Patent Publication Number: US-2009229110-A1

Title: Tool for use in removing head

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to tools, and more particularly to a tool that is suited for removing a head part from an actuator of a magnetic storage apparatus. 
     2. Description of the Related Art 
     A magnetic storage apparatus has a plurality of magnetic recording media and a plurality of heads for recording information on and reproducing information from the magnetic recording media. In a magnetic disk apparatus (or a magnetic disk drive), a plurality of magnetic disks are provided coaxially at predetermined intervals. One head is provided on a tip end of a head actuator, with respect to a recording surface of each of the magnetic disks. A plurality of head parts, each including the head, are stacked. For this reason, a head assembly formed by the plurality of head parts is referred to as a Head Stack Assembly (HAS). For example, when the head fails or the serviceable life of the head ends, it is possible to replace only the head part which includes the head which failed, for example. A head clip is used when the head part is removed from the actuator and when mounting the head part on the actuator. The head clip enables the removal and mounting operations to be performed in a state where the contact or collision of the heads is prevented by the head clip. 
       FIG. 1  is a perspective view showing an example of a conventional head clip. A head clip  1  shown in  FIG. 1  includes a positioning shaft  2 , a head fixing arm  3 , and a plurality of fingers  4 . 
       FIGS. 2A ,  2 B and  3  are diagrams for explaining attachment of the head clip to an actuator.  FIG. 2A  is a side view showing a state where the head clip  1  is attached to an actuator  11 , and  FIG. 2B  is a top view showing a state before the head clip  1  is attached to the actuator  11 . As shown in  FIGS. 2A and 2B , the actuator  11  has an actuator block  12 , a coil  13 , a unit bearing  14 , a head clip insertion hole  15 , a suspension  16  and a head assembly  17 . A plurality of suspensions  16  and head assemblies  17  are provided on the actuator  11 . 
     The head clip  1  is attached to the actuator  11  by inserting the shaft  2  into the hole  15  from the top of the actuator  11  and turning the head clip  1  about the shaft  2 .  FIG. 3  is a bottom view of the actuator  11  showing the manner inn which the head clip  1  is attached to the actuator  11 . In the state where the head clip  1  is attached (or inserted) to the actuator  11 , the finger  4  is inserted between two mutually adjacent suspensions  16 , in order to prevent heads  18  which are provided on tip ends of the suspensions from making contact or colliding with each other in the head assembly  17 . 
       FIG. 4  is a side view for explaining a state where one head part is removed from the head assembly  17  or, a state where one head part is mounted on the head assembly  17 .  FIG. 5  is a top view showing one head part.  FIGS. 6A and 6B  are diagrams, on an enlarged scale, showing a part of the head part surrounded by a dotted line in  FIG. 5 .  FIG. 6A  is a top view of a base plate portion, and  FIG. 6B  is a side view of the base plate portion. 
     A base plate  171  having a boss part  172  with a hole formed therein is provided on a base part of a head part  17 - 1  shown in  FIG. 5 . As shown in  FIG. 6B , when mounting the head part  17 - 1  on the actuator  11 , a calking ball  179  of a tool (not shown) is inserted into the hole of the boss part  172  to spread the inner diameter of the hole, in a state where the boss part  172  fits into an opening in a corresponding engaging part of the actuator  11 , in order to mount the boss part  172  on the corresponding engaging part of the actuator  11 . When removing the head part  17 - 1  from the actuator  11 , a tapered blade of a tool is inserted between the base plate  171  and the actuator  11  from two opposing positions, in order to separate the calked boss part  172  from the corresponding engaging part of the actuator  11  and remove the head part  17 - 1  from the actuator  11 . 
     However, when mounting the head part  17 - 1  on the actuator  11  or, when removing the head part  17 - 1  from the actuator  11 , although the finger  4  of the head clip  1  prevents the collision of the heads  18  that are provided on the opposing sides of the two mutually adjacent suspensions  16 , it is not possible to prevent collision of the opposing sides of the two mutually adjacent suspensions  16  not provided with the heads  18 . Particularly when the head part  17 - 1  is removed from the actuator  11 , the suspension  16  rises from the actuator  11  in a direction indicated by an arrow F in  FIG. 7  when the calked boss part  172  is separated from the engaging part of the actuator  11 , because the rigidity of the suspension  16  is relatively low. Consequently, the suspension  16  pivots clockwise in  FIG. 7  about a pivotal fulcrum which is formed by the finger  4 , and the head part  17 - 1  provided on this suspension  16  easily collides with the adjacent head part  17 - 1 . In other words, the back surfaces of the heads  18  on the mutually adjacent suspensions easily collide with each other.  FIG. 7  is a diagram for explaining the rising of the head part  17 - 1  from the actuator  11 , and shows a side view of the actuator  11  in the state where the head clip  1  is attached thereto. 
