US3443342A

US3443342A - Lapping machine with automatic loading and unloading means

Info

Publication number: US3443342A
Application number: US535894A
Authority: US
Inventors: Eugene A Schulz
Original assignee: Crane Packing Co
Current assignee: JOHN CRANE HOUDAILLE Inc A CORP OF
Priority date: 1966-03-21
Filing date: 1966-03-21
Publication date: 1969-05-13
Anticipated expiration: 1986-05-13
Also published as: GB1183210A; GB1183209A; DE1652009A1; FR1514850A

Description

y 1969 E. A. SCHULZ 3,443,342

LAPPING MACHINE WITH AUTOMATIC LOADING AND UNLOADING MEANS Filed March 21, 1966 Sheet of 10 "51.5. i. ll

uunI-I-Illllm 89 INVENTOR UGE2I\} A.SCHULZ BY 1m 1 31 ATTY.

E. A. SCHULZ 3,443,342 LAPPING MACHINE WITH AUTOMATIC LOADING AND UNLOADING MEANS May 13, 1969 Sheet )2 of 10 Filed Max ch 21, 1966 A r lnu n INVENTOR EUGENE A SCHULZ E. A. SCHULZ LAPPING MACHINE WITH AUTOMATIC LOADING AND UNLOADING MEANS J of 10 Sheet Filed March 21, 1966 .52 5:2: Ill 4..

INVENTOR EUGENE A. SCHULZ mm mm uh *m mm May 13, 1969' E. A. SCHULZ 3,443,342

LAPPING MACHINE WITH AUTOMATIC LOADING AND UNLOADING MEANS Filed March 21, 1966 Sheet 4 of 10 INVENTOD EUGENE A. SCHUL Z mm f n/0322;521:1- I

E. A. SCHULZ May 13, 1969 LAPPING MACHINE WITH AUTOMATIC LOADING AND UNLOADING MEANS Sheet Filed March 21, 1966 Z RL H m mm d s 7 a: M M q fi hm a W U E m: m= UH um NE QM g E. A. scHuLz LAPPING MACHINE WITH AUTOMATIC LOADING AND UNLOADING' MEANS Filed March 21, 1966 H! mm Sheet 6 of 10 q. 732 Q o) 9 2 'l/l/f M; Q 0 o Q INVENTOQ EUGENE A. SCHULZ 0mm FJ/Wty.

E. A. SCHULZ -May 13, 1969 LAPPING MACHINE WITH AUTOMATIC LOADING AND UNLOADING MEANS Sheet 7 of 10 Filed March 21, 1966 INVENTOR EUGENE A. SCHULZ Ma 13, 1969 E. A. SCHULZ 3,443,342

LAPPING MACHINE WITH AUTOMATIC LOADING AND UNLOADING MEANS Filed March 21, 1966 Sheet 8 of 10 INVENTOIQ EUGENE A. SCHULZ (1mm fl zmmg E. A. SCHULZ 3,443,342

LAPPING MACHINE WITH AUTOMATiIC LOADING ANI5 UNLOADI'NG MEANS May 13, 1969' Sheet of 10 Filed March 21, 1966' INVENTOR EUGENE A. SCHULZ Sheet of 16 E. A. SCHULZ LAPPING MACHINE WITH AUTOMATIC IJOADING AND UNLOADING MEANS May 13, 1969 Filed March 21, 1966 WQN lllll fir g 4% W i -52; m W M EN a 3 a 6m my a WIIIIL L d u h m w w V Nap A 2N Q- @N EN h m: u E NNm n m. WVOI PUG u E m United States Patent 3 443 342 LAPPING MACHINE WITI l AUTOMATIC LOADING AND UNLOADING MEANS Eugene A. Schulz, Niles, Ill., assignor to Crane Pack- US. Cl. 51-131 14 Claims ABSTRACT OF THE DISCLOSURE An automatic loading and unloading mechanism for a flat lapping machine, the latter having a plurality of conditioning rings which serve also to hold the workpieces on the lap. The rings are indexed periodically to a loading station where they are slid off and over an elevator which lowers the finished workpieces from the rings and receives unfinished workpieces from a slide, the latter pushing the finished pieces ofi the elevator before the unfinished pieces are slid thereon. A hopper automatically fills the slide with appropriately arranged and counted workpieces while the lapping machine is finishing workpieces in preparation for sliding the workpieces upon the elevator.

This invention relates to method and apparatus for loading and unloading work-holding rings on surface finishing machines of the type disclosed in US. reissue patent, No. Re. 23,937, to Earl J. Bullard for Lapping Machine.

There is presently commercially available a lapping machine for lapping flat articles which uses an annular lap. The lap is continuously and automatically conditioned by relatively heavy rings which rest upon the lap surface and perform the additional function of holding work pieces at a particular station on the machine, the work pieces for this purpose being placed 'within the rings. Three or more such rings may be used simultaneously, thereby providing three or more work stations on a single lap. Rapid stock removal is achieved by placing a disc-shaped weight or pressure plate into the ring and upon the articles being lapped.

To load or unload a lapping machine of the above description the machine must be stopped, the pressure plate and ring raised from the lap, and the articles then scraped or pushed off the lap as well as off the pressure plate to which they may adhere when the plate is raised. New work pieces to be lapped are then placed on the lap in the area defined by the ring, and the ring and pressure plate are lowered to surround and press upon the work pieces. It may be observed that in a lapping machine of the type described, machine time is lost while the machine is being loaded and unloaded, inasmuch as these functions are performed while the machine is stopped. Furthermore, the loading and unloading are generally done manually, which requires that an attendant be present to unload all stations and then reload all stations with pieces to be lapped.

It is an object of this invention to provide a method of automatically loading and unloading a ring-type work holder on a lap or the like, with a minimum of machine stoppage and manual elfort.

A more specific object of this invention is the provision of a method of loading and unloading a plurality of work-holding rings of a lapping machine from a single station, with means for indexing all of the rings of the machine periodically to bring them successively to the said single station.

Another specific object of this invention is the provision of a method of loading the rings of a lapping machine by placing the pieces to be lapped upon a platen externally of the lap and arranged to occupy a space which is the same in size and contour as that within a ring, and then transferring the pieces so arranged to the interior of the ring.

