Abstract:
An anti-winding assembly reduces or prevents debris from winding on a trimmer and/or makes them easier to remove. The trimmer includes a trimmer head mounted to a rotatable arbor and supporting one or more cutting lines. The anti-winding assembly includes a collar positionable between the trimmer head and an adjacent trimmer component, and a shield positioned radially outward of the collar. The shield covers gaps between the collar and the trimmer head and between the collar and the adjacent trimmer component. The assembly reduces exposure to pinching gaps and to powered rotating parts that enable tight windings that can accumulate to lock trimmer rotation.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation-in-part (CIP) of U.S. patent application Ser. No. 14/955,196, filed Dec. 1, 2015, pending, which claims the benefit of U.S. Provisional Patent Application No. 62/085,983, filed Dec. 1, 2014, the entire contents of each of which are hereby incorporated by reference in this application. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     (NOT APPLICABLE) 
     BACKGROUND OF THE INVENTION 
     The invention relates to flexible line trimmers and brush cutters and, more particularly, to an anti-wind/wrapping assembly that prevents trimmed debris from winding on a trimmer. 
     One of the most irritating experiences when cutting into higher or taller vegetation with a common flexible line trimmer or brush cutter is the wrapping of long strands of vegetation around the axis of rotation of the rotating head. It also applies to vines, or previously cut vegetation lying on the ground. Additionally, it is not uncommon to run into invisible monofilament fishing line, often left along lake banks and streams that rapidly and very effectively snarls a trimmer head into a stalled rotation. As these strands become entangled within the trimmer head&#39;s openings and crevices, the debris winds with rotation, and accumulates into a massive bundle to then fill the open volume, and to reach adjacent stationary structure of the trimmer body. The wrappings rapidly bind and stall the rotating head from turning. During the binding process, unless the operator fails to shut down the rotation by releasing the trigger, heat builds up on the rotating or even the stationary parts to cause melting and structural damage to the components, thus often destroying the system. 
     When severed at their base, long vegetation cuttings (strands) drop onto the rotating parts below, and then are carried along with the rotation. They wind into a bundle under power, like a bobbin winds thread onto a spool. There are numerous scenarios regarding how the debris can be presented to the trimmer head areas. One end of the long debris pinches or binds onto the rotating shaft, or its direct attachment, which is under power from the driving motor. The continued powering and tightening of the strands forcefully wind and wrap the debris around and/or between each other to accumulate, and to become tighter and tighter. The accumulating snarl continues to rotate until it hits an obstruction (the connecting housings and components in the area) to then bind the entire system from turning. 
     The degree of bind can vary, but there will more likely be heavy vibration forces due to the imbalance of the wrapped mass to create further trimmer damage. Certainly, vibratory forces become risky to the operator who is trying to control the system which is now way out of balance. When combining the problematic imbalance with heat accumulation, it further results in more undesirable and destructive forces as well as melting damage to plastic or non-metallic components. 
     In all cases, the operator must inconveniently stop working by shutting down the trimmer to physically remove the compacted snarl of strands from the exposed rotating parts.  FIG. 1  shows an exemplary trimmer with trimmed debris being wound into the space between the trimmer head and a gear box housing.  FIGS. 2-4  show an exemplary trimmer including a glider disk, with trimmed debris being wound into the space between the trimmer head and the glider disk. Most times, the wrappings are so tightly compressed they cannot be removed by hand, nor can the snarl be removed even with needle-nose pliers. As a result of this locked and snarled system, the operator may use a sharp cutting knife to cut through the tightened snarl. Often it may be best to remove the bound debris from the trimmer with a full disassembly of the head components from the trimmer. This is a common nuisance and severe weakness of the trimmer or brush cutter. 
     As a preventive method (when possible), users are often advised to cut long and tall vegetation from the top down to achieve shorter segments that are less likely to wrap. This produces shorter strands that are less likely to wrap and accumulate. 
     While this hand-supported trimmer procedure may be helpful, it is counter to the purpose of a trimmer machine (especially with flexible line blade cutters) that may be ground supported, or more intended to cut lengthy or tall vegetation close to the ground. Therefore, while nuisance winding is a severe problem when it occurs above the head, there is an added need to prevent or reduce winding when using a ground supported trimmer glider system that utilizes a lower end ‘free-wheeling’ disc to be less vulnerable to the problems of accumulated windings that would likely occur above the head, or below the head (between the glider and the head). An exemplary glider system is described in copending U.S. patent application Ser. No. 14/280,916, the contents of which are hereby incorporated by reference. 
