US2466359A

US2466359A - Valve seat grinding means

Info

Publication number: US2466359A
Application number: US692621A
Authority: US
Inventors: Robert S Beverlin
Original assignee: Vickers Inc
Current assignee: Vickers Inc
Priority date: 1946-08-23
Filing date: 1946-08-23
Publication date: 1949-04-05
Anticipated expiration: 1966-04-05

Description

April 5, 19 49 R. s. B-EVERLIN VALVE SEAT GRINDING MEANS 3 Shegts-Sheet 1 Filed Aug. 23, 1946 FIE-3- INVENTOR.

April 5, 1949' R. s. BEVERLIN I 2,466,355

VALVE- SEAT GRINDING MEANS Filed Aug. 23, 1946 3 Sheets-Sheet 2 INVEN TUR. 1-1. UBERT SBEVEHLIN April 194.9- R. s. BEVERLIN 2,466,359

VALVE SEAT GRINDING MEANS Filed Aug. 25, 1946 3 Sheets-Sheet 5 mmvrm HUBER? EBEI ERL N v Patented Apr. 5, 1949 VALVE SEAT GRINDING MEANS Robert S. Beverlin, Toledo, Ohio, assignor, by mesne assignments, to Vickers, Incorporated, a

corporation of Michigan Application August 23, 1946, Serial No. 692,621

'7 Claims.

This invention relates to machines of the type intended more particularly for grinding or refacing the valve seats of internal combustion engines, and especially but not necessarily to those of the eccentric grinding type.

In the use of machines of this character, where the grinding means is carried by a stationary frame, there are customarily two fixed points between which the guide pilot for the grinding wheel and its spindle must work, one being the stationary frame part by which the grinding means is carried and the other the valve stem guide associated with the cylinder valve seat being ground, and in order to prevent binding or distortion of the grindings parts, it has been necessary that these centers be axially aligned. The objections encountered in such cases where the valve seats of a number of cylinders are being simultaneously ground. It is also found that such troubles are exaggerated where long grinding wheel carrying spindles of a type to extend down into the cylinders-to act on internal seats therein are employed.

The primary object of the invention is to obviate the above-noted objection in the use of machines of this character by the provision of means for permitting the grinding mechanism and guide pilot to automatically accommodate themselves to the position of the work relative to the stationary frame part from which suspended so that self-aligning may take place and proper grinding be effected without a binding action.

Further objects and advantages of the invention will be apparent from the following detailed description and from the accompanying drawings forming a part thereof, and in which- Fig. 1 is a side elevation of a machine embodying the invention, with the several grinding mechanisms in operative relation to a cylinder block; Fig. 2 is a front elevation thereof with the cylinder block removed and indicating in dotted lines the grinding spindles in various outof-normal positions necessary to axially align the grinding means pilot with respective fixed centers; Fig. 3 is an enlarged section on the line 3-3 in Fig. 2, with parts in full, and with the grinding means in operative relation to a cylinder valve seat to be ground; Fig. 4 is a section similar to Fig. 3, except that it is further enlarged, and more complete, and extends only from a point imme diately below the grinding head carrier and only partially shows the cylinder block; Figs. 5 and 6 are sections on the lines 55 and B--6, respectively, in Fig. 4; Fig. 7 is a fragmentary section on the line l! in Fig. 6; Fig. 8 is an enlarged crosssection on the line 8--8 in Fig. 2, and Figs. 9 and 10 are perspective and sectional views of the collet member of a pilot.

Referring to the drawings, l is a frame having a base portion 2 and a head portion 3 with a bracket 4 on the front of the former for supporting the work to be acted on, which work, in the present instance, is the cylinder block 5 of an internal combustion engine. A fixture 6 for holding a cylinder block is mounted on the top of the bracket 4 for various horizontal adjustments to permit locating the cylinder block in position for refacing or grinding its internal valve seats.

In the present instance, the cylinder block is firmly held at top and bottom, but as any suitable means may be provided for holding the block and no novelty, so far as this application is concerned, is claimed therefor, it need not be more specifically described.

