EP2314797A1

EP2314797A1 - Moving scaffold

Info

Publication number: EP2314797A1
Application number: EP10167640A
Authority: EP
Inventors: Giorgio Turrisi
Original assignee: Gierre Srl
Current assignee: Gierre Srl
Priority date: 2009-10-22
Filing date: 2010-06-29
Publication date: 2011-04-27
Anticipated expiration: 2030-06-29
Also published as: EP2314797B1; EP2314796A1; ATE540179T1

Abstract

A cradle or movable scaffold comprises a frame defined by at least two pairs of vertical side shoulders (2), each pair having a plurality of rungs (3), disposed parallel to each other, at least one pair of horizontal crosspieces (4) transversely connecting the pairs of side shoulders (2) with each other, at least one flat support surface for workmen (5) located transversely between the pairs of side shoulders (2) and at least one brace (6) diagonally disposed between the pairs of side shoulders (2). The brace (6) is connected to the side shoulders (2) by a quick-fit mechanism (7) permanently connected to each end of each brace (6), said quick-fit mechanism comprising an elastically deformable dowel (9).

Description

The present invention relates to a moving scaffold.
Moving scaffolds, more commonly referred to as "cradles", are moving structures mainly used for small building works such as plastering or painting.
The moving scaffolds or cradles of known type are tubular structures made of aluminium or steel, having varying base sizes proportional to the height to which a work is to be made. Typically, these cradles are used for finish or servicing works at heights in the range of between 2 to 20 metres. The moving scaffold can be provided with at least one pair of wheels enabling the assembly to be moved manually and at will in the worksite.
Cradles comprise a frame consisting of two pairs of vertical side shoulders with steps or rungs and at least one pair of horizontal crosspieces connecting the two pairs of vertical shoulders with each other.
A stiffening element supports the articulated quadrilateral defined by the frame and prevents the structure from bending.
The stiffening elements are tie-rods or braces for example, that are disposed cross-wise in an oblique orientation and connect the shoulders to each other.
Finally, at least one flat support surface on which the operators stand is placed in a transverse direction relative to the side shoulders.
In the vicinity of, or at each rung, the vertical shoulders have holes aligned with the rung axis, for connection of the tie-rods.
In moving scaffolds of the known art, the tie-rods are tubular metal bars terminating at both ends with a slot. Each slot is able to be disposed axially superposed on said hole of the vertical shoulder, to which it is connected by a suitable fastening element. The latter can be a key or a knob with a threaded shank to maintain connection between tie-rod and vertical shoulder.
The key is generally a metal element comprising a pivot and a suitably shaped portion. The pivot is fitted through the tie-rod slot and one of the holes provided in the shoulder. Following rotation of the key around the pivot axis, the shaped portion is coupled to the vertical shoulder preventing disengagement of the tie-rod from the rest of the structure.
Alternatively, the fastening element can be a knob having a threaded shank to be screwed down within a threaded seat formed through the slot and the hole at the rung.
In both solutions, the fastening element is an additional component of the scaffold with which further elements such as spacers or safety latches are to be possibly associated.
Both the mounting and dismantling steps of the scaffold are therefore unpractical due to the presence of separated components that must be assembled to make the cradle safe.
The smallest parts, in particular the elements of the connecting mechanism between the tie-rods and vertical shoulders can get lost more easily because they may be separated from the remainder of the frame.
It is an object of the present invention to provide a moving scaffold or cradle that is devoid of the above described drawbacks.
In particular, the present invention aims at proposing a cradle that can be assembled in a quick and simple manner, while at the same time ensuring high safety levels.
It is a further aim of the invention to propose a cradle that is not equipped with individual elements of small sizes that can easily get lost.
Document FR 2 927 919 A1 proposes a moving scaffold in which the tie-rod ends are fastened to the shoulders by a quick-fit mechanism permanently connected to each end of each tie-rod.
In accordance with the present invention a moving scaffold or cradle is provided which comprises the features present in one or more of the appended claims.
The present invention is now described with reference to the accompanying drawings, illustrating a nonlimiting embodiment thereof, in which:

Fig. 1 shows a cradle in accordance with the present invention;
Fig. 2 shows a detail of a first embodiment of the cradle in accordance with the present invention in a first operating position;
Fig. 2a shows a detail seen in Fig. 2, to an enlarged scale;

Fig. 3 shows a detail of a first embodiment of the cradle in accordance with the present invention, in a second operating position;
Fig. 3a shows a detail seen in Fig. 3, to an enlarged scale;
Fig. 4 is an exploded view of a component shown in Figs. 2 and 3;
Fig. 5 is an exploded view of a component of the cradle according to the invention, in a second embodiment;
Figs. 6 and 7 are exploded views of further variants of the invention;
Figs. 8 and 9 are perspective views of two distinct components to be used in the variants shown in Figs. 6 and 7.

