I found that the current prosthetic split hooks and grippers all have only modest cable pull lever lengths. That means that when the lever has a length L, and the hook tip has a length M, that the cable force F(L) and the hook tip force F(M) are in relation of L\/M. So if the hook is longer than the lever, one never even gets the cable force as gripper closing force, and that (as far as I think) is a pity. If ever I am the first person to think this out loud then definitely you read that here first.<\/p>\n
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Because, if the lever is longer, one may enjoy lower cable forces – no matter how many rubbers on the Hosmer hook, or how strong the spring on a hook\/prehensor\/gripper device. With the TRS Jaws (original version), I liked the relatively high L\/M fraction, but with the new TRS Jaws XFS (very strong spring) I decided to finalize this project that was on my to-do list for a while now.<\/p>\n
Link to TRS regarding Jaws XFS:<\/p>\n