EP1806088B1 - Telescopic suction pipe for a suction cleaner with a latching element in the form of a bow spring - Google Patents

Abstract

The inner tube (3) of a telescopically extending suction hose is provided with indentations (7) spaced in line along the length with a rotation prevention groove (16) and the outer tube (2) has a sleeve (4) with an operating button (5) by which a circumferential spring (15) is depressed to release an engagement with one of the indents to adjust the tube length.

Description

The invention relates to a telescopic vacuum cleaner suction tube with an outer tube, an inner telescoping inner tube with locking recesses, a rotation and a locking device with a locking element which is disengaged from him about diametrically opposed actuator from the detent recess, wherein the locking means of at least one of the inner tube a form-fitting encompassing bow spring is made, which engages under bias of a spring, the locking element in a telescoping in the nearest locking recess of the inner tube again.

1. a) eine Bügelfeder als Druckübertragungselement, die selbst keine Federwirkung ausübt
2. b) und eine Blattfeder, die unter einer Vorspannung stets das Rastelement in eine der Rastvertiefungen des Innenrohres einzudrücken sucht.

Such a telescopic vacuum cleaner suction tube is from the DE 39 29 399 A1 known. In it, the bow spring engages with their mutually facing ends in recesses of the actuating element. The bow spring acts when depressing the actuating element only as a dimensionally stable pressure transmission element, from which an actuating element opposite latching element is disengaged from the detent recess of the inner tube. This locking element consists of a flattened, the bow spring at its the actuating element diametrically opposite area. In order to engage the locking element again in a locking recess, the locking element is under constant action of a prestressed leaf spring, which always presses the locking element in the direction of the locking recesses on the surface of the inner tube. In this mode of operation always two springs are required, namely

1. a) a bow spring as a pressure transmission element, which exerts no spring action itself
2. b) and a leaf spring, which always seeks to press the locking element in one of the locking recesses of the inner tube under a bias.

The bow spring has an annular and the detent recess a part-circular cross-section. In jerky, exerted on the ends of the outer and / or inner tube compressive forces, the locking element against the force of the leaf spring from the locking recess as on an inclined plane slide up and disengage and thus carried out an undesirable telescopic adjustment. The locking element again pressing into the detent recess leaf spring not only increases the manufacturing and assembly costs, but also requires a sleeve-like handle to the outer and inner tube to accommodate the leaf spring secured, which not only increases the assembly but also the manufacturing cost ,

Based on this state of the art, the invention has for its object to provide a telescopic vacuum cleaner suction pipe of the type mentioned, which not only significantly reduces the manufacturing and assembly costs of locking technology, but also always a safe, shock-like pressure loads resistant locking at easy ergonomic handling guaranteed.

This object is achieved in conjunction with the generic term mentioned in the present invention that the bow spring consists of an annular spring with a rectangular or circular cross-section, which alternatively surrounds the inner tube or a guide sleeve or the outer tube not only form fit, but also non-positively and the free ends of the actuating element to disengage the lock are auseinanderzuspreizen, whereby the locking element lifted out of the detent recess is.

• a) die Vorspannung der Bügelfeder läßt stets das mit ihr einteilig verbundene Rastelement automatisch unter ihrer Vorspannung in die jeweils nächstgelegene Rastvertiefung einrücken. Eine zweite Feder ist entbehrlich.
• b) Beim Auseinanderspreizen der Enden der Bügelfeder wird unter Erhöhung ihrer Vorspannung das Rastelement aus der Rastvertiefung herausgehoben, weil beim Niederdrücken des Betätigungselementes und dem dadurch bedingten Aufspreizen der Federenden, das Rastelement seine Position verändert und aus der Rastvertiefung ausrückt.
• c) das Betätigungselement kann als Druckknopf oder als Schieber oder als Schieberhülse ausgebildet werden und wird von der Vorspannung der Bügelfeder stets in seine unbelastete Ausgangsposition verschoben, wodurch eine zusätzliche separate Rückholfeder nicht erforderlich ist.

This embodiment always requires only one spring, which has to fulfill several functions at the same time, namely

• a) the bias of the bow spring can always engage with its integrally connected detent element automatically under their bias in the nearest detent recess. A second spring is dispensable.
• b) When spreading the ends of the bow spring the catch element is lifted out of the detent recess increasing its bias, because when depressing the actuating element and the consequent spreading of the spring ends, the locking element changes its position and disengages from the detent recess.
• c) the actuating element can be designed as a push button or as a slider or as a sliding sleeve and is always moved by the bias of the bow spring in its unloaded starting position, whereby an additional separate return spring is not required.

This solution is the first time in aversion from the entire state of the art for the movement mechanism of a locking a positive and non-positively acting bow spring exploited by spreading their ends to release the lock and its bias for automatic locking.

Especially with a bow spring with rectangular cross-section their corresponding geometrically similar adapted flat embossed locking recesses on the inner tube are so minimal that the flow cross-section and thus the flow resistance within the inner tube over the prior art with semicircular detent recesses is significantly reduced. The flow resistance is determined essentially by the known and also required rotation. Overall, the lock consists of only two parts, namely a bow spring and an actuator in the form of a push button or a slider, which reduces the manufacturing and assembly costs accordingly.

Surprisingly, when spreading the free ends of the bow spring by the actuator, the approximately diametrically opposed locking element lifted out of the detent recess, which was not to be expected at a spread on the opposite area. For this reason, a person skilled in the art would not have dared to do such a function of the locking device until the filing date. Nevertheless, it has surprisingly been found that with the existing only from the bow spring and the actuator locking device always secure locking as well a rapid release of the lock to initiate the telescoping process is guaranteed.

According to an advantageous embodiment of the invention, the free ends of the bow spring in the vicinity of the actuating element funnel-shaped either one or bent outwards to ensure a always low-friction and trouble-free engagement with the actuator.

According to a first embodiment, the locking recesses in the inner tube have a flat rectangular shape, which cooperate positively with a cross-sectionally rectangular bow spring.

