WO2019110145A1

WO2019110145A1 - Explosion-protected housing

Info

Publication number: WO2019110145A1
Application number: PCT/EP2018/025305
Authority: WO
Inventors: Reiner Naumann; Gerhard Schwarz
Original assignee: Eaton Intelligent Power Limited
Priority date: 2017-12-05
Filing date: 2018-11-30
Publication date: 2019-06-13
Also published as: DE102017128816A1

Abstract

An explosion-protected housing (1), in particular for a lamp, having a substantially pot-shaped housing lower part (2) and a housing cover (3). So as to improve such a housing in such a way that the corresponding, more penetration-proof gaps may be manufactured simply and with simple means, and at the same time connecting of a housing cover and housing lower part or closure of the housing opening by the housing cover is possible without great effort by every user in a simple manner, the housing lower part (2) has an edge flange (5) surrounding a housing opening (4) and the housing cover (3) has at least one support flange (6) extending radially from a substantially lower cover edge (7), wherein at least one insert -and- turn closure device (8) is configured between the edge flange (5) and the support flange (6).

Description

Explosion-protected housing

The invention relates to an explosion-protected housing, in particular for a lamp, with a substantially pot-shaped housing lower part and a housing cover, wherein the housing lower part has an edge flange enclosing a housing opening and the housing cover has at least one abutment flange project ing radially from a substantially lower cover edge.

Such explosion-protected housings are familiar from the prior art. In them, as a rule, the housing cover and the housing lower part are screwed or glued to one another along the edge flange and cover edge. If they are screwed, either a row of screws is used or the housing cover is screwed on or in the housing lower part. Here it is likewise familiar from the prior art for example that a large and only single-start thread is used. By these corresponding connections of the edge flange and cover edge, a corresponding gap is formed which is penetration-proof and allows the use of the explosion- protected housing in explosion-endangered regions. The corresponding gaps here are formed be tween cylindrical or even flat parts of the edge flange or cover edge. With these types of fastenings of housing lower parts and housing covers, it is disadvantageous that the manufacturing tolerances for the required gaps are relatively small and likewise that a row of additional work steps are necessary in order to allow the corresponding fastening between the hous ing lower part and the housing cover or closure of the housing opening by the housing cover. If the two parts are glued together, as a rule the explosion-protected housing cannot be opened using the housing cover in order to allow repairs or maintenance of the operating equipment arranged within the housing.

A preferred exemplary embodiment of such a housing is used in particular for a lamp.

It is therefore the object of this invention to improve an explosion-protected housing of the type indicated above in such a way that the corresponding penetration-proof gaps may be produced simp- ly and with simple means and at the same time that a connection of the housing cover and housing lower part or closure of the housing opening by the housing cover is also possible without great ef fort by every user in a simple manner.

This object is achieved by the features of patent claim 1. In particular the invention is characterized by the fact that at least one insert-and-turn closure device is formed between an edge flange and a support flange. That is to say, the support flange and cover edge are inserted in one another and subsequently turned in such a way that penetration-proof gaps are formed between them for an explosion-protected housing.

In order to be able to implement insertion and turning in a simple manner, it is helpful where appli- cable if the edge flange has at least one in particular circumferential longitudinal slot and at least one transverse slot connected to the longitudinal slot, wherein the support flange has at least one clamp ing hand, which can be inserted in the transverse slot in an insertion direction and then may be turned along the longitudinal slot in a rotary direction. Here as a rule the edge flange and the abut ment flange, when the clamping head is inserted in the transverse slot, abut one another and are pressed against one another by the subsequent turning along the longitudinal slot. This produces a penetration-proof gap between these parts, wherein no further screwing, use of screws, or gluing is necessary.

It is conceivable that the transverse slot runs obliquely in the direction of the longitudinal slot so that as soon as the clamping head is inserted in the transverse slot, some rotation of the housing cover relative to the housing lower part occurs. After reaching the longitudinal slot, by further turning of the housing cover in the rotary direction, this rotation can then be continued. In a simple exemplary embodiment, the insertion direction can be vertical to the rotary direction. In this way, the clamping head of the abutment flange is inserted substantially vertically in the transverse slot until it is ar ranged in the longitudinal slot. At that point a corresponding turning in the rotary direction can take place.

