U.S. patent number RE32,805 [Application Number 06/933,560] was granted by the patent office on 1988-12-20 for rotatable electrical connector for coiled telephone cord.
Invention is credited to Anthony R. Engelmore, William H. Nold.
United States Patent |
RE32,805 |
Engelmore , et al. |
December 20, 1988 |
Rotatable electrical connector for coiled telephone cord
Abstract
The low friction rotatable electrical connector is for use with
a coiled telephone cord to prevent the cord from becoming twisted
or tangled during use. This connector is generally of insulating
material formed with a hollow housing for supporting a rotor
assembly therein. This rotor assembly is a hollow cylinder that is
positioned within the housing for relative rotation therein. One
end wall of the housing has a circular opening in which one end of
the rotor assembly is supported for rotation. The rotor assembly
has a single longitudinal split for nearly the entire length
thereof, but the split does not include the journal at one end that
is located within the circular opening or bearing in the end wall
of the housing. The rotor assembly supports a plurality of
continuous conductive rings on the exterior thereof, and there is
an insulating washer positioned between each pair of conductive
rings to serve as a spacer between adjacent rings. Each conductive
ring includes a separate insulated conductor on the underside that
extends through the split in the rotor. There are several
modifications of this invention, but each modification includes a
plurality of spring wire contact elements mounted within the
housing in a parallel array, where each wire contact element has a
portion biased into continuous wiping contact with one of the
continuous conductive rings for making a reliable electrical
connection. The housing includes partitions interposed between the
wire contact elements so as to stabilize and space them apart.
Inventors: |
Engelmore; Anthony R.
(Mechanicsburg, PA), Nold; William H. (Prospect, KY) |
Family
ID: |
27114163 |
Appl.
No.: |
06/933,560 |
Filed: |
November 18, 1986 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
743500 |
Jun 11, 1985 |
04583797 |
Apr 22, 1986 |
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Current U.S.
Class: |
439/26; 439/24;
439/676 |
Current CPC
Class: |
H01R
39/64 (20130101); H01R 13/26 (20130101) |
Current International
Class: |
H01R
39/64 (20060101); H01R 39/00 (20060101); H01R
13/26 (20060101); H01R 13/02 (20060101); H01R
035/00 () |
Field of
Search: |
;439/676,13,17-20,23-30 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Desmond; Eugene F.
Attorney, Agent or Firm: Shlesinger, Arkwright &
Garvey
Claims
What is claimed is:
1. A low friction rotatable electrical connector for use with a
coiled telephone cord, said connector comprising:
a. a hollow insulated housing of generally cylindrical form that is
split longitudinally into a base portion and a cover portion, and
assembly means for holding the base and cover portions together,
and a circular opening in at least one end wall of the cylindrical
housing;
b. and a cylindrical rotor assembly of insulating material having a
journal at one end that is rotatably mounted within the said
circular opening so the rotor assembly may rotate freely relative
to the hollow housing, the rotor assembly being a hollow
cylindrical member having a single longitudinal split in the wall
of the cylinder;
c. a plurality of continuous conductive rings mounted along the
length of the rotor assembly and separated by a plurality of
insulating washers, where there is a washer positioned between each
adjacent pair of conductive rings to serve as a spacer between the
rings, each conductive ring including a separate insulating
conductor on the underside thereof for extending through the
longitudinal split of the rotor extending out from the rotor
through the hollow journal to an external termination means;
d. a plurality of spring wire contact elements mounted within the
said base portion of the housing in a parallel array, each spring
wire contact element having a portion biased into continuous wiping
contact with one of the said continuous conductive rings for making
a reliable electrical connection between the relatively movable
hollow housing and its rotor assembly;
e. each of said plurality of spring wire contact elements being of
hairpin shape, the said cover portion of the connector housing
having a plurality of partitions to provide means to stabilize and
space the contact elements apart.[...]..Iadd.;
f. the plurality of spring wire contact elements has one group
extending vertically upwardly from the base portion to be at one
side of said rotor assembly and a second group extending vertically
upwardly from the base portion to be at the opposite side of said
rotor assembly, so that said rotor assembly is positioned between
the two groups of spring wire contact elements when the connector
is assembled; and,
g. the two groups of spring wire contact elements are formed by a
series of common pairs of spring wire contact elements, where each
common pair of contact elements engages a separate one of said
continuous conductive rings on the opposite sides thereof.
.Iaddend. .[.2. The invention as recited in claim 1 wherein the
said plurality of spring wire contact elements has one group
extending vertically upward from the base portion to be at one side
of the rotor assembly and a second group extending vertically
upward from the base portion to be at the opposite side of the
rotor assembly, so that the said rotor assembly is positioned
between the two groups of spring wire contact elements when the
connector is assembled..]. .[.3. The invention as recited in claim
2 wherein the said two groups of spring wire contact elements are
formed by a series of common pairs of spring wire contact elements,
where each common pair of contact elements enagages a separate one
of the said continuous conductive
rings on the opposite sides thereof..]. 4. The invention as recited
in claim .[.3.]. .Iadd.1 .Iaddend.wherein the single longitudinal
split in the wall of the cylindrical hollow rotor stops short of
the said journal
so that the journal is unbroken. 5. The invention as recited in
claim 4 wherein each spring wire contact element is of hairpin
shape, having an outwardly bowed upright section, where the top of
the contact element is formed at an reentrant angle that extends
downwardly as a vertical wiping contact portion for engaging the
side of one of the continuous conductive rings, wherein the spring
wire contact elements exert substantially equal opposing forces
against the opposite sides of the conductive rings to
provide a balanced rotating assemblage. 6. The invention as recited
in claim 5 wherein the said rotor assembly is furnished with a
journal on
both opposite ends thereof. 7. The invention as recited in claim 6
wherein a bearing is formed intermediate the length of the
connector housing to
support the innermost journal therein. 8. The invention as recited
in claim 6 wherein the opposite end wall of the connector housing
has a circular opening aligned with the circular opening in the
other end of the housing for supporting the two journals of the
rotor assembly within the circular bearings of these two end walls,
the said plurality of spring wire contact elements being molded
into the base portion of the housing, where each common pair of
contact elements is provided with external
terminal means extending through a sidewall of the base portion. 9.
