WO2017195227A1

WO2017195227A1 - Package chain conveyor in which the positioning of the package int he sliding seat thereof is automatically adjustable

Info

Publication number: WO2017195227A1
Application number: PCT/IT2016/000147
Authority: WO
Inventors: Gianpietro MIGLIORINI
Original assignee: MIGLIORINI S.r.l
Priority date: 2016-05-12
Filing date: 2016-06-03
Publication date: 2017-11-16
Also published as: ITUA20163398A1

Abstract

The invention relates to a package conveyor (1) of the "chain" type comprising a longitudinal seat (3) for housing and sliding the packages(4) to be handled, a pair of chains (6) extending parallel to the aforesaid seat over the whole length thereof, a plurality of toothed wheels (7) meshing with the aforesaid chains for supporting and actuating them, a first motor (9) having a shaft (8) rotationally coupled to at least two of the aforesaid toothed wheels in order to slide the chains synchronously, and a plurality of pushers (10) connected to the chains by means of a respective pin (11) about which the pushers can rotate between an engaging position (10b), in which they at least partially penetrate the aforesaid seat (so as to intercept the packages possibly housed therein), and a disengaging position (10a), in which they do not penetrate the aforesaid seat. The conveyor which is the object of the invention further comprises a rectilinear bar (15) sliding between the two chains by means of a rack (16) meshing with a toothed wheel (17) rotationally coupled to a second motor. The bar can be translated so as to intercept the pushers when they are at the upper stretch of the chains, rotating them from the disengaging position to the engaging position and supporting them in this position. By means of the aforesaid bar it is thus possible to adjust both the point of the sliding seat in which the pushers rotate from the disengaging position to the engaging position (thus intercepting the packages possibly housed therein), and the point of the sliding seat in which the pushers rotate from the engaging position to the disengaging position (stopping the sliding of the packages). In an alternative embodiment of the conveyor which is the object of the invention, the latter further comprises a rail placed at the upper stretch of the chains and on which the pushers translate to the engaging position. The extension of the rail is smaller than that of the package sliding seat so that only the point of the seat in which the pushers rotate from the engaging position to the disengaging position can be adjusted by means of the aforesaid translatable bar.

Description

Package chain conveyor in which the positioning of the packages in the sliding seat thereof is automatically adjustable

Field of application of the invention

The present invention relates to the field of devices for handling packages. More specifically, the present invention relates to a package conveyor of the "chain" type in which the position occupied by the packages in the sliding seat thereof is automatically adjustable by a user of the conveyor belt.

Overview of the prior art

Chain conveyors generally comprise:

· a longitudinal seat for housing and sliding the packages to be handled;

• at least one chain (i.e. a closed-ioop metal chain) preferably extending parallel to the aforesaid seat over the whole length thereof;

• a plurality of toothed wheels meshing with the chain for supporting and actuating it;

· a motor having a shaft rotationally coupled to at least one of the aforesaid toothed wheels to impart a rotary motion thereto so as to slide the chain;

• a plurality of pushers integrally connected to the chain so as to penetrate at least partially the aforesaid seat when the chain is sliding.

The package sliding seat usually consists of a base and two side walls which confer a substantially C-shaped cross section to the seat, with the C concavity facing upwards. The base of the aforesaid seat is crossed by an opening which extends over the whole length of the seat and in which the pushers actuated by the chain translate. The chain is preferably placed under the base of the seat so as not to hinder the operations of loading and picking the packages on the conveyor.

To be conveyed, a package is placed in the sliding seat, usually close to a conveyor end. The package is struck by one of the pushers which, drawn by the chain, pushes it along the aforesaid seat to reach the other end of the conveyor where the package can be picked.

Since the pushers are integrally connected to the chain, the distance between the packages in the sliding seat when they are fed cannot be modified. Additionally, the packages are always moving until they are picked from the aforesaid seat. This may be a disadvantage if the packages are picked from the sliding seat by means of automated systems. Indeed, many of these systems can pick packages from a given place providing that the packages are stopped and at a predetermined mutual distance. The latter distance may not correspond to the distance at which the packages slide on the conveyor.

