U.S. patent application number 10/015409 was filed with the patent office on 2002-04-11 for lopping tool and method for lopping.
Invention is credited to Labarre, Ernest D., Schofield, Robert T..
Application Number | 20020040528 10/015409 |
Document ID | / |
Family ID | 24037009 |
Filed Date | 2002-04-11 |
United States Patent
Application |
20020040528 |
Kind Code |
A1 |
Schofield, Robert T. ; et
al. |
April 11, 2002 |
Lopping tool and method for lopping
Abstract
A tool for performing lopping, pruning and similar operations
includes a tool support, a tool head, an actuating line and an
actuating handle. The tool support preferably includes a pair of
telescoping tubes and the tool head includes a blade movable to
perform cutting operations. The blade is coupled to the actuating
line and remotely movable by tensioning the actuating line. The
actuating line passes through a portion of the tool support to the
actuating handle. The actuating handle includes a line engagement
mechanism or clutch assembly that engages and holds the line when
the actuating handle is slid on the tool support. The tool is
actuated by a first movement of the actuating handle that causes
the engagement mechanism to engage the actuating line, followed by
a second movement that tensions the line to move the blade. A reel
mechanism below the engagement mechanism collects the actuating
line when the tool support is retracted and dispenses line when the
tool support is extended.
Inventors: |
Schofield, Robert T.;
(Madison, WI) ; Labarre, Ernest D.; (Waunakee,
WI) |
Correspondence
Address: |
John M. Lazarus
FOLEY & LARDNER
Firstar Center
777 East Wisconsin Avenue
Milwaukee
WI
53202-5367
US
|
Family ID: |
24037009 |
Appl. No.: |
10/015409 |
Filed: |
December 12, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10015409 |
Dec 12, 2001 |
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08889295 |
Jul 8, 1997 |
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08889295 |
Jul 8, 1997 |
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08511926 |
Aug 7, 1995 |
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Current U.S.
Class: |
30/249 ;
30/296.1 |
Current CPC
Class: |
A01G 3/083 20130101;
A01G 3/0255 20130101 |
Class at
Publication: |
30/249 ;
30/296.1 |
International
Class: |
B26B 013/26 |
Claims
I claim:
1. A tool for performing lopping, trimming, pruning and similar
cutting operations, comprising: an elongated tool support having an
upper end, a lower end and a cavity extending at least partially
therethrough; a tool head supported on the upper end of the tool
support and including a cutting blade; an actuating line coupled to
the tool head and tensionable to move the cutting blade, the
actuating line passing through at least a portion of the cavity;
and an actuating handle coupled to the lower end of the tool
support, the actuating handle including an actuating line
engagement mechanism, the actuating line engageable by the
actuating line engagement mechanism in response to a first movement
of the actuating handle, and actuating line tensionable in response
to a second movement of the actuating handle.
2. The tool of claim 1, wherein the tool support extends along a
longitudinal axis and the actuating handle is slidable along the
longitudinal axis with respect to the tool support, the first and
second movements being substantially along the longitudinal
axis.
3. The tool of claim 1, wherein the actuating handle is movable
along the tool support, the first and second movements being in a
first direction, and wherein the actuating handle is movable in a
second direction, opposite to the first direction to disengage the
actuating line.
4. The tool of claim 1, wherein the tool support includes a
plurality of telescopingly extensible and retractable elements.
5. The tool of claim 4, further comprising a reel mechanism, the
reel mechanism collecting the actuating line upon retraction of the
tubes and dispensing the actuating line upon extension of the
tubes.
6. The tool of claim 1, wherein the actuating line engaging
mechanism includes a clutch for automatically engaging the
actuating line in response to the first movement of the actuating
handle, the clutch remaining in engagement with the actuating line
throughout the second movement.
7. A tool for performing lopping, trimming, pruning and similar
cutting operations, comprising: an elongated, telescopingly
extensible and retractable tool support having an upper end, a
lower end and a cavity extending at least partially therethrough; a
severing head supported on the upper end of the tool support, the
severing head including a blade movable to perform a cutting
operation; an actuating line coupled to the severing head and
tensionable to move the blade to perform the cutting operation, the
actuating line extending through at least a portion of the cavity
toward the lower end; an actuator for selectively engaging and
tensioning the actuating line; and a reel mechanism disposed
proximate to the lower end of the tool support and coupled to the
actuating line, the reel mechanism collecting the actuating line
during retraction of the tool support and dispensing the actuating
line during extension of the tool support.
