[GreenKeys] Carriage return questions

[Sheldon Daitch]

 In the trivia department, perhaps, but some of the Extel printers, the smaller dot matrix printers, there were models which had a buffer for the print head printing mechanism that relied on the print head returning to theleft margin position, striking a small electrical contact before the machine would start printing the next newline.

The buffer would hold maybe three to five lines of printed text before it would fill up.  When the print headreturned to the left margin, the machine would print text about maybe about 50% faster than the normalcircuit speed until it caught up with the incoming traffic.  

No, the machine was never that many lines behind unless someone was holding the print head away fromthat left hand margin contact, just to watch it fast print.
73Sheldon

    On Friday, May 15, 2020, 11:03:45 AM EDT, steve.n4tty at gmail.com <steve.n4tty at gmail.com> wrote:  
 
 Interesting point!  The coiled spring in the drum of a 28 would cause travel of the carriage at the same speed independent of the WPM.  I never even had that cross my mind.  The Kleinschmidt's were controlled by the speed of the shafts, so they changed with gear speed changes.

Steve G./N4TTY

-----Original Message-----
From: Paul Heller <paul0926 at comcast.net> 
Sent: Friday, May 15, 2020 10:55 AM
To: steve.n4tty at gmail.com
Cc: Mike Dodd <mike at mdodd.com>; GreenKeys at mailman.qth.net
Subject: Re: [GreenKeys] Carriage return questions

The whole design has always fascinated me. I wonder how hard it was for them to perfect it.  It is pretty amazing that a model 28 can return fast enough when running at 100WPM. 

Paul
W2TTY

> On May 15, 2020, at 8:43 AM, steve.n4tty at gmail.com wrote:
> 
> Aren't they all "older" now?  😊
> 
> The 15/19 family used a coiled spring that retracted a belt attached to the carriage.  The 28 family also used a coiled spring in a drum that the wire that moved the type box carriage could return to the left margin rather quickly.  Both the 15.19 and 28 families had a dashpot that cushioned and slowed the return to a somewhat controlled stop.  The Kleinschmidt machines returned the carriage by using the main shaft through a set of clutches to actuate the return mechanism.
> 
> Hope that helps and others please jump in and correct any errors in my recollection of the 'older" machines by my older mind!
> 
> Steve G./N4TTY
> 

> ______________________________________________________________




  
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