GB2600139A

GB2600139A - A line-cutter

Info

Publication number: GB2600139A
Application number: GB2016801.9A
Authority: GB
Inventors: Ritchie John; Moriarty Katherine; Craig Mark; Mclean Euan; Bentley Andrew
Original assignee: Chemring Energetics UK Ltd
Current assignee: Chemring Energetics UK Ltd
Priority date: 2020-10-22
Filing date: 2020-10-22
Publication date: 2022-04-27
Anticipated expiration: 2040-10-22
Also published as: WO2022084660A1; GB2600139B; GB202016801D0

Abstract

A line-cutter for cutting a wire or a cable. A blade 5 is attached to an arm 3 which is pivotally attached 4 to a body 2. The arm 3 is pivotable relative to the body. The body includes an attachment portion 7 for attaching a pyro-mechanical actuator device 6 having a piston arranged to move the blade relative to the body, via movement of the arm, to cut a wire once actuated. The pivot location 4 may be situated between a first end 11 and a second end 12 and may be closer to the second end than the first. The body may comprise a first side 27 and a second side 28 between which the arm may be moveable in a space. The first and second side may be V-shaped to assist in locating a target line into a cutting position. The blade 5 may be formed of a non-conductive material to ensure the ends of the cut wire do not conduct, beneficial for use in bomb deactivation.

Description

A LINE-CUTTER

FIELD OF THE INVENTION

[0001] The present invention relates to a line-cutler for cutting a line. BACKGROUND OF THE INVENTION [0002] The disposal or disabling of hazardous explosive devices may require cutting one or more wires, cables, cords, strings or other types of line using a line-cutter. It is important for the line to be cut reliably, cleanly, and for re-connection of the cut ends of the line to be prevented.

SUMMARY OF THE INVENTION

[0003] A first aspect of the invention provides a line-cutter for cutting a line. comprising: a blade attached to an arm and moveable relative to a body of the line-cutter, wherein the body includes an attachment portion for attaching a pyro-mechanical actuator device with a fully contained pyrotechnic or propellant charge to drive a piston arranged to move the blade relative to the hotly, via movement of the arm, so as to cut a line when the pyro-mechanical actuator device fires, wherein the blade is attached to a first end of the arm, the piston is arranged to contact a second end of the arm, and the arm is pivotally coupled to the body.

[0004] A pyro-mechanical actuator device is an actuator having a pyrotechnic or propellant charge inside that is fully contained with the pyro-mechanical actuator device before, during, and after actuation. Pyro-mechanical actuators (also called Pyrotechnic actuators) of the present invention are exempt from Class 1 of the UN Recommendations on the Transport of Dangerous Goods Model Regulations. Pyromechanical actuators are operable to provide motion to a piston that extends from the body of the actuator upon actuation. The pyro-mechanical actuator uses the rapid expansion of hot gas, evolved from the combustion of a pyrotechnic or propellant charge, to drive the piston with very high thrust (e.g. 2400N or more over a 9 5 mm stroke length). All pyrotechnic or propellant effects are contained within the body of the pyro-mechanical actuator device, such that there is no fragment, no projectile and no significant surface temperature spike external to thc device resulting from initiation of the charge.

l00051 The line may be any slender wire, cable, string, cord, detonator cord, or similar, and may include more than one such wire, cable, string, cord, detonator cord, or similar, e.g. as a bundle. The line may have a circular or non-circular cross section.

[0006] The line-cutter may be used to cut a floating, or suspended, line without interfering, manipulating and/or tensioning the line as the line is about to be cut. The line-cutter may be positioned about the line such that the line-cutter does not make any contact with the line until the blade is actuated to cut the line. The line-cutter may be used in explosive ordnance disposal (OED).

