Safe and arm ejection system

BACKGROUND OF THE INVENTION ³⁰

Field.—This invention relates generally to an ejection system for ordnance items and more particularly to an ejection system which includes means for safing and arming the ordnance item. 35

Ordnance items such as bombs, flares and sonobuoys are commonly carried in groups in launchers suspended beneath the wings of aircraft. A preferred way to carry such items is in a launch tube which holds a plurality of ordnance items and ejects them individually or in 40 groups. For safety’s sake, it is desirable to keep the ordnance items in an unarmed condition until they have separated from the aircraft.

Prior art.—There are many safe and arm systems now in use, but all have disadvantages, the chief one being 45 that they are complicated and expensive. For example, many systems require that the pilot of the aircraft arm the ordnance by means of mechanical linkages. This is not desirable because of the complications that such linkage adds to the structure of the aircraft, plus the ⁵⁰high probability of malfunction, especially if the aircraft is being fired upon. In other systems the ordnance is partially armed before being loaded into the launch tubes, and requires certain movements to complete the arming. This arrangement is obviously less than desir- ⁵⁵able.

SUMMARY OF THE INVENTION

The instant invention provides a safe and arm system for tube-launched ordnance items. The ordnance can be 60 electrically or mechanically armed or activated. Briefly stated, this system comprises a launch tube, a plurality of ordnance items, an ejection system and an arming system. Each load of ordnance items consists of a “stack” composed of a plurality of the items releasably attached 65 together to facilitate handling and loading. Rearward of each ordnance item is an ejection device which is electrically actuated through means carried by the launch tube. A single item or a selected number of items, up to and including the entire load, can be ejected from the 70 launch tube at one time. Electrically armed ordnance items are armed by application of electrical power as they leave the launch tube, while mechanically armed items include bore-riding pins which allow arming only upon ejection from the tube. In addition, in the mechanically armed embodiment, adjacent ordnance items are interlocked with connector pins to hold them together and to lock the bore-riding pins in the safe position until separation.

The primary object of this invention is to provide a safe and arm system for tube-launched ordnance items.

Another object of this invention is to provide ordnance items which are kept unarmed until launch.

Still another object of this invention is to provide ordnance items which can be easily and safely handled.

Other Objects, advantages and novel features of this invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings.

THE DRAWINGS

FIGURE 1 is a side elevation, in cross section, of a launch tube constructed in accordance with the present invention, a load of ordnance items being shown in phantom;

FIGURE 2 is a side elevation, in cross section, of an electrically armed ordnance item in accordance with the present invention;

FIGURE 3 shows a plurality of the ordnance items of FIGURE 2 assembled as a single tube load; the electrical system mounted in the launch tube being shown for illustration;

FIGURE 4 is a showing, in cross section, of the means for coupling together a plurality of the items of FIGURE 2; and

FIGURE 5 is a showing, in cross section, of the operating mechanism of a mechanically armed ordnance item constructed in accordance with this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Launcher

The launcher is shown in FIGURE 1 and consists of a cylindrical launch tube 10 having a closure 11 at its aft end and a launch port 12 at its forward end. For exemplary purposes only, the launcher is shown and described in conjunction with a load of three ordnance items. Obviously, however, it could be designed for more or less than three. Inasmuch as the ordnance items are ejected from the launch tube by means such as ejection gasifiers or squibs, cold gas propellant, springs, or the like, the launch tube contains the hardware necessary to activate such ejection means. This system advantageously comprises a plurality Of electrical contacts 14, 15 and 16 positioned in the inside of launch tube 10 to activate each of the ejectors, one of which is associated with each ordnance item, by the application of electrical power. Contacts 14, 15 and 16 are connected to an electrical power source 17 through a selector switch 18. A fourth electrical contact 20, in communication with an electrical power source 21, is located in the mouth of launch port 12 in such a position as to engage and activate each ejection device as it passes through. The operation of this mechanism and its importance to the system will be explained below.

Launch tube 10 can be carried beneath the wing of an aircraft, with launch port 12 facing opposite to the direction of flight so that a minimum amount of force is needed to eject the ordnance items. However, the details and mounting on the aircraft and its interrelationship with the aircraft, or with any other vehicle, forms no part of this invention.

3,45 3

Electrically armed ordinance item

FIGURE 2 shows, partially in cross section, an electrically armed ordnance item 22 constructed in accordance with the present invention. This item can be a bomb, flare, sonobuoy, depth charge or the like, the invention not being restricted to any particular type of ordnance. Ordnance item 22 comprises a casing 23 of outside diameter approximately equal to the inside diameter of launch tube 10. Casing 23 encloses and holds the payload 24 and its electrically operated arming or actuating means 25. Mounted near the rear closure 26 of casing 23 is a spring contact 28 which is in electrical communication with arming or activating means 25 through a lead wire 29. Also shown are grounding wire 30 and contact 31, to complete the electrical circuit through arming means 25. Rearward of closure 26 and attached thereto is an electrically fired jettisoning charge 33, which has a spring-loaded electrical contact 34 and a grounding contact 35.

A load for the launch tube 10 consists of a plurality of identical items. These items 22 are attached together for easy, safe handling and for ease of loading into the launch tube. A load of three identical electrically armed ordnance items is shown in FIGURE 3, the electrical system mounted in launch tube 10 being shown for illustration. Each of the electrical contacts 34 of the jettisoning means 33 of item 22 is in electrical communication with one of contacts 14, 15 or 16 which are mounted in tube 10 as shown also in FIGURE 1. Selective application of electrical power to one of the ejecting means 33 will cause all of the ordnance items between it and launch port 12 to be ejected. Thus, it is possible to eject all of the items in the launch tube by firing one ejection charge.

