Contactor with multi-gap actuator

Abstract

The contactor (100) comprises a housing (110) having a cavity (112), a fixed contact (120) received in the cavity, and a movable contact (122) movable within the cavity to engage and disengage from the fixed contact. The movable contact electrically connects the fixed contact in an engaged position. When the movable contact disengages from the fixed contact, an abutment gap (230) is formed between the movable contact and the fixed contact. The contactor comprises an actuator (202) operatively coupled to the movable contact to move the movable contact within the cavity relative to the fixed contact. The actuator includes a primary coil assembly (204) and a secondary coil assembly (206). The primary coil assembly is operable to move the movable contact. The secondary coil assembly is operable independently of the primary coil assembly to vary a length of the abutment gap.

Description

[Technical field]

[0001] The subject matter herein relates generally to high power electrical contactors.

[0002] Certain electrical applications, such as HVAC, power sources, locomotives, elevator controls, motor controls, aerospace applications, hybrid electric vehicles, fuel cell vehicles, and charging systems, use electrical contactors with normally open (or separated) contacts. The contacts are closed (or mated) to provide power to a particular device. When the contactor receives an electrical signal, it is energized to introduce a magnetic field that drives the moving contact to mate with the fixed contact. The travel length of the moving contact affects the closing time of the circuit. A long closing stroke makes the contactor less responsive. However, a short closing stroke can cause damage to the contacts, such as arcing or welding between the moving and fixed contacts due to insufficient gap between them, especially when carrying high currents. Summary of the Invention [Problem to be solved by the invention]

[0003] What is needed is a contactor that overcomes the above problems and addresses other concerns found in the prior art. [Means for solving the problem]

[0004] A solution is provided by a contactor comprising a housing having a cavity. The contactor comprises a fixed contact received in the cavity. The fixed contact has an abutment end in the cavity. The contactor comprises a movable contact movable within the cavity to abut and unmate with the fixed contact. In the abutting position, the movable contact electrically connects the fixed contact. When the movable contact disengages from the fixed contact, an abutment gap is formed between the movable contact and the fixed contact. The contactor comprises an actuator operatively coupled to the movable contact to move the movable contact within the cavity relative to the fixed contact. The actuator includes a primary coil assembly and a secondary coil assembly. The primary coil assembly is operable to move the movable contact, and the secondary coil assembly is operable independently from the primary coil assembly to vary the length of the abutment gap.

[0005] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view of a contactor in accordance with an exemplary embodiment. [Diagram 2] FIG. 2 is a top view of a contactor in accordance with an exemplary embodiment. [Diagram 3] 1 is a cross-sectional view of a contactor according to an exemplary embodiment. [Figure 4] 1 is an enlarged view of a portion of a contactor according to an example embodiment showing a first coil assembly coupled to a second coil assembly; [Diagram 5] 1 is an enlarged view of a portion of a contactor according to an exemplary embodiment showing a first coil assembly and a second coil assembly. [Figure 6] FIG. 2 is a cross-sectional view of a contactor showing a primary coil assembly and a secondary coil assembly according to an exemplary embodiment. [Figure 7] FIG. 2 is a cross-sectional view of a contactor showing a primary coil assembly and a secondary coil assembly according to an exemplary embodiment. [Figure 8] FIG. 2 is a cross-sectional view of a contactor showing a primary coil assembly and a secondary coil assembly according to an exemplary embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] In one embodiment, a contactor is provided, the contactor comprising a housing having a cavity. The contactor comprises a fixed contact received in the cavity. The fixed contact has an abutment end in the cavity. The contactor comprises a movable contact movable within the cavity to abut and disengage from the fixed contact. The movable contact electrically connects the fixed contact in the abutting position. When the movable contact disengages from the fixed contact, an abutment gap is formed between the movable contact and the fixed contact. The contactor comprises an actuator operatively coupled to the movable contact to move the movable contact within the cavity relative to the fixed contact. The actuator includes a primary coil assembly and a secondary coil assembly. The primary coil assembly is operable to move the movable contact, and the secondary coil assembly is operable independently from the primary coil assembly to vary the length of the abutment gap.

