U.S. patent application number 14/584270 was filed with the patent office on 2016-06-30 for quick loading trimmer head.
The applicant listed for this patent is Husqvarna AB. Invention is credited to Stefan Kullberg.
Application Number | 20160183452 14/584270 |
Document ID | / |
Family ID | 55022416 |
Filed Date | 2016-06-30 |
United States Patent
Application |
20160183452 |
Kind Code |
A1 |
Kullberg; Stefan |
June 30, 2016 |
QUICK LOADING TRIMMER HEAD
Abstract
A hand-held cutting device including an elongated member
graspable along a portion thereof by an operator, a trimmer head
disposed at one end of the elongated member, and a power unit
operably coupled to the trimmer head to selectively cause rotation
of the trimmer head, wherein the trimmer head comprises a line
holding assembly to hold and selectively release the trimmer line
and a housing to house the line holding assembly, wherein the line
holding assembly includes a core having a first portion and a
second portion, and a spool configured to hold trimmer line that is
operably coupled to the core, and wherein the second portion of the
core is non-rotatably fixed to the first portion of the core when
the trimmer head is in an at-rest state, and is rotatable with
respect to the first position of the core when the trimmer head is
in an in-use state and rotating.
Inventors: |
Kullberg; Stefan;
(Jonkoping, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Husqvarna AB |
Husqvarna |
|
SE |
|
|
Family ID: |
55022416 |
Appl. No.: |
14/584270 |
Filed: |
December 29, 2014 |
Current U.S.
Class: |
30/276 ;
30/347 |
Current CPC
Class: |
A01D 34/416 20130101;
A01D 34/4161 20130101; A01D 34/4163 20130101; A01D 34/90 20130101;
A01D 34/4162 20130101 |
International
Class: |
A01D 34/416 20060101
A01D034/416; A01D 34/90 20060101 A01D034/90 |
Claims
1. A hand-held cutting device (10) comprising: an elongated member
(45) graspable along a portion thereof by an operator; a trimmer
head (25) disposed at one end of the elongated member (45) and
configured to be rotatable to perform a cutting function using
trimmer line (70) held at a portion of the trimmer head (25); and a
power unit operably coupled to the trimmer head (25) to selectively
cause rotation of the trimmer head (25) via turning a shaft,
wherein the trimmer head (25) comprises: a line holding assembly
(110, 310) to hold and selectively release the trimmer line (70);
and a housing including a first housing portion (100) and a second
housing portion (120) operably coupled to the first housing portion
(100) to house the line holding assembly (110, 310), wherein the
line holding assembly (110, 310) includes a core (140, 140', 340)
having a first portion (342, 442) and a second portion (350, 450),
and a spool (130, 130') configured to hold the trimmer line (70)
that is operably coupled to the core (140, 140', 340), and wherein
the second portion (350, 450) of the core (140, 140', 340) extends
outwardly from the housing and is non-rotatably fixed to the first
portion (342, 442) of the core (140, 140', 340) when the trimmer
head (25) is in an at-rest state, and is rotatable with respect to
the first position (342, 442) of the core (140, 140', 340) when the
trimmer head is in an in-use state and rotating.
2. The device (10) of claim 1, wherein the line holding assembly
(110, 310) is configured such that rotational movement of the core
(140, 140', 340) causes corresponding movement of the spool (130,
130'), but movement of the core (140, 140', 340) in an axial
direction (124) does not cause corresponding movement of the spool
(130, 130').
3. The device (10) of claim 1, wherein the first housing portion
(100) is operably coupled to the shaft and turns responsive to
operation of the power unit.
4. The device (10) of claim 1, wherein the core (140, 140', 340)
comprises a line channel (390) extending through the core (140,
140', 340) in a radial direction to receive the trimmer line (70)
fed therethrough.
5. The device (10) of claim 1, further comprising a radial bearing
(360) operably disposed between the first portion (342, 442) of the
core (140, 140', 340) and the second portion (350, 450) of the core
(140, 140', 340).
6. The device (10) of claim 1, wherein the core (140, 140', 340) is
movable in the axial direction (124) to release trimmer line (70)
from the spool (130, 130'), but the spool (130, 130') does not
substantially move in the axial direction (124) responsive to
movement of the core (140, 140', 340) in the axial direction
(124).
7. The device (10) of claim 1, wherein the first portion (342, 442)
of the core (140, 140', 340) comprises a locking projection (372)
that is radially movable between a first radially outward position
and a second radially inward position, and the second portion (350,
450) of the core (140, 140', 340) defines a lock recess (352)
configured to receive the locking projection (372) when it is
disposed in its first position, thereby non-rotatably fixing the
second portion (350, 450) of the core (140, 140', 340) to the first
portion (342, 442) of the core (140, 140', 340).
8. The device (10) of claim 7, wherein the locking projection (372)
depends radially outward from a first portion of a body (378) of a
locking slide (370) that is disposed opposite a second portion of
body (378) from which a counterweight (376) depends radially
outwardly.
9. The device (10) of claim 8, further comprising a spring (374)
that exerts a radially outward biasing force on locking projection
(372).
10. The device (10) of claim 7, wherein the locking projection is
disposed on a first end of a locking lever (470) that is pivotally
secured to the first portion (342, 442) of the core (140, 140',
340).
11. The device (10) of claim 10, wherein the locking lever (470)
comprises a counterweight disposed on a second end of the locking
lever (470) opposite the locking projection (372).
12. The device (10) of claim 1, wherein the core (140, 140', 340)
further comprises a third portion (195') that is non-rotatably
fixed to the first portion (342, 442) of the core (140, 140',
340).
13. The device (10) of claim 12, wherein the spool (130, 130') is
non-rotatably fixed to the third portion (195') of the core (140,
140', 340).
14. A hand-held cutting device (10) comprising: an elongated member
(45) graspable along a portion thereof by an operator; a trimmer
head (25) disposed at one end of the elongated member (45) and
configured to be rotatable to perform a cutting function using
trimmer line (70) held at a portion of the trimmer head (25); and a
power unit operably coupled to the trimmer head (25) to selectively
cause rotation of the trimmer head (25) via turning a shaft,
wherein the trimmer head (25) comprises: a line holding assembly
(110, 310) to hold and selectively release the trimmer line (70);
and a housing including a first housing portion (100) and a second
housing portion (120) operably coupled to the first housing portion
(100) to house the line holding assembly (110, 310), wherein the
line holding assembly (110, 310) includes a core (140, 140', 340)
having a first portion (342, 442) and a second portion (350, 450),
a radial bearing (360) operably disposed between the first portion
(342, 442) of the core (140, 140', 340) and the second portion
(350, 450) of the core (140, 140', 340), and a spool (130, 130')
configured to hold the trimmer line (70) that is operably coupled
to the core (140, 140', 340).
