Securing structure of folding knife

A securing structure of a folding knife includes a blade and a handle. The blade is pivotally connected to the handle and has a pivotal connection end provided with a first engaging groove and a second engaging groove. The handle has two opposite sides each provided with a first guide hole. A stop block is provided in the handle and has a stop surface for abutting against an abutting surface of the blade. The stop block also has an inclined guide surface. The inclined guide surface is adjacent to the first guide holes and is inclined in a direction from the upper handle edges toward the front handle ends. A pin extends through the two first guide holes and can be engaged in either one of the first and the second engaging grooves and thereby clamped between a wall portion of the engaging groove and the inclined guide surface.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a folding knife and more particularly to a securing structure of a folding knife.

2. Description of Related Art

Folding knives are in extensive use because of their ease of use, convenient storage, and high portability, and they differ from one manufacturer to another in how the blade is rotated and secured. One way to secure the blade of a folding knife is to use a locking pin, as disclosed in U.S. Pat. Nos. 8,572,851 and 9,862,104. Take the structure of U.S. Pat. No. 8,572,851 for example. The main structural features of a folding knife having such a structure include a handle and a blade, wherein the blade is pivotally connected to one end of the handle and can be rotated with respect to the handle. The handle is penetrated by a slot that is open on two opposite sides of the handle. A pin extends through the slot, and the two ends of the pin are exposed from the two opposite sides of the handle through the slot openings respectively so as to be operated by a user. The end of the blade that is pivotally connected to the handle is provided with at least two grooves in either of which the pin can be engaged. The foregoing structure is so designed that the blade can be secured by bringing the pin into engagement in either one of the grooves of the blade and the slot of the handle. When it is desired to rotate the blade out of the handle, it is required to move the pin from one end to the other end of the slot and thereby disengage the pin from one of the grooves of the blade so that the blade can be rotated with respect to the handle.

The structure described above relies on the pin to secure the blade in place, and the pin itself is secured by engaging with a wall portion of either groove of the blade and a wall portion of the slot, which is open on the two opposite sides of the handle. This securing structure, however, is not secure not only because the blade is not sufficiently supported, but also because the pin may easily come out of the groove in which it is engaged; as a result, the blade is unstable when rotated during use.

BRIEF SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a securing structure of a folding knife, wherein the securing structure is structurally simple and has a firm securing effect.

To achieve the primary objective, the securing structure provided by the present invention for a folding knife includes a blade and a handle. The blade has a pivotal connection end pivotally connected to the handle. The pivotal connection end of the blade is provided with a first engaging groove and a second engaging groove. The handle has two opposite sides each provided with a first guide hole. A stop block is provided in the handle. The stop block has a stop surface, and the stop surface abuts against an abutting surface of the blade when the blade is in a fully extended position. The stop block is also provided with an inclined guide surface. The inclined guide surface is adjacent to the first guide holes and is inclined from one end toward the engaging grooves of the pivotal connection end such that the end of the inclined guide surface that is adjacent to the blade is closer to the lower handle edges than is the opposite end of the inclined guide surface. A pin extends through the two first guide holes and can be engaged in either one of the first engaging groove and the second engaging groove.

The securing structure provided by the present invention for a folding knife is so designed that the pin can be guided selectively into one of the first engaging groove and the second engaging groove by the inclined guide surface and end up clamped between the inclined guide surface and a wall portion of the one of the first engaging groove and the second engaging groove, thereby preventing the blade from further rotation while the pin itself is kept from coming out of the one of the first engaging groove and the second engaging groove.

Preferably, the handle is provided with a control element connected with two linking members, and the two linking members are connected to the two ends of the pin respectively such that the pin can be driven to move by the control element.

Preferably, the handle is provided with an elastic element, and the elastic element is configured to store a restoring force for bringing the pin back in place after the pin is displaced.

Preferably, the first engaging groove and the second engaging groove are provided in an outer annular portion of the blade and form an included angle θ at least greater than 90 degrees.

