Rotary switch employing keypad or similar mechanism for position indication

Abstract

A rotary switch with a knob having an axis of rotation and moveable to a plurality of angular positions and an elongated member extending in a longitudinal direction relative to the axis of the knob. A conductive member is positioned near a plurality of angularly displaced traces formed on a Printed Circuit Board. When the knob is rotated, the rotation is translated to longitudinal movement of the conductive member, which contacts at least one trace to close a circuit.

Claims

1. A rotary switch comprising: a plurality of contacts; a knob having an axis of rotation and moveable to a plurality of angular positions; a plurality of elongated members, each having a proximal end and extending in a longitudinal direction generally parallel to the axis of said knob; a plurality of conductive members, each moveable in the longitudinal direction; each of said plurality of elongated members having a distal end adjacent to one of said plurality of conductive members; wherein angular movement of said knob translates to longitudinal displacement of said plurality of conductive members; wherein each of the plurality of conductive members comprises a resilient member which urges a corresponding conductive member away from a corresponding set of contacts; wherein said knob comprises a side wall having a lower end; wherein the proximal end of each of said plurality of elongated members comprises a tapered end, a plurality of which sit against the lower end of the side wall of said knob so that a plurality of elongated members cause a plurality of conductive members to be in contact with the plurality of contacts; wherein the lower end of the side wall of said knob includes a cavity at an angular position, the cavity having a shape corresponding to a shape of the tapered ends of the plurality of elongated members; wherein one of the plurality of elongated members is longitudinally displaced when said knob is rotated to an angular position corresponding to the one of the plurality of elongated members; and wherein the conductive member associated with the longitudinally displaced elongated member is urged out of contact with a corresponding contact by the corresponding resilient member while simultaneously the cooperation of the tapered end of the longitudinally displaced elongated member with the correspondingly shaped cavity in the lower end of the side wall of said knob causes the tapered end of the longitudinally displaced elongated member to seat within the correspondingly shaped cavity in the lower end of the side wall of said knob so as to provide haptic feedback for a user indicative of said knob being in a specific rotational position.

2. The rotary switch according to claim 1 further comprising a base within which said knob is positioned, wherein said knob is rotatable relative to said base.

3. The rotary switch according to claim 1 wherein said plurality of contacts are positioned on a printed circuit board.

4. The rotary switch according to claim 1 wherein said plurality of contacts are angularly offset from each other.

5. The rotary switch according to claim 1 wherein said plurality of contacts form an angular pattern of at least 90 degrees.

6. A rotary switch comprising: a plurality of traces formed in an angular pattern relative to each other on a printed circuit board; a knob having an axis of rotation and moveable to a plurality of angular positions, said knob comprising a side wall having a lower end; a plurality of elongated members, each having a proximal end and extending in a longitudinal direction generally parallel to the axis of said knob; a plurality of conductive members, each moveable in the longitudinal direction relative to the axis of said knob and each comprising a resilient member which urges a corresponding conductive member away from a corresponding set of contacts; each of said plurality of elongated members having a distal end adjacent to one of said plurality of conductive members, and wherein the proximal end of each of said plurality of elongated members comprises a tapered end, a plurality of which sit against the lower end of the side wall of said knob so that a plurality of elongated members cause a plurality of conductive members to be in contact with the plurality of contacts; and wherein angular movement of said knob translates to longitudinal displacement of said plurality of conductive members; wherein the lower end of the side wall of said knob includes a cavity at an angular position, the cavity having a shape corresponding to a shape of the tapered ends of the plurality of elongated members; wherein one of the plurality of elongated members is longitudinally displaced when said knob is rotated to an angular position corresponding to the one of the plurality of elongated members; and wherein the conductive member associated with a longitudinally displaced elongated member is urged out of contact with the corresponding contact by the corresponding resilient member while simultaneously the cooperation of the tapered end of the longitudinally displaced elongated member with a correspondingly shaped cavity in the lower end of the side wall of said knob causes the tapered end of the longitudinally displaced elongated member to seat within the correspondingly shaped cavity in the lower end of the side wall of said knob so as to provide haptic feedback for a user indicative of said knob being in a specific rotational position.

7. The rotary switch according to claim 6 further comprising a base within which said knob is positioned, wherein said knob is rotatable relative to said base.

8. The rotary switch according to claim 6 wherein said plurality of traces form an angular pattern of at least 90 degrees.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a cut away view of one configuration of the rotary switch.

(2) FIG. 2 is a cut away view of the configuration according to FIG. 1 where the conductive member is displaced downward toward a contact or trace.

(3) FIG. 3 is top view of a plurality of contacts according to FIG. 1

(4) FIG. 4 is a perspective view showing the bottom surface of the conductive member.

(5) FIG. 5 is a perspective view showing two elongated members, each having wheels positioned at distal ends according to FIG. 1.

(6) FIG. 6 is a cut away view of one configuration of the rotary switch.

(7) FIG. 7 is an interior view of the configuration according to FIG. 6 where the conductive member is displaced downward toward a contact or trace.

