EP0141099A2 - Warning device - Google Patents

Abstract

The surveillance signal apparatus is preferably provided a signal lamp, as an illuminated switch or as an illuminated key. It comprises a casing with electrical and electronic connections and with an apparatus heat disengageably disposed at the casing. The apparatus head comprises a signal part provided with electric voltage and preferably an illuminating element. A voltage limiter and a current limiter are disposed in an explosion-proof and pressure tight encapsulated space of the casing and they are electrically predisposed to the signal part in the apparatus head via a feed part. The apparatus head with the signal part and the feed part are formed by the output of the voltage limiter and by the output of the current limiter as an explosion protection self safety unit.

Description

The invention relates to a signaling device with the features of the preamble of claim 1.

In known signaling devices of this type, it is disadvantageous that, when used in potentially explosive atmospheres or the like, corresponding pressure-resistant encapsulations must also be provided for the device head and the assembly on the front panel of a control cabinet or other device can only be carried out with a special tool in order to unintentionally loosen it prevent endangered space.

The object of the invention is to design a signaling device with the features of the preamble in such a way that a much simpler device head area with high intrinsic safety against an explosion risk is achieved, the device head being able to be assembled and disassembled or replaced or replaced at any time in a potentially explosive area without special tools,

This object is achieved according to the invention by the characterizing features of claim 1.

• FIG, 1 eine geschnittene Seitenansicht eines erfindungsgemäßen Gerätekopfes,
• FIC, 2 eine geschnittene Seitenansicht eines erfindungsgemäßen Gehäuses für einen Gerätekopf ähnlich der FIG. 1 und
• FIG. 3 eine geschnittene Seitenansicht eines erfindungsgemäßen Meldegerätes mit am Gehäuse gekuppeltem Gerätekopf.

Preferred refinements and developments as well as further advantages and essential details of the invention can be found in the features of the subclaims, the following description and the drawing, which shows preferred embodiments as an example in a schematic representation. It represent;

• 1 shows a sectional side view of a device head according to the invention,
• FIC, 2 is a sectional side view of a housing according to the invention for a device head similar to FIG. 1 and
• FIG. 3 shows a sectional side view of a signaling device according to the invention with the device head coupled to the housing.

The in the FIG. 1 shown device head 1 is releasably attached to the front wall 2 of a cabinet or the like without special tools. The device head has an insert body 3 which penetrates a hole 4 in the wall 2. The insert body has a shoulder 5, which is supported on the outside 6 of the wall 2 with the interposition of a rubber-elastic seal 7. A fastening nut 9, which is mounted on a threaded part 10 of the insert body 3, is screwed against the inside 8 of the wall 2, the outside of the device head 1 also has a front ring 11, which on a thread 12 formed on the shoulder 5 of the insert body 3 in the direction is screwed against the outside 6 of the wall 2 and thereby overlaps a translucent cover 13 on its circumference and against defines the insert body 3 with the interposition of an elastic sealing washer 14. The translucent cover 13 covers a lens 15, for example in the colors red, green, blue, yellow, etc., which in turn covers a signaling part designed here as a lighting element 16.

The luminous element 16 is arranged in the region of a reflector 17, which in the present exemplary embodiment is preferably made of plastic and whose reflector surface is white. It may also be expedient to provide the reflector 17 with a metallic reflection layer, which can be produced, for example, by metallization in a high vacuum (metal vapor deposition). The light-emitting element (16) is here particularly advantageously designed as an optoelectronic CERLED light-emitting part, in that preferably six to eight CERLED components 19 are arranged on a carrier plate 18, it also being within the scope of the invention, fewer, for example three or, on the carrier plate to arrange four, or even more, for example fifteen, OERLED components 19. The CERLED components essentially consist of a small ceramic carrier on which an LED chip is attached. The ceramic carrier of the CERLED component 19 can be provided with a conductive coating on four sides (surface, underside and both end faces). The ceramic carrier, the dimensions of which can be, for example, about 3.2 by 1.27 by 0.6 millimeters, is bonded on the top with an LED chip. A crystal-clear plastic lens with a height of approximately 0.6 millimeters is arranged above the LED chip, which comprehensively protects the LED chip on the top of the ceramic carrier. This building block or CERLED Component 19 can be attached to corresponding conductor tracks with its conductive underside and / or with the conductive end faces on the carrier plate 18. It is also possible to apply individual lighting parts directly to a larger ceramic printed circuit board, so that a CERLED lighting unit is thus formed. The lighting element 16 can also have one or more glow lamps, incandescent lamps, filaments, Leuohtdioden and the like. The entire lighting element 16 is embedded in the reflector 17 in a casting part 20 which is translucent, so that the light emitted by the lighting element 16 through the casting part 20, the lens 15 and the cover 13 can radiate outward.

