US3041829A

US3041829A - Improvements to jet deflecting devices, particularly for discharge nozzles of propulsion units

Info

Publication number: US3041829A
Application number: US816156A
Authority: US
Inventors: Gelin Paul
Original assignee: SNECMA SAS
Current assignee: Safran Aircraft Engines SAS
Priority date: 1958-06-05
Filing date: 1959-05-27
Publication date: 1962-07-03
Anticipated expiration: 1979-07-03
Also published as: DE1095676C2; DE1095676B; GB886198A; FR1198179A

Description

y 3, 1962 P. GELIN 3,041,829

IMPROVEMENTS TO JET DEF'LECTING DEVICES, PARTICULARLY FOR DISCHARGE NOZZLES OF PROPULSION UNITS Filed May 27, 1959 5 Sheets-Sheet 1 July 3, 1962 P. GELIN 3,041,829

DEFLECT DEVIC IMPROVEMENTS TO JET PARTICULARLY FOR DISCHARGE NOZZLES PROPU ON UNITS 59 3 Sheets-Sheet 2 Filed May 27, 19

y 1962 P. GELIN 3,041,829

IMPROVEMENTS TO JET DEFLECTING DEVICES, PARTICULARLY FOR DISCHARGE NOZZLES OF PROPULSION UNITS 3 Sheets-Sheet 5 Filed May 27, 1959 3,941,829 Patented July 3, 1962 flfice 3,041,829 IMIRDVEMENTS T JET DEFLECTING DEVICES, PARTICULY FGR DISCHARGE NOZZLES OF PROPULSION UNITS Paul Gelin, Paris, France, assignor to Societe Nationals dEtude et de Construction de Moteurs dAviation, Paris, France, a company of France Filed May 27, 1959, Ser. No. 816,156 Claims priority, application France June 5, 1958 8 Claims. (Cl. 6035.54)

In order to exert a braking action on jet-propelled aircraft, and for other purposes, it has already been proposed to provide a device for deflecting the jet of the discharge nozzle which operates by interposing in the jet obstacles so arranged as to deflect the jet through a grid of vanes, the jet thus serving to produce a counter-thrust which provides a brakintg effect.

In the United States Patent No. 2,797,547 to Meulien et al., granted July 2, 1957, there is described a device for deflecting a jet by means of streamlined pivotable blades associated with a grid of vanes, but the blades are always situated in the jet both during the deflection period (flat surface of the blade directed perpendicularly to the jet) and also in a non-deflected period (streamlined surface of the blade in the path of the jet).

The present invention relates to an improvement in deflectors of this kind using streamlined blades adapted to pivot about their axes, the said improvement consisting in that each of the blades is divided into two half-blades which, by pivoting about axes perpendicular to the axis of the discharge nozzle, can be situated in a withdrawn position out of the jet during non-deflecting periods, each of the half-blades thus being capable of a double pivoting movement, one about axes perpendicular to that of the nozzle, the other about their own axis. The introduction of the half-blades into the jet, in order to bring them from the completely withdrawn position to the non-active waiting position within the jet, is effected without great effort, the blades remaining parallel to the direction of the jet during this operation.

The description which will now be given with reference to the accompanying drawings, given by way of nonlimitative example, will make it readily understood how the invention can be carried into effect, the features which are brought out both from the text and from the drawings being understood to form part of the said invention.

FIG. 1 is an axial sectional view of a discharge nozzle provided with a device according to the invention, the upper half of this figure showing the device withdrawn outside the deflecting periods, whereas the lower half of this figure shows the device in position for the purpose of deflecting the jet.

FIG. 2 is an end view of the nozzle with the same division of the figure as above.

FIG. 3 is a view on a larger scale showing one of the ends of the blades in the pre-deflecting position.

FIG. 5 is a similar view showing the blades in the jetdeflecting position.

FIGS. 4 and 6 are respectively sectional views taken on IV-IV and VIVI of FIGS. 3 and 5.

FIG. 7 is a view from above, the blades being withdrawn.

FIG. 8 is a view from above, the blades being in a pre-deflecting or deflecting position.

FIG. 9 shows a constructional detail of the jack means controlling the movement of the blades.

FIG. 10 is a sectional view taken on line X-X of FIG. 3.

In FIGS. 1 and 2, the discharge nozzle 1 of a reaction propulsion unit is followed by a jet deflecting device which comprises: a collar or sleeve 2 constituting an ejector for drawing in outside air and terminating in a flared rim 2a, a retractable obstacle constituted by four streamlined half-

blades

4, 5, 6 and 7, and a grid of vanes 3.

In FIGS. 3 and 4, each of the blades such as 4 is articulated to a strap 8 by means of a pin 9. The introduction of the blades 4 and '5 into the jet is effected by operating the rack 10 entraining the toothed sector 11 on which is fixed a fork 12. This fork 12, engaged in a recess 13 formed in the blades such as 4, moves the latter into the desired position. In this recess 13, the blade 4 comprises a cylindrical portion of revolution 4a.

