JPH085001B2 - Jade machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is capable of adjusting the lens clamping force of a clamp mechanism that is driven by a motor or power such as air pressure or hydraulic pressure to hold a lens to be processed. It is about.

(Prior Art) Conventionally, a ball shaving machine is provided with a pair of lens rotating shafts arranged in parallel with the axis of the grinding wheel so that the lens rotating shafts can be relatively moved toward and away from each other, and the pair of lens rotating shafts are integrally formed. There is a grinding wheel that can be freely moved back and forth. In this ball slicing machine, a circular lens to be processed is clamped (clamped) between a pair of lens rotating shafts facing each other, and while the lens rotating shaft is being rotated, the grinding wheel is moved back and forth to control the workpiece. By grinding the lens with a grinding wheel, the peripheral edge of the lens to be processed is ground into a predetermined shape (lens frame of the eyeglass frame).

In such a ball slicing machine, as a method of clamping the lens to be processed by adjusting the relative approach and separation of the pair of lens rotation shafts, the operator operates the feed screw with the handle to move the lens that interlocks with the feed screw. A manual operation method in which one of the rotary shafts is moved back and forth with respect to the other, and a power operation in which one of a pair of lens rotary shafts is controlled to move forward and backward with respect to the other by driving means such as a motor, an air cylinder, and a hydraulic cylinder. There are two types of methods.

Of these two clamp operation methods, the manual operation method is generally used, but in recent years, the power operation method tends to be used.

Moreover, in such grinding of the lens to be processed, a template corresponding to the shape of the lens mounting portion of the spectacle frame is attached to one of the pair of lens rotation shafts, and the template is brought into contact with the die holder. Then, by grinding the peripheral portion of the lens to be processed while rotating the lens rotation axis,
A circular lens to be processed is ground into the same shape as the template.
The template is held by the lens rotation shaft at the center.

When the lenses processed in this way are attached to the left and right lens mounts of the spectacle frame, the distance between the optical axes of the left and right lenses must match the PD of the human eye (the distance between the pupils of the left and right eyes). .

On the other hand, in the fashion of eyeglass frames in recent years, the size of the lens frame of the eyeglass frame tends to increase, and the lens tends to increase accordingly. However, even if the size of the lens is increased in this way, the PD of the human eye (the distance between the pupils of the left and right eyes) does not change, so the geometric center distance between the left and right lens frames of the eyeglass frame is the distance between the optical axes of the left and right lenses. Will be larger than. As a result, the optical axis of the lens and the geometric center of the lens frame deviate, and the amount of this deviation tends to increase as the lens aperture increases.

When grinding such a large-diameter lens, it is necessary to sandwich it between a pair of lens rotation axes at a position separated from the optical axis of a circular lens to be processed by a predetermined distance. In addition, the grinding amount of the lens to be processed sandwiched between the lens rotation axes in this manner is larger in the portion corresponding to the nose of the spectacle frame than in the other portions. Moreover, this tendency becomes more remarkable as the diameter of the lens increases.

In addition, during such grinding of the peripheral edge of the lens to be processed, a moment due to grinding resistance acts as a relative rotational force on the holding portion of the lens rotation axis of the lens to be processed, and the lens to be processed and the lens rotation axis are moved. Try to rotate relative. This relative rotational force increases as the distance from the holding portion of the lens to be processed to the grinding position increases.

Therefore, the above-mentioned relative rotational force when processing a lens having a large diameter becomes the largest at the time of grinding the portion of the lens located on the nose side of the eyeglass frame, and becomes larger as the diameter of the lens becomes larger.

Further, since the thickness of the lens to be processed is changed from the center side toward the peripheral edge side, when the lens to be processed is held between the lens rotation shafts at a position distant from the center in the radial direction, the lens rotation shaft It is necessary to make the direction of the lens holding end of (1) correspond to the direction of the surface of the held portion of the lens.

