FR2902232A1 - Electrical component e.g. defective battery element, by-pass device for spacecraft, has switch with line providing continuity between studs, and shaft including prong with thread and retained by release made of phase change material - Google Patents

Abstract

The device has a case (2) with conductor terminals each including an end connected to a terminal of a battery element and another end constituting contact studs (P1-P3). An actuator (9) moves a monoblock plunger shaft (12) between two positions and has a spring (21) arranged in a space (D2) between the shaft and an inner wall of the case. A release (10) made of phase change material retains the shaft, and a switch (11) has a conductive line providing electrical continuity between the studs. The shaft has a shoulder (17) and a prong (16) with a thread (18) at an outer surface of the prong.

Description

Switch for a bypass device of an electrical component 10

  The present invention relates to a device for bypassing an electrical component and more particularly to a bypass device that is thermally activated by means of a control current. It is more particularly applicable in the isolation and short-circuiting of a battery element that has become defective.

  Protection against this type of incident has been the subject of numerous studies, in particular for batteries that are difficult to access such as those embedded in spacecraft. Indeed, when a battery cell becomes defective it is imperative to isolate it so that it does not damage the operation of the healthy elements of the battery which can then continue their action and continue to provide a voltage to the circuit that the battery is 25 in charge of powering.

  Bypass devices also known as battery by-pass generally consist of an actuator, a trigger and a switch housed in a housing. Each of these three components has its own function. Thus the actuator is a mechanical member which must ensure the translation between two positions of a control member called shaft or plunger. The trigger is a member made of a fusible material which, when subjected to an electrical control current thus producing a rise in temperature, melts or breaks in order to release the actuator. The switch is a member ensuring, in each of its two positions, the electrical continuity between two of the three terminals carried by the housing and connected to the terminals of the circuit of the battery element.

  At one of its ends the shaft generally comprises a flange which serves as a stop for a spring disposed in the space defined between the shaft and the inner wall of the housing. This space has a circular shoulder formed on the inner surface of the housing so as to trap the spring between the flange of the shaft and the circular shoulder. The spring is thus kept in compression as long as the shaft is held in the armed position by the release, that is to say when the shaft holds the switch in the normal operating position and the electrical continuity is ensured between two first terminals. In case of malfunction of a battery element, the trigger is then actuated and releases the shaft. This is then moved in translation from its armed position to the released position under the pressure of the spring. This position released by the release allows the shaft to bring the switch into the isolation position of the faulty battery element by providing electrical continuity between a first and a second terminal. Triggers using a fuse material that background or breaks on raising the temperature of the material by passing an electric current are well known.

  This principle is described in U.S. Patent 3,388,933 which relates to a fuse-linkable trigger now holding separable half-shells for holding and releasing strapping of bulky objects.

  An application of this principle is particularly disclosed in US Pat. No. 3,924,688 which describes the release of an actuator shaft held by two locked half-shells in contact via a coil of stressed wire whose expansion is controlled by the fusion of a link. The relaxation of the coil allows the separation of the two half-shells and thus the release of the shaft.

  An improvement to this principle is disclosed by US Patent 5,471,888 which describes an embodiment comprising two half-shells 20 and an insulator on which is placed the fuse link.

  The actuator technology for isolating a battery cell as soon as it exhibits an abnormality by physically separating two parts of an assembly through the melting of a link responsive to an electrical threshold is also well known. US Patent 5,362,576 relates to a conductive plunger located between two terminals constituting the ends of an insulating cylinder. An output terminal is connected to the battery element. In normal operation the plunger is kept in electrical contact with the terminal via a fuse link. The current then flows between the terminals by the plunger which further comprises peripheral contacts in the form of metal sleeves. When exceeding an electrical threshold corresponding to an increase in the internal resistance of the battery element, the thermal bond weakens, melts and breaks. The plunger is then propelled by the release of stress of the spring is after breaking the electrical continuity between the first terminals, ensures a derivation of the current by connecting the first and second terminals.

  US Patent 5,438,173 relates to a battery bypass device comprising a mobile unit composed of a base, a compression spring, an element having erasable arms which hold a plunger. The plunger is equipped with release means intervening during a failure, by deleting the arms, thus releasing the moving equipment and making it possible to establish an electrical circuit for bypassing.

