[0001] The invention with which we are concerned pertains to a resistance module for contactors
of the type that employs two modules for each contactor phase and is connected between
each of the phases of the contactor and the corresponding phase of an auxiliary contact
block, so that the latter together with the resistors of each module protect the contactor
against current peaks when it is activated; and it is intended to provide greater
protection to the resistors when they have to be transported as well as when they
are in operation.
[0002] Another object of the invention consists of endowing the resistance modules with
a smaller volume, so as to reduce the packing space and therefore the cost of same,
as well the cost of transportation. From this standpoint, it can be deduced that less
space is necessary for installation, the unit being more compact.
[0003] Another object of the invention consists of endowing the module with a structure
capable of preventing mistakes at the time of making the connection.
[0004] In the state of the art, the use of contactor is extremely well known, each of whose
input phases is joined by means of resistors to the respective phases of an auxiliary
contact block, the output phases of the contactor likewise being joined to the corresponding
output phases of the auxiliary contact block, all in order to protect the contactor
on being activated, current peaks being limited.
[0005] Now, these resistors constitute independent components that are formed by a resistance
wire which must be of a certain length to provide the necessary resistance, so that
said resistance wire forms loops that project considerably from the contactor and
run from the input and output of each of the phases of the auxiliary contact block
to each of the inlet and outlet phases of the contactors, and, in case a three-phase
contactor is involved, six resistor loops are formed which project considerably from
the base connector and auxiliary contact block, so that they may undergo couplings
once installed, which represents a serious problem, at the same time as they occupy
a large volume, which is detrimental to their installation as well as transportation,
since on the same trip, a smaller number of these devices is transported, and packing
costs are higher.
[0006] Furthermore, the resistance wires have to be protected by means of a sheath, which
can fray, especially in the area of coupling with the contactor and, in addition,
a thermo-retractable sheath is needed to prevent the flash occurring on activation
of the contactor from breaking the resistor.
[0007] It is also to be indicated that the formation of these loops often facilitates bending
of the resistors, which can suffer damage during transportation, another disadvantage.
[0008] The fact that the resistors are so long and form these loops sometimes causes mistakes
to be made on connecting the phases, so that different phases are mixed during installation,
which represents a very serious problem.
[0009] To solve the problems indicated above, the invention provides a new resistance module
for contactors that is connected between each of the input and output phases of the
contactor and the corresponding input and output phases of an auxiliary contact block,
in order to protect the contactor when it is activated, the resistors consisting of
resistance wires.
[0010] Now, the invention is characterized in that it has means of support and winding of
a resistance wire, means formed by a flat body holding an insulator, on which the
resistance wire is in turn wound.
[0011] One of the ends of the means of support and winding of the resistance wire constitutes
the means of connection to one of the phases of the contactor, for which one of the
ends of the resistance wire is joined to the flat body, said means of connection being
formed by a tongue presented as an extension of the flat body.
[0012] The invention has means of coupling of the other end of the resistance wire to the
end of a flexible cable, the other free end of which is connected to the corresponding
phase of the auxiliary contact block.
[0013] It also has means of housing, retention and protection of the means of support and
winding of the resistance wire and of the end of the flexible cable joined to the
end of the resistance wire. These means of housing, retention and protection are formed
by a casing consisting of a body and a cover of insulating material, the latter having
interlocking claws in housings machined in the body of the casing.
[0014] The means of coupling of the end of the resistance wire to the end of the flexible
cable are preferably formed by a screw running through a small loop, formed at the
end of the resistance wire, and through an eyelet terminal integral with the end of
the flexible cable, the screw being threaded and retained in a nut housed in a receptacle
provided in the body of the casing.
[0015] In addition, the body of the casing is endowed with a cylindrical projection in which
the head of the screw is situated.
[0016] To accomplish the correct positioning of the flat body inside the casing, its body
has an interior pin that is inserted in a hole machined in the flat support.
[0017] In addition, the body of the casing and its cover have supplementary projections
that press the flat body and include supplementary ribs, all in order to accomplish
their complete and perfect locking.
[0018] The tongue for connection to the connector projects at the bottom of the casing and
the flexible cable, which is connected to the contact block, projects at its top.
