DE3320613C2 - Method for cutting off a web that carries records, as is used in printers or office machines, and device for carrying out the method - Google Patents

Abstract

The invention relates to a method for cutting off a web, as used in printers or office machines, with a shearing device with a drive and a shearing knife, which is rotated by a predetermined angle to cut the web, stroking along the cutting edge with a stationary blade and then returns to the starting position. The drive of the shear device is used during the minimum printing and / or transport time for a print line to store the essentially evenly released energy in a spring drive for the shear knife via a translation, which stops the drive after reaching a predetermined restoring force and after receiving a trigger signal the cutter suddenly moves against the blade and after the end of the cutting process the cutter again abruptly resets and then the build-up of the restoring force within the spring drive begins again up to and including the shutdown of the drive.

Description

a) the spring (49) of the spring drive is with one end on the tensioning lever (19) and with the other End hinged to a further lever (31) which is also rotatable about an axis of rotation (32) is mounted, the tensioning lever (19) through the cam (14) after tensioning the The spring (49) is blocked after the end of the shearing process,

h) the lever (31) or the axis of rotation (32) of the same are with the movable cutter (58) in operative connection,

c) the spring drive also has a releasable lock (38,40,46,56), which with the Lever (31) interacts and this with the beginning of the tensioning of the spring (49) is locked and releases for knife cut,

d) the lever (31) engages another spring (50), which after releasing the tensioning lever (19) and after the end of the shearing process, the clamping lever and the lever in theirs at the same time Postpones starting positions,

e) in the way of the clamping lever (19) or the cam disc (14) a pulse generator (photo reflex light barrier 51) is built in, which when driven over emits a stop pulse for the drive.

3. Device according to claim 2, characterized in that that the drive has a gear (12) which is firmly connected to the cam (14) is. whose runway (17) is an involute. in the a straight stretch of path (67) ends at which s :: h in At an acute angle (alpha), another straight stretch of path (68) connects to the beginning (55) of the roll-off track (17)

4. Apparatus according to claim 2, characterized in that that the clamping lever (19) is curved in an S-shape and about in the middle laterally has rotatably arranged wheel (18) which rolls on the rolling tracks (17,67).

5. Device according to claims 2, 3 and 4, characterized in that the locking of the Lever (31) consists of an arm (40) which is spring-loaded is supported pivotably about one end and which has a recess (46) at its free end, in which a retaining pin (38) arranged on the lever (31) engages and the arm by means of an on Gear (12) arranged pin (56) is pivotable to release the retaining pin from the recess.

6. Device according to one of the preceding claims, characterized in that the shearing knife (58) and the stationary blade (64) parallel to the platen (65) of the printer (57) in close proximity of the print head (6) are arranged.

7. Device according to one of claims 2, 5 or 6, characterized in that the pulse generator is a photo refiex light barrier (51)

The invention is based on a method for Cutting off a record-bearing web, as used in printers or office clusters takes place according to the preamble of claim 1.

DE-GM 74 08 722 discloses a device for cutting a recording medium such as paper become known, with a device for guiding the medium through the cutting device, a with a cutting edge provided rotary knife and with a cooperating with it, also with a A stationary knife provided with a cutting edge, the rotary knife having an actuating device which a cam disk and a transmission device actuated by this has, which is connected to the rotary knife.

DE-AS 11 97 907 a device for cross-cutting is used in a typewriter Paper web became known, which on a guide rail a displaceable knife carrier with a Has knife. The guide rail of the knife carriage has one in the ready-to-cut position tensioned energy storage spring acting on the knife carriage, the knife carriage in the ready-to-cut position is held by a releasable latch.

Furthermore, through EP-A 00 17 014 cm dot matrix printer has become known with a cutting device, in which the knife blade of the cutting device for the printed paper is the curve carrier of a flat thrust curve gctricbcs. on its curve a

ne roller mounted on the needle head is running

From DE-OS 26 22 302 a pulling and separating device for documents has also become known, in which a shaft of a separating roller is connected to an energy-storing device is that immediately after the end of the feed movement the separation roller against the feed movement to clear the conveyor gap from drives possibly too many withdrawn documents according to the respective stored energy

DE-OS 32 35 977 also provides a device for feeding single sheets from one Magazine for writing honeycomb of an office machine became known, in which the Antriebser.ergie of Device is delivered from the platen. In order to reduce the peak values of the energy demand, is an energy store is provided which can be charged by the drive energy supplied by the platen and during the phases of the separation and supply process with maximum energy requirement the stored Releases energy to the device. A cam is provided for this, with a Follower lever is under the tension of a tension spring tense, while the stored energy is used again as drive energy via a steeply sloping part of the curve is delivered to the cam.

