Patent Publication Number: US-2007095993-A1

Title: Moving apparatus

Description:
TECHNICAL FIELD  
      The current invention relates to a moving apparatus, more specifically, a moving apparatus which moves a personal computer vertically.  
     BACKGROUND OF INVENTION  
      Generally, office workers work with a personal computer (PC) placed on their desks. For example, in case of a desk-top type computer, at least a display and a keyboard, in some cases the computer main unit, are placed on a desk. In addition, in case of a laptop-type computer, the entire laptop is placed on a desk.  
      However, office workers are not always using their PC when they are working. For example, when reading a document or taking notes while on the phone, the time when not using a computer is not necessarily short. Thus, if a PC is placed on a desk even when it&#39;s not in use, it takes up working space on the desk.  
      The current invention is made with a view of above fact and its objective is to propose a moving apparatus which enables to effectively utilize work space on a desk.  
     BRIEF SUMMARY OF THE INVENTION  
      Such objective can be achieved by the current invention described below. (1) A moving apparatus comprising a placing portion to place a personal computer or a keyboard for a personal computer, a moving portion to move the placing portion from a use position for using the placed personal computer or keyboard, to any non-using position located different from the use position, and a fixing means to fix the moving portion to a desk.  
      (2) The moving apparatus according (1), wherein the placing portion comprises a control means to control the placing portion from exceeding a predetermined angle when the placing portion is positioned at the using position.  
      (3) The moving apparatus according to (1) or (2), further comprising a permission means to permit the movement of the placing portion wherein the moving portion can move, at least, from one position to another among the use position and the nonuse position when a permission for moving is given by the permission means.  
      (4) The moving apparatus according to any of (1) to (3) comprises a storage portion that is provided at least internal of the moving portion to store at least one of a power cable of the personal computer or a signal cable of the personal computer.  
      (5) A moving apparatus comprising a platform, a placing portion having a placing face to place a placing object, an elevation oscillating member having the rear end portion oscillatably connected to the platform and the front end portion oscillatably connected to the placing portion, an extension means comprised between the elevation oscillating member and the platform, a locking means to lock the position of extension means, an operating means to switch said lock means to a lock state and a release state that allows extension and wherein said elevation oscillating member, said platform, and said extension means comprises a triangular link structure.  
      (6) The moving apparatus according to (5), wherein the placing portion comprises either of a first power terminal or a first signal terminal; and the platform comprises a second power terminal conducting the first power terminal or a second signal terminal conducting the first signal terminal.  
      (7) The moving apparatus according to (6) above wherein, the electrical wire conducting the first power terminal and the second power terminal or the electrical wire conducting the first signal terminal and the second signal terminal is inserted into the elevation oscillating member.  
      (8) The moving apparatus according to any one of (5)-(7) above, wherein the elevation oscillating material therein comprises an inserting portion to insert an electric wire.  
      (9) The moving apparatus according to any one of (5)-(8) above, wherein said extension means comprises a cylinder, a piston head moves within cylinder chamber of the cylinder, a piston rod wherein one end is connected to the piston head and the other end is protruding outside of the cylinder, a channel to circulate liquid filled in a cylinder chamber between a first cylinder chamber which expands its volume when extended, and a second cylinder which reduces its volume when extended, divided by the piston, and wherein the locking means is a switching valve comprised on the channel and the operating means operates the switching valve to open and close.  
      (10) The moving apparatus according to (9) above, wherein the piston head comprises a communicating passage communicating a first cylinder chamber with a second cylinder chamber and a safety valve provided to the communicating passage, wherein the safety valve is in an open state when the pressure in the first cylinder chamber exceeds a predetermined pressure.  
      (11) The moving apparatus according to (10) above wherein the communicating passage comprises an aperture which is operated after the safety valve is opened.  
      According to the invention of (1), since the placing portion to place a personal computer or a keyboard for a personal computer can be moved from a use position to a nonuse position with the moving portion, work space on the desk can be effectively used when the personal computer is not in use by moving the placing portion from the use position to the nonuse position. Further, because the current invention detachably fixes the moving portion to the desk, the moving apparatus can be detached from the desk so that the desk and the personal computer can be moved separately, which will be useful when relocating, or replacing the desk.  
      According to the invention of (2), the control means can prevent the placing portion from exceeding a predetermined angle when positioned in the use position, and prevent a personal computer from dropping from the placing portion when moved from the nonuse position to the use position.  
      According to the invention of (3), the placing portion can be stabilized in a relevant place since it can be moved at least one position from another among the use position and the nonuse position when moving is permitted by the permission means.  
