U.S. patent number 3,793,612 [Application Number 05/231,230] was granted by the patent office on 1974-02-19 for connector with unitary hinge.
This patent grant is currently assigned to Minnesota Mining & Manufacturing Company. Invention is credited to Aelred D. Driscoll.
United States Patent |
3,793,612 |
Driscoll |
February 19, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
CONNECTOR WITH UNITARY HINGE
Abstract
A connector including a body having an integrally formed unitary
hinge portion. The hinge portion connects a cover to a body member
for relative movement to a closed position. As the cover is closed,
material in the hinge portion deforms in at least two thin narrow
strips of material at the bases of parallel grooves. Strain within
each thin narrow strip is limited to a predetermined amount by the
angle between walls defining the groove.
Inventors: |
Driscoll; Aelred D. (North St.
Paul, MN) |
Assignee: |
Minnesota Mining &
Manufacturing Company (St. Paul, MN)
|
Family
ID: |
22868308 |
Appl.
No.: |
05/231,230 |
Filed: |
March 2, 1972 |
Current U.S.
Class: |
439/402; 16/225;
16/DIG.13 |
Current CPC
Class: |
H01R
4/2454 (20130101); Y10T 16/525 (20150115); Y10S
16/13 (20130101) |
Current International
Class: |
H01R
4/24 (20060101); H01r 013/38 () |
Field of
Search: |
;339/59-61,95,97-99
;16/150,DIG.13 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: McGlynn; Joseph H.
Attorney, Agent or Firm: Alexander, Sell, Steldt &
DeLaHunt
Claims
Having thus described the present invention, what is claimed
is:
1. In a connector for making an electrical connection between wires
including a resilient conductive contact element having spaced wire
receiving fingers, and an insulating body member of a polymeric
material having wire receiving cavities and a slot extending from a
first surface transverse to said cavities to slidably receive the
contact element for movement from a first position spaced from the
cavities to afford positioning wires therein, to an engaged
position with the fingers extending across the cavities to engage
wires therein; a cover having a second surface; a hinge portion
integrally formed with and connecting the body member and the cover
for movement of the cover from an open position with said surfaces
spaced to afford manual movement of said connector element to the
engaged position, to a closed position over the contact element
with said surfaces in contact; and latch means for latching the
cover in the closed position, the improvement wherein:
said hinge portion has converging walls defining at least two
spaced parallel grooves and an intermediate stiff hinge segment
having a generally triangular shape in transverse section and
extending parallel to said grooves, said segment being connected to
the body member and the cover by thin narrow parallel strips of
said polymeric material at the bases of the grooves; the strips
being deformable by an extent limited by contact between the walls
to afford movement of the cover to the closed position, and said
latch means includes a lip along the edge of said first surface
opposite said hinge portion, and a resilient hook-like edge wall
projecting from said second surface along the edge thereof opposite
said hinge portion and being adapted for latching engagement over
said lip when said cover is in the closed position, said lip and
edge wall each having an arcuate surface, and said arcuate surfaces
being positioned as said cover is moved toward said closed position
to engage each other to bias the cover away from said hinge portion
to a position defined by engagement between the walls defining one
of the said grooves, and to deflect said resilient edge wall to
produce engagement thereof over said lip.
2. A connector according to claim 1, wherein said hinge portion has
one hinge segment, and said walls are generally planar and define
an angle between the walls of each groove of about 90 degrees.
3. A connector according to claim 1, wherein said body member and
cover are relatively movable through an angle of about 180 degrees
between said open and closed positions, and the walls are planar
and define generally V-shaped grooves.
4. A connector according to claim 1, wherein said polymeric
material is polypropylene, and said strips have a thickness no
greater than about 0.03 inch.
Description
FIELD OF THE INVENTION
This invention relates to electrical connectors of the type having
integrally formed hinge portions.
BACKGROUND OF THE INVENTION
Hinge portions integrally formed with the polymeric body parts of
prior art connectors (e.g. U.S. Pat. Nos. 3,388,370 and 3,012,219)
can afford over 180 degrees of relative movement between the body
parts to attach the connector. This deformation occurs in a single
thin strip of material generally defining the axis of rotation for
the hinge portion. In polypropylene hinge portions this thin strip
undergoes a strain hardening during its first deformation which
improves its strength. After strain hardening the thin strip is
highly resistent to fracture even if the connector parts are
relatively moved over 180 degrees when the hinge portion is at a
low temperature (i.e. below 0.degree. Fahrenheit). However, it has
been found that if the first deformation of the thin strip occurs
when the hinge portion is at a temperature of below 0.degree.
Fahrenheit, the incidence of fracture is relatively high. Such
fracture detracts from the reliability of molded electrical
connectors.
This problem can be averted during production by flexing the thin
strip at room temperature before the connector is sold. This
procedure, however, adds cost, and may leave the connector parts in
unpredictable relative positions which may affect packaging
efficiency and be inconvenient for a craftsman using the
connector.
Additionally, certain countries have established flame resistent
requirements for electrical connectors. These requirements have
necessitated additives to polypropylene which detract from its
favorable deformation characteristics, or have required the use of
new materials. Many of these flame resistent materials do not
possess the favorable deformation characteristics of polypropylene,
so that even at room temperature they will not deform along a
single thin strip of the material without fracturing to afford 180
degree relative motion between portions parts of the connector.