8. The tool of claim 7, wherein the actuator includes a clutch for
engaging and tensioning the actuating line for movement of the
blade.
9. The tool of claim 8, wherein the reel mechanism is housed in the
actuating handle.
10. The tool of claim 7, wherein the actuator is movable with
respect to the tool support and includes an actuating line engaging
assembly, the engaging assembly engaging the actuating line by a
first movement of the actuator and tensioning the actuating line by
a second movement of the actuator to move the blade.
11. The tool of claim 10, wherein the actuating line traverses the
line engaging assembly between the lower end of the tool support
and the reel mechanism.
12. A tool for performing lopping, trimming, pruning and similar
cutting operations, comprising: an elongated tool support having an
upper end, a lower end and a cavity extending at least partially
therethrough; a tool head supported at the upper end of the tool
support and including a cutting blade; an actuating line coupled to
the tool head and tensionable to move the cutting blade, the
actuating line passing through at least a portion of the cavity;
and an actuating line engagement mechanism including a collet and a
jam, the collet being selectively movable with respect to the jam
between an engaged position wherein the jam engages the collet on
the actuating line and a disengaged position wherein the actuating
line is free to move with respect to the collet.
13. The tool of claim 12, further comprising an actuating handle
coupled to the tool support and movable with respect thereto, the
engagement mechanism being housed within the actuating handle.
14. The tool of claim 13, wherein the actuating handle is slidable
along the tool support, and wherein sliding movement of the
actuating handle in a first direction urges the collet toward the
jam to engage the actuating line, and sliding movement of the
actuating handle in a second direction urges the collet away from
the jam to disengage the actuating line.
15. The tool of claim 12, wherein the collet has a wedge-shaped,
partially slotted side wall at least partially surrounded by the
jam, and wherein the side wall wedges into the jam in the engaged
position to engage the actuating line.
16. A tool for performing lopping, trimming, pruning and similar
cutting operations, comprising: an elongated tool support having an
upper end, a lower end and a cavity extending at least partially
therethrough; a tool head supported on the upper end of the tool
support and including a cutting blade; an actuating line coupled to
the tool head and tensionable to move the cutting blade, the
actuating line passing through at least a portion of the cavity to
the lower end thereof; and an actuating handle coupled to the lower
end of the tool support and to the actuating line, the actuating
handle being slidable with respect to the tool support in a first
direction to tension the actuating line and move the blade to
perform a cutting operation, the actuating handle being slidable in
a second direction to relax the actuating line.
17. The tool of claim 16, wherein the actuating handle includes an
actuating line engagement mechanism, and wherein movement of the
actuating handle in the first direction automatically engages the
engagement mechanism on the actuating line and movement of the
actuating handle in the second direction automatically disengages
the engagement mechanism from the actuating line.
18. The tool of claim 16, wherein the tool support includes a
plurality of telescopingly extensible and retractable tubes.
19. The tool of claim 18, further comprising a reel mechanism, the
reel mechanism collecting the actuating line upon retraction of the
tubes and dispensing the actuating line upon extension of the
tubes.
20. A method for lopping a branch or the like using a cutting tool
of the type having an elongated tool support, a tool head secured
to an upper end of the tool support and including a movable blade,
an actuating line coupled to the tool head and tensionable to move
the blade, and an actuating member mounted on a lower end of the
tool support and coupled to the actuating line to selectively move
the blade, the method comprising the steps of: (a) moving the
actuating member through a first distance in a predetermined
direction with respect to the tool support to engage the actuating
line; and (b) moving the actuating member through a second distance
in the predetermined direction to tension the actuating line and
thereby move the blade.
21. The method of claim 20, further comprising the step of moving
the actuating member in a direction opposed to the predetermined
direction to release the actuating line.
