Rivet feeding, turnover and front loading apparatus for riveting guns

Abstract: In a rivet feeding, turnover and front loading apparatus for riveting guns, there is a conveyor (2) for rivets (3) which have a pin (4) and a collar (5), the rivets (3) moving along the conveyor one behind the other suspended from the collar (5) with the pin (4) facing downwards. A rivet (3) turnover apparatus (9) at the outfeed end of the said conveyor (2) includes an obstacle element (34) which is positioned near to the conveyor (2) outfeed and acts on the rivets (3) that pass onto the conveyor in such a way that they make the rivets turn forward. The obstacle element consists of a fixed cylindrical bar (34) crossways with respect to the passing of the rivets (3) on the conveyor (2). The vibration type conveyor (2) is fitted with a track (6) which ends with an end part (6a) curved downwards.

Description: The present invention relates to a rivet feeding, turnover and front loading apparatus for riveting guns. Specifically, it is used for the automatic and continuous loading of pop rivets pre-assembled on a pin. In particular, the present invention refers to an apparatus of the type which includes: a rivet conveyor fitted with a pin and a collar, on which the rivets pass one behind the other suspended from the collar with the pin facing downwards; a rivet turnover apparatus at the outfeed of the conveyor; means for transporting the rivets from the said turnover apparatus to a front loading apparatus; a front loading apparatus which can load the rivets in a riveting gun. Several apparatuses of this type are already well-known. Patent EP N. 0285739, for example, discloses an apparatus in which the following occurs: the said means for transporting the rivets include a pneumatic feeding tube in which the rivets pass with the pin turned backwards with respect to the feeding direction; the turnover apparatus includes a rotating drum which moves between a first position in which it receives a rivet coming from the conveyor with the pin facing downwards inside a housing in the drum and a second position, when it has turned 180° with respect to the first position, in which the rivet in the said housing is upsidedown with the pin facing upwards and facing an inlet in the pneumatic feeding tube; the rivet is sucked into the tube using compressed air and is pushed towards the loading apparatus. It is also known, from document US 33667166, a riveting gun with a rivet feeding, turnover and loading apparatus. The apparatus comprises a vibratory bowl containing the rivets. The rivets slide on a straight-lined sloping raceway from the bowl to a funnel. Near the end of the raceway the pins of the rivets engage an obstacle element, this make the rivets turnover before they fall into the funnel. At this point the rivets are driven through a duct from the funnel to a rear portion of the gun. These well-known apparatuses, however, have some disadvantages. First, they are complex in construction, especially with respect to the turnover apparatus. Secondly, only a small number of rivets can be loaded on the riveting gun in a particular amount of time. Thirdly, they take up a lot of space, especially with respect to the front loading apparatus, which makes the apparatus difficult to handle and unsuitable for small areas. The object of this present invention is to overcome the said disadvantages of the prior art by providing an apparatus which is easily built and economical in construction and can load a high number of rivets in a particular amount of time. This object is achieved by the apparatus disclosed in claim 1. Further characteristics and advantages of the present invention are best described by the detailed description that follows of the preferred, but not exclusive, embodiment for the production of the same invention. These are illustrated in the accompanying drawings, which are purely by way of example are are not binding. They are as follows: Figure 1 is a schematic perspective view of the apparatus disclosed applied to a riveting gun; Figure 2 is a view from above of the rivet turnover apparatus; Figure 3 is a side view from below of Figure 2; Figure 4 is a side view of the rivet front loading apparatus; Figure 5 is a left side view of Figure 4 on an enlarged scale, with some parts cut away in order to better illustrate other parts; Figures 6 to 10 show the front loading apparatus in its operating configurations, with some parts cut away in order to better illustrate other parts. With reference to the above Figures, 1 refers to the entire rivet feeding, turnover and front loading apparatus for riveting guns. The apparatus 1 includes a vibration conveyor 2 for pop rivets 3 with a pin 4 and a collar 5. The conveyor 2, which is housed inside a closed and wheel-mounted base 8, is fitted with a track 6, on which the rivets 3 slide one behind the other, suspended from the collar 5 with the pin 4 facing downwards. On the conveyor 2 there is a stop element 7 which can move between two positions in which, respectively, it blocks and lets the rivets pass onto the track. The stop element 7 is used to make the rivets pass, one by one, using an external control. The apparatus 1 also includes a turnover apparatus 9 for rivets feeding out from the conveyor 2 and means 12, 14 for conveying the rivets to a front loading apparatus 10 which loads the rivets in a riveting gun 11 which has a shaft 15 and a handle 16. On the front part of the shaft, there is a head 31 and on the handle 16, there is a control pushbutton 30. The means for conveying the rivets include a compressed air tube 12, inside the base 8, fitted with an inlet 13 facing upwards. The tube 12 is connected to a pneumatic feeding tube 14, outside the base 8 which connects the tube 12 with the front loading apparatus 10. The feeding tube is enclosed in a tubular sheath 33. Inside the base 8, there are the means for generating compressed air which are well-known and not illustrated in the Figures. All the parts described up to now refer to the characteristics which are common to the well-known apparatuses and the present invention. According to the present invention, the turnover apparatus 9 includes an obstacle element 34 which is positioned near to the outfeed of the said conveyor 2 and which is designed to act upon the rivets 3 which pass onto the conveyor in such a way that it makes the rivets turn forward. The obstacle element 34, then, intercepts