WO2003100204A1

WO2003100204A1 - A securing device for a ladder

Info

Publication number: WO2003100204A1
Application number: PCT/NO2003/000172
Authority: WO
Inventors: Terje H. Houen
Original assignee: Houen Terje H
Priority date: 2002-05-28
Filing date: 2003-05-27
Publication date: 2003-12-04
Also published as: NO20022504L; AU2003234365A1; NO20022504D0

Abstract

A securing device for a ladder (10, 12) is to secure this while the lower parts of the ladder are partly supported against the base, the upper parts thereof partly supported, via the securing device (14, 16, 20), against a support surface (18), for example a house facade surface. The securing device (14, 16, 20) partly comprises wall-fixed fittings (14) provided with a first securing organ in the form of vertical slits (40), in which tongue-like, elastic blocking organs (52) acting from above preferably are provided to an upper insertion opening; partly comprises spacer arms (16) having one end connected to the ladder top via a fastening device (20) of the securing device, and carrying at the opposite end a second engagement-based securing organ (36, 38) formed with a narrower and wider portion (38 and 36) relative to the direction of the slit width, for releasable engagement with the securing slits (40) of the wall-fixed fittings (14).

Description

A SECURING DEVICE FOR A LADDER

This invention concerns a securing device for a ladder, preferably a ladder of the type used for example when painting house facades, in order to secure the ladder in its steeply inclined position of use, in which loads are transmitted onto and supported by a substantially horizontal base and, at its upper end portion, supported against said house facade surface or similar surface via the securing device, the device comprising at least one spacer arm extending transversely to the longitudinal direction of the ladder sides, thereby keeping the upper ladder portion at a distance from said surface while in position of use, the surface being permanently provided with fittings, which are included in the securing device, and which comprise first securing organs cooperating releasably with second securing organs provided to the upper end portion of the ladder.

The prior art is illustrated by, for example, NO Bl 303.790; EP Al 0.355.504 and US 2.256.452, 4.339.020 and also 5.113.973. For the securing device according to the present invention the primary object is to ensure that an inclined ladder, when in position of use, does not slide sideways along the surface forming a support surface for the upper end portion of the ladder, or that the ladder swings backwards. Keeping the upper end portion of the ladder at a certain distance from said support surface thus constitutes a subordinate, secondary object of the present invention, and this is also known per se in connection with such ladder securing devices. Likewise, the invention is aimed at preventing downward sliding of the ladder top from an overlying desired support location to an underlying undesired support location.

US patent publication no. 2.256.452 thus discloses a ladder securing device, the object of which has been to maintain a free interstice between the upper end of the ladder and a surface providing the necessary support of the upper end portion of the ladder and accommodating the horizontal force component of the load.

According to this US patent publication a plate is provided with downward/forward slanting open suspension hooks, which are to be suspended in a horizontal rod, the side of which is suspended from overlying wires, cords or similar rope-like elements. The horizontal suspension rod for plate hooks form part of the securing device for a ladder comprising, likewise, gripping organs connected to the upper end of the ladder, the organs consisting of U-bows having a long upper U-branch and a short lower U-branch, said U-bows opening in one side direction away from the upper end of the ladder, approximately perpendicular to longitudinal direction of the ladder sides. When using this securing device for a ladder, the upper end portion of the ladder is not secured against tilting or displacement movements.

Rigidly mounted lock fittings or similar stop devices on the surface which is to support the upper end portion of the ladder via the securing device, is known per se from NO Bl 303.790, which concerns a very bulky and complicated ladder portion located somewhat closer to the upper end of the ladder than its lower end.

EP Al 0.355.504 concerns a distance-maintaining device for a ladder relative to a vertical support surface that may be painted, or for use where repair works are to be carried out. No securing device exists.

US patent publication no. 4.339.020 relates to a support device for the upper end, when used, of a ladder, placed directly opposite a vertical support surface. This is a support device formed exclusively with the aim of not influencing/damaging the surface layer of the support surface onto which the ladder leans against. No securing device exists.

