Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02608049 2007-10-17
CLIP SYSTEM FOR USE WITH TARPS AND
OTHER FLEXIBLE SHEET MATERIAL
BACKGROUND
a. Field of the Invention
The present invention relates generally to clips and similar gripping devices,
and, more particularly, to a thumbscrew-operated clip for gripping the edges
of tarps
formed of plastic, cloth or other flexible sheet material.
b. Related Art
The problem of how to secure a tarp against environmental conditions is one
of long standing. By their very nature, tarps are intended for use as
protection against
the weather and are therefore often subjected to high winds. This is true not
only in
stationary installations, but also where a tarp is used to cover a load on a
moving
vehicle, such as over a truck bed or rail car.
For years, many tarps have been provided with grommets along their edges to
provide attachment points for ropes or other hold-down lines. This adds
significantly
to the cost of manufacturing the tarp, and unfortunately offers only a partial
solution.
For example, the grommets sometimes tear out of the edges of the tarp, which
can
render the tarp useless unless some other means can be found for attaching tie-
down
lines to its edges. Furthermore, the grommets are ordinarily provided only at
widely
spaced locations (e.g., at spacing of perhaps three feet or so), which makes
it difficult
or impossible to attach additional hold-down lines at other points where they
may be
needed in order to provide a tight fit or to resist wind forces.
Still further, some tarps are not provided with any grommets at all such as
VISQUEENTM and similar plastic sheeting, for example, which makes it extremely
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2
difficult to secure these in place. Users have resorted to the expedient of
passing
ropes or shock ("bungee") cords over the tops of the sheeting and/or weighting
them
with bricks, cinder blocks, pieces of wood and similar objects, which is
neither secure
nor practical in many circumstances.
A number of clip-like attachment devices have been proposed in prior art,
principally for use with clothing and woven fabric material. For example, the
traditional "suspender clip" uses a pair of metal jaws that are forced
together by a
clasp mechanism. The sharp, pointed jaws of these devices tend to cause
excessive
damage and wear to the fabric, and are simply incapable of firmly gripping
plastic
sheeting or other comparatively thin material without tearing or destroying
it. This
tendency is complicated by the fact that, due to the nature of the clasp
mechanism,
this type of clip can only exert a fixed amount of gripping force between the
jaws, i.e.,
the grip cannot be adjusted to be either tighter or looser, as may be needed
in
particular instances or for use with certain materials. Furthermore, the metal
"suspender clip" devices are subject to breakage and rapid wear, and are
difficult to
operate when wet and cold.
The locking clip disclosed in U.S. 5,388,313 (Cameron) addresses a number of
these issues, and is highly effective for many applications. However, the
toothed
ramp mechanism of this device limits the clamping force to a predetermined
range
(i.e., between finite upper and lower limits), whereas in some instances it
may be
desirable to be able to exert a greater or lesser degree of clamping force
against the
material; for example, when used with certain very thin, slippery or wet
materials, it
may be desirable to exert a much higher degree of clamping force in order to
establish
a firmer grip on the material. Furthermore, the teeth on the device in the
'313 patent
are shown mainly as having the configuration of a series of transversely
extending
ridges or corrugations; again, while this configuration is very effective for
use with
many types of materials, other materials may have a tendency to either slip
through or
tear between the ridged teeth, particularly if forces are applied in a
somewhat
crosswise direction with respect to the jaws of the clip.
Other clip designs have provided another partial solution by utilizing a
"screw
together" clamping action, in which operation of a thumbscrew-like mechanism
forces the jaws together. Some such clips have been formed of metal, and
others have
been made of molded plastic. While some of these clips have been proven
reasonably
effective, their designs have generally relied on the resilience of the
material to return
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3
the jaws to an open position upon loosening of the screw mechanism: With metal
clips, material fatigue leads to lessening or failure of the opening action
over time;
plastic clips, on the other hand, often exhibit a weak and less than positive
opening
action. Moreover, material and design factors typically limit the resilient
opening
action to a certain, maximum spread between the jaws, so that it is difficult
or
impossible to expand the opening further if necessary, e.g., in order to fit
over several
layers of material that have been bunched together.
