Patent Publication Number: US-2019167057-A1

Title: Vacuum-cleaner suction tube

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention concerns a vacuum cleaner suction tube with at least one inner tube, with at least one outer tube, with at least one actuating mechanism and with at least one end sleeve inserted into the outer tube. The end sleeve is located between the inner tube and the outer tube and has at least one end sleeve recess. The outer tube has at least one outer tube recess and the inner tube has a plurality of snap-in depressions. The actuating mechanism passes through the outer tube recess, wherein the actuating mechanism comprises a base plate having at least one snap-in recess, wherein the actuating mechanism comprises at least one locking device, wherein the locking device is movable from a locking position into at least one unlocking position. In the locking position, the locking device passes through the end sleeve recess in the direction of the inner tube, wherein the locking device is engaged with at least one snap-in depression on the inner tube in the locking position, and, in the unlocking position, a shifting of the inner tube relative to the outer tube is enabled by the locking device. 
     Description of Related Art 
     Vacuum cleaner suction tubes are known from the prior art in a variety of designs. Telescopic vacuum cleaner tubes offer the advantage that they can be adapted to the body size of a user or to different application situations during use for short or long distances by changing the length, on the one hand to enable ergonomic operation and on the other hand to ensure a multi-functional application of the vacuum cleaner for different vacuuming tasks. 
     To achieve telescoping capability, such vacuum cleaner suction tubes usually comprise a plurality of tube segments which are arranged one behind the other and inserted into one another so that they can be telescoped relative to one another by axially shifting the tube segments. To change the length of the vacuum cleaner suction tube, the user manually moves the tube segments, i.e. pushes them axially into each other or on top of each other. Various snap-in mechanisms are known for locking a certain position of the tube segments, which reliably prevent unwanted relative movement of the tube segments during use of the vacuum cleaner suction tube. Recesses in the walls of the tube segments are often used, which interact with corresponding blocking elements on the other tube segments. 
     In addition, vacuum cleaner suction tubes are often made of stainless steel, with add-on elements, for example, of plastic, attached at least in the two end areas of a vacuum cleaner suction tube. The attachment elements are advantageously pushed onto the vacuum cleaner suction tube or inserted into the vacuum cleaner suction tube. A special requirement is the leak-free sealing between the vacuum cleaner suction tube and the attachment element. 
     Prior art vacuum cleaner suction tubes often have the disadvantage that reliable sealing between the vacuum cleaner suction tube and the attachment element cannot be sufficiently ensured, especially when certain plastics are used for the attachment elements. 
     Based on the above prior art, the object of the invention is to provide a vacuum cleaner suction tube and a method for manufacturing a vacuum cleaner suction tube which enables a reliable and leak-free connection with an attachment element when using any type of plastic for the attachment element. 
     SUMMARY OF THE INVENTION 
     The aforementioned object is initially and essentially achieved by a vacuum cleaner suction tube according to the invention in that an axial shifting of the end sleeve relative to the outer tube is blocked by the actuating mechanism and that an inwardly directed radial movement of the actuating mechanism relative to the outer tube is blocked by the inner tube. In this manner, the individual components of the vacuum cleaner suction tube fix themselves mutually. It is not necessary that separate openings are formed on the outer tube to fix the end sleeve, as this is blocked in movement by the actuating mechanism. One advantage of the invention is therefore that the sealing-ability of the vacuum cleaner suction tube is increased, since only the most necessary openings are formed on the outer tube, preferably made of stainless steel. 
     In order to further improve the fixing of the individual components, one design of the vacuum cleaner suction tube provides that an outwardly directed radial movement of the actuating mechanism relative to the outer tube is blocked by the outer tube. Conversely, an outwardly directed radial movement of the actuating mechanism relative to the outer tube is blocked by the actuating mechanism or by the base plate. The base plate is dimensioned in such a way that the actuating mechanism passes through the recess in the outer tube in an outward direction, but the base plate remains inside the outer tube and strikes the wall of the outer tube. It is therefore not possible to push or pull the actuating mechanism out of the outer tube in the radial direction. 
