EP1679423A1 - Step ladder with foldable platform - Google Patents

Abstract

Stepladder has leader part (1), which is close to upper end of hinge (9), at which support piece (3) is tiltable. Gap is formed between support piece and leader part (1). Safety platform (4) is tiltably attached at leader part. A tie bar (5) rests with support piece (3). Platform jack (11) is provided having end (14) covering swiveling tie bar. The tie bar connects at support piece and embracing part (13). Other end (15) of jack (11) is tiltable in assigned storage position at free tiltable part of safety platform. Embracing part of platform jack is designed as thread (19).

Description

The invention relates to a standing ladder with safety bridge according to the preamble of claim 1. Such a standing ladder consists of a ladder part which has in the vicinity of its upper end a pivot joint on which a support member attaches pivotally. The ladder is therefore freestanding set up, because when pivoting the pivotable support member from the ladder part a freestanding standing ladder is realized.

It is known to attach a safety bridge in the space between the upper end of the support member and the conductor part and to form this pivotable. When swinging the support member, the safety bridge is placed in a horizontal position and then lies with its free front, and pivotally formed end on an associated cross member of the support member.

When folding the standing ladder, the support member is pivoted to the ladder part and for this application, the safety bridge should automatically bring in the pivoted position to pivot without further manual operation, the support member against the ladder part can.

For automatic pivoting of the safety bridge so-called bridge lifter are known. For reasons of simplification, only a single bridge jack will be described in the following description, although such parts are usually arranged twice and are each attached to the left and right of the safety bridge.

Such a bridge lifter is usually made of a bent wire part, a sheet metal part, a plastic part or the like and includes with its one, front end rotatably the cross member on the support member, while the other, opposite end pivotally mounted in an associated bore on the free pivotable part of the safety bridge is included.

It is known to form the bridge lifter as Drahtbiegeteil, which so far this Drahtbiegeteil was formed with its the crossbar embracing end as a closed winding, which thus enclosed the cross member by a circumferential angle of for example 270 to 360 °.

Important here was only that this cross-strut enclosing circumferential end of the bridge lifter ensured easy rotation of the bridge lifter on the crossbar.

Disadvantage of this known bent wire part, however, was that because of the enclosure of the crossbar with a self-contained eye, the wire bending part tended to jam on the crossbar. After there was no lateral support surfaces, the eye of the bridge lifter enclosing the cross member wandered left and right on the crossbar and the displacement path was just so that it came to a self-clamping. Thus, the pivoting of the support member was strongly affected in the direction of the ladder part, because due to the self-locking effect of the bridge lifter could then only by force, the safety bridge are swung up.

The same was true for the pivoting, when the support member should be swung away from the ladder part, the safety bridge had to be brought by force - against the self-locking of the bridge lifter - in the horizontal pivot position.

In order to avoid the lateral migration of the bridge jack on the crossbar, it was known in another embodiment, in the region of the transverse strut to provide a bore through which the eye of the bridge lifter reached through, so as to form a non-displaceable pivot bearing there. Disadvantage of this embodiment, however, was that an additional processing of the cross member is required and that a replacement of the bridge jack is possible only with great effort.

A third known embodiment provides a bridge jack, in which the cross-strut encompassing part is formed as a sleeve part. The bridge lifter is a total of a very elaborate extruded profile worked, and the cross strut encompassing sleeve part had to be formed so long that a self-clamping on the crossbar during the pivoting of the bridge jack on the crossbar is avoided.

Disadvantage of this embodiment, the high cost of the designed as an extruded profile bridge lifter and the risk of jamming remains, especially if set in the interior of the sleeve part dirt or other deposits and reduce this space.

Therefore, precautionary measures must always be taken to keep the interior of the sleeve part, which rotatably surrounds the transverse strut, free from soiling.

Another disadvantage is that such a bridge lifter can be mounted only during assembly of the entire standing ladder and then is no longer interchangeable.

The invention is therefore the object of developing a standing ladder with safety bridge and associated bridge lifter so that a very cost-effective bridge lifter is realized with reliable handling, which is also easily replaceable.

In order to achieve the object, the invention is characterized in that the bridge lifter is in particular made of a metal bent part, which at its end embracing the cross member of the support part forming a Umgreifungsteil, which is formed as a thread.

