WO2004074520A2

WO2004074520A2 - Machine for folding skins

Info

Publication number: WO2004074520A2
Application number: PCT/FR2004/000247
Authority: WO
Inventors: Jérôme Darragon
Original assignee: Centre Technique Cuir Chaussure Maroquinerie
Priority date: 2003-02-04
Filing date: 2004-02-03
Publication date: 2004-09-02
Also published as: WO2004074520A3; FR2850670B1; FR2850670A1; EP1590490A2

Abstract

The invention relates to a machine for mechanisation of the folding of raw animal skins, comprising, in the longitudinal direction thereof, a succession of conveyors (4, 5, 6, 7) with belts, cables or bands (16), provided with motorised propulsion means. The conveyors (4, 6, 7) are mounted to pivot about transverse axes (8, 12, 13) and connected to means of controlling the upwards pivoting thereof. An other non-pivoting conveyor (5) is transversely divided into several conveyor sections (5a, 5b, 5c, 5d), some (5a, 5b, 5d) of which are mounted to pivot about longitudinal axes (9, 10, 11) and are connected to means for controlling the upwards pivoting thereof. The machine thus permits the longitudinal and transverse folding of skins in the same space and the transport and removal thereof.

Description

Skin folding machine

The present invention relates to a machine for folding skins, in particular a machine performing mechanically the folding of raw animal skins.

The skins of raw animals, coming from slaughterhouses, must be folded in order to group them in piles on pallets, for their direct or indirect shipment to tanneries.

Currently, folding such skins remains an operation carried out manually, on a table or directly on the ground. This operation presents difficulties, because of the dimensions of the skins and their weight, which can reach 70 kg in the case of bull skins. In addition, the manual folding operation requires personnel and takes time.

It should be noted here that, for their dispatch, the skins must be folded several times, both longitudinally and transversely, which complicates the problem of the mechanization of the folding of the skins.

Machines are known for folding laundry items, longitudinally and transversely; however, these machines are not suitable for folding skins - see for example the document FR 2 720 761. In the field of handling skins, machines are known comprising belt or cable or belt conveyors, which are especially used to transport the skins and to stack them, in particular on easels - see for example the patents US 2686673, US 3 156464 and US 3 198 513, or the patent application NL 6907 223. The documents DE 2 059394 and EP 0 198 777 already describe skin folding equipment. However, these devices produce a single fold, and are therefore not designed to produce a succession of longitudinal and transverse folds.

Faced with this state of the art, the present invention aims to provide equipment specially intended for folding raw hides, so as to carry out this folding in a mechanized manner, by operating in the same space both longitudinal and transverse, so as to obtain a complete folding of a skin in a relatively short time.

To this end, the subject of the invention is essentially a machine for folding the skins, more particularly the raw skins, which comprises in its longitudinal direction a succession of conveyors with belts, cables or with belts, provided with motorized drive means, at least one of these conveyors being mounted tilting about a transverse axis, and being associated with motorized means for controlling its tilting upwards, and at least one other of these conveyors being divided transversely into at least two juxtaposed conveyor sections, at least one of which is pivotally mounted about a longitudinal axis, and is associated with motorized means for controlling its tilting upwards.

In a preferred embodiment of the invention, the successive conveyors with belts, cables or belts comprise, from upstream to downstream with reference to the general direction of driving of the skins: a first conveyor mounted tilting about an axis transverse located at its downstream end; a second non-tilting conveyor, but divided transversely into at least two juxtaposed conveyor sections, at least one of which is mounted tilting around a longitudinal axis; a third conveyor mounted tilting about a transverse axis located at its upstream end; and a fourth conveyor mounted tilting about a transverse axis located at its upstream end.

The second conveyor is advantageously divided transversely into four juxtaposed conveyor sections comprising successively: a lateral conveyor section mounted tilting about a longitudinal axis, an intermediate conveyor section mounted tilting around a longitudinal axis, another intermediate conveyor section non-tilting, and a section of lateral conveyor opposite to the first and also mounted tilting around a longitudinal axis. Preferably, this machine uses conveyors with belts, cables or endless belts passing over smooth drive and return cylinders, means external to said cylinders being provided for positioning and guiding the belts, cables or belts.