22. The method of claim 20, wherein the actuating member is
slidable with respect to the tool support and the predetermined
direction is along a longitudinal axis of the tool support.
23. The method of claim 20, wherein the actuating member includes a
clutch mechanism and movement of the actuating member in step (a)
causes a clutch mechanism to engage the actuating line.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to the art of
lopping and pruning tools, particularly of the type including a
pole or tubular tool support for reaching high branches and the
like. More particularly, the invention relates to an improved
telescoping lopper having an actuating arrangement that may be
grasped in one hand for trimming relatively small branches, or in
two hands where additional force is required for cutting larger
branches. The invention also relates to a method for lopping
including two movements of an actuator, a first engaging an
actuating line and a second tensioning the line to move a blade to
perform a desired cutting operation.
[0002] A great number and variety of devices have been proposed and
are commercially available for lopping or pruning branches, limbs
and the like. One type of lopping device, particularly suited to
trimming high branches, includes a elongated shaft or tube on the
upper end of which a lopping mechanism is mounted. The lopping
mechanism includes a hook-shaped jaw and a pivotal blade. The blade
is typically biased in an open position by a spring, and includes a
lever arm extension attached to a cord or rope. To sever a tree
branch or other object, a user places the jaw about the object and
pulls the actuating cord to pivot the blade toward the jaw. A
lopper generally of this type is described in U.S. Pat. No.
5,241,752, issued on Sep. 7, 1993 to Lutzke et al. and assigned to
Fiskars Oy Ab.
[0003] Certain known lopping tools of this type have a shaft
comprised of telescoping poles or tubes lockable with respect to
one another in extended positions, greatly extending the reach of
the device and allowing the user to trim high branches. A device of
this type is described in U.S. Pat. No. 2,259,642, issued on Nov.
6, 1941 to Hoyt. In addition, such tools often include implements
other than the jaw and blade structure, such as a saw, thereby
adding to the utility and versatility of the device (see, e.g. U.S.
Pat. No. 5,241,752 mentioned above).
[0004] Despite these improvements, known pruning and lopping tools
can be difficult to use in many situations. One inconvenience
associated with known lopping tools is that they require the user
to hold and stabilize the shaft supporting the lopping head in one
hand, while pulling the cord or cable to actuate the lopping tool
with the other hand. With this type of lopper, when the user
desires to cut tough or large diameter tree limbs and branches, the
user may not be able to pull downwardly on the cord with sufficient
force to sever the limb. Improvements in such devices have been
proposed, such as that disclosed in U.S. Pat. No. 2,259,642, to
facilitate holding the actuating cord, but nevertheless require the
user to grasp the cord and hold it throughout the cutting
operation.
[0005] Another inconvenience of many known lopping tools is a
tendency for the actuating cords to become entangled. In most known
lopping tools an actuating cord simply dangles from the lopping
head and must be manually secured by the user prior to and
throughout the cut. The cord typically hangs along side of the tool
shaft where it can easily become entangled in branches and twigs
surrounding the tool during use. In addition, for tools supported
on telescoping tubes or shafts, excess cord typically dangles or is
trailed below the shaft when the tool is collapsed (i.e. when the
tubes are telescopingly retracted), such as for a low pruning task
or for storing the tool, again making the cord susceptible to
entanglement.
[0006] Lopping and pruning devices have been proposed that avoid
the entanglement and cord tensioning problems mentioned above by
passing one or more actuating cords or cables through the interior
of a hollow telescoping shaft. In one device of this type,
described in U.S. Pat. No. 5,084,975, issued on Feb. 4, 1992 to
Melter and assigned to Fiskars Oy Ab, a pair of internal cables are
coupled between an actuator and a shears. A compensating pulley
permits extension of the telescoping tubes, while ensuring
sufficient tension on the cord when a user desires to make a cut.
However, the particular actuating arrangement of the tool generally
does not permit a user to apply a maximum of actuating force to
complete a difficult cut.