Objects of the invention

It is the object of the present invention to overcome the aforesaid drawbacks and to indicate a chain conveyor in which the position occupied by the packag- es in the sliding seat is automatically adjustable by a user of the conveyor.

Incidentally, the conveyors to which the present invention relate may comprise one or more closed-loop toothed belts or similar motion transmission means instead of the chain. Therefore, in the present description, the term "chain" does not only mean a closed-loop chain but also any element equivalent thereto, i.e. an element extending in length, which can be closed in a loop and used as motion transmission means in a conveyor of the type to which the present invention refers.

Summary of the invention

The present invention relates to a conveyor for at least one package, compris- ing:

• a seat for at least partially housing and sliding said package, said seat extending in a direction; • at least one pusher, which can be at least partially housed in said seat;

• first means suited to actuate the pusher so that it is at least partially housed in said seat and travels along at least one stretch thereof so as to come into contact with said package when it is at least partially housed in said seat and to slide said package in said seat at least over said stretch,

the first actuating means comprising:

- at least a first chain extending in the same extension direction as said seat;

- first sliding means for sliding the first chain;

- connecting means for connecting the pusher to the first chain,

wherein, according to the invention, the first connecting means are suited to allow a displacement of the pusher between at least one engaging position, at which the pusher is at least partially housed in said seat, and a disengaging position, at which said pusher is not housed in said seat,

the conveyor further comprising:

• second means suited to move the pusher between the aforesaid engaging and disengaging positions.

In the conveyor which is the object of the present invention, in order to slide a package, it must be placed in the aforesaid seat and the first and second actu- ating means must be actuated so as to translate the pusher to the engaging position along the aforesaid seat. By moving forward along the sliding seat, the pusher intercepts the package and pushes it along the seat. Advantageously, the sliding of said package can be stopped when a given position is reached by actuating the second actuating means again so as to move the pusher to the disengaging position.

Further innovative features of the present invention are described in the dependent claims.

Brief description of the drawings

Further objects and advantages of the present invention will become apparent from the following detailed description of an embodiment thereof and from the accompanying drawings, merely provided by way of non-limitative example, in which: - figure 1 shows a partial perspective view of an end portion of a chain conveyor according to the present invention;

- figure 2 shows a diagrammatic straight section of the end portion in figure 1 ;

- figure 3 shows a diagrammatic straight section of a second end portion of a conveyor according to the present invention, opposite to the end portion in figure 1.

Detailed description of preferred embodiments of the invention

In the rest of the present description, a figure may also be shown with reference to elements indicated in other figures and not expressly indicated in that figure. The scale and proportions of the various depicted elements do not necessarily correspond to real values.

Figure 1 shows an end portion of a conveyor 1 of the "chain" type. More specifically, figure 1 shows the portion of conveyor 1 at which one or more packages 4 can be loaded on conveyor 1 for feeding them to the opposite end of conveyor 1 (seen in figure 3).

Conveyor 1 comprises a rail 2 which delimits a seat 3 at which the packages 4 are at least partially housed. Each of the two reciprocally parallel guides which form rail 2 preferably comprises a metal sheet extending in length and having an L-shaped cross section. Rail 2 and seat 3 therewith preferably extend over the whole length of conveyor 1 . Assuming for simplicity that rail 2 is rectilinear, it is preferably arranged so that the two sheet strips corresponding to the two L- shaped arms of a guide 2 are symmetric with respect to the two sheet strips corresponding to the two L-shaped arms of the other guide 2, i.e. with the L concavities reciprocally facing each other. More preferably, the guides 2 are al- so symmetric with respect to a vertical plane interposed therebetween, so that the two sheet strips of the two guides 2 are arranged vertically and the other two sheet strips are coplanar and arranged horizontally. Therefore, as a whole, the seat has a base and two side walls which confer an almost C-shaped cross section thereto, with the C concavity facing upwards. The guides 2 are spaced apart from each other. As a consequence, seat 3 comprises a longitudinal opening 5 at the base interposed between the guides 2 and extending over the whole length of the latter. As shown in figure 1 , the packages 4 may rest on rail 2 at the horizontally arranged sheet strips. More precisely, the width of each package 4 is preferably smaller than the distance between the aforesaid sheet strips arranged vertically but greater than the width of opening 5 (i.e. the distance between the aforesaid horizontally arranged sheet strips).

