Method for producing a cylindrical buff

Abstract: Method for producing a cylindrical buff (7) with an abrasive surface (7a) is disclosed. A plurality of circular buff material is stacked to form a cylindrical shape. The buff is soaked into a liquid and the liquid is frozen to harden a abrasive surface of the buff. The buff is rotated and the abrasive surface is cut by a cutting tool (15) to smoothen the abrasive surface. Another method for producing a cylindrical buff with an abrasive surface is also disclosed. A plurality of circular buff material is stacked to form a cylindrical shape. The buff is rotated and a liquid is jetted with high speed toward the abrasive surface of said buff to smoothen the abrasive surface.

Description: The invention relates to a method for producing a cylindrical buff with an abrasive surface comprising the steps of stacking a plurality of circular buff material to form a cylindrical shaped buff and rotating said cylindrical buff and cutting the abrasive surface of said cylindrical buff by a cutting tool to smoothen the abrasive surface. This method of the generic kind is described in FR-A-923530 wherein an adhesive is used for connecting a plurality of circular buff material. It is further known to burnish the surface of a work for removing the protruding particles or high spots from the surface by using cylindrical buff which is driven to rotate and urged against the surface of the work. The work is for example, optical disc such as compact disc (CD) or Laser disk (LD.) US-A-5 524 313 and 3 943 666 show a burnishing apparatus for burnishing optical disc such as compact disc. A cylindrical buff is rotated by a drive shaft which is connected to a drive source and an abrasive surface of the buff burnishes a reading surface of a compact disc. Typically, the buff is produced by the steps of blanking the sheet material to form a circular buff material and stacking a plurality of circular buff material to form cylindrical shaped buff. A cut edge or surface of the circular buff material corresponds to the abrasive surface of the buff. A hole penetrates through the drive shaft. An apparatus for burnishing or polishing to remove the damages on a compact disc is disclosed in U.S. -A-5,099,618, US-A-4,179,852. US-A-4,586,296 and JP-A-4-372785. The compact disc has a laser-penetratable layer made of synthetic resin. The layer includes the lower surface on which the digital date is recorded as small pits. The pits are formed as a spiral. Under the layer is formed a laser-reflectable layer which is made of a aluminum metallic film, for example. In turn under the layer is formed a support layer. The layer includes the lower surface on which an information for explaining the contents recorded in the disc, for example title of the music, is to be printed. A reading head includes a beam eject element and beam receive element. The beam eject element ejects the laser beam toward the laser-penetratable layer and the beam receive element receives the beam which is reflected by the laser-reflectable layer. It has been recognized that the reading head sometimes skip or jump data to be reading due to the damages on the disc laser-penetratable layer. It has been also recognized that the damages on the layer sometimes let the disc un-readable in the excessive case. To remove such damages, the buff is used to grind or burnish the reading surface of the laser-penetratable layer. The sheet material is for example, woven cloth with threads, namely warp and weft. Such sheet material made of cloth inclines to transform or deform during the blanking process due to the lack of rigidity, whereby the cut surface of the circular buff material tends to slant. The stacking or assembling process of the circular buff material sometimes results in irregular abrasive surface which is formed because the centers of the circular buff materials are not aligned. The irregular surface may be formed because the circular buff material is transformed due to the pressing force during the assembling process, which press is forged along the length of the buff. The buff having the irregular abrasive surface with projected portions will make scratches, corresponding to the projected portions on the surface of the disc. It is the object of the invention to provide the method of the generic kind by means of which the abrasive surface of the buff made of a material with low rigidity can be easily smoothened. This object is obtained by the method of claim 1. Preferably, the method according to the invention comprises the step of assembling the cylindrical buff and two side plates after the stacking step, said plurality of circular buff material being positioned between said two side plates and pressed in the longitudinal