MXPA00008275A - Polishing apparatus - Google Patents

Abstract

A polishing apparatus (1) includes a lapping tape (3) for polishing a surface of a magnetic disc (2), a tape supply unit (4) for supplying the lapping tape, a varnisher roller (5) for pressing the lapping tape (3) onto the surface ofthe magnetic disc (2), and a pressing unit (6) for pressing the lapping tape to the surface of the magnetic disc by way of the varnisher roller (5). The pressing unit (6) is constituted by a swing lever (51) having the varnisher roller (5) at one end portion, and a balance adjusting unit (52). The balance adjusting unit (52) sets the pressing force to zero by establishing the balance of the swing lever (51), and then breaks the balance so as to press the lapping tape to the surface of the magnetic disc by way of the varnisher roller with a desired pressing force.

Description

"POLISHING APPARATUS" BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION This invention relates to a polishing apparatus for polishing surfaces of material to be polished with abrasive, and more particularly with a polishing apparatus which is appropriately used in a so-called coating system which shaves the protuberances on the surfaces of a magnetic disc without damaging the surfaces or similar. 2. DESCRIPTION OF THE RELATED TECHNIQUE: As the polishing apparatus used for the coating system, a polishing apparatus that includes an overlapping belt to polish a surface of a magnetic disk, a belt supply unit for supplying the overlapping belt, a rubber roller for placing the overlap tape supplied by the tape supply unit in contact with the surface of the magnetic disk, and a pressure unit for pressing the overlapping tape to the surface of the magnetic disk with a given pressure through a rubber roller is already known. e * ti? t In the polishing apparatus, a pneumatic cylinder (or air cylinder) is generally used as the pressure unit. Meanwhile, since the polishing apparatus uses the pneumatic cylinder, the pressure unit, the apparatus has the following inconveniences. (1) Since pneumatic pressure has a tendency to fluctuate, it is difficult to retain the pressing force at a desired level. (2) It is difficult to adjust the pressure force of the pneumatic cylinder. Particularly, it is difficult to add the tiny pressure force in the order of several grams to the overlapping belt with the pneumatic cylinder. (3) The pneumatic cylinder is not suitable for placing the overlapping tape in gradual and smooth contact with the magnetic disk, and for gradually and smoothly moving the overlapping tape away from the magnetic disk.

COMPENDIUM OF THE INVENTION It is therefore an object of the present invention to provide a polishing apparatus capable of producing the desired pressing force. According to the present invention, a polishing apparatus comprises: an abrasive material supply unit (4, 7) for supplying an abrasive material; a first guide member of abrasive material (5) for pressing the abrasive material supplied from the abrasive material supply unit, to a first surface of the material to be polished; and a pressure unit (6) for pressing the abrasive material towards the first surface of the material to be polished, with a predetermined pressure force through the guide member of the abrasive material. The pressure unit comprises, an oscillating lever (51) which is provided with the guide member of the abrasive material (5), and an equilibrium adjustment unit (52) which presses the abrasive material towards the material to be polished. through the guide member of the abrasive material with a desired load determined by adjusting a load applied to the oscillating lever.

BRIEF DESCRIPTION OF THE DRAWING A single figure is a perspective view showing a polishing apparatus in accordance with one embodiment of the present invention.

