<p>S WITCH</p>
<p>The present invention relates to a switch.</p>
<p>Switches are used in electric circuits to allow a user to selectively open and close an electric circuit. One type of switch is a continuous strip switch which allows a user to activate the switch by manipulating any part of the length of the switch.</p>
<p>A known continuous strip comprises a rubber tubular body, having two sections of copper wire cored conductive rubber and an insulating Section of non-conductive rubber. The cross-sectional shape of the first section of copper wire cored conductive rubber is part circular and the cross-sectional shape of the second section of copper wire cored conductive rubber is generally triangular. The first and second sections are configured so that the point of the triangle of the second section extends towards the concave face of the part circular first section. In its inactive state the first and second sections of copper wire cored conducting rubber are held apart. However, the tubular body can be compressed so as to bring the concave face of the first section into contact with the point of the triangular shaped second section of copper wire cored conductive * ** rubber, so as to close the switch. There are difficulties in manufacturing such * * * *... 20 continuous strip switches. Further, such switches can easily be activated inadvertently. *S..</p>
<p>**.... Accordingly, the present invention provides an improved switch, and in particular an improved continuous strip switch. ** *</p>
<p>In accordance with a first aspect of the invention there is provided a switch comprising: * a substantially tubular body resiliently defonnable between a non-deformed state and a deformed state; and a first non-apical electrical contact strip secured to a first internal wall of the substantially tubular body and a second non-apical electrical contact strip secured to a second internal wall of the substantially tubular body so that the first non-apical electrical contact strip and second non-apical electrical contact strip are in a spaced apart relationship in the non-deformed state and are in contact in the deformed state.</p>
<p>I</p>
<p>It has been found that securing first and second non-apical electrical contact strips to internal walls of a substantially tubular body provides a reliable switch which is not easily accidentally activated. The use of non-apical electrical contact strips allows an appropriate contact strip separation distance to be achieved which reduces inadvertent activation. Further, the electrical contact strips are protected from the environment by the substantially tubular body.</p>
<p>Preferably, at least one of the first non-apical electrical contact strip and the second non-apical electrical contract strip is planar. Optionally, both the first non-apical electrical contact strip and the second non-apical electrical contract strip can be planar.</p>
<p>The first electrical contact strip and the second electrical contact strip can each be fastened to the substantially tubular body along only a portion of their lengths.</p>
<p>Preferably, the first electrical contact strip and second electrical contact strip are fastened to the substantially tubular body along at least 50% of their length, more preferably at least 75% of their length, especially preferably at least 90% of their length. Preferably, the first electrical contact strip and second electrical contact strip are each welded to the substantially tubular body along substantially their entire length. * *. * * . **I.</p>
<p>Preferably, in the non-deformed state the first non-apical electrical contact strip and the second non-apical electrical contact strip are spaced apart by 5mm or more. The closer * S. * together the first and second non-apical electrical contact strips are the more likely the switch is to be activated accidentally. Preferably, the distance between the first non-apical electrical contact strip and the second non-apical electrical contact strip is not * S * * 25 more than 7mm. The further apart the first and second non-apical electrical contact S...</p>
<p>strips are the greater the distance it is required to activate the switch. However, as would be understood, the preferred maximum distance between the first and second non-apical electrical contact strips can vary depending on the application in which the switch is to be used.</p>
<p>Preferably, the first non-apical electrical contact strip and the second non-apical electrical contact strip are substantially diametrically disposed in the substantially tubular body.</p>
<p>Preferably, the substantially tubular body comprises a first body part secured to a second body part. This increases the ease of manufacture and assembly of the substantially tubular body. Also, forming the substantially tubular body from first and second body parts allows for a modular design. Accordingly, a number of different shaped and sized first and second body parts can be provided which can be selected and combined by the user to suit the application in which the switch is to be used.</p>
<p>The first body part can be made from a material having different mechanical properties to the material of the second body part. It is not necessary for both the first and second body parts to be made from a resiliently deformable material. Only at least one the 1 5 first and second body parts need be made from a resiliently deformable material. One of the first and second parts can be made from a stiff material. This can aid assembly of the substantially tubular body. For instance, one of the first and second parts can be made from a resiliently deformable material such as any of vinyl films, polyurethane, * ** polypropylene coated fabric, polyethylene and thermoplastic rubber. Preferably, one of the first and second parts is made from a polyvinyl chloride (PVC) material, for example a PVC Nitrile blend, particularly a PVC Nitrile blend suitable for dynamic gasket applications, such as DNC8O. The other of the first and second parts can also be made from a non-deformable material such as a stainless steel, non-flexible PVC material or other suitable polymeric materials. Preferably, the other of the first and * 25 second parts is made from a less deformable PVC material. Preferably, the first body *I.. * *</p>