A further object of this invention is the provision of apparatus for automatically removing articles from a work-holding ring and replacing removed articles with articles to be lapped.

A still further object of this invention is the provision of apparatus for automatically removing lapped articles from between a lap and a pressure plate and inserting articles to be lapped therebetween.

These and other objects of this invention will become apparent from the following detailed description of a preferred form of the invention shown in the accompanying drawings in which;

FIG. 1 is an enlarged end elevation in quarter section of a typical part to be lapped;

FIG. 2 is a plan view of a three-ring flat lapping machine to which this invention has been applied;

FIG. 3 is a front elevational view of the upper portion of the machine of FIG. 2;

FIG. 4 is a side elevational view of the upper portion of the machine of FIG. 1;

FIG. 5 is an enlarged fragmentary side elevational view in section of the machine of FIG. 2 taken along line 5-5 of FIG. 2 and showing one stage of operation thereof;

FIG. 6 is a view similar to FIG. 5 showing the machine in another stage of its operation;

FIG. 7 is a schematic front elevational view in section showing the machine in yet another stage of operation, the view being taken along line 7-7 of FIG. 2;

FIG. 8 is a schematic front elevational view in section similar to FIG. 7 showing the machine of FIG. 2 in a further stage of operation;

FIG. 9 is a plan view on an enlarged scale of a slide used in the loading operation;

FIG. 10 is an enlarged fragmentary side elevation of the slide of FIG. 9 taken in the direction of the arrows 10-10 of FIG. 9;

FIG. 11 is a side elevational view in section and on an enlarged scale of the indexing mechanism for the machine of FIG. 2 looking in the direction of the arrows 1111 of FIG. 2;

FIG. 12 is an enlarged plan View in section of the indexing mechanism taken along line 1212 of FIG. 11;

FIG. 13 is a rear elevational view of certain limit switches used in the machine, taken along line 1313 of FIG. 11;

FIG. 14 is a plan view of a portion of the article feed mechanism; and

FIG. 15 is a schematic diagram of the hydraulic and electric circuits and controls therefor.

By way of general description, the apparatus in this invention comprises a fiat annular rotatable lap on which are disposed a plurality of work stations, with means for periodically turning the stations through an angle of such magnitude as to present the stations successively to a platform located at the side of the lap. Each station is defined by a large, heavy ring which not only contains the pieces to be lapped, but also continuously conditions the lap. The parts to be lapped are retained within the ring and held against the lap by a pressure plate pivoted on a rotatable arm forming part of the indexing mechanism. The ring and its contents are slid off the lap and upon the platform where the ring remains during the unloading and loading operations. The elevator disc is lowered to a base plate on which is a slide which pushes the finished pieces off the disc and slides pieces to be lapped upon the disc. The latter is then raised into level with the ring, and tne ring and pieces are slid back upon the lap. The indexing mechanism then turns the freshly loaded ring away from the loading and unloading station and brings an adjacent ring to said station preparatory to unloading it.

Although the apparatus and method of the present invention are adapted for use with a large variety of work pieces, they will be described for purposes of illustration with reference to work pieces in the form of sealing washers such as are used in rotary mechanical seals. These washers are relatively small, on the order of l to 2" in diameter, and have a narrow, raised face which must be lapped flat and smooth. One such typical sealing washer is shown in FIG. 1 and may be a plastic, metal or ceramic ring having a surface which is to be lapped flat and smooth. It may have a flange 11 spaced more or less centrally between its ends, and its ends may be of unequal diameter.

The lapping machine (FIGS. 2, 5 may have an annular lap plate 12 rotatable about a vertical axis and formed with a flat upper work surface 13 to which loose abrasive and lapping vehicle are applied in any suitable well-known manner. The washers 14 to be lapped are placed within a wear ring 15 which functions as a work holder and also as a lap conditioner, as explained in the aforementioned Bullard reissue Patent No. Re. 23,937. As shown more clearly in FIG. 5, the ring 15 surrounds the washers 14 and holds them on the annular work surface 13 of the lap 12. Wear ring 15 is in turn held on the lap by a loosefitting, disc-shaped pressure plate 16 which is inserted in the ring 15 and rests upon the upper ends of washers 14 to produce washers of uniform thickness and finish. Pressure plate 16 is rotatable on the end of a vertical guide bar 17 which extends upwardly into a cross head 18 slidably mounted in a horizontal guide 19 forming the indexing part of the overhead structure 20 of the lapping machine.

Guide bar 17 may be rectangular in cross section and passes through a suitable opening 21 in the cross head 18. A vertical slot 22 is formed in guide bar 17 and a horizontally disposed pick-up rod 23 passes through cross head 18 and slot 22, said pick-up rod extending outward horizontally beyond either end of cross head 18. The right hand end of pick-up rod 23, as viewed in FIG. 5, is threaded into the cross head 18 and a lock nut 24 serves to fix said rod 23 in place relative to cross head 18. The left hand end of rod 23, as viewed in FIG. 5, is formed with a head 25 and the right hand end of said rod has afiixed thereto by any appropriate means a washer 26 which is of larger diameter than rod 23 and comparable in diameter to the diameter of head 25.

As shown more clearly in FIG. 2, fixed guide 19, in the machine chosen to illustrate this invention, is one of three identical guides spaced 120 apart, said other guides being shown at 27 and 28. Each of said guides is welded to a drum 29 (FIG. 5) in appropriate openings formed therein for said guides, said drurn being closed at its lower end, as viewed in FIG. 5, by a pair of concentric, washer-like plates 30 and 31, the inner one 31 of which is centered on a pin 32 extending below the end 33 of a vertical shaft 34. The inner plate 31 is secured by screws or other suitable fasteners to lower end 33 of shaft 34 so as to be fixed thereto and rotatable therewith. Shaft 34 is supported in anti-friction bearings 35 (FIG. 11) mounted against vertical movement in a vertically disposed multi-element post 36 forming part of the fixed frame of the machine.

