Housing for a Field Device of Automation Technology

Patent metadata

Field	Value
Publication number	US-2016183397-A1
Application number	US-201514969148-A
Country	US
Kind code	A1
Filing date	Dec 15, 2015
Priority date	Dec 22, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

The invention relates to a housing for a field device of automation technology with a screwed connection, which connects a first housing part ( 2 ) with an external thread ( 3 ) with a second housing part ( 4 ) with an internal thread ( 5 ). In such case, the screwed connection provides a transition impedance lessened for EMC disturbance signals. The reduction of the transition impedance is achieved according to the invention by including in the screw thread a screw thread segment ( 6 ), in which a second screw thread type is designed in contrast to a first screw thread type located outside of the screw thread segment to provide a lessened transition impedance. Besides the basic provision that the screw thread is electrically conductive at least in corresponding portions, the second screw thread type can be differently embodied, in order to achieve the lessened transition impedance. This can occur, on the one hand, by providing the second screw thread type as round threads. However, other forms of embodiment of the screw thread segment are possible.

First claim

1 . Housing for a field device of automation technology with a screwed connection, which connects a first housing part ( 2 ) with an external thread ( 3 ) with a second housing part ( 4 ) with an internal thread ( 5 ), wherein the external thread ( 3 ) and the internal thread ( 5 ) have a first screw thread type with a first thread side-form, which first screw thread type is embodied in such a manner that the external thread ( 3 ) and the internal thread ( 5 ) form a force interlocking, screwed connection, and wherein the external thread ( 3 ) and the internal thread ( 5 ) are electrically conductive at least in corresponding portions of the surface, and wherein the external thread ( 3 ) and/or the internal thread ( 5 ) have/has at least one screw thread segment ( 6 ) of at least one winding of a second screw thread type, which is compatible with the first screw thread type and which has a second thread side-form, wherein the second screw thread type is embodied in such a manner that the transition impedance between the two housing parts ( 2 , 4 ) is lessened in comparison with the first screw thread type.

2 . Housing as claimed in claim 1 , wherein for the case, in which the external thread ( 3 ) and the internal thread ( 5 ) have the screw thread segment ( 6 ), the two screw thread segments ( 6 ) at least approximately coincide with one another in the screwed state.

3 . Housing as claimed in claim 1 , wherein the first housing part ( 2 ) or the second housing part ( 4 ) is a housing lid.

4 . Housing as claimed in claim 1 , wherein the first housing part ( 2 ) and/or the second housing part ( 4 ) are/is manufactured of a metal material.

5 . Housing as claimed in claim 1 , wherein the first housing part ( 2 ) and/or the second housing part ( 4 ) are/is manufactured of a synthetic material or a composite material.

6 . Housing as claimed in claim 5 , wherein the corresponding portions of the surfaces of the internal thread ( 5 ) and the external thread ( 3 ) comprise a metalizing layer.

7 . Housing as claimed in claim 1 , wherein the first screw thread type is a trapezoidal thread according to DIN 6063-2.

8 . Housing as claimed in claim 1 , wherein the at least one screw thread segment ( 6 ) of the at least one winding of the second screw thread type lie/lies in one of the end regions of the internal thread ( 5 ) and/or the external thread ( 3 ).

9 . Housing as claimed in claim 1 , wherein the second screw thread type is a round thread according to DIN 405.

10 . Housing as claimed in claim 1 , wherein the second thread side-form is embodied asymmetrically in such a manner that it has a first side ( 7 ), which lies in front in the screwing direction and which is rounded, and a second side ( 8 ), which lies behind in the screwing direction and which is flat.

11 . Housing as claimed in claim 8 , wherein the first screw thread type has on the external thread ( 3 ) a first outer radius ( 9 ), which is constant, and wherein the second screw thread type has on the external thread ( 3 ) a first inner radius ( 10 ), which is constant, and wherein the second screw thread type has on the external thread ( 3 ) a second outer radius ( 11 ), which in at least one of the two end regions of the thread is identical to the first inner radius ( 10 ) and which increases along the screw thread segment ( 6 ) of the at least one winding with a fixed slope from the first inner radius ( 10 ) on the first outer radius ( 9 ).

12 . Housing as claimed in claim 8 , wherein the first screw thread type has on the internal thread ( 5 ) a second inner radius ( 12 ), which is constant, and wherein the second screw thread type has on the internal thread ( 5 ) a third outer radius ( 13 ), which is constant, and wherein the second screw thread type has on the internal thread ( 5 ) a fourth outer radius ( 14 ), which is in at least one of the two end regions of the thread identical to the third outer radius ( 13 ), and which fourth outer radius ( 14 ) decreases along the screw thread segment ( 6 ) of the at least one winding with a fixed slope from the third outer radius ( 13 ) to the second inner radius ( 12 ).

Assignees

• Endress & Hauser Gmbh & Co Kg

Inventors

• Ingenhoven Benjamin
• Blodt Thomas

Classifications

• G01K1/08

  Protective devices, e.g. casings · CPC title

• G01K1/14

  Supports; Fastening devices; Arrangements for mounting thermometers in particular locations · CPC title

• G01D11/24 Primary

  Housings {; Casings for instruments} · CPC title

• H05K5/04

  Metal casings · CPC title

• H05K5/0247

  Electrical details of casings, e.g. terminals, passages for cables or wiring · CPC title