EP0030631A1

EP0030631A1 - A control apparatus for an electric appliance requiring a programmed connection and disconnection

Info

Publication number: EP0030631A1
Application number: EP80107109A
Authority: EP
Inventors: Emilio Negri
Original assignee: Italora SpA
Current assignee: Italora SpA
Priority date: 1979-12-18
Filing date: 1980-11-17
Publication date: 1981-06-24
Also published as: IT7928172A0; DE3069989D1; IT1126585B; EP0030631B1

Abstract

The apparatus comprises two mechanical, electric or electronic timing devices, each one associated with a switch (6,7) the first of said timing devices (or long time device) having a dial which, divided for instance into 12 or 24 hours, continuously rotates showing with respect to a fixed pointer how much time passes, a knob frictioned on the dial and carrying a pointer and an actuating means (2c) forthe associated switch (6), while the second timing device (or short time device) has a dial (4) divided, for example, into a number of minutes less or equal to 360, which dial is rigidly keyed on the shaft and is provided with an actuating means (4a) for its associated switch (7), a clamping block (8b) being also provided between said first timing device and said second timing device, which is actuated by said first device along with the associated switch (6), the electric appliance to be controlled being series connected with said two switches (6 and 7).

Description

This invention relates to a control apparatus for supplying an electric appliance enabling both the programning of the start and the end of its electric cycle. The apparatus is particularly suitable for programmed switching on and off of stoves, electric plates, etc.
Since years, devices of the above described type have been already comnercially available and known as automatic cook. Such devices are in the form of an electric clock, in which the program is provided on the principle of an ordinary alarm-clock, or more recently in the form of electronic devices provided with visual display and microprocessor logic. However, both such types suffer from same disadvantages, restricting the general use of the device.
Such disadvantages are basically comprised in two classes:

- commplexity of operation in use (from four to six knobs or pushbuttons);
- rather high cost and big dimensions for electric household appliance industry.

These are the reasons why still nowadays the electric ranges and stoves prevailingly use electric switches, in which the end of operation can be programmed, while the start is preset manually
In order to gain wide diffusion, an optimum control apparatus should have the following characteristics:

- capability of programming both the start and the end of operation of the switch with long operating times (from 4 to 12 hours) and short operating tines (from 1 to 360 minutes);
- capability of programming only the end of operation (the start would be coincident with the setting time);
- capability of programning only the start of operation, while the end is provided by manual action;
- manual actuation for both the start and end of the cycle;
- extreme simplicity in program setting so as the user has no problem and can make no error;
- display of the program set during the actuation thereof;
- reduction in costs, especially with respect to the electronic devices having same performances;
- reduced overall sizes in order to give more freedom of design to the household appliance manufacturing industries;
- and, preferably, also the possibility of actuating an acoustic alarm at the end of operation.

The foregoing is the object intended to be attained by the apparatus according to the-present invention.
Said object has been achieved by providing an assembly comprising two mechanical, electric or electronic timing devices, each one associated with a switch, the first of said timing devices (or long time device) having a dial divided, for example, into 12 or 24 hours, which continuously rotates showing with respect to a fixed pointer the time passing, a knob frictioned on the dial and carrying a pointer, and an actuating means for the associated switch, whereas the second timing device (or short time device) has a dial divided for example into a nunber of minutes less or equal to 360, which dial is rigidly keyed on the shaft and provided with an actuating means for its own associated switch, a clamping device being also provided between said first timing device and said second timing device, which is actuated by the first device along with the associated switch, the electric appliance to be controlled being series connected to the two switches, so that by manually rotating the knob of the first timing device, the actuation of the switch associated therewith is effected, and at the same tine the second device is prevented from starting to count its own tines, while through the rotation' of the dial of the second device the actuation is effected for the second device and the end of cycle is programmed; drawing said first device, the knob which had been manually rotated upon presetting so that at rest position of the knob, the first switch is closed and the electric appliance is connected and, at the same time, the second timing device is released, thus enabling the latter to start its tire counting, in addition to the gradual return of the dial of the second device to rest position, under this rest condition the actuation of the second switch and completion of the electric cycle being carried out.
A preferred embodiment of the invention contenplates that the second timing device also actuates an alarm sound.
The invention will now be further described with reference to some exemplary embodiments which are shown in the acconpanying drawings, in which:

Fig. 1 is a front view of an apparatus according to the present invention, as mounted for example on an electric stove;
Fig. 2 is a view similar to that of Fig. 1, but wherein the dials have been rotated to provide the desired presetting;
Figs. 3 and 4 are diagrammatic views of the inner operation of the apparatus according to the present invention at two different operating positions;
Fig. 5 is a sectional view of the apparatus according to the present invention; and
Figs. 6a - 6k are ten electric diagrams for some embodiments.

