Title of Invention

"ELECTRICAL SWITCHGEAR DEVICE WITH ARC CHUTE WITH DEIONIZING FINS"

Abstract

The invention relates to an electrical switchgear device comprising a pair of separable electrical contacts (32, 33) arranged in an opening volume (35), an arc chute (10) opening out onto the opening volume (35) and being delineated by two side walls (11). The arc chute (10) comprises a stack of at least two deionizing fins (1) separated from one another by a exchange space (2), each fin (1) having a leading edge (5) designed to be exposed to the arc. The free leading edge (5) of at least two of the fins (1) delineates an open recess (9) of asymmetric shape and forming two lateral branches (1a, 1b), said recess being achieved in such a way as to create, when said fins (1) are stacked alternately, at least one chimney vent the duct whereof appears to be substantially closed (15) in a plane (xy) perpendicular to the longitudinal axis (16) of said chimney vent (15). Figure 2

Full Text

ELECTRICAL SWITCHGEAR DEVICE WITH ARC CHUTE WITH DEIONIZING FINS BACKGROUND OF THE INVENTION [1] The invention relates to an electrical switchgear device comprising a case having a longitudinal reference geometric plane, a pair of separable electrical contacts arranged in an opening volume, an arc chute opening out onto the opening volume and being delineated by two parallel side walls placed on each side of the reference geometric plane, a rear wall located away from the opening volume, a bottom wall and a top wall. The arc chute comprises a stack of at least two deionizing fins separated from one another by a exchange space, each fin having a leading edge designed to be exposed to the arc. At least one exchange space is connected to at least one removal duct via at least one removal hole. STATE OF THE ART [2] The presence of electrical faults inside switchgear devices such as electrical circuit breakers, switches or contactors causes high-speed opening of the electrical contacts thereof. This high-speed separation of the contacts is generally accompanied by the occurrence of an electric arc. The energy of the arc and the gas discharges accompanying the occurrence of said arc give rise to large stresses at the level of the mechanisms and are liable to damage the device. [3] To reduce the time the short-circuit is present and to thereby reduce the thermal stress withstood by the electrical switchgear device, the arcing voltage is increased as quickly as possible until it becomes greater than the applied voltage. This causes the short-circuit current to be cancelled out. The dielectric resistance of the air situated between the separated contacts then prevents reignition or other arc strikings. [4] The electric arc has to be cooled as quickly as possible while remaining away from the electrical contacts. This cooling is generally performed by placing the arc inside an arc chute comprising a stack of metal plates called deionizing fins. In practice, the electric arc, which has just arisen, is pushed into the arc chute by electrodynamic forces induced by a magnetic field due to the current flowing in the conductors. [5] When displacement of the arc takes place, the latter tends to move between the side walls of the arc chute generally taking the path of the recesses present in the fins. These recesses foster migration of the arc to the bottom of the arc chute. Furthermore, stacking of the fins causes the arc to be broken down and facilitates insertion thereof in the arc chute. The fins provide the arc with a exchange surface throughout breaking. At the moment the arc progresses into the arc chute, it tends to dilate to invade the whole available space. The fins contain this dilatation by interacting with the periphery of the arc. The arcing voltage increases as the arc cools. In addition, the pressure in the breaking volume increases greatly. [6] If the shape of the recesses is not optimized, repetitive arc re- strikings may occur between the contacts. [7] Certain documents (FR 2,839,195) divulge recesses terminated by a chimney vent which tends to stabilize the arc in a region located away from the opening volume of the contacts. However, the shape of the recess characterized by the presence of a corridor running from the zone in which the arc arises to the chimney vent can result in hot gases and vapours being sent in the direction of the opening zone of the contacts and thus cause leakage of the arc from the arc chute to the contacts. This leakage is accompanied by repetitive re-strikings. Moreover, the occurrence of the arc at the same time causes the occurrence of a large quantity of metallic vapours or gases, which may, if they are not removed, be responsible in particular for a linking arc between the phases of the electrical switchgear device and create an explosion. [9] Numerous existing solutions provide at least one duct for removal of said gases to the outside of the zone close to the contacts. These gases are generally expelled to the outside of the electrical switchgear device. [10] These solutions, although they provide advantages, may however generate nuisances in the