Filter cleaning in a vacuum having a flap element

The invention relates to filter cleaning in a vacuum having a switchable flap element, the cleaning of the filter or of parts of the filter being carried out by supplying a secondary air flow to the interior of the filter to be cleaned, and air being able to flow through the filters separately from each other from the outside to the inside in the vacuum container in a sealed manner, and a flap element disposed in a chamber housing being pivotable, by means of the pivoting of which openings may be closed and released, the secondary air flow reaching the surface of the filter to be cleaned from the inside toward the outside in pulses, characterized in that the flap element comprises at least two partial flaps, the pivoting of which is actuated by a pivot drive, the respective partial flap optionally closes the outflow opening of the respective filter chamber in the direction of the intake opening of the suction turbine, the blow-out side of the suction turbine delivers the created overpressure air into an overpressure chamber in which a chamber housing is disposed, the at least one drive element to be suddenly actuated comprises openings to be opened and closed, upon the opening of which the overpressure air flows through the chamber housing optionally into an impulse channel which branches off at that location and introduces the air into one or into the other filter chamber for cleaning.

The invention relates to a filter cleaning with a flap element according to the preamble of claim1.

The basic principle of the filter cleaning consists in that the particular filter compartment with the filter half to be cleaned is first disconnected from the suction air flow of the suction turbine and a false-air flow that is generated from the blow-out-air flow of the suction turbine is then passed into the filter compartment in a pulsed manner, in order to clean the surface thereof that is loaded on the outside with dirt particles in a direction from the inside to the outside.

Such a filter cleaning is known from the older patent DE 199 49 095 C2 of the applicant's. The false-air flow is controlled in such a way that an approximately X-shaped flap element disposed in a housing abruptly changes its position by utilizing differences in pressure between the suction air flow and the atmospheric pressure, and opens and/or closes one or a plurality of openings in the housing, such that the false-air flow reaches the one filter half to be cleaned in a pulse-like manner, while the other filter half remains in the suction air flow.

Since the air pulse is used also for switching over the flap element, energy for the cleaning is therefore lost. This reduces the pulse intensity of the blow-out-air cleaning burst.

EP 1 118 303 A2 discloses a similar, pressure-controlled switch-over of the flap element, which involves the same shortcomings.

In DE 101 01 219 B4 there is described a switch-over from a cleaning air flow to a suction air flow by means of two electromagnetically actuated three-way valves. Because two separately actuated three-way valves are used that are disposed in chambers which are separate from one another, the required effort and expense for implementing the chamber design and actuation of the valves is significant.

It is therefore the aim of the invention, proceeding from DE 101 01 219 B4, to ensure a reliable cleaning of the two filter halves, while at the same time providing for an improved degree of cleaning effectiveness.

This aim is achieved by the features of claim1.

According to the invention, an approximately Y-shaped flap element, comprising two flap parts that are disposed at an angle to one another, is now actuated by a cost-effective servomotor drive. Because such servomotors are used in a variety of applications in model-making, they can be used cost-effectively for the purposes of the invention.

In a preferred embodiment, the servomotor has a drive arm that engages with an associated U-shaped seat on a projection of the flap element and moves same into one or the other pivot position. Altogether, there are three different pivot positions, namely a central position of the flap element, a left and a right position.

In the central position the dirty-air flow flows through both filter halves and both of them are therefore in functioning mode, while in the right pivot position (FIG. 2) only the right filter half remains in functioning mode and cleans the dirt flow, while the left filter half is cleaned by the backflow that is generated in a pulse-like manner in the opposite direction from the dirt cleaning direction.

The discharged-air cleaning flow is induced by the abrupt opening of a control flap or control opening, an electromagnetically actuated solenoid being used for actuation of this control flap.

The following explanations are provided with respect to the prior art in comparison with the present invention:

While the known X-flap was not operated positively controlled, but instead was switched over by the incoming airflow, the present Y-flap is an electric-motor operated flap. This presents the advantage that one can, in one filter half, induce a plurality of cleaning pulses onto this filter half in succession, thereby attaining an improved cleaning of this filter half. The switch-over between one filter half and the other, accordingly, is a positively controlled switch-over.

The invention is characterized in that a flap element that can be actuated at will by means of an electric motor, electromagnetically, or in some other way, can be moved into three different pivot positions, and a neutral position exists in this arrangement in which both filter halves are in operation. The invention is further characterized in that, through the switch-over by means of the electric-motor drive, selectively one or the other filter half can be cleaned.

It is a further advantage of the invention that for the flap actuation for the cleaning air a single solenoid is provided that operates this single flap, whereas in the prior art two different solenoids with two different flaps were provided.

The advantage in this arrangement lies in that, according to the pivot position of the Y-flap, the cleaning air can be fed abruptly, in a pulse-like manner and in repeated succession, selectively to one or the other filter half, which was not the case in the prior art.

The subject matter of the present invention extends not only to the subject matter of the individual claims, but also to the combination of the individual claims with one another.

All of the details and features disclosed in the documents, including in the abstract, in particular the dimensional embodiment illustrated in the drawings, are claimed as essential to the invention, to the extent that they are novel over the prior art, either individually or in combination.

The invention is explained in more detail below with reference to drawings illustrating just one possible method of implementation. In the process, additional features and advantages of the invention will become apparent from the drawings and their description.

