WO1992005097A1 - Method and machine for transferring objects on a network of rails - Google Patents

Abstract

The machine for transferring finished or semi-finished objects arranged on or hanging from pallets circulating translationally and according to a cycle of at least two phases, following a predetermined closed circuit, on rails, according to the method of the invention, is comprised of a network of rails having at least four sections (I, II, III, IV) at right angles to each other, means (V1 to V13) for pushing the adjacent pallets (10) and advancing them on the rail sections, and storage areas (E, F, G, H) located in the angles defined by the rail sections. During a first phase, at least two pallets (16', 17') advance by two places simultaneously on a first rail section and at least one pallet (15') is pushed from the storage area (E) to the second rail section. During a second phase, at least two pallets (15', 16') advance simultaneously two places on said second rail section while the pallet (17') is pushed into the storage area (E).

Description

 METHOD AND MACHINE FOR TRANSFERRING OBJECTS ON A RAIL NETWORK

The present invention relates to a process for transferring finished or semi-finished objects or assembly parts, placed on or suspended under pallets arranged to travel in translation one behind the other, between several loading stations respectively, working and unloading, according to a predetermined closed circuit, on a network of rails comprising at least four perpendicular sections two by two, in which one pushes cyclically step by step, in block, sets of pallets juxtaposed on each of said sections of rails according to said circuit.

It also relates to a machine for transferring finished or semi-finished objects or assembly parts, placed on or suspended under pallets arranged to travel in translation one after the other, between several stations respectively for loading, working and unloading, - according to a predetermined closed circuit, on a network of rails comprising at least four sections two by two perpendicular, this machine also comprising means for pushing cyclically step by step, in block, sets of pallets juxtaposed on each said sections of rails according to said circuit.

Transfer machines of this type are known in particular in the industry of the manufacture of plastic containers, produced by blowing from preforms. These machines usually comprise a unit for loading preforms onto pallets, an oven for preheating these preforms which the pallets pass through for a period of time necessary for the softening of the material, a blow molding press and an unloading station. finished products.

Other applications can of course be envisaged, in particular the assembly or mounting of sub-assemblies of mechanical parts. nics, heat or mechanical treatment of finished or semi-finished products, etc.

In the case where a work station requires a longer time than the others, it is advantageous to be able to process several objects simultaneously, that is to say to be able to bring several pallets carrying these objects into this station simultaneously. This is for example the case of a blowing press which generally consists of two half-molds which must be discarded to allow the introduction of the pallets, then close before they can actually start the actual molding phase. The opening time and the closing time of the mold are dead times which can considerably lengthen the machine cycle if it is added to the actual processing time of each product. On the other hand, if several products can be treated simultaneously, these idle times, reported for each product, are divided by the number of products treated simultaneously. In other words, the machine will be more efficient if the dead time corresponding to the opening and closing of the mold is used to introduce four pallets into this mold, than if it only corresponds to the introduction of one pallet.

One of the problems which arises in this case is that of the temporary storage of the pallets which are waiting to be introduced into the mold while the other pallets continue to advance in jerks. Indeed, if we want to introduce into one of the machine's workstations a number of products greater than the number of objects that are moved at each step, these objects should be stored until this number is reached, then to store them move en bloc as soon as they are complete.

The device described by international publication WO 85/01718 comprises at least one closed circuit comprising sections arranged at right angles and providing a storage area formed in the corner of two adjacent sections. However, this storage area is only a buffer from which the products, temporarily stored, are taken one by one to be reintegrated into the circuit. Such device does not allow the intermittent advance of products where each step corresponds to a displacement of a whole number of products greater than one.

This problem is solved by the method according to the invention which makes it possible to increase the production capacity of the machine thanks to a reduction in the downtime imposed by certain work stations.

In a machine according to the invention, when it is desired for example to introduce four pallets simultaneously into a work station, it is possible to put three pallets in a waiting position before being able to simultaneously move the four pallets to introduce them into desktop.