DESCRIPTION OF THE PREFERRED MODALITIES A single figure schematically shows in perspective a polishing apparatus 1 according to an embodiment of the present invention. The polishing apparatus 1 includes an abrasive material 3 that polishes a material 2 to be polished, an abrasive material supply unit 4 that supplies the abrasive material 3, a first abrasive material guide member 5 that places the supplied abrasive material 3 by the supply unit of abrasive material 4 in contact with a first surface of material 2 to be polished, and a pressure unit 6 which presses abrasive material 3 towards the first surface of material 2 to be polished, at a pressure determined through the first guide member of abrasive material 5. The material 2 to be polished is a magnetic disk and it is provided with magnetic layers on the upper and lower surfaces of a circular plate made of plastic. A metal hub for strangulation is provided in the central portion of the circular plastic plate. (Some magnetic discs do not have a metal bucket). The magnetic disk as the material 2 to be polished (the material to be polished is simply called "magnetic disk 2" below) is supplied by a rotary-type disk supply device 7. The disk supply device 7 includes a rotating arm 8 in the form of a "V" which is provided with the vacuum-type disc suction heads 8a at both ends thereof In the disc supply device 7, after sucking a magnetic disk 2 with one of the disk suction heads 8a, the "V" shaped rotary arm 8 is rotated about a vertical arrow 9 as the center of rotation in order to transport the disk 2 magnetic position to a position just above a first spindle 10 or a second spindle 11. Then, the vacuum suction is released to place the magnetic disk 2 either in the first spindle 10 or in the second spindle 11. The position of the first spindle 10 shown in the figure is a transfer position for receiving a disk 1. The position of the second spindle 11 shown in the figure is a polishing position for a disk 2. In the polishing position, a throttle member 12 is lowered until the magnetic disk 2 is throttled towards the spindle. Then, the strangulated magnetic disk 2 is rotated by the spindle to polish the magnetic disk 2. The first and second spindles 10 and 11 are respectively placed in the first and second end portions of a sliding table 13. The sliding table 13 extends from the first end portion to the second end portion along a sliding direction (shown by an arrow AB) along which the sliding table 13 is slidable. The sliding table 13 is driven by a rail 14 and a pneumatic cylinder 15 (or air cylinder). The first and second spindles 10, 11 are movable between the transfer position and the polishing position. _ An overlap tape is used as the abrasive material 3. (Next, the abrasive material is simply called "overlap tape 3"). The lap tape 3 has a base film coated with abrasive particles of alumina, chromium oxide, silicon carbide or the like, having the average particle size of 0.1 ~ 10 microns. The abrasive material supply unit 4 includes a ribbon supply reel 22 which is provided with a torque motor 21, a ribbon winding reel 24 (or intake) that is provided with a torque motor 23, first to seventh tape guide rollers 25 ~ 31 positioned in such a manner between the tape supply reel 22 and the tape winding reel 24 as to constitute a tape path system of the overlap tape 3, a pair of a belt drive roller 32 and a holding roller 33 positioned between the seventh belt guide roller 31 and the belt winding reel 24, a motor 34 for rotating the drive roller 32, and a pneumatic cylinder 36 ( or air cylinder) which rotates the clamping roller 33 about an arrow 35 in the direction to place the clamping roller 33 in contact with the belt drive roller 32 or in the direction to move the clamping roller. 33 is moved away from the belt drive roller 32. The overlap belt 3 is clamped between the belt drive roller 32 and the clamping roller 33 which rotate about the arrow 35 via the pneumatic cylinder 36, towards the belt drive roller 32. Then, the belt drive roller 32 is rotated by the motor 34 in order to carry out the supply of the overlap belt 3. Between the second belt guide roller 26 and the third belt guide roller 27, a vacuum chamber 41 is provided to maintain the tension of the tape of the overlap tape 3 at a constant value. The overlapping tape 3 is inserted in the vacuum chamber 41, between the second and third tape guide rollers 26 and 27. The overlapping tape 3 introduced into the interior of the vacuum chamber 41 is sucked by a negative pressure generated by a vacuum pump (not shown in the drawing) and introduced through a vacuum suction hole 42 formed in the bottom of the vacuum chamber 41, so that the tension of the tape of the overlap tape 3 is It can keep at a roughly constant value. Above the magnetic disk 2, in the polishing position, the first guide member 5 of abrasive material is provided to place the overlapping tape 3 in contact with the upper surface of the magnetic disk 2. As the first guide member of abrasive material 5, for example, a hard urethane rubber rubber roller having a hardness of about 65 is used. (Next, the first guide member of abrasive material is called "the first roller. 5"varnish). The first varnish roller 5 extends in the radial direction of the magnetic disc 2, and is positioned to press the overlapping tape 3 towards the upper surface of the magnetic disc 2 with a desired load (pressure) by means of the pressure unit 6. The pressure unit 6 includes an oscillatory lever 51 (or bar) that is provided with the first varnish roller 5, and an equilibrium adjustment unit 52 that presses the overlap tape 3 on the magnetic disk 2 to a desired load through of the first varnish roller 5 by adjusting the load applied to the oscillating arm 51. The first oscillatory lever 51 is mounted on a first end portion of a rotating shaft 54 that is rotatably supported by a bearing 53. The balance adjustment unit 52 includes first , second and third balance weights 55, 56 and 57.