In the given technical teaching, there is the significant advantage that can now be dispensed with a costly and not reliable working extruded with an attaching sleeve part. According to the invention, the bridge lifter consists in particular of a metal bent part whose end is formed as a thread, thus resulting in an easy interchangeability.

It is therefore no longer necessary to connect the bridge lifter with the crossbar during assembly of the stepladder, because this connection can be made at any time during use. After the thread of the bridge lift the cross bar at least partially surrounds, can be removed by simply removing the upper end of the bridge lifter a pivotal part of the safety bridge this part and by further twisting or unscrewing the thread from the enclosure with the crossbar the bridge lifter so easily removed become.

This is a completely new technical teaching that was not yet available in the prior art. Once this leads to a good interchangeability of the bridge jack and on the other hand is achieved with very cost-effective materials improved functionality of the bridge lifter.

In a preferred embodiment, the bridge lifter is formed from a wire profile, wherein the wire profile preferably consists of a round profile.

In another embodiment, however, an oval profile, a polygonal profile or any other profiles can be used.

It is also possible to use a plastic profile or an extruded profile instead of a wire profile, but it is important that these profiles are bent by simple bending operations, wherein in the case of using an extruded profile or a plastic profile of the at least partially enclosing the crossbar thread also in the Cast or in another molding process can be produced.

By forming the lower, the transverse strut at least partially encompassing thread of the bridge jack the advantage is achieved that a self-clamping during pivoting of the safety bridge is avoided with certainty. Namely, spaced support surfaces are formed on the cross member, so that the bridge lifter centered on the cross member and secured against lateral displacement.

The introduction of force, which takes place from the safety bridge on the straight part of the bridge jack, is thus transferred to a longer transverse surface, namely once to the beginning of the thread and then completely circumferential to the end of the thread, so that thus given a large support surface on the crossbar is. This will certainly prevent self-locking of the thread of the bridge jack on the crossbar and it is a perfect pivoting of the bridge lifter possible without the risk that the cross strut encompassing thread is dirty or is inoperable by other deposits.

Therefore, it requires no holes in the cross member more to achieve a position assurance of the bridge lifter against lateral displacement on the cross member.

The subject of the present invention results not only from the subject matter of the individual claims, but also from the combination of the individual claims with each other.

All information and features disclosed in the documents, including the abstract, in particular the spatial design shown in the drawings, are claimed to be essential to the invention insofar as they are novel individually or in combination with respect to the prior art.

In the following the invention will be explained in more detail with reference to drawings showing only one embodiment. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

Figur 1:

perspektivische Seitenansicht einer Steh-Leiter

Figur 2:

ein Detail der Steh-Leiter nach Figur 1 in perspektivischer Ansicht in halb hochgeschwenkter Stellung

Figur 3:

die Innenansicht unter die Sicherheitsbrücke nach Figur 2 mit dem Brückenheber

Figur 4:

Seitenansicht des erfindungsgemäßen Brückenhebers

Figur 5:

eine um 90° gedrehte Ansicht nach Figur 4 des Brückenhebers

Show it:

FIG. 1:

Perspective side view of a standing ladder

FIG. 2:

a detail of the standing ladder of Figure 1 in a perspective view in half raised position

FIG. 3:

the inside view under the safety bridge of Figure 2 with the bridge lifter

FIG. 4:

Side view of the bridge lifter according to the invention

FIG. 5:

a rotated by 90 ° view of Figure 4 of the bridge lifter

The stepladder according to the invention consists of a ladder part (1), which has a plurality of mutually spaced-apart steps (2) which are fixed in the space between two opposite spars (8). The upper part of the two bars (8) is closed by a tray (6) in a conventional manner.

Pivotable to the ladder part (1), a support part (3) is arranged, wherein the necessary for this pivot joint (9) in the region of the upper end of the spars (8) is fixed. The support member (3) in turn consists of two mutually parallel bars (10), which are connected to each other in the upper and lower end by a transverse strut (5).

In another embodiment, however, it is also provided that the support part (3) is designed as a ladder part with associated stages.

For larger support parts (3) and more than two cross struts (5) in the space between the spars (10) can be arranged.

