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Title:
LADDER WITH TELESCOPIC STABILIZER
Document Type and Number:
WIPO Patent Application WO/2018/185693
Kind Code:
A1
Abstract:
A ladder (1) includes first and second rails (2,4) spaced apart and with rungs (6) in between. The rails define first and second ladder sides. The ladder has a telescopic stabilizer bar (8) at its foot that includes elongate first and second stabilizer portions (10, 12). Each stabilizer portion is in sliding engagement with a connector bar (18) extending transversely between the first and second rails (2,4). The first and second stabilizer portions (10,12) are slideable along the connector bar (18) from a first, stowed, position where they are in an at least partially overlapping relationship, with the connector bar in between. The stabilizer portions (10,12) can be slid to a second, in use, position where at least one of the stabilizer portions is slid along the connector bar (18) to extend the telescopic stabilizer.

Inventors:
PARKER, Tom (105 Halfway Rd, Jamestown, Pennsylvania, 16134, US)
Application Number:
IB2018/052352
Publication Date:
October 11, 2018
Filing Date:
April 05, 2018
Export Citation:
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Assignee:
WERNER INTERNATIONAL POC GMBH (M├╝hlentalstrasse 38, 8200 Schaffhausen, 8200, CH)
International Classes:
E06C7/42
Foreign References:
JPS6419799U1989-01-31
GB2529731A2016-03-02
US5082088A1992-01-21
DE202015007608U12016-01-28
Attorney, Agent or Firm:
CHAPMAN, Paul (Marks & Clerk LLP, 40 Torphichen Street, Edinburgh EH3 8JB, EH3 8EG, GB)
Download PDF:
Claims:
CLAIMS:

1 . A ladder comprising:

first and second rails spaced apart and with rungs in between, the rails defining first and second ladder sides; and

a telescopic stabilizer bar disposed at the foot of the ladder, the telescopic stabilizer bar comprising elongate first and second stabilizer portions, each stabilizer portion in sliding engagement with a connector bar extending transversely between the first and second rails,

wherein the first and second stabilizer portions are slideable along the connector bar from :

a first, stowed, position where the first and second stabilizer portions are in an at least partially overlapping relationship, with the connector bar in between;

to a second, in use, position where at least one of the stabilizer portions is slid along the connector bar to extend the telescopic stabilizer.

2. The ladder of claim 1 wherein, when fully extended, the first and second stabilizer portions extend beyond the respective ladder side to substantially the same extent. 3. The ladder of claim 1 wherein the connector bar is laterally slideable towards either ladder side.

4. The ladder of any preceding claim wherein the telescopic stabilizer bar is mounted beneath the extreme ends of the first and second rails.

5. The ladder of any one of claimsl to 4 wherein the telescopic stabilizer bar is mounted to a side of each of the first and second ladder rails, on one face of the ladder, so that the sliding action is in a plane parallel with the principal plane of the ladder as defined by the rails and the rungs in between.

6. The ladder of any preceding claim wherein the telescopic stabilizer bar is mounted by a bracket or brackets at the foot of each of the first and second rails.

7. The ladder of claim 6 wherein each bracket takes the form of a loop, through which at least one of the stabilizer portions and/or the connector bar may be slid.

8. The ladder of any preceding claim wherein the telescopic stabilizer bar is held captively to the ladder.

9. The ladder of claim 8 wherein the telescopic stabilizer bar is mounted to a bracket in the form of a loop at the foot of each ladder rail and the loop retains the stabilizer bar by virtue of at least one of the stabilizer portions having an increase in diameter at or near an end.

10. The ladder of claim 9 wherein the increase in diameter of a stabilizer portion is by means of a foot fitted at or near the outwards most end of the stabilizer protion.

1 1 . The ladder of any preceding claim wherein a stabilizer portion is gripped by brackets, attached along the length of the connector bar, that allow the sliding motion. 12. The ladder of any one of claims 1 to 10 wherein sliding engagement of a stabilizer portion to the connector bar is by means of;

at least one longitudinally extending flange or other formation on a stabilizer portion fitting into a corresponding longitudinally extending groove in the connector bar;

or

at least one longitudinally extending flange or other formation on the connector bar fitting into a corresponding longitudinally extending groove on a stabilizer portion.