      According to the invention of (4), since the storage portion to store at least one of the power wire of the personal computer or the signal wire of the personal computer is provided internal to the moving portion, these wires can be prevented from entangling and becoming an obstacle.  
      According to the invention of (5), the placing portion moves up and down by the elevation oscillating member oscillating in a vertical direction on the platform. Since the link structure is comprised by the elevation oscillating member, the platform, and the extension means, a oscillating position of the elevation oscillating member can be provided by expanding and contracting the extension means. And, by locking the position of the extension means with the locking means, fix the oscillating portion of the elevation oscillating member, which enables the placing portion to be fixed at the desirable height.  
      According to the invention of (6), since the power terminals and the signal terminals are provided to the placing portion, a LAN cable or a power wire for the personal computer and so on can be connected on the placing portion without hanging down from the placing portion. Also, since the platform has the terminals that conduct each of the power terminal and the signal terminal of the placing portion, connection with a communication wire to another device or a power wire can be made with these second terminals, so that inconveniences, such as a power wire connected to a personal computer interfering with the elevation operation, can be prevented.  
      According to the invention of (7), the electrical wires itself will not be exposed to the outside since the wire conducting the first power terminal and the second power terminal or the wire conducting the first signal terminal and the second signal terminal are inserted into the elevation oscillating member, so that it will not prevent elevating operation.  
      According to the invention of (8), the power wires will not prevent the elevating operation by inserting power wires into the inserting portion in the elevation oscillating member. The power wires connected to a personal computer can also be inserted through the inserting portion. In this way, no terminals are needed for the placing portion.  
      According to the invention of (9), the placing portion can be fixed certainly in a desirable position with the extension means comprised of a cylinder and a piston.  
      According to the invention of (10), since the safety valve is provided, damage to the mechanism can be prevented when placing a placing object exceeding a tolerable weight because the safety valve operates to move the placing portion downward. Also, when rapid vibration, such as earthquake, is applied, the placing portion can certainly be moved downward because it has structure that opens with an instantaneous increase of cylinder inner pressure from impact, and retains that open state after that.  
      According to the invention of (11), the aperture operates after the safety valve is opened, so that a sudden drop of the placing portion is restrained, which leads to prevent placed objects, such as a personal computer, from damage. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a side view of a moving apparatus.  
       FIG. 2  is a bottom view of a moving apparatus.  
       FIG. 3  is an obliquely upward view of a moving apparatus.  
       FIG. 4  is a view of a placing portion with a personal computer placed thereon.  
       FIG. 5 (A) is a view of a placing portion in the nonuse position and  5 (B) is a view of a placing portion in the use position.  
       FIG. 6 (A) is another view of a placing portion in the nonuse position and  6 (B) is another view of a placing portion in the use position.  
       FIG. 7  is a view showing a deformation example of a moving apparatus (specially a fixation device).  
       FIG. 8  is a partial bottom view of a placing portion showing an operation means.  
       FIG. 9  is a perspective view showing a mounting structure of placing portion.  
       FIG. 10  is an overall side view showing a structure of another embodiment.  
       FIG. 11  is a plane view as well.  
       FIG. 12  is a plane view of a cover member.  
       FIG. 13  is an overall prospective view of a moving apparatus.  
       FIG. 14  is a view showing a cross section frame format of a structure for cylinder construction.  
       FIG. 15  is a partial enlarged cross section view of a piston head portion.  
       FIG. 16  is a partial enlarged cross section view of a piston head portion.  
       FIG. 17  is a cross section side view showing a structure of operation means.  
       FIG. 18  is a A-A cross section view of an operation means.  
       FIG. 19  is an overall prospective view of a cooling equipment. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      The present invention will hereinafter be more specifically described in reference to drawings. As shown in  FIG. 1 , the moving apparatus of the current invention comprises a placing portion  18  (see also  FIG. 4 ) for placing a personal computer or laptop type, a moving portion  12  to move the placing portion  18  between a use position for using the placed personal computer and an arbitrary nonuse position different from the use position, and a fixation device  14  to fix the moving portion  12  to a desk  16  detachably as a fixing means.  
      The fixation device  14  comprises a contact portion  14 C with angled “U”-shaped cross section, and its upper face contacting with the lower face of a base  20  of the moving portion  12 , and the upper inner face contacting with the surface of desk  16 . This contact portion  14   c  is fixed to the desk  16  by contacting a front end portion  14 B with the back face of the desk by a screw  14 A, resulting the moving portion  12  fixed to the desk  16 . As shown in  FIG. 2 , the moving portion  12  is rotatably attached to the base  20 , a prop portion  22  which is rotatably attached to the base  20  through link  26 , and the prop  22  through the link  28 , and comprises the support portion  24  supports the placing portion  18 .  
