GB2556013A

GB2556013A - Articulating non planar contact system

Info

Publication number: GB2556013A
Application number: GB1601117.3A
Authority: GB
Inventors: Armstrong Neil
Original assignee: In2tec Ltd
Current assignee: In2tec Ltd
Priority date: 2016-01-21
Filing date: 2016-01-21
Publication date: 2018-05-23
Anticipated expiration: 2036-01-21
Also published as: GB201601117D0; GB2556013B

Abstract

An electrical contact system comprises a first and second portions 105,110 each comprising respective substrates 505,515 having curved surfaces. One or more electrical contacts 115,120 are disposed on the curved surfaces and the first portion rotates and/or translates relative to the second portion to couple and/or decouple the contacts. The contacts may be positioned at various azimuthal angles from the axis of rotation. The substrates may be flexible and their curvature may be identical. The first portion may comprise a spherical cap of substrate material. The first and second substrates may each have a central contact (615d,620d, figure 6) collinear with the axis of rotation. Also disclosed (figure 8) is an electrical contact system comprising first and second contact portions each comprising a respective hole and wiring disposed on a substrate, and a pin having a head and shaft dimensioned to fit in the hole to allow rotation of the first portion about the shaft. Also disclosed (figure 12) is an adhesive transfer sheet comprising at least one electrical circuit disposed on top of a dielectric layer, which is disposed on top of an adhesive layer.

Description

(54) Title of the Invention: Articulating non planar contact system Abstract Title: Rotating contact system (57) An electrical contact system comprises a first and second portions 105,110 each comprising respective substrates 505,515 having curved surfaces. One or more electrical contacts 115,120 are disposed on the curved surfaces and the first portion rotates and/or translates relative to the second portion to couple and/or decouple the contacts. The contacts may be positioned at various azimuthal angles from the axis of rotation. The substrates may be flexible and their curvature may be identical. The first portion may comprise a spherical cap of substrate material. The first and second substrates may each have a central contact (615d,620d, figure 6) coiiinear with the axis of rotation.

Also disclosed (figure 8) is an electrical contact system comprising first and second contact portions each comprising a respective hole and wiring disposed on a substrate, and a pin having a head and shaft dimensioned to fit in the hole to allow rotation of the first portion about the shaft. Also disclosed (figure 12) is an adhesive transfer sheet comprising at least one electrical circuit disposed on top of a dielectric layer, which is disposed on top of an adhesive layer.

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Intellectual

Property

Office

Application No. GB1601117.3

RTM

Date :21 July 2017

The following terms are registered trade marks and should be read as such wherever they occur in this document:

Bluetooth

Intellectual Property Office is an operating name of the Patent Office www.gov.uk/ipo

ARTICULATING NON PLANAR CONTACT SYSTEM

Field of invention

This invention relates in general to electrical contact systems, particularly articulating non planar electrical contact systems, and more particularly to flexible articulating non planar electrical contact systems.

Background

Electrical circuitry is being incorporated into an ever-increasing array of items. For example, wearable technology has recently become popular, with watches, wristbands, armbands and items of clothing, among other things, having electrical circuitry incorporated into their structure. These and other members of the so-called ‘Internet of Things’ move away from the traditional circuit formed on a rigid, planar sheet or substrate to an environment in which flexible circuitry is required that is capable of functioning correctly under unpredictable motion.

This new environment for electrical circuitry presents new challenges. One such challenge is related to electrical contacts, and in particular contacts that maintain a connection under unpredictable motion including translation and/or rotation. Another challenge relates to electrical switches, and in particular switches that make use of translation and/or rotation to make and break electrical connections. It is also desirable to provide such switches and contacts in a compact form.

Summary of the Invention

The present invention provides an electrical contact system, comprising:

a first portion comprising a first substrate including a curved surface;

a second portion comprising a second substrate including a curved surface;

one or more first electrical contacts disposed on the curved surface of the first substrate; and one or more second electrical contacts disposed on the curved surface of the second substrate;

wherein the first portion is arranged relative to the second portion such that the first portion is rotatable and/or translatable with respect to the second portion to:

a) electrically couple at least one of the first electrical contacts to at least one of the second electrical contacts; and/or

b) electrically decouple at least one of the first electrical contacts from at least one of the second electrical contacts.

In another aspect, the invention provides an electrical contact system, comprising:

a first contact portion comprising a first substrate including a first hole, the first substrate having first wiring disposed on a surface thereof;

a second contact portion comprising a second substrate including a second hole, the second substrate having second wiring disposed on a surface thereof; and a pin having a head and a shaft, the shaft dimensioned to fit into the first hole and into the second hole such that, when the pin is in place, the first contact portion is rotatable with respect to the second contact portion about an axis of the shaft.

In a further aspect, the invention provides a system, comprising: a visor; a helmet;

an electrical contact system according to any one of claims 12 to 19, wherein the first contact portion is integrated into the visor and the second contact portion and pin are each integrated into the helmet.

In a still further aspect, the invention provides an adhesive transfer sheet, comprising: an adhesive layer; a dielectric layer; and at least one electrical circuit;

wherein the at least one electrical circuit is disposed on top of the dielectric layer, and the dielectric layer is disposed on top of the adhesive layer.