     The actuating mechanism can lock the end sleeve in position in various ways. In one design of the vacuum cleaner suction tube, it is provided that the end sleeve recess has approximately the same size as the dimensions of the base plate, so that the base plate engages positively into the end sleeve recess. The thickness of the base plate, i.e., the extension of the base plate in the radial direction, corresponds approximately to the thickness of the end sleeve. The base plate can therefore be lowered into the end sleeve recess so that the base plate is aligned with the end sleeve when viewed in the axial direction, i.e. the base plate does not project beyond the edge of the end sleeve facing the inner tube. The end sleeve can be inserted into the outer tube during production of the vacuum cleaner suction tube, wherein the actuating mechanism is already located in the outer tube. The end sleeve is inserted into the outer tube until the corresponding elements, i.e. the base plate of the actuating mechanism and the end sleeve recess, engage with one another. If the end sleeve receives an impulse of movement in this position, the contours of the end sleeve recess hit the base plate and movement is prevented. The thicker the material of the end sleeve, the deeper the end sleeve recess can be. Consequently, the area with which the end sleeve is supported on the base plate of the actuating mechanism via the end sleeve recess is also increased, insofar as the material thickness of the base plate, i.e. the height of the base plate, corresponds to the material thickness of the end sleeve. However, with increasing material thickness, the installation effort of the vacuum cleaner suction tube increases, since the end sleeve must be guided past the base plate during insertion before the base plate can engage into the end sleeve recess. The skilled person must therefore be careful to find a compromise between material thickness and simple installation. 
     The end sleeve recess does not necessarily have to depict a complete recess. One possibility of design is, for example, a depression into which the base plate can engage, wherein recesses can be formed in the depression so that only the elements of the locking device pass through the end sleeve recess, which contribute to a locking of the vacuum cleaner suction tube. 
     Alternatively, it is provided in one design of the vacuum cleaner suction tube that the actuating mechanism is frictionally connected to the end sleeve so that axial movement of the end sleeve relative to the outer tube is blocked. In this manner, the end sleeve is simply inserted into the outer tube, wherein the actuating mechanism or the base plate of the actuating mechanism exerts sufficient friction on the end sleeve so that the end sleeve can no longer be easily removed from the outer tube. In this configuration, the size and design of the end sleeve recess is irrelevant as long as it ensures that, in the locking position, the locking device can pass through the end sleeve recess towards the inner tube, so that, in the locking position, the locking device engages with at least one snap-in depression on the inner tube and a movement of outer tube and inner tube relative to one another is blocked. 
     One advantageous design provides that the end sleeve has elongated crosspieces which act as spacers from outer tube to end sleeve, wherein the end sleeve is then only connected to the outer tube via the crosspieces. In this manner, for example, the material thickness of the base plate or the actuating mechanism can be selected independently of the end sleeve. If the base plate is relatively thick, it may not be possible to insert the end sleeve without damage. The design of the elongated crosspieces, whose arrangement can be selected so that the base plate is arranged at a distance of two crosspieces, can be selected so that the end sleeve can still be inserted into the outer tube, but the friction between end sleeve and base plate is so great that removal of the end sleeve is not easily possible. The arrangement and number of crosspieces can be more or less freely chosen. A recess or material removal in the end sleeve at the point where the actuating mechanism is connected to the end sleeve is also conceivable, so that there are no crosspieces at all, but the end sleeve only has a slightly smaller material thickness in the area where the end sleeve comes into contact with the base plate. 
     For easier installation of the end sleeve, a further design of the vacuum cleaner suction tube provides that the end sleeve has an insertion end and an outer end and that the insertion end is conical in at least one region. The region in which the insertion end is conical should be approximately as large as the width of the base plate. The end sleeve can thus be inserted more easily into the outer tube, since the friction between the base plate and end sleeve is not too high due to the tapered area. The sleeve can thus be easily inserted into the outer tube until it reaches its desired position, for example until the end sleeve recess and base plate engage. 
