GB2102207A - Electrical circuit assembly - Google Patents
Electrical circuit assembly Download PDFInfo
- Publication number
- GB2102207A GB2102207A GB08122169A GB8122169A GB2102207A GB 2102207 A GB2102207 A GB 2102207A GB 08122169 A GB08122169 A GB 08122169A GB 8122169 A GB8122169 A GB 8122169A GB 2102207 A GB2102207 A GB 2102207A
- Authority
- GB
- United Kingdom
- Prior art keywords
- circuit assembly
- intermediate material
- metal casing
- electrical
- electrically conductive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0007—Casings
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- H10W42/00—Arrangements for protection of devices
- H10W42/60—Arrangements for protection of devices protecting against electrostatic charges or discharges, e.g. Faraday shields
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Casings For Electric Apparatus (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
- Patch Boards (AREA)
- Gas-Insulated Switchgears (AREA)
Abstract
An electrical circuit assembly having a high voltage component 10 encapsulated in a dielectric potting compound 11, and having a metal casing 13, whereby electrical charge is leaked away, has a deformable material 15 intermediate between the casing and the encapsulation, the intermediate material remaining contiguous with the adjacent portions of the encapsulation, and remaining contiguous with at least some of the adjacent portions of the casing, under normally encountered variations of temperature. The intermediate material may be sufficiently electrically conductive enabling the charge to be leaked away at a rate ensuring that discharges do not occur in spaces within the circuit assembly, for example, the intermediate material comprising a foam of a plastics material with an electrically conductive filler. Whether, electrically conductive, or not, the intermediate material may be resilient; and/or may be adherent. <IMAGE>
Description
SPECIFICATION
Electrical circuit assemblies
This invention relates to electrical circuit
assemblies, and in particular to such assemblies
each having a constituent electrical component to
be energised by a high voltage supply, of greater
than 3000 volts, and the component is
encapsulated in solid dielectric potting compound,
such as a silicone rubber.
Under normally encountered operating
conditions for such an electrical circuit assembly,
and when the component is solely encapsulated in
a solid dielectric potting compound, an electrical
charge occurs on the surface of the dielectric
encapsulant remote from the component, unless
precautions are taken to remove this charge. If the
charge is not removed, corona or arc discharges
can occur, generating undesirable electrical noise,
by generating electrical fields, which electrical
fields adversely affect the performance of the
circuit assembly. The discharges possibly also
damage the dielectric encapsulant.It is known to
cause the leakage of this surface charge away
from the circuit assembly, in order to prevent
discharges, by providing the encapsulated
component with a metal casing, also comprising
part of the circuit assembly the metal casing being
contiguous with the dielectric encapsulant, and
being connected to a member external of the
circuit assembly maintained at zero potential. The
provision of such a metal casing is also
advantageous because it shields the component
from electrical fields external of the circuit
assembly, and generated in any way; it provides
the circuit assembly with mechanical strength;
and it facilitates the mounting of the circuit
assembly upon other members.However, the
inevitable different coefficients of expansion for
the metal of the casing, and for the dielectric
encapsulation, under normally encountered
variations of temperature, can cause the casing to
pull away from adjacent portions of the dielectric
encapsulation, whereby spaces are formed
inadvertently, in which spaces discharges can
occur. This effect can be reduced by providing a
flixible casing, but this solution may not be
desirable if the flexible casing does not provide the
circuit assembly with a required amount of
mechanical strength, or the flexible casing cannot be used satisfactorily to facilitate any required
mounting of the circuit assembly upon other
members.
For an electrical assembly in which a
constituent electrical component is to be
energised by a high voltage supply, the component
is encapsulated in a solid dielectric potting
compound, and metal casing is provided for the
encapsulated component, the metal casing to be
connected to a member external of the circuit assembly, maintained at zero potential, the metal
casing being provided to enable electrical charge,
occurring on the surface of the dielectric
encapsulant remote from the component, to lead
away from the circuit assembly, it is an object of
the present invention to provide a novel and
advantageous circuit assembly construction, such
that the metal casing operates effectively in
preventing electrical discharges in spaces within
the circuit assembly, under all normally
encountered operating conditions, whilst the
metal casing can be arranged to have any required
mechanical strength, and can be arranged to be
used for mounting the circuit assembly upon other
members, if desired.
