Zoltan Braille Embosser.

The Zoltan Braille Embosser (ZBE) is a computer controlled rotary press, which produces interpoint braille; the press can also print on only one side of the paper. General principles With the ZBE the different activities for producing braille print, which previously have been performed as separate subroutines, are now combined in one continuous system. The subroutines are: 1. The processing of text, i.e., translation of text stored on any data carrying medium (paper tape, magnetic tape or floppy disc) into a braille format including automatic generation of braille abbreviations etc. 2. The setting of braille text on the printing drums. 3. The rotary printing, cutting and sorting of interpoint braille. The core of the system is the press with two printing drums fitted with nearly 13,000 printing pins, each of them can be locked in two positions. The setting of the pins is determined by 144 setting magnets. The setting and the supervision is done by a computer program through a hardware interface. The computer transmits orders about setting of magnets, starting and stopping of motors etc. There are also signals going from the press back to the computer program carrying information of states and positions in the press.

The press is fitted with an extensive protection system to prevent mechanical damage arising from erroneous orders sent from the computer or from any other source. The press is provided with a panel for manual operation, which permits manoeuvering and positioning of the ZBE when the computer is disconnected from the press. The computer is equipped with facilities for reading the text. There is also a typewriter, which forms the control console for the operator in determining the work of the press. 

 Mechanical construction 

The main parts of the press are two printing drums and two textloading devices. Each drum is fitted with 6480 pins corresponding to every point position on one page in the book format of 36 characters in 30 rows. The details of the printing drums can be divided into two groups - one group belonging to an axle and following the rotation of that axle - and the other group, which can be revolved relative to the former group. This later group of parts forms the outer cylinder and consists of 72 holding rings. The task of these rings is to form a housing for the pointforming pins, dimension being 11.7 mm long, cylindrical with diam. 1.2 mm. The pins are radially movable from a pulled in position, when the pins are completely beneath the surface of the outer cylinder, to a pushed out position .6 mm outside the surface of the outer cylinder. The holding rings are exposed to an axial pressure coming from press sockets, forming the bearing between the outer cylinder and the axle. In the lower drum there is a free-wheel clutch inserted between the press socket and the axle. By this arrangement the relative rotation between the outer cylinder and the axle can only occur in one direction thus giving the extra advantage of protection against wrong direction of motor revolution. The axles and the details attached to them are connected via gear wheels. The torque is supplied to the lower drum by the aid of a gear belt wheel and a gear belt from the printing motor. The other movable system (outer cylinder with pins and pin-locking arrangements) are also linked together by the aid of gear wheels, attached to the ends of the outer cylinders. An auxiliary driving axle with gear wheels and an incremental decoder also are part of this system. The torque for moving the outer cylinder contra the axles comes from the loading motor by the aid of a ratchet-and-pawl mechanism.

Sequence of operation

The production of braille is performed in two phases. During the first phase (loading phase) the text, which has been read into the computer, will be transferred to the printing drums by the aid of the loading mechanisms. The axles, with inner parts attached, are standing still while the loading motor steps the outer cylinders at low speed. The pins are forced out to printing position erasing the old text. The new text is then loaded into the drums by the loading mechanisms so that only those pins, which are not forming parts of the characters are pushed in. By further revolution of the outer cylinder the pins will be locked in their new positions. The manoeuvering of the pins can be looked upon as divided between actions inside the drums by the so-called inner mechanism and activities by an outer apparatus - the loading mechanism. Forcing the pins out to the printing position and locking them is performed by the inner mechanisms while the loading mechanisms determine the pushing in of the pins. The loading phase is completed after one revolution of the outer cylinder which takes about 30 seconds. There is no printing occuring during this phase because the upper drum is lifted thus disengaging the hold of the paper. Following this phase the printing phase begins. After the upper drum has been lowered on the lower one the printing motor is started and its torque is transferred to the axle of the lower drum and further to the outer cylinder via the free-wheel clutches, which now are exposed to a rotation in their holding direction. The upper drum follows the rotation of the lower by the aid of the gear wheels on the axles and on the outer cylinders. m The number of pages printed is determined by the operator. 1 The printing speed is 4-5 interpoint pages per second. It should be noted that the only parts, which are actually I moving during the printing procedure are the drums and the driving motor. The printing phase is automatically followed by a f* new loading phase for the next sheets of the printed matter etc.

Devices for manoeuvering and electronic control

 Besides the above mentioned motors there are three other motors and a set of pushing or pulling magnets for pn I the operation of catches, clutches and brakes. P A large group of magnets are to be found in the loading mechanisms. There are 72 of them in each unit correp sponding to 72 pin positions along the horizontal 1 direction of the drum. Every one of these devices are _ connected with registers in the electronic control unit I (the hardware interface), the registers in turn receiving information from the computer. Besides these active devices there are some passive F transmitters delivering signals through the interface about the actual status of the press. The press is fitted with a manual panel, which enables activation of motors and magnets. The panel is used when to locate faults, running in of the press and " inserting paper in the machine. 

Internal protection aids

Computer control as well as mahual operations from the above mentioned panel could result in erroneous orders to the press, eventually causing damage. In order to protect the press against such situations it has been equipped with internal logic circuits based on fast relays. The main task of this logic is to separate the operations «•* of the loading phase from those of the printing phase. ...I Operations belonging to one of these phases can not appear during the other.

The current status of the press.

The press has been built as an experimental model with 36 x 29 characters/drum. The machine is complete and test printing has been accomplished. The whole system has been tested when all parts for manoeuvering were under the control of the computer program. Test prints of book-format or of format A4 will be available within a short time and will then be distributed for feedback on the acceptability of the end product. 

Manufacturing 

The ZBE has been developed at Trask Datasystem AB and has been economically sponsored by the Swedish Board for Technical Development (STD). Provided that interest will accumulate for this printing apparatus and that the result of test-runnings are positive, a series of 10 copies of the ZBE is planned. The price for a complete press including interface, computer and software is estimated to 600,000 Sw kronor (circa $125,000). Further details are available from Trask Datasystem Ab, Stockholmsvagen 34, S-182 74 Stocksund, Sweden