Connector element and method of bonding such a connector element to a substrate

Abstract

A connector element (1) for bonding to a substrate by pressing the connector element (1) and the substrate together and mechanically energizing the connector element (1) and the substrate relative to each other while pressed together, comprising a base portion (2) having a distal surface (23) and a plurality of protrusions (3) extending distally from the distal surface (23) of the base portion (2). The protrusions (3) comprise a thermoplastic material configured to liquefy when the connector element (1) is pressed onto the substrate and mechanically energized. The connector elements (4) comprise a thermoplastic material configured to liquefy when the connector element (1) is pressured onto the substrate and mechanically energized. Each connector element (4) connects two adjacent ones of the protrusions (3).

Description

Technical Field

[0001] The present invention relates to connector elements and methods for bonding such connector elements to compressible substrates.

[0002] More specifically, the present invention relates to a connector element for bonding to a substrate by pressing the connector element and the substrate together and mechanically actuating them relative to each other during pressing, wherein the connector element includes a base portion having a distal surface and a plurality of protrusions extending distally from the distal surface of the base portion, and wherein the plurality of protrusions comprises a thermoplastic material configured to liquefy when the connector element is pressed onto the substrate and mechanically actuated. Furthermore, the present invention relates to a method of bonding such a connector element. This connector element and method can be used in mechanical engineering applications in various industries such as the construction and automotive industries, and with a wide range of different substrate materials, such as compressible lightweight materials. Background Technology

[0003] Connectors in lightweight materials—such as hollow core boards made of different types of materials (e.g., wood, plastics like polypropylene), sandwich materials made of different types of materials (e.g., wood, plastics like polypropylene), especially foam materials such as expanded polypropylene or polyurethane, metal foam, and different types of thermoplastics or other plastic materials reinforced with or without carbon and / or glass fiber, as well as fiber and braided materials—are generally becoming increasingly important in industries such as automotive, aerospace, and construction. Traditional methods such as gluing, threading, nailing, and riveting pose challenges to the production speed, quality, and weight of parts. Gluing is very time-consuming because the glue needs to dry and the bonding quality is difficult to control. Depending on the density of the base material, the bonding of conventional mechanical connectors (such as screws, nails, and rivets) can damage the base material and result in very low bond strength.

[0004] WO2018 / 172385A1 discloses a method for joining two objects together, wherein the first object is a connector made of thermoplastic material, comprising a plurality of distally projecting tips, and the second object comprises a region having a low density. During the joining process, the thermoplastic material of the first object is liquefied by applying ultrasound, and the first object is pressed against the second object to alter the compressive strength of the low-density region, which facilitates the liquefaction of the thermoplastic material of the first object.

[0005] When it comes to joining objects together by liquefying objects with pointed or protruding tips, a challenge may be providing sufficient robustness in the tip while simultaneously achieving adequate penetration of the other object. In particular, when considerable pressure is involved, the tip should be designed to be both sufficiently thick or bulky to be strong enough, and sufficiently thin or slender to penetrate the other object.

[0006] Therefore, there is a need for a connector element that provides stability during the bonding process and provides an enhanced bonding result by preventing the protrusions from collapsing during bonding. Summary of the Invention

[0007] According to the present invention, this requirement is addressed by a connector element as described below and a method for bonding such a connector element to a compressible substrate having a proximal surface as described below. Preferred embodiments are the subject of the following description.

[0008] On one hand, the present invention is a connector element for bonding to a substrate by pressing the connector element and the substrate together and mechanically energizing the connector element and the substrate relative to each other when pressed together. The substrate can be, in particular, a lightweight material, such as a thermoplastic material, and more specifically, a foamed plastic material. For example, the substrate can be made of or contain foamed polypropylene (EPP), foamed polyethylene (PE), foamed polyvinyl chloride (PVC), foamed polystyrene (EPS), extruded polystyrene (XPS), foamed polylactic acid (PLA), or other foams comprising PE, PVC, or PLA. Another example of the substrate is a hollow core board or sandwich material made at least in part of thermoplastic materials such as PP, PE, PVC, PLA, extruded polypropylene (XPP), polyamide (PA), polyethylene terephthalate (PET), polyphenylene ether (PPE), or, in particular, mixtures of the aforementioned thermoplastic materials.

[0009] The connector element includes a base portion having a distal surface and a plurality of protrusions extending distally from the distal surface of the base portion. The protrusions comprise a thermoplastic material configured to liquefy when the connector element is pressed against a substrate and mechanically actuated. Furthermore, the connector element includes connecting members comprising a thermoplastic material configured to liquefy when the connector element is pressed against a substrate and mechanically actuated. Each connecting member connects at least two adjacent protrusions.

[0010] In the context of this invention, the term "connector element" refers to a structure that can be connected to a substrate. It can be a connector capable of being pressed onto a substrate via a tool and mechanically withdrawn by the same or different or additional tools while the connector element is pressed onto the substrate, thereby partially liquefying to achieve a positive-fit connection and / or integral bonding such as welding to the substrate. The connector element can be coupled to the substrate to reinforce the substrate material or to attach an object to the substrate. In the case of reinforcing the substrate, the connector element can provide different connecting elements for attaching, securing, or coupling to the connector element. These connecting elements can be concave connecting elements, such as channels or holes for screw mounting. The connector element can enhance threaded connections. In the case of connecting an object to the substrate, the connector element can be used to attach, secure, or couple a second object to the substrate by encapsulating the corresponding object, by piercing the object, or by welding to the object in a further process step. The connector element can be equipped with convex connecting structures for mounting objects, for example, by clamping.

[0011] The base portion of the connector element can be cylindrical or disc-shaped. It can have rotationally symmetric and rotationally asymmetric cross-sections. For example, the cross-section can be circular, square, rectangular, polygonal, triangular, or an undefined geometry, meaning a cross-section of a single shape. The connector element can also be conical.

[0012] According to an embodiment of the invention, the base portion includes a proximal side and a distal side, which form a proximal surface and a distal surface arranged along an axis (i.e., a proximal-distal axis).

