AU2011200241A1 - Switch - Google Patents

Abstract

A push button adaptor for a rocker-type switch comprises a body. A push button assembly located in the body comprises a push button. A first depression of the push button actuates the rocker-type switch to turn the switch on, while a second depression of the push button actuates the rocker-type switch to turn the switch off. 25416701 (GHMatters) 20/01/11 Fig. 1 Fig. 2

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant(s): Legrand Australia Pty Ltd Invention Title: SWITCH The following statement is a full description of this invention, including the best method for performing it known to me/us: - 2 PUSH BUTTON ADAPTOR FOR ROCKER-TYPE SWITCH Technical Field The present invention relates generally to a push button 5 switch adaptor and more particularly, but by no means exclusively, to an adaptor used to convert a rocker-type switch to a push button switch. Background of the Invention 10 Perhaps the most common form of electrical switch found in homes and businesses today is the rocker-type switch. As the name suggests, rocker-type switches employ a rocker mechanism which actuates a striker plate for turning the 15 switch on and off. Commonly, the striker plate pivots about a centrally located horizontal axis such that when pivoted in one direction the strike plate contacts a first set of electrical poles to turn an electrically coupled device on, or pivots in an opposite direction to contact 20 another set of poles for turning the electrically coupled device off. Summary of the Invention 25 In accordance with a first aspect of the present invention there is provided a push button adaptor for a rocker-type switch, the adaptor comprising: a body; and a push button assembly located in the body and 30 comprising a push button, such that a first depression of the push button actuates the rocker-type switch to turn the switch on and a second depression of the push button actuates the rocker-type switch to turn the switch off. 35 In an embodiment the push button assembly comprises a pivotable member which, in use, engages a movable contact of the rocker-type switch. 25416701 (GHMatters) 20/01/11 - 3 In an embodiment the pivotable member comprises a cavity arranged to receive a free end of the movable contact, the cavity extending inwardly toward a pivot point of the s pivotable member. In an embodiment the adaptor further comprises a coil spring which seats on an end of the movable contact and provides a bias force on the pivotable member. The coil io may be housed within the cavity. In an embodiment an internal wall of the cavity comprises generally rounded or chamfered outer ends. 15 In an embodiment the first depression of the push button causes the pivotable member to pivot to a first position thereby causing the movable contact to move to one side to electrically contact a first set of poles for turning the switch on. 20 In an embodiment the second depression of the push button causes the pivotable member to pivot to a second position thereby causing the movable contact to move to another side to electrically contact a second set of poles for 25 turning the switch off. In an embodiment the push button assembly further comprises an engaging member coupled to the push button, the engaging member operable to engage a raised side of 30 the pivotable member as the push button is depressed to change the pivot position. In an embodiment the engaging member is a swinging piston, a head of the swinging piston being operable to swing in 35 the direction of the raised side of the pivotable member during engagement. 25416701 (GHMatters) 20/01/11 - 4 In an embodiment the swinging piston is shaped in the form of a mallet. In an embodiment the push button assembly further 5 comprises a spring plate arranged to centre the swinging cam after the pivotable member has disengaged from the pivotable member. In an embodiment the adaptor further comprises a spring 10 arrangement arranged to impart a constant outward force on the push button. In an embodiment the spring arrangement comprises at least one coil spring which, when fully unloaded, causes the is push button to partially project out of an aperture defined in an upper end of the body. In an embodiment the push button arrangement further comprises a retaining arrangement arranged to prevent the 20 push button from partially projecting out of the aperture when in a particular one of the on or off states. In an embodiment the retaining arrangement comprises an arm extending from the pivotable member at one side 25 thereof toward the push button, the arm arranged to be located in a retaining cavity defined in a wall