Abstract:
An electric inversion table includes a base, a bench and a driving device. The bench is disposed on the base and is rotated between a horizontal position and a vertical position. The driving device connects the bench to the base for driving the bench to rotate between the horizontal position and the vertical position. When power failure occurs or a motor of the driving device is out of order, users can release locked status by a clutch of the driving device so as to turn the bench from the vertical position back to the horizontal position safely by the body weight.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an electric inversion table, especially to an electric inversion table in which a user can rotate from an inverted position to a horizontal position by body weight when the power is gone. 
     By flipping the body over, people inversion has a plurality of therapeutic benefits including increased blood circulation, improved body flexibility, enhanced immunity, reducing pain in scoliosis, stretch muscles, etc. For people doing exercise or rehabilitation patients, they can be in an inverted position with the help of an inversion table. However, negative effects and potential dangers are also associated with inversion therapy so that people are unable to hang upside down for a long period of time. 
     There are multiple kinds of inversion tables available on the market such as those revealed in U.S. Pat. No. 8,480,543 and U.S. Pat. No. 8,556,787. Users can hang upside down and turn back by their moving hands moving vertically to operate a board or a bench of the inversion table. The inversion table requires no external power source. Another kind of inversion table includes a power driving device for driving the board or the bench to move to an inverted position and turn back. This is an electric inversion table that is more convenient to use and power-saving. Yet while the electric inversion table is in use and tilted partially, the user together with the electric inversion table is in the inverted position and unable to come back to the upright position once a power supply is out of order such as power failure or the driver&#39;s disorder. Without help from others, the user is unable to get out of the inversion table safely by himself. Thus the risk of using the electric inversion table is increased and this causes less popularity of the electric inversion table. 
     SUMMARY OF THE INVENTION 
     Therefore it is a primary object of the present invention to provide an electric inversion table with high safety, high stability and long service life. 
     In order to achieve the above object, an electric inversion table of the present invention includes a base, a bench and a driving device. While in use, the base is stably set on a plane (such as ground or floor). A pivot hole is disposed on a top end of the base and a support seat is disposed on a bottom surface of the bench. The support frame is arranged with a pivot hole corresponding to the pivot hole of the base. The bench and the base are pivotally connected by a pivot shaft passed through the two pivot holes. Thus the bench is rotated between a horizontal position and a vertical position relative to the base. A receiving surface which users can lean on at an inverted angle is arranged at a top surface of the bench. The driving device connects the bench to the base for driving the bench to rotate between the horizontal position and the vertical position relative to the base. 
     The driving device consists of a motor, at least one gear, a clutch and a pull member. The motor is set at the base while the gear is connected to the motor to be driven to rotate by the motor. One side of the gear is projecting to form a gear shaft that is corresponding to the pivot hole of the support seat and the pivot hole of the base to be connected to and fixed by the pivot shaft. The clutch is arranged between the support seat of the bench and the gear. The clutch includes a hole arranged axially and penetrating thereof so as to be movably arranged at an outer side of the gear shaft of the gear and moved along the longitudinal direction of the gear shaft. The clutch further includes a first end portion at one end and a second end portion at the opposite end. The first end portion is disposed with at least one projection axially while the support seat of the bench is arranged with at least one slot corresponding to and locked with the projection. The second end portion of the clutch is set with a neck portion whose diameter is smaller than that of the first end portion. A spring is mounted at an outer side of the neck portion while two ends of the spring are elastically against the first end portion of the clutch and the gear respectively. The gear and the support seat of the bench are connected elastically by the projection of the clutch and the slot of the bench locked with each other and passed through the spring. Thus the clutch is rotated along with the gear. As to the pull member, it is movably passed through the through holes of the gear. The pull member includes a fixing end fixed at the first end portion of the clutch and an operation end arranged opposite to the fixing end. The operation end is located at an outer side of the end of the gear without the gear shaft and used for users to pull. Thus the clutch is driven to move synchronously by the pull member the user pulled. 
     When the projection of the clutch is mounted in the slot of the bench, the motor drives the gear and the clutch to rotate, and further drives the bench to rotate between the horizontal position and the vertical position. 
     While the projection of the clutch and the slot of the bench are separated from each other, the bench is unable to be driven by the motor through the rotation of the gear and the clutch. 
