WO1998005052A1

WO1998005052A1 - Modular contactor

Info

Publication number: WO1998005052A1
Application number: PCT/US1997/013176
Authority: WO
Inventors: Darin R. Morman
Original assignee: Sundstrand Corporation
Priority date: 1996-07-29
Filing date: 1997-07-28
Publication date: 1998-02-05

Abstract

A modular contactor particularly useful in an aircraft performs the function of making/breaking a main electrical circuit, the function of coordinated switching of the solenoid coil, and the function of communicating the contactor's status for a plurality of auxiliary outputs. The modular contactor includes a mounting base to which both a contactor module and an auxiliary function module are releasably mounted. The contactor module includes at least one contact for making/breaking a main electrical circuit and a sensor providing an electrical signal of the contactor's status. The auxiliary function module includes electrical circuitry for providing a plurality of auxiliary outputs communicating the contactor's status and coordinated switching of the solenoid coil. Respective electrical connectors on the contactor module and the auxiliary function module make electrical contact with one another when the modules are both releasably mounted on the mounting base for transmitting the electrical signal of the sensor of the contactor module to the circuitry in the auxiliary function module for providing a plurality of auxiliary outputs communicating the contactor's status and for transmitting the command signal through the auxiliary function module to the solenoid coil in the contactor module. Advantageously, when one function fails, only the defective module needs to be replaced or repaired. Also, this contactor offers the flexibility of providing any number of auxiliary outputs, using different auxiliary function modules, without affecting the performance or mechanical packaging of the module which performs the making/breaking of the main electrical circuit. Mechanical interfaces at auxiliary switches and the solenoid's coil transfer switch are also eliminated.

Description

MODUl ΔR CONTACTOR

Field nf Invention

The present invention is directed to an improved contactor for making/breaking a main electrical circuit, coordinated switching of the solenoid coil, and communicating a contactor's status through a plurality of auxiliary outputs. The contactor is useful in an aircraft.

Raf-kgrnnnr- anri Summary of Invention

The conventional contactor for use on an aircraft contains all the components which perform the functions of making/breaking a main electrical circuit, coordinated switching of the solenoid coil, and communicating the contactor's status through auxiliary outputs. Provisions for attaching a wiring harness to the auxiliary outputs and solenoid coil command lines and securing aircraft current-in and current-out feeder wires of the main electrical circuitry are also included as one contactor package.

One such prior art contactor 17 is illustrated in Figs. 1 -3 of the drawings. The contactor 17 is in the form of a power relay with an electrically operated, magnetically latched three-pole, single throw, plunger actuated solenoid unit 18. The solenoid unit comprises a coil 1 and a plunger 5 attached to the main actuating rod 4 which carries movable contacts 9 which are moved back and forth along the axis A-A in Fig. 2 into and out of contact with respective stationary contacts 10 in a main electrical circuit.

The relay 17 has seventeen auxiliary circuits which function to communicate the contactor's status, e.g. whether the main electrical circuit is open or closed by the contactor, through a plurality of auxiliary outputs in a connector 19. The auxiliary circuits each include auxiliary contacts 3 inside auxiliary switches 20. Both normally opened and normally closed sides of the auxiliary switches are available at the relay connector. Switch screws 12 carried by the actuator plate 6 attached to the main actuating rod 4 of the solenoid unit 18 are moved to open and close the auxiliary switches 20 by pushing or releasing the switch button 1 3 with the making/breaking of the main electrical circuit with contacts 9 and 10. In addition to the auxiliary switches 20, the relay 17 has a coil transfer switch 7 to coordinate relay trip and close action in response to the command signal from an aircraft control unit, and to remove power from the trip and close coils of coil 1 after operation.

The main electrical power connections to the relay are made by six terminal studs. Normally, electrical power is connected to terminals T1 , T2 and T3 and the power leaves the relay through terminals L1 , L2 and L3. Connections for the auxiliary switches 20 and the coil transfer switch 7 are through the pins of the connector 19.

In this conventional contactor 17, there are two operations caused by coils within the solenoid coil 1 , trip and close. Two permanent magnets 24 within the relay 1 7 supply the magnetic latch force to keep the relay in the closed or latched position. When the relay is in the open or tripped position, the main spring 21 keeps the relay open and the magnetic flux path is through the solenoid bases 25, spacers 2, and permanent magnets 24.