According to a first embodiment, the actuating element is designed as a push button, which engages with its bow spring facing provided with a cone or wedge-shaped end in the space between the funnel-shaped inwardly or outwardly bent ends of the bow spring and under a bias of the bow spring in its locking position in a raised position is raised within a surrounding housing. Thus, the bow spring over the push button also fulfills the function of a return spring in its initial position and at the same time with their non-positive and positive gripping the inner tube secure engagement of their locking element in the respective locking recess under the same spring preload.

To release the lock, the push button with its conical face in the space between the funnel-shaped inwardly or outwardly bent ends of the bow spring pressed down in the direction of the surface of the inner tube with simultaneous spreading apart of the bow spring, whereby the bow spring disengages with its diametrically opposed locking element from the detent recess of the inner tube and thus inserted the inner tube either in the outer tube or in the outer tube it can be pulled out.

According to a second advantageous embodiment of the invention, the actuating element consists of a slide arranged on the outer tube, which is movable parallel to the direction of the longitudinal axis of symmetry. This slider has two pairs of conical surfaces applied to the run-up edges formed by the bent ends of the bow spring, which are connected to each other at their opposite tip areas hourglass-shaped and thus spread the bow spring parallel to the longitudinal axis of symmetry of the tubes upon movement of the slide. This can ergonomically favorable manner, z. B. pulled when pulling the telescopic tubes of the slide in the direction of the handle and pressed when telescoping the tubes in the direction of the nozzle part, whereby a coordinated with the telescoping operation of the slide in one or the other direction runs.

The conical surfaces extend advantageously to a plane passing through the longitudinal axis of symmetry at an angle α between 30 ° and 60 °, advantageously at an angle α of 45 ° and are formed as a flat conical surfaces of a quadrangular pyramid.

According to a further embodiment, the conical surfaces can also consist of partial circumferential surfaces of two straight circular cones. In this case, the contact surface at the leading edges of the bow spring from two generatrices of each circular cone, which is associated with a low-friction spreading of the ends of the bow spring.

According to an advantageous embodiment of the invention, the actuating element is arranged both in the form of the push button and in the form of a slide together with a still to be discussed guide sleeve on an extended, the inner tube end facing the outer tube. As a result, despite the installation of the guide sleeve and the actuating element of the flow cross section at the end of the outer tube is fully maintained, the guide sleeve can serve in a known manner both for holding the actuating element and for sealing the gap between the inner and outer tube.

According to a further particularly advantageous embodiment of the invention, the slide is provided at its, the free outwardly bent ends of the bow spring facing surface area with guide grooves in which these ends of the bow spring out and when moving in one of the two directions parallel to the longitudinal axis of symmetry of the tubes to open the Locking device are spread apart.

When using a bow spring with a circular cross-section according to the prior art, using a slider as an actuating element, this is advantageously designed as a sleeve tube completely encompassing the outer tube, which at its The detent element nearest inner surface has a securing projection which engages in the locking position exactly in its central region of the locking element. By this securing projection ensures that in jerky pulses on one end or both ends of the tubes - unlike the prior art - an undesirable telescoping is not possible. Only when the slide shifts when moving in one of the two possible directions in the central region of the securing projection relative to the locking element, the locking element can disengage from the detent recess. Otherwise this is prevented by the securing projection.

To ensure a short switching path and thus a rapid disengagement of the securing projection of this is rounded in the direction of the locking element or provided with conical side surfaces.

In the formation of the slide with guide grooves for spreading the ends of the bow spring the cam tracks of these guide grooves are adapted to the geometry of the securing projection, that only after a short, straight displacement within a straight portion of the curved path of the spreading of the ends of the bow spring can begin. This clear curve guide a possible jamming of the locking projection with the locking element when opening the lock is excluded.

The bow spring is advantageously made of spring steel and is spreadable on a circumferential groove of a guide sleeve positively and non-positively disposed, which at the end of the outer tube in a space between the inner and outer tube is arranged stationary. At two diametrically opposite areas, the bow spring openings, through one of which grip the ends of the bow spring and the other by the locking element.

The rotation is in a conventional manner from a parallel to the longitudinal axis of symmetry extending longitudinal groove, in which a projection of the guide sleeve engages positively. In order to use in the production of the inner tube only a stamping tool in only one stamping process, the longitudinal groove is arranged in the region of the locking recesses in the inner tube.

