SE517635C2

SE517635C2 - Ladder with self-adjusting extension legs

Info

Publication number: SE517635C2
Application number: SE0003154A
Authority: SE
Inventors: Jan Folke Wallenius
Original assignee: Jan Folke Wallenius
Priority date: 2000-09-07
Filing date: 2000-09-07
Publication date: 2002-06-25
Also published as: SE0003154L; EP1320658A1; SE0003154D0; AU2001284601A1; WO2002020933A1

Abstract

The invention relates to a ladder provided with an arrangement for maintaining the ladder in upright position independent of the contour of the supporting surface. This is obtained, according to the invention, by providing the ladder with two extension legs (9,10) which are slidably carried by the side legs (1, 2) of the ladder. The extension legs are suspended by a flexible connection (11) running through a hollow step member (3) at the upper part of the extension legs. The extension legs are journalled movable on the side legs (1, 2) lockable to the side legs by locking controls (16) movable downwards on the side legs. For operating the locking controls there is a further flexible connection (14) arranged between the locking controls (16) and running through a hollow step member at the bottom part of the extension legs (9, 10). Hence, the two extension legs are movable in opposite directions a decided distance, but when the extension legs are moved upwards the locking controls are pulled downwards by the flexible connection (14) causing locking of the extension legs (9, 10) to the side legs (1, 2).

Description

_ I ant-n, o, o "nu . nu n--an ...-..uøø~ v _ _. _: .,._.ﬂ|. ... N ". ..".. -~=" _ï:-:;:;L- ::".;..u°n':': få 2' I..I . o, v. v 4 a o- a I v a q ' o- o. u v .p I I förlängningsbenen 9,10 upphängda i två parallella wirar 11, sun är fastsatta i vardera hållaren 7,8 på mse sidor om stavarna 5,6 och löper genan var sin böjd kanal 12 i de övre blocken 4 samt inuti de rörformade stegpinnarna 3. _ I ant-n, o, o "nu. Nu n - an ...- .. uøø ~ v _ _. _:., ._. Fl |. ... N". .. ".. - ~ =" _ï: -:;:; L- :: ".; .. u ° n ':': få 2 'I..I. o, v. v 4 a o- a In vaq 'o- o. Uv .p II the extension legs 9,10 are suspended in two parallel wires 11, sun are fixed in each holder 7,8 on mse sides of the rods 5,6 and each runs along its curved channel 12 in the upper blocks 4 and inside the tubular rungs 3.

De undre blocken 4 är vidare försedda med liknande kanaler 13 genom vilka två ytterligare wirar 14 löper mellan hållarna 7,8 via den ihåliga, undre stegpinnen 3. Dessa wirars ändar 15 är förgrovade och utgör låsreglage och är fastsatta på ovansidan av ett låsringsystm, sm består av fyra stålringar 16, som är påträdda vardera staven 5,6 samt en fjäder 17, som anligger mot vardera hållarens 7,8 undre vägg och trycker stålringarna 16 uppåt mot wireändarna 15.The lower blocks 4 are further provided with similar channels 13 through which two further wires 14 run between the holders 7,8 via the hollow, lower step pin 3. These ends 15 of these wires are grooved and form locking controls and are attached to the top of a locking ring system, sm consists of four steel rings 16, which are each mounted on the rod 5,6 and a spring 17, which abuts against the lower wall of each holder 7,8 and presses the steel rings 16 upwards against the wire ends 15.

Wíresystemet hålls sträckt av fjädrarna 17 och därmed hålls även blocken 4 i läge utan fästskruvar, an så önskas. Vidare hålls därigenom stålringarna 16 i läge vinkelrätt mot stavarna 5,6, så att hållarna lätt kan glida på stavarna 5,6. Såsom lätt inses är förlängningsbenen med hållarna 7,8 därigenom rörliga så, att om stegen hålls upplyftad kan det ena förlängningsbenet röra sig en sträcka i ena riktningen samtidigt son det andra förlängningsbenet av wiresystemet tvingas att röra sig sanna sträcka i motsatt riktning. Om däremot båda förlängningsbenen 9,10 genom relativt hård ansättning mt ett underlag trycks uppåt1«mner wireändarna 15 och wirarna 14 att draga ena sidan av stålringarna 16 nedåt mot verkan av fjädrarna 17 så, att stålringarna snedställs och därigewmxn låser fast hållarna 7,8 och därmed förlängningsbenen 9,10 på stavarna 5,6. Detta tillstånd varar tills stegens tryck mot underlaget upphör, då fjädrarna 17 trycker tillbaka stålringarna 16 till ett läge vinkelrätt mot stavarna 5,6.The wire system is held stretched by the springs 17 and thus the blocks 4 are also kept in position without fastening screws, as desired. Furthermore, the steel rings 16 are thereby held in position perpendicular to the rods 5,6, so that the holders can easily slide on the rods 5,6. As can be easily seen, the extension legs with the holders 7,8 are thereby movable so that if the steps are kept raised, one extension leg can move a distance in one direction while the other extension leg of the wire system is forced to move a true distance in the opposite direction. If, on the other hand, both extension legs 9,10 are pressed upwards by a relatively hard abutment with a base, the wire ends 15 and the wires 14 are pulled to pull one side of the steel rings 16 downwards against the action of the springs 17 so that the steel rings are inclined and thereby lock the holders 7,8 and thus the extension legs 9,10 on the rods 5,6. This condition lasts until the pressure of the steps against the ground ceases, when the springs 17 push back the steel rings 16 to a position perpendicular to the rods 5,6.