[0019] This modular structure considerably reduces the space and volume occupied by the
present resistance module devices, so that, on connecting the tongue, the flexible
cable comes opposite the phase on which it is to be connected, preventing the presence
of errors in this operation.
[0020] The fact that the modules occupy a smaller volume means that, on transportation of
the unit formed by the modules, contactor and auxiliary blocks, a greater number of
units can be included, which reduces their cost, while making the packing simpler
and requiring less material, which also represents a lower cost.
[0021] Another characteristic of the invention resides in the fact that the casing has means
of retention of a crosspiece of sufficient length to couple the different modules
connected between each phase of the contactor and of the auxiliary contact block,
a compact module block being obtained.
[0022] The means of retention of the crosspiece in the body of each casing consist of at
least one groove provided in the body of each casing, in which a claw of a tongue
situated in the cross-piece fits and is retained. The crosspiece is inserted in different
grooves, depending on the pitch existing between the phases of each size of contactor.
[0023] This feature, aside from making it possible to obtain a compact module block, makes
for a sturdier unit.
[0024] An embodiment of the invention will now be described, by way of example, with reference
to the accompanying drawings, in which:
Figure 1 shows an exploded view in perspective of a resistance module for contactors
according to the invention.
Figure 2 shows a view in perspective of the resistance module of the foregoing figure
already assembled.
Figure 3 shows a view along a longitudinal section of the module of the foregoing
figure.
Figure 4 shows a rear view of the module of the invention, in which the cover has
been removed from the casing.
Figure 5 shows a view in perspective of the back part of the body constituting the
casing.
Figure 6 shows a view in perspective of three resistance modules for connection to
the three main phases of a contactor, which has been exploded and in which a crosspiece
can be seen that provides the coupling of said three modules.
Figure 7 shows a view in perspective of the resistance modules joined by means of
the crosspiece and mounted on the contactor and auxiliary contact block.
[0025] A description of the invention follows based on the figures referred to above.
[0026] The module of the invention has means of support and winding of a resistance wire
1, means formed by a flat body 2 holding an insulator 3, on which the resistance wire
1 is wound.
[0027] The flat body 2 is endowed with an extension forming a tongue 4 that is connected
to one of the phases of a contactor 14, for which one of the ends 5 of the resistance
wire 1 is integrally joined to the flat body 2, while the other end of the resistance
wire forms a small loop 6 that projects from the flat body 2 and is situated on an
eyelet terminal 7 integral with the end of a flexible cable 8.
[0028] In addition, the module has means of housing, retention and protection of the flat
body 2 and of the end of the flexible cable 8, means that are formed by a casing constituted
by a body 9 and a cover 10.
[0029] The body 9 is endowed with a receptacle 11 accommodating and retaining a nut 12,
in which screw 13 is threaded after running through the eyelet terminal 7 and the
small loop 6, physical and electric coupling being made between the resistance wire
1 and the flexible cable 8.
[0030] The other end of the flexible cable 8 is the one connected to the corresponding phase
of an auxiliary contact block 16.
[0031] The cover 10 includes a cylindrical projection 17 in which the head of the screw
13 is housed.
[0032] The body 9 has housings 15 and 18 opened outwards, so that claws 20 provided on tongues
19 of the cover 10 are retained in housing 15. A claw 21, which is also integral with
the cover 10, is retained in housing 18, so that a perfect closing of the cover is
achieved.
[0033] The flat body 2 is fastened by means of extensions 25 and 25, 31 and 30, situated
respectively on the body 9 and the cover 10 pressing on the flat support 2.
[0034] In addition, the body 9 has an interior pin 23 that is inserted in a hole 22 machined
in the flat support 2 in order to accomplish the correct positioning.
[0035] Ribs 32, 33, 34 and 35 have also been provided, which buffer the position of the
flat body 2 on body 9.
[0036] The casing is endowed with means of retention of a cross-piece 27, means formed by
a plurality of grooves 24 in which claws 28 of tongues 29 provided on the crosspiece
27 are fitted and retained, so that the crosspiece can be coupled to a plurality of
casings.
