U.S. patent number 3,901,577 [Application Number 05/436,422] was granted by the patent office on 1975-08-26 for grounding clamps and connectors therefor.
This patent grant is currently assigned to General Signal Corporation. Invention is credited to Frank L. Browne, Robert A. Philibert.
United States Patent |
3,901,577 |
Philibert , et al. |
August 26, 1975 |
Grounding clamps and connectors therefor
Abstract
A versatile family of clamps, and associated or accessory
connectors, are disclosed; such fittings being adapted to connect
ground wires and other equipment to a source of ground potential.
Also disclosed is a technique for fabricating parts of the clamping
devices by means other than the commonly known casting techniques;
that is, techniques according to which the parts are cast by
utilization of sand cores. Instead, by judicious selection of
external and internal parting lines for the mold used in the
casting process, the present invention permits the elimination of
such sand cores, which are expensive and require extremely precise
formation.
Inventors: |
Philibert; Robert A.
(Burlington, CT), Browne; Frank L. (Bristol, CT) |
Assignee: |
General Signal Corporation
(Rochester, NY)
|
Family
ID: |
23732334 |
Appl.
No.: |
05/436,422 |
Filed: |
January 25, 1974 |
Current U.S.
Class: |
439/804;
439/811 |
Current CPC
Class: |
H01R
4/643 (20130101) |
Current International
Class: |
H01R
4/64 (20060101); H01R 007/26 () |
Field of
Search: |
;339/265R,265F,276R,263L,95 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lake; Roy
Assistant Examiner: Desmond; E. F.
Attorney, Agent or Firm: Kleinman; Milton E. Wynn; Harold S.
Ohlandt; John F.
Claims
What is claimed is:
1. A clamping device for clamping to ground potential and for
connecting equipment to such potential, comprising:
a pair of clamping members for fitting around a water pipe or the
like;
means for clamping said members to the pipe or the like
independently of the connection to said clamping device of the
equipment to be grounded;
means for connecting said equipment to be grounded, including one
of said clamping members, which is shaped to receive means for
firmly securing said equipment to said clamping device; and further
including a threaded bolt or eye stud having an opening therein,
said one clamping member including a web and a pair of spaced
parallel flanges depending from said web, said web and said flanges
together defining a raised arched portion at the crest of which an
aperture extends perpendicular to and through said web so that said
threaded bolt or eye stud can be disposed in said aperture and a
grounding wire can be put through said opening in said bolt or eye
stud and secured against said raised arched portion.
2. A device as defined in claim 1, in which the other of said
clamping members is provided with screw-receiving holes.
3. A device as defined in claim 1, in which the other clamping
member is a U-shaped bolt, said one clamping member having
apertures provided at either end thereof for receiving the ends or
shanks of said bolt.
4. A clamping device as defined in claim 1, in which a slot is
provided in each of said spaced flanges so that said grounding wire
can be received therein.
5. A clamping device as defined in claim 4, including a
spaced-segment boss surrounding said aperture at the upper surface
of said web, said spaced-segment boss being adapted to receive a
variety of connector devices.
6. A clamping device as defined in claim 5, in which said connector
devices include a ribbed member extending longitudinally at
opposite sides of an opening provided therein, said ribbed member
being adapted to fit into spaces between segments of said boss.
7. A clamping device for clamping to ground potential and for
connecting equipment to such potential, comprising:
a pair of clamping members for fitting around a water pipe or the
like;
means for clamping said members to the pipe or the like
independently of the connection to said clamping device of the
equipment to be grounded;
said equipment to be connected including a grounding wire and an
armor shield;
a connector device, comprising a lower member having individual
recesses spaced along its longitudinal axis in spaced relation to
the armor and the grounding wire respectively; a cap or cover,
having its longitudinal axis in a single plane and extending
parallel to and in the same vertical plane as the longitudinal axis
of said lower member, said cap or cover member fitting over said
recesses in the lower member and including individual corresponding
projections for bearing down within said recesses on the armor and
grounding wire respectively; and a pair of screw-receiving openings
in said lower member, said openings being located at the sides
thereof and intermediately of said recesses along the longitudinal
axis of said lower member; a first pair of notches flanking the
recess for said armor, and a second pair of notches flanking the
recess for said grounding wire, the first pair of notches having a
greater depth than the second pair whereby said armor and grounding
wire are securely held within said connector device.