Brief Description ofthe Drawings

Embodiments of the present invention are now described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a top view of an electrical contact system according to a first embodiment;

Figure 2 is a top view of the electrical contact system shown in Figure 1 when the contact system is rotated about a longitudinal axis of the contact system;

Figure 3 is a top view of the electrical contact system shown in Figure 1 when a top portion of the contact system is translated relative to a bottom portion of the contact system;

Figure 4 is a perspective view of the electrical contact system shown in Figure 1;

Figure 5A is a simplified cross-sectional view of the electrical contact system shown in Figure 1;

Figure 5B is a simplified cross-sectional view ofthe electrical contact system shown in Figure 1 when translated into the position shown in Figure 3;

Figure 6 is a top view of an electrical contact system according to a second embodiment;

Figure 7 shows an electrical contact suitable for use in in an electrical contact system of the first or second embodiment;

Figure 8 is a perspective view of an electrical contact system according to a third embodiment;

Figure 9 shows a spring-loaded ball contact suitable for use in the electrical contact system of the third embodiment;

Figure 10 shows a clip-on visor that can make use of any of the electrical contact systems of the first, second and third embodiments;

Figure 11 shows a helmet suitable for use with the clip-on visor shown in Figure 10; and

Figure 12 shows an adhesive transfer sheet having electrical circuity disposed on a surface thereof according to an embodiment.

Detailed Description of Embodiments

Figures 1 to 5B shows an electrical contact system 100 according to a first embodiment. As best shown in Figure 4, system 100 is disc shaped. The invention is however not limited in this respect and system 100 can take any regular or irregular shape deemed suitable by a skilled person having the benefits of the present disclosure.

System 100 comprises a top portion 105 and a bottom portion 110 (see Fig. 4). In use, top portion 105 sits on top of bottom portion 110 and is slidable and/or rotatable with respect to bottom portion 110. For the avoidance of doubt it is understood that references in the following to top portion 105 being rotatable with respect to bottom portion 110 include the reciprocal arrangement in which bottom portion 110 is rotatable with respect to top portion 105. Additionally, references in the following to top portion 105 being translatable with respect to bottom portion 110 include the reciprocal arrangement in which bottom portion 110 is translatable with respect to top portion 105. A translational motion is understood to include sliding motion between two surfaces disposed adjacent one another, where the surfaces maintain an approximately constant separation during the translational motion. Preferably, the surfaces maintain a substantially constant separation during the translational motion.

Top portion 105 comprises a curved substrate 505 (see Fig. 5A) that has a first set of electrical contacts 115 disposed on a curved surface thereof. In the first embodiment the substrate is formed of a spherical cap of substrate material. It will however be appreciated that the invention is not limited to this shape and that substrate 505 can take the shape of any other regular or irregular curved surface. Optionally, top portion 105 can include a backing layer 510 (see Fig. 5A) that serves to protect the curved substrate and to offer additional structural integrity to substrate 505.

Bottom portion 110 comprises a substrate 515 having a curved surface. Preferably the shape of substrate 515, and in particular the curvature of the curved surface of substrate 515, is chosen such that it complements the shape of substrate 505 of top portion 105. Herein, by ‘complements’ it is meant that substrate 505 is readily translatable and/or rotatable with respect to substrate 520. Preferably the curvature of the curved surface of bottom portion 110 is approximately the same as the curvature of the curved surface of top potion 105. More preferably the curvature of the curved surface of bottom portion 110 is substantially identical to the curvature of the curved surface of top potion 105.

Substrate 505 and substrate 515 can be made of any suitable electrically non-conductive material known to a skilled person that can be shaped into a curve and on which wiring can be disposed. For example, substrates 505 and 515 can be a flexible plastic substrate such as a polyether ether ketone (PEEK) film. Substrates 505 and 515 do not have to be flexible, as rigid materials that are nevertheless suitable for forming curved surfaces can be used instead for substrates 505 and 515. It will be appreciated that substrate 505 can be made of a different material to substrate 515.

In the first embodiment, first set of electrical contacts 115 includes three electrical contacts 115a, 115b and 115c. In the first embodiment contacts 115a, 115b and 115c are each a substantially spherical piece of electrically conductive material, e.g. a metal such as silver, but the invention is not limited in this respect and contacts 115a, 115b and 115c can be any type of electrical contact known in the art. The contacts may be a composite material having an electrically conductive coating as known in the art.

It will be appreciated that the invention is not limited to three contacts and first set of electrical contacts 115 can instead comprise one contact, or a plurality of contacts. Each contact 115a, 115b, 115c is electrically connectable to an exterior circuit (not shown) by wiring 125 which can be made of any suitable electrically conductive material as will be readily selected by a skilled person. In the first embodiment, wiring 125 comprises silver conductive tracks as is known in the art of printed circuit board design and manufacture. A first portion 125a of wiring 125 that is part of the interior of contact system 100 is provided on substrate 505 and a second portion 125b of wiring 125 that is electrically coupled to the first portion 125a and exterior to contact system 100 is also provided. Preferably, second portion 125b of wiring 125 is printed on a flexible substrate that is bendable to some degree. The second portion of wiring 125 may be referred to as a ‘flexibly flying lead’ in the art.

