Title: Ear protector
The invention relates to an ear protector comprising an ear pad (the part that rests against the ear) and an ear shell (the part that is directed outwardly) on which a bracket is mounted for connecting two ear protectors with each other. In the known ear protector one or more damping layers of synthetic material are interposed between the ear pad and the shell.
The invention aims to improve this known device. To that effect, according to the invention, an additional diaphragm is interposed between the ear pad and the shell, on opposite sides of which diaphragm at least one insert layer may be provided.
The protection of the ears can be improved by forming the diaphragm as a bowl. Further, a reduced transmission of sound is obtained when it is arranged for the diaphragm not be in direct contact with the shell.
When in known manner the ear pad is made of soft rubber or the like, at the outer side of the pad an inwardly turned rim may be provided, an edge of the shell resting against one side of the rim and an edge of the diaphragm resting against the other side..
In a further elaboration in the circumferential wall of the ear pad one or more grooves may be provided, in one of which the circumference of the diaphragm may be mounted. In this way a resilient suspension is obtained, which yields a maximum sound damping.
When, furthermore, a portion of the diaphragm that extends externally relatively to the inner side of the bowl- shaped portion is provided with tapered sliding or locking projections a situation is achieved where depression of the ear pad permits the ear pad to be vented. Thus it is further¬ more achieved that a damping layer can readily be inserted in the bowl-shaped portion because there is only line contact, and the tapered configuration of the projections permits the
material mentioned to be mounted or locked in a simple manner. Furthermore, using moisture-absorbing material for the insert layer will render the ear protector more comfortable to wear.
The diaphragm and the rim portion of the ear pad may be formed in such a way that a fully closed cavity is formed in which a sound-damping filling is arranged.
In a further elaboration of the invention the ear pad may be formed with a recess in the same direction as the diaphragm In the recess mentioned an opening may be provided.
Further, on opposite sides of the recessed portion of the ear pad an insert damping layer may be provided.
Further, the insert layers may each have such dimensions that they fill up the entire accommodating space in radial direction.
In a further elaboration of the invention the shell may be made of polypropylene or a similar hard plastic, and the diaphragm may be made of polystyrene or a similar plastic. The ear pad, finally, may be manufactured by means of injection moulding, for example, and, as noted above, may be made of resilient plastic or the like.
The insert layers, finally, may be made of polyester foam or a similar sound-damping plastic. In addition, polyester has the advantage that it regulates humidity well and thus effects maximum comfort for the wearer.
To further explain the invention, two embodiments of the ear protector will now be described with reference to the accompanying drawings, in which:
Fig. 1 is a cross-sectional view of a part of a complete ear protector; and
Fig. 2 is a view similar to that of Fig. 1 of another embodiment of the ear protector according to the invention.
According to the drawing an ear shell 1, made of PVC, polypropylene, or the like is provided with an ear pad 2, made of rubber, for example. Interposed between the ear shell 1 and the ear pad 2 is a diaphragm 3, made of polystyrene, for
example. Provided next to each of these three elements are insert layers 4, 5, 6, of polyester foam. Cavity 7, which is closed in mounted position and whose outer surface rests against a wearer's head, also contains a sound-damping material, namely a polyester foam filling 8.
As shown in the drawing, the outer edge of the diaphragm rests against an inwardly turned rim 9 of the ear pad, and the innermost edge of the bowl-shaped portion of the diaphragm rests against an outwardly turned rim 10 of the ear pad. Thus the closed cavity 7 is formed in which the aforementioned polyester filling 8 is enclosed, but the filling can be replaced if so desired. As shown further in the drawing, the ear shell is connected to a bracket 15 in a simple manner, namely by means of a screw-and-nut joint 11, 12, a washer 13, and a spacer 14. Other connections are also possible, such as a click-fit or snap connection.
In Fig. 2 like parts are designated by like reference numerals. The differences essentially reside in the fact that the diaphragm 3 is formed somewhat differently, i.e. the bowl- shaped portion is stepped, and the insert layer 5 is arranged in the portion disposed furthest inwardly. Provided outwardly relatively to this insert layer in the "transitional portion" are a plurality of tapered guide ribs 20 which ensure the ear pad can "breathe". The ribs also permit ready insertion of the insert layer, which, furthermore, is retained on account of the projections 20 being of tapered configuration. Further, the circumference of the diaphragm 3 comprises a thickened rim 21, which permits the diaphragm to be readily and properly locked in the corresponding groove 22 of the ear shell 2. A further modification as compared with the embodiment according to Fig. 1 resides in the fact that instead of a screwed joint (11, 12, 13) an ear shell 1 is used comprising lugs 23 each bounding an opening adapted for receiving pins 24 mounted on the bracket 15, in such a way that a snap connection is obtained. Thus a very simple connection is obtained permitting ready assembly and disassembly.
It will be clear that modifications will readily occur to a person skilled in the art without departing from the invention. Thus the shape and the depth of the bowl-shaped diaphragm 3 influence the sound damping.