US1790651A

US1790651A - Grindina machine

Info

Publication number: US1790651A
Authority: US
Publication date: 1931-02-03
Anticipated expiration: 1948-02-03

Description

Feb. 3, 1931. A. J. BERG ,5

GRINDING MACHINE Original Filed Aug, 16, 1927 fllgllullllllllllunn'g r INVENTOR lfi'ed I Berg- Patented Feb. 3, 1931 PATENT oFFIcE ALFRED I. BERG, OF PORTSMOUTH, NEW HAMPSHIRE Gamma moms Original application filed August 16,

My invention relates to grinding machines and particularly to machinesiidapted to re-" face valve seats by minding and truingsame to predetermined limits.

' It has for its general objects the provision of a power-driven grinding wheel and means;

for mounting same concentric with the axis of the cyiinder or the like element uponwhich the valve is seated; and the provision of means whereby the application of the grinding wheel to the valve seat is manually controlled and the depth of metal to be removed .is automatically limited by ready preadjustment of a precision gauge.

With the foregoing and other and more particular objects in view, as hereinafter pointed out, my invention consists of the features of improvement next herein set forth and described and illustrated in the accompanying drawings forming a part of this specification, and in which is shown that embodiment at present preferred by me as that best calculated to attain the features of advantage of my invention. In these drawings:

Figure 1 is an elevational view, partly 1n section, of a grinding machine operatlvely associated with the valve seatrof an engine cylinder;

Fig. 2 isja planview thereof;

Fig. 3 is a plan view of an attachment for dressing the grinder wheel; and v Fig. 4 is a sectional view of a' modification. 'Like reference numerals indicate like parts throughout'the several figures, 1n whlch 1 is the fixture which supports the valve seat- 3 and contains the guide 2 for the stem ofthe valve cooperating therewith. The valve is A motor 4 suitably connectedto a'power source has a shaft 5 on which is mounted the emery or like surfaced grinding wheel 6. ,T he motor is mounted upon a base -7 to whlch spindle 10 is screwed into the base 7, or otherwise rigidly aflixed thereto, and errtends downwardly into the valve stem guide or bore 2, to whose internal diameter it is adapt ed by the cylindrical bushing 11 screwed of course removed when the seat is ground.

it is clamped by the yoke 8 and bolts 9. A Y

1987, No. 213,277. Divided and this application filed August 19, 1929. Serial No. 887,071.

upon the spindle. The adapter bushing is free to turn in the bore. 1 1

A knurled micrometer thimble 13 consisting of a transversely split ring whose butting ends are drilled at 31 and threaded for a clampmg screw 17, is threaded for engagement on the spindle 10. The thimble carries the scale markings 14 which are adapted to register, as the thimble is revolved, with the scale markings 15'upon the flange, 16 depending-from and integral with the motor base 7. Bymeans of the clamping screw 17 passing through the threaded hole 31 in the ends of the split-ring forming the thimble of the micrometer,-the thimble may be clamped to the spindle, whereby the micrometer thimble turns with the spindle and maintains its adjustment for the depth of cut desired, as

be later described. 1

The grinder is preferably provided wit a-dressing attachment consisting of the support 18 held by the clamp 19 to the yoke 8 by screws and nuts 33. A head 20 on the support received the threaded bolt 21 havi g the wing-nut 22, the bolt 21 retaining 't e; thrust block 23 against the head 20.. The

frame members 24 extend from the head 20- 26 carried by the thrust block 23 and engaging the member 25. The slide has the series of holes 27 adapted to receive, as. required, the dressing tool 28 having the diamond point 29. The tool 28 isheld by a set screw- 30.v As will be understood, the angle of the slide holder and dressin tool is adjusted according to the conical ace of the grinding wheel, which in' turn is determined by the desired bevel of the valve seat.

The method of utilizing my improved grinder is as follows a A cylindrical bushing adapted to the bore of the cylinder in sliding contact is screwed upon the spindle. These are next inserted in the valve stem bore until the micrometer thimble rests upon the top of the wall 12 of the bore, the thimble being free to turn on its thread and adjusted to engage the wall of the bore before the grinder en a the valve seat. The micrometer thimb e is then 25 contmueduntll the grlnder removes no more rotated about the spindle in a direction to lower the motor base until the grinder wheel approaches the valve seat. The motor is then energized and further lowered until' the grinder contacts with thevalve seat, and a spark is struck by theirfrlctlon. The m1 crometer gauge is then read and from themdicated point is calculated the desired setting, the diiference being the thlckness of the metal to, be removed. ,The motor is then stopped and the micrometer thimble rotated in the reverse direction, while holding the motor stationary? with the'wheel 111 contact with the valve face, to a degree representing the thickness of the cut, as indicated by the micrometer reading, and there set by thetension-screw, whereby the thimble is held against further rotation upon the spindle. The lower face 32 of'the thimble will then be separated from the upper face 12 of the cylinder wall by the depth of the cut to be made. The motor head is then manually revolved withlthe rotating grinder in cutting engagement with the valve seat, the motor being, again energized and this cuttmg is metal. Whenever the grinder has cut to the predeter mined depth, it is automatically prevented from cutting deeper by the contact of the face 32 on the thimble with the stop face :afl'orded bythe face 12. When'thecutting is uniformly completed, the grinder wheel mayv be run at high speed and swung about over the surface of the seat to give the metal a glass-like finish. When the seat is thus burnished, the motor is then stopped. During the cutting operation the face of the grinding wlieel may betrued by traversing the dressing toolacross it by turning the screw, causing the slide to advance and retract the diamond point.