The lower end of post 36 has a peripheral groove 37 formed in a stepped portion thereof, the groove being partly closed by a pair of

rings

38, 39 which are axially separated a distance just a little greater than the diameter of pick-up rod 23 to form a slot through which said rod may extend and in which said rod may revolve around post 36. In just one location, however, the

rings

38 and 39 are enlarged to form an opening 40 large enough to allow head 25 of rod 23 to pass radially outwardly therethrough. In all other locations, head 25 is retained by

rings

38, 39 and the bottom of groove 37 against radial movement relative to post 36. It is contemplated that shaft 34 will be rotated through three times during the lapping cycle for the work pieces being lapped, so that each of the

guides

19, 27 and 28 will successively occupy the location shown by guide 19 in FIG. 2. This location is the one from which the Wear ring 15 and its contents are slid off the lap 13 and on to an adjacent apparatus where the finished parts are removed from the wear ring and parts to be lapped are inserted thereinto. It is in this location that opening 40 is formed.

The machine is provided with a base 41 (FIG. 4) containing the drive mechanism (not shown) for the lap plate 12, and with a post 42 containing the lapping compound used during the lapping process. Adjacent base 41 and fixed thereto is a table 43 from which extends a bracket 44 for supporting a pair of relatively light posts 45, 46 (FIG. 3). A bridge 47 is secured to the top of posts 42 and extends to the right, as viewed in FIG. 4, toward

posts

45, 46. To the bottom of bridge 47 are secured weldments collectively designated by the number 48 which extend outwardly toward the right as viewed in FIG. 4 over

posts

45, 46 and are appropriately welded or otherwise secured to the tops thereof.

Weldments 48 comprise (FIG. 5) spaced

vertical cross-plates

49, 50, 51 and 52, a bottom plate 53 and sides plates 54 and 55 (FIG. 7), all of which are appropriately welded together. To the bottom of bottom plate 53 are welded spaced parallel guide bars 56 and 57, the adjacent faces of which are formed with grooves 58, 59 in which the cross-head 18 is received for sliding movement therein. As shown clearly in FIG. 7, crosshead 18 has a circular cross section and grooves 58 and 59 are correspondingly contoured to allow said crosshead to rotate slightly in said grooves as a self-adjusting feature during the unloading and loading of a wear ring. Cross plates 49 and 50 (FIG. 5) and bottom plate 53 have

slots

60, 61 and 62, respectively, formed therein to allow the upper portion of guide bar 17 to pass therethrough during the unloading and loading cycles of the apparatus.

A plate 63 (FIG. 5) is secured across the ends of the guide bars 56, 57 and serves to support a hydraulic cylinder 64 which passes between the

posts

45, 46 and has its axis disposed parallel with the guide bars 56, 57 and concentric with the cross-head 18. Plate 63 has an opening 65 therein through which extends the piston rod 66 of cylinder 64 for reciprocation therethrough. The left hand end of rod 66 as shown in FIG. 6 is secured to an adaptor 67 having the same cross section as cross-head 18 and slidable in the grooves 58, 59 in guide bars 56 and 57. Said adaptor 67 is held against rotation by a strap 68 secured to the bottom of the adaptor and extending downwardly between guide bars 56 and 57. Said strap terminates in a downwardly extending flange 69 on which is mounted an adjustable switch contact point 70. The left hand side of adaptor 67 as viewed in FIG. 6 has a horizontal slot 71 formed therein which is of reduced width at its left hand extremity (FIG. 6). The width of slot 71 at its inner end is sufficient to receive the washer 26 of pick-up rod 23, and at its left-hand extremity 72 is just sufficient to receive the pick-up rod 23 so that said end of the adaptor 67 acts as a claw to grasp the washer 26 and cause the cross-head 18 to move with adaptor 67.

Referring now to FIGS. 3, 4 and 7, table 43 may be comprised of a casting 73 which is somewhat L-shaped in elevation and is secured at its side 74 to base 41. Casting 73 has a rectangular base plate 75 secured to the top thereof, said base plate as shown in FIG. 7 having three

openings

76, 77 and 78 therein. Slidably disposed on base plate 75 is a slide 79 which is likewise rectangular in outline, but Which has only two openings (FIG. 9)

80 and 81 therein. Said openings are connected by a slot 190 for purposes to be hereinafter described. Said slide 79 is reciprocable from a position in which opening 80 is concentric with opening 76 in base plate 75 and opening 81 at the same time is concentric with opening 77 in said base plate 75, to a position in which opening 80 is concentric with opening 77 and opening 81 is concentric with opening 78 in base plate 75.

The means for reciprocating slide 79 between its two positions mentioned above comprises a pair of spaced

brackets

82 and 83 which are bolted to the side of slide 79 remote from lap 13 and which have appropriate openings therein through which passes a guide and support rod 84. Said guide rod is in turn supported from brackets 85 and 86 (FIGS. 2 and 3) similarly secured to base plate 75. The opposite side of slide 79 is guided by a gib 87 on base plate 75. A hydraulic cylinder 88 of any well known construction is mounted below guide rod 84 and supported in such position by brackets 89 and 90 (FIG. 3), the axis of cylinder 88 being parallel with the axis of guide rod 84. The operative end of cylinder 88 is secured to an extension 91 (FIG. on bracket 82 so that when the cylinder is operative, bracket 82 is reciprocated in a horizontal direction and its movement is guided by guide rod 84.

Referring now to FIGS. 4-7, immediately above opening 77 in base plate 75 is a platform 92 which is in the form of a plate secured at one end 93 by an adjustable shoulder screw 94 to a lug 95 extending from casting 73, and by similar adjustable shoulder screws 96, 97 (FIG. 2) at the side of platform 92 adjacent lap 13 to corresponding lugs 98 on base 41. Said

adjustable screws

94, 96 and 97 support platform 92 on the shoulders of said screws, and the height of the platform relative to the surface of lap 13 may be regulated by turning said screws in their lugs to raise or lower the screw shoulders on which the platform is supported. Once an appropriate position for the platform is arrived at, the threaded upper ends of the adjusting screws are then locked against turning by nuts 99 which lock against platform 92.

A rectangular notch 194 is cut out in platform 92 between the adjusting screws 96, 97 and adjacent lap plate 12 to accommodate a flipper plate 100 (FIGS. 2, 5 and 6) of substantially the same rectangular configuration except that the side 101 of plate 100 adjacent lap plate 12 is contoured to fit closely the circular edge of said lap plate. Flipper 100 is pivoted at 102 to platform 92. A cylinder 103 disposed below flipper plate 100 and connected to it by a pivotal connection 104 is adapted to oscillate said plate 100 about pivot 102 so that in one position the contoured edge of the plate is raised above lap surface 13 and in the other position it is lowered below said lap surface 13. It is contemplated that flipper 100 will be in its raised position relative to lap surface 13, when articles are to be slid upon lap surface 13 from platform 92, and will be lowered below lap surface 13 when articles are to he slid off lap surface 13 and upon platform 92. This arrangement avoids having the lapped articles strike either the flipper plate or the lap plate in their movement from one to the other.