13. The ladder of claim 12 wherein the first and second stabilizer portions each take the form of an elongate bar having a generally C shaped cross section along its length.

14. The ladder of claim 13 wherein the ends of at least one of the C shaped cross section stabilizer bars are formed by a longitudinally extending downwards directed flange and a longitudinally extending upwards directed flange. 15. The ladder of claim 13 or claim 14 wherein the connector bar is provided with a first a first groove along its top edge and a second groove provided along its bottom edge, the grooves being for receiving the ends of the C shape of the first stabilizer portion.

16. The ladder of claim 15 wherein the first and second grooves of the connector bar also receive the ends of the C shape of the second stabilizer portion.

17. The ladder of claim 15 wherein the connector bar further comprises a third groove along its top edge and a fourth groove along its bottom edge for receiving the ends of the C shape of the second stabilizer portion.

18. The ladder of claim 12 or claim 13 wherein the connector bar has a generally H shaped cross section.

19. The ladder of any preceding claim wherein at least one of the first and second stabilizer portions is provided with a stop, to limit sliding relative to the connector bar.

20. The ladder of claim 19 wherein a stop is provided between a connector bar and a stabilizer portion.

21 . A telescopic stabilizer bar and fittings for securing to the foot of a ladder;

the telescopic stabilizer bar comprising elongate first and second stabilizer portions, each stabilizer portion in sliding engagement with a connector bar extending, in use, transversely between the first and second rails of a ladder having first and second rails spaced apart and with rungs in between, the rails defining first and second ladder sides;

wherein the first and second stabilizer portions are slideable along the connector bar from :

a first, stowed, position where the first and second stabilizer portions are in an at least partially overlapping relationship, with the connector bar in between;

to a second, in use, position where at least one of the stabilizer portions is slid along the connector bar to extend the telescopic stabilizer.

Description:
Ladder with Telescopic Stabilizer

Field of the Invention

The present invention relates to ladders fitted with stabilizer bars and a stabilizer bar for fitting to a ladder, to reduce the risk of falling sideways, in use.

Background to the Invention

The use of a ladder presents well known challenges in respect of safety to a user. A ladder allows quick access to a working position at a height, but if not correctly placed and/or secured, slippage can result in a fall for the user.

Various forms of ladder stabilizing device are known. However, these can be relatively mechanically complex or cumbersome. Some stabilizer devices attached to a ladder may significantly increase the dimensions of the ladder, even when in a stowed position. This makes carrying and storing the ladder more awkward. Some stabilizer devices are detachable from the ladder to allow separate storage or transport. This approach may make routine compliance with safe practice less certain. Furthermore detachable parts may be mislaid.

Accordingly there remains a desire for improved ladder and associated ladder stabilizer combinations.

Description of the Invention

According to a first aspect the present invention provides a ladder comprising:

first and second rails spaced apart and with rungs in between, the rails defining first and second ladder sides; and

a telescopic stabilizer bar disposed at the foot of the ladder, the telescopic stabilizer bar comprising elongate first and second stabilizer portions, each stabilizer portion in sliding engagement with a connector bar extending transversely between the first and second rails,

wherein the first and second stabilizer portions are slideable along the connector bar from :

a first, stowed, position where the first and second stabilizer portions are in an at least partially overlapping relationship, with the connector bar in between;

to a second, in use, position where at least one of the stabilizer portions is slid along the connector bar to extend the telescopic stabilizer. When the stabilizer bar is in the second, in use, position at least one of the stabilizer portions has been extended laterally and can engage the ground at a distance beyond at least one of the ladder sides, supporting a load applied via the ladder and thus aiding in preventing the ladder from falling sideways.

Both stabilizer portions will normally be slid along the connector bar, in opposite directions, to achieve a second position where the first stabilizer portion is extended laterally beyond the first rail and the second stabilizer portion is extended laterally beyond the second rail to provide improved stability. When a sideways load is applied to the ladder in either direction the extended stabilizer bar provides support and resistance to a sideways fall of the ladder. The stabilizer portions may extend to beyond both ladder sides, to the same or substantially the same extent.

In some circumstances it may be desirable for the stabilizer bar to extend more to one side or the other. Thus the amount of extension of each stabilizer portion i.e. the amount the stabilizer portion is slid along the connector bar, can be varied.

