Abstract:
A manufacturing apparatus and associated method for handling disks disposed in merged pairs in a carrier is provided, wherein spacings between adjacent pairs of the disks are greater than spacings between disks forming each pair. The apparatus includes a first disk contacting surface defining a first cavity that is sized to receivingly engage a selected one of the pairs of disks. A second disk contacting surface defines second and third cavities that are sized to receivingly engage individual disks of the selected pair of disks, wherein disks that are operably engaged in the cavities are spatially separated more adjacent the second disk contacting surface than at the first disk contacting surface.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This is a divisional application of U.S. patent application Ser. No. 10/434,551 that claims priority from U.S. Provisional Patent Application Ser. No. 60/379,199 filed May 9, 2002, which is incorporated by reference herein in its entirety. 
         [0002]    The subject matter of the present application is related to the following applications, each of which has a filing date of May 9, 2003: U.S. Pat. No. 7,083,871 entitled Single-Sided Sputtered Magnetic Recording Disks to Clasara et al.; U.S. patent application Ser. No. 10/435,361 entitled Dual Disk Transport Mechanism Processing Two Disks Tilted Toward Each Other to Grow et al. (Publication No. US-2003-0208899); U.S. patent application Ser. No. 10/434,358 entitled Information-Storage Media With Dissimilar Outer Diameter and/or Inner Diameter Chamfer Designs On Two Sides to Clasara et al. (Publication No. US-2003-0210498); U.S. patent application Ser. No. 10/435,360 entitled Method of Merging Two Disks Concentrically Without Gap Between Disks to Buitron (Publication No. US-2004-0016214); U.S. Pat. No. 7,322,098 entitled Method of Simultaneous Two-Disk Processing of Single-Sided Magnetic Recording Disks to Buitron et al.; U.S. patent application Ser. No. 10/435,161 entitled W-Patterned Tools for Transporting/Handling Pairs of Disks to Buitron et al. (Publication No. US-2003-0209421); U.S. Pat. No. 7,027,502 entitled Method for Servo Pattern Application on Single-Side Processed Disks in a Merged State to Valeri; U.S. Pat. No. 7,083,502 entitled Method for Simultaneous Two-Disk Texturing to Buitron et al.; U.S. patent application Ser. No. 10/435,227 entitled Cassette for Holding Disks of Multiple Form Factors to Buitron et al. (Publication No. US-2004-0069662); U.S. Pat. No. 7,083,376 entitled Automated Merge Nest for Pairs of Magnetic Storage Disks to Crofton et al.; U.S. patent application Ser. No. 10/435,293 entitled Apparatus for Simultaneous Two-Disk Scrubbing and Washing to Crofton et al. (Publication No. US-2004-0070859); U.S. Pat. No. 7,168,153 entitled Method for Manufacturing Single-Sided Hard Memory Disks to Buitron et al.; and U.S. Pat. No. 7,052,739 entitled Method of Lubricating Multiple Magnetic Storage Disks in Close Proximity to Buitron et al. Each of these applications is incorporated by reference in its entirety as if stated herein. All of these applications are commonly owned by the Assignee. 
     
    
     FIELD OF THE INVENTION 
       [0003]    The present embodiments relate to various apparatus and methods for separating or combining a plurality of pairs of single-sided hard memory recording disks. While the apparatus and method can be employed at any needed point within the overall manufacturing process, two particularly suitable uses are at the beginning of the manufacturing process when it is desirable to arrange substrate disks in pairs in cassettes and at the end of the manufacturing process when it is desirable to separate oppositely facing single-sided finished disks positioned in pairs in a single cassette and re-arrange them into two cassettes, with the active surface of each disk in each cassette facing the same direction. 
       BACKGROUND OF THE INVENTION 
       [0004]    Hard disk drives are an efficient and cost effective solution for data storage. Depending upon the requirements of the particular application, a disk drive may include anywhere from one to eight hard disks and data may be stored on one or both surfaces of each disk. While hard disk drives are traditionally thought of as a component of a personal computer or as a network server, usage has expanded to include other storage applications such as set top boxes for recording and time shifting of television programs, personal digital assistants, cameras, music players and other consumer electronic devices, each having differing information storage capacity requirements. 
         [0005]    Typically, hard memory disks are produced with functional magnetic recording capabilities on both sides or surfaces of the disk. In conventional practice, these hard disks are produced by subjecting both sides of a raw material substrate disk, such as glass, aluminum or some other suitable material, to numerous manufacturing processes. Active materials are deposited on both sides of the substrate disk and both sides of the disk are subject to full processing such that both sides of the disk may be referred to as active, or in other words, functional, from a memory storage stand point. The end result is that both sides of the finished disk have the necessary materials and characteristics required to effect magnetic recording and provide data storage. These are generally referred to as double-sided process disks. Assuming both surfaces pass certification testing and have no defects, both sides of the disk may be referred to as active, or functional, for memory storage purposes. These disks are referred as double-sided disks. Double-sided disks may be used in a disk drive for double-sided recording. 
         [0006]    Conventional double-sided processing of hard memory disks involves a number of discrete steps. Typically, twenty-five substrate disks are placed in a plastic cassette, axially aligned in a single row. Because the disk manufacturing processes are conducted at different locations using different equipment, the cassettes are moved from work station to work station. For most processes, the substrate disks are individually removed from the cassette by automated equipment, both sides or surfaces of each disk are subjected to the particular process, and the processed disk is returned to the cassette. Once each disk has been fully processed and returned to the cassette, the cassette is transferred to the next work station for further processing of the disks. 
