CH641962A5 - ACTINIC AND ULTRASONIC CLEANING AND AIDING PROCESS AND DEVICE. - Google Patents

Description

The present invention is in the field of cleaning small instruments, such as those for surgery, dentistry, laboratory,

kitchen, etc., which require, between two uses, careful cleaning and, sometimes even, sterilization.

Recently, cleaning methods and devices using ultrasonic vibration have been known; these devices are constituted, in general, by a tank on the bottom or the walls of which is applied an ultrasonic generator such as piezoelectric quartz or magnetostriction. The objects to be cleaned are placed in the tank containing a liquid which can be, as the case may be, water added with a detergent or an organic solvent. It is known that ultrasonic vibrations generate on the microscopic scale within the liquid areas of compression and depression which mechanically stress, on the microscopic scale of course, but in a violent manner, the objects contained in the liquid. This phenomenon is known as cavitation. Foreign bodies present on the surfaces to be cleaned are then torn off and dispersed in the liquid.

In the case of tools for medical or scientific use, the objects thus cleaned are often subjected to sanitization either by passage through an oven or an oven, or by soaking in a sanitizing liquid, or by exposure, in an enclosure, to radiation. such as ultraviolet rays.

The asepticization operation following ultrasonic cleaning, unless it is in the sterilization by steaming mode,

may not always be effective; thus, if the cleaned objects contain cavities, the stains present in the liquid following the action of ultrasound will be housed in these cavities where they will be sheltered from the bactericidal action of ultraviolet rays or of the chemical agent used to sanitization.

Another drawback of the above-described procedure lies in the successive manipulations of the objects to make them undergo the various cleaning and asepticization operations.

The object of the present invention is to propose a method and a device enabling the practitioner to have clean and sanitized tools, the practitioner's operations being limited to depositing the tools in such a device, starting a cleaning program and remove it when needed and after the cleaning program has been run.

The method according to the invention consists in producing in the liquid, in which the objects to be cleaned are bathed, an ultrasonic agitation and, simultaneously, in irradiating the liquid by means of actinic light, for example ultraviolet rays.

It follows from this way of making that the particles of contamination contaminated by bacteria are torn from their protective support, which constitute the cavities of the objects to be cleaned, to be dispersed in the liquid where they are exposed to actinic radiation and, as a result , destroyed.

Advantageously, the objects to be cleaned are kept constantly exposed to actinic radiation after the liquid has been removed, until they are used.

It should be understood that the simultaneous action of ultrasound and ultraviolet rays is not equivalent to their successive use; in fact, the microscopic agitation of the liquid leads, after a certain time, to macroscopic agitation which has the effect of bringing the bacteria extracted by the microscopic agitations into the ultraviolet irradiation field; thus, in its result, the action of ultraviolet could be equivalent to the agitation of a liquid having by itself a bactericidal effect; but we also know that bactericidal chemical agents, such as chlorine or chlorinated products, can have a harmful action on the surfaces of these small medical or scientific tools.

The present invention also relates to a device for implementing the method described above. This device is defined by claim 2.

According to one embodiment of the device, the actinic radiation source is located under a cover forming a reflector arranged above the tank.

According to another embodiment, the device comprises a means for heating the liquid which can advantageously be a

5

! 0

15

20

25

30

35

40

45

50

55

60

65

3

641,962

resistance bonded to the tank by means of a silicone elastomer and, preferably, on an external face of the tank.

According to another embodiment, the device comprises means for filling the tank with liquid, means for establishing therein, said tank being full, a macroscopic circulation of the liquid, and means for emptying said tank of its liquid.

According to another embodiment, the device of the invention comprises means for introducing ambient air under the cover of the tank in the vicinity of the actinic radiation source, the air introduced being intended for drying the cleaned objects and being itself subjected to the sanitizing action of radiation.

According to another embodiment of the invention, the device comprises programming means intended to control the following operations, after switching on the device, closing the cover and manual control of the start of the cycle:

- activation of the filling means, the heating means, the radiation source and the ambient air fan, and the cooling fan,

- after a determined period dl, inhibition of the filling means and, simultaneously, activation of the ultrasound generator,

- after a determined period d2, inhibition of the ultrasonic generator, activation of the emptying means,

- after a determined period d3, inhibition of the emptying means and inhibition of the cooling fan,

- After a determined period d4 consecutive to the inhibition of said emptying means, inhibition of the radiation source and of the ambient air fan, the system then returning to its initial state.