FIG. 1 shows the position of use of the standing ladder. In order to collapse these standing ladder, it is necessary to pivot the safety bridge (4) in the direction of arrow (7) upwards.

The safety bridge (4) thus preferably forms the upper step of the ladder part (1) and forms a tread surface with the support part (3).

For the automatic pivoting up of the safety bridge (4) two spaced apart bridge lifter (11) are arranged, as shown in Figure 2.

Of course, the present invention is not directed to the arrangement of two parallel, each identically designed bridge jacks (11). It may also be only a single bridge lifter (11) or there may be more than two bridge lifters (11).

In the embodiment shown, in each case a bridge lifter (11) on the side of the safety bridge (4) is pivotally articulated. The bridge lifter (11) in this case has according to Figures 3 to 5, an upper, bent end (15), with which it engages pivotally through a in the side surface of the safety bridge (4) arranged bore (17). The front, from the bore (17) projecting end is secured with a cap (16), so that this end (15) can not fall out of the bore (17).

For securing this end (15) in the bore (17), however, there are various other embodiments which are also to be included in the spirit of the invention:

In a second embodiment it is provided that the end (15) has a circumferential annular groove in which engages a spring cap, which may be formed, for example in the form of a cap (16), but which has radially inwardly directed resilient lobes in its interior, so that the end (15) engages with the annular groove arranged there in the formed with resilient tabs recess of the spring cap and is secured there.

Instead of such a releasable securing of the end (15) with a spring cap, there are also other releasable fuses, such. Example, the use of a nut which is screwed onto the threaded end (15), wherein preferably this nut is formed self-locking.

In another embodiment, there are also other Einhängemöglichkeiten, which should preferably avoid an arbitrary loss and slipping out of the end (15) from the bore (17). Key openings and the like can be provided here.

It can also be a riveting at the free end (15) of the bridge lifter (11) are provided.

In the illustrated embodiment, the bridge lifter (11) consists of a bent wire part of a round wire, which for example has a thickness of 3 to 6 millimeters.

It has already been pointed out in the general description part that the invention is not limited to a wire bending part of a round profile.

Starting from the upper, cranked end (15), a straight part (12) follows, as shown in FIGS. 2 to 5.

At the front free end of the straight part (12), a bend (18) is provided, which provides approximately a turn of 60 to 120 °.

Starting from this bend (18), the wraparound part (13) follows, which according to the technical teaching of the invention is designed as a thread (19).

As a result, the thread (19) at least partially surrounds the transverse strut (5) and terminates in an end (14) which also rests on the transverse strut (5) in a supporting manner.

The invention is not limited to the fact that the thread (19) has continuously extending curves. It is also possible to provide discontinuously extending curved paths, so that the encompassing of the transverse strut in the region of the receiving space (22) (see FIG. 5) occurs only piecemeal, because the thread (19) is then not completely round and corresponds to the profile of the transverse strut (5 ), but may also have bends or lapses, so that the profile of the transverse strut (5) is only partially included on the circumference.

It is important according to Figure 5, that the thread (19), for example, only to the position (21) may extend, which means that the thread (19) does not surround the cross bar by an angle of 360 to 380 °, but only to an angle between 270 and 300 °.

It is important in all embodiments that the end (14) with respect to the bend (18) defines a support length (20) and thus the thread (19) is supported over a larger area on the outer circumference of the transverse strut (5) so to form a self-locking as protection against lateral displacement in the direction of arrows (23).

This proves that due to the support of the bend (18) on one side of the thread on the crossbar and the support of the end (14) at a distance from the support length (20) a relatively large-scale support of the thread (19) on the outer circumference the transverse strut (5) is provided.

It is of course not necessary that the thread (19) is profiled around. It has already been pointed out above that the thread (19) can also deviate piecewise from the round profile at its circumference.

In another embodiment of the invention, however, it is also possible that the thread (19) is formed as a whole oval or forms a different profile shape for the receiving space (22) and that, accordingly, the cross-strut (5) to be encompassed here, in the receiving space (22) engages, is adapted to this profile.
In this way, the receiving space (22) must be adapted only to the profile of the transverse strut (5) and the bridge lifter (11) with its thread (19) only at least partially rotatably mounted on the transverse strut (5).

