Abstract: An automatic doner kebab cutting robot comprises; position sensors perceiving positions of the engine to introduce to the processor providing rotation movements of first engine providing vertical movement of cutting rod in second axis, a second engine providing horizontal movement of cutting rod in third axis, an engine providing movement of the knife of cutting rod in first axis, an engine providing rotation movement of doner kebab skewer in fourth axis, at least one scanner and/or laser perceiving starting point, height and diameter of doner kebab on it to introduce to the processor, at least 1 temperature sensor perceiving the value achieved by measuring temperature of doner kebab to introduce to the processor, a scanner and/or laser, control system (PLC/PIC) sending commands transferred by position sensors and temperature sensors and in this direction, to make furnace, doner kebab skewer, cutting rod and cutting knife it is connected to, move synchronously.

Abstract: According to one aspect, a system for midair deployment of payload may include an aerostat including an inflatable structure, at least one tether, and a trigger, the at least one tether extending between the inflatable structure and the trigger, and at least one unmanned aerial vehicle (UAV) including wings, the at least one tether mechanically coupling the at least one UAV to the inflatable structure, and the trigger actuatable to release mechanical coupling of the at least one tether between the at least one UAV and the inflatable structure in midair.

Abstract: According to one aspect, a system for midair deployment of payload may include an aerostat including an inflatable structure, at least one tether, and a trigger, the at least one tether extending between the inflatable structure and the trigger, and at least one unmanned aerial vehicle (UAV) including wings, the at least one tether mechanically coupling the at least one UAV to the inflatable structure, and the trigger actuatable to release mechanical coupling of the at least one tether between the at least one UAV and the inflatable structure in midair.

Abstract: A roller shade comprising a roller tube, a shade material attached to the roller tube, and a shade drive unit adapted to rotate the roller tube to lower or raise the shade material. The shade drive unit comprises a spring adapted to counterbalance the shade drive unit, a spring carrier, and a spring fastener. The spring carrier comprises a cylindrical barrel, wherein one of the first and second ends of the spring is concentrically positioned over the cylindrical barrel of the spring carrier. The spring fastener comprising a body having a curved bottom surface adapted to be positioned over one of the first and second ends of the spring and attached to the cylindrical barrel of the spring carrier.

Abstract: An energy absorption device for a vehicle steering column comprising a metal band and an adjustable deformation unit through which the metal band extends. The deformation unit is a rotatable hollow roller having a first contact surface inside the hollow roller that is separated from an outer contact surface by an outlet slot. The metal band passes through an inlet slot into the interior of the roller, and then through the outlet slot leaves the roller, in a manner that that said metal band is entirely deformed along an S-shaped curve.

Abstract: A tensioner comprising a base, a pivot arm pivotally mounted to the base, a spring disposed between the pivot arm and the base, an arcuate damping member engaged on one end of the spring, the arcuate damping member frictionally engaged with the base, a pulley journalled to the pivot arm on a shaft, the pivot arm comprising stamped metal and a rolled edge and one or more reinforcing ribs, and the spring and the shaft being laser welded to the pivot arm.

Abstract: A torsion spring assembly according to the invention includes a torsion spring having a cylindrical spring body of wound spring wire and with a plurality of torsion spring windings, and having first and second torsion spring ends for taking up forces in a direction of rotation, and a damping spring abutting the torsion spring on the inner side and having a cylindrical spring body of wound spring wire and with a plurality of damping spring windings, and having first and second damping spring wire ends, wherein the damping spring windings have their outer sides extending partially into the space formed between two respectively adjacent torsion spring windings and abutting in particular rounded, round or beveled inner abutment areas of respectively adjacent torsion spring windings with substantially radially outwardly directed bias.

Abstract: The present disclosure describes a wrap spring torque nipple that includes a first helical spring, a second helical spring, and a middle portion connected to and between the first helical spring and the second helical spring. The first helical spring and the second helical spring have different rotational helix orientations, and the first helical spring is configured to receive an input shaft and the second helical spring is configured to receive an output shaft, wherein the wrap spring transfers rotational power up to a defined torsional value from the input shaft to the output shaft.

Abstract: An auxiliary cutting implement for attachment between a broadhead and arrow shaft includes preferably two or more coils each having two cutting edges formed along their opposite elongated side edges. As the coils pass through the animal they unroll and slice through animal flesh in all directions. The coils are biased toward their rolled position which increases the multi-directional movement of the coil and cutting edges through the animal resulting in a large cutting area and fast kill as compared to the broadhead alone.

