Bifurcated Suspension

The Suspension System applicable to vibration dampening, providing variable, active, adjustable, and programmable spring rates.

Patent Number 7789378

Patent Abstract:

A spring system comprising flat plate-springs with one end mounted rigidly to an un-sprung first base and the opposite end mounted rigidly to a sprung second base. The spring system is fitted with cams as strain-control surfaces, mounted tangent to the plate springs and spaced progressively from the said plate-springs beginning at the tangency. The strain-control cams are movable to provide for adjustable spring rates, actively repositioned upon demand therein providing an adaptive active spring-rate system or suspension. 


This bifurcated spring system provides the basis designs of suspensions with the following inherent characteristics:


  • Rigid mounting of plate-springs to both the sprung and un-sprung portion of the mass or vehicle  (Pivot-less suspension)  
  • Inherent unidirectional suspension travel without other suspension path control mechanisms
  • Variable spring rate - adjustable linear or progressive as well as progressively adjustable for adaptive active suspension
  • Friction dampening
  • Zero stiction 
  • Low parts count
  • Small envelope
  • Low weight
  • Simple design

Products utilizing this innovative suspension system available now include:

- Bike Stem Suspension - Designed for Road Bikes and Commuter Bikes

- Full-Suspension Mountain Bike Frames

See Bike Application Photo Gallery

Proof of Concept Demonstration

demo fixture


Cam 0 Load 0

Fig. 1 - Spring-Support Cam (SPC) Set: 0mm  Load: 0 Suspension Level: 0

Cam 100 Load 0

Fig. 2 - SPC: 15mm  Load: 0  Level: 0

Cam 0 Load 3

Fig. 3 - SPC: 0  Load: 3  Level: 3

Cam 100 Load 3

Fig. 4 - SPC: 15mm  Load: 3  Level: 1.5

Cam 0 Load 6

Fig. 5 - SPC: 0  Load: 6  Level: 5

Cam 100 Load 6

Fig. 6 - SPC: 15mm  Load: 6  Level: 2.5

NOTE: Extending the 4 cams on this fixture 15mm doubles the load capacity.

Dittmar Development LLC - 4970 N Manufacturing Way Ste 1, Coeur d' Alene, ID 83815  (208) 664-1020