[0007] There is a need, therefore, for an improved lopping tool
that avoids the inconveniences of currently available devices. In
particular, there is a need for an extensible lopping tool that
permits a user to exert force for completing a cut with both hands
when necessary. There is also a need for an extensible lopping tool
equipped with a system to collect and store excess actuating cord
or cable, such as when the tool support is collapsed or stored, and
to readily draw upon the stored cord or cable when needed to extend
the support handle. In both cases, the improved tool should be of
relatively simple, thereby permitting cost effective manufacture
and improving, or at least maintaining, the useful life of the
tool.
SUMMARY OF THE INVENTION
[0008] The present invention provides an innovative tool for
lopping, trimming and pruning designed to respond to the needs
identified in the foregoing. The tool features an extensible
support tube through which an actuating cord or cable passes. The
cable is associated with a clutch mechanism that permits unimpeded
movement of the cable as the support tube is extended and
retracted, but that engages the cable to actuate the lopper when a
user displaces an actuating handle with respect to the support
tube. The cable is conveniently collected and stored by a reel
mechanism housed in the actuating handle. The actuating handle is
moved through a first distance to engage the cable, then through a
second distance to actuate the lopper. Because the actuating handle
both causes actuation of the clutch mechanism and draws the cable
to perform the cutting operation, a user may actuate the tool with
one hand for less difficult cuts or apply a greater force on the
handle with both hands when necessary. The clutch is automatically
released and the cable collected after each cut.
[0009] Thus, in accordance with a first aspect of the invention, a
tool for performing lopping, trimming, pruning and similar cutting
operations includes an elongated tool support, a tool head, an
actuating line and an actuating handle. The tool support has a
central cavity extending at least partially through it and the tool
head, including a cutting blade, is supported on its upper end. The
actuating line is coupled to the tool head and is tensionable to
move the cutting blade. The actuating line passes through at least
a portion of the central cavity of the tool support. The actuating
handle is coupled to the lower end of the tool support and includes
an actuating line engagement mechanism. The engagement mechanism
engages the actuating cable by a first movement of the actuating
handle and tensions the actuating cable to move the cutting blade
by a second movement of the actuating handle.
[0010] In accordance with another aspect of the invention, a tool
includes an elongated, telescoping, extensible and retractable tool
support having a central cavity extending at least partially
therethrough. A severing tool is supported on the upper end of the
tool support and includes a blade movable to perform a cutting
operation. An actuating line is coupled to the severing tool and is
tensionable to move the blade to perform the cutting operation. The
actuating line extends through at least a portion of the central
cavity of the tool support toward the lower end of the tool
support. An actuating mechanism is provided for selectively
engaging and tensioning the actuating line. A reel mechanism is
disposed adjacent to the lower end of the tool support and is
coupled to the actuating line. The reel mechanism collects the
actuating line upon retraction of the tool support and dispenses
the actuating line upon extension of the tool support.
[0011] In accordance with a further aspect of the invention, a tool
includes an elongated tool support, a tool head, an actuating line
and an actuating handle. The actuating handle is coupled to the
lower end of the tool support and to the actuating line, the line
passing at least through a portion of a central cavity in the tool
support. The actuating handle is slidable with respect to the tool
support in a first direction to tension the actuating line and move
the blade to perform a cutting operation. The actuating handle can
be slid in a second direction to relax the actuating line.
