GB2514082A

GB2514082A - Telescoping connection between tubular members

Info

Publication number: GB2514082A
Application number: GB1302243.9A
Authority: GB
Inventors: Ian R D Bevis
Original assignee: Numatic International Ltd
Current assignee: Numatic International Ltd
Priority date: 2013-02-08
Filing date: 2013-02-08
Publication date: 2014-11-19
Also published as: GB201302243D0

Abstract

A telescoping connection includes an inner elongate tubular member and an outer tubular member 215, the inner tubular member having an outside surface portion provided with a row of axially spaced apart locking features 214. One end region 217 of the outer tubular member 215 is provided with an at least one axially directed tongue 218A which projects from the outer tubular member 215 so as to overlay the outside surface of the inner tubular member. The tongue 218a is provided on an underside of the outer tubular member 215 with a counterpart locking feature 245 for engaging each of the locking features 214 on the outer surface portion of the inner tubular member. A locking sleeve 224 is provided around the outer tubular member 215. The telescoping connection may be used in a vacuum cleaner wand.

Description

Telescoping connection between tubular members The present invention concerns the field of tubular connectors, and in particular relates to connections capable of locking a telescoping connection in several selectable degrees of tubular extension or retraction. The invention finds particular application in wands for vacuum cleaners or other vacuum floor treatment devices such as carpet cleaners.

Telescoping tubular members having such connectors are well known in the art.

Known arrangements typically involve a latch on an outer tube passes through an aperture to engage with one of a series of axially spaced slots or depressions in the inner tube. The latch may comprise a biased rocker mounting which has a finger or thumb tab which may be depressed to lift the latch lock from engagement with the slot or depression.

For example US5332266 discloses a telescoping connector in which a manually operable actuator element (30 in fig 1] which is resiliently biased against a constraining element, which element is pivotally engaged with a sleeve at one end.

US5692782 discloses two acutely angles biased locking elements pins which engage with two distinct locking grooves.

US6454308 discloses telescoping pipes which are partially or wholly transparent so that the user can check for blockages etc. US6494492 discloses a telescoping connection in which a collar sleeve can travel along the outer tube, but is constrained by balanced springs. The collar can be used to disengage locking members from a radial groove.

US702 5383 discloses a telescoping connection which involves the use of a manually operable slider 30 which is biased against a locking member, and may be retracted to unlock the tubes.

US8038173 discloses an actuator "shuttle" or slider which has front and rear springs, and the outer tube having a tunnel for retaining and guiding the slider.

You have no such slider.

US2007/0130724 -this patent application discloses that there are axially spaced latch pockets on the inner tube surface, and an axially extending row of latch bumps on am US7516988 discloses a push-button [bottom') locking assembly placed in a slot of the external tube, with a spring biasing the locking element into engagement.

The present invention seeks to provide a simplified telescoping connection which is lockable in several discrete lengths. The present invention provides a connection which obviates the need for a user operable finger latch, which latches can be prone to failure or jamming with dirt The connection is also easier to manufacture and assemble.

According to one aspect of the present invention there is provided a telescoping connection between an inner elongate tubular member and an outer tubular member, the inner tubular member having an outside surface portion provided with a row of axially spaced apart locking features, wherein one end region of the outer tubular member is provided with one or more axially directed tongues which proj ect from the outer tubular member so as to overlay the outside surface of the inner tubular member, at least one of which tongues is a locking tongue provided on an underside thereof with a counterpart locking feature for engaging each of the locking features on the outer surface portion of the inner tubular member. A locking sleeve is provided around the outer tubular member, which locking sleeve has an inner surface provided with a tongue constraint feature, the sleeve being movable with respect to the outer tubular member between a first position in which the tongue constraint feature displaces the locking tongue with the counterpart locking feature inwardly into engagement with one of said locking features of the inner tubular member, to a second position in which the tongue constraint feature is spaced apart from the locking feature so that the tongue is free to retract from engagement with the locking feature of the inner tubular member. In this way the inner and outer tubular members may be connected together in several telescoped extended or retracted positions. The connection maybe released simply by manipulation of the sleeve.

