Adjustable hospital bed instantly movable to a trendelenburg position

Claim 1

An adjustable hospital bed having articulated head and foot elevation linkage systems for vertically moving an upper horizontal frame with respect to a fixed lower horizontal frame while at the same time maintaining the frames substantially parallel to each other, comprising: an extendible segment in said foot linkage system for effecting a greater separation between the frames at their foot ends than at their head ends and including a pair of straight elongated links, one of which is slidably and rectilinearly movable in the other, positioned such that their longitudinal axes are generally vertical and substantially perpendicular to the upper frame at all times, the top end of said other link being pivotally connected to the upper frame while the bottom end of said one link is pivotally connected to another segment of the articulated foot linkage system; and control means for establishing said extendible segment selectively in non-extended and extended conditions, the upper frame remaining horizontal regardless of its Vertical position when said extendible segment is in its non-extended condition, whereas when said extendible segment is in its extended condition the upper frame is tilted to a trendelenburg position with its foot end raised relative to its head end.