Abstract:
An apparatus includes a wall defining an opening. A first bracket is connected to the wall and defines a first channel. A second bracket is located across the wall opening from the first bracket and defines a second channel. A hinge connects the second bracket to the wall such that the second bracket can pivot from a first position in which the second channel is open toward the wall opening to a second position in which the second channel is open toward the first channel. The brackets are configured to retain the lens in an installed position in which the lens extends across the wall opening, the first bracket captures a first end of the lens, the second bracket is in its second position, and the second channel captures a second end of the lens.

Description:
TECHNICAL FIELD 
   This application relates to welding shields. 
   BACKGROUND 
   During the process of welding, an intensely bright light and a shower of sparks is emitted from a part being welded. The welder&#39;s eyes can be shielded from the light and sparks by a welding shield. The welding shield includes a shield plate, with a dark tinted glass window, and a handle. Grasping the handle, the welder holds the shield plate up in front of his face while welding. This enables the welder to view the part being welded through the tinted glass while shielding his eyes from the light and sparks. 
   SUMMARY 
   An apparatus comprises a wall defining an opening. A first bracket is connected to the wall and defines a first channel. A second bracket is located across the wall opening from the first bracket and defines a second channel. A hinge connects the second bracket to the wall such that the second bracket can pivot from a first position in which the second channel is open toward the wall opening to a second position in which the second channel is open toward the first channel. The brackets are configured to retain the lens in an installed position in which the lens extends across the opening, the first bracket captures a first end of the lens, the second bracket is in its second position, and the second channel captures a second end of the lens. 
   Preferably, another hinge connects the first bracket to the wall such that the first bracket can pivot from a first position in which the first channel is open toward the wall opening to a second position in which the first channel is open toward the second channel. When the second bracket is in the second position, the hinge resiliently urges the second bracket back toward the first position. The second bracket has an engagement surface extending from the second channel opening in a direction away from the hinge, configured to be pushed by a finger to pivot the second bracket from the first position to the second position. 
   Also, preferably, the brackets enable the lens to be brought into the installed position by inserting the first end of the lens into the first channel and then pivoting the second end of the lens about the first channel toward and into the second channel. The second bracket has a smooth engagement surface extending from the second channel in a direction away from the hinge. The engagement surface is configured for the lens, while pivoting toward the second channel, to slide along the engagement surface toward the second channel with the engagement surface resiliently pressing the lens into the first channel. The sliding of the lens against the engagement surface toward the second channel increasingly flexes the engagement surface upward for the engagement surface to ride up and over the lens. The wall, the brackets and the hinge are molded as a one-piece structure. The apparatus is included as part of a welding shield. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a welding shield, including a lens mounted in a shield plate; 
       FIG. 2  is another perspective view of the shield, with the lens separated from the shield plate; 
       FIG. 3  is a sectional side view taken at line  3 — 3  of  FIG. 2 ; 
       FIG. 4  is an expanded front view of a section of  FIG. 3 ; 
       FIG. 5  is an expanded rear view of the section of  FIG. 3 ; 
       FIG. 6  is a sectional side view taken at line  6 — 6  of  FIG. 5 ; 
       FIGS. 7–10  are sectional side views similar to  FIG. 6 , showing the lens and the plate in sequential steps for installing the lens onto the plate; and 
       FIG. 11  is a sectional top view taken at line  11 — 11  of  FIG. 10 . 
   

   DESCRIPTION 
   The apparatus  1  shown in  FIG. 1  has parts that are examples of the elements recited in the claims. 
   The apparatus  1  is a handheld welding shield. It is used to shield a welder&#39;s eyes from sparks and intense light emitted from a part being welded. The shield  10  includes a shield plate  10 , a tinted lens  12  installed in the shield plate  10 , and a handle  14 . Grasping the handle  14 , the welder holds the shield plate  12  up in front of his face while welding. This enables the welder to view the part being welded through the lens  12  while shielding his eyes from the light and sparks. 
     FIG. 2  is an exploded view of the shield plate  10  and the lens  12 . The lens  12  is a piece of transparent material, preferably glass, that is darkly tinted to let only a portion of the light through. It has front and rear surfaces  22  and  24 . It further has a rectangular periphery defined by a top and bottom ends  32  and  34  and two opposite sides  36  and  38 . 
   As shown in  FIGS. 2 and 3 , the shield plate  10  is centered on perpendicular longitudinal and lateral axes  41  and  43 . The plate  10  includes a wall  40  with front and rear surfaces  46  and  48 . The wall  40  is pan-shaped, with the rear surface  48  defining a shield cavity  49 . The wall  40  has a rectangular periphery defined by laterally extending top and bottom edges  52  and  54  and two opposite longitudinally extending side edges  56  and  58 . The handle  14  projects longitudinally downward from the bottom edge  54  and is laterally centered between the side edges  56  and  58   
   As shown in  FIGS. 4 and 5 , the wall  40  has a rectangular opening  60  defined by top and bottom edges  62  and  64  of the wall  40  and two opposing side edges  66  and  68  of the wall  40 . 
