Explosion-proof assembly and method for producing same

Patent metadata

Field	Value
Publication number	US-10312674-B2
Application number	US-201615748544-A
Country	US
Kind code	B2
Filing date	Jul 5, 2016
Priority date	Jul 28, 2015
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

An explosion-proof arrangement ( 20 ) having a bushing part ( 23 ) with a bushing opening ( 24 ) that defines a bushing surface ( 25 ) and a structural unit ( 29 ) arranged in the bushing opening ( 24 ). The structural unit ( 29 ) includes a deformable inner body ( 31 ) with at least one conductor channel ( 32 ) extending through in a longitudinal direction (L), and a plastically deformable connecting sleeve ( 30 ) surrounding the inner body ( 31 ). At least one conductor ( 21 ) is guided through its own associated conductor channel ( 32 ) in the inner body ( 31 ). A connecting portion ( 33 ) of the connecting sleeve ( 30 ) is plastically deformed so that it presses radially inwardly on the inner body ( 31 ) and deforms it in a radial direction (R). A first delimiting surface ( 35 ) is formed on an outer circumference of the plastically deformed connecting portion ( 33 ). The bushing surface ( 25 ) forms a second delimiting surface ( 36 ). By arranging the structural unit ( 29 ) with the first delimiting surface ( 35 ) in the bushing opening ( 24 ), a flameproof Ex gap ( 37 ) is produced between the two delimiting surfaces ( 35, 36 ).

First claim

The invention claimed is:

1. An explosion-proof assembly ( 20 ) comprising:
a bushing part ( 23 ) having a bushing opening ( 24 ) with a bushing surface ( 25 ),
an inner body ( 31 ) made of a deformable material having at least one conductor channel ( 32 ) extending through the inner body ( 31 ) in a longitudinal direction (L),
at least one conductor ( 21 ) extending through the at least one conductor channel ( 32 ) and having at least one electrical and/or optical conductor lead ( 22 ),
said inner body ( 31 ) being surrounded by a connecting sleeve ( 30 ) in a circumferential direction (U) about the longitudinal direction (L), said connecting sleeve ( 30 ) being made of a plastically deformable material and pressing inwardly on the inner body ( 31 ) as a result of plastic deformation of a connecting portion ( 33 ) of the inner body ( 31 ) which connects the inner body ( 31 ) to the conductor ( 21 ) in a frictionally engaged manner, and
said plastically deformed connecting portion ( 33 ) of said connecting sleeve ( 30 ) having a plastic deformed outer surface ( 34 ) that defines a first delimiting surface ( 35 ) which forms a flameproof [Ex] gap ( 37 ) with a second delimiting surface ( 36 ) defined by said bushing surface ( 25 ) configured to prevent any flame transmission through the [EX] gap.

2. The explosion-proof assembly of claim 1 in which said connecting sleeve ( 30 ) rests directly against the inner body ( 31 ) without a first flameproof gap.

3. The explosion-proof assembly of claim 2 in which said inner body ( 31 ) engages said at least one conductor ( 21 ) with a flameproof connection, and said first delimiting surface is arranged coaxially relative to where the flameproof connection between the inner body ( 31 ) and the at least one conductor ( 21 ).

4. The explosion-proof assembly of claim 1 in which said at least one conductor ( 21 ) extends through said inner body ( 31 ) with a flameproof encapsulation [Ex d] about the at least one conductor ( 21 ).

5. The explosion-proof assembly of claim 1 in which said flameproof [Ex] gap ( 37 ) is an aft gap.

6. The explosion-proof assembly of claim 1 in which said first delimiting surface and said second delimiting surface both are surfaces without indentations or protrusions.

7. The explosion-proof assembly of claim 6 in which said first delimiting surface and said second delimiting surface each have a curved contour without vertices.

8. The explosion-proof assembly of claim 1 in which the length of the connecting portion ( 33 ) is more than 70[%] percent of the length of the connecting sleeve ( 30 ).