In order to be able to simply form the longitudinal slot, it can be radially open toward the housing lower part and can have a slot base wall, a slot side wall, and a slot cover wall. The slot base wall extends substantially radially to the outside of the housing opening. Then the slot side wall extends from the slot base wall upward in the direction of the housing cover and is then connected to the slot cover wall, which again extends substantially radially inward in the direction of the housing opening or the housing cover.

A simple arrangement of the transverse slot can be seen when it is optionally formed in the slot cover wall and is open in the opposite direction from the slot side wall, i.e. radially inward in the direction of the housing cover. An easy-to-use housing cover with reliable connection in the housing lower part may be produced for example when two, three, four or more transverse slots and a corresponding number of clamping heads are formed. Preferably when two transverse slots and clamping heads are used, they are ar ranged diametrically opposite one another. For three, four, or more transverse slots and the corre- sponding clamping heads, they can be arranged in the circumferential direction of the housing cover or the housing lower part with an equal separation between them. This is not necessary, of course, as for example different separations in the circumferential direction are also conceivable.

By means of the transverse slots with longitudinal slot and clamping heads, for example the insert - and-turn closure device can be formed as a bayonet closure device. Thus the support flange of the housing cover extends radially to the outside and can be formed by the flange base which substantially extends radially to the outside. The support flange may also comprise other parts besides the flange base. For a flange base as part of a support flange or as a support flange, furthermore, it has proven to be advantageous when the clamping head is separated from it laterally and radially to the outside. In the simplest case, the clamping head is arranged in a radial extension of the flange base.

For a connection of the housing cover and housing lower part, and with the use of the insert-and- turn closure device, in order to determine a required gap length and gap width in a simple manner, a fastening end position of the housing cover can be established by a stop on the housing lower part. That is to say, turning of the housing relative to the housing lower part occurs as far as this fastening end position, in which then the corresponding gaps between the housing cover and housing lower part are established in gap length and gap width. In this way a gap is always created with reproduci ble gap parameters in order to provide a penetration-proof gap for the explosion-protected housing.

In this regard it can furthermore prove advantageous when optionally the stop is formed as an end position switch. This means that upon assumption of the fastening end position, the end position switch is actuated such that the operating means in the explosion-protected housing is ready for operation. Accordingly, upon release of the contact with the end position switch, actuation of the operating means such as lighting equipment is prevented.

In this regard, it is possible that the end position switch is configured as protection type Ex-i, meaning intrinsic safety, or Ex-d, meaning flameproof enclosure. For contacting the stop or the end position switch, it can be conceivable in this regard that the cover ing has at least one end stop projecting from the flange base in the direction of the housing lower part and in the fastening end position contacts the stop or the end position switch. Such an end stop can for example, when the housing cover is mounted on the housing opening, extend along a wall of the housing lower part and, upon turning of the housing cover relative to the housing lower part, can be moved along the wall so that when it reaches the fastening end position it contacts the stop or the end position switch.

It is likewise conceivable that the stop is configured in addition to the end position switch and, for example, is arranged in the longitudinal slot. In this way as well, a fastening end position can be es- tablished in which for example a clamping head contacts the stop. The corresponding end stop can be additionally configured for contacting the end position switch.

Likewise conceivable is not only a stop for establishing the fastening end position, but optionally sev eral of them which for example contact the corresponding clamping heads.

So as to be able to simply establish an initial position for mounting the housing cover on the housing lower part, in particular as regards this fastening end position, it is conceivable that the clamping heads and/or transverse slots are not all configured identically. For example, one transverse slot can have a smaller or greater length in comparison with the other transverse slots so that a specific clamping head must be inserted in this transverse slot so as to establish the specific insertion position of the housing cover relative to the housing lower part. Here it is likewise possible that the clamping head likewise is accordingly configured shorter or longer.

