EP0028838A2 - Device for writing in braille - Google Patents

Abstract

In a device for writing Braille, a web to be embossed runs underneath an embossing die (3) which is provided with depressions (5) for a line of dots to be embossed. A series of stamps (9) is arranged under the stamping die (3). By means of actuating members (23, 24, 25) that can be moved transversely to the punch stroke direction, the stamping dies (9) can be moved in and out of engagement with an embossing bar (20), which executes continuous lifting movements, based on coded signals. Only the embossing dies (9), which are respectively engaged with the embossing bar (20), carry out an embossing. The embossing stamps (9) are pivotally received in stamp bores (8) of a guide plate (7). A hold-down (32) in the form of a comb connected to the embossing bar (20) engages behind each stop (9.4) of each embossing die (9) each time the embossing bar (20) moves downward.

Description

The invention relates to a device for writing Braille with an embossing die provided with recesses for a dot line, on which a web to be embossed can be moved transversely to the line direction, and with a row of embossing stamps arranged according to the dot line, each of which is optionally based on coded signals an embossing stroke for embossing a point of the line can be controlled by means of an actuating member and are guided in stamp bores in a guide plate.

In a known device of this type (US Pat. No. 3,880,269), each individual embossing stamp is connected to an associated electromagnet which exerts the embossing force. The control of the individual dies is carried out by energizing the associated electromagnet. The energy required for the respective control signal is therefore relatively large because it must also exert the force required for the stamping process.

In the known device, the return stroke of the stamping dies is carried out by springs, the force of which must also be overcome during the stamping stroke. Because of the high forces to be transmitted, the device must be relatively heavy. The masses to be moved with each stamp movement are very large, so that the working speed is relatively low.

The object of the invention is therefore to implement a device of the type mentioned in such a way that the embossing process can be carried out with very low energy requirements for the signals driving the individual actuators, so that the device can be easily designed and designed for a high working speed.

This object is achieved with the characterizing features of claim 1.

The force required for the embossing process is applied exclusively by the drivable embossing bar; the actuators only serve to control the embossing dies by bringing the embossing dies into and out of engagement with the embossing bar. Since the direction of movement of the actuating members runs transversely to the punch stroke direction, the actuating members lie completely outside the force flow of the force applied during the stamping process. The signals supplied to the actuators therefore require very little energy; the forces occurring between the actuators and the dies are very low, so that the parts required for power transmission very easily ge can be selected. The small masses to be moved enable a very high working speed. The; Force flow for the embossing process runs directly from the embossing bar in the longitudinal direction of the embossing stamp.

Only a very small force is required to control the individual dies, because the dies only have to perform a pendulum movement.

It is known in a device for writing Braille (US Pat. No. 3,876,052) to use actuators for selecting the stamping dies to be controlled for the stamping process, the direction of movement of which is transverse to the stamp stroke direction. In this known device, however, only individual embossing dies, each of which has the depressions for six points, are moved transversely to the punch stroke direction by these actuating members. The stamps for a complete line of Braille characters are formed on six common stamp carriers. With each embossing process, these embossing stamp carriers are moved in such a way that all embossing stamps of the entire line are actuated in the manner required for a specific character, but only a single embossing die is brought into engagement with the embossing stamps at the point at which the character is to appear.

In the known device, the force required for the embossing process must also be applied by those actuators which control the six stamp carrier. In addition, a complete line of dots cannot be used for each embossing process, but only a single braille character can be embossed, so; that as many embossing processes are required to create a character line as the line contains characters.

It has proven to be particularly advantageous in each case to provide the embossing dies with a stop which is engaged behind by a hold-down device connected to the embossing bar. It is thereby achieved that all stamps are inevitably moved back by a positive engagement during the return stroke of the stamping bar, so that there is no danger that a spring force provided for the stamp return stroke is not sufficient in some cases to withdraw the stamp. In addition, it is not necessary to overcome the force of such return springs during the stamping stroke, it must be taken into account that the sum of these spring forces would be very high with a larger number of stamps.

The holding-down device is expediently designed as a comb, in the tine slots of which an embossing die is movably guided, each embossing die having a collar as a stop in its section arranged between the holding-down comb and the stop surface. It is thus achieved in a very simple manner in terms of construction that the stamping die can carry out the required pendulum movement without the hold-down device impairing this pendulum movement.