For this purpose, the method according to the invention is characterized in that each cycle comprises at least four phases, in that at each cycle one moves in block, during at least one of said phases, on at least one of said rail sections, the set of pallets which are juxtaposed therein, of an integer number of rows n greater than or equal to two, in that one stores at each cycle, during at least one of said phases , at least one pallet in a storage area arranged in the angle defined by said rail section and another rail section adjacent and perpendicular to this section, and in that at each cycle it is moved as a block, during at least one of said phases, on said other section, all of the pallets which are juxtaposed therein, with an integer number of rows m at least equal to two.

In a preferred form of the method, at each cycle, during at least one of said phases, a pallet of said one section of rail is moved in the storage area, and during at least one of the other phases, this storage area on said other section of rail.

Advantageously, at each cycle, all of said pallets juxtaposed on said one section of rail with a number of rows n equal to two are moved in block, during at least two of said phases, and the we move in a block, during at least one of said phases, said pallets juxtaposed on said other section with a number of rows m equal to a multiple of two.

Preferably, the number of rows m of which all of the pallets juxtaposed on said other section of rail are moved in block, during at least one of said phases, is equal to four, two of these pallets having been previously successively stored in said storage area during two of said phases.

In an advantageous form of the method, at each cycle, during a first phase, two rows of blocks are pushed simultaneously, in block, all of the pallets juxtaposed on said one section of rail thus bringing two pallets onto the last two spaces. of this section, and of a row, parallel to this section, a pallet previously brought into the storage area during a previous cycle, from this storage area to the second space of said other section of adjacent and perpendicular rail to said one section of rail, thus bringing said pallet and the first of said pallets to the first two spaces of said other section of rail; during a second phase, said two pallets of said two first spaces of said other section of rail are pushed simultaneously from two rows, as a block, onto the third and fourth spaces of this section, and one row, parallel to said another section of rail the second of said two pallets of the penultimate space of said one section of rail in the storage area; during a third phase, all of the pallets juxtaposed on said one section of rail are pushed simultaneously from two rows, as a block, thus bringing two new pallets to the last two spaces of this section released during the second phase, and in a row, parallel to said section, said pallet brought into the storage area during said second phase, from this storage area to the second space of said other section of rail; and during a fourth phase, all of the pallets juxtaposed on said other section of rail are pushed simultaneously from four rows, in a block, thus bringing the two pallets brought to this section suddenly during said first phase and the two pallets brought to it section during said third phase, of the first four spaces of this rail section on the following four spaces, and of a row, parallel to said other section of rail, the second pallet of said pallets of the penultimate space of said one section of rail in the storage area.

The transfer machine for implementing the method according to the invention is characterized in that it comprises means for moving in block, during at least one of said phases, on at least one of said sections of rail, the set of pallets which are juxtaposed therein, with an integer number of rows n greater than or equal to two, a storage area arranged to store at each cycle during at least one of said phases, at least one pallet, this storage area being located in the angle defined by said section of rail and another section of rail adjacent and perpendicular to this section of rail, and means for moving at each cycle, as a unit, during at least one of said phases, on said other section of rail, all of the pallets which are juxtaposed with an integer number of rows m at least equal to two.

According to a preferred embodiment, the machine comprises means for moving at each cycle, during at least one of said phases, a pallet of said one section of rail in the storage area, and from this storage area onto said other section rail ^ during at least one of the other phases.

According to an advantageous embodiment, the machine comprises means for moving at each cycle, in a block, during at least two of said phases, all of said pallets juxtaposed on said one section of rail with an equal number of rows n in pairs, and to move as a block, said pallets juxtaposed on said other section of rail with a number of rows m equal to a multiple of two, during at least one of said phases. Preferably, said means for advancing the pallets comprise hydraulic or pneumatic cylinders and members for controlling these cylinders.

