CN111406120B

CN111406120B - Improved staking machine

Info

Publication number: CN111406120B
Application number: CN201880076035.XA
Authority: CN
Inventors: 安东尼奥·波拉托
Original assignee: Cartiglino Orpheine
Current assignee: Cartiglino Orpheine
Priority date: 2017-11-30
Filing date: 2018-11-30
Publication date: 2023-06-20
Anticipated expiration: 2038-11-30
Also published as: HRP20211764T8; EP3717668A1; ES2898318T3; RS62684B1; PL3717668T3; MX2020005578A; WO2019106616A1; KR20200094159A; PT3717668T; HRP20211764T1; EP3717668B1; CN111406120A

Abstract

An improved staking machine (1) for softening and stretching flexible sheet products such as industrial hides having opposite sides, comprises a motorized feeding device (5) for conveying the products in a predetermined longitudinal direction (L), at least one pair of striking plates (10, 10') facing each other, substantially parallel to the feeding device (5) and acting on opposite sides of the products. One plate (10) is fixed and the other (10') is movable and connected to motor means (11) which transmit to it a reciprocating motion with a predetermined number of strokes per minute. The machine (1) comprises means (23) for adjusting the operating pressure between the fixed plate (10) and the movable plate (10 '), which selectively act on the fixed plate (10) to vary the reciprocal distance between the fixed plate (10) and the movable plate (10'). The machine (1) also comprises electronic control means (24) acting on the motor means (11) to continuously vary the number of strokes per minute of reciprocation of the movable plate (10') during initial start-up and steady-state operations, depending on the type of product to be treated and on the characteristics of the desired product.

Description

Improved staking machine

Technical Field

The present invention finds application in the field of leather making equipment in general, and relates in particular to an improved staking machine for flexible sheet products.

Background

Machines known for a long time as staking machines are used in tanneries for softening and stretching flexible sheet products, such as industrial hides and similar products having opposite sides (i.e., grain and meat sides).

These machines are used in the steps after tanning and/or drying to restore the original softness of the leather and to increase its size, i.e. the useful leather area.

Typically, these machines comprise motorized feeding devices for feeding the product in a predetermined direction, for example consisting of a pair of mutually facing conveyor belts, between which the sheet product to be softened is inserted.

These machines also comprise one or more pairs of striking plates facing each other, parallel to the longitudinal direction. The plates reciprocate to move toward and away from each other substantially perpendicular to the product feed plane.

In addition, each plate has a tool or peg adapted to interact with a corresponding mating shaped cavity or recess on the opposite plate.

EP2049694, by the owner of the present invention, discloses a shoveling machine comprising at least one fixed plate and a movable plate associated with means for adjusting the mutual distance between the two plates.

These adjusting means can adjust the stretching pressure of the opposite sides of the pelt and thus the finishing of the product.

While the machine may perform its intended tasks satisfactorily, it is still improved, i.e., from the standpoint of improving the efficiency and productivity of the machine.

The useful leather area and softness of the flexible sheet product is directly dependent on the feed speed through the machine and the number of hits per minute of the striking plate.

Nevertheless, the feed rate of the product can be adjusted within a limited range, which is directly related to the feed rate of the product in the production line and is proportional to the production rate.

To at least partially eliminate this drawback, machines have been developed that can adjust the number of impacts per minute of reciprocating movement of the movable plate.

The number of hits is typically varied by adjusting the speed ratio between the motor and the drive shaft that imparts motion to the movable plate.

Nevertheless, due to the considerable mass of the striking plate, this adjustment can only be done discretely and with the machine shut down, which increases the processing time and reduces the working coefficient.

An additional disadvantage of this arrangement is that it requires manual adjustment by the operator, which increases the complexity and labor intensity of the adjustment step.

Another disadvantage of this arrangement is that in order to adjust the speed ratio, the operator must manually access the mechanical moving parts, which are typically arranged in difficult to access positions below the feeding device.

EP0829543 and CN104746352 disclose a staking machine for softening and stretching flexible sheet products as defined in the preamble of claim 1.

Technical problem

In view of the prior art, the technical problem addressed by the present invention is to provide a staking machine that enables a more efficient and immediate adjustment of the number of hits to adapt the machine in time to the various types of products to be treated and the characteristics of the desired products.

Disclosure of Invention

The object of the present invention is to eliminate the above-mentioned drawbacks by providing an improved staking machine for softening and stretching flexible sheet products, which is efficient and relatively cost-effective.

It is a particular object of the present invention to provide an improved staking machine as described above that is capable of continuously adjusting the number of hits per minute for one or more movable panels.

