U.S. patent application number 15/865653 was filed with the patent office on 2018-05-17 for module for feeding trimmer line through the spool of a vegetation trimmer apparatus.
The applicant listed for this patent is George E. Alliss. Invention is credited to George E. Alliss.
Application Number | 20180132417 15/865653 |
Document ID | / |
Family ID | 62106192 |
Filed Date | 2018-05-17 |
United States Patent
Application |
20180132417 |
Kind Code |
A1 |
Alliss; George E. |
May 17, 2018 |
MODULE FOR FEEDING TRIMMER LINE THROUGH THE SPOOL OF A VEGETATION
TRIMMER APPARATUS
Abstract
A trimmer head for use with either clockwise or counterclockwise
trimmer heads, including the use of a bidirectionally dispensing
spool. Various locations of passages straight through the trimmer
head and spool are shown along with various locations of components
of the ratcheting mechanism to allow for winding of the trimmer
line on the trimmer head and for limiting the amount of line
dispensed during "bumping" of the trimmer head knob on the ground.
Additionally, an extended funnel into the passage can be provided
to facilitate entrance of trimmer line into the funnel even when
the line is not perfectly straight. Also, spokes can be used in
place of the flanges of the spool to save material and cost, while
still providing a guide and barrier between the line store
areas.
Inventors: |
Alliss; George E.;
(Fairmont, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Alliss; George E. |
Fairmont |
NC |
US |
|
|
Family ID: |
62106192 |
Appl. No.: |
15/865653 |
Filed: |
January 9, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15376474 |
Dec 12, 2016 |
9924631 |
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15865653 |
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14548392 |
Nov 20, 2014 |
9516807 |
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15376474 |
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61907883 |
Nov 22, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A01D 34/4161 20130101;
A01D 34/4163 20130101; Y10T 29/49826 20150115; Y10T 29/49838
20150115 |
International
Class: |
A01D 34/416 20060101
A01D034/416 |
Claims
1. A trimmer head for use with a trimmer machine, comprising: a
trimmer head having a housing and a spool rotatably mounted within
the trimmer head housing; said spool having a central core with an
axial opening extending therein, said spool defining at least a
first chamber for winding trimmer line threaded through said spool
and around the spool central core; a first spoke or a first region
of at least one flange extending outwardly from the central core in
a first direction and defining a first passage therein; a second
spoke or a second region of the at least one flange extending
outwardly from the central core in a second direction and defining
a second passage therein a pair of eyelets defined in the trimmer
head housing; wherein the pair of eyelets is alignable with the
first and second passages; a replaceable module engageable in said
spool; wherein the replaceable module defines a passageway therein
that connects the first passage in the spool to the second passage
in the spool; and wherein a length of trimmer line is routed
through the first passage, the passageway, the second passage and
the pair of eyelets; and wherein when a first replaceable module is
engaged in said spool the passageway is radial and routes the
trimmer line straight through the spool; and when a second
replaceable module is engaged in the spool the passageway is
non-radial and routes the trimmer line in a non-radial manner
through the spool.
2. The trimmer head as defined in claim 1, wherein the passageway
in the second replaceable module is curved.
3. The trimmer head as defined in claim 1, wherein the passageway
in the second replaceable module is straight.
4. A spool for use with a string trimmer head, said spool
comprising: a central core; at least one flange or at least one
spoke extending outwardly from the central core; a first passage
defined in the at least one flange or in a first spoke; a second
passage defined in the at least one flange a distance from the
first passage; or said second passage being defined in a second
spoke a distance from the first spoke; a replaceable module
engageable in a bore defined by the central core; wherein the
replaceable module defines a first passageway section that is
alignable with the first passage; and a second passageway section
that is alignable with the second passage; and wherein in a first
replaceable module the first passageway section and second
passageway section form a radial passageway for routing trimmer
line through the spool; and wherein in a second replaceable module
the first passageway section and second passageway section form a
non-radial passageway for routing trimmer line through the
spool.
5. The spool as defined in claim 4, wherein the first passageway
section and the second passageway section intersect with each other
and are adapted to receive a single length of trimmer line
therethrough.
6. The spool as defined in claim 4, wherein the first passageway
section and the second passageway section are separated from each
other; and each of the first passageway section and the second
passageway section are adapted to receive a separate length of
trimmer line therein.
7. The spool as defined in claim 4, wherein the first passageway
section and the second passageway section are straight.
8. The spool as defined in claim 4, wherein the first passageway
section and the second passageway section are curved.
9. The spool as defined in claim 4, further comprising: a first
funnel defined in the at least one flange or the first spoke, said
first funnel being in communication with the first passage; and a
second funnel defined in the at least one flange or the second
spoke, said second funnel being in communication with the second
passage.
10. The spool as defined in claim 9, further comprising: a V-shaped
or U-shaped slot defined in the at least one flange or the first
spoke, wherein the slot is in communication with the first funnel;
and wherein the slot extends inwardly from proximate an outer edge
of the at least one flange or the first spoke and towards the
central core.
11. The spool as defined in claim 10, wherein the slot tapers from
the outer edge towards an apex that is located proximate the
central core.
12. The spool as defined in claim 11, wherein a width of the anchor
slot at the apex is at least from about 1/2 up to about 3/4 of a
width of the trimmer line that is adapted to be engaged around an
exterior surface of the central core of the spool.
13. A module for engagement in a spool of a vegetation trimmer
machine; said module comprising: a disc-shaped body having an first
surface, a second surface and a peripheral wall extending between
the first and second surfaces; wherein the body is adapted to be
received into a bore defined by a central core of the spool of the
vegetation trimmer machine; a first trimmer line passageway defined
in the body, wherein the first trimmer line passageway originates
in a first opening defined in the peripheral wall of the body and
extends for a first distance into the body.
14. The module defined in claim 13, wherein the first trimmer line
passageway is radial.
15. The module defined in claim 13, wherein the first trimmer line
passageway is non-radial.
16. The module defined in claim 13, wherein the first trimmer line
passageway is straight.
17. The module defined in claim 13, wherein the first trimmer line
passageway is curved.
18. The module defined in claim 13, wherein the first trimmer line
passageway terminates in a second opening defined in the peripheral
wall of the body, where the second opening is spaced a distance
circumferentially from the first opening.
19. The module as defined in claim 13, wherein the body further
comprises a central hole that extends between the first surface and
the second surface; and wherein the central hole is adapted to
receive a fastener or a chuck or an arbor of a driveshaft of the
vegetation trimmer machine therein.
20. The module as defined in claim 19, wherein the first trimmer
line passageway bypasses the central hole.
21. The module as defined in claim 13, further comprising a second
trimmer line passageway that is defined in the body, wherein the
second trimmer line passageway originates in a second opening
defined in the peripheral wall of the body and extends for a second
distance into the body; and wherein the first trimmer line
passageway is adapted to receive a first piece of trimmer line
therein and the second trimmer line passageway is adapted to
receive a second piece of trimmer line therein.
22. The module as defined in claim 21, wherein each of the first
trimmer line passageway and the second trimmer line passageway
extends inwardly into the body from the peripheral wall and tapers
in size; said first and second trimmer line passageways each being
widest proximate the peripheral wall of the body and narrowest
remote from the peripheral wall.
23. The module as defined in claim 22, wherein each of the first
and second trimmer line passageways at its narrowest is of a
smaller cross-sectional dimension than an end of a trimmer line to
be received therein; and wherein the first and second trimmer line
passageways are adapted to engage the end of a respective one of
the first and second pieces of trimmer line therein by way of an
interference fit.
24. The module as defined in claim 22, wherein each of the first
and second trimmer line passageways is open at one of the first and
second surfaces and is closed along the other of the first and
second surfaces.
25. The module as defined in claim 22, wherein the first and second
trimmer line passageways are linearly aligned and opposed to each
other.
26. The module as defined in claim 22, wherein the first and second
trimmer line passageways terminate a distance away from each
other.
