Patent Description:
When mounting a motor, a fan or another vibrating device on a fixed bearing, it is of particular importance that the connection is vibration-safe. Furthermore, it is of advantage if the connection is be able to absorb at least some of the vibrations in the horizontal direction as well as in the vertical direction (mounting direction) and the corresponding connector can easily be fastened and released. Therefore, there is a demand for having a vibration and shock decoupled connection that decouples the vibration from a main assembly and provides a damping in all three directions of movement. In addition, the connection shall easily be interchangeable, the lock shall be captive and detachable only with suitable tools and the lock shall be tightened with a defined torque.

Conventional connections do not meet one or more of the above-mentioned requirements. For example, a conventional license plate fastener is disclosed in <CIT><NUM> and <CIT> discloses damping element with a bayonet closure.

At least some of the above-mentioned problems are solved by a connection system according to claim <NUM> and a method of connecting according to claim <NUM>.

The dependent claims refer to further advantageous realisations of the claimed subject matter.

The present invention relates to a connection system with a captive connector for establishing a captive connection between a first part and a second part, one of which being a fixed bearing and the other a support element. The first part includes a threaded hole and the second part includes an opening. The connector includes a threaded sleeve, one or more damping washers, and a bolt. The threaded sleeve extends in an axial direction and is configured to be inserted into the opening of the second part with a radial margin. The one or more damping washers are configured to receive the treaded sleeve and to sandwich the second part to provide a damping in the axial direction. The bolt is configured to threadedly engage the hole of the first part, to threadedly engage the treaded sleeve, and to secure the one or more damping washers together with the sandwiched second part at the first part. The combination of both treaded engagements prevents losing the bolt.

The bolt may comprise a bolt head and the sleeve may comprise a shoulder portion to abut the first part upon establishing the connection. The sleeve may have an axial extension to act as a spacer between a bolt head and the first part. The contact may be direct or indirect. For example, an additional ring washer may be arranged between the bolt head and one of the other washers and/or sleeve.

The sleeve comprises a threaded portion to threadedly engage the bolt, e.g. at a position opposite to the first part, when the connection is established. Thus, it may be threaded only at a portion along its axial extension. The threaded portion acts, upon establishing the connection, as a counter nut by exerting a force to prevent a relative rotation between the bolt and the threaded sleeve.

Optionally, the one or more damping washers include a first damping washer and a second damping washer. The second part may then be arranged between the first and second washers when the captive connection is established. The first and second damping washers may further comprise an elastic material and an axial extension to apply a predetermined pressure on the second part, upon establishing the captive connection.

The connection system includes the first part with a threaded hole, the second part with an opening, and one or more captive connectors as described before which are configured to establish a captive connection.

Optionally, the second part comprises a circumferential nut at an outer edge and a damping cord is arranged in the circumferential nut. The first part may comprise a circumferential stepped recess for receiving the outer edge of the second part. The circumferential nut may also be formed in stepped recess of first part. In both cases, the damping cord extends in at least one lateral direction between the second part and the first part to provide a lateral damping between the first part and the second part.

The first part may further include a deepening around the threaded hole. The deepening may be adapted to receive the shoulder portion of the sleeve and to ensure a direct contact of the one or more damping washers to the first part. The washers may exceed radially the deepening around the threaded hole to contact directly the shoulder of the sleeve as well as the first part. For this, the deepness of the deepening may be adapted accordingly so that upper surfaces of the sleeve and the first part are on a same level. This may prevent a relative rotation between the sleeve and the first part when bolt is fastened with a predetermined torque.

Optionally, the first part comprises at least one connection projection with the threaded hole and may include a fastener to attach it to a fixed frame. The second part may comprise at least one support projection with the opening and, optionally, a further fastener for a vibrating device to couple the vibrating device to the fixed frame while providing a vibration damping.

Optionally, the second part comprises at least three corner portions, and the at least one support projection may include multiple support projections formed at the corner portions of the second part.

Further embodiments relate to a method for establishing a captive connection using a captive connector between a first part and a second part, one of which being a fixed bearing and the other a support element. The first part includes a threaded hole and the second part an opening. The method comprises the steps of:.

It is understood that the list of steps does not imply an order and that all functions and effects described previously in conjunction with the captive connector can be implemented as further optional method steps.

Embodiments provide numerous advantages including one or more of the following:
The connection may provide an attenuation in all directions or rotations, i.e. not only in the vertical but also in both horizontal directions. The damping of the carrier in the fastening direction (vertical direction) is provided by the damping washers, whereas the damping of the carrier in the horizontal directions of movement is provided by the circumferential damping cord which can be deformed relative to the fixed bearing.

The fastening is provided by a spacer formed as a threaded sleeve, which acts as a captive screw. Hence, embodiments allow an easy access of the captive, but detachable fastening of the connection in combination with the three-dimensional decoupling and damping. It thus overcomes the deficiencies of the conventional connectors.