Platform 92 as shown in FIGS. 5, 6 and 7, has a circular opening 195 which is slightly larger in diameter than the internal diameter of a wear ring and therefore larger than the diameter of pressure plate 16. Concentrically arranged with respect to opening 195 is a disc-shaped elevator plate 105 which has a flat upper surface 106, the diameter of the elevator plate 105 being slightly less than the diameter of the opening 195 in platform 92, so that said elevator plate 105 may be inserted into said opening with its upper surface 106 co-planar with the upper surface of platform 92. Thus wear ring 15 and its contents may be slid from lap surface 13 across flipper plate 100 and disc-shaped elevator plate 105 to a position wherein the ring rests upon platform 92 with its axis coinciding with the axis of the elevator plate 105. In this position all of the lapped parts rest upon the elevator plate 105.

The axis of elevator plate coincides with the center of the opening 77 in base plate 75 so that plate 105 may be lowered into said opening 77. When so lowered its upper surface 106 is co-planar with the upper surface of base plate 75 so that the articles to be lapped, or that have been lapped, may he slid laterally off upper surface 106 of elevator plate 105 and upon said base plate 75 to load or unload the wear ring 15.

The raising and lowering of the elevator disc 105 is effected by a rod 107 (FIG. 7) suitably supported in a guide 108 fixed to the casting 73. A hydraulic cylinder 181 of well-known construction may be secured to casting 73 in coaxial relation with rod 107 and connected to the lower end thereof whereby to raise and lower said rod and the elevator plate 105 carried thereby.

The placing of articles to be lapped upon surface 106 of elevator plate 105 and the removal of lapped articles from said surface is accomplished by the aforementioned slide 79 (FIG. 7). When opening 81 in slide 79 is concentric with elevator plate 105, the other opening 80 in slide 79 is concentric with a turntable 110 disposed in opening 76 of base plate 75 and having an upper surface 111 level with the upper surface of said base plate 75. Said turntable 110 is mounted on a shaft 113 extending upwardly from a motor 114 secured to the under side of a mounting plate 115 suitably secured to casting 73 (FIGS. 4 and 10), said mounting plate 115 having an opening therein through which shaft 113 extends.

Opening 80 of slide 79 comprises the fill cavity of the mechanism into which the articles to be lapped are placed in predetermined order, orientation and number. As shown more clearly in FIG. 2, the articles to be lapped, in the example shown, washers of the type shown in FIG. 1, are dumped indiscriminately into a vibrating type of feed mechanism shown fragmentally at 116. Said vibrator may be of the well-known Syntron type, and, by an appropriate arrangement of track, sensing fingers or the like disposed around the perimeter thereof, said washers are progressively oriented with the surface 10 thereof to be lapped lowermost and are made to slide by gravity down a downwardly inclined chute 117 which terminates at the side of a star wheel 118, so that said star wheel normally blocks exit of the washers from the chute 117. Said star wheel 118 has

curved notches

119, 120 formed in the sides thereof, the greatest radial dimension of which is just sufficient to receive a washer to be lapped therein. Said star wheel 118 is mounted on a shaft 121 (FIG. 7) which is connected to and driven by a motor 122 disposed below and secured to mounting plate 115. Said motor 122 is designed to rotate star wheel 118 in a clockwise direction as viewed in FIG. 2. Motor 114, on the other hand, is designed to rotate turntable 110 in a counter-clockwise direction as viewed in FIG. 2. Star wheel 118 is mounted above, and overlaps, turntable 110 by an amount substantially equal to the greatest radial depth of the curved notch 119 so that when star wheel 118 is rotated, it brings a washer over turntable 110 and the washer is dropped down upon said turntable. The rotation of said turntable 110 carries the dropped washer around from beneath the rotating star wheel 118.

The construction of star wheel 118 and the adjacent structure is shown more clearly in FIG. 14. It may be noted that star wheel 118 rotates within a housing 133 which is in the form of a substantially flat disc resting upon and secured to base plate 75. Said housing 133 is located on plate 75 to overhang turntable 110 and is cut out at 134 to eliminate the otherwise overhanging part thereof. Housing 133 is formed with a vertical retaining flange 135 which serves to hold a washer in the rotating star wheel 118 until said washer passes over turntable 110 where it leaves housing 133 and drops upon said turntable. Flange 135 is interrupted at 136 to admit the exit end of the feed chute 117 (FIG. 2) from which the washers or circular articles to be lapped enter the star wheel.

A circular track 137 is formed in housing 133 as a groove adjacent retaining flange 135 along which the washers are pushed by the star wheel.

The exit end of track 137 has a downwardly sloping portion 138 which lowers the washer to about one-half the elevation of the track 137 above surface 111 of turntable 110. The washer is dropped the remainder of the distance along a downwardly sloping portion 139 (FIGS. 9 and of the slide 79 which is interposed between the housing and turntable 110. The gradual lowering of the washer from the track 137 to the surface 111 of turntable 110 avoids excessive tipping of the article and possible turning of the washer as it leaves the star wheel and enters the turntable.

To make certain that a vacant space is available on turntable 110 as a washer is transferred from track 137 to the turntable a deflector 140 in the form of a bent plate extending vertically from the surface 111 of turntable 110 is mounted on a block 41 fixed to base plate 75. As shown in FIG. 14, said deflector plate 140 is disposed at an angle to a radius of turntable 110 so that any washers traveling with said turntable 110 at the perimeter thereof will strike the deflector plate and be caused to move radially inwardly of the turntable, thereby leaving a clear space on the other side of the deflector at the exit end of the track 137 into which a washer to be transferred to turntable 110 may fall.

