[0001] The present invention relates to a hand tool for deforming terminal leads of electric
cables and a connection block for electrical conductors preferably provided with said
terminal leads, that includes a socket to be removably fitted on a support member,
either alone or forming a connection strip by parallelly assembling several connection
blocks, a first port for an input conductor and a second port for a output conductor.
The connection block is optionally provided with one of such tools.
BACKGROUND ART
[0002] The use of terminal or end leads for covering the ends of electric cables to be connected
through connection blocks or strips is usual.
[0003] Normally said terminal leads have a front conductive portion for the wire cables
and a rear insulating portion for the cable sheath. Usually the diameter of the rear
portion is larger than that of the front portion.
[0004] Terminal leads have generally a cylindrical configuration and a cross-section according
to that of the cable to be connected. However, terminals in connection strips or blocks
have different cross-sections, for fitting or inserting the terminal leads, such as
square, rectangular, with curve and straight surfaces, etc., the cross-section in
the port of terminal leads being usually different from the circular cross-section
in the existing terminal leads, which notably hinders the insertion of said terminal
leads into the port of the connection blocks, with the operator often being forced
to use pliers for pressing and deforming the terminal leads in order to provide them
with such a form that they can be inserted into the connection block, with the involved
difficulties and defects in the result.
[0005] In addition, since generally the conductive front portion of the terminal lead has
thinner walls, so that they are better adapted to the cable wires and the electrical
contact of the cable and the terminal lead is facilitated, it is common for the operator
to cause an excessive deformation of the terminal lead which prevents the conductor
from being inserted into the terminal.
[0006] These connection blocks are used for making low-voltage electrical panels and usually
they are arranged side by side, forming connection strips or boards which are ready
to receive the cables to be connected without the installer having to handle the inner
installation in the panel. These connection blocks comprise an insulator body provided
with a socket that is removably fitted on a support member in the electrical panel.
[0007] The connection blocks usually include two connection terminals, for the input and
output cables or conductors respectively, and a conductor bridge between the terminals.
Normally, one of the terminals is intended for connection of a input conductor from
the panel, that connects with the inner installation made in a factory or workshop,
and the other terminal is intended for connection of an output conductor for the outer
installation, that is carried out by the installer in the place where the electrical
panel is to be installed.
[0008] The input and output conductor leads are generally provided with terminal or end
leads for preventing the cable wires from being messy or scattered.
[0009] The wiring of the inner installation is well defined and controlled, since it is
made at the workshop. However, wiring in the outer installation depends on the requirements
and circumstances of each application. For this reason, the connection block must
be designed for a predictable maximum use capacity, which is related to the cross-section
of the larger cable to be connected.
[0010] For several reasons, it is relatively frequent for the connection block input conductor
to have a cross-section that is smaller than that of the block output conductor, and
this forces the use of connection blocks with one of the terminals being over sized
with respect to the input conductor.
SUMMARY OF THE INVENTION
[0011] One object of the present invention is to provide a conductor connection system for
electrical panels that simplifies the operator's labor and improves the connection
features.
[0012] According to a first aspect of the invention, a hand tool for deforming terminal
leads of electrical cables includes a hole which inlet cross-section is greater than
that of the terminal lead to be deformed, for loosely inserting the front portion
of said terminal lead in the axial direction, and which walls are, at least in one
length, converging into the inside thereof and form the outer shape of the terminal
lead when being manually pushed into the hole.
[0013] Preferably, the walls of the hole are, at least in one length, gradually converging
into the inside thereof, that is, said walls are progressively converging and do not
have any sudden narrowings. The terminal lead is thus progressively deforming along
the hole and the pushing force on the terminal lead into the hole can be adjusted
and reduced.
[0014] In one embodiment, at least in one length of the hole, at least one of the walls
of the hole is substantially parallel to the axial direction of the hole, while at
least another of the walls of the hole is converging into the inside thereof. Thus,
straight and converging wall lengths or sub-lengths can be alternated (parallel to
the axial direction of the hole).
[0015] One possibility is that the walls of the hole are, at least in one length, alternately
converging into the inside thereof, which allows for different embodiments: for example,
in each sub-length there may be provided a single converging wall (which is changed
in the next sub-length) or in successive sub-lengths there may be straight and converging
walls alternated two by two. In any event, it is achieved that the terminal lead is
not deformed by all sides simultaneously, but alternately or successively.
[0016] The configuration of the tool makes the deformation of the terminal lead to be regular
and the cross-section is decreasing in the front portion thereof, which facilitates
the electrical cable terminal lead to be easily inserted into a connection terminal
port.
