Note: Descriptions are shown in the official language in which they were submitted.
~99800
APPARATUS FOR Cu~ G VEGETATION
RAC~RoUND OF THE ~Nv~NllON
1. Field of the Invention
This invention relates to the cutting of vegetation
and more particularly, it relates to an apparatus for cutting
vegetation using a flexible non-metallic line member.
2. Description of the Prior Art
Prior to the Industrial Revolution, mankind was cutting
vegetation employing various tools containing cutting edges
such as sickles, scythes, scissors and like knife-edged
tools. After the Industrial Revolution, the householder
established a home having a lawn, garden and like vegetation.
After the mid-ninteenth century, the homeowner used lawn
care machines which followed basically the concepts of
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mechanized farming tools such as the reel mower, reaper
and side bar cutters. In general, these devices were man-
powered. Various types of manually-powered metal knife-
edged trimmers and edgers were also available to the home-
owner. In the early part of the twentieth century, internal
combustion and electrical powered machines became available
to the large estate and commercial lawn care artisans.
Smaller types of powered lawnmowers and edgers becamé
available after 1940. Then, the inexpensive gasoline and
electric-powered rotary blade lawnmowers, edgers and trimmers
became available to both homeowners and commercial workers.
In these devices, a metal blade was mounted upon a shaft
rotated at several thousand r-evolutions per minute in a
cutting plane. The ends of the blade were sharpened into
a knife-like cutting edge. These rotary blade devices cut
with a shredding or impact action in contrast with the
scissor-like clipping action of the reel lawnmower. However,
the economies of manufacture made the rotary-bladed motor-
powered lawnmowers, edgers and trimmers readily available
at low cost to the public.
The rotary-blade type lawnmowers, edgers and trimmers
have one serious defect. This defect resides in the cutting
action provided by the heavy metal blade whose cutting edges
are traveling at velocities approaching 10,000 feet per
minute. The cutting blade has a mass of several pounds,
so that the kinetic energy present at the blade's cutting
edge is tremendous. The rotating metal blades strike solid
objects such as rocks, metal, toys, etc., with great force.
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As a result, these objects are propelled from the cutting
blade at high velocities to cause serious injuries to a
human being in their path. Also, direct contact of a foot
or other part of a human structure with ~he rotating blade
will cause dismemberment or great mutilation. In the United
States within the last few years, ~here has been anually
over 70,000 reported accidents relating to rotary metal-
bladed lawnmowers, edgers and trimmers.
Extensive and expensive engineering and experimentation
have been performed upon the various types of rotary metal
cutting devices to reduce the inheeent serious hazard.
For example, specially-designed shrouds and dead man controls
have been proposed by Industry and governmental agencies
in an attempt to reduce the large numbers of serious and
disabling injuries. Considerable time has been expended
in experimentation to replace the rotary metal blade with
a flexible cutting element in rotary ~awnmowers, edgers
and trimmers. The direct substitution of a resilient rotary
blade, such as manufactured of laminated rubber, for rotary
metal blades had not been universally successful.
In the early 1960's, a trimmer-edger used a flexible
non-metallic line carried on a head rotated within a cutting
plane in cutting vegetation. In this device, a relatively
low-powered motor rotated a head at relatively high angular
speeds and carried a very thin, flexible line of a plastic
polymeric material. The device did not succeed operation-
~ise even in limited trimmer-edger applications because
of frequent line breakage, ineffective cutting properties
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~i~9l~300
and awkward structures. As a result, these devices found
no consumer acceptance as a safe substitute for metal-edge
rotary cutting devices.
The utility and structural problems of prior art flexible
non-metallic line devices for cutting vegetation were over-
come by the inventions which are embodied in U.S. patents
3,708,967; 3,a26,068; and 3,859,77~. These patents describe
apparatus for cutting, trimming and edging vegetation wherein
a flexible non-metallic line member of proper leng~h is
mounted in a proper head structure to prevent line breakage
during operation. The line member has a certain cross-
sectional size and a given relationship of peripheral velo-
city. These features provide-a proper, useful and user
acceptable device for cutting vegetation. Also, these novel
devices provide the most acceptable replacement to rotary
metal-blade cutting devices. The cutting devices described
in these patents have provided the homeowner and commercial
user with vegetation-cutting apparatus using a flexible
non-metallic cutting line operated in complete safety to
the user and with an optimized cutting efficiency approaching
the hazardous metal blade cutting devices.