the rivets 3 which pass along the conveyor 2 and causes the rivets 3 to rotate around the element 34 itself. In effect, the obstacle element, in order to generate the rotation moment in the rivets 3 operates in conjunction with the force which feeds the rivets along the conveyor 2. The obstacle element consists of a fixed cylindrical bar 34 crossways with respect to the pins 4 of the rivets 3 which slide along the track 6. This track ends with an end part 6a curved downwards in the shape of a circular arc which is almost concentric to the bar 34. A hopper 35 is fitted below the conveyor 2 outfeed. It receives the over-turned rivets 3 and guides them towards the inlet 13. The bottom of the hopper 35 is immediately above this inlet 13. On command, a shutter 36 closes the tube 12 inlet 13. A doubleaction pneumatic cylinder 38 enables the shutter 36 which can move forwards and backwards in the direction of the arrow 39. Two side strips 37 are fitted on the end part 6a of the track and are parallel to it. The side strips 37 are parallel to each other and are positioned on opposite sides of a rivet which slides along the end part 6a of the track 6 and are therefore suitable for holding up the rivet during the turnover phase. The following is a description of the front loading apparatus 10. According to the present invention, this apparatus is assembled to the riveting gun 11 on the same axis as the gun itself. In other words, it is substantially co-planar to the shaft 15 and the handle 16 of the gun 11, as shown in Figure 5. The end part of the pneumatic feeding tube 14 is made of a rigid tubular body 17, fitted below and parallel to the shaft 15. The tubular body 17 ends with an outlet 18. It is envisaged that the rivets 3 are pushed towards the outlet 18 by the compressed air in the tube 14. A slider 19 slides along the outside of the tubular body 17 that functions, therefore, as the slider guide. A pneumatic cylinder 20 drives the slider 19. Two pairs of rods 21, parallel to each other, are joined to the slider on opposite sides. The rods 21 of each pair are arranged one above the other. A pick-up element 22 for the rivets (of a well-known type and only schematically illustrated in the Figures) is fitted to the ends of the rods 21. The pick-up element 22 forms the connecting rod for a four-link mechanism whose frame is the abovementioned slider 19. Each lower rod 21 has an extension 23 on which there is a pawl 24 which extends outwards laterally with respect to the slider 19. Each pawl 24 engages in grooves 25, 26, 27, 28 made in a fixed body 29. In particular, the grooves in each fixed body 29 are: two grooves 25 and 26 parallel to the sliding direction of the slider placed one 25 above the other 26; two oblique grooves 27 and 28, one at the front 27 and the other at the back 28, which allow the pawl 24 to pass from the upper groove 25 to the lower groove 26 and vice versa. The following is a description of the functioning of the apparatus 1, starting from the moment in which, by using the external control, the stop element enables a rivet 3 to pass onto the track 6. At this point, the inlet 13 shutter 36 is closed. As the pin 4 of the rivet 3 moves along the track, it meets the obstacle element 34. The action of the vibration conveyor 2 and the reaction of the obstacle element 34 combine in such a way to rotate the rivet 3 which makes it turn forward. Figure 3 shows some of the positions of the rivet 3 during the forward rotation. The curved end part 6a of the track 6 ensures that the rivet 3 follows the trajectory illustrated in the drawing. This trajectory favours and ensures the correct insertion of the rivets in the tube 12 inlet 13. When the rivet 3 is positioned with the head downwards and with the pin 4 turned upwards, the shutter 34 is opened; the rivet is then sucked inside the tube 12 and then inside the tube 14 and is conveyed to the loading apparatus 10. This loading apparatus is found in the configuration shown in Figure 6 in which the pick-up element 22 is directly facing the tubular body 17. Moreover, the slider 19 is behind the head 31 of the riveting gun 11 and the pawl 24 is in the upper groove 25. In this configuration, the rivet 3, pushed by the compressed air in the tube 14, goes into the pick-up element 22. Then the cylinder 20 makes the slider 19 and also, as part of the slider, the rods 21, the pawl 24, the pick-up element 22 and the rivet 3, pass in the direction of the arrow 32. Figures 7 and 8 show two successive phases of the continuous feeding of the cylinder 20. Figure 7 shows the cylinder 20 in an intermediate feeding phase in which the pawl 24 has reached the end of the upper groove 25 and is about to pass to the front oblique groove 27. Figure 8 shows the cylinder 20 having reached the end of its stroke; at this point the pawl 24 has moved to the lower groove 26, the rods 21 have turned upwards around the articulations on the slider 19 due to the movement of the pawl 24, the pick-up element 22 and the rivet 3 have been moved parallel to each other and are now found on the same axis as the head 31 of the riveting gun 11. Then the cylinder 20 moves back. Figures 9 and 10 show two consecutive phases in which the cylinder 20 moves back. Initially, the pawl 24 passes along the lower groove 26. Figure 9 shows one of the pawls 24-obviously, the same thing happens for the other pawl - while it is about to pass to the back oblique groove 28. In this configuration, the pin 4 of the rivet 3 is inserted in the head 31 of the gun 11. The head 31 is fitted with a flexible ratchet gear, which is well-known and not illustrated in the drawing, which secures the rivet pin 4 firmly. In Figure 10, the slider 19 moves back further, the pawl 24 passes to the upper groove 25, the rods 21 have lowered and, together with them, also the pick-up element 22 which, at this point, is without the rivet 3 and is now aligned with the tubular body 17. From this configuration, by making the slider 19 move back further, you can return to the configuration of Figure 6, with the gun 11 loaded and ready to fire the rivet and with the loading apparatus 10 ready to receive and load the next rivet 3. By pressing the pushbutton 30, the rivet loaded in the head 31 is fired and a new rivet is made pass onto the conveyor 2 by the stop element 7. The invention described can be subject to modifications and variations without thereby departing from the scope of the appended claims.

