CRISPO, Romeo (Via Risorgimento 6, Pero, I-20010, IT)
| Claims.
1). A machine for assembly of plastic zip fasteners, wherein it comprises: means for gripping (7) two continuous flaps (3) of a zip (2) in order to superpose the flaps (3) and keep the flaps (3) in said position; means for cutting (12) for partially cutting the flaps (3) at a hooking portion (4) thereof; means for applying (13) a cursor (5) for coupling the flaps (3). 2). The machine of claim 1, wherein the means for applying (13) comprise at least a moving organ (14) of the cursor (5) for bringing the cursor (5) in proximity of the means for gripping (7).
3). The machine of claim 2, wherein the moving organ (14) comprises a mobile pliers (15) for bringing the cursor (5) to face the hooking portions (4). 4). The machine of claim 3, wherein the pliers (15) comprises two counter- posed fingers (16) which exhibit an L-shape; the fingers (16) being reciprocally mobile in distancing and nearing to one another. 5). The machine of claim 3 or 4, wherein the pliers (15) comprises a gripping head (17) for receiving and housing the cursor (5).
6). The machine of claim 5, wherein the gripping head (17) of the pliers (15) exhibits at least two parallel surfaces (17a, 17b) which are each located on a respective finger (16) and which define a housing chamber (18) for the cursor (5). 7). The machine of any one of claims from 3 to 6, wherein the pliers (15) comprise a preferably pneumatic first actuator (19) for moving the pliers (15) between a first position in which the cursor (5) is fed to the pliers (15) and a second position in which the cursor (5) is applied.
8). The machine of any one of claims from 4 to 7, wherein the pliers (15) comprises a preferably pneumatic second actuator (20), for moving the fingers (16) in a reciprocally nearing/distancing direction.
9). The machine of any one of the preceding claims, further comprising a drawing device (25) for moving the flaps (3) with respect to the cursor (5).
10). The machine of claim 9, wherein the drawing device (25) comprises a pair of rollers (26) which are opposite and counter-rotating; the rollers (26) exhibiting respective rotation axes (26a) which are arranged perpendicularly to an advancement direction (D) of the flaps (3).
11). The machine of any one of the preceding claims, wherein the means for gripping (7) comprise a press (8).
12). The machine of claim 11 , wherein the press (8) comprises a first plate (9) which is fixed and a second plate (10) which is mobile in nearing the first plate (9) in order to keep two portions of the flaps (3) superposed.
13). The machine of claim 11, wherein the press (8) comprises a first plate (9) and a second plate (10) which are mobile in nearing to one another in order to maintain the two portions of flaps in a reciprocally superposed position.
14). The machine of any one of the preceding claims, further comprising a hook (21) for deviating a portion of the flaps (3) located downstream of the means for cutting (12); the hook (21) being rotating mobile between a lowered non-operative position and a raised operative position.
15). The machine of claim 14, wherein the hook (21) is located in proximity of the means for gripping (7), preferably upstream thereof. 16). The machine of claim 14 or 15, wherein the hook (21) further comprises a cogwheel (22) which is connected thereto and a rack (23) which is associated to the cogwheel (22) in order to rotate the hook (21).
17). The machine of any one of claims from 3 to 16, further comprising means for supplying (27) the cursor (5) to the pliers (15).
18). The machine of claim 17, wherein the means for supplying (27) comprise: a container (28) for housing a plurality of cursors (5); a loading station (32) for inserting the cursor (5) in the pliers (15); and a preferably vertical transfer conduit (30), for transferring the cursor (5) from the container (28) to the loading station (32).
19). The machine of claim 18, wherein the loading station (32) comprises a rotatable seating (33) located at an outlet end (30a) of the transfer conduit
(30); the loading station (32) further comprising a pusher (34) for inserting each cursor (5) in the pliers (15).
20). The machine of claim 19, wherein the loading station (32) further comprises means for orientating (36) for rotating the rotating seating (33) and for orientating the cursor (5).
21). The machine of claim 20, wherein the means for orientating (36) comprise a cam (37) connected to the rotating seating (33) by means of a shaft (38).