It is contemplated that a predetermined number of articles, such as the washers shown in FIG. 1, will be fed to turntable 110 by star wheel 118, and that as soon as the predetermined number has been so fed, the star wheel and turntable will cease to rotate and will remain stationary until the washers upon turntable 110 have been moved off by slide 79 and said slide has returned to its loading position. To this end a parts counter 142 (FIG. 7) is provided, said parts counter being of well-known construction and hence will not be described in detail herein. Said counter is provided with a roller-operated switch arm 143 which rides upon the surface of star wheel 118 above track 137 so that each time a washer passes under said roller a circuit is established through a counting mechanism such as a step switch (not shown) connected in the circuit to the

motors

122 and 114. When the step switch achieves a predetermined position corresponding to the number of washers desired on turntable 110, the circuit to the

motors

122 and 114 is broken and said motors cease to operate. A bracket 144 secured to the top of base plate 75 is provided on which said counter 142 may be mounted.

The means by which the

guides

19, 27, 28 for the wear rings are periodically turned through 120 and precisely indexed with respect to the cylinder '64 and its adaptor 67 is shown in greater detail in FIGS. 11, 12 and 13. Shaft 34, to which the

guides

19, 27 and 28 are aflixed, extends upwardly into a housing 145 made preferably of weldments and supported on overhead structure or bridge in the manner shown in FIG. 4. To the upper end of shaft 34 is keyed a driven gear 146 which is adapted to mesh with a drive pinion 147 slidably keyed to a vertically disposed shaft 148. In the illustrated example, gear 146 has twice the number of teeth of drive pinion 147. Shaft 148 is in turn keyed to the output shaft 149 of a rotary type hydraulic cylinder 150 appropriately secured to the top of housing 145.

It is contemplated that cylinder 150 will produce an oscillatory motion in shaft 149 and in its associated shaft 148 and thereby impart on oscillatory movement to gear 147. It is, however, desired that the driven gear 146 which drives shaft 34 rotates in but one direction, and, therefore, means are provided for disengaging gear 147 from gear 146 during the return movement of the oscillation of shaft 148 and the subsequent reengagement of gear 147 with gear 146 in the drive direction of oscillation of said gear 147. The disengaging mechanism is comprised of a plate 151 which has an opening 152 therein to receive the hub 153 of gear 147. Said plate 151 has a notch 198 at its right hand end to receive the necked portion 196 of a reciprocable rod 197 connected to be driven by a hydraulic cylinder 154 mounted on the top of housing adjacent the rotary hydraulic cylinder 150. A retainer 155 having a notch 156 therein to receive a small segment of gear 147 therein is also mounted on the necked portion 196 of the rod 197. Thus gear 147 is retained between the plate 151 and retainer 155 so that as the rod 197 is oscillated vertically, gear 147 is constrained to move with it. Said gear 147 slides vertically on shaft 148 to which it is slidably keyed through a key 157. It is contemplated that gear 147 will be raised by shaft 148 sufliciently to disengage it from gear 146, and while in this raised condition, it will be rotated in a reverse direction by the cylinder 150 through 240 whereupon it may again be lowered to engagement with gear 146 for the forward movement through the same 240. Since pinion 147 has half the number of teeth of gear 146, the latter will be rotated through 120, and its attached guides 19, 27, 28 will be similarly rotated through 120.

It is necessary, however, that the

guides

19, 27, 28 remain precisely located while the drive gear 147 is disconnected from gear 146 and is oscillated backward through the 240. To insure holding each said guide in its correct position, an interlock is provided between plate 151 and the frame of the machine, and a second interlock is provided between gear 146 and plate 151 so that, in effect, gear 146 is locked to the frame of the machine during the return movement of drive gear 147.

The aforementioned interlock is comprised of a rack 158 which is suitably secured to an upper plate 159 forming part of bridge 20, said rack 158 having teeth 160 which mesh With corresponding teeth 161 on the adjacent end of plate 151, three teeth on plate 151 being sufiicient for this purpose. The thickness of plate 151 is greater than the axial width of the teeth on driven gear 146 so that when the plate 151 is raised with the drive gear 147, the teeth on plate 151 will engage the teeth of gear 146 while at the same time engaging the teeth 160 on the rack 158. Thus while gear 147 is completely out of contact with gear 146, the latter is held rigidly against rotation by its interlock with the teeth on plate 151 and the interlock of the teeth on plate 151 with the teeth 160 on rack 158. During the rotation of gear 147, therefore, gear 146 is held against rotation and cannot move until plate 151 is lowered out of mesh with the teeth on gear 146, and gear 147 is again made to mesh with gear 146.

The operation of the various cylinders is controlled by solenoid operated valves, the solenoids in turn being controlled by electrical switches in the form of limit switches operated by the devices to be controlled. In the case of the oscillating shaft 148, however, positive stops are provided at either end of the oscillation to insure an exact indexing of the fixed guides 19, 27 and 28. Said fixed stops are shown in FIG. 12 and are comprised of

blocks

162, 163 secured to plate 151 and provided with

arms

164, 165 which extend upwardly and radially inwardly over drive gear 147. Adjustable stop screws 166, 167 are mounted in the

arms

164 and 165, respectively, and are adapted to be contacted by a pin 168 extending vertically above and doweled in the upper surface of gear 147. Thus, as gear 147 oscillates between its two positions, it carries pin 168 with it, and said pin, upon striking the

stops

166 and 167, definitely limits the oscillatory movement of the gear in either direction and thereby limits the movement of the driven gear 146. Inasmuch as said gear 146 is keyed to shaft 34, the control of the movement of gear 146 effectively controls the movement and, of course, the location of the

guides

19, 27 and 28.

The limit switches for the oscillatable cylinder 150 are disposed above said cylinder and are mounted on a plate 169 disposed thereon. Shaft 149 of the cylinder 150 extends above plate 169 and has secured to it an arm 170 (FIG. 2) with a pair of axially (vertically) spaced adjustable contact screws at the end thereof. A switch 171 controls the limitation of the return movement of the cylinder 150, and a switch 172 controls the driving movement of said cylinder 150, and hence the point at which the drive for the indexing movement of the

guides

19, 27 and 28 terminates. Said switches 171 and 172 are disposed at different elevations so that the separate adjustable contact screws on arm 170 may operate their respective switches.