[0013] The term "distal" refers to the direction toward the substrate in the intended application or use of the connector element. It can refer to both a narrow direction and a relative position. For example, the distal surface of a base portion is the section of the base portion oriented toward the substrate when bonded to it. Similarly, the term "proximal" refers to the opposite direction or relative position to the distal side.

[0014] In embodiments, the distal surface is intended to be bonded to or attached to the substrate, while the proximal surface may be intended to provide a connecting element, such as a concave or convex portion for connection, or to serve as an attachment surface or proximal coupling structure for pressing the connector element and the substrate together and mechanically actuating them. The base portion may include a flat portion that is not equipped with a protrusion or any other structure projecting in the distal direction. In embodiments, the tool suitable for the connector element is an ultrasonic generator. In other embodiments, the tool may be an automatic screwdriver or wrench (automated). In one embodiment, the base portion is composed of or at least contains a thermoplastic material.

[0015] The distal surface of the base portion includes a plurality of distally extending protrusions. These protrusions comprise a thermoplastic material configured to liquefy when the connector element is pressed against the substrate and mechanically aroused, for example, by a tool such as an ultrasonic generator. For particularly robust connections, the protrusions may be configured to penetrate the substrate during bonding. To achieve this, they may include tips, edges, or other cut ends. This allows the connector to be securely anchored to the substrate.

[0016] The thermoplastic material in the context of this invention can be a material, or at least a component of such a material, capable of melting, becoming flowable, or liquefied by mechanical excitation and simultaneous interaction with a substrate. For example, the thermoplastic material can be configured to liquefy when a connector element is pressed against a substrate and vibrated, rotated, and / or oscillated. In this way, pressure and friction can generate sufficient heat to liquefy the thermoplastic material at least partially or locally. Therefore, the liquefaction interaction between the connector element and the substrate is typically caused by friction resulting from mechanical excitation of the connector element, such as heating the thermoplastic material through mechanical vibration or rotation. As a result, the thermoplastic material softens, melts, or becomes flowable. In embodiments of the invention, a prerequisite for the process described herein is that the connector element and the substrate are exposed to pressure. This pressure can be established by a tool that presses the connector element into or onto the substrate, with the substrate exerting a certain counter-pressure on it. In embodiments, the substrate can be pressed against the connector element by a tool, for example, via lateral clamping or similar means. To establish / form / accumulate friction, some press-fit condition needs to be established.

[0017] The thermoplastic material suitable for the method according to the invention is solid at room temperature or at the temperature at which the bonding process takes place. It preferably comprises a polymeric phase (especially based on C, P, S, or Si chains) that transforms from a solid to a liquid or flowable state above a critical temperature, for example by melting, and reverts to a solid material upon cooling below the critical temperature, for example by crystallization, whereby the viscosity of the solid phase is several orders of magnitude (at least three orders of magnitude) higher than that of the liquid phase. The thermoplastic material may generally contain a polymeric component that is not covalently crosslinked or crosslinked in a manner in which the crosslinking bonds reversibly open upon heating to or above the melting point range. The polymeric material may also contain fillers, such as fibers or particles of the material, which are not thermoplastic or have a thermoplasticity including a melting point range much higher than that of the base polymer.

[0018] Specific examples of suitable thermoplastic materials include polyetherketone (PEEK), polyesters such as polybutylene terephthalate (PBT) or polyethylene terephthalate (PET), polyetherimide, polyamides such as polyamide 12, polyamide 11, polyamide 6 or polyamide 66, polymethyl methacrylate (PMMA), polyoxymethylene or polycarbonate polyurethane, polycarbonate or polyester carbonate or acrylonitrile butadiene styrene (ABS), acrylate-styrene-acrylonitrile (ASA), styrene-acrylonitrile, polyvinyl chloride (PVC), polyethylene, polypropylene and polystyrene or copolymers or mixtures thereof. In a particularly preferred embodiment, the thermoplastic material comprising the connector element is based on polypropylene or polyethylene or polystyrene or polyvinyl chloride or polylactic acid.

[0019] Advantageously, the thermoplastic material of the protrusion is the same as that of the connecting member. Furthermore, the protrusion and the connecting member may be composed of the same thermoplastic material. In one embodiment, the base portion is also composed of or at least contains a thermoplastic material.

[0020] The thermoplastic material can be reinforced. Advantageously, it can be, for example, fiber-reinforced polypropylene. The fibers included can be, for example, glass fibers or carbon fibers. In an advantageous embodiment, the connector element is integrally formed. Therefore, it can consist of a single thermoplastic material.

[0021] According to the invention, the provision of connecting members allows for the stabilization of the protrusion during the bonding process. In particular, they prevent damage to the protrusion when pressed against the substrate and mechanically actuated. Therefore, the connecting members allow the protrusion to penetrate the substrate relatively smoothly. This allows for the secure anchoring of the connector element to the substrate. Furthermore, the connecting members allow for the protrusion to be designed to be relatively thin, which also results in more efficient penetration into the substrate. This relatively thin but still stable protrusion is also beneficial for bonding the connector element to a relatively soft substrate.

[0022] Furthermore, connecting members can be used to guide and improve the alignment of connector elements during the bonding process. Moreover, connecting members can be used to cut through portions of the substrate material. This can be facilitated by equipping at least a portion of the connecting member with a cutting structure such as a sharp edge.

[0023] Because the connecting elements comprise a thermoplastic material configured to liquefy during bonding, they can enhance the connection between the connector element and the substrate after re-curing. In particular, this can be achieved by the connecting elements increasing the bonding surface of the connector element. Similarly, in embodiments of the invention, the number of protrusions can be reduced without compromising the achieved connection strength, which also allows for a reduction in the weight of the connector element. Connector elements with relatively small diameters and relatively long protrusions are feasible because the connecting elements prevent the protrusions from unraveling or breaking. Generally, the cross-section of the protrusions therefore does not need to be too large.

[0024] In a preferred embodiment, the connecting member is membrane-like. This connecting member is designed to be thin-walled and may also be referred to as a membrane or ribbed membrane. Such a membrane can provide sufficient stability to the protrusion through a relatively small or thin and non-interfering structure. For example, the connecting member can be more than ten times thinner than the protrusion.

