Abstract:
A retractable bed mechanism is disclosed. The bed mechanism comprises a sitting pad, a sitting back, a leg seat and a base seat interconnected by a plurality of linking rods and two driving means. The driving means drives the linking rods so as to drive the sitting pad, the sitting back and the leg seat so as to provide various sitting or laying or upright position to the user which facilitates face to face conversation or accessible to objects or other activities.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     (a) Technical Field of the Invention  
         [0002]     The present invention relates to retractable bed mechanism, and in particular, to a bed mechanism which can provide the user in a sitting position, a laying position, or upright position to carry out an activity, and to promote the activity of the joints of the body and blood circulation.  
         [0003]     (b) Description of the Prior Art  
         [0004]     Convention wheelchair only allows a user to sit upright on the chair and provides only movement but does not provide a resting position or changing of sitting position to the user. As a result, hospitals need wheelchairs of various sizes and specification for patient of various sizes. This will increase the cost of operation of the hospital. Further, as the wheelchair has a fixed height, it does not provide an appropriate height for the user to access to an object.  
         [0005]     Conventional beds for patient are generally of two retracting position i.e., laying position or sitting position. It is convenient for the bed to be adjusted in a sitting position. However, the bed structure is unlike a wheelchair which is moveable from one place to another. The users, due to prolong period in one fixed position, may have poor blood circulation and therefore, the joints or other parts of the body are impaired. Thus, the purpose of rehabitation of the user will not be achieved. In addition, the bed structure will not allow the user to access to an object. In view of the above, it is an object of the present invention to provide a retractable bed mechanism which can mitigate the above drawbacks.  
       SUMMARY OF THE INVENTION  
       [0006]     The primary purpose of the present invention is to provide a retractable bed mechanism which facilitates conversation, accessible to objects, promote movement of joints of the body, and blood circulation. The bed mechanism can be adjusted in a laying position, upright position, or a sitting position.  
         [0007]     A main object of the present invention is to provide a retractable bed mechanism comprising a base seat having an arch-shaped guiding slot with one end facing the front side of the base seat; a first driving means perpendicularly mounted to the base seat and having a first retractable rod which retracts upwards; a second driving means swing-mounted at the bottom end thereof to the base seat and having a second retractable rod which retracts upwards; a swinging rod having an upper end swing-mounted to the upper end of the first retractable rod and the bottom end thereof being extended to the arch-shaped guiding slot and moving along the arch-shaped guiding slot; a first bottom rod having the front end swing-mounted to the swinging rod; a second bottom rod having a rear end swing-mounted to the intersection between the swinging rod and the first bottom rod; a sitting pad having the front end swing-mounted to the upper end of the second retractable rod, and having a middle section being swing-mounted to the upper end of the first retractable rod; a back having the bottom end swing-mounted to the rear end of the first bottom rod, and having the bottom section being swing-mounted to the rear end of the sitting pad; and a leg seat having an upper end provided with a pivot section and the top and bottom position of the pivot section provided with a top pivot hole and a bottom pivot hole, wherein the top pivot hole is provided at the front end of the sitting pad, and the bottom pivot hole is provided at the front end of the second bottom rod.  
         [0008]     The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.  
         [0009]     Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is an upright sitting position in accordance with the present invention.  
         [0011]      FIG. 2  is a schematic view showing elevation and lowering of the bed mechanism of the present invention.  
         [0012]      FIG. 3  is a schematic view showing the upright position of the present invention.  
         [0013]      FIG. 4  is a schematic view showing the laying position of the present invention.  
         [0014]      FIG. 5  is a schematic view showing the base seat connected to a holding seat of the present invention.  
         [0015]      FIG. 6  is an implementation view of the base seat with an appropriate height in accordance with the present invention.  
         [0016]      FIG. 7  is a schematic view showing the mounting of wheels to the bed mechanism of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]     The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.  
