Device for application in paperboard or other material processing machines for preventing main shafts from bending

Abstract

 A device for application to operating machines for processing paperboard or corrugated paperboard or other materials in sheet or strip form, and designed for preventing main shafts of said machine from bending, is characterized in that said device comprises a supporting bar for the shaft supporting assembly, which supporting bar is arranged in a longitudinal direction, with respect to the paperboard material feeding direction, and being supported by cross members in turn applied, at their end portions, to the main shoulders of the machine, and at the central part thereof being supporting by supporting uprights and elements bearing on the floor.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a device designed for application to operating machines for processing paperboard or other materials, in sheet or strip form, which is adapted to prevent main operating shafts from bending, such as, respectively, counter-precreasing, counter-slitting and counter-creasing shafts.

[0002] As is known, the above mentioned main operating shafts, mainly in machines designed for processing corrugated paperboard of substantial width, are subjected to a natural bending.

[0003] The latter is more sensitive at the center of the paperboard strip and is caused by the weight of the operating shafts supporting related operating disc elements.

[0004] This drawback is further aggravated during the paperboard material processing, because of the stresses exerted at a lot of different points of the operating shafts by the paperboard material being handled or processed.

[0005] More specifically, such a processing resistance is applied by the paperboard material against the counter-slitting, counter-precreasing and counter-creasing disc elements which are supported by the mentioned main operating shafts.

[0006] Prior paperboard material handling or processing machines, and in particular available machines for processing corrugated paperboard, which are specifically designed for handling paperboard strips of a comparatively large width, are affected by great operating drawbacks, in consequence of the above mentioned flexure strains of the main operating shafts.

[0007] The above drawbacks so negatively affect the mentioned precreasing, slitting and creasing operations that the corrugated paperboard being processed will have, at the end of the processing procedure, a lot of portions thereof with different depth values.

[0008] In particular, the corrugated paperboard material will have, at a center thereof, different depth precreased and creased portions, which will negatively affect following folding operations for forming, for example, boxes, and this particularly in automatic systems for packaging products into paperboard boxes.

[0009] The above mentioned drawback can be partially compensated for by using main operating shafts of greater diameter and thickness, which, however, will have a larger weight, in turn contributing to the above mentioned bending problem.

[0010] Moreover, greater diameter shafts would involve an increase of the diameter of the processing discs, with a consequent increase of the distance of the shafts, and, accordingly, of the minimum length of the sheet to be handled.

SUMMARY OF THE INVENTION

[0011] Accordingly, the aim of the present invention is that to overcome the above mentioned drawbacks, by providing a device specifically designed for preventing main operating shafts from bending which is very simple construction wise and can be quickly applied to existing paperboard material processing machines.

[0012] The above mentioned aim, as well as yet other objects, which will become more apparent hereinafter, are achieved by a device according to claim 1.

[0013] Further characteristics of the inventive device being defined in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above mentioned and other features of the device according to the present invention will become more apparent hereinafter from the following detailed disclosure with reference to the figures of the accompanying drawings, where:

Figure 1 is a schematic overall view of the machine according to the invention;

Figure 2 is a side view of the machine shown in figure 1;

Figure 3 is a further side view illustrating the device designed for preventing main operating shafts from bending;

Figure 4 is an elevation cross-sectional view illustrating a detail of the subject device;

Figure 5 shows a detail of a supporting bar of the shaft supporting device, with a related linear guide for supporting a sliding block or shoe assembly, and

Figure 6 is a cross-sectioned top plan view of a detail of the sliding block as applied to the device of figure 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] With reference to figure 1, is herein shown, in a schematic manner, an operating machine 100 for processing corrugated paperboard, to which the device according to the present invention must be applied.

[0016] More specifically, figure 1 shows said operating machine 100 for processing a corrugated paperboard material 81, which machine comprises slitting knives 78, which are rotatively driven by motor driven shafts.

[0017] Moreover, conveying belts 77 driven by a driving shaft 83 are provided.

[0018] The slitting knives 78 operate in cooperation with counter-slitting knives 79, thereby suitably slitting and trimming a corrugated paperboard material sheet 81.

[0019] Figure 1 shows furthermore a supporting shaft 11, supporting a plurality of counter-slitting disc elements 79 including a plurality of related grooves.

[0020] As stated, the above operating shafts tend to bend because of the stress applied thereto by the belts 77 operating in cooperation with the flat portion of the counter-slitting elements 79, in the presence of a corrugated paperboard sheet 81 which is entrained for processing it.

