US1316506A - fitter - Google Patents

Description

w. c. PITTE R. MACHINE FOR GRINDING AND LAIFING SLIP AND GAP GAGES AND THE LIKE. APPLICATION FILED FEB-5.19IL

1 ,8 1 6,506, v PatentedS ept. 16, 1919.

4 SHEETS-SHEET I.

5 a. L? i it],

'w. c. PITTER. I MACHINE FOR GRINDING AND LAPPING SHP AND GAP GAGES AND THE- LIKE.

- APPLICATION FILED FEB- 5.191].

1,316,506. Patented Sept. 16,1919.

4 SHEETS-SHEET 2.

I 3 A A if A I W. C. PITTEII.

MACHINE FORISRINDING AND LAPPING SLIP'AND GAP GAGES AND THE LIKE.

APPLICATION FILED FEB. 5.1911.

Patented Sept. 16, 1919.

4 SHEETS-SHEET 3.

'THI: COLUMBIA I'LANOGRAPHI 00-, WASHINGTON. Ix C.

W. C. PITTER. MACHINE FOR GRINDING AND LAPPING SLIP AND GAP GAGES AND THE LIKE.

APPLICATION FILED FEB. 5.1!!!!v Patented Sept. 16, 1919.

4 SHEETS-SHEET 4.

Ewe r2 for Wa 6&4

. UNITED STATES PATENT OFFICE.

WALTER CHARLES PITTE-R, OF LONDON, ENGLAND.

MACHINE FOR GRINDING AND LAPPING SLIP AND GAP GAGES AND THELIKE'. I

Specification of Letters Patent.

Patented Sept. 16, 1919.

Application filed February 5. 1917. seriarno. 146.824.

To all whom it may concern 2 Be it known that I, WALTER CHARLES Prr- TER, a subject of the King of Great Britain, and a resident of London, England, have invented certain new and useful Improve ments in Machines for Grinding and Lapping Slip and Gap Gages and the like, of which the following is a specification.

This invention relates to an improved machine for grinding and lapping slip and gap gages and the like, and has reference particularly to machines of that general type wherein the grinding or polishing member is given a compound movement such as a combined rotary and reciprocatory movement.

The object of the .present invention is to make it possible to finish grinding and lapping slip and gap gages, and other such narrow flatsurfaces, to a fine degree of accuracy by machine, in a more or less automatic manner, in a fraction of the time at present occupied by hand.

The invention consists broadly of a machine having a combination, means for holding the workin operative relation with the laps or grinding surfaces which extend completely across one dimension of the work, and means for imparting to the laps a compound movement such as will insure the laps passing completely over the whole surface being treated at each complete move ment.

A feature of the invention which'is of importance is the provision of a magnetic chuck for holding the work so arranged that the work can be inserted in position and a switching on of the current will result in the firm gripping of the work in the chuck and also the firm adhesion of the chuck-to the bed of the machine.

A further feature resides in the provision progressive movement so that in effect a polnt on the lap or laps inscribes a series of progressive curves and loops in both a forward and rearward direction, which is closely approxim ting to the movement made by a man when lapping by hand, or a backward and forward movement comblned with a side to side movement of the 'la' which gives a zig-zagpath may be provided for.

In order that the inventionmay be more readily understood and carried into practice reference is hereby made to'the accompanying drawings wherein Flgure 1 is a side elevation of amachine designed for gap gages.

Fig. 2 is a plan ofFig. 1.

Fig. 8 is a detail view showing a lap support modified for particular use.

Fig. 4 is an enlarged view of adjustable strips or guides.

Fig, 5 is a detail of the eccentric device in front and side elevation. V

Fig. dis a detail of-parallel strips.

Fig. 7 is a front elevational view of a machine designed for slipgages.

Fig. 8 is a plan of Fi 7.

Fig. 9 is an end elevation of Fig. 7.

Fig. 10 is a detail perspective view of the la s engaging the Work.

eferring to the drawings, and more particularly to Figs. 1' 1306 inclusive the numorals land 2 designate a pair of hardened strips or guides between which the laps 3 .and 4 work. The gage, or work, 5 'to be operated upon is held by means of a magnetic chuck 6 at aposition between the said strips or guides,

The laps 3 and it consisting of strips of metal, or other material, are mounted at each end on spindles 7 and 8, and aremain-- tained pressed against'the hardened guides 1 and 2 by means ofsprings 9 and 10. If

desired a further spring may be introduced between the laps at thelr center, in order to counteract any tendency to flexibility.