With reference to the drawings, a moving scaffold in accordance with the present invention has been generally identified with reference numeral 1.
The moving scaffold 1, commonly referred to as cradle, is defined by a frame having a tubular metal structure and comprising at least two pairs of vertical side shoulders 2 disposed parallel to each other and having a plurality of horizontal steps or rungs 3.
The ends of each rung are fitted into through openings obtained by cutting in the respective side shoulders 2, and fastened therein by riveting and/or welding. At each rung 3, the vertical shoulders 2 therefore have holes inside which a housing 8 is formed which can be utilised for connection with further structural elements.
Housing 8 communicates with the outside through an opening axially in alignment with the respective rung 3.
The frame defining the moving scaffold 1 further comprises at least one pair of horizontal crosspieces 4 connecting the pairs of vertical side shoulders 2 with each other.
Horizontally disposed between the pairs of side shoulders 2 is a flat support surface 5 or platform which preferably rests on a pair of rungs 3 and on which the operators work.
The frame of cradle 1 is an articulated quadrilateral; therefore the presence of at least one tie-rod or brace 6 acting as a stiffening element is required, said brace being diagonally disposed between the pairs of side shoulders 2.
Brace 6 is connected to the side shoulders 2 at two respective rungs 3, placed at different heights, by a quick-fit mechanism 7 permanently connected to each end 6b of brace 6.
In particular, the quick-fit mechanism 7 of each end of each brace 6 has an axial extension orthogonal to the axis 6a of brace 6, and is inserted into the housing 8 of a predetermined rung 3. In fact, brace 6 has a through hole 13 at each of its ends 6b. Preferably two or more braces 6 disposed cross-wise can be present.
Brace 6 can be a metal bar having a rectangular section Figs. 2-4 and 6) or a round bar (Figs. 5 and 7).
In the first case, shown in Figs. 2-4 and 6, an insert 20 (Fig. 4) of plastic material is positioned at the end 6b of each brace 6, which insert is adapted to fill the inner empty space at the end 6b of brace 6, making brace 6 stiffer at that exact point and being a support for it. As better explained in the following, in fact, brace 6 at its ends 6b is acted upon by a compression force.
In the second case, shown in Figs. 5 and 7, the end 6b of brace 6 is flattened, by pressing for example. Therefore, due to the particular conformation, use of filling elements is not required.
The quick-fit mechanism 7 comprises an elastically-deformable expandable dowel 9 to be axially fitted into housing 8 formed in the shoulder, at the rung 3 to which the brace 6 is to be connected. The expandable dowel 9 is connected to the end 6b of brace 6 by a pin 10 slidably inserted into the expandable dowel 9.
Pin 10 has a flanged, i.e. enlarged, head 10b pressing the expandable dowel 9 against one side of brace 6 so as to deform it.
Pin 10 extends along an axis 10a transverse to the longitudinal axis 6a of the respective brace 6. In particular, pin 10 passes through the end 6b of brace 6, inside hole 13, and has an end portion 10c, opposite to the flanged head 10b, that projects from brace 6.
A spacer 11, slidably passed through by pin 10 is present between the expandable dowel 9 and the side of brace 6.
The quick-fit mechanism 7 further comprises quick locking/unlocking means 12, connected to pin 10 and in particular to the end 10c of pin 10. The quick locking/unlocking means 12 is movable between an activation position (Fig. 3) at which the expandable dowel 9 is deformed and firmly locked within housing 8, and a deactivation position (Fig. 2) at which the expandable dowel 9 is in a rest position and can be disengaged from housing 8.
In particular, in the embodiments shown in Figs. 1 to 5, the locking/unlocking means 12 comprises a lever 14 connected by a peg 23 to the end 10c of pin 10. Lever 14 is able to rotate around a hinge axis 15 transverse to the axis 10a of pin 10.
Rotation of lever 14 causes the axial displacement of pin 10 towards lever 14 and the consequent compression of the expandable dowel 9 between the head 10b of pin 10 and the side of brace 6. In fact, lever 14 has an end cam 16 that, by interfering against the side of brace 6 during rotation of lever 14, causes the simultaneous moving apart of the hinge axis 15 from said brace 6. Following this movement, lever 14 pulls pin 10 and causes axial sliding of same.
In this way, the expandable dowel 9, compressed between the flanged head 10b of pin 10 and spacer 11, expands in the radial direction, i.e. a direction orthogonal to the axis 10a of pin 10, interfering by friction with the inner walls of housing 8.
