SE543175C2

SE543175C2 - A support unit for a ladder and a ladder

Info

Publication number: SE543175C2
Application number: SE1951026A
Authority: SE
Inventors: Bengt Ekblom
Original assignee: Bengt Ekblom
Priority date: 2019-09-10
Filing date: 2019-09-10
Publication date: 2020-10-20
Also published as: SE1951026A1; EP3792447A1

Abstract

A support unit (1) for a ladder (19) is described. The support unit (1) comprises a connection member (3) configured for removably connecting the support unit (1) to a side rail (21) of the ladder (19). The connection member (3) comprises a surface (5) arranged for facing an opposite surface (8) of the side rail (21) and a supporting leg (7) rotatably connected to the connection member (3) and arranged to be rotated around an axis of rotation (a) relatively the connection member (3) between a rest position and an active position. In the active position the supporting leg (7) forms an angle (a) of inclination with the surface (5) of the connection member (3) and in the rest position is arranged to permit the connection member (3) to slide along the side rail (21). In the active position an edge portion (9) of the supporting leg (7) extends through the surface (5) to protrude from the surface (5) and to engage the opposite surface (8) of the side rail (21). A ladder (19) is also described.

Description

AND PRIOR ART The present invention relates generally to safety devices and more particularlyto a support unit that can make a ladder safe from sliding sideways. Thepresent invention relates also to a ladder comprising at least one support unit.

Ladders, especially extension ladders, are very effective in allowing a personto reach a high, otherwise inaccessible position for painting, repair or otherrelated tasks. However, accidents frequently occur because of lateral tipping orslipping movements. lf the ladder is not completely vertical the chances of ittipping laterally as the person rises thereon increase as the height above theground increases.

Efforts have been made to improve the stability of a ladder and people haveattempted to provide different types of ladder supports. US7163084B1 andUS4655322A are examples where supports are used to prevent sidewaystipping of ladders. ln the US7163084B1 an adjustable ladder stabilizer isattached to the side rail of a ladder by drilling holes in the rails and attaching achannel mounting bracket by, for example bolts. ln the US4655322A a clampdevice is used for anchoring of a safety leg to a ladder.

Although, the devices described in the US7163084B1 and in the US4655322Awork well, the construction of the devices is quite complicated and requiresseveral elements. Therefore, there is a desire to provide an improved supportunit for a ladder considering, inter alia, facilitating of the attaching procedure ofthe support unit at the ladder. Further, there is a desire to provide a ladder withan improved support unit.

SUMMARY OF THE INVENTION The object of the present invention is to provide an improved support unit for aladder and to provide a ladder with an improved support unit.

The object is achieved by the support unit defined in claim 1 and by the ladderdefined in claim 11.

Thus, the above mentioned object is achieved by a support unit for a ladder,comprising: a connection member configured for removably connecting thesupport unit to a side rai| of the ladder. Thus, the connection member isconfigured to enable the support unit to be connected, i.e. to be attached to theside rai| of the ladder and to be removed from the side rai|. The process ofconnecting and removing of the support unit can be repeated.

The connection member comprises a surface arranged for facing an oppositesurface of the side rai|. The surface can be defined as a surface of theconnection member positioned parallel to the opposite surface of the side rai|when the connection member has been positioned at the side rai| in a positionenabling connection of the support unit to the side rai|. Thereby, with thesurface arranged for facing an opposite surface of the side rai| is meant thatthe surface can be parallel with the opposite surface of the side rai|.

Further, the support unit comprises a supporting leg rotatably connected to theconnection member and arranged to be rotated around an axis of rotationrelatively the connection member between a rest position and an activeposition. The supporting leg may be arranged as an elongated straight orcurved element configured to support, i.e. to stabilize a ladder in the activeposition of the supporting leg when the support unit has been connected, i.e.attached to a side rai| of the ladder. ln the active position the supporting legforms an angle of inclination with the surface of the connection member and inthe rest position is arranged to permit the connection member to slide alongthe side rai|. Thus, the supporting leg can be rotated around the axis of rotationand thereby can change its position relatively the connection member. Forexample, in the rest position, the supporting leg may extend along alongitudinal axis parallel with the surface. ln the active position the supportingleg is positioned to form the angle of inclination with the surface of theconnection member, which may mean that the longitudinal axis of thesupporting leg forms the angle of inclination with the surface of the connectionmember. ln the active position an edge portion of the supporting leg extends through thesurface to protrude from the surface and to engage the opposite surface of theside rail.

