GB2042041A

GB2042041A - Stabilizing means for a ladder

Info

Publication number: GB2042041A
Application number: GB7905094A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-02-13
Filing date: 1979-02-13
Publication date: 1980-09-17
Also published as: GB2042041B

Abstract

Stabilizing means for a ladder comprise legs 12 with bracing struts 13, the ends of the legs and struts being pivoted to the ladder stiles, the pivot point of the leg 12 being adjustable along the stile so that the lateral extent and height of the ground engaging foot 16 can be varied. The leg 12 may be locked in its adjusted position by various rack and pin arrangements or by a pivotal lever 62 having two teeth 67, 71 for engaging a rack 32 on the stile. The engagement of the teeth in the rack slightly lifts the stile relative to the leg 12 so that the full weight of the ladder is transferred to the feet 16 of legs 12. <IMAGE>

Description

SPECIFICATION Stabilizing means for a ladder The invention relates to a ladder stabilizer, for the lower end of a ladder.

It has been proposed to provide the lower end of a ladder with stabilizing members which provide a more stable base for the ladder. Prior proposals have, however, obstructed the lower rungs of the ladder or have otherwise been cumbersome and inconvenient, and do not provide much stability if the foot of the ladder is on uneven ground.

In this invention, stabilizing means are provided for connection on each side piece of a ladder on its outer side and comprising upper and lower leg parts which are pivotally connected on the outside of the side piece and the upper leg part has a locking member for engagement with the side piece. This locking member can be releasably retained on the side piece at an upper position and at a range of lower positions.

Using this arrangement, the rungs of the ladder are unobstructed. At the upper, or storage position of the locking member, the leg parts lie compactly flat along the ladder side pieces and at the lower positions of the locking member, the leg parts are mutually inclined outwardly from the side pieces so that the lower end of upper leg parts can be engaged on surrounding surfaces. The heights and positions of the two leg parts on opposite sides of the ladder can be adjusted independently, so that they can be used on uneven surfaces, while it is also possible to have one leg part bracing on the ground and the other engaging a wall or other adjacent vertical surface.

The invention also provides an arrangement in which there is a reaction means, such as a toothed rack, on the side piece of the ladder, and the upper leg part has an operating means, such as a pivoting dog, which reacts with the reaction means. When the operating means is pivoted inward, it engages the reaction means and lifts this upwardly with the result that the ladder, to which the reaction means is attached, is lifted bodily upwards.

This lifting action lifts the foot of the ladder off the ground by a small distance and serves to transfer the weight of the ladder from the foot to the outlying leg parts. Thus a wider and hence more stable base for the ladder is provided.

In the accompanying drawings there are shown examples of stabilizing means which may be sold as a kit and are adapted to be fitted to existing types of ladders. The stabilizing means may, however, instead be provided on the ladder in in-shop fitting by the ladder manufacturer.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows in perspective a ladder equipped with one form of stabilizing means; Figures 2 and 3 are vertical sections through the ladder side pieces illustrating the action of the locking means; Figure 4 is a horizontal section through the locking means on the line 4-4 of Fig. 1; Figure 5 shows the stabilizing means in the storage position; Figure 6 shows in perspective a further form of stabilizing means in which a lifting action is achieved; Figure 7 is a vertical section through the device of Fig. 6; Figure 8 is a section on the line 8-8 of Fig.

7 illustrating a catch for the locking device; Figure 9 illustrates an alternative form applicable for ladders having other types of side pieces; Figure 10 shows in perspective one side of a ladder equipped with a further form of stabilizing means which achieves a lifting action; Figure ii to 14 each show a vertical section through the stabilizing means employed on the ladder of Fig. 10, the successive Figures illustrating in sequence the operation of closing the lever means and exerting the lifting action; Figure 15 is a view of the ladder from the front illustrating the lifting action; and Figure 16 is a more detailed view in perspective of the lever means and its associated catch member.

Referring to the drawings wherein like reference numerals indicate like parts, Figs. 1 to 8 show one conventional form of ladder 10.

As illustrated, the ladder 10 is modified by using stabilizing devices comprising outwardly extensible legs 11. These comprise upper and lower metal leg parts 1 2 and 1 3 which are pivotally connected together at a pin 14, forming a knee. A frictional, robust, surfacingengaging pad 16, which may be of hard rubber, pivots on the lower end of the upper leg part 12, on the pin 14.

