CONNECTOR, AND METHOD

Abstract

A connector, which is configured to be anchored in a first object with thermoplastic material, defines a proximodistal axis and has a plate portion extending around the proximodistal axis and having a proximal face and a distal face, the proximal face being adapted for a tool to be pressed thereagainst. The connector further includes an attachment structure accessible from the proximal side of the plate portion and/or an interaction element having a sensor and/or actuator. An anchoring skirt protrudes distally from the plate portion and distally and radially outwardly, whereby an outer pocket open towards radially outwardly is formed between the distal face of the plate portion and a proximal face of the anchoring skirt, and an inner pocket open towards distally is formed radially inwardly of the anchoring skirt. The plate portion extends radially further than the anchoring skirt.

Claims

1. A connector configured to be anchored in a first object with thermoplastic material, the connector defining a proximodistal axis and comprising: a plate portion extending around the proximodistal axis and having a proximal face and a distal face, the proximal face being adapted for a tool to be pressed against the proximal face; an attachment structure accessible from the proximal side of the plate portion and/or an interaction element comprising a sensor and/or actuator; an anchoring skirt protruding distally from the plate portion towards distally and radially outwardly, whereby an outer pocket open towards radially outwardly is formed between the distal face of the plate portion and a proximal face of the anchoring skirt, and an inner pocket open towards distally is formed radially inwardly of the anchoring skirt; wherein the connector is capable of being anchored with respect to the first object by causing a tool to press the connector against the first object while the anchoring skirt is in physical contact with the first object and while mechanical energy is coupled into the connector until thermoplastic material of the first object flows relative to the connector and is caused to flow into the outer pocket and the inner pocket.

2. The connector according to claim 1, wherein the anchoring skirt forms an uninterrupted collar extending by 360°.

3. The connector according to claim 1, wherein the anchoring skirt extends around the proximodistal axis.

4. The connector according to claim 1, wherein the anchoring skirt is not rotationally symmetrical.

5. The connector according to claim 4, wherein the anchoring skirt is polygonal and/or comprises a pattern of radial indentations and/or protrusions.

6. The connector according to claim 1, wherein the anchoring skirt forms a distal edge, shaped to rest against a flat first object surface along a contact line defined by the edge.

7. The connector according to claim 6, wherein an edge angle of the edge is at most 120°.

8. The connector according to claim 1, comprising a flow hole having a mouth in the inner pocket, the flow hole extending from the mouth towards proximally.

9. The connector according to claim 1, wherein the attachment structure comprises an attachment bar having an outer thread.

10. The connector according to claim 1, wherein the plate portion extends radially further than the anchoring skirt.

11. The connector according to claim 1, wherein the inner pocket or a flow hole having a mouth in the inner pocket comprises at least one structure that is undercut with respect to axial directions.

12. The connector according to claim 1, wherein the attachment structure protrudes proximally from the proximal face of the plate portion.

13. The connector according to claim 1, wherein the plate portion is one-piece with the anchoring skirt.

14. The connector according to claim 1, wherein the plate portion is of a thermoplastic material and the anchoring skirt is of a not thermoplastic material or of a second thermoplastic material having a substantially higher liquefaction temperature than the thermoplastic material of the plate portion.

15. A method of bonding a connector in a first object with thermoplastic material, the method comprising the steps of: providing the connector according to claim 1; positioning the connector relative to the first object so that the anchoring skirt is in contact with thermoplastic material of the first object to yield an assembly comprising the connector and the first object; using a tool to couple mechanical energy and a pressing force into the assembly until a flow portion of the thermoplastic material of the first object flows relative to the connector and is caused to flow into the outer pocket and the inner pocket, and stopping the mechanical energy, whereby after re-solidification of the flow portion the connector is anchored relative to the first object by the anchoring skirt being embedded in re-solidified thermoplastic material of the first object.