22). The machine of claim 21, wherein the means for orientating (36) comprise a secondary pusher (39) which acts on the cam (37) to set the cam
(37) in rotation and for rotating the rotating seating (33). -1-
Description A Machine for Assembling Plastic Zip Fasteners.
Technical Field
The invention relates to a machine for assembling plastic zip fasteners.
In particular the invention relates to assembly of zip fasteners which are subsequently welded onto bags made of plastic material.
Background Art Plastic zip fasteners are known which comprise a pair of plastic flaps to which respective counter-shaped profiles are associated, which flaps can be hooked to one another in order to close the zip. The coupling and relative uncoupling between the profiles can be realised by a cursor internally of which the profiles run. Inside the cursor two distinct channels are defined which converge into a single channel. In this way, when it runs along the zip profiles the cursor causes the separated profiles to conjoin in the single channel and to hook up reciprocally.
For assembly of the zips, methods are known which comprise a total cut of portions of flap and their coupling by manual insertion of the relative cursor. In this way, the hinges are assembled to one another.
In a further method, a pair of flaps is coupled by manually inserting a determined number of cursors which are then reciprocally distanced. In this method the thus-assembled zips are then manually cut.
In a further used process, equidistanced and partial cuts are made on the flaps in proximity of the counter-shaped profiles and a respective cursor is inserted in each portion defined by the cuts. In this way a determined number of zips are assembles which are maintained reciprocally connected inasmuch as the cut is only partial. -2-
Disadvantageously, the methods used include manual performance of one or more of the stages of manufacture.
Consequently the methods used are distinguished by very long realisation times and are not able to guarantee high productivity speeds. Further, the manual performing of some stages leads to a inhomogeneous production and a high number of rejects due to poor precision or errors in manufacture.
The aim of the present invention is to provide a machine for assembling zip fasteners made of plastic which are free of the above-described drawbacks. In particular it is an aim of the present invention to provide a machine for assembling zip fasteners which realises zip assembly continuously and in an automatic process.
Further, an aim of the present invention is to provide a machine for assembling plastic zip fasteners which guarantees high production speeds. A further aim of the present invention is to provide a machine for assembling plastic zip fasteners thanks to which it is possible to maintain a constant quality of the assembled zips and numbers of rejects due to production errors can be limited.
Further characteristics and advantages will better emerge from the detailed description that follows of a machine for plastic zip assembly according to what is set out in one or more of the accompanying figures of the drawings.
The description will now be made with reference to the accompanying figures of the drawings, provided purely by way of non-limiting example, and in which: figure 1 is a perspective view of a machine for assembly of plastic zip fasteners according to the present invention; figure 2 is a first perspective view of a detail of the machine of figure 1; -3-
figure 2a is a view of a detail of figure 2; figure 3 is a second perspective view of the detail of figure 2; figure 4 is a perspective view of a further detail of the machine of figure 1; figure 5 is a section view of the detail of figure 4; figure 6 is a perspective view of a third detail of the machine of figure 1 ; and figure 7 is a view of an example of a plastic zip fastener. Disclosure of Invention
With reference to the figures of the drawings, 1 denotes in its entirety the machine for assembly plastic zip fasteners of the present invention. In particular, figure 7 illustrates and example of a plastic zip fastener assembled by the machine 1. In detail the zip 2 comprises two flaps 3 and a hooking portion 4 connected to each flap 3. The hooking portions 4 are shaped such that they solidly and reversibly join, one in another. To realise the coupling between the opposite hooking portions 4, the zip 2 further comprises a cursor 5, internally of which two distinct channels are afforded, which converge into a single channel in order to couple the two flaps 3. Figure 1 shows the machine 1 mounted on a support frame S. Further, a further frame S' is visible in the figure for supporting a covering casing (not illustrated). The machine 1 develops on a support plate 6 and comprises means for gripping 7 the continuous flaps 3 in order to keep them in a superposed position. In more detail, the means for gripping 7 comprise a press 8 which is necessary for coupling the flaps 3 such that the respective hooking portions 4 lie one above another. However, the press 8 limits the pressure exerted on the flaps 3 in order to prevent the hooking portions 4 from coupling to one another. -4-
The press 8 comprises a first plate 9 and a second plate 10 which are mobile in nearing to one another.