15. The device (10) of claim 14, wherein the line holding assembly
(110, 310) is configured such that rotational movement of the core
(140, 140', 340) causes corresponding movement of the spool (130,
130'), but movement of the core (140, 140', 340) in an axial
direction (124) does not cause corresponding movement of the spool
(130, 130').
16. The device (10) of claim 14, wherein the second portion (350,
450) of the core (140, 140', 340) extends outwardly from the
housing and is non-rotatably fixed to the first portion (342, 442)
of the core (140, 140', 340) when the trimmer head (25) is in an
at-rest state, and is rotatable with respect to the first position
(342, 442) of the core (140, 140', 340) when the trimmer head is in
an in-use state and rotating.
17. The device (10) of claim 14, wherein the core (140, 140', 340)
comprises a line channel (390) extending through the core (140,
140', 340) in a radial direction to receive the trimmer line (70)
fed therethrough.
18. The device (10) of claim 14, wherein the spool (130, 130') is
non-rotatably fixed to a third portion (195') of the core (140,
140', 340).
19. The device (10) of claim 14, wherein the first portion
(342,442) of the core (140, 140', 340) comprises a locking
projection (372) that is radially movable between a first radially
outward position and a second radially inward position, and the
second portion (350, 450) of the core (140, 140', 340) defines a
lock recess (352) configured to receive the locking projection
(372) when it is disposed in its first position, thereby
non-rotatably fixing the second portion (350, 450) of the core
(140, 140', 340) to the first portion (342, 442) of the core (140,
140', 340).
20. The device (10) of claim 19, wherein the locking projection
(372) depends radially outward from a first portion of a body (378)
of a locking slide (370) that is disposed opposite a second portion
of body (378) from which a counterweight (376) depends radially
outwardly.
21. The device (10) of claim 20, further comprising a spring (374)
that exerts a radially outward biasing force on locking projection
(372).
22. The device (10) of claim 19, wherein the locking projection is
disposed on a first end of a locking lever (470) that is pivotally
secured to the first portion (342, 442) of the core (140, 140',
340).
23. The device (10) of claim 22, wherein the locking lever (470)
comprises a counterweight disposed on a second end of the locking
lever (470) opposite the locking projection (372).
24. A trimmer head (25) for a hand-held cutting device (10)
comprises: a line holding assembly (110, 310) to hold and
selectively release a trimmer line (70); the line holding assembly
(110, 310) having: a housing including a first housing portion
(100) and a second housing portion (120) operably coupled to the
first housing portion (100) to enclose the line holding assembly
(110, 310); the line holding assembly (110, 310) includes a core
(140, 140', 340) having a first portion (342, 442) and a second
portion (350, 450) and a spool (130, 130') configured to hold the
trimmer line (70) that is operably coupled to the core (140, 140',
340), and wherein the second portion (350, 450) of the core (140,
140', 340) extends outwardly from the housing (120), wherein the
second portion (350, 450) of the core (140, 140', 340) is
non-rotatably fixed to the first portion (342, 442) of the core
(140, 140', 340) when the trimmer head (25) is in an at-rest state,
and is rotatable with respect to the first position (342, 442) of
the core (140, 140', 340) when the trimmer head is in an in-use
state and rotating.
25. The trimmer head (25) of claim 24, further comprising a radial
bearing (360) operably disposed between the first portion (342,
442) of the core (140, 140', 340) and the second portion (350, 450)
of the core (340).
26. The trimmer head (25) of claim 24, wherein the spool (130,
130') is non-rotatably fixed to the first portion (342, 442) of the
core (140, 140', 340).
27. The trimmer head (25) of claim 25, wherein the first portion
(342, 442) of the core (140, 140', 340) comprises a locking
projection (372) that is radially movable between a first radially
outward position and a second radially inward position, and the
second portion (350, 450) of the core (140, 140', 340) defines a
lock recess (352) configured to receive the locking projection
(372) when it is disposed in its first position, thereby
non-rotatably fixing the second portion (350, 450) of the core
(140, 140', 340) to the first portion (342, 442) of the core (140,
140', 340).
28. The trimmer head (25) of claim 27, wherein the locking
projection (372) depends radially outward from a first portion of a
body (378) of a locking slide (370) that is disposed opposite a
second portion of body (378) from which a counterweight (376)
depends radially outwardly.
29. The trimmer head (25) of claim 28, further comprising a spring
(374) that exerts a radially outward biasing force on locking
projection (372).
30. The trimmer head (25) of claim 27, wherein the locking
projection is disposed on a first end of a locking lever (470) that
is pivotally secured to the first portion (342, 442) of the core
(140, 140', 340).
Description
TECHNICAL FIELD
[0001] Example embodiments generally relate to an outdoor power
device that employ trimmer line and, more particularly, relate to a
mechanism for providing relatively easy loading of trimmer
line.
BACKGROUND
[0002] Handheld outdoor power devices such as trimmers, blowers,
chainsaws, and/or the like, are often used to perform tasks
relating to yard/grounds maintenance or even commercial resource
harvesting activities that require them to be mobile. Although
there are several options for powering such devices, including
combustion engines, corded electric motors, or battery powered
electric motors, each option may be viewed as having advantages in
certain environments and for certain users.
[0003] Some trimming devices employ a trimmer line and are referred
to as string trimmers. Alternatively, such devices may be known as
edge trimmers, line trimmers, weed whips and/or the like. The
trimmer line, which may be a monofilament line, is quite effective
at cutting when rotated at high speed. Such a trimmer line is
extended and held somewhat rigid by centrifugal forces while being
rotated. In some cases, the trimmer line is wound upon a reel or
spool and the trimmer line can be released by bumping the trimmer
head, specifically its line release knob, on the ground during
operation. However, it has been common for such devices to be
somewhat difficult to load trimmer line into. Additionally, the
method of releasing trimmer line by bumping the knob of the trimmer
head on the ground during operation can lead to excessive wear of
the knob and various portions of the trimmer head. Thus, operators
may find it frustrating and/or difficult to replace the trimmer
line and/or portions of the trimmer head, such as the knob, too
often. Accordingly, the user experience associated with employing
such devices may suffer.