The cylinder block is mounted with the lower or open ends of its cylinders disposed upwardly so that the internal valve seats I therein face upwardly and may be reached for grinding by lowering the spindle portions of th grinding means down into the respective cylinders of the block, a grinding unit being provided for each cylinder should the block be of the multiple cylinder type. Each cylinder is provided with the customary valve stem guide 8 below and in axial register with the valve seat I, the upper end of such guide being open through the valve seat opening to the interior of the cylinder.

On the front of the frame head 3, for vertical adjustment in suitable ways thereon, is a grinding head carrier I0 of hollow or box form and is horizontally elongated to extend across the head front. The carrier l0 and parts carried thereby are counterbalanced by a weight ll connected by a sheave guided cable [2 to the carrier. Suspended from this carrier are one or more grinding heads or units I3, there being one of such heads for a single type grinding machine, and a number thereof, corresponding to or more than the number of cylinders of an engine block to be ground, if the grinding means is of the multiple spindle type. Each of these grinding heads comprises a pilot stem l4 having a block l5 at its upper end that is mounted in a bearing 16 for limited universal swinging or swivel movements relative to the bottom of the head H] to which it is attached, as shown in Fig. 3. The lower end of the pilot stem 14 projects through and below the grindin means hereinafter described and is adapted to project through-a registering valve seat I and into the associated valve stem guide 8 where it is centered and clamped by a sliding collet H.

The collet I1 (Figs. 9 and 10) is of split sleeve form and is mounted on the taper I8 at the lower end of the stem I4 and when drawn up on such taper expands to effect a firm centering and clamping of the stern l4 within the guide 8. The movement of the collet I1 is controlled by a rod I9 extending centrally up through the stem I4 and into a recess provided in a top extension 2| of the block I5. A coiled expansion spring 22 is mounted in the socket 20 and has its upper end thrust against a head or shoulder on the upper end of the rod and its lower end thrust against the upper end of the stem 14.

The upper end of the rod I9 above the spring 22 is provided with a head 24 that bears upward under the tension of the spring against the peripheral surface of a cam 25. This cam is car.-

ried by a shaft 26 that is journaled in a suitable bearing 21 on the upper end of the top extension 21. A crank arm 23 is. provided at the outer end of the shaft 26 to permit manual operation of the shaft. It is apparent that a turning of the cam to one position will efiect a lowering of the rod and a release of the mullet, while a turning thereof to another position will permit the spring 22 to act to raise the rod and impart a clamping action to the collet. In the case of a plurality of grinding units I3, the several cam arms 28 of the diiferent units are connected together by a bar 29 so that the several rods may be operated in unison to release the associated collets. The stem I4 is shown as having a diametrical enlargement I411, near its lower end to strengthen the stem against lateral bending at a point where desirable.

The grinding unit I3 is carried by the pilot stem I4 for adjusting movements therewith about the center of the universal bearing I6 and is thus suspended with the stem I4 from the carrier II] for universal swinging movements relative to the carrier.

A unit I3 comprises an inner bushing sleeve 30 mounted directly on the stem I4v above the enlargement Ma and having at its lower end an annular radial flange 3I. This sleeve is encircled at its upper end portion by an externally threaded sleeve 32 having near its lower end an annular radial flange 33. The lower end of sleeve 32 projects into the cupped upper end of a rotatably driven sleeve 34 and has its end thrust thereagainst, and the lower end thrust of the sleeve 34 is against the flange 3i on the lower end of the sleeve 30. A jam-nut 35 and lock-nut 36 are threaded on the upper end of the sleeve 30 and exert a downward thrust on the sleeve 32 and an upward thrust on the flange 31 against the lower end of the rotatable sleeve 34. The sleeves 3Q, 32. and 34 are. thus held in assembled relation with the sleeve 34 sufficiently free to turn relative. to the others.

A gear housing 31. is mounted on the sleeve 32, being provided with a top opening through which the sleeve projects and having the lower marginal edge of the opening wall shouldered on the sleeve flange 33 and clamped thereto by a jam-nut 33 on the upper end portion of the sleeve 32. This housin extends to near the lower end of the sleeve 34.

