GB2392111A - Fencing sword - Google Patents

Abstract

A sword 10, composed of a foamed material, has a handle portion 11 and a blade portion 12. The sword further comprises an electrically conductive strip provided along said blade portion, which may terminate at a thumb locator 13 on the handle portion 11.

Description

23921 1 1

- 1 - FENCING SWORD

The present invention relates to fencing swords.

Fencing is acknowledged as a sport requiring particular skill, discipline and advanced eye/hand coordination. The rapid, intense nature of the sport also makes it a very good form of exercise. However, fencing has several drawbacks when compared to many other sports. Firstly, the use of metal fencing weapons, safety equipment and hit detection equipment makes it relatively expensive, especially for a beginner.

Moreover, given the dangerous nature of metal fencing weapons, in particular when they fracture, a high level of supervision must be provided which adds further to the costs. These combined factors of cost and danger hinder the sport from 20 wider introduction. Whilst many children and adults are keen

to learn fencing the formal nature of training required to maintain safety detracts from the fun of learning the sport.

There has thus existed a need within the sport to create a 25 safer and more accessible environment in which beginners can learn good technique and readily practice.

An object of the present invention is to provide a sword which can be used as a safe and effective fencing aid.

Another object of the present invention is to provide a detection system which can readily and reliably detect hits which occur in fencing contests/duels between at least two

people. According to an aspect of the present invention, there is provided a sword comprising a blade portion and a handle 5 portion, both composed of a foamed material, wherein the sword further comprises an electrically conductive strip provided along said blade portion.

In preferred embodiments said electrically conductive strip 10 is provided along the length of the blade portion, a first end of said strip terminating at the thumb locator on said handle portion. Conveniently, a finger/thumb sensor worn by a user contacts 15 said first end of said electrically conductive strip in use of the sword, said finger/thumb sensor being electrically connected to a hit detection means.

A first signal may be carried from said hit detection means 20 to said electrically conductive strip when the finger sensor is in contact with the first end of the electrically conductive strip. Hence, in use when the sword user's finger sensor contacts the first end of the electrically conductive strip, the electrically conductive strip becomes 'live'. Said 25 first signal may be a low frequency RF signal.

Preferably, said electrically conductive strip acts as an antenna. Said hit detection means may act as a receiver which can receive said low frequency RF signals.

Preferably, said hit detection means comprises a series of conducting wires mounted on a piece of material and a hit monitoring means mounted thereon.

- 3 - The present invention will now be described by way of example with reference to the accompanying figures, wherein: Figure 1 shows a side view of a known foam sword; Figure 2 shows the known foam sword of Figure 1 provided with a hand guard; Figure 3 shows a side view of an embodiment of the sword of 10 the present invention; Figure 4 shows a handle portion of the sword of Figure 3 of the present invention; 15 Figure 5 shows a plan view of a guard portion used in conjunction with the present invention; Figure 6 shows a side view of a further embodiment of the sword of the present invention; Figure 7 shows a view of apparatus for use with the present invention; and Figure 8 shows a schematic representation of the apparatus of 25 Figure 7.

Figures 1 and 2 show known swords composed of foam material or polymeric materials. Such swords have been produced and i sold for use solely as toys or gimmicks at for example, 30 fencing competitions. These swords are constructed in such a manner that when they are used their inherent flexibility causes them to bend significantly in a designated comical manner, for example when used to parry a blow from another

4 - sword The known foam sword of Figure 1 comprises a blade portion 4 and a handle portion 3. The sword narrows down to its 5 narrowest region in the region of the handle portion. This construction of a blade portion, which is wider relative to the thinnest point of the handle portion causes in use there to be a pivot point 1 at the transition area where the blade portion becomes the handle portion. Thus when such a sword is 10 used to parry a blow, the sword will readily bend at this pivot point.

Figure 2 illustrates the sword of Figure 1 where a guard portion 5 is fitted on to a sword. The arrangement of the 15 guard portion is such as to emphasise region 1 as a pivot point. These factors make the existing foam swords completely ineffective as realistic fencing aids.

