Gas jet pump, and apparatus using same

A gas jet pump for producing a secondary flow of gas from a primary flow of gas, the pump comprising:

• a tubular body having a round inner surface defining a passage;
• a plurality of jet openings formed in the tubular body for introducing the primary flow into the passage, the jet openings being arranged in at least three axially spaced sets, the openings of each set being spaced circumferentially with respect to each other, each jet opening having axial and circumferential components and being substantially tangent to the inner surface of the tubular body, two of the sets of the jet openings being located adjacent each other proximate one end of the tubular body with the jet openings thereof oriented in the same axial direction, another set being located proximate the other end of the tubular body with the jet openings thereof oriented in the opposite axial direction as the jet openings of the first-mentioned two sets;
• and
• manifolds mounted on the tubular body for selectively feeding the primary flow of gas to the jet openings of each set such that the primary flow of gas fed therethrough flows vortically in an axial direction and moves a secondary flow of gas therewith through the passage.

Apparatus for use in bending heated sheet glass, the apparatus including a heating chamber, a horizontal conveyor for moving sheet glass through the heating chamber, a vacuum holder having a lower surface positioned above the conveyor and including spaced openings through the surface;

• a control system for the holder comprising:
• a gas jet pump located within the chamber and including an elongated tubular body having a round inner surface defining a flow passage, the tubular body having a first end communicating with the openings in the surface of the holder and a second end that opens within the chamber, and a plurality of jet openings formed in the tubular body in first and second axially spaced sets, each of the jet openings extending to the inner surface of the tubular body in a tangential relation therewith and having both axial and circumferential components with respect to the longitudinal axis of the tubular body, the axial component of each jet opening being oriented toward the second end of the tubular body away from the first end thereof;
• a source of pressurized gas located externally of the enclosed chamber;
• and
• valve means, interconnected between the source of pressurized gas and the gas jet pump, for selective communication of pressurized gas to one or both of the sets of jet openings in the tubular body such that gas from the source is introduced into the tubular body through the selected jet openings and flows vortically in an axial direction to move a secondary flow of gas therethrough through the flow passage, thereby developing a vacuum pressure in the holder of a first magnitude if one set of jet openings is selected and of a second magnitude if both sets are selected.

Apparatus for use in bending heated sheet glass, the apparatus including a heating chamber, a horizontal conveyor for moving sheet glass through the heating chamber, a holder having a lower surface positioned above the conveyor and including spaced openings through the surface;

• a control system for the holder comprising:
• a gas jet pump located within the chamber and including an elongated tubular body having a round inner surface defining a flow passage, the tubular body having a first end communicating with the openings in the surface of the holder and a second end that opens within the chamber, and a plurality of jet openings formed in the tubular body in first and second axially spaced sets, each of the jet openings extending to the inner surface of the tubular body in a tangential relation therewith and having both axial and circumferential components with respect to the longitudinal axis of the tubular body, the axial component of each jet opening of the first set being oriented toward the second end of the tubular body away from the first end thereof, and the axial component of each jet opening of the second set being oriented toward the first end away from the second end;
• a source of pressurized gas located externally of the enclosed chamber;
• and
• valve means, interconnected between the source of pressurized gas and the gas jet pump, for selective communication of pressurized gas to one or the other of the sets of jet openings in the tubular body such that gas from the source is introduced into the tubular body through the selected set of jet openings and flows vortically in an axial direction to move a secondary flow of gas therewith through the flow passage, thereby developing a vacuum pressure in the holder when the first set of jet openings is selected, and developing a positive pressure in the holder when the second set of jet openings is selected.

Apparatus for use in bending heated sheet glass, the apparatus including a heating chamber, a horizontal conveyor for moving sheet glass through the heating chamber, a holder having a lower surface positioned above the conveyor and including spaced openings through the surface;

• a control system for the holder comprising:
• a gas jet pump located within the chamber and including an elongated tubular body having a round inner surface defining a flow passage, the tubular body having a first end communicating with the openings in the surface of the holder and a second end that opens within the chamber, and a plurality of jet openings formed in the tubular body in first and second axially spaced sets proximate the first end of the tubular body and in a third set proximate the second end, each of the jet openings extending to the inner surface of the tubular body in a tangential relation therewith and having both axial and circumferential components with respect to the longitudinal axis of the tubular body, the axial component of each jet opening of the first and second sets being oriented toward the second end of the tubular body away from the first end thereof, and the axial component of each jet opening of the third set being oriented toward the first end away from the second end;
• a source of pressurized gas located externally of the enclosed chamber;
• and
• valve means, interconnected between the source of pressurized gas and the gas jet pump, for selective communication of pressurized gas to the sets of jet openings in the tubular body such that gas from the source is introduced into the tubular body through the selected jet openings and flows vortically in an axial direction to move a secondary flow of gas therewith through the flow passage, thereby developing a vacuum pressure in the holder of a first magnitude if one of the first or second sets is selected, a vacuum pressure of a second magnitude if both the first and second sets are selected, or a positive pressure in the holder if the third set of jet openings is selected.