DE2949798A1 - IMPROVEMENTS TO THE MOVING BLADE OF THE FLYING SCISSORS CONTROLLER - Google Patents

Description

2S j798

dated December 11, 1979

F.I.M.I. Fabbrica Impianti Macchine Industriali S.p.Α., Vigano Brianza (Como), Italy

Improvements to the flying scissors moving blade controller

The present invention relates to improvements in the control device of the moving blade of flying scissors, in particular for automatic machines for cross-cutting sheet metal and the like, of the type on a fixed structure Unit for feeding the sheet metal includes, a flying shear, said with alternating movement in the feed direction Sheet metal for cutting the same into predetermined lengthwise parts, means for alternately adjusting said flying scissors and means for providing the lower blade of the scissors with an alternating movement perpendicular to the direction of advance of the sheet metal.

With a machine of the type mentioned above, one has a feed of the actual sheet at the same time and parallel to the sheet feed Cutting device consisting of an upper blade joined by a solid one connected to the body of said device Blade holder is carried and a lower blade, which is carried by a corresponding blade holder, the is also equipped with a vertical alternating movement. The cutting device goes cyclically after each sheet metal section back to the starting position without interrupting its movement.

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Of course, the sheet feed, the reciprocating motion of the cutter, and the vertical motion of the lower blade are perfectly synchronized to avoid the blades crossing each other and thus cutting through the sheet before the predetermined one Length is present.

In an operation that provides for the cutting of a certain number of sheet metal sections, the length of which thanks to a suitable equipment, which is located in the machine itself, it is necessary to use some sheet metal sections to be carried out with twice or three times the length of the predetermined length. To do this type of cut without the machine It is common to have to adjust the length to double or triple the length, while the sheet feed remains the same Known devices that operate the lower blade of the scissors and prevent them from reaching their maximum height, so that the cutter performs its to-and-fro movement, but without the blades cutting through the sheet metal.

An example of these devices has been described and claims were filed in a previous patent application for industrial inventions, deposit number 30639A / 75 in the name of the same applicant.

The control apparatus related to the above patent mainly consists from a first rotating shaft, which has a cylindrical cavity on both sides at the outer end, with a parallel axis and arranged eccentrically to the axis of rotation of the same shaft. Rotatably arranged within this cylindrical cavity a second rotary shaft is provided which has an eccentric pin at both outer ends. The first and the second shaft are kinematically connected to each other by a planetary reduction gear consisting of a Gear keyed onto the second shaft and one

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Solid and coaxial ring connected to the first shaft and internally toothed to mesh with the above-mentioned gear allow. A pair of connecting rods, the outer end of which falls into the aforementioned journals, connects the second shaft with the lower blade holder of the scissors to ensure a synchronous course between the sheet feed and the alternating movement of the flying scissors as well as the cutting operation of the blades.

In the above control unit it is also provided that the rim by external teeth, which in a toothed rail with back and forth Herlauf engages, the latter having a seat in the machine itself, running at an angle around its own axis. the Toothed rail with pneumatic or oleodynamic drive allows the ring to move angularly so that the lower blade follows its normal throwing line and swings without ever reaching the effective cutting height. To this Way, it is possible to let a sheet metal section pass by in double or triple length, with the toothed rail again is set if you want to get another cut.

However, a cutting device of this system also has inconveniences. It should be noted that the timing drive due to its intrinsic design, the tooth splint has too long a response time to the control signal in relation to the high speed achieved by the blades. Also, the length of time is difficult to determine, since these vary from one to the other Factors, such as the various compressibility of the operating media, which in turn depend on various external factors such as temperature, humidity and so on.

As a result, every time the toothed splint is operated, to cause the free cut, a dimensional error

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ORIGINAL INSPECTED

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for the effective subsequent cut.

Another inconvenience that this type of mechanism brings with it is given by the circumstances, how much time the answer on the part of the limit switches that actuate the control drive requires each time the cycle of the free cut is switched on.

The problem on which the present invention is based is to eliminate the inconveniences that have been criticized by realizing a moving blade control device that is independent of the sheet feed rate and which causes an immediate impression of the free cut, so that always and automatically an effective cut is achieved with high precision.

This problem is solved in conjunction with the present invention. Thanks to improvements to the control unit of the moving Blade of flying shears, especially for automatic machines for cross-cutting sheet metal and the like, characterized by the fact that it has both a first rotating hollow shaft, in which eccentric and im Idle a second shaft is present, which has at its outer ends a pair of pins coaxial with each other, exientrisch in relation to the axis of said second shaft, each pin being connected at one end to a connecting rod which other end of the rod, however, connected to a blade holder is carrying the said lower blade of the scissors.

