Abstract:
An eyeglass lens processing apparatus for processing a periphery of an eyeglass lens, includes: a processing chamber in which a lens processing tool is disposed, the processing chamber having a drainage port; a water supply unit which supplies water for lens processing to an interior of the processing chamber; a drainpipe connected to the drainage port; a sensor which detects an amount of the water within the processing chamber or the drainpipe; and a controller which controls the water supply unit based on a result of detection by the sensor.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an eyeglass lens processing apparatus for processing a periphery of an eyeglass lens. 
     In an apparatus for processing a periphery of an eyeglass lens, a rotating grindstone (a processing tool) is caused to press against the periphery of the lens held on a lens rotating shaft in contact therewith, thereby carrying out the processing. During the processing, water for the processing is supplied in order to cool a portion of the lens to be processed and to remove processing wastes. For this reason, the grindstone is provided on the inside. Therefore, a processing chamber is protected by a waterproof cover for the processing. The used water is discharged through a drainage such as a drainpipe from a drainage port provided in a lower part of the processing chamber. 
     However, the conventional apparatus suffers from the following problem. More specifically, when the drainage such as a drainage port or a drainpipe is clogged with processing wastes, the water is not discharged but the processing chamber overflows with the water. Consequently, the apparatus breaks down. In order to eliminate such a drawback, a cleaning work for removing the processing wastes is to be carried out at any time and management therefor cannot be performed easily. 
     SUMMARY OF THE INVENTION 
     In consideration of the drawbacks of the conventional apparatus, it is a technological object of the invention to provide an eyeglass lens processing apparatus capable of preventing a water overflow due to the clogging of the drainage, and furthermore, of easily managing a cleaning work for removing processing wastes. 
     In order to attain the object, the invention has the following structure. 
     (1) An eyeglass lens processing apparatus for processing a periphery of an eyeglass lens, comprising: 
     a processing chamber in which a lens processing tool is disposed; 
     water supply means for supplying water for lens processing to an interior of the processing chamber; 
     water drainage means for discharging the water from the processing chamber; 
     detect means for detecting a clogging state of the water drainage means; and 
     water supply control means for controlling supply of the water by the water supply means based on a result of detection by the detect means. 
     (2) The apparatus according to (1), further comprising: 
     notifying means for notifying the result of detection by the detection means. 
     (3) The apparatus according to (1), wherein the detect means detects an amount of the water within the processing chamber. 
     (4) The apparatus according to (1), wherein: 
     the water drainage means includes a drainage port provided to the processing chamber and a drainpipe connected to the drainage port; and 
     the detect means detects an amount of the water within the drainpipe. 
     (5) The apparatus according to (1), further comprising: 
     process control means for controlling the lens processing by the lens processing tool based on the result of detection by the detect means. 
     (6) An eyeglass lens processing apparatus for processing a periphery of an eyeglass lens, comprising: 
     a processing chamber in which a lens processing tool is disposed, the processing chamber having a drainage port; 
     a water supply unit which supplies water for lens processing to an interior of the processing chamber; 
     a drainpipe connected to the drainage port; 
     a sensor which detects an amount of the water within the processing chamber or the drainpipe; and 
     a controller which controls the water supply unit based on a result of detection by the sensor. 
     (7) The apparatus according to (6), further comprising: 
     a notify unit which notifies the result of detection by the sensor. 
     (8) The apparatus according to (6), wherein the controller controls the lens processing by the lens processing tool based on the result of detection by the sensor. 
     (9) An eyeglass lens processing apparatus for processing a periphery of an eyeglass lens, comprising: 
     a processing chamber in which a lens processing tool is disposed; 
     water supply means for supplying water for lens processing to an interior of the processing chamber; 
     water drainage means for discharging the water from the processing chamber; 
     detect means for detecting a clogging state of the water drainage means; and 
     notifying means for notifying the result of detection by the detection means. 
     The present disclosure relates to the subject matter contained in Japanese patent application No. 2000-401369 (filed on Dec. 27, 2000), which is expressly incorporated herein by reference in its entirety. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing a whole lens processing apparatus; 
     FIG. 2 is a view showing a schematic structure of a processing section; 
     FIG. 3 is a view showing a schematic structure of the whole lens processing apparatus; and 
     FIG. 4 is a view showing a schematic structure according to a variant. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of the invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a whole lens processing apparatus according to the invention. The processing apparatus is mainly constituted by a body  1 , a table  10  for mounting the body  1  thereon, and a tank section  200  for water storage which is provided in the table  10 . 
