Electrical hinge connector

Field

The present invention relates to hinges that provide an electrical connection, in particular for use in aircraft electrical power systems. The invention further relates to electrical power distribution systems for aircraft.

Background

The factors governing the design of modem power distribution systems which are installed in aircraft include cost, weight and volume. To drive down the overall package size, design measures are taken which utilize every available surface and space. However general operation and maintenance access is required over the life of the part and therefore components are often mounted on a hinged door on the unit. For primary power distribution, the components mounted on the door can require current feeds up to and in excess of 500A. Such large currents require cable feeds which are bulky, heavy and inherently inflexible. As an example, some cables need to be as thick as 15mm in diameter in order to carry the required current. As a result a great deal of space is required to accommodate the excess cable which brings with it additional weight, greater opening and closing forces to operate the door, and largely unpredictable wear and tear of the cable strands which are forced to act in a manner in which they are not mechanically designed to operate.

One solution that has been proposed to overcome the problem of the amount of volume required is to allocate space in the unit to accommodate the excess cable. This however does not reduce the resistance to flex in the cable. An additional solution in the prior art has been to transmit the power across the door hinge by multiple cables in a bundle. This enables increased flexibility and therefore reduces the force required to open and close the door, however using multiple 'thinner' cables increases weight through the increased cross-sectional area of insulation and bundle retention. This also carries with it the risk of undetected faults if a wire breaks while others are connected in parallel.

<patcit id="pcit0001" dnum="DE10101635C1"><text>DE 10101635 C1</text></patcit> discloses an electrical connector for cable sections comprising a hinge.

<patcit id="pcit0002" dnum="US3860312A"><text>US-A-3860312</text></patcit> relates to a hinge generally corresponding to the preamble of claim 1 herein.

The present invention provides a hinge for an aircraft power distribution system unit, the unit having a housing comprising first and second housing parts, the hinge being according to claim 1 herein.

Advantageously, the present invention overcomes the problems associated with cable connections, because the hinge allows easy rotation of the door of the unit, requiring a low force to open and/or close the door of the unit, whilst providing an electrical connection to transmit power to the components mounted on the door within the unit. Thus, no wires are needed to transmit current from the main body of the unit to the door-mounted components. A reduction in the overall volume and weight of the aircraft power distribution system unit is made possible by the invention.

The second hinge member can be removably engagable in a cavity of the first hinge member, whereby the door of the unit can be easily plugged in and removed from the unit, without power cables restricting the motion of the door.

There follows a detailed description of embodiments of the invention by way of example only with reference to the accompanying drawings, in which: <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Fig. 1</figref> shows schematically a unit of an aircraft power distribution system according to the invention;</li><li><figref idref="f0001">Fig. 2</figref> shows first and second hinge members according to the invention;</li><li><figref idref="f0002">Fig. 3</figref> is a perspective view of a part of the hinge according to the invention;</li><li><figref idref="f0002">Fig. 4</figref> is a perspective view of a busbar connectable to the hinge part shown in <figref idref="f0002">Fig. 3</figref>;</li><li><figref idref="f0003">Fig. 5</figref> is a perspective view of a partially assembled hinge;</li><li><figref idref="f0003">Fig. 6</figref> shows an assembled hinge including the busbar shown in <figref idref="f0002">Fig. 4</figref>; and</li><li><figref idref="f0004">Figs. 7</figref> and <figref idref="f0005">8</figref> are perspective views of a unit of an aircraft power distribution system including the hinge according to the invention.</li></ul>

A unit 1 of an aircraft electrical power distribution system is shown in <figref idref="f0001">Fig. 1</figref> comprising a first housing part 3 and a second housing part 2. The second housing part 2 comprises a door rotatably connected via a hinge 4 to the first housing part 3, the first housing part comprising a main body of the unit 1. Electrical current enters the unit 1 via a power input 8, which provides power to an electrical bus 7 for distributing current to electrical loads 12 provided within the unit. Power is also transmitted from the input 8 to an electrical bus 6 that is mounted on the door 2 of the unit. In the embodiment shown, the bus 6 on the door 2 is connected to the power input 8 via the bus 7 in the unit. The hinge 4 which connects the door 2 to the main body 3 of the unit 1 comprises electrically conductive material, whereby current can be conducted to the electrical bus 6. Further, one or more electrical devices 5 are mounted on the door 2, preferably on the interior side of the door, and draw power from the bus 6, the devices being connected to corresponding power outputs 9. Where cable is used for the power outputs 9, this can be achieved using thinner, more flexible wires than those needed for the power input. Alternatively, the power output could be transmitted across a second hinge not shown in <figref idref="f0001">Fig. 1</figref>.

