Electrical connectors – With supporting means for coupling part – Comprising or for use with supporting panel
Reexamination Certificate
1997-12-09
2001-08-28
Paumen, Gary F. (Department: 2833)
Electrical connectors
With supporting means for coupling part
Comprising or for use with supporting panel
Reexamination Certificate
active
06280248
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a hold-down element for holding an electrical and/or electronic component onto a substrate, particularly for mounting a connector onto a printed circuit board, comprising a first part for engaging the substrate and a second part for engaging the substrate and a second part for engaging the component to be mounted, which first part has an essentially flat, elongated shape provided with means for engaging in a clamping manner in a mounting opening of the substrate, said means comprise a member which is raised with respect to the plane of the first part.
2. Brief Description of Prior Developments
Many different embodiments of hold-down elements of this type are know from the prior art.
European Patent Applications 0,366,964 and 0,497,554 describe hold-down element of a first type in which the first part, to be received in a mounting opening, is provided with retention hooks or retention teeth, which, in the mounted state, provide the required force for securing the respective component to the substrate by biting into the wall of the mounting opening.
Hold-down elements of this type can be used only for mounting components on substrates having such a structure that the relevant retention hooks or retention teeth can bite into it. When mounting on glass substrates, such as, for example, the substrate of a liquid crystal display device, such hold-down element cannot generally be used. For this purpose, in practice, use is made of hold-down elements of a second type which engage in a clamping manner in a mounting opening of the substrate. A hold-down element of this type is, for example, described in U.S. Pat. Nos. 3,954,242 and 5,145,405.
The hold-down element know from U.S. Pat. No. 4,538,878 is rather a combination of said first and second type.
Hold-down elements provided with retention hooks or retention teeth must be constructed in a relatively robust manner so that they can withstand the relatively powerful force required for inserting them into a mounting opening. It should also be borne in mind that these hold-down elements have to have large dimensions such that they also provide a sufficient mounting force in mounting openings whose dimensions are subject to a relatively high tolerance, for example, of the order of magnitude of 5 to 10%. Clearly, the mounting force is highest in the case of mounting a hold-down element of relatively large size in a mounting opening which, as a result of tolerance, is relatively small.
Hold-down elements which are to be mounted in a clamping manner in a mounting opening are generally constructed so as to be relatively wide, in order to provide the required fastening power, such as, for example, the hold-down element disclosed in the above mentioned U.S. Pat. No. 5,145,407.
In view of present day attempts to achieve a reduction in the scale (miniaturization) of electronic components, which, for example, include attempts at achieving connectors having a pitch distance between the contact elements of, for example, 1 mm or 1.27 mm, with the relatively thin-walled housing associated therewith, hold-down elements provided with retention hooks or retention teeth are unsuitable owing to the risk of damage to the housing resulting from the relatively high mounting forces exerted hereon during mounting.
Owing to their size, wide hold-down elements are unsuitable for being received between contact elements placed close to one another, which is the case, for example, with connectors which have to be mounted adjacent to one another without position loss (“end-to-end stackable”).
SUMMARY OF THE INVENTION
The invention is therefore based on the provision of a hold-down element which is particularly suitable for use with electrical or electronic components of reduced dimensions (miniaturized components).
To this end, the invention provides a hold-down element in which the said means, for engaging onto the substrate, the first part, to be received in a mounting opening, being constructed so as to be weakened in an area which is offset with respect to the raised member, so that the first part, under the influence of a force exerted thereon during the insertion of the hold-down element into a mounting opening, can diverge in the opposite direction to the raised member and can engage the substrate by means of the divergent portion in the mounting opening.
Owing to its essentially flat shape, the first part of the hold-down element according to the invention, to be inserted into a mounting opening, can extend, for example, between the contact element of a miniaturized connector without risk of undesired electrical connections between adjacent contact elements or the connection ends for the connection of an electrical circuit wiring thereof.
The first part having the raised member must have a size with respect to the mounting opening such that, when it is mounted, sufficient mechanical resistance is encountered, which imposes a mounting force such that the first part is brought to the location of the weakened area therein as far as the intended divergence. Owing to the lack of elements having to bite into the material of a substrate, a considerably smaller force is required for inserting the hold-down element according to the invention in a mounting opening and, as a consequence, there is a considerably lower degree of mechanical load on the housing of a component during mounting thereof than is the case with hold-down elements of the above mentioned first type.
The divergence of the hold-down element which is achieved by means of, according to the invention, selectively weakening the first part of the said hold-down element, to be received in the mounting opening, provides an additional fastening action supporting the raised member. The divergence of the first part holds the raised member rigidly against the wall of the mounting opening, as a result of which differences in tolerance in the mounting opening have a negligible effect on the mounting force to be achieved.
Because the first part of the hold-down element according to the invention makes contact via its divergent portion with the wall of the mounting opening after the first part has been inserted therein, in the case of through-metallized mounting openings a more reliable electrical contact is achieved between the hold-down element and the metal layer of the mounting opening than with the know hold-down elements. In face, in the latter case, those parts of the hold-down element which provide the mounting force slide over the metal layer of the mounting opening during mounting. This results in a portion of the relatively thin metal layer being scraped off, which has an unfavorable effect on the electrical connection to be achieved between the hold-down element and the metal layer, for example, for the purposes of earthing. The hold-down element is consequently also very suitable as a connection end for an electrical connection of the relevant component with a circuit wiring. Electrical connections of this type are also referred to by the term “press-fit” in the English language specialist literature.
In contrast to a hold-down element which engages a substrate by biting into it, the additional clamping action provided by the divergent portion of the hold-down element according to the invention also means that changes occurring in the shape or dimensions of the mounting opening, for example, due to temperature variations, during the forecast service life, are accurately matched.
By causing the first part to diverge in the opposite direction to the raised member, a centering action of the hold-down element with respect to the mounting opening is also achieved, which is particularly advantageous in those applications where accurate positioning of the component with respect to the substrate is desired. The position of the weakened area with respect to the raised member determines the manner in which the first part diverges in the mounting opening. A weakening extending in the longitudinal direction of the first part will result
Berg Technology Inc.
Hamilla Brian J.
Page M. Richard
Paumen Gary F.
Reiss Steven M.
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