Abstract:
A machine or apparatus for polishing, especially adapted for polishing fiber optic connectors and similarly configured industrial components. The polishing apparatus includes a first stage having a first mounting member and a first staging member supported on the first mounting member for reciprocal movement along a first path; a second stage having a second mounting member supported on the first staging member and a second staging member supported on the second mounting member for reciprocal movement along a second path in angular relation to the first path; a polishing member mounted on the second staging member; and a drive mechanism operable to simultaneously reciprocate the first and second staging members along their respective paths so that the polishing member traces a predetermined pattern. In operation, the apparatus reciprocates the first stage along its path and reciprocates the second stage along its path in a predetermined timed relationship so that the polishing member traces the predetermined pattern. The subject invention enables the polishing member to be moved along a uniform and constant figure eight polishing pattern, which pattern is mechanically created and maintained during the polishing action. The apparatus is suited for simultaneously polishing a large number of fiber optic connectors or similar items.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of my prior application No. 09/106,328, filed Jun. 29, 1998 now abandoned and entitled Process for Creating, by Mechanical Means, a Controlled Figure 8 Polishing Pattern for Use in the Manufacture and Operation of a Fiber Optic Connector Polishing Machine Capable of Simultaneously Polishing 12 to 36 Connectors and which is incorporated in its entirety by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention pertains to an apparatus or machine for polishing and more particularly to an apparatus for controlling the movement of a polishing member along a predetermined path. 
     BACKGROUND 
     Fiber optic connectors are required in large quantities in the telecommunications and cable television markets for the manufacture and use of fiber optic assemblies and components. In order to enable the connectors to provide the most optimum transmission path for the fiber optic cables, the ends of the connectors require special polishing. Current machines for polishing fiber optic connectors polish only in a circular pattern which does not produce the most effective polish. Moreover, the current polishers can polish no more than eighteen connectors at one time. 
     The art of polishing fiber optic connectors has been derived from the art of polishing gem stones. Basically, a gem stone polishing machine includes a rotating platter against which the gemstone is moved to effect polishing. This gemstone polishing technique was initially adopted for polishing fiber optic connectors and then subsequently modified. 
     The polishing surface in such gemstone polishing machines thus travels in a circular pattern, and the gemstone polishers modified to polish fiber optic connectors have likewise employed a circular pattern. 
     It is known, however, that a more effective polish can be obtained if the polishing surface travels in a figure eight pattern, rather than a circular pattern, as the polishing surface moves over the connector. The figure eight pattern, if it can be obtained and maintained during the polishing operation, provides the optimum method of polishing the end faces of fiber optic connectors. A constant figure eight pattern produces the best radii and apex shift obtainable on the spherical ends of the connectors and on similarly configured industrial components. 
     Not only is a circular pattern less effective in creating the desired polish on the connectors, it limits the number of connectors that can be polished at the same time. As shown in the Kawada U.S. Pat. No. 5,516,328, such a polisher rotates and revolves and thereby traces circular polishing paths that are revolved about a center. As a result the connectors must be located at the periphery in a circular formation with no connectors in the center, whereby fewer connectors can be polished than if the formation included connectors in the center. 
     SUMMARY 
     An apparatus or machine for polishing, especially adapted for polishing fiber optic connectors and similarly configured industrial components, is provided. The polishing apparatus includes a first stage having a first mounting member and a first staging member supported on the first mounting member for reciprocal movement along a first path; a second stage having a second mounting member supported on the first staging member and a second staging member supported on the second mounting member for reciprocal movement along a second path in angular relation to the first path; a polishing member mounted on the second staging member; and a drive mechanism operable to simultaneously reciprocate the first and second staging members along their respective paths so that the polishing member traces a predetermined pattern. In operation, the apparatus reciprocates the first stage along its path, and reciprocating the second stage along its path in a predetermined timed relationship so that the polishing member traces the predetermined pattern. The subject invention enables the polishing member to be moved along a constant and uniform figure eight polishing pattern, which pattern is mechanically created and maintained during the polishing action. The apparatus is suited for simultaneously polishing a large number of fiber optic connectors or similar items. 
     An object of this invention is to provide an optimum polishing pattern for polishing fiber optic connectors, or similar items. 
     Another object is to create and maintain a uniformly constant figure eight polishing pattern especially suited for polishing fiber optic connectors or similar items. 
     A further object is to provide a polishing machine that creates a figure eight polishing pattern mechanically. 
     An additional object is to be able to polish a large number of fiber optic connectors, or similar items, simultaneously. 
     Yet another object is to produce optimum quality polishing of fiber optic connectors or similar items. 
     Still another object is to incorporate a figure eight polishing pattern into a compact polishing machine. 
