Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16P—SAFETY DEVICES IN GENERAL; SAFETY DEVICES FOR PRESSES
  • F16P3/00—Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body
  • F16P3/12—Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body with means, e.g. feelers, which in case of the presence of a body part of a person in or near the danger zone influence the control or operation of the machine

Definitions

• the present invention relates to safety arrangements for power machinery and in particular to safety arrangements for operator protection during the use of such machines.
• EP 0362937 and EP0636830 Prior art arrangements dealing with this problem are disclosed in EP 0362937 and EP0636830. Both of these documents describe an operator wearing two gloves, a conductive glove with an overlaying insulating glove.
• EP 0636830 describes an arrangement in which operator safety for a meat processing (cutting) machine is considered. In this prior art arrangement, an operator wears conductive gloves and rests his feet on conductive plates, which are insulated from the ground. The machine itself is electrically connected to earth. An electrical current is passed through the operator's body. If the operator makes contact with an electrically conductive part of the machine, the current is short-circuited to earth and the machine is stopped or reversed.
• the gloves are worn because the hands are in the most dangerous area of the operation and the conductivity of the gloves helps to ensure an easier path to earth for the current in the event of contact. In this manner, the proposal hopes to reduce the propagation delay between the initial contact and interference with the machine cycle.
• the current is passed through the operator by his wearing electrically conductive footwear and standing with one foot on each of a pair of conductive plates.
• a low-tension voltage (12-24V) is put across the plates and current is generated through the operator body, entering through one conductive shoe and exiting through the other.
• One disadvantage of the manner in which current is passed in this prior art system is in the use of conductive plates, which require a more or less fixed operating stance with both feet in specific positions. This restricts operator freedom of movement and also places limits on where the operator may stand. For example, a long machine may require periodic movement of operator position along a working bed.
• EP0636830 The solution offered in EP0636830 is to wear another pair of gloves, this time insulating, above the conductive gloves and rely on the outer insulating gloves to be torn away or their insulation compromised in some other way in the event of operator/machine contact so as to allow the short circuit through the then exposed conductive glove below.
• One problem with the prior art solution is that an operator must remember to put on the outer insulating gloves and in any case the overall bulk of the resultant combination may restrict feel or movement. This solution may also prove less than satisfactory in some other ways and applications. If machines used in the metal industry as discussed above are considered, some of their moving parts may not be of such a nature as to tear away the outer insulating glove.
• the present invention provides a safety arrangement for a power operated machine.
• the safety arrangement includes a safety glove being worn in use by an operator of said machine and comprising a conductive layer, a charging device adapted to put a user wearing said glove at a different voltage potential with respect to one or more conductive parts of said machine and a control device adapted to monitor said potential and to substantially halt or reverse movement of a part of said machine in the event of a change in said potential indicative of contact between said user and at least one of the conductive parts.
• the glove further comprises an insulating layer integral with the conductive layer and extending over a working area of the glove.
• the level of insulation over the conductive layer is reduced compared to that in the working area to form a protection area, e.g. the non-working area has less thickness of insulation material compared to the working area, or protrusions of the conductive layer are formed towards the insulation layer in the non-working area to penetrate the insulating layer over the non-working area in case of a crushing accident.
• the conductive layer may be left exposed over a non-working area of the glove so as to form a protection area. This ensures that the operator is able to handle with said working area of the glove a work piece or material associated with said machine without making electrical contact with one of the said electrically conductive parts of said machine, and benefits from protection against contact with said machine over at least said protection area.
• the safety glove may be made, according to a first embodiment, of a complete conductive glove, covered at the working area with an insulating material leaving the conductive layer exposed in the protection area.
• it may be made of a complete insulating glove, covered at the non-working area with a conductive material.
• it may be formed of two different parts, a conductive part and an insulating part.
• it may be made of a complete insulating glove which covers completely a conductive material. In all embodiments, the conductive part and the insulating part are made integral with each other.
• the insulating layer integral with the conductive layer may cover at least part of a palm and/or digit area.