  US Pat. No. 6,249,063 discloses a conductive half-shaft carrying toroidal contacts, mechanically connected to an insulating half-shaft, providing electrical continuity between terminals, the plunger, mechanically connected to the insulating half-shaft, is held by two half-shells, which are maintained even in contact via a coil of wire under stress, this stress being released when a fuse link is destroyed on an electrical threshold. All the embodiments described in the prior art implement a relatively high number of parts that may separate during their use in harsh environments, which are expensive during assembly operations and which can not be used indifferently in all the models requested by the customers. In addition, this high number of parts does not allow for easy installation, maintenance, or easy repair of on-site devices.

  There is therefore a need to define a modular device for bypassing electrical component with great flexibility of use for the adaptation, assembly and replacement of the various components.

  Such a device must be modular and must also provide absolute safety to avoid, during assembly and assembly in workshops, any risk of inadvertent tripping. Finally, in case of inadvertent tripping, this device must allow a repositioning of the components without complete disassembly.

  The object of the present invention is to allow the adaptation, mounting, fixing and easy replacement of the different types of switches on the end concerned of the diving shafts.

  This is why the present invention relates to a modular device for bypassing an electrical component comprising a housing having removable closure means and equipped with conductive terminals, one end of which is connected to one of the terminals of the circuit of the electrical component, the other end is fixed on the wall of the housing, opens into the housing and constitutes a contact pad; an actuator ensuring the translation, between two positions, of a control member consisting of a plunger shaft and comprising a spring disposed in the space defined between the plunger shaft and the inner wall of the housing; a trigger comprising a retention device of the plunger shaft held by a fusible material; a switch comprising a contact zone providing electrical continuity between two contact pads of the terminals carried by the housing, branching device in which the actuator plunger shaft is a one-piece shaft.

  According to the invention, the plunger shaft comprises, at one of its ends, a cylindrical portion in the form of a pin.

  According to the invention the spindle is provided with a threaded portion.

  According to a preferred embodiment of the invention, the plunger shaft is made of conductive material; and according to one variant, the plunger shaft is made of insulating material.

  According to a preferred embodiment, the switch is equipped with a jacket which, when it is conducting, provides electrical continuity between the pads according to the position of the plunger shaft.

  According to this mode, an insulating spacer and shim ensure the positioning and locking of the conductive jacket.

  According to a first embodiment, the contact pads are equipped with circular metal strip contacts projecting into the space of the housing.

  According to a second embodiment, the conductive jacket has recesses for positioning circular metal strip contacts protruding into the housing space. According to a third embodiment, the liner is in the form of a key receiving housing made of conductive material ensuring electrical continuity between the pads according to the position of the plunger shaft.

  In this mode, the keys are held in place by means of a rod and held in compression by means of springs positioned in the housing and acting on the keys. Alternatively, the spring is individual, reported or integrated.

  The invention will be better understood with the aid of the following description and the appended drawings in which,

  FIG. 1 represents a sectional view of an embodiment of the branching device according to the invention.

  Figures 2a and 2b show a sectional view of a trigger element according to a first embodiment

  Figures 3a and 3b show a sectional view of a trigger element according to a second embodiment;

  Figure 4 shows a sectional view of a trigger element according to a third embodiment; Figure 5 shows a sectional view of a switch element according to a first embodiment;

  Fig. 6 is a sectional view of a switch element according to a second embodiment; Figures 7a, 7b show a sectional view of a switch element according to a third embodiment.

  The bypass or bypass device 1 comprises a cylindrical casing 2 made of insulating material provided at its ends with removable closure means 3, 4 fixed to the cylindrical wall by means of studs 5. Terminals Ti, T3 pass through the 2. It will be noted that T2 is not shown in FIG. 1. These terminals, providing the power supply for T1 and T2 and the derivation function for the terminals T2 and T3, are connected by their end to the terminal. outside the housing at the terminals of the circuit of the battery element not shown. The annular end of each terminal T1, T2, T3 located inside the housing 2 defines a contact pad P1, P2, P3 whose role will be described below.

  The housing 2 has on its inner surface 6 two shoulders 7 and 8 which correspond to the change in diameter between the inner sections D1, D2 of the housing 2.

