Contact position indicator

Abstract

A contact position indicator 100 for a switch 200 comprises an indicator 102 and a coupler link. Movement of the coupler link from a first position to a second position causes the indicator to move from a third position to a fourth position. Conversely, when the coupler link moves from the second position to the first position, the indicator moves back to the third position. When in the first position, the coupler link is not in contact with or physically coupled to the indicator. When moving to the second position, the coupler link may abut the indicator to apply a force to it and move it to the fourth position. The coupler link may move between the first and second positions along a linear path. The indicator may rotate between the third and fourth positions and may be urged towards the third position by a biasing member 107. A system 500 may comprise the contact position indicator 100 and a mechanical switching device 200 having a slider 210. The slider may couple a moving contact of the switch to a first end 114 of the coupler link and may move between fifth and sixth positions corresponding to different operating states of the switch.

Description

Field

[0001] The present invention relates to the provision and operation of a contact position indicating device, or a contact position indicator. The contact position indicator can indicate a state of a mechanical switching device. Background

[0002] A position indicating device, or a contact position indicator, is part of a switching device, or otherwise configured for operation in conjunction with a switching device. The contact position indicator indicates whether the switching device is in an open, closed, or (where appropriate) earthed position or state. More generally, a contact position indicator may be a part of, or configured for operation in conjunction with, mechanical switches, electrical switches, or any other switch that includes a moveable contact system.

[0003] Mechanical switching devices physically move conducting material, such as a piece of metal, to break or to make an electrical connection within an electrical circuit, thereby opening or closing the electrical circuit. A mechanical switching device may be said to be in an ON state when the switch is closed, allowing current to flow within the circuit. Similarly, the mechanical switching device may be said to be in an OFF state when the switch is open, thereby breaking the electrical connection within the circuit.

[0004] Where a contact position indicator is used to indicate the state of the mechanical switching device, the industry standard set by the International Electrotechnical Commission for low-voltage (i.e. below 1000 Volts for AC and 1500 Volts for DC) mechanical switching devices, or "switchgear and controlgear", (IEC 60947-1, edition 6.0, published 20 December 2022), requires that the state or position of the mechanical switching device be clearly and unambiguously indicated to a user.

[0005] A contact position indicator may constitute an important safety component of electrical equipment. Therefore, it is desirable to provide a contact position indicator that is reliable, i.e., providing a true reflection of the state of the mechanical switching device. For example, the contact position indicator must not be able to indicate an OFF state for the mechanical switching device when the mechanical switching device is in fact in an ON state.

[0006] Known contact position indicators comprise a mechanical linkage to connect or couple the switching means of the mechanical switching device to the indicating means of the contact position indicator. Various mechanical linkages are described in, for example: US 6130390 A; US 5981887 A; US 5477016 A; and CN 218939470 U.

[0007] It is desirable to provide an alternative contact position indicator. Summary

[0008] A contact position indicator, and a method for operating the contact position indicator, are provided herein. The contact position indicator may be used with a switch, e.g., an electrical switch, optionally a mechanical switching device comprising a slider that is configured to couple to the contact position indicator.

[0009] In a first aspect of the present disclosure, a device is provided in the appended independent apparatus claim, with optional features defined in the dependent claims appended thereto. In a second aspect, a method is provided of operating the device of the first aspect as defined in the appended independent method claim. Any features of the first aspect may be implemented as part of the method of the second aspect. In a third aspect, a system is provided comprising the device of the first aspect as defined in the appended independent apparatus claim. Any features of the first aspect may be implemented as part of the apparatus of the third aspect.

[0010] The device of the first aspect is a contact position indicator for a switch. The contact position indicator comprises an indicator (configured to indicate a state or position of the switch) and a coupler link. The coupler link and the indicator are configured such that a movement of the coupler link from a first position to a second position causes the indicator to move from a third position to a fourth position. When the coupler link moves from the second position to the first position, the indicator moves from the fourth position to the third position. When the coupler link is at the first position, the coupler link and the indicator do not touch and are not otherwise coupled.

[0011] In this way, a contact position indicator which is reliable, cheap and simple to construct may be provided. The movement of the coupler link from the first position to the second position (and vice versa) influences the position of the indicator without a physical coupling or joint between the two components, thereby providing a contact position indicator that may be a simple, cost-effective and versatile alternative to the mechanical linkages used in conventional contact position indicators. For example, no rivets or joint links or pins are required in the linkage mechanism, increasing the ease of assembly. As such, the number of components required to construct the contact position indicator can be lower than a conventional design, helping to ensure reliability and resilience, and dispensing with the time and effort required to assemble a conventional mechanism or design. A simpler and less complex contact position indicator for a switch may therefore be provided.

[0012] Moreover, since the coupler link and the indicator do not touch when the coupler link is at the first position, and are not otherwise physically coupled, the reliability of the contact position indicator may be improved. For example, this arrangement can help to ensure that vibration or chattering of the switch contacts (or other electromagnetic forces that may cause small movements of the components of the switch, such as a slider) does not adversely affect the reliable and clear indication of the switch state provided by the contact position indicator.

[0013] The feature that the coupler link and the indicator do not touch and are not otherwise physically coupled may be implemented in some examples by configuring the device with a physical gap between the coupler link and the indicator. As the coupler link moves from the first position to the second position, the subsequent movement of the indicator from the third position to the fourth position takes place with a time delay. Thus, the indicator may indicate that the switch is in an OFF state only after the switch has in fact transitioned into the OFF state (rather than while the switch is in the process of transitioning into the OFF state). Safety may therefore be improved.

[0014] By clearly and unambiguously indicating the state of the switch (or mechanical switching device incorporating the switch), the contact position indicator may reliably inform a user or operator of the state of the switch and / or the state of the electrical equipment that is used in conjunction with the switch. Armed with this information, the user or operator may follow appropriate procedures, helping to ensure the safety of the user and / or the appropriate operation of the electrical equipment.

[0015] The contact position indicator may further comprise a biasing member, wherein the biasing member is configured to apply a biasing force to the indicator to urge the indicator from the fourth position towards the third position.

