Front positioning device of a sheet by mark printed on the feeding station of a die cutting machine

摘要

1. Device front positioning a sheet (1) by mark printed on the feeding station of a punching machine, comprising a feed table (2) capable of transporting a sheet (1) by at least one conveyor belt (3 ), at least two movable front stops (4) for impeding movement of the blade (1) in the feeding direction (X) on the table (2), traction means (5) for moving said front stops ( 4) for rectifying the position of the sheet (1) before being delivered to the subsequent cutting station the stamping machine, media capture (6) provided for detecting the passage of marks front printing on sheet (1) during the displacement thereof, and control means (8) for managing the movement of the traction means (5) to execute a correction of the positioning of the blade (1), characterized d and that the front stops (4) are moved by the traction means (5) according to a corrective movement or positioning (X '), in the same feeding direction (X) of the blade (1), defined according to information detected by the means of capturing images (6) and the feed rate of the table (2), such that said sheet (1) is capable of being positioned with their marks front print arranged in a position preset, calculated according to the distance between said front print marks and the front margin of the sheet (1), through a corrective strategy drawn up by the control means (8). 2. Device according to claim 1, wherein said correction strategy is defined by creating a motion profile X 'can first position the front stops (4) in a closer position to the sheet (1) when it has not yet reached said front stops (4), then initiate the displacement of said front stops (4) along the path (X ') in the same sense of self-feeding motion (X) but at a speed slightly below the leaf (1) until said sheet (1) contacts the front stops (4), and finally stop said front stops (4) in the position desired correction, in accordance with a reading error "e" detected by means imaging (6). 3. Device according to claim 1 or 2, further comprising auxiliary guide means (7a, 7b) intended to maintain contact of the blade (1) with the front stops (4). 4. Device according to claim 3, wherein the auxiliary guide means include a group of upper support strips (7a) and a group of rubber wheels or brushes (7b). 5. Device according to claim 4, wherein the group of rubber wheels or brushes (7b) is arranged directly behind the sheet (1) once said sheet (1) has been positioned by the front stops ( 4), so that said group of rubber wheels or brushes (7b) is in turn susceptible to push the sheet (1) against front stops (4) by the action of at least one conveyor belt (3) or the subsequent sheet is lagging behind the first sheet (1). 6. Device according to claim 4 or 5, wherein the group of upper support strip (7a) is located near the front stops (4), so that said group of strips (7a) is able to prevent the sheet (1) bend or mount above the front stops (4) due to the same thrust action group rubber wheels or brushes (7b). 7. Device according to claim 6, wherein the group of upper support straps (7a) further includes a front strip (9) intended to wrap around the front stops (4) at all times, and a rear strap (10) provided to ensure that the blade (1) is parallel to the image capture means (6) at the time of passage of said sheet (1) below said image capture means (6). 8. Device according to claim 5, wherein the group of rubber wheels or brushes (7b) comprises wheels (11) arranged just above the opposite front margin of the sheet (1), so that each wheel (11) is capable of being located slightly above the sheet (1) when said sheet (1) has been set in the position correction by the front stops (4), and so that each wheel (11) do not lose contact sheet (1) provided that the value of error correction "e" is within tolerance limits. 9. Device according to claim 8, wherein the group of rubber wheels or brushes (7b) further includes second wheels (12) located directly behind the respective front wheels (11) with respect to the direction of advance, being both wheels (11, 12) by a strap or belt carrier (13), to better utilize the same movement transmitted by the at least one conveyor belt (3) or subsequent sheets circulating in the table ( 2). 10. Device according to claim 8 or 9, wherein the wheels (11, 12) include a regulating pressure (14) exerting said wheels (11,12) on the blade (1) so that the pressure can be adjusted according to the characteristics of said sheet (1). 11. Device according to claim 3, wherein the auxiliary guide means (7a, 7b) are fixed relative to the die cutting machine, and include means for manual adjustment according to the thickness and sheet format (1) .