• Fig. 1 einen Längsschnitt durch ein teleskopierbares Staubsauger-Saugrohr mit einem als Druckknopf ausgebildeten Betätigungselement und einer im Querschnitt rechteckigen Bügelfeder,
• Fig. 2 die Ansicht des Längsquerschnittes im Bereich des Druckknopfes in gegenüber Fig. 1 vergrößerter Darstellung in Verriegelungsstellung,
• Fig. 2a die Teilansicht auf die Rastvertiefungen und die Nut zur Verdrehsicherung in Richtung des Pfeiles IIa von Fig. 2,
• Fig. 3 die Ansicht von Fig. 2 in der entriegelten Position der Bügelfeder mit aus der Rastvertiefung herausgehobenem Rastelement,
• Fig. 4 Schnittansicht entlang der Linie IV/IV von Fig. 2,
• Fig. 5 Schnittansicht entlang der Linie V/V von Fig. 3,
• Fig. 6 die Ansicht der Bügelfeder gemäß den Fig. 1 bis 5,
• Fig. 7 die Draufsicht auf die Bügelfeder in Richtung des Pfeiles VII von Fig. 6,
• Fig. 8 die Unteransicht der Bügelfeder in Richtung des Pfeiles VIII von Fig. 6,
• Fig. 9 eine der Ansicht von Fig. 2 entsprechende Teilansicht des Längsquerschnittes im Bereich eines als Schieber ausgebildeten Betätigungselementes in verriegelter Position des Rastelementes,
• Fig. 10 die Schnittansicht von Fig. 9 in entriegelter Position des Rastelementes,
• Fig. 11 die Schnittansicht entlang der Linie XI/XI von Fig. 9,
• Fig. 12 die Schnittansicht entlang der Linie XII/XII von Fig. 10,
• Fig. 13 eine der Fig. 9 entsprechende Schnittansicht mit einer anderen Schieberausführung und einer Bügelfeder mit kreisrundem Querschnitt in Verriegelungsstellung ihres Rastelementes,
• Fig. 14 die Ansicht von Fig. 13 in entriegelter Position des Rastelementes,
• Fig. 15 eine Unteransicht des Schiebers mit der Bügelfeder von Fig. 13 in seiner Verriegelungsstellung ohne Außen- und Innenrohr sowie ohne die Führungshülse,
• Fig. 16 die Unteransicht von Fig. 15 des Schiebers mit der aufgespreizten Bügelfeder in der entriegelten Position,
• Fig. 17 die Schnittansicht entlang der Linie XVII/XVII von Fig. 18, durch das Druckknopfgehäuse gemäß den Fig. 1 bis 5,
• Fig. 18 die Unteransicht des Druckknopfgehäuses in Richtung des Pfeiles XVIII von Fig. 17,
• Fig. 19 die Draufsicht auf das Druckknopfgehäuse in Richtung des Pfeiles XIX von Fig. 17,
• Fig. 20 die Schnittansicht des Druckknopfes entlang der Linie XX/XX von Fig. 21,
• Fig. 21 die Ansicht des Druckknopfes in Richtung des Pfeiles XXI von Fig. 22,
• Fig. 22 die Ansicht des Druckknopfes in Richtung des Pfeiles XXII von Fig. 20,
• Fig. 23 die Schnittansicht durch die Führungshülse entlang der Linie XXIII/XXIII von Fig. 24
• Fig. 24 die Unteransicht der Führungshülse in Richtung des Pfeiles XXIV von Fig. 23 mit dem Durchtrittsbereich für das Rastelement der Bügelfeder,
• Fig. 25 die Ansicht in Richtung des Pfeiles XXV von Fig. 23 mit dem Durchtrittsbereich für einen Druckknopf oder einen Schieber sowie die Enden der Bügelfeder,
• Fig. 26 die Ansicht in Richtung des Pfeiles XXVI von Fig. 24 auf eine Stirnseite der Führungshülse,
• Fig. 27 einen der Fig. 1 entsprechenden Längsschnitt durch ein teleskopierbares Staubsauger-Saugrohr mit einem Druckknopf und einer Bügelfeder mit kreisrundem Querschnitt und den damit zusammenwirkenden teilkreisförmigen Rastvertiefungen im Innenrohr,
• Fig. 28 eine gegenüber der Fig. 27 vergrößerte Schnittansicht im Bereich des Druckknopfes und der Führungshülse in der Verriegelungsstellung des Rastelementes,
• Fig. 29 die Schnittansicht von Fig. 28 in der entriegelten Stellung des Rastelementes der Bügelfeder,
• Fig. 30 die Ansicht der Bügelfeder der Fig. 27 bis 29 mit kreisrundem Querschnitt,
• Fig. 31 die Draufsicht auf die Bügelfeder in Richtung des Pfeiles XXXI von Fig. 30,
• Fig. 32 die Unteransicht der Bügelfeder mit ihrem Rastelement in Richtung des Pfeiles XXXII von Fig. 30,
• Fig. 33 die diametrale Schnittansicht durch die Bügelfeder von Fig. 30 entlang der Linie XXXIII/XXXIII
• Fig. 34 eine zweite Ausführungsform einer Bügelfeder mit einem rechteckigen, hier etwa quadratischen Querschnitt und einem ausgeprägten Rastvorsprung als Rastelement,
• Fig. 35 die Draufsicht auf die Bügelfeder von Fig. 34 in Richtung des Pfeiles XXXV,
• Fig. 36 die Unteransicht der Bügelfeder von Fig. 34 in Richtung des Pfeiles XXXVI.
• Fig. 37 die Schnittansicht durch die Bügelfeder entlang der Pfeile XXXVII/XXXVII von Fig. 34,
• Fig. 38 eine weitere Ausführungsform durch ein teleskopierbares Staubsauger-Saugrohr mit der im Querschnitt etwa quadratischen Bügelfeder der Fig. 34 bis 37 in verriegelter Position des Rastelementes, wobei die Bügelfeder das Außenrohr umgreift und mit ihrem Rastelement durch eine Öffnung im Außenrohr und der Führungshülse in eine Rastvertiefung des Innenrohres einrastet,
• Fig. 39 Schnittansicht von Fig. 38 in entriegelter Position des Rastelementes der Bügelfeder,
• Fig. 40 die Unteransicht des Schiebers mit der Bügelfeder in Richtung der Pfeile XL/XL von Fig. 38 in verriegelter Position, ohne Außen- und Innenrohr,
• Fig. 41 die Unteransicht entlang der Linie XLI/XLI von Fig. 39 in entriegelter Position der Bügelfeder, ohne Außen- und Innenrohr,
• Fig. 42 einen Längsschnitt durch ein teleskopierbares Staubsauger-Saugrohr entsprechend der Fig. 23 mit einer Bügelfeder mit kreisrundem Querschnitt und teilkreisförmigen Rastvertiefungen im Innenrohr, jedoch mit einer das Außen- und Innenrohr umfassenden Schieberhülse als Betätigungselement und einem darin angeordneten Sicherungsvorsprung,
• Fig. 43 eine vergrößerte Schnittansicht im Bereich der Schieberhülse von Fig. 42 in verriegelter Position der Bügelfeder mit einem das Rastelement untergreifenden Sicherungsvorsprung,
• Fig. 44 die Schnittansicht von Fig. 43 in entriegelter Position des Rastelementes der Bügelfeder.
• Fig. 45 eine der Fig. 11 entsprechende Schnittansicht durch eine weitere Ausführungsform eines teleskopierbaren Staubsauger-Saugrohres mit Außenrohr, Innenrohr und Bügelfeder, jedoch ohne Führungshülse aber dafür mit vier Warzenpaaren an der Innenseite des Außenrohres zur Halterung der Bügelfeder sowie zur Abstandshalterung von Außenrohr zu Innenrohr,

Several embodiments of the invention are illustrated in the drawings. Showing:

