Refrigerator control apparatus

Claim 2

In apparatus for controlling the defrosting of a refrigeration system which includes a compressor, fan, and heater, the combination comprising control means for independently and selectively controlling said compressor, fan and heater, actuating means for selectively actuating said control means, means for initiating operation of said actuating means upon occurrence of an event, thereby to initiate a defrosting cycle of said refrigeration system, said actuating means and said control means being constructed and arranged to turn off said compressor and fan and turn on said heater upon a first actuation by the initiating means in a defrosting cycle of operation, to turn on said compressor and turn off said heater at a second actuation, and to turn on said fan at a later third actuation thereof, a temperature sensing-switching circuit for sensing temperature in a part of said refrigeration system and for providing a first switching function when a predetermined maximum defrosting temperature is sensed and for providing a second switching function when a predetermined lower temperature is sensed, motor means selectively operable in response to said temperature sensing-switching circuit for operating said actuating means, and means for further selectively operating the motor means only during the existence of said first switching function to provide only said second actuation to the actuating means and for selectively operating the motor means only during the existence of said second switching function to provide only said third actuation to the actuating means.

Claim 3

The apparatus claimed in claim 1 wherein said temperature sensing-switching circuit includes first switch means providing a single pole double throw switch function and which is operated to a first condition upon the sensing of said maximum temperature and which is operated to a secoNd condition upon the sensing of said lower temperature, and wherein the means for further selectively operating the motor means comprises second switch means providing a single pole double throw switch function, said means for further selectively operating the motor means including means responsive to the operation of said motor means for operating the second switch means from a first to a second switch condition after the heater is turned off and for operating the second switch means from its second to its first switch condition after said fan is turned on.

Claim 4

The apparatus claimed in claim 2 wherein said second named means responsive to the operation of the motor means comprises cam means rotatable by said motor means when the motor means operates the actuating means and a cam follower for operating the second switch means.

Claim 5

The apparatus claimed in claim 3 wherein said motor means includes an independent motive source coupled to a source of electrical supply through said first and second switch means.

Claim 6

The apparatus claimed in claim 4 wherein said first and second switch means each is comprised of first and second stationary contacts and a movable contact, the first and second stationary contacts of said two switch means being, respectively, connected together and the movable contact of one switch means being connected to one side of a source of electrical supply and the movable contact of the other switch means being connected through said motive source to the other side of said source of electrical supply.

Claim 7

The apparatus claimed in claim 3 wherein said means for initiating operation of said actuating means upon occurrence of an event is a timing motor having positionable tappets associated therewith, and wherein 1 said motor means includes coupling means driven by said timing motor and selectively engageable with said actuating means for operating the actuating means when so engaged, said motor means further including means responsive to the output of said temperature sensing-switching circuit for causing selective engagement of the coupling means with said actuating means.

Claim 8

In apparatus for controlling the defrosting of a refrigeration system which includes a compressor, fan and heater, the combination comprising control means for independently and selectively controlling said compressor, fan and heater, actuating means for selectively actuating said control means, means for initiating operation of said actuating means upon occurrence of an event, thereby to initiate a defrosting cycle of said refrigeration system, said actuating means and said control means being constructed and arranged to turn off said compressor and fan and turn on said heater upon a first actuation by the initiating means, to turn on said compressor and turn off said heater upon a second actuation, and to turn on said fan upon a third actuation thereof, temperature sensing means for sensing a predetermined maximum temperature in a part of the refrigeration system, circuit means responsive to said sensing means for producing an output signal of given characteristic when said maximum temperature is sensed, motor means operable in response to said out-put signal of given characteristic to operate said actuating means to turn off the heater and turn on the compressor, switching means for further controlling the operation of said motor means, means operable in response to said motor means for actuating the switching means to interrupt operation of the actuating means by said motor means after the compressor is again turned on, said sensing means and said circuit means being operable to sense a predetermined temperature lower than said maximum temperature and upon sensing said lower temperature operating with said switching means to reactivate operation of the actuating means by the motor means to turn on said fan, said means operable in response to the motor means being responsive to said reactivation of the motor means to operate said switching means to again turn off the motor means after the fan is turned on.

