WO1992000432A2

WO1992000432A2 - Adjustable scaffolding for sloping surfaces

Info

Publication number: WO1992000432A2
Application number: PCT/FR1991/000522
Authority: WO
Inventors: Claude Jean-Marie Tagnon
Original assignee: Tagnon Claude Jean Marie
Priority date: 1990-07-02
Filing date: 1991-07-01
Publication date: 1992-01-09
Also published as: WO1992000432A3; EP0674741A1

Abstract

An adjustable scaffolding for sloping surfaces, particularly a straight or spiral staircase, comprises an element such as a work platform (2) for supporting a person working on said scaffolding. The scaffolding includes a horizontal frame (3) having attached thereto, at three points forming the three vertices (A, B, C) of an equilateral triangle, the upper ends of three legs (4, 5, 6) extending below the frame (3), as well as a platform support (7) which is rotatably mounted above the frame (3) for rotation thereon and around a vertical axis (z, z') which passes through the centre of gravity (0) of the equilateral triangle (ABC) defined by the upper ends of the three legs (4, 5, 6).

Description

ADJUSTABLE SCAFFOLD FOR SUPPORT ON A SLOPED SURFACE

The present invention relates to an adjustable scaffolding intended to rest on a sloping surface, in particular on a straight or rotating staircase.

When work must be carried out on the walls or ceiling of a part of a building where the floor is sloping, as is the case with a staircase, the masons, plasterers, painters etc. use as much as poorly available means, more or less unstable, such as a simple ladder with an adjustable foot.

To allow a work floor to be placed in a substantially stable horizontal position on a sloping surface, it has already been planned to use, as described in patent GB-A-2,150,195, three feet of adjustable height , which can be supported at points located at different levels, for example on different steps of a staircase. These height-adjustable feet support a work floor maintained in a horizontal position, but, since the support legs constitute individual units, the stability of the floor is not perfect and therefore total safety is not obtained. the person working on the work floor. The present invention aims to remedy these drawbacks by providing a scaffolding of particularly simple design, which can be easily put in place and ensuring excellent safety for the person working on his work floor.

To this end, this adjustable scaffolding intended to rest on a sloping surface, in particular on a straight or rotating staircase, comprising an element, such as a working floor, carrying a person working on the scaffolding, this carrying element resting on the sloping surface by means of three feet of adjustable height resting at points on the surface located at different levels, is characterized in that it comprises a horizontal frame to which are connected respectively, at three points constituting the three vertices of an equilateral triangle, the upper ends of the three feet extending below the chassis and a support for the carrier element, this support being mounted for rotation on the chassis, above the latter, around a vertical axis passing through the center of gravity of the equilateral triangle along which the upper ends of the three feet are arranged.

The three feet of the scaffolding can be fixedly connected to the lateral frame but preferably they are pivotally mounted on this frame, around respective horizontal axes, so as to be able to be retracted in the horizontal plane of the chassis and / or occupy two positions perpendicular to this plane, opposite 180 °. According to an additional characteristic of the invention, the width of the support of the carrier element is substantially equal to the diameter of the circle inscribed in the equilateral triangle, the vertices of which are formed by the upper ends of the three feet.

Various embodiments of the present invention will be described below, by way of nonlimiting examples, with reference to the appended drawings in which: FIG. 1 is a perspective view of an adjustable scaffold placed on a spiral staircase. FIG. 2 is an exploded perspective view of the various components of the scaffolding shown in FIG. 1.

Figure 3 is a partial exploded perspective view, on a larger scale, of a connecting device between the end of an articulated leg and the frame.

Figure 4 is a perspective view of an alternative embodiment of the scaffolding.

FIG. 5 is an elevation view, partially broken away, of a device for articulating a foot on the frame of the scaffolding, the foot being shown in a vertical position or perpendicular to the plane of the chassis.

Figure 6 is a view similar to that of Figure 5, the foot being shown in a horizontal position along the frame and above it.

Figure 7 is a view similar to that of Figure 6, in the case of an alternative embodiment in which the foot extends in a horizontal position below the frame. Figure 8 is a view, similar to that of Figure 5, in the case of an alternative embodiment of the articulation device of a foot.