27. The module as defined in claim 22, wherein the body further
comprises a central hole that extends between the first surface and
the second surface; and wherein the first and second trimmer line
passageways extend inwardly toward the central hole but terminate a
distance away therefrom; and wherein the central hole is located
between the first and second trimmer passageways and is adapted to
receive a fastener or a chuck or an arbor of a driveshaft of the
vegetation trimmer machine therein.
28. The module as defined in claim 22, wherein each of the first
trimmer line passageway and the second trimmer line passageway is
non-radial.
29. The module as defined in claim 22, wherein each of the first
trimmer line passageway and the second trimmer line passageway is
curved.
30. The module as defined in claim 29, wherein the first trimmer
line passageway and the second trimmer line passageway curve in
opposite directions around a central region of the body.
31. The module as defined in claim 30, wherein the body defines a
central hole that extends from the first surface through to the
second surface; and wherein the first trimmer line passageway and
the second trimmer line passageway curve in opposite directions
around the central hole; and wherein the central hole is adapted to
receive a fastener or a chuck or an arbor of a driveshaft of the
vegetation trimmer machine therein.
32. A storage spool for a vegetation cutting tool coupled to a
portable gas or electric-powered vegetation cutting machine
comprising: a central core; at least one pair of spokes extending
radially outward from; a wall of the core; at least one flange
extending radially outward from the wall of the core; at least one
line storage space; at least one unobstructed line guide channel
with at least one funnel shaped opening adapted for direct
alignment with at least one opening provided in at least one outer
trimmer head housing for loading and dispensing of trimmer
line.
33. The storage spool as defined in claim 32, wherein the core, the
at least one pair of spokes and the at least one flange are
integrally formed with each other and the spool is a single unitary
component.
34. A storage spool for a vegetation cutting tool coupled to a
portable gas or electric-powered vegetation cutting machine
comprising: a central core; at least one pair of spokes extending
radially outward from a wall of the core; at least one line storage
space; at least one unobstructed line guide channel with at least
one funnel shaped opening adapted for direct alignment with at
least one opening provided in at least one outer trimmer head
housing for loading and dispensing of trimmer line.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/376,474, filed Dec. 12, 2016, which is a
continuation in part of U.S. patent application Ser. No.
14/548,392, filed Nov. 20, 2014, now U.S. Pat. No. 9,516,807, which
claims the benefit of U.S. Provisional Application 61/907,883,
filed Nov. 22, 2013; the entire specifications of which are
incorporated herein by reference.
BACKGROUND
Technical Field
[0002] In general, the present invention relates to string trimmers
and the rotating heads of string trimmers. More particularly, the
present invention relates to the mechanisms contained within string
trimmer heads for winding, holding and dispensing new lengths of
trimmer line when needed.
Background Information
[0003] String trimmer machines have been commercially sold for over
a quarter of a century. In this period of time, there have been
many variations to the design of the string trimmer machine and
especially to the trimmer head.
[0004] The trimmer head is the part of the string trimmer machine
that is rotated by the drive shaft of the trimmer machine. The
trimmer head holds lengths of trimmer line that rotate with the
trimmer head. The rotating trimmer line contacts and cuts
vegetation as it spins.
[0005] Depending upon the make, model, and manufacturer of the
string trimmer machine, the trimmer head rotates either clockwise
or counterclockwise during operation. The trimmer head is affixed
to the string trimmer machine by a bolt or nut to the terminus of
the drive shaft of the string trimmer including any extension
thereto. Threading direction of the bolt or nut is determined by
the rotation direction of the drive shaft so that the trimmer head
does not unthread from the string trimmer during operation. The mix
in the current retail market is roughly evenly split between
clockwise and counterclockwise rotating string trimmer
machines.
[0006] There are many types of trimmer heads on the market. The
most common types of traditional trimmer heads are the bump-feed
trimmer head and the automatic-feed trimmer head. Both types of
trimmer heads contain an internal spool that holds a reserve of
wound trimmer line. As the trimmer line wears away, it can be
replaced from the internal spool. In a bump-feed trimmer head,
short lengths of line are released from the spool when the bottom
of the trimmer head is impacted or "bumped" against a hard surface.
In an automatic-feed trimmer head, a short length of line is
released from the spool without the operator having to manually
strike or bump the bottom of the trimmer head on the ground. Many
mechanisms exist in the prior art for controlling the release of
wound trimmer line from the internal spool of a trimmer head.
Bump-activated trimmer heads are exemplified by U.S. Pat. No.
5,881,464 to Collins, entitled Line Head for Flexible Line Trimmer.
Automatic-feed trimmer heads are exemplified by U.S. Pat. No.
5,060,384 to Everts, entitled Automatic Head for a Line Trimmer;
U.S. Pat. No. 5,109,607 to Everts, entitled Automatic Line Trimmer
Head; and U.S. Pat. No. 4,566,189 to Muto, entitled Filament Type
Trimmer Apparatus Cutters.
[0007] The primary problem associated with such traditional trimmer
heads is one of reloading. In order to replenish and reload new
trimmer line into the trimmer head, the trimmer head must typically
be disassembled and the internal spool removed. This process is
often too difficult for many homeowners to complete successfully or
even attempt.
[0008] Another common problem that often accompanies bump-feed
trimmer heads is the problem of line twisting string on the spool.
Most bump-feed trimmer heads contain two lengths of trimmer line
that extend from opposite side of the trimmer head. Bump-feed
trimmer heads rely upon centrifugal forces to pull the trimmer
lines from the spool. If the trimmer lines tangle, twist or become
buried under subsequent windings or fuse together from heat, the
trimmer lines may not dispense in the proper manner. The trimmer
head must then be disassembled, the trimmer string unwound and
again rewound in the proper manner before the trimmer head will
again work as designed. Furthermore, whenever the trimmer string
supply is exhausted, the trimmer head must be manually
disassembled. The spool is removed and rewound with a new supply of
trimmer line. The spool is then reassembled back into the trimmer
head. This process is difficult, labor intensive and highly time
consuming.
[0009] Another problem associated with traditional automatic-feed
trimmer heads is the complexity and reliability of the release
mechanism that draws trimmer line from the spool when needed. As
many homeowners will attest, the mechanism for releasing the
trimmer line is usually the first part of a string trimmer machine
that fails to work.
[0010] Yet another disadvantage of some prior art trimmer heads is
that they are designed to rotate in only a single direction, that
is, the trimmer head is designed only to be mounted on a clockwise
trimmer or on a counterclockwise trimmer but not both. Accordingly,
a trimmer head designed for a clockwise trimmer may not work on a
counterclockwise trimmer. Furthermore, some parts from a clockwise
trimmer head cannot be interchanged with any of the parts from a
counterclockwise trimmer head. This requires a trimmer head
manufacturer to create two sets of manufacturing tools, one for
clockwise trimmer heads and one for counterclockwise trimmer heads.
This significantly increases the cost associated with manufacturing
trimmer heads. Furthermore, it results in each trimmer head design
having two different models, one for clockwise rotation, and one
for counterclockwise rotation.
[0011] A need therefore exists for a string trimmer head that has
an inexpensive yet reliable mechanism for dispensing trimmer line
when needed. A need also exists for a string trimmer head that
dispenses trimmer line with less likelihood that the trimmer line
will tangle, twist, or bind. Furthermore, a need exists for a
trimmer head that does not have to be disassembled to have new
string added. Lastly, a need exists for a trimmer head that can be
manufactured inexpensively with few operating parts and can operate
either as a uni-directional or bi-directional trimmer head on
trimmer machines. These needs are met by the present invention as
described and claimed below.
SUMMARY
[0012] The present invention is to a trimmer head assembly and the
method of configuring the trimmer head assembly. The trimmer head
assembly attaches to a string trimmer machine. The trimmer head
assembly holds lengths of trimmer line that cut vegetation when the
trimmer head assembly spins and contacts the vegetation.
[0013] The trimmer head assembly has a housing that attaches to the
string trimmer machine. A spool is provided inside the housing. The
spool rotates about an axis of rotation. The spool can move
longitudinally along the axis of rotation between at least a first
position and a second position. A ratcheting mechanism and an
indexing mechanism are provided between the trimmer head housing
and the spool. When the spool is in its first position, the
ratcheting mechanism enables the spool to continuously or
discretely rotate about the axis of rotation in the direction
opposite that in which the trimmer head assembly spins. The
ratcheting mechanism also prevents the spool from rotating within
the housing in the either direction when unintended and only allows
rotation in the trimmer line winding direction when sufficient
torque is applied.
