EP3489455B1 - Extending push ladder for fire fighting made from composite material - Google Patents

Description

Technical area

The present invention describes an extension ladder for fire service use made of composite materials with at least a first and second ladder part, comprising first and second spars to which several rungs are attached along a longitudinal axis running transversely to the spars, with spars and rungs comprising carbon fiber laminates consisting of several carbon fiber layers , which completely surround the components and are permanently attached using a resin.

State of the art

Ladders with a plurality of rungs, which are fitted into two spars on both sides, have long been known for various possible uses. What is of interest here are extension ladders, preferably extension ladders, which can be used as extension ladders with two or three ladder parts that can be moved relative to one another, especially for fire brigade operations.

While in the past it was assumed that the fire brigade would only use rescue vehicles with mobile and rotating fire escapes, so-called turntable ladders, to access higher-up apartments, this is now partly being abandoned. The dense construction is increasingly making access more difficult and the limited load-bearing capacity of the ground due to underground car parks etc. further restricts the area of application of these heavy vehicles, so that the fire brigade is increasingly using extension ladders in the form of manual extension ladders as elementary rescue equipment.

These manual sliding ladders, which can be extended up to 15 meters and where the ladder parts can be pulled apart with a pull rope, must of course be sufficiently stable, as fire-resistant as possible, easy to set up and also as handy as possible. For the deployment of rescue workers, EN DIN 1147 should be mentioned in this context

In classic production, mainly wood and aluminum were used, resulting in a total weight of a three-part hand sliding ladder of around 120 kg for wood and around 85 kg for aluminum. Such a hand-held sliding ladder can just about be described as handy. Depending on the fire brigade's guidelines, the well-known extension ladders must be set up by four fire brigade members.

It has long been known that ladders can and should be made partly from carbon fibers or from composite materials with carbon fiber material, primarily in order to reduce the overall weight of the ladder. This means that the weight of hand sliding ladders could be reduced significantly, sometimes by half, compared to classic materials such as wood and aluminum.

In the AU2017202064 Ladder parts made of fiberglass spars and one-piece rungs made of a composite material with carbon fibers are described. The rungs are hollow and are attached to the bars using rivets. Basically, the rungs are designed with a collar on both sides, through which the connection to the bars takes place. The structure of the ladder parts made of fiberglass and carbon fiber composite material is similar to a classic profile-like structure. This means that the resulting ladder part is probably lighter than classic ladder parts made of wood or aluminum. However, the described ladder made of composite material is not designed as a pull-out extension ladder and would have to have, among other things, a pull rope mechanism.

Instead of an extendable extension ladder, the GB2530710 Another lightweight ladder is described, which instead consists of several ladder parts that can be plugged together. The rungs and bars of each ladder part are made of carbon fibers, with the rungs being rectangular in cross section and tubular. The ladder parts are made in one piece, so there is no need to attach rungs to the bars. Here, ladder parts would have to be manufactured with different spacings between the bars, which would have to be plugged into one another and then converted into an extendable extension ladder using a pull cable mechanism. There are no further extension ladders made of composite material known from the prior art.

Classic extension ladders made of metal or wood have certain disadvantages for fire service use and cannot be recreated 1:1 from composite materials. The classic metal pull-out ladders usually have isolated brackets on a base ladder part, which is arranged on one side of a spar and is pushed over a spar of a second ladder part. The bracket has a guiding and holding function between the ladder parts. This design with a bracket leads to an unfavorable application of force when attaching the bracket and during later use in pull-out extension ladders made of composite material. The spars then break at the positions of the brackets, which is why this route is not viable for composite materials. Known disadvantages of wooden extension ladders are the high weight, the limited durability of wood and the lower load capacity, in accordance with test specifications EN 1147.

Transporting, extending and generally setting up a wooden extension ladder requires at least four people and requires an enormous amount of effort. Aluminum extension ladders are tricky due to their electrical conductivity, especially when used near overhead lines and trams, and the strength of Aluminum degrades dramatically at higher temperatures as the metal softens.