of the push button as the push button is depressed to turn the switch off, such that as the push button is released the arm seats in a grove defined in the retaining cavity to 30 prevent the push button from partially projecting out of the aperture. In an embodiment, upon the push button being depressed a second time thereby causing the pivotable member to pivot, 35 the arm unseats from the grove and, as the push button is released, escapes out of the channel to thereby allow the push button to project partially out of the body. 25416701 (GHMatters) 20101/11 - 5 In an embodiment the adaptor further comprises a colour indicator located on a wall of the push button which is visible when the push button partially extends out of the 5 aperture. In accordance with a second aspect of the present invention there is provided a kit for a push button switch, the kit comprising a push button switch adaptor in io accordance with the first aspect, and a rocker-type switch comprising a movable contact arranged to be moved by the pivotable member for turning the switch on or off. In accordance with a third aspect the present invention i5 provides a method of fitting a push button assembly in accordance with the first aspect, to a rocker-type switch comprising a rocker coupled to a movable contact within the rocker-type switch and arranged to move the movable contact between one of a first and second position for 20 turning the switch on or off, the method comprising: removing the rocker; and coupling the push button assembly to the rocker-type switch such that the pivotable member receivingly engages the movable contact. 25 Brief Description of the Drawings Embodiments of the invention are hereafter described, by way of example only, with reference to the accompanying 30 drawings, in which: Figure 1 is an exploded view of a push button adaptor, in accordance with an embodiment of the present invention; 35 Figure 2 is an exploded view of the Figure 1 push button adaptor in combination with an accompanying rocker-type switch according to an embodiment; 25416701 (GHMatters) 20/01/11 - 6 Figure 3a is a side view of the Figure 1 push button adaptor; 5 Figure 3b is a side view of the Figure 1 push button adaptor coupled to the rocker-type switch shown in Figure 2; Figure 4 is a cross-sectional view of Figure 2; 10 Figure 5 is a cross-sectional perspective view of the push button adaptor assembly shown in Figure 2, coupled to a cover plate; 15 Figures 6a and 6b show a progression of cross-sectional side views illustrating an off and on operation respectively of the push button adaptor assembly of Figure 2; and 20 Figure 7 shows isometric views of the push button adaptor coupled to a face plate in various on and off states. Description of Embodiments Embodiments of the present invention relate to a push 25 button adaptor which may be fitted to a rocker-type switch for converting operation of the rocker-type switch to a push button operation. With reference to Figure 1, there is shown a push button 30 adaptor 10 in accordance with an embodiment of the present invention. The adaptor 10 comprises a body 12 which is arranged to couple to a rocker-type switch body 14, as generally shown in Figure 3b. It will be noted that the push button adaptor body 12 comprises a bottom section 35 which couples to the rocker body 14 and a top section for securing to a faceplate 40 (see Figure 5). The adaptor body 12 and rocker body 14 are preferably made of an 25416701 (GHMatters) 20101111 - 7 insulating material such as a plastic or the like. In more detail, and with additional reference to Figure 2, the bottom section is shaped so as to closely receive an 5 upper section of the rocker body 14. A plurality of openings 15 receive securing lugs 17 (ordinarily arranged to secure the rocker body to the face-plate) carried by the rocker body 14. A corresponding number of securing lugs 19 are provided on the top section of the adaptor io body 12 for securing the adaptor body 12 to the faceplate 40. The securing lugs 17, 19 may, for example, snap lock into the corresponding openings provided in the adaptor body/faceplate. is A push button assembly is located within the adaptor body 12 and comprises a single push button 16. The assembly is configured such that a first depression of the push button 16 actuates the rocker-type switch to turn the switch "on", while a second depression of the push button 20 16 actuates the rocker-type switch to turn the switch "off". In more detail, the push button assembly further comprises a pivotable member in the form of a rocker 18. The rocker 25 is arranged to pivot about a pivot point 20, so as to rock from a first position to a second position. This is best shown in Figures 6a and 6b, illustrating an "on" and "off" push button operation. Defined in an underside of the rocker 18 is a cavity 22 which is arranged to receive both 30 a free-end of a movable contact 24 associated with the rocker-type switch and a dolly spring which is received over the contact 24 (see cut-out of Figure 5). As will be evident from the following description, the cavity 22 effectively acts as a mechanical break. 