Abstract: A power tool includes a switch moveable between a first position enabling activation of a motor and a second position disabling the motor. The power tool includes a trigger movably coupled to a housing of the power tool between an OFF position and an ON position. The switch moves from the second position to the first position in response to the trigger moving from the OFF position to the ON position. The power tool includes a trigger lock-off pivotably coupled to the housing between a lock position and an unlock position. The trigger lock-off is engageable with the trigger to inhibit movement of the trigger from the OFF position to the ON position when the trigger lock-off is in the lock position. The trigger lock-off allows movement of the trigger from the OFF position to the ON position when the trigger lock-off is in the unlock position.

Abstract: A shearing mechanism is provided including a pair of blade units comprising shearing blades respectively; and a motion mechanism configured to move at least one of the pair of blade units along a predetermined trajectory in such a manner that a velocity thereof does not become zero while maintaining a relative posture of the pair of blade units, wherein the pair of blade units are configured to cut an object by overlapping the shearing blades of each other during the motion.

Abstract: An electric working machine may include a support rod, a head unit, a position fixing mechanism, and a resistance member. The support rod may extend in a front-rear direction and include an attachment portion located at a front end of the support rod. The head unit may include a front tool, a motor configured to drive the front tool, and a head housing supporting the front tool and coupled to the attachment portion rotatably about a rotation axis. The position fixing mechanism may be configured to fix a rotation position of the head unit with respect to the support rod. The resistance member may be interposed between the attachment portion and the head housing with respect to a direction perpendicular to the rotation axis. The resistance member may be configured to provide a resistance force against rotation of the head unit with respect to the support rod.

Abstract: A hedge trimmer includes a blade assembly having a first blade and a second blade, a housing, a prime mover, and a transmission device. The first blade includes a first body portion and a plurality of first tooth portions, and the second blade includes a second body portion and a plurality of second tooth portions. The first blade includes a first connection assembly including a first driving portion and a first connecting portion, and the second blade includes a second connection assembly including a second driving portion and a second connecting portion. The first connecting portion and the first body portion form a detachable connection, the second connecting portion and the second body portion form a detachable connection, and the first connecting portion is at least partially located outside the housing.

Abstract: A cutting device for an agricultural harvesting machine including: a drive; a transmission arrangement having an input element drivingly connected to the drive and driven reciprocatingly by the drive along an input travel; and a knife having a plurality of cutting edges, the knife being drivingly connected to and driven by an output element of the transmission arrangement along an output travel longer than the input travel, is driven in a reciprocating motion in such a way that the cutting edges of the knife pass in each case at least two counter-cutting edges of the cutting device when moving in one direction along the entire output travel.

Abstract: A blower includes a first fan stage with a first housing that has a first plurality of stationary vanes and a first fan that has a first plurality of blades extending radially outwardly from a first hub. The first housing includes a first axial end and a second axial end opposite the first axial end. The blower also includes a second fan stage coupled to the first fan stage. The second fan stage includes a second housing with a second plurality of stationary vanes and a second fan that has a second plurality of blades extending radially outwardly from a second hub. The second fan stage includes a third axial end and a fourth axial end opposite the third axial end. The first hub and/or the second hub has a frustoconical shape that converges from the first axial end toward the fourth axial end.

Abstract: A method of manufacturing a blade set assembly, a blade set assembly, and a hair cutting appliance, wherein the method includes providing a base component including a stationary blade, providing a movable component comprising a cutter blade, providing a coupling element, the coupling element being arranged to be interposed between the base component and the movable component, providing a plastic contact bridge, arranging the stationary blade and the cutter blade at a defined relative assembly position, securing the assembly position between the stationary blade and the cutter blade, involving attaching the plastic contact bridge to one of the base component and the movable component, attaching a retaining portion of the coupling element to the other one of the base component and the movable component, and penetrating the plastic contact bridge with at least one insertion end of the coupling element.

Abstract: A negative pressure pneumatic hair clipper includes a housing and a hair cutting bit mounted on the head of the housing; a negative pressure turbine airway and a suction airway isolated from each other go all the way through the housing; a negative pressure turbine wind motor connected with the hair cutting bit is provided inside the negative pressure turbine airway and, when rotated, can drive the hair cutting bit to perform the hair cutting operation; a suction mouth of the suction airway is disposed near the hair cutting bit; the tail of the housing is connected with an airway hose that is in gas phase communication with the negative pressure turbine airway and the suction airway, with the other end of the airway hose connected with a vacuum cleaner capable of generating negative pressure airflow to drive the negative pressure turbine wind motor to rotate.

