Double helical printer

Claim 2

A printer comprising a rotatable wheel having type elements each having a predetermined and identical character position width for printing various characters on an object said elements being located on said rotatable wheel in at least two separate helical paths, said paths being offset from one another by less than said character position width, means for rotating said device on its axis one revolution while traversing along its axis a character position width, and means for selectively bringing said type elements into contact with said object to be printed.

Claim 3

A printer as in claim 1 where said selective means includes hammer means mounted for transverse movement with said rotatable wheel and juxtaposed with said helical paths.

Claim 4

A printer as in claim 1 where said rotatable wheel has only two helical paths one path having characters of One type and the other path characters of another type.

Claim 5

A printer as in claim 1 said rotatable wheel has only two helical paths having identical pitches one being offset from the other by one-half of said character position width with a tolerance of + or - 50 percent of one-half of said width.

Claim 6

A printer as in claim 1 where each of said helical paths has an identical pitch which is determined by said character position width and the total number of characters on said rotatable wheel.

Claim 7

A printer as in claim 5 where said rotatable wheel is traversed along its axis at a velocity proportional to the pitch of its helical paths.

Claim 8

A printer as in claim 1 where said characters are arranged in two helical paths one of said paths being offset substantially one-half character position width from the other helical path.

Claim 9

A printer as in claim 1 together with means for determining which of said characters is to be printed and including means for skipping a print operation for one revolution of said rotatable wheel in response to said determining means indicating a change from a character in one helical path to a character in a predetermined other helical path.

Claim 10

A printer as in claim 8 where said determining means includes a counter which is preloaded with a number corresponding to the character to be printed and said skipping means inhibits operation of said counter for one revolution of said rotatable wheel.

Claim 11

A printer as in claim 1 including an ink roller mounted on a fixed longitudinal axis extending the length of the range of axial transverse movement of said rotatable wheel together with means for rotating said roller at a predetermined speed and together with means for coupling the periphery of said ink roller with the periphery said rotatable wheel whereby said rotatable wheel is rotated by said ink roller.

Claim 12

A printer as in claim 10 together with means for engaging and disengaging said rotatable wheel from said ink roller during axial movement of said rotatable wheel in one direction.

Claim 13

A printer as in claim 11 in which said engaging/disengaging means includes eccentric means mounted for rotary movement and coupled to carriage means on which said rotatable device is mounted for rotation for lifting said carriage and said rotatable wheel off of said ink roller.

Claim 14

A printer as in claim 1 where said rotatable wheel includes a slotted code cup having a number of clocking slots each corresponding to a character, one of said clocking slots being cut deeper than the remainder to serve as an index slot and together with two photodetectors and a juxtaposed light source between which said slots move, one of said photodetectors being positioned to be activated only by passage of said index slot and the other photodetector being positioned to be actuated by passage of said clock slots said one photodetector being located with respect to the other photodetector to be activated in a leading phase relationship.