     A further object is to be able to produce higher quality polished fiber optic connectors, or similar products, more rapidly, in greater quantities, and with lower unit costs than is now obtainable with the prior known polishing techniques. 
     A still further object is to provide a polishing machine that is easy to operate, requires minimum maintenance, and has a very long life expectancy. 
     These and other objects will become apparent upon reference to the following description and claims and to the accompanying drawings. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic top plan view of the subject polishing machine with the casing of the machine opened to show components inside of the casing. 
     FIG. 2 is an enlarged schematic front elevation of the machine shown in FIG. 1 but with the front wall of the casing removed so as to show components inside of the casing. 
     FIG. 3A is a view of a figure eight pattern similar to that created by the subject machine and method. 
     FIG. 3B is a schematic diagram showing the multiplicity of figure eight patterns similar to those created during operation of the subject machine and method. 
     FIG. 4 are timing diagrams of the two stages of the subject polishing machine and method. 
     FIG. 5 is a view similar to FIG. 1 but showing angular relationships among the parts of the drive mechanism of the subject machine. 
    
    
     DETAILED DESCRIPTION 
     A polishing apparatus or machine constructed in accordance with the principles of the present invention is generally indicated by the reference numeral  50  in FIGS. 1 and 2. The polishing machine includes a generally rectangular casing or housing  28  having a flat top wall  52 , a flat bottom wall  54 , a front wall  56 , a back or rear wall  58 , and left and right side walls  60  and  62  respectively. With particular reference to FIG. 2, a pair of elongated, transversely spaced mounting blocks  24  are secured to the bottom wall of the casing and extend generally from adjacent to the front wall to adjacent to the back wall in substantially parallel relationship to the side walls. 
     An x-2 stage  23  includes a pair of elongated, x-2 stage tracks  70  secured to the mounting blocks  24  and extending substantially the full length thereof. Accordingly, these stage tracks define an x-2 axis or path generally parallel to the side walls  60  and  62 . The x-2 stage also includes inverted U-shaped x-2 stage bodies  72  individually slidably mounted on the stage tracks for movement along the x-2 axis. The x-2 stage also includes a substantially flat x-2 stage plate  11  bridging and securing to the stage bodies and in a horizontal position when the bottom wall of the casing is horizontal. The x-2 stage plate is rectangular and flat and occupies a large area within the casing although being of smaller outside dimensions than the casing, as best seen in FIG.  1 . Accordingly, the x-2 stage plate and the stage bodies have freedom to move forwardly and rearwardly within the casing on the stage tracks. The length of the stroke of movement of the stage plate is relatively minimal and in the preferred embodiment is approximately from ¾ inch to 1 inch of travel. Moreover, the x-2 stage plate is disposed slightly to the left of the casing, as seen in FIG. 1, thereby leaving space between the stage plate and the right side wall  62 . 
     The subject polishing machine  50  (FIGS. 1 and 2) also includes a y-stage  10  having a single elongated y-stage track  78  that is mounted on and secured to the x-2 stage plate  11  in generally the front left corner of the x-2 plate, as best shown in FIG.  1 . The y-stage track is in right angular relation to the x-2 axis and thus defines a y-axis or path perpendicular to the x-2 axis and parallel to the front and rear walls  56  and  58  of the casing  28 . An inverted, U-shaped y-stage body  80  is slidably mounted on the y-stage track, and a y-stage plate  82  is secured to the y-stage body in generally parallel relation to the x-2 stage plate  11 . The y-stage plate is also flat and rectangular but is much smaller in outside dimensions than the x-2 stage plate, as best seen in FIG.  1 . Thus, the y-stage plate and the y-stage body are reciprocally moveable on the y-stage track along the y-axis and have a predetermined stroke to which reference will subsequently be made. 
     Still further, the polishing machine  50  (FIGS. 1 and 2) includes an x-1 stage  9  having an x-1 stage track  90  secured to the y-stage plate  82  in right angular relation to the y-stage track and thus defining an x-1 axis perpendicular to the y-axis and parallel to the side walls  60  and  62  and x-2 axis. The x-1 stage also includes an inverted U-shaped x-1 stage body  92  slidably mounted on the x-1 stage track  90  for reciprocal movement along the x-1 axis. An x-1 stage plate or interface plate  22  is secured to the x-1 stage body in generally parallel relation to the y-stage plate  82  and the x-2 stage plate  11 , as best seen in FIG.  2 . Moreover, as best seen in FIG. 1, the x-1 stage plate  22  is of a shape similar to the y-stage plate  82  and is generally perpendicular to it. Thus, the x-1 stage plate is mounted for movement with the x-1 stage body along the x-1 axis defined by the x-1 stage track. 
