Abstract:
This invention relates to folding beds and aims at correcting certain shortcomings of all other folding beds. The invention contains the mechanism of a Space-saving Folding Bed the legs of which at both ends automatically unfold when the bed is unfolded for use, and also automatically fold onto the frame when the bed is folded up.

Description:
BRIEF SUMMARY OF THE INVENTION 
     The characteristic feature of this invention is that the legs at both ends of the bed automatically fold onto the frame when the bed is folded up, and that the whole frame of the bed, when folded, may be lowered down between the legs at the middle section of the bed. On account of these improvements, this newly invented Space-saving Folding Bed is very practical, space saving, and convenient at times of moving. We just push the both ends of the bed frame outward, the whole bed will be automatically getting ready for use immediately. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     FIG. 1 View of bed folded 
     FIG. 2 View of bed unfolded 
     FIG. 3 Line sketch of frame of bed when unfolded 
     FIG. 4 Line sketch of bed half folded 
     FIG. 5 Line sketch of both ends when the bed is folded up to vertical position. 
     FIG. 6 Line sketch of frame of bed lowered down 
     FIG. 7 Outline form of slide rail with fixing dent 
     FIG. 8 illustrates the opening of the base of the bed to some angle. 
     FIG. 9, is a further illustration of one embodiment of the base of the bed. 
     FIG. 10, is an illustration of one embodiment of the turn joint. 
    
    
     DETAILED DESCRIPTION 
     Commercially available folding beds may in general be devided into two kinds. Each of these two kinds is convenient in one but inconvenient in another respect. The first kind does not occupy much space, but its legs do not automatically fold onto the frame, which causes inconvenience. The other kind has legs that fold automatically, but the legs of the middle section of the bed cannot be folded, shortened, or lowered, which means that a considerable space is still wasted. To correct these shortcomings and provide improvements for living conditions, the present invention presents the construction of a Space-saving Folding Bed the legs of which at both ends automatically fold onto the frame when the bed is folded and the frame of which, after being folded, can be lowered down very near to the ground. It is convenient and space saving. When it is unlatched at the top, a spring automatically unfolds and puts down the legs and both ends of the bed. 
     In the following, the invention is described with reference to the attached drawings. 
     The invention consists of the following component parts: base of bed 1; slide rails, 2; bed legs under the middle section 3; legs at both ends of the bed 4; connecting rod 5; fixed-angle (approx. 75°-78°) extension rod 6 attached to both bed ends spring 7; turn joints between base of bed and legs at both ends 8 (when bed unfolded, base of bed and bed legs form an angle of 100°); turn joints of legs under the middle section of bed 9 (these legs and base of bed are always in a rectangular position); slide pin 10. 
     FIG. 3 shows the relative position of the component parts of Space-saving Folding Bed when unfolded. When the two halves of base of bed 1 are folded upward, as shown in FIG. 4, because then the angle formed between connecting rod 5 and extension rod 6 is less than 180°, the legs at both ends of the bed 4 fold inward, not outward. When the bed is folded to a near vertical position, as shown in FIG. 5, the position of slide rail 2 is changed, the slide pin 10 is moved slightly upward, and the bed legs at both ends 4 are folded further inward. When the bed is folded to a completely vertical position, as shown in FIG. 6, the frame of the bed slides, by its own weight, down between the legs under the middle section 3. In this position, even if the legs under the middle section 3 were pulled apart, the spring 7 would pull the legs 3 back to the original rectangular position. The force of the spring 7 holds the frame of the bed in a fixed position, and the same force keeps the connecting rod 5 and the legs at both ends of the bed 4 in the proper position when the bed is unfolded. Also, when the slide pin 10 has slid into the fixing dent 11 at the end of the slide rail 2, the whole middle section of the bed is kept in a firm and steady position. 
     FIG. 8 is a further view showing the operative relationship between the various portions of the folding bed on the opening angle begins to exceed 45 degrees. The action of the spring between the two vertical portions of the U-shaped legs tends to pull the legs together forcing the middle section upwardly due to the caming action of slide pin 10 immediately prior to its sliding into fixing dent 11. FIG. 9 is a closer view of the pivotal turn joint of the U-shaped legs forming the bed base. FIG. 10 is illustrative of pivotally connecting the vertical extending legs with the middle section of the bed frame. 
     FIG. 9 is a closer view of the pivotal turn joint 9 connecting legs 3 and base 12 of the U-shaped legs forming the bed base. FIG. 10 is illustrative of pivotally connecting 15 the vertical extending legs 1 with the middle section 14 of the bed frame. 
     Changes in details may be made without departing from the spirit or scope of the invention; but,