US1855631A

US1855631A - Lapping machine

Info

Publication number: US1855631A
Application number: US458561A
Authority: US
Inventors: Frank O Hoagland; Arthur L Wilder
Original assignee: Pratt and Whitney Co Inc
Current assignee: Pratt and Whitney Co Inc
Priority date: 1930-05-31
Filing date: 1930-05-31
Publication date: 1932-04-26
Anticipated expiration: 1949-04-26

Description

April 26, 1932.

F. o. HOAGLAND ET AL LAPPING MACHINE Filed May 31, 1930 9 Sheets-Sheet 1 ATTORNEY idfloaylm d INVENTORS AL W'z'Zdcr A ril 26, 1932.' F. 'o. HQAGLAND E1- AL 1,855,631

LAPPING MACHINE Filed May 31, 1930 9 Sheets-Sheet 2 F0. Hoayimzd iNVENTORS AZ. T Vz'lder ATTORNEY April 26, 1932- F. o. HOAGLAND ET AL 1,355,531

' LAPPING MACHINE Filed May 31, 1930 9 sheets-sheet s [a 7 5 [a 72 d RNVENTOR5 Al. Wzldfir" ATTORNEY F. O. HOAGLAND ET AL LAPPING MACHINE A ril 26, 192.2.

Filed May 31, 1930 9 Sheets-Sheet 4 ATTORNEY April 26, 1932. F. o. HOAGLAND ET AL LAPPING MACHINE Filed May 31, 1930 9 Sheets-Sheet 5 w 4 n 3 MM Q v m A ww Q 5 Wm Q Q 1 1 km \w 4 9 mm s l l mm A v 7: 3k 7 WN, Q\ U Hllll I mm mm Q mvamoas AL Wz'lde ATTORNEY A ril 26, 1932.

LAPPING MACHINE Filed May 31, 1930 9 Sheets-Sheet 6 fIINVENTORS 4 land B I? ATTORN EY April 26, 1932. F. o. HOAGLAND ET AL 1,855,631

LAPPING MACHINE Filed May 31, 1930 9 Sheets-Sheet 7 ATTORNEE gggggggg April 26, 1932.

F. O. HOAGLAND ET AL LAPPING MACHINE Filed May 31, 1930 9 Sheets-Sheet 8 yZQ dlNVENTORS Al. Wzlaei M ATTO NEY April 26, 1932. F. o. HOAGLAN'D ET AL 1,855,631

LAPPING MACHINE Filed May 31, 1930 9 Sheets-Sheet 9 I as J ATTOR N EY Patented Apr. 26, 1932 UNITED STATES PATENT OFFICE FRANK O. HOAGLAND, OF WEST HARTFORD, ARTZ HUR L. WILDER, OF WETHERS FIELD, CONNECTICUT, ASSIGNOIRS TO PRATT & WHITNEY COMPANY, OF NEW YORK,

N. Y., A CORPORATION OF NEW JERSEY LAPPING MACHINE Application filed May 31, 1930. Serial m1. s,5e1.

T hisinvention relates to lapping machines and particularly to a machine for lapplng outside conical surfaces of anti-friction bearings by simultaneous engagement therewith of a plurality of lapping members in the form of frustums of cones.

A primary object of the invention is to provide a machine for lapping a conical surface for a predetermined length of time by a plurality of lapping members simultaneously engaging the surface being lapped, the lapping surfaces'of said" lapping members having different surface speeds relative to each other and with the surface of the work blank being lapped. v

A further object of the invention is to provide mechanism for simultaneously actuating the lapping members into and out of contacting relation with the surface being lapped between lapping oper'ationseupon an article.

Another object of the invention is to pro'' vide independent heads for supporting the lapping members, each head having a rotating member and driving connections for its individual lapping member, the heads being disposed about the surface being' lap ed, the article being lapped being prefera ly supported for free rotation upon a vertical axis centrally disposed upon the machine so that each lapping member may rest upon the work blank being lapped with th weight of its head.

' Another object of the invention is to provide means for vertically reciprocating the support for 3216 member being lapped so that the lapping embers will traverse the conical surface being lapped and the lapping opera tion will thereby be spread uniformly over the entire conical surface.

