FR2862997A1 - Folding loft ladder is made from thin steel or aluminum sections to reduce stowage space requirement - Google Patents

Abstract

The ladder (2), designed to fit inside a trap door (1) in a loft floor, is made in three hinged sections that deploy from ceiling to floor and are retracted with the aid of a pulley and cable system. Each section has steel or aluminum side supports and rungs of dimensions that take up a minimal amount of space when retracted. The rungs are fitted with non-slip wooden treads that fit between the ladder section uprights in the retracted position.

Description

This staircase is in the technical field of retractable steel stairs

or aluminum.

  The arrangement of the steps, which fit into the volume occupied by the three tubes of 25x25x3 square section if these tubes are aluminum, section 25x25x2mm if these tubes are 5 steel; is particular. The antislip steps in 18mm thick wood are screwed onto the 30x20x2mm section aluminum crimpers. Two; rivets of diameter 4mm fix each angle on the tube (2) in aluminum or steel. The wooden steps have a dimension of 390x80x18mm, they can be of trapezoid shape to marry just the space occupied by the three tubes superimposed, account given the angle of 70 that make the axis of the step 10 and the axis of the tube. The screws are 4x15 wood screws.

  The steel frame of 30x30x3mm section consists of four pieces welded together. (I Lt-) The overall dimensions of this frame is 1250x690mm. The steel flat iron (7) of section 20x3mm is welded on the angle of the frame, giving it moreover a certain rigidity. 18mm thick hatch. The AA cut (see drawing / 3) makes it possible to see the rubber seal 15 which makes hermetic the hatch which is articulated and fixed on two rods (8) of diameter 20 mm hardened hardened steel, these two axes of rotation have a length of 200mm each. Flat irons welded on these axes connect them to the hatch, axes and flat irons are drilled and crossed by four bolts of diameter 8mm. The axis of rotation is inside a steel tube (17) with an outer diameter of 26.9 mm and a thickness of 2.3 mm, this tube, on the short length required, which is placed on the angle, is welded on the It is also supported by a welded gusset which reinforces this area subjected to intense effort.

  Two pulleys attached to the hatch allow the passage of a nylon cable, a third Pulley (not shown) attached to a joist or wooden frame supporting the hole in the ceiling. This nylon cable is also fixed on this wooden frame but of course on the side where the axis of rotation is almost at the floor, the other end of this nylon cable is of course a muffle or hoist stop automatic (fixed to a beam of the attic). . It should be noted that this is a luxury because a wooden pole with a corkscrew tip will do just as well. This staircase supports a load of 150kgs.

  The location of the steps contributes strongly (with other processes mentioned later to make this staircase as thin as possible to make it contain under the floor of the attic) to the small thickness of the whole.

  Two drawings are enough because in fact describe the classic fittings, springs, would serve no purpose. However, it is obvious that, since the staircase is fixed to the trapdoor, it also acts as a fulcrum and therefore, the fitting called compass is indispensable, it is the same for traction springs. (not shown)

  Two things are new compared to the stairs of old technique, the location-Ment of the stairs on the one hand and on the other hand the fact that the staircase is provided with fixing feet (5) cut at an angle 17, which allows by rotation to lower (the thickness of the whole once closed) of 29mm 40.

  In line 22 of the previous page, read: gusset (21) welded.

  In line 33 of the previous page it is necessary to read: three drawings are enough.

  The drawing 3/3 peiniet to see that in fact, one can bring the trapdoor (1) aluminum flush plane (6), (see drawings 3/3 and 1/3). In fact we can lower the axis of rotation (8) to the plane (6) 5 (see drawing 1/3) of 26mm by adopting a 40/10 aluminum alloy 1050 thickness trapdoor (A5). The bolt (27) can be placed on the shaft side nut (8) and not side hatch as shown here in the drawing 3/3 to save space and for more aesthetic. In the drawing 3/3, we see that the washer (28) separates the axis (8) of the hatch (1).

  The gussets (24) are actually four, since the same thing happens on the second axis of rotation (side of the frame to the right of the longitudinal axis of the hatch), the four gussets (24) are welded on the sleeve tube (17) and on the angle which gives this area of the frame a strong resistance to effort.