According to the present invention an electricat circuit assembly, comprising at least one electrical
component to be energised by a high voltage
supply, the component being encapsulated in a
dielectric potting compound, and a metal casing
being provided for the encapsulated component,
also is provided with a deformable material
intermediate between the dielectric encapsulant
and the metal casing, the arrangement being such
that, under all normally encountered operating
conditions for the circuit assembly, the
intermediate material remains contiguous with
adjacent portions of the dielectric encapsulant,
and remains contiguous with at least some of the adjacent portions of the metal casing, and electrical discharges do not occur in spaces within the circuit assembly.
It is essential to ensure, in any one, or any combination, of the possible ways referred to below, that the spaces cannot occur, at least, at the interface between the dielectric encapsulant and the deformable intermediate material, under all normally encountered operating conditions, if such a feature cannot be obtained as an inherent characteristic of the construction of the electrical circuit assembly.
It is also essential that the intermediate material is electrically conductive if spaces can be within the intermediate material, or at the interface between the metal casing and the intermediate material, possibly such spaces being formed inadvertently under normally encountered operating conditions. In these circumstances it is required that the intermediate material is sufficiently electrically conductive, and remains sufficiently in contact with the metal casing, for the electrical charge, which otherwise would occur on the surface of the solid dielectric encapsulant, to be leaked away at a rate ensuring that discharges cannot occur within the intermediate material, or at the interface between the casing and the intermediate material.When the intermediate material is a resiliently deformable foam material, it is essential that the electrical charge is leaked away at a rate, at least, to ensure that discharges cannot occur within the spaces within the foam, under all normally encountered operating conditions. When the deformable, electrically conductive intermediate material includes a plastics material, and irrespective of whether it is also resilient or not, it can be rendered electrically conductive by also including an electrically conductive filler of any suitable form.In general, the deformable, electrically conductive, intermediate material is
required to prevent spaces occurring, and/or being formed inadvertently, within the circuit assembly
under all normally encountered operating conditions; and/or is required to be sufficiently electrically conductive; to ensure that discharges do not occur within the circuit assembly.
If the deformable intermediate material is not electrically conductive, it can be considered to be part of the dielectric encapsulant, and would have the electrical charge occurring on its surface remote from the encapsulated component, instead of on the surface of the main part of the dielectric encapsulant, if the arrangement is not such that this surface charge leaks away via the metal casing. However, it is essential that no spaces are provided, or can be formed inadvertently, at the interface between the intermediate material and the metal casing, nor within the intermediate material, under all normally encountered operating conditions for the electrical circuit assembly.
The intermediate material, whether electrically conductive, or not, and irrespective of whether it is a foam material, or not, may be resiliently deformable.
With a resiliently intermediate deformable material, spaces are less likely to occur at the interfaces of the intermediate material with the dielectric encapsulant, and with the metal casing, than otherwise would be the case.
In any arrangement, the deformable intermediate material may at least include a plastics material, such as a polyurethane.
Desirably, the deformable intermediate material has a composition enabling it to adhere, in any manner, to the dielectric encapsulant, and/or to the metal casing. In this way, and irrespective of whether the deformable intermediate material is resilient, or not, possibly it can be ensured that no spaces occur at each interface at which the intermediate material is adherent. For example, when the intermediate material at least includes a polyurethane, and the solid dielectric encapsulant is a silicone rubber, the intermediate material may have a rough surface, enabling it to adhere by being keyed to the contiguous portions of the dielectric encapsulant.