      As shown in  FIG. 2 , the prop  22  as a elevation oscillating member comprising two prop members  22 A and  22 B. Two prop members  22 A and  22 B are installed on the base  20  which is a platform, and the support portion  24 , in a way that retains a predetermined spacing.  
      A link  25  is provided to a position that moved from the center of two prop member  22 A and  22 B towards the support portion  24  side. The link  25  has a fixation portion  32 D installed rotatably. The fixation portion  32 D has the supporting portion  32 C which supports one end of the piston  32 B, fixed. The other end of the piston  32 B is located in the cylinder  32 A. The end that is opposite from the end that piston of the cylinder  32 A is rotatably fixed to the link  30 A which is provided to the support base  30  fixed to the base  20 .  
      The cylinder  32 A is filled with oil. And the other end of the piston  32 B separates a chamber of the cylinder  32 A into a side that closer to the piston than the other end of the piston  32 B and a side that closer to the support base  30  than the other end of the piston  32 B. Each separated chamber is filled with oil, so that the piston  32 B can not move within the cylinder  32 . However, in this embodiment, the other end of piston  32  is provided with a switching valve which is not shown. So, when this switching valve is opened, oil can move within the separated chambers and the piston  32 B can move within the cylinder  32 . This switching valve is connected to the button operation portion  40  attached to the placing portion  18  through the wire  42 . That is, when the button operation portion  40  operated, the switching valve is opened with the wire  42  which enables the piston  32 B to move within cylinder  32 . In addition, the button operation portion  40  corresponds to the permission means. Moreover, a flange is formed on the narrow side of near side of the placing portion  18 , and constructed to prevent a placed personal computer from dropping when the placing portion is tilted. A light  181  is provided to the lower face of placing portion  18  and constructed to illuminate the downside of placing portion  18  when the placing portion  18  is at a nonuse position. When the placing portion  18  is in nonuse position, the surface of desk tends to be dark because it hides in shade of the placing portion  18 , however, the lighting  181  can maintain the luminance of desk.  
      As shown in  FIG. 3 , a upper projection  34  on opposite side from the front end of supporting portion  24 , a lower projection  36  on the portion where the supporting member  22  mounted to the link  26 , and a wire  38  connected to the upper projection  34  and the lower projection  36 , are provided to the side opposite from the prop portion  22  shown in  FIG. 2 . In this way, since the upper projection  34  is on an opposite side from the front end of supporting portion  24  and the lower projection  36  is on the portion where the supporting member  22  is mounted to the link  26 , and are connected by the wire  38 , the supporting portion  24 , therefore, the placing portion  18  are regulated not to tilt exceeding a predetermined angle λ (see  FIG. 1 ) against the prop portion  22 . In addition, the upper projection  34 , the lower projection  36 , and the wire  38  comprise a control means.  
      When above cylinder  32  is comprised with a pneumatic cylinder, by impinging the air pressure to the direction of the expansion of the cylinder, and impinging this force to the direction that pushes up the placing portion from lower side, it can be utilized as a supporting force to elevate the placing portion with a heavy placed object. This enables a strengthless operator, such as a child or an senior to utilize the apparatus easily. Also, by using the cylinder, it becomes easier to fix (lock) the position of the above placing portion  18  at an arbitrary position.  
      As shown in  FIG. 2 , the storage portion  100  which stores a power wire  102  of the personal computer, is provided to the inside of each prop member  22 A and placing portion  18 . In this embodiment, an outlet  110   a  and  100   b  (see  FIG. 4 ) is provided to connect a jack of the power wire that directly connected to the personal computer placed on the placing face of placing portion  18 . One end of the storage portion  100   a  reaches the outlet  110   a  and the other end reaches an opening  100 A provided close to the base  20  of prop member  22 A. The outlet  110   a  and/or  110   b  (see  FIG. 4 ) on one end of the storage portion  100 , as shown in  FIG. 2 , is connected to a jack  106  through the power wire  102  that is stored in the storage portion and extends externally thorough the opening  100 A, and this jack  106  is connected to a main outlet (external source such as lighting power) which is not shown.  
      Further, the storage portion  100  can be provided also within the fixation device  14  or only within the prop member  22 A. In addition, when provided only within the prop member  22 A, the outlet  110   a  can also be provided on the side face of prop member  22 A. Also, the storage portion  100  is not limited to a power wire, along with this, or instead of this, a signal cable of a personal computer can be stored. The signal wire can be, for example, a printer cable.  
