Abstract:
A variable bed includes a foldable bed having a plurality of bed units pivotally joined with one another normally lying on a bed frame positioned under the foldable bed; a central jack capable of raising a bed unit of a back portion of the foldable bed for forming a reclining bed or a folding chair on the frame; two end jacks for raising a head portion and a foot portion of the bed for forming a concave bed or for suspending the bed above the frame for serving as a hammock; and a driving motor as controlled by several clutches for driving the jacks or for moving the bed units frontwardly for converting a reclining bed to a folding chair to allow several front bed units to be pendant on a front end wall of the bed frame.

Description:
BACKGROUND OF THE INVENTION 
     A conventional bed is always made as a fixed type, which is not suitable for resuscitation or leisure purposes. A hospital bed may be adjusted to obtain its leaning positioning such as for lifting a patient&#39;s head or feet. However, the hospital bed can not serve as a hammock for leisure purpose. The conventional (hospital) bed is manually adjusted to a fixed leaning angle, not suitable for excercise or resuscitation use. If for meeting the requirement of plural resuscitation and leisure movements, several kinds of beds or chairs should be provided which can increase installation cost and may occupy a large space, especially not allowed in an apartment in a crowded city. 
     It is therefore expected to invent a variable bed having multiple functions for resuscitation or leisure purposes. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a bed which can be adjusted to be a flat bed, a reclining bed, a folding chair, a concave bed with two end portions inclined upwardly, and a hammock for physical resuscitation or leisure purposes by selectively depressing a switch button for any desired bed positioning and movement. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view illustration of the present invention. 
     FIG. 1a is a side view of the present invention. 
     FIG. 2 shows a telescopic rod means for suspending a hammock in accordance with the present invention. 
     FIG. 3 shows an engagement of an arcuate hook portion of the telescopic rod means with a pair of supporting and pivoting rollers of the present invention. 
     FIG. 3a is a side view of FIG. 3. 
     FIG. 4 shows an upper portion of a central jack of the present invention. 
     FIG. 4a is a side view of FIG. 4. 
     FIG. 5 shows a locking or unlocking mechanism of the bed on the bed frame of the present invention. 
     FIG. 6 shows a flat bed in accordance with the present invention. 
     FIG. 7 shows a reclining bed of the present invention. 
     FIG. 8 shows an upstanding folding chair of the present invention. 
     FIG. 9 shows a concave bed of the present invention. 
     FIG. 10 shows a hammock in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION 
     The present invention comprises: a lifting means 100 including a plurality of arcuate jacks 141, 142, 143; a foldable bed 200 comprised of a plurality of foldable linked bed units 2a, 2b, 2c, 2d, 2e; a driving means 300 and a bed frame 400 for supporting the bed 200 thereon and for encasing the driving means 300 therein. The bed 200 may be upholstered for comfortable lying or seating use. 
     As shown in FIGS. 6, 7, when it is intended to variate the flat bed as shown in FIG. 6 to be a reclining bed as shown in FIG. 7, a selector switch button 7 is actuated by rotating the button 7 to a position having a marking of &#34;reclining bed&#34; to issue a signal to a clutch controller 24 of a central arcuate jack 141 for coupling clutch 23 with a driving motor 25 for rotating a worm and gear 151 for raising a pulley 161. A drafting wire 191 is wound on the pulley 161 having its one end of the wire 191 secured to a fixed portion of a housing 39 of the driving means 300 and having the other end of the wire 191 secured to a bottom portion of a crank shaft 141a of the central arcuate jack 141. The rising of the pulley 161 will raise the crank shaft 141a movably held in a jack sleeve 141b having a longitudinal slot (not shown) formed in the sleeve 141b for the movement of the wire 191 to allow a contact roller 9 pivotally formed on a top portion of the jack 141 (FIG. 4) to raise a back portion bed unit 2e of the foldable bed 2 about a pivot 52 for an upward movement of the bed unit 2c. A pair of armrests 81, 82 are pivotally connected to the bed 200 by forming a parallelogram linkage and are raised by pivotting the linkage about the pivots 61, 62, 63 and 52 as shown in FIG. 7. When the back portion unit 2e is raised to a leaning angle about 75 degrees, the power is switched off to form a reclining bed as shown in FIG. 7. By rotating the switch button 7 to a positive having a &#34;flat bed&#34; marking, the above-mentioned operation is reversed to lay down the bed 200 on the frame 400. 
     When raising the central jack 141, a pair of guide rollers 213 are formed in an upper opening of the jack sleeve 141b for guiding the jack 141. 
     When it is required to pose an upstanding folding chair as shown in FIG. 8, the switch button 7 is selectively rotated to a marking of &#34;folding chair&#34; to transmit a signal to the clutch controller 24 to form the reclining bed as above-mentioned. Then the clutch controller 24 is actuated to give an instruction to stop the operation of the clutch 23 and initiate a clutch controller 36 of a forwarding clutch 38 to start a forwarding operation of the driving means 300 to rotatably drive at least a forwarding wheel 37 on a wheel rail 35 formed on a bottom of the frame 400 as shown in FIG. 1a. The driving means 300 may also be provided with other supporting rollers rotatably running on at least a roller rail 34 formed on the bottom of frame 400. Since the central jack 141 is mounted in a housing 39 which may be insulated for preventing noise pollution from the movable driving means 300, the bed 200 is pushed frontwardly in an arrow direction F as shown in FIG. 7 by rotatably running the rollers 3 on the frame 400 to allow the first and second bed units 2a, 2b to be pendant on a front vertical wall of the frame 400. Two pivots 4a, 4b are provided for a downward movement of the bed units 2a, 2b for helping such a pendant movement of bed units 2a, 2b. A front telescopic transmission shaft 181 is retracted and a rear telescopic transmission shaft 182 is extended during the forwarding of the driving means 300, whereas louvers 40 adapted for shielding the driving means 300 and frame 400 slidably held in guide grooves 41 are pushed frontwardly to shield the front recess 400a, while leaving a rear recess 400b not shielded. After positioning the upright folding chair shown in FIG. 8, the power will be automatically switched off, thereby serving a sofa for comfortable seating. By depressing the button for reversing the above-mentioned steps, the &#34;chair&#34; can then be returned to its original status to be a flat bed. 