BRIEF SUMMARY OF SOME EXAMPLES
[0004] Some example embodiments may therefore provide a trimmer
device that can accommodate a structure that is relatively quick
and easy to load with trimmer line. The structure may provide a
spool that is substantially fixed to prevent any substantial
movement in the axial (or vertical) direction, but can move in the
rotational direction responsive to operation of a power unit. As
such, for example, the spool may be mated with a core that can be
"bumped" to release line from the spool in a manner that permits
the core to move in the axial (or vertical) direction, while the
spool releases line but does not substantially move in the axial
(or vertical direction). The structure may provide a line channel
through the core that is much longer than the portion of the spool
through which line is fed in the radial direction.
[0005] In one example embodiment, a trimmer head for a hand-held
cutting device is provided. The trimmer head may include a first
housing portion, a line holding assembly to hold and selectively
release trimmer line, and a second housing portion operably coupled
to the first housing portion to house the line holding assembly.
The line holding assembly may include a spool configured to hold
the trimmer line and a core operably coupled to the spool. The line
holding assembly may be configured such that rotational movement of
the core causes corresponding movement of the spool, but movement
of the core in an axial direction does not cause corresponding
movement of the spool.
[0006] In another example embodiment, a hand-held cutting device is
provided. The device may include an elongated member graspable
along a portion thereof by an operator, a trimmer head disposed at
one end of the elongated member and configured to be rotatable to
perform a cutting function using trimmer line held at a portion of
the trimmer head, and a power unit operably coupled to the trimmer
head to selectively cause rotation of the trimmer head via turning
a shaft. The trimmer head may include a first housing portion, a
line holding assembly to hold and selectively release the trimmer
line, and a second housing portion operably coupled to the first
housing portion to house the line holding assembly. The line
holding assembly may include a spool configured to hold the trimmer
line and a core operably coupled to the spool. The line holding
assembly may be configured such that rotational movement of the
core causes corresponding movement of the spool, but movement of
the core in an axial direction does not cause corresponding
movement of the spool. As well, the line holding assembly may be
configured such that a portion that comes into contact with the
ground during operation is free to rotate with respect to the
remainder of the line holding assembly. Specifically, a line
release knob may be free to rotate during cutting operations,
thereby minimizing wear on the knob and increasing its functional
lifetime.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0007] Having thus described the invention in general terms,
reference will now be made to the accompanying drawings, which are
not necessarily drawn to scale, and wherein:
[0008] FIG. 1 illustrates a perspective view of an electric powered
trimmer that may be configured in accordance with an example
embodiment;
[0009] FIG. 2A illustrates an exploded perspective view of a
trimmer head configured in accordance with an example embodiment
from above;
[0010] FIG. 2B illustrates an exploded perspective view of a
trimmer head configured in accordance with an example embodiment
from below;
[0011] FIG. 3A illustrates a side view of the trimmer head in
accordance with an example embodiment;
[0012] FIG. 3B illustrates a cross section view of the trimmer head
in accordance with an example embodiment;
[0013] FIG. 4A illustrates a cross section view along a line that
bisects a line channel with the trimmer head in a normal position
in accordance with an example embodiment;
[0014] FIG. 4B illustrates the cross section view of FIG. 4A with
the trimmer head in a "bumped" condition in accordance with an
example embodiment;
[0015] FIG. 5 illustrates a perspective view of a spool in
accordance with an example embodiment;
[0016] FIG. 6 illustrates a perspective view of a core in
accordance with an example embodiment;
[0017] FIG. 7 illustrates an exploded perspective view of an
alternative line holding assembly from a bottom perspective in
accordance with an example embodiment;
[0018] FIG. 8 illustrates an exploded perspective view of the
alternative line holding assembly from a top perspective in
accordance with an example embodiment;
[0019] FIG. 9 illustrates an exploded side view of the alternative
line holding assembly in accordance with an example embodiment;
[0020] FIG. 10 illustrates a perspective view of the alternative
line holding assembly in an assembled state in accordance with an
example embodiment;
[0021] FIG. 11 illustrates a side view of the alternative line
holding assembly in an assembled state in accordance with an
example embodiment;
[0022] FIG. 12 illustrates a cross section view of the alternative
line holding assembly according to an example embodiment;
[0023] FIG. 13 illustrates a bottom perspective view of a trimmer
head including an alternative line holding assembly in accordance
with an example embodiment;
[0024] FIG. 14 illustrates a cross section view of the trimmer head
in FIG. 13;
[0025] FIG. 15 illustrates an assembled perspective view of a
portion of the alternative line holding assembly in accordance with
an example embodiment;
[0026] FIG. 16 illustrates an exploded perspective view of the
portion of the alternative line holding assembly shown in FIG.
16;
[0027] FIG. 17 illustrates a perspective view of a portion of an
alternative line holding assembly in an assembled state accordance
with an example embodiment;
[0028] FIG. 18 illustrates an exploded perspective view of the
portion of the alternative line holding assembly shown in FIG.
17;
[0029] FIG. 19A illustrates a cross section view of the portion of
the alternative line holding assembly shown in FIG. 17, in the
at-rest position; and
[0030] FIG. 19B illustrates the cross section view of the portion
of the alternative line holding assembly shown in FIG. 17, in the
in-use position.
DETAILED DESCRIPTION
[0031] Some example embodiments now will be described more fully
hereinafter with reference to the accompanying drawings, in which
some, but not all example embodiments are shown. Indeed, the
examples described and pictured herein should not be construed as
being limiting as to the scope, applicability or configuration of
the present disclosure. Rather, these example embodiments are
provided so that this disclosure will satisfy applicable legal
requirements. Like reference numerals refer to like elements
throughout. Furthermore, as used herein, the term "or" is to be
interpreted as a logical operator that results in true whenever one
or more of its operands are true. As used herein, operable coupling
should be understood to relate to direct or indirect connection
that, in either case, enables functional interconnection of
components that are operably coupled to each other. One of skill in
the art will appreciate the normal position in which devices of
example embodiments are held for operation and that the working
assembly represents the front of such devices. All other
directional references should be understood in this general
context.
