Abstract:
A rotary stand S for the electric appliance M designed to enable the electric appliance M to be oriented in a desired direction includes a pedestal  2  having a spherically concave portion and a regulating projection, a mounting plate  4  adapted to support thereon the appliance M, and a clamp plate  6  for clamping the mounting plate  4  between it and the pedestal  2  so that the mounting plate  4  can be swung either leftwards or rightwards and/or tilted up or down. The angle of any one of swing and tilt of the mounting plate  4  is regulated by causing side edges of the regulating projection to engage corresponding inner side edges of a slot defined in the mounting plate  4.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention generally relates to a support assembly for supporting thereon an electric appliance such as, for example, a computer display unit or an audio equipment and, in particular but not exclusively, to a rotary stand for the electric appliance that is effective to improve functionality of the electric appliance by allowing the latter to be adjustable in orientation depending on the site in which the electric appliance is placed.  
           [0003]    2. Description of the Related Art  
           [0004]    The conventional rotary stand is known to include a pedestal formed with a spherically concave portion, and an electric appliance such as, for example, a computer display unit or an audio equipment is mounted thereon through a mounting plate having a concave portion complementary in shape to the shape of the spherically concave portion. The pedestal has a center portion formed integrally with a hollow cylindrical boss that is loosely inserted through an elongated opening defined in a center portion of a mounting plate on which the electric appliance is mounted, with a clamp plate biased by a screwed spring element towards the mounting plate so that the electric appliance on the mounting plate can be tilted up and down and/or swung leftwards and rightwards.  
           [0005]    However, with the conventional rotary stand of the structure discussed above, when the electric appliance mounted on the mounting plate of the rotary stand is tilted or swung, the clamp plate then biased by the spring element rotate together with the mounting plate. Accordingly, the cylindrical boss integral with the pedestal, which extends through a center hole in the clamp plate to hold the clamp plate, has one end face susceptible to frictional wear, or obnoxious sounds tend to be generated between the spring element and the screw, resulting in the possibility that the spring comes to rotate with increase in frequency of use to eventually loosen the screw.  
           [0006]    The screw engaged in the cylindrical boss integral with the pedestal is normally biased by the spring element in a direction counter to the direction in which the screw is fastened into the cylindrical boss. Accordingly, repeated tilt and/or swing of the rotary stand or the use thereof in an environment rich of oil would result in cracking in the cylindrical boss or, if not at all, a detrimental fracture of the cylindrical boss.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention has been developed to overcome the above-described disadvantages.  
           [0008]    It is accordingly an objective of the present invention to provide a highly reliable, robust and simplified rotary stand wherein the functionality thereof is increased by allowing the display unit or the audio equipment to be oriented in any direction as desired, and wherein both the possibility of the obnoxious sounds generated between the spring used to bias the clamp plate and the screw and the possible loosening of the screw used to press the spring which would otherwise take place as the frequency of use increases are substantially eliminated to thereby avoid any possible cracking in or fracture of the boss integral with the pedestal.  
           [0009]    In accomplishing the above and other objectives, the present invention provides a rotary stand for the support thereon of a display unit or an audio equipment, which includes a pedestal having a spherically concave portion and a regulating projection formed in the spherically concave portion, a mounting plate having a bearing portion of a shape corresponding to the spherically concave portion and adapted to support thereon the display unit or the audio equipment, and a clamp plate having a shape similar to the bearing portion of the mounting plate for clamping the mounting plate between it and the pedestal while allowing the mounting plate to undergo a swinging motion leftwardly and rightwardly and also a tilting motion up and down. The bearing portion of the mounting plate has a slot defined therein, and the angle of any one of swing and tilt of the mounting plate is regulated by causing side edges of the regulating projection to engage corresponding inner side edges of the slot.  
           [0010]    According to the present invention, in view of the fact that the display unit or the audio equipment can be oriented in any desired direction within a predetermined angle of tilt and/or within a predetermined angle of swing, the functionality of the device can advantageously be increased.  
           [0011]    In one preferred embodiment, the slot referred to above has a pair of parallel long side edges and, when the side edges of the regulating projection are brought into engagement with the long side edges of the slot, the angle of swing in a leftward or rightward direction is limited, whereas when the side edges of the regulating projection are brought into engagement with inner edges of the slot other than the long side edges, the angle of tilt in an upward or downward direction is limited. This arrangement enables the functionality of the device to be increased with a simplified construction.  
           [0012]    Preferably, the regulating projection has approximately right-angled corners one on each end of a major axis thereof and also has side edges one on each end of a minor axis thereof. In this case, each of the side edges is curved to represent a generally arcuated shape, and the regulating projection has a width as measured in a direction along the minor axis thereof that is approximately equal to a width of the slot as defined between the long side edges of the slot. This arrangement also enables the functionality of the device to be increased with a simplified construction.  
