US1486337A - Method of and machine for making gauges and other articles - Google Patents

Description

Mich 111 192%.; w. E. HOKE METHOD OF AND MACHINE FOR MAKING GAUGES AND OTHER ARTICLES Illlll ll ,llllilllllll lllfk Filed June 28, 1918 I TILE-1Y5- Watented M m 12% E. HOKE, OF ST. LOUIS,

WILLIAM PANY, OF NEW YORK,

MISSOURI, ASSIGNOR T6 PRATT & WHITNEY COM N. Y., A CORPORATION OF NEW JERSEY.

METHOD OF AND MACHTNE FOR MAKING GAUGES AND OTHER. ARTICLES.

Application filed June 28, 1918. Serial No. 242,482.

concern: 1, WILLIAM Home, a residing at the city of St. Louis and State of Missouri, have invented a new and useful Methodof and Machine for Making Gauges and other Articles, of which the following is a specification.

This invention relates to a method of and 1 a machine for lapping gauge blocks or similar articles to produce identical sizes and particularly to produce plane parallel opposite faces separated from each other by an assigned dimension, the method and machine being in some respects similar respectively to the method and machine set forth in my copending application for method of and machine for making gauges and other articles, Serial No. 289.591, filed April 12th, 1919, which application, as to a part of its subject matter, is a continuation of this present application. The present invention relates particularly to a method and machine whereby the sizes or lengths of the blocks are automatically determined by positively limiting the reducing action. In the accompanying drawing 1 have illustrated several embodiments .of the mechanical features of my invention and the preferred way of practicing my improved method, but it will be understood that the drawing is for illustrative purposes only and is not to be construed as defining or limiting the invention, the claims appended to 135 this specification being relied upon for that purpose.

Of the drawing Fig. 1 is a view illustrating the method of and machine for lapping gauge blocks.

Fig. 2 is a plan view illustrating one of the laps, and a part of the disc or spider for moving the gauge blocks between the laps.

Fi 3 is a side elevation to illustrate the relat1ve positions of the laps and the disc or spider for performing the lapping operation by movingthe blocks to be lapped between the lapping surfaces. Fig. 4 is a view showinga form of adjustable limit stop which may Ee sired. J

Fig. 5 is; a view illustrating another form of device for actuating the disc or spider.

Fig.6 is a view showing a number of the finished blocks in assembled relation in be usetl when de-' which they may be measured and compared to determine any error that may exist in the dimensions thereof.

As illustrated the machine includes two laps '1 and 2 of similar size having their adjacent faces 3 and 4 made as nearly fiat as possible. A number of similar blocks are placed between the two laps 1 and 2, these blocks forming a group which may be varied as to arrangement but which is preferably a circular series as shown. While I do not so limit myself I have shown in the drawing blocks A-A having opposite fiat faces. For holding the blocks in proper relationship and for other purposes, as will be presently explained, there is provided a fiat plate or spider 5-preferably having suitable apertures 6 therein adapted to receive the respective blocks. Preferably the apertures 6 are larger than the blocks so as to permit turning or rolling movements between the blocks and the spider.

In order to effect lapping, relative movement is effected between the blocks and the laps, this movement preferably being effected by moving the blocks and holding the laps against any considerable movement. The laps are caused to contact with the blocks with a proper pressure'and while I do not so limit myself this pressure is preferably secured by arranging the parts horizontally, as shown. by a suitable support, such as the legs 7 J and the weight of the top lap is utilized to secure the desired pressure between the laps and the blocks. The top lap is preferably supported entirely by the blocks. If greater pressure is desired, additional weight can obviously be applied to the top lap. The top lap is entirely free as concerns vertical movement and it can adjust itself as to parallelism with the lower lap in accordance with the lengths of the blocks.

The movements of the blocks are preferably such that every part of the outer surface of each block engages every part of the working surface of the corresponding lap which is engaged by the surface of any other block. In this way. all of the blocks are lapped equally. By preference the movement is such that each surface of each block engages the entire surface of the corresponding lap. As illustrated the movement is effected by bodily moving the spider The lower lap 2 is held preferably in a circular path. I prefer to make the laps circular in outline and to pro- 'vide them with circular central openings, as

shown. Inasmuch as the spider is moved bodily in a circular path its center is eccentric of the laps. The degree of eccentricity is preferably such that the blocks at one side of the spider will project outward beyond the outer edges-of the laps, whereas the blocks at the opposite side of the spider will project inward beyond the inner edges of the laps. Thus the laps are prevented from becoming unevenly worn. Simultaneously with the bodily circular movement the spider is preferably given a rotative movement, the blocks thus moving circumferentially around the laps. Preferably the blocks are also given a rotative movement about their own axes in addition to their bodily movements.

The combined bodily and rotative movement of the spider and blocks together with the supplemental rotative or rolling movement of theblocks themselves causes all parts of each block surface to move. past all parts of the corresponding lap surface. At first the laps engage only the longer blocks but later, if the lapping proceeds long enough, the blocks are engaged equally and the combined movement affects all of them in the same way, as before stated, and does not tend to reduce some more than others.

