US2338484A - Grinding tool - Google Patents

Description

Jan. 4, 1944. R. s. BEVERLIN GRINDING TOOL Filed Jan. l2, 1943 VIA/ALIM Patented Jan. 4, 1944 GRINDING TOOL Robert S. Beverlin, Toledo, Ohio, assignor to The Hall Manufacturing Company, Toledo, Ohio, a

corporation of Ohio Application January 12, 1943, Serial No. 472,106

Claims.

This invention relates to grinding tools, and particularly to those of the portable eccentric valve seat grinding type.

In the use of tools of this character, it is the practice to mount them on pilot stems extending from the cylinder blocks through the respective valve seat openings whereby the rotatable grinding members of the tools are held in proper centered or grinding relation to the seats, and in accomplishing this it has been the practice, so far as I am aware, to mount a rotatable part or sleeve of the tool directly on the pilot stem. so that wear was not only occasioned between the coacting side surfaces of such rotating part and stem, but also between the upper end of the pilot stem and the coacting depth gauge stop member. 'Ihis wear, and particularly that between the coacting side surfaces of the stem and receiving sleeve, soon prevents the perfect tting of the parts which is necessary for accurate close dimension work, such as now required in engines used in automobiles and airplanes, and particularly the latter, and requires frequent replacement of the pilot stems as well as repair of the tools and replacing of the stem receiving sleeves thereof.

An object of the invention is the provision of a tool of the character described wherein the sleeve or part receiving the pilot stem is stationary relative to the tool housing, and lalso relative to the pilot stem so far as relative rotation thereof is concerned, when the tool is in use, thereby preventing wear between the stem and receiving part of the tool and obviating the frequent replacement of one or both of such parts, which has heretofore been necessary by reason of such wear.

Another object of the invention is the provision of a tool of this character wherein the depth gauge member and pilot stem are tied together when in use to prevent or resist different relative movements thereof and to provide simple and efficient means therefor and to lcause such stems and the receiving sleeve of the tool to combine to constitute a unit which is substantially stationary relative to the tool housing when the tool is in work grinding operation.

Another object of the invention is the provision y of an eccentric grinder type tool wherein the eccentric 'movements of the grinding wheel and its immediate carrying parts are not communicated to the tool housing.

Other objects and advantages of the invention will be apparent from the following detailed description and from the accompanying drawing, in which- Figure 1 is a central longitudinal section of a tool embodying the invention mounted in operative grinding relation to a valve seat, with the latter in fragmentary section and with parts in full; Fig. 2 is a side elevation of a tool embodying the invention; Fig. 3 is a cross-section thereof on the line 3-3 in Fig. 1, and Fig. 4 is an elevation of the eccentric sleeve member of the tool.

Referring to the drawing, I designates an engine block or head, 2 a valve seat therein, in the present instance of tapered form, and 3 a pilot stem firmly mounted in the associated valve stem guide 4 and projecting a distance up through and above the valve seat opening, as well understood in the art.

The grinding tool A, in which a part at least of the present invention resides, has a hollow 'housing I0 which is provided, at what may be termed its upper and lower ends, with axially aligned openings II and I2, respectively, with the former, in the ,present instance, smaller than the' latter. A bushing I 4 is mounted in the opening II with its inner end externally flanged and in outward thrust engagement with the marginal inner end wall ofthe opening. A sleeve I 5 is mounted at its upper end in the bushing I4, being threaded therein, and extends downward therefrom through the housing opening I2 in spaced relation to its wall and for some distance below such opening. 'Ihe lower end of this sleeve is intended to receive the customary pilot stem 3 and its upper end to receive the customary depth gauge stem I6. The sleeve I5 'is stationary or non-rotatable with respect to the bushing I4 and housing Ill.`

An eccentric sleeve I'I is rotatably mounted on the sleeve I5 with its outer end projected v through and beyond the housing opening I2 and in end thrust engagement with a flange I8 on the sleeve I5 and with its upper end in end thrust engagement with the bushing I4 through a gasket I9. A nut 20 threads on the upper end of the sleeve I5 in jam engagement with the outer end of the bushing I4 and the housing Il). A spiral gear 2I is provided on the upper end portion of the sleeve Il within the housing.