           [0013]    In another preferred embodiment of the present invention, the spherically concave portion of the pedestal is formed with a rectangular projection and the clamp plate is formed with a generally rectangular opening defined therein. Opposite edge portions of the clamp plate that define opposite sides of the opening are bent downwardly to engage the rectangular projection to thereby allow the clamp plate to be retained relative to the pedestal. According to this embodiment, no members other than the mounting plate rotate even when the device is tilted and/or swung and, therefore, the highly reliable and robust rotary stand can be obtained in which the possibility is eliminated in which cracking or fracture may occur in the boss integral with the pedestal that is formed integrally with the regulating projection and the rectangular projection.  
           [0014]    In a further preferred embodiment of the present invention, a spring having a lower end fixed to the pedestal may be provided for biasing the clamp plate towards the bearing portion of the mounting plate. This spring does not rotate relative to the pedestal and, therefore, there is no possibility of obnoxious sounds being otherwise generated between the spring and the screw. Also, even if the frequency of use of the rotary stand increases, there is no possibility of the spring being loosened.  
           [0015]    The regulating projection and the rectangular projection may preferably have a common hole defined therein for passage of a screw therethrough with a free end thereof fastened by a nut to thereby connect the mounting plate, the clamp plate and the spring together with the pedestal. This arrangement is effective to avoid the possibility of cracking or fracture taking place in the boss even when the rotary stand is repeatedly swung and/or tilted and is used in an environment rich of oil. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    The above and other objectives and features of the present invention will become more apparent from the following description of a preferred embodiment thereof with reference to the accompanying drawings, throughout which like parts are designated by like reference numerals, and wherein:  
         [0017]    [0017]FIG. 1 is a perspective view of a personal MD system mounted on a rotary stand according to the present invention;  
         [0018]    [0018]FIG. 2A is a side view of the personal MD system, showing the range of tilt of such system relative to the rotary stand;  
         [0019]    [0019]FIG. 2B is a top plan view of the personal MD system, showing the range of swing of such system relative to the rotary stand;  
         [0020]    [0020]FIG. 3 is an exploded perspective view of the rotary stand according to the present invention;  
         [0021]    [0021]FIG. 4 is a perspective view showing a portion of a pedestal of the rotary stand shown in FIG. 3;  
         [0022]    [0022]FIG. 5 is a top plan view showing a relation between that portion of the pedestal and a mounting plate employed in the rotary stand;  
         [0023]    [0023]FIG. 6 is a perspective view, with a portion cut out, showing a relation between that portion of the pedestal and a clamp plate employed in the rotary stand;  
         [0024]    [0024]FIG. 7 is a perspective plan view of the clamp plate shown in FIG. 6 as viewed from below;  
         [0025]    [0025]FIG. 8 is a perspective view, with a portion cut out, showing a relation between that portion of the pedestal and other component parts  
         [0026]    [0026]FIG. 9 is a perspective view of a portion of the pedestal as viewed from below; and  
         [0027]    [0027]FIG. 10 is a top plan view of that portion of the pedestal shown in relation to the mounting plate, showing how the swing of the MD system is regulated. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0028]    This application is based on an application No. 2001-263461 filed Aug. 31, 2001 in Japan, the content of which is herein expressly incorporated by reference in its entirety.  
         [0029]    Referring to FIG. 1, there is shown a personal MD system M mounted on a rotary stand S according to one embodiment of the present invention. The illustrated rotary stand S is used to support thereon the personal MD system M for tilting up and down through a predetermined tilt angle, say, 15° upwardly and 5° downwardly as shown in FIG. 2A and also for swinging left and right as shown in FIG. 2B through a predetermined swing angle, say, 45° either leftwards or rightwards with respect to a neutral position as will be discussed later.  
         [0030]    As best shown in FIG. 3, the rotary stand S includes a pedestal  2  that is of a generally round shape so far shown, a mounting plate  4  that is of a generally rectangular shape so far shown, a clamp plate  6  disposed above the mounting plate  4  and adapted to movably clamp the mounting plate  4  in cooperation with the pedestal  2 , a screw  12  and a nut  14  for connecting the mounting plate  4 , the clamp plate  6  and the pedestal  2  together with a coiled spring  8  and a washer  10  interposed between a head of the screw  12  and the clamp plate  6 . The pedestal  2  and the mounting plate  4  are preferably made of a plastic material whereas the clamp plate  6  is preferably made of either a plastic material or a metallic material.  