The adjustable scaffolding according to the invention is shown in FIG. 1, as being mounted on a staircase 1, turning to the right, comprising several successive steps la, lb, lc, ld, le, lf etc. This scaffolding comprises an element carrying a person before working on the scaffolding. This load-bearing element is constituted, for example, by a horizontal work floor 2 which is carried by a horizontal frame 3 itself resting on three successive steps la, lb, lc of the staircase 1, by three vertical feet 4, 5.6 preferably made up of square section tubes. The three feet 4,5,6 are connected to the horizontal frame 3 at three respective points A, B, C which constitute the three vertices of an equilate¬ ral triangle. The work floor 2 is itself supported on a support 7 which is mounted mobile in rotation, on the chassis 3, above the latter, around a vertical axis zz 'passing through the center of gravity O of the equilateral tri¬ angle ABC. As can be seen in Figure 1, the vertical foot 4 which is supported on the lowest step la, is longer than the second foot 5 which is supported on the next higher step lb, this second foot being him - even longer than the third foot 6 which is supported on the highest step. The difference in height between feet 4 and 5 on the one hand and 5 and 6 on the other hand corresponds to the height of the steps. To allow fine adjustment of the length of each of the feet 4,5,6, each of these is provided at its lower end with a circular horizontal heel 8 which is welded, in its center, to a threaded rod vertical, which is screwed into a nut welded to the inside of the foot. Each heel is preferably coated with a non-slip sole. Therefore the adjustment of the effective length of each foot is obtained by screwing or unscrewing its heel 8. These heels 8 ^" allow the lengths of the respective feet to be adjusted so as to adapt them to different walking heights, and to hold the chassis 3 in a horizontal plane.

In the nonlimiting embodiment shown in FIGS. 1 and 2, the support 7 of the work floor 2 is constituted by a vertical frame comprising a lower cross member 9, an intermediate cross member 11 and an upper cross member 12, as well as two vertical side members 13 and 14. The lower cross member 9 is rigidly fixed to the two vertical side members 13,14, while the intermediate cross member 11 on which the work floor 2 is supported, is adjustable in height on these two beams. To this end, it is preferably fitted into the two vertical beams 13, 14 and its immobilization, in an adjustable vertical position, is carried out, for example, by means of pins passing through holes drilled in the cross member 11 and in the beams 13, 14. The adjustable cross-member 11 is immobilized in a position whose level corresponds substantially to that of the upper step lf on which the work floor 2 is supported.

According to a particular characteristic of the scaffolding according to the invention, the frame 7 has a width, in other words, the crosspieces 9, 11, 12 of this frame have a length which is substantially equal to the diameter of the circle inscribed in the equilateral triangle ABC , which increases the stability of the entire scaffolding. In the nonlimiting embodiment shown in Figures 1 and 2, the horizontal frame 3 comprises, in its central part, a base 15 rotatably supporting the vertical frame 7. This base 15 may be constituted by two superimposed horizontal plates, for example in the form of an equilateral triangle. These two plates are kept at a distance from each other and are crossed vertically, right through at their centers, by a round tube 16 extending beyond the base 15, on each side thereof. this. In this round tube 16 fits a vertical pin 17 welded in the middle of the lower cross member 9 of the frame 7, extending downward and of a diameter corresponding to the inside diameter of the tube 16. Between the plates of the base 15 extend the internal end portions of three arms 18, preferably formed by sections of tube with a square cross section, these arms 18 being welded to the two plates of the base 15 and oriented along the heights of the equilateral triangle ABC . At the outer end of each arm 18 are fixed two parallel vertical cheeks 19, defining a housing for the upper upper part of the associated vertical foot 4,5,6. Each of the vertical cheeks 19 is pierced with three equidistant holes 21, 22, 23, aligned vertically with one another and horizontally with those of the other cheek 19, and the two opposite median holes 22 of the two cheeks 19 are crossed by an axis of articulation 24 between the associated foot, for example foot 4 in FIG. 3, and the chassis 3. For this purpose the upper upper part of the foot 4 is pierced with two holes 25,26, vertically aligned and whose center distance corresponds to that of the holes 21,22,23. The lower hole 26 is crossed by the hinge pin 24 while the upper hole 25 of the foot 4 is crossed by a removable pin 27 also passing through the holes 21 or 23 of the cheeks 19, depending on the position of the foot 4. By therefore each foot, such as foot 4, can occupy two vertical positions 180 ° opposite to each other, being held in each of these two positions by the pin 27. This device therefore makes it possible to reverse the feet 4,5,6, by passing them from one side to the other of the frame 3, to easily pass from a staircase turning to the right to a staircase turning to the left by completely reversing the frame 3. This device also makes it possible to fold each of the feet 4,5,6 against the chassis 3, in order to limit its size during transport or storage.

