Classifications

• • E—FIXED CONSTRUCTIONS
  • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
  • E06C—LADDERS
  • E06C1/00—Ladders in general
  • E06C1/02—Ladders in general with rigid longitudinal member or members
  • E06C1/32—Ladders with a strut which is formed as a ladder and can be secured in line with the ladder
• • E—FIXED CONSTRUCTIONS
  • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
  • E06C—LADDERS
  • E06C1/00—Ladders in general
  • E06C1/02—Ladders in general with rigid longitudinal member or members
  • E06C1/14—Ladders capable of standing by themselves
  • E06C1/16—Ladders capable of standing by themselves with hinged struts which rest on the ground
  • E06C1/20—Ladders capable of standing by themselves with hinged struts which rest on the ground with supporting struts formed as poles
  • E06C1/22—Ladders capable of standing by themselves with hinged struts which rest on the ground with supporting struts formed as poles with extensible, e.g. telescopic, ladder parts or struts
• • 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 a self supporting step- ladder that comprises a step portion, a supporting portion having an adjustable length, a hinge device and means to lock the angle between the step portion and the supporting portion during active position of said ladder, the hinge device being provided between the step portion and the supporting portion in order to pivotally connect said portions with each other.
• a problem in connection with self supporting step- ladders of the type defined above is that they are not adapted to be used in stairs since in such a position of use the supporting portion, having an adjustable length, must be made as short as possible.
• the supporting portion has a maximum length, there must be a certain overlap between the mutually, preferably telescopically, displaceable portions in order to give the supporting portion a sufficient stability when said portion has its maximum length. It is realised that such circumstances cause a restriction as regards the shortening of the length of the supporting portion.
• a primary object of the present invention is to define a self supporting step-ladder of the type defined above, said step ladder being especially suitable to be used in stairs.
• a further object of the ladder according to the present invention is that it should have a proper stability and fulfil pending security regulations.
• an object of the ladder according to the present invention is that according to a preferred embodiment it should be extremely compact in its transporting position.
• Figure 1 shows a side view of a self supporting step-ladder according to the present invention, said step-ladder being m a position of use on a horizontal base surface, the step portion and the supporting portion of the step-ladder having maximum length;
• Figure 2 shows in the same scale a corresponding side view as figure 1, however, the step portion and the supporting portion of the step-ladder having minimal length;
• Figure 3 shows in a larger scale the step-ladder m collapsed transporting position;
• Figure 4 shows a section along A-A in figure 2, the section extending through only one side element of the step- ladder;
• Figure 5 shows in the same scale as figure 1 the self supporting step-ladder m a position of use in a flight on stairs;
• Figure 6 shows m a larger scale a detail of the attachment between the step portion and the supporting portion;
• Figure 7 shows a side view of an alternative embodiment of a step-la
• the self supporting step-ladder comprises a step portion 1 and a supporting portion 3, said portions resting on a horizontal base surface 4.
• each of said portions 1, 3 comprises two mutually displaceable elements .
• the step portion 1 comprises a first step portion element 5 and a second step portion element 7, said elements 5, 7 being displaceable relative to each other m the longitudinal direction of the elements 5 and 7.
• the first step portion element 5 comprises two first side pieces 6 and the second step portion element 7 comprises two second side pieces 8, a number of steps (not visible) extending between each pair of side pieces 6 and 8 respectively. Since the step- ladder according to the invention is shown m side view only, only one side piece 6, 8 of the respective step portion element 5, 7 is visible. The more detailed design of the cross section profile of the first and second side pieces 6, 8, and their mutual cooperation, will be described more m detail below, see especially figure 4.
• the first side pieces 6 of the first step portion element 5 is provided with supporting means 9 that rest upon the horizontal base surface 4.
• Said supporting means 9 are hingedly connected to the first side pieces 6 and are also adjustable m height in the shown position of use.
• a knee support 10 is attached, the legs 11 of the knee support 10 being received in the second side pieces 8 of the second step portion element 7.
• the ladder according to the present invention has first means (not shown) to lock the knee support 10 in desired position, a varying length of the legs 11 being received m the side pieces 8 in dependence of how far the knee support 10 projects above the upper end of the second step portion element 7.
• Said first locking means may for instance constitute locking screws .
• the supporting portion 3 comprises two supporting legs of adjustable length, each of said supporting legs comprising a first tubular supporting leg portion 12 and a second tubular supporting leg portion 13, said leg portions 12, 13 being displaceable m their longitudinal direction relative to each other.
• the first supporting leg portion 12 may be received telescopically in the second supporting leg portion 13.
