U.S. patent number 3,748,633 [Application Number 05/220,022] was granted by the patent office on 1973-07-24 for square post connector.
This patent grant is currently assigned to AMP Incorporated. Invention is credited to Robert Graham Lundergan.
United States Patent |
3,748,633 |
Lundergan |
July 24, 1973 |
SQUARE POST CONNECTOR
Abstract
The disclosure relates to an electrical terminal for making
electrical connection with a square post or the like within a
housing, the housing having a cavity of slightly larger dimension
than the normal dimension of the connector spring fingers. The
housing includes a pair of shoulders on which hooks or projections
at the end of the terminal spring fingers lock upon complete
insertion of the terminal within the housing. One spring finger
includes teeth thereon and the other spring finger includes a tooth
mateable with the teeth on the first finger in order to allow both
fingers to be pushed together to a great degree. The terminal is
designed so that the innermost portion of one of the spring fingers
is spaced from the innermost portion of the other of the spring
fingers by an amount less than the cross-sectional area of the
square post terminal to be inserted therein so that the projections
or hooks will be locked firmly on the shoulders upon insertion of
the square post.
Inventors: |
Lundergan; Robert Graham (Camp
Hill, PA) |
Assignee: |
AMP Incorporated (Harrisburg,
PA)
|
Family
ID: |
22821725 |
Appl.
No.: |
05/220,022 |
Filed: |
January 24, 1972 |
Current U.S.
Class: |
439/682;
439/748 |
Current CPC
Class: |
H01R
13/428 (20130101) |
Current International
Class: |
H01R
13/428 (20060101); H01r 009/08 () |
Field of
Search: |
;339/217R,217S,256R,256C,256A,256S,256SP,256T,258R,258C,258F,258P |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1,076,896 |
|
Jul 1967 |
|
GB |
|
1,184,254 |
|
Mar 1970 |
|
GB |
|
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Hafer; Robert A.
Claims
What is claimed is:
1. A multi-contact electrical connector for forming disengageable
electrical connections to a row of spaced-apart rigid terminal
posts, said posts being mounted in, and extending from, a panel
board or the like, said connector comprising:
a generally prismatic housing having a rearward face and a mating
face, a plurality of contact-receiving cavities extending through
said housing from said rearward face towards said mating face, said
cavities having inner ends which are proximate to said mating face,
said cavities having laterally extending branches at said inner
ends said branches opening onto the side edges of said mating face
and opening onto the sides of said housing which are on each side
of said mating face, said branches defining shoulders directed
towards said mating face,
a plurality of windows in said mating face, each of said windows
communicating with, and being centrally located with respect to,
one of said cavities,
a fork-type electrical contact terminal in each of said cavities,
each of said terminals comprising a stamped member having a yoke
portion and a pair of co-planar arms extending from said yoke
portion, said arms having oppositely directed hook portions on
their free ends, said hook portions extending into said branches
and being latched against said shoulders to prevent rearward
movement of said terminal from said cavity, and each of said
terminals being disposed against the rearwardly facing sides of one
of said windows to prevent forward movement of said terminal
through said cavity,
one of said arms having a single tooth and the other one of said
arms having two teeth, said single tooth being between said two
teeth, said teeth having contact crown portions, said contact crown
portions being spaced apart on opposite sides of said window and
being adapted to engage a contact post extending through each
window.
Description
BACKGROUND OF THE INVENTION
This invention relates to an electrical terminal and, more
specifically, to a terminal which is latchable within a housing of
a multi-contact connector and maintained in latched position by
means of a post which is wider than the space between the innermost
portions of the spring fingers of the connector.
Multi-contact connectors of various types have been well-known in
the electrical art. Such connectors find great utility when used in
connection with printed circuit boards of various types. One such
electrical connecting device including terminals is depicted in
U.S. Pat. No. 3,533,044 of Bauman et al. Terminals of the type
depicted in the prior art have suffered the problem of being
incapable of easy insertion into a housing or the like and at the
same time being capable of being securely latched in position. This
was caused by requiring that the spacing between the outer edges of
the terminal and the housing be sufficient to allow the fork type
spring connectors to flex inwardly during insertion. At the same
time, it was required that the spring terminals be able to move
outwardly in order that the hook members thereon be able to latch
on to the shoulder of the housing in order to provide a lock
therewith. For this reason, in one prior art device, it was
necessary that the spring terminals diverge outwardly, therefore
allowing contact with the housing only at the end portions of the
spring terminals. The connection therefore often had a great deal
of play and the electrical connection often provided a great deal
of contact resistance or other problems related to this
situation.