To close the relay, a close command signal from an aircraft control unit is applied through the coil transfer switch 7 to the close coil of coil 1 and sets up an electromagnetic flux in the same direction as the permanent magnet but through the solenoid plunger 5. This flux overcomes the force of the main spring 21 and causes the solenoid plunger 5 to move downward. Two variable air gaps, one between the plunger 5 and the plunger seat 22 and the other between the plunger ring 23 and upper base 25, decrease as the plunger 5 moves downward. The permanent magnet flux path, as the two air gaps are reduced to zero, will be through the plunger ring 23 and solenoid plunger 5 because of the lower reluctance of the plunger path. The force of the permanent magnet flux is greater than the force of the main spring 21 and will hold the relay in the closed position or latched position after the close coil current is cut off by the coil transfer switch 7. While the relay is closing the main actuator 4 attached to the solenoid plunger 5, moves downward with the plunger 5. The main actuator rod 4 pulls the movable contacts 9 down onto the fixed contacts 10 to complete the main electrical power circuits through the relay. At the same time the auxiliary switches 20 and the coil transfer switch 7 are operated by switch screws 1 2 carried by the actuator plate 6.

To trip the relay, a trip command signal from an aircraft control unit is applied through the coil transfer switch 7 to the relay trip coil in coil 1 which sets up an electromagnetic flux that opposes the permanent magnet latch flux. The electromagnetic flux reduces the force of the permanent magnet flux and energy stored in the main spring 21 causes the solenoid plunger and the main actuating rod 4 to move upward. The main actuating rod 4 pushes on the insulating bushing 14 causing the movable contacts 9 to move away from the stationary contacts 10 opening the main electrical power circuit through the relay. The auxiliary switches 20 and coil switch 7 are released as the actuator plate 6 containing the switch screws 12 moves up. As the solenoid plungers moves upward, the air gap in the plunger flux circuit will increase causing a high reluctance path. The permanent magnet flux path will be through the spacers 22, solenoid bases 25, and permanent magnets 24. When the coil transfer switch 7 is released, the coil circuit is opened removing power from the trip coil in coil 1 and the relay will be in the open position.

This conventional contactor is disadvantageous in that the contactor contains all the components which perform the functions of making/breaking the main electrical circuit, the coordinated switching of the solenoid coil, and the communication of the contactor's status through auxiliary outputs. Provision for attaching a wiring harness to the auxiliary outputs and the solenoid coil command lines at connector 19 and securing the aircraft current-in and current-out feeder wires are also included in the one contactor package. When any one of the these functions fails or the method for securing the wiring harness or current-in or current-out wires becomes worn or damaged, the entire contactor must be removed and replaced or repaired. Also, the number of auxiliary outputs varies for different aircraft applications which can require a change in the overall contactor design, performance characteristic and packaging envelope. An object of the present invention is to provide an improved contactor which avoids the aforementioned disadvantages of the prior contactor. More specifically, an object of the invention is to provide an improved contactor which utilizes the traditional way to perform the function of making/breaking the main electrical circuit but a unique way of providing coordinated switching function of the solenoid coil and a unique way of providing the function of communicating the contactor's status through auxiliary outputs with two distinct modules on a common base instead of with all functions in one package.

This new approach allows the flexibility of providing any number of auxiliary outputs without affecting the performance and packaging of the module which performs the making/breaking in the main electrical circuit. Further, when one of the functions fails, only the defective module needs to be replaced or repaired. This decreases the replacement costs since the entire contactor does not have to be replaced.

A modular contactor according to a disclosed, preferred embodiment of the present invention for performing the function of making/breaking a main electrical circuit, and the function of coordinated switching of the solenoid coil and the function of communicating the contactor's status through a plurality of auxiliary outputs, comprises a contactor module having a means for making/breaking a main electrical circuit and a sensor providing an electrical signal of the contactor's status; and an auxiliary function module including means for providing a plurality of auxiliary outputs communicating the contactor's status and means for providing coordinated switching of the solenoid coil; and wherein the module contactor includes means for releasably electrically connecting the contactor module and the auxiliary function module for transmitting the electrical signal of the sensor of the contactor module to the means for providing auxiliary inputs communicating the contactor's status and transmitting the command signal through the auxiliary function module to the solenoid coil in the contractor module. The modular contactor of the disclosed embodiment further comprises a mounting base to which the contactor module and the auxiliary function module are releasably mounted. The mounting base comprises terminals in the form of threaded studs for attaching current-in and current-out feeder wires directly to the modular contactor. The contactor module is electrically connected across the current-in and current-out terminals for making/breaking the electrical circuit through the modular contactor.