[0007] A pyro-mechanical actuator provides a high thrust to the piston of the actuator that is transferable to the blade such that it is able to cut a line when the line-cutter is positioned around a floating line such that the blade moves across the path of the line. This thrust is greater than that achievable with a similarly sized mechanical actuation system, such that the line-cutter with a pyro-mechanical actuator can be made smaller, lighter and more reliable, with minimal or zero maintenance or servicing. As the pyromechanical actuator is sealed, the pyrotechnic or propellant charge is fully contained inside the actuator. This means the line-cutter is safer to use, and may be used, purchased, stored, and transported by civilian personnel in non-military applications. The line-cutter may also be reusable, for example by replacing the pyro-mechanical actuator after each use, and thereby reducing waste.

[0008] As the arm is pivotally coupled to the body, the arm acts as a lever arm so that the motion of the pyro-rnechanical actuator piston can be transferred to an angular motion of the blade.

[0009] Optionally, the pivot location is closer to the second end of the arm than the first end of the arm.

[0010] With this arrangement, the lever arm (moment arm) of the blade is increased such that a given linear actuation of the pyro-mechanical actuator device results in a greater movement of the blade about. the pivot axis. The distance between the first end of the arm and the pivot location may be more than 2 times larger than the distance between the second end of the arm and the pivot location, preferably more than 3 times larger, and more preferably 4 times larger.

[00111 Optionally, wherein, upon actuation, the line-cutter is arranged to substantially fix a line between opposing surfaces of the arm and the body when a line is cut.

[0012] This helps to prevent re-connection of the two ends of a line when die line is cut. Typically, when a line is cut into two line portions, the line-cutler is arranged to fix one of the two line portions, such that the other line portion is freed from the line-cutter arran2ement, although the line-cutter may be arranged to fix both of the two line portions.

[0013] Optionally, wherein, upon actuation, the line-cutter is arranged to press a line between opposing surfaces of the arm and the body so as to bend the line.

[0014] This helps to prevent re-connection of the two end of a line when the line is cut. When a line is cut into two line portions, the line-cutter is arranged to bend one of the two line portions near an end. By bending one end of a line portion, the line portion is directed at an angle to the other line portion. This can help to reduce the possibility of line re-connection, for example by pointing the lines in different directions and spacing the ends of the lines apart. The line is bent towards an end of the line portion, for example the bend may be in the end 5mm of the line, or lamm of the line, or 20mm of the line. The angle of the bend is preferably substantially 90 degrees, although may be more or less. For example, the angle may be less than 60, or more than 30 degrees.

[0015] Optionally, the body includes a first side and a second side, and the arm is moveable in a space between the first and second sides.

[0016] Optionally, wherein the first and second sides are arranged to accommodate a line extending across the space. With this arrangement, the blade can he a free-swinging blade which cuts the line without the need for a blade backboard. This can reduce blade blunting and produce a cleaner cut, as well as assist in separating the ends of the cut line efficiently.

[0017] Optionally, wherein the first and second sides are shaped to assist in locating the line-cutter about a target line into a cutting position, preferably wherein the first and second sides include a generally V-shaped portion. With this arrangement, the line-cutter can be guided into a cutting position to ensure the line-cutter is in a good position in relation to the line prior to cutting and as the line is cut, such that the reliability of the line-cutter is improved.

[0018] Optionally, wherein a first side of the arm is substantially flush with the first side of the body and a second side of the arm is spaced from the second side of the body. This is one way in which the line-cutter can be arranged to move the cut end portion of the line between the body and the arm so as to fix or clamp the cut end portion of the line and/or bend the cut end portion of the line between the body and the arm. The space between the second side of the arm and the second side of the body may be approximately the same thickness or diameter as a line to be cut. Alternatively, the space between the second side of the arm and the second side of the body may be tapered such that line-cutter may accommodate a range of different thicknesses or diameters of line to be cut. Alternatively, the space between the second side of the arm and the second side of the body is initially larger than the thickness or diameter of the line, and the space reduces as the arm rotates during actuation of the blade so as to clamp the line. The arm may translate relative to the body in the direction along of the pivot axis as the arm rotates about the pivot so as to cause the space between the second side of the arm and the second side of the body to reduce.