     To prevent the end sleeve from being inserted too far into the outer tube, a further advantageous design of the vacuum cleaner suction tube provides for at least one stop at the outer end. The stop can cover only a small area or several small areas of the outer end. 
     In a further advantageous design, however, it is provided that the stop is formed by an enlargement in the outer diameter of the end sleeve. The stop is therefore designed circumferentially. For example, the stop can be designed in such a manner that the material is curved in the region of the enlarged outer diameter by a channel directed towards the insertion end. The end sleeve thus does not only strike at the end of the outer tube, but surrounds the end of the outer tube. Since the outer tube is usually made of stainless steel or another metal, the ends of the outer tube can be sharp-edged. The channel shape of the stop encloses the sharp edge so that the risk of injury is minimized. The material in the region of the enlarged outer diameter does not have to be the same material as the rest of the end sleeve. A foam or rubber compound can additionally increase the sealing-ability at the end of the tube and accordingly also further reduce the risk of injury, as the material is softer than conventional plastics. 
     In a further advantageous design of the vacuum cleaner suction tube according to the invention, it is provided that the outer tube has exactly one outer tube recess. One of the advantages of the vacuum cleaner suction tube according to the invention is that the end sleeve is not attached separately to the outer tube, but is held in the outer tube by the interaction of the individual components. To improve the pressure loss and flow characteristics of a vacuum cleaner suction tube, as few openings as possible in the outer tube are advantageous. With the vacuum cleaner suction tube according to the invention, only one recess is necessary as long as no further components have to be attached to the outer tube. With only one recess, however, the locking device can interact with the inner tube, on the one hand, and the components can be securely connected to one another on the other hand. 
     In order to further improve the interaction of the individual components, a further design of the vacuum cleaner suction tube provides that the inner tube comprises at least one longitudinal groove and that at least one tongue corresponding to the longitudinal groove is formed on the end sleeve so that the inner tube is guided by the end sleeve in the outer tube. To ensure that the locking device can always engage in the corresponding snap-in depressions of the inner tube, it is advantageous to prevent the inner tube from rotating. This can be easily achieved by a tongue and groove design on the inner tube and end sleeve. For example, the groove can also be formed inside the end sleeve, wherein a corresponding tongue is provided on the inner tube. 
     Alternatively, it can be provided in a further design that the inner tube comprises at least one longitudinal groove and that at least one tongue corresponding to the longitudinal groove is formed on the outer tube so that the inner tube is guided from within the outer tube. Also with this design, the longitudinal groove can be formed, for example, inside the outer tube, wherein the corresponding tongue is formed on the inner tube. The groove on the outer tube, for example, can be implemented by deformation of the tube or by two folds in the outer tube, so that a V-shaped groove is created in the outer tube. 
     The invention also relates to a method for manufacturing a vacuum cleaner suction tube, with at least one inner tube, with at least one outer tube, with at least one actuating mechanism and with at least one end sleeve, wherein the end sleeve has at least one end sleeve recess, wherein the outer tube has at least one outer tube recess, wherein the inner tube has a plurality of snap-in depressions and wherein the actuating mechanism has a base plate having at least one snap-in recess. 
     The object described at the outset is essentially achieved by the method in that the actuating mechanism is led from the inside of the outer tube through the outer tube recess, that the end sleeve is inserted into the outer tube and is blocked in axial movement by the actuating mechanism, and that the inner tube is inserted into the end sleeve and the actuating mechanism is blocked in radial movement by the inner tube. A logical sequence for assembling the vacuum cleaner suction tube is divided into the following steps: inserting the actuation mechanism into the outer tube, inserting the end sleeve into the outer tube and locking the end sleeve using the actuation mechanism and finally inserting the inner tube. To ensure a secure connection of the elements of the vacuum cleaner suction tube, no further elements are necessary, as the individual components hold one another. 
