Information
-
Patent Grant
-
6397477
-
Patent Number
6,397,477
-
Date Filed
Wednesday, July 19, 200023 years ago
-
Date Issued
Tuesday, June 4, 200222 years ago
-
Inventors
-
-
Examiners
Agents
- Leatherwood Walker Todd & Mann, P.C.
-
CPC
-
US Classifications
Field of Search
US
- 030 151
- 030 155
- 030 158
- 030 159
- 030 160
- 030 161
-
International Classifications
-
Abstract
Spring-assisted folding knife designs having a coil spring, cable, and spool arrangement for pivoting a blade from a retracted position to an extended position. Activation of the spring system can be accomplished a pushbutton mounted on the side of the knife's handle, or through depression of a locking lever carried on the back side of the handle. Once moved to the extended position, the blade is automatically locked in that position through the pushbutton mechanism in one embodiment, or, in the other embodiment, through a liner lock.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to a folding knife having a spring-assisted blade opening mechanism.
The present invention includes a folding knife comprising a handle; a blade pivotally connected to the handle for movement between an extended position extending outwardly from the handle and a retracted position adjacent the handle; a spool connected to the blade for movement with the blade, the spool defining a plurality of attachment openings; and a spring connected to at least one of the attachment openings of the spool and to the handle, the spring urging the blade towards the extended position.
Folding knives are popular due to their compact size and portability. However, a potential drawback of certain folding knives is that they require two hands for use. One hand is required for holding the handle portion of the blade, while the other hand is necessary to withdraw the blade from its retracted position within the handle and move the blade to the extended, operable position.
Accordingly, it is desirable to have a folding knife wherein the blade can be opened using one hand. One such folding knife design is disclosed in Applicant's U.S. Pat. No. 5,815,927, issued Oct. 6, 1998, and entitled “Folding Knife With Actuatable Safety Locking Mechanism.” That design allows the user to extract blade from its retracted position within the handle by the user's engaging and pulling on ridges defined in a rear portion of the blade. A plunger mechanism having a coil spring facilitates opening of the blade, but the user is still required to pull on the ridges in order to move the blade through a selected range of motion and for the spring to assist the blade to move it to the extended position.
Providing a folding knife design wherein the blade may be opened using only one hand produces obvious advantages. The user is allowed to use one hand for holding, pulling, or pushing on the object to be cut while at the same time being able to withdraw the folding knife from his or her pocket, toolbox, or some other compartment and moving the blade to an extended, usable position. Another advantage is for disabled persons who may have only one arm or one functioning hand. Further, law enforcement and military personnel may find a folding knife which may be operated with one hand useful in performing their duties.
Numerous folding knife designs have been patented. For example, U.S. Pat. No. 273,858, issued to Korn, discloses a folding knife having a leaf-type spring for moving a blade to an extended position. U.S. Pat. No. 1,603,914, issued to Hermann, discloses a folding knife having a coil spring connected to a metal tape, which pulls the blade to a retracted position. U.S. Pat. No. 2,601,999, issued to Sly, discloses a foldable gaff hook having a similar opening mechanism. U.S. Pat. No. 2,407,897, issued to Newman also discloses a spring for pivoting blade open upon actuation of a locking lever. U.S. Pat. No. 698,080, issued to Treas, also discloses use of an actuating spring for pivoting a blade to an open position.
U.S. Pat. No. 4,535,539, issued to Friedman, et al, and U.S. Pat. No. 5,093,995, issued to Jan, disclose button release mechanisms for folding knives.
U.S. Pat. Nos. 4,893,409 and 5,964,035, issued Poehlmann, disclose folding knives having adjustment screws for adjusting the fit of the blade in the extended position. U.S. Pat. No. 1,065,863, issued to Carter, also discloses use of set, or an adjustment, screw.
SUMMARY OF THE INVENTION
It is, therefore, the principal object of this invention to provide a folding knife which can be opened by the user using only one hand.
Another object of the present invention is to provide a folding knife which opens automatically upon actuation of a release mechanism.
Still another object of the present invention is to provide a folding knife whereupon movement of the blade to the extended position causes the blade to be automatically locked in the extended position.
A still further object of the present invention is to provide a folding knife having a release member located on the back of the handle, such that depression thereof causes the blade to automatically move to the extended position.
A further object of the present invention is to provide a method of assembling a folding knife.