Conveyor 1 preferably comprises two chains 6 (only one of which is shown in the figures) each of which almost describes a rectangle having two arcs of circumference instead of the short sides. The chains 6 preferably lie on a respective vertical chain and face each other. The chains 6 are preferably placed un- der rail 2, at opening 5 and extend over the whole length of conveyor 1 parallel to rail 2. Conveyor 1 also comprises a plurality of toothed wheels 7 (only two of which are seen in figure 1) meshing with the chains 6 to support and actuate them. The chains 6 and the toothed wheels 7 are, as a whole, preferably symmetric with respect to the mentioned vertical symmetry plane of rail 2. Two of the aforesaid toothed wheels 7 are fitted on the same shaft 8 of a motor 9 suited to rotate the wheels 7 and therefore to slide the chains 6. The drive wheels 7 thus work as sliding means for the chains 6 while the remaining idle wheels 7 perform a supporting and tensioning function on the chains 6. By virtue of the aforesaid flat symmetry and fitting to the same shaft 8 of the drive wheels 7, the two chains 6 synchronously slide in the same direction when motor 9 is actuated.

Conveyor 1 further comprises a plurality of pushers 10 for displacing the packages 4 along seat 3. Each pusher 10 is preferably connected to both chains 6 so as to be fed by the latter when they slide on the toothed wheels 7. For sim- plicity of illustration, figure 1 shows pusher 10 coupled to a single chain 6. As shown in greater detail with reference to the following figures 2 and 3, when the pushers 10 lie at the upper stretch of the chains 6, they may be actuated so as to penetrate partially seat 3 through the longitudinal opening 5. Thereby, the pushers 10, fed by the chains 6, can intercept a package 4 possibly present there, so as to push it along seat 3 for a given stretch thereof. By means of the pushers 10, the packages 4 can thus be fed by the chains 6 over rail 2, sliding along seat 3. Alternatively, the guides of rail 2 may comprise rolls having a co- planar and orthogonal axis with respect to the chains 6, or may be replaced by said rollers, so as to convert the sliding motion of the packages 4 into a rolling motion over said rollers. In figure 1 , for the purposes of transporting the packages 4, the chains 6 slide clockwise, so as to determine a feeding of the pack- ages 4 from the left rightwards.

With reference to figures 2 and 3, it can be noted that each of the pushers 10 is connected to the chains 6 by means of a pin 1 1 preferably arranged orthogonally to the chains 6 in an intermediate position therebetween. Pin 1 1 is preferably positioned, outside the plane tangent to the upper stretch of the chains 6, at a higher height than said plane. Each pusher 10 preferably reproduces a substantially set square-shaped structure, i.e. comprising a first arm 12 and a second arm 13 which are not aligned and even more preferably are arranged so as to be mutually orthogonal in order to allow pusher 10 to take an almost L-shaped cross section. In an intermediate position between the arms 12 and 13, and preferably at the joint between them, pusher 10 comprises a housing hole for pin 1 1 so that pusher 10 can rotate about said pin 1 1 . The weight of arm 12 is greater than that of arm 13. For this reason, when free from any support (as, for example, in the lower stretch of the chains 6), the pushers 10 (in figure 2) lie so that arm 12 is arranged almost vertically and arm 13 is arranged almost hori- zontaily, with reference to seat 3. The pushers 10 lie under seat 3 when they are in this position (previously indicated as "disengaging position" and indicated in the figures with reference numeral 10a). In other words, they do not penetrate the latter when they lie at the upper stretch of the chains 6. As a result, when the pushers 10 are in the disengaging position 10a, the packages 4 cannot be intercepted by the pushers 10. More specifically, as shown in figure 3, when the pushers 10 are in the disengaging position 10a and motor 9 is actuated, the pushers 10 slide under the packages 4, without pushing them. In this condition, the packages 4 are thus stopped in seat 3 despite the sliding of the chains 6. As shown in figures 2 and 3, each pusher 10 comprises a wheel 14 freely pivot- ed to arm 12 preferably close to an end of the latter opposite to the housing hole of pin 1 1 . Wheel 14 contributes to arm 12 being heavier than arm 13.