The invention as recited in claim 7 wherein a circuit board means
is mounted within the said connector housing having a circuit
element for cooperation with each opposing pair of spring wire
contact elements, said circuit elements being joined to a second
plurality of spring wire contact elements at one end of the
connector housing that is opposite the said end wall that includes
the circular bearing for receiving the journal of the rotor
assembly, where this second plurality of spring wire contact
elements serve as terminal means within a female socket built into
that
end of the connector housing for receiving a male phone plug
therein. 10. The invention as recited in claim 9 wherein the said
partitions formed in the top cover portion of the connector housing
extend downwardly into the lower base portion and engage the top
surface of the circuit board for holding the circuit board firmly
in place in the assembled condition of
the connector. 11. A low friction rotatable electrical connector
for use with a coiled telephone cord, said connector
comprising:
a. a hollow insulated housing of generally cylindrical form that is
split longitudinally into a base portion and a cover portion, and
assembly means for holding the base and cover portions
together;
b. and a hollow cylindrical rotor assembly of insulating material
having a journal at each opposite end for supporting the rotor
assembly within the said housing for freedom of relative rotational
movement therebetween about a central longitudinal axis, the rotor
assembly having a longitudinal slot in the wall thereof;
c. a plurality of continuous conductive rings mounted along the
length of the rotor assembly, and separator means for spacing them
apart from each other, each conductive ring having a separate
insulated conductor integral therewith on the underside thereof and
extending through the said longitudinal slot, and each conductor
extending out one end of the rotor assembly and adapted for
connection between the rotor assembly rings and a standard phone
conductor;
d. a plurality of spring wire contact elements mounted within the
said base portion of the housing in a vertical parallel array, each
spring wire contact element being of hairpin shape having a free
end portion biased into continuous wiping contact with one of the
said conductive rings for making a reliable electrical connection
between the relatively movable housing and rotor assembly, one-half
of the spring wire contacts being on the two opposite of the rotor
assembly to balance the spring forces acting upon the rotor
assembly, the said spring wire contact elements having terminal
means that cooperate together for joining the housing contacts to a
standard phone connector;
e. the said cover portion of the housing having partition means
extending between adjacent spring wire contact elements to both
stabilize the contacts and space them apart.[...]..Iadd.; and,
f. the opposite end wall of the hollow housing has a circular
opening for
receiving the second journal of the rotor assembly. .Iaddend.12.
The invention as recited in claim 11 wherein there are four
continuous conductive rings mounted on the rotor assembly, and
there is an opposing pair of spring wire contact elements wiping
each conductive ring, where each opposing pair of contact elements
is joined together to be in common
with each other and having a single terminal means. 13. The
invention as recited in claim 11 where there is but a single spring
wire contact element in wiping contact with each continuous
conductive ring, where adjacent rings are furnished with spring
wire contacts on opposite sides
of the rotor assembly. 14. The invention as recited in claim 11
wherein one end wall of the cylindrical housing is furnished with a
circular opening for receiving the journal of the rotor assembly
therein, the housing having a bearing intermediate the length
thereof for receiving the second journal of the rotor assembly
therein. .[.15. The invneition as recited in claim 11 wherein the
opposite end wall of the hollow housing has a circular opening for
receiving the second journal of the rotor
assembly..]. 16. The invention as recited in claim 11 wherein the
said plurality of spring wire contact elements that are mounted in
the base portion is supported therein on a circuit board that is
clamped in place
by the cover portion of the housing. 17. The invention as recited
in claim 11 wherein the said plurality of spring wire contact
elements has fixed ends that are molded into the said base portion
of the housing, and these said spring wire contact elements have
terminal means that extend out through a sidewall of the base
portion for joining to a phone connector.
.Iadd.18. A low friction rotatable connector for use with a coiled
telephone cord, comprising:
a) a housing comprised of an insulating material and having an
opening extending therethrough between a first end and a second
end;
b) an insert comprised of insulating material positioned in said
housing;
c) a rotor assembly comprised of an insulating material journaled
in said housing for permitting rotation of said housing relative to
said rotor assembly;
d) a plurality of longitudinally spaced apart conductor means
disposed about said rotor assembly;
e) first circuit means extending from said rotor assembly, said
first circuit means including a plurality of first circuit elements
and each of said first circuit elements in circuit connection with
one of said conductor means;
f) a plurality of resilient contact means associated with and
extending from said insert, each of said contact means wipingly
engaged with one of said conductor means for maintaining circuit
connection therewith;
g) second circuit means disposed in said housing, said second
circuit means including a plurality of second circuit elements and
each of said second circuit elements in circuit connection with one
of said contact means and one of said circuit means for connection
with a telephone handset and the other of said circuit means for
connection with a telephone base for maintaining a continuous
circuit between the handset and the base;
h) said conductor means being disposed proximate one of said ends;
and,
i) each of said contact means including a first portion in wiping
contact with the associated conductor means and a second portion
extending therefrom to the other of said ends. .Iaddend. .Iadd.19.
The connector of claim 18, wherein:
a) said insert including a generally planar portion with a first
and a second surface and said insert extending substantially
between said first and second ends; and,
b) said first portions being disposed proximate said first surface
and said second portions being disposed substantially along said
second surface.