premises where the switchgear devices are placed. Indeed, as these gases are still hot and highly ionized, they may give rise to harmful effects. [11] To prevent this pollution of the external environment, other solutions propose internal gas recycling (GB 2,285,889, US 5,731,561, FR 1,400,079). [12] These solutions may present certain drawbacks. This internal gas recycling is generally accompanied by an increase of the volume of the electrical switchgear device. Indeed, the gases are generally conducted into specific volumes located beyond the arc chute. In addition, the ducts used for conducting the gases may, on account of their geometry, induce pressure traps responsible for poor removal or slowing-down of said gases. SUMMARY OF THE INVENTION [13] The object of the invention is to remedy the shortcomings of the state of the art so as to propose an electrical switchgear device comprising deionizing fins enabling high-speed cooling of the electric arc. [14] The free leading edge of at least two of the fins of the device according to the invention delineates an open recess of asymmetric shape and forming two lateral branches, said recess being achieved in such a way as to create, when said fins are stacked alternately, at least one chimney vent the duct whereof appears to be substantially closed in a plane perpendicular to the longitudinal axis of said chimney vent. [15] Advantageously, the device comprises, along the z-axis, at least two alignment zones between a lateral branch of a first fin and at least one lateral branch of a second fin having undergone a 180° rotation around its longitudinal axis with respect to said first fin. [16] In a preferred embodiment of the invention, the free leading edge of the fins is in contact at least twice with the longitudinal axis of said fins. [17] In a preferred embodiment of the invention, the free leading edge of the fins cuts the longitudinal axis of said fins at least twice. Advantageously, the switchgear device comprises, along the z-axis, at least one overlap zone between a lateral branch of a first fin and at least one second fin having undergone a 180° rotation around its longitudinal axis with respect to said first fin. [19] Preferably, the free leading edge of the recess delineates a first tapered front portion opening out onto the opening volume and a second longitudinal rear portion extending towards the rear wall, the first tapered front portion being cut by the longitudinal axis of the fins. [20] According to one embodiment of the invention, each fin is positioned next to another fin having undergone a 180° rotation with respect to its longitudinal axis. [21] According to a particular embodiment of the invention, at least one removal duct extends from at least one removal hole to an opening, along at least one side wall, said duct comprising a substantially constant or increasing cross- section along the z-axis from the inlet of the gases to their outlet from said duct, said opening being at least equal to the largest cross-section of said duct and being placed facing the electrical contacts of the opening volume. [22] Preferably, each exchange space of the arc chute comprises at least one removal hole connected to at least one removal duct. [23] Preferably, the device comprises at least two removal ducts, at least one duct extending along each side wall of the arc chute. [24] Advantageously, the exchange spaces of the arc chute comprise at least two removal holes, at least one hole being connected to each of the removal ducts extending along each wall. [25] Preferably, the removal holes are placed in a zone comprised between the rear wall and the median axis of the fins. [26] The removal holes are placed in the side walls. [27] The removal holes are placed in the rear wall. The removal ducts have a substantially parallelepipedic shape. BRIEF DESCRIPTION OF THE FIGURES [29] Other advantages and features will become more clearly apparent from the following description of a particular embodiment of the invention, given as a non-restrictive example only, and represented in the accompanying drawings in which: • figure 1 represents a side view of an electrical switchgear device according to a first preferred embodiment of the invention; • figure 2 represents a cross-sectional view along a plane II of an electrical switchgear device according to figure 1; • figure 3 represents a cross-sectional view along a plane JJ of an electrical switchgear device according to figure 2; • figure 4A represents a detailed view of a deionizing fin of an electrical switchgear device according to figure 1; • figure 4B represents a detailed view of a stack of deionizing fins according to figure 4A; • figures 5A, 5B respectively represent a detailed view of a fin and of a stack of deionizing fins of an electrical switchgear device according to a variant of the first preferred embodiment of the invention; • figure 6A represents a detailed view of a deionizing fin of an electrical switchgear device according to a second preferred embodiment; • figure 6B represents a detailed view of a stack of deionizing fins according to figure 