Therefore, conventionally, a lens suction plate as a holding portion is attached to one of the opposite ends of a pair of lens rotation shafts, and a lens pressing member as a holding portion is provided on the other of the opposite ends by a spherical bearing. A lens to be processed is held between the lens suction plate and the lens pressing member by holding the lens so that it can be tilted in any direction and cannot be relatively rotated about the axis. Moreover, the lens pressing portion can be fixed in any direction with respect to the lens rotation axis by a small frictional force acting on the spherical bearing, and can be rotated in any direction by a small force.

However, when the lens pressing member receives a pressing force in the axial direction of the lens rotating shaft during clamping of the lens to be processed by the lens rotating shaft, the friction locking force acting on the spherical bearing increases, and the lens pressing member is There may occur a state where the lens cannot be rotated depending on the direction of the surface of the held portion of the lens to be processed.

Moreover, in this case, since the pressing force of the lens pressing member against the lens to be processed, that is, the clamping force is not uniform in the entire contact portion, the lens to be processed cannot be reliably clamped between the lens fixing shafts.

As a result, when the lens clamping force of the lens is uneven as described above during processing of a large-diameter lens in which the relative rotational force acting on the lens holding portion is increased, the axis of the lens to be processed and the lens rotation axis is increased. There is a possibility of deviation, and in this case, there is a problem that the lens cannot be processed into a predetermined shape or the optical axis of the lens is displaced.

Therefore, an object of the present invention is to provide a ball-sliding machine which does not cause the above-mentioned uneven clamping force when holding the lens to be processed between the pair of lens rotation shafts.

(Means for Solving the Problems) In order to achieve this object, the present invention provides a pair of lens rotation shafts that are coaxially arranged in series and that are driven to relatively approach / separate in the axial direction by a driving means, A lens suction plate is attached to one of the opposite ends of the pair of lens rotation shafts,
While having a lens pressing member on the other of the opposite ends,
A ball-sliding machine, wherein the pair of lens rotation shafts are relatively brought close to each other by the driving means to perform a clamping operation for sandwiching the lens to be processed between the lens suction plate and the lens pressing member, After the clamping operation, the pair of lens rotary shafts are slightly separated from each other, and then the control unit is provided for controlling the clamping operation to be released.

(Operation) According to such a configuration, when the lens to be processed is clamped between the lens rotation axes, the clamping operation is performed twice.

(Examples) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a ball shaving machine according to the present invention.

In FIG. 1, reference numerals 1 and 2 are lens rotation shafts as lens holding shafts. The axes of the lens rotation shafts 1 and 2 are aligned with each other, and the lens rotation shaft 1 is rotatable at a predetermined position of a carriage (not shown). Held in. The carriage is mounted on the main body so that the lens rotation shafts 1 and 2 can move up and down with respect to a grinding wheel of the main body (not shown) and can move in the axial direction. This structure is well known and will not be described.

A slot 3 extending in the axial direction and penetrating in the diametrical direction is formed in an intermediate portion of the lens rotation shaft 2. A timing gear 4 is held on the carriage so as to be rotatable about the axis of the lens rotation shaft 2, and a feed female screw cylinder 5 whose axis is aligned with the lens rotation shaft 2 is fixed. .

Moreover, the lens rotation shaft 2 is the bearing portion of the timing gear 4.
A key 6 slidably fitted in the bearing 4a and fixed to the bearing 4a is inserted into the slot 3 movably in the axial direction. A timing belt 7 meshes with the timing gear 4. A timing gear (not shown) is fixed to the lens rotation shaft 1, and a timing belt (not shown) is also meshed with the timing gear. And
The timing belt and the timing belt 7 (not shown) are synchronously driven in the same direction by a rotation driving means (not shown). This allows the lens rotation axis
1, 2 are rotated in the same direction at the same speed.

An annular groove 8 extending in the circumferential direction is formed at the end of the lens rotation shaft 2 on the side opposite to the lens rotation shaft 1.
A feed male screw cylinder 9 is screwed therein, and pins 10, 10 projecting from the inner surface of one end of the feed male screw cylinder 9 are engaged with the annular groove 8.