This swelling causes locking of mechanism 7, and particularly of the expandable dowel 9, inside the housing, and ensures a steady and permanent connection between brace 6 and the vertical shoulders 2.
The end 6b of brace 6 is acted upon by compression, following rotation of lever 14 and sliding of pin 10. Therefore in case of a rectangular-section brace (Figs. 2-6), it is preferred and also advantageous that the stiffening insert 20 be introduced at the end 6b, thus giving the brace 6 a structural support due to the compression caused by the expandable dowel 9 and pin 10. On the contrary, the brace of circular section (Fig. 5) has a flat end 6b also provided with a hole 13.
In addition to spacer 11 between the brace 6 and expandable dowel 9, further spacers 22 can be advantageously present inside the quick-fit mechanism 7, to eliminate possible level differences between the various elements. For instance, when there is the mechanism 7 shown in Fig. 5, in addition to spacer 11 placed between the expandable dowel 9 and brace 6, a further spacer 22 is placed which is located between brace 6 and lever 14.
The outer edge of each housing 8 has a perimetric enlargement 16 obtained following a riveting and/or welding operation for example, carried out during the step of securing the end of rung 3 to the respective side shoulder 2. The enlargement 16 creates a mechanical interference with the compressed expandable dowel 9 so as to avoid accidental disengagement of said expandable dowel 9.
The cradle 1 can further comprise a safety device 17 maintaining the connection between the brace 6 and the vertical side shoulder 2 even when the expandable dowel 9, although inserted in housing 8, is not deformed. This safety device 17 comprises a suitably shaped plate hinged on the axis 10a of the mechanism 7.
The plate comprises a U-shaped portion 18 that, under work conditions, encompasses the vertical shoulder 2 to which brace 6 is connected. The plate can be positioned in the work condition, following an angular rotation around its hinging axis 10a, starting from a rest condition shown in Fig. 4 at which the U-shaped portion 18 is released from the vertical shoulder 2, so as to enable transverse movement of brace 6 for insertion and extraction of the expandable dowel 9 into and from housing 8.
The embodiments shown in Figs. 6 to 7 differ from the previously described ones due to the structure of the locking/unlocking means 12 comprising, instead of lever 14, a knob (114) connected to a corresponding end 10c of pin 10 opposite to the flanged head 10b. In this case the flanged head 10b is defined by a threaded nut 115a operatively engaged on the corresponding end of pin 10 and acting against the expandable dowel 9 after interposition of a washer 115b.
The knob 114 is adapted to be rotated about the geometric axis 10a, possibly together with pin 10, to promote axial sliding of the pin itself and consequent compression of the expandable dowel 9 between the head 10b and brace 6.
To this aim cam devices 116 are operatively interposed between the brace 6 and knob 114 to pull pin 10 and cause axial sliding of same, following rotation of the knob around axis 10a. The cam devices 116 preferably comprise at least one counter-lug 119 forward projecting from the knob 114 towards the brace 6, in parallel to axis 10a. The counter-lug 119 operates in slidable-rest relationship on a helical projection 120 extending around axis 10a of pin 10. In the example shown, two counter-lugs 119 are present which are diametrically opposite relative to axis 10a and cooperage with respective helical projections 120 carried by an abutment plate 121 interposed between the brace 6 and knob 114 and slidably passed through by pin 10. The abutment plate 121 can be provided with rotation-preventing protrusions 122 acting against opposite side walls of brace 6 to avoid undesirable rotations of the plate itself around axis 10a during operation of knob 114. In addition to or in place of the rotation-preventing protrusions 122, the abutment plate 121 may be provided with at least one rotation-preventing peg (not shown in the drawings) designed to be fitted into a respective hole 122a formed in the end of brace 6.
Mounting and dismantling of cradle 1 appears to be quick and braces 6 are firmly connected to the rest of the frame by means of the described quick-fit mechanism.
A mere angular rotation of lever 14 or of knob 114 ensures the steady connection of the brace to the rest of the frame, without running the risk of accidental separations.
The quick-fit mechanism is permanently connected to the brace, in such a manner that accidental losses of structural elements during the dismantling and transport steps cannot occur.