For moving the spider there is preferably provided a central drive shaft 8 having a crank 9 .with a crank pin 10 engaging a central aperture of the spider. When the crank 8 is rotated the spider is moved bodily in a circular path. Suitable means is providedfor preventing the laps from partaking of the movements of the spider. As shown, the bottom lap 2 is held by the legs 7, and the top lap 1 is held by lugs or guides 11 formed on the legs 7 and engaging arms 12 on the lap. Preferably the bottom lap 2 is formed with arms 13 similar to the arms 12, there being three equally spaced arms on each lap. The supporting legs 7 are connected with the arms 13 of the lower lap- 2 and the lugsll on the legs engage the arms 12 on the upper lap 1, the two laps thus being held against relative rotative movement but being free to move vertically and to adjust themselves as to parallelism within reasonable limits. A drill press may conveniently .be utilized for supporting and. operating the parts described. The legs 7 may be connected with the table of the drill press, and the shaft 8 may be the spindle of the drill press.

ll preferably leave the spider 5 entirely free as concerns rotative' movement. the aforesaid rotative or precessional movement taking place automatically. This rotative movement usually is in the same direction as the bodily movement, as for instance openings.

means? the clockwise direction. Several difierent factors may be involved in causing the rotation of the spider. The blocks that are entirely between the laps tend to turn about their axes in the counter-clockwise direction, rolling along the walls of their respective When some of the blocks project beyond the-edges of the laps as shown these blocks may be forced by the pressure of the spider to turn in the clockwise direction. These several turning movements of the 1ndividual blocks affect the spider in ditferent ways and the result. is that it is given a *rotative movement about its axis, which movement as before stated is usually in the clockwise direction. Ordinarily the spider makes a complete revolution for every five or six revolutions, more or less, of the crank.

Approximately equal temperature throughout all parts of the laps and the blocks is desirable during the operation of lapping, although it is not necessary to maintain the temperature at any fixed point. In order.

to maintain all of the parts at equal temperature the mechanism may be submerged in some liquid such, for instance, as water, oil or coal oil. This is preferably accomplished by placing a tub such as 14 in position so that liquid therein will submerge thelapping mechanism.

For limiting the relative approaching movement of the two laps 1 and 2, I provide suitable stop devices between them. As shown in Fig. 3, each of the arms 12 and 13 has a bearing surface in the same plane as the main working surface of the corresponding lap. There are stops 15 positioned between the arms of each pair. Each stop is a block of predetermined length preferably secured to the lower arm 13.

If preferred, screws, 16 as shown in Fig.

4, may be used in lieu of the blocks 15..

shaft 18 journaled eccentrically in a revoluble bushing 19. A rotary motion is imparted to the shaft in any proper manner and at the same time a rotary. motion is imparted to the bushing 19. The movement of the gauge blocks when actuated by this form of device is upon a sort of circular spiral curve. causing the spider or disc to move around between the laps.

The basic principle on which this invention rests and the discovery of which formed the preliminary steps leading thereto. reduced to its simplest form, is that if a startbe made with two surface laps and of equal size.

edea? four pieces of metal. the pieces can be rethem between the two surface laps to act as limit stops or supports while the fourth is passed between the two adjacent surfaces of the laps. By changingthem about, lapping first one and then the other, using the other three as supporting stops all may be reduced to the greatest thickness of the thinnest one and at the same time produce plane parallel surfaces of identical dimension' on them all except the thinnest one. This operation pre-supposes that the two surface laps are perfect planes, which is a condition never obtained in practice. If the imperfection of the surface lap consists of a depression the result will still be to roduce identical size in all four pieces; but if the imperfect-ion consists of a raised spot in the surface it will result in lapping the fourth piece thinner than the other three which are being used as supportin stops,

and sets up a never-ending series 0 reduc tions which can never end in identical size of all four.

If, however, thesame three pieces be used for support stops and any number of other pieces be passed between the same parts of the surface of the laps, these other pieces will be made of identical size and with plane parallel faces, even though the laps were not perfect planes nor the three support stops Assumingthat the stops are of equal size and the lapsperfect planes, all the pieces constituting the work .will be lapped to identical size and with lane parallel faces. The size, however, wi 1 be very slightly thinner than the stops on account of the fact that the workavill continue to lap until no further pressure rests on the work from the upper lap, while the stops will continue to bear upper lap without being reduced in size, since there is no and the laps.

The result therefore of imperfections in the lapping surfaces, stops, adjustments, etc., is to produce greater or less departure in size between the stops andthe work wit identical size or truth of the work. These are the conditions which exist in this machine and which enable it to produce plane parallel surfaces of identical dimension with high accuracy.

