WO2005090012A1

WO2005090012A1 - Knife with a handle integrating a retractile rope cutter

Info

Publication number: WO2005090012A1
Application number: PCT/IT2004/000144
Authority: WO
Inventors: Maurizio Castrati
Original assignee: Extrema Ratio S.A.S. Di Mauro Chiostri E C.
Priority date: 2004-03-23
Filing date: 2004-03-23
Publication date: 2005-09-29

Abstract

A knife comprising a handle (1) with a head and a butt (4), and at least one main blade (2) that extends or can be extended from the head, characterized in that the butt (4) comprises a fixed blade (10), and the handle comprises a beak-shaped extension (5) comprising a movable blade (9). The extension (5) is joined to the butt (4), so as to rotate between an extracted position sideways of the handle (1), in which the blades (9, 10) form a V-shaped cutting front open toward the head of the handle, and a retracted position in which the front is closed, and the extension (5) and butt (4) cover the edges of the relative blades (9, 10), rendering them unable of cutting. On the butt (4) there are also placed means for stopping (14, 15) the extension (5) in the extracted position, and means for locking (16, 17) the same in the retracted position, the locking means (16, 17) capable of being manually releasable by the user.

Description

KNIFE WITH A HANDLE INTEGRATING A RETRACTILE ROPE CUTTER DESCRIPTION Field of the Invention The present invention refers to the cutlery field. In particular, it concerns a new model of knife for sport and military use. Description of the Background Art The need to provide for the cutting of a rope, a cord, a strap, a safety belt or any other similar flexible wire or band shaped element, in a clean and immediate manner, occurs quite frequently both in military and sport uses (hiking and mountaineering to name a few examples) . Obviously, common knives may respond to such need. Nevertheless, conventional cutting tools do not always prove to be completely satisfactory. With a normal blade it is in fact generally necessary to use both hands, one for cutting, the other for holding the rope firmly and/or arranging it in tension. In certain situations, particularly in case of urgency/emergency, this clearly constitutes a problem, which is made worse if the rope is not easily accessible, and thus even the exercise of a suitably intense and precise cutting action becomes difficult. In case of switchblade knives, a further obstacle derives from the fact that the extraction of the blade may be relatively laborious, lengthening the times of intervention. Finally, safety is compromised by the use of an entirely exposed blade, which operates in proximity to the user's other hand. These problems may be well exemplified by referring to a circumstance that occurs in case of instructor- assisted deployment skydiving jumps. It may occur that the parachutist, after having launched outside the airplane fuselage, in case of an accidental, unsuccessful drawing of the parachute, is left hanging to the airplane by the static line, a situation from which the parachutist may only escape with the operation of the emergency parachute. However, this may only take place after the rope has been cut by the jump instructor in charge of operations on board the airplane. Once it is assured that the parachutist has not lost consciousness, the director must perform the cut with the utmost rapidity and safety, to free the parachutist from a situation that, clearly, is extremely dangerous. The rope, extending outside the fuselage, is moreover not easily accessible, not even with a single hand. Summary of the Invention The object of the present invention is to overcome the above-described drawback, providing a new knife model that, through an original combination of components, facilitates and renders safer the cutting operations of a rope, cord, belt or any other similar flexible wire or band-shaped element, in particular in conditions of urgency and/or emergency. Such object is achieved with the knife according to the present invention of which the essential characteristics are defined in the first of the appended claims . Brief Description of the Drawings Characteristics and advantages of the knife with handle integrating a retractile rope-cutter according to the present invention will be apparent from the following description of one of its embodiments, given as purely exemplifying and non-limiting, with reference to the attached drawings, in which: - figure 1 is a lateral view of a knife according to the invention, with the rope-cutter in retracted, or off- work, position; - figure 2 is a lateral view of the knife, analogous to that of figure 1, with the rope-cutter in extracted, or use, position; - figure 3 is again a lateral view of the knife, from the opposite side with respect to the one of the previous figures and with the rope-cutter once again in retracted position; - figure 4 is a detail of the handle of the knife, in the zone of the rope-cutter, in lateral view and in retracted position as in figure 1, with two areas in cross section taken along line IV-IV of subsequent figure 5; and - figure 5 is a view of the detail of figure 4 from the direction of the knife edge, i.e. rotated by 90° with respect to the view of the previous figure, with an area in cross section taken along line V-V of said figure. Detailed Description of the Invention With reference to the above figures, the knife according to the invention comprises a handle 1, and a blade 2 extending from a head 20 of the handle in a totally conventional manner. The blade 2 is retractile in the example and shown in figures 1-3 in the extracted configuration. The handle 1 comprises two overlaying grips la, joined in a spaced manner so as to form, on the cutting edge side of the knife, a longitudinal seat (not visible in the figures) , intended to hold the blade 2 in the retracted configuration. A clip 3 is fastened to one of the two grips la for hooking the knife to a sheath, or more simply to a string or belt. The butt of the handle 1, indicated at 4, has a curved shape towards one side of the handle and ends with a rounded tip 4a, forming a recess 6 in said side. A beak- shaped extension 5 is joined at the rounded tip 4a of the butt 4, and more precisely at a pivot 7 which, as seen in figure 4, extends between the two grips la. The extension 5 directs its own point towards the head 20 of the handle 1. In fact, as will be made clearer further on, the extension 5 is angularly movable, lying on the same plane as the blade 2, between an extracted position (figure 2), in which it forms an acute angle with the butt 4, preferably at about 60°, and a retracted or off-work