Print head assembly containing solenoids

Claim 2

A solenoid assembly comprising: a hollow case; a stem having an axial aligned opening of small diameter extending the length of said stem; said stem having a flange intermediate its ends secured to the forward end of said case and having its rearward portion extending into the interior of said case; an annular shaped coil positioned within said case and surrounding a portion of said stem; a threaded cap threadedly engaging the rearward end of said case; said cap having a projection extending into said case; an armature positioned within said case and along the axis of said case, at least the forward portion of said armature extending into the rearward portion of said coil; a slender print wire positioned within the axial opening of said stem and having its forward end extending beyond the forward end of said stem and its rearward end secured to the forward end of said armature; circular shaped spring means having its central portion secured to the rearward portion of said armature; the projection of said cap abutting against the rearward portion of said armature and being adjustable to adjust the pre-loading of said spring; said case having an annular shoulder engaging the periphery of said spring; said spring being formed of a resilient metallic sheet and having a circular central portion; a plurality of radially aligned portions each being integrally joined to and extending outwardly from said central portion; the outer ends of each radially aligned portion having a pair of arcuate shaped ears extending from opposite sides of said radially aligned portions; 16 the free end of each ear being a spaced distance from the free end of an adjacent ear whereby all of said ears define a circular shaped periphery whose marginal portion abuts against said annular shoulder.

Claim 3

The solenoid assembly of claim 1 wherein said spring is formed from a sheet of spring steel.

Claim 4

The solenoid assembly of claim 1 wherein said spring is adapted to exert a rearwardly directed force on said armature to normally hold said print wire in the non-impact position when said solenoid coil is deenergized, said coil being adapted to overcome the rearward directed force of said spring when energized to rapidly move said print wire toward the impact position, and thereby flex said spring to cause said print wire to return rapidly to the non-impact position when said coil is deenergized while reducing bounce and overshooting of said armature.

Claim 5

A print head assembly comprising: a housing having a rear wall and a front wall joined by a pair of side walls; a plurality of solenoid assemblies each comprising: a hollow case; a stem having an axial aligned opening of small diameter extending the length of said stem; said stem having a flange intermediate its ends secured to the forward end of said case and having its rearward portion extending into the interior of said case; an annular shaped coil positioned within said case and surrounding a portion of said stem; a threaded cap threadedly engaging the rearward end of said case; said cap having a projection extending into said case; an armature positioned within said case and along the axis of said case, at least the forward portion of said armature extending into the rearward portion of said coil; a slender print wire positioned within the axial opening of said stem and having its forward end extending beyond the forward end of said stem and its rearward end secured to the forward end of said armature; circular shaped spring means having its central portion secured to the rearward portion of said armature; the projection of said cap abutting agaInst the rearward portion of said armature and being adjustable to adjust the preloading of said spring; said case having an annular shoulder engaging the periphery of said spring; said spring being formed of a resilient metallic sheet and having a circular central portion; a plurality of radially aligned portions each being integrally joined to and extending outwardly from said central portion; the outer ends of each radially aligned portion having a pair of arcuate shaped ears extending from opposite sides of said radially aligned portions; the free end of each ear being a spaced distance from the free end of an adjacent ear whereby all of said ears define a circular shaped periphery whose marginal portion abuts against said annular shoulder; said rear wall having a plurality of openings for mounting said solenoids to said rear wall; said print wires extending through said rear wall and between said side walls toward said front wall; said front wall having openings each adapted to receive the free end of an associated one of said print wires; said front wall openings being arranged to be along a straight line; said rear wall openings being aligned with their axes generally converging toward said front wall.

Claim 6

A print head assembly comprising: a housing having a rear wall and a front wall joined by a pair of side walls; a plurality of solenoid assemblies each comprising: a hollow case; a stem having an axial aligned opening of small diameter extending the length of said stem; said stem having a flange intermediate its ends secured to the forward end of said case and having its rearward portion extending into the interior of said case; an annular shaped coil positioned within said case and surrounding a portion of said stem; a threaded cap threadedly engaging the rearward end of said case; said cap having a projection extending into said case; an armature positioned within said case and along the axis of said case, at least the forward portion of said armature extending into the rearward portion of said coil; a slender print wire positioned within the axial opening of said stem and having its forward end extending beyond the forward end of said stem and its rearward end secured to the forward end of said armature; circular shaped spring means having its central portion secured to the rearward portion of said armature; the projection of said cap abutting agaInst the rearward portion of said armature and being adjustable to adjust the preloading of said spring; said case having an annular shoulder engaging the periphery of said spring; said spring being formed of a resilient metallic sheet and having a circular central portion; a plurality of radially aligned portions each being integrally joined to and extending outwardly from said central portion; the outer ends of each radially aligned portion having a pair of arcuate shaped ears extending from opposite sides of said radially aligned portions; the free end of each ear being a spaced distance from the free end of an adjacent ear whereby all of said ears define a circular shaped periphery whose marginal portion abuts against said annular shoulder; said rear wall having a plurality of openings for mounting said solenoids to said rear wall; said print wires extending through said rear wall and between said side walls toward said front wall; said front wall having openings each adapted to receive the free end of an associated one of said print wires; said front wall openings being arranged to be along a straight line; said rear wall openings being aligned with their axes generally converging toward said front wall.

Claim 7

The assembly of claim further comprising a stationary elongated strip having a plurality of spaced transparent openings along said strip; said assembly being movable along a line parallel to said strip; a light source mounted upon said housing and being positioned on one side of said strip; light sensitive means being mounted upon said housing and being positioned along the opposite side of said strip so as to sense light emitted from said light source when said light source passes a transparent opening for generating a pulse to control the energization of said solenoids only upon passing one of said transparent openings.

Claim 8

The assembly of claim 5 wherein said light sensitive means comprises a photo head mounted immediately adjacent said opposite side of said strip and secured to said housing; a photocell secured to said housing; a fiber optic bundle coupled between said photo head and said photocell to pass light from said light source impinging upon said photo head to said photo cell.