Another, pronounced drawback of previous clips is that they are generally able
to attach only one kind of article; in particular, most clips are capable of
attachment to
ropes or other type of cords. Ropes and cords are indeed perhaps the most
common
things that users use to attach to tarps, however, there are many other items
and
fixtures that may be beneficially attached to a tarp, particularly for certain
relatively
specialized purposes. A few clips have been designed with attachment features
that
allow them to be connected to more than one kind of cord (for example, for
attachment to a bight of a rope and also to a hook on bungee cord), but not to
other
load-bearing/transmitting articles. Moreover, the cost of having to tool
entire molds
for use with different, sometimes specialized attachments can be economically
prohibitive for the manufacturer.
Yet another difficulty with previous tarp clips has been their inability to
accommodate twisting of the rope or fixture, which is often caused by wind and
other
environmental forces to which the ensemble is exposed. As a result, the clips
tend to
damage the material of the tarp by twisting and working against it, sometimes
to the
point of ripping out of the edge of the tarp.
Accordingly, there exists a need for an improved form of clip apparatus which
permits an expanded range of grip forces to be exerted against sheet material
between
the jaws thereof, and which permits a comparatively high grip force to be
exerted
when desired. Furthermore, there exists a need for such a clip apparatus that
is
capable of accommodating tarps and materials having a variety of thicknesses.
Still
further, there exists a need for such a clip apparatus having an arrangement
of teeth,
which enables the apparatus to establish effective engagement with thin, slick
or
otherwise hard to grip sheet material. Still further, there exists a need for
such a clip
apparatus that will minimize damage to the fabric, plastic or other tarp
material with
which it is used. Still further, there exists a need for such a clip apparatus
which can
be adapted for attachment to a variety of load-bearing members and fixtures,
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4
including and in addition to ropes and cords. Still further, there exists a
need for such
a clip apparatus that can accommodate relative turning and twisting motion of
a rope
or other attachment, without twisting against and causing damage to the
material of
the tarp. Still further, there exists a need for such a clip apparatus which
is reliable
and durable, and which is economical to manufacture.
15
25
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SUMMARY OF THE INVENTION
5
The present invention has solved the problems cited above, and is a clip
system for use with tarps and other flexible sheet material.
In a broad aspect, the system comprises: (a) a clip body comprising first and
second jaw members, and means for adjusting the gap between the jaw members so
as
to selectively grip and release a tarp therein; (b) at least one attachment
fitting for
engaging an article or fixture separate from the tarp; and (c) means for
rotatingly
mounting the attachment fitting to the clip body, so that the attachment
fitting and clip
body are free to twist independently of one another.
The at least one attachment fitting may comprise a plurality of different
attachment fittings that are interchangeably mountable to the clip body. The
means
for mounting the at least one attachment fitting to the clip body may comprise
a male
coupler and a female receptacle that receives the coupler in locking
engagement
therewith. The male coupler may be formed on the attachment fitting and the
female
receptacle may be formed on the clip body.
The male coupler may comprise a boss having an annular bearing face, and a
plurality of resiliently flexible legs extending substantially normal to the
bearing face,
the flexible legs each having an end portion comprising an outwardly sloped
ramp
portion and an undercut notch portion. The female receptacle may comprise a
boss
having an internal bore that reacts with the sloped ramps of the flexible legs
of the
male coupler so as to compress the legs inwardly as the end portions thereof
are
pressed into the bore, an opening on a rearward side of the boss that permits
the legs
to expand back outwardly after passing through the bore so that the undercut
notches
thereon form a locking engagement with the rearward side of the boss, and an
annular
bearing surface on a forward side of the boss that meets the annular bearing
surface of
the male coupler in face-to-face engagement so as to form a bearing interface
for
independent rotation of the attachment fitting and clip body.
The at least one attachment fitting may comprise a hook for attachment to a
rope, cord or rod-shaped article. The at least one attachment fitting may also
comprise a screw-on fitting for attachment to a bottle, jug or other container
filled
with liquid to provide a weight. The at least one attachment fitting may also
comprise
a fitting for attachment of a strap or shock cord.
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6
The clip body may further comprise a live hinge that joins the first and
second
jaws at a base end of the body. The means for adjusting the gap between the
first and
second jaws may comprise a finger-operated screw adjustment mechanism. The
finger-operated screw adjustment mechanism may comprise a screw member having
a
threaded shaft section in engagement with at least one of the jaws. The screw
member may comprise a first end that is in non-threaded engagement with a
first one
of the jaws, a threaded shaft section that is in engagement with a second one
of the
jaws, and a second end that protrudes beyond the second jaw on a side opposite
the
first jaw. The screw adjustment mechanism may further comprise a finger-
operable
knob that is mounted to the projecting end of the screw member.
