Powered Ambulance Stretcher Product

Overview

A powered ambulance stretcher replaces the manual lifting that historically caused more career-ending injuries to paramedics than any other task. Back injury is the leading cause of early retirement in EMS; a crew that lifts a 100 kg patient plus a 40 kg cot a dozen times per shift accumulates spinal load that no technique fully mitigates. The powered cot moves that load to a battery and an actuator: the crew steers and the machine lifts, up to a rated 318 kg.

The architecture is an X-frame scissor: the Litter Platform patient platform rides on crossed legs over the Wheeled Base, and the Powered Lift Frame actuator changes the scissor angle to set any height between about 36 cm (bed transfer) and 105 cm (working height).

Lift mechanism

The two X-Frame Leg weldments pivot on a hardened Pivot Pin Set and Ball Bearing joints, tied square by Cross Brace tubes so an off-center patient cannot rack the frame. The Lift Actuator is electro-hydraulic: a 24 V Actuator Motor drives a small pump through a Helical Gear Pair reduction, pressurizing the Hydraulic Cylinder that spreads the scissor. A Hall Sensor reports position to the controls. Hydraulics were chosen over a pure ball-screw drive for two properties: the cylinder holds load with zero power draw, and a manual release valve lets the crew lower the cot smoothly with a dead battery — the failure mode is always "becomes a manual cot," never "stuck."

Control is from a sealed Hand Control at either end. The Control Board's Microcontroller ramps the motor through a Power MOSFET bridge, enforces current limits that correspond to the load rating, and meters battery state. Power is a tool-free swappable Battery Pack — twelve Li-ion Cell, 18650 cells and a BMS Board in a latching Battery Shell — good for roughly 30 full lift cycles; the Charge Port contacts also charge the installed pack from an ambulance dock during transport.

Mobility and loading

The Wheeled Base rolls on four 200 mm Swivel Caster units whose solid Caster Wheel tires cross gravel, thresholds, and curb cuts without inflation or puncture concerns. A foot-operated Brake Linkage holds the cot on slopes, and the Steer Lock fixes one caster straight so a loaded cot tracks straight down a corridor instead of crabbing.

Loading into the ambulance uses the Loading System. The cot is raised to floor height, its head-end Load Wheel pair rolls onto the deck, and the attendant squeezes the Leg Release Trigger triggers so the legs fold as the cot slides in. The Safety Bar hooks the floor edge throughout, so a mistimed release cannot drop the patient. Inside, the Latch Hook engages a crash-rated floor fastener; with a powered loading arm, the same hook mates to the trolley and the system lifts the entire cot-plus-patient weight, taking even the loading push off the crew. Cot, fastener, and restraints together are what carry the SAE J3027 / EN 1789 crash rating.

Patient platform

The Litter Frame carries a fluid-proof Mattress with welded seams for decontamination between calls. The Backrest Section raises to about 75° with Gas Spring assist for respiratory positioning; the Foot Section articulates for shock posture. Folding Siderail rails lock up via Rail Latch catches, and the Restraint System set — Shoulder Harness, Lap Belt, and Leg Strap on quick-release Buckle Set hardware — restrains the patient against transport accelerations. An IV Pole and Equipment Hook mounts let infusions and the oxygen bottle travel with the patient, and telescoping Push Handle grips give attendants leverage at proper working height.

Service considerations

Wear concentrates in predictable places: the pivot bushings, caster bearings, and battery packs are scheduled-replacement items, and the actuator is sealed for life and swapped as a unit. Agencies typically rotate two packs per cot through wall chargers. The 57 kg empty weight is the design's main tradeoff — roughly 17 kg heavier than a manual cot — which the loading system exists to neutralize.