[0008] In another embodiment, a contactor is provided, the contactor comprising a housing having a cavity. The contactor comprises a fixed contact received in the cavity. The fixed contact has an abutting end in the cavity. The contactor comprises a movable contact movable within the cavity to abut and disengage from the fixed contact. The movable contact electrically connects the fixed contact in the abutting position. When the movable contact disengages from the fixed contact, an abutment gap is formed between the movable contact and the fixed contact. The contactor comprises an actuator operatively coupled to the movable contact to move the movable contact within the cavity relative to the fixed contact. The actuator includes a primary coil assembly and a secondary coil assembly. The primary coil assembly includes a primary core and a primary coil forming a first electromagnet. The primary coil assembly includes a primary armature that holds a primary plunger. The primary plunger is coupled to the movable contact to move the movable contact. The primary armature is movable to move the primary plunger and the movable contact relative to the fixed contact upon operation of the first electromagnet. The secondary coil assembly includes a secondary core and a secondary coil that form a second electromagnet. The secondary coil assembly includes a secondary armature that holds a secondary plunger. The secondary plunger is coupled to the primary plunger. The secondary armature is movable to move the secondary plunger upon operation of the second electromagnet, and the secondary coil assembly is operable independently of the primary coil assembly to vary the length of the abutment gap by moving a position of the secondary plunger relative to the fixed contact.

[0009] In a further embodiment, a contactor is provided, the contactor comprising a housing having a cavity. The contactor comprises a fixed contact received in the cavity. The fixed contact has an abutment end in the cavity. The contactor comprises a movable contact movable within the cavity to abut and disengage from the fixed contact. The movable contact electrically connects the fixed contact in the abutting position. When the movable contact disengages from the fixed contact, an abutment gap is formed between the movable contact and the fixed contact. The contactor comprises an actuator operatively coupled to the movable contact to move the movable contact within the cavity relative to the fixed contact. The actuator is operable in a short gap mode and an extended gap mode, the abutment gap having a first length in the short gap mode and the abutment gap having a second length in the extended gap mode, the first length being shorter than the second length.

[0010] FIG 1 is a perspective view of a contactor 100 according to an exemplary embodiment. FIG 2 is a top view of the contactor 100 according to an exemplary embodiment. The contactor 100 is an electrical switch or relay that safely connects and disconnects one or more electrical circuits to protect the flow of power through a system. The contactor 100 can be used in a variety of applications, such as HVAC, power sources, locomotives, elevator control, motor control, aerospace applications, hybrid electric vehicles, fuel cell vehicles, charging systems, and the like.

[0011] The contactor 100 includes a housing 110 having a cavity 112. In various embodiments, the housing 110 may be a multi-piece housing. The housing 110 includes a base 114 and a header 116 extending from the base 114. Optionally, the base 114 may be configured to couple to another component. For example, the base 114 may include a mounting bracket for securing the contactor 100 to another component. In the illustrated embodiment, the header 116 is located above the base 114, but in alternative embodiments, the housing 110 may have other orientations. The housing 110 includes a cover 118 for closing the cavity 112. For example, the cover 118 may be coupled to the top of the header 116. Optionally, the cover 118 may be sealed to the header 116. In various embodiments, the cover 118 is coupled to the housing 110 to seal the cavity 112.

[0012] The contactor 100 includes a stationary contact 120 received in the cavity 112 and a movable contact 122 (FIG. 3) movable within the cavity 112 between an engaged position and a disengaged position. In the engaged position, the movable contact 122 engages with the stationary contact 120 to electrically connect the stationary contacts 120 to form a main circuit. The main circuit is opened or closed by the movable contact 122 (e.g., open in the disengaged position and closed in the engaged position). In the illustrated embodiment, the contactor 100 includes a first stationary contact 120 and a second stationary contact 120, although in alternative embodiments, the contactor 100 may include more or less stationary contacts. The stationary contacts 120 are fixed to the housing 110. For example, the fixed contacts 120 may be coupled to the header 116 and / or the cover 118. In various other embodiments, the fixed contacts 120 may be coupled to an insert or contact holder that is inserted into the cavity 112. In the illustrated embodiment, the fixed contacts 120 are post contacts. However, in alternative embodiments, other types of contacts may be provided, such as pads or tabs. In the illustrated embodiment, the fixed contacts 120 are provided on the top of the contactor 100. However, in alternative embodiments, the fixed contacts 120 may be provided in other locations.

