PUNCHING AND NIBBLING MACHINE HAVING DIE-CARRYING TURRETS WITH HORIZONTAL AND PARALLEL AXES

Abstract: The invention relates to a punching and nibbling machine of the kind comprising a C-shaped framing (10) on which a couple of die-carrying turrets (11,12) is mounted, the workpiece (33) being driven between said turrets. The turrets are mounted on the same vertical plane and on parallel axes (13,14).

Description: PUNCHING AND NIBBLING MACHINE HAVING DIE-CARRYING TURRETS WITH HORIZONTAL AND PARALLEL AXES Punching and nibbling machines are known, in which the moulds (punches and dies) are mounted on a couple of superimposed turrets which are driven to stepwise rotation about the same vertical axis. The workpiece is driven between the two turrets by a so-called coordination system, which is equipped with plungers that follow a sample template. The machines referred to above have, as a rule, a supporting frame in the shape of a "C", in the interior of which the die-carrying turrets are housed,whereas the coordination system is outside said frame and is arranged either laterally or frontally with respect to the machine structure. So is done to reduce the dimensions of the frame, which is exposed to considerable bending stresses. However, to arrange the coordination system either frontally or laterally of the die-carrying turrets is a source of not negli#gible troubles. If the coordination system is mounted laterally, it is not possible, on account of the bulk of the system, to machine a continuous tape which must be repositioned every time relative to the die-carrying turrets. Conversely, if the coordination system is mounted frontally, still for reasons of bulk, it is impossible to machine a workpiece having a double width by tipping it up. In addition, the visibility in the processing area is extremely reduced. Lastly, both in the former and in the latter case, it is required that an additional structure is provided on the machine side, or on the machine front, which is capable of bearing the coordination system. Another shortcoming which is common to the punching and nibbling machines having its turrets superimposed on parallel horizontal planes, is due to the bulk of the turrets on the working plane. This bulk makes it difficult to round and to cut off corners on pieces having reduced sizes, that is whenever the edge of the workpiece must overtake the mold. At any rate, to machine small-size workpieces, it is necessary that the system of coordination be equipped with very slender pincers, which are thus weak, so as to enable them to enter between the die-carrying turrets. Moreover, the visibility of the workpiece is still uneasy. In order to remove these drawbacks, it has already been suggested to provide machines in which the coordination system is housed in the interior of a C-shaped framing, at the outside of which, conversely, the molds have beeen installed, which are no longer mounted on turrets, but are, instead, stored in a magazine and fed individually into the working area by means of a swinging arm. In a machine of the latter kind, the coordination system is thus located at the rear of the mold, relative to the machine structure. Such an arrangejnent of parts is an advantage because it permits, longitudinally, to reposition as many times as desired (in the case of a tape) the workpiece, and, transversally, to machine a piece having a double width by tipping the workpiece up. However, the machine of this latter class do not afford fully satisfactory performances insofar as the system for feeding the molds to the machining area is concerned. An object of the present invention is, thus to provide a punching and nibbling machine which does not exhibit the defects of the conventional machines, while retaining the appreciable qualities thereof. Having this object in view, according to the invention, it has been envisaged to provide a punching and nibbling machine of the kind comprising a C-shaped frame on which a die-carrying turret couple is mounted, between which the workpiece is fed, said machine being characterized in that said turrets are mounted on the same vertical plane and on parallel axes. Preferably, such turrets are of an annular shape and their interior contains the linkages for actuating the molds. By so doing, a machine is obtained which is extremely compact and in which the coordination system can be arranged past the molds, and thus it is contained in the interior of the C-shaped frame and can afford all the advantages which have been outlined above. To have the turrets contained in the C-structure along a vertical plane, is a circumstance which also enables to design a twin-C system for separately sustaining the turret unit and the linkage unit, to ensure the satisfactory alignment of the punches with the dies. Such a structure can be embodied in a self-containedarrangement, as