CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority to U.S. Provisional Patent Application No. 61/564,927 filed Nov. 30, 2011, which is incorporated by reference as if fully rewritten herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention generally relates to trimmer heads for rotary trimmer machines using monofilament line as a means for cutting vegetation; and, more specifically to trimmer heads for rotary trimmer machines with carabiner style eyelets for improved loading of monofilament line. 
       BACKGROUND OF THE INVENTION 
       [0003]    Trimmer heads for rotary trimmer machines are known in the art. These trimmer heads generally carry one or two lengths of monofilament line wrapped about an interior spool with the ends of the line or lines projecting outwardly through opposed eyelets in the side wall of the trimmer head. The trimmer head is threadably mounted on the end of an elongated shaft and rotated at a high velocity by a gas or electric motor so that the ends of the cutting line project radially from the head and sever weeds or other vegetation. The cutting line may be paid out from the spool either manually or automatically as with bump-feed type trimmer heads. In either scenario, eventually the cutting line will be used up and the spool either replaced or replenished. When replacing the spool in the trimmer head, the ends of the cutting line must be threaded through the eyelets on the side wall of the trimmer head. This has often proven to be cumbersome leading to a need for a trimmer head with improved eyelets for loading trimmer line. 
       SUMMARY OF THE INVENTION 
       [0004]    In an embodiment, there is provided a trimmer head, including a housing having a recess, a trimmer line spool removably mounted in the recess in the housing, at least one exit opening on the housing wherein trimmer line wound on the spool passes through from within the housing, and a normally closed gate adjacent the exit opening, movable to an open position allowing passage of trimmer line from an open area adjacent the exit opening past the gate into a slotted area. 
         [0005]    In an embodiment, there is provided an adaptable trimmer head for a rotary trimmer machine, the trimmer head being adaptable for attachment to a clockwise rotating trimmer machine or a counter-clockwise rotating trimmer machine. The trimmer head including a housing having a recess, a reversible trimmer line spool removably mounted in the recess in the housing, a ground contacting member that when depressed into the ground when the trimmer head is rotating causes trimmer line to be dispensed from the trimmer line spool within the housing, wherein the trimmer line spool includes a first side that is attached to the ground contacting member when it is desired to rotate the trimmer head in a counter-clockwise direction and a second opposite side that is attached to the ground contacting member when it is desired to rotate the trimmer head in a clockwise direction, at least two exit openings on the housing wherein trimmer line wound on the spool passes through from within the housing, and a normally closed gate adjacent each exit opening, movable to an open position allowing passage of trimmer line from an open area adjacent the exit opening past the gate into a slotted area. 
         [0006]    In an embodiment, there is provided an eyelet for a rotary trimmer head configured to allow trimmer line wound onto a spool disposed in a housing of the trimmer head to pass from within the housing, including a U-shaped frame, a slotted area, an open area leading into the slotted area, and a pivoting gate normally biased into a closed position sealing the open area, and movable to an open position and configured to allow trimmer line to move from said open area past the gate into the slotted area, and then return to the closed position. 
