DE2642235A1 - Telescopic tube union for stands or scaffolding - has ends twisted to lock via spring plates engaging in adjacent window recesses - Google Patents

Abstract

The telescopic tube for frames, stands and scaffolding can be used for cameras, projectors and lamp stand legs or collapsible furniture for camping, tent poles, and car radio aerials. Tubular sections can be pushed one inside the other and have a spiral cross-section. By twisting the tube ends against each other at a point between their min. and max. drawn-out length, they can be directly held rigidly. The securing of each tube section at this point is achieved by spring plates on one section engaging in a window-like recess of the neighbouring section.

Description

Telescopic tube for stands, racks and scaffolding

The invention relates to a telescopic tube for stands, racks and Scaffolding with a locking option that is independent of the extension length, in particular for camera and lamp stands as well as for frames for surveying, decoration and Building purposes.

With such tripods and racks, a fast, if possible Infinitely variable height or length can be ensured as well as stability and resilience.

As is known, these requirements are taken into account with tripod legs worn that telescopic tubes or profile strips by means of locking screws, Clamps or cams are secured against shifting, whereby it is necessary is, for every two mutually adjustable pipe sections at least one locking member and to put each of them into action, mostly by hand.

The invention is based on the object of using locking members also to be superfluous, as the securing of only two pipe sections against each other.

This object is achieved according to the invention telescoping pipe pieces have a spiral cross-section and are by turning the outermost pipe sections at the pipe ends into one Tighten direction mutually; here the clamping effect takes place on all pipe sections approximately evenly, because the twisting forces in the entire pipe system are approximately equal Distribute homogeneously, assuming pipe sections with the same spiral pitch. A twisting of the outermost pipe pieces in the other direction means the cancellation the tensioning effect at the initially weakest point, where now two pipe sections up to their point of overlap or, if applicable, cranking point are rotated further, there after they have been made Stop can no longer be rotated against each other in the same direction and therefore relax the next less tensioned pair of pipe sections in the same way; eventually all the pipe sections will be released from their tension, the outermost ones will find a final stop on the pipe sections connecting them and the length of the telescopic tube can be adjusted to the minimum or maximum be.

Around the minimum or maximum of the length of such a telescopic tube to be able to define it in such a way that it does not fall into its individual pieces of pipe when it is pulled out disintegrates or the other pieces of pipe when pushed together in one, the outermost, disappear completely, it is necessary to create stops in both directions.

For use cases where the stability and dimension for the Reducing the outer diameter of the pipe section does not play a major role To limit the extension length, flanging or crimping the ends of the pipe section on the E.g. the upper end inwards and e.g. the lower end outwards, a principle So that is what is usually the case with the well-known telescopic vehicle antennas used. The minimum length is determined by an extreme increase in the outer diameter at the end of the thinnest, topmost pipe section with e.g.

a ball attached there. If the pipe pieces are only relatively are difficult to slide into each other, there is no need for a base plate or flanging inwards at the lower end of the thickest pipe section.

On the other hand, there are stability and the associated greater wall thicknesses of the pipe sections required, it is advisable to place these pipe sections in the lower Cut out part in such a way that outwardly resilient tabs are created in the window on the upper part or in the flap cutouts on the lower part of the next thicker one Snap the pipe sections into place.

The edges of the window or flap cutouts must be designed in this way be that they are e.g. pulling apart further to prevent however, allow them to be pushed together again. In addition, the rotatability is allowed of the pipe sections against each other are not affected by the tabs.

Therefore, the latter are, as it were, in the tensioning direction on the pipe sections posted. Those edges of the window or. Tab cutouts, which for Point the middle of the pipe section are beveled in such a way that they are when the pipe length is adjusted from one of its two extreme values (minimum and maximum length) this outwards Push back the springy tabs.

The advantages achieved with the invention are, on the one hand, the omission special locking members, such as locking screws, cams and the like. And the second the possibility of all pipe sections at the same time by just one turn of the pipe ends to brace against each other.

