SHAFT CLAMP

BAGUE DE SERRAGE

Description

2
SHAFT CLAMP
Field of the invention:
The present invention relates to the field of counterbalancing mechanisms.
More particularly, the present invention relates to an improved component
(hereinafter
referred to also as a "shaft clamp") that may be used in a drive mechanism,
such as
a chain hoist, for example, and also relates to a drive mechanism provided
with such
a shaft clamp, to a kit with corresponding components for assembling the same,
and
to corresponding methods of manufacturing, assembling and/or operating
associated
thereto.
Background:
Garage doors and the like are well known in the art. Indeed, most garage doors
usually require to be provided with a counterbalancing system for
counterbalancing
the weight of the door in order to decrease the force required to open the
door and
also safely facilitate its closing from a raised to a lowered position.
Counterbalancing
systems can be found in many other types of cable-operated doors, such as
slidable
truck doors and trailer doors, for example.
It is also known in the art that a widely used type of counterbalancing system

generally comprises a pair of spaced apart cable drums connected to
corresponding
cables, each cable being in turn connected to a lower opposite side edge of
the garage
door. The cable drums are usually mounted on an overhead shaft which is
typically
supported above the door opening and is connected to one or more torsion
springs
which are each fixed to the shaft at one end, and operatively secured to a
fixed
structure such as the wall, or a wall bracket, for example, at the other end,
so that the
cable drums are biased to rotate in a direction which winds the cables onto
the drums
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and counteracts the weight of the door connected to the cables. The torsion
springs
are adjusted to properly balance the weight of the door so that minimal
opening and
closing efforts are required, either manually or when motor controlled.
It is also known in the art that conventional, low cost adjustment devices
used
for the above-mentioned type of counterbalancing system, and widely utilized
in the
garage door industry, are generally cylindrical "anchors" commonly referred to
also as
"plugs" ("collars", "cones", etc.) which are connected to the ends of the
torsion springs
and are thus mounted on the aforementioned shaft for adjusting the deflection
of the
springs to preset the torsional (or counterbalancing) force of the spring.
In operation, torque is transferred between the torsion spring, overhead
shaft,
and anchors or plugs, which operatively connect the shaft to the spring, in
order to
counterbalance the weight of the garage door. Usually, each torsion spring is
fixed to
the overhead shaft at one end, by means of a plug known as a "winding plug",
and
operatively secured to the wall via a bracket at the other end, by means of
another
plug known as a "stationary plug".
Large, vertical opening door assemblies, such as commercial and residential
sectional garage doors, also usually require mechanisms to counterbalance the
weight of the door in order to minimize door opening efforts and to control
movement
of the door from an opened to a closed position. Large sectional garage doors
for
commercial and residential applications may be manually or power operated. In
either
case, but particularly for manual operation, counterbalancing mechanisms have
been
used for many years to counterbalance the weight of the door and control its
opening
and closing movements so that one person can easily control operation of the
door.
Counterbalancing mechanisms are also advantageous for power operated vertical
opening doors since they reduce motor power requirements and the required
strength
of the door opening and closing mechanism. In other words, lighter weight,
lower cost,
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door control mechanisms may be used if a counterbalancing mechanism is
connected
to the door to assist the opening and closing actions.
It is also known that in North American markets, there are mainly two types of
counterbalancing systems that are used with overhead doors.
The first type is with a "live" axle. Typically, a cable links together the
bottom of
the door to a drum. This drum is fixed to a corresponding rotating shaft (i.e.
"live" axle)
of the counterbalancing system. Counterbalancing is usually made with a spring-
plug
assembly including a stationary plug fixed to an anchor plate, a winding plug
fixed to
