Abstract:
An automatic picture tube cutting machine is provided. The machine includes a transporting mechanism for transporting a tray carrying a picture tube into a moving-up-and-down base, which automatically adjusts the vertical position of the picture tube based upon its size. The machine also includes a positioning and cutting device wherein a plurality of clamp units cooperatively set tungsten heating filaments in contact with the picture tube to circumscribe that picture tube at a preset cutting height. Upon heating via the tungsten heating filaments and subsequent cool water quenching, the picture tube is broken at its circumscribed portion into separated front and rear stages.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to an automatic picture tube cutting machine, particularly to one automatically feeding material, measuring the size of a picture tube, positioning and cutting the picture tube. 
   Nowadays, televisions have been widely used in homes, and a large number of them are discarded. Then it is very important to recycle luminescent powder painted in a picture tube, as luminescent powder is a material leading to grow cancer in a human body. Therefore, if it is not properly treated, it pollutes the environment to bring danger to people&#39;s health. 
   In treating old picture tubes of televisions and computers, a front stage containing barium glass is first to be cut off a rear stage of lead glass, and then luminescent powder painted on an inner surface of the glass is sucked off by means of vacuum process, and then collected to be sealed in a container. Then it is sent to a qualified waste treatment factory to be hardened. However, cutting picture tubes has been performed manually so far. 
   A conventional picture tube cutting machine has old discarded picture tubes manually carried and placed on a work table of the machine, and adjusting the correct position of a picture tube for a worker to wind tungsten filament around the jointed point of the front and the rear stage of a picture tube, with tungsten filament tightly pulled and secured its one end with a clamp, and then the tungsten filament is powered to heat up the glass of a picture tube for a certain period of time (about 2-3 minutes), making the glass inflate because of heating by the tungsten, and then spraying cool water to instantly cool and let the glass where wound with the tungsten filament break. Then the tungsten filament is removed and the rear stage lead glass is stowed away. After that a metal net inside the front stage glass is taken out and the luminescent powder painted on an inner wall of the glass is removed off by means of vacuum process and stored in a container. The front stage glass with luminescent powder completely removed is stowed away for future final treatment. 
   Manual cutting process of picture tubes just described has the following disadvantages. 
   1. Placing a picture tube on the work table is done completely by manual labor, it takes much time and work, especially in case of a heavy one, chances are that a picture tube may be broken by colliding with something hard carelessly, causing danger to workers.
         2. As picture tubes have various sizes, tungsten filament may have to be long enough for winding, and in addition, heating and cooling time may be different. So a worker should have some experience, or work efficiency may be low. And experienced workers may have to be paid high wages.       

   SUMMARY OF THE INVENTION 
   A first objective of the invention is to offer an automatic picture tube cutting machine, which includes a transporting tray for placing a picture tube on and a transporting machine to transport the tray in a moving-up-and down base. Then the base automatically moves up and adjusts the height of the picture tube to send it in a positioning and cutting device to let the picture tube to stay at a correct position for cutting, correcting the center point of the picture tube on the transporting tray by a clamp unit, letting the tungsten filaments of the cutting device closely contact the four sides of the picture tube. Then the tungsten filaments are electrified to heat up the picture tube for a set time and cool water is sprayed on the same tube with nozzles to cool the glass to break to cut off separately the front stage from the rear stage of the picture tube. After that the moving-up-and-down table is lowered down to send out the cut picture-tube, finishing cutting work. 
   Another objective of the invention is to offer an automatic picture tube cutting machine, which has a speed recorder to be touched by the transporting tray when the transporting tray is moved in the moving-up-and-down base. When the front stage of a picture tube passes a photoelectric sensor respectively located at two sides of the transporting machine, a PLC (programmable logic controller) controller begins to record until the whole picture tube completely passes through the photoelectric sensors, which may then stop. Thus, the moving-up-and-down base lifts up the picture tube to the needed height, in accordance to the distance and the size of the picture tube calculated by the speed recorder. 
   Another objective of the invention is to offer an automatic picture tube cutting machine having a recessed frame fitted in the center portion of the transporting tray so that the curved screen of the picture tube may just contact the upper circumferential edge of the recessed frame, at the same time permitting the cutting device to easily move the picture tube to correct its center point. 