An upper spindle sleeve section 40 is mounted. foreccentric rotation on the lower end portion of the sleeve 34 through the medium of two spaced sets of bearings 4i, the inner races for the bearing balls constituting an eccentric por 4 tion of said sleeve and the upper one of the respective outer race rings having a down thrust on the balls. The upper end of the sleeve section 40 is flanged over the upper race ring of said bearing and is clamped at its lower end to the upper end of a spindle section 42 by a union nut 43. A grinding wheel 44 is threaded or otherwise removabl'y secured to the lower end of the section 42 concentric to its axis of rotation and slightly eccentric to the axis of the pilot stem I4.

A ball bearing 45 is provided for the lower end of the spindle section 42 and the inner race for this bearing is formed by an eccentric bearing sleeve 46 mounted on the pilot stem I4 near its lower end with its axis of rotation concentric to the stem axis. The eccentricity of this sleeve is the same as that of the sleeve 34. The upper end of the sleeve 46 is enlarged and cupped to fit around the stem enlargement I la, and about midway of such enlargement is drivingly connected to the lower end of the rotatable sleeve 34 by an eccentric sleeve section 4?. which is interengaged at 48 to the sleeve 34 and at 49 to the sleeve 46. Interiorly of the sleeve section 41 around the stem enlargement I la are a pair of sleeve sections 50 yieldingly spaced in axial relation by a coiled expansion spring 5|, with the upper end thrust of one section against the lower end of the sleeve 33 and the lower end thrust of the other section against the upper end of the bearin sleeve 45. The sleeve 46 is thus caused to have a yielding downward thrust against the balls of the bearing 45.

The control means for raising and lowerin the grinding wheel 44 and its carrying parts relative to a valve seat I and the pilot stem l4, that is fixedly associated therewith, comprises a control sleeve 53 threaded on the upper end of the sleeve 32 and having an. arm 54 projecting radially therefrom. The upper end of the sleeve 53 is rotatably anchored to a flanged tube '55 and held thereto by a collar 56 that is fixedly secured to the tube by a set-screw 51. The tube is. suinciently thin to be distorted by the pressure of the screw so as to cause the tube to be firmly clamped to the pilot stem M. A coiled expansion spring 58 is disposed between the tube 53 and upper end of the sleeve 30. It is thus apparent that a turning of the control sleeve 53 down on the threaded end of the sleeve 32 will cause 2. raising of the various sleeves mounted around the pilot stem I4 including; the

spindle sections

40 and 42. so as to raise the grindin wheel 44 from the valve seat being ground. Also that a turning of the control sleeve 53. in the opposite direction will permit a lowering of such parts relative to the pilot stem soas to permit a controlled engagement of the grinding wheel with the valve seat. The control arms 54 for the several grindingunits are connected by a bar 60 to cause uniform movementof the several control means, in unison and one of the arms is provided with a handle extension M to. facilitate manual operation of the control; means.

In. valve seat grinders of the eccentric type, such as herein illustrated the grinding wheel 44 and its carrying spindle are driven at high speed, preferably around 10,000 R. P. M., while the eccentric sleeves- 34, 4-1 and. 46 are more slowly driven, say approximately 30- R. P. M., so as to cause the axis of thegrl nding wheel to have an orbital movement around the, axis; of the pilot stem. The eccentric mounting of the wheel relative to the seatcauses the grinding. wheel to have grinding; engagement with the, seat; at one sideot In the present instance, each grinding unit i3 has a flexible drive shaft 62 extending into its housing 37 from a respective motor 53 mounted on the top of the carrier H), and such shaft is in driving connection with a spur gear lid and a worm wheel 65 within the housing. The gear 64 is in direct driving connection with a gear 66 on the upper end of the spindle section it, so as to drive the spindle and its grinding wheel at high speed, while the worm wheel 65 drives a worm 61 on a shaft 88 with a Worm 69 in mesh with a worm wheel ill on the upper end of the eccentric sleeve (Figs. 4 and 5).