Abstract: An example system includes a cutting tool and a device configured to remotely control the cutting tool. The device is configured to establish a wireless communication with the cutting tool, and the cutting tool is configured to send a first signal to the device indicating that the cutting tool is enabled to be operated remotely responsive to the cutting tool receiving information indicating that a trigger is locked in an “on” state and a remote switch is in a first position. The device is configured to send a second signal to the cutting tool indicating a request to cause the cutting tool to perform a cutting operation responsive to receiving information indicative of actuation of at least one button of a user interface of the device.

Abstract: A chain saw unit and a method of constructing the same. The method includes the steps of obtaining: a) an endo-skeletal sub-frame assembly defining a plurality of mount locations; b) a plurality of operating components; and c) an outer housing assembly; directing one of the operating components laterally into an operative position at one of the mount locations at one of the sides of the endo-skeletal sub-frame assembly; placing at least one additional operating component into an operative position to define a main operating unit; and after directing the one of the operating components into its operative position, placing at least a part of the outer housing assembly in an operative position with respect to the endo-skeletal sub-frame assembly wherein the at least part of the outer housing assembly overlies part of the exposed surface area of the main operating unit and blocks access to the operatively positioned one component from the one side of the endo-skeletal sub-frame assembly.

Abstract: A drive for a hair trimmer include a transmission having a cam follower coupled to a drive lever by a bridge member, and a hinge having a mounting structure coupled to a first end of a plurality of webs, and a cross-bar coupled to a second end of the plurality of webs. A portion of the cross-bar encloses the bridge member to connect the transmission and the hinge.

Abstract: A vegetation trimming assembly has at least one cutting blade with a cutting edge that moves guidingly within a blade working space between facing first and second fixed surfaces. The first surface is defined in part by a body with a fixed shape, including a head and a stepped diameter shank with a larger diameter portion to guide movement of the one cutting blade and a smaller diameter portion that is threaded to engage a support defining the second surface. The body is selectively turned in opposite directions to thereby increase and decrease a depth of the blade working space.

Abstract: A hair clipper with a blade set, includes at least one stationary or one adjustable cutting comb and one shearing blade driven in oscillation in the transverse direction essentially parallel to the front edge of the cutting comb. The hair clipper may have a hair transport element, which has a transport toothing, which is arranged essentially along the cutting edge of the shearing blade at a distance from the cutting edge of the shearing blade. The shearing blade is arranged between the cutting comb and the hair transport element. The cutting edge of the shearing blade extends beyond the front edge of the hair transport element.

Abstract: Embodiments herein describe a tie strap with a hardened integrated rivet for a saw chain. The tie strap has a body with an integrated rivet extending therefrom and having a shoulder extending from the body and configured to engage a rivet hole of a connector link and a hub extending from the shoulder and configured to engage a rivet hole of an opposing tie strap. The shoulder has a high wear region and a low wear region disposed opposite from the high wear region, wherein the low wear region has a first hardness that is less than a second hardness of the high wear region. Generally, the high wear region extends circumferentially around the shoulder and is between about 90 degrees counter clockwise to about 90 degrees clockwise measured from a center point on the shoulder facing inward toward a center part of the body.

Abstract: A hedgetrimmer having a blade assembly that includes a sawblade for cutting through larger branches and other vegetative foliage. The blade assembly includes a reciprocating blade having an integrally formed sawblade portion that moves back and forth cutting motion. The other blade is fixed and includes a bevelled interior edge that helps debris being cut to pass over the blade and prevent getting stuck.

Abstract: The present disclosure relates to a hair cutting appliance (10), a blade set (20) for a hair cutting appliance (10), and to a stationary blade (22) for said blade set (20).

Abstract: A power tool, for example, a portable circular saw, includes a fan, a motor configured to rotate the fan, an output part or shaft driven by the motor, a motor housing that houses the motor, a grip housing connected to the motor housing, a trigger associated with the grip housing, and a brake member configured to brake a rotation of the motor, the brake member being mounted inside the grip housing. The brake member may be a resistive element of a rheostatic braking system. The housing and fan are configured such that cooling air is directed to cool the brake member.