In the case of more stable designs, creating stops in Direction of pulling out and pushing together through outwardly resilient tabs, which snap into window-like cutouts of the adjacent pipe section, another benefit. It is particularly favorable that after they have been completely nested the tabs of the thinner pipe sections against the inside of the tabs the next thicker pipe pieces feathers and in this way window-like Find cutouts that they can snap into. The bevelling of those cutout edges facing the middle of the pipe section, only a shifting of the tab (the yes is connected to the next inner neighboring pipe section) in the direction of the center of the pipe section to, but not to the outside world.

The drawing represents two exemplary embodiments of the. Invention.

Fig. La shows the cranked version in a plan view of four nested pieces of pipe with a spiral cross-section in a relaxed State in which the telescopic tube adjusts with respect to its extension length leaves. Fig. Ib shows from the same point of view the same pipe version in a clamped position State.

This cranked tube version is likely to be used primarily for a standard Manufacture of such pipe sections according to the invention come into consideration because the latter could be made into one another as corresponding profile tubes.

FIGS. 2a and 2b show states analogous to FIGS. 1a and Ib (... a = relaxed; ... b = tense) the version in which the spiral ends overlap are. The overlapped version is obtained from tubes with a circular cross-section, cut lengthways and put them in a vice or in special clamping devices be bent so that they have a spiral cross-section.

FIGS. 3a and 3b show the tubular version shown in FIGS. 2a and 2b from the perspective to clearly emphasize the principle. The arrows in Figures la, Ib, 2a and 2b point in the direction in which the innermost can still be twisted against the outermost pipe section (in the figures ... a in the direction "Bracing" and with the figures ... b in the direction of "relaxing").

Fig. 4a illustrates pipe pieces pushed into one another, which have a relatively large wall thickness and their outer diameter only so little are reduced as possible in order to obtain the greatest possible stability ..

Fig. 4b shows the same pipe system in the fully extended state.

You can see in both representations (4a and 4b) in which directions The tabs allow the pipe sections to be shifted against each other. allow.

Figures 5a (pushed together) and 5b (pulled apart State) show how by appropriate arrangement of reducers at the top and the lower end of the pipe sections falling apart or pushing together completely the pipe system is prevented. This is only made possible by a relatively strong one Reduction of the pipe section outer diameter. reached, which affects the stability and - because of the reducers - the extension length is reduced (comparison: Fig. 4b to Fig. 5b), if one assumes the same initial lengths (comparison: Fig. 4a to Fig. 5a).

The arrows in Figures 4a, 4b, 5a and 5b point in the direction into which the innermost pipe section is moved when the pipe system is relaxed can.

Claims (2)

Claims: W telescopic tube for tripodsf racks and scaffolding with a locking option that is independent of the extension length, especially for Tripod legs for cameras, projectors and lights, for vertical and horizontal Striving of Ge -stellen for decoration, measuring and building purposes, for the erection of Backdrops and stands, for handles of cleaning and gardening tools as well as of other tools, for chair, table and other furniture legs, especially for camping purposes, for tent poles and masts and for retractable vehicle antennas, d a d u r c h g It is not shown that the telescopic tube is made of telescopic tube pieces consists, which have a spiral cross-section, whereby by means of a Twisting the pipe ends against each other the telescopic tube in the area between his minimum and maximum extension length is continuously adjustable. 2. Telescopic tube according to claim 1, d a d u r c h g e k e n n z e i c h n e t, d a ß especially with more stable versions of the inventively manufactured Telescopic tube resilient tabs are attached to the pipe pieces, which are in window-like Snap the cut-outs of the next pipe section into place and thus excessive pulling apart or prevent nesting, with the tabs in the collapsed The condition of the pipe system is at the same level and in that of the neighboring one Snap in the tab of the released window-like recesses. All pipe pieces except the one furthest inside, which can be pulled out must be the same length to tackle it. The tabs are beveled by Edges pushed out of their locked position when adjusting the pipe length.