EP2314796A1

EP2314796A1 - Cradle

Info

Publication number: EP2314796A1
Application number: EP09425419A
Authority: EP
Inventors: Giorgio Turrisi
Original assignee: Gierre Srl
Current assignee: Gierre Srl
Priority date: 2009-10-22
Filing date: 2009-10-22
Publication date: 2011-04-27
Also published as: EP2314797B1; ATE540179T1; EP2314797A1

Abstract

A cradle 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).

Description

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 part, 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.
In accordance with the present invention a moving scaffold or cradle is provided with 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.

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, 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 scaffold1 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 the cradle 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) or a round bar (Fig. 5).
In the first case, shown in Figs. 2-4, 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 Fig. 5, 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 screw anchor 9 to be axially fitted into housing 8 formed in the shoulder, at the rung 3 to which brace 6 is to be connected. The screw anchor 9 is connected to the end 6b of brace 6 by a pin 10 slidably inserted into the screw anchor 9.
Pin 10 has a flanged head 10b pressing the screw anchor 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 screw anchor 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 screw anchor 9 is deformed and firmly locked within housing 8, and a deactivation position (Fig. 2) at which the screw anchor 9 is in a rest position and can be disengaged from housing 8.
In particular, 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 screw anchor 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 screw anchor 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 screw anchor 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 a stiffening insert 20 be introduced at the end 6b, thus giving the brace 6 a structural support due to the compression caused by the screw anchor 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 screw anchor 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 screw anchor 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 an 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 screw anchor 9 so as to avoid accidental disengagement of said screw anchor 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 screw anchor 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 screw anchor 9 into and from housing 8.
Mounting and dismantling of cradle 1 appears to be quick and the braces 6 are firmly connected to the rest of the frame by means of the described quick-fit mechanism.
A mere rotation of lever 14 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), characterised in that 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).
A cradle as claimed in claim 1, wherein said side shoulders (2) have housings (8) communicating with the outside, said quick-fit mechanism (7) comprising an elastically deformable screw anchor (9), to be axially inserted into one of said housings.
A cradle as claimed in the preceding claim, wherein each of said housings (8) is placed at a respective end of a rung (3) into which said screw anchor (9) is axially insertable.
A cradle as claimed in claim 2 or 3, wherein said quick-fit mechanism (7) comprises a pin (10) slidably inserted into said screw anchor (9); said pin (10) having a flanged head (10b) axially compressing the screw anchor (9) for radially expanding it.
A cradle as claimed in claim 4, 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 4 or 5, wherein said screw anchor (9) is pressed between the flanged head (10b) of said pin (10) and one side of said brace (6) .
A cradle as claimed in claim 6, 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 screw anchor (9) is deformed and firmly locked inside the housing (8), and a deactivation position, at which the screw anchor is in a rest position and can be released from the housing (8).
A cradle as claimed in one or more of claims 4 to 7, 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 the axis (10a) of the pin (10) for promoting axial sliding of said pin and the consequent compression of said screw anchor (9) between the head (10b) of the pin (10) and the brace (6).
A cradle as claimed in claim 8, wherein said lever (14) is disposed on the opposite side of said screw anchor 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 4 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 screw anchor (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).
A cradle as claimed in claim 11, wherein said safety device (17) comprises a shaped plate, hinged on the axis (10a) of the mechanism (7) 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 claims 2 to 12, wherein said housing (8) on an outer edge thereof has an enlargement (16) creating a mechanical interference with the screw anchor (9) in the deformed configuration, to prevent the occurrence of an accidental disengagement of the screw anchor (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 claim 14, 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.