EP2854222A1

EP2854222A1 - Two-part electrical contact

Info

Publication number: EP2854222A1
Application number: EP20130186002
Authority: EP
Inventors: Alexander Weiss; Bart Colpaert; Bart Kerckhof; Patrick De Volder; Jos De Man; Dries Nollet
Original assignee: Tyco Electronics Belgium EC BVBA
Current assignee: TE Connectivity Belgium BVBA
Priority date: 2013-09-25
Filing date: 2013-09-25
Publication date: 2015-04-01
Anticipated expiration: 2033-09-25
Also published as: EP2854222B1

Abstract

The present invention relates to a two-part electrical contact (1) and method of assembly thereof. The electrical contact (1) comprises a first part (5) configured with a first contacting zone that is at least partially inserted into a second part (10) configured with a second contacting zone. The first part (5) is inserted into the second part (10) to fix the first part (5) and the second part (10) together in mechanical and electrical engagement. The second part (10) is configured with at least one opening (15) to receive the first part (5) and at least one recess (25, 58) provided on an internal surface (30) of the at least one opening (15). The recess (25, 58) is capable of receiving displaced electrical contact material from the first part (5). The first part (5) is configured with at least one deformation zone (20, 50) that is capable of being deformed and is configured to at least partially fill the at least one recess (25, 58) when deformed. The at least one deformation zone (20, 50) is configured to undergo deformation by an abutment of the first part (5) with the second part (10). The method of assembly involves fixing the first part (5) and the second part (10) to each other and the surrounding material by moving the first part (5) into abutment with the second part (10) where the first part (5) is at least partially inserted into the second part (10), and then causing a localized bulging (70) of the outer cross sectional dimension of said second part (10) at an at least one location.

Description

The present invention relates to a modular electrical contact. In particular, the present invention relates to a two-part electrical contact, and the method of manufacture and assembly of such a modular electrical contact.
Electrical contacts have become ubiquitous in the various electrical and electronic products of all shapes and sizes. Different needs associated with the contacting of various components of such devices determine the features that need to be present on the electrical contacts. While one end of different electrical contacts may look essentially the same, for example a wire crimping end of an electrical contact; the contact portions of such terminals may need to differ substantially. The design of the contact portion depends upon the corresponding electrical or electronic component being contacted by the electrical contact. Depending upon the particular intended application, the contact portion may be formed in a large variety of shapes and cross sections, enabling a similarly diverse use. Square or rectangular cross-sectional contact portions are often utilized for applications requiring wire-wrapping or in male-female contact terminal combinations. Round or square cross-sectional contact portions are often used in contacting circuit board connecting features. Compliant pin shaped contact portions are utilized most often for applications where direct circuit board connections are required.
Manufacturing electrical contacts with the requisite set of features as dictated by their intended use implies that a number of different electrical contacts or contact terminals must be manufactured. Each particular combination of features at the front and back ends of an electrical contact must be manufactured separately. This considerably reduces the economy of scale during manufacture, and correspondingly increases the logistical needs such as obtaining and keeping available minimum inventories of the various kinds of electrical contacts that a business may use.
Other applications, such as ones that require different electrical and physical properties of materials at one or the other end of a given electrical contact, also suffer from the considerable increase in the complexity and costs of manufacturing such electrical contacts. Usual methods such as coating a desired type of material over a base material or inlaying of strips of the desired material at specific locations within a base material or even forming a 'pad' of the desired material at specific locations are all resource intensive in terms of manufacturing effort required and are therefore expensive. In addition, these known methods may suffer from problems such as only a partial satisfaction of the properties required in a given part of an electrical contact, especially concerning physical properties. And they may also suffer from potential failure by the removal of material layers or the gouging out of the inlaid strips or the dislodgement of the pads, for the examples mentioned above, respectively.
The need for a two-part electrical contact terminal has led to the development of a variety of two-piece electrical contacts. Examples such as the two piece pin/socket contact as disclosed in EP 0948088 or the two piece male terminal as disclosed in US 5399110 are well known. Various methods of fixing the two contact terminal parts that together form an electrical contact are known. Typical methods are the placement of the two halves together and then crimping or welding them to fix them in place with respect to each other, or even forcing the two parts together to cause an interference fixation of the parts when the contact areas have the appropriate dimensions. Other ways such as the provision of locking features that interact with each other to lock the two halves together are also known. Combinations of one or more types of fixation known in the art are also commonly utilized, depending upon the needs of the particular application.