     Some trimmers may be equipped with a thin metal spacer plate compressed between the head and the upper geometry structure, which turns with the head under full power. While it may reduce the pinching gaps where the long debris can pinch, it remains under full power to wind fibrous debris into a tightly bound bundle. This plate is also part of a system design that reduces the ‘fill volume’ above the head where the snarled bundle would fill. Reducing the volume directly above the head and reducing the pinch points are beneficial, but only reduce some of the accumulation probability because once a strand begins to pinch, it will wind debris by the components under power into a tightened snarl. 
     The glider (a free-wheeling disc mounted below the head) enables a trimmer to be ground supported (below the cutting plane). It is also more susceptible to winding and wrapping as it promotes resting the trimmer on the ground to effectively ‘rotary mow’ with a flexible series of line blades. This new method of using a trimmer encourages cutting long and tall vegetation at the base and close to the ground. Therefore, the new method becomes even more vulnerable for debris to then drop down directly onto the rotating head and glider mechanisms to then wrap and bind at either the location above the head or below the head between the head and the glider. Therefore, a ground supported trimmer can be expected to have more exposure to wrapping potentials than a hand-supported trimmer. More likely, a handheld trimmer would not be cutting as low to the ground as frequently as would be a glider system. 
     While further analyzing the accumulation volume between the head and glider plate, there is a diminishing opening or pocket from outside in toward the center of the glider rotation. This volume is subject to the accumulation of dropping strands making it even more vulnerable to accumulate the undesirable debris. 
     BRIEF SUMMARY OF THE INVENTION 
     It has been discovered that winding and wrapping can be substantially mitigated by shielding the gaps that pinch the debris and by isolating the power sources of rotation that create the winding. The device of the preferred embodiments utilizes a roller, ball or sleeve bearing or the like or a simple collar that separates or isolates the rotating head from a strand or bundle of accumulated debris. The collar or the outer race or outer surface of the bearing is free to rotate, and power to the strand is thus disconnected, therefore enabling the strand of vegetation or debris to remain in a more static condition. The free floating collar is preferably made from lightweight material of low friction. It slides at a speed much lower than the rotating parts along the rotating surfaces with limited heat buildup. Gravity allows the collar to drop onto the rotating head below and to remain in a free-floating position. Further, it is confined by internal flange and radial clearances not to be able to transmit power. Even if some winding were to occur, the winding is prevented from being wound tightly enabling easy removal. A shield associated with the bearing or collar further serves to minimize or reduce exposure to pinching gaps between the bearing/collar and the trimmer head as well as between the bearing/collar and adjacent trimmer components. The shield may also serve as a locating guide for the application of the collar without bearings. Essentially, the shield minimizes the direct horizontal entry of fibrous matter into the likely pinching gaps that are also under rotational power. The shield may be positioned inward or outward but is more preferably positioned on the outward side of a gap containing a power winding exposure. 
     In an exemplary embodiment, an anti-winding assembly for a trimmer includes a collar positionable between the trimmer head and an adjacent trimmer component, and a shield positioned adjacent the collar. The shield covers gaps, possibly both radial and axial, between the collar and the trimmer head and between the collar and the adjacent trimmer component. The shield may be a guide that contains a position of the collar. The collar may be free floating with a clearance (radial and/or axial clearance) between the trimmer head and the adjacent trimmer component. The collar may include a bearing with a freely rotating outer race and an inner race connectable to the rotatable arbor, where the outer race may be rotatable relative to the inner race. The shield may be integral with a trimmer head cover. In this context, the shield may include a first ring integral with the trimmer head cover and a second ring integral with the adjacent trimmer component. The trimmer component may include a glider disk rotatably mounted to a distal end of the trimmer head. The anti-winding assembly may also include a plurality of collars stacked between the trimmer head and the glider disk, where the plurality of collars act as spacers to adjust a trimming height. 
     In another exemplary embodiment, a trimmer includes a rotating trimmer head; at least one cutting line coupled with the trimmer head; a trimmer component disposed adjacent the trimmer head; and the anti-winding assembly that prevents debris from winding between the trimmer head and the trimmer component. 
