HERMETIC TERMINAL HAVING PIN-ISOLATING FEATURE
FIELD
[0001] The present disclosure relates to hermetic power terminal feedthroughs,
and more particularly to hermetic power terminal feed-throughs
employing dielectric over-surface protection for preventing electrical shorting of
the terminal.
BACKGROUND
[0002] This section provides background information related to the
present disclosure which is not necessarily prior art.
[0003] Conventional, hermetically-sealed, electric power terminal feedthroughs
(also referred to as "hermetic terminals") provide an airtight electrical
terminal for use in conjunction with hermetically sealed devices, such as A/C
compressors, where leakage into or from such devices, by way of the terminals,
is effectively precluded. For hermetically-sealed electric power terminal feedthroughs
to function safely and effectively for their intended purpose, the
hermetic terminals require that their conductor pins be electrically isolated from,
and hermetically sealed to, the body of the terminal through which they pass. In
addition, an optimum through-air path between adjacent portions of the pins the
opposite sides of the body, as well as between the pins themselves, must be
established and thereafter maintained to minimize the possibility for generating
an electrical short circuit at the terminal.
[0004] An exemplary hermetic terminal 1 and associated connector
block 2 having constructions that are well-known in the art are shown in FIGs. 1-
4 . In such conventional hermetic terminals 1, an electrically conductive pin is
fixed in place within an aperture through a metal body by a fusible sealing glass
that forms a hermetic, glass-to-metal seal between the pin and the terminal
body.
[0005] A resilient electrical insulator is bonded to the outside surface of
the body, as well as over the glass-to-metal seal and portions of the currentconducting
pins. The insulator provides a dielectric over-surface covering for
substantial portions of the outside surface of the terminal body and the conductor
pins. In doing so, the insulator increases a path through the air between
adjacent non-insulated portions of the conductor pins and the terminal body
(though not between the pins in their entirety) and reduces the ability for
contaminants, debris, and the like (e.g., metal shavings) to form unwanted
current paths that could create an electrical short circuit at the terminal between
the pin and the body.
[0006] Optionally, a connector block 2 like that shown in FIGs. 2, 3A
and 3B may be used in conjunction with the hermetic terminal 1. As illustrated in
FIGs. 3A and 3B, the connector block 2 cooperatively engages with the ends of
the plurality of conductor pins of the hermetic terminal 1 and provides a mounting
fixture for attaching to the hermetic terminal lead wires that can be electrically
connected to a power source disposed on one side of the hermetic terminal 1.
SUMMARY
[0007] This section provides a general summary of the disclosure, and
is not a comprehensive disclosure of its full scope or all of its features.
[0008] The disclosure provides a hermetic terminal having a body
member with a generally flat bottom wall and at least a first opening in the wall.
At least two electrically conductive pins, where at least one electricallyconductive
pin extends through each of the first openings, are hermetically
sealed within the first openings with a dielectric sealing material. Means for
increasing the operative through-air spacing between adjacent ones of the
electrically-conductive pins is also provided and enables a smaller diameter
hermetic terminal to meet UL power requirement specifications for hermetic
terminals for applications that would have previously required a larger diameter
hermetic terminal. Consequently, a smaller diameter hermetic terminal can be
used in higher voltage applications. Further, the pressure rating for a
compressor using a smaller diameter hermetic terminal can be increased
because of the smaller footprint of the terminal in the compressor which can
withstand higher pressures and enabling the use of higher pressure refrigerants.
[0009] In another aspect of the disclosure, a hermetic terminal has a
cup-shaped metallic body member including a generally flat bottom wall and a
peripheral side wall. The bottom wall has an exterior surface and a plurality of
first openings. A plurality of current-conducting pins extending through the first
openings. A dielectric sealing material extending between and hermetically
sealing the current-conducting pins is included within the first openings. A
dielectric pin-isolating feature attached to the body member increases the
operative through-air spacing between the current-conducting pins and includes a
lower base portion and an upper barrier portion. The base portion is sized and
shaped to closely fit the periphery of the exterior surface of the bottom wall. The
upper barrier portion has a plurality of generally vertically-upstanding, generally
planar ribs extending from the base portion, in a direction generally parallel to a
central axis of the hermetic terminal. The ribs terminate beyond the outer ends of
the current-conducting pins.