Similar results can be produced by ing three or more rectangular pieces previously lapped plane on one side in a row on a surface plate, side by side with their plane sides down, and-lapping their upper surfaces into .a perfect plane; and then tuming each alternate one, end for end, and at the same time transferring them to a corresponding position at the other end of the row, and again lapping theirupper surfaces to a perfect plane, and by repeating this opout affecting the their surfaces.

- axes, and positively the entire weight of the movement between them placeration several times theymay finally be duced to identical .size by using three of made of identical size and with plane parallel opposite faces, with high accuracy.

In accordance with the basic method as outlined, proper blocks 15 are selected or A-A have been reduced to the desiredlength. As already stated, any minor imperfections in the stops or in the adjustments thereof will not affect the identity of size of the blocks A or the accuracy of The length of the blocks maydiflt'er very slightly from the assigned length, but the method is nevertheless sufficiently accurate for most classesof work. When greater precision is desired, use can be made of the method as set forth in my H aforesaid copending application Serial No. 289,591.

As shown in Fig. 6 a number of blocks made at one time may be or stack and compared ard of length. As the blocks are all of the same sizes their errors are added and the total error can be readily observed. This method of measurement is described in detail in my aforesaid copending application Serial No. 289,591.

What I claim and desire ters Patent is 1. The method of reducing a series of similar blocks to identical sizes, the method consisting in arranging the several blocks in a group between two opposed flat laps, causing movement between the entire group of blocks and the laps, callsing the blocks to simultaneously turn aboutindividual limiting the relative apof the laps at a preapart notwithstanding to secure by Letproaching movement determined distance continued movement bet-ween the blocks an the laps.

placed in" a series with a known stand- 2. The method as set forth in claim 1 characterized by the production of parallel fiat end-faces on the blocks.

3. The method as set forth in claim 1 characterized by the production of parallel fiat end faces on the blocks and by the turning of the blocks about axes perpendicular to the surfaces of the laps.

4-. The method as set characterized by the production flat end faces on the blocks and by the turning of the blocks about axes perpendicular to the surfaces of the laps and further characterized by a relative bodily movement between the entire group of blocks and the laps in a circular path.

5. The method of reducing a series of similar blocks to identical sizes, which consists in closely arranging tween two opposed flat laps in a group of which the several blocks-are individually and freely movable with reference to the forth in claim 1 of parallel the several blocks belaps, one of said laps being free to relatively adjust itself as to parallelism with the other laps in accordance with the sizes of the blocks, causing such movement between the blocks and the laps that every part of the 6. The method of reducing a series of similar blocks to identical sizes, which consists in arranging the several blocks in a circular series between two opposed flat laps, permitting the said laps to automatically adjust themselves as to parallelism in accordance with the sizes of the blocks, causing rotative movement between the entire series of blocks and the laps parallelly with the working surfaces and about the center of the series, causing the entire series of blocks to move bodily in a. circular path.

about a center eccentric of the center of the series, and positively limiting the relative approaching movement of the laps at a predetermined distance apart notwithstanding continued movement between the blocks and the laps.

7. The method as set forth. in claim 6 characterized by the production of parallel flat end urfaces on the blocks.

8. The method of reducing a series of similar blocks to identical sizes, which consists in arrangingthe several blocks in a definite group between two opposed flat laps, permitting the laps to adjust themselves as to parallelism in accordance with the sizes of the blocks, causing movement between the blocks and the laps to effect lap-ping, positively limiting the relative approaching access? ing surfaces, one of the laps being free to relatively adjust itself as to parallelism, with the other a spider positioned between the laps and having openings therein for blocks to be lapped, means for effecting relative bodily movement between the spider and the laps, and means supplemental to the blocks for positively limiting the relative approaching movement of the laps.

claim 10 in which the limiting means comprises three triangular arranged stops.

12. A lapping machine as set forth in claim 10 in which the limiting means comprises three triangularly arranged tops and in which the stops are independently adjustable.

13. The method of reducing a number of similar blocks to produce parallel flat end faces and identical lengths, which consists in placing the several blocks with one end face of-each in engagement with a fiatisurface plate, placing a flat lap in engagement with the opposite end faces of the blocks, simultaneously lapping the upper surfaces of all of the gauge blockstoa perfect plane, interchanging-some of the blocks on the surface plate to symmetrically distribute variations in length, and repeating the lapping operation.

14;, The'method of reducing a number of similar blocks to produce parallel flat end faces and identical lengths, which consists in placing the several blocks with one end 11. A lapping machine as set'forth in face of each in engagement with a flat surface plate, placing a flat lap in engagement with the opposite end faces of the blocks,

simultaneously lapping the upper surfaces of all of the gauge blocks to a perfect plane, reversing the blocks end for end and again placing them in engagement with the surface plate, again placing the lap in engagement with the blocks and simultaneously lapping the upper surfaces of all of the gauge blocks to a perfect plane, interchanging some of the blocks on the surface plate to symmetrically distribute variations in length and repeatingthe lapping operation. wrnnran n. HQKE.

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