Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H19/00—Switches operated by an operating part which is rotatable about a longitudinal axis thereof and which is acted upon directly by a solid body external to the switch, e.g. by a hand
  • H01H19/02—Details
  • H01H19/10—Movable parts; Contacts mounted thereon
  • H01H19/11—Movable parts; Contacts mounted thereon with indexing means
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05G—CONTROL DEVICES OR SYSTEMS INSOFAR AS CHARACTERISED BY MECHANICAL FEATURES ONLY
  • G05G1/00—Controlling members, e.g. knobs or handles; Assemblies or arrangements thereof; Indicating position of controlling members
  • G05G1/08—Controlling members for hand actuation by rotary movement, e.g. hand wheels
  • G05G1/10—Details, e.g. of discs, knobs, wheels or handles
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05G—CONTROL DEVICES OR SYSTEMS INSOFAR AS CHARACTERISED BY MECHANICAL FEATURES ONLY
  • G05G5/00—Means for preventing, limiting or returning the movements of parts of a control mechanism, e.g. locking controlling member
  • G05G5/06—Means for preventing, limiting or returning the movements of parts of a control mechanism, e.g. locking controlling member for holding members in one or a limited number of definite positions only
  • G05G5/065—Means for preventing, limiting or returning the movements of parts of a control mechanism, e.g. locking controlling member for holding members in one or a limited number of definite positions only using a spring-loaded ball
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H19/00—Switches operated by an operating part which is rotatable about a longitudinal axis thereof and which is acted upon directly by a solid body external to the switch, e.g. by a hand
  • H01H19/54—Switches operated by an operating part which is rotatable about a longitudinal axis thereof and which is acted upon directly by a solid body external to the switch, e.g. by a hand the operating part having at least five or an unspecified number of operative positions
  • H01H19/56—Angularly-movable actuating part carrying contacts, e.g. drum switch
  • H01H19/58—Angularly-movable actuating part carrying contacts, e.g. drum switch having only axial contact pressure, e.g. disc switch, wafer switch
  • H01H19/585—Angularly-movable actuating part carrying contacts, e.g. drum switch having only axial contact pressure, e.g. disc switch, wafer switch provided with printed circuit contacts