[0010] In still another aspect of the disclosure, a hermetic terminal has
a body including a wall having an exterior surface and a plurality of first
openings. A current-conducting pin extends through each first opening, and the
pins are sealed within the openings and electrically isolated from the body. A
dielectric barrier is attached to the body that is sized and shaped to closely fit the
periphery of the exterior surface of the wall. The barrier includes a plurality of ribs
that extend in a first direction generally parallel to a longitudinal axis of the pins
and terminate in the first direction beyond the outer ends of the pins. The barrier
increases the operative through-air spacing between the pins of the hermetic
terminal.
[001 1] Further areas of applicability will become apparent from the
description provided herein. The description and specific examples in this
summary are intended for purposes of illustration only and are not intended to
limit the scope of the present disclosure.
DRAWINGS
[0012] The drawings described herein are for illustrative purposes only
of selected embodiments and not all possible implementations, and are not
intended to limit the scope of the present disclosure.
[0013] FIG. 1 is a top perspective view of a prior art hermetic terminal;
[0014] FIG. 2 is a top perspective view of a prior art connector block
for use with the hermetic terminal of FIG. 1;
[0015] FIG. 3A is a side perspective view showing the hermetic
terminal of FIG. 1 joined to the connector block of FIG. 2 ;
[0016] FIG. 3B is a top perspective view showing the hermetic terminal
of FIG. 1 joined to the connector block of FIG. 2 ;
[0017] FIG. 4A is top plan view of a prior art hermetic terminal;
[0018] FIG. 4B is a cross-sectional side view of a prior art hermetic
terminal taken along the line A-A of FIG. 4A;
[0019] FIG. 5 is a front perspective view of a first embodiment of a
hermetic terminal of the present disclosure;
[0020] FIG. 6 is a front perspective view of a second embodiment of a
hermetic terminal of the present disclosure;
[0021] FIG. 7A a cross-sectional front perspective view of the hermetic
terminal of FIG. 5 ;
[0022] FIG. 7B is an enlarged detail view of a portion of FIG. 7A;
[0023] FIG. 8 is a top perspective view of a connector block of the
present disclosure for use with the hermetic terminals of FIGs. 5 and 6 ;
[0024] FIG. 9A is a top perspective view of a hermetic terminal of the
present disclosure joined to the connector block of FIG. 8 ; and
[0025] FIG. 9B is a top plan view of a hermetic terminal of the present
disclosure joined to the connector block of FIG. 8.
[0026] Corresponding reference numerals indicate corresponding parts
throughout the several views of the drawings.
DETAILED DESCRIPTION
[0027] Example embodiments will now be described more fully with
reference to the accompanying drawings.
[0028] Conventionally, multi-pin hermetic terminals, such as those
shown in FIGs. 4A and 4B, are used in a variety of air-conditioning and
refrigeration compressor applications and are designed to meet certain power
rating requirements. A significant factor affecting a hermetic terminal's power
rating, however, is the amount of through-air spacing between the adjacent
conductor pins of the hermetic terminal. In this regard, UL (a/k/a Underwriters
Laboratories) provides specifications for a hermetic terminal to be approved for a
specified voltage. Moreover, the exterior side of a hermetic terminal (i.e., the
side that is exposed to the outside environment) has a more stringent
requirement for electrical spacing under UL's specifications. And since the
manner in which an electrical connection is made on the exterior side of a
hermetic terminal is generally beyond the control of the hermetic terminal
manufacturers, the hermetic terminal manufacturers design their hermetic
terminals to meet the UL specifications independent of any additional electrical
barrier that may be employed by an end user to increase the electrical spacing of
the conductor pins after installation of the hermetic terminal, such as a connector
block for example.
[0029] In multi-pin hermetic terminals, the conductor pins are centered
and equally spaced about the terminal in a well-known manner. Referred to as a
pin circle, a circle that passes through the center of each of the conductor pins
has a diameter that is referred to as the pin circle diameter. Consequently, the
power rating of a hermetic terminal is related to its pin circle diameter since an
increase in the through-air pin-to-pin spacing of the hermetic terminal can be
achieved by an increase in its pin circle diameter. An increase in the pin circle
diameter, though, leads to a larger-sized hermetic terminal overall. Thus, a
hermetic terminal rated for a lower voltage threshold will traditionally have a
smaller overall diameter than a hermetic terminal rated for a higher voltage
threshold.
[0030] In order to provide some standardization for the hermetic
terminals used in air-conditioning and refrigeration compressor applications, two
threshold power ratings for hermetic terminals have become established: the 300
volt-rating and the 600 volt-rating. Consequently, industry manufacturers have
been able to standardize to two sizes (e.g., diameters) of hermetic terminals that
meet the two voltage ratings for air-conditioning and refrigeration compressor
applications. This means, for example, that there have to be two different sizes
for the cut-out holes in the compressor shell into which the hermetic terminals are
installed, and the machines that weld the hermetic terminals into the compressor
shell have to be configured to accommodate two different sized hermetic terminals.