In a second embodiment the press 8 comprises a fixed first plate 9 and a second plate 10 which is mobile in nearing the fixed first plate 9. The press 8 further comprises a pneumatic actuator 11 which is operatively connected to the mobile second plate 10.
The machine 1 further comprises means for cutting 12 for making a partial cut on the flaps 3 and in particular at each hooking portion 4. In this way, free ends of the hooking portions 4 are created, By way of example, the means for cutting 12 can comprise a mobile cutter
12a.
The means for cutting 12 are located in proximity of the press 8, preferably upstream of the press 8, and are active when the press 8 is in the closed position. Further, the machine 1 comprises means for applying 13 the cursor 5 to the flaps 3.
In more detail, the means for applying 13 comprise at least a movement organ
14 of the cursor 5. In more detail still, the at least a moving organ 14 comprises a mobile pliers 15 for facing the cursor 5 to the hooking portions 4. In particular, the pliers 15 faces the cursor 5 at the free ends of the hooking portions 4.
The pliers 15 comprises two opposite fingers 16, each being L-shaped. The fingers 16 are reciprocally mobile in nearing and/or distancing.
The pliers 15 further comprises a gripping head 17 for receiving and housing the cursor 5. In more detail, the gripping head 17 exhibits two parallel surfaces 17a, 17b which are each located on a respective finger 16 of the pliers 15. -5-
In particular, the parallel surfaces 17a, 17b at least partially define a housing chamber 18 for the cursor 5.
The parallel surfaces 17a, 17b enter into contact with the cursor 5 and keep it tightly in the gripping head 17. Further, the gripping head 17 exhibits two inclined surfaces 17c, 17d which each start from a respective parallel surface 17a, 17b and diverge. In this way, the housing chamber 18 exhibits a riser guide which enables easy introduction of the cursor 5 into the pliers 15.
The pliers 15 comprises a first actuator 19 which enables the pliers 15 to move along a straight trajectory between a first position, in which the cursor 5 is introduced in the chamber 18 of the pliers 15, and a second position, in which the cursor 5 faces the hooking portions 4.
The first actuator 19 is preferably a pneumatic actuator. In a further embodiment, the first actuator 19 can be a hydraulic or electric actuator. The pliers 15 further comprise a second actuator 20 which enables the filters
16 of the pliers 15 to move in reciprocal distancing and/or nearing.
The second actuator 20 is preferably a pneumatic actuator. In an alternative embodiment, the second actuator 20 can be a hydraulic or electric actuator.
The machine 1 further comprises a hook 21 which is necessaiy for deviating a portion of the flaps 3 located downstream of the means for cutting 12.
Further, the hook 21 is located in proximity of the means for gripping, preferably upstream of the means for gripping 7. The hook 21 is rotatably mobile between a non-operative position (represented by a continuous line in figure 6) in which it is lowered and an operative position (represented by a broken line in figure 6) in which the hook 21 is in a raised position.
The hook 21 further comprises a cogwheel 22 which is rigidly connected to the hook 21 itself. The cogwheel 22 is enmeshed on a rack 23 which, as it -6-
moves linearly, causes a rotation of the cogwheel 22 and the hook 21. The rack 23 is powered by a respective actuator 24 which, in the described embodiment, is pneumatic. In an embodiment which is not described, the actuator 24 can be hydraulic or electric. In use, when the two flaps 3 are comprised between the plates 9, 10 of the press 8, the means for cutting 11 make the partial cut of the flaps 3. Then the hook 21 is brought into its operative position. In this way, the hook 21 deviates the portion of the flaps 3 downstream of the cut in order that the free ends of the hooking portions 21 can be brought into contact with the cursor 5. The cursor 5 is brought to face the free ends by the pliers 15.
The machine further comprises a drawing device 25 for moving the flaps 3 with respect to the cursor 5. In particular, the device 25 comprises a pair of rollers 26 which are opposite and counter-rotating. In more detail, the pair of rollers 26 exhibits respective rotation axes 26a which are arranged perpendicularly to an advancement direction D of the flaps 3.