9. The explosion-proof assembly of claim 1 in which the length of said connecting sleeve ( 30 ) in the longitudinal direction (L) is a different length, greater or smaller, than the length of the inner body ( 31 ).

10. The explosion-proof assembly of claim 1 in which the connecting sleeve ( 30 ) at each of its opposite axial longitudinal ends has at least one radial protrusion ( 41 ) protruding inwardly in a radial direction (R) relative to the longitudinal direction (L).

11. The explosion-proof assembly of claim 10 in which said inner body ( 31 ) is arranged in the longitudinal direction (L) between two rigid radial holding plates ( 43 ), said holding plates ( 43 ) having a radial dimension in a radial direction (R) at right angles to the longitudinal direction (L) that is smaller than the radial dimension of the inner body ( 31 ) prior to the plastic deformation of the connecting portion ( 33 ).

12. The explosion-proof assembly of claim 11 in which said holding plates ( 43 ) are each arranged between the at least one radial protrusion ( 41 ) and the inner body ( 31 ).

13. The explosion-proof assembly of claim 1 in which said at least one conductor ( 21 ) has a plurality of conductors leads ( 22 ) which are each guided separately through a respective conductor channel ( 23 ) is the deformable inner body ( 31 ).

14. The explosion-proof assembly of claim 1 including a securing device ( 47 ) for securing the connecting sleeve ( 30 ) to the bushing part ( 23 ) in the longitudinal direction (L).

15. The explosion-proof assembly of claim 14 in which said securing device ( 47 ) is a form-fitting about the inner body ( 31 ) such that at least at one point outside the bushing opening ( 24 ) the inner body ( 31 ) has a dimension in the radial direction (R) that is greater than the dimension of the bushing opening ( 24 ) in the radial direction (R).

16. The explosion-proof assembly of claim 15 in which the securing device ( 47 ), at least in part, is an integral part of the bushing part ( 23 ).

17. A method for producing an explosion-proof assembly ( 20 ) having the following steps:
providing a bushing part ( 23 ) having a bushing opening ( 24 ) with a bushing surface ( 25 ),
providing an inner body ( 31 ) made of a deformable material having at least one conductor channel ( 32 ) extending through the inner body ( 31 ) in a longitudinal direction (L), and a connecting sleeve ( 30 ) made of a plastically deformable material which surrounds the inner body ( 31 ) in a circumferential direction (U) about the longitudinal direction (L),
guiding an electrical and/or optical conductor leap ( 22 ) of at least one conductor ( 21 ) through its own associated conductor channel ( 32 ) in the inner body ( 31 ),
plastically deforming the connecting sleeve ( 30 ) in a connecting portion ( 33 ) such that at least a portion of an outer surface
( 34 ) of the plastically deformed connecting portion ( 33 ) is plastically deformed to form a first delimiting surface ( 35 ), and
arranging the connecting portion ( 33 ) of the connecting sleeve ( 30 ) in the bushing opening ( 24 ) so that the first delimiting surface ( 35 ) of the connecting portion ( 33 ) forms a flameproof [Ex] gap ( 37 ) with a second delimiting surface ( 36 ) defined by the bushing surface ( 34 ) configured to prevent any flame transmission through the [Ex] gap ( 37 ).

Assignees

• Stahl R Schaltgeraete Gmbh
• R Stahl Schaltgerate Gmbh

Inventors

• Semrau Holger
• Kutsch Maxim

Classifications

• H02G3/081

  Bases, casings or covers · CPC title

• H01H9/042

  Explosion-proof cases · CPC title

• H02G3/0625

  with means for preventing disengagement of conductors · CPC title

• H02G15/013

  Sealing means for cable inlets (inlets for cables filled with, or surrounded by, gas or oil H02G15/32) · CPC title

• H02G3/22

  Installations of cables or lines through walls, floors or ceilings, e.g. into buildings · CPC title