Interference fixation or frictional holding of two parts together to form an electrical contact is typically traumatic to the material and surfaces that are in contact. Such a fixation also causes corresponding scratching or deformation of surfaces when in an intermediate stage of the insertion of one part into the other. This can lead to additional problems such as surface shavings or whiskers being formed, and can lead to contact failure or short circuiting of adjacent electrical contacts, which would be highly undesirable. Interference fixation utilizing ridges or barbs or the like being formed on one part that may be inserted into a corresponding second part to form an electrical contact would be particularly susceptible to such trauma or surface erosion related failures. Other ways of fixation may require the manufacture of complicated locking features, and may therefore drive up the costs of manufacture; or may require additional steps such as crimping, which itself may not always be an option, depending upon the particular location and status of the two parts being joined.
There is a need, therefore, for a two-part electrical contact that can be mass produced and assembled by a simple method of fixation that is also reliable and avoids the problem of surface erosion related trauma being caused to the surfaces of the two parts.
An easy to assemble two-part electrical contact may utilize different materials or even different configurations of one part of an electrical contact while allowing the corresponding other part to be 'standardized'. This makes available the added advantage of at least such a 'standardized' part being easily mass-produced. This would lead not only to economies of scale helping reduce the costs of manufacture, but would also enable the use of different materials better suited to the intended use of said half of the two-part electrical contact. As an example, certain applications may require the use of high strength materials in the contacting region and may function satisfactorily even with a less than perfect electrically conducting material elsewhere; whereas other applications may require an optimal material in terms of electrical properties in the contacting region, with the strength of the material not being of paramount importance. According to an exemplary embodiment of this invention, it would be possible to satisfy the needs of a situation where both such application characteristics are needed to varying degrees at the two ends of an electrical contact. The physical as well as electrical properties of both the parts of a two-part electrical contact can therefore be optimized.
The disadvantages mentioned above are overcome by a two-part electrical contact according to this present invention. The electrical contact described in the introductory part solves this problem according to the invention in that the electrical contact housing comprises two parts or halves. A first part may be configured with a first contacting zone that is at least partially inserted into a second part configured with a second contacting zone. The first part may be inserted into an opening in the second part to allow the fixation of the first part and the second part together in mechanical and electrical engagement according to this invention. The second part may be configured to have at least one recess that may be provided on an internal surface of the opening. Such a recess may be capable of receiving displaced electrical contact material from the first part, when a bending or flowing of material occurs in this region, for example by the application of an insertion or extraction force. The first part may be configured to have at least one deformation zone formed on it that may be capable of being deformed upon the application of such a force. When deformed, such a deformation zone may cause the material forming it to be bent or to flow to at least partially occupy any available nearby spaces, such as the recess. The at least one deformation zone may be made of an appropriate shape to allow it to undergo deformation by an abutment of the two parts together. Such an abutment may occur during an insertion or extraction/removal action of the first part with respect to the second part. The force that is applied to deform the deformation zone may be applied in either direction depending upon the particular features present on the two contact terminal parts or halves that allow an abutment to occur.
The solution according to the present invention can be supplemented and further improved by the following embodiments, each of which is individually advantageous, and which can be combined with one another as desired. The features of the individual embodiments, the advantages of which will be specified in greater detail in what follows, can be combined with one another as desired or indeed can also be selectively omitted as required, for a given exemplary implementation of this present invention.
In an exemplary embodiment, the deformation that occurs in the deformation zone as described above may cause the material forming the electrical contact to be bent or deformed such as to flow in a radially outward direction. Such a flow may be enabled by the provision of appropriate guiding features on either of the parts. Alternatively, the guidance may be achieved by the only available space for the bent or deformed material to move or flow into being provided in this radially outward direction. This fixation may be particularly advantageous, for example, to ensure that the fixation of the two parts does not require the scratching or gouging of material on any other surface. The physical interaction that may be considered even marginally traumatic to the surfaces in contact may therefore be restricted to the areas close to the deformation zone and the recess. Such a physical interaction may take place, for example, in the case of flat-tab like contact halves at the 'bottom' of the opening in the second part. In such a case, once the first part has been inserted into the second part almost all of the way in without necessarily causing or requiring the scratching of the internal surface of the opening, a simple application of an additional force or the continued application of the force inserting the first part into the second part may cause the deformation of the deformation zone as per this exemplary embodiment. The deformation zone may, as an example, be formed as a semicircular feature that has a central region congruent with the rest of the flat-tab and have at least partially curving 'legs' extending in either direction within the overall breadth of the tab. In their curved state, such legs may remain within the overall breadth of the tab and allow contact-free insertion into the second part. Such a semicircular feature might be thought of as a cross-section of a dome, supported at the top. This may be explained as a connection to the tab body along a tangent instead of along a diameter of a semi-circular cross section of a dome, for example. In such a case, the material forming the deformation zone would be displaced and would seek to fill nearby available empty space. A recess may be appropriately configured on the inside surface of the opening, such that the arrangement may cause the material to flow in this radial direction.