[0016] Since the coupler link and the indicator are not physically coupled, the coupler link will not return the indicator to the third position (the coupler link cannot push the indicator in two different directions in the absence of a physical coupling). The use of a biasing member may be a particularly simple and reliable method of ensuring that the indicator does not remain in, or revert to, the fourth position as the coupler link moves from second position to the first position. A biasing member, such as a spring, is a cost-effective and widely available component that may ensure that production costs are kept relatively low compared to the production cost of conventional contact position indicators.

[0017] In urging the indicator towards the third direction, the biasing member may also help ensure that the indicator is maintained in a stable position so that it may reliably indicate the state of the switch. In particular, where the indicator is configured at the third position to indicate that the switch is in the ON state, the biasing force may increase the reliability of such as indication, which may be particularly advantageous for safety reasons.

[0018] The coupler link may be configured to cause the indicator to move from the third position to the fourth position by abutting against the indicator and applying a force on the indicator. Such a feature may provide for a simple and reliable transformation of forces from one component of the contact position indicator to another. Moreover, this arrangement allows for movement of the indicator without the need for any physical joint or coupling between the coupler link and the indicator; by removing such joints, and the resultant wear of the joints, the lifetime of the device may be improved.

[0019] The contact position indicator may be configured so that the coupler link is configured to move between the first position and the second position along a first linear path, and the indicator may be configured to rotate between the third position and the fourth position. Such motions are simple motions that may be designed reliably, effectively and with cost-effectiveness. Moreover, the combination of paths taken by the coupler link and the indicator may help ensure that space constraints for the contact position indicator (e.g., with reference to the footprint of the associated switch) are met and that a contact position indicator that is appropriately compact may be designed.

[0020] Optionally, the coupler link may be configured to cause the indicator to move from the third position to the fourth position using a cam joint or mechanism. For example, the coupler link may comprise a cam surface, and the indicator may comprise a follower surface. As the coupler link moves, the interaction between the cam surface and the follower surface on the indicator causes a resultant movement of the indicator.

[0021] A cam mechanism optionally achieves a conversion between linear and rotatory motions using a simple design that requires few parts, which makes it cheap to construct, easy to assemble, and reliable, and which may furthermore be designed for gaining a mechanical advantage. In other examples, the cam mechanism or cam joint can be configured to convert between other types of motion, depending on the configuration of the device.

[0022] The coupler link may be configured so that when the coupler link is at the first position there is a gap between the indicator and the coupler link. Such a gap may be sufficient for preventing the possible chattering or vibrations of the switch contacts, or other electromagnetic forces that may cause small movements of the components of the switch, from affecting the reliable indication of the state of the switch by the contact position indicator. Moreover, such a gap may be sufficient to ensure that once the indicator begins to move because of the motion of the coupler link, the switch contacts have sufficiently separated from one another that electrical contact is broken between the switch contacts and the switch has already transitioned into an OFF state before the indication of the state given by the indictor changes. The specific gap can depend on the configuration of the device. In some implementations, the gap is of at least: 0.1mm, optionally 0.5mm, optionally 1mm, optionally 2mm, optionally 3mm, optionally 4mm, optionally 5mm. In some specific examples, the gap is at least 2mm. In some implementations, the gap between the indicator and the coupler link is equivalent to a portion of a stroke of the linear slider (i.e. equivalent to a portion of the distance moved by the slider between the ON / OFF positions or states). The gap is optionally three quarters of the stroke, optionally two thirds of the stroke, optionally half the stroke, optionally a third of the stroke, optionally a quarter of the stroke. The gap can be half the stroke in some specific examples. In some implementations, the gap may correspond to a predetermined portion of the distance between the position of the movable electrical contacts in the ON state and the position of the movable electrical contacts in the OFF state within the switching mechanism 220. The gap is optionally three quarters of the distance, optionally two thirds of the distance, optionally half the distance, optionally a third of the distance, optionally a quarter of the distance. The gap can be half the distance in some specific examples.

[0023] Also disclosed herein is a method of using the contact position indicator of the first aspect. A method comprises: moving the coupler link from the first position to the second position; causing, by the coupler link, the indicator to move from the third position to the fourth position; and moving the coupler link from the second position to the first position, wherein, in response to the coupler link moving from the second position to the first position, the indicator moves from the fourth position to the third position. Due to the physical separation between the components, this movement of the indicator from the fourth position to the third position is at least partially independent of the coupler link.

[0024] Another implementation of a method of using the contact position indicator of the first aspect is also described herein. When the coupler link is at the first position, the method comprises: moving the coupler link from the first position to the second position and causing (by the coupler link) the indicator to move from the third position to the fourth position. When the coupler link is at the second position, the method comprises: moving the coupler link from the second position to the first position, wherein, in response to the coupler link moving from the second position to the first position, the indicator moves from the fourth position to the third position. Due to the physical separation between the components, this movement of the indicator from the fourth position to the third position is at least partially independent of the coupler link.

[0025] Also disclosed herein is a system comprising the contact position indicator of the first aspect and a switch. The switch is optionally a mechanical switching device comprising a slider, wherein the slider and the coupler link are coupled. The slider is configured to move between a fifth position and a sixth position, thereby causing the coupler link to move between the first position and the second position. The coupling between the slider and the coupler link may ensure that the coupler link is configured to move between the first position and the second position.

[0026] The slider and the coupler link may be pivotably coupled. Such a coupling can be simple to design and construct. Furthermore, a pivotable coupling instead of a rigid coupling may require less space. This may allow a smaller contact position indicator to be provided.

[0027] The system may further comprise a housing configured to guide the coupler link between the first position and the second position. The use of the housing to guide the coupler link may allow fewer components to be used in the assembly of the contact position indicator, thereby facilitating a simple and cost-effective assembly and production, as well as helping to improve reliability in operation by guiding the coupler link in a repeatable manner.

[0028] The coupler link may form a double slider mechanism, wherein a first end of the coupler link is driven by the slider and wherein a second end of the coupler link contacts the indicator at the second position. A double slider mechanism is a simple and reliable mechanism that may be designed and produced cost-effectively.

