US2275061A - Lapping machine - Google Patents

Description

March 3, 1942. H. s. INDGE LAPPING MACHINE 3 Sheets-Sheet 2 Filed Feb. 8, 1939 March 3, 1942.

H. s. INDGE V 2,275,061

LAPPING MACHINE Filed Feb. 8, 1939 :s Shee ts-Sheet s HEBEERTSJNDGE Patented Mar. 35 1942 LAPPIN G MACHINE Herbert S. Indge, Westboro, Mass" alslgnor to Norton Company, Worcester, Mass., a corporation of Massachusetts Application February 8, 1939, Serial No. 255,298

' 3 Claims. (Cl. 51-117) The invention relates to lapping machines, and more particularly to a micro-lapping machine for producing an accurate surface of high quality on either a cylindrical or flat work piece.

One object of the invention is to provide a simple and thoroughly practical lapping machine for producing fine finishes on work pieces. Another obiect of the invention is to provide an im proved lapping machine in which either flat or cylindrical work pieces are lapped between a pair of opposed relatively rotatable lapping elements. A further object of the invention is to provide an improvedlapping machine having a pair of op posed relatively rotatable lapping elements which are relatively revolved to produce a combined rotary and planetary movement of the lapping v element relative to the work piece. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, as will be exemplified in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which is shown one of various possible embodiments of the mechanical features of this invention:

Fig. l is a vertical sectional view-through a niiicro-lapping machine embodying this inven' Fig.2 is a fragmentary plan view of the machine shown in Fig. 1, showing the driving mechanism for the upper lappingelement;

Fig. 3 is a fragmentary sectional view taken approximately on the line 3-3 of Fig. 1, showing the arrangement of the work supporting Fig. 4 is a plan view of the Fig. 3;

Fig. 5 is a modified type of work cage for use in the lapping of flat work pieces;

Fig. 6 is a modified type of cage adapted for supporting cylindrical work;

Fig. 7 is a cross sectional view, showing the support for the cage construction shown in Figs. 5 and 6; and

Fig. 8 is a fragmentary sectional view of a modified drive for the upper lapping wheel.

The improved lapping machine as disclosed in the drawings comprises a base l0 which supports a pair of opposed spaced lapping elements or disks II and I2 which are provided with plane lapping surfaces arranged to engage opposite sides of a work piece to lap the same. The lapwork cage shown in ping element l I is mounted at the lower end'oi' a vertically arranged rotatable spindle II which is rotatably joumalled eccentrically within a rotatable'sleeve ii. The spindle l3 and sleeve are each provided with independent driving mechanisms so that the lapping element or wheel H may be rotated about the axis of the wheel spindle l3 and the sleeve Il may be rotated about its axis of rotation to produce a planetary movement of the wheel spindle I 3 and the lapping wheel or element ll.

Similarly, the lower lapping element or wheel i2 is supported on the upper end of a rotatable spindle I5 which is rotatably and eccentrically joumalled within a rotatable sleeve or quill IS. The spindle l5 and sleeve or quill l6 are each arranged to be independently rotated so as to rotate the lapping element l2 about the axis of its supporting spindle and to move the lapping element in a planetary motion by rotating the sleeve or quill IS.

A driving mechanism is provided for,rotating and revolving the lapping elements. Ayariable speed electric motor 20 is mounted. within the base iii of the machine. Apulley 2| mounted on the end of the motor drive shaft is connected by means of a belt 22 with a pulley 23 which is mounted on the outer end of a rotatableshaft 24.

The shaft 24 is journalled in a bearing 25 in the base ill of the machine. A bevel gear 28 is mounted on the inner end of the shaft 24' and meshes with a bevel gear 21 which is in turn keyed to a vertically arranged rotatable shaft 28. The shaft 28 is journalled within bearings 29 and 30 in the base It).

The lower end of the shaft 28 is provided with a pulley 35 which is connected by means of a belt 38 with alarger diametervpulley 31 which is removably mounted on the lower end of the lap spindle I! so as to rotate the lapping wheel i2. An idler pulley 38 is rotatably mounted on. a stud 38 which is in turn supported by an idler bracket to take up the slack and to properly tension the driving belt 36. The pulleys 35 and 31 may be readily changed to facilitate rotating the lapping element l2 at a desired speed.

The upper lapping element II is similarly rotated either in the same direction or in the opposite direction from the lower lapping element l2. As illustrated in Fig. 1, a driving mechanism has been shown for rotating the lap spindle It and the lap H in the opposite direction from the lap i2. A gear 45 is keyed on the shaft 28.

The gear 45 meshes with a gear 46 which is keyed to a rotatable shaft 41 which is joumalled in a 2 bearing 48 in the base I0. A pulley 49 is removably keyed onto the upper end of the shaft 41 and is connected by means of a driving belt 50.

