Step conveyor for conveying products between successive work stations

Abstract: A conveyor (1) for conveying products (2), particularly safety fasteners for sparkling drink bottle corks and stoppers, and presenting a fixed supporting structure (11); a number of housing elements (17) for housing the products (2) and movable along a given path (P); and conveying means (8) for moving the housing elements (17) in steps along the path (P); the conveyor (1) also presenting axial retaining members (71, 72) for axially retaining the products (2), and which are fixed to the supporting structure (11), extend along the path (P), and cooperate in sliding manner with a flange portion (5, 23) of the products.

Description: The present invention relates to a step conveyor for conveying products, particularly safety fasteners for sparkling drink bottle corks and stoppers, between successive work stations. In the following description, reference is made, for the sake of simplicity, to the above application purely by way of example. As is known, safety fasteners of the aforementioned type normally comprise a body and a lower girdle, each formed from a single piece of shaped wire. The body comprises an upper annular element for supporting a metal cap, which cooperates with the top surface of the cork or stopper; and four equally spaced, slightly diverging uprights extending from the annular element, and presenting respective eyelets at the end through which the annular girdle is fitted to tighten the fastener about the neck of the bottle. Such fasteners are formed on automatic machines comprising a number of work stations through which the semifinished products are fed in steps. More specifically, a first work station forms the body; and the bodies are fed along a bar to a normally indexing-table type conveyor by which they are fed through further work stations, e.g. for inserting the girdle, shaping the eyelets, and inserting the cap. Known conveyors present elements for housing the products (bodies and finished fasteners), and devices for retaining the products inside the housing elements during transfer from one work station to another, see for example WO-A-8911360. On known conveyors, the housing elements present respective retaining devices, which are relatively complex and therefore expensive as a whole. Moreover, the retaining devices normally provide for snap-on retention of the products, which means a high degree of precision is required to ensure not only safe, reliable clamping of the product, but also troublefree release at the unloading station. Which precision and reliability are obviously impaired in course of time due to wear. It is an object of the present invention to provide a product conveyor designed to overcome the drawbacks typically associated with known devices of the aforementioned type. According to the present invention, there is provided a conveyor for conveying products presenting an axis and a flange portion projecting substantially radially in relation to said axis, in particular safety fasteners for sparkling drink bottle corks and stoppers; said conveyor comprising a fixed supporting structure; a number of housing means for housing said products and movable along a given path; and conveying means for moving said housing means in steps along said path; said products being housed inside said housing means with said axis substantially perpendicular to said path; characterized by comprising axial retaining means for axially retaining said products, and which are fixed to said supporting structure and extend along said path; said axial retaining means cooperating in sliding manner with said flange portion of said products. A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a top plan view of a conveyor in accordance with the teachings of the present invention; Figure 2 shows a section along line II-II in Figure 1; Figure 3 shows a section along line III-III in Figure 1; Figure 4 shows a detail of the Figure 1 conveyor; Figure 5 shows a section along line II-II in Figure 1; Figure 6 shows a section along line III-III in Figure 1; Figure 7 shows a larger-scale detail of Figure 3; Figure 8 shows a safety fastener conveyable by the conveyor according to the invention. Number 1 in Figures 1, 2 and 3 indicates a step conveyor for conveying wire products 2, in particular safety fasteners for sparkling drink bottle corks and stoppers and relative semifinished products. Conveyor 1 forms part of an automatic machine for manufacturing safety fasteners, of which only the parts pertinent to the present invention are shown, and which comprises a number of work stations (not shown) through which products 2 are fed in steps by conveyor 1. For the sake of simplicity, in the following description, the term "product" is used to indicate both a semifinished product and a finished fastener, depending on the work stage referred to, the exact nature of the product only been specified when strictly necessary. By way of reference, Figure 8 shows a product 2 comprising a finished safety fastener, in turn comprising a body 3 and a girdle 4, each formed from a single piece of wire. Body 3 comprises an annular element 5, and four uprights 6 projecting from annular element 5 and presenting respective eyelets 7 at the end; uprights 6 are equally spaced angularly and diverge so that body 3 is substantially truncated-cone-shaped with an axis X; girdle 4 is annular and fitted in sliding manner through eyelets 7; and fastener 2 also comprises a metal cap 23 inserted between uprights 6 and contacting annular element 5. With reference to Figures 1, 2 and 3, conveyor 1 comprises a circular table 8 mounted