Patent Publication Number: US-6209925-B1

Title: Turn shaft for a vacuum cleaner

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a vacuum cleaner tube shaft having an upper tube part and a lower tube part that are turnably connected to one another, wherein each tube part has two tube sections that are inclined with respect to one another, the lower tube part has an end section supporting a nozzle that includes a nozzle part and a connecting part, the connecting part being connected to the end section while the upper end of the upper tube part is connected to a hose, a tube handle or the like. 
     Tube shafts of different types are previously known. The simplest tube shafts have one or more hollow, straight sections to which a tube handle with a hose and a nozzle is connected. The hose is further connected to a vacuum source arranged in a vacuum cleaner housing or to a suction port for a so-called central vacuum system. 
     A problem when using such tube shafts is that it is difficult to reach sufficiently far beneath low furniture and other details. Thus, the operator is forced to bend in order to decrease the angle between the tube shaft and the floor surface. This is, of course, uncomfortable and cumbersome. 
     In order to reduce this problem it has previously been suggested, see WO 89/07412, to use a flexible hose between two sections of the tube shaft, with a lower section of the tube shaft being adjustable to a position parallel to the floor surface. However, this arrangement is very primitive and it is difficult to operate the tube shaft in its normal position because of the flexibility of the hose. 
     A similar arrangement, but with additional elements to stabilize the two sections with respect to one another is also previously known, see SE 9600650. This arrangement is, however, very complicated because the existence of several ball joints, telescopically arranged components, and additional tube sections. 
     It is also previously known, see JP 725653, to manufacture the complete tube shaft, or a portion thereof, is made from flexible material, which means that the tube shaft is bent under the influence of the contact forces with the furniture. Even if such a design is appealing in the abstract, it is difficult to find material compositions that simultaneously provide the necessary flexibility and stability during normal use. 
     Moreover, U.S. Pat. No. 1,012,195 and U.S. Pat. No. 1,104,148 describe other types of arrangements for facilitating cleaning operations below furniture. U.S. Pat. No. 1,012,195 describes a tube shaft comprising two parts, a lower straight part and an upper handle part having a short air inlet section which is inclined with respect to an elongated air outlet section. When cleaning below furniture the upper part is turned 180°. This, however, means that the handle part has to be moved to a position near the floor which is as uncomfortable as when using ordinary tube shafts. U.S. Pat. No. 1,104,148 describes an arrangement having a bent tube shaft that can be turned 90° at each side of a central upraised position. However, when turning the tube shaft to one of its side positions the operator is forced to move the handle part towards the floor in order to reach under furniture. Consequently this arrangement has the same disadvantages as the arrangement described in U.S. Pat. No. 1,012,195. 
     SUMMARY OF THE INVENTION 
     The present invention is directed toward a simple and cheap arrangement making it possible to adjust the tube shaft between a normal position and a position in which cleaning below low furniture is facilitated. The present invention is further directed toward such an arrangement wherein the stability of the tube shaft is not reduced by the existence of a flexible element or a flexible material. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and further features of the present invention will be apparent with reference to the following description and drawings, wherein: 
     FIG. 1 schematically shows a side view of a vacuum cleaner being equipped with a tube shaft according to the invention; 
     FIG. 2 a  shows, in an enlarged scale, the tube shaft in a first normal position; 
     FIG. 2 b  shows, in an enlarged scale, the tube shaft in a second position to be used when cleaning below low surfaces; and, 
     FIG. 3 shows a section through the tube shaft at the connection between the parts of the tube shaft. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a vacuum cleaner having a tube shaft  10  which, via a tube handle  11  and a hose  12 , is connected to a vacuum cleaner housing  13 . The vacuum cleaner housing  13 , in a traditional way, encloses an electrically driven fan unit (not shown) and a dust container (not shown) in which the dust is collected. Alternatively, the hose  12  can be connected to an outlet port of a central vacuum cleaner system. 
     The lower end of the tube shaft  10  supports a conventional nozzle  14  having a nozzle part  14   a  to which a connecting part  14   b  is turnably and tiltably secured. The tube shaft  10  comprises an upper tube part  15  and a lower tube part  16  both being made of stiff material, such as hard plastic or aluminum. 
