DE2938648C2 - Fastening element for television picture tubes - Google Patents

Description

The invention relates to a fastening element for TV picture tubes in plastic housings or on plastic front frames in TV housings, consisting of a preferably triangular profiled insert made of plastic, which is in corresponding Trough-shaped recesses in the interior of the plastic housing or front frame can be used like a plug is and is inextricably connectable to this by form and material connection, and a non-rotatable in screw bolts inserted inside the insert.

State of the art

Television picture tubes have metal eyelets at their four corners, which are attached to the picture tube when the picture tube is installed Screw bolts are pushed and then screwed, perpendicular to the plane of the faceplate, into the Inside of the housing protruding, are attached to the front panel of the device housing against rotation.

In the case of device housings made of plastic, these screw bolts either have to be injected with what leads to difficulties with larger bolts, since the resulting material thickening causes shrinkage phenomena When the housing cools down, they appear as ugly depressions or on the front like that.

For this reason it has become common to use plastic housings or just plastic front frames, to which the picture tube is attached to attach trough-shaped depressions, in which then Fastening elements that contain the screw bolts, inserted like a plug and by gluing be permanently connected (DE-OS 19 01 830, DE-GM 69 48 624).

The screw bolts are immovable

Tension can occur if the picture tube fastening eyes are not exactly all in one Lie level if z. B. one or more eyelets

are slightly bent. The eyelets are then at the Screwing pulled into a predicament, whereby impermissible forces are transferred to the picture tube.

As is well known, the picture tube fastening eyes are with

very large mounting holes so that the

ίο The picture tube can be centered in the housing cutout. It now often happens that the picture tubes, which are well centered in the factory, pass through rough ones during transport external influences (impact, fall) within the match play slip out of their position. The picture tube The surrounding air gap then becomes uneven, which is extremely annoying for the viewer

In order to improve the seat of the picture tube caused only by frictional connection, it was necessary to use the Tighten the fastening screws with extreme force or better adhering washers with a rough surface underlay. The problem of the slipped picture tube has not yet been completely resolved will.

Recently, televisions with a desk-like beveled front panel have come onto the market, and so has it Whole plastic housings were also injected, with the front panel for design reasons was not made vertically, but slightly inclined.

With such a housing, difficulties arise when spraying the trough-shaped depressions in that, for reasons of injection technology, they must run parallel to the bottom of the housing, so that the injection mold can be opened and closed in a simple manner without additional slides or the like can be.

If the front panel is now inclined and the trough-shaped depressions are not perpendicular to the plane of the front panel with their central axis, then all of the screw bolts are not at right angles with respect to the front panel, but at an angle, which results in inadmissible stresses in the material when the picture tube is screwed on.
If fastening elements are now used in which the screw bolt is firmly inserted from the start at such an angle that it is in the correct direction when inserted into a housing with an inclined front panel, four different types of insert elements are necessary, which

so inevitably leads to mix-ups during assembly.

task

The task is to find a fastening element for picture tubes that can be used in a universal way both can be used for vertical as well as for inclined housing front panels, depending on the position of the picture tube fastening eyes automatically adapts and after installation a non-slip fit of the picture tube guaranteed.

Solution of the task

The object is achieved in that the part of the insert receiving the shank of the screw bolt in Direction of the shaft in the form of a cone is ind that the surface located at the exit of the shaft of the insert is convexly spherical and that the hardness of the material of the insert is selected.

that the inner edges of the metal picture tube fastening eyes when screwing into the spherical Penetrate part of the insert and thereby form a form fit with it in addition to the frictional connection.

advantages

Because the screw bolt can be moved like a pendulum, it fits universally and when screwing on automatically to different bevels of the front panels and to any bent picture tube fastening eyes. ι ο

The convex spherical surface has the advantage that the sharp edges of the metal fastening eyes of the picture tube penetrate into the spherical surface when the screw connection is firmly tightened. This resulting toothing clearly defines the position of the picture tube in the housing. The picture tube can no longer slip if z. B. during transport, the device is subject to high mechanical loads (Shock, fall) is exposed.

