GB2086321A

GB2086321A - Jet propulsion nozzle assemblies

Info

Publication number: GB2086321A
Application number: GB8024115A
Authority: GB
Original assignee: British Aerospace PLC
Current assignee: BAE Systems PLC
Priority date: 1979-08-15
Filing date: 1980-07-25
Publication date: 1982-05-12
Also published as: GB2086321B

Abstract

A jet propulsion nozzle assembly for effecting control of a flight vehicle, e.g. a guided missile, in the roll, yaw and pitch senses has a nozzle member (2) defining apertures (3) and a spoiler plate (4) with corresponding apertures (6). The plate (4) is mounted for rotation about the X-X axis to effect control in roll and for bodily lateral movement transverse to the X-X axis in two orthogonal directions to effect control in pitch and yaw by means including an annular support (9) carrying two spaced annular plates (11, 12) between which lies a further annular plate (13) projecting from a cylindrical carrier (10) closed at its rear end by the plate (4). The carrier (10) is connected by rods and yokes to piston/cylinder assemblies (Fig. 2, not shown) for effecting the displacement of the plate (4) always in a plane transverse to the roll axis. The plate (4) can accordingly have a flat forward face abutting against a flat rearward face of the nozzle member (2). <IMAGE>

Description

SPECIFICATION Jet propulsion efflux outlets This invention relates to jet propulsion efflux outlet assemblies for controlling a flight vehicle at least about its roll axis and preferably about its pitch and yaw axes in addition to effecting propulsion.

The flight vehicle may be, for example, a guided weapon in which case the efflux outlet assembly may form part of a rocket propulsion system.

According to the present invention a jet propulsion efflux outlet assembly for controlling a flight vehicle at least about its roll axis includes, in combination, nozzle means defining an aperture through which efflux issues to exert a propulsive thrust with at least one edge region of the aperture radially spaced further from the roll axis than other edge regions of the aperture, spoiler means having an impingement region on which the issuing efflux can impinge, actuating means to effect relative displacement between the nozzle means and the spoiler means within a plane transverse to the roll axis such that the efflux issuing from that part of the aperture remote from the roll axis impinges upon the impingement region and causes a change in the thrust direction which effects a torque acting at least in the roll sense.

Preferably, the spoiler means is in the form of a plate member positioned generally transverse to the issuing efflux adjacent but downstream of the nozzle means and the present invention has, for an objective, the provision of simple and effective actuating means for effecting movement of the spoiler plate member in its transverse plane. By such an arrangement, the plate member can have a flat forward face butting against a flat rearward face of the nozzle means thereby allowing a relatively inexpensive forming process.

Embodiments of an efflux outlet assembly are described with reference to the accompanying drawings in which: Figure 1 is an isometric view of an efflux outlet assembly incorporated in a guided weapon, the view having a segment bounded by planes A-X-B, A'-X-B' removed for clarity, the line X-X denoting the roll axis of the weapon, and, Figure 2 is a similar view illustrating an actuation mechanism in a diagrammatic manner with various segments removed.

A guided weapon 1 carries a nozzle member 2 which defines three apertures 3 through which efflux from a rocket motor, not shown, issues. The nozzle member 2 is fed by way of a duct 7 lying co-axially with the axis X--X; branches direct the efflux to all three apertures.

A spoiler plate 4 is mounted adjacent but downstream of the nozzle member 2 and has impingement lips 5 which bound three apertures 6, in this case matching the apertures 3, through which the issuing efflux flows. The nozzle member 2 is so shaped (i.e. the communicating regions between the duct 7 and the apertures 3 are initially of convergent and subsequently of divergent form) that the flow issuing from the apertures 3 is expanding. Accordingly, the apertures 6 in the plate 4 are shaped to allow this expansion to continue by being of increasing area from upstream to downstream. This feature is shown at reference numeral 8 in Figure 1.