     For example, an example of a tool that is used when transporting an actuator assembly is proposed in a Japanese Laid-Open Patent Application No. 2005-174459. 
     Conventionally, even in the state where the head clip  1  is attached to the actuator  11 , the back surfaces of the heads  18  may collide with each other due to the collision of the mutually adjacent suspensions  16  when the head part  17 - 1  is removed from the head assembly  17  or, the head part  17 - 1  is mounted on the head assembly  17 . As a result, there was a problem in that the heads  18  may be damaged, particularly when the suspensions  16  are deformed. Such a problem was also encountered in cases where the head part  17 - 1  is mounted on the actuator  11  by a method other than calking. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a general object of the present invention to provide a novel and useful tool in which the problems described above are suppressed. 
     Another and more specific object of the present invention is to provide a tool which can prevent damage to a head part when an operation is made with respect to the head part of an actuator. 
     According to one aspect of the present invention, there is provided a tool to be attached to an actuator having a rotary fulcrum and heads on a tip end opposite to the rotary fulcrum, the tool comprising a finger configured to be inserted between a first pair of mutually adjacent suspensions which are provided with heads having mutually opposing scanning surfaces; and a partitioning plate configured to be inserted between a second pair of mutually adjacent suspensions which are provided with heads having mutually opposing back surfaces that are on opposite ends from the scanning surfaces. 
     According to one aspect of the present invention, it is possible to prevent damage to a head part when an operation is made with respect to the head part of the actuator. 
     Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing an example of a conventional head clip; 
         FIGS. 2A and 2B  are diagrams for explaining attachment of the head clip to an actuator; 
         FIG. 3  is a diagram for explaining the attachment of the head clip to the actuator; 
         FIG. 4  is a side view for explaining a state where one head part is removed from a head assembly or, a state where one head part is mounted on the head assembly; 
         FIG. 5  is a top view showing one head part; 
         FIGS. 6A and 6B  are diagrams, on an enlarged scale, showing a part of the head part surrounded by a dotted line in  FIG. 5 ; 
         FIG. 7  is a diagram for explaining rising of the head part; 
         FIG. 8  is a plan view showing an example of a magnetic storage apparatus having the actuator; 
         FIG. 9  is a perspective view showing a tool in a first embodiment of the present invention; 
         FIGS. 10A ,  10 B and  10 C are diagrams showing a back plate and a head clip; 
         FIG. 11  is a bottom view showing the actuator for explaining a manner in which a head clip is attached; 
         FIG. 12  is a front view for explaining attachment of the head clip to the actuator; 
         FIG. 13  is a front view, on an enlarged scale, showing a portion of a head part in  FIG. 12 ; 
         FIG. 14  is a side view, on an enlarged view, showing a portion of the head clip in  FIG. 12 ; 
         FIG. 15  is a perspective view showing a tool in a modification of the first embodiment; 
         FIG. 16  is a perspective view showing a tool in a second embodiment of the present invention; 
         FIG. 17  is a front view, on an enlarged scale, showing a calking part of the tool; 
         FIG. 18  is a front view showing a state where the calking part engages a boss part of the actuator; 
         FIGS. 19A and 19B  are diagram showing the calking part on an enlarged scale; 
         FIG. 20  is a perspective view, on an enlarged scale, showing an actuator attaching part of the tool in a third embodiment of the present invention; 
         FIG. 21  is a perspective view, on an enlarged scale, showing the actuator attaching part of the tool; 
         FIG. 22  is a perspective view, on an enlarged scale, showing the actuator attaching part of the tool; and 
         FIG. 23  is a perspective view, on an enlarged scale, showing a portion of a tool in a fourth embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In one embodiment of the present invention, a tool (or jig) is attached to an actuator having suspensions. In a state where the tool is attached to the actuator, each finger of the tool is inserted between mutually adjacent suspensions provided with heads having mutually opposing scanning surfaces, and each partitioning plate of the tool is inserted between mutually adjacent suspensions having mutually opposing back surfaces on the opposite ends from the scanning surfaces. The fingers of the tool support the suspensions, while the partitioning plates of the tool restrict the suspensions. In this case, the tool having the fingers and the tool having the partitioning plates may be separate tools. 