The clip body may further comprise a plurality of teeth formed on a first one
of the jaws, and a plurality of cooperating recesses formed in the second one
of the
jaws into which the material of a tarp is pressed by the teeth so as to form a
gripping
engagement therewith. The plurality of teeth may comprise a plurality of
corresponding, pyramidally-shaped teeth and the recesses may comprise a
plurality of
pyramidally-shaped sockets. The pyramidally-shaped teeth may comprise
flattened
tips so as to avoid piercing the material of the tarp. The teeth and sockets
may be
arranged in a series of rows that extend transversely across the first and
second jaws.
These and other features and advantages of the present invention will be more
fully appreciated from a reading of the following detail description with
reference to
the accompanying drawings.
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7
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 A is a plan view of a clip body and load attachment fitting, in
accordance with the present invention;
FIG. 1B is a second plan view of the clip body and load attachment fitting of
FIG. IA, showing the load attachment fitting joined to the clip body to form a
complete clip assembly, and also showing the manner in the load attachment
fitting is
free to rotate relative to the clip body without transmitting twisting forces
to the latter;
FIG. 2A is a plan view similar to FIG. 1 A, but showing the clip body only in
part view, illustrating the manner in which a second load attachment fitting
having an
enlarged hook can be mounted to the clip body in place of the first load
attachment
fitting that is shown in FIGS. 1 A-1 B;
FIG. 2B is a plan view of a third example attachment fitting that can be used
with the clip body of FIGS. 1 A-1 B, namely a screw-on cap for a comparatively
large
bottle that can be filled with water or other liquid to form a weight for the
edge of a
tarp;
FIG. 2C is a plan view of a fourth example attachment fitting that can be used
with the clip body of FIGS. 1 A-1 B, namely a screw-on cap for a relatively
small
bottle that can likewise be filled with water or other liquid to form a
weight;
FIG. 2D is a plan view of a fifth example attachment fitting that can be used
with the clip body of FIGS. IA-IB, namely a rigid base and elongate strap
having a
plurality of openings that enable it to be looped back and attached to a
projecting
hook on the base;
FIG. 2E is a plan view of a sixth example attachment fitting that can be used
with the clip body of FIGS.IA-IB, namely an adjustable attachment for a flat
cross-
section shock cord;
FIG. 3 is a cross-sectional view of the attachment fitting of FIG. 2, showing
the structure thereof in greater detail, and also of an exemplary hook member
mounted to an opposite end of the flat cross-section cord;
FIG. 4 is a plan view of an attachment fitting having a male mounting
structure the same as the example attachment fittings of FIGS. IA-2E, and of a
hook
member having a female mounting structure the same as the clip body of FIGS. 1
A-
IB, showing the manner in which the attachment fittings of the present
invention can
also be used with a variety of bodies having non-clip configurations;
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. g
FIG. 5A is a top plan view of the clip body of FIGS. IA-1B, with the screw
adjustrnent mechanism being removed, showing the structure thereof in greater
detail;
FIG. 5B is a bottom plan view of the clip body of FIG. 5A;
FIG. 6 is an elevational, exploded view of the clip body of FIGS. lA-1B,
showing the manner in which the components thereof are assembled to form the
body;
FIGS. 7A-7B are side elevational views of the clip body of FIGS. IA-1B,
showing the manner in which the jaw members collapse towards one another as
the
screw adjustment mechanism is tightened, so that the coordinating gripping
surfaces
thereof come into generally parallel engagement so as to grasp the material of
the tarp
therein;
FIGS. 8A-8B are plan views of the tarp engagement surfaces of the clip body
of FIGS. 7A-7B, showing the cooperating pyramidal teeth and sockets that form
the
gripping surfaces in greater detail;
FIG. 9 is an elevational, environmental view of an example use of the clip
assembly of FIGS. 1A-1B, namely to suspend a tarp from a rope;
FIG. 10 is an environmental view of an example use of the clip assembly
made up of the clip body with the attachment fitting of FIG. 2C, namely to
suspend a
plurality of filled bottles as weights about the hem of a cover over a boat;
FIG. 11 A is a plan view of a clip body and load attachment fitting, in
accordance with another embodiment of the present invention in which the
female
receptacle includes a center plug that prevents the legs of the male connector
member
from deforming inwardly and accidentally disconnecting after assembly;
FIG. 11 B is a second plan view of the clip body and load attachment fitting
of
FIG. 11A, showing the load attachment fitting joined to the clip body to form
a
complete clip assembly; and
FIG. 12 is a cross-sectional view of a hook piece having a female receptacle
with a center plug that prevents the legs of the male connector from bending
inwardly
after assembly, similar to the embodiment of FIGS. 11A, but in which the plug
is
biased by a zigzag or accordion-shaped section of plastic that provides a
spring
structure having enhanced travel and resilience.