[0031] The invention of the present disclosure, however, enables a
smaller diameter hermetic terminal to meet UL specifications while achieving a
voltage rating for applications that would have previously required a larger
diameter hermetic terminal. As a result, industry manufacturers can now
standardize their designs and tooling to a single-sized hermetic terminal.
[0032] Moreover, since a smaller diameter hermetic terminal can be
used, the pressure rating for the compressor can be increased. This is because
hermetic terminals having a smaller footprint in the compressor can withstand
higher pressures, allowing the compressor to have a higher pressure rating and
use higher pressure refrigerants. For example, because the hermetic terminal
can be manufactured to smaller overall dimensions than conventional terminals,
the surface area of the terminal that is exposed to the high pressure environment
of the compressor is decreased. Correspondingly, the force acting against the
terminal is also decreased (since the pressure remains constant). A decreased
force then enables the body of the hermetic terminal to be manufactured from a
material having a thickness that is less than that of conventional terminals.
Hence, the terminal body may be manufactured on smaller, less expensive tools
that can run at higher production speed, thereby increasing manufacturing
output.
[0033] Referring now to the drawings, and particularly to FIGs. 4A and
4B, a hermetic terminal 10 has a generally cup-shaped metal body member 12
with a generally flat bottom wall 14 and a peripheral side wall 16 having an
outwardly flaring rim 18. The bottom wall 14 of the body 12 has a dish-side
interior surface 20, an exterior surface 22, and a plurality of openings 24. The
openings 24 are each defined by an annular lip 26 with an inside wall surface 28,
a free edge 30 on the dish side of the body member 12, and a radius 32 on the
exterior surface side of the body member 12. The body member 12 may be
manufactured from a metal material such as steel.
[0034] A plurality of current-conducting pins 34 extend through
corresponding ones of the plurality of openings 24 in the body member 12. Each
conductor pin 34 includes an outer end 36 and an inner end 38, which may be
fitted with a conventional electrical connection strap 40 or an electrical quickconnect
tab 42, best seen in FIGs. 1 and 3A. As shown in FIG. 4A, in multi-pin
hermetic terminals the conductor pins 34 are centered and equally spaced about
the terminal 10. The conductor pins 34 lie on a pin circle 50 having a pin circle
diameter D. As such, the conductor pins 34 have a through-air spacing from pinto-
pin of S 1 and from pin-to-body of S2.
[0035] The conductor pins 34 may manufactured from an electrically
conductive metal material, such as solid copper or steel. Alternatively, a
bimetallic, copper-core wire, having high electrical conductivity and possessing
good hermetic bonding characteristics may also be utilized.
[0036] Each conductor pin 34 is sealed within its respective opening
24 of the body member 12 by a dielectric sealing material 44 that fills the
opening 24 and hermetically bonds to both the body member 12 and the
conductor pin 34. A suitable sealing material 44 is a sealing glass material that
can be fused in the opening 24 and to both the body member 12 and the
conductor pin 34. The sealing glass material 44 creates a non-conductive,
glass-to-metal seal that is also an airtight hermetic seal between the conductor
pin 34 and the body member 12 such that leakage through the hermetic terminal
10, by way of the conductor pin 34 and opening 24, is effectively prevented.
Suitable sealing glass materials are well-known in the art.
[0037] A layer of a dielectric material forming an insulating member 46
is disposed over the exterior surface 22 of the body member 12 and lower
portions 48 of the conductor pins 34 and is secured thereto by an insulating
adhesive or the like. The insulating member 46 covers and helps protect the
glass-to-metal seal and provides a dielectric over-surface covering for
substantial portions of the outside surface 22 of the body member 12 and the
conductor pins 34. The insulating member 46 can comprise silicone rubber.
[0038] Turning now to the hermetic terminals incorporating the pinisolating
feature 102, 202 of the present disclosure, exemplary embodiments of
the disclosed device are illustrated in FIG. 5 at 100 and in FIG. 6 at 200.
[0039] With reference to FIGs. 5, 7A and 7B, a first exemplary hermetic
terminal 100 incorporating a pin-isolating feature 102 of the present disclosure is
illustrated. The pin-isolating feature 102 forms part of the hermetic terminal 100
and serves to effectively increase the operative through-air spacing between the
terminal's conductor pins 34 (i.e., the effective through-air pin-to-pin spacing S3)
without necessitating a corresponding increase in the diameter of the pin circle
and/or the size of the terminal body member 12. Consequently, the power rating
for the hermetic terminal 100 can likewise be increased.