35 In the illustrated embodiment, the movable contact is in the form of a striker 24 which is pivotally mounted on a 25416701 (GHMatters) 20101/11 - 8 central contact pole 60. The striker 24 is movable between two stable positions or "states" to selectively make electrical contact with poles 62, 64 on either side of the central contact pole 60 (i.e. for making or s breaking an electrical circuit for turning an electrically coupled device on or off, as is well understood by persons skilled in the art). In this regard, the free end of the striker 24 comprises a stem which carries the coil spring 25 and which extends inwardly into the cavity 22 (i.e. 10 towards the pivot point 20). As the rocker 18 moves past the pivot point the coil spring 25 acts on the stem causing the striker 24 to move to the desired state. The coil spring 25 also acts to provide the necessary bias for providing the aforementioned stability. 15 During the switch of certain loads (e.g. where an inrush of current is experienced which exceeds the rated current), the moving and fixed contacts of the striker 24 may weld together. In this case, the pressure applied by 20 the spring 25 may not be sufficient to break the weld and throw the contact. The cavity walls may thus advantageously apply the additional force required to cause the moving striker to switch. Outer ends of the cavity 22 may be rounded or chamfered for smooth actuation 25 of the striker 24, as shown in Figure 4. In order to actuate the rocker 18, the push button assembly comprises an engaging member 28 in the form of a swinging piston 28 that swingingly couples to an inwardly 30 facing (i.e. non-showing) surface of the push button 16. In the illustrated embodiment, the piston 28 is shaped generally in the form of a mallet. A length of the mallet head 30 is such that as the push button 16 is depressed, the mallet head is arranged to engage a raised side of the 35 rocker 18 at or near a corresponding end of the head 30. As the push button 16 continues to be depressed, the inward force translates through the mallet head 30 to the 25416701 (GHMatters) 20/01/11 - 9 rocker 18 pushing down on the raised end and thereby causing the rocker 18 to pivot to the opposing side (in turn actuating the striker 24). During operation, the head may swing in the direction of the raised end of the s rocker, again to achieve smooth operation. A spring plate 32 is provided to centre the head 30 between depressions of the push button 16. As previously described, the push button adaptor 10 10 described herein is operable between two states, namely an "on" state and "off" state. As is evident from Figure 7, while the switch is in the on state, the push button partially extends through an opening 38 in the body 12, while in the off state the button sits flush with the is opening (or faceplate 40, as is the case in Figure 7). In order to achieve this operation, one or more springs are positioned within the body 12 (in the illustrated embodiment four coil springs 44 are utilised) and are 20 operable to apply a constant outward force on the push button 16. To prevent the push button 16 from ejecting completely out of the opening 38, a wall 33 of the push button 16 comprises a flanged end 36 which is closely received by a cavity 39 defined within the body 12 and 25 which has a larger dimension that the opening 38. The flanged end 35 also serves to smoothly guide the push button 16, as it is depressed inwardly into the body 12. The push button assembly further comprises a retaining 30 arrangement in the form of an arm 44 coupled to one pivotable side of the rocker 18. The arm 44 is configured such that when the rocker 18 is pivoted so that the end on which the arm is coupled points down (i.e. the switch is on), a free end of the arm 44 is angled toward a retaining 35 cavity 50 defined in the push button outer wall 33. This is best shown in Figure 4. As the push button 16 is depressed (i.e. to turn the switch off), the rocker 18 25416701 (GHMatters) 20/01/11 - 10 pivots causing the free end of the arm to enter the retaining cavity 50. As the push button 16 is released, the free end of the arm 44 seats in a grove 52 defined in the