These patents show devices provided with structural
features which allow the flexible non-metallic line to be
selectively extended by manual operation of the user. In
example, the user stops operation of the device and manually
pulls the line member to a desired extended length. In
larger vegetation-cutting apparatus, such as gasoline-powered
edgers and trimmers, line extension can be a hindrance to
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most efficient cutting operation. Frequent line extensions
result when the flexible non-metallic line members contact
.netal or concrete structures which causes fraying and breakage
of the line members.
There are a number of prior art devices which are
capable of providing the extension of the line member from
the vegetation cutter employing flexible non-metallic lines.
~owever, no device of the prior art has the capability of
being actuated by the operator during the operation to feed
a certain discrete length of line from the rotating head
member under direct mechanical control. Then, the line
is re-locked automatically within the head member. Exces-
sive amounts of line member cannot be discharged from the
rotating head at any time. Other features and results of
the present invention in an apparatus for cutting vegetation
using a rotating flexible non-metallic line will be apparent
from the following discussion.
SUMMARY OF THE INVENTION
In accordance with thi~ invention, there is provided
an apparatus for cutting vegetation which comprises a head
member arranged for rotation about an axis generally perpen-
dicuLar with a cutting plane. The head member is rotated
by suitable driving means. Line storage means provide a
supply of flexible non-metallic line member to the head
member. The head member has at least one line member exit
provided therein at a location spaced from the axis of
rotation. Feed means are present for feeding the line
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~l99~loo
member from the line storage means outwardly from the line
member exit into the cutting plane. The feeding of the
line member is assisted by the centrifugal forces generated
by rotation of the head member. Actuating means for selec-
tively changing the feed means from a line member non-feeding
condition into a line member feeding condition are provided
the user. The feed means is returned by a restoring means
into the line member non-feeding condition upon a substan-
tially certain discrete length of the line member being
1~ extended from the line member exit.
In specific embodiments of this apparatus, one or more
line members ma~ be carried upon the head member and extended
in unison to the certain discrete length from the line member
exits.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of an operator employing
one embodiment of an apparatus for cutting vegetation arranged
in accordance with the present invention;
FIG. 2 is an enlarged pictorial view of the lower end
of the apparatus shown in FIG. l;
FIG. 3 i5 a side view of one line member exit shown
on the apparatus of FIG. 2;
FIG. 4 is a vertical section taken through the apparatus
generally shown in FIG. 2;
FIG. 5 is an enlarged partial side view of the actuating
lever carried upon the apparatus of FIG. l;
FIG. 6 is a cross-section taken along line 6-6 of FIG. 4,
appearing with Figs. 1 and 2;
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FIG. 7 is a cross-section taken along line 7-7 of FIG. 4;
FIGS. 8, 11 and 14 are partial vertical sections taken
along line 8-8 of FIG. 4;
FIGS. 9, 12 and 15 are top plan views taken along line
9-9 of FIG. 8;
FIGS. 10, 13 and 16 are pictorial representations
of ratchet teeth carried upon the spool's lower extremity
shown in FIG. 8;
FIGS. 11, 12 and 13 show the spool of FIGS. 8, 11 and
14 advanced about 60 degrees in angular rotation from its
initial non-rotating position; and
FIGS. 14, 15 and 16 illustrate the spool of FIGS. 8,
11 and 14 having traversed the full angular displacement
and re-locked into non-rotating position.
DESCRIPTION OF SPECIFIC EMBODIMENTS
Referring now to FIG. 1 of the drawings, there is shown
an operator 21 using an apparatus 22 of the present invention
to cut grass or vegetation 23 growing along a walkway border.
Although the aPparatus ma~ be a lawnmower a~ edger
embodiment, it will be described herein as the "trimmer
22". However, the trimmer 22 includes elements common to
lawnmower and edger devices.
The trimmer 22 includes a source of operating power
which can be an internal combustion engine 26 carried at
one end of a drive tube 27 which extends downwardly to a
rotating head 28. The rotatin~ head carries one or more
flexible non-metallic line members 29, such as of a polymeric
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material (Nylon~). The motor 26 rotates the head at a
suitable angular velocity sufficient to extend the lines
29 from the axis of rotation into a cutting plane which
intersects the vegetation 23. The head 28 is preferably
rotated at a velocity optimi7ed with the weight of the lines
29 and their radial extension from the head 28. For example,
lines 29 have a diameter between 0.035 inches to 0.1~0 inches
extending radially 5 to 9 inches from the head 28, and the
head is revolved at between 2500 to 4000 rpm to provide
optimum results in cutting the vegetation 23.
