Abstract:
The present invention provides a scanner including a housing defining two mounting holes. An elastic rib is located beside each of the two mounting holes to provide a retaining action. A paper cover is pivotally mounted on the housing and has two locking hooks. Each locking hook is mounted in a respective mounting hole of the housing. Thus, the height of the paper cover can be adjusted according to the variation of depth of the locking hook in the mounting hole. In addition, the locking hook is retained by the elastic rib and the catch plate of the mounting hole, such that the paper cover cannot be removed easily, thereby preventing the paper cover from being lost.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a scanner capable of adjusting the height of a paper cover, and more particularly to a scanner that can adjust the height of the paper cover automatically according to the thickness of papers to be scanned, and can prevent the paper cover from being detached and lost.  
           [0003]    2. Description of the Related Art  
           [0004]    In general, a scanner includes a housing pivoted with a pivotable cover to cover the papers to be scanned during the scanning process. However, the cover is pivoted in a fixed manner. Therefore, if the papers to be scanned have a greater thickness, or when the book is scanned, the cover cannot smoothly cover the object to be scanned.  
           [0005]    The closest prior art of which the applicant is aware is disclosed in U.S. Pat. No. 5,812,285 which discloses a scanner capable of adjusting the height of a paper cover automatically. The paper cover is mounted with a horizontal shaft, and the body of the scanner defines a shaft cavity receiving the horizontal shaft. Thus, when the paper cover is used to cover the papers to be scanned having a greater thickness, the height of the paper cover can be adjusted such that the paper cover can smoothly cover the papers.  
           [0006]    However, there is no proper retaining design between the horizontal shaft and the shaft cavity. Thus, although the horizontal shaft can be assembled in the shaft cavity easily, the horizontal shaft can also be detached from the shaft cavity easily, so that the paper cover is easily lost. In addition, two opposite support arms are mounted between the horizontal shaft and the paper cover. Each of the support arms has a plate shape, so that the structural strength thereof is not sufficient. Thus, when the user open the paper cover very quickly or open the paper cover with an excessively large force, the support arm is easily broken, thereby affecting the quality of the product.  
           [0007]    The primary objective of the present invention is to provide a scanner, wherein when the paper cover is assembled with the housing of the scanner, the paper cover is retained by a retaining element, thereby preventing the paper cover from detaching from the housing of the scanner.  
           [0008]    For achieving the above-mentioned objective, the paper cover is protruded with two locking hooks, and the housing of the scanner defines two mounting holes. An elastic rib is located beside each of the two mounting holes to provide a retaining action. Thus, each of the locking hooks is mounted in a respective mounting hole, and is prevented from detachment by the elastic rib.  
           [0009]    The locking hook includes a shank having two sides each protruded with a wing block, thereby forming a substantially I-shaped structure which has an enhanced structural strength. Thus, when the paper cover is pivoted and opened with an excessive angle, the locking hook cannot be broken easily.  
           [0010]    Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is an exploded perspective view of a scanner capable of adjusting the height of a paper cover in accordance with the present invention;  
         [0012]    [0012]FIG. 2 is a locally enlarged view of the scanner capable of adjusting the height of a paper cover as shown in FIG. 1;  
         [0013]    [0013]FIG. 3 is a side plan cross-sectional assembly view of the scanner capable of adjusting the height of a paper cover as shown in FIG. 2;  
         [0014]    [0014]FIG. 4 is a schematic assembly view, wherein the paper cover in accordance with the present invention is disposed at a covering state;  
         [0015]    [0015]FIG. 5 is a schematic operational view of the scanner as shown in FIG. 4, wherein the paper cover is disposed at an opened state;  
         [0016]    [0016]FIG. 6 is a schematic operational view of the scanner as shown in FIG. 4, wherein the paper cover is disposed at a lifted state;  
         [0017]    [0017]FIG. 7 is a schematic operational view of the scanner from another direction as shown in FIG. 4, wherein the paper cover is disposed at a lifted state; and  
         [0018]    [0018]FIG. 8 is an assembled schematic view of the mounting hole and the locking hook of the scanner in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    Referring to the drawings and initially to FIGS. 1 and 2, a scanner in accordance with the present invention comprises a housing  11  having an upper surface  12  having one end  13  defining two mounting holes  14 . The top edge of each of the two mounting holes  14  is mounted with two opposite catch plates  17  and  18  located adjacent to the end face  19  of the housing  11  of the scanner. Thus, the mounting hole  14  is substantially T-shaped.  
         [0020]    Referring to FIGS. 2 and 8, the transverse width of the transverse portion  15  of the mounting hole  14  is defined as A, and the longitudinal length of the transverse portion  15  of the mounting hole  14  is defined as B. The longitudinal portion  16  formed by the distance between the two opposite catch plates  17  and  18  has a transverse width defined as C, and a longitudinal length defined as D. The transverse width C of the longitudinal portion  16  is smaller than the transverse width A of the transverse portion  15  apparently.  
         [0021]    In addition, an opened type opening  21  is defined in the connection of the distal end of the longitudinal portion  16  of the mounting hole  14  and the end face  19  of the housing  11  of the scanner. The transverse width of the opening  21  is equal to the distance between the two opposite catch plates  17  and  18 .  
         [0022]    The elastic rib  31  consists of a rib body  32  whose top end is formed with a catch block  33 . The elastic rib  31  that has an elastic movement ability is mounted on one side of the transverse portion  15  of each of the two mounting holes  14 . The catch block  33  has one side  34  extended into the transverse portion  15  of the mounting hole  14 .  