The means for releasably electrically connecting the contactor module and the auxiliary function module includes respective electrical connectors on the contactor module and the auxiliary function module which make electrical contact with one another when the modules are both releasably mounted on the mounting base. The mounting base in turn includes through holes for securing the modular contactor to a support member of an aircraft.

The auxiliary function module in the disclosed embodiment includes a connector for mating with an aircraft wiring harness for outputting the plurality of auxiliary outputs communicating the contactor's status and for receiving the solenoid coil command signal from an aircraft control unit. The means for providing the plurality of auxiliary outputs communicating the contactor's status includes a circuit board with multiplexing circuitry for providing the plurality of auxiliary outputs utilizing the electrical signal from the sensor from the contactor module. The sensor located in the contactor module generates an electrical signal which is dependent on the contactor's actuator position and sends this signal to the auxiliary function module for interpretation. The means for coordinated switching of the solenoid coil is provided by electronic switching circuitry that removes the command signal from the solenoid coil and also applies the proper electrical polarity across the solenoid coil for the next coil command signal.

Thus, a further advantage of the present invention resides in the elimination of the mechanical interface of the actuator and auxiliary switches and the mechanical interface of the actuator and coil transfer switch as in the prior art contactor referred to above. The invention requires only an electrical interface between the auxiliary function module and the contactor module, not a mechanical interrelationship. That is, the auxiliary function according to the present invention is performed electronically instead of by contacts and that function is controlled by an electrical signal from the contactor module instead of a mechanical interface. Also, the coordinated switching function according to the present invention is performed electronically in the auxiliary function module instead of a mechanical interface. The auxiliary function module also mounts to the mounting base instead of the contactor module. The means for releasably electrically contacting the contactor module and the auxiliary function module includes respective electrical connectors on the contactor module and the auxiliary function module which make electrical contact with one another when the modules are both releasably mounted on the mounting base.

The present invention is also directed to an aircraft having the improved modular contactor of the present invention connected to a support member of the aircraft by way of the mounting base.

These and other objects, features and advantages of the present invention become more apparent when taken in conjunction with the following detailed description of the disclosed embodiment of the invention illustrated in the accompanying drawings.

Brief Description of Drawing

Fig. 1 is a perspective view of a prior art contactor in the form of a power relay for an aircraft;

Fig. 2 is a cross-sectional view of the prior art contactor of Fig. 1 taken along the line ll-ll;

Fig. 3 is a cross-sectional view of the prior art contactor of Fig. 1 taken along the line Ill-Ill;

Fig. 4 is a perspective view of a modular contactor of the present invention in a assembled form mounted as a power relay on a support member of an aircraft;

Fig . 5 is a perspective view of the several modules of the contactor of Fig. 4 shown in spaced relation to one another before assembly and mounting on an aircraft; Fig . 6 is a schematic block diagram of a modular contactor of Fig. 4 depicting components of the contactor and their relationship to the auxiliary function module and the contactor module of the contactor.

Detailed Desf.riptir-n nf Disclosed Embodiment

Referring now to Figs. 4-6 of the drawings, a contactor 30 according to the present invention contains a contactor module 31 and an auxiliary function module 32 which both mount onto a common mounting base 33. The contactor module 31 performs the function of making/breaking a main electrical circuit and contains a solenoid motor 36, a position sensor 37 and main electrical contacts 38. The solenoid moves the main electrical contacts 38 by way of an actuator 45 for making/breaking the main electrical circuit which extends through the contactor module. The position sensor 37 indicates the position of the actuator and, therefore, whether the main electrical power circuit is open or closed by the solenoid operated main contacts 38. The type of sensor can be an optical sensor, a proximity sensor, Hall-effect sensor, or any other type that has an electrical output of at least two different voltage levels.

