Title of Invention

"METHOD AND STATION FOR UNBLANKED SHEET DELIVERY IN A MACHINE PROCESSING PLATE ELEMENTS"

Abstract

This method for unblanked sheet delivery comprises a delivery pullout frame (2) provided with jogging stops (3) and transverse gripper bars (5), the respective ends of which are fixedly attached to two respective flexible drive elements (4a,4b) in the shape of endless loops for conveying the sheets in process. The front jogging stops (3) of the said delivery pull-out frame (2) are spaced so as to allow the passage between them of the grippers (5a) of the gripper bar (5) and the gripper bar is inclined around a transverse shaft (7), for lowering the level of the said grippers (5a) below the level of the respective upper edges of the said front stops (3), by simultaneously opening the said grippers (5a), in order to separate the said sheet from the said grippers (5a) by bringing its front edge against the said front stops (3).

Full Text

METHOD AND STATION FOR UNBLANKED SHEET DELIVERY IN A MACHINE PROCESSING PLATE ELEMENTS The present invention refers to a method and a station for unblanked sheet delivery in a machine processing plate elements, comprising a delivery frame provided with jogging stops and transverse gripper bars, the respective ends of which are fixedly attached to two respective flexible drive elements in the shape of endless loops for conveying the sheets in process. When diecutting cardboard sheets or plates in a diecutting press, it is possible, according to the kind of job carried out in the press, to collect the blanks separately in the form of distinct piles or to deliver the unblanked sheet, particularly if to be processed in another machine, after the sheet diecutting operation and before the blanking operation. In the first case, the front edges of the respective sheets remain seized in the grippers of the gripper bar of the sheet conveying device and the waste of the sheet, after the blanking operation, is driven by the gripper bar towards the waste removal station. In the second case, the sheet is released by the gripper bar and a stripper pushes it backwards by coming against its front edge in order to take it out of the grippers and stack it on a single storage pile formed between the vertical jogging stops adjusted to the size of the sheets to be stacked. The use of a conventional stripper is necessary to stop the sheet in order to take it out of the grippers of the gripper bar. However, the stripper has to be moved in opposite direction to the sheet in order to encounter it by passing between the grippers of the gripper bar at the time when these grippers open, that is the reason of the back motion imparted to the sheet when stopping. Considering the kinetic energy of the sheet at the time of encountering the stripper, this abrupt stopping with back motion causes a deformation of the sheet propagating like a wave through it. This deformation wave risks to break the nicks connecting the previously diecut blanks to the sheet or even connecting them together, which, obviously, is undesirable since these nicks should keep the sheet entire, despite the diecutting of the blanks, until to the time chosen for separating them. The aim of the present invention is to reduce the deformation of the sheets at the time of their stopping for stacking them in the delivery frame of the delivery station of the processing machine. To this end, this invention firstly refers to a method for unblanked sheet delivery in a delivery station of a machine processing plate elements according to claim 1. This invention also refers to a station for unblanked sheet delivery in a machine processing plate elements according to claim 2. In the method of the present invention, the sheet stripper is omitted, so that the sheets are no more subject to a back motion transmitted by this stripper. This method for unblanked sheet delivery substantially reduces the deformation of the sheet induced by its deceleration at the time of its stopping, insofar as it is no more subject to a back motion and, consequently, to the risk of breaking the nicks connecting the blanks diecut into the sheet. Advantageously, the first and second cams of the delivery station are mounted removable with respect to the path of the said gripper bars so that this station can operate according to the blanking method, in which the grippers of the gripper bars must remain closed in order to remove the waste portion of the sheet fixedly attached to the grippers of the gripper bar. The accompanying drawing illustrate, schematically and by way of example, an embodiment of a delivery station in a sheet processing machine, object of the present invention, adapted to the working of the method, another object of this invention. Fig. 1 is a partial perspective view of this station for unblanked sheet delivery; Fig. 2 is an enlarged lateral view of a detail of Fig. 1. By way of introduction to the following description it is specified that the terms sheet, plate or plate element are indistinctly used for paper, cardboard or corrugated cardboard, plastic or laminated sheets. The processing machine is in particular a machine for diecutting blanks into plate elements. Due to the fact that both sides of the station for unblanked sheet delivery of the described machine are symmetrical, or at least the elements necessary for the understanding of the invention, only the operator's side of this delivery station is shown in Fig. 1 and is described. The reference numerals of the elements which exist on both sides of the delivery station are added by the letters "a" for the elements on the operator's side, respectively "b" on the opposite operator's side. For this reason, the reference numerals added by the letter "b" are not shown in the drawing but are given in the text in order to mention the elements which are symmetrical to those shown on the operator's side of the delivery station. The delivery station SR of the machine processing plate elements, partially illustrated on Fig. 1, includes a frame 1 on which is slidably mounted a pull-out frame 2 for unblanked sheet delivery provided with front jogging stops 3 which are spaced from one another for the passage of the grippers of the gripper bar, as will be explained afterwards. This pull-out frame 2 is slidably mounted on the support for receiving the lower blanking tool, when the delivery station is not delivered with unblanked sheets but with separated sheets. The frame 1 further carries two parallel endlass chains 4a, 4b laterally arranged on both sides of the path of the sheets in the processing machine. These chains 4a, 4b are conventionally engaged with chain wheels (not shown) and are driven by one of them engaged with the drive motor (not shown) of the machine. These chains 4a, 4b are fixedly attached to the two respective ends of gripper bars 5 which transversely extend to the path of the sheets in the processing machine and hence parallelly to the transverse edges of these sheets. The grippers 5a of the gripper bar 5 are directed backwards of the gripper bar with respect to the conveying direction F of these sheets and are used for seizing the front