Device for postitioning progessively forming can ends on a forming apparatus

Abstract

 The stock shells positioning device is put in a conversion press of stock shells (2) into covers.
This includes a lower die shoe base (1) substantially horizontal, supporting a plurality of lower pressing stations (3), an upper die shoe base (11), that supports at the bottom a plurality of upper pressing stations (13), a continuous belt (6) for transferring said shells (2) and a plurality of pushers (20), joined to the upper die shoe base (11), acting on said continuous belt (6).
The positioning device (30) includes a fixed frame (31), assembled on the lower die shoe base (1), externally to lower pressing stations (3); a set of plates (33), fixed at the top of the frame (31); elastic striker means (35), joined with the lower die shoe base (1) in correspondence of the pushers (20), fit to support the upper branch (6a) of the continuous belt (6), and to slide vertically in phase relationship with the operating of the upper die shoe base (13).

Description

[0001] The present invention relates to conversion presses.

[0002] Particularly the invention concerns a positioning device for stock shells in conversion presses fit for converting such shells into easy-open covers used as closing ends for drink and food cans and the like, although it is understood that such invention is also applicable to presses for the working stocks of different kinds.

[0003] Conversion presses for semi-raw shells are known, including fixtures designed for converting such shells into easy-open covers, by virtue of the a tab application that allows the opening of the cover.

[0004] Known presses generally include a bed supporting lateral uprights on which is fastened, by means of tie rods extending through the uprights, a crown that generally supports the main drive means of the press motion members.

[0005] Sliding support guides for a ram, which supports the tooling of the press upper die shoe, are connected to the uprights.

[0006] These tools are fit to co-operate with correspondent tools of a lower die shoe, supported by the bed, so forming a series of work stations for the shells.

[0007] These latter are generally placed in succession in housings of a conveyor belt, that carries the same through the press dies, moving them station by station, so allowing the progressive shell conversion into covers by means of cyclical stroke of the upper die shoe onto the lower one.

[0008] Such conveyor belt generally slides on a seal box in which vacuum has been made, so as to hold the shells positioned in their housings.

[0009] The main disadvantage of prior presses is that the cyclical motion of upper dies onto the lower dies causes shell arrangement problems, when these shells are carried from a station to the following one.

[0010] Moreover the shells, apart from to be moved longitudinally, require also to be moved in vertical direction for avoiding that the shells crawl on the lower tools during their motion from a station to the following one.

[0011] Devices based on using a vacuum box, that allows the shells to remain in the seats where they are housed, have been proposed.

[0012] In such devices however the vertical motion is made only by means of simple inflexion of the conveyor belt, of semi-rigid material, under the action of the upper tools pushing the shells, and therefore also the conveyor belt toward the lower tools.

[0013] This solution does not resolve completely the shell arrangement and centering problems with consequent possibilities that the shells are moved from the centered position so getting formed covers of poor quality.

[0014] The main object of the present invention is therefore to propose a positioning device for stock shells in a conversion press that allows the same to be centered in the seats of the conveyor belt during the shell working cycle.

[0015] Further object of the present invention is to propose a device of easy realization and reliable operation and maintenance.

[0016] The above said objects are reached with a device for positioning stock shells in a conversion press carried out according with claim 1.

[0017] The features of the present invention are underlined in the follow with reference to the attach drawing tables, where:

• figure 1 shows a top view of the positioning device according to the present invention;
• figure 2 shows a top view of the same device, according to a different horizontal plane;
• figure 3 shows schematically a side view of the device in the preceding figures in a position of shell movement;
• figure 4 shows the same view of figure 3, in an operative position.

[0018] With reference to figures from 1 to 4, numeral 30 indicates a device for positioning stock shells 2 in a conversion press 100 of such shells 2 into easy-open covers for drink cans or generally food cans.

[0019] Such press 100, whose structure and general opoeration are substantially known, is provided with a lower die shoe base 1, substantially horizontal, fixed to a bed of the same press in known manner. Such lower die shoe base 1 is constituted by a lower die shoe plate 1a overlapped by a supporting station plate 1b.

[0020] The lower die shoe base 1 supports a plurality of lower pressing stations 3, placed consecutively on two lines slightly staggered. It is clear that both the line number and the staggered disposition of aforesaid lower pressing stations 3 is made in this embodiment only as example.

