DE102023112162A1 - Director - Google Patents

Abstract

Ladder, with an upper ladder (2), a middle ladder (4) and a lower ladder (6), each of which has ladder bars (14, 16, 18 and 20) and several steps that are designed as steps or rungs, the ladder bars ( 14, 16, 18 and 20) each have a retaining bracket (22, 24, 26 and 28), each middle conductor retaining bracket (22, 24) having an upper conductor spar (10, 12) and each lower conductor retaining bracket (26, 28) having a central conductor spar (14, 16) and wherein the upper ladder (2) is mounted displaceably against the middle ladder (4) and the middle ladder (4) is mounted on the lower ladder (6) both displaceably and pivotably, characterized in that the upper ladder (2) has a work area which comprises at least 2 steps (40), and that when the ladder (1) is extended, a step (38) of the middle ladder (4) is at the same step height as a step (40) of the upper ladder (2), and whereby in this state there is a free space (66) between these steps (40) of the upper conductor (2) and the adjacent steps (38) of the middle conductor (4) at the same step height, which is 18 mm or more.

Description

The present invention relates to an extendable ladder according to the preamble of claim 1.

Ladders in the form of leaning ladders have been known for a long time. An example of this is the one from the publication US 2,876,047 A1 known solution. This ladder has an upper ladder attached to a lower ladder, and quite tightly. The spars of the upper ladder extend over a smaller width than the spars of the lower ladder. In addition, the upper ladder is guided on the lower ladder on the side facing the user.

Lower ladders are often used for climbing, i.e. as a traffic route, and the upper ladder is intended for the user to stand there to carry out work. To make the work easier, see the publication US 2,876,047 A1 a step attachment that can be attached to the upper ladder.

Furthermore, it has also become known to equip extendable ladders completely with steps, including the lower ladder. This allows comparatively secure footing even on the lower ladder. However, a full-step ladder is almost twice as heavy as a full-rung ladder, which accordingly greatly reduces acceptance.

When handling, the extension ladder is typically pushed out in such a way that the user grabs a rung or step of the upper ladder with one hand and pushes the upper ladder with its steps or rungs upwards until it is locked into place or at least until it is leaning against the wall which the ladder is to be used is possible. Extendable ladders must always be leaned against a wall before use. Such ladders are also known as leaning ladders.

Stand ladders that are extendable have also become known. An example of this is the one from the publication EP 1 607 570 A2 well-known leaders. This can be used as a standing ladder or extended as a leaning ladder. At the one from the publication EP 1 607 570 A2 Well-known ladders can be attached to steps in the work area. This solution did not prevail. The step attachments require you to carry many individual parts.

In contrast, the invention is based on the object of creating a ladder according to the preamble of claim 1, which can be used in a variety of ways, increases acceptance and is still comparatively easy and safe to handle.

This object is achieved according to the invention by an object according to claim 1. Technically advantageous embodiments are the subject of the dependent claims, the description and the drawings.

According to the invention, it is intended to design the conductor in three parts, i.e. consisting of an upper, middle and lower conductor. The upper ladder is narrower than the middle ladder and this in turn is narrower than the lower ladder. In the plan view, the spars of the upper conductor and the middle conductor and those of the middle conductor and the lower conductor are offset from one another. These three conductor parts are connected to each other in such a way that the upper conductor is guided on the middle conductor and the middle conductor is guided on the lower conductor.

The individual ladder parts have ladder bars and several steps, some of which are designed as steps and others as rungs. According to the invention, the upper ladder has steps at least in the work area, preferably only in the work area.

In the side view of the ladder, the bars of the upper, middle and lower ladders are not congruent, but are offset from one another but overlap one another. The upper ladder spars rest on the treads of the middle ladder and the middle ladder spars on the treads of the lower ladder. The spars of the upper ladder thus extend within and offset against the spars of the middle ladder and these in turn extend within and offset against the spars of the lower ladder.

The conductor parts can be moved relative to one another in a manner known per se, but only to the extent that adjacent conductor parts are supported on one another. If a ladder were to be extended too far, this would lead to instability and thus endanger the user. It must therefore be prevented that the ladder is pulled out so far that instabilities arise between the ladder parts or that the ladder can be unintentionally dismantled into the individual ladder parts. For this purpose, a pull-out lock is provided in a manner known per se. At the maximum length of the ladder, i.e. when the ladder is fully extended, there is a transition area in which the ladder parts, i.e. on the one hand the upper and middle conductors and on the other hand the middle and lower conductors, overlap. This transition area is preferably set in such a way that stability is guaranteed, but high working heights can still be achieved.

The lower ladder stands in a manner known per se on a traverse which is attached to its lower end in the manner of a crossbeam.

According to the invention, the individual ladder parts are attached to one another using special holding brackets guided. The retaining brackets that connect the center conductor and the top conductor are mounted on the center conductor bars. These retaining brackets are preferably attached to each center conductor spar in the area of the top quarter of the center conductor. They each include or encompass an upper ladder spar and are equipped with sliding elements on their inner end faces in order to enable the middle conductor and upper conductor to slide or slide against each other.

The retaining brackets that connect the lower conductors and the middle conductors are mounted on the lower conductor bars. These retaining brackets are preferably attached to each lower ladder spar in the area of the upper quarter of the lower ladder. These holding brackets are particularly designed in such a way that, in addition to the sliding or sliding mobility of the middle conductor and upper conductor, they also alternatively enable pivoting mobility of these two ladder parts. These retaining brackets also partially surround the bars, here the two center conductor bars, and are equipped with sliding elements on their inner faces. However, in this case, the retaining brackets only encompass the front part of the middle conductor spars, i.e. the part of the spar that lies on the side of the upper ladder, but not the rear part of the middle conductor spars, i.e. the part of the spar that lies on the side of the lower ladder. This makes it possible, on the one hand, to move the lower conductors and middle conductors relative to one another, and, on the other hand, to pivot these two conductor parts relative to one another. The hypothetical joint axis is thus formed in the area of the holding bracket, which lies centrally between the lower and middle conductors.