In the described embodiment, the pair of rollers 26 is arranged upstream of the means for gripping 7. In an alternative embodiment, the pair of rollers 26 can also be arranged downstream of the means for gripping 7. The machine 1 further comprises means for supplying 27 the cursor 5 to the pliers 15. The means for supplying 27 comprise a container 28 housing a plurality of cursors 5 which are progressively supplied to the pliers 15. This container 28 is a vibrating container of known type. The vibration brings the cursors 5 up to a horizontal guide 29 connected to a preferably vertical transfer conduit 30. The conduit 30 internally exhibits a shaped guide 31 which enables the cursors 5 to reach a loading station 32 by force of gravity.
The loading station 32 is necessary for inserting the cursor 5 into the housing chamber 18 of the pliers 15. -7-
The loading station 32 comprises a rotating seating 33 located at an outlet end
30a of the transfer conduit 30 and a pusher 34 which pushes the cursor 5 located in the seating 33 internally of the housing chamber 18 of the pliers 15.
The pusher 34 is moved by a respective actuator 35 which in the described embodiment is a pneumatic actuator.
The loading station 32 further comprises means for orientating 36 for rotating the rotating seating 33. The seating 33 is rotatable in order to cause a rotation of the cursor 5, and thus for changing the orientation of the cursor 5.
The means for orientating 36 comprise a cam 37 which is connected to the rotating seating 33 by means of a shaft 38. The cam 37 is rotated by a secondary pusher 39 which enters into contact with the cam 37 at a lower height than the rotation point thereof.
The machine 1 further comprises a winding roller 40 about which the partially-cut flaps 3 are wound, coupled by the cursor 5. In an embodiment which is not illustrated, the winding roller 40 can constitute the drawing device 25.
The invention attains the set aims and offers important advantages.
With the machine 1 of the invention, all zip assembly states are automated.
Consequently the machine 1 enables high production speeds to be attained, with a considerable saving in terms of time.
Further, the machine 1 enables continuous and constant zip production to be set up. The quality of the zips 2 is constant and the production defects found in the prior art are considerably reduced. -8-
Claims.
1). A machine for assembly of plastic zip fasteners, wherein it comprises: means for gripping (7) two continuous flaps (3) of a zip (2) in order to superpose the flaps (3) and keep the flaps (3) in said position; means for cutting (12) for partially cutting the flaps (3) at a hooking portion (4) thereof; means for applying (13) a cursor (5) for coupling the flaps (3). 2). The machine of claim 1, wherein the means for applying (13) comprise at least a moving organ (14) of the cursor (5) for bringing the cursor (5) in proximity of the means for gripping (7).
3). The machine of claim 2, wherein the moving organ (14) comprises a mobile pliers (15) for bringing the cursor (5) to face the hooking portions (4). 4). The machine of claim 3, wherein the pliers (15) comprises two counter- posed fingers (16) which exhibit an L-shape; the fingers (16) being reciprocally mobile in distancing and nearing to one another. 5). The machine of claim 3 or 4, wherein the pliers (15) comprises a gripping head (17) for receiving and housing the cursor (5).
6). The machine of claim 5, wherein the gripping head (17) of the pliers (15) exhibits at least two parallel surfaces (17a, 17b) which are each located on a respective finger (16) and which define a housing chamber (18) for the cursor (5). -9-
7). The machine of any one of claims from 3 to 6, wherein the pliers (15) comprise a preferably pneumatic first actuator (19) for moving the pliers (15) between a first position in which the cursor (5) is fed to the pliers (15) and a second position in which the cursor (5) is applied.
8). The machine of any one of claims from 4 to 7, wherein the pliers (15) comprises a preferably pneumatic second actuator (20), for moving the fingers (16) in a reciprocally nearing/distancing direction.
9). The machine of any one of the preceding claims, further comprising a drawing device (25) for moving the flaps (3) with respect to the cursor (5).
10). The machine of claim 9, wherein the drawing device (25) comprises a pair of rollers (26) which are opposite and counter-rotating; the rollers (26) exhibiting respective rotation axes (26a) which are arranged perpendicularly to an advancement direction (D) of the flaps (3).
