Stock feeding device of a press

Abstract

 The device for feeding stocks to a press (1) for can cover conversion, has drive means (20), constituted by a couple of slides (21,22) fixed longitudinally to the press (1) and slidingly supporting the feeding device (10) between an operative position (A) and an inoperative position (B) for accessing inside said press (1).
The feeding device (10) has also driving engaged members (30), constituted by a spline shaft (31), for ensuring its connection to main motion means (4) of the press (1), for the whole run between the operative positions (A) and inoperative (B).

Description

[0001] The present invention relates to the large number production of metallic cans by means of pressing.

[0002] Particularly the present invention concerns to a stock feeding device of a press for producing covers for such cans from substantially flat disks, this last processing also known as "conversion" of said covers.

[0003] It is known that, for carrying out steel or aluminium cans, used mainly for containing preserved foods or drinks, presses opportunely arranged for making the can components, and eventually for assembling more components, are used. Particularly, for producing opening tab covers, presses are normally used, fit to form the cover progressively from a circular shell, in correspondence of consecutive moulding dies, while the shell is carried step by step on a continuous conveyor belt. Such belts carry the shells on one or more parallel lines, consecutively in correspondence of related die lines where the shells are progressively converted. During the conversion process the press also applies a tab to the cover, fit to facilitate the can opening, in correspondence of a suitable die. Tabs are provided by a feeding device, arranged transversally to the shell conveyor belt and to the dies, disposing each tab at the exact position in correspondence of the related forming cover, with phase relationship with the operation of the other press components. Tabs are generally made by a known device, near the press, on a continuous belt of metallic sheet, and are carried immediately toward the feeding device. Alternatively the continuous belts with already preformed tabs are made elsewhere and supplied subsequently to feeding device. Tabs are arranged consecutively in the belt, and are eventually placed side by side on more lines, according to the press configuration. Once the tabs are applied, their working scraps, namely the belt residues, are triturated and carried elsewhere.

[0004] The US-A-4.723.882 describes a tab feeder device comprising a plate, which is bolted to the press frame. The crankshaft of the tab feeder is coupled to a gearing, which is connected to a driveshaft and a gear box providing a change of the motion direction. Such gear box is connected to a second crankshaft by a belt, which is driven by the main crankshaft of the press.

[0005] Also the US-A-4.568.230 describes a tab feeder in a press for converting covers of cans and the like. The feeder is mounted on the press bed and slide, so as the forces are distributed in substantially symmetrical manner over the opposed working areas of the bed and slide. It receives the intermittent rotary motion from the press power shaft, by means of a gear box and belts.

[0006] A rather common drawback of the known tab feeding devices consists in that, for own nature, tab belts have the tendency to get jammed in the transport and application mechanisms. In that case the presses must be stopped, the jammed tabs must be eliminated and the belt correctly replaced. For doing these operations the feeding device, which is arranged transversally to the cover feed axle, must be removed from the own working position, and therefore replaced at the end of the maintenance. This is a rather long and complex operation, since the belts, leading the motion to the feeder device members, must be detached, so losing their phase relationship, that must be restored and verified before restarting the press. This fact causes obviously serious decreases of press productivity, which is a particularly expensive apparatus, and therefore remarkable economic damages.

[0007] The EP-0.397.750 discloses a tab feeding device whose carrier is pivoted at a suitable hinge axle. The whole device, comprehensive of driving and tab feeding means, may be therefore pivoted to allow the access to press by an operator, without losing the phases.

[0008] The above described device shows however a fair realization complexity and is rather critical in setting.

[0009] The object of the present invention is to propose a tab feeding device of a press for producing can covers fit to be easily removed, allowing the access to the press, and therefore immediately replaced without losing working phases.

[0010] Further object of the present invention is to propose a motion of said feeding device having simple realization, low cost and high reliability.

[0011] The above mentioned objects are reached according to the claims.

[0012] The characteristics of the invention are underlined in the follow with particular reference to attached drawing tables, where:

• figure 1 shows schematically a side view of the device of the invention, joined to a relative press, at its working position;
• figure 2 shows a plan view of the same device, still at working position;
• figure 3 shows a view according to figure 1, with the feeding device in opening position;
• figure 4 shows the view of figure 2, with the feeding device still in opening position;
• figure 5 shows schematically a front view of the device.

[0013] Referring to figures 1 and 2, with 1 is indicated a press fit to working pieces 3, particularly circular shells, for getting correspondent converted covers, according to known manner, not described in detail.

[0014] The press 1 is provided with mean feeding members 2 of the pieces 3, constituted by an endless conveyor belt having consecutively housing lines, designed to housing said pieces 3 and transporting them progressively toward following known working stations. The main feeding members 2 are moved step by step by main motion means 4, constituted by a reduction unit connected to the press power members through a belt 4a.