The first equilibrium weight 55 establishes the balance (balance) of the oscillating arm 51, applying the load to the oscillating lever 51. The second balance weight 56 applies a load to an oscillatory lever 51 in the direction for moving the first varnish roller 5 and the overlap tape 3 remote from the first surface (upper surface) of the magnetic disk 2. The third balance weight 57 applies a load to the oscillating lever 51 in the direction for positioning the first varnish roller 5 and the lap tape 3 in contact with the first surface (upper surface) of the magnetic disc 2. The first balance weight 55 is placed in a first portion 51a receiving the balance weight provided in a first lever portion of the oscillatory lever 51 opposite the first varnish roller 5 in order to establish the balance of the oscillating arm 51. The first roller varnish 5 is placed on a second lever end portion, the first balance weight 55 is on the first lever end portion and the first arrow end portion of arrow 54 (serving as a support center) is placed between the first and second lever end portions. A second portion 58a receiving the balance weight for receiving the second balance weight 56 is provided on a first end portion of the balance weight receiving lever 58 (or bar), which is mounted on a second end portion of the balance. Arrow arrow 54 rotational. The lever 58 receiving the balance weight extends approximately parallel to the oscillating lever 51. The second balance weight 56, when placed in the weight-receiving portion 58a, acts to rotate the arrow 54 and to move the first roller varnish 5 and overlap tape 3 away from disk 2 to a standby position. A third balance weight receiving portion 58b is provided in a second lever end portion of the balance weight receiving lever 58. The second end of the arrow of the arrow 54 which serves as the fulcrum is placed between the second and third balance weight receiving portions 58a and 58b. The third balance weight 57 when placed on the receiving portion 58b, acts to rotate the oscillating lever 51 through the arrow 54, in the direction to move the first varnish roller 5 and the overlap tape 3 is brought into contact with the first surface (upper surface) of the magnetic disk 2. The second balance weight 56 and the third balance weight 57 are connected by a rope 59 running through a pulley 60. The pulley 60 is rotationally driven by a motor 61. When the pulley 60 is rotated in one direction ( dextrorotatory direction), the second balance weight 56 is placed in the second balance weight receiving portion 58a and the third balance weight 57 rises from the third balance weight receiving portion 58b. When the pulley 60 is rotated in the other direction (left-handed direction), the third balance weight 57 is placed in the third balance weight receiving portion 58b and the second balance weight 56 rises from the second balance receiving portion 58a. balance weight. Each of the first, second and third balance weights 55, 56 and 57 is adjustable so that the weight can be adjusted within the order of 1 gram. The weight of the first balance weight 55 is graded to a value for canceling the weight of the first varnish roller 5, and to establish an equilibrium of the oscillating lever 51. The weight of the second balance weight 56 is graduated to a required weight value to rotate the oscillatory lever 51 balanced by the first balance weight 55, in the direction to move the overlapping tape 3 away from the first surface (upper surface) of the magnetic disk 2 through a predetermined distance to the state position Standby. The third balance weight 57 is graded to a weight to produce a desired load with which the overlap tape 3 is pressed towards the first surface (upper surface of the magnetic disc 2. If, for example, the desired load is 10 grams, then the weight of the third balancing weight 57 is adjusted equal to grams In a lower position by confronting the first coating roller 5 through the disc 2, a second guide member 61 of abrasive material is provided to place an overlap tape 3A to polish the lower surface of the magnetic disk 2 in contact with the lower surface of the magnetic disk 2. As the second material guide member 61 abrasive, a rubber roller is used as in the case of the first varnish roller 5. (Next, the second abrasive material guide member is called the "second varnish roller.") The second varnish roller 61 is fixedly secured in a roller support member 62. The second paint roller 61 is placed below the magnetic disk 2 in order to form a free space of approximately 0.1 ~ 1 millimeter between the second varnish roller 61 and the lower surface of the magnetic disc 2, to prevent the overlapping tape from coming into contact with the lower surface of the magnetic disc 2 in the spindle 10 or 11, when it is placed in the polishing position by the sliding table 13. Roller support member 62 is provided with a load cell (not shown in the drawing) which senses the load (pressure force) of the pressure unit 6 applied through the second coating roller 61. The supply of the lower lateral overlapping tape 3A is achieved by a supply unit 4A of lower lateral abrasive material. Since the lower side abrasive material supply unit 4A is essentially identical in construction to the upper side abrasive material supply unit 4, the same reference numerals are provided to the same constituent parts and their explanation is omitted.