<p>* part is made from a deformable body material and the second body part is made from a material that is less deformable than the material of the first body part. Preferably, the second body part is made from a non-deformable material.</p>
<p>Preferably, the first and second body parts are welded to each other. This provides for a strong bond between the first and second body parts. It also provides for a flexible bond between the first and second body parts and therefore improves the reliability and performance of the switch.</p>
<p>Both the first and second non-apical electrical contact strips can be secured to either the first or second body part. Preferably, the first non-apical electrical contact strip is secured to the first body part and the second non-apical electrical contact strip is secured to the second body part. This can increase manufacture and assembly of the resiliently deformable body. The first and second non-apical electrical contact strips can be secured to their respective body parts prior to the first and second body parts being fastened together.</p>
<p>The substantially tubular body can comprise a first arcuate wall opposite to and spaced apart from a second arcuate wall by a base. Such a shape has been found to be particularly optimal. The arcuate walls facilitate the deforming of the substantially 1 5 tubular body when it is placed under compressive forces. The first arcuate wall can terminate in a first planar wall and the second arcuate wall can terminate in a second planar wall. The first planar wall and second planar wall can be in a substantially parallel spaced apart relationship. Optionally, the first planar wall and second planar : wall can be substantially coplanar. 20 *S* S *</p>
<p>Preferably, the first body part comprises the first arcuate wall opposite to and spaced apart from the second arcuate wall by the base, wherein the first arcuate wall terminates in the first planar wall and the second arcuate wall terminates in the second :. planar wall. The first planar wall and the second planar wall can be used for securing * 25 the second body part to the first body part. Preferably, the second body part comprises *S.. * S</p>
<p>a first planar abutment wall for abutment with the first planar.wall and a second abutment wall for abutment with the second planar wall.</p>
<p>Preferably, the second body part taken perpendicularly to its length is substantially anvil-shaped. Such a shape provides features which enable the second body part to be secured to correspondingly shaped features on a device to which the switch is to be fastened.</p>
<p>The shape and dimensions of the first and second body parts can be such that when the substantially tubular body is assembled the second body part extends into the first body part, so that the second non-apical electrical contact strip is located part way along the length of the first and second arcuate walls. Preferably, the ratio of a) the perpendicular distance between the first non-apical electrical contact strip and the second non-apical electrical contact strip, to b) the distance between the height of the arcuate walls taken perpendicularly to the first non-apical electrical contact strip, is not more than 0.5, more preferably not more than 0.4, especially preferably not more than 0.3.</p>
<p>Preferably, the substantially tubular body comprises a first outwardly substantially radially extending leg, and a second outwardly substantially radially extending leg.</p>
<p>Preferably, the first outwardly substantially radially extending leg and the second outwardly substantially radially extending leg extend along at least 90% of the length of the substantially tubular body, more preferably along the substantially the entire length of the substantially tubular body. Preferably, the first outwardly substantially radially extending leg and the second outwardly substantially radially extending leg diverge outwardly away from the substantially tubular body. When the resiliently * ** deformable substantially tubular body comprises a first body part and a second body *:, 20 parts, preferably the first outwardly substantially radially extending leg and the second outwardly substantially radially extending leg are provided on the first body part. * *. * * *</p>
<p>Preferably, the first non-apical electrical contact strip and the second non-apical :. * electrical contact strip are made from a metallic material. More preferably the first * 25 non-apical electrical contact strip and the second non-apical electrical contact strip are **.. *</p>
<p>made from copper. Electrical contact strips made from metallic materials, and in particular made from copper, provide better electrical conduction compared to non-metallic electrically conductive materials. Further, there is much less voltage depletion using metallic contact strips in contrast to other non-metallic electrically conductive materials. Accordingly, the switch of the present invention can be manufactured to much greater lengths compared to switches with non-metallic electrically conductive contact strips.</p>
<p>The first non-apical electrical contact strip and the second non-apical electrical contact strip can be secured to the internal walls of the substantially tubular body by mechanical fastenings. The first non-apical electrical contact strip and the second non-apical electrical contact, strip can be secured to the internal walls of the substantially tubular body by an adhesive.</p>