16. The method according to claim 15, wherein the mechanical energy is mechanical vibration energy.

17. The method according to claim 16, wherein the tool is a sonotrode, and wherein coupling the mechanical energy and the pressing force into the assembly comprises pressing a coupling-out face of the sonotrode against the proximal face of the plate portion while the sonotrode vibrates.

18. The method according to claim 16, wherein the tool is a sonotrode, and wherein coupling the mechanical energy and the pressing force into the assembly comprises pressing a coupling-out face of the sonotrode against a distal surface of the first object while the sonotrode vibrates and while the connector is held against the first object.

19. The method according to claim 18, wherein in the step of coupling the mechanical energy and the pressing force into the assembly, the connector is held by a third object to be secured to the first object.

20. A set, comprising the connector according claim 1 and further comprising a sonotrode or sonotrode tip, the sonotrode or sonotrode tip having a coupling-out face that is adapted to couple mechanical vibration and a pressing force into the connector via the proximal face of the plate portion.

21. The set according to claim 20, wherein the sonotrode or sonotrode tip has an axial channel for accommodating the attachment structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In the following, ways to carry out the invention and embodiments are described referring to drawings. The drawings are schematical. In the drawings, same reference numerals refer to same or analogous elements. The drawings show:

[0070] FIG. 1 a side view of a connector;

[0071] FIG. 2, in part, the connector of FIG. 1 in section;

[0072] FIG. 3 a side view of a further connector;

[0073] FIG. 4, in part, the connector of FIG. 3 in section;

[0074] FIG. 5 a view of yet another connector;

[0075] FIG. 6 a view of an even further connector;

[0076] FIG. 7, in cross section a configuration of a first object, a connector and a sonotrode;

[0077] FIG. 8 the connector of FIG. 7 anchored with respect to the first object;

[0078] FIG. 9 a schematical bottom view of an even further connector;

[0079] FIG. 10 a partial section of a variant of a connector anchored with respect to a first object;

[0080] FIG. 11 a (partial) view of a further connector;

[0081] FIG. 12 a partial section of an even further rconnector;

[0082] FIG. 13 a schematic cross section of a sonotrode with a connector;

[0083] FIG. 14 a section through an alternative configuration of a connector, first object, and sonotrode;

[0084] FIGS. 15 and 16 views of further connectors in section;

[0085] FIG. 17 a configuration, in section, of an even further configuration of a connector, object, and sonotrode, further with a washer;

[0086] FIG. 18 a section through the configuration of FIG. 17 without the sonotrode after the anchoring process;

[0087] FIG. 19, in section, an even further, hybrid, connector; and

[0088] FIGS. 20 and 21 views of sonotrode tips depicted in section along a plane through which the axis runs.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0089] The connector 10 of FIGS. 1 and 2 serves as anchor for a third object (not shown) to be fastened to the first object having thermoplastic material. To this end, the connector 10 has an attachment structure 11 in the form of a threaded bar. The threaded bar is arranged centrally with respect to the proximodistal axis 20 and extends proximally from a plate portion 12.

[0090] The connector is, for example, metallic or of plastic (thermosetting or thermoplastic) or possibly of ceramics. If the connector is liquefiable, the liquefaction temperature is such that it is not flowable at temperatures at which the thermoplastic of the first object is flowable. For example, the temperature at which material of the connector may become flowable, if at all, is higher than the melting temperature of the first material by at least 50° or at least 80° C.

[0091] The plate portion 12 forms a proximal face 13 that may serve as incoupling surface for a sonotrode by which a pressing force and mechanical vibration are coupled into the connector. The plate portion 12 also forms a distal face 14.

[0092] The proximal face 13 has an outer portion that is essentially plane and perpendicular to the proximodistal axis 20, whereby the coupling with the sonotrode is particularly efficient. A rounded or slightly tapering shape of the incoupling surface, however, would be possible also.