The auxiliary function module 32 contains a circuit board 39 with the necessary electronics to provide the appropriate number of auxiliary outputs from the output signal of the position sensor and the necessary solid state switching circuitry to provide the coordinated switching of the command signal to the solenoid coil. This multiplexing circuitry and solid state switching circuitry are schematically depicted in Fig. 6. The multiplexing can be done by digital or analog methods using combinations of diodes, transistors, or microprocessor means and the coordinated switching of the coil command signal can be done by field-effect transistors, bipolar transistors, silicon controlled switches or any other solid state switching means, as will be readily understood by the skilled artisan. A connector 40 which mates with aircraft wiring harness 41 is also part of the auxiliary function module 32. The modular contactor mounting base 33 contains threaded terminal studs 42 for mounting the contactor module 31 and attaching the aircraft current-in and the current- out feeder wires. Copper bus bars 47 are provided on the contactor module 31 and the bus bars 47 have apertures formed therein for receiving the terminal studs 42 in the assembled position of the contactors. The current-in and current-out feeder wires have lugs, not shown, that have an aperture for receiving the terminal studs so the feeder wire lugs will be in direct contact with the copper bus bars 47 when installed in the aircraft. Through holes 43 are provided in the mounting base 33 for mounting the contactor 30 on a support member of an aircraft 46 by suitable fasteners, not shown. Through holes 34 in contactor module 31 and through holes 35 in auxiliary function module 32 are provided for mounting the modules 31 and 32 on the mounting base 33 using suitable fasteners, not shown. When the auxiliary function module 32 gets secured to the mounting base 33, an electrical connection is also made with the contactor module via mating connectors 44 on opposed surfaces of the modules 31 and 32.

The mating connectors 44 contain electrical pins/sockets which contact one another. This electrical connection permits the output of the position sensor 37 in the contactor module 31 to reach the circuitry in the auxiliary function module 32. The connection also allows the power to the coil of the solenoid 36 in the contactor module 31 to be passed through and switched in the auxiliary function module as shown schematically in Fig. 6.

As a result of these features of the present invention, in the improved contactor of the invention and in an aircraft using the same, there is no need to focus on the relationship of the mechanical interface between the main contactor's position or status and that of all of the auxiliary switches for communicating the contactor's status through auxiliary outputs nor the mechanical interface between the main contactor's position and that of the coordinated switching of the coil in the solenoid 36 as in the prior art. The present invention eliminates the mechanical interface of auxiliary switches by using a sensor located in the contactor module to generate an electrical signal which is dependent on the contactor's actuator position. This signal is sent to the auxiliary function module for interpretation.

The contactor of the present invention requires only an electrical interface between the auxiliary function module and the contactor module, not a mechanical interrelationship. The auxiliary function module uses electronic circuitry instead of mechanical contacts for auxiliaries and coil switching. By separating the function of making/breaking the main electrical circuit and the functions of communication of the contactor's status through auxiliary outputs and coordinated coil switching in respective ones of the two modules 31 and 32 mounted on a common base, when one function fails, only the defective module needs to be replaced. This arrangement also offers the flexibility of providing any number of auxiliary outputs without affecting the performance and packaging of the module which performs the making/breaking of the main electrical circuit. The present invention thus provides an improved contactor in an aircraft employing the same which overcomes the aforementioned disadvantages of the prior art contactor.

While I have shown and described a single embodiment in accordance with the present invention, certain aspects of the invention are not limited to the particular details of the example illustrated and it is therefore contemplated that other modifications or applications will occur to those skilled in the art. It is accordingly intended that the claims shall cover all such modifications and applications as do not depart from the true spirit and script of the invention.

Claims

CLAIMS I Claim:

1. A modular contactor for performing the function of making/breaking a main electrical circuit, the function of coordinated switching of a solenoid coil thereof in response to an aircraft command signal and the function of communicating the contactor's status through a plurality of auxiliary outputs, said modular contactor comprising: a contactor module comprising means for making/breaking a main electrical circuit and a sensor providing an electrical signal of the contactor's status; an auxiliary function module comprising means for providing a plurality of auxiliary outputs communicating the contactor's status and a means for coordinated switching of the solenoid coil; wherein said modular contactor includes means for releasably electrically connecting said contactor module and said auxiliary function module for transmitting said electrical signal of said sensor of said contactor module to said means for providing a plurality of auxiliary outputs communicating the contactor's status; and wherein the said modular contactor includes means for releasably electrically connecting said contactor module and said auxiliary function module for transmitting said command signal through said auxiliary function module to said solenoid coil of said contactor module.