Abstract: A reciprocating working machine has a lower blade and an upper blade overlapping each other. The lower and upper blades have respective elongated apertures slidably fit around lower and upper eccentric cams, respectively. The lower and upper eccentric cams are arranged at a 180-degree phase from each other. One of the upper eccentric cam and the lower blade has a beveled surface facing the other. The lower blade and the upper eccentric cam are relatively moved away from each other via the beveled surface.

Abstract: A hedge trimmer having a drive motor, a gear mechanism, and a blade arrangement with at least one cutter bar, which is driven in a reciprocating manner by the drive motor via the gear mechanism in a longitudinal direction. The blade arrangement includes a guide mechanism that extends over at least a part of the length of the blade arrangement. The guide mechanism is embodied as a molded part that includes a generally flat fastening portion and a profiled guide portion. The cutter bar is longitudinally movably held on the guide portion.

Abstract: Techniques for mounting contacts of a connector are provided. One technique involves actively and continuously monitoring contacts being used and the contacts not being used in a connector in order to determine potential dendrite growth and/or potential corrosion due to liquid intrusion or the like. Another technique includes lowering a bias voltage on a power contact and performing a system detect prior to enabling operational voltage/current on the contact.

Abstract: An electrically powered garden tool includes an electric motor mounted upright within an outer shell housing, a pair of relatively reciprocating shear blades assembled to be driven by operation of the motor through a crank mechanism provided within a lower portion of the outer shell housing, and a cooling fan assembled to be driven by operation of the motor for introducing outside air into an upper portion of the outer shell housing to exhaust the introduced air from a lower portion of the outer shell housing. In the garden tool, a downward exhaust opening is formed within a lower end peripheral wall of the outer shell housing enclosing the crank mechanism such that the air spouted by rotation of the cooling fan blows out downward from the downward exhaust opening to restrain the occurrence of blowing noise of the air.

Abstract: A hair clipper has a base structural housing with a blade set operably secured thereto. The blade set has a stationary blade and a reciprocating blade. The base has at least one support for a rotary motor. A flexible motor vibration and noise damper fits over half of the motor, and a motor cover is secured to the base structural housing over the vibration damper. A secondary housing cover is secured to the base structural housing over the motor cover.

Abstract: A hedge trimmer having a rear handle, a tubular handle and a blade arrangement with at least one cutter bar disposed in a cutter bar plane. An internal combustion engine drives the cutter bars in a reciprocating manner, and has a combustion chamber and a crankshaft mounted in a crankcase so as to be rotatable about an axis of rotation. The combustion chamber faces the rear handle, and the crankcase faces the blade arrangement. The blade arrangement has a longitudinal central axis, and the hedge trimmer has a longitudinal plane that is disposed parallel to the axis of rotation of the crankshaft and transverse to the cutter bar plane. The longitudinal central axis of the blade arrangement lies in the longitudinal plane of the hedge trimmer.

Abstract: A hair clipper has a base housing, a secondary housing cover, and a rotary motor or vibrator motor secured between the base housing and the housing cover. The rotary motor has a shaft and a cam secured to an end of the shaft, and the vibrator motor has a drive arm with a drive finger. A cam follower is operably connected to the cam or drive finger on a top side. The top side of the cam follower also has an elongated guide rail that is operably secured to a guide channel in a blade guide, which in turn is secured to the base housing. A reciprocating blade is operably secured to the bottom side of the cam follower, and a stationary blade is secured to the base housing adjacent the reciprocating blade.

Abstract: A hair trimmer has a base housing and a blade set having a stationary blade and a reciprocating blade. The base housing has a blade set support at one end. The support has a pair of spaced blade set support projections. A cam follower has spaced spring retainers near a bottom of the cam follower, and spaced spring end catches near an upper edge of the cam follower. A spring has elongated legs and a tension arm. The elongated legs extend under the spring retainers and into the spring end catches in the cam follower. A spring tensioner is secured in the base housing by a latch that engages a tensioner catch. The spring tensioner secures the tension arm so that the spring is under tension.