In Fig. 4 I have disclosed a modification of the centering device whereby the grinder may be more readily adapted to grind valves of engines wherein the valve stem guides have been enlarged by wear or for some other reason are not of standard uniform size.

In this modification the sleeve or bushing 11a isv not threaded upon the spindle as shown in Fig. 1' with its exterior surface of a size to rotate in the valve bore, but instead the spindle 10 of the grinder rotates in the bushing and the bushing. is fitted snugly in the valve stem guide. To this end the bushing 11a is provided with a knurled head or flange 35 at its upper end and immediately below I the flange is ta red through a portion of its length, the di erence in diameter at the upper and lower edges of the, tapered portion being about one-eighth of an inch. At its lower end the diameter of the sleeve is further reduced by a tapered portion '37 terminating in a screw-threaded hub 38 and mounted on the tapered portion is a split ring 39 adapted to be expanded by means of a knurled nut 40 threaded on the hub 38. The grinder is provided withthe micrometer thimble 13 threaded on the spindle 10 in the same manner as in the preferred construe-- tion. I

In using this modified embodiment of the invention, a sleeve adapted to drop loosely in the valve stem'guide'will be used and the nut 40 will be screwed upon the split ring until the latter is expanded to just fit the bore of the valve stem guide. The sleeve is then dropped in the valve stem guide and the vided, thus adapting the grinder to be fitted to valve stem guides of'all sizes.

While I have shown and described a par- .ticular organization as my; preferred e1nbodiment of means best adapted for the grinding of large valve seats, .Ido not wish to be understood as intending to limit my invention there-to, since I consider such means merely as an exemplifying disclosure, and believe my invention to be capable of. practice in a diversity of forms within the scope of the appended claims. division of my copending application Serial No. 213,277, filed August 16, 1927, which has n'iatured into Patent No. 1,725,126.

I claim 1. In a machine for grinding valve seats,

This application is a the combination of a motor, a cutting wheel driven thereby, a motor support, a spindle pro ecting downwardly from the motor support, a cylindrical bushing adapted to fit snugly the bore of the cylinder or the like whose valve-seat is to be ground, said bushing having a central aperture into which the downwardly projecting-spindle fits with a sliding contact, and means for adjusting the height of the motor support relative to the valve seat comprising a ring having a screw threaded connection with the downwardly projecting spindle and having its-lower face adapted to rest upon the top of the bushing to support the mechanism thereon, and.

means adapted to set said ring against rotat1on about the stem while permitting rotation of the spindlewithin the aperture of the bushing. v

2. In a machine for grinding valve seats, the combination of a motor, a cutting wheel driven thereby, a motor support, a spindle projecting downwardly from the motor support, a cyl ndrical bushing adapted to fit snuglythe boreof thecylinder or the'like" whose valve seat is to 'be ground, said bushing having a central aperture into which the downwardly pro ecting spindle fits with a sliding contact, a micrometer u on said spindle, means adapted to set sai micrometer against rotation about said s indle while permitting rotation of the spindle within said bushing, and means adapted to limit the downward movement of the motor support consisting of a stop face upon said micrometer adapted to rest upon the upper end of the bushing.

v 3. In a machine for rinding valve seats, the combination of a Inishing frictionally held within the bore of the valve stem guide v of the valve to be ground, a motor, a cutting spindle projecting wheel driven thereby, a motor support, a downwardly from the motor support an freely slidable vertically in said bushing, and means for adjusting the height of the motor supportrelative to the valve seat Comprising a ring screw threaded ,u on the spindle and having its lower face a apted to rest upon the top of the bushing to support the mechanism thereon, and means adapted to set said ring against rotation about the spindle while permitting rotation of the spindle within the aperture of the bushing.

4. In a machine for grinding valve seats having a motor, a motor support, and a spindle depending from the support, a bushing on said spindle adapted to allow the s indle to slide freely therein and adapted to e inserted in the valve stem guide of the valve to be ground, said bushing comprising a cylindrical body portion smaller in diameter than 1 the valve stem guide, and having an exterior conical portion near the top for engaging the top of the valve stem guide, and an expansible collar near the bottom for engaging the walls of the valve stem guide. 1

5. In a machine for grinding valve seats having a motor, a motor support, and a spindle depending from the support, a bushing on said spindle adaptedto allow the spindle to slide freely therein and adapted to be inserted in the valve stem guide of the valve to be ground, said bushing comprising a cylindrical body portion smaller in diameter than the valve stem guide and having an exterior con-- ical portion near the top for engaging the top of the valve stem guide, a tapered portion near the bottom, a split collar of resilient material mounted upon said tapered portion, a threaded portion, on the bushing beyond said tapered portion, and a nut upon said threaded portion adjacent said split collar for moving said collar longitudinally on .said tapered portion to vary the diameter of said collar.

In testimony whereof I afiix m signature.

' ALFRED BERG.