In accordance with the prsent invention, there is provided a
terminal having resilient arms, capable of flexing toward each
other, the end portion of one of the arms having an inwardly tooth
and the other arm having teeth into which the said tooth can move,
thereby allowing the arms to move closer together during insertion
then was capable of prior art terminals of this type. The terminal
is designed so that the distance between the innermost portions of
the two arms is less than the cross-sectional dimension of the male
post to be connected therewith and the arms are of only slightly
smaller dimension than the inner dimension of the housing cavity
into which they are to be locked. This causes a firm latching of
the hooks on the fingers with the shoulders of the housing and
eliminates most of the play between the male post and the terminal,
thereby eliminating the problems as mensioned hereinabove.
It is therefore an object of this invention to provide a terminal
capable of being latched in a housing without excessive play
between the terminal and housing.
It is a further object of this invention to provide a terminal
having a pair of spring arms, a portion of each of the spring arms
being capable of extending across an axis between the two arms
simultaneously.
The above objects and still further objects of the invention will
immediately become apparent to those skilled in the art after
consideration of the following preferred embodiment thereof, which
is provided by way of example and not by way of limitation,
wherein:
FIG. 1 is a section view of a housing and the terminal in
accordance with the present invention about to enter into the
housing;
FIG. 2 is a cross-sectional view of a housing with the terminal of
the present invention partially inserted therein; and
FIG. 3 is a cross-sectional view of a housing with the terminal of
the present invention fully inserted therein prior to insertion of
the male post.
Referring now to FIG. 1, there is shown a housing 1 having a
plurality of cavities 3 which extend from the rearward face (which
is on the right in FIG. 2) to the mating face, each cavity having
end walls 5 and 7. Branches extend from the inner end of each
caeity and open onto the upper and lower sides of the housing as
viewed in FIG. 2 and onto the mating face, these branches defining
forwardly facing shoulders 9, 11 for latching a terminal in the
cavity. The terminal 13 includes wire 15 secured thereto by a crimp
17. The terminal 13 includes a pair of arms 19 and 21 which are
resilient and have a spring-like action. The arm 21 includes a
tooth 23 which mates with two teeth 25 in the arm 19. The arms 19
and 21 also include hook portions 27 and 29.
With reference now to FIG. 2, there is a view of the partially
inserted terminal. It can be seen that the arms 19 and 21 are moved
together at the forward end thereof, the tooth 23 entering into the
teeth 25 to allow movement of the terminal within the cavity 3. The
terminal will continue to move inwardly toward the left as shown in
FIG. 2 until it reaches the position as shown in FIG. 3, whereupon
the hook portions 27 and 29 of the arms 19 and 21 are able to move
outwardly due to the outward spring bias of the arms 19 and 21,
thereby extending over the shoulders 9 and 11. The leftward
movement on the terminal 13 is terminated by the housing
restraining portions 30 and 31 which form window 32.
Referring now specifically to FIG. 3 it can be seen that, in the
unbiased free state the arms 19 and 21 extend substantially
parallel to the walls 5 and 7 and closely adjacent thereto. The
distance at that time between the inner edge of the tooth 23 and
the inner edge of the teeth 25 as depicted by the space between the
lines A--A will be smaller than the cross-section of a male post 35
as shown between the arrows B--B. In a typical embodiment, for
example, the space between the arrows A--A could be 0.015 inches
whereas the space between the arrows B--B could be 0.025 inches. As
the male post 35 moves inwardly between the members 30 and 31 of
the housing, the forward bevelled edges 37 and 39 thereof will move
against tooth 25 of the arm 19 and tooth 23 of the arm 21, thereby
forcing the hook portions 27 and 29 outwardly over the shoulders 9
and 11. Due to the resilient nature of the arms 19 and 21, the
hooks 27 and 29 will be locked against the walls 5 and 7 and over
the shoulders 9 and 11, thereby substantially eliminating any
possible play between the male post 35 and the terminal 13.
It should be noted that the individual terminals are retained in
their cavities, whether or not the connector is engaged with a row
of terminal posts, by virtue of the engagement of the hooks 27, 29
with the shoulders 9, 11. After the connector is coupled to a row
of terminal posts, it is impossible for the fingers of an
individual terminal to be moved towards each other because of the
presence of a post 35 between the fingers. This feature confers an
added degree of reliability upon terminals and connectors in
accordance with the invention.
It will be apparent from the foregoing specification that terminals
in accordance with the invention can be manufactured in extremely
small sizes by a straightforward stamping operation from brass or
other metal stock and connectors in accordance with the invention
can have their terminals located on closely spaced centers.
Terminals in accordance with the invention can, for example, be
stamped from brass strip having a thickness of 0.020 inches. The
overall length of a terminal intended for a rectangular 0.022 and
0.025 inch terminal post is 0.600 inches and such terminals can be
mounted in a connector housing on 0.10 inch centers.
Though the invention has been described with respect to a specific
preferred embodiment thereof, many variations and modifications
will immediately become apparent to those skilled in the art. It is
therefore the intention that the appended claims be interpreted as
broadly as possible in view of the prior art to include all such
variations and modifications.
* * * * *