[0029] In such an example, where the coupler link forms a double slider mechanism, the second end of the coupler link may be configured to move between the first position and the second position in a first linear path and the slider may be configured to move between the fifth position and the sixth position in a second linear path, wherein the first linear path and the second linear path are not parallel. Linear paths are simple and reliable to design and implement. For example, the slider may be a linear actuator. Furthermore, the fact that the first linear path and the second linear path are not parallel may mean that advantageously less space is required in which to design the paths. A smaller device may therefore be provided. Optionally, the first linear path and the second linear path may be orthogonal to one another, thereby further providing a space efficient arrangement. In another example, the second end of the coupler link is configured to move between the first position and the second position along a curved path, and the slider is configured to move between the fifth position and the sixth position in a linear path.

[0030] The mechanical switching device may further comprise: one or more movable electrical contacts and one or more fixed electrical contacts, wherein the slider is rigidly coupled to the one or more movable electrical contacts. In such examples, when the slider is configured to be at the fifth position the one or more movable electrical contacts are in electrical contact with the one or more fixed electrical contacts and the mechanical switching device is in a first state. When the slider is configured to be at the sixth position the one or more movable electrical contacts are not in electrical contact with the one or more fixed electrical contacts and the mechanical switching device is in a second state. Alternatively, the slider may be configured to be in the fifth position when the mechanical switching mechanism is in the second state, and in the sixth position when the mechanical switching mechanism is in the first state.

[0031] The rigid coupling of the slider to one or more movable electrical contacts allows for provision of a simple coupling mechanism between the switching mechanism of the mechanical switching device and the contact position indicator, thereby helping to increase the reliability of the system.

[0032] The indicator may be configured such that: the indicator being at the third position indicates that the mechanical switching device is in the first state, and the indicator being at the fourth position indicates that the mechanical switching device is in the second state, or vice versa.

[0033] In the relevant examples, the first state of the mechanical switching device may correspond to the ON state and the second state of the mechanical switching device may correspond to the OFF state. It may be advantageous to configure the contact position indicator to indicate that the mechanical switching device is in the ON state when the indicator is at the third position. This is because the third position may be configured to be more stable (particularly in example implementations that employ the biasing member to urge the indicator towards the third position). Also, when the coupler link is at the first position and the indicator is at the third position, the coupler link and the indicator do not touch and are not otherwise coupled, which means that the indication of switch state may be more reliable when the indicator is at the third position. However, in other examples, the mechanical switching device is in the OFF state when the indicator is at the third position.

[0034] In some examples, the contact position indicator may be configured such that the force exerted on the slider at any time during the operation of the contact position indicator is less than IN. This may help ensure that there is little or no excess force on the switch or the switching contacts or the switching mechanism, thereby minimising or avoiding wear of the switch.

[0035] The skilled person will recognise that the features of the device of the first aspect described above may be combined as appropriate, and that optional elements of the first aspect may also be applied to the other aspects. Brief description of the figures

[0036] Figure 1 illustrates a schematic example of a system comprising a mechanical switching device and a contact position indicator.

[0037] Figure 2 provides a schematic illustration of a surface of an example indicator.

[0038] Figures 3A-C provide illustrations of an example contact position indicator in various states or configurations.

[0039] Figures 4A-B provide illustrations from different angles of an example contact position indicator in various states or configurations.

[0040] Figures 5 illustrates an example interaction between the coupler link and the indicator when the coupler link is at the second position and the indicator is at the fourth position.

[0041] Figures 6A-B provide schematic illustrations of an example interaction between an example coupler link and an example indicator whereby a ball and socket mechanism is employed.

[0042] Figure 7 illustrates a close-up head-on view of the coupler link of an example contact position indicator.

[0043] Figures 8A-B illustrate further close up views of the coupler link and its interaction with the housing in an example contact position indicator.

[0044] Figures 9A-C provide schematic illustrations of example slider mechanisms.

[0045] Figures 10A-B provide flowcharts showing example operations for operating an example contact position indicator. Detailed description

[0046] Other advantages and effects of the present disclosure will become readily apparent to those skilled in the art as the following detailed description proceeds by way of illustrative and specific examples as depicted in the Figures.

[0047] The structures, proportions, sizes, etc. shown in the drawings attached hereto are for the purpose of understanding and reading the disclosure only and are not intended to limit the scope of the disclosure in any way. For ease of description, the drawings of the present disclosure accordingly simplify or omit components commonly used in the art, which do not affect the understanding of the present disclosure by those skilled in the art.

[0048] Moreover, where the description refers to an action, such as movement or transition, between two states or positions A and B, this includes the action in both directions, i.e., it includes the action from A to B and the action from B to A.

[0049] With reference to Figure 1, the present disclosure provides a contact position indicator 100, and a system 500 comprising both the contact position indicator 100 and a mechanical switching device 200. The contact position indicator 100 is configured to indicate the state of the mechanical switching device 200. The contact position indicator thus 100 allows an operator or user to determine the state of the mechanical switching device 200. For example, the contact position indicator 100 may provide information to the user as to whether the mechanical switching device 200 is ON or OFF. The means by which the contact position indicator 100 operates may allow for a clear and unambiguous indication regarding the state of the mechanical switching device 200.

[0050] The mechanical switching device 200 may constitute a safety component of the electrical system. The mechanical switching device 200 may act as a safety component in critical safety situations, such as by providing overcurrent protection for the electrical system. Additionally, or alternatively, the mechanical switching device 200 may constitute a means by which the electrical system may be turned OFF in non-critical situations; that is, a means by which the electrical current within the electrical system may be broken or discontinued (for operational or maintenance purposes). Such non-critical situations can include for example the maintenance of the device and / or the installation of other systems which work in conjunction with the switch. The mechanical switching device 200 may be a circuit breaker. Optionally, the mechanical switching device 200 may be a hybrid circuit breaker, ora hybrid semiconductor circuit breaker.

[0051] The mechanical switching device 200 comprises a switching mechanism 220 that is configured to open and / or close the electrical circuit of the electrical system by moving one or more movable electrical contacts in and out of electrical contact with one or more fixed contacts.

[0052] In order to allow the contact position indicator 100 to indicate the state of the switching mechanism 220 (i.e., whether it is in an ON state or an OFF state), the mechanical switching device 200 of Figure 1 comprises a coupling mechanism 210 that couples the switching mechanism 220 to the contact position indicator 100. The coupling mechanism 210 is described herein as a slider, but can be any suitable moveable component. The slider can form part of a linear actuator, or can be otherwise coupled to a linear actuator, as appropriate. Alternatively, the slider 210 may be a part of the switching mechanism 220, and optionally be part of the contacts or form the contacts themselves.

