Abstract:
The present invention relates to a spill resistant keyboard including at least one conduit to permit a spilled liquid to drain through the keyboard without damaging the keyboard&#39;s electronics. The conduit is positioned along a sloped surface located along a front edge of a recessed area of the keyboard to promote the drainage of the spilled liquid through the conduit. The keyboard also includes water protection walls positioned around certain elongated keys prevent the spilled liquid from entering the body of the keyboard.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is generally directed to a keyboard and more particularly to a spill resistant keyboard. 
     2. Description of the Prior Art 
     Keyboard assemblies having a waterproof effect are well known in the prior art. Typically, these prior art designs incorporate one or more passages in the body of the keyboard that permit a spilled liquid to drain out through the keyboard without damaging the electronic components contained therein. However, these prior art designs are sometimes ineffective since water or other liquid which may spill on a keyboard may collect along the edges of the keyboard without necessarily exiting through the provided water passages. 
     These prior art designs also fail to recognize that in a typical keyboard used with a personal computer certain elongated keys (e.g., backspace key, shift key, enter key) are mounted to the body of the keyboard assembly by means of an equalizing wire which is anchored into the keyboard body within certain holes or bores provided in the keyboard body adjacent the elongated key. These holes in the keyboard body inadvertently provide a passage through which a spilled liquid may drain into the interior of the keyboard thereby damaging the sensitive electronic components housed therein. 
     Thus a need continues to exist for a spill resistant keyboard which ensures that a spilled liquid is completely drained from the keyboard without damaging the keyboard. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the invention to provide a keyboard which includes one or more drain passages which extend through the body of a keyboard for allowing a spilled liquid to drain from the keyboard without causing damage to any of the electronic components of the keyboard. 
     It is a further object of the invention to configure the keyboard to promote the flow of a liquid spilled on the keyboard body through the water passages. 
     It is still a further object to provide water protection walls which prevent water from entering the body of the keyboard through holes provided in the body of the keyboard to support the elongated keys. 
     In accordance with one aspect of the invention, there is provided a spill resistant keyboard which comprises a top enclosure and bottom enclosure joined together to define a keyboard housing. The top enclosure includes at least one recessed area having a bottom support wall which includes a plurality of key cap housings adapted to receive and slidably mount a plurality of key caps. The key cap housings include an upstanding wall extending upwardly from the bottom support wall and define therein a first barrier to a spilled liquid. The bottom support wall further includes a leading edge which defines at least one sloped or pitched surface with respect to the bottom support wall to promote the drainage of a spilled liquid. At least one conduit is positioned along the sloped or pitched surface of the leading edge and extends from the pitched surface to the bottom enclosure. The bottom enclosure include at least one hole or bore for mating with at least a portion of the at least one conduit thereby allowing any spilled liquids to drain through the keyboard housing through the at least one conduit without damaging any electronic components. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects, features and advantages of the invention, its construction and operation will be best understood from the following detailed description, taken in conjunction with the accompanying drawings, of which: 
     FIG. 1 is top plan view of a keyboard without the key caps; 
     FIG. 2 is cross sectional view taken along the line  2 — 2 ; 
     FIG. 3 is a top view of a key cap housing with water protection walls in accordance with a second aspect of the invention. 
     FIG. 4 is a detailed view of a portion of the key cap housing and water protection walls of FIG. 3; 
     FIG. 5 is a side view of a key cap slidably mounted to a keycap housing; and 
     FIG. 6 is a cross-sectional view of an elongated key mounted to a key cap housing taken along the line  6 — 6 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, a spill resistant keyboard in accordance with a preferred embodiment of the present invention is disclosed in FIGS. 1 through 3. As shown in FIGS. 1 and 2, the keyboard  10  is comprised of a keyboard housing  14  having a top enclosure  16  and a bottom enclosure  20 . In the space between the top and bottom enclosures  16 ,  20  of the keyboard housing  14  are located the electronic components (not shown) of the keyboard  10 . This area also includes a membrane  22  having a plurality of switch domes which resiliently support the key caps  72 . For crgonomic reasons, the top enclosure  16  of keyboard housing  14  is preferably disposed at a downward incline with respect to the supporting surface on which the keyboard  10  is placed. As a result, a spilled liquid will drain from the top edge toward the front edge of the keyboard  10 . 