     The upper tube part  15  comprises a first bent segment  15   a  and an oppositely-directed second bent segment  15   b . The first and second bent segments  15   a ,  15   b  separate three mainly straight sections that are inclined with respect to one another, the mainly straight sections being an upper section  15   c , a middle section  15   d , and a lower section  15   e . The upper section  15   c  is, at its upper end, provided with a sleeve  15   f  in which the tube handle  11  in a traditional way is inserted and secured. 
     The lower tube part  16  comprises a bent segment  16   a  separating two straight sections, a lower end section  16   b  and an upper section  16   c , which are inclined with respect to one another. The upper section  16   c  is provided with a sleeve  16   d  in which the lower section  15   e  of the upper tube part  15  can be inserted and locked by means of a locking mechanism. 
     With reference to FIG. 3, the locking mechanism includes a rocker arm  18  turnably or pivotally secured in a holder  19  that is fixed to the sleeve  16   d . The rocker arm  18  has an extending part or finger  20  extending through an opening  21  in the sleeve  16   d  as well as through one of two diametrically opposed openings  22  formed in the lower section  15   e  of the upper tube part  15 . The outer portion or surface of the extending part  20  is slanted and the rocker arm is under the influence of a spring  23  that biases the extending part  20  toward the opening  21  in the sleeve  16   d.    
     Accordingly, as the lower section  15   e  of the upper tube part  15  is axially inserted into the sleeve  16   d , the rocker arm  18  pivots against the spring bias and the slanted surface of the extending part  20  of the rocker arm  18  slides along the outer surface of the lower section  15   e . When the lower section  15   e  is completely inserted into the sleeve  16   d , the rocker arm  18  pivots, due to the spring bias, such that the extending part  20  is inserted through the opening  22  in the lower section  15   e  and snap-locks the upper tube part  15  to the lower tube part  16 . It is contemplated that an identical locking arrangement be used between the nozzle connecting part  14   b  and the lower tube part end section  16   b.    
     Also, with the above-described locking mechanism, the tube parts  15 ,  16  can be easily reconfigured from a first position (FIG. 2 a ) to a second position (FIG. 2 b ) by simply disengaging the locking mechanism from one of the openings  22 , rotating the lower tube part  16 , and re-engaging the locking mechanism with the other of the openings  22 . 
     Thus, the arrangement is designed such that the lower tube part  16 , with its end section  16   b , can be turned 180° about a central axis extending in the length direction of the end section  16   b , and the connecting part  14   b  together with the tube shaft  10  can be tilted about a horizontal axis which is perpendicular to the central axis. 
     The device according to the present invention operates and is used in the following manner. During normal vacuum cleaning operation (FIG. 2 a ), the upper tube part  15  is inserted into and is locked in the lower tube part  16  such that the upper section  15   c  is mainly in line with the end section  16   b  at a first angle a with respect to the floor. The nozzle  14  is, by means of the connecting part  14   b , secured to the end section  16   b . Vacuum cleaning operation can now be undertaken in a traditional way. 
     In order to adjust the arrangement for cleaning under furniture (FIG. 2 b ), the rocker arm  18  is depressed to release the locking mechanism and permit the tube parts  15 ,  16  to be turned relative to one another about a common axis of the two tube sections  15   e  and  16   c . When the lower tube part  16  has been turned about 180° with respect to the upper tube part  15 , these parts  15 ,  16  are fixed to one another because the extending part  20  of the rocker arm  18  snaps into the other of the openings  22 . Then the nozzle part  14   a  is likewise turned 180° with respect to the end section  16   b . This means that the end section  16   b  forms a second angle β with respect to the floor, wherein the second angle β is less than the first angle α. Because of the new configuration of the tube shaft it is now possible to move the nozzle  14  under low furniture generally without lowering the tube handle  11 . It is noted that the upper section  15   c  generally remains at the convenient first angle a with respect to the floor. 
     It should be mentioned that it of course is possible to use several tube parts to vary the shape of the tube shaft in a suitable manner in order to get the intended result as well as to use different types of locking arrangements between the tube parts and/or the nozzle. 
     While the preferred embodiment of the present invention is shown and described herein, it is to be understood that the same is not so limited but shall cover and include any and all modifications thereof which fall within the purview of the invention.