11). The machine of any one of the preceding claims, wherein the means for gripping (7) comprise a press (8).
12). The machine of claim 11 , wherein the press (8) comprises a first plate (9) which is fixed and a second plate (10) which is mobile in nearing the first plate (9) in order to keep two portions of the flaps (3) superposed.
13). The machine of claim 11, wherein the press (8) comprises a first plate (9) and a second plate (10) which are mobile in nearing to one another in order to maintain the two portions of flaps in a reciprocally superposed position.
14). The machine of any one of the preceding claims, further comprising a hook (21) for deviating a portion of the flaps (3) located downstream of the means for cutting (12); the hook (21) being rotating mobile between a lowered non-operative position and a raised operative position.
15). The machine of claim 14, wherein the hook (21) is located in proximity of the means for gripping (7), preferably upstream thereof. -10-
16). The machine of claim 14 or 15, wherein the hook (21) further comprises a cogwheel (22) which is connected thereto and a rack (23) which is associated to the cogwheel (22) in order to rotate the hook (21).
17). The machine of any one of claims from 3 to 16, further comprising means for supplying (27) the cursor (5) to the pliers (15).
18). The machine of claim 17, wherein the means for supplying (27) comprise: a container (28) for housing a plurality of cursors (5); a loading station (32) for inserting the cursor (5) in the pliers (15); and a preferably vertical transfer conduit (30), for transferring the cursor (5) from the container (28) to the loading station (32).
19). The machine of claim 18, wherein the loading station (32) comprises a rotatable seating (33) located at an outlet end (30a) of the transfer conduit
(30); the loading station (32) further comprising a pusher (34) for inserting each cursor (5) in the pliers (15).
20). The machine of claim 19, wherein the loading station (32) further comprises means for orientating (36) for rotating the rotating seating (33) and for orientating the cursor (5).
21). The machine of claim 20, wherein the means for orientating (36) comprise a cam (37) connected to the rotating seating (33) by means of a shaft (38).
22). The machine of claim 21, wherein the means for orientating (36) comprise a secondary pusher (39) which acts on the cam (37) to set the cam
(37) in rotation and for rotating the rotating seating (33). |
Description A Machine for Assembling Plastic Zip Fasteners.
Technical Field
The invention relates to a machine for assembling plastic zip fasteners.
In particular the invention relates to assembly of zip fasteners which are subsequently welded onto bags made of plastic material.
Background Art Plastic zip fasteners are known which comprise a pair of plastic flaps to which respective counter-shaped profiles are associated, which flaps can be hooked to one another in order to close the zip. The coupling and relative uncoupling between the profiles can be realised by a cursor internally of which the profiles run. Inside the cursor two distinct channels are defined which converge into a single channel. In this way, when it runs along the zip profiles the cursor causes the separated profiles to conjoin in the single channel and to hook up reciprocally.
For assembly of the zips, methods are known which comprise a total cut of portions of flap and their coupling by manual insertion of the relative cursor. In this way, the hinges are assembled to one another.
In a further method, a pair of flaps is coupled by manually inserting a determined number of cursors which are then reciprocally distanced. In this method the thus-assembled zips are then manually cut.
In a further used process, equidistanced and partial cuts are made on the flaps in proximity of the counter-shaped profiles and a respective cursor is inserted in each portion defined by the cuts. In this way a determined number of zips are assembles which are maintained reciprocally connected inasmuch as the cut is only partial.
Disadvantageously, the methods used include manual performance of one or more of the stages of manufacture.
Consequently the methods used are distinguished by very long realisation times and are not able to guarantee high productivity speeds. Further, the manual performing of some stages leads to a inhomogeneous production and a high number of rejects due to poor precision or errors in manufacture.
The aim of the present invention is to provide a machine for assembling zip fasteners made of plastic which are free of the above-described drawbacks. In particular it is an aim of the present invention to provide a machine for assembling zip fasteners which realises zip assembly continuously and in an automatic process.