The dri~e tube 27 carries a handle 31 which the operator
21 grasps with his hands. In addition, an over-the-shoulder
strap 32 is provided so that the trimmer 22 is more readily
balanced by the operator 21. An actuating lever 33 is mounted
upon the drive tube 27 adjacent the handle 31. Actuation
of the lever 33 by the operator begins the cycle whereby
the lines 29 are fed from the head until a certain discrete
length of the lines have been extended, and then automatic-
ally the lines 29 are re-secured to the head 28 against
unintended additional extension.
The operator 21 progresses along the border ~tting
the vegetation 23 at a suitable rate of advance determined
by the capabilities of the motor 26. When the lines 29
become shortened~ or it is desired to extend their length
from the head 28, or for other reasons, the operator moves
the lever 33 towards himself to actuate the line extension
cycle. Then the lever 33 is released and the line extension
cycle is completed automatically in the trimmer 22.
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~ eferring now to FIG. 2, there is shown an enlarged
pictorial representation of the lower portion of the trimmer 22.
The drive tube 27 contains internally a flexible drive cable
34 which is interconnected with the motor 26. The lower
extremity of thç cable 34 is connected with the head 28
and serves to rotate it about an axis of rotation normal
to the cutting plane. For this purpose, the tube 27 carries
a lower bushing assembly 36 which is secured by clampnut 37.
The bushing assembly 36 carries internal bearings to journal
the head 28 for rotation about an axis prescribed by the
drive tube 27 and bushing assembly 36. Each of the lInes 29
is carried upon a spool internal of the head 28. For example,
the dust cover 38 is broken a~ay to expose one spool 37.
The spool 37 carries a supply of the line 29 which extends
from the head 28 through a line exit 39. Referring momen-
tarily to FIG. 3, the line exit 39 may include a metal insert
41 which is apertured to permit the.traverse of the line
29 from the spool 37 outwardly of the head 28. The insert
41 provides a low-friction bearing and curvilinear surface
for the line 21 so that it is not injured by vibration-
induced friction and abrasion.
The specific internal arrangement of the head 28 is
more.apparent by referring to FIG. 4. The drive cable 34
extends downwardly in the tube 27 for connection to the
upper portion of a dive shaft 42 which is journaled by
ball bearing assemblies 43 and 44 within the bushing assem-
bly 36. The bearing assemblies 43 and 44 may be lubricated
through the mounting of a zerk 46 within the sidewall.of
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the bushing assembly 36. The annulus 45 about the shaft
42 is filled with grease for lubrication purposes. The
shaft 42 carries a snap washer 47 to limit downward movement
within the ball bearing 44. The lower portion of the shaft
42 is enlaryed to provide a seating shoulder 48 upon which
~eats the topmost surface 49 of the head 28.
Preferably, the head 28 is constructed from molded
plastic (Nylon~) with an upper cylindrical part 51 which
carries centrally an insert 52 which is mounted upon threads
53 formed on the lower end of the shaft 42. Preferably,
the insert 52 and threads 53 mate in a direction of rotation
opposite to the rotation of shaft 42 so that the head 28
does not become disengaged or loosened during operation
of the trimmer 22. The lower cylindrical part 54 of the
head 28 nests about tapered surfaces 56 of the upper part
51. The part 51 carries shoulder 57 to limit the engagement
of the lower part 54. The lower part 54 is secured to the
upper part 51 by a stud which threads into the threaded
insert 52. A resilient spacer 59 between the lower part
54 and the insert 52 reduces vibrations. With this arrange-
ment, the lower part 54 can be removed readily from the
upper part 54 for replacement or insertion of the spools
into the head 28.
The head 28 carries several spools 37. The number
of spools usually corresponds to the number of lines 29
which extend from the head 28. ~owever, it will be apparent
that a plurality of lines 29 could be carried on an indi-
vidual spool. Thus, four lines can be carried upon two
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spools, or if desired four lines could even be carried upon
one spool and thread the several lines 29 through their
respective exits 39 in the head 28.
The line-advancing.mechanism embodied in the present
invention can be utilized~irrespective of the number of
spools or lines to be employed.
As to each spool, the novel mechanism provides for
locking each spool against rotation in the head except
during the line feeding cycle activated by the operator
movi.ng the lever 33. During the line feeding cycle, each
spool is rotated through a predetermined angular displace-
ment to extend the certain discrete length of line from
the head. The spool rotates under direct mechanical control
and relocks automatically after rotation is complete. More
particularly, the spool 37 in the non-rotating condition
is biased in a direction towards the upper part 51 by a
spring 61 carried by the lower part 54 of the head 28.