<p>Preferably, the first non-apical electrical contact strip and the second non-apical electrical contact strip are welded to the substantially tubular body. Preferably, each of the first non-apical electrical contact strip and the second non-apical electrical contact strip comprises a layer of electrically conductive material laminated to a welding material layer, wherein the welding material layer is welded to the substantially tubular body. Preferably, the layer of electrically conductive material is a metallic material.</p>
<p>Preferably, the metallic material is copper.</p>
<p>There are many suitable materials which can be used as the welding material.</p>
<p>Preferably, such materials have shrinkage properties similar to that of the metallic material. In many circumstances it can be preferred that the stiffness of' the welding material is less than that of the metallic material. In some circumstances it can be * ** preferred that stiffness of the welding material is greater than that of the metallic layer.</p>
<p>Preferably, the welding material has a UL rating of approximately IOSC. Preferably, the welding material is a polyester material. More preferably, the welding material is polyethylene terephthalate (PET).</p>
<p>S ***</p>
<p>S</p>
<p>Welding the first non-apical electrical contact strip and the second non-apical electrical contact strip to the substantially tubular body by the welding material layer provides a firm bond between the layer of electrically conductive material and the substantially tubular body. This welded bond is advantageous over other forms of fastening, such as using mechanical grippers, because it provides for a much more secure fixing.</p>
<p>Accordingly, the switch feels much more solid and responsive to the user. It is also advantageous because the bond between the layer of electrically conductive material and the substantially tubular body is flexible. This provides for the deformation of the substantially tubular body without breaking the bond between the layer of electrically conductive material and the substantially tubular body, and therefore increases the reliability and durability of the switch.</p>
<p>Preferably, the thickness of the welding material layer is at least 2 microns, more preferably at least 3 microns, for example at least 4 microns. Preferably, the thickness of the welding material layer is not more than 600 microns, more preferably not more than 500 microns. The thickness of the welding material layer affects the quality of the bond between the layer of electrically conductive material and the substantially tubular body. The preferred thickness of the welding material layer can depend on the thickness of the layer of electrically conductive material to which it is laminated.</p>
<p>Preferably, the ratio of the thickness of the welding material layer to the thickness of the layer of electrically conductive material is not more than 3, more preferably not more than 2, especially preferably not more than 1. As will be understood, the thickness of the welding material depends on the application in which the switch is to be used.</p>
<p>The substantially tubular body can be made from any suitable material that can be deformed under an external force and return to its original shape on removal of the : ** external force. Suitable materials include vinyl films, polyurethane, polypropylene ** 20 coated fabric, polyethylene and thermoplastic rubber. Preferably, the resiliently deformable substantially tubular body is made from pol'inyl chloride (PVC). * I. * S S * S.</p>
<p>Preferably, in use the substantially tubular body is deformable manually by pressing in * a direction substantially perpendicular to the first non-apical electrical contact strip and * 25 second non-apical electrical contact strip. *555 S * 555.</p>
<p>Preferably, the second body part has an exterior planar pressing surface in substantially parallel spaced apart relationship to the first electrical contact strip and the second electrical contact strip, wherein in use the exterior pressing surface is pressed to deform the substantially tubular body and bring the first non-apical electrical contact strip into contact with the second non-apical electrical contact strip. Providing such an exterior pressing surface is advantageous as it can provide a visual indication to the user as to which direction the substantially tubular body should be pressed to bring the first nonapical electrical contact strip into contact with the second non-apical electrical contact strip.</p>
<p>In accordance with a second aspect of the invention there is provided a door assembly comprising: a substantially planar door movable between an open position and a closed position through intermediate positions, and a switch as defined above mounted on the door such that through contact with a foreign body at an intermediate position the switch is activated to stop movement of the door.</p>
<p>The switch can comprise a first outwardly substantially radially extending leg, and a second outwardly substantially radially extending leg. Such a switch can be mounted on the basal edge of the door so that the first outwardly radially extending leg and the second outwardly radially extending leg are downwardly dependent.</p>
<p>Typically the door will be a door which slides substantially in the plane of the door between the open position and the closed position.</p>
<p>: ** Typically, the door will be a garage door.</p>
<p>S</p>