The pivoting mobility, on the other hand, makes it possible to use the ladder according to the invention in the sense of a stepladder or trestle ladder. In this method of use, the lower conductors and middle conductors serve to ensure that the ladder stands freely. In order to prevent the conductors from unintentionally spreading, the lower conductors and the middle conductors are connected with a chain, a bracket or a tear-resistant band or a differently designed anti-spreading device.

When used in this way, the upper ladder can still be extended along the middle ladder in order to reach higher work areas without having to put the ladder on.

According to the invention, the upper steps of the upper ladder, for example the top three steps of the upper ladder, are designed as rungs.

In an advantageous embodiment, the upper steps of the upper ladder and the lowest step of the upper ladder and all steps of the middle and lower ladders are designed as rungs. The remaining steps of the senior ladder, i.e. the ladder's work area, are designed as steps. This means that the additional weight of the steps can be kept comparatively low.

1. 1. Sprosse
2. 2. Sprosse + Sprosse
3. 3. Stufe + Sprosse
4. 4. Stufe

When extended, i.e. when using the ladder as a leaning ladder, the lowest rung of the upper ladder is at the same height as a rung of the middle ladder. By arranging these two rungs at the same height and the distance between these rungs, which can be between 18 and 45 mm, for example, the effect of a step is created. Overall, when all three ladder parts are fully extended, i.e. when using the ladder as a leaning ladder, the transition from the top ladder to the middle ladder from bottom to top can look like this:

1. 1st rung
2. 2. Rung + Rung
3. 3rd step + rung
4. 4th stage

In the transition area between the ladder parts - viewed from bottom to top - there are two rungs and above them a rung and a step, each at the same step height. Step height refers to the height that must be overcome in order to climb up a step. Furthermore, the step height can also be described as the distance between two steps along a rail of the ladder.

1. 1. Sprosse der Mittelleiter
2. 2. Sprosse der Oberleiter + Sprosse der Mittelleiter
3. 3. Stufe der Oberleiter + Sprosse der Mittelleiter + Sprosse der Unterleiter
4. 4. Stufe der Oberleiter

When using the ladder as a standing ladder with the upper ladder extended, the sequence of steps is as follows:

1. 1st rung of the middle ladder
2. 2nd rung of the upper ladder + rung of the middle ladder
3. 3rd step of the upper ladder + rung of the middle ladder + rung of the lower ladder
4. 4th step of the senior ladder

Even in this use, the lowest rung of the upper ladder is at the same height as a rung of the middle ladder. The tops of these two rungs, which are at the same height, preferably form a flat tread surface. This creates the effect of a step. The tread surface of this hypothetical step runs essentially parallel to the steps arranged above it and essentially perpendicular to the bars.

In the transition area of the ladder parts - viewed from bottom to top - there are two rungs and above them two rungs and a step each on the same level cher step height. Even when using the ladder in this way, there is a harmonious transition from rung to step, which increases the user's feeling of security. There is a harmonious transition from rung to step, which increases the user's feeling of security.

According to standards, the top 3 rungs of the upper ladder may at least not be used as a work area. Therefore, as described above, according to the invention they are designed as a rung, i.e. as a traffic area. This implementation can be easily combined with exit bars in particular. For example, exit bars can be attached as screw-on additional parts to the upper area of the upper ladder bars. The design of the top three steps of the upper ladder as rungs allows such exit bars to be easily attached to the upper ladder spars, since the contact point of a rung with the respective spar takes up less area than the contact point of a step. This design therefore leaves more space on the bars, making it easier and more stable to attach exit bars. These exit bars can, for example, be mobile, for example as clip-on parts or as additional parts for screwing on, and can only be attached to the upper parts of the upper ladder bars when necessary.

Preferably, a backdrop is provided for guiding the upper ladder on the middle ladder and/or for guiding the middle ladder on the lower ladder. The backdrop can be designed in one piece or in several parts and attached to a spar of a ladder part. In a two-part or multi-part design, one part of the backdrop is attached to a spar, for example an upper or middle ladder spar, and another part or several other parts is attached to an adjacent spar, for example a middle or lower ladder spar. The backdrop is designed so that in the one-piece design it interacts either with the steps and/or the rungs of an adjacent ladder rail or, in the multi-part configuration, with its counterpart or counterparts on the adjacent ladder rail.

In the case of the multi-part backdrop, the first backdrop part can, for example, be designed similarly to the one-piece backdrop and the second backdrop part can be designed as a metal strip or as several metal plates on the adjacent ladder rail, with which the first backdrop part - instead of the steps and / or rungs - interacts.

Due to its geometric shape in combination with its fixed position on a ladder spar, or its fixed positions on two adjacent ladder spars in the case of a multi-part design, i.e. at fixed positions on the upper conductor and middle conductor spar or at fixed positions on the middle conductor and lower ladder spar, the Make sure that the minimum distance between a step on the upper ladder and a rung on the middle ladder and/or the distance between a rung on the middle ladder and a rung on the lower ladder is maintained. The geometric shape of the backdrop can be adapted to the requirements.