DETAILED DESCRIPTION OF THE INVENTION

To begin with, the applicant would like to point out that throughout this specification, including the description of the following embodiments and the appended claims, all the directional terms make reference to the directions shown in the accompanying drawings, and that identical or similar elements or structural features in the following embodiments and the drawings are indicated by the same reference numeral.

Referring toFIG.1toFIG.6, a securing structure of a folding knife according to the first embodiment of the present invention includes a handle1and a blade2. The blade2is pivotally connected to the handle1at one end in order to be switchable between a fully extended position and a fully folded position. The handle1includes a main body10, two side plates20, two housing portions30, a pin40, two elastic elements50, and a stop block60.

The main body10is elongated in shape.

The two side plates20are also elongated in shape and are provided on two opposite sides of the main body10respectively such that the main body10is sandwiched between the two side plates20, with a space formed between the two side plates20in order to receive the blade2. As the two side plates20have the same structure, only one side plate20is described below by way of example. The side plate20has two long-side edges defined respectively as an upper handle edge201and a lower handle edge202. One end of the side plate20is provided with a pivotal connection hole203. The end of the side plate20that is provided with the pivotal connection hole203is defined as a front handle end204while the opposite end of the side plate20is defined as a rear handle end205. The side plate20is provided with an elongated first guide hole206. The major-axis direction of the first guide hole206extends along the major-axis direction of the side plate20, and the end of the first guide hole206that is adjacent to the front handle end204is slightly curved toward the lower handle edge202.

The two housing portions30are elongated in shape and are provided on the outer sides of the two side plates20respectively such that the two side plates20are located between the two housing portions30. Each housing portion30is provided with a guiding hole31. The guiding holes31correspond in shape and position to the first guide holes206of the side plates20.

The pin40extends through the guiding holes31of the two housing portions30as well as each first guide hole206. The two ends of the pin40are exposed from the two housing portions30respectively.

The two elastic elements50are provided on the outer sides of the two side plates20respectively. Each elastic element50has one end connected to the corresponding side plate20and the opposite end abutting against the pin40in order to apply a restoring force to the pin40after the pin40is displaced. In this embodiment, the elastic elements50are springs. The elastic elements50, however, are not essential. The provision of the elastic elements50is intended for the pin40to return to its original position automatically after being displaced. It is nevertheless feasible to dispense with the elastic elements50altogether or provide only one elastic element50.

The stop block60is sandwiched between the two side plates20and is adjacent to the front handle ends204. The stop block60has a stop surface61. The stop surface61abuts against an abutting surface217of the blade2when the blade2is in the fully extended position. The stop block60is also provided with an inclined guide surface62. The inclined guide surface62is adjacent to the first guide holes206and is inclined in a direction from the upper handle edges201toward the lower handle edges202and the front handle ends204. The end of the inclined guide surface62that is adjacent to the blade2is closer to the lower handle edges202than is the opposite end of the inclined guide surface62.

The blade2includes a cutting-edge end211and a pivotal connection end212. The pivotal connection end212is provided with a pivot shaft213and an outer annular portion214surrounding the pivot shaft213. The blade2is pivotally connected to the pivotal connection holes203of the two side plates20via the pivot shaft213and can be rotated with respect to the handle1about an axis defined by the pivot shaft213. The outer annular portion214has a fan-like configuration extending about a center of circle defined by the pivot shaft213. Moreover, the outer annular portion214is provided with a first engaging groove215and a second engaging groove216, and the pin40can be engaged in either one of the two engaging grooves. With the pivot shaft213serving as the vertex, the two engaging grooves define an included angle θ therebetween, and the included angle θ is at least greater than 90 degrees. The abutting surface217is provided at the pivotal connection end212.

The securing structure provided by this embodiment for a folding knife can work while the blade2is in the fully extended position, as shown inFIG.3. When the blade2is in the fully extended position, the abutting surface217of the blade2abuts against the stop surface61of the stop block60, and the pin40is in the first engaging groove215and is clamped between a wall portion of the first engaging groove215and the inclined guide surface62of the stop block60. As the inclined guide surface62is inclined toward the lower handle edges202and therefore guides the pin40deeper into the first engaging groove215, the pin40is secured in place and is kept from coming out of the first engaging groove215.

