EP0047151A2 - Dispositif de dénivellation d'une échelle - Google Patents

Dispositif de dénivellation d'une échelle Download PDF

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Publication number
EP0047151A2
EP0047151A2 EP81303947A EP81303947A EP0047151A2 EP 0047151 A2 EP0047151 A2 EP 0047151A2 EP 81303947 A EP81303947 A EP 81303947A EP 81303947 A EP81303947 A EP 81303947A EP 0047151 A2 EP0047151 A2 EP 0047151A2
Authority
EP
European Patent Office
Prior art keywords
ladder
arcuate member
levelling device
support means
mounting elements
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP81303947A
Other languages
German (de)
English (en)
Other versions
EP0047151A3 (fr
Inventor
Patrick Yelverton Williams
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yelverton Holdings Pty Ltd
Original Assignee
Yelverton Holdings Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AU73922/81A external-priority patent/AU7392281A/en
Application filed by Yelverton Holdings Pty Ltd filed Critical Yelverton Holdings Pty Ltd
Publication of EP0047151A2 publication Critical patent/EP0047151A2/fr
Publication of EP0047151A3 publication Critical patent/EP0047151A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06C—LADDERS
    • E06C7/00—Component parts, supporting parts, or accessories
    • E06C7/42—Ladder feet; Supports therefor
    • E06C7/44—Means for mounting ladders on uneven ground