retaining cavity 50, to prevent the push button 16 5 from projecting out of the body 12. A method for turning the switch on and off will now be described with reference to the progressive schematic illustrations shown in Figures 6a and 6b. 10 Figure 6a shows an operation for turning the switch off. As is evident from the first slide 602, the push button 16 partially extends out of the body 12, indicating that the switch is on. At slide 604, the push button 16 is 15 partially depressed, causing the mallet head 30 to engage the raised side of the rocker 18. As the push button 16 continues to be depressed (slides 606, 608, 610 and 612), the mallet head 30 pushes down on the rocker 18 causing the rocker 18 to pivot to the opposing side and in turn 20 moving the striker 24 to the opposing off position. At slide 614 the push button 16 is released and the retaining arm 44 seats in the groove 52 to prevent the push button 16 from extending out of the body 12. 25 Figure 6b shows an operation for turning the switch on. As is evident from the first slide 620, the push button 16 is largely contained within the body 12, indicating that the switch is off. At slide 622, the push button 16 is partially depressed, causing the mallet head 30 to engage 30 the raised side of the rocker 18 (which in this case is the opposite side to that shown in the corresponding slide of Figure 6a). As the push button 16 continues to be depressed (slides 624 to 630), the mallet head 30 pushes down on the rocker 18 causing the rocker 18 to pivot to 35 the opposing side and in turn moving the striker 24 to the opposing on position. At the same time, due to pivoting of the rocker, the retaining arm 44 is unseated from the 25416701 (GHMatters) 20/01/11 - 11 groove 52 and as the push button is released (see slide 632), escapes from the retaining cavity 50 altogether, allowing the push button to partially extend out of the body 12 to thereby indicate that the switch is on. 5 In an embodiment, the wall 33 of the push button 16 may be coloured to more visibly indicate that the switch is "on". For example, the wall may comprise a red coating as shown in the first slide of Figure 7. In another embodiment, 10 the opening 38 or cavity 39 defined within the body may be colored (see slide 704 of Figure 7) to serve as a guide as to how far the push button 16 needs to be depressed and equally to indicate a change of state. 15 It will be understood by persons skilled in the art, that an opposite on/off configuration to that previously described may be achieved. For example, the poles could be re-wired such that when the push button extends out of the body as shown in slide 702 of Figure 7 the switch is 20 deemed to be off and likewise, when sitting flush with the opening, deemed to be turned on. In an embodiment the switch may be illuminated. This may be achieved in a number of different ways, for example, by 25 way of LED's, small neons, or small lamps. The aforementioned light sources may be incorporated into the body of the existing switch, or adaptor, with provision made in the push button/rocker (e.g. by way of a transparent window in the push button) for the light to 30 shine through. Illumination of the light source may be linked to the switch state, or equally could be controlled independently of the switch state. It will be understood that rather than using a snap-in 35 type fitting as illustrated in the drawings, other fastening arrangements may be used such as clip lock fasteners, press stud fasteners and the like. 25416701 (GHMatters) 20/01/11 - 12 Further, rather than being selectively coupled to one of two different sets of poles, the switch may be coupled to more than two poles for electrically coupling a greater 5 number of electrical circuits. For example, more than one central pole (in the same plane) may be provided with associated poles on either side so as to provide more than one electrical pole for switching. 10 Advantages of embodiments of the pushbutton adaptor configuration include the ability to re-use existing rocker switch varieties (such as 20A, double pole, intermediate, etc.) in order to produce push button functionality. Furthermore, addition of the adaptor 15 mechanism increases the high voltage breakdown which may be particularly advantageous in hazardous areas, by virtue of the extra layer of parts within the push-button adapter assembly (specifically between the touch point and the live parts). 20 It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any 25 other country. In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary 30 implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. 25416701 (GHMatters) 20101/11