[0019] Optionally, wherein the blade is attached to the first side of arm. With this arrangement, the blade is substantially flush with the first side of the body as the blade is moved during actuation. The side of the body is thereby able to react the downward force of the blade, so as to provide a clean cut of the line.

[0020] Optionally, wherein the blade is a linear blade.

[0021] Optionally, wherein the body includes a base configured to house the Made upon actuation. With this arrangement, the user is at least partially protected from the blade when the line-cutler is actuated. The base may also house part of the line, further restricting the possibility of line re-connection post-cut.

[0022] Optionally, wherein, upon actuation, the arm is configured to be substantially fixed in an actuated position. Preferably, the blade is housed in the base in this configuration. With this arrangement, the safety of the line-cutter is increased. For instance, a blade on the end of the arm is fixed. The arm may be fixed automatically upon actuation, or may be manually fixed, for example by a clip or other mechanism.

[0023] Optionally, the line-cutter comprises a pyro-mechanical actuator device.

[0024] Optionally, wherein, upon actuation, the pyro-mechanical actuator device is configured to fix the arm in the actuated position. The pyro-mechanical actuator device may be a non-return type.

[0025] Optionally, wherein the arm is arranged to be released from the actuated position by removal of the pyro-mechanical actuator device. With this arrangement, the line-cutter can be disarmed after actuation and maintained in the disarmed configuration until the line-cutter is ready to he re-armed with a new pyro-tnechanical actuator device.

[0026] Optionally, wherein the pyro-mechanical actuator device is releasably attached to the attachment portion.

[0027] Optionally, wherein the piston is arranged to frictionally engage the second end of the arm. By frictionally engaging the arm, as opposed to being fixedly coupled to the arm, the piston is easily disengaged from the arm without having to uncouple a fastening or other device. This allows the pyro-mechanical actuator device to be removed more [0028] Optionally, the pyro-mechanical actuator device is a linear actuator. The piston extends linearly from the body of the pyro-mechanical actuator.

[0029] Optionally, the piston has a stroke length of between 3mm and 20mm. Preferably, wherein the stroke length is between 8mm and 12mm.

[0030] Optionally, the piston travels the stroke length in less than 25ms, preferably less than 20ms, and more preferably less than 12ms.

[0031] Optionally, wherein the blade is formed of a non-conductive material, preferably ceramic material. This arrangement may be advantageous in certain scenarios, for example when interference with magnetic fields is a cause for concern. Alternatively, the blade may comprise a conductive material.

[0032] Optionally, the line-cutter comprises a connector for connecting to a lanyard, support wire, tripod, or robot. With this arrangement, the line-cutter can be easily connected to external devices that can allow the line-cutler to be held in a specific position and orientation, as well as moved accurately to a specific location or orientation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Embodiments of the invention will now be described with reference to the accompanying drawings, in which: [0034] Figure 1 shows an exploded view of a line-cutter; [0035] Figure 2 shows an perspective view of an assembled line-cutter; [0036] Figure 3 shows a line-cutter connected to a control box; [0037] Figure 4 shows a side view of the line-cutter; [0038] Figure 5 shows an alternative perspective view of the line-cutter; [0039] Figure 6 shows a top view of the line-cutter; [0040] Figure 7 shows a bottom view of the line-cutter; [0041] Figure 8 shows a line-cutter including a hook arranged to hold a line; [0042] Figure 9 shows three line-cutters contained in a case; [0043] Figure 10 shows a line-cutter attached to a robot; [0044] Figure 11 shows the line-cutter attached to a tripod.

DETAILED DESCRIPTION OF EMBODIMENT(S)

[0045] Figure 1 shows an exploded view of a line-cutter 1. The line-cutter 1 includes a body 2 and a lever arm 3pivotally coupled to the body 2, e.g. by a pin 4 about a pivot axis 4a (i.e. pivot location). The pin 4 is inserted through holes 20 formed in sides 27, 28 of the body 2 of the line-cutter I. [0046] A cutting blade 5is attached to a first end 11 of the lever arm 3, e.g. by screws 9. The blade 5 may be a scalpel blade, a Stanley blade, a custom blade or any COTS blade. The blade 5 is preferably sharp, inexpensive, readily available and hard. The blade 5 may be a linear blade, such that it lies upon a single geometric plane. The blade 5 may be attached to one side of the first end 11 of the lever arm 3, such that the blade 5 is positioned between the lever arm 3 and a wall of the body 2. The blade 5 may be replaceable, for example when the blade 5 has blunted or when a new type of blade 5 is required. Alternatively, the blade 5 may be pernmnently fixed to the lever arm 3.