By thus supporting the lens rotation shaft 2 on the timing gear 4 and the feed male screw cylinder 9, the lens rotation shaft 2
Is rotatably and axially held by the carriage as indicated by arrow A.

One end of a drive shaft 11 is fixed in the other end of the feed male screw cylinder 9, and a slot 12 penetrating in the diametrical direction and extending in the axial direction is formed in the other end of the drive shaft 11. There is. A drive gear 13 is fitted to the outer periphery of the drive shaft 11 on the other end side so as to be movable in the axial direction, and a key 14 integrally provided on the inner peripheral surface of the drive gear 13 is inserted into the slot 12. ing. As a result, the drive gear 13 is provided so as not to be rotatable relative to the drive shaft 11 and movable in the axial direction. Moreover, this drive gear 13 is a worm gear.
The worm gear 15 is meshed with the worm gear 15 and is rotated by a DC motor 16 as a driving means.

Then, when the DC motor 16 is operated, the rotational driving force of the DC motor 16 causes the worm gear 15 and the drive gear 1 to rotate.
3, transmitted to the drive shaft 11 via the key 14, the feed male screw tube 9 is rotated, and the action of the screws of the feed male screw tube 9 and the feed female thread tube 5 causes the feed male screw tube 9 to move. The screw cylinder 5 is driven to move back and forth in the axial direction. Along with this movement, the lens rotation shaft 2 is moved in the axial direction together with the feed male screw cylinder 9 via the pins 10, 10.

Further, a shaft body 17 for mounting a lens holding member and a spherical bearing 18 that operates in the same manner as a universal joint are mounted at the opposite ends of the lens rotation shafts 1 and 2. A lens suction plate 19 made of rubber can be attached to the end surface of the shaft body 17.

As shown in FIGS. 1 and 2, the spherical bearing 18 includes a shaft body 20 which is removably attached to the lens rotation shaft 2 and is relatively non-rotatable in the axial direction, and a socket portion of the shaft body 20.
It has a hemispherical body 21 held by 20a. As shown in FIG. 3, the socket portion 20a of the shaft body 20 has a tapered recess 2
2 is formed, and a notch slit 23 that opens to the end face is formed. Further, the hemispherical body 21 is formed with a stepped recess 24 that opens to the end face, a screw insertion hole 25 is formed in the bottom portion 24a of the stepped recess 24, and a pin is formed on the peripheral surface of the hemispherical body 21.
26 are projected.

The hemispherical body 21 is engaged with the tapered recess 22 and the pin 26 is engaged with the notch slit 23. Due to the action of the pin 26 and the notch slit 23, the hemispherical body 21 cannot rotate in the circumferential direction of the shaft body 20 with respect to the shaft body 20. Moreover, the screw 28 inserted into the washer 27 is loosely inserted into the screw insertion hole 25 and screwed to the center of the bottom of the tapered recess 22. As a result, the hemispherical body 21 is held in the socket portion 20a, but the screw 28 and the washer 27
The holding state of the hemispherical body 21, that is, the tightening amount of the screw 28, has almost no play between the hemispherical body 21 and the socket portion 20a, and the axis of the hemispherical body 21 radiates with respect to the axis of the shaft 20. It is set so that it can be tilted in any direction. With such a configuration, the hemispherical body 21 is provided so as not to be relatively rotatable in the circumferential direction of the shaft body 20 and rotatable in any radial direction. A rubber lens pressing member 29 is fixed to the end surface of the hemispherical body 21.

The lens rotation shafts 1 and 2 and the driving mechanism thereof, the lens suction plate 19, the lens pressing member 29 and the holding mechanism thereof, and the like constitute a clamp mechanism CL of the lens L to be processed.

The above-mentioned DC motor 16 is driven and controlled by the control means, that is, the control circuit C described below.

The control circuit C includes a drive circuit 30 for the DC motor 16, and a plurality of circuits and switches (to be described later) for controlling the drive circuit 30.