direction. Advantageously, the buff material is made of un-woven cloth or of woven cloth. Firstly, the sheet material made of cloth is cut to blank out a circular buff material. Usual sheet material is woven cloth with threads, namely warp and weft. However, any material generally used for the buff can be used as the sheet material. The sheet material made of cloth inclines to transform or deform during the blanking process due to the lack of rigidity, whereby the cut surface of the circular buff material slants. The surface corresponds to an abrasive surface of the buff. The woven cloth includes threads which inclines to be extracted from the abrasive surface of the buff during the burnishing process. The short pieces of extracted thread will grow to a fluff or lump of the threads and injure the surface of the disc. Thus, after the above burnishing process with the buff made of the woven cloth, the burnished disc will have not the completely glossy surface but "peppered" surface. Even if such surface of the disc may not trouble in reading the date of the disc, the surface is not beautiful. The buff with un-woven cloth can burnish the disc with glossy, completely beautiful surface. Un-woven cloth is made of fiber web which is not made of threads but mechanically, chemically or thermally treated to adhere the fiber. Therefore, the buff made of such un-woven cloth will not encounter the above problem resulted from the fluff or lump of the threads and the burnished disc will have beautiful, glossy reading surface. However, un-woven cloth has rigidity less than the woven cloth, whereby the cut surface of the circular buff material tends to slant more than the case of the woven cloth. According to the invention, the buff material is soaked into a liquid and the liquid is frozen to obtain the rigidity of the surface of the buff material. Such surface can be cut by using usual tool of the lathe and easily be flatten. Even the buff material with low rigidity can be provided with smooth abrasive surface. The invention is further explained referring to the accompanying drawings. FIG. 1A is a cross sectional view showing the liquid permeating the buff, in the case of buff being made of the material which is easy for the liquid to permeate; FIG. 1B is a cross sectional view showing the liquid permeating the buff, in the case of buff being made of the material which is not easy for the liquid to permeate; FIG. 2 is a perspective view showing the step of stacking a plurality of circular buff material to form cylindrical shaped buff according to an embodiment of the invention; FIG. 3 is a perspective view showing the step of assembling the circular buff material, side plates and cylindrical tube integrally. FIG. 4 is a side view showing a step of soaking the cylindrically shaped buff in a liquid and letting the liquid permeating the cylindrical buff according to an embodiment of the invention; FIG. 5 is a perspective view showing the step of cutting the surface of the rotating buff according to an embodiment of the invention; FIG. 6 is a side view showing the step of cutting the surface of the rotating buff according to an embodiment of the invention; FIG. 2 is a perspective view showing the step of stacking a plurality of circular buff material 9 to form a cylindrical shaped buff. After the blanking process, the plurality of circular buff material 9 is stacked to form cylindrical shaped buff as shown in FIG. 2. Reference numerals 11,12 denote side plates made of synthetic resin or metal. Each plates 11,12 has a hole 11a,12a. Two side plates 11,12 are put at right and left sides of a plurality of circular buff material 9, respectively. A tube 13 made of metal, for example aluminum, penetrates the holes 11a,12a of the plates 11,12 and the holes 9b of the circular buff materials 9. FIG. 3 is a perspective view showing the step of assembling the circular buff materials 9 and other members 11, 12 and 13. After the stacking process, two side plates 11,12 are forced toward each other to press the plurality of circular buff material 9 and the both ends of the tube 13 are caulking to fix itself to the side plates 11,12. Thus, the plurality of circular buff material 9, side plates 11,12 and tube 13 are assembled integrally. To smoothen the abrasive surface the embodiment is applicable not only to the circular buff material 9 with inclined abrasive surface 9a resulted from blanking process but also to the circular buff material 9 having an irregular abrasive surface which is formed because the center of the circular buff materials is not aligned, because the circular buff material is transformed due to the pressing force. As described above, the buff 7 having the irregular abrasive surface with projected portions 7b