(8) FIG. 8 is a side view of the configuration according to FIG. 7.

(9) FIG. 9 is a perspective view showing potential configurations of buttons or domes that may be used to hold a conductive member according to FIG. 8.

(10) FIG. 10 is a bottom view according to FIG. 9.

(11) FIG. 11 is a perspective view of a plurality of contacts that are angularly offset from each other according to FIG. 8.

(12) FIG. 12 is a bottom view according to FIG. 11.

(13) FIG. 13 is a top view of a set of contacts or traces over which a conductive member may be positioned according to FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

(14) Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views.

(15) FIG. 1 comprises a cut away view of a rotary switch 100. Rotary switch 100 includes a knob 102 that comprises an upper portion 104 that may be grasped and rotated. The knob 102 also includes two channels 106, 106 within which two elongated members 108, 108 are positioned. The knob 102 also comprises a side wall 110, which is better illustrated in FIG. 5, which is formed as a cylinder. The two channels 106, 106 are formed on an inside surface of the side wall 110.

(16) Also illustrated in FIG. 1 is base 112, which comprises a circular lower portion 114 and a cylindrical upper portion 116. As can be seen with reference to FIG. 1, the side wall 110 is provided with an outer circumference that allows it to fit inside of cylindrical upper portion 116 of base 112. In practice the inner diameter of cylindrical upper portion 116 will be selected to be just a little larger than the outer circumference of side wall 110. This will allow side wall 110 to rotate freely within cylindrical upper portion 116. It can also be seen that an upper end 118 of cylindrical upper portion 116 is provided to fit within an angular groove 120 of knob 102 (FIG. 5). It is contemplated that, while knob 102 may freely rotate relative to base 112, that knob 102 may be mechanically held to base 112 such that axial movement is prevented. The mechanism for holding the parts together can comprise any method known in the art, including for example, an annular undercut and a protrusion engaging with the undercut (FIG. 5).

(17) Also shown in FIG. 1 is a Printed Circuit Board (PCB) 122 that is coupled to base 112. The PCB 122 will be discussed further in connection with FIG. 3. It is contemplated that PCB 122 can be coupled to or affixed to base 112 by any commonly known method including, for example, friction fit, screws or fasteners, a mechanical fit where the PCB 122 engages with protrusions or channels in the base, or any other appropriate method.

(18) A flexible conductive member 124 is placed on top of the PCB 122. The conductive member 124 can be better seen with reference to FIG. 4. The conductive member 124 is provided with a relatively flat upper surface 126.

(19) Finally, two wheels 128, 128 are positioned, one at the distal end of each of the two elongated members 108, 108. The two wheels 128, 128 are positioned so that they engage with upper surface 126 of conductive member 124.

(20) With reference to FIG. 2, the conductive member 124 is illustrated deflecting in a longitudinal direction relative to an axis of rotation (illustrated by arrows) of knob 102. As the wheel 128 engages with the upper surface 126 of conductive member 124, this causes the conductive member 124 to flex or be pushed downward toward PCB 122. This downward or longitudinal flexing causes a bottom surface 130 of conductive member 124 to contact the surface of the PCB 122. From an operational standpoint, it can be seen that, as the knob 102 is angularly displaced (rotated) the wheels 128, 128 will also rotate relative to the conductive member 124. This will result in conductive member 124 being pushed downward at various angular locations depending upon the angular position of knob 102.

(21) Turning now to FIG. 3, PCB 122 is illustrated as a flat circular shape. An upper surface 132 is provided having a plurality of contacts or traces 134 positioned thereon. In FIG. 3 a total of 18 different contacts or traces 134 are illustrated, however, it will be understood that any number may be used depending upon the application. Likewise, while the concept of the contacts or traces 134 being angularly offset from each to form 360 degrees of rotation for switch 100, it is contemplated that contacts or traces 134 could be formed at an angle less than 360 degrees, including, for example, 90 degrees or 180 degrees. Again, the configuration can vary depending upon the application.

(22) Also illustrated in FIG. 3 is contact or trace 136. Contact or trace 136 is illustrated in the shape of a ring and radially offset from contacts or traces 134. In FIG. 3, contact or trace 136 is provided near the outside edge 138 of PCB 122 such that contacts or traces 134 are all radially maintained within contact or trace 136.

(23) FIG. 4 illustrates the underside (the side facing PCB 122) of conductive member 124. As can be seen, the conductive member 124 is formed as a ring. The upper surface 140 is generally flat in construction. The bottom surface 130, however, is provided with an annular shoulder 142 that provides a raised portion around a perimeter of the bottom surface 130. Additionally, an inner shoulder 144 is provided such that, a recess 146 is defined between the annular shoulder 142 and the inner shoulder 144. The conductive member is placed with the recess 146 overlaying the plurality of contacts or traces 134.

