[0001] This invention relates to the devices coupling plug and socket in multipolar connectors.
[0002] After a plug, connected to a multipolar electric cable, is inserted into the corresponding
socket, it is necessary to effect the locking between plug and socket which can prevent
the accidental withdrawal of the plug in the case of traction of the electric cable.
[0003] Devices are already known providing such locking; their working principle is based
on a pair of trigger action levers mounted astride of the shorter sides of the multipolar
socket and capable of rotating around the pin connecting them to the socket. Each
of the said levers has a pair of facing notches which, when rotated, snap into position
onto the corresponding pins provided on the body of the multipolar socket. Normally,
such levers are made of a single piece of plate and have a pair of holes aligned for
insertion of the hinge pin to the socket.
[0004] Assembly of the said coupling levers is performed in the following way: the lever
is moved towards the socket, making its holes coincide with the holes on the socket;
one pin is inserted, making it enter the accessible one of the two holes on the lever
and the socket, after having inserted a spring, consisting of a shaped metallic wire,
between the lever and the head of the pin. Finally the head of the pin is riveted
to make the connection irremovable. When this operation is completed, the socket is
rotated 180 degrees to give access to the other two holes on the socket and the lever,
and the assembly process is repeated for the second extremity on the lever.
[0005] The device described shows some drawbacks, such as:
a) the springs to be inserted between the lever and the pin are of the right hand
and left hand types, that is they are symmetrical, one with the other, but not equal;
this makes it necessary to have two series of springs available, complicating assembly
and increasing storage costs;
b) to assemble the lever onto the multiplar socket it is necessary to rotate the socket
which makes the possibility of mechanized assembly difficult and expensive.
[0006] Aim of the present invention is therefore the production of a coupling device which
is simple, sturdy and economical, and which allows the use of automatic assembling
equipment.
[0007] Said aim has been reached by producing a trigger action coupling lever for multipolar
sockets comprising two elastic side elements, identical with each other, rotatably
mounted on the socket, each one being connected to a side plate, the said plates being
joined to a connecting crosspiece.
[0008] In a preferred embodiment, each elastic side element is made with two identical springs
coupled together, locking said plate between them.
[0009] Preferably, the extremity of the lever which makes contact with the pin provided
on the plug is equipped with an idle roller.
[0010] One preferred solution provides an extension of the plate so as to form a limit stop
for the movement of the lever.
[0011] In another preferred embodiment, the springs are flat and semicircular ring shaped.
[0012] In this case the spring can widen at its extremities into two drilled ears and have
a semicircular drilled projection on its intermediate portion for fixing it to the
plate.
[0013] Finally, the crosspiece can be equipped with a name plate holder tab.
[0014] A preferred embodiment of this invention will now be described, with reference to
the enclosed drawings, in which:
Fig. 1 shows an overall shematic side view of the coupling lever which is the subject
of the present invention, mounted on a multipolar socket;
Fig. 2 shows a side view of a plate making up part of the lever which is the subject
of the present invention;
Fig. 3 shows a side view of one of the springs making up part of the lever which is
the subject of this invention;
Fig. 4 shows a side view of a spring roller making up part of the lever which is the
subject of the present invention;
Fig. 5 shows a top view of a crosspiece making up part of the lever which is the subject
of the present invention;
Fig. 6 shows a side view of the spring in figure 3 after mounting on the side plate
in fig. 2.
[0015] Figure 1 shows a connector with a multipolar plug 5, connected to an electric cable
C. The plug S is inserted into the corresponding socket P out of which comes a second
electric cable C′. The plug S and the socket P are locked by means of coupling levers
1, the subject of the present invention, which rotate around the pin 4, which is integral
with the socket P, and engage on the coupling pins A, being integral with the plug
S.
[0016] The proposed lever 1 comprises (figure 2) a shaped metallic side plate 2 with a circular
hole 3 for inserting the pin 4 for fastening it to the socket, and with further holes,
5 and 6 respectively, the first of which serves for fastening the crosspiece and the
second for fastening the spring 7. The hole 5 is located on a shaped extremity 2b
which can be received into a notch 17 provided on the crosspiece 11, as will be explained
later. The plate 2 also provides a ledge 2a which causes the lever to stop against
the pin A.