It is a further object of the present invention to provide an improved staking machine as described above which is capable of reducing power consumption at start-up.

It is a further object of the present invention to provide an improved staking machine as described above which is capable of significantly reducing the overall flexible sheet product processing time.

Another object of the present invention is to provide a machine as described above which is capable of easily reducing the number of strikes of the plate in a wide adjustment range.

A further object of the present invention is to provide a machine as described above which is highly flexible and allows to adjust the number of hits according to the feeding speed of the sheet product.

These and other objects, as will be more clearly illustrated hereinafter, are achieved by an improved staking machine for softening and stretching flexible sheet products, such as industrial hides and the like, having opposite sides, comprising a motorized feeding device for conveying the products in a predetermined longitudinal direction, at least one pair of striking plates facing each other, substantially parallel to the feeding device and acting on opposite sides of the products, one of the plates being fixed and the other plate being movable.

The machine further comprises: a motor means associated with the movable plate in each pair to transmit to the movable plate a reciprocating motion having a predetermined number of impacts per minute; and means for adjusting the operating pressure between the fixed plate and the movable plate, the means selectively acting on the fixed plate to vary the mutual distance between the fixed plate and the movable plate.

In a unique aspect of the invention, the machine includes an electronic control device that acts on the motor means to continuously vary the number of strokes per minute of reciprocation of the movable plate during initial start-up and during steady state operation, depending on the type of product to be treated and the characteristics of the desired product.

Advantageous embodiments of the invention are obtained according to the dependent claims.

Drawings

Further features and advantages of the invention will become more apparent upon reading the detailed description of a preferred, non-exclusive embodiment of an improved staking machine for softening and stretching flexible sheet products, described as a non-limiting example with the aid of the accompanying drawings, in which:

FIG. 1 is a perspective view of a staking machine of the present invention;

FIG. 2 is a side view of the machine of FIG. 1;

FIGS. 3 and 4 are cut-away side views of the machine of FIG. 1;

FIG. 5 is a cut-away top view of the machine of FIG. 1, showing a drive system;

fig. 6 and 7 are first and second block diagrams of control of the machine of fig. 1.

Detailed Description

Referring to the foregoing drawings, there is shown an improved staking machine, generally designated by the reference numeral 1, for softening and stretching a flexible sheet product (not shown) such as industrial hides, having opposite sides.

The staking machine 1 comprises a load-bearing structure 2 adapted to define an inlet region 3 and an outlet region 4 for sheet products and a motorized feeding device 5 for conveying sheet products in a predetermined longitudinal direction L from the inlet region 3 to the outlet region 4.

As known per se, the feeding device 5 may comprise a pair of endless upper and lower conveyor belts 6, 7 tensioned by at least one pair of end rollers 8, 8', 9'.

The pair of conveyor belts 6, 7 may have respective substantially straight and horizontal portions 6', 7' facing each other to hold the sheet product introduced into the inlet region 3 of the machine 1 and feed it towards the outlet region 4.

The machine 1 also comprises at least one pair of striking plates 10, 10' facing each other, substantially parallel to the feeding means 5 and acting on opposite sides of the product being processed.

The upper plate 10 is fixed and the lower plate 10' is movable and connected to the motor means 11. The motor means 11 transmits reciprocating motion to the movable plate 10' to move the movable plate toward or away from the fixed plate 10 at a predetermined number of strikes per minute.

The fixed upper plate 10 may include a plurality of peg tools (not shown) and the movable lower plate 10' may include a plurality of mating shaped cavities or holes (also not shown) aligned with the pegs.

During the striking, the plates 10, 10' interact due to the pegs and holes to exert a predetermined pressure on the sheet product as it is fed.

It is clear that the tools may also be different or have a different arrangement, i.e. the holes are formed in the fixed plate 10 and the pegs are formed in the movable plate 10', without departing from the scope of the invention.

Advantageously, a plurality of

plates

10, 10', 10 "and 12, 12', 12" can also be provided in the longitudinal direction L of the sheet product, which act on the conveyor belts 6, 7 on the straight portions 6', 7' of the conveyor belts 6, 7 described above.

For example, in the contemplated and non-limiting embodiment of the drawings, two sets of

plates

10A, 12A may be provided, including a pair of fixed

upper plates

10, 10 "and a movable lower plate 10 'and a pair of fixed

upper plates

12, 12" and a movable lower plate 12', respectively, that are fixed to the load bearing structure 2.

As best shown in fig. 5, the motor arrangement 11 preferably comprises a first electric motor 13, preferably a three-phase asynchronous motor, connected to the movable plate 10', 12' via a drive mechanism 14 and a crank and

link system

15, 16 or the like.