Förlängningsbenen 9,10 kan såsom framgår av fig.3 vara något smalare än en normal standardstege och lämpligen löpa kant i kant med de flänsar, som brukar finnas på standardstegar av lättmetall.As can be seen from Fig. 3, the extension legs 9,10 can be slightly narrower than a normal standard ladder and suitably run edge to edge with the flanges which are usually present on standard ladders of light metal.

Fig.4 visar stegen placerad på en trappavsats, varvid förlängningsbenen vid stegens nedsänkning mot trappavsatsen autcnatiskt ställer in sig ¿fter underlaget, och vid nedtryckning av stegen, exempelvis genom att en fot placeras på nedersta stegpinnen, låses benen i detta läge.Fig. 4 shows the steps placed on a landing, whereby the extension legs automatically lower themselves towards the base when lowering the steps towards the landing, and when depressing the steps, for example by placing one foot on the bottom rung, the legs are locked in this position.

Uppfinningen är självfallet inte begränsad till det här visade och beskrivna utfiårímggsexexrlplet utan kan modifieras på åtskilliga sätt inom ramen för den av patentkraven definierade uppfinningen. I stället för wires kan naturligtvis två fina kedjor användas, och m så önskas kan stavar med fyrkantsektion ersätta de med cirkulär sektion. De ingående delarna kan vidare md fördel vara så utförda att en standardstege lätt kan utrustas med delarna för bildande av en stege enligt uppfinningen.The invention is of course not limited to the exemplary embodiment shown and described here, but can be modified in several ways within the scope of the invention defined by the claims. Instead of wires, of course, two fine chains can be used, and if desired, rods with a square section can replace those with a circular section. The constituent parts can furthermore advantageously be designed in such a way that a standard ladder can easily be equipped with the parts for forming a ladder according to the invention.

Claims

u nu. n n nun., - v -.f. 5); ~ * n; ". ~“ ~ V _ ... -. ~: F- -... .. ~ .... v - »-.--- .g ..__ .., .. .-. .. ... ..: '| _' u sn, I. IQ n 1 vv Q ß. u. {v, «| -, nan-nun .. v ~ Orre. n ~ - .oas.PATENT CLAIMS

Ladder with two side pieces (1,2) and a number of step pins (3) extending between them and an extension leg (9, 10) arranged at the foot end of each side piece, which is slidably arranged parallel to the side piece, and the extension legs (9 , l0) are interconnected by a flexible connection (ll, l4), which runs in a closed path along the foot ends of the side pieces and two step pins, allowing the movements of the extension legs (9, l0) in opposite directions a certain maximum distance, and as required ﬂ «Juner a locking of the extension legs against the side pieces, when a tightening occurs in the flexible connection, by the extension legs being applied to a base at the same time, characterized in that a holder (7,8) for a locking device with a resilient member (17) ) actuatable locking slider (15) is fixedly arranged on each extension leg for locking these relative respective side pieces in the event of an actuation of the locking sliders (15) directed towards the foot ends of the extension legs, and that the flexible connection is divided into an upper part (ll), the ends of which are fixed in the holder (7,8), and a lower part (14), the ends of which form the locking controls (15).

Ladder according to claim 1, characterized in that the extension legs (9, 10) are mounted on separate circular-cylindrical rods (5,6), each mounted on each side piece parallel to them, and on which one with the holder (7,8) the connected locking ring system (16) is slidably arranged, inclined in the locking direction of said locking control (15) for locking the extension legs (9, 10) on the respective rod (5,6).

Ladder according to claim 1 or 2, characterized in that at least the two lowest rungs (3) of the ladder are tubular and open on the outside of the side pieces, where in each opening a block (4) is inserted, provided with a fastening device for one end of said rods (5,6) and at least one curved channel (l2, l3) for guiding said flexible connection (ll, l4) into and out of associated step pins.

Ladder according to one of Claims 1 to 3, characterized in that each of the two parts of the flexible connection comprises two parallel wires (11, 14) with the ends located on each side of the said rods (5, 6).