[0013] In an exemplary embodiment, the contactor 100 includes a control system 200 for controlling the operation of the contactor 100. The control system 200 controls the switching of a main circuit. The control system 200 controls the movement of the movable contact 122 between an open position and a closed position. In an exemplary embodiment, the control system 200 includes an actuator 202 (shown in phantom in FIG. 1 ) for actuating or moving the movable contact 122. In various embodiments, the actuator 202 includes an electromagnet for operating a switch. In an exemplary embodiment, the actuator 202 includes multiple electromagnets independently operable to control the operation of the contactor 100. For example, a first electromagnet can operate independently from a second electromagnet. The electromagnets are independently operable for different modes of operation. For example, the actuator 202 can be operated in a first mode for normal operation, in a second mode for safety operation such as when transmitting high current, and in a third mode for repair operation such as to break a weld when the movable contact sticks to the fixed contact. The actuator 202 can vary the abutment gap between the movable contact 122 and the fixed contact 120 between the various modes, for example increasing or decreasing the abutment gap to vary the switching time when closing the movable contact 122 or to enhance the circuit interruption performance. The control system 200 includes control wires 210 for sending control signals to the contactor 100.

[0014] 3 is a cross-sectional view of the contactor 100 according to an exemplary embodiment. FIG. 3 shows the contacts 120, 122 and the actuator 202 in the cavity 112 of the housing 110. A cover 118 is coupled to the top of the housing 110 to close and seal the cavity 112. The stationary contact 120 extends through the cover 118 to the exterior of the housing 110.

[0015] Each of the fixed contacts 120 includes a termination portion 130 and a mating end 132. The termination portion 130 is configured to terminate to another component, such as a wire or terminal, e.g., a line-in wire or a line-out wire. In an exemplary embodiment, the termination portion 130 is exposed on the exterior of the contactor 100 for termination to another component. The termination portion 130 may be threaded to receive a nut. In the illustrated embodiment, the termination portion 130 extends through and is disposed above the cover 118. The mating end 132 is disposed within the cavity 112 for mating engagement with the movable contact 122, such as when the contactor 100 is energized. In the illustrated embodiment, the mating end 132 is generally flat for contacting the movable contact 122. However, in alternative embodiments, the abutment end 132 may have other shapes, such as a circular shape, and may form an abutment ridge on the abutment end 132 for abutting the movable contact 122 .

[0016] In various embodiments, the contactor 100 can include an arc suppressor (not shown) for suppressing an electrical arc in the electrical circuit. The arc suppressor can be disposed in the cavity 112 of the housing 110. The arc suppressor can include a magnet that creates a magnetic field for suppressing an arc created between the movable contact 122 and the fixed contact 120. In various embodiments, the cavity 112 can be sealed and filled with an inert gas for arc suppression.

[0017] The actuator 202 is disposed in the cavity 112 and is used to actuate or move the movable contact 122. In an exemplary embodiment, the actuator 202 includes a first coil assembly 204 (hereinafter also referred to as a primary coil assembly 204) and a second coil assembly 206 (hereinafter also referred to as a secondary coil assembly 206) for operating a switch. The primary coil assembly 204 and the secondary coil assembly 206 are independently operable to control switching of the movable contact 122. The primary coil assembly 204 and the secondary coil assembly 206 are independently operable for different modes of operation. In an exemplary embodiment, the primary coil assembly 204 is operable to move the movable contact 122. The secondary coil assembly 206 operates to change the position of components of the primary coil assembly 204, for example, to change the abutment gap between the movable contact 122 and the fixed contact 120. In the illustrated embodiment, the coil assemblies 204, 206 are stacked in the cavity 112 with a wall 208 therebetween. For example, the primary coil assembly 204 can be positioned above the secondary coil assembly 206, for example, closer to the fixed contact 120.

[0018] The primary coil assembly 204 includes a primary winding or coil 300 wound around a primary core 302 to form a first electromagnet 304. The primary coil assembly 204 includes a primary armature 306 received in a primary sleeve 308. The primary coil assembly 204 includes a primary plunger 310 coupled to the primary armature 306. A primary return spring 320 surrounds the primary plunger 310. In operation, the primary coil 300 is energized to create a magnetic field. When the primary electromagnet 304 is activated, the primary armature 306 moves the primary plunger 310 forward, such as in an up actuation direction, and thus moves the movable contact 122 in an advance direction. When the primary electromagnet 304 is de-energized, the primary return spring 320 returns the primary armature 306, thus forcing the primary plunger 310 and the movable contact 122 back in a return direction (e.g., downwards) to disengage the movable contact 122 from the fixed contact 120 and open the main circuit.

