GB1589196A

GB1589196A - Air tubes and layout of same in a caravan

Info

Publication number: GB1589196A
Application number: GB5970/78A
Authority: GB
Original assignee: Kreis & Co Trumageraeteba GmbH
Current assignee: Kreis & Co Trumageraeteba GmbH
Priority date: 1977-02-23
Filing date: 1978-02-15
Publication date: 1981-05-07
Also published as: NL7801699A; FR2381975A1; DE2707779B2; DE2707779C3; IT1092542B; FR2381975B1; IT7819849A0; BE863967A; DE2707779A1

Description

(54) AIR TUBES AND LAYOUT OF SAME IN A CARAVAN (71) We, PHILIPP KREIS GmbH., & Co., TRuMA-Gerätebau, a corporation organised under the laws of the Federal Republic of Germany, of Neumarkter Strasse 34--36, D8000 München 80, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to an air distribution tube, especially for occupied rooms such as caravans.

With a known air distribution duct (DT GM 74 33 779), straight baffle ribs project into the air duct cavity. In order to achieve as even an air distribution as possible, these baffle ribs increase in their length in the direction of the air flow and are grouped in pairs. The baffle ribs occupy the total cavity width of the air duct. Although it is possible to achieve an evenly spread air outflow with these baffle ribs even on a longer tube length, the design of these distribution ducts would be rather elaborate and really only appropriate for ducts having a rectangular crosssection, i.e. so-called converter strips. With another known deflector device (DT-PS -856 980) for flowing media in ovens, drying equipment and similar, plane stepped deflector surfaces are connected in front of a slotted grid.Since these deflector surfaces are essentially of the same length, increasing gaps are formed between them and the - slotted grid in the direction of flow, these gaps opposing a separation of certain partial flows.

With aother deflector device (DT-PS 919 657) for compartment grates, the deflector surfaces, although bordering directly on the grate surface, are bent blade-like at their free end. Although these known deflector devices may be of use for ducts with large crosssections at the end of which a baffle wall favours a flow deflection, they ate not very suitable for small-bore flow tubes. Finally, the baffles projecting vertically into the cavity impair the flow properties.

It is, therefore, the object of the invention to provide an air distribution tube the design of which, with a largely steady and improved air discharge, is essentially simpler and thus cheaper to manufacture and which is particularly suitable for being installed in a caravan.

According to the present invention, an air distribution tube has at intervals in the longitudinal direction a plurality of air outlet apertures, each aperture being bounded by (a) an outer edge at the periphery of the tube, and (b) an inner edge on an end of a respective air scoop which is integral with the remainder of the tube and which extends from said inner edge to a position, spaced longitudinally from said edge, where it merges into the periphery of the tube, the outer and inner edges being spaced in a direction which is substantially normal to the longitudinal direction of the tube.

These air scoops, which at the same time serve as baffles for the escaping air, are particularly easy to produce if they are formed out of the tube wall. They form blade-like catchers projecting into the tube interior and separating partial flows from the air flow, deflecting them to the outside. Experience has shown that a steady air discharge is achieved even on relatively long tube sections even if the scoops are of the same size. On the other hand this, however, does not exclude that the air discharge may also be influenced by unevenly sized scoops.

The scoops may conveniently be arranged along a surface line. This is advantageous if the air tube is intended to discharge only in one lateral direction. However, the scoops may also be distributed about the periphery of the tube.

The special advantage of the invention is obtained if the scoops are provided on a flexible tube. In this case, the air tube may be prefabricated, with the scoops, in any desired length and marketed in roll form. To install the tube, it would only be necessary to cut off the required tube lengths; this is why this air tube is particularly suitable for caravan air distribution systems.

The invention is best carried out with a tube having a round cross-section. From the -flow-technique point of view, the scoops are very favourable since they separate, with the inner edges projecting blade-like into the interior, a partial flow from the main flow, which partial flow is then gradually deflected to the outside by the scoop. Since the inner surface of the scoop may also extend in a streamlined manner, the reduced air flow is then able to re-expand to the full cross-section in the tube without any flow turbulences occurring. Since there is no baffle wall present, the air flow in the inside of the tube is not impaired by the scoops.

If the air is being laid as a tap line, it may be sealed off at its free end by means of a plug, or with a nozzle end plus additional plug, e.g. of plastics. Preferably, the nozzle end has an inclined outlet so that the vehicle corners affected by dampness and cold are swept intensively.

A particularly advantageous layout of the air tube in a caravan is achieved if it branches off from a main air duct of an air distribution system and is laid as a tap line underneath a seat board in the inside of a bedding box, along a caravan wall. In this case, a Y-piece equipped with a regulator valve, appropriately serves as a connector for the air tube.

Clamps which span both tubes and hold them together are advantageously used for fixing the tubes to the vehicle wall. This results in a compound arrangement which permits the prefabrication of complete strings in batch production.

Further characteristics and details of the invention can be seen from the following description of an embodiment which is represented in the drawings, wherein: Fig. 1 represents a longitudinal section through one end of a flexible air tube; Fig. 2 represents a cross-section thereof; Fig. 3 represents a section through a schematized caravan seat with an air tube laid in this seat; Fig. 4 represents a side view of an air tube branched off from a main air duct, and Fig. 5 represents a section taken on line V-V of Fig. 4.