• Fig. 1 a longitudinal section through a telescopic vacuum cleaner suction tube with a trained as a push button actuator and a rectangular cross-section bow spring,
• Fig. 2 the view of the longitudinal cross-section in the region of the push button in opposite Fig. 1 enlarged view in locking position,
• Fig. 2a the partial view of the locking recesses and the groove for preventing rotation in the direction of arrow IIa of Fig. 2 .
• Fig. 3 the view of Fig. 2 in the unlocked position of the bow spring with latching element lifted out of the latching recess,
• Fig. 4 Section view along the line IV / IV of Fig. 2 .
• Fig. 5 Section view along the line V / V of Fig. 3 .
• Fig. 6 the view of the bow spring according to the Fig. 1 to 5 .
• Fig. 7 the top view of the bow spring in the direction of arrow VII of Fig. 6 .
• Fig. 8 the bottom view of the bow spring in the direction of arrow VIII of Fig. 6 .
• Fig. 9 one of the view of Fig. 2 corresponding partial view of the longitudinal cross-section in the region of an actuating element designed as a slide in the locked position of the locking element,
• Fig. 10 the sectional view of Fig. 9 in unlocked position of the locking element,
• Fig. 11 the sectional view taken along the line XI / XI of Fig. 9 .
• Fig. 12 the sectional view taken along the line XII / XII of Fig. 10 .
• Fig. 13 one of the Fig. 9 corresponding sectional view with another slider design and a bow spring with a circular cross-section in the locking position of its locking element,
• Fig. 14 the view of Fig. 13 in unlocked position of the locking element,
• Fig. 15 a bottom view of the slider with the bow spring of Fig. 13 in its locking position without outer and inner tube and without the guide sleeve,
• Fig. 16 the bottom view of Fig. 15 the slide with the spread-out bow spring in the unlocked position,
• Fig. 17 the sectional view taken along the line XVII / XVII of Fig. 18 , by the push button housing according to the Fig. 1 to 5 .
• Fig. 18 the bottom view of the push-button housing in the direction of arrow XVIII of Fig. 17 .
• Fig. 19 the top view of the push-button housing in the direction of arrow XIX of Fig. 17 .
• Fig. 20 the sectional view of the push button along the line XX / XX of Fig. 21 .
• Fig. 21 the view of the push button in the direction of the arrow XXI of Fig. 22 .
• Fig. 22 the view of the push button in the direction of the arrow XXII of Fig. 20 .
• Fig. 23 the sectional view through the guide sleeve along the line XXIII / XXIII of Fig. 24
• Fig. 24 the bottom view of the guide sleeve in the direction of arrow XXIV of Fig. 23 with the passage region for the latching element of the bow spring,
• Fig. 25 the view in the direction of the arrow XXV of Fig. 23 with the passage area for a push button or a slide and the ends of the bow spring,
• Fig. 26 the view in the direction of the arrow XXVI of Fig. 24 on an end face of the guide sleeve,
• Fig. 27 one of the Fig. 1 corresponding longitudinal section through a telescopic vacuum cleaner suction tube with a push button and a bow spring with a circular cross-section and the cooperating part-circular detent recesses in the inner tube,
• Fig. 28 one opposite the Fig. 27 enlarged sectional view in the region of the push button and the guide sleeve in the locking position of the locking element,
• Fig. 29 the sectional view of Fig. 28 in the unlocked position of the locking element of the bow spring,
• Fig. 30 the view of the bow spring the Fig. 27 to 29 with a circular cross section,
• Fig. 31 the top view of the bow spring in the direction of arrow XXXI of Fig. 30 .
• Fig. 32 the bottom view of the bow spring with its locking element in the direction of arrow XXXII of Fig. 30 .
• Fig. 33 the diametrical sectional view through the bow spring of Fig. 30 along the line XXXIII / XXXIII
• Fig. 34 a second embodiment of a bow spring with a rectangular, approximately square cross section here and a pronounced locking projection as a latching element,
• Fig. 35 the top view of the bow spring of Fig. 34 in the direction of the arrow XXXV,
• Fig. 36 the bottom view of the bow spring of Fig. 34 in the direction of the arrow XXXVI.
• Fig. 37 the sectional view through the bow spring along the arrows XXXVII / XXXVII of Fig. 34 .
• Fig. 38 a further embodiment by a telescopic vacuum cleaner suction tube with the cross-section approximately square bow spring of FIGS. 34 to 37 in locked position of the locking element, wherein the bow spring engages around the outer tube and engages with its locking element through an opening in the outer tube and the guide sleeve in a latching recess of the inner tube,
• Fig. 39 Section view of Fig. 38 in the unlocked position of the locking element of the bow spring,
• Fig. 40 the bottom view of the slider with the bow spring in the direction of the arrows XL / XL of Fig. 38 in locked position, without outer and inner tube,
• Fig. 41 the bottom view along the line XLI / XLI of Fig. 39 in unlocked position of the bow spring, without outer and inner tube,
• Fig. 42 a longitudinal section through a telescopic vacuum cleaner suction pipe according to Fig. 23 with a bow spring with a circular cross-section and part-circular detent recesses in the inner tube, but with a comprehensive the outer and inner tube slide sleeve as an actuating element and a securing projection arranged therein,
• Fig. 43 an enlarged sectional view in the region of the sliding sleeve of Fig. 42 in the locked position of the bow spring with a latching element engages under the locking projection,
• Fig. 44 the sectional view of Fig. 43 in unlocked position of the locking element of the bow spring.
• Fig. 45 one of the Fig. 11 corresponding sectional view through a further embodiment of a telescopic vacuum cleaner suction tube with outer tube, inner tube and bow spring, but without guide sleeve but with four pairs of warts on the inside of the outer tube for holding the bow spring and the distance from outer tube to inner tube,

In all figures, the telescopic vacuum cleaner suction pipe is always 1, the outer tube with 2, its inner tube with 3, the guide sleeve with 4, the actuator with 5, the bow spring with 6, the detent recess with 7 and the longitudinal axis of symmetry 8.