     The collision of the scanning surfaces of the heads is prevented by the fingers of the tool, and the collision of the back surfaces of the heads is prevented by the partitioning plates of the tool. 
     Next, a description will be given of the tool and operations using the tool, by referring to  FIG. 8  and the subsequent drawings. 
     First Embodiment  
       FIG. 8  is a plan view showing an example of a magnetic storage apparatus having the actuator. In this example, the magnetic storage apparatus is a magnetic disk apparatus using a plurality of magnetic disks as the magnetic recording media. 
     A magnetic disk apparatus  21  shown in  FIG. 8  has a known structure having an actuator  11 , a load and unload mechanism  23 , magnetic disks  25  and the like which are provided on a base  22 . The actuator  11  has the structure described above in conjunction with  FIGS. 2A and 2B , and a detailed description thereof will be omitted. A head  18  is provided on a tip end of a suspension  16  of the actuator  11 . The head  18  records signals on and reproduces signals from the magnetic disk  25  which is rotated by a motor (not shown), in a state where a scanning surface of the magnetic head  18  floats by a predetermined amount from a recording surface of the magnetic disk  25 . The number of suspensions  16  provided on the actuator  11  and the number of heads  18  may be set to any arbitrary numbers which are two or greater. 
     For the sake of convenience, it is assumed that the actuator  11  is a load unload type. Hence, depending on the mode of the magnetic disk apparatus  21 , the head  18  is unloaded from the load and unload mechanism  23  and is moved to a position above the magnetic disk  25  or, the head is moved from the position above the magnetic disk  25  and is loaded onto the load and unload mechanism  23 . A load and unload tab  16 - 1 , which is engageable to the load and unload mechanism  23 , is provided on the tip end of the suspension  16  of the actuator  11 . For example, this load and unload tab  16 - 1  is formed integrally on the suspension  16 . The load and unload tab  16 - 1  is guided along a guiding surface of the load and unload mechanism  23 , to thereby load and unload the head  18  by the load and unload mechanism  23 . In a state where the head  18  is loaded onto the load and unload mechanism  23 , the head  18  is receded to a position avoiding a position above the recording surface of the magnetic disk  25 . 
       FIG. 9  is a perspective view showing a tool in a first embodiment of the present invention. In this embodiment, the present invention is applied to a head clip. A head clip  31  shown in  FIG. 9  has a positioning shaft  32 , a head fixing arm  33 , a plurality of fingers  34 , a plurality of partitioning plates  35 , a knob part  36 , an engaging part  37 , and a back plate  38 . The back plate  38  is connected to the head fixing arm  33 , and each partitioning plate  35  is provided on the back plate  38 . Each finger  34  is inserted between a corresponding first pair of mutually adjacent suspensions  16  which are provided with the heads  18  having mutually opposing scanning surfaces. Each partitioning plate  35  is inserted between a corresponding second pair of mutually adjacent suspensions  16  which are provided with the heads  18  having mutually opposing back surfaces that are on the opposite ends from the scanning surfaces. 
     The material used for parts of the head clip  31  other than the back plate  38  is not limited to a particular material, but it is desirable to form the parts of the head clip  31  other than the back plate  38  from a material which does not easily generate electrostatic. For example, the parts of the head clip  31  other than the back plate  38  is made of a material having a resistance that is approximately 1×10 Ω·m or less. Materials having the resistance that is approximately 1×10 12  Ω·m or less include conductive metals or resins, for example, and such resins include a tool stainless steel STAVAX and such resins include a conductive compound WHISTATT manufactured by Otsuka Chemical Co., Ltd., for example. The parts of the head clip  31  may be formed integrally or, the parts may be bonded to form the head clip  31 . Of course, the part of the head clip  31  which makes direct contact with the actuator  11  may be formed by a material which does not easily generate electrostatic. The back plate  38  may be formed by a transparent plate. In the case of the transparent back plate  38 , the head part  17 - 1  can easily be seen from the outside even in the state where the head clip  31  is attached to the actuator  11 , to thereby improve the operation ease of the operations performed with respect to the actuator  11 . When making the back plate  38  transparent, it is possible to use a conductive transparent material such as a conductive polymer ST-POLY manufactured by Achilles Corporation, for example. 