So as to prevent independent opening of the housing relative to the housing lower part as well as inadvertent opening, it is optionally advantageous if an effective and detachable rotation fixation device is configured between the housing lower part and the housing cover, in particular on the housing lower part. By means of this rotation fixation device, independent turning of the housing cover relative to the housing lower part without external intervention is prevented. This likewise applies to inadvertent turning of the housing relative to the housing lower part by a user. The rotation fixation device first has to be accordingly loosened so that reverse rotation of the housing cover counter to the rotational redirection is possible. One exemplary embodiment of the rotation fixation device is a latching device in which the rotation fixation device has at least one detachable latch that can be latched in the fastening end position especially with a clamping head. That means that when the housing cover is turned as far as its fas tening end position, this latch will engage the clamping head for example contrary to the rotational direction and will latch behind it so that the fastening end position is fixed. Only when the latch is released is it possible to turn the housing cover counter to the rotational direction and, when the clamping heads are arranged to fit the corresponding transverse slots, to raise it from the housing lower part.

One such detachable latch can be implemented differently, wherein an exemplary embodiment is possible in which the latch is configured as a spring steel strip which in particular projects from the slot side wall in the rotational direction obliquely inward. Consequently, if the clamping head moves past the spring steel strip, because of its elasticity the latter is pressed in the direction of the slot side wall and after passage of the clamping head springs back radially inward and prevents reverse rota tion of the clamping head. Only when the spring steel strip is pushed back in the direction of the slot side wall can the clamping head be rotated back past the latter counter to the rotational direction.

So as to allow simple access to the spring steel strip or to the latch, in one exemplary embodiment the slot cover wall can have an access opening in the region of the latch or the spring steel strip. Through this access opening for example a screwdriver or the like can be inserted with which the latch can be pressed out of its latched position.

If the edge flange and the support flange are configured with just a small radial width, it is likewise possible that a penetration-proof gap with the corresponding parameters such as gap length and gap width can be achieved if, on the slot base wall and on a lower side of the support flange, interlocking and in particular circular grooves are configured. These are configured complimentarily with respect to one another so that the grooves reliably engage one another and in particular also allow turning of the housing cover relative to the housing lower part in the rotational direction or even counter to the rotational direction. As a rule, two, three, four or more further circular grooves are sufficient in order to at least additionally determine the penetration-proof gap between the grooves.

Different materials are conceivable for the housing, wherein for example the housing can be made of plastic, glass, or metallic materials. If the housing cover is used for a lamp, for a display device or the like, it can further prove advantageous if at least the housing cover is transparent or translucent. In the following, an advantageous exemplary embodiment of the invention is explained in more de tail with reference to the figures included in the drawing.

Wherein:

Figure 1 shows a perspective view obliquely forward of an explosion-protected housing according to the invention with a housing lower part and the housing cover in a separate arrange ment;

Figure 2 shows the explosion-protected housing according to figure 1 in an assembled arrange ment and in particular with the housing cover in the fastening end position;

Figure 3 shows a vertical section through the explosion-protected housing according to figure 2 and

Figure 4 shows an enlarged depiction of a lower region of the housing cover.

Figure 1 shows an exemplary embodiment according to the invention of an explosion-protected housing 1 which has a housing lower part 2 and a housing 3. The housing lower part 2 is substantially pot-shaped with a closed lower side and an opposite housing opening 4. This is enclosed by an edge flange 5 which substantially projects radially outward.

The housing cover 3 is made of a transparent material and has a support flange 6 which surrounds a lower cover edge 7 of the housing cover 3 and optionally contains it.

The edge flange 5 has transverse slots 10 at several points which extend in the circumferential direc- tion of the edge flange 5 and run as far as the longitudinal slot 9 in the edge flange 5. The longitudi nal slot 9 - see also figure 3 - extends in the circumferential direction around the corresponding housing opening 4 of the housing lower part 2. The transverse slots 10 are equally separated in the circumferential direction and can have the same length and the same shape.

In the interior of the housing lower part 2, a stop 20 is visible which in particular is configured as an end position switch 21. It is likewise possible that such a stop 20 is arranged in the region of the lon gitudinal slot 9, wherein the end position switch 21 is additionally arranged. The cover edge 7 of the housing cover 3 has clamping heads 11 at points which correspond to the transverse slots 10 and extend radially outward from the support flange 6. The fastening heads 11 can be part of the support flange 6. In the depicted exemplary embodiment, the clamping heads 11 extend partially along the circumferential direction of the housing cover 3 and have substantially the same length and the same shape.