Conveyor 1 also has a preferably rectilinear bar 15 sliding under seat 3 by means of a rack 16 (diagrammatically shown in figures 2 and 3 as a chain) meshing with at least one toothed wheel 17 rotationally coupled to a second electric motor (not shown in the figures). Bar 15 is preferably arranged parallel to the guides of rail 2 and can translate in longitudinal direction (i.e. remaining aligned thereto) by means of the aforesaid second motor. Bar 15 thus extends in the same extension direction as seat 3. Bar 15 is in an intermediate position between the guides of rail 2 and lies under them, at the arm 12 of the pushers, at a height such as to intercept said pushers 10 when they are in relative motion with respect to bar 15 along the upper stretch of the chains 6. More in detail, bar 15 lies under the upper stretch of the chains 6 at the lower end of the pushers 10.

When the pushers 10 are in the disengaging position 10a at the aforesaid upper stretch of the chains 6, they protrude under the chains so as to be in contact with bar 15 at arm 12, and preferably at wheel 14. Considering, by way of ex- ample, a pusher 10 which, in the disengaging position 10a, gradually approaches bar 15 until it strikes it, it can be noted that upon the striking and movement, pusher 10 rotates about pin 11 (clockwise in figures 2 and 3) until it is positioned with arm 12 arranged almost horizontally over bar 15 and arm 13 arranged almost vertically. In this position (previously indicated as "engaging posi- tion" and indicated in the figures with reference numeral 10b), the pushers 10 rest on bar 15 and are partially housed in seat 3, penetrating it with arm 13 through opening 5. More specifically, when the pushers 10 are in the engaging position 10b, arm 13 protrudes from the top of seat 3 to intercept a package 4 possibly present there. As shown in figure 2, when the pushers 10 are in the engaging position 10b and motor 9 is actuated, the pushers 10 are in contact with the packages 4 at arm 13 pushing them along seat 3. In this condition, the packages 4 move integrally with the chains 6.

When a pusher 10 is in the engaging position 10b, pusher 10 rests on bar 15 preferably at wheel 14. Wheel 14 preferably rolls on bar 15 when pusher 10 and bar 15 are in a mutual relative motion in addition to being in contact (e.g. when the chains 6 slide and bar 15 is stopped with respect to the latter).

In light of the above, bar 15, when it is in contact with the pushers 10, performs a supporting function for the latter keeping them in the engaging position 10b. More specifically, with reference to a pusher 10 which is at the upper stretch of the chains 6, when bar 15 and pusher 10 are in contact, bar 15 lies in a supporting position with respect to pusher 10, i.e. in a position at which bar 15 supports pusher 10 while keeping it in the engaging position 10b. When bar 15 and pusher 10 are not in contact, bar 15 lies in a non-interfering position with pusher 10, i.e. in a position in which bar 15 does not support pusher 10, allowing the latter to lie in the disengaging position 10a due to the weight force acting on arm 12.

As previously mentioned, bar 15 is integrally connected to a rack 16 preferably arranged parallel to bar 15 (i.e. extending in the same extension direction as seat 3). Rack 16 meshes with the toothed wheel 17 by means of which bar 15 may be slid longitudinally. The rack 16, the toothed wheel 17 and the aforesaid second motor work as actuating means for bar 15 between the aforesaid sup- porting and non-interfering positions. Bar 15 and its actuating means work as actuating means for a pusher 10 between the aforesaid engaging position 10b and disengaging position 10a.