The limit switches for controlling the solenoid-operated hydraulic valve for cylinder 154 which raises and lowers gear 147 are shown in FIG. 13. They are mounted on a bracket 173 which is secured to the top of housing 145 and immediately adjacent cylinder 154. The limit switches are shown at 174, 175, and the operator for the switches is comprised of an arm 176 extending through an opening 177 and secured to the piston rod of cylinder 154 so as to be movable there-with. On the end of arm 176 are two oppositely disposed adjustable contact screws 178, 179, contact screw 178 being adapted to operate switch 174 and contact screw 179 being adapted to operate switch 175.

As stated above, the lapping machine of this invention will be furnished with the usual manual start and stop switches as well as with an electrical timer switch which controls the length of time that the machine will run before automatically being stopped. The running time is calculated to be one-third of the total time required to produce a finish article on the machine. The actual cycle time for lapping a work piece will be increased by the length of time required to load and unload each wear ring on the lap plate. It is contemplated that the timer switch, upon reaching the end of each third of a cycle, will initiate the unloading operation which then will automatically trigger the succeeding operations as they occur until the unloaded wear ring is returned to the lap plate with a fresh load of parts to be lapped, whereupon the next third of the timed cycle will occur. It is also contemplated that the indexing will be accomplished simultaneously with the operation of each third of the timed cycle, for the reason that it is easier to shift a ring along the lap surface if the lap surface is already in motion. The direction of indexing is the same as the direction of rotation of the lap so that a minimum of power is required to accomplish the indexing.

Prior to the operation of the machine, it is necessary to set in operation the vibrating feed hopper 116 so that there is available in chute 117 a supply of washers suitably oriented as to the surface to be lapped thereon and arranged in a row terminating at the star wheel 118.

Motors

114 and 122 are then started so that the star wheel carries washers one at a time from the chute 117 to turntable 110 upon which the washer is dropped. With turntable 110 rotating the dropped washer is carried around until it strikes the deflector rail 140, whereupon it is moved radially inwardly so that succeeding washers carried around by star wheel 118 may drop upon a clear area on turntable 110. Each washer, as it passes the counter 142, is counted thereby, and when the predetermined number of washers for a load has passed counter 142, a pulse is transmitted thereby to a relay which stops the rotation of the

turntables

114 and 122 and readies the machine for an unloading and loading cycle.

The time at which the unloading cycle commences is determined by the machine timer which, when the timing cycle is completed, stops the lap plate and then energizes cylinder 64 to cause piston rod 66 (FIGS. and 6) and the adaptor 67 connected thereto to pull the crosshead 18 and its associated guide bar 17, pressure plate 16, wear ring 15, and the articles 14 to the right, as viewed in FIG. 6, upon platform 92. Just prior to the energization of cylinder 64, cylinder 103 was energized to lower its piston and flipper plate 100 was tilted downwardly toward lap plate 12, so that the edge 101 thereof adjacent edge 13 of lap plate 12 was slightly lower than the lap surface 13, thereby facilitating sliding the finished washers 14 off the lap surface and upon platform 92. The movement to the right as seen in FIG. 6 of the cross-head 18 terminates when wear ring 15 strikes a switch 180 mounted on platform 92 at a position where wear ring 15 is disposed concentrically with respect to the circular opening 195 in said platform 92. At this point cylinder 64 is at the end of its stroke and the washers 14 rest upon the flat upper surface 106 of disc-shaped elevator plate 105. Said plate is normally in its raised position wherein its surface 106 is at the same level as the upper surface of platform 92.

The stopping of wear ring 15 and the operation thereby of switch initiates the operation of the solenoid controlling the valve for vertical cylinder 181 which is under elevator plate 105 and to which said plate is connected by rod 107. Cylinder 181 then lowers the elevator plate 105 to the surface of base plate 75. In the process, the washers 14, pressure plate 16, and guide bar 17 are lowered until the pick-up rod 23 passing through slot 22 of the guide bar 17 reaches the upper end of said slot 22. At that point, the guide bar 17 and pressure plate 16 are suspended from the pick-up rod 23 while elevator plate 105 and the washers 14 thereon continue down to the surface of base plate 75.

Inasmuch as the lapping vehicle used in the lapping operation is somewhat oily and the washers may become wrung upon the bottom surface of pressure plate 16, some of the washers may remain adhered to the pressure plate. To assure the removal of these adhered washers, a semicircular scraper 182 is secured to the upper surface of the slide 79 around the right half (as vie-wed in FIG. 7) of the opening 81 in the slide which is concentric with elevator plate 105. In descending from platform 92 to base plate 75, elevator plate 105 passed through the opening 81 in slide 79, and the upper surface 106 of the elevator plate 105 came to rest even with the upper surface of base plate 75.

The downward movement of the rod 107 of cylinder 181 caused an arm 109, which is connected to and movable with rod 107, to descend likewise. Said arm 109 is provided with spaced switch contact screws 183, 184 which contact switches controlling the solenoid operated valves for succeeding cylinder operations. Thus contact 183 strikes a switch 185 on the downward movement of the rod 107 to energize the valve for cylinder 88 and contact 184 strikes a switch 186 which energizes the valves for

cylinders

64 and 103 in the upward movement of rod 107. The operation of cylinder 88 (FIG. 3), the piston rod 199 of which is connected to slide 79, causes said piston rod 199 and said slide 79 to move to the left, as viewed in FIGS. 3 and 7. This movement of slide 79 causes; (a) a scraping of adhered washers 14 from the under surface of pressure plate 16 by scraper 182; (b) a scraping of the washers 14 from the upper surface of elevator plate 105 into opening 78 in base plate 75 through which they fall upon the dump trough 187; and (c) a transfer of the washers that have been loaded on turntable 110 to the upper surface 106 of the elevator plate 105. At the termination of the leftward movement of piston rod 199 of cylinder 88, a contact 188 on said rod strikes a switch 189 on bracket 85 of the machine.

With switch 189 operated, the solenoid operated valve for vertical cylinder 181 is then energized to raise elevator plate 105 and the washers just loaded thereupon to pressure plate 16, and then to continue the raising of the washers 14 and the pressure plate 16 through the opening 104 in platform 92 and into the wear ring 15 until surface 106 of elevator plate 105 is level with the upper surface of the platform 92. At the end of the upward movement of rod 107 contact 184 on arm 109 moving with rod 107 strikes switch 186 to energize the solenoid operated valves for

cylinders

64 and 103. Said cylinder 181 remains in this condition throughout the remaining third of a cycle.

