Filter stop for a vacuum cleaner

A filter stop for a vacuum cleaner contains a dust chamber that is closable with a lid and receives a dust bag with a reinforcement plate in a specific fitting position. The filter stop has a base plate that is movable between two stopping positions parallel to the direction in which the reinforcement plate of the dust bag is inserted into the dust chamber. The filter stop is also provided with a swiveling lever that can be brought into a position activating the vacuuming function of the vacuum cleaner by the reinforcement plate when the dust bag is correctly positioned. The swiveling lever is in a position preventing the vacuuming function from being activated when the dust bag is not correctly positioned. The filter stop can be brought into a stop position activating the vacuuming function exclusively when the swiveling lever is actuated by a shoulder of the reinforcement plate.

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The invention relates to a filter stop for a vacuum cleaner having a dust chamber that can be closed by a cover and is intended for accommodating a dust-retention device with a reinforcement plate in a defined installation position. The filter stop contains a base plate which can be displaced between two stop positions, parallel to a pushing-in direction of the reinforcement plate of the dust-retention device, and on which a pivoting lever is disposed.

Known electric vacuum cleaners are usually provided with filter bags made of fabric, paper or paper-fabric, in which the dirt that is taken in is collected and retained. Such a filter bag of the generic type and the way in which it is secured in the vacuum cleaner can be gathered, for example, from Published, European Patent Application EP 0 396 864 A1, corresponding to U.S. Pat. No. 5,028,245. A further vacuum cleaner with a retaining device for a filter bag of the generic type is also known from German Patent DE 40 40 099 C2. The retaining device here is disposed on a removable cover that closes the dust chamber. The filter bag can be fastened on the retaining device by a rigid retaining plate, as a result of which an inlet opening located in the retaining plate can be connected to an intake connector of the vacuum cleaner.

In the case of these known devices, it is possible for the filter bag, in unfavorable circumstances, to be inserted incorrectly or forgotten altogether. In the case of a filter bag being inserted incorrectly or being absent, there is a risk of the dirt that is taken in, in particular fluff and threads, passing into the motor fan and resulting in damage there. In addition, a dirt-filled bag-accommodating chamber in the vacuum cleaner is very difficult to empty and to clean. In order to avoid these problems, various embodiments of filter stops are known, these embodiments essentially all being based on preventing the start-up of the fan motor in the case of the filter bag being inserted incorrectly or being absent, or else on preventing closure of the flap of the filter-bag-accommodating chamber.

Published, Non-Prosecuted German Patent Application DE 34 07 658 A1 discloses a filter stop on a vacuum cleaner that contains a lever that is disposed on the vacuum-cleaner housing and can be pivoted by the spring force into the closing path of a cover which closes the dust chamber. This lever is interlocked in an opening located on the reinforcement plate of the filter bag and is thus retained outside the closing path. The filter stop is actuated in that the lever is disposed on the suction-connector-containing front wall of the dust chamber and the reinforcement plate has a vertical incision into which the lever can be pivoted by hand. In the case of the dust bag being absent or being positioned incorrectly, the cover that closes the dust chamber cannot be completely closed or latched in.

A further vacuum-cleaner filter stop of the generic type which only allows a vacuuming function of the vacuum cleaner when the filter bag has been positioned correctly in the guide elements via its filter-bag flange is known from Published, Non-Prosecuted German Patent Application DE 39 20 313 A1. By virtue of the filter bag positioned in the guide elements, an actuating element can be moved out of a position in which the vacuum function of the vacuum cleaner is prevented into a position in which the vacuum function is released. In the case of this filter stop, the guide elements and the filter-bag flange are matched to one another, with the result that the actuating element can only release the vacuum function when the filter bag is positioned correctly.

