Low-profile electric bed

Abstract

A low-profile electric bed includes a stationary frame, an upper frame pivotally connected with the stationary frame and provided with two slide connecting portions, a push frame having a swivel rack pivotally connected with the stationary frame and two moving arms pivotally connected with swivel rack, and an actuator having two ends pivotally connected with the stationary frame and the upper frame, respectively. The actuator is arranged in a way that when the actuator extends, the upper frame is driven to upward swing relative to the stationary frame. As a result, the low-profile electric bed may have a reduced thickness to minimize packing volume thereof while maintaining a normal function.

What is claimed is: 
     
         1 . A low-profile electric bed, comprising:
 a stationary frame;   an upper frame having a side pivotally connected with the stationary frame, and two slide connecting portions;   a push frame comprising a swivel rack and two moving arms; wherein the swivel rack includes a connecting rod and two support arms disposed with two ends of the connecting rod; wherein each of the two support arms is pivotally connected with the stationary frame via a first pivot, pivotally connected with one of the two moving arms via a second pivot, and pivotally connected with a push wheel via a third pivot in a way that the third pivot is located between the first pivot and the second pivot, and the first, second and third pivots are located at three vertices of a triangle respectively; wherein each of the two support arms has a stopping portion configured in a way that when each of the two moving arms is rotated relative to associated one of the two support arms at a predetermined angle, the each of the two moving arms is stopped at the stopping portion of the associated one of the two support arms to prevent the each of the two moving arms from further rotation; wherein each of the two moving arms is pivotally connected with a roller via a fourth pivot; and   an actuator having two ends pivotally and respectively connected with the stationary frame and the swivel rack in a way that when the actuator gradually extends at a first stage, the two push wheels are in contact with the two slide connecting portions respectively, causing the swivel rack to swing about the first pivot and to drive the upper frame to upward swing relative to the stationary frame, and when the actuator further extends at a second stage, the two moving arms are respectively engaged with the two stopping portions, causing that the two rollers are in contact with the two slide connecting portions respectively, and the swivel rack and the two moving arms collectively swing about the first pivot in a way that the two push wheels are disengaged from the two slide connecting portions, and the swivel rack and the two moving arms collectively drive the upper frame to upward further swing relative to the stationary frame.   
     
     
         2 . The low-profile electric bed as claimed on  claim 1 , wherein one of the two ends of the actuator is pivotally connected with the connecting rod of the swivel rack; each of the two ends of the connecting rod is located between one of the two first pivots and one of the two third pivots. 
     
     
         3 . The low-profile electric bed as claimed in  claim 1 , wherein when the upper frame is parallel to the stationary frame, a distance between the third pivot and the slide connecting portion is less than a distance between the first pivot and the slide connecting portion and less than a distance between the second pivot and the slide connecting portion. 
     
     
         4 . The low-profile electric bed as claimed in  claim 1 , wherein the first pivot and the third pivot are situated on a first imaginary surface, and the second pivot and the third pivot are situated on a second imaginary surface that is defined with the first imaginary surface an included angle ranging from 150° to 170°. 
     
     
         5 . The low-profile electric bed as claimed in  claim 4 , wherein when the moving arm is stopped by the stopping portion, the fourth pivot is situated on the second imaginary surface.