Technical field
[0001] The present invention relates to cable-to-card connectors and more particularly to
a system for simplifying plugging and unplugging operations and for preventing any
risk of bending pins and damaging contacts first, by guiding male and female connectors
and second, by multiplying the operator insertion/extraction force.
Background art
Large Input/Output Connectors
[0002] The great progress realized these last years in the data processing technology allows
now the interconnection of numerous sub-systems with a constantly growing number of
input and output signals. The reduction of the overall size of connectors leads to
increase of the density of both pins and contacts. However, higher is the number of
transmitted signals per connection, more fragile and thinner are the pins and contacts.
The standard connectors which are the most frequently used, are manually inserted.
The retention of the cable connector is done mainly by means of mechanical devices
such as screws, springs, embossing or different kinds of latching.
Inserting Force
[0003] Figures 1 to 4 show an overview of the particular problems encountered by the plugging
and unplugging of large cable connectors. Large cable connectors (1) (more than 80
pins) are very often designed as an extension of small size connectors which, as for
them, can be easily plugged and unplugged manually. But the insertion force is directly
related to number of pins.
[0004] The improvement of the Radiated Frequency Interference (RFI), Electro-Static Discharge
(ESD), Electrical Fast Transient (EFT) behaviour of large connectors requires additional
contacts between male and female shells (16). These contacts are achieved thanks to
special embossing or springs on the male shell which also have, by sliding friction,
the adverse effect of drastically increasing the insertion force.
[0005] Therefore, it becomes very difficult for an operator to smoothly insert and remove
such assemblies. As described in Figure 2, the operator is forced to plug and unplug
the pins sequentially, by applying a kind of wavy motion. But, since the pins are
very fragile, this kind of unstraight motion may leads to contact damages (6) and
indirectly to machines misfunctions as show in Figure 4.
[0006] The connector latching systems very often increases the above problem. As shown in
Figure 1, the retention system the most frequently used consist of a couple of screws
(3) which fit in threaded studs (4) on the receiving connector (2). Most of time,
the operator has not the force to plug completely the connector and to complete the
job, he uses the retention screws (3) or other plugging tools. Instead of turning
the two screws at the same time, the operator tightens screws one after the other
which does not move the cable connector straightly but with an angle as shown in Figure
3. Pins follow the same motion and go in sockets with a wrong orientation which bents
pins (5) and opens female sockets (6) (Figure 4).
[0007] A system adapted to connectors having a small number of I/O is not endlessly expendable
to large connectors. There is a limit which depends upon a lot of parameters :
- connector shape,
- accessibility,
- contact technology,
- operator,
- etc...
[0008] To give an approximate limit, when the insertion force is above approximately 20
kg, an assisted device is highly recommended for plugging or unplugging male and female
connectors.
Plugging and Unplugging Operations
[0009] First, to prevent the risk of damaging contacts male and female contacts must be
plugged/unplugged by means of a linear translation, without any leading angle. Connectors
must move straight without any rotation as shown in Figure 1. Thus, A guiding device
is required for placing and maintaining the male and female connectors lined up during
the connection/disconnection operations.
[0010] Second, the insertion force of connectors with large number of pins is very important.
Most operators have a lot of difficulties to plug or unplug male and female connectors.
A device for multiplying the force of operators is required for exercising enough
pressure to insert the connectors or enough force to separate the connectors.
[0011] Finally, to avoid any tilting of connectors while their insertion or extraction,
the force must be applied in the connectors axis.
Summary of the invention
[0012] The object of the present invention is to smoothly plug and unplug large input/output
connectors without bending pins and damaging contacts.
[0013] It is a further object of the invention to compact.
- guide the cable and receiving connectors,
- multiply the operator's insertion/extraction force and
- center the forces on the connectors axis.
[0014] It is another object of the invention to design a cable connector which can be smoothly
plugged and unplugged on standard receiving connectors.
[0015] The cable connector comprises a fixed part with placing and maintaining means and
a movable part ensuring electrical contacts with the receiving connector. The fixed
part comprises pushing and/or pulling means for pushing and/or pulling the movable
part of the cable connector. The placing and maintaining means comprise guiding posts
to be fixed to the receiving connector and on which the movable part of the cable
connector can freely slide.
Brief description of the drawings
[0016] Figure 1 is a view of a theoretical good plugging motion according to prior art.
[0017] Figure 2 is a view of a realistic and current bad plugging motion according to prior
art.
[0018] Figure 3 is a view of a realistic and current bad contact mating according to prior
art.
[0019] Figure 4 is a view of a damaged and non damaged contacts according to prior art.
[0020] Figure 5 is a view in perspective of a connector comprising inserting and guiding
means according to the present invention.
[0021] Figure 6 is a partial section the cable connector according to the present invention
partially inserted in the receiving connector.