         [0023]    Referring to FIGS. 1 and 2, two locking hooks  44  are mounted on the inner face  42  of the paper cover  41  located adjacent to the end portion  43 . Each of the locking hooks  44  includes a shank  45  having a first side  46  protruded with a wing block  48 , and a second side  47  protruded with a wing block  49 , thereby forming an I-shaped structure. The surface of the shank  45  defines an opening  51 .  
         [0024]    Referring to FIGS. 2 and 8, the transverse distance between the two wing blocks  48  and  49  is defined as E which is slightly smaller than the transverse width A of the transverse portion  15  of the mounting hole  14 . Each of the two wing blocks  48  and  49  has a length (transverse direction) defined as X, and a width (longitudinal direction) defined as Y. X may be equal to Y The width Y is slightly smaller than the longitudinal length B of the transverse portion  15  of the mounting hole  14 .  
         [0025]    In addition, the width of the shank  45  is defined as F. The width F is slightly smaller than transverse width C of the longitudinal portion  16  of the mounting hole  14 . The length between each of the two wing blocks  48  and  49  and the end edge  52  of the opening  51  is defined as G. The length G is approximately equal to the sum of the longitudinal length B of the transverse portion  15  of the mounting hole  14  and the longitudinal length D of the longitudinal portion  16 . Namely, G=B+D.  
         [0026]    Referring to FIGS. 1, 3 and  8 , when the paper cover  41  is assembled, the paper cover  41  is initially disposed in an upright manner, so that the locking hook  44  is disposed in a horizontal manner to align with the mounting hole  14 . Because the transverse distance E between the two wing blocks  48  and  49  is slightly smaller than the transverse width A of the transverse portion  15  of the mounting hole  14 , the locking hook  44  can enter the mounting hole  14  through the transverse portion  15  of the mounting hole  14 .  
         [0027]    When the locking hook  44  enters the mounting hole  14 , one end of the shank  45  of the hook  44  will push the catch block  33  extended into the transverse portion  15 , with assistance of a tool if necessary, to swing the elastic rib  31  so that the side  34  of the catch block  33  leaves the transverse portion  15 . Thus, the shank  45  and the wing block  49  (the other wing block is not shown in the figure) completely and fluently enter the mounting hole  14 . The opening  51  of the shank  45  faces the opening  21  of the housing  11  of the scanner. When the elastic rib  31  returns to its original position, the catch block  33  is located above the shank  45 . Thus, if the user wants to remove the paper cover  41 , he has to exert an external force to push the elastic rib  31  with assistance of a tool if necessary, so as to detach the catch block  33  from the transverse portion  15  of the mounting hole  14 . Thus, the paper cover  41  cannot be removed easily, thereby preventing the paper cover  41  from being lost.  
         [0028]    If the paper cover  41  is displaced outward, the shank  45  of the locking hook  44  is not located under the catch block  33  of the elastic rib  31 . Because the width Y of each of the two wing blocks  48  and  49  is slightly smaller than the longitudinal length B of the transverse portion  15  of the mounting hole  14 , the locking hook  44  is limited by the catch plates  17  and  18 . Thus, the paper cover  41  cannot be moved upward to be removed, thereby efficiently preventing the paper cover  41  from detachment.  
         [0029]    Referring to FIG. 4, the paper cover  41  that has been assembled on the housing  11  of the scanner can be rotated, so that the locking hook  44  is disposed in a vertical manner. Thus, the paper cover  41  can cover the housing  11  of the scanner.  
         [0030]    Referring to FIG. 5, when the paper cover  41  is pivoted outward, one end edge  52  of the opening  51  of the shank  45  is rested on the end face  19  of the housing  11  of the scanner, so that the shank  45  is disposed in an oblique manner. The length G between the wing block  49  and the end edge  52  of the opening  51  is approximately equal to the sum of the longitudinal length B of the transverse portion  15  of the mounting hole  14  and the longitudinal length D of the longitudinal portion  16 , namely, G=B+D. Therefore, after the locking hook  44  is rotated, the wing block  49  (the other wing block is not shown in the figure) is displaced in a curved manner to abut the bottom edge of the catch plate  18 , so that the paper cover  41  will not fall outward.  
         [0031]    In the locking hook  44  of the paper cover  41 , the shank  45  and the wing blocks  48  and  49  form a substantially I-shaped structure which has a greater structural strength. Thus, when the paper cover  41  is pivoted and opened, the locking hook  44  cannot be broken easily.  
         [0032]    Referring to FIGS. 6 and 7, the paper cover  41  located at a horizontal state is displaced upward. The wing blocks  48  and  49  at the two sides of the shank  45  are respectively rested on the bottom face of the catch plates  17  and  18 . Thus, the paper cover  41  not only can adjust the covering height and horizontal degree according to the thickness of the papers to be scanned, but also will not detach from the housing  11  of the scanner due to displacement of the paper cover  41 .  
         [0033]    It is found from the above-mentioned description that, the present invention can adjust the height of the paper cover  41 , prevent the locking hook  44  on the paper cover  41  from being broken, and can prevent the paper cover  41  from being detached and lost.  
         [0034]    While the preferred embodiment of the present invention has been shown and described, it will be apparent to those skilled in the art that various modifications may be made in the embodiment without departing from the spirit of the present invention. Such modifications are all within the scope of the present invention.