[0053] The contact position indicator 100 comprises a coupler link 110 that is configured to couple to the slider 210 of the mechanical switching device 200. Furthermore, the contact position indicator 100 comprises an indicator 102. The coupler link 110 and the indicator 102 are not physically coupled. The indicator 102 provides the means by which an indication of the state of the mechanical switching device 200 is to be provided to the user in operation. Although not physically coupled to the coupler link 110, the indicator 102 is configured to be in a physical position or configuration proximate to the coupler link 110, so that the position of the indicator 102 is influenced at least in part by the position or state of the coupler link 110. In other words, the indicator 102 is movably coupled to the coupler link 110, as discussed below with reference to Figures 3A-C.

[0054] In particular, the coupler link and the indicator are configured such that movement of the coupler link from a first position to a second position causes the indicator to move from a third position to a fourth position. When the coupler link moves from the second position to the first position, the indicator moves from the fourth position to the third position. When the coupler link is at the first position, the coupler link and the indicator do not touch and are not otherwise physically coupled.

[0055] The coupler link 110 and / or indicator 102 may be formed from a polymer, optionally a plastic. Polymers are cost-effective, abundant, durable, lightweight and safe materials to work with. They have design flexibility and economies of scale, and can be electrically insulating. Alternatively, the coupler link 110 and / or indicator 102 may be constructed from metal or any other material, depending on design requirements.

[0056] The coupler link 110 and / or indicator 102 may be manufactured using an injection moulding process. The advantages of injection moulding include its compatibility with a wide range of materials, its efficiency, repeatability, reliability and importantly the fact that it allows for complex geometries with high tolerances. In other examples, the coupler link 110 and / or indicator 102 may be manufactured using an additive manufacture process (such as 3D printing), compression moulding, vacuum casting, carving or any other suitable method.

[0057] The coupler link 110 is, in use, coupled to the slider 210 and moveably coupled to the indicator 102. The slider is rigidly coupled to the one or more movable electrical contacts of the switching device 200 and is coupled to the coupler link. The slider is configured to move between a fifth position and a sixth position, thereby causing the coupler link to move between the first position and the second position.

[0058] When the slider is at the fifth position, the one or more movable electrical contacts are in electrical contact with the one or more fixed electrical contacts and the mechanical switching device is in a first state. When the slider is at the sixth position, the one or more movable electrical contacts are not in electrical contact with the one or more fixed electrical contacts and the mechanical switching device is in a second state.

[0059] Since the slider, the coupler link and the indicator are coupled or linked as described herein, the state of the switching mechanism 220 may be reflected by the position or configuration of the indicator 102. For example, the indicator 102 may comprise a surface 104 that is configured to visually indicate the position of the indicator 102 to the user or operator, and thereby inform the user or operator of the state of the mechanical switching device 200.

[0060] With reference to Figure 2, the surface 104 of the indicator 102 may comprise in general labels 104a and 104b corresponding to an indication of the state of the mechanical switching device 200. For example, label 104a may be configured to correspond to an OFF state of the mechanical switching device 200 and label 104b may be configured to correspond to an ON state of the mechanical switching device 200, or vice versa.

[0061] The depiction of the labels 104a and 104b in Figure 2 are for illustrative purposes only. The labels 104a and 104b may comprise any other sign that may be comprehensible to the user or operator. For example, the labels 104a and 104b may comprise numerals, such as "0" and "1", or words or one or more letters, such as "ON" and "OFF", or "SAFE" and "DANGER", or any other symbol. In addition, or alternatively, the labels 104a and 104b may comprise colour signs, such a green label or a red label.

[0062] While the description and the Figures generally refer to binary states of e.g., ON and OFF or labels 104a and 104b, more general possibilities are envisaged. For example, the switching mechanism 220 may comprise more than two states, which together correspond to the state of a plurality of circuits controlled by the mechanical switching device 200 and / or which indicate an earthed or other (stable) intermediate position between ON and OFF.

[0063] In Figures 3A-C, an example contact position indicator 100 in accordance with Figure 1 is illustrated in three different configurations. Figures 4A-B provide different views of the example contact position indicator 100.

[0064] With reference to Figures 3A-C, the contact position indicator 100 may be used to indicate the state of switch 200. The contact position indicator 100 comprises an indicator 102 and a coupler link 110. The coupler link 110 and the indicator 102 are configured such that movement of the coupler link 110 from a first position to a second position causes the indicator 102 to move from a third position to a fourth position. When the coupler link 110 moves from the second position to the first position, the indicator 102 is configured to move from the fourth position to the third position. When the coupler link 110 is at the first position, the coupler link 110 and the indicator 102 do not touch and are not otherwise coupled.

[0065] In the configuration illustrated in Figure 3A, the coupler link 110 is in the first position and the indicator 102 is in the third position. In the configuration illustrated in Figure 3C, the coupler link 110 is in the second position and the indicator 102 is in the fourth position. Figure 3B shows an intermediate or transitory configuration between the configuration of Figure 3A and the configuration of Figure 3C. In operation, the configuration of the contact position indicator 100 is configured to change from that illustrated in Figure 3A to that illustrated in Figure 3C via the transitory configuration illustrated in Figure 3B, and vice versa, i.e., from that illustrated in Figure 3C to that illustrated in Figure 3A via a transitory configuration illustrated in Figure 3B. In transitioning from the configuration illustrated in Figure 3A to that illustrated in Figure 3C, the coupler link 110 moves from the first position towards the second position. The coupler link can be driven by any suitable component to move the indicator. Optionally the coupler link is driven by the slider discussed above.

[0066] With reference to Figure 3A, when the coupler link 110 is in the first position, there is a gap 170 between the coupler link 110 and the indicator 102. Therefore, the coupler link 110 and the indicator 102 do not touch when the coupler link is in the first position. The gap 170 may be at least 2mm. Alternatively, the gap 170 may be at least: 0.1mm, optionally 0.5mm, optionally 1mm, optionally 2mm, optionally 3mm, optionally 4mm, optionally 5mm. In the embodiment illustrated in Figures 3A-C, the gap is 2.3mm.