  The housing 2 is provided to receive the three elements constituting the bypass, namely an actuator 9, a trigger 10, a switch 11 which make it possible to isolate, using a control current, a battery element that has become defective thus ensuring the proper functioning of the remaining cells of the battery.

  Each of these three elements has its own function.

  The actuator 9 is a mechanical member which must ensure the translation, between two positions, of a control member called a plunger shaft 12. The trigger 10 is a member made of a fusible material which, when subjected to a electrical control current producing a rise in temperature, bottom or breaks to release the actuator 9. The switch 11 is a member ensuring, in each of its two positions, the electrical continuity between two of the three terminals Ti, T2, T3 connected to the terminals of the circuit of the battery element.

  According to the embodiment shown in Figure 1, the bypass comprises the housing 2 of insulating material within which is positioned and guided the displaceable shaft 12, movable in translation, electrically conductive material It is it is obvious that according to the design of the model requested by the customer, the diving shaft can be made of insulating material. In both cases the plunger shaft 12 is a one-piece shaft.

  The plunger shaft 12 has, at its end adjacent to the portion of the housing receiving the actuator 10, a barrel-shaped cylindrical portion 13 provided with a central bore defining a housing 14. The open end of the housing 14 is provided. a collar defining a flange 15 facing outwardly of the housing. The plunger shaft 12 comprises, at the end contiguous to the portion of the housing receiving the switch 11, a spindle-shaped cylindrical portion 16. The plunger shaft has at its middle part a shoulder 17 defined by the difference of the respective diameters. cylindrical portions of the spindle 16 and the barrel 13, this shoulder constituting a limit stop for the positioning and locking means of the parts of the switch 11. The spindle 16 is provided on its outer surface with a thread 18 allowing easy change and fixing of switch parts.

  The open end of the housing 14 allows the easy change and fixing of the parts equipping the trigger 10 with its central bore. These parts generally consist of an adapter 20 such as a plug of insulating or non-insulating material which bears on the flange 15 of the housing and which frictionally ensures the maintenance of the parts of the release inside the housing. Alternatively the housing has a thread 19 for changing and fixing parts with a bolt which ensures the complete screwing of the adapter in the thread 19.

  So as to ensure the translation of the plunger shaft 12 between an armed position, that is to say when the plunger shaft is held by the trigger 10 in normal operation and that the pads Pl and P2 are connected, a spring 21 is arranged coaxially on the outer surface of the cylindrical portion of the barrel 13. This spring 21 is held in compression in the space D2, defined between the outer surface of the shaft and the inner wall 6 of the housing, between the flange 15 of the shaft of the plunger shaft and the circular shoulder 8 formed on the inner surface of the housing. When activating the trigger 10, that is to say on abnormal operation of a battery element, the expansion of the spring 21 displaces the displacement shaft in translation in the space D1 where are positioned the parts of the trigger and the pads P2 and P3 are then connected.

  FIGS. 2a and 2b show a first embodiment of the release 10 in which a bolt is screwed into the thread 19 of the housing 14. This bolt comprises a collar which acts as a flange 15 and is provided in its central axis with a thread 22 receiving in support a screw 23 thereby generating a torque. The bolt is locked in rotation in a groove formed on the inner wall of the housing in which it slides.

  The screw 23 has a cylindrical portion 24 in which grooves 25 are machined and have a cam profile, visible in Figure 2b, in which abutting lugs 26 holding the screw 23 locked in rotation.

  The catches 26 are mounted in a coil 27 and are held in the locking position by a retaining wire 28 hooked on one side on the coil and on the other side with the fusible wire or link 29.

  When an electric current on exceeding a threshold feeds the fuse link 29, it fuses, releases the retaining wire 28 which unwinds and allows the spacing of the cleats 26 by lateral sliding due to the torque generated by the screw 23 and the thread 22 of the bolt and the cam profile of the bearing surface 25 with the end of the cleats 26.

  According to this example, the cleats 26 are two in number and are mounted in opposition. However, according to the sizing of the application, the use of a single cleat or several cleats is possible.

  Alternatively, the screw bolt connection may be located inside the cylindrical portion 24, the screw then being integral with the plunger shaft or an insulating part at the end of the shaft. It should also be noted that in the case of a shaft of conductive material it is necessary to isolate the trigger / shaft connection in order to prevent the potential of the switch terminals from interfering with the potential of the fuse wire of the trip unit.