8. A clamping device as defined in claim 7, in which said lower
member of said connector device is constituted by said one clamping
member.
Description
BACKGROUND, OBJECTS AND SUMMARY OF THE INVENTION
This invention pertains to electrical fittings and more
particularly to clamping devices and connecting means associated
therewith for making firm electrical contact, by means of grounding
wires and the like, to a source of ground potential.
A number of techniques have been developed in the prior art for
clamping different kinds of electrical equipment or devices of one
type or another to a source of ground potential. One example of
such a technique, and of the equipment used therewith, can be
appreciated by reference to a 1970 catalog of the Gedney Electrical
Company, Terryville, Conn., particularly at page 63 thereof.
However, a number of drawbacks and deficiencies have existed with
prior art techniques and constructions and it is a primary object
of the present invention to overcome these deficiencies. For one
thing, many of the parts involved for the purpose of clamping to a
cold water pipe or the like for grounding purposes are expensive to
produce. This is for the reason that quite a bit of machining is
necessary with such parts.
Accordingly, it is a major object of the present invention to
reduce the machining necessary to a minimum and to enable the
casting of parts for the clamping devices and associated
connectors, including forming the holes required for the purpose of
securing parts together.
It is also a particular deficiency of the prior art that clamping
devices used for the purpose of clamping the ground wire, or both
the ground wire and the armor which sometimes surrounds the ground
wire, to the ground potential have involved the use of too many
screws in fastening or tightening down on the armor and the
ground.
Accordingly, it is another object of the present invention to
provide for clamping of both the armor and the ground wire by the
use of only two screws and to do so in a single simple operation.
Such technique contrasts sharply with prior art constructions in
which two separate clamping operations are involved.
As also indicated previously, the clamping device for clamping both
the armor and the grounding wire includes a clamping member which
is a cast part. Consequently it is only necessary, following the
casting process, to take the cast part and to drill and tap therein
only two holes to receive the screws required for clamping down on
both the armor and the grounding wire. This arrangement constitutes
a principal feature of the present invention.
Also included as part of the clamp for clamping down on both the
armor wire and the ground wire is a cap or cover piece which is
provided with projections that fit into the recesses formed in the
cast member. This cap or cover piece is able to rock or shift in
accordance with the different sizes of wire, whether solid or
stranded, for both the grounding wire and the armor wire, that is,
in accommodating each to its particular recess formed in the cast
part.
Another aspect or feature of the present invention resides in the
provision for accommodating a variety of accessory connectors in
conjunction with the clamping device so that a variety of different
equipment or devices can be connected to the source of ground
potential. In other words, the present invention affords great
versatility and flexibility in providing that a standardized part
or member of the clamping device can accept different accessories
at different locations for connecting different kinds of equipment
to ground potential.
In broadly stated terms, then, the present invention may be
characterized as a clamping device for clamping to ground potential
and connecting a variety of devices thereto comprising: a pair of
clamping members, at least one of which is a cast member, for
fitting around a water pipe or the like; means for clamping said
pair of members to the pipe or the like independently of the
connection to said clamping device of the equipment to be grounded;
and means for connecting said equipment to be grounded, including
said cast member which is shaped to receive means for firmly
securing said equipment to said clamping device.
The above characterization of the invention brings out another
essential feature, namely, that there is complete independence
between the physical clamping action to the water pipe or the like
and the connection of a grounding wire, and associated equipment,
or the connection of both a grounding wire and armor wire, to the
accessory connector so that the ground potential will be properly
connected.
The above and other objects, features and advantages of the present
invention will be understood by reference to the following detailed
specification, taken in conjunction with the accompanying
drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a first preferred embodiment of a
clamping device in accordance with the present invention.
FIG. 2A is a perspective view of one of the accessory connectors or
connecting lugs to be associated with the clamping device of FIG.
1.
FIG. 2B is a fragmentary bottom plan view of the connecting lug of
FIG. 2A.
FIG. 2C is a perspective view of another connecting lug for
accommodating rigid conduit and bare ground wire.
FIG. 2D is another form of connector lug suitable for
through-ground wires.
FIG. 2E is yet another form of connector lug for accommodating bare
ground wires and armor.