      Also, in this embodiment as shown in  FIG. 4 , the placing face of placing portion  18  has the mouse storage box  132  fixed to store a mouse  130 . In addition, a hook to hang a mouse can be provided instead of the mouse storage box  132 .  
      Next, operation of the current embodiment will be explained. First, for example, the placing portion  18  is positioned at the nonuse position (arbitrary position) shown in  FIG. 5  (A). When the button operation portion  40  is operated in this condition, the piston  32 B can be moved within the cylinder  32 A as described above. So a user moves the placing portion  18  to the use position shown in  FIG. 5  (B) in this condition and stop operating the button operation portion  40 . When there is no operation of the button operation portion  40 , the piston  32 B can not be moving within the cylinder  32 A. Therefore, the placing portion  18  is stably positioned at the use position.  
      When there is no necessity for use of PC, again, operate the button operation portion  40  to position the placing portion  18  to a nonuse position ((arbitrary position) see  FIG. 6  (A)). An example of moving the placing portion  18  from either one of use position or non use position to another when the placing portion  18  is controlled to a predetermined angle by the wire  38  etc., explained in above. In addition, the placing portion  18  can be tilted below the predetermined angle in this embodiment as shown in  FIG. 6  (B).  
      As explained above, in this embodiment, because the placing portion that has personal computer placed can be moved from use position to nonuse potion by the moving portion, work space on the desk can be effectively utilized by moving the placing portion to the nonuse position when the personal computer is not in use. Moreover, in this embodiment, the moving apparatus can be detached from the desk because the moving portion is detachably fixed to the desk, so that the desk and the personal computer can be moved separately, which will be useful when relocating, or replacing the desk.  
      Further, the placing portion can be prevented from tilting exceeding a predetermined angle by a control means, such as wire, when the placing portion is positioned at the use position, so that the personal computer can be prevented from dropping from the placing portion when moved from nonuse position to use position. Also, the lighting  181  can be provided to the lower side of the placing portion  18 . This will be used as a lighting to illuminate the desktop when positioning the placing portion  18  at a nonuse position. Additionally, the placing portion can be moved from either one of use position or nonuse position to another when movement is permitted by the button, so that the placing portion can be stabilized to the position.  
      Also, in the embodiment described above, the storage portion  100  is provided to inside of each prop member  22 A and placing portion  18  to store the power wire  102  of personal computer, so that it prevent the power wire from becoming an obstacle. Further, the mouse storage box  132  is fixed on the placing face of the placing portion  18 , it also prevent a mouse and its signal sire to be come obstacle when moving the placing portion in this case.  
      The method of the fixation device  14  adopted in above embodiment is that fix the contacting portion  14 C to the desk  16  by the screw  14 A, however, the current invention is not limited to this, and for example, a inserting portion  140  which extends from base portion  20 , can be provided as shown in  FIG. 7 . In this case, provide an insertion hole  16 S to the desk  16  for insertion portion  140  to be inserted. Therefore, the moving portion can be fixed to the desk detachable by inserting the inserting portion  140  to the inserting hole  16 S. Also, a binding bolt  16 R is threaded to the inserting hole  16  S from outside as a positioning fixing means, and the positioning is made by threading the binding bolt  16 R and contact the front end with the inserting portion  140  after deciding a position of horizontal direction for the placing portion  18 . In addition, a construction can also be as follows, a spring inserted into inserting hole  16 S, and a compression spring inserted between the inserting portion  140  and bottom of the inserting hole  16 S. In this case, the spring absorbs a vibration from earthquake and damage to the personal computer placed on the placing portion  18  can be prevented.  
      As shown in  FIG. 8 , an operating means  5  capable of operating with a light operation load can be provided to the button operating portion  40 . In this configuration example, the button operating portion  40  is provided in the position where hides completely on the lower side of placing portion  18 , and the button  41  that is provided to be able to appear and disappear, is arranged to be able to move advance and retreat towards the side of placing potion  18 .  
      The operating means  5  has an arm  51 , a supporting portion  52  which ocillatably supports the arm, a contacting portion  53  provided to the rear end of arm  51 , and operating portion  54  provided to the front end portion. The arm  51  is provided to the bottom face of placing portion  18  and oscillatably supported through supporting point  52 . The position of supporting portion  52  is located where distance from the supporting portion  52  to the operating portion  54  on front end portion is longer than the distance to the contacting portion  53 . Also, the operation portion  54  is hidden in the lower side of placing portion  18  at the non-use position and positioned near the end portion of placing portion  18 .  
