Abstract: A monofilament string trimmer line exhibiting reduced noise and reduced drag has a uniform oval cross section throughout its length. The monofilament line is spirally twisted about its longitudinal axis over at least a portion of its length to reduce noise production and drag.

Abstract: A trimmer head for a line trimmer includes an automatic line feeding mechanism. The trimmer head accepts a spool of cutting line and spins extended line to trim, for example, unwanted vegetation in lawns. Upon actuation of the automatic line feeding mechanism, damaged or broken cutting line is replaced with additional cutting line from the spool. The mechanism is actuated remotely (electrically or manually) and eliminates the requirement to bump the trimmer head on the ground thus reducing wear and tear on the trimmer.

Abstract: A cutting attachment for use with a vegetation cutting device. The cutting attachment has a body with a generally planar coupling portion and a central axis of rotation. In one embodiment, the body further includes a conical central wall portion extending radially outwardly and in a first direction from the coupling portion and the axis and a circular outer wall portion adjoining the central wall portion and extending generally radially outwardly therefrom. The central wall portion defines a conically-shaped self-cleaning inner cavity disposed symmetrically about the axis. The outer wall portion has a generally smooth outer surface which serves as a skid plate. An outer self-cleaning cavity is formed by an outer surface of the central wall portion and an inner surface of the outer wall portion. A coupling assembly, which can include an adapter having first and second clamping elements, is carried by the coupling portion for coupling the body to the cutting device to cause rotation about the axis.

Abstract: A rotary knife having a handle having a head section, a blade housing that comprises a split, ring-like member supported by the head section and defining a circumferentially extending groove, an annular blade supported in the blade housing groove for rotation about a central axis. The blade housing comprises a ring-like member having an annularly extending blade supporting groove that opens radially inwardly and in which the blade is rotatably disposed. The groove peripheral wall defines a plurality of blade engaging bearing faces spaced apart throughout the blade housing periphery and a plurality of circumferentially spaced apart fat receiving recesses. The blade housing also defines a plurality of fat directing channels each communicating with a fat receiving recess for directing fat from the recess out of the blade housing.

Abstract: A rotary cutter for a mower is provided wherein the cord delivering operation, which is necessary when the free end of the cord is worn, is carried out only when the rotary cutter is rotated at a low speed or is stopped. The rotary cutter includes a cord for cutting grass upon rotation thereof, a reel which holds the cord and allows delivering of the cord while the reel is intermittently rotated, a cover for a case which houses the reel, and a press body which protrudes downwardly from the case and is movable in an axial direction upon pressing so as to intermittently rotate the reel. A return spring for biasing the press body in a direction to protrude the press body from the case between the reel and the press body is also provided. The press body and the case engage each other such that the press body is slidable in an axial direction while preventing relative rotation with each other.

Abstract: A cutting blade for a motor-driven implement is provided. The cutting blade has a main body having a central fastening opening and blade sections that extend approximately radially from the main body. The blade sections have edges that extend in a radial direction and form cutting edges. Each blade section is provided with at least one bead-like embossment having a longitudinal axis that extends at an angle of between 0 and 45° relative to a longitudinal direction of the blade section.

Abstract: A head for a line trimming apparatus includes a body member and a detachable cover which may include a replaceable insert for connecting the head to a drive shaft of a line trimming apparatus. The body member includes opposed openings and a filament receiving channel for inserting an elongated flexible cutting filament into the head for retention thereon. A spring biased clamp is supported on the body member and is engageable with the filament portion residing in the channel to releasably retain the filament connected to the head. An actuator button projects through an opening in the body member and is operable to be pressed to cause the clamp to release forcible engagement with a filament so that the filament may be removed and replaced. In one embodiment the clamp and actuator are an integrally formed part and the filament projects through openings formed in spaced apart arms of the clamp member.

Abstract: A rotary device useful for trimming vegetation which automatically feeds two flail lines to establish and maintain two rotary flails.