[0093] Distally of the plate portion 12, the anchoring skirt 15 protrudes towards distally and radially outwardly. The anchoring skirt distally ends in an edge 16. In the anchoring process, the edge firstly serves as energy director. Secondly, the edge serves for guiding volume portions of the flowable thermoplastic material towards inwardly and outwardly, respectively. The inclination angles α, β of the tapers of the inner and outer faces 181, 172 leading to the edge from inwardly and from outwardly, respectively, may be similar, as in the illustrated embodiment, but may also be different. For example, the inclination angles may be, in the definition according to FIG. 2, between 20° and 60°, and/or they may differ from each other by not more than 20°. It is also possible that at least one of the angles, especially the angle β is more than 60°, for example up to 90° or even higher than 90° (of course, only one of the angles α, β can be higher than 90°).

[0094] The sharpness of the edge 16, i.e. the angle 180°-α-β is also a potentially important parameter. It has been found that sharp edge angles 180°-α-β make fixation without any undesired (depending on the particular application) angles easier to achieve. For example, in embodiments the edge angle may be chosen to be at most 120°, at most 90° or for example (in embodiments different from the one shown in FIG. 4) even at most 60°, at most 50° or less.

[0095] Between the plate portion 12 and the anchoring skirt, particularly between the distal face 14 and an outer face 171 of the anchoring skirt 15 an outer pocket 17 is formed. The outer pocket 17 runs around the anchoring skirt 15, is confined towards radially inwardly and towards distally by the anchoring skirt, towards proximally and radially inwardly by the plate portion (inner part of distal face 14) and is open towards radially outwardly.

[0096] For forming the pocket 17 together with the plate portion 15, the outer face 171 of the anchoring skirt faces towards outwardly and proximally, i.e., it has a normal pointing towards radially outwardly and proximally.

[0097] Radially inwardly of the anchoring skirt, an inner pocket 18 is formed. The inner pocket is confined towards radially outwardly by the anchoring skirt 15 and is open towards distally. Towards proximally, the inner pocket is partially confined by the plate portion. However, from the inner pocket, a flow hole 19 (having a flow hole mouth 191) extends towards proximally into the body of the connector. The flow hole 19 serves for accommodating material of the first object that has been displaced towards inwardly by the anchoring skirt. In FIG. 2, a level 30 to which the connector is anchored relative to the first object is depicted (level 30 shows the approximate position of the proximally facing surface of the first object relative to the connector after the anchoring process, the level being mainly defined by the shape of the connector). The inner end of the flow hole 19 is generally proximally of the level, so that there can be a backflow towards proximally of material displaced towards inwardly by the anchoring skirt.

[0098] A further function of the inner pocket and/or of a flow hole may be to yield additional tensile strength by providing structures into which the thermoplastic material may flow and that yield, after re-solidification, a further positive fit. In FIGS. 1 and 2, as well as in FIGS. 3 and 4 described hereinafter, there is illustrated a slight undercut 29 of the flow hole. By the thermoplastic material penetrating therein, this kind of additional tensile strength (strength of the connection against axial pulling forces) is caused. The inner pocket and/or the flow hole may include further undercut structures as explained hereinafter.

[0099] The variant of FIGS. 3 and 4 distinguishes from the embodiment of FIGS. 1 and 2 mainly in that the flow hole extends further towards proximally, whereby there is essentially no restriction on the volume of thermoplastic material displaced inwardly and being caused to flow back. This embodiment is suited for anchoring the connector somewhat deeper (see level 30) in the first object, compared to the embodiment of FIGS. 1 and 2.

[0100] In the embodiment of FIG. 5, the anchoring skirt 15 is not round (not circularly symmetrical about the proximodistal axis) but has a generally polygonal shape, namely a triangular shape. Any shape that is not symmetrical about the proximodistal axis may be advantageous in situations where the connector does not only have to take up axial loads with respect to the first object but potentially also torques around the proximodistal axis, for example during a process of fastening a third object to the first object.

