Abstract:
A bunk bed system including a head board and a foot board assembled with corner posts and interconnecting slats including a modified mortise and tenon joint which includes a dado on a lateral face of the tenon in alignment with a vertical post channel and longitudinal pin channel which lock and fixedly holding the joint together. The vertical channel member cooperatively engages the dado to both fixedly hold the tenon within the mortise and to also hold the tenon perpendicular to the mortise.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to the joining systems used to hold and secure a bunk bed frame together. 
       BACKGROUND OF THE INVENTION 
       [0002]    Beds usually contain a head board and a mattress which is supported by either a box spring or a flat spring unit. A box spring is a large mattress-sized box containing wood and springs that provide additional support and suspension for the mattress. In some beds, the box spring is supported by slats held by side rails which are connected to the headboard and a foot board. Other beds contain no foot board or side rails but instead have a self supporting metal frame which may be connected to a head board if desired. 
         [0003]    Still other beds, including most twin beds or bunk beds, contain a head board, a foot board, and a flat spring unit rather than a box spring. 
         [0004]    The head board and foot board commonly contain two wooden posts with horizontal slats connecting the posts together. Often the term “headboard” refers to both the headboard and footboard, since they are identical or similar in dimension Moreover the bunk beds can optionally be stacked one on tope of another for form bunk beds and save space. It is also common to mount the headboards on extenders so that the bed will be elevated providing space beneath the bed for desks, trunks, and the like. The wooden headboards are usually fabricated from two posts and at least one crosspiece extending between the posts by doweling and gluing or by mortise and tenon joints. It is not uncommon with heavy use such as in dorms for the joints to become loose after a period of time. 
         [0005]    The bed frames are usually fabricated from angle iron side rails and end rails welded together in a rectangle with one or more reenforcing members extending between the side rails. Springs and/or wires are typically strung between the rails to support a mattress thereon. The flat spring unit includes a peripheral frame and, typically, a support structure stretched inside the peripheral frame and supported by springs connecting the support structure to the rectangular peripheral frame. The support structure is often a wire mesh wherein wire members bent into links which cooperatively engage one another to form a two dimensional mattress supporting mesh. Other flat spring units may include springs stretched across a peripheral frame. A side rail mounting bracket is riveted or welded to each distal end of a side rail at each corner of the bed frame and adapted to include hooks which cooperatively engage and hang on pins which extend across the lateral face of a longitudinal U-shaped channel members disposed in a vertical channel or groove formed in each corner post of a headboard/footboard. 
       DESCRIPTION OF THE RELATED ART 
       [0006]    U.S. Pat. No. 110,632 for BED FASTENER by Comins issued on Jan. 3, 1871 teaches a metal plate including lugs on one end and a concave construction at the opposite end. The lugs cooperatively engage one end of a bed rail and securely hold the plate to the end of the bed rail. The concave end of the plate is pushed into a vertical slot of the bed post whereupon a dowel is pushed into an aperture capturing the concave end of the plate, forming a tight joint between the bed rail and the bed post. 
         [0007]    U.S. Pat. No. 3,948,198 for BED WITH UNITARY HEADBOARD AND UNITARY FRAME by Eldersveld issued on Sep. 27, 2005 teaches bed rails including two downward pointing hooks or lugs, one directly above the other which cooperatively engage two horizontal pins provided on one side of a bed post to securely fix the bed rail to the bed post. 
         [0008]    U.S. Pat. No. 7,796,367 for FURNITURE POST AND COUPLER by Ruiter et al. issued on Sep. 14, 2010 teaches a modular post including slots for insertion of vertical rails including horizontal pins which cooperatively engage hooks or lugs on mating furniture parts for the purpose of secure assembly. The post can be combined , end to end, with another identical post when using an interlocking coupler, resulting in a new post which is twice as tall as the first post. 