Abstract: A trimmer head assembly of a string trimmer mower apparatus has a stack of plates with a ground engaging member on one end of the stack. At the other end, the stack of plates is fastened to a rotating shaft that is driven in rotation by the motor or engine of the trimmer/mower. The plates of the stack have line retaining devices to which one or more lengths of cutting line are secured. Each plate is of a sufficient thickness to spread the respective line retaining devices axially or vertically apart from one another in suitable increments for providing cutting height adjustment selectively by securing a cutting line at the appropriate height. The line retaining devices enable the cutting line to be secured without tools and without disassembly of the trimmer head. Further, the line does not need to be clamped in place to ensure that it remains secured during high speed rotation of the trimmer head.

Abstract: A cutter wheel for forming scribe lines on a brittle plate has a disk with two side planes. The disk has an edge formed at the outer periphery of the disk and a shaft hole formed at the center of the disk for inserting a rotational shaft. Further, at least one groove is formed to extend from a surface of one of the side planes along the shaft hole.

Abstract: A multi-purpose rotary cutting tool having a plurality of interchangeable head attachments, wherein the head attachments are easily attached and detached to a rotary cutting device, thereby providing various tools for a multitude of applications.

Abstract: A cutting head for a rotary flail retains a coil portion of a cutting line on a spool, and feeds a portion of an excess of the cutting line to the spool to adjust the coil portion and thereby restore a length of the distal portion of the cutting line to maintain a cutting circle of desired size. The distal portion of the cutting line is extended by locating the coil portion such that a centrifugal force arising from rotation of the distal portion overcomes a drag force on the coil portion to unwind a precise amount of the coil portion from the spool. A magazine stores the excess of the cutting line, disposed in a helical path defining a helix having an axis which generally coincides with the axis of the spool. The cutting head has no moving parts, high storage capacity and multiple independent automatic line capability.

Abstract: A multicomponent monofilament cutting line includes a first component material and a second component material, the same or different in chemical structure from the first component material and extruded separately from the first component material. The second component material provides the cutting line with cutting edges and has increased wear resistance properties and increased abrasion resistance properties compared to those same properties of the first component material. The monofilament cutting line for a rotary trimmer for cutting vegetation preferably includes a first component material having a specific gravity of about 1.15 g/cc or less; and a second component material having a specific gravity greater than 1.15 g/cc. Notably, the multi-component, monofilament cutting line itself has increased wear resistance and increased abrasion resistance as compared to a single component monofilament cutting line employing one of either the first or second component materials.

Abstract: A string trimmer head is provided for receiving and retaining separate lengths of string supplied from outside the head. String lengths passing through openings in the periphery of the head are held by clamping members provided within the head. The clamping members are selectively opened by activation of respective slidable members provided on the upper surface of the head in order to release short lengths of previously supplied string and/or to permit the receipt of new string lengths. On release of the slidable members, the respective clamping members move towards one another for clamping purposes under the influence of springs.

Abstract: An implement for cutting grass or weeds or the like wherein a Weedeater type cutting head is provided on which a cutting line or blade or the like cutting element is mounted for rapid whirling motion, wherein protective shielding is provided on the implement and interposed between the cutting element and the normal position of the operator, and a skirt-like mat of tough, resilient, flexible plastic filaments are provided on the implement for extending downwardly toward and preferably into contact with a terrain surface when the implement is in its operative posture, the filaments being sufficiently flexible to readily conform to the terrain surface when brought into contact therewith to thereby afford greatly enhanced protection against flying debris while providing substantially unhindered freedom of motion to the cutting head.

Abstract: A hedge trimmer assembly for trimming hedges and trees. The hedge trimmer assembly includes a head assembly comprising a rotatable trimmer head and a debris shield. A cutting line extending from the rotating head. A pole with the head assembly pivotably coupled to a first end of the pole. An adjustable head locking assembly for selectively locking the head assembly into a static position relative to the pole. A handle extending from the pole. A motor operationally coupled to the trimmer head. The motor is coupled to a second end of the pole. A trigger operationally coupled between the motor and the trimmer head.