Extension extension ladders made of composite material, in particular comprising carbon fiber laminates or carbon fiber layers, are very interesting for fire service use, lead to lightweight extension extension ladders and should be used more frequently.

However, there are no other lightweight, robust extension ladders made of composite material available for fire brigade use with sufficient guidance, which can be used by fire brigade members in particular when operating in high temperatures, under precarious visibility conditions and in heavy smoke. There are composite extension ladders primarily in the area of high-current applications, according to high-voltage testing for ladders made of insulating material according to DIN EN 61478 or VDE 0682. Composite profiles and fittings with sliding guides and/or rollers are usually used here. However, these systems are by no means comparable to fire department ladders in terms of load capacity and length. It is also not yet clear how the long-term load capacity of an extension ladder can be increased with ladder parts made of carbon fiber layers, so that as many extension and insertion processes as possible are possible without damaging the ladder part.

From the US3502173 is a pull-out sliding ladder made of composite materials with two ladder parts, comprising first and second spars to which several rungs are attached along a longitudinal axis running transversely to the spars. Holes and rungs can comprise several laminate layers, which are permanently attached using a resin. To enable the extension ladder to be telescopic, metal fittings are provided on the bars.

In the WO 0136780 A1 an extendable ladder, according to the preamble of claim 1, is described with hollow bars on which guide slides are molded.

Presentation of the invention

The present invention has set itself the task of creating an extension ladder for fire service use or use in fire departments and rescue services, comprising several ladder parts made of spars and rungs made of composite material or carbon fiber laminates, which is light and robust and ensures improved linear extension and insertion. The stability of the extension ladder should be increased without attacking the carbon fiber laminates.

This task is solved by a pull-out extension ladder with specially shaped ladder parts according to claim 1, whereby additional brackets, in particular made of non-composite material, are dispensed with.

The pull-out extension ladders of interest here in the form of a hand extension ladder should be fireproof and as light as possible, which is why they are made from carbon fiber laminates. With high load-bearing strength and minimal weight, a high level of user-friendliness is achieved, especially with regard to the ability to set up and extend and retract the extension ladder.

Brief description of the drawings

Figur 1

zeigt eine perspektivische Ansicht einer Auszugschiebeleiter aus Verbundwerkstoffen, umfassend zwei Leiterteile in ausgezogenem Zustand.

Figur 2

zeigt eine Seitenansicht der Handschiebleiter im Bereich in zusammengeschobener Stellung mit Überlappung beider Leiterteile, während

Figur 3

die in Figur 2 gekennzeichnete Detailansicht des Nut-Feder-Systems der beiden Leiterteile zeigt.

Figur 4

zeigt eine perspektivische Ansicht einer teilweise ausgezogenen Handschiebleiter im Überlappungsbereich zweier Leiterteile.

Figur 5

zeigt eine teilweise geschnittene Detailansicht gemäss Figur 2 des Nut-Feder-Systems mit dem inneren Aufbau der Holme.

A preferred embodiment of the subject matter of the invention is described below in connection with the accompanying drawings.

Figure 1

shows a perspective view of an extension ladder made of composite materials, comprising two ladder parts in the extended state.

Figure 2

shows a side view of the manual sliding ladder in the area in the pushed-together position with both ladder parts overlapping, while

Figure 3

in the Figure 2 marked detailed view of the tongue and groove system of the two ladder parts.

Figure 4

shows a perspective view of a partially extended manual sliding ladder in the overlap area of two ladder parts.

Figure 5

shows a partially sectioned detailed view according to Figure 2 the tongue and groove system with the internal structure of the spars.

