GB2146688A - Ladder stabilizers - Google Patents

Abstract

A ladder stabilizer comprises an intermediate member (101, 102, 107, 108) clamped to a side member (103) of a ladder and mounting a leg (112) which extends sidewardly and rearwardly from the ladder. A respective leg (112) is provided on each side member (103). A pivot bracket (109) is slidable on spaced rails (107, 108) of the intermediate member and clampable thereon by a bolt (110) and lever (111). The leg (112) is pivoted to the bracket (109) by a pin (113) and a fitting (114) at the upper end of the leg (112) can be clamped to the intermediate member by a clamp nut (117) so that the leg (112) extends rigidly from the intermediate member. <IMAGE>

Description

SPECIFICATION Lader stabilizers The invention relates to ladders, and particularly to stabilizers for ladders.

Accidents with ladders are a relatively common occurrence and normally arise either due to the foot of the ladder sliding outwardly away from an upright surface against which the ladder is supported or by the feet of the ladder remaining relatively stationary, but the ladder pivoting about the feet and sliding sideways on the upright surface against which it was supported. Either of these occurrences can result in serious injury to a person who was at the top of the ladder at the time that the feet slipped or the ladder pivoted.

According to the invention a ladder stabilizer comprises a pair of legs each pivoted to a respective side member of the ladder at a spacing from the bottom end thereof and so disposed that in use they slope in an opposite way to the slope of the ladder with the bottom ends of the legs engaging the ground directly or through another member and with the bottom ends of the legs further apart than the top ends thereof and means to restrain the legs from pivoting further away from the ladder both forwardly and sidewardly.

The legs may each be pivotable to a respective one of the side members of the ladder by way of a respective intermediate member secured to the respective side member of the ladder. A respective pivot mounting for each leg may be slidable along the respective intermediate member in a direction longitudinally of the respective side member of the ladder to cause the bottom end of the leg to engage the ground, the pivot mounting being securable, for example by clamping means, against further sliding once a desired position is reached.

The pivot mounting for the leg may incorporate said means to restrain the legs.

Alternatively said means to restrain the legs may comprise a further pair of legs each pivoted to a respective side member of the ladder at a spacing from the position at which the respective leg of said pair of legs is pivoted to the respective side member of the ladder which each one of the legs of said pair of legs secured to a respective one of the legs of the further pair of legs.

The legs of each of said pair of legs of the ladder and said further pair of legs of the ladder when provided are preferably so coupled to the respective side member of the ladder that when the stabilizer is not in use the legs can be folded to a storage position to lie alongside and generally parallel to the respective side member of the ladder. Each of the legs may be coupled to the ladder by a pivot connection having its pivot axis at a fixed inclination so that as a leg is pivoted from the storage position generally parallel to the respective side member to an operative position it moves to the required position.

Alternatively the pivot connection may be a universal type pivot connection.

Flexible means such as cords or ropes or variable length rigid struts may be included in said means to restrain the legs to act as ties to secure the legs of said pair of legs at desired orientations to the ladder.

The invention is diagrammatically illustrated by way of example in the accompanying drawings in which: Figure 1 is a perspective view showing a ladder with a ladder stabilizer according to a first embodiment of the invention secured thereto; Figure 2 is a view showing means for securing a leg of the stabilizer of Fig. 1 to the ladder; Figure 3 shows a method of securing a stop member on a rope; Figure 4 is a perspective view showing a ladder with one half of a second embodiment of a ladder stabilizer according to the invention secured thereto; Figure 5 shows locking means of the embodiment of Fig. 4; Figures 6 and 7 are respectively a side view and an elevation of an alternative form of locking means to that shown in Fig. 5; Figure 8 shows to a greater scale part of the embodiment shown in Fig. 4; Figure 9 is a fragmentary end view of the embodiment of Fig. 8;; Figure 10 is a perspective view of a ladder with one half of a fourth embodiment of a ladder stabilizer according to the invention secured thereto; Figure 11 is a perspective view showing a ladder with one half of a fifth embodiment of a ladder stabilizer according to the invention secured thereto; Figure 12 is an exploded view of a part of the ladder stabilizer shown in Fig. 11; Figures 13, 14 and 15 show tie-off means for flexible ties.