Abstract: A manually guided implement having an air-cooled internal combustion engine for driving a tool is provided. The engine is disposed in a housing, with cooling air being conveyed by a fan wheel that is fixedly held on the crankshaft of the engine and that is accommodated in a cooling air spiral case that is open toward the engine. Formed in the housing is an air inlet via which ambient air can be drawn into the cooling air spiral case. A base of the spiral case is disposed between the fan wheel and the engine and is provided with a second cooling air inlet that provides communication between the interior of the housing and portions of the cooling air spiral case that convey cooling air.

Abstract: A gear head for a manually guided power implement is provided. Part of the tool shaft, which receives a rotatable cutting tool, is embodied as a cylindrical splined shaft having grooves for the positive transmission of torque to the cutting tool. An abutment plate is disposed on the tool shaft and has an abutment surface that extends essentially perpendicular to the longitudinal axis of the tool shaft. A centering cylinder extends through a circular central opening of the cutting tool and has inwardly directed longitudinal ribs that engage in the grooves of these splined shaft. A free end of the centering cylinder is provided with a beveled portion that extends from an outer contour of the cylinder to into the grooves.

Abstract: The spool impeller is a fully automatic cutting head for whirling filament vegetation trimmers, simpler, less expensive, and more reliable than the predecessors. Unlike the predecessors, the spool impeller does not waste filament. It consists of a single part, a small diameter spool attached to the drive shaft. The free end of filament coiled on the spool extends tangentially so that the tip traces a circle about the axis of rotation. In use, the coiled filament gradually unwinds to compensate for filament wear, maintaining a cutting swath of precisely constant size. There is no need for the operator to monitor the filament. Feeding new filament is controlled by the aerodynamic drag and centrifugal force acting directly on the extended filament. If the length of the extended filament is correct, drag and centrifugal force balance, and no unwinding or rewinding occurs. Too long, drag dominates over centrifugal force, rewinding the extended filament onto the spool just enough to restore the proper length.

Abstract: A vegetation trimming and edging device has an adjustable head that permits selective positioning between trimming and edging orientations. A shaft extends between the head and a handle. The head receives one end of the shaft. A coupling mechanism couples the head and shaft, and locks the head against rotational movement about the shaft. In particular, the coupling mechanism includes a locking structure and a bias mechanism. The bias mechanism urges the locking structure into engagement to prevent rotational movement of the head. Downward pressure applied to the head overcomes the bias, however, and disengages the locking mechanism for rotation of the head between trimming and edging modes. When the downward pressure is released, the locking mechanism is again engaged to lock the head in position for the desired operational mode.

Abstract: An edger blade assembly for cutting a beveled edge using a motorized edging machine. The edger blade assembly is a structure that includes a blade element. The blade element has two opposing free ends. Between the two free ends is a flat middle section, two diverging sections that extend outwardly from the flat middle section and two converging sections that extend between the diverging sections and the two free ends, respectively. The blade element is bent at an acute angle between the flat middle section and the diverging sections. The blade element is bent at an obtuse angle between the diverging sections and the converging sections, thereby forming a beveled blade structure from a single segment of steel.

Abstract: A trimming tool includes a selectable blade attachment for effecting a conversion between a string trimming mode and a blade trimming mode without requiring disassembly of the unit. The assembly includes a locking mechanism (46) selectively engageable with a pivoting trimming blade (40) that pivots between a retracted position and an extended position by centrifugal force. In one embodiment, the locking mechanism is reciprocated between the locked position and the unlocked position based on a rotation direction of the motor. The locking mechanism itself may also be reciprocated by centrifugal force. A spool lock, which is also positioned by centrifugal force, disables automatic string feeding in the blade trimming mode. The trimming tool may also be provided with a blower function incorporating a blower attachment readily attachable as a trimming guard of the trimming tool, or a blower assembly integrated into the tool components.

Abstract: A string trimmer head is provided for receiving and retaining separate lengths of string supplied from outside the head. String lengths passing through openings in the periphery of the head are held by clamping members provided within the head. The clamping members are selectively opened by activation of respective slidable members provided on the upper surface of the head in order to release short lengths of previously supplied string and/or to permit the receipt of new string lengths. On release of the slidable members, the respective clamping members move towards one another for clamping purposes under the influence of springs.

