Patent Application
20080130866
The invention relates generally to rotary switch assemblies, and more specifically to rotary switch assemblies having low profiles.
A conventional rotary switch is generally constructed as a device that has a rotating shaft connected to one terminal capable of making or breaking a connection to one or more other terminals. During operation, a user manipulates the switch to manually select a circuit.
Rotary switches are often mounted upon panels and other supporting structures in order that a user may control an electrical device. It is common for a portion of the switch to be on one side of the panel (the user side) and another portion of the switch to be on the other side of the panel (the inside). In many instances, the only portion of a switch that is on the user's side of the panel is a section of the shaft and a knob or other actuating means. Generally, the bulk of the switch is on the inside of the panel. For many years this type of configuration was sufficient, but over time the size of electrical devices became increasingly smaller and there became a need to reduce the size of the switch—especially that portion on the inside of the panel and the overall height of the switch.
In order to meet the needs of smaller devices having less room and of a lower profile, the size of the components of the switches also became smaller. Yet, because these switches are comprised in part of mechanical components, there remained a practical limit as to how small they could become while still remaining useful. There became a need for different designs rather than just a reduction in the size of the components. One such attempt at providing a solution is found in U.S. Pat. No. 7,109,430 B2 issued to Horton et al. While the switch described by Horton may have resulted in a lower overall profile of the combined components, this switch still does not address at least several problems. For instance, the rotary switch 100 is constructed such that the axis of rotation of the rotary shaft 130 can only be installed perpendicularly to the printed wiring board 150 (PWB). Further, the rotary shaft 130 occupies the centre of the rotary switch 100, thereby blocking the placement of a centre push style switch in that location. Also, the rotary switch 100 assembly is complicated in design, and requires the performance of costly and error prone manufacturing techniques. Moreover, the rotary switch 100 requires the construction and installation of an electrical contact 140 that has electrical contacts which sweep across the PWB 150 selectively making and breaking electrical connections. These connections are prone to increased rates of failure since they are subject to wear and contamination by dirt, etc.
Accordingly, the industry sought to improve upon the rotary switch disclosed in Horton. One such improvement to the switch disclosed in Horton has been to use a rotary switch having an annular shaped dial which may be rotated about a centre knob. The dial includes a plastic ring having a precision inset moulding used to selectively make and break electrical connections when the dial is rotated. A small and precision metal stamping activation spring is needed for connecting purposes. Although providing a lower profile than the Horton switch, these types of improved rotary switches are complicated and require special control injection manufacturing techniques to manufacture, and thus are costly to manufacture. Also, they are designed to be mounted only in one orientation, i.e. parallel to the PWB such that the axis of rotation of the dial is perpendicular to the PWB.
Accordingly, there exists a need for an improved rotary switch which has one or more of the following characteristics: a low profile, inexpensive to manufacture, reliable, less prone to failure, less complicated, does not require precision manufacturing techniques and components, which permits the use of a centre mounted switch assembly, and that is more versatile in the orientations in which it can be mounted relative to a PWB.
It is an object of the invention to provide a rotary switch assembly that ameliorates at least some of the disadvantages and limitations of the above prior art.
One embodiment of a rotary switch assembly formed in accordance with the present invention is disclosed. The rotary switch assembly may include a dial assembly having a main body disposed about a centre aperture. The main body may be rotatable about a central axis in both a clockwise direction and a counter clockwise direction. The dial assembly may include at least one projecting member extending outward from the main body. The rotary switch assembly may also include a switch having an actuator moveable in a first direction to a first position for activating a first circuit. The switch may be moveable in a second direction to a second position for activating a second circuit. The actuator may be positioned relative to the dial assembly such that when the dial assembly is rotated clockwise, the projecting member interacts with the actuator to result in the actuator moving in the first direction to the first position, and when the dial assembly is rotated counter clockwise, the projecting member interacts with the actuator to result in the actuator moving in the second direction to the second position.
The rotary switch assembly may include a push activated switch assembly disposed in the centre aperture about which the dial assembly is adapted to be rotated, the push activated switch assembly adapted to selectively activate an electrical circuit when activated. The rotary switch assembly may have a height, with the push activated switch assembly disposed in the centre aperture, less than about 10 mm. The height of the rotary switch assembly may be less than about 10 mm. The height of the rotary switch assembly may be less than about 5 mm. The outer diameter or width of the dial assembly may be less than about 50 mm, or even less, such as less than about 40, 30, or 25 mm.
