Blade Theory
The Strait blades and the curved blades have "style" unique benefits. This idea crosses the two styles and hopes to retain the benefits of both.
Giant Alternative to Pellenc system. Weighs 1.74 lbs.
I will use the present connecting apparatus to interface with the Pruner to focus on the cutting edge.
This is an advanced example of cutting edge. However, it still uses the curved scissor blade with a rivet to maintain friction clearance.
Giant Alternative to Pellenc system. Weighs 1.74 lbs.
Blade to Anvil Interaction
There is an inherent flaw in using a single bypass cutting system in an energy dependent system. There is parasitic friction necessary to keep clearance of the blade at the proper levels. A single anvil system negates the friction. Valuable energy is then saved for longer usage times or reduced weight of batteries. Further, the end user can change the blades with a simple and reliable process.
The original cutting system "hangs up" when the blade is fully closed. The geometry of the actuation arm to the center pivot of the cutting head is such that, there is enormous force required to overcome the linear condition. This project also addressed that parasitic energy loss.
All standard pruners use one rake angle on any one blade . What ever that angle is, it stays the same as it progresses from "hilt" to tip. This project focuses partially on the variable rake angle from 30° at the hilt, changing to 15° at the center of the cutting area. Then, back to 30° at the tip of the blade (Fig 2.) The rake angles were determined from common knowledge in the ax and blade making industry (Fig 1.)This will be tested as a comparison to the original pruner, with respect to the shape of the force vs. distance curve.
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There are single bypass shear systems that use the "leaf" profile shape. Then there are anvil systems, that all have a strait blade profile. As shown in the pictures above, the shapes never cross into the others' genre. this project also crosses that limit, allowing for the best attributes of both system types and few of the drawbacks.
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Figure 1