The spring 61 does not have to have more than a few ounces
of compression in moving the spool 37 towards the upper
part 51. An upstanding cylindrical projection 62 is provided
on the lower part 54 to engage one or more convolutions
of the spring 61 so that it will be held in place when the
lower part 54 is removed from the upper part 51. The upper
portion of the spring 61 engages projecting shoulders 63
which are formed internally of the spool 37.
In the illustrated embodiment of the present invention,
the spool 37 has a cylindrical body 66 which carries the
shoulders 63. The body 66 also carries circular flanges
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67 and 68 which define a reel upon which the line 29 is
coiled for storage purposes. Although the spool 37 may
be construc~ed oE any material, it is preferably molded
from a thermal plastic su~h as high~strength polystyrene
polymer. The spool 37 an~ head 28 are provided with elements
for locking the spool 37 to the head so that the line 29
cannot be withdrawn or extended unless the lever 33 is moved.
When the lever 33 is moved, control elements produce a pre-
determined relative rotation between the spool 37 and the
head 28 so that a discrete length of line 29 is extended
from the head 28. In addition, these locking and control
elements provide for automatically re-locking the spool
37 to the head 28 whenever the certain discrete length of
line 29 has been extended from the rotating head 28. It
will be apparent that many locking and control elements
can be employed for these purposes. The following elements
have been found to be operative in one embodiment of the
trimmer 22 which has been reduced to practice. However,
other elements of like function and result can be used.
The spool 37 is arranged to be rotated through a certain
angular displacement which determines the certain discrete
length of line 29 to be extended from the rotating head
28. For example, the head 28 may be of such diameter that
a six~inch length of the line 29 provides desired optimum
operation. Thus, the spool 37 can be arranged to rotate
through an angular displacement permitting a one-inch length
of the line 29 to be extended selectively by the operator
21 who is using the trimmer 22 without interrupting his
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cutting operation. For example, the spool 37 can be rotated
through an angular displacement of 90 degrees relative to
the head 28 to provide the certain one-inch discrete length
of extension of the line 29. However, other angular displace-
ments of the spool 37 in accordance with the present invention
can be used where different certain discrete lengths of
line 29 are desired to be extended from the head 28.
The spool 37 carries a top hemispherical surface 69
which merges into a locking surface 71 adjacent the cylindrical
body ~6. The locking surface 71 engages a complementary
locking surface 72 formed on the upper part 51 of the head
28. As shown in the drawings, the surface 71 has a non-
circular configuration, and preferably is polygonal. For
example, the surface 71 can be formed by the equal sides
of a square with the complementary surfaces 72 having a
corresponding opening shape. Thus, the spool 37 can be
locked within the head 28 so as to prevent extension of
line at 90-degree angular displacements from any given
locked position.
The lower portion of the spool 37 as seen in FIG. 4
carries a control means so that the spool 37 can be angularly
displaced through a predetermined rotation relative to the
head 28 under direct mechanical control and only when the
locking surfaces 71 and 72 are out of engagement. With
this arrangement, the spool 37 rotates along the control
means within the head 28 so ~hat undesired lengths of the
line 39 cannot be thrown from the rotating head 28. It
will be appreciated that the line 29 extending several
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39800
inches from the head 28 can exert a pull of several tens
of pounds of tension. The control means carried upon the
lower portion of the spool 37 provide for controlled angular
displacement of the spool 37 within the head 2B irrespective
of the tension on the line 29.
The control means can be ratchet surfaces formed on
the spool 37 and the head 28. The spool 37 at its lower
extremity has a plurality of teeth 73 forming a ratchet
when engaged to complementary teeth 74 formed on the lower
part 54 of the head 28. The ratchet formed by teeth 73
and 74 is arranged to cooperate with the locking means
provided by the surfaces 71 and 72. For example, locking
surfaces 71 and 72 secure the spool 37 at 90 degrees of
angular displacement from any locked position in the head
28. The teeth 73 and 74 control the movement during rotation
of the spool 37 so that the completion of rotation places
the spool 37 in such angular position that the surfaces
71 and 72 re-engage after feeding the certain discrete
length of line 29 from the head 28. Thus~ depressing the
spool 37 to compress the spring 61 moves the locking surfaces
71 and 72 out of engagement and also causes the teeth 73
and 74 to physiGally engage for limiting rotation of the
spool 37 to the predetermined number of degreesO For example,
the locking surfaces 71 and 72 lock the spool 37 at 90
degree angular displacement from any locked position. The
teeth 73 and 74 permit the spool 37 to rotate only 90 degrees
in feeding the line 29 from the head 28.