[0047] The blade may be formed of a non-conductive material, for example a ceramic. This may be an advantage when interference with magnetic fields is a cause for concern. The blade 5 may comprise material so as to be a non-sparking blade when cutting the line. A non-conductive blade material may be advantageous for electrostatic discharge hazard avoidance. Alternatively, the blade 5 may be formed of a conductive material, e.g. metal.

[0048] The body 2 and lever arm 3 are typically formed of plastic, such as a thermoset plastic, however it will be clear that the body 2, lever arm 3, and other components of the line-cutter 1 may be formed of any suitable material, such as metal or glass fibre composites. All parts of line-cutter may be non-conductive for electrostatic discharge hazard avoidance.

[0049] A pyro-mechanical actuator device 6 is attached to the body 2, e.g. via a fixture 7. The fixture 7 may have a threaded end 7a that screws into a corresponding threaded hole (not shown) in the body 2 of the line-cutter 1. The fixture 7 may be used to fix the pyro-mechanical actuator device in place on the body 2 during use. The fixture 7 may additionally allow removal and replacement of the pyro-mechanical actuator device 6 after use. In an alternative example, the fixture 7 may be attached to the body 2 by additional screws 17, as shown in Figure 9.

[0050] The pyro-mechanical actuator device 6 may be a Metron Actuator, obtainable from Chemring Energetics UK Ltd. The pyro-mechanical actuator device 6 may be grounded. Grounding the pyro-mechanical actuator device 6 helps avoid initiating the pyro-mechanical actuator device 6 prematurely. The pyro-mechanical actuator device 6 may be arranged for remote activation. The pyro-mechanical actuator device 6 may be configured for ease of use, e.g. for one handed operation. The pyro-mechanical actuator device 6 may have a fixture, e.g. a threaded portion, for attaching the pyro-mechanical actuator device 6 to an external device.

100511 A piston (shown in a retracted state in Figure 1) of the pyro-mechanical actuator device 6 is arranged to extend linearly from the actuator 6 upon actuation of the actuator 6. Upon actuation the piston is arranged to push against a second end 12 of the lever arm 3, such that the lever arm 3 rotates about the pivot axis 4a and moves the blade 5. The piston is arranged to press against the second end 12 of the lever arm 3. An impact plate 22 may be attached to the arm, e.g. by screws 21, to protect the arm at the location where the piston presses against the arm. The piston may be frictionally engaged with the second end 12 of lever arm 3, e.g. via the impact plate 22, but not fixedly coupled to the lever arm 3. When the pyro-mechanical actuator device 6 is assembled to the body, e.g. via the fixture 7, in some examples, the piston does not engage the arm 3 until the actuator 6 is fired (initiated), in further examples, the piston engages the arm 3 prior to, during, and after firing the actuator 6.

[0052] The line-cutter 1 is be arranged to accommodate a line to be cut, extending across between the sides 27,28 of the body 2, so that the line can be cut by the blade 5.

[0053] In some examples, the arm 3 is arranged such that the pivot axis 4a is closer to the second end 12 of the arm 3 than the first end 11 of the arm 2. In this way, any movement of the second end 12 of the arm 3, for example due to movement of the piston of the pyro-mechanical actuator device 6, is amplified by a reciprocating movement of the first end 11 of the arm 3. The ratio between the distance from the pivot axis 4a to the first end 11 of the lever arm 3 and the distance from the pivot axis 4a to the second end 12 of the lever arm 3 is typically greater than 2:1, preferably greater than 3:1, and more preferably about 4:1.