Figure 16 shows a modification of the fifth embodiment of Figs. 11 and 12; Figures 17, 18 and 19 show respectively a side elevation and a rear elevation of a ladder stabilizer according to a sixth embodiment of the invention in the position and a side elevation when folded for storage; Figures 20 and 21 show alternative strut length fixing means to those shown in Figs.

17 to 19; Figures 22 to 24 show alternative means for fixing strut sleeves to legs to those shown in Figs. 1 7 to 19; Figures 25 and 26 are fragmentary perspective views showing a ladder stabilizer according to a seventh embodiment of the invention respectively in an operative position and in a folded for storage position; and Figure 27 shows another embodiment in a view similar to that of Fig. 25.

Referring to the drawings and firstly to Fig.

1, a ladder 1 comprises side members 2 and 3 and a plurality of rungs 4. The ladder shown is an aluminium ladder with tubular rungs 4 and plates 5 and 6 are secured to the side members 2 and 3 of the ladder by bolts 7 which extend through the bores of the tubular rungs 4 and co-operate with nuts provided outside similar plates 5 and 6 on the other side of the ladder. The plate 5, as shown in Fig. 2, has an outwardly turned bottom portion 5a through an aperture in which a bolt 8 is passed, the bolt 8 having a head secured in a cap 9 at the upper end of leg 10. Part spherical members 11 and 12 are provided on opposite sides of the member Sa, a spring 1 3 surrounds the bolt 8 and a nut 14 is provided on the upper end of the bolt 8.By means of the arrangement 8 to 14, the leg 10 is pivotally mounted on the plate 5 so as to be pivotable with respect thereto througha considerable angle. A further leg 1 5 is mounted on the side member 2 of the ladder in similar manner to the mounting of the leg 10 on the side member 3. The plate 6 has at its lower ends means 1 6 whereby a rope 1 7 can be securely tied off. The rope 1 7 passes from the means 1 6 on the plate 6 on the side member 3, through the bottom rung 4 of the ladder through an aperture in the leg 15, through an aperture in the leg 10, through the bottom rung 4 and is tied off on a plate 6 provided on the side member 2 at means 1 6 on the plate 6 on the side member 2.Means for forming an adjustable stop on the rope 1 7 are shown in Fig. 3 and comprise a tubular member 18 through which the rope 1 7 is passed, the rope after passing through the member 18 being taken back to the first end and passed through again at least once. If desired a rubber disc, shown at 19, can be provided on the end surface of the member 1 8 before the rope is looped therethrough to increase friction. It will be seen that with the rope 1 7 having no tension thereon the tubular member 18 can be moved longitudinally on the rope 1 7 but that as soon as tension is applied to the rope the member 18 will be locked in position.Fig. 1 shows that a pair of the members 18 can be provided on the rope 1 7 to prevent movement of the rope through the legs 10 and 15.

In use the ladder 1 can be leant against a wall (not shown) until it is in the desired orientation, the legs 10 and 1 5 can then be moved to a position such that their lower ends engage the ground and the lower ends are considerably wider apart than the spacing between the two plates 5a which determine the spacing apart of the upper ends of the legs 10 and 1 5. The members 18 can then be slid on the rope 1 7 to engage the legs 10 and 1 5 and the rope 1 7 can be tied off by the means 16 at the plates 6. It will be seen that any tendency for outward sliding movement of the foot of the ladder, that is to say in the direction of the arrow 20 will be checked by the engagement of the lower end of the legs 10 and 1 5 with the ground.Also sliding movement of the upper end of the ladder on the wall, that is to say in the direction indicated by the arrow 21 will be resisted by the legs since the bottom ends of the legs 10 and 1 5 are wide spread and sliding movement as indicated by the arrow 21 will attempt to force the legs 10, 1 5 into the ground. The ladder is thus stabilized.

