Eaton Corporation

The Singer Company

Deltrol Corp.

Joseph J Mahon

Robert K Aigner

William H Redfield

Robert A Livernash

Ignacy Supel

A torque limiting drive and programmer/timer using same. A motor drives a driving member which has drive lugs engaging the central web of a plural-armed wave spring. The wave spring arms frictionally engaged radially oppositely facing annular friction surfaces on a driven member, which in a programmer/timer is the program cam, which upon rotation of the cam is operative for sequentially actuating electrical switches. User rotation of the cam when the motor is not operative allows the wave spring arms to slip against the annular friction surfaces permitting the user to position the cam as desired.

Torque limiting drive and programmer/timer employing same

A programmer for an appliance having a single timing motor drive for a rotating cam drum which actuates plural appliance program function switches. An advance pawl drives the cam drum in one direction when selectively engaged with a toothed wheel on the drum and drives through a first rotary frictional coupling. A gear train drives continuously through a second rotary frictional coupling and drives the cam drum in a reverse direction when the advance pawl is disengaged. When the pawl is engaged, the second rotary frictional coupling slips and is overdriven in a direction opposite its driving direction by said first frictional coupling.

Appliance programmer/timer with bi-directional drive

A programmer/timer for an appliance of the type having a rotatable cam drum advanced for sequential actuation and deactuation of a plurality of electrical switches. The drum is advanced or indexed intermittently by an oscillating advance pawl engaging a ratchet wheel and also continuously by a gear driven by a common motor for oscillating the advance pawl. The ratchet wheel has a hub which is frictionally engaged to drive the cam drum. The driven gear in turn is frictionally engaged with the hub to also drive the ratchet wheel. When the advance pawl engages the ratchet wheel for intermittent drive, the driven gear slips on the ratchet hub. Upon user selection, a separate cam track lifts the advance pawl to permit the driven gear to continuously drive the ratchet wheel.

Providing a programmer/timer with dual rate drive

A programmer/timer for an appliance of the type having a rotatable program cam advanced by an oscillating pawl engaging a ratchet wheel for actuating at least one appliance function switch. A shaft is provided for enabling user positioning of the cam after limited rotational lost-motion for selecting the program interval. An annular member having a conical cam surface is received over the shaft and is helically cammed to the shaft. During the limited lost-motion rotation of the shaft, the collar moves axially and the conical cam surface lifts the pawl from the ratchet thereafter enabling user rotation of the program cam for positioning same for program interval selection.

Bi-directional setting of a programmer timer

A programmer timer for an appliance, such as microwave cooking oven, having a magnetron power switch positioned by a control selectively moved to one of three power level settings by user rotation of the single rotary knob to a selected position on one of three separate cooking program interval range scales on the dial. Selection of a knob position on the first scale provides a 100% magnetron duty cycle, or full 'ON', cooking mode for the desired cooking interval, selection of a knob position on the second scale provides a first predetermined fractional duty cycle for 'MEDIUM' power level magnetron operation for the desired cooking interval; and, selection of a knob position on the third scale provides a second predetermined fractional duty cycle for 'LOW' or 'DEFROST' power level magnetron operation for the desired cooking program interval. A single timing motor drives a cam advance mechanism for effecting time-out of the selected program interval for the three power levels of operation.

Microwave oven timer

A timing control system and timer sub-assembly for microwave cooking source parallel connected with a timer and series connected with an interval time switch and a defrost cycle switch and a power level selector. The timer is operable to cycle the defrost switch at a fast rate for selected operating timer intervals of a given value or greater and a slow rate for selected interval less than the given value. The timer provides progressively decreasing 'on' time of the defrost cycle switch for each cycle. The timer sub-assembly has a pawl-driven ratchet wheel having a toothed sector of lesser pitch diameter and a masking ratchet wheel having periodic deep notches spaced thereabout for permitting the drive pawl to periodically engage the teeth of lesser pitch diameter for slower advance of the driven ratchet wheel for indexing a plurality of rotary cam tracks for microwave source switch actuation.

Electrical appliance programming

A plug-in power transmission assembly having a housing with a gear train and with a motor mounted on one side and the output drive shaft extending from the opposite side. The motor has connectors thereon which are received through guides on the housing and extend outwardly in a common direction with the output shaft axis. Releasable fastening means are provided on the output shaft side of the housing. The assembly, as a unit is plugged into a device to be driven and the output shaft, electrical connectors and fastening means are simultaneously engaged.

Method of assembling a motor speed reducer to a device to be driven

A push button member (10) is mounted to be moved longitudinally between a first position (FIG. 1A) and a second position (FIG. 1B). The push button member includes a cam surface (16) for selectively camming an electrical contact engaging surface (18) and a hold surface (48) past a follower member (32) as the push button member is moved from the first position to the second position. In the second position, the electrical contact engaging surface urges electrical leaf spring contacts (20) into a closed conducting relationship. The spring contacts remain in the conducting relationship until a radially greater extending cam surface (52) of a timing cam (50) engages the follower member moving it to the release position. In the release position, a spring (12) biases the push button member from the second position back to the first position allowing the electrical contacts to open.

