U.S. patent number 3,750,087 [Application Number 05/192,040] was granted by the patent office on 1973-07-31 for preloaded electrical connector.
This patent grant is currently assigned to TRW, Inc.. Invention is credited to Ottomar H. Vetter.
United States Patent |
3,750,087 |
Vetter |
July 31, 1973 |
PRELOADED ELECTRICAL CONNECTOR
Abstract
Helical ramp grooves formed in the interior of a coupling ring
act against bayonets or pins mounted on one half of the electrical
connector to effect coupling with the other half. A specially
tapered spring washer becomes effective during the coupling
procedure to maintain a no-motion condition of the two components
after the contacts thereof have been fully mated. Additionally, a
plurality of detent balls are automatically shifted into a holding
position at the completion of the coupling action, thereby further
contributing to the maintenance of the mated or coupled condition
of the connector parts.
Inventors: |
Vetter; Ottomar H.
(Minneapolis, MN) |
Assignee: |
TRW, Inc. (Minneapolis,
MN)
|
Family
ID: |
22707986 |
Appl.
No.: |
05/192,040 |
Filed: |
October 26, 1971 |
Current U.S.
Class: |
439/318; 285/396;
403/349 |
Current CPC
Class: |
H01R
13/623 (20130101); H01R 13/595 (20130101); Y10T
403/7007 (20150115) |
Current International
Class: |
H01R
13/623 (20060101); H01R 13/62 (20060101); H01R
13/595 (20060101); H01R 13/58 (20060101); H01r
013/54 () |
Field of
Search: |
;339/89-91
;285/360,361,396 ;287/13A |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McGlynn; Joseph H.
Claims
I claim:
1. An electrical connector comprising first and second components,
each having interengageable contact means, coupling means for
advancing said first component with respect to said second
component to cause a portion of said first component to abut a
portion of said second component and to cause engagement of said
respective contact means, and spring washer means interposed
between a portion of said coupling means and another portion of
said first component which spring means is deflected solely by a
predetermined decrease in the distance between said last-mentioned
portions occurring only after said first-mentioned portions abut
each other, said spring washer means having an undeflected
thickness not greater than the distance between said last-mentioned
portions at the time said first-mentioned portions abut each
other.
2. The electrical connector defined in claim 1 in which said
coupling means is rotatable to advance said first component with
respect to said second component, a detent ring rotatable with said
coupling means having an axially directed hole therein, and a ball
shiftable partially into said hole when said first and second
components are fully coupled together.
3. The electrical connector defined in claim 2 in which said
portion of said coupling means includes a retainer ring rotatable
with both said coupling means and said detent ring, said spring
washer means including a deformable washer member disposed between
said rings.
4. An electrical connector comprising first and second components,
each having interengageable contact means, a rotatable coupling
ring for advancing said first component with respect to said second
component to cause a portion of said first component to bottom
against a portion of said second component when said coupling ring
is in one rotative position and to also produce engagement of said
respective contact means when in said one rotative position, a
threaded retainer ring rotatable with said coupling ring, and a
deformable spring washer engageable by said retainer ring to cause
deflection of said spring washer only between said one rotative
position of said coupling ring and a second rotative position of
said coupling ring which produces a complete coupling of said first
and second components, the axial position of said retainer ring
predetermining the amount of said spring deflection.
5. The electrical connector defined in claim 4 including outwardly
projecting bayonet means mounted on said first component, said
coupling ring having an internal ramp groove receiving said bayonet
means, said retainer ring being fixedly positioned in a spaced
relationship with said ramp groove so as to provide said
predetermined amount of deflection of said spring washer when said
coupling ring has been rotated between its said rotative
positions.
6. The electrical connector defined in claim 5 including outwardly
directed flange means on said second component and detent means
disposed axially between said outwardly porjecting means and said
spring washer, whereby said detent means assists said spring washer
in retaining said first and second components in their coupled
condition when said coupling ring has been rotated into said second
position.