In one preferred aspect of the invention the locking sleeve is rotatable with respect to the outer tubular member and the constraint feature comprises a locking block provided on the sleeve inner surface so that in the first position the locking block displaces the locking tongue with the counterpart locking feature inwardly into engagement with one of said locking features of the inner tubular member, and in the second position the locking block is rotated away from said locking tongue so that the tongue is free to retract from engagement with the locking feature of the inner tubular member. The inner surface of the sleeve may also be provided with a recess at a location which corresponds to the sleeve second position and into which the locking tongue retracts. This sleeve recess is preferably provided adjacent the locking block.

The rotation of the sleeve with respect to the outer tubular member may be limited by stops corresponding to the first and second positions. These stops may conveniently be axially directed ribs or steps formed in the outer surface of the outer tubular member and/or the inner surface of the sleeve.

In another preferred aspect of the invention the locking sleeve is adapted to be axially translatable between said first and second positions and wherein the tongue constraint feature comprises a pinched end region of the sleeve, so that in the first position the pinched end region depresses said locking tongue, and in the second position the pinched end region is axially spaced apart from the locking tongue so that the tongue is free to retract from engagement with the locking feature of the inner tubular member.

The sleeve may be axially translatable by means of a helical threaded connection between the locking member and the outer tubular member.

The threaded connection of the sleeve is preferably disposed behind the pinched region of the sleeve, so that as the sleeve is wound in a tightening direction relative to the outer tube the pinched region is urged against the underlying locking tongue.

In any of the foregoing arrangements, the locking tongue is preferably biased to retract from engagement with the locking feature. Thus once the constraint feature retreats or moves away from the locking tongue per the second position) the tongue springs away from the locking feature in which it had been engaged in the first position.

The axially spaced apart locking features of the inner tubular member may be radial depressions or slots. The depressions or slots may be formed or provided in a sidewall of the inner tubular member. The slots may be provided in an axially extending elongate depression provided or formed in the sidewall. The depression may be integral with the tubular sidewall, or provided as an insert therein. The depressions or slots preferably are each elongate in a circumferential direction. In one embodiment the depressions comprise hemi-hexagonal troughs.

The tongue's counterpart locking feature may comprise a bead or rib which is sized to be accommodated in any one of the axially spaced locking features. The counterpart feature is preferably generally complementary in shape to a depression of slot which forms each axially spaced locking feature. In one embodiment the rib has a generally hemi-spherical section.

The locking sleeve maybe adapted to be axially translatable by a helical threaded connection between the locking sleeve and the outer tubular member. The threaded connection of the sleeve may be disposed behind the pinched portion of the sleeve, so that as the sleeve is wound in a tightening direction relative to the outer tube the pinched portion is urged against the underlying tongue. The tongue may be provided with a tapered outer surface region towards a free end thereoL The tongue's locking feature may be provided at the free end region thereof.

In one embodiment a plurality of circumferentially disposed tongues are provided. Preferably only one of said tongues is a locking tongue whereas the others are passive tongues which serve to locate the inner tubular member for sliding within the outer tubular member. The tongues may each have a tapered outer surface region. For example, to complement the pinched inner portion of the locking sleeve in some embodiments.

The outer tubular member may be attached to a free end of a further elongate tubular member, or may be integrally formed as one end of an elongate tubular member. In either case the elongate inner tubular member can telescope within the outer tubular member/further tubular member.

The outer tubular member may be provided with a female seat in which the distal end of said further elongate member is accommodated. The two may be attached as an interference fit, or by adhesive or welding, or by other means known in the art of tubular connections.

The locking sleeve and the outer tubular member may each be formed of moulded plastics material. The locking tongue or tongues and the passive tongues are preferably moulded with the outer tubular member as a unitary article. In the specific embodiments only one locking tongue is shown in each connection. However more than one locking tongue may be located, for example (and without limitation) at 0 and 180 degrees; or 0, 120 and 240 degrees, or 0, 90, 180 and 270 degrees. In which case corresponding axially spaced indents would be provided along the inner tubular member.