Claims (20)

1. A push button adaptor for a rocker-type switch, the adaptor comprising: 5 a body; and a push button assembly located in the body and comprising a push button, such that a first depression of the push button actuates the rocker-type switch to turn the switch on and a second depression of the push button io actuates the rocker-type switch to turn the switch off.

2. A push button adaptor in accordance with claim 1, wherein the push button assembly comprises a pivotable member which, in use, engages a movable contact of the 15 rocker-type switch.

3. A push button adaptor in accordance with claim 2, wherein the pivotable member comprises a cavity arranged to receive a free end of the movable contact, the cavity 20 extending inwardly toward a pivot point of the pivotable member.

4. A push button adaptor in accordance with claim 3, further comprising a coil spring which seats on an end of 25 the movable contact and provides a bias force on the pivotable member.

5. A push button adaptor in accordance with claim 3 or claim 4, wherein an internal wall of the cavity comprises 30 generally rounded or chamfered outer ends.

6. A push button adaptor in accordance with any one of claims 2 to 5, wherein the first depression of the push button causes the pivotable member to pivot to a first 35 position thereby causing the movable contact to move to one side to electrically contact a first set of poles for turning the switch on. 25416701 (GHMatlers) 20/01/11 - 14

7. A push button adaptor in accordance with claim 5, wherein the second depression of the push button causes the pivotable member to pivot to a second position thereby 5 causing the movable contact to move to another side to electrically contact a second set of poles for turning the switch off.

8. A push button adaptor in accordance with any one of 10 claims 2 to 7, wherein the push button assembly further comprises an engaging member coupled to the push button, the engaging member operable to engage a raised side of the pivotable member as the push button is depressed to change the pivot position. 15

9. A push button adaptor in accordance with claim 7, wherein the engaging member is a swinging piston, a head of the swinging piston being operable to swing in the direction of the raised side of the pivotable member for 20 engagement.

10. A push button adaptor in accordance with claim 9, wherein the swinging piston is shaped in the form of a mallet. 25

11. A push button adaptor in accordance with claim 9 or claim 10, wherein the push button assembly further comprises a spring plate arranged to centre the swinging piston after the pivotable member has disengaged from the 30 pivotable member.

12. A push button adaptor in accordance with any one of the preceding claims, further comprising a spring arrangement arranged to impart a constant outward force on 35 the push button.

13. A push button adaptor in accordance with claim 12, 25416701 (GHMatters) 20/01/11 - 15 wherein the spring arrangement comprises at least one coil spring which, when fully unloaded, causes the push button to partially project out of an aperture defined in an upper end of the body. 5

14. A push button adaptor in accordance with claim 12 or claim 13, wherein the push button arrangement further comprises a retaining arrangement arranged to prevent the push button from partially projecting out of the aperture io when in a particular one of the on or off states.

15. A push adaptor as claimed in claim 14, wherein the retaining arrangement comprises an arm extending from the pivotable member at one side thereof toward the push is button, the arm arranged to be located in a retaining cavity defined in a wall of the push button as the push button is depressed to turn the switch off, such that as the push button is released the arm seats in a grove defined in the retaining cavity to prevent the push button 20 from partially projecting out of the aperture.

16. A push adaptor as claimed in claim 15, wherein upon the push button being depressed a second time thereby causing the pivotable member to pivot, the arm unseats 25 from the grove and, as the push button is released, escapes out of the channel to thereby allow the push button to project partially out of the body.

17. A push button switch adaptor as claimed in any one of 30 the preceding claims, further comprising a colour indicator located on a wall of the push button which is visible when the push button partially extends out of the aperture. 35

18. A kit for a push button switch, the kit comprising a push button switch adaptor as claimed in any one of the preceding claims when dependent on claim 2, and a rocker 25416701 (GHMatters) 20/01/11 - 16 type switch comprising a movable contact arranged to be moved by the pivotable member for turning the switch on or off. 5

19. A method of fitting a push button assembly as claimed in any one of the preceding claims, to a rocker-type switch comprising a rocker coupled to a movable contact within the rocker-type switch and arranged to move the movable contact between one of a first and second position io for turning the switch on or off, the method comprising: removing the rocker; and coupling the push button assembly to the rocker-type switch such that the pivotable member receivingly engages the movable contact. 15

20. A push button adaptor substantially as herein described with reference to the accompanying drawings. 2541670_1 (GHMatters) 200111