[0032] Some example embodiments described herein provide a line
holding assembly that can be easily molded and assembled, and that
allows an operator to quickly and easily load trimmer line onto a
trimmer head. In particular, some example embodiments provide a
two-piece line holding assembly in which the spool and core are
separate pieces to permit easy construction. In some cases, to
further increase the ease of manufacturing, even the core may be
split into two pieces. The parts may then be assembled, and the
resultant assembly may permit movement of the core in the axial
direction (e.g., to let out more line), but may prevent movement of
the spool in the axial direction. Meanwhile, the core and spool may
move together for rotational movements.
[0033] Referring to the drawings, FIG. 1 shows an electric powered
trimmer 10 that may be configured in accordance with an example
embodiment. However, it should be appreciated that the trimmer 10
is merely one example of an electric powered, outdoor power device
that may be configured in accordance with an example embodiment.
However, example embodiments could alternatively be employed in
connection with corded versions of various electric powered,
outdoor power devices. Moreover, in some cases, example embodiments
could also be practiced in connection with combustion engines that
are configured to turn an output shaft. Thus, although an example
embodiment will be described hereinafter with specific reference to
the battery powered trimmer 10 of FIG. 1, the applicability of
alternative embodiments relative to other types of devices should
be well understood.
[0034] As shown in FIG. 1, the trimmer 10 may include a working
implement or working assembly 20, which in this example includes a
rotatable trimmer head 25. The working assembly 20 may further
include a motor (e.g., an electric motor) disposed in a housing 28
of the working assembly 20. However, for gas powered embodiments
and for some electrically powered embodiments, the motor is often
disposed remotely with respect to the trimmer head 25, and power is
transferred to the trimmer head 25 via couplings provided in the
housing 28. The motor of the trimmer 10 may be powered, according
to this example, by a battery pack 30. The battery pack 30 is
received into a battery compartment of the trimmer 10. It should be
appreciated that the battery pack 30 and/or motor of this example
form a power unit that can turn the working assembly 20. However,
in other examples, the power unit may include a combustion engine
or other suitable power source.
[0035] The battery compartment may be a recess or cavity formed in
a casing 40 of the trimmer 10 disposed at one end of an elongated
member 45 that may further include the working assembly 20 at an
opposite end thereof. The elongated member 45 may be a hollow tube,
pipe, rod or other such member that may be straight or curved in
different embodiments. The elongated member 45 may provide operable
communication between the working assembly 20 and the battery pack
30 so that the battery pack 30 can power the working assembly 20.
In some embodiments, the casing 40 may be formed from one or more
plastic or other rigid components that may be molded to have a
desired shape. The casing 40 may substantially enclose the battery
compartment, control circuitry and/or other components associated
with powering and/or controlling the operation of the trimmer 10.
However, it should also be appreciated that the battery pack of
some alternative embodiments may be housed within a backpack that
may be worn on the operator's back. In such an example, the battery
pack may be connected to the trimmer 10 via a cord or other
adaptor.
[0036] In an example embodiment, the trimmer 10 may include a rear
handle 50 and a front handle 60. The rear handle 50 may be disposed
in-line with the elongated member 45 proximate to the casing 40,
while the front handle 60 may be disposed between the casing 40 and
the working assembly 20 at an intermediate portion of the elongated
member 45. An operator of the trimmer 10 may use one hand to hold
the front handle 60 and the other hand to hold the rear handle 50
while operating the trimmer 10. In some embodiments, the rear
handle 50 may include a trigger 52 or other control mechanism for
engaging operation of the motor to power the working assembly
20.
[0037] Although FIG. 1 shows the front handle 60 being positioned
forward of the rear handle 50 along the elongated member 45, it
should also be appreciated that other arrangements for holding and
operating the trimmer 10 may be provided. For example, in some
cases, a "handlebar" embodiment may be provided in which the front
and rear handles 60/50 are replaced by a single handle assembly
attached to the elongated member 45 where both handles on the
handle assembly are substantially equidistant from the working
assembly 20 and disposed spaced apart from the elongated member 45
on opposites sides thereof on a handlebar assembly. Other
arrangements are also possible.
[0038] The trimmer 10 may further employ a trim shield 65 that is
configured to prevent cut materials and/or debris from coming back
at the operator. The operator may actuate the trigger 52 to power
the working assembly and turn the trimmer head 25. The trimmer head
25 may include trimmer line 70 that may extend outwardly (e.g., in
a radial direction relative to a shaft forming an axis about which
the trimmer head 25 rotates) from the trimmer head 25 to cut
vegetation encountered thereby. The trim shield 65 may employ at
least one knife element (not shown) to cut the trimmer line 70 to a
length slightly less than the distance from the external periphery
of the trimmer head 25 to the internal periphery of the trim shield
65 responsive to rotation of the trimmer head 25.
[0039] In an example embodiment, the motor may be a DC motor or a
brushless DC motor (BLDC) that is powered by the battery pack 30.
The motor may be configured to turn in either the clockwise or
counterclockwise direction when a power switch 72 is powered on. In
the example of FIG. 1, the power switch 72 may be provided at a
control panel or control assembly 80 that may be positioned
proximate to the rear handle 50. However, the control assembly 80
could be positioned at any of a number of other locations on the
trimmer 10 in alternative embodiments. Moreover, it should be
appreciated that gasoline powered embodiments may replace the
trigger 52 with a throttle and may replace the battery pack with a
gasoline engine. The general structure, however, of even such
gasoline powered embodiments may generally be similar and, as
indicated above, the power unit may therefore be electric or gas
powered.
[0040] The rotation of the trimmer head 25 may cause the trimmer
line 70 (which may be monofilament line) to stiffen extensively
based on centrifugal forces applied to the trimmer line 70 during
rotation. The faster the rotation, the stiffer the trimmer line 70
generally becomes. The trimmer line 70 can therefore make a good
cutting tool for the cutting or trimming of most vegetation that is
not substantially woody. However, it is typically inevitable that
the trimmer line 70 will be worn during use. The wearing forces
acting on the trimmer line 70 may cause the line to break, abrade
or otherwise shorten in length over time. To re-extend the trimmer
line 70 to full length, the trimmer head 25 may be "bumped" on the
ground to release more trimmer line 70 (and cut it to length, if
appropriate).
