Electrical connector

An electrical connector disposed between a store and an aircraft or dispenser comprises a first store-side part mechanically connected to the store and a second aircraft-side complementary part connected to an electrical cable attached to the aircraft or dispenser at a forward end, the aircraft-side part comprising a core containing electrical contacts and an outer shell engagable with the store-side part to securely retain the aircraft-side part in mating engagement with the store-side part while the store is being carried by the aircraft, the outer shell being adapted to be pulled off the store-side part as the store is separated from the aircraft, the outer shell being formed as a separate component or assembly, removably attached to the aircraft-side part core.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to Great Britain Application No. 0229347.0 filed on Dec. 17, 2002, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention concerns electrical connectors for stores to be released or ejected from an aircraft. The electrical connector must be positively and safely disconnected to avoid damage to the electrical circuit and its anchoring points on the store and aircraft or dispensing system, as the store separates from the aircraft, often at considerable relative speed. This function is normally achieved by firmly securing a first half of the connector to the store and fitting a second half of the connector at the end of a flexible cable extending from the aircraft or dispensing system. A lanyard is secured between a fixed strong point on the aircraft or dispensing system and the connector second half, so that as the store separates from the aircraft, the lanyard is tensioned and releases a spring-loaded coupling sleeve on the connector, thereby allowing the two halves to separate. The length of the lanyard is shorter than the cable, which is therefore not subjected to excessive strain as the connector halves are pulled apart.

Whilst the store remains attached to the aircraft, the connector halves must be maintained together securely to resist premature separation by vibration and aerodynamic and inertial loads. In its rest position, the coupling sleeve keeps locking balls or dogs engaged in a co-operating groove in a retaining ring which is screwed onto the connector first half, to make up the electrical connection. The known connector therefore has a screw-on, pull-off action. Under certain conditions, for example very high separation speeds, this connector can fail to separate correctly. The aircraft side (second) connector half, including the electrical contacts, conductors and insulator blocks within it, can be damaged, requiring replacement before the store can be replenished. This is a lengthy operation, needing specialist tools and facilities.

SUMMARY OF THE INVENTION

The present invention aims to mitigate or eliminate these problems and provides an electrical connector disposed in use between a store and an aircraft or dispenser, a first half of the connector being mechanically connected to one of the store or the aircraft/dispenser and a second, complementary half of the connector being connected to an electrical cable attached to the other of the store or the aircraft/dispenser, the connector second half comprising a core containing electrical contacts and an outer shell snap-engageable with the first connector half to securely retain the connector second half in mating engagement with the connector first half while the store is being carried by the aircraft/dispenser, the outer shell being pulled off the connector first half as the store is separated from the aircraft/dispenser, the outer shell being formed as a separate component or assembly, removably attached to the connector second half core. The snap-engageable connector of the invention performs well even at high separation speeds. Furthermore, even if it fails to disconnect cleanly, any resulting damage to the second half is likely to be confined to the outer shell. This is readily replaceable in the field, without disturbing the cable or its electrical connections to the core of the second connector half.

Preferably the snap-engagement is provided by a resilient finger extending axially between the first and second connector halves, the finger being attached to one of the connector halves and engageable with a detent provided on the other connector half. The finger may be attached to a ring mounted on a sleeve comprising the outer shell.

The outer shell may furthermore comprise an attachment ring rotatable about the second connector half and to which ends of a lanyard are anchored.

The outer shell may be held on the connector second half core by a threaded clamping ring.

It may also be provided with EMC shielding.

The detent may be a circumferential rib formed on a collar threadingly or otherwise connected to the connector first half.

Further preferred features and advantages of the invention may be understood from an illustrative embodiment, described below with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the Figures, which show an example of one embodiment of the invention,FIG. 1shows a connector with a first store-side part10and a second aircraft-side part12. (Store-side part10may be referred to throughout this document as first part, first half, or first connector half. Aircraft-side part12may be referred to throughout this document as second part, second half, or second connector half.) The second aircraft-side part comprises a core14containing the required electrical conductors and contacts56at a forward end52near an electric cable54. The electrical contacts56are surrounded by a barrel16having keys18for rotational alignment of the first and second parts10,12and proper registration of the electrical contacts56in them. The aircraft-side part12further comprises an attachment ring20to which ends of a lanyard22are anchored, and an outer shell50assembled from a molded sleeve28, an internally threaded clamping ring30and resilient metallic (e.g., spring steel) fingers24integrally formed with a mounting ring26.

To assemble the aircraft-side part12, as shown inFIG. 2, the attachment ring20is slid over the barrel up to a shoulder38on the core14. The attachment ring20is shown wit a lanyard22fitted. However, alternate embodiments could include an alternative cable strain relief device or interface. The next component fitted over the barrel16is mounting ring26and fingers24, which are pre-assembled on the sleeve28together with an electro-magnetic compatibility (EMC) shielding ring32. This assembly24,26,28is retained over the barrel by the clamping ring30, which is screwed onto eternal threads on the core14. Tightening the ring30clamps the sleeve28and mounting ring26against a further Shoulder40formed on the core14. The attachment ring20is thereby trapped for free rotation on the core14between the shoulder38and the mounting ring26.

The fingers are located in axial slots formed in the exterior of the sleeve28. The distal ends of the fingers are formed with inwardly extending curved tips42, received in through-going slots formed in the free end of the sleeve28. (SeeFIG. 3). The sleeve28is the main mechanical structure which provides support to the spring fingers24and the EMC shield32. The spring fingers provide the means to retain the two mating halves10,12of the connector together using their curved tips42, as further explained below. Although four fingers24are illustrated, there could be two through to eight or more, depending on the size of the connector core components to be mated. The EMC shield32is optional, depending on the overall requirements for the connector EMC performance. The type of braid which can be fitted provides a full 360° screening/bonding performance.

The clamping ring30has features (e.g. slots44,FIG. 1) that allow the ring to be hand torqued into place using a suitable tool. This completes the assembly of the aircraft-side connector at the end of the flexible cable. On the standard store connector receptacle36forming part of the first connector half, the only item which needs to be added is a detent collar34which as shown is screwed onto external threads (seeFIG. 3). Alternatively, different standard collar fittings (e.g. bayonet fittings) can be used to suit a given store connector receptacle36.

Obviously the features of the two connector halves10,12can be swapped to provide the best solution for an individual application.

The connector once assembled is simple to operate as the two halves10,12are mated by first aligning the keys18with keyways in the other connector half (where necessary) and then pushing the two halves together. As the contacts in the core14and store receptacle36engage, the spring fingers24open over a shaped rib48on the detent collar34(seeFIG. 5). As the electrical contacts mate fully home so the spring fingers spring back into position having moved over the rib48. As shown, the rib48has a curved profile to match the profile of the finger tips42. To disengage the connector, the second half12can be pulled by the attachment ring20which provides a tensile load on the core14and therefore provides the force to push apart the spring fingers42over the rib48.

The connector provides for easy and reliable mating and demating of the connector halves under extreme conditions. The connector system allows simple replacement of the mechanical retention mechanism whilst being in the field, without the need to remove electrical contacts.