Patent Publication Number: US-2010107358-A1

Title: Vacuum cleaner nozzle

Description:
TECHNICAL FIELD 
     The present invention relates to a vacuum cleaner nozzle, which nozzle has a front edge and a rear edge, an underside intended to face a floor or some other substructure to be vacuum-cleaned, and an upper part provided with a connection for connecting the nozzle to the vacuum-cleaner, which underside is provided with one front and two rear rest surfaces for supporting of the nozzle on the floor or similar, the front rest surface being positioned centrally along the front edge and the two rear rest surfaces being positioned separate from each other and symmetrically along the rear edge. 
     PRIOR ART 
     A floor nozzle of the above mentioned type is previously known from e.g. DE-C2 31 00 164 (≈U.S. Pat. No. 4,458,378) and is intended to be easy to handle also when vacuum-cleaning relatively dense air permeable carpets and thereby to provide for a sufficient cleaning action. Since it is a pure carpet nozzle it is not suitable for vacuum-cleaning smooth, hard floors. 
     For many years, most floor nozzles for all-round use have been provided with a brush rim that extends around the circumference of the nozzle and that is lowered in connection with the vacuum-cleaning of smooth floors and raised in connection with the vacuum-cleaning of carpets in which latter case the nozzle slides on a bottom plate that usually is provided with one lint pickup in front of and one behind the suction opening of the nozzle. Such lint pickups are for example described in U.S. Pat. No. 4,319,379 and consist of strips of plush or velveteen type material that nowadays are made of a plastic material having all the fibres thereof made at a slight inclination in the same direction. When such a strip is used as a lint pickup, it slides easily over a carpet when the relative movement is with the nap, but in the opposite directional movement the fibres stand up as rakes and collect any threads and the like that it runs across. The two lint pickup strips are therefore assembled with their fibres inclining towards each other, towards the suction opening of the nozzle. When the brush rim around the circumference of the nozzle is lowered, the lint pickups do not reach the floor but are inactive. 
     Nozzles for all-round use can have rolling wheels or sliding strips or steel pins for sliding in order for the nozzles to be easier to push forward and pull back in connection with the vacuum-cleaning. It is a problem in connection with the use of wheels that hair from humans, dogs and other pets is wound up on the wheel shafts during vacuum-cleaning, finally to brake the rotation of the wheels completely such that, if not noticed in time, the wheel will slide on the floor and a part of the circumference of the wheel will be worn down and become planar. Nozzles with sliding strips of fibre material, such as a felt-like material, that extend in the normal direction of movement back and forth of the nozzle during vacuum-cleaning are known e.g. from EP-B1 0 865 406 and SE-C2 523 406. When the nozzle is pushed back and forth over e.g. carpet edgings, laths, etc., such sliding strips may however hitch on these and in time even be ripped off from the nozzle. SE-C2 523 406 hence suggests that the end surfaces of the sliding strips are cut off obliquely in order to decrease the risk of hitching. 
     GB 400,618 A shows a nozzle with three pads and an outer flange that acts as rest surfaces and the nozzle. Three channels are formed between the pads and the outer flange, a middle channel being in fluid communication with a front and a rear channel, respectively, and containing a centrally positioned exhaust. The nozzle seems to be adapted for wall-to-wall fitted carpets or other soft substructures while hard floors might be scratched. 
     DE 203 121 836 U1 discloses a nozzle with three pads in contact with the substructure, one or two rear pads and an oblong front pad along the entire length of the front edge, such that the air can be sucked through the short sides of the nozzle. 
     DE 103 01 113 A1 discloses a nozzle with at least one lint pickup arranged before or after the suction opening. The lint pickup(s) is/are arranged to pivot in recesses such that they are folded down when they scrape up lint and are pivoted away when they part with the lint.  FIG. 1  shows a bottom plate for a nozzle with a central lint pickup  4  at the front edge, and immediately behind it a suction opening  3  followed by a second lint pickup  4 ′. In the shown embodiment, the rear portion of the nozzle is so large that even the second lint pickup  4 ′ is positioned in front of the middle of the nozzle. It seems that the air is sucked in only via one channel that mouths in the short sides of the nozzle. 
     BRIEF ACCOUNT OF THE INVENTION 
     One object of the present invention is to achieve a nozzle without any loose parts, which can be used as an all-round nozzle for carpets as well as smooth floors, and which can be produced at low cost and still give the desired cleaning effect in use. 
     In the nozzle mentioned in the introduction, this objective is achieved by the rest surfaces according to the invention comprising lint pickups that project from the rest surfaces and by the nozzle being free from other rest surfaces that might get in contact with a smooth, hard floor. The front, centrally positioned rest surface and its lint pickup take up about a third of the length of the front edge, while the portions on the side thereof of the front edge form front inlet channels for dust loaded air to be sucked into the vacuum cleaner. Such a nozzle can be used as an all-round nozzle that is adequately easy to move around on carpets as well as on smooth, hard floors. It has no movable parts whatsoever and is cheap in production. 