[0041] To provide sufficient additional trimmer line 70 to allow
the "bump" operation to release line, the trimmer head 25 may be
provided with a trimmer line spool upon which extra trimmer line 70
may be wound. However, even this spool would eventually run out of
trimmer line 70 over time and need replenishment. In the past, the
winding of more trimmer line 70 onto the spool has required some
level of disassembly of the trimmer head 25. This disassembly and
winding of trimmer line 70 can be cumbersome, and may be difficult
to accomplish in a quick and easy manner. Accordingly, some example
embodiments have been provided to improve the capability of the
operator to easily and quickly replenish trimmer line 70 onto the
trimmer head 25.
[0042] FIG. 2, which includes FIGS. 2A and 2B illustrates an
exploded perspective view of the trimmer head 25 of an example
embodiment from above (FIG. 2A) and below (FIG. 2B) perspectives.
FIG. 3, which includes FIGS. 3A and 3B, illustrates a side view and
cross section view of the trimmer head 25 of an example embodiment.
The orientation of the trimmer head 25 in FIGS. 3A and 3B is such
that the observer is looking into a line channel 90 through which
trimmer line is passed prior to being wound onto a spool 130 of the
device. FIG. 4, which includes FIGS. 4A and 4B, illustrates cross
section views taking along a line that bisects the line channel 90.
FIG. 4A shows the trimmer head 25 in a normal position and FIG. 4B
shows the trimmer head 25 in a "bumped" condition. FIG. 5
illustrates a perspective view of the spool 130 in accordance with
an example embodiment, and FIG. 6 illustrates a perspective view of
a core 140 in accordance with an example embodiment.
[0043] As shown in FIGS. 2-6, the trimmer head 25 may include a
first housing portion 100, a line holding assembly 110 to hold and
selectively release trimmer line (not shown in FIG. 2-6), and a
second housing portion 120. The second housing portion 120 may be
operably coupled to the first housing portion 100 to house the line
holding assembly 110. In an example embodiment, the first and
second housing portions 100 and 120 may be snap fit together,
fastened with one or more screws or other fastening members, and/or
latched together. In the example of FIG. 2, the first housing
portion 100 may include tabs 102 that snap fit into corresponding
tab receivers 122 of the second housing portion 120. Generally
speaking, the first housing portion 100 may be disposed on top of
the second housing portion 120, which may be disposed on the bottom
of the assembly. The terms top and bottom in this context are
relative to the normal way the trimmer 10 is held with the bottom
being closest to the ground.
[0044] The line holding assembly may include the spool 130
configured to hold the trimmer line and the core 140 operably
coupled to the spool 130 such that rotational movement of the core
140 causes corresponding movement of the spool 130, but movement of
the core in an axial direction (indicated by arrow 124) does not
cause corresponding movement of the spool 130. The first housing
100 may include a coupling portion 104 that may be operably coupled
to a shaft that is turned by the power unit. However, in some
embodiments, the shaft may be operably coupled to the core 140. In
either case, the power unit may ultimately cause the core 140 to
turn and, relative to rotational movement, the core 140 may then
turn the spool 130 as well.
[0045] A biasing element (e.g., spring 150) may be provided between
the first housing portion 100 and the core 140 to bias the core 140
downward in the axial direction. When a "bump" operation is
conducted by tapping the core 140 on the ground, the core 140 may
move upward against the force of the spring 150 to enable the
centrifugal force on the trimmer line during the rotation of the
spool 130 relative to the second housing portion 120 to cause the
spool 130 to release trimmer line. In particular, the second
housing portion 120 may include one or more detents 126 that may
lie in registration with one or more corresponding slide
projections 142 on the core 140. Meanwhile, the first housing
portion 100 may include similar detents 106 that may lie in
registration with slide projections 143 disposed facing upwardly
from the external periphery of the core 140. However, it should be
appreciated that in alternative structures, the locations of the
detents (106 and 126) and slide projections (142 and 143) could be
reversed. The slide projections 142 may typically engage the
detents 126 to prevent movement of the core 140 relative to the
second housing portion 120 while the spring 150 pushes the slide
projections 142 and the detents 126 into contact with each other.
When the operator taps the core 140 on the ground, the force of the
spring 150 may be overcome momentarily to enable the slide
projections 142 to disengage the detents 126 and rotate the core
140 (and spool 130) relative to the second housing portion 120 to
allow trimmer line to be released from the spool 130 through
orifices 128 on the second housing portion 120. Meanwhile, the
slide projections 143 may catch the next set of detents 106 to
limit the amount of relative motion between the housings and the
core 140.
[0046] As can be seen in FIG. 3B, the first housing portion 100 may
include spool stays 105 disposed above the spool 130. Similarly,
the second housing portion 120 may include spool stays 125 to
combine with the spool stays 105 on the first housing portion 100
to limit movement of the spool 130 in the axial direction.
Meanwhile, the core 140 may fit inside the spool 130 and have room
to move in the axial direction within a core channel 155 that is
shown to have room at the top to accommodate upward movement of the
core 140 in the axial direction.
[0047] Referring specifically to FIGS. 4A and 4B, the line channel
90 may extend through the core 140 in a radial direction to receive
the trimmer line fed therethrough. Although it should be
appreciated that in some embodiments, the line channel 90 may be
part of the spool 130. Regardless, in some cases, the line channel
90 may include at least one bend along a length thereof. The bend
may extend in the axial direction away from the spring 150. In some
cases, the line channel 90 may have a same width in the axial
direction over an entirety of the line channel 90. However, in some
embodiments, the line channel 90 has a first width in the axial
direction over a mid portion of the line channel 90, and the line
channel may expand to a second width in the axial direction
proximate to each of the opposing ends of the line channel 90. As
shown in FIG. 4, the core 140 may have additional hollow channels
144 that serve to reduce the overall weight of the core 140. When
the embodiment of FIG. 4A is "bumped", the core channel 155 enables
the core 140 to move upward to reduce the free volume at the top of
the core channel 155 as shown in FIG. 4B.