Although the present invention has general application in devices having telescoping tubular joints, in a preferred embodiment the connection is provided between tubular members of a vacuum cleaner wand (or other floor treatment device), so as to permit telescoping of the wand.

Thus in accordance with another aspect of the invention there is provided a vacuum cleaner or floor treatment device having a wand provided at a distal end thereof with an inlet vent for admitting air-entrained detritus and having a proximal end which feeds into a machine body portion for collection of detritus therein, which wand comprises telescoping tubular members provided with a connection as claimed in any of the preceding claims.

Following is a description of modes for putting the present invention into practice, by way of example only and with reference to the accompanying drawings, in which: Figure 1 is an exploded view of a telescoping connection in accordance with a first embodiment of the invention used in a vacuum cleaner wand.

Figure 2 is a perspective view of the connection of the first embodiment.

Figure 3 is an axial cross-section through the connection of the first embodiment.

Figure 4 is a perspective three quarter view with a transverse cross section of a telescoping connection in accordance with a second embodiment of the invention.

Figure 5 is a longitudinal sectional view of the connection of the second embodiment showing an unlocked configuration.

Figure 6 is a longitudinal sectional view of the connection of the second embodiment showing a locked configuration.

Figure 7 is a perspective three quarter view with transverse section of a rear end region of the outer tube and sleeve member of the connection.

Two embodiments of the invention are described below and in the drawings. The reader will understand that where appropriate or possible features of one embodiment may be interchanged with, or added to, features of the other embodiment.

First embodiment In figure 1 an inner telescoping tube is shown at 10. The tube is formed with an elongate axial recess 11 which is closed at one end region with a curved boundary 12 and which is open at the opposite end region 13. Ten uniformly spaced apart elongate indents 14 are provided along the recess, as shown in figure 1. Said opposite end region receives an annular seat member 23, which seat member has a flared distal end 9 and short axial groove 8, which corresponds to the recess end region of the inner tube.

An outer tube 15 is formed of moulded resilient plastics material. The outer tube has an outer surface formed with a screw thread 16. A distal end region 17 is formed with six circumferentially disposed axially directed tongues 18 [three visible). Each tongue has a gradual axial taper, best seen in figure 2. Each tongue is separated from its neighbour by an acute V-notch or cut-out 19, which permits flexing of the tongues inwardly or outwardly.

An elongate further outer tube 20 has a free end which is formed with a shoulder 21 and annular region 22. A sleeve member 24 is formed of moulded plastics material and is provided with a plurality of circumferentially spaced apart grip ridges 25. An inner surface of the sleeve is formed with a screw thread 28 which is complementary to the thread 16 of the outer tube 15. A distal end of the sleeve is formed with a pinched region 26 of gradually decreasing internal [and external) diameter.

The connection is shown assembled and in cross section in figure 2. The outer tube 15 is attached to the outer surface of the distal end of the further outer tube 20. An inwardly directed annular shoulder 27 of the outer tube provides a stop against which the end of the further outer tube sits. The sleeve 24 is threaded onto the outer member's thread 16. When the sleeve is fully tightened the pinched end of the sleeve abuts an outer surface of one of the tongues iSA. This tongue has an end which is formed with a transverse [circumferential) rib 30 of semi-circular cross-section. The rib is held in engagement with one of the indents 14A, as shown in figure 3. The indent has a semi-hexagonal section which provides a feed ramp and an exit ramp for the tongue rib. The inner tube 10 thus is held telescoped within the further outer tube 20.

By unscrewing the sleeve 24 the pinched portion retreats and the tongue can spring back from the indent. The outer tube (with further outer tube) may then be moved relative to the inner tube so as to extend or retract the telescoped tubes. The annular shoulder 27 and the flared end 9 of the tube seat member provide sliding constraint to guide and easy sliding of the inner and outer tubed with respect to one another.

