Leveling system

Claim 2

In a system including a vehicle adapted to move substantially parallel to a fixed platform, apparatus for vertically aligning the floor of said vehicle with the floor of said platform comprising a. reflective means of finite width positioned on the side of said fixed platform at a predetermined distance from the floor of said platform and substantially parallel to the track of said vehicle, b. an optical source mounted on the side of said vehicle facing said platform and positioned at substantially an equal predetermined distance from the floor of said vehicle, c. a pair of detectors sensitive to the wavelength of said optical source mounted on the side of said vehicle facing said platform, said detectors being substantially vertically arranged with respect to each other and separated by a distance not greater than said finite width of said reflective means, the upper one of said detectors being positioned on said vehicle at a distance from the floor thereof which is at least as great as the distance from the floor of said platform to the top of said reflective means, d. means for moving the floor of said vehicle vertically, and e. circuit means responsive to the signals generated by said detectors and operative to activate said means for moving the floor of said vehicle vertically.

Claim 3

Apparatus as defined in claim 1 wherein said vehicle includes a pneumatic suspension system and said means for moving the floor of said vehicle vertically includes a. a source of pressurized air in fluid communication with said pneumatic suspension system through a first normally closed valve, b. vent means for releasing air from said pneumatic suspension system through a second normally closed valve, and c. logic means responsive to the difference in signals generated by said detectors and operative to open said first normally closed valve only when the signal generated by the upper one of said detectors is greater than the signal generated by the lower one of said detectors, and to open said second normally closed valve only when the signal generated by the lower one of said detectors is greater than the signal generated by the upper one of said detectors.

Claim 4

Apparatus as defined in claim 2 wherein said logic means includes first and second NAND gates operatively controlling first and second power switches, respectively, the output of said upper detector operatively connected to an input of said first NAND gate and also connected with an input of said second NAND gate through an inverter; the output of said lower sensor operatively connected with an input of said second NAND gate and also connected with an input of said first NAND gate through an inverter.

Claim 5

Apparatus as defined in claim 1 including means for activating said circuit means only when said vehicle is in the immediate vicinity of said platform.

Claim 6

Apparatus as defined in claim 4 Wherein said vehicle includes a pneumatic suspension system and roll control apparatus automatically adjusting pneumatic suspension pressure to avoid roll-induced sway, said apparatus including means for operatively disabling said roll control apparatus simultaneously with activation of said circuit means responsive to the signals generated by said detectors.

Claim 7

Apparatus as defined in claim 1 wherein said vehicle includes a pneumatic suspension system supporting the vehicle body over a pair of axles and said means for moving the floor of said vehicle comprising valves responsive to said circuit means for varying the volume of air in said pneumatic suspension system.

Claim 8

The apparatus defined in claim 1 wherein said circuit means includes a logic network responsive only to the difference in signals generated by said pair of detectors.

Claim 9

The apparatus defined in claim 7 wherein said logic network comprises a NAND gate operatively interconnected with the output of each of said detectors, each gate being operatively connected with a power switch and interconnected with each other to turn on the respective power switch connected therewith only when the signal received from the detector connected therewith is greater than the signal received by the other gate from the other detector.

Claim 10

In a system including a wheeled vehicle having a floor supported between front and rear axles by a pneumatic suspension system and adapted to move along a course substantially parallel to a fixed platform; apparatus for vertically aligning the floor of said vehicle with the floor of said platform comprising a. reflective means of finite width positioned on the side of said fixed platform at a predetermined distance from the floor of said platform and substantially parallel to the course of said vehicle, b. means for reflecting optical energy from said reflective means substantially horizontally across the path of said vehicle, c. first upper and lower sensors mounted on said vehicle near the front thereof and aligned to detect optical energy transmitted across the path of said vehicle, the upper sensor being positioned on said vehicle at a vertical distance from the floor thereof which is at least as great as said predetermined distance and vertically separated from said lower sensor by a distance not greater than said finite width of said reflective means, d. means for selectively injecting and releasing air from the front and rear pneumatic suspension systems whereby the height of the front and rear of said vehicle may be varied, e. circuit means responsive to the difference in signals generated by said first upper and lower sensors and operative to control said means for selectively injecting and releasing air from said front pneumatic system, f. second upper and lower sensors mounted on said vehicle near the rear thereof and aligned to detect optical energy transmitted across the path of said vehicle, the upper sensor being positioned on said vehicle at a vertical distance from the floor thereof which is at least as great as said predetermined distance and vertically separated from said lower sensor by a distance not greater than said finite width of said reflective means, and g. circuit means responsive to the difference in signals generated by said second upper and lower sensors and operative to control said means for selectively injecting and releasing air from said rear pneumatic suspension.

Claim 11

In a system including a wheeled vehicle having a floor supported between front and rear axles by a pneumatic suspension system and adapted to move along a course substantially parallel to a fixed platform; apparatus for vertically aligning the floor of said vehicle with the floor of said platform comprising a. reflective means of finite width positioned on the side of said fixed platform at a predetermined distance from the floor of said platform and substantially parallel to the course of said vehicle, b. means for reflecting optical energy from said reflective means substantially horizontally across the path of said vehicle, c. first upper and lower sensors mounted on said vehicle near the front thereof and aligned to detect optical energy transmitted across the path of said vehicle, the upper sensor being positioned on said vehicle at a vertical distance from the floor thereof which is at least as great as said predetermined distance and vertically separated from said lower sensor by a distance not greater than said finite width of said reflective means, d. means for selectively injecting and releasing air from the front and rear pneumatic suspension systems whereby the height of the front and rear of said vehicle may be varied, e. circuit means responsive to the difference in signals generated by said first upper and lower sensors and operative to control said means for selectively injecting and releasing air from said front pneumatic system, f. second upper and lower sensors mounted on said vehicle near the rear thereof and aligned to detect optical energy transmitted across the path of said vehicle, the upper sensor being positioned on said vehicle at a vertical distance from the floor thereof which is at least as great as said predetermined distance and vertically separated from said lower sensor by a distance not greater than said finite width of said reflective means, and g. circuit means responsive to the difference in signals generated by said second upper and lower sensors and operative to control said means for selectively injecting and releasing air from said rear pneumatic suspension.