Device for supplying sheet-like materials.

The present invention relates to a sheet material feeding device, for example cardboard, paper, tin, aluminum sheets, etc.

The present invention applies to such a device designed to distribute such sheets one by one to a treatment or processing station. In such a system, the sheets are stacked on a barred, usually wooden, platform commonly referred to as a pallet.

The present invention relates in particular to a set of means for automatically or almost automatically performing the set of operations of evacuating an empty platform and placing another platform supporting a new stack of sheets without interruption of distribution. of said leaves, or notable disturbance of the process of distributing said leaves.

In a device of the kind defined above, the platform supporting the stack of sheets is placed in an elevator mechanism that lifts the assembly further progressively as the sheets are distributed to compensate for the decrease in stack height. When only a limited number of sheets remain, it is necessary to evacuate the platform and place a new stack supported by another platform. If the disruption of the dispensing process is to be prevented, handrails, commonly known as sabers, are manually slid between the unattached planks of the platform to support the few remaining sheets. These bars are secured with fixed supports and an auxiliary elevator to continue the distribution process. After placing these bars, the platform is lowered and removed. Then a new battery is placed in the elevator mechanism which is raised until the top of the battery reaches the level of the bars or sabers, which are then removed. This manual process involves the mobilization of at least one operator for a not inconsiderable amount of time and requires some dexterity on their part because the maneuvering of the support bars can be detrimental to the products and there is a risk that the sheets will be scratched.

Attempts to automate this process have so far encountered difficulty linked to size deviations and positioning variations of platforms or pallets. Indeed, if the platform is deflected or by means of the stack, the interstices through which said support bars can be applied remain in variable and invisible positions.

The present invention solves this problem and therefore proposes an automatic or semi-automatic feeding device which in particular enables the platforms to be changed more easily and without risk of deteriorating the sheets of material.

In this spirit, the present invention therefore relates essentially to a sheet material feeding device, said sheets being stacked on a meshed platform, of the type comprising an elevator mechanism capable of supporting such a sheet-loaded platform and a mechanism. interim support to support a number of sheets during a platform change, characterized in that said support mechanism comprises a number of bars connected to or being part of respective jacks capable of displacing them in their own longitudinal directions, under the sheets, in the interstices of a said platform and said jacks are supported by respective movable equipment arranged to place said bars in front of said respective interstices.

According to another advantageous feature of the present invention, each support bar, in association with its drive jack, constitutes an explorer member displaced by movable equipment along the platform, for an automatic search of one of the mentioned interstices.

The present invention will be better understood and further advantages will appear more clearly in the following description of a possible embodiment of a device according to its principle, given by way of example only and made with reference to the drawings. annexes whose figures represent:

Fig. 1 is a plan overview of a sheet feed device according to the present invention;

Fig. 2 is a detail view showing a support bar and its drive jack; and

Fig. 3 is a schematic principle illustrating the command of one of the mobile devices of the device.

Referring to the drawings, the sheet feed device 11 comprises an elevator mechanism of which only one base 12 has been shown, which is required to move vertically (by any suitable mechanical means), a fixed stop ( 13) and a movable stop (14), both perpendicular to the direction of distribution (indicated by the arrow (F)) of the sheets (15) and two lateral support plates (17) and (18) parallel to said direction of distribution and whose positioning is adjustable according to the shape of the sheets ( 15). Dispensing means, not shown, are arranged at the top of the device to remove the sheets one by one and pull them out in the direction of the arrow (F).

The base (12) receives a stack of sheets (15); This stack is classically placed on a wooden platform (21), commonly known as a pallet. Such platforms, often rudimentary in construction, with unjoined planks, naturally comprise interstices (22) which are used for the placement of the usual support bars mentioned above. However, the dimensions of the platforms are neither precise nor standard, so that the positions of said interstices within the square or rectangular frame bounded by the stops (13) and (14) and the side support plates (17) and (18) ), vary from one line to the other. On the other hand, the platform is sometimes cross-linked (as shown) with respect to the sheet stack itself, which accentuates the problem with respect to the situation of the interstices (22).