Second embodiment In this embodiment the numbering system generally accords with that of the first embodiment, but with modified components given the prefix of 2 to indicate the second embodiment.

The second embodiment is identical to the first embodiment, with the exception of the configuration of the outer tube 215 (15 in the first embodiment) and the sleeve member 224 [24 in the first embodiment).

In figure 4 the inner telescoping tube is shown at 210. As before, the tube is formed with an elongate axial recess 211 which is closed at one end region with a curved boundary 212 and which is open at the opposite end region. Ten uniformly spaced apart elongate indents 214 (one visible in figure 4) are provided along the recess.

The outer tube 215 (see figure 5) is formed of moulded resilient plastics material. The outer tube has an outer surface formed with circumferentially spaced axial ribs (as for the first embodiment at 25). A distal end region 217 of the tube is formed with five circumferentially disposed axially directed tongues 218. A sixth tongue is omitted. Each tongue has an upper surface formed with a gradual axial taper, best seen in figure 5 or 6. Each tongue is separated from its neighbour by a narrow acute V-notch or cut-out 219, which permits flexing of the tongues inwardly or outwardly. One 218A of the tongues is a locking tongue formed with an inwardly directed depending circumferentially elongate nub 245 [see figure 4]. The nub is formed with waist regions 246 [see figure 4) which facilitate entry of the nub into an indent [214, see figure 5) in the inner tube recess 211. The tongues in this embodiment are unbiased) but the locking tongue can be biased slightly outwardly so as to retract from the indent when the tongue is released. Otherwise, the tongue may simply be axially slid out the dent by travel of the inner tube.

An opposite end region of the outer tube is formed with a circumferential radially raised lip 216 best seen in figure 5 or 6. A corresponding circular groove 228 is formed on the inside surface of the locking sleeve 224. The sleeve is therefore a snap-fit on the lip, and capable of sliding rotation on the outer tube 215.

An elongate further outer tube 20 is attached to the outer tube as an extension thereof, as for the first embodiment. Similarly a seat member 23 (see figure 1] is provided as for the first embodiment.

The locking sleeve 224 is formed of moulded plastics material and is provided with a plurality of circumferentially spaced apart axially extending grip ridges 225. An inner surface of a front region of the sleeve is formed with a wedge-shaped recess or cut-out 240 into which the locking tongue maybe displaced when the tongue is in an unlocked, second position (as shown in figure 4 and figure 5). Adjacent the recess is a locking block 241 which is formed in the inside surface front region of the sleeve. The locking block depresses and constrains the locking tongue so that its nub sits in an indent in the inner tube, when the sleeve is in the first) locked position (as shown in figure 6). Rotation of the sleeve is limited by the axial outer ribs 242, 243 formed on the outer tube which act as boundaries for the travel of an axial rib 244 formed on an inner surface of the sleeve (see figure 7].

It will be apparent from the foregoing that when the connection of the second embodiment is in use, the locking sleeve may be moved to the second position shown in figure 4 and the inner tube telescoped in or out to give the desired overall tube length. The sleeve may then be rotated (in the direction of the arrow shown in figure 4] so that the locking block 241 sits above the locking tongue 218A, thereby locking the telescoped tubes by entry of the tongue nub 245 into the selected indent 214, as shown in figure 6.

The present invention uses a locking collar or sleeve which may be manually rotated to lock telescoped tubes at a selected degree of extension of retraction.

The arrangements obviate the need for a pivoting or moving latch/button which may be prone to fail or become jammed. The small number of parts required renders the connection easy to manufacture and assemble.