         [0007]    In an embodiment, there is provided a method of installing trimmer line in a trimmer head of a rotary trimmer machine, including the steps of providing a housing having a recess, removably mounting a trimmer line spool in the housing, and passing trimmer line wound on the spool from within the housing through at least two eyelets on the housing by performing the steps of: urging free ends of the trimmer line against a pivoting gate normally biased into a closed position to an open position, said pivoting gate normally sealing an open area of the eyelet, moving the free ends of the trimmer line from the open area past the gate into a slotted area, and releasing the gate after the free ends of the trimmer line are disposed in the slotted area to allow it to return to the normal closed position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: 
           [0009]      FIG. 1  is a prior art trimmer head with conventional trimmer line eyelets; 
           [0010]      FIG. 2  is an embodiment of a trimmer head with carabiner style trimmer line eyelets; 
           [0011]      FIG. 3  is a side view of the trimmer head of  FIG. 2 ; 
           [0012]      FIG. 4  is a partially exploded perspective view of the trimmer head of  FIG. 2 ; 
           [0013]      FIG. 5  is an exploded perspective view of the trimmer head of  FIG. 2 ; 
           [0014]      FIG. 6  is a perspective sectional view of the trimmer head of  FIG. 2 ; 
           [0015]      FIG. 7  is a spool assembly for the trimmer head of  FIG. 2 ; 
           [0016]      FIG. 8  is a perspective sectional view of an indexing mechanism for use with the trimmer head of  FIG. 2 ; 
           [0017]      FIG. 9  is a top view of the indexing mechanism shown in  FIG. 8 ; 
           [0018]      FIG. 10  is an exploded view of the indexing mechanism shown in  FIG. 8 ; 
           [0019]      FIG. 11  is a front view of an embodiment of a carabiner style trimmer line eyelet for use with the trimmer head of  FIG. 2 ; and 
           [0020]      FIG. 12  is a rear view of an embodiment of a carabiner style trimmer line eyelet for use with the trimmer head of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Referring now to the drawing figures in which like reference designators refer to like elements, there is illustrated in  FIG. 1  a prior art trimmer head  10  having opposing conventional eyelets  30  configured to allow monofilament line L wound onto an internal spool  25  to exit from within the trimmer head housing  15 . The trimmer head  10  of the prior art is designed to be mounted on the extended end of a rotatable drive shaft (not shown) on a gasoline or electric powered rotary trimmer (not shown). A central threaded aperture  12  in the trimmer head housing  15  is provided for mounting the trimmer head  10  on the end of the rotatable drive shaft (not shown). The eyelets  30  may be received into slots formed in the trimmer head housing  15  in a press fitment. The eyelets  30  may be made of any material including plastic or metal and are formed with a central aperture for allowing the monofilament line L to pass there through. After the monofilament line L is wound by hand onto the spool  25 , the ends L′ of the monofilament line L are inserted into the eyelets  30  prior to the spool  25  being inserted into the trimmer head housing  15 . As the spool  25  is inserted into the trimmer head housing  15 , the monofilament line L is pulled through the eyelets  30  to take up any slack in the monofilament line L until the spool  25  is fully seated into the trimmer head housing  15 . A cap  20  may then be installed onto the trimmer head housing  15  to secure the spool  25  therein. 
         [0022]    Referring now to  FIGS. 2 and 3 , there is illustrated an exemplary embodiment of a bump-feed type trimmer head  100  having a pair of opposing carabiner style eyelets  175  (best seen in  FIG. 5 ) for improved installation of the monofilament line L as the trimmer line spool assembly  125  ( FIG. 4 ) is installed into the trimmer head housing assembly  115 . The use of the carabineer style eyelets  175 ,  175  eliminates the need to thread the ends L′ of the section of trimmer line L on the spool  125  into prior art eyelets  20  prior to installing the spool  125  into the housing assembly  115 . Instead, the free ends L′ of the section of trimmer line L are pushed through an open area  177  (see also  FIGS. 11 and 12 ) in each of the eyelets  175  and past a spring-loaded gate  178  into a slotted area  176  of the eyelet  175 . In addition to the housing assembly  115  and the spool assembly  125 , the trimmer head  100  may include a bump knob assembly  120  which is installed on the bottom of the housing assembly  115  as described in detail herein below. 
         [0023]    In an embodiment, an adapter kit (not shown) may be provided to install the trimmer head  100  on a trimmer machine (not shown) including fifteen or so nuts and bolts, and a few spacers packaged in a plastic bag. The first step for installing the trimmer head  100  on a trimmer machine would be to select a nut or bolt which mates with the corresponding threads on the shaft of the trimmer machine. Once the correct fastener is selected, the trimmer shaft is inserted into an aperture  112  in the trimmer head  115  and the fastener (not shown) placed in the hexagon passage  116  ( FIG. 6 ) of the housing assembly  115 . By spinning the housing assembly  115  relative to the threads on the shaft of a trimmer machine, the threads from the fastener (not shown) mate with the threads on the shaft of the trimmer machine. Sometimes spacers are required, but details regarding the use of spacers are known to one of ordinary skill in the art. 