As used herein, the term ‘electrically coupled’ is understood to mean that an electrical connection has been formed between a first entity and second entity such that a non-negligible electrical current can to flow from the first entity to the second entity (or vice versa). An electrical connection may require at least some degree of physical contact between the first and second entities. Thus, in the case of electrical contacts, a pair of contacts may be said to be electrically coupled when electrically conductive portions of the contacts are physically touching. A coupling can also include wireless coupling, such as inductive coupling, which in the context of a pair of contacts may be achieved by bringing a first contact proximate the second contact.

A second set of electrical contacts 120 is provided on a curved surface of bottom portion 110. In the first embodiment, second set of electrical contacts 120 also includes three electrical contacts 120a, 120b and 120c. It will be appreciated that the invention is not limited to three contacts and second set of electrical contacts 120 can instead comprise one contact, or a plurality of contacts. In preferred embodiments, first set of electrical contacts 115 comprises the same number of contacts as the second set of electrical contacts 120. Each contact 120a, 120b, 120c is electrically connectable to an exterior circuit (not shown) by wiring 130 which can be made of any suitable electrically conductive material. In the first embodiment, wiring 130 comprises silver conductive tracks as is known in the art of printed circuit board design and manufacture. A first portion 130a of wiring 130 that is part of the interior of contact system 100 is provided on the curved surface of substrate 510 and a second portion 130b of wiring 130 that is electrically coupled to the first portion 130a and exterior to contact system 100 is also provided. Preferably, second portion 130b of wiring 130 is printed on a flexible substrate that is bendable to some degree. The second portion of wiring 130 may be referred to as a ‘flexibly flying lead’ in the art.

In the first embodiment contacts 115a, 115b and 115c are each an arcuate sheet of electrically conductive material, but the invention is not limited in this respect and contacts 120a, 120b and 120c can be any type of electrical contact known in the art.

Referring here in particular to Figure 4, in the interests of clarity the present disclosure makes use of a cylindrical polar coordinate system having a longitudinal axis z, a radial axis r and an azimuthal angle Θ. As show in Figure 4, for clarity of description longitudinal axis z is selected such that it is collinear with the longitudinal axis of electrical contact system 100. It will be appreciated that these choices are for convenience of description only and that they do not place any limitation on the present invention.

As shown in Figure 1, in the first embodiment contacts 115a, 115b and 115c are radially offset from one another but have no angular offset. The radial distance between adjacent ones of contacts 115a, 115b and 115c is substantially identical and is denoted Ar. As also shown in Figure 1, in the first embodiment contacts 120a, 120b and 120c are radially offset from one another and are also in an azimuthal offset relation to one another. The radial distance between adjacent ones of contacts 120a, 120b and 120c is substantially identical and is also substantially identical to Δγ. The angular offset between adjacent ones of contacts 120a, 120b and 120c is substantially identical and is denoted ΔΘ. These radial and azimuthal spacings can be varied if desired and such variations will be readily apparent to a skilled person having the benefit of the present disclosure.

Top portion 105 is rotatable about longitudinal axis z with respect to bottom portion 110. Top portion 105 is also translatable with respect to bottom portion 110 as shown in Figure 5B. This freedom to rotate and to move in two dimensions, combined with the positions of the various electrical contacts described in the preceding paragraph, allows system 100 of the first embodiment to make nine distinct electrical connections. Specifically, the position of top portion 105 with respect to bottom portion 110 can be adjusted such that any one of contacts 115a, 115b, and 115c is in electrical communication with any one of contacts 120a, 120b, 120c.

For example, in Figure 1 contact 115b is coupled to contact 120b. Rotation of top portion 105 from the position shown in Figure 1 about the z axis results in, for example, the arrangement shown in Figure 2 in which contact 120a is coupled to contact 115a. Translation of top portion 105 from the position shown in Figure 1 results in, for example, the arrangement shown in Figures 3 and 5B in which contact 115a is electrically coupled to contact 120b. It will be appreciated by a skilled person having the benefit of the present disclosure that, through appropriate rotation and/or translation of top portion 105, any one of contacts 115a, 115b, and 115c can be brought into electrical communication with any one of contacts 120a, 120b, 120c. The result is a versatile switching arrangement formed, in essence, of two non-planar circuit layers that can move in non-planar motion relative to each to enable switching of one of more circuits.

The rotational range and/or translational range of top portion 105 can be restricted by a surrounding support mechanism (not shown) such as a housing. The nature of the support mechanism will be readily selected by a skilled person having regard to the specific situation at hand. For example, the support structure can comprise a pair of bodies, one supporting each of top portion 105 and bottom portion 110.

It will be appreciated that reciprocal arrangements in which bottom portion 110 translates and/or rotates with respect to top portion 105 are also within the scope of the present invention.

It will also be appreciated that the arrangement of first and second sets of electrical contacts 115, 120 can be varied in numerous ways according to the specifics of a given situation. For example, second set of electrical contacts 120 could include pairs of radially offset contacts that are arranged at the same azimuthal such that multiple electrical couplings can be made simultaneously. Equally, first set of electrical contacts 115 could include pairs of azimuthally spaced contacts at the same radial distance, again allowing multiple electrical couplings to be made simultaneously.