DETAILED DESCRIPTION
Reference will now be made in detail to the preferred embodiments of the
present invention, examples of which are illustrated in the accompanying
drawings,
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= 9
wherein like reference numerals refer to like elements throughout. As used in
this
description and the appended claims, the term "tarp" includes all flexible
sheet
coverings made of material of any kind, whether of a woven or non-woven
construction.
As will be described in greater detail below, the present invention provides a
clip system in which a variety of attachment fittings can be used with a
single form of
clip body, for attachment to a variety of different loads, fixtures and load-
bearing/transmitting members, in addition to and including ropes and cords.
Moreover, the clip bodies and attachment fittings are free to rotate relative
to one
another, thus avoiding damage to the tarp or other sheet material in the event
that the
attachment fitting is subjected to twisting forces due to wind or other
causes. Both
components are economically and durably formed of a molded plastic material,
such
as glass filled nylon material.
Accordingly, FIG. 1 shows first and second clip components in accordance
with the present invention, namely a clip body 10 and an attachment fitting
12. As
will be described in greater detail below, the clip body 10 includes first and
second
jaws 14a, 14b (14a only being visible in FIG. 1A) that are joined at the base
by a live
hinge 16. The gap between the jaws is adjusted by a screw mechanism 20; as
will be
described in greater detail below, the screw adjustment mechanism of the
preferred
embodiment adjusts the opening between the jaws in both directions (i.e., both
clamping together and spreading apart) in a positive manner, depending on the
direction of rotation of the thumb operated knob 22.
The base of the clip body (at the end opposite the jaws 14a, 14b) includes a
female receiver 24 formed by a ring-shaped boss 26 and axial bore 28. The boss
is set
away from the live hinge and main portion of the clip body, on legs 30a, 30b,
with an
opening 32 being formed on its rearward side. The attachment fitting 12, in
turn,
includes a male coupler 34 having a circular boss 36 that corresponds to that
of the
female receptacle 24. A plurality of resiliently flexible legs 38 extend
longitudinally
from the face the boss 36, in a circular array that is sized to be received
within the
bore 28 of the female receptacle; the coupler of the illustrated embodiment
includes
four of the flexible legs, which has been found to be an eminently suitable
number,
however, it will be understood that more or fewer legs may be used in some
embodiments, depending on design factors. As can be seen, the distal ends of
the legs
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= 10
include outwardly and rearwardly sloped ramp portions 40, that extend over
undercut
notches 42 on the outer sides of the legs.
The circular array of legs 38 surrounds an open center, so that the legs can
flex
inwardly without obstruction. The ramps 40 on the ends of the legs thus form a
taper
that reacts against the entrance to bore 28 so as to flex the legs inwardly
towards one
another, in response to the male coupler being forced into the female
receptacle in a
direction indicated by arrow 44. Upon passing through the bore so that the
notches 42
reach the opening 32, the legs resiliently expand back outwardly (radially) so
as to
position the notches against the rearward face 46 of boss 26, thus locking the
clip
body and attachment fitting together as an assembly. Moreover, the tapered
ramps on
the legs produce a self-centering action so that assembly requires only a
quick motion
of the two pieces in a longitudinal direction as shown in FIG. 1 A, enhancing
both
economy and ease of use.
