Note: Descriptions are shown in the official language in which they were submitted.
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TETHERING APPARATUS AND INERTIA LOCKING REEL
The present invention relates to a tethering apparatus and to an inertia
locking reel.
The present invention, in so far as it relates to a tethering apparatus, has
particular
but not exclusive application to tethering apparatus which may be used to
tether a
fisherman to rocks from which he or she may be fishing. However, it will be
appreciated that the invention could also be used in other applications such
as for
tethering a workman to a ladder, scaffolding or roof to limit fall, for
otherwise tethering
a person or object to a fixture to limit accidental fall or dropping, or for
tethering a
yachtsman to a fixture on a yacht. A variety of other applications will be
apparent for
the use of the tethering apparatus of the present invention.
Fishing from rocky shorelines is a popular sport. In many instances at least
some of
the rocks are covered with marine life including algae. As a consequence the
rocks
may be slippery, particularly when wet, and wherein there always exists the
danger
that persons moving about over the rocks may slip and fall into the sea. Many
fishermen also fail to observe tide changes and, as a consequence, have been
swept
into the sea.
Workmen working at height require safety equipment to limit falls. In roofing
applications guard rails are often erected around the perimeter of the roof so
that in
the event of a fall the fallen workman will be stopped by the guard rail and
prevented
from falling further. Alternatively, and in applications where guard rails are
impractical the workman may be tethered to a fixture on a roof, ladder or
scaffolding.
Such tethers generally have a fixed length of rope which must reach its full
length
prior to arresting the fall of the workman. As a result injury may occur to
the workman
prior to, or as a result of, the sudden arrest of the fall. In order to
minimise this risk,
only short tethering ropes may be used.
We have now found a tethering apparatus which incorporates an inertia lock so
as to
almost instantly arrest the fall of a person or object. According to a first
aspect of the
present invention there is provided a tethering apparatus including a harness,
an
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anchor and a line member wherein said line member connects said harness to
said
anchor, further including a spool about which the line member is wound, said
spool
having an inertia lock for arresting the spool when the line member is unwound
from
the spool at a rate above a predetermined value.
According to a preferred embodiment of the first aspect of the present
invention there
is provided a tethering apparatus including a harness, an anchor and a line
member
wherein said line member connects said harness to said anchor, further
including a
spool about which the line member is wound, said spool having an inertia lock
wherein the inertia lock includes a housing having an inner surface in the
form of a
ratchet, and a pawl mounted for rotation about an axis substantially parallel
to and
offset from the axis about which the spool rotates and wherein said pawl is
biased to
a disengaged condition where the pawl is disengaged from the ratchet and
wherein
said pawl engages the ratchet and arrests the spool when the line member is
unwound from the spool at a rate above a predetermined value.
In a second aspect, we have now found an inertia lock which is of simple
construction
but provides an effective inertia lock suitable for a variety of applications.
According
to this aspect there is provided an inertia lock for a spool of wound tine
member
including a housing having an inner surface in the form of a ratchet, and a
pawl
mounted for rotation about an axis substantially parallel to and offset from
the axis
about which the spool rotates and wherein said pawl is biased to a disengaged
condition where the pawl is disengaged from the ratchet and wherein said pawl
engages the ratchet and arrests the spool when the line member is unwound from
the
spool at a rate above a predetermined value.
The harness may be any convenient shackle or fastener which may be attached to
the person or object to be tethered. In respect of a harness for a person,
suitable the
harness may be in the form of an article of clothing such as a pair of
trousers, a pair
of shorts, a jacket or a shirt. Alternatively the harness may be in the form
of a belt. In
applications such as for fishermen or other users in the vicinity of water the
harness
may be in the form of a life jacket or buoyancy vest.
The configuration of the harness preferably allows the line member to trail
behind the
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user. However, in certain applications, the harness may be arranged such that
the
line member extends outwardly in front of the user.
Suitable harnesses for objects include any fixture which can be attached to
the object
without causing substantial damage to the object. Preferably the harness is
releasable such that when the tethering apparatus is no longer required the
harness
may be removed and reused.
The anchor may be any convenient configuration adapted to engage a fixture
from
which ,the person or object is to be tethered. The anchor may be one or more
hooks,
karabiners or other anchors adapted to engage with various fixtures. The
anchor may
be a shackle which in use may be selectively attached to a rail or line member
such
as may have been erected specifically as an anchorage for rock fishermen and
the
like. Alternatively, the anchor may be one or more ground engaging members,
such
as a plurality of spikes which may be selectively driven into the ground or
may include
one or more fasteners which are specifically designed to expand so as to fill
a void,
such as a crack or crevice found in a rock formation. A variety of
mountaineering
equipment may be used to provide suitable anchors,
The line member is preferably a flexible member such as a rope, cable or the
like. In
the second aspect of the present invention the line member may preferably be a
belt
such as a seat belt.
The tethering apparatus includes a spool for storing or gathering selected
portions of
the line member which may not be required thereby enabling users to alter the
extended or operative length of the line member and in turn the distance
separating
the anchor and the harness. Preferably the spool is attached to or associated
with
the harness such that it is carried by the person or object. However it will
be
appreciated that in other embodiments the spool may be attached to, or located
near
by, the anchor.