   As shown in  FIG. 5 , the opening  60  is bracketed by a lip  70  that projects rearwardly from the rear surface  48  of the wall  40 . The lip  70  extends along the full lengths of the two side edges  66  and  68  and along portions of the upper and lower edges  62  and  64 . The lip  70  has a generally rectangular rear edge  72  that brackets the wall opening  60  and abuts the front face  22  of the lens  12  ( FIG. 2 ) when the lens  12  is installed on the shield plate  10 . 
   A lower bracket  80  extends laterally along, and is adjacent to, the bottom edge  64  of the wall opening  60 . The lower bracket  80  has a cross-sectional profile shown head-on in  FIG. 6 . This profile is uniform along the length of the bracket  80 . It is characterized by a laterally extending channel  81 . The channel  81  is bounded on three sides by first and second inner side surfaces  82  and  84  and an inner end surface  86  of the bracket  80 . The channel  81  is configured to closely receive the bottom  34  of the lens  12  when the lens  12  is mounted on the shield plate  10 . Accordingly, a width W L  of the bracket cavity  81 , which is the distance between the inner side surfaces  82  and  84 , equals, at least approximately, a thickness T ( FIG. 2 ) of the lens  12 . 
   First and second outer side surfaces  92  and  94  of the bracket  80  are respectively parallel to the first and second inner side surfaces  82  and  84 . First and second opposite outer end surfaces  96  and  98  extend from the first outer side surface  94  to the second outer side surface  94 . An opening  99  in the second outer end surface  98  provides access to the cavity  81 . 
   The lower bracket  80  and the bottom edge  64  of the wall opening  60  are connected together along their lengths by a hinge  110 . The hinge  110  extends laterally along an edge  112  of the bracket  80  where the first outer side surface  92  and the second outer end surface  98  meet. In this example, the hinge  10  is a living hinge, molded as a one-piece structure with the wall  40  and the lower bracket  80 . It bridges the bracket  80  and the shield wall  40  and is sufficiently thin and flexible to function as a hinge between them. As indicated by arrow  113 , the hinge  110  enables the lower bracket  80  to be pivoted away from its initial as-molded position shown in  FIG. 6 . Concurrently, the hinge  110  resiliently urges the lower bracket  80  back toward its initial as-molded position. The bracket  80  is flexible, but not as flexible as the living hinge  110 . 
   An upper bracket  120  extends laterally along, and is adjacent to, the top edge  62  of the wall opening  60 . The upper bracket  120  has a cross-sectional profile shown head-on in  FIG. 6 . As with the lower bracket  80 , the profile of the upper bracket  120  is characterized by a laterally extending channel  121 . The channel  121  is bounded on three sides by first and second opposite inner side surfaces  122  and  124  and an inner end surface  126  of the bracket  120 . The upper channel  121  is configured to closely receive the top  32  of the lens  12  ( FIG. 2 ) when the lens  12  is installed on the shield plate  10 . Accordingly, a width W U  of the upper channel  121 , which is the distance between the inner side surfaces  122  and  124 , equals, at least approximately, the thickness T ( FIG. 2 ) of the lens  12 . 
   The upper bracket  120  further has first and second outer side surfaces  132  and  134 . A first outer end surface  136  extends from the first outer side surface  132  to the second outer side surface  134 . A second outer end surface  138  extends from the first outer side surface  132  to a front opening  139  of the channel  120 . A third outer end surface  140  extends from the front opening  139 , in a direction away from the first outer side surface  132 , to the second outer side surface  134 . 
   The upper bracket  120  and the upper edge  62  of the wall opening  60  are connected together along their lengths by a hinge  150 . The hinge  150  extends laterally along an edge  152  of the bracket  120  where the first outer side surface  132  and the second outer end surface  138  meet. In this example, the hinge  150  is a living hinge molded as a one-piece structure with the wall  40  and the upper bracket  120 . It bridges the wall  40  and the upper bracket  120  and is sufficiently thin and flexible to function as a hinge between them. As indicated by arrow  153 , the hinge  150  enables the upper bracket  120  to be pivoted away from its initial as-molded position shown in  FIG. 6 . Concurrently, the hinge  150  resiliently urges the upper bracket  120  back toward its initial position. The upper bracket  120  is flexible, but not as flexible as the living hinge  150 . 
   The profile of the upper bracket  120  is not uniform along its length. As shown in  FIG. 4 , the second outer side surface  134  recedes toward the upper edge  62  with increasing proximity to the laterally opposite sides  160  of the upper bracket  120 . In fact, at the laterally opposite sides  160 , the entire second inner side surface  124  and a portion of the inner end surface  126  are absent. 