The reflector 17 is associated with a luminaire housing 21, the base wall 22 of which is penetrated by a contact bolt 23 which projects out of the insert body 3 at the bottom. The contact pin 23 has an inner axial conductor 24, from which a connecting conductor 25 is guided to the Leuoht element 16. The axial conductor 24 is located in a tubular insulating sleeve 26 which is somewhat shorter than the axial conductor 24, so that an upper connection end for the connecting conductor 25 and a lower contact part protrude on the opposite end faces of the insulating sleeve 26. The insulating sleeve 26 is in turn surrounded by a metallic sleeve conductor 27, which is somewhat shorter than the insulating sleeve 26, so that the latter protrudes from the sleeve conductor 27 on both ends. The sleeve conductor 27 has a collar 28 which rests in the luminaire housing 21 in a supportive manner on the inner surface of the base wall 22. A further connecting conductor 29 is preferably on the collar 28 by means of soldering Binding connected, which is also led to the lighting element 16.

The device head 1 is associated with a housing 30, as is essentially shown in FIG. 2 and 3 is shown. The device head 1 is releasably attached to the housing 30 or detachably coupled to the housing 30, so that a complete signaling device 31 is provided in the coupling state. The contact pin 23 of the device head 1 is located in a pipe socket 32 of the housing 30. The pipe socket 32 and the contact pin 23 inserted into it together form a supply part 33 for the voltage supply to the signaling part or lighting element 16,

The pipe socket 32 has an insertion bevel 34 for the contact bolt 23 on the free inner edge area facing the device head 1. At the other end of the pipe socket 32, an end flange 35 is formed which is supported on an inner surface of the housing 30. In addition, in the region of the end flange 35, a closure end 36 is arranged, which closes the pipe socket 32 at its lower end region. The spanking cover 36 has on its side facing the interior of the pipe socket 32 a trough 37 into which the free end of the contact bolt 23 or the axial conductor 24 protruding from the device head 1 can penetrate.

On the inner surface of the pipe socket 32, two electrically conductive base webs 38, 38 ′ are arranged, which are diametrically opposite one another and extend in the longitudinal direction of the pipe socket 32. The base webs 38, 38 'are overlapped at their free ends pointing in the direction of the housing head 1 by inwardly projecting wall parts 39 of the tube mount 32, thereby ensuring that the base webs 38, 381 are firmly held in the tube mount 32. The base web 38 is somewhat shorter than the opposite base web 38 '. A contact spring 40 formed integrally with the material is located on the base web 38, while a further contact spring 40 I is formed on the base web 38 '. The contact springs 40,40 'are directed obliquely inwards in the direction towards the _A CHS center and the closure cover 36 of the pipe socket 32, so that the contact pin can be of the device head 1 without obstruction inserted into the pipe socket 32 23 and a permanent bending of the contact springs 40, 40 'is avoided. The contact springs 40, 40 'have corresponding contact tips at their free ends, the contact tip of the contact spring 40 resting on the free end region of the axial conductor 24 and the contact tip of the other contact spring 40' resting on the outer surface of the sleeve conductor 27. Conductor connections 41, 41 'are formed on the base webs 38, 38', which in the present exemplary embodiment are guided outwards at right angles in the area of the closure cover 36 in opposite directions out of the pipe socket 32. Connections 42, 42 'which lead to an electronic circuit board 43 are connected to the conductor connections 41, 41'.

The pipe socket 32 is surrounded on its outer circumference by a Druokstück 44, which is axially displaceably guided on the pipe socket 32 in the longitudinal direction. The pressure piece 44 is spring-loaded by a helical compression spring 45, which the pipe socket 32nd also surrounds, is supported at one end on the housing 30 and engages with its other end in an annular groove of the pressure piece 44 and presses the latter upwards in the direction of the device head 1. At the top, the housing 30 has an approximately hood-shaped holding frame 46, which is connected to the housing 30 by means of a releasable locking or clip lock. On the upper side of the holding frame 46 facing the device head 1, a spring clip 47 is provided, which connects the releasable coupling between causes the device head 1 and the housing 30,

An explosion-proof, pressure-resistant space 48 is located under the pipe socket 32, approximately in the central region of the housing 30. At least one voltage limiter and a current limiter (not visible here) are stored in this pressure-resistant space 48, so that the voltage supplied to the lighting element 16 in the device head 1 corresponds to the explosion Intrinsic safety (EN 50020) is limited to a maximum of 18 V and the maximum permissible current flowing here is limited to a maximum of 30 mA. This provides a high level of explosion protection with simple means, without the device head 1 being subject to a special encapsulation and special fastening, but instead being able to be safely disconnected from the housing at any time without the voltage having to be switched off and other safety precautions being taken. The device head 1 with the signaling part 16 and the feed part 33 is thus designed, starting from the outputs of the upstream voltage and current limiters in the pressure-resistant space 48, according to the invention as an explosion protection intrinsic safety unit 49.