for rotation, by means of bearings 9, about an axis A and inside a sleeve 10 fixed to the structure 11 of the machine. Table 8 comprises a disk 12 of axis A; a central hub 13 extending axially downwards for fitment on to bearings 9; and a peripheral flange 14 extending axially upwards and presenting a substantially regular prismatic outer surface defining a number (e.g. twenty-four) of flat faces 15 at which are formed respective angularly equally spaced through seats 16. On flange 14 of table 8, conveyor 1 also comprises a number of elements 17 for supporting and housing fasteners 2, and each fitted inside a respective seat 16. One element 17 is shown in detail in Figures 4 to 6, and substantially comprises a tubular body 18 of axis B, which, in use, is positioned radially in relation to table 8; and a flat end flange 19 for fitment to a respective face 15 of table 8. Body 18 presents four angularly equally spaced inner grooves 20 in turn presenting respective inclined bottom surfaces 21 converging towards axis B from flange 19 towards the opposite end of body 18; and grooves 20 extend along perpendicular planes P1, P2 through axis B and inclined at 45° to a horizontal plane through axis B. Elements 17 are fitted to table 8 so that body 18 of each element is housed inside a respective seat 16, and flange 19 rests against respective face 15 to which it is fixed by means of screws 25. The periphery of disk 12 of table 8 is fitted with a number of equally spaced drive pins 26, equal in number to elements 17, and which extend downwards from disk 12 and cooperate with a known drive device (not shown) for rotating table 8 in successive steps equal to the angular spacing between elements 17. Conveyor 1 provides for conveying products 2 from a loading station 29 to an unloading station 30 along a circular path P and with axis X of products 2 maintained perpendicular to path P. Since path P extends about an angle of 270°, the axes B of the elements 17 located respectively at loading station 29 and unloading station 30 are perpendicular to each other. Loading station 29 presents a device 31 for supplying products 2, which in this case only comprise bodies 3 of the fasteners. Device 31 comprises a bar 32 along which products 2 are fed successively in steps in known manner with axis X coincident with axis C of bar 32; axis C of bar 32 is coincident with axis B of the element 17 located at loading station 29; bar 32 is connected to the main transmission of the machine (not shown) so as to move linearly back and forth along axis C; products 2 are so oriented on bar 32 that uprights 6 lie in planes through axis C and inclined 45° to the horizontal; and bar 32 presents a rounded end 33 with a central vertical through slot 34. Conveyor 1 also comprises a loading/unloading device 35, which is fitted to a fixed supporting plate 36a extending over disk 12 of table 8 and rigidly connected to the top end of sleeve 10. Device 35 substantially comprises a gripper 36 for axially clamping products 2 at loading station 29; an extractor 42 for expelling products 2 (in this case, finished fasteners) at unloading station 30; and an actuating mechanism 43 for activating gripper 36 and extractor 42. More specifically (Figure 2), gripper 36 comprises two elongated superimposed levers 38 extending radially in relation to table 8 at loading station 29, and hinged at an intermediate portion to a bracket 39 fitted to plate 36a, so as to rotate about respective horizontal axes. At the end facing outwards of table 8, levers 38 present respective teeth 40 facing each other and adjacent to the element 17 located at loading station 29; at the opposite end, levers 38 present respective cam portions 44 projecting crosswise to levers 38; and portions 44 present respective facing surfaces 44' forming a ramp crosswise to levers 38, and presenting different clearances at each end, more specifically a smaller clearance at the free end of portions 44. Actuating mechanism 43 comprises a drive shaft 45 of axis A, internally coaxial with sleeve 10, and presenting an end pinion 46 projecting beyond plate 36a and which is rotated back and forth in known manner (not shown) by the main transmission of the machine (not shown). Mechanism 43 also comprises a rack rod 47 extending perpendicularly to gripper 36, sliding longitudinally inside a guide 48 integral with plate 36, and presenting a toothed end portion 49 meshing with pinion 46. Rod 47 is fitted laterally with a projecting pin 50 in turn fitted on the end with a roller 54 interposed between surfaces 44' of portions 44 of levers 38; and portions 44 are held contacting roller 54 by traction springs 52 connecting levers 38 to each other. The opposite end of rod 47 is connected rigidly to extractor 42, which presents a concave end surface 55 cooperating with products 2 (finished fasteners) at unloading station 30. Conveyor 1 also comprises a contrasting device 60 associated with a station 61 for inserting cap 23 and located diametrically opposite loading station 29. Contrasting device 60 substantially comprises a slide 62 travelling radially to and from station 61, and presenting, at one end, a head 63 cooperating with product 2, and, at the opposite end, a vertical-axis actuating roller 64. Slide 62 travels through a guide 65 fitted to supporting plate 36a, and is fitted rigidly integral with a transverse plate 66 close to roller 64. Plate 66 faces guide 65, and compression springs 67 are interposed between plate 66 and guide 65 to keep slide 62 in a withdrawn position in which head 63 is clear of the path of products 2. Device 60 also comprises a cam 70 fitted integral with