FR3106510A1 - High voltage electrostatic fiber flocking device - Google Patents

Abstract

The invention relates to an apparatus for flocking AFE fibers, electrostatic and high voltage. Said device comprising an IUT user switch, said AFE device comprising on the one hand a RES reservoir capable of accommodating fibers, on the other hand a main body COP capable of accommodating high voltage and low voltage electrical means, and of cooperating with a MAS earth cable, said AFE device also comprising a rotation coupling means constituted by a rotating ETA coupling star, integral with said RES reservoir, said RES reservoir and main body COP can be separated or coupled.

Description

Apparatus for flocking high voltage electrostatic fibers.

The present invention relates to an electrostatic flocking apparatus, particularly suitable for flocking high voltage fibers.

We know this type of device which is in the form of a reservoir of fibers intended to equip a previously glued surface, provided on the one hand with a sieve cover, on the other hand with an electrode arranged at the bottom of the reservoir. The device also includes a battery and a HT generator connected to the electrode, as well as a ground cable connected to the glued surface.

The generator generates a high voltage at the electrode, after pressing a contactor button, the fibers will then stand up on the glued surface.

This type of device has disadvantages:

When changing fibers, the tank must be cleaned with compressed air, which is inconvenient and laborious.

If a finger is in contact with the electrode, or inside the tank, there is a great risk of taking an electric shock.

The main object of the present invention is therefore to overcome these various drawbacks by proposing an apparatus for the electrostatic flocking of high voltage fibers.

According to a major feature of the invention, the device comprises a user switch. The apparatus comprising on the one hand a reservoir capable of housing fibers, on the other hand a main body capable of accommodating high voltage and low voltage electrical means, and of cooperating with a ground cable, the apparatus comprising also a means of coupling by rotation consisting of a rotary coupling star, integral with the tank, the tank and the main body can be separated or coupled.

According to another characteristic of the invention, the star being able to actuate, during the uncoupling of the tank and the body, a first safety means, consisting of a low voltage switch control rod cooperating with a safety switch low voltage, then the low voltage supply is turned off, and vice versa is allowed when mating.

According to another characteristic of the invention, the star being able to actuate, during the uncoupling of the tank and the body, a second safety means consisting of a high voltage discharge control rod cooperating with a high voltage discharge switch , the high voltage electrical means comprising capacitors, the discharge of the capacitors is then carried out, the low voltage supply is then deactivated, and vice versa is authorized during coupling.

According to another characteristic of the invention, the capacitors being arranged in cascade, the second safety means is reinforced during the discharge.

According to another characteristic of the invention, the tank being equipped on the one hand at its surface with a lid grid, on the other hand at its bottom with an electrode consisting of a conductive plate, and supplied with high voltage by the high-voltage electrical means via said star, the electrode being laterally insulated by a material having suitable dielectric strength, it cannot generate an arc when said tank is earthed.

According to another characteristic of the invention, the distance between the grid and the electrode always being greater than the distance at which an electric arc strikes, the electrode cannot generate an arc during grounding. .

According to another characteristic of the invention, the grid being able to be opened by rotation during a fiber refill of the tank, a third safety means consists of a ring associated with the grid and provided with lugs passing through the bottom of the tank by lights external to the electrode, which allow during opening to activate the first and second safety means, and vice versa during closing.

According to another characteristic of the invention, a device for detecting the intrusion of external objects being associated with the gate, it is connected to an alarm means as well as to the first and second means.

These characteristics make it possible to overcome, point by point, the various drawbacks listed above.

Other advantages and characteristics will emerge better from the following description of a non-exclusive embodiment of a device in accordance with the invention, given by way of non-limiting example with reference to the appended drawings:

There represents the invention in section,

There represents a main body object of the invention in section,

There shows a tank object of the invention in section.

With reference to the figures, the object of the invention relates to an apparatus for flocking AFE fibers, electrostatic at high voltage.

Said device comprises a user switch IUT actuated at the start and at the end of use.

Said AFE device comprises on the one hand a tank RES able to house fibers, on the other hand a main body COP able to house high voltage and low voltage electrical means, and to cooperate with a ground cable MAS.

Said AFE device also comprises a means of coupling by rotation constituted by a rotating coupling star ETA, integral with said tank RES, said tank RES and main body COP can be separated or coupled.

Electronic current detection systems are too slow to trigger and the capacitors are always charged anyway.

It is therefore necessary to have two means of safety: The first means consists in ensuring that as soon as a tank is being removed, the low voltage supply of the electronics must be deactivated, then, a second means consists, as soon as the low voltage supply is deactivated, in triggering the discharge of the capacitors.

These two actions are generated by the uncoupling movement of the tank from the body of the device.

The first step is to turn off the low voltage power supply to the electronics. As the coupling is located in the high voltage region, it is not possible to bring a switch to this level without significant risk of arcing with the low voltage. Even an “optical coupling” system would require low voltage power and pose a risk of arc flash. This is the reason why the device consists of a rod made of an insulating material which will push a switch located in the low voltage region and open the power supply of the electronics.

Similarly, the second stage of discharging the capacitors is also difficult because the only known method consists in connecting the low voltage ground to the last high voltage stage in order to empty the capacitors. The voltage levels reached will cause an electric arc. The use of a switch is not possible.

The second means found consists of a series resistor assembly where each level reduces the voltage to an acceptable level after insulation in the resin going up towards the voltage trap region. The termination of these resistors is connected to a switch whose other pole is connected to ground. The switch and the contacts are housed in an airtight box and itself cast in resin to avoid any risk of producing a spark in the open air.

Just as the power supply is controlled by a rod, the discharge switch is controlled by an insulating rod to connect the movement of the HV part of the device and the LV part where the switch is located.