Finally, German Patent DE 40 13 572 C2 discloses a filter stop of the generic type. The vacuum cleaner described in this document has a blocking member that is configured as a single-part slide and can be moved in the direction of the adjustment path of a cover for the dust-bag chamber. The blocking member engages with the cover and is pushed in the direction of the cover, and into a blocking position, by a spring, an inserted reinforcement plate of the dust bag moving the blocking member out of the blocking position. In the case of the reinforcement plate being absent, the closure of the cover is thus blocked by the blocking member, with the result that it is difficult for incorrect operation of the vacuum cleaner without a filter bag to take place.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a filter stop for a vacuum cleaner which overcomes the above-mentioned disadvantages of the prior art devices of this general type, which can prevent operation in the case of the dust bag being positioned incorrectly or being absent.

With the foregoing and other objects in view there is provided, in accordance with the invention, a filter stop for a vacuum cleaner having a dust chamber which can be closed by a cover and intended for accommodating a dust-retention device with a reinforcement plate in a defined installation position. The filter stop contains a base plate to be displaced between two stop positions, parallel to a pushing-in direction of the reinforcement plate of the dust-retention device. The base plate has a pivoting lever. The pivoting lever can be pivoted, by a shoulder of the reinforcement plate of the dust-retention device disposed at a correct installation position, into a first stop position of the two stop positions. Placement at the first stop position allows a vacuuming-function-releasing stop position of the base plate to be reached, and, with the dust-retention device disposed outside the correct installation position, the pivoting lever is disposed in a position which prevents the first stop position of the base plate from being reached.

According to the invention, it is possible for the filter stop to be used not just in conjunction with a dust bag, but also in conjunction with any other device for retaining the dust or the dirt, that is say also a dust separator or a cyclone.

Accordingly, the filter stop for the vacuum cleaner which has a dust chamber which can be closed by a cover and is intended for accommodating a dust bag with the reinforcement plate in a defined installation position contains a plate which can be displaced between at least two stop positions, parallel to the pushing-in direction of the reinforcement plate of the dust bag, and also contains a pivoting lever. With the dust bag located in the correct installation position, the pivoting lever is located in a position in which the vacuuming function of the vacuum cleaner is released or allowed. With the dust bag located outside the correct installation position, the pivoting lever is located in a position in which the vacuuming function is prevented.

According to the invention, the filter stop can only be moved into a first stop position, in which the vacuuming function of the vacuum cleaner is allowed, when the pivoting lever is actuated or pushed by a shoulder of the reinforcement plate. The filter stop according to the invention is associated with the advantage of operation of the vacuum cleaner without the dust bag, or with an incorrectly positioned dust bag, being reliably prevented, in that the filter stop can only be located in a first stop position when the reinforcement plate of the dust bag is in its envisaged installation location.

According to a first embodiment of the invention, if the dust bag is absent or has not been pushed all the way in, the filter stop is blocked in a second stop position, in which the vacuuming function of the vacuum cleaner is prevented. The filter stop can only be displaced between these two stop positions when the dust bag is placed in position.

A further aspect of the invention makes it possible for the cover of the dust chamber to be closed exclusively when the dust bag is placed in position, the filter stop, according to the invention, being located in the first stop position. This gives a clear signal to any operator that the dust bag has either been positioned incorrectly or is even absent. It is only in these cases that the cover of the dust chamber cannot latch in, as a result of which the incorrect operation of the vacuum cleaner with ineffective dust collection is virtually ruled out. According to this aspect of the invention, the filter stop reliably blocks closure of the cover of the dust chamber as soon as the filter stop is located outside the first stop position and, in particular, in its second stop position.

The filter stop preferably has at least two latching elements that engage in a releasable manner with a mount in the housing of the vacuum cleaner and/or with a shoulder on the reinforcement plate of the dust bag. This ensures both reliable guidance of the filter stop and reliable mechanical interaction with the dust bag and the cover of the dust chamber.