Another object of the present invention is to provide a method of extending a blade of a folding knife.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing, as well as other objects of the present invention, will be further apparent from the following detailed description of the preferred embodiment of the invention, when taken together with the accompanying specification and the drawings, in which:
FIG. 1
is a partial perspective and exploded view of a folding knife constructed in accordance with the present invention, wherein the blade is shown in an extended position;
FIG. 2
is a partial perspective view of the knife illustrated in
FIG. 1
, with the blade in an extended position;
FIG. 3
is a partial perspective view of the knife shown in
FIG. 1
, with the blade in an intermediate position between the extended and retracted positions;
FIG. 4
is a partial perspective view of the knife illustrated in
FIG. 1
, wherein the blade is illustrated in a retracted position;
FIG. 5
is a partial perspective view of an alternate embodiment of a knife constructed in accordance with the present invention, wherein the blade is illustrated in an extended position;
FIG. 6
is partial perspective view of the knife illustrated in
FIG. 5
, wherein the blade is in an intermediate position between the extended and retracted positions;
FIG. 7
is a partial perspective view of the knife illustrated in
FIG. 5
, wherein the blade is illustrated in a retracted position;
FIG. 8
is a side elevational view, with parts cut away, of the knife illustrated in
FIG. 5
;
FIG. 9
is a side elevational view, with parts cut away, of the knife illustrated in
FIG. 1
; and
FIG. 10
is a partial exploded view of the connector used in assembly of a knife constructed in accordance with the present invention and a clip for use in connection with such knife.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The accompanying drawings and the description which follows set forth this invention in its preferred embodiment. However, it is contemplated that persons generally familiar with folding knives will be able to apply the novel characteristics of the structures illustrated and described herein in other contexts by modification of certain details. Accordingly, the drawings and description are not to be taken as restrictive on the scope of this invention, but are to be understood as broad and general teachings.
Referring now to the drawings in detail, wherein like reference characters represent like elements or features throughout the various views, the folding knife of the present invention is indicated generally in the figures by reference character
10
.
Turning to
FIG. 1
, a folding knife
10
is shown having a blade, generally
12
, in an extended position. Blade
12
includes a cutting edge E. Handle, generally
14
, includes first and second portions, or sides, generally
18
,
20
. Right side
20
of handle
14
includes a recessed portion
22
which, together with left side portion
18
, serves to define a blade cavity
24
for seat of blade
12
, when blade
12
is in a retracted position, such as shown in FIG.
4
.
A fastener, or connector, generally
28
, is used to attach the rearward portion of sides
18
and
20
together. As more clearly shown in
FIG. 10
, connector
28
includes a male portion
30
and a female portion
32
. Female portion
32
includes a threaded channel
34
for receipt of a threaded sleeve
36
of male portion
30
. Sleeve
36
defines a cylindrical passage
40
for receipt of a projection
42
of a clip, generally
44
. Clip
44
is attached to handle
14
for use in retaining the knife to the user's pocket, backpack, boot, etc. Each of portions
30
,
32
include a head
48
, and each head includes an interior drive profile
50
for use with a standard driver such as an Allen wrench, or Phillips, blade, Torx, etc. driver. A screw
51
attaches clip
44
to handle
14
. As shown in FIG.
10
, profile
50
is of hexagonal shape and is mateable with a cooperating profile
52
, also of hexagonal shape on clip
44
. This feature will be discussed in more detail below.
Returning to
FIGS. 1 and 9
, blade
12
is locked in its extended position automatically once it arrives at such position by virtue of a coil spring
60
, urging a push button member, generally
62
, upwardly such that a locking disk
64
of push button
62
registers with an extended position scallop
66
defined in blade
12
. One end of spring
60
is held to push button
62
by a boss
67
on the bottom of pushbutton
62
. Blade
12
remains locked in this extended position until pushbutton
12
is depressed sufficiently, against the force of spring
60
, so that locking disk
64
no longer registers with scallop
66
, and the radiused end
68
of tang
61
of blade
12
may clear a bypass post
70
of pushbutton
62
as blade
12
is pivoted rearwardly as shown in
FIG. 3
towards blade cavity
24
. Pushbutton
62
moves within a pushbutton passage, generally
72
, as it is depressed by the user, and moved outwardly by spring
60
.
Blade
12
includes a stop profile
76
which engages with the stop
78
defined in handle portion
20
, and blade
12
is connected to handle
14
by means of a screw post arrangement, generally
80
. The screw post arrangement
80
includes a first screw portion
81
, which engages with left side
18
of handle
14
and a second screw portion (not shown) which engages with side
20
of handle
14
. One of the screw portions is a male configuration and the other a female to allow connection together, in a manner not unlike connector
28
. Blade
12
rotates with respect to the screw post arrangement
80
.
Fixedly connected to blade
12
is a spool member, generally
82
. Spool member preferably includes a threaded portion received in a corresponding threaded opening of blade
12
, neither being shown. It is to be understood, however, that spool
82
can be connected to blade
12
by other means such as a press-fit arrangement, epoxy, soldering, welding, etc. Spool
82
includes a bottom flange portion
84
and an upper flange portion
86
, each flange portion
84
,
86
having readily disposed openings
88
for receipt of a pin
90
. Upper flange
86
also includes a drive profile
92
, which could be hexagonal in shape, shown in
FIG. 1
, having six sides
94
.