The individual embodiments differ essentially by the cross-sectional shape of the bow spring 6 and by the formation of the actuating element 5 either as a push button 9 or as a slide 10th

According to a first embodiment according to the Fig. 1 to 8 the actuating element 5 is designed as a push button 9. The cross-sectional shape of the bow spring 6 has according to the Fig. 6 to 8 the shape of an elongated rectangle, which also from the FIGS. 2 and 3 is apparent. The push button 9 is surrounded by a push-button housing 11, which is fixed to the top 2a of the outer tube z. B. is connected by gluing. The shape of the push button 9 is in every detail the FIGS. 20 to 22 and the shape of the push-button housing 11 in detail the 17 to 19 refer to.

The bow spring 6 according to the Fig. 6 to 8 is provided with inwardly bent free ends 12, 13, whereby a funnel-shaped gap 14 is formed, in which the push button 9 with its conical surface 9a (see Fig. 22 ) intervenes. In the funnel-shaped intermediate space 14 opposite part of the bow spring 6 is flattened, whereby this protrudes in the direction of the longitudinal axis of symmetry 8. This flattened part forms the locking element 15 which engages in correspondingly form-fitting and therefore also rectangularly shaped locking recesses 7 of the inner tube 3 (see FIGS. 2 and 3 ).

In the closed position of the bow spring 6 according to the Fig. 1 . 2 and 4 it is positively and non-positively under a certain bias in a groove 4e of the guide sleeve 4 (see FIGS. 24 and 25 ), whereby the push button 9 according to the Fig. 1 . 2 and 4 is pressed in its raised position, which signals the locking position of the bow spring 6. In this case, the bow spring 6 forms not only with its locking element 15, the locking element of the telescopic vacuum cleaner suction tube 1, but at the same time the return spring for the push button 9 to this in its raised position according to Fig. 1 . 2 and 4 and to keep it in the locked position.

The guide sleeve 4 according to the FIGS. 23 to 26 is provided with an opening 4a for the passage of the locking element 15 of the bow spring 6 and a second, diametrically opposite opening 4b for the passage of the ends 12, 13 of the bow spring 6 and the push button 9 and the slide 10. In addition, it has a collar 4c, with which it is fixed non-rotatably and immovably on the end face of the outer tube 2 in an extension 2b of the outer tube 2 at its end facing the inner tube 3 end.

Furthermore, the guide sleeve according to Fig. 23 provided with an anti-rotation projection 4d, which forms together with a groove 16 in the inner tube 3, the rotation 4d / 16, so that the inner tube 3 of the telescopic vacuum cleaner suction tube 1 relative to the outer tube 2 is not relatively rotated but only along the Symmetrielängsachse 8 can be moved.

This groove 16 passes through the middle of the region of the locking recesses 7 of the inner tube 3, whereby both this groove 16 and the locking recesses 7 can be made in a single embossing process of the inner tube 3.

This expression of the locking recesses 7 and the groove 16 is from the partial view of Fig. 2a seen.

In the Fig. 1 . 2 and 4 the locking position of the telescopic vacuum cleaner suction tube 1 is shown. In this position, the locking element 15 of the bow spring 6 is engaged in the nearest detent recess 7 of the inner tube 3. At the same time push button 9 is in the raised position. At an exit from the push-button housing 11 he 9 is prevented by its collar 9b. With its conical surface 9a of the push button 9 is located at the funnel-shaped inwardly bent ends 12, 13 of the bow spring 6 at. Characterized a funnel-shaped gap 14 is formed for the engagement of the push button 9 between these ends 12, 13 of the bow spring 6. When pressed down in the direction of arrow 18 of Fig. 3 and 5 slides the cone surface 9a on the funnel-shaped ends 12, 13 of the bow spring 6 down and spreads them in the direction of the double arrow 17 of Fig. 6 to both sides. By this spreading the locking element 15 in the direction of arrow 19 of Fig. 3 and 5 lifted out of the locking recess 7. As a result, the inner tube 3 is no longer with the outer tube 2 via the bow spring 6 and the guide sleeve 4th with the locking recess 7 in engagement. Then, the telescopic vacuum cleaner suction pipe 1 in both directions of the double arrow 20 of the Fig. 1 . 3 and 5 be moved parallel to the longitudinal axis of symmetry 8.

After releasing the push button 9, the locking element 15 slides under the bias of the bow spring 6 in the nearest detent recess 7 and the push button 9 is again in its initial position according to the Fig. 1 . 2 and 4 raised. In this position, the locking position of the telescopic vacuum cleaner suction tube 1 is reached. In this locking position, the inner tube 3 can no longer be undesirably inserted into the outer tube 2, even in the case of abrupt impulse forces exerted on the ends of the outer tube 2 and / or the inner tube 3, because the end edge 15a of the locking element 15 of the bow spring 6 is positively locked to the corresponding edge 7a the respective locking recesses 7 rests and no axial movement of the tubes 2, 3 allow more. A spreading of the bow spring 6, which would be a prerequisite for a solution of the lock, is not possible in this position, because even with jerky, exerted on the end edges 15a of the locking element 15 impulse forces no spreading of the bow spring 6 can be done because the edge 15a in the edge 7a "buried".

• a) Die Funktion einer Verriegelungsfeder, indem sie unter ihrer Vorspannung das Rastelement 15 stets in die nächstgelegenen Rastvertiefung 7 gleiten läßt und dort unter Vorspannung hält.
• b) Die Funktion eines Kraftübertragungselementes, in dem sie durch Aufspreizen mittels des Druckknopfes 9 bzw. eines Schiebers 10 oder eines anderen Betätigungselementes unter Erhöhung ihrer Vorspannung das Rastelement 15 aus der jeweiligen Rastvertiefung 7 heraushebt.
• c) Die Funktion einer Rückholfeder in Bezug auf das Betätigungselement 5, um dieses in einer Ausgangsposition in der Verriegelungsstellung des Rastelementes 15 mit der jeweiligen Rastvertiefung 7 zu halten.

The entire locking mechanism consists of only two parts, namely the bow spring 6 and the actuating element 5, here in the form of a push button 9 in conjunction with the known guide sleeve 4. This reduces the locking device to only two parts, namely on the bow spring 6 in conjunction with the actuating element 5. The bow spring 6 fulfills a total of 3 functions:

• a) The function of a locking spring by always under their bias, the locking element 15 to slide in the nearest detent recess 7 and holds there under bias.
• b) The function of a force transmission element in which it lifts out by spreading by means of the push button 9 and a slider 10 or other actuator while increasing its bias the locking element 15 from the respective detent recess 7.
• c) The function of a return spring with respect to the actuating element 5 to hold it in a starting position in the locking position of the locking element 15 with the respective locking recess 7.