Abstract: An electric hair cutting apparatus having a motor for rotating a shaft, which, rotates an eccentric about the axis of the shaft, but not about the central axis of the eccentric, A cylindrical bearing is positioned around the eccentric. A drive tip is provided with a follower end which is shaped and positioned to engage with the bearing surrounding the eccentric. As the eccentric rotates, the bearing alternately pushes on left and right arms of the follower end of the drive tip, causing the drive tip to oscillate back and forth about a pivot point, The angle of the bearing with respect to the eccentric allows for generally continuous contact between the arms of the follower end of the drive tip with the bearing, even throughout the pivoting of the drive tip.

Abstract: A cutting assembly for a portable hand-held power driven working tool may include a first elongate cutting blade and a second elongate cutting blade. The cutting blades are arranged to be connected to a gear, causing the cutting blades to move in a reciprocal manner along a longitudinal axis of the cutting blades. The cutting blades are arranged to be mounted so that an interior surface of the first cutting blade faces towards and abuts on an interior surface of the second cutting blade. At least one of the cutting blades has a recess extending in a longitudinal portion of the interior surface of the cutting blades, such that a gap appears between the cutting blades when they are mounted in a face-to-face relationship. The gap prevents the flow of the grease from the gearbox beyond the position of the gap on the cutting assembly.

Abstract: A hedge trimmer having a drive motor, a gear mechanism, and a blade arrangement with at least one cutter bar, which is driven in a reciprocating manner by the drive motor via the gear mechanism in a longitudinal direction. The blade arrangement includes a guide mechanism that extends over at least a part of the length of the blade arrangement. The guide mechanism is embodied as a molded part that includes a generally flat fastening portion and a profiled guide portion. The cutter bar is longitudinally movably held on the guide portion.

Abstract: The invention relates to an animal shearing machine with a housing, a shearing head connected to the housing and a drive unit arranged in the housing. The drive unit comprises an electric motor and a reduction gear connected to the shaft of the electric motor. The shearing head of the animal shearing machine has a stationary shearing blade and a movable shearing blade. A planetary gear is used as reduction gear. The driven shaft of the planetary gear is arranged parallel, in particular coaxially to the shaft of the electric motor. If oscillatingly driven shearing heads are used, the drive unit comprises an eccentric connected to the driven shaft of the reduction gear and an oscillating lever. The oscillating lever is in engagement with the movable shearing blade via the first front end and with the eccentric via a sliding element in the area of the second rear end.

Abstract: The invention relates to a motor-driven cutting device with a double blade arrangement driven by means of a double eccentric arrangement having opposing oscillating blade movement, comprising an advantageous construction with a separate double eccentric group for the drive device that can form a uniformly operable front-part group, particularly in conjunction with the double blade arrangement at a particularly favorable cost, and that is advantageous for installing the front-part group in the production process and/or when replacing the preferably uniformly operable front-part group.

Abstract: A blade assembly of a hedge trimmer includes at least one cutting blade having cutting teeth. At least one portion of the cutting teeth are configured as protective teeth which, referred to the cutting blade axis, have an inner cutting region and from which an outer protective finger extends. The protective tooth is, referred to its tooth axis, configured unsymmetrically. The protective tooth has a cutting side and an opposite-lying holding side and a cutting edge in the cutting region on the cutting side and a holding edge on the holding side. The protective finger has a forward edge on the cutting side and a rearward edge on the holding side. Starting from the blade axis, the forward edge is inclined to the tooth axis and the rearward edge, starting from the blade axis, is inclined away from the tooth axis.

Abstract: In a hedge trimmer, a main body is configured of: a main body front portion on a front side (a side on which the cutting blade protrudes); a main body rear portion on a rear side; and a supporting portion for connecting them on a lower side. One end of a main handle and the other end of the same are connected to an upper portion of the main body front portion on the rear end side and an upper portion of the main body rear portion on the front end side. The main handle has a linear shape in parallel to a longitudinal direction of a cutting blade. In this configuration, the main handle is set in substantially parallel to the supporting portion, and a grip space is formed between the main handle and the supporting portion.

Abstract: An electrically powered garden tool includes an electric motor mounted upright within an outer shell housing, a pair of relatively reciprocating shear blades assembled to be driven by operation of the motor through a crank mechanism provided within a lower portion of the outer shell housing, and a cooling fan assembled to be driven by operation of the motor for introducing outside air into an upper portion of the outer shell housing to exhaust the introduced air from a lower portion of the outer shell housing. In the garden tool, a downward exhaust opening is formed within a lower end peripheral wall of the outer shell housing enclosing the crank mechanism such that the air spouted by rotation of the cooling fan blows out downward from the downward exhaust opening to restrain the occurrence of blowing noise of the air.