[0014] Using the ratcheting mechanism, new trimmer line can be
wound onto the spool, simply by anchoring the trimmer line to the
spool and manually turning the spool. No disassembly is required.
Preferably the string/line can be fed straight through from one
eyelet to the other eyelet ("straight through") prior to winding
the line onto the trimmer core.
[0015] In operation, an activation mechanism is provided for
momentarily moving the spool from its first position in the housing
to its second position. The activation mechanism can be automatic
or bump activated. Once momentarily in its second position, the
indexing mechanism enables the spool to turn so that a small length
of the trimmer line can unwind from the spool.
[0016] It is an object of the invention to provide improved
elements and arrangements thereof in an apparatus for the purposes
described which is inexpensive, dependable and fully effective in
accomplishing its intended purposes.
[0017] For the purposes of this application, a
"bidirectionally-operable trimmer head" is defined as a trimmer
head that can be assembled with the line (subsequently or
previously) wound around the trimmer head spool and mounted to
either a clockwise trimmer machine or to a counterclockwise trimmer
machine, wherein the trimmer head will dispense line outward when
activated regardless of whether the trimmer head is currently
rotating in the clockwise or counterclockwise direction because the
spool can rotate in a direction independent of the trimmer head to
dispense a length of line outwardly. In a bump-activated trimmer
head, the centrifugal force on the line overcomes the rotational
forces on the spool to allow it to rotate in the direction to
release an amount of trimmer line even if the spool rotation
direction is opposite to the current trimmer head rotation
direction during line dispensing and the spool rotational velocity
is faster than the trimmer head rotational velocity when both are
rotating in the same direction. A "wound trimmer head" is defined
as a trimmer head having a trimmer line wound on the spool
thereof.
[0018] It is an object of the invention to provide a
bidirectionally-operable trimmer head for mounting the same
assembled, wound trimmer head for use with either a clockwise or
counterclockwise trimmer head.
[0019] These and other objects of the present invention will be
readily apparent upon review of the following detailed description
of the invention and the accompanying drawings. These objects of
the present invention are not exhaustive and are not to be
construed as limiting the scope of the claimed invention. Further,
it must be understood that no one embodiment of the present
invention need include all of the aforementioned objects of the
present invention. Rather, a given embodiment may include one or
none of the aforementioned objects. Accordingly, these objects are
not to be used to limit the scope of the claims of the present
invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] FIG. 1 is a cross-sectional view of a trimmer head according
to a first embodiment of the invention.
[0021] FIG. 2 is an exploded view of several of the components of
the trimmer head of FIG. 1.
[0022] FIG. 3 is a perspective view of the trimmer head spool of
FIG. 11.
[0023] FIG. 4 is an exploded view of the trimmer head of FIG.
1.
[0024] FIG. 5 is a cross-sectional view of an alternative version
of the trimmer head of FIG. 1.
[0025] FIGS. 6-8 show views of a trimmer head according to a third
embodiment of the invention having a center flange.
[0026] FIGS. 9-12 show views of a trimmer head according to a
further embodiment of the invention having a flangeless spool.
[0027] FIGS. 13-14 show views of a trimmer head according to a
further embodiment of the invention having passages in the bottom
flange of the spool.
[0028] FIG. 15 shows an alternate spool having multiple passages
therethrough for use with at least one embodiment of the
invention.
[0029] FIGS. 16-20 show views of a trimmer head according to a
further embodiment of the invention having a non-circular
spool.
[0030] FIG. 21 shows an alternate spool having spokes instead of a
center flange for use with at least one embodiment of the
invention.
[0031] FIGS. 22 and 23A-B show alternate spools having multiple
passages therethrough for use with at least one embodiment of the
invention.
[0032] FIG. 24 shows a trimmer head according to a further
embodiment of the invention having a modular passage through the
center of the spool.
[0033] FIG. 25A-E shows alternate modules having various
passageways through the center of the spool for use with at least
one embodiment of the invention.
[0034] FIGS. 26A&B and FIG. 27 show various components of the
trimmer head of FIG. 24.
[0035] FIGS. 28A&B show an alternative spool arrangement having
passages through the bottom flange for use with at least one
embodiment of the invention.
[0036] FIG. 29 shows an alternative spool having no passages
through a flange of the spool for use with at least one embodiment
of the invention.
[0037] FIG. 30 shows another embodiment the spool having a module
for selectively changing the course of the line into or through the
spool.
[0038] FIGS. 31A, 31B, 31C, and 31D show a number of modules that
may be used with the spool of FIG. 30.
[0039] FIGS. 32A & 32B shows a variation on the slot in the
central flange or central spoke of the spool for facilitating
winding of the line onto the spool.
[0040] FIG. 33 is a magnified view a slot analogous to that shown
in FIG. 32B with a smaller taper.
[0041] FIG. 34 shows a cross-sectional view of a spool with the
slot of FIG. 33.
[0042] FIG. 35 shows a front plan view of a spool having a slot as
shown in FIG. 33.
[0043] FIGS. 35-38 show an embodiment of a spool for a trimmer head
having an extended funnel. FIG. 35 is a perspective view. FIG. 36
is a cross-sectional view. FIGS. 37-38 are environmental views.
[0044] FIG. 39 shows a front plan view of a spool having a slot as
shown in FIG. 33.
[0045] Similar reference characters denote corresponding features
consistently throughout the attached drawings.
DETAILED DESCRIPTION
[0046] The present invention relates to straight through feed
trimmer heads for string line trimmers.
[0047] FIGS. 1-4 shows a sectional view of a first embodiment of a
trimmer head 10 for use with a string trimmer machine (not shown).
The trimmer head affixes to a string trimmer machine drive shaft
arbor (including any extension thereof) (not shown) by a bolt, nut
or other fastener 12 in a form and specification as required to
mate with the respective arbor. Typically, the direction of
threading of the fastener is selected so that during normal
rotation of the drive shaft, the fastener will tend to tighten
rather than loosen from the arbor. The fastener 12 allows the
trimmer head 10 to rotate as a unit with the drive shaft to drive a
trimmer head line 14 in a radius outwardly from the trimmer head.
The trimmer head line 14 is well known in the art and may be made
of plastic or other material and is rotated at a high speed to cut
grass, weeds or brush that the line comes in contact with and is
available in a number of line diameters. U.S. Pat. No. 8,025,249
issued Sep. 27, 2011 to George Alliss shows one such configuration
and operation of a string trimmer head, which patent is
incorporated herein by reference.
[0048] The upper housing 21 includes a non-circular "keyed" chamber
23 (FIG. 4) for receiving (or acting as) the fastener 12 and to
prevent the fastener from rotating relative to the housing. The
chamber 23 is shown as being octagonal, but the shape may be chosen
to accommodate whatever fastener is used to connect the housing to
the arbor. The fastener is typical a bolt or nut is forward or
reverse threading.
[0049] A core 16 is provided within the trimmer head 10 to receive
the trimmer line thereabout as it is wound into the trimmer head.
The core is selectively rotatable relative to the housing. A pair
of eyelets 18 are provided on the outer housing 20 to introduce the
trimmer line into the interior of the housing. The eyelets are
preferably 180 degrees apart from each other, but in some
circumstances may be more or less than 180 degrees apart and may
include fewer or more eyelets. The eyelets may include a metal
guard or other sleeve for resisting wear as the line 14 within the
eyelet is moved about or through the eyelet.
[0050] The core preferably may have a central opening or chamber
defined by inner wall(s) 22. Preferably the trimmer core 16
preferably includes a central, straight through guide passage
("channel") 24 therethrough. The passage 24 preferably has a first
opening selectively alignable with (or being positioning relative
to) one of the pair of eyelets 18 of the housing to feed a trimmer
line therethrough and a second channel opening alignable with the
second of the pair of eyelets 18 when the first opening is aligned
with the first eyelet. The alignment of the channel and eyelets
allows a trimmer line to be fed from the first eyelet through the
first channel opening, through the channel and out through the
second opening and second eyelet when feeding the trimmer line onto
the trimmer head. An indicator 31 (FIG. 4) viewable from outside
the trimmer head may be provided so that the user is aware when the
core 16 and housing are aligned and ready for receiving the line.