[0012] In accordance with still another aspect of the invention, a
convenient method is provided for actuating a cutting tool of the
type having an elongated tool support, a tool head secured to an
upper end of the tool support and including a movable blade, an
actuating line coupled to the tool head and tensionable to move the
blade, and an actuating member mounted on a lower end of the tool
support and coupled to the actuating line to selectively move the
blade. The method includes a first step of moving the actuating
member through a first distance in a predetermined direction with
respect to the tool support to engage the actuating line. With the
actuating line thus engaged, the method includes a second step of
moving the actuating member through a second distance in the
predetermined direction to tension the actuating line and thereby
to perform the desired cutting operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will become more fully understood from
the following detailed description, taken in conjunction with the
accompanying drawings, wherein like reference numerals refer to
like parts, in which:
[0014] FIG. 1 is an overall side elevational view of an exemplary
lopping tool in accordance with the invention;
[0015] FIG. 2 is a side elevational view of the lopping tool of
FIG. 1, illustrating the tool support in its extended position;
[0016] FIG. 3 is a side elevational view of the lopping tool of
FIG. 1, showing the actuating handle slid into its fully actuated
position for performing a cutting operation;
[0017] FIG. 4 is a partial sectional view of the tool head of the
device shown in FIG. 1, illustrating an exemplary configuration of
the actuating and cutting elements of the tool head;
[0018] FIG. 5 is a sectional detail view of the actuating handle of
the tool shown in FIG. 1, illustrating the internal elements that
engage and tension the actuating line, in their non-actuated
position;
[0019] FIG. 6 is a sectional detail view of the actuating handle of
FIG. 5, showing the internal elements of the handle in a partially
actuated position;
[0020] FIG. 7 is a sectional detail view of the actuating handle of
FIG. 5, showing the internal elements in a fully actuated
position;
[0021] FIG. 8 is a sectional view of the actuating handle of FIG. 5
along line 8-8; and
[0022] FIG. 9 is a sectional view of the actuating handle of FIG. 5
along line 9-9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Turning now to the drawings and referring to FIG. 1, a tool
10 for performing lopping, trimming and pruning operations includes
a tool head 12, a telescoping tool support 14 and an actuating
handle 16. Tool support 14 is preferably a hollow tubular structure
comprising an upper tube 18 slidingly received within a lower tube
20. A securing collar or clamp 22 is provided on an upper end of
lower tube 20 for setting and maintaining tool support 14 at a
desired length. Thus, collar 22 may be loosened around upper tube
18 to permit tube 18 to be slid into a desired position extending
from lower tube 20 as shown in FIG. 2. Once tube 18 is in the
desired position, collar 22 may be tightened around tube 18 to
secure and maintain the position. Collar 22 may be of generally
known design, such as the clamp described in U.S. Pat. No.
5,084,975, which is hereby incorporated herein by reference.
[0024] Tool support 14 has a gripping area 24 that may includes a
textured grip formed on or added to the outside surface of lower
tube 20. Grip 24 is located just above actuating handle 16 so that
grip 24 and actuating handle 16 may be grasped simultaneously by a
user, such as for cutting small branches and limbs as will be
described more fully below. A similar grip (not shown) may be
formed on the outer surface of actuating handle 16. A stop collar
or clamp 26, which may be generally similar to collar 22, is
provided on an upper end of actuating handle 16. Collar 26 permits
a user to lock actuating handle 16 in position with respect to
lower tube 20, thereby preventing lopping actuation of tool 10.
[0025] As illustrated in the FIGURES, tool head 12 is supported on
an upper end 28 of tool support 14. Tool head 12 includes at least
a severing tool for performing lopping, pruning and similar
operations. In the preferred embodiment illustrated, tool head 12
includes a hook-shaped jaw 30 coupled to a movable blade 32. As
with conventional lopping tools, jaw 30 may be placed around a limb
or branch to be cut and blade 32 moved toward jaw 30 to sever the
branch. Blade 32 is fixed to an actuating lever 34 that, in turn,
is moved by tensioning a flexible actuating line 36 as described
below. Tool head 12 may conveniently include additional tools, such
as a saw 38.
[0026] Externally, actuating handle 16 presents an actuating tube
40 coupled to a lower handle housing 42. Actuating tube 40 and
handle housing 42 are fixed with respect to one another during
assembly of tool 10. In the presently preferred embodiment, handle
housing 42 includes two mirror-image shell halves fitted over
actuating tube 40 as described below. As indicated by line A in the
FIGURES, tool support 14 and actuating handle 16 share a common
longitudinal axis. Internally, actuating handle 16 is coupled to
actuating line 36, which passes from tool head 12 through the
interior of tool support 14.