Abstract: A lubricated hair clipper drive system includes a clipper frame with a pair of opposed arms separated by a drive space, a drive shaft reciprocating laterally between the arms at high speed, a drive member receiving motive power from a power source and secured to the shaft for common reciprocation within the drive space, and a lubricant reservoir and applicator disposed on the shaft between the drive member and a corresponding one of the arms.

Abstract: A device for a motor driven tool such as a pole hedge trimmer, a pole saw or the like. The tool includes a drive unit that via a shaft tube is connected to a cutting unit. The cutting unit is turnably secured at the shaft tube by the device which is a turnable connection, wherein the cutting unit is movable between a range of at least two working positions and a transport position. The cutting unit is provided with one or several movable cutting elements and the tool is provided with locking structure for locking the movement of the cutting elements when the cutting unit is in the transport position.

Abstract: The invention provides a drive train for a hedge trimmer, the drive train being arranged, in use, to provide power to a downstream mechanism, the drive train comprising: a motor having an output shaft; a pinion coupled to the output shaft; a reduction gear arranged to be driven by the pinion, the reduction gear contained within a gear housing; a flywheel engageable to the output shaft, wherein the flywheel is arranged within the gear housing.

Abstract: The present invention may be used for vacuum hair collection for a hair clipper. A conduit may be positioned in the clipper and may have a nozzle positioned adjacent to a cutting blade a forward end of the clipper. The conduit may have a rear opening at a rear end of the clipper. There may be a constriction section formed in the conduit adjacent the nozzle. The conduit may have a nondecreasing cross sectional interior dimension from the constriction section to the rear opening.

Abstract: A razor and trimmer combination assembly includes an elongated handle, a razor blade, a trimmer and a motor. The razor blade is disposed at or adjacent a first end of the handle. The trimmer mounts on the handle and includes a moving blade. The motor drives the moving blade.

Abstract: A vegetation cutting device comprises, a housing, and a motor located within the housing. The motor comprises a rotating output shaft for driving a pair of reciprocating blades. The vegetation cutting device also comprises a rotatable front handle being rotatably mounted on the housing and is adapted to rotate with respect to the housing. The rotatable front handle comprises, a first trigger wherein the motor is operable on actuation of the first trigger. A release button is mechanical cooperation with the rotatable front handle for actuating rotation of the front handle. The vegetation cutting device also comprises an interlock mechanism mechanically coupling the release button and the first trigger wherein actuation of the release button prevents actuation of the first trigger and actuation of the first trigger prevents actuation of the release button.

Abstract: A blade head assembly for a hand-held hair cutting appliance includes a blade clamping device urging a cutting edge margin of a second blade in sliding engagement with a cutting edge margin of a first blade. The blade clamping device includes a clamping head operable for pivoting generally toward and generally away from the second blade about a pivot axis. The clamping head is resiliently biased generally toward the second cutting blade about the pivot axis into sliding engagement with the second blade. The second blade is slidable relative to the clamping head during reciprocating movement of the second blade relative to the first blade.

Abstract: The clipper lever support insert may be inserted into a clipper lever. A finger insert may have two approximately parallel sides formed from metal. The sides may be shaped to the approximate form of a drive finger side. A shaft end insert may have a plurality of sides approximately in the shape of a rectangular box formed from metal. The sides may be shaped to the approximate form of a motor end cavity side.

Abstract: A power tool has a drive motor and first and second tool members driven reciprocatingly by the drive motor in opposite directions, respectively. The first tool member is driven by a first connecting rod and the first connecting rod is connected to the first tool member by a first pivot joint arranged on the first connecting rod. The second tool member is driven by a second connecting rod and the second connecting rod is connected to the second tool member by a second pivot joint arranged on the second connecting rod. The first pivot joint is arranged on an end of the first connecting rod which end is facing the tool members. The second pivot joint is arranged on an end of the second connecting rod which end is facing away from the tool members.