         [0024]    Referring now to  FIG. 4 , the next step for the consumer is to attach the spool assembly  125  to the bump knob assembly  120 . If the consumer&#39;s trimmer machine was the type to rotate the trimmer head  100  counter-clockwise, then a first side L of the spool assembly  125  would mate with the resilient tabs  122 ,  122  extending from the bump knob assembly  120 . These two resilient tabs  122 ,  122  would be inserted into complementary slots  126 ,  126  (not shown) formed in the first side L of the spool assembly  125 . Conversely, if the trimmer machine had clockwise rotation of the trimmer head  100 , then a second side R of the spool assembly  125  would mate with the same resilient tabs  122 ,  122  on the bump knob assembly  120 . In this scenario, the resilient tabs  122 ,  122  would be inserted into a pair of complementary slots  126 ,  126  formed in the second side R of the spool assembly  125 . Once the spool assembly  125  is mounted to the bump knob assembly  120 , a composite spool and bump knob assembly  130  is formed. 
         [0025]    The above instructions for proper assembly of the bump knob assembly  120  to the spool assembly  125 , which are independent of one knowing the rotational direction of the trimmer, are rather complicated to communicate to a consumer. At one time, all straight shaft trimmers rotated counter-clockwise and all curved shaft trimmer rotated clockwise. This made it easier to provide installation instructions. However, this is no longer true. Some straight shaft trimmers now also rotate clockwise. Because of this confusion, it has been difficult for manufacturers of bump-activated trimmer heads to communicate to the consumer in simple instructions the proper way to configure the components (spool and line winding direction) of bump-activated trimmer heads for each individual consumer&#39;s trimmer machine. 
         [0026]    To solve this problem, there is one fact upon which a solution can be designed. All trimmer machines which rotate the trimmer head  100  counter-clockwise require left-handed threads if the trimmer head  100  is to stay on the trimmer machine during use. The trimmer head  100  will unscrew itself from a counter-clockwise rotating trimmer machine if right-handed threads are used. Likewise, all trimmer machines, whether straight shaft or curved shaft, will require right-handed threads to keep the trimmer head  100  attached if the trimmer machine rotates the trimmer head  100  clockwise. 
         [0027]    To solve the communication problem with consumers, the nuts and bolts provided with the subject trimmer head  100  may be pre-colored either black or yellowish-gold. The spool assembly  125  is also two colored: one part black and one part yellow/gold. The right-handed nuts and bolts supplied with the subject trimmer head  100  are colored black, and the nuts and bolts with left-handed threads are colored yellowish gold. The two-colored spool assembly  125  has been designed such that if a black nut or bolt is used (right-handed threads) for clockwise rotation of the trimmer head  100 , then the black portion or first side L of the spool assembly  125  is to be connected to the bump knob assembly  120 . Conversely, if the consumer uses a yellowish-gold fastener (left handed threads), then the yellow portion or second side R of the spool assembly  125  is attached to the bump knob assembly  120 . In other words, by color coding both the fasteners and the spool assembly  125 , this combination of indicia based upon color provides a solution to a problem that has long frustrated manufacturers of bump-activated trimmer heads. 
         [0028]    It is significant to note that the consumer only needs to perform the steps of assembling the bump knob assembly  120  to the spool assembly  125  once. Once the spool assembly  125  and bump knob assembly  120  have been combined for a given trimmer machine, there is no need to disconnect these two components. However, because the two components are reversibly connected, the consumer could later disconnect and reconnect the two components for a trimmer machine that operates in the opposite direction of rotation. The consumer could also replace the bump knob assembly  120  without having to replace the spool assembly  125 , or vice versa. This is one of the advantages of this trimmer head  100  arrangement. The trimmer head  100  is not only universally adaptable to any trimmer machine, but with the use of color indicia, any consumer can easily configure the trimmer head  100  for any trimmer machine. 
         [0029]    The final step for the consumer to install the trimmer head  100  on a trimmer machine would be to wind the monofilament line L onto the spool assembly  125 , tuck the ends into clips  135 ,  135  on the spool assembly  125  which hold the monofilament line L in place, and then press the ends L′ of the monofilament line L into the eyelets  175 ,  175 . The spool and bump knob assembly  130  is then slid onto an indexing mechanism  140  (see  FIG. 6 ) disposed in the housing assembly  115  and secured thereon with a twisting and locking motion. After a light tug on the two ends L′ of the monofilament line L, the consumer is ready to begin to use the trimmer head  100 . 