According to a particularly advantageous embodiment, the machine can comprise at least a first cylinder arranged to move the set of pallets in a block of two rows on said one section of rail, at least a second cylinder arranged to push at least one pallet of the storage area on said other section of rail, at least a third cylinder for moving all of the pallets simultaneously, either by two rows or by four rows, on said other section of rail, and at least a fourth cylinder arranged for push at least one pallet of said section on the storage area.

Said storage area may include a support platform provided with stop means arranged to position the pallets in abutment, these pallets comprising a protruding stud arranged to be able to bear against said stop means.

Advantageously, said stop means comprise a central block of substantially rectangular shape, two first adjacent sides of which define a first guide path for said pallets and the other adjacent sides of which define a second guide path for said pallets. Said first guide track corresponds to the passage of the pallets through the storage area.

The present invention will be better understood with reference to the description of an embodiment and the accompanying drawing in which: FIGS. 1, 2, 3 and A illustrate the four phases of a cycle of a machine according to the invention,

FIG. 5 partially illustrates a construction of a machine according to the invention, and Figure 6 shows a top view of the realization of the storage area of the machine of the invention.

With reference to FIG. 1, the circuit of the pallets which for example have a rectangular shape, but which could also be square, comprises four sections 1, II, III and IV arranged along the sides of a large rectangle, parallel to the sides of the pallets. A loading zone A is defined by the angle of the two sections I and IV, a preheating zone B is arranged on the section 1, a blowing press C, or any other work station in which the products must remain for one predeter¬ mined time interval, is arranged on section II and a recovery zone for these products, designated by the letter D, is also arranged on section II downstream from work station C.

In order for the machine to operate as intended, a storage area E is provided in the corner of sections I and II. In practice, similar storage areas F, G and H respectively are provided in each of the other three angles of the circuit. The operation of the machine, that is to say the routing of rectangular pallets 10 which circulate on the different sections, will only be described at the level of their passage from section 1 to section 11, the passages from section II to the section III, of the section 111 on the section IV and the return of these pallets on the section I being in fact less critical and which can ultimately be carried out in any way. However, in the machine described, these various steps are carried out in the same manner as that which will be described below.

We start from the assumption that the places 11, 12, 13 and 14- of section II are free, given that during a previous stage the four pallets 11 ', 12', 13 'and 1W which occupied them were pushed back simultaneously to be introduced into the press C by a thrust member such as for example a pneumatic or hydraulic cylinder V2 illustrated by an arrow. During this previous step, the pallet 15 'which previously occupied it now vacuum 15 has been pushed from one row to storage area E by a hydraulic or pneumatic cylinder VI, also shown diagrammatically by an arrow. At the start of the cycle which will be described below, the pallet 15 ′ is in the storage area E and the spaces 11 to 15 are empty. This state can be considered as the initial state.

During a first phase of this cycle, the entire line of pallets arranged on section I will move two rows from top to bottom (in FIG. 1) under the effect of a corresponding thrust exerted by a jack. V13. This has the effect of bringing the two end pallets 16 ′ and 17 ′ of this line of pallets to the empty locations respectively 11 and 15, as also shown in FIG. 2. Simultaneously a hydraulic or pneumatic cylinder V3, pushes the pallet 15 ′ of the storage area E onto the empty location 12, so that the storage area becomes empty again and can again receive a pallet.

The second phase is illustrated in FIG. 3. During this phase, the two pallets 15 'and 16' are pushed in two rows along the section II in the direction of the press C, by means of the jack V2 to occupy the locations empty 13 and 14. As a result, the locations 11 and 12 become free again. Simultaneously the jack VI pushes the pallet 17 'into the storage area, again freeing the location 15.

During the third phase of this cycle represented by FIG. 4-, two new end paddles 18 'and 19' are pushed by the jack V13 at the end of the section I to occupy the empty locations 11 and 15. Simultaneously the jack V3 releases the storage area E by pushing the pallet 17 to the previously released location 12.