The source of radiation and the ambient air fan can advantageously be reactivated for a new determined period d4 by closing the cover and be inhibited by opening the latter; it results from this provision, on the one hand, security with regard to the risks of electrocution linked to the relatively high voltage present in the radiation source when it is activated and, on the other hand, a sterilization period air following the introduction of non-sterile ambient air following the opening of the cover.

The present invention will be better understood, details will appear and variant embodiments will be given in the description which will be made of it in relation to the figures of the appended plates in which:

fig. 1 is a schematic representation of a device of the invention comprising all of the means for ensuring its automatic operation,

fig. 2 is a function / time diagram,

fig. 3 is a cutaway cutaway representation of an alternative embodiment of the device of the invention, and FIG. 4 is a schematic illustration of a variant of the filling and emptying mode.

In fig. 1, a device of the invention consists mainly of a metal tank 1 and a cover 2 hinged on an edge 3 of the tank. Under the cover 2, forming a reflector, the curvature of which can be cylindrical or parabolic, or of any other shape allowing the concentration of the radiation in the underlying vessel, is located a ramp 4 with ultraviolet rays constituting the actinic light source. In the vicinity of the ramp 4, an orifice 5 made in the reflector allows the introduction, by means of a fan 6 and in the direction of the ramp 4, of a current of ambient air which will be evacuated through the gap between the tank and the cover.

In the tank 1, a basket 7 is suspended within the liquid 8 which can be natural, distilled or demineralized water; objects such as symbolized in 9 and intended to be cleaned are placed in the basket.

On the external face of the bottom of the tank is added the ultrasonic generator which consists of an aluminum plate 10 glued against the bottom of the tank and intended to protect the piezoelectric crystal and to adapt its frequency to the frequency of resonance of the tank, of a washer 11 of a thermal insulator, for example Celoron®,

bonded to the plate 10, and transducer 12 bonded to the washer 11 and constituted by a piezoelectric quartz and its electrodes; advantageously, the adhesive used for these bondings is a cyano-acrylic adhesive.

On the outer face of a wall of the tank is attached, by bonding by means of a silicone elastomer, a heating resistor 13 intended to heat the liquid through the walls of the tank; the resistor 13 is under the control of a regulator 131 which takes its start-stop information 132 from a sensor suitably located on the tank in the vicinity of the resistor 13.

The filling, circulation and emptying means comprise a tabular circuit 14 opening, on the one hand, at a low point 15 of the tank and, on the other hand, at a point 16 located on a side wall in the vicinity of the bottom ; on the circuit is mounted a pump 17 mainly intended to circulate the liquid in the tank; the pump 17 is of the positive type, that is to say that it does not admit, when stopped, the passage of the liquid; upstream of the pump, a first tap 18 has been made on the circuit 14 which, through a first solenoid valve 19, leads to a sewer 20. Advantageously, the tap 18 is located in a vertical position below the circuit 14, of so as to allow the fall by gravity and the trapping of dense dirt entrained in the circuit; according to an alternative embodiment not shown, this nozzle 18 is shaped as a cyclone, so as to accentuate the phenomenon of trapping by gravity. Downstream of the pump, a second tap 21 leads, through a second solenoid valve 22, to a reserve of liquid 23. An overflow pipe 24 opening in the vicinity of the upper edge of the tank is connected to the sewer pipe in downstream of the solenoid valve 19. The device also includes an oscillator 28 whose function is to produce an oscillating electrical voltage of frequency capable of causing the transducer 12 to vibrate; it further comprises a fan 29 intended to cool, by pulsed air taken from the outside, the power members such, for example, as the transducer and the oscillator; the circuit also includes a detector, such as an ILS microswitch, in the open (circuit closure) or closed position of the cover 2.

The automatic operation of a device of the invention, as will now be described, is ensured by a programmer 26 which is preferably of the type with integrated logic circuits operating in sequential mode from a base time which can be either a crystal oscillator or any other regular frequency source such as, for example, the mains frequency; the programmer could also be of the electromechanical type but with, as a disadvantage, less flexibility of adjustment.