The interaction of the link with the steps or rungs or the second link part on the adjacent ladder part makes it possible for a minimum distance between a step of the upper ladder and a rung of the middle ladder and/or between a rung of the middle ladder and a rung of the lower ladder, is not less than 18 mm. When the ladder is pushed out, the backdrop acts as a spacer. This is illustrated here using the example of a one-piece backdrop between the upper and middle ladder, but also applies to the function of the backdrop between the middle and lower ladder and also for two-part backdrops.

As already mentioned above, the spars of a ladder part, here for example the upper ladder spars, lie within and offset against the spars of the adjacent ladder part, here the middle conductor spars, and rest in particular on the treads of the adjacent ladder part, here the middle conductor. Since the adjacent conductor parts, here the upper and middle conductors, are guided closely together, the distance between the treads of adjacent conductor parts when pulled out is only a few millimeters, in particular between 45 and 18 mm.

For example, if the upper ladder is pulled out, if no link is attached, a user could get their fingers caught between a step and a rung or between two rungs of different ladder parts. The backdrop prevents this because its geometric shape prevents a step from coming close to a rung or between two rungs of different ladder parts. It is advantageous that, particularly in the case of ladders that are completely provided with steps, the geometric shape of the link prevents two steps of adjacent ladder parts from coming close. Coming close means that the prescribed minimum clearance, i.e. the minimum distance between steps or rungs of 2 ladder parts that are moved along each other, would be at least 18 mm below the prescribed minimum clearance. The minimum free space runs in a horizontal direction. If 2 steps or rungs move past each other when the ladder is pulled out, the backdrop creates a minimum vertical or diagonal distance between them Two rungs of the ladder parts and/or a rung and a step, but also between two steps, are ensured. This reliably prevents the user's fingers from being trapped or crushed when taking it off. In the case of a one-piece backdrop, the backdrop can run at an angle, i.e. be designed as a slope. It is attached to one part of the ladder and acts against a step or rung of the other part of the ladder. It leads the other part of the ladder away from one part of the ladder and increases the horizontal distance between adjacent steps or rungs of the two parts of the ladder. The tip of the slope preferably points upwards. A one-piece link can also have a metal plate with a horizontal area that points from one conductor part to the adjacent conductor part and a vertical area that points upwards. This will be further explained below.

When pulled out, the upper area of the backdrop, for example at a tip of a slope or an oblique-vertical structure, abuts against a step of the other ladder part if the distance between the step/rung and the rung/step of the other ladder part becomes too small. In this case, the ladder can only be extended further if the upper ladder is tilted against the middle ladder, i.e. if the lower end of the upper ladder is pivoted away from the lower end of the middle ladder.

In order to avoid pinching the fingers during further movement, the link has a further area, for example the slope or a curved structure. Only when the area in which a step/rung and a rung/step of the adjacent ladder part can come too close is left does the shape of the backdrop allow the top ladder bars to be placed on the rungs of the middle ladder again.

Such a backdrop can be designed, for example, as a simple diamond-shaped metal plate, which is attached to a ladder rail in such a way that one tip points horizontally away from the ladder rail and two tips point along the ladder rail. The backdrop is preferably, for example, semicircular or designed as a beveled metal plate. A backdrop can also have a more complex geometric shape. The steps of the upper ladder can be 80 mm deep as standard. For example, if a spar is 73mm deep, the step can project forward or backward, or both forward and backward.

For example, the steps of the upper ladder can be offset to the front, i.e. on the side of the upper ladder that does not rest on the middle ladder. Such an offset design of the steps of the upper ladder can also ensure that the prescribed minimum clearance of at least 18 mm between the steps is maintained despite the adjacent steps and rungs at the transition between the middle ladder and the upper ladder. This ensures that the user's fingers are not trapped.

A fixing device is preferably provided on the upper ladder and/or the middle ladder, in particular essentially at the height of the lowest rung. With this fixing device, the sliding position of the conductor parts, i.e. the upper and middle conductors as well as the middle and lower conductors, can be fixed to one another.

This fixing device is preferably mounted a height distance between two steps, i.e. a step height, away from the retaining brackets of the middle conductor or lower conductor. However, it can also be attached anywhere else, but preferably in the upper third of the middle ladder and / or upper ladder.

According to the invention, the fixing device is designed in such a way that when the ladder is in the extended state, the upper, middle and lower ladders are fixed in their positions, against which the steps and rungs or rungs and rungs of each adjacent ladder part rest in the transition area between the ladder parts State of the ladder is at the same step height and preferably forms a flat step surface that is essentially horizontal.

For this purpose, the fixing device can, for example, have a hanging hook, which fixes the position of the ladder by being hooked onto a rung from above. If the hook is hooked in, the ladder can no longer be retracted. This is only possible again when the extended ladder part is pulled out a little further, more precisely by the length of the hanging hook, and then the lower end of the upper ladder part is pivoted against the lower ladder part. This movement releases the hook so that the extended ladder parts can be retracted.

The fixing device can also have a locking tongue which is mounted in a sliding manner and allows the fixing device to snap into place on the respective rungs. This locking tongue can be designed so that it locks automatically or so that it has to be locked by hand. Unlocking is possible, for example, via a finger hole. The locking tongue is slidably mounted against the fixing device. The finger hole is used to securely grip the locking tongue and therefore make it easier to move.

In a preferred embodiment, the hanging hook of this fixing device is formed in an element in which the link is also formed, so that even when the ladders are unhooked or pushed, the fingers are trapped between the ladder parts, i.e. between a step or rung of the upper ladder part (upper or middle ladder) and one rung of the lower part of the ladder (middle or lower ladder) is impossible. By combining the fixing device with the link, one component of the ladder can be saved, which on the one hand keeps costs down, but on the other hand also keeps the weight of the ladder down.