[0021] The operating machine shown in figure 1 comprises a geared motor unit 85, driving a shaft 86 which, through related gears 87 and toothed sectors 96, rotatively drives eccentric bushes 90 arranged at end portions thereof, provided for adjusting the thickness or spacing between the counter-slitting elements 79 supported by the shaft 11, and the top belts 77.

[0022] On the top thereof, the operating machine comprises furthermore a further operating shaft, provided for causing the supporting elements 82 supporting the slitting discs 78 and related pulleys and belts 77 to axially slide in a horizontal direction.

[0023] Figure 1 shows moreover a supporting bar 3, to which a linear guide 23 is applied, thereon is slidably supported a shoe or sliding block 24 in turn supporting an oleodynamic cylinder 6, on the top of which a cradle 16 is applied.

[0024] The top shaft 83 rotatively drives the belts 77 and related pulleys, which are supported by the supporting elements or arms 82 through pivots 84, thereabout said slitting disc elements 78 are rotatively driven.

[0025] Figure 2 shows a side view of the shafts supporting the slitting discd 78, counter-slitting discs 79, eccentric bushes 90, toothed or gear sectors 96, gears 87, precreasing assembly 92, counter-precreasing assembly 94, creasing assembly 93 and counter-creasing assembly 95.

[0026] Figure 2 schematically shows moreover an operating machine including pairs of opposite shafts 11, 11', 12, 12', 13, 13', 14 and 14', to which the device to be hereinafter disclosed can be applied.

[0027] Figures 1 and 2 show, in a schematic manner, an operating machine 100 for processing corrugated paperboard material, to which machine the subject device will be applied.

[0028] More specifically, the slitting disc elements 78 operate in cooperation with counter-slitting discs 79, thereby properly cutting and trimming a corrugated paperboard sheet 81.

[0029] Figure 1 shows a supporting shaft 11 which supports the grooved counter-slitting knives.

[0030] In particular, the shafts 11, 11', 12, 12', 13, 13', 14 and 14' will tend to bend because of the pressure provided by the slitting discs 78 operating against the counter-slitting discs 79, in the presence of a corrugated paperboard sheet 81 being processed.

[0031] Figure 3 shows a supporting bar 1, designed for supporting the oleodynamic cylinders 6, on the top of which are applied the cradles 16.

[0032] To said supporting bar 1, shoes or sliding blocks 24 sliding on linear guides 23 applied to the supporting cross-members 2 and 3 are connected.

[0033] Figure 3 and the following figures show the device according to the invention, designed for application to machines for processing corrugated paperboard sheets 21 and for preventing the main shafts 11, 11', 12, 12', 13, 13', 14 and 14' from being bent, which device comprises a supporting bar 1, for the device supporting the shafts 11, 12, 13 and 14, which supporting bar is arranged in a longitudinal direction with respect to the corrugated paperboard material 81 feeding direction.

[0034] Said supporting bar 1 is in turn supported by two cross-elements shown in figure 3 and generally indicated in this figure by the reference numbers 2 and 3.

[0035] The side cross-members 2 and 3 are applied, in turn, at their end portions, to the main shoulders of the machine and are supported, at a central part thereof, by uprights 4 bearing on the ground.

[0036] The supporting bar 1 houses and supports, in turn, a plurality of hydraulic jacks 6, coupled to an oleodynamic pump 8 through coupling tubes 7 for supplying a hydraulic operating fluid.

[0037] The pump 8 is coupled, through the coupling tubes 7, to a solenoid valve assembly 10, the solenoid valves of which are controlled by a pressure switch 9, designed for adjusting the fluid pressure which will set the pushing force of the operating jacks 6.

[0038] The oleodynamic pump 8, pressure switch 9 and solenoid valves 10 supply, with a constant fluid pressure, the jacks 6 each of which will urge related supporting members of each main shaft 11, 12, 13 and 14.

[0039] Thus, the flexure strain due to the weight of the mentioned shafts, supporting said operating discs will be compensated for, thereby preventing further strains due to the passage of the paperboard material 81 during the precreasing, creasing and slitting operations thereon.

[0040] More specifically, each hydraulic jack 6 support a bottom lug element 15, preferably of curved configuration, rigid with a cradle 16 which can follow a vertical movement, thereby being suitably raised and lowered.

[0041] Each said cradle 16 is laterally guided by a pair of guiding elements 17 and side restraining plates 75.

[0042] The guiding elements 17, plates 75 and supporting bar 81 are bolted or coupled by any other suitable coupling means to one another, to provide a monolithic bearing construction, adapted to resist against high stresses as applied thereto by the main shafts 11, 12, 13 and 14, during the processing steps.