The two shafts or spindles 7 and 8 are each secured at each end by means-of suitable thimbles or open ended ferrules 11 to eccentric pins 12, carried by circular rotatable disks 13 mounted on slides 14 as shown in'Figs. 1 ends. Provision is made for varying the eccentricity ofthe pins 12, and consequently the rotary movement of the rods 7 and 8, and :for' this purpose the disks 13 are slotted" at '15; asJshoWn in Fig. 5;

and in order that the positions of the four pins 12 may exactly correspond a scale 16 is attached to each slot 15 and a gage mark to each pin 12. The slides 14 work in guides 17 and each carries two sprocket wheels 18 and 19 which are mounted on the same shafts as the disks 13, so that rotation of the sprocket wheels 18 and 19 will impart c1rcular motion to the laps 3 and a through the medium of the pins 12 and the spindles 7 and 8. The spindles of the sprocket wheels 18 are each connected by means of a connecting rod 20 to an eccentric pin 21 carried by a disk 22 mounted on a driven shaft 28. A driven shaft 24 carries a sprocket wheel 25 coupled to the sprocket wheel 26 on the shaft 23 by means of an endless chain 27; and a wheel 28 is coupled to a wheel 29 on the driving shaft 30 by means of an endless chain 31. The shaft 30 also carries a sprocket wheel 32, and an endless chain 33 couples this wheel to the wheels 18 and 19. The shaft 30 is driven by means of belt gear ing on the pulley 3 1. The structure is mounted on a base plate 35 supported on uprights 36. The guides 17 are carried on the ends of vertical members 37 which are slotted at their centers as at 38 in order that they may accommodate, and be adjusted on, pins 39 projecting from the base plate 35, thus permitting the vertical height of the laps 3 and 1 to be varied at will.

Members 40 fixed to the base plate are provided, as shown particularly in Fig. 1, to serve as guides for the adjustable members 37 which are provided with index lines to register with scales 40* carried by the members 10. The shaft 30 is'journaled in the lower ends of the members 37 so that the coupled wheels 18, 19 and 32 rise in unison when adjusted. Members ll similar to the members 37 carry the shafts 23 and 2 1, and these members work in guides 42 exactly similar to the guides 40, so that accurate vertical adjustment can be made to the laps and their driving mechanism.

The magnetic chuck I prefer to use for holding gap gages consists of two separate units 13 and 44:, each h.ving a coil wound on it, and preferably provided with a spring or springs, as indicated at 45 to bring thesides loosely together, so that when the gage, or other work is placed between them and the current switched on, the two units and the work become one horse shoe magnet, and thus the work and the chuck are firmly held down to the table, or base plate 35.

The hardened strips 1 and 2 are fixed to guides 4:6 which are shown adjustable by means of slots and pins 47 and 48 but which may be adjusted in any known manner such, for instance, as by means of screws. The table, or base plate, 35 is provided with an upstanding member 49 having a true edge to which the true edge of the guides 46 are held up, thus assuring the parallelism of the guides and the laps. The hardened strips 1 and 2 may be made adjustable as shown in Fig. 4:, where each strip comprises two wedge shaped members 1 and 1 having a screw adjustment 1.

A quick means is provided for removing the laps from the work for purposes of inspection, and when the thimble device 11 aforesaid is employed, the thimble can be moved from coupling position from one of the rods 7 or 8 and the other then becomes a hinge about which the laps can be lifted out of the way.

If it is desired to use the machine to lap the ends of slip gages, the laps 3 and 1 are mounted on the spindles 7 and 8 in the manner shown in Fig. 3. Two springs 50 and 51 are used, one on the outside of each lap and distance pieces in the form of sliding collars 52 and 53 keep them in compression, and in this case the guide will be placed between the laps.

Adjustable parallel slips 53 and 5&1 may be used to set the work correctly in the chuck, in line with the guides. These parallels are set to the size of the work to be lapped, the gap gage would be forced on the center, the parallels then are set up to one pair of guides, and the other pair of guides brought up to it and, fastened, then the work and guides are all in correct relation to one another. Then by bringing the chuck up to the work and switching on the current, the work is held in place.

It will be clear from the connections and gearing described that a combined circular motion is imparted to the laps which is similar to the movement used in lapping by hand, and imparts a very accurate and finely finished surface to the work.

