Abrading Apparatus for Spherically Shaping Workpieces

The present invention relates to a device for grinding and polishing a tip of stick-like member spherically.

In the prior art, when grinding and polishing the tip of a stick-like member spherically, the stick-like member is held at a rotational opening, in contact with the surface of the rotating wheel, and then ground and polished spherically by receiving a rocking movement at an angle corresponding to the complete spherical surface R, the supporting point being the axis of the stick-like member and the contact surface of the wheel. However this kind of device needs another device to maintain the accuracy of the wheel surface and the device itself is very complicated. Also, as this device needs the rotation of the stick-like member, this device is unsuitable for grinding long and fine materials.

The present invention is proposed to solve the above defects, and by equipping a spherical axis bearing on the jig board, the rotation of the stick-like member becomes unnecessary, and also by combining the use of above jig board and the rocking mechanism of the device itself, the need of the mechanism to maintain the surface accuracy of the wheel is solved, thereby offering a device which can grind and polish the spherical surface of the tip of a stick-like member with a simple mechanism.

The apparatus according to the present invention grinds and polishes the tip of the stick-like member with a simple mechanism where the jig board attached orthogonally to the surface of the spherical wheel, is mounted on the jig board fixing axis through the spherical axis bearing which freely adjusts the jig board relative to the spherical surface of the wheel.

FIG. 1 shows a sectional structure of an embodiment according to the present invention.

FIG. 2 shows the positional relation between the wheel and the jig board.

FIG. 3 shows the relation between the wheel surface, the stick-like material, and the jig board.

Thorough explanation referring to the drawings showing an embodiment of carrying out the invention follows:

Referring to FIG. 1, reference numeral 1 designates a jig board fixing rod, and a flange 1a which bears a jig board 8 is formed on the upper part of the jig board fixing rod 1. This jig board fixing rod 1 is supported by a machine-body-base or frame 16, and extends through a rotation shaft or cylindrical inner shaft 2, a wheel shaft or hollow cylindrical outer shaft 4, and a shaft bearing 7. The rotation shaft 2 has an eccentricity through-hole 2a in which the jig board fixing rod 1 extending downwardly from the flange 1a is inserted axially slideably from upper position. The wheel shaft 4 has a hollow cylindrical structure which supports rotatably the rotation shaft 2; the shaft bearing 7 is also cylindrical and supports the wheel shaft 4 rotatably. The upper ends of the shaft bearing 7, wheel shaft 4 and rotation shaft 2, are formed in T-shape in section. The T-shaped part of shaft bearing 7 is supported by fixed to an attach hole of the machine body base 16, the T-shape part on the upper part of the wheel shaft 4 is held rotatably on the T-shape upper end of the shaft bearing 7 with its self-weight, and the T-shape part of rotation shaft 2 is held rotatably on the upper part of T-shape part of the wheel shaft 4 with its self-weight. As the rotation shaft 2 and the wheel shaft 4 are rotatively driven as stated below, the device does not increase the friction at the contacting part of these two shafts.

