Membrane in plastic materials for loudspeakers

Abstract

 The membrane of the acoustic component can be obtained by means of hot compression from the plate material employing in moulding the active part of relieved screened mould in order to generate a reticular system of bright surface with transparent room intervals.
The proceeding enables the structural modification to the replies in frequency originated by the different elasticity obtained from the material treated in this way.
As a consequence, higher elasticity and membrane resistance can be obtained which allows a wider range of possibilities in the air percussion and consequently a better acoustic yield.

Description

[0001] The invention refers to a new conception proceedure for obtaining membra nes in plastic materials for the acoustic components of loudspeakers which substantially, in the moulding phase, determines the structural mo dification of the initial homogenous material of the plate while increas ing its elasticity and resistance.

[0002] The loudspeaker is a sound diffusing device with power and frequency high er than the normal ones, to be used for manifold employs. It essentially consists of a magnetic circuit, of a basket and of an acoustic component properly assembled. Underlaid to tension differences, the device generates magnetic fields which determine the motion of the mobile coil. As this one is fastened to the acoustic component, it strikes the air and originates the sound. For the best condition of employ, the acoustic diffuser must be in the position of strike the air theoretically in an infinite range of vibrations. This acoustic component, which is a deter minating part in the acoustic yield of the loudspeaker, at present is manufactured in a version with cellulous material. This type of membrane has a modest elasticity and resistance since the cellulous material limitates the range and the power of these vibrations and with the time it causes the deterioration of the component particularly because of the condensate humidity and/or the light radiations. In another version, at present and acoustic component is used which employs a membrane in plastic materials. This realization, in comparison with the previous ones, increases the membrane resistance to atmosphere agents, but it leaves the acoustic yield nearly unchanged.

[0003] If compared with the present types of membranes, the invention object performs an additional increase of resistance and a substantial improvement of the acoustic yield and power maintenance. This is possible because, in the membrane forming, the plastic material is properly operated by means of a structural transformation which enable an improvement of the above mentioned features.

[0004] The proceeding foresees the conformation or previous disposition of the active wall of the forming mould with relief screening in order to determine, in the concave part of the membrane, walls with bright surface resulting from the strike of the above screened form and transparent space intervals. The membrane thus carried out turns out to be more resistant and elastic with consequent increase of the answers in frequency. Accordingly a wider range of possibilities is allowed in the air striking and, therefore, a better total acoustic yield.

[0005] In a version, the conventional mould can be previously prepared for the membrane forming by fitting, on the walls of its active part, a support in relief screening leaf be means of sticking or otherwise. The forming phase is foreseen with heat delivery through preheating of the mould performed by a resistance assembly inserted into it.

[0006] A form of execution is illustrated in an indicative way by the drawings of Table 1. With reference to this one, fig. 1 is the perspective view of the loudspeaker. Fig. 2 is its side view and fig. 3 its front one.

[0007] To compose a loudspeaker, a magneti group 1 is used on which a basket 2 has been fixed by nails and mobile coil 3 mounted, and then a membrane 4 made according to the invention by means of sticking with centre square 5 and nucleus cover 6 fitted by sticking in a similar way. The whole is blocked by means of an annular gasket 7 which is sticked too in similar way. The two polarities 8 and 9 of the mobile coil 3 are connected by tinning to the terminal board 10.

Claims

1) Membrane in plastic materials for loudspeakers, characterized by the fact that foresses the conformation or previous disposition of the active wall of the forming mould with relief screening in order to determine, in the concave part of the membrane, walls with bright surface resulting from the strike of the above screened form and transparent space intervals. The membrane thus carried out turns out to be more resistant and elastic with consequent increase of the answers in frequency.

2) Membrane in plastic materials for loudspeakers, as described in claim 1, characterized by the fact that in a version, the conventional mould can be previously prepared for the membrane forming by fitting, on the walls of its active part, a support in relief screening leaf by means of sticking or otherwise. The forming phase is foreseen with heat delivery through preheating of the mould performed by a resistance assembly inserted into it.

3) Membrane in plastic materials for loudspeakers, as described in claim 1, characterized by the fact that to compose a loudspeaker, a maB. netic group (1) is used on which a basket (2) has been fixed by nails and mobile coil (3) mounted, and then a membrane (4) made according to the invention by means of sticking with centre square (5) and nucleus cover (6) fitted by stricking in a similar way. The whole is blocked by means of an annular gasket (7) which is sticked too in similar way. The two polarities (8 and 9) of the mobile coil (3) are connected by tinning to the terminal board (10).

Drawing