EP2607257A1

EP2607257A1 - Rapidly reconfigurable pallet for safe transport of stacks of sheet metal blanks

Info

Publication number: EP2607257A1
Application number: EP12198316.7A
Authority: EP
Inventors: Gianfranco Marchetti; Paolo Lavezzato
Original assignee: Fiat Group Automobiles SpA
Current assignee: FCA Italy SpA
Priority date: 2011-12-23
Filing date: 2012-12-20
Publication date: 2013-06-26
Anticipated expiration: 2032-12-20
Also published as: ITTO20111198A1; EP2607257B1

Abstract

A rapidly reconfigurable pallet for safe transport of stacks of sheet-metal blanks comprises a base structure (2) with a plurality of cross members (T) that define a resting surface for the stack of sheet-metal blanks that is raised with respect to the top surface of the base structure (2). Associated to the base structure are auxiliary longitudinal beams (S), the top walls of which are in a lower position with respect to the aforesaid resting surface defined by the cross members (T). Said cross members (T) and said auxiliary longitudinal beams (S) have respective arrays of holes (t, s) of a different shape for receiving first and second posts (P1, P2) that have lengths different from one another and bottom portions with sections different from one another, corresponding to the shapes of the respective receiving holes. Associated to some of the aforesaid posts are brackets (B), which are height-adjustable, designed to press on the top surface of the stack to keep it vertical.

Description

The present invention relates to a pallet for transporting in safety stacks of sheet-metal blanks. Pallets of this type are used, for example in the automotive industry, for conveying stacks of sheet-metal blanks from the workstation at output from the shearing machine to a workstation at input to a press that is to pick up in succession the sheet-metal blanks and to subject them to a pressing operation, for producing components of motor-vehicle structures.
There are already known (see, for example, US-A-5 809 906 ), pallets of the type referred to above, which comprise:

a base structure, including a front beam and a rear beam connected at their ends by two side beams;
a plurality of cross members that connect said front and rear beams to one another and that have respective top plane walls, defining a common horizontal resting surface for a stack of sheet-metal blanks and each having an orderly array of first holes for receiving first posts for containing the stack; and
a plurality of first posts with bottom ends that can be inserted in respective receiving holes selected in the arrays of the aforesaid first holes of said cross members, for containing said stack.

The function of the aforesaid posts is to prevent any instability of the stack of sheet-metal blanks during transport, in particular in the eventuality of any accidental impact of the transport vehicle against any obstacles present in the workshop. In said known solutions, containment in a vertical direction of the stack is normally obtained with the aid of conventional straps with which the stack is strapped.
The object of the present invention is to provide a pallet of the type referred to above that will guarantee perfect stability of the stack during transport, that will be reconfigurable with operations that are extremely simple and fast so as to be adapted to the dimensions and shape in top plan view of the stack of sheet-metal blanks, and that will moreover enable the stack to be secured also in the vertical direction with operations that are equally simple and fast.
With a view to achieving the aforesaid object, the subject of the invention is a pallet, which presents the characteristics that have already been referred to at the start of the present description and is moreover characterized in that:

the aforesaid cross members defining the resting surface for the stack of sheet-metal blanks are fixed on the aforesaid front and rear beams of the base structure so that the aforesaid resting surface is raised with respect to the top surface of the base structure; and
the base structure further comprises auxiliary longitudinal beams that extend parallel to said front and rear beams and have respective top plane walls that lie in a plane lower than the resting surface of the stack defined by the aforesaid cross members and that each have an orderly array of second holes for receiving second posts for containing the stack of sheet-metal blanks,

