{
    "title": "Pendulum Pump",
    "inventor_name": "Bruce Feltenberger",
    "publication_year": 2010,
    "device_name": "Feltenberger Pendulum Pump",
    "goal": "Provide safe drinking water without electricity or fuel by using a gravity-assisted hand-operated pump and filtration system.",
    "problem_addressed": "Lack of access to safe drinking water in disaster-affected or off-grid areas where electricity and fuel are unavailable.",
    "concept_summary": "A double-reciprocating pendulum converts the force of gravity into a linear piston motion that pumps water. The pump is hand-operated, includes selectable pressure/volume settings, and can be combined with Aquathin filtration and reverse-osmosis modules to produce up to 1,000 gal/h of clean drinking water.",
    "detailed_description": "The Feltenberger Pendulum Pump (GP210) uses a rigid-arm pendulum whose axle reciprocates linearly as the pendulum swings. The axle is attached to a piston rod that pushes and pulls the pump piston, delivering water on both the in-stroke and out-stroke. Four pressure/volume (P/V) settings are selected via a selector pin, allowing the operator to trade pressure for flow. A gravity-assist reduces operator fatigue because only a short intermittent push is needed each swing. The pump can lift water about 25 ft, generate 60-70 psi (sufficient for reverse-osmosis), and is paired with Aquathin's AquaShield anti-microbial membrane filter and a reverse-osmosis unit that yields 400-500 gal/day of high-grade water. The system is hand-operated, requires no fuel or electricity, and can be deployed within an hour near a water source.",
    "category": "Mechanical Engineering",
    "principles": [
        "gravity assist",
        "pendulum reciprocation",
        "mechanical advantage",
        "pressure/volume trade-off",
        "filtration",
        "reverse osmosis"
    ],
    "scientific_domains": [
        "Mechanical Engineering",
        "Fluid Mechanics",
        "Water Treatment",
        "Renewable Energy"
    ],
    "mechanisms_of_action": [
        "gravity-driven pendulum swing",
        "linear piston motion",
        "pressure generation via P/V settings",
        "membrane filtration",
        "reverse osmosis"
    ],
    "materials": [
        "steel",
        "rubber",
        "plastic",
        "anti-microbial membrane"
    ],
    "energy_sources": [
        "gravity"
    ],
    "inputs": [
        "surface water source",
        "human manual effort"
    ],
    "outputs": [
        "pumped water",
        "filtered drinking water",
        "reverse-osmosis purified water"
    ],
    "claimed_performance": "1,000 gal/h of clean drinking water; 400-500 gal/day of reverse-osmosis water; lift height ~= 25 ft; operating pressure 60-70 psi; can serve ~4,000 people with 3 h/day operation.",
    "experimental_evidence": "First production model deployed to Haiti (May 2010) and used to provide drinking water for ~4,000 people; demonstration to U.S. military in Tampa, Florida; video evidence of pump operation; press release stating 1,000 gal/h filtration capacity.",
    "replication_status": "Deployed in Haiti and demonstrated to U.S. military; operational field units in use.",
    "keywords": [
        "gravity pump",
        "pendulum",
        "hand-operated",
        "water treatment",
        "reverse osmosis",
        "disaster relief",
        "filtration"
    ],
    "related_technologies": [
        "Aquathin filtration system",
        "reverse osmosis membrane",
        "gravity assisted power (GAP)",
        "hand-crank pump"
    ],
    "controversy_level": "low",
    "confidence_score": 0.9,
    "practicability_score": 0.8,
    "fringe_score": 0.1,
    "evidence_strength": 0.6,
    "risk_score": 0.2,
    "trl_estimate": 6,
    "source_urls": [
        "http://gravityassistedpower.com",
        "http://www.youtube.com/watch?v=BwC5mLoU--c",
        "http://www.mmdnewswire.com/safe-drinking-water-10135.html",
        "http://www.poten.com/NewsDetails.aspx?id=10639017"
    ],
    "organizations": [
        "Gravitational Energy Corporation",
        "Aquathin Corporation",
        "DriPowder LLC",
        "One-Life Missions Foundation"
    ],
    "applications": [
        "disaster relief water supply",
        "rural irrigation",
        "military field water purification",
        "off-grid sanitation"
    ],
    "limitations": [
        "Requires continuous human effort",
        "Lift height limited to ~25 ft (future deep-water version planned)",
        "Pressure limited to 60-70 psi",
        "Performance depends on operator skill and pendulum arc"
    ],
    "open_questions": [
        "Long-term durability of moving parts and membranes",
        "Cost per unit at scale",
        "Effectiveness of reverse-osmosis at higher lift depths",
        "Maintenance requirements in harsh environments"
    ],
    "red_flags": [
        "Marketing language exceeds peer-reviewed data"
    ],
    "evidence_quotes": [
        "provides 1,000 gallons per hour of clean drinking water",
        "We use the pump for 3 hours a day, and this provides enough drinking water for approximately 4,000 people.",
        "gravity assist in helping us do work",
        "By turning the R/O handle to the on position and swinging the pendulum, 60 to 70 psi will automatically be achieved.",
        "first production model was sent to earthquake-stricken Haiti."
    ]
}