[0048] In some embodiments, the spool 130 may include a first
flange 132 and a second flange 134 that extend in respective planes
that are substantially parallel to each other and substantially
perpendicular to the axial direction. The trimmer line extending
out from opposing ends of the line channel 90 may be fed through
channel portions 136 disposed to pass through the spool 130 in the
radial direction. The channel portions 136 may terminate at the
internal periphery of the spool 130 at respective line orifices
188. The line orifices 188 may be aligned in registration with the
ends of the line channel 90. Trimmer line fed through the line
channel 90, the line orifices 188 and the channel portions 136 may
then be wound onto the spool between the first and second flanges
132 and 134 responsive to rotation of the core 140 about the axis
of the core by the operator. For example, the core 140 may have
grip portions to allow the operator to grasp the grip portions and
manually turn the core 140 (and therefore also turn the spool 130)
to wind trimmer line onto the spool 130. The spool 130 of some
embodiments may also include a third flange 138 disposed between
the first and second flanges 132 and 134 to divide the spool 130
into a top line receiving portion and a bottom line receiving
portion. In such an example, the top line receiving portion may
receive the trimmer line exiting one end of the line channel 90 and
the bottom line receiving portion may receive trimmer line exiting
the other end of the line channel 90.
[0049] As mentioned above, the core 140 may be movable in the axial
direction to release trimmer line from the spool 130, but the spool
130 does not substantially move in the axial direction when the
core 140 moves in the axial direction. Thus, although the spool 130
is affixed to the core 140 to move in registration therewith
responsive to rotational movement of the core 140, the spool 130 is
enabled to slide over the surface of the core 140 when the core 140
moves in the axial direction. The channel portions 136 of the spool
130 that are proximate to the ends of the line channel 90 (i.e., at
location of the line orifices 188) may be wider to ensure that some
portion of the channel portions 136 stays in alignment with the
line channel 90 even when the core 140 moves axially (e.g.,
responsive to a bump operation).
[0050] To maintain the spool 130 and core 140 in registration with
each other for rotational movement, while still permitting relative
motion between the two in the axial direction, the spool 130 may be
annularly shaped to define an inner periphery that is slightly
larger than the external periphery of the core 140 (which may be
generally cylindrical in shape at the area of overlap with the
spool 130). The spool 130 may therefore slidably engage the outer
periphery of a portion of the core 140 to permit relative movement
of the core 140 in the axial direction. However, it should be
appreciated that the spool 130 and the core 140 could alternatively
have other shapes that are substantially matched to permit slidable
engagement in the axial direction. For example, hexagonal,
octagonal or other shapes may be employed. In an example
embodiment, the inner periphery of the spool 130 may be provided
with a vertical protrusion 180. Meanwhile, the external periphery
of the core 140 may be provided with a vertical channel 185 that is
slightly larger in size (but substantially similarly shaped)
compared to the vertical protrusion 180. When the core 140 is
bumped to move in the axial direction, the vertical protrusion 180
may be configured to ride in the vertical channel 185.
[0051] In some embodiments, a length of the line channel LC may be
longer than a combined length of extension of the channel portions
136 on each respective opposing side of the spool. Thus, the length
of each channel portion 136 may be a length CP and LC may be
greater than 2.times.CP.
[0052] In some embodiments, the core 140, the spool 130, and/or the
first and second housing portions 100 and 120 may be made of hard
plastic or some other rigid material. Thus, in some cases, the core
140, the spool 130, and/or the first and second housing portions
100 and 120 may be molded components. However, to facilitate easier
formation of the line channel 90, the core may sometimes be formed
in two parts. Thus, for example, a core base 190 may be molded as
one piece and a core insert 195 may be separately molded to fit
into the core base 190 to define the line channel 90. In
particular, the core insert 195 may form top portion of the line
channel 90 and may be separable from the core base 190, which may
form the bottom portion of the line channel 90 as shown in FIG.
3B.
[0053] The specific structures shown in FIGS. 2-6 illustrate one
example embodiment. However, other specific structures may be used
to embody the same inventive concepts. In this regard, FIGS. 7-12
illustrate an alternative core and/or spool structure that could be
employed in some embodiments. As such, the example of FIGS. 7-12
represents an alternative line holding assembly 110'. FIGS. 7 and 8
represent exploded perspective views of the line holding assembly
110' from opposing perspectives and FIG. 9 illustrates an exploded
side view of the line holding assembly 110'. FIG. 10 illustrates a
perspective view of the line holding assembly 110' in an assembled
state, and FIGS. 11 and 12 illustrate an assembled state, side view
and cross section view, respectively.
[0054] The line holding assembly 110' may generally be inserted
into the first housing portion 100 and second housing portion 120
described above, and the operation of the line holding assembly
110' may be substantially similar to the operations described
above. However, the line holding assembly 110' of this example may
include a two-piece core 140'. If desired, the line holding
assembly 110' may employ a spool 130' having only two flanges (and
therefore only one line receiving portion). The spool 130' may
still include a line orifice 188' formed in a vertical protrusion
180' on the internal periphery of the spool 130' Moreover, the
vertical protrusion 180' may be configured to ride in a vertical
channel 185' on a portion of the core 140'.
[0055] The line holding assembly 110' may also include a line
channel 90'. However, the line channel 90' may be formed by a top
part (i.e., core insert 195') that defines sidewalls 250 and a top
for the line channel 90' and a bottom part (i.e., core base 190')
that defines a base 255 of the line channel 90'. The core insert
195' may further include protrusions 260 that may be configured to
snap into corresponding receivers 265 disposed in the core base
190'. In some cases, the external periphery of the core insert 195'
may further include one or more stabilizer channels 270 that may be
configured to mate with corresponding one or more stabilizer
protrusions 275 at an internal periphery of the spool 130'. The
mating of the stabilizer channels and protrusions may prevent the
spool from wobbling relative to the core 140'.
[0056] The specific structures shown in FIGS. 2 through 12
illustrate two example embodiments. In this regard, FIGS. 13
through 16 illustrate an alternative core and/or spool structure
that could be employed in some embodiment. As such, the example of
FIGS. 13 through 16 represents an alternative line holding assembly
310. FIG. 13 illustrates a perspective view of a trimmer head
including the alternative line holding assembly 310, and FIG. 14 is
a cross-sectional view of the trimmer head and line holding
assembly 310 shown in FIG. 13. FIG. 15 illustrates a top
perspective view of the assembled core base 342 of a core 340 of
the line holder assembly 310, and FIG. 16 illustrates an exploded
perspective view of the core base 342 as shown in FIG. 15.