• the insulating layer does not extend substantially onto a top surface of at least a backhand area of said glove to form a protection area.
• the protection area may cover at least part of an upper surface of the backhand and/or digit area of said glove.
• Said integral insulating layer may comprise any suitable material and is preferably flexible and hard wearing. In some applications it is preferably liquid impermeable.
• the insulating material may be at least one of a polyvinyl chloride material (PVC), an insulating elastomer such as a rubber material and a synthetic coating or resin.
• Said integral insulating layer may further comprise protection against mechanical injury to a gloved hand, for example by mechanical resistance to cuts from swarf or burrs on a work piece or machine part. Such protection may include, for instance, fibre reinforcements are additional protection plates attached to the surface.
• the conductive layer may comprise e.g. a textile such as any knitted, braided or woven or non-woven conductive material, for instance conductive textile material or steel wire.
• the conductive layer is flexible.
• the conductive layer does not need to be knitted.
• the conductive layer may be a conductive coating, e.g. made of a conductive polymer such as conductive polyurethane.
• Said charging device may comprise a foot operated machine control such as a switch or pedal which is adapted to apply a low tension voltage to an operator through a conductive piece of footwear, the operator being insulated from earth potential at his opposite foot.
• the low-tension voltage is preferably between 5 and 30 volts, most preferred about 12 volts.
• the conductive piece of footwear preferably comprises a sole formed of a special elastomer material of high electrical conductivity.
• the operator may be insulated from earth potential by wearing insulating footwear on said opposite foot and/or by placing said opposite foot onto an insulating surface.
• the insulating piece of footwear preferably comprises a sole formed of an insulating elastomer material or a synthetic resin. A breakdown in insulation between said opposite foot and earth potential may be treated by said control device in the same manner as electrical contact between said operator and said machine.
• Said foot operated control may include a sensing device for monitoring at least one of the resistance through said conductive piece of footwear, a current through a portion of said conductive footwear and a potential difference between said operator and said machine or earth potential.
• Said control device may check authorisation of the operator to use said machine, may monitor for faulty footwear and may enable machine cycling only if both said checks pass.
• Said authorisation check comprises for example a resistance check through said conductive footwear.
• Said control device may be operatively connected between said foot operated control and a cycle controller of said machine. It is optionally integrated with said foot operated control.
• Said foot operated control may be moveable, for example by provision of a flying lead connection.
• Said machine may be operated by co-operation between said foot operated control and a hand operated control, for example by enabling operation of said machine by means of said foot operated control and initialising an operating cycle by means of a hand control operated by the same operator using said foot control or by an associated operator.
• Said charging device may be provided with a power supply galvanically separated and operationally independent of a machine cycle supply.
• Said operator may be brought to said potential difference substantially only in an operating cycle of said machine during which cycle parts of said machine are moving, those moving parts preferably comprising user accessible parts.
• Said potential difference between said operator and said machine may be positive, for example +12 volts.
• Said control device may determine a contact between said operator and said machine by a drop in the potential difference therebetween.
• Said machine may comprise a machine in which parts move, preferably slowly, i.e. for example in the order of 15 cm/s or slower, preferably 10 cm/s or slower, towards each other in the region of a materials handling portion accessible to an operator, for example folding machines or cutting devices such as power shears.
• the present invention also provides a method of operating power machinery and manipulating work pieces or material in association therewith, including: a) wearing as an operator a safety glove comprising a conductive layer and an integral insulating layer, said insulating layer covering a working area of said glove such as for example a palm and or digit area and at least part of a further area of said glove has a reduced insulation level compared to the working area to form a protection area, e.g.
• the method may include charging said operator through an electrically conductive piece of footwear, said charging being supplied through a foot operated machine control, preferably in the form of a low tension voltage, and insulating the opposite foot of said operator.
• the method may include insulating said operator by wearing non- conductive footwear on said opposite foot and/or placing said opposite foot on an insulating surface.