Pin
90
is interconnected between openings
88
and serves as a post for receiving a loop of cable
96
, which connects spool member
82
to a coil spring, generally
98
. Cable
96
also forms a loop at a receiver eyelet of spring
98
, and cable
96
includes a clamp such as a metal crimped member, generally
99
, for forming the loops in cable
96
. The other end of coil spring includes an eyelet
100
attached to a post
104
, which is fixedly connected to side
20
of handle
14
.
FIG. 4
illustrates blade
12
in a retracted position, and locking disk
64
of pushbutton
62
is in registration with a retracted position scallop
108
defined in blade
12
. In the retracted position, it can be seen that cable
96
is wound about spool
82
, between flanges
84
and
86
, around the major portions of the periphery of spool
82
. To move blade
12
to an extended position, pushbutton
62
is depressed such that locking disk
64
no longer registers with scallop portion
108
. This causes blade
12
to immediately pivot outwardly to the extended position by virtue of the tension spring force applied by coil spring
98
, acting through cable
96
, which in turn pulls on pin
90
to rotate spool
82
in a clockwise motion, as shown in FIG.
4
.
Cable
96
is preferably steel cable and the blade is cutlery steel and handle can be a molded plastic, wood, metal or other materials.
FIG. 5
illustrates an alternate embodiment folding knife
210
which preferably utilizes the same coil spring
98
, cable
96
, and the spool
82
mechanism discussed above, and illustrated in FIG.
8
. However, folding knife
210
could also be a folding knife wherein the blade is opened manually and the spring, cable, spool combination eliminated.
Blade
213
of knife
210
is shown in
FIG. 5
in its extended position and is automatically locked in that position through use of a spring-biased liner lock member, generally
215
, which can be of conventional construction. Liner lock
215
includes a forward end
217
which engages with a rear flat edge
219
of blade
213
to thereby block blade
213
from pivoting rearwardly towards handle
214
. Any “slop” or “play” between blade
213
and handle
214
can be eliminated through use of adjustment screw
221
which is threadingly carried in the handle stop portion
223
. Blade
213
includes a blade stop flat
225
which may bear against adjustment screw
221
. Adjustment screw
221
is thus useful during initial manufacture of knife
210
to ensure blade
213
has little or no play when opened, and also, as knife
210
wears, adjustment screw
221
can be turned outwardly to eliminate any play which develops during wear.
To move blade
213
to the retracted position, liner lock
215
is depressed inwardly, towards right handle side portion
220
, such that edge
217
of liner lock
215
clears edge
219
of blade
213
.
FIG. 7
illustrates blade
213
in its retracted position. Blade
213
is held within the retracted position through use of a release member, generally
231
. Release member
231
extends along the back portion, generally
230
, of handle
214
, and preferably includes a lever
231
pivotally carried on an axle
233
fixedly connected to handle side portion
220
. Lever
231
includes a retention flat
235
which engages with a corresponding blade flat
237
defined on blade
213
. Retention lever
231
, and thus retention flat
235
, is urged towards blade flat
237
by means of a wire spring
239
. One end of wire spring
239
is fixedly attached to handle
214
by means of the insertion thereof into a cavity
241
. The free end of wire spring
239
contacts and urges upwardly the underside profile
243
of lever
231
. Thus, in order to release blade
213
from its retracted position, and for blade
213
to automatically move to its extended position, and assuming use of the coil spring, cable, spool, in combination discussed above, the rear portion
245
of lever
231
is depressed sufficiently for retention flat
235
of lever
231
to clear upstanding blade flat
237
. The abutment of blade stop
247
and lever end
235
prevent blade
213
from extending beyond the blade's extended position.
FIG. 8
illustrates coil spring
98
, cable
96
, and spool
82
in use with knife
210
.
An important feature of the folding knives
10
,
210
of the present invention is the assembly of the coil spring
98
, cable
96
, and spool
82
combination. Providing proper spring tension in this combination is essential for creating a smooth automatic opening of the blade. However, due to variations in manufacturing, spring tension, the characteristics of individual cables
96
, and overall build-up in manufacturing tolerances, some adjustment feature may be necessary. The plurality of openings
88
in spool
82
allow for such adjustment to be made. In order to provide proper tension, one of several opening pairs
88
defined in upper and lower flanges
84
,
86
of spool
82
can be selected for insertion of pin
90
, thereby allowing variations in the manufacture of components to be compensated for to yield uniformly operating knives on a production line basis.