The edge portion may be defined as a part of an outermost portion of thesupporting leg on an opposite side to a ground portion of the supporting leg,which ground portion is intended to have contact with the ground when thesupport unit is in use. Thus, in the active position of the supporting leg theedge portion is arranged to intersect the surface to protrude from the surfaceand to engage the opposite surface of the side rail. Thereby, the support unitcan be secured at the side rail simply by rotating the supporting leg around theaxis of rotation to the active position of the supporting leg.

Consequently, an improved support unit for a ladder is provided considering,inter alia, the way of attaching of the support unit to the side rail. The supportunit can be attached to the side rail in a simple manner and without need ofcomplicated attachment means as presented in the prior art documents.Further, at the same time as the support unit is attached to the side rail of theladder a support for the ladder is also provided by positioning the supportingleg in the active position.

Thereby the above mentioned object is achieved.

According to an embodiment the edge portion is arranged to create frictionforces between the edge portion and the opposite surface of the side rail inorder to lock the support unit at the side rail. The friction forces can be createdby a direct contact between the surface of the edge portion and the surface ofthe opposite surface of the side rail. The friction forces created between theedge portion and the opposite surface of the side rail facilitate the attachmentof the support unit and further facilitate the locking of the support unit at theside rail.

According to an embodiment, the supporting leg is positioned substantially inparallel with the surface in the rest position. Thus, the longitudinal axis of thesupporting leg is parallel with the surface.

According to an embodiment the connection member comprises a platecomprising the surface. Further, the plate comprises an opening and the edgeportion is arranged to extend through the opening and thereby through thesurface in the active position of the supporting leg. Thereby, the edge portionextends through the surface by extending through the opening of the plate.Thus, a simple connection member is provided enabling the edge portion toextend through the surface and to protrude from the surface to engage theopposite surface of the side rail. The plate is easy to manufacture.

According to an embodiment, the connection member has a rectangular crosssection and is arranged to partly enclose the side rail when the connectionmember has been connected to the side rail. Thus, the connection membercan be attached to the exterior of the side rail.

According to an embodiment the edge portion protrudes at least 2mm from thesurface in the active position of the supporting leg. Thus, the edge portionprotrudes sufficiently to enable engagement with the opposite surface of theside rail in order to lock the support unit at the side rail.

According to an embodiment the supporting leg comprises a ground supportelement. The ground support element facilitates positioning of the supportingleg at the ground making the supporting leg more stable comparing to asupporting leg not having a ground support.

According to an embodiment the ground support element comprises twoseparated support plates angled in relation to each other. The support platesmay be angled in relation to each other such that the corner of the anglebetween the support plates points upwards and towards the edge portion ofthe supporting leg. Thus, the distance between the support plates increasesalong a direction downwards from the edge portion and towards the ground.Thereby, support plates angled in relation to each other may contribute to animproved stability of the supporting leg during use of the support unit.

According to an embodiment the ground support element is attached to thesupporting leg by welding. Welding is a relative simple and reliable way ofconnecting of elements.

According to an embodiment the connection member and/or the supporting legare made of aluminium. Thereby, a support unit can be provided with relativelylow weight.

The above mentioned object is also achieved by a ladder comprising two siderails and at least one support unit according to any of the embodiments asabove. Preferably the ladder comprises two support units arranged at eachside rail of the ladder. Because the support unit exhibits improvedcharacteristics regarding, inter alia, the attachment to a side rail and thestability of the support unit, also an improved ladder is provided comprising atleast one support unit.

Thereby the above mentioned abject is achieved.

According to an embodiment each of the side rails of the ladder has arectangular cross section or a circular cross section.

BRIEF DESCRIPTION OF THE DRAWINGS ln the following preferred embodiments of the invention are described withreference to the attached drawings, on which: Fig. 1 is a side view of a support unit with a supporting leg in an activeposition, according to a first embodiment, Fig. 2 is a side view of the support unit in Fig. 1 with supporting leg in a restposition, Fig. 3 is a side view of a ladder and of the support unit in Fig. 1 with supportingleg in a rest position, Fig. 4 is a side view of the ladder and of the support unit in Fig. 3 with thesupporting leg in an active position, Fig. 5.1 is a side view of an upper part of the support unit according to the firstembodiment, Fig. 5.2 is a cross view of the support unit in Fig. 5.1, Fig. 6 is a cross view of a support unit according to a second embodiment and Fig. 7 is a cross view of a supporting leg comprising a ground support.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THEINVENTION ln Fig. 1 to Fig. 4 a support unit 1 for a |adder 19 is i||ustrated according to afirst embodiment. The support unit 1 comprises a connection member 3configured for removably connecting the support unit 1 to a side rai| 21 of a|adder 19. The |adder 19, or a part of the |adder 19 is i||ustrated in Fig. 3 andFig. 4.