[0054] The lever arm design allows thicker and/or tougher lines to be cut than would otherwise be possible if the blade 5 were actuated linearly.

[0055] The line-cutter 1 is arranged to cut a line reliably and safely, as will be apparent from the discussion below.

[0056] Once actuated, the piston of the pyro-mechanical actuator device 6 may be permanently extended, such that the lever arm 3 is held in an actuated position by the extended piston of the actuator 6. In this position, the blade 5 is also fixed in position and thereby reduces the possibility of a user being cut by the blade 5, e.g. when subsequently handing the line-cutter 1. In addition, holding the lever arm 3 in this actuated position can also be used to securely hold one end of the cut line after it is cut, as will be explained below.

[0057] The pyro-mechanical actuator device 6 is operated by an electrical impulse. The energetic materials within the pyro-mechanical actuator device 6 are ignited, causing the internal pressure to rapidly increase and force the piston to extend from the body of the actuator 6 towards a target (i.e. the lever arm 3). The pyro-mechanical actuator device 6 contains a small amount of pyrotechnic explosive or propellant charge, for example around 100mg, but is able to contain all explosive gases, without any release of fragment or projectile, or any significant surface temperature spike, external to the device 6, and is excluded from the UN Recommendations on the Transport of Dangerous Goods Model Regulations Class 1.

[0058] The pyro-mechanical actuator device 6 is able to operate within milliseconds of receiving an appropriate electrical impulse, for example 20 milliseconds, which is not typically achievable with a mechanical source of energy. In this time, the piston is operable to travel its full stroke length.

[0059] The piston of the pyro-mechanical actuator device 6 typically has a stroke length of between 3mm and 20mm, and preferably approximately lOmm.

[0060] The speed, piston stroke length, and level of electrical impulse to initiate the charge can all be tailored to a particular application.

[0061] The pyro-mechanical actuator device 6 is a single use device. The line-cutter 1 may be a single use device, or the line-cutter 1 may be used multiple times by removing the pyro-mechanical actuator device 6 after use so that another pyro-mechanical actuator device 6 can be attached to the line-cutter 1 for a subsequent operation. The pyro-mechanical actuator device 6 may be operable using a battery or from a mains electricity supply. A DC current of approximately 1 Amp for 10ms may be required to initiate the pyro-mechanical actuator device 6.

[0062] A connector 15 may be attached to an external face of the line-cutter 1 for connecting the line-cutter to, e.g., a tripod, robot, lanyard, suspended wire, or other device as described below in relation to Figures 10 and 11. In one particular example, the connector 15 may be an insert placed into a recess 16 formed in the body 2. Alternatively, the connector 15 may be one or more hooks or any other suitable connection for coupling the line-cutter 1 to a suspended wire, for example.

[0063] The line-cutter 1 may include a stand 18 for supporting the line-cutter 1 in a given position. The stand 18, as shown in Figure 1, may be a kick-stand. The stand may have two ends pivotally inserted into holes 19 formed in the body 2, such that the stand is rotatably coupled to the body 2 and provides an adjustable stand to assist in positioning the line-cutter 1 on any given terrain. For example, the stand 18 can be adjusted to adjust the position of the line-cutter 1 relative to a line to be cut.

[0064] To reduce the ability of the lever aim 3 to freely rotate about the pivot axis 4a, the line-cutter I may also include a friction device arranged to frictionally engage between the body and the lever arm 3. The friction device may comprise a tensioning screw 25 extends through a hole 26 formed in the body 2 and frictionally engages a portion of the lever arm 3. Alternatively the friction device may comprise a nipple or other projection on the lever arm 3 or the body 2 to frictionally engage with the other of the lever arm 3 and the body 2, so as to resist relative rotation of the lever arm 3 and the body 2 about the pivot axis 4a.

[0065] Figure 2 shows a perspective views of the line-cutter 1 when assembled, in which it can be seen that rotation of the stand 18 is partially restricted by part of the body 2.

