Printer head assembly

Claim 2

A printer head assembly for use in printers of the dot-matrix type comprising: a housing having front and rear vertical walls and side walls joining said front and rear walls; the width of said front wall being smaller than the width of said rear wall whereby said side walls form a configuration which tapers from rear to front; said rear wall having a plurality of apertures; a plurality of wire driving means each having a forward end mounted in an associated one of said apertures; said front wall having a central opening; a jewel bearing being mounted in said opening and having a plurality of small apertures arranged to lie along an imaginary straight line; a plurality of thin elongated print wires each having their rearward ends coupled to an associated one of said wire driving means; each of said print wires extending through the interior of said housing and having their forward ends positioned within one of said small apertures; the exterior surface of said rear wall having a central surface portion and a plurality of bevelled surface portions surrounding said central surface portion; said central surface portion being substantially perpendicular to the longitudinal axis of said housing; said bevelled surface portions being aligned transverse to said housing longitudinal axis; each of said apertures in said rear wall being provided in one of said rear wall surface portions such that said surface portions determine the alignment of said driving means whereby all of said driving means mounted within openings in said bevelled surface portions are aligned transverse to said housing longitudinal axis and the driving means mounted within the opening provided in the central surface is substantially in alignment with the housing longitudinal axis; each of said driving means being comprised of means for driving its associated print wire in a forward direction during a printing operation and for driving its associated print wire in a rearward direction upon completion of a print operation.

Claim 3

The assembly of claim 1 further comprising a support plate mounted within said housing intermediate said front and rear walls and having a plurality of openings; rigid elongated wire guides each being mounted within an associated opening in said plate for receiving and guiding the intermediate portion of an associated print wire extending between said front and rear walls to limit the amount of bending experienced by said print wires during operation thereof.

Claim 4

The assembly of claim 1 further comprising a pair of support plates mounted in spaced parallel fashion within said housing intermediate said front and rear walls each having a plurality of openings; rigid elongated wire guides each being mounted within a pair of associated openings in said plate for receiving and guiding the intermediate portion of an associated print wire extending between said front and rear walls to limit the amount of bending experienced by said print wires during operation thereof.

Claim 5

The assembly of claim 1 wherein said jewel bearing is comprised of a pair of bearing members each having a plurality of semicircular shaped grooves along one of its edges; said pair of bearing members being arranged side-by-side in said front wall opening with the edges containing said semicircular grooves abutting one another to co-operatively form said small apertures.

Claim 6

The assembly of claim 4 wherein the opening in said front wall receiving said jewel bearing members is wider than the total width of said members; resilient spring means being positioneD between one side of said opening and one of said bearing members for urging said members into engagement with one another to facilitate initial alignment of said bearing members.

Claim 7

The assembly of claim 5 wherein at least one of said bearing members is joined to said front wall by an epoxy.

Claim 8

The assembly of claim 1 further comprising snap-on cover means for sealing the top of said housing; said cover being formed of a resilient material and having a top surface and downwardly depending side walls positioned upon said housing side walls; said cover side walls having inwardly directed flanges along their free ends for embracing the marginal portion of the base of said housing.