The drive circuit 30 includes a DC power source 31, a first drive switch 32,
A second drive switch 33, a resistor R, etc. are provided. This first
The drive switch 32 has terminals 32a, 32b, 32c for wiring connection, and the second drive switch 33 has terminals 33a, 33b, 33 for wiring connection.
have c. The terminals of the first and second drive switches 32 and 33
32a and 33a are respectively connected to a pair of input / output terminals (not shown) of the DC motor 16. Also, the first drive switch
The terminal 32b of 32 is connected to the plus side of the DC power supply 31 and the terminal 33c of the second drive switch 33, and the terminal 32c of the first drive switch 32 is connected to the terminal 33b of the second drive switch 33.
A resistor R is connected between this terminal 33b and the negative side of the DC power supply 31.

Further, the control circuit C described above includes the clamp close switch 34,
Clamp open switch 35, start switch 36, timer 37,3
8. It has a judgment circuit 39, a processing control circuit 40, a comparator 41, a reference voltage generation circuit 42 and the like.

The ON signal of the clamp closing switch 34 is input to the first drive switch 32 and the judgment circuit 39, and the clamp opening switch 35
Is inputted to the second drive switch 33, and the ON signal of the start switch 36 is inputted to the second drive switch 33, the timer 38, and the judging circuit 39. This timer 37
The switch switching signal S1 output from the first drive switch
Machining start signal S2 input to 32 and output from timer 37
Are input to the processing control circuit 40, and the switch change signals S3 and S4 output from the timer 38 are input to the first and second drive switches 32 and 33, respectively. Further, the switch switching signal S5 output from the determination circuit 39 is input to the first drive switch 32, and the clock start signal S6 output from the determination circuit 39 is the timer.
The signal S7 that is input to 37 and output from the processing control circuit 40 is input to the determination circuit 39, the timer 38, and the second drive switch 33. Moreover, the signal S8 output from the comparator 41 is input to the determination circuit 39, and the plus side voltage V _IN of the resistor R is input to one of the pair of input terminals of the comparator 41.
The reference voltage V _V output from the reference voltage generation circuit 42 is input to the other of the input terminals. The reference voltage generation circuit 42 can arbitrarily adjust the reference voltage V _V.

When the DC motor 16 in the control circuit C is stopped, the terminal 32a of the first drive switch 32 is connected to the terminal 3 as shown in the figure.
It is set so that it is connected to 2c and the terminal 33a of the second drive switch 33 is connected to 33b. In this state, the pair of input / output terminals of the DC motor 16 are short-circuited, and the DC motor 16 is in the braking state.

Further, the first drive switch 32 is the clamp close switch 34.
ON signal from switch or switch signal S3 from timer 38
Then, the terminal 32a is switched and connected from the terminal 32c to the terminal 32b, while the switch switching signal S5 from the judgment circuit 39 is connected.
Alternatively, when the switch switching signal S1 from the timer 37 is received, the terminal 32a is switched and connected from the terminal 32b to the terminal 32c.

The second drive switch 33 is an ON signal from the clamp opening switch 35 or the start switch 36 or the processing control circuit 40.
When the signal S7 from the terminal 33a is received, the terminal 33a changes from the terminal 33b to the terminal 33b.
On the other hand, when the switch switching signal S4 from the timer 38 is received, the terminal 33a changes from the terminal 33c to the terminal 33b.
It is designed to be switched to and connected to.

The timer 37 starts timing when receiving the signal S6 from the determination circuit 39, and after timing for a predetermined time, switches the switch signal.
While inputting S1 to the first drive switch 32, grinding start signal
Input S2 to the processing control circuit 40.

When the timer 38 receives the signal S7 from the processing control circuit 40, it starts time counting, inputs a switch changeover signal S3 to the first drive switch 32 after counting a predetermined time, and then outputs a second signal.
A switch switching signal S4 is input to the drive switch 33.

