“Shocking absorbing” blade stop for a folding knife

Information

  • Patent Grant
  • 6748661
  • Patent Number
    6,748,661
  • Date Filed
    Wednesday, March 27, 2002
    22 years ago
  • Date Issued
    Tuesday, June 15, 2004
    20 years ago
Abstract
A shock absorbing blade stop for a folding knife comprising; an elongated, cylinder shaped body, with o-ring grooves provided near its opposite ends. O-rings of a resilient material affixed to the o-ring grooves and the completed assembly located within the handle frames of a folding knife by means of location holes provided in the handle frames for that purpose. Location holes are of an inside diameter closely corresponding to the outside diameter of the mounted o-rings thereby producing a shock absorbing effect in response to the impact of a fast opening blade colliding against the blade stop. An enlarged center section of the blade stop is provided with an increased diameter slightly larger than the locating holes of the handle frames so as to capture the blade stop within the space between handle frames.
Description




BACKGROUND




1. Field of Invention




This invention relates to folding knives, specifically to an improved method of stopping the opening blade of such knives.




2. Description of Prior Art




The evolution of the folding knife, and its related mechanisms, has made dramatic improvements in recent years. Custom knife makers, such as myself, have developed numerous innovations aimed at overcoming the inherent weaknesses of a knife that folds into itself.




The two main advantages of a folding knife, as opposed to a fixed blade knife, are that it can be reduced to a more compact configuration for comfortable carry and it does not require a separate sheath to protect the user from the sharp edge.




The main disadvantages of a folding knife, as compared to a fixed blade knives, are as follows:




(a) A folding knife, being constructed of multiple moving parts, can never be made quite as strong or quite as reliable as a fixed blade knife.




(b) A folding knife poses a greater danger to the user than mere breakage because a mechanical malfunction may allow the sharp blade to close on the fingers.




(c) A folding knife is much slower to deploy in an emergency because of the additional and necessary step of opening the blade before using.




The direction that the evolution of folding knife design has taken is that of attempting to solve the inherent shortcomings of folding knives as compared to the fixed blade knife. Custom knife makers and factory knife designers everywhere are hard at work in an attempt to make folding knives stronger, safer and faster. There exists a vast body of prior art related to folding knife design, most of which is directly aimed at solving one or more of these three primary weakness.




A recent trend has been to build folding knives of heavier stronger components while at the same time developing mechanisms that allow for a very fast opening of the blade.




This new trend has generated a new problem in that a heavier faster opening blade has the effect of greatly increasing the impact upon the blade stop. The result of this condition is that makers are experiencing high failure rates for locking mechanisms, blade stops and the surfaces that locate the blade stop.




OBJECTS AND ADVANTAGES




Accordingly, the object of my invention is to solve the problems associated with the use of the heavier, faster opening blades of modern folding knife design.




The “shock absorbing” blade stop offers a simple elegant solution to a difficult problem through the use of easily made components, such as a lathe turned blade stop provided with o-ring grooves and easily available components such as commercially made o-rings. O-rings are made in a wide variety of sizes and materials. Urethane which is among the most durable and therefore the more desirable of the readily attainable materials is also available in a variety of durometers ranging from hard to soft so that correct combinations are easily achieved.




The chief advantage of the shock absorbing blade stop is to dramatically reduce the wear and deformation of the blade stop, pivot pin, and locking mechanism of a folding knife, when that folding knife is subject to the abuse associated with hard and fast opening of a heavy blade.











DRAWING FIGURES




In the drawings, closely related figures have the same number but different alphabetic suffixes.





FIG. 1A

shows, a complete folding knife with a typical location for the blade stop encircled.





FIG. 1B

shows an enlarged view of the encircled area containing the blade stop with cross section lines indicating the view shown in FIG.


2


.





FIG. 2

shows a cross section of that area containing the blade stop, including blade, blade stop body, o-rings and handle frames





FIG. 3

shows a perspective view of the stop body with o-rings attached.