Subsequently, the manner of operation of the polishing device 1 of the present invention is explained. The first balance weight 55 is placed on the first balance weight receiving portion 51a of the oscillatory lever 51, in order to establish the balance of the oscillating arm 51. Then, the pulley 60 is rotated in the clockwise direction to place the second equilibrium weight 56 in the second equilibrium receiving portion 58a. When the second balancing weight 56 is placed, the balance of the oscillating arm 51 is broken and the first lapping roller 5 and the overlapping tape 3 are retracted to a waiting position where they do not obstruct the movement of the magnetic disk 2 towards the polishing position. The magnetic disk 2 supplied to the disk supply device 7 is sucked by a disk suction head 8a of the disk supply device 7, and then placed in the spindle waiting in the transfer position. In the magnetic disk 2, the spindle is transported from the transfer position to the polishing position by the sliding table 13. When the second balancing weight 56 rises from the second equilibrium weight receiving portion 58a by rotating the pulley 60 in the clockwise direction, the oscillatory lever 51 again achieves balance. By rotating the pulley 60 further in the left-handed direction, the third balance weight 57 is placed in the third balance weight receiving portion 58b so that the first coating roller 5 and the overlapping tape 3 are pressed to the first surface ( upper surface) of the magnetic disk 2 with the load of the third balance weight 57, that is, with the 10 gram load, and the lower surface of the magnetic disk 2 is also pressed to the lower side overlap tape 3A. Subsequently, when the magnetic disk 2 is transported to the polishing position and adjusted in the choked condition, the spindle is rotated at a predetermined rotation speed (300 ~ 1200 revolutions per minute). Correspondingly, the upper side overlap tape 3 and the lower side overlap tape 3A are pressed towards the upper and lower surface of the magnetic disk 2 with approximately the same loads (approximately 10 grams) and polish these upper and lower surfaces. Upon completion of the polishing, the pulley 60 is rotated in the clockwise direction to lift the third balance weight 57 from the third balance weight receiving portion 58b to the oscillatory arm 51 again achieves the balanced condition. When the pulley 60 is further rotated, the second balance weight 56 is placed in the second balance weight receiving portion 58a. Correspondingly, the overlapping tape 3 moves towards the waiting position which is separated from the first surface (upper surface) of the magnetic disk 2. Then, after polishing is completed, the polished magnetic disk 2 is returned to the transfer position and then sucked through the disk suction head 8a of the disk supply device 7 to be transported to a person collecting the finished product. that is omitted from the drawing. Even when the weight of the second and third balance weights 56 and 57 are adjusted to 10 grams in the illustrated example, the weights are appropriately determined depending on the kind, thickness or similar means of the magnetic layer of the magnetic disk 2. Furthermore, even when the illustrated example employs an overlap tape as the abrasive material, the abrasive material is not limited to the overlap tape. In addition, the material to be polished is not limited to the magnetic disk. The polishing apparatus according to the present invention has the following effects. (1) The polishing apparatus is capable of polishing the material to be polished with a desired pressure by the use of a simple lever structure. (2) The polishing apparatus can establish the balance of the oscillating lever with the first balance weight, move the abrasive material away from the first surface of the material to be polished by means of the second equilibrium weight, and press the abrasive material towards the first surface of the material to be polished by means of the third equilibrium weight with a given load. (3) The polishing apparatus can easily adjust the load using the first, second and third balance weights that are adjustable. (4) The polishing apparatus can apply any of the loads of the second and third balance weights to the oscillating lever while preventing the other load from being applied to the oscillating lever by a simple pulley structure. (5) The polishing apparatus can polish the first and second surfaces of the material to be polished simultaneously. (6) The polishing apparatus employs the first and second guide members of the abrasive material placed - to hold the material to be polished obtaining in this way the effective polishing of the opposite surfaces. (7) The polishing apparatus can accurately detect the pressing force (load) of the pressure unit by the load cell that is provided in the second guide member of the abrasive material. (8) The polishing apparatus uses the rubber roller as the guiding member of the abrasive material and therefore, the supply and guidance of the abrasive material can be carried out uniformly. (9) The polishing apparatus uses the overlapping tape as the abrasive material and therefore, the continuous supply of the abrasive material can be carried out simply and easily by using reels or similar means. (10) The polishing apparatus can keep the tape tension of the overlap tape to a low value using the negative pressure inside the vacuum chamber.