Abstract: A torsion assembly has a connection member and a torsion spring. The connection member has a connection segment and a holding protrusion. The connection segment has a connection hole. The holding protrusion is formed in the connection hole. The torsion spring has a spring body and a connection leg. The connection leg is connected with the connection segment of the connection member, and has a rod segment, a bent segment, and a hook segment. The connection leg is kept from escaping out of the connection hole by the holding protrusion.

Abstract: A tensioner uses a low rate torsion spring in a first stage and a high rate torsion spring in a second stage to maintain tension in a chain or belt. The first stage is connected to the second stage by a torque coupling. The high rate torsion spring is maintained in an energized state between a ground and a dead stop to store energy and to provide tension under high loads. In some embodiments, the torque coupling is a damper. In other embodiments, the torque coupling is a clutch. A method stores energy in a high rate torsion spring of a tensioner.

Abstract: A method includes a spiral forming step causing a substantially linear elongated member, conveyed toward one side in a longitudinal direction of the elongated member by a pair of conveying rollers, to be engaged at one side in a second direction with a pressing member movable in the second direction so that a spiral body including the fixed coil part, the first movable coil part and the second movable coil part is formed from the linear elongated member. The spiral forming step is configured to control the position of the pressing member with respect to the second direction, based on a signal from a rotational speed sensor detecting the rotational speed of the conveying roller, a relationship between a position in the longitudinal direction of the elongated member that is engaged with the pressing member and the position in the circumferential direction after the spiral body is formed.

Abstract: A tensioning device comprising a receiver housing, a lever arm mounted on the receiver housing and rotatable with respect to the receiver housing around a first rotation axis, a pulley mounted on the lever arm and rotatable with respect to the lever arm around a second rotation axis parallel to the first rotation axis, and a spring mounted between the receiver housing and the lever arm and adapted to apply a torque for rotating the lever arm around the first rotation axis. The receiver housing and the lever arm are screwed together around the first rotation axis. The spring applies an axial damping effort, parallel to the first axis, on cooperating threaded portions respectively provided on the receiver housing and on the lever arm.

Abstract: A damper restricts pivot pin rotation associated with operation of an operating section, wherein friction resistance that impedes the pivot pin rotation is changed in stepped fashion. When the pivot pin rotates in direction ? due to depression of an accelerator pedal, a slide cam shifts an edge section of an inclined cam surface away from a rotating cam while staying in contact with a gradual first inclined region of the rotating cam's inclined cam surface. Torque around the axis of the pivot pin is produced, the entire region of the slide cam's inclined cam surface comes into contact with a steep second inclined region of the rotating cam's inclined cam surface upon accelerator pedal depression to a prescribed position (the pivot pin has rotated by a prescribed angle ?1 in direction ?), and the torque around the axis of the pivot pin rapidly increases.

Abstract: A low profile, alignment assembly for a media feed roll assembly using torsion spring biasing. The alignment assembly has a first and a second spaced bushings mountable to a frame. Each bushing has a circular collar and a cradle positioned along a common centerline for rotatably holding a driven first and an opposed second shaft on the common centerline. A first and a second torsion spring mount around the second shaft adjacent to the first and second bushing, respectively, and each has a pair of legs extending tangentially therefrom, attachable to the frame or respective bushing and forming a substantially planar profile. Each torsion spring biases the second shaft toward the first shaft along the common centerline and, as a media sheet moves between the first and second shafts, allows the second shaft to move within the cradles radially away from the first shaft along the common centerline.

Abstract: A tilt mechanism for an electronic display including a torsion spring, the torsion spring providing a spring torque to balance a monitor torque due to weight of the monitor. The tilt mechanism allowing an electronic display to be positioned at a variety of tilt angles within a range of tilt angles. Such a tilt mechanism allowing an electronic display to be positioned at positive and negative tilt angles within the range of tilt angles. Methods of using a tilt mechanism.

Abstract: A spreader spring comprising: (a) a locking arm that connects the spreader spring to a brake component; (b) a retraction arm; and (c) a bias device located between the locking arm and the retraction arm; wherein the bias device includes six helical loops or more that store energy during a brake apply and once the brake apply is complete assist in retracting a brake pad.