When the ladder is not in use and is to be transported the rope 1 7 can be detached from the tie-off means 1 6 and the legs 10, 1 5 folded to lie alongside the side members 3 and 2 respectively.

In the embodiment of Fig. 4, a ladder 1 has side members 2 and 3 and rungs 4 as in the embodiment of Fig. 1. In this embodiment the two plates 5 and 6 are replaced by a single plate 25 secured by bolts 27 which pass through the rungs 4. Adjacent its lower end the plate 25 has a pair of lugs 28 through which passes a pivot pin 29, the pivot pin 29 also passing through a leg 30. A further leg 31 is pivoted to the leg 30 by a pin 32 and at its upper end is pivoted to a pair of lugs 33 by means of a pin 34. The pair of lugs 33 are mounted on a slide 35 and the slide 35 is mounted on a slide plate 36 in a manner such that it is longitudinally slidable but cannot be detached outwardly. The slide plate 36 has apertures 37 therein and the slide 35 has a spring loaded pin 38 engageable in the apertures 37.The axes of pivot defined by the pins 29 and 34 are such that, in the extended position of the stabilizer shown, a pad 40 carried by the outer end of the leg 30 can be engaged with the ground at a position spaced laterally from the respective side member 3 of the ladder and also forwardly, that is to say towards an upright surface (not shown) against which the ladder is supported. The pad 40 can be brought into firm engagement with the ground by pulling downwardly on a handle 41 provided on the slide 35 and then engaging the pin 38 of the slide in a suitably located one of the apertures 37 in the slide plate 36. When the ladder is not in use the pin 38 can be retracted, the slide 35 slid up the slide plate 36 and the pin engaged in a top end hole 37a so that the legs 31 and 32 lie closely adjacent the side member 3.

Two rows of staggered apertures 37 and two pins 38 may be provided if desired to permit finer adjustment. Alternatively a rack of louvre kind could be provided on the slide plate 36 to co-operate with a pawl provided on the slide 35.

Fig. 5 shows that the slide plate 36 is wedge shaped in section, the slide 35 has hook portions 35a at its sides which engage over projecting portions 36a of the plate 36, the pin 38 is spring loaded towards the slide plate 36 by a spring 42 and a lever 43 incorporating a cam 44 is provided pivoted to the outer end of the pin 38 by a pivot pin 45 such that moving the lever 43 through approximately 180' will allow the pin 38 to engage in one of the holes 37 in the plate 36 and pivoting the lever 43 to the position shown will retract the pin 38 from the slide plate 36 and allow the slide 35 to be moved longitudinally of the slid plate 36.

Figs. 6 and 7 show an alternative arrangement for a pin 38, the pin 38 in this case being mounted in a housing 46, biased by a spring 47 and movable by a lever 48 which is spring loaded at its lower end by springs 49.

By pulling on the plate 48 the pin 38 can be retracted into the housing 46.

The embodiment of Fig. 8 is very similar to that of Fig. 4, but in conjunction with Fig. 9 it can be seen that the side member 3 of the ladder comprises an I-section member having a web 3a and end flanges 3b each of which comprises a curved portion 3c and end beads 3d. A plate 50 corresponding to the plate 25 of the embodiment of Fig. 4 is bolted to the web 3a by bolts which extend through the rungs 4 and the slide 51 has a base plate 52 which is slidable over the plate 50 and is prevented from moving outwardly by the beads 3don the ladder flanges 3b. The pin 38 extends through the slide 51 and the slid plate 52 into apertures provided in the plate 50.

The embodiment of Fig. 10 is very similar to the embodiment of Figs. 4 and 8 but has two legs 54 and 55 corresponding generally to the legs 31 and 30 but pivoted by a pivot pin 56 provided immediately adjacent a foot pad 57.

