SHIELDED DOUBLE-COIL MULTILAYER ASSEMBLY FOR INDUCTIVE DETECTOR

• US 20130057300A1
• Filed: 08/14/2012
• Published: 03/07/2013
• Est. Priority Date: 09/02/2011
• Status: Active Grant

• Current Assignee: Tmss France
• Original Assignee: Schneider Electric Industries SAS (Schneider Electric SE)
• Inventors: BERNARD, Jacques, Charrier, Pierre-Marie
• Granted Patent: US 9,182,514 B2
• Time in Patent Office: Days
• US Class Current: 324/629
• CPC Class Codes: G01V 3/107 using compensating coil or loop arrangements

Abstract

The invention relates to a shielded double-coil multilayer assembly intended to be used in an inductive detector. This multilayer assembly comprises a plurality of stacked parallel separated layers, namely:

• • a layer (C1) comprising a first shielding element for a first coil,
  • a layer (C2) comprising all or part of a first coil,
  • a layer (C3) comprising all or part of a second coil,
  • a layer (C4) comprising a first shielding element for the second coil.

Claims

1. Multilayer assembly intended to be used in an inductive detector, characterized in that it comprises at least four stacked parallel separated layers, namely:

a layer (C1, C10, C100) comprising a first shielding element for a first coil,

a layer (C2, C20, C200) comprising a first coil,

a layer (C3, C50, C600) comprising a second coil,

a layer (C4, C60, C800) comprising a first shielding element for the second coil,

and in that said layers are separated from one another by connecting layers (CL), one of said connecting layers, referred to as an intermediate connecting layer (CLm), having a determined thickness (e) greater than those of the connecting layers (CL) separating the other layers from one another.

2. Multilayer assembly according to claim 1, characterized in that it comprises an additional layer (C30, C400) comprising a second element for shielding the first coil.

3. Multilayer assembly according to claim 1 or 2, characterized in that it comprises an additional layer (C40, C500) comprising a second element for shielding the second coil.

4. Multilayer assembly according to one of claims 1 to 3, characterized in that it comprises an additional layer (C300) comprising a coil connected to the first coil.

5. Multilayer assembly according to one of claims 1 to 4, characterized in that it comprises an additional layer (C700) comprising a coil connected to the second coil.

6. Multilayer assembly according to one of claims 1 to 5, characterized in that each coil is surrounded by an open shielding ring.

7. Multilayer assembly according to one of claims 1 to 6, characterized in that it is formed by a monobloc multilayer printed circuit.

8. Multilayer assembly according to one of claims 1 to 6, characterized in that it comprises a first multilayer printed circuit (Ci1), a spacer strip (E) forming the intermediate connecting layer (CLm) and a second multilayer printed circuit (Ci2), which are assembled together.

9. Inductive proximity detector comprising a casing in which an oscillating circuit (1) is placed which is excited in resonance by a generator (2) and comprising a detection coil (10) sensitive to a metal target (4) to be detected, the oscillating circuit (1) comprising a reference coil (11) arranged in order to have a mutual inductance, with respect to the metal target (4) to be detected, which is substantially less than that of the detection coil (10) with respect to the metal target (4), the detector comprising processing means (3) connected to the coils (10, 11) and making it possible to determine the presence or absence of the metal target (4) in proximity to the detector, characterized in that it comprises a multilayer assembly as defined in one of the preceding claims in its casing, and in that the detection coil (10) is produced in the second layer of the multilayer assembly and the reference coil is formed in the third layer of the multilayer assembly.