Terminal block with sealed interconnect system

• US 10,015,899 B2
• Filed: 06/29/2015
• Issued: 07/03/2018
• Est. Priority Date: 06/29/2015
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Hausler, George Charles, McCoy, Steven John, Eriksen, Christopher Lee, Cota, Jeffrey Alan
• Primary Examiner(s): Bui, Hung S
• Application Number:
  US14/753,119
• Publication Number:
  US 20160381822A1
• Time in Patent Office: 1,100 Days
• Field of Search: 361728, 361730, 361752, 361796
• CPC Class Codes: G01D 11/24 Housings ; Casings for instruments
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: H05K 5/0065 wherein modules are associated together, e.g. electromechanical assemblies, modular structures
• CPC Class Codes: H05K 5/069 Other details of the casing, e.g. wall structure, passage for a connector, a cable, a shaft
• CPC Class Codes: H05K 7/1428 for small modular apparatus with terminal block
• CPC Class Codes: H05K 7/1432 specially adapted for power drive units or power converters

Abstract

A process variable transmitter for use in an industrial process includes a housing having a cavity formed therein. The housing has a barrier which divides the cavity into first and second cavities. Preferably, measurement circuitry in the first cavity is configured to measure a process variable of the industrial process. A terminal block assembly is positioned in the second cavity. The terminal block assembly forms a seal with the housing thereby forming a third cavity between the barrier and a circuit board of the terminal block assembly.

Claims

1. A process variable transmitter for use in an industrial process, comprising:

a housing having a cavity formed therein, the housing including a barrier which divides the cavity into first and second cavities;

measurement circuitry in the first cavity configured to measure a process variable of the industrial process; and

a terminal block assembly in the second cavity, the terminal block assembly forming a seal with the housing thereby forming a third cavity between the barrier and a circuit board of the terminal block assembly, the terminal block assembly including a shroud member arranged to define the third cavity, wherein the third cavity formed between the barrier and the circuit board forms a compartment sealed from exposure to an environment in the second cavity.

2. The process variable transmitter of claim 1 wherein the shroud member comprises a metal shroud.

3. The process variable transmitter of claim 1 including a seal between the shroud member and the housing of the process variable transmitter.

4. The process variable transmitter of claim 3 wherein the seal comprises an O-ring.

5. The process variable transmitter of claim 1 wherein the circuit board carries at least one circuit component in the third cavity.

6. The process variable transmitter of claim 1 wherein the terminal block assembly includes a plurality of terminals for coupling to a two-wire process control loop.

7. The process variable transmitter of claim 1 wherein the process control loop is used to provide power to power the process variable transmitter.

8. The process variable transmitter of claim 1 including electrical conductors at least partially disposed within the barrier and extending into the third cavity to electrically connect the circuit board to the measurement circuitry.

9. The process variable transmitter of claim 8 wherein the shroud member includes an aperture formed therein wherein the electrical conductors extend through the aperature.

10. The process variable transmitter of claim 8 wherein the conductors carry power.

11. The process variable transmitter of claim 8 wherein the conductors carry a communication signal.

12. The process variable transmitter of claim 11 wherein the communication signal is in accordance with a two-wire process control loop communication standard.

13. The process variable transmitter of claim 11 wherein the communication signal is for use in communicating between components of the process variable transmitter.

14. The process variable transmitter of claim 8 wherein the conductors are arranged to compensate for misalignment.

15. The process variable transmitter of claim 14 wherein the misalignment occurs in a connection between the circuit board and the measurement circuitry.

16. The process variable transmitter of claim 8 wherein the connectors are mounted to the barrier.

17. The process variable transmitter of claim 8 wherein the connectors are mounted to the terminal block assembly.

18. The process variable transmitter of claim 17 wherein the circuit board includes a temperature sensor for use in compensating measurements.

19. The process variable transmitter of claim 1 wherein the barrier includes an opening and the terminal block is sealed against the opening.

20. The process variable transmitter of claim 1 wherein the circuit board carries a temperature sensor.

21. The process variable transmitter of claim 1 wherein the circuit board carries communication circuitry.

22. The process variable transmitter of claim 2 wherein the shroud member is soldered to the circuit board.

23. The process variable transmitter of claim 1 including at least one electrical connection between the circuit board and the measurement circuitry.

24. The process variable transmitter of claim 23 wherein the at least one electrical connection extends through the barrier.

25. The process variable transmitter of claim 1 wherein the terminal block includes an alignment feature for alignment with the housing.

26. The process variable transmitter of claim 1 including first and second end caps configured to enclose the respective first and second cavities of the housing.

27. The process variable transmitter of claim 1 including a process variable sensor coupled to the measurement circuitry for use in measuring the process variable.

28. The process variable transmitter of claim 1 wherein the circuit board carries temperature measurement circuitry configured to couple to an external temperature sensor.