When it is desired to lap a great number s of thin slips at the same time, and when only one side can be done at a time, I may employ what I call a single or modification. This modification of the machine has only two fixed guides, that is one at each side of the machine with the lap resting on them, the chuck in this case being raised or lowered to suit the different thickness of slips being operated on, the said chuck having a long straight edge attached for accurate setting of the chuck in relation to the guides. A machine embodying these features is illus trated in Figs. 7, 8 and 9, wherein the numeral 55 designates the main body of the machine. The magnetic chuck 56 is a single member provided with a long straight edge 57, and a bolt, or projection 58, adapted to slide in a slot 59 in the main standard 55 and be secured in any position therein by means of a nut 60. The work 61 is placedon the face of the chuck and is magnetically bound thereto when the current is switched on. r

63 and 64, and the long straight edge 57 of the chuck is positioned parallel thereto by micrometer gages. The guides 63 and 64: are relatively far apart so that any slight inaccuracy of the setting will be quite inappreciable over the area of the work.

Two pins 65 each carried eccentrically on disks 66 cooperate with, or are secured to the lap. The disks 66 are carried on the underside of the slide 67, and concentric with each disk, but carried on the other side of the slide is a sprocket wheel 68. There are two other sprocket wheels on the upper side of the slide and all four wheels 68 are coupled by means of an endless chain 69 driven by a sprocket wheel 70. The wheel 70 is mounted on a shaft 71 journaled in brackets carried by the main member 55 and driven by means of a belt gearing with the pulley 7 2. Thus circular motion is imparted to the lap 62. The slide 67 is provided with slots and bolts 73 and 74, and connect-' ed by means of a rod 75 with an eccentric pin carried by a disk 76 rotating on the spindle 77, which is driven by means of a belt and pulley 78. Thus reciprocating movement is imparted to the lap 62. In this case the motion of the lap will be slightly difierent from that described in relation to Figs. 1 and 2, as a lost motion will occur during one direction of movement of the slide owing to the fact that the rotation of the wheels 68 and 71 are always in the same direction, and it will be clear that for one direction of the running the reciprocating motion aids the rotary motion, and for the other direction retards it so that there will be a lost motion for one direction of operation. This fact however is in no way detrimental to the efiiciency of the machine and the lapped surface is in every way equal to that obtained from the motion described in relation to Figs. 1 and 2. p

In 'place of the chain gearing described I may use bevel or other gearing designed to insure the desired operation.

It will be appreciated that this machine can be used for truing narrow surface plates and other surfaces of a like nature, and by using files in place of the laps it can be used as a filing machine for soft work.

\Vhat I claim and desire to secure by Letters Patent is 1. An improved machine for grinding and lapping gap and slip gages and other such narrow flat objects, comprising in combina tion, means for holding the work in operative relation to the laps, a bodily movable lap carrying structure, laps carried by said structure and extending at all times completely across one dimension of the work, means for moving the lap carrying structure bodily and means for imparting a further movement to the laps relative to their carrying structure such as will insure the laps passing over the whole surface of the work at each of the movements of the laps relative to the lap carrying structure.

-2. In a grinding and lapping machine, the combination of a bodily movable lap carrying structure, laps carried by said structure and extending at all times completely across one dimension of the work, means moving the lap carrying structure bodily, means for imparting a further movement to the laps relative to their carrying structure such as will insure the laps passing over the whole surface of the work at each of the movements of the laps relative to the lap carrying structure, and means for holding the work stationary relative to the lap comprising a magnetic chuck which, upon energization, grips the work and is simultaneously held to the bed of the machine.

3. In a grinding and lapping machine, the combination of a bodily mova ble lap carrying structure, laps carried by said structure and extending at all times completely across one dimension of the work, rods, crank pins, means for detachably connecting said rods and crank pins comprising sliding ferrules or thimbles, and laps mounted upon said rods, means moving the lap carrying structure bodily, means for imparting a further movement to the laps relative to their carrying structure such as will insure the laps passing over the whole surface of the work at each of the movements of the laps relative to the lap carrying structure, and means for holding the work sta tionary relative to the lap comprising a magnetic chuck which, upon energization, grips the work and is simultaneously held to the bed of the machine.

4. In a grinding and lapping machine, the combination of a bodily movable lap carrying structure, laps carried by said structure and extending at all times completely across one dimension of the work, means moving the lap carrying structure bodily, adjustable guides for said laps formed with hardened faces to which the laps work, means for imparting a further movement to the laps relative to their carrying structure such as will insure the laps passing over the whole surface of the work at each of the movements of the laps relative to the lap carrying structure, and means for holding the work stationary relative to the lap comprising a magnetic chuck which, upon energization, grips the work and is simultaneously held to the bed of the machine.

In testimony whereof I aflix my signature.

WALTER CHARLES PITTER.

cm" 0! thll patent may be obtained for five cents each, by addressing the "Gommissioner of Patent! Washington, D. G.

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