COTUIT, MA - A former woodworker, industrial engineer and inventor says he has received a patent on a flesh-sensing table saw safety braking system. David Butler, who is principal of Whirlwind Tool, Cotuit, MA, says he has spent years developing the system intended to prevent serious injuries among table saw users.

 Table saw safety is under increasing scrutiny as the Consumer Product Safety Commission considers a requirement that table saws be outfitted with some type of electronic safety device that would freeze the saw blade it it comes into contact with flesh. California is also considering a law that would require table saw safety brakes. SawStop is the only producer of saws outfitted with such braking systems.

A search of the United States Patent  database reveals Patent No. 8,082,825 was issued to Butler on December 27, 2011. It covers an earlier version of his table saw safety braking system. Originally applied for June 9, 2009, Butler's "Health and safety system for a table saw" describes a system incorporating a plastic blade guard with sensor, an aggressive dust collection system, and a saw motor braking system:

a blade guard that protects the operator from the saw blade, and contains and collects sawdust; a proximity detector and emergency saw motor braking means for use in connection with such blade guard; an anti-kickback device for use in connection with such blade guard, a rip fence adapter for use in connection with such a blade guard, and hoses and fittings to connect the dust containment and collection system of said blade guard to a shop dust collection blower or vacuum system. The system protects the saw operator from potential traumatic injury to a hand, and from ingesting potentially carcinogenic sawdust.

Whirlwind Tool has developed versions of the saw safety device incorporating "Proximity Sensing" for Makita, Delta, Rigid and Powermatic saws. The latest version, called a "Black Box" table saw emergency blade brake, is a bolt-on/removable device that can be incorporated into use with millions of existing saws, including band saws, and to other woodworking machinery already in the field.

Butler says the prototypes showcased on his site differ from previous table saw blade guards and emergency blade brakes, since they use an "electronic fence” blade enclosure. Removable, extended safety shields can be wide or narrow to offer varying safety margin depending on user comfort and experience.

"If the operator approaches or touches the clear blade guard fence, the proximity detector will immediately shut down the saw motor and stop the blade, without damage, in one-eighth of a second — long before the operator can contact the spinning blade," Butler explains on his website. "The saw can be restarted almost immediately."   Butler says he hopes to license the technology to a large company that can bring it to market.



Frequently Asked Questions

We do not have any hardware products for sale and it is not our goal to sell hardware.  Rather, we are beginning to negotiate with machinery manufactures regarding our pending patents to bring quality flesh-sensing hardware products to market just as quickly as possible.

Please refer to our 2012 Business Update.

Personally, I’m not an experienced manufacturing engineer so I can only guess at a product price, maybe just like you can.  We certainly hope the production models will be affordable for all users.  The price will be determined by the profile and plans of the company or companies that further develop these products for the market.  Both the financial and human resources of such companies will be the major factors in determining the product price.  Skilled manufacturing engineers will of course be sure the finished products are well tested, reliable and conform to the many safety standards required by CPSC, OSHA and other regulatory agencies and there is a cost for such development activity.

The short answer is, yes.  Whirlwind flesh-sensing prototypes have already been tested on the most common single-phase powered table saw designs from small bench-top saws up to cabinet saws of 3HP and there is no reason we cannot go to higher powered machines as well.   The key factor is to design an appropriate machine safety or blade guard and the great news is that we envision blade guards that will fit many, existing machines including some that date back many years and operate on power systems both in and outside of the US power standard.

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