Rotary drive mechanism and appliance timer/sequence switch utilizing same

A rotary drive mechanism adapted to translate linear rise and fall motion of a cam control track to rotary motion, comprising:

• a housing;
• a tracking rod rotatably fixed in said housing;
• means for tracking the cam control track, said tracking means imparting rotary motion to said tracking rod in response to the linear rise and fall of the cam control track;
• an actuating rod rotatably fixed in said housing and having an end thereof extending though said housing;
• rotary motion multiplying means operatively attached to said tracking rod and to said actuating rod for transmitting rotary motion from said tracking rod to said actuating rod, said rotary motion imparted to said actuating rod being a multiple of said rotary motion of said tracking rod.

An appliance timer/sequence switch providing a program-controlled rotary output, comprising:

• a motor having an output shaft;
• a cam drivably coupled to said output shaft, said cam having at least one cam control track on a surface thereof;
• a rotary drive mechanism having a cam control track follower adapted to linearly follow said cam control track, said rotary drive mechanism further having an output actuating rod providing rotary motion corresponding to linear deviations of said cam control track;
• wherein said rotary drive mechanism further comprises a tracking rod drivably coupled to said cam control track follower, said tracking rod being rotated by said cam control track follower during said linear deviations of said cam control track, said tracking rod rotatably driving said actuating rod though a gear set, said gear set having an input to output ratio multiplying rotary motion of said tracking rod to said actuating rod;
• and
• wherein said cam control track follower comprises a tracking lobe extending from said tracking rod, a bias lobe extending from said tracking rod in an angular relationship to said tracking lobe, and a bias spring imparting a bias force on said bias lobe to maintain said cam control track follower in contact with said cam control track.

An appliance timer/sequence switch providing a program-controlled rotary output, comprising:

• a motor having an output shaft;
• a cam drivably coupled to said output shaft, said cam having at least one cam control track on a surface thereof;
• a rotary drive mechanism having a cam control track follower adapted to linearly follow said cam control track, said rotary drive mechanism further having an output actuating rod providing rotary motion corresponding to linear deviations of said cam control track;
• wherein said rotary drive mechanism further comprises a tracking rod drivably coupled to said cam control track follower, said tracking rod being rotated by said cam control track follower during said linear deviations of said cam control track, said tracking rod rotatably driving said actuating rod though a gear set, said gear set having an input to output ratio multiplying rotary motion of said tracking rod to said actuating rod;
• and
• wherein said cam control track follower comprises a torque arm extending from said tracking rod, and a tracker linearly movable within said rotary drive mechanism and in communication with said torque arm, and wherein linear movement of said tracker imparts rotary motion to said tracking rod though said torque arm, and wherein said cam control track follower further comprises a bias spring imparting a bias force on said torque arm acting in opposition to a force applied to said torque arm by the tracker thereby enabling said tracker to maintain contact with said cam control track.

An appliance, comprising:

• a vent having a damper rotatable between an opened and a closed position;
• a program timer operative to control operating cycles of said appliance, said program timer including a motor drivably coupled to a cam having a vent control track on a surface thereof;
• a rotary drive mechanism having a vent control track follower adapted to follow said vent control track, said rotary drive mechanism further having an output actuating rod providing rotary motion corresponding to vent control track;
• and
• a torsional actuator drivably coupled between said output actuating rod and said damper.