The radial and/or azimuthal positioning of the contacts can be adjusted to suit the specifics of the situation at hand, allowing multiple electrical connections to be simultaneously made, maintained and/or broken according to the position of top portion 105 with respect to bottom portion 110. The radial and/or azimuthal extent of a given contact can be adjusted in addition to or in the alternative to adjustment of the position of the contact in order to further control at which relative positions connections are made, maintained and/or broken. These and other such modifications will become apparent to a skilled person having the benefit of the present disclosure.

Referring now to Figures 5A and 5B, it is preferred that the vertical or z-axis offset between top portion 105 and bottom portion 110 remains approximately constant throughout rotational and translational motion of either top portion 105 or bottom portion 110. More preferably, this offset remains substantially constant throughout rotational and translation motion of either top portion 105 or bottom portion 110. For ease of illustration and understanding the size of the offset between the top and bottom portions is exaggerated in Figures 5A and 5B, and the surrounding support structure that holds top portion 105 at constant vertical offset with respect to bottom portion 110 is omitted from Figures 5A and 5B.

In the first embodiment the surrounding support structure is a disc-shaped housing as best shown in Figure 4. As set out above, top portion 105 includes a concave substrate 505 with a planar backing layer 510. Bottom portion 110 includes a substrate 515 having a concave upper surface and a planar lower surface which can serve as the base for contact system 100. The curvature of the curved surfaces of the top and bottom portions is chosen such that they complement each other, to enable smooth slidable and rotatable motion of top portion 105. Preferably, these curved surfaces have approximately the same curvature and more preferably these curved surfaces have substantially identical curvature.

In some cases it may be advantageous to have one or more pairs of electrical contacts that remain coupled regardless of the rotational and/or translational position of the top and bottom portions of the contact system. One way of achieving this is shown in Figure 6, which depicts a second embodiment of the invention. In Figure 6, elements that are similar to corresponding elements of the first embodiment have been given the same suffix. The description of such elements set out above applies equally unless explicitly stated otherwise.

Figure 6 shows an electrical contact system 600 according to a second embodiment. Like system 100, system 600 includes a first set of contacts 615 formed on a top portion 605 of system 600 and a second set of contacts 620 formed on a bottom portion 610 of system 600. Additionally, first set of contacts 615 includes a central contact 615d centred approximately on the z axis when top portion 605 is positioned directly above bottom portion 610. Further, second set of contacts 620 includes a central contact 620d that is approximately centred on the z axis.

The arrangement of contacts 615a, 615b and 615c is the same as corresponding contacts 115a, 115b and 115c of the first embodiment. Similarly, the arrangement of contacts 620a, 620b and 620c is the same as corresponding contacts 120a, 120b and 120c of the first embodiment. This enables rotation of top portion 605 to bring any one of contacts 615a, 615b and 615c into electrical communication with any one of contacts 620a, 620b and 620c in the manner as described in connection with the first embodiment.

First set of contacts 615 are electrically coupled to external circuity via wires 625 having first portion 625a and second portion 625b and the second set of contacts 620 are electrically coupled to external circuitry via wires 630 having first portion 630a and second portion 630b. Wires 625 and 630 are the same as their respective counterparts 125 and 130 of the first embodiment.

As shown in Figure 6, central contacts 615d and 620d are both approximately on the z axis when top portion 605 is positioned directly above bottom portion 610. This means that the electrical coupling between contact 615d and 620d is maintained under full 360 degree rotation of top portion 605 with respect to bottom portion 610 about the z axis. Contacts 615d and 620d may therefore be termed ‘rotationally independent contacts’ as their coupling is independent of the rotational position of top portion 605.

It will be appreciated that it contacts 615d and 620d do not have to be located approximately on the z axis in order to be rotationally independent contacts. For example, in another nonillustrated embodiment, contact 615d is located at a non-negligible radial distance from the z axis and contact 620d takes the form of a ring or circle of radius at least equal to the distance at which contact 615d is offset from the z axis. In this arrangement the coupling between contacts 615d and 620d is also uninterrupted under rotation of top portion 605 with respect to bottom portion 610 about the z axis.

Additionally, in the second embodiment, central contact 620d extends in the radial direction to form a circular contact pad. This means that an electrical coupling between contact 615d and 620d is maintained during translation of top portion 605 with respect to bottom portion 610 in any direction over a distance equal to the radius of the circular contact pad. If an unbroken electrical coupling is required then the radius of central contact 620d is preferably chosen to be at least the radial offset of contact 615d when top portion 605 is at maximal translation with respect to bottom portion 610, such that even at this extremal position the electrical coupling between contact 615d and 620d is not interrupted.

It is also possible for central contact 620d to itself provide switching functionality. One way that this can be achieved is shown in Figure 7, which depicts a contact 700 having multiple contact surfaces 705, 710 and 715 that are each capable of forming an electrical coupling with another electrical contact such as contact 615d. Each contact surface can be any suitable electrically conductive surface, such as electrically conductive tracking as typically found on printed circuit boards. Other suitable forms for the contact surfaces will be readily realised by a skilled person.

In the illustrated embodiment, contact surfaces 705, 710 and 715 take the form of concentrically arranged circles. Contact surfaces 705 and 715 are unbroken, and contact surface 710 includes two breaks allowing it to define two sub-surfaces referred to herein as ‘left’ and ‘right’ sub-surfaces. The left sub-surface can be coupled to a different portion of an external circuit than the right sub-surface. It will be appreciated that this is an exemplary arrangement to assist in the understanding of the invention and that numerous modifications to this arrangement can be made.