7. An electrical connector comprising first and second shells of a
size such that an end portion of said second shell fits in an end
portion of said first shell, first contact means contained in said
first shell, second contact means contained in said second shell,
said second shell having an outwardly projecting flange engageable
by the end portion of said first shell when said first and second
contact means are mated, a coupling ring having an inwardly
projecting flange, interengaging bayonet and ramp groove means on
said first shell and said coupling ring for advancing said first
shell in a direction to cause its said end portion to abut said
outwardly projecting flange to reduce the axial spacing between
said flanges, a spring washer disposed in said space and
confronting said inwardly projecting flange, and means positioned
in said space between said outwardly projecting flange and said
washer for transmitting a compressive force against said washer to
partially flatten said washer against said inwardly projecting
flange only after the said end portion of said first shell abuts
said outwardly projecting flange.
8. The electrical connector defined in claim 7 in which said means
includes a detent ring confronting the other side of said spring
washer, said detent ring being longitudinally keyed to said
coupling ring and having at least one pocket therein facing away
from said washer, said outwardly projecting flange having at least
one recess therein, a detent ball carried in each of said recesses
of a size so as to only partially be received in said pocket when
rotation of said coupling ring has moved said pocket into angular
alignment with said recess and the detent ball contained therein,
and resilient means for urging said detent ball in the direction of
said pocket.
9. The electrical connector defined in claim 7 in which said
inwardly projecting flange is threadedly received in said coupling
ring.
10. The electrical connector defined in claim 9 in which said
inwardly projecting flange is fixedly secured within said coupling
ring at the proper location to preload said spring washer.
11. An electrical connector comprising first and second components,
each having interengageable contact means, coupling means for
advancing said first component with respect to said second
component to cause a portion of said first component to abut a
portion of said second component and to cause engagement of said
respective contact means, and spring washer means interposed
between a portion of said coupling means and another portion of
said first component which spring means is deflected by a decrease
in the distance between said last-mentioned portions after said
first-mentioned portions abut each other, said spring washer means
being preloaded and having a tapered cross section.
12. The electrical connector defined in claim 11 in which said
washer has a thicker outside diameter and a thinner inside
diameter.
13. The electrical connector defined in claim 11 in which said
spring washer means constitutes an annular washer having a thicker
outer diameter and a thinner inner diameter.
14. The electrical connector defined in claim 13 including detent
means for assisting said annular spring washer in the retention of
said components in their coupled relationship.
15. The electrical connector defined in claim 14 in which said
detent means includes a ball shiftable into a retentive
position.
16. An electrical connector comprising first and second shells of a
size such that an end portion of said second shell fits in an end
portion of said first shell, first contact means contained in said
first shell, second contact means contained in said second shell,
said second shell having an outwardly projecting flange engageable
by the end portion of said first shell when said first and second
contact means are mated, a coupling ring having an inwardly
projecting flange threadedly received therein, interengaging
bayonet and ramp groove means on said first shell and said coupling
ring for advancing said first shell in a direction to cause its
said end portion to abut said outwardly projecting flange to reduce
the axial spacing between said flanges, a spring washer having a
tapered cross section disposed in said space and confronting said
inwardly projecting flange, said inwardly projecting flange being
fixedly secured within said coupling ring at the proper location to
preload said spring washer, and means positioned in said space
between said outwardly projecting flange and said washer for
transmitting a compressive force against said washer to partially
flatten said washer against said inwardly projecting flange.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a preloaded electrical
connector, and pertains more particularly to a connector utilizing
a specially configured spring washer to maintain the connector
halves in their coupled condition.
2. Description of the Prior Art
Bayonets or pins and associated helical ramp grooves have long been
used for coupling together the two halves or components of an
electrical connector. In an effort to assure that the two
components remain coupled, the inner or closed ends of the grooves
have been provided in the past with offset notches or pockets into
which the bayonets move. While the retention goal has been achieved
with such prior art arrangements, this has been at the sacrifice of
other needed criteria. More specifically, there cannot be a
so-called bottoming of one connector component with respect to the
other. Also, the connector is vulnerable to vibration, wear and
also other factors resulting in partial or complete electrical
discontinuities. An example of a patent utilizing the notch or
pocket detent arrangement at the closed end of the helical ramp
grooves is U.S. Pat. No. 2,984,811 issued on May 16, 1961 to
Hennessey, Jr., et al.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a
preloaded electrical connector in which the likelihood of relative
motion between the connector parts is virtually eliminated. In this
regard, an aim of the invention is to provide an electrical
connector of the foregoing type in which there is a metal-to-metal
bottoming of the parts or components when mated so that little or
no wear results and, as a result of the lack of relative movement,
electrical discontinuities are avoided. It will be appreciated,
that once the parts of an electrical connector have been coupled
that they should not become inadvertently uncoupled, yet the
connector should permit ready uncoupling when it is desired to
separate the parts. Consequently, it is within the purview of the
present invention to provide a connector that will withstand a high
degree of vibration, large shock forces, and appreciable
temperature gradients or changes.