[0040] As illustrated, the pin-isolating feature 102 generally comprises
an integrally formed body 104 made from an insulating, dielectric material. The
body 104 of the pin-isolating feature 102 comprises a lower base portion 106 and
an upper barrier portion 108. The base portion 106 is sized and shaped to closely
fit the periphery of the exterior surface 22 of the bottom wall 14 of the body
member 12 of the hermetic terminal 100. The base portion 106 includes an upper
surface 110, a side wall 112 and an underside surface 114. The underside
surface 114 of the base portion 106 is offset or separated from at least a portion of
the exterior surface 22 of the terminal body member 12 and thereby creates an
inner cavity portion 116 forming a gap or space between the base portion 106 and
the exterior surface 22 of the terminal body member 12.
[0041] The pin-isolating feature 102 may comprise a moldable plastic
resin material, such as polyphenyl sulfide. A suitable material is generally
available under the tradename RYTON.
[0042] The base portion 106 of the pin-isolating feature 102 also
includes a plurality of openings 118 that both correspond to and align with the
plurality of openings 24 in the body member 12 of the hermetic terminal 100 and
correspondingly receive the plurality of conductor pins 34 of the hermetic terminal
100. As shown in the enlarged detail view of FIG. 7B, each opening 118 further
includes a neck portion 120, a first shoulder 122 that is adjacent to the neck
portion 120, and a second shoulder 124 forming a portion of the underside
surface 114 of the base portion 106 that is adjacent to the exterior surface 22 of
the bottom wall 14 of the terminal body member 12. At the neck portion 120, the
openings 118 are in close proximity fit with the conductor pins 34.
[0043] The upper barrier portion 108 of the pin-isolating feature 102
includes a central portion 128 and a plurality of generally vertically upstanding,
planar ribs 130. The central portion 128 comprises a cylindrical member having a
passageway 132 extending therethrough to the underside surface 114 of the base
portion 106.
[0044] The plurality of generally vertically upstanding, planar ribs 130
extend from the upper surface 110 of the base portion 106 in a direction along a
central longitudinal axis Z of the hermetic terminal 100 (which is generally parallel
to the longitudinal axes of the conductor pins 34). As illustrated in FIG. 7A, the
ribs 130 are shown generally to be rectangularly-shaped, having a length L, a
width W, and a thickness T. Although the ribs 130 are illustrated as rectangular,
the ribs 130 may take other geometric shapes. In the direction of the Z-axis, the
ribs 130 extend longitudinally from the base portion 106 for the length L and
terminate beyond the outer ends 36 of the conductor pins 34. In the direction of
the X-axis, the widths W of the ribs 130 extend laterally outwardly from the central
portion 128 to approximately the peripheral side wall 16 of the terminal body
member 12. As shown FIG. 5, the pin-isolating feature 102 includes three ribs
130 extending outwardly from the central portion 128 toward the side wall 16 of
the terminal 100 and equally spaced apart at approximately 120 degree intervals
to separate the three conductor pins 34 of the hermetic terminal 100. Of course,
depending on the configuration of the hermetic terminal 100 more or fewer
conductor pins 34 can be present, and the number and spacing of the ribs 130
can vary accordingly.
[0045] As shown in FIG. 5, the ribs 130 of the upper barrier portion 108
obstruct a direct, linear, through-air path between adjacent conductor pins 34 of
the hermetic terminal 100. As a result, any through-air path from one conductor
pin 34 to another conductor pin 34, as shown at lines 134 and 136, comprises a
non-linear path that traverses over and/or around the pin-isolating feature 102,
increasing the length of the through-air path between conductor pins 34.
[0046] Assembly of the pin-isolating feature 102 to the hermetic terminal
100 can be accomplished by securing it to the exterior surface 22 of the body
member 12 of the hermetic terminal 100. In this regard, a dielectric injection
molding material 138 is injection molded into the inner cavity portion 116. After
the injection molding material 138 has cured, the pin-isolating feature 102
becomes bonded to the hermetic terminal 100. Optionally, a dielectric adhesive
material 139 (such as an adhesion promoter or primer) can be applied to the
exterior surface 22 of the body member 12 and/or the inner cavity portion 116
and/or the conductor pins 34 prior to injection molding to promote good adhesion
between the injection molding material 138 and the body member 12 and/or the
conductor pins 34 and/or the pin-isolating feature 102.
