Unlike the traditional pocketknife in which the backspring rises and falls when the blade is opened and closed, the backbar of Tom Ferryās model equipped with the Everflush Spring (top) remains flush when the blade is opened and closed. Ferry (above) works on a model with the mechanism in his shop.
The Everflush Spring takes the traditional pocketknife folding mechanism to the next level
By Lorien Arnold
As the traditional slip joint experiences a rebirth in favor among knife enthusiasts, there is increasing room for innovation in the knifeās classic, time-tested construction method.
Enter Tom Ferry and Mike Vagnino.
Innovators and educators, they have forged their paths in steel. Developing techniques and learning new skills, while at the same time teaching others, the two have collaborated on a concept that incorporates a generations-old method for assembling a slip joint, while bringing it into new worlds of materials and technology.
ā[An] idea evolved from the desire to engrave the backbar of slip-joint folders,ā Ferry began. āThe reason this was all but impossible before was that slip-joint backbars or [back]springs are heat treated, making them difļ¬cult to engrave, and, due to timing issues, [the engraving] was not easily done prior to heat treatment.
āI had been bouncing the idea around trying to come up with a solution. One night while opening an automatic knife I noticed the internal kicker spring, which in many ways is similar in placement to a slip-joint spring. After doing some preliminary drawings, I contacted Mike for his input and assistance in developing the mechanism further. By sharing and combining forces, we cut the development time in half and have created a great working mechanism.
āIn total there have been at least five variations of the spring,ā Ferry continued, āand Mike has taken the development further by creating the ļ¬rst multi-blade slip joint with the [new] mechanism. Mike coined the name the Everļ¬ush Spring because the backbar is always ļ¬ush with the top of the handle.ā
You will notice the knives with the new spring in the accompanying photographs do not always correspond in form to the classic interpretation of the slip joint. Sporting titanium liners, bolsters and backbars, carbon fiber handles and high-alloy stainless blades, materials more common in the tactical category can be used to constitute the knives. To that end, the Everflush Spring allows for a completely solid handle configuration.
The standard slip joint, whose backbar is a spring and must be free to move, can develop play on either side of the spring. The Everflush Spring design can incorporate pivot bearings for an action that is smooth with a crisp half stop. āThe Everļ¬ush Spring is unlike common slip joints where the blade causes the spring to rise and drop as you rotate the blade from the open to closed position,ā Ferry observed. āThis innovation allows the opportunity for engraving of the backbar as well as eliminating the timing of the blade to the handle, as all the timing is internal.
ā[By] splitting the backbar in half, thus creating a lower spring upon which the blade rides and an upper tang stop which stays ļ¬ush with the handle, the backbar does not need heat treatment. This allows a wider range of material choices and embellishing options.ā
Being intrinsic with the backbar, the lower spring diminishes the pressure exerted upon the pin, which traditionally would be used as the spring pivot. This allows the use of more exotic or fragile handle materials without fear of them cracking at the pin. In addition, the mechanism provides the potential for assembling a slip joint using threaded fasteners that allow for easy cleaning and pivot-tension adjustments.
āThe major disadvantage is that this design will not easily ļ¬t or adapt to many traditional designs,ā such as folding patterns with three or more blades, Ferry noted. āThe internal spring takes up more room and thereby creates issues with designing a knife for it.ā Conversely, it challenges makers to devise new designs, which is always good for the knife industry.
Tango Foxtrot Knives
Ferry responded to the changing market with the creation of Tango Foxtrot Knives LLC, which he characterizes as his ānew venture into the realm of semi-production knivesā of his design.
āThe ļ¬rst knife from Tango Foxtrot is a tactical slip joint with the new mechanism, but I will also be introducing other models and types of knives in the future,ā he said. āTango Foxtrot Knives was conceived years ago but the timing never seemed to be right for me to proceed with the venture.
āAs with any new design or product, you can never be sure how it will be received by the buying public. Mike and I unveiled the Everļ¬ush Spring at the 2011 BLADE Show (www.bladeshow.com) and it was very apparent the design was a success, with both of us selling out of those knives prior to the end of the showās ļ¬rst day. With the conļ¬dence of having innovated a great product, I decided to launch Tango Foxtrot Knives. The companyās ļ¬rst release was the prototype version of the T-1 folder at the 2011 USN Show, and again the design went over well.
āI am currently in production of the T-1 slip joint with the Everļ¬ush Spring,ā Ferry maintained, āas well as designing other models of ļ¬xed blades and folders to develop a line of semi-production knives of my design. The components for the knives will be made out of shop, but all ļ¬nal assembly and ļ¬t and ļ¬nish will be done in my shop. Most will be everyday user knives, but there will also be the occasional dressed-up model featuring my hand engraving.ā
Another Level
The knife business tends to reward those who contribute to it. Moreover, there is always a connection to the past, as every maker builds upon the innovations, techniques and styles of those who came before. It is a rare cutler who introduces something completely new. It is an even rarer one who can take an innovation and bring it to the next level. There is always another level and, through Ferry and Vagninoās innovation, the cutlery industry may be getting a peek at the next one.
For more information on the Everflush mechanism, contact Tom Ferry at [email protected] or www.tomferryknives.com , or Mike Vagnino at [email protected] or www.mvknives.com.
For more on the latest knives, knife legislation, knifemaking instruction, knife trends, knifemakers, what knives to buy and where and much more, subscribe to BLADE Magazine, the World’s No. 1 Knife Publication. For subscription information click on http://www.shopblade.com/product/blade-magazine-one-year-subscripti…?r+ssfb031712#BL1SU.