position, in which it joins the butt 4, placing itself in the recess 6 and, partially, in a space 8 defined between the two grips la. In particular, as is clearly visible from the figures 4 and 5, in said retracted position the point 5a of the extension 5 becomes hidden inside an enlarged section 8a of the space 8, at the base of the butt 4. A movable blade 9 extends along a side of the extension 5, facing toward the butt 4. A fixed blade 10 is instead supported by one of the grips la, such that it partially intercepts the recess 6, overlaying extension 5 and in contact with it. In particular, when the extension 5 is in the extracted position, the movable blade 9 and the fixed blade 10 form a V-shaped cutting front, directed towards the handle 1 and with an opening substantially equal to the above-cited angle. With the movement of the extension 5 towards the retracted position, the movable blade 9 slides over the fixed blade, progressively closing the cutting front. Finally, in the retracted position, the edge of each blade results completely covered, and therefore rendered unable of cutting, by the other blade, as is clearly visible from figures 1 and 3. Elastic return means oppose the movement of the extension 5 from the extracted position to the retracted position, and conversely assist the movement in the opposite direction. As is clearly visible in figure 4, in the illustrated example such means consist in a helical spring 11, placed between the grips la, and therefore in the space 8. A first end of the spring 11 is set within the base section 8a of the space 8, hooked to a pivot 12 integral with the grips la. The other end is instead situated in correspondence with the tip 4a of the butt 4, and is joined by way of a bracket 13 to the base 5b of the extension 5, behind the pivot 7. Said base 5b of the extension 5 comprises a side wall 14, for abutment on a stop 15 which extends integrally from the grips la, in proximity to the pivot 7. The abutting occurs in both the retracted and extracted position, although in two different points of the wall 14. In order to lock the extension 5 in the retracted position, opposing the action of the spring 11, a flat spring 16 is provided, projecting from the inner face of one of the two grips la within the base section 8a of the space 8 such that it engages the point 5a of the extension 5, appropriately shaped to the purpose. For allowing the spring 16 to re-enter the relevant grip la, thereby completely clearing the space 8 in order to become disengaged from the extension 5, a button 17 is slidingly inserted into the other grip la and is accessible on the outside of the handle 1. The pressure of the button 17, even though the same does not project out of the handle, is permitted thanks to a housing 18 formed in the handle, at the centre of which the button emerges . In use, the knife according to the invention may accomplish its conventional functions, i.e. those ascribable to the blade 2 (or to other blades/devices possibly present in case of a multifunction knife) , with the extension 5 in the retracted position, and therefore unable of causing any trouble with the manipulation of the handle 1. In case of need, that is in case that the cord, rope or similar wire or band shaped element must be cut, the user will operate the button 17 with a light pressure of the thumb of the hand which grips the handle, a particularly favorable and ergonomic movement due to the location of the button itself. With the opening of the extension 5 to the extracted position, controlled by the spring 11, the two blades 9, 10 are exposed. The cutting front is thus available for cutting, which will occur by hooking the rope between the extension 5 and the butt 4 and exercising a resolute traction on the plane perpendicular to the rope axis. The V shape of the cutting front permits providing to the cut in a faster, easier and safer manner with respect to the normal procedure with a simple straight blade. In fact, the engagement of the extension 5 with the rope may initiate in a rapid and precise manner, also in case of rope far away from the user or in any case difficult to reach. The cutting may occur by simply exerting a resolute traction, even without holding the rope firmly in the other hand, with clear advantages in terms of operation speed and safety. It may not be ignored that in case of a switchblade knife, which represents the preferred utilization of the present invention, the rope cut may be carried out without extracting the main blade and therefore, here too, with the advantage of swiftness and with minor risks of injury. When the knife is not in use, it may be placed back in the relevant sheath with butt 4 directed downwards, i.e. closed and protected by the sheath itself. This will suffice in avoiding the possibility of accidental openings of the extension 5. However, the invention may be also applied with knives of different typologies, incompatible with the arrangement just mentioned and for which therefore there may be the need for supplementary safety devices, according to what is in any case obvious for one skilled in the art. Again, in case of a switchblade knife, the double grip structure of the handle 1, already adopted to define the housing seat for one or more of the main blades, is advantageously exploited also for defining the space 8 which holds the extension 5 in the retracted position. On the contrary, in case of a fixed main blade, the space 8 will be formed on purpose, on one or the other of the two sides of the handle. To assist the manual opening of the extension 5, if oxides, dirt or foreign bodies in general hinder to some extent the automatic opening, a grip slot 19 may be advantageously formed in proximity to the outer edge of the extension and with curved shape along it. The angle of the extension 5 and of the butt 4 may be varied according to the specific use intended for the knife, and depending on its size. Also the configuration of the elastic return means joined to the extension 5, and the locking mechanism of the same in the retracted position, may be different from those illustrated as example. More generally, even though at the cost of a lesser convenience of use, the invention may be reduced to practice even without elastic return means, the presence of stop means in the extracted position being sufficient along with the locking means in the retracted position, releasable by a user. Other variants and/or modifications may be brought to the knife with a handle integrating a retractile rope- cutter according to the present invention without for this reason departing from the scope of protection of the invention itself.