The spool may provide a cylinder on which the line member may be wound. The
spool is preferably operatively connected to return mechanism. Suitable return
mechanisms may include manual operable returns such as handles drivingly
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connected to the spool for rotation, motor driven returns and biasing means,
such as
a coiled spring, whereby the spool is urged to rotate in a direction which
will gather
the line member around the spool.
The tethering apparatus of the first embodiment of the present invention
includes an
inertia lock which when operatively engaged prevents, or at least resists, the
unfurling
of portions of the line member wound on the spool. The inertia lock may be
actuated
automatically, such as in response to unintentional changes in the user's
position
which may arise as a consequence of a fall. The locking means may be actuated
should the harness' velocity relative to the anchor exceed a predetermined
value,
which may occur if the person or object falls or is being swept away by a body
of
wate r.
The inertia lock may be set to actuate when the line member is unwound from
the
spool at a rate above a predetermined value which corresponds to the action
the
tethering apparatus is designed to arrest.
Changes to the angle of inclination of the inertia lock may increase the
sensitivity of
the inertia lock and reduce the predetermined rate at which the spool is
arrested.
The inertia lock may also include facilities enabling the user to override the
automatic
locking means so as to selectively prevent the automatic actuation of same.
In the preferred embodiment of the first aspect of the present invention and
in the
second aspect of the present invention the inertia lock includes a housing
having an
inner surface in the form of a ratchet, and a pawl mounted for rotation about
an axis
substantially parallel to and offset from the axis about which the spool
rotates and
wherein said pawl is biased to a disengaged condition where the pawl is
disengaged
from the ratchet and wherein said pawl engages the ratchet and arrests the
spool
when the line member is wound from the spool at a rate above a predetermined
value.
The housing has an inner surface in the form of a ratchet. It is not narrowly
critical as
to the configuration of the ratchet other than it engages the pawl and arrests
the
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spool when the line member is wound from the spool at a rate above a
predetermined
value. In a preferred embodiment, the housing has inner surface which is
substantially cylindrical and includes a plurality of teeth to form the
ratchet.
Alternatively, the ratchet may be provided on the inner surface of the housing
in any
5 convenient configuration adapted to engage the pawl and arrest the rotation
of the
spool.
The pawl is adapted to engage the ratchet to arrest the spool. Preferably the
pawl
includes a plurality of teeth adapted to selectively engage the ratchet.
The pawl is mounted for rotation about an axis substantially parallel to and
offset from
the axis about which the spool rotates. The pawl may be mounted on a spigot or
other axle. The pawl may thus be thrown out by its own inertia as the spool
rotates.
The pawl is biased to a disengaged position where the pawl is disengaged from
the
ratchet. The pawl may be biased by a spring or other mechanism to a disengaged
position. The pawl may alternatively have an integral bias such as a member
which
is under tension or compression when the pawl is mounted on the inertia lock.
When the inertia of the pawl is sufficient to overcome the bias the pawl is
thrown
outwards from the axis of the spool and into engagement with the ratchet.
Preferably
the pawl is oriented such that its net weight is not disposed radially from
the axis of
the spool and not also disposed radially from the axis of rotation of the
pawl. In a
preferred configuration, the pawl is aligned along a chord of the cross
section of the
spool and includes a weighted portion which is not disposed radially from the
axis of
the spool and not also disposed radially from the axis of rotation of the
pawl.
The inertia lock of the second aspect of the present invention may be used in
applications other than the tethering apparatus of the first aspect of the
present
invention. The inertia lock may, for example in vehicle safety belt
application. Other
applications will also be apparent to those skilled in the art.
The inertia lock may be attached to and abut the spool or may be disposed on a
shaft
or spindle about which the spool rotates. Where the inertia lock is attached
to and
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abuts the spool the pawl may be eccentrically mounted on the spool and adapted
to
selectively engage a circular rack (or ratchet) formed on the inner surface of
the
housing.
The tethering apparatus of the present invention may be provided with multiple
line
members each having a fixed end which is secured to the attachment means and a
free end which is secured to suitable anchoring means.
In order that this invention may be more easily understood and put into
practical
effect, reference will now be made to the accompanying drawings which
illustrate a
preferred embodiment of the invention wherein the tethering apparatus is
applied to
tethering a rock fisherman to the rocks. It will be appreciated that the
application of
the tethering apparatus to other uses will be apparent to those skilled in the
art. The
inertia lock shown in the drawings illustrates a preferred embodiment of the
second
aspect of the present invention, wherein:
FIG. 1 is a schematic view showing tethering apparatus constructed in
accordance
with the present invention being used to tether a rock fisherman to a rock
formation;
FIG. 2 is a side view of a spool used in the construction of storage means for
the
tethering apparatus;
FIG. 3 is a plan view of the spool illustrated in figure 2;
FIG. 4 is a plan view of a housing used in the construction of storage means
for the
tethering apparatus;
FIG. 5 is an end view of the housing illustrated in figure 4;
FIG. 6 is a side view of the housing illustrated in figure 4;
FIG. 7 is a side cross-sectional view of a spindle used in the construction of
storage
means for the tethering apparatus;
FIG. 8 is a plan view of the spindle illustrated in figure 7;
FIG. 9 is a plan view of the spring housing used in the construction of
storage means
for the tethering apparatus;
FIG. 10 is a side view of the spring housing illustrated in figure 9;
FIG. 11 is a cross-sectional plan view showing the pawl member used in the
construction of storage means for the tethering apparatus;
FIG. 12 is a plan view of a cover used in the construction of storage means
for the
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tethering apparatus, and
FIG. 13 is a side. view of the cover illustrated in figure 12.
