Abstract: In the field of seismic exploration, compressed-air guns may be used as sound sources. Known air guns employed complex valving and were wasteful of compressed air. The air gun sound source of this invention is of simple construction and is economical of compressed air.The gun (10) consists of an elongated housing (34) that has at least one radially-positioned exhaust port. The housing is charged with a volume of compressed air. A hollow cylindrical actuator (60) is mounted inside the housing and may be hydraulically or pneumatically driven within the housing in longitudinal strokes. The actuator has at least one radially positioned aperture (88) alignable with the exhaust port. A valve or sealing pad (96) is mounted in each aperture. An orifice (104) is cut into each pad. At one end of an actuator stroke, the valve blocks the exhaust port in the housing.

Abstract: The electric multi-contact connector consists of twin half-housings. Each half-housing carries a plurality of contact holders independently mounted in spaced-apart relationship on a multi-bore base. The prong-end of each contact is resiliently supported by its holder and makes a water-tight joint therewith. When the two half-housings are moved into latching engagement, each pair of mating prong-ends of the opposite connector half-housings inosculate. Each prong-end is preferably serrated to improve the conductivity between each mating pair of prong-ends under adverse operating conditions.