HU192602B - Horn loudspeakers of compression chamber, in particular for the application in the damp and explosion dangerous environment - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates to funnel press chamber loudspeakers, in particular for use in a hose and explosive atmosphere, which is a drive transformer (4) in a loudspeaker in a metal housing, preferably a cylindrical metal housing (1), and a conduit (2) on the metal housing (1) suitable opening (8). It is an object of the invention that a filter (9), preferably a bronze filter made by powder metallurgy, is provided in the outlet extension of the drive unit (5). (Figure) -1-

Description

FIELD OF THE INVENTION The present invention relates to funnel-type pressure chamber speakers, particularly for use in a combustion air and explosive environment, which comprises a drive unit, adapter transformer arranged in a metal housing, preferably a cylindrical metal housing, and an aperture for passing through the housing.

Pressure chamber speakers Sb (flame retardant) or. Many solutions have been used to protect Rb (explosion-proof), e.g. pressure-resistant housing, steel membrane, etc. a common feature of which was to protect the loudspeakers operating in hazardous operating conditions by using pressure-resistant components and materials.

SUMMARY OF THE INVENTION The object of the present invention is to provide a simple solution to prevent an explosion and a dangerous situation.

The invention is based on the discovery that if the combustion supply air is displaced from the interior of the loudspeaker in any way, the possibility of flame generation is minimized, and, if a filter is inserted in the outlet of the drive unit, a properly sized and fitted filter In this case, the flame generated by the explosion inside the propulsion system can be cooled to a temperature appropriate to the area of application.

It is an object of the invention that a filter, preferably a bronze filter made by powder metallurgy, is provided at the outlet of the drive unit.

The invention will be described in more detail with reference to the embodiment shown in the drawing, in which a sectional drawing of a speaker according to an embodiment of the invention is shown.

Units known per se are shown in outline only. The metal housing 1 of the loudspeaker has a passage opening 3 for connecting connections. The connections 2 are connected to 4 interface transformers. The drive unit 5 adjacent to the adapter transformer 4 is terminated in an outlet 6.

Inside the metal housing 1, starting from the lead-through opening 3, the adapter transformer 4 and the drive unit 5 are respectively connected. All the air space adjacent to the drive unit is filled with an antistatic, post-cure, form-retaining material, preferably cold-curing synthetic resin 7, all the way up to the outlet 6 of the drive unit 5.

In the outlet extension 6, behind the opening 8 of the outlet extension 6, there is provided a filter 9 having a diameter larger than the diameter of the opening 8, preferably a bronze filter produced by powder metallurgy. Behind the filter 9 is a retaining ring 10 having an internal surface suitable for acoustic conditions, preferably a tapered surface tapering towards the opening 8. The diameter of the filter opening 9 of the retaining ring 10 is smaller than the diameter of the filter 9 but larger than the diameter of the opening 8 or at most equal to the diameter of the opening 8.

According to our experience, bronze filter types can be used in different protection classes Rb and Sb.

many of the following: Protection class filter type particle density / average pore diameter Rb IV / a T 3/70 Rb III T 4/85 Sbl T 5/120

According to the example, the snap-in connectors 11 are also located inside the metal housing 1. All voltages and power switches can be solved outside the drive unit 5 by connecting the corresponding points of the adapter transformer 4 to the terminals 2 formed by a multiple cable. Due to the arrangement, the drive unit 5 is electrically double insulated. The metal acoustic funnel structures, which are inert to Sb and Rb, connected to the drive unit 5 by a thread or bayonet groove, are protected against static charge and are inert to the touch.

Claims (5)

1. Funnel-type pressurized chambers, particularly for use in flammable air and explosive atmospheres 30 for use in a loudspeaker in a metal housing, preferably a cylindrical metal housing, an adapter transformer, and an aperture for passing through connections in the metal housing, characterized in that the drive unit (5) exits A filter (9) is provided in its extension (6), preferably a bronze filter produced by powder metallurgy. Speaker according to Claim 1, characterized in that the opening (8) of the outlet extension (6) has a diameter smaller than that located behind the opening (8). Diameter of 40 filters (9). Speaker according to Claim 1 or 2, characterized in that, behind the filter (9), it has an internal surface corresponding to acoustic conditions, preferably a frustoconical surface tapering towards the opening (8). A retaining ring (10) 46 is provided. A speaker as claimed in claim 3, characterized in that the diameter of the filter opening (9) of the retaining ring (10) is smaller than the diameter of the filter (9) but larger than the diameter of the opening (8) or at most 50 with the diameter of the opening (8). 5. A loudspeaker according to any one of claims 1 to 4, characterized in that the metal housing (1) is an antistatic, post-freezing material which fills the internal airspace, from the through opening (3) to the connection unit (5) to the outlet extension (6). preferably filled with cold-curing resin (7).