Patent Description:
The present standard for high amperage relays or contactors is to have a single linear motor actuator with an armature mechanically connected to movable electrical contacts by way of a shaft assembly. The armature and the shaft assembly are supported only on the side of the motor and the movable electrical contacts are provided on a free, unsupported end of the shaft assembly.

The single linear motor actuator includes a stator with a coil winding or windings. The armature passes through the single linear motor actuator structure on bushings and with linkages, including springs and other similar features, on the end of the shaft assembly, which is provided as a cantilever structure, and which is connected to the movable electrical contacts.

As amperage increases in power levels to <NUM>'s of amperes at steady state (the present aerospace production component high amperage is around 450A), the electrical connections have to significantly increase in size in order to handle the amperage power flow. As such, the electrical movable contact masses (i.e., combined mechanical and electrical elements are increased. With the high mass electrical movable contacts provided on the free end of a shaft assembly, the armature, the shaft assembly and the electrical movable contacts become mechanically difficult to hold in vibratory modes and to move to achieve high speed switching. Relay contactors are disclosed in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

According to an aspect of the disclosure, a relay contactor is provided as defined in claim <NUM>.

In accordance with additional or alternative embodiments, a housing houses the input and output leads, the shaft assembly, the actuator and the first and second bearing assemblies.

In accordance with additional or alternative embodiments, the input and output leads include first and second conductive elements, respectively, and the plate includes third and fourth conductive elements that are disposed to contact the first and second conductive elements, respectively, when the shaft and the plate are moved into the closed position.

In accordance with additional or alternative embodiments, the shaft extends through a space defined between the input and output leads, the actuator and the first bearing assembly are disposed on a first side of the input and output leads and the plate and the second bearing assembly are disposed on a second side of the input and output leads.

In accordance with additional or alternative embodiments, the elastic element is anchored at opposite ends thereof to the actuator and the shaft or the plate.

In accordance with additional or alternative embodiments, the actuator includes a linear actuator.

In accordance with additional or alternative embodiments, the actuator includes an armature through which the shaft extends, coils surrounding the armature and an actuator housing supportive of the first bearing assembly and configured to house the armature and the coils.

In accordance with additional or alternative embodiments, the first and second actuators are independently or dependently operable.

In accordance with additional or alternative embodiments, the first and second actuators each include a linear actuator.

In accordance with additional or alternative embodiments, the first actuator includes a first armature through which the shaft extends, first coils surrounding the first armature and a first actuator housing supportive of the first bearing assembly and configured to house the first armature and the first coils and the second actuator includes a second armature through which the shaft extends, second coils surrounding the second armature and a second actuator housing supportive of the second bearing assembly and configured to house the second armature and the second coils.

In accordance with additional or alternative embodiments, the first position is characterized in that the plate is displaced from the first pair of the input and output leads and in contact with the second pair of the input and output leads and the second position is characterized in that the plate is displaced from the second pair of the input and output leads and in contact with the first pair of the input and output leads.

In accordance with additional or alternative embodiments, the first position is characterized in that the plate is displaced from the first and second pairs of the input and output leads and the second position is characterized in that the plate is in contact with the first and second pairs of the input and output leads.

While a single linear actuator motor is now provided as an industry standard, it is characterized as having movable electrical contacts at a free, unsupported end of a shaft with high masses to handle the high power requirements of aerospace applications. This leads to the armature and the shaft being difficult to move during high-speed switching and to the armature and shaft having a tendency to vibrate. Thus, as will be described below, a linear motor design is provided in which the armature is supported on both ends of the shaft. In an exemplary case, a contactor or a large relay actuator system is provided with moveable electrical contacts between two or dual separate linear motor coil actuator assemblies, so that the actuator armature and shaft system is mechanically supported on both ends. This dual motor actuator configuration can allow the armature, springs, insulators and sliding bearings to be configured to optimize the movable structure for large electrical conductors (high amperage) in high vibration environments.

With reference to <FIG> and <FIG>, an aircraft power distribution system <NUM> includes a primary power distribution box <NUM> that receives power from a generator <NUM> through power leads <NUM>. The primary power distribution box <NUM> provides power through supply leads <NUM> to a secondary power distribution box <NUM>, which distributes power to first and second loads <NUM> and <NUM>, for example.