The fixing device with hanging hooks preferably has a vertical and a horizontal area. The vertical area above the actual hanging hook prevents the next lower step from getting too close to the relevant rung of the lower or middle ladder in the contact position. Due to the horizontal area, i.e. the horizontal extension of the hanging hook at its curvature, the distance in the horizontal direction is set to a minimum so that the prescribed 18 mm is not exceeded here either.

This results in maximum immersion of the respective two conductor parts without falling below the minimum distances. The maximum immersion of the ladders into one another, i.e. the pivoting in the horizontal direction, prevents an excessive setback, i.e. an excessively large distance between the upper and middle conductors or middle and lower conductors. Too much distance can lead to accidents when climbing down the ladder.

Furthermore, the maximum immersion allows the rungs of two ladder parts to be spaced apart horizontally by a maximum of 45 mm when they are next to each other or for the free space between two rungs of adjacent ladder parts not to exceed 45 mm. Two rungs therefore look like one step.

In an advantageous embodiment, the rungs of the lower ladder are not arranged exactly in the middle of the spar, but are offset to the rear, i.e. away from the central ladder. This creates more space for immersion.

In a further embodiment, there is a certain height offset of the steps in the respective transition areas of the ladder parts, corresponding to the inclination of the ladder when leaned. The standard lean angle is 65 to 70° to the horizontal. The height offset is designed so that the top rung of the lower ladder (middle or lower ladder) is horizontally aligned with the surface of the step of the upper ladder (middle or upper ladder). In this embodiment, the tops of the treads on the upper ladder are at the same height as the tops of the treads on the middle ladder. The tops of the treads on the middle ladder are also preferably aligned with the tops of the treads on the lower ladder.

The ladder according to the invention can be leaned against a building in its extended form. Then the spar axis of the lower ladder, i.e. the longitudinal axis, which runs along a ladder spar, here the lower ladder spar, is closer to the building than the spar axis of the middle ladder and this in turn is closer to the building than the spar axis of the upper ladder. This means that the steps at the upper transition area are further away from the building than the corresponding steps of the adjacent ladder section, which are at the same step height in this transition area. In other words, the steps on the upper ladder are on the climber's side when the ladder is leaning against a building or a wall when extended.

Further advantages, details and features emerge from the following description of several exemplary embodiments of the invention based on the drawings.

• 1 eine erfindungsgemäße Leiter in ausgezogenem und verschwenktem Zustand in zwei Ansichten, nämlich:
• 1a eine erfindungsgemäße Leiter in ausgezogenem und verschwenktem Zustand in Perspektivansicht;
• 1b eine erfindungsgemäße Leiter in ausgezogenem und verschwenktem Zustand in Seitenansicht;
• 2 eine erfindungsgemäße Leiter in vollständig ausgezogenem Zustand in zwei Ansichten, nämlich:
• 2a eine erfindungsgemäße Leiter in vollständig ausgezogenem Zustand in Frontalansicht;
• 2b eine erfindungsgemäße Leiter in vollständig ausgezogenem Zustand in Seitenansicht;
• 3 ein Detail der erfindungsgemäßen Leiter in ausgezogenem und verschwenktem Zustand in Perspektivansicht gemäß 1a, unter Darstellung des Übergangsbereichs zwischen den einzelnen Leiterteilen, nämlich:
• 4 eine erfindungsgemäße Leiter in nicht ausgezogenem und verschwenktem Zustand in Seitenansicht;
• 5 eine erfindungsgemäße Leiter in kompaktem Zustand in zwei Ansichten, nämlich:
• 5a eine erfindungsgemäße Leiter in kompaktem Zustand in Seitenansicht;
• 5b eine erfindungsgemäße Leiter in kompaktem Zustand in Frontalansicht;
• 6 eine Seitenansicht eines Teils des Übergangsbereichs zweier Leiterteile;
• 6a Seitenansicht eines Teils des Übergangsbereichs zweier Leiterteile mit Fixiervorrichtung aus 3 in Detailansicht in einer ersten Position;
• 6b Seitenansicht eines Teils des Übergangsbereichs zweier Leiterteile mit Fixiervorrichtung aus 3 in Detailansicht in einer zweiten Position; und
• 6c Seitenansicht eines Teils des Übergangsbereichs zweier Leiterteile mit Fixiervorrichtung aus 3 in Detailansicht in einer dritten Positionen.
• 7 eine Detailansicht einer Fixiervorrichtung im Übergangsbereichs zweier Leiterteile in Seitenansicht, nämlich:
• 7a Seitenansicht einer weiteren Fixiervorrichtung im Übergangsbereich zweier Leiterteile in der Positionen nach 6c;
• 7b Seitenansicht einer dritten Fixiervorrichtung im Übergangsbereich zweier Leiterteile in der Positionen nach 6c; und
• 7c Seitenansicht einer vierten Fixiervorrichtung im Übergangsbereich zweier Leiterteile in der Positionen nach 6c.