That is, the movable lower plates 10', 12' are mounted onto the upper end 17 of the connecting rod 15, the upper end 17 of the connecting rod 15 in turn being moved by a respective crank 16, which crank 16 is coupled to the shaft 18 of the motor 13 via the drive mechanism 14.

As is known per se, the drive mechanism 14 may comprise one or more drive belts 19, and the crank 16 may have a circular cam.

In the embodiment shown, the second set of plates 12A also includes a crank and connecting rod system 15', 16'.

The latter is coupled to the cranks 16 of the first set of plates 10A via a further driving mechanism 20, which further driving mechanism 20 is preferably constituted by a toothed conveyor belt 21.

Thus, the second set of plates 12a is driven relative to the first set 10A and its reciprocating motion is synchronized with the reciprocating motion of the

plates

10, 10', 10 "of the first set 10A.

Suitably, at least one second, independent three-phase asynchronous electric motor 22 may be provided, independent of the first motor 13, and this second three-phase asynchronous electric motor 22 is coupled to at least one of the rollers 8, 9 for moving the conveyor belts 6, 7.

As shown in fig. 2, the machine 1 further comprises means 23 for adjusting the working pressure between the fixed plate and the movable plate. The adjustment means 23 act on the

fixed plates

10, 12 and change their distance from the movable plates 10', 12'.

The adjustment means 23 may be of a known type, for example of the type described and illustrated in european patent EP2049694 of the owner of the present invention.

In a unique aspect of the invention, the machine 1 comprises an electronic control device 24 which acts on the motor means 11 of the striking plate 10, 10' to continuously vary the number of strikes per minute of reciprocating movement of the movable plate 10' or of the movable plate 12'.

In particular, the control device 24 may vary the number of hits during initial start-up and steady-state operation depending on the type of product to be processed and the characteristics of the desired product.

The control device 24 may comprise a PLC control unit 25 operatively connected to a first inverter 26 adapted to power the first three-phase asynchronous motor 13.

Advantageously, the control device 24 may comprise a second inverter 27 operatively connected to the PLC control unit 25 and adapted to control the operation of the second electric motor 22 of the feeding device 5.

Accordingly, the rotation speed of the second electric motor 22 and the corresponding feeding speed of the conveyor belts 6, 7 can be changed according to the characteristics of the desired product in combination with the striking number of the movable plates 10', 12'.

In addition, the control device 24 is able to make independent and continuous adjustments to the

impact mass

10, 10', 10 "and 12, 12', 12" and to the feeding device 5 without a step change in speed, to effectively provide a softened and stretched sheet product or to change its productivity without shutting down the machine 1.

A control algorithm 28 may be installed in the PLC control unit 25, and the PLC control unit 25 may be programmed to control the first inverter 26 such that the first electric motor 13 is operated at a constant flow by a torque equal to the maximum torque during the start-up of the first electric motor 13.

That is, for frequency values less than the nominal value of the mains frequency (equal to 50 Hz), a constant flow of the first motor 13 during start-up is regulated by the first inverter 26.

Accordingly, the first motor 13 may operate with an acceleration ramp (acceleration ramp) s having a predetermined duration during which the first inverter 26 provides a time-modulated voltage and frequency to the first motor 13.

With this configuration, the power consumption of the machine 1 during start-up can be reduced, and a motor with a lower rated power can be used.

Accordingly, the first motor 13 can be appropriately sized for steady-state operation and no special sizing for starting is necessary, and a smaller magneto-caloric switch can be installed because the current peak is reduced.

Further, the PLC control unit 25 and the first inverter 26 may be configured to allow selection of the number of strikes of the movable plate 10' or the movable plates 10', 12' in the range of 200 to 900 strikes/minute, preferably 250 to 800 strikes/minute.

Advantageously, a sensor device 29 may be associated with the driving mechanism 14 to detect the actual number of strikes of the movable plate 10' or the movable plates 10', 12' and to transmit a corresponding electrical signal E to the PLC control unit 25.

The sensor means 29 are adapted to detect the rotation of the mechanism 14 and to generate a corresponding electrical signal E and may comprise, for example, an optical or mechanical encoder or other similar sensor.

The control means 24 may comprise interface means 30 which may be accessed by an operator to set a desired number of strikes, and the control unit 25 may be programmed to continuously compare the desired number of strikes B with the electrical signal E, possibly filtered by a suitable software filter F, using an installed algorithm 28.

Further, the PLC control unit 25 is configured to transmit a corresponding control signal C to the first inverter 26 controlling the operation of the first motor 13, thereby reducing current absorption during start-up.