In a preferred embodiment, the indicator is on the knob viewable
from beneath the trimmer head.
[0051] FIG. 2 shows a preferred configuration of the core of the
trimmer head. In order to wind and release trimmer line from the
trimmer head, a ratchet system and an indexing system are provided.
The ratchet system includes a first system for winding the trimmer
line. The figure shows the trimmer head core 16 with a trimmer line
14 fed therethrough. A knob 30 for engaging and rotating the core
16 is shown below the core. A lower housing 32 which forms part of
the outer housing 20 is shown below the knob. The knob 30 has a
number of preferably non-circular arms/splines 34 which are
received within a mating receiver of the core 16 to securely rotate
the knob and core together when required. The lower housing 32
cooperates with the upper half of the housing 20 to secure the knob
and core therein with a portion of the knob 30 extending through an
opening 33 in the lower housing. The upper 23 and lower 32 housing
may be connected by a number of methods or systems, but are
preferably connected by a quick release system such as by flexible
arms/fingers 25 and cooperating holes 27 interference fit with each
other.
[0052] Additionally, the core and upper and lower housing cooperate
to form an indexing system and ratchet mechanism for feeding and
controlled release of the trimmer line. In the position shown in
FIG. 1, the eyelets 18 and feed channel 24 are aligned allowing a
length of trimmer line 14 to feed through the outer housing through
the core and out the other side. The knob 30 can be rotated to wind
the line onto the core 16. The core has an upper disk 36 and a
lower disk 38 which form upper and lower boundaries of the lower
chamber 57 for the trimmer line to be wound on the core. The upper
chamber 59 is formed by the upper disk 36 and a shelf 61 of the
housing as describer later hereinunder. As shown in FIG. 3, the
openings 40 of the feed channel 24 have an opening on the side for
directing the line onto the core. As the core is rotated clockwise
in the FIG. 3, the line will resist turning by friction, inertia
and other forces acting on the line outside of the housing 20. The
core will turn away from the trimmer line entrance, and the inner
wall 42 will begin to pull the trimmer line as the core continues
to turn. The line will then begin to be pulled into the housing as
the line wraps around the inner wall 42 of core 16. As the user
continues to rotate the core via knob 30, cogs 44 on the lower disk
38 will rotate. A number of ramps 46 on the lower housing are
arranged to interfere and impede the rotation of the cogs within
the housing during normal operation of the string trimmer machine.
It should be noted that a spring 50 is provided above the core to
bias the core downward but which allows for axial movement of the
core (and attached knob) under a preselected force.
[0053] One purpose of the obstructions is so that the core cannot
"freewheel" when the housing is turned by the string trimmer. It is
desired that the core and housing turn together during normal
operation so that the trimmer line is maintained at a constant
length. If the core were allowed to turn, then the trimmer line
could unintentionally wind or unwind as the housing turned relative
to the core.
[0054] In order to continue to wind the line onto the core, the
user applies enough torque on the knob to force the cogs 44 of the
core past the ramps 46. The ramps are oriented such that rotation
in the proper direction (in the example, clockwise, but one skilled
in the art would recognize that the ramps could be arranged to
rotate only clockwise, only counterclockwise or in both clockwise
and counterclockwise directions by having one ramp or by having two
opposing ramps back to back) causes the cog to move up and over the
ramp. When turned in the opposite direction (for one way ramp
configurations), the cog will strike a vertical wall of the ramp
(or other similar obstruction) and further torque will not promote
further rotation of the knob and core. As the cog moves up the
ramp, the core 16 will move axially upward compressing spring 50.
As the cog moves up and over the ramp, the spring will then force
the core axially downwardly with the cog axially aligned with the
next ramp. This ratcheting system allows the direction of winding
to be controlled and also provides a control for allowing only a
certain amount of line to be released. One way ratcheting has the
advantage of ensuring that the line only winds one way onto the
core and the line cannot be "fouled" by turning the core in the
"wrong" direction.
[0055] The trimmer line during winding will be forced into one of
two chambers 57, 59. The side port opening 41 of the passage
determines whether the particular end of the line will wrap into
the lower chamber 57 or upper chamber 59. As shown in the front of
the FIG. 3, the port 41 at the front directs line into the lower
chamber 59 which is bound by upper and lower flanges 36,38 (FIG.
3). The rear port 41 (FIG. 2) directs line 14 onto the upper
chamber. The upper chamber in this embodiment as best shown in FIG.
2 is bound at the lower end by upper flange 36 and at its upper end
by a surface/shelf 61 of the housing 20. Preferably the shelf 61 is
smooth to reduce any drag or friction of the trimmer line on the
shelf as the spool rotates relative to the housing. The interior
wall of the chamber is preferably provided by the core of the
flange which rotates about the circular wall 65. Similarly the
lower edge of the spool may rotate while being supported for
rotation by a lower circular wall 67 of the housing which encloses
the spool or both the spool and knob ("activation mechanism").
[0056] As is known in the art, the user taps the string trimmer
head on the ground to release an amount of string. In the present
invention, this is accomplished by depressing the knob further into
the housing ("axially upward") causing the core 16 to move upwardly
against the bias of the spring 50. The axial movement is sufficient
to raise the cogs 44 of the core 16 above the ramps 46. This frees
the core 16 to free spin relative to the housing 32 in either
direction. The direction of the spin (relative to the housing) will
be controlled by the forces on the trimmer line 14 and the
direction that the line is wound on the core, not by the direction
of the trimmer head. This results in a bidirectionally operable
trimmer head that can be mounted to a clockwise or counter
clockwise trimmer head regardless of the direction the line in
wound on the trimmer head. Regardless of whether the trimmer head
is spinning clockwise or counterclockwise, the forces on the
trimmer line will act to pull the line outward as the centrifugal
force on the line pulls the line outwardly. The outward force will
act to unwind the line by pulling the line and rotating the core in
the proper direction to unwind the line. Since the cogs are
temporarily axially upward of the ramps 46, the core is free to
spin in either direction (relative to the housing) and will move in
the proper direction to unwind the line regardless of the direction
of rotation of the trimmer head.
[0057] Another function of the trimmer head is to control the
amount of rotation during the free spin when feeding line outward.
This is desirable so that only a small bit of line is fed out to
replace line that has been worn down or cut during trimming of
brush or weeds. The user can repeat the process described by
"bumping" the knob again if further amounts of line are needed. The
line control indexing feature in the embodiment illustrated is
performed by a number of upward protrusions 52 ("square teeth")
provided on the upper area of the core. The amount of string/line
14 released during one bump is controlled by the spacing between
stop bars 54 on the upper section 21 of housing 20. The core 16 may
rotate in the free spin mode at most until the protrusions hit one
of the stop bars halting the rotation of the core. As soon as the
pressure on the knob is released the core will drop back down to
its original axial position under the bias of spring 50. The core
may then rotate until a cog 44 runs into an interfering ramp. The
centrifugal forces on the line will prevent the cog from further
turning up the ramp which would cause the trimmer line to retract
onto the spool. A cog turning the opposite direction would strike
the vertical wall of the ramp and would thereby be prevented from
rotating further. In this way, bumping the knob will allow the core
to free spin relative to the housing, but the amount of
(bi-directional) free spin will be controlled by the teeth 52 and
stop bars and the spring will return the core to the original axial
position where the ramps will prevent the core from turning past a
ramp by the interaction of the ramps and cogs. It should be noted
that even if the teeth do not hit the stops, the bias of the spring
will bring the cogs and ramps back into align acting as a failsafe
to prevent unintended amounts of line from being released in a
single bump.