Abstract: The present invention relates to a saw blade and more particularly to a saw blade for cutting steel-reinforced structures to be used for cutting concrete, blocks or pipes in repairing or mending construction materials.

Abstract: A cutting head for a rotary flail retains a coil portion of a cutting line on a spool, and feeds a portion of an excess of the cutting line to the spool to adjust the coil portion and thereby restore a length of the distal portion of the cutting line to maintain a cutting circle of desired size. The distal portion of the cutting line is extended by locating the coil portion such that a centrifugal force arising from rotation of the distal portion overcomes a drag force on the coil portion to unwind a precise amount of the coil portion from the spool. A magazine stores the excess of the cutting line, disposed in a helical path defining a helix having an axis which generally coincides with the axis of the spool. The cutting head has no moving parts, high storage capacity and multiple independent automatic line capability.

Abstract: The invention is directed to a cutterhead for a portable handheld brushcutter for cutting grass, weeds and the like. The cutterhead includes a housing which holds a spool for the cutting filament. Two spool chambers are formed on the periphery of the spool by a radial partition wall. A cutting filament is wound in each of the spool chambers and each of the cutting filaments is assigned an exit opening in the housing which extends into free space. The partition wall lies at the same axial elevation with the exit openings. The partition wall is provided with at least one lead-in channel through which the filament is guided into the interior of the spool when inserted. A reliable introduction of the filament is provided by a simple configuration of the cutterhead and makes a reliable wind-up and pay-out of the filament possible. This is achieved by providing a lead-in channel for each spool chamber with the entrance of the lead-in channel being defined by an insert funnel.

Abstract: A portable lawn and brush trimmer including an elongated tubular boom arm, motor assembly mounted at one end of the boom, a trimmer head mounted on the opposite ends of the boom arm, and two adjustment mechanisms, which allow the attitude of the trimmer head to be adjusted about two different axis in relation to the boom arm is disclosed. The adjustment mechanisms allow an operator to manually change the attitude and orientation of the trimmer's cutting plane to conform to the slope and contour of the terrain without the operator altering the natural balanced operating position of the trimmer or his body posture while maintaining the natural balanced orientation of the boom arm with respect to the operator and not the terrain being worked. One adjustment mechanism (pivot adjustment) allows the trimmer head to pivot in relationship to the boom arm between a number of manually selectable angular positions.

Abstract: This method, offering quiet, pollution-free cutting, consists in emitting at least one pressurized jet of water which is directed at and moved over the vegetation to be cut, the pressurized jet or jets of water being themselves the cause, by mechanical reaction, of their movement, in particular their rotary movement. The cutting device that puts this method into effect comprises means for supplying water at pressure, and a rotating head provided at its periphery with at least one nozzle through which a cutting jet of water is ejected, the jet or jets of water generating, by reaction, rotation of the head and therefore of the jet or jets themselves. This device may be in the form of a portable appliance.

Abstract: A flail head for a vegetation cutter having face-to-face cup shaped central body portions separated by a predetermined distance Symmetrically spaced pivot posts extend between the face-to-face central body portions. A fail blade is pivotably attached to each pivot post. In one embodiment of the flail head, the face-to-face body portions are identical and the pivot posts are formed by mating semi-cylindrical posts formed integrally with each of the central body portions. The flail blades and body portions are made from different plastic materials to prevent the fusion or welding of the flail blades to the posts.

Abstract: A vegetation cutter, a cutting string for use with a vegetation cutter, and a method of cutting vegetation, are provided which utilize a novel cutting string arrangement in which a twist and living hinge are provided in a cutting string having a drag co-efficient of less than 1.0, typically with a first long axis and a second short axis, the second axis less than 85% of the first axis. The twist is provided between the free end of the string and where the string is mounted to the head, or where two twists are provided in the string, the string is mounted to the head at a central portion between the twists. The string may be mounted to the head by grooves or slots and/or clamping mechanisms, or a wide variety of other components. The cutting string may have a wide variety of cross-sectional configurations (both symmetrical, such as elliptical, or non-symmetrical, such as substantially tear drop). The twist is typically between about 30-150°, most desirably about 90°.

