In a message dated 99-02-24 22:59:35 EST, jcmartin43_at_radix.net writes: << Another option would be to buy a Whale or Gusher handpump for around $45, find a stainless steel conical compression spring to install inside the pump body (having removed the handle) and adding a pedal of some sort to the flange; but having tried this with very limited success, it's not the greatest option. >> This has come up in previous threads and I have failed to ask what seems an obvious question: Why use a spring return for the diaphragm? This sounds to be slow acting, a waste of energy, and prone to spring failure. The pivot pin for the handle on such pumps is located to the side of the diaphragm, so why not modify the handle to turn it into a treadle, using the same pivot? For those of you who may not be familiar with such archaic machinery as treadle-operated sewing machines, I am referring to a foot- actuated lever which is pivoted at the center rather than at the end (gas peddle) so that you can translate pushing motions on each side of the pivot into bidirectional motion. Push on the side of the treadle opposite the diaphragm to expand the diaphragm, on the same side to compress. You could either mount the pump so the treadle is vertical, requiring a heal/toe rocking action of one foot to pump, or mount the pump so the treadle is horizontal, allowing you to use one or both feet on alternate sides to rock the treadle. I could foresee problems with footroom, but it seems a logical and relatively easy solution. Has anyone tried such a modification? Just wondering, Harold *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.gasp-seakayak.net/paddlewise/ ***************************************************************************Received on Fri Feb 26 1999 - 19:03:35 PST
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