Crane safety apparatus

• US 5,730,305 A
• Filed: 11/02/1994
• Issued: 03/24/1998
• Est. Priority Date: 12/27/1988
• Status: Expired due to Fees

• Current Assignee: Kato Works Co., Ltd.
• Original Assignee: Kato Works Co., Ltd.
• Inventors: Tsutsumi, Yukio, Ichiba, Akinori
• Primary Examiner(s): Merritt, Karen B.
• Assistant Examiner(s): JOHNSON, RAYMOND B
• Application Number:
  US08/333,243
• Time in Patent Office: 1,238 Days
• Field of Search: 364/463, 364/464, 340/438, 340/289, 340/940, 340/525, 340/306, 340/685, 340/686, 340/984, 37/DIG. 1, 37/DIG. 20, 414/394, 212/276-281, 212/284
• US Class Current: 212/276
• CPC Class Codes: B66C 23/905 electrical

Abstract

A crane safety apparatus for displaying a schematic diagram of a part of a crane mechanism on a two-dimensional screen dynamically as the crane mechanism is operated, and displaying on the same screen a predetermined operation zone as a visually discriminative zone pattern. The operation zone pattern is displayed on the screen in response to the key command by an operator during a selected crane operation mode, while referring to the schematic crane mechanism diagram currently displayed on the screen.

Claims

1. A crane safety operation display apparatus for use with a crane mechanism having a crane structure with a boom and at least one outrigger mounted thereon to aid in preventing the crane mechanism from overturning, comprising:

a plurality of sensors connected to the crane mechanism for generating crane status signals at predetermined intervals that correspond to crane mechanism parameters such as boom length, boom angle, and slewing angle;

means for generating an outrigger status signal;

an operation limit memory for storing crane operation limit data;

display means having a two-dimensional screen and a display memory, wherein the display means utilizes data in the display memory to produce a boom diagram depicting a boom extending from a fixed point on the screen;

means for selectively generating a plurality of crane operating modes on said display means;

key means having a plurality of keys for selectively generating either a slewing angle display mode signal or a boom work zone display mode signal; and

control means connected to each of the respective sensors, the display means, the outrigger status signal generating means and the key means, and responsive to the crane status signals for generating display data and for loading the generated display data into the display memory, and wherein the control means in response to a crane outrigger status signal accesses the crane operation limit data in the limit memory and calculates boom safety slewing display data which automatically varies with changes in the status of the outrigger, wherein the calculated boom safety slewing display data is loaded into the display memory and in response to the slewing angle display mode signal the control means instructs the display means to display a boom safety slewing area diagram simultaneously with the boom diagram on the screen for viewing, wherein the boom safety slewing area diagram is a closed curved line displaying boom safety slewing limits for safe operation of the crane mechanism about the fixed point, whereby an operator can determine from the screen if the boom diagram is within the boom safety slewing area diagram which indicates that the crane mechanism is not in danger of overturning to ensure safe crane operation, and

the control means in response to the boom work zone display mode signal instructs the display means to display the boom diagram on the screen, and responsive to a boom work zone instruction generated upon key actuation of the key means by an operator, a stationary boom operation range limit zone pattern is displayed simultaneously with the boom diagram on the screen for viewing.

2. A crane operation display apparatus according to claim 1, wherein the boom safety slewing display data is calculated at predetermined intervals and the display data for the boom safety slewing area diagram is produced from the calculated boom safety slewing display data to update the boom safety slewing area diagram displayed on the screen.