     Preferably, the lint pickups have inclined fibres arranged such that the fibres of the front rest surface incline towards the rear edge and the fibres of the rear rest surfaces incline towards the front edge. 
     The lint removers can be directly mounted on the rest surfaces but suitably they are recessed pockets formed in the rest surfaces. In that way, adapting between the stiffness of the fibres and their mobility and length projecting from the rest surfaces, is facilitated. The lint pickups are moreover protected from being scraped off from the rest surfaces. It is suitable that the lint pickups project a distance in the magnitude of 1 to 2 mm from the rest surfaces. 
     The two rear, separately positioned rest surfaces and their lint pickups preferably take up about one third each of the length of the rear edge, and the portion between them of the rear edge forms a centrally positioned rear inlet channel for dust loaded air to be sucked into the vacuum cleaner. The chosen positioning of the lint pickups with the central, front one at the apex and the two rear ones at the base corners of an equally sided triangle, and the friction between the inclined fibres of the lint pickups and the substructure to be vacuum-cleaned, will make the nozzle self-cleaning. 
     The front inlet channels suitably extend somewhat over the front corners of the nozzle. Hereby, the vacuum-cleaning of corners between walls or between a wall and furniture, etc., is improved. 
     The rest surfaces are advantageously designed such that a rest surface portion that is positioned between a lint pickup and an inlet channel that passes it, inclines away from the lint pickup in a direction towards the inlet channel. Hereby, the cleaning ability of the nozzle is improved. 
     The nozzle preferably comprises a bottom plate in which the rest surfaces and the channels are formed, and a top cover connected to the bottom plate, which cover comprises the connection for connecting the nozzle to the vacuum-cleaner. The two front inlet channels each lead to a respective hole through the bottom plate, such that the dust loaded air is sucked into a room that is defined by the cover and the bottom plate. These holes are positioned between respective ends of the central, front rest surface and the respective adjoining rear rest surfaces and the bottom plate is designed to split the rear inlet channel in two, such that the two branches formed lead to a respective one of the holes. The two front channels are furthermore advantageously extended such that they extend also beyond their own holes and up to the other respective hole. Hereby, the sucked-in air flows are better balanced. If desired, it is also possible to increase the flow velocity the closer to the holes you get, by designing the channels such that their height is gradually decreased from the edges of the nozzle and up to the holes. 
     Suitably, the bottom plate is, at least at one end of each pocket for the associated lint pickup, provided with a recess in order to facilitate introduction of a tool for loosening and exchanging of the lint pickup. Thereby, it is possible to change to a lint pickup with other properties, such as for needle-loom carpets or clinker floors that have sharp edges between the slabs. 
     It is also suitable that the sides of the channels are softly rounded in order to minimize the flow resistance and to prevent building up of sucked-up material in unsuitably formed spots of the channels. 
     The front edge is preferably slightly concave in the horizontal direction and the rear edge is slightly convex in the horizontal direction. This makes it easier for the dust to be sucked into the nozzle and at the front edge there will be less friction against e.g. a skirting-board and you do not risk that the nozzle presses the dust balls against the skirting-board. When pulling the nozzle back against a threshold, it will be easier for dust, gravel, etc., to be sucked in centrally at the rear edge and the friction against the threshold will naturally be lower. 
    
    
     
       BRIEF DESCRIPTION OF THE ENCLOSED DRAWINGS 
       In the following, the invention will be described in greater detail with reference to the preferred embodiments and the enclosed drawings. 
         FIG. 1  is a view of an underside of a preferred embodiment of a bottom plate with a lint pickup, for a vacuum cleaner nozzle according to the invention. 
         FIG. 2  is a view in perspective of the actual bottom plate in  FIG. 1 , without the lint pickups. 
         FIG. 3  is a cross-sectional view along line III-III in  FIG. 1 . 
         FIG. 4  is a view in perspective of the entire vacuum cleaner nozzle. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The vacuum cleaner nozzle in the drawings has a front edge  10 , a rear edge  11  and an underside  12  that is shown in  FIG. 1  and intended to face a not shown floor or some other substructure to be vacuum-cleaned, as well as an upper part in the form of a cover  2  that is provided with a connection  3 ,  6  to connect the nozzle with the vacuum cleaner and that is shown in  FIG. 4  and described in greater detail in connection with the description of that figure. The underside  12  is provided with one front and two rear rest surfaces to support the nozzle on the floor or the like. The front rest surface  13  is positioned centrally along the front edge  10  and the two rear rest surfaces  14  and  15  are positioned separately and symmetrically along the rear edge  11 . 
