The
Model 31

A Thin Self-Winder

The TIMEX Model 31 movement is a new thin self winding watch which uses the basic construction of the Model 24. A new planetary gear winding system located on the front frame provides a compact method of obtaining the necessary gear reduction between the self winding weight and the mainspring.

The reserve power of the mainspring when the watch is worn by a normally active person is sufficient to run the watch for a full day.

Timex found that the best method of cleaning is with only the sweep second hand, dial, mounting ring, planetary gear system and balance removed. The cleaning fluid, while removing any contamination from the movement, will also remove oil from the gear train, pivots and holes.

Exploded View

The list is word for word the Model 24 list plus the planetary winding parts.

Model 31 · 41 Components

Ref.Component

100Dial Plate Assembly

118Movement Plate Assembly

180/1Barrel Complete (with Mainspring)

201/1Second Wheel Assembly

210Third Wheel Assembly

227Seconds Wheel Assembly

242Cannon Pinion Assembly

255Hour Wheel

260Minute Wheel Assembly

401/1Winding Stem with Crown

423/1Rocking Bar Bushing

425Click

437Rocking Bar

443Setting Lever

450Setting Wheel

450/1Stem Wind Pinion

452Wind and Set Pinion

495/1Retaining Ring (Cap Jewel)

495/2Winding Bridge

495/3Winding Ratchet Wheel Lock Washer

498/1Hour Wheel Washer

704Escape Wheel Assembly

713Pallet Lever Assembly

721Balance Assembly

740Hairspring Wedge Pin

751Dial Assembly

816Balance Screw Assembly

850Hour Hand

851Minute Hand

852/1Sweep Second Hand

1130Rotor Plate Assembly

1142/1Mounting Ring

1409/1Ratchet Wheel

1481/1Planet Wind Pinion

1482/2Planet Pinion Assembly

1489Winding Ratchet Wheel Assembly

5100Pillar Screw

5443Set Lever Screw

51130Rotor Plate Screw

51142/1Mounting Ring Screw

51142/3Mounting Ring Screw

Disassembly for Cleaning

Removing the Dial and Hands

a

Remove the sweep second hand. Do not remove the hour or minute hand.

b

The dial is clamped to the movement mounting ring by four tabs protruding from the outside of the dial. Straighten these tabs as indicated by the arrow and dotted lines in the illustration and remove the entire assembly.

c

Once the dial assembly is off the movement there is no need for further dismantling of the dial assembly unless severe contamination is present on the friction and cannon pinions. Should further dismantling be required, removal of the minute hand will free the friction and cannon pinion assembly. The friction pinion is held in the cannon pinion by a snap fit.

Fig. 31.3 · Dial & Hands

Removing the Rotor

a

Invert the movement so that the movement plate is facing you and remove the two rotor frame screws.

b

Lift the rotor assembly slightly to free the dowels which position it. Since the rocker arm fits between the rotor frame and the rotor weight assembly, the rotor weight must be removed by sliding it along the movement plate until it is free of the rocker arm.

Caution: Any attempt to lift the weight before it is free of the rocker arm will result in damage to the movement.

Fig. 31.3 · Removing the Rotor

Removing the Mounting Ring

a

Before removal of the mounting ring, the mainspring power must be fully let down. Grasp the crown in the fingers of one hand and move the click out of engagement with the ratchet wheel. Let the crown revolve slowly in the fingers, being careful not to let the crown slip.

b

After letting the power of the mainspring down, remove the four mounting ring screws. Next remove the mounting ring ratchet wheel, planet pinion assembly and click.

Note: To disengage the click, hold the click spring back and turn the crown forward. The click will fall out of engagement.

Fig. 31.4 · Removing the Mounting Ring

Crown, Stem and Balance Wheel

a

For the crown and stem, proceed as directed on page 24.4 for the Model 24 movement.

b

For the balance wheel, proceed as directed on page 24.5 for the Model 24 movement.

Fig. 31.4 · Mounting Ring Screws

Cleaning & Lubrication

After disassembly of the sweep second hand, dial, rotor, mounting ring, planetary gear system, click and balance, the movement is ready to be cleaned. The same instructions for cleaning as given for the Model 24 movement apply to the Model 31. Care should be exercised to insure complete cleaning of all self winding parts.

The same reoiling instructions given for the Model 24 movement apply to the Model 31. In addition, all moving parts of the self winding and planetary gear system should be oiled.

Reassembly

Use the disassembly procedures for the Model 31 and 24 movements as a guide for reassembly. Reassembly procedures for the balance wheel, position of the hairspring and positioning of the sweep second hand are given on page 24.7.

Helpful Hints

1. Oiling. When oiling the movement plate balance cup, to facilitate the precise entry of the oil to the bottom of the cup, insert the oiler through the dial plate balance screw hole before the balance screw is assembled.
2. A drop of oil applied to both sides of the stem wind pinion before assembly will hold the pinion and its bridges together, thus facilitating assembly should complete dismantling of the movement be necessary.
3. Examine the action of the rotor on the winding frame. Be certain the staking is secure and that the rotor is free to make a complete revolution without interference. Check that the spring which holds the movement in the bezel is properly located in its groove.
4. Check the freeness of the rocker arm and the clicks which are attached to it. Check that the yoke of the rocker arm slides freely on the cam attached to the self-wind weight without interference.
5. Check the action of the winding ratchet wheel. Each rotation of the rotor should move this wheel forward approximately 6 teeth.
6. Check the action of the mainspring and the barrel. The mainspring should have 5 to 6 full turns before the sliding tail begins to revolve in the barrel.

Parts