50 and to tension the same so as to transmit the desired rotary motion 'to the upper lap l I.

If it is desired to rotate the spindle I3 and lap II in the same direction as the spindle I5 and lap l2, a pulley 49a (shown in Fig. 8) may be placed in position on the upper end of the shaft 28 between the idler- brackets 54 and 55 and a belt connected between the pulley 49a and the spindle pulley 5i.

In order to secure the desired and predetermined lapping action, it is desirable to impart a secondary motion to the lapping elements II and Ii. in addition to their rotary motion. In the preferred construction, this movement is a planetary movement whereby the spindle I3 is revolved as it is rotated about the axis of the sleeve or quill l4, and similarly the spindle I5 is revolved as it rotates about the axis of the sleeve or quill IS. The vertical drive shaft 28' is provided with a driving gear 80 which is slidably keyed thereto and is held in adjusted positlon by means of a set screw BI. The gear 60 meshes with a gear 82 which is rotatablysupported on a shaft 63. The shaft 63 is iournalled in bearings 84 and 85 in a projecting portion of the base Ill. The gear 62 meshes with a gear 65 which, as illustrated, is formed by cutting gear teeth in the peripheral surface of the sleeve or quill l4. The gear 65 is a wide faced gear having relatively wide gear teeth to facilitate longitudinal or axial movement of the quill I4. When the shaft 28 is rotated, it serves not only to transmit rotary motion through the belt 58 and pulley 5| to rotate the spindle l3 but also, through the gears 60, 62 and 65, to rotate the may be accomplished by loosening the set screw 1 Si and sliding the gear out of mesh with the gear 66 and then rotating the quill I4 so that the axis of the spindle I3 is on the diametrically opposite side of the axis of the sleeve or quill I4. The gear 6|! may then be moved upwardly. 4

To facilitate loading of work pieces into the machine and also to produce the desired lapping engagement between the laps II and I2 relative to the work, it is desirable to provide means for producing a relative approaching and receding movement between the lapping elements I! and i2. In the construction as illustrated in the drawings, the lapping element II is arranged for movement toward and from the lapping element I2. The sleeve or quill I4 is slidably mounted within the cylindrical aperture 11 of the base III. Manually operable means is provided for producing a relative approaching and receding movement. This niay comprise a man-' ually operable spoked wheel 80 which is mounted on the outer end of a shaft 8| which is journalled in the base III. The shaft 8| carries a gear 82 which meshes with circular rack teeth 83 formed in the periphery of the sle ve I4. By rotation of the wheel 80 in a clock e direction (Fig. 1), the gear 82 acting upon the circular rack 83 will cause the quill l4 to move upwardly, thus separating the upper lap element II. Similarly, the rotation of the wheel 80 in a counterclockwise direction serves to lower the quill l4 and the upper lap element II so that it approaches the lower lap I2 and may be moved into en sleeve or quill I4 to impart a planetary movement to the lapping element II during rotation thereof.

Similarly, a gear 10 is mounted on the drive shaft 28. The gear 10 meshes with a gear 12 which is supported on a rotatable shaft I3. The shaft 13 is joumalled in bearings 14 and I5 in the base Ill. The gear 12 meshes with a gear I! formed on the periphery of the sleeve it. It

will be readily apparent from the foregoing disclosure that when the shaft 28 is rotated, a rotary motion is transmitted by the belt 35 and pulley 8-1 to rotate the spindle I5 and the lappin element II about the axis of the spindle I5, and at the same time the gears 10, I2 and I6 serve to rotate the sleeve or quill I8 so as to' impart a planetary motion to the wheel spindle I5 and lapping element I2 during rotation thereof.

As shown in'Fig. 1 of the drawings, the quills I4 and I8 are timed and positioned so'that the axes of the spindles I 3'and I5, respectively, are in alignment with each other and travel in alignment during the'rotary and planetary movement of the lapping elements II and I2. If desired, 'the quills I4 and It may :be relatively adjusted so that the axes of the spindles I3 and I5 are out of alignment with each other during substantially the entire lapping operation. This gagement with a plurality of work pieces located therebetween. i

To facilitate rotation of the wheel spindle I3 during the vertical movement of the quill I4, the driving pulleys 49, 48a and the idler pulley 52 are preferably wide faced pulleys of a width at least equal to the maximum vertical movement of the quill l4, so that during this vertical positioning movement of. the upper lap II, the

spindle I3 may be continuously driven by the belt 50.