characterized in that

Thanks to the aforesaid characteristics, the pallet according to the invention presents a series of important advantages. First of all, the provision of receiving holes for the posts for containing the stack, both on the aforesaid cross members that connect together the front and rear beams of the base structure and on the aforesaid auxiliary longitudinal beams, enables installation of a plurality of posts designed to contain the stack of sheet-metal blanks both with respect to any movement orthogonal to said front and rear beams (i.e., in the direction of movement of the vehicle for transporting the pallet) and in the direction orthogonal to said side beams (i.e., in a direction transverse to the direction of advance of the transport vehicle). The provision of first holes and of second holes on surfaces set at different levels enables on the one hand use of a structure that is simple and inexpensive to produce and on the other hand gives rise to the use of containing posts which, since they must have their top ends set substantially at the same height when they are in operation, have lengths different from one another. However, this does not entail any particular complication or waste of time for the operator since the two different types of posts are readily distinguishable from one another on account of the different shape of the cross section (at least at their bottom ends), and their location of installation is likewise immediately identifiable thanks to the different shape of the receiving holes provided on the aforesaid cross members and on the aforesaid auxiliary longitudinal beams.
Finally, the stack of sheet-metal blanks, once received on the cross members of the pallet, and withheld on its periphery by positioning of the first and second posts, can be blocked also vertically with extremely simple and fast operations given that there may be associated to two or more of the aforesaid first posts or the aforesaid second posts height-adjustable brackets designed to press on the top surface of the stack. This arrangement is, in particular, used when a stack of sheet-metal blanks is not to be moved just for a short stretch within an industrial works, but, for example is to be sent from one industrial plant to another.
Moreover, in a preferred embodiment, the aforesaid auxiliary longitudinal beams (S) each have a number of orderly rows of holes (s), the holes of each row being set at a distance from one another according to a constant pitch, for example in the region of 10 mm, and being staggered longitudinally by half a pitch with respect to the holes of an adjacent row. In this way, it is ensured that for any conformation of the sheet-metal blanks of the stack it is always possible to have available holes for insertion of posts in a position sufficiently close to the edges of the sheet-metal blanks.
Further characteristics and advantages of the invention will emerge from the ensuing description, with reference to the annexed drawings, which are provided purely by way of non-limiting example and in which:

Figure 1 is a perspective view of a preferred embodiment of the pallet according to the invention;
Figure 2 is a perspective view similar to that of Figure 1, which shows the pallet with a stack of sheet-metal blanks set on top of it;
Figure 3 is a plan view corresponding to that of Figure 2;
Figures 4 and 5 are views in elevation according to the arrows IV and V of Figure 3; and
Figures 6 and 7 are views in elevation that show a number of pallets stacked on top of one another respectively in a condition where a stack of sheet-metal blanks is loaded on each pallet and in an unloaded condition of each pallet.

