EP0004248A1 - Method and device for forming batches of biscuits in stacks of a predetermined length - Google Patents

Abstract

A method and a device making it possible to form batches of fragile, flat objects in stacks of a predetermined length, which objects are arranged edgeways in joined rows (1). These stacks of objects are intended to be packaged in a subsequent operation. The device consists essentially of a set of stops (5,9) and of a transverse pusher (6), which is capable of pushing, over a lateral area, the objects selected to form the desired stack without breaking them. The invention will mainly be employed in the packing of biscuits and particularly fragile and coarse objects whose dimensions are poorly defined. <IMAGE>

Description

The present invention relates to a method and a device for grouping into stacks of determined dimensions objects, which, like rusks, have the distinction of being flat, fragile, rough and having shapes and dimensions defined with poor tolerances. , especially the thickness.

Rusks are made from sandwich loaves cut by sets of parallel blades working automatically. These sets of blades cut the same number of slices from a determined length of bread, but the spacing between two neighboring blades can differ without great inconvenience.

A thinner slice will be offset by its larger neighbor. Taking into account the subsequent treatments bringing each slice to the rusk state, the differences in apparent thickness between neighboring slices can reach more than 5 7. However, in practice, the differences compensate for each other and, when the rusks in stacks of fifteen, we find that the lengths of similar stacks placed side by side generally remain less than 2% and that packaging in standard packages is very possible.

At the end of manufacture, rusks or objects of the same type, are generally presented in contiguous rows on a conveyor such as a conveyor belt or a slide. The objects are arranged on the field perpendicular to the axis of the row. If we then want to select in the row a certain number of objects to constitute a pile of determined length, we realize that we cannot do it by pushing the objects laterally from the row lying on the corresponding length. Most often, the last of the objects selected from the head of the row and the first of those remaining in the row do not slide relative to each other, but break due to their great, fragile, unless you take special precautions.

In addition, the roughness of the objects allows them to remain glued to each other in positions not exactly perpendicular to the plane of the conveyor, but inclined by several degrees relative to the perpendicular. The stack that one would like to separate from the objects arranged in a row occupies not a rectangular volume, but a parallelepiped whose front and rear faces on the conveyor are tilted in one direction or the other. The total length of a stack on the conveyor is thus poorly defined. It must be defined by its median length along the axis of the stack.

Because of these particularities, the grouping of rusks in regular stacks, ready for packaging, has so far been done by hand.

Automatic devices for grouping rusks in stacks are known, such as that described in French patent 2,212,811. However, the fact that the crackers are most often in an inclined position in the supply row means that they have to be taken one by one by a suction cup device. Such automatic devices are complicated and bulky, breakage of rusks is frequent. These devices are practically not used.

Thus, the object of the present invention is a method and said ^p o-operative part relatively simple for a group of such flat objects, brittle and rough, in horizontal length determined batteries (L), this powered from said objects under form of contiguous rows where they are arranged transversely in planes substantially perpendicular to the axis of the row. The average thickness of said objects is noted below (e).

The method consists in first immobilizing the row supplied by the conveyor against a fixed transverse stop of small thickness, ie of the order of 1 / 10th of the height of the row of objects. It is arranged in a plane passing through the axis of the row and parallel to the base plane of the conveyor. The small thickness of the stop and its position in an axial plane parallel to that of the conveyor avoids any asymmetrical force tending to straighten the inclined objects which could cause the said objects to break.

The length of the stack formed by the first objects can be measured upstream of the fixed stop along an axial plane. This eliminates, to a large extent, the error due to the tilting of the objects.

In a second step, using a lateral pusher, the objects intended to form the first stack of length (L) are pushed onto a lateral area. To operate in the best conditions, to have efforts on the objects as symmetrical as possible, as well as to define as well as possible the length of the pile by ignoring its inclination, one must operate in an axial plane of the row with a push button. small thickness, that is to say a thickness of the same order as that of the stop. The pusher is placed immediately upstream of the stop and moves parallel to the base plane of the conveyor in the same median plane as that already defined by

the fixed stop. This plane must be between 1/3 and 1/2 of the height of the row of objects:

The active part of the pusher seen in plan has an L shape. The large branch of the active part has a length (L - e). It moves while remaining parallel to the axis of the row and constitutes the pusher itself. The small branch, hereinafter called "heel" is perpendicular to the large. It extends transversely the front edge of the pusher itself, in the direction opposite to the lateral area, that is to say towards the outside of the row of objects. Its length is at least equal to the width of the objects in the row. The heel and the pusher itself have the same thickness. Thus, when the pusher moves laterally, it remains constantly in the plane defined by the fixed stop.