(24) The conductive member 124 is provided as a flexible resilient member that can deform and return to its original shape. In one configuration, conductive member 124 comprises conductive silicone (carbon molded into silicone for conductivity). Conductive member 124 may also be provided with conductive regions corresponding to the bottom surface 130. In one instance, annular shoulder 142 and recess 146 define the conductive regions.

(25) When the conductive member 124 is overlaid on PCB 122, the annular shoulder 142 will directly rest on contact or trace 136. The conductive material forming recess 146 will only come in contact with contacts or traces 134 if the material is displaced due to wheel 128, 128. In this way, different circuits are closed depending on the angular position of the knob 102.

(26) Turning now to FIG. 6, an alternative configuration is shown as rotary switch 200. Rotary switch 200 includes a knob 202 that comprises an upper portion 204 that may be grasped and rotated. The knob 202 also comprises a side wall 206, which is better illustrated in FIG. 8, which is formed as a cylinder. A notch or cavity 208 is form on a lower end side wall 206.

(27) Also illustrated in FIGS. 6 and 7 is base 210, which comprises a circular lower portion 212 and a cylindrical upper portion 214. As can be seen with reference to FIG. 6, the side wall 206 is provided with an outer circumference that allows it to fit inside of cylindrical upper portion 214 of base 210. In practice the inner diameter of cylindrical upper portion 214 will be selected to be just a little larger than the outer circumference of side wall 206. This will allow side wall 206 to rotate freely within cylindrical upper portion 214. It can also be seen that an upper end 216 of cylindrical upper portion 214 is provided to fit within a groove 218 of knob 202 (FIG. 6). It is contemplated that, while knob 202 may freely rotate relative to base 210, that knob 202 may be mechanically held to base 210 such that axial movement is prevented. The mechanism for holding the parts together can comprise any method known in the art, including for example, an annular undercut and a protrusion engaging with the undercut (FIG. 6).

(28) Referring now to FIG. 8, elongated members 220 are provided having a first end 222 and a second end 224. As can be seen with reference to FIG. 8, the first end 222 is provided with a tapered end that sits against an end 226 of side wall 206. As is better seen in FIG. 6, elongated members 220 are positioned and held in place by base 210 while at the same time are allowed to move longitudinally.

(29) Second end 224 abuts dome or button 228, which may comprise a relatively flat upper surface 230 (FIG. 9). With reference to FIGS. 9 through 13, it can be seen that dome or button 228 also includes a deflectable portion 232 such that, when the second end 224 presses downward on upper surface 230, the deflectable portion 232 allows the dome or button 228 to be pressed downward. As can be seen a top view (FIG. 9) and a bottom view (FIG. 10) of the dome or button 228 is illustrated. It is contemplated that a conductive member 234 may be positioned on an underside 236 of flat upper surface 230. When the dome or button 228 is depressed fully, the conductive member 234 comes in contact with a set of contacts or traces 238 (FIG. 13), which functions to close the set of contacts or traces 238.

(30) The dome or button 228 may be provided individually, as shown in FIGS. 9 and 10, or may be provided as a unitary structure as illustrated in FIGS. 11 and 12.

(31) As shown in FIGS. 11 and 12, a plurality of domes or button may be formed into a ring structure and termed a keypad 242 that can be placed over the various contacts or traces 238 that may be positioned on a PCB 240 affixed or attached to base 210.

(32) In operation, the knob 202, when rotated, actuates the elongated members 220 (pins) downward when they are not aligned with the notch or cavity 208. The elongated members 220 (pins) are guided by the base 210 (housing) and actuate individual dome or button 228 on the keypad 242.

(33) When an individual dome or button 228 is depressed, this functions to close a set of contacts or traces 238, which in turn closes a circuit on the PCB 240 when the conductive member 234 touches its associated contact or trace 238 on PCB 240.

(34) The conductive member 234 may comprise a conductive region formed as a structure molded into the underside 236 of flat upper surface 230, or it could comprise a conductive membrane.

(35) In one configuration, keypad 242, may comprise a silicone with a carbon structure molded in as the conductive regions. Alternatively, it could comprise a multi-piece assembly. As a further alternative, it is contemplated that elongated members 220 (pins) could be provided with a conductive bottom.

(36) The domes or buttons 228 provide a spring-force in this design by means of deflectable portion 232.

(37) As an alternative, to the conductive regions, inserts such as molded metal pieces could be used to close the contacts or traces 238.

(38) It is still further contemplated that the rotary switches 100, 200 may be provided with haptics to indicated position to the user. Some methods that could effectively be used include: flexible plastic against grooved surfaces, or springs and plungers (ball bearings) in tubes, with the ball bearing riding on a grooved surface to compress the spring (e.g., the grooved surface could be associated with the base or the knob).

(39) Referring to FIGS. 6 and 8, a notch or cavity 208 in the knob 202 in this assembly allows the elongated members 220 (pin) to move up. In one configuration, there are symmetrical pins and grooves positioned 180 degrees about the axis of the knob 202 for optimal haptics. However, it will be understood that symmetry is an optional feature.

(40) Although the invention has been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many other modifications and variations will be ascertainable to those of skill in the art.