And finally it is an object to provide operating mechanism which will actuate the heuds'for the lapping members and the support for the member being lapped in accor ance with a predetermined sequence and for a predetermined time to completely finish the entire conical surface uniformly to a high precision and polish.

With these and other objects in view, our invention includes the features ofconstruction and operation set forth in the following specification and illustrated in the accompanying drawings. V

In the accompanying drawings annexed hereto and forming a part of this specific'ation, we have shown our invention embodied in a special machine for lapping operation upon the inside conical members of Timken type anti-friction bearings, but it will be understood that the invention can be otherwise embodied and that the drawings are not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawings:

Figure 1 is a plan view of a complete machine illustrating the 'nvention and showing the relationship of he heads carrying the lapping members and the member being lappe Fig. 2 is a front elevation of the complete machine shown in Fig. 1.

Fig. 3 is an elevation of the complete machine taken from the left hand side of the machine as shown in Fig. 2.

Fig. 4 is an elevation in section of the machine showing the mechanism Within a head for rotating one of the lapping members, for mounting the head, and the mechanism for vertically reciprocating the support carrying the member being lapped.

Fig. 5 is a horizontal sectional view within the base of the machine showing the operating mechanism of the machine for oscillating the heads and for reciprocating the support'for the member being lapped.

Fig. dis a plan view in sectionof the head oscillating mechanism.

Fig. 7 is a vertical sectional view of the means for controlling and operating the head oscillating mechanism.

Fig. 8 is a detail view of a portion of the mechanism shown in Fig. 7, the parts thereof being shown in another operative position and fromjanother-angle.

Fig. 9is a vertical sectional view of the driving mechanism for the main cam shaft within the machine base.

Fig. 10 is a detail view of a clutch and brake forming a part of the special cam shaft driving mechanism shown in Fig. 9.

Fig. 11 is a vertical view in section taken upon the line 1111 of Fig. 10; and

Fig. 12 is a vertical sectional view of the clutch mechanism taken upon the line 12-12 of Fig. 10.

In the above mentioned drawings we have shown but one embodiment of the invention which is now deemed preferable, but it is to be understood that changes and modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

Briefly, and in its preferred aspect, our invention may include the following principal parts: First, a base having a vertically movable shaft or other form of member preferably arranged substantially centrally of the base and forming upon its upper end a small horizontal surface upon which the member being lapped is adapted 'to be placed; second, a plurality of heads disposed angularly upon the upper surface of the machine base and adapted to be moved toward and from the axis of the member being lapped, preferably upon oblique planes; third, mechanism for simultaneously moving these heads to their operative and inoperative positions; fourth, lapping members, preferably of conical form, rotatably mounted'upon these heads and adapted to be individually driven by motors or other driving members conveniently disposed within the heads, these lapping members, for a purpose to be presently described, being rotated so,

that their work engaging surfaces have different surface speeds; fifth, means for actuating theheads to move the lapping members toward and from their 0 erative or work contacting positions; sixt mechanism for controlling the movements of the'hcads at stated or predetermined variable eriods of time; and seventh, means for reciprocating the support upon which the member being lapped is supported to traverse the lapping members over the surface being lapped.

Referring more in detail to the figures of the drawings, We provide a machine base 10 having uponits upper surface movable heads 11 preferably movable upon inclined planes, these heads 11 being supported within housings 12. These heads 11 are adapted to be simultaneously moved into and out of opera tive work engaging. positions along oblique planes. Referring first to Fig. 4, it will be seen that the movable supporting heads 11 are pivotal'ly supported upon parallel links 13 adapted to oscillate about axes of horizontally disposed shafts 14 and 15 respectively so that with the shafts 14 and 15 arranged as shown in Fig. 4 a head 11 is moved obliquely downward and upward toward and from the member W being lapped, the angle being dependent upon the relative positions of the two supporting shafts 14 and 15 for each head 11. The means for oscillating one of the shafts 14 to effect movement of the head 11 will presently be described. It will be understood that each head 11 is similarly mounted within a housing 12 and that all of the heads 11 may be simultaneously actuated by one operating mechanism. 4

' lVithin the heads 11, one of which is shown in section in Fig. 4, are mounted electrio motors 34 preferably directly supported upon the under portion of the head 11 and connected to a driving shaft 16 through ap propriate gearing or other driving connections so that the shaft 16 may be driven at any predetermined speed relative to its motor 34. On the end of this shaft 16 extending from the head 11 is mounted a lapping member 17 comprising in the embodiment of the invention illustrated the frustum of a cone. The angle of this frustum is such that when the lapping member 17 is in operative pos tion against the member W bein lapped it will engage the member uniform y along the length of one of its elements.