However, it may be generally desirable that a substantial portion of, or even all of, the available length of the stabilizer bar is employed when the ladder is in use, to provide satisfactory stability. To achieve maximum length for the stabilizer bar both stabilizer portions are slid away from each other to the maximum extent allowed for in the design.

To use a suitable length of, even a full length of, the stabilizer bar and still allow the stabilizer bar to extend more to one side or the other of the ladder, the connector bar may be slideable towards at least one ladder side. Typically the connector bar is slideable towards either ladder side. Thus the extended stabilizer bar may be centred on the ladder, with a stabilizer portion extending to the same or substantially the same extent to either side; or the stabilizer bar may be slid more to one side than the other, as the connector bar is itself slideable relative to the ladder rails.

The stabilizer bar is disposed at the foot of the ladder. This allows engagement with the ground, at least when the stabilizer bar is extended to a second position. The stabilizer bar may be mounted beneath the extreme ends of the ladder rails. In such an arrangement the stabilizer bar may engage the ground, supporting the whole weight of the ladder when in use, even when the stabilizer bar is in the first, stowed, position. Alternatively the stabilizer bar may be mounted to a side of each of the ladder rails on one face of the ladder so that sliding action of the stabilizer portions is in a plane parallel with the principal plane of the ladder as defined by the rails and the rungs in between.

Mounting of the stabilizer bar to the foot of the ladder may be by a bracket or brackets at the foot of each rail. Each bracket may take the form of a loop, through which at least one of the stabilizer portions and/or the connector bar (if slideable) may be slid. Conveniently the stabilizer bar is held captively to the ladder i.e. it is not detachable in normal use, but may be removable for maintenance repair or replacement. For example the connector bar is fixed to a bracket or brackets that mount the stabilizer bar to the ladder. Where the connector bar is slideable a bracket or brackets mounting the stabilizer bar may allow this but the stabilizer bar may still be held captive. For example where the stabilizer bar is mounted to a bracket in the form of a loop at the foot of each ladder rail the loop may retain the stabilizer bar by virtue of at least one of the stabilizer portions having an increase in diameter at or near an end.

Conveniently this increase in diameter may be achieved by feet fitted at or near each outward end of each stabilizer portion. Feet are typically provided at each end of the stabiliser bar to give good contact with the ground in use of the ladder and stabilizer bar. The feet may be height adjustable feet, to allow levelling of the ladder, even if the ground is somewhat uneven. The first and second stabilizer portions are each in sliding engagement with the connector bar, i.e. they can be slid along the connector bar. The sliding engagement can be achieved in various ways. For example a stabilizer portion can be gripped by brackets attached along the length of the connector bar that allow the sliding motion. Alternatively sliding engagement may be by means of at least one longitudinally extending flange or other formation on a stabilizer portion fitting into a corresponding longitudinally extending groove in the connector bar. The opposite arrangement; at least one longitudinally extending flange or other formation on the connector bar fitting into a corresponding longitudinally extending groove on a stabilizer portion can also serve. Conveniently the first stabilizer portion may take the form of an elongate bar having a generally C shaped cross section along its length. The connector bar may take the form of an elongate bar having a first groove provided along its top edge and a second groove provided along its bottom edge. The ends of the C shape may be, respectively, a longitudinally extending downwards directed flange of the first stabilizer portion and a longitudinally extending upwards directed flange of the first stabilizer portion. The ends of the C fit into the first and second grooves of the connector bar to locate the first stabilizer portion alongside the connector bar and allow sliding motion. In such an arrangement the second stabilizer portion may also take the form of an elongate bar having a generally C shaped cross section along its length. The ends of the C of the second stabilizer portion may also be provided as a downwards directed flange and an upwards directed flange. The second stabiliser portion is located alongside the opposite side of the connector bar to that of the first stabilizer bar. The ends of the C of the second stabilizer may fit into corresponding third and fourth grooves along the top and bottom edges of the connector bar; for sliding engagement i.e. the two stabilizer portions fit to either side of the connector bar with the open sides of their C shaped cross sections facing each other.

In an alternative and compact arrangement, rather than having four grooves, two each on the top and bottom edges of the connector bar, the connector bar may be provided with only two grooves one along its top edge and the other along its bottom edge. Thus the connector bar may have a generally H shaped cross section. Viewed in cross section or end elevation, the top ends (in use) of the C shaped stabilizer portions both fit downwardly into the single groove along the top edge of the connector bar and the corresponding bottom ends of the C shaped stabilizer portions both fit upwardly into the single groove along the bottom end of the connector bar.