[0025] Preferably, the protrusions of the connector elements have substantially the same protrusion length, and each connector element connects at least two adjacent protrusions along at least one-quarter of the protrusion length, preferably along at least one-third of the protrusion length, more preferably along at least half of the protrusion length, or along at least two-thirds of the protrusion length. This configuration of the connector elements allows for sufficient stability of the protrusions while simultaneously allowing for a relatively thin connector element design.

[0026] However, it is not generally excluded that in certain embodiments the connecting member may exceed the length of the protrusion. This could be for various reasons, such as cutting into the substrate material and thereby increasing the accessible surface of open holes for example to enhance the bond, or facilitating deep anchoring / bonding by enabling the connector element to be further inserted into the substrate.

[0027] Preferably, the connecting member protrudes from the distal surface of the base portion. This allows the connecting member to be integral with the base portion, i.e., the connecting member can extend into the distal surface of the base portion. This makes the connecting member sufficiently robust to withstand the relatively high shear forces that the connector elements may experience. For example, such shear forces can be compensated for by variations in the cross-section of the connecting member along its axial or proximal-distal length. For example, the cross-section of the connecting member may be larger at the interface with the base portion or its distal surface, and smaller at its very distal end where a sharp or cutting edge can be formed. Furthermore, the connecting member may be inclined relative to the distal surface and / or relative to at least two adjacent protrusions. In different embodiments, the width of the connecting member may take different forms. The width of the connecting member may be the width of the connecting member between at least two adjacent protrusions they connect. Generally, the connecting member can be adapted to the position, inclination, and size of the protrusions. At the interface with the respective protrusion, the connecting member may be thicker than it is for the rest of its width. The connecting member may be bent in a recessed or convex manner.

[0028] Preferably, the base portion has a circumference and the protrusions are arranged along the circumference of the base portion. In this context, the circumference can refer to the radially outer surface of the base portion. In embodiments of a disc-shaped base portion, the circumference may include an edge of the base portion. Such an edge may be a radially or outwardly extending surface. In embodiments of a cylindrical base portion, the circumference may include an outer casing region. The circumferential arrangement of the protrusions can mean that the protrusions are located near the circumference on the distal surface. For example, they may be located in a circle or straight line parallel to and close to the edge or casing.

[0029] In this way, the base portion can be bonded to the substrate at or near its edge. This allows for a relatively high torque resistance connection. Moreover, since the mating surface is largest along the outermost radial edge / circumference of the connector element, a wide and robust bond can be achieved between the connector element and the substrate.

[0030] Preferably, the base portion of the connector element includes a disk portion having a distal surface. Specifically, the entire base portion may be disk-shaped, or more specifically, have a disk shape. In such embodiments, the protrusions may be arranged circularly along the circumference of the base portion. In embodiments where the base portion does not have a circular shape, the protrusions are arranged in the geometry of the base portion's cross-section; for example, a rectangular cross-section of the substrate results in the protrusions being arranged along a rectangular circumference of the base portion.

[0031] Preferably, each protrusion includes a groove extending distally along the protrusion. Such grooves in the protrusion can facilitate melting or liquefaction of the protrusion. In particular, when the connector element is exposed to mechanical vibration or oscillation during bonding to the substrate, the groove can provide additional frictional surface, allowing the material of the connector element to liquefy more quickly. Furthermore, the groove can act as an energy conductor, directing the energy of mechanical vibration or oscillation. In this way, mechanical energy accumulates in specific areas, allowing the material of the protrusion to liquefy more quickly under mechanical excitation. The groove is arranged on the portion of the protrusion that will come into contact with the substrate material during bonding. Protrusions arranged circumferentially along the base portion of the connector element may be provided with grooves as described herein.

[0032] Therefore, the groove preferably extends along the substantially complete length of the protrusion. This configuration makes the groove particularly effective in guiding mechanical energy. The groove can extend into the circumference of the base portion, i.e., axially or proximally along a portion of the outer casing area of ​​the connector element. In some embodiments, it may also be advantageous for some portions of the protrusion not to be grooved, for example, the distal third of the axial or proximal protrusion length, or only 5-20% of the axial or proximal length (distal or proximal, or in the middle section of the axial or proximal protrusion length arranged between the proximal and distal ends of the protrusion). Typically, 50% of the axial or proximal protrusion length is grooved to achieve the desired effect.

[0033] It is not excluded that in some embodiments of the connector element, the grooves extending distally exist only on some protrusions rather than on every protrusion. Moreover, in some embodiments, it may be advantageous to provide grooves on protrusions that are not arranged circumferentially along the base portion of the connector element.

[0034] Preferably, each protrusion has a distal puncture end. This puncture end can be formed as a tip, a cutting edge, etc. In particular, the puncture end can be configured to puncture the substrate when the connector element is pressed against the substrate. In this way, the protrusion can be firmly anchored to the substrate. Another purpose may be energy guidance, i.e., acting as an energy conductor. The puncture end can be configured to be particularly suitable for the type of substrate involved.

[0035] Preferably, the connector element includes a central dome-shaped portion extending distally from the distal surface of the base portion, wherein the central dome-shaped portion is surrounded by a protrusion. In some embodiments, particularly depending on the cross-section of the base portion, the central dome-shaped portion need not be geometrically centered. Instead, it may be centered relative to the protrusion, i.e., surrounded by the protrusion.

[0036] The central dome-shaped portion may be longer in the axial direction than the rest of the protruding portions of the connector element. Depending on the design of the central dome-shaped portion, its axial length allows it to function as a guide in the initial stages of the mating process. However, in some embodiments, the central dome-shaped portion may also be shorter in the axial direction or have the same axial length as the protrusions.

[0037] The central dome-shaped portion preferably has teeth extending distally. When pressed against a substrate, such teeth help the dome-shaped portion penetrate the substrate. Each tooth may include a groove extending distally along that tooth. The grooves may also extend substantially along the entire length of the tooth. The purpose of the grooves is to reduce the amount of material, thereby reducing weight, and to create energy conductors between the grooves. Furthermore, the grooves can help guide energy; for example, areas without grooves may form protrusions that can act as energy conductors.