Latching push button switch

A single timing motor (26) drives a gear box (54) having an output shaft (56) for indexing a ratchet wheel (62) for turning a cam drum (68). One cam track (72) operates a line switch (22) for controlling the program interval 'ON' time of the appliance. A second cam track (70) operates a second line switch (40) for controlling the timing motor. A toothless space (66) in the ratchet wheel stalls cam drum advance upon program interval time-out to maintain the timer switch (40) closed to keep the motor running. Output shaft 56 drives a sub-interval cam (80) which cycles a switch (48) for effecting intermittent appliance 'ON' time for a minor portion of the sub-interval period to provide a 'KEEP-WARM' mode of operation. An alarm bell (100) is sounded by a striker (98) actuated by the sub-interval cam. The operator manually advances the cam drum (68) for de-actuating the timer motor switch (40). A manual mode-selector switch (34) enables by-passing the sub-interval switch (48) to select either the 'COOK' only mode of operation or 'COOK' and 'KEEP-WARM' modes.

'Keep warm' control

A control system and programmer/timer for a microwave oven having a program cam advanced by a pawl-stepped ratchet wheel having three toothed segments, each with teeth of differing root diameter. The outer teeth provide rapid expanded scale advancement for the terminal five minutes of the cooking program and also for selected programs of five minutes or less for high-resolution switching by the program cam. The segment of teeth of intermediate root diameter provides a compressed scale slower cam advance rate for 'COOK' programs of 5-35 minutes. The segment of teeth of lowest root diameter provides slow rate cam advancement for auxiliary 'DELAYED START' and KEEP-WARM functions where time accuracy is not critical. The programmer/timer enables continued advancement of the program cam after time-out of the cooking program where the KEEP-WARM mode has been preselected.

Appliance control and programmer timer therefor

A timing control system and timer sub-assembly for microwave cooking source parallel connected with a timer and series connected with an interval time switch and a defrost cycle switch and a power level selector. The timer is operable to cycle the defrost switch at a fast rate for selected operating timer intervals of a given value or greater and a slow rate for selected interval less than the given value. The timer provides progressively decreasing 'on' time of the defrost cycle switch for each cycle. The timer sub-assembly has a pawl-driven ratchet wheel having a toothed sector of lesser pitch diameter and a masking ratchet wheel having periodic deep notches spaced thereabout for permitting the drive pawl to periodically engage the teeth lesser pitch diameter for slower advance of the driven ratchet wheel for indexing a plurality of rotary cam tracks for microwave sources switch actuation.

The timer motor drives a non-circular drive gear fixed on the same shaft as the final gear of the reduction gear train. The final gear is driven by a pinion which is mounted on an axially movable spring loaded jackshaft on which a large gear is mounted with clutch members on the pinion and large gear. When the timer is set the shaft carrying the driven non-circular gear and cam is depressed causing the cam face to depress the jackshaft to disengage the clutch permitting easy rotation of the cam to the desired starting point. The angular motion of the driven non-circular gear and cam is substantially logarithmic with the angular motion increasing as 'zero' is approached. When the timer is set the switch is closed to start the motor and the timed device. The lever carrying the cam follower is spring loaded to urge the follower against the cam and to take up the motion in the pin and slot pivot for the lever. When the follower drops into the notch at zero the lever pivots rapidly, hits the fixed stop and pivots about the stop using the motion in the pin and slot. This lets the striker end of the lever hit the bell and then the lever bias spring again takes up the motion to pull the lever off the bell and let the bell 'ring' while the fixed stop holds the lever off the bell. The follower is pivoted so during the initial set motion it moves to present an incline to the cam allowing the cam to push the follower out of the notch.

Expanded scale timer

The follower tip of the switch operating bell-crank lever can ride on the large diameter of the axially movable, rotatably driven cam or on axial movement of the cam can drop onto the smaller diameter of the cam to close one switch and, upon further axial movement, the follower can move further in to a pseudo inner diameter to close a second switch. The lever acts to prevent return axial movement of the cam until the cam notch is aligned with the follower and the follower no longer interferes with axial movement.

Percentage timer

A continuous repeat cycle timer in which the on period is externally adjustable. The beginning of the on period is fixed, being started by a cam follower dropping into a notch in the periphery of a cam. The end of the on period is determined by axial movement of a second cam which releases a latch. The point of axial latch releasing movement is set by an adjusting cam which is rotatable by an external knob. The cam shaft for the operating cams extends through the knob and indicates the progress of the time cycle.

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Libertyville, IL, United States of America

Joseph J Mahon