In the embodiment of Figs. 11 and 12, a plate 60 is provided secured to the side member 3 of the ladder and mounts lugs 61 through which a pivot pin 62 passes thereby pivotably to mount a leg 63. The axis of the pin 62 is angled as in the embodiments of Figs. 4, 8 and 10 but instead of having a second leg, a rope 64 is tied to a lug 65 on the leg 63 and is tied off by tie-off means 66 at the bottom end of the plate 60. Thus the constraint of the lugs 61 and the pin 62 prevent the leg 63 from pivoting other than about the axis of the pin 62 and the rope 64 restrains the extent of pivoting of the leg 63 about the axis of the pin 62. At a position further up the side member 3 of the ladder a saddle 67 is provided to receive the leg 63 when it is folded to lie alongside the side member 3 after release of the rope 64 from the tie-off means 66.As best seen in Fig. 12 a spring 68 is provided on the plate 60 and the upper end of the leg 63 is shaped to form a cam 63a which co-operates with the spring 68 to retain the leg 63 in desired positions.

By replacing the rope 1 7, 64 with a chain 70, the tie-off means shown in Fig. 1 3 can be used, the chain 70 having a handle 71 whereby it can be pulled and co-operating with a slotted plate 72 and a bridging link 73, the slot 74 in the plate 72 securely retaining the chain in a position to which it is moved with respect to the plate 70. Fig. 14 shows that the rope 1 7 or 64 can be tied off by providing spacer tubes or beads on the rope alternating with washers 75 and a plate 76 with a slot 77 therein to co-operate with the washers to retain the rope in a position to which it is moved with respect to the plate 76.Fig. 1 5 shows that the rope 17, 64 can co-operate with a split cone member 78 and with a plate 79 having an aperture 80 therein of a size such that the cone member 78 cannot entirely be pulled through the aperture 18. The cone 78 can be slid along the rope to a desired position and the tension of the rope 1 7 will then jam it in the aperture 70 in the plate 79 to cause teeth 81 on the split cone member to grip the rope and prevent it moving with respect to the plate 79.

In the modification shown in Fig. 16, the rope 64 is replaced by a pivoted strut 82 having a sleeve 83 at its outer end encircling the leg 63a which is here provided with transverse apertures 63b in which pins 63c can be engaged to retain the sleeve 83 in a desired position. A foot 84 of the leg 63a can be screwed into or out of the leg 63a to adjust the length of the leg 63a.

Figs. 1 7 to 1 9 show an embodiment similar to Figs. 1 and 2 but with the rope 1 7 replaced by telescopic struts. Main legs 85, 86 have a similar top mounting to that of Fig.

2 but include transverse apertures 87 in which pins 88 can be inserted. The telescopic struts comprise side struts 89, 90 and a front strut 91. The struts 89, 90 are pivotally mounted to plates 92 by a sloppy pivot 93, are in two telescopic portions 89a, 89b and 90a, 90b, and at their forward ends mount a sleeve 89c, 90c by means of pins 89d, 90d, the sleeves encircling the respective leg 85, 86. In the erected position the struts 89, 90 bear against the respective side member 2, 3 of the ladder. Pins 88 are also insertable in the struts 89, 90 and 91 to set the length thereof. The front strut 91 is also in two telescopic parts 91 a, 91 b and has a sleeve 91 c at each end encircling the respective leg 85, 86. Feet 93 on the legs 85, 86 can be screwed in or out to adjust the leg length as in Fig. 16.

As can be seen in Fig. 19, the sleeves 90c and 91 c remain on the respective leg 85 in the storage position, the two halves 91 a and 91 b of the front strut 91 being separated.

As shown in Figs. 20 and 21, instead of a loose pin 88, the struts 89, 90, (as shown the strut 90) can have a pin 94 on a lever 95 which is pivoted on a pin 96 of a collar 97 and biassed by a torsion spring 98 for en gagement in the aligned apertures in the strut portions 90a, 90b.

To locate the strut sleeves 89c, 90con the legs 85, 86, (90cand 86 as shown in Figs.