.Iaddend. .Iadd.20. The connector of claim 19, wherein:
a) each of said second portions including an apex proximate said
second end from which a third portion comprising a second circuit
element extends above said first surface. .Iaddend. .Iadd.21. The
connector of claim 18, wherein:
a) each of said first portions including a hairpin element for
maintaining wiping contact with the associated conductor means.
.Iaddend. .Iadd.22. The connector of claim 21, wherein:
a) there being at least four connector means and at least one
contact means for each conductor means;
b) said rotor assembly being centrally positioned relative to said
insert for dividing said insert into first and second side
portions; and,
c) said contact means first portion being disposed along said side
portions so that an equal number of contact means are positioned
along said first and second side portions. .Iaddend. .Iadd.23. The
connector of claim 22, wherein:
a) said rotor assembly being disposed above said first surface.
.Iaddend. .Iadd.24. The connector of claim 20, wherein:
a) means being associated with said insert engageable with each of
said third portions for maintaining positioning of said third
portions and preventing contact therebetween. .Iaddend. .Iadd.25.
The connector of claim 18, wherein:
a) said rotor assembly including aperture means extending
therethrough; and,
b) said first circuit elements each including a portion extending
through said aperture means. .Iaddend. .Iadd.26. The connector of
claim 18, wherein:
a) said rotor assembly including a cylindrical portion disposed
within said housing;
b) a plurality of annular recesses being disposed in said spaced
longitudinal relation along said cylindrical portion; and,
c) each of said conductor means being positioned in one of said
recesses so that adjacent conductor means are separated by an
insulating element. .Iaddend. .Iadd.27. The connector of claim 26,
wherein:
a) said conductor mean each being annular in plan and having an
outer diameter less than the outer diameter of said cylindrical
portion whereby said insulating elements position said contact
means and prevent contact between adjacent contact means; and,
b) said conductor means rotating on the axis of said rotor
assembly. .Iaddend. .Iadd.28. The connector of claim 19,
wherein:
a) means being associated with said housing for maintaining said
insert in said housing and for positioning said insert relative to
said rotor assembly. .Iaddend. .Iadd.29. The connector of claim 27,
wherein:
a) means being associated with each of said conductor means for
preventing
rotation thereof relative to said rotor assembly. .Iaddend.
.Iadd.30. The connector of claim 23, wherein:
a) said rotor assembly being rotatable on an axis disposed
centrally of said housing. .Iaddend. .Iadd.31. The connector of
claim 27, wherein:
a) said conductor means and said contact means being comprised of a
solderable copper containing material. .Iaddend. .Iadd.32. The
connector of claim 18, wherein:
a) said first circuit means including a male plug portion; and,
b) said second circuit means including a female receptacle portion.
.Iaddend. .Iadd.33. The connector of claim 32, wherein:
a) means being operably associated with said insert for journaling
said rotor assembly. .Iaddend. .Iadd.34. The connector of claim 18,
wherein:
a) said contact means and said second circuit means being integral.
.Iaddend. .Iadd.35. A low friction rotatable electrical connector
for use with a coiled telephone cord, comprising:
a) a housing comprised of an insulating material and having an
opening extending therethrough between a first end and a second
end;
b) a generally cylindrical rotor assembly comprised of an
insulating material journaled in said housing first end and
permitting rotation of said rotor assembly relative to said
housing;
c) a plurality of longitudinally spaced apart conductor means
disposed about said rotor assembly and rotatable therewith;
d) first circuit means extending from said rotor assembly, said
first circuit means including a plurality of first circuit elements
and each first circuit element having a portion in circuit
connection with one of said conductor means;
e) a plurality of resilient contact means positioned in said
housing and each contact means having a first portion in wiping
contact with one of said conductor means for maintaining circuit
connection therewith;
f) said contact means including circuit means extending towards
said second end and said second circuit means including a plurality
of second circuit elements and each of said second circuit elements
in circuit connection with one of said contact means and one of
said circuit means for connection with a telephone handset and the
other of said circuit means for connection with a telephone base so
that a continuous circuit is maintained between the handset and the
base;
g) said conductor means being disposed proximate said first
end;
h) said contact means including a second portion disposed proximate
said second end;
i) each second portion terminating in an apex proximate said second
end; and,
j) a third portion comprising a second circuit element extending
from said apex angularly disposed to the axis of said rotor
assembly. .Iaddend. .Iadd.36. The connector of claim 35,
wherein:
a) a plurality of recesses disposed about said rotor assembly and
said recesses being longitudinally spaced apart by an insulating
element; and,
b) each of said conductor means being mounted in one of said
recesses and said conductor means each being annular in plan and
having an outer diameter less than the outer diameter of said rotor
assembly so that the insulating element between adjacent recesses
positions said contact means apart and prevents contact between
adjacent contact means. .Iaddend. .Iadd.37. The connector of claim
25, wherein:
a) each contact means first portion being disposed generally
transverse to the longitudinal axis of said rotor assembly and said
second portion extending generally parallel to the axis of said
rotor assembly. .Iaddend. .Iadd.38. The connector of claim 35,
wherein:
a) each first portion including a hairpin having a portion in
wiping engagement with the associated conductor means. .Iaddend.
.Iadd.39. The connector of claim 35, wherein:
a) said rotor assembly being centrally positioned in said housing
and dividing said housing into first and second housing portions;
and,
b) each of said first portions being positioned in one of said
housing portions and there being an equal number of first portions
in each housing portion for maintaining said rotor assembly
centrally of said housing. .Iaddend. .Iadd.40. The connector of
claim 35, wherein:
a) said rotor assembly including central aperture means; and,
b) said first circuit means including a portion extending through
said aperture means. .Iaddend. .Iadd.41. The connector of claim 40,
wherein:
a) said first circuit means including a male plug portion; and,
b) said second circuit means including a female socket portion.