In the embodiment shown in Figures 1 and 2, the working floor 2 consists of a rigid rectangular plate 28, for example of plywood, fixed, along its two long longitudinal sides, with two parallel beams horizontal 29.31. A side panel 32 (FIG. 2) may possibly be included in the bolting, its height above the upper plane of the rigid plate 28 being sufficient to prevent any escape of a foot a stepladder resting on the work floor.

As can be seen in FIG. 1, in the case of a staircase turning to the right, the right spar 31 of the working floor 2 is in direct support on the highest step lf while the left spar 29 is supported on the step immediately below the, by means of a removable auxiliary foot 33, which is also also adjustable in height by having for this purpose a lower heel 8. This foot 33 is in the form of a square and it has a horizontal upper branch 33a can be engaged in the tubular beams 29.31.

The upper cross member 12 of the frame 7 is always higher than the plane of the working floor 2 so as to set a limit not to be crossed when the length of the floor 2 exceeds the vertical plane of the frame 7. This upper cross member 12 plays only the role of barrier and it is preferably liftable so as to facilitate the introduction of the floor 2 in the frame 7.

From the above description, it can be seen that the scaffolding according to the invention ensures perfect stability of the chassis 3 and therefore of the working floor 2. The three feet 4,5,6 of the chassis 3 always find support on three successive steps la, lb, lc and this whatever their position apart towards the outside of the rotating part. As we can see it in FIG. 2 in the case of a staircase turning to the left, the foot 5 of intermediate length is placed on the narrow part of the intermediate step lb, that is to say towards the center of rotation of the part turning the stairs. Furthermore, once the frame 3 thus installed and thanks to the possibility of orienting the frame 7 around the vertical axis of rotation zz ′ and more or less engaging the floor 2 in the frame 7, the following scaffolding the invention provides a working floor 2 whose horizontal axis is parallel to the wall on which one must work.

In the case where the scaffolding is used with a straight staircase, the auxiliary foot 33 of the working floor 2 is not used and this floor rests directly on the upper support step lf, by the end parts of its two longitudinal members 29.31.

We will now describe, with reference to FIG. 4, an alternative embodiment of the scaffolding in which the support of the carrier element, here constituted by a ladder 35, is a U-shaped section 34 of suitable width for wedging the two feet of the ladder 35 and comprising a stop block 36 at each of its ends. This profile 36 is integral, in the middle of its lower part, with the pin 17 engaged in the tube 16 and allowing the rotation of the profile 36 around the vertical axis zz '. Profile 36 here again preferably has a length substantially equal to the diameter of the circle inscribed in the equilateral triangle ABC. The correct inclination of the ladder 35 depends on the distance between the wall and the frame 3. FIG. 4 shows that the foot 5 ensures perfect stability of the scaffolding.

We will now describe, with reference to FIGS. 5 and 6, a device which can be used for the articulation of a foot 4 on the frame 3 and making it possible to adjust the length of this foot at will. The foot 4, of tubular shape with circular or polygonal section, in particular square or rectangular, of longitudinal axis xx ′, is mounted to slide freely inside a coaxial guide sleeve 37 whose internal cross section corresponds to the external cross section of the tubular leg 4. The guide sleeve 37 and therefore the tubular leg 4 are mounted to rotate about a horizontal axis 38 on a support 39 integral with the end part of an arm 18 of the chassis 3. For this purpose the guide sleeve 37 is welded to a lug 41 extending radially outwards and whose axis yy 'is perpendicular to the common axis xx ¹ of the sleeve 37 and of the foot 4 and passes through the middle of the length of the guide sleeve 37. The axis xx 'is thus orientable in a plane defined by the two axes xx' and yy 'and which is the plane of the figure in the drawing. The axis of rotation 38 passes through the support 39 which consists, for example, of two rectangular plates parallel to the plane xx ', yy ¹ , located on either side of the tab 41 and having horizontal upper sides 39a and external vertical sides 39b. The ends of the axis of rotation 38 are engaged in two opposite holes drilled in the two plates constituting the support 39, in the upper external corner of these plates, so as to allow free rotation of the guide sleeve 37 around the axis of rotation 38. The axis xx ′ can thus take two different orientations of 90 °, in which it is respectively parallel to the horizontal sides 39a and to the vertical sides 39b of the rectangular support plates 39. Two lugs 42 and 43, integral support plates 39 extend respectively vertically and horizontally, that is to say perpendicular to the sides 39a, 39b of the support plates 39 and their axes are located in the plane xx ', yy'. The vertical lug 42 extends upward from the upper horizontal edge 39a, and the horizontal lug 43 which is located in the lower outer corner of the support plates 39 extends outward from the vertical edge 39b. The distance between the axis of each of the pins 42,43 and the axis of rotation 38 is such that in no case can the guide sleeve 37 come into abutment on either of the pins 42,43 . Foot 4 is drilled at intervals regular, of holes 44, which extend along a generatrix located in the plane defined by the axes xx 'and yy', on the side of the axis of rotation 38. The length of the pins 41,42 is such that 'they can enter a hole 44 in the tubular leg 4, when the axis xx' is vertical or horizontal, that is to say parallel to one or the other of the sides 39a, 39b of the angle of the support 39. When one of the holes 44 arrives in front of one of the lugs 42 or 43, the latter is slightly biased and the corresponding lug can only enter the hole 44 if the latter has a larger diameter than that of the lugs 42.43.

