US1786022A - Driving head for small lathes - Google Patents

Description

Dec. 23, 1930. H. G. MILLER 1,786,022

DRIVING HEAD F011 SMALL LATHES Original Filed April 27, 1927 //f0//ry Patented Dec. 23, 1930 HARRY G. MILLER, OF DENVER, COLORADO DRIVING HEAD FOR SMALL LATHES Application filed April 27, 1927, Serial No. 186,951. Renewed June 13, 1930.

This invention relates to improvements in driving heads for grinding machines and pertains especially to driving heads designed to rotate internal combustion engine valves about the axes of their stems during a valve grinding operation. The improvements herein disclosed are particularly designed to be used in machines of the general type described and claimed in my former application filed September 18, 1925, Serial No. 57,105. The valves to be ground difier in size and in the contour of their upper surfaces, in

accordance with. differences in the internal.

combustion engines for which they are de- 1 slgned, and also in accordance with the practice of the manufacturer. Some of these valves have flat surfaces provided with pin receiving sockets on opposite sides of their centers; othersare provided with diametrically extending channels; and others have dished or concave head surfaces provided with sockets or channels, which, in the different valves, are of differing lengths.

The object of this invention is to provide a driving head which will be generally and, so far as is possible, universally adapted to engage in the sockets or channels of valve heads of any kind in ordinary use for internal combustion engine or motor driven ve- Q hicles, whereby such valves may be positively rotated about the axes of their stems in contact with a grinding wheel or other abrading surface. I More particularly stated, the object of this invention is to provide a driving head adapted to be mounted .for rotation on a supporting head stock centering pin and which will be provided with axially yielding projections adapted to engage valve heads having widely spaced sockets to receive such projections; the chuck being equipped with a co-operating, yieldingly supported, floating member having valve e'ngaging projections which are located closer to the axis of rotation, and which may be in line with portions of the supporting pin and adapt ed to engage valve headsockets or channels beyond such portions of the pin,thus adapting the driving head for the engagement of valve heads having extremely short channels or narrowly spaced sockets.

In the drawings Figure l is a plan view of a work holding carriage for a grinding machine, showing a valve as it 'is'supported thereby for' a grinding operation, a fragment of the grinding wheel being also illustrated.

Figure 2 is a detail sectional view of the driving head and valve, drawn generally to a plane intersectingthe axis of rotation and showing fragments of the valve stem and supporting head stock, the dead center pin being illustrated in full. Figure 3 is a detail view of the driving head. Figure 4 isa detail view of the floating work engaging disc. I

{Like parts are identified by the same referen'ce characters throughout the several views. The carriage comprises a supporting 'bar 10 provided with a head stock lland tail stock 12. The head and tail stocks'are provided with supporting pins 13 and 1 1 respectively, tail stock pin 14 having a socket to I receive the end of the valve stem 16 and pressure beingapplied in the direction of the headv stock by means of a manually operated cam 17. A steady rest bracket 18 is secured to V the supporting rod or bar 10 and provided with a semi-cylindrical stem receiving rest 19 engageable with the valve stemnear the valve disc 20. These parts are all shown and described in said former application and for the purpose of this application may be regarded asof ordinary construction, the same not being claimed herein.

The driving head has a cylindrical body 22 adapted "to be rotatively'supported on the pin 13. It preferably carries a pulley 23 whereby 71 it may be driven by a belt 24, and it has work engaging pins 25 socketed in body apertures 26 at diametrically opposite points. The pins and their sockets are parallel with the axis of rotation. The apertures 26 have internal shoulders against which the pin heads 27 may seat when inserted from the rear or outer face of the body. Forward of these shoulders the apertures are reduced in diameter to substantially that of the pins, thereby providing guide bearings for the pins, the latter being urged to a normal forward projection by coiled springs 28 seated against the pin heads and held under compression by suitable plugs 29 threaded into the rear ends of the apertures. The projecting ends of these pins are adapted to yieldingly engage in correspondingly spaced valve head sockets, or channels of suitable length, whereby the valves may be rotated under power derived through the pulley 23.

It will be observed that the diameter of the spindle 13 imposes a minimum limit to the spacing of the pins 25 whereby it becomes impossible to socket such pins in the manner above described, much more closely to the axis of rotation than is indicated in Figure 2 of the drawings. here the sockets in the valve heads are more closely spaced, or where the valve heads have channel-s too short to receive these pins 25 it is necessary to provide auxiliary means for engaging such valve heads. For this purpose I provide a thin centrally apertured floating disc, or annulus, 30 which also has suitable apertures 31 adapted to loosely receive the pins 25. In a diametrical line at right angles to a line intersecting these apertures, I also provide-similar apertures 32 in which the reduced ends of a set of supporting pins 33 may be received, these pins having heads 34 of suliicient size to prevent dis-engagement of the annulus from the supporting pins 33. Pins 33 are mounted in the body 22 of the chuck in the same manner as above described with reference to the mounting of the pins 25, whereby the. supporting pins 33' and the annulus 30 may be pushed inwardly toward the body 22 when the pins 25 are engaged in valve head sockets.