The lower, shorter, leg 1 3 pivots on a support plate 1 7 riveted on the side piece 1 8 of the ladder. The upper end of the upper longer, leg part 1 2 is pivotally connected to a slider plate 1 9. As can best be seen in Fig. 4, the outer side of the side piece 1 8 is of channel section but may be of any other suitable design. A pair of insert strips 21 are riveted on the inner sides of the channel and their inner edges define with the bottom of the channel a pair of tracks 22 in which the side flanges of the slider plate 1 9 run.The strips 21 provide a track for the sliding plate 1 9 extending from the upper storage position as shown in Fig. 5 to a lower support position above the lower support plate 1 7.

With this arrangement; the position of the slider plate 1 9 can be varied between the storage position, as shown in Fig. 5, in which the leg parts 12 and 1 3 lie flat along the side piece, and a range of lower stabilizing positions one of which is shown in Fig. 1. Where the ground surface is uneven, the slider plate may be brought to lower positions closer to the plate 17, or to higher positions, enabling the pad 16 to engage the ground surface or an adjacent wail surface.

The plate 1 9 is provided with a locking member for locking it in position on the side piece 18, the locking member in the forms shown in Figs. 1 to 5 including a pin 23 which can be inserted into an array of holes 24 formed at desired heights in the side pieces 18.

The extent of the array of holes 24 is such that the pad 1 6 can be held at a range of positions from somewhat below the level of the foot of the ladder to higher positions approaching the storage position of Fig. 5.

A hole 25 is provided at the upper limit of travel of the plate 1 9 to allow it to be anchored in the storage position.

The pin 23 is biased inwardly away from the plate by a spring 26 acting on a collar 27 on the pin. The locking position is shown in Fig. 2. To allow the pin to be held in the retracted position when it is desired to slide the plate 1 9 along the side piece 1 8 the pin is pivotally connected to an operating means in this case a hollow lever 28, through an internal transverse pin 29.

The sides of the lever 28 are formed with inclined camming surfaces 31 at their inner ends. As shown in Fig. 3, the lever 28 can be rocked outwardly against the action of the spring 26 to hold the pin 23 in the retracted position temporarily through the reaction between the camming surfaces 31 and the plate 19.

The arrangement of Figs. 6 to 8 differs in the forms of slider plate and locking member that are used. Instead of using an array of holes such as the holes 24, a toothed rack 32 is connected on the outer side of each side piece 1 8. The rack extends along the side piece 18 over the portion of the side piece's length on which it is desired to retain the slider plate in the lower stabilizing positions, i.e. normally the same extent as the extent of the array of holes 24.

The slider plate 34 which is used, as shown in Fig. 6 has a pair of upstanding lugs 36 between which extends a pivot pin 37. A hollow lever 38 is pivoted on the pin 37 and is formed on the inner side of its upper end with an inwardly-projecting dog 39. A gear may also be used in place of dogs 39.

In use, the lever 38 can be swung inwardly from the released position shown in Fig. 6 in which the dog 39 is clear of the teeth of the rack 32 to the inner, locked position shown in Fig. 7 where the dog 39 engages on the underside of an adjacent tooth of the rack. It is most important to note that with this arrangement as the lever 38 is swung inwardly, the leading edge of the dog 39 engages on the underside of a rack tooth and as the lever 38 is finally moved to its locked position, the dog bodily lifts the tooth, the rack 32, and the ladder to which the rack 32 is attached, relative to the legs 1 2 and 1 3 and to the pad 1 6 which rests solidly on the ground.The effect of raising the ladder bodily by some small distance, which can vary but in general need be no more than about one-quarter of an inch, is to transfer the weight of the ladder from the foot of the ladder to the outlying pads 16, so that the weight-supporting base of the ladder is made much wider and the ladder is effectively stabilized.

The lever 38 is fitted internally with a spring 41 acting between the plate 34 and the inner surface of the lever, so as to normally hold the lever in the outer, released position permitting free movement of the plate. A catch is provided for holding the lever 38 in the inner locked position. As best shown in Fig. 8 the catch comprises a button 42 connected on a stem 43 sliding in a hole in the side of the lever 38. The stem 43 has a tab 44 with a tip 46 biased outwardly by a spring 47. The lip 46 is formed with a bevelled leading edge and as the lever is swung inwardly, the bevelled edge engages a side of a slot 48 in the plate 34 and deflects the tab 44 against the action of the spring 47 to permit the lip 46 to engage behind the side of the slot 48 as shown in Fig; 3.The lever 38 can be released by depressing the button 42 so as to free the lip 46, whereupon the lever is swung outwardly by the action of its internal spring 41.

A small section of toothed rack (indicated at 49 in Fig. 1) may be attached on the upper part of the side piece 1 8 to serve as an achorage for the slider plate 34 at the upper, storage position. This small section 49 may be of soft, yeilding rubber so as to absorb the leverage exerted by the dog 39.

