FIELD OF INVENTION;
[001] The present invention relates to the field of lapping of watch dial. The present invention in particular relates to a system and method for lapping watch dial
DESCRIPTION OF THE RELATED ART:
[002] Lapping is a well established process for finishing the tooth surfaces of gears such as bevel and hypoid gears. It is a process that provides an economical alternative to other hard finishing processes for bevel gears and it has been used in most gear manufacturing applications.
[003] In the lapping process, a pinion and ring gear are mounted, via appropriate workholdirig equipment, to respective spindles in a lapping machine that has the same basic design as a testing machine. In most instances of rolling of the gearset, the pinion is the driving member and the ring gear is braked. The gears are rolled in mesh and lapping compound, which can be a mixture of oil (or water) and silicon carbide or similar abrasive, is poured into the meshing zone. One example of a lapping or testing machine can be found in U.S. Pat. No. 6,120,355 to Stadtfeld et al.
[004] Most lapping and testing machines have three degrees of freedom available for realizing relative motion between a ring gear and pinion. The first freedom being relative movement G in the direction of the ring rear axis Z, the second freedom being relative movement H in direction of the pinion axis X, and the third degree of freedom being distance V between the ring gear and pinion axes in the direction of axis Y which is usually arranged perpendicular to the X and Z axes. The distance V is also known as the "hypoid offset."
[005] In lapping or testing processes, relative movement in the V and H directions effect positional changes in the contact pattern of the members of the gearset, in effect modifying the contact pattern. Lapping involves rotating the gear members

in mesh with contact at a desired position on the tooth surfaces. Thus, the members are located at particular V and H positions along with a particular position G to effect the desired backlash.
[006] The position of axes of machines used for lapping and testing bevel gearsets has often been gaged manually through the use of job-specific set-up gages sometimes known as cone gages. These gages are typically employed once or more per work shift to insure that the automatic machine axes are properly positioning the gear and pinion workpieces relative to one another. They can detect and compensate for many possible sources of error such as machine thermal growth, CNC scale errors, tooling dimension uncertainty, etc.
[007] These cone gages are used in pairs, one member being clamped (chucked) in place of the gear into the gear spindle workholding equipment, and the other chucked in place of the pinion into the pinion spindle workholding equipment. The two members of a cone gage pair, therefore, have several mechanical features in common with the gear and pinion, respectively, sufficient to allow them to be held by the same workholding equipment.
[008] When the machine axes are" positioned to hold a gearset in the nominal running position designed for that gearset, the machine is in the "job position". A cone gage pair indicates a gage position. If the gage position is identical to the job position, then the cone gages can be referred to as absolute cone gages. The job position is defined in three dimensions which can be given as the "pinion cone," "gear cone" and "offset" (or typically also by the X, Y, and Z axes of the machine tool). In other words, a machine whose axes are positioned to hold a gearset in its nominal job home position will hold the associated cone gage members in a "zero" or "gage" position indicated by the gages themselves.
[009] Reference may be made to the following:
[010] Patent No US2006185184 relates to a precise method for measuring and positioning gage fixture surfaces in a gear manufacturing machine. The present