      The contacting portion  53  contacts the front end of button  41 , and has a structure that moves along the advance and retreat direction of the button  41  by oscillation of the arm  51 . In such construction, when the operating portion  54  is pulled outward (lateral of the placing portion  18 ), the arm  51  is oscillated, the contacting portion  53  moves the button  41  to the direction for pressing in, and the button  41  is pressed in by the contacting portion  53 . This enables the vertical movement of the placing potion  18 . Also, non operating position of the operating portion  54  can be the position slightly exposed from the end of placing portion  18 . In this case, position of the operating portion  54  can easily be recognized visually and it make easier to find the operating portion  54 . And, since the distance from the supporting point  52  to the operating portion  54  is longer than the distance to the contacting portion  53 , the operating load impinging on the operating portion is decreased by the principle of leverage, and the button  41  can be pressed in with a mild operation, which make the elevation operation of the placing portion  18  easy. In addition, such operating means  5  can be provided not only to the lateral of the placing portion  18 , but also to the end of near side.  
      A bias member, such as a spring, is housed in the cylinder  32 A, and it can be comprised to bias the piston  32 B in projection direction. By comprising in this way, the force is always acting in the direction to elevate the placing portion  18  and, it can also act as a supporting force when pushing a weighty personal computer in an upward position. Moreover, when the permission means is released and allowed to move, it can act as a buffering means without rapidly dropping the placing portion  18  by the weight of the personal computer.  
      Also, the placing portion is comprised to place a laptop type personal computer in aforementioned embodiment, however, the current invention is not limited to this, and it can be comprised to place a keyboard of a desk top type personal computer. In addition, a signal wire of the keyboard can be housed in above storage portion in this case.  
       FIG. 9  is a perspective view showing a mounting structure of placing portion  18 . A groove  241  is formed on the supporting portion  24  in an anteroposterior direction on the face opposite to the placing portion  18  and a projection  182  which is intruded into the groove  24 , is formed on the placing portion  18 . Since the cross section of projection  182  is formed in a wedged shape, the placing portion does not secede from the supporting portion  24  except for the inserting direction when inserted into the groove  241 , and comprised in a way that movable in an anteroposterior direction (inserting direction). By comprising in such way, unteroposterioorly moving the placing portion  18  at a using position and the placing portion  18  can be moved to the position desirable for a user. Also, the placing portion  18  can be replaced depending on the size of placing object by making it possible to mount detachably to the prop portion  22 , so that the versatility of the apparatus of the current invention can be improved.  
       FIG. 10  is an overall side view of the moving apparatus showing a structure of other embodiment,  FIG. 11  is also a overall plane view,  FIG. 12  is a plane view of a cover member, and  FIG. 13  is a overall prospective view of the moving apparatus. The moving apparatus in this embodiment comprises a platform  61 , an elevation oscillating member  65 , a cylinder mechanism  7  as a extension means, and positioning device  77  as a locking means. The platform  61  comprises a mechanism to fix on the end portion of top panel of desk. The platform  61  has an upper substrate  612  and a lower substrate  611  comprised parallel to each other. The lower substrate  611  has a rotating shaft  624  penetrating the lower substrate  611 , and a turning operation portion  621  connected to the rear end of rotation shaft  624 , and binding portion  623  connected to the top end of rotation shaft  624 , and it has a construction that the binding portion moves in advance and retreat direction of the upper substrate by screwing the external thread portion formed on an outer circumference of rotation shaft  64  together with a internal thread portion formed on the lower substrate  611  and operates the turning operation portion  621 . The platform  61  is tightly fixed onto the desk end portion by holding the top panel of desk, which is inserted between the lower substrate  612  and the binding portion  623 , between the lower face of upper substrate  612  and binding portion  623 , and binding the same.  
      On the other hand, a turning support shaft  631  is installed upright onto the upper substrate  612  and a pedestal  63  is connected to the turning support shaft  631  rotatably. The pedestal  63  is centering the turning support shaft  631  and rotatably supported on the upper substrate  612 . The pedestal  63  has a concave portion  632  in a mortar form slant downward towards the turning support shaft  631 , and a supporting member  64  which is installed upward. The supporting portion  64  turns as a unit with the pedestal  63 . A connection supporting point  641  is provided to the rear end portion of supporting member  64 , and this connection supporting point  641  is connected to one end of a cylinder mechanism  7  which is described later, as an extension means. This connection supporting point  641  is located on axis line of turning support shaft  631 .  
      The support shaft  642  is inserted into the front end of supporting member  64  and the elevation oscillating member  65  is oscillatably connected to the support shaft  642 . The elevation oscillating member  65  is comprised with a pair of arm member,  65   a  and  65   b . Each rear end portion of each arm member  65   a  and  65   b  is connected to both ends across the supporting member  64 . A front end supporting shaft  651  is inserted into the front end portion of each arm member  65   a  and  65   b  at the same time, and this front end supporting shaft  651  vertically oscillatably supports the connection supporting member  67  which supports the placing portion  68 .  