  The 15x15x1,5mm aluminum angle (29) is fixed to the steel angle frame by pop steel rivets of 4mm diameter, it is not placed in the same way as the aluminum angle (30) of the same section. The effect in top view (if we consider that Figure 1 of drawing 1/3 is the front view) on the top view which results at the positioning level of the person looking at the staircase. the hatch (1) bears on the flat part of the aluminum angle (30) while the top of the hatch (1) bears on the flat part of the angle (29); the two pieces of aluminum angle although placed on the same piece of steel angle are not placed in the same way on both sides of the axis (8) of fixing and rotation.20 Wooden slats screwed on the frame; not essential (since the 27mm of the angle leave a considerable margin of error in case of cutting of the ceiling (with jigsaw) or the disc wheel, can be used both vertically and horizontally, these wooden slats ( 25) of small thickness of 60x3mm section placed horizontally will have a larger footprint if it is a question of dressing the void left between the ceiling and the floor (see latte bearing the number (31,1 The tube (20) of circular section 15 / 2lmermeasurecomplementary security, the hatch (1) to be fixed by compass furs to the joists of the ceiling or wooden frame supporting the cut-out hole in the ceiling.The two tension springs (not shown for 30plus clarity) , placed on both sides of the bracket (20mm outer diameter steel) will connect the trapdoor (1) to the joists or wooden frame supporting the hole, they will rest at a length of less than 1090mm. pin (22) allows the fixing of the threaded rod 14mm diameter hardened hard steel (fine pitch) which is screwed on the square iron also hard hardened steel; a hexagonal head screw of adequate length of hardened hardened steel will also do the trick.

  The translation of the tube (5) 40mm does not exceed the overall dimensions of the frame. This staircase is of course part of the foldable and retractable stairs.

  Line 28 on the second page of the description, read: Compas hardware.

  Line 9 of the second page of the description, read: who are actually eight.

  Line 11 of the second page of the description, read. eight gussets (24). 5 Flat iron (3) of section 20x5mm On the first page of the description, it is necessary to read in the eighth line: to be of the form of a parallelogram 'Of course the drawing 3/3 represents the whole hatch (1) closed with the tubes (5) lowered to their minimum dimension 10 The two axes (34), see drawing 3/3, are the horizontal and vertical of the tube (2) located closest to the hatch. Line (1) of this page must be understood that by lowering the stairs, this one once placed under the floor of the attic will not come bump on the frame (14) or the joists.

  The drawing 3/3 shows well the gusset (23); in fact this new staircase and not the one shown drawing 1/3 may have four triangular gussets (23), two of which are at the same level as the flat iron (7) of the drawing 1/3 of the side of the support (13).

  Triangular gussets (32) in sheet of 3mm thick and welded to the frame (14) will be six in number for both stairs (see drawings 1/3 and 3/3).

  The drawing 3/3 shows the location of the rubber seal (26).

  Figure 3 of drawing 3/3 is actually part of the top view; Figure 1 being a partial front view in section.There are two washers (28) and two washers (35) Threaded rod (36) 8mm diameter steel with flat (welded on rod) section 450x20x3mm butterfly nut- and two-washers.

  The fastening (13) can be after welded adjustment (rod on nut) .This fact characterizes this staircase. The square iron located inside the tube (5) see drawing 2/3 characterizes this staircase. Two other triangular gussets (23) of dimension 24x24x3mm (see drawing 3/3) can be placed on the closing side of the hatch. to the fastener (13) replacing the flat iron (7) at the same level and therefore not down as the other two side axis (8), but at the top The use of hinges locksmith characterizes these two stairs (that of drawing 1/3 and that of the drawing 3/3), we could even say these four stairs since there are two steel and two aluminum 30. The tube (20) with its pin, with its fasteners on the rods (11) and (12) hardened steel diameter 14mm. Characterizes these stairs by relieving the hatch (1).