Claim 9

In apparatus for controlling the defrosting of a refrigeration system which includes a compressor, fan and heater, the combination comprising control means for independently and selectively controlling said compressor, fan and heater, actuating means for selectively actuating said control means, means for initiating operation of said actuating means upon occurrence of an event, thereby to initiate a defrosting cycle of said refrigeration system, said actuating means and said control means being constructed and arranged to turn off said compressor and fan and turn on said heater upon a first actuation by the initiating means, to turn on said compressor and turn off said heater upon a second actuation, and to turn on said fan upon a third actuation thereof, temperature sensing means for sensing a predetermined maximum temperature in a part of the refrigeration system, circuit means responsive to said sensing means for producing an output signal of given characteristic when said maximum temperature is sensed, motor means operable in response to said out-put signal of given characteristic to operate said actuating means to turn off the heater and turn on the compressor, switching means for further controlling the operation of said motor means, means operable in response to said motor means for actuating the switching means to interrupt operation of the actuating means by said motor means after the compressor is again turned on, said sensing means and said circuit means being operable to sense a predetermined temperature lower than said maximum temperature and upon sensing said lower temperature operating with said switching means to reactivate operation of the actuating means by the motor means to turn on said fan, said means operable in response to the motor means being responsive to said reactivation of the motor means to operate said switching means to again turn off the motor means after the fan is turned on.

Claim 10

In apparatus for controlling the defrosting of a refrigeration system which includes a compressor, fan and heater, the combination comprising switch means for independently and selectively controlling said compressor, fan and heater, switch actuating means for selectively actuating said switch means, timing means for initiating operation of said switch actuating means thereby to initiate a defrosting cycle of said refrigeration system, said switch actuating means and said switch means being constructed and arranged to switch off said compressor and fan and switch on said heater upon a first actuation by the timing means in a defrosting cycle of operation, to switch on said compressor and switch off said heater at a subsequent actuation, and to switch on said fan at a still later actuation thereof, temperature sensing means for sensing a predetermined maximum temperature in a part of the refrigeration system, circuit means responsive to said sensing means for producing an output signal of given characteristic when said maximum temperature is sensed, motor means operable in response to said output signal of given characteristic to operate said switch actuating means to switch off the heater and switch on the compressor, second switching means for further controlling the operation of said motor means, means operable in response to said motor means for actuating the second switching means to stop the operation of said motor means after the compressor is again turned on, said sensing means and said circuit means being operable to sense a predetermined temperature lower than said maximum temperature and upon sensing said lower temperature operating with said second switching means to reactivate said motor means to operate the switch actuating means to turn on said fan, said means operable in response to the motor means being responsive to said reactivation of the motor means to operate said second switching means to again switch off the motor means after the fan is switched on.

Claim 11

In apparatus for controlling the defrosting of a refrigeration system which includes a compressor, fan and heater, the combination comprising switch means for independently and selectively controlling said compressor, fan and heater, switch actuating means for selectively actuating said switch means, timing means for initiating operation of said switch actuating means thereby to initiate a defrosting cycle of said refrigeration system, said switch actuating means and said switch means being constructed and arranged to switch off said compressor and fan and switch on said heater upon a first actuation by the timing means in a defrosting cycle of operation, to switch on said compressor and switch off said heater at a subsequent actuation, and to switch on said fan at a still later actuation thereof, temperature sensing means for sensing a predetermined maximum temperature in a part of the refrigeration system, circuit means responsive to said sensing means for producing an output signal of given characteristic when said maximum temperature is sensed, motor means operable in response to said output signal of given characteristic to operate said switch actuating means to switch off the heater and switch on the compressor, second switching means for further controlling the operation of said motor means, means operable in response to said motor means for actuating the second switching means to stop the operation of said motor means after the compressor is again turned on, said sensing means and said circuit means being operable to sense a predetermined temperature lower than said maximum temperature and upon sensing said lower temperature operating with said second switching means to reactivate said motor means to operate the switch actuating means to turn on said fan, said means operable in response to the motor means being responsive to said reactivation of the motor means to operate said second switching means to again switch off the motor means after the fan is switched on.