[0067] The coupler link 110 may be supported and / or guided in its motion (between the first and second positions) to follow a particular path by structures formed within, or engineered into, a housing 140 of the system. For example, the portions 160a and 160b may be configured to at least partially constrain the coupler link 110, or equivalently the second end 116 of the coupler link 110, to move along a pre-determined path. For example, the coupler link 110, or more precisely the second end 116 of the coupler link 110, may follow a curved path or a linear path, e.g., a linear path in a direction 304. Alternatively, any other suitable structures within the housing can be used I provided to constrain the coupler link 110 and / or support the coupler link.

[0068] As the coupler link 110 moves from the first position towards the second position, the gap between the coupler link 110 and the indicator 102 becomes smaller. When the contact position indicator 100 is in the transitory configuration as illustrated in Figure 3B, the gap 170 closes and the coupler link 110 abuts against the indicator 102. Once the coupler link abuts the indicator, the coupler link 110 begins to apply a force on the indicator 102 as it moves further along its path towards the second position, e.g., moves in the direction 304. The force applied on the indicator 102 by the movement of the coupler link causes the indicator to move from the third position to the fourth position.

[0069] In other words, with reference to Figure 3B, as the coupler link 110 moves towards the second position it causes the indicator 102 to move from the third position towards the fourth position. In the embodiment illustrated in Figures 3A-C, the indicator 102 rotates from the third position to the fourth position about a pivot point 108 that may be fixedly coupled to the housing 140. More generally, the indicator 102 may be configured to move in a linear path or a more general curved path.

[0070] In the embodiment illustrated in Figures 3A-C, the coupler link 110 abuts against the indicator 102 above the pivot point 108. Alternatively, the contact position indicator 100 may be configured so that coupler link 110 abuts against the indicator 102 below the pivot point 108.

[0071] The mechanism by which the coupler link 110 is configured to cause the indicator 102 to move from the third position to the fourth position may be a cam mechanism. For example, the coupler link 110 may comprise a cam surface, and the indicator 102 may comprise a follower surface. As the coupler link 110 moves, the interaction between the cam surface and the follower surface on the indicator 102 causes the resultant movement of the indicator 102. In this manner, the motion of the coupler link 110 (from the first position to the second position) transforms into the motion of the indicator 102 (from the third position to the fourth position). A cam joint or mechanism is an example of how the coupler link and the indicator may be movably coupled, but without the components being physically coupled when the coupler link is in the first position.

[0072] The cam surface may be the second end 116 of the coupler link 110. Alternatively, in some examples, the coupler link 110 comprises a member 118 that protrudes from second end 116 of the coupler link 110. The member 118 may protrude in a substantially orthogonal direction to the axis of the coupler link 110. In such examples, the cam surface may comprise member 118. That is, the coupler link 110 may be configured to abut against the indicator 102 via the member 118 in the transitory configuration as illustrated in Figure 3B.

[0073] When the coupler link 110 reaches the second position, the indicator 102 reaches the fourth position. At this point, the contact position indicator 100 is in the configuration illustrated in Figure 3C.

[0074] The contact position indicator 100 is also configured to perform the reverse of operations discussed above; namely transition from the configuration illustrated in Figure 3C to that illustrated in Figure 3A via the transitory configuration illustrated in Figure 3B.

[0075] With reference to Figure 3C, the coupler link 110 is configured to move from the second position to the first position. When the coupler link 110 moves from the second position to the first position, the indicator 102 is configured to move from the fourth position to the third position. This movement can be a result of e.g., the cam mechanism described above. For example, the indicator follower surface can continue to follow the cam surface as the coupler link moves, even though no physical force is being applied to the indicator by the coupler link. In this way, movement of the indicator from the fourth position to the third position can be considered to be at least partially independent of the coupler link.

[0076] In some examples, a biasing member 107 is configured to apply a biasing force to the indicator 102. The biasing member 107 may be a tension spring or a compression spring, or any other resiliently deformable component which is resilient through form and / or material. The biasing force may urge the indicator 102 from the fourth position to the third position as the coupler link 110 moves from the second position to the first position.

[0077] The biasing member 107 may be loaded in the fourth position and unloaded in the third position. Alternatively, the biasing member 107 may be also loaded in the third position (for example, there may be some force present due to the assembly position) and configured to apply a biasing force to the indicator to keep it in the third position.

[0078] With reference to Figure 3B, as the coupler link 110 moves towards the first position, the indicator 102 reaches the third position and stops moving. At this point the coupler link 110 abuts against the indicator 102. However, the coupler link 110 does not apply any force on the indicator 102.

[0079] The indicator 102 may remain at the third position due to the absence of any force on it. Alternatively, the indicator 102 may be held at the third position by the balancing of a biasing force from the biasing member 107 and the reaction force from a component of the housing 140 against which the indicator 102 abuts.

[0080] The coupler link 110 continues to move towards the first position, which opens up a gap (or physical distance) between the coupler link 110 and the indicator 102. With reference to Figure 3A, when the coupler link 110 reaches the first position the gap 170 between the coupler link 110 and the indicator 102 is maintained.

[0081] The contact position indicator 100 is, in use, part of a system 500 that also comprises a switch 200 (optionally a mechanical switching device 200). The coupler link can be coupled to, and driven by, the switch 200 in any suitable manner such that the indicator provides an indication of the state of the switch.

[0082] With specific reference to Figure 3A, the switch is a mechanical switching device 200. The contact position indicator 100 is coupled at a first end 114 to the mechanical switching device 200 via a slider 210 that may protrude from the mechanical switching device 200. In some examples, the first end 114 of the coupler link 110 is rigidly coupled to the slider 210. In the embodiment illustrated in Figures 3A-C, the first end 114 of the coupler link 110 is pivotably coupled to the slider 210, optionally with a pin joint.

[0083] The slider 210 is configured to move between a fifth position and a sixth position, thereby causing the coupler link 110 to move between the first position and the second position. The slider 210 may be configured to be in the fifth position when the mechanical switching device is in the ON state and to be in the sixth position when the mechanical switching device is in the OFF state, or vice versa.