An unrestrictive enbodiment of the above described device has been outlined in the diagrammatic views of Figs. 1 to 5. In said figures of the drawings, the reference numerals respectively designated:

1 - the dial for the first timing device or long time device designated as a whole at 12;
2 - the setting knob for the device 12 starting the cycle;
3 - the fixed reference pointer for the dial 1 and knob 2;
4- the dial for the second timing device or short tine device designated as a whole at 13;
5 - the fixed reference pointer for the dial 4;
6 - the first switch associated with the first timing device 12 or long time device;
7 - the second switch associated with the second timing device 13 or short time device;
8 - the clamping lever between the first and second timing devices;
9 - the first timing mechanism or long tire mechanism; and
10 - the second timing mechanism or short time mechanism.

The long time timing mechanism 9 is continuously operating: its output shaft in the enbodiment shown makes one revolution every 12 hours.
Its central shaft 9a (Fig. 5) has integrally connected thereto a bushing 9b and a clutch 9c driving said dial 1. The latter . has a groove la for resetting the time in dial 1 in case of lack of supply to the motor, and to this end the above mentioned clutch 9c is provided. The knob 2 having a mark 2a is connected on said dial 1 by means of a clutch 2b. This knob 2 also has a profiled notch 2c (Fig. 2), in which the clamping lever 8 engages when the mechanism is at rest condition. Under this condition, said lever with its projection 8a leaves the switch 6 at free condition, which switch remains closed and at the same time the lever 8 does not contact the dial 4 with its clamping block 8b.
The short time timing mechanism 10 is actualy a minute indicator and is stationary at rest condition. This mechanism wears keyed rigidly on the shaft 10a (Fig. 5) the dial 4, the latter having a cam profiled portion 4a (Fig. 3) and a "manual" mark (Fig 1 and 2), at which the dial 4 remains clamped in not shown known manner at a position in which the associated switch 7 connects the electric appliance 11. Under rest condition, said cam 4a acts upon said switch 7 maintaining it at open condition.
The above described situation is electrically shown in the diagrams 6a and 6b which exclusively differ in the timing mechanism 10 which in the former case is of mechanical type and in the latter case of electric type; reference numeral 11 designates the electric appliance (electric resistance, motor, etc.).
In order to describe the behaviour of the device, resort is made to an exemplary use.
Assume that it is 10 a.m. (as shown in Fig. 2) and the stove is to be switched on at 6 p.m. and maintained switched on until 7.30 p.m.
Ihe operations to be carried out are only two:

- Clockwise rotation of knob 2 until mark 2a is placed at 6 o'clock;
- Clockwise rotation of dial 4 until the 90th minute is placed at the fixed pointer 5.

Under these conditions, the switches 6 and 7 are at open and closed positions, respectively, as shown in the diagrams of Figs. 6c and 6d, since the notch 2c has moved from the initial position displacing the lever 8 which with its projection 8a acts on switch 6 and with its block 8b clamps the knob 4, preventing the short time mechanism from operating; at the same time, the cam profiled portion 4a is displaced and accordingly the switch 7 is closed.
As a result, the electric appliance 11 is no longer supplied, as well. as the timing mechanism 10 (should the latter have an electric motor).
As time is elapsed, the conditions do not change until the knob 2, counterclockwise driven by knob 1 through clutch 9c, is reset to zero position.
Now the lever 8, as urged by spring 8c, falls down in the notch 2c, releasing the switch 6 which closes and at the same titre also said dial 4, since the sliding block 8b is displaced.
It should be noted that up to now the user can always see how the program has been set, because the mutual position of knob 2 and dial 1 has never changed and dial 4 has not been displaced.
Under the new situation (diagrams 6e and 6f), the electric appliance 11 and timing mechanism 10 (if the latter is of electric type) remain supplied with current, and accordingly the connection is started. This condition is maintained until the dial 4 driven by the timing mechanism 10 through the shaft 10a is reset to zero opening the switch 7 through said cam 4a. Also at this step, the user can visualize,by means of dial 4, how the cycle proceeds.
It should be noted that when desiring only short time settings during which the current supply begins at the moment of time setting, this is obtained by acting exclusively on dial 4.
Where very long supply times should be required with program start at the moment of manual setting, the electric diagram will be modified as shown in the diagrams 6h to 6k. In these diagrams, the switches 6 and 7 have been replaced by switchover devices 61 and 71.
Fig. 6h shows the rest condition.
Fig. 6i shows the electric applicance connection and disconnection for long times without any programming of cycle start. In this case, one only acts on knob 2, maintaining the short time timing mechanism stationary.
When desiring to set also a short time of operation with cycle start at the moment of manual operation, only the dial for the short tine timing device is displaced, as shown in Fig. 6j.
Finally, when desiring to operate an electric applicance for a programmed time, one acts on both knob 2 and dial 4 of the second timing device, so as to preset the desired program, as shown in Fig. 6k.
A further performance is provided by the device positioning the dial 4 with the "manual" mark at the fixed reference pointer 5. Under this condition, the mechanism 10 is prevented from moving due to an inner stop and accordingly is retained at the indicated position until it is manually reset to zero or at a time ranging between 1 and 120 minutes. The above described condition contemplates the same behaviour of the switch as those described in the previously examined diagrams and allows a continuous operation of the electric appliance in the interval between two manual cperations when acting only on the dial 4, and a programmed operation of the beginning if the knob 2 is set.
This invention comprises all of those variants that may be apparent to those skilled in the art. Particularly, by reversing the conditions of the switches, instead of controlling periods of current supply, periods of current supply suspension can be controlled. Moreover, the position of the dials and fixed pointers can be reversed.
Finally, the timing devices 9 and 10 can be combined in a single device in order to provide a single electric motor, having two units of reduction gearings, which will then drive the respective two output shafts 9a and 10a.