invention provides a system to replace or augment the common manual cone-gage method with a method that is highly automated on a CNC machine. Two cone-gage fixtures are employed, getting clamped into the gear and pinion workholding fixtures, respectively. But instead of mechanical contact, dial indicators, or other 5 methods, a precision electronic touch probe is employed that, together with the CNC motion-controlled machine axes, can be used to measure and position gage fixture surfaces.
[Oil] Patent No CN104654989 relates to a lapping disk measurement device for a lapping machine. The lapping disk measurement device is characterized by
0 comprising an 'L'-shaped base (1), wherein a fixed pin (2) is fixedly connected with the side of the 'L'-shaped base (1); two fixed pins (2) are fixedly connected to the outer side of the bottom edge of the 'L'-shaped base (1); three dial indicators (3) are fixedly connected to the inner side of the bottom edge of the 'L'-shaped base (1); centers of three dial indicators (3) are located in the same horizontal
5 plane. With adoption of the solution, the lapping disk measurement accuracy every day is higher, and can be accurate to less than 0.05 mm. With respect to the accuracy of less than 0.5 mm of general measurement methods, the lapping disk measurement device greatly improves the accuracy, so that the lapped chips are more accurate in frequency and more concentrated, greatly improves the quality
) and yield of products, and reduces the production costs.
[012] Patent No CN103586774 relates to an online measurement device and method of mechanical surface contact lapping amount. Dial indicator holders are mounted above a base of the device, a base washer is disposed below the base, and the middle of the base is provided with a stepped through hole. A screw in
> clearance fit with the hole penetrates the stepped through hole. Two ends of the screw are connected with a top nut and a carrier plate in a threaded manner respectively. The middle of the screw is sleeved with a feed threaded sleeve which is in clearance fit with the screw. The feed threaded sleeve is connected with a lock nut and an indexing nut in JEL threaded manner sequentially from top to
) bottom. The feed threaded sleeve and the indexing nut are mounted in a stepped

hole and a locking socket of the base respectively. The top nut is sleeved with a weight. Dial indicators are mounted on the dial indicator holders and positioned with set screws. The method includes: bonding a test piece to the carrier plate, rotating the indexing nut to slightly press against the base, reversely rotating the indexing nut for certain laps, tightening the lock nut, regulating the dial indicators, placing the device on a tapper for lapping, and stopping lapping when the lapping amount reaches a preset value. The online measurement device of mechanical surface contact lapping amount is simple in structure; through the device and method, lapping amount is dynamically controlled and measured online.
[013] Patent No US4800684 relates to an apparatus for grinding and lapping sealing surfaces in slide valves and the like in situ or in the workshop has a base plate (21), a drive (6), and a rotatably mounted tool plate (3) which is connected to the drive (6) by a supporting element (4) and coupled to it by a transmission element.
[014] Patent No JPS63118099 relates to a dial for a timepiece having superior ornamental properties by subjecting an Al dial for a timepiece to anodic oxidation, electrolytic coloring and lapping.
[015] Patent No GB1067816 (A) relates to a lapping machine comprises a lapping disc rotatable about a vertical axis, at least one truing and retaining ring member disposed on the lapping disc and arranged to retain workpieces thereon, a plate member disposed within the ring member and arranged to maintain pressure on the workpieces for holding them against the movement of the lapping disc when the machine is in operation and means carried by one of the members engageable with the other of the members for arresting downward movement of the plate member upon completion of a preselected amount of lapping. A lapping disc 14,
[016] Patent No GB740729 relates to a lapping or grinding machine comprises a base 11, Fig. 1, an overframe 18 having two upstanding limbs 19 and a bridge portion 20, lower and upper laps 34, 35 having horizontal lapping or grinding surfaces, driving means for relatively rotating the upper and lower laps toward and