The programmer 26 acts on the operating organs of the device, such as motor, resistor, oscillator, electromagnet, etc., by means of a power stage 27 consisting, for example, of electromagnetic microrelays. The programmer 26 as well as the power stage 27 receive the energy necessary for their operation, in the form of an appropriate electrical voltage, from a supply box 25 which is itself connected to the mains by a general switch 30 .

The lines shown in dashes in fig. 1 represent the electrical links, either control or power, between the programmer, the power stage and the various operating members; the voltage state of these lines is of the binary type and is said to be either activated (energized) or inhibited (deactivated).

There is shown in the diagram of FIG. 2, the states of each of the lines in FIG. 1, taken as the operating cycle progresses; on this diagram, manual interventions, or even independent of the operating cycle, are represented by arrows in dashed lines with the letter M.

We can now follow the progress of an operating cycle by referring to Figs. 1 and 2. The first operation, the tank being supposed to contain objects to be cleaned and the cover being closed, consists in putting the device under tension by means of the switch 30, then in initiating the cycle by pressing on a push-button 31; the appearance of a tension at the edge of the pusher 31 causes si5

10

15

20

25

30

35

40

45

50

55

60

65

641,962

4

simultaneously the passage in the activated state of lines 33 and 37, that is to say that the solenoid valve 22 is open, which allows the passage of the liquid 23 from the reserve into the tank and that the ramp 4 is on and the fan 6 switched on; the passage of the line to the activated state triggers a counting of predetermined duration dl; this duration corresponds to the estimated duration of filling of the tank 1; the end of this counting causes the return of line 33 to the inhibited state and, therefore, the closing of the solenoid valve 22 and, simultaneously, switches lines 34 and 35 to the activated state; the passage to the activated state of line 34 has the effect of heating the resistor 13; the passage to the activated state of line 35 has the effect of simultaneously starting the pump 17, the oscillator 28 and the fan 29; the passage of line 35 to the activated state also has the effect of triggering a second counting of predetermined duration d2; the end of this counting simultaneously causes the return of line 34 and 35 to the inhibited state and the passage of line 36 to the activated state; the predetermined duration d2 is the estimated duration necessary for cleaning and asepti-sation of the objects by the combined action of ultrasonic waves and ultraviolet rays. The passage of line 36 to the activated state triggers a third counting of predetermined duration d3, the term of which fixes the return of line 36 to the inhibited state; the activated state of line 36 corresponds to the opening of the solenoid valve 19 and the duration d3 is that estimated necessary for the emptying of the tank. The passage to the inhibited state of line 36 also has the effect of triggering a fourth compage of predetermined duration d4 the term of which causes the return to the inhibited state of line 37, that is to say causes the emission stop of the ramp 4 and stop of the fan 6. At this last stage, the objects are in principle dry and sanitized, if they have been suitably arranged, and are surrounded by an air itself sanitized; maintaining operation for the duration of the ramp d4, following the emptying of the tank, allowed the air which replaced the liquid in the tank to undergo sterilization by ultraviolet rays.

It is planned that, if the cover comes to be lifted, for example to allow the removal of an object from the tank (passage of line 32 in the activated state), the closing of the cover (return of line 32 to the inhibited state) returns line 37 to the activated state for a new duration d4. The tank will only be filled again for a new operating cycle after a new impulse given to the push button 31.

In fig. 3, there is shown a device of the invention in one of its particular embodiments, the representation being incomplete with regard to the operating members, and being broken away with regard to the carcass and fermenting elements; the elements of this figure which are found in the schematic representation of FIG. 1 are shown with the same references. Thus, the reflector 2 is embedded in a cover housing 40; the reflector is pierced with a plurality of orifices 5 located in the vicinity of the ramp 4 and, preferably, just above it; in the space between 5 the cover box and the reflector is the fan 6 which takes air outside and forces its passage through the orifices 5.