     A generally square base plate  21  (FIGS. 1 and 2) is disposed above the top wall  52  of the casing  28  in parallel relation thereto and is secured to the x-1 stage plate  22  through an opening  100  in the top wall of the casing. The base plate has a flat, top polishing surface  104  to which a polishing media, such as a film or a slurry, is applied for effecting the polishing action. This polishing media and its application are well known in the art and are thus not described in any detail herein. 
     With particular reference to FIG. 1, a drive mechanism  108  includes a main drive pulley  1  located generally in the upper right hand corner of the x-2 stage plate  11  and has a drive shaft  110  rotatably mounted on the x-2 stage plate  11 . An x-1 drive pulley  3  has its drive shaft  112  also rotatably mounted on x-2 stage plate in laterally offset relationship to the main drive pulley. A y-drive pulley  2  has its drive shaft  114  also rotatably mounted on the x-2 stage plate in forwardly spaced relation to the main drive pulley. Furthermore, an idler pulley  7  is interposed the x-1 and y-drive pulleys, a timing belt  4  connects all of the pulleys, and a main drive motor  8  is connected to the main drive shaft  110  for imparting rotation to the pulleys. It is thus to be observed that all of these pulleys are in a common plane parallel to the x-2 stage plate  11 , that the diameters of the main and x-1 drive pulleys  1  and  3  are the same, and that the diameter of the y-drive pulley  2  is less than the diameter of the x-1 drive pulley  3 . Accordingly, the speed of rotation of the y-pulley is greater than the speed of rotation of the x-1 pulley. An x-1 connecting rod  5  is connected by pin  120  to the x-1 drive pulley and by pin  122  to the rearward end of the x-1 stage plate  22 . A y-connecting rod  6  is connected by a pin  126  to the y-drive pulley  2  and by a pin  128  to the right end of the y-stage plate  82 . 
     With reference to FIGS. 4 and 5, certain relationships of the drive mechanism  108  are now described. With the drive pulleys  1 ,  2  and  3  and the connecting rods  5  and  6  in the positions shown in FIG. 5, the connecting rod  5  is aligned with the x-1 axis and extends diametrically of the x-1 drive pulley  3 . At this same time in the cycle of movement of the drive mechanism, the connecting pin  126  for the y-connecting rod  6  is at its rearwardmost position. In adjusting the positions of the pulleys during installation thereof, the described relationship of the x-1 and y-connecting rods  5  and  6  to their respective pulleys  3  and  2  is accomplished by insuring the ninety degree relationships shown in FIG.  5 . That is, in this setting position for the timing of the drive mechanism, there is a ninety degree angle between the x-reference line  136  and the main reference line  138  and a ninety degree angle between the main reference line  138  and the y-reference line  140 . Such adjustments insures proper timed movements of the x-1 and y-stage plates  22  and  82 , respectively. Alignment of the x-1 timing dots  142  and  144  respectively on the x-2 stage plate  11  and the x-1 drive pulley  3  and alignment of the y-timing dots  146  and  148  respectively on the x-2 stage plate  11  and the y-drive pulley  2  insure proper setting of the correct timing relationships. 
     In the preferred embodiment (FIGS. 1,  2 , and  5 ) of the subject machine  50 , the main and x-1 drive pulleys  1  and  3  each has a radius of 1.50 inches and the y-drive pulley  2  has a radius of 0.75 inches, whereby the diameter of the x-1 drive pulley is two times the diameter of the y-drive pulley. Although the exact dimensions of the pulleys are not critical in the present invention, the 2:1 ratio of the diameters of the x-1 drive pulley to the y-drive pulley is critical to achieving a constant and uniform figure eight pattern. Because of this 2:1 ratio, it will be understood that the stroke of the x-1 stage is two times the stroke of the y-stage. Furthermore, in the preferred embodiment, the distance between the y-reference line  140  and the center of the main drive shaft  110  is 2.4375 inches whereas the distance between the main reference line  138  and the center of the x-1 drive shaft  112  is 2.8438 inches. The important point to note here is that although these specific dimensions are not critical and may be varied, the dimensional relationships are important and do control the figure-eight pattern traced by the polishing surface  104 . 
