Abstract:
A rehabilitation bed especially suitable for helping a patient stand up and begin walking includes a matress split into at least three parts and supported by suitably movable frame suport members, the mattress including a back and head supporting part which is raiseable in the usual way, and separate leg supporting parts which are movable outwardly away from one another so as to provide a central gap where the patient can put his feet without first shifting his waist toward the bed side.

Description:
FIELD OF THE INVENTION 
     This invention relates to a rehabilitation bed suitable especially for stand up and walk training, bowel evacuation training and so on. 
     BACKGROUND OF THE INVENTION 
     In the past, when a patient on a rehabilitation bed attempted to rise up from the bed, stand up on the floor and attempt to start walking, he could not put his feet on the floor without first shifting his waist toward the bed side. Especially to a patient in need of rehabilitation, such a waist shift motion was a heavy burden and, in addition, any conventional bed was very inconvenient for bowel evacuation. 
     To solve these problems, some improved types of beds were offered. Such beds were designed to partially sink down, enabling the patient to rise to a sit-down position without the waist shift motion and then stand up at the sink position or evacuate the bowel at the sit-down position. However, even the improved types do not suffice for walk training because the level gap between the sink position and the floor impeded efforts of the patient to walk and further the sink part of the bed was not easy for the trainee to walk on stably. 
     SUMMARY OF THE INVENTION 
     The present invention was made to solve the problems described above and to provide a rehabilitation bed as enables the patient to put his feet on the floor easily from the position of sitting on the bed and immediately to step forward with no difficulty for walk training or evacuating the bowel. 
     The bed of the present invention is characterized in that the lower mattress supporting the patient&#39;s legs is divided into right and left mobile mattresses which are designed to move apart from one another providing a gap therebetween and providing access to the floor surface. In one embodiment, at least the central parts of the right and left mobile mattresses are designed to descend and split respectively toward the right and left sides. The above-described central control parts of the mobile mattresses are supported by split-plates and the same split-plates are designed to descend and split with their positions kept horizontal toward the right and left sides with use of a parallel link mechanism. 
     In a second embodiment, the right and left mobile parts are designed to move horizontally toward the right and left sides respectively without descending. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an embodiment of the bed of the present invention. 
     FIG. 2 is a plan view of the essential part of the mechanism for the embodiment of the present invention shown in FIG. 1. 
     FIG. 3 is a perspective view of the bed of FIG. 1 at another stage of its use. 
     FIG. 4 shows a diagrammatic view of the descend-split mechanism used in the FIG. 1 embodiment of the bed of the present invention. 
     FIG. 5 is a diagrammatic view of the operation of the drive mechanism used in an embodiment of the bed of the present invention. 
     FIG. 6 and FIG. 7 are diagrammatic view of varied embodiments of the drive mechanism of the present invention. 
     FIG. 8 is a diagrammatic view of another embodiment of the descend-split mechanism of the present invention. 
     FIG. 9 and FIG. 10 are diagrammatic views showing the operation of the descending mobile mattreses of an embodiment of the present invention. 
     FIG. 11 is a schematic plan view showing another embodiment of the bed of the present invention. 
     FIG. 12 is a schematic side view showing the embodiment of FIG. 11 of the bed of the present invention. 
     FIG. 13 is a perspective view showing the construction of the mobile part of the FIG. 11 embodiment of the bed of the present invention. 
     FIG. 14 is an enlarged sectional view showing the support of a slide pipe of the FIG. 11 bed of the present invention. 
     FIG. 15 shows an end view of an embodiment of the present invention taken along the 15--15 line of FIG. 11. 
     FIG. 16 and FIG. 17 show diagrammatical views of the operation of the FIG. 11 embodiment of a bed of the present invention. 
     FIG. 18 schematically shows another embodiment of a bed of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1-10 refer to embodiments of a descending mattress type of bed while FIGS. 11-18 refer to embodiments of a non-descending mattress type of bed, in all embodiments the mattress having side moving capabilities. 
     In FIG. 1 and FIG. 2, bed is shown having main frames 1 made of angle steel with L-shaped sections, which are installed at the right and left sides of the bed. The rear ends (head side) of the main frames 1 are connected rigidly in unity with a head board 2; and the middle parts of the main frames 1 are connected by a connecting frame 3. Under the main frame 1 described above, auxiliary frames 4 made of angle pipe are installed in parallel. The front ends (leg side) of the main frame 1 and auxiliary frame 4 are provided with leg plates 5. 