FIG. 3 is another preferred embodiment of a clamping device in
accordance with the present invention, such device being composed
of two cast members.
FIG. 4 is yet another embodiment of a clamping device, similar in
style to the device of FIG. 3, but having included therein recesses
in the upper cast member for receiving ground wire and surrounding
armor.
FIGS. 5 and 6 illustrate the technique of casting a typical
accessory connector.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawing, and in particular for the moment to
FIG. 1 thereof, there will be seen a first preferred form or
embodiment for the clamping device of the present invention. The
device per se is generally designated 10, being constituted of a
pair of clamping members 10A and 10B. In this particular embodiment
the member 10A is a cast member, being composed of malleable iron,
hot dip galvanized or including copper alloy. The other part of
member 10B is formed as a U-bolt and is generally composed of
steel, hot dip galvanized or copper alloy. The U-bolt 10B, as will
be seen, fits around a cold water pipe 12 shown in phantom outline.
The two members 10A and 10B are secured together by means of a pair
of nuts 14, which are also typically composed of steel or copper
alloy. Firm and fixed mechanical contact with the pipe 12 is
assured by the serrated edges at the bottom surface of the member
10A which serrated edges are disposed near the periphery of the
member, at both the front and the rear wall or flange portions 16
thereof. The serrated edges also assure good grounding contact by
penetrating the surface skin of the pipe.
A pair of slots 18 are provided at the center of the front and rear
walls of the member 10A so as to permit ready connection of a
grounding wire, not shown, which is arranged to fit through the eye
stud 20; that is, through the opening therein 22 for this purpose.
The eye stud 20 fits through an opening or aperture 24 which
extends to the upper part of the member 10A, the upper surface
thereof being provided with a spaced-segment boss 26 which
surrounds the opening 24. A nut 28 is provided for threaded
engagement with the eye stud 20, thereby to retain and secure the
grounding wire firmly against the underside of the clamp member 10A
within the notches 18.
It will be appreciated that the eye stud 20 is not only used
selectively for securing such grounding wire but serves as a bolt
in those cases where a variety of accessory connectors, to be
described, are disposed at the boss 26 for connection to the clamp
member 10A. Such accessory connectors are illustrated in FIGS.
2A-2E.
What will be especially appreciated from the foregoing is the
unique feature of the present invention by which the clamping
members can be attached to the cold water pipe or the like
independently of the connection of equipment, such as grounding
wires or the like to the clamping device 10. Thus, the eye stud 20
will be inserted in the aperture 24, and before connection of the
grounding wire, by means of accessory connectors, is actually
accomplished, the nuts 14 at the end of the U-bolt 10B will have
been tightened down at the edge of the cast member 10A.
Another spaced-segment boss 30 is provided at one end of the cast
member 10A, being of similar construction to the previously
described boss 26 and affording an alternate point or position for
attachment of the accessory connectors. This boss surrounds one of
the openings 32 formed at the ends of member 10A through which the
end of the U-bolt 10B pass.
Accordingly, it will be apparent that the advantage of versatility
is present in the clamping device of the present invention because
a variety of these accessory connectors, which are adapted to
accommodate different equipment, can be attached or connected to
the basic clamping device at several points or locations thereon.
For convenience, the central position at which boss 26 is formed is
referred to as position A and the peripheral position as position
B. Further versatility lies in the fact that the clamping device is
complete with respect to its function in clamping to a cold water
pipe or the like, and yet, with the given device, a variety of
sizes of accessory connectors can be readily utilized. In other
words, the clamping device does not have to be disassembled or
rearranged to permit connection thereto of a variety of different
sizes and types of equipment.
Referring now to FIGS. 2A-2E a number of examples of different
types of accessory connectors is therein illustrated. In FIG. 2A
there is shown a connector 40 especially adapted for accommodating
bare ground wires and the like in a "dead-end" connection. Thus a
bare ground wire is inserted into the connector through the opening
42 and the screw 44 is tightened down on the end of the ground wire
46, shown in phantom outline. FIG. 2B shows the underside of the
connector 40 and particularly illustrates the provision of a rib 48
extending longitudinally at the periphery of the opening 49. It
will be understood of course that the opening 49 is lined up with
the opening 24 to permit passage of the eye stud 20 therethrough
when the connector 40 is to be attached at position A to the clamp
10 (see FIG. 1). The rib 48 fits snugly within the spaces between
the segments of the boss 26 and insures a firm engagement
therewith. Alternately, the opening 49 of the connector can be
lined up with the opening 32 at the center of boss 30.