Scoops 2 are formed at predetermined distances on an air tube 1, e.g. a flexible aluminium tube with standard tube wall pleating. For this purpose, a tube wall 3 is slightly cut at a predetermined place and the separated wall section is then pressed inwards synclinically. This produces a discharge aperture 4 in the radial plane. On the outside this is bound by an outer edge on the tube wall 3 and in the inside by an inner edge 5 on an end of the scoop 2. These scoops project into the tube cavity 6 and act like spoon-like scoops which, in the inside of the tube, -separate a partial flow from the passing air flow and lead this to the outside. A scoop 8 gradually merging into the tube wall 3 pre vents the occurrence of a noticeable flow re sistance.The non-deflected main air flow which continues to move in the tube interior is also conveyed without any turbulence into the whole cavity cross-section by the inner surface 9 of the scoops which is also streamlined, until another partial flow is branched off to the outside at one of the following apertures. In this way, partial flows of approximately even intensity escape from an air tube of any length according to the available discharge apertures. Normally, the scoops 2 will be arranged along a surface line.

However, under special circumstances it may be appropriate to arrange these scoops in a radial pattern. The scoops which may be developed on any tube of round or polygonal cross-section, prove to be of particular advantage on a flexible tube which can be rolled up. Tube sections of any length can be cut off from these tube rolls and then be installed. In general, the connection of these air tubes to a main air duct is carried out by means of a simple plug-in connection. If the air tube is laid as a tap line, a Y-piece 15 is fitted into the main air duct at a branch-off point (Fig. 4), to which the air tube is connected. Appropriately, a regulator valve 16 is fitted in the Y-fitting. Fig. 3 represents in a diagrammatic view the laying of an air tube 1 as a branch-off from a main air duct 20.Whilst the main air duct 20 is run along an outside wall 21 of a caravan through the available bedding boxes, the air tube 1 is run as close as possible underneath a seat 22 of a bedding box. Discharge points of the air tube are directed upwards into a backwall gap 23 in which the air escaping from the tube rises above the seat back 24 and into the living room. Advantageously, each caravan wall should be provided with such a tap line.

The cheap and simple manufacture as well as the easy and adaptable installation of the air tube does not result in any additional elaboration, but in a better distribution and supply of air.

The branched-off air tube 1 is held together with the main air duct 20 by means of double tube clamps 25 and is fixed to the wall at the same time. This clamp consists of a clamp ring'26 embracing the air tube 1, the arms of which form a subsequent clamp collet 27 for holding the main air duct 20 and finally end in bored fixing tips 28 which can be placed on top of each other. Between the clamp ring 26 and the clamp collet 27, the clamp arms form a constriction 29 which safeguards the elasticity and the clamping effect of the clamp as well as the distance between the two tubes.

At its free end, the air tube can either be sealed off by means of a plug or by the fitting of an exhaust nozzle 12 with plug or cam (Fig. 1). The exhaust nozzle, which is only slid onto the air tube, advantageously has an inclined nozzle end 13 which for example considerably improves the corner ventilation.

The scoops may be angular or corrugated in their cross-section. At the end of an air tube, an enlarged scoop could completely or partly replace the exhaust nozzle. In the same way, the scoops can be used on other rigid or flexible metal or plastic tubes of round or polygonal cross-section.

WHAT WE CLAIM IS 1. An air distribution tube having at intervals in the longitudinal direction a plurality of air outlet apertures, each aperture being bounded by (a) an outer edge at the periphery of the tube and (b) an inner edge on an end of a respective air scoop which is integral with the remainder of the tube and which extends from said inner edge to a position, spaced longitudinally from said edge, where it merges into the periphery of the tube, the outer and inner edges being spaced in a direction which is substantially normal to the longitudinal direction of the tube.

2. An air distribution tube, as claimed in claim 1, wherein the air scoops are arranged in a line along the tube.

3. An air distribution tube, as claimed in claim 1, wherein the air scoops are distributed about the transverse periphery of the tube.

4. An air distribution tube, as claimed in any one of the preceding claims, which is flexible to the extent to enable it to be formed into a roll.

5. An air tube, as claimed in any one of the preceding claims, in combination with an exhaust nozzle engaged with an end of the tube, the exhaust nozzle having an outlet the axis of which is inclined with respect to the longitudinal direction of the portion of the tube with which the nozzle is engaged.

6. An air distribution system wherein a tube, according to any one of claims 1 to 4, is branched off from a main air duct of an air distributor, and is laid as a tap line adjacent to the main air duct along a caravan wall.

7. An air distribution system, according to claim 6, wherein the tube is laid inside a bedding box underneath a seat board with its discharge points directed into a backwall gap.

8. An air distribution system, according to either of claims 6 and 7, wherein the air tube and the main air duct are held together and fastened by means of a double tube clamp.

9. An air distribution system, according to claim 8, wherein the double tube clamp consists of resilient clamp strap arms forming a clamp ring for the air tube, a clamp collet for the main air duct, and a construction provided in between.

10. An air distribution tube, as claimed in claim 1, substantially as described herein with reference to Figs. 1 to 3 of the accompanying drawing.

11. An air distribution system, as claimed in claim 6, substantially as described herein with reference to the accompanying draw ings:-

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. tube, an enlarged scoop could completely or partly replace the exhaust nozzle. In the same way, the scoops can be used on other rigid or flexible metal or plastic tubes of round or polygonal cross-section. WHAT WE CLAIM IS

1. An air distribution tube having at intervals in the longitudinal direction a plurality of air outlet apertures, each aperture being bounded by (a) an outer edge at the periphery of the tube and (b) an inner edge on an end of a respective air scoop which is integral with the remainder of the tube and which extends from said inner edge to a position, spaced longitudinally from said edge, where it merges into the periphery of the tube, the outer and inner edges being spaced in a direction which is substantially normal to the longitudinal direction of the tube.