Abstract: A dual stage accelerator pedal spring assembly is provided that allows the transition point between stroke stages to be adjusted in order to control pedal travel within the first stroke stage and provide the driver with a customizable accelerator pedal interface. The spring assembly, which uses two springs exhibiting different spring force, allows adjustment of the relative positions of the two springs in order to control the transition point between the first and second pedal stroke stages.

Abstract: An accelerator pedal device having a pedal arm working in conjunction with an accelerating pedal, a housing to rotatably support the pedal arm around a prescribed pivot axis line between a rest position and a maximum applied position, a hysteresis generation mechanism that comes in contact with the vicinity of an upper end of the pedal arm to generate hysteresis in a pedal force of the accelerator pedal, and an active control mechanism to push back the pedal arm toward the rest position under prescribed conditions between the pivot axis line and the hysteresis generation mechanism. The active control mechanism includes a drive source provided in the housing, and a return lever that is rotated in the same direction as the direction of the swinging of the pedal arm in conjunction with the drive source and is detachably engaged with the vicinity of the upper end of the pedal arm.

Abstract: A spring hook structure includes: a torsion coil spring including a coil portion and a first arm and a second arm extending from each side of the coil portion; and a rotation support pin by which a cap is rotatably supported on an exterior case. The rotation support pin is inserted into the coil portion. The first arm is hooked on a first hook surface of the exterior case, and the second arm is hooked on a second hook surface of the cap. At least one of the exterior case and the cap is provided with a regulation wall at a position not interfering with the arm moving along the hook surface due to flexural deformation of the coil portion but interfering with the arm moving along the hook surface due to flexural deformation of the arm.

Abstract: A spring (10), for a locking device of a vehicle seat, is designed as a yoke spring defining an axis (A) and made of a spring wire. A cross section diameter (q) has one leg (10a) on each of both ends of the spring wire. The two legs (10a) can pivot relative to each other in a circumferential direction of the axis (A), thereby transitioning the spring (10) from a relaxed state into a tensioned state. At least one first winding (10b) is provided between the legs (10a) that is wound completely around the axis (A) and having a winding diameter (di) in the relaxed state. At least one adjacent second winding (10b) is provided between the legs (10a) and disposed offset along by the axis (A) by a pitch (h), wherein the second winding (10b) may optionally be wound not fully about the axis (A). The second winding (10b) has a winding diameter (d2) in the relaxed state. The pitch (h) is less than the cross section diameter (q).

Abstract: An object of the present invention is to provide a spiral spring assembly that is capable of suppressing lateral force generated in a central shaft. A spiral spring assembly (1) includes a central shaft (2), a spiral spring (3) that is disposed on the periphery of the central shaft (2) and includes an outer end (3a), an inner end (3b), and a spiral portion (3c) that connects the outer end (3a) and the inner end (3b) in a spiral form; an inner end fixing member (4) to which the inner end (3b) is fixed so as to be capable of transmitting torque; and an outer end fixing member (5) to which the outer end (3a) is fixed, and which is capable of moving relative to the inner end fixing member (4) within a predetermined section extending from a first state to a second state. The outer end (3a) is fixed to the outer end fixing member (5) so as to be capable of transmitting torque and suppressing a lateral force that is generated in the central shaft (2) in a predetermined state within the predetermined section.

Abstract: A spring for windshield wiper assemblies is comprised of a resilient rod having a plurality of sections adapted to removably attach to a windshield wiper assembly of a vehicle. The rod includes a first hook section at one end section thereof; a second hook section located at an opposite end section thereof. An intermediate coiled section attached to and located adjacent the first hook section, and a connector section defining an axis along its length and connected between the intermediate coiled section and the second hook section.

Abstract: An externally mounted mechanical device for mechanically closing a pressurized tank or cylinder valve, such as a grill tank, is provided. The device comprises a securing mechanism, a rotatable mechanism having a handle recess to receive a handle of pressurized tank or cylinder valve, and a torsional spring, wherein the torsional spring is configured to store potential torsional force and then release the torsional force by way of a timed release mechanism. The mechanical device comprises a securing device for securing the mechanical device to a tank or cylinder. Torsional force may be stored in torsional spring by way of a ratchet and pawl that also is configured to release the stored torsional force by way of a timed release.