The present invention will now be described by way of example with reference to the accompanying drawing, which indicates generally a cross-sedtion of one embodiment of an electrical circuit assembly in accordance with the present invention.
The illustrated electrical circuit assembly includes a plurality of electrical components, indicated generally at 10, and to be energised by a high voltage supply, now shown, of, for example, 15,000 volts. The components 10 are encapsulated in a dielectric potting compound 11, for example, a silicone rubber, or a solid resin of a plastics material. If in the circuit assembly the components 10 are solely encapsulated in the dielectric potting compound ii; under normally encountered operating conditions, an electrical charge occurs on the surface 1 2 of the dielectric encapsulant remote from the components. Such a charge can cause corona or arc discharges, generating undesirable electrical noise, by generating electrical fields, which electrical fields adversely affect the performance of the circuit assembly.Further, such discharges can damage the dielectric encapsulant.
It is known to provide a metal casing for the electrical circuit assembly including the encapsulated component, as indicated at 13, and for example of aluminium. The metal casing 13 is connected to a member, indicated generally at 14, external of the circuit assembly, and maintained at zero potential. Thus, if the metal casing 13 is contiguous with the dieletric encapsulant, the charge on the surface of the dielectric encapsulant is leaked away, preventing electrical discharges.
The provision of such a casing is also advantageous because it shields the components from electrical fields external of the circuit assembly, and generated in any way; it provides the circuit assembly with mechanical strength; and it facilitates the mounting of the circuit assembly upon other members. However, the inevitable different coefficients of expansion for the metal of the casing, and for the dielectric encapsulant, under normally encountered variation of temperature, can cause the dielectric encapsulant to pull away from the casing, inadvertently forming spaces in which discharges can occur.It is known to reduce this effect by providing a flexible casing, but this solution may not be desirable if the flexible casing does not provide the circuit assembly with a required amount of mechanical strength, or if the flexible casing cannot be used satisfactorily to facilitate any required mounting of the circuit assembly upon other members.
In accordance with the present invention, the known construction for a circuit assembly, referred to above, is modified in the manner shown in the accompanying drawing, by providing a resiliently deformable, electrically conductive, material 15, intermediate between the dieletric encapsulant 11 and the metal casing 13.
The arrangement is such that spaces cannot occur, at least, at the interface between the dielectric encapsulant and the deformable intermediate material, under all normally encountered operating conditions for the electrical circuit assembly. This feature may be obtained as an inherent characteristic of the construction of the electrical circuit assembly, or in any one, or any combination, of the possible ways referred to below.
The resiliently deformable intermediate material comprises a foam material, including spaces in which discharges can occur. Thus, the foam intermediate material is required to be sufficiently electrically conductive, and to remain sufficiently in contact with the metal casing, to ensure that the charge is leaked away at a rate ensuring that discharges cannot occur, at least, in these spaces. An intermediate material including a plastics material, such as the foam material referred to above, can be rendered electrically
conductive by the intermediate material also
including an electrically conductive filler of any
suitable form, such as carbon..
The intermediate material 15 is sufficiently
resiliently deformable, and the construction of the
circuit assembly is such, that the intermediate
material remains contiguous with both the
dielectric encapsulant, and with the metal casing,
under all normally encountered operating
conditions for the circuit assembly, without spaces
being left, or being formed inadvertently, at the
interfaces between the intermediate material and
both the dielectric encapsulant and the metal casing, within which spaces discharges can occur.
Usually, the arrangement is such that the
intermediate material is resiliently deformed under all normally encountered operating conditions.
Alternatively, the arrangement may be such that spaces can occur inadvertently at the intermediate material-metal casing interface, and the intermediate material is required to be sufficiently electrically conductive, and to remain sufficiently in contact with the metal casing, so that electrical discharges cannot occur within such spaces.
An intermediate material including a plastics material, for example, a polyurethane, is also advantageous because it has a rough surface, possibly enabling it to adhere, by being keyed, to the contiguous portions of the dielectric encapsulant, for example, when the dielectric encapsulant comprises a silicone rubber.
