Projectile launching system

This invention relates to launching systems. More particularly, although not exclusively, the method and apparatus relates to the launching of projectiles, such as missiles and satellites, into orbit.

It has been proposed to launch such projectiles by means of a multi-stage rocket in which successive stages are arranged one above the other. When the propellant in the first stage has been used up, this stage is jettisoned and the next stage is ignited. The final stage, usually the smallest, carries the payload. There are a number of disadvantages with this proposal. Such a launch takes a long time to prepare-for, is very expensive as the sections which are jettisoned cannot be re-used, a launch is often cancelled due to unfavourable meterological conditions, and only a small proportion of the total rocket is payload.

A further proposal for launching projectiles, such as missiles, is to use a barrel and a single propellant stage. This however has the disadvantage of limited range during which the propellant acts, and thus limited range over which the missile can be projected.

An object of the invention is to provide a projectile launching system which provides improvements in relation to payload and/or range, and/or improvements in relation to prior proposals so far as concerns simplicity of construction or operation, or consequential factors such as cost, or improvements in relation to providing such apparatus in mobile form, and/or other matters discussed herein, or generally.

According to the invention there is provided a projectile launching system, and a method of launching a projectile as defined in the accompanying claims.

One aspect of the invention provides a projectile launching system comprising a projectile, projection means for the projectile, and booster means to accelerate the projectile after activation of the projection means. The system is characterised by a barrel through which the projectile is projected, and booster means associated with the barrel. Previously proposed projectile launching systems in which a booster facility has been provided have been of the kind in which the projectile itself carries the booster means, with the above-mentioned disadvantages. By the provision of a barrel and associated booster means, these latter disadvantages can be mitigated or overcome, and directional control is improved.

A second aspect of the invention provides a projectile launching system in which a barrel through which a projectile is launched has booster means associated with it. Previously proposed barrel-launched projectile systems have been limited to the use of a single projection charge or impulse per projectile, whereby the latter's range and velocity are limited.

A third aspect of the invention provides a projectile launching system comprising a projectile, propulsion means for the projectile, and a barrel through which the projectile is propelled by the propulsion means. The system is characterised in that booster is provided, associated with the barrel, and activated by movement of the projectile by the propulsion means. The booster means is operative to additionally accelerate the projectile. Previously proposed barrel-launched projectile systems have been limited to a single charge or accelerating thrust from the projection means. The ability to employ booster means in a barrel-launched projectile system considerably adds to its potential range and velocity.

In a preferred embodiment of the invention, the projectile launching system comprises a large-bore barrel. The barrel may be formed from a number of shorter large-bore barrels joined end to end. At spaced intervals along the length of the barrel there are a number of successive valve means, such as sliding valves, associated with the barrel. After the projectile has been subjected to the propulsion means in order to initially project it from the inner end of the barrel, it passes through the valve means. The valve means are in an open position to allow the projectile to pass through. As the projectile passes through the valve means, sensing means locate the position of the projectile and the valve means is closed behind the projectile. Closure, or partial closure, of the valve means activates or brings booster means into position behind the projectile. The booster means, for example a charge, is detonated or ignited, and this provides extra propulsion for the projectile. This embodiment provides a system in which booster means are associated with a barrel for launching projectiles, in which no extra boosting apparatus is carried by the projectile, and the system allows the projectile to comprise mainly payload.

In a further embodiment, the projectile launching system comprises a large-bore barrel. Positioned successively along the length of the barrel are a number of valve means, such as sliding valves. Associated with the valve means are the booster means. After the projectile has been subjected to the action of an initial projection charge in order to initiate its movement lengthwise of the barrel, the projectile passes through the valve means. Sensing means locate the position of the projectile, and the valve means is closed. Closing or partial closing of the valve means activates or brings the booster means into position behind the projectile. The booster charge is detonated or ignited, and this provides extra propulsion for the projectile. This embodiment provides a projectile launching system in which a barrel system provides the advantages of multiple boost stages in a single barrel structure.

The invention also provides corresponding method aspects in addition to the above-described apparatus aspects.

In a further embodiment, the projectile is introduced into the base of the large-bore barrel by a hydraulic system or other suitable means. The booster charge is also introduced into the large bore-barrel to provide the initial acceleration. Once the booster charge has been detonated or ignited, movement of the projectile lengthwise of the barrel causes it to pass through the valve means and sensing means senses the position of the projectile and causes the valve means to close behind the projectile. Such closure brings a booster charge into position behind the projectile, and this latter is detonated. The detonation of the booster charge provides extra propulsion for the projectile.

In another embodiment, the booster means comprises a boost chamber or duct opening into the barrel of the apparatus through a side opening or port therein. Gas release means is provided to release gas from said boost chamber into the barrel behind a projectile passing lengthwise of the barrel, to accelerate same. Two or more such boost chambers may be provided at spaced locations along the barrel. In this way, the provision of valve means to provide a base between which, and the moving projectile, the booster means can act, is rendered unnecessary.

Cartridge packing or like cushioning material is provided at the inner end of the barrel, together with a heat shield to protect the inner end of the barrel during projection. Closable air vent means is provided to allow air in the barrel to exhaust when a projectile is inserted prior to projection.

The barrel may comprise a cylindrical or rectangular-section tube. This may be formed from cast-iron sections joined end-to-end.

