Sonic signalling transducer

Claim 3

The method of claim 1 wherein the members substantially obstructing fluid flow therepast are of a diameter less than the inside diameter of the pipeline.

Claim 4

The method of claim 1 wherein both the cylinder and piston are of an outside diameter substantially less than the interior diameter of the pipeline to define an annular space therebetween.

Claim 7

The device of claim 4 wherein the piston is of a diameter substantially less than the pipeline interior to define an annular chamber therebetween in which a pressure drop occurs as the ferret passes over a leak aperture.

Claim 8

A pipeline leak detector having an elongate body portion adapted for disposition within a pressurized fluid pipeline and comprising a pair of telescopically assciated members defining a piston and a closed end cylinder, a. means disposed within said piston for actuation of a signal in response to a pipeline leak over which the detector passes, b. means associated with said piston and cylinder to define with the pipeline inner wall an enclosed space in which a bounded volume of the stream fluid is substantially isolated from the mainstream, c. means for limiting the stroke of the piston within the cylinder, d. means housed within said piston and responsive to said leak signal for the release of pressurized gas into a chamber between said piston and the cylinder end, e. valve means associated with said cylinder end and normally biased open for fluid flow between the stream and the chamber and adapted to be instantly closed by the release of pressurized gas into the chamber, f. and packing elements carried respectively by said piston and cylinder to limit fluid flow thereby, whereby as the detector passes a leak, the signal initiated release of gas into the chamber closes the valve means and drives said packing elements apart to initiate sonic waves in both up and downstream directions within the stream.

Claim 9

A pipeline leak detector having an elongate body portion adapted for disposition within a pressurized fluid pipeline and comprising a pair of telescopically assciated members defining a piston and a closed end cylinder, a. means disposed within said piston for actuation of a signal in response to a pipeline leak over which the detector passes, b. means associated with said piston and cylinder to define with the pipeline inner wall an enclosed space in which a bounded volume of the stream fluid is substantially isolated from the mainstream, c. means for limiting the stroke of the piston within the cylinder, d. means housed within said piston and responsive to said leak signal for the release of pressurized gas into a chamber between said piston and the cylinder end, e. valve means associated with said cylinder end and normally biased open for fluid flow between the stream and the chamber and adapted to be instantly closed by the release of pressurized gas into the chamber, f. and packing elements carried respectively by said piston and cylinder to limit fluid flow thereby, whereby as the detector passes a leak, the signal initiated release of gas into the chamber closes the valve means and drives said packing elements apart to initiate sonic waves in both up and downstream directions within the stream.

Claim 10

The device of claim 6 including means for the concentric positioning of said cylinder and piston within a pipeline including a pair of impeding elements extending transversely of the pipeline and fixed respectively to the cylinder and piston, a. the element fixed to said piston being provided with a fluid passage leading to one side of said sensor, the opposite side of which is provided with a passage leading externally of the piston to the enclosed space between said packing elements, b. the packing element carried by said cylinder provided with a fluid passage to the stream, and with a check valve disposed interiorly thereof and biased open; whereby a signal from said sensor releases the compressed gas into said chamber to close the check valve and propel the cylinder and piston apart for generation of oppositely directed sonic signals in the stream.