Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a grounding strap
and, more particularly, to a pliable metal grounding
strap of the type to be bent around a ground member, such
as a grounded pipe or metal post, and thereafter secured
thereto.
One type of pliable metal grounding strap which has
been proposed before comprises an elongated strap member
having a plurality of longitudinally spaced apart holes at
one end portion and a nut welded thereon at the other end
portion. A flap is detachably mounted to the strap member
by means of a tab and slot arrangement adjacent the nut
and is adapted to be positioned intermediate the ground
member and a bolt extending through the nut for securing
the strap member to the ground member, prior to bending
the strap member around the ground member and over the
nut with one strap hole registering with the nut hole and
installing the bolt. This two-piece construction is rather
disadvantageous since it is difficult and time consuming
to install. Further, the flap serving to provide grounding
contact between the bolt and the ground member and also to
protect the latter from being damaged by the bolt can be
easily lost. In addition, since the nut is welded to the
strap member, the weld can readily break as a result of
repeated use and bending of the strap member.
In order to overcome these disadvantages, Applicant
has already proposed a pliable metal grounding strap of the
type described above, but in which the welded nut is re-
placed by a threaded collar riveted to the strap member
and the detachable flap is replaced by an inwardly curved
strap section integrally joined to one end of the strap
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member so as to provide a one-piece construction. ~owever,
as the curved strap section must first be placed on the
ground member and the strap member thereafter bent over
such curved section and around the ground member, the bolt
or screw is often mispositioned relative to the underlying
curved strap section and contacts same at an oblique angle,
resulting in a poor grounding contact.
Accordingly, it is an object of this invention
to overcome the aforementioned drawback and to provide a one-
piece pliable metal grounding strap which avoids misp~sitioningof the screw and therefore ensures a good grounding.
In accordance with the present invention, there is
thus provided a one-piece pliable metal grounding strap comprising
a U-Shaped section having a pair of leg portions interconnected
by a bight portion. One of the leg portions has an inwardly
bent section extending adjacent thereof and across the bight
portion, the bent section being adapted to contact on one
side thereof a ground member, a hook member outwardly projects
from this leg portion. A collar member is fixed to the bight
portion, the collar member having a threaded bore adapted to
threadably engage a screw member and being disposed to permit
the screw member to frictionally engage the bent section on the
other side thereof substantially perpendicularly thereto. The
other leg portion is extended relative to the aforesaid one
leg portion to define an elongated wrap section adapted to
be bent about the ground member and over the one leg portion
and the bight portion with the ground member disposed between
the bent section and the wrap section' the wrap section is
provided with a plurality of longitudinally spaced apart
apertures adapted to receive the hook member and to register
with the treaded bore for receiving the screw member. Tight-
ening of the screw member causes same to frictionally engage
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with the bent section against the ground member and to move
the bight portion in a direction away from the bent portion,
thereby causiny the hook member to pull the wrap section
in the same direction and to tighten same against the ground
member.
By disposing the collar member on the bight
portion of a preformed U-shaped strap section directly over-
lying the inwardly bent strap section, such that the screw
member frictionally engages the bent section substantially
perpendicularly thereto, there is no longer any possibility
of the screw member being mispositioned and thus proper
grounding is ensured whenever the grounding strap of the
invention is installed.
The invention is illustrated by way of example
in the accompanying drawings, in which:
Fig. 1 is a perspective view of a grounding
strap according to the invention as seen positioned on a
ground member for installation thereon,
Fig. 2 is a view similar to that of Fig. 1,
showing the grounding strap in a first stage of its
installation,
Fig. 3 is a part sectional view showing the
grounding strap in a second stage of its installation,
Fig. 4 is a part sectional side elevation view
showing the grounding strap in a third stage of its
installation, and
Fig. 5 is another part sectional side elevation
view showing the grounding strap as finally installed
on the ground member.
Referring first to Fig. 1, the grounding strap
illustrated and generally designated by reference numeral
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10 is seen positioned for installation a ground member
such as a grounded metal pipe 12 represented in broken
lines. The grounding strap 10 is a one-piece copper
pre~ormed construction comprising a U-shaped section having
a pair of curved leg portions 14 and 16 interconnected by
a planar bight portion 18. The leg portion 14 is provided
with an inwardly curved section 20 also of U-shape extend-
ing across the bight portion 18 and having one end integrally
joined to leg portion 14 and the other end extending adjacent
leg portion 16~ As shown, the curved section is adapted to
contact on its innerside the grounded pipe 12.
A hook 22 outwardly projects from leg portion
14. A collar 24 is riveted to the bight portion 18 on the
side thereof facing the curved section 20. The collar 24
has a threaded bore 26 adapted to threadably engage the
threaded shank of screw member such as a bolt 28 and is
disposed to permit the bolt 28 to frictionally engage the
curved section 20 on its outerside perpendicularly thereto,
as best shown in Figs. 3 and 5.
The leg portion 16 is extended relative to leg
portion 14 so as to define an elongated wrap section 30
adapted to bent about the ground member 12 and over the leg
portion 14 and the bight portion 18 with the ground member
12 disposed between the curved section 20 and the wrap
section 30. The wrap section 30 is provided with a plurali-
ity of longitudinally spaced apart holes 32 adapted to
receive the hook 22 and also to register with the threaded
bore 26 of collar 24 for receiving the bolt 28. A lock
nut 34 and washer 36 complete the assembly.
In order to install the grounding strap 10 on
the grounded pipe 12, the curved section 20 of the strap is
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first placed on the pipe 12, as shown in Fig. 1. Next,
the wrap section 30 is bent around the pipe 12 and over
the leg portion 14 while pressing it against the pipe in
order to ensure a snug fit, as shown in Fig. 2; the strap
hole 32 in closest alignment with the hook 22 is placed
over the hook so as to connect the wrap section 30 to the
leg portion 14. The bolt 28, lock nut 34 and washer3~ are
removed and the wrap section 30 is further bent over the
bight portion 18 so that another strap hole 32 registers
with the treaded bore 26 of collar 24, as best shown in
Fig. 3. The bolt, nut and washer assembly is reinstalled
and any extra length of the wrap section 30 is bent over the
leg portion 16. ~ereafter, as shown in Fig. 4, the bolt
28 is tightened so as to frictionally engage with the curved
section 20 against the pipe 12, as a result, the bight
portion 18 is moved in a direction away from the curved
section 20, which causes the hook 22 carried by the leg
portion 14 to pull the wrap section 30 in the same direction
and to thereby snugly tighten same against the pipe 12. The
final shape of the strap thus installed is represented in
Fig. 5 and it is seen that the curved section 20 and wrap
section 30 of the strap snugly conform to the pipe 12 and
thus provide good grounding, the shank of the bolt 28 extend-
ing perpendicularly to the curved section 20. A ground wire
38 is placed between the lock nut 34 and washer 36 and the
nut is finally tightly secured.
As an example of dimensions of a suitable grounding
strap 10, the overall length may be about 5 inches and the
width about 1/2 inch. Such a grounding strap accomodates
pipe diameters of 1/2 through 1 1/4 inch. As it is apparent,
it provides a versatile mechanical and electrical connection
for grounding to metal pipes or posts, in addition to being
fast and easy to install.
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