Abstract:
A foldable bed having a frame and a cover attached to the frame. The frame has two handles, four legs and two identical side beams which is linked with four pairs of scissoring bars. All parts are able to be solid therefore a strength thereof can be significantly increased and a noise bring by telescoping tubes may be eliminated.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to a foldable bed, and more particularly, to a foldable bed having a strong structure. 
         [0003]    2. Description of the Prior Art 
         [0004]    Foldable beds have long been developed since they are easily conveyed and occupies smaller space when folded. A foldable bed is disclosed in U.S. patent application Ser. No. 11/987,688. The foldable bed has a frame having two identical side beams each having a pair of groove beams, a first connector contained in a groove of each groove beam, and a leg pivotally connected to each groove beam through the first connector. This kind connection between the side beams and legs is not desirable because each of the side beams must have a groove defined therein. The groove will significantly decrease a strength of the side beam. And secondly, the groove-connector linkage is also not desirable because the connectors are under a great force and often break or self lock in actual use. 
         [0005]    An improved foldable bed is disclosed in the U.S. patent application Ser. No. 12/382,700. The side beams can be solid to increase the strength but the foldable bed must have middle legs of a shape of a tube and contain a telescoping leg therein. This structure of telescoping tubes decreases the strength of the middle legs since they must be hollow. The structure also bring noise since each time in folding and expanding, the telescoping tubes rub with each other. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The main object of the invention is to provide a foldable bed which is both able to be folded and expanded easily and strong. 
         [0007]    Another object of the invention is to provide a foldable bed which is silent in folding and expanding. 
         [0008]    In order to accomplish the above objects, the present invention provides a foldable bed having: 
         [0009]    a frame having a left handle and a right handle, a first left side beam and a second left side beam pivotally connected to the left handle, a first right side beam and a second right side beam pivotally connected to the right handle, a first left, a second left, a first right, and a second right leg respectively pivotally connected to the first left, the second left, the first right, and the second right side beam near a free end of each the side beam, a first left, a second left, a first right, or a second right lower bar respectively pivotally connected to the first left, the second left, the first right or the second right legs in middle of each the leg, a first left, a second left, a first right, or a second right upper bar respectively pivotally connected to a middle of the first left, the second left, the first right and the second right side beam with an end thereof and respectively pivotally connected to a free end of the first left, the second left, the first right, and the second right lower bar with the other end thereof, a left peddling and a right peddling, a first left and a second left tilt bar each having one end pivotally connected to the left peddling and a free end respectively pivotally connected to a middle of the first left and the second left upper bar, a first right and a second right tilt bars each having one end pivotally connected to the right peddling and a free end respectively pivotally connected to a middle of the first right and the second right upper bars, a first left, a second left, a first right, and a second right linking bars each having one end respectively pivotally connected to a middle of the first left, the second left, the first right, or the second right tilt bars and a free end respectively pivotally connected to the left and the right handles, a first end bar pivotally connected to a free end of the first left side beam at one end thereof and to a free end of the first right leg at the other end thereof, an opposite first end bar pivotally connected to a free end of the first right side beam at one end thereof and to a free end of the first left leg at the other end thereof, the first and the opposite first end bars being hinged at about a middle portion hereof and able to scissor with respect to each other, a second end bar pivotally connected to a free end of the second left side beam at one end thereof and to a free end of the second right leg at the other end thereof, an opposite second end bar pivotally connected to a free end of the second right side beam at one end thereof and to a free end of the second left leg at the other end thereof, the first and the opposite second end bars being hinged at about a middle portion hereof and able to scissor with respect to each other, a first middle bar pivotally connected to the left handle at one end thereof and to a point of the first right tilt bar near the right foot at the other end thereof, an opposite first middle bar pivotally connected to the right handle at one end thereof and to a point of the first left tilt bar near the left peddling at the other end thereof, the first and the opposite first middle bars being hinged at about a middle portion hereof and able to scissor with respect to each other, a second middle bar pivotally connected to the left handle at one end thereof and to a point of the second right tilt bar near the right peddling at the other end thereof, an opposite second middle bar pivotally connected to the right handle at one end thereof and to a point of the second left tilt bar near the left peddling at the other end thereof, the first and the opposite second middle bars being hinged at about the middle portion hereof and able to scissor with respect to each other; and,
       a cover attached to the frame.       