      While the connection supporting member supports  67  the placing portion  68  from bottom, it has a function to connect the elevation oscillating member  65  turnably to the placing portion  68 , so that the placing face of placing portion  68  maintains a constant angle. The placing portion  68  has a placing face  66  on upper side to place a placing object, and is provided in a way so that it can maintain an axial direction of the elevation oscillating member  65  against the connection supporting member  67 . On the other hand, a link  66  is installed between the connection support member  67  and the front end of supporting member  64 . That is, the front end of connection link  66  is connected to a connection pin  661  provided on the connection support member  67  and the rear end is connected to a connection pin  643  provided on the front end of supporting member  64 . Such connection link  66 , elevation oscillating member  65 , connection supporting member  67  and supporting member  64  comprise a link mechanism having four turning supporting points, and an action of this link mechanism maintains the placing face  681  of placing portion  68  at a fixed angle (for example, horizontal) consistently, regardless of the oscillating portion of the elevation oscillating member  65 . The connection link  66  can be comprised with a material that bend, such as wire or chain, or a bar material comprised with rigid body, such as metal. In case of a material with flexibility, the placing portion  68  can be oscillated upward. In case of rigid body, position of the placing portion  68  is fixed.  
      The rear end portion of elevation oscillating member  65  has a pin constructed between the arm member  65   a  and  65   b  and a connection supporting point  652  is provided. A cylinder mechanism  7  as a extension means is constructed between the connection supporting point  652  and  641 . This cylinder mechanism  7  having a structure that expand and contract along with the vertical oscillation of the elevation oscillating member  65 , and the length of expansion can be fixed with a locking means which will be described hereinafter. This structure enables the placing portion  68  to be fixed at arbitrary height.  
       FIG. 14  is a cross section pattern diagram showing the structure of cylinder mechanism  7 . The cylinder mechanism  7  is an extension means and has a cylinder  71  and a piston  72  inserted into the cylinder  71 . One end of the cylinder  71  is connected to a connection supporting point  641  and the piston rod  722  is protruding on the other end. The piston head  722  is housed in the cylinder chamber  711  within the cylinder  71 . A sealing material  721  is inserted between the inner wall of cylinder chamber  711  and the piston head  720 , and the cylinder chamber  711  is divided into chamber  711   a  and chamber  711   b  by the piston head  720 . In such cylinder mechanism  7 , the total length provided by the cylinder  71  and piston rod  722  is changed by changing the position of the piston  72  to the cylinder  71 . Also, the total length of cylinder mechanism  7  is locked by fixing the position of piston head  720 . Such lock means  73  that locks the length of cylinder mechanism  7  has a bypass passage  73  and a switching valve  735 .  
      Each of chamber  711   a  and chamber  711   b  is filled with oil and the oil circulates between chamber  711   a  and chamber  711   b  through the bypass passage  733  which is a channel formed within the cylinder. The chamber  711   a  is contracted when the piston head  720  moves to the direction that contracts total length, and expanded when the piston head  720  moves to the direction that expands. The chamber  711   b  is opposite of the chamber  711   a.    
      The bypass passage  733  has apertures  731  and  732  respectively on the both end of cylinder chamber  711  and communicating chamber  711   a  with chamber  711   b . A switching valve  735  is provided to the bypass passage  733  and oil in the bypass passage  733  is controlled by switching this switching valve  735 . For example, circulation of the oil in the bypass passage  733  is shut off when the switching valve  735  is closed, so that the piston head  720  can not moved within the cylinder chamber  711  and the position can be fixed. That is, the length of cylinder mechanism  7  (extension means) that defined by the cylinder  71 , and the piston rod  722  is locked. Switching of the switching valve  735  is operated by a operating means which will be described hereinafter. Opening of switching valve  735  is operated by advance and retreat of the front end of operating wire  94 . Well known structure is used to the structure of the switching valve  735  it self, therefore the explanation is omitted.  
      As shown in  FIG. 15 , the safety device  74  is provided to the piston head  720 . This safety device  74  comprises a communication passage  741  communicates the chamber  711   a  with chamber  711   b , a valve chest  743  provided on chamber  711   b  side, and a valve element  742  housed within the valve chest  743 . The valve element  742  is a sphere, and formed in a diameter slightly larger than the inner diameter of hole  744  which communicate the valve chest  743  with the chamber  711   b.    