It is desirable, but not essential, for the intermediate material to have composition enabling it to adhere, in any manner, to the dielectric encapsulant, and/or to the metal casing, complementing the resilience of the intermediate material, in ensuring that the intermediate material remains contiguous with adjacent portions of the dielectric encapsulant, and remains contiguous with at least some of the adjacent portions of the metal casing, under all normally encountered operating conditions for the circuit assembly.
In general, the intermediate material is required to prevent spaces occurring, and/or being formed inadvertently within the circuit assembly under all normally encountered operating conditions; and/or is required to be sufficiently electrically conductive; to ensure that discharges do not occur within the circuit assembly.
The provision of the intermediate material within the circuit assembly enables the metal casing to have any required mechanical strength.
The provided strength no longer is at least partially restricted by the need for the casing to flex, in order to be able satisfactorily, to leak away electrical charges on the surface of the dielectric encapsulant, under all normally encountered operating conditions for the circuit assembly. In addition, the metal casing can have any form to facilitate the mounting of the circuit assembly upon other members.
It is desirable, but not essential, that the metal casing is a complete closure member for the encapsulated components. The construction of an electrical circuit assembly in accordance with the present invention, in this respect, is required to be such that electrical charge, which otherwise would occur on any surface portion of the dielectric encapsulation, leaks away at a rate ensuring that discharges cannot occur.
The arrangement may be such that the intermediate material does not wholly surround the encapsulated components, for example, if part of the metal casing is flexible, and so convenientlyis contiguous with the dielectric encapsulant; and/or if part of the metal casing is not likely to be pulled away from adjacent portions of the dielectric encapsulant with which it is contiguous; and/or if the arrangementis such that, with the incomplete covering of the intermediate material provided, the electrical charge which otherwise would occur on the surface of the dielectric encapsulant is leaked away at a rate ensuring that discharges cannot occur in spaces within the circuit assembly, possibly such spaces being formed inadvertently.
The arrangement also may be such that the intermediate material is not a foam material, but spaces may be left within the circuit assembly, and/or spaces can be formed inadvertently under normally encountered operating conditions for the circuit assembly, it being essential that such spaces are remote from the intermediate material dielectric encapsulant interface, so that it is required that the intermediate material is sufficiently electrically conductive, and remains sufficiently in contact with the metal casing, to ensure that discharges cannot occur within these spaces.
If spaces do not occur within the circuit assembly, the intermediate material may not be electrically conductive. With such an arrangement the intermediate material can be considered to be part of the dielectric encapsulant, and would have the elecrrical charge on its surface remote from the encapsulated components, if the arrangment is not such that this surface charge leaks away via the metal casing. With such an arrangement the intermediate material cannot be a foam.
The intermediate material, whether electrically conductive or not, may be resilient otherwise than by comprising a foam.
The intermediate material may not be resilient, but is required to be deformable.
If the intermediate material is sufficiently adherent to the dielectric encapsulant; and/or to the metal casing, it may not be required also to be resilient; and irrespective of whether the intermediate material is electrically conductive, or not.
The intermediate material, whether resilient or not, may not be adherent to the dielectric encapsulant; and/or to the metal casing.
Claims (12)
1. An electrical circuit assembly, comprising at least one electrical component to be energised by a high voltage supply, the component being encapsulated in a dielectric potting compound, and a metal casing being provided for the encapsulated component, the circuit assembly also being provided with a deformable material intermediate between the dielectric encapsulant and the metal casing, the arrangement being such that, under all normally encountered operating conditions for the circuit assembly, the intermediate material remains contiguous with adjacent portions of the dielectric encapsulant, and remains contiguous with at least some of the adjacent portions of the metal casing, and electrical discharges do not occur in places within the circuit assembly.
2. A circuit assembly as claimed in claim 1 in which the deformable intermediate material is electrically conductive.
3. A circuit assembly as claimed in claim 2 in which the intermediate material is a resiliently deformable foam material.
