Latching system for adjustable motorized hospital bed

An adjustable bed comprising:

• a movable frame having head and foot ends and being capable of moving from a generally horizontal position in which the head and foot ends of the frame are generally in lowermost positions to other and higher elevated positions in which the frame may be horizontal or inclined such that the head end is above the foot end or vice-versa;
• head elevating means for supporting the head end of the frame and being movable relative to the frame to change elevation of the head end, the head elevating means including a rotatable element which when turned normally effects a change in the elevation of the head end of the frame;
• foot elevating means for supporting the foot end of the frame and being movable relative to the frame to change the elevation of the foot end, the foot elevating means including a rotatable element which when turned normally effects a change in the elevation of the foot end of the frame;
• an electric motor mounted on the frame and being capable of operating in both directions of rotation;
• electrically operated head and foot clutch means for engaging the motor with the rotatable elements of the head and foot elevating means, respectively, such that the motor turns those elements, the clutch means being operable independently or simultaneously and when operated simultaneously causing the rotatable elements to revolve such that the head and foot ends of the frame undergo the same direction of elevational movement;
• and a control circuit including:
• a down switch, a head limit switch which senses when the head end of the frame is in its lowermost position and a foot limit switch which senses when the foot end of the frame is in its lowermost position, and latching means connected to the down switch and to the limit switches for, when the down switch is actuated even momentarily, operating the clutch means such that they engage the motor with rotatable elements, for also at that time energizing the motor in the direction which causes the rotatable elements to lower the frame at both of its ends, for further keeping each of the clutches so engaged until, at least until one end of the frame reaches its lowermost position, and for keeping the motor energized until both of the limit switches sense that their respective ends of the frame are in their lowermost positions.

An adjustable bed comprising:

• a movable frame having head and foot ends and being capable of moving from a generally horizontal position in which the head and foot ends of the frame are generally in lowermost positions to other and higher elevated positions in which the frame may be horizontal or inclined such that the head end is above the foot end or vice-versa;
• head elevating means for supporting the head end of the frame and being movable relative to the frame to change elevation of the head end, the head elevating means including a rotatable drive screw, a nut which normally travels along the screw when the screw is turned to effect a change in the elevation of the head end of the frame, and means for allowing the screw to rotate without causing a further movement of the nut along the screw when the head end of the frame reaches its lowermost position;
• foot elevating means for supporting the foot end of the frame and being movable relative to the frame to change the elevation of the foot end, the foot elevating means including a rotatable drive screw, a nut which normally travels along the screw when the screw is turned to effect a change in the elevation of the foot end of the frame, and means for allowing the screw to rotate without a further movement of the nut along the screw when the foot end of the frame reaches its lowermost position;
• an electric motor capable of operating in both directions of rotation;
• electrically operated head and foot clutch means for engaging the motor with the rotatable drive screws of the head and foot elevating means, respectively, such that the motor turns those screws, the clutch means being operable independently or simultaneously and when operated simultaneously causing the drive screws to revolve such that the head and foot ends of the frame undergo the same direction of elevational movement;
• and a control circuit including;
• a down switch, a head limit switch which senses when the head end of the frame is in its lowermost position and a foot limit switch which senses when the foot end of the frame is in its lowermost position, and latching means connected to the down switch is actuated even momentarily, operating the clutch means such that they engage the motor with the two drive screws, for also at that time energizing the motor in the direction which causes the drive screws to lower the frame at both of its ends, and for further keeping each of the clutches so engaged until both of the limit switches sense that their respective ends of the frame are in their lowermost positions, whereby the drive screw for the end of the frame which reaches its lowermost position first will after reaching that position continue to rotate, without effecting a further descent of its end of the frame, until both ends of the frame reach their lowermost positions.