The main portion 48 of the legs (the portions between the notches 42 and the
forward face 50 of the circular boss 36) is sized just slightly longer than
the thickness
of the ring-shaped boss 24, so that when the legs snap back out to lock the
pieces
together, the forward face 50 of boss 36 is retained in closely-spaced
parallel
relationship with the corresponding face 52 on the other boss 24. The faces
50, 54,
46, and the undercut notches 42, thus cooperate to form a series of generally
annular,
relatively broad bearing surfaces, that provide the clip assembly with
structural
integrity and resistance to bending, while at the same time permitting the
attachment
fitting and clip body to rotate relative to one another about the longitudinal
axis of the
assembly, as indicated by arrow 56 in FIG. 1 B. This rotating action prevents
transmission of twisting forces from the attachment fitting to the clip body,
thus
avoiding the latter twisting and working against the material of the tarp.
FIGS. 11A-11B show the corresponding components of a clip assembly in
accordance with another embodiment of the invention, that includes an
additional
feature to further ensure against accidental detachment of the components
after
assembly.
In the embodiment that is illustrated in FIGS. 11A-I 1B, the components of the
male coupler 34 are the same as before, i.e., there is a circular boss 36
having a
plurality of longitudinally extending, resiliently flexible legs 38. As
before, the legs
have tapered ramps 40 on their distal ends that react against the entrance to
the bore
28 of the female receptacle, thus causing the legs to deflect inwardly so as
to be able
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= 11
to pass through the bore. The female receptacle likewise includes the circular
boss 26
and opening 32 into which the ends of the legs expand. Additionally, however,
a plug
member 300 extends axially into the center of the receptacle from the end wall
302 of
the opening. A transverse slot 304 is formed behind the end wall 302, on the
side
opposite the plug 300, so as to form a relatively thin, flexible transverse
bridge
portion 306.
The center plug 300 has a diameter sized to closely match the diameter of the
opening between the ends of the circular array of legs, with the result that
when the
legs are compressed inwardly their ends define an inside diameter smaller than
that of
the center plug. Thus, as the two components 10, 12 are pressed together in
the
direction indicated by arrow 308 in FIG. 11A, the ends of the legs pass
through bore
28 and come into contact with the center plug 300. Continued force then causes
the
bridge piece 306 to deflect resiliently, in a manner similar to a spring, so
that the
center plug is pushed ahead of the legs, in a direction towards the jaws of
the clip
body. With further movement the undercut notches 42 of the legs reach the
opposite
side of boss 26, so that the legs are released to expand outwardly. As this
happens the
bridge piece 36 simultaneously biases the center plug 300 back towards its
original
position, so that the plug becomes nested within the central opening of the
circular
array of legs, as shown in FIG. 11 B. In this position, the center plug
prevents any
subsequent inward movement/deflection of the legs, thus obviating the
possibility of
the components being accidentally separated by tension or a bending action.
It will be understood that other mechanisms may be utilized in place of or in
combination with the bridge piece 306 to bias the center plug 300 towards the
locking
position; for example, other forms of springs (formed integrally with the body
or not)
or elastomeric members may be used. For example, FIG. 12 shows an attached
fitting
310 (a hook) having a female receptacle with a central plug 314 that is biased
into
position by a zigzag or accordion-shaped portion of the plastic material, that
forms a
spring structure having greater travel and resilience than the straight bridge
piece 306
shown in FIGS. 11A-B. Furthermore, it will be understood that other structures
may
also be used for enhanced engagement between the components, such as angled
(or
hook-shaped) undercuts on the ends of the legs that engage a cooperatingly
tapered or
beveled collar or ring about the perimeter of opening 32.
In the embodiment that is illustrated in FIGS. 1 A-1 B, the attachment fitting
12
includes a body 60 having a hook portion 62 formed on its end opposite the
male
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= 12
coupling 34. The hook defines an opening 64 for receiving a rope or other
cord; the
assembly may therefore be used, for example, to attach a relatively small rope
or cord
to a tarp. FIG. 2A, in turn, shows a second attachment fitting 68 having a
body 70
with a relatively larger clip portion 72 at its end, that defines an opening
74 for
receiving a larger rope or article, such as a branch or rod. The body also
includes a
hole 76, e.g., for receiving the hook of a sock cord or the like. As can be
seen, the
second attachment fitting 68 includes a male coupling 34, having a boss 36 and
legs
38, that is identical to the male coupling of the first attachment fitting 60
described
above. The second attachment fitting 68 therefore mounts to an identical clip
body 10
in the same manner as previously described, i.e., with a simple longitudinal
insertion
of the male coupler into the female receiver, as indicated by arrow 78 in FIG.