With reference to the drawings, number 1 designates as a whole a pallet, comprising a base structure designated as a whole by the reference number 2. The main components of the base structure 2 are a longitudinal front beam 3 (which, in the example of embodiment illustrated herein, is defined by three portions of beam 3a, 3b, 3c), a longitudinal rear beam 4 (which, in the example illustrated, is also defined by three portions of beam 4a, 4b, 4c), and two side beams 5 (just one of which is visible in Figure 1), each defined, in the case of the example illustrated, by portions of beam 5a, 5b, 5c.
Once again in the case of the specific example illustrated, the base structure further includes two hollow intermediate beams F, which connect the front and rear beams 3 an 4 together in positions symmetrically set at the two sides of the median vertical plane of the pallet. Once again in the case of the specific example illustrated, the base structure 2 finally comprises two further intermediate longitudinal beams L, which extend between the two side beams 5, as well as a central plate A, which extends longitudinally between the two cross members F and bears a pair of holes with tapered wall, converging upwards, that are to engage on corresponding locating pins provided in the workstation at input to a press, for locating the pallet in a precise position in said workstation and enabling automatic pick-up by the press of the sheet-metal blanks stacked on the pallet.
According to the invention, fixed on the base structure 2 is a plurality of cross members T that connect the front and rear beams 3 and 4 together. The cross members T have respective top plane walls defining a common horizontal resting surface for the stack of sheet-metal blanks. As may be seen in the figures, the cross members T are fixed on the front and rear beams 3 and 4 (as well as on the intermediate beams L and F) so that the resting surface of the stack of sheet-metal blanks is raised with respect to the plane of the top surfaces of the elements 3, 4, 5, L and F defining the top surface of the base structure 2.
Each of the cross members T bears on its top wall an orderly array of holes t for receiving the bottom ends of posts P1 for containing the stack of sheet-metal blanks.
In the example illustrated, each cross member T contains a single row of holes t, and the aforesaid holes are square in shape. Consequently, the posts P1 that may be received in the holes t have a square cross section, at least in their bottom end portion.
With reference once again to the drawings, the two intermediate cross members F are hollow cross members, defining cavities C for receiving the forks of the vehicle that is to transport the pallet.
According to the invention, the base structure 2 further comprises two sets (in the specific case two pairs) of intermediate auxiliary beams S, each of which extends between one of the side beams 5 and one of the beams of the intermediate cross members F.
The auxiliary longitudinal beams S have plane top walls of the elements 3, 4, 5, F, L that define the base structure 2. Moreover, the top walls of the auxiliary longitudinal beams S have an orderly array of holes s (in the example illustrated, three parallel rows of holes longitudinally staggered with respect to one another) for receiving the bottom ends of containment posts P2. As may be seen clearly in Figure 3, the containment posts P1 are to engage the two longitudinal edges of the stack of sheet-metal blanks, for preventing any movement of the stack in the vertical direction of Figure 3, i.e., in the direction of advance of the vehicle that transports the pallet, whilst the posts P2 are to engage the two opposite sides of the stack, for preventing any movement of the latter in a direction transverse to the direction of advance of the transport vehicle. The aforesaid auxiliary longitudinal beams (S) each have a number of orderly rows of holes. The holes of each row are set at a distance from one another according to a constant pitch, for example in the region of 10 mm, and are staggered longitudinally by half a pitch with respect to the holes of an adjacent row. In this way, it is ensured that for any conformation of the sheet-metal blanks of the stack it is always possible to have available holes for insertion of posts in a position sufficiently close to the edges of the sheet-metal blanks.
As may moreover be seen in Figures 4 and 5, the posts P1, P2, once installed, have their top ends substantially at the same level so as to enable stacking in said condition of a number of pallets, as illustrated in Figure 6. As a consequence of the fact that the top surfaces of the cross members T are raised with respect to the top surfaces of the auxiliary beams S, the posts P1, P2 are hence of different length. To facilitate the operator in distinguishing and installing the two different types of posts, the shape of the holes s has been chosen different from the shape of the holes t (in the example illustrated, the holes t are square and the holes s are round, as mentioned above). Consequently, whereas the posts P1 have a square cross section, at least at their bottom ends, the posts P2 have a round cross section, at least at their bottom ends.
With reference once again to Figure 1, in the central median plane of the pallet, no cross member T is provided, but simply a vertical plate N, which contributes to supporting the stack of sheet-metal blanks resting on the pallet.
Once again with reference to Figure 3, in the example illustrated three posts P1 are positioned on each of the front and rear sides of the stack of sheet-metal blanks, and two posts P2 on each of the two sides of the stack.
Once the stack of sheet-metal blanks has been received on the pallet, in particular, on the cross members T, the posts P1 and P2 are positioned selecting the holes t and s most suitable for enabling positioning of each post in contact with and immediately adjacent to the respective side of the stack. The distancing between two adjacent holes t and s of one and the same row is chosen sufficiently small (for example, in the region of 10 mm) for guaranteeing an adequate positioning of the posts whatever the conformation of the sheet-metal blanks.
Once the posts P1, P2 have been positioned, the stack can be withheld moreover also axially by means of two or more brackets B that are carried by height-adjustable supports mounted on some of the posts P1 and/or P2 (the example illustrated shows two pairs of brackets B carried on as many pairs of posts P1; see, in particular, Figures 3, 4, and 5). Said arrangement is, in particular, used when a stack of sheet-metal blanks is not to be moved just for a short stretch within an industrial works, but for example has instead to be sent from one industrial plant to another.
For emergency, the top walls of the intermediate cross members F and of the intermediate longitudinal beams L are provided in any case with guide channels z in which conventional straps for strapping of the stack of sheet-metal blanks can be made to slide.
Associated to the pallet are supporting columns H of greater length and supporting columns h of smaller length (see Figure 1), each having a bottom end that is to be received in a seat provided on the base structure 2 of the pallet and a top end with a locating pin 10 that is to be received in a corresponding seat made underneath the base structure 2 of another pallet so as to enable stacking of a number of pallets with the stacks of sheet-metal blanks arranged thereon (Figure 6) with the aid of the columns H and stacking of a number of pallets in the unloaded condition (Figure 7) with the aid of the columns h.
As is evident from the foregoing description, the pallet according to the invention presents the advantage of being rapidly reconfigurable according to the shape and dimensions of the stack of sheet-metal blanks. It can be installed with operations that are extremely simple and fast thanks to the possibility of associating different containment posts immediately to different receiving holes. Moreover, transport of the stack of sheet-metal blanks is altogether safe thanks to the provision of the clamping brackets B, which are also extremely easy and fast to use.
Preferably provided within the elements constituting the base structure 2 are one or more housings that can be used as magazine for the posts P1, P2.
Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary widely with respect to what has been described and illustrated herein purely by way of example, without thereby departing from the scope of the present invention.

