The present invention relates to the field of knives, and, more particularly, to a double spring folding knife.
A folding knife is a type of knife that includes a handle and a blade pivotally attached to the handle. The blade is designed to swing out from the handle into the open position, and to remain folded into the handle when in the closed position.
A typical folding knife includes features to make the knife more useful and easier to operate. For example, these features may include a spring mechanism to assist the user in opening the knife. However, adding the spring mechanism to assist with opening the knife blade may also lead to the knife blade unintentionally swinging open when not intended. For example, when it is in the user's pocket or if the knife is accidentally dropped. This can lead to personal injury.
Prior attempts to address this shortcoming have been to include a locking mechanism to the folding knife in order to lock the knife blade in the closed position. However, the known locking mechanisms substantially increase the cost and complexity of manufacturing the folding knife. Accordingly, there is a need for a folding knife that includes a simplified feature to prevent the knife blade from unintentionally swinging open that does not increase the complexity or manufacturing costs.
It is, therefore, to the effective resolution of the aforementioned problems and shortcomings of the prior art that the present invention is directed.
However, in view of the prior art at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified needs could be fulfilled.
In a particular embodiment, a double spring folding knife is disclosed. The double spring folding knife includes a handle that has a first side and a second side, and forms a slot therebetween. The knife also includes a knife blade having a first end, a second end, and an opening proximate the second end. An axle is secured within the handle and through the opening proximate the second end of the knife blade, where the knife blade is configured to rotate about the axle to swing open from the slot. The knife also includes a first liner adjacent a first side of the knife blade and an interior surface of the first side of the handle. The first liner includes a curvilinear groove formed therein. A locking pin is proximate to a second end of the knife blade and extends away from a first side of the knife blade. The locking pin sliding engages the curvilinear groove and extends through the curvilinear groove to an opposing side of the first liner.
A bow spring is fixed to the opposing side of the first liner and is orientated to interact with the locking pin to exert a force on the locking pin during a portion of travel along the curvilinear groove. The knife also includes a coil spring that is coaxially positioned around the axle and has a first end fixed to the second side of the handle and a second end fixed to a second side of the knife blade. The coil spring is configured to exert an opening force on the knife blade after the locking pin has traveled past the bow spring along the curvilinear groove.
It is therefore an object of the present invention to provide for an improvement that overcomes the aforementioned inadequacies of the prior art and provides a significant contribution to the advancement of folding knives.
These and other important objects, advantages, and features of the invention will become clear as this description proceeds. The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the description set forth hereinafter.
Both the foregoing general description and the following detailed description are explanatory and are not restrictive of the invention. The accompanying drawings, which are incorporated in and constitute part of the specification, illustrate embodiments of the present invention and together with the general description, serve to explain principles of the present invention.
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. Like numbers refer to like elements throughout.
Referring initially to
The double spring folding knife 100 also includes a first liner 110 adjacent a first side of the knife blade 106 and an interior surface of the first side 102 of the handle 107. In addition, the first liner 110 has a curvilinear groove 113 formed therein that is used in conjunction with the action of a bow spring 116, described in more detail below. A belt clip 122 may be secured to the second side 104 of the handle 107 and can be used to removably attach the knife 100 to a belt of a wearer.
A locking pin 114 is proximate to the end of the knife blade 106 and extends away from a first side of the knife blade 106. The locking pin 114 sliding engages the curvilinear groove 113 and extends through the curvilinear groove 113 to an opposing side of the first liner 110. The bow spring 116 is fixed to the opposing side of the first liner 110 and orientated to interact with the locking pin 114 to exert a force on the locking pin 114 during a portion of travel along the curvilinear groove 113. The bow spring 116 is sandwiched between the first side 102 of the handle 107 and the first liner 110. The bow spring comprises steel or any suitable material. The bow spring 116 is configured to be compressed by the locking pin 114 as the blade 106 swings out and the locking pin 114 has to move past the elbow of the bow spring 116. Once the blade 106 is open, the bow spring 116 is not in contact with the locking pin 114.
A coil spring 118 is coaxially positioned around the axle 108 and has a first end fixed to the second side 104 of the handle 107 and a second end fixed to a second side of the knife blade 106. The coil spring 118 is configured to exert an opening force on the knife blade 106 after the locking pin 114 has traveled past an elbow of the bow spring 116 along the curvilinear groove 113.
The double spring folding knife also includes a second liner 112 adjacent the second side of the knife blade 106 and an interior surface of the second side 104 of the handle 107. The second liner 112 is biased to engage a bottom edge of the end of the knife blade 106 to lock the knife blade in an open position. A stop pin 138 is orientated between the first side 102 and second side 104 of the handle 107 and is configured to engage and stop the end of the knife blade 106 when swinging the knife blade into the slot formed in the handle 107.
Referring now to
A detailed view of the coil spring 118 and bow spring 116 is shown in
Once example of a coil spring 118 that may be used with the double spring foldable knife 100 is shown in
The bow spring 116 is shown in
Accordingly, the locking pin 114 pushes inward on the bow spring 116 as the locking pin 114 tries to move past the elbow 136 as shown in
Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
4776094 | Glesser | Oct 1988 | A |
7905022 | Hawk et al. | Mar 2011 | B2 |
8893389 | Freeman | Nov 2014 | B2 |
20030213134 | Sakai | Nov 2003 | A1 |
20150352731 | France | Dec 2015 | A1 |
20160067871 | Onion | Mar 2016 | A1 |
20180001488 | Wang | Jan 2018 | A1 |
20180133907 | Kao | May 2018 | A1 |
Number | Date | Country | |
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20190061180 A1 | Feb 2019 | US |