With reference to figure 3, when a pusher 10 in the engaging position 10b slides along bar 15 to "descend" therefrom, due to the weight force and the ceasing of the supporting action performed by bar 15, at the descent of the latter pusher 10 rotates about pin 11 (counterclockwise in figures 2 and 3) going to the disengaging position 10a. If pusher 10 in the engaging position 10b is feeding a package 4 along seat 3, the sliding of the package 4 stops when pusher 10 descends from bar 15.

If conveyor 1 comprises a plurality of pushers 10, the extension of bar 15 in longitudinal direction is preferably greater than the mutual distance between two consecutive pushers 10. Therefore, bar 15 can concurrently be in the supporting position for some pushers 10 and in the non-interfering position for the remaining pushers 10.

Incidentally, the presence of bar 15 allows each pusher 10 to travel at least one stretch of seat 3 in the engaging position 10b, i.e. penetrating at least partially seat 3 (as in the current chain conveyors), regardless of the position of the bar with respect to seat 3, by performing a complete turn of the chains 6.

When motor 9 is actuated (i.e. when conveyor 1 is working), bar 15 can be translated along seat 3 regardless of the sliding of the chains 6. The point of the path along seat 3 in which the pushers 10 rotate from the disengaging position 10a to the engaging position 10b (so as to intercept the packages 4 possibly housed in seat 3) and the point of the path along seat 3 in which the pushers 10 rotate from the engaging position 10b to the disengaging position 10a (thus stopping the sliding of the packages 4) can be adjusted.

It is thus possible to interrupt the movement of the packages 4 when they are still housed in seat 3 on conveyor 1. In addition, the mutual distance between the packages 4 when their sliding in seat 3 stops can be adjusted by appropriately translating bar 15 in the direction opposite to the sliding direction of the chains 6 at the upper stretch thereof (i.e., in the figures, by shifting bar 15 from the right leftwards while the chains 6 slide clockwise). More specifically, the slid- ing of the packages 4 in seat 3 can be stopped by positioning them at a mutual distance different from that at which they lie when sliding and that depends on the mutual distance between the pushers 10 (which, as in the current chain conveyors, is not adjustable).

For the purposes of adjusting the translation of bar 15 as a function of the trans- lation of the pushers 10, conveyor 1 comprises, by way of example, a cam (not shown in the figures) rotationally coupled to the shaft 8 of motor 9 and a sensor (not shown in the figures) connected to the control system of conveyor 1 and rotationally coupled to the shaft of the motor which actuates bar 15. By means of the aforesaid sensor, the control system of conveyor 1 can establish whenever the shaft 8 of motor 9 performs a complete turn with respect to the shaft of the motor which actuates bar 15. Preferably, the control system gradually translates bar 15 in the direction opposite to the forward direction of the pushers 10. Even more preferably, when a pusher 10 is about to descend from bar 15, the control system slows down the forward movement of the pushers 10. As a result, the stopping of a package 4 due to the descent of the bar 15 of pusher 10 associated thereto is not instantaneous. Advantageously, if the packages 4 are, for example, open vessels containing liquid substances, the gradual (i.e. not sudden) stopping of the forward movement of the packages 4 prevents an undesired spillage of liquid substances from the aforesaid vessels.

In an alternative embodiment of conveyor 1 (not shown in the figures), each pusher 10 comprises, in addition to wheel 14, a pair of wheels coaxially and freely pivoted to arm 12, preferably close to an end of the latter opposite to the housing hole of pin 11 , and even more preferably coaxially to wheel 14. Similarly to the latter, the aforesaid pair of wheels contributes to arm 12 being heavier than arm 13.

In this alternative embodiment, the conveyor of the invention also comprises a second, preferably rectilinear rail placed under seat 3. Even more preferably, the second rail is arranged parallel to rail 2. Said second rail thus extends in the same extension direction as seat 3. Preferably, the longitudinal extension of the second rail is greater than the mutual distance between two consecutive pushers 10, but smaller than the longitudinal extension of seat 3. Even more prefer- ably, the second rail extends over a stretch of seat 3 starting from the end portion of the conveyor at which one or more packages 4 can be placed in seat 3. In other words, the second rail is preferably missing at the end portion of the conveyor where the packages can be picked from seat 3. The second rail is preferably in intermediate position between the guides of rail 2. Bar 15 is pref- erably interposed between the mutually parallel guides which form said second rail. The latter lies under the guides of rail 2, preferably at the same height at which the bar lies 15, i.e. at a height such as to intercept said pushers 10 when they are in relative motion with respect to said second rail along the upper stretch of the chains 6. More in detail, the second rail lies under the upper stretch of the chains 6 at the lower end of the pushers 10.

