Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
This invention relates to the harnessing of items,
and more particularly, to the secure harnessing of items
to insure against their accidental release and is a divisional
application of parent Application Serial No. 172,454
filed May 28th, 1973.
Harnessing devices are widely used for the bundling
of objects. Such devices are typically formed by a serrated
strap fitted to an apertured head containing an internal
pawl that engages the serrations of the strap; or by an apertured
strap fitted to buckle-like head, with a tongue that enters
the apertures of the strap.
Harnessing devices with serrated straps have the
disadvantage of being only as secure as their pawls. Where
the items that are harnessed are heavy or are subjected to
rough handling, the items often become accidentally released,
for example, by failure of the pawls. Attempts have been
made to strengthen serrated strap devices, but this has resulted
in considerable complexity without achieving the desired end
result of providing security against accidental release of
the harnessed items. Similar objections apply to harnessing
devices with buckle-like heads. In these devices, a tongue
which enters the strap apertures rests against the head
of the buckle near its opening and is deflected by the strap.
The tongue is typically a cantilever attachment to the
buckle-like head, which tends to be unduly stiff in the
direction of forward thrust during harnessing, and insufficient-
ly stiff in the direction or reverse thrust applied by the
strap because of the harnessed items. In addition the tongue
is exposed to external interferences that can cause an
accidental release of the harnessed items.
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Accordingly, it is an object of the invention to
achieve a harnessing device for the secure harnessing of items.
A related object is to achieve secure harnessing of items
without the need for employing a complex harness configuration.
According to the parent application, the invention
claimed therein relates to a harnessing device comprising the
combination of a locking head and a guide channel extending
therethrough, a locking tang in the guide channel and an
apertured locking strap secured at one end to the locking head
and having its free end insertable into said guide channel,
said locking strap being formed of a synthetic plastic material
and being pre-stretched over at least a portion thereof
extending from said free end to a width less than that of the
guide channel, thereby to increase the length and tensile
strength of the strap for a prescribed quantity of material and
provide a strap of reduced mass for a prescribed tensile strength.
According to one broad aspect, the present invention
relates to a harnessing device comprising the combination of:
(a) a locking head having a guide channel
extending longitudinally therethrough,
an upper channel communicating with the
guide channel and superposed above the latter,
and a lower channel communicating with the
guide channel and disposed below the latter;
(b) a deflectable locking tang having its base
secured to the base of the lower channel and
having an equilibrium position with its free
end confined to said guide channel; and
(c) an apertured strap secured at one end to said
head and having its free end adapted to be
received in said guide channel and to be
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locked by engagement with said tang; whereby
(d) the free end of said tang is adapted to
be urged into the said lower channel to
permit forward movement of said strap, and
(e) the free end of said tang is adapted to be
urged against a stop associated with the
said upper channel to prevent reverse
movement of said strap.
Brief Description of the Drawings
Other aspects of the invention will become
apparent after considering several illustrative embodiments
taken in conjunction with the drawings which:
Figure I is a perspective view of a harnessing
device in accordance with the invention, being used to
harness a bundle of items;
Figure 2 is a perspective view of the head portion
of the harnessing device of Figure 1 with the upper part
broken away to show the internal construction of the head;
Figure 3A is a cross-sectional view of an alternative
harnessing device head in accordance with the invention;
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Figure 3B is a frontal view of the harnessing device
head shown in cross-section in Figure 3A;
Figure 4 is a plan view of a harnessing device in
accordance with the invention having an attached strap with
a width exceeding that of the guide channel in the head, and
Figure 5 is a cross-sectional view of~another
alternative head configuration for a harnessing device in
accordance with the invention.
Detailed Description
Turning to the drawings, Figure 1 shows a harnessing
device 10 in accordance with the invention formed by a
locking head 20 with an attached strap 30. The latter is
in the form of a ladder structure that extends perpendicular-
ly with respect to a corresponding guide channel 21 extending
longitudinally through the head 20. When a group of items 11
is to be harnessed, they are encircled by the strap 30,
and a tab 31 at the free end of the strap is inserted into
and through the guide channel 21. The strap 30 is drawn
through the locking head 20 by applying a forward thrust to it,
and an internal locking tang (not shown in Figure 1) is
deflected with respect to associated auxiliary channels 22
and 23. The locking tang successively engages rungs 32 of
the strap 30 until the items 11 are securely harnessed.
Reverse thrust produced on the strap 30 by the harnessed items
11 draws the locking tang against an internal stop (not shown)
and prevents the items 11 from becoming unbundled. The
device 10, including its head 20 and strap 30, is desirably
made out of a resilient elastomeric material or a plastic
material such as nylon.
The internal structure of the head 20 is shown in
Figure 2. The channel 21 serves as a guide for the rails
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of the strap rungs 32. Extending into the guide channel 21
is a locking tang 25, which is pivotally mounted in the
lower auxiliary channel 23. The latter is narrower than
the guide channel 21 and receives the locking tang 25 when
the strap is moved in the direction indicated by the forward
thrust arrow F. The side walls of the lower channel 22
are spaced apart to receive the locking tang 25 without
binding effect but are advantageously closely enough spaced
to prevent any undesired lateral deflection of the locking
tang.