The plate 4 is mounted for limited rotation about the X-X axis in both the clockwise and anti-clockwise directions and for bodily lateral movement generally transverse to the roll axis X-X in two orthogonal directions. Such mounting is provided by actuating means including an annular support 9 through which the duct 7 extends and a carrier 10 of cylindrical form, lying around a rear end of the duct 7 and the nozzle member 2, and carrying the plate 4 as an end wall of that cylinder. This latter feature has advantage in that efflux escape between the apertures 3 and the apertures 6 is minimised.

The annular support 9 comprises two spaced annular plates 11 and 12, anchored to the nozzle member 2 and the duct 7, between which a further annular plate 13 is constrained to lie by annular bearing races 14 and 1 5. The annular plates 11, 12 and 13 all lie in planes transverse to the roll axis X-X. The plate 13 is bodily movable in its own plane in any direction (that is to say, laterally) and can be simultaneously rotated around the roll axis. The annular plate 13 is rigidly connected to the carrier 10 and effectively forms an end wall of the cylinder remote from the plate 4.

Referring now also to Figure 2, which has the weapon outer skin removed, the annular support region partly sectioned, and a segment of the nozzle member 2 removed for ease of inspection, bodily and rotational movement of the plate 1 3 (with its own plane) and hence of its associated carrier 10 and plate 4, is effected by four equally spaced longitudinally extending rods, of which only two, referenced 1 6 and 1 7 respectively, are fully illustrated for clarity. A further rod is partly illustrated at 1 7a. The rods 1 6 and 1 7 lie opposite one another above and below the X-X axis, as drawn, whilst the other two non and partly illustrated rods lie opposite one another to the right and left of the X-X axis.Each rod terminates in a bearing sphere 1 8 at its rearward end.

Extending forwardly toward the rods from the annular plate 13 is a tubular coupling member 1 9.

This member has four (only three are shown) longitudinal slots 20 equally spaced around its forward end, the slots having open ends into which the rods protrude. The bearing spheres 1 8 engage the side walls of their respective slots.

Each rod is carried and operated by its own actuation mechanism, but since only the rods 1 6 and 17 are fully illustrated, it is convenient only to illustrate the actuation mechanisms 21 and 22 associated with these rods. The mechanisms associated with the other two rods are identical to those referenced 21 and 22.

Each mechanism includes a yoke 23. Each yoke 23 carries a rod 1 6 or 17 at its rearward end and has a bifurcated forward end pivoted to a transverse bar 24. The bar itself is pivotally carried by longitudinally extending piston rods 25, 26 associated with piston/cylinder assemblies 27 and 28 respectively.

In operation, longitudinal movement of the rod 25 and similar opposite movement of the rod 26 of the mechanism 21 causes the bar 24 to pivot about a vertical axis, as drawn, thereby causing its yoke 23 and its associated rod 16 to be swung laterally. Similar movements of the mechanism 22 cause the rod 1 7 also to be swung laterally. To effect bodily horizontal displacement of the plate 13 in its own plane and hence to effect similar movement of the plate 4, both mechanisms 21 and 22 are arranged to swing the rods 16 and 17 laterally in the same sense. For example, when the piston rods 26 move forward, the piston rods 25 move rearward and the rods 16 and 17 both move in the same direction so that the plate 4 is moved bodily in that same sense.

To effect rotation of the plate 13 and hence to effect similar movement of the plate 4 about the axis X-X, the rods 1 6 and 1 7 are moved differentially with reference to one another. For example, the piston rod 26 of rhe mechanism 21 is moved rearwardly whilst the piston rod 26 of the mechanism 22 is moved forwardly, so that the rods 1 6 and 1 7 swing in opposite senses.

The non-illustrated pair of mechanisms are arranged to operate in the same manner as that described with reference to the mechanisms 21 and 22.

If, as illustrated, the weapon is provided with fins, these can be operated simultaneously with the spoiler 4 to aid control. In Figure 2 a control fin 29 is associated with the mechanism 21 , a control fin 30 is associated with the mechanism 22, and other control fins are associated with the nonillustrated mechanisms.