[0021] The press 100 has also an upper die shoe base 11, substantially horizontal too, which overhangs the lower die shoe base 1, and is constituted by an upper die shoe plate 11a and an upper station plate 11b, fastened thereto. This last support at the bottom a plurality of upper pressing stations 13, placed in axle with the corresponding lower pressing stations 3 and fit to made the progressive conversion of shells 2 into correspondent covers.

[0022] The upper die shoe base is driven in vertical direction between a lifted position A of shells 2 movement, in which the upper pressing stations 13 are lifted from lower pressing stations 3 and a lowered position B of the same shells 2 conversion, in which the upper pressing stations 13 are in contact with lower pressing stations 3.

[0023] The press 100 has also a continuous belt 6 of the aforesaid shells 2 movement, driven step by step, by known members of the same press 100, according to a feed direction W (figure 1), in phase relationship with the operation of said upper die shoe base 11. The upper branch 6a of the continuous belt 6 overhangs the lower pressing stations 3 and is designed for carrying the shells 2 in sequence through the following pressing stations 3 of the press 100.

[0024] A plurality of pushers 20 is associated with the upper die shoe base 11, at both sides of each aforesaid upper pressing stations 13. Such pushers 20 are movable together with the upper die shoe base 11, and are designed to interest the continuous belt 6, when the same base is in the lowered position B, for forcing the lowering of the continuous belt 6 and for setting in such a way each of the shells 2 at the corresponding lower pressing station 3.

[0025] The positioning device 30 of the invention is substantially associated with the lower die shoe base 1.

[0026] It comprises firstly a fixed frame 31, assembled on the lower station plate 1, perimetrically to the of lower pressing stations 3.

[0027] At the upper part of the frame 31 a set of plates 33 is fixed placed substantially horizontal immediately over the upper branch 6a transport plan of the continuous belt 6. In the described embodiment the plates 33 include a first plate 43, a median plate 53, consecutive thereto, and a terminal plate 63, placed after the median plate 53 in comparison with said feed direction W of the shells 2.

[0028] The median 53 and terminal 63 plates are besides spaced, for allowing the crossing of a tab feeder belt 64, according known ways. This latter is used in correspondence of suitable pressing stations 3,13 for fixing relative tabs 2a to the shells 2.

[0029] The plates 33 are provided with a plurality of circular housings 33a in correspondence of the lower 3 and upper 13 pressing stations, and of a plurality of slots 33b in correspondence of the pushers 20. They are destined to co-operate with the lower die shoe base 1, the frame 31 and the shells 2 for defining a vacuum box 34. The belt 6 therefore slides substantially in the upper part of the aforesaid vacuum box 34. This last is kept continually in depression by not illustrated vacuum-operated means.

[0030] In correspondence with the pushers 20, elastic striker means 35 are associated with the lower die shoe base 1, fit to support the upper branch 6a of the continuous belt 6. They can slide vertically, in phase relationship with the operation of the upper die shoe base 13, between a lifted position C (see figure 3) and a lowered position D (figure 4), in which said shells 2 are stopped on the respective lower pressing stations 3.

[0031] The aforesaid elastic striker means 35 are constituted by a plurality of longitudinal bars 36, substantially horizontal and parallel, extending for part of lower pressing stations extension 3. For constructive simplicity, two or more longitudinal bars 36 can be placed consecutively on the same axle. They are associated at the bottom to correspondent elastic reaction members 37, embedded in said lower die shoe base 1.

[0032] These latter are constituted preferably by axial action springs, opportunely calibrates in such a way to allow the aforesaid longitudinal bars 36 to withdraw by means of the pusher 20 action, with the interposition of the continuous belt 6.

[0033] A plurality of splined blocks 38, placed at the top of said longitudinal bars 36, drive these latter during their vertical translation between the lifted C and lowered D positions.

[0034] The operation of the shells 2 positioning device will be in the follow described starting from a situation, illustrated in figure 3, in which the die shoe base 11 and the relative upper pressing stations 13 are in the lifted position A.

[0035] In this situation the longitudinal bars are in the respective lifted position C, and support the continuous belt 6 in such a way that the shells 2 carried therefrom are slightly lifted in comparison with the respective lower pressing station 3. In this way the same shells can be moved by operating the continuous belt 6 between following pressing stations 3,13, without interfering with the lower pressing stations 3.