FIG. 1generally illustrates a vacuum cleaner comprising a receptacle6, inserted into which, in a sealing manner, is a filter arrangement comprising an annular filter, the annular filter comprising two filter halves1,2. The filter halves1,2are sealed off from one another and can be operated either in parallel, or one half can be cleaned and the other filter half can continue to remain in use. An intake nozzle3opens into the receptacle6, by means of which intake nozzle the intake air flows in, in the arrow direction4, and in the process—in the neutral position of FIG.1—flows through both filter halves1,2in the arrow directions4.

It is illustrated that the air from the intake nozzle3is distributed over the bottom space5of the receptacle6also in an annular pattern and therefore also flows through the right filter half2. The air flow in this case is effected in the arrow direction8. In order to simplify the illustration, the receptacle6is drawn very short and with a small volume. It can also be designed in the form of a bag or as a very large receptacle; importance being placed on that the entire annular filter is enclosed in the region of a seal7on the bottom, in order to create an inner filter space.

The switch-over element according to the invention comprises a Y-flap9comprising two partial flaps10,11that are arranged at an angle to one another and are connected to one another rigidly and supported in the region of a pivot bearing12in a manner so as to be able to pivot. Adjoining the pivot bearing12, integral in rotation therewith, is a lever13that ends in an upper, upwardly open fork14.

The lever13with the fork14engages in a sealed manner with a compartment housing42, through which the cleaning air that is generated in a pulse-like manner flows.

The drive axis of the servomotor36(seeFIG. 4) is connected to an actuation pin15integral in rotation therewith, which actuation pin is disposed on a pivoting part that is supported in a pivotable manner in a pivot point16on the housing of the vacuum cleaner.

The actuation pin15engages with the fork14and is capable, by means of a pivoting actuation of the lever13, of pivoting the Y-flap from a neutral position toward one side or the other. This causes either the one partial flap10or the other partial flap11to be moved against the outflow openings31,32for sealing same.

A solenoid18is used as the actuation means for the pulse flap17, which solenoid, however, in other embodiments, may also be designed in the form of some other element providing the same action. A servomotor, for example, or some other actuation element operating in a pulse-like manner can take the place of the solenoid18.

In the shown neutral position ofFIG. 1both filter halves1,2are thus in functioning mode. The dirt-laden air flows in the arrow direction4through both filter halves1,2and through the filter compartments38,39defined there and flows through the two outflow openings31,32because the two partial flaps10,11release the two outflow openings31,32. The outflow openings31,32are an air-conducting component of a collection channel37, in such a way that the air flowing in through the two openings31,32is drawn in, in arrow direction22, by the intake opening20of the suction turbine19, where it is compressed and leaves the blow-out opening21in the drawn arrow direction35. The air flowing into the filter compartment38,39is therefore drawn in, in the arrow direction22, by the suction turbine19via its intake opening20.

The suction turbine19delivers the air drawn in from the filter compartments38,39under overpressure into an overpressure chamber24. The clean air that has been compressed in this manner is transported to the outside via the blow-out channel23.

In the context of the present invention, provision may also be made, of course, that the air in the arrow direction35can also be used for cooling the suction turbine19. However, a separate cooling for the motor may also be provided.

Moreover, the overpressure chamber24is separated from the vacuum chamber of the vacuum cleaner by a wall33.

Because overpressure exists in the entire overpressure chamber24, in the neutral position of the pulse flap17this overpressure is not passed into the inner filter space. The reason being that the solenoid19holds the pulse flap17sealed by spring loading on the associated opening29in the compartment housing42. Consequently, there also is no pulse air in the pulse channels25,26branching off from the compartment housing42.

If, however, as shown inFIG. 2, the actuation pin15is displaced via actuation of the servomotor36into (the right) one of the pivot positions, then the partial flap11closes off the outflow opening32and the solenoid18is actuated only after the outflow opening32is closed completely, and the pulse flap17is therefore released from the opening29abruptly and the overpressure that has built up in the overpressure chamber24now flows abruptly via the opening29in the arrow direction30downward into the chamber42and in the process enters into the channel26that allows the pulse air to flow, in the arrow direction34, into the left vacuum cleaner space and flows, in the arrow direction34, from the inside to the outside through the left filter half1, thereby cleaning same. In the process, the fork14can close off the other, opposite opening to the pulse channel25in a sealing manner.

It is important that, when the partial flap11is closed, the solenoid can actuate the pulse flap17as often as desired in order to thus abruptly direct a plurality of successive pulse bursts in the arrow directions34against the inside of the filter half1and clean same with a high degree of efficiency.

The cleaning air accordingly flows via the blow-out opening28into the inner filter space.

If, on the other hand, as shown inFIG. 3, the Y-flap9is switched over, the blow-out air or cleaning air flows downward through the right blow-out opening27and the same cleaning process follows for the right filter half2.

FIG. 4shows further details of the drive, where it is illustrated that the servomotor36is disposed in the upper overpressure chamber24, the drive axis of the servomotor being connected to the actuation pin15via a lever.

In the above-described embodiment the cleaning of two partial filters (1,2) was described. However, the invention also relates to the cleaning of three or more partial filters. All of the above explanations shall then be understood analogously.