Flat Fusee Rocket Axial Wire Winding for Compact Watch Movements
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Solution Overview
Problem
Existing watch movements with fusees face challenges in compact design due to the conical shape of traditional rockets, which restricts the slope of the cone and affects the efficiency of force compensation as the spring power reserve depletes, leading to inaccuracies in timekeeping.
Innovation Solution
A watch movement design featuring a flat rocket with a winding roller slidably mounted on a fixed guide parallel to the spindle axis, allowing the wire to wind and unwind perpendicular to the axis of rotation, and using a fine wire with a spiral groove on the rocket to compensate for decreasing spring force, reducing the height and size of the rocket.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional conical rocket is used in a fusee mechanism, then the spring force variation can be compensated, but the height and size of the rocket increase
Solution Approach 1:
The patent changes the winding direction from perpendicular to the axis (traditional conical design) to parallel to the axis. The wire now winds along the axial direction rather than wrapping around the cone surface, fundamentally changing the spatial dimension of the winding path. This allows the rocket to achieve the same force compensation function with a much reduced height, transforming a three-dimensional conical winding path into a more compact axial winding path.
Solution Approach 2:
The patent modifies the geometric parameters of the rocket by eliminating the conical shape and using a cylindrical form with axial winding. The slope angle parameter is changed from a minimum threshold (in traditional design) to effectively zero (in axial winding design). This parameter change enables the rocket to maintain its force compensation function while significantly reducing its height dimension.
2Length of moving object
If the cone slope is reduced to make the rocket more compact, then the height decreases, but the wire winding direction becomes difficult to maintain perpendicular to the axis
Solution Approach 1:
Instead of trying to maintain the traditional perpendicular winding direction while reducing cone slope (which creates manufacturing difficulties), the patent inverts the approach by making the winding direction parallel to the axis. This inversion of the winding direction resolves the manufacturing difficulty while achieving compact dimensions, as axial winding is mechanically simpler to implement and control.
3Length of moving object
If a flat rocket with axial winding is used, then the rocket size is reduced, but the wire must wind parallel to the axis instead of perpendicular
Solution Approach 1:
The patent accepts and utilizes the dimensional change in winding geometry as a solution rather than a compromise. By transitioning from perpendicular (radial) winding to parallel (axial) winding, the patent achieves compact rocket dimensions. The cylindrical shape with axial winding creates a different but equally effective geometric configuration that accomplishes the force compensation function in a space-efficient manner.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design maintains accurate timekeeping by effectively compensating for the reduction in spring force, allowing for a more compact and efficient watch movement without the constraints of a minimum cone slope, thereby improving the power reserve and reducing the size of the rocket.
Implementation Method 1
a wire (106) stretched between the barrel and the fusee so as to transmit the rotation of the barrel to the fusee and vice versa
Implementation Method 2
a wire (106) stretched between the barrel and the fusee
Implementation Method 3
a spiral groove (148) in which the wire (106) is arranged to wind and unwind
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The watch movement comprises a mainspring barrel (102), a fusee (104) having a main surface with a spiral groove (148), winding means (192) for the movement arranged to drive the fusee, a finishing gear train (200) arranged to be driven by the fusee, and a wire (106) stretched between the fusee and the barrel. The watch movement further comprises a fixed guide (155; 255) and a winding roller (157; 257) mounted to slide on the fixed guide. The winding roller is arranged to guide the wire as the fusee rotates and to simultaneously ensure the insertion of the wire into the groove (148) and its extraction from it.