CD 47 Edition 2007

[meaubry]

Hi Pete,

The ring grabber that you inquired about is pretty much automated, but the arm operator needs to coordinate opening the device with lowering the trolley.

The trolley is what allows the arm to move up and down a mast, as the motor walks up and down a chain. The bucket is hinged and opens and closes using a mechanism attached to a rack, which is driven by the window lift motor. At a specific point in the rack travel, the bucket is articulated open.

So, the arm operator simply locates overs the tube, and while lowering the trolley they push a button to drive the rack motor. While the tube pusher moves away from the tube, the bucket opens to clamp against the inside part of the tube. There is a switch to shut off the motor at the end of both the open and close travel positions.

The bucket also acts as a guide when aligning with the rack spider leg.

It didn't take the arm operator long to attain the skill to get really good at grabbing the tubes.

Mike