This invention relates to the field of pocket knives, also known as clasp knives, pen-knives, or Swiss knives. In particular, the invention relates to multifunctional pocket knives having multiple utility blades and/or attachments.

BACKGROUND

Pocket knives having multiple blades and attachments are well known in the prior art. European patent application EP1 195230, for example, discloses a multifunctional pocket knife having multiple blades and attachments such as pliers, detachable screwdriver bits, knife blades, tin-opener, bottle opener etc.

Also known in the prior art are pocket tool kits, such as might be used by cyclists for small bicycle repairs when on the road. These pocket tool kits may include wrenches (the common American term "wrench" is used in this application instead of the British equivalent term "spanner"). British patent application GB0026040, for example, describes a multi-tool in which wrench tools of different sizes are combined in one compact combination unit.

WO08003817 and US7334502 describe multipurpose tools which combine an adjustable wrench with other tools. The resulting combinations are bulky and heavy, however, and have all the disadvantages of adjustable wrenches, which lack mechanical rigidity, and which become jammed easily.

German patent application DE3740374 discloses a multi-purpose blade for a pocket-knife, which combines the functions of saw, bottle-opener, screw-driver, nail-remover, can-opener and wire-stripper. The blade of

DE3740374 also comprises an elongated opening with non-parallel sides, which can be used to gain a rotational purchase on screw heads, nuts or bolt heads which require tightening or loosening. One of the long sides of the elongated opening is equipped with teeth which are designed to improve the grip on the object being rotated. The blade of DE3740374 could in principle be used to undo projecting screws, nuts or bolt heads of round or polygonal cross- section, but it has significant disadvantages. Firstly, the user must maintain a longitudinal force on the knife blade against the screw head, in order to ensure that the screw head is well gripped in the tapered opening, while he

simultaneously applies the desired turning force on the screw head. If the user's hand slips in the longitudinal direction while he is pushing on the screw head, his hand will slide on to the saw edge of the blade and be injured.

Secondly, the teeth on the inside of the elongated opening will inevitably mark or damage the object being rotated. Thirdly, the length of the opening in the blade reduces the structural strength of the blade, and therefore reduces the amount of force which can be exerted on the object to be rotated without distorting or breaking the blade.

It is thus an object of the invention to provide a pocket knife which overcomes the above and other problems with the prior art. In particular, the invention aims to provide a pocket knife which enables a user to exert a greater rotational force on a nut, screw or bolt head while achieving a tighter grip on the nut or bolt head, and while reducing the risk of injury to the user or damage to the pocket knife. Another object of the invention is provide such a pocket knife but which is less bulky and less heavy.

In order to overcome these and other problems with the prior art pocket knives, the invention envisages a pocket knife comprising a knife body and a knife blade, the knife blade being housed in the knife body when the knife blade is in a closed state, and displaced outward from the knife body when the knife blade is in an opened state, the knife blade comprising an outer edge surrounding a substantially planar inner region, the outer edge including a cutting edge portion, the knife blade comprising at least one wrench socket hole formed through the inner region of the knife blade, the or each wrench socket hole having a regular polygonal or regular multipoint shape for fitting in rotational driven engagement around a polygonal or multipoint nut, screw head or bolt head.

By implementing the wrench sockets as individual holes in the knife blade, the need for a separate wrench tool to be included in the pocket knife is eliminated. Furthermore, by implementing the individual wrench sockets as holes within the interior region of the knife blade, and forming them in the shape of the nut or bolt head to be turned (eg a regular hexagon), the strength of the wrench socket is greatly increased when compared with a wrench tool with an open socket, such as might be achieved by machining a partial hexagon shape into the edge of a flat metal plate.

According to one variant of the pocket knife of the invention, the knife is further provided with interchangeable tool bits having a cross section corresponding to the cross-sectional shape of the at least one wrench socket hole. The knife may also comprise storage means for holding one or more of the interchangeable tool bits. Alternatively, the bits may be stored separately from the knife, and the knife itself has no bit storage means. The knife body comprises two opposite lateral faces, and at least one of said lateral faces may comprising a regular polygonal or multipoint hole for receiving one of said tool bits in a rotational drive configuration.

According to another variant of the pocket knife of the invention, the knife blade comprises a plurality of wrench socket holes formed through the inner region of the knife blade. The wrench socket holes may be formed as holes of different shapes and/or sizes. For example, the blade may include common sizes of hexagonal wrench holes (eg 10mm, 13mm), Torx ^® socket holes, 12-point socket holes etc.