22 to 24), the legs 85, 86 can be rotatable each about its longitudinal axis and projecting stud portions 99 can be provided on the legs, the stud portions 99 being able to pass through a space 100 (Fig. 23) between end portions of the sleeves 89c, 90e to move from below the sleeve 89c, 90cto above the sleeve and vice versa, rotation of the legs to move the stud portions 99 out of alignment with the spaces 100 locking the sleeves 89c, 90c against longitudinal movement on the legs 89, 90 in the manner of a bayonet fitting.

In the embodiment shown in Figs. 25 and 26, angle brackets 101 and 102 are secured to a side member 103 of a ladder by bolts 104, 105 which extend through tubular rings 106. The angle brackets 101 and 102, which are preferably aluminium castings, each have two projections (not shown) which can be press fitted into the bores of a pair of tubular members 107, 108 thereby securing the tubular members in parallel spaced relation to one another and to the side member 103 of the ladder. A pivot mounting 109 may be fabricated or cut from a standard box section and comprises a bracket having a base plate 109a, a pair of side lugs 109b, a connecting strap 109cjoining the side lugs 109b and a projecting key 109dfrom the base plate 109a to be received in the gap between the tubular members 107, 108.

A bolt 110 extends through an aperture inthe base plate 1 09a, and through the gap between the tubular members 107, 108 to co-opeate with a nut on a lever 111. The bracket 109 is thus slidable along the tubular members 107, 108 and can be clamped at any position by tightening the nut on the lever 111. A leg 11 2 is pivotably mounted to the bracket 109 by a pin 11 3 and has a bracket 114 at its upper end with an open ended slot 11 5 therein.When the leg 11 2 is pivoted outwardly away from the side member 103 to the position shown in Fig. 25, a key projection 11 4a (Fig. 26) engages in the gap between the tubular members 107, 108 and a further bolt 116, which also extends through the gap between the tubular members 107, 108, can be engaged in the slot 115 and a nut 11 7 tightened thereon to clamp the leg bracket 114 to the tubular members 107, 108.The clamping action of the bolt 11 6 and the bolt 11 7 removes the effect of any play at the pivot pin 11 3. The angle at which the leg 11 2 extends from the ladder is set by angling of the gap between the tubular members 107, 108 set by the projections (not shown) of the brackets 101, 102 and the angle which the portion of the bracket 114 having the slot 11 5 therein makes with the longitudinal axis of the leg 11 2. Thus a line joining the axes of the tubular members 107, 108 may extend at an angle of 45 to the side face of the side member 103. The bracket 114 is preferably also an aluminium casting with a projection (not shown) which extends into the upper end of the leg 112.

In the embodiment of Fig. 27, the angle brackets 101, 102 of Figs. 25 and 26 are replaced by a slide 1 20 which engages over the side member 1 21 of the ladder and is clampable to the side member by clamp screws 122. The slide has brackets 123, 124 which mount tubular members 125, 1 26 and in all other respects the embodiment of Fig.

27 is very similar to the embodiment of Figs.

25 and 26.

CLAIMS 1. A ladder stabilizer comprising a pair of legs each pivoted to a respective side member of the ladder at a spacing from the bottom end thereof and so disposed that in use they slope in an opposite way to the slope of the ladder with the bottom ends of the legs engaging the ground directly or through another member and with the bottom ends of the legs further apart than the top ends thereof and means to restrain the legs from pivoting further away from the ladder both forwardly and sidewardly.

2. A ladder stabilizer according to claim 1, in which the legs are each pivotable to a respective one of the side members of the ladder by way of a respective intermediate member secured to the respective side member of the ladder.

3. A ladder stabilizer according to claim 2, in which a respective pivot mounting for each leg is slidable along the respective intermediate member in a direction longitudinally of the respective side member of the ladder to cause the bottom end of the leg to engage the ground, the pivot mounting being secureable by clamping means against further sliding once a desired position is reached.

4. A ladder stabilizer according to claim 3, in which the pivot mounting for the leg incorporates said means to restrain the legs.

5. A ladder stabilizer according to any one of claims 2 to 4, in which the intermediate member comprises a pair of tubular members extending in spaced parallel relation with one another and parallel to the respective side member of the ladder.

