A hydraulic drive unit for a stretcher has a hydraulic circuit with a differential cylinder, a pump, a tank and a valve assembly. The differential cylinder includes a rod working chamber and a piston working chamber. The valve assembly is switchable into at least a first state and a second state, wherein the rod working chamber is connected to the tank in the first state and to the pump in the second state, and wherein the piston working chamber is connected to the pump in the first state and to the tank in the second state. The tank is a tank separated from the atmosphere with a variable tank volume, so that the hydraulic circuit is configured as a closed hydraulic circuit. A stretcher having such a hydraulic drive unit is also provided.

A deployable gurney lift assembly (12), which has a carriage assembly (14) plate (20) with two pivot arms (38) disposed opposite one another on each side of the carriage assembly (14), an antler holder (16) to accommodate a bar of the gurney, and at least one hydraulic, pneumatic, or electric jack (22) lift actuator for lifting and lowering the arms (38). Retractable deployment apparatus for slidably moving the retractable deployment apparatus along a length of base tracks (28). Base tracks (28) having rear ends terminating in stops (42), and carriage assembly (14) guides slidably engaged along deployment tracks (28).

The embodiments described and claimed herein are a restraint system for securing a wheeled mobility device and its occupant in a vehicle. In one embodiment, occupant restraints and an anchor point are provided. The occupant restraints are connected directly to the anchor point, while the anchor point is on a frame of the wheeled mobility device and is adapted for connection to the vehicle for securing the wheeled mobility device and its occupant to the vehicle. With this configuration, occupant loads during an accident will bypass the gurney and occupant head excursions can be reduced.

An apparatus includes a hydraulic circuit that is configured to selectively open fluid communication between one portion of the hydraulic circuit and another portion of the hydraulic circuit, such as a reservoir, based on the flow of the hydraulic fluid in the one portion. When the flow of hydraulic fluid exceeds a selected threshold in the one portion of the hydraulic circuit, the flow of fluid urges the opening of a hydraulic component of the hydraulic circuit to allow fluid communication between the one portion and the reservoir to discharge fluid from the one portion.

A strain gauge assembly includes a member and a strain gauge supported by the member spaced. The strain gauge further includes a bearing surface and a contact surface spaced from the bearing surface. When the member is subject to a predetermined bending force, the bearing surface contacts the contact surface wherein at least a portion of the bending force bypasses the strain gauge and instead is transferred from the bearing surface to the contact surface.

A hydraulic system for a mobile rescue stretcher has a hydraulic cylinder, with first and second working chambers, a tank and pump. The first and second chambers are connected to the pump via first and second line arrangements, respectively, and can be pressurized by the pump. Hydraulic fluid flows out of the first chamber via the first line arrangement when pressure is applied to the second chamber. The first line arrangement has a first check valve which opens when pressure is applied to the second line arrangement. Hydraulic fluid flows out of the second chamber via the second line arrangement when pressure is applied to the first chamber. The second line arrangement has a first branch line connected to the pump and a second branch line connected to the tank. A pressure valve in the second branch line opens when pressure is applied to the second line arrangement.

A patient support apparatus comprises a support structure comprising a base and a patient support surface to support a patient. An actuator system facilitates movement of the patient support surface relative to a floor surface. One or more sensors are responsive to changes in position of the patient support surface caused by the actuator system. A controller is operably coupled to the one or more sensors and the actuator system. The controller is configured to operate the actuator system to move the patient support surface and to monitor the movement of the patient support surface by sensing positions of the patient support surface over time. The controller is further configured to identify a frictional load event on the actuator system during movement in a present cycle and associate the frictional load event with a sensed position of the patient support surface in the present cycle.

The embodiments described and claimed herein are a restraint system for securing a wheeled mobility device in a vehicle. In one embodiment, at least one restraint includes a hand-releasable connection to the vehicle. In other embodiments, the hand releasable connection is formed by a set of mounting details, where the mounting details include a headed stud received in a slot. In yet other embodiments, the hand releasable connection can be formed by a spring loaded locking pin that engages with a bore. In even further embodiments, the headed stud and spring loaded locking pin are coupled to the restraint, while the slot and bore are coupled to the floor of the vehicle.

A hydraulic system for a mobile rescue stretcher has a hydraulic cylinder, with first and second working chambers, a tank and pump. The first and second chambers are connected to the pump via first and second line arrangements, respectively, and can be pressurized by the pump. Hydraulic fluid flows out of the first chamber via the first line arrangement when pressure is applied to the second chamber. The first line arrangement has a first check valve which opens when pressure is applied to the second line arrangement. Hydraulic fluid flows out of the second chamber via the second line arrangement when pressure is applied to the first chamber. The second line arrangement has a first branch line connected to the pump and a second branch line connected to the tank. A pressure valve in the second branch line opens when pressure is applied to the second line arrangement.

A patient transport apparatus for use with a vehicle, comprising a lift mechanism between a base and a support frame to move between an extended configuration defining a first distance and a retracted configuration defining a second distance. An interface generates a user signal. A sensor generates a sensor signal corresponding to force acting on the base relative to the support frame. A controller determines if the user signal corresponds to an extend or retract command; determines if the force acting on the base has exceeded a predetermined threshold value based on the sensor signal; drives the lift mechanism toward the extended configuration where the user signal corresponds to the extend command and toward the retracted configuration where the user signal corresponds to the retract command; and interrupts driving the lift mechanism to stop motion of the lift mechanism in response to the sensor signal exceeding the predetermined threshold value.