# US 11,440,476 B2 · Extendable/retractable step assembly for a rear assembly of a flatbed trailer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,476 B2 - Document ID: US11440476B2 - Status: Granted - Kind: B2 - Application number: 16/876,696 - Filed: 2020-05-18 - Published: 2021-06-17 - Granted: 2022-09-13 - Earliest claimed: 2019-12-17 - Applicants: Miles A. Reitnouer - Inventors: Miles A. Reitnouer - Web page: https://patentgrep.com/patent/US11440476B2 ## CPC - B60R 3/02: Retractable steps {or ladders, e.g. movable under shock (B60R3/005 takes precedence)} - B60T 13/263: {specially adapted for coupling with dependent systems, e.g. tractor-trailer systems} - B60T 17/22: Devices for monitoring or checking brake systems; Signal devices - B62D 21/20: trailer type, i.e. a frame specifically constructed for use in a non-powered vehicle - B60T 7/20: specially for trailers, e.g. in case of uncoupling of {or overrunning by} trailer (inertia-actuated overrun brakes B60T13/08) - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR - B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) ## Abstract An extendable/retractable step assembly mounted at the rear assembly of a flatbed trailer to permit access to and from the ground to the flatbed trailer. The extendable/retractable stair assembly includes a pair of steps that are staggered and can be extended out of the rear assembly during use and then retracted therein when not in use. The steps can be manually extended/retracted or they can be automatically controlled. A safety interlock is also disclosed to automatically retract the steps when the trailer emergency brakes are released. ## Claims ### Claim 1 An apparatus for extending and retracting steps at the rear assembly of a flatbed trailer, said apparatus comprising: an upper step and a lower step that can extend or retract through the rear assembly and wherein said lower step protrudes out farther from the rear assembly than does said upper step when said steps are extended in order to form a staggered pair of steps; each step being coupled to a linkage assembly that extends or retracts said upper and lower steps together, each step extending and retracting through a respective aperture in the rear assembly of the flatbed trailer; and an automatic control system for automatically extending and retracting said upper and lower steps, said automatic control system comprising a switch coupled between an air brake system of the flatbed trailer and a pneumatic actuator connected to said linkage assembly, said switch being controllable to allow an operator to extend said steps and to retract said steps. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein each step comprises a rail on each side of said step, each of said rails sliding on a guide secured to said housing to maintain an alignment of each of said steps, each of said rails being horizontal when said steps are extended and retracted. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein said automatic control system further comprises a regulator installed between said switch and said pneumatic actuator for controlling the speed at which said steps are extended and retracted. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein said pneumatic actuator comprises a service chamber. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein said switch is an auto reset valve. ### Claim 6 (depends on 1) The apparatus of claim 1 wherein said automatic control system further comprises an override path for automatically retracting said steps whenever the operator fails to retract said steps with said switch and the emergency brakes of the flatbed trailer are released. ### Claim 7 (depends on 6) The apparatus of claim 6 wherein said override path comprises a pneumatic connection between said switch and an air brake line coupled to a glad-hand of the flatbed trailer. ### Claim 8 (depends on 1) The apparatus of claim 1 wherein said switch operates to extend said steps when air pressure is passed through said switch to said pneumatic actuator and operates to retract said steps when said switch blocks air pressure to said pneumatic actuator.