Where the external profile of the ladder does not readily lend itself to forming a sliding track for the upper end of the upper leg part, a fitting may be attached on the ladder side pieces so as to provide a sliding track. An example of such a fitting is shown in Fig. 9, where a rung 49 and a side piece 51 of a ladder are shown in broken lines. A sliding track 52, formed as an extruded section, is riveted on the side piece 51 and includes inturned edge parts 53 which slidingly confine a slider plate 34 of the form shown in Fig. 6, having a lever 38 as the locking member. The central part 54 of the rack can serve to support the toothed rack 32 with which the lever 38 engages.

In the embodiment shown in Figs. 10 to 16, an extruded metal track 61 is attached, for example by screws, on each side piece 1 8.

The track 61 slidingly receives and retains the slider plate 34 and carries the toothed rack 32. The upper end of the slider plate 34 has the raised lugs 36 on which an operating means, in this case a lever 62, is pivoted about the pin 37. The lower end of the slider plate 34 is formed integrally with a hollow transversely extending bridge 63 in the upper surface of which is a recess 64. The upper leg part 12 pivots on a pin 66 passing through the bridge 63.

The slider plate 34 is formed with upper and lower apertures 67 and 68 through which, when the lever 62 is in closed position, upper and lower dogs 69 and 71 extend which are formed integrally with the lever 62.

A catch member 72 is movably connected on the lever 62. As best shown in Fig. 16, the catch member has a central longitudinal slot 73 which receives the lever 62, and is movably retained on the lever by dowel pins 74 which pass through elongated slots 76 through the lever, so that the catch member 72 can be reciprocated relative to the lever 62. A compression spring 77 between the lever 62 and the member 72 urges the catch member downwardly. The lower end of the catch member 62 has an outwardly turned lip 78. In the embodiment shown, the lever 62 is connected to a plastics cover plate 79 on the underside of which the upper surface of the catch member 72 reciprocates, but preferably the cover plate 79 is formed integrally with the lever 62.

In addition it will be noted that the upper leg 1 2 extends beyond the junction of "knee", at 81, with the lower leg 13. The pads 1 6 are located at the extreme lower ends of legs 1 2 in this case.

In use, as with the previously described embodiments, the slider plate 34 is first slid downwardly from the upper storage position so that the upper and lower leg parts 1 2 and 1 3 on either side of the ladder are spread apart until each rubber pad 1 6 engages firmly on the ground.

The lever member 62 is then pressed inwardly as shown in Figs. 11 and 12, and the upper dog 69 engages a tooth of the rack 32 and the levering action lifts the rack upwardly together with the ladder to which the rack is attached.

The lifting action is illustrated in Fig. 15, where the movement of the levers 62 inwardly from the position shown in broken lines causes the foot of the ladder 1 8 to be lifted a small distance clear of the ground, so that the weight of the ladder is transferred to the outlying pads 1 6. The extent of upward lifting need not be large and typically may be about one-quarter of an inch. A satisfactory stabilization is achieved with this lifting action.

As the lever 62 is pressed inwardly, the lower edge of the catch member 72 engages the rounded surface of the bridge 63 as shown in Fig. 1 3 and the catch member is pressed upwardly against the action of the spring 77 until the lever is pressed inwardly sufficiently for the lip 78 to clear the edge of the recess 64 in the bridge 63. The catch member 72 then snaps downward under the action of the spring 77. On release of the lever 62, the spring 41 between the lever 62, and the slider plate 34 presses the lever 62 outwards so that the lip 78 is held pressed into positive engagement with the recess 64, preventing outward movement of the lever 62.

As shown in Figs. 1 3 and 14, at the inward position of the lever 62 the rack 32 is engaged by the second, lower dog 71 as well as by the upper dog 69, so that movement of the slider plate 34 relative to the rack 32 and track 61 is prevented.

The weight of the ladder, and man is thus distributed between the two dogs 69 and 71, and two positions of the rack. If desired, more such dogs or teeth may be provided for still greater load distribution.

Other forms of operating means such as gears may also be used in some cases.

For example spur gears could be used to replace the dogs, or teeth, such gears meshing permanently with the racks. Operating levers could connect with the gears through rachet mechanisms.

As a safeguard against accedental dislodgement of the lever 62, it will be noted that in order to free the lip 78 from the recess 64, it is necessary to simultaneously press the lever 62 inwards-and grasp the catch member 72 between the fingers and slide it upwardly relative to the lever 62. Thus with this arrangement, the catch cannot be freed by an accidental blow striking the mechanism.