The drive means of the belt, cable or belt conveyors, as well as the tilting control means of these conveyors, or of some of their sections, advantageously comprise electric geared motors, which can be associated with chain drives .

A skin folding machine is thus obtained, capable of folding a skin several times, longitudinally and transversely, in a fully automatic manner. This machine has the following advantages: The different conveyors of the machine ensure, in the same space, the longitudinal positioning and positioning of the skins to be folded, the longitudinal and transverse folding of these skins, and the evacuation of the folded skins, l advancing and folding of the skins being operated by the same elements, namely the conveyors or the sections of conveyors, some of which are tiltable. Thus, the invention provides a particularly simple, compact and economical technical solution.

The use of conveyors with belts, cables or belts, passing on smooth cylinders, makes these conveyors easy to clean, by eliminating in particular on the cylinders all grooves in which could accumulate waste or salt (the skins " raw "being in fact already salted in slaughterhouses).

The machine performs complete folding of a skin in a short cycle time, of the order of ten seconds, and with great folding precision, thereby combining high efficiency and high quality of operation and result. Each folded skin is also perfectly positioned, in particular on the non-tilting intermediate conveyor section, which facilitates its evacuation on a conveyor located downstream of the machine.

The number of conveyors and sections of tilting conveyors allows multiple longitudinal and transverse folding of the same skin, making the machine effective even for large skins, this machine can however be used without exploiting the tilting of all the conveyors, for smaller skins.

The machine's structure is robust, and allows it to withstand both the more or less sudden tilting movements of its conveyors, as well as severe operating conditions (presence of salt). The electric motorization of all the movements of the machine, whether it is the drive of the conveyors or their tilting, allows easy control and programming of these movements. In particular, for the tilting of the conveyors, a rapid movement can be obtained (in a time of the order of one second), by the intervention of electronic speed variators, such as frequency variators. The invention will be better understood with the aid of the description which follows, with reference to the appended schematic drawing representing, by way of example, an embodiment of this skin folding machine:

Figure 1 is an overall perspective view of a machine according to the present invention;

Figure 2 is a cross-sectional view of this machine, along ll-ll of Figure 1;

Figures 3 to 13 are diagrams illustrating the successive phases of the operating cycle of the machine of Figures 1 and 2. The skin folding machine, visible in Figure 1, is arranged between a conveyor 2 for feeding skins to fold , along an arrow F, and a conveyor 3 for evacuating folded skins. This folding machine itself comprises a succession of conveyors, which in their basic position are all in the same horizontal plane, like a table. From upstream to downstream, by reference to the direction of advance of the skins (arrow

F), the machine comprises: a first conveyor 4, a second conveyor 5, a third conveyor 6 and a fourth conveyor 7, all of large width equivalent to that of the feed conveyor 2.

The first conveyor 4, which is here divided transversely into three juxtaposed conveyor sections 4a, 4b and 4c, is mounted tilting around a transverse axis 8 located at its downstream end.

The second conveyor 5 is divided transversely into four juxtaposed conveyor sections 5a, 5b, 5c and 5d. In detail, a distinction is made here: - a first conveyor section 5a situated in the lateral position, mounted tilting about a longitudinal axis 9 (on its "inside" side);

- A second conveyor section 5b located in the intermediate position, mounted to tilt about a longitudinal axis 10 (on its "inside" side); - A third conveyor section 5c located in the intermediate position, and not tilting, in other words fixed;

- A fourth section of conveyor 5d located in the lateral position, opposite the first, and mounted tilting around a longitudinal axis 11 (on its "inside" side). (See also Figure 2) The third conveyor 6, which is here divided transversely into three juxtaposed conveyor sections 6a, 6b and 6c, is pivotally mounted around a transverse axis 12 located at its upstream end.

Likewise, the fourth conveyor 7 is here divided transversely into three juxtaposed conveyor sections 7a, 7b and 7c and it is mounted tilting around a transverse axis 13 located at its upstream end.