       FIGS. 10A ,  10 B and  10 C are diagrams showing the back plate  38  and the head clip  31 .  FIG. 10A  shows a side view of the back plate  38 ,  FIG. 10B  shows a front view of the head clip  31 , and  FIG. 10C  shows a top view of the head clip  31 . A tip end portion of each partitioning plate  35  surrounded by a dotted line in  FIG. 10A  has a tapered shape. In addition, a tip end portion of each finger  34  surrounded by a dotted line in  FIG. 10C  has a tapered shape. 
       FIG. 11  is a bottom view showing the actuator  11  for explaining a manner in which the head clip  31  is attached.  FIG. 12  is a front view for explaining attachment of the head clip  31  to the actuator  11 . 
     In  FIG. 11 , the head clip  31  is attached to the actuator  11  in the following manner. That is, the head clip  31  is attached to the actuator  11  by inserting the shaft  32  into the hole  15  from the top of the actuator  11 , and turning the knob part  36  about the shaft  32 . When attaching the head clip  31  to the actuator  11 , each finger  34  is first inserted between the corresponding first pair of mutually adjacent suspensions  16  which are provided with the heads  18  having mutually opposing scanning surfaces, and each partitioning plate  35  is then inserted between the corresponding second pair of mutually adjacent suspensions  16  which are provided with the heads  18  having mutually opposing back surfaces that are on the opposite ends from the scanning surfaces. When the head clip  31  is attached to the actuator  11 , the engaging part  37  engages with a corresponding engaging part  51  of the actuator  11 , and the head clip  31  is provisionally held so as not to easily separate from the actuator  11 . The engaging part  37  of the head clip  37  and the engaging part  51  of the actuator  11  may have any shapes that would enable provisional holding of the head clip  31 , and for example, the engaging parts  37  and  51  may be formed by a combination of a claw part and a recess or, a combination of a projection and a depression. 
     As shown in  FIG. 11 , the tip end portion of each of the fingers  34  and the tip end portion of each of the partitioning plates  35 , which first engage the actuator  11  when attaching the head clip  31  to the actuator  11 , respectively have the tapered shape as surrounded by the dotted lines in  FIGS. 10C and 10A . The tapered shape is not limited to a particular shape, and may be formed by one or a plurality of sloping surfaces or curved surfaces. The tapered shape is provided in order to smoothly and positively insert the fingers  34  and the partitioning plates  35  between the corresponding first and second pairs of suspensions  16  and to prevent damage to the suspensions  16  and the like and to prevent large shock or vibration from being applied to the suspensions  16  and the like, when attaching the head clip  31  to the actuator  11 . 
     In the state where the head clip  31  is attached to the actuator  11 , each finger  34  is inserted between a corresponding first pair  161  of mutually adjacent suspensions  16  which are provided with the heads  18  having mutually opposing scanning surfaces, and each partitioning plate  35  is inserted between a corresponding second pair  162  of mutually adjacent suspensions  16  which are provided with the heads  18  having mutually opposing back surfaces that are on the opposite ends from the scanning surfaces. The finger  34  supports the suspensions  16  forming the first pair  161  at a position between the rotary fulcrum of the actuator  11  and the head  18  along a longitudinal direction of the actuator  11 , and prevents the scanning surfaces of the heads  18  which are provided on the tip ends of the suspensions  16  from colliding with each other. On the other hand, the partitioning plate  35  restricts the suspensions  16  forming the second pair  162  at the tip end of the actuator  11 , and prevents the back surfaces of the heads  18 , that is, the tip ends of the suspensions  16  forming the second pair  162 , from colliding with each other. Even if the suspension  16  on the right side in  FIG. 12  and forming the second pair  162  vibrates or pivots clockwise in  FIG. 12  about a pivotal fulcrum which is formed by the finger  34  due to the reasons described above in conjunction with  FIG. 7 , a displacement of the suspension  16  exceeding a tolerable range is restricted by the partitioning plate  35 , and the displaced suspension  16  will not collide with the suspension  16  (the suspension  16  on the left in  FIG. 12 ) forming the adjacent first pair  161 . 
     When the partitioning plates  35  make contact with the suspensions  16  when attaching the head clip  31  to the actuator  11 , there is a possibility of damaging the suspensions  16 . Hence, in this embodiment, a gap is formed between the tip end portions of the suspensions  16  forming the second pair  162  and the partitioning plate  35  in the state where the head clip  31  is attached to the actuator  11 . 
     Next, a description will be given of an example of the dimensions of various parts of the head clip  31  and the actuator  11 , by referring to  FIGS. 13 and 14 .  FIG. 13  is a front view, on an enlarged scale, showing a portion of the head part  17 - 1  in  FIG. 12 , and  FIG. 14  is a side view, on an enlarged view, showing a portion of the head clip  31  in  FIG. 12 . 