In use, a contact like contact 615d may initially be electrically coupled to contact surface 705. This corresponds to top surface 605 being aligned with respect to bottom surface 610; i.e. zero translation of top surface 605 with respect to bottom surface 610. At a later time it may become desirable to break this initial electrical coupling and form a new coupling with the left subsurface of contact surface 710. To achieve this, top surface 605 can be translated to the left with respect to bottom surface 610 by a distance equal to the radial separation of contact portions 705 and 710, making an electrical connection between the portion of an external circuit connected to contact 615d and the portion of an external circuit connected to the left subsurface. Further translation of top portion 105 to the left breaks the electrical connection between contact 615d and the left sub-surface and forms a new electrical connection between contact 615d and contact surface 715.

In some cases it may be desirable to go straight from an electrical connection between contacts 615d and 705 to an electrical connection between contacts 615d and 715 without forming even a temporary connection to contact 710. In that case, contact 615d is translated such that it passes through a gap between the left and right sub-surfaces of contact 710, i.e. translation upward or downward in the arrangement in Figure 7. Depending on the configuration of contact 615d, a rotation of top surface 605 with respect to bottom surface 610 may be required to allow contact 615d to pass through a gap between the left and right subsurfaces of contact 710. Other more complex arrangements are possible where combinations of rotational and translational motion are required to make and break electrical connections. A skilled person having the benefit of the present disclosure will readily devise such arrangements. The housing of contact system 600 may be structured such that it guides the user through such motions. Additionally, it will be appreciated that contact 700 can be equally formed on top portion 605, and further that a plurality of contacts like contact 700 can be provided on one or both of top portion 605 and bottom portion 610.

Figure 8 shows an electrical contact system 800 according to a third embodiment. System 800 includes a first contact portion 805, a second contact portion 810 and a pin 815.

First contact portion 805 is formed of a disc-shaped substrate 820 having a hole 825 in the centre that is dimensioned to receive pin 815 as described below. Substrate 820 is of the type described above in connection with Figure 1. Substrate 820 does not have to be disc-shaped and can instead by any other regular or irregular shape. Similarly, in the third embodiment hole 825 has a circular cross-sectional shape, but this shape can be varied without departing from the scope of the invention.

First contact portion 805 also includes wiring on at least one surface of substrate 820 which can be made of any suitable electrically conductive material. In the third embodiment the wiring comprises three silver conductive tracks 830a, 830b, 830c as known in the art of printed circuit board design and manufacture. It will be appreciated that the invention is not limited to three conductive tracks and that any number of conductive tracks, including one and a plurality of conductive tracks, can instead be provided on substrate 820. Conductive tracks can be provided on both sides of substrate 820, if desired. Conductive tracks 830a, 830b, 830c are electrically coupled to an external circuit (not shown) via a lead 830, which is preferably a flexible lead similar to previously described leads 125 and 130. Each conductive track terminates in a spring-loaded ball contact 900 as shown in detail in Figure 9.

In the third embodiment second contact portion 810 is also formed of a disc-shaped substrate 835 having a hole 840 in the centre that is dimensioned to receive pin 815 as described below. Substrate 835 is of the type described above in connection with Figure 1. Substrate 835 does not have to be disc-shaped and can instead by any other regular or irregular shape. Similarly, in the third embodiment hole 840 has a circular cross-sectional shape, but this shape can be varied without departing from the scope of the invention. Preferably, the shape of substrate 835 is chosen to complement the shape of substrate 820 such that, when secured together by pin 815, first contact portion 805 is easily rotated with respect to second contact portion 810 about the axis of pin 815, and vice versa.

Second contact portion 810 also includes wiring on at least the surface of substrate 835 that is proximate first contact portion 805 when the first and second contact portions are secured together via pin 815. The wiring can be made of any suitable electrically conductive material. In Figure 8 dashed lines are used to indicate that wiring is provided on the ‘back’ surface of substrate 835; i.e. the surface of substrate 835 that is not in view from the perspective at which Figure 8 is drawn.

In the third embodiment the wiring on substrate 835 comprises one silver conductive track 845 as known in the art of printed circuit board design and manufacture. It will be appreciated that the invention is not limited to one conductive track and that any number of conductive tracks, including a plurality of conductive tracks, can instead be provided on substrate 835. Conductive tracks can be provided on both sides of substrate 835, if desired. Conductive track 845 is electrically coupled to an external circuit (not shown) via a lead 850, which is preferably a flexible lead similar to previously described leads 125 and 130.

Pin 815 comprises a head 855 and a shaft 860 that terminates in an ovoid structure 865. Ovoid structure 865 includes one or more cutout portions that enable it to collapse in on itself so that it can pass through holes 825 and 840 when an appropriate degree of force is applied to head 855 in the direction of arrow 870. In the third embodiment pin 815 is made of a plastic, but other suitable materials for pin 815 will be realised by a skilled person having the benefit of the present disclosure. Preferably, at least shaft 860 is formed of a non-electrically conductive material.