As a further possible implementation of this exemplary embodiment, the two contact halves may be formed to have a round cross-section. In such a case, the deformation zone may indeed be a semispherical or dome-shaped structure instead of a cross section thereof as described above. The curved semispherical structure may have its concave face facing in the forward direction, or towards the insertion end, while being supported at a tangential location closer to the body of the contact half. It may indeed also be formed as a protruding partially convex structure facing backwards or opposite to the insertion direction, in which latter case the dome might be imagined to be supported and formed with the inside surface in congruity with the contact half. In either of these configurations, i.e. convex or concave, having the deformation zone provided at the insertion end of the first part allows for an advantageously simple method of manufacture. The first part and the second part can be locked together in electrical and mechanical engagement simply by continuing the insertion process till the fully inserted position is reached. In the case of a concave deformation zone being provided at the insertion end, this would mean the concave deformation zone feature is pressed against the second half and caused to be flattened out. The flattening out would result in material that forms the deformation zone to be bent or caused to flow in an outwards direction. If the deformation zone is formed as a convex structure, the locking together of the first and second parts would require a small removal-direction movement of the first part so that appropriate features on the inside surface of the opening may abut the deformation zone and cause the fixation to be achieved.
As a further possible implementation of this exemplary embodiment, the two contact halves may be formed to have a square or rectangular cross-section. In such a case, the deformation zone may be formed as upstanding lance-like structures that would be suitable to abut either a front-facing surface if these are formed at the insertion end of the first part. These may indeed also be backwards-facing so that the action that locks the first and second parts together may be similar to a removal action intended to remove the first part from the opening in the second part. The movement itself may need to only be a small one in such a case, similar to the explanation above.
As a further advantageous exemplary embodiment of the current invention, the first half and the second half of the electrical contact may be formed having dissimilar cross sections. For example, a first part formed with a round or circular cross section may be inserted into a flat-tab like second part or vice versa, or indeed any possible permutation or combination in which the two electrical contact halves may be manufactured.
For the above mentioned examples, the deformation zone that may lock the two parts together may or may not be present on both sides of the flat tab implementation. As a possible exemplary embodiment, the deformation zone may be provided on a first radial side of the flat tab while the other side may not have such a deformation zone provided. Also, it may exemplarily not be provided along the full circumference or outside surface of the other three-dimensional implementations of this invention. It may be possible, for example, to provide the deformation zone only along a predetermined part of the outer surface, and have it absent from other parts. As an example, a round cross sectional first part may have a deformation zone along a portion of its total surface, and absent from the rest. For example, a section having the deformation zone may be provided at opposite ends of the first part, which may alternate with sections that do not have the deformation zone, along the circumference of the first part. As a further example, the provision of one or more deformation zones may be restricted to only a first radial side of the first part, and may be absent from another radial side of the first part. The provision of the deformation zone may be in any direction, with or without a symmetrical distribution of the same. In particular, such an arrangement could allow keying-in the first part into the second part and then causing their locking together by a rotational movement, similar to a traditional lock and key mechanism. The rotational movement may be accompanied by a pushing or pulling movement. The corresponding features present on the inner surface of the opening against which protrusions forming a deformation zone may abut may be formed as surfaces perpendicular to the insertion direction.
In another exemplary embodiment, such surfaces on the inside surface of the opening which are abutted by the deformation zone(s) may be tilted slightly from the plane perpendicular to the insertion direction. This may enable the three dimensional deformation zones to experience additional forces, when, for example, they are rotated to cause the keying-in movement to be achieved. In such an exemplary embodiment, the rotational movement too could cause the force required to deform those immediately abutting deformation zone features and/or the deformation zone features present at other locations to be exerted; thereby causing the deformation zone to deform.
The rotation may also arise from the angling of the protruding deformation zones in an appropriate manner to interact with a relatively flat surface provided in the opening. The rotation may cause the first part to be inserted further into the opening or withdrawn from it, depending upon the angles provided on the deformation zones. Such a configuration could be used, for example, to reinforce or add to the insertion forces that may cause a forward facing insertion end deformation zone to deform.