[0017] The contour of the variable cross-section of the hole may comprise straight and curved
segments, or a combination thereof. Terminal leads can be thus obtained having a cross-section
that is suitable for the different existing connection terminals.
[0018] Preferably, the walls of the hole define, at least in one length, a substantially
frusto-pyramidal shaped gap. The frusto-pyramidal shape provides a rectangular or
square shaped decreasing section in the front portion of the terminal lead, which
is particularly suitable for most connection terminals.
[0019] In one embodiment, the cross-section of at least one length of the hole is substantially
constant. This length, if provided downstream the decreasing cross-section length,
allows inserting the entire front portion of the terminal lead into the hole without
the outer end thereof being squashed more than it should.
[0020] According to a second aspect of the invention, a connection block for electrical
conductors comprises a single tightening terminal for the inner and outer connector
ends, so that said first and second ports open, in an opposed and offset arrangement,
into said tightening terminal, which comprises a hold-down plate and a clamp, so that,
when the two conductors are connected, their ends are overlapping and blocked between
the hold-down plate and the clamp.
[0021] The use of one of the clamp and hold-down plate assemblies and the conductor bridge
between the terminals of the conventional connection blocks is thus avoided, with
the resulting material savings. In addition, direct contact is provided between the
input and output conductors, allowing current to flow therethrough without any intermediate
elements, which may be necessary to size or which may have overheating problems. The
offset arrangement of the two ports allows insertion of the end of one conductor into
the terminal does not block insertion of the end of another conductor. Of course these
operations are facilitated, and contact between the two conductors is improved, if
conductors are provided with terminal leads.
[0022] In one embodiment, the first port comprises a lug in the form of a harpoon or the
like preventing input conductor terminal lead, and therefore said input conductor,
from being released out of the first port.
[0023] In one embodiment, the connection block comprises a slot intersecting the first port,
and a removable tab that is inserted into the slot until being fitted into the first
port and it opposes the return movement of the input cable terminal lead outwards
the first port.
[0024] Advantageously, the tab end to be inserted into the first port is U-shaped, such
that, with the tab is inserted into the first port, the input cable is flanked by
the arms of the U.
[0025] In one embodiment, the arms of the U are converging, at least in one length, for
defining an inner narrowing, such that the input cable is better clamped by the tab.
[0026] Whether it is with the lugs or the tab, these means for fastening the input conductor
terminal lead in the first port allow the input conductor to be fastened to the connection
block, leaving both operator's hands free for comfortably carrying out the connection
of the output conductor in the second port.
[0027] Preferably, the terminal is of the indirect tightening type and it comprises a screw
that can be accessed from the outside of the connection block, so that the hold-down
plate is fixed in the connection block and the clamp and the screw cooperate for tightening
the ends of the input and output conductors against the hold-down plate, although
the terminal could be of the direct tightening type, so that the screw would act as
a hold-down plate and tightening would be done directly on the conductor ends. The
advantage of indirect tightening is that the conductors or their terminal leads are
not damaged by screw turning, since tightening thereon is carried out by the fixed
hold-down plate.
[0028] Advantageously, the connection block is provided with at least one input conductor
segment that is fastened to the first port. The manufacturer of the electrical panel
can be thus supplied with the input cable already coupled to the connection block.
The input conductor terminal lead may be provided with a ribbing, made by pressure,
for increasing friction with the input cable end being covered by this, so that said
ribbing prevents the conductor from leaving out the terminal lead before the connection
terminal is pressed by this. The same ribbing serves for rubbing the output conductor
terminal lead when the two terminal leads are tightened in the connection terminal.
Preferably, the connection block comprises a hole which inlet cross-section is larger
than that of a terminal lead to be deformed, for loosely inserting the front portion
of said terminal lead in the axial direction, and which walls define a substantially
frusto pyramidal-shaped gap. Said gap has the features and advantages of the hand
tool described for deforming electric cable terminal leads.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] One embodiment of the invention will be described below by way of a nonlimiting example
with reference to the accompanying drawings, in which:
Fig. 1 is a top plan view a tool for deforming terminal leads;
Fig. 2 is an elevational sectional view of the tool in Fig. 1 taken along line A-A';
Fig. 3 is an elevational view of a terminal lead when being inserted into and deformed
in a hole of the tool;
Fig. 4 is a front view of a deformed terminal lead;
Fig. 5 is a side view of a terminal lead once deformed and inserted into a terminal
a block in a connection block or strip;
Fig. 6 is a perspective view of a tool for deforming terminal leads having a similar
configuration to that of the covers or spacers attached to the connection blocks or
strips;
Fig. 7 is a side sectional view of a connection block with two conductors fitted in
a terminal for being tightened;
Fig. 8 is a view similar to that of Fig. 7 but with no conductors;
Fig. 9 is a sectional front view taken along line B-B' in Fig. 8;
Fig. 10 is a top plan view of the block in Figure 8;
Fig. 11 is a view similar to that of Fig. 8 but corresponding to a further embodiment
and
Fig. 12 is a rear view of the embodiment in Fig. 11.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0030] Figs. 1 to 6 relates to a hand tool for deforming electric cable terminal leads,
and Figs. 7 to 12 relate to a connection block for electric cables provided with terminal
leads containing one of such tools, although if the cables are not provided with terminal
leads, they would be referred to as conductor ends instead.