The connection member 3 comprises a surface 5 arranged for facing anopposite surface 8 of the side rai| 21. The opposite surface 8 is i||ustrated, forexample in Fig. 3. Further, the connection member 3 comprises a supportingleg 7 rotatably connected to the connection member 3 and arranged to berotated around an axis of rotation a, relatively the connection member 3. Thesupporting leg 7 may comprise an opening 2' through the supporting leg 7.According to the first embodiment the connection member 3 comprises aconnection part 4 positioned perpendicularly to the surface 5. The connectionpart 4 may comprise one plate, or several plates arranged in parallel to eachother. Each of the one or several plates may comprise an opening 2”. Thus,the supporting leg 7 may be connected to the connection member 3 by meansof a joint applied through the openings 2' and 2". The joint may be a boltjoint.The bolt may comprise threads or the bolt may be a screw. ln Fig. 1, the supporting leg 7 is i||ustrated in an active position. ln the activeposition the supporting leg 7 forms an angle oi of inclination with the surface 5of the connection member 3. The angle oi is formed between the surface 5 anda side edge 7.1 of the supporting leg 7 or the angle oi may be formed between the surface 5 and a longitudinal axis 7.2 of the supporting leg 7. Thelongitudinal axis 7.2 extends along the extension of the supporting leg 7.

According to the first embodiment the supporting leg 7 is arranged as anelongated straight element extending along the Iongitudinal axis 7.2. However,the supporting leg 7 may also be arranged as a curved element comprising thelongitudinal axis 7.2. The angle oi may be between 0 to 180 degrees before thesupport unit 1 has been arranged at a ladder.

The supporting leg 7 may be hollow and may comprise four elongated walls.Thus, the cross section of the supporting leg 7 may be rectangular. Thesupporting leg 7 may be manufactured by bending and, for example, weldingof one or several plates of, for example, aluminium. Thus, the supporting leg 7may comprise two side walls, each comprising a hole for enabling theconnection of the supporting leg 7 to the connection part 4 of the connectionmember 3 which holes may form the opening 2'. Further, the supporting leg 7may comprise two intermediate walls arranged essentially perpendicularly inrelation to the side walls.

The side walls and the intermediate walls of the supporting leg 7 may have arectangular shape. ln the active position of the supporting leg 7, an edge portion 9 of thesupporting leg 7 extends through the surface 5 to protrude from the surface 5and to engage the opposite surface of the side rail (not shown in Fig. 1). Thus,the supporting leg 7 is connected to the connection member 3 such that a firstdistance d1 between the axis of rotation a and an upper end edge 6 of thesupporting leg 7 is greater than a second distance d2 between the axis ofrotation a and the surface 5, when the supporting leg 7 is connected to theconnection member 3.

The edge portion 9 is a part of an upper portion of the supporting leg 7. Theedge portion 9 comprises a corner edge 9.1. The corner edge 9.1 comprisesan upper edge of a first intermediate wall of the two intermediate walls of thesupporting leg 7. The first intermediate wall is arranged closer to the surface 5then a second intermediate wall of the two intermediate elongated walls of the supporting leg 7 when the supporting leg 7 has been connected to theconnection member 3.

The corner edge 9.1 of the edge portion 9 may engage the opposite surface 8of the side rail 21 in the active position of the supporting leg 7.

Further, the supporting leg 7 may comprise a ground support element 17. Anexample of a ground support element 17 is described in details in conjunctionto Fig. 7.

The connection member 3 and/or the supporting leg 7 may be made ofaluminium. Other possible materials for the connection member 3 and/or forthe supporting leg 7 could be, for example, steel, a carbon fiber material orother suitable material. The other parts of the support unit 1, as the joint or thesupport element 17 may be made of the same material as the connectionmember 3 and/or the supporting leg 7 or may be made of different materials. ln Fig. 2, the supporting leg 7 of the support unit 1 is illustrated in a restposition. ln the rest position the supporting leg 7 is arranged to permit theconnection member 3 to slide along the side rail 21 of the ladder 19. Thesupporting leg 7 may be positioned substantially parallel with the surface 5 inthe rest position of the supporting leg 7.