Definitions

• the field of the invention is electromechanical rotary switches.
• a rotary electromechanical switch is generally defined 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.
• a rotary electromechanical encoder includes the overall characteristics of a rotary switch, but has additional mechanical movements. In any case, a user typically manipulates the switch to manually select a circuit.
• Rotary switches and encoders 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 has become increasingly smaller and there has become a need to reduce the size of the switch - especially that portion on the inside of the panel.
• U.S. Patent 6043855 to Grave (March 2000) is directed toward switches that mount on a bezel surrounding an LCD which is located on an avionics panel in an aircraft.
• the '855 patent teaches a design in which the detent is at least partially positioned in the knob of the switch. Still, the design of the '855 patent has its shortcomings: the detent is housed by the knob such that if the knob were to be displaced, the switch would not function or would function improperly; the detent is not entirely within the knob; the design requires two springs; and the springs are mounted vertically adding to the overall vertical profile of the knob.
• the inventive subject matter is a panel mounted low profile switch having a detent sub-assembly housed in a bushing.
• the portion of the bushing housing the spring is in substantial planar relation with the panel within which the switch is mounted.
• the detent sub-assembly comprises a single spring positioned vertically in the vertical extending shaft.
• Fig. 1 is a perspective view of an exploded rotary switch.
• Fig 2 is a perspective view of an exploded rotary switch.
• Fig. 3 is a perspective view of an exploded rotary switch.
• Fig. 1 depicts a rotary switch 100 generally comprised of a bushing 110, a detent mechanism 120, a shaft 130, an electrical contact 140, and a printed circuit board (PCB) 150.
• PCB printed circuit board
• Bushing 110 is comprised of a threaded upper portion 112 and a lower portion 114.
• a bushing is a component of a switch that is used to hold the switch to a panel (e.g. a control borad) through which the switch is mounted.
• a preferred bushing has an upper portion that extends through a hole in the panel and a lower portion that contacts the underside (i.e. non-user side) of the panel.
• bushing 110 has a threaded upper portion 112 that extends through hole 164 in the panel 160.
• the lower portion 114 is of a diameter and/or shape that will not fit through the hole 164 in the panel 160.
• a lock washer 172 is placed over the upper portion of the bushing 112 and the capture nut 170 is threaded to the upper portion 112 in order to hold the switch to the panel. It is not required that a bushing be threaded and that a nut be used to hold the switch to the panel as non-threaded bushings may also be used. A non-threaded bushing can be held to the panel in other ways, for example by using rivets or compression fittings.
• a bushing should not rotate, and herein there are provided means for substantially prohibiting such rotational movement.
• One such means is a pin/aperture configuration in which the pin 116 fits snugly within an aperture 162 in the panel.
• the hole in the panel and the associated upper portion of the bushing may have two or more flat sides.
• a detent sub-assembly is comprised of the detent mechanism 120 having rotors 121, a spring 122, and a ball 124. Further analysis of the switch depicted in Fig. 1 reveals a single spring detent sub-assembly in which the spring 122 is horizontally disposed (i.e perpendicular to the shaft). The spring is in contact (direct or indirect) with at least one ball 124. Note that in some horizontal single spring embodiments two balls may be utilized, one on each end of the spring. In any case, the ball 124 is biased toward the inner surface of the detent mechanism 120.
• rotor cams i.e. cylindrical lobes
• the ball(s) rotates about the rotor cams as the electrical contact 140 rotates about the PCB 150.
• the detent sub-assembly is housed within the bushing 110, preferably within the upper portion of the bushing 112. However, it is envisaged that a portion of the detent sub-assembly may extend into the lower portion of the bushing.
• the detent mechanism be prevented from rotation within the bushing.
• the detent mechanism 120 can have an extrusion 126 that engages a notch (not shown) on the inner surface of the bushing thereby preventing such rotation.
• the shaft is intended to rotate, however, it can be advantageous to limit the rotation of the shaft. Limiting rotation of the shaft can be accomplished by using a pin 132 to limit the degree of rotation as a function of the size of a notch 128 in the detent mechanism. By limiting the rotation of the shaft, the available switch settings can be limited.
• An electrical contact 140 (e.g. switch wipers or brushes) is mounted on a non- conductive disc 135 (i.e. dielectric) and the contact 140 cooperates with the circuit configuration on the PCB 150.
• the PCB 150 is anchored to the bushing 110 by metal rivets 190 or other connectors, however it should be noted that anchoring of the PCB to the bushing is not a requirement.
• a PCB can contain additional electronic components (e.g. chips, pins, leads, and so forth) that may interface with components other than the switch. Setting of a switch position, therefore, is generally a function of the interaction among the detent sub-assembly, the shaft, the electrical contact and the PCB.
• an alternative embodiment includes a vertical spring 220 (i.e. parallel to the shaft), a set screw 210, and a plunger 230.
• the single vertical spring 220 is housed within the shaft and is elongated in the same direction as the shaft.
• the set screw 210 is threaded into the upper portion 212 of the shaft 130 thereby causing the plunger to exert outward pressure on the balls 240.
• the outward pressure biases the balls in the direction of the rotor cams on the inner surface of the detent mechanism 120. It should be noted that outward tension against the balls can be adjusted by threading or unthreading the set screw.
• a plunger is preferably cylindrical in shape and pointed. The preferred plunger not only provides uniform pressure to the balls, but it also allows for more than two balls to be used with a single spring.
• a switch can be configured to set a plurality of electrical settings.
• Fig. 3 depicts a multiple deck switch having a vertical spring configuration. The embodiment of Fig. 3 has two sets of contacts and two PCBs. The first set of contacts 140 is attached to a non- conductive (dielectric) disc 310 which is further coupled to the shaft 130. A second non- conductive disc 320 is also coupled to the shaft 130 and is further coupled to a second set of contacts 330. A spacer 340 provides insulation between the PCBs.
• the shaft of a switch is generally rotated by manual movement in order to set a switch position.
• Switch positions are defined by the rotor cams (lobes) in the detent mechanism.
• a ball protruding from the shaft will set in the area between two rotor cams thereby defining a switch position.
• a user of the switch will be able to feel the ball set between the rotor cams.
• the contacts form electrical connections based on the relationship between the contact and the PCB. While the switches enumerated here are shown with a stop pin to limit the rotation of the shaft, this is not a requirement as some switches will allow 360 degree rotation in both directions.
• Methods of use include mounting a rotary switch such that the detent sub-assembly is in planar relation to a panel. Since most of the upper portion of the bushing is on the user's side of the panel, however, the detent sub-assembly may be substantially on the user's side of the panel rather than in a plane with the panel. Additionally, there may even be a portion of the detent sub-assembly which extends underside of the panel. Thus, a single detent sub- assembly may be positioned such that a portion of the detent sub-assembly is above the panel, a portion is parallel with the panel, and a portion is below the panel.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Automation & Control Theory (AREA)
• Rotary Switch, Piano Key Switch, And Lever Switch (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=32311638

Family Applications (1)

Country Status (6)

Cited By (1)

Family Cites Families (9)

• 2003
  • 2003-07-17 WO PCT/US2003/022523 patent/WO2004044938A1/en not_active Ceased
  • 2003-07-17 EP EP03811194A patent/EP1559121A4/de not_active Withdrawn
  • 2003-07-17 AU AU2003252041A patent/AU2003252041A1/en not_active Abandoned
  • 2003-07-17 BR BR0314134-9A patent/BR0314134A/pt not_active IP Right Cessation
  • 2003-07-17 CA CA002496034A patent/CA2496034A1/en not_active Abandoned
  • 2003-07-17 JP JP2004551425A patent/JP2006501628A/ja active Pending

Also Published As

Similar Documents

Legal Events