[0019] The primary plunger 310 extends between a first end 312 and a second end 314. In the illustrated embodiment, the first end 312 is the top of the primary plunger 310 and the second end 314 is the bottom of the primary plunger 310. However, in alternative embodiments, other orientations are possible. The movable contact 122 is coupled to the primary plunger 310 at the first end 312. For example, the primary plunger 310 extends through a central opening in the movable contact 122. A first retainer clip 322 is coupled to the primary plunger 310 at the first end 312. The first retainer clip 322 holds the movable contact 122 to the first end 312 of the primary plunger 310. A retention spring 324 surrounds the primary plunger 310 and is held to the primary plunger 310 by a retainer clip 326. The retention spring 324 engages the movable contact 122 and holds the movable contact 122 at the end of the primary plunger 310. When the movable contact 122 contacts the fixed contact 120, the retention spring 324 can be compressed. The retention spring 324 can hold the movable contact 122 in contact with the fixed contact 120. In an exemplary embodiment, a second retainer clip 328 is coupled to the primary plunger 310 at the second end 314. The second retainer clip 328 is used to couple the primary plunger 310 to the primary armature 306. The second retainer clip 328 contacts a bottom surface of the primary armature 306 and holds the primary plunger 310 in a central hole of the primary armature 306. A primary return spring 320 holds a bottom surface of the primary armature 306 against a second retainer clip 328. The primary plunger 310 is movable with the primary armature 306 upon activation and deactivation of the first electromagnet 304.

[0020] In an exemplary embodiment, the second end 312 of the primary plunger 310 is coupled to a secondary plunger of the secondary coil assembly 206. For example, the primary plunger 310 includes a mounting foot 330 at the second end 312. The mounting foot 330 is received by the secondary plunger. The mounting foot 330 includes a shaft 332 and a flange 334 at an end of the shaft 332. The shaft 332 is slidable within the secondary plunger. The flange 334 abuts against the secondary plunger and controls the amount of lift movement of the primary plunger 310 relative to the secondary plunger. The mounting foot 330 can move a sufficient distance relative to the secondary plunger to abut the movable contact 122 against the fixed contact 120 and disengage the movable contact 122 from the fixed contact 120 to close or open the main circuit upon activation and deactivation of the first electromagnet.

[0021] The primary coil assembly 204 is disposed above the wall 208 and the secondary coil assembly 206 is disposed below the wall 208. The secondary coil assembly 206 includes a secondary winding or coil 400 wrapped around a secondary core 402 to form a second electromagnet 404. The secondary coil assembly 206 includes a secondary armature 406 received in a secondary sleeve 408. The secondary coil assembly 206 includes a secondary plunger 410 coupled to the secondary armature 406. A secondary return spring 420 surrounds the secondary plunger 410. In the exemplary embodiment, the secondary coil assembly 206 includes a permanent magnet 450 at a bottom of the secondary coil assembly 206.

[0022] In the exemplary embodiment, the permanent magnet 450 normally holds the secondary armature 406, and therefore the secondary plunger 410, in a raised or upward position. In operation, when the secondary coil 400 is energized to create a magnetic field, the secondary armature 406 moves in a downward actuation direction, causing the secondary plunger 410 to move downward away from the stationary contact 120. The electromagnetic field can overcome the action of the permanent magnet 450, causing the secondary armature 406 and the secondary plunger 410 to move downward. The secondary return spring 420 moves the secondary armature 406 downward. The secondary plunger 410 can butt up against the permanent magnet 450. When the second electromagnet 404 is deactivated, the permanent magnet 450 again causes the secondary armature 406, and therefore the secondary plunger 410, to move upward. By moving the secondary plunger 410, the position of the primary plunger 310 is changed, for example, the abutment distance between the movable contact 122 and the fixed contact 120 is changed.

[0023] The secondary plunger 410 extends between a first end 412 and a second end 414. In the illustrated embodiment, the first end 412 is the top of the secondary plunger 410 and the second end 414 is the bottom of the secondary plunger 410. However, in alternative embodiments, other orientations are possible. The primary plunger 310 is coupled to the secondary plunger 410 at the first end 412. For example, the mounting foot 330 of the secondary plunger 410 is coupled to the first end 412 of the secondary plunger 410. In the exemplary embodiment, the secondary plunger 410 extends through a central opening in the wall 208 such that the first end 412 is disposed above the wall 208 to connect to the primary plunger 310.