The primary power distribution box <NUM> includes a board <NUM> that is arranged within a housing <NUM>. The board <NUM> supports plug-in pins <NUM> that are connected to the power leads <NUM>. Mechanical contactors <NUM> act as switches to selectively electrically connect the power leads <NUM> to the supply leads <NUM>. Circuit breakers <NUM> are supported by the board <NUM> to selectively disconnect the supply leads <NUM> from power in response to an overload. The board <NUM> also supports a connector <NUM> that communicates with a control <NUM> through a harness <NUM>. The control <NUM> provides commands to the board <NUM> and/or a secondary circuit board <NUM> and receives feedback regarding various functions related to the aircraft power distribution system <NUM>. The secondary circuit board <NUM> is mounted on the board <NUM> and is connected to the connector <NUM> and contactors <NUM> through connections <NUM>. The secondary circuit board <NUM> includes protection circuitry <NUM> and secondary power distribution circuitry <NUM>. The protection circuitry <NUM> monitors the current provided by the generator <NUM>, for example, to prevent the secondary power distribution box <NUM> from exposure to undesired currents. The secondary power distribution circuitry <NUM> commands the contactors <NUM> between open and closed positions.

The contactors <NUM> are illustrated with control traces <NUM> and power traces <NUM> which are supported by the board <NUM> and connected to the secondary circuit board <NUM> and secondary power distribution connectors <NUM>, respectively. The board <NUM> is relatively thick to accommodate the current flowing through the power traces <NUM>. The contactors <NUM> are connected to the plug-in pins <NUM> by first bands <NUM> and second bands (not shown). The power traces <NUM> are selectively provided with power when a plate <NUM> is moved into a closed position connecting first and second contacts. The plate <NUM> is moved between open and closed positions by a linear motor and shaft assembly to be described below. The linear motor and shaft assembly is mounted to the board <NUM> and is commanded by the secondary power distribution circuitry <NUM> through the control traces <NUM>. The current flowing through the power traces <NUM> is monitored by the protection circuitry <NUM> through the control traces <NUM>.

With reference to <FIG>, a relay contactor <NUM> is provided for use in or as the contactors <NUM> of <FIG> and <FIG>. As shown in <FIG>, the relay contactor <NUM> includes an input lead <NUM> that is configured to carry current supplied from the power leads <NUM> of <FIG>, an output lead <NUM> that is configured to carry current to the power traces <NUM> of <FIG>, a shaft assembly <NUM>, first and second actuators <NUM> and <NUM> and first and second bearing assemblies <NUM> and <NUM>. The relay contactor <NUM> may further include a housing <NUM>, which is configured to house respectively portions of the input lead <NUM> and the output lead <NUM>, the shaft assembly <NUM>, the first and second actuators <NUM> and <NUM> and the first and second bearing assemblies <NUM> and <NUM>.

The input lead <NUM> includes an electrically conductive body that extends to an exterior of the housing <NUM> and a first electrical contact <NUM> at a proximal end of the electrically conductive body within the housing <NUM>. The output lead <NUM> includes an electrically conductive body that extends to an exterior of the housing <NUM> and a second electrical contact <NUM> at a proximal end of the electrically conductive body within the housing <NUM>.