         [0007]    More particularly, in a conventional double-sided disk manufacturing process, the substrate disks are initially subjected to data zone texturing. Texturing prepares the surfaces of the substrate disks to receive layers of materials which will provide the active or memory storage capabilities on each disk surface. Texturing may typically be accomplished in two ways: fixed abrasive texturing or free abrasive texturing. Fixed abrasive texturing is analogous to sanding, in which a fine grade sand paper or fabric is pressed against both sides of a spinning substrate disk to roughen or texturize both surfaces. Free abrasive texturing involves applying a rough woven fabric against the disk surfaces in the presence of a slurry. The slurry typically contains diamond particles, which perform the texturing, a coolant to reduce heat generated in the texturing process and deionized water as the base solution. Texturing is typically followed by washing to remove particulate generated during texturing. Washing is a multi-stage process and usually includes scrubbing of the disk surfaces. The textured substrate disks are then subjected to a drying process. Drying is performed on an entire cassette of disk drives at a time. Following drying, the textured substrate disks are subjected to laser zone texturing. Laser zone texturing does not involve physically contacting and applying pressure against the substrate disk surfaces like data zone texturing. Rather, a laser beam is focused on and interacts with discrete portions of the disk surface, primarily to create an array of bumps for the head and slider assembly to land on and take off from. Laser zone texturing is performed one disk at a time. The disks are then washed again. Following a drying step, the disks are individually subjected to a process which adds layers of material to both surfaces for purposes of creating data storage capabilities. This can be accomplished by sputtering, deposition or by other techniques known to persons of skill in the art. Following the addition of layers of material to each surface, a lubricant layer typically is applied. The lubrication process can be accomplished by subjecting an entire cassette of disks to a liquid lubricant; it does not need to be done one disk at a time. Following lubrication, the disks are individually subjected to surface burnishing to remove asperities, enhance bonding of the lubricant to the disk surface and otherwise provide a generally uniform finish to the disk surface. Following burnishing, the disks are subjected to various types of testing. Examples of testing include glide testing to find and remove disks with asperities that could affect flying at the head/slider assembly and certification testing which is writing to and reading from the disk surfaces. Certification testing is also used to locate and remove disks with defects that make the surface unuseable for data storage. The finished disks can then be subjected to a servo-writing process and placed in disk drives, or placed in disk drives then subjected to servo-writing. The data zone texturing, laser zone texturing, scrubbing, sputtering, burnishing and testing processes are done one disk at a time, with each surface of a single disk being processed simultaneously. 
         [0008]    Although the active materials and manufacturing processes, by their nature, are difficult and expensive to employ, over the years, the technology used to manufacture hard memory disks has rapidly progressed. As a result, the density of information that can be stored on a disk surface is remarkable. Indeed, double-sided disks used in personal computers have much greater storage capacity than most consumers require during the useful life of the computer. Consumers thus are forced to pay substantial amounts for excess storage capacity and the components to access that excess storage capacity. This has caused some disk drive manufacturers, in some current applications, to manufacture and sell disk drives which utilize only one side of a double-sided disk for storage purposes or which use the good side of a double-sided process disk where one surface passed certification testing and the second surface failed. In either case, the second surface, despite being fully processed, is unused. However, the disk drive manufacturer reduces its cost by eliminating the mechanical and electrical components needed to access the unused disk surface. These disk drives are referred to as single-side drives and are typically used in low-end or economy disk drives to appeal to the low cost end of the marketplace. Although this approach may reduce some cost, it does not reduce the wasted cost of manufacturing the unused storage surface of each disk. Thus, substantial savings can be achieved by not only manufacturing disks with a single active or functional side, but doing so in a cost-effective manner. 
         [0009]    In contrast to a double-sided disk, a single-sided disk D s  has only one functional memory surface with active recording materials M. (See,  FIGS. 4-6 .) It is not a double-sided process disk where one side is not accessed or where one side has failed testing. Rather, manufacturing processes are applied in a controlled manner only to one side of the disk using unique single-sided processing techniques. In contrast to conventional double-sided disks, active recording materials are only applied to, and full processing is only conducted on, one side of the disk. Thus, substantial savings are achieved by eliminating processing the second side of each disk. 
         [0010]    Additionally, the present embodiments achieve advantages by utilizing conventional double-sided disk manufacturing equipment and processes, with limited modification. The present invention enables simultaneous processing of two substrate disks through the same equipment and processes used to manufacture double-sided disks. Simultaneously processing two substrate disks results in the production of two single-sided disks in the same time and using essentially the sale equipment as currently is used in the production of one double-sided disk. However, each single-sided disk has only a single active or functional surface. For illustrative purposes  FIG. 7  shows a side-by-side schematic representation of the processing of one double-sided disk D d , depicted on the left side of  FIG. 7 , versus the simultaneous processing of two single-sided disks D s , depicted on the right side of  FIG. 7 . In each case, the double-sided disk or the two single-sided disks are subjected to the same process steps  1  through N, but the single-sided disk processing produces two disks in the same time the double-sided disk processing produces one disk. 