The invention also allows the formation of an actuating element 5 in the form of a slider 10. A first embodiment of such a slider 10 is in the Fig. 9 to 12 illustrated, wherein the shape of the bow spring 6 the Fig. 6 to 8 corresponds, with the difference that the free ends 12, 13 are no longer inwardly, but now bent outwards and thus also with respect to the slider 10 as an actuating element 5 form a funnel-shaped gap 14. Otherwise are with the Fig. 1 to 8 matching parts with the same reference numerals. The guide sleeve 4 is identical to the embodiment of the guide sleeve according to the FIGS. 23 to 26 ,

Furthermore, now the slider 10 is positively coupled to the slider housing 11 a, which is fixedly mounted on the outer surface 2a of the outer tube 2. Within this slide housing 11a, the slide 10 is guided positively. Also in this embodiment, the outer tube 2 in the vicinity of its the inner tube 3 facing the end of an extension 2b, in which the guide sleeve 4 is housed, so that the full flow cross-section of the inner tube 3 is maintained at this point. According to the FIGS. 9 and 10 is the slider 10 in both directions of the arrow 21 parallel to the longitudinal axis of symmetry 8 of the telescopic vacuum cleaner suction tube 1 slidably. With a shift in both directions of the double arrow 21 of Fig. 9 there is an unlocking of the locking element 15 with the respective locking recess 7, because the slider 10 according to the FIGS. 15 and 16 has an hourglass-shaped shape and when the ends 12, 13 of the bow spring 6 according to Fig. 11 that is, at the narrowest point of its hourglass shape, is in its locking position, in which it is held under the bias of the bow spring 6.

In an only one-sided wedge shape of the slider 10 while an operation of the locking element 15 is possible, but not as advantageous as a double-sided displacement option according to the FIGS. 15 and 16 ,

When moving in one of the two directions of the double arrow 21 of Fig. 9 the slider 10 is guided within the stationary slide housing 11 a and the bow spring 6 at their ends 12, 13 spread. For this purpose, the slider 10 according to the FIGS. 15 and 16 two paired by the bent ends 12, 13 of the bow spring 6 formed casserole edges adjacent cone surfaces 10a, 10b, which are connected at their opposite tip areas hourglass-shaped together and thus in a movement of the slider 10 in each of the directions of the double arrow 21 parallel to the longitudinal axis of symmetry. 8 of the tubes 2, 3, the bow spring 6 spread. When you release the slider 10, this is under the bias of the bow spring 6 shifted so that the ends 12, 13 of the bow spring 6 again abut the narrowest point of the hourglass-shaped slide 10. These conical surfaces 10a, 10b extend to a plane passing through the longitudinal axis of symmetry 8 at an angle α between 30 ° and 60 °, advantageously below 45 °.

Alternatively, the conical surfaces 10a and 10b may also be formed as part of a quadrangular pyramid or as partial lateral surfaces of two straight circular cones, against whose lateral surface the ends 12, 13 of the bow spring 6 abut.

Another embodiment of a telescopic vacuum cleaner suction tube 1 is in the Fig. 27 to 29 shown. It is with the embodiment of the Fig. 1 to 5 matching parts with the same reference numerals. This embodiment differs essentially from the embodiment according to FIGS Fig. 1 to 5 in that the detent recesses 7 are formed in the inner tube 3 of semicircular pitch circular surfaces and the bow spring 6 has a circular cross section according to the embodiment of FIGS. 30 to 33 having. The Actuator 5 is also formed as a push button 9 and is located in the push-button housing 11, as to the Fig. 1 to 5 has been described. The Fig. 28 shows the locking position of the bow spring 6 with its locking element 15, whereas the Fig. 29 the unlocked position of the locking element 15 shows. Only in this position according to Fig. 29 For example, the tubes 2, 3 can be displaced relative to one another in the direction of the double arrow 20. However, this embodiment is - as in the prior art - afflicted with the disadvantage that the bow spring can slide at impulsive impact forces on the ends of the inner tube 3 and / or the outer tube 2 on the sliding surfaces of the locking recesses 7 by spreading the bow spring 6 upwards and thus an undesired unlocked position is achieved.

On the other hand, the embodiment of the Fig. 27 to 29 extremely simple in their construction and in their assembly.

Another embodiment of a telescopic vacuum cleaner suction tube 1 with an actuating element 5 in the form of a slider is in the Fig. 38 to 41 and the associated bow spring 6 in the FIGS. 34 to 37 shown. In this embodiment, the slide 1 1b is formed as a tubular sleeve valve 11b, which surrounds the outer tube 2 of the telescopic vacuum cleaner suction tube 1 in a partial region which corresponds approximately to the length of the guide sleeve 4. This slider 11b has at its the free, outwardly bent ends 12, 13 of the bow spring 6 facing surface area 24 guide grooves 22, 23, in which the ends 12, 13 of the bow spring 6 and guided during the displacement of the slide 11b in a the two directions of the double arrow 21 of FIGS. 40 and 41 be spread apart parallel to the longitudinal axis of symmetry 8, because the guide grooves 22, 23 according to the FIGS. 40 and 41 run divergently. This divergence is located on both sides of the narrowest point 25 of the guide grooves 22, 23. The latching projection 15 can either according to the FIGS. 11 and 12 be flattened and provided with a rectangular cross-sectional shape or according to Fig. 34 have a trapezoidal shape in the view. Accordingly, the locking recesses 7 are to be geometrically adapted accordingly and provided with a geometrically similar cross-sectional shape, thus also here with a trapezoidal cross-sectional shape.

As a special feature of the embodiment of Fig. 38 to 41 It should be noted that the bow spring 6, the outer tube 2 engages positively and non-positively and through an opening 28 according to Fig. 38 both the outer tube 2 and the guide sleeve 4 engages in the latching recess 7 of the inner tube 3.