The shaft assembly <NUM> includes a shaft <NUM> that can span the housing <NUM>, a plate <NUM> that is disposed on the shaft <NUM>, shaft isolation sleeve <NUM> that is interposed between the shaft <NUM> and the plate <NUM> and an elastic element <NUM>. The plate <NUM> includes an electrically conductive body and third and fourth electrical contacts <NUM> and <NUM> at opposite ends of the electrically conductive body. The shaft <NUM> and the plate <NUM> are movable together along a longitudinal axis of the shaft <NUM> between an open position and a closed position. At the open position, the third and fourth electrical contacts <NUM> and <NUM> of the plate <NUM> are displaced from electrical contact with the first electrical contact <NUM> of the input lead <NUM> and from electrical contact with second electrical contact <NUM> of the output lead <NUM>, respectively, such that the input lead <NUM> and the output lead <NUM> are not electrically communicative with one another (i.e., current from the power leads <NUM> is not transmitted to the power traces <NUM>). At the closed position, the third and fourth electrical contacts <NUM> and <NUM> of the plate <NUM> are disposed in electrical contact with the first electrical contact <NUM> of the input lead <NUM> and in electrical contact with second electrical contact <NUM> of the output lead <NUM>, respectively, such that the input lead <NUM> and the output lead <NUM> are electrically communicative (i.e., current from the power leads <NUM> is transmitted to the power traces <NUM>). The shaft isolation sleeve <NUM> serves to electrically insulate or isolate the plate <NUM> from the shaft <NUM>. The elastic element <NUM> can be disposed to apply a bias to the shaft <NUM> and the plate <NUM> which urges the shaft <NUM> and the plate <NUM> toward assumption of the open position.

In accordance with embodiments, the first and second electrical contacts <NUM> and <NUM> and the third and fourth electrical contacts <NUM> and <NUM> can be hemispherical or otherwise curved, flat-faced or otherwise configured to form reliable electrical contacts.

The first actuator <NUM> is coupled to the shaft <NUM> at a first side <NUM> of the plate <NUM>. The second actuator <NUM> is coupled to the shaft <NUM> at a second side <NUM> of the plate <NUM>. The first and second actuators <NUM> and <NUM> are configured to be independently or dependently operable so as to selectively move the shaft <NUM> and the plate <NUM> into the closed position in opposition to bias applied by the elastic element <NUM>.

In accordance with embodiments, the first actuator <NUM> may include or be provided as a linear actuator. In this or other cases, the first actuator <NUM> may include a first armature <NUM> through which the shaft <NUM> extends, first coils <NUM> surrounding the first armature <NUM> and a first actuator housing <NUM> that is supportive of the first bearing assembly <NUM> and configured to house the first armature <NUM> and the first coils <NUM>. In accordance with similar embodiments, the second actuator <NUM> may include or be provided as a linear actuator. In this or other cases, the second actuator <NUM> may include a second armature <NUM> through which the shaft <NUM> extends, second coils <NUM> surrounding the second armature <NUM> and a second actuator housing <NUM> that is supportive of the second bearing assembly <NUM> and configured to house the second armature <NUM> and the second coils <NUM>.

Electrical insulation (isolation) of the plate <NUM> from the shaft assembly <NUM> can be achieved, for example, by material selection of the shaft isolation sleeve <NUM>.

With the first and second actuators <NUM> and <NUM> configured as described above, the first bearing assembly <NUM> is disposed to movably support the shaft <NUM> at the first side <NUM> of the plate <NUM> and the second bearing assembly <NUM> is disposed to movably support the <NUM> shaft at the second side <NUM> of the plate <NUM>. The first bearing assembly <NUM> can include bearing elements that are secured in the first actuator housing <NUM> to permit movements of the shaft <NUM> along the longitudinal axis of the shaft <NUM> and the second bearing assembly can include bearing elements that are secured in the second actuator housing <NUM> to permit the movement of the shaft along the longitudinal axis of the shaft <NUM>.

As shown in <FIG>, the proximal ends of the electrically conductive bodies of the input and output leads <NUM> and <NUM> define or form a space or opening through which the shaft <NUM> extends, the first actuator <NUM> and the first bearing assembly <NUM> are disposed on a first side of the input and output leads <NUM> and <NUM> and the plate <NUM>, the second actuator <NUM> and the second bearing assembly <NUM> are disposed on a second side of the input and output leads <NUM> and <NUM>. In addition, as shown in <FIG>, the elastic element <NUM> can include a first elastic element <NUM>, which is anchored at opposite ends thereof to the first actuator <NUM> and the shaft <NUM>, and a second elastic element <NUM>, which is anchored at opposite ends thereof to the second actuator <NUM> and the shaft <NUM> or the plate <NUM>.

