SYSTEM FOR FIXING ROTARY CUTTING DIES IN MACHINES FOR DIE CUTTING LAMINAR MATERIAL

Abstract: System for fixing rotary die cutters in die cutting machines for cutting laminar material, said system comprising fixing means between the die (1) and a die-holder surface or cylinder (2) around which the die (1) is arranged, wherein the fixing means include a plurality of bolts (3) actuated by an actuator (5) housed inside a hollow body (8) fixed to the die-holder cylinder (2) in order to provide for a rapid fixing of the rotary die to the die-holder cylinder.

Description: OBJECT OF THE INVENTION The present specification refers to a system for fixing rotating dies on die cutting machines of laminar material, whose object lies on being configured as a system permitting fixing the rotating dies on the die holder cylinders or surfaces on die cutting machines of laminar material. FIELD OF THE INVENTION This invention, which is defined in claim 1, has its application within the industry dedicated to manufacturing die cutting machines, especially die cutting machines of laminar material. BACKGROUND OF THE INVENTION In rotating die machines, the material to be cut, for example cardboard for manufacturing boxes, passes between a die holder cylinder and a counter-die cylinder or an anvil-die which also rotates, so that the die acts upon the counter-die and cuts or deforms the cardboard each time the cylinders turn. To prevent the die from being damaged by the blow, the counter-die surface is provided with a polyurethane coating. Currently, rotating dies are fixed on the die holder cylinder by means of screws coupled to the corresponding threaded holes in the surface of the die holder cylinder. This fixing system has the main drawback of being excessively slow since there are a considerable number of screws to be placed. That affirmed in the previous paragraph implies that the time the machine is stopped each time the new die should be assembled is excessive, which affects the productivity of the rotating die machine. DESCRIPTION OF THE INVENTION The system for fixing the rotating dies on die cutting machines of laminar materials proposed by the invention is configured as being able to resolve said drawback, having other advantages as well that will be disclosed next. The system for fixing the rotating dies on die cutting machines of laminar material object of the invention comprises fixing means between the die and the die holder cylinder, the fixing means having a plurality of bolts actuated by an actuating device. This feature permits rapidly fixing the rotating die to the die holder cylinder, so that it is possible to achieve that the time the machine is stopped to change the die is less than it currently is, thus improving the die cutting machine's productivity. The system of the invention also has the particularity that each one of the actuating devices is housed inside a hollow body fixed to the die holder cylinder. Patent of Invention GB-A-8611 69, when which the preamble of claim 1 is based, discloses a SYSTEM FOR FIXING A ROTATING CUTTING DIE ON MACHINES FOR CUTTING WITH DIE OF LAMINAR MATERIAL, including a fixing means for the cutting die and a cutting die support cylinder or surface around which the cutting die is arranged, the type of cutting die used is not described in that invention, however it discusses an application of the invention in which a cutting die can be arranged around the cylinder. In that invention, the housing for the actuating device on a hollow body fixed to the cylinder is not described, nor does it describe the existence of bolts fixing the die to the die holder cylinder in the area of largest diameter, nor the features of the actuating devices and additional elements. As a result of this feature, the costs of manufacturing the die cutting machine are not excessively high, thus also allowing an easy and flexible maintenance and machining. The actuating devices are also preferably fluid dynamic cylinders independently acting in the two halves of the die holder cylinder. According to its embodiment, the fluid dynamic cylinders are pneumatic or hydraulic cylinders, and the actuating devices are also preferably fluid dynamic cylinders independently acting in the two halves of the die holder cylinder. Also according to its embodiment, the fluid dynamic cylinders are pneumatic or hydraulic cylinders. It should be noted that also preferably, the bolts are quincuncially placed on the rotating die, so that it is possible to achieve that the bolts uniformly occupy the entire surface of the die. According to an embodiment, the system of the invention also comprises threaded drills to fix the rotating die to the die holder cylinder, these threaded drills being placed in order to secure the fixing of the rotating die to the die holder cylinder in case of not using the system object of the invention. Preferably, the drills are also quincuncially placed on the die holder cylinder, occupying the locations not used by the bolts. DESCRIPTION OF THE DRAWINGS To complement the description being carried out and with the object of helping to better understand the features of the invention, a set of plans accompany the present specification as an integral part thereof, with an illustrative and non-limiting character, showing the following: Figure 1 shows an elevational cross-sectionial view of an actuating device. Figure 2 shows a perspective view of a die placed on a die holder cylinder. Figure 3 shows a detailed view of the system of centering the die on the die holder cylinder. Figure 4 shows a fixing hole of the die. Figures 5, 6, 7 and 8 show elevational cross-sectional views of the four working positions of the actuating device in relation to the system for fixing rotating dies on die cutting machines of laminar material object of the invention. PREFERRED EMBODIMENT OF THE INVENTION In view of these drawings, it is possible to see how the system for fixing rotating dies on die cutting machines of laminar material is constituted as from rotating dies (1) fixed to die holder cylinders (2), comprising a plurality of bolts (3) actuated by a pneumatic cylinder (5). The bolts (3) are fixed to the piston (6) of the pneumatic cylinder (5) with a lock nut (4), and at its head (7), they comprise an area of larger diameter fixing the die (1) to the die holder cylinder (2). The pneumatic cylinders (5) are housed inside the respective hollow bodies (8), and each one of these hollow bodies (8) is fixed to the die holder cylinder (2) by means of four lock screws (10). As can be seen in figure 2, the bolts (3) are quincuncially placed on the die holder cylinders (2) and on the rotating die (1), so that they uniformly occupy the entire surface of the die (1). Figure number 3 shows that in order to facilitate centering the die (1) on the die holder cylinder (2), the latter has a circumferential butt (19) and an axial butt (20) to center the die (1), while the die (1) has a centering reglet (21). The fixing system can also comprise threaded drills (22) to fix the rotating die (1) to the die holder cylinder (2), and in this case, the threaded drills (22) are also quincuncially placed on the die holder cylinder (2) and on the rotating die (1), occupying the locations not previously occupied by the bolts (3). On the bottom of each pneumatic cylinder (5) an orifice (11) is made connected to a conduit (12) for injecting compressed air, and in the case that the bolt (3) does not find any outlet hole (15) in the die (1), the system of the invention has a hollow piston (6) with a spring (14) inside that gives way and allows the bolt (3) to remain hidden inside the piston (6), and in a recess (18) that the cover (9) of the pneumatic cylinder has, said cover (9) being fixed to the die (1) with the same screws (10) as the hollow body (8). The holes (15) of the die (1) are provided with a swivel (16) provided with a recess (17) with the shape of the bolt's (3) head (7). In figure number 5, the different working phases of the actuating devices can be seen. The previously mentioned phases of the actuating devices are the following, namely: Phase one.- The pneumatic cylinder (figure number 5) has no air pressure, so that the spring (13) pushes the bolt (3) towards the inside of the hollow body (8). The die (1) is placed on the die holder cylinder (2), butting the circumferential butt (19) and the centering axial butt (20) of the die holder cylinder (2). Phase two.- As shown in figures 6 and 7, the pneumatic cylinder receives the compressed air through an orifice (11) carried out on the bottom of the pneumatic cylinder (5), connected to a conduit (12), upwardly pushing this compressed air to the piston (6) and also the bolt (3), thus overcoming the stress of the spring (13) as shown in figure number 7. In case that the bolt (3) outlet were obstructed, the compressed air would continue to overcome the stress of the spring (13), thus keeping the piston up, but the bolt (3) would remain housed inside the piston (6) exerting a small pressure produced by the spring (14) on the die (1), as shown in figure number 6. Phase 3.- In this phase, the die (1) has to axially shift towards the position of the swivel (16), for then immediately removing the compressed air from inside the pneumatic cylinder, thus obtaining the spring's (13) action and thus shifting the piston (6) and the bolt (3) towards the inside of the die holder cylinder (2), thus fixing the bolt's (3) head (7) and the die (1) to the die holder cylinder (2), as shown in figure number 8.

