Partial C40B WT on eBay.

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An interesting WT came up on eBay[UK] but unfortunately it lacked some important parts. Fortunately the parts which are most difficult to reproduce are still there.

All of these images have been copied from the eBay[UK] auction of early April 2017 for educational purposes.

1] General view of the WT movement including pendulum bob.

The large, drive electromagnets are missing in the open space at bottom right.

As is the ratchet, gathering wheel on its arbor with the vitally important drive worm.

2] General view. The rectangular frame of the gathering pallet is present but no ratchet wheel to drive. The ratchet wheel must have a longer tooth and a D-pin to lift the masking pawl clear.

 3] General view with upper pendulum rod and gathering pallet in the foreground.

The upper pendulum rod with its support bearings are present.

The masking pawl is absent. As are the Hipp toggle and V-block which control the contacts.

Two pale patches can be seen on the pendulum rod where once a cranked plate was fixed to support the Hipp toggle.

4] End view, including bob,pendulum rod and relay armature.

I believe the loose piece arranged in the middle is the relay magnet armature.

5] Rear view showing large wormwheel.

The bevel wheel is but one of four missing wheels.

These would each drive a pair of hands on the dials mounted on the sides of a clock tower or perhaps a church.

 6] Rear view with close-up of relay solenoid.

The relay electromagnet restarts the drive to the clock hands at each half minute by releasing the locking lever and masking pawl. This would allow an accurate master clock to maintain the WT to a similarly high, timekeeping standard. 

7] Front view showing rocking drive armature at bottom right. A roller attached to the top of the armature rises and impulses the projecting pendulum ramp, on demand, from the Hipp toggle & V-block switch.

The complete contact mechanism is also absent.

8]  The backstop pawl is present but not the ratchet wheel which it should rest against.

The L-shaped locking lever is also missing.
This would be lifted into the locking position by the D-shaped pin on the ratchet wheel.

The bearing plate to support the end of the ratchet wheel and worm arbor is present.

9] A closer view of the wormwheel and relay [timekeeping] electromagnet.

A small plate should rise up from the casting to provide a bearing for the relay electromagnet.

10] The large gap in the movement's main casting where the twin drive electromagnets would sit. When ever the pendulum swing reduced below optimum the electromagnets would be briefly switched on by the Hipp toggle catching in in its V-block.

11] General rear view. One wonders what carelessness led to all the missing parts?

A substantial, historical presence is spoilt by the missing pieces. It will be quite a daunting task to return it to its former glory. 

I have appended an image of a complete movement of matching type below for comparison.

A similar, almost complete  movement which was also auctioned on eBay[UK].

The apparent simplicity masks a work of genius which completely revolutionised turret clock design.The moment the WT movement was conceived all new weight driven clocks became obsolete.

The WT went on to set many records for the sheer size of the clock dials they could manage with a high degree of accuracy and reliability. Not to mention a lack of weekly winding nor constant and expensive maintenance.

Click on any image for an enlargement.

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