GB2592025A

GB2592025A - Ladder leveller

Info

Publication number: GB2592025A
Application number: GB2001901.4A
Authority: GB
Inventors: Sharples Richard
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-02-12
Filing date: 2020-02-12
Publication date: 2021-08-18
Also published as: GB202001901D0

Abstract

A levelling device for a ladder comprises a telescopic leg having a nested outer and inner tubes 1, 2 that are connected to a side rail of a ladder. The inner tube moves relative to the outer tube via a long-threaded screw 13. The screw passes through the end cap 25 of the outer tube and the threaded section 12 at the closed end of the inner tube, wherein the screw is rotated by a handle/capstan 32, 33 at the end of the screw positioned outside at the top of the telescopic leg. Rotating the handle in either direction causes the screw to rotate and either lower or raise the inner tube. During use the screw remains within the outer and inner tubes. The handle may be rotated by a drill bit that engages with the handle. Preferably the leveller is mounted to the side rail via brackets 16,17 and U bolts, wherein one bracket is shaped to clear the swaged ladder rung. The ground engaging end of the inner tube may have a pivotal ball mounted non slip foot (5, fig 2). The leveller may have a spirit level 18, and made from aluminium, stainless steel and brass.

Description

DESCRIPTION. 1

INFINITELY ADJUSTABLE LADDER LEVELLING DEVICE.

The present invention refers to an infinitely adjustable ladder levelling device which when clamped to either leg, left or right, of an existing unmodified ladder, see FIG1. Will enable the ladder to extend an inner-tube member, so that it is able to make contact with, a lower sloping, uneven surface or step.

The invention is inherently safe due to its fail safe design ie. Once the levelling adjustment has been carried out by turning the capstan assembly items 32, 33, clockwise or anti clockwise, as required, the operation is complete since there are no pins, pegs, or screws to be tightened or levers to activate before use. This eliminates any accidents due to forgetfulness. Spirit levels are provided, items 18. for left & right applications to speed up the levelling process.

The invention consists of an outer & inner rectangular square tubes items 1 & 2 (material aluminium), see FIG. 1,2 & 3.The inner-tube item 2, Is able to slide inside the outer-tube item 1, due to its lesser cross section, the two tubes are kept coaxially apart by rubbing strips items 7 & 8, see FIG.4 & Items 9 & 10 ( material tufnol) at two separate vertical locations as shown in FIG.1.

The lower end of item 2, inner -tube, is closed off with item 3,(material aluminium) being securely attached to item 2, with rivets item 6,see FIGS. 1 & 2.

Screwed into a matching threaded hole in the lower surface is item 5,flexible ball mounted anti slip rubber foot, locked in place with item 4, nut ( material stainless steel) At the upper end of item2, inner-tube,is closed off with item 11, (material stainless steel) , which is securely fixed to item 2, with items 14, rivets.

Item 13 is a long adjustment screw, ( material stainless steel)which passes through a matching threaded hole in item 12, large threaded nut, ( material stainless steel)-fixed in place by swaging in item 11, this prevents rotation. See FIG. 8, Item 13 can be made to rotate in item 12, thus effecting vertical adjustment to inner tube item 2.

At the lower end of the long adjustment screw, see FIG. 9 is a stop washer, item 35 ( material stainless steel) locked in place with locking screw item 36 ( material stainless steel), just above this feature is a rubber o ring item 34,which cushions the stopping action when reaching end of thread.

Rubbing strips items 7 & 8 are securely fixed to the inner faces of item 1,having chamfers uppermost, see FIG. 4, with rivets & bonding epoxy, items 38.A further set of rubbing strips are located & fixed at the upper end of the inner -tube item 2, securely fixed to the outer surfaces with rivets & bonding epoxy, items 14,as shown in FIGS. 1 & 8. These rubbing strips co-axially align the inner & outer tubes thus allowing the inner-tube to slide smoothly inside the outer tube, item 1.

At the top of the outer tube item 1, the tube is closed off with item 25 ( material stainless steel),

DESCRIPTION CONTINUED 2

which is securely fixed to item 1, outer tube, with counter sunk head screws, items 26, ( material stainless steel) FIG. S. The long adjustment screw item 13,has a reduced end diameter which passes through a matching hole in item 25,with thick washer Item 27,(material stainless steel) & item 28,thrust bush ( material brass)&capstan assembly items, 32 & 33, ( material stainless steel) ,having a matching square holes with item 13, The said assembly is held in place with item 30, socket head screw, ( material stainless steel), roll pins item,31 are fitted at 3 positions as shown in FIGS. 5 & 6, these items prevent the assembly from coming loose. As before rubber o ring, item 34, is set in place to cushion the inner tube assembly, when reaching end of travel, the long adjustment screw, item 13,can be operated either manually by rotating the 3 armed capstan to lower or raise the inner projecting tube, support leg, item 2,or by rotating by a battery drill fitted with the captive ball ended hexagon bit, item,19 & 204 materials stainless steel & brass respectively).