Favorably and in agreement with a further characteristic of the present invention describes the axis said pin has a continuous, generally elliptical throw line and has a plurality vertical to the axis of loops, the number of which depends on the proportions of the

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ORIGINAL INSPECTED

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Depending on the gears of a reduction gear, which is located on a drive shaft, which has a toothed wheel includes corresponding further gear with which is mounted on the outside of said first hollow shaft.

The main advantage obtained with the present invention resides in the fact that it is not necessary to give the control outside to switch on the free cut or the effective cut, the latter always takes place and definitely through the machine design, each after one or more free cuts.

Another advantage is that the dimensions of the cut sheet metal piece are always largely repeated and precise, this both when cutting a piece with a predetermined length as well as when cutting a piece with a multiple Length. Further features and advantages of the invention in the subject will be better understood from the detailed description of a Implementation example of the preferred type, non-exclusive implementation form, of improvements to the Steut ^ device of the movable blade of flying scissors, described below with reference to the accompanying drawings, Data indicative but not limiting where:

- Figure 1 schematically shows a vertical cross section of a machine with flying shears for cross cutting represents of sheet metal, provided with the control device according to the invention;

Figure 2 shows a cross-section of the control unit, keeping line II-II of Figure 1;

- Figure 3 schematically shows a connection between the control unit and the reduction gear for introduction of the free section shows;

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- Figure 4 shows a side view of the control device;

- Figures 5, 6 and 7 show the throwing line of the axis of the Show output pins of the device according to the invention in relation to predetermined setting ratios on the reduction gear in Fig. 3.

With reference to the above figures and especially to the first illustration, 1 generally denotes a control unit, which is according to the invention and located in a frame 2 of an automatic machine for cross-cutting sheet metal and the like is located, which is globally referred to as 3. The automatic machine 3 contains a plurality of rollers 4, which are driven by associated motor units and thereby a sheet metal strip 5 as indicated by arrow A Advance Direction. With 5 a flying scissors was referred to, which is movable and is on associated side guides 7 move back and forth in the direction of the sheet metal strip feed 5, the scissors mainly from a upper blade 8, which is carried by an upper blade holder, and a lower blade 10, which is in a corresponding lower blade holder 11 is mounted.

The horizontal movement is input to the scissors 6 via a connection that is operated by a link mechanism, which is shown schematically under 13, and which in the cutting moment a synchronous run between the sheet metal strip feed 5 and back and forth movement of the flying scissors 6 produces.

With particular reference to Figure 2, the control device 1 includes an input shaft 14, which within a Ball bearing pairs 15 and 16, which are fixed in the frame 2, rotates. In the middle part of the shaft 14 there is a gear connection 17, which cooperates with a gear 18 which is mounted in the central part of a first hollow shaft 19

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INSPECTED - 7 -

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which rotates between respective ball bearings 20 and 21.

Inside the hollow shaft 19, a second shaft 22 is mounted eccentrically and idle, which is rotatable by ball bearings 23 and will be carried.

This second shaft 22 is provided at the outer ends with a pair of pins, which is indicated under 2 5 and 26 and under runs coaxially, but eccentrically in relation to the shaft axis 22. At each of the pins 2 5 and 26 is switched on Associated ball bearings 27 and 28, a head piece of a connecting rod, which is indicated with 29 for the pin 25 and with 30 for the pin 26 connected. The feet (not shown) of the connecting rods 29 and 30 connect the same at the top with the lower blade holder 11 of the scissors 6 (Figure 1). With particular reference to Figure 3, the input shaft 14 and the hollow shaft 19 are connected via associated cardan couplings 31 and 32 connected to the corresponding shafts 33 and 34 of a reduction gear generally designated 36.

The shaft 33 is driven by a motor shaft 36 on which a gear 37 is attached, which is connected to a gear 38, which is keyed onto the shaft 33, engages. At 39, 40 and 41 are splined gears on the shaft 33 referred to, the are intended to be used with corresponding keys wedged on the shaft 34, designated under the respective indications 42, 43, 44, to click into place.

Depending on the gears that mesh with each other, and thus according to the reduction ratios input to the reduction gear 35, describe the axes of the pin 2 5 and 26 a continuous throwing line (49, 50, 51), which compared to

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vertical axis symmetrically has a plurality of loops. In particular, when the gear 39 meshes with the gear 42, the throw line (49) described is that of Figure 5; when the gear 40 meshes with the gear 43, the throw line (50) is that of Figure 6 and finally when the gear 41 engages in gear 44, the throw line (51) described is the one shown in Figure 7.