4. A circuit assembly as claimed in claim 2 or claim 3 having the deformable intermediate
material including a plastics material, which is
rendered electrically conductive by also including
an electrically conductive filler.
5. A circuit assembly as claimed in claim 1 in which the intermediate material is a dielectric, and
no spaces are provided, or can occur, at the interface between the intermediate material and the metal casing, not within the intermediate
material, under all normally encountered operating conditions for the circuit assembly.
6. A circuit assembly as claimed in any one of the preceding claims in which the intermediate material is resiliently deformable.
7. A circuit assembly as claimed in any one of the preceding claims in which the deformable intermediate material is a plastics material.
8. A circuit assembly as claimed in claim 7 in which the plastics material is a polyurethane.
9. A circuit assembly as claimed in any one of the preceding claims in which the deformable intermediate material has a composition enabling it to adhere to the dielectric encapsulant, and/or to the metal casing.
10. A circuit assembly as claimed in claim 9 in which the intermediate material is keyed to the contiguous portions of the dielectric encapsulant.
11. A circuit assembly as claimed in any one of the preceding claims in which the dielectric encapsulant comprises a silicone rubber.
12. An electrical circuit assembly substantially as described herein with reference to the accompanying drawing.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08122169A GB2102207B (en) | 1981-07-17 | 1981-07-17 | Electrical circuit assembly |
| SE8204203A SE8204203L (en) | 1981-07-17 | 1982-07-07 | ELECTRIC CIRCUIT |
| DE19823225612 DE3225612A1 (en) | 1981-07-17 | 1982-07-08 | ELECTRICAL CIRCUIT COMPONENT |
| FR8212444A FR2509948A1 (en) | 1981-07-17 | 1982-07-16 | ELECTRICAL CIRCUIT ASSEMBLY COMPRISING AT LEAST ONE ENROBE COMPONENT |
| NL8202888A NL8202888A (en) | 1981-07-17 | 1982-07-16 | ELECTRIC SWITCHING DEVICE. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08122169A GB2102207B (en) | 1981-07-17 | 1981-07-17 | Electrical circuit assembly |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2102207A true GB2102207A (en) | 1983-01-26 |
| GB2102207B GB2102207B (en) | 1985-04-17 |
Family
ID=10523333
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08122169A Expired GB2102207B (en) | 1981-07-17 | 1981-07-17 | Electrical circuit assembly |
Country Status (5)
| Country | Link |
|---|---|
| DE (1) | DE3225612A1 (en) |
| FR (1) | FR2509948A1 (en) |
| GB (1) | GB2102207B (en) |
| NL (1) | NL8202888A (en) |
| SE (1) | SE8204203L (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2569836A1 (en) * | 1984-08-31 | 1986-03-07 | Barnaulskoe Ok | Wire diameter measuring system |
| GB2237937A (en) * | 1989-11-07 | 1991-05-15 | Ryan Mining Services Limited | Electric switch for use in hazardous environments |
| WO2002089151A1 (en) * | 2001-04-26 | 2002-11-07 | Chemque, Incorporated | Polymeric foam gaskets and seals |
| GB2382232A (en) * | 2001-11-16 | 2003-05-21 | Honda Motor Co Ltd | High voltage electrical packaging box structure |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT386720B (en) * | 1986-05-27 | 1988-10-10 | Alcatel Austria Ag | SHIELDED HOUSING |
| DE4224122C2 (en) * | 1992-07-22 | 1995-11-02 | Turck Werner Kg | Electronic circuit cast in a housing |
| DE102013226463A1 (en) * | 2013-12-18 | 2014-10-02 | Siemens Aktiengesellschaft | High voltage component |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE623125A (en) * | ||||