edges of the sheets in order to convey them through the processing machine. The lower arms of these grippers 5a are fixed whereas their upper arms are fixedly attached to a transverse support shaft 7. The connection between the ends of the gripper bar 5 and the chains 4a, 4b is obtained by two respective connecting pieces 1a, 11b which are also used as swivelling bearing for the respective ends of the transverse support shaft 7 which further passes into supporting bearings (not shown) distributed along the gripper bar 5. The upper arms of the grippers 5a are elastically pressed in closing position of the grippers 5a by pull-back springs 12. The station SR for unblanked sheet delivery includes, on the respective paths of two rollers 7a, 7b carried by the ends of the support shaft 7 of the grippers 5a of the gripper bar 5 and at the downstream end of this station, two lowering cams 6a, 6b of the support shaft 7 of the gripper bar 5. Said lowering of the support shaft 7 causes a traction on the chains 4a, 4b so that the rear part of the gripper bar 5 can be lowered by some mm. The chains 4a, 4b are guided by the chain wheels (not shown) and also by fixed guides 8a, 8b which are arranged on the internal side of the paths of these chains 4a, 4b, at the exit of the delivery station SR, where the respective paths of these chains 4a, 4b become incurved. The downstream transverse part of the puil-out frame 2 carries at least one, preferably two lower cams 9a, 9b for opening the grippers 5a of the gripper bar 5. These lower cams 9a, 9b are respectively arranged near the ends of this downstream transverse part of the pull-out frame 2, on the respective paths of two opening rollers 10a, 10b of the upper arms of the grippers 5a. These opening rollers 10a, 10b are pivotally mounted on axes 16a, 16b parallel to the support shaft 7 of the upper arms of the grippers 5a of the gripper bar 5, and are attached by a lever 15 to the support shaft 7, so as to turn it around its longitudinal axis by driving the upper arms of the grippers 5a, against the pressure of the pull-back springs 12 and to space these upper arms from the lower arms, as particularly illustrated by Fig. 2. It should be noted that the upper cams 6a, 6b are located at such a level that the rear ends of the grippers 5a pass below the upper edges of the front jogging stops 3 of the pull-out frame 2 for unblanked sheet delivery, as particularly illustrated by Fig. 2. The level of the lower cams 9a, 9b is also chosen so that the lowering of the rear part of the gripper bar 5 presses the opening rollers 10a, 10b of the grippers 5a against the lower cams 9a, 9b, causing the opening of the grippers 5a at the time of their passage between the front jogging stops 3. Therefore, the sheets kept by the grippers 5a are stopped by the jogging stops 2 which are static, contrarily to the strippers which move in opposite direction to the sheets. Consequently, owing to the method for unblanked sheet delivery according to the invention, the lowering of the rear part of the gripper bar 5 allows opening of the grippers, what is per se made on all gripper bars, but the novelty is due to the fact that this opening is obtained when the grippers 5a of the gripper bar 5 are at the same time lowered and pass between the front jogging stops 3 of the pull-out frame 2, allowing to these jogging stops 3 to additionally act as statical stripper of the unblanked sheets. This stripping method substantially reduces the deformation wave of the sheet, arising from its stopping, due to the fact that only the sheet is moving whereas the stops 3 are fixed, contrarily to the conventional stripper which moves in opposite direction to the sheet. When the station is used for the delivery of blanks which are diecut in the sheet in the form of separated blanks, the pull-out frame 2 must be laterally taken out of the machine and replaced by the lower blanking tool. Since the lower cams 9a, 9b for opening the grippers 5a of the gripper bars 5 are fixedly attached to the pull-out frame 2, its removal also causes the removal of these cams 9a, 9b. On the other hand, the upper cams 6a, 6b for lowering the support shaft 7 of the grippers 5a of the gripper bar 5 have to be retracted in order to prevent a collision of the gripper bars 5 with the lower blanking tool. To this end, each upper cam 6a, 6b is attached to the frame 1 by a swivelling axis 13. Two threads (not shown) provided in the frame and located on an arc of a circle centred on the swivelling axis 13 of each upper cam 6a, 6b are aimed at selectively receiving a threaded rod 14 controlled by a handle 14a fixedly attached to its external end. When the respective threaded rods are screwed by means of the handles 14a into the respective lower threads of the frame, the upper cams 6a, 6b are in their respective lowered positions, corresponding to the unblanked sheet delivery. When the same threaded rods 14 are screwed into the upper threads of the frame, the cams 6a, 6b are in their raised positions and do not come into contact with the gripper bars 5, corresponding to the separated blank delivery. Even if manually controlled means for activating or desactivating the cams 6a, 6b for lowering the gripper bar have been described hereinbefore, instead of the manual control, a cylinder or motor control, for example, could be used. Likewise, any other type of manual control than the described one could also be used. We Claim: 1. A delivery Station for unblanked sheet delivery of a machine processing plate elements, comprising a delivery pull-out frame (2) provided with jogging stops (3) and transverse gripper bars (5), the respective ends of which are fixedly attached to two respective flexible drive elements (4a,4b) in the shape of endless loops for conveying the sheets in process, characterized in that it has at least one first cam (6a, 6b) for lowering the grippers (5a) of the gripper bar (5) below the respective upper edges of the front jogging stops (3) of the delivery frame (2) and at least one second cam (9a, 9b) for opening the said grippers (5a) in their lowered position. 2. Delivery station as claimed in claims 1, wherein the first and second cams (6a, 6b; 9a, 9b) are mounted removably with respect to the path of the said gripper bars (5) to allow operating according to a blanking method. 3. Delivery station as claimed in claims 1 or 2, wherein the said second cam (9a, 9b) is fixedly attached to the delivery pull-out frame (2), mounted removably in the said station. 4. A Method for unblanked sheet delivery, in a delivery station of a machine processing plate elements as claimed in claim 1, characterized in that the front jogging stops (3) of the said delivery pull-out frame (2) are spaced so as to allow the passage between the grippers (5a) of the gripper bar (5) and the gripper bar is inclined around a transverse shaft (7), for lowering the level of the said grippers (5a) below the level of the respective upper edges of the said front stops (3), by simultaneously opening the said gripper (5a), in order to separate the said sheet from the said grippers (5a) by bringing its front edge against the said front stops (3).

