Type drum assembly for an on-the-fly printer

Claim 2

A type drum assembly for an on-the-fly printer comprising: a cylindrical type drum having rows of characters grouped on a first portion of its curved surface to form a printing phase and being devoid of characters on a second portion of its surface to form a non-printing phase of the contInuous rotation of the drum, said drum being movable axially to present a selected row of characters at a print line; means for axially positioning the type drum with a selected row of characters at the print line during the non-printing phase of the continuous rotation of said drum; and means independent of said positioning means for maintaining the selected row of characters at the print line during the printing phase and for releasing said print drum to said positioning means during the non-printing phase of the continuous rotation of said drum.

Claim 3

The type drum assembly of claim 1 wherein said positioning means includes a selectably positionable V-shaped cam, partially encompassing said drum and open at its smaller end, and cam follower means on the curved surface of said drum for interacting with the inner surfaces of said V-shaped cam.

Claim 4

The type drum assembly of claim 2 wherein said V-shaped cam is pivotable and also including means for precisely pivoting said cam in a series of axial positions with respect to said type drum.

Claim 5

The type drum assembly of claim 3 wherein said means for pivoting said cam includes a lever pivotally linked to said cam, said lever having two distinct fulcrum points and means for independently shifting said lever into different positions at said fulcrum points.

Claim 6

The type drum assembly of claim 4 wherein said means for independently shifting said lever include means for biasing said lever in one direction and solenoid means for shifting said lever in the opposite direction.

Claim 7

The type drum assembly of claim 5 including a pair of solenoid means operating against bias at each of said fulcrum points said pair of solenoid means acting on opposite sides of said lever.

Claim 8

The type drum assembly of claim 1 wherein said means for maintaining a selected row of characters at the print line during the printing phase and for totally releasing said type drum to said positioning means during the non-printing phase of a rotation of said drum include a substantially semicircular flange fixedly connected to said drum and a comb member having channels for receiving said flange at each position of said type drum at said print line.

Claim 9

The type drum assembly of claim 7 wherein said characters are arranged in four rows and centrally grouped within the projection of said semicircular flange.

Claim 10

A type drum assembly for an on-the-fly printer comprising: a cylindrical type drum having rows of print characters grouped on a first portion of its curved surface to form a printing phase and being devoid of characters on a second portion of its curved surface to form a non-printing phase of the continuous rotation of said drum, said drum being movable axially to present a selected row of characters at a print line; means for controlling the axial position of said drum, said controlling means being actuatable during the printing phase of the continuous rotation of said drum; means rotating with said drum and interacting with said controlling means for axially positioning said drum during the non-printing phase of the continuous rotation of said drum; and means for maintaining the axial position of said drum during the printing phase and for releasing said drum to said controlling means and positioning means during the non-printing phase of the continuous rotation of said drum.

Claim 11

A type drum assembly for an on-the-fly printer comprising: a cylindrical type drum having rows of print characters grouped on a first portion of its curved surface to form a printing phase and being devoid of characters on a second portion of its curved surface to form a non-printing phase of the continuous rotation of said drum, said drum being movable axially to present a selected row of characters at a print line; means for controlling the axial position of said drum, said controlling means being actuatable during the printing phase of the continuous rotation of said drum; means rotating with said drum and interacting with said controlling means for axially positioning said drum during the non-printing phase of the continuous rotation of said drum; and means for maintaining the axial position of said drum during the printing phase and for releasing said drum to said controlling means and positioning means during the non-printing phase of the continuous rotation of said drum.

Claim 12

The type drum assembly of claim 9 wherein said controlling means includes an elongated cam partially encircling said drum and said means rotating with said drum comprises a cam follower fixed on said drum.

Claim 13

The type drum assembly of claim 9 wherein said maintaining means includes a flange rotating with said drum and a slotted member for receiving said flange at different axial positions of said drum.