Abstract: A cutting blade cover for a brush cutter comprises a central portion 50, a first blade accommodating portion 28, a second blade accommodating portion 29, and a third blade accommodating portion 30. The first, second, and third blade accommodating portions 28, 29, 30 are provided radially from the central portion 50. The first blade accommodating portion 28 includes a first concave portion 31. The second blade accommodating portion 29 includes a second concave portion 36. The third blade accommodating portion 30 includes a third concave portion 40. The first concave portion 31 has an inner shape conforming to an outer shape of the first blade 17 to cover an outer periphery of the first blade 17. The second concave portion 36 has an inner shape conforming to an outer shape of the second blade 18 to cover an outer periphery of the second blade 18. The third concave portion 40 has an inner shape conforming to an outer shape of the third blade 19 to cover an outer periphery of the third blade 19.

Abstract: Multiple embodiments of a string trimmer debris shield are disclosed. In one embodiment, an L-shaped bracket having a clamp at one end is fitted to a string trimmer so that the bracket may be located to either side of a string head of the trimmer and either above or below a mounting point of the bracket. The bracket is mounted to the shaft near the rotating string, and supports a debris shield between a side of the string head from which debris is shown and legs and feet of a user. In another embodiment the bracket extends horizontally straight from the shaft to either side of the trimmer, and supports a debris shield. In a third embodiment the bracket is mounted to a shaft of a string trimmer and supports a perpendicular debris shield support member which in turn supports a debris shield on a side of the string head from which debris is thrown toward the user. In this embodiment, the debris shield may be rotated about the shaft to either side of the trimmer.

Abstract: A vegetation cutting implement includes a rotatable support head which mounts a hub having a plurality of cutter elements comprising self-supporting struts. Each strut is more than 50% non-metallic material (typically more than 90% plastic or rubber), and the hub is readily replaceable in the vegetation cutting implement merely by detaching a fastener. Typically the cutter elements are integral with the hub, although a number of radially extending openings may be provided through which individually replaceable cutter elements pass. The self-supporting struts each preferably comprise a beam-like structure with a first axis which is the strongest axis and has a highest moment of inertia and a second, weaker axis, and the head is rotated so that the first axis of the beam-like structure of each strut is positively maintained and moves in a predetermined cutting plane which is generally transverse to a portion of vegetation to be cut.

Abstract: The head comprises two covers (3, 5) connected together and an intermediate ring (7), these defining a volume for containing at least one cutting cord (F). The intermediate ring (7) comprises spring means (7A, 7B, 7C) that lock said intermediate ring (7) angularly to at least one of said covers in such a way as to prevent relative rotation between the intermediate ring and the cover in the direction in which the ring tends to be rotated by the resistive force (F.sub.t) acting on the portions of cutting cord projecting from the head (1) during the rotation of the latter; at the same time the spring means permit relative rotation in the opposite direction by torsionally releasing the intermediate ring from said cover, by the action of the traction exerted on said projecting ends of the cutting cords (F).

Abstract: An elongated flexible cutting string, or substantially self-supporting strut cutting element, is connectable to a rotating device for use in a method of cutting vegetation. The cutting string has numerous advantages over conventional cutting strings, having a drag coefficient which is at least about 5% (e.g. 10-300%) less than the drag coefficient of a string having a substantially round and smooth cross-section. The drag coefficient of aerodynamic line 10 is 1.0 or less, e.g. about 0.35 or less. The cross-sectional configuration preferably simulates a tear drop (with or without an extension nose), and can have a textured (e.g. with golf ball simulating dimples, saw toothed or a wavy configuration) exterior surface. The pitch of the line is positively maintained while it is rotated in a cutting plane, e.g. controlled with an eyelet and/or a compound taper. Other cross-sectional configurations are an ellipse of at least 1.