Figures 3 and 4 show a sword 10 of the present invention 20 comprising a handle portion 11 and a blade portion 12. The handle portion 11 (shown in closer detail in Figure 4) is provided with a thumb locator 13 and a grip portion 14 which has a contoured/textured surface, for example corrugated or rippled. The thumb locator 13 encourages a correct fencing 25 grip and improves the realism of the sword. Similarly, the grip portion 14 acts to give the user a comfortable and firm grip. Each end of the handle portion 11 is provided with a pair of guard locating grooves 15, 16. A first pair 15 of these guard locating grooves are positioned towards a front 30 end of the handle portion 11 and are defined by a pair of asymmetrically opposed high shoulders 17. A second pair of guard locating grooves 16 are positioned towards a rear end of handle portion 11.

- 5 - The blade portion 12 extends from a portion of the handle portion 11 adjacent said first pair of guard locating grooves 15 and comprises a 'cutting' edge 20 which terminates in a point 21.

In the present embodiment of the present invention the sword is in total approximately 700 mm long and 22 mm thick. The shape of the sword is diecut from a 22mm thick sheet of foamed polymeric material such as polyethylene. The density 10 of the polymeric material is preferably from 50 to 100 kg/m3.

In certain embodiments the sword may comprise a relatively stiff inner core encapsulated by a softer outer covering.

15 As shown in Figure 3, the handle portion is arranged to be at least as wide as the widest part of the blade portion. In other words, the dimension X is at least as great as the dimension Y. In this embodiment the handle portion has a width of at least 35mm.

The use of foamed material for the sword strikes a compromise between rigidity, hardness and weight in order to maximise rigid handling characteristics and minimising the pain of a hard strike. The foamed material needs to be rigid enough to 25 hold its form when struck and soft enough so as not to be dangerous in a fencing situation.

A guard portion 30 shown in Figure 5 is attachable to the sword by way of the guard locating grooves 15,16. The guard 30 portion comprises a generally flat pear-shaped member provided with two locating holes 31,32 which are used to releasably attach the guard portion 30 to the sword 10. The guard portion 30 is arranged such that locating hole 31 on the widest

- 6 - section of the guard portion 30 can be fitted around the grooves 15 defined by the asymmetrically opposed shoulders 17.

In a similar fashion, the locating hole 32 positioned at the narrower end 34 of the guard portion 11 can fit around the 5 grooves 16 at the extreme end of the handle portion of the sword. The guard portion 30 is die-cut from 8mm thick foamed polymeric material and is relatively flexible. This 10 flexibility allows the guard portion 30 to be bent into an arcuate shape when fully attached to the sword. When so bent, the inherent resilience of the guard portion puts the handle portion under tension thereby affording it enhanced rigidity.

15 An asset of the guard portion is that it makes the sword and guard arrangement aesthetically pleasing to the eye, adds to the realism of the sword in protecting the user's hand and gives a solid feel. The major advantages of using the guard are that realistic parries can be made with the guard; the 20 guard also strengthening the sword giving added rigidity to the handle portion.

In a further embodiment of the invention an electrically conductive strip 40 may be attached to the sword as 25 illustrated in Figure 6. One end 41 of the electrically conductive strip is connected to the blade portion 12 near the point 21. The strip is connected along almost the entire length of the blade portion on the 'cutting' edge 20 and terminates at a second end 42 at the thumb locator 13.

In practice, the fencer/duellist wears a lame coat/jacket/body suit (not shown) provided with conducting fibres. In order to register hits a lightweight electronic device (known as a

- 7 - Battlebox device(Trademark) and shown in Figures 7 and 8 can be connected to the coat/jacket/body suit. Further, an electrical connection must be provided between the thumb locator on a sword carried by a fencer/duellist and the 5 Battlebox device 50. A lame sock (not shown) may in this regard be fitted over the players thumb and an unobtrusive wire connected to the player's Battlebox device.

In a duelling situation, hits are detected by means of low 10 frequency RF signals. The Battlebox device provides an offensive signal to the conductive strip 40 on the cutting edge of the sword and listens for the receipt of such a signal on the electrically conductive suit that covers the target area i.e. the suit of an opponent.