[0024] In the exemplary embodiment, a secondary retainer clip 422 is coupled to the secondary plunger 410 at the second end 414. The secondary retainer clip 422 is used to couple the secondary plunger 410 to the secondary armature 406. The secondary retainer clip 422 contacts a bottom surface of the secondary armature 406 to hold the secondary plunger 410 in a central hole of the secondary armature 406. A secondary return spring 420 holds the bottom surface of the secondary armature 406 against the secondary retainer clip 422. The secondary plunger 410 is movable with the secondary armature 406 based on activation and deactivation of the second electromagnet 404.

[0025] In an exemplary embodiment, the first end 412 of the secondary plunger 410 includes a pocket 430 that receives the mounting foot 330 of the primary plunger 310. The secondary plunger 410 includes a shoulder 432 that extends into the pocket 430, such as at the top of the pocket 430. The shoulder 432 may be formed by a retainer clip coupled to the secondary plunger 410. The shoulder 432 is used to hold or capture the flange 334 of the mounting foot 330 in the pocket 430. The mounting foot 330 is movable within the pocket 430. For example, the mounting foot 330 may be vertically slidable within the pocket 430. The pocket 430 is sized to allow actuation of the first electromagnet 304 independent of the actuation of the second electromagnet 404. For example, the first electromagnet 304 can be activated to open or close the movable contact 122 relative to the stationary contact 120 without activating the second electromagnet 404. In various embodiments, the second electromagnet 404 can be activated to move the secondary plunger 410 independent of the operation of the first electromagnet 304. The flange 334 is configured to abut the secondary plunger 310 during operation of the first electromagnet 304 to control the amount of lift movement of the primary plunger 310 relative to the secondary plunger 410. For example, the flange 334 can abut the shoulder 432 at the top of the actuation stroke and the bottom 434 of the pocket 430 at the bottom of the actuation stroke. The mounting foot 330 can move a sufficient distance relative to the secondary plunger 410 to abut the movable contact 122 against the fixed contact 120 and to disengage the movable contact 122 from the fixed contact 120 to close or open the main circuit upon activation and deactivation of the first electromagnet 304.

[0026] 4 is a close-up view of a portion of the contactor 100 according to an exemplary embodiment showing the first coil assembly 204 coupled to the second coil assembly 206. The mounting foot 330 of the primary plunger 310 at the second end 314 of the primary plunger 310 is received in a pocket 430 at the first end 412 of the secondary plunger 410. The mounting foot 330 is movable within the pocket 430. The flange 334 is shown spaced apart from a shoulder 432 on the top of the secondary plunger 410 and spaced apart from a bottom 434 of the pocket 430. In the illustrated position, the primary plunger 310 can be moved in either direction relative to the secondary plunger 410 and / or the secondary plunger 410 can be moved in either direction relative to the primary plunger 310. For example, either electromagnet 304, 404 can be activated or deactivated to move the corresponding plunger 310, 410.

[0027] 5 is an enlarged view of a portion of the contactor 100 according to an exemplary embodiment showing the first coil assembly 204 and the second coil assembly 206. FIG. 5 shows the primary magnetic circuit path of the primary coil assembly 204 and the secondary magnetic circuit path of the secondary coil assembly 206 upon activation of the electromagnets 304, 404. The primary magnetic circuit path flows through the walls of the housing 110, including the wall 208, the primary armature 306 and the primary sleeve 308. The secondary magnetic circuit path flows through the walls of the housing 110, including the wall 208, the secondary armature 406, the secondary sleeve 408, and the permanent magnet 450. In the illustrated embodiment, the primary magnetic circuit path flows in a clockwise direction and the secondary magnetic circuit path flows in a counterclockwise direction. In alternative embodiments, other flow path directions are possible.

[0028] A tertiary magnetic leakage path, shown by the dotted path, may occur and may flow in the same or opposite direction as either the primary or secondary magnetic circuit paths. In an exemplary embodiment, the spring force of the return springs 320, 420 is sufficient to overcome the effects of the tertiary magnetic leakage path. In various embodiments, the detrimental effects of the tertiary magnetic leakage path can be mitigated by adding a second intermediate core or air gap, if desired.