• the supporting portion 3 comprises second means 14 in order to mutually lock the first supporting leg portion 12 and the second supporting leg portion 13 relative to each other m a certain position.
• said second locking means 14 being designed m such a way that locking of the portions 12 and 13 may be effected in a stepless, arbitrary position.
• Transverse bars (not shown) may be provided between the supporting legs m order to increase the stability and torsional rigidity of the supporting portion 3.
• said cross sectional shape of the tubular and supporting leg portions 12, 13 said cross sectional shape may in principle be arbitrary, however the cross sectional shape of the telescopically cooperating supporting leg portions should of course coincide .
• the step portion 1 and the supporting portion 3 are mutually connected by means of a hinge device 15 that constitutes an important part of the present invention.
• Said hinge device 15 will be described more in detail below, reference being made especially to figures 5 and 6.
• the basic function of said hinge device 15 is to have the step portion 1 and the supporting portion 3 pivotally connected to each other, in the disclosed embodiment said hinge device 15 being provided in the area of the upper ends of the step portion 1 and the supporting portion 3 when said portions are in the position of use.
• the self supporting step-ladder according to the present invention is also equipped with a means 16 for locking the angle between the step portion 1 and the supporting portion 3 m the position of use of said ladder, a conventional technical term for said means is apart sliding safety device.
• the apart sliding safety device 16 is structurally an articulated arm having two mutually hinged subarms 17 and 18 that also are hingedly connected to the step portion 1 and the supporting portion 3 respectively.
• both the step portion 1 and the supporting portion 3 have their maximum length.
• both the step portion 1 and the supporting portion 3 have their minimum length.
• the maximum length of the supporting portion 3 is 1,5-1,75 times the minimum length of the supporting portion 3.
• the transfer of the supporting portion 3 from the position shown m figure 2 to the position shown in figure 1 brings about a prolongation of the supporting portion with 50%-75%.
• the corresponding reasoning is m principle valid also for the step portion 1.
• Both m the position of use according to figure 1 and the position of use according to figure 2 the articulated arm 16 is parallel to the base surface 4.
• the step portion 1 forms an angle to the horizontal base surface 4 of 70° while the supporting portion 3 forms an angle of 69° to the horizontal base surface 4. Both these angle values are within the pending security regulations.
• the side pieces 6, 8 constitute extruded aluminium profiles.
• the position of use in a flight of stairs of a ladder according to the present invention is shown in figure 5.
• the hinge device 15 has assumed a position where it is displaced upwardly relative to the step portion 1, reference being made to figure 6 in order to explain the transfer of the hinge device 15 and describe its structural design more in detail.
• the transfer of the hinge device 15 to an upper position has the consequence that the change of length of the supporting portion 3 does not need to be equal large as if said transfer possibility was not present. Indirectly, this has an effect on the stability of the supporting portion 3, and in this connection reference is being made to what has been said above concerning the prolongation of the supporting portion 3.
• Due to the presence of the transferable hinge device 15 the maximum length of the supporting portion 3 has been restricted to 1,75 times the minimum length of the supporting portion 3. Such a restriction makes it possible to achieve an acceptable stability of the ladder.
• the hinge device 15 comprises two links 21 having a certain length, only one of the links being visible m figure 6.
• the links 21 have one end pivotally connected to the adherent second side piece 8 of the second step portion element 7 and the other end pivotally connected to an adherent second supporting leg portion 13 of the supporting portion 3 in the point 23.
• a transverse bar (not visible) is provided that connects the attachment of the links 21 to the respective second supporting leg portion 13.
• the hinge device 15 may assume two separate positions of use.
• the lower position of use see also figures 1 and 2 is used when the ladder according to the present invention is located on a horizontal base surface 4.
• the upper position of use see also figure 5, is used when the ladder according to the present invention is located m a flight of stairs.
• the links 21 are brought to pivot around its attachment to the second side piece 8, this being indicated by means of the arrows 24 and 25 m figure 6 and the dotted position of the visible link 21.
• the arrows 24 mean that the hinge device 15 is transferred from its lower to its upper position of use while the arrows 25 mean that the hinge device 15 is transferred from its upper to its lower position of use.
• the user of the ladder grabs the transverse bar between the attachment of the links 21 to the respective second supporting leg portion 13. Pivoting of this transverse bar also induces pivoting of the links 21 around their attachment to the respective second side piece 8 in the way that is shown m figure 6.
• each of the second step portion elements 7 are provided with a recess 26 in the edge that faces towards the supporting portion 3, said recess 26 being intended to receive the transverse bar when the hinge device 15 is located m its lower position of use, see figures 1 and 2.