In another exemplary embodiment, the deformation zone may be formed as a helical protrusion that is angled forward or backward, to allow its deformation by the action of pressing inward or pulling outward, respectively, with reference to the direction of insertion being considered a forward or inward movement. In such an embodiment, the first part may be configured to be inserted at least partially into the second part by a rotational 'screw' action. Such an exemplary embodiment would interact with corresponding screw-like features present on the internal surface of the opening of the second part during the rotational action. Thereafter, the first part may be made to abut the second part, either by a pushing action further inserting it into the opening, as may be required for deforming a forward-angled deformation zone; or by pulling it in an outward direction to remove it from the opening, as may be required for deforming a backward-angled deformation zone.
In another exemplary embodiment of the present invention, more than one deformation zones may be provided on the first part and may have corresponding structures provided on the internal surface of the opening as may be required. Such a configuration, may, for example, enable the fixing of the first part in the second part at different depths as may be required for particular applications. Such a provision of two, three or more deformation zones as have been described above may also be useful to ensure greater pull-out forces being required before failure of the fixation may occur. For applications that may subject the electrical contact to a pulling force that may tend to cause failure of the fixation, it may be advisable to have a higher number of such deformation zones and corresponding features on the opening surface being provided.
In a further exemplary embodiment, the two or more deformation zones may be of dissimilar shapes. As an example, a front facing deformation zone formed as a semicircular or partial dome shape having a concave face at the front may be combined with a deformation zone formed as a forward angled helical protrusion on the body of the first part. Both of these deformation zones may be actuated and be deformed by a force exerted in the insertion direction. Any combination of the various deformation zones possible according to this invention may be provided. The actuation of more than one deformation zones may also be caused to occur by movements of the first part in opposite directions, and not only along the same direction. Such a combination may be useful, for example, to provide a secondary 'backup' deformation zone in a first part that may be actuated and deformed to cause the material forming the deformation zone to flow to fill an appropriately configured recess only when the first or first set of deformation zones may have disengaged. Such a disengagement may be caused by any reason, for example a material failure, or a predetermined sequence of locking having been configured into the two contact halves. Such a sequence may be configured to have staged locking that may only actuate once a preceding locking stage has failed either deliberately or as a failure. A combination of two or more deformation zones may therefore be utilized as a fail-safe, as a double or multi-point fixation of the first part in the second part, or as a controlled series of possible engagement and disengagement between the first part and the second part.
In an exemplary embodiment of the present invention, one or more deformation zones may be formed in different ways to achieve the physical shapes and properties suitable for the intended location of the deformation zones. The deformation zone may be formed as a section of the first part with a different cross-sectional dimension than the other sections of the first part, for example. In a flat tab implementation, this may be provided as a narrowing down of the width of the tab-like first part. In a three dimensional implementation, this may be provided as a thinner section of the first part that may then flare outward before or after the thin section to form the actual deformation zone legs or protrusions. As an example, it may also be possible to configure the deformation zone in an otherwise uninterrupted stretch of material by providing bend-guidance features formed on the first part. Such bend-guiding features may be formed as etchings on the flat/rounded/square/rectangular surface of the first part which may be provided using any known method. Examples of known methods may be processes such as coining, the use of different material properties in predetermined sections of the first part, the use of laser or other radiation based methods to form of weakened tracks in the material. Any such known method may be utilized to ensure that when the buckling of the material occurs, it first occurs at the predetermined locations intended to form the deformation zones. A combination of flat-tab like halves with three dimensional parts are also enabled by this invention, and require appropriately formed deformation zones as required by the two halves forming the electrical contact.
In a further exemplary embodiment of this invention, the second part may be provided with a number of recesses located at axially-separated locations on the inner surface of the opening. Such recesses may extend through the full circumference of the opening, or may be provided only on one or more predetermined radial sides of the opening in the second part. Such a non-congruous or non-symmetrical configuration may be utilized, for example, to ensure the keying-in feature as described above. In addition, such an axially separated provision of the recess may enable the use of similar second parts to receive a variety of first parts, where the first parts may differ in the depths to which they are inserted into the second part, thereby engaging different recesses to receive the flow of material from their deformation zones. A predetermined series of features against which deformation zones may abut may also be provided, in conjunction with the axially-separated recesses, wherever required.
In a further exemplary embodiment, the fixation of the first part with the second part may be required to be done with the first or the second part being surrounded by a surrounding material. As an example, the second part may be stitched into a connector housing and the first part may then be inserted into the second part to form the electrical contact as per this invention. Such an assembly of the electrical contact may be required, for example, where it is not possible to stitch the whole electrical contact through the material forming the connector housing, and insertion of the two parts is required from opposite ends into the material forming the connector housing.