[0029] Returning to FIG. 3 and with reference to FIGS. 6-8, various modes of operation are illustrated. FIGS. 6-8 are cross-sectional views of the contactor 100 showing the primary coil assembly 204 and the secondary coil assembly 206 in various states. FIG. 3 shows the contactor 100 in a first mode, showing the primary coil assembly 204 activated and the secondary coil assembly 206 deactivated. FIG. 6 shows the contactor 100 in a second mode, showing the primary coil assembly 204 deactivated and the secondary coil assembly 206 deactivated. FIG. 7 shows the contactor 100 in a third mode, showing the primary coil assembly 204 deactivated and the secondary coil assembly 206 activated. FIG. 8 illustrates the contactor 100 in a fourth mode, with the primary coil assembly 204 activated and the secondary coil assembly 206 activated. In an exemplary embodiment, the primary coil assembly 204 is operable to move the movable contact 122. The secondary coil assembly 206 is operable independently of the primary coil assembly 204 to vary the length of the abutment gap 230 between the movable contact 122 and the stationary contact 120. FIGS. 3 and 6-8 illustrate various combinations of activation / deactivation of the primary coil assembly 204 and secondary coil assembly 206, showing the abutment contact 112 abutting and disabutting by operating the primary coil assembly 204, and showing short and extended abutment gaps by operating the secondary coil assembly 206.

[0030] In operation, when the primary electromagnet 304 is activated (FIGS. 3 and 8), the primary coil 300 is energized to create a magnetic field. The primary armature 306 advances in an upward actuation direction, such as to move the primary plunger 310, and thus the movable contact 122, in a forward direction. Upon activation, the movable contact 122 abuts the fixed contact 120 to close the main circuit and allow the transmission of power through the fixed contact 120 and the movable contact 122. When the primary electromagnet 304 is deactivated (FIGS. 6 and 7), the primary coil 300 is deenergized to remove the magnetic field, and the primary return spring 320 can return the primary armature 306, and thus the primary plunger 310 and the movable contact 122, in a return direction (e.g., downward). Upon deactivation, the movable contact 122 disengages from the fixed contact 120 to open the main circuit.

[0031] In operation, when the secondary electromagnet 404 is activated (FIGS. 7 and 8), the secondary coil 400 is energized to create a magnetic field. The secondary armature 406 moves in a downward actuation direction to move the secondary plunger 410 downward, away from the stationary contact 120. The electromagnetic field overcomes the action of the permanent magnet 450 to move the secondary armature 406 and the secondary plunger 410 downward. The secondary return spring 420 moves the secondary armature 406 downward. The secondary plunger 410 abuts against the permanent magnet 450. When the secondary electromagnet 404 is deactivated (FIGS. 3 and 6), the secondary coil 400 is deenergized to remove the magnetic field, and the permanent magnet 450 can move the secondary armature 406, and therefore the secondary plunger 410, upward.

[0032] The secondary coil assembly 206 operates to move the primary coil assembly 204 relative to the stationary contact 120. The secondary plunger 410 controls the vertical travel limit of the primary plunger 310 relative to the secondary plunger 410 to control the stroke or abutment distance of the primary plunger 310 during operation of the primary coil assembly 204. For example, the secondary coil assembly 206 operates to move a stop position of the primary plunger 310 relative to the stationary contact 120 to vary the stroke length or abutment distance required to bring the movable contact 122 into close proximity with the stationary contact 120. The secondary plunger 410 controls the position of the primary plunger 310 relative to the stationary contact 120. For example, moving the secondary plunger 410 changes the position of the primary plunger 310, e.g., changes the abutment distance between the movable contact 122 and the fixed contact 120. In an exemplary embodiment, upon deactivation of the secondary electromagnet 404, the actuator 202 can operate in a short gap mode (FIGS. 3 and 6), and upon activation of the secondary electromagnet 404, the actuator 202 can operate in an extended gap mode (FIGS. 7 and 8). The abutment gap 230 between the movable contact 122 and the fixed contact 120 has a first length 232 (FIG. 6) in the short gap mode, and the abutment gap 230 has a second length 234 (FIG. 7) in the extended gap mode. The first length 232 is shorter than the second length 234.

[0033] During assembly, a mounting foot 330 at the bottom of the primary plunger 310 is received in a pocket 430 at the top of the secondary plunger 410. The mounting foot 330 is vertically slidable within the pocket 430. For example, the flange 334 is movable between a shoulder 432 at the top of the pocket 430 and a bottom 434 of the pocket 430. The shoulder 432 defines an upper limit of travel for the flange 334, and the bottom 434 defines a lower limit of travel for the flange 334. Changing the position of the secondary plunger 410 relative to the fixed contact 120 changes the positions of the top and bottom stops of the primary plunger 310. For example, activating and deactivating the second electromagnet 404 to change the vertical position of the secondary plunger 410 can change the start and end positions of the primary plunger 310, e.g., change the stroke or abutment distance.