[0084] With reference to Figure 3A, the path traversed by the slider 210 may be linear in a direction 302, or any other appropriate path. In examples where the slider 210 is configured to follow a linear path in a direction 302, and the coupler link 110 is configured to follow a linear path in a direction 304, the direction 302 may be configured to be non-parallel to direction 304. Optionally, direction 302 may be orthogonal to direction 304.

[0085] With reference to the configuration Figure 3A, the contact position indicator 100 may be said to be in a configuration that corresponds to the ON state of the mechanical switching device 200, where Figure 3C illustrates the OFF state. Alternatively, the mechanical switching device 200 may be in the OFF state in the configuration of Figure 3A, where Figure 3C illustrates the ON state.

[0086] The contact position indicator 100 is configured to visually indicate one of the labels 104a or 104b on the surface 104 of the indicator 102 to the user depending on the state of the mechanical switching device 200. An indication of the state of the mechanical switching device 200 may be given to the user via a window 150 of the housing 140. In particular, the window 150 may allow a part of the surface 104 of the indicator 102 to be viewable to the user, said part indicating the state of the switching device 200.

[0087] As the mechanical switching device 200 changes state between the ON state and the OFF state, the slider 210 is configured to move between the fifth position and the sixth position. This in turn causes the coupler link 110 to move between the first position and the second position. The movement of the coupler link 110 causes or influences the indicator 102 to move between the third position and the fourth position. As the indicator 102 moves, the label on the surface 104 of indicator 102 moves in relation to the window 150. Thus, depending on the position of the indicator 102 a different label is viewable by the user through the window 150.

[0088] This process is described in further detail with reference to Figures 4A-B, which provide different views of the system 500 illustrated in Figures 3A-C.

[0089] Figure 4A provides a head-on view and a "top" view of the system 500 in the same configuration as that illustrated in Figure 3B, i.e., the state at which the indicator 102 is at the third position and the coupler link 110 abuts against the indicator 102, but does not apply any force on it. This configuration corresponds to a transitory state that is reached between the ON and OFF transitions of the mechanical switching device 200.

[0090] At this point, as at the point corresponding to the configuration illustrated in Figure 3A, the surface 104 of the indicator 102 is aligned with the window 150 so that the label 104b is visible to the user. The label 104a is not visible to the user (i.e., it is outside the window 150 and hidden by the housing 140). In this specific example configuration, the mechanical switching device 200 is in the ON state.

[0091] Figure 4B provides a head-on view and a "top" view of the system 500 in the same configuration as that illustrated in Figure 3C, i.e., the state at which the indicator 102 is at the fourth position and the coupler link 110 is at the second position. The surface 104 of the indicator 102 is so aligned with the window 150 that the label 104a is visible to the user. The label 104b is not visible to the user (i.e., it is outside the window 150 and hidden by the housing 140). In this specific example configuration, the mechanical switching device 200 is in the OFF state.

[0092] Figure 5 illustrates an expanded head-on view of the configuration of the indicator 102 at the fourth position and the configuration of the coupler link 110 at the second position. This corresponds to the configuration illustrated in Figure 3C and Figure 4B.

[0093] With reference to Figure 5, at the equilibrium position illustrated therein, in which the indicator 102 is at the fourth position and the coupler link 110 is at the second position, the biasing member 107 applies a biasing force on indicator 102. At the fourth position of the indicator, the force exerted by the coupler link 110 on the indicator 102 exceeds the biasing force. Indeed, the skilled person will understand that the force exerted by the coupler link as a result of the movement of the slider is always higher than biasing spring force to allow the indicator to move from the third position to the fourth position.

[0094] However, when the coupler link 100 moves from the second position to the first position, the force it exerts on the indicator is removed. The biasing force applied on the indicator 102 thus allows the indicator 102 to move from the fourth position to the third position when the coupler link 110 moves from the second position to the first position.

[0095] Optionally, the biasing member 107 may also apply a biasing force that maintains the indicator 102 at the third position. Such a configuration may allow for a fail-safe mechanism. Thus, even if the mechanism otherwise fails, the indicator 102 may be configured to move to the third position and remain at the third position. This may ensure that the contact position indicator 100 will indicate, for example, that the mechanical switching device 200 is in an ON state (even if the device is actually OFF), thereby helping to ensure user safety even after a failure of the contact position indicator 100.

[0096] Moreover, the use of a biasing member 107 facilitates the provision of gap 170 between the couple link 110 and the indicator 102 when the coupler link 110 is in the first position. This is because the biasing force applied by the biasing member 107 urges the indicator 102 from the third position to the fourth position. Thus, the coupler link 110 and the indicator 102 need not be fixedly or physically coupled.

[0097] Other mechanisms that allow the indicator 102 to move from the fourth position to the third position and yet facilitate a gap between the coupler link 110 and the indicator 102 when the coupler link 110 is at the first position are possible. Such examples may employ a temporary coupling between the coupler link 110 and the indicator 102, which temporary coupling is configured such that there is no physical coupling between the coupler link and the indicator when the coupler link is at the first position.

[0098] With reference to Figures 6A-B, one possibility is to use a ball and socket mechanism. Namely, the coupler link 110 may comprise a ball 110a and the indicator 102 may comprise a socket 106a (or vice versa). The ball 110a may be positioned on the second end 116 of the coupler link 110. The socket 106a may be compliant.

[0099] In operation, when the coupler link 110 moves along the path from the first position towards the second position, the ball 110a may abut against the socket 106a. The ball 110a may apply a force on the socket 106a so as to move the indicator 102 from the third position to the fourth position. When the indicator 102 is about to reach the fourth position, the indicator 102 may abut against a first portion of the housing 140. The first portion may provide a reaction force against the force applied by the coupler link 110. At this point the reaction force from the first portion of the housing 140 may force the ball 110a into the compliant socket 106a. Once the ball 110a is in the socket 106a, the coupler link 110 may be said to be at the second position and the indicator 102 may be said to be at the fourth position. [OO1OO] When the process is reversed the coupler link 110 is configured to move from the second position to the first position. As the coupler link 110 moves along the reverse trajectory, the ball 110a is configured to remain coupled to the socket 106a. The ball 110a applies a force on the indicator 102, thereby causing the indicator 102 to rotate from the fourth position towards the third position. [OO1O1] The indictor 102 may be configured such that when it reaches the third position, the indicator 102 may abut against a second portion of the housing 140. The second portion of the housing 140 may apply a reaction force against the force applied by the coupler link 110 on the indicator 102. As a result of the reaction force from the second portion of the housing 140, the compliant socket 106a may be configured to decouple from the ball 110a.