US patent publication no. 5.113.973 concerns a distance- maintaining device for the upper end of a ladder in order to keep this at a distance from the support surface. This distance-maintaining device provides cushions against the support surface, these cushions being completely incapable of preventing undesired movements of a ladder when in its position of use. No securing device exists. The object of this invention therefore has been to provide, by using simple and inexpensive means, a securing device wherein said defects, disadvantages and user restrictions of the prior are eliminated or strongly reduced.

Said object is realised by means of a securing device of the type further disclosed in the preamble of the patent claim 1, and which also is formed in correspondence with the characterising clause of patent claim 1.

Rigidly mounted fittings that provide said first securing organs are positioned in those places of the support surface corresponding to those ladder set-up positions expected to be used in connection with, for example, painting the support surface when forming a house facade surface. As noted, said first securing organs constitute parts of the securing device according to the invention and cooperate releasably with corresponding second securing organs provided to external, free ends of spacer arms connected to the ladder top. Releasing and cancellation of the mutual, stopping/securing engagement between cooperating securing organs only may be activated when using certain, deliberate actuating movements/ grips. For example, the releasing may be arranged in a manner requiring a special manoeuvring of the ladder while a person is on the ground and is pulling the ladder as far as possible away from the wall, thereby bringing the mutually cooperating, first and second securing organs on the support wall and the ladder out of their stopping engagement to release the ladder.

Between the spacer arms and the top portion of the ladder the securing device comprises an intermediate fastening device that comprises resilient/shock-absorbing organs engaging the connection ends of the spacer arms. Such resilient/shock- absorbing organs ensure that too large displacement forces are not transmitted from the ladder onto the wall-fixed securing fittings in the plane of the support surface if the ladder, at its lower end portion, should settle somewhat into the base. In a practical embodiment of the invention, such a resilient suspension of the external ends of the spacer arms will also ensure that the spacer arms' securing organs engaging the fittings' securing organs, are fixed against lower position points within these and also balances horizontal differences in position between a pair of wall fittings.

Due to the design of the components entering into the securing device, the securing device may be placed somewhat below the ladder top. This renders possible to carry out work from the ladder above eaves troughs, roof ridges etc., in which the wall-fixed fittings having securing organs are placed immediately below these.

o With this constructively and functionally simple securing device arranged in active position, a steeply inclined ladder in its position of use is secured against both sliding sideways and tipping backwards, or against displacing upwards/downwards . The securing devices is deactivated by s means of simple, distinctive grips carried out from a position on the ground of the ladder set-up, for example as disclosed previously.

At their free ends, the securing organs of the spacer arms preferably may be formed as external heads on narrower handle portions. For cooperation, each of the wall-fixed securing fittings thereby provides an upright stop slit defined by an open/closed upper end and a closed lower end.

The upper closed/open end of the securing slit is open upward within a plane at a certain distance from the support wall surface and closed upward within another, and thus parallel, plane at a shorter distance from the support wall surface.

In one embodiment, these open/closed upper openings aimed upwards are kept apart by means of a downward directed tongue extending obliquely out from the support wall surface in a steep position, in which the base portion of the tongue closes the upper opening at the inner upright plane, while at an external plane, in front of the tongue, the upper open opening portion is wider than the diameter of said securing head.

The ladder-fixed securing heads on the handle-like connection elements thus are engaged with the stop slits of the wall- fixed securing organs at the slits' upper, wider insertion/ pullout portion, after which the securing heads, having their handle portions engaged with the stop slits, are lowered down past the lower free end of the tongue. The handle of the securing head thereby has a diameter being insignificantly smaller than the width of the slit.

When the securing heads on the handles have moved below the lower ends of associated tongues, a very reliable securing position has been established, inasmuch as unintended upward movement of at least one of a pair of wall-fixed securing fittings at the ladder top, causes the securing head to enter below the tongue, thereby being blocked and inhibited from releasing the engagement. In most such cases, the downwardly directed tongues at both stop slits will prevent the securing heads from getting an opportunity to release their engagement with the wall-fixed securing fittings.