During an operation of the relay contactor <NUM>, the first and second coils <NUM> and <NUM> of the first and second actuators <NUM> and <NUM> can be independently or dependently energized to thus generate magnetic flux which brings the shaft <NUM> and the plate <NUM> into the closed position in opposition to the bias applied by the elastic element <NUM>. To this end, the first and second coils <NUM> and <NUM> can be disposed in parallel or in series within an energization circuit and the elastic element <NUM> can be optimized for use with the various components of the first and second actuators <NUM> and <NUM>.

Although <FIG> has been illustrated with first and second actuators <NUM> and <NUM>, it is to be understood that this is not required. For example, certain embodiments exist in which the second actuator <NUM> is not included in the relay contactor <NUM>. In these or other cases, the second bearing assembly <NUM> could include bearing elements that are secured to the housing <NUM> at the second side <NUM> of the plate <NUM> and the second elastic element <NUM> could be anchored at the opposite ends thereof to the housing <NUM> and the shaft <NUM> or the plate <NUM>.

The elastic elements <NUM> and <NUM> can be electrically isolated from the plate <NUM> by the shaft isolation sleeve <NUM>.

With reference to <FIG>, the relay contactor <NUM> is illustrated in accordance with alternative embodiments in which the first and second electrical contacts <NUM> and <NUM> and the third and fourth electrical contacts <NUM> and <NUM> are disposed at an angle with respect to the longitudinal axis of the shaft <NUM>.

With reference to <FIG> and <FIG>, the relay contactor <NUM> is illustrated in accordance with alternative embodiments in which the input and output leads <NUM> and <NUM> are provided as first and second pairs of input and output leads <NUM> and <NUM> and <NUM>' and <NUM>' and the shaft <NUM> and the plate <NUM> are movable between first and second positions at which the plate <NUM> is positioned at first and second positions with respect to the first and second pairs of the input and output leads <NUM> and <NUM> and <NUM>' and <NUM>'. As shown in <FIG>, the first position is characterized in that the plate <NUM>, which has additional third and fourth electrical contacts <NUM>' and <NUM>', is displaced from the first pair of the input and output leads <NUM> and <NUM> and in electrical contact with the second pair of the input and output leads <NUM>' and <NUM>' and the second position is characterized in that the plate <NUM> is displaced from the second pair of the input and output leads <NUM>' and <NUM>' and in electrical contact with the first pair of the input and output leads <NUM> and <NUM> (i.e., one of the first and second pairs of input and output leads <NUM> and <NUM> is normally open and the other of the first and second pairs of input and output leads <NUM>' and <NUM>' is normally closed). As shown in <FIG>, the first position is characterized in that the plate <NUM> is displaced from the first and second pairs of the input and output leads <NUM> and <NUM> and <NUM>' and <NUM>' and the second position is characterized in that the plate <NUM> is in electrical contact with the first and second pairs of the input and output leads <NUM> and <NUM> and <NUM>' and <NUM>' (i.e., both the first and second pairs of input and output leads <NUM> and <NUM> and <NUM>' and <NUM>' are either normally open or closed).

Technical effects and benefits of the features described herein are the provision of a dual linear motor actuator with a compact size, capacity to handle heavy movable electrical contracts for small motor assemblies and a spring system optimized for an armature structure, electrical conductive material mass and dual coil (motor) power.

Claim 1:
A relay contactor, comprising:
input and output leads (<NUM>,<NUM>);
a shaft assembly (<NUM>) comprising a shaft (<NUM>), a plate (<NUM>) disposed on the shaft and an elastic element (<NUM>), the shaft and the plate being movable between an open position at which the plate is displaced from the input and output leads and a closed position at which the plate contacts the input and output leads;
first and second actuators (<NUM>, <NUM>) coupled to the shaft at a first side and a second side of the plate, respectively, characterized by
the elastic element anchored at opposite ends thereof to the first vactuator and the plate respectively, the first and second actuators being configured to selectively move the shaft and the plate into the closed position in opposition to bias applied by the elastic element; and
first and second bearing assemblies (<NUM>,<NUM>) disposed to movably support the shaft at the first side and at a second side of the plate, respectively,
wherein the elastic element comprises:
a first elastic element (<NUM>) anchored at opposite ends thereof to the first actuator and the shaft; and
a second elastic element (<NUM>) anchored at opposite ends thereof to the second actuator (<NUM>) and the plate.