     In yet another exemplary embodiment, a trimmer includes a motor driven rotating trimmer head; at least one cutting line coupled with the trimmer head; a glider disk disposed on a ground side of the trimmer head; and a first anti-winding assembly positioned between the trimmer head and the glider disk. The first anti-winding assembly includes a first collar positioned between the trimmer head and the glider disk. The assembly may also include a first shield covering gaps between the first collar and the trimmer head and between the first collar and the glider disk. The first collar may be integral with the glider disk. The first shield may define a first collar guide channel in which the first collar is disposed. The trimmer may additionally include a stationary drive box housing disposed on a handle side of the trimmer head, and a second anti-winding assembly positioned between the trimmer head and the drive box housing. The second anti-winding assembly includes a second collar positioned between the trimmer head and the drive box housing. The second anti-winding assembly may also include a second shield covering gaps between the second collar and the trimmer head and between the second collar and the gear box housing. The second shield may define a second collar guide channel in which the second collar is disposed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other aspects and advantages will be described in detail with reference to the accompanying drawings, in which: 
         FIGS. 1-4  illustrate a problem that occurs with rotating trimmers; 
         FIGS. 5-5B  show the anti-winding assembly with an exemplary trimmer application having a glider disk; 
         FIGS. 6 and 7  show the use of the anti-winding assembly for adjusting a trimming height with the glider disk; 
         FIGS. 8-8B  show the anti-winding assembly between the trimming head and a gearbox housing; 
         FIGS. 9-16A  illustrate alternative embodiments of the anti-winding assembly; 
         FIGS. 17 and 18  show exemplary bearings for use with the anti-winding assembly of the described embodiments; 
         FIG. 19  illustrates an exemplary application of the anti-winding assembly to a trimmer including a flat motor; 
         FIGS. 20-22A  show a slightly modified version of the anti-winding assembly; 
         FIGS. 23 and 23A  show the slightly modified version with the collar positioned between the trimming head and a gearbox housing or flat motor; and 
         FIGS. 24A and 24B  show more simplified alternative free-wheeling and contained collars. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIGS. 5-7 , a first exemplary application of the anti-winding assembly will be described in conjunction with a trimmer that incorporates a glider disk such as the glider disk described in the noted co-pending U.S. patent application. A trimmer head  10  is typically secured to a rotatable arbor (not shown in  FIG. 5 ) and supports one or more cutting lines  12 . The cutting lines  12  shown in the figures are exemplary molded lines with aerodynamic cross-sections available from Aero-Flex Technologies of Rock Hill, S.C. The cutting lines may also be common monofilament cutting line. 
     The glider disk  14  is attached to the trimmer head  10  via a bolt  16  or the like through a glider bearing  18 . The anti-winding assembly  20  is positioned in the gap between the glider disk  14  and the trimmer head  10 . 
     The anti-winding assembly  20  includes a bearing  22  positionable between the trimmer head  10  and the glider disk  14 . The bearing includes a freely rotating outer race  24  and an inner race  26  connected to the rotating arbor. A bearing member  28  such as a ball, needle or sleeve bearing member is disposed between the freely rotating outer race  24  and the inner race  26 . The anti-winding assembly  20  also includes one or more shields or ledges  30  positioned radially outward of the bearing  22  adjacent the outer race  24 . The shields  30  cover gaps  32  between the bearing  22  and the bottom of the trimmer head  10  and between the bearing  22  and the glider plate  14 . In the embodiment shown in  FIGS. 5-7 , the shield  30  may be integral with a head cover  34  of the trimmer head  10 . The shield may also be integral with the glider disk  14 . As shown, the shield  30  forms part of the bracket of the glider disk  14  that secures the glider disk  14  to the glider bearing  18 . The shields  30  may form a first ring integral with the trimmer head cover  34  and a second ring integral with the glider disk  14 . 
       FIGS. 6 and 7  show the use of multiple bearings  22  stacked between the trimmer head  10  and the glider disk  14 . The bearings  22  act as spacers to adjust a trimming height of the trimmer. That is, in use, the glider disk is intended to engage the ground to support the trimmer during a trimming operation. The bearings  22  serve to increase the space between the glider disk  14  and the trimmer head  10 , thereby increasing a cutting height in the glider disk application. 
       FIGS. 8-8B  show an application of the anti-winding assembly in the space above the trimmer head  10  or between the trimmer head  10  and an upper component  36  such as an arbor gear box housing, a motor housing, a direct drive gear box housing, etc. As shown in  FIGS. 8A and 8B , a shield plate  38  may be secured to the gear box housing  36 , and the bearing  22  is interposed between the shield plate  38  and a top cover  40  of the trimmer head  10 . The shield or circular ledge  30  may be formed integral with the shield plate  38  and the top cover  40  as shown in  FIG. 8B . The shields  30  are positioned adjacent the gap  32  between the bearing and the shield cover plate  38  and between the bearing and the top cover  40  of the trimmer head. 