         [0011]    A benefit provided by simultaneous single-sided processing of disks is a substantial cost savings achieved by eliminating the application of materials to and processing of one side of each disk. A further, and potentially significant cost savings can be achieved by utilizing existing double-sided disk processing equipment, with limited modification, to process pairs of single-sided disks. A still further benefit is a substantial increase in production (or reduction in processing time depending upon perspective). By utilizing existing double-sided disk processing equipment, approximately twice the productivity of a conventional double-sided production process is achieved (on the basis of numbers of disks produced) in the production of single-sided disks. Moreover, these increased productivity levels are achieved at approximately the same material cost, excepting the substrate disk, as producing half as many double-sided disks. 
         [0012]    The simultaneous processing is achieved by combining two substrate disks together into a substrate disk pair or disk pair. A disk pair is two substrate disks that are oriented in a back-to-back relationship with the back-to-back surfaces either in direct physical contact or closely adjacent with a slight separation. The separation can be achieved with or without an intervening spacer. The substrate disk pair progresses through each process step in much the same way as one double-sided disk, but with only the outwardly facing surface of each disk in the pair being subjected to the full process. Thus, the outwardly facing surface of each pair becomes the active or functional surface and the inwardly facing surface of each pair remain inactive or non-functional. 
         [0013]    For convenience and understanding, the following terms will have the definitions set forth: 
         [0014]    a) “R-side” and “L-side” refer to the active side and inactive side of a disk, respectively. R-side is the side that does or will have active recording materials and memory capability. The R-side may also be referred to as the active or functional side. The L-side is the side that has little or no active recording materials or memory capabilities; it is non-functional or inactive from a data storage stand point. 
         [0015]    b) “Merge” means to bring two disks closer together to form a pair of disks, a disk pair or a substrate pair. 
         [0016]    c) “Demerge,” conversely, means that a merged pair of disks is separated from each other. 
         [0017]    d) “Disk” means a finished memory disk and all predecessor configurations during the manufacturing process starting with a substrate disk and progressing to a finished memory disk, depending upon the context of the sentence in which it is used. 
         [0018]    e) “Disk pair” or “substrate pair” means two disks positioned in contact merge, gap merge or spacer merge orientation. 
         [0019]    f) “Double-sided disk” means a single disk which has been subjected to double-sided processing, whether or not both sides of the disk have passed testing or only one side has passed testing. 
         [0020]    g) “Gap merge” means a pair of disks that have been merged, but a space is maintained between the two merged disks. One or more spacers may or may not be used to maintain the gap or space. Gap merge includes both concentric and non-concentric merge. It should be understood that there is no precise dimension or limit to the space between the disks that causes them to be gap merged. Gap merge also includes the situation where the gap between the disks gradually decreases from one perimeter edge to the opposite perimeter edge of the disks when the two disks are angled toward each other. An example is when the bottom perimeter edges of the disks are spaced apart and the upper perimeter edges are in contact. 
         [0021]    h) “Single-sided disks” means a single disk which has been subjected to single-side processing, where only one surface of the disk is fully processed. 
         [0022]    i) “Spacer merge” means a spacer body is used to create spacing between two gap-merged disks. 
         [0023]    j) “Contact merge” means a merged pair of disks where the inside surface of each disk is in contact with the inside surface of the other disk. Contact merge includes concentric and non-concentric merge. 
         [0024]    k) “Concentric merge” means that two merged disks have the same axis and, assuming the two disks have the same outside diameter and inside diameter (as defined by the center aperture), their outer and inner perimeter edges are aligned. 
         [0025]    l) “Concentric contact merge” means a pair of disks that are oriented in both a contact merge and a concentric merge. 
         [0026]    m) “Non-concentric merge” or “off-centered merge” means the two merged disks are not concentric to each other or their perimeter edges are not aligned. 
         [0027]    n) “Non-concentric contact merge” means the two contact merged disks are not concentric to each other or their perimeter edges are not aligned. 
         [0028]    Referring to  FIG. 9 , a cross-section of a pair of gap-merged disks is shown. The R-side (active or functional side) is the outwardly facing surface R of each disk within the pair. The L-side (inactive or nonfunctional side) is the inwardly facing surface L of each disk within the pair. In comparison, a cross-section of a pair of concentric contact merged disks is shown in  FIG. 8 . The relative orientation of the R-side and L-side of each disk remains the same, however, the L-side of each disk of the pair are in contact and the outer and inner perimeter P of each disk is aligned with the outer and inner perimeter P of the other disk. 
         [0029]    A conventional double-sided disk is shown in  FIG. 10 . The left side surface is referred to as the “A” side and the right side surface is referred to as the “B” side. Both the A and B sides are subjected to processing, including the addition of active or magnetic materials. In contrast, with reference to  FIGS. 8 and 9 , the R-side of each disk in a pair of disks is oriented on the outside of the pair and is subjected to processing in the same fashion as the A and B sides of a double-sided disk. Conversely, the L-side of each disk in a pair of disks is oriented on the inside of the pair and is not subjected to full processing in the same fashion as the A and B sides of a double-sided disk. 
       SUMMARY OF THE INVENTION 
       [0030]    The present embodiments are generally directed to methods and apparatus for combining or separating disk pairs simultaneously. 