[0043] With reference to figures 3, 4 and 5, they show the driving shafts 19 for driving the mentioned eccentric bushes, which are designed for adjusting the distance between the shafts supporting the mentioned counter-precreasing, counter-slitting, counter-creasing, precreasing, creasing discs as well as the top driving belts 77 arranged in an adjoining relationship with the slitting blades, depending on the thickness of the paperboard material to be processed.

[0044] Each cradle 16 supports, in turn, a bearing 20 which is held in a set position by side pairs of holding sectors 18.

[0045] Each bearing 20, in turn, supports a shaft 11, 12, 13 and 14, through the interposition of a bushing 22, providing an anti-seizing function, during the location operations.

[0046] The mentioned bushing 22 is held in a set position therefor by resilient ring elements 21.

[0047] As shown, the cross members 2 and 3 are preferably provided with linear guides 23 and shoes or sliding blocks 24.

[0048] The linear guides 23 support the sliding blocks 24 which in turn support the supporting bar 1, to allow the overall system to be axially driven, in order not to limit the locating flexibility and operating flexibility of the operating machine.

[0049] The axial displacement of the subject device can be carried out by mechanical driving elements in turn driven by electric motors or oleodynamic pistons or manual adjustable systems.

[0050] In this connection it should be pointed out that the main shafts 12 and 14 can alternatively support the precreasing and creasing disc elements, in particular the bottom disc elements, cooperating with top precreasing and counter-creasing disc elements.

[0051] The above disclosed device operates as hereinbelow disclosed.

[0052] More specifically, the adjustment of the distance of the counter-precreasing, counter-creasing and counter-slitting bottom discs, with respect to the top precreasing, creasing and driving belts, which operate in cooperation with the counter-slitting discs, must be performed depending on the variation of the paperboard material thickness.

[0053] In order to perform the above mentioned adjustment, it is necessary to open the solenoid valve 10, thereby clearing the hydraulic circuit, by clearing the pushing of the pistons of the jacks 6.

[0054] Then, upon having adjusted the novel required position of the main shafts 11, 12, 13 and 14, the oleodynamic pump 8 will reset, the solenoid valves 10 being opened, the pushing of the pistons of the jacks 6, by pressurizing the hydraulic circuit 7, to achieve a preset value on a pressure switch 9.

[0055] In this connection it should be pointed out that each piston of the hydraulic jacks 6 is controlled by a respective solenoid valve 10, which will be closed as the set and desired value is achieved.

[0056] Possible pressure drops, during the processing procedure, will be immediately compensated for by a momentaneous automatic switching on of the oleodynamic pump 8.

[0057] Figure 4 shows, on an enlarged scale, the sliding block assembly 30 supporting the supporting bar 1.

[0058] Figure 5 shows an enlarged detail, illustrating the bearing surface 5 of the supporting bar 1, the supporting bar 1 for the device for supporting the shafts 11, 12, 13 and 14, the tubes 7 for supplying the hydraulic jacks 6, the shafts 19 for driving the eccentric bushings supporting at their end portions the main shafts 11, 12, 13 and 14, the several hydraulic jacks 6, the bearing surface 5 for bearing the supporting bar 1, the guide elements 17, a linear guide 23 bearing the ball recirculating shoe 24 supporting the bar 1 bearing surface 5 for the shaft supporting device (supporting the shafts 11, 12, 13 and 14).

[0059] Figure 6 shows, on an enlarged scale, a detail of the operating machine and, more specifically, the linear guide 23 bearing shoe 24, the supporting bar 1 for the shafts 11, 12, 13 and 14 supporting device and the supporting bar 1 bearing surface.

[0060] From the above disclosure it should be apparent that the inventive device, to be applied to corrugated paperboard material processing machines, or other materials in sheet or strip forms, is perfectly suitable to prevent the main shafts of said machines from being bent.

[0061] The device according to the invention has been above disclosed and shown by way of a merely indicative but not limitative example of the features thereof.

[0062] Thus, it should be apparent that the disclosed device is susceptible to several modifications and variations, all of which will come within the scope of the invention.

Claims

1. A device to be applied to operating machine for processing corrugated paperboard material, or other materials in sheet or strip form, and designed for preventing main shafts from being bent, characterized in that said device comprises a supporting bar (1) for supporting a shaft supporting assembly, which supporting bar is longitudinally arranged with respect to the paperboard material feeding direction and is supported by cross-members (2) and (3) in turn applied, at the end portions thereof, to main shoulders of said machine, and being supported, at a central part thereof, by uprights (4) and further supporting elements bearing on the floor.