[0066] As shown in Figure 3, the line-cutter 1 can be positioned such that a line 50 extends across the body 2 of the line-cutter, substantially normal to the plane of the blade 5. The line-cutter 1 may be able to cut line between 0.2mm and 4mm diameter, although thicker and thinner lines may be cut. The line may be a single strand, multiple strand, co-axial, twin-core cable, or any other suitable wire, cord, string or cable.

[0067] The pyro-mechanical actuator device 6 may be connected directly to a firing source, e.g. an electrical battery. or to a remote firing source. For example, the pyromechanical actuator device 6 may be connected to a remote control box 30 by electrical wiring 32. The control box 30 may be arranged to initiate the pyro-mechanical actuator device 6 upon command, for example via a switch 31, such that the piston (not shown) of the pyro-mechanical actuator device 6 pushes against the lever arm 3 and rotates the lever arm 3 about the pivot axis 4a. As a result, the blade 5 is rotated about the pivot axis 4a to cut through the line 50 [0068] The body 2 may include a shaped portion 45 on the opposing sides 27, 28 of the body 2, which are arranged to assist in-situ positioning of the line-cutler about a line into a "cutting position" prior to the line 50 being cut. The shaped portions 45 may be generally depressions, guides or channels formed into each side of the body 2 of the line-cutter 1, either side of the lever arm 3, as shown in Figures 4 and 5. The shaped portions 45 may comprise a pair of inclined walls 46, 47 that meet at an apex 48. The shaped portion 45 may be generally V-shaped.

[0069] It will be seen in Figure 4 that the walls of the body 2 may extend up so as to prevent the line from moving past the knife, towards the pivot axis 4a, and preventing the line from being trapped between the body 2 and the lever arm 3.

[0070] The inclined walls 46, 47 generally form an angle of between 30 degrees and 150 degrees to each other, although preferably form an angle of around 90 degrees to each other.

[0071] In alternative examples, the shaped portions 45 may not be V-shaped. For example, the shaped portions may be curved or slotted.

[0072] The shaped portions 45 assist in locating the line-cutler 1 about a target line 50 within the swing radius of the blade 5, i.e. into a cutting position, so as to ensure the blade 5 engages the line 50 when the lever arm 3 and blade 5 are actuated by the pyromechanical actuator device 6. Upon engagement of the blade 5 with the line 50, the shaped portions 45 will also provide a reactive force to allow the blade 5 to cut through the line 50.

[0073] The body 2 may be substantially hollow, such that a space is formed between the two sides 27, 28 of the body 2. This space allows the blade 5 to swing right-through the line 50. This can provide a cleaner cut of the line.

[0074] The body 2 may include a depression 40 formed into the body 2 arranged to accept the lever arm 3 and blade 5 in the latter portion of the blade 5 swing. The blade 5 may be arranged to impact a base 41 of the depression 40, stopping the blade 5. The depression 40 may safely house the blade 5 following actuation of the pyro-mechanical actuator device 6, thereby preventing the blade 5 from cutting an unintended item and protecting the user from inadvertently touching the blade 5.

[0075] The line-cutter I may be designed such that the blade 5 does not impact the body 2 at any stage of its rotation, for example the rotation of the blade 5 may be restricted by the lever arm 3 impacting the base 41 or other part of the body 2 prior to the blade 5 impacting the base 41. This can reduce blunting of the blade 5.

[0076] Figures 6 and 7 show a top and bottom view of the line-cutter, respectively. In particular, these figures show a first side 37 of the arm 3 may be substantially flush with the first side 27 of the body 2 and a second side 38 of the arm 3 ay be spaced from the second side 28 of the body. This gap is formed between the body 2 and the lever arm 3 along a portion of the length of the lever arm 3. The gap may be sized to be approximately as wide as the thickness or diameter of the line to be cut, as will be explained below.

[0077] The gap may be formed by a chamfered section 35 of the lever arm 3, which reduces a width of the lever arm 3, such that the width of the lever arm 3 is smaller than the width between adjacent sides of the body 2 along at least a portion of the lever arm 3.