         [0031]    In some embodiments a method of manufacturing disks is provided, including steps of: processing a plurality of merged pairs of the disks in a carrier, wherein spacings between adjacent pairs of the disks are greater than spacings between disks forming each pair; contactingly engaging the disks in groupings of the pairs at a first common radial position and in groupings of individual disks at a second common radial position, making the spacings between disks forming each pair greater at the second common radial position than at the first common radial position; aligning a mandrel with the disks; and supporting the disks on the mandrel in an even spacing by withdrawing the contactingly engaging step. 
         [0032]    In some embodiments a manufacturing apparatus for handling disks disposed in merged pairs in a carrier is provided, wherein spacings between adjacent pairs of the disks are greater than spacings between disks forming each pair. The apparatus includes a first disk contacting surface defining a first cavity that is sized to receivingly engage a selected one of the pairs of disks. A second disk contacting surface defines second and third cavities that are sized to receivingly engage individual disks of the selected pair of disks, wherein disks that are operably engaged in the cavities are spatially separated more adjacent the second disk contacting surface than at the first disk contacting surface. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0033]      FIG. 1  is a front elevation of a double-sided process disk. 
           [0034]      FIG. 2  is a cross-section taken along line  2 - 2  of  FIG. 1 . 
           [0035]      FIG. 3  is a partial cross-section taken along line  3 - 3  of  FIG. 2 . 
           [0036]      FIG. 4  is a front elevation view of a single-sided disk. 
           [0037]      FIG. 5  is a cross-section taken along line  5 - 5  of  FIG. 4 . 
           [0038]      FIG. 6  is a partial cross-section taken along line  6 - 6  of  FIG. 5 . 
           [0039]      FIG. 7  is a schematic of a process for manufacturing double-sided disks, on the left, and a schematic of a process for manufacturing single-sided disks, on the right. 
           [0040]      FIG. 8  is a cross-section of a pair of disks in concentric contact merge. 
           [0041]      FIG. 9  is a cross-section of a pair of single-sided disks in a gap merge orientation. 
           [0042]      FIG. 10  is a cross-section of a pair of single-sided disks in a spacer merge orientation. 
           [0043]      FIG. 11  is a schematic top view of a transfer station illustrating one embodiment of the present invention. 
           [0044]      FIG. 12  is a schematic end view of embodiments of the present invention showing a cassette containing 25 pairs of contact merge disks ready for demerging. 
           [0045]      FIG. 13  is a schematic end view of the embodiment of  FIG. 12  showing 25 pairs of disks engaging a demerge tool. 
           [0046]      FIG. 14  is a schematic front view of the embodiment shown in  FIG. 13 . 
           [0047]      FIG. 15  is a partial front elevation of the lift saddle of the embodiment shown in  FIG. 14 . 
           [0048]      FIG. 16  is a partial end elevation of the lift saddle shown in  FIG. 15 . 
           [0049]      FIG. 17  is a partial front elevation view of the demerge tool of  FIG. 14 . 
           [0050]      FIG. 18  is a partial end elevation view of the demerge tool of  FIG. 17 . 
           [0051]      FIG. 19  is an exploded front view of the demerge tool of  FIG. 17 , prior to demerging a pair of contact merge disks. 
           [0052]      FIG. 20  is an exploded front view of the demerge tool of  FIG. 17 , showing a pair of disks in a demerged state. 
           [0053]      FIG. 21  is a schematic end view of the embodiment shown in  FIG. 12 , showing the 25 pairs of demerged disks engaged by a mandrel. 
           [0054]      FIG. 22  is a schematic end view of the embodiment shown in  FIG. 12 , showing 25 pairs of disks positioned in a transfer cassette. 
           [0055]      FIG. 23  is a schematic end view of the embodiment of  FIG. 12 , showing every other disk removed from the transfer cassette by a transfer lifter. 
           [0056]      FIG. 24  is a partial end elevation of  FIG. 23 , showing the disks removed from the transfer assembly by the transfer lifter. 
           [0057]      FIG. 25  is a partial front view of  FIG. 24 , showing one disk removed from the transfer cassette by an individual lift saddle of the transfer lifter. 
           [0058]      FIG. 26  is a cross-section taken along the line  26 - 26  of  FIG. 23 . 
           [0059]      FIG. 27  is a schematic end view of the embodiment of  FIG. 12 , showing one-half of the disks being placed in a first cassette. 
           [0060]      FIG. 28  is a schematic end view of the embodiment of  FIG. 12 , showing a mandrel engaging the remaining disks in the transfer cassette. 
           [0061]      FIG. 29  is a schematic end view of the embodiment of  FIG. 12 , showing the remaining disks placed in a second cassette. 
           [0062]      FIG. 30  is a schematic end view of the embodiment of  FIG. 12 , showing 25 disks aligned in one direction in the first cassette, and 25 disks aligned in the opposite direction in the second cassette; it also illustrates the first stage of second embodiments of the present invention used for merging disks or substrate disks. 
           [0063]      FIG. 31  is a schematic end view of the embodiments of  FIG. 30 , showing the disks of one cassette engaged by a mandrel. 
           [0064]      FIG. 32  is a schematic end view of the embodiments of  FIG. 30 , showing all of the disks from the second cassette positioned in a transfer station cassette. 