Claims (14)

CLAIMS:

1. A polishing apparatus comprising: an abrasive material supply unit (4, 7) for supplying an abrasive material; a first guide member of abrasive material (5) that places the abrasive material supplied by the abrasive material supply unit to a first surface of the material to be polished; and a pressure unit (6) which presses the abrasive material towards the first surface of the material to be polished with a predetermined pressure force through the guide member of the abrasive material, the pressure unit comprises, an oscillating lever (51). ) which is provided with the guide member of the abrasive material (5), and an equilibrium adjustment unit (52) which presses the abrasive material towards the material to be polished through the guide member of the abrasive material with a load desired determined by adjusting a load applied to the oscillating lever.

A polishing apparatus according to claim 1, wherein the balancing adjustment unit (52) comprises: a first balancing weight (55) that achieves oscillating lever balance by applying a load to the oscillating lever; a second balance weight (56) that applies a load to the oscillating lever to rotate the oscillating lever from a balanced state in one direction to move the abrasive material away from the first surface of the material to be polished; and a third balance weight (57) which applies a load to the oscillating lever from the balanced state in the direction for pressing the abrasive material towards the first surface of the material to be polished.

3. A polishing apparatus according to claim 2, wherein the weight of each first, second and third balance weights is adjustable.

A polishing apparatus according to claim 3, wherein the polishing apparatus further comprises a pulley (60) for moving the second and third balance weights up and down.

A polishing apparatus according to claim 1, wherein the polishing apparatus further comprises a second guide member of abrasive material (61) that for pressing the abrasive material towards the second surface of the material to be polished opposite to the first surface of the material to be polished.

6. A polishing apparatus according to claim 5, wherein the second guide member of abrasive material (61) is positioned in a position such that the second guide member of the abrasive material confronts the first guide member of abrasive material. (5) through the material to be polished, and that the first guide member (5) the abrasive material is pressed against the second guide member of abrasive material by the pressure unit.

A polishing apparatus according to claim 5, wherein the second guide member of the abrasive material is provided with a load cell for detecting the pressure force of the pressure unit.

A polishing apparatus according to claim 1, wherein the abrasive material guide member (5) is a rubber roller.

9. A polishing apparatus according to claim 1, wherein the abrasive material is an overlapping belt.

A polishing apparatus according to claim 9, wherein the polishing apparatus further comprises a vacuum chamber (41) for retaining the tension of the overlap tape supplied from the abrasive material supply unit at an approximately constant value.

11. A polishing apparatus comprising: a disc support unit (10, 11, 13) for holding a disc in a polishing position; and a pressure mechanism including a first tape guide member (5) for pressing an overlapping tape toward an upper surface of a disc (2), and an oscillating member (51, 54, 58) having an arm of pressure to apply a load to the first tape guide member to press the overlapping tape towards the upper surface of the disc, and an equilibrium arm that adjusts the load applied to the first tape guide member. A polishing apparatus according to claim 11, wherein the oscillating member comprises the balance arm which is a first balance arm having a first weight receiving portion. (51a) to receive a first balance weight (55) to rotate the pressure arm in a release direction, and the third balance arm has a third receiving portion (58b) to receive a third balance weight (57) to rotate the oscillating member in a pressure direction to increase the load. A polishing apparatus according to claim 12, wherein the oscillating member further comprises a second balance arm having a second receiving portion (58a) for receiving a second balance weight to rotate the pressure arm in the direction of liberation. A polishing apparatus according to claim 13, wherein the oscillating member further comprises a rotary arrow (54) defining an oscillating axis of the oscillating member and connecting the second and third balance arms with the first balance arm.