[0022] Figure 7 is a partial section of the cable connector according to the present invention
completely inserted in the receiving connector.
[0023] Figure 8 is a partial section of an unplugged connector according to the present
invention.
Description of the preferred embodiment
Plugging and Unplugging Device
[0024] The system for smoothly plugging and unplugging connectors according to the present
application consists of a special device installed on the cable connector. As described
in Figures 5 to 8, said device comprises two key elements :
1. a pair of guiding posts (10-11) one on each side of the cable connector (1),
2. a push-pull unique central screw (12-13) making the link between guiding posts
and the cable connector (1) itself.
[0025] The cable connector (1) (shell and contacts) is a regular commercial item as the
receiving connector (2) on the data equipment.
Guiding Posts
[0026] On each side of the cable connector, a post (10) is installed thru the connector
shell (16) and cover (if any). The cable connector is able to slides on the posts,
which can also freely move in rotation. As shown in Figures 6 and 7, post (10) is
guided by a metallic tube (11) which improves the guiding accuracy and stiffen parts.
Post ends (10a) on connector sides are threaded to fit in their nuts (4) counterparts
installed on the receiving connector (2). Other post ends (10b) are designed in such
way operator can turn them by hand and/or with a tool.
Push-pull Screw Device
[0027] The force to insert or extract the connector cable is handled by a unique central
screw (12). The screw is positioned in the connector axis, one side being attached
on a fix part (13) of the cable connector and the other side being attached on a movable
part of the cable connector (the connector cover (14)).
[0028] The rotation of said screw allows to move the cable connector along the two guiding
posts (10) and to insert or disconnect the two connectors (1 and 2) The translation
is obtained thanks to the central screw attached through the threaded hole on the
transversal beam (13) on the connector cover (or inner can when the assembly is overmolded),
by means of a pivot coupling (15) made of male/female shapes, free in rotation and
translation locked by a retaining spring ring.
[0029] This screw is centered in cable connector to give translation effort in the axis
without creating a rotation torque and a tilting of the connector and thus without
damaging the contacts. The screw (12) has a left fillet to insert the cable connector
when the operator turns it clockwise and to disconnect the connector when the operator
turns it counterclockwise.
Plugging Operation
[0030] As described in Figures 6 and 7, the plugging operation comprises the following steps
:
1. The cable connector (1) is first positioned all the way close to the transversal
beam (13) by turning the central screw counterclockwise.
2. The cable connector is then placed against the receiving connector (2).
3. The two guiding posts (10) are screwed onto the receiving connector fastening nuts
(4). The ideal way is to fasten the two screws at same time, but even if the operator
tightens one post and then the other, there is no risk of part damages, both connectors
being not in contact at that time.
4. After guiding posts (10) are installed, the central screw (12) is turned to move
forward the cable connector and to insert it in its receiving counterpart. The screw
pushes the cable connector in the axis and in straight line with the help of the guiding
posts. The pins (5) are smoothly inserted in the sockets (6) without damages. The
plugging operation requires no specific operator's effort, the central screw does
the job.
Unplugging operation
[0031] As shown in Figure 8, the unplugging operations comprises the following steps :
1. The central screw (13) is turned counterclockwise until the cable connector (1)
is disconnected from the receiving connector (2).
2. The two guiding posts (10) are turned counterclockwise and released.
3. The cable connector (1) is now fully released from the sub-system.
[0032] The push-pull device is back to its initial position, ready to be plugged again.
1. A cable connector comprising a terminal part with electrical contacts to be inserted
in a receiving connector, characterised in that it comprises :
means for placing and maintaining the cable and receiving connectors lined up during
the plugging or unplugging operations.
2. The cable connector according to claim 1 further comprising :
means for multiplying the operator's force on the cable connector during plugging
or unplugging operations.
3. The cable connector according to anyone of the preceding claims further comprising
:
means for centering operator's forces on the cable connector axis during the plugging
or unplugging operations.
4. The cable connector according to anyone of the preceding claims further comprising
:
a fixed part comprising the placing and maintaining means and a movable part ensuring
electrical contacts with the receiving connector.
5. The cable connector according to anyone of the preceding claims further comprising
:
pushing and/or pulling means attached on the fixed part of the cable connector for
pushing and/or pulling the movable part of said cable connector.
6. The cable connector according to anyone of the preceding claims wherein said placing
and maintaining means comprise :
guiding posts to be fixed to the receiving connector and on which the movable part
of the cable connector can freely slide.
7. The cable connector according to anyone of claims 2 to 6 wherein said means for multiplying
the operator's force on the cable connector comprises :
a screw, one side being attached on the fixed part of the cable connector and the
other side being attached on the movable part of said cable connector, the rotation
of the screw allowing the translation of the movable part along the guiding posts.
8. The cable connector according to claim 7 wherein said screw is centered and positioned
on the axis of the cable connector.