The annulus30 is providedwith a pair of projections 36 located in close proximity to the centralaperture 37, which apertureis of less diameter than the pin 13, but ofsuificient diameter to receive a pointed end; 38 0f the pin. These projections 36 may be adapted to engage closely. spaced socketaperturesin the valve head or short channels therein. And, by employing a concavo-convex annulus with the projections extending from its convex surface it is obvious that the annulus may extend into concavely dished or recessed valve heads whereby relatively short projections 36 may be utilized, and power to rotate tlievalve transmitted through the supporting pins 33 and the annulus 30. Owing to the resilient mounting of the pins 33, the annulusmay be projected to, or if desired, even beyond, the ends of the pins 25 when the pro ections 36 areutilized to rotate a valve head. It 1s not necessary that the annulus 30 should be projected beyond the ends of thepins 25 for the reasonthat when the projections 36 are in use,the pins 25 may be pressed backwardly in their sockets by any portion of the valve head with which they may contact. Similarly as heretofore explained, the projections 36 and the annulus 30 may be pressed backwardly when the pins 25 are in use. In that case the pins 33 will be yieldingly moved into their respective sockets against the resistance of the springs therein.

Vi ith the above described construction it is possible to provide other pins corresponding with the pins 25 or projections 36 supported as above described in positions oven hanging portions of the supporting pins and thereby meet the requirements for a chuck which will engage and rota to any valve head in commercial use.

A driving head constructed. as illustrated in the drawings will meet the requirements for any valve heads now in use for motor driven vehicles. It will be understood that the point of the dead center pin will bear against the central portion of the valve hcad in line with the axis of the stem, and that it will operate as a. centering pin for the valve head. The point of the centering pin will co-operate with the operative set of work engaging projections above described in steadying the head while the work engaging projections are rotating it. v

I claim:

1. A driving head of the described class comprising a body portion, a set of work engaging pins resiliently socketed in the body portion at equal distances from the central axis and an independently acting carrier resiliently supported from the head and independently movable along said pins, the carrier being provided with work engaging projections at distances from the central axis different from those of said pins whereby to engage work which is not engageable by said pins for work rotating purposes.

2. In a drivin head of the described class the combination with a body portion havi an axial aperture tor the reception of a supporting spindle, and also provided with pin receiving seckets parallel with said axis a d at equal t nces therefrom, work engaging pins resiliently mounted in said sockets and a carrier annulus resiliently supported beyond the end of the body from which said pins project, and provided with work engaging projections in greater proximity to the axis than that of the said pins.

3. In a driving head of the described class the combination with a body portion having an axial aperture tor the reception of a snpporting centering pin, and also provided with pin receiving sockets parallel withsaid axis and at equal distances therefrom, work engaging pins resiliently mounted in said sockets, and a carrier annulus resiliently supported beyond the end of the body from which said pins project, and provided with work engaging projections in greater proximity to the axis than that of the said pins and in line with portions of said central aperture.

4:. The combination with a body, of a driving head for rotating valve heads in grinding operations, of a set of resiliently mount- 7 ed work engaging pins projecting from one end of the body, another set oi resiliently mounted carrier supporting pins, a carrier annulus loosely connected with the outer ends of the last mentioned pins and provided with work engaging projections, operative with-- in the field of operation of the first mentioned pins, said carrier being apertured to allow said first mentioned pins to pass for engagement with the work, and said carrier being provided with a convex outer surface upon which said work engaging projections are mounted.

6. A driving head for valve grinding machines comprising the combination of a body portion and plural sets of interchangeably acting work engaging projections, each resiliently supported from the body portion, said body portion being centrally apertured and one set of said projections being in line with the aperture in the body at opposite sides of its central axis. I

7. In a driving head for rotating valve heads in a valve grinding machine, the combination of a centering spindle provided with a tapered work engaging point, a body ro tatably mounted on said spindle and provided with driving connections, a set of work engaging pins resiliently socketed in said body and projecting therefrom along lines parallel to the axis of the spindle, a set of carrier supporting pins similarly socketed in said body,

a carrier member spanning the space between said supporting pins and having an opening through which the spindle point PIOIIeCtS,

and a set of work engag ng projections mounted on the carrier in line with portions of the spindle at opposite sides of its axis.

HARRY G. MILLER.

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