[0027] As illustrated in FIG. 3, a lopping operation is carried out
by tool 10 by actuating or drawing actuating handle 16 downwardly,
away from the tool head 12. As will be described in greater detail
below, downward movement of actuating handle 16 causes actuating
tube 40 to slide along longitudinal axis A with respect to tool
support 14. In a first phase of this motion, actuating handle 16
seizes or engages actuating line 36, while in a second phase of
motion handle 16 tensions or pulls actuating line 36 downwardly,
resulting in pivotal movement of blade 32 toward jaw 30, performing
a desired lopping operation. When a user desires to cut a small or
thin branch offering little resistance to blade 32, the user may
grasp grip 24 of tool support 14 in one hand and actuating tube 40
in the other hand to displace handle 16 with respect to support 14
for cutting. However, for larger or more difficult cuts, the user
may grasp actuating tube 40 with both hands to exert additional
force on blade 32 through actuating line 36. Because actuating
handle 16 moves along tube support 14, tool 10 is inherently
stabilized by the user's hold on handle 16, freeing the user to
concentrate on performing the cutting operation without the
distractions of handling the actuating line, stabilizing the tool,
or avoiding entanglement of line 36.
[0028] The presently preferred configuration of tool head 12 is
illustrated in FIG. 4. Tool head 12 includes jaw 30 formed
integrally with a support extension or shank 44. Shank 44 is fixed
to the upper end 28 of upper tube 18 via a bracket 46 and rivets
48, or similar fasteners. Blade 32 is mounted on shank 44 by means
of a rivet 50 that holds blade 32 firmly against jaw 30 while
permitting blade 32 to pivot toward jaw 30. Below blade 32,
actuating lever 34 is pivotally supported on shank 44 by a bolt 52
held in place by a mating nut (not shown). An actuation link 54 is
secured between an extension 55 from blade 32 and actuating lever
34. Link 54 is pivotally coupled to extension 55 and to lever 34 by
rivets 56 and 58, such that downward pivotal movement of actuating
lever 34 draws link 54 downwardly, resulting in rotation of blade
32 toward jaw 30. Thus, blade 32 is moveable between an open
position, shown in FIG. 4, and a closed or cutting position (see
FIG. 3) by downward movement of lever 34. Lever 34 is biased into
the open position by a torsion spring 60 mounted on bolt 52 and
extending between bracket 46 and a stud or rivet 62 on lever
34.
[0029] Actuating lever 34 is coupled to actuating line 36 for
remotely controlling movement of blade 32 by movement of actuating
handle 16. While actuating line 36 could be directly coupled to
actuating lever 34, it is preferably directed around pulleys to
compound the tensile force exerted on line 36 by a user. Thus, as
shown in FIG. 4, an end 63 of actuating line 36 is secured to a
pulley carrier 64 pivotally held on actuating lever 34 by a rivet
65. Pulley carrier 64 supports an upper pulley 66, while a lower
pulley 68 is held on a lower extension 69 of shank 44. From pulley
support 64, line 36 is looped around lower pulley 68, then around
upper pulley 66, before extending downwardly to upper end 28 of
tube 18. Line 36 enters into upper end 28 through an opening 70,
preferably surrounded by a grommet 71 to protect line 36 and tube
18 from excessive wear. From opening 70, actuating line 36 extends
downwardly through a central cavity 72 in tool support 14.
[0030] As discussed above, an advantage of the preferred
configuration of tool 10 resides in its ability to engage actuating
line 36 by a first movement of actuating handle 16 and to actuate
or move blade 32 toward jaw 30 to execute a desired cutting
operation by a second, further movement of handle 16. FIGS. 5, 6
and 7 illustrate the preferred internal configuration of actuating
handle 16 that facilitates this aspect of tool 10. As shown in the
FIGURES, actuating handle 16 includes a clutch or line engagement
mechanism, designated generally by the reference numeral 74,
including a shuttle 76 comprising a plug 78 and collet 80, a jam 82
and a clutch actuator 84. A reel mechanism 86 is also provided in
handle housing 42 to collect and dispense actuating line 36 as
discussed below.
[0031] As best illustrated in FIGS. 5 and 6, upper tube 18 is
slidably received in lower tube 20, which is, in turn, slidable
within actuating tube 40. Clutch actuator 84 includes a cylindrical
wall portion 87 and an annular shoulder 88 in abutment with a lower
end of lower tube 20. Clutch actuator 84 is fixed with respect to
lower tube 20 during assembly of tool 10, such as by gluing wall
portion 87 within lower tube 20. Clutch actuator 84 includes an
annular, reduced diameter triggering ring 90 extending inwardly for
triggering collet 80 to engage actuating line 36 as described
below.
