as regards groups of parallel rows ot' teeth, and intervening angular spaces with teeth arranged in accordance with the character of these spaces.

It will be observed that in each plate some of the teeth are removed near the inner edge, thus affording vacant spaces for admitting be tween the grinding-surfaces the particles of bones passing lfrom the preparatory breaking portion of the mill, for it should be understood that the grinding-plates A and A represent the pulverizin g portion only of the mill.

I prefer to make each of the plates A and A with teeth on both sides, so that when the teeth on one side have become defective the plates may be reversed, thereby presenting new and serviceable grinding-surfaces.

Practical tests have proved that mills with. the abovedescribed dress are free from that undue heating which is a formidable defect in ordinary bone-mills.

I claim as my invention- The within described annular grinding plates, each having a dress composed of pyramidal teeth arranged in groups of rows, which are parallel with a radial line passing through the center oi' the group, as herein, set forth.

In testimony whereof I have signed my name to this speciiication in the presenceof two subscribin g witnesses.

ISAAC YEAR-SLEY, JR.

Titnesses IsAAo YEARsLnY, WILLIAM YEARsLnv.

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