     When the bench is at the vertical position and the power is off or the driving motor fails, the user can pull the operation end of the pull member outward to drive the clutch moving outward, toward the gear. Thus the projection of the clutch and the slot of the support seat of the bench are separated from each other and the spring is compressed. Now the user can drive the bench to move from the vertical position to the horizontal position by the body weight and then release the pull member. The projection of the clutch is locked into the slot of the support seat of the bench again by the elastic recovery force of the spring. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment according to the present invention; 
         FIG. 2  is an explosive view of the embodiment in  FIG. 1  according to the present invention; 
         FIG. 3  is a partial explosive view viewed from a bottom side of the embodiment in  FIG. 1  according to the present invention; 
         FIG. 4  is a partial enlarged view viewed from a rear side of the embodiment in  FIG. 1  according to the present invention; 
         FIG. 5  is a vertical cross section of the embodiment in  FIG. 4  according to the present invention; 
         FIG. 6  is a schematic drawing showing a projection of a clutch and a slot of a support seat of a bench locked with each other in an embodiment of the present invention; 
         FIG. 7  is a schematic drawing showing a projection of a clutch and a slot of a support seat of a bench separated from each other in an embodiment of the present invention; 
         FIG. 8  is a schematic drawing showing an embodiment of the present invention is at a horizontal position; 
         FIG. 9  is a schematic drawing showing an embodiment of the present invention is at a vertical position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Refer to  FIG. 1  and  FIG. 2 , an electric inversion table  1  of the present invention includes a base  10 , a bench  20  and a driving device  30 . While in use, the base  10  is stably set on a plane (ground or floor is preferred). A support frame  11  is disposed on a top end of the base  10  and the support frame  11  is arranged with a pivot hole  12 . 
     The bench  20  is rotatably disposed on the base  10 . A receiving surface  21  which users can lean on at an inverted angle is arranged at a top surface of the bench  20  while a support seat  22  is set on a bottom surface of the bench  20 . The support seat  22  includes at least one pivot hole  221  that is corresponding to the pivot hole  12  of the base  10 . A pivot shaft  23  is passed through the pivot hole  221  of the support seat  22  and the pivot hole  12  of the base  10  so as to pivotally connect the bench  20  and the base  10 . Thus the bench  20  can rotate between a horizontal position (as shown in  FIG. 8 ) and a vertical position (as shown in  FIG. 9 ) relative to the base  10 . The bottom surface of the bench  20  is further arranged with a straight frame  24  while a fixing member  25  is set on one end of the straight frame  24  and used for fixing users&#39; feet so as to make the user lean on the bench  20  and hang upside down. 
     The driving device  30  connects the bench  20  to the base  10  for driving the bench  20  to rotate between the horizontal position and the vertical position relative to the base  10 . The driving device  30  consists of a motor  31 , at least one gear  32 , a clutch  33  and a pull member  34 . 
     As shown in  FIG. 3 , the motor  31  is installed at the support frame  11  of the base  10 . The gear  32  is connected to the motor  31  for being driven to rotate by the motor  31 . One side of the gear  32  is projecting to form a gear shaft  321 . The gear shaft  321  is corresponding to the pivot hole  221  of the support seat  22  and the pivot hole  12  of the base  10  to be connected to and fixed by the pivot shaft  23 . A rack  35  is disposed between the gear  32  and the motor  31  to be linked with the gear  32  and the motor  31 . One end of the rack  35  is connected to the motor  31  for being driven to move linearly and reciprocally while the other end of the rack  35  is engaged with the gear  32 . When the motor  31  drives the rack  35  to move straight, the gear  32  is driven to rotate by the rack  35 . The gear  32  and the gear shaft  321  can be integrated into one part or two separated parts fastened with each other. For example, the gear  32  and the gear shaft  321  are disposed with a tapped hole  32   a ,  321   a  respectively and correspondingly. Thus the gear  32  and the gear shaft  321  are connected and integrated by a locking screw  36  passing through the tapped hole  32   a  of the gear  32  and the tapped hole  321   a  of the gear shaft  321 . Moreover, the pivot shaft  23  is set with a tapped hole  23   a  corresponding to and communicating with the tapped hole  32   a  of the gear  32  and the tapped hole  321   a  of the gear shaft  321 . Thus the locking screw  36  is further passed through the tapped hole  32   a  of the gear  32 , the tapped hole  321   a  of the gear shaft  321 , and the tapped hole  23   a  of the pivot shaft  23  so as to fasten the gear  32 , the gear shaft  321 , and the pivot shaft  23  into one part. 