.Iaddend. .Iadd.42. The connector of claim 35, further
comprising:
a) an insert being removably positioned in said housing and
extending substantially between said ends;
b) said contact means extending along said insert; and,
c) means being operably associated with said insert for journaling
said rotor assembly. .Iaddend. .Iadd.43. The connector of claim 42,
wherein:
a) said insert having a substantially planar surface and said first
portion extending generally perpendicular to said surface.
.Iaddend. .Iadd.44. The connector of claim 43, wherein:
a) means being associated with said housing for maintaining said
insert in a preselected position; and,
b) the longitudinal axis of said rotor assembly extending parallel
to and spaced from said surface. .Iaddend. .Iadd.45. The connector
of claim 43, wherein:
a) said contact means each including a second portion extending
along said surface and terminating in an apex proximate said second
end; and,
b) a third contact portion comprising a second circuit element
extending from said apex at an acute angle to said surface and
being disposed adjacent a second surface of said insert parallel to
said first mentioned surface. .Iaddend. .Iadd.46. The connector of
claim 45, wherein:
a) said insert including an end wall portion proximate said second
end; and,
b) a plurality of grooves being disposed in said end wall, each of
said apexes being received in one of said grooves for maintaining
said contact means apart. .Iaddend. .Iadd.47. The connector of
claim 45, wherein:
a) means being associated with said insert for receiving said third
portions and for maintaining said third portions spaced apart and
for permitting said third portions to flex. .Iaddend. .Iadd.48. The
connector of claim 35, wherein:
a) said rotor assembly including a portion extending coaxially from
said conductor means; and,
b) means being positioned in said housing for rotatably receiving
said coaxial portion and thereby permitting rotation of said
housing relative to said rotor assembly. .Iaddend. .Iadd.49. The
connector of claim 35, wherein:
a) said contact means and said second circuit means being integral.
.Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the art of rotatable electrical
connectors for use with flexible electric cables, and particularly
for use with coiled cords that are widely used today on telephone
receiver for connecting the handset to the telephone base. One of
the advantages of coiled telephone cords is that they are able to
stretch for convenient use, while they retract into a compact
length when not in use. This rotatable connector of the present
invention is mainly for use with lightweight, light-duty telephone
cords rather than high voltage, high current electrical cable
system.
2. Description of the Prior Art
A thorough search of the prior art was made, and only one patent
was found relating to rotatable electrical connectors for the cords
of telephone receivers. Most, if not all, of the prior art
described heavy-duty commercial or industrial electrical
connectors.
The Larrabure U.S. Pat. No. 2,414,957 describes a swivel connector
for electric cables and cords for electric lamps, irons, vacuum
cleaners and telephone sets. One end of the connector comprises a
turning head that is shown fixed to a telephone handset. The main
connector body has a closed end and a central socket or bore. The
turning head has a ball bearing raceway with contacts with the
adjacent rim portion of the body. The internal electrical
conductors comprise a central rod and two concentric insulated
tubes, with a grooved roller on the innermost end of each
conductor. The main body has a plurality of radial, spring-biased
ball contacts, each cooperating with a grooved roller. These
spring-biased ball contacts are each provided with a wire conductor
external of the main body, and cooperating with a tubular loop
member.
The Mohr U.S. Pat. No. 3,195,094 relates to an electric cable
coupling comprising mutually concentric, rotatable units that are
capable of transmitting electrical current therethrough. Each
electrical circuit has an internal ring member surrounded by a
plurality of cylindrical rollers which are confined by an external
ring member, and this unit is held together by split rings or
helical springs. This design appears to have an excessive amount of
friction to restrain an easy turning action between the movable
parts.
The Norwegian Pat. No. 106,382, issued in 1965, appears to be
derived from the above-cited Mohr patent, or vice versa.
The German Pat. No. 1,152,459 describes a cable connector with
mutually concentric and rotatable parts for poly-phase current in
which a series of ball bearings is provided inside an insulating
housing. These ball bearings are under spring pressure, and they
carry the electrical current. An internal tube is provided which
holds a compact bundle of conductors that reach inside the
insulating housing. The number of conductors corresponds to the
number of electrical phases.
The Wendell et al. U.S. Pat. No. 3,599,165 describes an electrical
coupling device providing a series of continuous, unbroken,
unsliding electrical connections between two relatively rotatable
members over a limited angular displacement. There is a spiral
strip connector that is made of thin material having a relatively
low spring constant, that is capable of cyclic operation for a
sufficient large number of rotative displacements as desired
without excessive fatique and rupture.
The Hayward et al., U.S. Pat. No. 3,847,463 describes a cable
connector for electrically connecting a coaxial cable to a fixed
device, such as a coupler or amplifier, for use in a cable antenna
television system CATV which is adapted to accommodate drop leads
to individual subscribers' television sets.
The Charles et al. U.S. Pat. No. 3,972,577 describes rotating
electrical contacts in a device that is intended to be used on
apparatus submerged underwater at great depth where it would be
subjected to a high hydrostatic pressure. One example of such a
device would be a rotary antenna of panoramic sonars intended to
operate at great depth. This device also must be water-tight. This
patent uses mercury or an alloy of gallium and indium as the
conductive liquid.
The British Pat. No. 331,997 describes swivel connections for
electric cables using ball bearing rings. One metal ring has spring
wipe contacts that are adapted to press lightly on the face of the
opposite ring and provide continuous electric contact therebetween.
Apparently, the ball race is not an electrical conductor. There is
a ball and socket joint between the spindle of one member and the
spindle of opposite member.
OBJECTS OF THE PRESENT INVENTION
The principal object of the present invention is to provide a low
friction rotatable electrical connector for use with coiled
telephone cords without requiring ball bearings for rotation or
electrical continuity.