   One more objective of the invention is to offer an automatic picture tube cutting machine, wherein the tungsten filaments at two sides of the clamp rods of the cutting device is respectively connected with a spring to enable the tungsten filament to closely and elastically contact the four sides of the picture tube. Then even if the tungsten filaments should be shortened to the shortest, the tungsten filament could cope with various size of a picture tube to be cut, making the most of the tungsten filaments. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     This invention will be better understood by referring to the accompanying drawings, wherein: 
       FIG. 1  is a front view of an automatic picture tube cutting machine. 
       FIG. 2  is a left side view of FIG.  1 . 
       FIG. 3  is an upper view of FIG.  1 . 
       FIG. 4  is an upper view of a transporting tray of the present invention. 
       FIG. 5  is a side view of the transporting tray of the present invention. 
       FIG. 6  is a part perspective view of a moving-up-and-down base of the present invention. 
       FIG. 7  is a perspective view of a position block of the present invention. 
       FIG. 8  is a side view of the position block of the present invention. 
       FIG. 9  is an upper view of the position block of the present invention. 
       FIG. 10  is a side view of an: operation of the automatic picture tube cutting machine, showing the transporting tray stopped by a first stop plate. 
       FIG. 11  is a front view of an operation of the automatic picture tube cutting machine, showing the transporting tray moving in the moving-up-and-down base. 
       FIG. 12  is a front view of an operation of the automatic picture tube cutting machine, showing the moving-up-and-down base lifted up. 
       FIG. 13  is an upper view of an operation of the automatic picture tube cutting machine, showing the positioning and cutting device making adjustment. 
       FIG. 14  is an upper view of an operation of the automatic picture tube cutting machine, showing the positioning and cutting device clamping and positioning a picture tube. 
       FIG. 15  is an upper view of an operation of the automatic picture tube cutting machine, showing a position block positioning a corner of the picture tube. 
       FIG. 16  is an upper view of an operation of the automatic picture tube cutting machine, showing nozzles spraying water. 
       FIG. 17  is an upper view of another embodiment of a linear bearing on a position rod of the present invention. 
       FIG. 18  is a side view of FIG.  17 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   A preferred embodiment of an automatic picture tube cutting machine in the present invention, as shown in  FIGS. 1 ,  2  and  3 , includes a machine frame  1 , a transporting machine  2 , a transporting tray  3 , a moving-up-and-down base  4  and a positioning and cutting device  5  as main components combined together. 
   The machine frame  1  has a preset height, a lateral rod  11 , a water tank  12  and a controller  13  placed on the lateral rod  11 , an upper flat plate  14  and a lower flat plate  15  below the lateral rod  11 , the positioning and cutting device  5  fixed on the upper flat plate  14 , the moving-up-and-down base  4  fixed on the lower flat plate  15 . The upper flat plate  14  has a center hole  141  for a moving-up-and-down plate  41  of the moving-up-and-down base  4  with a picture tube placed on the plate  41  to move up therein, a plurality of nozzles  142  are positioned on a circumferential edge, connected to the water tank  12 . The transporting machine  2  moves back and forth through a lower portion of the machine frame  1 . 
   The transporting machine  2  is installed in a lower portion of the machine frame  1 , moving between the moving-up-and down base  4  and the positioning and cutting device  5 , having plural rollers  21  spaced apart equidistantly at two sides, and the transporting tray  3  placed on the rollers  21 . Each roller  21  engages and rotates with a chain  23 , which is pulled to move by a power source  22 . When the rollers  21  rotate, the transporting tray  3  is moved forward. Further, a first stop unit  24  and a second stop unit  25  are respectively fixed at an intermediate portion of the transporting machine  2  and the exit of the moving-up-and-down base  4 . A first air pressure cylinder  241  and a second air pressure cylinder  251  are fixed on a frame of the transporting machine  2 , respectively having a piston rod extending up and fixed with a stop block  242 ,  252  having a micro switch  243 ,  253  on top. When the transporting tray  3  moves to touch the micro switches  243 ,  253 , the air pressure cylinders  241 ,  251  operate to move the piston rods to push tip the stop blocks  242 ,  252  to stop the transporting  10  tray  3 . 