For this reason, the fastening element according to the invention with great advantage also with straight front panels, i. H. universal, usable.

In a further development of the invention, the inside of the cone surrounding the screw bolt is also fine ribs that hold the bolt in a central position before assembly.

The advantage of this is that when the picture tube is put on, all screw bolts are in the middle position and this makes putting on the picture tube much easier. The picture tube is then screwed tight and if the screw bolts are in a position that is no longer the central position, the fine ones become Ribs deformed or broken off.

Description of the invention

Fig. 1 shows the fastening element in section and seen in the direction of the screw bolt end.

The Fig.2 shows the fastening element together with the picture eye mounting eyelet in the assembled state.

The fastening element with its insert 1 is like this formed that it is in a trough-shaped recess of the front panel, which is between the corners of the Housing and corners of the picture tube is located and has a preferably triangular shape, plug-like can be used and with your side surfaces 2 with the side walls of the trough-shaped recess can be glued.

The screw bolt 3 has a head 4 which - not visible in the drawing - is flattened on one side and thereby rotatably lies in the recess 5 of the fastening element.

The surface 6 of the fastening element, from which the screw bolt 3 emerges, is spherical.

The center of the ball lies approximately in the head 4 of the screw bolt 3.

The inner surface 7 of the fastening element 1 is designed in the form of a cone that extends in the direction of Exit of the screw bolt 3 from the fastening element 1 expanded

Thus, the screw bolt 3 can be given by the inclination of the conical inner surface 7 Boundaries swing back and forth and automatically adjust when screwing on the picture tube so that inner Tensions due to the inclined position of the fastening element or also due to bent picture tube fastening eyes cannot arise.

In order to have a full support of the screw head inside the To achieve fastening element, an annular projection 9 is inside the recess 5 provided, the material thickness is such that it is as long as the greatest pressure at the points deformed until the screw head rests snugly all around. The advantage is that commercially available screw bolts can be used without any special surface treatment.

Of course, a recess 5 is also conceivable, which is spherical on its base is and with a spherical screw head together in all angular positions a full Edition guaranteed. In this case, however, no commercially available screw bolts could be used. Thus, the solution with the annular projection is the more cost-effective.

In a further development of the invention, the inside of the cone 7 is small, easily deformable or light Knockout projections arranged during assembly, in particular during the placement of the Picture tube hold the screw bolt in the middle position. This will "thread" the four screws into the Picture tube fastening eyelets made easier. When screwing and the resulting self-centering the screw bolts should deform or break out these small projections.

A b b. 2 shows the fastening element after it has been screwed to a metal picture tube fastening eyelet 10.

The nut 12 has the picture tube fastening eyelet 10 on the washer 11 with arrows marked points are pressed into the spherical curved surface.

The picture tube fastening eyelet is now firmly in place.

On the head 4 of the screw bolt is the annular elevation 9, which serves as a support for the head of the Screw bolt is used, has been deformed so that a full support of the screw bolt head takes place.

For this purpose 2 sheets of drawings

Claims (2)

Patent claims: 1. Fastening element for television picture tubes in plastic housings or on plastic front frames in television sets, consisting of a preferably triangularly profiled insert made of plastic, which is in corresponding trough-shaped recesses in the interior of the plastic housing or front frame can be used like a plug and cannot be detached from it due to the form and material connection is connectable, and a twist-proof in the insert inserted inside screw, thereby characterized in that the shaft of the screw bolt (3) receiving part of the Insert (1) is designed in the form of a cone (7) which can be widened in the direction of the shaft and that the surface (6) of the insert located at the exit of the shaft is convexly spherical, and that the hardness of the material of the insert (1) is chosen so that the inner edges of the metal Picture tube fastening eyes (10) penetrate the spherical part of the insert (1) when screwing and thereby form a form fit with this in addition to the frictional connection. 2. Fastening means according to claim 1, characterized in that the inside of the cone (7) is provided with easily deformable or easily knock-out projections (8), which the screw bolts (3) Hold in the direction of the central axis of the cone during assembly.