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This is a record of a document published elsewhere, first published by the United States Patent and Trademark Office, as US-5673491-A, on 7 October 1997. OpenTechnical did not first disclose it. The identifier, hashes and timestamps below record what this library served and when, not when the material became public. View the original.

OT-2026-000003240

Crane level indicator device

Published
Permanent URL
Classification
Lifting, Positioning & Manipulation › Hoists and Cranes
Original source
US-5673491-A, the United States Patent and Trademark Office, 7 October 1997
Document SHA-256
7dfedade939c91fa1caf40e0d3bc37c91b1a292db296f77447281023a4d14c4a

Disclosed is a level indicator device for cranes. A sensor sending unit fixed to the crane base utilizes a free swinging pendulum with a tip which activates sensor portions on a sensor board. An out-of-level attitude of the crane tilts the sensor sending unit and thus moves the pendulum tip to contact a specific sensor portion defined by the crane attitude. The sensors are connected to circuitry including a programmable array logic chip which generates a signal representative of a binary number corresponding to the position of the particular sensor activated. A serial to parallel converter converts the parallel binary number to a serial number and transmits radio frequency signals with said serial binary number indicative of the pendulum position. The RF signal is received by a receiver indicator unit located in the operator control station of the crane. Circuitry converts the signals to indicator activating signals for an indicator panel on the receiver indicator unit. The indicator panel displays the direction and degree of tilt of the crane base by appropriately positioned visual indicators laid out in quadrants to incrementally indicate the degree and direction of the crane tilt whereby the crane operator may operate the crane leveling controls.

Abstract

Disclosed is a level indicator device for cranes. A sensor sending unit fixed to the crane base utilizes a free swinging pendulum with a tip which activates sensor portions on a sensor board. An out-of-level attitude of the crane tilts the sensor sending unit and thus moves the pendulum tip to contact a specific sensor portion defined by the crane attitude. The sensors are connected to circuitry including a programmable array logic chip which generates a signal representative of a binary number corresponding to the position of the particular sensor activated. A serial to parallel converter converts the parallel binary number to a serial number and transmits radio frequency signals with said serial binary number indicative of the pendulum position. The RF signal is received by a receiver indicator unit located in the operator control station of the crane. Circuitry converts the signals to indicator activating signals for an indicator panel on the receiver indicator unit. The indicator panel displays the direction and degree of tilt of the crane base by appropriately positioned visual indicators laid out in quadrants to incrementally indicate the degree and direction of the crane tilt whereby the crane operator may operate the crane leveling controls.

1. Drawings

[0001]Sheet 1.

[0002]Sheet 2.

[0003]Sheet 3.

[0004]Sheet 4.

[0005]Sheet 5.

Publication information

Citation

OpenTechnical Publication OT-2026-000003240, “Crane level indicator device,” published September 15, 2026 at 19:55:01 UTC, https://opentechnical.org/p/OT-2026-000003240.

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This record reproduces a document published elsewhere and is provided for reference and study. Rights in the original remain with its owner. See the publication policy.