Claims: A rivet feeding, turnover and front loading apparatus for riveting guns of the type which includes: a rivet (3) conveyor (2) which has a pin (4) and a collar (5), on which the rivets (3) pass one behind the other suspended from the collar (5) with the pin (4) facing downwards; a turnover apparatus (9) for rivets (3) at the outfeed of the said conveyor (2); means (12, 14) for transporting the rivets (3) from the said turnover apparatus (9) to a front loading apparatus (10) ; A loading apparatus (10) for loading the rivets (3) in a riveting gun (11) said turnover apparatus (9) including an obstacle element (34) which operates near to the outfeed of the said conveyor (2) which is designed to intercept the rivets (3) which pass onto the conveyor (2) and to rotate, along with the said conveyor (2), the rivets around the said obstacle element (34) so as to rotate the said collar (5) with respect to the pin (4) until a configuration of substantial over-turning of the rivet (3) with respect to the forward configuration, characterised in that said loading apparatus is a front loading apparatus (10), and in that the said conveyor (2) is fitted with a substantially straight-lined track (6) on which the rivet (3) collars (5) slide and which ends with an end part (6a) curved downwards and the said obstacle element (34) operating near to the curve centre of the said curved end (6a) of the said track (6) and intercepts the pin (4) of the said rivets (3). The apparatus, according to claim 1, characterised in that the said curved end (6a) of the said turn-over apparatus has a pair of side strips (37) parallel to each other and set apart to allow the rivet (3) to pass, curved and spaced apart in the same way as the said curved end (6a) and designed to guide and support the rivet (3) during its turn-over. The apparatus, according to any of the previous claims, characterised in that the said obstacle element consists of a fixed cylindrical bar (34), positioned crossways with respect to the pin (4) of the rivets (3) which move along the conveyor (2). The apparatus, according to any of the previous claims, characterised in that it includes a hopper (35) positioned below the conveyer (2) outfeed and designed to collect the rivets (3) which have been turned over and to guide them towards the said transport means (12, 14). The apparatus, according to any of the previous claims, charactarised in that the said transport means include a tube (12) of compressed air which has an inlet (13) which is positioned below the conveyor (2) outfeed, and designed to collect the rivets (3) which have been turned over; there being envisaged a shutter (36), which, on command, closes the said tube (12) inlet (13). The apparatus, according to any of the previous claims, in which there is, in the said gun (11), a support shaft (15) for a co-axial head (31) for receiving the said rivets (3) and a handle (16), characterised in that the said front loading apparatus (10) is fitted to the riveting gun (11) substantially on the same plane as the said shaft (15) and the said handle (16). The apparatus, according to claim 6, characterised in that the said means for transporting the rivets include a pneumatic feeding tube (14) which leads to an outlet (18) on the same axis and on the same plane as the riveting gun (11); the said front loading apparatus (10) including a rivet pick-up element (22) which, on command, can be moved along the plane of the riveting gun (11) between a first position in which it is facing the said outlet (18) and a second position in which it is facing the head (31) of the riveting gun (11). The apparatus, according to claim 7, characterised in that the said front loading apparatus (10) includes two pairs of rods (21) fitted to the said pick-up element (22) and placed on opposite sides of the pick-up element, each pair consisting of parallel rods (21) arranged one above the other, one of which is fitted with an extension (23) which has a pawl (24) which engages laterally in the grooves (25, 26, 27, 28) in a fixed body (29), the two fixed bodies (29) being positioned on opposite sides of the axis of the riveting gun (11), each said pair of rods being fitted on opposite parts of a common slider (19) which, on command, can be moved on the same axis as the riveting gun (11). The apparatus, according to claim 8, characterised in that the end part of the said pneumatic feeding tube (14) includes a tubular body (17) on the external surface of which the said slider (19) slides.

Inventors: CARIATI VINCENZO, CARIATI, VINCENZO
Applicants: FAR SRL, FAR S.R.L.
Application year: 1996
Main classification: B21J15
IPC codes: B21J15