Further, an aim of the present invention is to provide a machine for assembling plastic zip fasteners which guarantees high production speeds. A further aim of the present invention is to provide a machine for assembling plastic zip fasteners thanks to which it is possible to maintain a constant quality of the assembled zips and numbers of rejects due to production errors can be limited.
Further characteristics and advantages will better emerge from the detailed description that follows of a machine for plastic zip assembly according to what is set out in one or more of the accompanying figures of the drawings.
The description will now be made with reference to the accompanying figures of the drawings, provided purely by way of non-limiting example, and in which: figure 1 is a perspective view of a machine for assembly of plastic zip fasteners according to the present invention; figure 2 is a first perspective view of a detail of the machine of figure 1;
figure 2a is a view of a detail of figure 2; figure 3 is a second perspective view of the detail of figure 2; figure 4 is a perspective view of a further detail of the machine of figure 1; figure 5 is a section view of the detail of figure 4; figure 6 is a perspective view of a third detail of the machine of figure 1 ; and figure 7 is a view of an example of a plastic zip fastener. Disclosure of Invention
With reference to the figures of the drawings, 1 denotes in its entirety the machine for assembly plastic zip fasteners of the present invention. In particular, figure 7 illustrates and example of a plastic zip fastener assembled by the machine 1. In detail the zip 2 comprises two flaps 3 and a hooking portion 4 connected to each flap 3. The hooking portions 4 are shaped such that they solidly and reversibly join, one in another. To realise the coupling between the opposite hooking portions 4, the zip 2 further comprises a cursor 5, internally of which two distinct channels are afforded, which converge into a single channel in order to couple the two flaps 3. Figure 1 shows the machine 1 mounted on a support frame S. Further, a further frame S' is visible in the figure for supporting a covering casing (not illustrated). The machine 1 develops on a support plate 6 and comprises means for gripping 7 the continuous flaps 3 in order to keep them in a superposed position. In more detail, the means for gripping 7 comprise a press 8 which is necessary for coupling the flaps 3 such that the respective hooking portions 4 lie one above another. However, the press 8 limits the pressure exerted on the flaps 3 in order to prevent the hooking portions 4 from coupling to one another.
The press 8 comprises a first plate 9 and a second plate 10 which are mobile in nearing to one another.
In a second embodiment the press 8 comprises a fixed first plate 9 and a second plate 10 which is mobile in nearing the fixed first plate 9. The press 8 further comprises a pneumatic actuator 11 which is operatively connected to the mobile second plate 10.
The machine 1 further comprises means for cutting 12 for making a partial cut on the flaps 3 and in particular at each hooking portion 4. In this way, free ends of the hooking portions 4 are created, By way of example, the means for cutting 12 can comprise a mobile cutter
12a.
The means for cutting 12 are located in proximity of the press 8, preferably upstream of the press 8, and are active when the press 8 is in the closed position. Further, the machine 1 comprises means for applying 13 the cursor 5 to the flaps 3.
In more detail, the means for applying 13 comprise at least a movement organ
14 of the cursor 5. In more detail still, the at least a moving organ 14 comprises a mobile pliers 15 for facing the cursor 5 to the hooking portions 4. In particular, the pliers 15 faces the cursor 5 at the free ends of the hooking portions 4.
The pliers 15 comprises two opposite fingers 16, each being L-shaped. The fingers 16 are reciprocally mobile in nearing and/or distancing.
The pliers 15 further comprises a gripping head 17 for receiving and housing the cursor 5. In more detail, the gripping head 17 exhibits two parallel surfaces 17a, 17b which are each located on a respective finger 16 of the pliers 15.
In particular, the parallel surfaces 17a, 17b at least partially define a housing chamber 18 for the cursor 5.
The parallel surfaces 17a, 17b enter into contact with the cursor 5 and keep it tightly in the gripping head 17. Further, the gripping head 17 exhibits two inclined surfaces 17c, 17d which each start from a respective parallel surface 17a, 17b and diverge. In this way, the housing chamber 18 exhibits a riser guide which enables easy introduction of the cursor 5 into the pliers 15.
The pliers 15 comprises a first actuator 19 which enables the pliers 15 to move along a straight trajectory between a first position, in which the cursor 5 is introduced in the chamber 18 of the pliers 15, and a second position, in which the cursor 5 faces the hooking portions 4.