Documents:

2534-DEL-2005-Abstarct-(07-09-2009).pdf

2534-del-2005-abstract.pdf

2534-DEL-2005-Assignment-(07-09-2009).pdf

2534-DEL-2005-Claims-(07-09-2009).pdf

2534-del-2005-claims-(08-04-2010).pdf

2534-del-2005-Claims-(09-04-2010).pdf

2534-del-2005-claims.pdf

2534-DEL-2005-Correspondence-Others (02-02-2010).pdf

2534-DEL-2005-Correspondence-Others-(07-09-2009).pdf

2534-del-2005-correspondence-others-(08-04-2010).pdf

2534-del-2005-Correspondence-Others-(09-04-2010).pdf

2534-del-2005-correspondence-others.pdf

2534-del-2005-description (complete).pdf

2534-DEL-2005-Drawings-(07-09-2009).pdf

2534-del-2005-drawings.pdf

2534-DEL-2005-Form-1-(02-02-2010).pdf

2534-DEL-2005-Form-1-(07-09-2009).pdf

2534-del-2005-form-1.pdf

2534-del-2005-form-13.pdf

2534-del-2005-form-18.pdf

2534-DEL-2005-Form-2-(07-09-2009).pdf

2534-del-2005-form-2.pdf

2534-DEL-2005-Form-26-(02-02-2010).pdf

2534-DEL-2005-Form-26-(07-09-2009).pdf

2534-del-2005-form-26.pdf

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