US1048307A - Universal joint for grinding-mills. - Google Patents

Description

E. C. GRIFFIN, DECD. L. M. GRIFFIN; BXIIUUTR'IX.

UNIVERSAL JOINT FOR GRINDING MILLS.

APPLICATION FILED MAY 4, 1912.

i' 1,048,3. f Patented 136624,1912.

EDWIN C. GRIFFIN, lm' GRIFFIN, EXEC/ li.'

PULVERIZER Gi., f

,.ASED, LATE OF NEWTON, MASSACHUSETTS, BY LOVINA M. GF ASHMNT, MASSACHUSETTS, ASSIGNOR TQ BRADLEY STCE, ifiESr'CHUSETIS, A CORPORATION OF MAINE.

Specification of Letters Patent.

Patented Dec. 24, 1912.

delineation :"ied a, 1912. Serial No. 695,179.

To all whom z'z may co Be it known that ceased, late of NeyY y sex, State of Massa i did invent an Improvement in Un `sal Joints for Grinding-Mills, of which the following de scription, in connection with thel accompanying drawing, is a specification, like characters on the drawing represent-ing like parts.

This invention relates more particularly tomills for pulverizing or grinding rock, ore,islag or other refractory lmaterial. by the act1on of a suspended revoluble roll havmg a gyratory action with relation to the suspension. means therefor and which coperates with an annular die, a mill of this type being shown in United States Patent No.

(l Gruissan, de ny of Middlel1,020,092, dated March l2, 1912. In such mills the suspending means usually includes an overhead and suitably supported driving shaft having an attached pulley connected by belting With a proper source of power, the grinding roll shaft being connectedwith such overhead shaft by a substantially universal coupling, in such manner that the roll .shaft is suspended and rotated positively Without interference with the ratory mo- ,tion thereof when the mill is' in operation..

The coupling comprises essentially a rotating outer member and an inclosed coperating rocking member which is rotated bodily and positively in unisonv with the outer member, the latter being iixedly attached to the driven shaft. This inner member is made as a cross-head having radial arms or trunnions extended laterally' therefrom and carrying segments which have their bearings on concave seats inthe outer member, as for instance in Patents No. 721,035 dated February 17, 1903, and No. 922,579 dated May 25, 1909. As shown therein the head has a central tapered hole to receive the correspondingly ta;y the roll shaft, Whit.. is eid in the crosshead by a nut screwed onto the threaded extremity of the shaft projecting above the top of the cross-head. has been found in practice that this construction is objectionable, for thejar and shock to which the parts arc subjccted'by the operation of the mill tend to loosen the retaining nut, so that the roll shaft is not held as rigidly and red upper end of' be ,effected easily and rapidly with a minimum expenditure of time and labor.

The Various novel features of the invention will be fully described in the subjoined specification and particularly pointed out in the following claims.

Figure l is a view in elevation and section of a sufficient portion of a grinding mill of the type referred to, with a practical form of the present invention embodied therein; Fig. 2 is an enlarged top plan View of the cross-head from which the roll shaft is suspended, showing the seats for the sliaft-i'etaining member; Fig. 3 is a right hand side elevation of the cross-head, the tapered end of the roll shaft and the retaining member therefor being shown by dotted lines; F ig. 4 is a vertical section of the crosshead taken through the Center thereof on the line 4-4, Fig. 3.

Referring to Fig. l, the frames 15 carrying the annular member 17 which forms a concave seat for the bearing 19, the cross piece 2() supported by the frame, 16, and sustaining t e seat 21 for the bearlng 22 of the depending shaft 27, having its ower end securcdin the hub 28 of the driving pulley 29; the tubular port-ion 30 bolted to and depending from the pulley hub and terminat` ing in a flared tubular extension 3l onto which the bearing 19 is clamped; the annular internal shoulder 32, and the concaved bearing ring 33, may be and are all substantially as in Patent No. 1,020,092. The hub 28 and attached depending portion 30 constitute an inclosed outer or socket member of the coupling which connects the suspending shaft 27 and the suspended roll shaft, to

made as helical surfaces, the low portions of are diametrically disposed and upright eon-4 cave seats 50, 50 each seat being conveniently made in two parts, as shown, and coperating with the convex end faces of segments 51 centrally apertured to fit easily upon oppositely extended arms or trunnions 52 which project radially from a cross-head 53. The cross-head has a tapered axial hole 54 for the reception of the correspondingly tapered upper -end 55 of the roll shaft 56, Fig. 1, it being understood that said shaft in practice carries. at itslower end. a suitable grinding roll, as in Patent No. 1,020,092.

The described structure provides a universal coupling between'the shafts 27 and 56, as will be apparent, in a manner similar to the couplings shown in Patents Nos. 721,035 and 922,579, the Weight of the roll shaft, roll and cross-head bein sustained by the suspension member 57 ,ma e as a spherical segment and seated in the concaved bearing 33. As such segment is subjected to hard wear it is made of manganese steel or other suitable wearresisting metal, and separate from the crosshead, so that it can be readily renewed when necessary, the segment being apertured centrally for the shaft, the bottom of the crosshead seating upon the flat upper face of the segment. Herein the retaining nut for the roll shaft, and the threading of the latter for the nut, are obviated altogether, and instead of such retaining means a steel pin 58 is driven through a 'transverse hole in the tapered part of the roll shaft, the projectin ends of the pinv resting upon diametrica v opposite cam seats 59 formed on the top of the cross-head. Said cam seats are oppo- Sitely inclined, as shown, and preferably are said seats being adjacent abutments 60,' the abutments being parallel to each other and offset at opposite sides of a diameter through the axial center ofthe crossfhead, as shown in Fig. 2.`