           [0065]      FIG. 33  is a schematic end view of the embodiments of  FIG. 30 , showing a mandrel engaging all of the disks in the first cassette. 
           [0066]      FIG. 34  is a schematic end view of the embodiments of  FIG. 30 , further showing the disks from the first cassette engaged by the transfer lifter. 
           [0067]      FIG. 35  is a schematic end view of the embodiments of  FIG. 30 , showing all of the disks from the first and second cassettes positioned in a transfer cassette. 
           [0068]      FIG. 36  is a schematic end view of the embodiments of  FIG. 30 , showing all of the pairs of disks from the transfer cassette engaged by a mandrel. 
           [0069]      FIG. 37  is a schematic end view of the embodiments of  FIG. 30 , showing all of the disks from the first and second cassettes merged as disk or substrate disk pairs in a single cassette. 
           [0070]      FIG. 38  is a side elevation view of second embodiments of a demerge tool. 
           [0071]      FIG. 39  is a side elevation view of a pair of demerged disks or substrate disks engaged by a mandrel. 
           [0072]      FIG. 40  is a front elevation view of the embodiments of  FIG. 39 . 
       
    
    
       [0073]    It should be understood that the drawings are not necessarily to scale. In certain instances, details which are not necessary for an understanding of the invention or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the claim scope is not necessarily limited to the particular embodiments illustrated herein. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0074]    In general terms, the apparatus or workstation for simultaneously combining or separating disk pairs is illustrated in  FIG. 11 . The apparatus consists of a three-axis robot  10  with a vertical arm  12  with a disk carrying mandrel  14 . In one embodiment, the mandrel is configured to accommodate 25 pairs of disks (50 total). However, it should be appreciated that the number of disks can vary from one pair to as many pairs as are contained in a cassette. The mandrel may be circular in cross-section, as shown in many of the figures herein. The mandrel may also be semi-circular in cross-section as shown in  FIG. 40 , or it may be a two-pronged V-shape or a three-pronged shape as shown in co-pending U.S. Pat. No. 7,052,739 entitled “Method of Lubricating Multiple Magnetic Storage Disks in Close Proximity, filed May 9, 2003, the entirety of which is incorporated herein by reference as if fully stated herein, and which patent is owned by Assignee. 
         [0075]    The apparatus also includes a load lifter  16 , a transfer lifter  64 , a demerge tool  20 , and four disk handling stations  22 ,  24 ,  26  and  28 . Station  24  is also known as the transfer station. Station  26  is also known as the R-station and station  28  is also known as the L-station. The labels R-station and L-station are in reference to the R-side and L-side of a single-sided disk. Because the cassettes position disks in a single row, the cassette at the R-station has the R-side of the disks facing forward and the cassette at the L-station has the L-side of the disks facing forward. In other words, the disks in the cassette at the R-station and L-station face in opposite directions. The reason for this will become evident upon review of the following description. 
         [0076]    For purposes of the following description, it will be assumed that the disks are 95 millimeters in diameter and that the disks are approximately 0.050 inches thick. However, the present embodiments are not limited to use with this size disk and it is within the scope of the present embodiments to accommodate disks of different sizes. 
         [0077]    The apparatus and process for demerging pairs of single-sided disks will be described first. Disks arrive at the demerge work station in cassettes  30 . The disks will be arranged in pairs in the cassette. The pairs may be in contact merge or gap merge orientation, or they may be in some other orientation. However, the orientation of each successive disk in the cassette will alternate because the disks will have been processed in pairs, with the R-side of each disk facing outwardly of the pair (see  FIGS. 8 ,  9 ). The objective is to separate the disk pairs and place them in cassettes such that their orientation is the same. This will facilitate subsequent automated handling, such as removing the disks from a cassette and placing them in disk drives. Because the disks are single-sided, it is critical that their orientation be known. Placing a single-sided disk upside down in a disk drive would result in a nonfunctional drive. 
         [0078]    In some embodiments, the cassette will arrive from testing with the pairs of disks in a contact merge orientation. Separating pairs of contact merged disks is, generally, a multi-step process. Initially, as shown in  FIG. 12 , a cassette  30  containing pairs of contact merge disks is positioned at the load station  22 . The cassette  30  contains an open bottom and open top for access to the disks, which are arranged in an aligned single row. A load lifter  16  is located underneath the load station  22 . The load lifter  16  is configured to engage and accommodate all of the pairs of contact merged disks in the cassette  30 . As should be appreciated, the number of disks in the cassette may vary, and the size of the cassette may vary. The present embodiments are not restricted to any particular number of disks or any particular size of cassette. In illustrative embodiments, the present apparatus utilizes cassettes that accommodate 25 pairs of disks (50 total disks), as conventional double-sided disk processing cassettes typically hold 25 double-sided disks. Preferably, each pair of disks will be positioned in a cassette within a space of approximately 0.25 inches, as one double-sided disk typically occupies the same space in a conventional double-sided disk processing cassette. Various cassette designs are disclosed and described in co-pending U.S. patent application Ser. No. 10/435,227 entitled “Cassette for Holding Disks of Multiple Form Factors” (Publication No. US-2004-0069662), filed May 9, 2003; U.S. patent application Ser. No. 10/435,360 entitled “Method of Merging Two Disks Concentrically Without Gap Between Disks” (Publication No. US-2004-0016214)), filed May 9, 2003; and, U.S. patent application Ser. No. 10/435,161 entitled “W-Patterned Tools for Transporting/Handling Pairs of Disks” (Publication No. US-2003-0209421), filed May 9, 2003, each of which is incorporated herein by reference in its entirety as if fully stated herein. All of these applications are commonly owned by the Assignee. 