Another object of the invention is to provide an electrical
connector that will possess the above attributes, yet which will be
relatively inexpensive to manufacture. In this regard, it is
planned that a connector fabricated in accordance with the
teachings of the present invention will cost little more than a
conventional bayonet-type connector. Also, it is within the
contemplation of the invention to provide a connector that will be
long-lasting and exceedingly reliable during its entire life.
A further object is to provide an electrical connector that
requires very little manual force to effect the coupling thereof.
In this regard, the ramp grooves are configured or contoured so
that most of the mating travel occurs before any appreciable amount
of spring deflection occurs.
Yet another object of the invention is to provide a set of detent
balls that automatically become effective to assist the spring
washer in maintaining the connector in its coupled or mated
condition, the detent balls being shifted into their latching
condition near the end of the rotation of the coupling ring.
A further object is to provide an electrical connector that can be
easily assembled, and also wherein precise dimensions and spacings
need not be initially adhered to. More specifically, an aim of the
invention is to provide a means by which the loading of the
specially designed spring washer can be predetermined within
desired limits during the assembling procedure, a retainer ring
being threadedly positioned and secured in place to thereafter
furnish the correct amount of spring loading during subsequent use
of the connector.
Briefly, my invention comprises a spring washer having a tapered
cross section that is progressively deflected, reaching a desired
state of compression near the end of the coupling action. The
requisite deflection occurs after a metal-to-metal bottoming of one
connector component with respect to the other has been achieved.
While a bayonet and ramp groove arrangement is used in effecting
the coupling of the two connector components, the present invention
avoids the need for offset pockets or notches at the closed ends of
the grooves by reason of the retaining force exerted by the
compressed spring washer, thereby assuring that the above-mentioned
bottoming relationship is maintained. Provision is also made for
assisting the action provided by the flexed spring washer, a
plurality of ball detents being automatically shifted into an
interfering relationship so that they supplement the retentive
action of the washer. By reason of the improved mechanical
construction, electrical characteristics are also improved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of my electrical connector when
the parts are fully coupled together, a portion thereof being
broken away in order to show to better advantage the connector's
internal construction;
FIG. 2 is a fragmentary view corresponding generally to FIG. 1 but
illustrating the parts prior to a complete mating thereof;
FIGS. 3 and 4 are sectional views taken in the direction of lines
3--3 and 4--4 of FIGS. 3 and 4, respectively, for the purpose of
showing how the detent balls function;
FIG. 5 is a developed plan view of one of the ramp grooves formed
in the coupling ring, the leftmost phantom outline of one of the
bayonets or pins showing the entering of the bayonet or pin into
the groove and the other phantom position illustrating the point in
the bayonet travel where the spring washer starts to become
compressed, and the solid or rightmost position of the bayonet
illustrating the fully coupled condition of the connector
components at which point the washer has become sufficiently
deflected to assure retention of the connector parts in their
coupled relation, and
FIG. 6 is a graphical representation illustrating a typical working
range of the spring washer with percent spring force as the
ordinate and percent spring deflection as the abscissa, the solid
curve depicting a nominal value and the portions of the dash curves
within the working range lower and upper acceptable limits.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An electrical connector exemplifying my invention is denoted in its
entirety in FIG. 1 by the reference numeral 10. As is conventional,
a connector of this type includes two components or halves 12 and
14. In the illustrated instance, the component 12 comprises a rigid
shell 16 containing a rubber grommet 18, a rigid dielectric contact
retainer 20, a rubber insert 22 and a rigid dielectric block 24
formed with a forwardly directed integral lip or rabbet 26, these
members all being fixedly retained in the shell 16. The several
members 18-24 encompass and hold in place any preferred number of
socket contacts 28, the precise number depending upon the number of
conductors or wires 30 to be electrically connected. Although not a
part of the invention, a cable clamp 32 has been pictured which
encompasses the wires 30. The shell 16 is suggestively formed with
external threads at 34 for the attachment of the protective shroud
or sleeve 36 portion of the cable clamp 32. It will be perceived
from FIGS. 1-4 that the shell 16 is formed with an outwardly
projecting flange 38 thereon, serving a purpose later to be
referred to. The flange 38 is formed with a peripheral or
circumferential slot or groove 39.