Non-restricting examples of preferred embodiments are explained more explicitly in the following, referring to the accompanying drawing, in which:

Fig. 1 shows a perspective overview in part, in which the ladder securing device is illustrated in connection with a wall-fixed pair of securing fittings positioned below the ridgepole of a house, immediately above a window, and in which the spacer arms of the securing device being provided to the ladder top are connected to the securing fittings and secured to these;

Fig. 2 is a part view at larger scale, seen from the side, showing the securing fitting and the upper end portion of the ladder;

Fig. 3 shows in perspective, and at even larger scale than that of Fig. 2, a separate securing fitting;

Fig. 4 shows the securing fitting of Fig. 3 in front view;

Fig. 5 is a section along line V-V of Fig. 4;

Fig. 6 shows, at somewhat smaller scale than that of figures 3-5, the securing device of the ladder in active position. On the drawings, reference numeral 10 and 12 denote sides and ladder steps of an ordinary ladder; cf. figures 1 and 6.

Fig. 1 shows a perspective part view of the upper portion of a house having a ridge roof and a window in the end wall region of the ridge roof portion. A pair of securing fittings is fixed above the window, the fittings generally denoted by 14. At the free end of spacer arms 16 fixed to the ladder top and comprised in the securing device, each of the securing organs of the securing fittings 14 consisting of first securing organs described hereinafter, is cooperatingly and releasably connected to second securing organs.

By means of the disclosed securing device the ladder 10, 12 is kept in steeply inclined user position at a distance from the support surface 18 of the house facade, the ladder top thereby not bearing directly against the support surface 18, but only indirectly via the securing device 14, 16, which comprises a fastening device 20 besides the wall-fixed fittings 14 and spacer arms 16; see figures 2 and 6.

The securing device's fastening device 20 to the ladder top, cf. figures 2 and 6, comprises a clamping frame having, relative to the spacer arms 16, a transverse beam 22 extending parallel to ladder steps 12 and being formed with recesses (not shown in Fig. 6) for pivotal accommodation of adjacent spacer arm ends (see pivot point 24 of Fig. 2) being spring-loaded individually (see dash-lined spring 26 of Fig. 2) to ensure shock absorption and reduction in those forces transmitted from the ladder to the wall-fixed securing fittings 14. Moreover, this spring suspension device ensures that the securing organs of the spacer arms 16 engaging with the cooperating securing organs of the fittings, are kept in place in these against the lower position and balances horizontal differences in position between the wall-fixed securing fittings 14 of a pair.

The clamping frame of the ladder securing device further comprises screw bolts 28 having long screw shafts extending through the beam 22. Each screw bolt 28 has a fixed head 30 bearing against the surface of the beam AZ facing the support wall 14, and a torque nut in the shape of a wing nut 32 at the opposite end portion. At the end portion of the wing nuts 32, the screw bolt shafts extend between ladder steps and through a relatively short channel iron 34, allowing torqueing of the wing nuts 32 to clamp down a portion of the ladder sides 12 in between the channel iron pieces 34 and the beam 22; cf. Fig. 6.

The shape of said second securing organ carried by the spacer arms is best shown in Fig. 6, each securing organ being shaped as a spherical segment head 36 at the free end of a tapering, as viewed relative to the cross sectional size of the spacer arms 16, and guiding shaft portion 38, which constitutes a part of said second securing organ. However, said second securing organ is better illustrated by denoting it as an engagement organ (the shaft portion 38) having an external thickening (the head 36) that will prevent the pullout of the engagement organ from a slit when in the securing position.

The plane view of Fig. 6 shows that the shaft portion 38 of every second securing organ is engaged with a slit 40 comprised in said first securing organ of the wall-fixed fitting. Moreover, figures 3-5 illustrate said first slit- shaped securing organ in most detail.

According to figures 3-5 said vertical securing slit 40 is formed in a box-shaped hollow body 42 pressed from a rectangular fastening plate 44 having a fastening hole at each corner for fixing to said support surface 18 for permanent fixing by means of screwing/nailing; cf. figures 1, 2 and 6.

A closed lower end 46 confines the securing slit 40 in the wall-fixed securing fitting 14 downwardly. The securing slit 40 is to cooperate with the securing shaft 38, allowing said second securing organ 36, 38 to slide vertically within the slit 40. The end thickening/head 36 of the shaft 38 prevents it from being pulled out of the securing slit 40 in the longitudinal direction of the spacer arms 16 as long as the end thickening/head 36 is located below a wider, upper insertion opening 48 of the slit 40 defined by the oblique side edges 50. The insertion opening 48 has a transverse extent exceeding the transverse dimension of the end thickening 36, which further exceeds the width of the vertically extending slit 40.