[0101] Also the embodiment of FIG. 6 has an anchoring skirt 15 with shape that is not circularly symmetrical about the proximodistal axis. More in concrete, the anchoring skirt has inner structures 21 of a pattern of radial indentations and protrusions.

[0102] In addition or as an alternative, the anchoring skirt could also have outer such structures.

[0103] In FIGS. 7 and 8, very schematically a process of anchoring a connector 10 with respect to a first object 1 is illustrated. The first object 1 is illustrated to be a relatively thin plate of thermoplastic material.

[0104] The connector 10 shown in FIGS. 7 and 8 has the following features that are distinct it from the embodiments of FIGS. 1-4: [0105] The attachment structure 11 does not include a bar with an outer thread but has an inner thread. Generally, the attachment structure may be formed in any suitable manner. As alternatives to an (outer or possibly inner) thread, the attachment structure could also be shaped for a bayonet coupling, a snap-on connection, etc. [0106] The proximal face 13 is not perpendicular to the proximodistal axis but is slightly sloped.

[0107] These features are independent of each other, and the process described hereinafter is independent of them. The process may apply to all embodiments of connectors referred to in this text.

[0108] For anchoring, a sonotrode 6 having an axial channel 61 for accommodating the attachment structure 11 and having an outcoupling face adapted to the proximal face 13 of the connector presses the connector against the first object, with the anchoring skirt 15 in physical contact with the first object, while mechanical vibrations are coupled into the connector by the sonotrode. This is done until thermoplastic material of the first object in contact with the connector becomes flowable and by the pressing force is caused to flow relative to the connector, see arrows in FIG. 7. After the mechanical energy input by the mechanical vibrations stops, the sonotrode 6 may be used to apply some after pressure, for example until re-solidification of the flowable portions has set in to at least some extent.

[0109] FIG. 8 shows the connector anchored after the process, with the thermoplastic material after re-solidification securing the connector to the first object in a positive-fit manner. Especially, material flown into the outer pocket 17 secures the connector against axial movements towards proximally. The (re-solidified) flow portion 8 of the thermoplastic material includes material that has flown back to proximally of the proximal surface (level 30/FIGS. 2 and 4) of the first object.

[0110] FIG. 9 shows an embodiment with a plate portion 12 and a plurality of anchoring skirts 15, each extending around an anchoring skirt axis 22. The attachment structure (not visible in FIG. 9) may be, similarly as in the embodiments described hereinbefore, symmetrical about the central proximodistal axis 20.

[0111] Whereas the embodiments shown in the figures have attachment structures, alternatively or in addition thereto the connector could also have an integrated interaction element being a sensor and/or actuator.

[0112] The method of anchoring the connector relative to the first object may include coupling the mechanical energy into the connector in the form of vibration energy, as described referring to FIG. 7. Such vibration may be longitudinal vibration. Alternatively, the vibration may include rotational vibration, wherein the connector vibrates by rotating back and forth around the proximodistal axis. As yet another alternative, the mechanical energy could be mechanical rotation energy, wherein the connector is caused to be subject to a rotational movement around the proximodistal axis, relative to the first object. Of the above described embodiments, with the exception of the connectors of FIG. 5 and of FIG. 9, all embodiments are potentially suited for this variant of the anchoring process.

[0113] FIG. 10 shows a partial section of a connector 2 anchored with respect to a first object 1. The plate portion 12 has a circumferential distal protrusion 24 that forms a chamber 23 for the thermoplastic material that has flown back towards proximally. Thereby, the stability against tilting forces may be enhanced by at least one of: [0114] The circumferential distal protrusion itself abutting against the first object after anchoring; [0115] The thermoplastic material having flown as far as the plate portion thus, for example, essentially filling the chamber so that after re-solidification of the thermoplastic material the plate portion abuts against thermoplastic material.

[0116] FIG. 11 shows an embodiment of a connector that is distinct from the embodiments previously described in that the anchoring skirt 15 is does not extend around a full circumference but is interrupted to have a plurality of anchoring skirt portions 51, 52, 53, 54.