When the determination circuit 39 receives the output signal S8 from the comparator 41, the other input immediately before receiving the output signal S8 is the ON signal from the clamp close switch 34 and the start switch 36.
A switch change signal to the first drive switch 32 by judging which of the ON signal and the signal S7 from the processing control circuit 40
Either S5 or the timing start signal S6 to the timer 37 is output. That is, in the determination circuit 39, when the other input immediately before receiving the signal S8 from the comparator 41, the clamp closing switch 34
If it is an ON signal from the switch drive signal S5, the switch drive signal S5 is output to the first drive switch 32.
To enter. On the other hand, in the determination circuit 39, the other input immediately before receiving the signal S8 from the comparator 41 is the start switch.
When it is the ON signal of 36 and the signal S7 from the machining control circuit 40, the signal S6 is output and this signal S6 is input to the timer 37.

The processing control circuit 40 includes drive units (not shown) of the ball-shaving machine,
For example, ON / OFF control of the grindstone rotation motor, forward / backward rotation control of the carriage movement motor, forward / backward rotation control of the range rotation axis rotation drive motor in the carriage, etc. are executed according to preset procedures.

 Next, the operation of the ball slide machine having such a configuration will be described.

First, as shown in FIG. 1, the suction plate 19 sucked by the lens L to be processed is mounted on the shaft body 17 of the lens rotation shaft 1. Next, when the clamp closing switch 34 is turned on, this ON signal is input to the first drive switch 32 and the determination circuit 39. When this ON signal is input to the first drive switch 32, the terminal 32
a is switched and connected from the terminal 32c to the terminal 32b, and the DC motor 16 is normally rotated in the clamping direction. As a result, the first clamping operation is started, that is, the lens rotation shaft 2 is moved to the lens L side to be processed. When the lens pressing member 29 comes into contact with and presses the lens L to be processed along with this movement, the lens L to be processed is clamped between the lens suction plate 19 and the lens pressing member 29. Due to this clamping, an overcurrent I flows in the drive circuit 30, and this overcurrent I increases as the clamping force increases. Moreover, the conduction current I increases the amount of voltage drop that occurs in the resistor R. Then, the voltage V _IN on the positive side of the resistor R due to this voltage drop is input to the comparator 41. The comparator 41 outputs the output signal S8 and inputs it to the determination circuit 39 when the input voltage V _IN becomes higher than the reference voltage V _V from the reference voltage generation circuit 42. On the other hand, this judgment circuit 39
When the ON signal is input from the clamp closing switch 34 as described above, the switch switching signal S5 is output and input to the first drive switch 32. As a result, the terminal 32a of the first drive switch 32 is switched and connected from the terminal 32b to the terminal 32c, and the DC motor 16 is short-circuited. Therefore, the DC motor 16 is braked and stopped. The reference voltage V _V of the reference voltage generation circuit 42 is set small so that the clamping force at the time of stop is sufficiently smaller than the clamping force required for machining.

Next, for grinding the peripheral portion of the lens L to be processed,
When the start switch 36 is turned on, this ON signal is input to the second drive switch 33, the timer 38, and the judgment circuit 39.

When the second drive switch 33 receives this ON signal, the terminal 33a is switched and connected from the terminal 33b to the terminal 33c, and the lens rotation shaft 2 is moved in the direction away from the lens L to be processed (clamp release direction). To be

On the other hand, when the ON signal of the start switch 36 is input to the timer 38, the timer 38 starts counting time. And the timer
38 outputs the switch switching signals S3, S4 after a predetermined time has elapsed from the start of the clocking, and the switch switching signals S3, S4 are output.
To the first and second drive switches 32 and 33, respectively. As a result, the terminal 32a of the first drive switch 32 is switched and connected from the terminal 32c to the terminal 32b, the terminal 33a of the second drive switch 33 is switched and connected from the terminal 33c to the terminal 33b, and the DC motor 16 is normally rotated. , The second clamp operation is started.

The time measured by the timer 38 at this time is such that the lens L to be processed is moved between the lens suction plate 19 and the lens pressing member 29 by the movement of the lens rotation shaft 2 in the clamp releasing direction by turning on the start switch 36. The time is set so that the lens rotation shaft 2 can be moved in a direction away from the lens L to be processed to such an extent that it does not come off.