As the objects selected at the end of the row are pushed back onto the lateral area, the heel takes the place of the last object pushed back from the fixed stop and maintain the first of the remaining objects in the substantially vertical position. row.

When the pusher is at the end of its travel, it has completely crossed the width of the row and pushed transversely over the lateral area of the objects over a length of (L - e) making the stack of the requested length.

The first object remaining in the row is immobilized by the heel which acts as a stop. All the forces are exerted axially on the objects; the risk of breakage is minimal.

Preferably, to reduce the friction between the last of the moved objects and the first remaining in place in the row, the conveyor is stopped while the objects are pushed transversely by the pusher.

A movable U-shaped stop has its two horizontal branches oriented towards the crackers of the feed row. These two branches frame the fixed stop and the heel as closely as possible in the axial plane perpendicular to the base plane of the conveyor. The branches of this movable stop, which were previously erased at the rear of the fixed stop, advance on either side of the fixed stop to the level of the heel. The ends of the two U-shaped arms even extend a little beyond the heel, pushing back the first object remaining on the supply row by a few millimeters. This U-shaped movable stopper thus frees the heel from the contact of the crackers and allows the pusher and its heel to return to their initial position.

The transporter is then restarted and the movable stop moves back at a speed at most equal to that of the transporter, allowing objects to advance to the fixed stop, while keeping them on the field.

A new grouping operation on the lateral area of a stack of objects of appreciably long (L - e) is possible.

It can be seen that the fixed stop, the pusher and its heel all having a small thickness and being arranged in a median plane with respect to the objects, the variations in length due to the inclination of the objects are largely eliminated. The length of the stack is appreciated substantially along its axis, which greatly reduces the possible error as well as possible jamming against moving parts.

To speed up the flow of the device, the lateral recipe area batteries can be an elevator tray. Two devices for grouping stacked objects can be placed on either side of the tray and form two parallel stacks on the same tray. The tray, after loading, goes up or down to a different level where the two formed stacks can be recovery for packaging.

The invention will be better understood from the description below of a particular embodiment and the examination of the corresponding drawings.

• FIG. 1 represents a cross-section along the device for grouping into stacks from rusks arranged transversely in contiguous rows on a conveyor. This sectional view corresponds to the plan view No. 3.
• Figure 2 shows a plan view of the same device.
• FIG. 3 represents, in plan, the same device while the lateral pusher is at mid-stroke and selects a first series of crackers pushed back laterally on the reception area to form the first stack.
• FIG. 4 represents, in plan, the same device while the lateral pusher is at the bottom of the travel and the movable U-shaped stop has advanced against the objects remaining in the row to take over from the transverse heel while holding in place the objects remaining in the initial row.
• FIG. 5 represents, in plan, the same device while the lateral pusher has returned to its initial position by releasing the extension of the row of objects. The movable stop is at mid-course during its return to the initial position, the crackers advance while being held by the movable stop.

In FIGS. 1 and 2, we can distinguish rusks of thickness (e) supplied in contiguous rows (1) on a conveyor constituted by a conveyor belt (2) extended by a slide (3). These rusks are most often slightly inclined forward or backward, as shown in Figure 1, and not strictly in exactly vertical position. The arrow F ₁ indicates the direction of feeding of the crackers.

On the conveyor (2), the crackers are guided laterally to stay in a row. This fixed lateral guide is extended by adjustable guides (4) making it possible to adjust the length (L + e) over which the crackers can be released laterally at the end of the supply row (1).

There is a fixed stop (5) of small thickness arranged horizontally at the height of the axis of the row (1). In Figure 2, the rusks fed by the belt (2) are stopped by this stop. A lateral plunger (6) of small thickness and length (L - e) is arranged on the side of the row, at the same level as the stop (5). It is integral with a transverse heel (7) extending the front edge of the pusher (6). The pusher (6) and the heel (7) thus form an L-shaped part, as shown in FIG. 2 or 3, capable of moving transversely to the axis of the row (1) along the path defined by F ₂ with an amplitude at least equal to the width of the row of rusks. This displacement makes it possible to push the rusks laterally on the reception area (8) over a length between (Le) and (L + e) from the fixed stop (5), thus selecting at the end of the row the number of rusks wanted to constitute a horizontal pile of length appreciably (L ^± e). 2

Note that the fixed stop (5), the pusher (6), the heel (7), as well as the edge of the movable guides (4) on the bank opposite the pusher (6) have rounded edges. This rounded shape in vertical section reduces the useful height where these pieces come into contact with the rusks. It makes it possible to consider their respective positions at the diametral plane of the crackers, thus eliminating as much as possible the variations in size of the crackers due to their possible inclination relative to the vertical.