The feeding device (11) is further equipped with an interim support mechanism (25) to support a number of sheets during a platform shift. According to the present invention, this mechanism comprises a number of bars (26) (four in the example shown) connected to or forming part of pneumatic jacks (27). The mounting is such that each bar can move in its own longitudinal direction under the remaining sheets, fitting between the abovementioned interstices (22). In addition, the jacks (27) are supported by respective movable equipment (29) arranged to place the bars in front of these gaps (22). In the illustrated example, each jack 27 is arranged parallel to the corresponding bar 26 perpendicular to the dispensing direction F to reduce the space occupied by the apparatus on the sides. One end of the bar is thus coupled to the jack bar 27a. The free end (30) of the bar (26) performs the function of an operating organ capable of contacting one side of a platform (21) during a displacement of the corresponding movable equipment (29). To this end, this end 30 may be rounded as shown or provided with a rolling roller. In addition, each bar 26 is provided with a number of rollers 31 arranged to contact the sheets and thus to avoid scratching. As can be seen from fig. 2, the rollers 31 are mounted along the bar 26 passing alternately up and down. Each movable equipment, on which a jack (27) is mounted, consists essentially of a pneumatic jack (35) fixed by means of a support (36) to one of the two side support plates (17) and (18). The elongation of this jack 35 thus conditions the position of the assembly consisting of the bar 26 and the jack 27 along one side of the stack. The exploration member end 30 of each bar 26 can thus move along a certain path while in contact with the edge of a platform 21 when it reaches the level. of the bars (26)] are provided with drive fluid supply means to apply to the jack (27) a low pressure during the displacement of the movable equipment, i.e. during a portion of the corresponding jack stroke (35), and a high pressure at the end of an exploration phase. These drive fluid feed means are illustrated in FIG. 3. The end of an scanning phase is determined by sensing means (38) sensitive to the stroke of the jack (27). In the specifically described example, the jack 27 is fed by one or two of two compressed air sources, a low pressure source (BP) and a high pressure source (HP), via a three-way electric valve. 40 (40) controlled by an electromechanical control unit (41) or other whose design is within the skill of the art. The sensing means (38) comprises, for example, a cam (42) whose position is representative of the longitudinal displacement of the bar (26), and an operating member (45), for example a simple electromechanical contactor, positioned to be cam driven and electrically connected to control the control unit (41). The outlet of the latter is also connected to the control inlet of an electric valve (46) which controls the isolation of the jack (35) from its control pressure and its simultaneous outdoor connection. It is therefore understood that the sensing means 38 are combined with connected pneumatic switching means 40,41 to supply the jack 27 at low or high pressure. The pressure switching takes place as soon as the bar 26 has engaged during the scan to a predetermined distance in an interstitium of a platform. Furthermore, it is seen that, thanks to the connection between the control unit (41) and the electric valve (46), the mobile equipment is controlled by or operates synchronously with the pneumatic switching means to stop the jack. (35) displacement of the assembly consisting of the jack (27) and the bar (26) substantially simultaneously with the inlet of the high pressure in the jack (27).

At the beginning of each platform change cycle, the jacks (35) set starting positions for the bars (26), these positions being closest to the fixed and movable stops (13) and (14). The starting position is fixed for movable equipment located on the fixed anvil side (13) and floating depending on the shape of the sheets, for movable equipment located on the movable anvil side (14). In order to do so, each jack (35) situated on the side of the movable stop comprises two opposing rods, one supporting the jack (27) and the other forming the reference exploration member (48) which contacts the movable stop (14). ). The set is completed by four retractable fingers (49) which open in the vicinity of the leaf edges. Two opposite fingers are provided arranged in the direction of the distribution axis and two others in a perpendicular direction between the bars (26).

The operation is as follows:

When the base (12) has reached a certain height and the platform (which contains only a small amount of leaves) is at the height of the bars (26), the low pressure in the jacks (27) is allowed at the same time as the jacks (35) are fed to begin scanning the edges of the platform at the different ends (30) of the bars (26). Each bar thus ends up finding an interstice (22) and fitting into it. When a bar is sufficiently seated in the gap, the corresponding cam 42 drives the contactor 45, which successively controls the pressure increase in the jack 27 and the freezing of the jack 35. The bar 26 may then fit the interstice as much as possible. When the four bars are engaged, the sheets remaining on the platform are supported and the base (12) can be lowered with said empty platform. The latter is then removed and replaced with a new stack, supported by another platform. The base is raised again until the top of the stack is again at the level of the support bars (26). The bars are then removed by actuation of the jacks 27 so that the last sheets of the previous stack will rest on the new stack. The distribution process is thus not practically disturbed.