• a snap lock or the like may be provided m connection with said recesses 26 m order to detachably retain the hinge device 15 in its lower position of use. From security reasons this does not seem to be necessary since the force that acts in the second supporting leg portions 13 in said position of use strives to displace the hinge device 15 to abutment of the second step portion element 7.
• the step portion forms an angle to the horizontal plane of 70° while the supporting portion 3 forms an angle to the horizontal plane of 80°. These angles are the largest acceptable according to the pending security regulations.
• the articulated arm 16 assumes a position where it forms a certain angle to the horizontal plane.
• the alternative embodiment shown m figures 7 and 8 of a step-ladder according to the present invention differs principally from the embodiment described above through the design of the supporting portion 3 ' and the hinge device 15 ' .
• the supporting portion 3 ' is in principle designed as a step portion, which means that both the actual step portion 1 ' and the supporting portion 3' are provided with steps, upon which the user may stand.
• the hinge device 15' is shown in its uppermost position.
• the hinge device 15' comprises two bars 21', one for each side piece 8', said bars 21' being telescopically received in the adherent side piece 8' .
• the free end of the bar 21' is attached to the supporting portion 3 ' via an articulated attachment point 23' .
• the bar 21' is pulled out to a maximum of the adherent side piece 8 ' , said hinge device 15 ' also comprising means to lock the bar 21' relative to the side piece 8' in an extended position.
• the bar 21' may also be completely pushed into the side piece 8 ' .
• one portion 12 ' of the supporting portion 3 ' has been displaced upwards in order to form a knee support for the user that stands on the step portion 1'.
• the lower end of the second portion 13 ' of the supporting portion 3 ' will rest against a step of the flight of stairs that the ladder is positioned in.
• said one portion is displaced downwards, in order to prolong the supporting portion 3 ' , when the ladder according to the present invention is resting on a horizontal base surface, this of course under the prerequisite that the step portion 1' is prolonged to a corresponding degree.
• the bar 21' of the hinge device 15' is pulled out in figure 8 to a somewhat lesser degree that in figure 7.
• the bar 21' may be locked relative to the side piece 8 ' in a number of predetermined positions, said locking may for instance be effected by means of a pin (not shown) that penetrates both the bar 21' and the side piece 8' .
• the step portion 1; 1' and the supporting portion 3; 3' form with the base surface at different positions of use of the step-ladder according to the present invention.
• the step portion 1; 1' forms an angle to the base surface of 69° or 70° while the supporting portion 3 ; 3' forms an angle of 69°, 70°, 72° or 80° to the base surface.
• the angle that the step portion 1; 1' forms with the base surface is in the interval 60-70° while the angle that the supporting portion 3 ; 3 ' forms with the base surface is in the interval 65-80°.
• the side pieces 6; 6' and 8; 8' preferably are made out of aluminium.
• the rest of the ladder may in principle be manufactured from aluminium although certain details may be manufactured from other materials, e.g. plastic .
• the self supporting step-ladder comprises a step portion and a supporting portion, which are mutually connected by means of a hinge device.
• the supporting portion is designed as a step portion, i.e. that the ladder according to the present invention comprises two step portions that are mutually connected by means of a hinge device, that according to the principle of the present invention is transferable between at least two positions of use along the longitudinal direction of the first step portion.
• the second step portion i.e. the supporting portion that is equipped with steps, is in a usual way adjustable as regards its length.
• the hinge device constitutes a link mechanism that is pivoted between its two positions of use or a bar 21' that is displaceable in its longitudinal direction relative to the step portion 1'.
• step portion 1 comprises two mutually displaceable step portion elements.
• the step portion constitutes a unit that is not adjustable to its length.
• the knee support is important from a security aspect but that said knee support does not have a direct connection with the transferring possibilities of the hinge device according to the present invention.
• the apart sliding security device constitutes an articulated arm 16.
• other types of apart sliding security devices especially so-called platforms in connection with ladders of the type m question, said platforms simultaneously constituting a standing spot for the user and an apart sliding security device.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Ladders (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=20414132

Family Applications (1)

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Family Cites Families (6)

• 1999
  • 1999-01-19 SE SE9900133A patent/SE515015C2/sv not_active IP Right Cessation
• 2000
  • 2000-01-19 WO PCT/SE2000/000104 patent/WO2000043627A1/en not_active Application Discontinuation
  • 2000-01-19 EP EP00902262A patent/EP1147281A1/en not_active Withdrawn
  • 2000-01-19 AU AU23389/00A patent/AU2338900A/en not_active Abandoned

Non-Patent Citations (1)

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