Knife with blade exit actuated by a movable handle

Abstract

Knife provided with a body (1) extending along a longitudinal axis (A) and enclosing a blade holder (2) equipped with a blade (3) for which the blade holder is maneuverable along said longitudinal axis to extend the blade from the body on a front side (1a) of said body by means of a handle (4) maneuverable angularly relative to the body of the knife and retract it under the action of a return spring (10), said knife comprising a connecting rod device, configured to transform an angular movement of the handle (4) into longitudinal movement of the blade holder (2), comprising at least four connecting rods (5, 6, 7, 8) articulated to each other and guided between the knife body and the handle so as to produce a reduction in the output stroke of the blade relative to the rotation of the handle.

Description

Technical field

[0001] The invention relates to the field of knives comprising a blade mounted to slide longitudinally in a knife body and extracted from a knife body longitudinally under the action of a handle which can rotate about an axis relative to the knife body. Prior art

[0002] Document FR2 552 008 A1 discloses a cutter-type knife comprising a rotating trigger and provided with a thrust part on an inclined ramp of a blade holder to longitudinally protrude the blade from the front of the knife. This device does not allow for a significant blade exit stroke, the latter being limited by the angle of the ramp and the stroke of the handle.

[0003] Documents US 4,713,885 B2, US 6,813,833 B2 and US 7,322,110 B2 provide knives with longitudinal blade exit for which a system with two connecting rods forming the two arms of a compass whose spacing pushes a blade holder so as to control a longitudinal exit of the blade under the action of a pivoting handle. These devices make it possible to multiply the exit length of the blade in relation to the stroke of the handle and thus increase the amplitude of exit of the blade. Technical problem

[0004] However, these known solutions do not allow for a blade output amplitude comparable to that obtained with a simple pusher placed on the knife body and movable longitudinally to operate a blade holder. It is therefore desirable to be able to further increase the blade output amplitude. Statement of the invention

[0005] In view of this situation, the present disclosure proposes a knife provided with a body extending along a longitudinal axis and enclosing a blade holder equipped with a blade for which the blade holder is maneuverable along said longitudinal axis to extend the blade from the body on a front side of said body by means of a handle that can be maneuvered angularly relative to the body of the knife and retract it under the action of a return spring, the knife comprising a connecting rod device, configured to transform an angular movement of the handle into a longitudinal movement of the blade holder, comprising at least four connecting rods articulated to each other and guided between the knife body and the handle so as to produce a reduction in the extension stroke of the blade relative to the rotation of the handle.

[0006] The characteristics set out in the following paragraphs correspond to embodiments which can be implemented independently of one another or in combination with one another:

[0007] According to one embodiment, a first articulation is made between a rear part of the body of the knife and a first end of a first connecting rod, a second articulation is made between a second end of the first connecting rod and a first end of a second connecting rod, a third articulation is made between a second end of the second connecting rod and a first end of a third connecting rod, a fourth articulation is made between a second end of the third connecting rod and a first end of a fourth connecting rod, for which the second end of the fourth connecting rod is provided with a fifth articulation with the blade holder and for which the second and fourth articulation are configured to slide while bearing against an internal face of the handle while the third articulation is configured to slide on a part of the body of the knife.

[0008] The body of the knife advantageously comprises a base relative to which the blade holder slides and side walls between which the blade holder moves.

[0009] The third articulation 61 may comprise bosses 62 which slide in first grooves 12 made in said side walls of the body of the knife, the first grooves constituting said part of the body of the knife on which the third articulation slides.

[0010] Advantageously, the first grooves can constitute first ramps inclined relative to the longitudinal axis of the knife according to a slope of increasing inclination from the rear to the front of the knife relative to the longitudinal axis of the knife.

[0011] The fifth articulation may comprise internal pins received in second grooves on the blade holder, transverse to said longitudinal axis and parallel to said side walls.

[0012] The fifth articulation may also comprise external pins which slide in third grooves made in said side walls of the body of the knife, said third grooves forming second ramps inclined according to a slope of increasing inclination from the rear to the front of the knife relative to the longitudinal axis of the knife.

[0013] The third grooves may extend over a length of the blade's exit stroke.

[0014] According to a particular embodiment, the inclination of the first ramps is more pronounced than the inclination of the second ramps.

[0015] The handle is conveniently hinged to the front of the knife body.

[0016] The blade output stroke is greater than 2 times the stroke of the handle element and preferably in the order of 2.5 times to 3 times the stroke of the handle element.

[0017] According to a particular embodiment, the knife is provided with a device for holding the blade in the blade holder comprising a lug mounted on a spring tab and a device for releasing the blade comprising a pusher provided with a rib for bearing on a free end of said tab and positioned so as to allow the blade to be released from the blade holder by pushing on said free end, producing a twisting of said tab and a release of the lug from a hole in the blade when the knife is in a blade exit position. Brief description of the drawings

[0018] Other characteristics, details and advantages of the invention will appear on reading the detailed description below of non-limiting exemplary embodiments, and on analyzing the appended drawings, in which: [ Fig. 1A], [Fig. 1B] show an example of a knife according to the present disclosure in perspective, respectively blade retracted and blade extended; [ Fig. 2 ] shows an exploded view of a knife according to the present disclosure; [ Fig. 3 ] shows an interior view of a knife according to the present disclosure; [ Fig. 4 ] shows a detail of a safety locking device for a handle; [ Fig. 5 ] shows a detail of a blade holder with blade lock. Description of the embodiments

[0019] The following drawings and description contain elements which may not only serve to better understand the present invention, but also contribute to its definition, where appropriate.