[0034] The first electromagnet 304 and the second electromagnet 404 are independently operable for different modes of operation. For example, the actuator 202 can be operated in a first mode for normal operation, in a second mode for safety operation such as when transmitting high current, and in a third mode for repair operation such as to break a weld when the movable contact 122 sticks to the fixed contact 120. The actuator 202 varies the abutment gap 230 between the movable contact 122 and the fixed contact 120 between the various modes, e.g., increasing or decreasing the abutment gap 230 to vary the switching time for closing the movable contact 122 or to enhance circuit interruption performance.

[0035] The first mode is used for normal operation. The first mode is a short gap mode in which the abutment gap 230 is relatively short (e.g., compared to the extended gap mode). In an exemplary embodiment, in the short gap mode, the secondary coil assembly 206 is in an advanced or forward position (FIGS. 3 and 6). For example, the second electromagnet 404 is deactivated. The repulsive force of the permanent magnet 450 moves the secondary armature 406 and the secondary plunger 410 to an advanced position (e.g., closer to the stationary contact 120). In the advanced position, the backstop of the primary plunger 310 (e.g., the bottom 434 of the pocket 430) is positioned forward compared to the rearward or retracted position shown in FIGS. 7 and 8. Thus, the primary plunger 310 is positioned forward and the abutment gap 230 is shortened, allowing for rapid opening and closing (e.g., rapid movement between the positions shown in Figures 3 and 6). When the primary coil 300 is energized, the movable contact 120 can be moved quickly from the open position (Figure 6) to the closed position (Figure 3). In the short gap mode, the contactor 100 is a fast acting contactor.

[0036] The second mode is used for safety operation, e.g., interrupting high current. The second mode is an extended gap mode when the abutment gap 230 is relatively long (e.g., compared to the short gap mode). In an exemplary embodiment, in the extended gap mode, the secondary coil assembly 206 is in a retracted or rearward position (FIGS. 7 and 8). For example, the second electromagnet 404 is activated to overcome the repulsive magnetic force of the permanent magnet 450 and drive the secondary armature 406 and the secondary plunger 410 downward. The second end 414 of the secondary plunger 410 can abut against the permanent magnet 450 in the retracted position. In the retracted position, the backstop of the primary plunger 310 (e.g., the bottom 434 of the pocket 430) is positioned rearward compared to the forward or forward position shown in FIG. 3 and FIG. 6. Thus, the primary plunger 310 is positioned rearward and the abutment gap 230 is extended to provide a higher current interruption and reduce the risk of electrical arcing. The primary plunger 310 has a longer stroke or travel distance to move from the open position (FIG. 7) to the closed position (FIG. 8).

[0037] In an exemplary embodiment, the secondary plunger 410 defines a magnetically latched stop for the primary plunger 310. For example, a permanent magnet 450 below the secondary plunger 410 is used to magnetically actuate the secondary plunger 410 and hold it in an advanced position until, for example, the second electromagnet 404 is activated. In an exemplary embodiment, the permanent magnet 450 forms a latching stop for the secondary plunger 410. For example, upon operation of the secondary coil assembly 206, the secondary plunger 410 contacts the permanent magnet 450.

[0038] The secondary plunger 410 interfaces with the primary plunger 310 to control or limit the movement of the primary plunger 310. The primary plunger 310 has a limited amount of float movement between an upper vertical limit (e.g., flange 334 contacts shoulder 432) and a lower vertical limit (e.g., flange 334 contacts bottom 434). When the secondary plunger 410 is actuated beyond the lower vertical limit, the secondary plunger 410 moves the primary plunger 310 away from the fixed contact 120.

[0039] The third mode is used for repair operations such as to break the weld when the movable contact 122 sticks to the fixed contact 120. For example, in some circumstances, the movable contact 122 may become welded to the fixed contact 120 due to high current operation and / or arcing. The secondary plunger 410 may be pulsed and / or adjusted to repeatedly advance and retract the secondary plunger 410 to break the weld and release the movable contact 122. For example, the secondary plunger 410 is used to strike the primary plunger 310 to break the weld. The shoulder 432 strikes the flange 334 and induces a downward force on the primary plunger 310, which is transferred to the movable contact 122 to break the weld. In an exemplary embodiment, the first electromagnet 304 is deactivated in the third mode. The second electromagnet 404 is activated and deactivated in the third mode (e.g., pulsed between an advanced position (FIG. 6) and a retracted position (FIG. 7)). When the movable contact 122 is released, the contactor 100 can be operated in either the first mode or the second mode.