A hollow high sped spindle 23 is rotatably mounted on the eccentric sleeve Il in spaced relation thereto and immediately below the gear 2I through the medium of upper and lower sets of ball bearings 24 and 25, with the balls thereof preferably having their inner bearings in recesses formed in the sleeve and their outer bearings in race rings 26 fitted into the spindle. The spindle projects through and below the housing opening I2, being slightly smaller in diameter than said opening to permit the eccentricmovements produced by a turning of the eccentric sleeve I1.

A grinding wheel 30 is carried by the lower end of the spindle 23 for rotation therewith around the lower end of the stationary concentric sleeve I5. For this purpose the hub sleeve 3| of the wheel loosely receives the lower end of the sleeve I5 for rotary and limited lateral eccentric movements relative thereto and has its upper end enlarged and receiving the lower end of the spindle 23 to which it is threaded and in clearance relation to the outer marginal edge wall of the opening I2. It is apparent that when the stationary sleeve I5 of the tool is mounted on a pilot 3, the grinding wheel 36, due to its eccentric mounting relative to the sleeve and pilot, will be disposed eccentric to the valve seat so that it will have engagement with the seat at one side only of its axis, and that such point of engagement will progressively advance around the seat as the eccentric sleeve I1 is rotated.

In the present instance, the drives for the eccentric sleeve I1 and high speed spindle 23 are through a flexible shaft 35 having connection with any suitable power source (not shown). This shaft enters an enlarged side portion IIIa of the housing through a removable part 36 and has driving connection with a shaft 31 mounted in said portion. The shaft 31 has a spur gear 38 in mesh with the spur gear 39 on the inner end of the spindle 23 and has a worm 40 in driving connection with the eccentric sleeve gear 2I through a countershaft 4I (Fig. 3) and Worm gears 42 and 43 thereon. The driving connections between the shaft 35 and the spindle 23 and eccentric sleeve I1 are proportioned to cause a high speed driving of the grinding wheel and a low speed driving of the eccentric sleeve I1, which latter imparts a revoluble movement to the axis of the grinding wheel.

The depth gauge stem I6 is threaded into the upper end of the stationary concentric sleevey I5, is provided at its upper end with a knurled head to faciltitate turning and has its lower end adapted to rest on the upper end of a pilot stem 3 when the tool is mounted in operating relation thereon. The lower end of the gauge stem is preferably provided with a circumferential recess or groove in which a spring ring 45 of undulating form is mounted to exert a desired frictional pressure against the side wall of the sleeve bore to resist a free turning ofthe gauge stem in the sleeve..

In use, the pilot stem 3 and gauge stem I6 are tied together in end to end engagement by a rod 46 which is projected axially through one of said stems, being controlled from the outer end thereof, and threads into the other stern. In the present instance, the rod 46 is projected through an opening in the pilot stem 3 and has its lower end projected in accessible position below the lower or outer end of such stem and provided with a head 41 to facilitate turning with a wrench, screwdriver, or other suitable tool. The upper end of this rod threads into a socket in the lower end of the gauge stem I6. In the present instance a locking nut 48 is threaded on the lower end of the pilot stem against the collet 49 and projects a distance from the lower end of the stem to receive a coiled expansion spring 50 around the rod 46 in thrust engagement at one end with the lower end of the pilot stem and at its other end against a washer 5I which bears outward against the head 41 of the rod and also has engagement with other stop means in the member 48. The rod 46 is intended to be screwed into the guide stern I6 in seating or shouldered engagement therewith, and when so seated the washer 5I is raised to some extent from its seat on the nut 48 by the head 41 of the rod and against the tension of the spring 50. When, during operation of the tool, the guide stem I6 is turned to elect a feeding adustment ofthe tool relative to the pilot 3, the rod 46 turns therewith within the pilot stem due to the yielding connection of the rod with the pilot stem through the interposed spring 50. It will thus be apparent that while the guide and pilot stems are tied together by the rod 46 and spring 50, such tying is not so rigid and positive as to prevent a turning of the guide stem for the purpose of feeding adjustment. This tying together of the gauge and pilot stems also causes one to serve more or less as a rigid extension of the other and to thereby cooperate to brace and hold the tool in proper centered relation to the valve seat being ground. The stationary mounting of the concentric pilot stem receiving sleeve I5 in the tool housing not only eliminates wear between the pilot stem and such sleeve, but also makes possible the tying together of the gauge and pilot stems in an eflicient and simple manner.

I wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.

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

1. In a tool of the class described, a sleeve for receiving a pilot to center the tool with respect to the work, a grinding wheel carrying spindle encircling said sleeve in spaced relation thereto, a mount for said spindle which4 is rotatable around the sleeve and eccentric to its axis, and means for rotating said spindle and mount at different predetermined speeds.

2. In a tool of the class described, a stationary sleeve for receiving a pilot stem to center the tool relative to the Work, an eccentric sleeve mounted on the first sleeve for rotation about its axis, a grinding wheel carrying spindle mounted on the eccentric sleeve for rotation about an axis eccentric to the rst sleeve axis, and means for rotating said eccentric sleeve and spindle at different predetermined speeds.

3. In a tool of the class described,l a housing having openings at opposite ends, a sleeve stationarily mounted in one opening and projecting through the other in spaced relation to its Wall and beyond the housing to receive a work centering pilot, a grinding wheel carrying spindle rotatable about said sleeve and projected through said last-mentioned opening in spaced relation to its wall, means around said sleeve forming a rotatable mount for said spindle which is eccentric to the sleeve axis, and means-for driving said mounting means and spindle at diierent predetermined speeds.

4. In a tool of the class described, a housing, a sleeve stationary with respect to the housing and projected therethrough with one end adapted to receive a work centering pilot and the other end adapted to receive a pilot engaging depth gauge, a grinding wheel carrying spindle rotatable about the pilot receiving end of said sleeve, a mount for said spindle eccentric to the sleeve axis and rotatable therearound, and means for driving said spindle and mount at diierent predetermined speeds.

5. In combination, a portable valve seat grinding vtool having a housing and a sleeve stationarily mounted therein and projecting therethrough, a depth gauge stem adjustably mounted in one end and a work centering pilot stem slidingly tted into the other end of the sleeve with the inner ends of said stems in stop coaction, and means operable from without one of said stems and projected lengthwise therethrough for tying vthe stems together whereby said stems and sleeve combine to constitute a unit which is substantially rigid relative to the housing when the tool is in work grinding operation.

6. In combination, a portable valve seat grinding tool having a housing, a sleeve stationarily mounted in and projected through said housing, a grinding wheel rotatably mounted around said sleeve with its axis of rotation eccentric to that of the sleeve, together with a Work centering .pilot stem slidingly tted into one end of said sleeve, a depth gauge stem threaded into the other end of the sleeve in stop coaction with the inner end of the pilot stem, and means operable from without one of said stems and projected lengthwise therethrough for yieldingly tying the stems together whereby said stemsand sleeve combine to constitute a unit which is substantially rigid relative to the tool housing when the tool is in work grinding operation.

7. A combination as called for in claim 5 wherein thetying means is projected through the pilot stem.

8. A combination as called for in claim 5 wherein the tying means is projected through the pilot stem and spring means is interposed between the pilot stem and the tying means to cause a yielding tying engagement of the two stems.

9. In an eccentric tool of the class described, a housing, a sleeve mounted in said housing and open at one end to receive a stationary pilot stem projecting from the work to be ground, a mount on said sleeve within the housing for free rotation thereon with its axis eccentric t0 that of the sleeve, a spindle mounted for free rotation on said mount and having an end projecting without the housing, a -grinding wheel fixedlycarried by the projecting end of said spindle, and means for driving said mount and spindle relative to the housing and at different speeds.

10. In a tool of the class described, a housing, a sleeve stationary with respect to the housing with one end open without the housing and adapted to receive a Work centering pilot and the other end adapted to receive a, pilot engaging depth gauge, a depth gauge adjustably mounted in said other end of the sleeve, and a grinding wheel carrying spindle mounted for rotation about the pilot receiving end of said sleeve with its axis of rotation eccentric to the sleeve axis.

ROBERT S. BEVERLIN.

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