[00102] At this point the coupler link 110 may continue to follow its predetermined path towards the first position, while the indicator 102 remains at the third position. Where there is no biasing member 107, the indicator 102 may be configured to remain at the third position (instead of rotating back to the fourth position) using e.g., a frictional force of the pivot point 108 and / or by an appropriate configuration of the centre of mass of the indictor 102.

[00103] Another possible mechanism for maintaining a gap 170 between the coupler link 110 and the indicator 102 when the coupler link 110 is configured to be at the first position is a double hook mechanism or the use of permanent magnets attached to the second end 116 of the coupler link 110 and an appropriate position on the indicator 102. It will be understood that any suitable means may be used in place of the above-described biasing member.

[00104] The gap 170 between the coupler link 110 and the indicator 102 may ensure that any unwanted and / or temporary / transitory movements of the electrical contacts within the switching mechanism 220 of the mechanical switching device 200 do not affect the indication given by the contact position indicator 100.

[00105] For example, the switching mechanism 220 may display a phenomenon known as "chattering", whereby the switching mechanism 220 oscillates between the OFF state and an intermediate state for a short period of time, where the intermediate state is between the ON state and the OFF state, usually after it is initially switched ON. This phenomenon may be caused by a variety of factors including the properties of the power supply. The chattering may cause the slider 210 to move, which may thereby cause the coupler link 110, to which it may be directly coupled, to move. The gap 170 may ensure that any such movement of the coupler link 110 does not cause a resulting movement of the indicator 102, thereby avoiding a false indication of the state of the mechanical switching device 200 from being given to the user. Once the contacts reach the ON state, the system stabilizes and there is no further movement in the contacts due to the contact force.

[00106] Furthermore, the gap 170 allows that the indication provided by the contact position indicator 100, when the indicator 102 moves from the third position to the fourth position, is delayed. That is, the indication only begins to change some time after the mechanical switching device 200 changes state, e.g., changes from the ON state to the OFF state. Therefore, in addition to the technical advantage of the gap 170 as described above in relation to chattering, the gap 170 provides a further technical advantage from a safety perspective. In order to allow such technical benefits to be provided, the gap may correspond to a predetermined portion of the distance between the position of the movable electrical contacts in the ON state and the position of the movable electrical contacts in the OFF state within the switching mechanism 220 (optionally three quarters of the distance, optionally two thirds of the distance, optionally half the distance, optionally a third of the distance, optionally a quarter of the distance). In some examples, the gap may correspond to half the distance between the position of the movable electrical contacts in the ON state and the position of the movable electrical contacts in OFF state within the switching mechanism 220. Optionally, the gap 170 may be configured to be at least 2mm when the coupler link 110 is at the first position. In some specific embodiments, the gap 170 is configured to be 2.3mm when the coupler link 110 is at the first position.

[00107] Returning to the specific example illustrated in Figure 5, when the coupler link 110 is at the second position the biasing member 107 applies a biasing force on indicator 102, as discussed above. This biasing force translates to a force on the coupler link 110, which in turn may be fully or partially transferred along the axis of the coupler link 110 and transferred therefrom onto the slider 210. The force applied on the slider 210 may then transfer onto a force applied on the switching mechanism 220. In particular, this may result in a force being applied onto the one or more movable electrical contacts.

[00108] For safety reasons, in general, a force of magnitude greater than 1.5N should not be applied on the switching mechanism 220 of the mechanical switching device 200. In the embodiment illustrated in Figures 3A-C, of which an expanded view is provided in Figure 5, the resultant force on the slider 210 may be less than IN throughout the transitioning and equilibrium process, i.e., when the contact position indicator 100 is in use. This may help ensure that damage to the mechanical switching device 200 is prevented. Also, this may help ensure that the velocity of the movable electrical contacts of the switching mechanism 220 is not affected during the transition from the ON state to the OFF state (i.e. opening velocity of contacts is not affected).

[00109] With reference to Figure 7, the mechanism by which force is transferred from the slider 210 to the indicator 102 via the coupler link 110 in transitioning from the configuration illustrated in Figure 3A to the configuration illustrated in Figure 3C may be that of a double slider mechanism.

[00110] In particular, the coupler link 110 may form a double slider mechanism. The first end 114 of the coupler link 110 may be viewed as the first node of the double slider mechanism. The second end 116 of the coupler link 110 may be viewed as the second node of the double slider mechanism. The body of the coupler link 110 may be viewed as the rigid link of the double slider mechanism. The first end 114 of the coupler link 110 may be driven by the slider 210. The second end 116 of the coupler link 110 may contact the indicator 102 and apply a force thereon in moving from the first position to the second position.

[00111] The first end 114 of the coupler link 110 may be constrained to move along a path that is determined by the motion of the slider 210. For example, the slider 210 may move along the direction 302 and in so doing constrain the first end 114 of the coupler link 110 via the coupling 120 to move in the direction 302.

[00112] Where the coupler link 110 is pivotably coupled to the slider 210 at the first end 114, as the first end 114 is driven by the slider 210, the motion of the second end 116 may be constrained by structures, components, or portions 160a and 160b built into, formed into, or engineered into the housing 140. For example, the second end 116 may be constrained to move along the direction 304.

[00113] Portions of the housing 140 may act so as support the coupler link 110, and / or guide the motion of the coupler link 110 and in so doing guide the motion of the second end 116 of the coupler link 110. For example, portion 160a is configured to support the coupler link 110 in stationary configurations and when moving (i.e. between the third and fourth positions). Portion 160a may also help guide the coupler link 110 when the coupler link 110 is being driving by the slider 210. Portion 160b is also configured to perform the function of guiding the motion of the coupler link 110.

[00114] Figures 8A-B provide further illustrations of an example contact position indicator 100 with the structures or portions of the housing 140 highlighted.