During the fourth phase, the four pallets 15 ', 16' 17 'and

18 'are pushed simultaneously into the press by the jack V2 and the pallet 19' is pushed into the storage area by means of the jack VI, which makes it possible to find the configuration schematically represented by FIG. 1.

In the other angles of the different sections, the operations are carried out in a similar manner. It will be noted that at the storage area F located in the corner of the sections II and III, cylinders V4, V5 and V6 and V7 are provided. In the corner of sections III and IV, the cylinders V8, V9 and V10 are associated with the storage area G and in the corner of sections IV and I, the cylinders Vil, V12 and V13 are associated with the area storage H.

In the corner of sections II and III, the situation is initially as follows: four empty pallets, since they have just been discharged in recovery area D, are arranged in line at the end of section II. On the adjacent section III, the pallets are placed side by side at the end of the section corresponding to the storage area F. This storage area is empty. Let us designate by the reference 21 'the pallet which occupies the second row on the section III, starting from the angle of the two sections II and 111. The four pallets placed at the end of the section II bear the references 22', 23 ' , 24 'and 25'.

The empty place in the storage area is designated by the reference 26. During the first phase of the cycle, the cylinder V6 pushes the two pallets 21 'and 22' of two rows on the section III and the cylinder V5 pushes simultaneously the pallet 23 'on the storage area where it will occupy the free space 26. The places 21, 22 and 23, previously occupied respectively by the pallets 21', 22 'and 23' become free. During the next phase, the jack V7 pushes the two pallets 24 'and 25' at the end of the section II and simultaneously, the jack V4 pushes the pallet 23 momentarily stored on the storage area F. Therefore, the pallets 24 'and 25' are placed on the free places 22 and 23 and the pallet 23 'is placed on the free place 21. A new push of the jack V6 moves the pallets 21', 22 ', 23' and 24 ′ of two rows along section III and, simultaneously, the jack V5 pushes the pallet 25 ′ into the storage area F, which makes it possible to find the configuration illustrated by FIG. 4. As this figure shows, the four locations 22, 23, 24 and 25 the end of the section II and the location 22 in the second row on the section III are released and ready to receive on the one hand four pallets leaving the mold and on the other hand the pallet 25 ′ previously brought into the storage area F.

In the corner of sections III and IV, the pallet transfer-storage process is similar to that which has been described. Initially, that is to say at the start of a cycle, the locations corresponding to the last two positions 32 and 33 of the section III and to the second position 31 on the section IV are free. The four pallets whose transfer from section III to section IV will be studied will bear the references 30 ', 31', 32 'and 33'. A pallet 30 "occupies the storage area G corresponding to the location 30 of a pallet. During the first phase of the process, the two pallets 31 'and 32' are pushed in two rows by the jack V6 to occupy the free positions 32 and 33. Simultaneously, the pallet 30 'is pushed into the empty space 31. The pallets 33' and 34- 'therefore take the places previously occupied by the pallets 31' and 32 'and the place 30 The cylinder V10 pushes the two pallets 30 'and 31' in two rows on section IV during the second phase of the process.At the same time, the cylinder V9 pushes the pallet 32 'into the storage area G. De this fact, as shown in FIG. 3, the locations 31, 32 and 33 become free again. During the next phase illustrated in FIG. 4, the jack V6 pushes the two pallets 33 ′ and 34 ′ on the free locations 32 and 33 and the palette

32 'on the free space 31. After a push of the jack V10 moving the row of pallets of section IV by two rows and a push of the jack V9 to transfer the pallet 34' to the storage area G, the configuration is at again identical to that of figure 1.

In the angle of sections IV and I, the cylinders V12 and Vil have the function of alternately transferring a pallet of section IV into the storage air H and then this pallet of this storage area onto section I. FIG. 5 represents a real construction of the machine of the invention, seen from above. In addition to the rail sections, the blow molding press C and the various jacks, this figure also shows shock absorbers 50, which are for example pneumatic shock absorbers and which are arranged at different angles in the extension of the different sections. It will also be noted that the cylinders V2 and VIO are traction cylinders and not thrust cylinders. To this end, they are equipped with a movable rod 51, respectively 52, carrying at its end hooking elements 53, respectively 54 which cooperate with a protuberance disposed either above or below each pallet.