     With reference to FIGS. 1 and 2, a bracket  150  is secured to and depends from the x-2 stage plate  11  adjacent to the front wall  56  of the casing  28 . A lead screw  18  is rotatably received in the bracket and extends fore and aft of the casing in parallel relationship between the mounting blocks  24 . A lead nut  19  is secured to the casing adjacent to the rear wall  58  and threadably receives the lead screw. An x-2 drive motor  20  is connected to the lead screw so that upon rotation of the lead screw, the x-2 stage plate  11  is moved forwardly and rearwardly within the casing along the x-2 axis depending on the direction of rotation of the screw. Forward and rearward limits switches  25  are mounted on one of the mounting blocks  24  for engagement by a striker  152  that depends from one of the x-2 stage bodies  72 , as illustrated in FIG.  2 . Thus, as the lead screw  18  rotates clockwise in FIG. 2, the x-2 stage plate moves forwardly until the striker  152  engages the forward limit switch. Closure of the forward limit switch reverses the motor which causes the lead screw to rotate in a counterclockwise direction and move the x-2 stage plate rearwardly. Upon the striker engaging the rearward limit switch, the motor again reverses and the cycle repeats. Engagement of the striker with the limit switches thus causes reciprocal movement of the x-2 stage plate, and thus both of the y- and x-2 stages, along the x-2 axis. 
     In addition, the subject polishing machine  50  (FIGS. 1 and 2) includes a power supply  13 , start and stop switches  17  and  15 , and a timer  16 . The power supply supplies power to the drive motors  8  and  20  and to the timer. The start and stop switches energize and de-energize the two motors. The timer is in the circuit with the two drive motors so as to control the amount of polishing time. 
     Although not part of the subject polishing machine  50 , a polishing fixture  26  is illustrated in FIG.  2 . This fixture is mounted on the top wall  52  of the casing  28  and straddles the base plate  21 , being positioned by locating pins  27 . The polishing fixture is capable of mounting a rectangular array of fiber optic connectors  200 , only one of which is shown in FIG.  2 . Each of these connectors is vertically disposed so as to have its end  202  to-be-polished in engagement with the polishing surface  104  of the base plate  21 . Thus, when the polishing fixture is loaded with fiber optic connectors, there are rows and columns of connectors extending parallel to the x and y axis described above with the surfaces to-be-polished  202  all in engagement with the base plate  21 . In a preferred embodiment of the polishing fixture, the connectors may be located on one inch centers thereby providing for the holding of large arrays of connectors in polishing positions. Preferred embodiments of the polishing fixture respectively mount  12 ,  24 ,  36 , and  48  connectors in such a rectangular array, it being understood that even more connectors may be accommodated using the figure eight polishing pattern of the present invention. 
     OPERATION 
     With reference to FIG. 3, operation of the subject polishing machine  50  moves the base plate  21  in a figure eight pattern close to but not exactly the same as shown in FIG.  3 B. As is known and in general, the parts of a figure eight may occur in slightly varying shapes and still be recognizable as a figure eight, and such is the case with the figure eight pattern created by the subject machine. In operation, the main drive motor  8  is energized to rotate the x-1 drive pulley  3  and the y-drive pulley  2  each of which, through their respective connecting rods  5  and  6 , reciprocates the x-1 stage plate  22  and the y-stage plate  82 . The cycles of movement of the x-1 and y-stages are illustrated in FIG. 4 which shows timing diagrams for the two stages on a common time line. As previously stated, the stroke of the x-1 stage plate is twice the stroke of the y-stage plate. Although each stage plate moves reciprocally along its individual axis, the resultant movement of the base plate is in a figure eight pattern. Furthermore, with energization of the x-2 drive motor  20 , the x-2 stage plate  11  and thus both of the y-stage  10  and the x-1 stage  9  are moved forwardly and rearwardly along the x-2 axis so that the figure eight pattern is moved forwardly and rearwardly, similar to that illustrated in FIG.  3 B. That is, although each individual figure eight pattern differs slightly from those shown in FIG. 3A and 3B, the overall pattern of moving figure eights, whereby a succession of multiple figure eights (eight as shown in FIG. 3B) is created, is generally as shown in FIG.  3 B. 
     From the foregoing, it will be understood that the subject polishing machine  50  allows use of all of the area of the polishing surface  104  to polish the connectors  200 , or similarly configured industrial components. By using a figure eight polishing pattern that is uniform and constant, a full rectangular array of connectors  200  can be provided thereby allowing far more connectors to be polished simultaneously than previous polishing machines. In previous machines, such a large number of connectors to-be-polished can not be accommodated since the connectors can be positioned only at the outer most edges or periphery of the rotating polishing surface that traces a circular pattern. 
     The subject machine  50  produces not only a uniform and constant figure eight polishing pattern (FIG.  3 A), but it also moves the pattern back and forth to produce multiple figure eight patterns (FIG. 3B) and thereby prevent wear and burnout of the lapping film on the polishing surface  104  and allow for maximum usage of various polishing media, whether films or slurries. The subject polishing pattern is created by the described and illustrated mechanical motion control system employing the components shown and described. 
     Although preferred embodiments of the present invention have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the present invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.