The voltage limiter in the pressure-resistant space 48 of the housing 30 can advantageously be formed from two Zener diodes connected in parallel, while the current limiter can consist of an appropriately dimensioned resistor. Instead of the resistor, an electronic current limiter can also be provided,

The voltage limiter and the current limiter are expediently arranged on the electronic circuit board 43 in the pressure-resistant space 48. On this electronic circuit board 43, a transformer 50 can also be arranged in the pressure-proof space 48, which, for example, transforms a higher voltage supplied to the signaling device 31 down to the operating voltage supplied to the signaling part 16. For this purpose, a rectifier 51 can be arranged on the electronic circuit board 43, via which an AC voltage introduced is rectified for the operation of the lighting element 16. In addition, it can be expedient to provide an electronic fuse 52 on the electronic circuit board 43, which can preferably be designed as a fuse,

For the pressure-tight encapsulation of the prescribed parts in the housing 30, the voltage limiter, the current limiter, the electronic circuit board 43, the transformer 50, the rectifier 51, the electrical fuse 52 and the connections 42, 42 ^{1 are} enclosed by a casting resin 53, so that a safe one Potting is completed against the risk of explosion. An epoxy resin or a polyurethane can expediently be provided as the casting resin. In addition, it may be expedient to set the casting resin 53 in this way or to make such different offs to choose guides that the parts stored in the pressure-resistant space 48, such as voltage limiter, current limiter, circuit board 43, transformer 50, rectifier 51 and electrical fuse 52, are directly surrounded by an elastic, resilient wall area of the casting resin 53 or the like and that they are then elastic to these Wall area the actual solid cast resin potting is formed. The elastic wall area ensures high usability even under extreme loads, such as vibrations and fluctuating temperature intervals, so that there is a high degree of long-term functionality.

In the present exemplary embodiment, a latching device 54 is arranged above the pressure-free space 48 to the right of the pipe socket 32, which has two switching locks for a shift lever by means of a corresponding link guide a stroke compensation part 55 is actuated, which has a pot bolt 56 in which a helical Ausgleiohafeder 57 is mounted. The stroke compensation part 55 is covered at the top by the holding frame 46. Under the base wall 58 of the pot bolt 56 there is a plunger 59 which penetrates the wall 6 _{1 in an} axially displaceable manner in a cylindrical, explosion-proof gap bushing 60 and projects into an explosion-proof, pressure-tightly encapsulated chamber 62. In the illustration shown, this chamber 62 is located to the right of the pressure-proof space 48 or next to the electrical fuse 52. In the pressure-proof chamber 62 there is a microswitch 63 stored, against whose switching pin 64, the plunger 59 acts. For certain switching functions, it may be expedient to arrange two microswitches in the chamber 62. The pressure-resistant chamber 62, like the pressure-resistant chamber 48, is encapsulated with explosion-proof casting resin 53,

In the in the FIG. 2 embodiment shown, the end of a hose line 65 is cast in the resin 53 in the area under the pressure-resistant space 48. The hose line 65 has individual conductors 66 which are associated with the corresponding electrical functional parts in the housing 30. There is also the possibility of pouring even one or more individual lines, which are therefore not combined to form a hose line, into the housing 30 at the bottom. To couple 2 shown housing 30 with the device head 1 of FIG. 1 shown above, but this is not entirely expedient since the device head according to FIG. 1 is designed as a pure signal lamp, so that no microswitch, no lifting component and no locking device are required. In the free spaces, in particular in the pressure-resistant chamber 62, a further electrical B component can advantageously be used for a further function. It may also be advantageous to supply the supplied voltage at the correct level (18 V) so that the transformer 50 in the pressure-resistant space 48 can be saved. In this case, the resulting free space can be used advantageously for other parts, such as electronic components (control elements, relays, microprocessors, etc.). As a result, are more appropriate Possible applications for the reporting device 31 according to the invention.

In the in the FIG. 3, in contrast to the housing 30 of FIG. 2, the housing 30 ¹ line terminals 67, to which the conductor parts 68 are associated, which are embedded in the casting resin 53, so here no hose line is provided, but the housing 30 'can be connected to busbars or the like.