  FIGS. 3a and 3b show a second embodiment of the release 10 in which the adapter 20 is fitted into the central bore of the housing 14. The adapter 20 made of insulating material comprises an insulating flange 30 that bears and covers the flange 15 and, in addition to the insulation, guiding the plunger shaft 12 during its movement in the space D 1. The adapter 20 comprises, opposite its fitted part, a stud 31 on which is fixed a metal pin 32 of ogival or conical shape. The metal pin is supported on cleats 26 in the number of three in this example as can be seen in Figure 3b. As in the previous embodiment the tabs 26 are guided in a coil 27 and are held in position by a retaining wire 28 hooked on one side on the coil and on the other side to the fuse link 29. According to this example, the cleats 26 are three in number and have risen in opposition. However, depending on the design of the application, the use of a single cleat or several cleats is possible in combination with a chamfered metal pin.

  When an electric current on exceeding a threshold feeds the fuse link 29, the latter fuses, releases the retaining wire 28 which unwinds and allows the spacing of the cleats 26 by lateral sliding between the cheeks of the coil through the shape of the support between the metal pin 32 and the chamfered inner portion of the tabs 26, the metal pin 32 then moving in the space D4 formed in the end piece of the trigger 10.

  FIG. 4 represents a variant of the embodiment shown in FIG. 3. The principle is identical except for the operating mode of the cleats 26. As in the previous embodiment, the metal pin bears on cleats 26, but contrary to the examples previous cleats 26 are not guided in the reel 27 when they are discarded. Indeed the tabs 26 have an arm 33 having an edge at its end, resting in the groove 34 formed in the end piece of the trigger 10. As in the previous example the tabs are held in position by a retaining wire 28 hooked on one side on the coil and the other side to a fusible link 29. Similarly, according to this example, the three cleats 26 are mounted in opposition. However, depending on the design of the application, the use of a single cleat or several cleats is possible in combination with a chamfered metal pin.

  When an electric current on exceeding a threshold feeds the fuse link 29, it melts, releases the retaining wire 28 which is unwound and allows the spacing of the latches 26 by pivoting, as indicated by the arrow F, thanks to in the form of the support between the metal pin 32 and the chamfered inner portion of the cleats 26. The metal pin 32 then moves in the space D4 formed in the end piece of the trigger 10.

  FIG. 5 represents a first embodiment of the switch 11. On the surface of the pads P1-P3 housed in recesses 35 formed on the inner surface 6 of the insulating material casing 2 are fixed circular metal contacts 36 in the form of those manufactured by Multi-Contact AG.

  These contacts are mounted projecting and open into the space D3 of the housing in which the pin 16 of the plunger shaft 12 moves in translation.

  The switch 11 is furthermore equipped with a liner 37 whose fixing is done by screwing onto the threaded portion 18 of the pin 16 of the plunger shaft 12. A spacer 38 for final positioning and locking of the liner is housed between the first end of the sleeve 37 and the chamfer 17 of the shaft. A shim 39 is located between the second end of the liner 37 and the removable closure piece 3 of the housing.

  When the jacket 37 is conductive, the spacer 38 and the wedge 39 are made of insulating material in order to complete the insulation of the conductive jacket 37 with respect to the neighboring stud P1 and to the shutter piece 3.

  It is obvious that the sleeve 37 can be fixed by any other operation than a screwing, using clips for example, insofar as this operation allows its subsequent replacement.

  In normal operation, that is to say when the plunger shaft is held in the armed position by the release, the supply circuit is effected by the connection of the sleeve 37 and the contacts 36 equipping the pads P1 and P2 thus ensuring the electrical continuity of the circuit. In the event of an incident on the battery element, the trigger 10 releases the plunger shaft 12 which, under the detent action of the spring 21, is driven in translation thus allowing the conductive jacket 37 to establish the connection between the contacts. 36 equipping the pads P2 and P3 thus ensuring the electrical continuity of the branch circuit.