In continuation of the row (1) of rusks is a movable stop (9) in U whose two horizontal branches are oriented in the opposite direction from that of the rusks supply. These two branches tightly frame the fixed stop (5) and the heel (7) in FIGS. 1, 3 and 4. This movable stop is capable of advancing against the crackers not yet selected, this up to the level of the heel ( 7), as shown in figure 4. The displacement possible is shown by arrow F ₃ in Figure 2.

Finally, it can be noted that the reception area (8) is bordered, upstream and downstream sides by vertical guide walls (10) against which the rusks placed at the ends of the stack are supported. These walls keep the rusks selected in vertical position to form each stack.

This is particularly essential if the area (8) is in the form of an elevator platform.

The use of an elevator tray as a reception area (8) allows the use of two parallel and symmetrical devices for grouping rusks in stacks. The two devices symmetrical with respect to the plate feed a single plate (8) of sufficient size which, during the period when the movable stop (9) moves back, transfers the rusks to a higher or lower level, where packaging can take place. two batteries simultaneously.

With crackers of common dimensions, the device described makes it possible to produce stacks of 15 to 30 crackers according to the length L chosen.

The device described can obviously be used for other objects with mechanical characteristics close to those of rusks.

Claims (9)

1. Method for grouping into stacks of determined length (L - e) flat, fragile and rough objects, such as rusks, the dimensions of which are defined with poor tolerances, this grouping being effected from said objects, supplied with contiguous rows in which they are arranged in planes substantially perpendicular to the axis of the rows, this process consisting, in each row, of immobilizing the objects against a stop, then pushing transversely on a lateral reception area, using a side pusher, a series of objects directly upstream of the stop over a determined length (L ^± e) while retaining the objects upstream and keeping them in their orientation, then return the side pusher to its position initial, finally, to allow the objects remaining in the row to advance again by length (L), these objects being held contiguous and substantially perpendicular to the row by a movable stop which moves the ntement to allow a new operation, characterized in that the initial immobilization of the objects is done by a median zone parallel to the base plane of the row, this by means of a fixed stop 5, of small thickness and arranged substantially in the row axis, in that the lateral thrust of the objects to be grouped also exerts in the same axial plane relative to the row, this by a lateral pusher 6 of the same thickness and moving in the axial plane defined by the stop 5, finally, in that before returning the pusher 6 to its initial position, its heel 7 is released from the thrust of the objects by pushing them back slightly by means of the movable stop 9 whose ends advance against the current , slightly beyond the heel 7 of the pusher. 2. Method according to claim 1, characterized in that the movable stop 9, when it moves back at the end of the cycle, moves at a speed at most equal to the speed of the conveyor, feeding the objects in contiguous rows. 3. Method according to any one of claims 1 or 2, characterized in that the objects are in contact either with the fixed stop or with the heel of the lateral pusher, only over a height less than the respective thickness of these parts, this thanks to the rounded edges in vertical section of said parts. 4. Device for grouping into stacks of determined length (L ±

) of flat, fragile and rough objects, according to the method defined by any one of claims 1, 2 or 3, comprising in the first place a conveyor feeding the objects in contiguous rows in which they are arranged in planes substantially perpendicular to the transporter's axis, secondly, a movable stop moving along the axis of the row of objects and, thirdly, a lateral pusher making it possible to push and group together on a lateral reception area the objects located at the head row lengthwise (L ±

) characterized in that the device further comprises a fixed stop 5 substantially in the axis of row 1, this stop having a small thickness measured parallel to the base plane of the conveyor 2, in that the lateral pusher 6-7 has same thickness as the stop 5 and moves in the axial plane defined by the stop 5, finally, in that the movable stop 9 has a U-shape whose horizontal branches oriented upstream tightly frame the stop 5 and the heel 7 of the pusher, this in an axial plane perpendicular to the base plane of the conveyor 2. 5. Device according to claim 4, characterized in that the thickness of the fixed stop 5 and of the lateral pusher 6-7 is of the order of 1 / 10th of the height of the row of objects on the transporter. 6. Device according to claim 5, characterized in that the front faces of the fixed stop 5 and of the heel 7, as well as the rear face of the adjustable guides 4 are rounded in a vertical cutting plane, this reducing the contact surface with objects, while allowing objects to appear slightly inclined to the vertical, while only taking into account the effective length of 1 ₃ stack of objects along its axis. 7. Device according to any one of claims 4, 5 or 6, characterized in that the ends of the branches of the movable stop 9 can move against the flow of objects slightly beyond the heel 7 of the lateral pusher and can, conversely, move back below the fixed stop 5. 8. Device according to any one of claims 4, 5, 6 or 7, characterized in that the length of the pusher is L - e. 2 9. Device according to any one of claims 4, 5, 6, 7 or 8, characterized in that the reception area 8 is an elevator tray.

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