There is shown in FIG. 2C another form of accessory connector 50.
In this instance, provision is made for accepting rigid conduit as
well as the ground wire that is to be connected to the cold water
pipe. The rigid conduit 52, showin in phantom outline, is received
within the threaded opening 54 and the ground wire 55 is secured by
means of the screw 56 which is tightened down thereon. The
underside of the connector 50 is, like the connector 40 in FIG. 2A,
provided with a longitudinal rib for purposes already
explained.
FIGS. 2D and 2E show other forms of connectors 60 and 70,
respectively, both of which are adapted to be secured to the clamp
10 in the manner already indicated, that is, at either position A
or position B thereof. The connector 60 of FIG. 2D is adapted to
provide for securing of a bare ground wire which extends to other
pieces of equipment, that is, the groundwire is not dead-ended, as
the case with the connector of FIG. 2A, but rather common
connection of ground potential to multiple pieces of equipment is
accomplished by means of the single, extended ground wire. For this
reason, the lower member 60A is provided with an open ended channel
or groove 62 and the upper member 60B with a corresponding channel
or groove 64. Both channels or grooves are ribbed to provide firm
securing to the ground wire. The upper member or cap 60B is secured
by means of the screw 66 which is received in the apertures 68 and
69 in the respective connector members 60B and 60A.
The connector 70 embodies that feature of the present invention
which fullfills the objective of a connector for clamping in a
simplified manner both armor and grounding wire to the ground
potential. The connector 70 comprises a lower member 70A and an
upper member or cover 70B, both of these members being cast
members, that is, they are formed by a casting technique to be
described hereinafter. The result of this casting technique is that
only two holes or apertures 72 need to be drilled and tapped for
the reception of screws in securing either a bare ground wire or
the combination of armor and ground wire. It should be noted that
the connector 70 can accommodate three different sizes of wires,
whether they be solid or stranded.
In its specific construction the connector 70 includes two separate
compartments or recesses 74 and 75. The recess 75, which is closer
to the opening 76, is not as wide as recess 74. Each of the
recesses 74 and 75 is flanked by a pair of V-shaped notches 77 and
77' respectively in which the respective wire or armor will be
firmly engaged. The notch 77 extends to a greater depth than the
notch 77' and is also broader, thereby to accommodate the larger
equipment, i.e., the armor.
The cover 70B is provided with corresponding teeth-like projections
78 and 79 which also have V-shaped notches therein, such notches
fitting over and thereby engaging the respective armor or ground
wire accommodated by each of the respective recesses 74 and 75.
U-shaped notches 80 are provided at the sides of the cover 70B so
as to permit appropriate screws, not shown, to be accommodated and
thereby to hold down the cover 70B when the screws are inserted in
the openings 72 and are tightened down. As noted previously, the
cover 70B is capable of rocking to some extent so as to permit
securing of varying sizes of armor and ground wire.
Turning now to FIG. 3 of the drawing, there is shown therein
another preferred embodiment of the clamping device in accordance
with the present invention. In this embodiment, the clamping device
90 consists of two principal parts, an upper cast member 90A and a
lower cast member 90B. The upper member shares with the embodiment
of FIG. 1 the general feature of a centrally located boss 92 which
is similar to the boss 26 in FIG. 1. The boss 92 comprises a
plurality of segments which surround a centrally located aperture
94 adapted to receive an eye stud 96 (substantially the same as the
eye stud 20 previously discussed in connection with FIG. 1).
Accordingly, the embodiment of FIG. 3 possesses the same basic
advantage, namely that of being able to tighten the clamping device
on the cold water pipe or the like for grounding purposes,
independently of the operation of actually securing an accessory
connector or the like to the boss 92.
It should also be noted that, rather than the lower member taking
the form of a U-bolt as in FIG. 1, the lower member 90B can also be
cast member suitably provided with a ribbed structure for
slip-proof engagement with the cold water pipe. The lower member
90B is provided with a pair of holes 98 which in securing the clamp
are lined up with the open-ended grooves or channels 100 in the
upper member 90A.