Once the Battlebox device of an opponent detects that the player has been hit it can for example make an audible sound, flashes some lights, transmit a radio signal to that effect and disables the player for a short time i.e. it does not 20 transmit an offensive signal or detect any further hits from opponents. This allows the player to remove themselves from immediate danger of a repeated strike.

In one embodiment the sword acts as a transmitting antenna by 25 means of the electrically conductive strip 40 and the suit of an opponent acts as the receiving antenna. The system is designed such that radio-frequency signal current is induced at a point of contact on a body jacket. If more than one sword is used in a battle, each sword is designed to have a distinct 30 low frequency RF signal. These signals are produced by the corresponding Battlebox devices and allow fighters to be identified during a battle.

- 8 - With fencing scoring products currently available, electricallyconducting wires connect the competitors to hit-

detection circuitry. However, with the Battlebox device arrangement RF technology can be used in order that the 5 contact between weapon and body suit of two opponents may be detected by radio-frequency signal current induced at the point of contact, and which may also serve as a medium to convey information identifying the competitors concerned.

Such information may be by way of modulation of the radio 10 frequency signal, whether by amplitude, phase or frequency modulation, or combination thereof.

Wireless technology is not new and there are consequentially a number of available off-the-shelf RF modules to suit the 15 requirements of a wide range of products.

Unlike existing security-based devices (e.g. transmitting vehicle keyfates etc) which use radio frequencies to convey authority codes, the mode of operation is usually to require 20 that the receiver/decoder receives a valid code from the transmitter/encoder before initiating the intended function.

The non-receipt or corruption of a valid transmitted code merely results in the requirement to re-transmit the required code to initiate the function. However, with regard to the use 25 of codes to identify individuals in a battling match, corruption of such codes by external interfering means would not be permissible as this would open up the possibility of cheating - such as an accomplice in the audience using a signal "jammed" to mask the identity of a competitor achieving 30 a successful hit, for example.

The system would therefore have to employ suitable techniques and radio frequencies to render interference from other

9 - sources such as signal jammers practically impossible, though it would in practice never be possible to guarantee that Battlebox devices would be entirely immune from interference.

In minimising the strength of any interfering signal to a 5 Battlebox device receiver, it is considered desirable to keep the operating frequencies as low as possible. As the wavelength of a low-frequency signal gets proportionally longer the lower the frequency, the length of a resonant radiating antenna must be correspondingly longer to achieve 10 the same efficiency as a shorter antenna operating at VHF or UHF (the same rule also applies to a receiving antenna, i.e. the body suit. This would considerably increase the required length of the radiating antenna relative to a system operating at a higher frequency for example, which would contribute to 15 making any portable signal jammer generally inefficient and unwieldy. It would also be a simple matter to detect any attempt at defeating the security of the system by remotely monitoring the field strength of any signals of the same

frequency as used by the Battlebox device.

Due to the portable RF-based approach, the Battlebox system will rely on batteries carried around by the player. The opportunity to use large batteries is therefore restricted to the size of the case within which the batteries will be 25 housed, and as the case must be as small as possible it follows that only relatively small batteries should be used.

It is therefore important that efficient use is made of circuit supply current.

30 Circuit losses generally increase at higher frequencies, largely due to stray capacitance and wiring inductance that becomes much more significant in the VHF/UHF regions and above. Furthermore, signal- amplifying components themselves

- 10 generally become less efficient at the higher frequencies, increasing the number of stages of amplification to achieve the desired signal gain and thereby increasing the overall operating current requirement.

The use of lower frequencies permits the use of commonly available lowfrequency components offering substantially greater gain at low operating current, though with inter-

device characteristics which restrict their suitability to 10 frequencies less than a few Megahertz. Therefore, only at lower frequencies may the circuit complexity be reduced by the use of such components, with a corresponding reduction in battery drain.