the shaft, and a torsion spring that links the two plugs together.
The second type of counterbalancing systems is with a "dead" axle shaft. In
this
case, a "drum-plug" is free to move and rotate on the counterbalancing shaft.
Typically, a cable links together the bottom of the door to the drum-plug. On
the other
side, a winding plug is fixed to the shaft. The counterbalancing system
typically links
the winding plug to the drum-plug via the spring.
Similarly, self-storage doors and the like generally use these two concepts in
order to provide the closing/opening function:
a) the first concept is "live axle" where the main shaft is turning when the
door
opens or closes ¨ in the case of such a "live" axle, the axle assembly turns
with the door when operated; and
b) the second concept is "dead axle" where the shaft is fixed/clamped, and
where other components, such as steel drum, have bearings inserted in to
allow rotation of the complete door curtain ¨ in the case of such a "dead"
axle,
the axle assembly that remains stationary when the door is operated.
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Most of the small doors are operated manually since their height allow the
operator to reach the upper limit of the opening height. For higher door, a
manual
chain hoist is usually used in order to completely open the door, that is, out
of a normal
human reach.
In the dead axle application, because the shaft is not turning, the drive
mechanism has to somehow be linked to the moving/rotating part, here said the
drum.
Most common torque transmission means are sprocket and roller chain or gears,
and
the like, for example.
In transmitting the torque, three conditions generally have to be met to
insure
adequate function of the product:
1) good axial alignment between the driving and driven member (sprocket or
gear);
2) blocking of the rotational movement of the hoist when the torque is exerted
on
the hand chain by the person opening/closing the door; and
3) proper center distance for gear or sprocket drive mechanism.
The function of locating the shaft center-to-center distances and locking the
hoist on the round hollow shaft is usually made by the same components
heresaid
shaft sleeve.
Over the years, the Assignee of the present application has developed various
innovative products and manufacturing processes to be used in the field of
counterbalancing mechanisms (ex. garage doors, truck doors, etc.),
particularly in
relation to cones, plugs, chain hoists, and the like, examples of which are
described
in the following US patents, patent applications and/or industrial designs,
the contents
of which are incorporated herein by reference: 6,174,575 B1; 6,279,268131;
6,378,170 Bl; 6,485,006 B1; 6,502,281 B2;
6,681,809 B2; 6,694,673 B2;
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6,712,116 B2; 6,907,964 B2; 6,931,810 B2;
6,959,751 B2; 6,986,378 B2;
6,988,527 B2; 7,000,292 B2; 7,000,354 B2;
7,086,441 B2; 7,350,333 B2;
7,441,749 B2; 7,543,625 B2; 7,600,344 B2; D490,685; D520,338; D524,633;
2002/0117787 Al; 2003/0024658 Al; 2003/0115928 Al;
2003/0198790 Al;
2003/0221801 Al; 2003/0230389 Al; 2004/0000109 Al;
2004/0003554 Al;
2004/0020609 Al; 2004/0089097 Al; 2004/0103505 Al;
2004/0124050 Al;
2004/0182007 Al; 2005/0006545 Al; 2005/0183341 Al;
2006/0185800 Al;
2007/0012410 Al; 2007/0084012 Al; 2007/0145339 Al;
2007/0204515 Al;
2007/0283525 Al; 2008/0023603 Al; 2009/0314869 Al; 2011/0240236 Al;
2017/0241498 Al; and 2017/0328104 A.
Examples of these products developed by the Assignee are also described in
the following Canadian patents and/or patent applications: 2,184,507;
2,206,547;
2,220,710; 2,253,692; 2,263,666; 2,277,646; 2,293,224; 2,303,047; 2,306,610;
2,313,945; 2,313,946; 2,328,814; 2,344,952; 2,348,101; 2,352,620; 2,353,067;
2,369,705, 2,376,399; 2,381,027; 2,381,051, 2,381,054; 2,382,601; 2,382,606;
2,382,607; 2,382,661; 2,382,822; 2,384,219; 2,390,433; 2,392,417; 2,393,866;
2,398,684, 2,400,701; 2,401,084; 2,401,329; 2,407,464; 2,416,246; 2,419,185;
2,422,491; 2,425,108; 2,426,068; 2,430,434; 2,430,680; 2,435,362; 2,444,509;
2,445,719; 2,454,939; 2,458,157; 2,477,679; 2,497,471; 2,453,838; 2,504,030;
2,519,142; 2,568,048; 2,603,178; 2,642,857; 2,651,530; and 2,897,206.
Further examples of these products developed by the Assignee are also
described and illustrated in the following Canadian industrial designs:
102881;
110443; and 110502.
Despite these various improvements over the years, there is always a need to
continue innovating and finding better and/or different ways of manufacturing,