[0038] Each tooth preferably has a distal puncture end. This puncture end can be a tip, a cutting edge, etc. By equipping the tooth with a puncture end, it can effectively penetrate the substrate.

[0039] The central dome-shaped portion preferably has a cavity that opens at the proximal end of the base portion. This cavity, accessible from the proximal end of the base portion, provides the functionality of the configured connector element. For example, this cavity can be a threaded channel, or—in a second step—it can be threaded via a self-tapping screw. Thus, after the connector element is configured and coupled to the substrate, a screw can be attached to the substrate via the connector element. In particular, a self-tapping screw with cutting threads for cutting thermoplastic materials can be used. In some embodiments, the cavity is closed or plugged at its distal end, for example, by teeth with or without a distal piercing end. This is to prevent liquefied material from filling or damaging the cavity during the bonding process. The cavity can also be a concave component, for example, a clamping or snap-fit ​​connection.

[0040] The central dome-shaped portion is preferably configured such that the cavity undergoes bonding between the connector element and the substrate. This can be achieved by providing sidewalls of the central dome-shaped portion with a thickness greater than that of the protrusion. Another way to achieve this effect is to design the teeth and grooves in a way that provides stability during bonding, so that the central dome-shaped portion does not collapse due to the mechanical excitation experienced by the connector element during bonding. One example is a radial protrusion that liquefies first during bonding.

[0041] Preferably, the distal surface of the base portion has a flat section. Specifically, the flat section can be implemented by omitting any protrusions and ultimately omitting teeth or similar structures. This flat section abuts against the proximal surface of the substrate, allowing for effective compression of the substrate. Furthermore, the flat section can serve as a stop surface during the bonding process. The flat section is typically flat, planar, or smooth, but it may also include grooves or other structures or may have a slightly irregular shape.

[0042] The flat section is preferably the main part of the distal surface of the base portion. A smaller portion of the distal surface of the base portion is covered by a protrusion including connecting members and (if present) a central dome-shaped portion. This allows for effective compression of the substrate, which can be particularly advantageous if a relatively soft substrate is involved.

[0043] Preferably, the base portion is equipped with a proximal coupling structure. This coupling structure can interact with a corresponding structure of the tool (e.g., an ultrasonic generator). For example, the coupling structure can be implemented as a convex or concave portion of the connector. With the aid of the coupling structure, the connector element can be effectively held or manipulated by the tool.

[0044] Preferably, the cross-section of the protrusion decreases in the distal direction. The cross-section of the protrusion may be the same or different for all protrusions. This reduced cross-section allows the protrusions to taper gradually, enabling them to effectively penetrate the substrate.

[0045] Preferably, the protrusion is arranged near the periphery of the base. The periphery may be substantially equal to the outer surface area of ​​the base portion. This arrangement allows the base portion to be bonded to the substrate at or near its edge. This achieves a wide and strong bond between the connector element and the substrate because the bonding surface is largest along the outermost radial edge / circumference of the connector element. This arrangement may be particularly advantageous in embodiments with a relatively large base portion.

[0046] Thus, at least some of the protrusions preferably have an outer side associated with the periphery of the base, and at least some of the outer sides of the protrusions are preferably inclined. If the base portion is substantially disc-shaped, the outer side is typically the radial end side or face of the protrusion. The radial outer side of the protrusion can be an axial continuation of the outer cover region of the base portion.

[0047] Preferably, the base portion has a proximal flange portion and a distal cylindrical portion. The proximal flange portion typically has a larger cross-section than the distal cylindrical portion. The shape of the cross-section can vary; for example, the proximal flange portion may be circular while the cylindrical portion has a rectangular cross-section, or both, and both the proximal flange portion and the cylindrical portion may have rectangular cross-sections or even other cross-sections. This flange portion allows for a larger proximal side. The flange portion can act as a stop surface during engagement.

[0048] The connection between the proximal flange portion and the cylindrical portion can be continuous, meaning the cross-section of the proximal flange portion decreases in the distal direction until it has the same diameter as the cylindrical portion. This is also possible for embodiments where the cross-sectional shapes of the proximal flange portion and the cylindrical portion are different. This allows the connector element to be smoothly inserted and bonded to the substrate.

[0049] Furthermore, the base portion preferably includes ribs connecting the flange portion and the cylindrical portion. Such ribs can stabilize the flange portion relative to the cylindrical portion. Therefore, the ribs preferably extend from the distal end of the flange portion to the outer surface of the cylindrical portion. Ribs arranged on the distal surface of the proximal flange portion can also serve as energy guides to provide proper bonding between the flange portion and the proximal surface of the substrate material or into the proximal surface of the substrate material.

[0050] On the other hand, the present invention is a method for bonding a connector element as described above to a compressible substrate having a proximal surface. This method may also be referred to as a bonding process.

[0051] The method includes the following steps: (i) arranging a connector element on a substrate such that a protrusion of the connector element extends toward a proximal surface of the substrate; (ii) applying pressure and mechanical excitation such that the protrusion of the connector element penetrates the substrate and liquefies at least a portion of the thermoplastic material of the protrusion and the thermoplastic material of the connecting member; and (iii) stopping the mechanical excitation such that the thermoplastic material of the protrusion and the thermoplastic material of the connecting member re-solidifies.

[0052] Pressure and mechanical excitation can be applied to the connector element and / or substrate. Advantageously, pressure and mechanical excitation are applied by at least one tool. In a preferred embodiment of the invention, at least one tool is an ultrasonic generator that applies pressure and mechanical excitation to the connector element and / or compressible substrate. Alternatively, pressure can be applied proximally by another tool disposed next to or below (far-side) the ultrasonic generator and pressing against it.

[0053] In the preferred embodiment, the mechanical excitation is mechanical vibration or oscillation, preferably at a frequency between 2 and 200 kHz. More preferably, the frequency of the ultrasonic vibration is between 10 and 100 kHz, or between 20 and 40 kHz. The vibration energy can be 0.2 to 20 W per square millimeter of active surface. The vibrating tool or ultrasonic generator is, for example, designed such that its contact surface oscillates primarily in the direction of the tool axis (longitudinal vibration) and the amplitude is between 1 and 100 μm, preferably about 50 to 80 μm. This preferred vibration can be generated by an ultrasonic device, as is known from ultrasonic welding.