In a further development of the inventive concept, it is provided that the embossing dies each have a shoulder or collar, which with the return stroke movement with one Guide plate connected stop surface engages, which is expediently formed by a comb plate arranged below the guide plate. As a result, the dies are suspended in a freely swinging manner, so that no further constructive measure is required to guide the dies in their longitudinal direction when the dies are out of engagement with the die at one end. The comb shape of this stop surface enables easy assembly of the dies.

The actuating members are advantageously electromagnets with a direction of movement extending transversely to the punch stroke direction, each of which is connected to an embossing punch via an actuating tab. The actuating tabs allow a deflection perpendicular to the direction of movement of the electromagnets without having to provide movable guides on the embossing dies or without a retroactive effect of the embossing force on the electromagnets.

Further advantageous refinements of the inventive concept are the subject of dependent claims.

• Fig. 1 in einem senkrechten Schnitt die für den Prägevorgang wesentlichen Teile einer Vorrichtung zum Schreiben von Blindenschrift,
• Fig. 2 einen Teilschnitt längs der Linie II-II in Fig.1,
• Fig. 3 einen Teilschnitt längs der Linie III-III in Fig.2,
• Fig. 4 einen vergrößerten Ausschnitt aus Fig. 1 zur Darstellung von Einzelheiten der Anordnung und Betätigung der Prägestempel,
• Fig. 5 ein gegenüber der Fig. 4 abgewandeltes Betätigungselement, das als piezoelektrisches Biegeelement ausgebildet ist,
• Fig. 6 eine perspektivische vereinfachte Darstellung der in Fig. 4 gezeigten Teile,
• Fig. 7 in einem Schnitt ähnlich der Fig. 1 eine Ausführungsform, bei der die Betätigungselemente für die Prägestempel beiderseits der Reihe von Prägestempeln angeordnete Magnete sind,
• Fig. 8 die Ausführungsform nach Fig. 7 in einer vergrößerten Darstellung ähnlich der Fig. 4,
• Fig. 9 einen Teilschnitt längs der Linie IX-IX in Fig. 8,
• Fig.10 in einem Teilschnitt eine abgewandelte Ausführungsform der Prägematrize und
• Fig.11 eine weitere abgewandelte Ausführungsform in einem Teilschnitt ähnlich der Fig. 8 .

The invention is explained in more detail below using an exemplary embodiment which is illustrated in the drawing. It shows:

• 1 shows in a vertical section the parts of a device for writing Braille that are essential for the embossing process,
• 2 shows a partial section along the line II-II in FIG. 1,
• 3 shows a partial section along the line III-III in FIG. 2,
• 4 shows an enlarged detail from FIG. 1 to show details of the arrangement and actuation of the embossing dies,
• 5 an actuating element which is modified compared to FIG. 4 and which is designed as a piezoelectric bending element,
• 6 is a perspective simplified representation of the parts shown in Fig. 4,
• 7 in a section similar to FIG. 1, an embodiment in which the actuating elements for the dies are arranged on both sides of the row of dies,
• 8 shows the embodiment of FIG. 7 in an enlarged view similar to FIG. 4,
• 9 is a partial section along the line IX-IX in Fig. 8,
• 10 is a partial section of a modified embodiment of the embossing die and
• 11 shows a further modified embodiment in a partial section similar to FIG. 8.

A web 1 (FIG. 1) made of strong paper or thin cardboard is moved by a drive device, of which only a driven star wheel 2 is indicated, under an embossing die ³ / which is fastened in a machine frame 4 and has depressions 5 ( Fig.4). The web 1 runs over a guide surface 6, of which only a section is shown in FIG. 1. In the guide surface 6 there is a guide plate 7, in which 5 punch bores 8 are arranged in a row under the depressions. Embossing dies 9 protrude through the punch bores 8, the upper ends of which are rounded off in a hemispherical manner corresponding to the depressions 5. If the Embossing stamp 9 are moved upwards, they emboss approximately hemispherical bulges in the web 1, which form the points from which the individual characters. the braille are composed.

A belt drive 10, which is only indicated in FIG. 1, drives an eccentric shaft 11 on which a plurality of eccentrics 12 are seated next to one another, each of which eccentrically carries a roller bearing 13. The eccentric shaft 11 is rotatably supported by means of roller bearings 14 in arms 15 which are attached to a support bracket 16 which is mounted in the machine frame 4 in a height-adjustable manner. The support bracket 16 can be adjusted against the force of a plate spring assembly 18 in the machine frame 4 by means of a screw 17 (FIG. 3).