When fed by the chains 6, the pushers 10 reach the upper stretch of the chains (in the disengaging position 10a), protrude under the chains 6 so as to come into contact with said second rail at the aforesaid pair of wheels, regardless whether the pushers 10 even come into contact with bar 15 at wheel 14. Con- sidering, by way of example, a pusher 10 that, in the disengaging position 10a, gradually approaches said second rail until striking into it, it can be noted that pusher 10 rotates about pin 11 upon the striking and movement, thus going to the engaging position 10b, i.e. positioning itself with arm 12 arranged almost horizontally over said second rail and arm 13 arranged almost vertically. In this position, the pushers 10 rest on said second rail and are partially housed in seat 3, penetrating the latter with arm 13 through opening 5.

When a pusher 10 is in the engaging position 10b, it rests on bar 15 at wheel 14 and/or on said second rail at said pair of wheels. Said pair of wheels roll on said second rail when motor 9 is actuated (i.e. when pusher 10 and said second rail are in a mutual relative motion in addition to being in contact).

In light of the above, the second rail, in contact with the pushers 10, performs a supporting function in respect to the latter, keeping them in the engaging position 10b.

When a pusher 10 in the engaging position 10b slides along said second rail to descend from the latter, if bar 15 is present, pusher 10 remains in the engaging position 10b due to the supporting action performed by bar 15. If the latter is missing (because it is fully "retracted" between the guides of said second rail), due to the weight force and the ceasing of the supporting action performed by said second rail, at the descent from the latter pusher 10 rotates about pin 11 going to the disengaging position 10a. The sliding of the package 4 stops if pusher 10 in the engaging position 10b is feeding a package 4 along seat 3, when pusher 10 descends from said second rail, in the absence of the support provided by bar 15.

As previously mentioned, if conveyor 1 comprises a plurality of pushers 10, the extension of said second rail in longitudinal direction is preferably greater than the mutual distance between two consecutive pushers 10. Therefore, using the same technology adopted with reference to bar 15, said second rail is concurrently in the supporting position for some pushers 10 and in the non-interfering position for the remaining pushers 10.

The presence of said second rail regardless of the extension of the latter allows each pusher 10 to travel at least one stretch of seat 3 to the engaging position 10b by performing a complete turn of the chains 6.

The second rail and the bar 15 behave, as a whole, as a telescopic supporting structure of the pushers 10. Said telescopic structure has a first fixed end pref- erably placed at the end part of the conveyor where the packages 4 are located in seat 3, and a second end (opposite to the first end) which can translate at the end part of the conveyor where the packages 4 are picked from seat 3. The point of the path along seat 3 in which the pushers 10 rotate from the engaging position 10b to the disengaging position 10a (thus stopping the sliding of the packages 4) can thus be adjusted.

Therefore, in the present embodiment of the conveyor which is the object of the invention, the movement of the packages 4 can also be interrupted when they are still housed in seat 3. In addition, the mutual distance between the packag- es 4 when their sliding in seat 3 stops can be adjusted by appropriately translating bar 15 in the direction opposite to the sliding direction of the chains 6 at the upper stretch thereof. More specifically, the sliding of the packages 4 in seat 3 can be stopped by positioning them at a different mutual distance from that at which they lie when sliding and that depends on the mutual distance between the pushers 10 (which as in the current chain conveyors is not adjustable).

As regards the adjustment of the translation of bar 15 as a function of the translation of the pushers 10, in the present alternative embodiment the conveyor which is the object of the invention also comprises, by way of example, a cam rotationally coupled to the shaft 8 of motor 9 (which actuates the pushers 10) and a sensor always connected to the control system of the conveyor and rotationally coupled to the motor shaft which actuates bar 15.