Claims

1. A control apparatus for an electric appliance requiring a programmed connection and disconnection, characterized by comprising two mechanical, electric or electronic timing devices (12 and 13), each of which associated with a switch (6, 7), the first (12) of said devices (or long time device) having a dial (1) which, divided for example into 12 or 24 hours, continuously rotates indicating with respect to a fixed pinter (3) how much time passes, a knob (2) frictioned on the dial and carrying a pointer (2a), while the second timing device (13) (or short tine device) has a dial (4) divided, for example, into a number of minutes less or equal to 360 minutes, which dial is rigidly keyed on the shaft (10a) and provided with an actuating means (4a) for its own associated switch (7), a clamping block (8b) being also provided between said first timing device (12) and said second timing device (13), which is actuated by said first device (12) along with the associated switch (6), the electric appliance (11) to be controlled being series connected to said two switches (6,7), so that by manually rotating the knob (2) of said first timing device (12), the switch (6) therewith associated is actuated, and at the same time the second device (13) is prevented from starting its counting, while by rotating the dial (4) of the second device (13), the second switch (7) is actuated and the end of cycle is programmed; driving said frist device (12) the knob (2) which had been manually rotated during presetting so that at rest position of said knob (2) the first switch (6) is closed and thus the electric appliance (11) is connected, and at the same time the second timing device (13) is released, thus enabling the same to start its own tire counting in addition to the gradual return to rest position for the dial (4) of the second device (13), under this rest condition the actuation of the second switch (7) and conpletion of electric cycle being carried out.

2. An apparatus according to Claim 1, characterized in that said second timing device (13) also controls an acoustic alarm at the cycle end.

3. An apparatus according to Claim 1 or Claim 2, characterized in that at least one of said timing devices (12, 13) is mechanical.

4. An apparatus according to Claim 1 or Claim 2, characterized in that at least one of said timing devices (12, 13) is electric or electronic.

5. An apparatus according to any of Claims 1 to 4, characterized in that the dial (1) of the first device (12) is frictionally mounted on the drive shaft (9a), and said dial (1) is provided with an actuating means (la), so that the time indicated thereon can be possibly adjusted.

6. An apparatus according to Claim 1 or Claim 2, characterized in that the switches (61 and 71) are changeover switches.

7. An apparatus according to Claims 2, 3, 4 and 5, characterized in that said alarm is of mechanical type.

8. An apparatus according to any of Claims 1 to 7, characterized in that a "Manual" mark is also provided on the dial (4) of the second timing device (13) at a position in which the timing mechanism (10) is blocked and the associated switch (7) is actuated to allow the operation of the electric appliance (11).

9. An apparatus according to any of Claims 1 to 8, characterized in that the mutual position of said dials (1, 4) and fixed pointers (3, 5) is reversed.

10. An apparatus according to Claims 1 to 9, characterized in that the motors for the two timing mechanisms (9, 10) are combined in a single motor controlling both of the reduction gearings for the speed of rotation.