The second part may be configured to have regions susceptible to bulging outwards upon the application of a force from the inside, directed in a radial direction. As an example, such a force may be exerted by the flow of material that forms the deformation zone upon deforming. This material may occupy the recess provided on the inner surface of the opening in the second part, and may in addition cause the second part to bulge outward at the locations where it is being pressed from the inside. This bulging outwards of the second part may cause a change in the external profile of the second part. This change in the external profile at one or more locations may be advantageous to ensure the secure fixation of the finished electrical contact within the material surrounding it. The bulging may additionally provide further functionality, such as improving the sealing properties of the interface between the electrical contact and the surrounding material.
In another exemplary embodiment, the bulging of external profile of the second part may be utilized to fix the finished electrical contact in place in a variety of surrounding materials. The needs of the application may, for example, exclude the stitching of the second and first parts through material such as plastic and may instead require the insertion through a pre-formed hole in a comparatively harder material. For example, two such bulgings may be configured to occur at locations that would be suitable to fix the finished electrical contact through a Printed Circuit Board (PCB). Two bulge features just above and just below the upper and lower surface planes of the PCB would enable the secure fixation of the terminal in its intended location. Any permutation and combination of features and function may be provided according to this invention without detracting from the inventive concept disclosed herein.
In an exemplary embodiment of this present invention, an electrical contact as described above may be assembled by inserting a first part of an electrical contact terminal configured with a first contacting zone into a surrounding material, then inserting a second part of the electrical contact terminal configured with a second contacting zone into the surrounding material such that the first part end up being at least partially inserted into the second part. The first part may then be fixed to second part and they may both be fixed in the surrounding material. Such a fixing may be achieved by moving the first part into abutment with the second part where the first part is at least partially inserted into the second part, and then causing a localized bulging of the outer cross sectional dimension of said second part at one or more locations. Such a movement may be a pushing action, a pulling action, a rotating or any similar movement of the first part, including combination movements. The number of locations where such a bulging may be configured to occur may depend upon the specific requirements of the application, the nature of the surrounding material as well as the specific aim intended to be achieved. For example, for certain purposes, the provision of a single bulge may be sufficient. Examples of such a purpose may be, for example, any one or more of; the prevention of movement of the assembled electrical contact in any or in a particular direction as may be the case when used with PCBs, or an improvement of the holding forces holding the assembled electrical connector within a connector housing, or the improvement of the sealing characteristics of the interface between the electrical contact and the surrounding material such as the plastic of a connector housing, etc.
The bulging of the outer cross sectional dimension of the second part may be caused by a deformation of at least one deformation zone of the first part and engagement of the deformed deformation zone with an at least one recess in the second part. The location of the recess and the end-position of the deformation zone of the first part can be used to determine the locations where such bulging occurs on the second part. The material forming the deformation zone deforms and flows into the recesses and the forces involved may cause the outward bulging of the outside surface of the second part that is closest to the recess on the inner surface of the second part. For particular applications, for example an intended use of the bulging to hold the assembled electrical contact in position in a PCB, the bulging of the outer cross sectional dimension of the second part may be configured to occur at two axially-separated locations. The axial separation may be directly correlated to the thickness of the PCB into which the electrical contact is intended to be held, such that the two bulges abut an upper and a lower surface of the PCB. In this configuration, movement of the electrical contact in either direction may be prevented once the second part has been inserted into a hole present in the PCB and the first part has been inserted in to the opening and brought to its final position. The actual steps of the insertion may be changed to have the first part inserted into the opening first and the second part then being assembled over this. All movements and steps are relatively described and may be implemented by one or the other part being stationary and the corresponding part being moved.
A further exemplary embodiment may be the requirement of forming a holding surface in the electrical contact which may be abutted after assembly, for example by a retaining slide or any other form of fixation feature, to hold the electrical contact at a certain location. This may be particularly advantageous when other means of fixing the position of an electrical contact may be unavailable. In such an example, the bulge may be 'free standing' and not surrounded by any material when formed, and the electrical contact may then be held in such a position by the aforementioned slider or other means as may be required in a particular intended application.
In another exemplary embodiment of this present invention, a method of assembling an electrical contact assembly may comprise a number of steps. The steps may comprise inserting a first part of an electrical contact terminal that is configured with a first contacting zone into a surrounding material such as plastic or a hole in a PCB or a metallic sleeve in a PCB hole. The second part of the electrical contact terminal configured with a second contacting zone may then be inserted into the surrounding material such that the first part is at least partially inserted into the second part when an end-position is reached. The first part and the second part may then be fixed to each other and the surrounding material by moving the first part into abutment with the second part such that the first part is at least partially inserted into the second part. The abutment may then cause a localized bulging of the outer cross sectional dimension of said second part at an at least one location. As described above, such a bulging at one or more locations may enable the holding of the assembled electrical contact in a given desirable position by providing a feature that may be used for mechanical fixation of the electrical contact.
