Patent Publication Number: US-2009235420-A1

Title: Welding mask

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a welding mask, more particularly to a welding mask that can be assembled without damaging a lens thereof. 
     2. Description of the Related Art 
       FIG. 1  illustrates a conventional welding mask  1  that includes a mask body  11  and screen assembly  12 . The mask body  11  has a viewing window  110 . The screen assembly  12  serves to cover the viewing window  110 . In particular, the screen assembly  12  includes first and second frames  121 ,  122  and a lens  123 . The first frame  121  is mounted on the mask body  11 , and includes opposite top and bottom frame parts  124 ,  125 , each of which is formed with a protrusion  126 . The second frame  122  is connected detachably to the first frame  121 , and includes a flange  127  that extends radially and inwardly therefrom. The lens  123  is sandwiched between the protrusions  126  and the flange  127 . 
     The aforementioned conventional welding mask  1  is disadvantageous in that, during assembly, the lens  123  is easily damaged, i.e., scratched or broken, due to urging forces applied thereon by the protrusions  126  when the second frame  122  is connected to the first frame  121 , as best shown in  FIG. 2 . 
     SUMMARY OF THE INVENTION 
     Therefore, the object of the present invention is to provide a welding mask that can overcome the aforesaid drawback of the prior art. 
     According to the present invention, a welding mask comprises a mask body and a screen assembly. The mask body has a viewing window. The screen assembly serves to cover the viewing window, and includes first and second frames and a lens. The first frame is mounted on the mask body. The second frame is connected detachably to the first frame. The elastic piece is provided on the second frame. The lens is sandwiched between the elastic piece and the first frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which: 
         FIG. 1  is an exploded perspective view of a conventional welding mask; 
         FIG. 2  is a schematic sectional view of the conventional welding mask; 
         FIG. 3  is an exploded perspective view of the first preferred embodiment of a welding mask according to the present invention; 
         FIG. 4  is a sectional view of the first preferred embodiment; 
         FIG. 5  is an exploded perspective view illustrating a screen assembly of the second preferred embodiment of a welding mask according to this invention; and 
         FIG. 6  is a perspective view to illustrate a state where a second lens uncovers a lens of the second preferred embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Before the present invention is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure. 
     Referring to  FIG. 3 , the first preferred embodiment of a welding mask according to this invention is shown to include a mask body  2  and screen assembly  3 . 
     The welding mask of this invention protects the eyes of a welder from flying debris and an intense light generated during a welding operation, in a manner that will be described hereinafter. 
     The mask body  2  has a viewing window  21 . In this embodiment, the viewing window  21  may be sized in such a manner as to maximize a viewing angle or minimize the cost of the screen assembly  3 . 
     The screen assembly  3  serves to cover the viewing window  21 . In particular, the screen assembly  3  includes first and second frames  31 ,  33 , a lens  32 , and a pair of elastic pieces  34 . 
     The first frame  31  is mounted on the mask body  2 , and includes opposite top and bottom frame parts  311 ,  312  and opposite left and right frame parts  313 ,  314 , and a flange  315  that extends radially and inwardly therefrom. 
     The second frame  33  is connected detachably to the first frame  31 . In particular, each of the top and bottom frame parts  311 ,  312  of the first frame  31  is formed with a pair of engaging grooves  310 . The second frame  33  includes opposite top and bottom frame parts  331 ,  332  and opposite left and right frame parts  333 ,  334 . The top frame part  331  of the second frame  33  is formed with a pair of engaging protrusions  335 , each of which extends into a respective one of the engaging grooves  310  in the top frame part  311  of the first frame  31 . The bottom frame part  332  of the second frame  33  is formed with a pair of engaging protrusions  335 , each of which extends into a respective one of the engaging grooves  310  in the bottom frame part  312  of the first frame  31 . 
     Although the first and second frames  31 ,  33  of the screen assembly  3  of the welding mask of this invention are exemplified using two pairs of engaging grooves and two pairs of engaging protrusions, respectively, it should be apparent to those skilled in the art that the number of engaging grooves and engaging protrusions may be increased or decreased as required. 