   In addition, a speed recorder  26  is fixed below the transporting machine, and photoelectric switches  261 ,  262  are respectively fixed at two sides of an entrance of the moving-up-and-down base  4 , connected with the speed recorder  26 , which is also connected to a PLC controller and coder of the controller  13  to calculate the size of the picture tube passing the photoelectric switches  261 , 262 . 
   The transporting tray  3 , as shown in  FIGS. 4 and 5 , is sized just to locate between the rollers  21  at two sides of the transporting machine  2 , having a recess  31  in the center for the recessed frame  32  to fit therein. Then the outer surface of the screen of a picture tube is fit to the upper circumferential edge of the recessed frame  32  and positioned securely so as not to sway. The transporting tray  3  may thus easily move the picture tube to correct its center point. 
   The moving-up-and-down base  4  is fixed on the lower flat plate  15 , consisting of the moving-up-and-down plate  41 , a bead threaded rod  42 , plural guide rods  43 , a power source  44  and a position limit switch  45 . The transporting base  3  rests on the moving-up-and-down plate  41 , a shaft sleeve  411  is fixed at the bottom of the moving-up-and-down plate  41  to fit around the bead threaded rod  42 , and the four guide rods  43  extend down out of the four corners of the moving-up-and-down plate  41 . The bead threaded rod  42  can screw with a screw sleeve  421  combined in a bearing unit  422  fixed on the lower flat plate  15 , and at the same time a timing belt wheel  423  is placed on the threaded sleeve  421  to engage a timing belt  424  to connect with a transmitting timing belt wheel  441  of the power source  44  fixed at one side of the lower flat plate  15  to lift or lower the bead threaded rod  42  rotating in the threaded sleeve  421 . Further, a rotating disc  425  is fixed on an upper surface of the timing belt wheel  423  as shown in  FIG. 6 , having a plurality of through holes  426 . A magnetic sensor  427  fixed on the lower flat plate  15  at one side of the rotatable disc  425  extends about a portion of the rotatable disc  425  to sense the number of through holes  426  passing through the sensor  427  such that the vertical movement of the moving-up-and-down plate  41  to be lifted may be calculated. 
   Next, each guide rod  43  passes through a linear bearing  431  fixed on the lower flat plate  15 , and then extends downward. One of the guide rods  43  has an upper end and a lower end fixed with an upper and a lower stop block  432  and  433 , and an upper and a lower position limit switch  451  and  452  are respectively fixed on and under the lower flat plate  15 . Thus, when the upper stop block  432  or the lower stop block  433  touches the upper limit switch  451  or the lower limit switch  452  during rising or descending of the moving-up-and-down plate  41 , the upper position limit switch or lower position limit switch  452  immediately commands the machine to stop, preventing the moving-up-and-down plate  41  from rising too high or descending too low, and providing twofold protection of the device. 
   The positioning and cutting device  5  is disposed on the upper flat plate  14  of the machine frame  1 , and includes inner and outer clamp units  51  and  52  respectively located at inner side and outer side positions. The inner clamp unit  51  has threaded rod bases  511 ,  512  at two sides for supporting threaded rods  513 ,  514 , which respectively have two ends forming left and right threaded sections  5131 ,  5132 ,  5141 ,  5142  to engage respectively guide blocks  5133 ,  5134 ,  5143 ,  5144  on different sides. An inverted U-shaped position rod  515 ,  516  made of non-conductive bakelite is respectively fixed between two corresponding guide blocks  5133 ,  5143 ,  5134 ,  5144 , having micro switches  5151 ,  5161  set at intermediate portions thereof and springs  5152 ,  5162  fixed at two ends of the corresponding inner walls to connect to heating tungsten filaments  5153 ,  5163  to permit the tungsten filaments to effectively lengthen or shorten. 
   Further, the two threaded rods  513 ,  514  each have an end connected to a cross turner  517 , and between the two cross turners  517  extends a connect rod  518 , such that the movements of the two threaded rods  513 ,  514  are coupled one to the other. The connect rod  518  has large and small timing belt wheels  5181 ,  5182  respectively engaging a power source  53  and a position means  54  fixed on the upper flat plate  14  with timing belts  5183 ,  5184  to move nearer or farther away from each other the two position rods  515 ,  516 , and the position means  54  regulates the maximum position in expansion or contraction. 