In a further exemplary embodiment of this present invention, the bulging of the outer cross sectional dimension of said second part is caused by a deformation of at least one deformation zone of the first part and engagement of the deformed deformation zone with an at least one recess in the second part. The outward force exerted by the deformed material forming the deformation zone may cause the outer cross section of the second part to bulge outward. The outwardly expressed bulging may correspond with the location of the recess provided on the inner surface of the opening in the second part. Alternatively, such a bulging may also be configured to be expressed at a location close to, but not directly corresponding with the location of the recess, and may be indirectly subjected to an outwards-tending force. Such an indirect direction of force may be enabled by rigidity-influencing features being provided on the inner surface of the opening in the second part, such as ribs or ridges or any other known form of mechanical load transmitting features that may enable the movement of force from one location to another.
The bulging of the outer cross sectional dimension of said second part may be caused at two axially-separated locations. Such an expansion of the cross section of the second part may be enabled by two separate deformation zones causing the bulging at corresponding locations, or alternatively, also by a single deformation zone acting in conjunction with mechanical force transmitting structures as mentioned above being provided on the inner surface of the opening.
The description above generally refers to the first part being inserted into the second part, but this is a relative description. It would be obvious that the first part may actually be stationary and the second part may be moved so as to receive the first part within the opening in the second part.
In what follows, the present invention will be specified in greater detail by way of example, within the context of embodiments, with reference to the attached set of drawings. The embodiments represent merely possible configurations, in which individual features, as described above, can be implemented independently of one another or can be omitted. In the interest of clarity, in the description of the embodiments, the same features and elements have been identified by the same reference signs.
The drawings show:

Figs. 1a, 1b, 1c and 1d show a schematic perspective and cross-sectional view of an embodiment of a tab contact according to the present invention;
Fig. 2a and 2b show a schematic perspective and cross-sectional view of an embodiment of a round contact according to the present invention;
Figs. 3a and 3b show a schematic perspective view of an embodiment of a square/rectangular contact according to the present invention;
Fig. 4 shows a schematic perspective and cross-sectional view of a variety of embodiments of electrical contact halves according to the present invention;
Fig. 5 shows a schematic perspective and cross-sectional view of an embodiment of a round contact with two axially separated deformation zones according to the present invention;
Figs. 6a, 6b, 6c and 6d show a schematic perspective view of a variety of embodiments showing various keying-in configurations according to the present invention; and
Fig 7. shows a schematic cross-sectional view of an embodiment of an electrical contact according to the present invention, after it has been assembled.

Figs. 1a, 1b, 1c and 1d show a schematic perspective and cross-sectional view of an electrical contact 1 according to an embodiment of the present invention. A first part 5 is positioned within a second part 10 by insertion into an opening 15 of the second part. In the illustration shown, a penultimate position of assembly is exemplified in Figs 1a and 1c, which show a deformation zone 20 provided on the first part 5 being positioned close to a recess 25 configured on an internal surface 30 of the second part 10. An application of force in the direction P, which corresponds with a forward or insertion direction, may bring the first part 5 and second part 10 into the final position as illustrated in Figs 1b and 1d. The deformation zone 20 on the first part 5 is cased to deform by the application of the force. This results in the material of the first part 5 forming the deformation zone 20 to deform and be caused to flow outwards to occupy the recess 25 present on the inner surface of the opening 15 formed on the second part 10. In the exemplary embodiment shown here, the deformation zone 20 is formed as a semicircular feature with a concave face at the forward or insertion end of the first part 5. This flow of deformed material from the deformation zone 20 causes the fixation of the first part 5 with the second part 10 both mechanically and by virtue of being made of a conductive material, electrically as well.
The Figures 1a, 1b, 1c and 1d illustrate the electrical contact to be a tab-contact, being assembled from opposite ends of a terminal carrying medium such as a printed circuit board. In the exemplary embodiment shown, shoulders 35 formed on the first part 5 provide a fixation of the first part 5 relative to the surrounding terminal-carrying medium or surrounding material. The second part 10 assembled onto the first part 5 and pressed downwards after achieving the penultimate position shown in figures 1a and 1c results in the fixation of the two parts together to form electrical contact 1.