According to a further variant of the invention, the plurality of wrench socket holes may include a first wrench socket hole and a second wrench socket hole, the first wrench socket hole being larger than the second wrench socket hole, the first wrench socket hole being formed at a first distance from the knife body when the knife blade is in the opened state, the second wrench socket hole being formed at a second distance from the knife body when the knife blade is in the opened state, the first distance being greater than the second distance. By positioning the larger hole further from the knife body (which serves as the handle) than the smaller hole, it is possible to ensure that the knife can be used to exert greater torque on larger nuts or bolt heads, which usually require greater torque than smaller nuts or bolts. According to another variant of the pocket knife of the invention, the plurality of wrench socket holes includes a first wrench socket hole formed in a first part of the inner region of the knife blade, and a second wrench socket hole formed in a second part of the inner region of the knife blade, the first wrench socket hole being larger than the second wrench socket hole and the first part of the inner region of the knife blade being wider than the second part of the inner region of the knife blade. By positioning the larger holes in wider parts of the knife blade, it is possible to ensure that larger wrench socket holes are surrounded by more metal than the smaller holes, so the local mechanical strength of the blade is increased for the larger socket holes for a given size and weight of blade.

According to another variant of the pocket knife of the invention, the outer edge of the knife blade includes a blunt edge portion for a user to exert pressure on the knife blade with a finger, the blunt edge portion being on the opposite side of the knife blade from the cutting edge portion, the blunt edge portion including a screwdriver tip edge portion, the screwdriver tip edge portion standing proud of the blunt edge portion. The blunt edge of a knife blade normally serves no purpose. By including a relatively large screwdriver blade at the strongest point on the blade, a useful extra tool is provided without the need for more knife elements, and the overall size and weight of the knife can be kept to a minimum.

According to another variant of the pocket knife of the invention, sprung blade locking means is provided for automatically blocking the knife blade in its opened state when the knife blade is fully displaced out from the knife body. When using the knife for turning nuts or bolts it is important that the blade does not close on the user's hand, so the locking mechanism is provided to ensure that this cannot happen.

Advantageously, the pocket knife also comprises a release button for releasing the sprung blade locking means when pressed by the user. The release button may comprise an outer pressing surface for being pressed by a user's finger, and an actuating element for urging the sprung blade locking means into an unlocked state. The outer pressing surface may be located in and substantially flush with one of the lateral faces of the knife body. In this way, the overall size of the knife can be kept to a minimum and an inadvertent unlocking of the blade can be avoided.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be now be described with reference to the accompanying drawings, which are given by way of example only, and should not be interpreted as limiting the scope of protection claimed. Where the same reference numerals are used in different drawings, the numerals are intended to refer to the same or equivalent elements.

FIG. 1 is a perspective view of a pocket knife according to the invention, with the knife blade shown in its opened state.

FIG. 2 is a perspective view of a pocket knife according to the invention, with the knife blade shown in a partial opened state.

FIG. 3 is an exploded perspective view of a pocket knife according to the invention, showing the blade in its locked state.

FIG. 4 is a plan cross-section view of a pocket knife according to the invention, with the knife blade shown in its opened state.

FIG. 5 is a partially cutaway view of a pocket knife according to the invention, showing the blade in its locked state.

DETAILED DESCRIPTION OF THE INVENTION

A pocket knife may be implemented as a multifunctional pocket tool, as depicted in figure 1 , comprising two lateral sides 16 and 19, the sides 16, 19 of the knife body 2 serving as a handle for the tool, and an interior space between said sides serving as housing to accommodate the various blades and implements when they are in a retracted or closed state. A pocket knife according to the invention is illustrated in figure 1 . The knife comprises knife body 1 , knife blade 2, and may also comprise various other blades, tools and attachments 12, 13, 14. In the example shown in figure 1 , the knife also comprises an opening 18 for receiving, preferably with a positive or click fit, a hexagonal screwdriver bit 43, 44 (or other similar hexagonal tool bit, such as an awl, socket-drive or a drill bit). The blade 2 is rotatable out from within the knife body 2, and is depicted in its opened state, locked by blocking spring 31 . The blocking spring 31 of the example, as will be described in more detail later, is a blade spring which is normally held in lateral tension, pressing against a side surface of the knife blade 2, until the knife blade 2 is in its opened state, when the spring blade 31 snaps past a shoulder of the knife blade so as to lock the latter in its opened state. By pressing on release button 17, which acts to push spring blade 31 sideways out of its locking configuration, a user of the knife can unlock the knife blade 2 so that the knife blade 2 can be returned to its closed state in the knife body 1 .