       SUMMARY OF THE INVENTION 
       [0009]    In accordance with the present invention, there is provided a bunk bed comprising, consisting of, and/or consisting essentially of a headboard and/or an opposing headboard/footboard, each one including a first post and a second post, the first post and the second post having at least two vertical sockets formed therein. At least one and preferably at least two horizontal slats each one having a tenon formed at each end for cooperative engagement with a corresponding vertical sockets within the first post and the second post capable of tightly receiving the tenons of the at least one and preferably at least two horizontal slats. The first post and the second post have vertical channels formed therein of a selected length aligned to face in a direction parallel to one another and in a direction perpendicular to the slats when the tenons of the slats are inserted into the first post and the second post. The sockets partially overlap a rear portion of the volume of the channels and extending into the posts a selected distance past the channels. The tenons have a vertical dado formed therein aligned with the channel when the tenons are fully inserted into the sockets. A generally U-shaped longitudinal pin channel having an elongated body is formed from a segment of extruded material is inserted into the vertical channel formed in the first post and the second post to cooperatively engage the dados within the tenons when the tenons are fully inserted into the sockets with the dados facing outwards into the vertical channels. The rear closed portion of the vertical pin channel members abut the dados and the open front portion or face of the pin channels have spaced apart horizontal pins extending between the side walls thereof capable of cooperatively engaging the vertical hooks extending from the end flanges of the bunk bed mattress supporting frame side rails. 
         [0010]    It is an object of this invention to provide a bed with a head board and a foot board including improved mortise and tenon joints 
         [0011]    It is an object of this invention to provide a bed with a head board and a foot board with mortise and tenon joints wherein the tenons include a dado in the side of the tenon facing into the bed and near the free end of the tenon. 
         [0012]    It is an object of this invention to provide a bed with a head board and a foot board wherein the dado near the end of the tenon receives a frame member which both fixedly holds the tenon within the mortise and forces the tenon to remain perpendicular within the mortise. 
         [0013]    It is an object of this invention to provide a bed with a head board and a foot board with the improved mortise and tenon joints described above which can utilize glue and/or screws to more securely fasten the mortise and tenon joint. 
         [0014]    Other objects, features, and advantages of the invention will be apparent with the following detailed description taken in conjunction with the accompanying drawings showing a preferred embodiment of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like numerals refer to like parts throughout the views wherein: 
           [0016]      FIG. 1  is a corner view of a bunk bed with bed posts including vertical post channels with the post interconnected by a plurality of slats with a pair of side rails connecting the head board and foot board and a springs strung between the side rails for supporting a mattress thereon; 
           [0017]      FIG. 2  is a perspective top view of a corner post showing placement of the slat tenon shoulder formed by the intersection of the distal end of the slat with the tenon for projection beyond the vertical post channel with a dado formed near the end of the tenon which aligns with and faces the vertical post channel which receives the pin channel retained by screws for locking engagement of the dado therein with the slat tenon shoulder abutting the surface of the corner post for holding the slat in position within respect to the post; 
           [0018]      FIG. 3  is a perspective top view of the of the corner post of  FIG. 2  showing the placement of the distal end of the head board slat including a tenon having a tenon end shoulder disposed within the slot projecting beyond the vertical post channel with a dado formed in the tenon near the distal end facing the vertical post channel and aligned with and in cooperative engagement with the vertical post channel and the pin channel retained within the vertical post channel by screws with the slat tenon shoulder abutting the surface of the corner post for locking the slat in position within the post and locking the tenon in the slat slot with the pin channel showing the distal end of the bed side rail and projecting hook in broken lines; 
           [0019]      FIG. 4  is a perspective view of the distal end of a slat showing the tenon end shoulder, dado formed within the tenon, and slat tenon shoulder; 
           [0020]      FIG. 5  is a perspective view of the distal end of a slat showing the tenon and tenon end shoulder; 
