Moving bed assembly

Abstract

A moving bed assembly includes a bed frame supported over a base frame by pivoting swing arms and driven in a controlled motion by a motor-driven shaft and drive arms. A protective barrier is mounted to the base frame to restrict access to moving components, and an electrical interlock disables the motor when the barrier is removed or displaced. The assembly also includes a crush detection system positioned along a perimeter of the bed frame or base frame. The crush detection system uses a compressible sensor tube containing a light emitter and a light sensor arranged to detect a transmitted light signal, with compression disrupting the signal and causing a controller to disable the motor until the obstruction is cleared and the system reset. The features provide controlled bed motion with enhanced safety.

What is claimed is: 
     
         1 . A moving bed assembly comprising: 
 a base frame;   a bed frame arranged over the base frame;   at least first and second pairs of swing arms pivotably connecting the bed frame to the base frame;   a drive shaft mounted to the base frame and carrying first and second cranks at opposite ends;   first and second drive arms respectively connected between the cranks and corresponding ones of the swing arms;   a motor driving the drive shaft;   a protective barrier mounted to the base frame and positioned to inhibit access to the motor, the drive shaft, or the swing arms; and   a crush detection system including a compressible sensor tube mounted along a perimeter of the bed frame or the base frame, the tube containing a light emitter and a light sensor arranged to detect a transmitted light signal, compression of the tube disrupting the light signal and causing the motor to be disabled.   
     
     
         2 . The assembly of  claim 1 , wherein the protective barrier includes an electrical interlock configured to disable the motor when the barrier is removed or displaced. 
     
     
         3 . The assembly of  claim 2 , wherein operation of the motor is restored by re-establishing the interlock and resetting a controller. 
     
     
         4 . The assembly of  claim 1 , wherein the compressible sensor tube is mounted along a perimeter of the bed frame. 
     
     
         5 . The assembly of  claim 1 , wherein the compressible sensor tube is mounted along a perimeter of the base frame. 
     
     
         6 . The assembly of  claim 1 , wherein the motor remains disabled until the light signal is restored and a reset command is received. 
     
     
         7 . The assembly of  claim 1 , further comprising a shaft brake engaging the drive shaft. 
     
     
         8 . The assembly of  claim 7 , wherein a braking force of the shaft brake is adjustable. 
     
     
         9 . The assembly of  claim 1 , further comprising a transmission through which the motor drives the drive shaft. 
     
     
         10 . The assembly of  claim 9 , wherein axes of rotation of the motor and the drive shaft are perpendicular. 
     
     
         11 . The assembly of  claim 1 , wherein the bed frame supports an articulated mattress platform. 
     
     
         12 . A safety system for a moving bed assembly comprising: 
 a protective barrier mounted to a frame of the moving bed assembly;   an electrical interlock associated with the protective barrier and forming part of a safety circuit; and   a controller configured to disable a motor of the moving bed assembly when the safety circuit is interrupted.   
     
     
         13 . The system of  claim 12 , wherein the interlock comprises a plug-and-receptacle connector. 
     
     
         14 . The system of  claim 12 , wherein restoration of motor operation requires closure of the safety circuit and activation of a reset input. 
     
     
         15 . The system of  claim 12 , wherein the protective barrier is configured to enclose at least the motor, the drive shaft, or a swing arm of the moving bed assembly. 
     
     
         16 . A crush detection system for a moving bed assembly, comprising: 
 a compressible sensor tube mounted along a perimeter of the moving bed assembly;   a light emitter arranged to transmit a light signal through the tube;   a light sensor arranged to detect the light signal; and   a control circuit configured to disable a motor of the moving bed assembly when compression of the sensor tube disrupts the detected light signal.   
     
     
         17 . The system of  claim 16 , wherein the sensor tube comprises a soft elastomeric material. 
     
     
         18 . The system of  claim 16 , wherein the sensor tube is mounted to a perimeter of the bed frame. 
     
     
         19 . The system of  claim 16 , wherein the sensor tube is mounted to a perimeter of the base frame. 
     
     
         20 . The system of  claim 16 , wherein the motor remains disabled until the light signal is restored and the control circuit is reset.