US2262725A - Lapping machine - Google Patents

Description

2 Sheets-Sheet 1 H. S. INDGE LAPPING MACHINE Filed Feb. 14, 1940 Nov. 1 1, 1941.

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Patented Nov. 11, 1941 UNITED STATES PATENT OFFICE LAPPING MACHINE Herbert s. Indge, Westboro, Mass assignor to Norton Company, Worcester, Mass., acorporation of Massachusetts Application February 14, 1940, Serial No. 318,739

3 Claims.

-A further object of the invention is to provide an improved driving mechanism for the lower lapping element and work carrying cage. Another object of the invention is to provide the improved lap and cage driving mechanism with means to prevent dust and grit from getting into the mechanism. A further object of the invention is to provide adequate dust and lubricant seals to prevent the admission of dust and grit to the driving mechanism. A further object of the invention is to provide a self-contained lubricant system whereby the chamber surrounding the cage driving mechanism is maintained full of lubricant under pressure. 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 the various. possible embodiments of the mechanical features of this invention,

Fig. 1 is a side elevation of the improved lapping machine, having parts broken away to more clearly show the construction; and

Fig. 2 is -a fragmentary sectional view on an enlarged scale, taken approximately'on the line 2-2 of Fig. 1. I

Referring more particularly to the embodiment illustrated, the lapping machine may be constructed in its general aspects similar to the lapping machine illustrated in my prior U. S. Patent No. 2,103,984 dated December 28, 1937. This machine, as illustrated, may comprise a base III which rotatably supports a lower lapping wheel The base III is provided with an upwardly extending column |2 having an outwardly extending horizontal portion l3 which rotatably supports a vertical spindle M. The spindle l4 carries a rotatable lapping wheel I5 which is connected to the lower end of the rotatable spindle l4 by means of a supporting plate It.

Power may be obtained from any suitable source, such as an overhead drive shaft or an electric motor mounted on the machine. For

the sake of illustration, a belt drive has been shown comprising a driving belt 20 which serves to rotate a pulley 2|. The inner portion of the pulley 2| is formed as one part of a cone clutch. A slidably mounted cone clutch member 22 serves to mate with the clutch face within the pulley 2| to transmit a rotary motion to a rotatably mounted drive shaft 23 which is journalled in . suitable bearings 24, 23, 26 and 21 'in the base It. The clutch member 22 is slidably keyed to the shaft 23. When the clutch member 22 is in the full line position (Fig. 1), no power is transmitted to the shaft 23. When it is desired to rotate the shaft 23, the cone clutch member 22 is moved toward the right (Fig. 1) into engagement with the cone clutch member within the pulley 2| so as to cause rotation of the shaft 23.

In order that the clutch may be readily actuated from an operating position adjacent to the front of the machine, a pivotally mounted control lever 23 is supported on a stud 23 on the base ID of the machine. The lower end of the lever 28 is connected by a stud 3|! with a link: 3| The link 3| is in turn connected by a stud 32 with the forward end of a slidably mounted rod 33. The rod 33 is :lournalled in bearings 34 and 35 which are fixedly mounted on the base ID of the machine. The rod 30 supports a vertically extending arm 36 which is yoke-shaped at its upper end and engages a groove 31 formed integral with the clutch member 22. By movement of the control lever 28 in a counterclockwise direction (Fig. l), the clutch member 22 may be thrown into engagement with the clutch member formed within the pulley 2| to cause rotation of the shaft 23. An arrow point 31a projecting from the yoked portion of the arm 33 cooperates with a spring-pressed plunger 33 to maintain the clutch member 22 either in or out of engagement with the clutch member formed within the pulley 2|. Similarly, when the lever 28 is moved in a clockwise direction into the position illustrated in Fig. 1, the clutch member 22 is disengaged, thus stopping the rotation of The shaft 44 is preferably a telescopic shaft and is they revolve.

on each of the studs 32 in such a position as toconnected at its end by a universal Joint 45 with the lower end of a rotatable shaft 40 which the column I2. The shaft 40 is provided with a multiple V-groove pulley 50 which is connected by multiple V -belts 5i with a multiple V-groove 3,202,? I I I the sears rotate. A cover-plate a encloses the 1 is supported in suitable bearings, not shown, in a bracket-43 which isadjustably mounted on top of pulley slidably keyed to'rotate the vertical spindle I4. -When' the j clutchmember 22 is thrown into engagement, a rotary motion is transmittedthroua'h the mechanism above described to rotate the pulley 50 which transmits a rotary motion through the V-belts II to the pulley 52 to rotate the vertical spindle l4 and. thereby rotate the upper lapping wheel It as desired.

The lower lapping wheel II is connected by a rotatable spider 55 to th upper end of a vertically arranged rotatable sleeve 56. The spider 55 is keyed by means of a key 51 so as to rotate with the sleeve 56 in a manner to be hereinafter described. The sleeve 56 is journalled in bearshaft23 is rotated, a rotary motion is trans-,

mitted through the worm 52 and the worm gear to rotate the sleeve 56 and thereby rotate the spider 55 and the lower lapping wheel II.