     For positioning a concave bed as shown in FIG. 9, the switch button 7 should be first rotated to the marking of &#34;flat &#34; to flatten the bed 200 and then rotated to a marking of &#34;concave bed&#34; to transmit a signal to a clutch controller 33 and clutch 32 for driving a directional bearing 17, telescopic transmission shafts 181, 182, dynamic transmission joints 421, 422 so as for rotating two sets of worms and gears 152, 153 for raising two pulleys 162, 163 and raising two crank shafts 142a, 143a of two end arcuate jacks 142, 143 formed on opposite ends of the frame 400. Each crank shaft 142a or 143a will be lifted as guided by a pair of rollers 211, 212 pivotally mounted on an upper opening of each sleeve 142b or 143b by the jack 142 or 143. Two wires 192, 193 are respectively wound on the two pulleys 162, 163, each wire having its one end secured to a bottom of each crank shaft 142a or 143a and having the other end of the wire secured to the frame 400, so that upon the rising of the pulleys 162, 163, the crank shafts 142a, 143a will be pulled upwardly. Each crank shaft 143a or 142a is provided with two supporting and pivoting rollers 201 in a top opening of the shaft so that upon a rising of the shaft, a port 221 defined by the two rollers 201 will be engaged with a central hook portion 1h of each suspending telescopic rod means 1a or 1b which is secured to a head portion or feet portion of the bed 200 as shown in FIG. 3 so as to lift the top and feet portions of the bed 200 as shown in FIG. 9 for forming a concave bed for lying or sleeping purpose. An electromagnetic latch 12 still locks the central portion of the bed 200 and two pivotal joints 51, 52 are provided for upwardly moving the two end portions of the bed 200. Two armrests 81, 82 are also raised for resting a user&#39;s arms. After finishing the positioning of the concave bed, the power will be automatically switched off. 
     If for forming a hammock as shown in FIG. 10, the button 7 is shifted to a marking of &#34;hammock&#34; to continuously operate the present invention from the concave bed as shown in FIG. 9. The signal transmitted to the clutch controller 33 will continuously lift the two jacks 142, 143 and the electromagnetic latch 12 is unlocked to separate the bed 200 from the housing 39 and a recovery line 13 is loosened by uncoupling a clutch 28 of the recovery line as shown in FIG. 5 for a free rotation of a winding reel 30 which is provided to rewind the recovery line 13. A cam shaft 27 is rotated as driven by the driving motor 25 by means of a transmission belt 31 as shown in FIG. 1, 1a to oscillate a cycloid line 26 secured between the bed 200 and the cam shaft 27 so as to shake the &#34;hammock&#34; bed 200 as shown in FIG. 10 for comforting a user lying on the bed. 
     For returning the hammock bed to a flat bed, the switch button is actuated on the marking of &#34;flat bed&#34; to flatten the bed, wherein the clutch controller 29 of clutch 28 is acted to rotate the winding reel 30 for rewinding the recovery line 13 backward onto the reel 30 to recover the bed 200 downwardly to lay down on the frame 400. The loosening or recovery of the line 13 as shown in FIG. 5 is like flying a kite. When the latch 12 is actuated to unlock the bed 200 from housing 39, a plug 10 securing the line 13 to a bed bottom is raised to disengage from a plug holder (socket) 10a formed in the housing 39 since the line 13 is no longer tightenend by the winding real 30, allowing a free shaking operation of the hammock bed driven by the cam shaft 27 and cycloid line 26. After recovering the line 13 by the winding reel 30, the plug 10 is received into socket 10a, and the latch 12 is actuated to lock the bed 200 with housing 39 for stabilizing the bed. 
     The present invention can provide multiple functions, such as for serving a flat bed, a folding chair, a reclining bed, a concave bed, or a hammock for diversified uses to be superior to any conventional bed of single function and use. 
     The suspending telescopic rod 1a as shown in FIG. 2 includes an inner pipe telescopically received in an outer pipe, both inner and outer pipes being tensioned by a spring 1s and being gravitationally stretched to allow a spring retainer 1r of the inner pipe to engage an enlarged portion 1e formed on an opening of the outer pipe when a user lies on the bed. The inner or outer pipes are preferably made with polygonal cross section for preventing any axial rotation of the pipes for ensuring the engagement between the hook portion 1h with the two rollers 201. 
     Although an electrical control circuit is provided in this invention to automatically switch off the motor running, there may still be provided with several limit switches or safety. stoppers for limiting a reciprocating or moving operation of any moving element of the present invention. 
     For smoothly running each of the three jack shafts 141a, 142a, 143a, a pair of rollers 213a, 212a, 211a are formed on each shaft to be slidably contacted with each sleeve 141b, 142b, 143b. All shafts 141a, 142a, 143a are automatically recovered to their lower position as restored by each restoring spring (not shown) normally retained on a bottom portion of each sleeve.