To fold the blade2, the user begins by moving the pin40along the first guide holes206of the two side plates20until the pin40is outside the first engaging groove215, thereby allowing the blade2to be rotated with respect to the handle1. Once the blade2is in the fully folded position after being rotated from the fully extended position, the user releases the pin40so that the pin40is pushed back to its original position by the restoring force stored in the two elastic elements50and ends up engaged in the second engaging hole216. The pin40in this state is clamped between the inclined guide surface62and a wall portion of the second engaging groove216to prevent further rotation of the blade2, and the pin40itself is kept from coming out of the second engaging groove216.

The structure of the present invention uses multiple portions (namely the inclined guide surface62, the wall portions of the two first guide holes206, and the wall portions of the engaging grooves of the outer annular portion214) to clamp the pin40securely in position, which coupled with the abutting surface217of the blade2abutting against the stop surface61of the stop block60enhances the stability of the blade2while the blade2is used in the fully extended position.

Referring toFIG.7toFIG.12, a securing structure of a folding knife according to the second embodiment of the present invention includes a handle1and a blade2. The handle1includes a main body10, two side plates20, two housing portions30, a pin40, a control element70, two linking members80, two elastic elements50, and a stop block60.

The main body10is elongated in shape.

The two side plates20are also elongated in shape and are provided on two opposite sides of the main body10respectively such that the main body10is sandwiched between the two side plates20, with a space formed between the two side plates20in order to receive the blade2. As the two side plates20have the same structure, only one side plate20is described below by way of example. The side plate20has two long-side edges defined respectively as an upper handle edge201and a lower handle edge202. One end of the side plate20is provided with a pivotal connection hole203. The end of the side plate20that is provided with the pivotal connection hole203is defined as a front handle end204while the opposite end of the side plate20is defined as a rear handle end205. The side plate20is provided with a first guide hole206, a second guide hole207, and a third guide hole208, the three of which are sequentially arranged at intervals in a direction from the front handle end204toward the rear handle end205. The major-axis direction of each guide hole extends along the major-axis direction of the side plate20, and both the end of the first guide hole206that is adjacent to the front handle end204and the end of the second guide hole207that is adjacent to the front handle end204are slightly curved toward the lower handle edge202.

The two housing portions30are elongated in shape and are provided on the outer sides of the two side plates20respectively such that the two side plates20are located between the two housing portions30.

The pin40extends through the first guide hole206of each side plate20, and the two ends of the pin40jut out from the two side plates20respectively.

The control element70is provided between the two side plates20and between the main body10and the blade2. The top side of the control element70is provided with a pushing portion71. The pushing portion71extends outward beyond the upper handle edges201of the two side plates20and is therefore exposed to view. Two opposite sides of the control element70are each provided with a first post72and a second post73. Each first post72extends through the third guide hole208of the corresponding side plate20, and each second post73extends through the second guide hole207of the corresponding side plate20, such that the control element70can be moved along the major-axis directions of the third guide holes208in order to be switched between a locking position and an unlocking position.

The two linking members80are located on the outer sides of the two side plates20respectively. Each linking member80has one end connected to the corresponding first post72of the control element70and the opposite end connected to the portion of the pin40that juts out from the corresponding side plate20.

The two elastic elements50are provided on the outer sides of the two side plates20respectively. Each elastic element50has one end connected to the corresponding side plate20and the opposite end abutting against the corresponding first post72of the control element70in order to apply a restoring force to the control element70after the control element70is displaced. In this embodiment, the elastic elements50are springs.

The stop block60is sandwiched between the two side plates20and is adjacent to the front handle ends204. The stop block60has a stop surface61. The stop surface61abuts against an abutting surface217of the blade2when the blade2is in the fully extended position. The stop block60is also provided with an inclined guide surface62. The inclined guide surface62is adjacent to the first guide holes206and is inclined in a direction from the upper handle edges201toward the lower handle edges202and the front handle ends204. The end of the inclined guide surface62that is adjacent to the blade2is closer to the lower handle edges202than is the opposite end of the inclined guide surface62.