The first actuator 19 is preferably a pneumatic actuator. In a further embodiment, the first actuator 19 can be a hydraulic or electric actuator. The pliers 15 further comprise a second actuator 20 which enables the filters
16 of the pliers 15 to move in reciprocal distancing and/or nearing.
The second actuator 20 is preferably a pneumatic actuator. In an alternative embodiment, the second actuator 20 can be a hydraulic or electric actuator.
The machine 1 further comprises a hook 21 which is necessaiy for deviating a portion of the flaps 3 located downstream of the means for cutting 12.
Further, the hook 21 is located in proximity of the means for gripping, preferably upstream of the means for gripping 7. The hook 21 is rotatably mobile between a non-operative position (represented by a continuous line in figure 6) in which it is lowered and an operative position (represented by a broken line in figure 6) in which the hook 21 is in a raised position.
The hook 21 further comprises a cogwheel 22 which is rigidly connected to the hook 21 itself. The cogwheel 22 is enmeshed on a rack 23 which, as it
moves linearly, causes a rotation of the cogwheel 22 and the hook 21. The rack 23 is powered by a respective actuator 24 which, in the described embodiment, is pneumatic. In an embodiment which is not described, the actuator 24 can be hydraulic or electric. In use, when the two flaps 3 are comprised between the plates 9, 10 of the press 8, the means for cutting 11 make the partial cut of the flaps 3. Then the hook 21 is brought into its operative position. In this way, the hook 21 deviates the portion of the flaps 3 downstream of the cut in order that the free ends of the hooking portions 21 can be brought into contact with the cursor 5. The cursor 5 is brought to face the free ends by the pliers 15.
The machine further comprises a drawing device 25 for moving the flaps 3 with respect to the cursor 5. In particular, the device 25 comprises a pair of rollers 26 which are opposite and counter-rotating. In more detail, the pair of rollers 26 exhibits respective rotation axes 26a which are arranged perpendicularly to an advancement direction D of the flaps 3.
In the described embodiment, the pair of rollers 26 is arranged upstream of the means for gripping 7. In an alternative embodiment, the pair of rollers 26 can also be arranged downstream of the means for gripping 7. The machine 1 further comprises means for supplying 27 the cursor 5 to the pliers 15. The means for supplying 27 comprise a container 28 housing a plurality of cursors 5 which are progressively supplied to the pliers 15. This container 28 is a vibrating container of known type. The vibration brings the cursors 5 up to a horizontal guide 29 connected to a preferably vertical transfer conduit 30. The conduit 30 internally exhibits a shaped guide 31 which enables the cursors 5 to reach a loading station 32 by force of gravity.
The loading station 32 is necessary for inserting the cursor 5 into the housing chamber 18 of the pliers 15.
The loading station 32 comprises a rotating seating 33 located at an outlet end
30a of the transfer conduit 30 and a pusher 34 which pushes the cursor 5 located in the seating 33 internally of the housing chamber 18 of the pliers 15.
The pusher 34 is moved by a respective actuator 35 which in the described embodiment is a pneumatic actuator.
The loading station 32 further comprises means for orientating 36 for rotating the rotating seating 33. The seating 33 is rotatable in order to cause a rotation of the cursor 5, and thus for changing the orientation of the cursor 5.
The means for orientating 36 comprise a cam 37 which is connected to the rotating seating 33 by means of a shaft 38. The cam 37 is rotated by a secondary pusher 39 which enters into contact with the cam 37 at a lower height than the rotation point thereof.
The machine 1 further comprises a winding roller 40 about which the partially-cut flaps 3 are wound, coupled by the cursor 5. In an embodiment which is not illustrated, the winding roller 40 can constitute the drawing device 25.
The invention attains the set aims and offers important advantages.
With the machine 1 of the invention, all zip assembly states are automated.
Consequently the machine 1 enables high production speeds to be attained, with a considerable saving in terms of time.
Further, the machine 1 enables continuous and constant zip production to be set up. The quality of the zips 2 is constant and the production defects found in the prior art are considerably reduced.