assembling and/or operating components of a chain hoist, for example.
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Indeed, it would be particularly advantageous to provide a component to be
used with a chain hoist in a more efficient, more precise, more accurate, more
reliable,
more adjustable, more versatile, more adaptable, more ergonomic and/or more
desirable manner, than what is possible with a standard shaft sleeve.
Thus, it would be particularly useful to be able to provide such an improved
component which would be able to overcome or at the very least minimize some
of
known drawbacks associated with conventional shaft sleeves, for example.
Summary of the invention:
An object of the present invention is to provide a shaft clamp which, by
virtue
of its design and components, would be an improvement over other related
.. conventional shaft sleeves and/or chain hoist methods known in the prior
art.
In accordance with the present invention, the above object is achieved, as
will
be easily understood from the present description, with a shaft clamp (also
referred to
herein simply as "clamp") such as the one briefly described herein and such as
the
one exemplified in the accompanying drawings.
More particularly, according to one aspect of the present invention, an object
is
to provide a shaft clamp to be used with a chain hoist of a counterbalancing
mechanism, the shaft clamp comprising:
a non-circular main body being mountable onto the chain hoist for cooperating
with a drive shaft of the counterbalancing mechanism, the main body of the
shaft
clamp having a cross-sectional profile with a plurality of segmented sides,
each side
being provided with a corresponding threaded orifice for receiving a
corresponding
setscrew intended to be secured against the drive shaft. The shaft clamp may
have a
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substantially V-shaped body, with at least two segmented sides, each side
being
provided with a corresponding orifice for receiving a corresponding setscrew,
and
each side being connected to one another via a bridging portion. The shaft
clamp may
comprise at least one mounting component for removably mounting the shaft
clamp
onto at least one side panel (and/or frame) of the chain hoist. According to
one
possible embodiment, each segmented side of the shaft clamp is substantially T-

shaped, and includes a pair of opposite inserts (and/or protrusions)
configured for
removably inserted into corresponding slots of oppositely distanced side
panels of the
chain hoist. The shaft clamp may also be provided with at least one visual
indication
representative of tightening direction of setscrew and/or recommended and/or
maximum torque to be used.
According to yet another aspect of the invention, there is also provided a
chain
hoist provided with the above-mentioned shaft clamp.
According to yet another aspect of the invention, there is also provided a
counterbalancing mechanism provided with the above-mentioned shaft clamp
and/or
chain hoist.
According to yet another aspect of the invention, there is also provided a
door
assembly provided with the above-mentioned shaft clamp, chain hoist and/or
counterbalancing mechanism.
According to yet another aspect of the invention, there is also provided a
method of manufacturing components of the above-mentioned shaft clamp, chain
hoist, counterbalancing mechanism and/or door assembly.
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According to yet another aspect of the invention, there is also provided a
method of assembling components of the above-mentioned shaft clamp, chain
hoist,
counterbalancing mechanism and/or door assembly.
According to yet another aspect of the invention, there is also provided a
method of using the above-mentioned shaft clamp, chain hoist, counterbalancing

mechanism and/or door asseMbly, and/or component(s) thereof.
According to yet another aspect of the invention, there is also provided a kit