Abstract: A hedge trimmer (1) comprises an electric motor (3) and at least two cutting blades (5,6), each blade comprising at least one row of teeth with the motor being connected to at least one of the blades so that rotation of the motor (4) produces a movement of at least one of the blades relative to the other, a first user operable switch (10) for operation of the hedge trimmer blades and a second user operable switch (11) which enables a user to select between at least two operating modes of the hedge trimmer, the two modes comprising a hedge trimming mode in which operation of the first user operable switch causes a reciprocal motion of the at least one blade, and a secateur mode in which operation of the switch causes a single cutting cycle to be performed. A two ratio gearbox may be provided to enable the blades to move at a lower speed and with higher torque when in the secateur mode compared with the hedge trimming mode.

Abstract: A handle assembly for a power tool is disclosed, in which the power tool has a housing, a motor provided in the housing, an output shaft adapted to be caused by the motor to execute reciprocating motion, and a blade assembly (5) extending from the housing along a first axis (A-A). The handle assembly (2) comprises a front handle (6), a rear handle (7) integral with the front handle (6) and a mounting portion adapted to be mounted to the housing of the tool, wherein the rear handle (7) is displaced from the plane (A-A) of the blade assembly (5) in use. As a result of this, the knuckles of the hand of the user that is gripping rear handle (7) are raised away from the surface of the object being cut. This provides the advantage that the user's knuckles avoid any grazing or cutting resulting from contact with the object, or with the ground when carrying out low cutting.

Abstract: An electric power tool (100) includes a power source (102) enclosed in a casing (104). The power source (102) is a brushless DC motor (202) which drives a drive mechanism (106) for a cutting device. Further, an oil pump is at least partly housed in the casing (104) of the electric power tool (100). The oil pump is also driven by the brushless DC motor (202).

Abstract: A handle assembly for a power tool is disclosed, in which the power tool has a housing, a motor provided in the housing, and an output shaft adapted to be caused by said motor to actuate a working member extending from the housing along a first axis (A-A). The handle assembly (102) comprises a front handle (106), a rear handle (107) integral with the front handle, and a mounting portion adapted to be mounted to the housing of the tool, wherein the front handle (106) forms an obtuse angle with the axis (A-A) of the working member in use. This last feature makes the power tool more comfortable for a user to operate, provided that the centre of mass of the power tool lies in the region between the front handle (106) and the rear handle (107). This will usually be the case, since the heaviest parts of the tool are generally the working member and the motor housing thereof.

Abstract: A motor cooling air flow deflector comprises a channel over at least one of the air flow outlet vents for electric motor cooling air from the periphery or circumference of a generally cylindrical housing of a clipper. The channel may be an inverted U-shaped structure having a span covering at least 120 degrees of the housing, and preferably more than 180 degrees. The inverted U-shaped structure is provided with a downwardly directed first end with a flared input and a second end with a vane for directing air flow out of the channel and backwardly along the housing of the clipper. The channel is adapted to conform to the variations in the generally cylindrical shape of the housing. The air flow deflector may be an attachment to an existing clipper or it may be fabricated or molded into the housing of a clipper.

Abstract: An electric hair trimmer includes a handle having a drive motor and a cutter head connected to the handle. The cutter head includes a housing having a pair of cutting blades extending from an end of the housing and disposed adjacent to one another. At least one of the blades is adapted for motion relative to the other blade to cut hair, and each of the blades has a curved shape at a terminal end.

Abstract: The invention relates to a motor-driven cutting device with a double blade arrangement driven by means of a double eccentric arrangement having opposing oscillating blade movement, comprising an advantageous construction with a separate double eccentric group for the drive device that can form a uniformly operable front-part group, particularly in conjunction with the double blade arrangement at a particularly favourable cost, and that is advantageous for installing the front-part group in the production process and/or when replacing the preferably uniformly operable front-part group.

Abstract: The invention relates to a cutting assembly (4) for a portable hand-held power driven working tool. The cutting assembly (4) comprises a first elongate cutting blade (9) and a second elongate cutting blade (10). The cutting blades (9, 10) are arranged to be connected to a gear, causing the cutting blades (9, 10) to move in a reciprocal manner along a longitudinal axis of the cutting blades (9, 10). The cutting blades (9, 10) are arranged to be mounted so that an interior surface (11) of the first cutting blade (9) faces towards and abuts on an interior surface (12) of the second cutting blade (10), wherein at least one of the cutting blades (9, 10) has a recess (13,14) extending in a longitudinal portion of the interior surface (11, 12) of the cutting blades (9, 10), such that a gap (15) appears between the cutting blades (9, 10) when they are mounted in a face-to-face relationship.