Fig. 2a and 2b show a schematic perspective and cross-sectional view, respectively, of an embodiment of a round contact according to the present invention. The electrical contact 1 is provided with a semi-spherical or dome-shaped deformation zone 20 feature at the front or insertion end of the first part 5. The second part 10 is assembled onto the first part 5 such that the first part 5 is at least partially received into the opening 15. After the penultimate position is reached, a final application of a force that tends to push the first part 5 and the second part 10 together causes a deformation of the semi-spherical deformation zone 20. The material forming the deformation zone comes to be deformed and flows into the recess 25 formed on the inner surface of the opening 15 of the second part 10.
Figs. 3a and 3b show a schematic perspective view of an embodiment of a square/rectangular contact according to the present invention. The electrical contact 1 is formed of the first part 5 being assembled onto a surrounding material such as a PCB, and the second part 10 being positioned thereon in a penultimate position as shown in Fig 3a. A final application of force tending to push the two parts together leads to the assembly of the electrical contact as shown in Fig. 3b. The deformation zone 20 that may be formed as a feature with a semi-circular cross section may be deformed by the final application of force and the material forming the deformation zone may be deformed and caused to flow outwards to occupy the recess 25 formed on the inner surface of the opening 15 of the second part 10.
Fig. 4 shows a schematic perspective and cross-sectional view of a variety of embodiments of electrical contact halves according to the present invention. The assembly of dislike halves to form the electrical contact 1 is also possible and is illustrated here, for example, with a round contact first half 5 being assembled with a square contact second half 10. The assembly of this hybrid contact remains similar to the other embodiments described above. The use of different cross-sections of the first half 5 and the second half 10 may be based, for example, on the particular geometry and space available on each side of a surrounding material.
Fig. 5 shows a schematic perspective and cross-sectional view of an embodiment of a round contact with two axially separated deformation zones according to the present invention. Here, the deformation zone 20 is formed at a front or insertion end of the first part 5, and a second deformation zone 50 is formed at an axially separated location on the first part 5. In this exemplary embodiment of the present invention, both the deformation zones 20 and 50 may be caused to deform by a force applied in the penultimate stage of assembly. Such a first part 5 with two deformation zones 20 and 50 would require a correspondingly configured second part 10 with two abutment surfaces where each of the deformation zones 20 and 50 may abut and be deformed by the force. The opening 15 of the second part 10 may be formed with a stepped inner surface, presenting the step 55 as the surface against which deformation zone 50 may abut. The step 55 may be configured with an adjacent recess 58 that may receive material forming the deformation zone 50 once it is deformed.
Figs. 6a, 6b, 6c and 6d show a schematic perspective view of a variety of embodiments showing various keying-in configurations according to the present invention. The final force that may cause the first part 5 and the second part 10 to move from the penultimate position to their final relative position after the deformation of the deformation zone 20, 50 may be provided by an external means that tends to push the two parts together, or it may be enable by other features. A keying in feature as shown in Fig 6a may be formed on the second part 10 such that the insertion of the first part 5 into the opening 15 of the second part may only be enabled for a particular orientation of the first part. A keyhole feature 60 as shown in Fig. 6a built into the second part 10 in conjunction with a protrusion 65 built onto the first part 5 as shown in Fig 6b would enable the insertion of the first part 5 into the opening 15 only when the keyhole feature 60 aligns with the protrusion 65. Once inserted through the keyhole 60, the first part 5 may be free to rotate. The protrusions 65 may be provided with a slanted surface with respect to the direction D perpendicular to the direction P, say, along the direction S, as shown, and formed like the threads of a screw along a part of the outer circumference of the first part 5. These protrusions 65 may be configured to abut the inside surface of the keyhole and the material forming the surrounding surface of the opening 15 when rotated, such that it tends to move the first part 5 in the direction P when rotated. The final force required to assemble the first half 5 and second half 10 together to deform the deformation zone 20, 50 and form the electrical contact 1 may be provided by this screw-in configuration of the keyhole 60 and protrusions 65.
The keyhole 60 may also be provided in the second part 10 to make available an abutment surface such as the step 55 for deformation zones 50 formed as protrusions 65 shown in Figs. 6c. Here, the protrusions 65 are shown to be angled in the forward or insertion direction, i.e. in the direction P, to be suitable for deformation by a force acting in the insertion direction along the direction P.