[0058] Bidirectional dispensing. A result of the specific
organization of the trimmer head is that once the line is wound on
the trimmer head, the trimmer head can dispense line properly no
matter which way the trimmer head is rotating. Typically the
trimmer line is wound on a trimmer head so that hitting the
knob/bump on the ground slows the spool relative to the housing.
The housing can thus rotate to unwind the line from the spool as
the eyelets contacting the trimmer line unravel a length of line
from the spool. The current trimmer head has a separate mode where
the spool can also speed up relative to the trimmer head housing to
"push" the line outward. In actuality, it is the centrifugal force
on the line from the length of the line outside the housing plus
the frictional contact of the line with grass or weeds or other
material that pulls the line against the spool causing tension in
the trimmer line. Trimmer heads built in accordance with at least
one aspect of the present invention allow the spool to "free wheel"
relative to the housing for a brief interval. During this interval
the line can actually pull the spool faster than the housing to
release an amount of line. Preferably, one of the stops prevents an
undue amount of line from being released at the time. This ability
to release the line by being able to both speed up relative to the
housing or to slow down relative to the housing during dispensing
of the line outwardly from the spool to allow the spool to dispense
trimmer line independent of the direction of rotation of the
trimmer head is defined for the purposes of this application as
"bidirectional dispensing" or "bidirectional line dispensing." A
trimmer head that is capable of bidirectional dispensing is
"bidirectionally operable." The direction of winding of the line on
the trimmer head is defined herein as the direction in the line
would be wound relative to the spool to release/dispense trimmer
line when the spool slows relative to the trimmer housing, i.e.,
winding a trimmer line clockwise on the spool would allow a
counterclockwise rotating trimmer head to dispense line from the
spool when the knob is "bumped" on the ground to slow the spool
relative to the housing to allow the housing to unwind a length of
trimmer line to dispense that length of line outward through the
eyelet of the housing as the housing rotates counterclockwise
faster relative to the spool.
[0059] FIG. 5 shows an alternative construction for the first
embodiment. In this configuration, the ratchet on the bottom of the
lower disk 38 are formed by teeth or gears 60 and the ramps 62 on
the lower housing 32 have been moved inwardly to accommodate the
location of the gears 60. One skilled in the art would recognize
from the teachings of the present invention that the functional
components of the ratchet (stop bars, teeth/gears, and ramps) could
be located on any of the various surfaces of the core as needed to
perform the function of providing a winding ratchet and a line feed
control function without departing from the scope of the
invention.
[0060] FIG. 24 shows an alternative version of the invention
according to a further embodiment. The spool 2416 is splined to
knob 2430 through spline 2434 and cooperating slots and grooves on
the knob 2430 so that the spool and knob will co-rotate together.
FIGS. 26A&B show the combined spool and knob 2433 and profiles
of the ramps and cogs thereon. Ramps, stops and cogs are each
preferably provided to allow the spool to wind spool in a
particular direction and to index the amount of line dispensed can
be controlled. A feature shown in FIG. 24 that can be used with any
of the other embodiments is a module 2470 that can be installed
within the spool 2416. The module aligns with the passages 2440 of
the spool and provides/controls routing of the trimmer line within
the core of the spool from one flange passageway to the other
flange passageway. The module may have a key, tooth, spline, groove
or other device so that it is aligned properly with the spool. The
module may be reversible or rotatable to change the orientation,
path or alignment of the module with the spool. The module is
preferably switchable with other modules to control the path
through the core to route the line in various paths. The module
provides flexibility such as routing around a driveshaft, bolt or
other similar device (if any) by providing a curved path 2472
(FIGS. 25A&B) or to route straight though the center 2470 (FIG.
24). Depending on the shape of the path through the flange (or
wing), additional paths could also be used. FIG. 25C shows a
one-sided curved path 2474 that leads through a corresponding spool
flange (not shown). FIG. 25D shows a spiral path through the center
of the module 2476 that leads to a corresponding spool flange
having spiral, non-radial passages therethrough (not shown). FIG.
25E shows a module 2478 having a plurality of passage for use
selectively with 1-2 trimmer lines through a cooperating flange
having corresponding passages (not shown) for each of the two
module channels. FIG. 27 shows a module 2470 installed within the
spool 2416.
[0061] FIGS. 28A&B show an embodiment of the invention similar
to that of FIG. 1, however the channels 2840 are provided in a
lower flange instead of the upper flange 40. One skilled in the art
would appreciate that the eyelets 2818 of the housing would have to
be aligned with the lower flange in this embodiment instead of with
the upper flange. Preferably the cogs 2844 are also reversed from
the bottom flange to the top flange.
[0062] FIGS. 6-8 show another embodiment of the invention having an
example of variation in the placement of the ratchet components and
includes a central flange for dividing the trimmer line into an
upper and lower chamber. In FIG. 6, a central core 116 of a trimmer
head 110 has a number of cogs 152 on an upper disk 138 that
cooperate with a number of stops 154 (FIG. 7) provided in the upper
portion 121 of the housing. The followers 144 on core 116 and ramps
146 on lower housing 132 cooperate to form the trimmer line winding
ratchet. The spring 150 biases the core 116 into proper axial
position as discussed above. In this embodiment, the knob 132 is
preferably formed as an integral part of the core 116.
[0063] The core 116 has a different configuration for accepting an
amount of trimmer line onto the core 116 into two separated
chambers. By separating trimmer line as it is fed in through the
left and right eyelets 118 into separate chambers, there is less
chance that the line will tangle with itself and can avoid line
"fusing" to itself. Because trimmer line can be thicker and stiffer
than for example "fishing line," the line can tend to straighten
itself out ("unspool") in the trimmer head and then tighten in use.
These cycles can cause the line to wind on itself or even weld/fuse
to itself under the heat of friction. Separating the lines can
lessen the chance of these problems and increase the ease and
reliability of feeding out line during operation. To facilitate the
line winding onto the two chambers (instead of all the line feeding
into on chamber), the openings 140 on either side on the center
flange 137 open on diverse sides of the flange. One opening has its
mouth 141 opening above flange 137 to feed line into the chamber
formed between the upper disk 136 and flange 137. The opposite
opening 40 is the mirror image with a mouth opening towards the
bottom of flange 137 to feed line into the chamber formed by flange
137 and disk 138.
[0064] In operation, knob 130 is rotated to cause followers 144 to
rise up and over ramps 146 to allow the core 116 to rotate relative
to the housing 121,132. The rotation of the core causes line fed
through the housing eyelets 118 through the trimmer line feed
channel opening 40 and out the opposite eyelet to wrap around the
core 116. Because of the varied orientation of the mouths of
openings 140, different portions of the line will wrap into the
individual chambers formed above and below flange 137. When trimmer
line is required to be fed out to increase the length of the active
cutting section of the line, the use will strike ("bump") the knob
on the ground of other surface. The bump will cause the followers
144 to lift above ramps 146, and centrifugal on the trimmer line
will cause the line to pull against the core to rotate the core in
the direction (relative to the housing) necessary to feed the line
outward, regardless of the overall rotational direction of the
trimmer head. The rotation of the core relative to the housing will
be checked by the cogs 152 striking the stops 154 to control the
amount of line fed during one "bump" of the knob 130.
[0065] FIGS. 9-12 show an alternative embodiment having a
flangeless core and which distributes some of the ratcheting
components to a knob separated from the core. FIG. 9 shows an
exploded view of the trimmer head 210. The core 216 is rotatingly
tied to the knob 230 by arms/splines 233 engaged with corresponding
slots 235 that will cause the knob and core to fixedly co-rotate
together. The knob and core and bias spring 250 are located and
biased into position between the lower housing 232 and upper
housing 221. A number of square teeth 252 cooperate with
corresponding stops on the upper housing 221 to form the feed
control ("indexing") mechanism as described above to limit the
amount of line fed out during "bumping" of the trimmer head knob
230.
[0066] The upper housing 221 has a guide wall 253 (FIG. 12) for
receiving the outer wall of the core. The guide wall serves a
number of purposes. Firstly, it centrally locates the core 216
within the housing. With the knob 230 centered in lower housing 232
and the core located in the upper housing 221, the core and knob
will be guided to rotate securely within the housing about a fixed
axis. Additionally, the guide wall causes the square teeth 252 to
properly align with stop bars 254 as described above. The stops and
teeth will limit the amount of free rotation of the core during
"bumping" and will only dispense a limited amount of line per bump.