[0057] The line holding assembly 310 may generally be inserted into
the first housing portion 100 and second housing portion 120
described above, and the operation of the line holding assembly 310
may be substantially similar to the operations described above.
However, the line holding assembly 310 of this example may include
a multi-piece core including a core base 342 and a core insert
195', the core insert 195' being similar to that previously
discussed with regard to the embodiment shown in FIGS. 7 through
12. As shown, the line holding assembly 310 employs a spool 130 as
previously discussed with regard to the embodiment of FIGS. 2
through 6, but in alternate embodiments may include a spool 130' as
previously discussed with regard to the embodiment shown in FIGS. 7
through 12.
[0058] The line holding assembly 310 also includes a line channel
390. The line channel 390 may be formed by core insert 195' that
defines the side walls and top of the line channel 390 and a
channel base 349 of the line channel 390 that is secured to the
core base 342 by fasteners (not shown) and extends upwardly
therefrom. As best seen in FIGS. 15 and 16, the core base 342
includes a base plate 344 defining a central aperture 346, a
locking aperture 348 defined in its sidewall, and a pair of
receivers 265 that are configured to receive protrusions 260 (FIG.
8) that depend downwardly from core insert 195' in a snap fit.
[0059] A "bumper knob" 350 is selectively rotatably secured to core
base 342 by threaded fastener 380. A radial bearing 360 including
an inner race 362, an outer race 364 and a plurality of rollers 366
is disposed between core base 342 and knob 350 to facilitate
rotation of knob 350 relative to core base 342 while minimizing
potential wear. Specifically, the outer race 364 of the radial
bearing 360 is received adjacent the sidewall of the central
aperture 346 whereas the inner race 362 is received adjacent the
sidewall of an axial projection 354 that depends upwardly from the
inner surface of the knob 350. A washer 382 that has a diameter
that is greater than the inner diameter of the inner race 362 of
the radial bearing 360 is disposed between a head of the threaded
fastener 380 and the radial bearing 360, thereby securing the knob
350 to the bottom surface of the base plate 344. Note, radial
bearing 360 is also configured to reduce friction in the axial
direction between the base plate 344 and the knob 350.
[0060] A locking slide 370 including a locking projection 372 and a
counterweight 376 is slidably disposed within the base plate 344 of
the core base 342. As shown, the locking projection 372 and the
counterweight 376 of the locking slide 370 extend radially
outwardly from opposing portions of the substantially circular body
378 of the locking slide 370. The locking slide 370 is constrained
within the base plate 344 of the core base 342 by channel base 349
for motion in the horizontal plane that is transverse to a
longitudinal center axis of the trimmer head 25. More specifically,
the motion of the locking slide 370 is restricted such that locking
projection 372 and counterweight 376 are movable both radially
inwardly and outwardly along an axis that is transverse to the
longitudinal center axis of the trimmer head 25. A spring 374
exerts a radially outward biasing force on locking projection 372
such that the locking projection 372 extends radially outwardly
through the locking aperture 348 of the base plate 344 when the
trimmer head 25 is in the at-rest position, i.e., not rotating. A
pair of lock recesses 352 is defined by the inner wall of the knob
350 and is configured to receive the locking projection 372 of the
locking slide 370 therein, thereby non-rotatably fixing the knob
350 to the base plate 344 of the core base 342.
[0061] When the trimmer head is in the at-rest position, the knob
350 is non-rotatably fixed to the core base 342, which is in turn
non-rotatably secured to the core insert 195' and the corresponding
spool 130. As such, the knob 350 facilitates replenishment of the
cutting line on the spool 130 when the trimmer head is in the
at-rest position in the previously discussed manner. However,
during trimming operations in which the trimmer head 25 is
rotating, as the rotational speed of the trimmer head 25 increases,
the counterweight 376 of the locking slide 370 begins to move
radially outwardly away from the longitudinal center axis of the
trimmer head 25, against the biasing force of the spring 374. As
such, as the counterweight 376 moves farther radially outwardly
away from the longitudinal center axis, the locking projection 372
moves radially inwardly toward the longitudinal center axis of the
trimmer head 25. Eventually, the locking projection 372 is fully
retracted from the corresponding lock recess 352 of the knob 350,
at which point knob 350 is free to rotate in either direction with
respect to the base plate 344 of the core base 342. Rotation of the
knob 350 relative to the base plate 344 is facilitated by the
radial bearing 360 that is disposed therebetween. In short, the
knob 350 is free to rotate with respect to the trimmer head 25
during normal trimming operations, which leads to reduced wear of
the knob 350 due to contact with various trimming operations, as
well as line feed, or bump operations.
[0062] Referring now to FIGS. 17, 18, 19A and 19B, an alternative
core structure that could be employed in some embodiment is
illustrated. Specifically, an alternative portion of the core of a
line holding assembly is shown. FIG. 17 illustrates a top
perspective view of an assembled core base 442 of a core 340 of the
line holder assembly 310 (as shown in FIG. 14), and FIG. 18
illustrates an exploded perspective view of core base 442 shown in
FIG. 17. FIGS. 19A and 19B show a cross-sectional view of the core
base 442 shown in FIG. 17, in an at-rest position and an in-use,
rotational position, respectively. The alternative core base
portion 442 shown in FIGS. 17 through 19B is used with the trimmer
head shown in FIGS. 13 and 14.
[0063] As previously discussed, the line holding assembly 310 may
generally be inserted into the first housing portion 100 and second
housing portion 120 described above, and the operation of the line
holding assembly 310 may be substantially similar to the operations
described above. However, the line holding assembly 310 of this
example may include a multi-piece core including a core base 442
and a core insert 195', the core insert 195' being similar to that
previously discussed with regard to the embodiment shown in FIGS. 7
through 12. As shown, the line holding assembly 310 employs a spool
130 as previously discussed with regard to the embodiment of FIGS.
2 through 6, but in alternate embodiments may include a spool 130'
as previously discussed with regard to the embodiment shown in
FIGS. 7 through 12.
[0064] The line holding assembly 310 also includes a line channel
390. The line channel 390 may be formed by core insert 195' that
defines the side walls and top of the line channel 390 and a
channel base 448 of the line channel 390 that is secured to the
core base 442 by fasteners 449 and extends upwardly therefrom. As
best seen in FIG. 18, the core base 442 includes a base plate 444
defining a central aperture 446, a pair of locking apertures 448
defined in its sidewall, and a pair of receivers 265 that are
configured to receive protrusions 260 (FIG. 8) that depend
downwardly from core insert 195' in a snap fit.