away from each other. The lower lap spindle is driven by a two-speed electric motor through a worm and gear wheel enclosed in an oil bath and drives through toothed gearing a shaft passing through an axial bore in the spindle. This shaft is connected by adjustable planetary gearing with three pins 36 which, when flat 5 work is to be lapped, serve to impart an orbital motion to a work holder consisting of a disc of wood or metal having a series of cut outs to receive the workpieces.
[017] Patent No GB578460 relates to a lapping machine, for treating gauges &c, comprises a work support movable by fluid pressure means to apply the work-piece to the flat face of a rotating lap, which also has a gyratory movement, with a
0 predetermined pressure; a stop device for limiting the movement of the work-piece so as to size the work also is provided. The machine comprises a base 10, Fig. 1, supporting a vertically movable wheel slide 11 carrying, on a horizontal spindle 14, a lapping-wheel 17; the slide is adjustable vertically by a screw 18 carried by the slide and engaging a nut 19 on the base, the screw being rotatable,
5 through gearing 21, 22, by a hand-wheel 24.
[018] The article entitled "Machine lapping of quartz oscillator-plates" by Wrrrrau Pannrsn, Research Laboratory, North American Philips Co., Inc. Irvi.ngton, New York talks about A three-stage high-speed lapping-to-frequency procedure using planetary-type motion laps is described in detail. 30 to 55 crystals (depending
) upon their size) are carried in five revolving work-holders between two stationary lap plates so that both sides are lapped at the same time and rate. The weight of the top plate, speed, and abrasive size are progressively reduced in the three stages. A group of crystals is transferred from one stage to the next without intermediate grouping and one random transposition is made at ca.0.0006" from
> the final thickness to equalize thickness differences and contour on both sides. Total thickness variation is *0.00002". A calibrated sensitive radio receiver coupled directly to machine laps can be used to follow the progress of the crystals and to achieve precision control of the stopping point.

[019] Patent No. US2466585 relates to a device for manufacturing indicia for the dials of watches and the like. A device according to this invention is used in connection with certain equipment, the parts of which more directly concerned are illustrated in Fig. 1. These parts comprise one or more grinding or lapping or
5 polishing discs such as discs ID and II mounted on shafts 12 and 13 respectively, journalled in a frame 14, power means for operating said discs (which power means are not shown or described inasmuch as they may be of a conventional type Well known in the art), and a guide rod for each disc parallel to the shaft thereof and fixed to frame 14, such as guide rods 15 and IB. A stop plate II is fixed to
0 frame 14 in front of wheel 11.
[020] Patent No. US8585464 relates to a lapping system includes a shaft. A stabilizing member is coupled to the shaft. A lapping tool is coupled to the shaft and spaced apart on the shaft from the stabilizing member. An adjustable force device is coupled to the shaft, the stabilizing member, and the lapping tool. The 5 adjustable force device is operable to be adjusted in order to cause the stabilizing member to support at least some of the weight of the lapping tool. The lapping system may be coupled to a valve body having a valve face to ensure alignment of the lapping tool and the valve face while providing a controlled, vertical force from the lapping tool to the valve face.
) [021] Patent No. US325296 relates to watch-dials as heretofore made, wherein the second-hand scale is depressed below the level of the face of the dial, it is customary to make the second-hand scale on a separate piece and lit it into a circular hole in the dial. In some instances, the enameled face of the dial has been out into by a hand-operated tool; but such mode of operation is slow and
> expensive. The spindle g has a pulley, g, a lever, g, pivoted atg, being employed to move the spindle g longitudinally, the connection between the said lever and spindle being, by means of a collar, 4, loose on the spindle in an annular recess, the collar having pins 5 entering holes in the lever in the usual manner.

[022] Patent No. CN102975485 relates to a transfer printing device. The water dial plate transfer printing device is mainly used for printing figures, characters and marks on a watch dial plate, and can realize automatic picking and placing of the watch dial plate so as to replace manual feeding and further improve transfer
5 printing production efficiency obviously. The watch dial plate transfer printing device comprises a vibration feeding mechanism, a transfer loading mechanism, a loading-blanking manipulator and a transfer printing mechanism; the vibration feeding mechanism provides a vibrating disc and a straight vibration feeder; the transfer loading mechanism comprises a slide loading plate and a first pushing
0 device; the loading-blanking manipulator provides a vacuum sucking disc, a second pushing device and a third pushing device; and the transfer printing mechanism provides a transfer printer.
[0231 Patent No. US2247994 relates to lapping machines and, more particularly, to a means for lapping the conical or frusto-conical faces of articles which have
5 cylindrical body portions as, for example, the valve elements of the fuel injection nozzles of solid fuel injection apparatus for internal combustion engines. This bearing support guides a rotatable shaft the lower end of which mounts the lapping element. Secured to the upper end of shaft is a pulley 3| the lower surface of which is abutted by a thrust bearing. A spring surrounds the shaft between
3 thrust bearing and the upper surface of standard 28 and serves to urge the shaft upwardly and to tend to move lapping element toward the shoulder on the under surface of the bearing support. This movement is limited in any suitable manner, as by means of a ring secured to the shaft.
[024] Thus one-stage lapping process is not very effective and successful. The 5 disadvantage of the single stage of lapping is that it requires a longer time than in the case of several stages. One of the most difficult problems is to reduce the frequency spread to a point where the large majority of the crystals can be handled as one group in the finishing operations. In all above mentioned articles there is lapping of two contact surfaces. Also there is example of lapping the surface from