will make the scratches, corresponding to the projected portions 7b, on the surface of the disc. Of course the embodiment is applicable not only to the circular buff material 9 made of very easily transformed material such as un-woven cloth but also to the circular buff material 9 made of usual woven cloth with warp and weft. In addition to, animal skin and any other buff material can be used for this embodiment. FIG. 4 shows an example of soaking process. The buff 7 cylindrically formed as above-mentioned, is soaked in a liquid 14. The liquid 14 is preferably easy to be frozen, for example water. FIG. 4 shows an example in which the buff 7 is in a container 10 filled with the liquid 14. Of course any other way in which the liquid 14 permeates the abrasive surface of the cylindrical buff 9 can be taken. FIGS. 1A and 1B are cross sectional views showing the liquid 14 permeating the buff. In these FIGS., permeating depth of the liquid 14 is denoted as d1, d2, maximum and minimum radius of the buff 7 or buff material 9 are denoted as L and M, respectively. In the case of buff material 9 made of un-woven cloth, the liquid 14 can rather rapidly permeate the buff material 9 and it is easy for the liquid 14 to reach and exceed the minimum radius M in all area of the abrasive surface 9a of the buff material 9. On the other hand, in the case of buff material 9 made of the material which is not easy for the liquid 14 to permeate, for example acrylic resin, it is not easy for the liquid 14 to reach the minimum radius M in all area of the abrasive surface of the buff material 9. The buff 7 with permeated liquid 14 is then refrigerated until the liquid 14 is in solid state. As a result, the portion of buff material 9 in which the liquid 14 permeated has high rigidity. FIG. 5 is a perspective view showing the step of cutting the surface of the rotating buff according to an embodiment of the invention. After the freezing step, a drive shaft 6 is penetrated through a hole 7c of the buff 7 as shown in FIG. 5. The buff 7 is rotated by a drive a source (not shown) and cut the abrasive surface 7a by a tool 15 of a lathe (not shown). Due to the rigidity of the surface 7a the cutting can be easily performed. If the liquid 14 is so deeply permeated the buff material 9 as shown in FIG. 1A, the buff material 9 can be cut without transformation of the abrasive surface 7a even if the buff material 9 is cut till the radius of the buff material 9 being slightly less than the minimum radius M and the abrasive surface 7a can be smoothly or evenly cut. Accordingly, the above-mentioned soaking process, freezing process and cutting process are only one time performed, respectively. On the other hand, if the liquid 14 is so shallowly permeated the buff material 9 as shown in FIG. 1B, the abrasive surface 7a of the buff material 9 will transform because of the force urged by the tool 15 upon the cutting amount exceeds the permeating depth d2 and the abrasive surface 7a can not be evenly cut. Accordingly, the above-mentioned soaking process, freezing process and cutting process are repeatedly performed, respectively until the abrasive surface 7a can be smoothly cut. Thus, by the cutting process, the abrasive surface 7a is cut by the tool 15 until the uneven portion or the projected portions 7b of the buff material 9 are removed owing to the rigidity of the abrasive surface 7a of the buff 7.

Claims: A method for producing a cylindrical buff with an abrasive surface (9a) comprising the steps of stacking a plurality of circular buff material (9) to form a cylindrical shaped buff (7) and rotating said cylindrical buff (7) and cutting the abrasive surface (9a) of said cylindrical buff (7) by a cutting tool (15) to smoothen the abrasive surface (9a), characterized in that between the stacking step and the rotating step said cylindrical buff (7) is soaked into a liquid (14) and said liquid (14) soaked in said cylindrical buff (7) is frozen, whereby due to the soaking and freezing steps the cutting can be easily performed due to the rigidity of the surface of the buff. The method according to claim 1 comprising the step of assembling said cylindrical buff (7) and two side plates (11, 12) after said stacking step, said plurality of circular buff material (9) being positioned between said two side plates (11, 12) and pressed in the longitudinal direction. The method according to claim 1 or 2 wherein said buff material (9) is made of un-woven cloth. The method according to claim 1 or 2 wherein said buff material (9) is made of woven cloth.

Inventors: SATO TAKASHI, SATO, TAKASHI
Applicants: SHOYO SEIKI KK, KABUSHIKI KAISHA SHOYO SEIKI
Application year: 1996
Main classification: B24D18
IPC codes: G11B7, B24D13, B24D3, B24D18, G11B23, B26F3