• the method may include monitoring at least one of the resistance through a part of said conductive footwear, preferably a sole thereof, and a current through a portion of said conductive footwear.
• the method may include charging said operator from a power supply substantially operationally independent of a machine cycle supply, said independent power supply being fed through said foot operated control.
• the method may include charging said operator only in an operating cycle of said machine during which cycle parts of said machine are moving, those parts preferably comprising user accessible parts.
• the present invention also provides a safety glove suitable for use in a safety arrangement or method according to the invention.
• a safety glove suitable for use in a safety arrangement or method according to the invention.
• Such a glove comprises a conductive layer and an integral insulating layer over a working area of said conductive layer, a non-working area of said conductive layer having a reduced insulation level compared with the insulation level over the working area. For example, the conductive layer in the protection area may be left exposed.
• the safety glove may be made, according to a first embodiment, of a complete conductive glove, covered at the working area with an insulating material.
• a second embodiment it may be made of a complete non-conductive glove, covered at the non-working area with a conductive material.
• it may be formed of two different parts, a conductive part and an insulating part, which are integral with each other.
• a complete insulating glove which covers completely a conductive material. In all embodiments, the conductive part and the insulating part are made integral with each other.
• Said integral insulating layer integral with the conductive layer may cover at least part of a palm and/or digit area.
• the insulating does not need to extend substantially onto at least a backhand area of said glove.
• Said protection area may cover at least part of an upper surface of the backhand and/or digit area of said glove.
• Said integral insulating layer may comprise a suitable insulating material which is preferably flexible and hard wearing. In some applications the insulating layer should be impermeable to liquids.
• the insulating material may be at least one of a polyvinyl chloride material (PVC), an insulating elastomer such as a rubber material and a synthetic coating or resin.
• Said integral insulating layer may further comprise protection against mechanical injury to a gloved hand, for example by mechanical resistance to cuts in use from swarf or burrs on a work piece or a machine part. Such a resistance may be provided by embedded fibre reinforcements or plates attached to its surface.
• the conductive layer may comprise a flexible conductive layer especially a conductive textile, e.g. any knitted, braided, woven or non-woven conductive material, such as conductive textile material or steel wire. The conductive layer does not, however, need to be knitted.
• the present invention further provides safety footwear for use in an arrangement or method according to the invention or in conjunction with a glove according to the invention.
• the footwear comprises a pair of footwear in which each piece of the pair has a different electrical conductivity, preferably one piece being electrically conductive and the other piece being electrically insulating.
• Figure 1 is a schematic diagram of a safety arrangement for power machinery according to an embodiment of the present invention.
• Figure 2 is a drawing of a palm view and a backhand view of a safety glove used in the arrangement of Figure 1.
• Fig. 3A is a cross-sectional view of an embodiment of an upper body of a power machine comprising an upper part and an intermediate part attached to each other by means of an intermediate part.
• Fig. 3B is a detailed elevational view of the intermediate part as represented in Fig. 3A, the intermediate part being provided with movement means for moving separate units of the intermediate part towards or away from each other.
• a safety arrangement is provided for a power machine which, in the illustrated embodiment, comprises e.g. a metal folding machine 10 for materials and work pieces such as sheet metal or plate 40.
• the folding machine 10 comprises lower and upper bodies 12, 14 which move slowly towards each other, e.g. at a speed between 10 cm/s and 13 cm/s, to clamp a work piece 40 between them.
• a machine cycle controller 16 controls a motor (not shown separately) which moves a machine part in the form of a pivoting jaw 18 so as to fold the work piece 40 upwardly in the direction of the arrow 18a and back downward to the rest position after a fold of the desired nature has been applied to the work piece 40.
• the folding machine 10 has been set-up for illustrative purposes only such that the maximum fold is a right angle, generated by pivoting the jaw 18 until the work piece 40 comes up against a limit surface 14a of the upper body 14. It will be appreciated by those familiar with this sort of machine that intermediate folds and other folding configurations can be employed.