6. A ladder stabilizer according to claim 5, in which each leg has a fitting at the upper end thereof, which fitting can be clamped to the tubular members forming the intermediate member to secure the leg such that it extends sidewardly and forwardly from the ladder and is substantially rigid with respect to the ladder.

7. A ladder stabilizer according to claim 1, in which said means to restrain the legs comprises a further pair of legs each pivoted to a respective side member of the ladder at a spacing from the positon at which the respective leg of said pair of legs is pivoted to the respective side member of the ladder with each one of the legs of said pair of legs secured to a respective one of the legs of the further pair of legs.

8. A ladder stabilizer according to claim 7, in which the legs of each of said pair of legs of the ladder and said further pair of legs of the ladder are so coupled to the respective side member of the ladder that when the stabilizer is not in use the legs can be folded to a storage position to lie alongside generally parallel to the respective side member of the ladder.

9. A ladder stabilizer according to claim 7 or claim 8, in which each of the legs is coupled to the ladder by a pivot connection having its pivot axis at a fixed inclination such that as the leg is pivoted from the storage position generally parallel to the respective side member of the ladder to an operative position it moves to the required position.

10. A ladder stabilizer according to claim 7 or claim 8, in which each of the legs is coupled to the ladder by a pivot connection of the universal type.

11. A ladder stabilizer according to any one of claims 7 to 10, in which flexible means such as cords or ropes or variable lengths of rigid struts are included in said means to restrain the legs to act as ties to secure the legs of said pair of legs at desired orientations to the ladder.

1 2. A ladder stabilizer substantially as hereinbefore described and illustrated with reference to the accompanying drawings.

Claims (10)

1. A ladder stabilizer comprising a pair of legs each pivoted to a respective side member of the ladder by way of a respective intermediate member secured to the respective side member of the ladder at a spacing from the bottom end thereof and so disposed that in use they slope in an opposite way to the slope of the ladder with the bottom ends of the legs engaging the ground directly or through another member and with the bottom ends of the legs further apart than the top ends thereof and means to restrain the legs from pivoting further away from the ladder both forwardly and sidewardly.

2. A ladder stabilizer according to claim 1, in which a respective pivot mounting for each leg is slidable along the respective intermediate member in a direction longitudinally of the respective side member of the ladder to cause the bottom end of the leg to engage the ground, the pivot mounting being secureable by clamping means against further sliding once a desired position is reached.

3. A ladder stabilizer according to claim 2, in which the pivot mounting for the leg incorporates said means to restrain the legs.

4. A ladder stabilizer according to any one of claims 1 to 3, in which the intermediate member comprises a pair of tubular members extending in spaced parallel relation with one another and parallel to the respective side member of the ladder.

5. A ladder stabilizer according to claim 4, in which each leg has a fitting at the upper end thereof, which fitting can be clamped to the tubular members forming the intermediate member to secure the leg such that it extends sidewardly and forwardly from the ladder and is substantially rigid with respect to the ladder.

6. A ladder stabilizer according to claim 1, in which said means to restrain the legs comprises a further pair of legs each pivoted to a respective side member of the ladder at a spacing from the position at which the respective leg of said pair of legs is pivoted to the respective side member of the ladder with each one of the legs of said pair of legs secured to a respective one of the legs of the further pair of legs.

7. A ladder stabilizer according to claim 6, in which the legs of each of said pair of legs of the ladder and said further pair of legs of the ladder are so coupled to the respective side member of the ladder that when the stabilizer is not in use the legs can be folded to a storage position to lie alongside generally parallel to the respective side member of the ladder.

8. A ladder stabilizer according to claim 6 or claim 7, in which each of the legs is coupled to the ladder by a pivot connection of the universal type.

9. A ladder stabilizer according to any one of claims 6 to 8, in which variable length rigid struts are included in said means to restrain the legs to act as ties to secure the legs of said pair of legs at desired orientations to the ladder.

10. A ladder stabilizer substantially as hereinbefore described and illustrated with reference to the accompanying drawings.