     An eyeglass-frame-shape measuring section  2  is provided in the upper and right inner portion of the body  1 . A display  3  for displaying processing information and a panel  4  having a large number of switches for an operation are provided in front of the measuring section  2 . The reference numeral  5  denotes an openable window for a processing chamber  161  (see FIG. 3) provided in the body  1 . 
     The schematic structure of a processing section  100  provided in the body  1  will be described with reference to FIG.  2 . The reference numeral  101  denotes a base on which the processing section  100  is to be mounted. A lens LE to be processed is held by two lens rotating shafts  111 R and  111 L of a carriage  110  and is ground by means of a grindstone  151  attached to a grindstone rotating shaft  150 . The grindstone  151  is constituted by three grindstones, that is, a rough abrasive wheel for plastic lenses, a rough abrasive wheel for glass lenses and a finishing abrasive wheel having a groove for beveling processing and a flat surface for flat processing. The shaft  150  is rotated by a motor  153  so that the grindstone  151  is rotated. 
     A block  114  for attaching a motor which is rotatable about an axis of the shaft  111 L is fixed to the left arm side of the carriage  110 . A motor  115  for lens rotation is fixed to the block  114  and the rotation of the motor  115  is transmitted to the shaft  111 L through a gear. A right arm of the carriage  110  is provided with a motor  112  for a chuck which serves to move the shaft  111 R in an axial direction thereof. 
     Moreover, the carriage  110  is rotatably slidable with respect to a carriage shaft  120  in parallel with the shafts  111 R and  111 L and is moved in a transverse direction together with a moving arm  121  by means of a motor  122 . 
     A swingable block  130  is rotatably attached to the arm  121  about an axis which is in alignment with the center of the shaft  150 . A motor  131  for carriage elevation and a feed screw  132  are attached to the block  130 , and the rotation of the motor  131  is transmitted to the screw  132  through a belt. A guide block  133  which abuts against a lower end surface of the block  114  is fixed to an upper end of the screw  132 , and the guide block  133  moves along two guide shafts  135  implanted on the block  130 . When the motor  131  is rotated, the vertical position of the guide block  133  can be changed and the carriage  110  can be vertically moved by setting the carriage shaft  120  to be a center of rotation through the movement of the guide block  133 . A spring which is not shown is stretched between the carriage  110  and the arm  121  and the carriage  110  is constantly urged downward so that the lens LE is pushed against the grindstone  151 . 
     FIG. 3 is a view showing the schematic structure of a whole processing apparatus. A processing chamber  161  is formed by a waterproof cover  160  formed of resin in such a configuration that the lens LE held by the shafts  111 R and  111 L and the grindstone  151  are surrounded. The processing chamber  161  is separated from a mechanism section such as a motor through the cover  160 . A nozzle  162  for jetting water for processing is extended into the processing chamber  161  and is connected to a circulating pump  210  of the tank section  200 . During the processing of the lens LE, the water is jetted from the nozzle  162  and the jetted water and processing wastes are received by the cover  160 . 
     An electrostatic capacity type sensor  170  for detecting that the water is accumulated in the processing chamber  161  is provided in the vicinity of the lower external wall of the cover  160 . The sensor  170  detects an object by utilizing the fact that a conductive object approaches an electrode surface thereof to increase an electrostatic capacity between the electrode surface and the object. More specifically, the sensor  170  detects, through the cover  160 , that the conductive water is accumulated in the processing chamber  161 . Preferably, the water jetted from the nozzle  162  splashes on the cover  160  portion provided with the sensor  170  as less as possible. 
     A drainpipe (a drainage hose)  201  is connected to a drainage port  160   a  provided in a lower part of the cover  160  (the processing chamber  161 ), and the drainpipe  201  is extended into a tank  202  for water storage on the tank section  200  side. The pump  210  is attached to a lid  203  of the tank  202  and a water sucking pipe  211  of the pump  210  is extended into the tank  202 . The reference numeral  212  denotes a filter attached to the tip of the water sucking pipe  211 . The water taken through the water sucking pipe  211  by driving the pump  210  is supplied to the nozzle  162  on the body  1  side. Moreover, a removable filter  205  which is also used as a bag for collecting the processing wastes is attached to the tip of the drainpipe  201  extended into the tank  202 . 