         [0079]    With reference to  FIGS. 14-16 , the load lifter  16  includes a main body portion  32  with a disk contacting surface  34 . The disk contacting surface  34  is curved to correspond with the radius of the disks. The disk contacting surface  34  further includes a series of grooves or channels  36  formed by wedges or teeth  38 . As the disks resident in the cassette  30  are in a contact merge orientation, the width of each groove  36  corresponds to approximately the thickness of two disks. Each groove  36  is formed between the sloped sidewalls  40  of adjacent wedges  38 . The sidewalls  40  join at a top ridge  42 . The distance between adjacent ridges  42  is 0.25 inches. 
         [0080]    As illustrated in  FIGS. 14 ,  15  and  18 , positioned above the load station  22  is a demerge tool  20 . In illustrative embodiments, the demerge tool has a main body  46  with a disk contacting surface  48  curved to correspond with the radius of the disks. The disk contacting surface  48  also includes a series of grooves or channels  50  formed by a series of triangular teeth or wedges  52 . These wedges  52  are spaced in a predetermined manner to align with the interface  44  between the L-side surfaces of each pair of contact merged disks and the space  54  between each pair of disks. As can be appreciated, there are twice as many teeth  52  as teeth  38  because the demerge tool  20  places a tooth  52  between every disk and the lift saddle  16  places a tooth  38  between pairs of disks. The demerge tool  20  is positioned so that the wedges  52  align with the vertical plane defined by the L-side interface of each pair of contact merged disks. 
         [0081]    In operation, and as shown in  FIGS. 13-20 , a lift rod  56  lifts the load lifter  16  while the demerge tool  20  remains stationary. As the contact merged disks are brought into contact with the wedges  52  of the demerge tool  20 , the wedges  52  force the disks to separate. Since the active side (the R-side) of each disk within a pair faces outwardly of the pair, there is little chance of damaging the active surface of the disk during the demerge process. Chamferred outside perimeter edges of the disks facilitate demerge and separation of the disks. 
         [0082]    Next, as shown in  FIG. 14 , the robot  10  moves to insert the mandrel  14  through the center aperture on all disks while they are maintained between the demerge tool  20  and the load lifter  16 . Due to the separation between the disks created by the demerge tool  20 , as shown in  FIG. 20 , a gap now exists between every disk. The mandrel  14  is then raised slightly to contact the upper internal edge of the aperture. The mandrel  14  includes at least one row of teeth  58 . The mandrel may have two or three rows of teeth, or may be semicircular. In illustrative embodiments, the teeth  58  are 0.125 inches apart, spaced evenly. One tooth  58  is positioned between each disk and each disk is positioned in a separate disk receiving groove  60 . A more complete description of the details of a disk carrying mandrel is in U.S. Pat. No. 7,052,739 entitled “Method of Lubricating Multiple Magnetic Storage Disks in Close Proximity,” filed May 9, 2003, which is incorporated herein by reference as if fully stated herein, and which application is owned by the Assignee. As seen in  FIG. 21 , once the disks are supported by the mandrel  14 , the load lifter  16  lowers and leaves the disks suspended from the mandrel. The robot  10  then moves all disk pairs to a position above the transfer station  24  where it lowers the disks into a transfer cassette  62  ( FIG. 22 ). The transfer cassette is configured to support the disks in an evenly spaced distribution. The robot  10  retracts from the center aperture of the disks, leaving the disks supported in the transfer cassette  62  as seen in  FIG. 22 . 
         [0083]    A transfer lifter  64  is positioned beneath the transfer cassette as shown in  FIG. 22 . It includes a plurality of lift rods  66  with individual disk saddles  68  disposed at the top of each lift rod  66 . The number of lift rods and lift saddles is equal to one-half the number of disks in the cassette. More specifically, the individual lift rods  66  and lift saddles  68  are positioned beneath every other disk in the transfer cassette  62 . As previously described, the orientation of the disks alternates from one end of the cassette to the other. The first disk in the cassette has its R-side facing forward and the next disk has its L-side facing forward. Accordingly, the R-side of one half of the disk in the cassette  62  face one direction and the R-side of the other disks face in the opposite direction. Thus, the lift rods and lift saddles are positioned to engage all of the disks in the transfer cassette having the same orientation. 
         [0084]    At this point, the transfer lifter  64  moves upwardly and engages every other disk. The transfer lifter  64  continues its upward movement and removes every other disk. This is shown in  FIGS. 23-25 . Thus, all of the disks that are oriented with their R-side facing in the same direction are elevated above the cassette, leaving behind all of the disks with their R-side facing in the opposite direction. (See  FIG. 26 .) 