      A sealing material  745  is inserted on the chamber  711   a  side between the valve chest  743  and the valve element  742  to prevent oil leak. To explain the operation of this safety device  74 , a load applied to the direction compress the cylinder mechanism  7 , so that the pressure in the chamber  711   a  increases when load exceeds the tolerable weight applied on the placing portion, or impact load or dynamic load applied to the vertical direction by the vibration of earth quake. This will increase the force to push out towards the chamber  711   b  side relative to the valve element  742 . Since the inner diameter of the hole  744  is only slightly smaller than the outer diameter of valve element  742 , the hole  744  is expanded and the valve element  742  is contracted by peripheral material of the hole  744 , or an elastic deformation of the valve element  742 , then the valve element  742  is pressed out of the hole  744 . In this way, the communication passage  741  communicates the chamber  711   a  and the chamber  711   b , and oil flow from the chamber  711   a  to the chamber  711   b  through the communication passage  741 . At this time, the communication passage  741  functions as an aperture and gives adequate resistance to the flow of oil, so that the placing portion slowly moves down and reaches to the use position without moving down rapidly. The valve element  742  can be comprised by a deformable resin. By changing the resin material or the diameter of hole  744  or valve element  742 , the load to operate the safety device can be changed.  
      Also, as show in  FIG. 16 , form an aperture member  747  and an aperture housing portion  746  on the communication passage  741  side of valve element  742  and a bias member  748  can be provided to bias the aperture member  747  to the chamber a  711   a  side. The aperture housing portion  746  is formed in a length that the aperture member  747  can move adequately. The aperture member  747  has an aperture hole  749  in the center, and pressed to the chamber  711   a  side with the bias member  748 . For example, when impact load is applied lower to the placing portion, the pressure in the chamber  711   a  increases. Since the aperture member  747  can move to the chamber  711   b  direction, the pressure of chamber A  711   a  easily reach the valve element  742  and press the valve element  742  out of the valve chest  743 . In this way, although oil flows from chamber  711   a  to chamber  711   b , the inflow is controlled by the aperture member  747  so that the placing portion moves down slowly and reaches to the use position D. That is, it prevents placed precision devices, such as personal computers from impact due to rapid drop of the placing portion.  
      By providing such aperture mechanism, the pressure from the chamber  711   a  certainly applied to the valve member  742  (that is, the safety device operates certainly) when an impact applied, and an aperture function is operated when the valve element  742  is pressed out, so that descent speed of the placing portion can be reduced sufficiently. Because this valve element  742  will not returned to the original position once opened, it is useful as a safety device operates in case of an earth quake, in the sense that unlike in the case of a pressure exceeds tolerable pressure constantly applied, the valve that is operated by an impact load applied instantaneously will not close thereafter and maintained in the open state.  
      As for earth quake measure, in addition to above, damper SD can be installed between the placing portion  68  and the elevation oscillating member  65   a ,  65   b , as shown with a imaginary line in  FIG. 11 . Such damper SD decrease the horizontal oscillation to the placing portion  68  and prevent a placed object from damage or dropping from the placing portion  68 .  
      The supporting member  64 , the pedestal  63 , and the cylinder mechanism  7  comprised in such way, are housed in inside of the cover member  8 .  FIG. 12  is a plane view of the cover member  8 . The cover member  8  is formed in cylindrical and divided into two cover pieces  81   a  and  81   b  on both side along the center of cylindrical. Each cover piece  80   a  and  80   b  on both sides is respectively provided with outer edge portion  81   a ,  83   a ,  81   b , and  83   b  that are curved in arc, and having partition  82   a  and  82   b  inside. The cover pieces  80   a  and  80   b  on the both side is mounted in the way that bind support member  64  from both side, and the pedestal  63  is housed on the bottom end of cover pieces  80   a  and  80   b  on both side. In a mounted state, form into a cylinder as a whole and the top end portion is a angled opening. Also, a first storage portion  821  is demarcated between partition  82   a  and  82   b  on both side, and the supporting member  64  and the cylinder mechanism  7  are stored within this first storage portion  821 . Large portion of the supporting member  64  and cylinder mechanism  7  is covered by the cover member  8  which prevents disfigure, and improves sensuousness. Also, the cover member  8  turns as a unit with the pedestal  63  and the supporting member  64 .  
      Divider  84   a  and  84   b  are provided between partitions  82   a ,  82   b  and outer edge portions  81   a ,  83   a ,  81   b ,  83   b . In this way, a second storage portion  811   a  by the outer edge portion  81   a , partition  82   a  and divider  84   a , and a third storage portion  831   a  by the outer edge portion  83   a , partition  82   a  and divider  84   a , are demarcated respectively on the cover piece  80   a . In the similar manner, a second storage portion  811   b  by the outer edge portion  81   b , partition  82   b  and divider  84   b , and a third storage portion  831   b  by the outer edge portion  83   b , partition  82   b  and divider  84   b , are demarcated respectively on the cover piece  80   b.    
