Variable two stage air nozzle

Claim 2

A high-thrust low-noise nozzle adapted to effect movement of a secondary fluid by a pressurized primary fluid comprising, tubular means forming a passageway having an entrance and an exit orifice, said entrance being adapted for connection to a source of pressurized primary fluid, at least one port communicating with the passageway between said entrance and exit orifice, means cooperating with said port for directing flow of primary fluid from said port along the outside of said tubular means in a direction so as to induce flow of a secondary fluid along the outside of said tubular means toward said exit, noise-reducing means positioned in said passageway between said exit orifice and said port for effecting substantially laminar flow of the stream of pressurized primary fluid discharged from said exit orifice, said noise-reducing means creating sufficient back pressure to force some of the pressurized primary fluid to flow out of said passageway via said port, and means for varying the length of the outside of said tubular means over which secondary fluid flows as a function of the input flow of said primary fluid.

Claim 3

A nozzle according to claim 1 wherein said noise-reducing means comprises an element that is made up of a knitted metal wire mesh fabric that has been convoluted and compressed and molded into a self-supporting, dense, porous mass with the wire threads of said fabric oriented randomly in said mass.

Claim 4

A high-thrust, low-noise nozzle comprising a body having means defining a passageway, an entrance for admitting a pressurized primary fluid to said passageway, and an exit at one end of said body for discharging a stream of said primary fluid from said passageway, said body also having an exterior surface with a portion of said exterior surface disposed so as to converge toward said passageway at said one end, flow inducing means including at least one port communicating with said passageway between said exit and said entrance for conducting some of the pressurized primary fluid out of said passageway via said port and directing it along said portion of said exterior surface toward said one end so as to induce a secondary fluid surrounding said body to flow along said surface and merge with the stream of primary fluid discharged from said exit, and means for varying the length of said exterior surface along which said secondary fluid is induced to flow as a function of the input flow of said primary fluid.

Claim 5

A high-thrust, low-noise nozzle comprising a body having means defining a passageway, an entrance for admitting a pressurized primary fluid to said passageway, and an exit at one end of said body for discharging a stream of said primary fluid from said passageway, said body also having an exterior surface with a portion of said exterior surface disposed so as to converge toward said passageway at said one end, flow inducing means including at least one port communicating with said passageway between said exit and said entrance for conducting some of the pressurized primary fluid out of said passageway via said port and directing it along said portion of said exterior surface toward said one end so as to induce a secondary fluid surrounding said body to flow along said surface and merge with the stream of primary fluid discharged from said exit, and means for varying the length of said exterior surface along which said secondary fluid is induced to flow as a function of the input flow of said primary fluid.

Claim 6

A nozzle according to claim 3 wherein said flow-inducing means comprises an annular orifice communicating with said at least one port for directing fluid along said portion of said exterior surface toward said one end.

Claim 7

A nozzle according to claim 3 wherein said flow-inducing means comprises a second exterior surface on said body which is disposed so as to converge toward said passageway away from said exit end, and a transition surface that extends between said first and second mentioned exterior surfaces.

Claim 8

A nozzle according to claim 5 wherein said flow inducing means includes means spaced from said second exterior surface for directing primary fluid to flow from said port along said second exterior surface, so that substantially static secondary fluid surrounding said second exterior surface is induced to flow with primary fluid in turn over said transition surface and said first mentioned surface.

Claim 9

A nozzle according to claim 6 wherein said spaced means comprises an annulus surrounding and spaced from said body.

Claim 10

A nozzle according to claim 7 wherein said annulus surrounds the portion of said body that includes said port.

Claim 11

A nozzle according to claim 3 including a fluid-permeable element in said passageway between said exit and said port.

Claim 12

A nozzle according to claim 9 wherein said fluid permeable element comprises a compressed mass of a wire mesh fabric.