Definitions

  • the present invention relates to ladder levelling arrangements for the purpose of permitting a ladder to be easily positioned and safely supported on a variety of surfaces with the ladder remaining essentially upright (when the ladder is viewed from the front).
  • the ladder When a ladder is to be placed against a structure such as a building, the ladder can be safe and stable providing the supporting ground is hard and substantially horizontal. However, particularly when long extension ladders are used, it is a common practice for a second person to stand on the bottom of the ladder so as to provide stability resisting any tendency for the feet of the ladder to slip or the ladder itself to tip sideways.
  • a ladder is subjected to considerable vibration and some degree of shock loading when a heavy man climbs to the top of the ladder and it is very important that the ladder does not move or slip during movement of the man.
  • a major problem arises where the ground beneath the ladder is sloping sideways since a conventional ladder can only be used in such circumstances if suitable packing is inserted under one leg so as to keep the ladder upright.
  • suitable packing may be employed, or that the packing may not be accurately and safely positioned, or alternatively that the packing may be not of quite the right dimension so that the ladder has a slight degree of lean which may not be noticed but prove to be unsafe when a man has climbed the ladder and is doing a job such as painting.
  • an adjustable foot which can be moved up or down and clamped in a desired position.
  • a levelling device comprises a foot which is mounted by screw-threaded engagement so that rotation of the foot permits adjustment of its height.
  • this form of adjustment is tedious and slow; these factors raise a substantial risk that a workman may not give sufficient attention to ensuring that the ladder is accurately positioned before commencing to climb the ladder.
  • the workman must bend down to make the adjustment and this is a tiring task which may induce dizziness when the workman stands up straight. This dizziness may cause misjudgement as to whether the ladder is truely upright.
  • a ladder levelling device comprising
  • the mounting elements are in the form of saddle-like elements arranged to extend around the arcuate member and to be fixed to the ladder.
  • Other forms of mounting element could be used, for example eye bolts, but saddles are the preferred form of mounting element and are preferably of spring steel.
  • the present invention may be provided in various embodiments and in one convenient embodiment the device can be prepared with instructions and if desired a template to facilitate fitting of the device to an existing conventional ladder.
  • the device could be embodied in a ladder as original equipment in which case the mounting elements could be integral with the ladder structure itself.
  • the four spaced mounting elements are arranged in a square array with two vertically spaced fixing points on each rail of the ladder, the lower and upper fixing points being at the same height on the respective rails.
  • the arcuate member is preferably formed as a substantially circular hoop of rigid construction and most preferably in the interests of a lightweight stable structure the support means is best formed from a metal framework fixed to the arcuate member at suitable locations between the mounting elements.
  • the surface of the arcuate member should be smooth for best performance and corresponding surfaces of the mounting elements should be similarly smooth.
  • the degree of relative movement in both directions of the arcuate member is limited by virtue of at least one of the connection points between the support means and the arcuate member being such that when this point is moved adjacent one of the mounting elements, the connection acts as a limit stop.
  • the mounting elements are in the form of saddles having an essentially closed loop surrounding the arcuate member, which preferably is of circular cross-section, each of the saddles being adapted to be bolted to a rail of the ladder.
  • the arcuate member is a closed circular ring and that the support means is in essence of a generally W-shaped form which (considering the central position of the ring for horizontal ground) is welded to the ring at diametrically opposite sides halfway up the ring and the centre leg of the W is welded at the middle, bottom portion of the ring.
  • the support means is in essence of a generally W-shaped form which (considering the central position of the ring for horizontal ground) is welded to the ring at diametrically opposite sides halfway up the ring and the centre leg of the W is welded at the middle, bottom portion of the ring.
  • four mounting elements are used and thus when the ladder is on horizontal ground the attachment points of the support means to the ring are located approximately mid-way between adjacent mounting elements.
  • the support means and arcuate member can readily be made from mild steel with spring steel being used for the saddles.
  • the ground engaging portion of the support means may be provided with suitable feet which preferably are of sufficient surface area to spread the load of the ladder.
  • the feet are preferably pivotal relatively to the main part of the support means to permit the ladder to be supported at different angles to the vertical direction. This is best achieved by fitting a leg with a fixed ball-shaped tip located at each side of the support means, and snap fitting a moulded foot with a part-spherical cavity onto the tip.
  • embodiments of the invention can work very effectively and easily.
  • the user simply places the support means of the ladder levelling device on the ground at the desired location and swings the ladder pivotally. Indeed the user does not even have to support the effective weight of the ladder to do this.
  • the weight of the ladder is sufficient to provide enough frictional force so that the ladder will not normally move any further and as soon as a person climbs on the ladder, the extra weight substantially increases the jamming tendency between the mounting elements and the arcuate member. Since the general plane of the arcuate member tends to move to be at a slight angle to the general plane of the ladder when a person steps on the ladder, movement of the ladder is prevented.
  • a clamping device could be incorporated to secure more positively the arcuate member relative to the ladder.
  • the most preferred form of this device is an over-centre clamping lock operable on an engagement member which has a sliding fit over the arcuate member such that when the lock is operated the arcuate member is pulled upwardly adjacent to one of the mounting elements, thereby positively taking up clearance between the arcuate member and the mounting element and, by virtue of frictional forces imposed by the locking element, tending to clamp the arcuate member against any movement.
  • a suitable high friction engagement pad at the top end of the ladder; this pad may be formed from resiliently compressible deformable rubber which has a high co-efficient of friction with other surfaces.
  • a ladder comprises side rails 2 and rungs 3 and although in the drawing only a short ladder is illustrated, the invention is equally applicable to extension ladders which may be made of various materials including aluminium and wood.
  • a levelling device 4 is connected to the bottom portion of the ladder and comprises a rigid circular ring 5, four saddles 6 and a rigid W-shaped support frame 7 which is fixed to the ring, conveniently by welding, at the mid-point of each side of the ring and at the bottom of the ring when the device is viewed on horizontal ground.
  • the bottom portion of the W-shaped frame is bent to form a pair of legs 8.
  • the legs 8 terminate in feet 9, one of which is shown in detail in Figure 3, and comprise a steel ball 10 screw-theadably secured on the associated leg 8 and snap-fitted into a moulded plastic foot pad 11 having a high friction facing 12.
  • feet 9 a firm and secure support for the ladder can be provided on a wide variety of ground surfaces including relatively steep slopes and steps.
  • the foot 9 swivels to accommodate the desired degree of lean of the ladder towards a building.
  • the saddles 6 which are secured by screws 13 to the ladder rails, and the ring 5 have smooth surfaces so that the ring can slide smoothly through the saddles.
  • the positioning of the saddles in a square array permits a wide range of movement of the ladder relative to the ring.
  • the spacing of the saddles 6 and the shape and size of the support frame 7 are chosen such that the following operational requirements can be achieved:
  • pivotal abutment pads 14 are utilised at each side of the ladder whereby firm non- slipping engagement of the top of the ladder with a structure such as a building can be provided.
  • the facing of this foot can be of a non-marking rubber such as white rubber.
  • the clamp comprises an over-centre lock 15 having a pivotal lever 16, a mounting bracket 17 secured to the rail 2 by a bolt 18, and a pivotal linkage 19 having a closed eye 20 at one end through which the ring 5 passes and an attachment leg 21 pivotably mounted on the lever 16 to engage the clamp, the lever 16 is displaced essentially upwardly and retained in the displaced position when it moves "over-centre".
  • the ring 5 is pulled upwardly so that hard engagement is established (a) between the ring 5 and the upper portion of the saddle 6 and (b) between the ring 5 and the lower portion of the closed eye on the linkage 18.
  • Levelling devices embodying the invention thus permit essentially automatic levelling of the ladder in a speedy and reliable manner, the construction being simple and therefore resistant to defects and failures after a period of service and/or abuse. Furthermore, the device can be made without exacting manufacturing requirements by simple techniques such as welding of very cheap materials such as mild steel tube. Essentially there are no wearing parts and since a relatively loose fit only is required between the saddles and the ring, no trouble should be experienced even if the levelling device is used in dirty conditions which may include spilt paint, mortar or other contaminants.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Ladders (AREA)
EP81303947A 1980-08-29 1981-08-28 Dispositif de dénivellation d'une échelle Withdrawn EP0047151A3 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
AU531580 1980-08-29
AU73922/81A AU7392281A (en) 1980-08-29 1980-08-29 Ladder levelling arrangement
AU5315/80 1980-08-29

