Hottinger Baldwin Measurements Inc.

Hill-Rom Services, Inc.

Hbm, Inc.

Randall K Hopkins

Thomas W Hansson

Steve A Dixon

Donald L Mobley

A patient support including a mattress, a load cell apparatus, and a frame having an intermediate frame and a weigh frame. The load cell apparatus is positioned relative to the intermediate frame and the weigh frame. The load cell apparatus includes a load cell, a mount, and a liner.

Load cell apparatus

A load cell includes a strain gage on a narrow sensing section of a beam element, on a planar outer surface facing outwardly from the median plane extending longitudinally through the cell. A cup-shaped seal cap enclosing the strain gage is laser welded onto the outer surface of the beam element to form a hermetic seal. A wiring tunnel in the load cell body leads from inside the seal cap into an electronics cavity for wires to pass from the strain gage to electronic circuitry. The load cell body and seal caps, made of stainless steel or titanium, are hermetically sealed for use in harsh environments. The seal caps have a minimal influence on strain in the sensing sections. The load cell has a low-end capacity of 5 kg or less.

Hermetically sealed load cell

A tank weigh module includes a bottom plate that has two lower stop blocks protruding upwardly therefrom, and a top plate that has an upper stop block protruding downwardly therefrom into a space between the two upper stop blocks with a block free play clearance therebetween. A restraining pin is arranged to extend through aligned pin receiving holes in all of the stop blocks. In the lower stop blocks, the holes provide a tight friction fit for the pin, while the hole in the upper stop block has a larger diameter and provides a pin free play clearance. Motion of the top plate relative to the bottom plate in the back-and-forth Y-direction is limited to the extent of the block free play clearance. Travel of the top plate in the side-to-side X-direction and in the uplift Z-direction is restrained by the extent of the pin free play clearance. Tilting and twisting about the X-, Y-, and Z-axes are also limited by the pin interacting with the blocks and the blocks interacting with each other. A load cell is secured in position between the top and bottom plates by two fixed securing pins and a third removable securing pin attached to the bottom plate, whereby the securing pins are angularly offset by 120&deg; from each other. The weigh module has a simple construction, installation, and servicing, and provides protection against excess uplift, side loading, and tilting while allow complete free floating operation in a normal operating range.

Tank weigh module with excess motion restraint

A load to be measured is transmitted to a load cell, such as a compression load cell, through a double piston, single cylinder load transmitter that has a pressure chamber between two pistons in the single cylinder. One piston bears against the load. The other piston bears against the load cell to form a floating link between the load and the load cell when a sufficient pressure is introduced into said pressure chamber to prevent unwanted, off-center load application force components from adversely affecting any measured results. Preferably, at least one axially outwardly facing end surface of the piston bearing against the load cell has a curved end surface area. A rocker pin with a pressure controllable variable length may be formed by making both axially outwardly facing end surfaces curved. Several load transmitters may be arranged in parallel to transmit larger loads into a load cell.

Growing community of inventors

Mendon, MA, United States of America

Randall K Hopkins