2A.
FIGS. 2B-2E show additional examples of attachment fittings that are
mountable to identical clip bodies in the same manner; it will be understood
that some
embodiments may have attachment fittings with differing or additional
configurations.
FIGS. 2B and 2C show attachment fittings 80, 82 that serve to connect bottles
or similar containers to the clip bodies, so that the bottles can serve as
weights when
filled. The first fitting 80 in FIG. 2B is configured for attachment to a
relatively large
container, e.g., a one gallon jug 84. The attachment fitting includes a
cylindrical boss
86 having internal threads that are sized and configured to engage the threads
88 on
the neck of the jug, in order that they can be connected as indicated by arrow
90.
Flexible legs 38 identical to those described above protrude from the opposite
side,
and are surrounded by an annular surface 92 that corresponds to the forward
surface
50 of the boss 36 described above, and that likewise cooperates with the
surface 54 of
the clip body to form a bearing surface. The attachment fitting 82 shown in
FIG. 2C
is substantially the same as that in FIG. 2B, except for being sized for
attachment to a
smaller bottle, such as a two liter soda bottle 94. Accordingly, the
attachment fitting
also includes an internally threaded boss 96 that mounts to the cap threads 98
of the
bottle, as indicated by arrow 100, and an annular forward surface 102 that
surrounds
the array of flexible legs 38.
FIG. 2D shows an attachment fitting 104, with a male coupler 106 formed by a
cylindrical boss 108 and legs 38 similar to those described above, to which an
elongate strap member 110 is mounted. The strap member includes a plurality of
longitudinally-spaced holes 112, similar to those of a belt, which are sized
to receive a
curved hook 114 that projects from the perimeter of the connector boss 108.
The
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13
strap member 110 is preferably formed of an elastic material, such as rubber,
for
example. The strap can therefore be wrapped around an article or articles
(e.g., a
bundle of sticks), and its free end 116 of the strap then stretched taut so
that the hook
114 can be passed through one of the holes 112 to secure the article or
articles to the
fitting.
FIG. 2E shows an attachment fitting 120 that again includes a male coupler
122 formed by a circular boss and projecting legs, as described above. In this
embodiment, the fitting includes an adjustable connector 126 that receives a
flat-
section cord therein; the elastomeric cord is suitably a conventional flat
cross-section
shock (bungee) cord having a braided cover.
The connector 126 includes a channel 130 having sidewalls 132 spaced apart a
sufficient distance that the cord will lie flat against the bottom wall 134 of
the channel
when inserted therein. The free end of the cord is looped over a movable
transverse
bar 136, that is slidingly received in guide slots 138 formed in the sidewalls
of the
channel, and then back under a stationary stop bar 140 that is formed across
the outer
end of the channel.
Thus, when the movable bar is slid towards the male coupler, to the position
shown in FIG. 2E, the cord is freed so that its length can be adjusted, e.g..,
by feeding
additional cord under the movable bar and back out the end of the channel.
When
tension is then applied to the cord, as indicated by arrow 142 in FIG. 2E, the
transverse bar 136 slides back within slots 138 to crimp the cord against the
stationary bar 140, locking the cord in place and preventing it from slipping
through
the fitting. The cross-section of FIG. 3 thus shows the movable bar 136 drawn
into
position to crimp the cord against the stationary bar 140, where it will
remain until the
user either slides the bar forward by grasping its ends between his fingers,
or by
forcing the cord back up through the open end of the channel.
FIG. 3 also shows a hook member 144 that may optionally be mounted to the
opposite end of the cord 128. As can be seen, the hook member includes an
elongate
shank 146, with an enlarged base portion 148 having a bore 150 that extends
generally parallel to the long axis of the shank. A cord 128 is threaded
through the
bore from the base end, with the bore having a generally flat cross-section
that closely
corresponds to that of the cord; the free end of the cord is then made secure
against
the sliding back through the passage, for example, by being bent over and
clipped or
otherwise secured as shown at 152 in FIG. 3. A hook portion 154 is formed at
the end
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14
opposite the base portion 148, with the tip 156 of the hook extending back
generally
parallel to the shank 146. Passage 150 thus holds the captured end of the flat
cross-
section cord generally parallel to both the shank and the end of the hook;
which has
the effect of maintaining the hook in its proper alignment when the cord
stretches and
elongates under a load, keeping the article to which the hook is attached
(e.g., a rope,
branch, etc.) generally centered in the opening 158 of the hook and preventing
accidental dislodgement.
