US50274A - Improvement in grinding-m ills - Google Patents

Description

No. 50,274. Patented oct. 3, 1865.

Y"UNrTar-r STATES PATENT OFFICE.

JAMES O. ROBERTS, OF ADAMSTOWN, MARYLAND.

IMPROVEMENT IN GRINDINGMILLS.

Specification forming part of Letters Patent N0. 50,274, (lated OCtOber 3, 1865.

To all whom it may concer/a:

Beit known that I, JAMES C. ROBERTS, ot

y Adamstown, in the county of Frederick and ings,which are made part of this specification,

and in whichy Figures 1 and 2 are side elevations of the frame supporting the stones and of the attached devices by which the runner is regulated. Fi g. is a central vertical section on the line .fr Fig. 1. Fig. i is an enlarged view of the uut and screw, the latter rotating'to elevate or depress the bridge-piece on which the spindle ot the runner is imposed. Fig.5 is an elevation, and Fig. 6 a top view,of the double-bitted dog and cog-wheel, the former engaging the latter by one or the other of its bits, according to the direction ofrotation ofthe crank-shaft on which the bits are keyed.

Similar letters refer to corresponding parts in the different gurcs.

The object of my invention is to cause the runner when adjusted to grind at. a given weight for the production of a certain amount of Hour to maintain its set, notwithstanding the varying expansion of .the spindle.

It is manifest that when the spindleis heated it becomes elongated, and when it has a detinite and unyielding bearing upon the bridgepiece by the said expansion the ruimer is lifted and the set is lost.

My improvement is designed to lower the bridge-piece, which supports the spindle on which the runner is poised, so as exactly tomalie up for the said elongation ofthe spindle and maintain the stone at the set required,the reverse operation taking place on the cooling ot' said spindle. Theliftingot' the runner adds to itsweight upon the bridge-piece as it is borne up to a less extent by the grain, and this variation in weight is caused to deliect a scaleheam and move a crank whose shaft, through the medium of adouble-bitted dog and connecting-gears,lowers the outer or movable point of suspension of the brid ge-piece and restores the runner to its proper relational distance from Wille bed-stone.

To enable one skilled in the art to which my improvement is allied to construct and use the same I will proceed to describe it.

A is the frame, on which the bed-stone B is planted, and O is the runner, supported bythe spindle D upon the bridge-pieceE, oneof whose ends is hinged at F and the other supported by the screw-rod G, wheel-nut H, and rod I from the sale-beam J, which derives its support from the frame at K. This describes in brief terms the support of the bridge-piece, but from what has already been said it is evident that a means must be provided for moving the point E ot' the bridge-piece as the spindle D contracts or expands, and this is accomplished by means to be now described.

The required pressure of the runner being graduated by the weight L on the scale-beam J, and the mill being set in operation, should the spindle becomeeelongated the short end ot' the beam J will he depressed and the otherend, j, will be raised, rotating the crank M, whose shaftNcarries a dog with two bits, O O. The said motion throws one of the said bits into engagement with cog-wheel P.

At the end of the scale-beam J is a hanger, m, having a slotin which the wrist of the crank M works hack and forth under the motion ot' thevibrating arm V, the said oscillating motion not disturbing the hanger, but the elevation of the hanger m raising and lowering the wrist.

So much for the means of bringing the bit in contact with the wheel; but now to describe the means by which it moves the said wheel.

On the spindle D is a bevel-gear wheel, Q, which gears into a wheel of similar character,

R, on a shaft, S, on which is an eccentric, T,l

giving a reciprocating motion to a connectionrod, U, and vibrating a frame, V, which has an oscillating motion on a center, WV, land carries at its upper end the shaft N and the doublebitted dogO O above spoken ot'. This frame, through the means described, has a constant oscillating motion, and the dog is constantly hovering over the wheel P and so long as the given adjustment is maintained failing to engage with the cogs ofthe said wheel; but when, from the causes above adverted to, the shaft N is rotated in either direction, then one or the other bit descends, and coming in contact (Fig. 5) with the wheel gives it a partial rotation, which is continued on the recurrence of the stroke of the frame'V until the'inciting cause is exhausted by the runner assuming the required proximity to the bed-stone by means of the devices, which I will now describe, which connect the said cog-Wheel P with the Wheelnut H, and by rotating it raise or lower the screw-rod G and lthe bridge-piece E, which is supported thereby.

On the shaft ot' the cog-Wheel P is a bevelgear Wheel,X, which gears into awheel of similar character, Y, and that by means of the spurwheel Z on the same shaft rotates the Wheelnut H by engagement with its teeth h.

The runnerjs driven by a band upon a pulley (not shown) on the shaft S.

The operation of the machine has been incidentally' described in the current description of the parts, auditis believed to be sufficiently clear. In general terms itis as follows: Supposing the mill to be set in motion,thelength ening ofthe spindle due toits becoming.;` heated raises the runnerfarther from the bed-stone and 4increases its pressure upon the bridge-piece. The increased weight raises the long end ofthe scale-beam, and by intervention ofthe hanger partially rotates the crank on which the double-bitted dog is attached, the appropriate bit rotatingthe cog-Wheel which connects with the wheel-nut, and by rotating it causes it to aseend on the screw-rod from which the bridgepiece depends, lowering; the latter and with it the runner. An adjustable spring may be sub-A stituted for the Weighted scale-beam. The cooling ofthe spindle reverses the motion andthe falling of the longer arm ot' the scale-beam throws the other bit of thedog in connection with the wheel to rotate it in the other direction and raise the bridgepiece.

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

l. The vibrating pawhframe or its equivalent7 operated from the driving power of" the mill, in combination with the interposed gearing and adjustable suspensionrod for raising or lowering the bridgepiece.

2. The Weighted scale-beam or its equivalent,from which the bridge-piece is suspended and whose oscillations on either side oi' the given point of adjustment actuate the mechanism for raising and lowering the bridge-piece.

3. In this connection and automatically operated, the rods G and I and wheel-nut H, forming a suspension rod adjustable as to length for the support of the movable end of the bridge-piece.

JAMES C. ROBERTS.

Vitnesses:

ELIAS SPALDING, Jus. L. ROBERTS.

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