Each of the housings 12 contains substantially similar mechanism for rotating a lapping member 17 rotatably supported therein and for actuating the head 11 toward and from its operative position against tlfe article W being lapped. The motor speeds, driving connections and sizes of lapping member 17 are so selected, however, in the different housings 12 that the different lapping members 17 rotatably engage the member W being lapped at different surface speeds. This necessitates or induces some slipping between the individual lapping members 17 relative to the member W being lapped. This member Wis rotated by reason of its frictional contact with the lapping members and assumes a speed substantially intermediate the surface speeds of the lapping members. The lapping members 17 are or may be of any preferred or standard construction, preferably of cast iron or other .metal adapted to retain upon its surface an abrasive of semifluid form which may be applied to the lapping members in any pre-.

ferred manner. v

The blank or member W being lapped is shown as one of the inner conical members of a tapered roller type anti-friction bearing, the frustum of the cone to be lapped being on the outer surface thereof. W during the la ping operations rests upon the upper end 0 a vertically mounted shaft 18 also shown in Fig. 4. It is, however, free to adj us't itself laterally uponthis platform or upper end of the vertical shaft 18 so that its surface may be" engaged with uniform or equal pressure by the different lapping members 17.

As the length of the conical surface on the member V preferably will be slightly greater This member in extent than the width or thickness of the work engaging surfaces of the lapping members 17, the support for the blank W is adapted to be given a slight vertical reciprocatory movement, just suflicient to traverse the lap-Q ping members 17 slightly back and forthover the surface being lapped. For this purpose the freely rotating shaft or spindle 18 is mounted within and held against axial movement relative to a vertically slidable supporting sleeve 19. This support 19 is held verticallyupward by a suitable coiled spring 20' and is forced downward by movement of a lever 21, one end of which engages a portion of this vertical support, the opposite end of the lever having a roller 22 engaging with and being actuated by a peripheral cam 23. Rotation of the cam 23 will therefore effect vertical movements of small amounts of the go member WV. The mechanism for rotating the cam to effect these traversing movements will be presently described.

In order to simultaneously actuate the heads 11 so that lapping members 17 thereon will be moved to en age and freely rest against the surface being lapped, the heads 11 have their shafts 14 connected by bevel gears 24, these gears 24being mounted on the ends of the shafts 14 supporting the heads 11 30 so that oscillation thereof will cause movement of the heads 11 simultaneously to operative and inoperative positions.

To effect this oscillatory movement of the shafts and the consequent movement of their 36 heads 11, (see Figs. 6, 7 and 8), a vertically mounted rod 25 is provided having

lugs

26 and 27 outstanding therefrom. These

lugs

26 and 27 are adapted to be engaged by a pin 28 mounted within a member 28 secured to 49 and outstanding from a face of one of the bevel gears 24. The

lugs

26 and 27 are so disposed that they are upon opposite sides of the pin 28. It will be seen from this construction that vertical movements of the rod 25 upward will oscillate the bevel gear 24 on which the pin 28 is mounted. Through the shafts 14 and bevel gears 24, this upward movement of the rod 25 will simultaneously oscillate the heads 11 away from theiropera- 50 tive positions. Vertical movement of the rod 25 downward Will force the shafts 14 and heads 11 in the opposite direction so that their lapping members 17 will be brought down into contact with the blank W being 55 lapped.

In order that the lapping members 17 may lever 29 is pivotally mounted upon a fixed stud 30 within the housing for the bevel gears 24. One end of this lever 29 is engaged by a screw within an extended projection 31 upon the lower lug 26. Downward movement,

therefore, of the rod 25 shortly before the rod reaches its lowermost position causes this lever 29 to be oscillated by engagement with the extension 31 upon the lower lug 26.

