PT87255B - DEVICE CAUSING THE STOPPING OF AN ELECTRIC MOTOR MOUNTED IN THE MOVEL COVER OF A CONTAINER AT THE TIME OF OPENING OF THE COVER - Google Patents

Description

Description

The present invention relates to an object that causes an electric motor to automatically stop, mounted on the movable lid of a container, when the lid is opened.

The container can be, in particular, but not limited in character, the bowl of a milk cooler, which will be taken here as an example.

Milk coolers of the so-called open type (that is, fitted with a lid) currently manufactured (coolers of the open vertical cylindrical type or open semi-cylindrical type) consist of (see the schematic sectional views of Figures 1 and 2):

- a so-called open tank (1);

- a movable lid (2) connected to the bowl (1) by a hinge (4) with two stable positions:

position 1 (fig. 1): closed vat, position 2 (fig. 2): open vat (the vat is opened manually and is done, namely

- 1 when cleaning by hand or brush inside the bowl),

- an 'agitator' (5) that allows mixing by shaking the milk, which is essential for the homogenization of milk - in order to prevent the rise of fatty substances - and to carry out the necessary convections for a good functioning when the refrigeration unit works (not represented),

- a motor (gearmotor (ó)) that drives the agitator, this gearmotor is mounted on the hinge (4) and is therefore attached to the cover (2).

This motor is driven electrically by an electromechanical or electronic control device, as follows:

- continuous operation when the refrigeration unit operates (0 which is necessary for a good convection that favors thermal exchanges),

- stop at the end of cooling, but with a cyclical operation, in general:

minutes of walking, 13 m of stop or minutes of walking, 28 m of stopping to prevent the cream from rising.

This results in the risk of a potential opening of the lid by an uninformed person who, seeing the stirrer stopped, does not fear automatic reconnection of the stirrer (when the refrigerator group is switched on at the request of the thermostat, or when a stirring cycle is in progress), and could be hurt by the agitator suddenly set in motion.

Against this risk, the possible precautions are as follows:

- the display of a warning next to the lid handle (this provision is mandatory, at least in certain countries: see DIN 8968, § 6.7.a). This display is not a safe way to mitigate this risk.

- Automatic engine stop devices when opening the cover. Two categories can be mentioned here:

a) devices separate from the electrical connection box (7) of the motor (5) ·

There are devices independent of the engine, placed:

- or on the side wall of the tank, near the hinge (4-),

- or on the rim of the bowl (1), starting the engine only when the lid (2) is in the closed position. These devices are generally electromechanical micro-breakers.

They have the following drawbacks:

: need an additional electrical connection, located between the main electrical connection box and the electrical connection box (7) of the engine (5),: present a risk of deterioration or grease, as they are moving parts that may be exposed to shocks and the outside environment.

b) devices located inside the electrical connection box (7) of the motor (5), or attached to it.

~ They therefore do not need an extra connection box, which saves material and assembly labor.

- They are protected by the box (7) against external aggressions (humidity, shocks, etc.).

These devices use the principle of gravity, the electrical connection box (7) not having the same position in relation to the vertical in the case when the tank is closed (fig. 1: position 1) and in the case when the tank is open (fig. 2: position 2).

A device using a glass or plastic capsule containing mercury, mounted in series on the engine supply line, can be envisaged. As mercury conducts electricity, it is easy to design such a capsule horizontally when the tank is closed, provided with two points of contact, then immersed, located at its ends and

- 3 allowing the passage of the current that feeds the motor. When the lid is lifted, one of the two capsule contacts stops

I stay immersed, thus preventing the engine from operating.

This device has the disadvantage of using mercury, which is highly toxic and which is liable to pollute the liquid contained in the vat in case of accidental rupture of the capsule, which would be disastrous when said liquid is food.

