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kickback brake
CIRCULAR SAW WITH SAFETY FEATURE TO PREVENT INJURY FROM KICKBACK
Cause of circular saw injuries
slip 17% unknown 9% contact with blade 30%
kickback 44%
kickback brake CIRCULAR SAW WITH SAFETY FEATURE TO PREVENT INJURY - - PowerPoint PPT Presentation
kickback brake CIRCULAR SAW WITH SAFETY FEATURE TO PREVENT INJURY - - PowerPoint PPT Presentation
kickback brake CIRCULAR SAW WITH SAFETY FEATURE TO PREVENT INJURY FROM KICKBACK Cause of circular saw injuries slip 17% kickback unknown 9% 44% contact with blade 30% Product Vision Circular saw with integrated kickback prevention
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Product Vision
Circular saw with integrated kickback prevention features
Braking mechanism Anti-kick mechanism
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Customer Need Attributes Engineering Specs
Reliably detect a kickback event Fault detection Detect a voltage drop greater than 4V.
How does the saw “know” kickback is happening?
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Test: simulating kickback to characterize voltage drop
≈ 4V drop
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Voltage Drop Data
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Customer Need Attributes Engineering Specs
Limit translational motion of saw during kickback Range of motion Kickback vertical distance less than 5cm to keep blade inside material
How far does the saw move during kickback?
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Skate Mechanism
Skate Prevents tool from flying
- ut of the material
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Customer Need Attributes Engineering Specs
Stop blade rotation during a kickback Blade rotational velocity Stopping time less than 40ms
How can we limit severity of injury?
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Caliper Brake
Caliper Brake Saw Blade Compression Spring Brake line Release pin and line RELEASE PIN ACTUATES SPRING
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Customer Need Attributes Engineering Specs
Operates normally under non- kickback conditions Usability Safety mechanism located
- utside of normal cutting path.
Weight and size of tool is within 20% of normal size.
How might this safety feature be unobtrusive?
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Usability
Must be retractable for plunge cuts Braking integrated into existing tool features Clutch braking on rotor instead of in the path of blade
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Target Market
First-time User Professional Experienced User Frequent User Amateur User
- Targeting makerspaces (amateur — experienced users) to reduce
concerns about injury liability
- Targeting professionals for workplace injury prevention
- Price estimate of $300 - $350 for a saw with kickback brake
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appendix
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Product Contract
Customer Need Attributes Engineering Specs
Limit translational motion of saw during kickback Range of motion Kickback vertical distance less than 5cm to keep blade inside material Operates normally under non- kickback conditions Usability Safety mechanism located outside
- f normal cutting path.
Weight and size of tool is within 20% of normal size. Stop blade rotation during a kickback Blade rotational velocity Stopping time less than 40ms Reliably detect a kickback event Fault detection Detect a voltage drop greater than 4V.