6A; • figures 7A, 7B respectively represent a detailed view of a fin and of a stack of deionizing fins of an electrical switchgear device according to a variant of the second preferred embodiment of the invention; • figures 8A to 10B represent alternative embodiments of deionizing fins of the arc chute; • figure 11 represents an alternative embodiment of an electrical switchgear device according to figure 1. DETAILED DESCRIPTION OF AN EMBODIMENT [30] According to a first preferred embodiment presented in figures 1, 2 and 3, the electrical switchgear device 30 comprises a case 31 made of moulded plastic material in which there are arranged at least one stationary contact 32 associated with at least one movable contact 33. One or more fault detection devices, in particular for short-circuit detection, act on an actuating mechanism 34 commanding opening of the movable contact 33. [31] The case 31, on account of its shape, defines a longitudinal geometric reference plane xz. [32] In this embodiment presented, the electrical switchgear device comprises two U-shaped stationary contacts 32 respectively connected to an electrical connection terminal. The movable contact 33, able to move in translation by the action of the actuating device 34, enables the two stationary contacts 32 to be electrically connected. The movable contact 33 presents two contact zones 36 each respectively able to collaborate with a stationary contact 32. Two opening volumes 35 are thus defined corresponding to the space in which a stationary contact 32 and a contact zone 36 associated with the movable contact 33 are arranged. [33] In addition, each opening volume 35 is associated with an arc chute 10. The arc chute 10 opening onto the opening volume 35 is delineated by two parallel side walls 11 placed on each side of the longitudinal geometric reference plane xz, a rear wall 6 away from the opening volume 35, a bottom wall 7 and a top wall 8. [34] The arc chute 10 comprises a stack of at least two flat deionizing fins 1 perpendicular to the longitudinal geometric reference plane xz. Said fins are of substantially rectangular shape and comprise a longitudinal axis 12 and a median axis 13. Said fins comprise two main parts: a first front part 13a facing the opening volume 35 and extending from the front face of the arc chute 10 to the median axis 13, and a second rear part 13b extending from the median axis 13 to the rear wall 6. [35] Each fin 1 comprises a free leading edge 5 designed to be exposed to the arc. The free leading edge 5 preferably forms an open recess 9 extending in the direction of the longitudinal axis 12, from the front face of the arc chute 10 to the rear wall 6. This recess 9 delineates two lateral branches 1a, 1b. [36] The recess 9 of at least two fins 1 is of asymmetric shape and comprises two portions. It comprises a first tapered front portion 9a facing the contacts 32, 33 placed in the opening volume 35 and a second narrower longitudinal rear portion 9b. [37] According to a preferred embodiment of the invention, as represented in figures 6A and 7A, the leading edge 5 running along the flat surface of said at least two fins is in contact at least twice with the longitudinal axis 12 of the fins at the points a, b. In another preferred embodiment of the invention, as represented in figures 4A and 5A, the leading edge 5 cuts the longitudinal axis 12 of said at least two fins three times at the points a, b, c. According to these preferred embodiments of the invention, the recess 9 is achieved in such a way that when two fins are stacked alternately, at least two alignment zones a and b exist, along the z-axis, between a lateral branch 1a of a first fin 1 and at least one lateral branch 1a of a second fin 1 placed in an alternated position. A fin is in an alternated position with respect to another when it has undergone a 180° rotation around its longitudinal axis 12. The first alignment zone a is preferably situated in the front part 13a of the fin 1. [39] When the leading edge 5 cuts the longitudinal axis 12 three times, there exist three alignment zones a, b and c between a lateral branch 1a of a first fin 1 and at least one lateral branch 1a of a second fin 1 placed in an alternated position. There then exists an overlap zone 50 of the lateral branches 1a. Each fin comprises an overlap zone 50 delineated by the intersection, at the points a and b, between the longitudinal axis 12 and the leading edge 5 of the first lateral branch 1a. [40] According to these two preferred embodiments of the invention, the two lateral branches 1a, 1b are substantially placed on each side of said longitudinal axis 12 and the first tapered front portion 9a is cut by the longitudinal axis 12. [41] In the embodiments as represented in figures 1 to 11, all the fins placed in the arc chute 10 comprise the same recess 9. Stacking of the set of fins 1 of the arc chute 10 is performed in such a way that at least two of the fins are stacked alternately so that the shapes of their recess 9 do not coincide. [42] Advantageously, all the fins 1 are stacked alternately so that each fin 1 is positioned next