In a preferred embodiment, the strengthening of the projection duct to enable larger projectiles to be used makes the duct strong enough to accommodate the high pressure required for launching a projectile beyond the earth's gravitational field. For this purpose, cast iron sections are encased in concrete and the barrel itself is located in a deep shaft, for example an old mine shaft. A service lift alongside the shaft provides access to it.

A propellant for the projectile is placed in a boost chamber which opens straight into the barrel. Electronic sensing means activates the propellant as a projectile passes that section, thus producing an explosion and a hot gas flow into the barrel.

Prior to projection, a projectile is lowered lengthwise of the barrel until it rests on a bed of cartridge-packing and a heat shield. During lowering, a vent at the bottom of the duct is opened to allow air to escape. When the projectile is in position, the vent is closed for launching.

The lowermost projection means for the projectile, to lift it from the base of the barrel, is carefully measured to provide just sufficient pressure to start the lift of the projectile. The shock-absorbing material at the bottom of the barrel helps to reduce the initial shock loading thereof. The second and further boost charges are progressively more powerful and combine to build up the necessary projection pressure for the projectile to be launched into space.

In a further preferred embodiment, the apparatus is greatly reduced in length and overall size and mounted on a mobile chassis to provide a mobile projection system. Apart from modifications required to reduce size and weight, the principles of the system remain unchanged in this embodiment.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

• Figs 1(a), (b) and (c) show, in diagrammatic form, a projectile being introduced into a barrel and the relative position of booster means. Fig 1(c) indicates, at the base of the drawing, a plan view of valve means 26 having a central projectile-receiving opening and a booster charge located alongside it; and
• Fig 2 shows, in diagrammatic form, a long bore barrel formed from a number of individual smaller barrels joined end to end;
• Figs 3 (a) to (e) show, in diagrammatic form, the movement of the projectile through the barrel and the relative position of booster and valve means as the projectile moves through the barrel;
• Fig 4 shows a longitudinal section through a projectile launching system;
• Fig 5 shows a transverse section through the barrel of Fig 4, taken on the line V-V in Fig 4; and
• Fig 6 shows the barrel of Figs 4 and 5 encased in concrete and illustrating three of the barrel joints seen in Fig 4.

As shown in Figs 1 to 3, a projectile launching system comprises a projectile 10 which is carried on a support or platform 12. Projectile 10 is introduced into the base 14 of a large-bore barrel 16 by means of a telescopic hydraulic lift system 18. The projectile 10 has projection means 20 associated with it. The projection means 20 is detonatable by detonation means 22 to provide initial propulsion to cause the projectile 10 to travel along the barrel 16.

As shown in Fig 1 (c) and Fig 3, booster means 24 are provided at intervals along barrel 16. Each booster means 24 successively accelerates projectile 10 lengthwise of the barrel. Each booster means 24 comprises a booster charge 25 associated with sliding valve means 26 in the form of a plate having a side opening 27 alongside booster charge 25. Figs 3(a) and 3(d) show the valve plate in its open and closed positions respectively. Fig 3(b) shows the projectile passing through the opening 27. The valve then closes, as shown in Fig 3(d), and booster charge 25 is then detonated. The valve means closes behind the projectile to provide a base against which the booster charge works.

Fig 1(a) shows projectile 10 in its pre-load position. Extension of hydraulic lift 18 raises the projectile to the Fig 1(b) position in which support 12 is held against breech plate 29 of barrel 16 for detonation of projection means 20 by detonation means 22.

In operation, after initial propulsion by projection means 20, projectile 10 travels lengthwise of barrel 16. The projectile moves through the sliding valve means 26 in their open position. Movement of projectile 10 is sensed and the valve 26 closes behind it. As the valve closes, the booster means 24 is located between the projectile 10 and the closed or closing valve 26. The booster means 24 is detonated, and this provides additional propulsion for the projectile 10. As the projectile travels through each valve 26, the process is repeated, and this provides sufficient extra propulsion for the projectile 10 to be launched into orbit, or otherwise. Fig 2 shows the regular sequential location of the booster means 24, lengthwise of barrel 16. Numerous modifications to the above embodiment are possible, while lying within the scope of the accompanying claims. It is envisaged that considerable variation in the design and mode of operation of the booster means may be made. For example, it may not be necessary to provide mechanical valve means as a part of the booster means, and an alternative system for providing a timed acceleration force to increase the velocity of the projectile may be provided, for example as shown in the following embodiment.

As shown in Fig 4, a barrel 100 comprises multiple barrel sections 102 joined end-to-end at joints 104. The entire barrel is encased in concrete 106. A vent 108 is provided at the base of the barrel.

Fig 5 shows a typical joint between barrel sections 102 which are formed as cast iron castings having flanges 110 suitably riveted or otherwise joined in end-to-end fashion. The castings define a boost chamber 112 closed by a plug 114 and opening through a port into the barrel 100.

The boost projection charge 118 is located within chamber 112.

In operation, a projectile (not shown) is lowered lengthwise of barrel 100 until it rests at the base thereof. During this operation, vent 108 is open. The vent is then closed. The boost charges 118 are positioned in each of the boost chambers 112 and plugs 114 are closed.

The lowermost charge in the barrel is then activated or ignited and the projectile begins to lift and passes lengthwise of the barrel. Sensing means (not shown) activates or ignites the succeeding booster charges in sequence, so that each acts to produce a charge of gas expanding into barrel 16 just behind the rear end of the projectile, thereby progressively accelerating it.

Interestingly, the above embodiments provide a system whereby a projectile of missile is further accelerated after initial propulsion, and without the need for the booster system to be carried by the projectile itself.