A further object of the present invention is to provide a rotatable
connector of the class described having a longitudinally split
hollow housing having a circular opening at one end for receiving
the journal of a rotor assembly for rotation with the housing,
where the rotor assembly includes a plurality of continuous
conductive rings spaced along the length of the rotor assembly,
while the housing supports a parallel array of spring wire contact
elements for cooperation with the conductive rings for maintaining
electrical continuity through the connector at all times.
A further object of the present invention is to provide a rotatable
electrical connector of the class described where the housing
includes a series of parallel partitions for stabilizing and
spacing the spring wire contact elements that are mounted within
the housing for cooperation with the conductive rings of the rotor
assembly.
A further object of the present invention is to provide a rotatable
electrical connector of the class described with the female
electrical socket built into one end of the connector housing, and
a male phone plug assembled to the journal-end of the rotor
assembly.
A further object of the present invention is to provide a rotatable
electrical connector of the class described with a circuit board
clampd with the split housing for supporting the spring wire
contact elements that make a continuous wiping contact with the
plurality of continuous conductive rings that are mounted on the
rotor assembly, as well as supporting a second plurality of spring
wire contact elements that serve as terminal means of the female
socket for receiving a male phone plug.
A still further object of the present invention is to provide a
rotatable electrical connector of the class described where the
plurality of spring wire contact elements for engaging the
continuous conductive rings of the rotor assembly are molded into
one-half of the split housing and are provided with a series of
parallel terminal ends extending from one side of the housing.
SUMMARY OF THE INVENTION
The present invention provides a low friction rotatable electrical
connector for use with coiled telephone cords, where the connector
has a hollow housing with a circular opening in at least one end
wall thereof for supporting the journal at one end of a rotor
assembly that is positioned within the housing. The rotor assembly
is a hollow cylindrical member having a single longitudinal split
for nearly the entire length thereof, except for the journal at one
end thereof. A plurality of continuous conductive rings are mounted
along the length of the rotor assembly and are spaced apart by an
insulating washer between each pair of rings, where each ring has a
separate insulated conductor on the underside thereof, where the
conductors extend through the journal and terminate in a male phone
plug. A plurality of spring wire contact elements are mounted
within the housing in a parallel array, where each wire contact
element makes continuous wiping contact with one of the continuous
conductive rings. Each wire contact element being of hairpin shape.
The connector housing has partitions interposed between the wire
contact elements so as to stabilize and space them apart.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention will be better understood from the following
description taken in conjunction with the accompanying drawings,
and its scope will be pointed out in the appended claims.
FIG. 1 is a top perspective view of standard telephone set provided
with a coiled telephone cord extending between the base and the
handset, where the low friction rotatable electrical connector of
the present invention is interposed between the upper end of the
coiled telephone cord and the handset.
FIG. 2 is a fragmentary perspective view, similar to the left side
of FIG. 1, showing the rotatable electrical connector of the
present invention mounted on the lower end of the coiled cord and
plugged into the base of the telephone set, rather than plugged
into the handset.
FIG. 3 is a fragmentary perspective view, similar to that of FIG.
2, showing the rotatable electrical connector of the present
invention mounted intermediate the length of the telephone
cord.
FIG. 4 is an exploded perspective view, on an enlarged scale,
showing the low friction rotatable electrical connector of the
present invention separated into its individal parts and arranged
in the manner in which they are joined together. The hollow housing
is split longitudinally into two parts; namely, the top cover that
is illustrated at the top of the Figure, and the base member that
is shown at the bottom of the Figure. Illustrated below the cover
is the rotor assembly, where one of the continuous conductive rings
is shown separated from the hollow cylindrical rotor. Also
separated from the rotor is shown one of the insulated washers for
spacing the rings from each other. Illustrated beneath the rotor
assembly is a circuit board shown supporting a plurality of
opposing spring wire contact elements at the right end and a
plurality of closely spaced, parallel spring wire contact elements
at the left end to serve as terminal means for the female socket at
the left end of the connector.
FIG. 5 is a transverse, cross-sectional, elevational view, on an
enlarged scale, taken on the Line 5--5 of FIG. 4, through one of
the continuous conductive rings that is mounted on the rotor
assembly.
FIG. 6 is a modification of the circuit board that was used in the
preferred embodiment of FIG. 4, where the plurality of spring wire
contact elements at the right end of the board are integral with
the plurality of closely spaced, parallel, spring wire contact
elements at the left side of the board.
FIG. 7 is a fragmentary front elevational view of the telephone set
of FIG. 1, left side only being illustrated, showing the rotatable
electrical connector of the present invention built into the
microphone of the handset, where the telephone cord has an end that
either plugs into the connector or is permanently fixed to the
rotor assembly of the connector.
FIG. 8 is an exploded perspective view of another modification of
the present invention which is related to the rotatable electrical
connector of FIG. 7 which is built into the handset. The circuit
board has been eliminated by mounting the plurality of spring wire
contact elements directly to the base of the housing at the same
time the base is molded of insulating material.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to a consideration of the drawings, and, in particular,
to the top perspective view of FIG. 1, there is shown a typical
example of a telephone set 10 as for use on a table or desk top.
This telephone set 10 has a base 12 which includes the dialing
mechanism 14. Separate from the base is a handset 16 which, of
course, has the earpiece 18 at one end and a microphone 20 at the
opposite end. This handset 16 is shown resting in a cradle 22 when
it is not in use. Of course, this is only one configuration of a
standard telephone set, and it is well recognized that there are
many variations of this configuration and that the number of such
configurations are growing rapidly. However, most telephone sets
have the relationship of a fixed base element and a movable
handset. The handset 16 is joined electrically to the base 12 by
means of a coiled telephone cord 26, as is conventional in this
art. Such coiled cords 26 are capable of stretching to several
times their normal length for the convenience of the user in moving
the handset 16 away from the base unit 12. One frequently heard
complaint in the use of coiled telephone cords, such as 26, is that
they become twisted and tangled during normal use until they reach
a condition where they will not expand or stretch as originally
designed, and then such cords become an annoyance rather than a
convenience.