The rotary switch assembly may be mountable to a printed wiring board such that the central axis is oriented substantially parallel to the printed wiring board. The projecting member may be oriented substantially perpendicular to the central axis and may extend radially outward from the main body of the dial assembly. The projecting member may be oriented to extend outward from the main body in a direction substantially parallel to the central axis. The projecting member may be oriented to extend outward from the main body in a direction substantially parallel to the central axis. The projecting member may include an outer facing cam surface adapted to engage the actuator as the dial assembly is rotated in the clockwise direction and an inner facing cam surface adapted to engage the actuator as the dial assembly is rotated in the counter clockwise direction.
The dial assembly may include at least a first recess and a second recess, wherein the rotary switch assembly includes a biasing assembly for biasing a retaining member into either the first recess or the second recess to hold the dial assembly in a selected position. When the dial assembly is rotated, the retaining member may be adapted to be driven from the first recess to the second recess or from the second recess to the first recess. The actuator may be oriented substantially parallel to the central axis. The actuator may be oriented substantially perpendicular to the central axis. The actuator may be biased to normally reside in a central default position. The dial assembly may be rotated in the clockwise direction such that the projecting member drives the actuator from the central default position to the first position. The dial assembly may be rotated in the counter clockwise direction such that the projecting member drives the actuator from the central default position to the second position. The switch may be a two-way direction detector switch.
An alternative embodiment of a rotary switch assembly formed in accordance with the present invention is disclosed. The rotary switch assembly may include a dial assembly having a main body disposed about a centre aperture. The main body may be rotatable about a central axis in both a clockwise direction and a counter clockwise direction. The dial assembly may include at least one projecting member extending outward from the main body. The rotary switch assembly may include a two way direction detector switch having an actuator moveable in a first direction to a first position for activating a first circuit. The actuator may also be moveable in a second direction to a second position for activating a second circuit. The actuator may be positioned relative to the dial assembly such that when the dial assembly is rotated clockwise, the projecting member interacts with the actuator to result in the actuator moving in the first direction to the first position.
The actuator may also be positioned such that when the dial assembly is rotated counter clockwise, the projecting member interacts with the actuator to result in the actuator moving in the second direction to the second position. The rotary switch assembly may have a low profile having a height less than about 6 mm.
The invention will now be described, by way of example only, by reference to the accompanying drawings:
The following description will describe the invention in relation to preferred embodiments of the invention, namely a rotary switch assembly. The invention is in no way limited to these preferred embodiments as they are used purely to exemplify the invention only and variations and modifications are readily apparent without departing from the scope of the invention.
Referring to
In light of the above general description of the rotary switch assembly 100, the parts of the rotary switch assembly 100 will now be described in greater detail. The rotary switch assembly 100 includes the dial assembly 102, a body case 110, a printed wiring board (PWB) 112, a switch 114, and a biasing assembly 116. The body case 110 includes a plurality of walls defining an interior space 118. The body case 110 also includes a plurality of support members 120 adapted to support the printed wiring board 112 within the interior space 118. Mounted to a front wall 122 of the body case 110 is a shaft 124. The shaft 124 may be cylindrical in shape, hollow or solid, and is preferably oriented such that a central axis 126 of the shaft 124 is oriented substantially parallel to the plane of the PWB 112. A push activated switch may be disposed within the hollow of the shaft 124 if desired or in replacement of the shaft 124.
The dial assembly 102 may include the rotary knob 104, a locking member 128, a propeller 130, and a central aperture 132. The rotary knob 104 may be an annular shaped member disposed about the central aperture 132. The central aperture 132 is shaped and configured to rotatingly receive the shaft 124 of the body case 110 and is preferably oriented concentrically with the central axis 126. The rotary knob 104 is adapted to be gripped by the user and rotated in either the clockwise 106 or counter clockwise 108 direction to result in the performance of a selected function by activating selected circuits on the PWB 112.
The locking member 128 may be an annular shaped member disposed about the central aperture 132 and adapted to be coupled to the rotary knob 104. The locking member 128 is also adapted to interface with a locking groove 134 on the shaft 124 to retain the dial assembly 102 upon the shaft 124 after installation.
The propeller 130 may also be an annular shaped member disposed about the central aperture 132 and adapted to be coupled to the rotary knob 104. Referring to
In the illustrated embodiment, the biasing assembly 116 includes a coil spring 148 having ends which are rigidly attached to the body case of the rotary switch assembly 100. The retaining member 140 is formed by the coiling of the wire forming the coil spring 148. Although a particular biasing assembly 116 is illustrated and described, it is noted that many biasing assemblies hereto known or to be developed may be used without departing from the scope of the present invention.