Show it:

• 1 a ladder according to the invention in the extended and pivoted state in two views, namely:
• 1a a ladder according to the invention in an extended and pivoted state in a perspective view;
• 1b a ladder according to the invention in an extended and pivoted state in a side view;
• 2 a ladder according to the invention in the fully extended state in two views, namely:
• 2a a ladder according to the invention in a fully extended state in a frontal view;
• 2 B a ladder according to the invention in a fully extended state in a side view;
• 3 a detail of the ladder according to the invention in the extended and pivoted state in a perspective view 1a , showing the transition area between the individual conductor parts, namely:
• 4 a ladder according to the invention in a side view in a non-extended and pivoted state;
• 5 a ladder according to the invention in a compact state in two views, namely:
• 5a a ladder according to the invention in a compact state in side view;
• 5b a ladder according to the invention in a compact state in a front view;
• 6 a side view of a part of the transition area between two conductor parts;
• 6a Side view of part of the transition area between two ladder parts with a fixing device 3 in a detailed view in a first position;
• 6b Side view of part of the transition area between two ladder parts with a fixing device 3 in a detailed view in a second position; and
• 6c Side view of part of the transition area between two ladder parts with a fixing device 3 in detail view in a third position.
• 7 a detailed view of a fixing device in the transition area between two conductor parts in a side view, namely:
• 7a Side view of another fixing device in the transition area between two ladder parts in the positions shown 6c ;
• 7b Side view of a third fixing device in the transition area between two ladder parts in the positions shown 6c ; and
• 7c Side view of a fourth fixing device in the transition area between two ladder parts in the positions shown 6c .

1 and 2 show a schematic representation of a ladder according to the invention in a perspective view ( 1a) , in frontal view ( 2a) as well as in side view ( 1b , 2 B) . The ladder 1 shown has an upper conductor 2, a middle conductor 4 and a lower conductor 6. The upper conductor 2 and the middle conductor 4 are guided together so that they can slide. The middle conductor 4 and the lower conductor 6 are guided together so that they can slide and pivot.

1 shows the ladder according to the invention in its unfolded form with the upper ladder 2 extended. 2 shows the ladder according to the invention in its fully extended position. The lower ladder 6 stands in a manner known per se on a traverse 8, which is attached to its lower end in the manner of a crossbar.

The upper ladder spars 10 and 12 lie inside and offset against the middle ladder spars 14 and 16 and these in turn lie inside and offset against the lower ladder spars 18 and 20. The sliding mobility of the upper ladder 2 and middle ladder 4 is on the middle ladder 4, specifically in the area of its upper quarter , a center conductor retaining bracket 22 and 24 is attached to each center conductor spar 14 and 16.

The middle ladder retaining brackets 22 and 24 each grip one of the upper ladder bars 10 and 12 and guide it in a sliding manner. The top ladder bars 10 and 12 are laterally offset, guided within the middle ladder bars 14 and 16, with a distance of 8 to 10 mm between the bars 10 and 14 on the one hand and 12 and 16 on the other.

For the combined sliding and pivoting mobility of the middle conductor 4 and lower conductor 6, a specially designed lower conductor retaining bracket 26 and 28 is attached to each lower conductor spar 18 and 20 on the lower conductor 6, in the area of its upper quarter.

The lower ladder retaining brackets 26 and 28 each encompass one of the middle ladder bars 14 and 16 and guide it in a sliding manner, but in addition to the sliding movement they also allow pivoting mobility, so that the ladder can be used as a leaning ladder (as in this one). 2 shown) and on the other hand as a stepladder or trestle ladder (as in this one 1 shown) can be used.

A simple one-piece leaning ladder, also known as a leaning ladder, consists of two bars and rungs in between. In addition to the one-piece leaning ladder, there are also 2 or 3-part leaning ladders. This is also called an extension ladder because you can move the ladder parts against each other to reach greater heights. A stepladder or trestle ladder, on the other hand, is a ladder that consists of two parts connected to each other via joints. To prevent the ladder from unintentionally spreading, both parts are connected with a tension belt, chain or bracket.

The middle conductor bars 14 and 16 are laterally offset, guided within the lower ladder bars 18 and 20, with a distance of 8 to 10 mm between the bars 14 and 18 on the one hand and 16 and 20 on the other.

In order to prevent the ladder 1 from unintentionally spreading, the middle conductor bars 14 and 16 and the lower ladder bars 18 and 20 are each connected to an over-spreading safety device 30 and 32. In a further embodiment, not shown, a one-sided over-spreading protection 30 or 32 is sufficient.

Furthermore, there is a little more than a height distance between two appearances of the respective retaining brackets, i.e. the center conductor retaining brackets 22 and 24 or the lower conductor retaining brackets 26 and 28, a fixing device 34 or 36 is attached to the upper conductor 2s or the middle conductor 4, with which the sliding position of the respective ladder parts, i.e. on the one hand the upper conductor 2 and the middle conductor 4 and on the other hand the middle conductor 4 and the sub-conductor 6 can be fixed to one another.

The middle conductor 4 and the lower conductor 6 have a plurality of rungs 18 which, in a manner known per se, extend at a regular distance from one another along the respective conductor parts, i.e. middle conductor 4 and lower conductor 6. The upper ladder 2 has a plurality of steps 40. Furthermore, it has 3 rungs 42 in its upper area and a rung 44 at its lower end, below the steps 40.

Overall, the upper ladder 2 has 4 rungs 42, 44 and 4 steps 40. At its upper end, the upper ladder 2 in this embodiment has contact rollers 46 and 48, which extend in a manner known per se, so that they can run along the wall, not shown, on which the ladder is placed.

The feed rollers 46 and 48 therefore protrude from the upper ladder rails 10 and 12 on site. They are preferably mounted on a common axle 50, which in turn is mounted in the upper ladder bars 10 and 12. The upper ladder spars 10 and 12 have a width A, which is the same in a known manner over the entire spar length.