      Each storages portion stores attached equipment accordingly. In this embodiment, the operating means  9  of cylinder mechanism  7  is stored in the third storage portion  831   a .  FIG. 17  is a cross section side view showing a structure of operation means  9  and  FIG. 18  is a A-A cross section view, as well. The operating means  9  comprises a main body  91  in cylinder form, a spline shaft  92  and a sliding member  93  externally mounted on the spline shaft  92 . The slide member  93  and the spline shaft  92  is stored in the main body  91 , and a operating portion  921  is protruding in the front end of spline shaft  92 , and a handle  922  is provided on the circumference face of operating portion  921 . The spline shaft  92  is turnably supported through a bearing  911  within the main body  91 . The sliding member  93  is fitted at outside of the spline shaft  92 .  
      A key groove  931  is formed on the inner circumference of slide member  93  in the axis direction of spline shaft  92  fitted to the spline  923 , sliding member  93  turns as a unit with spline shaft  92  and comprised in the a way that able to slide in axis direction. On the other hand, a key groove  932  in spiral form is formed on the circumference face of sliding member  93 . The key groove  932  is fitted to a key  912  which is formed protruded to the inner wall of main body  91 . The slide member  93  has a structure that moves in an axis direction while turning by the fitting of this key  912  and the key groove  932 , and turning of spline shaft  92 .  
      One end of the slide member  93  is closed and the closed end  933  is contacting with the contacting member  941  which is connected to the rear end of wire  94  that impinges the switching valve  735 . When the slide member  93  is slide to the direction of wire  94 , the contacting member  941  is pushed in and the wire  94  is pushed out to the direction of switching valve  735 . This movement of the wire  94  opens the switching valve  735 . The wire  94  is biased towards the constant operating means  9  from the switching valve  735  side, and the contacting member  941  biases the slide member  93  towards front end, and the slide member  93  is positioned on the side that the handle  922  of splined shaft  92  is positioned, when in non operating state.  
      Such operating means  9  as above is housed in the third storage portion  831   a  of cover member  8  and only the operating portion  921  and handle  922  are provided protruding outside. In this way, the operating means  9  and wire  94  hide inside of the cover member  8 , so that sensuousness of the apparatus can be secured.  
      In addition to this, the main unit of operating device can be stored in the cover member  8  to operate the personal computer to be placed on the placing portion  68 . For example, storing the connecting device for a pointing device, such as mouse, within the cover member  8  and provide its connection terminal to the circumference face of cover member  8 . Or, a receiving portion for infrared communication can be provided.  
      The personal computer itself is placed on the placing portion  68  and vertically moved, so that the vertical movement is disturbed by wiring connecting a device to operate on desktop and a personal computer when external devices are connected. For this reason, disturbance to the vertical movement can be avoided by providing a connection terminal and a receiving portion to the cover member  8 , and wire these connection terminal with the main unit of personal computer through a cord inserted into the storage portion  100  within the elevation oscillating member  65 .  
      As shown in  FIG. 19 , a cooling device  682  can be provided to the lower side of placing portion  68 . The cooling device  682  has a baffle case  683 , a fan  684  which is a blowing means, a cooling fin  684 . The baffle case  683  is fixed on the lower side of placing portion  68  and multiple fins  684  connected to the lower face of placing portion  68  are stored within the baffle case  683 . The fan  684  is provided to the corner of baffle case  683  to blow air into the baffle case  683 .  
      The flow of blown air is circulated within the baffle passage  685  formed between the cooling fins  684  while drawing heat from the cooling fin  684 , flown to an exhaust outlet  686 , and exhausted. The placing portion  68  is preferably a metal with good heat conductance, such as aluminum or copper. By providing such cooling device  682 , electric devices, such as placed personal computer, can be cooled.  
      In addition to this, provide a sensor to the placing portion  68  to detect if a object is placed thereon, store a control device inside of the cover member  8 , the control devices receives detection signal of this sensor and determines whether an object is placed on the placing portion  68 , and a structure with a release switch and an alarm device can be added to inside of the cover member  8 . The control device detects the time point when the object can no longer be detected from the state that an object is placed on the placing portion, and comprises a timer to measure elapsed time from that point. The control device operates an alarm device at the point when predetermined time has passed and sends out warning, except for a case where a release switch is pressed before predetermined time (for examples, 15 seconds) from the start of measurement passes. This will exercise an anti-theft action to the object placed on the placing portion  68 .