Publications (2)

Publication Number Publication Date
EP0047151A2 true EP0047151A2 (fr) 1982-03-10
EP0047151A3 EP0047151A3 (fr) 1982-09-22

Family

ID=25611212

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81303947A Withdrawn EP0047151A3 (fr) 1980-08-29 1981-08-28 Dispositif de dénivellation d'une échelle

Country Status (1)

Country Link
EP (1) EP0047151A3 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991014850A1 (fr) * 1990-03-20 1991-10-03 Keith Edward Wright Dispositif de support pour echelles
WO2008151356A1 (fr) * 2007-06-15 2008-12-18 Ronald Paul Jones Dispositif de support réglable
US9534443B1 (en) 2011-12-27 2017-01-03 Robert C. Bogart Ladder and related methods

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2960182A (en) * 1958-05-12 1960-11-15 Elmer L Swanson Ladder supporting device
US3199629A (en) * 1963-11-12 1965-08-10 Robert W Fagaly Ladder construction
US3887034A (en) * 1973-12-26 1975-06-03 Raymond Lee Organization Inc Portable pipe clamp
CH563521A5 (en) * 1972-11-16 1975-06-30 Charley W Boyden Stabilising ladder support for uneven ground - has curved legs movable in arc on bottom rungs and lockable by toothed mechanism

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2960182A (en) * 1958-05-12 1960-11-15 Elmer L Swanson Ladder supporting device
US3199629A (en) * 1963-11-12 1965-08-10 Robert W Fagaly Ladder construction
CH563521A5 (en) * 1972-11-16 1975-06-30 Charley W Boyden Stabilising ladder support for uneven ground - has curved legs movable in arc on bottom rungs and lockable by toothed mechanism
US3887034A (en) * 1973-12-26 1975-06-03 Raymond Lee Organization Inc Portable pipe clamp

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991014850A1 (fr) * 1990-03-20 1991-10-03 Keith Edward Wright Dispositif de support pour echelles
WO2008151356A1 (fr) * 2007-06-15 2008-12-18 Ronald Paul Jones Dispositif de support réglable
US8162273B2 (en) 2007-06-15 2012-04-24 Ronald Paul Jones Adjustable support structure
US9534443B1 (en) 2011-12-27 2017-01-03 Robert C. Bogart Ladder and related methods

Also Published As

Publication number Publication date
EP0047151A3 (fr) 1982-09-22

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LU NL SE

PUAL Search report despatched

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18D Application deemed to be withdrawn

Effective date: 19830829

RIN1 Information on inventor provided before grant (corrected)

Inventor name: WILLIAMS, PATRICK YELVERTON