Screen printer with screen length and snap-off angle control
OwnerOozeki Masanaoinventor
Life of this patent
Estimating the term…
Abstract
An improved screen printing machine includes a screen held over a surface to be printed, a squeegee, and a drive assembly which moves at least one end of the screen along a locus that enables substantially uniform maintenance of the length of the screen as well as the snap-off angle formed between the screen and the plane of the surface on the side of the squeegee opposite to where the squeegee carries its inking edge at the lower end thereof so as to provide substantially no dimensional deviation from the original and with enhanced uniformity in the thickness of the ink that is transferred.
Claims6
An improved screen printing machine comprising:
- a screen held over a surface to be printed, said screen having a first fixed end and a second end,
- a squeegee having an inking edge at a lower end thereof and in contact with said screen for transferring ink to said screen, and
- drive means for moving said second end of said screen in unison with said squeegee on said screen along a locus substantially of a hyperbola so that:
- (a) the length of said screen is maintained substantially constant throughout said movement, and
- (b) a snap-off angle formed between the screen and the surface, on one side of the squeegee at a position opposite to the inking edge of the squeegee, is maintained substantially constant throughout the entire movement of said squeegee for ink transfer.
An improved screen printing machine comprising:
- a screen held over a surface to be printed, said screen having a first moveable end and a second fixed end,
- a squeegee having an inking edge at a lower end thereof andin contact with said screen for transferring ink to said creen, and
- drive means for moving said first moveable end in unison with said squeegee on said screen along a locus substantially of a hyperbola so that:
- (a) the length of said screen is maintained substantially constant throughout said movement, and
- (b) a snap-off angle formed between the screen and the surface, on one side of the squeegee at a position opposite to the inking edge of the squeegee, is maintained substantially constant throughout the entire movement of said squeegee for ink transfer;
- said drive means moving said first moveable end of said screen along a locus that is at least in close approximation with a theoretical locus determined to have its loci at L sin (.alpha./2+.pi./4).+-..sqroot.sin.S and -L cos (.alpha./2+.pi./4) and its asymptotic lines at an angle at 45.degree. with respect to the origin of coordinates L sin (.alpha./2+.pi./4) and -L cos (.alpha./2+.pi./4), where L is the overall length of said screen, .alpha. is the snap-off angle and the fixed second end of said screen is at (O, S) in the same coordinate system.
An improved screen printing machine comprising:
- a screen held over a surface to be printed, said screen having a first moveable end and a second fixed end,
- a squeegee having an inking edge at a lower end thereof and in contact with said screen for transferring ink to said screen, and
- drive means for moving said first moveable end in unison with said squeegee on said screen along a locus of a straight line so that:
- (a) the length of said screen is maintained substantially constant throughout said movement, and
- (b) a snap-off angle formed between the screen and the surface, on one side of the squeegee at a position opposite to the inking edge of the squeegee, is maintained substantially constant throughout the entire movement of said squeegee for ink transfer;
- said drive means including a moveably disposed holder means for moving said first end of said screen along the locus that is a straight line and inwardly and upwardly inclined through an angle equal to one-half said snap-off angle with respect to a vertical to the path of movement of said squeegee.
Dependencies are inferred from the claim text.