Compact flying printer

Claim 1

A compact flying printer comprising a continuously rotating print drum; a ratchet wheel having at least one projecting tooth and continuously rotating in synchronization with said print drum; a trigger lever; guide means for guiding the displacement of said trigger lever along a path having rotational and linear componets; a hammer lever; a print hammer carried by said hammer lever for striking engagement against said print drum; means for biasing said trigger lever to a rest position on said path out of the locus of said ratchet wheel tooth and engaging said guide means, said trigger lever being formed with a body portion terminating in a tail portion at one end thereof, a neck portion projecting from said body portion at a position spaced from said tail portion, and an energy transmitting portion on the projecting end of said neck portion, said guide means engaging said trigger lever tail portion to guide the pivotable displacement of said trigger lever about the point of engagement of said tail portion and guide means and to guide the essentially linear displacement of said trigger lever relative to said guide means; means for rotationally displacing said trigger lever along said path in response to the selective application of a print signal to position said energy transmitting portion of said trigger lever in the locus of said ratchet wheel tooth, said guide means including a portion in said path for stopping said rotational displacement, said trigger lever being linearly displaced along said path by the striking of the energy transmitting portion thereof by said ratchet wheel tooth, and means mounting said hammer lever for pivotable displacement in response to being struck by said trigger lever between a first position in the linear path of said energy transmitting portion and a second position at which said print hammer is driven against said print drum, the neck portion of said trigger lever being formed with a striking face means, said guide means including a further portion positioned in said linear path of said trigger lever for engagement by said striking face means before said print hammer strikes said print drum, said striking face means on said neck portion of said trigger lever defining an angle phi with said linear portion of said path followed by said trigger lever after being struck by said ratchet wheel tooth, the angle phi being greater than 90* and less than 180*, whereby said trigger lever is rotatably displaced along said path so as to carry said energy transmitting portion out of the locus of rotation of said ratchet wheel, said guide means guiding the return of said trigger lever to said position.