[0054] In an advantageous arrangement, the substrate is held and the connector element is pressed against the substrate and mechanically aroused. As described above, the mechanical arousal can specifically include oscillation or vibration. Thus, oscillation or vibration can be provided along the protrusion or at an angle thereto. At least a portion of the thermoplastic material of the protrusion and the thermoplastic material of the connector element can be 5% or even less, or more. Depending on the embodiment of the connector element, the connector element may penetrate the substrate during the method steps of applying pressure and mechanical arousal.

[0055] In the context of this invention, the term "compressible substrate" refers to a substrate whose compressive strength can be altered by applying pressure. Compressive strength refers to the maximum force per square millimeter generated by the region before it is displaced, which in this context means before the compressible substrate is compressed and its compressive strength increases. For example, compressive strength can correspond to stress as measured in a stress-strain test.

[0056] The compressible substrate material is preferably a foam material, such as EPP, EPS, XPS, XPP, PA, PET, PPE, PE foam, PVC foam, PLA foam, and any polymer blends of these materials. The thermoplastic material suitable for the connector element according to the method of the invention needs to be compatible (weldable) with the material of the compressible substrate. For example, a substrate containing EPP works best with connector elements containing PP-based materials, a substrate containing EPS works best with connector elements containing polystyrene-based materials, a substrate containing XPS works best with connector elements containing polystyrene-based materials, PE foam serving as a substrate works best with connector elements containing PE-based materials, PVC foam serving as a substrate works best with connector elements containing polyvinyl chloride materials, and PLA foam serving as a substrate works best with connector elements containing polylactic acid-based materials.

[0057] In a preferred embodiment, the connector element is pressed into the substrate in the portion of the substrate where the connector element is arranged. This pressing allows the critical density and / or critical compressive strength required to liquefy the plastic material to be generated by mechanical excitation.

[0058] Preferably, when pressure is applied to the connector element, the substrate density in the portion of the substrate where the connector element is arranged increases until it is high enough to allow the protrusion to penetrate the substrate and to allow the thermoplastic material of the protrusion and the thermoplastic material of the connector element to liquefy.

[0059] Preferably, the method includes a step of stopping the application of pressure only after the thermoplastic material of the protrusion and the thermoplastic material of the connecting member have re-cured. This may be important because only after the thermoplastic material has re-cured can the achieved bond overcome the springback effect of the compressible material caused by the release of pressure on the compressible material. Since the goal may be to achieve a near-flush connection, i.e., the proximal surface of the connector element is flush with the proximal surface of the substrate material, it is important that the connector element is not pushed into the proximal direction after the bonding process.

[0060] The process can be automated. Attached Figure Description

[0061] The connector element and the method according to the invention are described in more detail below with reference to exemplary embodiments and the accompanying drawings, in which: Figure 1 A perspective view of the proximal side of a first embodiment of a connector element according to the present invention is shown; Figure 2 It shows Figure 1 A perspective view of the distal side of the connector element; Figure 3 It shows Figure 1 A cross-sectional view of the connector component; Figure 4 A perspective view of the distal side of a second embodiment of a connector element according to the present invention is shown; Figure 5 A perspective view of the distal side of a third embodiment of a connector element according to the present invention is shown; Figure 6 A fourth embodiment of the connector element according to the present invention is shown; Figure 7 A fifth embodiment of the connector element according to the invention is shown; and Figure 8 This is a flowchart of an embodiment of the method according to the present invention. Detailed Implementation

[0062] In the following description of the embodiments and the above description of the invention, the terms "proximal" and "distal" are used to refer to direction and position; that is, "proximal" is the mating side from which an operator or machine applies mechanical vibrations, while "distal" is the other side. The distal side relates to the direction and side of the connector element pointing towards the substrate when mated to it. Furthermore, there is a difference between axial and proximal / distal sides because in some embodiments, for example, protrusions or connecting members are not axially aligned but are inclined relative to the base portion.

[0063] In the following description, certain terms are used for convenience and are not intended to limit the invention. The terms “right,” “left,” “up,” “down,” “below,” and “above” refer to directions in the figures. Terminology includes explicitly mentioned terms and their derivatives, as well as terms with similar meanings. Furthermore, spatially related terms, such as “below,” “below,” “lower,” “above,” “upper,” “near,” “far,” etc., may be used to describe the relationship between one element or feature shown in the figures and another element or feature. In addition to the positions and orientations shown in the figures, these spatially relative terms are intended to cover different positions and orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as “below” or “below” other elements or features will then be “above” or “on” other elements or features. Thus, the exemplary term “below” can cover both above and below positions and orientations. The device may be oriented in other ways (rotated 90 degrees or otherwise oriented), and the spatially relative descriptive terms used herein shall be interpreted accordingly. Similarly, descriptions of movement along and around various axes include various specific device positions and orientations.

[0064] Figures 1 to 3 A first exemplary embodiment of a connector element 1 made of thermoplastic material according to the present invention is shown. (See also...) Figure 1 As can be seen, connector element 1 has a base portion 2, a plurality of protrusions 3, and a plurality of connecting members 4. Between every two adjacent protrusions 3, one of the connecting members 4 is arranged such that every two adjacent protrusions 3 are interconnected through one of the connecting members 4.

[0065] The base portion 2 is substantially disc-shaped and has a radial edge 21 forming its circumference and a flat proximal surface 22. At its center, there is an opening for a cavity 8 implemented in the proximal surface 22 of the base portion 2. The cross-section of the base portion 2 is circular.

[0066] The protrusion 3 has an axial groove 7 at its radially outer surface 16. In the depicted first embodiment, the length of the groove 7 corresponds to the substantially full length 31 of the protrusion (see...). Figure 3 The groove 7 extends into the distal portion of the base portion 2, but does not fully reach the distal end 9 of the protrusion 3. The outer surface 16 of the protrusion 3 is associated with the circumferential edge 21 of the base portion 2 and is slightly axially inclined, as in... Figure 3 As shown in the best example. At their distal ends, 9, the protrusions are equipped with puncture tips.