     Each of the elastic pieces  34  is provided on a respective one of the top and bottom frame parts  331 ,  332  of the second frame  33 . In this embodiment, each of the elastic pieces  34  is in the form of a spring arm, and has opposite free end portions  341 , and a fixed portion  342  disposed between the free end portions  341  thereof and connected to a respective one of the top and bottom frame parts  331 ,  332  of the second frame  33 . 
     It is noted that the free end portions  341  of each of the elastic pieces  34  are spaced apart from the second frame  33  when the second frame  33  is detached from the first frame  31 . 
     The lens  32  has a generally rectangular shape, is surrounded by the top and bottom frame parts  311 ,  312  and the left and right frame parts  313 ,  314  of the first frame  31 , and is sandwiched between the free end portions  341  of the elastic pieces  34  and the flange  315  of the first frame  31 , as best shown in  FIG. 4 . In this embodiment, the lens  32  is an obscured lens. 
     Although the second frame  33  of the screen assembly  3  of this invention is exemplified using a pair of elastic pieces, it should be apparent to those skilled in the art that the number of elastic pieces may be increased or decreased as required. For example, the screen assembly  3  may further include another pair of elastic pieces that are provided on the left and right frame parts  333 ,  334  of the second frame  33 , respectively. 
     During assembly, the lens  32  is first disposed such that the lens  32  is surrounded by the top and bottom frame parts  311 ,  312  and left and right frame parts  313 ,  314  of the first frame  31  and abuts against the flange  315  of the first frame  31 . Then, the second frame  33  is disposed such that each of the elastic pieces  34  abuts against the lens  32 . Thereafter, the second frame  33  is connected to the first frame  31 . Each of the elastic pieces  34  absorbs an urging force applied on the lens  32  when the second frame  33  is connected to the first frame  31 . As a result, scratching or breaking of the lens  32  is prevented. 
     When it is desired to replace the lens  32 , the second frame  33  is first detached from the first frame  31  by simply deforming the second frame  33  such that each of the engaging protrusions  335  extends out of the respective one of the engaging grooves  310 . Once the lens  32  is replaced, the second frame  33  is connected back to the first frame  31 . 
       FIG. 5  illustrates the second preferred embodiment of a welding mask according to this invention. When compared to the previous embodiment, the screen assembly  3  further includes third and fourth frames  41 ,  43 , a second lens  42 , and a pair of second elastic pieces  44 . 
     The third frame  41  has a structure identical to the first frame  31  and is connected pivotably to the mask body  2 . 
     The fourth frame  43  has a structure identical to the second frame  33 , and is connected detachably to the third frame  41 . That is, each of engaging protrusions  445  of the fourth frame  43  extends into a respective one of engaging grooves  410  in the third frame  41 . 
     Each of the second elastic pieces  44  has a structure identical to the elastic pieces  34  and is provided on a respective one of top and bottom frame parts  431 ,  432  of the fourth frame  43 . That is, each of the elastic pieces  44  is in the form of a spring arm, and has opposite free end portions  441 , and a fixed portion  442  disposed between the free end portions  441  thereof and connected to a respective one of the top and bottom frame parts  431 ,  432  of the fourth frame  43 . 
     It is noted that the free end portions  441  of each of the elastic pieces  44  are spaced apart from the fourth frame  43  when the fourth frame  43  is detached from the third frame  41 . 
     The second lens  42  has a generally rectangular shape, is surrounded by top and bottom frame parts  411 ,  412  and the left and right frame parts  413 ,  414  of the third frame  41 , and is sandwiched between the free end portions  441  of the elastic pieces  44  and a flange  415  of the third frame  41 . 
     It is noted that, in this embodiment, the lens  32  is a transparent lens and the second lens  42  is an obscured lens. 
     The third frame  41  is pivotable relative to the mask body  2  between a first position, where the second lens  42  covers the lens  32 , and a second position, where the second lens  42  uncovers the lens  32 , as best shown in  FIG. 6 . 
     In use, during a welding operation, the third frame  41  may be disposed at the first position to thereby protect the eyes of the welder from an intense light generated during the welding operation. When not performing a welding operation, however, the third frame  41  may be disposed at the second position to give the welder a clearer view without having to remove or lift up the welding mask of this invention. 
     While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.