The known cutting devices have the disadvantage that they cause sudden movement of the Shear blades require a lot of energy because the drive of the shear blade must be designed so that it within the cutting time, which lasts only a few milliseconds, the necessary for the sudden movement Must provide energy. The drive is therefore loaded at intervals, and energy is also generated destroyed by the braking process This results in a high energy consumption for the cutting process, which is why the drive motor for the cutting knife must be designed accordingly. The device DE-OS 32 35 977 is not applicable to a cutting device, because in this device for feeding only one energy peak is compensated by single leaves is, but fights on a moving part, the entire maximum energy can be released at the same time can.

The invention is therefore based on the object of creating a method of the type according to the invention, with which the power of the drive of the shearing device is minimized and which can cut the web into constant or any sheet sizes at very short intervals; ^r be ichtufig particular kitfin grown mechanically simple and, to integrate, for example, in a printer.

The solution of the problem consists in the features of PatentUnsbructH 1. A device for performing the method erfintlung ^s invention lies in the features of the Pa ^l enanspruchs2. Further advantageous embodiments of the device according to the invention are identified in sub-paragraphs 3 to 7.

The process according to the invention has due the separation of the cutter drive, the one spring is, from the main drive, which is an electric motor, the advantage that the electric motor can be made small. Because the electric motor only needs the tension necessary for the tensioner, the spring within the minimum pressure and / or spend transport time for a print line over a translation, this time compared to the time of the cutting process is greater by a factor of approximately 500 to deliver the energy of the electric motor and to build up the restoring force within the drive spring the electric motor can be designed for the lowest possible energy output for the cutting blade, because only the product time χ torque is important. This has the further advantage that the electric motor delivers practically an even torque and is therefore evenly loaded. In thus advantageously the addition of two forms of energy in different time scales is present here, namely the practically uniform drive power for transporting the paper within the printing device combined with the extremely high energy for driving the shear blade, these two energies are superimposed.

The method according to the invention thus advantageously provides a cutting device with two Drives are available, of which "a drive, the drive for the clamping lever, a low power or a low torque and the other drive for the cutting knife, which is a spring drive, a high one Power or a high torque or a high impulse for the shear blade.

Due to the use of an involute as a rolling curve, the spring also acts as a drive the shear blade is evenly tensioned so that the electric motor only delivers an even torque got to.

Due to the indirect drive of the cutting blade via the spring, a high cutting speed can be achieved, at least one cut per second. Because the actual cutting process takes just a few Is carried out milliseconds, the paper transport does not need to be interrupted, but the paper can be conveyed continuously through the cutting device.

Furthermore, due to its construction, the device is very small and can advantageously be easily integrated into printers or other office machines, not least because the necessary electric motor can be designed to be small.
An example of the invention is shown in the drawing and described below. It shows

F i g. 1 is a perspective exploded view of the device,

F i g. 2 the device of FIG. 1 in assembled State integrated with a printer,

F i g. 3 shows a schematic section through the roller and the print head to illustrate the position of the two shear blades acting against one another
F i &. >'<the cam in detail.
Fig. 1 shows an exploded perspective drawing of the device, the two cutting blades not being shown for the sake of simplicity.

The device consists of two side plates 1, 2, which are supported by roller-shaped spacers 3, 4, 5 and 6 are kept at a distance from each other and between which the other parts of the mechanism are arranged. The spacers 3, 4, 5 and 6 have plug-in teeth 7, 8 on, the in associated holes 9,10 of the side plates 1, 2 are firmly inserted. The dotted lines 11 each indicate the fitting direction of the corresponding part to the side panels.