By means of a pin 32 outstanding from the upper lug 27 oscillation of lever 29 serves to raise the upper lug 27 slightly against the pressure of a spring 33 disposed above this cal movement of the rod 25 upwardly first permits the

lugs

26 and 27 to again come together under action of the spring 33 and then oscillates the bevel gears 24 and shafts 14 by engagement of the lower lug 26 with the pin 28.

The mechanism for imparting rotation to the cam shaft within the base of the machine, shown in Figs. 5, 9, 10, 11 and 12, by means of which the heads 11 and the shaft 18 are operated. will now be referred to. A motor "35 is drivingly connected to a main shaft 36 on which are mounted two

worms

37 and 38. One worm 37 is keyed permanently to the shaft 36 and the other worm 38 is formed on a sleeve 39 rotatably mounted on the shaft 36 but adapted to be clutched thereto so that the worm 38 will be rotated therewith. The

worms

37 and 38 as shown in Fig. 9 are of opposite helix so that the worm wheels 40 and 41 in mesh respectively with these worms will be rotated in opposite directions.

ed by the worm 37 permanently fixed to the shaft 36, it will be seen that worm Wheel 40 is keyed to the shaft 42 rotatably mounted within the base 10 which drives one of a series of change gears 43. These gears 43 serve to rotate a shaft 44 rotatable within the base 10 having a bevel gear 45 at its opposite or inner end. This bevel gear 45 is in mesh with a pair of oppositely disposed bevel gears 46 freely rotatable upon their axes within a mounting comprising a yoke 47 extending from and rotating with the second worm wheel 41. The oppositely disposed bevel gears 46 are in mesh with a bevel gear 48 upon one end of a shaft 49, the opposite end of which has keyed thereto a bevel gear 50in mesh with a large bevel gear 51' secured upon the main cam shaft 52.

With the worm wheel 41 held against rotary movement the bevel gears 46 are free to rotate upon their own axes but are held againstrevolving so that the cam shaft 52 will be rotated at a slow speed variable at will Referring first to the worm wheel 40 rotata yoke 64 engaging within a groove in the of the rotative motions of the two worm wheels 40 and 41 upon the bevel gear 48 are combined, thus inducing an increased speed upon the cam shaft 52.

To permit or prevent rotation of the second worm wheel 41 to vary the speed of rotation of the bevel gear 48 the following mechanism is provided associated with the sleeve 39 carrying the second Worm 38. This mechanism is shown in Figs. 9, 10,11 and 12. A standard form of frictio 1 clutch 54 is provided as shown in Fig. 9 operated by, sliding movement of a spool 55 on the clutch body member which is keyed to the shaft 36. In the operative or engagedcposition of the clutch 54 the sleeve 39 is rotated with the shaft 36. When the clutch 54 is released the sleeve 39 will be looseiipon the shaft 36 so that the shaft 36 may rotate without rotation of the sleeve 39.

To restrain the sleeve 39 against rotation when the clutch 54 is released, brake members 56 are mounted for firmly engaging the outer cylindrical surface of the sleeve 39. These brake members 56 are pivotally mounted on a fixed stud 57 within the base 10 and are normally forced together toward their engaged positions by a rod 58 and a coiled spring 59 disposed as shown in Fig. 11. To force the members 56 out of frictional engagement from the sleeve 39 a. member 60 is provided upon a slidable shaft or rod 61. The forward end of this member 60 is beveled as shown at 62 in Fig. 12, which portion engages adustable plate members 63 within the brake members 56. Preferably and as shown in Fig. 12-, the slidably mounted member 60 also carries clutch operating spool .55. With the rod 61 in one position the brake members 56 are held away from the sleeve 39 and the spool 55 is in a position to hold the clutch 54. in its engaged position. In the other position of the rod 61 the brake members 56,firml v en' gage the sleeve 39 and the clutch 54 is released. w j

The rod 61 at its outer end has attached thereto a member having a depending extension 71. i This extension 71 is engaged by the forked end of a pivotally mounted horizontal lever 72. The lever 72- oscillates about its pivot 7 3. the axis of which is vertical and preferably formed in the side of the machine base. 7 At the opposite end of the lever 72 is a roller 74 adapted to contact with cam dogs 75 on a-disk 76 secured upon the end of the main cam shaft 52. One of the dogs 75 oscillates the lever- 72 in one direction and 'the other dog 75 oscillates it in the reverse direction. lVith the lever 72 in one position the rod 61 is in a position to hold the friction clutch 54 engaged and the brake members 56 released. In the opposite position of the lever 72 the friction clutch 54 is released and the brake members 56 are engaged. The effect of this oscillation of the lever 72 by the cam dogs 75 is to rotate the cam shaft 52 at two difierent speeds, the speed being dependent upon the position to which the lever 72 and consequently the rod 61 has been oscillated.

