GB1014639A - Silk screen printing apparatus - Google Patents

Abstract

1,014,639. Screen printing apparatus. M & M RESEARCH ENGINEERING Inc. Feb. 18, 1964 [Jan. 3, 1964], No. 6636/64. Heading B6C. A silk screen printing apparatus, comprises a frame F pivotally mounted at 4 for swinging between a horizontal printing position, Fig. 1, and an inclined inoperative position, Fig. 3, a squeegee and flood bar assembly 51, 57, 60, mounted through rollers 54, 55 on the frame for reciprocation therealong, two pivotal plates 64 and pin-and-slot connections 69a, 69, on said assembly for shifting the flood bar 60 relative to the squeegee 57, and drive means for reciprocating the assembly and moving the pivotably mounted plates 64 the drive means including a power driven rotatable member 70, a lever 71 pivotally mounted on the frame F, an arm 68 pivotally connecting the lever and one of the plates 64, and an intermediate link 74 pivotally connected between the lever and the member 70 whereby rotation of the member 70 swings the lever to cause the arm to operate the plate 64 prior to reciprocating the assembly. The drive to the member 70 derives from one end of a shaft 44 forming a double-ended output shaft of a gear reduction unit 42 driven from a motor 40 through a drive belt 41. The lever 71 is fixedly connected through a rotatable shaft 72 with a further lever 71 which also carries an arm 68 for connection to the other pivoted plate 64. The other end of the output shaft 44 carries a cam 49 for actuating a timing device 47 having a micro-switch 48 and a cam 43 for engagement with a roller 45 mounted on the base 1 of the apparatus. This latter cam effects the cyclic raising and lowering of the frame F relative to the printing table 2 whilst the timing device 47 controls the energization of the motor 40. The silk screen 38 is mounted in a wooden frame 21 which is loosely held in the frame F through adjustable screw-devices 28, 29 and 33, 32, 18. The sheets to be printed may be held on the table 2 by suction means (not shown). The operation of the machine derives from the automatic timer control of the device 47 on the motor 40 and it allows a period of dwell of the squeegee 57 and the flood bar 60 at both ends of their travel over the screen 38, that is, before the printing-cycle starts again, in order to give the frame F time to lower without forward printing motion of the squeegee 57 and consequent premature delivery of the printing ink through the screen, and also at the end of the printing stroke in order to give the screen time to be raised off the work and give the flood bar 60 time to contact the screen before the bar and squeegee commence their return stroke. The squeegee and flood bar assembly is about halfway through its return stroke before the frame F begins to lower.