The construction of the storage area will be described in more detail with reference to Figure 6.

As this figure shows, the storage area is defined by a platform 60 which is mounted in the angle of two adjacent sections, for example sections 1 and II. In its central zone, the platform 60 has a protuberance 61 which makes it possible to guide the pallets in their movement. Indeed, the pallets preferably have at their lower surface a guide stud 63 which is engaged in an axial groove of the rails. When the pallets arrive at the end of a section, the guide stud leaves the groove and bears on the platform 60. The guidance is then supported on the one hand by the edges of the protuberance 61 and on the other hand, by bearing edges surrounding the storage area. In this way the pallets can follow either the direct path, illustrated by the arrow 62, which in fact represents the path followed by the pallet which is pushed to the end of the section I, then directly onto the section II, or the route represented by arrows 64 and 65 which corresponds to the route followed by the second pallet pushed towards the end of section I and which transits through the storage area before being transferred to section II.

The present invention is not limited to the embodiments described, but can undergo various modifications and appear in various variations obvious to those skilled in the art. In particular, it is conceivable to change only one pallet on n pallets, in particular for the purpose of molding objects of large dimensions.

Claims

claims 1. Method for transferring finished or semi-finished objects or assembly parts, placed on or suspended under pallets arranged to travel in translation, one behind the other, between several loading, working and unloading, according to a predetermined closed circuit, on a rail network comprising at least four perpendicular sections two by two, in which is pushed cyclically step by step, in blocks, sets of pallets juxtaposed on each of said sections of rails according to said circuit, characterized in that at each cycle comprises at least four phases, in that at each cycle one moves in a block, during at least one of said phases, on at least one of said sections of rail (I) , the set of pallets which are juxtaposed therein, of an integer number of rows n greater than or equal to two, in that one stores at each cycle, during at least one of said phases, at least one palette in a storage area (E) formed in the angle defined by said rail section (I) and another rail section (II) adjacent and perpendicular to this section, and in that at each cycle it is moved in a block , during at least one of the said phases, on the said other section, the set of pallets which are juxtaposed therein, with an integer number of rows m at least equal to two. 2. Method according to claim 1, characterized in that at each cycle, during at least one of said phases, a pallet is moved (15 ', 17') of said one section of rail (I) in the storage area (E), and during at least one of the other phases of this storage area (E) on said other section of rail ( II). 3. Method according to claim 1, characterized in that at each cycle is moved in a block, during at least two of said phases all of said pallets juxtaposed on said one section of rail (I) of a number of rows n equal to two, and one moves in a block, during at least one of said phases, said pallets juxtaposed on said other section of rail (II) with a number of rows m equal to a multiple of two. 4. Method according to claim 3, characterized in that the number of rows m of which all of the pallets juxtaposed on said other section of rail (II) are moved in block, during at least one of said phases is equal to four , two of these pallets (15 ', 17') having previously been successively stored in said storage area (E) during two of said phases. 5. Method according to claim, characterized in that at each cycle, during a first phase, simultaneously pushes two rows, in block, all of the pallets juxtaposed on said one section of rail (I) bringing thus two pallets on the last two spaces of this section (I), and of a row, parallel to this section (1), a pallet (15 ') previously brought into the storage area (E) during a previous cycle, of this storage area (E) on the second space (12) of said other rail section (II) adjacent and perpendicular to said rail section (I), thus bringing said pallet (15 ') and the first ( 16 ') of said pallets (16', 17 ') on the first two spaces (11, 12) of said other section of rail (II); in that during a second phase, said two pallets (16 ', 15') of said two first spaces (11, 12) of said other section of rail are pushed simultaneously in two rows, in a block ) on the third (13) and fourth (14) spaces of this section (II), and of a row, parallel to the rail