Abstract: The present invention is a one-piece fixed line vegetation cutting head with several advantages. It is easily adaptable to virtually any vegetation trimmer and it will accommodate a variety of types and gauges of both cutting filament line and wire. The preferred embodiment has an upper portion with the shape of an inverted truncated cone which gives the head an advantage in deep vegetation by hindering the advance and entanglement of long pieces of vegetation around the vegetation trimmer's drive shaft. The preferred embodiment also has a disc-shaped lower portion with two pairs of cutting filament line passage holes in opposed positions near the circumference of the disc which are oriented at oblique angles to both the diameter and the central bore of the disc. When a discrete length of cutting filament line is inserted through the adjacent passage holes in each pair, it is subjected to less bending and wear during high speed rotation than would be experienced with the use of non-angular passage holes.

Abstract: A line trimmer head (10) includes a line feed configuration which facilitates reloading the head (10) with new line without requiring removal of the spool (24) from the housing. Line (18) is sequentially fed first into the housing through a peripheral opening (20) in the housing, through a guide channel (84, 86) in the spool, and then out of the housing beyond a lower flange (26) of the spool through an opening in the hub (98) of the spool. Finally, the line is fed into a small opening in a spool flange (94) to secure the line with respect to the spool. Rotation of the spool then 46 causes the line to be drawn into the housing through the peripheral opening and wrapped around the spool. The spool provides separate storage compartments (38, 40) for different lines. Additional payout of line is provided when a bump knob is bumped on the ground surface.

Abstract: A cutting attachment for use with a vegetation cutting device. The cutting attachment has a body with a generally planar coupling portion and a central axis of rotation. In one embodiment, the body further includes a conical central wall portion extending radially outwardly and in a first direction from the coupling portion and the axis and a circular outer wall portion adjoining the central wall portion and extending generally radially outwardly therefrom. The central wall portion defines a conically-shaped self-cleaning inner cavity disposed symmetrically about the axis. The outer wall portion has a generally smooth outer surface which serves as a skid plate. An outer self-cleaning cavity is formed by an outer surface of the central wall portion and an inner surface of the outer wall portion. A coupling assembly, which can include an adapter having first and second clamping elements, is carried by the coupling portion for coupling the body to the cutting device to cause rotation about the axis.

Abstract: A self-powered device for cutting foliage that includes a backpack portion, a foliage cutting portion, and a coupling portion. The backpack portion includes a frame, a gas engine, and a flexible shaft. The coupling portion includes a power portion and a tool portion. The power portion includes a collar that is crimped on the sheathing of the flexible shaft of the backpack portion and a stop that extends fixedly and axially from the collar of the power portion. The tool portion includes a collar that is crimped on the casing of the flexible drive shaft of the foliage cutting portion with the end thereof having a blind bore extending axially therethrough which fixedly receives the end of the flexible shaft of the backpack portion. The collar of the tool portion has an inner periphery that fixedly receives the stop of the power portion.

Abstract: The present invention is directed to a rotatable cutting head for a powered trimmer comprising top and bottom cover members, the bottom member is adapted to be operably associated with the drive shaft of a trimmer and includes at least one pivot member for receiving a pivoting cutting element, a latch mechanism is provided on the top cover for engaging the pivot member when the top and bottom cover members are mated, the latch member is secured against the pivot member by centrifugal forces acting on the latch during operation of the trimmer. The cutting elements comprise blades or molded lines that are readily adapted to be interchanged within the cutting head without the need for tools or complex disassembly.

Abstract: A line trimmer head assembly having a central hub and a body including an annular disc extending circumferentially radially outward from the central hub to removably receive the length of a uniform cross-section line. The disc member is provided with a pair of openings on the disc periphery through which a fixed line length is threaded. The interior portion of the disc is provided with at least two retainer clips having a hook shaped member with an incline ramp surface for cooperating with the portion of the line extending between the two openings. The line is held in place by tension which causes the line to travel down the ramp surface.

Abstract: A cutting assembly adapted for use in line trimmers that employ either a spooled filament or a fixed filament. The cutting assembly comprises a cutting filament consisting of a stainless steel filament coated with a polymeric elastomer, steel tube-type collar stops, and allen head set screws. The cutting performance and capabilities of commercially available vegetation trimmers can be substantially improved by replacing their cutting assembly with the instant cutting assembly. The cutting filament does not have a point of attachment within the rotating housing hub located on the bottom of the trimmer, thereby enabling the cutting filament to better follow the rotation of the hub, and thereby improve the overall cutting ability of the trimmer.