To alleviate these drawbacks, the present invention has as its object a device of category b), characterized by being an electromechanical device, fixed in the electrical connection box of the motor, solidary with the box and constituted by a pendulum microswitch, whose electrical contact, mounted in series on the motor's power supply line, is connected to a rotating shaft mounted on the microswitch, horizontally arranged and on which a pendulum attached to the shaft is suspended, with the opening of the container lid as consequence a rotation of said axis in the microswitch under the action of gravity on the pendulum which, in the course of this opening of the cover, moves in relation to the microswitch, causing the rotation of the axis to open the contact that is connected to it, having this contact is expected to be closed when the lid is closed.

A particular embodiment of the device according to the present invention is described below, by way of purely indicative and by no means limiting example, with reference to the attached drawing, the figures of which are depicted

Figs. 1 and 2, a schematic vertical section of a bowl, the lid of which is hinged and closed and open respectively, supports a motor that drives an agitator;

Figs. 3 and 4, schematically, on a larger scale and in vertical section, the electrical connection box of the motor, respectively in the closed and open positions of the cover (positions 1 and 2); and

Fig. 5, the electrical supply scheme of the

device and engine.

In the electrical connection box (7) of the motor (ó), attached to this motor and shown isolated in fig. 3 and 4, a microswitch (6) is placed, whose electrical contact (10) is connected to an axis (β) rotatable mounted on the microswitch, crossing it and arranged horizontally; outside the micro-breaker, a small pendulum (9) is suspended on the axis (8), with which, in solidarity, the pendulum could also be mounted on the axis inside the micro-breaker, the bottom of which should then go through a slit that allows its displacement.

When the lid (2) of the bowl (1) opens by rotation around the hinge (4), the box (7), connected to the motor (5), in turn connected to the lid, moves from position (1) ( fig. 3) in which the contact (10) is closed and allows the motor to be fed, to the position (2) (fig. 4), in which the contact (10) is open, 0 which cuts off the motor supply and consequently the agitator (3) stops. In effect, in the course of the opening movement of the lid that causes the box (7) to rotate around Ijchameira (4), the axis (β) was rotated in the microswitch under the action of the pendulum (9) and in its movement, the contact (10) that opened opened, the closing of the lid (2) takes the box (7) h to position (1) and, by a reverse movement of the axis (8), 0 H contact (10) it is closed again.

The points (R) and (N) represent the power supply terminals of the box (7) and the points (A) and (B) the power supply terminals of the motor (5),

Fig. 5 is the device's power supply scheme in the case of a motor (5) supplied with single phase current (1 x 220 V, for example), The phase (R) and 0 neutral are shown. The electrical connection box (7) is shown in dashed lines. In the pendulum microswitch (6), only the contact (10) is represented; it is in series in the motor supply line (RA) and is shown closed; it will open if the lid is opened. (11) designates a control device 5 -

control (electronic or electromechanical) of the motor operation when the tank is provided with cyclic agitation of its contents.

The present device offers the advantages mentioned above of devices in category b) while eliminating the risk posed by mercury.

Detail modifications in the field of technical equivalences can be introduced in this device without; we therefore depart from the domain of the present invention.

Other possible device applications:

- Stop the agitator in any bowl (other than a milk cooler) provided with a lid attached to the agitator motor.

- Stopping any motor placed on the lid of a machine that can be opened (examples: agitators, mixers, pumps, cutting machines, etc.), setting this motor in motion with an organ mounted under the lid and likely to present a danger to a user of the machine who opened the lid.

Claims (1)

CLAIM - 1 & Device that causes the automatic stop of an electric motor, mounted on the movable lid of a container, at the moment of opening the lid, this device being constituted by a pendulum micro-switch (6), characterized by being fixed in the electrical connection box (7) of the motor (5) »this box being connected to the motor, and the electrical contact (10) of the microswitch mounted in series on the motor power supply line, being connected to a axis (8) mounted rotating on the microswitch, horizontally disposed and on which the pendulum (9) attached to the axis is suspended, with the opening of the lid (2) of the container (1) as a consequence of a rotation of the - 6 said axis (8) in the microswitch (6) under the action of the pendulum's gravity, which causes the contact (10) connected to the axis to open, providing that this contact is closed when the lid is closed.