Although the function thereof is not readily apparent at this stage
of the description, it can be pointed out that a plurality of
angularly spaced cylindrical holes 40 are also formed in the flange
38, extending from the right face of this flange to the
above-mentioned groove 39. Actually, four such holes 40 will
suffice and even three can be employed. Bowed in the direction of
each hole 40 is a wave washer 42 or spring residing in the groove
39. A detent ball 44 is housed in each hole 40. The detent balls
44, only one appearing in the drawings, are shifted into
interfering positions, as will hereinafter become clearer, to
assist in preventing inadvertent uncoupling of the connector halves
or parts 12, 14.
Describing now the component or part 14, it will be noted that this
half of the connector 10 includes a shell 46 having therein a
rubber insert 48 plus a dielectric contact retainer and grommet
(not shown but corresponding generally to the members 20 and 18,
respectively). Projecting from the insert 48 is a number of pin
contacts 50 that are cooperable or engageable with the previously
mentioned socket contacts 28 belonging to the component 12, the
block having appropriately spaced holes through which the pin
contacts 50 extend when mated with the contacts 28. The left ends
of the pin contacts 50 connect to a plurality of conductors or
wires 52. To permit mounting of the component 14, the shell 46 may
be provided with a flange 54 having suitable mounting holes 55
therein. The shell 46 has a number of radially projecting bayonets
or pins 56 thereon for a purpose explained immediately below.
At this time, attention is called to a coupling ring 58 having a
plurality of helical ramp grooves 60. Portions of one such groove
60 can be seen quite clearly in FIGS. 1 and 2, and the full groove
(in developed form) in FIG. 5. As should also be evident from these
three figures, one bayonet 56 extends into each ramp groove 60.
From FIGS. 1 and 2 it will be further discerned that the right end
of the coupling ring 58 is formed with internal threads 62. Secured
within the end of the coupling ring 58 by means of the threads 62
is a retainer ring 64, the ring 64 having external threads 66 that
permit its axial positioning within the coupling ring 58 to
whatever extent is necessary. It will become clearer as the
description progresses that the retainer ring 64 is initially
positioned properly during assembly and then appropriately secured
in place so as to become an integral portion of the coupling ring
58. Various techniques can be resorted to in the securement of the
retainer ring 64 so that it is not thereafter rotatable with
respect to the coupling ring 58. For instance, the retainer ring 64
can be staked or welded. Although the way it is held stationary is
relatively unimportant to a practicing of the invention, it is
imperative that its properly adjusted position be maintained. In
other words, the retainer ring 64 is not secured in place until a
certain longitudinal space or distance is provided between the
retainer ring 64, which serves as an inwardly projecting integral
flange, and the earlier mentioned outwardly projecting flange 38 on
the shell 16 of the component 12.
