Note: Descriptions are shown in the official language in which they were submitted.
3L~t75338
This invention relates generally to an electrical terminal clamp
assembly for electrical conductors, and in particular to an improved construc-
tion for such terminal clamps.
Terminal clamp assemblies including a "roof-shaped" terminal clamp
having clamping or gripping projections and a non-round outer contour for
clamping electrical conductor leads to a fixed electrical contact element are
known in the art. See~ for example~ United States Patent ~umber 3,141,722.
In such clamp assemblies, the terminal clamp is secured in the electrical
equipment between confining walls by means of a screw which is releasably fas-
tened to the contac~ element so that it may be loosenedO The screw extendsthrough an opening in the terminal clamp which permits the clamp to be tilted
against the screw for equalizing different conductor diameters. The clamping
projections are disposed on the underside of the terminal clamp in the center
thereof and extend to the edges of the clamp which are disposed adjacent the
confining walls.
In the clamp assembly disclosed in the foregoing United States
Patent~ the terminal clamp has a rectangular outer contour and a gripping
projection extends on each side of the clamp to the straight, lateral edges
thereofO Terminal clamps of the foregoing type which include two gripping
projections disposed at each side of the clamp in spaced apart relationship
are also known in the art.
The foregoing type terminal clamp assemblies have the disadvantage
; that because the gripping projections extend to the straight, lateral edges
of the terminal caamp, the sharp corners and edges of the clamping projections
may be pressed into or scrape along the confining walls, which comprise elec-
trical insulating material, when the terminal clamp cants and twists during
tightening. As a result, the terminal clamp is supported at the confining
wall and not exclusively on the conductor lead or leads.
In order to eliminate this problem to some degree, the fit between
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the confining walls and the outer edges of the terminal clamp has been made as
loose as possible. This has been necessary particularly in view of the buck-
ling that occurs in the middle portion pf the screw when upsetting, i.e.,
tilting, the terminal clamp for captive attachment. Such a loose fit, however,
adversely affects the securing of the conductor leads and causes undesirable
twisting of the terminal clampO
It is therefore an object of the present invention to overcome the
foregoing disadvantages of heretofore known terminal clamp assemblies and to
provide an improved terminal clamp assembly construction which prevents the
clamping projections of the terminal clamp from engaging the confining walls
of the assembly during tilting of the clampO
These and other advantages of the invention are achieved in a ter-
minal clamp assembly including a clamp having an unround outer contour and
clamping projections for clamping electrical conductors to a contact element.
The clamp is secured between confining walls in the assembly by a screw which
is releasably engaged with the contact element and extends through an opening
in the terminal clamp. The clamp is tiltable against the screw for equali~ing
different electrical conductor diameters, and the clamping projections are
disposed in the center of the underside of the clamp and extend to the lateral
edges of the clamp disposed adjacent the confining walls. The improvement of
the invention comprises the clamp including center areas and outer areas dis-
posed along opposing lateral edges thereofO The center areas are disposed
between a pair of the outer areas along each of the lateral edges and are in-
wardly recessed towards the opening in the terminal clamp with respect to the
outer areas. The projection members extend to the lateral edges of the clamp
along the center areas, and, as a result, the clamping projections are preven-
ted from engaging the confining walls of the assembly during tilting of the
;~ terminal clamp.
The clamp preferably includes a pair of projection members disposed
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in parallel relationship on each side of the clamp opening which extend to
the lateral edges at the center areas of the clamp.
These and other novel features and advantages of the invention will
be described in greater detail in the following detailed description.
Figure 1 is a front p]an view of an improved terminal clamp assem-
bly constructed according to the present invention;
Figure 2 is a top plan view of the terminal clamp assembly illustra-
ted in Figure 1;
Figure 3 is a perspective side view of the terminal clamp assembly
illustrated in Figure 1; and
Figure 4 is a partial front plan view of another embodiment of a
terminal clamp assembly constructed according to the present invention.
Referring now to the drawings, and in particular to Figures 1
through 3, there is shown in an electrical equ:ipment apparatus including ele-
ments fabricated of electrical insulation material~ a terminal clamp 4 secured
between confining walls 1 in a fixed metallic electrical contact element 2 by
means of a threaded screw 3. Terminal clamp 4 has an arcuate shape and inclu-
des a central opening 5 through which screw 3 extends. Opening 5 is varied
in shape by upsetting, i e., tilting, the terminal clamp at the end face there-
of in such a manner that it is captively held at the screw but is tiltablebetween the screw head and the screw thread of screw 3 A pair of parallel
gripping or clamping projections 6 are embossed on each side of the undersur-
face of the terminal clamp in center areas 4a symmetrically with respect to
opening 5. Projections 6 project from the undersurface of clamp 4 and extend
to the lateral edges of each center area 4a of terminal clamp 4. Center areas
4a are each disposed between a pair of outer areas 4b disposed along each of
the lateral edges of the terminal clamp and are recessed with respect to the
outer area~ inwardly towards the center opening 5 of the clamp to prevent the
clamping projections from engaging the confining walls when the terminal clamp
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is in a tilted position, for example, when only one conductor lead or, alter-
nativelyg a pair of conductor leads of greatly different diameters, is clamped
between the terminal clamp and the contact elementO
Although the embodiment of the invention illustrated in the drawings
includes a pair of clamping projections in each center area, it should be noted
that either one or more clamping projections may be provided in these clamping
areas, as desiredO
As illustrated in Figure 4, the clamping projections may be shaped
so as to extend inwardly towards opening 5 in clamp 4 from the lower edge of
10 each of the lateral edges of the terminal clamp. The terminal clamp may~ as
shown in the drawings, have a non-round contour different from a rectangular~
shaped contour, if only the center area is set back from the outer areas of
the terminal clamp.
In the foregoing specification, the invention has been described
with reference to specific exemplary embodiments thereof. It will, however,
be evident that various modifications and changes may be made thereunto without
departing from the broader spirit and scope of the invention as set ~orth in
the appended claims. The specification and drawings are, accordingly, to be
regarded in an illustrative rather than in a restrictive sense.