         [0085]    With the similarly oriented disks elevated above the transfer cassette  62  by the transfer lifter  64 , the robot  10  positions the mandrel  14  in the center aperture of the elevated disks to engage these disks with the mandrel  14 . (See  FIGS. 23 ,  26 .) Once the disks are loaded on the mandrel  14 , the transfer lifter  64  lowers to a position beneath the transfer cassette  62 . The robot  10  moves to station  26  or the R-station, where a disk cassette  70  is positioned. The disks supported on the mandrel  14  are loaded in this cassette  70  ( FIG. 27 ). The robot  10  then returns to the transfer station  24  and engages the remaining, oppositely oriented disks ( FIG. 28 ). The robot  10  moves these disks to station  28 , or the L-station, and loads these disks in a cassette  72  positioned at that location ( FIG. 29 ). The previous pairs of contact merge disks are now separated and loaded in two separate cassettes, with the disks in each cassette oriented in the same direction, but with the disks in cassette  70  having the R-side facing forward in  FIG. 29  and the disks in cassette  72  having the L-side facing forward in  FIG. 29 . As the cassettes are typically symmetrical, one of the cassettes can be rotated 180 degrees and the two cassettes will contain identically oriented single-sided hard disks. These cassettes  70 ,  72  are now available for transfer to a different station for further processing and the robot  10  returns to its base position ( FIG. 30 ). 
         [0086]    The demerge process can be utilized following completion of disk processing. Specifically, at the end of the manufacturing process, one cassette will contain a plurality of pairs of finished single-sided disks. As previously described, the disks may be in a contact merge orientation, although they could also be in a gap merge orientation. In any event, the disks must be reorganized such that they can be easily and effectively placed in disk drives by manual or automated means. The removal and placement of single-sided disks from a cassette into a disk drive is simplified if the disks in the cassette are similarly oriented, i.e., all the disks in the cassette have their R-side facing the same direction. Such is not the orientation when a full cassette arrives at the demerge station containing pairs of finished single-sided disks. However, at the end of the demerge operation, the disks have been placed in two cassettes  70 ,  72  with the R-side of every disk in the same cassette facing the same direction. These disks can more easily be loaded in disk drives without misorienting the disk in the drive. 
         [0087]    The apparatus and method of the present embodiments may also be used for merging pairs of disks. An example would be at the beginning of the manufacturing process for single-sided disks. Typically, the first process is data zone texturing. Data zone texturing begins with a conventional, highly polished, two-sided substrate disk. Because processing has not yet commenced, the direction the substrate disks face is irrelevant; both sides of the substrate disk are the same. However, the orientation of the cassettes in the substrate disk is important. Preferably, the disks are arranged in pairs, in a gap merge orientation. However, the polishing process typically places disks in a conventional double-sided disk cassette, with 25 substrate disks in a cassette, equally spaced apart with one substrate disk every 0.25 inches. The merge process will combine two conventional cassettes of substrate disks, with a substrate disk positioned every 0.25 inch, into a single cassette with the substrate disks positioned in pairs, with the pairs in gap merge orientation. However, if preferred for other reasons, the substrate disks could be positioned in pairs in a contact merge orientation or equally spaced. The merge process requires multiple steps. The spacing and dimensions addressed below are in the context of 95 millimeter diameter disks with a thickness of approximately 0.05 inches. Spacing can vary from these dimensions. 
         [0088]    The merge process is essentially the demerge process in reverse. The merge process begins by having two cassettes of equal number of substrate disks or disks, equally spaced, loaded at input stations  26  and  28  as shown in  FIG. 30 . If the cassettes  70 ,  72  contain virgin substrate disks, it does not matter how they are positioned at stations  26  and  28 . However, if the cassettes contain partially or fully processed single-sided disks, orientation of the cassettes  70 ,  72  is critical. In such a case, cassettes  70  and  72  are loaded such that the orientation of the R-side of the disks face oppositely of each other. For example, the cassettes are loaded so that the orientation of the R-side (the active side) of the disks in cassette  70  at station  26  face toward the front in  FIG. 30 , and the R-side (the active side) for disks in cassette  72  at station  28  face toward the rear in  FIG. 30 . This orientation is required so that when combined, each disk pair will have their R-sides (the active surfaces) facing outward and the L-side (the inactive or nonfunctional side) facing inwardly of the pair. 
         [0089]    With reference to  FIG. 31 , the robot  10  proceeds to station  28 , inserts the mandrel  14  into the center aperture of the disks or substrate disks, engages all disks in the cassette  72  and removes them from the cassette. The robot  10  then loads these disks into the transfer cassette  62  at station  24  ( FIG. 32 ). Next, the robot  10  will similarly engage the disks and the cassette  70  at station  26  ( FIG. 33 ) and transport them to a position above the transfer station  24  (FIG.  34 ). The transfer lifter  64 , positioned beneath the transfer cassette  62  at station  24 , will extend to a position above the previously loaded disks at station  24 , where the individual disk saddles  68  will engage the disks suspended from the mandrel  14  ( FIGS. 24-26 ). The transfer cassette  62  is designed to space the initially loaded disks from cassette  72  with a gap of approximately 0.125 inches between disks. The individual disk saddles  68  and lifter rods  66  are designed such that the individual disk saddles  68  fit between the disks previously loaded in the transfer cassette  62 . (See  FIG. 25 .) The saddles  68  rise up through the open top of the cassette  62 , between the previously loaded disks, to their upper most limit ( FIGS. 24 ,  25 ). The robot  10  then refracts the mandrel  14 . The saddles  68  then lower the disks into the transfer cassette  62  at station  24  ( FIG. 35 ). Compared to a conventional cassette  70 ,  72  where the substrate disks are positioned one every 0.25 inches, the transfer cassette positions two disks or substrate disks every 0.25 inches. Transfer cassette  62  now conforms twice the number of substrate disks or disks positioned in a conventional double-sided disk cassette. 