In the in the FIG. In the exemplary embodiment shown in FIG. 3, the signaling device 31 according to the invention also has a device head 1 ′ which is designed as an explosion-protected illuminated pushbutton, switching light unit or light switch attachment. For this purpose, the lamp housing 21, in which the lighting element 16 is mounted, is designed somewhat differently. In addition, the lens 15 'is surrounded by a rubber-elastic sleeve 69 and mounted on a push-button 7 _{is 0,} the 30'im in the direction against the housing device head 1' is axially displaceable. A pressure sleeve ⁷ 1 is assigned to the push button 70 in the insert body 3. This pressure sleeve 71 has a helical spring 72 and acts upon actuation of the push button 70 against the pressure piece 40 surrounding the pipe socket 32, through which the switching stroke is transmitted via the latching device 54, the stroke compensation part 55 and the plunger 59 to the microswitch 63, respectively. It is therefore realized in this embodiment, a Druok switch signaling device, which has a light element 16 in the push button 70 for display, the feed part to the device head 1 and this itself being fully explosion-proof, so that no additional Safety precautions are necessary. Specifically, the device head 1 'with the lighting element 16 and the pushbutton 70 is designed in particular as an explosion-protected switching light unit, which, independently of the proposed invention, already has the particular advantage that a switch or button and a light unit are integrated into a single structural unit are explosion-proof. Such an explosion protection switching light unit is not yet known.

To avoid an impermissibly high excess temperature on the outside of the housing 30, 30 ', it can be expedient to arrange a temperature fuse in the pressure-tightly encapsulated space 48. This ensures that a maximum outside temperature of, for example, 80 ° C is never exceeded.

Another essential feature of the invention is that in the device head 1, 1 'different colored and different types of Leuoht advertisements can be replaced and replaced without special safety precautions, so that an optimal functional display can always be achieved according to the respective requirements.

Claims (19)

