Vacuum cleaner having a motor-fan unit and a fine filter disposed in an exhaust air stream thereof

A vacuum cleaner includes a motor-fan unit and a housing part including a filter receptacle. A filter frame is slidably insertable in an insertion direction into the filter receptacle so as to be disposed in an exhaust air stream of the motor-fan unit. The filter frame has a substantially parallelepiped configuration and is configured to receive a fine filter. The vacuum cleaner includes an air-permeable cover element pivotably disposed on the housing and configured to cover the filter receptacle. The cover element is operable to redirect force resulting from a pivoting movement thereof from the insertion direction to a pressing direction substantially perpendicular to the insertion direction so as to press an edge contour of the filter frame toward a mating contour of the filter receptacle in an inserted position of the filter frame.

CROSS REFERENCE TO RELATED APPLICATIONS

Priority is claimed to German patent application DE 10 2007 040 963.1, filed Aug. 30, 2007, which is hereby incorporated by reference herein.

FIELD

The present invention relates to a vacuum cleaner including a motor-fan unit which has disposed in its exhaust air stream a cartridge-like filter frame insertable in the manner of a drawer into a filter receptacle of a housing part of the vacuum cleaner.

A vacuum cleaner having a fine filter is described, for example, in DE 42 40 172 C2. In that patent, a filter mat designed as a fine-particulate or hygienic filter is disposed in a cartridge-like holder. In the vacuum cleaner described in DE 42 40 172 C2, which is hereby incorporated by reference herein, the holder is placed flat onto the air outlet of the fan. The force required to achieve a sealing effect is produced by projecting portions of a cover, which are produced when a housing cover is pivoted onto a peripheral flange.

In addition to the above-described flat mounting position of a filter cartridge, DE 202 07 256 UI describes sliding a filter cartridge in the manner of a drawer into a receptacle provided for this purpose. Such a drawer-type receptacle may be useful when there is insufficient space for a flat receptacle. A disadvantage of this holder is that in order to obtain the sealing effect, contact-pressure must be exerted in a direction perpendicular to the insertion direction. In DE 202 07 256 U1, the required pressing force to be exerted on the cartridge, or on the seal thereof, is produced by sloping control segments cooperating with a mating control surface which is also sloped. When inserting the cartridge, the seal is stressed both in the pressing direction and in the insertion direction. This causes wear of the seal and, in the worst case, the adhesive bond between the filter frame and the seal fails, and the seal is moved from its seat to a region outside the intended contact area.

SUMMARY

In view of the above, an aspect of the present invention is to provide a vacuum cleaner wherein damage to the sealing surface is reduced or prevented while, at the same time, sufficient contact pressure is exerted on the filter frame.

In an embodiment, the present invention provides a vacuum cleaner with a motor-fan unit and a housing part including a filter receptacle. A filter frame is slidably insertable in an insertion direction into the filter receptacle so as to be disposed in an exhaust air stream of the motor-fan unit. The filter frame has a substantially parallelepiped configuration and is configured to receive a fine filter. The vacuum cleaner includes an air-permeable cover element pivotably disposed on the housing and configured to cover the filter receptacle. The cover element is operable to redirect force resulting from a pivoting movement thereof from the insertion direction to a pressing direction substantially perpendicular to the insertion direction so as to press an edge contour of the filter frame toward a mating contour of the filter receptacle in an inserted position of the filter frame.

DETAILED DESCRIPTION

The present invention relates to a vacuum cleaner including a motor-fan unit which has disposed in its exhaust air stream a cartridge-like filter frame of substantially rectangular parallelepiped configuration for receiving a fine filter; said filter frame being insertable in the manner of a drawer into a filter receptacle of a housing part of the vacuum cleaner and, when inserted, being able to be pressed with an edge contour against a mating contour of the filter receptacle, possibly with a seal interposed therebetween; and the direction of movement for inserting the filter frame being substantially perpendicular to the direction in which the pressing force is applied.

In an embodiment, the present invention provides a pivotably mounted cover element which covers the filter receptacle when the filter frame is in the inserted position and which causes the force resulting from the pivoting movement to be redirected from the insertion direction to the pressing direction. This prevents wear of the edge contour and/or of the seal. Furthermore, the cover element can be used as a lever. In this manner, the forces that the user has to exert to obtain the sealing effect are kept low.

In an embodiment, first retaining means in the form of a projection are provided on at least a portion of the edge contour, said first retaining means cooperating with second retaining means in the form of a recess in the lower region of the filter receptacle. This ensures that the filter frame performs a defined pivoting movement about the retaining means when the cover is being closed. As the frame is being pressed against the contour of the filter receptacle, any relative movement perpendicular to the pressing direction is prevented.

In order to achieve sufficient contact pressure, the cover element may include at least one pressure rib having a curved contour.

Since the cover element is retained in the closed position by self-locking action, there is no need for any additional closure means.

The seal may be disposed on the edge contour of the filter frame.

In an embodiment of an upright vacuum cleaner, the motor-fan unit and the filter receptacle can be mounted in a base unit. This allows for easy filter replacement and provides short air paths from the fan to the fine filter.

