Note: Descriptions are shown in the official language in which they were submitted.
1 177~2~
This invention is concerned wlth a one-piece plastic strap
comprising an elongated flexible portion having teeth formed along a
surface of at least a portion thereof, and a locking device defining
a slot into which a ~ree end of the flexible portion can be introduced
and locked in the slot so that the strap forms a retaining loop, the
slot of the locking device being defined by a base portion of the
locking device, two parallel leg portions extending from the base portion,
and a pawl portion integral with and supported by the leg portions for
` pivoting movement therebetween, the pawl portion comprising a locking
portion arranged to interengage one or more of the teeth of the flexible
portion within the slot thereby locking the flexible portion against
movement relat1ve to the slot, and an engagement portion engageable
to cause the pawl pOrtiGn to pivot between the leg portions so that
the interengagement of the locking portion and the teeth is released.
When one-piece plastic straps as described above are used, it is
desirable that the pawl portion should maintain its interengagement
with the teeth until positively released so that the strap will not
come accidently undone. However, it is also desirable that the strap
should be easily undone when required. Existing straps are often
difficult to undo because, when pressure is applied to the engagement
portion of the pawl portion, rather than the pawl portion pivoting
relative to the leg portions, the whole locking device moves with the
flexible portion flexing without the pawl portion releasing its
interengagement.
It is an object of the pre~sent invention to provide a strap
which is easier to undo than existing straps.
The invention provides that the locking device also comprises a
- bracing portion in opposed relationship to the engagement portion of
the pawl portion, the bracing portion being rigidly connected to the
leg portions thereby providing that, when the engagement portion of
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pawl portion and the bracing portion are pressed together, the pawl
portion pivots releasing the interengagement of the locking portion and
the teeth.
In order to increase the ease with whlch the strap can be undone,
the bracing portion comprises two lugs, one on each side of the
engagement portion of the pawl portion, the engagement portion being
movable to a position between the lugs to pivot the pawl portion.
The invention gives the advantage that the strap is easier to undo
than existing straps. In particular, the engagement portion and the
bracing portion can be squeezed between the thumb and first finger
to undo the strap.
An example of the embodiment of the invention is shown in the
accompanying drawings, and is described in greater detail below:
In the drawings:
Figure 1 is a side elevational view, partly 1n section, of a
strap in accordance with the invention showing the strap forming a
retaining loop;
Figure 2 is a longitudinal cross-section view of the strap shown
in Figure 1 showing it in a straightened condition; and
Figure 3 is a view taken in the direction of the arrow III in
Figure 2.
The one-piece plastic strap shown in the drawings comprises an
elongated flexible portion 4 having teeth 6 formed along a surface of
a central portion thereof. The flexible portion 4 has a free end
portion 8 provided with roughened surfaces so that the portion 8 can
be readily gripped and pulled for the purpose of tightening the strap.
The flexible portion 4 extends from a fixing portion 10 of the strap
which enables the strap to be secured to a headed stud (not shown)
projecting from a support. The fixing portion 10 defines a keyhole-
shaped slot 12 into which the stud is introduced. To fix the strap,
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the strap is moved so that the stud enters the narrow end of the slot
12 and is retained therein by a stud-locking portion 14 of the fixing
portion 10. It should be noted that the fixing portion 10 is optional
and need not be ;ncluded if it will not be desired to fix the strap to
a stud.
The strap also comprises a locking device 16 joined to the fixing
portion 10 by a flexible portion 18. The locking device defines a
slot 20 into which the free end portion 8 of the flexible portion 4
can be introduced and locked in the slot 20 so that the strap forms a
retaining loop as shown in Figure 1. The strap is wrapped around a
workpiece or workpieces to be retained in forming the loop.
The slot 20 of the locking dev;ce 16 is defined by a base portion
22 of the locking device 16, two parallel leg portions 24 extending
from the base portion 22, and a pawl portion 26 integral with and
supported by the leg portions 24 for pivoting movement therebetween.
The pivoting movement is accommodated by flexing of the interconnections
28 between the pawl portion 26 and the leg portions 24.
The pawl portion 26 comprises a locking portion 30 in the form of
a tooth which is arranged to interengage with the teeth 6 of the flexible
portion 4 within the slot 20 thereby locking the flexible portion 4
against movement relative to the slot 20. The teeth 6 and 30 are so
arranged that, if the flexible portion 4 is moved so as to tighten the
loop formed by the strap, the pawl portion 26 pivots releasing the
interengagement of the teeth 6 and 30 and allowing the movement but,
if the movement is in the strap undoing direction, the teeth 6 and 30
lock together preventing the movement. The pawl portion 26 also
comprises an engagement portion 32 engageable to cause the pawl portion
26 to pivot between the leg portions 24 so that the interengagement of
the teeth 6 and 30 is released.
The locking device 16 also comprises a bracing portion provided
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by two lugs 34 which form contlnuations of the leg portions 24 one on
each side of the engageMent portion 32 of the pawl portion 26. The
bracing portion is in opposed relationship to the engagement portion 32
and is rigidly connected to the leg portions 24. This arrangement
provides that, when the engagement portion 32 and the bracing portion
are pressed together (for example between the finger and the thumb),
the pawl portion 26 pivots releasing the interengagement of the teeth
6 and 30. The engagement portion 32 moves to a position between the
lugs 34 to pivot the pawl portion 26. Because pressure is applied to
a rigid portion of the locking device 16 as well as to the pawl portion
26, there is no possibility that the pressure applied to the pawl portion
26 will move the entire locking device 16 ratKer than causing the pawl
portion to pivot.
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