         [0018]     Referring to  FIG. 1 , there is shown a retractable bed mechanism comprising a base seat  10  having an arch-shaped guiding slot  11  with one end facing the front side of the base seat  10 , a first driving means  20  perpendicularly mounted to the base seat  10  and having a first retractable rod  200  which retracts upwards; a second driving means  21  swing-mounted at the bottom end thereof to the base seat  10  and having a second retractable rod  210  which retracts upwards; a swinging rod  30  having an upper end swing-mounted to the upper end of the first retractable rod  200  and the bottom end thereof being extended to the arch-shaped guiding slot  11  and moving along the arch-shaped guiding slot  11 , a first bottom rod  40  having the front end swing-mounted to the swinging rod  30 , a second bottom rod  41  having a rear end swing-mounted to the intersection between the swinging rod  30  and the first bottom rod  40 , a sitting pad  50  having the front end swing-mounted to the upper end of the second retractable rod  210 , and having a middle section being swing-mounted to the upper end of the first retractable rod  200 , a sitting back  51  having the bottom end swing-mounted to the rear end of the first bottom rod  40 , and having the bottom section being swing-mounted to the rear end of the sitting pad  50 , and a leg seat  52  having an upper end provided with a pivot section  520  and the top and bottom position of the pivot section  520  provided with a top pivot hole  521  and a bottom pivot hole  522 , wherein the top pivot hole  521  is provided at the front end of the sitting pad  50 , and the bottom pivot hole  520  is provided at the front end of the second bottom rod  41 , a wheel rod  60  having one end provided with a pulley  61  which rotates and the other end swing-mounted to the upper end of the first retractable rod  200 ; and a support rod  70  having one end swing-mounted to the base seat  10  and the other end swing-mounted to the wheel rod  60 .  
         [0019]     As shown in  FIG. 2 , when the first driving means  20  and the second driving means  21  driving the first retractable rod  200  and the second retractable rod  210  are simultaneously and of same length, and the swinging rod  30  and the second retractable rod  200  are in parallel, then the first bottom rod  40  and the second bottom rod  40  are in a straight line, and the sitting pad  50  and the first bottom rod  40  are in parallel. Thus, the user sitting on the sitting pad  50  can elevate or lower then sitting pad  50 .  
         [0020]     Referring to  FIG. 3 , when the first retraction rod  200  of the first driving means  20  is extended, the second retraction rod  210  of the second driving means  21  is retracted. The front end of the sitting pad  50  will tilt downward to interlink the second driving means  21  to swing backward. The leg sit  52  will be subjected to the pulling of the second base rod  41  and move downward vertically, and at the same time, the sitting back  51  will be urged by the first bottom rod  40  to move upward. Thus, the entire bed mechanism is in an upright position.  
         [0021]     Referring to  FIG. 4 , when the first retraction rod  200  and the second retraction rod  210  are simultaneously retracted, the lower end of the swinging rod  30  will swing along the arch-shaped guiding slot  11  to move forward. Thus, the first bottom rod  40  and the second bottom rod  41  are moved forward horizontally such that the first bottom rod  40  pulls the bottom end of the sitting back  51  and the top end of the sitting back  51  moves backward to a laying position. At the same time, the second bottom rod  41  drives the leg seat  52  from the bottom pivot hole  522  such that the bottom end of the leg seat  52  will swing upward to an angle. Thus, the entire structure is in a laying position.  
         [0022]     As shown in  FIG. 4 , when the bed structure is at a laying position, the pulley  61  will be driven by the wheel rod  60  and the support rod  70  and slide-support at the ground so as to form into a safety mechanism to prevent backward tilting.  
         [0023]     Referring to  FIG. 5 , the base seat  10  is secured to a holding seat  80  to use as a fixed type of rehabitation seat. As shown in  FIG. 6 , the base seat  10  is provided with an appropriate height for securing on the ground as a fixed type of rehabitation seat. As shown in  FIG. 7 , the base seat  10  is provided with wheels  81  for use as wheelchair.  
         [0024]     In view of the above, there are four sections of movement of the retractable bed mechanism by means of driving the first driving means  20  and the second driving means  21 , wherein:  
         [0025]     The first section: When the first retraction rod  200  and the second retraction rod  210  are simultaneously retracted at the length of the middle section, i.e., the normal sitting position, it allows the user to have conversation with a person in a sitting position.  
         [0026]     The second section: When the first retraction rod  200  and the second retraction rod  210  are fully extended out from the middle section to the full extended position, or from the full extended position to the middle section length, i.e., lowering elevation position, the user can access to objects placed on a higher position.  
         [0027]     The third section: When the first retraction rod  200  and the second retraction rod  210  are simultaneously retracted from the middle section length, that is the length position, the user is allowed to rest by laying on the bed.  
         [0028]     The forth section: When the first retraction rod  200  is fully extended out, and the second retraction rod  210  is fully retracted in, that is at the upright position, the pressure at the back and buttock section of the user are reduced so as to avoid unsmooth flowing of blood.  
         [0029]     If the first section, the third section or the first section and the forth section or the third section, the third section and the forth section are repeated, the waist joint and the knee joints are provided with appropriate exercise, which enables rehabitation of the patient.  
         [0030]     It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.  
         [0031]     While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.