[00115] With reference to Figure 8A, portions 160a and 160b may be designed in relation to the indicator 102 to guide the second end 116 of the coupler link 110 and cause the second end 116 of the coupler link 110, or alternatively the member 118, to make contact with (or abut against) the indicator 102 and to drive the indicator 102 (by applying a force) when transitioning from the configuration illustrated in Figure 3B to the configuration illustrated in Figure 3C.

[00116] With reference to Figure 8B, there may be a number of portions, for example portions 160a, 160b, 160c that help ensure that the path that the second end 116 of the coupler link 110 moves along is pre-determined to an appropriate level of accuracy and precision. Such a level of accuracy and precision may correspond to that required for the contact position indicator 100 to fulfil its function of indicating the state of the mechanical switching device 200 clearly and unambiguously, and in a reliable and repeatable manner.

[00117] Figures 9A-C provide schematic illustrations of how the coupler link 110 may form a slider mechanism and give examples of the type of paths that the second end 116 may be constrained to move along, both linear and curved. For simplicity, Figures 9A-C illustrate the first node or first end 114 as moving along a linear path 310. Of course, other possibilities may be envisaged including the first end 114 moving along a curved or piecewise path.

[00118] Figure 9A illustrates the second end 116 as being constrained to move along a linear path 320 that is orthogonal to the path 310. Figure 9B illustrates the second end 116 as being constrained to move along a linear path 330 that is nonparallel to the path 310. Figures 9A, 9B are some examples of how the coupler link may form a double slider mechanisms. Figure 9C illustrates the second end 116 as being constrained to move along a linear path 340 that is curved. Other more general possibilities are envisaged, including the second end 116 being configured to move along a piecewise path.

[00119] Figures 10A-B provide flowcharts showing example operations for operating a contact position indicator 100 as described herein.

[00120] With reference to Figure 10A, a method performed when the coupler link is in the first position is described. In particular, operation 1001 comprises, moving the coupler link 110 from the first position to the second position. Operation 1005 comprises, causing (by the coupler link 110) the indicator 102 to move from the third position to the fourth position.

[00121] With reference to Figure 10B, a method performed when the coupler link is in the second position is described. In particular, operation 1003 comprises, moving the coupler link 110 from the second position to the first position. In operation 1007, in response to the coupler link 110 moving from the second position to the first position, the indicator 102 moves from the fourth position to the third position.

[00122] It should be realised that the foregoing embodiments are not to be construed as limiting and that other variations, modifications and equivalents will be evident to those skilled in the art and are intended to be encompassed by the claims unless expressly excluded by the claim language.

[00123] Moreover, the disclosure of the present application should be understood to include any novel features or any novel combination of features either explicitly or implicitly disclosed herein or in any generalisation thereof. Claims may be formulated to cover any such features and / or combination of such features derived therefrom.

Claims

1. A contact position indicator (100) for a switch (200), comprising: an indicator (102); and a coupler link (110), wherein the coupler link and the indicator are configured such that: movement of the coupler link from a first position to a second position causes the indicator to move from a third position to a fourth position, and when the coupler link moves from the second position to the first position, the indicator moves from the fourth position to the third position, andwherein, when the coupler link is at the first position, the coupler link and the indicator do not touch and are not otherwise physically coupled.

2. The contact position indicator of claim 1, wherein the contact position indicator further comprises a biasing member (107), wherein the biasing member is configured to apply a biasing force to the indicator to urge the indicator from the fourth position towards the third position.

3. The contact position indicator of claim 1 or 2, wherein the coupler link is configured to cause the indicator to move from the third position to the fourth position by abutting against the indicator and applying a force on the indicator.

4. The contact position indicator of any one of the preceding claims, wherein: the coupler link is configured to move between the first position and the second position along a first linear path; andthe indicator is configured to rotate between the third position and the fourth position.

5. The contact position indicator of any one of the preceding claims, wherein the coupler link is configured to cause the indicator to move from the third position to the fourth position using a cam mechanism.

6. The contact position indicator of any one of the preceding claims, wherein there is a gap (170) between the indicator and the coupler link when the coupler link is at the first position.

7. A method of using the contact position indicator of any one of the preceding claims, wherein the method comprises:moving (1001) the coupler link from the first position to the second position;causing (1005), by the coupler link, the indicator to move from the third position to the fourth position; andmoving (1003) the coupler link from the second position to the first position, wherein, in response to the coupler link moving from the second position to the first position, the indicator moves (1007) from the fourth position to the third position.

8. A system comprising:the contact position indicator of any one of claims 1-6; anda mechanical switching device (200) comprising a slider (210), wherein the slider and the coupler link are coupled,wherein the slider is configured to move between a fifth position and a sixth position, thereby causing the coupler link to move between the first position and the second position.

9. The system of claim 8, wherein the slider and the coupler link are pivotably coupled.

10. The system of claim 9, wherein the system further comprises a housing (140) configured to guide the coupler link between the first position and the second position.

11. The system of claim 10, wherein the coupler link forms a double slider mechanism, wherein a first end of the coupler link is driven by the slider and wherein a second end of the coupler link contacts the indicator at the second position.

12. The system of claim 11,wherein the second end of the coupler link is configured to move between the first position and the second position in a first linear path;wherein the slider is configured to move between the fifth position and the sixth position in a second linear path; andwherein the first linear path and the second linear path are not parallel; and optionally,wherein the first linear path is orthogonal to the second linear path.

13. The system of any one of claims 8-12, wherein the mechanical switching device further comprises:one or more movable electrical contacts; andone or more fixed electrical contacts;wherein the slider is rigidly coupled to the one or more movable electrical contacts; andwherein, when the slider is configured to be at the fifth position the one or more movable electrical contacts are in electrical contact with the one or more fixed electrical contacts and the mechanical switching device is in a first state, andwherein, when the slider is configured to be at the sixth position the one or more movable electrical contacts are not in electrical contact with the one or more fixed electrical contacts and the mechanical switching device is in a second state.

14. The system of claim 13, wherein the indicator is configured such that:the indicator being at the third position indicates that the mechanical switching device is in the first state; andthe indicator being at the fourth position indicates that the mechanical switching device is in the second state.

15. The system of any one of claims 8-14, wherein the contact position indicator is configured such that the force exerted on the slider at any time during the operation of the contact position indicator is less than IN.

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