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ELECTROMAGNETICALLY-ACTUATED PRINTING MECHANISM

  • US 3,822,640 A
  • Filed: 08/16/1972
  • Issued: 07/09/1974
  • Est. Priority Date: 08/17/1971
  • Status: Expired due to Term
First Claim
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1. In a printing mechanism for printing information on a record medium:

  • a movable type-carrying member carrying thereon n sets of print type successively spaced apart from each other in the direction of movement of said type-carrying member;

    electromagnetic drive means responsive to n electric pulse signals for electromagnetically driving said type-carrying member in an intermittent manner in one direction through n equal increments each effected by one pulse signal to effect successive intermittent movement of each set of print type into a common print position thereby defining one printing cycle, said electromagnetic drive means comprising a rotatable ratchet wheel having a set of n/2 ratchet teeth, means connecting said ratchet wheel to said type-carrying member to effect intermittent movement of said type-carrying member in response to intermittent stepwise rotation of said ratchet wheel, a pair of pawls each in engagement with different ratchet teeth of said ratchet wheel and alternately coacting with said ratchet wheel to effect intermittent stepwise movement of said ratchet wheel in response to reciprocatory movement of alternate ones of said pawls, means biasing said pawls into continuous contact with different ratchet teeth of said ratchet wheel, a pivotal plate member having said pawls turnably mounted thereon and operative to alternately reciprocate said pawls in response to reciprocatory pivotal movement of said plate member, means including a pair of electromagnets operative when alternately energized with pulse signal to effect reciprocatory pivotal movement of said plate member thereby intermittently driving said type-carrying member and advancing same through equal increments and means engagable with said ratchet teeth for releasably holding said ratchet wheel and thereby said type carrying member in each successive advanced position;

    control circuit means for selectively developing pulse trains composed of n electric pulse signals and applying alternate ones of the pulse signals to respective ones of said pair of electromagnets to effect alternate energization thereof to control the movement of said type-carrying member; and

    printing means coacting with said type-carrying member for striking one of said sets of print type when same is stationary in said print position to print the information contained on that set of print type on a record medium.

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