Meanwhile, the energization of switch 186 also causes cylinder 88 to be energized to move rod 199 to the right, as viewed in FIG. 3, and thereby move slide 79 to the right until the opening 80 therein is concentric with turntable 110. During such movement of slide 79 to the right,

rod 107, which extends through opening 81 in slide 79, may nevertheless pass from one opening to the other through the previously mentioned slot 190 provided for that purpose in slide 79.

The energization of switch 186 also energizes the valve for cylinder 64 to cause said cylinder to move its rod 66 to the left, as viewed in FIG. 5, and also energizes the solenoid operated valve for cylinder 103 to raise flipper plate 100 slightly above the surface 13 of lap 12 so that as wear ring 15, its pressure plate 16 and washers 14 are slide to the left, as viewed in FIG. 5, from elevator plate 105 to the lap surface 13, said washers 14 may make the transition without difficulty.

The movement of wear ring 15 upon surface 13 of lap plate 12 is accompanied by the movement of head of pick-up rod 23 into the peripheral groove 37 in post 36, and by the establishment of contact between the contact point 70 movable with adaptor 67 on piston rod 66 with a switch 191 disposed at the intended end of the travel of said piston rod 66. Said switch 191 starts the next lapping cycle and completes a circuit through switch 171 (FIG. 2) controlling the rotary cylinder 150 to rotate shaft 34, guides 19, 27 and 28 and all of the wear rings, until arm 170 contacts switch 172 and pin 168 contacts stop screw 167.

Switch 172 causes cylinder 154 to be energized to lift rod 197, which then causes contact screw 178 (FIG. 13) to actuate switch 174 to energize rotary cylinder 150 in the opposite direction, thereby raising drive pinion 147 (FIG. 11), locking driver gear 146 to rack 158, and turning pinion 147 back to its starting position. At this point, switch 171 is reset to repeat the indexing of the

guides

19, 27 and 28 upon the reloading and placing of the next wear ring 15 on lap 12.

The return of slide 79 to its right hand position, as viewed in FIG. 1, is accompanied by the actuation of a switch 192 which resets the counter 142 and activates

motors

114 and 122 to start the loading of washers to be lapped, upon turntable 110.

' In the foregoing manner, each of the three stations represented by

guides

19, 27 and 28, is successively loaded, indexed through 120 three times, unloaded and reloaded automatically without attention on the part of the operator other than to see that the vibrator feeder 116 is full and that the finished parts leaving the chute are properly disposed of.

Because of the sequential nature of the operation of each step or stage of the machine, a malfunction in any of the stages, such that said stage is not completed, will halt the operation of the entire machine. Thus, if an insufiicient number of washers should be fed to the turntable 110, the counter switch 142 will not be motivated to send the necessary pulse to the next stage, and therefore the machine will stop until the reason for the incomplete filling is determined and corrected. Suitable overcontrol may be provided as necessary to bypass a non-operative switch manually to test and adjust each of the stages of operation of the machine. Such manual controls are within the skill of those working in the art and hence are not detailed herein.

The cylinders illustrated above are operated by oil under pressure from a suitable source conducted to a header 200 from which individual lines are run to the four-way valves shown schematically associated with each cylinder. From the four-way valves the oil under pressure is conducted through check valves with restricted return flow to each side of each cylinder with the exception of the flipper cylinder 103 which is of short stroke and intended to operate rapidly. Said cylinder 103 has avalve 201 with a tension spring 202 on one side instead of a solenoid. Elevator cylinder 181 has a check valve 203 in its line from header 200 to hold said elevator in whatever position it is in when the machine is shut down.

A latching relay is provided which has a set coil 204 and a vent coil 211. Adjustable contacts 205 and 206 are closed in the set position, as are also contacts 207.

Adjustable contacts

208 and 209 are closed on the reset position of the latching relay. Contacts 210 are closed on count-out of counter 142 which then energizes the reset coil 211.

The timer, shown in block outline at 212 has contacts 213-217 and line contacts 218.

Contacts

214, 215 are the output line contacts to energize the motors and relays, contact 210 is energized on completion of timing and contact 217 is energized during timing. Contact 213 is connected to the timer reset clutch and is also connected to one side 213 of switch 189. Contact 215 is also connected to the other side 214 of switch 189.

The lapping machine described above will automatically load and unload itself as long as sufiicient numbers of parts to be lapped are supplied to the counting mechanism. If an insufficient number of parts is available, the parts counter disables the entire mechanism. Due to the sequential operation of the switches by the elements of the machine, a failure of any element to complete its movement will likewise disable the entire mechanism. The machine thus reduces the time during which the lap is stopped and unproductive and at the same time frees an operator for work on additional machines.

I claim:

1. Apparatus for loading a circular space with a plurality of substantially identical workpieces having a flat surface to be lapped, said apparatus comprising a feed track having a plurality of said workpieces thereon with their said fiat surfaces uniformly oriented with respect to the track, a plate adjacent the track, said plate having a circular opening therein defining a circular space and adapted to receive a plurality of oriented workpieces, a turntable concentric with said circular opening and adapted to support said plurality of oriented workpieces in said circular opening, means for rotating said turntable, and means for transferring the workpieces from the track to the circular opening while the turntable is rotating, said last-mentioned means extending across the end of said feed track such that when said last-mentioned means is inoperative, movement of workpieces out of said feed track is blocked.

2. Apparatus as described in claim 1, a disc having a lapping surface in proximity to said turntable, an elevator adjacent to and coplanar with said turntable and having a circular surface substantially equal in area to the area of the circular opening in the plate, said turntable being lower than said lapping surface, a second plate substantially coplanar with said lapping surface and having a circular opening therein of substantially the same size as the circular opening in the first plate and disposed over and concentrically with said elevator, means for shifting said first plate laterally to bring the circular opening therein in registry with the elevator, means for raising said elevator into the opening in said second plate, and means for sliding workpieces from the raised elevator across said second plate and upon the lapping surface.

3. Apparatus as described in claim 2, said second plate comprising a fixed part, a vertically movable part adjacent the lapping surface, means remote from the lapping surface hinging the vertically movable part to the fixed part, and means for raising the movable part above the lapping surface when workpieces are slid from the raised elevator across said second plate and upon the lapping surface.