The roller bearings 13 are guided in C-shaped supports 19 which are open on one side and which are connected to a common embossing bar 20. In each case two vertical pins 21, which are attached to the support beam 16, engage in mutually aligned bores 22 of the supports 19, which are guided so that they can move in the vertical direction relative to the support beam 16.

When the eccentric shaft 11 rotates, the supports 19 and the embossing bar 20 are moved up and down.

The upper portions of the die 9 have in the punch holes 8 so much play that the die 9 in the manner shown in Figure 4 are pivoted kö _n - NEN.. For this purpose, each embossing die is connected to a horizontal actuating glass 23 at a tapered section 9.1 located in its lower region grips around the tapered section 9.1 in a fork-like manner. At its other end, the actuation tab 23 is connected to an armature 24 of an electromagnet 25.

In the position shown in solid lines in FIG. 4, the lower end of the die 9 is supported on a stop surface 26 of the die bar 20. The stop surface 26 is formed by a hardened steel strip 27 which lies on a stop rail 28 which is connected to the embossing bar 20 by means of a screw 29.

When the electromagnet 25 exerts a tensile force in the horizontal direction (arrow P1), the die 9 is pivoted into the position shown in broken lines in FIG. 4, its lower end disengaging from the stop surface 26. If the lower end of the stamp 9 is above the stop surface 26, the stamp 9 is raised during a stroke of the stamping beam 20 and carries out an stamping process. However, if the lower end of the stamp 9 is located to the side of the path of movement of the stop surface 26, the stamp 9 is not lifted during the lifting movement of the stamping beam 20, so that no stamping takes place. In this way, the electromagnets 25 can control the stamping dies 9 assigned to them in such a way that the stamping stamps 9 either carry out an embossing or not during the lifting movement of the embossing bar 20.

So that the die 9 in the deflected position, in which it is not above the stop surface 26 be find, can not fall too deep, the dies 9 have a collar 9.2 below the guide plate 7, which engages with a comb plate 30 attached under the guide plate 7. The comb plate 30 thus forms a stop for each collar 9.2 of the die 9.

Via an angle rail 31 screwed onto the side of the embossing bar 20, a hold-down 32 designed as a comb is attached, in the tine slots 33 of which a tapered section 9.3 of the embossing die 9 is guided vertically and movably in the transverse direction. Below the comb 32, each die 9 carries a collar 9.4, which engages with the underside of the comb 32 in order to take the die 9 with it when the embossing bar 20 moves downward. The direction of movement of the die 9 is shown by the arrow P2.

Instead of the electromagnets 25, piezoelectric bilaminar bending elements 34 (FIG. 5) can be used as actuators for the swiveling movement of the embossing dies 9, said bending elements performing a bend when an electrical voltage is applied, as is indicated in FIG. The piezoelectric bending elements 34 can also each be arranged parallel to the associated die 9 and connected to it. This gives a particularly space-saving structure.

In Fig. 2 it can be seen that the embossing die 3 is pivotally mounted on both sides in the machine frame 4 by means of a pivot pin 35. A coni _s locking pin 36, which is displaceable in its longitudinal direction, holds the embossing die 3 on both sides in the operating position shown. After this. When the two locking bolts 36 are loosened, the embossing die 3 can be folded up, for example to enable monitoring or cleaning in the embossing area.

The actuation of the electromagnet 25 occurs by an in Fig. 1 only indicated the control circuit 37 ₁ for each revolution of the eccentric shaft 11 receives a signal from a photo cell 38. Coded signals are supplied to the control circuit 37 via a control input 39, from which it follows whether or not an embossing should take place at the point of the web 1 located above an embossing stamp 9 during the next rotation of the eccentric shaft 11. Accordingly, the die 9 is either held in engagement with the stop surface 26 or pivoted out of engagement with the stop surface 26. Since the dies 9 are guided in the die bores 8 and on the comb plate 30 so that a free oscillation is possible, the force to be exerted by the actuators 25 and 34 for the pendulum movement of the dies 9 is very low. The game of the stamp 9 in the stamp holes 8 is also such that the paper dust accumulating during the stamping process can fall down and that self-centering of the stamp 9 in the recess 5 of the stamping die is possible during the stamping process.