The dimensions of ovoid structure 865 are chosen such that, when expanded out to its full width, the widest point of ovoid structure 865 is larger than the diameter of each of holes 825 and 840. This allows pin 815 to secure the first and second contact portions together in the manner as will be readily apparent from consideration of Figure 8. It will be appreciated that the cutout portions in ovoid structure 865 can be omitted if ovoid structure 865 is instead made of a deformable material that deforms sufficiently to pass through holes 825 and 840 and which expands back out once doing so to prevent accidental disengagement.

When pin 815 is in place, rotation of first contact portion 805 with respect to second contact portion 810 about the longitudinal axis of pin 815 is possible. Equally, rotation of second contact portion 810 with respect to first contact portion 805 about the longitudinal axis of pin 815 is also possible. This enables electrical connections to be made and broken via rotation of one of the contact portions, enabling the whole arrangement to act as an electrical switch. Thus, radial and/or azimuthal offset contacts positioned as shown and described in the first and second embodiments can be used in the third embodiment.

In the third embodiment conductive track 845 extends in a hemisphere along the surface of substrate 835. This hemisphere thus acts as the ‘on’ setting of a switch. The hemisphere of substrate 835 that has no conductive tracking acts as the ‘off’ setting of a switch. Rotation of one of the contact portions 805, 810 with respect to the other contact portion about the longitudinal axis of shaft 860 allows the on and off settings to be selected.

The width of shaft 860 can vary along the length of shaft 860. For example, the portion of shaft 860 that is proximate head 855 could have a reduced width with respect to the width of shaft 860 that is proximate ovoid structure 865. This allows translational motion of second contact potion 810 with respect to first contact portion 805 is possible when pin 815 is in place. Such translational motion can be used to make and break selected electrical connections in the manner described in connection with the first and second embodiments. For example, a connection between tracks 830a and 845 could be broken by translation of second contact portion 810. The same translational motion could result in a connection being made between tracks 830b and 845. Substrates 820 and 835 can be curved like the substrates described in connection with the first and second embodiments in order to assist with this translational motion.

Figure 9 shows a spring-loaded ball contact 900 suitable for use in the electrical contact system 800 of any of the first, second and third embodiments. Contact 900 is particularly suited for use in the third embodiment and as such is described in this context.

Figure 9 is a cross-sectional view and shows contact 900 when first and second contact portions 805, 810 are secured together by pin 815. Contact 900 includes a ball 905 that is made of an electrically conductive material which is preferably a metal having good electrical conductivity. Ball 905 is secured by spring 910 to substrate 820 and is in electrical contact with the wiring on substrate 820, e.g. conductive tracking 830a. Spring 910 is made of an electrically conductive material and is preferably made of a metal having good electrical conductivity. By way of example in Figure 9 ball 905 is shown in electrical contact with track 830a, but it will be appreciated that a contact like contact 900 can be used to form an electrical connection with any of the wiring shown and described in any of the embodiments described herein.

Spring 910 is secured to substrate 820 using any suitable mechanism such as glue. Preferably a well 920 is provided on the surface of substrate 820 to accommodate ball 905. Well 915 is filled with an electrically conductive material which is preferably a conductive ink such as a silver conductive ink (not shown). This enhances the quality of the electrical connection between tracking 830a and spring 910, and hence a good contact between ball 905 and tracking 830a is ensured. Well 915 can be formed of any electrically conductive material such as a metal. Alternatively, well 915 can be a poor electrical conductor, e.g. a dielectric material, and in that case a hole in the wall of well 915 is provided to allow conductive tracking 830a to directly contact the electrically conductive material within well 915.

In use, when pin 815 secures contact portions 805 and 810 together, ball 905 ensures that a good electrical connection is made between the wiring on the substrates 820 and 835. Specifically, spring 910 biases ball 905 against substrate 835 so that a good connection is maintained even under rotational and/or translational motion of one of the contact portions 805, 810 with respect to the other contact portion.

Figures 10 and 11 respectively show a clip-on visor 1000 and corresponding helmet 1100 that can make use ofthe electrical contact system ofthe third embodiment.

Visor 1000 includes a pair of articulating joints 1005a, 1005b that are suitable for securing visor 1000 to helmet 1100 using, for example, a pin I hole type arrangement. Such securing mechanisms per se are well known in the art and hence are not described in detail here. It is sufficient to say that each joint 1105a, 1105b includes a hole 1010a, 1010b that accepts a respective pin 1105 provided on the exterior of helmet 1100. The pin can be pin 855 of the third embodiment. The invention is not limited in this respect and other visor I helmet securing arrangements can instead be used. It will be appreciated that, as well known in the art of helmet design, visor 1000 is removable from helmet 1100. Additionally, visor 1000 can be tilted upwardly and downwardly with respect to helmet 1100 by a user, and such motion is enabled by rotation of joints 1005a, 1005b about the axis of pin 1105 and its counterpart (not visible in Figure 11).

At least one of joints 1005a, 1005b includes at least one wire provided on a surface thereof. In the illustrated embodiment two wires are provided in the form of conductive tracks 1015a and 1015b on joint 1005b. These or other tracks could additionally or alternatively be provided on a surface of joint 1005a. These tracks are the same as the conductive tracks as described in previous embodiments. In Figure 10 tracks 1015a and 1015b are shown as dashed lines to indicate that they are provided on the reverse surface of visor 1000. Joints 1005a, 1005b can comprise contact portions 805, 810, respectively, in which case it will be understood that the wiring on joints 1005a, 1005b is the wiring on contact portions 805, 810.