Each of the side walls comprises an upper edge 6.1 and a lower edge 6.2.According to an embodiment, the upper edge 6.1 may be angled in relation tothe intermediate wall with an edge portion angle y that is less than 90 degrees.Thus, the upper edge 6.1 may be inclined in relation to the longitudinal axis 7.2of the supporting leg 7 by the edge portion angle y. For example, the edgeportion angle y may be between 30 and 60 degrees. The sharp edge portionangle y may facilitate positioning of the supporting leg 7 in the active position.

Also the lower edge 6.2 of each of the side walls of the supporting leg 7 maybe angled in relation to the intermediate wall with an angle equal to the edgeportion angle y or with a sharp angle that is different than the edge portionangle y. Thus, also the lower edge 6.2 may be inclined in relation to thelongitudinal axis 7.2 of the supporting leg 7 by the edge portion angle y.

According to an embodiment each of the side walls of the supporting leg 7 mayhave a shape of a parallelogram.

As mentioned above, the edge portion angle v may be, for example, between30 and 60 degrees. Thus, a third distance d3 between the axis of rotation aand a corner edge 9.1' of the supporting leg 7 is greater than a seconddistance d2 between the axis of rotation a and the surface 5, when thesupporting leg 7 is connected to the connection member 3. ln Fig. 3 a ladder 19 is illustrated with a support unit 1 at one side rail 21 of theladder 19 comprising two side rails 21 _ A plurality of roads 22, forming steps,extend between and connect the two side rails 21 to each other. The side rails21 with the roads 22 connected to the side rails 21 form the ladder 19.

Preferably the ladder 19 comprises two support units 1 arranged at each siderail 21 of the ladder 19. According to the first embodiment illustrated in Fig. 3,the supporting leg 7 of the support unit 1 is positioned in a rest position. Thesupporting leg 7 positioned in the rest position may facilitate mounting of thesupport unit 1 at the ladder 19 and may facilitate transportation of the ladder19 with the support unit 1 at the ladder 19.

As illustrated in Fig. 3 the surface 5 of the connection member 3 is arrangedfor facing an opposite surface 8 of the side rail 21 of the ladder 19. The surface5 may be positioned parallel to the opposite surface 8 when the support unit 1has been positioned at the side rail 21 _ According to the first embodiment theconnection member 3 of the support unit 1 may be slide into the interior of theside rail 21 having a C-shaped cross section. Thus, the side rail 21 comprisesan elongated opening 15 (shown in Fig. 5.2) extending along the extension ofthe side rail 21.

The support unit 1 can be positioned in a desired position along the extensionof the side rail 21 simply by sliding the connection member 3 in directions z1,z2 along the extension of the side rail 21. ln Fig. 4 the ladder 19 and the support unit 1 are illustrated, where thesupporting leg 7 has been positioned in the active position. After theconnection member 3 has been slid along the side rai| 21, the ladder 19 canbe positioned on the ground 10. The position of the support unit 1 at the siderai| 21 can by adjusted by s|iding the connection member in the directions z1and z2, depending on the conditions of the ground 10 and/or depending on theform of the ground 10. When the desired position of the support unit 1 hasbeen achieved, enab|ing stabilization of the ladder 19, the supporting leg 7 isrotated to the active position. ln the active position of the supporting leg 7 the edge portion 9 of thesupporting leg 7 abuts the opposite surface 8 of the side rai| 21 of the ladder19. The edge portion 9 abutting the opposite surface 8 causes creation offriction forces between the edge portion 9 and the opposite surface 8. Thefriction forces between the edge portion 9 and the opposite surface 8contribute to locking of the support unit 1 at the desired position along the siderai| 21 _ Thereby, the support unit 1 can be locked at the side rai| 21 simply byrotating the supporting leg 7 to the active position.

The friction forces increase when a user is climbing on the ladder 19 due to theweight of the user. The weight of the user causes a pressure force F to act onthe ladder 19 and on the supporting leg 7 which force contributes to anincrease the friction forces between the edge portion and the opposite surface8. Thereby, the stability of the ladder 19 may be improved during the use of theladder thanks to the friction forces locking the support unit 1 at the side rai| 21.

The edge portion 9 may protrude at least 2 mm from the surface 5 in the activeposition of the supporting leg 5.