Claim 9

A printer head assembly for use in printers of the dot-matrix type comprising: a housing having front and rear vertical walls and side walls joining said front and rear walls; the width of said front wall being smaller than the width of said rear wall whereby said side walls form a configuration which tapers from rear to front; said rear wall having a plurality of apertures; a plurality of wire driving means each having a forward end mounted in an associated one of said apertures; said front wall having a central opening; a jewel bearing being mounted in said opening and having a plurality of small apertures arranged to lie along an imaginary straight line; a plurality of thin elongated print wires each having their rearward ends coupled to an associated one of said wire driving means; each of said print wires extending through the interior of said housing and having their forward ends positioned within one of said small apertures; the exterior surface of said rear wall having a central surface portion and a plurality of bevelled surface portions surrounding said central surface portion; said central surface portion being substantially perpendicular to the longitudinal axis of said housing; said bevelled surface portions being aligned transverse to said housing longitudinal axis; each of said apertures in said rear wall being provided in one of said rear wall surface portions such that said surface portions determine the alignment of said driving means whereby all of said driving means mounted within openings in said bevelled surface portions are aligned transverse to said housing longitudinal axis and the driving means mounted within the opening provided in the central surface is substantially in alignment with the housing longitudinal axis; each of said driving means being comprised of means for driving its associated print wire in a forward direction during a printing operation and for driving its associated print wire in a rearward direction upon completion of a print operation; each of said driving means being comprised of: a housing having a central opening extending from the front to the rear of said housing; a hollow annular shaped opening surrounding a rearward portion of said central opening; an annular shaped coil assembly being positioned within said annular shaped opening and surrounding the rearward portion of said central opening; a cylindrical shaped armature being positioned for reciprocating movement within the rearward portion of said central opening so that at least a portion of said armature is surrounded by said coil assembly; the rearward portion of each of said print wires extending into the central opening of an associated one of said driving means; the forward end of each armature being joined to the rear end of an associated one of said print wires; a circular shaped biasing member being secured to the rearward end of said armature; a circular shaped end cap threadedly engaging the marginal exterior surface of said housing adjacent the rear end thereof; said biasing member being positioned between the interior surface of said end cap and the edge of said housing forming the outer wall of said annular shaped opening; the rear end of The hollow cylindrical section of said housing which separates said central opening from said annular shaped opening being a spaced distance from the adjacent end of said armature to enable said biasing member to experience flexing when said coil assembly is energized to move said armature in the forward direction; said biasing member normally urging said armature in the rearward direction when said coil assembly is deenergized.

Claim 10

A printer head assembly for use in printers of the dot-matrix type comprising: a housing having front and rear vertical walls and side walls joining said front and rear walls; the width of said front wall being smaller than the width of said rear wall whereby said side walls form a configuration which tapers from rear to front; said rear wall having a plurality of apertures; a plurality of wire driving means each having a forward end mounted in an associated one of said apertures; said front wall having a central opening; a jewel bearing being mounted in said opening and having a plurality of small apertures arranged to lie along an imaginary straight line; a plurality of thin elongated print wires each having their rearward ends coupled to an associated one of said wire driving means; each of said print wires extending through the interior of said housing and having their forward ends positioned within one of said small apertures; the exterior surface of said rear wall having a central surface portion and a plurality of bevelled surface portions surrounding said central surface portion; said central surface portion being substantially perpendicular to the longitudinal axis of said housing; said bevelled surface portions being aligned transverse to said housing longitudinal axis; each of said apertures in said rear wall being provided in one of said rear wall surface portions such that said surface portions determine the alignment of said driving means whereby all of said driving means mounted within openings in said bevelled surface portions are aligned transverse to said housing longitudinal axis and the driving means mounted within the opening provided in the central surface is substantially in alignment with the housing longitudinal axis; each of said driving means being comprised of means for driving its associated print wire in a forward direction during a printing operation and for driving its associated print wire in a rearward direction upon completion of a print operation; each of said driving means being comprised of: a housing having a central opening extending from the front to the rear of said housing; a hollow annular shaped opening surrounding a rearward portion of said central opening; an annular shaped coil assembly being positioned within said annular shaped opening and surrounding the rearward portion of said central opening; a cylindrical shaped armature being positioned for reciprocating movement within the rearward portion of said central opening so that at least a portion of said armature is surrounded by said coil assembly; the rearward portion of each of said print wires extending into the central opening of an associated one of said driving means; the forward end of each armature being joined to the rear end of an associated one of said print wires; a circular shaped biasing member being secured to the rearward end of said armature; a circular shaped end cap threadedly engaging the marginal exterior surface of said housing adjacent the rear end thereof; said biasing member being positioned between the interior surface of said end cap and the edge of said housing forming the outer wall of said annular shaped opening; the rear end of The hollow cylindrical section of said housing which separates said central opening from said annular shaped opening being a spaced distance from the adjacent end of said armature to enable said biasing member to experience flexing when said coil assembly is energized to move said armature in the forward direction; said biasing member normally urging said armature in the rearward direction when said coil assembly is deenergized.