To provide secure connection between a C shaped cross section stabilizer portion and an H shaped cross section connector bar the stabilizer portion may have additional features. For example a longitudinally extending flange fitting closely to the outside of the upper and/or the lower arm of the H about which the C shape fits; as shown hereafter and with reference to a specific embodiment. When in the first stowed position the first and second stabilizer portions are in an at least partially overlapping relationship, with the connector bar in between. Thus the stabilizer portions are also overlapping the connector bar. When a stabilizer portion is slid along the connector bar to extend the length of the stabilizer bar it is desirable that the stabilizer portion remains in an overlapping relationship with the connector bar to provide a good connection between portion and bar that can support the loadings expected to occur in use. Thus each stabilizer portion may be provided with a stop, to limit lateral sliding relative to the connector bar, to ensure the desired amount of overlapping engagement, even when in the most extended position. A stop may be provided between the connector bar and the stabilizer portion. For example an outwards directed protrusion on the connector bar that interacts with a corresponding inwards directed protrusion on a stabilizer portion to prevent sliding beyond the desired extent.

Alternatively where the connector bar does not slide laterally but is fixed, a stop could be provided between the stabilizer portion and a ladder rail or a bracket through which the stabilizer portion slides. Such a stop may be a protrusion on the stabilizer portion that cannot pass the ladder rail or a bracket.

Where the connector bar itself slides, suitable stops may be provided to limit the possible extent of slide with respect to the ladder, e.g. stops provided between the connector bar and a ladder rail or a bracket on a ladder rail. The stop arrangements discussed above can allow the stabilizer bar to be deployed only within desired parameters with respect to the amount of extension.

Conveniently the stabilizer bar is held in its first position until an operator decides to deploy one or both of the stabilizer portions. This may be achieved by releasable mechanical fixings such as hooks, latches and the like. Similarly releasable fixings may be employed to hold the stabilizer portions in a deployed position, when the ladder is in use.

As the telescopic stabilizer described herein includes stabilizer portions in sliding engagement with a connector bar, it is not required that the stabilizer bar be provided with a housing from which stabilizer portions extend to an in use position.. The connector bar provides support for the stabilizer portions by virtue of the sliding engagement. Thus a less complex arrangement, in manufacture and/or use may be provided.

Advantageously the stabilizer portions are, or are substantially of, the same length or slightly longer than the distance between the ladder rails. Similarly the connector bar can be of a similar length to the distance between the ladder rails. Such lengths allow a good maximum length to the stabilizer bar when deployed in the second position without the arrangement having to extend much beyond the width of the ladder when in the first, stowed position.

Conveniently for consumers, a ladder and stabilizer bar arrangement in accordance with the first aspect of the invention may be supplied as a complete apparatus. However, a stabilizer bar and fittings for securing to a ladder may be supplied to retro fit to existing ladders or for a ladder supplier to fit to new ladders.

Thus according to a second aspect the present invention provides:

a telescopic stabilizer bar and fittings for securing to the foot of a ladder;

the telescopic stabilizer bar comprising elongate first and second stabilizer portions, each stabilizer portion in sliding engagement with a connector bar extending, in use, transversely between the first and second rails of a ladder having first and second rails spaced apart and with rungs in between, the rails defining first and second ladder sides;

wherein the first and second stabilizer portions are slideable along the connector bar from :

a first, stowed, position where the first and second stabilizer portions are in an at least partially overlapping relationship, with the connector bar in between;

to a second, in use, position where at least one of the stabilizer portions is slid along the connector bar to extend the telescopic stabilizer.

The fittings for securing the telescopic stabilizer bar to a ladder may include one or more brackets fixable to the foot of a ladder by releasable or non-releasable fixings such as screws, bolts, rivets and the like. In some examples the connector bar itself may be directly connectable to the ladder by releasable or non-releasable fixings. Where brackets are employed there may be may be of any of the forms described herein for use in a ladder according to the first aspect of the invention.

Thus fixing to the foot of a ladder may be by a bracket or brackets at the foot of each rail as discussed herein with respect to the first aspect of the invention.