Description

An extendable sliding ladder is presented in the form of a multi-part manual sliding ladder, which comprises a plurality of ladder parts 0, 0', which can be displaced relative to one another with a pull rope mechanism comprising a pull rope. As is known from the prior art, drop hooks are also provided in the pull rope mechanism, which prevent the ladder parts 0, 0' from being retracted inadvertently, and an optional rope brake can be arranged.

The ladder parts 0, 0 'each consist of two bars 1 to which several rungs 2, running transversely to the bars 1, are attached along a longitudinal axis L. The spars 1 have an inner spar surface 10, an outer spar surface 11 and two spar end walls 12. The outer layer of the spars 1 and the rungs 2 is formed by a composite material laminate, preferably carbon fiber laminate 3. The spars 1 and the rungs 2 are preferably completely surrounded by the carbon fiber laminate 3 in several layers.

To increase the stability of the spars 1, spar reinforcing ribs are provided, which can run parallel to the longitudinal axis L on the spar outer surfaces 11 and/or the spar end walls 12. The spar reinforcement ribs also serve as wear protection for the ladder parts 0, 0'. A ladder base, not shown here, is pivotably attached to the lowest ladder part 0 ', which stands on the ground during use.

The rungs 2 or their longitudinal axes S run perpendicular to the bars 1 or their longitudinal axes L. The rungs 2 have a surface which is formed by a rung tread surface 20 pointing upwards in the set-up state, a rung underside 21 opposite the rung tread surface 20 and side surfaces 22 becomes.

The first conductor part 0 and the lower second conductor part 0 'are mounted so that they can be moved linearly relative to one another in the direction of the longitudinal axis L. Excerpt and indent are marked with the double arrow in Figure 1 indicated.

The ladder sub-components, i.e. bars 1 and rungs 2, are each made in one piece and are individually glued together, whereby the ladder parts 0, 0 'are formed. The spars 1 and rungs 2 are connected to each other using a modular principle, so that individual spars 1 and rungs 2 can be replaced if damage occurs. At the terminal rung end faces 23, the rungs 2 are connected to the bars 1 in the direction of the longitudinal axes S of the rungs.

As in Figure 2 It can be seen that the first ladder part 0 has a distance d between the bars 1 and thus rungs 2 with a rung length d and the second ladder part 0 'has a distance D between its bars 1' and thus the rungs 2' of the second ladder part 0' Rung length D. Both ladder parts 0, 0' can be pushed into each other in the longitudinal direction L so that the extension ladder is ready for use.

In order to ensure guidance of the two ladder parts 0, 0' during linear movement, the bars 1, 1' are specially designed so that a guidance system in the form of a tongue and groove system is achieved.

Along the bars 1 of the first ladder part 0, the end region of the bars 1 facing the second ladder part 0 'is cranked. The bend of the end area points away from the center P of the rung 2 and from the outer surface of the rail 11. In the cross section, a nose N is formed, which points outwards, away from the spar 1 and the rung center P.

Analogously, the bars 1' of the second ladder part 0' also have cranked end regions, but these end in the direction of the rung centers P are cranked and thus directed towards the adjacent spar 1 'of the same ladder part 0'.

Due to the cranked end region along the spar 1', a guide groove F is formed on the second ladder part 0' between the cranked end region and the rungs 2' running parallel to the formed nose N' or the side surfaces 22' of the rungs 2'. This guide groove F preferably runs along the entire length of the bars 1', which is why the entire end region of the bars 1' is designed to be cranked.

The end regions of the first spars 1 and the second spars 1 'are designed to be cranked along their entire length in the direction of the longitudinal axis L. This creates a tongue-and-groove system between the first and second conductor parts 0, 0' and the bent end of the first spar 1 or the nose N forms a guide spring which runs in the guide groove F. Both conductor parts 0, 0' are thus linearly movable in the direction of the longitudinal axis L, while they are positively connected to one another in the direction perpendicular to the longitudinal axis L and tilting or loss of a conductor part 0, 0' is prevented. The guide in the direction of the longitudinal axis L is guided and secured by the tongue and groove system. This means that the ladder parts 0, 0' are captively secured when pulled apart and pushed in.