Here, a rotation angle in the range of 50 to 80 ° is preferred. In this rotation angle range, therefore, the thread (19) must be rotatably arranged with the said support surfaces on the transverse strut (5).

drawing Legend

1

ladder section

2

step

3

supporting part

4

security bridge

5

crossmember

6

tray

7

arrow

8th

Holm

9

pivot

10

Holm

11

bridge lift

12

Part (straight)

13

Umgreifungsteil

14

End (front)

15

End (back)

16

cap

17

drilling

18

turn

19

thread

20

support length

21

position

22

accommodation space

23

arrow

Claims (18)

Standing ladder with safety bridge, comprising a ladder part (1) which near its upper end a pivot joint (9) on which pivotally attaches a support member (3), wherein in the space between the upper end of the support member (3) and the ladder part (1) a safety bridge (4) is pivotally mounted on the ladder part (1) which rests in the use state of standing ladder with its free front, and pivotally formed end on an associated transverse strut (5) of the support member (3) and the when pivoting the support member (3) to the ladder part (1) automatically pivoted in the collapsing position in the folding direction (7) upwards, for automatic pivoting of the safety bridge (4) at least one bridge jack (11) is provided, with its one, front end (14) rotatably the transverse strut (5) on the support part (3) with a Umgreifungsteil (13), while the other, opposite end (15) pivotally in a zugeord Neten bearing (17) is received on the free pivotable part of the safety bridge (4), characterized in that the Umgreifungsteil (13) of the bridge lifter (11) is formed as a thread (19). Standing ladder according to claim 1, characterized in that the bearing (17) of the end (15) of the bridge lifter (11) in the safety bridge (4) is a bore. Standing ladder according to claim 1 or 2, characterized in that the thread (19) surrounds the transverse strut (5) of the support part (3) completely by an angle of 360 to 380 ° or only partially by an angle between 270 and 300 ° , Standing ladder according to claim 1 to 3, characterized in that the bridge lifter (11) is produced as a bent part. Standing ladder according to claim 1 to 4, characterized in that the bridge lifter (11) is made of metal wire, sheet metal and / or plastic. Standing ladder according to claim 1 to 5, characterized in that the bridge lifter (11) is produced as an extruded part or cast part. Standing ladder according to claim 1 to 6, characterized in that the bridge lifter (11) has a circular, oval, triangular, square, rectangular, or polygonal cross-section. Standing ladder according to claim 1 to 7, characterized in that the bridge lifter (11) is a Metallrunddrahtbiegeteil with a diameter of about 3-6 mm. Standing ladder according to claim 1 to 8, characterized in that two spaced-apart bridge lifter (11) are provided. Standing ladder according to claim 2 to 9, characterized in that the securing of the end (15) of the bridge lifter (11) in the bore (17) by a clamping cap (16). Standing ladder according to claim 2 to 9, characterized in that the end (15) of the bridge lifter (11) has a circumferential annular groove in which resilient tabs of a cap (16) engage for securing. Standing ladder according to claim 2 to 9, characterized in that a particular self-locking nut is screwed onto the threaded end (15) of the bridge lifter (11) for securing. Standing ladder according to claim 2 to 9, characterized in that key openings at the end (15) of the bridge lifter (11) are provided for securing. Standing ladder according to claim 2 to 9, characterized in that a riveting at the free end (15) of the bridge lifter (11) is provided for securing. Standing ladder according to claim 1 to 14, characterized in that the thread pitch, ie the axial support length (20) of the thread (19) of the bridge lifter (11) at about 1 to 1.5 times the amount of the diameter of the Cross strut (5) is located, or approximately between the amount of the inner and outer coil diameter of the thread (19). Standing ladder according to claim 1 to 15, characterized in that the cross-sectional shape of the thread (19) of the cross-sectional shape of the transverse strut (5) of the support part (3) is adapted. Standing ladder according to claim 1 to 16, characterized in that the thread (19) about the transverse strut (5) of the support part (3) is rotatable about an angle of about 30 °. Standing ladder according to claim 1 to 17, characterized in that the bridge lifter (11) is secured against lateral displacement.

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