will be explained hereinafter. In addition, to have arranged the turrets on the same vertical plane is such that only a limited space of the machining plane is occupied, so that machining of small-size workpieces can be accomplished with a mini, mum swarf production and a very good visibility of the machining field. The structural and functional features of the invention and its advantages over the prior art will become still clearer from a survey if the detailed ensuing description, aided by the accompanying drawings, wherein FIGURE 1 is a side elevational view of a machine constructed according to the principles of this invention, FIGURE 2 is a closing view of the mold-carrying turrets, FIGURE 3 is a cross-sectional view, taken along the line Ill-Ill of FIGURE 2, and FIGURE 4 is a cross-sectional- view taken along the line IV-IN/ of FIGURE 2. Having now reference to the drawings, the machine in question is structurally composed of a framing 10, of the known C-shaped outline, on which a couple of moldcarrying turrets, 11, 12, is mounted. Such C-frame can be mounted as inserted into an external C-structure, 9, connected to the frame 10 through specially provided bushings 8. Frame 9 carries, frontally, the linkage units 2223 which are secured thereto by screws 7. According to the present invention, the turrets 11, 12, are arranged on the same vertical plane and can be rotated about their respective parallel axes, 13, 14. The turrets, 11, 12,, have an annular outline and are mounted between two confronting shoulders, 15, which make up the framing 10 aforementioned. Each turret is borne for rotation by a set of bearings, 16, which are extended from the shoulders 15 and engage respective edge races 17, the latter being formed through the turret structure. The upper turret, 11, carries the punches, 18, whereas the lower turret, 12, carries the dies, 19. Punches 18 and dies 19 are radially mounted in their respective turrets of annular shape, 11 and 12, and are housed within bores 20 and each of them is latched in position by a couple of diametrically opposed dowels, 21, whereas the turrets are positioned by dowels, 51, driven by actuators, 50, which are placed in correspondence with the horizontal axis of the mold. According to still another feature of the invention, in the interior of the turrets, 11, 12, boxes such as 22, 23 are received, which contain the control linkages for driving the punches and the dies and that are secured also to the outer structure 9. Such linkages, as well as the punches and the dies, are not shown in detail herein since they can be of any known make with which all those skilled in the art are familiar. The simultaneous stepwise rotation of the turrets 11 and 12 is controlled by a prime mover unit (not shown) via a chain drive, gears and gear trains. More detailedly, the drive is transferred by two mutually meshing gears 24 and 25, via chains 26 and pinions 27, to two gears, 28 and 29 which are in mesh with the respective rings gears 30, 31, which are formed on the external peripheral surface of the turrets, 11, 12. By such an arrangement of the turrets 11, 12 and the boxes 22, 23, it becomes possible to conveniently locate, in the zone 32 of the frame 10 and past the turrets themselves, a coordination system intended to shift the workpiece 33, said system having not been shown in detail herein for the sake of simplicity, inasmuch as it can be of any known make.

Claims: CLAIMS 1. A punching and nibbling machine of the kind com prising a C-shaped frame whereon a couple of die-carry ing turrets is mounted, between which the workpiece is moved, characterized in that said turrets are mounted s on the same vertical plane and on parallel axes. 2, Machine according to Claim 1, characterized in that said turrets have an annular shape and their inte rior contains linkages for actuating the molds. 3. Machine according to Claim 2, characterized in that said annular turrets are borne between two confron ting shoulders of the C-frame by sets of bearings extend ed from said shoulders and positioned with the frame, by means of dowels and actuators, into bores placed on the two sides of the annulus of each turret and perpendi cular to each positioning seat for punches and dies. 4. Machine according to Claims 1, 2 and 3, wherein the C-structure carrying the mold-carrying turrets can be mounted within another C-structure external thereto and carrying said linkages. 5. Machine according to Claim 2, characterized in that in said annular turrets bores are drilled wherein said molds are radially mounted. 6. Machine according to Claim 4, characterized in that said molds are latched in position within said bo res by diametrically opposed dowels.

Inventors: PAVONE, TOMMASO
Applicants: PAVONE, TOMMASO
Application year: 1981
Main classification: B21D28
IPC codes: B21D28, B23D27