IE41565B1 - Speaker grilles - Google Patents

Abstract

1473047 Speaker grilles; radio constructions NORTHERN ELECTRIC CO Ltd 11 June 1975 [21 June 1974] 25059/75 Headings H4J and H3Q A speaker grille comprises a plurality of parallel ribs 12 in a cover 10 of a housing (not shown) and a mask 17 secured to the ribs 12 (e.g. by sonic welding to smaller ribs 32) on an inner surface of the cover. An aperture (see Fig. 5, not shown) in the mask 17 is at a position to correspond with a speaker position. The ribs 12 each have a cross-section, normal to the longitudinal axis of the rib, substantially in the form of a Z and include upper and lower cross-bars 21, 22 (Fig. 4) connected by a web 23. The ribs are separated by sinuous channels 24, 25 extending completely through the grille. The outer and inner portions 24, 25 are offset relative to each other to substantially prevent direct view between the ribs 12 in a direction normal to the outer surface of the grille. As described the grille is applied to a telephone set including a speaker and microphone. It can also be applied in radio sets and in other forms of communication apparatus.

Description

This invention relates to speaker grilles, narticularly but not exclusively for telephone sets of the type in which a handset is not required, a speaker and a microphone being positioned in the telephone set.

A speaker grille has more than one function. While its primary function is to permit passage of sound from the speaker to the user, as it forms part of thecasing or housing and can be seen, it necessarily has a cosmetic or design function. Ideally the grille should become part of the overall design of the article, not be obtrusive, and at the same time provide protection against items being pushed through the grille. Also, there is an added attraction where the grille extends over an area larger than the speaker if it is not possible to detect just where the speaker is situated.

The present invention provides a speaker grille incorporated in a housing, or a cover for anousing, the gy-jiie comprising a plurality of parallel ribs, a mask secured to the ribs on an inner surface thereof, and an aperture in the mask at a position to correspond with a speaker position; the ribs each having a cross-section, viewed normal to the longitudinal axis of the rib, substantially in the form of a Z shape and ' including upper and lower crossbars connected by a web, the ribs being separated by channels extending completely through the grille from the outside to the inside thereof, each channel being of sinuous form, viewed in cross-section normal to the longitudinal axis of the channel and having outer and inner portions, and the outer and inner channel portions being offset relative to each other to thereby substantially prevent direct view between the ribs in a direction normal to the outer surface of the grille.

There is further provided a housing for a communication apparatus, including a top cover and a speaker grille in said top cover, the speaker grille being positioned at an end of the cover and comprising a plurality of parallel ribs in the cover, a mask secured to the ribs on an inner surface of the cover, and an aperture in the mask at a position to correspond with the speaker position; the ribs each having a cross-section, viewed normal to the longitudinal axis of the rib, substantially in the form of a Z shape and including upper and lower crossbars connected by a web, the ribs being separated by channels extending completely through the grille from the outside to the inside thereof, each channel being of sinuous form, viewed in cross-section normal to the longitudinal axis of the channel and having outer and inner portions, the outer and inner channel portions being offset relative to each other to thereby substantially prevent direct view between the ribs in a direction normal to the outer surface of the grille.

The invention will be readily understood by the following description of one embodiment, as applied to a telephone set by way of example, in conjunction with the accompanying drawings in which:3 Figure 1 is a plan view of the outside of a cover showing a speaker grille; Figure 2 is a cross-section on the line II-II of Figure 1; Figure 3 is a cross-section on the line III-III of Fi gure 1; Figure 4 is a much enlarged cross-section of the grille in the area of circle A °f Figure 3^ and Figure 5 is a plan view of the inside of the cover of Figure 1.

As seen in Figure 1, the top cover 10, forming a portion of a housing (the remainder of which is not shown) for a telephone set which includes a speaker and microphone, has a grille 11 formed at one end as shown in the drawing.

In the particular exaiwle this would be the top end. The grille is composed of a plurality of parallel ribs 12 extending in the direction of the longitudinal axis of the cover. As illustrated in Figure 2 the top and bottom flanges 13 and 14 of the cover 10 are not peroendicular to the top surface 15 of the cover 10 but are inclined outwardly. In the present example the rib formation, formed by the ribs 12, is carried partway down the top end flange 13. However, the ribs are not entirely separate for all the formation. This is seen in Figure 2, where the ends of the gaps between ribs 12 are indicated at 16. The rib formation is carried over onto the end flange 13 for aesthetic reasons. Also seen in Figure 2 is a mask 17.

Figure 3 illustrates, in cross-section, the mask 17 in position in contact with the ribs 12. . Conveniently the mask is sonically welded to the ribs of the grille. This strengthens the ribs and prevents breakage. An aperture is provided in the mask, at a position occupied by the speaker when installed. The shape of the aperture is readily seen at 18 in Figure 5 and the periphery of the aperture 18 is indicated at 19 in Figures 2 and 3.

The ribs 12 are of a specific cross-section. This crosssection is intended to prevent direct access and sight in a direction normal to the top surface 15 of the cover 10 and also up to quite wide angles either side of the normal. The cross-section of the ribs is seen in more detail in Figure 4. Two ribs 12 are illustrated in cross-section, in Figure 4. The cross-section is a modified Z form, having upper and lower cross-bars 21 and 22 respectively, joined by a short web 23, one cross-bar being offset relative to the other.

Each rib 12 is separated from the adjacent rib by a gap whith essentially is composed of two channel portions 24 and 25, each extending substantially normal to the outer surface of the grille 11. The two channel portions are also offset relative to each other such that there is very little, or no direct passage from front to back of the grille.

There is thus formed a sinuous passage and in the examole the outer part - the portion 24?has substantially parallel walls 26, 27, while the inner part - portion 25, has walls 28, 29 which are inclined slightly to give a tapered section with the widest dimension at the inner face of the grille. In the example shown, one wall - 28, is slightly more inclined than the other wall 29. i The two channel portions 24 and 25 unite along a line, indicated by dotted line 30 which extends from the wall 26 of portion 24 to wall 29 of the portion 25 and these are almost in a straight line in the example shown. Thus the two channel portions 24 and 25 are offset relative to each other as viewed in the cross-section of Figure 4. This construction, of course, prevents direct sight or access. Walls 27 and 28 have arcuate portions where they bend round to join the appropriate walls 29 and 26.

The widths of the channel portions 24, 25 and the amount of overlap to provide the gap or throat 31 are dependent on various parameters. Making the channel too narrow will restrict sound emission, while too wide a channel will permit foreign object to be readily inserted and also will affect the appearance detrimentally.

Also illustrated in Figure 4 is the positioning of the mask 17. As stated previously the mask 17 is conveftiently sonic welded to the ribs 12. To facilitate the sonic welding, small ribs 32 extend along each rib 12. In the particular example the ribs 32 are triangular in cross-section coming to a thin edge which is in contact with the mask 17. The ribs 32 act as energy directors, directing ultrasonic energy to the welded area during welding.

The mask 17 is preferably of dark material - black for example. Once the speaker is assembled to the cover 10, it is not possible to discern where the speaker is once the cover 10 is in position on the telephone set base. The grille looks exactly the same the whole width of the cover.

The mask and the grille provide an extremely attractive appearance.

The grille is strong and prevents easy access to the speaker from the outside of the telephone set such that the speaker might receive damage.

The cover with its grille is easily moulded. If the mask 17 was to be dispensed with and the moulding produced with the gaps between ribs extending right through the grille only where the speaker was to be positioned, either a more complex moulding process would be necessary, or the positiion of the speaker would show.

Thus, for example, if the cover 10 was of white material, then if the gaps between ribs were to be produced only where the speaker was to be positioned, white material would be seen between the ribs, except at the speaker position. This would appear black between the ribs at this position. The same comment applies for other colours, except for black and perhaps other very dark colours. To avoid the colour showing between the ribs, a two-shot moulding process could be used. Thus the grille could be formed with gaps between all the ribs, as in the present example, and then the gaps, partially filled by a black material, for example, by filling the channel portions 25 at those parts of the grille where the speaker is not positioned. However, this is expensive, time consuming' and requires an extra mould. The use of the mask 17 avoids these difficulties, and also strengthens the ribs.

A speaker grille in accordance with the present invention is also suitable for various other forms of apparatus, in addition to telephone sets. For example speaker grilles in accordance with the present invention can be used for radio sets and in other forms of communication apparatus.

Claims (5)

1. A housing, or a cover for a housing, having a speaker grille incorporated in a housing, or a cover for a housing, the grille comprising a plurality of parallel ribs , a mask secured to the ribs on an inner surface thereof, and an aperture in the mask at a position to correspond with the speaker position; the ribs each having a cross-section, viewed normal to the longitudinal axis of the rib, substantially in the form of a Z shape and including upper and lower crossbars connected by a web, the ribs being separated by channels extending completely through the grille from the outside to the inside thereof, each channel being of sinuous form, viewed in cross-section normal to the longitudinal axis of the channel and having outer and inner portions, and the outer and inner channel portions being offset relative to each other to thereby substantially prevent direct view between the ribs in a direction normal to the outer surface of the grille.

2. A speaker grille as claimed in claim 1, including ribs extending along the inner surface of each lower crossbar, and in which the mask is in contact with the latter ribs and sonically welded thereto.

3. A housing for a communication apparatus, including a top cover and a'speaker grille in said top cover, the speaker grille being positioned at an end of the cover and comprising a plurality of parallel ribs in the cover , a ma'.k secured to the ribs on an inner surface of the cover and ari aperture in the mask at a position to correspond with the speaker position; the ribs each having a cross-section, viewed normal to the longitudinal axis of the rib, substantially in the form of a Z shape and including upper and lower crossbars connected by a web, the ribs being separated by channels extending completely through the grille from the outside to the inside thereof, each channel being of sinuous form, viewed in cross-section normal to the longitudinal axis of the channel and having outer and inner portions, the 10 outer and inner channel portions being offset relative to each other to thereby substantially prevent direct view between the ribs in a direction normal to the outer surface of the grille.

4. A speaker grille as described herein with reference 15 to the accompanying drawings.

5. A housing as described herein with reference to the accompanying drawings.