Safety Clutch Pulley

The purpose of the safety clutch pulley (figure 4-4 [D]) is twofold. First, it is used to transfer the power and motion from the arm shaft connection belt to the hook-driving shaft; second, it protects the hook from being damaged by disengaging when the hook is jammed. To remove the safety 4-26 clutch pulley, you loosen the two setscrews (figure 4-6 [S]) that attach the safety clutch pulley to the hook-driving shaft and withdraw the pulley.

Feed-Lifting Eccentric

The feed-lifting eccentric (figure 4-6 [T]) supplies a lifting motion to the feed-lifting eccentric fork. Remove the feed-lifting eccentric by moving the hook-driving shaft to the right until it clears the feed-lifting eccentric, thus allowing the eccentric to drop from the shaft.

Hook-Driving Gear

The hook-driving gear converts the longitudinal motion in the hook-driving shaft to the horizontal motion on the sewing hook. Remove the hook-driving gear by moving the hook-driving shaft to the right until it clears the hook-driving gear, thus allowing the hook-driving gear to drop from the shaft.

Feed-Driving Eccentric

The feed-driving eccentric sets up the motion and controls the feeding mechanism of the sewing machine. Remove the feed-driving eccentric by moving the hook-driving shaft to the right until it clears the feed-driving eccentric, thus allowing it to drop from the shaft.

Feed-Driving Connection

The feed-driving connection carries the feeding motion to the feed-driving crank. Remove the feed-driving connection simultaneously with the feed-driving eccentric. Remove the connection from the eccentric by withdrawing it from the eccentric.

Feed-Driving Crank

The feed-driving crank transfers the feeding motion from the feed-driving connection to the feed-driving rockshaft. The feed-driving crank is attached to the feed-driving connection and is removed from the sewing machine when you remove the feed-driving connection.

Hook-Driving Shaft Lock Ratchet

The hook-driving shaft lock ratchet locks the hook-driving shaft in position while you set the safety clutch. Remove the hook-driving shaft

lock ratchet by moving the hook-driving shaft to the right until it clears the hook-driving shaft lock ratchet, thus allowing it to drop from the shaft.

Arm Shaft Connection Belt Timing Collar and Hook-Driving Shaft Ball-Bearing Collar

The arm shaft connection belt timing collar and the hook-driving shaft ball-bearing collar are the initial timing points on the machine. Do not remove these parts from the machine. In machines fitted with cast iron bushings, the timing collar will fall off as the shaft is withdrawn.

Hook-Driving Shaft

The hook-driving shaft (figure 4-6 [N]) transfers power and motion to the units attached to it. To remove the hook-driving shaft, you grasp it and withdraw it to the right.

Bobbin-Case Opener

The bobbin-case opener (figure 4-9 [D]) acts as a lever to pull the bobbin case back from the throat plate. It allows the needle thread to pass between the bobbin case and the throat plate. To remove the bobbin-case opener, you unscrew the adjusting screw (figure 4-9 [E]) and lift it from the hook saddle assembly.

Hook Saddle Screw

The hook saddle screw (figure 4-6 [B]) holds the hook saddle assembly in place. Unscrew the hook saddle screw to remove it.

Hook Saddle Assembly

The hook saddle assembly (figure 4-6 [U]) forms the lower half of the stitch. To remove the hook saddle assembly, unscrew the hook saddle screw and loosen the hook saddle pinch screw (figure 4-6 [A]). Draw the hook saddle assembly slightly toward the operator, slide it to the left until it clears the center hook-driving shaft bushing, and withdraw it from the machine. This completes the disassembly of the sewing machine.

REASSEMBLY

Before reassembling the sewing machine, you will need some grinding compound to smooth parts that may have surface rust or small burrs.

A small amount of grinding compound on the surface is sufficient. Rotate the two parts until they move freely. You will also need some 10W mineral oil to lubricate all moving parts. After you accomplish these tasks, proceed as follows to reassemble the sewing machine.

Hook Saddle Assembly

To replace the hook saddle assembly, hold it in an upright position with the saddle clamp facing the bed of the machine; then place the saddle clamp on the edge of the center hookdriving shaft bushing. Swing the hook saddle assembly toward the bed of the machine and slide it to the right and into place in the opening in the casting.

Hook Saddle Screw

With the hook saddle assembly as far to the right as it will go, replace the hook saddle screw and tighten it.

Bobbin-Case Opener

Lift the machine to the upright position. Replace the bobbin-case opener so that the curved end points toward the bobbin case. Replace the bobbin-case opener adjusting screw and tighten it.

Hook-Driving Shaft

Tilt the machine forward. In replacing the hook-driving shaft, you should note that it has five splined grooves. One of the splined grooves is located at one end of the shaft. Insert the end without a splined groove into the right hookdriving shaft bearing.

Hook-Driving Shaft Lock Ratchet

As the hook-driving shaft is pushed toward the left, or face, of the machine, replace the hookdriving shaft lock ratchet so that the flange with the setscrews faces the left of the machine.

Feed-Driving Connection and Feed-Driving Crank

Hold the feed-driving eccentric with the flange and spring to the right; then place the feed-driving connection, with the feed-driving crank attached, over the cam on the feed-driving eccentric. Be sure the oiling felt faces upward and the crank is toward the operator.

Feed-Driving Eccentric

Holding the feed-driving eccentric in the same manner as stated above, you replace it on the hook-driving shaft.

Hook-Driving Gear

Push the hook-driving shaft through the center hook-driving shaft bushing. Replace the hookdriving gear so that the flange with the setscrews is facing toward the left.

Feed-Lifting Eccentric

Place the feed-lifting eccentric on the hookdriving shaft and slide the hook-driving shaft into the front hook-driving shaft bushing, leaving approximately 2 inches of the hook-driving shaft extended to the right of the rear hook-driving shaft bushing.

Safety Clutch Pulley

Replace the safety clutch pulley so that the safety clutch hook-driving shaft stop collar, with the screws in it, is flush with the right end of the hook-driving shaft. Turn the safety clutch pulley until the spline screw marked with the letter S is positioned over the spline in the hook-driving shaft. Tighten the spline screw and the setscrew.

Feed-Driving Rockshaft

The cylinder end of the feed-driving rockshaft is placed from the left into the feed-driving rockshaft bushing. The flat side of the feeddriving rockshaft stop collar is placed flush with the bushing, and the rockshaft is moved forward to enter the stop collar. The feed-driving crank is placed next to the stop collar, and the rockshaft is moved forward to enter the crank. The remaining stop collar is placed on the rockshaft with the flat side to the right. The rockshaft (with the base of the feed bar toward the operator) is moved through and 1 inch past the right bushing. Holding the base of the feed bar toward you, rotate the rockshaft downward toward the bed of the machine and fit the feed dog into the throat plate.

Place the feed-lifting eccentric fork over the feed-lifting eccentric and fit the base of the feed bar into the slot at the top of the feed-lifting eccentric fork. When the feed-lifting eccentric fork is in position, the rounded end of the fork 4-28 will be facing you. To secure the feed-lifting eccentric fork to the feed dog, you must place the feed eccentric fork screw into the space provided and tighten it.

The feed-driving rockshaft crank is attached to the needlebar rock frame rockshaft crank and connection. To replace it, insert the needlebar rock frame rockshaft crank and connection with the curved portion upward and the crank hanging down into the arm through the opening in the bed of the machine. Slide the feed-driving rockshaft crank over the feed-driving rockshaft. Do not tighten the crank. Ensure all other screws are tight.

This completes the assembly of the parts in the bed of the machine. Now we will assemble the parts located in the arm of the machine.