     According to the invention, the rest surfaces  13 ,  14 ,  15  comprise lint pickups  13 ′,  14 ′,  15 ′ having inclined fibres that project from the rest surfaces  13 ,  14 ,  15 , arranged such that the fibres of the front rest surface  13  incline towards the rear edge while the fibres of the rear rest surfaces  14 ,  15  incline towards the front edge, and such that the nozzle is free from other rest surfaces that might get in contact with a smooth, hard floor. Such a nozzle can be used as an all-round nozzle that is adequately easy to move around on carpets as well as on smooth, hard floors. It has no moving parts whatsoever and it is cheap in production and still it gives the desired cleaning effect in use. 
     The lint pickups  13 ′,  14 ′,  15 ′ can be mounted directly on the rest surfaces  13 ,  14 ,  15 , but suitably they are recessed in pockets  23 ,  24 ,  25  that are formed in the rest surfaces  13 ,  14 ,  15  and are best shown in  FIG. 2 . In that way, adapting between the stiffness of the fibres and their mobility and length projecting from the rest surfaces  13 ,  14 ,  15 , is facilitated. The lint pickups  13 ′,  14 ′,  15 ′ are moreover protected from being scraped off from the rest surfaces  13 ,  14 ,  15 . It is suitable that the lint pickups  13 ′,  14 ′,  15 ′ project a distance in the magnitude of 1 to 2 mm from the rest surfaces  13 ,  14 ,  15 . 
     The front, centrally positioned rest surface  13  and its lint pickup  13 ′ preferably take up about a third of the length of the front edge  10 , while the portions on the side thereof of the front edge  10  form front inlet channels  16 ,  17  for dust loaded air to be sucked into the vacuum cleaner. Furthermore, the two rear, separately positioned rest surfaces  14 ,  15  and their lint pickups  14 ′,  15 ′ similarly take up about one third each of the length of the rear edge  11 , and the portion between them of the rear edge  11  forms a centrally positioned rear inlet channel  18  for dust loaded air to be sucked into the vacuum cleaner. The chosen positioning of the lint pickups with the central, front one  13 ′ at the apex and the two rear ones  14 ′,  15 ′ at the base corners of an equally sided triangle, and the friction between the inclined fibres of the lint pickups  13 ′,  14 ′,  15 ′ and the substructure to be vacuum-cleaned, will make the nozzle self-cleaning. 
     The front inlet channels  16 ,  17  suitably extend somewhat over the front corners  19 ,  20  of the nozzle. Hereby, the vacuum-cleaning of corners between walls or between a wall and furniture, etc., is improved. The rest surfaces  13 ,  14 ,  15  are furthermore advantageously designed such that a rest surface portion  13 ″,  14 ″,  15 ″ that is positioned between a lint pickup  13 ′,  14 ′,  15 ′ and an inlet channel  16 ,  17 ,  18  that passes it, inclines away from the lint pickup  13 ′,  14 ′,  15 ′ in a direction towards the inlet channel  16 ,  17 ,  18 . Thereby, the cleaning ability of the nozzle is improved. 
     The nozzle preferably comprises a bottom plate  1  in which the rest surfaces  13 ,  14 ,  15  and the channels  16 ,  17  are formed, and a top cover  2  connected to the bottom plate, which cover comprises the connection  3 ,  6  for connecting the nozzle to the vacuum-cleaner. The cover  2  and the connection  3 ,  6  is shown in  FIG. 4  and is described in greater detail in connection with the description of that figure. The two front inlet channels  16 ,  17  each lead to a respective hole  21 ,  22  through the bottom plate  1 , such that the dust loaded air is sucked into a room that is defined by the cover  2  and the bottom plate  1 . These holes  21 ,  22  are positioned between respective ends of the central, front rest surface  13  and the respective adjoining rear rest surfaces  14 ,  15  and the bottom plate  1  is designed to split the rear inlet channel  18  in two, such that the two branches  18   a ,  18   b  formed lead to a respective one of the holes  21 ,  22 . The two front channels  16 ,  17  are furthermore advantageously extended such that they extend also beyond their own hole  21  and  22 , respectively, and up to the other hole  22  and  21 , respectively. Hereby, the sucked-in air flows are better balanced. If desired, it is also possible to increase the flow velocity the closer to the holes  21 ,  22  you get, by designing the channels  16 ,  17 ,  18   a ,  18   b  such that their height is gradually decreased from the edges of the nozzle and up to the holes  21 ,  22 . 
     As is best shown in the perspective view of  FIG. 2 , the bottom plate  1  is, suitably at least at one end of each pocket  23 ,  24 ,  25  for the associated lint pickup  13 ′,  14 ′,  15 ′, provided with a recess  23 ′,  24 ′,  25 ′ to facilitate introduction of a tool for loosening and exchanging the lint pickup  13 ′,  14 ′,  15 ′. Thereby, it is possible to change to a lint pickup  13 ′,  14 ′,  15 ′ with other properties, such as for needle-loom carpets or clinker floors that have sharp edges between the slabs. 