with components for assembling the above-mentioned shaft clamp, chain hoist,
counterbalancing mechanism and/or door assembly.
According to yet another aspect of the present invention, there is also
provided
a set of components for interchanging with components of the above-mentioned
kit.
According to yet another aspect of the present invention, there is also
provided
a method of assembling components of the above-mentioned kit and/or set.
According to yet another aspect of the present invention, there is also
provided
a method of doing business with the above-mentioned shaft clamp, chain hoist,
counterbalancing mechanism, door assembly, component(s) thereof, kit, set
and/or
method(s).
The objects, advantages, and other features of the present invention will
become more apparent upon reading of the following non-restrictive description
of
preferred embodiments thereof, given for the purpose of exemplification only,
with
reference to the accompanying drawings.
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Brief description of the drawings:
Figure 1 is a cross-sectional representation a conventional chain hoist
cooperating with a drive shaft of a counterbalancing mechanism, the chain
hoist being
.. provided with a conventional shaft sleeve mounted concentrically about the
drive shaft
of the counterbalancing mechanism according to the prior art.
Figure 2 is a side picture of a conventional chain hoist.
Figure 3 is an enlarged view of a portion of what is shown in Figure 2 to
better
illustrate the conventional shaft sleeve being welded onto opposite side
panels of the
frame of the chain hoist according to the prior art.
Figure 4 is a perspective view of a conventional shaft sleeve having been
.. manufactured via steel casting, the shaft sleeve being shown provided with
two
setscrews inserted into corresponding threaded orifices of the shaft sleeve.
Figure 5 is a perspective view of a conventional shaft sleeve having been
manufactured via aluminum die casting, the shaft sleeve being shown provided
with
two setscrews inserted into corresponding threaded orifices of the shaft
sleeve.
Figure 6 is an exploded view of some of the components shown in Figure 1 to
better illustrate inner components of the chain hoist and to better illustrate
the shaft
sleeve thereof.
Figure 7 is a cross-sectional representation a new chain hoist cooperating
with
a drive shaft of a counterbalancing mechanism, the chain hoist being provided
with a
shaft clamp cooperating with the drive shaft of the counterbalancing mechanism

according to a possible embodiment of the present invention.
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Figure 8 is an exploded view of some of the components shown in Figure 1 to
better illustrate inner components of the chain hoist and to better illustrate
the shaft
sleeve thereof.
Figure 9 is a top perspective view of a shaft clamp according to a possible
embodiment of the present invention.
Detailed description of preferred embodiments of the invention:
In the following description, the same numerical references refer to similar
elements. Furthermore, for sake of simplicity and clarity, namely so as to not
unduly
burden the figures with several reference numbers, only some figures have been

provided with reference numbers, and components and features of the present
invention illustrated in other figures can be easily inferred therefrom. The
embodiments, geometrical configurations, materials mentioned and/or dimensions

shown in the figures are preferred, for exemplification purposes only.
Moreover, although the present invention was primarily designed for use with
drive mechanisms of counterbalancing mechanisms, such as chain hoists used for

opening and closing doors, for example, it may be used with other objects
and/or in
other types of applications, as apparent to a person skilled in the art. For
this reason,
expressions such as "drive mechanism", "counterbalancing mechanism", "chain
hoist", "opening", "closing", "door", etc., used herein should not be taken so
as to limit
the scope of the present invention and include all other kinds of objects
and/or
applications with which the present invention could be used and may be useful.
For
example, the present shaft clamp could also be used with and/or for various
other
types of "hoists" and/or "drive mechanisms", as can be easily understood by a
person
skilled in the art.
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Moreover, in the context of the present invention, the expressions "shaft
clamp",
"clamp", "assembly", "system", "device", "apparatus", "product", "unit",
"equipment",
"tool", "method" and "kit", as well as any other equivalent expression(s)
and/or
.. compound word(s) thereof known in the art will be used interchangeably, as
apparent
to a person skilled in the art. This applies also for any other mutually
equivalent
expressions, such as, for example: a) "closing"; "opening", "raising",
"lowering",
"moving", "driving", "displacing", "adjusting", etc.; b) "door", "curtain",
etc.; c) "stroke",
"travel", "range", "motion", etc.; d) "distance", "position", "location",
etc.; e) "hole",
.. "orifice", "passage", "channel", "conduit", "path", "flow", etc.; f)
"fastening", "securing",
"locking", "restraining", "affixing", "holding", "adjusting", etc.; as well as
for any other
mutually equivalent expressions, pertaining to the aforementioned expressions
and/or
to any other structural and/or functional aspects of the present invention, as
also
apparent to a person skilled in the art. Also, in the context of the present
description,
expressions such as "can", "may", "might", "will", "could", "should", "would",
etc., may
also be used interchangeably, whenever appropriate, as also apparent to a
person
skilled in the art.
Furthermore, in the context of the present description, it will be considered
that
all elongated objects will have an implicit "longitudinal axis" or
"centerline", such as
the longitudinal axis of shaft for example, or the centerline of a coiled
spring, for
example, and that expressions such as "connected" and "connectable", or
"mounted"
and "mountable", may be interchangeable, in that the present invention also
relates to
a kit with corresponding components for assembling a resulting fully-assembled
and
fully-operational shaft clamp, and/or associated chain hoist and/or
counterbalancing
mechanism, and/or resulting door assembly.
Moreover, components of the present system(s) and/or steps of the method(s)
described herein could be modified, simplified, altered, omitted and/or
interchanged,
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without departing from the scope of the present invention, depending on the
particular
applications which the present invention is intended for, and the desired end
results,
as briefly exemplified herein and as also apparent to a person skilled in the
art.
In addition, although the preferred embodiments of the present invention as
illustrated in the accompanying drawings comprise various components, and
although
the preferred embodiments of the present chain hoist and corresponding
portion(s)/part(s)/component(s) (ex. shaft clamp) as shown consist of certain
geometrical configurations, as explained and illustrated herein, not all of
these
components and geometries are essential to the invention and thus should not
be
taken in their restrictive sense, i.e. should not be taken so as to limit the
scope of the
present invention. It is to be understood, as also apparent to a person
skilled in the
art, that other suitable components and cooperation thereinbetween, as well as
other
suitable geometrical configurations may be used for the present chain hoist
and
corresponding portion(s)/part(s)/component(s) (ex. shaft clamp) according to
the
present invention, as will be briefly explained herein and as can be easily
inferred
herefrom by a person skilled in the art, without departing from the scope of
the present
invention.
Broadly described, and as better exemplified in the accompanying drawings,
the present invention relates to a shaft clamp to be used with a chain hoist
in a simpler,
easier, faster, more accurate, more effective, more functional, more reliable
and/or
more versatile manner than what is possible with other conventional devices
(ex. shaft
sleeves).
List of numerical references for some of the corresponding possible components