2. A device, according to claim 1, characterized in that said supporting bar (1) houses and supports, in turn, a plurality of hydraulic jacks (6), coupled through coupling tubes (7) for supplying a hydraulic fluid, to an oleodynamic pump (8).

3. A device, according to the preceding claims, characterized in that said oleodynamic pump (8) is coupled, through said tubes (7), to a solenoid valve (10) assembly, the solenoid valves of which are controlled by a pressure switch (9) adapted to adjust the pressure of the fluid for operating said plurality of jacks (6).

4. A device, according to one or more of the preceding claims, characterized in that said oleodynamic pump (8), pressure switch (9) and solenoid valve (10) assembly supply a fluid having a preset and constant pressure to said jacks (6), each of said jack operating supporting elements of each main shaft (11), (12), (13) and (14), thereby compensating for and eliminating flexure strains due to the weight of said shafts, which support said operating discs, and thereby preventing further strains caused by the paperboard material being processed during the precreasing, creasing and slitting and/or die-cutting operation steps.

5. A device, according to one or more of the preceding claims, characterized in that each said hydraulic jack (6) supports a bottom lug (15), preferably of curved configuration, rigid with a cradle (16), designed for providing a vertical movement, thereby it can be suitably raised and lowered.

6. A device, according to one or more of the preceding claims, characterized in that each said cradle (16) is laterally guided by a pair of guiding elements (17) and holding side plates (75).

7. A device, according to one or more of the preceding claims, characterized in that said guiding elements (17) and said side plates (75) and supporting bar (1) are bolted or coupled in any other suitable manner to one another, thereby providing a monolithic type of bearing construction, adapted to resist against stresses transmitted thereto by said main shafts (11), (12), (13) and (14), during the paperboard material processing steps.

8. A device, according to one or more of the preceding claims, characterized in that said shafts (19) drive eccentric bushes, adjusting the spacing of said disc supporting shafts, which respectively support counter-precreasing, counter-slitting, counter-creasing, creasing operating discs as well as associated operating belts arranged adjoining bottom slitting blades, depending on the thickness of the paperboard material to be processed.

9. A device, according to one or more of the preceding claims, characterized in that said device comprise a plurality of cradles (16), each of which supports, in turn, a bearing (20) which is held in a set position by side pairs of holding sectors (18).

10. A device, according to one or more of the preceding claims, characterized in that each said bearing (20) supports a said shaft (11), (12), (13) and (14) through a friction bush (22), adapted to provide an anti-seizing function, during the location or positioning movements.

11. A device, according to one or more of the preceding claims, characterized in that said device comprises moreover cross-members (2) and (3), which are preferably provided with linear guides (23) and sliding blocks (24), on which said supporting bar (1) is assembled to allow the overall system to be axially driven.

12. A device, according to one or more of the preceding claims, characterized in that said device is adapted to be axially driven by mechanical members driven by electric motors or oleodynamic pistons or manually adjusted systems.

13. A device, according to one or more of the preceding claims, characterized in that said main shafts (12) and (14) alternately support said precreasing and creasing discs, i.e. the bottom discs, cooperating with top counter-precreasing and counter-creasing discs.

14. A device, according to one or more of the preceding claims, characterized in that in said device an adjustment of the spacing of the counter-precreasing, counter-creasing, counter-slitting and counter die-cutting discs, arranged at a lower level than the precreasing discs, ceasing discs, die-cutting discs and top cooperating belts cooperating with the counter-slitting discs, is performed depending on a changing of the thickness of the paperboard material to be processed, and requires that said solenoid valves (10) are opened thereby discharging the hydraulic fluid from said hydraulic circuit, and switching off the pistons of the jacks (6).

15. A device, according to one or more of the preceding claims, characterized in that, after having adjusted the required position of said main shafts (11), (12), (13) and (14), the supply pump (8), with the solenoid valves (10) in an opened condition, recovers the operation or urging of the pistons of the jacks (6), by pressurizing said hydraulic circuit, so as to achieve a preset value on the pressure switch (9).

16. A device, according to one or more of the preceding claims, characterized in that each of said hydraulic jack (6) is controlled by a respective solenoid valve (10), which is closed as a desired and preset pressure value is achieved.

17. A device, according to one or more of the preceding claims, characterized in that in said device possible pressure drops, occurring during the operation of said device, are immediately compensated for by an automatic temporary switching on of said oleodynamic pump (8).

18. A device, according to one or more of the preceding claims, characterized in that said device comprises a plurality of constructional elements as suitably designed and mutually coordinated, and as broadly disclosed and illustrated in the preceding disclosure and in the figures of the drawings accompanying the present industrial invention Patent application.

Drawing