The discharge conveyor 3, of small width, is located in correspondence with the third "fixed" (non-tilting) section 5c of the second conveyor 5, itself non-tilting. With particular reference to FIG. 1, each of the sections of conveyors, such as 4a, 4b, 4c, 5a, 5b, etc. comprises two smooth cylinders 14 and 15, one of drive and the other of return, on which pass a series of belts or endless cables 16, kept spaced from each other at constant intervals by guide bars (not shown). Each endless belt 16 is advantageously of round section, and reinforced so as to have great mechanical resistance. Each conveyor section 4a, 4b, 4c, 5a, 5b, ... etc. has a frame 17, mounted either tilting or fixed.

The different conveyors 4, 5, 6 and 7 (therefore their sections of conveyors previously identified) are driven by electric geared motors and by chain transmissions, so as to ensure the advancement and positioning of each skin to be folded, then the evacuation of this folded skin. Other motorized means control: the tilting of the first conveyor 4 around the transverse axis 8, the tilting of the conveyor sections 5a, 5b and 5d around the respective longitudinal axes 9,

10 and 11, the tilting of the third conveyor 6 around the transverse axis

12, and the tilting of the fourth conveyor 7 around the transverse axis 13.

Thanks to an appropriate sequence of drive and tilting control of these conveyors and conveyor sections, the overall operation of the machine is carried out as follows, illustrated by the diagrams of FIGS. 3 to 13:

At the start of a cycle, a skin P to be folded arrives via the supply conveyor 2 (see FIG. 3), and it is transferred to the machine of which all the conveyors 4, 5, 6 and 7, kept horizontal, are driven simultaneously and synchronously. The skin P thus advances, until it occupies a position centered on the machine (see FIG. 4). After stopping the conveyors, the fourth conveyor 7 is tilted upwards, and immediately after the first conveyor 4 is also tilted upwards. The skin P is thus folded twice in the transverse direction (see FIG. 5), the term "transverse" being used here with reference to the general direction of advance (arrow F) of the skins P.

The two conveyors 4 and 7 being brought back into their horizontal base plane, the skin P already folded twice in the transverse direction now rests only on the second conveyor 5 and on the third conveyor 6 (see FIG. 6). Then, the third conveyor 6 is tilted upwards, so as to fold the skin P again in the transverse direction (see FIG. 7). The third conveyor 6 being brought back into its horizontal base plane, the skin P three times folded transversely only rests on the second conveyor 5 (see FIG. 8). Then, in the second conveyor 5, the two lateral sections

5a and 5d are tilted upwards so as to fold the skin P twice longitudinally (see FIG. 9), the term "longitudinally" being used here to characterize a direction which corresponds to the general direction of advance (arrow F) of the skins P. After having brought the two sections of conveyor 5a and 5d back into their basic plane, the skin P folded transversely and longitudinally only rests on the two intermediate sections 5b and 5c of the second conveyor 5 (see FIG. 10).

The second intermediate section 5b of the second conveyor 5 is then tilted upwards, so as to fold the skin P a third time longitudinally (see FIG. 11). After the return of the conveyor section 5b in its basic plane, the skin P fully folded, longitudinally and transversely, only rests on the third section (fixed intermediate section) 5c of the second conveyor 5 (see FIG. 12). Finally, the various conveyors 4, 5, 6 and 7 are again driven in synchronism, so as to advance the folded skin P, with a view to evacuating it, the folded skin P being finally taken up by the evacuation conveyor 3 folded skins (see Figure 13).

A new skin to be folded can then be brought to the machine, for a new folding cycle identical to the previous one. The different tilting movements of the conveyors 4, 6, 7 and of the conveyor sections 5a, 5b, 5d, which occur during the operating cycle, are secured in particular by light barriers.

In the operating example previously described, and illustrated by FIGS. 3 to 13, the skin P is folded three times longitudinally and also three times transversely, so that in the final folded state, as it is removed, this folded skin P has sixteen superimposed thicknesses. The folded skin can rest on a reduced horizontal surface, for example a rectangular surface with a length of 60 cm and a width of 55 cm, the skins thus folded can be grouped in four stacks on a pallet of a length 120 cm and a width of 110 cm.

