Apparatus and methods for sensing boom side deflection or twist
A crane includes a boom adapted for lifting a load and a sensor adapted for measuring the side deflection or twist of the boom during the lifting of the load. The crane may also include a system for detecting side deflection in the boom using a first sensor mounted to the boom for sensing a first value corresponding to deflection of the boom, a second sensor for sensing a second, reference value, and a controller for comparing the first and second values to determine a deflection amount. An operator may be notified if the side deflection or twist values exceed a predetermined value. Side deflection or twist values for the boom during a lifting operation may also be logged by a data recording device for later use.
1. A crane, comprising:
a boom adapted for lifting a load; and
a sensor adapted for sensing the side deflection or twist of the boom.
2. The crane of claim 1 , wherein the sensor comprises an inclinometer.
3. The crane of claim 2 , wherein the inclinometer comprises a single axis inclinometer.
4. The crane of claim 2 , wherein the inclinometer comprises a dual axis inclinometer.
5. The crane of claim 1 , wherein the sensor is mounted on a side of the boom.
6. The crane of claim 1 , wherein the sensor is mounted adjacent to a head of the boom.
7. The crane of claim 1 , wherein the sensor generates an output signal indicative of side deflection or twist, and further including a controller for processing the output signal into a user-perceptible form.
8. The crane of claim 7 , wherein the user-perceptible form comprises a numerical display of side deflection or twist.
9. The crane of claim 7 , wherein the user-perceptible form comprises a visual warning indicating that a predetermined level of side deflection or twist has been exceeded.
10. The crane of claim 7 , wherein the user-perceptible form comprises an audible warning indicating that a predetermined level of side deflection or twist has been exceeded.
11. The crane of claim 7 , further including a second sensor for providing a reference value, and a controller for comparing an output of the sensor with the reference value to determine the side deflection or twist of the boom.
12. The crane of claim 11 , wherein the second sensor is mounted to a base of the boom.
13. A method of manufacturing a crane, comprising:
providing a sensor for sensing side deflection or twist on a boom of the crane.
14. The method of claim 13 , wherein the providing step comprises mounting the sensor on a lateral side face of the boom adjacent to a head end thereof.
15. The method of claim 13 , further including the step of logging side deflection values to a data recording device associated with the crane during the lifting of a load by the crane.
16. A crane, comprising:
a boom for lifting a load; and
means for sensing the side deflection or twist of the boom.
17. The crane of claim 16 , wherein the means for sensing comprises an inclinometer.
18. The crane of claim 16 , further including means for indicating that a predetermined level of side deflection or twist has been exceeded.