The upper region of the insertion opening of the securing slit 40 is provided with a blocking tongue 52, which may be provided with a certain inherent elastic resiliency. From an upper horizontal exit/transition portion, in which the tongue 52 is connected with the fastening plate of the securing fitting 14, the blocking tongue has a pendulous and extended shape. Upon inserting the engagement organ of the second securing organ 36, 38 into the securing slit 40 via the wider insertion opening 48, and upon downward movement of the engagement organ shaft 38 engaged with the slit 40, the free end portion of the blocking tongue 52 is able to be resilient in the direction toward the support wall 18 and allow the end thickening 36 to pass by in a downward direction. After passing of the end thickening, the lower free end of the blocking tongue springs back to the locking position, cf. Fig. 5, in which the underlying end thickening 36 on the shaft portion 38 may not move the blocking tongue 52 to the release position.

The engagement between the first securing organs of the wall- fixed fittings 14, the vertical slit 40 having a closed lower end and partially blocked upper end on the one side, and the second securing organ fixed to the ladder top on the other side, preferably is to be released by a person located on the ground and is capable of pulling the ladder as far as possible from the wall 18, simultaneously pushing the ladder upwards and, by so doing, the part of the securing device connected to the ladder top. Thereby the end thickening may be forcedly guided past the lower free end portion of the blocking tongue 52 and then out through the upper insertion opening 48 of the securing slit 40.

Then the securing organs 36, 38 carried by the ladder top may be engaged with another wall-fixed fitting, pair of fittings 14, respectively.

Obviously the securing fitting 14 will also function without the blocking tongue 52. The spacer arms 16 may be attached to the ladder 10, 12 in many different ways, and they may also function without being spring-loaded.

Claims

P at e nt c l a i m s

1. A securing device (14, 16, 20) for a ladder (10, 12) for securing the ladder in a inclined user position, partially supported against a base at its lower end portion, partially against a support wall surface (18) via a securing device (14, 16, 20), the securing device comprising at least one spacer arm (16) keeping an upper end portion of the ladder at a distance from the support surface (18), in which wall-fixed fittings (14) are provided, preferably permanently, having a first securing organ (40), which together with the securing device (14, 16, 20) carries a second securing organ (36, 38), the or each spacer arm (16) of the securing device (14, 16, 20) being connected to the ladder top via a fastening device ( 20 ) , c h a r a c t e r i z e d i n that the first securing organ (40) of the securing device comprises a securing organ (46, 48) resembling a slit/slot, into which the second securing organ (36, 38) is arranged to engage releasably with.

2. The securing device (14, 16, 20) according to claim 1, c h ar ac ter i z e d in that said first securing organ of each wall-fixed fitting (14) is formed as a vertical slit (40) of uniform width having a wider upper insertion opening (48) and a lower closed end (46), and that the free end of each spacer arm (16) is provided with an external end thickening (36) having a narrower shaft portion (38), the largest transverse dimension of which is insignificantly smaller than the width of the vertical slit (40), while the largest transverse dimension of the end thickening (36) exceeds the width of the slit, but is smaller than the extent of the upper insertion opening (48) in the corresponding direction, the upper insertion region of the slit (40) preferably also being provided with a blocking organ (52) formed and supported in a manner allowing passage of the end thickening (36) from above and downwards, but generally counteracting its movement in the opposite direction, from below and upwards .

3. The securing device (14, 16, 20) according to claim 2, c h ar ac t e r i z e d i n that the blocking organ (52) is in the shape of a of thin plated, freely pendulous and extended tongue providing elastic resiliency and spring-return properties directed toward and away from the support surface (18).

4. The securing device (14, 16, 20) according to claim 1, 2 or 3, c h ar a c t e r i z ed i n that the spacer arm (16), each spacer arm, respectively, is pivotally arranged and spring-loaded (24 and 26) within the fastening device (20) of the securing device.