The blade2includes a cutting-edge end211and a pivotal connection end212. The pivotal connection end212is provided with a pivot shaft213and an outer annular portion214. The blade2is pivotally connected to the pivotal connection holes203of the two side plates20via the pivot shaft213. The outer annular portion214has a fan-like configuration extending about a center of circle defined by the pivot shaft213. Moreover, the outer annular portion214is provided with a first engaging groove215and a second engaging groove216, and the pin40can be engaged in either one of the two engaging grooves. The two engaging grooves define an included angle θ therebetween, and the included angle θ is at least greater than 90 degrees.

The securing structure provided by this embodiment for a folding knife is shown inFIG.9in normal use, with the blade2in the fully extended position. The blade2in this position is exposed to view and extends forward from the handle1, with the pin40engaged in the first engaging groove215of the pivotal connection end212and clamped between a wall portion of the first engaging groove215and the inclined guide surface62of the stop block60to secure the blade2against rotation. As the pin40is connected with the two linking members80, which in turn are connected to the control element70, the control element70in this state is kept at the locking position (which is adjacent to the blade2) by the elastic force of the two elastic elements50.

To rotate and thereby fold the blade2away, the user begins by moving the control element70away from the blade2such that the control element70is moved from the locking position to the unlocking position and compresses the two elastic elements50. When the control element70is moved, the two linking members80drive the pin40out of the first engaging groove215as shown inFIG.10, thereby allowing the blade2to be rotated with respect to the handle1about an axis defined by the pivot shaft213.

Once the blade2is rotated to the fully folded position, referring toFIG.11andFIG.12, the user releases the control element70so that the control element70is pushed from the unlocking position back to the locking position by the restoring force of the two elastic elements50. During the process, the two linking members80are driven to move the pin40forward into engagement in the second engaging groove216of the outer annular portion214to secure the blade2in place. As a result, the pin40is clamped between the inclined guide surface62of the stop block60and a wall portion of the second engaging groove216to prevent the blade2from further rotation, and the pin40itself is kept from coming out of the second engaging groove216.

According to the structure of the second embodiment of the present invention, the pin40is moved by the control element70driving the two linking members80to move the two ends of the pin40respectively at the same time. A user, therefore, can move the two ends of the pin40simultaneously by sliding the control element70with only one finger, and the two ends of the pin40will not move in an unparallel manner. This enhances the convenience of use of the folding knife to which the invention is applied.

FIG.13toFIG.15show the third embodiment of the present invention. The structure of the third embodiment is generally the same as that of the second embodiment except that the third guide holes208in the two side plates20are circular holes, and that each second guide hole207is in the shape of an arc whose center of circle is defined by the corresponding third guide hole208. The control element70is provided between the two side plates20and between the main body10and the blade2. The control element70has two opposite sides each provided with a first post72and a second post73. Each first post72extends through the third guide hole208of the corresponding side plate20, and each second post73extends through the second guide hole207of the corresponding side plate20, such that the control element70can be pivoted about a rotation axis defined by the first posts72.

The two linking members80are connected to the second posts73and the pin40, and each of the two elastic elements50abuts against the corresponding second post73and the corresponding side plate20.

The structure of the third embodiment works in generally the same way as that of the second embodiment except that the control element70in the third embodiment is configured for pivotal movement rather than the forward-backward movement in the second embodiment. However, the control element70in the third embodiment is equally capable of driving the two linking members80at the same time in order for the linking members80to move the pin40.

To rotate and thereby fold the blade2away, the user begins by pivoting the control element70away from the blade2such that the control element70is rotated from the locking position to the unlocking position about the rotation axis defined by the second posts73and compresses the two elastic elements50. When the control element70is pivoted, the two linking members80drive the pin40out of the first engaging groove215as shown inFIG.15, thereby allowing the blade2to be rotated with respect to the handle1about an axis defined by the pivot shaft213.

Once the blade2is rotated into and stored in the handle1, the user releases the control element70so that the control element70is pushed, or pivoted to be exact, from the unlocking position back to the locking position by the restoring force of the two elastic elements50. During the process, the two linking members80are driven to move the pin40forward into engagement in the second engaging groove216of the pivotal connection end to secure the blade2in place.