both planes using heaving contact plates. Hence a system is needed which can produce good quality lapping without shade.
[025] In order to overcome above listed prior art, the present invention aims to provide a system and method for lapping watch dial which is more effective and successful .
OBJECTS OF THE INVENTION:
[026] The principal object of the present invention is to provide a system and method for dual color, dual finish lapping of stamped watch dial with index which is more effective
|027) Another object of the present invention is to provide efficient system and method for lapping double finish dial
SUMMARY OF THE INVENTION:
[028] The present invention relates to a system and method for dual color, dual finish lapping of stamped watch dial with index which is more effective. For inducing galvanizing on the stamped index dials, indexes of stamped dial are to be lapped first by removing protective lacquer layer. For doing this stone lapping process a special fixture, which is made of steel plate with slots to allow feet of dials placed easily, is used to give flat surface and equal load from back of the dial. This special fixture is used to avoid variations in the index height within 0.02 - 0.04 mm which each was between 0.05-0.08 mm with normal foam pad. Specialty in fixture in thin slots of some particular length which holds the feet of dial while lapping.
[029] The invention provides lapping of induced stamped indexes with the use of special slotted fixture plates to allow the feet of watch dials for fitment purpose. Dials are fixed on fixture plate in turn lap the indexes on stone and then after on lapping film. The special slotted fixture helps in controlling thickness and flatness variations.

BREIF DESCRIPTION OF THE INVENTION
[030] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective 5 embodiments.
[031] Figure 1 shows to fixture for stone lapping
[032] Figure 2a, 2b shows dial before and after stone lapping
DETAILED DESCRIPTION OF THE INVENTION:
[033] The present invention provides a system and method for dual color, dual ) finish lapping of stamped watch dial with index which is more effective. For inducing galvanizing on the stamped index dials, indexes of stamped dial are to be lapped first by removing protective lacquer layer. For doing this stone lapping process a special fixture, which is made of steel plate with slots to allow feet of dials placed easily, is used to give flat surface and equal load from back of the
> dial. This special fixture is steel plate fixture for holding the dials. This fixture
having the slots for holding the dials with its feet, as these slots are designed in
such a way that any type of feet calibre dials can be hold by this fixture. First the
dials are loaded on the steel fixture and then invert it on the stone lapping film.
Now the as the lapping starts m/c the movement of fixture will be in rotational
) motion on its axis opposite to the motion of the stone lapping film. This will cause a rubbing effect which in result helps us to remove the protective layer of the dials and exposing the brass from the required portion of the dials with the desired limit of height of index without variation.
[034] The special fixture is used to avoid variations in the index height within
> 0.02 - 0.04 mm which each was between 0.05-0.08 mm with normal foam pad.
Specialty in fixture in thin slots of some particular length which holds the feet of
dial while lapping.