Claims: A system for fixing rotating dies on die cutting machines of laminar material, comprising fixing means of the die (1) and a die holder cylinder or surface (2), around which the die (1) is arranged, the fixing means having a plurality of bolts (3) actuated by an actuating device (5) housed inside a hollow body (8) fixed to the die holder cylinder or surface (2), characterized in that the bolts (3) comprise an area of larger diameter (7) on their head fixing the die (1) to the die holder cylinder or surface (2), incorporating actuating devices (5) configured as fluid dynamic cylinders (5) in the case of a die holding cylinder (2), the fluid dynamic cylinders (5) acting independently in the two 180° halves of the die holder cylinder (2), the cylinders being fluid dynamic (5), pneumatic or hydraulic cylinders in the case of the die (1) being rotating. A system for fixing rotating dies on die cutting machines of laminar material according to the first claim, characterized in that the bolts (3) are quincuncially placed on the rotating cylinder or on a flat surface. A system for fixing rotating dies on die cutting machines of laminar material according to the first claim, characterized in that it is provided with threaded drills (22) to fix the rotating die (1) to the die holder cylinder (2). A system for fixing rotating dies on die cutting machines of laminar material according to the previous claims, characterized in that the drills (22) are also quincuncially placed on the rotating die (1), occupying the locations not occupied by the bolts (3). A system for fixing rotating dies on die cutting machines of laminar material according to the previous claims, characterized in that it has springs (13) and (14) acting on the bolt (3), the latter being located inside the hollow piston (6) when the outlet of the bolt (3) is obstructed by the die (1). A system for fixing rotating dies on die cutting machines of laminar material according to the previous claims, characterized in that the die (1) is centered on the die holder cylinder (2). A system for fixing rotating dies on die cutting machines of laminar material according to the previous claims, characterized in that it has a circumferential butt (19) and an axial butt (20) on the die holder cylinder, and a reglet (21) on the die (1) for centering it. A system for fixing rotating dies on die cutting machines of laminar material according to the previous claims, characterized in that it has a hole (15) with a swivel (16) and a recess (17) carried out on the wood of the die so that after shifting the wood and removing the air from the pneumatic cylinder (5), the bolt's (3) head (7) fixes the die (1) against the die holder cylinder (2).

Inventors: SERRA OBIOL RAMON, SERRA OBIOL, RAMON
Applicants: COM IND MAQUINARIA CARTON ONDU, COMERCIAL INDUSTRIAL MAQUINARIA CARTON ONDULADO S.A. - CIMCOSA
Application year: 1999
Main classification: B26D7
IPC codes: B26F1, B26D7