Meanwhile, the lower end of the wheel shaft 4 is extended below the lower end of the shaft bearing 7, and the lower end of the rotation shaft 2 is extended below the lower end of the wheel shaft 4, and the lower end of the jig board fixing rod 1 is extended below the lower end of the rotation shaft 2. Furthermore, a cog wheel 5 which gears into an unshown cog wheel is attached to the extended lower outer periphery of the the wheel shaft 4 and a cog wheel 3 which gears into another unshown drive cog wheel is fixed to the extended lower outer periphery of the rotation shaft 2. A device or support means 17 holds the extended lower end of the jig board fixing rod 1 for stopping or restraining the rotation of the jig bord fixing rod 1. An abrading wheel 6 is attached and fixed to the upper T-shape portion of the wheel shaft 4 with means of screws and such, and the abrading wheel 6 has an escape hole 6a which receives therethrough the said jig board fixing rod 1 including a flange 1a disposed on the upper end thereof, and the upper portion of the abrading wheel 6 forms an annular upper spherical abrading surface R which grinds and polishes a spherical surface of a stick-like member or workpiece 11. Referring to FIG. 3, the width W of the annular spherical abrading surface R is determined in accordance with the eccentricity quantity or gyratory radius of the eccentricity hole 2a formed in the rotation shaft 2 so that the stick-like member is rocked, ground and polished along the whole range of the width W. 8 shows the jig board which has means 12 along a peripheral portion thereof for holding the stick-like members 11, and the jig board 8 is fixed to the flange 1a of the jib board fixing rod 1 through a spherical or universal bearing 9. Therefore, this jig board 8 is possible to move freely or universally along a spherical surface 9a of the spherical bearing9. The plurality of the stick-like members 11 are attached onto this jig board 8 so that the surface thereof to be ground is orthogonal to the tangent direction of the upper spherical abrading surface of the wheel 6. Moreover, number 10 in FIG. 1 and FIG. 3 designates a locking fastening which fixes the spherical bearing 9 to the jig board fixing rod 1, and also acts as a weight applied to the stick-like members. Number 12 designates a metal fitting which fixes and supports the stick-like members 11 to the jig board 8.

Explanation referring to FIG. 2 which shows the operation position or gyratory movement of the stick-like member 11 attached to the jig board 8 along the upper spherical abrading surface of the wheel 6 follows: First, in the state shown in FIG. 1, the wheel 6 rotates around a main axis of the wheel shaft 4 by unshown drive source in the direction of arrow 15 through the wheel shaft 4, and the rotation shaft 2 also rotates around the main axis by an unshown drive source in the direction of arrow 14 opposite to the wheel shaft 4. The jig board fixing rod 1 inserted in the eccentricity hole 2a undergoes a gyratory movement around the main axis along the locus of rotation-radius r in response to the movement of the the eccentricity hole 2a formed in this rotation shaft 2. At this point, the jig board fixing rod 1 is held by the rotation-stop-device or the support means 17 so that the jig board fixing rod 1 does not rotate around an axis thereof during the gyratory movement thereof. Therefore, each of the stick-like members 11a-11h set on the jig board 8 undergoes a corresponding gyratory movement along each of rocking locuses 13a-13h of radius r, same as the locus of rotation-radius r of the jig board fixing rod 1 because the jig board 8 is centrally connected to the top end of the jig board fixing rod 1 and undergoes the gyratory movement together therewith. Since each of the stick-like members 11a-11h is disposed in frictional contact with the upper spherical abrading surface R by the self-weight of the jig board fixing rod 1 and the jig board 8, each of the stick-like members 11a-11h can be ground and polished. At this point, each of the stick-like members 11a-11h rocks and undergoes the gyratory movement along each of the loci 13a-13h respectively on the spherical abrading surface R. Further, the jig board 8 undergoes an up-and-downwards rocking movement or adjusting movement around the spherical surface of spherical bearing 9 with respect to the spherical abrading surface R during the gyratory movement of the jig board 8. Eventually, the surface of the tip of stick-like member 11 is spherically processed by a fictional contact with the spherical abrading surface R. Though the method of forming the spherical abrading surface R in concavo-shape and forming the tip of the member in convexo-shape is explained in this embodiment, this apparatus can be operated in other ways, where the spherical abrading surface is formed convexo and the tip concavo. Also, the rotation-stop device is mounted to prevent the rotation of the jig board fixing rod, but there will be no influence on the grinding and polishing of the spherical surface even when the rotation-stop device is removed and the jig board fixing rod can rotate freely.

As stated as above, according to the present invention, the tip of long and fine stick-like member can be processed spherically, with a simple and improved mechanism having the spherical abrading surface of the wheel and the jig board on which the stick-like member is set without any addition of other parts, and this device can be used especially for grinding and polishing the tip of optical fiber connectors for use in optical communications, and so the industrial value and effect of this device is great.