One embodiment of the filter stop provides that the dust bag can only be removed if the first latching element or the second latching element is unlocked manually. It is thus possible to check the correct operation of the filter stop at any time. Since the dust bag can only be removed by manual unlocking of one of the latching elements, it is possible to check, during each removal, whether the filter stop is operative. In the case of a further embodiment of the filter stop according to the invention, the filter stop can only be removed if the second latching element is unlocked manually, which results in monitoring of the correct functioning of the filter stop being ensured at all times.

In an advantageous further configuration, the filter stop may be configured such that the pivoting lever of the filter stop is connected to a switch that only releases the vacuuming function of the vacuum cleaner when the dust bag is positioned correctly. This is associated with the advantage that operation of the vacuum cleaner without the dust bag, or with the dust bag positioned incorrectly, can be reliably ruled out. The switch, which prevents or allows the vacuuming function, may be, for example, a mechanically actuated electric switch. Also suitable as an alternative is an optical sensor, which may supply an electric switching signal. Such switches can be used to block the vacuuming function of the vacuum cleaner reliably as soon as the dust bag is absent or else has just been pushed in incorrectly. Other configurations of the switch, for example magnetic switches or reed switches or the like, are basically also suitable.

A further configuration according to the invention provides that the first latching element is a first latching hook that is brought into engagement with the first shoulder on the reinforcement plate. The second latching element is preferably a second latching hook that is brought into engagement with a corresponding second shoulder in the housing. The dust bag can thus latch in reliably and, in the correctly positioned state, ensures corresponding deflection of the pivoting lever.

The filter stop preferably is formed of an elastic polymer material, for example polyamide. Also suitable, in addition to a thermoplastic material, is a thermoset material which, in addition to the desired strength, has the elastic properties required.

One embodiment according to the invention provides that, if the reinforcement plate of the dust bag located in the correct installation position has been pushed all the way in, the pivoting lever is pushed, by a third shoulder in the housing, into a position in which the vacuuming function of the vacuum cleaner is allowed, the first latching hook engaging with the first shoulder. The dust bag then cannot slip during operation and ensures the deflection of the pivoting lever, which thus releases the suction operation of the vacuum cleaner.

It may further be provided that, with the reinforcement plate pushed part of the way out of the correct installation position, the displaceable filter stop is pushed, by the first latching hook, which engages with the first shoulder, into a position in which the second latching hook engages with the second shoulder, the pivoting lever, at the same time, being located in a position in which the vacuuming function of the vacuum cleaner is prevented. The dust bag thus still cannot be removed; it has to be first mechanically unlocked. Nevertheless, the vacuuming function of the vacuum cleaner is blocked even in this position, in order to prevent damage to the suction motor as a result of solids and dirt flowing past the filter bag.

The invention is also concerned with a dust bag with a reinforcement plate for use in a vacuum cleaner with the above-described filter stop. In the case of such a dust bag, the reinforcement plate has a shoulder that interacts with a pivoting lever of the filter stop.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the figures of the drawing in detail and first, particularly, toFIG. 1thereof, there is shown a perspective schematic illustration of a filter stop2according to the invention for a vacuum cleaner. The filter stop2contains a substantially rectangular base plate4which has an approximately central first longitudinal rib30which extends from one narrow side to the opposite narrow side of the base plate4. A second longitudinal rib32extends from one narrow side of the base plate4over a length of approximately two thirds of the longitudinal side of the latter. The two longitudinal ribs30,32each have shallow bevels at their ends and have a height which corresponds approximately to 20% to 30% of the width of the base plate4. The longitudinal ribs30,32serve predominantly for reinforcing the base plate4and, otherwise, have no significant further function. The length of the narrow sides of the base plate4corresponds approximately to 25% to 30% of the length of the longitudinal sides. Typical dimensions for the base plate4of the filter stop2may be, for example, approximately 15 to 20 mm for a narrow side and approximately 50 to 60 mm for a longitudinal side.

