Note: Descriptions are shown in the official language in which they were submitted.
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Back~round of the Invention
This invention relates to industrial-type electrical cable connectors
and, in particular, to those connectors having three basic elements: (1)
a rigid insulating part which carries the electrical terminals; (2) a flex- -
ible fluidtight casing which encircles the cable and isolates the electrical
terminals from foreign matters; and (3) a clamping part to secure the cable
and which is in turn secured to the part carrying the terminals.
A problem with connectors of the above type centers around the flexible
casing. A flexible casing is fairly elastic, which elasticity provides a
lo high quality seal. This deformation especially occurs upon assembly. When -
the rigid terminal carrying part is positioned in the chamber defined by the
elastic casing and secured with screws to the clamping part, the end wall of
the casing, which is intermediate the terminal insert part and clamping part,
is subjected to axial compressive forces which cause radial expansion of the
external cylindrical surface of the casing. This bulging, or radial expan- ;
sion, is undesirable, as it prohibits the placing of two connectors side by
side in the standard dual receptacle, due to interference. A previous attempt
to solve this problem included the use of fasteners to secure the clamp part
and terminal part together and which slip at a point prior to the bulging of
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the rubber casing. This requires a special fastener construction and is costly.
Summary of the Invention
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The present invention solves the previously described problem without
sacrificing any effectiveness of the fastening means and, at the same time,
incorporates industrial simplicity and practicality. The undesirable com-
pression of the rubber casing is prevented by the extension of molded sleeves
from the clamp part through holes in the rubber casing end wall. In a pre-
~' ferred embodiment of the invention, these sleeves are integrally molded with
.~ the clamp part. The screws which secure the terminal insert to the connec-
tors are threaded into the sleeves, fastening the three component parts se-
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3~ curely together at a set distance apart. No bulging of the casing occurs
because the innermost surface of the terminal insert contacts the sleeves
which act as a stop to prevent engagement of the terminal insert part with the
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rubber casing, and thus prevent any compression of the rubber casing.
An alternative method of accomplishing the same object is to attach
the sleeves to the terminal insert part, preferably by integrally molding them
with the insert. The screws, which enter the connector from the external
surface of the terminal insert, then pass freely through the sleeves and are
threaded into the clamping part. In both cases, the sleeves rigidly posi-
tion the terminal insert a set distance from the clamping part and prohibit
any compression of the casing end wall.
The innovative plastic sleeves, extending from either the clamping
part of the terminal insert part, are narrow rigid cylinders which retain
the screws (preferably self-tapping) and tunnel through the openings in the
casing. Preferably, the sleeves are formed integrally with the clamping part
and together they comprise a one-piece molded part.
The resilient elastic casing consists of two basic portions namely:
~` ~1) a generally tubular portion defining a chamber in which the electrical
elements are located, and ~2) an end wall closing one end of the tubular
chamber and providing expansible fluidtight seal encircling a cable entrance
into the chamber. Due to its resilient elastic nature, cables of different
diameters can be received through the end wall.
A clamp arrangement is provided to secure the cable prior to its
entry into the chamber. The clamping arrangement includes the previously-
mentioned clamping bracket, two gripping elements, and two fasteners. The
clamping bracket is an annulus of molded plastic having on one axial side a
pair of diametrically positioned protrusions and on the opposite axial side
are the previously noted sleeves. The gripping elements are fastened to
each side of the protrusions to secure the cable.
According to the present invention then there is provided an
electrical connector having a body defining a chamber and including an end
~` wall closing one end of the body. Electrical elements are carried by
an insulating part which is located in the chamber. The body has an
integral molded construction of resilient
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material and includes a generally tubular portion. An opening is provided
in one end wall for an electrical cable to extend therethrough into the
chamber for connection with the electrical elements. The end wall is pro- ~`
vided with a portion which defines an opening effecting a fluid tight
sealing engagement with the cable. A plurality of longitudinally extending
sleeve openings are provided in the end wall. Clamp means are provided
for clamping the electrical cable prior to its entry into the chamber, and
including a clamp part. Threaded fasteners are provided which extend into
threaded engagement with the clamp part and secure the clamp part to the
insulating part. The electrical connector has a plurality of sleeves ex-
tending from one of the parts for engaging the other of the parts and
blocking compressive engagement of the other of the parts with the body
so that compressive action does not occur to the body which would cause
bulging thereof. The sleeves are of uniform cross-sectional dimension
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throughout their extent and are removably slidably received in sleeve
receiving openings in the end wall.
