US 5,673,491 AGranted

Crane level indicator device

OwnerDouglas J. Brenna, Shirley A. Brennainventors

Life of this patent

Estimating the term…

Loading patent…

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.

Claims8

Dependent claims

A level indicator device for a crane, of the type which is positionable on an operating surface and which has a frame, an operator station, and leveling controls for adjusting the gravitational level of the crane, the level indicator device comprising:

a) a remote sensor sending unit positionable on the crane, and a receiving indicator unit placeable at the operator station, the remote sensor unit comprising:
1) a housing, the housing anchorable to the crane frame;
2) a planar sensing region fixed to the housing and comprising an in-level sensor portion and a plurality of out-of-level sensor portions;
3) a pendulum suspended in the housing and confronting the sensing region, the pendulum swingable in two axis, the pendulum having a contact member for contacting and making electrical contact with the individual sensor portions, the pendulum having an axis with the contact member axially positioned and axially moveable with a bias toward the sensing region, whereby the contact member maintains contact with the sensing region as the pendulum swings in an arc, the pendulum and sensing region configured such that the contact member activates the in-level sensor portion when the crane is level and the out-of-level sensor portions when the crane is out-of-level;
and
4) sensor unit circuitry including a radio frequency transmitter portion, the circuitry connected to each sensor portion, the circuitry configured to generate and transmit signals indicative of the particular sensor portion activated by the sensor activator;
b) the receiving indicator unit comprising:
1) a display panel having a plurality of visual indicators, the visual indicators each corresponding to a particular sensor portion;
2) circuitry for receiving and processing the rf signals indicative of the sensor portion being activated, the circuitry connected to the visual indicators and configured to convert said signals into activation signals for activating the visual indicators corresponding to the activated sensor portion;
and
3) a power source connected to the processing circuitry for powering said circuitry.

8 more elements

A level indicator device for a crane of the type of which is positionable on an operating surface, and which has a frame with four quadrants, leveling controls for adjusting the height of each of the four quadrants of the frame with respect to the operating surface such that the crane may be leveled, the level indicator device comprised of:

a) a housing, the housing anchorable to the crane base and tiltable with said base;
b) a planar sensing region fixed to the housing and comprising an in-level sensor portion and a plurality of out-of-level sensor portions;
c) a pendulum suspended in the housing and confronting the sensing region, the pendulum swingable, the pendulum having an axis and a contact member for contacting and activating the individual sensor portions, the contact member axially moveable with a bias toward the sensing region, whereby the contact member maintains contact with the sensing region as the pendulum swings in an arc, the pendulum and sensing region configured such that the contact member activates the in-level sensor portion when the crane is level and the out-of-level sensor portions when the crane is out-of-level and wherein the pendulum is elongate with a midpoint and wherein the pendulum has a center gravity above said midpoint;
d) a display panel having a plurality of visual indicators, the visual indicators each corresponding to a particular sensor portion;
and
e) device circuitry connected to the sensor activator, the individual sensor portions, and the display panel, the circuitry configured to generate signals indicative of the particular sensor portion activated by the sensor activator and to activate the visual indicators corresponding to the particular sensor portion activated.

3 more elements

Dependencies are inferred from the claim text.