     The clutch  33  is disposed between the support seat  22  of the bench  20  and the gear  32 . The clutch  33  includes a hole  331  arranged axially and penetrating thereof, a first end portion  33   a  at one end and a second end portion  33   b  at the opposite end thereof. Thus the clutch  33  is movably connected to an outer side of the gear shaft  321  of the gear  32  and able to be moved along the longitudinal direction of the gear shaft  321 . The first end portion  33   a  is facing the support seat  22  of the bench  20  while the second end portion  33   b  is facing the gear  32 . The first end portion  33   a  is disposed with at least one projection  332  axially and the support seat  22  of the bench  20  is arranged with at least one slot  222  corresponding to and locked with the projection  332 , as shown in  FIG. 5 . A neck portion  333  whose diameter is smaller than that of the first end portion  33   a  is formed on the second end portion  33   b  of the clutch  33 . A spring  37  is mounted at an outer side of the neck portion  333  while two ends of the spring  37  are elastically against the first end portion  33   a  of the clutch  33  and the side surface of the gear  32  respectively. The gear  32  and the support seat  22  of the bench  20  are connected elastically by the projection  332  of the clutch  33  and the slot  222  of the bench  20  locked with each other and passed through the spring  37 . Thus the clutch  33  is rotated along with the gear  32 . Moreover, the shape of the projection  332  of the clutch  33  is consistent with the shape of the slot  222  of the bench  20 . In order to improve structural strength of the projection  332  of the clutch  33  locked with the slot  222  of the bench  20 , a projection portion  223  is formed on the support seat  22  in relative to the clutch  33  and the slot  222  is formed on the projection portion  223 . 
     The pull member  34  includes a fixing end  341  at one end thereof and an operation end  342  arranged opposite to the fixing end  341 . The fixing end  341  is formed by extension of at least two bars while the gear  32  has at least two through holes  322  corresponding to the bars at the fixing end  341  of the pull member  34 . The bars at the fixing end  341  are movably passed through the through holes  322  of the gear  32  to be fixed on and connected to the first end portion  33   a  of the clutch  33 . The operation end  342  is located at an outer side of the end of the gear  32  without the gear shaft  321  and used for users to pull. Once the pull member  34  is pulled and moved by a user, the clutch is driven to move synchronously. 
     Refer to  FIG. 6 , when the projection  332  of the clutch  33  is engaged with the slot  222  of the support seat  22  of the bench  20 , the motor  31  drives the gear  32  and the clutch to rotate, and further drives the bench  20  to rotate between the horizontal position and the vertical position. 
     Refer to  FIG. 7 , while the projection  332  of the clutch  33  is released from the slot  222  of the support seat  22  of the bench  20 , the bench  20  is unable to be driven by the motor  1  through the rotation of the gear  32  and the clutch  33 . 
     As shown in  FIG. 3 , the driving device  30  further includes a rope  38  having one end thereof to connect to the operation end  342  of the pull member  34  while the other end of the rope  38  is wound around at least one pulley  40  and disposed with a ring  50  which users can grasp. The pulley  40  is set on a pulley support  41  which is fixed on the bench  20 . Moreover, the ring  50  can be hung on a hook  51  that is arranged at the bench  20 . Thereby the user can hold the ring  50  so as to pull the pull member  34  and the clutch  33  to move through the rope  38 . 
     One end of the pivot shaft  23  opposite to the end of the pivot shaft  23  connected to the gear shaft  321  of the gear  32  of the driving device  30  is projecting from the pivot hole  221  of the support seat  22  and is disposed with a stopping portion  231 . The diameter of the stopping portion  231  is larger than that of the pivot hole  221  so that the stopping portion  231  is stopped outside the pivot hole  221  to prevent the pivot shaft  23 , the gear  32  and the gear shaft  321  from moving and hold them in place. 
     As shown in  FIG. 2 , the present invention further includes a buffer  60  arranged between the base  10  and the bench  20 , and fixed on the support frame  11  of the base  10 . When the bench  20  is rotated from the vertical position to the horizontal position, the buffer  60  is in contact with the bottom surface of the bench  20  to prevent the bench  20  from rotating over the normal range. That means the bench  20  is maintained at the horizontal position after it being in contact with the buffer  60 . 
     When the bench  20  is located at the vertical position while the power is gone or the driving motor fails, the user can pull the operation end  342  of the pull member  34  outward to drive the clutch  33  moving outward, toward the gear  32 . Thus the projection  332  of the clutch  33  and the slot  222  of the support seat  22  of the bench  20  are separated from each other and the spring  37  is compressed. Now the user can drive the bench  20  to move from the vertical position to the horizontal position by the body weight. Then the pull member  34  is released and the clutch  33  is moved inward by the elastic recovery force of the spring  37 . The projection  332  of the clutch  33  is locked into the slot  222  of the support seat  22  of the bench  20  again. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, and representative devices shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.