The mechanism consists of a gear train 12, which has an electric motor 69 and a not drive gear shown is driven. The tooth-

wheel 12 is suitably mounted within a bearing 13 of the side plate 1, this bearing 13 preferably being arranged niittig within the side plate. The gear wheel 12 is firmly connected to a cam disk 14 which has a laterally protruding bearing pin 15 ^r , which is suitably supported within a bearing 16 in the side plate 2; this bearing 16 is again preferably arranged centrally within the side plate 2. The cam disk 14 has a rolling track 17, the cam disk and its function being described in more detail below in the description of FIG.

A clamping lever 19, preferably of S-shaped curved is, at its lower end by means of pivot pin 20 is rotatably mounted in bearings 21,22 of plates 1,2 in the side \ ^r> and has approximately at its center a laterally arranged wheel 18, which is preferably ball-bearing, which rolls on the Abruliuähn i7 of the cam disk 14 and in the rest position of the device lies at the beginning 55 of the rolling track 17. In the area of the upper end of the tensioning lever 19, a counter-bracket 24 is attached to the inside of the side plate 2, which for this purpose preferably has a pin which is inserted into a hole 25 in the side plate 2. The clamping lever 19 is supported against this counter-support with an inclined end face 23 in the rest position. The tensioning lever 19 also has two laterally arranged axles 26, 27. which are angeorü et opposite the wheel 18 and which are used to link springs 49, 50. The side plate 2 has three curved slots 28, 29, 30, the axes 26 and 27 projecting through the slots 28 and 30, respectively.

Another lever 31, which is preferably designed as a twin lever with two parallel arms 35,36 is. has a transversely continuous axis of rotation 32 at its lower end and is firmly connected to it. The axis of rotation is supported at both ends in bearings 33,34 of the side plates 2 and 1, with one end of the axis of rotation, which protrudes through the bearing 34 of the side plate 1, at the same time the drive axis of rotation for the Shear knife 58 (Figs. 2 and 3). The lever 31 is thus pivotably mounted about its axis of rotation 32, what in Fig. 1 indicated for the corresponding parts by a curved arrow or double arrow is.

One arm 36 of the lever 31 has a laterally protruding axis 37. through the curved Slit 29 protrudes. The other arm 35 has a laterally protruding opposite to the axis 37 directed retaining pin 38. whose function will be described later.

The clamping lever 19 and the lever 31 are thus arranged with their axes of rotation 20 and 32 adjacent such that the axes 26, 27 and 37 protrude through the slots 28, 29, 30 of the side plate 2. 5s The slots 29, 30 are arranged approximately on the diagonal of the side plate 2, the slot 29 from the upper corner to just above the center of the slot 30 from above the center to the lower, diagonally lying corner is enough; the slot 28 extends approximately to the left of the center of the side plate 2 until shortly above the lower side edge below the bearing 16.

A spring 49 is with one end laterally outside the side plate 2 on the protruding end of the axle 27 of the clamping lever 19 and hinged at the other end to the protruding axis 37 of the lever 31. Another spring 50 is attached at one end to a retaining pin 48, which is fixed to the outside on the side Side plate 2 is mounted. The other end of the spring 50 is on the projecting axis 26 of the tensioning lever 19 attached.

To lock the lever 31, the device has a sword-shaped arm 40 which; in a The end is rotatably supported on a shaft 39. the side shaft journal 41, which in turn in bearings 42,43 the side plates 2 and 1 are suitably supported. the Shaft 39 is adjacent to a corner of the side plates 1, 2, below the shaft 39 is the spacer 6 arranged. In the vicinity of the free end of the arm 40, a pin 44 is arranged on its rope. A coiled spiral spring 45, which preferably loops around the shaft 39 once, is supported with an F.ndc against the spacer 6, with the other end against the pin 44. In this way, the arm 40 becomes by the spiral spring 45 in the in F i g. 1 position shown rotated counterclockwise. The ann 40 also has a recess 46 at its free end on, which is used to plant the Haltcstiftes 38 of the lever 31. In this way, the lever 31 is through the arm 40 locked, which is pressed by the force of the spiral spring 45 downwards. Furthermore, the underside of the Arm 40 designed with an inclined plane 47 which ends in a mushroom 53 to which a further recess 52 df "· arm 40 connects, the boundary of this recess 52 being approximately perpendicular.

The gear 12 has in the vicinity of its periphery on a laterally protruding pin 56, which with the inclined plane 47 of the arm 40 cooperates and comes to rest in the recess 52 in the rest position, what in Fig. 1 is indicated by dotted lines.