In FIG. 7, the rack 10 is operated by a jack 14 of the screw and nut kind and therefore irreversible, which ensures locking of the blades in the desired position.

' and 19.

The jack 14 is of the nut and screw type. By rotating the gear wheel 20, the gear wheel-nut 21 drives in translational movement the rack 10 which operates the gear wheel 11 of the fork 12.

The jack 1? is also of the nut and screw type and is incorporated in the same casing as the jack 14. By rotating the gear wheel 22, the gear wheel-nut 23 drives in rotational movement the screw 24 which, by means of a rocker arm 17 and rods 18 permits the rotation of the levers 15.

in the arrangement corresponding to the normal working state, the blades being in a position parallel to the axis of the nozzle and the grid of vanes in the withdrawn position (upper half of FIG. 1), the device is entirely out of the jet and thus causes neither drag nor loss of thrust.

In a first stage, the blades pivot about the pins 9 and penetrate into the jet. These blades are driven by the fork 12 whose movement is controlled by the jack 14 through the agency of the rack 10. Thus, the blades 4 progressively come into the pre-deflecting position, offering the jet the minimum resistance by their streamlined frontal surface.

In a second stage, the jack 19 causes the blades to pivot about the axes 0 by means of the

elements

15, 16, 17, 18. Thus the blades, in pivoting on themselves through an angle which may be as much as cease to present their streamlined frontal surface to the jet and gradually present their lateral surface, forming an obstacle to the flow of the jet.

The devices described hereinbefore permit the manipulation of the blades with only slight force since the blades are introduced into the jet by their streamlined face. This makes it possible to have a small jack installation and the entire installation can easily be arranged in an aircraft.

I claim:

1. In a jet propulsion unit having a propulsive nozzle designed for producing a jet issuing axially therefrom, a device comprising a concealable set of guide vanes disposed externally of the nozzle and arranged, when exposed, to define successive, laterally directed passages for the jet, half-blades intended to deflect the jet. from the axis of said nozzle into said passages, said half-blades having flat surfaces and tapered edges and being rotatable about first axes of rotation normal to the axis of said nozzle outside said jet and about second axes of rotation coinciding with the geometrical axes of said half-blades, said second axes intersecting the nozzle axis normally thereto and also being normal to said respective first aXes, first operating means for moving said half-blades about said first axes of rotation from a withdrawn position outside the jet into a non-active position within the jet for which said half-blades offer their tapered edges to the jet, and second operating means for moving said half-blades on themselves about said second axes of rotation so that said half-blades gradually present their flat surfaces perpendicularly to the jet and deflect said jet into said passages of said set of guide vanes.

2. A device according to claim 1, wherein the second operating means comprise a jack, and levers fast with said half hlades and actuated by said jack through a rocker arm. I

3. A device according to claim 1 wherein the first and second operating means comprise jacks of the nut and screw kind effecting irreversible drive and therefore locking of the half-blades in the desired position.

4. A device according to claim 3, wherein the two jacks are incorporated in only one casing. I

5. In a jet propulsion unit having a propulsive nozzle designed for producing a jet issuing axially therefrom, a device comprising a concealable set of guide vanes disposed externally of the nozzle and arranged, when exposed, to define successive, laterally directed passages for the jet, half-blades having cylindrical end portions and intended to deflect the jet from the axis'of said nozzle into said passages, said half-blades having fiat surfaces and tapered edges and being rotatable about first axes of rotation norm-a1 to the axis of said nozzle outside said jet and about second axes of rotation coinciding with the geometrical axes of said half-blades, a jack and a fork member operated by said jack, said fork member cooperating with said cylindrical end portions for moving said half-blades about said first axes'of rotation from a withdrawn position outside the jet into a non-active position within the jet for which said half-blades offer their tapered. edges to the jet, and operating means for moving said halfblades on themselves about said second axes of rotation so that said half-blades gradually present their flat surfaces perpendicularly to the jet and deflect said jet into said passages of said set of guide vanes.

6. A device according to claim 5, wherein said operating means comprise a second jack, and levers fast with said half-blades and actuated by said second jack through a rocker-arm.

7. A device according to claim 6, wherein said second jack as well as said jack operating said fork are of the nut and screw kind effecting irreversible drive and therefore locking of the half-blades in the desired position.

8. A device according to claim 6, wherein the two jacks are incorporated in only one casing.

References Cited in the file of this patent UNITED STATES PATENTS 1,818,067 Kookogey Aug. 11, 1931 2,723,091 Davies et al. Nov. 8, 1955 2,797,547 Meulien et a1 July 2, 1957 2,797,548 Marohal et a1. July 2, 1957 2,841,954 Rainbow July 8, 1958 2,846,164 Haberkorn Aug. 5, 1958 2,850,977 Pollak Sept. 9, 1958 FOREIGN PATENTS 1,092,654 France Nov. 10, 1954 778,008 Great Britain July 3, 1957