[0047] In one exemplary embodiment, portions of the body 104 of the
pin-isolating feature 102 (e.g., the underside surface 114 and openings 118) and
the exterior surface 22 of the bottom wall 14 of the hermetic terminal 100 can
create a mold cavity for injecting the injection molding material 138 between the
pin-isolating feature 102 and the hermetic terminal 100. For example, the pinisolating
feature 102 can first be placed on the hermetic terminal 100 such that the
base portion 106 of the pin-isolating feature 102 covers the exterior surface 22 of
the body member 12 of the hermetic terminal 100. As previously described, the
inner cavity portion 116 is created and the inner cavity portion 116 can serve as a
mold cavity for the injection molding material 138. The injection molding material
138 can then be injected into the mold cavity through the passageway 132 in the
central portion 128 of the pin-isolating feature 102. The injection molding material
138 can flow to completely occupy the mold cavity, and excess injection molding
material 138 can flow out through the openings 118 and passageway 132, if
necessary. Once cured, the injection molding material 138 bonds to both the pinisolating
feature 102 and the hermetic terminal 100 (e.g., at both the exterior
surface 22 of the body member 12 and the exterior surface of each of the
conductor pins 34), securing the components together. The neck portions 120
and first shoulder portions 122 in the openings 118, and the passageway 132
through the central portion 128, assist in creating a suitably strong adhesive bond
by increasing the surface area on the pin-isolating feature 102 over which the
injection molding material 138 is exposed.
[0048] A suitable injection molding material for use with the invention of
the disclosure is liquid silicone rubber (LSR). In addition, a dielectric adhesive
primer material can also be used for promoting good adhesion between the
injection molding material 138, the pin-isolating feature 102 and the terminal 100.
[0049] In addition to the adhesive bond that affixes the pin-isolating
feature 102 to the hermetic terminal 100, the injection molding material 138 can
also create a mechanical connection with features of the body 104 to further
enhance the attachment of the pin-isolating feature 102 and the hermetic terminal
100. In this regard, and with reference to FIGs. 7A and 7B, the injection molding
material 138 can occupy the space of the openings 118 around opposite sides of
the neck portions 120 and between the respective neck portions 120 and
conductor pins 34. Further, just outside the openings 118 and adjacent to the
upper surface 110 of the base portion 106, upon curing the injection molding
material 138 can be formed into an enlarged retaining head 140. Similarly, the
injection molding material 138 can flow out of the passageway 132 of the central
portion 128 and, upon curing, be formed into another enlarged retaining head 142
against the upper barrier portion 108. The retaining heads 140, 142 can
strengthen the connection between the pin-isolating feature 102 to the hermetic
terminal 100 by serving the function of a mechanical fastener.
[0050] Referring now to FIG. 6, an alternative exemplary hermetic
terminal 200 incorporating a pin-isolating feature 202 of the present disclosure is
illustrated. The pin-isolating feature 202 preferably comprises an integrally formed
body 204 made from an insulating, dielectric material. Suitable materials for
forming the pin-isolating feature 202 are silicone rubber or polyphenyl sulfide.
[0051] As shown in the figure, the body 204 of the pin-isolating feature
202 comprises a lower base portion 206 and an upper barrier portion 208. The
base portion 206 is sized and shaped to fit over the exterior surface 22 of the
bottom wall 14 of the body member 12 of the hermetic terminal 200. In addition,
the base portion can include collar portions 207 covering portions of the exposed
surfaces of the conductor pins 34.
[0052] The barrier portion 208 comprises a plurality of generally
vertically upstanding, planar ribs 230 that extend from the base portion 206 in a
direction along a central longitudinal axis Z2 of the hermetic terminal 200 and
generally parallel to the longitudinal axes of the conductor pins 34. As illustrated
in FIG. 6, the ribs 230 are shown generally to be rectangularly-shaped, having a
length L2, a width W2, and a thickness T2. In the direction of the Z2-axis, the ribs
230 extend longitudinally from the base portion 206 for the length L2 and
terminate beyond the ends 36 of the conductor pins 34. In the direction of the X2-
axis, the widths W2 of the ribs 230 extend laterally outwardly from the central
portion 228 to approximately the peripheral side wall 16 of the terminal body
member 12. As also illustrated in FIG. 6, the pin-isolating feature 202 includes
three ribs 230 extending outwardly from the central portion 228 toward the side
wall 14 of the terminal body member 12 and equally spaced apart at
approximately 120 degree intervals. The ribs 230 obstruct a direct, linear,
through-air path between adjacent conductor pins of the terminal. As a result, any
through-air path from one conductor pin 34 to another conductor pin 34 comprises
a non-linear path that traverses over or around the pin-isolating feature, increasing
the distance of the through-air path between conductor pins 34, as illustrated at
234 and 236.