Knife blade 2 is constructed with a cutting edge 27 along part of its periphery. The cutting edge 27 is known having an edge with broad serrations, but the cutting edge 27 may equally be a plain, continuously machined sharp edge or a scalloped edge, sawtooth edge or any other configuration of cutting edge. The opposite edge of the knife blade 2 is provided with a pressing edge 26 over at least part of its extent, which is essentially a blunt or flat edge which can be used to exert a cutting pressure on the cutting edge 27, for example when the user presses with his or her finger on the pressing edge 26.

The example shown in figure 1 shows how the main or primary blade of the knife (usually the largest blade designed specifically for cutting), can also be provided with one or more wrench socket holes 22, 23, 24. By locating the wrench socket holes in the main blade itself, it is possible to remove the need for one or more extra tool blades which would otherwise be needed to provide the wrench socket function, thereby reducing the size and weight of the knife. The provision of holes in the knife blade 2 also reduces the weight of the knife blade 2 itself, with the result that the overall weight of the knife is reduced yet further. Note that the term wrench socket hole is used here to refer to a closed, regular-shaped hole machined in the (substantially flat) inner region 21 of the knife blade 2. The holes are shaped such that they can be fitted around a similarly shaped nut or bolt head, for example. The holes may be hexagonal in cross-section, or they may have a twelve-point profile, similar to the cross- section of a conventional 12-point mechanic's socket. Alternatively, they may have a Torx® profile, or a combination of holes of different sizes and/or profiles. Such wrench-like implements may also be referred to as "hex key" holes or ring-spanner holes. There may be just one hole, or there may be many. Advantageously, the size(s) and shape(s) of holes may be selected for specific uses. For example, a pocket knife designed for mountaineering or hiking may require 7mm, 10mm and 13mm hexagonal wrench socket holes for working with standard M4, M6 and M8 bolt heads. By implementing the wrench socket holes as closed holes with a continuous periphery (as opposed to open- ended spanners, in which the spanner sides can be pushed apart when significant rotational force is applied to the nut being turned), a strong socket or wrench tool is achieved. This is particularly advantageous in the case of closed wrench socket holes machined in a knife blade, since the knife blade 2 is made from very strong, hardened steel, and thus offers ideal material for

implementing the function of a ring-spanner.

The sides 16, 19 of the knife are preferably of metal, and may be covered by a moulded or injected plastic in known fashion. They can, however, also be made of any other material, for example horn, wood, etc., depending upon the aesthetic look one wishes to give the knife. Generally, the two sides 10, 1 1 comprise parallel inner faces defining an interior space 12 in which different implements are arranged in parallel, and outer faces adapted ergonomically to the hand of the user, for example symmetrical.

One or more implements can be taken out by making them slide longitudinally between the two inner faces of the sides 16 and 19, as in the known knives having a catch. The invention nevertheless applies to any type of versatile tool comprising one or more retractable implements. In particular, the invention also applies to folding knives comprising blades able to be folded up into hollow handles. Other implements, for example an attachment extension piece or tweezers (not shown) can moreover be directly accommodated in or against the sides 16, 19 of the knife body 2.

The knife or multitool may also comprise one or more removable implements, such as ¼" screwdriver bits 43, 44, which may be stored in suitable openings in the knife body or in a separate holder. In the example shown, the removable implements consist of standardized attachments able to be used also, for example, in ratchet sets or in combination with screw-driving machines.

The knife body 1 may comprise an aperture 18 provided in this example at one of the knife and allowing the divers implements 43, 44 to be received. This arrangement enables the attachments to be operated with a moment of great force and without risk of an implement folding back into the interior of the knife. The tool can be reinforced, if necessary, near the aperture 18, for example by means of a metallic plate in such a way as to withstand the moments of great force which can be applied with screwing implements 43, 44.

