Abstract: The present invention provides an acoustic sensor having one or more segments that are electrically coupled to provide a response corresponding to a hydrodynamic pressure applied to the segments. Each segment contains a substrate of a desired shape with a concavity on an outer surface that is sealingly enclosed by an active member made from a flexible, resilient piezoelectric material. PVDF material is preferably used as the piezoelectric active element. The active member is covered with a protective layer of a suitable material, preferably a polyvinyl material. A single segment may be used as a sensor or a plurality of suitably configured segments may be suitably coupled to form the sensor. The sensor may be used as a hydrophone on a hydrophone cable commonly used for performing seismic surveys for geophysical exploration. In such applications, a plurality of hydrophones are placed equally spaced along the cable. In the preferred embodiment, two hydrophone segments are securely be placed around the cable.

Abstract: A pressure compensated hydrophone assembly consists of a hollow mandrel that has an outer surface. The central portion of the outer surface of the mandrel defines a concavity. A flexible, resilient piezoelectric film is wrapped several times around the mandrel. The volume between the inner wrap of the film and the concavity on the outer surface of the mandrel serves as a pressure compensation chamber. The hydrophone is responsive to varying hydrodynamic pressure fields but is substantially inert to acceleration forces, localized impacts and variations in hydrostatic pressure.

Abstract: A piezoelectric film strip is wrapped a plurality of times around a flexible inert mandrel that has standoff collars on each end. The film-wrapped mandrel is hermetically sealed inside a hollow rigid inert cylinder. Electrodes provide electrical communication with the film strip which forms the active element of the transducer. Variations in hydrodynamic pressure flex the film strip in tension to generate a voltage.

Abstract: Disclosed herein is a control for a hydrostatic transmission, which control includes a control member operatively connected to the transmission for selectively moving the transmission between forward, neutral and reverse positions in response to control member movement, a pivotally movable member, an actuating member mounted for movement between forward, neutral and reverse positions, means connecting the actuating member with the movable member for pivoting the movable member in response to actuating member movement and connecting the actuating member and the control member for moving the transmission between forward, neutral and reverse positions in response to actuating member movement, and first and second arms pivotally mounted coaxially with, and independently of, the movable member and having outer free ends located in spaced relationship to each other.

Abstract: Disclosed herein is a sod cutter comprising a frame, wheels for movably supporting the frame for travel over the ground, a stripping blade on the frame for stripping a ribbon of sod in response to travel of the frame along the ground, a cutoff blade, a linkage movably mounting the cutoff blade on the frame for blade movement into the ground to transversely sever the sod ribbon, which linkage includes a cooperating roller on the frame and a follower mounted on the linkage and engageable with the roller for guiding cutoff blade movement in a vertical orientation during blade travel in the vicinity of the ground, and a drive on the frame and connected to the linkage for moving the blade into and out of the ground in response to travel of the frame along the ground.

Abstract: A lawn mower comprises a housing enclosing a rotary cutting blade. The housing includes a continuous sidewall having therein a side grass discharge opening and a top wall extending from the sidewall and having therein a top grass discharge opening. A deflector is located on the housing adjacent to the side discharged opening and is operative for movement between an open position permitting the escape of grass clippings through the side discharge opening and a closed position blocking the escape of grass clippings through the side discharge opening. The deflector is biased toward the open position. A grass discharge chute is detachably attached on the housing in communication with the top discharge opening. The chute includes a tab member which engages the deflector and moves the deflector from its open position to its closed position against the action of the bias during attachment of the grass discharge chute on the housing.