| US2379942A (en) * | 1942-12-31 | 1945-07-10 | Bell Telephone Labor Inc | Cable terminating means |
| US3153694A (en) * | 1959-06-02 | 1964-10-20 | Joseph R Tomlinson | Encapsulation of electronic circuits |
| FR1598441A (en) * | 1968-12-13 | 1970-07-06 |
-
1981
- 1981-07-17 GB GB08122169A patent/GB2102207B/en not_active Expired
-
1982
- 1982-07-07 SE SE8204203A patent/SE8204203L/en not_active Application Discontinuation
- 1982-07-08 DE DE19823225612 patent/DE3225612A1/en not_active Withdrawn
- 1982-07-16 FR FR8212444A patent/FR2509948A1/en active Pending
- 1982-07-16 NL NL8202888A patent/NL8202888A/en not_active Application Discontinuation
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2569836A1 (en) * | 1984-08-31 | 1986-03-07 | Barnaulskoe Ok | Wire diameter measuring system |
| GB2237937A (en) * | 1989-11-07 | 1991-05-15 | Ryan Mining Services Limited | Electric switch for use in hazardous environments |
| US6646199B2 (en) | 1999-10-20 | 2003-11-11 | Chemque, Inc. | Polymeric foam gaskets and seals |
| WO2002089151A1 (en) * | 2001-04-26 | 2002-11-07 | Chemque, Incorporated | Polymeric foam gaskets and seals |
| GB2382232A (en) * | 2001-11-16 | 2003-05-21 | Honda Motor Co Ltd | High voltage electrical packaging box structure |
| GB2382232B (en) * | 2001-11-16 | 2004-02-25 | Honda Motor Co Ltd | High voltage electrical packaging box structure |
| US6798658B2 (en) | 2001-11-16 | 2004-09-28 | Honda Giken Kogyo Kabushiki Kaisha | High voltage electrical packaging box structure |
| DE10252810B4 (en) * | 2001-11-16 | 2014-05-08 | Honda Giken Kogyo K.K. | High Voltage Electrical-pack box structure |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2509948A1 (en) | 1983-01-21 |
| DE3225612A1 (en) | 1983-02-03 |
| NL8202888A (en) | 1983-02-16 |
| SE8204203L (en) | 1983-01-18 |
| SE8204203D0 (en) | 1982-07-07 |
| GB2102207B (en) | 1985-04-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3879936B2 (en) | Shield housing and shield housing manufacturing method | |
| EP2059980B1 (en) | Electrical connector with esd protection | |
| US9071005B2 (en) | Terminal block and electronic device comprising same | |
| US7473845B2 (en) | Structural unit and method for the production of a structural unit | |
| US5578790A (en) | Shielding gasket | |
| JPH03104195A (en) | Sealing and shielding structure | |
| GB2102207A (en) | Electrical circuit assembly | |
| KR102507285B1 (en) | Sealing arrangement and its use | |
| US3559141A (en) | Underground electric power cable fuse housing having a semi-conductive corona shield | |
| CN113597653A (en) | Vacuum capacitor | |
| KR20190010418A (en) | High power relay assembly | |
| EP0075455B1 (en) | Power source terminal assembly | |
| US5057030A (en) | Grommet/seal member for a connector assembly | |
| CN102856847A (en) | Connection arrangement for an electric cable | |
| US4773871A (en) | High voltage bulkhead coupling | |
| CN209982918U (en) | Novel electronic information equipment case | |
| EP0046303B1 (en) | Disconnect contact assembly | |
| US4195278A (en) | High voltage terminal structure and flyback transformer | |
| MY107209A (en) | High voltage transformer for a television receiver | |
| US20080083562A1 (en) | Integrated emc gasket for electrical enclosure | |
| CN213784021U (en) | Electromagnetic shielding structure, electric device and air purifier | |
| US1610903A (en) | Insulated terminal for electrical apparatus | |
| US3716661A (en) | Cathode ray tube module | |
| CN1145179C (en) | Internal combustion engine ignition equipment | |
| EP3561842A1 (en) | Electromechanical actuator and high voltage (hv) switch |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19950717 |