Classifications

• • E—FIXED CONSTRUCTIONS
  • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
  • E06C—LADDERS
  • E06C7/00—Component parts, supporting parts, or accessories
  • E06C7/08—Special construction of longitudinal members, or rungs or other treads
  • E06C7/082—Connections between rungs or treads and longitudinal members
  • E06C7/085—Connections between rungs or treads and longitudinal members achieved by deforming the rung or the stile
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D39/00—Application of procedures in order to connect objects or parts, e.g. coating with sheet metal otherwise than by plating; Tube expanders
  • B21D39/06—Application of procedures in order to connect objects or parts, e.g. coating with sheet metal otherwise than by plating; Tube expanders of tubes in openings, e.g. rolling-in

Definitions

• the invention relates to a rigid connection method between a tubular metallic element and a flat metallic element particularly applicable to the automatic mounting of bars on open profiles particularly in the field of ladders and stepladders made of metal or the like.
• open profile means the profile of an upright having only a flat framework on which the ends of the bars are secured.
• this assembly can be automated, however it requires an additional part to obtain the fixing, which significantly increases the cost of connection; on the other hand, the solidity of such a connection remains relatively random insofar as one essentially plays on the metal elasticity of the bar inside a cut in the open profile, which excludes any resistance to the shearing or tilting force of the bar relative to the upright.
• a run is made on the planar element centered at the point of intersection (O) with the axis ZZ ′ of the tubular element comprising a first cut of lower cross section and advantageously homothetic of the tubular element, then radial cuts, all coming from (O) and extending a little beyond the periphery of the projection of the tubular element on the planar element, in limited number to form between the ends of two successive radial cuts a line of folding at 90 ° and on the same outer side of the planar element for each portion of the sector thus delimited,
• the previous assembly is pushed back by a new folding of 90 ° in the direction of the flat element bringing the sectors in a plane parallel to said element with which they form a first U-shaped groove to firmly clamp the l end of the tubular element twice rolled up to form a second inverted U-shaped groove and nested in the first groove.
• the term “joggling” is understood to mean the operation by which the drilling of a plate, in principle of metal, is obtained, consisting in carrying out from a central point in the drilling, radial cuts determining between them sectors that the at least orthogonally flap to define an opening corresponding to the desired hole.
• the fixing obtained by the method of the invention in nested double U, provides a remarkable mechanical strength between the tubular element and the planar element in all directions of space without 'it is necessary to have recourse to a third connecting piece and no more to a pre-folding of the tubular elements which limits, as we have seen, the automatic mounting in particular in applications to ladders or stepladders.
• FIG. 1 is a partial perspective view and in elevation of a connection according to the invention showing in a partial section the connection between the vertical upright with an open profile and a horizontal smooth bar,
• FIGS. 2 and 3 show in vertical lateral section (2â, 3â) and in front view (2b, 3b a partial view of the planar element on which a drilling has been carried out intended to receive a smooth bar of square section,
• FIG. 4 is a partial half-view in elevation and in section of the first step of assembling a smooth bar in the routing carried out as in the preceding figures on a flat element
• FIG. 5 shows the last step of the method according to the invention by which the rigid attachment is obtained.
• a specific example of a rigid connection between a smooth bar 1 and the vertical upright 2 with an open profile for example of a metal ladder, of which all the bars would of course be fixed, will be described. the same way to the two vertical uprights with open profile.
• a first folding operation will then be carried out consisting in bringing the sector portions 5 into a horizontal position (according to arrow F in FIG. 3a), that is to say substantially at 90 ° from the external face 21 of the vertical upright 2, the folding taking place along the lines connecting the ends of two successive radial cuts 4, that is to say in our example along the lines AB, BC, CD, and DA.
• a vertical upright 2 which has just been described to accommodate a smooth bar 1 of square section would be easily adapted by those skilled in the art to all forms of bars such as bars with circular sections or polygonal; only the number of radials 4 would then be different, the general principle of the process which will now be explained, naturally remaining the same.
• the smooth side bar 1 is then preferably introduced through the inner side 22 of the vertical upright 2 and along the axis ZZ ′ into the groove as described above.
• the bar 1 is introduced in the direction of arrow I in FIG. 4 into the groove in such a way that its end 6 (on the right in FIG. 4) exceeds the distal end A'B ', B'C, CD' , D'A 'portions of sectors 5 such as folded at right angles in the preceding steps; the end 6 of the bar 1 is positioned relative to the line of the edge A'B 'of a sector 5 of a value slightly less than the folding height of said sectors 5, equivalent to the distance between the two lines AB and A'B ', etc ...
• the wall of the latter is then pushed back by a conventional drawing tool disposed at the end 6 of the bar 1 so that it is rolled up towards the outside of the bar as indicated by the arrow G in FIG. 4; the material is pushed back until the wall of the bar 1 is brought around and above the sectors 5 which it therefore completely surrounds by folding back 180 °, that is to say in direction of the outer wall 21 of the vertical element 2.

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

Applications Claiming Priority (3)

Publications (1)

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ID=9548877

Family Applications (1)

Country Status (5)

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Family Cites Families (3)

• 1999
  • 1999-08-04 FR FR9910117A patent/FR2797206B1/fr not_active Expired - Fee Related
• 2000
  • 2000-08-02 WO PCT/FR2000/002221 patent/WO2001010581A1/fr not_active Application Discontinuation
  • 2000-08-02 CA CA002391731A patent/CA2391731A1/fr not_active Abandoned
  • 2000-08-02 AU AU68485/00A patent/AU6848500A/en not_active Abandoned
  • 2000-08-02 EP EP00956597A patent/EP1232028A1/de not_active Withdrawn

Non-Patent Citations (1)

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