2. The modular contactor according to claim 1 , further comprising a mounting base to which both of said contactor module and said auxiliary function module are releasably mounted .

3. The modular contactor according to claim 2, wherein said mounting base comprises terminals for attaching current-in and current-out feeder wires directly to said modular contactor, said contactor module being electrically connected across said current-in and current-out terminals for making/breaking the main electrical circuit through said modular contactor.

4. The modular contactor according to claim 3, wherein said terminals are in the form of terminal studs on respective sides of an opening on said mounting base which receives a portion of said contactor module mounted thereon.

5. The modular contactor according to claim 2, wherein said means for releasably electrically connecting said contactor module and said auxiliary function module includes respective electrical connectors on said contactor module and said auxiliary function module which make electrical contact with one another when said modules are both releasably mounted on said mounting base.

6. The modular contactor according to claim 2, wherein said mounting base includes through holes for securing the modular contactor to an aircraft.

7. The modular contactor according to claim 1 , wherein said auxiliary function module includes a connector for mating with an aircraft wiring harness for outputting said plurality of auxiliary outputs communicating the contactor's status.

8. The modular contactor according to claim 1 , wherein said means for providing a plurality of auxiliary outputs communicating the contactor's status includes a circuit board with multiplexing circuitry for providing said plurality of auxiliary outputs utilizing said electrical signal from said sensor of said contactor module.

9. The modular contactor according to claim 1 , wherein said means for making/breaking a main electrical circuit includes at least one main contact and an electromagnetically operated actuator for moving said main contact to make/break said main electrical circuit.

10. In an aircraft comprising a contactor containing at least one contact for making/breaking a main electrical circuit and a plurality of auxiliary outputs communicating the contactor's status, the improvement comprising said contactor being formed of a plurality of modules which can be separated from one another, including a contactor module comprising means for making/breaking a main electrical circuit and a sensor providing an electrical signal of the contactor's status, and an auxiliary function module comprising means for providing a plurality of auxiliary outputs communicating the contactor's status, and wherein said contactor includes means for releasably electrically connecting said contactor module and said auxiliary function module for transmitting said electrical signal of said sensor of said contactor module to said means for providing a plurality of auxiliary outputs communicating the contactor's status.

1 1 . The aircraft according to claim 10, wherein said contactor further comprises a mounting base connected to a support member of said aircraft both said contactor module and said auxiliary function module being releasably mounted on said aircraft base.

12. The aircraft according to claim 1 1 , wherein said mounting base comprises terminals for attaching current-in and current-out feeder wires directly to said contactor, said contactor module being electrically connected across said current-in and current-out terminals for making/breaking the main electrical circuit through said contactor.

13. The aircraft according to claim 12, wherein said terminals are in the form of studs on respective sides of an opening in said mounting base which receives a portion of said contactor module mounted thereon.

14. The aircraft according to claim 1 2, wherein said means for releasably electrically connecting said contactor module and said auxiliary function module includes respective electrical connectors on said contactor module and said auxiliary function module which make electrical contact with one another when said modules are releasably mounted on said mounting base.

15. The aircraft according to claim 12, wherein said mounting base includes through holes and fasteners therethrough for connecting the contactor to said support member of said aircraft.

16. The aircraft according to claim 10, wherein said auxiliary function module includes a connector for mating with an aircraft wiring harness for outputting said plurality of said auxiliary outputs communicating the contactor's status.

17. The aircraft according to claim 10, wherein said means for providing a plurality of auxiliary outputs communicating the contactor's status includes a circuit board with multiplexing circuitry for providing said plurality of the auxiliary outputs utilizing said electrical signal from said sensor of said contactor module.

18. The aircraft according to claim 10, wherein said contactor module further comprises a solenoid operated actuator for moving said at least one contact for making/breaking said main electrical circuit.