On the cam shaft 52 is provided an actuating cam 80 by means of which the IOC 25 for actuating the heads 11 in the manner above described is reciprocated. This rod 25 at its lower end has mounted thereon a roller 81 preferably outstanding laterally from one side. Roller 81 engages within a closed path 83 cut into one face of the cam 80, the form of this path being such that it will effect both the up and the down movements of the rod and therefore actuate the heads 11 positively into and out of their operative positions.

The supporting member for the member being lapped as stated above is in the form of a vertical rod 18 which is raised and with is'a screw 93 secured permanently in position within a portion of the base 10. A worm 94 on the inner end of a horizontal rod 95 meshes with the gear 92 and its outer end has a hand wheel 96 enabling the gear 92 to be manually adjusted vertically upon the fixed screw 93 thus compressing the spring 20 and forcing the sleeve 19 and the shaft 18 upwardly with any predetermined pressure. The pressure of the spring 20 forcing the member W upward is regulated by adjustmentof the gear 92 so that it will exceed the weight of the heads 11 and connected parts upon the work W. The work Wand the sleeve 19 are therefore held in the uppermost position permited by the cam 23.

I driving connections for rotating the spindle 16 and the lapping members 1.7 are so chosen and adjusted inthe different heads 12 that the sun face speed of the work engaging surfaces are materially different but in the same d rection of rotation with respect to thewvork V. The contact of the lapping members 17 with the work W' induces rotation of the work V at a speed different from any ofthc lapping members but approximating an average of the different lapping speeds. The effect of this is to cause lapping action by each of the lapping members 17 upon the work V, thus obtaining a very uniform lapping'a'ction over the surface being lapped.

In operation the motor 34'; and

The heads 11 during the lapping operation rest withtheir own weight against the work W being lapped, and as these heads are of substantially equal weight and have lappingmembers-17 of equal size and similar form, the action upon the work W will be substantially equal by each member 17 The spring 20 is adjusted by means of its hand wheel adjusting means so that it will support the work W in position against the combined weights of the heads 11. It will be understood that the lapping members 17 will have the proper apex angle to properly engage elements thereon w en elements of the surface being lapped. Any means may be employed to supply lapping material to the surfaces of the lapplng members and to place and removework blanks being lapped.

With the proper lapping members 17 mounted on the heads 11 and with a work blank W on the horizontal upper surface of the shaft 18, the motor 35 within the base 10 is startedwhich rotates the cam shaft 52. Rotation of this cam shaft 52 first moves the vertical rod or shaft 25 downward, which actuates the heads 11 so that their lapping members 17 each engage the work blank W.

With the heads 11 moved to their operative positions, continued rotation of the cam shaft 52 oscillates the lever 21 so that the work V is moved slightly upon a vertical axis thus causing the lapping members 17 to traverse completely over the surface of the member W being lapped. Determined by the shape of the cam 23 the traversing movements of the workW maybe widely varied both in number and extent. As soon as the cam shaft 52 has rotated suificiently to complete the traversing movements of the work blank -W and the lapping operation has been completed,

the rod 25 is moved verticallyupward by its cam 80 which through the mechanism described above actuates the heads 11 in a direction to remove them from the work blank W whereupon the blank may be removed and another substituted therefor. For this removal and substitution of work blanks the cam shaft 52 need fit be stopped, ample time being allowed by the shape of the cam oove 83 in cam 80 controlling movements of the heads 11 to permit either mechanically operated or manual removal and replacement of work blanks.