Provided on one longitudinal side of the base plate4, furthermore, is a sidewall which is subdivided into a first sidewall section40and a second sidewall section42. The sidewall is somewhat thicker than the longitudinal ribs30,32and is interrupted at one location. Between the centrally disposed first longitudinal rib30and the sidewall, the base plate4has a first, rectangular cutout34which has one longitudinal side not quite adjacent to the first longitudinal rib30and, on its opposite longitudinal side, is fully adjacent to the second sidewall section42. The first sidewall section40terminates level with a bottom narrow side of the first cutout34. The top narrow side of the latter terminates some way above the center of the second sidewall section42.

The second sidewall section42is freely suspended along the longitudinal side of the first cutout34and thus forms a resilient pivoting lever52. The pivoting lever52, furthermore, on an outer side which is directed away from the base plate4, has an oblique stub38, which has a curved resilient clip16disposed on its opposite side. The resilient clip16, which projects more or less perpendicularly from the inside of the second sidewall section42and/or of the pivoting lever52, describes a curved contour within the first cutout34and terminates shortly the top narrow side of the latter.

By virtue of the first cutout34, which is directly adjacent to the second sidewall section42, the second sidewall section42, which forms the pivoting lever52, is flexible over this length and can be bent relatively easily inward in the direction of the first-cutout34, as a result of which the resilient clip16is likewise bent inward in the direction of the first longitudinal rib30.

A first latching element12in the form of a nose-shaped first latching hook20is provided at the top end of the second sidewall section42. The latching hook20has a small surface perpendicular to the second sidewall section42and a larger, inclined surface in the direction of the top narrow side of the base plate4. The small surface of the first latching hook20is suitable for engaging with a first shoulder of the reinforcement plate of the dust bag, the first shoulder being described in more detail inFIGS. 4 to 6.

Finally, a second cutout36is provided in the base plate4beneath the second longitudinal rib32, in the vicinity of the bottom narrow side. The second cutout36has a contour that is partly rectilinear, parallel to the first longitudinal rib30, and partly oblique and meeting up with the right-hand longitudinal side of the base plate4with an acute angle of approximately 30 to 60°. Provided within the second cutout36is a slightly obliquely upwardly projecting, second latching element14, which, as a second latching hook24, interacts with a second shoulder in the housing, the shoulder being illustrated in more detail inFIGS. 4 to 6.

The filter stop2may preferably be configured in one piece and may advantageously be produced by injection molding from thermoplastic or thermoset material. Particularly suitable material for this purpose is polyamide, which lends itself well to processing and, in the cured state, has a high level of mechanical stability with, at the same time, sufficient elasticity.

FIGS. 2A and 2Beach show schematic plan views of the filter stop2as inFIG. 1.FIG. 2Ashows a view of the base plate4as seen obliquely from beneath. It is possible to see here, on the left-hand side, the second longitudinal rib32, by which the first longitudinal rib30is virtually completely concealed. It is also possible to see the contours of the second cutout36and of the second latching element14disposed therein.FIG. 2Bshows essentially the same parts as have already been described with reference toFIG. 1. This slightly inclined plan view illustrates the longitudinal ribs30,32obliquely.

FIG. 3Ais a cross-sectional view taken along the line IIIA—IIIA fromFIG. 3B, which shows a plan view from beneath of the base plate4on the filter stop2. The details which-can be seen inFIG. 3Bhave already been described with reference toFIG. 1.FIG. 3Aillustrates the precise contours of the base plate4, with the longitudinal ribs30,32disposed perpendicularly thereto and with the side wall with its two side-wall sections40,42disposed slightly obliquely in relation to the ribs.

FIG. 4shows a schematic illustration of the filter stop2in the installed state interacting with a reinforcement plate8of a dust bag6that is used in the housing1of a vacuum cleaner. Such a reinforcement plate8may be formed, for example, of relatively stable cardboard or else of a slightly flexible sheet of polymer material. The reinforcement plate8is retained by a guide rail44,46of the housing1, in each case on its two longitudinal sides and, if required, can be drawn out upward and thus removed from its installation location. The filter stop2is pushed in to the right of the second guide rail46, the filter stop2having its sidewall sections40,42butting against the second guide rail46and being retained essentially by a protrusion48of the second guide rail, the protrusion48gripping over the sidewall sections40,42.