  FIG. 6 shows a second embodiment in which two circular metal contacts 36 are each positioned in a recess 40 made on the outer surface of the conductive jacket 37. As in the previous example, the contacts are mounted projecting and open into the D3 space of the housing in which the pin 16 moves in translation. In normal operation, that is to say when the plunger shaft is retained in the armed position by the release, the supply circuit is effected by the connection of the sleeve 37 carrying the contacts 36 and the pads P1 and P2 . In the event of an incident on the battery element, the trigger 10 releases the plunger shaft 12 which, under the detent action of the spring 21, is driven in translation thus allowing the conductive jacket 37 to establish the connection between the contacts. 36 carried by the jacket and the pins P2 and P3 thus ensuring the bypass.

  According to an alternative embodiment, the width and the spacing of the pads P1, P2, P3 vis-à-vis the conductive jacket 37 are dimensioned to allow either an isolation or a short circuit of the three pads during switching.

  FIGS. 7a and 7b show a third embodiment in which the pin 16 receives on its threaded end portion 18 a jacket in the form of a housing 41 which is locked between the spacer 38 surrounding the pin 16 and the wedge 39, allowing the positioning of keys 42 of conductive material disposed concentrically in the housing 41 as shown in Figure 7b. The keys are held in place by means of a rod 43 and can be held in compression during operation by means of circular springs 44 positioned in the housing 41 and acting on the keys 42. As in the previous example the set of keys ensures electrical continuity by connecting pads P1, P2, P3 according to the position of the plunger shaft.

  According to a first variant of this third embodiment, the keys 42 are each held in compression by means of an individual spring reported and positioned in the housing 41.

  According to a second variant of this third embodiment, the keys 42 are made of beryllium bronze and are provided with an integrated spring arm holding each key thus equipped in compression with the aid of this individual spring being positioned during the assembly of the key in dwelling 41.

  The invention is not limited to the characteristics of the devices described. It encompasses, on the contrary, any device enabling the assembly, disassembly or replacement of elements constituting a modular device for shunting an electrical component.

Claims (11)

  1. Modular device for bypassing an electrical component comprising a housing (2) having removable closure means (3, 4) and equipped with conductive terminals (T1, T2, T3), one end of which is connected to one terminals of the circuit of the electrical component, the other end being fixed on the wall of the housing, opening inside the housing and constituting a contact pad (P1, P2, P3); an actuator (9) ensuring the translation, between two positions, of a control member consisting of a plunger shaft (12) and comprising a spring (21) disposed in the space (D2) defined between the plunger shaft ( 12) and the inner wall (6) of the housing; a trigger (10) comprising a retention device of the plunger shaft held by a fusible material; a switch (11) comprising a contact zone providing electrical continuity between two contact pads of the terminals carried by the housing, characterized in that the plunger shaft (12) of the actuator (9) is a one-piece shaft, provided with a shoulder (17), which has at one of its ends a pin-shaped cylindrical portion (16) for easy change and fixing of the switch (11).   2. modular branch device according to claim 1 characterized in that the switch (11) comprises a sleeve (37) held by screwing in the thread (18) of the pin (16).   3. Modular shunt device according to claims 1 and 2, characterized in that the jacket (37) is conductive and ensures electrical continuity between the contact pads (P1, P2, P3) according to the position of the plunger shaft ( 12).   4. Modular shunt device according to claims 1 to 3, characterized in that an spacer (38) and a shim (39) isolating ensure the positioning and locking of the conductive jacket (37).   5. Modular shunt device according to claim 1, characterized in that the pads (P1-P3) are equipped with metal contacts (36) circular strip protruding into the space (D3) of the housing (2).   6. modular branching device according to claims 1 to 3, characterized in that the conductive jacket (37) has recesses (40) for the positioning of circular metal contacts (36) strip protruding into the space (D3). of the housing (2).   7. Modular shunt device according to claim 1, characterized in that the liner (37) is in the form of a housing (41) for receiving keys (42) of conductive material.   8. modular branch device according to claim 7, characterized in that the keys (42) are held in place with a rod (43).   9. Modular shunt device according to claim 7, characterized in that the keys (42) are held in compression by means of springs (44) positioned in the housing (41) and acting on the keys (42).   10. modular branch device according to claim 7, characterized in that the keys (42) are each held in compression by means of individual springs reported positioned in the housing (41).   11. Modular shunt device according to claim 7, characterized in that the keys (42) are each held in compression by means of an integrated single spring positioned in the housing (41).