The function and the sequence of movements of the device are as follows:

The electric motor 69 drives the gear via its drive shaft and a gear reduction (not shown) 12 and turn it clockwise. As a result, the pin 56 moves from its rest position within the Recess 52 of the arm 40 out. At the same time, the cam 14 rotates clockwise, whereby the wheel 18 rolls along the rolling track 17 and the tensioning lever 19 is also moved clockwise. As a result, the two springs 49, 50 are fastened to the arms 27, 26 and 37 or to the retaining pin 48 are pulled apart, whereby a restoring force corresponding to the spring constantc is stored in them will. The retaining pin 38 of the lever 31 engages in the recess 46 of the arm 40, whereby the twin nebulae 31 is blocked

When the wheel 18 of the tensioning lever 19 has traversed the curved rolling track 17 and the straight section of the path 67 is reached, the maximum restoring force is stored in the springs 49, 50 and the tensioning lever 19 in reached its extreme deflection. In the process, the clamping lever 19 - or also the cam disk moves over - A pulse generator 51, which is preferably a photo-reflex light barrier 51 is. As a result, a stop pulse for the electric motor 69 is generated, which this in this position continues

The functional sequence described up to this point takes place over a large period of time compared to the time span of the actual cutting process, which lasts only a few milliseconds. The length of time for the functional sequence is the minimum printing time for a line, possibly also dei Minimum transport time for a line, if the Vorrich device is used for a printer.

The electric motor 69 now stops until it receives a further switching pulse, which, for example, turns off a software control of the program to be printed can originate. In the meantime it has been due the rotation of the gear 12, the pin 56 moves along the arm 40 and is now with the inclined plane 47 of arm 40 in operative connection. the Stopteil'.ing of the electric motor 69 and thus of the cam 14 is dimensioned such that the pin 56 just stops at the beginning of the inclined plane 47 and against the arm 40 starts up. If the electric motor 69 starts again, the gear 12 continues to rotate, the pin 56 lifts the arm 40, as a result of which the retaining pin 38 of the lever 31 slides out of the recess 46. Simultaneously but the wheel 18 slides on the straight path 67, which is why the clamping lever 19 in the cocked Position remains blocked. When releasing the retaining pin 38 from the recess 46, the lever 31 is now through the Spring 49 rotated clockwise at high speed and high torque.

The axis of rotation 32, which is at the same time the drive axis of rotation for the shear knife 58. moves this thus along the stationary blade 64 (F i i. '. 3) at high speed. This is stored in the spring 49 Restoring force within a few milliseconds along the short cutting path in kinetic kinetic energy of the cutter 58 implemented. Because the cutting path is much smaller than the deflection of the Tension lever 19 and because the time span is much smaller, the inside of the stored during the long time span The restoring force of the spring 49 is converted into kinetic energy of the shear blade, this works with a high torque, which means that the recording medium can be sheared off quickly and safely with the slightest Performance of the electric motor 69 is guaranteed.

If the gear wheel 12 and thus the cam disk 14 are now slightly further rotated, this overruns Wheel 18 of the tensioning lever 19, the end 54 of the rolling track, whereby the second, also tensioned spring 50 the Clamping lever 19 moved back in the counterclockwise direction, which is why the wheel 18 is the straight path section 68 of the cam disc 14 falls along again to the beginning 55 of the roll-off track 17. At the same time, the spring 49 presses the Lever 31 in its starting position, at the same time the pin 56 slides back into the recess 52 of the arm 40. at the return movement of the lever 31 in its end position, the retaining pin 38 locks again behind the recess 46 of the arm 40, whereby the lever 31 and thus the cutting knife 58 in turn in their end positions are blocked.

F i g. 2 shows the device in the assembled state, integrated with a printer, in particular a thermoelectric printer, as is known from German patent 30 38 867. The printer 57 has its own drive motor 61 mounted on a side plate 60, the opposite side plate is at the same time the side plate 1 of the cutting device

In addition, this printer 57 has a shaft 63 which is arranged pivotably through a predetermined angle in the side plates 1, 60. The shaft 63 carries the Shear blade 58, which has a cutting edge Opposite this shear blade or the shaft is a stationary blade 64 arranged, which is mounted, for example, on a spar 59.