[0020] Reference is now made to the Figures 1A and 1B which represent a knife according to the invention with the blade retracted into Figure 1A and blade out in Figure 1B. The knife comprises a knife body 1, a pivoting handle 4 articulated on pins 15 on a front part of the knife and a blade 3 which comes out and reenters along a longitudinal axis A of the knife via the front 1a of the knife. To exit the blade, an operator presses the pivoting handle 4 which can be maneuvered angularly relative to the body of the knife on the body 1 which causes the blade to exit by means of the mechanism described in particular in Figures 2 and 3 .

[0021] According to the Figure 3 in particular, the body 1 extending along the longitudinal axis A and containing a blade holder 2 equipped with the blade 3 and maneuverable along said longitudinal axis to remove the blade from the body on the front side 1a of said body by means of the handle 4.

[0022] The blade holder slides on a base 1c of the knife and between side walls 1d, 1e of the blade holder parallel to a plane of the blade holder.

[0023] To do this, the knife comprises a connecting rod device, between the handle and the blade holder, this connecting rod device being configured to transform an angular movement of the handle 4 into a longitudinal movement of the blade holder (2).

[0024] According to the example shown, the connecting rod device comprises four connecting rods 5, 6, 7, 8 articulated to each other and guided between the knife body 1 and the handle 4 so as to produce a reduction in the output stroke of the blade relative to the rotation of the handle. This number of four connecting rods is a compromise between the desired reduction, the complexity of the mechanism and the difficulty in pressing the handle depending on the friction between the various elements of the mechanism.

[0025] To retract the blade, the operator releases the handle and the blade holder retracts into the body of the knife 1 under the action of a return spring 10.

[0026] The connecting rod device shown more particularly in Figures 2 and 3 is such that a first articulation 51 is produced between a rear part 1b of the body of the knife and a first end of a first connecting rod 5. To do this, as shown in Figure 2 , the rear of the body of the knife has housings 14 for first pins 53 of said first articulation.

[0027] A second articulation 52 is produced between a second end of the first connecting rod 5 and a first end of a second connecting rod 6 and a third articulation 61 is produced between a second end of the second connecting rod 6 and a first end of a third connecting rod 7. This third articulation comprises second pins coming from the second connecting rod and turned towards the inside of the knife to fit into housings of the third connecting rod and is configured to slide on a part of the body of the knife.

[0028] According to the example, this third articulation further comprises bosses 62 which slide in first grooves 12 made in said side walls 1d, 1e of the body of the knife. A configuration according to which the third articulation would slide against the bottom of the knife would be possible within the framework of the present disclosure but would be less effective because according to the embodiment shown, the first grooves 12 constituting said part of the body of the knife on which the third articulation slides and form first ramps inclined relative to the longitudinal axis A of the knife according to a slope of increasing inclination from the rear to the front of the knife relative to the longitudinal axis of the knife which improves the progressiveness of the movement of the articulation and makes the effort necessary to press on the handle more homogeneous than if the guidance of the articulation were parallel to the longitudinal axis.

[0029] Still referring to the Figures 2 and 3 , a fourth joint 71 is made between a second end of the third link 7 and a first end of a fourth link 8 and the second end of the fourth link 8 is provided with a fifth joint 81 with the blade holder.

[0030] More particularly shown in Figure 3 , while the third joint 61 is configured to slide on a part of the body of the knife, the second and fourth joints 52, 71 are configured to slide in contact with an inner face 4a of the handle 4 when the operator presses on the handle 4.

[0031] The connecting rod device finally comprises a fifth articulation 81 connecting the fourth connecting rod 8 and the blade holder and to do this, a second end of the fourth connecting rod comprises third pins also called internal pins 82 which are received in housings of the blade holder. These housings are constituted here by second grooves 21 on the blade holder, transverse to said longitudinal axis and parallel to said side walls 1d, 1e which allows said fifth articulation to rise in the knife when the connecting rod device is extended while pressing on the handle.

[0032] To improve the support of the rise of this articulation, the latter comprises fourth pins also called external pins 83 which slide in third grooves 13 made in said side walls of the body of the knife, said third grooves 13 forming second ramps inclined according to a slope of increasing inclination from the rear to the front of the knife relative to the longitudinal axis A of the knife. The third grooves 13 extend over a length of the blade's exit stroke and the curvature of the ramps corresponds to the stroke of the internal pins 82 in the grooves 21 of the blade holder.

[0033] According to the example, the inclination of the first ramps 12 is more pronounced than the inclination of the second ramps 13 and the stroke of the first ramps 12 is shorter than the stroke of the second ramps 13.