         [0031]    Referring to FIG. 4, the pedestal  2  has a geometrical center defined therein and spaced an equal distance radially inwardly from the perimeter of the pedestal  2  and is formed with a round rim  16  concentric with the geometrical center thereof. A center portion of the pedestal  2  inside the round rim  16  is downwardly, as viewed in FIG. 3, depressed to define a spherically concave portion  18  in alignment with the geometric center of the pedestal  2 . A regulating projection  20  is formed integrally with the pedestal  2  so as to occupy a position at the bottom of the spherically concave portion  18  in alignment with the geometric center of the pedestal  2 . Mounted atop the regulating projection  20  is a substantially rectangular projection  22  formed integrally with the regulating projection  20 , the function of which will be described later. A hollow cylindrical projection  24  is in turn formed integrally with the rectangular projection  22  so as to protrude upwardly therefrom in alignment with the geometric center of the pedestal  2 .  
         [0032]    It is to be noted that the regulating projection  20  is of a generally rhombic shape defined by equally partially removing opposite two of the four right-angled corners of the square shape to define respective rounded side edge while the remaining two opposite corners are left right-angled. Thus, the regulating projection  20  of the particular shape discussed above has a geometric major axis, representing the length of the regulating projection  20 , and a geometric minor axis representing the width of the regulating projection  20 . It is to be noted that the pedestal  2  may be of one-piece construction including the projections  20 ,  22  and  24  and this can readily be accomplished by the use of any known plastic molding technique.  
         [0033]    The coiled spring  8  has upper and lower ends as viewed in FIG. 4 and is mounted around the cylindrical projection  24 . The lower end of the coiled spring  8  is bent at  8   a  to extend axially and is, when the coiled spring  8  is mounted around the cylindrical projection  24 , inserted into a round hole  20   c  that is defined adjacent one  20   a  of the right-angled corners of the regulating projection  20 .  
         [0034]    As best shown in FIGS. 3 and 5, the mounting plate  4  is mounted on the pedestal  2  for rotation and tilting relative to the pedestal  2  and has a semispherical bearing portion  26  formed integrally therewith. This bearing portion  26  has its undersurface defining a spherically convex portion generally complementary in shape to the spherically concave portion  18  in the pedestal  2  so that the mounting plate  4  can rotate and tilt relative to the pedestal  2  with such spherically convex portion held in sliding contact with the spherical concave portion  18 . The bearing portion  26  also has its upper surface defining a spherically concave portion  28  corresponding to the spherically convex portion at the undersurface of the bearing portion  26 . It is to be noted that the spherically convex portion of the bearing portion  26  that will be received within the spherically concave portion  18  in the pedestal  2  has a radius of curvature selected to be smaller than that of the spherically concave portion  18  in the pedestal  2 . The spherical bearing portion  26  has a geometrically center portion formed with a rectangular slot  26   a  of a width equal to or substantially equal to the width of the regulating projection  20 .  
         [0035]    Referring to FIGS. 6 and 7, in a manner similar to the bearing portion  26  integral with the mounting plate  4 , the clamp plate  6  is formed with a spherically concave portion  30  having its undersurface defining a spherically convex portion that is slidably engageable with the spherically concave portion  28  of the bearing portion  26  in the mounting plate  4 . This clamp plate  6  has a geometrically center portion formed with a generally rectangular opening  6   a . As best shown in FIG. 7, opposite two of the four side lip regions of the opening  6   a  are bent to protrude downwardly as viewed in FIG. 3 to thereby define engagements  32 . These engagements  32  have an internal span so selected as to be approximately equal to the width (or the length) of the rectangular projection  22  integral with the pedestal  2  so that the engagements  32  can embrace the rectangular projection  22  to thereby allow the clamp plate  6  to cooperate with the pedestal  2  to clamp the bearing portion  26  of the mounting plate  4  therebetween. Thus, it will readily be seen that the mounting plate  4  is movably clamped between the clamp plate  6  and the pedestal  2  with the spherically concave portion  28  slidingly received within the spherically concave portion  18  and with the clamp plate  6  slidingly received within the spherically concave portion  28 .  
         [0036]    Considering that the bearing portion  26  of the mounting plate  4  does, while sandwiched between the pedestal  2  and the clamp plate  6 , undergo rotary and tilting motions relative to the pedestal  2 , the downwardly protruding wall of the bearing portion  26  has a wall thickness so selected that the engagements  32  formed on the undersurface of the clamp plate  6  will not collide with an upper surface of the regulating projection  20  integral with the pedestal  2 .  
         [0037]    As shown in FIG. 8, the clamp plate  6  has an upper surface held in engagement with the lowermost turn of the coiled spring  8  adjacent the axially extending end thereof that is inserted into the hole  20   c  in the regulating plate  20 . An upper end of the coiled spring  8  opposite to the axially extending lower end thereof is held in engagement with the washer  10  held in position by the head of the screw  12 . Accordingly, the clamp plate  6  is always urged downwardly towards the bearing portion  26  of the mounting plate  4  by a biasing force of the coiled spring  8 .  