     An upper mattress 6 is provided, which, as illustrated, can be raised up from a horizontal position with some known mechanism (not illustrated) and functions as the back rest of the patient in the sitting position. The upper mattress 6 has a central portion 6&#39; for supporting the patient&#39;s waist and which is desirably designed to be removable for replacement with a bed pan or chamber pot. The lower mattress 7 supporting the patient&#39;s legs is divided into the right and left mobile mattresses 7a and 7a. 
     Hand rails 25, which bend and overhand inwardly, extend upwardly from the main frames 1. Thus the patient is able to stabilize his position by gripping such hand rails 25 when standing up and starting walk training. The hand rails 25 are desirably removable. 
     FIG. 3 shows the operating mechanism in a state where the mobile mattreses 7a and 7a are removed and split-plates 9, which in the positions of FIGS. 1 and 2 support the mobile mattresses, descend and split toward the right and left sides in coordination with the operation of a link mechanism 8. 
     The link mechanims 8, clearly shown in FIGS. 3 and 4, consists of two parallel links 8a and 8b and operating pieces 8e attached with pin joints 8c and 8d to the tips of said parallel links, the basic end of said parallel link 8a being connected rigidly with a rotary drive shaft 10, and the basic end of the parallel link 8b being connected rotatively with the main frame 1 using a pivot pin 8f. The rotary drive shaft 10 is also pivoted rotatively to the main frame 1. Furthermore, the lengths of the parallel links 8a and 8b (i.e. the distance between the pin joint 8c and the rotary drive shaft 10 and the distance between the pin joint 8d and the pivot pin 8f) are equal and the distance between the rotary drive shaft 10 and pivot pin 8f and the distance between both pin joints 8c and 8d are equal, thus forming in the whole a parallelogram linkage. 
     When the rotary drive shafts 10 are driven to rotate, the operating pieces 8e along with the split plates 9 descend and split toward the right and left sides from the solid line illustrated position to the dot-dot-dash line illustrated position in FIG. 4, with the attitude of the split plates 9 remaining horizontal as illustrated in FIG. 4. The parallel links 8b are bent so as not to interfere with the auxiliary frames 4 when they rotate down as shown in FIG. 4. 
     FIG. 5 shows the drive mechanism of said rotary drive shaft 10, as shown in place in FIG. 2. The output shaft 11a of an electric motor 11 is connected with a right and left hand screw shaft 12 through a joint 11b. The right and left hand screw shaft 12, threaded symmetrically on both the right and left sides, is provided with two travelers 13 engaged with the shaft, one traveler 13 on the right side and the other on the left side. The travelers 13 are pin-connected through connecting rods 14 with the operating pieces 15 fixed to the aforementioned rotary drive shaft 10. Therefore, when the electric motor 11 is powered to rotate the right and left hand screw shaft 12, the travelers 13 move to meet each other or oppositely away from each other along the right and left hand screw shaft 12. The movement of the travelers 13 is transmitted to the rotary drive shafts 10 through the connecting rods 14 and operating pieces 15, whereby the parallel link mechanism 8 is made to operate as shown in FIG. 4. 
     FIG. 6 shows another embodiment of the mechanism to rotate the above-mentioned rotary drive shafts 10, where a disk 17 is made to rotate by a hydraulic jack 16 or the like and the above-mentioned connecting rods 14 are pivoted to the disk 17, thus rotating the rotary drive shafts 10 through operating pieces 15. 
     FIG. 7 shows another embodiment of the mechanism to rotate the rotary drive shafts 10, where the above-mentioned operating pieces 15 are connected with wires 18 which are wound up by a winding pulley 20 through intermediate pulleys 19. The winding pulley 20 is driven with use of a hand lever 21. Specifically in this embodiment, the rotary drive shaft 10 is constantly loaded by the mobile mattresses 7a pulling the wires 18. Thus, easing the hand lever 21 causes the mobile mattresses 7a to descend and split toward the right and left sides. 