Claims

A cradle or moving scaffold comprising a frame defined by at least two pairs of vertical side shoulders (2) disposed parallel to each other, each pair having a plurality of rungs (3), at least one flat support surface for workmen (5) located transversely between the pairs of side shoulders (2) and at least one brace (6) diagonally disposed between the pairs of side shoulders (2), wherein said brace (6) is connected to said side shoulders (2) by a quick-fit mechanism (7) permanently connected to each end of each brace (6), wherein said side shoulders (2) have housings (8) communicating with the outside, characterised in that said quick-fit mechanism (7) comprises:
- an elastically-deformable expandable dowel (9), to be axially inserted into one of said housings.
A cradle as claimed in claim 1, wherein said quick-fit mechanism (7) comprises a pin (10) slidably inserted into said expandable dowel (9), said pin (10) having a flanged head (10b) axially compressing the expandable dowel (9) for radially expanding it.
A cradle as claimed in claim 2, wherein said pin (10) extends along an axis (10a) transverse to the longitudinal axis (6a) of the respective brace (6).
A cradle as claimed in claim 2 or 3, wherein said expandable dowel (9) is compressible between the flanged head (10b) of said pin (10) and one side of said brace (6).
A cradle as claimed in one or more of claims 2 to 4, wherein said quick-fit mechanism (7) comprises quick locking/unlocking means (7) connected to said pin (10) and movable between an activation position, at which the expandable dowel (9) is deformed and firmly locked inside the housing (8), and a deactivation position, at which the expandable dowel is in a rest position and can be released from the housing (8).
A cradle as claimed in one or more of claims 2 to 5, wherein said quick-fit mechanism (7) comprises a lever connected to one end (10c) of said pin (10) opposite to the flanged head (10b); said lever (14) being rotatable about a hinge axis (15) transverse to an axis (10a) of the pin (10) for promoting axial sliding of said pin and the consequent compression of said expandable dowel (9) between the head (10b) of the pin (10) and the brace (6).
A cradle as claimed in claim 6, wherein said lever (14) is disposed on the opposite side of said expandable dowel (9) relative to the brace (6); said lever (14) having a cam end (16) that, following rotation of the lever around the hinge axis (15), pulls the pin (10) and causes axial sliding of same.
A cradle as claimed in one or more of claims 2 to 5, wherein said quick-fit mechanism (7) comprises a knob (114) connected to one end (10c) of said pin (10) opposite to the flanged head (10b); said knob (114) being rotatable about the axis (10a) of the pin (10) to promote axial sliding of said pin and consequent compression of said expandable dowel (9) between the head (10b) of the pin (10) and the brace (6).
A cradle as claimed in claim 8, wherein said knob (114) is disposed on the opposite side of said expandable dowel (9) relative to the brace (6); cam devices (116) being operatively interposed between the brace (6) and said knob (114) to pull the pin (10) and cause axial sliding of same, following rotation of the knob around the axis (10a) of the pin (10).
A cradle as claimed in claim 9, wherein said cam devices (116) comprise at least one counter-lug (119) slidable on a helical projection (120) extending around the axis (10a) of the pin (10), one of which is integral with the knob (114) while the other is carried by an abutment plate (121) interposed between the brace (6) and the knob (114).
A cradle as claimed in one or more of claims 2 to 9, wherein said mechanism (7) further comprises at least one spacer (11) slidably passed through by the pin (10) and axially interposed between the expandable dowel (9) and the brace (6) .
A cradle as claimed in one or more of the preceding claims, wherein said mechanism (7) further comprises a safety device (17) ensuring connection between the brace (6) and the vertical side shoulder (2), wherein said safety device (17) comprises a shaped plate, hinged on the brace and having a U-shaped portion (18) encompassing the vertical shoulder (2) to which the brace (6) is connected.
A cradle as claimed in one or more of the preceding claims, wherein said housing (8) on an outer edge thereof has an enlargement (16) creating a mechanical interference with the expandable dowel (9) in the deformed configuration, to prevent the occurrence of an accidental disengagement of the expandable dowel (9) from the respective housing (8).
A cradle as claimed in one or more of the preceding claims, wherein said at least one brace has a tubular section with flattened ends, each carrying said quick-fit mechanism (7).
A cradle as claimed in one or more of the preceding claims, wherein said quick-fit mechanism (7) comprises at least one end insert (20) filling the empty end (6b) of the brace (6) of tubular section, to counteract compression stresses imposed to the end of the brace.