Alternatively, the invention may further exemplarily enable an application requiring a deformation zone that may be actuated by a removal force, i.e. one that acts in the direction opposite to direction P. The first part 5 with protrusions 65 that are angled in the backward or removal direction as shown in Fig. 6d may be inserted through the keyhole 60, rotated 90° to bring the protrusions 65 away from the keyhole 60, and then caused to deform by a force acting in the backwards, removal direction. The step 55' provides the surface of abutment, in such a case. Recesses 25 may therefore be provided at appropriate locations on the inner surface of the opening 15 both before and after the keyhole 60. Such recesses may be located along the inner circumference of the opening 15 or at selective locations such as 90° away from the openings forming the keyhole 60.
Fig. 7 shows a schematic cross-sectional view of an embodiment of an electrical contact according to the present invention, after it has been assembled. The first part 5, upon full insertion into the second part 10, results in the deformation zones 20 and 50 being deformed and the material forming these deformation zones flows into the recesses 25 and 58, respectively. This flow of material may force the outside surface of the second part to bulge at locations corresponding with the locations of the recesses in the inside surface of the second part 10. The formation of bulges 70 on the outside surface of the second part 10 may be utilized to securely hold the electrical contact 1 in position within the surrounding material, which may be a connector housing or a PCB or may indeed be free-standing to provide holding features for any alternate form of fixation.

Claims

A two-part electrical contact (1) comprising a first part (5) configured with a first contacting zone that is at least partially inserted into a second part (10) configured with a second contacting zone, the first part (5) inserted into the second part (10) to fix the first part (5) and the second part (10) together in mechanical and electrical engagement; characterized in that
the second part (10) is configured with at least one opening (15) to receive the first part (5) and at least one recess (25, 58) provided on an internal surface (30) of the at least one opening (15) that is capable of receiving displaced electrical contact material from the first part (5), and wherein
the first part (5) is configured with at least one deformation zone (20, 50) that is capable of being deformed and is configured to at least partially fill the at least one recess (25, 58) when deformed, the at least one deformation zone (20, 50) being configured to undergo deformation by an abutment of the first part (5) with the second part (10).
The electrical contact as per claim 1 wherein the at least one deformation zone (20, 50) is configured to deform in a radially outward direction.
The electrical contact as per claims 1 or 2 wherein the at least one deformation zone (20, 50) is provided at an insertion end of the first part.
The electrical contact as per claims 1 to 3 wherein the at least one deformation zone (20, 50) is formed as a convex or concave structure at an insertion end of the first part.
The electrical contact as per claims 1 to 4 wherein two or more deformation zones (20, 50) are provided at axially-separated locations on the first part.
The electrical contact as per claims 1 to 5 wherein two or more deformation zones (20, 50) are of dissimilar shapes.
The electrical contact as per claims 1 to 6 wherein the at least one deformation zone (20, 50) is provided on a first radial side of the first part.
The electrical contact as per claims 1 to 7 wherein the at least one deformation zone (20, 50) is formed as at least one of: a section of the first part (5) with a different cross-sectional dimension than the other sections of the first part, or a section of the first part (5) with bend-guidance features formed on the first part.
The electrical contact as per claims 1 to 8 wherein two or more recesses are provided at axially-separated locations on the second part (10).
The electrical contact as per claims 1 to 9 wherein the at least one recess (25, 58) is provided on a first radial side of the second part (10).
The electrical contact as per claims 1 to 10 wherein an external profile of the second part (10) is configured to be capable of bulging outwards at an at least one location upon fixation of the first part (5) and the second part (10) in mechanical and electrical engagement.
The electrical contact as per claim 11 wherein the bulging outwards at an at least one location is configured to allow fixation of the electrical contact (1) in a surrounding material.
A method of assembling an electrical contact (1) assembly comprising the steps of:
a. inserting a first part (5) of an electrical contact terminal configured with a first contacting zone into a surrounding material;

b. inserting a second part (10) of the electrical contact terminal configured with a second contacting zone into the surrounding material such that the first part (5) is at least partially inserted into the second part (10); and

c. fixing the first part (5) and the second part (10) to each other and the surrounding material; said fixing being achieved by:
i. moving the first part (5) into abutment with the second part (10) where the first part (5) is at least partially inserted into the second part (10), and

ii. causing a localized bulging of the outer cross sectional dimension of said second part (10) at an at least one location.
The method according to claim 13 wherein the bulging of the outer cross sectional dimension of said second part (10) is caused by a deformation of at least one deformation zone (20, 50) of the first part (5) and engagement of the deformed deformation zone (20, 50) with an at least one recess (25, 58) in the second part (10).
The method according to claim 13 wherein the bulging of the outer cross sectional dimension of said second part (10) is caused at two axially-separated locations.