[0031] A tool for deforming terminal leads according to the invention comprises a body or
matrix 1 provided with a hole 2 having a port 21 for insertion of the terminal lead
31 to be deformed, and which inner walls 22 are converging toward the bottom or the
opposite end of the port 21. The terminal lead 31 includes a front portion 33 (receiving
the bared end of a cable 3) and an enlarged rear portion 32 (for covering the cable
sheath).
[0032] In the figures, the inner walls 22 define a gap with a general frusto pyramidal configuration
having a square cross-section, although such cross-section may take on any shape according
to the ports in the existing connection blocks.
[0033] Neither is it necessary for all he walls 22 in the hole 2 to be converging simultaneously
into the inside thereof, but straight walls (parallel to the hole axial direction)
and converging walls can be combined in different lengths.
[0034] Once the terminal lead 31 has been positioned onto a conveniently peeled off end
of an electrical cable 3, said terminal lead is inserted into the hole 2 of the tool
and it is pushed axially for obtaining a radial deformation in the front portion of
the terminal lead, so that a configuration similar to that in the gap defined by the
inner walls 22 in the hole 2 can be taken on. Converging sides 33 to the front end
of the terminal lead 31 are formed in the front portion of the terminal lead.
[0035] By virtue of the obtained decreasing cross-section, this deformation of the terminal
lead allows it to be comfortably inserted into the corresponding port of a connection
block, as shown in Fig. 5, for subsequently tightening and fixing of the cable 3 in
its terminal 3.
[0036] The tool body or matrix may take on different geometric shapes, such as for example
those of the connection blocks (Fig. 5), end stops, covers or insulating partitions
that are usually attached to the connection blocks or strips, etc., as shown in Fig.
6.
[0037] Of course the tool body can take on further configurations, such as that of a screwdriver
handgrip or any other tool used normally in assembling electrical installations, or
it may be merely formed with a block suitable for providing comfortable grip and transport.
[0038] It can be also provided that the tool body comprises several holes having different
cross-sections and sizes to enable deformation of terminal leads suitable for different
diameters of electric cables.
[0039] Now referring to Figs. 7 to 12, a connection block comprises a body of insulating
material having a socket 11 at its rear portion for being fastened to a standard section
member, and it is provided with respective ports at their sides for conductors to
be connected, a first port 12 for an input conductor 5 and a second port 13 for an
output conductor 3. Said ports are in an opposite and offset arrangement and extending
into a housing 14 where a terminal 4 for connecting and fastening both conductors
is received.
[0040] The body of the connection block comprises, in the front portion thereof, a hole
15 for gaining access to a screw 41 for tightening the terminal 4, which also includes
a clamp 43 and a hold-down plate 42 embedded into the connection block just in front
of the position of the terminal lead (or end) 51 of the input conductor 5 once inserted
into its port 12. Once placed in position, said terminal lead 51 is fastened between
the clamp 43 and the hold-down plate 42 under pressure by the screw 41, acting on
the hold-down plate 42. In this case, tightening of the terminal 4 is of the indirect
type, but if the hold-down plate is omitted, tightening would be of the direct type
on the part of the screw 41.
[0041] The connection block comprises, at its front portion and that adjacent to the hole
15, a shaping hole or gap 2, by way of a tool for deforming terminal leads, having
a generally frusto pyramidal shape for the shaping of the terminal lead 31 (where
applicable) in the output conductor 3.
[0042] The first port 12 for the input cable extends inwardly into a housing 17 having,
in its front contour, lugs 18 in the form of a harpoon or the like for blocking the
terminal lead 51 of the input conductor 5, as well as the conductor itself inside
the port 12.
[0043] Alternatively (Figs. 11 and 12), the connection block comprises a slot intersecting
the first port 12, and a removable tab 19 that is inserted into the slot until being
fitted into the first port 12 and it opposes the return movement of the terminal lead
51 of the input cable 5 outwards the first port 12.