It should be noted that while the wall 249 of the upper housing 221
is shown as surrounding and securing the core 16, it is preferable
that the wall 249 is provided within the core (see for example,
FIG. 1) so that the core can rotate about the wall 249. This allows
the line to wrap around the upper section of the core instead of
around the upper housing wall 249, which lessens the friction on
the line as the core rotates independent of the housing 221.
[0067] The lower housing includes a number of followers 244 that
cooperate with the ramps 246 (FIG. 11) to provide the ratcheting
function to allow winding of the trimmer line onto the core 216
while preventing unintended rotation of the core relative to the
housing. In operation, the spring 250 biases the core downwardly.
The core 216 presses down on the knob, which forces the ramps 246
and followers 244 into axial alignment. Rotation of the core
rotates the knob until the ramps engage the followers. If the
torque on the knob is increased, such as by manually turning the
knob 230, the followers will force the ramps upward against the
bias of the spring 250. If enough torque is applied, the ramps will
pass over the followers 244 and the spring will force the ramps
back down into alignment with the followers in a ratchet-like
motion. The rotation allowed by passing the ramp over the follower
will allow the core to rotate relative to the housing to wind
additional line around the core. The axial spacing of the ratchet
mechanism may be such that the height that the knob moves as the
ramp goes over the follower is insufficient to bring the square
teeth 252 into engagement with the stop bars 254 and thus the stops
will not interfere with the rotation of the core during winding of
the line onto the core as the knob is rotated.
[0068] The core 216 itself is flangeless. It does not require an
upper or lower disk or a central flange to coordinate the winding
of line onto the core. The core has a number of arms 217 that
extend the length of the trimmer line feed channel 224 from one
eyelet 218 to the other. The channel terminates into opposing
openings 40. The opening on one side of the channel has a mouth 41
opening upwardly and the other opening has a mouth opening
downwardly. Line fed upwardly feeds into an area of the housing
bounded by the arm 217 and the upper housing 221. The guide wall
253 prevents the line from interfering or entangling with the
rotating core or with the square teeth 252 at the upper end of the
core. Line fed downwardly feeds into an area of the housing bounded
by the arm 217 and by the lower housing 232. Additional line that
feeds in as the core rotates past the eyelet again continues to
wind onto the proper area above or below the arm 217 because the
line is pulled above or below the eyelet by the length of line
already within the housing. The distance that the walls 249 of the
opening of the channel extend above the arm, for example, helps
ensure that further line will also be fed in above the arm since
that section of the line is already biased in that direction
pulling the line above (or below as needed) the arm. In this way,
the core does not require a top, bottom or center flange to control
the orderly storage and maintenance of line within the trimmer head
housing.
[0069] FIG. 21 shows an alternative embodiment of the invention
having an upper and lower flange, but no center flange. The spool
2116 has an upper flange 2136 and a lower flange 2138. This could
for example be used in place of the spool of FIG. 6. Appropriate
cogs, ramps and/or stops could be provided as necessary to mate
with ramps, cogs or stops on the housing. A bump knob (not shown)
could be provided that would mate at the bottom of the spool or
provided integral to the spool. In operation, a line fed through
the opening 2140 would be fed through the other side to openings
(118, FIG. 6) in the housing.
[0070] As the spool was rotated, the line would feed out the side
openings 2141 of the spoke or wing 2117 and would wind around the
central wall 2111 of the spool. A flange is not required because
the spokes would act to separate the line into the top or bottom
opening according to whether the channel opening 2141 opened to the
top or bottom of the wing 2117. In practice, during the next
rotation around the line in the top chamber will be taught and
spaced above the top 2119 of the spoke 2117. The spoke can be
flared (expanded in the radial direction) to help ensure that the
line wraps in the proper direction. This will act to pull the next
bit of line still above the wing so that it also wraps in the top
chamber. Line in the bottom chamber will analogously wrap in the
bottom chamber. The top and bottom flanges will act to maintain the
line on the spool. Additional spokes or wings could be provided
about the core of the spool. These additional spokes could have
passages therethrough to allow additional trimmer lines to be used
or can be used as alternate passages in case the primary passage
through the spool is blocked by a broken line or the like. The
additional spokes could also be provided without passages (not
shown) therethrough to help ensure that the line continues to wind
into the proper channel as line control spokes. The spool will
otherwise act in a similar mode to that of FIG. 6.
[0071] FIGS. 13-14 show a further embodiment of the invention. FIG.
13 is a cross-sectional view of a trimmer head 310 utilizing a core
316 having no bottom flange. As seen in FIG. 14, the core 316 has a
central flange 317 with a straight through trimmer line feed
channel 324. An upper disk 336 (FIG. 14) carries cogs 352 that
cooperate with stops 354 on the upper housing 321 to form the
trimmer line dispensing control mechanism. The channel 324
terminates in a pair of opposed openings 340. One opening biases
trimmer line into a chamber formed between the upper disk 336 and
the central flange 317. The opposite opening has a mouth that
biases that section of trimmer line downward to the area of the
housing formed between the flange 317 and the interior of the lower
housing 332 and the knob 330. The knob may have an upper surface
("shelf") 339 to prevent line accumulating thereon from spreading
into unintended areas during rotation and to define a lower chamber
for receiving line therein. A lower tubular portion 374 of the core
316 may be provided to extend into knob to further secure the core
to the knob and to promote rotation of the core about the central
axis of the trimmer head. Since the core 316 and the knob are fixed
together by a slot 370 and groove 372 on the core extension 374,
the line will rest on the upper surface as the knob and core
co-rotate therewith. To release trimmer line, ramps 346 on the knob
cooperate with followers on the lower housing (see FIG. 9,
reference 244) to allow the trimmer line to be wound onto the core
316 as discussed above.
[0072] FIG. 15 shows an alternative embodiment of a trimmer head
having more than one trimmer head feed channels 424 ("passage").
The core 416 provides a number of feed channels 424. The channels
may be connected to the appropriate opposing or adjacent channel by
passages 420 in a central module 422 in the core 416 so that the
line fed through one channel 417 feeds out of a second channel in
the core 416. See FIG. The number of lines that can be fed through
simultaneously is controlled to one line by the number of eyelets
on the outer housing (see for example, FIG. 1) and is typically
only one line. However, it may be desirable to provide additional
channels on the core 416 for various reasons including in case one
channel gets blocked by broken line or debris. Additionally,
channels could be provided to receive different types/diameters of
trimmer lines or for other purposes. The channels could cross each
other in the middle so that are in communication with each other or
one or more of the channels could each bend slightly so that the
channels cross over each other. Depending on the requirements of
the core 416, the openings on each channel could cause the line to
all flow into one chamber or to divide onto either side of the
channel. The channels could be configured alike or in different
configurations as needed. The multiple channels could be provided
on a central flange or on a top or bottom disk or on a flangeless
core. FIG. 22 shows a similar four channel spool 2216 having four
channels/passages 2217 in a central flange. Preferably, the
channels openings at the opposite end of the passage would lead
into the same chamber to separate the winding of the two trimmer
lines.
[0073] FIGS. 23A&23B show spools 2316 having passages 2317 in a
top flange and in a bottom flange respectively. The spool and
trimmer housing could also be configured to have passages in both
of the top and bottom flanges at the same time to provide for the
attachment of multiple trimmer lines or to provide an alternative
mounting spot for a trimmer line when one passageway is blocked. A
central flange could be provided so that both ends of the trimmer
line from the top flange are stored in the top chamber and both
ends of the trimmer line from the bottom flange are stored in the
bottom chamber.
[0074] FIG. 29 shows an alternative version of the spool 2916. In
this embodiment there is no path/channel/passage through the center
flange. Instead, there are two passageways extending through the
spool, each 90 degrees from each other, so that two trimmer lines
can be extended through the spool. Each passageway has a
terminating opening/hole 2940 at each end of the passage. The
opening 2940 in the core of the spool determines whether the line
will wrap into an upper chamber or into a lower chamber.