     It is also suitable that the sides of the channels  16 ,  17 ,  18   a ,  18   b  are softly rounded in order to minimize the flow resistance and to prevent building up of sucked-up material in unsuitably formed spots of the channels. 
     The front edge  10  is preferably slightly concave in the horizontal direction and the rear edge  11  is slightly convex in the horizontal direction. This makes it easier for the dust to be sucked into the nozzle and at the front edge  10  there will be less friction against e.g. a skirting-board and you do not risk that the nozzle presses the dust balls against the skirting-board. When pulling the nozzle back against a threshold, it will be easier for dust, gravel, etc., to be sucked in centrally at the rear edge  11  and the friction against the threshold will naturally be lower. 
     It is clear from  FIG. 2  that the bottom plate  1  has one front  13  and two rear  14 ,  15  surfaces that are raised and that have one pocket  23 ,  24 ,  25  each for receiving the lint pickups. At the end of each rear pocket  24 ,  25  and at both ends of the front pocket  23 , there is a recess  23 ′,  24 ′,  25 ′ in order by a suitable tool to be able to access between the bottom of the pocket and the lint pickup in order if needed to sever off the latter that e.g. may be glued or fastened by snap action in the pocket. In order to allow for snap mounting, the lint pickup can be attached to a stiff, not shown, carrier. Between the rest surfaces  13 ,  14  and  15 , the inlet channels  16 ,  17 ,  18  lead up to the two suction holes  21  and  22 , and the rear channel  18  is shown to be split by a flow divider in two channels  18   a  and  18   b . The front inlet channels  16 ,  17  extend somewhat over the front corners  19 ,  20  of the nozzle. The rest surfaces  13 ,  14 ,  15  are designed such that a rest surface portion  13 ″,  14 ″,  15 ″ that is positioned between a pocket  23 ,  24 ,  25  and an inlet channel  16 ,  17 ,  18  that passes it, inclines away from the pocket  23 ,  24 ,  25  in a direction towards the inlet channel  16 ,  17 ,  18 . It is furthermore clear that the sides of the channels  16 ,  17 ,  18   a ,  18   b  are softly rounded in order to minimize the flow resistance. 
     It is clear from the cross-section of the bottom plate  1  shown in  FIG. 3  that the lint pickups  13 ′,  15 ′ attached in the pockets  23 ,  25  have inclined fibres that project from the rest surfaces  13 ,  15 , arranged such that the fibres of the front rest surface  13  incline towards the rear edge  11  of the nozzle while the fibres of the rear rest surface  15  incline towards the front edge  10  of the nozzle. Suitably, the projecting portion of the lint pickups  13 ′,  15 ′ has a length in the magnitude of 1 to 2 mm from the rest surfaces  13 ,  15 . The material of the bottom plate  1  can be metal, or if desired, plastics. 
     The upper part  2  of the nozzle, shown in  FIG. 4  and shaped as a cover, is designed as is known per se and is provided with a connection for connecting the nozzle to the vacuum cleaner. The connection comprises a T-piece  3  with a lateral pipe portion  4  and a tube shaped pole portion  5  that projects perpendicularly from the middle of the lateral portion. At its ends, the lateral pipe portion  4  is rotatably mounted in the cover  2 , such that the tube shaped pole portion  5  projects from the cover  2  and can be freely rotated between an essentially horizontal position and an essentially vertical position. One end of an angular pipe  6  is rotatably mounted in the tube shaped pole portion  5 . The other end of the angular pipe  6  is intended to receive a not shown vacuum cleaner pipe or the like, which connects the nozzle with a not shown vacuum cleaner hose. The two rotatable mountings are naturally made not to allow an amount of air through that could otherwise considerable impair the suction ability of the vacuum cleaner. The double rotatable mounting in the connection between the vacuum cleaner pipe and the nozzle gives a considerable freedom of movement that makes it easier for the nozzle to access narrow spots. The dust loaded air sucked into the nozzle passes through the inlet channels  16 ,  17 ,  18   a ,  18   b  and the holes  21  and  22 , to the room defined by the bottom plate  1  and the cover  2 , from which it goes on to the lateral portion  4  and the tube shaped pole portion  5  of the T-piece  3  and leaves the nozzle through the angular pipe  6 , in order to be sucked into the vacuum cleaner via the connected vacuum cleaner pipe and the subsequent hose. The T-piece  3  is preferably streamlined at least internally in the transition between the lateral pipe portion  4  and the tube shaped pole portion  5 , such that each pipe branch has the shape of a pipe bend rather than a pipe elbow. The upper part  2  is united with the bottom plate  1  in a suitable way, such as by gluing.