DE2128230A1 - Household refrigerator - Google Patents

Description

Dr. rer. near Horst pupil PATENT ADVOCATE

6 Frankfurt / Main 1, Ij. June 1971

Niddastraße 52 Dr. Sb. / dl

Telephone (0611) 237220 Postscheck-Account: 282420 Frankfurt / M. Bank account: 225/0389 Deutsche Bank AG, Frankfurt / M.

18O4-9D-HR-889O

GENERAL ELECTRIC COMPANY

1 River Road
Schenectady, NY / USA

Household refrigerator

The present invention relates to a domestic refrigerator with means for dispensing ice outside the cabinet.

In the parallel application (USA, Serial No .: M 272 of June 8th 1970) a household refrigerator with a freezer compartment is described and claimed, which is a combination of ice storage containers, Includes dispenser, crusher, and means of passage for receiving ice from the dispenser and for conveying the ice

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Ice either in cubes or crushed in a service room on an outer surface of the cabinet. In addition to funds that are on the outer surface of the closet are provided for power supply for the combination dispenser and crusher, is also a safety switch or Control means for interrupting the operation of the dispenser and the crusher are provided if an arm or another elongated one Part is inserted into the end piece of the ice passage adjacent to the control room. The security control means of the The above-mentioned parallel application includes in its broadest scope any suitable sensor connected to the passage, such as those for pressure or capacitance, or preferably a photoelectric circuit means.

The present invention is particularly concerned with a safety control means that includes a capacitance sensor which is suitable for interrupting the operation of the dispenser and the crusher if this results in a change in capacity, caused by an in the control room end piece of the ice passage inserted arm or another extended one Part, is determined.

In accordance with the illustrated embodiment of the present invention there is provided a refrigerator which includes insulated walls including a door forming a normally closed freezer compartment, the compartment containing a combination of ice dispenser and crusher, with a dispensing opening from the breaking mechanism adjacent inner surface of the door is present. The door includes an ice dispensing passage therethrough for receiving ice from the dispensing opening and conveying that ice to a service room on the external surface of the door. In addition to a working means, which includes an actuating means located outside the cabinet for actuating the ice cream dispenser - ₃ , a control means is also provided, which is provided by an arm inserted into the service room end piece of the passage or another

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longer electrically conductive part is activated to prevent the dispenser from operating. This safety control means comprises a proximity indicator circuit which includes a sensor plate or electrode connected to the passage and is adapted to prevent the dispenser and crusher from operating when the sensor plate capacitance increases due to the approach of an electrically conductive body. The circuit comprises a sensor circuit and a relaxation oscillator circuit for supplying a pulsating DC voltage for the Meßfühlerstromkreis, each of said circuits containing substantially a i anode silicon controlled rectifier or an equivalent element. The circuit is particularly characterized in that it is insensitive to the voltage polarity of the current source and relatively insensitive to ohmic input signals compared to capacitive input signals.

Reference is made below to the drawing, in which, for example, embodiments of the invention are shown are. Show in detail:

Fig. 1 is a vertical cross section of part of the invention Refrigerator with ice supply, I.

Fig. 2 is a schematic diagram of part of the electrical control circuit for controlling the automatic operation the ice cream dispenser according to the present invention,

Figure 3 is a plot of the various voltage waveforms of the circuit according to Fig. 2,

4 shows another output part of the control circuit,

FIG. 5 is a functionally equivalent form of the sensing portion of the circuit of FIG.

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Although the safety control according to the invention can be used in every household refrigerator with an external ice control ₃ , it will be described in detail below in its application in a refrigerator, free of which the front or access wall is formed by a door which closes the access opening to a freezer compartment.

In detail, the invention is applied to a Cabinet described, which a closed by a door 2 freezer compartment 1 in addition to a compartment, not shown for Contains fresh food. The door 2 comprises an outer panel 3 which forms the outer surface of the door and a Has recess 4, which essentially forms a service room in which the ice outside the cabinet of a Ice dispenser 5 is supplied, which is arranged inside the freezer compartment above the recess 4.