[0032] Plug 78 includes a generally cylindrical upper wall 92 in
which at least one elongated slot 94 is formed. Slot 94 permits
upper wall 92 to be squeezed or compressed radially during
actuation of tool 10. In an upper region of plug 78, an annular
protrusion extends outwardly to form an upper inclined abutment
surface 98 and a lower inclined abutment surface 100. Abutment
surfaces 98 and 100 cooperate with triggering ring 90 upon movement
of actuating handle 16 as discussed below. Adjacent to a lower
region, plug 78 further includes an inner annular retaining ring
102 for securing collet 80 in its assembled position, as well as a
pair of guide rings 104 for guiding shuttle 76 through upward and
downward movement.
[0033] In the presently preferred configuration illustrated, collet
80 includes a head section 106 having an annular, inclined upper
edge 108 for facilitating insertion of head section 106 into plug
78 during assembly. Head section 106 of collet 80 also includes an
annular groove 110 located and dimensioned to receive retaining
ring 102 of plug 78, thereby maintaining plug 78 and collet 80
interconnected. Collet 80 further includes a tail section 112
extending downwardly from head section 106. At least one elongated
groove 114 is formed in tail section 112, permitting tail section
112 to be squeezed or compressed radially to engage and seize
actuating line 36 as described below. Tail section 112 terminates
in a frustoconical or wedge-shaped lower portion 116 having an
interior surface 118 adapted to contact actuating line 36 during
actuation of tool 10.
[0034] Jam 82 partially surrounds and cooperates with plug 78 and
collet 80 during actuation of tool 10. Thus, jam 82 includes a
generally cylindrical upper wall portion 120 in contact with
guiding rings 104 of plug 78, and an annular shoulder 122 on which
plug 78 rests in the non-actuated position illustrated in FIG. 5.
In a bottom region, jam 82 includes an annular locating ring 124
designed to cooperate with a recess 125 formed within handle
housing 42 to hold jam 82 solidly in place throughout actuation of
tool 10. An internal bore 126 is formed in jam 82 for contacting
lower portion 116 of collet 80 as described below.
[0035] Clutch mechanism 74 is assembled as follows. First, head
section 106 of collet 80 is slipped through bore 126 of jam 82.
Next, plug 78 is inserted into upper wall portion 120 of jam 82 and
is snapped into engagement with head section 106 of collet 80. As
mentioned above, inclined upper edge 108 of collet 80 facilitates
its insertion in plug 78 and the cooperation of ring 102 with
groove 110 maintains plug 78 and collet 80 interlocked. Jam 82,
plug 78 and collet 80 are then placed in one shell half of handle
housing 42 by pressing locating ring 124 of jam 82 into recess 125.
Jam 82 may be secured in handle housing 42 by additional means,
such as by gluing upper wall portion 120 to handle housing 42.
Actuating tube 40 is inserted into handle housing 42 and fixed
within handle housing 42 above locating ring 124, such as by
gluing. Separately, clutch actuator 84 is fixed to lower tube 20,
such as by gluing wall portion 87 within tube 20. After assembly of
reel mechanism 86 as described below, handle housing 42 is covered
by a mating shell half (not shown) and lower tube 20 is inserted
into actuating tube 40 and slid downwardly until triggering ring 90
snaps into engagement with protrusion 96 of plug 78.
[0036] As shown in FIG. 8, the resulting assembly comprises housing
42 and tube 40 nested and fixed to one another, and lower tube 20
slidably received in actuating tube 40 and fixed to clutch actuator
wall 87. Upper inclined surface 98 of plug 78 extends above
triggering ring 90 and slots 94 extend radially therefrom. Collet
80 is fixed within plug 78. Actuating line 36 extends freely
through the center of the assembly. As shown in FIG. 9, locating
ring 124 is lodged within handle housing 42, and lower portion 116
of collet 80 extends through bore 126 with slots 114 extending
radially therefrom. Actuating line 36 extends through engagement
surface 118 of collet 80.