to another fin having undergone a 180° rotation with respect to its longitudinal axis 12. [43] Due to the asymmetric shape of the recesses 9 of the fins 1 and to stacking of said fins in alternate manner, there is formed a chimney vent 15 the duct whereof appears to be substantially closed in a plane xy perpendicular to the longitudinal axis 16 of said chimney vent 15. [44] In the embodiment, the chimney vent 15 extends over the whole height of the arc chute, from the bottom wall 8 to the top wall 7. [45] Depending on the shape of the recesses 9 of the fins 1, the axis 16 of the chimney vent 15 will be more or less close to the rear wall 6 of the arc chute 10. The chimney vent 15 is preferably positioned at the level of the median axis 13 of the fin 1 or beyond said axis towards the rear wall 6. [46] The fins are made from a steel-based conducting material. The deionizing fins 1 stacked on one another are separated from one another by a exchange space 2. The thickness of each exchange space 2 is slightly greater than the thickness of the fins. [47] The gases or metallic vapours present in the arc chute 10 can be removed in traditional manner by means of at least one removal duct connected to one or more exchange spaces 2 via removal holes. The gases can be expelled to the outside of the electrical switchgear device with the risk of causing nuisances in the premises where the switchgear devices are placed. In a particular embodiment of the invention, gas recycling means are then used. At least one exchange space 2 is connected to at least one removal duct 3 via at least one removal hole 4. Said at least one removal duct 3 is designed on the one hand for removal of the gases from the arc chute 10 and on the other hand for injection of said gases, via an opening 18, at the level of the contacts 32, 33 of the opening volume 35. In addition, said at least one removal duct 3 extends from at least one removal hole 4 to the opening 18, along at least one side wall 11. Said opening 18 is placed facing the electrical contacts 32, 33 of the opening volume 35. [49] The gases then flow through an outflow duct composed of at least one removal hole 4, at least one removal duct 3 and at least one opening 18. Said removal ducts 3 have a constant or increasing cross-section A over their whole length and along the x-axis. In addition, said removal ducts 3 also preferably have a constant cross-section along the y-axis and the z-axis. In other words, the cross- section of said ducts is substantially constant from the inlet to the outlet of the gases. Advantageously the cross-section of said ducts can be increasing. The opening 18 is then at least equal to the largest cross-section A of said duct. [50] In a general manner, the cross-section of an outflow duct taken by the gases must at least remain constant or increase. This geometric particularity enhances the flow of the gases coming from the exchange spaces 2 and thus limits the creation of pressure traps that could form along the outflow duct. A decrease of the cross-section of said outflow duct, particularly at the level of the removal duct 3 or of the opening 18, could cause pressure traps to occur. These pressure traps could generate a slowing-down in the progression of the gases and in the progression of the electric arc. [51] Advantageously, in the preferred embodiment of the invention presented in figures 1 to 3, each exchange space 2 is connected to at least one removal duct 3 via at least one removal hole 4. The shape and size of the removal holes 4 are such that the gas flow does not cause the arc to pass via these holes. To avoid short-circuits between the fins 1, via the electric arc, the removal holes are achieved in independent manner and do not communicate with one another. [52] Preferably, at least two removal ducts 3 are present so that at least one duct 3 extends along each side wall 11 of the arc chute 10. In the embodiment presented in figures 1 and 2, each removal duct placed next to a side wall 11 extends from the removal holes 4 to an opening 18, from the bottom wall 8 to the top wall 7 and along the side wall 11. [53] In a preferred embodiment according to the invention as represented in figures 1 to 3, two removal ducts 3 are used. One removal duct 3 is placed next to each of the side walls 11 of the arc chute 10. Each exchange space 2 comprises at least un removal hole 4 connected to a removal duct 3. The removal holes 4, placed in the side walls 11, are positioned in a zone comprised between the rear wall 6 and the median axis 13 of the fins 1. In addition, the ducts are of substantially parallelepipedic shape. [54] The switchgear apparatus operates in the following manner. When a short-circuit occurs, the electromagnetic field induced by the current flowing in the conductors, and in particular in the stationary contact 32, generates electrodynamic forces in the movable contact 33 that repel the movable contact to the separated position, this movement being subsequently confirmed by opening of the actuating mechanism via the mechanism 34. As soon as separation of the contacts 32, 33 has taken place, an