The sleeve 56 also supports a gear 63 which meshes with a gear 64 mounted adjacent to the lower end of a rotatable shaft 55. The shaft 55 also carries a small gear or pinion ,66 at its lower end which meshes with a gear 61 which is keyed to the lower end of a rotatable shaft 50. The shaft 68 is rotatably'supported in suitable bearings is and 10 which are supported within the sleeve 56. The shaft 08 servesas a driving means for a work. supporting cage I2 which is provided with a plurality of work receiving apertures to simultaneouslysupport a plurality of work pieces 13 for a lapping operation between the opposed rotatable lapping wheels II and IS. A head 15 is keyed to the upper end of the shaft 63 so as to rotate therewith. The head I serves as a support for a'plurality of studs I6, preferably three symmetrically arranged studs, only one of which is illustrated in Fig. 2. These studs I6 are equally spaced from each other and are equidistant from the spindle 63 about which they revolve. Upon each one of the three studs 16 is rotatably mounted a gear Tl. The gears 11 are arranged to continuously mesh with an internal ring gear. 18 which is fixedly mounted within the spider member 55. Agear 19 is formed integral with or fixedly mounted relative to each of the gears TI. The gears I9 are arranged to continuously mesh with a gear 80 which is rotatably supported by an antifriction bearing 3| on the upper end of the shaft 63.

Three other studs 32 (only one of which has i been illustrated in Fig. 2 are fixedly supported bythe head 15 equi-distant from each other and also equi-distantfrom the shaft 63 about which A gear 33 is rotatably mounted be continuously in mesh with a pinion 34 which is either formed integral with or fixedly mounted to rotate with the gear". A casing 35 is formed as an integral part of j I the spider 55 and serves as a casing or container which surrounds the gear cage driving mechanism and serves as a lubricant containerin which upper open end of the casing II. A pair-of dust and lubricant packing rings "and 03 are provided to prevent lubricant leaking from the. casing 35 and also to-prevent dust. from-entering within said casing and thus coming in-Lcontsct with the moving parts. A cap." is fastened by screws 0| to the hub of each of the three gears 03 so that it will rotate concentric therewith.

Each of'the caps00 serves as a support for a" I work cage supporting and driving pin 32. The

driving pin 32 may be fixedly mounted relative to the cap 30 or may be adjusted relative thereto to varythe amount of motion transmitted thereby to the cage 12. Each of the caps 30 is provided with dust and lubricant packing rings 34. Also, packing rings 35 are interposed between the cover plate 36 and the cap 30, thus forming a double seal against. lubricant leakage from the casing 35 or grit passing through into the gear mechanism contained within the casing 35.

When the shaft 2: is rotated, the worm u will transmit a rotary motion through the worm gear 6| to rotate the sleeve 56 andspiderli .to

rotate th lower lapping wheel II. At the same time, the rotation of the sleeve 56 transmits a rotary motion through the gear 6.3, the gear 54, the gear 56, the gear 51, to rotate the shaft 53. Rotation of the shaft 68 serves to rotate the head I5 which in turn transmits a rotary motion through the spaced cage driving pins 32 to rotate the cage I2 during a lapping operation.

The gears 11 rolling in mesh with the stationary ring gear 18' transmit a rotary motion through the gears 19 to the central gear and pinion 04 which in turn transmits a rotary motion to the three gears 83 which simultaneously rotate the caps 30. The cage driving pins 92 are usually arranged ofi center'relative to the axis of rotation. of the caps so. Therefore, any rotary motion of the caps causes a gyrating' movement to be imparted to the cage member 12 during the rotation thereof, thus providing a combined rotary and gyrating movement of the work carrying cage 12 simultaneously to move a plurality of work pieces 13 through an irregular path between the operative faces of the lapping wheels II and I5 simultaneously to lap the opposed faces thereof. I 4

In order to attainone object of the invention, it is desirable to provide a lubricant system whereby the chamber within the casing 35 may at all times be maintained filled with lubricant under pressure so as to prevent the formation of a partial vacuum with the resultant sucking in of grit and other foreign material which would rapidly wear the cage driving parts and bearings therefor. contained lubricant system is. provided comprising a lubricant reservoir 99 formed within the base I0 of th machine. A lubricant pump I00 is formed integral with a cover plate IOI for convenience of assembly. The lubricant pump I00 comprises a reciprocable plunger I02 which supports a roller I03 on a stud I04 which is carried by a bracket I05 fixedly mounted on the end of the plunger I02. An eccentric I00 is mounted on the drive shaft 23 and serves through the roller I03 to transmit a reciprocatory movementto the pump plunger I02 when the shaft 23 J is rotated. A compression spring I01 serves at "alljtimes to maintain the roller I 03 in operative'eng agement with the cam or ec-' centric I05.