[0067] The connecting member 4 is implemented as a membrane spanning between the associated protrusions 3. (As in...) Figure 3As can be seen, they extend distally from the distal surface 23 of the base portion 2. Thus, they connect the two associated protrusions 3 along approximately two-thirds of the protrusion length 31. Although the outer sides 16 of the protrusions 3 are inclined, the connecting members are vertically aligned with respect to the distal surface 23 of the base portion 2. Furthermore, the connecting members 4 are rounded at their distal ends. Along their width, the connecting members do vary, with the portion near the protrusion being thicker than the middle portion. The middle portion is membranous. This is to ensure maximum stability of the protrusions 3.

[0068] At the center of the proximal end of the base portion 2, a cavity 8 opening of the central dome-shaped portion 10 is arranged. The central dome-shaped portion 10... Figure 2 It is shown in more detail below.

[0069] Figure 2 Connector element 1 is shown from a bottom or far-side perspective. Protrusion 3 is arranged along the circumference or edge 21 of base portion 2, i.e., at the outermost radial region of base portion 2. Thus, protrusion 3 is positioned along a circular line. A central dome-shaped portion 10 is formed at the center of the distal surface 23 of base portion 2. The dome-shaped portion 10 is surrounded by protrusion 3. Between the central dome-shaped portion 10 and the protrusion 3, a flat portion of the distal surface 23 of base portion 2 is visible. In the depicted embodiment, the flat portion is not a plane, but rather shows some minor unevenness, a result of manufacturing processes such as injection molding and milling.

[0070] The central dome-shaped portion 10 has six distally extending teeth 11 and indeed has axial grooves 12. At their distal ends, the teeth 11 are equipped with distal puncture ends 13. (As in...) Figure 3 As can be seen, the central dome-shaped portion 10 provides a cavity 8 that opens toward the proximal surface 22 of the base portion 2. The central dome-shaped portion 10 is longer in the axial direction than the protrusion 3, and the teeth 11 have a larger cross-section than the protrusion 3. Thus, the central dome-shaped portion 10 has higher rigidity than the protrusion 3, which allows the cavity 8 to be prevented from being broken or damaged during the engagement process.

[0071] As in Figure 3 As can be seen, the outer surface 16 of the protrusion 3 is inclined relative to the axis of the connector element 1. The circumferential edge 21 of the base portion 2 is not inclined, but extends axially. The cavity 8 is provided with a threaded groove accessible through an opening in the proximal surface 22 of the base portion 2.

[0072] The following applies to the description of further embodiments: To avoid repetition in the drawings and the description of various aspects and illustrative embodiments, it should be understood that many features are common to many aspects and embodiments. The omission of an aspect from the description or drawings does not mean that the aspect is missing from embodiments incorporating that aspect. Rather, the aspect may have been omitted for clarity and to avoid lengthy descriptions. If, for the sake of clarity, the drawings contain reference numerals not explained in the directly related parts of the specification, they refer to the preceding or following parts of the specification. Furthermore, for clarity, if reference numerals are not provided for all feature structures of a part in the drawings, reference is made to other drawings showing the same part. Identical reference numerals in two or more drawings denote identical or similar elements.

[0073] Figure 4 A second embodiment of the connector element 101 according to the invention is shown. The connector element 101 has a disc-shaped base portion 201, a plurality of protrusions 301, and membrane-like connecting members 401, each connecting member 401 connecting two adjacent protrusions 301 to each other. The second connector element 101 is implemented similarly to the first connector element 1, but has a smaller cross-section and therefore fewer protrusions 301. The central dome-shaped portion 1001 has teeth 1101 that do not extend axially over the protrusions 301 they surround. The outer sides 1601 of the protrusions 301 and the circumferential edges 2101 of the base portion 201 are sloped and do indeed form—say, an outer continuous line—so that the connector element 101 is smoothly positioned / bonded to the substrate, thereby achieving a flush connection point.

[0074] Figure 5 A third embodiment of the connector element 102 according to the present invention is shown. The connector element 102 has a base portion 202, a plurality of protrusions 302, and membrane connecting members 402, each connecting member 402 connecting two adjacent protrusions 302 to each other. The third connector element 102 is implemented similarly to the first connector element 1, but has a smaller cross-section with dimensions similar to the second connector element 101. Furthermore, the third connector element 102 has the same number of protrusions 302 as the second connector element 101 and has fewer protrusions 302 than the first connector element 1. However, unlike the base portions 2, 201 of the first and second embodiments, the base portion 202 has a proximal flange portion 1702 and a distal cylindrical portion 1802. These two portions are connected by a plurality of ribs 1902. The ribs 1902 extend from the proximal end of the flange portion 1702 to the outer surface of the cylindrical portion 1802.

[0075] exist Figure 6The image shows a fourth embodiment of the connector element 103 according to the invention. The connector element 103 has a disc-shaped base portion 203 with a circumferential edge 2103, a plurality of protrusions 303, and membrane-like connecting members 403, each connecting member 403 connecting two adjacent protrusions 303 to each other. The fourth connector element 103 is implemented similarly to the first connector element 1. However, unlike the first connector element 1, the fourth connector element 103 does not have a dome-shaped portion, but has a central hole 803 extending through the base portion 203.

[0076] Figure 7 A fifth embodiment of connector element 104 is shown. Connector element 104 has a base portion 204 with a circumferential edge 2104, a plurality of distally extending protrusions 304, and connecting members 404, each connecting member connecting two adjacent protrusions 304 to each other. The fifth connector element 104 is implemented similarly to the first connector element 1. However, it is integrated with yet another connector element 104 identical to the functional component 2504 (i.e., a component having a function different from or other than the function of bonding to the substrate). Functional component 2504 may be, for example, a hinge or a reinforcing component, but is not limited to these examples in the context of the invention. Basically, it can be any functional component used for bonding to a substrate in, for example, the transportation industry (e.g., automotive, packaging, aviation, marine, or aerospace). Integrating connector element 104 into functional component 2505 or similar components is advantageous because it simplifies the bonding process and reduces the number of components used and thus the number of processing steps.