Abstract: A modular spring assembly configured for interconnection with a folding tool is provided. The modular spring assembly may be positioned coaxially with a pivot axis of the folding tool and interconnected to the folding tool. In one embodiment, the modular spring assembly includes a cup and a torsion spring.

Abstract: A helical torsion return spring and a throttle body assembly for urging a throttle plate of a throttle body assembly to a default position when a throttle motor of the throttle body assembly is disabled. The return spring includes a middle portion, a first end portion, a second end portion, a first spring leg, and a second spring leg. The throttle body assembly includes a throttle shaft, a first bushing, a second bushing, and the spring defined above. A first end portion center axis defined by the first end portion and a second end portion center axis defined by the second end portion are offset from a middle portion center axis defined by the middle portion.

Abstract: A combination torsion spring is configured such that a predetermined reaction force is generated in a coil circumferential direction without a center of a wound coil tilting even when applied with a load. A first torsion spring and a second torsion spring of the combination torsion spring are each provided with a coil. Each coil is formed by spirally winding a copper wire in a different winding direction from one another. The inner diameter of the coil of the first torsion spring is approximately the same as the outer diameter of the coil of the second torsion spring. In the combination torsion spring, the coil of the second torsion spring is inserted into the coil of the first torsion spring.

Abstract: A motor with a braking mechanism for an actuator includes a main body, a rotating shaft and a braking mechanism. The rotating shaft is disposed through the center of the main body. The braking mechanism includes a friction element and a torsion spring, the friction element is arranged on the external periphery of the rotating shaft, and the torsion spring is elastically clamped at an outer edge of the friction element and an end of the torsion spring is fixed to main body. When the rotating shaft rotates in one direction, the torsion spring abuts the friction element to brake and decelerate the rotating shaft. With small wear and tear of the torsion spring, the service life can be extended. With a large contact area between the friction element and the rotating shaft, a good braking effect can be achieved.

Abstract: A folding device includes a main body, a cover, and a torsion spring. The cover is rotatably connected to the main body and capable of covering the main body, the cover comprising a supporting member. The torsion spring renders the cover spring-loaded, to rotate the cover open from the main body. The torsion spring includes a coil, a first arm and a second arm. The first arm includes a first portion extending from one end of the coil along a first direction that is perpendicular to an axis of the coil; and a second portion extending from the end of the first portion along a second direction different from the first direction. The first portion and the second portion support the supporting member from different positions and different lengths when the cover is opened. The second arm restricts against the main body.

Abstract: A bicycle rear derailleur includes a stationary member, a base member, a linkage mechanism, a movable member, a chain guide and an inner cable fixing portion. The stationary member non-movably attached to a bicycle frame and includes an outer cable receiving portion configured to receive an outer sheath of a control cable assembly. The base member is pivotally coupled to the stationary member about an axis spaced apart from a hub axis of a rear wheel. A movable member at one end of the linkage mechanism is movable relative to the base member in response to an inner cable that is attached to a portion of the linkage mechanism. The base member can move in response to tension applied by the inner cable without moving the chain guide which is coupled to the movable member.

Abstract: The invention relates to a winding shaft for a roller blind device with a winding tube (2) and a torsional tensioning device (7) that, with a first end (7a), is coupled to the winding tube (2) in a manner that enables it to rotate in relation thereto. The torsional tensioning device (7), at least with a second end, is coupled to the winding tube (20 so that it is rotationally fixed and axially displaceable in relation thereto.

Abstract: In a pull arrangement including a housing with a guide structure movably supporting a carrier element which has a park position at one end of the guide structure and a rest position at the other end and a reversing structure is provided at the other end of the guide structure and a tension spring extending around the reversing structure is connected with one end to the carrier element and the opposite end to the housing for moving the carrier element to the end position, the tension spring comprises an area of high spring stiffness where it extends around the reversing structure and an area of low spring stiffness where the spring is connected to the housing away from the reversing structure.

Abstract: A second spiral spring is smaller than a first spiral spring and is housed in an open space in the center of the first spiral spring. A folded portion that is formed in an inner end of the first spiral spring and a folded portion that is formed in an outer end of the second spiral spring are hooked in a latch plate, under tension, that is cut and raised from a side. A receiving space is formed between the latch plate and an initial winding portion that starts winding in a curved shape from the inner end of the first spiral spring so as to house a tip of the folded portion of the outer end of the second spiral spring that is hooked in the latch plate.