  In the drawing 3/3, the two axes (34) are the horizontal and vertical of the tube (2) see drawing 1/3. The threaded rod welded to a flat iron 450x20x3mm section and attached to the trapdoor (l) with wing nut allows to fix the staircase even if it is lowered by 29mm thanks to the tube (5). Line 26 page 1, read: axis of rotation (S). Line 25 page 3, read: square iron (r) Line 28 page 2, read in addition to what is written: the compass fitting will also be attached to the hatch (1). Line 27 page2, read essential safety The steel sleeves (15) can be welded to the steel pipe (2) by drilling a blind hole and drowning the weld (see point (38). If the pipe (2) is in aluminum, the sleeve (15) can be a square aluminum section of 18,5x18,5mm anodized and treated, therefore the axes (1l) and (12) in threaded aluminum end can penetrate a tapped hole d years (15) anodized after the tapping.The bolt (39) can if the sleeve tube (15) is steel be aimed inside the tube (2) steel if it is welded beforehand on a flat iron (drilled section 15x4mmun) a nut. We will put everything inside the tube (2) before welding the hinge .. The rivets (40) diameter4mm will be adequate depending on the metal and the strength of materials..I1 can be hot-dip galvanized steel, galvanized just like bolts and washers (black steel will never be used), we will at worst paint, anodize the aluminum, hot galvanize etc. The ri vets (40) falling in the square of aluminum can be placed if a blind hole is provided therein. The angles (4) aluminum or steel can be welded. The frame angle if it passes to Palu will be one greater thickness than for steel and everything will be anodized and treated against the phenomenon of electrolysis and others by the means already mentioned. 4 BIS

  Description staircase wooden steps (please)

  The aluminum will be anodized. Everything that exists in terms of the treatment and methods brought by the current technique to the steel contact will be implemented.

  Thus the steel will be painted, lacquered, before being in contact with the aluminum. The steel can be hot-dip galvanized. The steel can be hot-dip galvanized and painted with a suitable paint Savant montage.The steel and aluminum can be covered with a light layer of plastic with or without the treatments mentioned above. The bolts washers will follow the same treatment as the other parts mentioned above as soon as there will be contact aluminum steel (idem for the rivets). The steel will be protected as it is done for the steel axes of the aluminum hinges in The wooden steps will have a parallelogram-shaped section to fit the shape (70) and to have a maximum of width. Line28 page2: it is necessary to read: to the joists of the ceiling or to the wooden frame and to the hatch (1) Line 2 page 4 of the description, read: the threaded rod (36).

Claims (2)

