Abstract: A valve including annular valve seats, made of a resilient material such as rubber, fitted in respective valve seat retainers provided in the peripheral portions of fluid passages in the valve body. A gate is slidingly moved to open or close the valve, with its wall surface being maintained in contact with each valve seat. Each of said annular valve seats are brought into close contact with the wall of the gate when the gate is moved to a closed position to provide sealing therebetween. In addition, the valve comprises a fluid passage provided in the gate which serves to decrease the pressure of the fluid acting on the valve seat on the upstream side at the initial stage of the movement of the gate from the closed position to the open position, whereby the valve seat is biased from the gate.

Abstract: A crusher including a series of cutter units mounted on a pair of shafts arranged parallel to each other so as to rotate in the opposite directions to each other, wherein each of the cutter units is provided with a holder member which includes a flange portion and a boss portion, and a disc-shaped cutter blade secured detachably to the holder member and divided circumferentially into several segments, the cutter units on the respective shafts being so arranged that the disc-shaped cutter blades of every paired cutter units contact each other partly at their sides and that the disc-shaped cutter blade and flange portion of a cutter unit on one shaft are opposed to the boss portion of the mating cutter unit on the other shaft such that a space is formed between the peripheries of both cutter units; and each flange portion is provided with pawls along its outer periphery while each boss portion has provided along its periphery alternate ridges and recesses so designed as to maintain a substantially constant spac