Lubricantunderpressure is pumped from the In the preferred form, a selfreservoir 99 through a strainer I08, through a pipe I09, through a ball check valve H0, into a pump chamber I I I. When the plunger I02 reciprocates, fluid is forced under pressure through a bined rotary and gyrating movement is entirely.

surrounded by lubricant under pressure so that all of the moving parts are adequately lubricated. It is desirable to maintain a sufiicient pressure on the lubricant within the chamber H6 to prevent any air pockets or creation of a partial vacuum, so as to prevent dust or foreign matter from working into the chamber H8 by passing the oil and grit seals above described.

In order to maintain a uniform pressure on the lubricant within the chamber H6, an ad- :lustable ball check valve H1 is provided. Lubricant under pressure within the chamber H6 fills a vertically extending passage H8 to the ball check valve H1. The ball check valve I I1 is maintained in a closed position by means of a spring H9, the tension of which may be adiusted by means of a screw I20. By varying the tension of the spring I I9, the pressure of the lubricant within the chamber I I 6 may be varied as desired. When the pump I forces lubricant into the chamber I It to the extent that the pressure rises above the pressure set for the ball check valve I II, the ball I I1 is forced downwardly to allow excess lubricant under pressure to pass through a passage I2I formed in the casing 85.

Lubricant passing through the passage I2I may pass downwardly through an enlargedbore or chamber I22 within the bracket 00 and drains through a passage I23 into the reservoir, within the base I-0. By adjustment of the screw I20, the pressure of the lubricant within the chamber H0 may be readily varied as desired, so that it is sufficient to maintain a full chamber of lubricant and sufllcient to prevent creation of a partial vacuum and thus stop leakage of grit or foreign matter by the lubricant and dust seal rings 81 and 88. In case the passage H8 should become clogged, a second ball check valve I25 is provided which is connected by a short passage with the lower portion of the chamber H8. A screw I26 is provided for adjusting the compression of the spring I21. This ball check valve I2! is adjusted to a slightly higher pressure than the ball check valve I ll so that normally the ball check valve II'I functions to release excess lubricant under pressure. In case of a. stoppage in the passage H8 and a resultant increase in lubricant pressure within the chamber H6, the bail check valve I25 will open and allow lubricant from the lower portion of the chamber I It to pass outwardly through the ball check valve H1 and thereby retum'to the reservoir 89.

The operation of the improved lapping machine will be readily apparent from the foregoing disclosure. 'The reservoir 09 within. the base I0 is filled with lubricant sufficient to maintain a level substantially up to the center of the drive shaft 23, thus providing adequate lubrication for the gear mechanism within the base.

When a lapping operation is started and the control lever is shifted to engage the clutch member 22 to start a rotary motion of the shaft 23, the rotation of the eccentric I06 starts reciprocation of the pump plunger I02 to force lubricant through the central aperture H5 in the shaft 68 to maintain a desired and predetermined lubricant under pressure filling the entire chamber H0 within the casing 85 to adequately lubricate the gears and bearing parts, maintaining a full chamber and thus preventing creation of a partial vacuum and eliminating the danger of dust, grit or foreign material passing the lubricant and dust seals, as above enumerated.

It will thus be seen that there has been pro- ,vided by this invention apparatus in which the various objects hereinabove 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 may be made in the 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, a work carrying cage, means including a gear mechanism to rotate and gyrate said cage, a rotatable casing surrounding said mechanism, a lubricant pump within the base, lubricant connections between said pump and said casing, means to actuate said pump to maintain lubricant under pressure Within said casing, and means including an adjustable relief valve in said casing whereby the lubricant pressure may be varied as desired.

2. In a lapping machine having a base, a rotatable lapping wheel, a work carrying cage, a hollow casing to support said wheel, means including a gear mechanism within said casing to rotate and gyrate said cage, means including a rotatable drive shaft in the base which is operatively connected to rotate said lapping wheel and to actuate said gear mechanism, and a lubricant system within said base including a lubricant reservoir, a lubricant pump, lubricant connections between said pump and easing, driving connections between said shaft and pump, and an adjustable relief valve in said casing whereby said casing may be maintained filled with lubricant under a desired and predetermined pressure.

3. In a lapping machine having a base, arotatable lapping wheel, a work carrying cage, 9.

v hollow casing to support said wheel, means including a gear mechanism within said casing to rotate and gyrate said cage, means including a rotatable drive shaft in the base which is operatively connected to rotate said lapping wheel and to actuate said gear mechanism, and a lubricant system within said base including a lubricant reservoir, a lubricant pump, lubricant connections between said pump and said casing, an adjustable pressure relief valve in said casing, and an eccentric on said drive shaft to actuate said pump whereby lubricant under the desired and predetermined pressure may be maintained in said casing.

HERBERT S. INDGE..

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