The ice dispenser 5 can dispense both crushed ice and, optionally, crushed or cube-shaped ice. Briefly, the ice dispenser comprises a container 7 for receiving and storing pieces of ice, commonly referred to as ice cubes, which are produced by an automatic ice dispenser. 8 ready and rotatable dispensing means 9, which are arranged in the container μηα driven by a motor 10 via a speed reducer 11, are produced. As a result of the rotary movement of the dispensing means, the ice cubes stored in the container are conveyed in batches of two or three cubes through an opening 12 in the front wall of the container, and these ice cubes can then either fall directly through an outlet opening lh or through a suitable arrangement of a collecting means (not shown) a crusher 15 with conventional rotating crusher arms, which are rotatable together with the distribution means 9, are crushed. The dispenser 5 is arranged inside the freezer compartment 1, the front end with the dispensing opening lh the

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inner panel 16 of the door 2 is adjacent.

The inner panel 16 is formed to have an inwardly extending shoulder 17 which has a horizontal surface 18 which is located immediately below the dispensing opening m when the door is closed. An ice passage 19 having an inlet end in the horizontal surface 18 of the heel and an outlet end extending through the top wall 21 of the recess 4 directs ice from the dispenser into the service room when the dispenser is operating. (

The passage 19 also includes a verse portion 22 between its upper and lower end piece, which normally closes the passage and thus the circulation either of ambient air or air from the freezer compartment through the passage. This shutter 22 is in its open position moved by pressure on a push rod 2 3, which is present in the rear wall of the recess 4, wherein the push rod 23 is connected in a suitable manner by a cable drive means 25 to the closure part. A A switch, which can also be actuated by the push rod 23, is provided to drive the dispenser motor 10, when the push rod is pushed or in the rear pull " device is moved to the closure member 22 to open. In addition to this switch, the controls also include a Crusher control means for dispensing either crushed or cubic ice when the motor 10 is actuated.

The passage 19 has an upper tubular part 28, a hatch part 29 against which the closure part 22 rests, and a lower or outlet portion 30. The lower or outlet portion 30 and hatch portion 29 are through the upper wall 21 of the recess 4 held, while the upper tubular part 28 of the passage in an annular plan 35 which is disposed on the upper surface of the hatch part 29.

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It is desirable that the passage 19 be as short as possible is, so that the ice sections quickly pass through the passage during the operation of the dispensing means 9 and that this passage has a sufficient cross-section to allow the ice cubes to pass without blocking allow.

According to the invention, the means, which is intended for preventing the operation of the dispensing means 9 and thus also the crusher 15 driven by the dispensing means 9, comprises a capacitance sensor electrode or plate 40 which is attached to the passage 19 above the closure 22 and a improved circuit for switching off the motor 10 when the plate ¹ IO detects a change of capacitance from the introduction of an electrically conductive foreign object or body, such as a hand, a toy, a knife handle, or the like, resulting in the passage of the nineteenth

As can be seen from Fig. 2 of the drawing, is the same AC power source (120 volts), which in the illustrated embodiment feeds the dispenser motor 10, through the Switch 39, which can be actuated by the push rod 23, and the coil 41 of a relay switch controlling the motor 42 placed on the connections 44 and 45, which have a voltage-regulating Connect circuit, a series resistor 46, a voltage regulating Zener diode 47 and a rectifier diode 48 includes. The components of the voltage regulating circuit are arranged so that their output terminal 50 is positive and their output terminal 51 is negative.

The control circuit essentially includes a sensor or display circuit 52 and a relaxation oscillator a.

The sensor circuit comprises an anode-controlled silicon rectifier (hereinafter referred to as SCR for short) 55,

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the anode 56 connected to the positive terminal 50 is. Its cathode 57 is connected to the negative terminal 51 through the resistor 58, which thus the outlet terminals 59 and 60 forms. The gate 61 is connected to the positive terminal 50 through the resistor 62.

- circuit
The relaxation oscillator 53 also includes an anode-controlled SCR 63. Its anode 64 is connected to the positive terminal 50 through the resistor 67 and to the negative terminal 51 through a capacitor 65. Its cathode 66 is connected to the negative terminal 51 through the resistor 67 a i and to the positive terminal 50 through the capacitor 68 which are connected via the connections 50 and 51. ■.

The remaining components of the S circuit in FIG. 2 contain a conventional cathode-controlled silicon rectifier 75 which is connected in series with a self-heating thermistor 76 and a relay coil k1 . The gate 77 of the SCR 75 is connected to the output terminal 59 of the measuring sensor circuit. The relay k2 comprises the normally closed contacts 78 and the normally open contacts 79. The sensor electrode or plate k0 is connected to the port 61 of the SCR 55 through a capacitor 86.