15 The Battlebox device product is envisaged for use on the world stage and, as such, it is preferable to use radio frequencies for hit detection that will be acceptable for use in a number of different countries. As a result of substantially reduced free radiation at lower frequencies, the propensity for the 20 Battlebox device to interfere with other electronic devices or communications systems is very substantially reduced and it is therefore anticipated that operation at such frequencies will find easier acceptance for approval purposes.

25 In providing a Battlebox system that operates on relatively low radio frequencies, the possibility of interference to i broadcast band reception must be considered. However, use of the very low band frequencies (i.e. Long-Wave) by radio stations has substantially declined over the years due to the 30 increased use of MW and FM VHF frequencies, providing wider bandwidth for high-quality music content (eta) as well as minimising interference from everyday sources radiating at lower frequencies.

It is true that Long-Wave is still used today, but it is considered that the opportunities for a Battlebox device to interfere with a long-wave radio reception might be as great as a domestic television or computer, and only if the S broadcast listener is in very close proximity to a Battlebox device in use.

As the Battlebox system will only act upon direct contact between transmitter and receiver of two separate units worn I 10 by opposing players, the longer wavelength of a low frequency assists in reducing free radiation and therefore minimising any opportunity for stray signals to interfere between players, or cause false triggering where contact has not actually occurred. It is therefore easier to reliably 15 distinguish between a signal received through free radiation or stray capacitance, and a signal received through direct contact as the difference between the two would be significantly greater at lower frequencies.

20 For reasons briefly outlined above, the use of higher frequencies would restrict the ability to use a variety of I board materials and compositions, and would tighten the window! on component types and tolerances. These factors alone could impact on a manufacturer's ability to minimise on component 25 costs and broaden its supplier base, and introducing volatility in delivering agreed quantities over extended periods should a particular component vendor fail to deliver for any reason. The use of lower frequencies would permit a much wider range of component alternatives to be specified, 30 thereby sustaining production through alterative sources with minimal impact on deliverables.

In a more complex version, an external scoring system may be

- 12 provided. This would involve the Battlebox devices of each player reporting back the hit status of each player. Although this would preferably include the incorporation of high-

frequency modules which are type-approved for the country in 5 which they are being operated, these transmitters will not be required to be running continuously and therefore supply efficiency of the high-frequency transmitter would not be so much of a concern. However, the simultaneous use of signals for external scoring and Battlebox device hit-detection, I 10 without interference to either, is essential and easily achieved when the two signal frequencies are very well separated. There are common inexpensive PLL-based devices capable of 15 directly detecting frequency modulation on frequencies up to 500kHz and for which the maximum speed of change detectable is f/20. This means that the state of the modulating logic signal must be sustained for at least as long as the PLL is able to detect the shift (i.e. 20 RE cycles), before returning 20 to its alternative state. Adopting a signal frequency of 500kHz the maximum theoretical speed of data would be f/20 or I 25,000kb/s, though in practice it would be preferable to consider half of this figure so as to allow for a comfort margin from the maximum attainable figure for reliability.

25 This therefore results in a data speed of 12,500kb/s, or 375bits of data within 30ms. This should adequately allow for not only the identity code itself but for additional re-

transmissions for error-checking and detection assurance, though would not realistically allow for bi-directional 30 communication. Attempting bi-directional (i.e. full duplex) communication from the outset would appear to be unwise as (a) this would impact upon the ability to arrive at a workable design solution within a reasonable time frame and (b) any

- 13 development to bi-directional communicability may be done in retrospect to a functional simplex design. It should also be noted that in transferring codes to identify individual competitors, reliable contact must be maintained over the 5 minimum duration to permit uninterrupted transfer of data, and it must be assumed that this will be possible.