         [0030]    The foregoing arrangement will allow a pair of projections  141 ,  141  on the indexing mechanism  140  ( FIGS. 5 and 6 ) to slide within the length of a pair of complementary slots  138 ,  138  formed in the spool assembly  125 , and further into a pair of complementary slots  123 ,  123  formed in the bump knob  120 . The slots  123 ,  123  have a “L” shape orientation such that the projections  141 ,  141  on the indexing mechanism can lock into adjacent recesses or sockets  123   a ,  123   a  when the spool and bump knob assembly  130  are rotated relative to the housing  115  and indexing mechanism  140  in the twisting and locking motion. 
         [0031]    Another aspect of this invention is that once the consumer connects the spool assembly  125  to the bump knob assembly  120 , the consumer will only see one arrow on the exposed or non-attached side of the spool assembly  125 , which instructs the consumer as to the direction to wind the monofilament line L onto the spool assembly  125 . Many bump-activated trimmer heads in the prior art have two arrows on the spool assembly. One arrow indicates the direction to wind the line for left-hand rotating trimmers (counter-clockwise when viewed from above), and a second arrow in the opposite direction from the first, which indicates the direction to wind the line for right-handed rotation (clockwise if viewed from above). One aspect adding confusion for consumers is that the direction of rotation is reversed if viewed from above versus view from below. The arrows added to heads in the prior art were pointed based upon the direction of rotation being determined if viewed from above. However, the direction of rotation is reversed if viewed from the bottom side of the trimmer head  100 . And, the consumer is typically viewing the trimmer head  100  upside down when installing the monofilament line L. This level of confusion can cause a consumer to give up on using the trimmer heads described in the prior art. However, with the subject trimmer head  100  and the combination of color indicia, the consumer no longer has to remember whether the trimmer machine rotates the trimmer head  100  clockwise or counter-clockwise; the consumer does not have to select between two arrows to get the correct direction for winding the monofilament line L. Only one arrow is visible once the spool assembly  125  is attached to the bump knob assembly  120 . 
         [0032]    To wind the line L on the spool assembly  125 , the consumer would obtain a 10 to 20 foot long piece of monofilament line L. Ideally the length of monofilament line L would be the longest length that would fit onto the spool assembly  125  within the volume defined by the outer flanges  130 ,  132  and the inner flange  131 , their perimeter and the inside wall of the spool assembly  125 . The center point of the monofilament line L would be placed in one of the slits  136  formed in the inner flange  131  of the spool assembly  125 . The inner flange  131  has four slits  136  equally spaced along its perimeter. 
         [0033]    Next, the two ends L′ of the monofilament line L should be wrapped in the direction of the arrow shown on the outer flange (either  130  or  132 ) of the spool assembly  125 . One end L′ of monofilament line L would be wound into each segment of the spool assembly  125  and both portions in the same direction as the one arrow. When all of the monofilament line L is wrapped onto the spool assembly  125 , then the free ends L′ of the line L can be pressed into the two clips  135 ,  135  located on the perimeter of the inner flange  131 . The purpose of the two clips  135 ,  135  are to hold the monofilament line L while proceeding with the following steps. The use of the clips  135 ,  135  provides significant convenience to the consumer. 
         [0034]    The clips  135 ,  135  are on opposite sides of the spool assembly  125  one hundred eighty (180°) degrees apart. There should be about 6 to 8 inches of monofilament line L extend from the spool and bump knob assembly  130 . The free ends L′ of the monofilament line L may easily be pressed into the carabiner style eyelets  175 ,  175  as the spool and bump knob assembly  130  is assembled to the housing assembly  115 . As the spool and bump knob assembly  130  is assembled to the housing assembly  115 , the two projections  141 ,  141  on the indexing mechanism  140  slide into the pair of slots  138 ,  138  positioned along the inner sidewall of a central aperture  129  formed in the spool assembly  125  and the pair of slots  123 ,  123  fowled on the interior of the bump knob assembly  120 . When the projections  141 ,  141  reach the bottom of the slots  138 ,  138  and  123 ,  123 , then the user would twist the bump knob assembly  120  to force the projections  141 ,  141  into the sockets  123   a ,  123   a  formed adjacent to the slots  123 ,  123 . Or, the consumer can simply pull on the two ends L′ of the monofilament line L, which will also force the projections  140 ,  140  into the sockets  123   a ,  123   a.    
