brando ha scritto:te mi sa che continui a non capire... vabbè affar tuo
grazie gugu
ti sarai mica offeso? peace! se vuoi una spiegazione tecnica allora è meglio che ti vada a vedere direttamente il brevetto.
PATENT NUMBER 4643377: US Patent for the dual-axle camming unit
design.
in particolare per il sistema a due assi ecco in cosa si differenzia dal sistema mono:
In view of the shortcomings characteristic of the prior art, an improved mechanically expanding climbing aid was taught by the applicant's Application Number 780,375 filed Sep. 26, 1985 now U.S. Pat. No. 4,643,377 which issued Feb. 17, 1987. The applicant's improved mechanically expanding climbing aid features two parallel axles on which opposing cam members rotate separately with crossed radii. As a result of the double axle structure, the cam members closely intermingle when retracted thereby significantly increasing the useful range of cam member movement from fully retracted to fully expanded. Consequently, a lower number of sizes are needed by the climber to accommodate the range of crack widths encountered while climbing. Because the cam member rotational radii are crossed and subsequently longer than radii of an equivalently sized single axle climbing aid, leverage and the resulting anchoring force are significantly greater. Similarly, because the cam member arcuate outer surface curvature is broader than that of an equivalently sized single axle climbing aid, the contact area with the crack walls is increased thereby reducing cam surface wear. Also, because bearing loads are shared equally by two axles instead of a single axle, the improved mechanically expanding climbing aid avoids structural failure due to high bending forces and couples.
The climbing aid taught by U.S. Pat. No. 4,643,377 is marketed under the trade name "Camalot". Camalot is manufactured in a range of overlapping sizes to accommodate crack widths from 2 to 18 cm (3/4 to 7 inches). The various overlapping sizes are essentially the same configuration with the component dimensions scaled up or down to achieve the desired expansion range. Scaling the Camalot double axle configuration small enough to accommodate crack widths under 2 cm has not been practical due to physical constraints. For example, 4 mm is the smallest useful diameter for an axle of adequate strength using state of the art materials, and it is not possible to have parallel 4 mm diameter axles spaced to mount interlocking cams and also have an assembly thin enough to provide the clearance needed to slip into cracks less than 2 cm wide. Even so, there is significant need in the climbing community for mechanically expanding climbing aids which can be placed in cracks under 1 cm wide and also have the wide expansion range and strength provided by cam members pivoting with crossed radii.
Ora mi dileguerò, nun te preocupe.
figata!
