Dual Grasshopper 

 

Specifications:

 

Height:    87.5”    2.14M

Width:     13”       330mm

Depth:     8.5”     216mm

 

Details

 

ESCAPEMENT

 

The escapement is a unique adaptation of John Harrisons Grasshopper geometry. In addition to its sculptural layout the rationale behind the escapement is based on mitigation of a variable torques provided by the two pallets in the original configuration. In Harrisons original geometry the pallets are of differing lengths and therefore differing moment arms. In the Dual Escapement the pallets are mirrors of each other hence elimination of the variable torques and impulse delivery to the pendulum. 

 

Unlike many other escapements its sound is very unobtrusive making it ideal for a domestic environment.  

 

TRAIN

 

The clock is driven by a Wagner type remontoire hidden within the back board.  ‘Winding’ occurs every few seconds providing uniform power to the gear train.  Power for winding is provided by a 6v cell. This provides uninterrupted power in the event of a mains power failure. The rechargeable cell is expected to last 2+ years and is located in the base of the clock.  

 

The single centre wheel tooth profile and escape wheel roller pinion are derived using Harrison’s Chordal Pitch.  Harrison created Chordal Pitch gearing to work with the Grasshopper escapements significant recoil. Typically clockmakers use Cycloidal Pitch profiles in clock trains however this type of profile does not work well with escapements having significant recoil. 

 

PENDULUM

 

The pendulum beats 4.5 degrees, a little less than the typical grasshopper owing to its modified geometry. Invar is used in the pendulum assembly. Invar is an alloy frequently used in Horology owing to its thermal stability. Rough regulation is achieved directly on the pendulum bob. Fine regulation is achieved via the subsidiary weights above the bob. Beat setting adjustment is provided at the crutch. 

 

DIALS

 

The dial is of the regulator style and displays dual time zones. Time zone locations adjusted to suit clients wishes. 

 

Seconds are read directly on the left escape wheel using the pallet as the indicator. Owing to the large recoil inherent in the Grasshopper escapement this arrangement provides a sure reading of the seconds rather than an oscillating second hand as would be the case if a traditional hand on a seconds chapter was used. 

 

CASE

 

Full length frameless tempered glass. 

12V LED lighting

 

PRICE: Please contact 

The clock is provided with a custom made shipping case.

Delivery, personal attendance, setup and instruction included