As before, the eye stud 96 is placed in position so that its
threaded shank extends through the aperture 94 and then, any one of
the previously described accessory connectors, that is, any of the
lug connectors depicted in FIGS. 2A-2E, can be selectively
positioned at the boss 92 -- following securement of the clamping
device -- and the eye stud shank will extend through the suitable
openings in the accessory connectors. Following this, the nut 102
is tightened down on the eye stud 96. Alternately, a suitable
grounding wire may be attached to the clamp 90 by being fitted
through the opening in the eye stud 96 and thence secured firmly
against the underside of the upper clamp member 90A when the nut
102 is tightened properly.
Referring now to FIG. 4, yet another embodiment is depicted in
which a clamping device 110 is seen. Since this device utilizes the
same lower part as the embodiment of FIG. 3, the same numeral 90B
refers to this lower part. However, the upper part is designed
specifically for the purpose of receiving either a bare ground wire
or the combination of armor and ground wire, as was advantageously
seen in the accessory connector of FIG. 2E. Thus, although the
numeral 112 designates the upper part or member, the same numerals
as in FIG. 2E refer to like parts, for example, to the several
recesses provided, as well as the other internal structure for
receiving the equipment in the form of the armor or the ground
wire.
Referring now to FIGS. 5 and 6 the technique of the present
invention for casting the accessory connectors and like parts will
be understood. This technique permits the casting of the connectors
without the utilization of sand cores, which is the conventional
method. Instead, the required configuration or structure for the
connectors is achieved in a vertical casting process, simply as a
result of judicious selection of external and internal parting
lines for the mold. Such technique permits very economical and
extremely fast casting of the required parts, that is, of the
accessory connectors, because of the elimination of sand cores.
There will be seen in FIGS. 5 and 6 several views of the sand mold
involved in the instant technique, including the connector 40
fabricated therein. The connector 40 is the same as the connector
previously illustrated in FIG. 2A, which is a connector intended
for use with "dead-end" bared ground wires. As already explained
previously, the opening 42 is provided for the ground wire, while
the opening 49 accommodates the eye stud 20 used in connecting the
connector 40 to the clamping device 10.
It will, of course, be understood that the connector 40 is merely
exemplary of the variety of connectors that can be fabricated in
the manner to be described. Connectors of this type are generally
fabricated of malleable iron with a hot dip galvanized finish.
The accessory connector 40 illustrated in FIGS. 5 and 6 is cast in
the sand mold 200, which is made from bonded sand in such a way
that liquid metal poured into it will, after solidification, retain
the mold shape and can be separated from it.
It will be understood that the mold 200 consists of two portions,
the upper portion being called the cope 200A and the lower portion
being called the drag 200B.
In the technique of the present invention, the correct mold form is
obtained by using what is called a match plate pattern. Thus, rapid
production is facilitated by mounting the drag half of a pattern on
one side of a wood or metal plate and the cope half directly
opposite on the reverse side. This plate is attached to the drag
flask and used like a follow board when ramming the drag; the cope
sand is rammed against the reverse side. Finally the match plate
pattern is removed, leaving a cope and drag that match perfectly at
the parting line. The gates are generally made by the pattern at
the same time.
It will be seen in FIGS. 5 and 6 that the cope and drag meet and
match at the parting line; the external parting line is shown by
means of broken line 210, while the internal or interior parting
line is shown in the same way by means of the broken line 212.
These parting lines are irregular but are carefully arranged so
that a requisite structural feature of the accessory connector 40
can be realized. This feature enables the connector to meet the
stringent pull-out requirements imposed by Underwriters'
Laboratories, namely, that the ground wire which is to be retained
or held by the connector 40 cannot be pulled out by a force less
than the specifications call for. To this end an interior or
internal rib 220, is formed, which extends around the inner surface
of the central opening 42 defined in the finished connector 40.
This rib 220 is formed one-half within the cope and one-half within
the drag of the sand mold.
While there has been shown and described what is considered at
present to be the preferred embodiment of the present invention, it
will be appreciated by those skilled in the art that modifications
of such embodiment may be made. It is therefore desired that the
invention not be limited to this embodiment, and it is intended to
cover in the appended claims all such modifications as fall within
the true spirit and scope of the invention.
* * * * *