The operating cycle, previously described, can be adapted according to the shapes and dimensions of the skins to be folded. In particular, in the case of a "shorter" skin, one of the transverse folds can be eliminated, by eliminating the tilting of one of the extreme conveyors, namely the first conveyor 4 or the fourth conveyor 7.

Optionally, and not shown, a linear camera located upstream of the folding machine, and associated with calculation means, can perform automatic centering of each skin P on the machine, which makes it possible to automatically adapt the folding cycle to the dimensions of the skins, and to eliminate the need for a person for this centering task.

In another variant not illustrated, the positions of the conveyors 5 and 6 are reversed, in other words the "fixed" conveyor (on which the folded skin is finally found) takes the place of the conveyor 6 of the embodiment shown in the drawing. Thus, the position of the folded skin P to be evacuated is brought closer to the downstream end of the machine, therefore of the conveyor 3 for evacuating the folded skins.

One would not depart from the scope of the invention, as defined in the appended claims, by detailed modifications of the various conveyors, which may also be cables or belts, or their drive means. The applications of the invention are also diverse, and may include the folding of skins not raw but already treated.

Claims

1. Machine for folding the skins, more particularly a machine performing mechanically the longitudinal and transverse folding of the raw skins, characterized in that it comprises in its longitudinal direction a succession of conveyors (4, 5, 6, 7) with belts , with cables or belts (16), provided with motorized drive means, at least one (4, 6, 7) of the conveyors being mounted tilting about a transverse axis (8, 12, 13), and being associated with motorized means for controlling its tilting upwards, and at least one other (5) of these conveyors being divided transversely into at least two sections of conveyor (5a, 5b, 5c, 5d) juxtaposed, including at least one (5a, 5b, 5d) is mounted tilting about a longitudinal axis (9, 10, 11), and is associated with motorized means for controlling its tilting upwards.

2. Skin folding machine according to claim 1, characterized in that the successive conveyor belts, cables or belts (16) comprise, from upstream to downstream by reference to the general direction of drive (F) of the skins (P): a first conveyor (4) mounted tilting about a transverse axis (8) located at its downstream end; a second non-tilting conveyor (5), but divided transversely into at least two juxtaposed conveyor sections (5a, 5b, 5c, 5d), at least one of which (5a, 5b, 5d) is pivotally mounted around a longitudinal axis (9, 10, 11); a third conveyor (6) mounted tilting about a transverse axis (12) located at its upstream end; and a fourth conveyor (7) mounted tilting about a transverse axis (13) located at its upstream end.

3. Skin folding machine according to claim 2, characterized in that the second conveyor (5) is divided transversely into four sections of conveyor (5a, 5b, 5c, 5d) juxtaposed, successively comprising: a first section of lateral conveyor (5a) mounted tilting around a longitudinal axis (9), an intermediate conveyor section (5b) mounted tilting around a longitudinal axis (10), another non-tilting intermediate conveyor section (5c), and a section lateral conveyor (5d) opposite the first (5a) and also mounted tilting about a longitudinal axis (11).

4. Skin folding machine according to any one of claims 1 to 3, characterized in that the aforementioned conveyors are conveyors (4, 5, 6, 7) with belts, cables or endless belts (16) passing over smooth cylinders (14, 15) for driving and returning, means external to said cylinders (14, 15) being provided for positioning and guiding the belts, cables or bands (16).

5. Skin folding machine according to any one of claims 1 to 4, characterized in that the drive means of the conveyors (4, 5, 6, 7) with belts, cables or belts (16), as well as the tilting control means of these conveyors (4, 6, 7) or of some of their sections (5a, 5b, 5d), include electric geared motors, which can be associated with chain transmissions.

6. Skin folding machine according to claim 5, characterized in that the tilting movements of the conveyors (4, 6, 7) and of the conveyor sections (5a, 5b, 5d) are secured by light barriers.

7. Skin folding machine according to any one of claims 1 to 6, characterized in that it is arranged between a conveyor (2) for feeding the skins to fold, and a conveyor (3) for evacuating folded skins, the conveyors (4, 5, 6, 7) of the machine being of large width equivalent to that of the supply conveyor (2), while the evacuation conveyor (3) is of small width and located in correspondence with the non-tilting section (5c) of the non-tilting conveyor (5).