     In detail, there is a plurality of possibilities for designing and further developing the vacuum cleaner suction tube and the method for manufacturing a vacuum cleaner suction tube as will be apparent from the following description of preferred embodiments in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic representation of an assembled vacuum cleaner suction tube, 
         FIG. 2  is a perspective view of a part of an actuating mechanism, 
         FIG. 3  is an embodiment of an end sleeve in a perspective view, 
         FIG. 4  is the embodiment according to  FIG. 3  with an inserted part of the embodiment of the actuating mechanism according to  FIG. 2 , 
         FIG. 5  is a sectional view of an embodiment of the vacuum cleaner suction tube, and 
         FIGS. 6 a  to 6 c    are schematic representations of the inventive method for manufacturing a vacuum cleaner suction tube. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a schematic representation of an embodiment of a vacuum cleaner suction tube  1 . The vacuum cleaner suction tube  1  has an inner tube  2 , an outer tube  3 , an actuating mechanism  4  and an end sleeve  5 . An end sleeve recess  6  is formed in the end sleeve  5  and an outer tube recess  7  is formed in the outer tube  3 . The inner tube  2  has snap-in depressions  8  which allow the actuating mechanism  4  to engage in the snap-in depressions  8  by means of a locking device in order to block the relative displacement of inner tube  2  and outer tube  3  to one another. The actuating mechanism  4  has a base plate  10  with two snap-in recesses  9  (not shown in  FIG. 1 ) located inside the outer tube  3 , wherein the remainder of the actuating mechanism  4  passes through the outer tube recess  7 . The end sleeve  5  is inserted with its insertion end  11  into the outer tube  3  in such a manner that only its outer end  12  emerges from the outer tube  3 . To prevent the end sleeve  5  from being inserted too far into the outer tube  3 , a stop  13  is provided at the outer end  12  of the end sleeve  5 , which is formed by an enlargement of the outer diameter D of the end sleeve. 
     The individual components interact in such a manner that they fix one another. The base plate  10  of the actuating mechanism is dimensioned so that it is larger than the outer tube recess  7 , so that the actuating mechanism  4  cannot be pushed out of the outer tube  3  through the outer tube recess  7  from the inside. The end sleeve recess  6  of the end sleeve  5  interacts with the base plate  10  of the actuating mechanism  4 , so that an axial displacement of the end sleeve  5  is blocked by the actuating mechanism  4 . Finally, the inner tube  2  prevents the actuating mechanism  4  from being pushed into the outer tube  3  in the radial direction. All components therefore hold one another. 
       FIG. 2  shows the base body  14  of the actuation mechanism  4 , comprising the base plate  10  and a mount  15  for the locking device of the actuating mechanism  4 . Two snap-in recesses  9  are formed in the base plate  10 , through which the locking device (not shown here) can pass to engage the snap-in depressions  8  of the inner tube  2 . The base plate is adapted to the shape of the tube so that the base plate has an arch  16 . 
       FIG. 3  shows an embodiment of an end sleeve  5 . Crosspieces  18  are formed on the inside  17  of the end sleeve  5 , which serve to stabilize the end sleeve  5 . In addition, they reduce the bearing surface of the inserted inner tube  2  in the end sleeve  5 , which additionally reduces friction. This makes it easier to move the inner tube  2  within the end sleeve  5 . The movement in the outer tube  3  is correspondingly smoother, since the inner diameter of the end sleeve  5  is smaller than the inner diameter of the outer tube  3  For the guidance of the inner tube  2  (not shown here), a tongue  19  is formed on the inside  17  of the end sleeve  5 , which corresponds with a groove formed on the inner tube  2 . The tongue  19  is arranged opposite the end sleeve recess  6 . 