• the work piece 40, lower and upper bodies 12, 14 and the pivoting jaw 18 are all metal, as is the limit surface 14a, and therefore all are electrically conductive.
• the metal parts of the machine are earthed through the cycle controller 16 and by earth cables to earth potential E. Particular attention is paid to machine parts which move and especially those in user accessible positions.
• a safety glove 28 which, according to one embodiment, comprises a conductive layer 28a, e.g. a conductive glove of the supplier ANSSELL n.v., located in Aalst, Belgium, for example type HYFLEX 11-620.
• the conductive layer of each glove 28 then defines a cavity 28b into which in use the appropriate operator hand 30 is inserted.
• Each glove 28 further comprises an integral insulating layer 28c, made from an insulating material such as polyvinyl chloride (PVC) or a suitable insulating elastomer such as rubber or a synthetic resin or coating.
• PVC polyvinyl chloride
• a suitable insulating elastomer such as rubber or a synthetic resin or coating.
• a silicone 3481 obtainable from Dow Corning is used.
• the insulating layer 28c is integrated with the conductive layer 28a by any suitable method, such as e.g. bonding, over-moulding, immersing, spraying, etc.
• a conductive glove may be pulled over a pre-formed hand, after which this pre-formed hand with glove is put in a mould, which reveals only one side of the glove. The revealed side of the glove is then covered with an insulating polymer, for example by spraying.
• the insulating polymer cannot be applied onto the non-revealed side of the glove, and the insulating and conductive parts on the glove have a neat dividing line.
• An alternative possibility is to apply, for example by gluing, a piece of polymer which is previously cut to measure. This method also provides a nice dividing line between the insulating and the conductive part of the glove.
• the insulating layer 28c is applied over a working area of the glove 28, i.e. the area of each glove 28 normally used to handle and contact work pieces
• the insulating layer 28c preferably covers at least the majority of the palm area 30a and preferably also the underside part of each digit 30b.
• the insulating layer 28c preferably also provides protection to an operator from mechanical injury from the likes of swarf or burrs either on the work piece 40 or on the folding machine 10 itself. The protection may be provided by mechanical resistance of the insulating layer 28c to cuts or tears.
• the insulating layer 28c does not extend at all, or at least not very far, onto the backhand 30c of the glove 28, the backhand 30c preferably being considered also to include the upper surface of the digits 30b.
• the conductive layer 28a is left exposed over substantially all the surface area of the glove 28 not normally used to handle or make contact with work pieces 40 and referred to for convenience as a non-working area of the gloved hand 28, 30.
• the exposed conductive layer 28a over the non-working area of the glove 28 forms a protection area, as will be discussed in further detail below.
• a charging device is provided to put the operator at a different voltage potential with respect to the conductive parts 12, 14, 14a, 18 of the folding machine 10.
• the charging device is incorporated as part of a safety monitoring and control circuit 20a associated with a foot operated machine control in the form of foot switch/pedal 20, and supplies the potential to the operator from a power supply 22 which is operatively separated from the power supply 16a to the folding machine 10 being controlled.
• the operator is raised to a positive potential of between 5 and 30 volts, preferably about 12 volts above that of the normal grounded state of the folding machine 10. It will be appreciated that other potential differences could be employed in dependence on application specific circumstances.
• charging In order to keep to a minimum the amount of time an operator is kept under charge, charging preferably only occurs during a machine cycle in which parts 12, 14, 18 of the folding machine 10 which are user accessible are moving.
• the pedal 20 is preferably moveable, for example by connection to the cycle controller 16 using a flying lead. This improves flexibility of the arrangement over those arrangements, which call for foot controls in fixed positions by, for example, allowing an operator to move the work area along or around the folding machine 10. It is also possible for operators to work in teams with, for example, a second operator initialising an operating cycle using a hand control 32, which will only take place if the charged operator passes the safety checks described below.
• the monitoring and control circuit 20a further co-operates with a sensing device in the form of a pair of sensors 20b which are integrated with the pedal 20 and spaced apart towards opposite ends of the operator's conductive footwear 24.