[0117] Independently of this feature, FIG. 11 also shows optional indentations 25, 26 as described hereinafter.

[0118] FIG. 12, schematically showing a partial section of a connector, illustrates possible undercut structures that may add to the stability of the anchoring. First indentations 25, being open towards the outer pocket, are arranged on a radial outer portion of the anchoring skirt 15. Second indentations 26, open towards the inner pocket, are arranged on a radial inner portion of the anchoring skirt 15. Third indentations 27 are arranged around the flow hole. At least the second and third indentations may be undercut with respect to axial directions.

[0119] Generally, a connector can have first indentations, second indentations and/or third indentations, i.e., these structures are possibly independent of each other. Also, in addition or as an alternative to the indentations other structures, such as protrusions, (circumferential ridges for example), roughness, etc., may be present.

[0120] FIG. 13 shows a holding mechanism for holding the connector 2 relative to the sonotrode 6. In the depicted embodiment, the holding mechanism includes a resilient element 63 arranged in an axial position constituting a vibrational node.

[0121] FIG. 13 further illustrates, independently of the holding mechanism, a coupling element interposed between sonotrode 6 and incoupling surface, for example a sheet of (for example multi-layered) paper or cardboard. Such sheet may also be used for being provisionally mounting a plurality of connectors in a, for example, industrial process that involves anchoring many connectors.

[0122] FIG. 14 shows the option of coupling mechanical vibration energy into the system by causing a sonotrode 6 to impinge on the first object from the opposing, distal side while the connector 2 and the first object 1 are held against each other. This option may especially be attractive if the distal surface of the first object does not have to have a perfect quality after the process but for example is concealed in the final article to be produced. However, using appropriate measures it may also be possible to use this option in cases where the distal surface of the first object is, for example, a class A surface—for example a protective foil between the first object and the sonotrode. In fact, it has been shown experimentally that in some situations this option of coupling the mechanical energy into the assembly from a distal side, by a sonotrode impinging on the first object instead of on the connector, is even more secure in terms of making an anchoring without any marks on the distal first object surface possible. In embodiments in which the connector serves for securing a further, third object to the first object 1, the configuration with energy input from the distal side may have the advantage that the connector(s) can be pre-mounted on the third object 3, prior to the anchoring process. For example, if the connection between the third object 3 and the connector is a screwed connection, multiple connectors 2 can be directly screwed into/onto the respective anchoring locations of the third object, this not being possible any more after the connectors have been anchored. FIG. 14 illustrates the third object 3 with a fastening hole having an inner thread and with the threaded bar 11 of the connector screwed into the fastening hole.

[0123] Other holding methods than holding by a screwed connection are possible also. Generally, in many embodiments holding should ensure directional stability of the connector with respect to the tool or third object that holds it and a good coupling between the connector and the tool/third object.

[0124] FIG. 15 depicts a connector 10 that, in contrast to the previously described embodiments, has the following properties: [0125] The flow hole 19 is a through hole extending through the entire attachment structure 11 to the proximal end of the connector. [0126] The flow hole has a restriction 192 whereby, like in the embodiments of FIGS. 4 and 12, an undercut with respect to axial directions is formed. Hence, thermoplastic material that during the anchoring process flows back into the flow hole beyond the restriction 192 after re-solidification contributes to the anchoring by causing a positive fit connection.

[0127] These two features can be realized independent of each other. Especially, a flow hole 19 that is not a through hole but a blind hole open only at the distal mouth 191 can be undercut, too. Similarly, it is possible to have a flow hole 19 that is a through hole but that is not undercut.

[0128] In the variant shown in FIG. 16, the restriction (neck) of the flow hole 19 in contrast to FIG. 15 is not continuous but is stepped so that a proximally facing shoulder is formed within the flow hole.

[0129] Generally, the restriction (neck) of the flow hole can be adjacent the distal mouth 191. It would also be possible to make a restriction more proximally, in addition or as an alternative to the neck adjacent the distal mouth.