<figref idref="f0001">Fig. 2</figref> shows two components of the hinge 4 comprising a first hinge member and a second hinge member 10, respectively comprising a receptacle 11 and a protrusion 17 for rotatable engagement in the receptacle. The receptacle 11 comprises a hyperboloid socket having a circular cross-section and including a cylindrical cavity 13 for receiving the protrusion 17, the end portions 14 of the receptacle 11 having a greater thickness and hence an enhanced strength compared to a central part 15 of the receptacle. The second hinge member 10 can connect to the receptacle with a push-fit mechanism. In this regard, the internal structure of the hyperboloid socket 11 (not shown) includes a series of wires extending along the periphery of the cylindrical cavity 13 between the end portions 14, the end portions being twisted with respect to one another about a longitudinal axis of the socket, whereby the wires form a constriction towards the middle of the socket. The protrusion 17 of the second hinge member is cylindrical and adapted for mating insertion in the cylindrical cavity 13 of the receptacle, the longitudinal axis of the protrusion 17 coinciding with the axis of rotation of the hinge. The cylindrical surface of the protrusion 17 and the internal structure of the cavity 13 provide a reliable surface contact over a large area between the first and second hinge members thereby providing a good electrical connection between the hinge members capable of carrying the high currents required by aircraft power distribution systems. Further, the internal constriction of the socket facilitates the fixture of the protrusion within the socket. At an end of the second hinge member 10 opposed to the protrusion, the second hinge member comprises a root portion 16 for connection to a busbar 18 shown in <figref idref="f0002">Fig. 4</figref>, which supplies power to the door-mounted electrical devices 5. Both the first and second hinge members are made from electrically conductive materials, such as metals.

Referring to <figref idref="f0002">Fig. 3</figref>, the receptacle 11 of the hinge is connected to the housing by means of a mount 19 and a conductor 21 feeds current to the receptacle 11 from the bus 7. The electrical connection between the conductor bar 21 and the receptacle can be provided by means of a subsidiary connector (not shown in the drawings), which can extend through the mount 19. The mount 19 itself preferably comprises an electrically insulating material, which advantageously insulates the unit housing from the electrical current.

<figref idref="f0002">Fig. 4</figref> shows a busbar 18 which can be mounted on the door 2 of the unit and has the second hinge member 10 formed integrally therewith. In an alternative, the second hinge member is manufactured separately to the busbar 18 and is connected thereto by means of an electrically conductive joint. As shown in <figref idref="f0003">Fig. 6</figref>, the busbar 18 supplies power to the electrical devices 5 and ensures that the electrical devices 5 are firmly held in place on the inside of the door.

In <figref idref="f0003">Fig. 5</figref>, the hinge 4 is shown in a partially assembled or exploded view. The assembly of the hinge involves disposing the mount 19 on the main body of the unit 1. The receptacle 11 is inserted into a channel 22 in the mount 19 and the protrusion 17 of the second hinge member 10 is inserted into the cylindrical cavity 13 of the receptacle 11. The order in which these steps are carried out can be varied.

<figref idref="f0003">Fig. 6</figref> shows the hinge assembled, including a plurality of electrical devices 5 mounted underneath the busbar 18. For example, one or more of the electrical devices 5 may comprise circuit breakers. The busbar 18 provides the input current to the circuit breakers 5, the output current from the circuit breakers 5 being significantly lower. Thus the output current can be carried by thin, flexible wires, which can be accommodated in the unit and do not offer an excessive resistance to the opening and closing of the door 2.

<figref idref="f0004">Figs 7</figref> and <figref idref="f0005">8</figref> show an assembled unit 1 of an aircraft power distribution system. First and second busbars 18 are provided on the interior side of the door, connected respectively to first and second hinges 4. First and second conductors 21 feed current respectively to the first and second hinges 4. In <figref idref="f0004">Fig 7</figref> the unit is shown in the closed position, while in <figref idref="f0005">Fig. 8</figref>, the door of the unit is open to allow access to the components within. The hinge 4 allows for 120 degrees of door rotation, which is typically required for maintenance access. In the example shown, each hinge is capable of carrying 200A of current, allowing for 400A to be conducted across a pair of hinges. The example shown is a DC system, although the hinge can also be used in a system that runs on AC power. The power output is not shown in <figref idref="f0004">Figs 7</figref> and <figref idref="f0005">8</figref>, but again can comprise wires or an output hinge. The size and quantity of the hinges can be varied depending on the specific mechanical and electrical design considerations at hand.

The first and second hinge members can be mounted in reverse to the way shown in the Figures. In other words, the receptacle 11 can be mounted on the door 2 and the protrusion 17 on the main body 3 of the unit 1. The mount 19 is then provided on the door 2 for receiving the receptacle 11. The first and second hinge members can be manufactured by moulding from plastics materials.