4. Apparatus as described in claim 2, said means for sliding workpieces from the raised elevator comprising a ring adapted to receive said workpieces therein, a frame, guide means extending over the lapping surface and over the elevator, a crosshead in said guide means and slidable between a position over said lapping surface and a position over said elevator, means on the crosshead engageable with said ring to compel movement of the ring with 13 the crosshead, and means for moving the crosshead along said guide to move a ring and workpieces therein between the elevator and lapping surface.

5. Apparatus as described in claim 4, said guide means being comprised of aligned first and second parts, means fixing the first part to the frame, a vertically disposed shaft mounted for rotation on the frame over the lapping surface, means fixing the second part to the shaft, and means for rotating the shaft.

6. Apparatus as described in claim 4, said guide means being comprised of a first part, means fixing the first part to the frame, a vertically disposed shaft mounted for rotation on the frame over the lapping surface, a plurality of radially extending guide parts fixed to the shaft, each of said guide parts being adapted to be aligned with the fixed guide part, and means for rotating said shaft to align said radially extending guide parts successively with said fixed guide part.

7. Apparatus as described in claim 4, said crosshead comprising a member retained in said guide means for sliding movement therealong, headed extensions on the ends of said member, a fixed circular guide secured to said frame, one of said headed extensions being received within said circular guide and held therein against radial movement, reciprocable power means fixed to the frame and having a claw movable parallel with said guide means, said claw being adapted to retain the other of said headed extensions whereby to reciprocate the crosshead in said guide means, said circular guide means being interrupted at one location to permit withdrawal of the said one extension in a radial direction from the guide means.

8. Apparatus as described in claim 2, a discharge chute aligned with said first plate, said first plate having a second opening therein disposed concentrically with said elevator when the first opening in said first plate is disposed concentrically with the turntable, said elevator being adapted to lower workpieces into the second opening, and said second opening passing over said chute to drop the lowered workpieces thereinto when the first plate is shifted laterally to bring the first said circular opening therein in registry with the elevator.

9. Apparatus as described in claim 2, said means for shifting said first plate laterally comprising a power cylinder, said means for raising said elevator comprising a second power cylinder, said means forsliding workpieces from the raised elevator across said second plate comprising a third power cylinder, solenoid-operated valve means for controlling each of said cylinders, and limit switches located in proximity to parts movable with said first plate, elevator and means for sliding workpieces for controlling the operation of said solenoid operated valve means, whereby to control the operation of said cylinders.

10. Apparatus for loading a circular space with a plurality of substantially identical workpieces having a fiat surface to be lapped, said apparatus comprising a feed track having a plurality of said workpieces thereon with their said flat surfaces uniformly oriented with respect to the track, a plate adjacent the track, said plate having a circular opening therein defining a circular space and adapted to receive a plurality of oriented workpieces, a turntable concentric with said circular opening and adapted to support said plurality of oriented workpieces in said circular opening, means for rotating said turntable, and means for transferring the workpieces from the track to the circular opening While the turntable is rotating, said last-mentioned means extending across the end of said feed track such that when said last-mentioned means is inoperative, movement of workpieces out of said feed track is blocked, said last-mentioned means comprising a Wheel having a radially extending abutment thereon adapted to engage a workpiece from said track, said wheel overlapping a peripheral zone on the turntable, means for rotating said wheel, and a circular track under said wheel and terminating at the turntable, said wheel pushing said workpieces individually by means of said abutment along said circular track and upon said rotating turntable, means contacting the workpiece as it travels over said circular track to count said workpieces, and means controlled by said counting means for disabling the means for rotating said turntable and said wheel after a predetermined number of workpieces has been counted.

11. Apparatus for loading a circular space on an annular lap with a plurality of substantially identical workpieces having a flat surface to be lapped, said apparatus comprising a ring adapted to rest on said lap and defining a circular workpiece-receiving space on said lap, a disc shaped pressure plate disposed within said ring and adapted to rest upon workpieces within said ring, a vertically disposed pressure plate guide, means on the lower end of said guide mounting the pressure plate on said guide for rotation thereon, a fixed frame disposed over said annular lap, a vertically disposed shaft rotatably mounted on said frame in concentric relation to said annular lap, a horizontal guide fixed to the lower end of said shaft, a crosshead in said horizontal guide and slidable therein, means securing said pressure plate guide in said crosshead for movement therewith, and means on the frame and cooperating with the crosshead to prevent movement of the crosshead in its horizontal guide except at a predetermined angular location of said horizontal guide with respect to said frame.

12. Apparatus as described in claim 11, there being a plurality of horizontal guides and crossheads secured to said shaft, and means for rotating said shaft intermittently to bring each horizontal guide successively to said predetermined angular location with respect to said frame.

13. Apparatus as described in claim 11, means for rotating said lapping surfacedisc, a timer controlling the operation of said lapping surface disc rotating means and preventing operation of said cylinders until said lapping surface has ceased to rotate.

14. Apparatus as described in claim 11, a platform adjacent the lap, said platform having a circular opening slightly larger than the pressure plate to permit said plate to pass therethrough but smaller than the ring, said crosshead guide extending over said opening, an elevator disc adapted to move vertically between a position wherein it is received in said circular opening to substantially below said platform, means for moving said crosshead along said crosshead guide to bring the ring pressure plate and workpieces under the pressure plate on said platform with the pressure plate and workpieces on said elevator, means for lowering said elevator, means limiting downward movement of the pressure plate on its guide such that the pressure plate is suspended over said workpieces, means for moving said workpieces laterally off said elevator, and scraper means for scraping workpieces adhered to said pressure plate off said pressure plate.

References Cited UNITED STATES PATENTS 1,835,591 12/1931 Bullard 221239 X 2,821,818 2/1958 McGee 51-215 X 2,957,281 10/1960 Hall 51--134 3,133,638 5/ 1964 Calhoun.

3,272,310 9/ 1966 Blickisdorf.

3,282,464 11/1966 Kohl 22l--1 3,304,662 2/1967 Boettcher 51-13l ROBERT C. RIORDON, Primary Examiner. D. G. KELLY, Assistant Examiner.

U.S. c1. X.R. 51 215; l98-222; 221 277