As before stated, it is advantageous to construct a “stack” of ordnance items 22 which are releasably attached together. This can be accomplished by providing a series of connector elements on the forward end of each item, the details of one such system being shown in FIGURE 4. A connector element 40 is attached to the forward end of each of the items 22. This element 40 carries connecting studs 41 which protrude forward. The rear portion of each of the items 22 includes a connector element 43 with spring-loaded fasteners 44 which are engaged by studs 41 to hold adjacent units together. In addition, rear closure 11 of launch tube 10 also carries a connector element and associated studs, and this unit, not shown, engages the rearmost of the ordnance items when the stack is inserted into the launch tube. In addition to securing the load of items in the tube, this arrangement will cause proper alignment of the electrical contacts on the ordnance items with those mounted in the tube.

Mechanically armed ordnance item

The launch tube of FIGURE 1 can also be used with a load of ordnance items which are mechanically armed or activated. These mechanical items are similar to the electrical ones pictured in FIGURES 2 and 3 except for the fact that the arming or activating means is mechanically operated and the connector mechanism is more sophisticated. FIGURE 5 shows in detail the system for safing and arming a mechanically activated item, as well as the connection and interrelationship between adjacent items. The mechanical items each have a rear portion which includes an electrically activated ejection means 33, with associated power contact 34 and grounding contact 35. The mechanical arming or activating means comprises a plurality of bore-riding pins 52 which are biased outward by springs 53. By means of rods 54, these bore-riding pins 52 engage firing pin or trigger 55 and restrain it from movement. This condition exists when pins 52 are in their inward position, as held by the bore of launch' tube 10, for example, and firing pin 55 is engaged while in its rearward position, although biased forward by spring 56. Movement of pins 52 outward unlocks firing pin 55 so that it will strike element 57 to arm or activate the ordnance item.

Obviously, bore-rider pins 52 will be held in their inward

1,306 position and thus firing pin 55 held in a disarmed position when they are cammed by contact with the bore of launch tube 10. In order to hold pins 52 in this inward position when the stack of items is outside of the launch tube, a unique interaction between adjacent ordnance items is presented by this invention. As shown in FIGURE 5, mounted on the forward end 59 of each ordnance item are a plurality of connector pins 60. These connector pins 60 protrude through the rear portion of the forward ord, „ nance item to engage bore-rider pins 52 and lock them in the inward position. This can most advantageously be accomplished by providing a hole through each of pins 52, the respective connector pins 60 fitting into the hole. Thus, the bore-riding pins are held in the inward position even 15 when not engaging the launch tube, and the ordnance items, once assembled in an interengaging stack, are kept in a disarmed condition. The bore-rider pins of the rearmost ordnance item are engaged by connector pins mounted on a plate, not shown, which then becomes a 20 part of the ordnance load. In order to align contacts 34 of the ordnance ejecting means with power contacts 14, 15 and 16 in the tube, the rear plate in the ordnance stack can have openings to receive alignment pins mounted in the tube, in the same manner as the electrically triggered 25 items.

OPERATION

This system provides means for singular or plural launching of both electrically and mechanically armed ordnance items. Each item has an ejecting means associ³⁰ ated with it. This can, for example, be an electrically fired explosive squib. Referring now to FIGURE 1, by means of switch 18 electrical power can be supplied to any one of power contacts 14, 15 and 16. If power were applied to contact 14, the squib rearward of ordnance item A would ³⁵ fire, and item A would be ejected through port 12. Application of electrical power to contact 15 will cause the squib associated with item B to fire, and both items forward of it, A and B, will be ejected. Similarly, exploding the rearmost squib, that behind item C, results in all three items being ejected. The ejection of the mechanically armed items is accomplished in an identical manner.

In the case of both types of ordnance, a plurality of items are releasably attached together to form a single tube load. Separation is accomplished by firing each of the 45 previously unfired ejection squibs as it passes through the launch port 12. Power is applied to contact 20, mounted in the mouth of launch port 12. As each of ordnance items passes through launch port 12, the squib firing contact 34 will momentarily touch power contact 20, thus firing the 50 unexploded ejection squibs 33 and causing separation of the ordnance.

The firing of each ejection squib as the ordnance items leave the launch tube is extremely important in the case of the mechanically armed items, for these items cannot 55 be armed unless adjacent items are separated, thus removing locking pins 60 from engagement with bore-rider pins 52, allowing the latter to move outward to release the firing pin 55. If pins 60 are withdrawn while the items are still in the launch tube, the bore-rider pins 52 will cam on 60 the inside of the launch tube; still holding firing pin 55 in the unarmed position until the ordnance item leaves the tube. This invention thus provides a double safing feature which is very important, for it positively precludes arming of the ordnance item while it is still in the launch tube.

Electrically activated ordnance items are armed by means of power contact 20 as they are expelled from the launcher. Arming contact 28 is positioned in the rearmost portion of the ordnance item and, along with squib contact 34, touches power contact 20 as the ordnance item 70 leaves the launch tube, thus setting in operation the arming or activating mechanism at the last possible moment. Such arrangement holds to an absolute minimum the chances of an electrically activated item being armed while still in the launch tube.

The instant invention, therefore, presents an entirely

3,451,306 new concept for launcher and ordnance item design and interrelationship. Both electrically armed and mechanically armed ordnance items can be used with the launcher. The chances of an item becoming armed while in the launch tube are held to a minimum. In addition, the ordnance items are easily handled and are kept in an unarmed condition by being interlocked. Many modifications and variations of the invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, jq the invention may be practiced otherwise than as specifically described.