During normal operation of the dispenser, the engine will turn off 10 controlled by the switch 39 which can be operated by the rod 23, the closing of the switch 39 to the Motor powered by normally closed contacts 78. ·

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Closing switch 39 also connects terminals 44 and 45 to the AC power source and the combination of Zener diode 47 and series resistor 46 supplies a peak-limited half-sine wave-shaped voltage (dipped half sinusoidal wave voltage) at the terminals 80 and 51 and accordingly also to the sensor and tilting oscillator circuit through the Rectifier diode 48.

The operation of this circuit can best be seen by reference 3 of the drawing, in which the supplied alternating voltage is represented by curve 81 and the DC potential at terminals 80 and 51 by curve 82. In the absence of the relaxation oscillator circuit 53 and without connection to the gate 61 of the anode-controlled SCR 55, anode 56 and port 61, unlike resistor 62, are both positive and essentially on the same Voltage so that the SCR 55 is in its "OFF" state.

The relaxation oscillator circuit 53 is provided, this direct current potential 82 a series of voltage pulses to overlay the one steep leading edge and one size of a few volts.

A typical maximum voltage for waveform 82 in FIG. 1 during the positive half cycle is approximately 10 volts. During this time, the gate of the anode-controlled SCR 63 is at a voltage value of approximately 2/3 of the voltage 82 biased by resistors 70, 71 and 72. The condenser 65 is charged through resistor 67. The anode 64 of the SCR 63 is on the connector between the capacitor 65 and the resistor 67 and follows the approximate wave shape indicated by the curve 84 in FIG is reproduced. When the voltage of the anode 64 reaches a value approximately 0.6 volts greater than the voltage of the Gate 69, the anode-controlled SCR 63 switches on, and this allows the capacitor 65 to pass through the anode 64,

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Discharge cathode 66 of SCR 63 and resistor 67a. Resistance 6? a is on the order of 100 ohms and allows a very fast discharge of the capacitor 65 « This instantaneous discharge of the current through the resistor 67 a leads to a voltage pulse across the resistor 67 a. The capacitor 68 couples this voltage pulse, the has developed at the SCR cathode 66, with the positive supply voltage. The impulse becomes algebraically to the generator supply voltage is added, and this resulting voltage at junction 50 is shown in FIG. 3 by the waveform 85 reproduced. The rectifier diode 48 prevents the Zener diode 47 from cutting off the voltage pulses that lead to the gene- ' rator supply voltage are added. When the discharge current from the capacitor 65 through SCR 63 and resistor 67 a under the Holding current of the SCR drops, the SCR switches off and the capacitor 65 is charged again. This cycle repeats as long as a positive voltage is present at terminal 50.

The resulting voltage at the terminal 85 50 is the necessary source for the operation of the PROBE or display circuit 52, which includes an insulative capacitor 86 and the sensing electrode ¹ IO is connected between the gate 61st The capacitor 86 is a high voltage unit with | a capacitance value on the order of a few hundred picofarads in order to provide electrical isolation from the AC voltage source 81. The dimensions and location of the sensor electrode kO are such that they deliver about 10 picofarads to the detected object.

The voltage 85 powers both the anode 56 and the Gate 6l of the SCR 55 periodically with a pulse with a steep leading edge on the order of a few volts per microsecond Rise time and a size of a few volts.

10 98 51/12 3

- ίο -

If by the approach of a conductive body to the plate 40 a small capacitance of the order of a few picofarads is applied to the gate 6l, a current flows through the resistor 62 and the capacitor with each pulse 86 to charge the applied capacity. This current flow, depending on the rate of rise of the pulse, the The value of the resistor 62 and the capacitance between the plate 40 and the fixed body causes a Loss of voltage occurring at gate 61 with respect to the anode 56 appears negative. When the negative pulse of this voltage When it reaches approximately -0.6 volts, the anode controlled SCR 55 switches "ON" and provides an output voltage between terminals 59 and 60. The output voltage between these terminals provides a signal in Dependence on the presence of a capacitance connected to the gate connection 61.

This output voltage of the sensor circuit is used to control the conventional cathode-controlled SCR 75. The SCR 75 works in the usual way to Coil 41 to be excited.