illustrated in the accompanying drawings:
1. threaded fastener (ex. setscrew)
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2. hoist frame
3. pocket wheel
4. input shaft
5. driving component (ex. driving sprocket (or gear))
6. retaining clip
7. shaft clamp
8. threaded hole
9. protrusion
11. angle
12. frame hole (or "opening")
13. door shaft
14 bearing
15. tab
16. opening
17. driven component (ex. sprocket (or gear))
18. mounted drum
Following is a brief description of how the present invention works according
to
possible embodiment(s).
Indeed, the present shaft clamp and/or other associated inventive aspects (ex.

chain hoist, counterbalancing mechanism, door assembly, etc.) may include one
and/or several of the following possible components and features (and/or
different
possible combination(s) and/or permutation(s) thereof):
Indeed, according to one possible embodiment, and as can be easily
understood when referring to the accompanying drawings, there is provided a
chain
hoist.
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Optionally, the chain hoist can be a manual chain hoist composed of an input
shaft (4), on which is assembled a pocket wheel (3), a driving sprocket (or
gear) (5)
and a retaining clip (6) (retaining clip may be replaced by riveting, for
example).
The input shaft (4) can be hexagonal in a preferred embodiment in order to
lock
in rotation both the pocket wheel (3) and the driving sprocket (or gear) (5).
The shaft
can also have a groove to receive the retaining clip (6) (if not riveted, for
example).
Regarding the overall concept of hoist allows bottom-up assembly:
The input shaft (4) can slid through bearing (14). The pocket wheel (3) can be
slid on input shaft (4), and the other frame (2) can be slid on shaft, through
its bearing.
The assembly can be locked in place with retaining clip (or riveting, for
example).
The hoist frame (2) can be made of an asymmetric part, assembled with a
bearing (14). The said frame can also have tabs (15) designed to be fold
(shown
already folded in the accompanying drawings) and thus insure a permanent
assembly
of the device.
The hoist frame can comprise an opening (12) to receive door shaft (13). The
said hoist frame can also have at least one opening (16) to receive shaft
clamp (7).
The said opening is optionally meant to be oriented in such a way so as to
help prevent
an improper assembly of the shaft clamp (7).
Setscrews (1) can be designed with a red head, for example, and designed in
a way that they will be accessible, from the top of the hoist by an installer.
As shown in the drawings, a possible embodiment of the shaft clamp (7) may
comprise at least one threaded hole (8), to receive a threaded fastener (1),
heresaid
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setscrews, that will be tightened to exert a pressure on shaft (13) and
therefore act as
a locking mean for the hoist. Once the setscrews are appropriate tightened,
the shaft
will be firmly pressed in the bottom section of frame holes (12), which
ensures good
center-to-center distance between driven mechanisms.
The present system therefore provides several advantages over conventional
devices (ex. a shaft sleeve) in that: a) the hoist is therefore locked in
translation and
in rotation on the shaft; b) translation restriction allows proper axial
alignment of the
driven mechanism (gear or sprocket) over time; c) good axial alignment and
center-
to-center distance between sprockets allows proper tension on the chain and
avoid
chain link slippage and/or premature wear; d) rotation restriction avoids
unwanted
rotation of the hoist on the shaft when load is applied on the hand chain; e)
etc.
According to another possible embodiment, the shaft clamp (7) may also be
bent at an angle (11), in order to have the axis of threads symmetrical on
each side of
the door shaft axis. This angle can also create a distinct feature that helps
in avoiding
the shaft clamp (7) from being assembled improperly onto the hoist frame (2).
The shaft clamp (7) may also comprise protrusions (9) that will guide and hold
the part vertically in hoist frame (2) during the assembly process of the
complete hoist.
The shaft clamp (7) may also comprise stamped text and/or visual indication(s)