Claim 12

The combination claimed in claim 8 wherein said motor means includes an independent motive means whose energization from a source is controlled through said first and second switching means connected in series.

Claim 13

The combination claimed in claim 8 wherein said timing means includes a clock motor, and wherein said motor means includes coupling means driven by said clock motor and selectively engageable with said switch actuating means for operating said switch actuating means when so engaged, said motor means further including means responsive to said circuit means for causing selective engagement of the coupling means with said switch actuating means.

Claim 14

The combination claimed in claim 8 wherein said switch means includes switch arms carrying one or more contacts thereon and said switch actuating means comprises rotatable cam members engaged with said switch arms for selectively moving said arms to selectively make and break contacts upon predetermined rotation of said cams.

Claim 15

The combination claimed in claim 11 wherein said means operable in response to said motor means is a second cam means and a switch arm of said second switching means, said second cam being rotatable with said first mentioned cam means.

Claim 16

The combination claimed in claim 11 wherein said switch actuating means include ratchet teeth, and wherein said motor means includes a pivoted pawl engageable with said ratchet teeth for rotating said cams, said motor means further including an electric motor and linkage means coupled to said pawl, said electric motor being responsive to the output of said circuit means to actuate said pawl when the sensing means senses said predetermined temperature and said lower temperature.

Claim 17

In a method of controlling the defrosting of a refrigeration system havinG a compressor, fan and heater which are independently and selectively connectable to a source of electrical supply through respective switches, and wherein the opening and closing of said switches is controlled by respective rotatable cams which are rotated together by motor means, the steps comprising positioning the cams and switches to connect the compressor and fan to said source and to disconnect the heater therefrom, rotating said cams upon occurrence of a predetermined event and disconnecting the compressor and fan from the source and connecting the heater to said source, sensing the temperature in a given part of said refrigeration system, actuating said motor means and turning said cams when the sensed temperature reaches a predetermined maximum temperature, disconnecting said heater and reconnecting said compressor to said source upon turning of the cams through a given angle in response to the sensing of said maximum temperature, interrupting the operation of said motor means and the turning of said cams after the heater is disconnected, reactuating said motor means and again turning the cams when the temperature in said part of the system falls to a predetermined lower temperature, reconnecting the fan to said source upon further turning of the cams through some angle, and again interrupting the operation of the motor means and the turning of the cams after the fan has been connected.

Claim 18

In a method of controlling the defrosting of a refrigeration system havinG a compressor, fan and heater which are independently and selectively connectable to a source of electrical supply through respective switches, and wherein the opening and closing of said switches is controlled by respective rotatable cams which are rotated together by motor means, the steps comprising positioning the cams and switches to connect the compressor and fan to said source and to disconnect the heater therefrom, rotating said cams upon occurrence of a predetermined event and disconnecting the compressor and fan from the source and connecting the heater to said source, sensing the temperature in a given part of said refrigeration system, actuating said motor means and turning said cams when the sensed temperature reaches a predetermined maximum temperature, disconnecting said heater and reconnecting said compressor to said source upon turning of the cams through a given angle in response to the sensing of said maximum temperature, interrupting the operation of said motor means and the turning of said cams after the heater is disconnected, reactuating said motor means and again turning the cams when the temperature in said part of the system falls to a predetermined lower temperature, reconnecting the fan to said source upon further turning of the cams through some angle, and again interrupting the operation of the motor means and the turning of the cams after the fan has been connected.

Claim 19

The method claimed in claim 14 wherein the steps of interrupting the operation of the motor means includes the steps of actuating a second switching means in the control circuit of the motor means in response to a predetermined angular rotation of a cam means which turns in response to operation of the motor means.