Abstract: A torsion spring assembly includes a torsion spring body and a fixed base. The torsion spring body has a first coil part and a second coil part. The first coil part connects to the second coil part. The fixed base has a first fixed arm and a second fixed arm. The first coil part is wound around the first fixed arm and the second coil part is wound around the second fixed arm. The winding direction of the first coil part is perpendicular to the winding direction of the second coil part. A portable electronic device with the torsion spring assembly is also disclosed.

Abstract: An elastic device which can be used where there is an interval smaller than the thickness of the spring in a moving range of an arm member. The elastic device includes a spring, a first arm member for receiving at least a part of the spring inside, supporting or fixing an end of the spring, and including a housing portion having an opening along one side and an extension extending outside of the housing portion, and a second arm member for supporting or fixing the other end of the spring in at least one end, including a rotation-supporting portion installed rotationally to the first arm member while overlapping with the spring in the housing portion and an exposing-extension portion connected to the rotation-supporting portion and exposed to outside of the housing portion through the opening.

Abstract: This invention relates to a traction assembly for a vehicle which uses an endless traction band and a plurality of wheels for propulsion. More particularly, the traction assembly comprises a sprocket wheel which has a different size and number of sprocket teeth depending on whether the traction kit replaces the front wheels or the rear wheels of the vehicle. The sprocket wheel of the traction kit can also be configured such that its sprocket teeth are laterally offset. The traction kit can also comprise an anti-torque system that prevent physical contact between the traction kit and the vehicle and that can bias the position of the traction kit in order to improve the steering performance. Finally, the traction assembly can comprise a pivotable extension which lengthens the traction assembly and improves its traction capabilities.

Abstract: A sliding apparatus includes a first sliding member and a second sliding member slidable relative to the first sliding member. A first resilient member and a second resilient member are connected between the first and second sliding members. The first and second resilient members overlap with each other to provide the better sense of damping for operators.

Abstract: A spring (10), for a locking device of a vehicle seat, is designed as a yoke spring defining an axis (A) and made of a spring wire. A cross section diameter (q) has one leg (10a) on each of both ends of the spring wire. The two legs (10a) can pivot relative to each other in a circumferential direction of the axis (A), thereby transitioning the spring (10) from a relaxed state into a tensioned state. At least one first winding (10b) is provided between the legs (10a) that is wound completely around the axis (A) and having a winding diameter (di) in the relaxed state. At least one adjacent second winding (10b) is provided between the legs (10a) and disposed offset along by the axis (A) by a pitch (h), wherein the second winding (10b) may optionally be wound not fully about the axis (A). The second winding (10b) has a winding diameter (d2) in the relaxed state. The pitch (h) is less than the cross section diameter (q).

Abstract: Disclosed are an actuator capable of preventing interference caused by torsion to thereby improve stability and reliability, and a spring used for the actuator. The actuator includes a first molding part, a second molding part being rotatably connected in an end of the first molding part, and a spring member including a first spring arm that is fixed to the first molding part and a second spring arm that is fixed to the second molding part. In this instance, the first spring and the second spring arms are integrally connected to each other.

Abstract: A bearing apparatus includes a coil spring having a center portion in which a wire is wound at a predetermined pitch, and end turn portions arranged at both end portions of the center portion. Each of the end turn portions is formed by winding the wire at least three turns with a pitch which is smaller than the predetermined pitch of the center portion. A bearing member has a main body with an opening for supporting a shaft, and a connecting portion for connecting the coil spring to the main body. The main body and the connecting portion are integrally formed from a resin material by molding, and the end turn portion of the coil spring is connected to the connecting portion through molding of the main body and the connecting portion. The connecting portion of the bearing member has an inner connecting portion which protrudes into an inside of the end turn portion of the coil spring, and an outer connecting portion which surrounds an outside area of the end turn portion of the coil spring.

Abstract: A device for providing rotational and axial locking capability using a wireform with at least one wrap. The device requires very low actuation forces. The wireform can be constructed with end features that provide a specific tension such that when the device is engaged a differential slip torque in a clockwise and counterclockwise rotational direction is developed.