Returning to the lower outer tube portion item 1, ZED shaped brackets, items 15 & 16,( material aluminium) FIGS. 1 & 3,are securely fixed to item, I,as shown, one above the other. Threaded U bolts, items 22,( material aluminium), are fitted around the legs of the ladder as shown & passed through matching holes in the ZED shaped bracket items, 15 & 16, with the lower U bolt contacting the underside of the ladder rung, FIG 1, this positions the Ladder Leveller assembly vertically.Nuts & washers items 23 & 24,are fitted & tightened, ( material stainless steel).

This completes the Description.

Claims

CLAIMS. 1.An infinitely adjustable ladder levelling device, which when attached to either leg, left or right, of an existing unmodified ladder, will enable ladder to operate safely on uneven, sloping or stepped surfaces in a safe manner. 2.A device as claimed in 1.having an extendable inner tube, support leg, fitted with a flexible ball mounted anti slip rubber foot,allowing said foot to adjust, matching the angularity of the contacting surfaces. 2a.Prior Art,( US 4209078 A)depicts a pivoted foot item 50, for making contact with uneven, sloping surfaces, which are not conducive with stable safe requirements.( line contact) . 3.A device as claimed in 2.having clamping brackets, one above the other, firmly attached to the outer tube, the lower bracket has a cut out to clear the swaged ladder rung fixing feature. 3a.
Prior Art, ( US 4209078 A) shows no such feature making an unstable clamping surface. 4.
A device as claimed in 3, 2 U bolts passing around ladder leg then through matching holes in the clamping brackets, lower U bolt making contact with bottom ladder rung, thus positioning the assembly vertically, U bolts fitted with matching nuts, washers & finally tightened. 4a
Prior Art ( US 4209078 A) illustrates an unnecessary complicated leg clamping method making device heavy, complex & expensive to produce. 5.
A device as claimed in 4,having the vertical adjustment screw passing through an upper closure block, above which is a 3 armed capstan, securely fixed to a long adjustment screw able to be rotated in either direction,anti-clockwise rotation imparts a lowering of the inner tube, support leg, until contacting support surface.
6. A device as claimed in 5, during the lowering, or raising of the inner tube, support leg, the adjustment means, capstan, remains in the original vertical position as per artwork, thus the vertical adjustment screw remains protected & captivated within the inner & outer tubes at all times.CLAIMS CONTINUED. 6a,Prior Art ( US 4209078}illustrates & describes, a threaded rod passing through the top portion of said sleeve integral with hand wheel adjuster & having a stop at it's lower end abutting the top of the extension,this allows the hand wheel & threaded rod to rise from the sleeve until it screws out of the sleeve entirely leaving it vulnerable to damage & contamination.
7.A device claimed in 6,the vertical adjustment screw is within the inner & outer tubes at all times & is captivated at all times. 7a,Prior Art ( US 4209078)as stated in 6a,the threaded rod just prior to total disengagement is found to be poking out of the sleeve unsupported & unprotected from physical damage plus in the event of disengagement) the device becomes unsafe due to lack of captivation of main screw. 7b,

Prior Art ( US 4209078) a device as claimed in 6a, threaded rod having a stop at it's lower end is unworkable, since the threaded rod can only be screwed in from above passing through the threaded block, this means the stop would have to be larger than minor thread diameter for it to function, the stop would have to fitted from beneath which is unworkable.

8,A device claimed in 7,the inner tube) support leg is is captivated at all times during vertical adjustment, thus making it safe to operate. 8 a,Prior Art (US 4209078) illustrates & describes the, extension vertically adjustable, is shown solid in the artwork,with the end stop shown uppermost the only time that the threaded rod makes contact with the end stop is when there is an upwards force produced by the foot making surface contact, when this upwards force is removed there is nothing to stop the solid extension from falling from the bottom of sleeve member, with some consequence.

9,A device as claimed in 8,ladders are manufactured to be strong but light for obvious reasons, plus the materials used need to be rustproof for functionality & longevity, materials aluminium, stainless steel & brass have been chosen to fulfil this requirement for this invention application. 9 a,Prior Art ( US 4209078), no mention of construction materials have been declared,the sleeve, extension & threaded rod are mostly solid making the device very heavy, the sleeve as shown,would be impracticable & very expensive to produce.