[0065] A "bumper knob" 450 is selectively rotatably secured to core
base 442 by threaded fastener 380. A radial bearing 360 including
an inner race 362, an outer race 364 and a plurality of rollers 366
is disposed between core base 442 and knob 450 to facilitate
rotation of knob 450 relative to core base 442 while minimizing
potential wear. Specifically, the outer race 364 of the radial
bearing 360 is received adjacent the sidewall of the central
aperture 446 whereas the inner race 362 is received adjacent the
sidewall of an axial projection 454 that depends upwardly from the
inner surface of the knob 450. A washer 382 that has a diameter
that is greater than the inner diameter of the inner race 362 of
the radial bearing 360 is disposed between a head of the threaded
fastener 380 and the radial bearing 360, thereby securing the knob
450 to the bottom surface of the base plate 444. Note, radial
bearing 360 is also configured to reduce friction in the axial
direction between the base plate 444 and the knob 450.
[0066] A pair of locking levers 470, each locking lever 470
including a locking projection 472 at its first, or bottom, end and
a counterweight 476 at its second, or top, end are pivotably
disposed within the base plate 444 of the core base 442. As shown,
the locking projection 472 and counterweight 476 of each locking
lever 470 are disposed on opposite sides of a pair of mounting
projections 479 that depend outwardly from opposite sides of the
corresponding locking lever 470 at its approximate midpoint. Each
locking lever 470 is pivotably supported on its pair of mounting
projections 479 by a corresponding yoke 481 that depends upwardly
from the bottom of the base plate 444. A spring 474 connects each
locking lever 470 to a corresponding anchor point 483 that is
disposed inwardly of the locking arm 470 such that the
counterweight 476 of each locking arm 470 is biased radially
inwardly by the corresponding spring 474. As such, the locking
projection 472 of each locking lever 470 is biased radially
outwardly by the corresponding spring 474 such that each locking
projection extends radially outwardly through the adjacent locking
aperture 448 of the base plate 444 when the trimmer head 25 is in
the at-rest position, i.e., not rotating. A pair of lock recesses
452 are defined by the inner wall of the knob 450 and are
configured to receive the locking projections 472 therein, thereby
non-rotatably fixing the knob 450 to the base plate 444 of the core
base 442.
[0067] When the trimmer head is in the at-rest position, the knob
450 is non-rotatably fixed to the core base 442, which is in turn
non-rotatably secured to the core insert 195' and the corresponding
spool 130. As such, the knob 450 facilitates replenishment of the
cutting line on the spool 130 when the trimmer head is in the
at-rest position in the previously described manner. However,
during trimming operations in which the trimmer head 25 is
rotating, as the rotational speed of the trimmer head 25 increases,
the counterweights 476 of the locking levers 470 begin to move
radially outwardly away from the longitudinal center axis of the
trimmer head 25, against the biasing force of the spring 474. As
such, as the counterweights 476 move farther radially outwardly
away from the longitudinal center axis, the locking projections 472
moves radially inwardly toward the longitudinal center axis of the
trimmer head 25. Eventually, the locking projections 472 are fully
refracted from the corresponding lock recess 452 of the knob 450,
at which point the knob 450 is free to rotate in either direction
with respect to the base plate 444 of the core base 442. Rotation
of the knob 450 relative to the base plate 444 is facilitated by
the radial bearing 360 that is disposed therebetween. In short, the
knob 450 is free to rotate with respect to the trimmer head 25
during normal trimming operations, which leads to reduced wear of
the knob 450 due to contact with various trimming operations, as
well as line feed, or bump operations.
[0068] In accordance with an example embodiment, a hand-held
cutting device is provided. The device may include an elongated
member graspable along a portion thereof by an operator, a trimmer
head disposed at one end of the elongated member and configured to
be rotatable to perform a cutting function using trimmer line held
at a portion of the trimmer head, and a power unit operably coupled
to the trimmer head to selectively cause rotation of the trimmer
head via turning a shaft. The trimmer head may include a first
housing portion, a line holding assembly to hold and selectively
release the trimmer line, and a second housing portion operably
coupled to the first housing portion to house the line holding
assembly. The line holding assembly may include a spool configured
to hold the trimmer line and a core operably coupled to the spool.
The line holding assembly may be configured such that rotational
movement of the core causes corresponding movement of the spool,
but movement of the core in an axial direction does not cause
corresponding movement of the spool. Some example embodiments may
allow loading of trimmer line without opening the trimmer head in a
simple and fast manner. Still example embodiments may generally not
require a significant increase in part count, and may be useable
regardless of the direction of rotation of the trimmer head (or
even for dual direction trimmer heads). Example embodiments may be
useful for holding line of different diameters and prevent axial
movement of the spool (and the trimmer line) relative to the
eyelets (i.e., orifices 128 on the second housing portion 120) on
the trimmer head when a bump operation occurs or during reloading.
Thus, the line may be less likely to be caught between the spool
and the eyelet, and the line is also less likely to end up on the
wrong side of a middle flange of the spool.
[0069] Many modifications and other embodiments of the inventions
set forth herein will come to mind to one skilled in the art to
which these inventions pertain having the benefit of the teachings
presented in the foregoing descriptions and the associated
drawings. Therefore, it is to be understood that the inventions are
not to be limited to the specific embodiments disclosed and that
modifications and other embodiments are intended to be included
within the scope of the appended claims. Moreover, although the
foregoing descriptions and the associated drawings describe
exemplary embodiments in the context of certain exemplary
combinations of elements and/or functions, it should be appreciated
that different combinations of elements and/or functions may be
provided by alternative embodiments without departing from the
scope of the appended claims. In this regard, for example,
different combinations of elements and/or functions than those
explicitly described above are also contemplated as may be set
forth in some of the appended claims. In cases where advantages,
benefits or solutions to problems are described herein, it should
be appreciated that such advantages, benefits and/or solutions may
be applicable to some example embodiments, but not necessarily all
example embodiments. Thus, any advantages, benefits or solutions
described herein should not be thought of as being critical,
required or essential to all embodiments or to that which is
claimed herein. Although specific terms are employed herein, they
are used in a generic and descriptive sense only and not for
purposes of limitation.
* * * * *