In a manner also known per se, all of the spars (upper ladder spars 10 and 12, middle ladder spars 14 and 16, lower ladder spars 18 and 20) are designed as extruded profiles and are pierced by the steps 40 and rungs 38, 42 and 44. The term appearance is used here as a generic term for levels 40 and rungs 38, 42 and 44.

The width B of the middle ladder spars 14 and 16 and the width C of the lower ladder spars 18 and 20 is equal to the width A of the upper ladder spars 10 and 12, but the distance between the spars is not the same. However, these widths can also differ. The widths are in 3 shown. As already mentioned, the upper ladder spars 10 and 12 are laterally offset and within the middle conductor spars 14 and 16 and these in turn are laterally offset and within the lower ladder spars 18 and 20. Thus, the upper ladder 2 is narrower than the middle conductor 4 and these in turn are narrower than the lower ladder 6 .

3 shows a detail of the conductor according to the invention 1a , showing the transition area between the individual conductor parts. The middle conductor retaining brackets 22 and 24 and the lower conductor retaining brackets 26 and 28 each encompass the upper conductor spars 10 and 12 and the middle conductor spars 14 and 16.

The - on-site - underside of the upper ladder 2 (or the middle ladder 4 when the ladder is completely extended and not folded out) slides laterally offset and within the middle ladder 4 (or lower ladder 6), but above its rungs 38, i.e. on the - user-side - top side the middle conductor 4 (or lower conductor 6). The specially designed lower ladder retaining brackets 26 and 28 allow not only sliding mobility ( 2 ), the lateral pivoting mobility shown here.

The spar depth of the spars (upper conductor spars 10 and 12, middle conductor spars 14 and 16, lower conductor spars 18 and 20) is 73 mm in this embodiment and the lateral offset, i.e. the distance of the spars 10 and 14 or 12 and 17 between upper conductor 2 and middle conductor 4 or the bars 14 and 18 or 16 and 20 between the middle conductor 4 and the lower conductor 6 is 10 mm in this embodiment.

In this embodiment, the steps 40 have a depth of 80 mm and are therefore wider than the spars (upper ladder spars 10 and 12, middle ladder spars 14 and 16, lower ladder spars 18 and 20). In this respect, the steps 40 protrude slightly backwards, i.e. towards the on-site underside of ladder 1, but only by a little less than 10% of their depth.

Furthermore, in 3 the upper fixing device 34 is shown. This is screwed to the upper ladder spar 10 with two screw bolts 52 and 54. It has a hanging hook 56 which points downwards and is designed to hook into the second highest rung 58 of the central ladder 4. The fixing device 34 or 36 is in detail in 6 shown.

4 and 5 shows a schematic representation of a ladder according to the invention in a side view ( 4 , 5a) as well as in frontal view ( 5b) . 4 shows the ladder according to the invention in its unfolded form with the upper ladder 2 not extended. 5 shows the ladder according to the invention in its compact form.

6 shows the fixing device 3 in detail view in 3 different positions. The upper fixing device 34 is shown here as an example. This is attached to the upper ladder 2 at the level of the lowest rung 44.

The fixing device 34 is designed so that in the extended state it fixes the upper ladder 2 to the middle ladder 4 so that the lowest of the steps 60 of the upper ladder 2 and the top rung 38 the middle ladder 4 or the lowest rung 44 of the upper ladder 2 and the second highest rung 58 of the middle ladder are at the same step height when the ladder 1 is leaning.

The fixing device 34 is designed in such a way that even when unhooking the hanging hook 56 or the sliding movement of the ladder parts, fingers get caught between the steps of one ladder part (upper ladder 2 or middle ladder 4) and the rungs 38 of the other ladder part (middle ladder 4 or lower ladder 6 ) is impossible. For this purpose, the hanging hook 56 in this embodiment has a vertical area 62 and a horizontal area 64.

6a and 6b show how the horizontal area 64 sets the distance in the horizontal direction to a minimum so that the prescribed 18 mm is not exceeded.

6c shows how the vertical area 62 prevents the next lower step from coming too close to the relevant step of the lower or middle ladder in the contact position.

This design of the fixing elements 34 and 36 results in maximum immersion, i.e. the pivoting in the horizontal direction, of the respective two conductor parts (upper conductor 2 with middle conductor 4 or middle conductor 4 with lower conductor 6) without falling below the minimum distances.

The minimum distances ensure that between the steps 40/rungs 38 of the upper ladder part (upper ladder 2 or middle ladder 4) and the rungs 38 of the lower ladder part (middle ladder 4 or lower ladder 6), for example the lowest of the steps 60 of the upper ladder 2 and the top rung 38 of the central ladder 4, even when applied there is a free space 66 (see 1 and 3 ) in the area of transition 68 is ensured and that this clearance is at least 18 mm. In the examples, this distance is 25 mm ( 6a) , 21 mm ( 6b) and 34 mm ( 6c ).

This free space 66 is sufficient to prevent the user from getting their fingers trapped when the two ladder parts are pushed. However, this free space 66 is smaller than the width of a foot, i.e. smaller than 70 mm.

• drittoberste Sprosse 70 der Mittelleiter 4;
• zweitoberste Sprosse 58 der Mittelleiter 4 + unterste Sprosse 44 der Oberleiter 2;
• oberste Sprosse 72 der Mittelleiter 4 + unterste Stufe 60 der Oberleiter 2;
• zweitunterste Stufe 74 der Oberleiter 2.

Starting from the middle ladder 4, the step sequence results:

• third highest rung 70 of the middle ladder 4;
• second highest rung 58 of the middle ladder 4 + lowest rung 44 of the upper ladder 2;
• top rung 72 of the middle ladder 4 + bottom step 60 of the top ladder 2;
• second lowest step 74 of the senior ladder 2.