<p>In accordance with a third aspect of the invention there is provided a method of manufacturing a switch comprising: welding to a resiliently deforrnable body a first layer of welding material which is laminated to a first layer of electrically conductive * material; and welding to the resiliently deforrnable body a second layer of welding * 25 material which is laminated to a second layer of electrically conductive material so that * S the first and second layers of electrically conductive materials can be brought together by deforming the resiliently deformable body.</p>
<p>The method of the present invention provides a firm bond between the layers of electrically conductive material and the resiliently deformable body. This welded bond is advantageous over other forms of fastening, such as using mechanical grippers, because it provides for a much more secure fixing and provides a much more solid and responsive feel to the user. It is also advantageous because the joint between the layers of electrically conductive material and the resiliently deformable body is flexible. This allows the deformation of the resiliently deformable body without breaking the bond between the layers of electrically conductive material and resiliently deformable body, and therefore increases the reliability and durability of the switch.</p>
<p>Preferably, the step of welding comprises injecting heat between the layer of welding material and the resiliently deformable body using a heat injecting device. Preferably, the step of welding further comprises pressuring the layer of welding material and the resiliently deformable body together using a compressing device to form a molecular bond between the layer of welding material and the resiliently deformable body.</p>
<p>Preferably, the welding material is a polyester material. More preferably, the welding material is polyethylene terephthalate (PET). Preferably, the electrically conductive material is a metallic material. Preferably, the metallic material is copper.</p>
<p>The temperature to which the layer of welding material and resiliently deformable body are heated depends on a number of factors such as the type of welding material, the thickness of the layer of welding material and resiliently deformable body and the material of the resiliently deformable body. When the layer of welding material is a layer of polyester material, preferably, the temperature to which the polyester layer and * ** ** resiliently deformable body are heated is no less than 260 C. Preferably, the * *.</p>
<p>temperature to which the polyester layer and resiliently deformable body are heated is no more than 732 C. S. S</p>
<p>:.* 25 The step of injecting heat between the layer of welding material and the resiliently deformable body can comprise blowing heated air between them. Optionally, the step of injecting heat between the layer of welding material and the resiliently deformable body can comprise passing the layer of welding material and resiliently deformable body over a heated object.</p>
<p>The step of pressuring the layer of welding material and the resiliently deformable body together can comprise passing the layer of welding material and the resiliently deformable body between first and second rollers which force the layer of welding material and the resiliently deformable body together. Preferably, the step of pressuring the layer of welding material and the resiliently deformable body together comprises driving the first and second rollers so as to advance the layer of welding material and the resiliently deformable body between the first and second rollers.</p>
<p>Accordingly, the rollers can control the speed by which layer of welding material and the resiliently deformable body pass through the apparatus which performs the method of the invention. In particular, it enables the rollers to control the amount of time it takes for the layer of welding material and resiliently deformable body to pass past the heating device.</p>
<p>An embodiment of the invention will now be described by way of example only with 1 5 reference to the following figures in which: Figure 1 shows a perspective view of a switch in accordance with the a first embodiment of the present invention; . 20 Figure 2 shows an exploded perspective view of the switch shown in Figure 1; * * * Figure 3 shows a side view of an apparatus for welding a contact to a body part of the * switch shown in Figure 1; *I* 25 Figure 4 shows a side view of a switch according to a second embodiment of the * * invention attached to a garage door; Figure 5 is a schematic circuit diagram of a control system in which the switch shown in Figure 4 is used; and Figure 6 shows an end view of a first contact strip of the switch shown in Figure 1.</p>
<p>Referring to the drawings, figure 1 shows a schematic perspective view of an embodiment of the switch 2 of the invention. The switch 2 generally comprises a substantially tubular body 4 and a first contact strip 6 and a second contact strip 8. The first 6 and second 8 contact strips are substantially planar in configuration.</p>
<p>As shown in figures 1 and 2, the substantially tubular body 4 comprises a first body part 10 and a second body part 12. The first body part 10 comprises an elongate, solid member, on a first elongate face 62 of which is mounted the first contact strip 6. The elongate member has as T-shaped projection 14 extending along a second elongate face 64 opposite to the first elongate face 62. Accordingly, the first body part 10 is substantially anvil-shaped.</p>
<p>The second body part 12 has an open cross-sectional shape. The second body part 12 has a planar base 50 extending between the first end of a first arcuate wall 52 and the 1 5 first end of a second arcuate wall 54 that is opposite the first arcuate wall 52.</p>
