[0001] The present invention relates to a base for a relay.
[0002] There is a large variety of relays designed to perform different functions in existence
on the market. From the point of view of their connection they are subdivided into
two major groups: non-plug-in relays and plug-in relays.
[0003] All relays have external terminals, connected internally to components of the relay,
such as coils and contacts. It is generally accepted that the terminals connected
to the coil are called "input terminals" while those connected to the contacts are
called "output terminals"
[0004] Non-plug-in relays are connected to the operating circuit by directly soldering their
terminals to a printed circuit or circuit wiring.
[0005] Plug-in relays are connected directly to bases equipped with terminals and terminal
sockets, connected together within the base so that a connection is provided between
the terminals of the relay and the terminals.
[0006] There is a large variety of plug-in base, which correspond to different types of
relays. Here we refer by way of example to a standard model general-purpose baseplate
which can accept relays with eight or eleven pins, in a circular arrangement. Nevertheless
its applications as explained below are also appropriate for models other than the
one mentioned.
[0007] Initially relays were used as simple electromechanical components, but since the
appearance and development of control circuits containing semiconductors, relays have
fulfilled a complementary purpose in these circuits and have to be capable of acting
without causing damage to the associated semiconductors.
[0008] For this purpose it is necessary that means of protection be provided in the coil
and contact circuits in order to avoid transient overvoltage peaks or radiofrequency
emissions which can effect behaviour or even destroy delicate electronic logic circuits.
[0009] The trend in current technology with regard to the use of relays is to incorporate
various electronic circuits within the relay itself or within its base to carry out
the protective task described above, and also to incorporate more complex electronic
circuits which control the operation of the relay in a specific way, such as delay
circuits, sensor amplifiers, phase fault detectors and, in general, all types of logic
circuits, so that the relay acts as a resulting output from this logic.
[0010] All this diversity of electronic circuits offering this possibility is referred to
below as "auxiliary circuits".
[0011] There are three main ways of providing protection:
1) Installing these components within the relay in a fixed manner. This practice is
widespread at the present time and does not require any work for the fitter, but the
protection system cannot be replaced. It is only possible to fit very simple circuits
because of the small amount of space available.
2) Through the use of a circuit in module form, equipped with plug-in terminals which
can be associated with the internal terminals of the relay. This arrangement makes
it possible to replace the protective circuit immediately if necessary, in the place
where it is in use, but it has the disadvantage of the same space problem as the previous
method.
3) Inserting the auxiliary circuit in the plug-in base. This arrangement consists
of providing the circuit in a container module provided with terminals which plug
in to the input terminals of the base through openings made in the upper wall of the
body of the baseplate, establishing a connection with the relay coil.
[0012] The module is plugged in to the small space available between the body of the relay
and the block of base connection terminals with the result that with more complex
auxiliary circuits this space is insufficient and it is necessary to construct a narrow
and vertically elongated module.
[0013] This arrangement is precarious because it provides a space which is in any event
insufficient to house given components of a specific volume and also gives rise to
great instability in the connection when carelessly handled during maintenance, and
also through vibrations caused by operation of the equipment itself.
[0014] It is also impossible to establish a connection between the relay input (coil) and
output (contacts), as is necessary in some cases.
[0015] The purpose of this invention is to take advantage of the undoubted advantages of
the intermediate module, i.e. the non-existence of external connections, its possibility
for almost immediate functional replacement, fitting the standard dimensions for base
and overcoming their observed disadvantages, difficulty of handling and frequent sensitivity
to impact, above all.
[0016] According to the present invention, there is provided a base for a relay, comprising
a main body having a raised socket portion for receiving the pins of a plug-in relay
and an electronic module releasably coupled to the main body and provided with an
aperture through which the socket portion extends, wherein the main body and the module
are provided with complementary electrical coupling means for connecting circuit elements
in the electronic module to circuit elements in the main body.
[0017] Preferably, the module is received within a recess in the main body. The module may
be provided with lateral flanges which overhang the main body to assist removal of
the module therefrom. With this arrangement, when various bases are fitted together
a tunnel-shaped space is obtained between two adjacent baseplates, with sufficient
space for housing the direct connection wires between the input and output terminals
of the baseplate.
[0018] Additional space for electronic circuitry may be provided by arranging for the module
to include one or more raised portions extending away from the main body.
[0019] Either the main body or the module may carry the male part of the electrical coupling
means. It is also envisaged that the main body and module may be provided with complementary
mixes of male and female coupling parts as circumstances dictate..
[0020] Relay bases are typically fixed by screws which lock the base to a support. The module
is fitted over these screws with the advantage of providing active safety.
[0021] The module may also have an identification system, for the logic or control function
which it performs, on its front face, in the form of a label holder or plastic characters.
[0022] The aperture in the module, which matches the plug-in base of the relay, also serves
to centre the module on the base and as a central support therefor.
