Mosaic printing head

Claim 2

A mosaic printing head, comprising in combination: a plurality of printing rods; a base member; a corresponding plurality of electromagnets secured on said base member and arranged for driving said printing rods on a one-toone basis, said electromagnets having armatures with exposed outer ends; a mouthpiece for guiding said printing rods at their printing ends, the other ends of said printing rods being fixedly connected to said armatures of said electromagnets, the length from the printing end of the printing rod to the outer end of the corresponding armature being equal for all printing rods; means defining a single, common abutment plate fixed with respect to and spaced from said base member and opposed to and engaging the outer ends of all said armatures for simultaneously determining, without intervening individually positionable means, the initial position of the plurality of printing rods, said armatures and said printing rods fixed thereto extending convergently from said common abutment plate, said abutment plate being curved and being a portion of a substantially spherical cup, said abutment plate extending transversely and continuously between and past all said outer armature ends, said abutment plate being formed and located such that the stroke length is equal for all said printing rods, whereby to eliminate the need for individual adjustment of the initial position and length of the printing rods.

Claim 3

A mosaic printing head, comprising in combination: a plurality of printing rods; a corresponding plurality of electromagnets arranged for driving said printing rods on a one-to-one basis, said electromagnets having armatures; a mouthpiece for guiding said printing rods at their printing ends, the other ends of said printing rods being fixedly connected to said armatures of said electromagnets, the length from the printing end of the printing rod to the outer end of the corresponding armature being equal for all printing rods; a common abutment plate opposed to and engageable by the outer ends of all said armatures and simultaneously determining the initial position of the plurality of printing rods, said abutment plate being formed and located such that the stroke length is equal for all said printing rods, whereby to eliminate the need for individual adjustment of the initial position and length of the printing rods, said electromagnets each including a magnetic core, the ends of the magnetic cores of the electromagnets cooperating with the adjacent ends of the armatures to form in each case a space into which the armature is movable; a heat conducting base member spaced intermediate said mouthpiece and abutment plate, webs extending from said abutment plate to said base member for fastening the abutment plate to the base member, the base member and abutment plate being correspondingly curved, said cores being pressed into said base member and extending radially therefrom toward said abutment plate, said electromagnets each including a coil, each said coil being fixed on its corresponding core and spaced axially from said base member and abutment plate.

Claim 4

A mosaic printing head, comprising in combination: a plurality of printing rods; a corresponding plurality of electromagnets arranged for driving said printing rods on a one-to-one basis, said electromagnets having armatures; a mouthpiece for guiding said printing rods at their printing ends, the other ends of said printing rods being fixedly connected to said armatures of said electromagnets, the length from the printing end of the printing rod to the outer end of the corresponding armature being equal for all printing rods; a common abutment plate opposed to and engageable by the outer ends of all said armatures and simultaneously determining the initial position of the plurality of printing rods, said abutment plate being formed and located such that the stroke length is equal for all said printing rods, whereby to eliminate the need for individual adjustment of the initial position and length of the printing rods, said electromagnets each including a magnetic core, the ends of the magnetic cores of the electromagnets cooperating with the adjacent ends of the armatures to form in each case a space into which the armature is movable; a heat conducting base member spaced intermediate said mouthpiece and abutment plate, webs extending from said abutment plate to said base member for fastening the abutment plate to the base member, the base member and abutment plate being correspondingly curved, said cores being pressed into said base member and extending radially therefrom toward said abutment plate, said electromagnets each including a coil, each said coil being fixed on its corresponding core and spaced axially from said base member and abutment plate.

Claim 5

A printing head according to claim 2 in which the armatures and the printing rods fixed thereto extend convergently from the common abutment plate, the curvature of said abutment plate corresponding to such convergence of said armatures, said abutment plate extending transversely between and past said outer armature ends.

Claim 6

A printing head according to claim 2, in which said magnetic cores being spaced from the abutment plate by a common distance, the sum of stroke length and armature length for each armature being equal to said common distance.

Claim 7

A printing head according to claim 4, in which said common abutment plate is a portion of a substantially spherical cup.

Claim 8

A printing head according to claim 2, including a base member of heat-conducting material, the electromagnets being secured to said base member, and further including a guide member of low friction material positioned in front of and releasably connected to said base member for guiding said printing rods, said mouthpiece being spaced in front of said guide member for defining a gap therebetween.

Claim 9

A printing head according to claim 6, in which the electromagnets each include a magnetic core secured on the base member, said abutment plate being secured to said base member in spaced relation thereto and to said cores.

Claim 10

A printing head according to claim 6, including a removable housing having separable opposed parts fixable with respect to said base member in surrounding relation to said printing head, said mouthpiece and guide member being perimetically surrounded and held in place by said housing.