In the illustrated embodiment tracks 1015a, 1015b are joined at joint 1005b such that they share a common connection to external circuitry (not shown). In some cases it may be necessary to provide separate connections to external circuitry; this can be achieved by providing one or more breaks in the tracking on joint 1005b.

Track 1015a connects to a first electronic component that requires electrical power and/or control signals. In the illustrated embodiment the first component is an electrochromic film of a type known in the art. The electrochromic film is disposed on an optically transparent portion 1020 of visor 1000, such that the user is able to adjust the tint of the visor by varying the voltage that the electrochemical film is exposed to. A power source (not shown) is provided in helmet 1100 to supply the requisite voltage when required. The connection to the power source is provided by track 1015a.

Track 1015b connects to second electronic component that requires electrical power and/or control signals. In the illustrated embodiment the second component is a speaker 1025 of a type known in the art. Speaker 1025 is connected to the power source via track 1015b.

The invention is not limited to the first and second electronic components shown in Figure 10. In one non-illustrated embodiment the first electronic component is a heater usable to dispel build-up of condensation on visor 1100. In another non-illustrated embodiment the second electronic component is a microphone. Numerous other electrical components such as one or more LEDs, a GPS antenna, a RFID or NFC antenna, a WiFi antenna and an antenna for other electromagnetic connection technologies such as Bluetooth or FM radio, etc. can additionally or alternatively be included in visor 1000. Additionally, embodiments in which just one electronic component is provided are also contemplated, as are embodiments in which a plurality of electronic components are provided.

Figure 11 shows a helmet 1100 suitable for use with visor 1000. As mentioned earlier, helmet 1100 includes a power source (not shown) which in the illustrated embodiment is a battery. Other portable sources of power known to a skilled person can alternatively be provided in helmet 1100. A control device such as a microcontroller or CPU (not shown) can also be provided in helmet 1100 to allow control signals to be sent to electronic components of visor 1000 via the conductive tracking disposed on joint 1005a and/or 1005b.

Helmet 1100 is formed of a body including an opening that, in use, is covered by visor 1000. Adjacent opposite ends of the opening are a pair of pins (only pin 1105 shown in Figure 11) that, as discussed above, cooperate with respective ones of joints 1005a, 1005b and holes 1010a, 1010b to facilitate a ‘clip-on’ attachment of visor 1000 to helmet 1100. In the illustrated embodiment conductive tracking 1110 is provided around pin 1105 only, but it will be appreciated that both pins can be surrounded by conductive tracking, if desired. In the illustrated embodiment the tracking is an unbroken ring, but this is merely illustrative and any shape can alternatively be used for tracking 1110. One or more breaks in tracking 1110 can also be provided, if desired. Preferably, the shape of tracking 1110 is chosen such that it makes a good electrical contact with tracking 1015a and 1015b whilst visor 1000 is rotated through all anticipated angles of use. This allows the user to adjust the position of visor 1000 relative to helmet 1100 without breaking the electrical connection between the power source and the visor components 1020, 1025.

Figure 12 shows an adhesive transfer sheet 1200 according to a fourth embodiment. Sheet 1200 includes a set of electronic circuits 1205a, 1205b, 1205c, 1205d. Each circuit is removed from sheet 1200 by cutting around the circuit. Sheet 1200 is formed from a flexible dielectric material that is suitable for having electronic components fixed to it. An adhesive such as glue is provided on a surface of sheet 1200 that does not have electronic circuitry disposed on it (hereafter the rear surface of sheet 1200).

Taking circuit 1205a as a representative example, each circuit includes one or more electronic components 1210. These electronic components can be freely chosen by a skilled person and may include any of the electrical contact systems described herein. Each component is printed on sheet 1200 using any suitable circuitry printing technology such as 3D printing technology. In the illustrated embodiment circuit 1205a includes components made from a conductive ink such as an ink containing carbon nanoparticles and/or silver, but the invention is not limited in this respect and any other suitable inks or the like can be used instead. Circuit 1205a can be, for example, an integrated circuit (IC) or a photonic integrated circuit (PIC), which are both known in the art.

In the illustrated embodiment four identical circuits are provided on a single sheet 1200.

However, the invention is not limited in this respect and any number of identical or dissimilar circuits can be provided on a single sheet like sheet 1200. One circuit per sheet is also contemplated.

Once removed from sheet 1200, the adhesive on the rear surface of the circuit allows it to be 5 stuck onto another surface for use. Many possible implementations are contemplated. In the illustrated embodiment circuit 1205a is a biometric sensor such as a heart rate monitor. The circuit can be fixed directly to the skin of a user, or to a user’s clothing. Many other variations will become apparent to a skilled person having the benefit of the present disclosure. In the illustrated embodiment the adhesive backing is ‘one use’, but multi-use adhesives can alternatively be used to enable each circuit to be adhered to and then removed from a surface multiple times, or to be successively adhered to a number of different surfaces.

It will be appreciated that embodiments described herein provide compact electrical contact systems that are suitable for use in situations not suited to traditional planar circuitry without sacrificing contact reliability. This increased versatility represents a substantial contribution to the art.