Whenever the plate 40 has a body capacity in the passage 19 detects, the relay coil 41 is energized, opens the relay contacts 78 and thus turns off the motor 10 and closes the relay contacts 79 and thereby completes a holding circuit for the coil 41 by the closed switch This holding circuit is only interrupted when the switch 39 is reopened, which can only take place when the actuating pressure is removed from the rod 23 and the closure part 22 is closed.

The excitation circuit for the coil preferably comprises 41 also a self-heating thermistor 76 having a negative temperature coefficient of resistance, which a thermal integration or a time delay of some of the supply voltage supplied by the SCR 75

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- ii -

Cycles creates before the coil ¹ M is energized. This prevents the operation of the safety circuit as a result of undesired activation of the SCR 75 by surge voltage pulses or irregular fluctuations in the lines of the AC power source.

Another output arrangement for the probe circuit is shown in Fig. 4 in which resistor 58 replaces is by a parallel connection of a capacitor 83 and a coil 87 of a reed switch 88, which is connected to the Relay coil 41 is connected in series. In this embodiment the invention, the coil 87 is excited by the control of the anode-controlled SCR 55, which the switch closes and thereby energizes the relay coil Ml. In this other Arrangement, the capacitor 83 performs the delay function of the thermistor 76.

It should be noted that the term anode-driven SCR as used with reference to SCR 55 and 63 is intended to encompass its functional equivalent as provided in integrated circuits, namely as a regenerative complementary pair of transistors such as shown in FIG. The transistor 55 a is a PNP type and the transistor 55 b is an NPN type; this pair is controlled by gate pulse through gate 6l a and is connected to the rest of the circuit in the same way as the anode-controlled SCR 55 or the corresponding SCR 63 «. Fig. 5 shows the corresponding connections in connection with the SCR 55. This function is also referred to in the semiconductor industry as "controlled silicon switch ¹¹ ," complementary thyristor "," programmable unijunction transistor fire "and" gate-controlled switch ".

As the above description has shown, when applying an anode-controlled SCR or its functional equivalent in the inventive circuit of the voltage

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voltage pulse not applied to the part of the circuit that contains the output load; this is the circuit comprising the relay coil Hl. Further advantages of the anode-controlled SCR are fast switching with the result of steeper pulse leading edges of greater magnitude than are available with the usual unijunction transistor relaxation oscillators. In this way the entire circuit is more sensitive to control by plate HO.

10 9 8 5 1/12 3 8

Claims (3)

. ■ 2128 2 3G - 13 claims Fridge with a freezer compartment, which has an ice dispenser and a passage for receiving the ice from the issuer and for its transmission in a control room on the outer surface of the cabinet, with working switching means, which include actuating means outside the cabinet, to normal operation of the issuer jsu effect with control means through Inserting an arm or other elongated part into the passage can be actuated to operate the <( To prevent the issuer by the working switching means, characterized in that the control means comprises a capacitance sensor (MO) connected to the passage (19), one .Safety switch and a circuit for actuation of the safety switch by the capacitance sensor, the circuit having a sensor circuit (52) and a relaxation oscillator circuit (53), the sensor circuit being anode-controlled Silicon rectifier (55) comprises to control the supply of energy to the dispenser and means to the anode of the silicon straight line (55) and its gate '. * to be connected through a resistor, as well as means to "the gate of the silicon rectifier (55) with the capacitance Connect s-sensor (40), and the relaxation oscillator circuit a second anode-controlled silicon aligner (63), the cathode of which with A capacitor is connected to a positive pulsating voltage of the anode and the gate of the probe circuit existing silicon rectifier (55) to be supplied, the setting of a body capacitance by the capacitance sensor a gate voltage between the anode and the gate of the silicon alignment device in the sensor circuit (55) and a means which, in the conductive state, of the 109851/1238 - Hi ^ existing silicon rectifier (55) is effective to to operate the safety switch mentioned and thus the operation of the output by the said work switching means to prevent* 2. Refrigerator according to claim 1, characterized in that the safety switch is normally closed and forms part of a relay (42) which comprises a relay coil (Hl) _? whose excitation is controlled by the sensor circuit (5.2). ^ 3. Refrigerator according to claim 1, characterized in that that the energy supply of the sensor (52) and the relaxation oscillator circuit (53) the working switching means is controlled. ^. Refrigerator according to Claim 3, characterized that the Beiais (42) comprises a hold switch. Which delays the disconnection of the coil until the working switching means is open. 109851/1238 Blank page