According to FIG. 3, the shaft 63 with the cutting knife 58 and the spar 59 with the blade 64 are in the immediate vicinity The vicinity of the roller 65 and the print head 66 of the printer 57 are arranged. As it is known, can while the stationary blade 64 with cutting edge can be arranged to be movable in a spring-loaded manner to a certain extent To achieve yield compared to the shear blade 58. Fig. 4 shows the cam 14 in detail Cam disk 14 has on its front edge the roll-off track 17, which is an involute that is shortly before its furthest end 54 from midpoint 15 in

ίο a straight stretch of road 67 comes to an end. At the end of 54 the Abrollbahfi or the straight path section 67 is followed by a long straight path section 68, this straight path sections 67, 68 preferably enclose an acute angle alpha. The straight stretch of road 68 again leads back to the beginning of the runway. Because the straight path pieces 67, 68 have a point Include angle, the clamping lever 19 when rolling over the tip 54 or the end of the straight Path piece 67 suddenly released, that is, the wheel 18 falls under the force of the spring 50 that straight Path section 68 along without rolling along this path section 68 with significant friction.

The lever 31 (Fig. 1) is a twin lever with two parallel arms 35, 36 running, which cut out a gap 70 between them, the width of which is wider is than the thickness of the cam 14. The arrangement of the cam 14 and the lever 31 is such, that in the sequence of movements described above, the cam plate 14 dips into the space 70.

This enables the compact and narrow design of the device according to the invention.

The straight path section 67 which may be present at the end of the roll-off track 17 and into which the roll-off track 17 passes over, can be kept very short, since the length of this path section 67 also determines the cutting duration.

List of reference symbols

1
2
3
4th
5
6th
7th
8th
9
10
Il

Side plates
Spacers

Plug-in pin

Holes

Dotted line

Gear reduction gear or gear bearing

Cam

Journal

camp

Rolling track in involute shape wheel

S-shaped tension lever

Journal

camp

Inclined end face
Fixed counter bracket
hole

axles
Guide slots

31 Twin hooks 5 Drive axis of rotation 32 camp 33
34 Parallel arms 35
36 axis 10 Retaining pin wave 37 poor 38 Shaft journal 15th 39 camp 40 Pen 41 Coiled spiral spring 42 1
43 y Recess 20th 44 Inclined plane 45 Retaining pin 46 Tension springs 47 Photo reflex light barrier -TW Recess 25th 49 1
50 f top 51 End of the taxiway 52 Beginning of the taxiway 53 Pen 54 printer 30th 55 Shear knife with cutting edge 56 Spar 57 Side wall 58 Drive motor of the printer 59 Cut strips of the 35 60 Recording medium 61 wave 62 Cutting edge roller 63 Printhead 40 64 Straight stretch 65 Straight stretch 66 Electric motor 67 Space between the parallel arms of the 45 68 Twin levers 69 Acute angle between the sections 67.68 70 For this purpose 2 sheets of drawings alpha

50

55

60

65

Claims (2)

Patent claims: 1. Method for cutting a record-bearing web, as used in printers or Office machines are used, with a shearing device with an electric drive and a movable one Shear knife, which rotates by a specified angle to cut the web becomes, at the cutting edge of another, stationary Stroke along the blade and then returns to the starting position, with the electric Drive stores energy in a mechanical spring drive to move the cutting blade, characterized in that the electnsehe Drive its energy essentially evenly during the minimum printing and / or transport time for a print line of the printer via a translation into the spring drive as mechanical Energy specnert after reaching a given Path or a predetermined time is stopped by an electrical signal and that after Receipt of a trigger signal, the electric drive is switched on again, then the movable one Shear knife suddenly moved against the blade and immediately after the end of the cutting process the cutter is quickly reset in preparation for a new cutting cycle until including the shutdown of the electric drive. ,. . » 2 Device for cutting off a record-bearing Bahr, such as > - ~. in printers or office machines is used with a shearing device with an electric an ·} eb and a movable shearing knife, which is rotated by a predetermined angle to cut the web, sweeps along the cutting edge of another stationary blade and then returns to the starting position, the electrical drive stores energy in a mechanical spring drive, with a cam disc that has a roller track on which a tensioning lever is used . Tensioning of the spring drive is tracked for carrying out the method according to claim 1, characterized by the following features: