Loudspeaker unit

A frame for a loudspeaker unit used, for example, in a television receiver, has provisions for optionally fastening one type of loudspeaker to the frame by a positively-locking fastening arrangement or another type of loudspeaker by screw fastening. Specifically, the frame includes both a positively-locking click-stop arrangement for snap-in fastening, and also clip elements for holding the loudspeaker during a screwing operation.

FIELD OF THE INVENTION 
The invention concerns an arrangement for fastening a loudspeaker to a 
frame. 
BACKGROUND OF THE INVENTION 
A loudspeaker unit generally consists of a frame, which serves as a sound 
guide, and has a sound opening and a loudspeaker fastened thereto. The 
frame can be, for example, the front portion of a television receiver, the 
front side of a loudspeaker box, or the wall of a radio mounted on the 
dashboard of a motor vehicle. 
It is known to secure the loudspeaker to the frame by a positively-locking 
so-called click-stop or snap-in fastening arrangement. In this case, the 
fastening operation can take place by a pure translation movement of the 
loudspeaker, which is advantageous particularly for assembly by robots. 
Moreover, in this solution, no screws, which form additional components 
and which lengthen the time required for the fastening operation, are 
necessary. Such a fastening arrangement is advantageous particularly for 
loudspeakers which have a plastic chassis frame. Fastening a loudspeaker 
by means of a positive-locking click-stop or snap-in fastening 
arrangement, without screws, to the front frame of a television receiver 
housing is described in German patent DE-GM No. 84 02 128. 
On the other hand, it is known and, in many cases necessary, to secure the 
loudspeaker to the frame with screws. This solution is preferred 
particularly in the case of loudspeakers with a metal chassis because a 
click-stop or snap-in fastening arrangement is less advantageous for this 
purpose. Many equipments optionally utilize either loudspeakers with a 
plastic chassis or with a metal chassis. In that case, different types of 
fastening arrangements are necessary. 
SUMMARY OF THE INVENTION 
The invention is directed to a frame for a loudspeaker unit which is 
constructed in such a way that different types of loudspeakers can 
optionally be fixed to the same frame by a positively locking click-stop 
fastening operation, suitable for assembly by robots, or by a screw 
fastening operation. 
Both types of fastening, namely that by means of a positive-locking 
click-stop fastening and that with screws, to the same frame are optimized 
by the solution according to the invention. Therefore, the same frame can 
be used for both kinds of fastening. This is particularly advantageous 
with respect to production and storage. Both kinds of fastening allow a 
pure translational movement of the loudspeaker, that is a movement in 
which all the points on the loudspeaker move in a straight line. This is 
particularly advantageous for assembling loudspeaker units using robots.

DETAILED DESCRIPTION OF THE DRAWINGS 
To facilitate an understanding of the following description, concurrent 
reference to two or more of FIGS. 1-4 will be helpful. 
FIG. 1 shows the front frame 1 of a television receiver with the sound 
opening 2 for an oval loudspeaker. On diametrically opposite points of one 
diagonal line through the area of the opening 2, there is provided rigid 
projections 3 with respective openings 4. The projections 3 are injection 
moulded in plastics integrally with the frame 1. 
In addition, there is provided at each of two diametrically opposite points 
along another diagonal line through the area of the opening 2, a projection 
5 projecting out of the plane of the frame 1. The projection 5 is made 
flexible by a slot 6 in the direction of the plane of the frame 1 and has 
at its upper end a barb-like attachment 7 with a sloped surface. 
The frame 1 also has provided with four tapped holes 8 to receive 
self-tapping screws. 
To fasten a loudspeaker with a plastic chassis by means of a 
positively-locking click-stop fastening, without screws, the loudspeaker 
is urged toward the frame 1 in the direction at right angles to the plane 
of the frame 1. In this way, flexible projections 9 on the chassis of the 
loudspeaker are deflected by the projections 3 until finally barb-like 
ends of the projections on the loudspeaker snap into the openings 4 of the 
projections 3 (see FIG. 3). The loudspeaker is then positively locked on 
the frame 1 without play. The projections 5 on the frame 1 are in this 
case not needed and have no importance in holding the loudspeaker. 
To fasten a loudspeaker with a metal chassis, the loudspeaker is also urged 
toward the frame 1 in the direction at right angles to the plane of the 
frame 1. In this case, flanges 10 of the loudspeaker first strike against 
the projections 7 and thereby causes a deflection of the flexible 
projections 5 radially with respect to the opening 2. In the final 
position, the flanges 10 of the loudspeaker engage and are held under 
barb-like attachments 7 so that the loudspeaker is held by the projections 
5 on the frame 1 (see FIG. 4). This holding including frictional holding is 
not a final fastening but is rather a so-called "pre-fixation" or 
"positional fixing" procedure. That is, serves only for determining the 
position of the loudspeaker so that holes of the loudspeaker flange 
coincide with the tapped holes 8. After the "pre-fixing" or "positional 
fixing" of the loudspeaker, the final fastening of the loudspeaker to the 
frame 1 takes place by screwing two or four screws through the holes in 
the loudspeaker flange and into the tapped holes 8. The loudspeaker does 
not need to be held for the screwing operation, so that the operator has 
both hands free for the screwing operation. Alternately, the screwing 
operation can be performed by robots. Thus, the projections 5 serve for 
temporary positional fixing and holding, and then no longer have any 
importance for fastening the loudspeaker. The projections 3 have no 
importance per se for this kind of fastening. However, they can, if need 
be, serve as guides and as stops for the loudspeaker flange. 
The projections 3 and 5 are offset with respect to the direction of the 
short axis of the oval-shaped opening 2 by an angle of about 15.degree. so 
that the projections can be relatively closely positioned with respect to 
the opening 2. This has the following advantage. If the projections were 
to lie exactly in the direction of the short axis, the space required 
between the projection in the direction of the long axis (section line 
A-A) would be greater. This is particularly disadvantageous in the case of 
a television receiver in which space for mounting the loudspeaker is 
restricted. Thus, a reduction of the spacing between two projections 3 and 
5 and, thereby, an increase in space in the receiver can be achieved by the 
offset position of the projections 3 and 5.