Abstract: A check valve has a pivotal arm for striking a flap against a seal that has a knife edge for cutting occasionally lodged debris. The flap without an integral arm is light to provide minimum resistance to flow of fluid in a normal direction. Greater efficiency permits a spring for biasing an actuating mechanism that is aligned with the pivotal arm to be weaker so that fluid can flow more readily in a normal direction and the spring can be reset easier.

Abstract: In place of one of the usual blunt seats, a sewer check valve has a knife-edge extending from one of the seats to eliminate holding of compressed, relatively tough chunks of sewage between seats by cutting through the chunks, and has room for the cut pieces to move away from the seats. The flap of the valve has a lever extending therefrom, and a spring actuated rod retained by a catch is released to strike against the lever for forcing the flap against the knife-edge. The catch may be released manually, but is preferably released by slightly delayed operation of a solenoid in response to operation of a level sensing device in the housing of the valve.

Abstract: A hollow body is connected by a compression seal and a split collar over a closed end of a first pipe containing fluid under pressure. A lateral screw-type cutter connected to the body has a circular knife edge with one or more scallops, the knife edge being formed and being positioned to cut cleanly a single slug from a first pipe at a point within the body near the seal. An end of the body opposite that end sealed to the first pipe has a nipple to which a second pipe is connected, and a strainer positioned across the nipple retains the slug within the body. Space between the first pipe and the body is sufficient to provide a passgeway for full flow of fluid through the hole of the first pipe to the nipple for the second pipe. The second pipe usually continues in a direction coaxial with the first pipe.

Abstract: A pair of strips having spaced cutouts therein are placed in lapping relation so the cutouts form openings to receive insulating bushings having circumferential grooves therearound at least some of the end margins of the intervening webs between the cutouts being retroverted to take the form of barbs which in the assembled relation face corresponding barbs of the other strip.

Abstract: A support strip for insulating bushings has spaced cutouts therein to receive the bushings. A locking bar which closes the open side of the cutouts to hold the bushings in place is arranged so that it interengages with the web portions between the cutouts by being received on first one side and then the other side of successive webs.

Abstract: A pear tree, denominated "San Joaquin", having fruit ripening for picking about June 11 and to full maturity about June 20, at early maturity having deep green ground color with a brown-red blush in a partially solid, partially striped pattern, the ground color lightening to reach a bright yellow at full maturity and the blush a cherry red.