Another important feature of assembling knives
10
,
210
is the clip
44
and connector
28
arrangement. Because the drive profile
50
of connector
28
and the cooperating profile
52
on clip
44
, projection
42
of clip
44
may be inserted into passage
40
of connector
28
during assembly, properly aligned with the handle, and held in place while a conventional driver (not shown) such as an Allen wrench, is used to drive the other of the male or female portion
30
,
32
, as the case may be, to tighten connector
28
together. This again allows for variances in components during manufacture and allows for the clip to always be properly aligned while the sides
18
,
20
are fastened together, or while a side (not shown) of knife
210
and right side
220
are fastened together.
From the foregoing it can be seen that the knife designs of the present invention offer unique features in assembly techniques.
While preferred embodiments of the invention have been described using specific terms, such description is for present illustrative purposes only, and it is to be understood that changes and variations to such embodiments, including but not limited to the substitution of equivalent features or parts, and the reversal of various features thereof, may be practiced by those of ordinary skill in the art without departing from the spirit or scope of the following claims.
Claims
- 1. A folding knife comprising:a handle; a blade pivotally connected to said handle for movement between an extended position extending outwardly from said handle and a retracted position adjacent said handle; a spool connected to said blade for movement with said blade, said spool defining a plurality of attachment openings; and a spring connected to at least one of said attachment openings of said spool and to said handle, said spring urging said blade towards said extended position.
- 2. A folding knife as defined in claim 1, wherein said plurality of attachment openings are radially spaced from one another.
- 3. A folding knife as defined in claim 1, wherein said spool includes a six-sided drive profile.
- 4. A folding knife as defined in claim 1, wherein said spool includes a drive profile.
- 5. A folding knife as defined in claim 1, wherein said handle defines a blade cavity for receipt of said blade when said blade is in said retracted position.
- 6. A folding knife as defined in claim 1, wherein said spool is fixedly attached to said blade.
- 7. A folding knife as defined in claim 1, further comprising an elongated member connected between said spring and said spool.
- 8. A folding knife as defined in claim 1, wherein said handle includes a first portion and a second portion and further comprising a connector extending through said first and second handle portions, said connector defining an opening therethrough having a drive profile.
- 9. A folding knife as defined in claim 8, further comprising a clip connected to said handle, said clip having an engagement portion for receipt in said opening of said connector, and said engagement portion defining a cooperating profile for cooperating with said drive profile of said connector.
- 10. A folding knife as defined in claim 9, wherein said drive profile of said opening of said connector and said cooperating profile of said engagement portion are hexagonal in cross-section.
- 11. A folding knife as defined in claim 1, further comprising a release member connected to said handle for selectively allowing movement of said blade from said retracted position under the urging of said spring.
- 12. A folding knife as defined in claim 1, further comprising a push button member connected to said handle for selectively allowing movement of said blade from said retracted position under the urging of said spring.
- 13. A folding knife as defined in claim 1, wherein said handle includes a first side portion, a second side portion, a blade opening between said first and second side portions, and a back portion opposite said blade opening, and further comprising a release member connected to said back portion of said handle for selectively allowing movement of said blade from said retracted position under the urging of said spring.
- 14. A folding knife as defined in claim 13, wherein said blade defines a retention profile and wherein said release member contacts said retention profile to retain said blade in said retracted position.
- 15. A folding knife as defined in claim 1, wherein said handle includes a first side portion, a second side portion, a blade opening between said first and second side portions, and a back portion opposite said blade opening, and further comprising a release lever connected to said back portion of said handle for selectively allowing movement of said blade from said retracted position under the urging of said spring.
- 16. A folding knife as defined in claim 1, wherein said handle includes a first side portion, a second side portion, a blade opening between said first and second side portions, and a back portion opposite said blade opening, and further comprising a release lever pivotally connected to said back portion of said handle for selectively allowing movement of said blade from said retracted position under the urging of said spring.
- 17. A folding knife comprising:a handle; a blade pivotally connected to said handle for movement between an extended position extending outwardly from said handle and a retracted position adjacent said handle; a spool connected to said blade for movement with said blade, said spool defining a plurality of attachment openings; and a spring linked to at least one of said attachment openings of said spool and to said handle, said spring urging said blade towards said extended position.
- 18. A folding knife comprising:a handle; a blade pivotally connected to said handle for movement between an extended position extending outwardly from said handle and a retracted position adjacent said handle; a spool connected to said blade for movement with said blade, said spool defining a plurality of attachment openings; and means for connecting a spring to at least one of said attachment openings of said spool and to said handle, said spring urging said blade towards said extended position.
US Referenced Citations (21)
Foreign Referenced Citations (2)
Number |
Date |
Country |
28765 |
Jan 1884 |
DE |
435488 |
Oct 1911 |
FR |