Patent ID: 7562861
Filing Date: 2009-07-21
Classification: G02B,H02G

Abstract:
1. An apparatus comprising: a valve coupled to a first end of a duct, where the duct is configured to receive a cable at a second end of the duct, the second end being different than the first end of the duct, and where the valve controls a flow of a pressurized fluid outward from inside the duct to facilitate movement of the cable through the duct toward the first end; a controller to actuate the valve via a control interface; and a pressurized fluid source, coupled to the second end of the duct, to introduce the pressurized fluid into the second end of the duct, where the controller opens the valve to allow the flow of the pressurized fluid outward from inside the duct to reduce a pressure of the pressurized fluid in the duct, and where the controller opens the valve at a time based on a propagation delay of a pressure pulse traveling from the pressurized fluid source to the valve.