In this respect, the change in performance style is gentle and fluid.

The maximum immersion of the ladder parts also prevents excessive recess, i.e. too large a distance between the ladder parts. The horizontally adjacent rungs of two ladder parts, for example the lowest rung 44 of the upper ladder 2 and the second highest rung 58 of the middle ladder 4, are therefore at most 45 mm apart from each other and thus give the feeling of an additional step. This ensures the user feels safe when climbing ladder transitions. The user feels a firm footing when entering, which significantly increases surefootedness. Furthermore, the maximum immersion ensures that the ladder 1 remains in its compact form as shown in 5 is shown, narrow and therefore easier to store, transport and handle.

In 6 a until c A spring-loaded locking tongue 76 is also shown, which is attached to the upper ladder 2 in a sliding manner. In the case of the lower fixing device 67, not shown here, the corresponding locking tongue would thus be attached to the center conductor 4.

In the condition shown 6a the locking tongue 76 engages around the second-topmost rung 58 of the middle ladder 4 from below, so that the middle ladder 4 is locked against the upper ladder 2 and completely fixed. The locking tongue 76 can be moved manually towards the worker, i.e. towards the upper ladder spar (10, 12), via a finger hole 78, which releases the second highest rung 58 of the middle ladder 4 and thus the middle ladder 4.

In order to move two conductor parts against each other, i.e. either the upper conductor 2 against the middle conductor 4 or the middle conductor 4 against the lower conductor 6, the fixing device (34, 36) is first unlocked by actuation through the finger hole 78 and then the respective upper conductor part, i.e. upper conductor 2 or the middle conductor 4, slightly raised in order to release the hanging hook 56. The upper, now unlocked conductor part is then pivoted against the lower conductor part, i.e. middle conductor 4 or lower conductor 6, so that its sliding mobility does not allow the respective fixing device 34 or 36 to intervene. This allows the respective ladder parts to be pushed together or pulled apart.

7 shows three alternative embodiments of a fixing device 3 in detail check the position 6c . These exemplary embodiments show possible configurations of a link 80, which in these exemplary embodiments is designed as part of a fixing device 34, 36, in a detailed view. However, the link 80 can also be designed as a separate component, i.e. not as part of the fixing device 34, 36.

The backdrop 80 each has a vertical area 62 and a horizontal area 64 and, in this illustration, forms a spacer together with the hanging hook 56. This ensures that between the adjacent appearances of the conductor parts that are guided along one another, here the middle conductor 4 and the upper conductor 2.

7a shows an exemplary embodiment of the backdrop 80 in a similar position 6c . In this exemplary embodiment, however, it is provided that the vertical region 62 of the link 80 forms an upper, horizontally extending guide surface. Compared to the design according to 6 , in which only a vertical pin/thorn serves as a vertical area 62, here the right corner of the vertical area 62 extends more towards the adjacent ladder part. Through this wider vertical area 62, it can be achieved in a simple manner, on the one hand, that the next lower step in the contact position is prevented from being too close to the relevant step of the lower or middle conductor 6, 4 or upper conductor/middle conductor 2,4 comes, and in addition, that when the movement starts from the contact position, one ladder part must first be raised by a certain amount, which is higher than with a pin or mandrel, before the ladder parts can be moved relative to one another. This easily prevents fingers from becoming trapped during all phases of the movement.

7b shows an exemplary embodiment of the link 80, in which the vertical area 62 of the link 80 has a curve or a convex area which interacts with the steps/rungs of the adjacent ladder part. Such a design also makes it possible in a reliable manner to prevent the appearances of two adjacent conductor parts from coming too close to one another, either horizontally or vertically. This applies in this exemplary embodiment, analogously to the exemplary embodiment 7a , even when starting to pull out the ladder. In addition, the rounded design of the vertical area 62 enables the ladder to be pulled out with little vibration and therefore runs smoothly, since the adjacent ladder part is guided gently along the curve.

7c shows that the backdrop 80 is not attached at the level of a performance, but above (or possibly below) one. This enables a very narrow design of the link 80. For this purpose, as shown, the vertical region 62 of the link 80 can be spaced from the horizontal part 64 by only an oblique edge. This allows smooth removal and material savings, without, however, impairing the function of the link 80 as a spacer.

All features explained and shown in connection with individual embodiments of the invention can be provided in different combinations in the object according to the invention in order to simultaneously realize their advantageous effects.

The scope of protection of the present invention is given by the claims and is not limited by the features explained in the description or shown in the figures.

REFERENCE SYMBOL LIST

1

Director

2

Senior leader

4

Middle conductor

6

Sub-leader

8th

traverse

10

Upper ladder spar on the left

12

Upper ladder spar on the right

14

Center ladder spar on the left

16

Center ladder rail on the right

18

Lower ladder spar on the left

20

Lower ladder spar on the right

22

Center conductor retaining bracket on the left

24

Center conductor retaining bracket on the right

26

Lower ladder retaining bracket on the left

28

Lower ladder retaining bracket on the right

30

Overspread protection on the left

32

Overspread protection on the right

34

Upper fixation device

36

Lower fixing device

38

sprouts

40

stages

42

Top 3 rungs of the senior ladder

44

Lower rung of the upper ladder

46

Feeder roller on the left

48

Feeder roller on the right

50

Common axis

52

Screw bolt 1

54

Screw bolt 2

56

Hanging hooks

58

Second highest rung of the middle ladder

60

Bottom step of the senior ladder

62

Vertical backdrop area

64

Horizontal backdrop area

66

free space

67

Lower transition area

68

Upper transition area

70

Third highest rung of the middle ladder

72

Top rung of the middle ladder

74

Second lowest step of the senior ladder

76

locking tongue

78

finger hole

80

Backdrop

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2876047 A1 [0002, 0003]
• EP 1607570 A2 [0006]