[0023] By comparison with the grip shape of modules located in the box in the lower part
of the base, it provides the following advantages: a double upper and lower arrangement
of the connecting pins, widely spaced and in opposite rows, against a single wire
and lateral connection. This wider spacing of the connection pins, plus the greater
surface area of contact between walls of the main body and the module and the reinforcing
support, together with the advantage of centering, and the cylinder supporting the
female connections of the base with respect to the module plate, show the improvements
due to this invention over conventional known arrangements.
[0024] Embodiments of the present invention will now be described, by way of example, with
reference to the accompanying drawings, in which:
Figure 1 shows a front view of a base and a module, with the box receiving the module
and its corresponding internal connections;
Figure 2 shows both side elevations of the base of Figure 1, in which a cut-out on
the side reveals the internal housing of the module;
Figure 3 shows another view of the base of Figure 1, but in this case with the module
incorporated into the body of the base;
Figure 4 shows cut away views of both side elevations of the base of Figure 1;
Figure 5 shows a side elevation of the base of Figure 1 with of the module supplemented
by two parallel blocks, located at its ends;
Figure 6 shows an aligned arrangement of various bases, in which the intermediate
tunnels housing the wires may be seen.
[0025] Referring to Figures 1 to 4, a base 1 for a relay has a rectangular prismatic main
body 2 located on its front face which incorporates a cylindrical boss 5 corresponding
to the projection of the supporting base for a relay, bounded by the two side walls
of the main body 2 and the protective wall for the two opposing external connection
wires.
[0026] The intermediate module 6 has a rectangular body with a central aperture 7 for receiving
the boss 5.
[0027] A front plate 8, with its boss 9 of the same dimensions as the plug on the opposite
face of the main body 2, serves as a grip and stop, and means for identification of
the type of circuit is provided thereon by means of label holders or standard plastic
characters 10.
[0028] The base plate itself has the two rows of openings 4 required for connection of the
terminal pins of the module 8, and two holes 3, intermediate between the two rows
for location of supporting screws.
[0029] This module 8 has two large opposing volumes tangential to the aperture 7, longitudinal
on the outside and circular on the inside, and another two small volumes at right
angles thereto with their tangents to the aperture 7, and therefore also perpendicular
thereto. This more than doubles the available space and provides sufficient space
for passing connections from one large volume to the other.
[0030] Referring to Figures 5 and 6, in those cases where the space occupied by the components
of the module requires it, it may be extended outwards, in parallel with the layout
of the relay, by means of symmetrical towers 11 located at the short sides of module
6.
[0031] This description has no need to be more extensive given that anyone skilled in the
art has sufficient information to understand the scope of the invention and its resulting
advantages, and to proceed with reproducing the same.
[0032] It is to be understood that, although this does not alter the essence of the invention,
both the materials and the shape, size and arrangement of the components are susceptible
to variation.
1. A base for a relay, comprising a main body having a raised socket portion for receiving
the pins of a plug-in relay, and an electronic module releasably coupled to the main
body and provided with an aperture through which the socket portion extends, wherein
the main body and the module are provided with complementary electrical coupling means
for connecting circuit elements in the electronic module to circuit elements in the
main body.
2. A base according to ciaim 1, wherein the module is received within a recess in the
main body.
3. A base according to claim 2, wherein the module is provided with lateral flanges which
overhang the main body to assist removal of the module therefrom.
4. A base according to claim 1, 2 or 3, wherein the module includes a raised portion
extending away from the main body.
5. A baseplate for a relay with an interposed electronic module of the type comprising
a baseplate rebated for insertion of the module, essentially characterised in that
the module, despite being incorporated in the box, comprises an intermediate module
between the relay and the baseplate (1), occupies the entire frontal surface thereof,
except for the area of the external connections of the baseplate and the location
for fitting the relay, the baseplate having a rectangular housing (2), two attachment
holes (3) on opposite sides, the openings (4) necessary for passage of the terminal
pins of the module, located conveniently to plug into the internal terminals of the
baseplate box from which there arises a cylindrical boss 95) for connection of the
relay, the intermediate module (6) comprising a rectangular body with a central opening
(7) and having a frontal plate (8) with a lateral projection (9) providing a grip
and stop for the module and support for the external wiring, housing (10) being provided
therein for insertion of standard plastic characters and two small adjacent perforations
for the insertion of a rectangular label identifying the whole.
6. A baseplate for a relay with an interposed electronic module according to the foregoing
claim, characterised in that the plate of the intermediate module has up to two prismatic
bodies (11) located on one or both of the short sides for the incorporation of additional
components of the module circuits within their internal space.
7. A baseplate for a relay with an interposed electronic module.
8. A base for a relay substantially as hereinbefore described with reference to Figures
1 to 4 of the accompanying drawings.
9. A base for a relay substantially as hereinbefore described with reference to Figures
5 and 6 of the accompanying drawings.