Sonic pump for pumping wells and the like employing dual transmission lines

In a sonic pumping system for pumping liquid through a tubular string forming a conduit for said liquid , said system including means for generating vibrational energy at a sonic frequency coupled to one end of said string to effect resonant longitudinal vibration of said string, said string functioning as a transmission line for said energy, and valve system means mounted along said string for impelling liquid in response to said vibratory energy to effect the pumping action, the improvement comprising:

• a rod string coextensive with said tubular string and
• means for connecting said rod string to said tubular string such that said two strings vibrate in phase unison with each other to form a vibrating circuit which vibrates in a longitudinal resonant standing wave vibration mode, the impedances of said strings to lateral vibrations being substantially different,
• whereby said rod string forms a second transmission line for said energy, thereby increasing the Q (quality factor) of the vibration circuit formed by said two lines and raising the level of the energy at the ends of the lines remote from the energy generating means, lateral vibrations in said two strings being out-of-phase with each other such that they tend to cancel each other out.