     The top enclosure  16  of keyboard housing  14  includes a plurality of recessed areas  24 . Each recessed area has a bottom supporting wall  26  which supports a plurality of key cap housings  28 . The bottom supporting wall  26  is also downwardly inclined. The key cap housings  28  may be integral with the bottom support wall  26  or may be separately mounted thereto. Whether integral with the bottom support wall or mounted thereto, the key switch housings  28  should form a first barrier to spill liquids. Specifically, each key cap housing  28  includes an upstanding wall  30  (or walls) which extends upwardly from the bottom support wall  26  initially preventing any spilled liquid from entering the interior of the keyboard housing where the sensitive electronics are housed. Each key switch housing  28  includes a center opening  32  defined by the upstanding wall  30  into which is slidably mounted a key cap  72 , as is well known in the art. The key caps  72 , for example, are arranged using the well know QWERTY key configuration. 
     As shown in FIG. 2, each recessed area  24  includes one or more passages or conduits  40  which extend downwardly from the bottom support wall  26  toward the bottom enclosure  20 . The bottom enclosure  20  includes one or more openings or holes  44  which are positioned along a bottom wall of the bottom enclosure  20  to correspond with each one or more conduits  40 . Each hole  44  receives at least a portion of a corresponding conduit  40 . In a preferred embodiment, the holes or bores  44  are circumscribed by an upstanding wall or collar  46  which tightly receives the leading edge of the conduit  40  to further ensure that a spilled liquid will drain through the conduit and out through the bore  44  in the direction of the arrows shown in FIG. 2 onto the surface which supports the keyboard  10 . Alternatively, the conduits  40  may be formed in the bottom enclosure and extend upwardly to be similarly received in openings formed in the top enclosure  16 . 
     Since the top enclosure  16  and the bottom wall  26  are preferably inclined toward the front edge of the keyboard  10 , a spilled liquid runs off in the direction of the front edge of the keyboard  10 . Accordingly, the conduits  40  are disposed along the front edge of each of the recessed areas  24 . To further promote drainage of spilled liquid, at least a portion of the front edge of each of the recessed areas includes at least a second sloped surface  50  with respect to the sloped bottom support wall  26 . The second sloped surface  50  may be inclined either in the same direction as the incline of the bottom support wall  26  or transverse thereto as shown in FIG.  2 . The conduits  40  are preferably located in the front edge of the recessed area  24  and along the second sloped surface  50  to promote the drainage of spilled liquids and obviate the collection of the liquids within the recessed areas  24 . As shown in FIG. 2, in the preferred embodiment the conduits  40  are disposed between pairs of sloped surfaces  50 ,  52  forming a series of V-shaped valleys. The outermost V-shaped valleys  54 ,  56  ensure that spilled liquids run off the top enclosure  16  and do not collect or pool along the edges of the recesses  24 . 
     In a further aspect of the invention, water protection walls  60 , are configured on the bottom support wall  26  of each of the recesses  24  which includes an elongated key  74  (e.g., backspace key, shift key, enter key) (not shown). As is known in the art, elongated keys  74  are supported by the use of an equalizing wire  76 , not shown, which is anchored to the bottom support wall by means of one or more holes  66  which are provided in the bottom support wall. A top wall  68  which extends over the holes  66  is also provided to help anchor the equalizing wire to the bottom support wall  26 . Other similar means are known for securing the equalizing wire  76  to the keyboard. The equalizing wire  76  improves the feel of thee elongated keys  74 , particularly, around their corners when depressed by a user. 
     The holes  66  used to anchor the equalizing wire  76  provide an unintended passage for spilled liquids to drain into the keyboard housing thereby damaging the sensitive electronic components contained therein. As shown in FIGS. 3 and 4, the water protection walls  60  extend upwardly from the bottom support wall  26  and surround the holes  66  on opposite sides of the key cap housing  28  to prevent liquids from entering into the keyboard housing  14 . Preferably, at least one welter protection wall segment  60   a  abuts the key cap housing  28 , as shown if FIG.  4 . However, alternatively, water protection wall  60   a  may be omitted and the external wall  70  of the key cap housing  28  may be used as a water protection wall  60 . In such a configuration, the ends of water protection wall segments  60   b  and  60   c  are directly connected to external wall  70  of key cap housing  28 . The water protection walls  60  should be as high as possible without touching the key cap after if has been depressed. 
     Now that the preferred embodiments of the present invention have been shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is to be construed broadly and limited only by the appended claims, and not by the foregoing specification.