• the sensors 20b and the monitoring and control circuit 20a perform safety checks of the authorisation/ competence of the operator to use the machine, check for faulty footwear 24 and monitor the potential of the operator.
• the monitoring and control circuit 20a may be incorporated in the pedal 20 or may be a separate unit operatively connected between the foot pedal 28 and the cycle controller 16.
• an electrically conductive shoe is used with an electrical resistance between 200 k ⁇ and 1 M ⁇ .
• Such a shoe can e.g. be found on the market under the tradename EMMA from supplier EMMA, located in the Netherlands.
• an insulating piece of foot wear 26 is worn on the foot opposite to the one used to operate the pedal 20.
• a breakdown in insulation of the insulating footwear 26 will have the same effects, and be treated in the same manner as, contact between the operator and the folding machine 10.
• a pair of conductive foot wear 24, 24 could be worn, but in that case it would prove necessary to make sure that the operators opposite foot 26a was placed on an insulating surface during folding cycles or otherwise isolated from earth potential E. This would, however, give the operator the choice of which foot 24a, 26a to use to enable folding cycles.
• a person skilled in the art can easily provide a monitoring and control circuit 20a based on standard electronics. It may be based on a FET transistor as a measurement instrument. The circuit 20a can also be built with an operational amplifier or a transistor. Even a high frequency signal can be used, either on the machine or on the operator, with which switching takes place at the moment of changing this signal.
• the operator To perform a folding cycle, the operator first manipulates or places a work piece 40 in a clamped position between the lower and upper bodies 12, 14 of the metal folding machine 10. Next, an operating cycle is enabled by the operator pressing the pedal 20 using the foot 24a wearing the conductive footwear 24.
• the monitoring and control circuit 20a measures between the sensors in the pedal 20 whether the resistance in the conductive footwear 24 is low enough. If so, a timer is set which is in an ON position during e.g. 3 seconds, and during that time period it is checked by the monitoring and control circuit 20a whether a contact (conductive path) exists between the operator (the conductive part of the glove) and the sensors in the pedal 20. If not, a cycle enable signal is sent to the cycle controller 16, otherwise no cycle enable signal is sent. The operator then presses a hand control in the form of a cycle start button 32 and, if the cycle controller 16 has received a cycle enable signal from the monitoring and control circuit 20a, the cycle will be performed and the jaw
• the operator retains the sensitivity of an apparently single skinned pair of gloves 28 and doesn't suffer from, for example, loss of control, feel or dexterity as might happen during relative movement between gloves in a two glove per hand arrangement.
• the upper body 14 may be formed by an upper body 14 comprising an upper part 14a and a lower part or tool 14b fixed to each other by means of an intermediate part 14c, as shown in Fig. 3A.
• This intermediate part 14c consists of two massive parts 15a, 15b which fit to each other, for example by means of a V-shape, as shown in Fig. 3B. Both parts 15a, 15b are connected to each other by means of movement devices, such as for example small hydraulic cylinders 50.
• hydraulic cylinders 50 are actuated together with the actuation of the machine (actuation means for the hydraulic cylinders 50 or connections thereto are not represented in Fig. 3B). This means that if the upper body 14 moves towards the lower body 12 (upper body 14 moves down), then part 15b moves away from part 15a (part 15b moves down more than part 15a) by means of hydraulic cylinders 50. If the upper body 14 moves away from the lower body 12 (upper body 14 moves up), then part 15b moves towards part 15a by means of the hydraulic cylinders 50. If a dangerous contact is made, i.e.
• the machine is halted and/or reversed, which means that the upper body 14 does not move any longer towards the lower body 12.
• the hydraulic cylinders 50 are actuated so as to make part 15b move towards part 15a.
• Parts 14b and 15b are much smaller than upper body 14 in its entirety, and therefore suffer less from inertia. Therefore parts 14b and 15b can move up faster, and thus the total concourse will be smaller than the concourse when the upper body 14 consisted of one single piece.