Whilst it would therefore appear that Frequency Modulation would be attractive in supporting realistic data rates, this I 10 would require that the transmitter maintained a constant transmission in order to convey intelligence (i.e. data) on the signal. However, this would complicate matters as far as preventing false triggering of the receiver for the following reasons. It is necessary to consider the effect of two weapons clashing, each transmitting a continuous signal and their associated receivers each awaiting a sudden increase in signal at the receiver input. At the time of contact, the received i 20 signal from the opponents weapon would be conducted through the output structure of the driving circuit and will pass I through the receiver front end to radiate via the body suit.! The receiver would therefore realise a sudden increase in signal amplitude and would falsely trigger as a result of 25 weapons clashing. This problem must therefore be addressed by discriminating against anything other than weapon-to-body contact. Whilst it is possible to detect the direction of a radio 30 frequency signal (i. e. received or transmitted through an effective aerial), circuitry that will perform this function reliably and rapidly remains a subject of further investigation. However, an alternative to the continuous

- 14 transmission approach (i.e. FM) would be to gate the transmitter path on whilst gating the receiver off, and vice versa, so that the receiver could not falsely respond to weapons clashing. Using such a method would not suit frequency 5 modulation (particularly where swords are concerned), where the carrier must be uninterrupted in order to convey data, though this would suit amplitude modulation where the data itself could be used to gate on the transmitter for each logic pulse of the respective code, and gate on the receiver to 10 detect a logic pulse from the opposing transmitter.

Furthermore, as the transmitted code between two opposing players would be different, it could be guaranteed that there would be at least one instance in every code burst where the receiver of one player is active and the transmitter of the 15 opponent is transmitting one bit of information.

With regard to amplitude modulation the maximum speed of data transfer will be significantly lower than FM, and an estimated lkb/s resulting in 30bits/ms. However, if the data were to be 20 compared three times over to prevent errors in data detection, this would allow each code burst to comprise ten bits, including the header sequence. Allowing say four bit intervals as the code header and the six remaining to convey simple binary, this would permit a code permutation of 64 to 25 be checked twice within 30ms or three times within 40ms, as reception of the first burst is likely to be corrupted and would appear as preamble.

In consideration of the above, the early test approach was to 30 design a prototype which would facilitate development of a Battlebox device design solution offering only half-duplex communication but permitting early investigation into amplitude modulation capability, based on the limitations of

- 15 project-board construction and to determine a worst-case solution. The configuration and operating concept is as follows: 5 each competitor has one Battlebox unit situated approximately between the shoulders and in a pocket on a vest, on which only the inside of the pocket and a target area on the vest front comprises conductive Lame cloth. The conductive inner of the pocket would connect the receiver contact of the box to the 10 target area on the front of the vest, and a separate transmitter socket contact on the box would be wired to the weapon. The weapon would continuously transmit a modulated carrier, 15 conveying the identity code of the weapon holder, and the receiver would identify a bit from valid data contained in the received signal from an opponent.

During a battle weapons would inevitably come close to body 20 suits but not actually make contact. The receiver would realise some signal from the opponents weapon in such an event, but one characteristic of this signal would be that the change in signal strength (i.e. from each subsequent logic bit) would be relatively slow. Additionally, the receiver 25 would also realise a significant level of signal from the transmitter of the same unit, largely through crosstalk about the body of the Battlebox device wearer, although the receiver would be gated off whilst the transmitter is active in the case of amplitude-modulated data. The receiver would employ 30 automatic gain control to maintain a degree of minimal signal amplification to within practical levels.

The successful contact of the opponent's weapon to the target

- 16 area may therefore be detected by a very sudden and substantial rise in received signal strength at the receiver input, in comparison to any previous signal whilst active. At such time it would be necessary to immediately suppress the 5 transmitter of the hit recipient in order that the opponents transmission can be fully monitored without interruption, and to prevent the hit recipient from intentionally blocking the attackers signal through maintained weapon-to-weapon contact, for example. It is also conceivable that the weapon of a 10 competitor may touch his own vest just prior to that of the opponent's, but this will have only occasional or no impact as the control gating between transmitter and receiver would be synchronized and the decoder would therefore fail to respond, with the exception of noise components.

These units may comprise a signal generator (transmitter) of approximately 450kHz using standard values, a high-gain receiver which will ultimately be gain-adjusted automatically (though fixed for purposes of experimentation), and some logic 20 providing signal squaring, differentiation, and gated monostable functions. Furthermore, a lowfrequency oscillator was added for testing the ability of the differentiator and gated monostable to reliably indicate a fast signal edge whilst also providing the basis for discriminating out 25 crosstalk from its own transmitted code. The modulation technique was 100% amplitude modulation.