The movable assembly formed by the guide sleeve 37 and the foot 4 can be immobilized, in one or the other of the two vertical and horizontal positions shown respectively in Figures 5 and 6, by a locking system by pin or by trigger. In Figures 5 and 6 is shown a pin locking device and for this purpose the tab 41 is pierced, opposite the sleeve 37 relative to the axis of rotation 38, a hole 45 located at a distance d of the axis of rotation 38 and on the axis yy 'of the lug 41. To this hole 45 correspond two holes 46 and 47 drilled, in the support 39, at the distance d from the axis of rotation 38 and aligned respectively horizontally and vertically with this axis. These holes 46, 47 are located so that the hole 45 of the tab 41 can only be in front of hole 46 or hole 47 when the lug 43 or lug 42 is engaged respectively in one of the holes 44 of the tubular leg 4. A pin 48, inserted in the holes 45 and 46 (Figure 5), thus maintains the foot 4 in its vertical position, that is to say perpendicular to the frame 3, while when the pin 48 is inserted into the holes 45 and 47 (Figure 6), it maintains the tubular leg 4 in a horizontal position above the chassis 3.

According to an alternative embodiment, as shown in FIG. 7, the axis of rotation 38 is placed in the lower external corner of the support plates 39, which makes it possible to retract the foot 4 in a horizontal position under the chassis 3. In in this case, the vertical lug 42 extends downwards from the lower horizontal edge 39c of the support plates 39, and the horizontal lug comes from the upper external angle of the support plates 39. In the variant shown in FIG. 8 the lug 42 is removed and the guide sleeve 37 carries a device 49 for clamping the foot 4 in the sleeve 37, which makes it possible to remove the play between the foot 4 and the sleeve 37. This clamping device 49 makes it possible to maintain, by itself, the foot 4 in the storage position, that is to say parallel to the chassis 3. The devices represented in FIGS. 5 to 8 offer the advantage that they make it possible to vary, very easily, the active length of the foot, that is to say that of the part situated below the sleeve 37, in vertical position of the foot, and this by appropriately choosing that of the holes 44 into which the lug 43 engages in the vertical position of the foot (FIG. 5).

Claims

1.- Adjustable scaffolding intended to rest on a sloping surface, in particular on a straight or rotating staircase, comprising an element, such as a working floor (2), carrying a person working on the scaffolding, this load-bearing element resting on the sloping surface by means of three feet (4,5,6) of adjustable height resting at points on the surface situated at different levels characterized in that it comprises a horizontal frame

(3) to which are connected respectively, at three points constituting the three vertices (A, B, C) of an equilateral triangle, the upper ends of the three feet

(4,5,6) extending below the chassis (3) and a support (7,34) of the carrier element, this support (7,34) being rotatably mounted on the chassis (3), at -above it, around a vertical axis (z, z ') passing through the center of gravity (0) of the equilateral triangle (ABC) along which the upper ends of the three feet are arranged (4,5,6 ).