[0077] In other embodiments, any one of the second to fourth connector elements 101, 102, 103 or similar connector elements may be integrated into functional component 2504 or similar functional component.

[0078] exist Figure 8 The figure shown illustrates the steps of an embodiment of the method according to the present invention. The first step is to provide a solid-state connector element 1 (e.g., as a bonding element). Figures 1 to 3 The above) and a compressible substrate (not shown in the figure).

[0079] In the second step, the connector element 1 and the substrate are arranged relative to each other. This step can be performed manually, semi-automatically, or automatically. The connector element 1 is arranged such that the protrusion 3 of the connector element contacts the proximal surface of the substrate. In the context of this invention, the protrusion 3 of the connector element 1 need not contact the proximal surface of the substrate, but should instead be aligned in a corresponding direction near the compressible substrate material.

[0080] The third step involves applying pressure and mechanical excitation. In this step, the protrusion 3 of the connector element 1 penetrates the substrate, particularly the proximal surface of the substrate, such that at least a portion of the thermoplastic material of the protrusion 3 and the thermoplastic material of the connecting member 4 is liquefied. Applying pressure may include compressing the substrate in the area where the connector element 1 has been arranged in the first step of the method. This increases the substrate density in the area until it is high enough to allow the protrusion to penetrate the substrate and at least partially liquefy the thermoplastic material of the protrusion and the thermoplastic material of the connecting member.

[0081] The fourth step of the method provides to stop the mechanical excitation, so that the liquefied thermoplastic material of the protrusion 3 and the liquefied thermoplastic material of the connector element 4 will be re-cured, and the applied pressure can also be stopped.

[0082] This specification and the accompanying drawings illustrating aspects and embodiments of the invention should not be construed as limiting the scope of the claims. In other words, while the invention has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions are intended to be illustrative or exemplary rather than restrictive. Various mechanical, compositional, structural, electrical, and operational changes may be made without departing from the spirit and scope of this specification and the claims. In some cases, well-known circuits, structures, and techniques have not been shown in detail to avoid obscuring the invention. Therefore, it should be understood that changes and modifications can be made by those skilled in the art within the scope and spirit of the appended claims. In particular, the invention covers further embodiments having any combination of features from the different embodiments described above and below.

[0083] This disclosure also covers all other features shown individually in the figures, although they may not have been described in the preceding or following description. Furthermore, individual alternatives to the embodiments described in the drawings and specification, and individual alternatives to their features, may be omitted from the subject matter of the invention or the disclosed subject matter. This disclosure includes subject matter consisting of features defined in the claims or exemplary embodiments, as well as subject matter including said features.

[0084] Furthermore, in the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plural. A single unit or step can perform the function of several features listed in the claims. The fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously. Terms related to attributes or values, such as "substantially," "about," "approximately," etc., also specifically and accurately define the attribute or precise value, respectively. The term "about" in the context of a given numerical value or range refers, for example, to a value or range within 20%, 10%, 5%, or 2% of the given value or range. Components described as being connected or linked may be electrically or mechanically directly connected, or they may be indirectly connected via one or more intermediate components. Any reference marks in the claims should not be construed as limiting the scope.

Claims

1. A connector element (1; 101; 102; 103; 104) for pressing the connector element (1; 101; 102; 103; 104) and a substrate together, and for securing the connector element (1; 101; 102; 103; 104) when pressed together. 102； 103； 104) and the substrate are mechanically stimulated relative to each other to bond to the substrate, including: The basal portion (2; 201; 202; 203; 204) having the distal surface (23); and A plurality of protrusions (3; 301; 302; 303; 304) extending distally from the distal surface (23) of the base portion (2; 201; 202; 203; 204), The protrusions (3; 301; 302; 303; 304) comprise a thermoplastic material configured to liquefy when the connector elements (1; 101; 102; 103; 104) are pressed onto the substrate and mechanically actuated. The connecting member (4; 401; 402; 403; 404) is characterized in that it comprises a thermoplastic material configured to liquefy when the connector element (1; 101; 102; 103; 104) is pressed onto the substrate and mechanically actuated, wherein each connecting member (4; 401; 402; 403; 404) connects two adjacent protrusions (3; 301; 302; 303; 304) in the protrusions (3; 301; 302; 303; 304).

2. The connector element (1; 101; 102; 103; 104) according to claim 1, wherein, The connecting components (4; 401; 402; 403; 404) are membrane-like.

3. The connector element (1; 101; 102; 103; 104) according to claim 1 or 2, wherein, The protrusions (3; 301; 302; 303; 304) have substantially the same protrusion length (31), and the connecting structural members (4; 401; 402; Each of 403; 404) connects at least two adjacent protrusions (3; 301; 302; 303; 304) along at least one-quarter of the protrusion length (31) of the protrusion (3; 301; 302; 303; 304).

4. The connector element (1; 101; 102; 103; 104) according to claim 1 or 2, wherein, The connecting structural component (4; 401; 402； 403; 404) protrude from the distal surface (23) of the base portion (2; 201; 202; 203; 204).

5. The connector element (1; 101; 102; 103; 104) according to claim 1 or 2, wherein, The base portion (2; 201; 202; 203; 204) has a circumference, and the protrusion (3; 301; 302; 303; 304) is arranged along the circumference of the base portion (2; 201; 202; 203; 204).

6. The connector element (1; 101; 102; 103; 104) according to claim 1 or 2, wherein, The base portion (2; 201; 202; 203; 204) includes a disk segment having a distal surface (23).

7. The connector element (1; 101; 102; 103; 104) according to claim 1 or 2, wherein, Each of the protrusions (3; 301; 302; 303; 304) includes a groove (7) extending distally along the protrusion (3; 301; 302; 303; 304).

8. The connector element (1; 101; 102; 103; 104) according to claim 7, wherein, The groove (7) extends substantially along the full length (31) of the protrusion.

9. The connector element (1; 101; 102; 103; 104) according to claim 1 or 2, wherein, Each of the protrusions (3; 301; 302; 303; 304) has a distal puncture end (9).