[0036] The vacuum box 34 is constantly kept in depression, in such a way that the shells 2 are always kept in the ideal pressing position.

[0037] When the shells 2 are positioned above the respective pressing stations 3,13, the upper die shoe base 11 is brought from the lifted position A to the lowered B one. During such excursion, the pushers 20 pass through the slots 33b of the plates 33, and contact with the continuous belt 6 placed thereunder. Therefore the pushers 20 forces the longitudinal bars 36 into a down translation, overcoming the elastic reaction of the axial springs 37, until said longitudinal bars 36 reach their lowered position D.

[0038] In such a situation the shells 2 are compressed between the respective lower 3 and upper 13 pressing stations, and are progressively converted into correspondent covers.

[0039] After a prefixed time period, the upper die shoe base 11 is brought into its lifted position A, so restoring the initial conditions.

[0040] The main advantage of the present invention is therefore to provide a stock shells positioning device for conversion presses allowing the same shells to remain centered in the seats of the conveyor belt during the working cycle of the same shells, and reducing the number of parts in movement.

[0041] Further advantage of the present invention is to provide a device of easy realization and reliable operation and maintenance.

[0042] The present invention has been obviously described, with reference to attached drawings, only as an example, not limitative, and it can be carried out within the object defined by the following claims.

Claims

1. Stock shells positioning device in a conversion press of stock shells (2) into easy-open covers for drink or generic food cans, with said press (100) comprising:

- a lower die shoe base (1) substantially horizontal, supporting a plurality of lower pressing stations (3) placed consecutively;

- an upper die shoe base (11), substantially horizontal, overhanging said lower die shoe base (1) and supporting at the bottom a plurality of upper pressing stations (13), axially placed with said corresponding lower pressing stations (3) and carrying out the progressive conversion of said shells (2) in correspondent covers, said upper die shoe base being operated in vertical direction between a lifted position (A) of transferring said shells (2), in which said upper pressing stations (13) are distant from said lower pressing stations (3), and a lowered position (B) of converting said shells (2), in which said upper pressing stations (13) contact said lower pressing stations (3), with interposition of said shells (2);

- a continuous belt (6) for transferring said shells (2), with the upper branch (6a) of said continuous belt (6) overhanging said lower pressing stations (3) and designed to transfer said shells (2) through a plurality of said pressing stations (3) of said press (100);

a plurality of pushers (20), joined to said upper die shoe base (11), fit to interfere with said continuous belt (6), with said upper die shoe base (11) at lowered position (B), for setting said shells (2) at said correspondent lower pressing station (3);

said positioning device (30) characterized in that includes:

a fixed frame (31), assembled on said lower die shoe base (1), externally with regard to said lower pressing stations (3);

a set of plates (33), fixed substantially horizontal in the upper part of said frame (31), provided also with a plurality of housings (33a) in correspondence of said lower (3) and upper (13) pressing stations and a plurality of slots (33b) in correspondence of said pushers (20), said plates being designed to co-operate with said lower die shoe base (1), frame (31) and shells (2) for defining a vacuum box (34);

elastic striker means (35), joined to said lower die shoe base (1) in correspondence of said pushers (20), designed to support the upper branch (6a) of said continuous belt (6), and to slide vertically in phase relationship with the driving of said upper die shoe base (13), between a lifted position (C) and a lowered position (D), in which said shells (2) are stopped on said related lower pressing stations (3).

2. Device according to claim 1, characterized in that said elastic striker means (35) are constituted by a plurality of longitudinal bars (36), substantially horizontal and parallel, extending for at least part of said lower pressing stations (3) extension and associate at the bottom with correspondent elastic reaction members (37), embedded in said lower die shoe base (1).

3. Device according to claim 2, characterized in that said elastic reaction members (37) are constituted by axial action springs.

4. Device according to claim 2, characterized in that includes a plurality of splined blocks (38), placed at the top of said longitudinal bars (36) and designed to drive these last between said lifted (C) and lowered (D) positions.

5. Device according to claim 1, characterized in that said plates (33) comprise a first plate (43), a median plate (53), consecutive thereto, and a terminal plate (63), placed subsequently to said median plate (53) with regard to a feed direction (W) of said shells (2).

6. Device according to claim 5, characterized in that said median (53) and terminal (63) plates are spaced for allowing the crossing of a tab feeder belt (64).

Drawing