USRE786E - Improvement in balancing mill-stones - Google Patents

Description

UNITED STATES PATENT OFFICE.

JOHN FAIRCLOUGH, OF LOUISVILLE, KENTUCKY.

lMPROVEMENT IN BALANCING MILL-STONES.

Specilicatiou forming part. of Letters Patent No. 22,356, dated December 2l, 1858; Reissue No. 786, (lated August 2, 1859.

To all whom it may concer-n:

Beit known that I, JOHN llAIRoLoUGH, of Louisville,in the county of Jefferson and State of Kentucky, have invented a new and useful Improvement in Balancing Mill-Stones and I do hereby declare that the following is afull, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, in Which- Figure l is a vertical central'section of an` upper mill stone or runner with my invention applied 4to it, and also biseeted. Fig. 2 is a plan or top view of the same. Similar letters of reference indicate corresponding parts in the two figures.

rlhis invention consists in the employment or use of adjustable weights fitted in the upper stone or runner in such amanner as to admit of the perfect balancing of the stone both as regard its gravity or weight and the centrifugal force generated by its rotation.

To enable those skilled in the art to fully understand and construct my iuvention,I will proceed to describe it. Y

A represents an upper mill stone or runner of usual construction. B is the bail, which is fitted in the eye c; and() is the driver, placed on a spindle, l), and having its ends fitted in recesses in the driver. The lower end of the spindle is stepped in a box, E, which rests on a bridge-tree, F, that is regulated or adjusted by a screw-rod,G, as plainly shown in Fig. 1.

The above parts are of usual construction, and therefore do not require a minute description.

In the upper surface of the stone A recesses b are made to receive cylindrical metal boxes H. These boxes are fitted in the stone near its periphery, and four may be used at equal distances apart. I do not, however, coniine myself to any particular number, although perhaps four would be preferable. The boxes are each provided with a cover or cap, c, the caps being secured to the boxes by screws d. lhe boxes H extend down to the lower part of the stone, and each has a metal cylinder, I, fitted within it. The cylinders I are considerably shorter than the boxes H, in order to allow the former a requisite degree of adjustabilty within the latter, (See Fig, l.) The cyl inders I have each a vertical tube., e, fitted centrally wit-hin them, the lower ends of the the tubes e.

tubes heilig attached to traverse or cross bars F, at the bottoms ofthe cylinders. The tubes e have screw-threads formed on them, both inside and out, and a screw, g, passes througheach tube, said screws also passing centrally through the caps c, the lower ends being steppedjn the bottoms ofthe boxes H. In the upper part of each cylinder I a circular plate, h, is fitted. These plates are screwed on the tubes e, and in each cylinder a series of weights, t', are placed. The bottoms j ot' the cylinders rests on nuts k, which are fitted on The `cylinders I are provided with two projections, l, at opposite points of their peripheries, and these projections litiu slots or grooves fm in the boxes H, and serve as guides to the same, and prevent their turning with the screws From the above description it will be seen that the stone A may, so far as its gravity is concerned, be readily balanced on the spindle D by the weights c', more or less being placed in each cylinder, so as to eleet the result; but by doing this it will be observed that when the stone is rotated centrifugal force will be generated, and this adjustment of the weights in order to balance the stone on the spindle may cause a lateral pressure and an undue degree of friction on the collar of the spindle D. For instance, if one cylinder, I, has half its weigh ts removed and the opposite cylinder is full, in order to balance the stone, it will be seen that when the stone is rotated the side .of the stone which has the greater number of weights i will, owing to centrifugal force, have agreater tendency to fly o in a tangent than the opposite side, it being understood that the center of gravity of the weights is supposed to be in the same horizontal plane. In order, therefore, to remedy this difficulty,

-the cylinders Iare rendered adjustable 'and raised and lowered within the boxes H by turning the screw g, and the center of gravity of the wei ghts may be adj usted relatively with the point ofthe spindle D, so as to neutralize this unequal centrifugal force. If but few weights are in a cylinder, the cylinder requires to be elevated, so as to increase the distance between the point of the spindle and the center of gravity of the weights. lf many weights are in a cylinder, their center of gravity is brought in line or in the same horizontal plane with the point of the spindle. ln case but`few Weights i are employed in a cylinder, these few must necessarily be adjusted in the upper part of the cylinder and box H. The cylinder in this ease may be removed, the nuts secured in proper position by the nut 7c on the tube E, and the cylinder be inserted in its box H, so as to bring the Weights to the upper part of the stone A. The Weights may always be retained'in proper place 'by the plates h, so that when the stone is inverted for the purpose of being picked, or for other purposes, the Weights will be retained in proper place.

I do not conne myself to the means herein shown and described for adjusting the Weights in the stone, for various plans might be devised for the purpose. Y

I am aware that fixed Weights have been inserted in the backs of the mill-stones for the purpose of balancing them in a state of rest; but I am not aware that adjustable weights have been employed and arranged so as to balance the stone both as regard its gravity or Weight andthe centrifugal force generated by its rotation.

I claim, therefore, as new and desire to secure by Letters Patent- The employment or use of Weights i, placed Within boxes or recesses in the back ofthe stone and arranged, substantially as described, so that they may be adjusted vertically, and more or less be used in each box or recess to admit ofthe balancing of the stone or runner both while in motion and at rest.

JOHN FAIROLO UGH.

Witnesses N.. W. WALLER, J OsKENNEDY.

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