     In  FIG. 13 , A denotes a vertical width of the partitioning plate  35  (length along the longitudinal direction of the actuator  11 ), t denotes a thickness of the partitioning plate  35 , and A 1  denotes a length in the head part  17 - 1  from the tip end of the suspension  16  to the rear end of the head  18  (that is, the end of the head  18  closer to the rotary fulcrum of the actuator  11 ) along the longitudinal direction of the actuator  11 . It is desirable to set the vertical width A and the length A 1  to satisfy A&gt;A 1  in order to completely cover the head  19  by the partitioning plate  35  in the head part  17 - 1 . It is desirable to set the thickness t of the partitioning plate  35  so that the partitioning plate  35  does not make contact with the suspensions  16  in the state where the head clip  31  is attached to the actuator  11 , even if the displacement of the suspensions  16  caused by the insertion of the finger  34  which spreads the suspensions  16  apart and the tolerance of the thickness t of the suspension  16  are taken into consideration. 
     In  FIG. 14 , B denotes a lateral width from the back plate  38  to the lateral end of the partitioning plate  35 , C denotes a length from the lateral end of the partitioning plate  35  to tip end of the finger  34 , D denotes a length of the tapered part at the tip end of the finger  34 , and E denotes a lateral width from the back plate  38  to the tip end of the finger  34 . It is desirable to satisfy the relationships C&gt;D and B=E−C in order for the tapered part of the finger  34  to pass between the first pair  161  of the adjacent suspensions  16  and for the linear part of the finger  34  to begin entering between the first part  161  of the adjacent suspensions  16  before the partitioning plate  35  begins to enter between the second pair  162  of the adjacent suspensions  16 . 
       FIG. 15  is a perspective view showing a tool in a modification of the first embodiment. In  FIG. 15 , those parts that are the same as those corresponding parts in  FIG. 9  are designated by the same reference numerals, and a description thereof will be omitted. In this modification, a head clip  31 A further has a cover  39 . The cover  39  extends in a direction approximately perpendicular to the longitudinal direction of the actuator  11 , and protects the tip end part of the actuator  11  in a state where the head clip  31 A is attached to the actuator  11 . In this example, the cover  39  is integrally provided on the head fixing arm  33 , however, the cover  39  may be a separate body which is connected or bonded to the head fixing arm  33 . By providing the cover  39 , it is possible to more positively protect the head part  17 - 1  in the state where the head clip  31 A is attached to the actuator  11 . 
     According to this embodiment and this modification, the fingers of the tool (head clip  31  or  31 A) prevent the collision of the scanning surfaces of the heads, and the partitioning plates of the tool (head clip  31  or  31 A) prevent the collision of the back surfaces of the heads, when removing the head part from the actuator or when mounting the head part on the actuator. 
     Second Embodiment  
       FIG. 16  is a perspective view showing a tool in a second embodiment of the present invention. In this embodiment, the present invention is applied to a tool (or jig) which removes the head part from the actuator. As shown in  FIG. 16 , a tool  61  has a base  62 , a calking part  63 , a knob  64 , an actuator mounting part  65  and the like. 
       FIG. 17  is a front view, on an enlarged scale, showing the calking part  63  of the tool  61 .  FIG. 17  shows a state where the actuator  11  having the head clip  31  attached thereto is set on the actuator mounting part  65 . the actuator  11  may be set on the actuator mounting part  65  by a known method, and detailed description and illustration of the setting method will be omitted in this specification. By turning the knob  64  in the state where the actuator  11  is set on the actuator mounting part  65 , the calking part  63  moves in a direction so as to engage the head part  17 - 1  of the actuator  11 . In a state shown in  FIG. 18 , the calking part  63  engages the boss part  172  (shown in  FIGS. 6A and 6B ) of the actuator  11 .  FIG. 18  is a front view showing the state where the calking part  63  engages the boss part  172  of the actuator  11 . 
       FIGS. 19A and 19B  are diagram showing the calking part  63  on an enlarged scale.  FIG. 19A  shows a plan view of the tool  61 , and  FIG. 19B  shows a front view of the tool  61 . When removing the head part  17 - 1  from the actuator  11 , a tapered blade  63 A of the calking part  63  of the tool  61  is inserted between the base plate  171  and the actuator  11  from two opposing positions, in order to separate the calked boss part  172  from the corresponding engaging part of the actuator  11  and remove the head part  17 - 1  from the actuator  11 . 