- When assembling the 'cross-head and roll shaft the tapered end 55 of the latter is inserted in the hol'ef5fi of the cross-head and the retaining pin 58' is driven into positionA through lthe shaft, the ends of the pin resting on tlie'cani seats at their low points, adjacent the abutlnents G0. The exact position of the pin' on the seats depends upon the fit of the shaft in the hole 54, the farther inthe shaft extends the higher upon the seats willy the ends of the pin rest initially. Rotation of the cross-head lis in the direction of the p arrow, Fig. 2,that is, from the high toward the low 'arts of the cam seats, in conse-- quence o which the project-ing ends of the 'pin alweysfutend'i'totravel toward the high `parts of 'theseatsf This coperation of the ""pin and 4the cam seats acts `to pull the shaft upward. intro its tapered hole 54 in theloross head, as w1 be manifest, so thatl the reater the resistancf` to rotation offered yg the shaft the more securely and firmly will the described connection draw together the shaft and cross-head. i

As the parts are all inclosed and have no relative movement, once the shaft and cross-head have been drawn together by the described cam action, it will be obvious that there 'is no wear, and the connection will last indefinitely.

It is impossible loose in the cross-head when the mill is in for the shaft to become operation, manifestly, owing to the selttightening action of the connection between such parts, yet when it is necessary to separate the parts it can be easily effected b reversing the rotation of the 4crosshea ,as thereby the.ends of the retaining pin are caused to travel down the helical seats toward the abutments. i

The trunnions are made hollow, as shown, for the reception of lubricant, and oil holes 61 are drilled through the cross-head and through the suspending segment 57, Fig. 4.

Oil ducts 62 lead through the pulley hub 2S to the interior thereof from a lubricating cup or chamber 63 bolted to the hub and surrounding the shaft 27, whereby the lubricantcan be introduced to the interior of the inclosingor socket member of the shaft-cou` pling.

The particular construction of the shaftcouplingmay be varied or rearranged as may be convehient, and various other parts of the apparatus may be changed orniodified without interferinr or departing from the spirit and scope o the present invention as set forth in the .claims hereunto annexed.

Having fully described the invention, what is claimed and desired to bey secured by Letters Patent is:

1. In a grinding mill of lthe class described, a driving shaft, a suspended roll shaft having a tapered upper end, a universal Vcoupling including an inclosing member attached to the driving shaft and an inclosed rocking lnember having a tapered holel for the upper end ofv the roll shaft, oppositely inclined cam seats on the top of the inclosed member adjacent the shaft hole, und a retaining pin extended through the projecting end of the shaft and having its opposite ends resting upon the seats, whereby rotation of the coupling in the direction of the lower portions of the cam seats causes the latter to coperate with the retaining pin and draw the roll'shaft and cross-head together.

2. The combination with a driving shaft, 'a suspended shaft to be driven, and a universal coupling between them and from which the driven shaft is suspended, the coupling including a member having a tapered hole for the correspondingly tapered upper end of the suspended shaft, of arr automatically tightening connection between said shaft and coupling membery comprising oppositely inclined cam seats on the top of the coupling member and radial projections on the tapered end of the shaft resting upon and'upheld by the cam seats.

3. The combination with a driving shaft, a suspended shaft to be driven, and a universa-1 coupling between them and from which the driven shaft is suspended, the coupling including a member having a tapered hole for the correspondingly tapered upper end of the suspended shaft, of an automatically tightening connection between said shaft and coupling member, compris# ing seats on the top of the coupling member diametrically oppo'site each other and having oppositely inclined helical surfaces, and a pin extended through the projecting end of the shaft and resting upon the helical surfaces at opposite sides of the shaft.

4. In a grinding mill, an overhead driving shaft, a suspended gyratory roll shaft,

'Aa universal coupling between the shafts and from which the 4roll shaft is driven, the coupling including an inclosed rocking cross-head havingian axial, tapered hole for the correspondingly tapered upper end of thel roll shaft, oppositely inclined helical seats on the top of the cross-head at opposite sides of the shaft hole, and a coperating pin passed through the shaft above the crosshead, the projecting ends of the pin resting upon and being 'supported by the seats, rotation of the coupling toward the low portions of the seats causin the pin to travel up said seats and thereby draw the shaft tightly into the cross-head.

5. In a grinding mill, an overhead driving shaft, a Asuspended gyratory roll shaft, a universal couplingpbetween the shafts and from which the roll shaft is driven, the coupling comprising an outer member provided with an annular, coaxial bearing, and a cross-head mounted to rock in the outer member and having a tapered axial hole for the correspondingly tapered end of the roll shaft, a suspendingHmember surrounding the shaft and interposed between the crosshead and said annular bearing, and an auto'- matically tightening connection between the roll shaft and the cross-head, comprising oppositely inclined helical seats on the top of the latter and a transverse p'in carried by the shaftand resting upon the seats', operative rotation of the coupling causing the pin to travel up the seats and thereby draw the roll shaft tightly into the cross-head.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

LOVINA M. GRIFFIN, E'ecuzfrz'x of estateEdfwz'n O'. Grfin, (Zeceased. f

lVitnesses:

J. E. GRIFFIN, FRED M. MoN'rGoMEnY.

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