As it is clear from above detection of a frequency-modulated signal may prove practicable, the purpose of such units is (a) 30 merely to determine the reliability of detecting a hit, and discriminating out slow- rising edges, (b) to test the design of a high-gain low-frequency receiver amplifier using low-

frequency transistors, and (c) through experimentation to pre

- 17 establish approximate signal levels at the intended operating frequency that will be encountered in practice (e.g. crosstalk variation and body effects).

5 Without automatic gain control for the units, it is nevertheless clear that there is a high degree of tolerance to non-contact input signal level variation but only when the differentiator is included in the circuit. For example, without AGC or differentiator, the input signal varies wildly 10 and the response indicator LED indicates a received signal with even mere crosstalk. However, once the differentiator is included to follow the RF detector, only a sudden contact between transmitter and receiver aerials causes the LED to reliably respond for a timed duration controlled by the IS triggered follow-on monostable. However, the differentiator requires to see a sudden variation in signal amplitude of about three volts, and is only effective in the absence of dynamic range limitation. Therefore, the inclusion of an AGC circuit is essential in controlling the nominal gain of the 20 RF front-end in response to crosstalk variation, and the dynamic range of the differentiator should adequately accommodate AGC response time whilst serving to reliably detect rapid signal level transitions in the event of a hit.

25 The dimensions of the Battlebox device 50 carried by the player on a battling suit are approximately 33 x 95 x 158 mm and each unit a compartment 52 for four "AA" batteries. The Battlebox device and the circuit components therein have been designed with robustness in mind considering the nature of the 30 fighting environment. One solution to this has been to use a printed circuit board (PCB) with surface mounted components, especially one with an encapsulating resin over the components. Further, components with successive serial

- 18 numbers burned into them are to be used. The reasoning behind this being that every unit can be produced with a signal different to that ofevery other unit, thus making each unit distinguishable from all the others.

The devices employed to generate and validate codes are proprietary offthe-shelf IC's which generate words comprising 9 bits each and validating after two error-free words received in immediate succession.

These units will each have a beeper to indicate that the opponent has scored a hit and that the code has been validated. The beeper will operate for approximately one second once triggered. However, a return hit will be possible 15 lOOms after a hit detection (i.e. as a result of sudden signal rise on the body suit, whether validated or not). In practice however, the control software can clear the lOOms interval if the maximum expected duration between successive received bits is exceeded.

In practice the body suit will be isolated during the transmit cycle and conversely the weapon for the receive cycle, there arises the distinct possibility that signal conduction through weapon-to-weapon contact would allow sufficient opponents 25 signal to be conducted through the hand and on to the body suit, and so falsely triggering the unit to act on the signal.

This problem has been addressed by actively comparing the difference in low-level signal strength between the weapon and the body suit, permitting the unit to respond to a received 30 signal only when that from the body suit is the greater.

If a weapon of a first player makes contact with that of an opponents, the corresponding unit of this player will detect

- 19 this and fail to respond to any signal on the body suit as the received opponents signal is greater from the weapon.

However, this condition must not be sustained throughout weapon-to-weapon contact as a condition must be allowed for 5 where the opponent makes a valid strike against the body suit of the first player, even though the two weapons are still in contact. Accordingly, the body suit signal will rapidly rise, but could still be less than or, at best, equal to that on my weapon, but in this event a response to this hit must still 10 be allowed to take place. Therefore, the comparator detecting the signal differences between weapon and body suit has a continuation timeout of around 100ms, though instantly reset whenever the two weapons part contact.

15 Dead-shorts must not be permitted to exist between the live weapon and the body suit, otherwise the signal difference between weapon and body suit could be so slight that the unit fails to respond due to simultaneously seeing a sudden signal rise on both the weapon and body suit at roughly equal levels.