[0130] Other structures that cause a positive fit with respect to axial directions would be possible also, including for example a series of circumferential ridges, an arrangement of inwardly facing humps, or an inner thread.

[0131] A further optional feature of both, the embodiment of FIG. 15 and of FIG. 16 (which feature is again independent of the other features of these embodiments) is that the distal edge 16 is relatively sharp in that the angle 180°-α-β is acute and is, for example, less than 60°. In the shown embodiment, the connector has adjacent the proximally outer face 171 of the anchoring skirt a steeper, for example cylindrical, surface.

[0132] In the embodiment shown in FIG. 17, for anchoring in addition to the elements described hereinbefore a washer 71 is used. The washer in this embodiment is of the same thermoplastic material as the first object 1 or is of a different thermoplastic material that however is weldable to the material of the first object.

[0133] For anchoring, the mechanical vibrations are coupled into the connector via the washer that abuts against the proximal face 13 and is pressed thereagainst by the vibrating sonotrode. This will cause, initiated by the sharp edge 16 at the distal end serving as energy director the local liquefaction of thermoplastic material of the first object 1 and the effects described hereinbefore referring to FIGS. 7 and 8. When during the process and after the anchoring skirt 15 has penetrated into the first object the distal face 14 is pressed against the surface of the first object the mechanical resistance increases. In the embodiment shown in FIG. 17 the pressing force and the vibrations are nevertheless maintained until material of the washer 71 becomes flowable. This may be continued until material of the washer and of the first object 1 are welded to each other (weld 72) around a periphery of the plate portion 12, as shown in FIG. 18. This will in addition to making a contribution to the fastening strength also cause the interface between the plate portion and the first object to be sealed.

[0134] FIG. 18 also illustrates a part of the flow portion 8 in the flow hole 19 proximally of the restriction 192.

[0135] The-optional-use of a washer 71, for example leading to a weld around a periphery of the plate portion 15, is an option for all embodiments of the present invention and is not restricted to the particular shape and features of the connector illustrated in FIGS. 17 and 18.

[0136] An embodiment of a connector 10 of a non-homogeneous material composition is shown in FIG. 19. In this embodiment, the connector has a metallic body forming the attachment structure 11 and the anchoring skirt 15 and further has a thermoplastic plate portion 12 firmly axially coupled (in FIG. 19 by an outer thread of the metallic body) to the metallic body. The thermoplastic plate portion may be of a same thermoplastic material as the first object or of an other thermoplastic material weldable to the thermoplastic material of the first object.

[0137] The anchoring process for such a hybrid connector 10 is carried out similar to the process with the connectors described hereinbefore. During an initial phase when the vibration is coupled into the assembly via the proximal face 13 thermoplastic material of the first object in contact with the relatively sharp edge is liquefied due to the energy directing properties. As soon as the mechanical resistance becomes higher, material of the thermoplastic plate portion is liquefied also, possibly resulting in a weld between the plate portion and the first object. Advantages of this weld may be comparable to the advantages of the weld with a thermoplastic washer, as illustrated in FIG. 18, though without the additional anchoring strength caused by the metallic plate portion of the embodiment of FIG. 18. During the anchoring process, especially towards its end, the connection between the metallic body and the thermoplastic plate portion may loosen to some extent because of thermoplastic material of the plate portion becoming flowable at the interface to the metallic body. After re-solidification such connection will become tight again.

[0138] FIGS. 20 and 21 illustrate a further optional principle: The sonotrode may have an exchangeable sonotrode tip 69 that forms the distal outcoupling face (on the right hand side in FIGS. 19 and 20) and that has the axial channel 61 for accommodating the attachment structure. The axial channel 61 may be a blind hole open towards distally (FIG. 19) or an axially running through hole (FIG. 20).

[0139] Such sonotrode tip 36 may be mountable on a for example generic sonotrode body, for example via a sonotrode tip thread 68.