         [0038]    As best shown in FIG. 9, an undersurface of the pedestal  2  is formed with a hollow cylindrical boss  34  that protrudes downwardly in alignment with the cylindrical projection  24  protruding upwardly as shown in FIG. 3. Respective hollows in the cylindrical projection  24  and the cylindrical boss  34  altogether define a screw hole  36  through which the screw  12  referred to hereinbefore extends. A lower end of the cylindrical boss  34  has a hexagonal recess  38  defined therein in alignment with the screw hole  36  for accommodating the nut  14  that is fastened to a lower end of the screw  12 . Thus, the clamp plate  6 , the mounting plate  4  and the pedestal  2  are united together by the screw  12  with the nut  14  fastened thereto.  
         [0039]    In the rotary stand S of the above described structure, the bearing portion  26  of the mounting plate  4  is sandwiched between the spherically concave portion  18  of the pedestal  2  and the clamp plate  6  and is normally urged by the spring  8  towards the pedestal  2  through the clamp plate  6 .  
         [0040]    Referring particularly to FIG. 5 showing the mounting plate  4  as viewed from top, the mounting plate  4  has a plurality of retainers  40  for retaining the personal MD system M in position on the mounting plate  4 , a plurality of stoppers  42  engageable with a rear portion of the body of the system M and a lock  44  for locking the body of the system M then retained on the mounting plate  4 . The personal MD system M can be detachably mounted on the mounting plate  4  and can be locked in a retained position once it has been mounted on the mounting plate  4 .  
         [0041]    The rectangular slot  26   a  defined in the mounting plate  4  has its length lying in a direction forwardly and rearwardly and, with the mounting plate  4  so clamped between the clamp plate  6  and the pedestal  2 , the regulating projection  20  integral with the pedestal  2  is accommodated within the rectangular slot  26   a  with its major axis lying parallel to the lengthwise direction of the rectangular slot  26   a  when the personal MD system M mounted on the mounting plate  4  is held at the neutral position. Thus, the opposite rounded side edges of the regulating projection  20  are held in face to face relation with associated long side edges of the rectangular slot  26   a . However, when the personal MD system M on the mounting plate  4  is swung 45° either leftwards or rightwards, as shown in FIG. 2B, from the neutral position about the screw  12 , the right-angled corners of the regulating projection  20  are brought into abutment with the associated long side edges of the rectangular slot  26   a . Similarly, when the personal MD system M on the mounting plate  4  is tilted either 15° upwardly or 5° downwardly as shown in FIG. 2A from the neutral position, one of the opposite right-angled corners of the regulating projection  20  is brought into engagement with one of opposite short side edges of the rectangular slot  26   a.    
         [0042]    More specifically, when the personal MD system M mounted on the rotary stand S of the present invention is desired to be swung leftwards or rightwards, an user has to apply a pushing force to the personal MD system M to turn the latter leftwards or rightwards about the screw  12  together with the mounting plate  4  on which the personal MD system M rests. At this time, as the mounting plate  4  is so turned, the bearing portion  26  integrally formed therewith slidingly rotates while sandwiched between the spherically depressed wall  18  of the pedestal  2  and the clamp plate  6 . Turn of the personal MD system M either leftwards or rightwards from the neutral position continues so long as the user applies the appropriate pushing force to the personal MD system M and the latter can be held standstill once application of the pushing force is interrupted.  
         [0043]    As hereinabove described, the angle of tilt of the personal MD system M can be delimited by engagement of one of the right-angled corners of the regulating projection  20  with one of the short side edges of the rectangular slot  26   a  defined in the bearing portion  26  of the mounting plate  4 .  
         [0044]    On the other hand, the angle of swing of the personal MD system M about the screw  12  can be delimited by engagement of the right-angled corners of the regulating projection  20  with the respective long side edge of the rectangular slot  26   a  as shown by the phantom lines in FIG. 10. This is possible because the rectangular slot  26   a  has a width approximately equal to the width of the regulating projection  20 , but smaller than the length of the regulating projection  20  as clearly shown in FIG. 10.  
         [0045]    It is to be noted that although the rectangular slot  26   a  has been defined in the mounting plate  4 , each of the opposite short side edges of the rectangular slot  26   a  may not be always straight, but may be outwardly curved. In other words, a generally oval slot may be employed in place of the rectangular slot  26   a , provided that such slot has a pair of straight side edges.  
         [0046]    Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted here that various changes and modifications will be apparent to those skilled in the art. Therefore, unless such changes and modifications otherwise depart from the spirit and scope of the present invention, they should be construed as being included therein.