Numerous modifications, adaptations and variations to the embodiments described herein will become apparent to a person skilled in the art having the benefit of the present disclosure, and such modifications, adaptations and variations that result in additional embodiments of the present invention are also within the scope of the accompanying claims.

Claims

1. An electrical contact system, comprising:

a first portion comprising a first substrate including a curved surface;

a second portion comprising a second substrate including a curved surface;

2. The electrical contact system of claim 1, wherein the first substrate and second substrate are flexible substrates.

3. The electrical contact system of claim 1 or claim 2, wherein at least one of the first electrical contacts is arranged at a first distance from an axis of the electrical contact system and at a first azimuthal angle with respect to said axis, and wherein at least one of the second electrical contacts is arranged at a second distance from the axis of the electrical contact system and at a second azimuthal angle with respect to said axis, the first distance being equal to the second distance and the first azimuthal angle being unequal to the second azimuthal angle.

4. The electrical contact system of claim 1 or claim 2, wherein at least one of the first electrical contacts is arranged at a first distance from the axis of the electrical contact system and at a first azimuthal angle with respect to said axis, and wherein at least one of the second electrical contacts is arranged at a second distance from the axis of the electrical contact system and at a second azimuthal angle with respect to said axis, the first distance being unequal to the second distance and the first azimuthal angle being equal to the second azimuthal angle.

5. The electrical contact system of claim 1 or claim 2, wherein at least one of the first electrical contacts is arranged at a first distance from an axis of the electrical contact system and at a first azimuthal angle with respect to said axis, and wherein at least one of the second electrical contacts is arranged at a second distance from the axis of the electrical contact system and at a second azimuthal angle with respect to said axis, the first distance being unequal to the second distance and the first azimuthal angle being unequal to the second azimuthal angle.

6. The electrical contact system of any one of claims 3 to 5, wherein the axis is an axis of rotation about which the first portion is rotatable with respect to the second portion.

7. The electrical contact system of claim 1 or claim 2, comprising a first set of electrical contacts disposed on the curved surface of the first substrate and a second set of electrical contacts disposed on the curved surface of the second substrate, and wherein:

the first set of electrical contacts are each located at the same azimuthal angle with respect to an axis of rotation about which the first portion is rotatable with respect to the second portion, the first set of electrical contacts being equispaced by a separation distance;

the second set of electrical contacts are each located at different azimuthal angles with respect to the axis, the second set of electrical contacts being equispaced by the separation distance.

8. The electrical contact system of any one of claims 3 to 7, further comprising:

a first central contact disposed on the curved surface of the first substrate and collinear with the axis, and a second central contact disposed on the curved surface of the second substrate and collinear with the axis.

9. The electrical contact system of claim 8, wherein the first set of electrical contacts comprises three electrical contacts and the second set of electrical contacts comprises three electrical contacts.

10. The electrical contact system of any preceding claim, wherein the contact system is disc shaped, and wherein the first substrate comprises a spherical cap of substrate material.

11. The electrical contact system of any preceding claim, wherein the curvature of the curved surface of the first substrate is substantially identical to the curvature of the curved surface of the second substrate.

12.

Intellectual

Property

Office

Application No: GB1601117.3

12. An electrical contact system, comprising:

13. The electrical contact system of claim 12, wherein the first and second contact portions are both disc shaped.

14. The electrical contact system of claim 12 or claim 13, wherein the second wiring is disposed over a hemispherical portion of the second substrate.

15. The electrical contact system of any one of claims 12 to 14, wherein the first wiring comprises a plurality of conductive tracks.

16. The electrical contact system of any one of claims 12 to 15, further comprising at least one ball contact, the ball contact comprising an electrically conductive ball mounted on an electrically conductive spring, the spring secured to a well containing an electrically conductive material that is electrically coupled to one of the first wiring and the second wiring.

17. The electrical contact system of claim 16, wherein the electrically conductive material comprises an electrically conductive ink.

18. The electrical contact system of any one of claims 12 to 17, wherein the end of the shaft that is distal the head of the pin terminates in an ovoid structure that is configured to compress inwardly when the pin is inserted into the first hole and the second hole.

19. The electrical contact system of claim 18, wherein the ovoid structure includes at least one cutout portion.

20. A system, comprising: a visor;

a helmet;

21. The system of claim 20, wherein the visor comprises at least one electrical component and the helmet comprises a power source, wherein the first and second wiring electrically couple the at least one electrical component to the power source.

22. The system of claim 21, wherein the at least one electrical component is selected from the group consisting of: an electrochromic film, a speaker, and a heater.

23. An adhesive transfer sheet, comprising: an adhesive layer;

a dielectric layer; and at least one electrical circuit;

24. The adhesive transfer sheet of claim 23, wherein the at least one electrical circuit is a photonic integrated circuit or an integrated circuit.

25. The adhesive transfer sheet of claim 23 or claim 24, wherein the at least one electrical circuit includes at least one electrical contact system as defined in any of claims 1 to 19.

26. The adhesive transfer sheet of any one of claims 23 to 25, wherein the at least one circuit is configured as a biometric sensor.

27. An electrical contact system substantially as described herein with reference to Figures 1 to 9.

5

28. A helmet and visor system substantially as described herein with reference to Figures

10 and 11.

29. An adhesive transfer sheet substantially as described herein with reference to Figure