As shown in Figure 2, the locking tang 25 is in its
equilibrium position after having been deflected into the
lower channel 23 by the forward motion of one of the rungs 32.
After the items 11 (Figure 1 ) have become securely bundled
and the forward thrust F applied to the strap is terminated,
the bundled items apply a reverse thrust by which the nearest
of the rungs 32 forces the locking tang 25 into the upper
channel 22 between narrow side walls of which one such wall 22w
is shown in Figure 2, until the'tang 25 comes into contact
with an inclined, planar stop 22s that blocks the upper channel
22.
The forward and reverse thrust movements of a
representative locking tang 251 are illustrated in Figure 3A.
The tang 251 has a blunt end that is perpendicular to the
direction of thrust, by contrast with the blunt end of the
tang 25 in Figure 2 which is parallel to the direction of
thrust. When forward thrust F-l is applied to the strap in
Figure 3A, and one of the rungs 32-1 engages the locking
tang 251, there is a component of thrust F-2 that is perpendicular
to the tang and another component of thrust F-3 along the
tang. The forward thrust F-l produces a counterwise deflection
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of the tang 251 into the lower channel 23, with the tang~
ultimately reaching the phantom position 25f. It is to
be noted that as the downward deflection of the tang into
the channel 23 increases, the perpendicular component of
thrust F-2 decreases until the deflecting rung of the
strap occupies the phantom position 32-2, after which the
natural resiliency of the tang 251 restores it to its
equilibrium position.
When the forward thrust F-l on the strap of
Figure 3A is terminated, the reverse thrust R-l exerted by
the bundled items 11 (Figure 1) causes the rung in the phantom
position 32-3 to bear against the tang 251. Ultimately,
as a result of the reverse thrust, the locking ta~g 251
occupies the phantom position 25r in abutting relationship
with the inclined planar stop 22s. In this position, the
reverse thrust R-l has a component R-2 that is perpendicular
to the stop surface 22s and another component R-3 along the
surface of the tang. In the rest or locked position of the
tang 251 the compression component R-2 is maximum. In
addition, as the tang 251 moves to the phantom position 25r,
the lever arm decreases so that the resistance of the tang to
reverse deflection increases as the deflection increases.
Thus the tang tends to resist the reverse thrust deflection
applied by the items that have been harnessed. This is
by contrast with conventional harnessing devices in which there
is no increase in counter-deflection.
As shown by Figure 3A, the locking tang 251 is
positioned within the head 20 to facilitate the forward
thrust of the strap and at the same time impede reverse
thrust. Thus, the counter-clockwise deflection of the
locking tang into the lower auxiliary channel 23 is facilitated
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by the position of the tang, while the clockwise deflection
from equilibrium caused by reverse thrust is resisted. Figure
3A also shows that the height of the guide channel 21 near the
output end exceeds the height of the channel near the locking
tang 251. This promotes the feed of the strap in the guide
channel.
In addition the walls 22w of the upper auxiliary
channel 22 can be tapered towards the end of the head
containing the inclined planar stop 22s, so that as the locking
tang 251 moves upwardly into the channel 22 it becomes
wedged between the walls 22w.
A frontal view of the locking head 20 of Figure 3A
in Figure 3B shows that when the locking tang 251 is in
equilibrium, the guide channel is fully occupied, but the
tang does not extend into the upper auxiliary channel
(not visible in Figure 3B). The portion of the locking
tang 251 which is pivotally mounted in the lower auxiliary
channel is flanked by ramp surfaces 23r. These surfaces
facilitate the entry of the rails 34-1 and 34-2 of the strap
30 into the guide channel and are of a width determined by
the extent to which an inclined ramp effect is desired at
the entrance of the locking head 20. It is to be noted that
the strap 30 which is attached to the locking head is shown
to have a neck 33 that is wider than the remainder of the
strap between the rails 34-1 and 34-2. When the harnessing
device is of nylon, the strap 30 is deliberately made
oversized. It is then stretched, except at the neck 33, to
a suitable width to permit easy entry into the guide channel
of the head 20.
A plan view of a harnessing device With an oversized
strap 30 is shown in Figure 4. As noted above, this kind
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of strap is formed when the harnessing device is fabricated
of nylon and the strap is thereafter stretched to producé
the desired ladder configuration below the head shown by
Figure 3B. Alternatively, the strap 30 of Figure 4 can be
used without being pre-stretched when the harnessing device
is fabricated of a stretchable elastomeric material. In
that event, when the tab 31 is inserted into the guide channel
21, the strap becomes stretched over the items being harnessed
by the forward thrust applied by the user. When the forward
thrust is terminated, and the harnessed items exert a reverse
thrust, there is resistance to that thrust by virtue of
the action of the locking tang 25, but there is additional
resistance to the reverse thrust between the tab 31 and
the output of the guide channel. This increases the security
of the harnessing device.