The noses N, N' or cranked end regions of the bars 1, 1' are here designed to run approximately parallel to the longitudinal axis S of the rungs. In other embodiments, the orientation of the lugs N, N' may differ slightly.

In order to increase the strength or rigidity of the rung 2, at least one reinforcing rib 24, 24 'can be arranged parallel to the longitudinal axis S of the rung. A reinforcing rib 24 is preferred on each rung surface, the rung tread surface 20, the underside of the rung 21 and when using a house wall or a fire brigade member facing side surfaces 22, 22 '. The arrangement of reinforcing ribs 24 allows the individual conductor parts 0, 0' to be gripped better, which increases user-friendliness.

The spars 1, 1' with their cranked end regions or noses N, N' have an L-shape in cross section at least in sections, the spars 1, 1' being completely surrounded by carbon fiber laminate 3.

Since the ladder parts 0, 0' do not just rest at points along the longitudinal axis L, a load is transferred over a large area in the overlapping area of the ladder parts 0, 0' and stabilization is the result. The overlapping area is in Figure 4 shown in dashed lines. Once the conductor parts 0, 0' are threaded into the tongue and groove system, a load is transferred over a large area, with the linear, approximately parallel guidance of the two conductor parts 0, 0' being optimized. The ladder parts 0, 0' comprising carbon fiber laminate 3 are thus protected and more stable ladder parts 0, 0' can be achieved since there are no additional holes or screw connections to which holding and guide brackets have to be attached.

The conductor parts 0, 0' are made exclusively of composite material, with carbon fiber laminates 3 made of several carbon fiber layers preferably being used in some cases. The spars 1, 1' and/or the rungs 2, 2' could also be made entirely from carbon fiber laminates 3.

In terms of manufacturing technology, it is easier to form the spars 1, 1 'from at least one core 4, around which several carbon fiber layers are glued using laminating resin, so that the carbon fiber laminate 3 is formed as reinforcement. According to the invention, the core 4 is within the first spar 1, more precisely within a longitudinal spar body, which is board-like with a constant cross-sectional area is designed, arranged. The carbon fiber laminate 3 or several carbon fiber layers completely envelop the core 4, which is shown schematically in Figure 5 is shown.

Two cores 4, 4' surrounded by carbon fiber layers can also be arranged in the spars 1, 1 '. These cores 4, 4' are completely covered with carbon fiber laminate 3, which can be seen using the example of the second spar 1' in Figure 5 is indicated.

The spars 1, 1' are formed in one piece and comprise a first core 4 and a second core 4' arranged at an angle thereto, which forms a nose N, N' or is arranged running within the nose N, N'. The cores 4, 4' are completely covered by carbon fiber layers, so that a longitudinal spar body and a nose N, N' are completely covered with carbon fiber layers.

The cores 4, 4' are formed from the foam material made of a plastic, which is designed to be self-supporting with a large number of air holes. The light yet stable plastic foam forms the interior of the bars 1, 1 'and is mechanically reinforced by the carbon fiber laminate 3 and the foam material is protected against external influences. The result is a robust and yet light spar 1, 1 'or rungs 2, 2' if these are designed with an inner core 4.

The individual carbon fiber layers usually comprise a web of threads, with the threads being made from thousands of individual filaments. The type of fabric can be plain weave or body weave, for example. The resulting carbon fiber layers have different weights per unit area and strength due to the threads used and the type of binding and are tailored to the sizes of the spars 1, 1' and rungs 2, 2'. Individual carbon fiber layers are relative rotated in relation to each other, layered on top of each other and inextricably connected to each other. Since it is clear to those skilled in the art in which directions which forces act, the exact orientation of the carbon fiber layers will not be discussed further here. If a core 4, 4' is used, the carbon fiber laminate 3 completely surrounds the core 4, 4'. Since the carbon fiber laminates 3 of the rungs 2, 2' and the spars 1, 1' do not overlap, each component can be further processed individually or connected to other components.

