Locking device structure particularly for traction-fed cardboard

Abstract: The locking device structure includes a polygonal plate (12a) having a counter roller (18) pivoted thereto, the counter roller (18) being arranged above a driven roller (4). An actuation piston (6) is pivoted to an upper corner of the plate (12a), which is also provided at a lower corner with a presser plate (16). Extension of the piston (6) provides traction feeding of cardboard (14) between the rollers (4,18) whereas retraction of the piston (6) releases the traction and further blocks the feed of cardboard (14) due to engagement of presser plate (16) on abutment surface (19).

Description: The present invention relates to a locking device structure, particularly usable in cardboard processing machines during said cardboard traction feeding. Machines suitable for performing a plurality of processes on corrugated cardboard are already currently known. On the subject, the same Applicant filed March 9, 1987 a European patent application No. 87103312.2, publication No. 0247300, related to an automatic machine for processing corrugated paper, constituted by a first station for multiple feeding of corrugated cardboard, with the possibility of different widths, a second station for inserting the corrugated cardboard, a third station for cutting the cardboard, a fourth station for scoring the cardboard, a fifth station for dinking the cardboard and a sixth station for removing the cardboard and for the eventual gluing and folding of the flaps resulting from the manufacturing process. Thus, this solution provides the presence of a station for the feeding of cardboard which essentially comprises a supporting frame; the shafts of three rolls, each constituted by corrugated cardboard with different width and/or length, are freely pivoted to the side members of said supporting frame. This solution has thus allowed to solve the problem related to the selective feeding of cardboard starting from rolls according to different dimensions, such as width and length. However, the insertion system is expensive from both a mechanical and electrical-electronic viewpoint. US-A-4792074 discloses an arrangement for the stepwise feed of band material which includes a first, locally fixed and driven feed roller and a second feed roller rotatably supported by a rocker; the rocker is loaded by a spring; a lifting mechanism is provided, by which the second feed roller is movable at the point in time of the reversal of the direction of rotation toward the first feed roller for an advance of the band material and away form the same into a return position in which the band material is to be held fixed. The locking of the band material is achieved by an actuator which actuates a series of levers connected to a pressure device which abuts against the band material that in turn abuts against a counter element. DE-B-1144577 discloses a feeding device for cardboard sheet or the like, particularly for punch cutter apparatuses. The device comprises two compressed air driven actuators (16, 18) provided with two pistons (15, 17); the piston (17) of the actuator (18) carries an abutment element suitable to stop the feeding of the cardboard sheet in a predetermined position, while the piston (15) of the actuator (16) actuates a first roller (11) that is opposed to a second roller (13) to engage the cardboard therebetween. The aim of the present invention is to stop the advancement of the cardboard unrolled from an inserter or reel-holder or from a fanfold pack, or from individual or pasted sheets, after the operation of cutting said cardboard. An object of the present invention is to provide a device which allows both to achieve optimum feeding of cardboard and to feed said cardboard at one or more successive stations in the optimum position, although the cardboard is subjected to various and distinct processing steps. Within the scope of the above described aim and objects, another important object is to provide a device which prevents the extraction or escape of the cardboard from the traction rollers of the inserter while said cardboard is subjected to one or more successive processing operations. Another important object is to provide a device which allows to contain manufacturing costs especially as regards the use of motorization systems. Still another important object is to provide a device which associates with the preceding characteristics that of being reliable and safe in use. Not least object is to provide a device which is structurally simple, is easy to apply even to known machines, and at the same time has modest manufacturing costs. This aim, these objects and others which will become apparent hereinafter are achieved by a locking device structure for locking particularly during cardboard traction according to the appended claims. Further characteristics and advantages of the invention will become apparent from the detailed description of a particular embodiment, illustrated only by way of non-limitative example in the accompanying drawings, wherein: figure 1 is a front elevation view of the locking device structure according to the invention; figure 2 is a side elevation view thereof. With reference to the above figures, the locking device structure, generally indicated by the reference numeral 1, comprises a fixed support, such as a pair of shoulders 2a and 2b, between which a first roller 3 is freely pivoted; said first roller is motorized by a single source, such as an adapted motor, not illustrated, which is suitable for providing motion to said first roller 3, a gearwheel 5 being keyed at its first shaft 4. The structure is furthermore constituted by at least one actuator, constituted by a piston 6, the body 7 whereof is pivoted, at one end, at an arm 8 which protrudes from a base support 9 which can be rigidly associated at the shoulder 2a. The piston 6 furthermore has a stem 10, the end portion 11 whereof is U-shaped; one of two polygonal plates 12a and 12b is freely pivoted, proximate to an edge, between the wings of said end portion. Said plates, which are respectively adjacent to the shoulders 2a and 2b, have a lower perimetric edge 13a and 13b which is arranged proximate to the plane of arrangement of the underlying cardboard sheet 14, which in turn rests at the surface of the underlying first roller 3. Said plates 12a and 12b, which preferably have a rhomboidal plan configuration, are in turn pivoted, by means of a pair of first pivots 15a and 15b, respectively to said shoulders 2a and 2b proximate to the corner which is opposite to the pivoting corner of said end portion 11 of the stem 10. Both of said plates 12a and 12b have, at the corner for pivoting to said first pivots 15a and 15b, an end on which a plate or presser 16 is fixed transversely to the plates 12a and 12b; said presser has a lanceolate configuration and is directed opposite to the direction of removal of the cardboard sheet 14. Structurally, the axis of the first