[0034] A knife according to any preceding claim wherein the blade output stroke is greater than 2 times the stroke of the handle member and preferably of the order of 2.5 times to 3 times the stroke of the handle member.

[0035] The knife as represented in Figure 2 comprises, for attaching the return spring 10, a tenon 22 on the blade holder and a tenon 92 on an attached rear cover which is fixed to the body by a groove 16, tongue 91 device, the tongues being inserted by force between the side walls 1d, 1e of the body of the knife.

[0036] According to the Figure 5, a lock can lock the handle in the position separated from the body, that is to say in the retracted blade position. The lock being in the form of a latch 41 moving laterally to release or block the movement of the handle relative to the rear cover by cooperating with a groove provided with a vertical part 92 in which the latch can slide and a stop part 93 in which the latch 41 can lock when the handle is released and the latch is pushed laterally.

[0037] According to the Figure 5the knife comprises a device for holding the blade in the blade holder comprising a lug 24 which fits into a hole 31 in the blade 3. The lug, which may have the form of a journal with an upper face at least partially inclined, is mounted on a spring tab 23. The tab comprises a free end 26 directed towards the bottom of the body 1 and a blade release device comprising a pusher 11 provided with a rib 26 is positioned on the body of the knife so as to allow the blade to be released from the blade holder by pushing on said free end 26, which produces a twisting of the tab 23 and a release of the lug 24 from the hole 31 in the blade, when the knife is in a blade exit position. Industrial application

[0038] The invention can be applied in particular to knives known under the English name “cutter”

[0039] The invention is not limited to the examples described above, only by way of example, but it encompasses all the variants that a person skilled in the art may envisage within the framework of the protection sought.

Claims

1. Knife provided with a body (1) extending along a longitudinal axis (A) and containing a blade holder (2) equipped with a blade (3) for which the blade holder is maneuverable along said longitudinal axis to remove the blade from the body on a front side (1a) of said body by means of a handle (4) maneuverable angularly relative to the body of the knife and retract it under the action of a return spring (10), characterized in that it comprises a connecting rod device, configured to transform an angular movement of the handle (4) into a longitudinal movement of the blade holder (2), comprising at least four connecting rods (5, 6, 7, 8) articulated to each other and guided between the knife body and the handle so as to produce a reduction in the output stroke of the blade relative to the rotation of the handle.

2. Knife according to claim 1, for which the body of the knife comprises a base (1c) relative to which the blade holder (2) slides and side walls (1d, 1e) parallel to a plane of the blade holder and between which the blade holder moves.

3. Knife according to claim 1 or 2, for which a first articulation (51) is made between a rear part (1b) of the body of the knife and a first end of a first connecting rod (5), a second articulation (52) is made between a second end of the first connecting rod (5) and a first end of a second connecting rod (6), a third articulation (61) is made between a second end of the second connecting rod (6) and a first end of a third connecting rod (7), a fourth articulation (71) is made between a second end of the third connecting rod and a first end of a fourth connecting rod (8), for which the second end of the fourth connecting rod (8) is provided with a fifth articulation (81) with the blade holder and for which the second and the fourth articulation (52,71) are configured to slide while pressing against an internal face (4a) of the handle (4) while the third articulation (61) is configured to slide on a part of the body of the knife., 4. Knife according to claim 3, wherein the third articulation (61) comprises bosses (62) which slide in first grooves (12) made in said side walls (1d, 1e) of the body of the knife, the first grooves (12) constituting said part of the body of the knife on which the third articulation slides and forming first ramps inclined relative to the longitudinal axis (A) of the knife according to a slope of increasing inclination from the rear to the front of the knife relative to the longitudinal axis of the knife.

5. Knife according to claim 3 or 4, for which the fifth articulation (81) comprises internal pins (82) received in second grooves (21) on the blade holder, transverse to said longitudinal axis and parallel to said side walls (1d, 1e), and comprises external pins (83) which slide in third grooves (13) made in said side walls of the body of the knife, said third grooves (13) forming second ramps inclined according to a slope of increasing inclination from the rear to the front of the knife relative to the longitudinal axis (A) of the knife.

6. Knife according to claim 5 wherein the third grooves (13) extend over an exit stroke length of the blade.

7. Knife according to claims 4 and 5, wherein the inclination of the first ramps is more pronounced than the inclination of the second ramps. ​8. Knife according to any one of the preceding claims, wherein the handle (4) is hinged on the front of the body of the knife.

9. Knife according to any one of the preceding claims for which the output stroke of the blade is greater than 2 times the stroke of the handle element and preferably of the order of 2.5 times to 3 times the stroke of the handle element.

10. Knife according to any one of the preceding claims comprising a device for holding the blade in the blade holder comprising a lug (24) mounted on a spring tab (23) and a device for releasing the blade comprising a pusher (11) provided with a rib (25) for bearing on a free end (26) of said tab (23) and positioned so as to allow release of the blade from the blade holder by pushing on said free end (26) producing a twisting of said tab (23) and a release of the lug from a hole (31) of the blade when the knife is in a blade exit position.

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