FIG. 4 shows an assembly 160 in which there is an attachment fitting 162
having a male coupler 164 formed by boss 166 and legs 38, in the manner
previously
described. In this example, the boss is attached to an elongate strap 168,
however, it
will be understood that the attachment fitting may have other configurations,
including those described above.
In the embodiment shown in FIG. 4, the attachment fitting connects to a hook
member 170, rather than to a clip body. The hook member, similar to the clip
bodies,
includes a female receiver 172 having a boss 26, bore 28 and opening 32 that
are
identical to those described above, so that the coupler and receptacle can be
joined in
the same manner, i.e., by pressing them together in the direction indicated by
arrow
174. In this instance, however, the receptacle 172 is formed at the base of a
body 176
having a hook 180 at the other end and an opening 182 (similar to the hook
member
of FIG. 2A), instead of a clip. FIG. 4 thus demonstrates the versatility of
the system
of the present invention, in which the components and connectors provided for
the
clip assemblies can also be used with other types of attachments.
As noted above, a wide range of attachment fittings may be provided for use
with the clip bodies in the system of the present invention, in addition to
the examples
described above. Moreover, it will be understood that the coupling mechanism
may
vary somewhat depending on design factors; for example, in some embodiments
the
male/female couplers may be reversed between the clip bodies and the
attachment
fittings, the number and shape of the legs may differ somewhat, the opening 32
may
be an enclosed cavity, and so on.
FIGS. 5A-5B and 6 show the construction of the clip body 10 in greater detail.
As can be seen in FIGS. 5A-5B, the upper and lower jaws 14a, 14b, live
hinge 16, and receptacle 24 are all formed as integral features of a single,
molded
structure 184, which (as noted above) is suitably formed of glass reinforced
nylon or
CA 02608049 2007-10-17
5 other resiliently flexible plastic material having good memory and
durability
characteristics.
The outer surface of the upper jaw 14a (for ease of discussion, the jaw
towards
the finger-operated nut of the screw adjustment mechanism will be referred to
as the
"upper jaws", but it will be understood that the actual orientation and
relationship of
10 the parts may be reversed or otherwise differ from what is shown) includes
an
opening into an internally threaded bore 186 that is surrounded by a flat,
annular
bearing surface 188. First and second small pegs or teats 190a, 190b protrude
upwardly a short distance above the annular surface, on opposite sides of the
bore
186.
15 The lower jaw 14b, in turn, includes a recessed, annular socket 192 that
surrounds a second bore 194. As can be seen in FIG. 6, bore 194 is coaxially
aligned
with the bore 186 in the upper jaw 14a. Screw member 200 is inserted through
the
unthreaded bore 194 of the lower jaw and then threaded into the upper bore
186, so
that the threaded shaft section 202 of the screw member forms a cooperating
engagement with the latter. A square shaft end 203 of the screw member
protrudes
above the upper surface of jaw 14a, and is received in a cooperating, square
bore 206
in the hub 204 of the finger-operated knob member 22. As the knob member is
pressed onto the shaft end, inwardly-projecting teeth 208 within bore 206
engage
correspondingly shaped notches 210 in the shaft end so as to lock the two
pieces
together.
At its lower end, the enlarged, circular head 212 of the screw member is
received in the socket 192 of jaw 14b. As can be seen in FIG. 6, the head end
of the
shaft of the screw is provided with a transverse, lengthwise slit opening 214,
that
allows the sides of the shaft to flex inwardly in this area, and a raised,
annular ridge
216 formed at the lower end of the threads. The distance between the ridge 216
and
the head 212 of the screw member is slightly greater than the thickness of the
thin
material between the end wall of the recess 192 and the inside surface 218 of
the
lower jaw 14b. The screw member is thus installed by pressing the head 212
upwardly into the socket 192, so that the sides of the screw flex inwardly to
allow the
ridge 216 to pass through bore 194. Upon reaching the inside surface 218 of
the
lower jaw, the sides of the screw expand back outwardly so that the
longitudinal
position of the screw member is locked in relationship to the jaw. The shaft
section
218 that resides in bore 194 is non-threaded, so as to rotate smoothly and
freely within
CA 02608049 2007-10-17
16
the bore; the annular undersurface 220 of the screw head 212, in turn, bears
against
the bottom wall of recess 192 to form a horizontal bearing surface.