What we claim is:

1. A lap ing machine comprising in combination, aase, a plurality of heads thereon mounted for movement toward and from a work support, rotatable lapping members supported within said heads, a work support, and means to simultaneously rotate saidlapping members at different surface speeds relative to a work blank on said suport when said heads are moved toward the work support to enggge the lapping members with the work blan V 2. A lapping machine comprisin in combination, a base, a plurality of hea s thereon mounted for movement toward and from a work support, rotatable lapping members supported within said heads, a centrally disposed work support movable upon a vertical axis, and means to rotate said lapping members when said heads are moved toward the work support to engage said members with a work blank on said support.

3. A lapping machine comprising in combination, a base, a plurality of heads thereon mounted for movement toward and from a worksupport, a work support comprising a horizontal plane movable upon a vertical axis, rotata 1e lapping members supported within said heads whereby when said heads are moved toward said work support said members rest upon a work blank thereon, and means to rotate said lapping members when said heads are moved toward the work support. 7 v

4. A lapping machine comprising in combination, a base, a plurality of heads thereon mounted for movement toward and from a work support, means to simultaneously move said heads into and out of operative positions, rotatable lapping members supported within said heads, a work support, and individual means within said heads to rotate 'the lapping member thereon, said .lapping members resting upon work blank on said support when said hea s are moved toward said support.

5. A lapping machine comprising in combination, a base, a plurality of heads thereon mounted for movement toward and from a work support, lapping members rotatably mounted on said heads, individual driving means for said lapping members within their mounted for movement toward and from a work support, lapping members rotatably mounted on said heads, means to move said heads simultaneously toward and from their operative positions, means to support a work blank between said heads for engagement with said lapping members, and means to move said blank supporti means when said heads are in their operat1v positions. 2

7. A lapping machine comprising in combination, abase, a plurality of heads thereon mounted for movement toward and from a work support, lapping members rotatably mounted on said heads, means to move said heads simultaneously toward and-from their operative ositions, and means tosupport a work blan freely adjustable between said heads and in engagement with said lapping members.

8. A lapping machine comprising in combination, a base, a plurality of heads thereon mounted for movementtoward and from a work support, lapping members rotatably f mounted on said heads, means to move said heads simultaneously toward and from their operative positions, means to support a work mounted on said heads, driving means 1n each head for the lapping member thereon, whereby said lapping members may be rotated at different speeds, means to move said heads simultaneously toward and from their operative positions, and means to support a work blank between said heads in engagement with said lapping members.

10. A lapping machine comprising in combination, a base, a plurality of heads-there on, a centrally disposed work support, means to move said heads toward and from said work support, lapping members rotatably mounted upon said heads and engaging awork blank on said support when said heads are in their operative positions, and cam operated means to actuate said head's, and'means to move said work support while said heads are in their operative positions.

11. A lap ing machine comprisin in combination, a ase, a plurality of heads thereon, a centrally disposed work support, means to move said heads toward and from said work support, lapping members rotatably mounted upon said heads and engaging a work blank on said support when said heads, are in their 0 erative position, cam means to actuate sai heads,-cai n means to move said work support while said heads are in their operative positions, and a cam shaft mounting said cam means. 12. Alap ing machine comprisin in combination, a ase, a. plurality of hea s thereon, a centrally disposed work support, means to move said heads toward and from said work support, lapping members rotatably mounted upon sai heads and engaging a work blank on said support when said heads are in their 0 erative position, cam means to actuate said heads, cam means to move said work support while said heads are in their operative positions, and means to simultaneously rotate said cam means.

13. A lappingmachine comprisin in com blnation, a base, a plurality of hea s thereon, a centrally disposed work support adapted to support a work blank freely adjustably thereon,-means to move said heads toward and from said work support, lap

with the weight of the heads when said heads are in operative position, cam means to actuate said heads, and cam means to move said work support to traverse the lapping members over the blanks being lapped while said heads are in their operative positions.

14. A lapping machine comprising in combination, a base, a plurality of heads thereon, a'centrally disposed work support, means to move saidheads toward and from said work support, lappin members rotatably mounted upon said heads and engaging against a work blank when said heads are in operative position, means resiliently holding said workblank against said lapping members, and cam means to actuate said heads and cam means to move said work support while said heads are in their operative positions.

In testimony whereof, we afiix our signatures.

FRANK O. HOAGLAND. ARTHUR L. VVILDER.