[0053] In this alternative embodiment, the pin-isolating feature 202 can
be secured to the exterior surface 22 of the body member 12 and to the
conductor pins 34 of the hermetic terminal 200 by a dielectric adhesive material
239 that is applied to the pin-isolating feature 202 (e.g., at the underside of the
base portion 206) and/or the terminal 100 (e.g., on the exterior surface 22 of the
body member 12 and/or the conductor pins 34) and provides good adhesion
between the pin-isolating feature 202 and the terminal 100.
[0054] The pin-isolating feature 202 also provides a dielectric oversurface
covering for substantial portions of the exterior surface 22 of the terminal
body member 12 and the conductor pins 34 and covers and helps protect the
glass seals 44.
[0055] Turning now to FIGs. 8, 9A and 9B, a connector block 300 for
use with the hermetic terminal 100, 200 incorporating a pin-isolating feature 102,
202 of the present disclosure is shown. The connector block 300 cooperatively
engages over the ends 36 of the plurality of conductor pins 34 of the hermetic
terminal 100, 200 and provides a mounting fixture for attaching to the hermetic
terminal 100, 200 lead wires (not shown) that can be electrically connected to a
power source (not shown) disposed on one side of the hermetic terminal 100,
200.
[0056] Referring to FIG. 8, the connector block 300 can comprise a
unitary plastic body 302 formed from a dielectric plastic material, such as a
phenolic. The body 302 generally comprises a T-shape and includes a central
passageway 304 and three spaced-apart channels 306, 308 and 3 10.
[0057] The central passageway 304 is sized and shaped to receive the
outer ends 36 of the conductor pins 34, including the connecting straps 40
attached to the conductor pins 34, and the pin-isolating feature 102, 202 of the
hermetic terminal 100, 200. Included in an outer periphery 3 12 of the central
passageway 304 are alignment slots or guideways 3 14 that cooperatively
engage with the ribs 130, 230 of the pin-isolating feature 102, 202 and
appropriately orient the connector block 300 relative to the hermetic terminal
100, 200.
[0058] A first, inner channel 306 is generally centered in the body 302
and has a lead wire opening 314 at one end thereof for accommodating a lead
wire (not shown). The first channel 306 includes an interior strap mounting
surface 3 16 and opposing side walls 3 18, 320. Located on each side of the first
channel 306 is a second, outer channel 308, 3 10, each second channel 308, 3 10
has an interior strap mounting surface 322. Bordering the outer periphery of
each second channel 308, 3 10 is an outer wall 324 which, in cooperation with a
corresponding side wall 3 18, 320 of the first channel 306, provides a lead wire
opening 326 at one end of each second channel 308, 3 10 for accommodating a
lead wire (not shown).
[0059] The interior strap mounting surfaces 3 16, 322 of the first and
second channels 306, 308, 3 10 serve as mounting locations for the connecting
straps 40 attached to the conductor pins 34 of the hermetic terminal 100, 200.
As seen in FIGs. 9A and 9B, the connecting straps 40 can be folded or bent over
so as to engage the strap mounting surfaces 3 16, 322. In addition, the interior
strap mounting surfaces 3 16, 322 also each include an aperture 328 for
accommodating a threaded insert 330. The threaded inserts 330 are engaged
by threaded fasteners (not shown) that electrically connect lead wires (not
shown) to the hermetic terminal 100, 200.
[0060] Example embodiments are provided so that this disclosure will
be thorough, and will fully convey the scope to those who are skilled in the art.
Numerous specific details are set forth such as examples of specific
components, devices, and methods, to provide a thorough understanding of
embodiments of the present disclosure. It will be apparent to those skilled in the
art that specific details need not be employed, that example embodiments may
be embodied in many different forms and that neither should be construed to
limit the scope of the disclosure. In some example embodiments, well-known
processes, well-known device structures, and well-known technologies are not
described in detail.
[0061] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not intended to be
exhaustive or to limit the disclosure. Individual elements or features of a
particular embodiment are generally not limited to that particular embodiment,
but, where applicable, are interchangeable and can be used in a selected
embodiment, even if not specifically shown or described. The same may also be
varied in many ways. Such variations are not to be regarded as a departure from
the disclosure, and all such modifications are intended to be included within the
scope of the disclosure.