Also in this embodiment, 21 in a shift in one of the two possible directions of the double arrow Fig. 1 respectively. FIGS. 40 and 41 the ends 12, 13 of the bow spring 6 spread apart and lifted the locking element 15 from the locking recess 7. Upon release of the sleeve-shaped slide 11b this is biased by the bow spring 6 and the ends 12, 13 are moved to the position in which these ends 12, 13 have the smallest distance from each other (see Fig. 38 combined with Fig. 40 ). In this position, the locking element 15 moves again into the nearest detent recess 7 a. Also in this embodiment, the bow spring 6 fulfills the above-described three functions.

Another embodiment of the telescopic vacuum cleaner suction tube 1 with a tubular sleeve valve 10c is in the FIGS. 42 to 44 shown. The difference from the embodiment with push button 9 according to the Fig. 27 to 29 is based now in that the circular cross-section bow spring 6 and its locking element 15 with a sleeve slide 10c with the same guide grooves 22, 23 for spreading the ends 12, 13 cooperates. According to the circular cross section of the bow spring 6, the locking recesses 7 are formed part-circular. For impulsive, exerted on the two ends of the outer and inner tube 2, 3 pulse forces, this is similar to the prior art described above and in the embodiment according to the Fig. 27 to 29 associated with the disadvantage that the latching element 15 of the bow spring 6 can slide on the part-circular locking recesses upwards and the bow spring 6 is zwangsaufgespreizt. To prevent this, the actuating element 5 as a the outer tube 2 completely encompassing sleeve slide 10c is formed, which has a locking projection 27 on its latching element 15 in its locking position nearest inner surface 26, in the locking position according to Fig. 42 and 43 engages the locking element 15 exactly in its central region. As a result, even in the case of impulsive impulse forces on the two ends of the tubes 2, 3 spreading of the bow spring 6 and thus a lifting or pressing of the locking element 15 does not take place.

In the case of the FIGS. 42 to 44 the securing projection 27 is rounded. However, it can also be provided with unillustrated, conical side surfaces. The design of the cam tracks with the guide grooves 22, 23 is advantageously matched to the design of the securing projection 27. In order not to be hindered by the securing projection 27 when releasing the lock, it is advantageous that the ends 12, 13 of the bow spring 6 are first performed on a longitudinal axis of symmetry 8 parallel path and only then in spreading cam tracks 22, 23, so that an always controlled spreading and thus unlocking the locking element 15 can be made from the respective locking recess 7.

In Fig. 45 is a cross-sectional view of another embodiment of a telescopic vacuum cleaner suction tube 1 shown, in which the outer tube 2 is provided with four pairs of warts 29, between which not only the bow spring 6 is supported, but also with their rounded ends 30 a spacer between the outer tube. 2 and form the inner tube 3. As a result, the guide sleeve 4 is dispensable. This can because of the here also to be arranged against rotation of a narrow sleeve ring 4c in conjunction with the projection 4d according to Fig. 23 consist. Otherwise, with the embodiment of the Fig. 9 to 12 matching parts with the same reference numerals. Because of the lack of in the FIGS. 23 to 26 Guide sleeve 4 shown, this embodiment may be referred to as a low-cost version. It is understood that the slider 10 can also be completely replaced by a push button 9.

The bow spring 6 is advantageously made of spring steel and is on a circumferential groove 4e (see FIGS. 23 and 26 ) of the guide sleeve 4 arranged spreadable. This guide sleeve 4 made of plastic is advantageously at the end of the outer tube 2 in a gap 2c according to the FIGS. 2 and 3 is fixedly arranged between an extended end 2d of the outer tube 2 and the outer surface 3a of the inner tube 3, whether by gluing or a press-fit connection or the like.

The core of the invention is based in all embodiments is to produce the lock only two parts, namely from the bow spring 6 on the one hand and the actuating element 5 on the other hand, which allows both training as a push button 9 and as a slider 10, 10c, 11b. This robust training a long life and extremely low clearance between the outer tube 2 and inner tube 3 is ensured.

Although the above claim 1 only a bow spring 6 with rectangular and circular cross-section has been claimed representative of a variety of cross-sectional shapes and realized as unpublished pattern. It is understood, however, that within the scope of the invention, an elliptical, oval, triangular, trapezoidal, hexagonal, octagonal or a multiple thereof can be readily realized as a cross-sectional shape of the bow spring 6, without departing from the scope of equivalents of the scope of the invention.

LIST OF REFERENCE NUMBERS

Telescopic vacuum cleaner suction tube

1

Outer tube of 1

2

Top of the outer tube 2

2a

Extension of the outer tube 2

2 B

Interspace / end of the outer tube 2

2c

extended end of the outer tube 2

2d

Inner tube of

3

Surface of the inner tube 3

3a

guide sleeve

4

openings

4a, 4b

narrow sleeve ring

4c

twist

4d, 16

circumferential groove of guide sleeve 4th

4e

actuator

5

bow spring

6

locking recesses

7

Edges of the locking recesses

7a

Longitudinal axis of symmetry

8th

push-button

9

conical or wedge-shaped end of the push button 9

9a

pusher

10

Cone surfaces of slide 10

10a, 10b

sleeve valve

10c, 11b

Housing of push button 9

11

slide housing

11a

free ends of the bow spring 6th

12, 13

gap

14

locking element

15

Edges of the locking element

15a

double arrow

17, 19, 20, 21

Guide grooves of slide 10c

22, 23

Area of slide 10c

24

narrowest point of the guide grooves 22, 23

25

Inner surface of slide 10c

26

Securing projection on inner surface 26

27

Opening in the outer tube 2 and guide sleeve 4th

28

Guide warts in the outer tube 2

29

rounded ends of 29

30

Claims (21)