         [0035]    One of the common challenges with replacing the monofilament line L in a bump head type trimmer head is the challenge of winding the monofilament line L on the spool assembly and then placing that spool assembly back into the trimmer head; it requires some dexterity. Some manufacturers of trimmer machines have changed the bump head design to a quick loading type to make monofilament line L loading easier. In these cases, the monofilament line L is threaded through one eyelet of the trimmer head, through a channel on the spool assembly, and then out the other eyelet. Next, a knob or a portion of the trimmer head is turned which pulls the monofilament trimmer line L into the trimmer head as the monofilament line L is wrapped onto the spool assembly. 
         [0036]    There are several short comings with these “easy line loading” heads. First, because the monofilament line L is not wound tightly and because the monofilament line L is not wound in neat adjacent wraps, there can be a tendency for the monofilament line L to tangle and weld inside the trimmer head during use. Manufacturers of these “easy line loading” trimmer heads have solved this issue by limiting the length of monofilament line L wound into the trimmer head; typically less than ten (10) feet of monofilament line L can be used if one wants to avoid these tangling and welding problems. However, this shortening of the monofilament line L length is counter to one of the advantages of the bump feed heads. Commercial landscapers like the longer length of monofilament line L in the trimmer head to minimize the need to stop and replace the monofilament line L. 
         [0037]    Another shortcoming with the “easy line loading” trimmer heads is that it is difficult to thread the monofilament line L through the pathway provided. There are gaps between the inside of the eyelets and the monofilament line L channel passing through the spool assembly. Unless the consumer understands these shortcomings, there is a good chance that he or she will push the monofilament line L through the first eyelet but the tip of the monofilament line L will miss the entrance to the line channel. The monofilament line L will go into the volume of the trimmer head but the end will not exit the second eyelet. The user has to pull the monofilament line L out and try again. 
         [0038]    Another problem with these trimmer heads is that the ramps used to control the direction of rotation so that the monofilament line L is wound in the correct direction also prevents the trimmer head for being used for both clockwise and counter-clockwise rotating trimmer machines. 
         [0039]    Another solution to the problem of replacing the monofilament line L in a bump head has been for the manufacturer or retailer to sell pre-wound replacement spools. However, because some trimmer machines rotate clockwise and others counter-clockwise, the retailer has to offer at least two SKU&#39;s for each trimmer head; one replacement spool with monofilament line L wound clockwise and another with monofilament line L wound counter-clockwise. The two-piece spool assembly  125  overcomes the above deficiency and makes the spool assembly  125  suitable as a universal replacement SKU (one SKU) for the trimmer head  100 , regardless of whether the trimmer head  100  is attached to a trimmer machine that rotates clockwise or counter-clockwise. Either side of the spool assembly  125  may be reversibly attached to the bump knob assembly  120 . Attaching one side of the spool assembly  125  to the bump knob assembly  120  allows it to be used with clockwise rotating trimmer machines. Attaching the opposite side of the spool assembly  125  to the bump knob assembly  120  allows it to be used with counter-clockwise rotating trimmer machines. 
         [0040]    Obviously, other color combinations may be used other than yellow and black. However, the uniqueness of indicia stems from color coding both the spool assembly  125  and the fasteners, and doing so in a manner that simplifies the configuration of the trimmer head  100  for clockwise or counter-clockwise rotation. 
         [0041]    Referring now to  FIGS. 5 to 10 , four screws  143  are used to affix the indexing mechanism  140  to the housing assembly  115 . The indexing mechanism  140  selectively allows relative movement of the spool assembly  125  with respect to the housing  115  in response to bumping of the bump knob assembly  120  of the trimmer head  100  on the ground to pay out measured lengths of monofilament line L. The simplified pay-out indexing mechanism  140  includes a spring-loaded cam  144  and cam follower  142  arrangement. The cam  144  includes a central bore  145  having a hexagonal cross-section. This hexagonally shaped bore  145  abuts the hexagonally shaped cross-section of the passage  116  formed in housing assembly  115  such that the trimmer head  100  may be attached to the trimmer shaft using a variety of supplied fasteners. With the present invention, the consumer does not need to disassemble the indexing mechanism  140  from the housing assembly  115  to change the fasteners. The fact that the housing assembly  115  in the present invention is readily adaptable to a wide variety of trimmer machines without disassembling the line indexing mechanism  140  is heretofore unknown for bump heads that utilize an indexing mechanism  140  for indexing the payout of monofilament line L. 