[0078] The chamfered section 35 extends from a wide section 34 of die lever arm 3, nearest a tip end of the second end 12 of the lever arm 3. to a narrow section 36 of the lever arm, nearest the tip end of the first end 11 of the lever arm 3. The maximum width of the wide section 34 is greater than the maximum width of the narrow section 36 in a direction normal to the plane of the blade 5. The narrow section 36 may have a parallel side facing the body 2. Alternatively the narrow section may have a tapered side facing towards the body 2. The tapered side may accommodate a range of different line thicknesses or diameters, yet may still securely clamp the cut line. Yet further alternatively, the lever arm 3 may be arranged on a 'rising hinge' about the picot axis 4a. The lever arm 3 may be arranged to translate relative to the body in the direction along of the pivot axis as the arm rotates about the pivot so as to cause the space between the second side of the arm and the second side of the body to reduce. This arrangement may accommodate a range of different line thicknesses or diameters, yet may still securely clamp the cut line.

[0079] This gap between the body 2 and the lever arm 3 may be aligned with the shaped portion 45 of the body 2, such that the line cutter 1 may be aligned with the position of a line 50 immediately prior to actuation. Typically the line-cutter 1 will be held so that the line 50 is adjacent the apex 48 of the shaped portion 45 immediately prior to actuation, such that a portion of the narrow section 36 of the lever arm 3 is aligned with the apex 48 of the shaped portion 45.

[0080] The gap is formed at an opposite side of the lever arm 3 to the blade 5, i.e. the blades is attached to the first side 37 of arm 3, as shown in Figure 7. The gap is arranged to allow a line 50 to be pulled down into the gap between the body 2 and the lever arm 3, thereby trapping one end of the line 50 between the body 2 and the lever arm 3 so that it is restricted from exiting the grip of the lever aim 3 and thereby prevented from reconnecting with the other end of the line 50.

[0081] The line 50 may alternatively/additionally be bent as it is trapped in the gap between the body 2 and the lever arm 3. In this case, even if the line 50 were to be released from the grip of the lever arm 3. the bent line 50 would be less likely to reconnect with the other end of the line 50.

[0082] In alternative examples, the lever arm 3 may have a substantially constant width such that there is no chamfered section 35 between a wide section 34 of the lever arm 3 and a narrow section 36 of the lever arm 3. In this case, a gap may exist along the entire length of the lever arm 3. Alternative, a gap may be formed by increasing the width of a section of the body 2.

[0083] In some examples, the line-cutter 1 may include a retaining device 49, such as a hook 49, connected to the body 2 or lever arm 3. Figure 8 shows a hook 49 pivotally connected to the body 2 and arranged to releasably hold a line. The retaining device 49 can hold the line within the arc of the blade 5, for example the retaining device 49 can hold the line within the shaped portion 45 of the body 2. This helps to ensure an accurate and clean cut.

[0084] The line-cutter 1 may be housed prior to use in a webbing pouch (such as a Molle pouch), either alone or in a set of line-cutters 1 and with at least one accompanying pyro-mechanical actuator device 6. The line-cutter 1 may alternatively be held and protected inside a case 60. Figure 9 shows three line-cutters la, lb, lc held in a common case 60. As previous mentioned, the fixture 7 of these line-cutters I may be attached to the body 2 by screws 17, however it will be clear to the skilled person that the case 60 is equally suitable for housing line-cutters in which the fixture 7 has a threaded end 7a that screws into a corresponding threaded hole in the body 2 of the line-cutter 1, as shown in Figure 1.

[0085] The line-cutters la, lb, I c in the pouch or case 60 may be substantially the same, or the line-cutters la, lb, lc may each be tailored for cutting different types of line, for example lines of different materials and diameters.

[0086] As previously discussed, the line-cutter 1 may include a connector 15 (See Figures 1 and 2). The connector 15 may be suitable for connecting the line-cutter 1 to various supporting devices.