       FIGS. 9-16A  show variations on an embodiment with the shield  30  cooperating with a shield member  42  such as a slip ring or the like that is cooperatively engaged with the gear box housing  36  in various configurations. The shield member  42  may be secured to the outer race of the bearing  22  for free rotation with the outer race. The components can be assembled by sliding a locking washer  52  onto an arbor spline  48 , followed by the combined shield member  42  and bearing  22 . The top cover  40  of the trimmer head  10  is then secured to the arbor threads with fasteners such as a nut pocket  44  or a knurled threaded insert  46 , which compress the subject parts into a rigid metal-to-metal assembly to assure a solid system without compression and to assure the surrounding parts resist collapse to interfere with the freewheeling operation of the shield member  42 .  FIGS. 9, 13 and 13A  show the shield member  42  engaged with the gear box housing  36  in a butt joint with ends of the gear box housing. With reference to  FIG. 13A , the arbor spline  48  and the locking washer  52  are used in conjunction with an inserting pin through a pin slot  60  to lock to hold the locking washer  52  and arbor shaft from turning while installing or removing the head to or from the arbor shaft threads.  FIG. 12  also shows a locking pin hole  60 . To assemble a brush cutter blade, the locking washer  52  is also used to assemble and pilot the metal blade at its central and to clamp the blade in concert with an outboard washer and nut. This heavy washer  52  rotates and is under power, and is thus a potential ‘strand power winder’ that should also be shielded by the shield member  42  or slip ring. Naturally, different manufacturers have differently designed and fitting splined locking washers. 
       FIGS. 10, 12 and 12A  show the shield member  42  engaging an outside surface of the gear box housing  36 , overlapping ends of the gear box housing  36 .  FIGS. 11, 14 and 14A  show the shield member  42  engaging an inside surface of the gear box housing  36  with ends of the gear box housing overlapping the shield member  42 .  FIGS. 15 and 15A  show the shield member  42  and a nut pocket  44 , and  FIGS. 16 and 16A  show the shield member  42  and a knurled threaded insert  46 . 
     The shield member  42  in the form of a slip ring or the like may also be utilized with the glider system with minor modifications to the glider system design. For example, the glider system may incorporate shields or circular ledges on the cap and the glider, and a slip ring extension could be added to the outer race of the bearing in a similar way as the top system. 
       FIG. 15  references use of differently fitting and designed slip ring anti-wind systems that can be adapted to current trimmer models now on the market that include a nut pocket that enables a different nut to fit differently threaded arbors. This would be for an after-market product. There may be a plastic compression joint subject to plastic creep that requires a flat washer  54  and self-tightening threads. This is the only deviation from a metal to metal compression through the inner race connections. 
       FIG. 16  uses a metal spacer tube  56  as an inner race to allow use of a bushing  58  (in the diagram shown, a split flanged bushing) that rides and floats on the metal spacer  56  and metal washer  54  as bearing surfaces. This isolates an outer slip washer to be freewheeling. The design may utilize a nut pocket or a molded insert with a thread selected to fit a matching threaded arbor. This system, with the metal sleeve completes the metal to metal compression joint as a system, or if a nut pocket is used, the  FIG. 15  design may be incorporated. 
       FIGS. 17 and 18  show exemplary bearings  22  for use with the anti-winding assembly of the described embodiments.  FIG. 17  shows an exemplary flange bushing, and  FIG. 18  shows an exemplary roller bearing.  FIG. 17  is a split bushing system that rides on a metal spacer that acts as an inner bearing race. The outer shell extension donut houses the bushings and together form the slip ring.  FIG. 18  incorporates an assembly of a ball bearing and outer donut shell to form a slip ring. The bearing can be pressed in or molded in. 
       FIG. 19  illustrates an exemplary application of the anti-winding assembly to a trimmer including a flat motor  62 . 
       FIGS. 20-23A  show a slightly modified variation of the anti-winding assembly. In this variation, the bearing from the first embodiment is replaced with a collar  22 ′ that is free-floating with a clearance between powered and unpowered surfaces, such as between the trimmer head  10  and an adjacent trimmer component (e.g., glider disk  14 ). The collar  22 ′ is essentially a simple ring formed from a low mass plastic. Compared to the construction of the first embodiment, the collar  22 ′ is simpler and less costly. Preferably, the collar  22 ′ is manufactured by injection molding, extruded, cut-off, then finished with conventional manufacturing means. The low mass plastic of the collar  22 ′ operates with low friction between the powered or unpowered components and is designed to float freely. 