Claims

A pallet for transporting in safety stacks of sheet-metal blanks, comprising:
- a base structure (2) including a front beam (3) and a rear beam (4) connected at their ends by two side beams (5);

- a plurality of cross members (T) that connect said front and rear beams (3 and 4) to one another and that have respective top plane walls, which define a common horizontal resting surface for a stack of sheet-metal blanks (D) and each of which has an orderly array of first holes (t) for receiving first posts (P1) for containing the stack (D); and

- a plurality of first posts (P1) with bottom ends that can be inserted in respective receiving holes (t) selected in the arrays of first holes (d) of said cross members (T), for containing said stack (D),
said pallet being characterized in that:
- said cross members (T) defining the resting surface of the stack (D) of sheet-metal blanks are fixed on the aforesaid front and rear beams (3 and 4) of the base structure (2) so that said resting surface is raised with respect to the top surface of said base structure (2); and

- said base structure (2) further comprises auxiliary longitudinal beams (S) that extend parallel to said front and rear beams (3 and 4) and that have respective top plane walls, which lie in a plane lower than the resting surface of the stack defined by the aforesaid cross members (T) and each of which has an orderly array of second holes (s) for receiving second posts (P2) for containing the stack (D) of sheet-metal blanks;
said pallet further comprising a plurality of second posts (P2) with bottom ends that can be inserted in respective receiving holes selected in the arrays of second holes (s) of said auxiliary longitudinal beams (S), for containing the sides of the stack (D) of sheet-metal blanks,
wherein said first posts (P1) have a length shorter than that of said second posts (P2) and have their bottom ends with a cross section different from that of the bottom ends of the second posts (P2), said first holes (t) and said second holes (s) having shapes corresponding to those of the cross section of the bottom ends of said first posts (P1) and of said second posts (P2),
it further being possible to associate to two or more of said first posts (P1) or of said second posts (P2) brackets (B) that can be adjusted in height for vertical containment of the stack of sheet-metal blanks and that are designed to press on the top surface of the stack.
The pallet according to Claim 1, characterized in that the aforesaid cross members (T) each have a single row of holes (t).
The pallet according to Claim 1, characterized in that, said auxiliary longitudinal beams (S) each have a number of orderly rows of holes (s), the holes of each row being set at a distance from one another according to a constant pitch, for example in the region of 10 mm, and being staggered longitudinally by half a pitch with respect to the holes of an adjacent row.
The pallet according to Claim 1, characterized in that the holes (t) of the cross members (T) are square and the holes (s) of the auxiliary longitudinal beams (S) are circular.
The pallet according to any one of the preceding claims, characterized in that the base structure has housings used as magazine for the aforesaid first posts and second posts (P1, P2).
The pallet according to any one of the preceding claims, characterized in that it is provided with spacing columns (H, h) having bottom ends that can be connected to the aforesaid base structure (2) and top ends that can be engaged in seats provided under the base structure of another pallet (1).
The pallet according to Claim 6, characterized in that columns (H, h) of two different lengths are provided, which are used for stacking a number of pallets on top of one another respectively in the condition where a stack of sheet-metal blanks is set on each pallet or in the unloaded condition.
The pallet according to any one of the preceding claims, characterized in that the base structure includes two auxiliary cross members (F) set coplanar with the aforesaid front and rear beams (3 and 4), which define cavities (C) for receiving the forks of a vehicle for transporting the pallet.