In the illustration shown inFIG. 4, the dust bag6has been pushed all the way in, with the result that the central opening in the reinforcement plate8here is completely aligned with an intake opening10of the vacuum cleaner. The filter stop2, in contrast, has not yet been pushed all the way in, and its bottom narrow side is not yet butting against a bottom stop50of the housing1. On the right-hand longitudinal side of the filter stop2, it is possible to see a second shoulder26, which grips over the base plate4, can interact with the second latching hook24of the filter stop2, and, by butting against the same, can prevent the filter stop2being drawn out upwards. In the illustration shown, the filter stop2has been pushed downward precisely to the extent where the second latching hook24, which is pushed resiliently downward by the second shoulder26, has been released again and is relieved of stressing.

The filter stop2is thus located in its second stop position II, in which the vacuuming function of the vacuum cleaner is blocked. This is essentially achieved in that part of the cover of the dust chamber strikes against a top section of the filter stop2(for example on the base plate4in the vicinity of the top narrow side) and is thus prevented from closing or from latching in.

On its right-hand longitudinal side, the reinforcement plate8has a first shoulder22which, in the position of the filter stop2which is shown, pushes against the stub38on the pivoting lever52of the second sidewall section42and thus pushes the resilient clip16inward into the first cutout34. In this position of the pivoting lever52, the filter stop2can be pushed downward, without obstruction, into its first stop position I (seeFIG. 5), as a result of which the vacuuming function of the vacuum cleaner is allowed since, in this position of the filter stop2, the cover cannot latch in without obstruction.

FIG. 5illustrates the operating position of the vacuum cleaner with the dust bag6pushed all the way in and the filter stop2pushed in against the bottom stop50of the housing1(first stop position I), the pivoting lever52here having been pushed to the right and a vacuuming function of the vacuum cleaner having been released or allowed in that the cover of the dust chamber can latch in. In this position, the first latching hook20on the top edge of the second sidewall section42butts against the top edge of the first shoulder22of the reinforcement plate8. The second shoulder26is spaced apart from the second latching hook24.

Finally,FIG. 6shows a dust bag6that has been drawn upward out of its correct installation position, which can be seen from the fact that the intake opening10of the vacuum cleaner is not aligned with the round opening in the reinforcement plate8. The reinforcement plate8, at the same time, is located at its top stop, via which it can only be withdrawn from the filter stop2by manual release. For this purpose, the filter stop2or the reinforcement plate8has to be bent elastically, and with the result that the first shoulder22of the reinforcement plate8can be released from the first latching hook20of the filter stop2. The filter stop2itself, which in this illustration is located, once again, in its second stop position II, can only be removed upward by the second latching hook24being pushed downward, with the result that it can slide through beneath the second shoulder26.

In the position shown, the second latching hook24of the filter stop2butts against the second shoulder26of the housing1and thus cannot slide further upward. The first shoulder22of the reinforcement plate8of the dust bag6, in turn, butts against the first latching hook20of the filter stop2, with the result that it is not possible either for the dust bag to be moved further upward. The stub38is completely free in this position, with the result that the pivoting lever52and the resilient clip16are also located in the position in which they are relieved of stressing. The vacuuming function of the vacuum cleaner is prevented. This reliably prevents the vacuum cleaner from being able to operate in the case of an incorrectly positioned or absent dust bag6. The correct installation position of the dust bag is ensured, furthermore, in that the filter stop2has to be pushed manually downward against the stop50after the dust bag6has been changed in each case.

The invention is not restricted to the preferred exemplary embodiments specified above. Rather, a number of variants that make use of the solution illustrated, even in the case of basically different types of configuration, are conceivable.