Performing a very important role in the practicing of the invention
is a specially configured spring washer 68. The thickness, material
and diameter determine the spring characteristics of the spring
washer 68. In this regard, it is to be observed that the washer 68,
which is annular, has a thicker outside diameter and a thinner
inside diameter. Furthermore, the inner periphery of the washer 68
is offset to the left of the outer periphery, as can be pictorially
appreciated from FIGS. 1 and 2. It is also thought that the
advantages to be derived from the incorporating of such a washer in
the connector 10 can be graphically understood and interpreted from
FIG. 6. From the solid curve labeled 70 in FIG. 6 it will be noted
that a considerable amount of spring force is needed to provide the
initial deformation of the washer 68 and similarly a large change
in force is needed to fully deform the washer up to about 50
percent of its total deflection capability. However, there is a
working range, typically between 0.008 and 0.015 inch of
deformation (for one specific model) where very little additional
spring force is needed to effect the deformation from the 0.008
inch condition to the 0.015 inch condition. Owing to the fact that
these figures depend upon connector dimensions, percentages have
been given in FIGS. 5 and 6, and even these percentage values
depend upon specific design characteristics and reliability
factors. The dashed curves 70a and 70b, it might be explained, are
intended to depict typical lower and upper acceptable limits, the
curve 70 actually representing a nominal value therebetween; here
again, though, the limits are only illustrative, demonstrating
mainly that limits can be easily obtained. The advantages to be
derived from this working range probably will be better understood
as the description progresses, especially when considering the
manner in which my connector 10 is coupled together.
As can be seen from FIGS. 1-4, there is a detent ring 72 having an
outer key 74 integrally formed thereon which projects radially into
a longitudinally directed keyway 76 formed in the interior of the
coupling ring 58. As its name implies, the function of the ring 72
is to coact with the detent balls 44; therefore, a plurality of
detent pockets 78, the number corresponding to the number of balls
44, are angularly disposed around the ring 72. However, the detent
pockets 78 are of smaller diameter than the balls 44 so that the
balls 44 cannot be fully received therein. Comparing the position
of the particular detent ball 44 appearing in FIG. 2 with that
appearing in FIG. 1 will illustrate that the shifting of the detent
balls 44 is such as to only cause segmental portions thereof to be
received in the pockets or passages 78; they never fully move into
the pockets 78.
In assembling the electrical connector 10, it is to be understood
that the detent ring 72 is inserted within the coupling ring 58,
the insertion being via the right end. Of course, the wave washer
42 and detent ball 44 are in place prior to inserting the ring 72.
The wave washer 42 is angularly positioned so that its crests
properly bear against the several balls 44 for the purpose of
biasing the balls to the right as viewed in FIGS. 1 and 2. The
spring washer 68 is next inserted so that one side confronts or
faces the detent ring 72. It is then that the connector 10 is in
readiness for the initial threaded advancement of the retainer 64
inwardly.
However, it is planned that a gauge tool be substituted for the
shell 46 during the assembling procedure. The gauge tool would
correspond generally in appearance to the shell 46. However, it
differs dimensionally inasmuch as the distance from the left side
of the pin or bayonet 56 appearing in FIG. 1 to the right end of
the shell 46 is somewhat less than the depicted distance of the pin
56 with respect to the right end of the shell 46. More
specifically, the gauge tool would be foreshortened so as to
compensate for the amount necessary to bring the washer 68 into its
working range, as pictorially represented in FIG. 5 and graphically
in FIG. 6. The alluded to working range has been denoted in FIG. 5
by the amount of advancement of the bayonet or pin 56 from its
intermediate position (shown in phantom outline) to the right hand
position (shown in solid outline), the right hand solid line
position denoting the point where the coupling of the connector 10
is fully completed. By indicating the working range in FIG. 6 on a
percentage basis, as far as the deflection of the washer 68 is
concerned, is believed to present a more generalized condition than
employing typical mil figures.
If the retainer 64 is now advanced so that it just contacts the
spring washer 68, then when the regular connector component or half
14 is employed, the spring washer 68 will be compressed or
deflected sufficiently so as to bring the requisite percent
deflection within the working range illustrated in FIG. 6. From
FIG. 6 it will be noted that a considerable percentage variation of
linear deflection is permissible without going below or above the
allowable working range limits. Assuming for the sake of discussion
that any force over 50 percent will be adequate to maintain the
connector 10 coupled, it can be seen from FIG. 6 that the percent
force for the working range is well above the 50 percent level,
actually being approximately 80 percent which provides an excellent
margin of safety under virtually all environmental conditions.