Claims

1. A knife comprising a handle (1) with a head (20) and a butt (4) and at least one main blade (2) that extends or can be extended from said head (20) , characterized in that said butt (4) comprises a fixed blade (10) , and in that said handle (1) comprises a beak-shaped extension (5) supporting a movable blade (9) , said extension (5) being joined to said butt (4) , so as to rotate between a drawn position extracted sideways from said handle (1) in which said fixed blade (10) and said movable blade (9) form a V- shaped cutting front open towards said head (20) , and a retracted position in which said cutting front is closed, and said extension (5) and said butt (4) cover the edge of the respective blades (9, 10) , rendering them unable of cutting, said butt (4) further comprising stop means (14, 15) of said extension (5) in said retracted position, and locking means (16, 17) of the same in said retracted position, said locking means (16, 17) being manually releasable by the user.

2. Knife according to claim 1, wherein said butt (4) has a curved shape towards the extraction side of said extension (5) .

3. Knife according to claim 1 or 2 , wherein said V-shaped cutting front has an opening of about 60°.

4. Knife according to any of the previous claims, comprising elastic return means (11) for hindering the movement of said extension (5) from said extracted position to said retracted position, and conversely to assist the movement in the opposite direction.

5. Knife according to any of the previous claims, wherein said butt (4) forms a space (8) which at least partially houses said extension (5) in said retracted position, said locking means (16, 17) being placed in said space (8) .

6. Knife according to claim 5, wherein said elastic return means (11) are placed within said space (8) and comprise a helical spring (11) with a first end connected to said butt (4) within said space (8) and the other end joined to said extension (5) , behind the relative axis of rotation (7) .

7. Knife according to claim 5 or 6, wherein said locking means (16, 17) comprise a movable element (16) , projecting inside said space (8) in order to engage itself with said extension (5) , and movable orthogonally to the plane of rotation of said extension (5) to clear said opening (8) , the movement being controlled by actuator means (17) , which can be operated from a lateral side of said handle (1) .

8. Knife according to claim 7, wherein said movable element is a flat spring (16) placed on a face of said space (8) , said actuator means comprising a button (17) slidingly inserted in said handle (1) and accessible on its outside.

9. Knife according to claim 8, wherein in the outside of said handle (1) a housing (18) is formed, at the centre of which said button (17) emerges.

10. Knife according to any of the claims from 5 to 9, wherein said extension (5) comprises, in proximity to the relative axis of articulation (7) , a side wall (14) for abutment on a stop (15) which extends within said space (8) , said wall (14) being shaped so that it abuts on said stop (15) both in said retracted position and in said extracted position.

11. Knife according to any of the claims from 5 to 10, wherein said handle is formed by a couple of grips (la) joined in a spaced manner, between which said space (8) is defined.

12. Knife according to any of the previous claims, where said butt (4) ends with a rounded tip to which said extension (5) is connected, and forms on the extraction side of the same a recess (6) which is partially intercepted by said fixed blade (10) , said extension (5) with said movable blade (9) partially overlaying said fixed blade (10) in contact therewith.

13. Knife according to any of the claims from 4 to 12, wherein a grip slot (19) is formed in said extension (5) in order to assist the manual opening in case the automatic opening is obstructed.