As stated above the lower leg part 1 3 is pivotally connected to the upper leg part 1 2 at a point 81 or knee intermediate the ends of the part 1 2. With this arrang'ement the lower leg part is spaced upward from the ground and so can remain clear of the ground surface if the leg 1 2 needs to be extended across a step, and the length of the track 61 can then be made much greater so as to permit a greater extension of legs 12, where needed.

The foregoing is a descirption of a preferred embodiment of the invention which is given here by way of example only. The invention is not to be taken as limited to any of the specific features as described, but comprehends all such variations thereof as come within the scope of the appended claims.

CLAIMS (13 Feb 1979) 1. Stabilizing means for connection on the outer side of the side pieces of a ladder comprising upper and lower leg parts connected together at a pivotal knee, the lower leg part connecting pivotally with a support member adapted to be secured on the side piece of the ladder, and the upper leg part

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. slider plate 34 and carries the toothed rack 32. The upper end of the slider plate 34 has the raised lugs 36 on which an operating means, in this case a lever 62, is pivoted about the pin 37. The lower end of the slider plate 34 is formed integrally with a hollow transversely extending bridge 63 in the upper surface of which is a recess 64. The upper leg part 12 pivots on a pin 66 passing through the bridge 63. The slider plate 34 is formed with upper and lower apertures 67 and 68 through which, when the lever 62 is in closed position, upper and lower dogs 69 and 71 extend which are formed integrally with the lever 62. A catch member 72 is movably connected on the lever 62. As best shown in Fig. 16, the catch member has a central longitudinal slot 73 which receives the lever 62, and is movably retained on the lever by dowel pins 74 which pass through elongated slots 76 through the lever, so that the catch member 72 can be reciprocated relative to the lever 62. A compression spring 77 between the lever 62 and the member 72 urges the catch member downwardly. The lower end of the catch member 62 has an outwardly turned lip 78. In the embodiment shown, the lever 62 is connected to a plastics cover plate 79 on the underside of which the upper surface of the catch member 72 reciprocates, but preferably the cover plate 79 is formed integrally with the lever 62. In addition it will be noted that the upper leg 1 2 extends beyond the junction of "knee", at 81, with the lower leg 13. The pads 1 6 are located at the extreme lower ends of legs 1 2 in this case. In use, as with the previously described embodiments, the slider plate 34 is first slid downwardly from the upper storage position so that the upper and lower leg parts 1 2 and 1 3 on either side of the ladder are spread apart until each rubber pad 1 6 engages firmly on the ground. The lever member 62 is then pressed inwardly as shown in Figs. 11 and 12, and the upper dog 69 engages a tooth of the rack 32 and the levering action lifts the rack upwardly together with the ladder to which the rack is attached. The lifting action is illustrated in Fig. 15, where the movement of the levers 62 inwardly from the position shown in broken lines causes the foot of the ladder 1 8 to be lifted a small distance clear of the ground, so that the weight of the ladder is transferred to the outlying pads 1 6. The extent of upward lifting need not be large and typically may be about one-quarter of an inch. A satisfactory stabilization is achieved with this lifting action. As the lever 62 is pressed inwardly, the lower edge of the catch member 72 engages the rounded surface of the bridge 63 as shown in Fig. 1 3 and the catch member is pressed upwardly against the action of the spring 77 until the lever is pressed inwardly sufficiently for the lip 78 to clear the edge of the recess 64 in the bridge 63. The catch member 72 then snaps downward under the action of the spring 77. On release of the lever 62, the spring 41 between the lever 62, and the slider plate 34 presses the lever 62 outwards so that the lip 78 is held pressed into positive engagement with the recess 64, preventing outward movement of the lever 62. As shown in Figs. 1 3 and 14, at the inward position of the lever 62 the rack 32 is engaged by the second, lower dog 71 as well as by the upper dog 69, so that movement of the slider plate 34 relative to the rack 32 and track 61 is prevented. The weight of the ladder, and man is thus distributed between the two dogs 69 and 71, and two positions of the rack. If desired, more such dogs or teeth may be provided for still greater load distribution. Other forms of operating means such as gears may also be used in some cases. For example spur gears could be used to replace the dogs, or teeth, such gears meshing permanently with the racks. Operating levers could connect with the gears through rachet mechanisms. As a safeguard against accedental dislodgement of the lever 62, it will be noted that in order to free the lip 78 from the recess 64, it is necessary to simultaneously press the lever 62 inwards-and grasp the catch member 72 between the fingers and slide it upwardly relative to the lever 62. Thus with this arrangement, the catch cannot be freed by an accidental blow striking the mechanism. As stated above the lower leg part 1 3 is pivotally connected to the upper leg part 1 2 at a point 81 or knee intermediate the ends of the part 1 2. With this arrang'ement the lower leg part is spaced upward from the ground and so can remain clear of the ground surface if the leg 1 2 needs to be extended across a step, and the length of the track 61 can then be made much greater so as to permit a greater extension of legs 12, where needed. The foregoing is a descirption of a preferred embodiment of the invention which is given here by way of example only. The invention is not to be taken as limited to any of the specific features as described, but comprehends all such variations thereof as come within the scope of the appended claims. CLAIMS (13 Feb 1979)