Preferably, the hole at the opposite end of the passage would lead
into the same chamber to separate the winding of the two trimmer
lines. The drawback to this design is that it may require an
artificial aid to thread the line through the eyelet and through
the spool. This could be accomplished several ways including the
use a straw or other device or by disassembling the trimmer head to
thread the line properly. For these reasons, this design is less
preferable to other designs, but may accomplish goals at a lower
cost, for example.
[0075] FIGS. 16-20 show an additional embodiment according to at
least one aspect of the invention having a non-tubular core. FIG.
18 is a cross-sectional view of the trimmer head 510. The trimmer
head 510 includes an upper housing 521 (FIG. 19) and a lower
housing 532 (FIG. 20) with a core 516 (FIG. 16), a spring 550 and a
knob 530 (FIG. 17) housed therein.
[0076] The upper housing 521 has a keyed chamber for receiving a
fastener to connect the trimmer head 510 to the arbor of a string
trimmer machine. The housing interior is shaped through a number of
spacers 519 around the wall to receive the outer diameter of the
flange 517 so that the core 516 rotates within the housing about a
central axis. That is, the core can rotate without undue wobbling,
etc. The housing has a number of eyelets 518 that may include metal
or plastic guards or sleeves to prevent wearing of the housing as
trimmer line 514 is added to or removed from the housing. The upper
housing 521 is connected to the lower housing as appropriate.
[0077] FIG. 20 shows the lower housing having flexible collet-like
fingers 525 that secure within openings 527 within upper housing to
provide a quick release connector between the upper and lower
housing. Pressing the fingers 525 inwardly releases the fingers
from the openings 527 so that the housing can be separated into the
upper and lower housing parts. Likewise, knob 530 can be secured to
the core 516 by fingers 76 cooperating within openings 576 on the
core or by other fasteners or threading. The walls of the key 578
on the knob are dimensioned and shaped to fit within an opening on
the bottom of the core 516. Preferably the opening is the same
shape and dimensions as the inner walls 578 of the core to securely
receive the knob so that the knob cannot rotate relative to the
core. One skilled in the art would recognize that the invention
could be practiced regardless of the shape chosen for the knob's
key and the corresponding opening in the core as long as they can
cooperate with each other.
[0078] The core has a center flange 517 for separating the incoming
halves of the trimmer line 514 into a lower chamber formed between
disk 538 and flange 517. Trimmer line above the flange 517 is
retained within the space between the flange 517 and the upper
housing 521. The trimmer line as discussed above is fed from
outside the housing through an eyelet 518 through the channel 524
and out the other eyelet. The line is then fed onto the core by
turning the knob, which rotates the core 516 to wrap the line
around the core. Cooperating ramps 546 and followers 544 control
unintended rotation of the core relative to the housing, while
allowing desired rotation by turning the knob with sufficient
torque to cause the ramps to move past the followers for the
desired amount of travel as discussed above.
[0079] The presently described embodiment preferably does not
include an indexing system having separate stops and cogs or square
teeth. The stops are utilized in some of the embodiments to control
the amount of line fed through the eyelets per "bump" of the knob.
It has been found that the amount of line fed out during a "bump"
can be adequately controlled simply from the ramps and followers.
When the knob is bumped or pressed by a quick tap of the trimmer
head on the ground, there may be a small time gap before the core
actually begins to turn. If the rebound force of the spring 550 is
specified properly and the number and positioning of the ramps is
properly built into the trimmer head, then the return time that it
takes to press the core back down into the original position and
place the ramps on or between the followers is sufficient to only
allow a small amount of rotation of the core before the ramps hit a
follower and stop rotation of the core relative to the housing. In
this way, the use of only the ramp and follower portion of the
ratchet system is sufficient to perform both functions of allowing
winding and controlling trimmer line feed.
[0080] It will be understood that the embodiments of the present
invention that are illustrated and described are merely exemplary
and that a person skilled in the art can make many variations to
those embodiments. For instance, the number of cog projections,
ramp projections and stop projections can be varied provided the
numbers for these elements remain equal. Likewise, the shape of the
bump knob, the shape of the housing and the shape of the spool can
be varied into numerous configurations that are not illustrated.
All such embodiments are intended to be included within the scope
of the present invention as defined by the claims. None of the
embodiments need include any or all of the features of the
invention.
New Embodiments
[0081] FIG. 30 shows another embodiment of a spool 3010 having a
module for selectively changing the course of the line into or
through the spool. The spool in combination with the knob 3030 can
be provided with ramps, cogs, etc. necessary to interact with a
trimmer head housing (not shown) to provide unidirectional or
bidirectional operation to dispense trimmer line (not shown) as
discussed in relation to the embodiments above and in the prior
art. The spool may have one or more line receiving chambers to wind
the trimmer line about the spool. Separate chambers for each end of
the line to wrap around can prevent the line from "fusing" to other
portions of the line by lessening the overall friction and heat on
the line.
[0082] In the past, spools have used extensive flanges (see for
example, FIG. 8, reference 137) to separate the line into an area
above and below the flange 137 as the line wraps around the spool
core. The present invention according to some embodiments of the
invention can use spokes 3019 instead of the flange to reduce the
weight and material when manufacturing the spool. The number of
spokes can be increased or decreased as necessary to ensure that
the trimmer line properly wraps above or below the center line and
cannot "cross over" from one chamber into the other chamber. The
shape and width of each spoke can be chosen to increase the
integrity of the line wrapping. It may also be preferable to
increase the height (i.e., along the line parallel to the axis of
the spool) to effectively separate the wrapping of the line in one
chamber from the other. See for example, FIG. 21. Since the spokes
are only acting as a separator and are not under unduly large
forces, the spokes offer a lower cost option to a central flange by
saving material and weight.
[0083] The embodiment of FIGS. 30-31 may also take advantage of the
use of modules to convert the spool from a "straight
through/radial" spool to a non-radial routing. The easiest way to
route a trimmer line through a spool is to have a large opening
that extends directly across one the spool along any diameter of
the spool, often called the "radial" direction since the line
extends from the center of the spool along a radius of the spool as
well. See for example, FIG. 24 and module 2470 that route a trimmer
line straight through ("radially through") the spool. There may be
advantages to routing the trimmer line along non-radial paths as
well, for example to provide a little bit more friction to the line
so that it is easier to thread and begin winding of the line,
without having the line shift unintentionally within the spool. See
for example, FIGS. 25A-D.
[0084] FIGS. 31A-E show various module arrangements that can be
used to provide optional routing into or through the spool 3010.
FIG. 31A shows a radial interference fit module. The module has a
trimmer line opening 3177 to receive the trimmer line. By
necessity, the opening is larger than the trimmer line so that the
trimmer line can be threaded into the line receiving slot.
Typically trimmer line is produced in a number of standard sizes in
the diameters of 0.065'', 0.080'', 0.095'', and 0.105''. The
terminal end of the line receiving slot 3181 has a diameter smaller
than the line that it receives. In this way, the trimmer line can
be interference fit inside the slot such that the line is pushed in
to slightly compress the trimmer line within the slot to anchor the
line in the slot. The amount of force required to properly seat the
trimmer line in the slot is slight because the line will
immediately be bent more than 90 degrees as it is wrapped around
the core of the spool. the bending torque on the line and the
interference fit will both increase the friction resisting the line
from coming out of the slot as the line is wrapped around the spool
Once the wrap has completed a complete revolution around the core
and preferably additional wraps around the spool, the line is
secure enough that the line can be used by the rapidly rotating
trimmer head to cut grass or weeds without having the line end come
out of the slot. When the line has been worn down to a very short
length and is no longer wrapped around the core, then the remaining
line may be automatically ejected out of the line receiving slot
and out of the spool under the centrifugal force produced by the
rotating trimmer head. Alternatively, the residual line can be
pulled easily out of the line receiving slot and a new line can be
inserted and wound around the spool.