In the operation of the machine in the grinding of the valve seats of internal combustion engine cylinders, a cylinder block to be ground is secured in proper position on the work supporting bracket land the carrier ill with its attached parts then lowered to place the grinding wheels in proper relation to the seats to be ground and to insert the lower ends of the pilot stems i l with their attached collets into the registering valve stem guides of the several cylindersn While this is bein done, the crank arms 28 arein proper position to hold the rods l9 and their respective collets in released position. When the lower ends of the pilot stems have been properly positioned in the guides, the crank arms 28 are turned to a position to permit a raising of the rod It and attached collet by the action of the spring 22, so as to cause the collet to firmly engage the guide wall. The engagement of a pilot stem and its collet with a valve guide 8 will cause the stem to automatically adjust itself in centered relation to the associated valve seat to compensate, without binding, for any error in a location of the seat in the casing or relative to the normal axial line of the stem. When an operation of the guidin means has been started, the grinding wheel may be raised or lowered relative to the valve seat, or its feed to the work controlled, by a turning of the control sleeve 53 on the member 32, eifected by movement of the arm 6!. The rotary and orbital movements of the grinding wheel during a grinding operation and their purpose are well understood and therefore need not be further described.

Inasmuch as the axis of the guide 8 and the center of the self-aligning bearing l6 are only theoretically located in registering relation, there some times is a misalignment thereof due to the manufacturing tolerances in the location of the guide 8 or an improper positioning of the cylinder block to be ground. Since the center of the valve seat or part to be ground, for perfect grinding, should coincide with the axial line of the guide and pivotal swinging center of the pilot and since the valve seat center is disposed between said other two fixed centers, it is apparent that a misalignment of the fixed centers will affect the location of the valve seat center in the ratio of the distances A to B shown in Fig. 3. In this ratio, A is the distance between the valve seat center and fixed point of connection of the pilot stem M with the guide 8, and B is the distance between the valve seat center and the center of the pivotal bearing l6. Since this ratio, in the present instance, is approximately one-to-twelve, it is apparent that the ground surface of the valve seat will be concentric with the hole in the valve guide 8 within approximately one-twelfth of the error in the location of such guide. This error will be practically negligible since it is almost universal practice in the industry to locate valve guides within .005 of their theoretical centers.

While I have particularly shown and described the invention for use in connection with the grinding of valve seats in the cylinders of internal combustion engines, it will be understood that it is not restricted to such use but may be used in the grinding of similar seats in other articles, for instance those of Globe valves, and also that the invention is not limited to the particular form and arrangement of the parts shown, as it is capable of many changes within the scope 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 valve seat grinding machine, a head, a hollow pilot stem suspended therefrom for universal swinging movements about a fixed center, said stem being adapted to be projected through a valve seat to be ground and into an associated centering guide of a fixedly supported Work-piece, a collet carried by the outer end of said stem for clamping engagement with the work-piece guide,

means operable through the pilot stem from a point above its upper end to operate the collet to engage and release the guide, a valve seat grinding means carried by the pilot stem and adjustable lengthwise thereof to have grinding engagement with the valve seat of the engaged workpiece.

2. In a valve seat grinding machine, a head, a hollow pilot stem suspended from the head for universal swinging movements about a fixed point and for projection at its outer end through a valve seat and into a centering guide of a workpiece fixedly mounted below the head, a guide engaging collet at the outer end of the pilot stem, an operating rod for the collet extending therefrom lengthwise through the stem and above its swinging center, a spring acting on the upper end of said rod to normally hold it in raised collet-engaging position, and means manually operable to engage the upper end of the rod and move it downward to collet-releasing position against the tension of said spring, and valve seat grinding means carried by the pilot and guided thereby to have valve seat grinding coaction with the valve seat of an engaged work-piece.