pinion 46 and cooperating with roller 64 of slide 62 to move slide 62 outwards of the table so that head 63 cooperates with the product 2 located at station 61. Conveyor 1 also comprises a pair of axial retaining members 71, 72 for axially retaining products 2 inside moving elements 17. More specifically, each member 71, 72 comprises a supporting structure 73 fitted to plate 36a; and a pair of curved rails 74 extending along portions of the path of products 2. The rails 74 of each member 71, 72 are superimposed and spaced vertically, and extend along and on the inner side of flange 14 of table 8. The distance between rails 74 of member 71 and flange 14 is so selected that annular element 5 of products 2 carried by elements 17 is flush with the inner side of rails 74 (Figure 7); the vertical distance between rails 74 is such as to enable products 2 to slide between the rails, but is less than the maximum diameter of annular element 5; and annular element 5 therefore defines a flange portion of products 2, projecting substantially radially in relation to axis X, and cooperating at two diametrically opposite portions with rails 74 to prevent products 2 from being withdrawn axially from elements 17. Similarly, the distance between rails 74 of member 72 and flange 14 is so selected that the cap 23 of products 2 carried by elements 17 is flush with the inner side of rails 74 (Figure 7); and the vertical distance between rails 74 is such as to enable products 2 to slide between the rails, but is less than the maximum diameter of cap 23, which in this case constitutes the flange portion of products 2 cooperating with rails 74. Leaving the stations clear, rails 74 of member 71 extend between loading station 29 and cap insertion station 61, and rails 74 of member 72 between station 61 and unloading station 30. Conveyor 1 operates as follows. At each step of the conveyor, bar 32 loads a product 2 (at this point, only a body 3) into the element 17 located at loading station 29. Inside element 17, product 2 is housed with axis X coincident with axis B, with annular element 5 projecting axially from body 18 of element 17 towards axis A (Figure 1), and with uprights 6 engaged inside respective grooves 20, so that product 2 is locked angularly, and is locked axially in one direction by girdle 4 resting against body 18 of element 17. Loading/unloading device 35 is controlled by the main transmission of the machine in time with bar 32, so that, when bar 32 is in the forward position described above, shaft 45 rotates (anticlockwise in Figure 1) and rod 47 is moved (downwards in Figure 1) by pinion 46 into a position in which roller 54 cooperates with the minimum-clearance portions of surfaces 44' (position shown by the dotted line in Figure 1) thus closing gripper 36. Teeth 40 of levers 38 of gripper 36 engage bar 32 at slot 34 and behind respective diametrically-opposed portions of annular element 5 of product 2 to prevent the product from withdrawing together with bar 32. Simultaneously with the above rotation of shaft 45, extractor 42 is moved towards and expels the product 2 (finished fastener) at unloading station 30, and cam 70 is rotated into a position contacting roller 64 of slide 62. Cam 70 pushes slide 62 into the forward position (Figure 2) in which head 63 cooperates with product 2 (in this case, body 3) to withstand the pressure produced by a male member (not shown) for inserting cap 23. At this point, shaft 45 is restored to its former position (Figure 1) so that gripper 36 opens, extractor 42 is withdrawn, and slide 62 is withdrawn by springs 67. Upon table 8 being rotated one step forward, the products 2 located respectively at loading station 29 and station 61 are so moved as to cooperate respectively with axial retaining members 71 and 72. More specifically, and as shown in Figure 3 and in more detail in Figure 7, annular element 5 of the products 2 cooperating with member 71, i.e. located along the path portion between (but excluding) stations 29 and 61, is located axially contacting rails 74, which thus define respective supporting elements for preventing the products from being spun out of respective elements 17 as table 8 is rotated. Similarly (Figure 3), member 72 axially retains the products 2 (finished fasteners) located along the path portion between (but excluding) stations 61 and 30, to prevent them from withdrawing from respective elements 17. In this case, however, as opposed to annular element 5, rails 74 of member 72 and products 2 contact at diametrically-opposed portions of cap 23. The above operation of conveyor 1 is repeated cyclically, and, at each step (rotation) of table 8, products 2 cooperate in sliding manner with respective axial retaining members 71, 72. The advantages of conveyor 1 according to the present invention will be clear from the foregoing description. In particular, members 71 and 72 for axially retaining products 2 along path P provide, in an extremely straightforward, effective manner, for preventing withdrawal of the products from table 8, with no need for complex, high-cost retaining elements designed to travel with the table. Moreover, by virtue of products 2 simply resting as opposed to being snapped on to members 71 and 72, engagement and release of the products by members 71 and 72 involve no stress or particular mechanisms, and are both straightforward and reliable. Clearly, changes may be made to conveyor 1 as described and illustrated herein without, however, departing from the scope of the present invention. In particular, as opposed to being an indexing-table type, conveyor 1 may, for example, define a straight transportation path.