   As shown in  FIG. 5 , first and second upper retaining bosses  171  and  172  and first and second lower retaining bosses  173  and  174  extend rearwardly from the rear surface  48  of the wall  40 . The first bosses  171  and  173  are adjacent to the first edge  66  of the opening  60 . The second bosses  172  and  174  are adjacent to the second edge  68  of the opening  60 . Each boss  171 ,  172 ,  173  and  174  has an abutment surface  176  facing laterally inward. The abutment surfaces  176  are configured to abut the sides  36  and  38  ( FIG. 2 ) of the lens  12  when the lens  12  is in the installed position. 
   The shield plate  10  can be injection molded. The molding process entails 1) injecting heat-softened plastic resin between front and rear core faces of a mold (not shown), 2) waiting for the plastic to harden, 3) retracting the front and rear cores away from the shield plate, and 4) ejecting the shield plate from the mold. 
   The as-molded configuration of the shield plate  40  is shown in  FIG. 6 . In this configuration, the channels  80  and  120  are open toward the wall opening  60  in that the channel openings  99  and  139  face forward toward the wall opening  60 . This enables the front core of the mold to form the channels  81  and  121  along with features of the front surface  46 . After the plastic hardens, the front core can be withdrawn from the bracket channels  81  and  121  when being retracted from the front surface  46 . Accordingly, formation of the upper and lower channels  81  and  121  does not require additional cores, which would be the case if the channels  81  and  121  were open in a longitudinal or lateral direction. 
   The lens  12  ( FIG. 2 ) can be installed in the shield plate  12  as follows. First, as indicated by arrow  113 , the lower bracket  80  is pivoted about its hinge  110  rearward and downward from its initial, as-molded, position. This continues until the bracket  80  reaches a second position in which the lower channel  80  is open toward the upper channel  121 , i.e., the lower channel opening  99  faces the upper channel  121 , as shown in  FIG. 7 . Then the lens  12  is inserted into the lower channel  81 . 
   Next, the third outer end surface  140  is pushed rearward by a finger. As indicated by arrow  181 , this pivots the upper bracket  120  rearward about its living hinge  150  rearward and upward from its initial as-molded position. This continues until the bracket  120  reaches a second position in which the upper channel opening  139  faces the opposite channel  81 , as shown in  FIG. 8 , and the third outer end surface  140  is above the lens  12 . Concurrently, as indicated by arrow  183  in  FIG. 7 , the lens  12  is tilted rearward about the lower channel  81 . This continues until the third outer end surface  140  is above the lens  12 , as shown in  FIG. 8 . The tilting motions indicated by arrows  181  and  183  in  FIG. 7  are enabled, but resisted, by the flexibility of the brackets and hinges  80 ,  120 ,  110  and  150 . 
   Next, as indicated by the arrow  185  in  FIG. 8 , the lens  12  is pivoted forward toward the wall opening  60 . While pivoting increasingly forward, as indicated by arrow  187  in  FIG. 9 , the top  32  of the lens  12  slides against the third outer end surface  140  of the bracket  120 . In doing so, the lens  12  pushes the third outer end surface  140  increasingly higher as indicated by arrow  189 . Concurrently, the third outer end surface  140  resiliently bears down against the lens  12 , thus pressing it into the first channel  81 . 
   As the lens  12  continues forward (arrow  187 ), the third outer end surface  140  rides up (arrow  189 ) and over the lens  12 . The lens  12  thus finally snaps into its installed position, shown in  FIG. 10 . 
   The installed position is characterized by the following features: The first outer surfaces  92  and  132  of both brackets  80  and  120  abut the rear surface  48  of the wall  40 . The channel openings  99  and  139  face each other. A field of view is bounded longitudinally by the hinges  110  and  150  ( FIG. 5 ). The brackets  80  and  120 , including the second inner side surfaces  82  and  122  of the brackets  80  and  120 , do not cross into the field of view. The bracket channels  81  and  121  capture the lens  12 . Forward movement of the lens  12  is prevented by abutment of the front surface  22  of the lens  12  against both the rear edge  72  of the lip  70  and the first inner surfaces  82  and  122  of the brackets  80  and  120 . Rearward movement of the lens  10  is prevented by abutment of the rear surface  24  of the lens  12  against the second inner surfaces  84  and  124  of the brackets  80  and  120 . As shown in  FIGS. 11 , lateral movement of the lens  12  is limited, and prevented, by abutment of the sides  36  and  38  of the lens  12  against the abutment surfaces  176  of the retaining bosses  171 ,  172 ,  173  and  174  ( FIG. 5 ). 
   As is apparent in  FIG. 10 , the lens  12  can be removed from the shield plate  40  by pushing up on the third outer end surface  140  of the upper bracket  120  to release the lens  12 . The lens  12  can then be tilted rearward and lifted out of the lower bracket  80 . 
   This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.