CLAIMS
What is claimed is:
1. A hermetic terminal comprising:
a cup-shaped metallic body member including a generally flat bottom wall
and a peripheral side wall, the bottom wall having an exterior surface and a
plurality of first openings therein;
a plurality of current-conducting pins, at least one current-conducting pin
extending through each first opening;
a dielectric sealing material extending between and hermetically sealing
the current-conducting pins within the first openings; and
a dielectric pin-isolating feature attached to the body member comprising
a lower base portion and an upper barrier portion, the base portion being sized
and shaped to closely fit the periphery of the exterior surface of the bottom wall,
and the upper barrier portion comprising a plurality of generally verticallyupstanding,
generally planar ribs extending from the base portion in a direction
generally parallel to a central axis of the hermetic terminal and terminating beyond
the outer ends of the current-conducting pins; and
wherein the pin-isolating feature increases the operative through-air
spacing between the current-conducting pins.
2. The hermetic terminal of claim 1 wherein the base portion
comprises an underside surface that is adjacent to at least a portion of the exterior
surface of the body member so as to create a cavity between the base portion and
the exterior surface.
3. The hermetic terminal of claim 2 further comprising a dielectric
injection molding material occupying the cavity.
4. The hermetic terminal of claim 3 wherein the base portion
comprises a plurality of second openings respectively aligning with the plurality of
first openings in the body member;
wherein the plurality of current-conducting pins are correspondingly
received in the plurality of second openings.
5. The hermetic terminal of claim 4 further comprising a dielectric
injection molding material in the space between the second openings and the
current-conducting pins.
6. The hermetic terminal of claim 5 wherein each second opening
comprises a neck portion, a first shoulder adjacent to the neck portion, and a
second shoulder forming a portion of the underside surface of the base portion
that is adjacent to the exterior surface of the bottom wall of the body member;
wherein the neck portions of the second openings are in close proximity fit
with the respective current-conducting pins.
7. The hermetic terminal of claim 4 wherein the injection molding
material forms one or more enlarged retaining heads on the upper surface of the
base portion adjacent to one or more of the second openings.
8. The hermetic terminal of claim 1 wherein the upper barrier portion
further comprises a central portion including a cylindrical member having a
passageway extending therethrough to the underside surface of the base portion.
9. The hermetic terminal of claim 8 further comprising a dielectric
injection molding material in the passageway.
10. The hermetic terminal of claim 9 wherein the injection molding
material forms an enlarged retaining head outside the passageway and against
the central portion.
11. The hermetic terminal of claim 1 wherein the ribs are generally
rectangularly-shaped, having a length extending longitudinally from the base
portion and terminating beyond outer ends of the current-conducting pins and a
width extending laterally outwardly from the central axis of the hermetic terminal to
approximately the peripheral side wall of the body member.
12. The hermetic terminal of claim 1 wherein the terminal comprises
three current-conducting pins;
wherein the pin-isolating feature comprises three ribs extending from the
central axis of the hermetic terminal toward the peripheral side wall of the of the
body member and being equally spaced apart at approximately 120 degree
intervals; and
wherein the ribs separate adjacent current-conducting pins such that the
ribs obstruct a direct, linear, through-air path between adjacent current-conducting
pins.
13. The hermetic terminal of claim 1 wherein a through-air path
between the current-conducting pins comprises a non-linear path that traverses
over or around the pin-isolating feature.
14. The hermetic terminal of claim 13 wherein the pin-isolating feature
comprises an integrally-formed body comprising a moldable polymer material.
15. The hermetic terminal of claim 14 wherein the moldable polymer
material comprises polyphenyl sulfide.
16. The hermetic terminal of claim 13 wherein the base portion further
comprises an upper surface, a side wall, and an underside surface; and
wherein an injection molding material
wherein a dielectric adhesive material is included between the underside
surface and the exterior surface of the body member to attach the pin-isolating
feature to the body member.
17. The hermetic terminal of claim 13 wherein a dielectric adhesive
material is included between the base portion and the exterior surface of the body
member to bond the pin-isolating feature to the body member.
18. A hermetic terminal comprising:
a body including a wall having an exterior surface and a plurality of first
openings therein;
a current-conducting pin extending through each first opening, the pins
sealed within the openings and electrically isolated from the body;
a dielectric barrier attached to the body, the barrier sized and shaped to
closely fit the periphery of the exterior surface of the wall, the barrier comprising a
plurality of ribs, the ribs extending in a first direction generally parallel to a
longitudinal axis of the pins and terminating in the first direction beyond the outer
ends of the pins; and
wherein the barrier increases the operative through-air spacing between
the pins.