     The reference numeral  180  denotes a control section of the body  1 . The sensor  170 , the pump  210 , the measuring section  2 , the display  3 , the panel  4  and each motor of the processing section  100  are connected to the control section  180 . 
     In the processing, necessary data such as a frame shape measured by the measuring section  2  or layout data are input to chuck the lens LE into the rotating shafts  111 R and  111 L. When a processing start switch of the panel  4  is pushed to start the processing, the lens LE is pressed against the grindstone  151  in contact therewith by the movement of the carriage  110  and a peripheral edge thereof is processed based on the input data. During the processing, the pump  210  is driven and the water stored in the tank  202  is supplied from the nozzle  162  to the processing portion of the lens LE. The processing wastes generated during the processing and the water are received by the cover  160 , and the water is discharged to the tank section  200  side through the drainage port  160   a  and the drainpipe  201 . The water is filtered by means of the filter  205  and is supplied to the body  1  side again. 
     By repeating such processing, the processing wastes are accumulated in the filter  205 . When the filter  205  is clogged, the water is discharged from the drainpipe  201  with difficulty. For this reason, a water level in the drainpipe  201  is raised so that the water is also accumulated in the processing chamber  161 . When the level of the water accumulated in the processing chamber  161  reaches a height of arrangement of the sensor  170  (the water level becomes higher than the height of arrangement of the sensor  170 ), the sensor  170  detects that the water is accumulated. More specifically, when the water is accumulated in the processing chamber  161 , a conductive object becomes present so that an output signal of the sensor  170  is changed. The output signal of the sensor  170  is input to the control section  180  and the control section  180  detects, based on a change in the signal, that the water is accumulated. 
     The control section  180  immediately stops the driving operation of the pump  210  to halt the water supply based on the result of the detection, and drives the motor  131  for vertically moving the carriage  110 , thereby temporarily stopping the processing operation. At the same time, the display  3  is caused to display a message indicating that the processing wastes are to be cleaned. Consequently, a worker knows that cleaning and inspection are required. Therefore, the worker removes the cause of the clogging. After the cause of the clogging is removed, the processing start switch of the panel  4  is pushed to restart the processing. 
     FIG. 4 is a view showing a schematic structure according to a variant of the invention. The same elements as those in FIG. 3 have the same reference numerals and description thereof will be omitted. 
     In the example shown in FIG. 4, means for detecting that the drainage is clogged is provided in the middle of the drainpipe  201 . A pipe (a hose)  231  is connected to branch through a connecting member  230  in the middle of the drainpipe  201 . The pipe  231  is attached slightly upward from a connecting portion. The tip of the pipe  231  is connected to a small tank  233  and the small tank  233  is put on a middle plate  10   a  in the table  10 . A float  235  floating on the water is provided in the small tank  233  and a switch  236  for detecting the floating state of the float  235  is provided on the small tank  233 . 
     When the water is not discharged from the tip of the drainpipe  201  due to the clogging of the filter  205 , the water level is raised so that the water flows into the small tank  233  side through the branching pipe  231 . When the water flows into the small tank  233  so that the level thereof is raised, the float  235  floats and the floating is detected by a switch  236 . An output signal of the switch  236  is input to the control section  180  and the control section  180  stops the water supply through the pump  210  and separates the lens LE from the grindstone  151 , thereby temporarily interrupting the processing in the same manner as in the above example. Moreover, the display  3  is caused to display the message described above. 
     In some cases, a drainage cover having a large number of small holes is provided in the drainage port  160   a  in order to prevent the lens LE failing to be removed from flowing downward into the tank  202 . In these cases, the drainage cover provided in the drainage port  160   a  is apt to be clogged with the processing wastes. Therefore, it is preferable that the means for detecting that the drainage is clogged should be provided on the processing chamber  161  side as in the above example. Also in such a structure that the float  235  and the switch  236  shown in FIG. 4 are used, it is a matter of course that they can be provided on the processing chamber  161  side. 
     While the circulating method using the pump  210  and the tank  202  has been taken as an example of the water supply method in the embodiment described above, the invention can also be applied to the case of a water supply direct connecting method. 
     Moreover, while the lens processing is carried out by means of the grindstone in the embodiment, another processing tool (an end mill) may be used. Furthermore, it is also possible to give, in a voice, a notice that the processing wastes are to be cleaned. 
     As described above, according to the invention, it is possible to prevent a water overflow from being caused by the clogging of the drainage. Moreover, the apparatus gives a notice that the drainage is clogged. Therefore, routine cleaning can be managed easily.