           [0021]      FIG. 6  is an exploded view showing a corner post having a interior slot and an exterior slot extending a selected distance beyond the vertical post channel terminating within the post, a slat showing placement of the slat tenon shoulder formed by the intersection of the distal end of the slat with the tenon for projection beyond the vertical post channel with a dado formed near the end of the tenon which aligns with and faces the vertical post channel which receives the pin channel retained by screws for locking engagement of the dado therein with the slat tenon shoulder abutting the surface of the corner post for holding the slat in position within respect to the post with the side rails and end flange having a hook shown in broken lines; 
           [0022]      FIG. 7  is a perspective view of a distal end of a side rail showing the distal end flange having a pair of spaced apart hooks projecting therefrom for locking engagement with the pins in the longitudinal pin channel member; 
           [0023]      FIG. 8  is a perspective view of a distal end of a slat showing the tenon; and 
           [0024]      FIG. 9  is a perspective view showing a corner post having offset slots spaced apart and in alignment with one another for cooperative engagement with tenons extending from the distal ends of respective slats and showing a vertical post channel extending a selected distance toward each end of the corner post for receiving a longitudinal pin channel therein. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    In one preferred embodiment as shown in  FIGS. 1-9 , the head board  11  and the foot board  13  are identical to one another in bunk bed  10 . The head board  11  and foot board  13  each include a right corner post  15  and a left corner post  12  and connected by three slats  20 . Each post is substantially square and includes an smooth rear surface  17 , a smooth outside surface  19 , an interior surface  21  having a longitudinal groove or channel  14  extending a selected length, depth, and width formed or cut therein with a means for cooperatively engaging a bed side rail, and an interior surface  23  including one or more slots  16  for cooperative engagement with one or more slats  20  extending between a pair of posts  12 ,  15 . Means for mounting the bunk beds one on top of the other in a conventional manner is applicable to the present invention. 
         [0026]    A spring unit, more particularly a flat spring unit, includes a rectangular peripheral frame  39  and a spring support structure  41  stretched across the peripheral frame  39 . At each of the four corners, the peripheral frame  39  is attached to a side rail  40  which is attached to the post by a corner flange  44  extending from the distal end of each side rail  40 . In a typical embodiment, each corner flange  44  includes two vertical hooks  42 , one above the other which extend laterally past the end of the peripheral frame  39  for removable cooperative engagement with the retaining means disposed in the vertical post channels  14  of the corner posts  12 ,  15 . 
         [0027]    As shown in the figures, each one of the distal ends of the head board/foot board slat  20  is machined/milled/molded to a reduced width and height to form a tenon  26  and a dado  22  at a selected location defining a dado face  27  between dado shoulders  23 , and forming a tenon slat shoulder  24  and a tenon distal end  25 . The tenon distal end  25  is disposed within the slot  16  projecting beyond the vertical post channel  14  to abut the slot end wall  29 . The face  27  of the dado  22  formed in the tenon  26  near the distal end faces the vertical post channel  14  and is aligned with and in cooperative engagement with the vertical post channel  14  and the pin channel  30  retained within the vertical post channel  14  by screws. The channel member  30  defines a longitudinal member having a generally U-shaped cross-section with an end wall  31  connecting side walls  32  with a plurality of pins  34  of a selected size and shape disposed between the side walls  32  spaced apart from the end wall  31  and each other at selected positions along the longitudinal member. After the tenon is placed within the socket  16  of the post, the channel member  30  is inserted into the vertical post channel  14  whereby the end wall  31  of the pin channel  30  rests against the face  27  of the dado  22  and the side walls  32  of the pin channel  30  rest against the dado shoulders  23 . The tenon distal end  25  abuts the slot end wall  29  of the post and the tenon slat shoulder  24  abuts the surface  23  of the corner post for locking the slat  20  in position within the post and locking the tenon  26  within the slat slot  16  with the pin channel  30  providing a means for supporting the distal end projecting hooks  42  of the side rail flange  44 , side rail  40  and  41  and spring frame  39  therebetween. 
         [0028]    It is noted that the two corner flanges  44  at each end are parallel with one another and are configured so that the hooks  42  will slip into the open side of channel member  30  and cooperatively engage with the horizontal pins  34 . The bunk bed is assembled by aligning the hooks  42  at one end of the side rail  40  supporting the flat spring unit  41  with the open side of the channel members  30  of the headboard  10  at a selected height and force the hooks down onto the selected pins  34 . The hooks  42  extending from a bracket  44  at the opposite end of the side rail  40  can likewise be inserted into the pin channel member  30  of the footboard  10  preferably at the same height as in the headboard  10  and forced tightly onto the corresponding pins  34 . 