Turning to
More specifically, when the dial assembly is rotated in the clockwise direction 106, the actuator engages and rides along the outer facing cam surface 152 resulting in the actuator moving radially outward from a neutral/default position, to a first position 158, in which a first circuit is activated, resulting in the commencement of a specific routine or function, for instance resulting in an increase in volume or the scrolling through a menu list in a first direction. The actuator 156 is preferably biased into the default position such that when dial assembly 102 is rotated further such that the actuator 156 disengages from the cam surface 152, or is rotated back to its original starting position, the actuator 156 is automatically returned to the default position.
When the dial assembly is rotated in the counter clockwise direction 108, the actuator engages and rides along the inner facing cam surface 154 resulting in the actuator moving radially inward from the neutral/default position, to a second position 160, in which a second circuit is activated, resulting in the commencement of a specific routine or function, for instance resulting in a decrease in volume or the scrolling through a menu list in a new direction. Since the actuator 156 is biased into the default position, when the dial assembly 102 is rotated further such that the actuator 156 disengages from the cam surface 154, or is rotated back to its original starting position, the actuator 156 is automatically returned to the default position. Preferably, the cam surfaces 152 and 154 are inclined relative to the outer circumference or perimeter of the dial assembly such that the distance between the cam surfaces 152 and 154 and the central axis 126 increases along the length of the projecting member 138.
The switch 114 is preferably a two-way direction detector switch. As noted above, the switch 114 includes an actuator 156 that may be selectively moved between a default/normal position to either a first position 158 or a second position 160. The actuator 156 may be biased so that the actuator 156 automatically returns to the default position. When in the first position 158, the switch 114 is adapted to activate a first circuit to result in the accomplishment of a predefined task. Likewise, when the actuator 156 is in the second position 160, the switch 116 is adapted to activate a second circuit to result in the accomplished of a different predetermined task. The switch 114 is preferably attached directly to the PWB 112 which contains all or a portion of the first and second circuits. The actuator 156 is preferably oriented parallel to the central axis 126 when in the default position, and is pivoted about an axis 162 oriented substantially perpendicular to the central axis 126 when transitioned to either the first or second positions 158 and 160.
Turning to
Examining these differences in greater detail, the rotary switch assembly 200 includes a dial assembly 202 formed from a propeller 230. The propeller 230 has a plurality of projecting members 238 which extend radially outward from a main body 250 of the dial assembly 202. The projecting members 238 are sized and positioned to selectively move an actuator 256 of a switch 214 between a first and second position 258 and 260 when the dial assembly 202 is rotated either clockwise 206 or counter clockwise 208. Both the actuator 256 and the projecting members 238 are preferably oriented substantially perpendicular to the central axis 226.
A biasing assembly 216 has a spring 248 which selectively engages recesses disposed in the propeller 230. The recesses are substantially identical to the recesses of the previous described embodiment, and therefore are not illustrated herein for the sake of brevity. Like the previous embodiment, the spring 248 interacts with the recesses to both provide positive feedback to the user during operation and to aid in retaining the propeller 230 in selected positions.
The dial assembly 202 is rotatingly received by the push activated switch assembly 300. More specifically, the push activated switch assembly 300 includes a main body 302 having a stub shaft 324. The stub shaft 324 is adapted to be received within the central aperture 232 of the propeller 230 such that during use, the dial assembly 202 can be selectively rotated about the stub shaft 324 by the user. The main body 302 is retained to the PWB 212 by a series of mounting tabs 306 which lockingly interface with a series of corresponding mounting apertures 308 disposed in the PWB 212.
The push activated switch assembly 300 also includes one or more dome switches 310. The dome switches 310 are adapted to selectively activate or deactivate a circuit when depressed. Moreover, during use, the main body 302 may be selectively depressed and/or tilted out of alignment with axis 226 to depress one of the dome switches 310 to result in the activation or deactivation of a particular circuit on the PWB 212, to result in the performance of a selected task.
Preferably, the height of the rotary switch assembly 200, measured from the bottom of the dome switches 310 or the top surface of the PWB 212 to the top of the stub shaft 324 or propeller 230 is less than about 10 mm, or even smaller heights, such as less than about 8 mm, 6 mm, 4 mm, or 3 mm such that the rotary switch assembly 200 has a low profile. Preferably the propeller 230 has an outer diameter that is less than about 50 mm, or even smaller diameters such as less than about 40, 30, or 20 mm.
A rotary switch assembly formed in accordance with the present invention may provide one or more of the following advantages:
Throughout the description of this specification, the word “comprise” and variations of that word such as “comprising” and “comprises”, are not intended to exclude other elements, components, integers or steps.
It will of course be realised that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the scope of this invention as is hereinbefore described.
| Number | Date | Country | Kind |
|---|---|---|---|
| PI 20064548 | Nov 2006 | MY | national |