Figure 1 shows a rock fisherman 10 who is fishing from the edge of a rock
formation
and wherein the rocks on which he or she is standing may be covered with
marine life
including algae.
To alleviate some of the dangers associated with falling from the rock
formation into
the sea 11, the fisherman is tethered to a distant rock formation 13 located
behind
him using tethering apparatus 14.
The tethering apparatus 14 includes a harness 15 releasably attachable to the
fisherman's body, anchor 16 selectively securable to the rock formation 13 and
a line
member 17 connecting the anchor 16 to the harness 15.
The harness 15 preferably includes a belt, not shown, which may be worn around
the
fisherman's waist. For safety reasons, the belt preferably includes a quick
release
buckle whereby the fisherman may quickly remove the belt, and thereby free
himself
from the tethering apparatus should he or she so desire.
The belt also includes a spool having an inertia lock 18, mounted on a rear
portion of
the belt for storing or gathering selected portions of the line member 17
which are not
required thereby enabling the fisherman to alter the extended or operative
length of
the line member 17 and in turn the extended distance separating them from the
anchoring means 16. As shown in Figure 2, the spool having an inertia lock 18
includes a spool 19 consisting of two opposing circular guides 20 which are
connected by an intermediate sleeve 21.
As shown in Figure 3, the spool 19 is mounted on a spindle 22 and is prevented
from
rotating relative to the spindle by the abutting engagement of the flat
surface 23. As
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shown in Figure 7 the spindle 22 is mounted on a circular base 25 which
includes two
depending mountings 26 and 27.
As shown in Figure 4, the spindle 22 and the associated spool 19 are retained
within
a generally cylindrically shaped housing 30 having an internal recess 31 which
housing has in internal surface in the form of a toothed rack or ratchet 32.
The
spindle 22 is permitted to rotate about it's axis relative to the housing. As
shown in
Figure 9, the free end 28 of the spindle 22 is operatively connected to one
end of a
coiled spring, not shown, which is separately retained in a coiled or wound
state
within a cylindrically shaped housing 35 having a peripheral mounting flange
36
which enables the housing 35 to be mounted to the housing 30. The other end of
the
spring engages a slotted aperture 31 formed in a wall of the housing 35. The
biasing
forces exerted by the spring on the spindle 22, cause the spool 19 always
exhibits a
tendency to rotate in a direction which will assist with the winding up of the
line
member 17.
As shown in Figure 11, the tethering apparatus also includes an inertia lock
50 having
a pawl 37 mounted on a spigot 26 and free to rotate about same. The pawl 37
includes a free end portion 38 which is equipped with a plurality of teeth 39
adapted
to mesh with the toothed ratchet 32. The pawl 37 is connected to the mounting
27 by
a spring 52 which exerts a biassing force on the pawl 37 such that it abuts
the stop
53 when in disengaged condition.
A shown in Figures 4, 5 and 6 the housing 30 also includes a pair of mounting
flanges 40 which are used to mount the housing on the harness not shown. The
flanges 40 being reinforced by supports 41. The housing 30 also includes an
aperture 42 formed in a side wall 43 of the housing through which the line
member
contained on the spool 19 extends through during use.
Furthermore, access to the recess, and in particular the spool 19, is
selectively
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barred by the releasable attachment of a cover 44 to the upper peripheral
edges of
the side wall 43.
The inertia applied to the spool as the line member is drawn therefrom, such
as may
occur due to a fall or when being dragged out by a receding body of water, may
be
sufficient for the pawl to overcome the biasing forces applied to same by the
spring
52 and to operatively engage the ratchet 32. Thus, it will be appreciated that
the
tethering 10 apparatus may be used to secure a fisherman equipped with same to
a
fixed object, such as a rock formation, and wherein no additional line member
shall
be dispensed should the fisherman fall and/or become immersed in a body of
receding water. As a consequence the risks of the fisherman being plunged into
the
sea and possibly drowning are reduced.
It will be appreciated that the storage means may be used in other
applications where
the selective dispensing of a line member is desirable. It is to be
appreciated that the
above has been given only by way of illustrative example of the invention and
that all
such modifications and variations thereto as would be apparent to persons
skilled in
the art are deemed to fall within the broad scope and ambit of the invention
as is
herein defined in the appended claims.