In this way, after the lens L to be processed is once clamped between the lens suction plate 19 and the lens pressing member 29, the lens rotation shaft 2 is slightly driven in the unclamping direction, and the clamping operation is performed again, so that the temporary operation is temporarily performed. Even when the hemispherical body 21 is fixed to the tapered recess 22 by the friction locking force during the first clamping operation, and the lens pressing member 29 does not uniformly contact the pressed portion of the lens L to be processed, The hemispherical body 21 is moved in the tapered recess 22 by the second clamping operation, and the lens pressing member 29 is brought into uniform contact with the pressed portion of the lens L to be processed.

As described above, the clamping operation of the lens L to be processed is re-executed, the overcurrent I flows through the drive circuit 30, and when the overcurrent I exceeds the set value, the comparator is operated in the same manner as described above.
The signal S8 is output from 41 and input to the determination circuit 39. Here, since the ON signal from the start switch 36 is input to the determination circuit 39 immediately before the signal S8 is input, the determination circuit 39 outputs the clock start signal S6 and inputs it to the timer 37. As a result, the timer 37 starts clocking, outputs the switch changeover signal S1 and inputs it to the first drive switch 32, and outputs the machining start signal S2 and inputs it to the machining control circuit 40 after measuring the predetermined time. To do.

Then, when the switch switching signal S1 is input to the first drive switch 32, the terminal 32a of the first drive switch 32 is changed to the terminal 32b.
Is switched and connected to the terminal 32c, the DC motor 16 is short-circuited, and the DC motor 16 is braked. on the other hand,
When the processing start signal S2 is output and input to the processing control circuit 40, the processing control circuit 40 causes the drive units (not shown) of the ball-shaving machine to operate.
The grindstone rotation motor is operated to control the forward / reverse rotation of the carriage movement motor to move the carriage, and the rotation control of the lens rotation axis rotation drive motor in the carriage is performed to perform rough grinding of the lens L to be processed. Let it be done.

The time measured by the timer 37 until such processing control is started depends on the moment generated by the grinding resistance during grinding of the lens L to be processed.
The lens suction plate 19 and the lens pressing member 29 are set to a time period in which the clamping force of the lens L to be processed is sufficiently obtained so as not to rotate relative to.

Further, along with the above-described rough grinding, the processing control circuit 40 outputs the signal S7 and continues to input the signal S7 to the determination circuit 39, the timer 38, and the second drive switch 33 until the rough grinding of the lens L to be processed is completed. Then, when the rough grinding of the lens L to be processed is completed, the processing control circuit 40 stops outputting the signal S7. After such rough grinding is finished, finishing work is performed.

This finishing process is done by pressing the start switch 36 after finishing the rough grinding.
It is started by turning it on. Then, when the start switch 36 is turned on, the re-clamping operation is executed similarly to the above-described rough grinding, and when the re-clamping operation is completed, the processing start signal S2 is input from the timer 37 to the processing control circuit 40. It As a result, the processing control circuit 40 controls the operation for finishing, and when the finishing is finished, stops the operation of each drive unit (not shown) of the ball shaving machine.

After that, when the clamp opening switch 35 is turned on, the second drive switch 33 is switched and connected from the terminal 33b to the terminal 33c, the clamp release operation of the lens L to be processed is performed, and the lens L to be processed is moved to the lens suction plate 19. And the lens pressing member 29 can be removed.

(Effect of the Invention) As described above, the present invention is provided with a pair of lens rotary shafts that are coaxially arranged in series and that are driven to approach / separate in the axial direction by the drive means. A lens suction plate is attached to one of the opposite end portions of the lens suction plate, and a lens pressing member is provided on the other of the opposite end portions, and the pair of lens rotation shafts are brought relatively close to each other by the driving means, In a ball-sliding machine configured to perform a clamping operation for sandwiching a lens to be processed with a lens pressing member, the clamping operation is released after the pair of lens rotation shafts are slightly separated from each other after the clamping operation. Since the control means is provided to control so that the clamping operation can be re-executed after the clamping is released, the processed lens is held between the pair of lens rotation axes. In doing so, it is possible to avoid the occurrence of the uneven clamping force as described above.