   The outer clamp unit  52  has almost the same structure as the inner clamp unit  51 , having threaded rod bases  521 ,  522  respectively at two sides, but located not in line with the threaded rod bases  511 , 512  of the inner clamp unit  51 , and threaded rods  523 ,  524  supported respectively on the threaded rod bases  521 ,  522 . The threaded rods  523 ,  524  have left and right threaded sections  5231 ,  5232 ,  5241 ,  5242  formed in two ends to engage respectively guide blocks  5233 ,  5234 ,  5243 ,  5244  on different sides. Position rods  525 ,  526  made of non-conductive bakelite are respectively fixed between two corresponding guide blocks  5233 ,  5234 ,  5243 ,  5244 , permitting the two position rods  525 ,  526  to cross the position rods  515 ,  516  of the inner clamp unit  51  to form a rectangularly crossed configuration. Micro switches  5251 ,  5261  are respectively fixed at inner walls of intermediate portions of the two position rods  525 ,  526 , and springs  5252 ,  5262  are respectively placed in the inner corresponding ends of the position rods  525 ,  526  to connect heating tungsten filaments  5253 ,  5263  to expand or contract. The two threaded rods  523 ,  524  each have an end connected to a cross turner  527 , and between the two corresponding cross turners  527  is connected a connect rod  528  to permit the two threaded rods  523 ,  524  to be mutually connected to move synchronously. The connect rod  528  has large and small timing belt wheels  5281 , 5282  fixed on and engaged with a power source  55  and a position means  56  by means of timing belts  5283 ,  5284 . Then the two position rods  525 ,  526  may move nearer or farther away from each other when the power source operates, and the position means  56  regulates the maximum position of expansion and contraction. 
   Further, four position blocks  57  are fixed at four corners of the crossing position rods  515 ,  516 ,  525 ,  526 , having the same structure of an L shape, as shown in  FIGS. 7 ,  8  and  9 , and a support plate  571  is connected with an upper surface and a bottom surface. Each support plate  571  has a linear bearing  572  fixers on the bottom surface for engaging a corresponding one of the position rods  515 ,  516 ,  525 ,  526 . Each linear bearing  572  is securely coupled to a position rod  515 ,  516 . Then each position block  57  moves nearer to the center of the machine body or further away when each position rod moves. Each position block  57  is grooves  573 ,  574  in upper and lower sides of two ends for the tungsten filaments  5153 ,  5163 ,  5253 ,  5263  to pass through. 
   In cutting a picture tube, first, a picture tube T is placed on the transporting tray  3 , which is then moved forward by the transporting machine  2 . When the front side of the transporting tray  3  touches the micro switch  243  of the first stop unit  24  of the transporting machine  2 , the air pressure cylinder  241  moves its piston rod and subsequently the stop block  242  extends upward to stop the transporting tray  3 , as shown in  FIG. 10 , waiting for command from the controller. When the controller notifies that a material has arrived, the stop block  242  moves down to let the transporting tray  3  move forward to enter the moving-up-and-down base  4 . Then when a second transporting tray  3  behind the first one touches the micro switch  243 , the stop block  242  of the first stop unit  24  at once rises to stop the second transporting tray  3  to let it wait. 
   The transporting tray  3  touches the speed recorder  26  below the transporting machine  2  before the transporting tray  3  enters the moving-up-and down base  4 , and the speed recorder  26  sends out the distance signal to pass over. When the transporting tray  3  enters the moving-up-and-down base  4  and the front side of the picture tube on the base  4  touches the photoelectric switches  261 ,  262 , the PLC controller of the controller  13  and the coder begin to record data sent from the speed recorder  26  until the picture tube totally passes through the photoelectric switches  261 ,  262 , calculating accurately the size of the picture tube depending on the distance signal sent by the speed recorder  26  so that the controller  13  may decide the parameters needed for cutting (such as the height, the heating current, heating time and frequency of spraying). 
