Abstract: A dental cast tray assembly used to form a dental cast model comprises a base and a tray removably mounted on the base. The base includes a top surface which is recessed to form a support surface and a pair of restriction walls which protrude up from the support surface, each restriction wall including a plurality of surface irregularities. The base also includes an elongated, tubular projection which extends nearly the entire length of the base. The projection includes a rounded top, a pair of inwardly curved sidewalls and an elongated slot. The tray includes an elongated socket which includes a pair of thin fingers that are capable of flexion. The socket defines an opening into which the projection is capable of being releasably press-fit. The tray is notched to form first and second outer restriction walls, each outer restriction wall including a plurality of surface irregularities which are sized and shaped to engage the surface irregularities formed on the base.

Abstract: A dental cast tray assembly used to form a dental cast model comprises a base and a tray removably mounted on the base. The base includes a top surface, a flat bottom surface and a plurality of cylindrically-shaped projections formed on the top surface. The tray includes a bottom surface and a top surface. The bottom surface of the tray is generally flat and includes a plurality of openings, each opening being sized and shaped to receive an associated projection therewithin when the tray is mounted on the base. The top surface of the tray is recessed to form a support surface and a sidewall protruding up from the support surface, the support surface and the sidewall together defining an enclosed reservoir for holding the dental cast model. A plurality of spaced apart retention walls are formed on the support surface of the tray for retaining the dental cast model.

Abstract: In one embodiment of the present invention, a dental cast tray assembly used to form a dental cast model comprises a base and a tray removably mounted on the base. The base includes a top surface, a flat bottom surface, a front wall, a rear wall and a plurality of projections formed on its top surface in a non-recurring, random pattern. Each of the plurality of projections is generally cylindrically-shaped and includes a convex free end. The tray includes a top surface adapted to support the dental cast model, a flat bottom surface, a front wall, a rear wall, a retention bar formed on its top surface and a plurality of openings formed in its bottom surface in the same non-recurring, random pattern in which the plurality of projections are disposed on the base. Each of the plurality of openings is defined by four sidewalls and is generally hourglass shaped in lateral cross-section. Two of the four sidewalls which define each of the plurality of openings include an elongated rib.

Abstract: An apparatus for reducing between-stage entanglement of fibrous materials around a rotating impeller drive shaft in a multi-stage vertical turbine pump includes a fluted sleeve on the rotating impeller drive shaft and a notched cutter ring fixed to a stationary inner wall of a lower pump stage for engaging with the fluted sleeve to comminute fibrous materials by shearing action between the notches and the flutes. If necessary, a discharge transition piece may be used to adapt the upper end of an upstream pump stage bowl to the lower end of a downstream bowl.

Abstract: An open bowl for a vertical turbine pump, includes a bowl body having an inner wall and an outer wall, both walls being of substantially constant optimum thickness, surrounding a vertical axis and connected by diffuser vanes which define hydraulically optimized diffuser passages through the bowl body extending from a bottom end to a top end, the diffuser vanes being radially hollow and providing open paths through the inner and outer walls to a cavity surrounded by the inner wall; a flange at the top end of the outer wall for attachment of a discharge conduit for the pumped fluid; provision on the bottom end of the outer wall for attaching to a flange of a suction bell; further provision on an inner surface at the top of the inner wall for providing sealing engagement with an upper end of a separable substantially cylindrical bearing housing; and provision at the bottom end of the inner wall for attaching to a flange of the bearing housing.

Abstract: A bearing housing in a bowl of a vertical turbine pump for a lower bearing of a rotatable pump shaft on which an impeller is mounted includes a separable hollow substantially cylindrical housing body with upper and lower ends, having a radial flange at its lower end adapted for sealing attachment to a bottom face of the bowl such that it is capable of installation in and removal from the bottom face of the bowl, the housing body also having an inside diameter greater than an outside diameter of the shaft to provide a clearance therebetween. A bearing is fixed within the lower end of the housing body for journaling the shaft therein, and provision is made for sealing between the upper end of the housing body and an internal axial bore in the bowl. A seal is also provided between the lower end of the housing body and the shaft for excluding pumped fluid from the clearance.