1. Stabilizing means for connection on the outer side of the side pieces of a ladder comprising upper and lower leg parts connected together at a pivotal knee, the lower leg part connecting pivotally with a support member adapted to be secured on the side piece of the ladder, and the upper leg part

conhecting pivotally with a locking member sliding freely along the side piece of the ladder and being releasably retainable on the side piece at an upper storage position in which the leg parts lie flat along the side piece and a range of lower stabilizing positions wherein the leg parts mutually incline outwardly from the ladder and wherein the leg parts can be braced against an adjacent stable surface.

2. Stabilizing means according to claim 1 including a surface-engaging pad pivotally connected on the upper leg part for engaging said surface.

3. Stabilizing means as claimed in Claim 1 and 2 and including releasable retaining means for retaining the operating means in fixed position relative to the reaction member.

3. Stabilizing means as claimed in Claim 1 and 2 and including a reaction member mounted on the side piece of the ladder above the lower leg part, operating means pivotally connected to the upper leg part and moving in engagement with the reaction member to shift the reaction member upwardly relative to the operating means and upper leg part, and releasable retaining means for retaining the operating means in fixed position relative to the reaction member.

4. Stabilizing means according to claim 1 to 3 wherein said reaction means comprises a toothed rack adapted to be connected longitudinally on the side piece and the operating means comprise a pivotal dog for engagement with the rack, the dog reacting against the rack and urging the rack upwardly relative as the dog is pivoted inwardly with the rack, and wherein said releasable retaining means retain said dog in engagement with said tooth.

5. Stabilizing means according to claims 1 to 4 including a spring biasing the dog outwardly and wherein said releasable retaining means is operable to hold the operating means against the spring action in the inner position with the dog in engagement with the rack.

6. Stabilizing means according to claims 1 to 5 including a track for connection longitudinally on the side piece and a slider pivotally connected on the upper leg part and sliding on the track, and wherein said operating means are pivoted on the slider.

7. Stabilizing means according to claim 6 wherein the slider is slidingly confined by the track.

8. Stabilizing means according to claims 1 to 7 wherein the releasable retaining means comprise a catch member which is released by simultaneously lifting it and pushing it inwardly toward the side piece.

9. Stabilizing means according to claim 8 wherein the catch member pivots with the operating means and has a projecting lip engageable on a catch recess when the catch member is pivoted inwardly, and including a spring biasing the catch member downwardly toward the catch recess..

10. Stabilizing means according to claims 1 to 9 wherein the lower leg part is pivotally connected intermediate the ends of the upper leg part.

11. Stabilizing means according to claims 1 to 10 including spring means tending to urge the lower and upper leg parts upward.

1 2. Stabilizing means according to claim 11 wherein the spring means acts between the reaction member and the lower leg part.

1 3. Stabilizing means as claimed in Claims 3 to 12 wherein said operating means comprises at least two tooth members engageable in spaced apart relation in said rack.

14. Stabilizing means as claimed in Claim 3 including rotatable gear means connected to the upper leg part and rotating in engagement with the reaction member and lever means for operating said gear means to shift the reaction member upwardly relative to the axis of rotation and the upper leg part, and releasable retaining means for retaining the rotatable means in fixed position relative to the reaction member.

1 5. Stabilizing means for a ladder substantially as described with reference to the accompanying drawings.

CLAIMS (3 Jan 1980)

1. Stabilizing means for connection on the outer side of the side pieces of a ladder comprising upper and lower leg parts connected together at a pivotal knee, the lower leg part connecting pivotally with a support member adapted to be secured on the side piece of the ladder, and the upper leg part connecting pivotally with a slide member sliding freely along the side piece of the ladder, a reaction member mounted on the side piece of the ladder above the lower leg part, and operating means pivotally connected to the slide member and moving in engagement with the reaction member to shift the reaction member upwardly relative to the operating means and upper leg part whereby the slide member is releasably retainable on the side piece at an upper storage position in which the leg parts lie flat along the side piece and a range of lower stabilizing positions wherein the leg parts mutually incline outwardly from the ladder and wherein the leg parts can be braced against an adjacent stable surface.