Patent ID: 6256812
Filing Date: 2001-07-10
Classification: A61G

Abstract:
A wheeled carriage for supporting a patient in a substantially horizontal position, said wheeled carriage having a center of gravity and a force F.sub.mass at the center of gravity due to the mass of said carriage or the mass of a combination of said carriage and a patient thereon, said wheeled carriage comprising:a patient support having a length, opposing ends of the length comprising a head end and a foot end of said patient support, said patient support having a pair of lateral sides intermediate the head and foot ends;a wheeled base having a length and supporting said patient support and enabling movement of said patient support, said wheeled base including at least four floor surface engaging and castered wheels spaced from one another, said wheeled base of said wheeled carriage having a first edge at a first end corresponding to the head end of said patient support and a second edge at a second end corresponding to the foot end of said patient support;a gripping location at the head end of said patient support, said gripping location being utilized to apply a force F.sub.max to said carriage sufficient to overcome friction and move said wheeled carriage;an auxiliary wheel mechanism including an auxiliary wheel support structure for rotatably supporting at least one auxiliary wheel at an axis thereof to said wheeled base, said at least one auxiliary wheel being uncastered, the axis of said at least one auxiliary wheel being secured to said wheeled base at a distance L in a horizontal direction from the center of gravity along the length of said wheeled base when said auxiliary wheel is engaged with the floor surface, a moment M.sub.mass being defined by the distance L multiplied by the force F.sub.mass ; andcontrol apparatus for effecting a movement of said support structure and said at least one auxiliary wheel between a first position whereat said auxiliary wheel is engaged with the floor surface and a second position whereat said auxiliary wheel is out of engagement with the floor surface,wherein, when said auxiliary wheel is in engagement with the floor surface, the height H defined by the axis of said auxiliary wheel and the relative height of said gripping location creates a moment M.sub.force defined by multiplying the height H by the force F.sub.max,the distance L being great enough such that the moment M.sub.mass is greater than the moment M.sub.force when any size and weight of patient is placed on the patient support having their head toward the head end thereof, such that said wheeled carriage does not teeter between said castered wheels on respective ends of said carriage during movement thereof.