According to the first embodiment, see Fig 5.1 and Fig. 5.2, the connectionmember 3 comprises a base plate 13. The base plate 13 comprises thesurface 5. Thus, the surface 5 is one of the surfaces of the base plate 13 whichsurface 5 is arranged to face the opposite surface 8 of the side rai| 21 of theladder 19. ln the first embodiment, the plates of the connection part 4 extendperpendicularly from the base plate 13, in particular from a surface beingopposite to the surface 5. 11 The base plate 13 comprises an opening 15. ln the first embodiment, theopening 15 is located between the plates of the connection part 4.

The edge portion 9 is arranged to extend through the opening 15 and therebythrough the plate 13 and through the surface 5 in the active position of thesupporting leg 7. Thus form and the size of the opening 15 is adapted to theform and the size of the supporting leg 7 such that the edge portion 9 of thesupporting leg 7 can be displaced through the opening 15 and can reach theopposite surface 8 of a side rail in the active position of the supporting leg 7.

The supporting leg 7 may form a rectangular cross-sectional shape. The shapeof the opening 15 may also be rectangular. The dimension of the opening 15need to be greater than the dimensions of edge portion 9 of the supporting leg7 to enable the edge portion 9 of the supporting leg 7 can be displaced throughthe opening 15.

According to the second embodiment illustrated in Fig. 6, the connectionmember 3 may have a rectangular cross section and being arranged to partlyenclose the side rail 21 when the connection member 3 has been connected tothe side rail 21. Thus, the connection member 3 may be slide along the outersurface of the side rail 21.

As illustrated in Fig. 7, the ground support element 17 may comprise twoseparated support plates 23 angled in relation to each other by a groundsupport angle ß. The ground support angle ß may for example be between 35and 120 degrees. According to an embodiment each of the ground supportelements 17 is attached to the supporting leg 7 by welding.

The present invention is no limited to the embodiments disclosed but may bevaried and modified within the scope of the following claims.

Claims

1. 2

2. Claims 1 _

3. A support unit (1) for a Iadder (19), comprising: - connection member (3) configured for removably connecting the supportunit (1) to a side rail (21) of the ladder (19), wherein the connectionmember (3) comprises a surface (5) arranged for facing an oppositesurface (8) of the side rail (21) and - a supporting leg (7) rotatabiy connected to said connection member (3)and arranged to be rotated around an axis of rotation (a) relatively theconnection member (3) between a rest position and an active position,wherein in said active position the supporting leg (7) forms an angle (d)of inclination with said surface (5) of the connection member (3) and insaid rest position is arranged to permit the connection member (3) toslide along the side rail (21 ), characterized in that in said active position an edge portion (9) of the supporting leg (7) extends through the surface (5) to protrude from said surface (5) and to engage the opposite surface (8) of the side rail (21). _ The support unit (1) according to claim 1, wherein the edge portion (9) is arranged to create friction forces between the edge portion (9) and theopposite surface (8) of the side rail (21) in order to lock the support unit (1)at the side rail (21).

4. The support unit (1) according to claim 1 or 2, wherein in said rest position,the supporting leg (7) is positioned substantially parallel with the surface (s). _ The support unit (1) according to any of claims 1 to 3, wherein said connection member (3) comprises a plate (13) comprising said surface (5),wherein the plate (13) comprises an opening (15) and said edge portion (9)is arranged to extend through the opening (15) and thereby through saidsurface (5) in the active position of the supporting leg (7). 13

5. The support unit (1) according to any of claims 1 to 4, wherein saidconnection member (3) has a rectangular cross section and is arranged topartly enclose the side rai| when the connection member (3) has beenconnected to the side rai|.

6. The support unit (1) according to any of claims 1 to 5, wherein the edgeportion (9) protrudes at least 2 mm from the surface (5) in said activeposition of the supporting leg (5).

7. The support unit (1) according to any of claims 1 to 6, wherein thesupporting leg (7) comprises a ground support element (17).

8. The support unit (1) according to claim 7, wherein the ground supportelement (17) comprises two separated support plates (23) angled inrelation to each other.

9. The support unit (1) according to claim 7 or 8, wherein the ground supportelement (17) is attached to the supporting leg (7) by welding.

10.The support unit (1) according to any of claims 1 to 9, wherein theconnection member (3) and/or the supporting leg (7) are made ofaluminium.

11.A ladder (19) comprising two side rails (21) and at least one support unit (1)according to any of claims 1 to 10, preferably the ladder (19) comprises twosupport units (1) arranged at each side rai| (21) of the ladder (19).

12.The ladder (19) according to claim 11, wherein each of the side rails (21) ofthe ladder (19) has a rectangular cross section or a circular cross section.