The present invention relates to the discovery of several
modifications of a low friction rotatable electrical connector 28
for cooperation with the coiled telephone cord 26 to ensure that
the movement of the handset 16 away from the base 12 will not cause
a kink or twist to occur in the coiled cord. In FIG. 1, the
rotatable electrical connector 28 is connected at its left end 30
to a standard male phone plug 32 that is formed at the upper end of
the coiled cord 26. The right end 34 of the connector 28 is fitted
with a standard male phone plug 36 which is mounted into a standard
female receptacle 38 built into the microphone end 20 of the
handset 16. Notice that the lower end of the coiled cord 26 is also
fitted with a standard male phone plug 40 which connects into a
standard female receptacle 42.
Before going into a detailed description of the construction of
this rotatable electrical connector 28, mention will be made of
other possible locations for use of this connector, starting with
FIG. 2. The elements shown in FIG. 2 that are common to the
elements in FIG. 1 will be given the same reference numerals. In
the modification of FIG. 2, the rotatable electrical connector 28
has its standard male phone plug 36 at its right end 34 connected
into the standard female receptacle 42 in the base 12 of the phone.
The left end 30 of the connector receives a standard male phone
plug 40 supported on the lower end of the coiled cord 26. Notice,
the upper end of the cord 26 has its standard male phone plug 32
connected into the standard female receptacle 38 that is built into
the microphone 20 of the handset 16. Thus, in summary, in FIG. 1,
the connector 28 is connected into the handset 16, while in FIG. 2
the connector 28 is connected into the base 12.
In the third modification of FIG. 3, the rotatable electrical
connector 28 of the present invention is shown mounted intermediate
the length of the telephone cord 26. Another way of saying this is
that a length of coiled cord 26 is interposed between the rotatable
connector 28 and the female receptacle 38 in the microphone 20 of
the handset 16. This added length of coiled cord between the
connector and the handset could either be furnished with a male
phone plug 44 at each end, but the right end 34 of the connector
would have to be furnished with a female socket for receiving the
mating phone plug. Another alternative would be to have the left
end of the cord that fits into the right end 34 of the connector 28
in FIG. 3 connected permanently to the connector as original
equipment furnished by the factory.
In the fourth modification of FIG. 7, the rotatable electrical
connector 28 of the present invention is built into the microphone
end 20 of the handset 16, and the upper end 46 of the cord 26 is
connected permanently with one element of the connector 28, as will
best be understood with the description of FIG. 8.
The construction and operation of the preferred embodiment of the
low friction rotatable electrical connector 28 of the present
invention can best be understood from the exploded perspective view
of FIG. 4. There are four main elements in this connector 28;
namely, a hollow housing 52 of generally cylindrical form that is
molded of insulating material such as Delrin or Teflon, or some
equivalent self-lubricating type thermoplastic material. This
hollow cylindrical housing 52 is split longitudinally, as in 53,
into a lower base portion 54 and an upper cover portion 56;
although it will be understood that these parts are defined as
upper and lower portions depending upon the orientation of the
parts when disassembled. The third main element of this connector
is the hollow, cylindrical rotor assembly 58 that is adapted to be
mounted within the housing 52 for relative rotation therein. The
fourth main element of the connector 28 is the circuit board 60
that is arranged to be mounted in the base portion 54 for
supporting the internal circuit elements, to be explained.
The hollow, cylindrical rotor assembly is also a molded part of
insulating material, such as Delrin or Teflon. This rotor assembly
58 has a single longitudinal split 66 which extends for nearly the
entire length thereof but stops short of the right end 68 so as to
form a continuous journal 68 that is adapted to fit within a
circular opening 70 in the end wall 72 at the right end 34 of the
connector 28. It should be understood that this circular opening 70
is split through the centrally longitudinal split 53 so that the
lower half of this opening 70 is in the base portion 54, and the
upper half of this opening 70 is in the cover portion 56. Thus,
this circular opening serves as a bearing to receive the journal 68
of the rotor assembly 58 for relative rotational movement between
the journal and the bearing of low frictional characteristics.
This single longitudinal split 66 has a narrow width. A series of
four, continuous, conductive rings 74, of copper material or the
like are slipped onto the rotor assembly 58 from the left end. In
FIG. 4, three of these conductive rings 74 are shown mounted on the
rotor assembly 58, while the fourth ring 74 is illustrated spaced
from the left end of the rotor assembly and shown by itself so that
its construction can be viewed. Each copper ring 74 has soldered to
its interior surface a flexible insulated conductor 76, as shown at
78. Each insulated conductor 76 extends first through the split
opening and then longitudinally through the center bore 80 lf the
hollow, cylindrical rotor assembly 58. Near the soldered connection
78, the conductor 76 is formed at a right angle to extend through
the single longitudinal split 66 in the rotor, as is best seen in
FIG. 5. These four, continuous, conductive rings 74 must be
separated electrically from each other, and this is accomplished by
the use of a series of Delrin washer 82. Thus, three washer 82
separate the four conductive rings 74 from each other, and there is
an insulating washer 82 at each end of the series of rings for a
total of five insulating washers 82, as is shown in FIG. 4. Each
insulating washer 82 is provided with an indexing finger 84 on its
interior surface, and this finger is adapted to mate within the
single longitudinal split 66 which anchors the washer in place and
retards relative rotational movement between the washer 82 and the
rotor assembly 58, and the washers also tend to clamp the four
rings 74 in place so that they are fixed on the rotor assembly.