Claims

Claims 1. A telescoping connection between an inner elongate tubular member and an outer tubular member, the inner tubular member having an outside surface portion provided with a row of axially spaced apart locking features, wherein one end region of the outer tubular member is provided with one or more axially directed tongues which project from the outer tubular member so as to overlay the outside surface of the inner tubular member, at least one of which tongues is a locking tongue provided on an underside thereof with a counterpart locking feature for engaging each of the locking features on the outer surface portion of the inner tubular member, and wherein a locking sleeve is provided around the outer tubular member, which locking sleeve has an inner surface provided with a tongue constraint feature) the sleeve being movable with respect to the outer tubular member between a first position in which the tongue constraint feature displaces the locking tongue with the counterpart locking feature inwardly into engagement with one of said locking features of the inner tubular member, to a second position in which the tongue constraint feature is spaced apart from the locking feature so that the tongue is free to retract from engagement with the locking feature of the inner tubular member.
2. A connection as claimed in claim 1 wherein the sleeve is rotatable with respect to the outer tubular member and the constraint feature comprises a locking block provided on the sleeve inner surface so that in the first position the locking block displaces the locking tongue with the counterpart locking feature inwardly into engagement with one of said locking features of the inner tubular member, and in the second position the locking block is rotated away from said locking tongue so that the tongue is free to retract from engagement with the locking feature of the inner tubular member.
3. A connection as claimed in claim 2 wherein the inner surface of the sleeve is provided with a recess at a location which corresponds to the sleeve second position and into which the locking tongue retracts.
4. A connection as claimed in claim 3 wherein the sleeve recess is adjacent the locking block.
5. A connection as claimed in any of the preceding claims wherein rotation of the sleeve with respect to the outer tubular member is limited by stops corresponding to the first and second positions.
6. A connection as claimed in claim 1 wherein the sleeve is adapted to be axially translatable between said first and second positions and wherein the tongue constraint feature comprises a pinched end region of the sleeve, so that in the first position the pinched end region depresses said locking tongue, and in the second position the pinched end region is axially spaced apart from the locking tongue so that the tongue is free to retract from engagement with the locking feature of the inner tubular member.
7. A connection as claimed in claim 6 wherein the sleeve is axially translatable by means of a helical threaded connection between the locking member and the outer tubular member.
S. A connection as claimed in claim 7 wherein the threaded connection of the sleeve is disposed behind the pinched region of the sleeve, so that as the sleeve is wound in a tightening direction relative to the outer tube the pinched region is urged against the underlying locking tongue.
9. A connection as claimed in any of the preceding claims wherein the locking tongue is biased to retract from engagement with the locking feature
10. A connection as claimed in any of the preceding claims wherein the axially spaced apart locking features are depressions or slots.
11. A connection as claimed in claim 10 wherein the depressions or slots are formed or provided in a sidewall of the inner tubular member.
12. A connection as claimed in claim 11 wherein the slots are provided in an axially extending elongate recess provided in the sidewall.
13. A connection as claimed in any of claims 10 to 12 wherein the depressions or slots are each elongate in a circumferential direction.
14. A connection as claimed in any of the preceding claims wherein the locking tongue's counterpart locking feature comprises a bead or rib which is sized to nest in any one of the axially spaced locking features.
15. A connection as claimed in any of the preceding claims wherein each tongue is formed with an outer surface portion which tapers towards a free end thereof.
16. A connection as claimed in any preceding claim wherein the tongue's counterpart locking feature is provided at a free end region thereof.
17. A connection as claimed in any of the preceding claims wherein a plurality of circumferentially disposed tongues is provided, only one of which is provided with said locking feature.
18. A connection as claimed in any of the preceding claims wherein the outer tubular member is attached to a free end of a further elongate tubular member.
19. A connection as claimed in claim 18 wherein the outer tubular member provides a female seat in which the distal end of said further elongate member is accommodated.
20. A connection as claimed in any of the preceding claims wherein the connection is provided between tubular members of a vacuum cleaner wand, so as to permit telescoping of one wand portion within another in a selected one of a plurality of extension or retraction positions.
21. A vacuum cleaner or floor treatment device having a wand provided at a distal end thereof with an inlet vent for admitting air-entrained detritus and having a proximal end which feeds into a machine body portion for collection of detritus therein, which wand comprises telescoping tubular members provided with a connection as claimed in any of the preceding cilaims.