Further, according to such a configuration, when the clamp closing switch is first operated, it is possible to clamp the lens to be processed with a clamping force that is sufficiently weak as compared with the clamping force required for processing. Therefore, in the power-assisted clamping method, in the sense of safety, even if there is a dangerous state such as pinching a hand, by releasing the first clamping force as described above, the operator's hand can be released. Even if it is accidentally sandwiched between the lens rotation axes, it will not be damaged significantly. Further, the greatest effect in this operation is that the aligning action is ensured by this first clamping operation when the fixing means for the prism lens is used.

Next, by opening the pair of lens rotation shafts by a small amount with the start switch and performing the clamping operation again, the opening amount between the lens rotation shafts should not be so large that the operator can reach. Needless to say, it is good in terms of safety because it can be controlled. Also, in the conventional case, when the clamp closing switch is operated, the operator operates the lens while supporting it with his / her hand, so that the lens may be forcibly rotated and force may be applied to the lens. Although it occurs, according to the present invention, the clamping operation can be performed in a state where the continuous lens L to be processed is released, so that the lens to be processed can be clamped in a state where no undue force is applied.

Further, since the lens to be processed arranged between the lens rotation axes is clamped by the lens suction plate made of rubber and the lens pressing member, the lens to be processed and the lens suction plate after finishing the rough grinding and before finishing. Also, a slight twisting force in the direction of rotation is generated between the lens pressing member and the lens pressing member due to grinding resistance during rough grinding. Moreover, if finishing is performed in this state, there is a possibility that an axial deviation (astigmatic axis) may occur in which the optical axis of the processed lens deviates. However, as in the present invention, in the case where the control circuit is set so that the clamp control operation of the motor is performed before the rough grinding of the lens to be processed and between the completion of the rough grinding and the start of the finishing processing. Since the re-clamping operation releases the torsional force accumulated in the lens suction plate and the lens pressing member at the time of rough grinding, it is possible to prevent the above-mentioned axial displacement from occurring during finishing.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a ball shaving machine according to the present invention. FIG. 2 is a side view showing the relationship between the spherical bearing and the lens pressing member shown in FIG. FIG. 3 is a sectional view taken along the line III-III in FIG. 1,2 ...... Lens rotation axis 16 ...... DC motor (drive means) 19 ...... Lens suction plate 39 ...... Lens pressing member C ...... Control circuit (control means) CL ...... Clamp mechanism L ...... Lens to be processed

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiro Watanabe 75-1 Hasunumacho, Itabashi-ku, Tokyo Tokyo Optical Instruments Co., Ltd. (72) Inventor Shigeki Kuwano 75-1 Hasunuma-cho, Itabashi-ku, Tokyo Tokyo Optics Machine Co., Ltd. (72) Inventor Yasuo Suzuki No. 75-1 Hasunuma-cho, Itabashi-ku, Tokyo Tokyo Optical Machine Co., Ltd. (56) Reference JP-A-59-209748 (JP, A) JP-A-58- 160051 (JP, A) JP-A-57-201160 (JP, A)

Claims (2)

[Claims] 1. A pair of lens rotary shafts which are coaxially arranged in series and which are driven to approach and separate relative to each other in the axial direction by a driving means, and a lens suction plate is provided at one of opposite ends of the pair of lens rotary shafts. And has a lens pressing member on the other of the facing ends, and the pair of lens rotation shafts are brought relatively close to each other by the driving means, so that the lens suction plate and the lens pressing member are processed. A ball shaving machine configured to perform a clamping operation for holding a lens, wherein the pair of lens rotation shafts are slightly separated from each other after the clamping operation and before the grinding of the lens to be processed is started to perform the clamping operation. A ball-slicing machine provided with a control means for controlling so as to release it. 2. The ball according to claim 1, wherein a lens pressing member is attached to the other of the facing ends by a spherical bearing so as to be tiltable in an arbitrary direction and not relatively rotatable in the axial direction. Sliding machine.