[0037] Returning to FIG. 5, handle housing 42 includes, below
recess 125, an annular rib 128 having a central opening 130 for
guiding actuating line 36 toward collet 80. Below annular rib 128,
handle housing 42 forms an enlarged housing 132 for receiving reel
mechanism 86, as well as a support axle 134 for holding mechanism
86. Reel mechanism 86 includes a take-up reel or bobbin 136
rotationally mounted on axle 134 for storing actuating line 36. A
flat coil biasing spring 138 is wound within bobbin 136 and
includes a hook-shaped end 139 bearing against an appropriate
spring engagement pin 140 on bobbin 136 and a tang-shaped
attachment end 142 inserted and secured in an appropriate slot 144
in axle 134.
[0038] During assembly of tool 10, actuating line 136 is wound on
bobbin 136 and bobbin 136 is placed within handle housing 42 as
shown. With clutch mechanism 74 assembled as described above,
actuating line 136 is fed from bobbin 136 through bore 130 and up
through collet 80, actuator 84 and lower and upper tubes 20 and 18.
At upper end 28 of upper tube 18, actuating line 36 is removed
through opening 70 (see FIG. 4), fed through pulleys 66 and 68, and
attached to pulley support 64. Handle housing 42 is then closed to
cover clutch mechanism 84 and reel mechanism 86.
[0039] Tool 10 operates as follows. From the collapsed position
shown in FIG. 1, upper tube 18 may be extended or retracted to a
desired height and fixed with respect to lower tube 20 by setting
clamp 22. During extension of tubes 18 and 20, reel mechanism 86
dispenses actuating line 36 from bobbin 136 through clutch
mechanism 74 and tubes 20 and 18, maintaining actuating line 36
taut, but with insufficient tension to move blade 32 toward jaw 30.
As tube 18 is retracted within tube 20, reel mechanism 74 collects
actuating line 36 on bobbin 136, again without actuating blade
32.
[0040] When a user desires to lop a branch or the like, tool 10 is
positioned such that jaw 30 partially surrounds the branch, and
actuating handle 16 is slid on tube 20 along axis A in a direction
away from tool head 12, as shown in FIGS. 6 and 7, typically
downwardly when the user is positioned below the object being
severed. As handle 16 is moved downwardly through a first distance
146 (see FIG. 6), triggering ring 90 contacts lower inclined
surface 100 of plug 78, pulling plug 78 and collet 80 upwardly
within jam 82 and compressing wedge-shaped lower portion 116 of
collet 80 within bore 126 of jam 82 until interior surface 118
engages actuating line 36. Once collet 80 has engaged line 36,
further movement of actuating handle 16 causes triggering ring 90
to compress upper wall 92 of plug 78 until ring 90 escapes plug 78.
Once collet 80 is thus engaged on actuating ling 36, it remains in
this engaged position, preventing reel mechanism 86 from dispensing
additional line, thereby tensioning actuating line 36. As actuating
handle 16 is moved further downwardly, tension on actuating line 36
causes actuating lever 34 to pivot downwardly, moving blade 32
toward jaw 30. Full actuation of tool 10 occurs as actuating handle
16 is displaced over a distance 148, as indicated in FIG. 7.
[0041] After a cutting operation has been completed, actuating
handle 16 is slid upwardly over lower tube 20. This motion
eventually causes triggering ring 90 of clutch actuator 84 to
contact upper inclined surface 98 of plug 78. Force exerted on
surface 98 by ring 90 causes plug 78 and collet 80 to be displaced
downwardly, dislodging lower portion 116 of collet 80 from jam 82
and thereby releasing actuating line 36. Reel mechanism 86 then
takes up any slack in line 36.
[0042] While the embodiments illustrated in the FIGURES and
described above are presently preferred, it should be understood
that these embodiments are offered by way of example only. The
invention is not intended to be limited to any particular
embodiment, but is intended to extend to various modifications that
nevertheless fall within the scope of the appended claims. For
example, variants on the engagement mechanism discussed above may
be envisioned, such as a structure including one or more cam-type
or cleat-type elements that squeeze or jam the actuating line
during the first phase of motion of the actuating handle. Moreover,
certain of the advantages flowing from the preferred embodiment
described above may be attained through the use of a manually
engageable clutch or clamping device.
* * * * *