The clamping heads 11 along with the transverse slots 10 and longitudinal slot 9 form an insert-and- turn closure device 8.

Figure 1 shows the housing cover and housing lower part separate from one another. Accordingly, in figure 2, the housing cover and the housing lower part are connected to one another, and through the insert-and-turn closure device with the corresponding gaps between in particular the edge flange and abutment flange or the clamping head and longitudinal slot, an explosion-protected housing is formed, wherein the corresponding gaps are penetration-proof.

In order to mount the housing cover 3 on the housing lower part 2 for closing the housing opening 43, the housing cover 3 in insertion direction 12 - see figure 2 - is brought close to the housing lower part 2 and inserted with the clamping heads 11 into the transverse slots 10. The clamping heads 11 are useable due to the transverse slots 10 until attainment of the longitudinal slot 9, and subsequent ly turning of the housing cover relative to the housing lower part can take place in the rotational di rection 13.

The longitudinal slot 9 - see figure 3 - is configured with a slot base wall 14, a slot side wall 15, and a slot cover wall 16. The slot base wall 14 extends substantially radially outward and at its end the slot side wall 15 projects upward. From the slot side wall 15, the slot cover wall 16 then extends radially inward, and substantially parallel to the slot base wall 14. The longitudinal slot 9 is formed between these walls.

In figure 2, the housing cover 3 and housing lower part 2 are connected to one another and the hous- ing cover 3 is arranged in its fastening end position 19. This applies analogously to figure 3, in which the explosion-protected housing 1 is shown according to figure 2 in a vertical section. The corre sponding transverse slots, the longitudinal slot, and the clamping heads 11 together form a bayonet closure device 17 as the insert-and-turn closure device 8. In particular, more than two corresponding transverse slots and clamping heads 10 or 11 are provided. The support flange 6 has a flange base 18 or is formed by one, wherein the flange base 18 - see fig ure 3 - may be turned in the rotational direction 13 in the longitudinal slot 9. The flange base can also partly extend into the housing lower part 2 and in particular has an end stop 22 projecting in the direction of the housing lower part 2. When the housing cover 3 is arranged in the fastening end po sition 19 - see figure 2 and 3 - this rests against a stop 20, which in the depicted exemplary embodi ment is configured as an end position switch 21. This has the ignition protection type Ex-i or Ex-d. If the end stop 22 rests against the stop 20 or the end position switch 21, a corresponding circuit is closed and the operating means in the explosion-protected housing are ready for operation. In the fastening end position 19, the housing cover 3 is connected to the housing lower part 2 via a penetra tion-proof gap, so that overall an explosion-protected housing 1 results.

So as to prevent independent unscrewing from the fastening end position 19, the explosion- protected housing 1 has a rotation fixing device 23 - see also figure 4 - which is formed by a latch 24 for example in the form of a spring steel strip 25. This spring steel strip projects for example in the rotational direction 13 according to figure 4 obliquely inward in the longitudinal slot 9, so that a clamping head 11 may be rotated past this spring steel strip 25, but may be rotated back without external intervention. So as to move the spring steel strip 25 from its latched position, a tool may be inserted into an access opening 26 - see figure 2 - and the spring steel strip 25 resting against the slot side wall 15 for example can be pressed. In this arrangement of the spring steel strip 25, reverse rotation of the clamping heads 11 counter to the rotational direction 13 according to figure 4 is pos sible.

In order to be able to be able to form the corresponding penetration-proof gaps with only small di mensions of the support flange and cover edge, grooves 28 are provided on the lower side 27 of the support flange itself or of the flange base 18 and accordingly of the slot base wall 14 of the longitudi nal slot 9. These have a triangular cross section, for example, and are engaged with one another. The corresponding gap extends between these grooves and the other parts of the slot base wall 14 and flange base 18.