[0017] With reference to figure 3, a metallic spring 7 in the shape of a flat semicircular
ring can be seen, which widens at its extremities into two ears, 8 and 9 respectively,
each of which has a circula through hole. On its intermediary portion, the spring
7 has a semicircular projection with a circular through hole 10.
[0018] Figure 4 shows a roller 15, equipped with two pins 16 consistuting the hubs of said
roller.
[0019] Figure 5 shows a crosspiece 11, which can be made of plastic material, comprising
a bar 12 from which two arms 13a and 13b extend perpendicularly. A hub 12a provided
on the bar 12 can be used as connector identification plate holder. The arms 13a and
13b are each crossed by a rectangular sectioned notch 17 for receiving the extremity
2b of the plate 2. Into the notch 17 enters a circular sectioned projection 14, capable
of being received into the hole 5 at the extremity 2b of the plate 2. This projection
will represent the means for locking the crosspiece 11 to the plate 2. To facilitate
the introduction of the crosspiece 11 onto the plates 2, one wall 14a of the projection
14 is made sloping so as to form a guide when the crossplate is introduced onto the
plate 2.
[0020] The assembly of a pair of coupling levers 1 is carried out as follows: a side plate
2 and a roller 15 are taken and made integral with two springs 7 positioned one on
one side and one on the other side of the plate 2 and of the roller 15. Figure 6 shows
the side plate 2 on which the two springs 7 have been inserted, one on one side and
one on the other; only one of the springs is visible. The springs 7 are locked against
the plate 2 by riveting the pins 16 of the roller 15, which is mounted idle in the
holes 3 of the springs 7. In addition a rivet 21 is introduced and riveted into the
hole 6 on the side plate 2 which has come into a corresponding position with the hole
10 on the spring 7. The hole 9 on the spring is now placed over the hole 3. The units
thus formed are then brought close to the socket P to correspond with the two coaxial
holes provided on the opposite sides of the socket; next the two locking pins 4 are
inserted and then riveted. The crosspiece 11 is then brought close to the socket P
and the arms 13a and 13b of the crosspiece 11 are inserted into the two extremities
2a of the side plates 2. The projections 14 will make the crosspiece integral with
the plates 2.
[0021] To lock the plug to the socket it will be enough to operate the crosspiece 11 to
make the lever 1 rotate aorund the pins 4, until the side plates 2 engage on the locking
pins A. This will take place by elastically stressing of the springs. To unlock the
plug, the operation is repeated by rotating the lever 1 in the opposite direction.
[0022] It is clear how the invention described is capable of reaching the above-mentioned
aims; in fact the springs 7 and the plates 2 are of a type only, suitable for mounting
on both sides of the socket. The coupling lever 1 can be assembled by automatic devices
since the socket no longer needs to be rotated.
1. A trigger action coupling lever for multipolar connectors, comprising a socket
(P) equipped with a pin (4) around which the lever (1) rotates, and a plug (S), equipped
with a coupling pin (A), characterized in that the lever (1) comprises two elastic
elements (7), identical with each other, rotatably mounted on the socket (P), each
one being connected to a side plate (2), the said plates being joined by a connecting
crosspiece (11).
2. A lever according to claim 1, characterized in that each elastic element is made
with two identical springs (7) coupled together, between which the plate (2) is inserted.
3. A lever according to claims 1 or 2, characterized in that the extremity of the
lever (1) which makes contact with the pin (A) provided on the plug (S) is equipped
with an idle roller.
4. A lever according to any one of the preceding claims, characterized in that the
plate (2) extends in such a way as to form a ledge (2a) acting as a limit stop for
the rotatory movement of the lever (1).
5. A lever according to any one of the preceding claims, characterized in that the
springs (7) are in the shape of a flat semicircular ring.
6. A lever according to claim 5, characterized in that the spring (7) widens at its
extremities into two ears having holes (8, 9).
7. A lever according to claims 5 or 6, characterized in that a semicircular projection
is provided on the intermediate portion of the spring (7), having a hole 10 for fastening
it to the plate (2).
8. A lever according to any one of the preceding claims, characterized in that the
crosspiece (11) is equipped with a tab (12a) which can be used as a nameplate holder.