[0040] In an exemplary embodiment, the actuator 202 includes a current sensor 250 that senses the current of the main circuit through the stationary contact 120 and the movable contact 122. The secondary coil assembly 206 is operatively coupled to the current sensor 250 to activate the secondary coil assembly 206, such as when the current sensed by the current sensor is higher than a threshold current. The current sensor 250 is used to change operation from a first mode (e.g., short gap mode) to a second mode (e.g., extended gap mode). For example, the current sensor 250 determines when the main circuit is carrying a high current and changes the actuator 202 to operate in the extended gap mode to interrupt the high current. In various other embodiments, the current sensor 250 is used to determine when a welded condition occurs between the movable contact 122 and the stationary contact 120. For example, if the first electromagnet 304 is deactivated but the movable contact 122 is still coupled to the fixed contact 120, the actuator 202 can operate in a third mode to break the weld.

Claims

1. A contactor (100), a housing (110) having a cavity (112); a fixed contact (120) received in the cavity, the fixed contact having an end (132) that abuts against the cavity; a movable contact (122) movable within the cavity to abut and disengage from the fixed contact, the movable contact electrically connecting the fixed contact in an abutting position, and an abutment gap (230) being formed between the movable contact and the fixed contact when the movable contact disengages from the fixed contact; an actuator (202) operatively coupled to the movable contact to move the movable contact relative to the fixed contact within the cavity, the actuator including a primary coil assembly (204) and a secondary coil assembly (206), the primary coil assembly operable to move the movable contact and the secondary coil assembly operable independently of the primary coil assembly to vary a length of the abutment gap; A contactor (100) comprising:

2. 2. The contactor of claim 1, wherein the actuator is operable in a short gap mode and an extended gap mode, the abutment gap having a first length in the short gap mode and the abutment gap having a second length in the extended gap mode, the first length being less than the second length.

3. The contactor (100) of claim 1, wherein the secondary coil assembly (206) is operative to move the primary coil assembly (204) relative to the stationary contact (120).

4. 2. The contactor of claim 1, wherein the primary coil assembly includes a primary plunger coupled to the movable contact, and the secondary coil assembly includes a secondary plunger coupled to the primary plunger, the secondary plunger controlling a position of the primary plunger relative to the stationary contact.

5. 2. The contactor of claim 1, wherein the primary coil assembly includes a primary plunger and the secondary coil assembly includes a secondary plunger extending between a first end and a second end, the first end coupled to the movable contact and the second end slidably coupled to the secondary plunger.

6. 6. The contactor of claim 5, wherein the secondary plunger controls a vertical travel limit of the primary plunger relative to the secondary plunger to control a stroke of the primary plunger during operation of the primary coil assembly.

7. 6. The contactor of claim 5, wherein the secondary plunger includes a pocket at an end of the secondary plunger and a shoulder extending into the pocket, the primary plunger includes a mounting foot at the second end of the primary plunger, the mounting foot received in the pocket and slidable within the pocket to permit movement of the primary plunger relative to the secondary plunger, the mounting foot having a flange configured to contact the shoulder to stop movement of the primary plunger relative to the secondary plunger.

8. The contactor (100) of claim 5, wherein the secondary plunger (410) defines a magnetically latched stop for the primary plunger.

9. 6. The contactor of claim 5, wherein the secondary coil assembly includes a permanent magnet below the secondary plunger, the permanent magnet forming a latching stop for the secondary plunger, and wherein the secondary plunger contacts the permanent magnet upon operation of the secondary coil assembly.

10. 6. The contactor of claim 5, wherein the secondary plunger (410) is coupled to the primary plunger (310), the primary plunger having a limited amount of float travel between an upper vertical limit and a lower vertical limit between the primary plunger and the secondary plunger, and when the secondary plunger is actuated beyond the lower vertical limit, the secondary plunger moves the primary plunger away from the stationary contact (120).

11. 2. The contactor (100) of claim 1, wherein the actuator includes a current sensor that senses current in a main circuit through the fixed contact and the movable contact, and the secondary coil assembly is operatively coupled to the current sensor to activate the secondary coil assembly when the current sensed by the current sensor is higher than a threshold current.

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