2.- Scaffolding according to claim 1 characterized in that the width of the support (7,34) of the carrier element is substantially equal to the diameter of the circle inscribed in the equilateral triangle (ABC) whose vertices are formed by the upper ends of the three feet (4,5,6). •

3.- Scaffolding according to any one of previous claims characterized in that the horizontal frame (3) comprises, in its central part, a base (15) traversed vertically, right through, by a round tube (16), extending beyond the base (15), on each side thereof and in which fits a vertical vortex (17) integral with the middle of the carrier element (7,34), extending downward and of a diameter corresponding to the inside diameter of the tube (16). 4.- Scaffolding according to claim 3 characterized in that the base (15) consists of two superimposed horizontal plates, kept at a distance from each other and crossed vertically by the round tube (16), and between the base plates (15) extend the inner end portions of three arms (18) welded to the two base plates (15) and oriented along the heights of the equilateral triangle (ABC).

5.- Scaffolding according to claim 4 characterized in that each of the feet (4,5,6) is articulated on the outer outer part of an arm ^" (18) of the frame (3), around a horizontal axis ( 24.38).

6.- Scaffolding according to claim 5 characterized in that at the outer end of each arm (18) are fixed two parallel vertical cheeks

(19), delimiting a housing for the upper extreme part of the associated vertical foot (4,5,6), each vertical cheeks (19) is pierced with three equidistant holes (21,22,23), aligned vertically between them and horizontally with those of the other cheek, the two opposite median holes (22) of the two cheeks (19) are crossed by a hinge pin (24) between the associated foot and the frame (3), the upper end part of the foot is pierced by two holes (25,26), aligned vertically and whose center distance corresponds to that of holes (21,22,23), the lower hole (26) being crossed by the hinge pin (24) while the upper hole (25) of the foot is crossed by a removable pin (27) also passing through the holes (21) or (23) of the cheeks (19), depending on the position of the foot (4), so that each foot (4,5,6) can occupy two vertical positions opposite 180 ° to each other other, being held in each of these two positions by the pin (27).

1. - Scaffolding according to claim 5 characterized in that the foot (4), of tubular shape with circular or polygonal section, in particular square or rectangular, of longitudinal axis (xx '), is mounted to slide freely inside a coaxial guide sleeve (37) whose internal cross section corresponds to the external cross section of the tubular leg (4), the guide sleeve (37) and therefore the tubular leg (4) are rotatably mounted around a horizontal axis (38), on a support (39) integral with the end part of an arm (18) of the chassis (3), the guide sleeve (37) is welded to a lug (41) extending radially outwards and whose axis (yy ¹ ) is perpendicular to the common axis (xx ¹ ) of the sleeve (37) and the foot (4) and passes through the middle of the length of the guide sleeve (37), two lugs (42) and (43 ), integral with the support (39), ^' extend respectively vertically upwards and horizontally outwards, the foot (4) is pierced, at regular intervals, with holes (44), which extend along 'a generator located in the plane defined by the axes (xx') and (yy ¹ ), on the side of the axis of rotation (38), and the length of the pins (41,42) is such that they can penetrate in a hole (44) in the tubular leg (4), when the axis (xx ¹ ) is vertical or horizontal.

8.- Scaffolding according to claim 7 characterized in that the movable assembly formed by the guide sleeve (37) and the foot (4) can be immobilized, in one or the other of the two vertical and horizontal positions by a locking system by pin or trigger.

9.- Scaffolding according to claim 8 characterized in that the tab (41) is pierced, opposite the sleeve (37) relative to the axis of rotation (38), a hole (45) located at a distance (d) from the axis of rotation (38) and on the axis (yy ¹ ) of the tab (41), to this hole (45) correspond two holes (46,47) drilled in the support (39), at the distance (d) from the axis of rotation (38) and aligned respectively to the horizontal and vertically with this axis, these holes (46,47) being located so that the hole (45) of the tab (41) cannot be opposite the hole (46) or the hole (47), to allow the introduction of a locking pin (48) in these holes, only when the lug (43) or the lug (42) is respectively engaged in one of the holes (44) of the tubular leg (4) .

10.- Scaffolding according to any one of the preceding claims, characterized in that the carrying element (2) is a work floor and its support is constituted by a vertical frame comprising a lower crosspiece (9), an intermediate crosspiece (11 ) and an upper cross member (12), as well as two vertical side members (13,14), the lower cross member (9) is rigidly fixed to the two vertical side members (13,14), while the intermediate cross member (11) on which takes support the work floor (2), is adjustable in height on these two beams.

11.- Scaffolding according to any one of claims 1 to 9 characterized in that the carrier element (35) is a ladder and the support (34) is constituted by a U-shaped section of suitable width for wedging the two feet of the ladder (35) and having a stop block (36) at each of its ends.