On the basis of the provided description of a preferred embodiment, it is apparent that changes may be introduced by those skilled in the art without departing from the scope of the invention as defined by the following claims.

Claims

C L A I M S

A conveyor (1 ) of at least one package (4) comprising:

• a seat (3) for at least partially housing and sliding said package (4), said seat (3) being extended in a direction;

• at least one pusher (10), which can be at least partially housed in said seat (3);

• first actuating means (6, 7, 8, 9) for actuating said pusher (10), so that the latter is at least partially housed in said seat (3) and travels along at least one stretch thereof,

said first actuating means (6, 7, 8, 9, 11) comprising:

- at least a first chain (6) extending in the same extension direction as said seat (3);

- first sliding means (7, 8, 9) for sliding said first chain;

- connecting means for connecting said pusher (10) to said first chain (6),

said conveyor (1 ) being characterized in that it comprises:

• second actuating means (15, 16, 17) for actuating said pusher (10) between at least one engaging position (10b), at which said pusher (10) is at least partially housed in said seat (3), and a disengaging position (10a), at which said pusher (10) is not housed in said seat (3),

said connecting means being suitable to allow a displacement of said pusher (10) between said engaging and disengaging positions (10b, 10a).

A conveyor (1 ) according to claim 1 , characterized in that said connecting means comprise a pin (11 ) connected to said first chain (6), said pusher (10) comprising a hole in which said pin (11 ) is at least partially housed so that said pusher (10) can rotate about said pin (11 ).

A conveyor (1) according to claim 2, characterized in that said first two actuating means (6, 7, 8, 9, 11 ) comprise at least a second chain extending in the same extension direction as said seat (3), said first sliding means (7, 8, 9) being sliding means for said first and second chains (6), said pin (11 ) being connected to said first and second chains (6) in an intermediate position therebetween. 4. A conveyor (1) according to claim 2, characterized in that said pusher (10) comprises at least a first and a second arm (12, 13), which are not aligned, said hole being in an intermediate position between said arms (12, 13), said first arm (12) being heavier than said second arm (13) so that said pusher (10) naturally remains in said disengaging position (10a) due to the weight of said first arm.

5. A conveyor (1 ) according to claim 4, characterized in that said second actuating means ( 5, 16, 17) comprise:

- first supporting means (15) for supporting said pusher (10) in said engaging position (10b);

- third means (16, 17) for actuating said first supporting means (15) between at least one supporting position (10b), in which said first supporting means (15) keep said pusher (10) in said engaging position, and a non-interfering position, in which said first supporting means (15) do not support said pusher (10).

6. A conveyor (1) according to claim 5, characterized in that first supporting means (15) extend in the same extension direction as said seat (3).

7. A conveyor (1 ) according to claim 6, characterized in that the extension of said first supporting means (15) in said direction is greater than the mutual distance between two consecutive pushers (10).

8. A conveyor (1 ) according to claim 6 or 7, characterized in that said pusher (10) comprises at least a first wheel (14) pivoted to said first arm (12), said first wheel (14) being suited to roll on said first supporting means (15) when the latter are in said supporting position of said pusher (10).

9. A conveyor (1 ) according to one of the claims from 6 to 8, characterized in that said third actuating means (16, 17) comprise:

> at least one rack (16) extending in the same extension direction as said seat (3), said rack (16) being connected to said first supporting means (15);

> second sliding means (17) of said rack (16).

10. A conveyor according to one of the claims from 5 to 9, characterized in that said second actuating means further comprise: - second supporting means for supporting said pusher in said engaging position.

A conveyor according to claim 10, characterized in that said second supporting means extend in the same extension direction as said seat, the extension of said second supporting means in said direction is greater than the mutual distance between two consecutive pushers and smaller than the extension of said seat in said direction.

A conveyor according to claim 11 , characterized in that said pusher comprises at least a second wheel pivoted to said first arm, said second wheel being suited to roll on said second supporting means.