Between the flange base 18 and, for example, the slot base wall 14, in particular a sealing ring can be arranged. The sealing ring can also be arranged at another point between the housing lower part and housing cover, such in the interior of the housing lower part, for example, and between the corre sponding housing wall and a flange of the cover edge 7 projecting into the housing wall. Altogether, by means of the insert-and-turn closure device, a simple capability for connecting the housing lower part and housing cover and thus for closing the housing opening is provided. This clo sure device is simply configured and actuable. At the same time, a penetration-proof gap is formed - see also in this regard the interlocking grooves. The housing materials may be plastic materials, metallic materials, as well as glass. In particular the housing cover, when a lighting means is used as the operating means, may be produced from a transparent or translucent material.

Claims

1. An explosion-protected housing (1), in particular for a lamp, having a substantially pot-shaped housing lower part (2) and a housing cover (3), wherein the housing lower part (2) has an edge flange (5) surrounding a housing opening (4) and the housing cover (3) has at least one support flange (6) projecting radially from a substantially lower cover edge (7), and at least one insert- and-turn closure device (8) is configured between the edge flange (5) and support flange (6).

2. The explosion-protected housing according to claim 1, characterized in that the edge flange (5) has at least one in particular surrounding longitudinal slot (9) and at least one transverse slot (10) connected to the longitudinal slot (9), wherein the support flange (8) has at least one clamping head (11), which can be inserted in the transverse slot (10) in an insertion direction (12), and may subsequently be turned along the longitudinal slot (9) in a rotational direction (13).

3. The explosion-protected housing according to claim 1 or 2, characterized in that the insertion direction (12) is vertical to the rotational direction (13).

4. The explosion-protected housing according to any one of the preceding claims, characterized in that the longitudinal slot (9) is open radially inward to the housing lower part (12) and has a slot base wall (14), a slot side wall (15), and a slot cover wall (16), wherein in particular the transverse slot (10) is configured in the slot cover wall (16) and is open in the direction counter to the slot side wall (15).

5. The explosion-protected housing according to any one of the preceding claims, characterized in that two, three, four, or more transverse slots (10) and a corresponding number of clamping heads (11) are configured.

6. The explosion-protected housing according to any one of the preceding claims, characterized in that the insert-and-turn closure device (8) is a bayonet closure device (17).

7. The explosion-protected housing according to any one of the preceding claims, characterized in that the support flange (6) has a flange base (18) extending radially outward, from which the clamping head (11) projects laterally radially outward.

8. The explosion-protected housing according to any one of the preceding claims, characterized in that a fastening end position (19) of the housing cover (3) is configured by a stop (20) on the housing lower part (2) and/or the stop (20) is configured as an end position switch (21).

9. The explosion-protected housing according to any one of the preceding claims, characterized in that the housing cover (3) has at least one end stop (22) projecting from the flange base (18) in the direction of the housing lower part (2), and in the fastening end position (19) of the housing cover (3) contacts the stop (20) or the end position switch (21).

10. The explosion-protected housing according to any one of the preceding claims, characterized in that between the housing lower part (2) and housing cover (3) an effective and releasable rota- tion fixing device (23) in the fastening end position (19) is configured, in particular on the housing lower part (2) and/or the rotation fixing device (23) has at least one releasable latch (24), which may be latched in the fastening end position (19) in particular with a clamping head (11).

11. The explosion-protected housing according to any one of the preceding claims, characterized in that the latch (24) is configured as a spring steel strip (25), which in particular projects laterally inwardly from the slot side wall (15) in the rotational direction (13).

12. The explosion-protected housing according to any one of the preceding claims, characterized in that the slot cover wall (16) has an access opening (26) in the region of the latch (24).

13. The explosion-protected housing according to any one of the preceding claims, characterized in that the end position switch (21) is formed in the protection type Ex-i (intrinsically safe) or Ex-d (flameproof enclosure).

14. The explosion-protected housing according to any one of the preceding claims, characterized in that on the slot base wall (14) and on a lower side (27) of the support flange (6), interlocking and in particular circular grooves (28) are configured.

15. The explosion-protected housing according to any one of the preceding claims, characterized in that the housing (1) is made of plastic, glass, or a metallic material, and at least the housing cover

(3) is transparent or translucent.