Conveying Section – Feeder
To synchronize it with the iron plate conveyance of the coating machine/printing machine. The main settings are as follows:
(1) Setting Pressure Roller (Adjusting Roller Clearance)
① Start the feeder until the pressure roller shaft is at the highest point of the cam, and place a 3mm thick gauge between each pressure roller and the feed roller. Use a wrench to grip the lower adjustment nut and loosen the upper nut. Then adjust until the 3mm thick gauge is just snug. Tighten the lower adjustment nut with one wrench and tighten the upper nut with another. Double-check after locking.
② Start the feeder until the cam follower is at the lowest point of the cam (i.e., the pressure roller is at the lowest point). Check if the pressure roller is just making slight contact with the feed roller. Due to mechanical errors, the pressure may be slightly different on each side. If so, readjust the balance when the pressure roller just contacts the feed roller.
③ When loosening or tightening the two adjustment nuts, always use two wrenches to avoid breaking the bolt.
(2) Setting/Adjusting Camshaft Device – Front Suction Nozzle Shaft
① The reciprocating motion of the front suction nozzle shaft on the CRABTREE 1290 feeder is achieved through the camshaft device.
There are two sets of identical cams, camshafts, pivot shafts, and pivot arms (one set on the operating side of the camshaft, and the other set on the outer side of the machine). One set of cams moves the suction nozzle shaft forward, while the other set moves it backward. Note: There is no spring in this device to press the cam rod against the cam, so the smooth operation of the feeder depends on the correct gap setting between the cam and the cam rod.
② The correct gap between the cam rod and the matching cam is a minimum of 0.08mm (0.003in) and a maximum of 0.20mm (0.007in).
(3) Setting Valves (Nozzle Synchronization)
① On the feed camshaft on the operating side of the machine, there is a counterclockwise-rotating synchronized chain sprocket. The intake valve controlled by the piston is driven by an eccentric cam connected to the chain sprocket. There is a synchronizing disc on the synchronized chain sprocket, indicating the relative position and function of the iron sheet feeding cycle.
② When set correctly, as the leading edge of the iron sheet enters between the pressure roller and the feed roller, i.e., when the pressure roller just starts to close on the iron sheet, the front suction nozzle begins to release the iron sheet. The valve resetting steps are as follows: Note: Valve settings must be done at normal production speed; otherwise, errors may occur if jogging or speeds are below 2000 sheets/h.
(4) Adjust the feeder to synchronize with the iron plate conveyance of the coating machine/printing machine.
① The CRABTREE 1290 feeder is equipped with a differential gearbox called VARI-DRIVE.
The function of VARI-DRIVE is to synchronize the feeder with the speed of the coating machine or printing machine during machine operation. Adjustment of the small electric motor in the VARI-DRIVE system can change the differential to achieve synchronization.
② When the machine is running normally, adjust the feeding to the coating machine or printing machine so that the pusher and pushing chain smoothly push the iron sheet.
