US75273A - Improvement in gbinding-mills - Google Patents

Description

G. W. HUBBARD & s. A. SMITH.

GRINDING MILL.

Patented Mar. 10, 1868.

I I a Mi'nesscs #M gums" fates gaunt ffim.

enonen W. HUBBARD. AND scorn A QSMl'FH, 0F PHILADELPHIA, P N SYLVANIA, ASSIGNORSTO cninsson '& SMITH, or SAME PLACE.

Letters Patent No. 75,273,- dated March 10, 18681 IMBROllEMINT INGRINDING-MILLS.

IO-ALL WHOM' IT MAY CONCERN Be it known that we, GEQRGE W. HUBBARD and ScOM A. SMITH, both of Philadelphia, Pennsylvania, have invented-certain Improvementsin Grinding-Mills; end we dc hereby-declare thc'following to be a full, clear,- "and'e'xact description of the' 'same.

-Qnr invention consists, of certain improvements, fully described heredfter, in what are known a's portable grin'dingmills;

' In order to enable others skilled in the art tov malieanduse our invention, we will now proceed to describeitsco'nstruction-and operation, reference being held to the accompanying drawing, which-forms' a part, of this specification, kind in which---' i Figure 1 is a vertical section of our-improved grinding-mm. Figure 2the same, showing the sever-s1 parts detached from each other. 7 Figure 3 a transversesection on the line 1-2, fig. 1. Figure;4 anexterioi: iriew of the burr; and

i, I Figure 5 a perspective .view of pert of the fly-wheel.

Similar le'tter'srefer to similar parts throii'ghout the severnl-yiews. I

IA. is u'hor'izoutsl spindle, secured to or forminga pert of which is a dish, 'a,huving a bevelled edge, sdnpted to the open end of theconicol burr B, to which the said disk-is confined by a suitablenumber offset-screws, b,

.the burn being fitted snugly st one end tothe spindle. D is the tapering shell of the mill, and. is confined between-the front plate E and rear plots F, in which plates the spindle A turns, the two plates being connected together-by bolts e, which also-serve to confine the hose-plate G tolthe plates, thesaid base being secui-ed'to-e platform or table, H, or to the" top of the box whichcontsins the bolting-nppara-tus Eorming a part of the plateF is the frame E, which serves to support 'the platform- I, into the under siddof which is fitted a projection on the upper end-of the curred arm J, the lowerend of the latter resting onthe Bshell D, and being fitted between andsecured to the plates Eand F, and the channel e formed on one side of'the arm communicating with an'openingf, in the shell. One end of a shoe, 7', is connected by s'screw-rod, m, nn'dnut m'to'the arm J, and

by a screw-rod, n, and nut it to the platform I, the opposite end of-the shoe being hinged toe. .hlock, K, which is arranged to slide beneath'the platform'Land which is-actedupon by a spring, p. The spindle is maintained ,in its proper longitudinal position in one direction by a collar, 11, hearingagainst is projection on the plate E,

and in the opposite direction by the hub in of the-fly-wheel MQ I As the spindle A, 'withiits'burr, is caused to revolve, the grain falls from the hopper-into the shoe 7', which is agitated by projections soon the fiy-wh'eel striking the block K. From the shoe the-grain falls into the channel 2 of the arm J, and passes downthe same-intothe openingf of'the shell, to be ground by thecombined action of the teeth of the lutter a'nd those on the burr, and finally posses oil in-a-trit-urated conditi'outhrough a spout, y, to the holt.

There are several peculiar features in. our improved mill, which we will now roceeds) describe. p

The first, and perhaps the most important, feature is the constructing of the shell'end' 'burrjofmsllesble cast iron, case-hardened. The burr B is first cast with appropriate teeth on it, then annealed or made inalles'ble then turned (if necessary) inside for the reception of the disk a, and bored to fit the spindle, and subsequently case-hardened, so" that its teeth partake of the chat-meterv of hardened steel. Before the casehardening, how ever, and while the dish a is in its place invthe burr, n sinooth portion, a", tigf'4, is turned on'the outer surface of the some, near the large-end for a purpose which will be rendered apparent hereafter;

During the above-mentioned processes of annealing andcas e-hardening,which take place in the absence 'of the disk, the burr is apt to become warped towards its open end, By i'einser'ting the dish a, however, and tightening the same in its place, thehurr is not only restored to its proper circular form, but'the turned portion a must he concentric withthe'disk and spindle. I p

' In like nianner the shell D is first cast with'appropriate internal teeth, then rendered malleable, and afterwards casehardened, after which the large end, which had heen'previously'turn-ed and fitted into a circular recess more [in the plate E, is now driven into the same,so that the shell is freed from all distortions which itmay have acquired during the annealing and case-hardening processes. The plate F is new applied to the=small end of the shell, and secured to the plate E.

i It will be understood that the modes described of rendering the burn or shell true, are applicable to mills which have burrs or shells made simply o'i' cast; iron, or other metal which is liable to become distorted with or without being case-hardened. I

It will be observed that there is a-hole; z", made'in one side of the -mill,,in the present instance, by cutting away the flange of the plate F. if, on looking through this hole, it be observed} that the space between the end of the burr and plate F is being filled up; or nearly so, it is a warning to the attendant to adjust thofeed-apparatus and reduce the supplyof grain. Inhand-mills this is. of great advantnge; as it enable the operator to work the mill at a uniform speed, and-to regulate the amount of grain ground, s'othat it shall be commensurate with the strength which he is capable of exerting. i

Another feature of our improvements is the mode of maintaining'the burr in its proper position-within the shell." In'ordinary grinding-mills the burr is forced into the shell by a screw actingbn one end of the spindle,

so that'its duty is limited to the preventing of the burr from moving backwards, no precaution being taken-toprevent it from coming in contact with the shell and-injuring the grindingsurfaceswof both, should -a proper supply of grain be wantin g in the mill, or shouldan undue longitudinal strain beimparted to the spindle'rhil it is being driven. v

These objections are obviated-by the adjustable collar won the spindle at i one end of the mill, and by the hub of the fiy-wheel,'rvhichacts-as an adjl'istable collaryon the spindle at the opposite end ofthe'mill Independently of the duty whichthese col'lars perform, of maintaining the burr in its proper position and I preventing the grinding surfaces from coming in contact, they aiford facilities for making on the shaft marks,

which, in connection with the collars, will serve'as-guides torestore the burr to its proper position in the shell after it has been changed. Graduated marks maybe made on'the' shaft, to indicate the proper adjustment for difl'erent degrees of finenessin grinding, 1

We claim as ourin'vention, and desire to secure by Letters Patent-- 1. The lever B, combined with and trued by the disk'a, substantially as described I 2. Jlhe shell 1), with its inclined edge adapted to the plate E, substantially as set forth. I 3. The spindle Awith its burr,whenconfi ned in its place within'the shell by two adjustable collars arranged. upon the'spindle, as specified. I Intestimony whereof, wehavesigned our names to this specification in the presence of two-subscribing witnesses. GEO. W. HUBBARD,-

SCOTT A. SMITH.

'Witness'em.

ALrnnn B. Srovnnn, A. B. Wmurs

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