shaft 4 of the first roller 3 is interposed between the axes for the pivoting of the end portion 11 and of the stem 10 to the plates 12a and 12b and the axis of the first pivots 15a and 15b; a second shaft 17 of a second counter-roller 18 is pivoted to said plates 12a and 12b at said first roller 3. At least one abutment surface 19 for said cardboard sheet is provided below the plane of arrangement of the cardboard sheet 14 at the presser or plate 16 which connects the plates 12a and 12b. The use of the structure is in fact as follows: since the first roller 3 always rotates, traction of the cardboard sheet 14 can be allowed only if the piston 7 is actuated, pushing the stem 10 toward said cardboard so as to cause the surface of the second counter-roller 18 to interact with said cardboard sheet 14 which, by resting at the first roller 3, is pushed thereby for processing in subsequent stations. In this condition, illustrated in figure 2, the presser or plate 16 connected to the plates 12a and 12b is arranged approximately parallel to the plane of arrangement of the cardboard sheet 14 and said plates do not interact with said sheet. When the cardboard is to be processed in the subsequent stations, the piston 6 is actuated, preferably before the step of cutting said cardboard, so as to retract the stem 10, thus disengaging the second counter-roller 18 from the cardboard sheet 14 and simultaneously causing the presser 16 to interact with said cardboard sheet, which is pressed at the underlying abutment surface 19. In this manner, the traction of the cardboard sheet is stopped on one hand and said sheet is locked on the other, preventing its escape or extraction. It has thus been observed that the invention has achieved the intended aim and objects, a structure having been provided which allows to obtain the optimum traction of a cardboard sheet, thus achieving optimum feeding at modest manufacturing costs, allowing at the same time to lock the traction of the sheet, preventing the extraction thereof, if it is necessary to process said cardboard in adjacent stations of a more complicated machine which also provides, for example, the cutting of the cardboard in one of its operating steps. It is thus possible to simultaneously stop the traction of the cardboard sheet and lock it if it is to be processed in subsequent stations, the presence of the presser 16 preventing any extraction of said cardboard. The invention is furthermore structurally very simple, as well as easy and rapid to install even in known machines, and at the same time has very modest manufacturing costs which allow to considerably contain the machine manufacturing costs. The number of pistons, dimensions of the plates and configurations of the wings and of other components, as well as the materials used for manufacture, may naturally be the most pertinent according to the specific requirements. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims: Locking device structure, particularly for traction-fed cardboard, comprising support means (2a, 2b), a first motorized roller (3) supported by said support means, a second counter-roller (18), at least one abutment face (19) provided below the plane of arrangement of a cardboard sheet, and at least one actuator (6), characterized in that said actuator (6), at one end thereof, is coupled to an end of one of said support means (2a, 2b), and at the other end thereof is pivoted to at least one plate (12a, 12b) which is pivoted to said supporting means (2a, 2b), said at least one plate (12a, 12b) being arranged proximate to the plane of arrangement of an underlying cardboard sheet (14) abutting on the surface of said first motorized roller (3), said at least one plate (12a, 12b) being connected at a corner thereof, opposite to the corner to which said actuator (6) is connected, to a presser (16), said at least one plate (2a, 2b) being further connected to said second counter-roller (18), said actuator being adapted to be pushed toward said cardboard sheet causing said second counter-roller (18) to contact said cardboard sheet, which in turn contacts said first motorized roller (3), so as to feed the cardboard sheet, and being adapted to be lifted so as to lift the counter-roller (18) and lower the presser (16) to simultaneously stop and lock the cardboard sheet (14), said presser (16) pressing said cardboard sheet against said at least one abutment face (19) preventing the extraction thereof. Locking device structure according to claim 1, characterized in that said support means (2a, 2b) comprise a pair of shoulders (2a, 2b), between which said first motorized roller (3) is freely pivoted, said first roller (3) being motorized by a single adapted motor suitable for providing motion to said first motorized roller (3) by means of a gearwheel (5) keyed to a first pivoting shaft (4) for said first motorized roller (3). Locking device structure according to claim 1, characterized in that said at least one actuator (6) comprises a piston (6) the body (7) whereof is,, at one end, pivoted at an arm (8) protruding from a support base (9) which is rigidly connected to one of said shoulders (2a, 2b). Locking device structure according to claim 3, characterized in that said piston (6) has a stem (10) the end portion (11) thereof being U-shaped, said U-shaped end portion (11) accommodating therein said at least one plate (12a, 12b), said plate being freely pivoted proximate to an edge between the wings of said end portion (11). Locking device structure according to claim 1, characterized in that it comprises a pair of plates (12a, 12b) connected together at a lower edge thereof by said presser (16). Locking device structure according to claim 5, characterized in that said plates (12a, 12b) have a rhomboidal plane configuration. Locking device structure according to claims 2 and 4, characterized in that said plates (12a, 12b) are pivoted respectively to said shoulders (2a, 2b) by means of a pair of first pivots (15a, 15b) proximate to the corner opposite to the pivoting corner of said end portion (11) of said stem (10). Locking device structure according to claims 1 and 2, characterized in that said plates (12a, 12b) arranged adjacent so said shoulders (2a, 2b) have a lower perimetric edge (13a, 13b) arranged proximate to the plane of arrangement of said underlying cardboard sheet (14), which in turn rests at the surface of said first motorized roller (3). Locking device structure according to claim 1, characterized in that said presser (16) has a lanceolate configuration and is directed opposite to the direction of removal of said cardboard sheet (14). Locking device according to claim 1, characterized in that said presser (16) has a length that is equal to or greater than the length of said first (3) and second (18) rollers.

Inventors: FABRIS BRUNO, FABRIS, BRUNO
Applicants: IMMOBILIARE PANOTEC SRL, IMMOBILIARE PANOTEC S.R.L.
Application year: 1991
Main classification: B65H20
IPC codes: B65H20