1. Telescopic vacuum-cleaner suction pipe (1) with an outer pipe (2), an inner pipe (3), which can be telescoped therein and has latching depressions (7), a rotation-prevention means (4d; 16)and a locking device with a latching element (15), which can be disengaged from the latching depression (7) by an actuating element (5) located approximately diametrically opposite it, wherein the locking device comprises a clip spring (6) which engages with a form fit around at least the inner pipe (3) and by means of which, under spring prestressing, the latching element (15) is re-engaged in the nearest latching depression (7) of the inner pipe (3), as seen in the telescoping direction, characterized in that the clip spring (6) comprises an annular spring of rectangular or round cross section which, as an alternative, engages around the inner pipe (3), or a guide sleeve (4) or the outer pipe (2), not just with a form fit, but with a force fit, and the free ends (12, 13) of which can be spread apart from one another by the actuating element (5) in order for the locking to be released, as a result of which the latching element (15) is lifted out of the latching depression (7).
2. Telescopic vacuum-cleaner suction pipe according to Claim 1, characterized in that the free ends (12, 13) of the clip spring (6) are bent inwards or outwards in a funnel-like manner in the vicinity of the actuating element (5).
3. Telescopic vacuum-cleaner suction pipe according to Claim 1 or 2, characterized in that the latching depressions (7) in the inner pipe (3) are of shallow rectangular form.
4. Telescopic vacuum-cleaner suction pipe according to Claim 1 or 2, characterized in that the latching depressions (7) in the inner pipe (3) are provided with a known partially circular shape.
5. Telescopic vacuum-cleaner suction pipe according to one of Claims 1 to 4, characterized in that the actuating element (5) is formed by a pushbutton (9) arranged on the outer pipe (2) such that it can be moved perpendicularly to the longitudinal axis of symmetry (8).
6. Telescopic vacuum-cleaner suction pipe according to Claim 5, characterized in that the pushbutton (9) engages by way of its end (9a), which is directed towards the clip spring (6) and is provided with a cone or wedge shape, in the funnel-like interspace (14) between the inwardly or outwardly bent ends (12, 13) of the clip spring (6) and, under prestressing of the clip spring (6) in the locking position of the latter, is raised into a raised starting position within a housing (11) which encloses it.
7. Telescopic vacuum-cleaner suction pipe according to Claims 5 and 6, characterized in that the pushbutton (9), for the purpose of releasing the locking, is pushed down into the funnel-like interspace (14) between the inwardly or outwardly bent ends (12, 13) of the clip spring (6), by way of its end surface (9a), in the direction of the surface (3a) of the inner pipe (3), with the clip spring (6) being spread apart at the same time, and then the clip spring (6) thus disengages from the latching depression (7) of the inner pipe (3) by way of its diametrically opposite latching element (15).
8. Telescopic vacuum-cleaner suction pipe according to one of Claims 1 to 4, characterized in that the actuating element (5) comprises a slide (10) which is arranged on the outer pipe (2) such that it can be moved parallel to the direction of the longitudinal axis of symmetry (8).
9. Telescopic vacuum-cleaner suction pipe according to Claim 8, characterized in that the slide (10) has two cone surfaces (10a, 10b) which butt in pairs against the run-on edges formed by the bent ends (12, 13) of the clip spring (6) and which are connected to one another in hourglass form at their opposite pointed regions and thus spread open the clip spring (6) upon movement of the slide (10) in any direction of the double arrow (20) parallel to the longitudinal axis of symmetry (8) of the pipes (2, 3).
10. Telescopic vacuum-cleaner suction pipe according to Claim 8 or 9, characterized in that the cone surfaces (10a, 10b) run at an angle α of between 30° and 60° in relation to a plane running through the longitudinal axis of symmetry (8).
11. Telescopic vacuum-cleaner suction pipe according to Claim 9 or 10, characterized in that the planar cone surfaces (10a, 10b) are designed as part of a quadrangular pyramid.
12. Telescopic vacuum-cleaner suction pipe according to Claim 9 or 10, characterized in that the cone surfaces (10a, 10b) comprise partial lateral surfaces of two right circular cones.
13. Telescopic vacuum-cleaner suction pipe according to one of Claims 1 to 10, characterized in that the actuating element (5), both in the form of a pushbutton (9) and in the form of a slide (10), is arranged on a widened end region (2c) of the outer pipe (2), this end region being directed towards the inner pipe (3).
14. Telescopic vacuum-cleaner suction pipe according to Claim 8, characterized in that the slide (10) is provided on its surface region (24), which is directed towards the free outwardly bent ends (12, 13) of the clip spring (6), with guide grooves (22, 23) in which these ends (12, 13) are guided and are spread apart from one another upon displacement in one of the two directions of the double arrow (21) parallel to the longitudinal axis of symmetry (8) of the pipes (2, 3).
15. Telescopic vacuum-cleaner suction pipe with a clip spring of round cross section according to one of Claims 1 to 14, characterized in that the slide (10) is designed as a sleeve-type slide (10c) which engages all the way around the outer pipe (2) and, on its inner surface (26) nearest the latching element (15), has a securing protrusion (27) which, in the locking position, engages precisely beneath the latching element (15) in its central region.
16. Telescopic vacuum-cleaner suction pipe according to Claim 15, characterized in that the securing protrusion (27) is provided with conical side surfaces or is rounded in the direction of the latching element (15).
17. Telescopic vacuum-cleaner suction pipe according to Claim 15 or 16, characterized in that the curved path of the guide grooves (22, 23) is coordinated with the geometry of the securing protrusion (27).
18. Telescopic vacuum-cleaner suction pipe according to one of Claims 1 to 17, characterized in that the clip spring (6) consists of spring steel.
19. Telescopic vacuum-cleaner suction pipe according to one of Claims 1 to 18, characterized in that the clip spring (6) is arranged such that it can be spread open on an encircling groove (4e) of a guide sleeve (4) which is arranged in a fixed position between the outer and inner pipes (2, 3) in a widened end region (2c) of the outer pipe (2).
20. Telescopic vacuum-cleaner suction pipe according to one of Claims 1 to 19, characterized in that the rotation-prevention means (4d, 16) comprises, in a manner known per se, a longitudinal groove (16) in the inner pipe (3), this groove running parallel to the longitudinal axis of symmetry (8) and having a protrusion (4d) of the guide sleeve (4) engaging in it with a form fit.
21. Telescopic vacuum-cleaner suction pipe according to Claim 20, characterized in that the longitudinal groove (16) is arranged in the inner pipe (3) in the region of the latching depressions (7).

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