2. Vibration Reduction Isolate Add-on for Jackhammers
Bad Vibrations 2 Million workers in the US exposed to hand-arm • vibration [1] No enforced regulations in the U.S. [2] • Jackhammers used for 4-5 Hours per day • Hand Arm Vibration Syndrome [3]
Existing Solutions Taking a Anti-vibration Electric Isolate Break Gloves Jackhammers with anti- vibration Effectiveness × ✔ ✔ ✔ Adaptability × ✔ ✔ ✔ Minimal Work × × ✔ ✔ Disruption
Isolate Isolate Add-On Active vibration • reduction system Price: $400 • Traditional Jackhammer
Isolate ENGINEERING CUSTOMER NEED PRODUCT ATTRIBUTE SPECIFICATION Reduce vibration exposure to Allow safe use for longer Vibration reduction below 5 ! periods " # Adjustable attachment End-to-end handle distance Keep current jackhammers mechanism between 12 to 24 inches Can be easily stored Height Less than 6 inches Less than 6 pounds Can be easily transported Weight New handle displacement Comfortable to use Less than 4” from old handle
Mockup – Passive damping • Tested out passive spring damping solution • Saw damping of higher Second stage frequencies rather than the problem frequencies Passive (10 – 50 Hz) damping springs Accelerometer Lower stage motor
Mockup – Passive damping
Mockup – Vibration Cancellation • Active vibration cancellation mockup • Uses upper-stage motor to cancel out vibration amplitude Upper stage motor Lower stage motor
Mockup – Active Damping
Risks • Voice-coil active damping/magnetic suspension • Compact system • Adaptable design • User need • Functionality on a jackhammer
References • [1]St. Michael’s Hospital. Hand-arm Vibration Syndrome, https://www.ohao.org/PDF/Hand%20Arm%20Vibration%20Syndrome%20March%2 020.pdf(Accessed 10/11/2018) • [2] Army Public Health Center. A Guide for Prioritizing Hand-Arm Vibration Exposure,https://phc.amedd.army.mil/PHC%20Resource%20Library/TG356_Vibrati onPocketGuide.pdf(Accessed 10/15/2018) • [3] http://www.altrad-belle.com/?p=health
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