US 6,186,622 B1Granted

Low expansion snout insert for inkjet print cartridge

AssigneeHewlett-Packard Company

InventorsAndré Garcia, Steven W. Steinfield

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Abstract

Described herein is a snout insert, referred to as an exapander, which is pressed fit into the snout of a plastic inkjet print cartridge. The expander has a low coefficient of thermal expansion (CTE) and a high tensile modulus relative to the print cartridge body. The expander reduces the CTE of the snout to be closer to, or less than, the CTE of the nozzle member, such as a TAB head assembly, to reduce or prevent warpage of the nozzle member due to thermal cycling of the print cartridge during the manufacturing process. The nozzle member is then fixed to the snout. The expander is designed for a precise fit into the snout and, in one embodiment, includes machinable datums to ensure a tight fit. In one embodiment, the expander is inserted through the ink reservoir area in the print cartridge body and pushed into the snout.

Claims20

Dependent claims

An apparatus for printing comprising:

a nozzle member having a plurality of ink orifices formed therein, said nozzle member being formed of a first material having a first coefficient of thermal expansion;
a body having a snout portion, said snout portion having a first end and a second end and including a plurality of tapered walls tapering from the second end to the first end, wherein said nozzle member is fixed to the first end of said snout portion, said body being formed of a second material having a second coefficient of thermal expansion substantially higher than the first coefficient of thermal expansion;
and
an expander press-fit into the second end of said snout portion to prevent substantial relative displacement therebetween, said expander being formed of a third material having a third coefficient of thermal expansion substantially lower than said second coefficient of thermal expansion, wherein said expander limits contraction of the first end of said snout portion such that the coefficient of thermal expansion of the first end of said snout portion is substantially less than said second coefficient of thermal expansion, a resulting coefficient of thermal expansion of the first end of said snout portion with said expander inserted therein being closer to, or less than, said first coefficient of thermal expansion of said nozzle member, said expander thereby substantially reducing deformation of said nozzle member due to thermal expansion of said body.

1 more element

A method of sealing a nozzle member in an inkjet printhead with respect to a snout portion of a body and reducing thermally induced stress between the nozzle member and the snout portion, said nozzle member being formed of a first material having a first coefficient of thermal expansion, said snout portion being formed of a second material having a second coefficient of thermal expansion substantially higher than said first coefficient of thermal expansion, said snout portion having a first end and a second end, the first end being adapted to receive said nozzle member, said method comprising:

press-fitting an expander into said snout portion from the second end, said expander being formed of a third material having a third coefficient of thermal expansion substantially lower than said second coefficient of thermal expansion, wherein said expander limits contraction of the first end of said snout portion to prevent substantial relative deformation therebetween and to cause the coefficient of thermal expansion of the first end of said snout portion to be substantially less than said second coefficient of thermal expansion;
and
fixing said nozzle member to the first end of said snout portion of said body with an adhesive, wherein a resulting coefficient of thermal expansion of said snout portion, after insertion of said expander, is closer to, or less than, said first coefficient of thermal expansion of said nozzle member, thereby substantially reducing deformation of said nozzle member due to thermal expansion of said body.

Dependencies are inferred from the claim text.