section (II), the second (17 ') of said two pallets (16 ", 17' ) from the penultimate space (15) of said section of rail (I) in the storage area (E); in that during a third phase, two rows are pushed simultaneously, block, the set of pallets juxtaposed on said one section of rail (1), thus bringing two new pallets (18 ', 19') to the last two spaces of this section of rail (I) released during the second phase , and in a row, parallel to said section (1), said pallet (17 ') brought into the storage area (E) during said second phase, from this storage area (E) to the second space (( 12) of said other section of rail (II); and in that during a fourth phase, all of the pallets juxtaposed on said other section are pushed simultaneously by four rows, in a block rail (II), thus bringing suddenly the two pallets (15 ', 16') brought on this section (II) during said first phase and the two pallets (17 ', 18') brought on this section (II) during said third phase, of the first four spaces of this rail section (II) over the following four spaces, and of a row, parallel to said other rail section (II), the second pallet (19 ' ) of said pallets (18 ′, 19 ′) of the penultimate space (15) of said section of rail (I) in the storage area (E). 6. Machine for transferring finished to semi-finished objects or assembly parts, arranged on or suspended under pallets arranged to travel in translation one last the other, between several stations of loading, working and unloading, according to a predetermined closed circuit, on a rail network comprising at least four sections two by two perpendicular, this machine also comprising means for pushing cyclically step by step, in a block, sets of pallets juxtaposed on each of said sections of rails according to said circuit, characterized in that it comprises means for moving as a unit, during at least one of said phases, on at least one of said rail sections (I), all of the pallets which are there juxtaposed, with an integer number of rows n greater than or equal to two, a storage area (E) arranged to store at each cycle, during at least one of said phases _; at least one pallet, this storage area being located in the angle defined by said rail section (I) and another rail section (11) adjacent and perpendicular to this rail section, and means for moving at each cycle , en bloc, during at least one of said phases, on said other rail section (II), the set of pallets which are juxtaposed therein with an integer number of rows m at least equal to two. 7. Machine according to claim 6, characterized in that it comprises means for moving at each cycle, during at least one of said phases, a pallet (15 ', 17') of said one section of rail (I ) in storage area (E), and from this storage area (E) on said other section of rail (II) _, during at least one of the other phases. 8. Machine according to claim 7, characterized in that it comprises means for moving at each cycle, in a block, during at least two of said phases, all of said pallets juxtaposed on said one section of rail ( I) of a number of rows n equal to two, and in that one moves in a block, during at least one of the said phases, the said pallets juxtaposed on the said other section of rail (II) by a number of rows m equal to a multiple of two. 9. Machine according to claim 6, characterized in that said means for advancing the pallets comprise hydraulic or pneumatic cylinders and control members of these cylinders. 10. Machine according to claim 6, characterized in that it com¬ carries at least a first cylinder (V13) arranged to move the set of pallets in blocks of two rows on said one section of rail (I), at least a second cylinder (V3) arranged to push at least one pallet from the storage area onto said other section of rail (II), at least one third cylinder (V2) for moving all of the pallets simultaneously, that is to say two rows either four rows, on said other section of rail (II), and at least a fourth jack (VI) arranged to push at least one pallet of said one section of rail (I) on the storage area (E). 11. Machine according to claim 6, characterized in that the storage area comprises a support platform (60) provided with abutment means (61) arranged to position the pallets (10) in abutment, these pallets comprising a stud protruding (63) arranged to be able to bear against said abutment means (61). 12. Machine according to claim 11, characterized in that said abutment means (61) comprise a central block of substantially rectangular shape, two first adjacent sides of which define a first guide path for said pallets and the other adjacent sides of which define a second guide path for said pallets. 13. Machine according to claim 12, characterized in that said first guide track corresponds to the passage of the pallets through the storage area (E).