Abstract: The elastodynamic energy accumulator-regulator comprises a sheet (1) that is wound or capable of being wound in radioida spiral form with increasing or decreasing curvature along the length of the spiral, capable of absorbing energy at variable torque and supply a practically constant torque in broad working areas The laminate or set of sheets that are wound or capable of being wound about themselves as a spring has variable thickness and/or width and/or reinforcement along its length, and is held at both ends. The laminate or set of sheets is made of composite materials with polymer matrix and fiber reinforcement This elastodynamic energy accumulator-regulator has application as an energy accumulator or regulator in many applications such as wind energy production and other renewable energies, applications in transport, applications in uninterruptible power supply systems, applications in electric network regulation, etc.

Abstract: A hydraulic tensioner comprising a piston slidably inserted in a piston bore of a housing having rack teeth on an outer circumference thereof, a piston spring biasing the piston in a protruding direction, a pawl member having teeth engageable with the rack teeth of the piston to permit protruding movement of the piston but to block reverse movement of the piston provided in a pawl hole of the housing, and a pawl spring in a pawl spring hole of a generally elliptical cross-section that biases the pawl member in an engaging direction of the teeth of the pawl member with the rack teeth of the piston. A long axis of the generally elliptical cross-sectional shape of the pawl spring is oriented toward an axial direction of the piston. Wire portions of the pawl spring substantially follow the long axis that contacts an upper surface of the pawl member.

Abstract: The invention provides an operational mechanism for a movable body in which, after a movable body is in an opened state, the movable body can return to a closed position, including a movable body rotatably attached to a support and rotatable between an engaged position, a closed position, and an open position; a rotating member rotatably attached to the support, that rotates due to movement of the movable body to the engaged position; a biasing member, one end of which is attached to the movable body, and the other end of which is attached to the rotating member; and an operation member, which rotates the rotating member, changes the biasing position of the biasing member with respect to the center of rotation of the movable body, and generates in the biasing member a rotational force that moves the movable body to the closed position or the open position.

Abstract: A spring device includes a tubular seat defining a shaft hole therethrough, a shaft, and a torsion spring. The shaft hole has a positioning hole section and a guiding section. The guiding section has a diameter smaller than that of the positioning hole section. The tubular seat further has a keyway that is in spatial communication with the guiding section of the shaft hole. The shaft has a shaft body and a key. The shaft body is extended through the shaft hole and is movable axially relative to the tubular seat between first and second axial positions. The shaft body is rotatable relative to the tubular seat when the shaft body is at the second axial position so as to accumulate a winding force in the torsion spring. The tubular seat further has a key stop that abuts against the key so that the key is offset from the keyway when the shaft body is at the first axial position.

Abstract: Disclosed is a refrigerator. The refrigerator includes a body, a refrigerator door for opening/closing a front surface of the body, with the refrigerator door having an opening, an auxiliary door for opening/closing the opening of the refrigerator door, and a damping unit coupled to a hinge shaft of the auxiliary door to control an opening/closing speed of the auxiliary door. The damping unit includes a case, a rotating member rotatably installed in the case, oil filled in the case to apply resistance against rotation of the rotating member, a fixing member coupled to an end portion of a rotating shaft of the rotating member to rotate together with the rotating member, and an elastic member provided between the case and the fixing member to apply elastic force to the fixing member in a direction opposite to an opening direction of the auxiliary door. It is possible to stably rotate the auxiliary door while controlling the rotational speed of the auxiliary door.

Abstract: The automatic document transport device 2 comprises a device main body 4, an opening and closing body 20 pivotally supported by the device main body 4 about a support shaft 22 between a closed position and an open position, and a helical torsion coil spring 30 that urges the opening and closing body 20 positioned at the closed position in the open direction. The helical torsion coil spring 30 is provided and arranged at a position separate from the support shaft 22.

Abstract: An actuator configured to actuate a member. The actuator optionally including capabilities for storing and releasing kinetic energy. The actuator being suitable for use in any number of environments, including but not limited to facilitating seat folding operations.

Abstract: A low cost, flexible, torqueable structure for use as at least a portion of a medical device comprises a coil formed of a wound element. The coil includes a plurality of adjacent windings. Connected portions of a region between the adjacent windings are formed (by, for example, laser welding) such that torque can be transmitted between adjacent windings.

Abstract: The invention to which this application relates is to a mechanism for the tensioning of a spring, typically a coil spring (1) of the torsion type, said spring (1) having first (20) and second (22) arms which depend outwardly from either end of the coil and the spring (1) is provided to create a biasing force. The apparatus is typically a power tool and the invention provides an effective means of tension the spring (1) at the time of assembly of the tool by using components fitted as part of the tool.