<p>Extending from each of the second ends of the first arcuate wall 52 and the second arcuate wall 54 is a first upwardly dependent planar wall 56 and a second upwardly dependent planar wall 58. The planar walls 56, 58 extend substantially parallel to each other. The second contact strip 8 is mounted on the base 50. The first body part 10 *::* 20 can fit snugly between the first 56 and second 58 planar walls. The second body part 1 2 also has first 1 6 and second 1 8 legs extending from its base 50. The legs 16, 18 * diverge outwardly from the base 50 of the second body part 12. The outer wall 60 of the substantially tubular body 4 between the legs 16, 18 is corrugated.</p>
<p>S</p>
<p>* 25 The first 10 and second 12 body parts are resiliently deformable and are made from a * * ., PVC/Nitrile blend which complies to the industry standard British Plastics Federation (BPF) 345/2.</p>
<p>With reference to Figure 6, the first contact strip 6 comprises a strip of copper 20 with a polyester backing 22. The polyester backing 22 is laminated on the copper strip 20.</p>
<p>Copper with a polyester backing suitable for use as a contact in a switch according to the present invention is available from GTS Flexible Materials sold under the product name GTS Series: 5500. The second contact strip 8 is essentially identical in shape and form to the first contact strip 6.</p>
<p>To assemble the switch 2, the first contact strip 6 is welded to the base 50 of the first body part 10 and the second contact strip 8 is welded to the first elongate face 62 of the second body part 12. The process for welding the contact strips 6, 8 to their respective body parts 10, 12 is described in detail below with reference to Figure 3. Once the contact strips 6, 8 have been welded to their respective body parts 10, 12, the planar waIls 56, 58 of the second body part 12 are welded to side faces 66, 68 respectively of the first body part 10. Once assembled the first and second contact strips 6, 8 are held apart by the body 4. The distance between the first and second contacts 6, 8 is approximately 5mm.</p>
<p>With reference to Figure 3, the process of welding the first contact strip 6 to the first body part 1 0 is described. The process comprises injecting heat between the polyester layer 22 on the contact strip 6 and the first body part 10 by passing them over an electrically heated high temperature wedge 42. This heats the polyester layer 22 and : *. the first body part 10 so as to prepare them for molecular bonding. In the particular S...</p>
<p>example descnhed, the polyester layer 22 and first body part 10 are heated to 600C. S...</p>
<p>****** The first body part 10 and the first contact strip 6 are then driven past the hot wedge 42 by first and second rollers 24, 26. The rollers 24, 26 which control the amount of time :. * that the polyester layer 22 and first body part 10 are in contact with the hot wedge 42.</p>
<p>Further, the rollers 24, 26 apply pressure to the first body part 10 and the first contact strip 6 so as to compress the heated polyester layer 22 and the first body part 10 together during the welding process so as to complete the molecular bond between them. The process for welding the second contact strip 8 to the second body part 12 is identical to that described above in relation to the first contact strip 6.</p>
<p>An example of the use of a switch according to the present invention is described in relation to Figures 4 and 5. The switch 102 of Figure 4 is substantially the same as the switch 2 described above in relation to figures 2 and 3. However, the switch 102 shown in Figure 4 differs from the switch 2 of Figures 1 and 2 in that the first substantially planar wall 1 56 and second substantially planar wall 1 58 extend from the ends of the first and second arcuate walls 152, 154 of the second body part 112 substantially parallel to the base 1 50. The first substantially planar wall 156 and second substantially planar walls 158 are substantially coplanar. Furthermore, the first body part 110 comprises a first planar wing 170 and a second planar wing 172 extending perpendicularly from the first side wall 166 and second side wall 168 of the first body part 110. The first planar wing 170 and second planar wing 1 72 abut the first substantially planar wall 1 56 and second substantially planar walls 1 58 respectively.</p>
<p>The switch 102 is attached to a garage door 28 and is used to prevent the garage door 28 colliding with an object or person during closure. The switch 102 is connected to the garage door 28 by way of the T-shaped projection of the first body part 110 and corresponding features on the bottom edge of the garage door 28.</p>
<p>If the garage door 28 traps an object while it is being Lowered, the legs 16, 18 will : * contact the object and flex outwardly to create a seal between the body 4 and the object. If the garage door 28 is loweredfurther, the body 4 compresses, thereby bringing the second contact strip 8 towards the first contact strip 6. If the garage door 28 is lowered sufficiently further, the first contact strip 6 and the second contact strip 8 touch each other thereby activating the switch 102. * S S</p>
<p>As shown in figure 5, the switch 102 is used in a control system 44 comprising a door S...</p>
<p>control unit 30, a motor 32 and a door controller 34. The door control system 44 is powered by power supply line 36. In use, an operator can open or close the garage door 28 by pushing the open 38 or close 40 buttons on the door controller 34. This sends a signal to door control unit 30 which interprets the signal and sends a control signal to the motor 32. The motor 32 then drives the garage door 28 so as to open or close it depending on the signal received from the control unit 30. The control unit 30 detects if the switch 102 is activated by the first contact strip 6 and second contact strips 8 contacting each other, and if so sends a signal to the motor 32 so as to stop the garage door 28 from being closed. * S. * * . **.. *..* * S *.*. * *S * S * * *. *..</p>
<p>S *. * S * S * S 5..</p>
<p>S S *.S.</p>