Claims: A conveyor (1) for conveying products (2) presenting an axis (X) and a flange portion (5, 23) projecting substantially radially in relation to said axis (X), in particular safety fasteners for sparkling drink bottle corks and stoppers; said conveyor (1) comprising a fixed supporting structure (11); a number of housing means (17) for housing said products and movable along a given path (P); and conveying means for moving said housing means (17) in steps along said path (P); said products being housed inside said housing means (17) with said axis (X) substantially perpendicular to said path (P); characterized by comprising axial retaining means (71, 72) for axially retaining said products (2), and which are fixed to said supporting structure (11) and extend along said path (P); said axial retaining means (71, 72) cooperating in sliding manner with said flange portion (5, 23) of said products (2). A conveyor as claimed in Claim 1, characterized in that said housing means (17) comprise first one-way axial supporting means (18) for said products (2); said axial retaining means (71, 72) comprising second axial supporting means (74) acting on said flange portion (5, 23) of said products (2) in the opposite direction to said first axial supporting means (18). A conveyor as claimed in Claim 1 or 2, characterized in that said second axial supporting means comprise at least a pair of rails (74) equally spaced along said path (P) and cooperating with diametrically-opposed portions of said flange portion (5, 23). A conveyor as claimed in any one of the foregoing Claims, characterized in that said second axial supporting means (74) extend along a number of separate portions of said path (P) extending between stations (29, 61, 30) for axially moving said products (2). A conveyor as claimed in Claim 4, characterized in that one of said stations for axially moving said products (2) is a loading station (29) for loading said products (2) on to said conveyor (1). A conveyor as claimed in Claim 5, characterized by comprising temporary axial retaining means (36) for temporarily retaining said products (2) axially at said loading station (29). A conveyor as claimed in Claim 6, characterized in that said temporary axial retaining means comprise a gripper (36) cooperating with said flange portion (5) of said products; and actuating means (35) for activating said gripper (36) in time with said conveying means (8). A conveyor as claimed in any one of the foregoing Claims, characterized in that one of said stations for axially moving said products is an unloading station (30) for unloading said products (2) off said conveyor (1). A conveyor as claimed in Claim 8, characterized by comprising extracting means (42) cooperating axially with said products (2) at said unloading station (30); and actuating means (35) for activating said extracting means (42) in time with said conveying means (8). A conveyor as claimed in Claim 9, when dependent on Claim 7, characterized in that said actuating means (35) for activating said gripper (36) and said extracting means (42) comprise a common control mechanism (43). A conveyor as claimed in one of the foregoing Claims, characterized in that said conveying means comprise an indexing table (8) fitted with said housing means (17); said path (P) being circular. A conveyor, as claimed in any one of the foregoing Claims, for conveying safety fasteners for sparkling drink bottle corks and stoppers, characterized in that said flange portion is defined by an annular element (5) of the body (3) of said fasteners (2). A conveyor, as claimed in any one of the foregoing Claims, for conveying safety fasteners for sparkling drink bottle corks and stoppers, characterized in that said flange portion is defined by a cap (23) of said fasteners ( 2).

Inventors: GETTO PIERO, GETTO, PIERO
Applicants: GEFIN SRL, GEFIN S.R.L.
Application year: 1996
Main classification: B67B5
IPC codes: B67B5, B21F45