It goes without saying that the pendulum movement of the stamping dies 9 can only be carried out when the stamping bar 20 is is at least approximately in its lower position. The lifting movement is synchronized with the pendulum movement of the stamping dies 9 by means of the photocell 38.

The tapered embossing die end 9.1, on which the fork-shaped actuating tab 23 engages, also forms a predetermined breaking point when the embossing die 9 is subjected to an impermissibly high load on buckling. In this way it is ensured that no major damage occurs in the device in the event of an overload, because only a relatively easy-to-replace part, namely the die 9, is destroyed.

The embodiment shown in FIGS. 7 and 8, in which the same reference numerals as in the previous figures have been used for the same parts, differs from the embodiment according to FIGS. 1-5 essentially in that on one side of the series of Embossing dies 9 are arranged a series of electromagnets 40 each associated with an individual embossing die 9. Each electromagnet 40 each has a U-shaped core 41, the two ends of which are turned towards the die 9. One or both core legs each carry a magnetic winding 42. All electromagnets 40 are cast into a common electromagnetic strip 43 (FIG. 8). The surface of the electromagnets 40 facing the embossing dies 9 is provided with a friction-reducing plastic layer 44, which consists for example of PTFE.

On the opposite side of the series of dies p _el n 9, a permanent magnet strip 45 is arranged, which is attached to a carrier 46. The carrier 46 is connected to an eccentric 47 mounted in the machine frame, which is in drive connection with the eccentric shaft 11 for the lifting movement of the embossing bar 20 via a slip-free belt drive 48. About this Getriebeverbin- _du ng the permanent magnetic strip 45 is in synchronism transversely to the direction of the back die 9 with the lifting movement of the emboss bar 20 back and forth.

The excitation of the electromagnets 40 is controlled by the control circuit 37 in such a way that at the beginning of each lifting movement of the embossing bar 20 only the electromagnets 40 are energized for those embossing dies 9 which are to carry out an embossing process. On the stamping dies 9 exerted by the electromagnets 40 of magnetic force is groES _s er than the magnetic holding force of the permanent magnet strip 45, moving away at the beginning of the stroke movement of the stamping bar 20 laterally from the dies. 9 Therefore, those dies 9 whose electromagnet 40 is energized at this moment are held on the electromagnet 40 and come into engagement with the stop surface 26 of the embossing bar 20. The other dies 9, the respectively associated electromagnet 4o of which is not energized, follow the permanent magnet strip 45 and are pivoted into the position indicated by dash-dotted lines in FIG. 8 so that they do not engage with the stop surface 26.

The embossing dies 9 held by the electromagnets 40 slide along the plastic layer 44 during the embossing movement. About the friction that occurs To reduce further, the control circuit 37 can be designed such that shortly after the start of the lifting movement of the embossing bar 20 it also switches off those electromagnets 40 which were initially excited and which held the respectively assigned embossing die 9. In order to prevent the embossing dies 9, which are then no longer held by the electromagnets 40, from following also the magnetic force of the permanent magnetic strip 45, a fixed comb strip 49 (FIG. 9) is provided, the comb teeth of which 50 form guide surfaces 51, on which a cylindrical one Outer surface section 52 of the respective raised die 9 rests. As a result, the stamping dies 9 which have already been lifted are guided in the vertical direction and it is prevented that these stamping stamps 9 can swing out laterally as soon as the electromagnets 40 are switched off.

However, in order to enable a pivoting movement of those dies 9 which are to be disengaged from the abutment surface 26, the dies 9 have a constriction 53 above the cylindrical outer surface section 52, each of which fits into a space 54 between the comb teeth 50. Therefore, the stamping dies 9 can be swung out laterally in their lower position by the permanent magnet strip 45, the constriction 53 in each case entering a tine space 54.

Instead of the mechanically moved permanent magnet strip 45, it is also possible to provide a fixed electromagnetic strip 55 which is arranged at a distance from the stamping dies 9 (FIG. 11) and which consists of one or more electromagnets ₅ 6 exists, the magnetic coil 57 is energized by a dash-dotted lines in Figure 11 indicated control circuit 58 in the absence _h ä _n dependence supplied by the by the photocell 38 or other sensor signal so that the dies are pivoted laterally 9, provided they cannot be held by the respectively assigned electromagnet 40. During the return of the die 9 is effected to the initial position by the return movement of the perma- _ne ntmagnetleiste 45 to the positions shown in Figs. 7 and 8 starting position in the embodiment of FIGS. 7 and 8, is carried out in the embodiment of Fig. 11 this feedback in that the electromagnet (s) 56 is switched off and all electromagnets 40 are energized.

