Patent ID: 7025343
Filing Date: 2006-04-11
Classification: F16F

Abstract:
1. An adjusting mechanism for remedying a coil pitch tolerance and fatigue deformation of an adjustable helical spring through working with an externally grooved rotatable element, said adjustable helical spring being mounted in a casing consisting of a male and a female case, and having an end connected to said rotatable element, comprising a fixing case, a preset barrel, a turning knob, a drive cylinder, a rotator knob, a drive shaft, a spacer, and a retaining key; said fixing case being a hollow case having a central hole formed at a bottom end, said bottom central hole having an inner diameter smaller than that of a front end of said fixing case opposite to said bottom end; said fixing case being provided at a predetermined position near said bottom central hole with first external threads to mesh with internal threads provided in an open end of said male case of said adjustable helical spring, so as to fixedly connect said whole adjusting mechanism to said casing for said adjustable helical spring; said fixing case being provided with an axial slot of a predetermined length, said axial slot having a bottom end close to said bottom end of said fixing case, and a front end opposite to said bottom end; said fixing case also being provided around said bottom end with second threads; said preset barrel being a hollow member with internal threads provided in a first end to mesh with external threads provided on said drive cylinder, and in an opposite second end to mesh with external threads on said rotatable element; said helical spring being connected at an end to an outer peripheral surface of said second end of said preset barrel; said retaining key being mounted at a predetermined position on the outer peripheral surface of said preset barrel and guided by said slot on said fixing case to axially move said preset barrel; said drive cylinder being a hollow member with a first end extended through said bottom central hole of said fixing case to tightly engage with said turning knob, and an opposite second end provided with external threads to mesh with said internal threads in the first end of said preset barrel; said turning knob being manually operable for adjusting precompression or pretension of said helical spring, and being located at an outer side of said bottom central hole of said fixing case to tightly engage with said drive cylinder; whereby said turning knob is smoothly turnable relative to said fixing case to rotate said drive cylinder; said drive cylinder rotated by said turning knob and said retaining key on said preset barrel and guided by said slot on said fixing case together causing said preset barrel to move axially; said spacer being an internally threaded member screwed to said second external threads of said fixing case; said drive shaft having a first end extended through said bottom central hole of said fixing case and a central hole on said spacer to tightly engage with said rotator knob, and an opposite second end having axially extended drive keys spaced on an outer surface thereof to slidably fit in an axial keyway provided on said rotatable element; and said rotator knob being manually turnable for adjusting the number of effective turns of said helical spring, and being located at an outer side of said spacer to tightly engage with the first end of said drive shaft; whereby said rotator knob is smoothly turnable relative to said spacer to rotate said drive shaft and, accordingly, said rotatable element, which is connected to said drive shaft via engagement of said axial keyway on said rotatable element with said axial drive keys on said drive shaft; and said rotatable element is brought to turn and axially move at the same time due to said retaining key on said preset barrel and the engagement of said external threads on said rotatable element with said internal threads in said second end of said preset barrel.