The opening between the jaws is thus adjusted by turning knob 22 by hand,
with the fingers pressing against the wings or ears 222 on the knob. Turning
the knob
a first direction (e.g., clockwise) draws the jaws together: The threaded
shaft second
202 cooperates with the internally threaded bore of the upper jaw to shorten
the
distance between the latter and the lower jaw, which is retained by the head
212 of the
screw. Turning the knob the opposite direction spreads the jaws apart; as the
length
of the screw below the upper jaw increases, the ridge 216 reacts against the
inside
surface of the lower jaw so as to widen the opening in a positive manner and
as far as
needed.
When the jaws are being tightened, the teeth 224 on the upper jaw enter
cooperating depressions 226 in the lower jaw. As can be seen in FIG. 7A,
contact
first occurs at the tips of the jaws, so that the distal rows of teeth and
sockets are the
first to engage the tarp. Further tightening of the screw mechanism causes the
middle
portions of the jaws (the portions between the teeth and the live hinge 16) to
collapse
together resiliently, so that the remaining rows of teetli/sockets engage
sequentially
and the jaws flatten out to reach a more or less parallel orientation, as
indicated by
arrows 228a, 228b in FIG. 7B. Upon loosening of the screw mechanism, the jaws
bend apart to release the teeth/sockets in a reverse sequence, from the back
towards
the tips of the jaws. The outer surfaces of jaws are provided with lengthwise
strengthening ribs 230a, 230b and 232a, 232b (see FIGS. 5A-5B) along their
edges,
which ensure the two jaws collapse and spread apart resiliently as described.
The sequential engagement of the jaws provides several advantages; in
particular the ability to exert a strong, evenly distributed gripping force
against
materials of varying thicknesses, e.g., whether a single layer of a tarp or
several layers
folded over or bunched together. By comparison, conventional jaws having a
fixed
angle tend to spread apart towards their tips if the material is overly thick,
while with
thinner materials they tend to spread apart towards the base.
Furthermore, the teeth and depressions 224, 226 have profiles that establish a
strong, non-slip grip against the tarp without damaging its material. As can
be seen,
the teeth are substantially pyramidal in shape, with four angled sides meeting
at
pronounced corners, while the depressions have a corresponding pyramidal
configuration. When the material of the tarp is pressed into the depressions
by the
CA 02608049 2007-10-17
17
teeth, the cooperating edges and flats bend the material through multiple
angles so as
to obviate any possibility of slippage, without cutting into or otherwise
damaging the
fibers or other material of the tarp. Moreover, as can be seen, the teeth are
provided
with flattened rather than pointed tips 230, obviating any possibility of
puncturing the
material of the tarp.
FIGS. 9-10 illustrate two exemplary uses of hook assemblies in accordance
with the system of the present invention. FIG. 9 shows use of a clip assembly
240
made up of the clip body 10 and attachment fitting 12 of FIGS. lA-1B. In this
example, the jaws of the clip body grip the edge of a tarp 242, while the hook
of the
attachment fitting is placed over a rope 244 so as to suspend the tarp from
the latter.
FIG. 10, in turn, shows exemplary use of a series of clip assemblies 250 made
up of
the clip bodies 10 of FIGS. 1 A-1 B and the bottle attachment fittings of FIG.
2C, to
weight the hem of a cover 252 over a boat 254 using filled soda bottles 94.
Again, it
will be understood that virtually unlimited additional applications exist,
given the
wide range of attachment fittings that may be used.
It will be understood that other embodiments of the present invention may
employ jaw portions, teeth, thumbscrew mechanisms or other components that
vary
somewhat from the preferred embodiments shown and described herein. It is
therefore to be recognized that various alterations, modifications and/or
additions may
be introduced into the constructions and arrangements of parts described above
without departing from the spirit or ambit of the present invention as defined
by the
appended claims.