         [0042]    Referring back also to  FIG. 4 , at the inside lower surface of the bump knob assembly  120  are two of the sockets  123   a  and  124   a  adjacent their respective slot  123  and  124 . The bump knob assembly  120  also includes two additional sockets  123   a ,  124   a , which are each opposite one-hundred eight degrees (180°) apart the corresponding sockets  123   a ,  124   a . All four of the sockets  123   a ,  123   a ,  124   a  and  124   a  are adjacent a corresponding slot  123 ,  124 . The purpose of the two pairs of sockets  123   a ,  124   a  is that one of these pairs of sockets will be used to lock the two projections  141 ,  141  extending from the cam follower  142 . The projections  141 ,  141  snap into the sockets  123   a  or  124   a  depending on which side of the spool assembly  125  is attached to the bump knob assembly  120 . This depends on the desired direction of rotation of the trimmer head  100 , i.e., clockwise or counter-clockwise. The snapping of the projections  141 ,  141  into one of the pairs of sockets  123   a ,  123   a  or  124   a ,  124   a  affixes the spool and bump knob assembly  130  to the cam follower  142 . 
         [0043]    The axial slots  138 ,  138  on the inside of the spool assembly  125  will align with two of the respective slots  123 ,  123  or  124 ,  124  associated with the sockets  123   a ,  123   a  or  124   a  or  124   a , such that the projections  141 ,  141  on the cam follower  142  may only interface with the corresponding sockets  123   a ,  123   a  or  124   a ,  124   a . For example, if the trimmer head  100  rotates clockwise, then the side R of the spool assembly  125  will be mated with the bump knob assembly  120 . This is the first or black side of the spool assembly  125 . This will cause the slots  138 ,  138  to align with the two sockets  124   a ,  124   a . As the trimmer head  100  rotates clockwise (when looking from above), any bumping action will create resistance to the rotation of the trimmer head  100 , and the forces generated will keep the projections  141 ,  141  on the cam follower  142  pressed into the sockets  124   a ,  124   a.    
         [0044]    Oppositely, if the trimmer head  100  rotates counter-clockwise, then the second side or side L of the spool assembly  125  will be mated with the bump knob assembly  120 . This is the yellow/gold side of the spool assembly  125 . This will cause the slots  138 ,  138  of the spool assembly  125  to align with the two sockets  123   a ,  123   a . Again, bumping the bump knob assembly  120  of the trimmer head  100  on the ground will create resistance to the direction of rotation of the trimmer head  100 , and the forces generated will keep the projections  141 ,  141  on the cam follower  142  seated in the sockets  123   a ,  123   a.    
         [0045]    As previously described, the simplified pay-out indexing mechanism  140  includes the spring-loaded cam  144  and the cam follower  142 . The cam follower  142  has an internal shape  142   a  as shown in  FIG. 8-10 . The cam  144  has an outer shape as best seen in  FIGS. 8 and 10 . The cam  144  includes two generally square layers  144   a ,  144   b  and each layer  144   a ,  144   b  includes a rounded arch  144   c  on each of the sides of the square, the arch  144   c  being disposed at the midpoint between the corners of the squares  144   a ,  144   b.    
         [0046]    The internal shape  142   a  of the cam follower  142  has been designed to work with the square layers  144   a ,  144   b  of the cam  144 . The internal shape  142   a  of the cam follower  142  includes four projections  143  spaced evenly ninety-degrees (90°) apart. The projections  143  have a radius of material  143   a  removed to allow for the arch  144   c  disposed at the midpoint of the sides of the cam  144  as the cam  144  is rotated. 
         [0047]      FIG. 6  in particular illustrates the trimmer head  100  with the indexing mechanism  140  in place. The housing assembly  115  includes a cylindrical section  117  with a hexagonal channel  116  disposed in this cylinder section  117 . A spring  150  is placed over the cylindrical section  117 . Next, the cam washer  149  is placed against the cylindrical section  117  using metal pins  148 ,  148  pressed into apertures formed in the cylindrical section  117  for alignment. The cam follower  142  and the cam  144  are then placed against cam washer  149 . While keeping the spring  150  under compression, the four screws  143  are added which connect the cam  144  to the cylindrical section  117  of the housing  115 . The spring  150  may now be released. The spring  150  is constantly providing a bias to keep the cam follower  142  urged away from the housing  115 . The proper connection of these components will leave a hexagonal cavity  116 ,  145  down the middle of the housing  115  and cam  144 . 
