Devices for producing vacuum using the Venturi effect having a solid fletch
Device for producing a vacuum using the Venturi effect are disclosed that have a housing defining a suction chamber, defining a motive passageway includes a tapering portion most proximate the suction chamber that convergingly tapers from a motive entrance to a motive exit into the suction chamber, the motive exit being in fluid communication with the suction chamber, and defining a discharge passageway having a discharge entrance in fluid communication with the suction chamber and divergingly tapering as it extends away from the suction chamber, and having a solid fletch centered within the tapering portion. The device can include a fletch-partition disposed in the motive passageway and dividing the motive passageway into two flow paths along opposing sides of the partition. The solid fletch divergingly tapers toward the suction chamber as it extends from the partition, thereby providing a circumferentially continuous flow of fluid around the fletch.
1. A device for producing a vacuum using the Venturi effect, comprising:
a first housing defining a suction chamber, defining a motive passageway which includes a tapering portion most proximate the suction chamber that convergingly tapers from a motive entrance to a motive exit into the suction chamber, the motive exit being in fluid communication with the suction chamber, and defining a discharge passageway having a discharge entrance in fluid communication with the suction chamber and divergingly tapering as it extends away from the suction chamber; and
a fletch having a first solid body section positioned centrally within the motive passageway without connection to a wall of the tapering portion and defining a first end at or proximate the motive exit, thereby providing a circumferentially continuous flow of fluid around the fletch, and a second solid body section extending from the first solid body section perpendicular thereto and through a motive passageway wall upstream of the tapering portion;
a second housing having an airtight seal with the first housing to define a portion of the suction chamber and a suction passageway;
wherein an end of the second solid body section extends through the motive passageway wall is mated to the second housing.
2. The device of claim 1 , wherein the motive passageway and the discharge passageway each protrude into the suction chamber as a spout and the exterior surface of the spout of the motive passageway converges toward the motive exit.
3. The device of claim 1 , wherein the suction chamber defines a check valve housing a sealing disc translatable between an open position and a closed position based solely on pressure differentials.
4. The device of claim 3 , wherein the open position is defined by fingers protruding from positions proximate the motive passageway and the discharge passageway toward a suction passageway or by an insert comprising an outer support seatable in the suction chamber and an inner annular ring spaced radially inward from the outer support by a rib that angles axially toward a central longitudinal axis of the suction chamber to position an upper surface of the inner annular ring a distance axially beyond an upper surface of the outer support.
5. The device of claim 4 , further comprising a cap sealingly fitted to the suction chamber to define a bottom thereof opposite the suction passageway.
6. The device of claim 1 , wherein the exterior shape of the first solid body section matches the shape of the interior profile of the tapering portion of the motive passageway.
7. The device of claim 6 , wherein the first solid body section has a rectangular cross-section or an elliptical cross-section.
8. The device of claim 1 , wherein the fletch is integrally molded as part of the housing.