Abstract: An apparatus and method for forming a string trimmer head assembly is disclosed. The head assembly includes a head and one or more flails. Each flail includes at least one deformed portion and at least one undeformed portion and the head includes a flail holding portion adapted to mate with the deformed portion for securing the flail to the head.

Abstract: The trimmer is adapted to trim the grass on the vertical or near vertical edges of a lawn bordering a garden. The trimmer incorporates conventional motor driven rotating blade or filament cutting element(s) at the lower end of an elongated handle assembly. There is a shroud around the cutting element(s). The handle assembly is configured such that the open side of the shroud faces the lawn and user when the trimmer is in use, allowing the user to stand and move on the lawn. The lower portion of the shroud contacts the surface of the garden and the edge of the shroud contacts the edge of the lawn to facilitate proper positioning of the trimmer in use. The handle assembly may be configured such that the handle itself is on the opposite side of the plane of the cutting element(s) from the lower end of the shank of the handle at its attachment to the shroud.

Abstract: A cutter wheel which can form a deep slit on an article to be cut so that the article can be broken easily along the slit and a perpendicular cut surface can be formed reliably when the article is broken along the slit. The cutter wheel is a disk-shaped member having a cutting edge along the outer edge and formed with a mounting hole extending therethrough along its axis. The mounting hole has an irregular shape so that the cutter wheel vibrates when it rolls due to steps between adjacent sides of the polygonal hole. The edge of the wheel can thus penetrate more deeply into the glass plate so that a deeper and smoother slit can be formed in the glass plate. This in turn makes it possible to more easily break the glass plate along the slit and to form a perpendicular cut surface.

Abstract: A braking device of a portable trimmer according the present invention comprises a cylindrical brake drum portion provided around a cutter blade retainer, an anti-rotation device, and a brake shoe provided inwardly of the brake drum portion and supported by a support shaft. The brake shoe extends along an inner surface of the brake drum portion so that the distance between the support shaft and the line tangent to the middle portion of the brake shoe exceeds the radius of the inner wall surface of the brake drum portion. An anti-rotation device is installed in a vacant space within a gear case and inwardly of the brake drum portion.

Abstract: The present invention is a blade which is designed and configured to be utilized with conventional edging devices. The blade of the present invention is substantially U-shaped and includes a top planar wall having opposite ends. Extending outward from each end is a rectangular shaped end portion. When in use, the outer walls of the end portions will contact the ground. This will offer the user a device which is versatile and powerful. For protecting the user, a cover is provided.

Abstract: This cutting line intended to trim and cut vegetation can be used in rotary-head implements such as brush cutters and edge trimmers. The cutting line consists of a core made of biodegradable and/or photodegradable substance which is covered with a coating or "skin" made of a synthetic substance such as polyamide or polyurethane, forming the exterior surface of the line. Such a line can thus be broken down more rapidly after use, while at the same time retaining excellent mechanical qualities while it is being used.

Abstract: An adjustable height cutting head for a string trimmer machine provides for the positive locking in place of the cutting string or line holder portion of the device, relative to a cylindrical central core which secures conventionally to the machine. The central core includes a series of adjustment holes of different heights through the wall thereof, with the collar of the line holder having a series of holes corresponding to any one of the heights of the adjustment holes in the central core. The height of the line holder disc is quickly and easily positively locked in place at the desired height relative to the central core, by securing a few bolts in the desired position. The present system precludes slippage of the line holder portion relative to the core, and moreover distributes the cutting lines evenly about the periphery of the line holder disc for proper balance of the assembly to preclude vibration and fatigue of the machine and operator.

Abstract: A line for a rotating trimmer has a plurality of longitudinal outwardly-extending cutting edges, spaced circumferentially about the main body portion of the line. A cross-sectional area of the main body portion is selected to be between 70 percent and 90 percent of the area of the space circumscribing the cutting edges to provide substantial bulk to the line to increase its wear, while retaining the advantages of the cutting edges for facilitating cutting of grass and the like.