         [0048]    When the assembled rotating trimmer head  100  is bumped on the ground during use, the bumping action will created an upward movement of the spool and bump knob assembly  130 . Because the cam follower  142  is connected to the spool and bump knob assembly  130 , it too is pushed upward against the spring  150 . When this happens, the projections  143  on the cam follower  142  can move from a position of rest associated with a first square layer  144   a  to an adjoining second square layer  144   b  staggered forty-five (45°) degrees and stacked on top of the first square layer  144   a . The cam follower  140  and the spool assembly  125  which are connected will rotate approximately forty-five (45°) degrees relative to the housing assembly  115 . Then the projections  143  on the cam follower  142  will be pressed by the spring  150  back to the first square layer  144   a  where the cam follower  140  and the spool assembly  125  will again rotate approximately forty-five (45°) degrees relative to the housing assembly  115  before coming to a position of rest. These two forty-five (45°) degree rotations will allow a fixed length of monofilament line L to be released through the eyelets  175 ,  175  of the trimmer head  100  by centrifugal action, lengthening the monofilament line L extending from the trimmer head  100 . Changing the shape of the cam  144  along with the internal shape  142   a  of the cam follower  142  will change the amount of monofilament line L released. 
         [0049]    The bumping action can be repeated to release the monofilament line L stored on the spool assembly  125  until there is no monofilament line L left to release. 
         [0050]    Referring now to  FIGS. 11 and 12 , the eyelet  175  is illustrated which functions in much the same way as a mounting climbing carabiner loop having a sprung gate. There is a latch  178  pivotally attached via a pin  183  to the inside of one side of the “U” shaped or horseshoe shaped frames  179 . Additionally, the latch  178  is biased so that in the biased position, it traverses an open area  177  of the “U” shaped frame  179 . When a length of monofilament line L is moved in the direction of the open area  177  and urged against the bottom of the latch  178 , the consumer can easily press the monofilament line L through the open area  177  of the “U” shaped frame  179  into a slotted area  176 . The latch  178  is designed to pivot out of the way in the direction of arrow  300  as the monofilament line passes through the open area  177 . The latch  178  is designed so that once the monofilament line L reaches the slotted area  176 , then the monofilament line L is no longer pressing on the latch  178  and the latch  178  can return to its biased position. The monofilament line L is at this point captured in the slotted area  176  of the eyelet  175  and is surrounded on all sides by the eyelet  175 . The monofilament line L cannot be removed radially from the eyelet  175  without manually pressing the latch  178  against the biasing means  182 . However, the monofilament line L can travel axially through the slotted area  176  in the eyelet  175 . The latch  178  is held at a fixed position against a stop or surface  180  using a spring  182  or other biasing means. Optionally, the stop or surface  180  may include a secondary flange, lip or surface  181  on the upper portion of the primary stop  180 . The purpose of this flange  181  is to minimize radial movement by the latch  178  relative to the axis of rotation of the trimmer head  116 . 
         [0051]    The perimeter of the eyelet  175  contains a flange  185  that mates with a cutout on the housing  115 . The flange  185  of the eyelet  175  may include hole  186  that may be aligned with a hole  114  in the housing  115 . A pin  169  (see  FIG. 5 ) may be pressed into the two aligned holes  114  ( FIGS. 5) and 186  to prevent the removal of the eyelet  175  from the housing  115 . The eyelet  175  is preferably comprised of aluminum but any material known to one of ordinary skill in the art may be used. 
         [0052]    It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.
A trimmer head for a rotary trimmer machine includes a housing having a recess, a trimmer line spool removably mounted in the recess, at least one exit opening on the housing wherein trimmer line wound on the spool passes through from within the housing, and an eyelet disposed in the exit opening. The eyelet includes an open area leading into a slotted area, said open area being normally closed by a pivoting gate biased into the closed position, and movable to an open position allowing trimmer line to move through the open area past the gate into the slotted area. The trimmer line spool is reversible so that when installed in a first configuration, the trimmer head may be installed on a clockwise rotating trimmer machine, and when the trimmer line spool is installed in a second configuration, the trimmer head may be installed on a counter-clockwise rotating trimmer machine.