 
         [0011]    These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view of the preferred embodiment of a foldable bed of the invention; 
           [0013]      FIG. 2  is an enlarged perspective view of a frame of the foldable bed shown in  FIG. 1 ; 
           [0014]      FIG. 3  is an enlarged perspective view of the frame shown in  FIG. 2  showing a status of half folded; and, 
           [0015]      FIG. 4  is an enlarged perspective view of the frame shown in  FIG. 2  showing a status of being folded. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0016]    With reference to  FIG. 1 , it is a perspective view the preferred embodiment of a foldable bed  1  of the invention, showing a status of the foldable bed  1  when it is expanded. The foldable bed  1  has a frame  2  and a cover  3  attached to the frame  2 . The cover  3  acts as bedplate as the foldable bed  1  is expanded. 
         [0017]    As shown in  FIG. 2 , the frame  2  has a left handle  20  and a right handle  20 ′, a first left side beam  21   a  and a second left side beam  21   b  pivotally connected to a left handle  20 , and a first right side beam  21   a ′ and a second right side beam  21   b ′ pivotally connected to a right handle  20 ′. 
         [0018]    A first left, a second left, a first right, or a second right leg  22   a,    22   b,    22   a ′, or  22   b ′ is respectively pivotally connected to the first left, the second left, the first right, or the second right side beam  20   a,    20   b,    20   a ′ or  20   b ′ near a free end of each side beam  20   a,    20   b ,  20   a ′ or  20   b ′. A first left, a second left, a first right, or a second right lower bar  23   a,    23   b ,  23   a ′, or  23   b ′ is respectively pivotally connected to the first left, the second left, the first right or the second right leg  22   a,    22   b,    22   a ′, or  22   b ′ in the middle of each leg  22   a,    22   b ,  22   a ′, or  22   b ′. A first left, a second left, a first right, or a second right upper bar  24   a,    24   b ,  24   a ′, or  24   b ′ is respectively pivotally connected to a middle of the first left, the second left, the first right or the second right side beam  20   a,    20   b,    20   a ′ or  20   b ′ with an end thereof and respectively pivotally connected to a free end of the first left, the second left, the first right, or the second right lower bar  23   a,    23   b,    23   a ′, or  23   b ′ with the other end thereof. The frame  2  further has a left peddling  25  and a right peddling  25 ′. A first left and a second left tilt bar  26   a,    26   b  each has one end pivotally connected to the left peddling  25  and a free end respectively pivotally connected to a middle of the first left and the second left upper bar  24   a  and  24   b.  A first right and a second right tilt bar  26   a ′,  26   b ′ each has one end pivotally connected to the right peddling  25 ′ and a free end respectively pivotally connected to a middle of the first right and the second right upper bar  24   a ′ and  24   b ′. A first left, a second left, a first right, or a second right linking bar  27   a,    27   b,    27   a ′, or  27   b ′ each has one end respectively pivotally connected to a middle of the first left, the second left, the first right, or the second right tilt bar  26   a,    26   b,    26   a ′, or  26   b ′ and a free end respectively pivotally connected to the left and the right handle  20  or  20 ′. 
         [0019]    A first end bar  30  is pivotally connected to a free end of the first left side beam  21   a  at one end thereof and to a free end of the first right leg  22   a ′ at the other end thereof. An opposite first end bar  30 ′ is pivotally connected to a free end of the first right side beam  21   a ′ at one end thereof and to a free end of the first left leg  22   a  at the other end thereof. The first and the opposite first end bars  30 ,  30 ′ are hinged at about the middle portion hereof and able to scissor with respect to each other. A second end bar  31  is pivotally connected to a free end of the second left side beam  21   b  at one end thereof and to a free end of the second right leg  22   b ′ at the other end thereof. An opposite second end bar  31 ′ is pivotally connected to a free end of the second right side beam  21   b ′ at one end thereof and to a free end of the second left leg  22   b  at the other end thereof. The first and the opposite second end bars  31 ,  31 ′ are hinged at about the middle portion hereof and able to scissor with respect to each other. 