Claims (15)

Ladder, with an upper ladder (2), a middle ladder (4) and a lower ladder (6), each of which has ladder bars (14, 16, 18 and 20) and several steps that are designed as steps or rungs, the ladder bars ( 14, 16, 18 and 20) each have a retaining bracket (22, 24, 26 and 28), each middle conductor retaining bracket (22, 24) having an upper conductor spar (10, 12) and each lower conductor retaining bracket (26, 28) having a central conductor spar (14, 16) and wherein the upper ladder (2) is mounted displaceably against the middle ladder (4) and the middle ladder (4) is mounted on the lower ladder (6) in both a displaceable and pivotable manner, characterized in that the upper ladder (2) has a work area which comprises at least 2 steps (40), and that when the ladder (1) is extended, a step (38) of the middle ladder (4) is at the same step height as a step (40) of the upper ladder (2), and whereby in this state there is a free space (66) between these steps (40) of the upper conductor (2) and the adjacent steps (38) of the middle conductor (4) at the same step height, which is 18 mm or more. Ladder after Claim 1 , characterized in that the upper ladder (2) is narrower than the middle ladder (4) and this in turn is narrower than the lower ladder (6) and / or the middle ladder (4) and / or the lower ladder (6) only have rungs (38). . Ladder after Claim 2 , characterized in that in the compact or extended state, when viewed from the side, the bars (10, 12, 14, 16, 18 and 20) are offset from one another and arranged to overlap each other and that the upper ladder bars (10, 12) are on the rungs (38) the middle ladder (4) and the middle ladder bars (14, 16) rest on the rungs (38) of the lower ladder (6). Ladder according to one of the preceding claims, characterized in that the working area comprises at least 3 steps (40), preferably exclusively steps (40), and / or that in the extended state the ladder (1) has the second highest rung (58) or the third highest rung the middle ladder (4) is at the same step height as the lowest rung (44) of the upper ladder (2). Ladder according to one of the preceding claims, characterized in that the upper ladder (2) has three rungs (42) as steps at its upper end, to which a plurality, in particular at least two, preferably at least four, particularly preferably exclusively, steps (40 ) connect downwards. Ladder according to one of the preceding claims, characterized in that when the ladder (1) is fully extended, it has a lower transition region (67) between the lower conductor (6) and the middle conductor (4) and an upper transition region (68) between the middle conductor (4) and the upper conductor (2) exists, and that the upper transition area (68) has the following sequence of appearances from bottom to top: 1st rung 2nd rung + rung 3rd rung + step 4th step. Ladder according to one of the preceding claims, characterized in that a link (80) is provided which determines the free space, i.e. the distance, between an appearance of the upper conductor (2) and an appearance of the middle conductor (4) and/or the distance between one Appearance of the middle conductor (4) and an appearance of the lower conductor (6) is set to a minimum, in particular of 18 mm or more. Ladder after Claim 7 , characterized in that the link (80) is attached on one side, i.e. adjacent to a spar, preferably on the upper ladder (2) or on the middle ladder (4), in particular on a spar of the respective ladder part. Ladder after Claim 8 , characterized in that when moving a ladder part (centre conductor (4) or the lower conductor (6)) adjacent to the ladder part to which it is attached, the link (80) comes into contact with its treads and pushes the adjacent ladder part away. Ladder after Claim 7 , 8th or 9 , characterized in that when the ladder (1) is pulled out, an upper vertical area (62) of the link (80) represents the vertical distance between two steps of adjacent ladder parts and a lower horizontal area (64) of the link the horizontal distance between two steps of adjacent ladder parts set to a minimum of 18 mm. Head after one of the Claims 7 until 10 , characterized in that the link (80) is designed in two parts and is attached to a ladder part on both sides, in particular on the upper ladder (2) and the middle conductor (4) or on the middle ladder (4) and the lower conductor (6), in particular on the Holes of the respective ladder parts and / or that the first link part is designed to guide the second link part and, in particular when pulling out the ladder (1), sets both a vertical and a horizontal distance between two steps of adjacent ladder parts to a minimum. Head after one of the Claims 7 until 11 , characterized in that the link (80) is designed as part of a fixing device (34, 36). Ladder according to one of the preceding claims, characterized in that in the transition areas (67, 68), i.e. the areas in which ladder parts (2, 4, 6) overlap in the extended state, the appearance of the upper conductor (2) and middle conductor ( 4) or of the middle conductor (4) and lower conductor (6) with a leaning angle of the ladder between 65 and 70° - based on the horizontal - the tops of the steps on the upper ladder (2) on the one hand and the middle conductor (4) on the other hand or on the middle conductor (4) on the one hand and the lower conductor (6) on the other hand are at the same height. System consisting of a building and a ladder according to one of the Claims 1 until 13 , characterized in that when the extended ladder is leaned against the building, the lower ladder (6) springs back at a lower transition area to the middle ladder (4), i.e. is shifted towards the building and / or the middle ladder (4) at an upper transition area (68) jumps back to the upper ladder (2), i.e. it is shifted towards the building. System consisting of a building and a ladder Claim 14 , characterized in that at the upper transition area (68), between the middle ladder (4) and the upper ladder (2), the steps (40) of the upper ladder (2) are further away from the building than the steps of the adjacent ladder part, which are each at the same step height .

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