electric arc arises between said contacts. This arc is pushed into the arc chute 10 by the electrodynamic forces. During its displacement to the chimney vent 15 and the rear wall 6, the arc remains at mid- distance between the side walls 11, for it tends to pass via the open recesses 9 between the fins. [55] The fins 1 provide the arc with a exchange surface throughout breaking, in particular in their part near to the edges 5. In the course of its progression in the arc chute 10 or when it is installed in the chimney vent 15, the arc tends to dilate to invade the whole available space. The fins 1 contain this dilatation by interacting with the periphery of the arc. When the arc is situated in the chimney vent 15, the exchange is distributed uniformly around the arc and thus enables cooling of the latter to be optimized and extinction thereof to be accelerated. The arcing voltage increases as the arc cools which finally enables extinction of the arc when the electric current crosses zero. [56] The recesses 9 foster migration of the arc to the back of the arc chute 10, and the chimney vent 15 stabilizes the arc in this region. This chimney vent 15, located away from the opening volume, enables the arc to stabilize and not to re-strike repetitively between the contacts. It is therefore the conjunction of the shape of the recess and of the respective position of the fins with respect to one another that enables the arc to be displaced quickly and lastingly away from the contacts. [57] Moreover, a gas convection is established via the removal ducts 3, so that the progression of the arc towards the rear wall 6 is not hampered by a pressure increase. The arc foot migrates quickly from the stationary contact 32 to the chimney vent 15, before the movable contact 33 has reached its final separated position. In practice, the gases emitted at the periphery of the arc and present in the exchange spaces 2 are injected into the opening volume 35 via the outflow ducts composed of the removal holes 4, the removal ducts 3 and the openings 18. The homogeneous and regular distribution of the gases removed by the outflow ducts reduces the risk of pressure traps responsible for slowing down the progression of the gases and the progression of the arc. A local pressure increase or the presence of cold gases in front of the arc, can in fact result in the movement thereof being slowed down. [59] Flow of the gases in the outflow ducts in the direction of the electrical contacts 32, 33 of the opening volume 35 enables said compressed gases to be decompressed and to be cooled more quickly. [60] Injection of the cooled gases at the level of the contacts 32, 33 present in the opening volume 35 increases the dielectric strength in this space and thus prevents nuisance re-strikings of the electric arc. Furthermore, this injection at the level of the contacts enables the plasma present in the opening volume 35 and the arc chute 10 to be subjected to a backflow of cold and weakly ionized gases. This causes cooling of the rear zone of the arc but also results in the hot gases being sent on in front of the arc. On account of its cooling via the rear, the arc, tending to develop in the presence of ionized hot gases associated with metallic vapours, moves towards the rear face 6 of the arc chute 10 and thus moves away from the contact opening zone. [61] According to a first series of alternative embodiments as represented in figures 6A and 7A, the leading edge 5 running along the flat surface of the fins 1 and forming the recess 9 of asymmetric shape cuts the longitudinal axis 12 of said fins five times at the points a, b, c, d, e. Due to the asymmetric shape of the recesses 9 of each fin 1 and to the alternate stacking of said fins, two chimney vents 15 are formed the ducts 16 whereof appear respectively as being substantially closed in a plane xy perpendicular to the longitudinal axis 16 of said chimney vents 15. [62] According to a second series of alternative embodiments as represented in figures 10A and 10B, the leading edge 5 running along the flat surface of the fin and forming the recess 9 of asymmetric shape cuts the longitudinal axis 12 of said fin twice. In addition, the first tapered longitudinal portion 9a is positioned beyond the longitudinal axis 12 of the fins 1. [63] In another alternative embodiment as represented in figure 11, the exchange spaces 2 comprise at least one removal hole 4 placed in the rear wall 6 and connected to a removal duct 3. According to this embodiment, each exchange space 2 comprise two removal holes 4; each of the holes is respectively connected to a removal duct 3. [64] In another alternative embodiment, each hole 4 is connected in autonomous manner to an opening 18 via its own removal duct 3. Each removal duct 3 in fact remains independent from the other removal ducts. CLAIMS 1. Electrical switchgear device comprising: • a case (31) having a longitudinal geometric reference plane (xz), • a pair of separable electrical contacts (32, 33) arranged in an opening volume (35), • an arc chute (10) opening onto the opening volume (35) and being delineated by two parallel side walls (11) placed on each side of the geometric reference plane (xz), a rear wall (6) located away from the opening volume (35), a bottom wall (7) and a top wall (8), • at least two deionizing fins (1) having a leading edge (5) designed to be exposed to the arc and delineating an open recess (9) of asymmetric shape and forming two lateral branches (1a, 1b), said at least two fins being stacked alternately, the fins being placed inside the arc chute (10), characterized in that said recess (9) of said at least two fins (1) being achieved in such a way as to create at least one chimney vent the duct whereof appears to be substantially closed (15) in a plane (xy) perpendicular to the longitudinal axis (16) of said chimney vent (15). 