[0037] The tongues 29 are inserted in different grooves 24, depending on the pitch or separation
existing between the phases of each size of contactor, a compact block being obtained
for any of the sizes of contactor.
[0038] Thus, in the embodiment in Figures 6 and 7, a crosspiece 27 is shown, which makes
possible the union of three casings that are coupled to the three main phases of a
contactor 14.
[0039] It is easily understandable from the description given that, after connecting the
tongue 4 on the corresponding phase of the contactor 14, the flexible cable 8 comes
opposite the corresponding phase of the auxiliary contact block 16, so that it is
prevented from being connected on a wrong phase.
[0040] At this point, it is important to point out that the casing (body 9 and cover 10)
has a narrowing 36 through which, after connecting the modules on the corresponding
phases of the contactor 14 and auxiliary contact block 16, the different phases of
the contactor can be connected to the network.
[0041] The structure described has a reduced volume compared to conventional modules, which
accounts for the advantages already discussed.
1. Resistance module for contactors that employs two modules for each contactor phase
(14) and is connected between one of the phases of the contactor (14) and the corresponding
phase of an auxiliary contact block (16), so that the latter together with the resistor
of each module protect the contactor (14) when activated, the resistor of the module
consisting of a resistance wire, the module comprising:
a winding support means with a winding of a resistance wire thereon, one of the ends
of the winding support means constituting the means of connection to one of the phases
of the contactor (14), for which one of the ends of the resistance wire (1) is joined
to said winding support means;
means for coupling the other end of the resistance wire (1) to the end of a flexible
cable (8), the other free end of which is connected to the corresponding phase of
the auxiliary contact block (16); and
housing means for retaining and protecting the winding support means and the end of
the flexible cable (8) joined to the end of the resistance wire (1).
2. Resistance module for contactors according to Claim 1, wherein the winding support
means comprises a flat body (2) holding an insulator (3), on which the resistance
wire (1) is in turn wound.
3. Resistance module for contactors according to Claim 1 or Claim 2, wherein the end
of the winding support means forming the means of connection to one of the phases
of the contactor (14) is determined by a tongue (4) that is presented as an extension
of the flat body (2).
4. Resistance module for contactors according to Claim 1, wherein the housing means comprises
a body (9) and a cover (10), which has interlocking claws (20 and 21) in housings
(15 and 18) machined in the body (9).
5. Resistance module for contactors according to Claim 4 wherein the body (9) has an
interior pin (23) that is inserted in a hole (22) machined in the flat support (2)
in order to accomplish the correct positioning, the flat body (2) being locked by
means of extensions (25 and 26, 31 and 30) respectively provided on the body (9) and
the cover (10) and pressing on the flat body (2).
6. Resistance module for contactors according to any one of Claims 1 to 4 wherein the
means of coupling of the ends of the resistance wire (1) to the flexible cable (8)
are formed by a screw (13) running through a loop (6), formed at the end of the resistance
wire (1), and through an eyelet terminal (7) on the end of the flexible cable (8),
the screw (13) being threaded and retained in a nut (12) located in a receptacle (11)
provided in the body (9) of the casing, the cover (10) further having a cylindrical
projection (17) in which the head of the screw (13) is situated.
7. Resistance module for contactors according to claim 3 wherein the tongue (4) connecting
to the contactor phase (14) comes out of the casing through the end of the cover (10),
and the flexible cable (8) comes out of the casing through its opposite end, guaranteeing
that the connection will be made in the opposite phases of the auxiliary contact block
(16).
8. Resistance module for contactors according to the foregoing claims, wherein the housing
has a narrowing (36) that enables the contactor (14) to be connected to the network.
9. Resistance module for contactors according to Claim 1, wherein the housing has means
for retaining a crosspiece (27) of sufficient length to couple the different modules
connected between each phase of the contactor (14) and of the auxiliary contact block
(16), whereby a compact module block is obtained.
10. Resistance module for contactors according to Claim 9, wherein the means for retaining
the crosspiece (27) in the casing are formed by at least one groove (24), located
in the body (9) of each casing, in which a claw (28) of a tongue (29) situated in
the crosspiece fits and is retained, the tongues (29) being inserted in different
grooves (24), depending on the pitch existing between the phases of each size of contactor.