[0087] Figure 10 shows an example in which the line-cutter 1 is connected, via the connector 15, to the robot arm 75 of a robot 70. Figure 11 shows an example in which the line-cutter 1 is connected, via the connector 15, to a tripod 80. The line-cutter 1 may be connected to any suitable device, such as a lanyard (not shown), or may use the stand 18 in order to self-stabilise, as shown in Figure 3. The line-cutter 1 may have one or more hooks or eyelets for example, across top of body, to attach the line-cutter to a lanyard or line, or variable height cord.

[0088] It will be clear to the skilled person that the examples described above may be adjusted in various ways. hi particular, features of the wire-cutters described above may be appropriately combined. For example, in some examples the line-cutter 1 includes a wedge (not shown) removably positioned beneath one end of the lever arm 3, for example under the second end 12 of the lever aim 3. The wedge substantially prevents movement of the lever arm 3, for example when the line-cutter 1 is being stored or carried.

[0089] Where the word 'or' appears this is to be construed to mean 'and/or' such that items referred to are not necessarily mutually exclusive and may be used in any appropriate combination.

[0090] Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS1 A line-cutter for cutting a line, comprising: a blade attached to an arm and moveable relative to a body of the line-cutter, wherein the body includes an attachment portion for attaching a pyromechanical actuator device with a fully contained pyrotechnic or propellant charge to drive a piston arranged to move the blade relative to the body, via movement of the arm, so as to cut a line when the pyro-mechanical actuator device fires, wherein the blade is attached to a first end of the arm, the piston is arranged to contact a second end of the arm, and the arm is pivotally coupled to the body.
2. A line-cutter according to claim 1, wherein the arm is pivotally coupled to the body at a pivot location between the first end and the second end.
3. A line-cutter according to claim 2, wherein the pivot location is closer to the second end of the arm than the first end of the arm.
4. A line-cutter according to any preceding claim, wherein, upon actuation, the line-cutter is arranged to substantially fix a line between opposing surfaces of the arm and the body when a line is cut.
5. A line-cutter according to any preceding claim, wherein, upon actuation, the line-cutter is arranged to press a line between opposing surfaces of the arm and the body so as to bend the line.
6. A line-cutter according to any preceding claim, wherein the body includes a first side and a second side, and the aim is moveable in a space between the first and second sides.
7. A line-cutter according to claim 6, wherein the first and second sides are arranged to accommodate a line extending across the space.
8. A line-cutter according to claim 7, wherein the first and second sides are shaped to assist in locating a target line into a cutting position, preferably wherein the first and second sides include a generally V-shaped portion.
9 A line-cutter according to any one of claims 6 to 8, wherein a first side of the arm is substantially flush with the first side of the body and a second side of the arm is spaced from the second side of the body.
10. A line-cutter according to claim 9, wherein the blade is attached to the first side of arm.
11. A line-cutter according to any preceding claim, wherein the blade is a linear blade.
12. A line-cutter according to any preceding claim, wherein the body includes a base configured to house the blade upon actuation.
13. A line-cutter according to any preceding claim, wherein, upon actuation the arm is configured to be substantially fixed in an actuated position.
14. A line-cutter according to any preceding claim comprising a pyro-mechanical actuator device.
15. A line-cutter according to claims 13 and 14, wherein, upon actuation, the pyromechanical actuator device is configured to fix the arm in the actuated position.
16. A line-cutter according to claim 15, wherein the arm is arranged to be released from the actuated position by removal of the pyro-mechanical actuator device.
17. A line-cutter according to any one of claims 14 to 16, wherein the pyre-mechanical actuator device is releasably attached to the attachment portion and/or wherein the piston is arranged to frictionally engage the second end of the arm.
18. A line-cutter according to any one of claims 14 to 17, wherein the pyromechanical_ actuator device is a linear actuator.
19. A line-cutter according to any one of claims 14 to 18, wherein the piston has a stroke length of between 5mm and 20mm and/or wherein the piston travels the stroke length in less than 25ms.
20. A line-cutter according to any preceding claim, wherein the blade is formed of a non-conductive material, preferably ceramic material.
21. A line-cutter according to any preceding claim, comprising a connector for connecting to a lanyard, tripod, or robot.