   When the picture tube on the transporting tray  3  enters the moving-up-and-down base  4 , the transporting tray  3  touches the micro switch  253  of second stop plate unit  25  to activate the air pressure, cylinder  251  to move up the stop block  252  to stop the transporting tray  3 . Subsequently the power source  44  of the moving-up-and-down base  4  starts to rotate the bead threaded rod  42  to lift quickly the moving-up-and down plate  41  according to the parameter of the height to be lifted, as shown in FIG.  12 . When the bead threaded rod  42  rotates, the rotating disc  425  is rotated to accurately position the height of the picture tube with cooperation of the magnetic sensor  427  sensing passing condition of the through holes  426  of the rotating-disc  425  and calculate the height to be lifted. As the moving-up-and-down base  4  begins to rise up, the position rods  515 ,  516 ,  525 ,  526  of the inner and the outer clamp units  51 ,  52  of the positioning and cutting device  5  and the heating tungsten filaments  5153 ,  5163 ,  5253 ,  5263  move forward to the set position in advance to reduce work time. 
   After the moving-up-and-down base  4  lifts the transporting tray  3  with the picture tube to the preset height for cutting, the power sources  53 ,  55  of the inner and the outer clamp units  51 ,  52  operate to rotate the threaded rods  513 ,  514 ,  523 ,  524  at four sides to move the position rods  515 ,  516 ,  525 ,  526  as shown in  FIG. 13  toward the center of the picture tube. Should the picture tube be not positioned correctly to bias to any side during placing the picture tube on the transporting tray  3  or transporting process, the position rods may touch the end not correctly positioned to move the picture tube to the other side because of the springs of the heating tungsten filaments until the position rod at the other side touches the picture tube. In other words, when the micro switches  5151 ,  5161 ,  5251 ,  5261  of the positions rods  515 ,  516 ,  525 ,  526  all touch the picture tube, as shown in  FIG. 14 , that means the picture tube is positioned in the center and stopped. 
   When the position rods  515 ,  516 ,  525 ,  526  adjust the picture tube to the center, the heating tungsten filaments  5153 ,  5163 ,  5253 ,  5263  are extensible and shrinkable and the picture tube is circular at four sides, the heating tungsten filaments may closely contact the four sides of the picture tube, with the position blocks  57  of the position rods  515 ,  516 ,  525 ,  526  tightly contacting the four corners of the picture tube, as shown in FIG.  15 . Then current can be turned on into the heating tungsten filaments for a preset period of time and then cut off, and the position rods  515 ,  516 ,  525 ,  526  together with the tungsten filaments  5153 ,  5163 ,  5253 ,  5263  are all retreated outward. Then the nozzles  142  spray cool water as shown in  FIG. 16 , letting the glass of the picture tube swiftly cool down to break at the heated position, and the front stage glass is cut off the rear stage glass of the picture tube. After that, the moving-up-and-down base  4  brings the cut picture tube down on the transporting machine  2  to be transported out and begin next process of material separation and sucking off luminescent powder. When the first transporting tray  3  is sent out, the second transporting tray  3  waiting will enter the moving-up-and-down base  4  for next cutting process. 
   Further, as shown in  FIGS. 17 ,  18 , a fix plate  58  is fixed on each linear bearing  572  respectively located at four crossing corners of the position rods  515 ,  516 ,  525 ,  526 , and a high roller  581  and a lower roller  582  are combined on the fix plate  58 , having an annular groove  5811 ,  5821  for the tungsten filaments  515 ,  516 ,  525 ,  526  to fit in. When the picture tube is adjusted to the center, the rollers  581 ,  582  rest against the four corners of the picture tube to let the tungsten filaments closely contact the four corners of the picture tube. 
   As can be understood from the aforesaid description, the automatic picture tube cutting machine in the invention has the following advantages.
         1. This machine accurately calculates the size of a picture tube passing through with the speed recorder and the photoelectric switches and operation of the coder and the PLC controller, and then decides the time needed for heating, heating temperature, the best height for cutting by making use of various data got from the components.   2. The position rods of the positioning and cutting device move a picture tube, and with help of the position blocks of the position rods, permitting the extensible and shrinkable tungsten filaments to closely contact the four sides of the picture tube, which is adjusted correctly in the center for cutting.   3. The recessed frame of the transporting tray can not only keep a picture tube placed therein not liable to slide out of the transporting tray, but the circumferential edge of the recessed frame contact the screen of a picture tube by means of linear contact, so even a light force can move the picture tube easily to adjust its position.   4. The heating tungsten filaments are connected with springs at two ends so as to have extensible and shrinkable capacity to be adapted to various sizes of picture tubes to stabilize the current passing therethrough.