Reference Numerals In Drawings




























10




blade stop




12




o-rings







14




enlarged diameter




16A




handle frame







16B




handle frame




18




blade







22




locating holes




20




allowance for travel







24




o-ring grooves






















DESCRIPTION—FIGS.


1


TO


3






A typical embodiment of the “shock absorbing” blade stop of the present invention is shown at the figures listed below.

FIG. 1A

show a folding knife with the area encircled containing a typical location for a blade stop


10


,

FIG. 1B

shows an enlarged view of the same area with a cross section line delineating the cross sectional view of FIG.


2


.

FIG. 2

shows a blade


18


in its open position at rest against the blade stop


10


. Blade stop


10


is shown inserted into the handle frames


16


A and


16


B by means of the holes


22


provided in handle frames


16


A and


16


B for that purpose. Blade stop


10


is shown captured between handle frames


16


A and


16


B by reason of the enlarged diameter


14


of blade stop


10


being of a somewhat larger diameter than the locating holes


22


of handle frames


16


A and


16


B. O-rings


12


are shown contained within o-ring grooves


24


of blade stop


10


and in contact with the inside diameter of locating holes


22


provided within handle frames


16


A and


16


B. An allowance for travel


20


is also shown between the blade stop


10


and the inside diameter of locating holes


22


of handle frames


16


A and


16


B.

FIG. 3

is a perspective view of blade stop with o-rings in place.




Operation—

FIGS. 1

to


3






In operation, movement is initiated by the opening of blade


18



FIG. 2

which impacts blade stop


10


causing it to move within the confines of allowance for travel


20


restrained only by the degree of resiliency contained within the material of o-rings


12


. The resiliency of o-rings


12


has the effect of absorbing the shock of the opening blade


18


as it impacts the blade stop


10


.




SUMMARY




In accordance with the present invention, a “shock absorbing” blade stop, of an elongated cylindrical configuration, provided with o-ring grooves and o-rings near its end points and located by holes bored in the handle frames of a folding knife.




Conclusion, Ramification, and Scope




Thus the reader will see that the blade stop of the present invention provides a simple, reliable, yet economical solution to the emerging problem of premature wear and or damage to a folding knife of fast opening, heavily constructed, modern design.




While my above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible, for example, instead of O-rings, other shapes of resilient materials or even springs could be used to produce the same effect. In addition blade stops are sometimes installed on the blade instead of the handle frames which would only require a reconfiguration of the principle elements of this invention.



Claims
  • 1. A shock absorbing blade stop for a folding knife, comprising;(a) a blade stop of sufficient size and substance to provide a reliable stopping point for the opening blade of a folding knife, (b) a resilient component, selected from the group containing elastomers and springs, configured and positioned to occupy a predetermined space between said blade stop and that portion of said knife to which it is adjoined, whereby said blade stop is allowed some predetermined measure of travel, restrained primarily by the degree of resiliency contained within said resilient component, wherein the blade stop is configured to the shape of an elongated cylinder provided with o-ring grooves cut near its opposite ends surrounding the circumference.
  • 2. The blade stop of claim 1 wherein o-rings made of a resilient material are affixed to the o-ring grooves provided at each of the opposite end, of the blade stop.
  • 3. The blade stop of claim 2 wherein the stop body together with it's attached o-rings is captured within the handle frames by holes provided in said handle frames for that purpose, said holes being of an inside diameter essentially conforming to the outside diameter of said o-rings.
  • 4. The blade stop of claim 3 wherein the blade stop is provided with a centrally located enlarged diameter of a dimension slightly larger than the locating holes in the handle frames, whereby said blade stop is securely contained between said handle frames but free to travel at right angles to its long axis, retrained only by the resiliently of the material from which the o-rings are made.
US Referenced Citations (2)
Number Name Date Kind
3882599 Plum May 1975 A
6105255 Cheng Aug 2000 A