SUMMARY OF THE INVENTION
An integrally formed hinge portion in a connector according to the
present invention distrubutes bending strain within the hinge
portion between two or more parallel, spaced thin strips of
material, and limits bending within any one thin strip of material
to a predetermined amount. The hinge portion can limit bending
strain in a thin strip of a given material to an amount which will
not produce fracture under anticipated use conditions so that
connectors having hinge portions of polypropylene or less
deformable materials need not be flexed during production even if
they may be used in below zero conditions.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be more fully understood after reading the
following description which refers to the accompanying drawing in
which like numerals designate like parts throughout the figures,
and wherein:
FIG. 1 is an enlarged fragmentary end view showing the unitary
hinge portion of a connector according to the present invention
with the hinge portion in an open position;
FIG. 2 is an enlarged fragmentary end view showing the unitary
hinge portion of FIG. 1 with the hinge portion in a closed
position;
FIG. 3 is a top plan view of the connector according to the present
invention with an open cover attached by the hinge portion of FIG.
1;
FIG. 4 is an end view of the connector of FIG. 3; and
FIG. 5 is an end fiew of the connector of FIG. 3 showing the cover
in the closed position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 3, 4, and 5 there is shown an electrical
wire connector 46 according to the present invention having a hinge
portion 12. The hinge portion 12 is integrally formed in the body
of the connector 46 and connects a first part or cover 50 to a
second part or body member 52 for 180 degree relative movement from
an open position (FIGS. 3 and 4) to a closed position (FIG. 5).
The hinge portion 12, body member 52 and cover 50 are one piece and
formed of a deformable polymeric material such as polypropylene.
When the body of the connector 46 is formed, (as by molding) a
first surface 70 on the cover 50 and a second surface 66 on the
body member 52 are coplanar with the cover 50 and the hinge portion
12 in the open position FIGS. 1, 3 and 4. The hinge portion 12
includes a generally triangular axially extending hinge segment 28
having its apex 30 approximately in the plane defined by the
surfaces 70 and 66 when they are coplanar. Two pairs of walls 26
define a pair of parallel V-shaped grooves 24 between the body
member 52 and the cover 50. The wall 26 are generally of equal
height, and a slight radius may be formed at the abase of each
groove 24. The thickness of the hinge portion 12 at the base of
each groove is not greater than 0.030 inch (preferably 0.015 inch)
along precisely located narrow strips 32. The polymeric material in
the strips 32 will deform to afford 180 degree relative movement of
the cover 50 and the body member 52 from the open position to the
closed position with the surfaces 66 and 70 in contact (FIGS. 2 and
5). The pair of walls 26 defining each groove 24 are disposed at a
predetermined angle to each other when the surfaces 66 and 70 are
coplanar. Relative movement of the cover 50 and the body member 52
toward the closed position will deform the material in a strip 32
until at least a portion of the walls 26 defining the associated
groove 24 contact. Thus the angle between the walls 26 defining
each groove 24 will determine the amount of bending strain which
will occur in the corresponding strip 32. As the hinge portion 12
is designed to afford 180 degree relative movement between the
cover 50 and body member 52, the walls 26 defining each groove 24
are disposed at about a 90 degree angle to equally distribute the
required strain in the hinge portion between the two strips 32 as
may be desirable to restrict fracture of the strips 32.
The connector 46 affords means for making an electrical connection
between the ends of a pair of wires. The connector 46 includes a
U-shaped conductive contact element 54 having spaced planar
parallel legs 56 with parallel aligned slots formed therein to
provide spaced wire engaging fingers 60. The insulative body member
52 is formed with a pair of parallel wire receiving cavities 62
extending into the body member 52 from inlet openings in the middle
of an end wall 57 to an opposite end wall 58. The cavities 62
communicate through openings 64 with the top or first surface 66 of
the body member 52 to afford inspection of the position of wires in
the cavities 62. The body member 52 is formed with a pair of slots
68 extending transverse of the cavities 62 from the first surface
66 on the body member 52. The slots 68 slidably receive the contact
element 54 for movement between a first position with the fingers
60 spaced from the cavities 62 to afford positioning the ends of
wires therein (FIG. 4), to a second position within the slots 68 at
which the fingers 60 may engage and electrically connect the ends
of wires in the cavities. In its open position, the cover 50 is
positioned with the inner surface 70 coplanar with and spaced from
the first surface 66 to afford access to the contact element to
move it to its second position (FIGS. 3 and 4). In the closed
position of the cover 50 (FIG. 5), a flexible hook-like edge wall
72 parallel to and opposite the hinge portion 12 is in engagement
over a lip 74, and the surfaces 66 and 70 are in contact with the
cover 50 over the openings 64 and the end of the engaged contact
element 54.
The connector 46 includes latching means to retain the cover 50 in
the closed position. The precisely located lines of bending
afforded by the strips 32 and contact of the walls 26 defining the
grooves 24 provide accurate positioning of the edge wall 72 when
the cover 50 has moved sufficiently close to the closed position
that an arcuate surface 76 along the edge wall 72 will contact an
arcuate surface 78 along the lip 74. Further pressure on the cover
50 to move it to its closed position will cause a camming action
between arcuate surfaces 76 and 78 and deflection in the edge wall
72 and the hinge portion 48 so that the edge wall 72 will move over
the lip 74 into latched engagement therewith to maintain the cover
50 in the closed position.
Hinge portions for connectors may include more than two hinge
segments, however the maximum number is limited as a practical
matter by the ability to form the thin hinge segments. Within this
limitation the number of strips 32 between which the strain should
be divided in a hinge portion is determined primarily by the
characteristics of the material in deformation and the angle of
relative movement to be provided by the hinge portion.
* * * * *