1. signaling device (31), in particular signal lamp, illuminated pushbutton, light switch and the like, with a housing (30, 30 ') having electrical connections and a device head (1, 1') detachably fastened to it, which has a signaling part (16 ), characterized in that a voltage limiter and a current limiter are arranged in an explosion-proof encapsulated space (48) of the housing (30, 30 ') and connected upstream of the signaling part (16) in the device head (1, 1') via a feed part (33) and that the device head (1, 1 ') with the signaling part (16) and the feed part (33) from the output of the voltage limiter and the current limiter is designed as an explosion protection intrinsic safety unit (49). 2. Signaling device according to the preceding claim, characterized in that the signaling part (16) in the device head (1, 1 ') has at least one Zener diode connected as a voltage limiter and an electrical resistor as an (electronic) current limiter and in the space (48) of the housing (30, 30 ') are arranged. 3. Signaling device according to one of the preceding claims, characterized in that the voltage limiter and the current limiter and a rectifier (51) connected upstream of the signaling part (16) and a transformer (50) upstream of the voltage limiter and the current limiter and an electrical fuse (52) on one Printed circuit board (43) in the space (48) of the housing (30, 30 ') and that between the feed part (33) of the explosion protection intrinsic safety unit (49) and the printed circuit board (43) in the space (48) of the housing (30, 30 ') connections (42, 42') are arranged. 4. Signaling device according to one of the preceding claims, characterized in that the at least the voltage limiter and the current limiter containing space (48) of the housing (30,30 ') is enclosed by a casting resin (53) and that embedded in the casting resin (53) Parts, such as voltage limiters, current limiters, transformers (50), are preferably enclosed by an elastic wall area of the casting resin (53). 5. Signaling device according to one of the preceding claims, characterized in that the housing (30, 30 ') in addition to the space containing the voltage limiter and the current limiter (48) has line terminals (67) with conductor parts (68) enclosed in the casting resin (53). 6. Signaling device according to one of the preceding claims, characterized in that on an underside of the housing (30, 30 ') an electrical line (65) opening into the latter is arranged with at least one individual conductor (66) and is enclosed in the casting resin (53). 7. Signaling device according to one of the preceding claims, characterized in that the feed part (33) of the explosion protection intrinsic safety unit (49) has a pipe socket (32) arranged on the housing (30, 30 ¹ ), in the electrical contact springs (40, 40 ¹ ) are arranged, and that a contact bolt (23) of the device head (1, 1 ') containing the signaling part (16) is mounted in the pipe socket (32). 8. Signaling device according to one of the preceding claims, characterized in that an end flange (35) of the pipe socket (32) of the feed part (33) abuts the space (48) on an inner surface of the housing (30, 30 ') that the pipe socket (32) on the space (48) of the housing (30, 30 ') facing the end face is closed off by a closure cover (36) and that the closure cover (36) of the pipe socket (32) has a trough (37) for receiving an end face of the Contact pin (23). 9. Signaling device according to one of the preceding claims, characterized in that on the end face of the pipe socket (32) in the region of the sealing cover (36) conductor connections (41, 41 ') of the contact springs (40, 40') in the region of the casting resin (53 ) are introduced and that the contact springs (40, 40 '), starting from the inner surface of the pipe socket (32) of the feed part (33), are directed obliquely inwards in the direction of the closure cover (36). 10. Signaling device according to one of the preceding claims, characterized in that base webs (38, 38 ') of the contact springs (40, 40') of the feed part (33) of wall parts (39) of the pipe socket (32) are gripped and that an insertion bevel (34) is formed on the end region of the pipe socket (32) facing the device head (1, 1 '). 11. Signaling device according to one of the preceding claims, characterized in that the pipe socket (32) of the feed part (33) is arranged in the region of a compression spring (45) acting in the longitudinal direction of the pipe socket (32), one end of which on the housing (30, 30 ') and the other end of which is supported on a pressure piece (44) which, against the force of the pressure spring (45), is mounted on the housing (30, 30') in a direction against it. 12. Signaling device according to one of the preceding claims, characterized in that in an explosion-proof encapsulated chamber (62) of the housing (30,30 ') in addition to the space containing the voltage limiter and the current limiter (48) at least one actuatable via the pressure piece (44) Microswitch (63) is arranged. 13. Signaling device according to one of the preceding claims, characterized in that a stroke compensation part (55) is arranged between the pressure piece (44) and the microswitch (63), which has a pot bolt (56) with a compensating spring mounted thereon in a form-fitting manner (57) That between a base wall (58) of the pot bolt (56) and the microswitch (63) in the chamber (62) of the housing (30, 30 ') a plunger (69) is arranged, which in an explosion-proof gap bushing (60) in the wall (61) of the housing (30, 30 ') is guided so as to be axially displaceable, that the pressure piece (44) is assigned a latching device (54) with two switching locks and that the housing (30, 30 ') has an approximately hood-shaped holding frame (46) which holds the pressure piece (44) with the pressure spring (45) and the stroke compensation part (55) and the locking device (54) engages. 14. Signaling device according to one of the preceding claims, characterized in that the contact pin (23) of the feed part (33) has an axial conductor (24) arranged in the insulating sleeve (26), on which the one contact spring (40) of the pipe socket (32) abuts, and on the insulating sleeve (26) has an outer sleeve conductor (27) on which the other contact spring (40 ') rests, and that the contact bolt (23) of the device head (1,1') with a collar (28) in a luminaire housing (21) is arranged and that connecting conductors (25, 29) are led from the collar (28) and from the axial conductor (24) to the signaling part designed as a lighting element (16). 15. Signaling device according to one of the preceding claims, characterized in that the lighting element (16) in a reflector (17) of the lamp housing (21) is arranged and embedded in a translucent casting (20). 16. Signaling device according to one of the preceding claims, characterized in that the lighting element (16) of the device head (1, 1 ') is covered by a preferably colored (red, green) lens (15, 15') and that the device head (1 ) above the light element (16) and the lens (15) preferably has a translucent cover (13). 17. Signaling device according to one of the preceding claims, characterized in that the lighting element (16) in the device head (1.1 ¹ ) with a ceramic carrier and bonded LE _D chip is designed as a CERLED (19) and with a carrier plate (18) and at least two, preferably about five to twenty optoelectronic lighting parts is designed as a CERLED lighting unit. ₁ 8. Signaling device according to one of the preceding claims, characterized in that the device part (1, 1 ') containing the signaling part (16) has a sleeve-shaped front ring (11) encompassing the lens (15, 15'), the outside of a thread (12) of an insert body (3) which penetrates a wall (2) of a control cabinet or the like in a hole (4) and which is fastened to the inside (8) of the wall (8) with a fastening nut (9) mounted on a threaded part (10). 2) is screwed tight. 19. Signaling device, in particular according to claim 1, characterized in that the device head (1 ') with the lighting element (16) and a push button (70) is designed as an explosion-protected switching light unit and that the outer lens (15') of the lighting element (16) is arranged in the push button (70) which is axially displaceable in the direction of the housing (30 ') in the device head (1') and to which a pressure sleeve (71) axially displaceable in the insert body (3) against the force of a helical spring (72) is assigned, which acts against the pressure piece (44) surrounding the pipe socket (32).

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