Reaching the above throw lines is determined on the one hand by the eccentricity of the journals 2 5 and 26 in relation to the second shaft 22 and the latter in relation to the hollow shaft 19, and on the other hand from the fact that the second shaft 22 is mounted on the hollow shaft 19 in idle mode.

In fact, the rotation of the second shaft 22 makes the axis of the eccentric pins 25 and 26 cylindrical Can run surface around the axis of the same shaft 22, as indicated by the dotted circle 4 5 in Figure 4. In an analogous manner, the rotation of the hollow shaft 19 makes that the axis of the second shaft 2 has a cylindrical surface around the The axis of the hollow shaft 19 can be described, as indicated by the circle 46 with the dotted line in Figure 4.

During the operation of the flying shears, the hollow shaft 19, which is moved by the shaft 14, pulls the second shaft 22 in Rotation according to dotted circle 46, while the rotation of the second shaft 22 about its own axis only by effect the connection between the eccentric pins 25 and 26 and the lower blade holder is created with a back and forth movement, which is achieved by the connecting rods 29 and 39. This justifies the appearance of a large number of loops 47, which are described by the throwing line of the axes of the eccentric pins 25 and 26.

With a moving blade control device designed in this way, the multiplicity of

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Length of the sheet metal sections an independent cutting activity of the advance of the sheet, which is in an apparatus 48 in the Near the link mechanism 13 (Figure 1) is housed. So if you want to multiply the length of the sections, it is sufficient to actuate the reduction gear 35, the coupling of the meshing gears being reversed.

The machine 3 is operated according to the following method. At the beginning there is a certain feed rate set for the sheet metal strip 5 and a certain feed speed of the scissors. This shows up in this way the reduction gear 35 with the mutually engaging gears 39 and 42. The sheet metal strip 5 runs forward while the scissors 6 perform an effective cut of the sheet metal with each forward and backward run. The corresponding The throw line described by the axes of the eccentric pins 2 5 and 26 is the one in Figure 5.

If the double length of the sheet metal sections is to be produced without operating the apparatus 48, it is sufficient to do this To operate reduction gear 3 5, so that the engagement of the gear 40 with the gear 43 takes place. Accordingly the scissors 6 must, before arriving at the effective cut of the sheet, perform two reciprocating movements, during one of which Turns the lower blade 10 reaches a maximum height without using the upper blade 8.

This condition corresponds to the free cut, and the corresponding one The throw line of the axes of the eccentric pins 25 and 26 can be seen in Figure 6.

If, on the other hand, sheet metal sections with three times the length are to arise, the reduction gear 35 must engage the Gear 41 can be entered with the gear 44. In this case, the flying scissors 6 must go back and forth three times

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carry out; during the first two, the lower blade 10 reaches a maximum height without interfering with the upper blade 8 to be used, while the effective cut is only made on the third run.

Of course, numerous structural variants of the control device for the movable blade of flying Scissors can be implemented in connection with the present invention without therefore falling outside the scope of protection step.

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Original. INSPECTED

Claims (3)

Claims "\ y Improvements to the control device of the movable blade of the flying shears for automatic machines for cross-cutting sheet metal and the like of the type including a fixed frame (2), a unit (3) for sheet feed, a flying shear (6), provided with alternative movement in Feed direction of said sheet (5) for cutting the same into predetermined lengthwise pieces, means for alternately adjusting said flying scissors and means for giving an alternating movement to the lower blade (10) of the scissors perpendicular to the feed direction of the blade (5), this characterized by the fact that a first hollow rotary shaft (19) is provided, in which a second shaft (22) is mounted eccentrically and in idle mode, which is provided at the outer ends with a pair of mutually coaxial pins which are eccentric to the axis of said second shaft ( 22), each of which sits in the connecting rod head (29,30), the foot of which is attached to a blade holder ung (11) carrying said lower blade (10) of the scissors. 2. Improvements according to claim 1, characterized by the fact that the axis of said pin (29, 30) a continuous, on the whole elliptical throw line executes (49, 50, 51), whereby they are symmetrical in relation has a number of loops (47) to a vertical axis, the number of which in turn depends on the ratios of the - 12 - 030032/0 5 37 ORIGINAL INSPECTED 2SU0798 Gear wheels of a reduction gear (35) which is connected to a drive shaft (14), which by means of a gear (17) includes a corresponding further gear (18) which is externally connected to said first hollow shaft (19) is raised. 3. Improvements according to the preceding claims, characterized by the fact that the cutting movement regardless of the multiplication of the feed lengths of the sheet, which is stacked in a corresponding apparatus, takes place. 030032/0537 ORIGINAL INSPECTED