         [0029]    In a preferred embodiment, the sides of posts  12  and  15  which face each other have vertical slots  16  whereby each receive a tenon  26  formed on the distal end of each slat  20 . As best illustrated in  FIGS. 2 ,  3 , and  6 , the posts  12  and  15  each include a U-shaped vertical post channel  14  into which is fastened a vertical U-shaped channel member  30 . The vertical channel member  30  includes horizontal pins  34  which cooperatively engage the vertical hooks  42  on the corner members  44  of the peripheral frame  40  of the flat spring unit  7 , as shown in  FIG. 10 . The channel member  30  contains a plurality of spaced apart pins  34 . The pins  34  are spaced apart to match the spacing between the hooks  42  of corner flanges  44 . This allows the flat spring unit  7  to be placed at any one of a number of vertical positions as determined by the placement of pins  34 . 
         [0030]    As best shown in  FIGS. 2 and 3 , the tenon  26  begins at the shoulder  24  and ends at the end edge  25  of slat  20 . The tenons  26  at each end of slats  20  include a dado  22  which is parallel to the end edge  25  of slat  20 . As seen in  FIG. 9 , the tenon  26  of slat  20  is pushed into socket  16  of post until the shoulder  24  is tight against the side  15  of the post, dado  22  comes into perfect alignment with the channel  14  in side  17  of the post. With the all three of the slats  20  so inserted into the sockets  16  of post  12 , the channel member  30  is now inserted into the channel  14  with the open side of pin channel member  30  facing outwards. At this point, wood screws or other retaining means are inserted and driven into the holes formed in the end wall  31  of the pin channel member  30  and on into the end wall  50  of the vertical post channel  14  to fixedly secure the channel member  30  into the channel  14 . With the channel member tightly secured in channel  14  and in the dados  22 , the slats  20  are also securely held within the post. The channel member  30  is tightly held between the shoulders  23  of the dados  22  so that the slats  20  are tightly secured. 
         [0031]    The opposite ends of the three slats  20  are likewise inserted into the facing sockets  16  of post  13  and, again, the dados  22  perfectly align with the channel  14  of post  13 . Another channel member  30  is inserted and secured with wood screws to complete the headboard or footboard  10 . 
         [0032]    Thus, it can be seen that the corner post sockets  16  and the slat tenons  26  form a mortise joint which can be glued together. However, because the channel member fits tightly into the dados  22  of the tenons  26 , no glue is required to hold the improved mortised joint together. The improved mortise joint can be easily disassembled, if desired, by removing the screws which retain the longitudinal pin channel member into the vertical post channel. 
         [0033]    Depending upon the means of packaging and shipping the bunk beds, the headboard and/or /footboard can be fabricated as a modular unit wherein the slats and posts are constructed as a unit and application of glue to the post and tenon joint further strengthens the joint and bunk bed frame structure. 
         [0034]    As shown in  FIG. 9 , another preferred embodiment utilizes a corner post which includes a peg  52  on the top of the post and correspondingly sized and shaped socket on the bottom of the post for mounting one bunk bed  10  upon another. The embodiment also shows that the vertical post channel  14  and pin channel  30  may be of a selected length or extend the entire length of the post. As shown the slots  16  within the post are offset a selected distance to provide maximum strength to the slat and slot arrangement. Moreover, in the embodiments discussed heretofore, the slots  16  did not extend all of the way through the post; however, it is contemplated that such an arrangement would be within the scope of the present invention. 
         [0035]    The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom, for modification will become obvious to those skilled in the art upon reading this disclosure and may be made upon departing from the spirit of the invention and scope of the appended claims. Accordingly, this invention is not intended to be limited by the specific exemplification presented herein above. Rather, what is intended to be covered is within the spirit and scope of the appended claims.