     FIG. 8 indicates another embodiment of the above described parallel link mechanism 8, where the basic end of the above-mentioned parallel link 8a is connected to rotate with the main frame 1 with use of a pivot pin 22, and an engaging pin 23 is mounted halfway of the parallel link 8a. In addition,the above-mentioned rotary drive shaft 10 is provided with a push up rod 24 which supports the engaging pin 23 upward by receiving it from the bottom side. 
     As shown in FIG. 9, the mobile mattress 7a is designed to descend and split in the embodiment described above, but the present invention is not limited to same. For instance, among the mobile mattresses 7a, only the inside mattresses 7a&#34; may be designed to descend and split with the outside mattresses 7a&#39; remaining fixed. In this case, the width of each mattress 7a&#39;, 7a&#34; may be determined freely. 
     In FIG. 11 and FIG. 12, a non-descending mattress type of bed is shown having a fixed part 31 and a sideways movable part 32. The fixed part 31 supports the waist and upper half of the patient&#39;s body, and the movable part 32 bears mainly his legs. The same mobile part 32 is divided into a right side mobile part 32a and a left side mobile part 32b. 
     One side (opposite the fixed part) of the right side mobile part 32a is provided with a slide pipe 33a which extends to the left side mobile part 32b, as shown in FIG. 13. Also, one side of the left side mobile part 32b is provided with a slide pipe 33b which extends to the right side mobile part 32a. These slide pipes 33a and 33b are attached as shown in FIG. 14 respectively to a lower position and an upper position. The slide pipe 33a is provided with a U-shaped piece 34a; and the slide pipe 33b with a U-shaped piece 34b. 
     As illustrated in FIG. 14 and FIG. 15, the slide pipes 33a and 33b are supported by many roller bearings 35 mounted on the side of the fixed part 31, thus ensuring the sliding motion to the right and left directions. Furthermore, the other sides of the mobile parts 32a and 32b are also provided with supporting pipes 36a and 36b (see FIG. 12), which are supported by roller bearings 37 mounted on the tips of the support parts 31a and 31b extending from the aforementioned fixed part 31. 
     Operating rods 38a and 38b are provided to rotate from fixed part 31 using pivot pins 39a and 39b. The tips of the operating rods 38a and 38b are provided with pins 40a and 40b which fit into elliptical holes defined by the aforementioned U-shaped pieces 34a and 34b. Oscillating cam members 41a and 41b are connected fixedly with an operating shaft 42, thus rotating together with such shaft on its axis by the manipulation of the hand lever 43. The cam members 41a and 41b are provided with symmetrical slots 41a&#39; and 41b&#39; which hold the pins 44a and 44b of the aforementioned operating rods 38a and 38b, where by the oscillating motion of the oscillating cam members 41a and 41b causes the swinging motion of the operating rods 38a and 38b. 
     When the hand lever at the side of the fixed part 31 is raised as shown in FIG. 16, the oscillating cam members 41a and 41b oscillate on the axis of the operating shaft 42. In concert with the oscillating motion, the pins 44a and 44b of the operating rods 38a and 38b move along the cam slots 41a&#39; and 41b&#39;, thus causing the operating rods 38a and 38b to swing as shown in FIG. 17. In swinging the operating rods 38a and 38b, the pins 40a and 40b at their tips force the U-shaped pieces 34a and 34b of the slide pipes 33a and 33b outward to the right and left sides, thus also forcing outward the right and left mobile parts 32a and 32b. When both the mobile parts 32a and 32b slide outwardly, the floor surface will appear in the central part. 
     When the floor surface appears, the patient, who has beforehand risen halfway with the help of the back rest 45 raised with some conventional drive means, can put his feet on the floor surface, take a sit-down position and then stand up and further step forward with no difficulty. Furthermore, the patient may turn hand rails 46a and 46b attached to the front edges of the mobile parts 32a and 32b as shown in FIG. 17 and use them for support to help start walking. 
     In the above described embodiment, the slide pipes 33a and 33b and support pipes 36a and 36b can be solid bars. Also, a bowel evacuation recess 47 may be provided, in which a chamber pot is contained. 
     In FIG. 18, the mobile parts 32a and 32b are merely pivotable apart from one another and from the fixed part 31. 
     It will be obvious to those skilled in the art that various other changes and modifications may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown in the drawings and described in the specification.