To effect control movement of the fins, the bars 24 are provided with shafts 31 which, being integral with the bars 24 and positioned to lie on their pivot axis, rotate to effect fin rotation.

Claims

1. A jet propulsion efflux outlet assembly for controlling a flight vehicle at least about its roll axis including, in combination, nozzle means defining an aperture through which efflux issues to exert a propulsive thrust with at least one edge region of the aperture radially spaced further from the roll axis than other edge regions of the aperture, spoiler means having an impingement region on which the issuing efflux can impinge, actuating means to effect relative displacement between the nozzle means and the spoiler means within a plane transverse to the roll axis such that the efflux issuing from that part of the aperture remote from the roll axis impinges upon the impingement region and causes a change in the thrust direction which effects a torque acting at least in the roll sense.

2. A jet propulsion efflux outlet assembly according to claim 1 wherein the relative displacement to effect control in the roll sense is in the form of a rotational movement about the roll axis and relative lateral displacement between the nozzle means and the spoiler means may be additionally effected such that impingement of the efflux upon an impingement region of the spoiler means causes a change in the thrust direction to effect torques acting in the pitch and the yaw senses additonally to that acting in the roll sense.

2. A jet propulsion efflux outlet assembly according to claim 1 wherein the relative displacement to effect control in the roll sense is in the form of a rotational movement about the roll axis and relative lateral displacement between the nozzle means and the spoiler means is additionally effected such that the impingement region causes a change in the thrust direction to effect torques acting in the pitch and the yaw senses additionally to that acting in the roll sense.

3. A jet propulsion efflux outlet assembly according to claim 1 or claim 2 wherein the spoiler means comprises a plate member positioned generally transverse to the roll axis adjacent but downstream of the nozzle means, and the actuating means includes support means, and carrier means extending from the support means to carry the spoiler means, the support means allowing only bodily movement of the carrier means in the pitch and yaw senses and rotation in the roll sense.

4. A jet propulsion efflux outlet assembly according to claim 3 in which the carrier means is in the form of a cylinder, and the plate member of the spoiler means forms an end wall of that cylinder.

5. A jet propulsion efflux outlet assembly according to claim 3 or claim 4 wherein the support means includes two spaced fixed members, a movable member, and bearing means for constraining the movable member to lie between the fixed members for both rotational and bodily movement in a plane transverse to the roll axis, the movable member being connected to the carrier means.

6. A jet propulsion efflux outlet assembly according to claims 3, 4, or 5 wherein the actuating means further includes two longitudinally extending rod members, coupling means coupling the rod members to the movable member, the rod members lying diametrically opposite one another one to each side of the roll axis, and means to effect lateral swinging of the rods with reference to the roll axis both in the same sense and differentially.

7. A jet propulsion efflux outlet assembly according to claim 6 wherein the means to effect lateral swinging of each rod includes a pivoted yoke having a bifurcated portion between which the rod is attached and to which twin longitudinally extending jack means are connected for differential operation.

8. A jet propulsion efflux outlet assembly substantially as described with reference to Figure 1 of the accompanying drawings.

9. A jet propulsion efflux outlet assembly substantially as described with reference to Figure 2 of the accompanying drawings.

New claims or amendments to claims filed on 12th February 1 982.

Superseded claims 1 and 2.

New or amended claims:

1. A jet propulsion efflux outlet assembly for controlling a flight vehicle at least about its roll axis including, in combination, nozzle means defining an aperture through which efflux issues to exert a propulsive thrust with at least one edge region of the aperture radially spaced further from the roll axis than other edge regions of the aperture, spoiler means having an impingement region on which the issuing efflux can impinge, actuating means to effect relative displacement between the nozzle means and the spoiler means in the form of a rotational and/or lateral movement with respect to the roll axis such that a part of the efflux issuing remote from the roll axis impinges upon the impingement region and causes a change in the thrust direction which effects a torque acting at least in the roll sense.