Description of the Figures
Further features of the present invention will be apparent to
those skilled in the art to which it relates from the following detailed
description of a preferred embodiment made with reference to the accompany-
ing drawings in which:
Figure 1 is an exploded view of an electrical connector embodying
the invention; and
Figure 2 is a cross-sectional view of the assembled connector.
Detailed Description of the Preferred Embodiment
The present invention provides an electrical connector of improved
construction and, particularly, provides an electrical connector having
- means for preventing an axial clamping of a tubular flexible casing between
the terminal insert and a cable clamping part. The means which prevents the
axial clamping comprises plastic sleeves integrally molded to either the
clamping bracket or terminal insert part, and which block any compressive
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action on said tubular flexible body which would result in bulging thereof.
Illustrated in Figure 1 are the separated component parts which
comprise the connector of the present invention. As illustrated, the con-
nector comprises a support body or molded casing 10 which comprises a
generally tubular portion 11 and an end wall 12. The external surface of
the tubular portion 11 is generally cylindrical, but does include an en-
circling indentation llA which roughly corresponds to the area where the end
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wall 12, a relatively narrow di~c, is integrally molded to the
tubular portion 11.
The tubular portion 11 defines a chamber 13 in which a ~ -
terminal insert 14 i~ received. The chamber 13 is terminated by
the end wall 12, which has a thin, highly elastic portion 27
at its center defining an opening 15 therethrough. An electrical
cable 16 extends through the opening 15 and into the chamber 13
; for connection with the electrical elements of the terminal
part 14, as is well known. Due to the flexibility and resiliency
of the portion 27 of the end wall 12, a fluidtight seal en-
compasses the cable 16.
The insert 14 has a portion 14A which is received in a
groove 14B formed in the inner wall 13A defining chamber 13.
The groove 14B provides for proper positioning of the terminal
insert 14 in the chamber 13 during assembly so holes 18 in the
terminal insert 14 are aligned with holes 21 in the end wall 12.
; Due to the seal around the insert 14 provided by chamber 13
`~ and the seal around cable 16 provided by portion 27 of the end
. wall 12, the electrical elements of the insert 14 are substan- -
tially isolated from foreign matter that may be in the vicinity
of the connector. As a result, the connector 10 is particularly
adaptable for ind~strial use, since foreign matter, such as oil,
which may be in the vicinity, is effectively isolated from the
`~ electrical elements of insert 14.
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The present ~n~ention includes the use of sleeves 19
which penetrate the end wall 12 through holes 21 when screws 17
secure the terminal insert 14 to the clamping bracket 20.
``~ Sleeves 19 may be integrally molded to either the clamping
bracket (as shown in Fig. 1) or to the terminal insert. In
either case, the sleeves extend through the end wall 12.
` Due to the seal around the insert 14 provided by chamber 13
and the seal around cable 16 provided by portion 27 of the end
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wall 12, the electrical elements of the insert 14 are substan-
tially isolated from foreign matter that may~be in the vicinity
of the connector. As a result, the connector 10 is particularly
adaptable for industrial use, since foreign matter, such as
oil, which ma~ be in the vicinity, is effectively isolated from
the electrical elements of insert 14.
The present invention includes the use of sleeves 19 which
penetrate the end wall 12 through holes 21 when screws 17 secure
the terminal insert 14 to the clamping bracket 20. Sleeves 19
may be integrally molded to either the clamping bracket (as
shown in Fig. 1) or to the terminal insert. In éither case, the
sleeves extend through the end wall 12.
~As best shown in Figure 2, the sleeves 19 have a length
-- such that the terminal insert part 14 engages the outer end sur-
face l9A of the sleeves without forcefully engaging the adjacent
-~urace of the tubular casing 10. As a result, compressive
forces are not applied to the casing and lateral bulging of the
material of the casing does not occur. Accordingly, two con-
nectors of the present invention can be used in a dual electrical
receptacle without interferences.
The clamping bracket 20, shown in Figure 1, consists of an
annular body 28 with thè sleeves 19 extending to the left and
rectangular protrusions 22 extending to the right providing
means for mounting semicircular clamping elements 25. Screws 24,
preferably self-tapping, secure the clamping elements 25 around
the cable 16 so as to prohibit movement of the cable after as-
sembly. The semicircular indentation 26 in the clamping bracket
ao is designed to engage the protrusion 26A in the body 10,
`thereby providing for proper positioning of the clamping bracket
10 into the body 10 during assembly.
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