Consequently, said star wheel ETA is able to actuate, during the uncoupling of said tank TRS and said body COP, a first safety means, consisting of a low voltage switch control rod TBT cooperating with a low voltage safety switch IBT .

The low voltage supply is then deactivated, and vice versa is allowed when mating.

Said star ETA is also able to actuate, during the uncoupling of said reservoir RES and said body COP, a second safety means consisting of a high voltage discharge control rod THT cooperating with a high voltage discharge switch IHT.

Said high voltage electrical means comprise capacitors CDS1, CDS2, the discharge of said capacitors CDS1, CDS2 is then carried out, the low voltage supply is then deactivated, and vice versa is authorized during coupling.

Said capacitors CDS1, CDS2, are arranged in cascade, the second safety means is thereby reinforced during discharge.

In order to prevent the user from taking high voltage discharges of the order of 10 to 100 kilovolts, in the context of consumer appliances according to the standards in force, and in order to avoid the risk of sparks in flammable environments , said AFE device incorporates a cascade of capacitors associated with a diode, which constitutes a Graetz bridge.

Said tank RES is equipped on the one hand on its surface with a cover grid GRI, on the other hand on its bottom with an electrode ELE consisting of a conductive plate, and supplied with high voltage by said high voltage electrical means via said ETA star.

Said ELE electrode being laterally insulated by a material having a suitable dielectric strength, such as "ABS" with a dielectric strength of 20 kilovolts per millimeter, or such as "HDPE" with a dielectric strength of 30 kilovolts per millimeter, it cannot generate arc during a grounding of said tank RES.

The distance between said grid GRI and said electrode ELE always being greater than the initiation distance of an electric arc. Said ELE electrode cannot generate an arc when grounded

Furthermore, the opening of said grid GRI during fiber recharging must cut off the low voltage supply of said AFE device and discharge said capacitors CDS1, CDS2 in order to prevent a person from approaching his fingers directly or indirectly from electrode still charged.

A third safety means associated with said grid GRI consists of a ring provided with lugs at the base and crossing the bottom of said tank RES by ports LUM1, LUM2 fitted outside of said electrode ELE.

When closing said RES tank by screwing said GRI grid, the latter pushes on the ring provided with lugs which itself pushes on the locking system of the coupling ring and initially unlocks the supply and then discharge said capacitors CDS1, CDS2.

Said grid GRI can be opened by rotation during a fiber refill of said reservoir RES. A third safety means consists of a ring associated with said grid GRI and provided with lugs passing through the bottom of said tank RES by lights LUM1, LUM2 external to said electrode ELE, which allow when opening to activate the first and the second safety means, and vice versa when closing.

An external object intrusion detection device, not shown, is associated with said GRI grid. It is connected to an alarm means as well as to the first and second security means.

The device is also fitted with a device for measuring the current in the event of inadvertent short-circuiting: contact by a wire connecting the ground to the electrode, or contact between the ground and a part of the human body.

It is quite obvious that the examples of the embodiments which have just been given are only particular illustrations and in no way limiting with respect to the fields of application of the invention.

Claims (8)

Apparatus for flocking AFE fibers, electrostatic and at high voltage, characterized in that, said apparatus comprising a user switch IUT, said AFE apparatus comprising on the one hand a reservoir RES able to accommodate fibers, on the other hand a main body COP able to house high voltage and low voltage electrical means, and to cooperate with a ground cable MAS, said AFE device also comprising a means of coupling by rotation constituted by a rotating coupling star ETA, integral with said tank RES, said RES tank and COP main body can be separated or coupled AFE device, according to claim 1, characterized in that said star wheel ETA being able to actuate, during the uncoupling of said reservoir TRS and of said body COP, a first safety means, consisting of a low voltage switch control rod TBT cooperating with an IBT low voltage safety switch, the low voltage supply is then deactivated, and vice versa is allowed when mating. AFE apparatus, according to any one of claims 1 and 2, characterized in that said star wheel ETA being capable of actuating, when said tank RES and said body COP are uncoupled, a second safety means consisting of a high voltage discharge THT cooperating with a high voltage discharge switch IHT, said high voltage electrical means comprising capacitors CDS1, CDS2, the discharge of said capacitors CDS1, CDS2 is then carried out, the low voltage supply is then deactivated, and vice versa is allowed during mating. AFE apparatus according to Claim 3, characterized in that the said capacitors CDS1, CDS2, being arranged in cascade, the second safety means is reinforced during the discharge. AFE apparatus according to one of the preceding claims, characterized in that, said reservoir RES being equipped on the one hand at its surface with a cover grid GRI, on the other hand at its bottom with an electrode ELE consisting of a conductive plate, and supplied with high voltage by said high voltage electrical means via said star ETA, said electrode ELE being laterally insulated by a material having an appropriate dielectric strength, it cannot generate an arc when grounded of said reservoir RES. AFE apparatus according to Claim 5, characterized in that the distance between the said grid GRI and the said electrode ELE being always greater than the distance at which an electric arc strikes, the said electrode cannot generate an arc during a start-up. the mass. AFE apparatus according to Claims 2 and 3, taken in combination with one of Claims 5 to 6, characterized in that, the said GRI grid being able to be opened by rotation during a fiber refill of the said reservoir RES, a third means of safety consists of a ring associated with said grid GRI and provided with lugs passing through the bottom of said tank RES by lights LUM1, LUM2 external to said electrode ELE, which allow during opening to activate the first and second safety means , and vice versa when closing. AFE apparatus according to Claims 2 and 3, taken in combination with one of Claims 5 to 7, characterized in that a device for detecting the intrusion of external objects being associated with the said GRI grid, it is connected to a alarm means as well as to the first and second means.