19. The hermetic terminal of claim 18 further comprising a dielectric
adhesive material between the exterior surface of the body and the barrier for
attaching the barrier to the body.
20. The hermetic terminal of claim 19 wherein a through-air path
between the current-conducting pins comprises a non-linear path that traverses
over or around the barrier.
2 1. The hermetic terminal of claim 19 wherein the barrier is integrallyformed
from a moldable polymer material.
22. The hermetic terminal of claim 2 1 wherein the moldable polymer
material comprises one of a phenolic or a liquid silicone rubber.
23. The hermetic terminal of claim 18 wherein the body further includes
a peripheral side wall; and
wherein the ribs extend in a second direction generally perpendicular to the
longitudinal axis of the pins and terminate in the second direction near the
peripheral side wall.
24. The hermetic terminal of claim 18 wherein the barrier further
comprises a base portion comprising an underside surface that is adjacent to at
least a portion of the exterior surface so as to create a cavity between the base
portion and the exterior surface.
25. The hermetic terminal of claim 24 further comprising a dielectric
injection molding material occupying the cavity.
26. The hermetic terminal of claim 25 wherein the base portion further
comprises a plurality of second openings respectively aligning with the plurality of
first openings;
wherein plurality of second openings respectively receive the plurality of
current-conducting pins.
27. The hermetic terminal of claim 26 wherein the dielectric injection
molding material occupies the space between the second openings and the
current-conducting pins.
28. The hermetic terminal of claim 27 wherein each second opening
comprises a neck portion, a first shoulder adjacent to the neck portion, and a
second shoulder forming a portion of the underside surface of the base portion
that is adjacent to the exterior surface of the bottom wall of the body member;
wherein the neck portions of the second openings are in close proximity fit
with the respective current-conducting pins.
29. The hermetic terminal of claim 27 wherein the base portion further
comprises an upper surface; and
wherein the injection molding material forms one or more enlarged
retaining heads at the upper surface adjacent to at least one of the second
openings.
30. The hermetic terminal of claim 25 wherein the barrier further
comprises an upper portion, the upper portion comprising the ribs and a central
portion comprising a cylindrical member having a passageway extending
therethrough to the underside surface of the base portion;
wherein the dielectric injection molding material occupies the passageway.
3 1 . The hermetic terminal of claim 30 wherein the injection molding
material forms an enlarged retaining head located outside of the passageway and
against the cylindrical member.
32. The hermetic terminal of claim 18 wherein the terminal comprises
three current-conducting pins;
wherein the barrier comprises three ribs extending from a central axis of the
hermetic terminal toward a peripheral side wall of the of the body, the ribs being
equally spaced apart at approximately 120 degree intervals; and
wherein the ribs separate adjacent current-conducting pins such that the
ribs obstruct a direct, linear, through-air path between adjacent current-conducting
pins.
33. The hermetic terminal of claim 32 wherein the shortest through-air
path between the adjacent current-conducting pins comprises a non-linear path
that traverses over or around the barrier.
34. A hermetic terminal comprising:
a body member comprising a generally flat bottom wall, the bottom wall
comprising at least first opening therein;
at least two electrically conductive pins, wherein at least one electrically
conductive pin extends through each of the at least one first openings;
a dielectric sealing material hermetically sealing the electrically conductive
pins within the each of the at least one first openings; and
means for increasing the operative through-air spacing between adjacent
ones of the electrically-conductive pins.
35. The hermetic terminal of claim 34 wherein the means for increasing
the operative through-air spacing comprises a dielectric pin-isolating feature
attached to the body member comprising a lower base portion and an upper
barrier portion, wherein the base portion is sized and shaped to closely fit the
periphery of an exterior surface of the bottom wall; and
wherein the upper barrier portion comprises a plurality of generally
vertically upstanding ribs extending longitudinally from the base portion in a first
direction and terminating in the first direction beyond the outer ends of the
electrically-conductive pins.
36. The hermetic terminal of claim 35 further comprising a dielectric
adhesive material between the exterior surface of the body and the base portion
for attaching the pin-isolating feature to the body member.
37. The hermetic terminal of claim 36 wherein the body member further
comprises a peripheral side wall; and
wherein the ribs extend laterally in a second direction generally
perpendicular to the first direction and terminate in the second direction near the
peripheral side wall.
38. The hermetic terminal of claim 36 wherein a through-air path
between adjacent ones of the electrically conductive pins comprises a non-linear
path that traverses over or around the pin-isolating feature.