The tank 1 comprises, glued to the outer face of its base, the aluminum washer 10 on which the transducer 10 12 is itself glued. The tank 1 is supported by a cover box 41 itself supported by a base 42; in the space between the tank, the cover box and the base are placed the various operating and control members such as, as shown in the figure, the cooling fan 29 and the pump 17. Avan-15 taggingly, the base, the cover housing and the tank housing are made of polyester resin reinforced with glass fibers.

In another embodiment not shown in the figures, the cover and its cover housing are supported in the manner of a jib arm by a tubular mast planted in one of the side edges of the tank housing; the mast can simultaneously slide vertically in its housing and rotate around its axis. The vertical movement of the mast can be advantageously assisted by a counterweight or a spring. In this embodiment, the control members and the power stage are housed in the cover housing, the mast also serving as a sheath, both for the passage of power lines and for the passage of air. from the tank housing to the cover housing, then in the vicinity of the ramp.

In fig. 4, a device 50 of the invention of any type 30 is provided with a particular liquid circuit, in particular intended to ensure the filling of the tank from a tank 51 located under a benchtop 56 and to ensure its emptying in another tank 52 also located under the bench 56. Such an arrangement will be useful when, the cleaning liquid being of a certain price, such as alcohol, organic solvent, etc., it is desired to recover it by view of its recycling after treatment. According to this arrangement, the solenoid valves of FIG. 1 are replaced respectively by positive pumps 53 and 54, while a pump 55 has the same situation and plays the same role as the pump 17 of FIG. 1; of course, in this dis-40 position, they cannot have, any more than the pump and the solenoid valves of fig. 1, simultaneous active state; it should also be understood that the suction and discharge height of the pump 54 will be sufficient to ensure the rise of the liquid from the reserve 51 to the tank.

20

R

3 sheets of drawings

Claims (9)

641,962 1. Method for cleaning and sanitizing objects, such as surgical, scientific or culinary utensils, placed in a tank containing a cleaning liquid, characterized in that ultrasonic agitation is produced in the liquid and that, simultaneously, it is irradiated with actinic light. 2. Device for implementing the method according to claim 1, characterized in that it comprises, in order to act in combination: - a tank (1) intended to contain a liquid, Means (10, 11, 12), called ultrasonic generators, for producing in the liquid of the tank an ultrasonic agitation, Means (4), known as actinic radiation source, acting simultaneously with ultrasonic agitation to irradiate said liquid, and - Means (7) for supporting, within said liquid, said objects to be cleaned. 2 3. Device according to claim 2, characterized in that it further comprises a means (13) for heating the liquid. 4. Device according to claim 3, characterized in that said heating means is a resistance bonded to the tank by means of a silicone elastomer. 5. Device according to claim 2, characterized in that it further comprises means (14,15,16) for filling said tank with liquid, means (17) for establishing therein, said tank being full, a macroscopic circulation of the liquid, and means (18, 19, 20) for emptying said tank of its liquid. 6. Device according to claim 2, characterized in that it further comprises means (5, 6) for introducing ambient air under a cover (2), in the vicinity of said source (4), l ambient air being intended for drying the cleaned objects and being itself subjected to the sanitizing action of the radiation. 7. Device according to claim 2, characterized in that said source (4) of actinic radiation consists of a lamp with ultraviolet rays. 8. Device according to all of claims 2 to 7 comprising, in addition, programming means (26), intended to control a cycle of operations, characterized in that said cycle comprises the following operations: Activation of the filling means (14, 15, 16), the heating means (13), the radiation source (4) and the ambient air fan (6), and the cooling fan (29), - after a first determined duration, inhibition of the filling means (14, 15, 16) and, simultaneously, activation of the ultrasound generator (10, 11, 12), - after a second determined duration, inhibition of the ultrasound generator (10,11,12), activation of the emptying means (18, 19,20), - after a third determined duration, inhibition of the draining means (18, 19, 20), and inhibition of the cooling fan (29), - after a fourth determined period consecutive to the inhibition of said emptying means (18, 19, 20), inhibition of the source (4) of radiation and of the ventilator (6) of ambient air, the system then returning to its initial state . 9. Device according to claim 2, characterized in that said generator (10,11,12) of ultrasound comprises an aluminum plate (10) glued against the bottom of the tank (1), a washer (11) d 'a thermal insulator glued against the plate (10) and a piezoelectric quartz (12) glued against the washer (11).