• the insulating layer 28c is applied not only over a working area of the glove 28, i.e. the area of each glove 28 normally used to handle and contact work pieces 40 but also over other non-working areas of the glove, e.g. the backhand. To achieve this, the insulating layer 28c extends beyond the majority of the palm area 30a and preferably also the underside part of each digit 30b.
• the insulating layer 28c preferably also provides protection to an operator from mechanical injury from the likes of swarf or burrs either on the work piece 40 or on the folding machine 10 itself. The protection may be provided by mechanical resistance of the insulating layer 28c to cuts or tears.
• the insulating layer 28c can extend onto the backhand 30c of the glove 28, the backhand 30c preferably being considered also to include the upper surface of the digits 30b.
• the conductive layer 28a is not left exposed over substantially all the surface area of the glove 28 not normally used to handle or make contact with work pieces 40 and referred to for convenience as a non-working area of the gloved hand 28, 30. Without further modification this glove does not react quickly to a crushing accident.
• the insulation level in the non-working area is reduced compared to the working area. This reduction in insulation level can be achieved for instance by reducing the insulation thickness to a level below that used in the working area.
• Another method is to provide protrusions on the outer surface of the conductive layer such as spikes directed towards the insulating material so that on crushing pressure these penetrate through the insulating layer and activate the machine stopping procedure.
• protrusions on the outer surface of the conductive layer such as spikes directed towards the insulating material so that on crushing pressure these penetrate through the insulating layer and activate the machine stopping procedure.
• a trade-off is made between protection of the operator and preventing accidental machine stoppages by accidental contact with the exposed conductive layer.
• a safety arrangement for a power operated machine 10 includes a safety glove 28 being worn in use by an operator of said machine and comprising a conductive layer 28a, a charging device adapted to put a user wearing said glove at a different voltage potential with respect to one or more conductive parts 12, 14, 18 of said machine and a control device 20a adapted to monitor said potential indicative of contact between said user and a said conductive part.
• Said glove 28 further comprises an integral insulating layer 28c over a working area of said glove. An insulation level over the conductive layer 28a is reduced over a non-working area of said glove so as to form a protection area. For example, the conductive layer is exposed in this region.
• said integral insulating layer 28c can cover at least part of a palm and/or digit area 30a and does not need to extend substantially onto at least a backhand area 30c of said glove 28, Said protection area can cover at least part of an upper surface of the backhand and/or digit area 30c of said glove 28.
• said integral insulating layer 28c can comprise any suitable insulating material. The material is preferably flexible and supple. In some applications it can be impermeable to liquids.
• said integral insulating layer 28c can further comprise protection against mechanical injury to a gloved hand, for example by mechanical resistance to cuts from swarf or burrs on a work piece or machine part.
• said conductive layer 28a can comprise any flexible conductive material, e.g. one of conductive textile material or steel wire.
• said charging device can comprise a foot operated machine control
• said charging device 20 which is adapted to apply a low tension voltage to an operator through a conductive piece of footwear 24, the operator being insulated from earth potential (E) at his opposite foot. Said operator can be insulated from earth potential (E) by wearing insulating footwear 26 on said opposite foot and/or by placing said opposite foot onto an insulating surface. A breakdown in insulation between said opposite foot 26a and earth potential (E) can be treated by said control device 20a in the same manner as electrical contact between said operator and said machine 10.
• said charging device 20 can include a sensing device 20b for monitoring at least one of the resistance through said conductive piece of footwear 24, a current through a portion of said conductive footwear and a potential difference between said operator and said machine 10 or earth potential (E).
• said control device 20a can check authorisation of the operator to use said machine 10, monitors for faulty footwear 24, 26 and enables machine cycling only if both said checks pass.
• said control device 20a can be operatively connected between said foot operated control 20 and a cycle controller 16 of said machine 10 and is optionally integrated with said foot operated control.
• said foot operated control 20 is moveable.
• said machine 10 can be operated by co- operation between said foot operated control 20 and a hand operated control 32.