10. The connector element (1; 101; 102; 103; 104) according to claim 1, comprising a central dome-shaped portion (10; 1001) extending distally from the distal surface (23) of the base portion (2; 201; 202; 203; 204), wherein the central dome-shaped portion (10; 1001) is surrounded by the protrusion (3; 301; 302; 303; 304).

11. The connector element (1; 101; 102; 103; 104) according to claim 10, wherein, The central dome-shaped portion (10; 1001) has teeth (11; 1101) extending distally.

12. The connector element (1; 101; 102; 103; 104) according to claim 11, wherein, Each of the teeth (11; 1101) includes a groove (12) extending distally along the tooth (11; 1101).

13. The connector element (1; 101; 102; 103; 104) according to claim 11 or 12, wherein, Each of the teeth (11; 1101) has a distal puncture end (13).

14. The connector element (1; 101; 102; 103; 104) according to claim 10, wherein, The central dome-shaped portion (10; 1001) has a cavity (8) that opens on the proximal side (5) of the base portion (2; 201; 202; 203; 204).

15. The connector element (1; 101; 102; 103; 104) according to claim 14, wherein, The central dome-shaped portion (10; 1001) is configured such that the cavity (8) can withstand the bonding of the connector element (1; 101; 102; 103; 104) to the substrate.

16. The connector element (1; 101; 102; 103; 104) according to claim 14 or 15, wherein, The thickness of the sidewall of the central dome-shaped portion (10; 1001) is greater than the thickness of the protrusion (3; 301; 302; 303; 304).

17. The connector element (1; 101; 102; 103; 104) according to claim 14 or 15, wherein, The protrusions (3; 301; 302; 303; 304) protrude distally beyond the central dome-shaped portion (10; 1001).

18. The connector element (1; 101; 102; 103; 104) according to claim 1 or 2, wherein, The distal surface (23) of the base portion (2; 201; 202; 203; 204) has a flat section.

19. The connector element (1; 101; 102; 103; 104) according to claim 18, wherein, The flat section is the main part of the distal surface (23) of the base portion (2; 201; 202; 203; 204).

20. The connector element (1; 101; 102; 103; 104) according to claim 1 or 2, wherein, The base portion (2; 201; 202; 203; 204) is equipped with a proximal connection structure.

21. The connector element (1; 101; 102; 103; 104) according to claim 1 or 2, wherein, The cross-section of the protrusions (3; 301; 302; 303; 304) decreases in the distal direction.

22. The connector element (1; 101; 102; 103; 104) according to claim 1 or 2, wherein, At least some of the protrusions (3; 301; 302; 303; 304) are arranged in the base portion (2; 201; 202; 203; Near the circumferential edges (21; 2101; 2102) of 2043; 301; 302; 303; 304.

23. The connector element (1; 101; 102; 103; 104) according to claim 22, wherein, Each of at least some of the protrusions (3; 301; 302; 302; 303; 304) has an outer side (16; 1601; 1602) associated with the circumferential edge (21; 2101; 2102) of the base portion (2; 201; 202; 203; 204), and the outer side of at least some of the protrusions (3; 301; 302; 303; 304) is inclined.

24. The connector element (1; 101; 102; 103; 104) according to claim 1 or 2, wherein, The base portion (2; 201; 202; 203; 204) has a proximal flange portion (1702) and a distal cylindrical portion (1802).

25. The connector element (1; 101; 102; 103; 104) according to claim 24, comprising a rib (1902) connecting the flange portion (1702) and the cylindrical portion (1802).

26. The connector element (1; 101; 102; 103; 104) according to claim 25, wherein, The rib (1902) extends from the distal end of the flange portion (1702) to the outer surface of the cylindrical portion (1802).

27. The connector element (1; 101; 102; 103; 104) according to claim 3, wherein, Each of the connecting members (4; 401; 402; 403; 404) connects at least two adjacent protrusions (3; 301; 302; 303; 304) along at least one-third of the protrusion length (31) of the protrusion (3; 301; 302; 303; 304).

28. The connector element (1; 101; 102; 103; 104) according to claim 3, wherein, Each of the connecting members (4; 401; 402; 403; 404) connects at least two adjacent protrusions (3; 301; 302; 303; 304) along at least half of the protrusion length (31) of the protrusion (3; 301; 302; 303; 304) or along at least two-thirds of the protrusion length (31) of the protrusion (3; 301; 302; 303; 304).

29. A connector element (1; 101;) according to any one of claims 1-28 102； 103； 104) A method of bonding to a compressible substrate having a proximal surface, comprising: The connector elements (1; 101; 102; 103; 104) are arranged on the substrate such that the protrusions (3; 301; 302; 303; 304) of the connector elements (1; 101; 102; 103; 104) extend toward the proximal surface of the substrate. Apply pressure and mechanical excitation to cause the protrusions (3; 301; 302; 303; 304) of the connector elements (1; 101; 102; 103; 104) to penetrate the substrate and cause at least a portion of the thermoplastic material of the protrusions (3; 301; 302; 303; 304) and the thermoplastic material of the connecting structural members (4; 401; 402; 403; 404) to liquefy, and Stop the mechanical excitation so that the thermoplastic material of the protrusions (3; 301; 302; 303; 304) and the thermoplastic material of the connecting structural members (4; 401; 402; 403; 404) are re-cured.

30. The method according to claim 29, wherein, For the connector elements (1; 101; 102; 103; 104) Apply pressure to the portion of the substrate in which the connector elements (1; 101; 102; 103; 104) are arranged to compress the substrate.

31. The method according to claim 29 or 30, wherein, When the connector elements (1; 101; 102; 103; are connected to the connector elements (1; 101; 102; 103; 104) When pressure is applied, the substrate density in the portion of the substrate where the connector element is arranged increases until it is high enough to allow the protrusion to penetrate the substrate and liquefy the thermoplastic material of the protrusion (3; 301; 302; 303; 304) and the thermoplastic material of the connector element (4; 401; 402; 403; 404).

32. The method according to claim 29 or 30, comprising stopping the application of pressure after the thermoplastic material of the protrusions (3; 301; 302; 303; 304) and the thermoplastic material of the connecting structure (4; 401; 402; 403; 404) has been re-cured.

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