Various embodiments of the present invention will be described in the following by way of examples only, and with respect to the accompanying drawings, in which:.

Various examples will now be described more fully with reference to the accompanying drawings, in which some examples are illustrated.

Accordingly, while examples are capable of various modifications and alternative forms, the illustrative examples in the figures will herein be described in detail. It should be understood, however, that there is no intent to limit examples to the particular forms disclosed, but on the contrary, examples are to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

The terminology used herein is for the purpose of describing illustrative examples only and is not intended to be limiting. It will be further understood that the terms "comprises," "comprising," "includes" and/or "including," when used herein, specify the presence of stated features, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which examples belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealised or overly formal sense unless expressly so defined herein.

<FIG> depicts a captive connector according to an embodiment of the present invention. The captive connector is suitable to connect a first part <NUM> with a second part <NUM>, wherein one of them may represent a fixed bearing (for example the first part <NUM>) and the other one provides a support element (for example the second part <NUM>). The support element <NUM> may provide support for a device such as a fan or an electric motor or any other device which shall be secured while it produces vibrations or shocks. The captive connector shall decouple and protect the first part <NUM> as well as the second part <NUM> by damping any vibrations and/or shocks. Embodiments achieve this protection in both directions, the first part <NUM> is protected against the second part <NUM> and vice versa.

For this, the captive connector includes a sleeve <NUM>, a damping washer <NUM> and a bolt (or screw) <NUM>. The sleeve <NUM> extends through an opening <NUM> of the second part <NUM> and through the damping washer <NUM>. The sleeve <NUM> comprises a threaded portion <NUM> for threadedly engaging the bolt <NUM>. The bolt <NUM> provides another threaded engagement with the first portion <NUM> which in turn includes a threaded hole <NUM> for receiving the bolt <NUM>. The threaded portion <NUM> may be provided only at a (end) portion of the sleeve <NUM> which simplifies the screwing.

When establishing the captive connection, the bolt <NUM> gets first into a threaded engagement with the sleeve <NUM> and later-on with the threaded hole <NUM> of the first part <NUM>. Eventually, an axial force is exerted on the washers <NUM> and the sleeve <NUM> which will block a relative rotation of the sleeve <NUM> and the first part <NUM>. This results in a counteraction of the sleeve <NUM> and, thereby, achieves the captive connection. The sleeve <NUM> thus acts as a counter nut.

In order to achieve the locking, the bolt <NUM> may be fastened with a predetermined torque that ensures an activation of the counter action of the sleeve <NUM>. Furthermore, the locking mechanism may primarily be caused by the interaction of the bolt <NUM> with the sleeve <NUM>. There is no need to fasten the bolt <NUM> particularly strong to the first part <NUM>. Thus, the internal treads in the hole <NUM> are not subject to strong torques preventing damages at these threads. This represents an advantage, because a damaged bolt <NUM> and/or sleeve <NUM> may easily be replaced - a damaged thread in the hole <NUM> cannot be replaced that simple.

The washer <NUM> may comprise several portions or several elements to sandwich the second part <NUM> on both sides of the axial direction Z (fastening direction) to provide an axial damping for the second part <NUM> relative to the first part <NUM>. For example, the washer <NUM> may include a groove where the second part <NUM> can be inserted with its opening <NUM> (e.g. when it is formed as a recess). However, without limitation, it will be assumed in the following that there are two washers <NUM>, a first washer <NUM> and a second washer <NUM>, that sandwich the second part <NUM>.

The opening <NUM> or the second part <NUM> may be formed to provide a radial margin <NUM>, which provides space for lateral shifts or lateral vibrations of the second part <NUM> relative to the bolt <NUM> and/or the first part <NUM>. It is understood that the lateral shifts are perpendicular to the axial direction Z and may include vibrations along the X- or Y-direction.

The washers <NUM> may comprise an elastic or deformable material to allow the damping of the second part <NUM> relative to the first part <NUM>. For example, the material may comprise a predetermined shore hardness and/or size or thickness of the washers to achieve a desired damping effect.

The sleeve <NUM> may comprise an extension along the axial direction Z such that the bolt <NUM> abuts (directly or indirectly), upon establishing a captive connection, to the sleeve <NUM>. Therefore, the sleeve <NUM> may act as a spacer by providing an abutment for the bolt <NUM>. As a result, the second part <NUM> is not squeezed between by the washers <NUM>, but is allowed to perform a limited damped movement in the axial direction Z. An optional ring washer <NUM> may be provided between the washers <NUM> and the bolt <NUM> to provide a solid abutment for the elastic washers <NUM>.

The washers <NUM> may have a thickness along the axial direction Z which, together with the thickness of the second part <NUM>, is larger than the axial extension of the sleeve <NUM>. Thus, when establishing the captive connection, the second part <NUM> is secured between the washers <NUM> under a predetermined pressure to allow a safe attachment while providing vibration absorption up to a degree determined by the material of the washers <NUM>.