Any suitable mechanism may be employed for the remote
(14)
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actuation by the operator 21 of the spool 37 from locked,
to controlled rotation in feeding out the certain discrete
length of the line 29, and ~hen to re-lock automatically
the spool 37 within the head 28. In the embodiment shown
in FI~5. 2 and 4, the operating lever 33 actuates a mechani-
cal cam for moving the spool 37 downwardly within the head
~8 to permit its rotationn For this purpose, an arcuate
or circular cam ring 76 is mounted for rotation cir~umfer-
entially in an enlar~ed portion 77 of the bushing assembly
36. The cam ring carries an ups~anding ear or projection
78 secured to the lower end o~ a bowden cable 79. The cam
ring 76 is rotationally mounted upon the enlarged por~ion
77 in a plurality of capbolts 81 which are threaded into
the bushing assembly 36O The cam ring 76 has slots cut
into its side walls for receiviny the capbolts 81 and to
provide limited angular movement relative to the bushing
assembly 36. The cam ring 76 has a downwardly-extending
circular slot through ~hich is extended an angular cam ~oot
82. The cam foot 8~ carries a sloping-walled surface 83
which engages the lower surace of ~ap bolt 81 and the upper
sur~ace 84 engaging the cam ring 76. The inclined surfaces
83 and 84 cooperate with the cam ring 76 and capbolt 81
so that a~ th~ cam ring 76 is rotated relative to the bushing
assembly 36, the cam foot 82 moves vertically downward into
engagement with the spool 37 and displaces it sufficiently
tha~ the locking surfaces 71 and 72 are moved ou~ of engage-
men and the teeth 73 and 74 ar.e moved into engagement~
Stated in another manner, the movement of the cam ring 76
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1~L998UO
with the lever 33 causes the cam foot 82 to move the spool
from a locked into an unlocked position and the teeth 73
and 74 to advance the spool 37 a predetermined angular
displacement. When the operator releases the lever 33,
the cam ring 76 returns into its normal operating position
responsively to the biasing of the helical spring 86.
Referring momentarily to FIG. 5, the upper end of the
bowden cable 79 extends from its sheath 87 adjacent a cable
clamp 88 to the lever 33. The lever 33 is movably mounted
upon the tube 27 by a clamp 89 with a securing bolt 91.
The lever 33 is shown in its position where the helical
spring 86 has returned the cam ring 76 into its normal
operating position. Moving the lever 33 towards the operator
21 rotates the cam ring 76 about a bushing assembly 36 and
causes the cam foot 82 to travel downwardly until the locking
surfaces 71 and 72 move out of engagement while the teeth
73 and 74 of the ratchet means are moved into engagement
so as to control angular displacement of the spool 37 within
the head 28.
Returning to FIG. 4, the cam foot 82 in normal oper-
ating position should not rest upon the topmost surface
69 of the spool 37. In addition, the downward displacement
of the cam foot 82 towards the lowermost length of travel
should be just sufficient so that the teeth 73 and 74 are
fully engaged. The enlargement 77 on the bushing assembly
36 may carry a bottom cover 92 to retain a bearing follower
93 and dust cover 94 in contact with the lower extremity
of the shaft 42. The upper portion of the enlargement 77
~16)
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1~9800
is preferably enclosed by the dust cover 38 which can be
secured by cap bol~s 96 to the bearing assembly 36.
The arrangement of the cam ring 76 and cam foot 82
carried at the bottom of the bushing assembly 36 may be
seen in more detail in FIG. 6.
Referring to FIG. 7, the lower connectiGn of the cable
79 to the cam ring 76 can be seen in greater detail. The
sheath 87 enclosing the cable 79 is secured by a clamp 97
beneath one of the cap bolts 96 holding the dust co~er 38
to the bushing assembly 36. The end of the cable 79 is
secured within the projection 78 so that reciprocation of
the cable 79 within the sheath 87 by operation of the lever
33 causes angular movement of the cam ring 76 relative to
the bushing assembly 36.
