Control system for freezers

Claim 2

A freezer apparatus comprising an evaporator, including a freezing tube to which the product to be frozen is supplied, first conduit means for conducting liquid product to said freezing tube, second conduit means for conducting frozen product away from said freezing tube, pump means in said first conduit means for supplying product to said freezing tube, dasher means within said freezing tube for agitating said product during cooling thereof, single motor means for driving both said dasher means and said pump means, a first supply line to carry liquid refrigerant to said freezing tube, a second supply line to carry hot refrigerant gas to said freezing tube, a normally closed valve in sad second supply line, a refrigerant discharge line leading from said freezing tube to carry gaseous refrigerant therefrom, pressure regulator means in said refrigerant discharge line to control pressure at preselected values, first timing means to inactivate said pressure regulator means for a first predetermined period and provide a maximum flow of liquid refrigerant to said freezing tube during said first predetermined period and second timing means for delaying activation of said motor means for a second predetermined period occurring during at least a portion of the time period of said first predetermined period.

Claim 3

A freezing apparatus in accordance with claim 1 wherein said first timing means and said second timing means are activated upon start-up of the freezing apparatus.

Claim 4

A freezing apparatus in accordance with claim 1 which further includes third timing means for controlling the opening of said valve in said second supply for a predetermined period.

Claim 5

A freezing apparatus in accordance with claim 3 wherein said third timing means is activated upon shut-down of the freezing apparatus.

Claim 6

A freezing apparatus in accordance with claim 1 which further comprises throttle valve means in said second conduit means and pressure sensing means in said first conduit means, said pressure sensing means controlling said throttle valve means at preselected values to control the softness of said frozen product.

Claim 7

An electrical control circuit for freezing apparatus having an evaporator including a freezing tube, a pump to supply liquid product to the freezing tube, a dasher within the freezing tube to agitate the product while it is being frozen, a single motor for driving both the pump and the dasher, a pressure regulator for controlling the pressure of refrigerant supplied to the evaporator, an adjustable valve for controlling a pressure signal to the pressure regulator, a bypass line around the adjustable valve, a first solenoid controlled valve in the bypass line, a second solenoid controlled valve for controlling the supply of refrigerant to the evaporator, and a third solenoid controlled valve for controlling the supply of hot gas to the evaporator, said control circuit comprising an electrical power source, a stop switch, a start switch, a main holding coil connected in series with said start and stop switches across said power source, first and second solenoids for said first and second solenoid controlled valves to open said valves when the respective solenoid is energized, a first time control relay and a second time control relay, said main holding coil being energized when said start switch is pressed, said first and second time control relays being energized by said main holding Coil, first and second solenoid being controlled by said first time control relay, said motor starter circuit having a set of contacts operated by said second time control relay, said first and second time control relays being set in a way so that said first and second solenoids are opened a predetermined period before said motor starter circuit is energized.

Claim 8

An electrical control circuit for freezing apparatus having an evaporator including a freezing tube, a pump to supply liquid product to the freezing tube, a dasher within the freezing tube to agitate the product while it is being frozen, a single motor for driving both the pump and the dasher, a pressure regulator for controlling the pressure of refrigerant supplied to the evaporator, an adjustable valve for controlling a pressure signal to the pressure regulator, a bypass line around the adjustable valve, a first solenoid controlled valve in the bypass line, a second solenoid controlled valve for controlling the supply of refrigerant to the evaporator, and a third solenoid controlled valve for controlling the supply of hot gas to the evaporator, said control circuit comprising an electrical power source, a stop switch, a start switch, a main holding coil connected in series with said start and stop switches across said power source, first and second solenoids for said first and second solenoid controlled valves to open said valves when the respective solenoid is energized, a first time control relay and a second time control relay, said main holding coil being energized when said start switch is pressed, said first and second time control relays being energized by said main holding Coil, first and second solenoid being controlled by said first time control relay, said motor starter circuit having a set of contacts operated by said second time control relay, said first and second time control relays being set in a way so that said first and second solenoids are opened a predetermined period before said motor starter circuit is energized.

Claim 9

An electrical control circuit in accordance with claim 6 which further comprises a third solenoid for controlling said third valve and a third time control relay, said third time control relay being energized when said stop button is pressed and said third time solenoid being controlled by said third time control relay so as to admit hot gas to the evaporator for a predetermined period of time.