The individual rungs 2, 2' are firmly glued to the bars 1, 1' and are thus materially connected, whereby a permanently stabilized connection is achieved.

The reinforcing ribs 24 can already be indicated on the core 4 and then covered with carbon fiber layers. However, it is also possible for reinforcing ribs 24 to be molded into the laminated surface of the components before a curing process, in particular a baking process, and for these reinforcing ribs 24 to be fixed during the baking process when the laminating resin hardens.

Claims (10)

1. Pull-out extension ladder for fire fighting purposes made of composite materials with at least a first and second ladder part (0, 0'), comprising first and second stiles (1, 1') to which a plurality of rungs (2, 2') are attached along a longitudinal axis (L) extending transversely to the stiles (1, 1'), wherein stiles (1, 1') and rungs (2, 2') comprise laminates (3) consisting of a plurality of laminate layers, which completely surround the components and are non-detachably attached by means of a resin, wherein a tongue and groove system is formed extending completely along the stiles (1, 1') in direction of the longitudinal axis (L), formed by integrally formed cranked end portions along the first stiles (1) and integrally formed cranked end portions along the second stiles (1'), so that a secured and guided linear relative movement of the first ladder part (0) to the second ladder part (0') in direction of the longitudinal axis (L) is achievable when using a pull-rope mechanism, characterized in that within the stiles (1, 1') at least one core (4) is arranged, which is shaped board-like with constant cross-sectional area, completely enveloped in a composite laminate.
2. Pull-out extension ladder made of composite materials according to claim 1, wherein the individual rungs (2, 2') are glued materially bonded to the stiles (1, 1').
3. Pull-out extension ladder made of composite materials according to any one of the preceding claims, wherein the laminates (3) of the rungs (2, 2') and the stiles (1, 1') do not overlap.
4. Pull-out extension ladder made of composite materials according to claim 1, wherein the end portion of the first stiles (1) of the first ladder part (0) are cranked away from a rung center point (P) of the rungs (2) and from a rung outer surface (11), so that a cranked away nose (N) is formed in cross-section.
5. Pull-out extension ladder made of composite materials according to claim 4, wherein the end portion of the second stiles (1') of the second ladder part (0') is cranked towards the rung center point (P) of the second rungs (2') in direction of the neighboring second stile (1'), so that a guide groove (F) is formed between a nose (N') rising parallel to the second rungs (2') and a lateral surface (22') of the second rungs (2').
6. Pull-out extension ladder made of composite materials according to claim 5, wherein the first ladder part (0), in an area of the cranked nose (N) lying in the guide groove (F) of the second ladder part (0'), is linearly displacable somewhat parallel relativ to the second ladder part (0') along the entire length of the first stiles (1) in direction of the longitudinal axis (L).
7. Pull-out extension ladder made of composite materials according to any one of the preceding claims, wherein a rung length (d) of the first ladder part (0) is chosen smaller than a rung length (D) of the second ladder part (0').
8. Pull-out extension ladder made of composite materials according to any one of the preceding claims, wherein the stiles (1, 1') with their cranked end portion have an L-shaped cross-section and are completely surrounded by carbon fiber layers.
9. Pull-out extension ladder made of composite materials according to claim 8, wherein the stiles (1, 1') are formed in one piece and from a core (4) made of foam material, the core (4) being completely enveloped in carbon fiber layers in a multilayer manner.
10. Pull-out extension ladder made of composite materials according to claim 9, wherein the stiles (1, 1') are formed in one piece and comprise two cores (4, 4') made of a foam material, wherein one core (4) runs within a longitudinal stile body and the second core (4') runs within the nose (N, N') while both cores (4, 4') are completely enveloped in carbon fibre layers.

Images