     In this embodiment, the shields  30 ′ define respective guide channels  31  in which the collar  22 ′ is disposed. The collar  22 ′ is thus captivated or maintained in position by the channel  31  defined by the shield  30 ′. As shown, the shield  30 ′ may be configured as concentric rings integral with the trimmer head cover and/or the trimmer component to define the collar channel  31 . 
     Like the first embodiment, the shield  30 ′ and collar  22 ′ minimize gaps where loose vegetation strands could enter. The components overlap to prevent strands from entering gaps in the various potential directions, i.e., radially or axially. The collar  22 ′ is not subject to compressive forces clamping it together; rather, the collar  22 ′ floats within a captivated geometry of adjacent components. 
       FIG. 22A  illustrates an alternative constructions with the collar  22 ′ integrated with the glider disk  14 . The integrated collar  22 ′ can be positioned at any desired radius within the glider disk profile. 
     The loose collar allows better and more simplified reach with more finger clearance to readily reach and remove unbound accumulation of strands that accumulate without being power bound. 
       FIG. 23  illustrates an exemplary application of the anti-winding assembly including the collar  22 ′ in conjunction with either a gearbox  36  or a flat motor  62 .  FIG. 23A  shows the collar  22 ′ including a ledge  23  supported on the trimmer head  10 .  FIGS. 24A and 24B  show more simplified alternative free-wheeling and contained collars  22 ″ with excess radial and axial gaps and with controlled axial positioning from both upper and lower face contact. This allows a containment of the collar  22 ″ between both rotating and stationary components. Sufficiently sized radial and axial gaps to allow loose material to self-discharge or evacuate. The collar  22 ″ in  FIG. 24A  is inserted between a gear box housing  36  and the trimmer head  10 . The collar  22 ″ is secured within the assembly. As shown, the collar  22 ″ may be provided with a ledge  23  that extends into the space between the gear box housing  36  and the trimmer head  10 .  FIG. 24B  shows a variation with the collar  22 ″ including a shoulder  23 ′ secured to the gear box  36 . In some embodiments, the collars  22 ″ could be molded or formed with a lightweight, lower friction material such as a Delrin® plastic, or formed (e.g., by stamping and drawn) from a lightweight thin metal (steel, aluminum, etc.). The collars  22 ″ are designed to float axially within a gap of 0.030″ to 0.250″. The collars  22 ″ are installed between the gear box and the rotating head by inserting the collar onto the gearbox, and then installing and tightening the head to the arbor. 
     In the described embodiments, variations of the anti-wind system include a first anti-wind system preferably disposed on top of the head between the stationary arbor gearbox/motor housings and the rotating head. The first system uses a slip ring assembly as a shield that shields pinching gaps while isolating power that could transfer to the strands. Circular ledges may be used on the upper arbor gearbox/motor housings, and on the head as shown in  FIGS. 9-11 . A second anti-wind system is preferably disposed between the rotating cap and the freewheeling glider using a shield in the form of ledges that shield pinching gaps while power is effectively shielded in concert with the freewheeling outer race of the bearing or with the collar. 
     The described embodiments provide a practical and inexpensive solution to long-standing problem with trimmer operation. The bearings/collars can be attached independently or combined within other components to meet specific fitting needs. The system can be utilized for original equipment installation, or provided as an aftermarket product to specially fit common trimmers. 
     The use of bearings with a free-wheeling outer race or surface or a free floating collar prevents the initial gap pinching or binding at one end of trimmed long vegetation strands, reduces the rate of wrapping accumulations, and enables easy withdrawal of loosely accumulated strand wrappings. The system reduces or eliminates the binding of one end of the vegetation strand by shielding gaps where it may catch or pinch, and by shielding vegetation strands from rotating parts (under power) with the free-wheeling outer race of the bearing or with the collar. While loose windings may accumulate, they are not rigidly bound to the rotating member under power, providing for easier hand removal. That is, the free-wheeling outer surface of the bearing or the collar effectively reduce the rate of accumulation of wrappings because they disconnect the windings from the rotating arbor shaft that is under power. As such, tightening of the strands is eliminated. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.