  1 This device is in the field of stairs (aluminum or steel) retractable, it differs from the current technique by the position of the steps relative to each other is one of the characteristics of this staircase. The position of the steps allows an appreciable space saving. The box disappears, a hatch will be placed in floor of the attic The angle (4) is in aluminum of dimension 20x30x. 2 it is riveted thanks to two rivets on each alumunium tube (section 25x25x3) or steel (section25x25x2), it supports wooden steps of dimensions 318x80x20mm which are themselves fixed on the angle by bolts of diameter 8mm (with washers) or firmly fixed thanks to wood screws (diameter 4xl, 5).   The position of the steps characterizes this staircase.   Some elements of hardware are not represented on this drawing numbered 1/3 because to the scale where it is represented it generated more than anything else reading The steps are non-slip thanks to a light milling of the wood and the ends Tubes ( plastic) at the foot of the stairs are also anti-slip.   The steel hinges of 100mm (or more) for the staircase equipped with steel tubes (or aluminum tubes), can also be made of aluminum of 120mm, of adapted design io if the staircase is manufactured with aluminum tubes of section 25x25x3, in this case the hinges can be welded directly by the MIG process on the tube In all cases, however, the steel tubes used as reinforcing sleeves ser 20 fixed by bolts of diameter 8mm The sleeves are 18x18x1.5 section tubes. they can be removed if the staircase is made of 25x25x2 steel tubing.   The wooden hatch has a thickness of 18 mm, it can be insulated, thermally protected by modern means (thin) The frame in steel angle of 30xx30x3 section is fixed either on concrete thanks to the fixation (10) or on wooden joists thanks to the fixing (13). this last fixing is also removable The diameter rod 22mm will be in two pieces removable and fixed on the hatch by shims flat iron spacer.   In addition this staircase is characterized (see drawing 2/3) by its fixing on the hatch, the tubes (5) section 25x25x2 are cut at an angle of an angle of 17 which allows rotation of the whole to further reduce the l thickness of the 40mm staircase.   The tube (5) is reinforced by an inner square iron section 19x19 or 18/18 (Hard hardened steel) in the case where the tube (i5) used is aluminum. If the tube (5) used is 25x25x2 section steel, the square iron will be 20x20 section.   The axis (8) placed so flush (4mm from the plane (6)) through the sleeve tube (17) corked (in which it enters); tube (17) welded (and consolidating the axial zone) to the steel angle frame (bearing the number (14)) via the gussets (24); all these elements mentioned here are that: this set by consolidating the area and reducing the thickness of the staircase characterizes this staircase. 40 Dimensions are always given in mm Line 33 page 5: read, section 18,5x18,5 mm The coriéres (4) aluminum or steel can be welded instead of being riveted on the tube (2).   The eight tubes sleeves (15) will be 20x20x2mm section if the tube (2) is steel, they characterize this staircase.   The frame (14) characterizes this staircase; it is reinforced by eight gussets (32) steel sheet 3mm thick which also characterize this staircase.   There is nothing to prevent the wooden steps being replaced by steel or aluminum steps 10 (with different folds or ribs to give them more rigidity), in which case they will be riveted on the tubes (2), the thickness will be 6 / 10 or 8/10 mm.   This staircase is of course also foldable.   Line 7 page 5: read: 318x80x18mm. The sleeves (31) are made of non-slip plastic.   Four triangular gussets (23) can be placed at the four corners of the drawing frame 15 3/3 at different levels relative to the plane (6) to prevent the closing of the hatch (1), they characterize this staircase. The eight tube sleeves (15) will be 18x18x1.5mm steel section if the tube (2) is aluminum.   In fact it is enough to look at the three drawings numbered from 1/3 to 3/3: all the elements not employed until now characterize this staircase. The frame (14), the axis of rotation (8), the sleeve tube (17), the gussets (22), (23), (24) may be of aluminum. The aluminum hatch can go from 4mm to 6mm thick.   The displacement of the tube (5) of 40mm is not annoying, the staircase does not touch the frame (14) or the joists or wooden frame supporting the opening.   Line 32 pages: read 29mm instead of 40mm.   Line 21: read: are 18x18x1.5 section if the tube (2) aluminum is 25x25x3 section.   Line28: The 20mm diameter rod can be in one piece of equal length little different than the 690mm width of the set. Ligne3l: lire, tube (5) .Les tubes (5) characterize this escalator.Si equip the staircase with steel or aluminum riveted steps, obviously the useful width of the steps will also be 318x80 and no more (so that tubes (2) may well be on top of each other). The wooden steps will have a section in the shape of a parallelogram (not shown as in drawing 1/3).   The eight gussets (32) will be aluminum if the frame is aluminum; they will be welded by MIG or TIG process. 6 bis   Staircase steps wood (continued)   All that is drawn on these three drawings numbered from 1/3 to 3/3 is claimed and characterizes this staircase or rather these four stairs. The section of parallelogram-shaped steps and their respective positions relative to each other characterize this staircase. The steps can be steel sheet thickness 6 / l Omm or 8 / l0mm ribbed non-slip but they can be also aluminum which characterizes this staircase. Of course, all the precautions will have to be taken regarding the aluminum steel contact thanks to the current techniques (see the description on this subject) however, I repeat that the aluminum, will be anodized, this characterizes this staircase, the painted steel if contact with aluminum (which characterizes this staircase) 10The steel can be galvanized hot and painted with a special paint, or hot-dip galvanized and covered with a light plastic layer (all that has been said in this sentence characterizes this The steel can be protected as is done for the steel axes of the aluminum hinges or the steel is in contact with the aluminum which characterizes this staircase.Also we can design aluminum tubes (2) of square section 4mm thick profile or even 15m consolidate this profile by ribbing it inside, of course the shape and dimensions of the sleeves will be modified accordingly, all that has just been said because actérise this staircase Of course the square sleeves, tubes (5) can be aluminum The aluminum washers will have both sides plasticized which characterizes this staircase. The steps can be hot-dip galvanized steel with non-slip 20mm ribs 6 / 10mm riveted to steel pipe. It can be removed one side of (below) the parallelogram steel 20que constitute the steps and they can ds then be welded directly to the tube which characterizes this staircase. This staircase supports 150kgs. Line 9 pages: read: 4x20mm wood screws. Line 28 on page 5, read: Rod (8). See explanations on the description for the staircase shown on sheet 3/3. The aluminum steps can be riveted and treated against corrosion and placed on the steel or aluminum tubes (2). Finally the plastic sleeves (31) will be designed to be anti-slip.