The left end 90 of the rotor assembly 58 is also formed as a
journal for supporting that end of the rotor within the hollow
housing 52. The base 54 of the housing is formed with a vertical
pillar 92, which is generally parallel with the end wall 72 of the
housing, and it is fitted on its top side with a semi-circular
bearing 94, which is generally the same as the lower half of the
circular opening 70 in the end wall 72, so as to receive the left
end journal 90 of the rotor 58 therein. Now, looking at the cover
56 of the housing 52, as seen in FIG. 4, the sidewall has been
broken away and shown with cross-hatching to illustrate an inverted
piller 96 which has an inverted, semi-circular bearing 98 on its
underside to complement the semi-circular bearing 94 and serve in
unison as a circular bearing for receiving the journal 90 of the
rotor 58.
The right end of the rotor assembly 58 is fitted with a flexible
sheath 100 of insulating material for receiving the four insulating
conductors 76 therethrough for ultimate connection with a standard
male phone plug 36. This sheath 100 would be attached in the end of
the center bore 80 of the rotor within the journal 68.
Next to be discussed is the printed circuit board 60 of FIG. 4. It
is also of insulating material, and it is of elongated rectangular
shape that extends for nearly the entire length of the hollow
housing 52. This printed circuit board 60 is designed to the
supported within the lower base member 54. The left end wall 30 is
furnished with a rectangular opening 106 which leads into a female
socket 108 for receiving a standard male phone plug 32, as
illustrated in FIG. 1. It should be recognized that the lower half
of this rectangular opening 106 is in the base 54, while the upper
half of this opening 106 is in the cover 56. Looking at the cover
56, the upper edge of the rectangular opening 106 includes an
indexing slot 110 that is adapted to receive the finger-operated
locking means (not shown) of a standard male phone plug, as is
conventional in this art. The left end 112 of the circuit board 60
is made narrow so that it fits within the opposing sidewalls 114 of
the female socket 108. The right end 116 of the circuit board 60 is
supported on a horizontal shelf 118 formed on the interior surface
of the right end wall 72 of the base 54. Parallel ledges 120 are
formed on the opposite sides of the interior of the base 54
adjacent the female socket 108 for supporting the circuit board 60
thereon. The top surface 122 of the circuit board 60 is adapted to
be generally flush with the lower edge 124 of the rectangular
opening 106 in the end wall 30 in the assembled condition of the
connector 28.
This printed circuit board 60 is provided with a first plurality of
spring wire contact elements 128 toward the right end of the board
for cooperation with the four, continuous, conductive rings 74 of
the rotor assembly 58, and a second plurality of spring wire
contact elements 130 at the left end of the board so as to be
disposed within the female socket 108 and to be in a position to
automatically engage with the circuit elements carried by a mating
standard male phone plug when it is coupled into the female socket
108.
The first plurality of spring wire contact elements 128 comprises a
series of four pairs of parallel, vertical, opposing contact
elements, where each pair of contact elements is identified as 132,
best illustrated in the transverse, cross-sectional, elevational
view of FIG. 5. Each pair of contact elements 132 is formed of a
single length of spring wire having a horizontal central section
134 which underlies the circuit board 60. Each end of this central
section 134 is turned upwardly, as at 136, to fit through a mating
hole in the circuit board. Each vertical section 136 is then formed
in a hairpin shape 138 having an outwardly bowed upright 140, which
has its upper end formed at a reentrant angle 142 which then
terminates as a vertical wiping contact 144 which is opposed to the
vertical wiping contact 144 of the opposite contact element of this
pair 132 so as to be in continuous wiping action with the
continuous conductive ring 74 of the rotor assembly 58. Thus, each
pair 132 of contact elements serve as opposing spring members for
exerting wiping contact action against the opposite sides of the
rings 74 so as to give a balanced effect of pressure exerted upon
the rotor assembly as it turns within the housing 52. The objective
is to provide equal spring forces exerted against the opposite
sides of the ring 74. Thus, it should be appreciated that this
first plurality of spring wire contact elements 128 comprises a
series of four pairs of opposing, vertical contact elements, where
each pair of contact 132 is arranged to be in parallel with the
other pairs of elements, as is clear from FIG. 4.
Each pair of opposing, vertical contact elements 132 is provided
with its individual printed circuit on the top surface 122 of the
circuit board 60. Looking at FIG. 5, the first pair 146 of
opposing, vertical contact elements 132 has a printed circuit 148
which starts near the right end 116 of the circuit board and joins
the two upright sections 136, which are soldered thereto, and then
it extends between the four series of pairs of contact elements
132, then extends along the right side edge of the board and
terminates at a vertical hole 150 in the board. The second pair 152
of opposing contact elements 132 has a printed circuit 154 which
extends lengthwise of the board and terminates at the vertical hole
156. The third pair 158 of contact elements 132 is provided with a
printed circuit 160 which terminates at the vertical hole 162.
Finally, the fourth pair 164 is provided with a printed circuit 166
which terminates at the vertical hole 168. It should be understood
that each pair of opposing, vertical contact elements 132 must be
soldered to their respective printed circuits and that this also
serves as a mounting means for the contact elements with the
circuit board 60. Suitable metal inserts 170 are arranged along the
near side of the circuit board 60 to provide for this solder
connection, as at 172.
The second plurality of spring wire contact elements 130 is four in
number, where each contact element is generally V-shaped, as seen
in a side elevational view looking along the plane of the circuit
board 60. The lower leg 178 of the V-shaped wire contact 130 is
positioned horizontally against the underside of the circuit board
60, and its free end 180 is turned up slightly to form a vertical
terminal that is adapted to fit into a mating hole, either 150,
156, 162 or 168, that is formed at the end of the various printed
circuits 148, 154, 160, and 166 respectively, and then soldered in
place. The apex 182 of each V-shaped wire contact 130 is adapted to
slip into a shallow notch 184 formed in the edge of the circuit
board 60 at the left end thereof to help to retain and stabilize
this spring wire contact 130 during use. The upper leg 186 of the
V-shaped spring wire contact 130 is formed at an acute, inclined
angle of about 25 degrees, and it is longer than the lower leg 178.