3. In a valve seat grinding machine, a head, a pilot stem suspended from said head for universal swinging adjustment relative thereto about a fixed center and having its outer end adapted for projection centrally through a valve seat to be ground and into a centering guide of a workpiece supported in fixed relation below said head, means operable through the pilot stem from above its point of suspension to fixedly hold the stem to the work-piece guide at a point a short distance below the valve seat to be ground, and a valve seat grinding unit carried by said pilot stem for grinding engagement with a valve seat with which the stem is centered, the distance between the valve seat and swinging center point of the pilot stem being many times greater than the distance between the valve seat and the point of engagement of the pilot stem with the work-piece guide.

4. In a valve seat grinding machine, a head, a pilot stem suspended from said head for universal swinging adjustment relative thereto about a fixed center and having its. outer end adapted for projection through a valve seat. to be ground and into. a centering guide of. a work-piece supported in fixed relation below said head, a gear housing mounted on the stem in encircling; relation thereto and below said swinging point, a spindle suspended from said housing in: encircling relation to the stem, a. valve seat grinding wheel carried by the spindle at its. outer end, and gearing? in said housing for driving said spindle from a power source.

5. In a. valve seat grinding machine. a head, a pilot stem suspended from said head for universal swinging adjustment. relative thereto about. a fixed center and having its outer end adapted; for projection through a valve, seat. to.- be ground and into a centering guide of a work-piece supported in fixed relation below said head, a gear housing mounted on the stem in encircling relation there.- to and below said swinging point, an inner spindle mounted on said stem and projectingfrom the outer end of said housing and having its axis eccentric to that of the stem, an outer spindle projecting fromv the outer endof said housing around said inner spindle in concentric relation thereto, a grinding wheel carried by said outer spindle, and a gearing in said housing for driving; said inner and outer spindles at different speeds from a common source.

6. In a valve seat grinding machine, a, head, a plurality of hollow pilot stemsv suspended there..- from for universal swinging movements about re spective fixed centers, said stems being adapted to be projected through respective. valve seats to be ground and into an associated centering guidev of a. fixedly supported work-piece, a collet carried by the outer end of each stem for clamping engagement with the respective work-piece guide, means operable through each, pilot stem. from a point above its upper end to operate: the. collet to engage and release the guide,v a common control. means connected to each of said means for operating it to engage. and release respective guides, and a. valve seat grinding means. carried by each pilot stem and adjustable lengthwise thereof to have grinding engagement with the respective valve seat; of the; engaged work-piece.

7. In a valve seat grinding machine, a head, a plurality of hollowpilot. stems suspendedfrom the head for universal swinging movements about respeotive fixedv points and for projection at their outer ends through respective valve seats and into an associated centering guide of a work-piece fixedly mounted below the head, a guide. engaging collet at the outer end of each pilot stem, an operating rod for each collet extending therefrom lengthwise through the respective stem and above its swinging center, means acting on each rod to normally hold it in raised collet engaging position, and means manually operable to engage the upper end of each rod and move it downward to collet releasing position against the tension of said first means, and valve seat grinding means carried by each pilot. and guided thereby to have valve seat grinding coaction with the respective valve seat of an engaged work-piece.

ROBERT S. BEVERLIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 17,313 Davis June 4, 1929 1,591,288 Davis July 6, 1926 1,626,212 Roy Apr. 26, 1927 1,659,228 Williams Feb.,14, 1928 1 ,667,918 Willis May 1,1928 1,693,767 Smith Dec. 4,1928 1,725,126 Berg Aug. 20, 1929 1,749,514 Scott Mar. 4, 1930 1,760,493 Hall May 27, 1930 1,877,546 Albee Sept. 13, 19.32 1,924,958 Patterson Aug. 29, 1933 1,933,016 Huse Oct. 31, 1933 1,941,918 Schwakapf Jan. 2, 1934 1,948,792 Lee Feb. 27, 1984 1,972,761 Catching SeptJl, 1934 Certificate of Correction Patent No. 2,466,359. April 5, 1949.

ROBERT S. BEVERLIN It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 1, line 17, after the word cases insert are multiplied;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 6th day of September, A. D. 1949.

THOMAS F. MURPHY,

Assistant Uommz'ssz'oner of Patents.