Consequently, a considerable amount of allowance is provided for
the wear of the various bayonets or pins 56 with respect to the
sides of the several ramp grooves 60. Further, it will be
appreciated that the mode of assembly described above compensates
for any geometric variations in the thickness and spacing of the
various parts such as the pins 56, the thickness of the flange 38
and the detent ring 72. It will also be recognized that the
inaccuracies or variations resulting from the machining of the ramp
grooves 60 and/or the locations of the pins or bayonets 56 are
automatically compensated for by reason of the assembling procedure
just described. This all is realized by virtue of the positioning
of the retainer 64 with the gauge tool in place. After the retainer
64 has been properly located, then its securement, such as by
staking or welding (as previously mentioned), will assure that the
position of the retainer 64 is maintained.
It is important to appreciate that the same deformation or
deflection of the spring 68 that is initially realized during
assembly will be repeatedly obtained each time that the components
12 and 14 are coupled together. The working range allows for a
considerable amount of bayonet and groove wear. It will also be
noted that not only is the same spring deformation realized, but
the metal-to-metal bottoming of the shell 16 against the shell 46
is re-established each time.
By proper machining of the keyway 76 in the coupling ring 58, it
follows that the detent ring 72 can be angularly oriented so that
the pockets or openings 78 will be in alignment with the various
detent balls 44 each time the parts 12, 14 are coupled together.
Consequently, when the coupling ring 58 is rotated or twisted to
couple the components 12, 14 together, the detent balls 44 will be
urged or shifted (under the influence of the wave washer or spring
42) to effect a segmental engagement thereof with the pockets 78.
It will be recalled that the pockets 78 are of lesser diameter than
the diameter of the detent balls 44, so the relationship appearing
in FIG. 1 is always established each time the components 12 and 14
are mated.
As can be understood from FIG. 5, it is only when the bayonets 56
approach the closed ends of their respective helical ramp grooves
60 that the spring washer 68 is compressed or deflected from its
preloaded state of deformation. Up to this particular point, which
is represented by the right hand dotted position of the particular
bayonet 56 in FIG. 6, there is little resistance to the mating or
coupling action. In other words, the camming performed by one side
of each helical groove 60 simply acts against the bayonets 56 to
pull or force the shell 46 into its mating relationship with the
shell 16. By correlating the point of compression or deflection of
the washer 68 with the approach of the bayonets 56 toward the end
of their respective grooves 60, the slope of the grooves 60 may be
lessened or made more gradual so that a greater mechanical
advantage is realized. Stated somewhat differently, the washer 68
requires only a few thousandths of compression or flattening in
order to become effective and this need only be obtained near the
ends of the grooves 60 where the slope is deliberately decreased,
thereby minimizing the amount of manual effort required to rotate
the coupling ring 58 under these terminating conditions.
When uncoupling or disconnecting the connector 10, a reverse
rotation of the coupling ring 58 moves the detent ring 72 so as to
force the partially received detent balls 44 out of the pockets 78.
However, until some manual twisting effort is applied to the
coupling ring 58, the detent balls 44, owing to the interfering
relationship they have, further assist in the prevention of
unwanted separation of the components 12 and 14. Once out of the
pockets 78, the detent balls 44 simply roll against the left face
of the ring 72 in a reverse fashion from that in which they roll
when the coupling is being effected. The washer 68 expands from its
compressed state during this happening until it reaches its initial
degree of compression determined by the proper positioning and
securement of the retainer ring 64, which functions as an inwardly
projecting flange as previously pointed out, during assembly.
Recapitulating, the space or distance between the flanges 38 and 64
is varied, being decreased during the coupling of the connector 10
and increased during the uncoupling thereof. However, when fully
coupled, the shell 16 will always bottom against the shell 46, more
specifically the flange 38 abuts the right end of the shell 46 as
is clearly evident in FIG. 1. Also, the detent or notch portions
previously provided in the prior art arrangements at the closed end
of the helical or ramp grooves are not needed. Thus, there is no
unwanted "backing off" by virtue of the detent notches previously
employed at the ends of the ramp grooves. Consequently, my
connector 10 resists vibration, shock and thermal gradients much
more effectively than those connectors relying upon detent notches
at the ends of the ramp grooves. Also, any deleterious effect
attributal to wear of the bayonets 56 or the walls of the grooves
60 is minimized because of the preloading.
* * * * *