         [0090]    The robot  10  moves to the center of the transfer cassette  62 . The mandrel  14  is inserted through the aperture of all disks, engages and lifts all disks. ( FIG. 36 .) In the preferred embodiment, all of the disks are equally spaced apart. The robot  10  moves all of the disks to station  22 , and lowers the disks into a cassette  30 . ( FIG. 37 .) If different spacing is desired, depending upon the spacing of the cassette  30  that will ultimately receive these combined disks, a mandrel  14  with differently oriented teeth  58  can be substituted. 
         [0091]    The design of the merge cassette  30  will facilitate placement of the disks in cassette  30 . The merge cassette may be configured to position the substrate disk or disks in equal spacing, or in pairs having a gap merge orientation or a contact merge orientation. If equal spacing is desired, the merge cassette  30  is configured identical to the transfer cassette  62  and the mandrel  14  makes a simple transfer from the transfer cassette to the merge cassette. If gap merge orientation is desired, the merge cassette may be configured as shown and described in co-pending U.S. patent application Ser. No. 10/435,161 entitled “W-Patterned Tools for Transporting/Handling Pairs of Disks” (Publication No. US-2003-0209421), filed May 9, 2003, which is incorporated herein by reference in its entirety as if fully stated herein, and which application is owned by the Assignee. If contact merge orientation is desired, the merge cassette may be configured as shown and described in co-pending U.S. patent application Ser. No. 10/435,360 entitled “Method of Merging Two Disks Concentrically Without Gap Between Disks” (Publication No. US-2004-0016214)), filed May 9, 2003, which is incorporated herein by reference in its entirety as if fully stated herein, and which application is owned by the Assignee. It should be understood that the embodiments described are not exhaustive of the configurations that will facilitate desired orientation of the disks in the cassette. 
         [0092]    In further embodiments, the mandrel  90 , lift saddle  92  and demerge tool  94  may be configured to manipulate fewer than all the disks in a cassette. As illustrated in  FIGS. 38-40 , in some embodiments the alternative design is configured to handle one pair of disks at a time, rather than an entire cassette. With reference to  FIG. 38  and with respect to demerging, the lift saddle  92  lifts a pair of contact merge disks from a cassette until the upper perimeter edges of the disks engage the demerge tool. The lift saddle has a single channel or groove  96  to hold the disk pair in a contact merge orientation. The demerge tool has two channels or grooves  98 , separated by a wedge  100 . The wedge will create an initial separation of the disks as the lift saddle  92  raises the disk pair into contact with the demerge tool. 
         [0093]    Once a separation has occurred between the disks, a mandrel  90  will engage the disks at the center aperture  102 . The mandrel will have two grooves  104  separated by a wedge  106 . The wedge will fit between the separated disks, as shown in  FIG. 39 , to support the disk pair and allow the lift saddle to return to its position beneath the cassette. The physical spacing created between the disks by the wedge  106  is dictated by the orientation of the cassette where the disks will be deposited. The mandrel  90  will then move the disk pair to a receiving cassette. 
         [0094]    For merging purposes, the mandrel  96  will engage two adjacent disks in the same cassette. Again, the spacing of the two grooves and center wedge will determine the spacing of the two disks on the mandrel. The mandrel can act like a merging tool and bring two disks closer together, such as into a gap merge orientation. This spacing should match the spacing of the target cassette. In some embodiments, when working with substrate disks at the beginning of the manufacturing process, it will be desired to position the two substrate disks in a gap merge orientation. Therefore, the mandrel will merge the two disks into a gap merge orientation and then deposit them in a cassette having the same gap merge orientation. By working with two disks at a time, there is no need to use a transfer cassette. 
         [0095]    As should be appreciated, these embodiments will operate much the same way as the embodiments shown in  FIGS. 11-37 , except only one disk at a time. The cassettes will need to index each time a disk pair is removed to position the next disk pair over the lift saddle  92  or over a transfer lifter (not shown). Alternatively, the lift saddle and transfer lifter can move incrementally underneath their respective cassettes. 
         [0096]    It should be appreciated that some embodiments of the present invention are intended to accommodate 25 pairs of disks, or 50 individual disks, allowing the cassettes to be of the same size as conventional cassettes used in conventional double-side disk processing. It should be appreciated that the present embodiments will work with any number of disks. Similarly, the diameter of the disks may vary as needed. The design concept of the present embodiments can easily be extended to cover a wide range of different disk spacing configurations for incoming and outgoing cassettes and the number of disk pairs the apparatus can handle. 
         [0097]    The foregoing discussion has been presented for purposes of illustration and description. The foregoing is not intended to limit the embodiments to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the claimed invention are grouped together in one or more embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of any of the disclosed embodiments. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as separate embodiments of the invention. 
         [0098]    Moreover, though the description of the claimed invention has included description of one or more embodiments and certain variations and modifications, other variations and modifications are within the scope of the invention, e.g. as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.