Suitably, the staking machine 1 may comprise a switchboard 31, the switchboard 31 being adapted to receive power from the mains N and being operatively connected to the PLC control unit 25. The PLC control unit 25 may communicate with the interface device 30, the sensor device 29, the first inverter 26, and the second inverter 27 via cables to transmit the signal 32 using a MODBUS communication protocol or the like.

The closed-loop control scheme using the sensor 29 is shown in the block diagram of fig. 6, while the block diagram of fig. 7 shows the control by the algorithm 28 of the control unit 25.

From the foregoing, it will be appreciated that an improved staking machine achieves the intended aim and in particular enables more efficient and immediate adjustment of the number of hits and makes the machine easy to adapt to the various types of products to be treated and the characteristics of the desired products.

The staking machine of the present invention is capable of numerous changes and modifications within the inventive concept disclosed in the appended claims.

Although the machine has been described with particular reference to the accompanying drawings, the reference numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.

INDUSTRIAL APPLICABILITY

The invention can find industrial application in that it can be produced on an industrial scale in leather and pelt processing plants.

Claims

1. An improved staking machine (1) for softening and stretching a flexible sheet product having opposite sides, the staking machine (1) comprising:

-motorized feeding means (5) for feeding said product in a predetermined longitudinal direction (L);

-at least one pair of striking plates facing each other, substantially parallel to said feeding means (5) and acting on opposite sides of the product, one striking plate being a fixed plate (10) and the other striking plate being a movable plate (10');

-motor means (11) associated with said movable plate (10 ') to transmit to said movable plate (10') a reciprocating motion with a predetermined number of impacts per minute;

-means (23) for adjusting the working pressure between said fixed plate (10) and said movable plate (10 '), said means selectively acting on said fixed plate (10) to vary the reciprocal distance between said fixed plate (10) and said movable plate (10');

wherein the motor means (11) comprise at least one first electric motor (13) connected to the movable plate (10') via a drive mechanism (14) and a crank and link system (15, 16),

characterized in that said at least one first electric motor (13) is a three-phase asynchronous electric motor, said staking machine being provided with:

-an electronic control device (24), the electronic control device (24) comprising a PLC control unit (25) operatively connected to a first inverter (26) suitable for powering the first electric motor (13), the PLC control unit being configured to act on the motor device (11) to continuously vary the number of strokes per minute of reciprocation of the movable plate (10') during initial start-up and during steady-state operation, depending on the type of product to be treated and on the characteristics of the desired product;

-sensor means (29) associated with said driving mechanism (14) to detect the actual number of strikes of said movable plate (10') and to transmit an electric signal (E) to said PLC control unit (25) correspondingly, said PLC control unit (25) being programmed to continuously compare the desired number of strikes (B) with said electric signal (E) filtered by a suitable algorithm (28) and to send a control signal (C) to said first inverter (26) to reduce current absorption during start-up.

2. The improved staking machine of claim 1 wherein the PLC control unit (25) and the first inverter (26) are configured to allow selection of the number of strikes of the movable plate (10') in the range of 200 strikes/minute to 900 strikes/minute.

3. The improved staking machine of claim 2 wherein the PLC control unit (25) and the first inverter (26) are configured to allow selection of the number of strikes of the movable plate (10') in the range of 250 to 800 strikes/minute.

4. The improved staking machine of claim 1 wherein the PLC control unit (25) is programmed to control the first inverter (26) to operate at a constant flow with a torque equal to maximum torque during start-up of the first electric motor (13).

5. The improved staking machine of claim 1 wherein the PLC control unit (25) includes an interface device (30) designed to be accessed by an operator to set a desired number of blows (B).

6. The improved staking machine as claimed in claim 1, wherein the feed means (5) comprises an endless upper belt conveyor (6) and an endless lower belt conveyor (7), wherein the upper belt conveyor (6) is tensioned by a first end roller (8) and a second end (8 ') roller, the lower belt conveyor (7) is tensioned by a third end roller (9) and a fourth end roller (9'), at least one of the first end roller (8) and the third end roller (9) being coupled to at least one second three-phase asynchronous electric motor (22) which is independent of the first electric motor (13).

7. The improved staking machine of claim 6 wherein the electronic control means (24) includes a second inverter (27) operatively connected to the PLC control unit (25) and adapted to control the operation of the second three-phase asynchronous electric motor (22) to continuously vary the rotational speed of the second three-phase asynchronous electric motor and to vary the feed speed of the upper and lower belt conveyors (6, 7) accordingly, depending on the characteristics of the desired product.

8. The improved staking machine of claim 1 wherein the flexible sheet product is industrial rawhide.