The first part <NUM> may include a deepening <NUM> around the threaded hole <NUM> and the sleeve <NUM> may comprise a shoulder portion <NUM>. The deepening <NUM> is adapted to receive the shoulder portion <NUM> of the sleeve <NUM> and to ensure a direct contact of the exemplary second washer <NUM> to the first part <NUM>. In addition, the second washer <NUM> is in direct contact with the should portion <NUM> so that, when establishing the captive connection, the acting axial force will prevent a rotation of the sleeve <NUM> relative to the first part <NUM> and the sleeve <NUM> can act as counter nut.

Embodiments further provide a damping with respect to the lateral direction(s) X, Y. For this, a damping cord <NUM> between an outer edge portion <NUM> of the second part <NUM> and a recess portion <NUM> of the first part <NUM>. This damping cord <NUM> comprises an elastic or deformable material to allow an absorption of vibrations in the lateral direction(s) X, Y. It is understood that the damping cord <NUM> may be arranged in a groove of the second part <NUM> (e.g. in the outer edge <NUM> as shown in <FIG>) or of the first part <NUM> (e.g. at the stepped recess <NUM>, not shown in the drawings). For example, the material may comprise a predetermined shore hardness and/or size or thickness of the damping cord <NUM> to achieve a desired damping effect.

Embodiments relate also to a connection system including the first part <NUM> and the second part <NUM>. <FIG> shows a cross-sectional view of an exemplary connection system according to embodiments, wherein the first part <NUM> represents a fixed bearing onto which the second part <NUM> is mounted as a support element. This connection has an integrated vibration and shock decoupling implemented by the captive connector of <FIG>.

For example, the captive connector is formed in projections <NUM>, <NUM> of the first part <NUM> and the second part <NUM> and is shown in the enlarged view in <FIG>. In the depicted embodiment, the first part <NUM> includes connection projections <NUM> and the second part <NUM> includes support projections <NUM>, wherein the threaded hole <NUM> is included in the connection projections <NUM> and the opening <NUM> is included in the support projections <NUM>.

In is understood that the second part <NUM> may be any suitable support element allowing to mount, e.g., any vibrating device thereon. Similarly, the first part <NUM> may represent part of a fixed bearing or may be attached to a fixed bearing to provide a solid/fixed support for the exemplary vibrating device (not shown in the <FIG>).

<FIG> shows a perspective view on an exemplary connection system according to embodiments. The second part <NUM> represents the support element for the exemplary vibrating device which can be mounted on the second part <NUM> using fastening elements <NUM> (e.g. screw connections). The second part <NUM> may or may not have a through hole as shown in <FIG>. The second part <NUM> may have to a rectangular or a triangular shape, wherein support projections <NUM> at the corner portions of the second part <NUM> accommodate the captive connectors.

Therefore, the second part <NUM> can be mounted on almost any fixed bearing <NUM> while allowing a vibration absorption in the axial direction Z as well as in the horizontal directions X and Y. In addition, if the first and second part <NUM>, <NUM> are non-circular in the horizontal X,Y-plane, the stepped recess <NUM> of the first part <NUM> receiving the outer edge portion <NUM> of the second part <NUM> will absorb any torque around the vertical axis Z acting between the first and second part <NUM>, <NUM>. Again the damping cord <NUM> will provide a damping also with respect to these torques.

<FIG> depicts schematically a flow chart of a method for establishing a captive connection according to another embodiment. The captive connection may connect the first part with the second part. The first part may include the threaded hole and the second part may include an opening. The method comprises:.

Advantages of the embodiments include at least the following:.

It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its scope.

Claim 1:
A connection system including:
a first part (<NUM>) with a threaded hole (<NUM>);
a second part (<NUM>) with an opening (<NUM>); and
one or more captive connectors for establishing a captive connection between the first part (<NUM>) and the second part (<NUM>), one of which being a fixed bearing and the other a support element, the first part (<NUM>) including the threaded hole (<NUM>) and the second part (<NUM>) including the opening (<NUM>), the connector comprising
a threaded sleeve (<NUM>) extending in an axial direction (Z) and configured to be inserted into the opening (<NUM>) of the second part (<NUM>) with a radial margin (<NUM>);
one or more damping washers (<NUM>) configured to receive the treaded sleeve (<NUM>) and to sandwich the second part (<NUM>) to provide a damping in the axial direction (Z); and
a bolt (<NUM>) configured:
to threadedly engage the hole (<NUM>) of the first part (<NUM>),
to threadedly engage the treaded sleeve (<NUM>), and
to secure the one or more damping washers (<NUM>) together with the sandwiched second part (<NUM>) at the first part (<NUM>),
wherein both treaded engagements prevent losing the bolt (<NUM>),
the sleeve (<NUM>) comprising a threaded portion (<NUM>) to threadedly engage the bolt (<NUM>), wherein the threaded portion (<NUM>) acts, upon establishing the connection, as counter nut by exerting a force to prevent a relative rotation between the bolt (<NUM>) and the threaded sleeve (<NUM>).