20 This will mean that the difference comparator might cut in certain circumstances (e.g. general noise might be the only difference factor), giving rise to possible unreliability. A closed loop detector circuit is included which detects a DC current path of >5ma between the weapon and body suit, causing 25 the associated unit to go into continuous receive/detect mode 20ms and removing any advantage that this might otherwise provide to the user. The onus therefore rests with the user to ensure that this condition does not occur. One embodiment of this unit could provide a different alert mode to indicate 30 the presence of such a condition that must be corrected if not to present a continued disadvantage to the user.

Referring to Figure 8, a body jacket and weapon are

- 20 illustrated on the left hand side, and a microcontroller on the right.

The microcontroller generates a continuous stream of coded 5 data, which is amplified and transmitted on to the weapon from the weapon transmitter, suitably connected. DC bias is also provided at the weapon to trigger the DC loop detector if the weapon and jacket of the same player make contact.

10 The jacket RX switch and weapon RX switch are controlled and phased accordingly by the microcontroller, and the amplified signals from each are compared by the amplitude comparator.

A sudden rise in amplitude at the differentiator input 15 triggers the microcontroller to decode data from the data slicer on proviso that the amplitude comparator does not indicate that the weapon is receiving a coded signal of significantly greater amplitude than the body jacket. This condition would be true if two weapons were to clash and the 20 jacket RX amplifier were to realise sufficient signal due to body crosscoupling, for example.

The DC loop detector causes the microcontroller to immediately go into decode mode, so as to allow an opponents weapon to 25 make contact with the players weapon as well as touching the player's jacket. This also prevents any possibility of cheating by simply shorting the weapon and jacket connections together. 30 Operating mode selection is facilitated by a manual switch (53 on Figure 7).

Drive for both internal and optional headset loudspeakers is

- 21 provided by a current amplifier, amplifying audio tones appropriately generated by the microcontroller.

Internal and external LED displays are controlled by display 5 I/O and interface circuits, which also control the generic interfacing to a headset of suitable functionality and design.

In general the game will have three modes: auto reset, one hit and three hit. When a fighter is hit a buzzer will sound and 10 a red light 51 on the Battlebox device 50 will illuminate.

Yellow amnesty lights 54 will flash alternately. When fighting in a three hit battle the fighter has the chance to escape an attacker during an amnesty period during which they can neither hit or be hit. If the fighters are fighting one-on-one 15 in controlled circumstances then this is their opportunity to stop and for a referee to award a hit if it is valid before continuing. Whilst battling the fighters would either have their box set 20 to one hit or three hit mode. In one hit mode the fighter becomes neuter after being hit once, only by removing the box and selecting reset mode can the fighter be re-activated. In three hit mode the fighter needs to be hit three times before becoming neuter; the first and second hits will trigger a five 25 second amnesty where the fighter can run to another position.

Helmets or face masks may be required during fighting in order to make it safe for fighters to attack from behind especially if using metal weapons. As a consequence these helmets or 30 masks will be different from existing fencing masks which are open at the back. A possible solution to this problem would involve a hinged gate riveted to existing masks with a protective bib attached like there is at the front. The masks

- 22 may themselves form part of the valid target area. If not then a wider range of materials and production methods are available and lightweight helmets with perspex visors can be considered. During a battle a fighter may wish to see a replica of the lights displayed on their Battlebox device. An audience or a referee may also want to see the status of each fighter, The Battlebox device is therefore provided with a socket 55 where 10 extension lights can be plugged in. A set of LEDs can be mounted both on and in the fighters helmet. A small panel of LEDs are positioned at the top of the fighters visor and larger indicators on the top of the helmet. The design of the extension lights is determined by the kind of helmet used.

In order that the exact status of each fighter can be displayed on a large scoreboard a more advanced battle box would have the ability to transmit it's status to a remote scoring apparatus. The audience would then be able to follow 20 the progress of the battle both on the court and on the scoreboard. During a duel hits are often disputed and a referee needs to be able to demonstrate that the equipment is not being 25 interfered with. The battle box will need to store the serial number of the box that hit them or that they hit. The referee's verifier would be capable of quizzing the boxes to determine who hit who. Should the two boxes concur then the equipment would have been verified and the hit can then be 30 awarded.

