Claims
- 1. A printing mechanism including:
- a carriage movable laterally along a printing line and including a type wheel rotatable to position a selected one of a plurality of type elements carried by said type wheel into a printing position along said printing line;
- means for holding said carriage in a selected position along said printing line, said holding means including a resilient element biasing said carriage toward a first position along said printing line, a drum interconnected to said carriage by a string held to said drum for moving said carriage to a selected position by rotation of said drum, a ratchet secured to said drum for rotation therewith and a retention means operatively engaged with said ratchet for holding it against rotation;
- a hammer having a hammer head extending longitudinally along said printing line;
- means for feeding paper between said hammer head and the type element in said printing position;
- means including a first electromagnetic plunger operatively connected to said hammer and said ratchet for pivoting said hammer to cause said hammer head to strike the printing element in said printing position through said paper during movement of said first electromagnetic plunger in a first direction, and for rotating said ratchet to turn said drum and move said carriage laterally to the next printing position along said printing line during movement of said electromagnetic plunger in a second direction; and
- means for releasing said retention means from said ratchet to cause said carriage to return to said first position while actuating said paper feed means to advance said paper, said releasing and actuating means consisting essentially of a second electromagnetic plunger and means for transmitting motion from said second electromagnetic plunger to said retention means and said paper feeding means.
- 2. A printing mechanism according to claim 1, said type wheel being mounted on a shaft for rotation therewith, said type wheel being slidable along said shaft, and a stepping motor operatively connected to said shaft for rotating said type wheel to position a type element into said printing position.
- 3. A printing mechanism according to claim 1, said retention means including a movable pawl biased into engagement with said ratchet, said paper feeding means including a paper feed roller mounted to a rotatable shaft and a ratchet wheel mounted to said shaft for said paper feed roller, said motion transmitting means including a pivotal lever connected to said second electromagnetic plunger, said lever having a first arm adapted to move said pawl out of engagement with said ratchet and a second arm having a claw adapted to rotate said ratchet wheel during movement of said second electromagnetic plunger.
- 4. A printing mechanism according to claim 1, said pivoting and rotating means further including a hammer lever connected to said first electromagnetic plunger and adapted to engage said hammer and pivot same during forward movement of said first electromagnetic plunger, and a feed lever connected to an end portion of said first electromagnetic plunger, said feed lever carrying a claw adapted to ride over the teeth of said ratchet during forward movement of said electromagnetic plunger and engage one of said teeth to turn said ratchet during return of said first electromagnetic plunger.
- 5. A printing mechanism according to claim 4, including a second type wheel rotatable to position a selected one of a plurality of second type elements carried by said second type wheel into a printing position along said printing line, said second type wheel being laterally fixed in position along said printing line, a second hammer having a second hammer head located oppositely the printing position of said second type elements, said hammer lever being movable between two positions, a first of which engaging said hammer and a second of which engaging said second hammer.
- 6. A printing mechanism according to claim 5, further including means for changing said hammer lever from one of its positions to the other, said changing means including a change-over lever having a first arm adapted to ride on a cam element connected to said drum and a second arm connected to said hammer lever, said cam element being adapted to pivot said change-over lever to place said hammer lever into its second position engaging said second hammer during the printing of the first character of each line of print and into its first position thereafter.
Priority Claims (1)
Number |
Date |
Country |
Kind |
51-84346 |
Jul 1976 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 815,714 filed July 14, 1977 and now abandoned.
US Referenced Citations (12)
Continuations (1)
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Number |
Date |
Country |
Parent |
815714 |
Jul 1977 |
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