One of the holes in the main knife blade 2 may be machined (for example as a ¼" hex hole) such that it is suitable for receiving one of the implement bits 43, 44 and such that the implement bit 43, 44 is firmly held so that the bit 43, 44 can be turned with great rotational moment by the user gripping the knife body 1 . By arranging the hole at allocation towards the tip of the knife blade 2 (ie in a distal region of the knife blade 2), it is possible to ensure the greatest turning moment to be exerted on a bit mounted in the knife blade.

Also visible in figure 1 is a portion 25 of the knife blade, referred to as a screwdriver portion, which is designed to be used as screwdriver for slotted or cheese-head screws. The screwdriver portion 25 is a substantially straight part of the rear edge 26 of the knife blade 2 which can be used when the knife blade 2 is in its open or in its closed state. The screwdriver portion 25 preferably stands slightly proud of the adjacent sections of the rear edge 26, so that it can be used for gaining purchase on screw heads even when those screw heads are recessed or countersunk. The thickness of the screwdriver portion may be less than the thickness of the majority of the knife blade, so as to allow the screwdriver portion 25 to be used for screws with narrow slots. By locating the screwdriver portion 25 in the rear edge 26 of the knife blade 2, it is possible to ensure that the user can achieve great rotational leverage on the screwdriver portion 25 (and thereby also the screw being driven) when the knife blade 2 is in its opened state. And, when the knife blade is in its closed state, the user can gain extra purchase by being able to push down safely on the screwdriver portion 25, thereby urging the screwdriver portion 25 into the slot of the screw with great force at the same as exerting great rotational force with the hand on the whole knife body 1 .

Figure 2 shows a different perspective view of the knife of figure 1 . In figure 2, the knife blade 2 is in a partially opened state. In this state, spring blade 31 is pushed to one side by the shoulder of knife blade 2, and knife blade 2 is free to rotate towards it closed position in knife body 1 , or to its open position, where it would become locked as spring blade 31 snaps past the shoulder provided on knife blade 2. The various components of the knife are held together by river elements 1 1 in the known fashion.

Figure 3 shows a partially exploded view of the knife of figures 1 and

2. In particular, it shows the shoulder 28 of knife blade 2, which engages with the spring blade 31 when the knife blade 2 is in its fully opened state. Figure 3 also shows static knife body element 30, which serves as a strengthening element of the knife body 1 , and also provides a stop surface 34 against which a corresponding shoulder the knife blade 2 abuts when the knife blade 2 is in its fully opened state. Figure 3 also shows the release button 17, with its release actuation element 17a. When release button 17 is depressed, the release actuation element 17a presses against spring blade 31 , thereby moving the spring blade 31 sideways such that it no longer engages with should 28 of knife blade 2. Figure 3 also shows how the removable bits can be received and held in the aperture 18.

Figure 4 shows a plan view of the same knife depicted in figures 1 to

3. In particular, figure 4 shows how knife blade 2 is locked in its fully opened state by spring blade 31 and static knife body element 30, by engagement with stop shoulder 29 and lock shoulder 28 of the knife blade 2. It is in principle possible, when the primary knife blade 2 is in its fully opened state, to use the wrench holes for rotating in either direction. However, since the static body element 30 provides significantly greater anti-rotational structural support than spring blade 31 , the knife is intended to be used to apply rotation force in an anticlockwise direction as viewed in figure 4. In other words the rotational force should be applied in the same rotational direction as that in which the knife blade is rotated when it is being returned to its closed state. This reduces the risk of injury to the user. Using the knife for rotating in the other direction (in the direction of opening the knife blade 2) could result in excessive force being applied at the shoulder 29 on spring blade 31 . If spring blade 31 fails to stop the rotational force applied, then there is a possibility that the knife blade could close, under significant rotational force, on the user's hand, thereby injuring the user.

For this reason, all tools and implements 12, 13, 14 of the knife which extend outwards of the knife body 1 when in their closed state have non- sharp, rounded and/or smooth edges, so that the user can exert significant rotational force on the knife body in the desired wrench direction (anticlockwise as viewed in fig. 4) without experiencing discomfort from pressing his or her hand against any rough or pointed projections from the knife body 1 .

Figures 4 and 5 also show the positioning of release actuation element 17a in relation to the spring blade 31 . As can be seen from figure 5, the spring blade is pressed downwards (as viewed in figure 5) by release button 17 and release actuation element 17a, thereby allowing the knife blade 2 to rotate towards its closed state in the knife body 1 .