     When removing the head part  17 - 1  from the actuator  11  in this manner, the head part  17 - 1  easily collides with the adjacent head part  17 - 1  as described above in conjunction with  FIG. 7 . However, because the head clip  31  is attached to the actuator  11 , the fingers  34  and the partitioning plates  35  of the head clip  31  prevent the collision of the mutually adjacent suspensions  16 . 
     When mounting the head part  17 - 1  on the actuator  11 , the calking ball of the tool may be used as described above in conjunction with  FIGS. 6A and 6B , to basically perform an operation in reverse to the operation performed using the calking part  63 , and detailed description and illustration of the mounting method will be omitted in this specification. 
     According to this embodiment, the fingers of the tool (head clip  31 ) prevent the collision of the scanning surfaces of the heads, and the partitioning plates of the tool (head clip  31 ) prevent the collision of the back surfaces of the heads, when removing the head part from the actuator or when mounting the head part on the actuator. 
     Third Embodiment  
       FIG. 20  is a perspective view, on an enlarged scale, showing an actuator attaching part of the tool in a third embodiment of the present invention. In  FIG. 20 , those parts that are the same as those corresponding parts in  FIG. 16  are designated by the same reference numerals, and a description thereof will be omitted. 
       FIG. 21  is a perspective view, on an enlarged scale, showing an actuator attaching part  65  of a tool  61 - 1 , and  FIG. 22  is a perspective view, on an enlarged scale, showing an actuator  11  set on the actuator attaching part  65  of the tool  61 - 1 . In  FIGS. 21 and 22 , fingers  134  and partitioning plates  135  provided on the actuator mounting part  65  respectively correspond to the fingers  34  and the partitioning plates  35  of the head clip  31  of the first embodiment. When the actuator  11  is set on the actuator mounting part  65  by a known method, the fingers  134  and the partitioning plates  135  of the actuator mounting part  65  are inserted between the corresponding adjacent suspensions  16  and function similarly to the fingers  34  and the partitioning plates  35  of the head clip  31  of the first embodiment. 
     It is desirable to form the fingers  134  and the partitioning plates  135  from a material which does not easily generate electrostatic. For example, the fingers  134  and the partitioning plates  135  are made of a metal or resin having a resistance that is approximately 1×10 12  Ω·m or less. In addition, the fingers  134  and the partitioning plates  135  may be formed integrally on a part of the actuator mounting part  65 . 
     According to this embodiment, the fingers of the tool (tool  61 - 1 ) prevent the collision of the scanning surfaces of the heads, and the partitioning plates of the tool (tool  61 - 1 ) prevent the collision of the back surfaces of the heads, when removing the head part from the actuator or when mounting the head part on the actuator. 
     Fourth Embodiment  
       FIG. 23  is a perspective view, on an enlarged scale, showing a portion of a tool in a fourth embodiment of the present invention. In  FIG. 23 , those parts that are the same as those corresponding parts in  FIG. 21  are designated by the same reference numerals, and a description thereof will be omitted. 
     In the third embodiment described above, the fingers  134  and the partitioning plates  135  are provided on the tool  61 - 1 . On the other hand, in this fourth embodiment, the actuator  11  is set on a tool  61 - 2  having the partitioning plates  135  in a state where an existing head clip  1  shown in  FIG. 1 , for example, is attached to the actuator  11 . 
     It is desirable to form the partitioning plates  135  from a material which does not easily generate electrostatic. For example, the partitioning plates  135  are made of a metal or resin having a resistance that is approximately 1×10 12  Ω·m or less. In addition, the partitioning plates  135  may be formed integrally on a part of the actuator mounting part  65 . 
     According to this embodiment, the fingers of the tool (head clip  1 ) prevent the collision of the scanning surfaces of the heads, and the partitioning plates of the tool (tool  61 - 2 ) prevent the collision of the back surfaces of the heads, when removing the head part from the actuator or when mounting the head part on the actuator. Further, it is possible to effectively utilize the existing head clip. 
     In the embodiments described above, the actuator  11  is the load and unload type. However, the actuator to which the tools of the described embodiments may be applied is of course not limited to the load and unload type. 
     This application claims the benefit of a Japanese Patent Application No. 2008-068472 filed Mar. 17, 2008, in the Japanese Patent Office, the disclosure of which is hereby incorporated by reference. 
     Further, the present invention is not limited to these embodiments, but various variations and modifications may be made without departing from the scope of the present invention.