in order to provide information to the installer on setting torque of setscrew
(1).
When the present hoist is used to manually open a door, it allows door opening
by mean of a hand chain, which when put under load rotates a pocket wheel (3).
The
pocket wheel, which is fixed to the input shaft (4), induces rotation of the
gear or
sprocket (5). This gear or sprocket (5) (i.e. "driving" component of the chain
hoist)
transmits torque to a gear or sprocket (17) (i.e. "driven" component of the
chain hoist)
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fixed on a bearing mounted drum (18). This torque allows rotation of the drum
and
opening of the door. Reduction ratio between mechanisms allows an easy opening
of
the door.
It is worth mentioning that several modifications could be made to the present
system and corresponding components, without departing from the scope of the
present invention. For example: a) preferred embodiment of the shaft clamp is
in
stamped steel, however, other combinations of material(s)/process(es) could be
used,
such as die casting, casting, machining, plastic, etc.; b) forming could be
added on
the shaft clamp to provide longer threads; c) the shaft clamp could be an
assembly of
a stamping part and/or threaded inserts; d) the number, size and type of
fixing
setscrews could vary depending of the torque to retain; e) several steel
plate(s) with
one setscrew could be used, instead of having one component with several
setscrews
assembled on it; f) the shape, location and number of protrusions into the
hoist frame
(2) could vary; g) the diameter of hole (12) could vary to accommodate
different shaft
diameters; h) the shape of hole (12) in hoist frame (2) could vary to adapt
different
door shaft (ex. hexagonal shaft, for instance); i) the hoist frame dimensions
and/or
shape could be different; j) etc.
The present shaft clamp (7) and corresponding parts are preferably made of
substantially rigid materials, such as metallic materials, hardened polymers,
composite materials, polymeric materials, and/or the like, so as to ensure a
proper
operation thereof depending on the particular applications for which the shaft
clamp
(7) is intended and the different parameters (forces, moments, etc.) in cause,
as
apparent to a person skilled in the art.
As may now be better appreciated, the present invention is advantageous in
that it provides for a shaft clamp which can be used with a chain hoist in a
more
efficient, more precise, more accurate, more reliable, more adjustable, more
versatile,
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more adaptable, more ergonomic and/or more desirable manner, than what is
possible
with other existing conventional devices.
Of course, and as can be easily understood by a person skilled in the art, the
.. scope of the claims should not be limited by the possible embodiments set
forth in the
examples, but should be given the broadest interpretation consistent with the
description as a whole.
Furthermore, although preferred embodiments of the present invention have
been briefly described herein and illustrated in the accompanying drawings, it
is to be
understood that the invention is not limited to these embodiments and that
various
changes and modifications could be made without departing form the scope and
spirit
of the present invention, as apparent to a person skilled in the art.
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