         [0020]    A first middle bar  32  is pivotally connected to the left handle  20  at one end thereof and to a point of the first right tilt bar  26   a ′ near the right foot  25 ′ at the other end thereof. An opposite first middle bar  32 ′ is pivotally connected to the right handle  20 ′ at one end thereof and to a point of the first left tilt bar  26   a  near the left peddling  25  at the other end thereof. The first and the opposite first middle bars  32 ,  32 ′ are hinged at about the middle portion hereof and able to scissor with respect to each other. A second middle bar  33  is pivotally connected to the left handle  20  at one end thereof and to a point of the second right tilt bar  26   b ′ near the right peddling  25 ′ at the other end thereof. An opposite second middle bar  33 ′ is pivotally connected to the right handle  20 ′ at one end thereof and to a point of the second left tilt bar  26   b  near the left peddling  25  at the other end thereof. The first and the opposite second middle bars  33 ,  33 ′ are hinged at about the middle portion hereof and able to scissor with respect to each other. 
         [0021]    A sleeve  28   a,    28   b,    28   a ′, or  28   b ′ is provided covering on and being slidable with respect to respect first left, second left, first right, or second right tilt bar  26   a,    26   b,    26   a ′, or  26   b ′ between respect first left, second left, first right, or second right linking bar  27   a,    27   b,    27   a ′, or  27   b ′ and respect opposite first middle, opposite second middle, first middle or second middle bar  32 ′,  33 ′,  32  or  33 . A reinforcing bar  29   a,    29   b,    29   a ′, or  29   b ′ is pivotally connected to each sleeve  28   a,    28   b,    28   a ′, or  28   b ′ at one end thereof and to a middle of respect first left, second left, first right, or second right linking bar  27   a,    27   b,    27   a ′, or  27   b ′ at the other end thereof. 
         [0022]    When a user needs to fold the foldable bed  1  of the invention, he is able to step on the left peddling  25  with one of his foot and then pull the left handle  20  upward. The first and the second left side beam  21   a  and  21   b  will rotate round the left handle  20 . The first and the second left tilt bar  26   a  and  26   b  will rotate round the left peddling  25  at the same time under a pulling force from the first and the second right linking bars  27   a  and  27   b.  As shown in  FIG. 3 , the first and the second left upper bars  24   a  and  24   b  will rotate towards the first and the second left side beam  21   a  and  21   b,  respectively. For better illustration of movement of the frame  2 , the soft cover  3 , which will affect the operation of folding and expanding slightly, is not shown in these  FIGS. 2 ,  3  and  4 . The first and the second left leg  22   a  and  22   b  will be pulled to rotate towards the first and the second left side beam  21  a and  21   b.  When the foldable bed  1  is fully expanded as shown in  FIGS. 1 and 2 , the sleeves  28   a,    28   b,    28   a ′ and  28   b ′ are stopped by and rest on respect opposite first middle, opposite second middle, first middle or second middle bars  32 ′,  33 ′,  32  or  33 . In folding, the sleeves  28   a,    28   b,    28   a ′ and  28   b ′ start to leave respect middle bars  32 ′,  33 ′,  32  or  33 , as shown in  FIG. 3 . When the user pull the handle  20  upward, each pair of end bars, including the first and the opposite first end bars  30 ,  30 ′, the second and the opposite second end bars  31 ,  31 ′, the first and the opposite first middle bars  32 ,  32 ′, and the second and the opposite second middle bars  33 ,  33 ′, will scissor upward. Meanwhile, the left side and the right side of the frame  2  move towards each other. Keep pulling the handle  20 , the foldable bed  1  is able to be fully folded, as shown in  FIG. 4 . A reverse operation will be able to expand the foldable bed  1 . The user is also able to fold and expand the foldable bed  1  by stepping on the right peddling  25 ′ and pulling or pushing the right handle  20 ′. 
         [0023]    From above description, it could be seen that without the grooved side beams and the telescoping tubes, the foldable bed  1  may have compact and strong legs and side beams. And moreover, it is able to be more silent in operation. 
         [0024]    One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. It will thus be seen that the objects of the present invention have been fully and effectively accomplished. Its embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.