2. Electrical switchgear device according to claim 1 characterized in that it comprises, along the z-axis (z), at least two alignment zones (a, b) between a lateral branch (1a) of a first fin (1) and at least one lateral branch (1a) of a second fin (1) having undergone a 180° rotation around its longitudinal axis (12) with respect to said first fin (1). 3. Electrical switchgear device according to claims 1 or 2 characterized in that the free leading edge (5) of the fins (1) is in contact at least twice with the longitudinal axis (12) of said fin. 4. Electrical switchgear device according to claim 3 characterized in that the free leading edge (5) of the fins (1) cuts the longitudinal axis (12) of said fin at least twice. 5. Electrical switchgear device according to claim 4 characterized in that there exists, along the z-axis (z), at least one overlap zone (50) between a lateral branch (1a) of a first fin (1) and at least one lateral branch (1a) of a second fin (1) having undergone a 180° rotation around its longitudinal axis (12) with respect to said first fin (1). 6. Electrical switchgear device according to any one of the foregoing claims characterized in that the free leading edge (5) of the recess (9) delineates a first tapered front portion (9a) opening out onto the opening volume (35) and a second longitudinal rear portion (9b) extending towards the rear wall (6), the first tapered front portion (9a) being cut by the longitudinal axis of the fins (12). 7. Electrical switchgear device according to any one of the foregoing claims characterized in that each fin (1) is positioned next to another fin (1) having undergone a 180° rotation with respect to its longitudinal axis (12). 8. Electrical switchgear device according to any one of the foregoing claims characterized in that at least one removal duct (3) is connected to at least one exchange space (2) separating two fins (1) via at least one removal hole (4), said at least one removal duct (3) extending from at least one removal hole (4) to an opening (18), along at least one side wall (11), said duct (3) comprising a substantially constant or increasing cross-section (A) along the x-axis (x) from the inlet of the gases to the outlet of the gases from said duct, said opening (18) being at least equal to the largest cross-section (A) of said duct (3) and being placed facing the electrical contacts (32, 33) of the opening volume (35). 9. Electrical switchgear device according to claim 8 characterized in that each exchange space (2) of the arc chute (10) comprises at least one removal hole (4) connected to at least one removal duct (3). 10. Electrical switchgear device according to claims 8 or 9 characterized in that it comprises at least two removal ducts (3), at least one duct (3) extending along each side wall (11) of the arc chute (10). 11. Electrical arc breaking device according to claim 10 characterized in that the exchange spaces (2) of the arc chute (10) comprise at least two removal holes (4), at least one hole being connected to each of the removal ducts (3) extending along each wall (11). 12. Electrical arc breaking device according to any one of the foregoing claims characterized in that the removal holes (4) are placed in a zone comprised between the rear wall (6) and the median axis (13) of the fins (1). 13. Electrical arc breaking device according to claim 12 characterized in that the removal holes (4) are placed in the side walls (11). 14. Electrical arc breaking device according to claim 12 characterized in that the removal holes (4) are placed in the rear wall (6). 15. Electrical switchgear device according to any one of the foregoing claims characterized in that the removal ducts (3) have a substantially parallelepipedic shape.

Documents:

1790-CHE-2005 AMENDED CLAIMS 03-11-2011.pdf

1790-CHE-2005 FORM-3 03-11-2011.pdf

1790-CHE-2005 POWER OF ATTORNEY 03-11-2011.pdf

1790-che-2005 abstract.pdf

1790-che-2005 claims.pdf

1790-CHE-2005 CORRESPONDENCE OTHERS 01-03-2011.pdf

1790-che-2005 correspondence others.pdf

1790-CHE-2005 CORRESPONDENCE PO.pdf

1790-che-2005 description (complete).pdf

1790-che-2005 drawings.pdf

1790-CHE-2005 EXAMINATION REPORT REPLY RECEIVED 03-11-2011.pdf

1790-che-2005 form-1.pdf

1790-che-2005 form-18.pdf

1790-che-2005 form-3.pdf

1790-che-2005 form-5.pdf

1790-che-2005 power of attorney.pdf

abstract 1790-che-2005.jpg