Claim 13

An amplifier air nozzle adapted to effect movement of a secondary fluid so as to produce a stream made up of said primary and secondary fluids at the exit of said nozzle, said nozzle comprising: a sleeve having means defining a first passageway therethrough and an entrance for admitting a primary pressurized fluid to said first passageway; tubular means forming a second passageway having an entrance and an exit, said tubular means being slidably disposed in said first passageway so as to be movable along its axis toward and away from the entrance of said first passageway between an extended position and a retracted position; a first chamber between said tubular means and said sleeve, at least one port in said tubular means for conducting said primary fluid from said second passageway to said first chamber, a first narrow orifice formed between said sleeve and said tubular means for conducting said primary fluid in a thin stream out of said first chamber toward the exit end of said nozzle; means for biasing said tubular means toward said retracted position; an elongate body having a tapered exterior surface, said elongate body being secured to the exit end of said tubular means and having a longitudinally extending bore in said body forming a third passageway extending from said second passageway; a second chamber between said tubular means and said body; at least one port in said body for conducting said primary fluid from said third passageway into said second chamber; a second narrow orifice formed between said tubular means and said body for conducting said primary fluid in a thin stream out of said second chamber and along said tapered exterior surface so as to induce a secondary fluid surrounding said housing to flow with said thin stream of said primary fluid along said tapered exterior surface toward said exit end of said nozzle and combine with the stream of said primary fluid discharged at said exit; and means for moving said tubular means from said retracted position toward said extended position by an amount proportional to the rate of flow of said primary fluid in said first passageway.

Claim 14

An amplifier air nozzle adapted to effect movement of a secondary fluid so as to produce a stream made up of said primary and secondary fluids at the exit of said nozzle, said nozzle comprising: a sleeve having means defining a first passageway therethrough and an entrance for admitting a primary pressurized fluid to said first passageway; tubular means forming a second passageway having an entrance and an exit, said tubular means being slidably disposed in said first passageway so as to be movable along its axis toward and away from the entrance of said first passageway between an extended position and a retracted position; a first chamber between said tubular means and said sleeve, at least one port in said tubular means for conducting said primary fluid from said second passageway to said first chamber, a first narrow orifice formed between said sleeve and said tubular means for conducting said primary fluid in a thin stream out of said first chamber toward the exit end of said nozzle; means for biasing said tubular means toward said retracted position; an elongate body having a tapered exterior surface, said elongate body being secured to the exit end of said tubular means and having a longitudinally extending bore in said body forming a third passageway extending from said second passageway; a second chamber between said tubular means and said body; at least one port in said body for conducting said primary fluid from said third passageway into said second chamber; a second narrow orifice formed between said tubular means and said body for conducting said primary fluid in a thin stream out of said second chamber and along said tapered exterior surface so as to induce a secondary fluid surrounding said housing to flow with said thin stream of said primary fluid along said tapered exterior surface toward said exit end of said nozzle and combine with the stream of said primary fluid discharged at said exit; and means for moving said tubular means from said retracted position toward said extended position by an amount proportional to the rate of flow of said primary fluid in said first passageway.

Claim 15

An air nozzle in accordance with claim 11, further including means disposed in said first chamber for maintaining said tubular means in a coaxial relationship with said first passageway.

Claim 16

An air nozzle in accordance with claim 12, wherein said means disposed in said first chamber comprises an annular guide ring surrounding said tubular means and providing at least one opening for discharging fluid from said first chamber.

Claim 17

An air nozzle in accordance with claim 13, wherein said means for biasing said tubular means also biases said guide ring adjacent said narrow first orifice.

Claim 18

An air nozzle in accordance with claim 11 wherein said tubular means includes a surface disposed transversely to the axis of said tubular means which is exposed to the air pressure in said second passageway, and further including flow modifying means for creating a back pressure in said passageways, the level of said back pressure being dependent upon the rate at which said primary fluid passes through said second passageway, said back pressure exerting a force on said surface of said tubular means so as to urge said tubular means toward said extended position.