     In this embodiment, the end sleeve recess  6  is only a recess in the material of the end sleeve  5  In addition, two smaller recesses  20  are formed in the end sleeve recess. The two recesses  20  correspond to the two snap-in recesses  9  in the base plate  10 . A tapering cone-shaped region  21  is formed at the insertion end  11 , which begins at the end sleeve recess  6  and ends at the end of the end sleeve  5  at the insertion end  11 . The cone-shaped region  21  is used to simplify the insertion of the end sleeve  5  into the outer tube  3  when the actuating mechanism  4  is already arranged in the outer tube  3 . The actuating mechanism  4  can slide onto the cone-shaped region  21  during insertion and does not already block the path of the end sleeve  5  during insertion. In this embodiment, the stop  13  is turned towards the insertion end  11 . In this manner, the stop  13  encloses the end of the outer tube  3  (not shown here) when the end sleeve  5  is completely inserted into the outer tube  3 . 
       FIG. 4  shows the base body  14  of the actuating mechanism according to  FIG. 2  which is inserted into the end sleeve recess  6  of the end sleeve  5  according to  FIG. 3 . In  FIG. 4 , it is easy to see that the end sleeve recess  6  is designed to fit exactly onto the base plate  10 . Conversely, it becomes clear that the end sleeve  5  has no room for movement in the outer tube  3  (not shown here) when the actuating mechanism  4  is already arranged in the outer tube  3 . Because the end sleeve recess  6  is only a depression with two recesses  20 , both the inward radial movement of the actuating mechanism  4  and the outward radial movement of the actuating mechanism  4  are blocked, provided that actuating mechanism  4  and end sleeve  5  are arranged in their position in the outer tube  3 .  FIG. 4  also shows that the cone-shaped region  21  simplifies the insertion of the end sleeve  5  into the outer tube  3 . The cone-shaped region  21  serves as a ramp for the actuating mechanism  4 . As the height increases, friction increases and moving the end sleeve  5  further into the outer tube  3  becomes more difficult. Without the cone-shaped region  21 , it is only possible to move the end sleeve  5  past the actuating mechanism  4  to a limited extent. 
       FIG. 5  shows a sectional view of a vacuum cleaner suction tube  1  in which all components, i.e. inner tube  2 , outer tube  3 , actuating mechanism  4  and end sleeve  5  are connected to one another. In this embodiment, the outer diameter of the area of the inner tube  2  that is not intended to be inserted into the outer tube  3  is increased. This way a simple stop  22  is implemented. Likewise, both the outer and inner diameters of the outer tube  3  are enlarged in one section  23 . The end sleeve  5  is arranged in this section  23 . In the further course of the outer tube  3 , the inner and outer diameters are slightly smaller than in section  23 , so that too great of a distance does not occur between inner tube  2  and outer tube  3 , which could lead to unfavorable flow characteristics during the suction process. 
     Finally,  FIGS. 6 a  to 6 b    show a schematic representation of a method for manufacturing a vacuum cleaner suction tube  1 . In  FIG. 6 a   , the actuating mechanism  4  is inserted into the outer tube  3  and lead through the outer tube recess  7 . Due to the larger base plate  10 , the actuating mechanism  4  cannot be pushed out of the outer tube  3  from the inside. 
     In  FIG. 6 b   , the end sleeve  5  is inserted into the outer tube  3 , wherein the actuating mechanism  4  is already arranged in the outer tube. The end sleeve  5  must be guided past the base plate  10  of the actuating mechanism  4  during insertion. The only possibility for the end sleeve  5  to be guided past the base plate  10  is a slight elastic deformation, which is strongly exaggerated in  FIG. 6 b   . The end sleeve  5  is inserted into the outer tube  3  until the base plate  10  engages into the end sleeve recess  6 . 
       FIG. 6 c    shows how the end sleeve  5  is already completely arranged in the outer tube  3 . The actuating mechanism  4  prevents further movement of the end sleeve  5  into and out of the outer tube  3 , in addition, the stop  13  blocks further movement into the outer tube  3 , and finally the inner tube  2  is inserted into the end sleeve  5  and also the outer tube  3 . The inner tube  2  prevents the actuating mechanism  4  from being pushed or pulled inwards into the outer tube  3 . The individual components fix one another after completion of the method.