[035] The invention provides lapping of induced stamped indexes with the use of special slotted fixture plates to allow the feet of watch dials for fitment purpose. Dials are fixed on fixture plate in turn lap the indexes on stone and then after on lapping film. The special slotted fixture helps in controlling thickness and flatness 5 variations.
[036] The grinding of crystals is done with a specific thickness with one size of abrasive. The lapping machine has four wheels. There is stone and velvet film in place of buffer which gives polish surface in particulate. It gives efficient double finish dial. Sun gear is used for lapping wheel mechanism. It has two planes, one plane clockwise another anticlockwise. One plane is vertical to horizontal, and index lapping, tool is vertical
[037] This device is used for the outer diameter of shaft. The device is doing horizontal plane with the help of special fixture
[038] For inducing galvanizing on the stamped index dials, indexes of stamped dial are to be lapped first by removing protective lacquer layer. For this stone lapping process a special fixture plate is used to give flat surface and equal load from back of the dial. This fixture is used to avoid variations in the index height with normal foam pad. There are thin slots of some particular length of 0.75 -0.85 mm thick see through slots, which is there is hold feet of dial while lapping.
[039] Lapping time and load on fixture is set on machine itself with which desired lapping thickness is achieved. Dials are fixed directly on special fixture, and also got removed with scalp tool carefully after lapping. The process includes following steps:
1. Set the machine parameters (lapping time and pressure on fixture) and load the dials manually on special fixture.
2. Invert the fixture upside down on stone lapping machine.

3. Start the lapping cycle. (Continuously turn on the water on lapping stone while processing the dials).
4. Unload the dials from fixture to grills carefully with the use of scalp tool.
5. Wash the dials with caustic solution.
6. Dry the dials in dryer at 60 °C to 80 °C temperature for 30-60 seconds
[040] Thus the present invention provides reduction is thickness variation, good quality lapping without shade and self-load bearing plate requires no machine pressure
[041] Numerous modifications and adaptations of the system of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the true spirit and scope of this invention.

WE CLAIM:
1. A system and method for dual color, dual finish lapping of stamped watch dial with index comprises lapping device, fixture for stone lapping characterized in that plate with slots to allow feet of dials placed easily, to give flat surface and equal load from back of the dial wherein indexes of stamped dial are to be lapped first by removing protective lacquer layer for inducing galvanizing on the stamped index dials, dials are fixed on fixture plate in turn lap the indexes on stone and then after on lapping film and grinding of crystals is done with a specific thickness with one size of abrasive
2. The system and method for dual color, dual finish lapping of stamped watch dial with index, as claimed in claim 1, wherein the lapping machine has four wheels, stone and velvet film in place of buffer which gives polish surface in particulate and gives efficient double finish dial, sun gear for lapping wheel mechanism.
3. The system and method for dual color, dual finish lapping of stamped watch dial with index, as claimed in claim 1, wherein the lapping machine has two planes, one plane clockwise another anticlockwise, one plane is vertical to horizontal, and index lapping, tool is vertical and the device is used for the outer diameter of shaft and doing horizontal plane with the help of special fixture
4. The system and method for dual color, dual finish lapping of stamped watch dial with index, as claimed in claim 1, wherein the thin slots are of length of 0.75 -0.85 mm thick see through slots, to hold feet of dial while lapping.
5. The system and method for dual color, dual finish lapping of stamped watch dial with index, as claimed in claim 1, wherein the fixture is used to avoid variations in the index height within 0.02 - 0.04 mm which each was between 0.05-0.08 mm with normal foam pad.

6. The system and method for dual color, dual finish lapping of stamped watch dial with index, as claimed in claim 1, wherein the fixture helps in controlling thickness and flatness variations.
7. The system and method for dual color, dual finish lapping of stamped watch dial with index, as claimed in claim 1, wherein the process includes following steps:

a) Set lapping time and pressure on fixture and load the dials manually on special fixture.
b) Invert the fixture upside down on stone lapping machine.
c) Start the lapping cycle and continuously turn on the water on lapping stone while processing the dials
d) Unload the dials from fixture to grills carefully with the use of scalp tool.
e) Wash the dials with caustic solution.
f) Dry the dials in dryer at 60 °C to 80 °C temperature for 30-60 seconds