• said charging device can be provided with a power supply 22 operationally independent of a machine cycle supply.
• said operator can be brought to said potential difference substantially only in an operating cycle of said machine 10 during which cycle parts 12, 14, 18 of said machine are moving, those moving parts preferably comprising user accessible parts.
• said potential difference between said operator and said machine 10 can be positive.
• said control device 20a determines a contact between said operator and said machine 10 by a drop in said potential difference therebetween.
• said machine 10 comprises a machine in which parts 12, 14, 18 move towards each other in the region of a materials handling portion accessible to a said operator.
• a method of operating power machinery 10 and manipulating work pieces or material 40 in association therewith including a) wearing as an operator a safety glove 28 comprising a conductive layer 28a and an integral insulating layer 28c, said insulating layer covering a working area of said glove and the glove having at least part of a further area 30c of said glove over which the level of insulation is reduced, e.g. is substantially free of insulating material; b) charging said operator to a voltage potential different from one or more conductive parts of said machine, preferably by means of a voltage positive with respect to said machine parts; c) monitoring said operator potential with respect to said machine parts and preferably also with respect to earth potential (E).
• the second aspect can include charging said operator through an electrically conductive piece of footwear 24, said charging being supplied through a foot operated machine control 20, preferably in the form of a low tension voltage, and insulating 26 the opposite foot 26a of said operator.
• the above method can include insulating said operator by wearing non-conductive footwear 26 on said opposite foot 26a and/or placing said opposite foot on an insulating surface.
• the above method can include monitoring at least one of the resistance through a part of said conductive footwear 24, preferably a sole thereof, and a current through a portion of said conductive footwear.
• the second aspect can include charging said operator from a power supply 22 substantially operationally independent of a machine cycle supply, said independent power supply being fed through said foot operated control 20.
• the second aspect can include charging said operator only in an operating cycle of said machine 10 during which cycle parts 12, 14, 18 of said machine are moving, those parts preferably comprising user accessible parts.
• a safety glove 28 suitable for use in a safety arrangement according to aspect 1 is provided or in a method according to aspect 2, said glove comprising a conductive layer 28a and an integral insulating layer 28a over a working area of said conductive layer, a non-working area of said conductive layer having a reduced insulation level to form a protection area, e.g. the conductive layer is left exposed.
• Said integral insulating layer 28c can cover at least part of a palm and/or digit area 30a and does not need to extend substantially onto et least a backhand area 30c of said glove.
• said protection area can cover at least part of an upper surface of the backhand and/or digit area 30c of said glove.
• said integral insulating layer 28c can comprise any suitable insulating material.
• the material is preferably flexible and hard wearing. In some applications it should be liquid impermeable.
• the insulating material may be at least one of a polyvinyl chloride material (PVC) and insulating elastomer such as a rubber material.
• PVC polyvinyl chloride material
• said integral insulating layer 28c further comprises protection against mechanical injury to a gloved hand.
• said conductive layer 28a can comprise any flexible conductive material, e.g. a conductive textile material such as knitted, woven, braided or non-woven textiles comprising metal fibres, or steel wire.
• safety footwear 24, 26 is provided for use in an arrangement according to aspect 1 , in a method according to aspect 2 or in conjunction with a glove 28 according to aspect 3, said footwear 24, 26 comprising a pair of footwear in which each piece of the pair has a different electrical conductivity, preferably one piece being electrically conductive 24 and the other piece being electrically insulating 26.

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• Footwear And Its Accessory, Manufacturing Method And Apparatuses (AREA)
• Gloves (AREA)
• Professional, Industrial, Or Sporting Protective Garments (AREA)

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• 2002
  • 2002-09-23 US US10/490,990 patent/US20040244091A1/en not_active Abandoned
  • 2002-09-23 EP EP02776617A patent/EP1430251A1/de not_active Withdrawn
  • 2002-09-23 WO PCT/BE2002/000147 patent/WO2003027565A1/en not_active Application Discontinuation

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