A suitable work holding cage is provided for locating work pieces between the opposed plane faces of the lapping elements II and I2. As illustrated in Figs. 1, 3 and 4, a work cage is provided having a plurality of non-radially extending work locating spindles 9| which serve to support a plurality of hollow cylindrical work pieces 92 thereon. A fixed guiding plate 94 is provided with a cylindrical aperture 95 slightly larger than the outer periphery of the spoked cage 90, 9| with the work pieces mounted thereon so that the cage and work pieces are free to move therewithin. The plate 94 is held in a fixed position by means of a plurality of spaced studs 96, 91, 98 and 99. These studs are screw threaded into a'pan-s'haped member I00 which is fixed relative to the base I II. A pair of nutsare provided on each of the studs 98, 91, 9 8 and 99, one located above and the other below the plate 94. These nuts serve as locating and holding means whereby the plate 94 may be raised or lowered to space it substantially midway between the opposed faces of the lapping wh'eels II and I2. This plate 94 is maintained in fixed relationship relative to the machine base and pieces 92 are placed in position within the aperture 85 and the lapping element II is moved downwardly into engagement with the work pieces 92 while the spindles and 'quills are rotated to produce a rotary and planetary movement of the lapping elements H and I! so as to produce the desired and predetermined lapping operation on the work pieces 92. The work pieces, as illustrated in Figs. 1, 3 and 4, are hol-fl low cylindrical work pieces.

This invention, however, is not limited to cylindrical type work pieces but is equally applicable to solid work pieces of a cylindrical shape as well as fiat work pieces in which it is desired to lap opposed flat faces parallel to each other. Modified cage constructions have been illustrated in Figs. 5, 6 and '7. In Fig. 5 a cage I05 is provided with a plurality of apertures I06 which are arranged to receive circular work pieces I07 having flat opposed hollow surfaces to be lapped. This cage is applicable to any shape of flat work pieces and apertures are provided sufliciently large and preferably shaped as clearance holes,

slightly larger than the shape and size of the work pieces to be lapped.

A similar type work cage III) has been illustrated in Fig. 6 for lapping solid cylindricalwork pieces. Thecage member H9 is provided with a plurality of non-radially arranged slots l I I which are slightly larger than the work pieces 2 to be lapped. Each of the cages I05 and H is provided with a peripheral flange Ill (Fig. 7) which is arranged to rest upon the upper surface of the fixed plate 94 so as to locate the cage I" or H0 between and I2.

The operation of this machine will be readily apparent from the foregoing disclosure. Assuming the various parts to have been previously adjusted and the speed of the motor 20 to have been adjusted by means of a rheostat (not shown) to produce the desired rotary speed to the drive shaft 28, and also assuming that the proper size of pulleys been mounted in position to produce the desired rotary speed to the lapping elements II and I2, themachine is then ready for a lapping operation. The lapping element II is in an upper or raised position and the work cage 90 having a plurality of work pieces 82 carried thereby is placed in position within the aperture 95 of the fixed guide plate 94. The motor 20 is then started to rotate the spindles II and I! and to rotate the quills l4 and IS so as to impart a rotary and planetary movement to the lapping elements II and I2. The upper lapping element is then. moved downwardly by rotation of the the lapping elements II' as, 31, 4a and have II and I2 are rotated and planetarily moved. If additional pressure is desired to increase the cutting action of the lapping wheels ll and II, a pressure device (not shown) may be utilized, such as that shown in my prior U. S. Patent No.

r 1,831,958 dated November 17, 1931.

It will thus be seen that there has been pro- 'vided by this invention apparatus in which the manually operable wheel to move the upper-- lapping element ll into. operative engagement with the work pieces 92. The weight of the upper lap may be positioned to produce the desired lappin action as the lapping elements,

various objectshereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made inthe embodiment above set' forth, it is to be understood that all matter'hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a lapping machine having a base, opposed rotatable lapping elernents supported thereby, means relatively to move said elements toward or from each other, driving means to rotate said elements about one axis, driving means simultaneously and positively to revolve said elements about an axis eccentrically disposed relative to the axis of rotation during rotation thereof, a freely rotatable work cage between said elements, and means including a fixed guide plate having a cylindrical aperture which surrounds said cage to prevent lateral movement thereof.

2. In a lapping machine having a base, opposed rotatable lapping elements supported thereby, means relatively to movesaid elements toward or from each other, means positively to rotate said elements about one axis, driving' means. simultaneously and positively to revolve said elements about an axis eccentrically disposed relative to the axis of rotation during rotationthereof, -a freely rotatable work cage between said elements-means including a fixed guide plate having a cylindrical aperture which surrounds saidcage to prevent lateral movement thereof, and means to adjust the position of said plate.

3. In a lapping machine having a base, opposed rotatable lapping elements and a rotatable work cage therebetween, means to move at least one of said elements relatively toward and from the other, a pair of rotatable spindles to support said elements, a pair of aligned rotatable sleeves rotatably supported in said base, eccentric bearing supports in said sleeve for said spindles, a drive shaft, means including a motor positively to rotate said shaft, driving connections between said shaft and each of said sleeves synchronously to rotate said sleeves, and driving connections between said shaft and each of said spindles synchronously to rotate said spindles.

HERBERT S. INDGE.

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