Referring now to FIGS. 8 thru 16, a description will
be given of the sequencing from a non-rotating condition
to control ro~ation and return to non-rotating condition
of the spool 37 whereby only a discrete length of the line
29 is extended from the head 28 for each operation o the
lever 33 by the operator 21 in use of the trimmer 22. In
FIGS. 8-10, the spool 37 is shown in a partially downwardly-
displaced position where locking surfaces 71 and 72 are
coming out of engagement while the teeth 73 and 74 are
beginning to engage. As can be seen in FIG. 9 r a small
amount of clearance exists between complimentary locking
surfaces 71 and 72 with the indexing of the spool 37 indi-
cated by an arrow 101 relative to the upper part 51 of the
head 28. In FIG. 10, there is a pictorial representation
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at the same moment as the teeth 73 and 74 have just begun
to engage a sufficient distance that the spool 37 could
not freely rotate within the head 28 whenever the locking
surfaces 71 and 72 come out of engagement. Also, the teeth
73 and 74 are positioned,to begin rotation of the spool
37 . An indicating arrow 102 is shown on the portion of
the spool 37 carrying the teeth 73 for indexing re~erence.
In FIG. 11, the same elements previously described
are shown when the cam foot 82 has moved the sE~ 7 down,
ward to the limit of its travel with the teeth 73 and 74
fully engaged. At this time, the spool 37 has moved a
substantial portion of its intended angular displacement
relative to the head 28. In reference to FIG. 12, the
indexing arrow 101 indicates this position where the surfaces
71 and 72 are completely out of engagement and the spool
37 has been rotated about 60 degrees in the head 28. In
FIG. 13, the teeth 73 and 74 are fully meshed with the
reference mark arrow 102 having moved a corresponding like
angular displacement.
Referring to FIG. 14, the cam foot 82 is shown as it
is moving upwardly responsive to the action of the spring 86
returning the cam ring 76 towards its original operating
position. At this time the locking surfaces 71 and 72 are
moving into a position where they are at engagement~ As
can be seen in FIG. 15, the reference arrow 101 has moved
the remainder of its angular displacement to the next locked
position of the spool 37 relative to the head 28. However,
as can be seen in FIG. 16, the locking surfaces 71 and 72
~18)
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have just begun to engage, and the teeth 73 and 74 are
slightly disengaged so that the spool 37 cannot spin freely
within the head 28. Thus, the teeth limit anguLar displace-
ment to that particular position where the spool 37 moves
upwardly to place the locking surfaces 71 and 72 into a
locked position.
As can be seen by reference to the FIGS. 8 thru 14,
the sequence timing between the engagement and disengagement
of the locking surfaces 71 and 72 and the disenyagement
and engagement of teeth 73 and 74 are such that at no time
when the spool 37 has been unlocked from the rotating head
28 can the spool 37 spin freely within the head 28.
The spool 37 carries the ratchet means formed by the
teeth 73 and 74 so arranged that complimentary surfaces
between the teeth have leading and trailing surfaces 103
and 104, respectively, arranged in a toothed configuration
for positive mechanical control of the spool member 37 while
rotating relative to the head 28 when the locking surfaces
71 and 72 are out of engagement. Preferably, the leading
surface 1~3 has an inclined surface less steep than the
trailing surface 104. With this arrangement, the initial
angular rotation of the spool 37 within the head 28 occurs
at a greater angular velocity over the first portion of
its angular displacement than during the second portion
of its angular displacement. This is preferred since it
is desired that the spool 37 not be moving at a high angular
velocity whenever the locking surfaces 71 and 72 begin to
come into engagement in the arrangement of elements shown
(19 )
~ 1
0
in FXGS. 15 and 16.
Although only one spool 37 has been described in con~
struction and function within the head 28, the drawings
show that four spools can be accomodated in the head 28.
All spools can be arrange~ in the same manner and construc-
tion with identical func~ioning to the spool 37 so that
a plurality of lines 29 are extended simultaneollsly under
the selective actuation by the operator 21 in use of the
trimmer 22.
From the foregoing descriptionr it will be apparent
that ~h~e h~s been provided in a~aratus a~ ~ethod a novel
apparatus uslng a rotating head with non-metallic flexible
line adapted to cut vegetation. In particular, the novel
apparatus includes a feed system for extending an incre-
mental length o line from the rotating head into the cutting
plane. However, at all other times the cutting line is
secured within the head against unintended unreeling. In
no event can an excessive or wasteful length of line be
extended rom the head. It will be understood that certain
changes or alterations of the present ~pparatus may be made
without departing from the spirit o~ this invention. These
changes are contemplated by and are within the scope o~
the appended claims which de~ine the invention. Additi-
onally, the present description is intended to be taken
as an illustration of this invention.
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