Keyboard perforator Type 44

Creed & Company Ltd; East Croydon, Surrey

  • Année
  • 1932 ?
  • Catégorie
  • Appareil morse & TTY, RTTY, TDD, etc.
  • Radiomuseum.org ID
  • 304040

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 Spécifications techniques

  • Tension / type courant
  • Alimentation Courant Alternatif (CA) / 230 Volt
  • De Radiomuseum.org
  • Modèle: Keyboard perforator Type 44 - Creed & Company Ltd; East
  • Dimensions (LHP)
  • 430 x 365 x 380 mm / 16.9 x 14.4 x 15 inch
  • Remarques
  • The Creed Type 44 keyboard perforator is used for the manual preparation of standard 5-hole 11/16 in (17.5 mm) wide punched paper tape. It uses International Telegraph Alphabet No. 2 (Baudot-Murray code), which was introduced by the CCITT in 1924, replacing the Murray code that was used by early Creed machines. In this code, letter-shift and figure-shift characters are used to select between two states; one with 26 alphabetic characters and the other with 24 printing numerals and symbols, plus bell and WRU. In addition to letter and figure shift, carriage return, line feed and space are common to both states, while the all-space code (blank tape) is unused.

    The Type 44 perforator does not have a motor, the punching hammer being operated by an electromagnet that is energised near the end of the key travel, after the combination bars have been set up by the keybar. There is no printing mechanism. A mechanical counter totals the number of keystrokes following each carriage return character, and a lamp is illuminated after about 60 characters as a warning that a new carriage return and line feed should be inserted soon, if the tape is to be used to transmit to a teleprinter with a page printer.

    The maximum speed is about 80 wpm and the keys are not locked, so that an error can occur if a key is depressed before the previous punching operation has completed. A lever is provided to allow the tape to be backspaced, so that an erroneous character can be over-punched with the non-printing letter-shift code (for which all 5 holes are punched). 

    In 1934 the Type 44 perforator was succeeded by the Type 45, which employed a 1500 rpm electric motor and could be operated at up to 130 wpm, so that there was little risk of the operator racing the keyboard.

  • Poids net
  • 20.5 kg / 45 lb 2.5 oz (45.154 lb)
  • Auteur
  • Modèle crée par Bruce Taylor. Voir les propositions de modification pour les contributeurs supplémentaires.

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