[0085] FIG. 31B shows a curved ("non-linear") line receiving slot
3183 for receiving trimer line. As in FIG. 31B, instead of using a
single piece of trimmer line threaded through the spool core with
roughly half of the line extending out each side of the spool, the
line receiving slots require that more than one trimmer line
segment be threaded through the plurality of line receiving slots.
In FIG. 31B, there are two slots for receiving two total trimmer
line segments. One skilled in the art would recognize that more
than two slots could be provided for receiving one trimmer line
segment in each line receiving slot. One skilled in the art would
also recognize that the number of slots and number of lines should
each be chosen so that the load on the trimmer head is equally
distributed about the trimmer head. For example, two slots and two
line segments, three slots and three line segments, or four slots
and two line segments would all result in a balance trimmer head,
but four slots with three line segments extending therefrom could
result in an unbalanced trimmer head.
[0086] FIG. 31C shows a module for use with the spool of FIG. 30
that is analogous that shown in FIG. 31B. However, the module 3170
of FIG. 31C has a central hole 3187 for receiving a fastener or the
chuck or arbor of the drive shaft of a trimmer machine. This use of
the module allows for the conversion of the spool from use with a
short drive shaft trimmer to a long drive shaft trimmer, the
typical difference between a curved drive shaft and a straight
drive shaft. FIG. 31D shows the module of FIG. 31B but having a
through hole 3187 through the center of the module.
[0087] FIGS. 32A & 32B shows a variation on the slot in the
central flange or central spoke of the spool for facilitating
winding of the line onto the spool. FIGS. 3 & 8 show typically
slots for directing the trimmer line into the line holding
chambers. The slot opening is roughly equal in diameter at the core
of the spool and at a point farthest from the core so that the slot
does not interfere with the trimmer line threading onto the core.
This also allows for easy removal of the line from the core when
the line needs to be replaced. However, when winding the trimmer
line onto the spool, the lack of any anchor (such as the
interference fit line receiving slots) means that as you begin to
wind the trimmer line onto the spool, the line can slip in one
direction or the other through the spool, resulting in one end of
the trimmer line extending further out of the spool than the other
end. This is important during winding and because the longer
trimmer line side will immediately need to be trimmed to balance
out the two sides of the line. This is typically done automatically
by a cutter on the trimmer head. Alternatively, if the lines are
wrapped in unequal numbers around the trimmer head, then one side
will "finish" before the other and the line will have to be
replaced prematurely.
[0088] The embodiment of FIG. 32A solves this issue by providing an
anchor for the trimmer line in the form of a V shaped or U shaped
slot (or other shape) forming a tapered slot for trapping the line
therein. As the trimmer line (not shown) begins its initial wrap
around the spool, the line will be forced inwardly along the slot
towards the core of the spool. As soon as the diameter/width of the
slot 3191 becomes smaller than the diameter of the trimmer line,
the line will be anchored in place. With the line thus anchored,
the line cannot pull in or out of the spool thereby preventing an
imbalance in the trimmer line from one side of the spool to the
other. When used with a line receiving slot such as that shown in
FIG. 31A, the slot provides an additional anchor to further secure
the line onto the spool. When the line needs to be replenished, the
line can just be pulled outwardly (through the eyelet for example)
to release the line from the slot. The dimension and material of
the slot should be chosen carefully to prevent the line from
weakening or breaking the line prematurely. FIG. 33 shows a cross
section of one such configuration of the slot of the spool of FIGS.
34 & 39. Note that in this embodiment, the slot does not taper
to a point, but has a minimum width at the end closer to the spool
that will ensure that the trimmer line is not pinched, severed or
sliced through. One skilled in the art would also recognize that
different slot sizes could be provided depending on the trimmer
line diameter being used with the spool. Preferably the minimum
width of the taper is more than 1/2 or 3/4 the width of the trimmer
line that is installed on the spool to prevent undue pinching of
the trimmer line by the anchor taper walls.
LX65
[0089] FIGS. 35-38 show an embodiment of a spool for a trimmer head
having an extended funnel 3762 for facilitating the entrance of a
trimmer line segment (not shown) into the spool channel 3724.
Trimmer line is typically made of nylon or similar plastic
materials. The material has elastic properties and can be
straightened or wound around the spool of a trimmer head. It also
is used because it has good wear characteristics. But in the short
term, the line can take on a "set" from the shape the material has
been stored in. For example, if the line is wound around a wide
core (i.e., around a large diameter object), the end of the line
may have a gentle curve to it. If the line is wound around a nail
or small diameter object, the end of the line may have a sharp
curve to it. Either of these may inhibit the line from easily
threading into the channel 3724 of a spool.
[0090] Previous spools such as that shown in the U.S. Pat. No.
6,263,580 to stark have used an introductory funnel (reference
numeral 8, FIG. 3b) to introduce a trimmer line to a spool.
However, the funnel does not direct the line into the channel so
much as it prevents the line from wandering too far from the
channel as the user continues to try to poke the line towards the
central hole. If the bend ("hook") of the line is more severe than
the angle of introduction of the funnel, then the line will not
point towards the channel, but will point towards the opposite side
of the funnel. It would be necessary to bend the extended length of
the line somewhat so that the tip of the line points into the
channel. The short funnel of Stark only helps if end of the line is
fairly straight so that the angle of the bend of the line plus the
angle of the funnel is not so great that the line points to the
opposite funnel wall instead of the entrance to the passageway
through the spool. Additionally, the sharp angle of the funnel wall
to the passageway can actually introduce additional bend in the
line making it harder to insert the line into the passageway.
[0091] By introducing an elongated funnel having gradually tapering
funnel walls, the trimmer line is more likely to be directed into
the passageway 3724 of the spool. Additionally, the funnel mouth
can be widened to accept the end of the line more easily, while
still effectively directing the end of the line into the
passageway. Or if the line gets caught as it is entering the funnel
because the line is too bent, further pressure on the line is more
likely to push the line into the passageway because of the gradual
taper of the funnel to the passageway. By making the funnel longer
than any anticipated problematic bend in the line, the funnel is
more likely to rapidly introduce the trimmer line into the
passageway. As shown in FIG. 36, a cross-sectional view of the
spool of 37, the funnel can extend from the flange (or spoke) to
the core or even inside the core of the spool for maximum funneling
effect. Preferably the tapered portion of the funnel proceeds more
than 1/3 or 1/2 of the diameter of the flange from the core of the
spool to the outer edge of the flange or spoke. More preferably the
funnel extends to within the outer wall of the spool core, and most
preferably extends to within the inner wall of the core of the
spool as shown in FIG. 36 so that it can readily receive a trimmer
line that is not perfectly straight.
[0092] FIG. 34 shows the combination of the extended funnel and the
anchor slot 3191 for anchoring the line as it is wrapped about the
spool. Please note that spool 3730 and spool 3710 may be formed as
one piece or separate pieces. However, because of the pressure of
the line winding in the space provide between the flange of the
spool and the top of the knob, it may be necessary when the knob
and spool are separate pieces to secure the knob to the spool by a
screw, bolt or other fastener. Preferably, the knob and spool are
held together by a quick release fastener (not shown) analogous to
the ones (reference 25,27 in FIG. 4) used to hold together the
trimmer head housing in some embodiments.
[0093] It should also be noted that the flange housing the funnel
in FIG. 34 has been reduced in diameter compared to the top flange.
This allows for a higher capacity in the storage area and more
importantly facilitates the efficient dispensing of the line from
the funnel to the line holding areas. Additionally, when the
funnels include a line anchor 3191, the smaller diameter allows for
more room to pull the line out of the slot and through the eyelet
when the line is no longer wrapped about the spool and the line is
feeding directly from the anchor to the eyelet.
[0094] While this invention has been described as having a
preferred design, it is understood that it is capable of further
modifications, uses and/or adaptations of the invention following
in general the principle of the invention and including such
departures from the present disclosure as come within the known or
customary practice in the art to which the invention pertains and
as may be applied to the central features hereinbefore set forth,
and fall within the scope of the invention and the limits of the
appended claims. It is therefore to be understood that the present
invention is not limited to the sole embodiment described above,
but encompasses any and all embodiments within the scope of the
following claims.
* * * * *