Patent Publication Number: US-6904685-B1

Title: Pivotal device for scissors

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a pivotal device for a pair of scissors. 
     2. Description of the Related Art 
       FIGS. 5 and 6  of the drawings illustrate a pair of conventional scissors including a scissor element  1  and a second scissor element  2 . The first scissor element  1  and the second scissor element  2  are pivotally connected by a pivotal device consisting of a bolt or screw  4  and a nut  6 . As illustrated in  FIG. 6 , the first scissor element  1  includes a through-hole  7  extending from a side of the first scissor element  1  through the other side of the first scissor element  1 . Further, the second scissor element  2  includes a countersink  8  extending from a side of the second scissor element  2  through the other side of the second scissor element  2 . The countersink  8  includes a relatively smaller section  8   b  aligned with the through-hole  7  of the first scissor element  1  and a relatively larger section  8   a.    
     The screw  4  has a threaded shank  5  extending through the relatively smaller section  8   b  of the countersink  8  and the through-hole  7  of the first scissor element  1  and then engaged with a screw hole ( 3 ) of the nut  6 , with an enlarged head  4   a  of the screw  4  being fittingly received in the relatively larger section  8   a  of the countersink  8 . 
     Nevertheless, the pivotal arrangement is apt to be loosened, as the screw  4  directly contacts with and thus might move together with the first scissor element  1  and the second scissor element  2  that pivot relative to each other during use of the pair of scissors. Further, the exposed nut  6  may interfere with operation of the pair of scissors. 
     SUMMARY OF THE INVENTION 
     In accordance with an aspect of the invention, a pair of scissors in accordance with the present invention includes a first scissor element, a second scissor element, and a pivotal device for pivotally engaging the first scissor element with the second scissor element. The first scissor element includes a countersink extending from a first side of the first scissor element through a second side of the first scissor element. The countersink of the first scissor element has a relatively larger section facing away from the second scissor element and a relatively smaller section facing the second scissor element. 
     The second scissor element includes a countersink extending from a first side of the second scissor element through a second side of the second scissor element. The countersink of the second scissor element has a relatively larger section facing away from the first scissor element and a relatively smaller section facing the first scissor element and aligned with the relatively smaller section of the countersink of the first scissor element. 
     The pivotal device includes a screw and a nut. The screw includes a threaded shank and an enlarged head. The nut includes a shank and an enlarged head, with a screw hole extending through the shank and the enlarged head of the nut. 
     The nut is received in the countersink of the first scissor element, with the enlarged head of the nut being received in the relatively larger section of the countersink of the first scissor element, and with the shank extending through the relatively smaller section of the countersink of the first scissor element and the relatively smaller section of the countersink of the second scissor element. 
     The threaded shank of the screw is threadedly engaged with the screw hole of the nut, with the enlarged head of the screw being received in the relatively larger section of the countersink of the second scissor element. 
     Thus, the contact area between the screw and the pivotable scissor elements is relatively small as compared to the conventional designs. Thus, the screw is less likely to move when the scissor elements pivot. The risk of loosening of the screw and/or the nut is reduced. A reliable pivotal arrangement is provided accordingly. 
     Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a pair of scissors in accordance with the present invention. 
         FIG. 2  is an exploded perspective view of the pair of scissors in accordance with the present invention. 
         FIG. 3  is an enlarged exploded perspective view of a pivotal device of the pair of scissors in accordance with the present invention. 
         FIG. 4  is a sectional view illustrating pivotal arrangement of the pair of scissors in accordance with the present invention. 
         FIG. 5  is a perspective view of a pair of conventional scissors. 
         FIG. 6  is a sectional view illustrating pivotal arrangement of the pair of conventional scissors. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 through 4 , a pair of scissors  1  in accordance with the present invention comprises a first scissor element  11 , a second scissor element  12 , and a pivotal device for pivotally engaging the first scissor element  11  with the second scissor element  12 . 
     As illustrated in  FIG. 4 , the first scissor element  11  includes a countersink  13  extending from a first side of the first scissor element  11  through a second side of the first scissor element  11 . The countersink  13  of the first scissor element  11  has a relatively larger section  13   a  facing away from the second scissor element  12  and a relatively smaller section  13   b  facing the second scissor element  12 . 
     Similarly, the second scissor element  12  includes a countersink  14  extending from a first side of the second scissor element  12  through a second side of the second scissor element  12 . The countersink  14  of the second scissor element  12  has a relatively larger section  14   a  facing away from the first scissor element  11  and a relatively smaller section  14   b  facing the first scissor element  11  and aligned with the relatively smaller section  13   b  of the countersink  13  of the first scissor element  11 . 
     The pivotal device includes a bolt or screw  17  and a nut  15 . The screw  17  includes a threaded shank  18  (having an outer threading) and an enlarged head  17   a . The nut  15  includes a shank  15   a  and an enlarged head  15   b , with a screw hole  16  extending through the shank  15   a  and the enlarged head  15   b.    
     In assembly, as illustrated in  FIG. 4 , the nut  15  is inserted into the countersink  13  of the first scissor element  11 , with the enlarged head  15   b  being fittingly received in the relatively larger section  13   a  of the countersink  13 , and with the shank  15   a  extending through the relatively smaller section  13   b  of the countersink  13  of the first scissor element  1  and the relatively smaller section  14   b  of the countersink  14  of the second scissor element  12 . Next, the threaded shank  18  of the screw  17  is threadedly engaged with the screw hole  16  of the nut  15  until the enlarged head  17   a  of the screw  17  is fittingly received in the relatively larger section  14   a  of the countersink  14  of the second scissor element  12 . The enlarged head  17   a  of the screw  17  includes a slot  20 , allowing the user to drive the screw  17  with a screwdriver or the like. 
     As can be seen from  FIG. 4 , the screw  17  is not in contact with the first scissor element  11 , and the screw  17  is in contact with the second scissor element  12  at the enlarged head  17   a . Thus, the contact area between the screw  17  and the pivotable scissor elements  11  and  12  is relatively small as compared to the conventional designs. Thus, the screw  17  is less likely to pivot when the scissor elements  11  and  12  pivot. The risk of loosening of the screw  17  and/or the nut  15  is reduced. A reliable pivotal arrangement is provided accordingly. 
     Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the invention as hereinafter claimed.