This second plurality of spring wire contact elements 130 is
arranged in a vertical, parallel array, but they are closer spaced
to each other than the spring wire contact elements of the first
plurality 128.
Thus, it will be seen that the right end 34 of the rotatable
electrical connector 28 of FIG. 4 is provided with a male phone
plug 36, while the left end wall 30 of the connector housing 52 is
provided with a female socket 108 for receiving a standard male
phone plug 32, all as illustrated in the assembly view of FIG. 1.
It will be understood by those skilled in this art that the split
housing 52 of the connector formed by the base 54 and the cover 56
must be sealed together during use. Adhesives could be used, or a
sonic welding technique to weld the mating surfaces of the single
longitudinal split 53. Another alternative would be to use a
push-on or a wraparound sleeve over the housing.
The base portion 54 includes a central vertical post 190 that is
generally rectangular in top plan view. This post is associated
with the vertical pillar 92 to cooperate with a rectangular opening
192 in the center of the circuit board 60 so there is a
close-fitting relationship between the vertical post 190 and
vertical pillar 92 on the one hand and the rectangular opening 192
in the circuit board on the other hand. Thus, this interaction
between the post 190 and pillar 92 with the rectangular opening 192
in the circuit board serves as a precision method of locating the
circuit board relative to the housing 52 and the rotor assembly 58.
As shown in FIG. 4, the top cover 56 is provided with a plurality
of parallel, transverse ribs 192 which are capable of extending
down into the base 54, and they have a lower surface 196 which is
adapted to seat upon the top surface 122 of the circuit board 60,
as is best seen in FIG. 5, for holding the circuit board down on
its shelf 118 and the parallel side ledges 120. These parallel,
transverse ribs 194 are space apart a slight amount to create an
area for receiving one of the spring wire contact elements of the
first plurality 128 therebetween so as to stabilize these contact
elements and space them apart.
Four, narrow, deep slots 200 are formed vertically in the top end
of the post 190, each slot for receiving the free end of the
inclined upper leg 186 of the spring wire contact element of the
second plurality 130, for retaining and spacing the spring wire
contacts apart for increasing the life expectancy of the terminals
within the female socket 106 of this rotatable electrical connector
28.
FIG. 6 shows a modification of the circuit board 60 in that it does
not have the printed circuit 148, 154, 160, and 166. Instead, there
is a first plurality of spring wire contact elements 202 arranged
toward the right end of the circuit board 60, and these are
integral with a second plurality of spring wire contact elements
204 that are arranged adjacent the left end of the board to serve
as the terminal means for the female socket 108. Remember, in the
preferred embodiment of FIG. 4, there was a pair of opposing,
vertical contact elements 132, as best seen in FIG. 5. In other
words, for four continuous conductive rings 74, there was a total
of eight vertical contact elements 128. In this modification of
FIG. 6, there is only one spring wire contact element 202 for each
continuous conductive ring 74. These wire contact elements 202 are
offset from each other; there being two contact elements at the
near side of the board and two contact elements at the far side of
the bard. Notice the metal inserts 205 formed on the top surface
206 of the circuit board 60 which cooperate with the base of the
wire contact elements 202 so that a soldered connection can be made
therebetween. An extension 208 connects the lower end of the wire
contact element 202 to the lower end of the contact element 204.
This extension 208 extends along the underside of the circuit board
60 in the modification of FIG. 6.
FIG. 8 shows another modification of the rotatable electrical
connector 28. The hollow housing 52 is split longitudinally,
generally through the center thereof, so as to form a lower base
portion 212 and an upper cover portioin 214. The left end wall 216
of the housing has a circular opening 218, half in the base and
half in the cover. The right end wall 220 of the housing has a
similar circular opening 222, where both openings serve as bearings
to receive the journals 224 and 226 on the opposite ends of the
rotor assembly 228, which is basically the same as the rotor
assembly 58 of the preferred embodiment of FIG. 4. One difference
is that one end of the rotor assembly 228 is furnished with one end
46 of a coiled telephone cord 26 so that the rotor assembly is
fixed with relation to this cord end 46. This rotor assembly 228
includes the single longitudinal split 66 and the plurality of four
continuous conductive rings 74 which are separated by the plurality
of insulating washers 82, as was described earlier with relation to
FIG. 4.
Looking at the base portion 212, it is molded with a plurality of
spring wire contact elements 232, which comprise a series of four
pairs of opposing, vertical contact elements 234, where each
contact element of a pair is in the form of a hairpin shape 236,
each having an outwardly bowed upright 238 formed with a top
portion at a reentrant angle 240 with a downwardly extending
vertical wiping contact 242 for engagement against the side of the
continuous conductive ring 74. The lower end of the pair of
opposing spring wire contact elements 234 is molded into the base
portion 212, as clearly shown in FIG. 8, and the wire is brought
together in a single terminal 244 for each pair of opposing contact
elements 234, and each single terminal is provided with a sleeve
246, where all four terminals 246 are arranged in a parallel array
at the near side of the base 212. Thus, a push-on connection can be
made between these terminals 246 of the connector 28 and the
internal circuits within the handset 16, as shown in FIG. 7. This
particular rotatable electrical connector 28 of FIG. 8 having
molded spring wire contact elements 232 into the base 212 is of the
type that would be built into the microphone section 20 of the
handset 16. Thus, this molded construction eliminates the circuit
board 60 of the modifications of FIGS. 4 and 6, and it also
eliminates the need for the female socket 108 of FIG. 4 or the male
phone plug 36 of FIG. 4.
Modifications of this invention will occur to those skilled in this
art. Therefore, it is to be understood that this invention is not
limited to the particular embodiments disclosed, but that it is
intended to cover all modifications which are within the true
spirit and scope of this invention as claimed.
* * * * *