At the end of a battle it would be useful if all the boxes used could download the details of who hit them to a computer

- 23 so that individual statistics can be determined and studied.

This equipment might simply be hit by the fighter to download the data or cradles that hold the boxes, making contact with the jacket connector could be used.

There are several fighting environments in which the swords may and Battlebox devices may be used. Firstly there is the simple duel scenario. Two fighters occupy a circular area 10 metres in diameter. A referee moves around the circle 10 controlling the fight and the first player to score fifteen hits is declared the winner. The duel consists of three periods of 3 minutes with a minutes rest between each period.

In this fight scenario the Battlebox devices are set to auto reset mode. This is a twist on the current competition fencing 15 bout.

A second option is known as fast battling. This consists of two teams, each of three players, distinguished by different coloured battling colours. A referee oversees the contest and 20 uses a whistle to dictate play. A marked court of no fixed size is used e.g. a badminton court. Battlebox devices are set to one hit mode. This is a quick and fun way to oppose many teams of three fighters. As each fighter is hit they must leave the court immediately, failure to do so will forfeit the 25 entire battle for their team. The last team standing wins.

A further option comprises teams of five fighters distinguished by different coloured battling colours. This option is known as competition battling and is once again 30 officiated by a referee with a whistle. The fighting takes place on a marked court of no fixed size but bigger than that used for fast battles e.g. a basketball court. Battlebox devices are set to three hit mode for this option. This is a L

- 24 formula for a serious battle with three hit mode fighters allowed to fight elsewhere after being injured by a particular fighter. With five fighters on each team realistic battle tactics will emerge. As each fighter becomes neuter they must 5 leave the court immediately, failure to do so will forfeit the entire battle for their team. The last team standing wins.

Another fighting option is known as multipoint battling. This 10 fight comprises several equally sized teams of fighters distinguished by different coloured battling colours. This option is once again officiated by a referee with a whistle.

The fighting takes place on a marked court of no fixed size but bigger than that used for fast battles e.g. a basketball 15 court. The Battlebox devices are set to three hit mode in this option. This is a fun battle involving many teams; alliances may be formed but they must be broken if one team are eventually to win. As each fighter becomes neuter they must leave the court immediately, failure to do so will forfeit the 20 entire battle for their team. The last team standing wins.

One further fighting is known as freeforall battling. This involves individual fighters. Once again a referee with a whistle oversees the contest. The fighting takes place on a 25 marked court of no fixed size but bigger than that used for fast battles e.g. a basketball court. The Battlebox devices are set to three hit mode in this option. This is a fun battle involving everybody, alliances may be formed but they must be broken if an individual wants to win. As each fighter becomes 30 neuter they must leave the court immediately. The last fighter standing wins.

Claims (9)

À 25 CLAIMS:

1. A sword comprising a blade portion and a handle portion, both composed of a foamed material, wherein the sword 5 further comprises an electrically conductive strip provided along said blade portion.

2. A sword according to claim 1, wherein said electrically conductive strip traverses the length of the 10 blade portion, a first end of said strip terminating at a thumb locator on said handle portion.

3. A sword system according to claim 2, wherein a finger/thumb sensor worn by a user contacts said first end of 15 said electrically conductive strip, said finger/thumb sensor being electrically connected to a hit detection means.

4. A detection system according to claim 3, wherein a first signal is carried from said hit detection means to said 20 electrically conductive strip.

5. A sword according to claim 4, wherein said first signal is a low frequency RF signal.

256. A sword according to any one of claims 1 to 5, wherein said electrically conductive strip acts as an antenna.

7. A sword according to claim 5 or 6, wherein said hit detection means can act as a receiver which can receive said 30 low frequency RF signals.

8. A sword according to any one of claims 3 to 7, wherein said hit detection means comprises a series of conducting

- 26 wires mounted on a piece of material and a hit monitoring means mounted thereon.

9. A sword according to any preceding claim, wherein 5 said sword comprises an inner core material encapsulated by an outer material, the inner core having a greater density than the outer material.