Pressure based load sensing system
AssigneeJLG Industries, Inc.
InventorsLouis A. BAFILE, James N. SMYLY, Aaron A. POWERS, Brendan KOTLANGER
Life of this patent
Estimating the term…
Abstract
A load sensing system measures lift cylinder pressure and platform height to estimate platform load. The system functions to prevent overload and is designed to comply with regulatory requirements. The system provides the advantages of a force-based approach using simple, lower cost pressure-based measurement components.
Claims16
A platform load sensing system for detecting an overload condition on a liftable platform, the platform being raised and lowered on a lift arm using a hydraulic lift cylinder including a head end and a rod end, the platform load sensing system comprising:
- a head end pressure transducer positioned at the head end that is configured to measure head end pressure in the hydraulic lift cylinder;
- a rod end pressure transducer positioned at the rod end that is configured to measure rod end pressure in the hydraulic lift cylinder;
- a main rotary angle sensor that is configured to measure a lift arm angle;
- and
- control circuitry communicating with and receiving input from the head end pressure transducer, the rod end pressure transducer, and the main rotary angle sensor, wherein the control circuitry is programmed to calculate a platform height based on the lift arm angle and to calculate a platform load based on the input from the head end pressure transducer, the input from the rod end pressure transducer, and the platform height,
- wherein the control circuitry is programmed to indicate the overload condition when the platform load exceeds a predefined load.
A method of detecting an overload condition on a liftable platform, the platform being raised and lowered on a lift arm using a hydraulic lift cylinder including a head end and a rod end, the method comprising:
- (a) measuring head end pressure in the hydraulic lift cylinder;
- (b) measuring rod end pressure in the hydraulic lift cylinder;
- (c) measuring a lift arm angle;
- (d) determining a platform height from the lift arm angle;
- (e) determining a platform load based on the input from the head end pressure transducer, the input from the rod end pressure transducer, and the platform height;
- and
- (f) indicating the overload condition when the platform load exceeds a predefined load.
Dependencies are inferred from the claim text.