_Fi g. 10 shows a modified embodiment of the pre- g _e die 3. At the one longitudinal edge of the stamping die 3 a from the end face 3.1 of the embossing die 3 outstanding, strip-shaped projection 60 is provided at a distance from the series of depressions. 5 This projection 60 causes the paper or cardboard web 1 to be pulled out of the depressions 5 under the pulling action of the star wheel 2. This prevents the parts of the paper or cardboard web 1 pressed into the recesses 5 from getting caught in the recesses 5 when the paper or cardboard web 1 is being transported. This measure allows the force required for the transport of paper or cardboard to be significantly reduced; damage is also avoided.

Claims (10)

1. Apparatus for writing Braille with an embossing die provided with recesses for a dot line, on which a web to be embossed can be moved transversely to the direction of the line, and with a row of embossing stamps arranged according to the dot line, each of which is optionally based on coded signals for an embossing stroke for embossing a point of the line can be controlled by an actuating member and are guided in stamp bores of a guide plate, characterized in that the direction of movement (P1) of the actuating members (25, 34) is essentially transverse to the stamping stroke direction (P2) and that the embossing dies ( 9) can be pivoted in the punch bores (8) by means of the actuating members (25, 34) in such a way that the ends of the stamping dies (9) facing away from the stamping die (3) engage in and out of engagement with a stop surface (36) of an embossing bar which can be driven for continuous lifting movements (20) are movable. 2. Device according to claim 1, characterized in that the embossing dies (9) are each provided with a stop (9.4) which is engaged by a hold-down device (32) connected to the embossing bar (2o). 3. Apparatus according to claim 2, characterized in that the hold-down device is designed as a comb (32), in the tine slots (33) of which an embossing die (9) is movably guided, and in that each embossing die (9) in its between the hold-down comb ( 32) and the stop surface (26) arranged section as a stop has a collar (9.4). 4. The device according to claim 1, characterized in that the embossing stamp (9) each have a shoulder or collar (9.2) which, during the return stroke movement, engages with a stop surface (3 ₀ ) connected to the guide plate (7), which passes through a comb plate (30) arranged below the guide plate (7) is formed. 5. The device according to claim 1, characterized in that the actuators are electromagnets (25) or piezoelectric bending elements (34) with transverse to the punch stroke direction (P2) moving direction (P1), each via an actuating tab (23) with an embossing stamp (9 ) are connected. 6. The device according to claim 1, characterized in that the actuators on one side of the Row of embossing dies (9) arranged, the embossing dies synchronously with the lifting movements of the embossing bar (20) swiveling magnetic bar (45,55) and on the opposite side of the row of embossing dies (9) a number of each assigned to a single embossing stamp, individually selectively excitable Have electromagnets (40), the stamping dies (9) forming the electromagnetic armatures. 7. The device according to claim 6, characterized in that the swivel magnetic strip is a permanent magnetic strip (45) which is in drive connection with the embossing bar drive (11) and on the row of embossing dies (9) to and from them can be moved. 8. The device according to claim 6, characterized in that the Schwenlcmagnetleiste consists of at least one fixed electromagnet (56) which can be excited synchronously with the stroke movements of the embossing bar (20). 9. The device according to claim 6, characterized in that all electromagnets (40) by means of a switch (37, 38) which can be actuated by the embossing beam movement can be switched off together after the start of the upward movement and that each embossing stamp (9) has a lateral stop surface (52) , which only engages with a fixed guide surface (51) in the raised state, that the lateral stop surface of the die (9) is formed by a cylindrical outer surface section (52) will the. underneath a constriction (53) of the die (9), and that the fixed guide surface (51) is formed by comb teeth (50), in whose tine spaces (54) the constrictions (53) of the die (9) fit. 10. The device according to claim 1, characterized in _{that a} on the embossing die (3) in the running direction of the web to be embossed (1) at a distance from the depressions (5) from the end face (3.1) projecting projection (60) is arranged.

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