FIG. 1shows, in an exploded view, base unit2of an upright vacuum cleaner, said base unit having a housing including a housing insert5, a lower rear housing part6, a lower front housing part7, a bumper strip8, and a cover part9. Housing insert5functions as a support for a number of electrical and mechanical components. The aforementioned housing parts are also attached thereto. The housing insert, lower rear housing part6, and a motor chamber seal10placed therebetween, together form a chamber for receiving a motor-fan unit11for creating the partial vacuum required for vacuuming. A sealing ring13is provided around fan inlet12on the suction side, said sealing ring also bearing against the two aforementioned housing parts5and6. Rubber buffers14are inserted on the opposite side. For deep cleaning of carpets, a brush roller17extends into suction mouth15, which is an opening in lower front housing part7and bottom plate16, which is attached thereto, said brush roller being resiliently mounted on two lateral pivoting arms18and19and being driven by a brush motor20via a belt21. A two-part belt cover is provided by parts22and23. Brush motor20is also attached to housing insert5, and pivoting arms18and19are pivotably secured thereto. The carriage of the upright is formed by front casters24and25and rear wheels26and27and is supported by the two lower housing parts6and7. Rear wheels26and27are connected by an axle28for purposes of stability, and are adjustable in position by means of a wheel mechanism29and30, respectively. A circuit board31carrying LEDs32is secured to housing insert5to illuminate the travel path and is covered at the front by a transparent plate33. Transparent plate33is held in a cut-out34in bumper strip8.

The air generated by the motor-fan unit11is discharged into the environment through an opening35in housing insert5and a corresponding opening36in cover part9. A filter frame37is inserted into opening36to hold an exhaust filter for removing ultrafine particles from the exhaust air. Filter frame37is covered by a grating holder38and a grating39within cover part9, from where it can be replaced.

Both the tilting joint and the swivel joint between base unit2and an upper body are provided by a rigid, yoke-shaped duct member. This member also contains portions of the air passageway from suction mouth15to upper body3, and the air passageway from upper body3to the exhaust port (openings35and36). This member is hereinafter referred to as yoke40. It is formed by two plastic parts, namely an upper shell41and a lower shell42, which are welded together. In order to create the tilting joint, the two ends43(right) and44(left) of yoke40are pivotably mounted in openings45and46provided for this purpose, and are surrounded by metal bearing sleeves47and48, respectively, in order to avoid wear. Yoke end44, which is on the left side as viewed in the direction of travel, is hollow and is coupled to fan inlet12via a seal49. A trunnion50is integrally formed with yoke end43, which is on the right side as viewed in the direction of travel. Moreover, the right yoke end has an opening51which is connected by a flexible tube52to suction mouth15. In order to prevent the interior of base unit2from becoming visible when tilting the upper body3, the connecting portion between the two yoke ends43and44(hereinafter referred to as bridge portion53) is enclosed by a front cover54and a rear cover55, which are provided on base unit2and are capable of following the swivel motion of yoke40. The gap between the front and rear covers and housing insert5is bridged by covering members or skirts56and57. The first58of two cable ducts58and59is attached to left yoke end44. Furthermore, yoke ends43and44carry toothed segments60and61, which cooperate with wheel mechanisms29and30. A covering cap62for a connecting cable is secured to bridge portion53. To enable the upright to be locked in the upright position, a foot pedal63is mounted on housing insert5which, in this position, engages with left yoke end44, thereby preventing yoke40from swiveling. The locked position can be released by depressing pedal63. Moreover, in the locked position, swivel motion is prevented by two spring-mounted pins64and65. In the region of bridge portion53, the air passages provided by yoke ends43and44are combined into a first section66of a coaxial conduit.

FIG. 2shows the rear portion of base unit2, including cover part9, front cover54, lower rear housing part6, and housing insert5. Grating holder38and a grating39are joined to form an air-permeable cover element (hereinafter referred to as closure100), and hinged to cover part9. When assembled, lower rear housing part6and housing insert5together form the chamber for receiving motor-fan unit11and the opening35for the exhaust air stream thereof. Opening35is surrounded by a rectangular contour101. Furthermore, when assembling the two subassemblies, a filter receptacle102is created, into which filter frame37can be inserted along with the fine filter in the manner of a drawer. Shown are only the general features of filter frame37, namely side walls370, rear wall371, edge contour372, and seal373. The remainder of the construction may be similar to that described in DE 42 40 172 C2, and, therefore, is not further described. When inserting the filter frame, first the closure100is pivoted rearward by pulling on a handle103provided for this purpose. Then, filter frame37, together with the fine filter placed therein, is inserted into filter receptacle102in the direction of black arrow104(seeFIGS. 2 and 3a). For increased ease of handling and to prevent inverted insertion, a gripping tab374is formed on one side wall of filter frame37.

To ensure that the lower portion of frame37is placed in a defined position, the side of the edge contour372opposite tab374has projections375which are associated with recesses in the lower region of filter receptacle102. Housing insert5has formed thereon guide segments106which enable projections375to reliably slide toward recesses105during the insertion of frame37. After filter frame37has fallen to the position shown inFIG. 3bdue to its own weight, the procedure for closing closure100begins. To this end, the closure is pivoted in a clockwise direction. First, integrally formed pressure ribs107press against the edge376between upper side wall370and rear wall371. In this manner, filter frame37is pushed down until projections375are received by recesses105. The slope of the guide segments106and the depth of recesses105are selected such that seal373engages contour101only after the insertion process is completed.

As the closure is pivoted further (FIG. 3c), the contact point of pressure ribs107moves from edge376onto rear wall371because of the curved contour of said pressure ribs. Thus, filter frame37is pressed with the entire seal373against contour101in the direction of white arrow108(seeFIG. 2), i.e., perpendicular to the insertion direction, in the manner of a toggle mechanism.

The curved contour of pressure ribs107merges into reinforcements109having a slope110, which further increase the pressure against the rear wall shortly before the end of the pivoting operation (FIG. 3d). The adjoining straight run-out portion111provides a self-locking action when closure100is in the closed position (FIG. 3e). When closure100is opened, filter frame37is immediately released and can easily be removed.

The present invention has been described herein based on one or more exemplary embodiments, but is not limited thereto. Reference should be had to the appended claims.