[0015] Said work stations are supported by the base 7 of the press 1, substantially constituted by a bed 7a and by a bolster 7b, overhanging the bed 7a. Work stations include a die series forming the converted cover progressively from the circular shell. In correspondence of an intermediate work station, a stock constituted by a tab is applied to the cover 3. This tab is fed step by step by the feeding device 10 object of the invention, with a phase relationship with the driving of the main feeding members 2.

[0016] Such device is placed laterally to the press 1. It comprises substantially an input tab group 11, fixed on the horizontal plate 15a of an L-shaped frame 15 (see also figure 5) and designed to feed transversally the press 1 with a belt containing the preformed tabs; an output group 12, fixed to the same horizontal plate 15a; a plurality of drive belts 17, engaged with said input 11 and output 12 groups, and with first motion drive members 13, joined to the vertical plate 15b of said frame 15.

[0017] These latter are constituted by a motion return group of gear-wheel type, engaging slidingly and sideways driving engaged members 30. These are constituted by a spline shaft 31, horizontally placed in a position substantially parallel to said main feeding members 2 and supported by a couple of sphere bearings 32a,32b, fixed to the base 7 of the press 1.

[0018] The spline shaft is connected, at an end with the main motion means 4 previously mentioned.

[0019] The feeding device 10 has also drive means 20, slidingly supporting the feeding device, at a direction parallel to the mean feeding members 2, between an operative extreme position A (see figures 1 and 2) and an inoperative extreme position B (figures 3 and 4), at which said device is carried for allowing inside access to the press 1.

[0020] The drive means 20 are constituted by a couple of parallel slides, respectively upper 21 and lower 22, fixed longitudinally and laterally to the base 7 of the press 1.

[0021] The slides 21,22 slidingly engage correspondent splined sliders 16a,16b,16c, opportunely fixed to the vertical plate 15b of the frame 15.

[0022] The operation of feeding device 10, particularly concerning its motion for allowing inside access to the press 1, is quite intuitive.

[0023] With reference to figures 1 and 2, the frame 15 is in the operative extreme position A, that is the normal operation of the device 10. In such position the spline slider 16b is next to the end of upper slide 21, while the spline slider 16c is next to the end of the lower slide 22. The gear-wheel of the return group 14 engages the spline shaft 31 next to the end of this latter that is more distant from the main motion means 4.

[0024] As figures 3 and 4 show, the device 10, after having been carried in its inoperative extreme position B, has the gear-wheel of the return group 14 engaging the spline shaft 31 near to the end of this latter connected to the main motion means 4. It is evident that, with the device 10 in this latter position, the access to the inside parts of the press 1 is entirely free.

[0025] The above said description show that this particular coupling between the spline shaft 31 and the motion return group 14, in association with the coupling among the slides 21,22 and the corresponding spline sliders 16a,16b,16c, ensure the connection of the feeding device 10 to the main motion means 4 for the whole run of the device between the extreme operative position A and inoperative B.

[0026] An advantage of the invention consists firstly in having got an extremely simple motion of the feeding device 10, and therefore reliable and with lower production costs.

[0027] Besides, such a type of motion allows to free the press access independently by the dimensions of the device 10, since the excursion of this last depends exclusively on the dimensions of the slides 21,22 and of the spline shaft 31.

[0028] Finally, it is also evident that with the proposed type of motion there is not in every case any stress on the different motion transmission belts of the feeding device 10.

[0029] It is understood that all above described is by way of example not restrictive, therefore possible constructive alterations are included within the present technical solution, as above described and in the follow claimed.

Claims

1. Device for feeding stocks to a press (1), said press being provided with main feeding members (2) of working pieces (3), and main motion means (4), fit to drive said feeding members (2) for transporting said pieces (3) progressively in correspondence of following working stations of said press (1), and also to drive said feeding device (10), this latter being disposed for feeding said press (1) with said stocks in phase relationship with said main feeding members (2), said feeding device (10) characterized in that has drive means (20), fixed longitudinally to said press (1) and slidingly supporting said feeding device (10) between an operative position (A) and an inoperative position (B) for accessing inside said press (1), driving engaged members (30) being disposed in said feeding device (10) to ensure its connection to said main motion means (4) for the whole run between said operative position (A) and inoperative position (B).

2. Device according to claim 1, characterized in that said drive means (20) are constituted by a couple of parallel slides, upper (21) and lower (22), fixed laterally and longitudinally to the base (7) of said press (1) and engaging corresponding spline sliders (16,17) fixed to a frame (15) of said feeding device (10).

3. Device according to claims 1 and 2, characterized in that said driving engaged members (30) are constituted by a spline shaft (31), pivotally supported by a couple of bearings (32a,32b), having an end connected to said main motion means (4) and engaging first motion drive members (13), sliding together said feeding device (10).

4. Device according to claim 3, characterized in that said first motion drive members (13) have a motion return group (14), comprising a gear-wheel directly engaging with said spline shaft (31).

5. Device according to claim 2, characterized in that said frame (15) is constituted by an horizontal plate (15a), placed at the top, and a vertical plate (15b), placed at the bottom and substantially set against the wall of said press (1).

Drawing