More generally all the features discussed herein with respect to the first aspect of the invention may be provided for a telescopic stabilizer bar and fittings provided in accordance with the second aspect of the invention, for fitting to a ladder.

The supplied stabilizer bar and fittings combination may include further items such as releasable or non-releasable fixings such as screws, bolts and/or rivets for use in fixing the stabilizer bar to a ladder. Brief Description of the Drawings

Figure 1 shows the lower part of a ladder fitted with a telescopic stabilizer bar that is in a stowed position;

Figure 2 shows the arrangement of figure 1 with the telescopic stabilizer bar in an extended position;

Figure 3 shows the arrangement of figure 1 with the telescopic stabilizer bar in another extended position;

Figure 4 shows, in perspective view, a telescopic stabilizer bar in an extended position; Figure 5 shows, in an end elevation, the telescopic stabilizer bar of figure 4; and Figure 6 shows the use of stop arrangements with the telescopic stabilizer bar of figure 5.

Detailed Description of the Invention with Reference to Some Embodiments

Figure 1 shows in perspective schematic view the lower part of a ladder 1 having left and right side rails 2,4 spaced apart with rungs 6 in between. A telescopic stabilizer bar 8 is at the foot of ladder 1 , mounted below the extreme ends of rails 2,4. The stabilizer bar 8 has first and second stabilizer portions 10, 12 in a first, stowed position, overlapping each other and substantially inside the width of the ladder as defined by rails 2,4. Also visible in this view are feet 16 at the ends of portions 10,12 and having ground engaging bases 17. The telescopic stabilizer bar 8 is held captive to ladder 1 by brackets 14 through which stabilizer portions may slide. In figure 2 stabilizer portions 10, 12 have been slid to the left and right respectively, to allow the stabilizer bar 8 to engage the ground at a distance beyond the sides of the ladder as defined by rails 2,4. In this view the extended stabilizer bar 8 extends equally to both sides of the ladder 1 . In this second, extended, position a connector bar 18 can be seen. The stabilizer portions 10, 12 are in sliding engagement with connector bar 18. To provide strength and rigidity to the arrangement, overlaps, indicated by brackets 20, are provided between stabilizer portions 10, 12 and connector bar 18.

Figure 3 shows a similar arrangement to that of figure 2 except that the extended stabilizer bar 8 extends further to the left than to the right. This has been achieved by sliding the connector bar 18 left, away from the central position shown in figure 2.

Figures 4 and 5 show a stabilizer bar 8 of the type shown in figures 1 to 3 but not fitted to a ladder and with the feet removed, to allow appreciation of various features. In perspective figure 4, the bar 8 is shown in a fully extended position with the stabilizer portions slid away from each other in opposite directions, as suggested by arrows A and B. End 22 of stabilizer portion 12 can be seen to have a generally C shape.

Figure 5 is an elevation from direction X indicated on figure 4. Here it can be seen that the connector bar 18 is H shaped along its length, having a top groove 24 and a bottom groove 26 between the arms of the H. It can also be seen that the stabilizer portions 10, 12 have a generally C shaped cross section along their lengths - with the open sides of their C shaped cross sections facing each other.

The ends of each C are formed by flanges 28, 30 that sit in grooves 24, 26 respectively. Secure but sliding connection between connector bar 18 and stabilizer portions 10, 12 is further achieved by additional flanges 32, 34 fitting to the outside of the arms of H shaped (in cross section) connector bar 18. The combination of flanges 32, 34 with respective flanges 28, 30 gives a close fit to the connector bar arms. Figure 6 shows the same view as figure 5, but illustrating the use of stops to limit the amount of extension of stabilizer portions 10, 12. With reference to figure 4, stabilizer portion 12 is prevented from moving further in the direction of arrow B by a stop located, as suggested by arrow S, within the region of overlap 20 and inside the connector bar stabilizer portion assembly. As can be seen in figure 6 this stop includes a protrusion 36 extending outwards from connector bar 18 towards stabilizer portion 12. A corresponding protrusion 38 extends from stabilizer portion 12 towards connector bar 18 and cannot pass protrusion 36 to allow further extension of portion 12 in direction of arrow B. A similar stop is provided at S1 (figure 4) making use of protrusions 40 and 42 (figure 6) to prevent further extension of stabilizer portion 10 in the direction of arrow A.