[0044] The end of the tab 19 that is inserted into the first port 12 is U-shaped such that,
with the tab 19 being inserted into the first port 12, the input conductor 5 is flanked
by the arms of the U. Said arms are converging near their ends and define a narrowing
in the gap of the U in that area, such that the input conductor is covered and better
fastened. The cross-section of the inner portion of the U is according to the input
conductor 5, usually circular, for being better adapted thereto.
[0045] The connection block is ready to receive an input conductor 5 with a terminal lead
51 having a square or rectangular cross-section provided with a deformation that prevents
insertion of the outer conductor 3 from being interfered in the housing area 14 of
the terminal 4, said terminal lead 51 being positioned at the front portion of said
housing 14.
[0046] The second port 13, for the output conductor 3, is offset toward the rear portion
of the connection block, such that the front end of the terminal lead 31 of the output
conductor 3 is arranged in the rear portion of the housing 14 of the terminal 4, and
it is in immediate contact with the adjacent end of the terminal lead 51 of the input
conductor 5.
[0047] The clamp or moving frame 43 comprises a thread that is coupled to the screw 41,
so that when tightening the screw, the terminal leads (or the ends) of the two conductors
are pressed by said clamp against the hold-down plate 42 (or directly against the
screw 41, in its case).
[0048] Although in the present specification only particular embodiments of the invention
have been depicted and described, those skilled in the art will be able to made modifications
and replace technical features with equivalent ones, depending on the requirements
in each case, without departing from the scope defined by the appended claims.
[0049] It is, for example, apparent that shapes or materials can be varied to a certain
extent while meeting the operating requirements of the invention.
1. Hand tool for deforming terminal leads of electric cables, characterized in that it comprises a hole (2) which inlet has a cross-section that is larger than that
of a terminal lead to be deformed, for loosely inserting the front portion of said
terminal lead in the axial direction, and which walls are, at least in one length,
converging into the inside thereof and determine the outer shape of the terminal lead
when being manually pushed into the hole (2).
2. Hand tool as claimed in claim 1, wherein the walls of the hole (2) are, at least in
one length, gradually converging into the inside thereof.
3. Hand tool as claimed in claim 1 or 2 wherein, at least in one length of the hole (2),
at least one of the walls of the hole is substantially parallel to the axial direction
of the hole, while at least another of the walls of the hole is converging into the
inside thereof.
4. Hand tool as claimed in claim 3, wherein the walls of the hole (2) are, at least in
one length, alternately converging into the inside thereof.
5. Hand tool as claimed in any of the preceding claims, wherein the contour of the variable
cross-section of the hole (2) comprises curved segments
6. Hand tool as claimed in any of the preceding claims, wherein the contour of the variable
cross-section of the hole (2) comprises straight segments
7. Hand tool as claimed in any of the preceding claims, wherein the walls (22) of the
hole (2) define, at least in one length, a generally frusto pyramidal shaped gap.
8. Hand tool as claimed in any of the preceding claims, wherein the cross-section of
at least one length of the hole (2) is substantially constant.
9. Connection block for electrical conductors preferably provided with terminal leads,
which comprises a socket (11) for being removably fitted on a support member, either
alone or forming a connection strip by parallelly assembling several connection blocks,
a first port (12) for an input conductor and a second port (13) for an output conductor,
characterized in that it further comprises a single tightening terminal (4) for the ends of said input
and output conductors, so that said first (12) and second (13) ports open, in an opposed
and offset arrangement, into said tightening terminal (4), which includes a hold-down
plate (42) and a clamp (43), such that, when connecting the two conductors, their
ends are overlapping and blocked between the hold-down plate (42) and the clamp (43).
10. Connection block as claimed in claim 9, wherein the first port (12) comprises lugs
(18) in the form of a harpoon or the like preventing the terminal lead of the input
conductor, and therefore said input conductor, from being released out of the first
port (12).
11. Connection block as claimed in claim 9, wherein it comprises a slot intersecting the
first port (12), and a removable tab (19) that is inserted into the slot until being
fitted into the first port (12) and it opposes the return movement of the input cable
terminal lead outwards the first port (12).
12. Connection block as claimed in claim 11, wherein the end of the tab (19) that is inserted
into the first port (12) is U-shaped, so that, with the tab (19) being inserted into
the first port (12), the input conductor is flanked by the arms of the U.
13. Connection block as claimed in claim 12, wherein, at least in one length, the arms
of the U are converging such that an inner narrowing is defined.
14. Connection block as claimed in any of the claims 9 to 13, wherein the terminal (4)
is of the indirect tightening and it includes a screw (41) that can be accessed from
the outside of the connection block, so that the hold-down plate (42) is fixed to
the connection block and the clamp (43) and the screw (41) cooperate to tighten the
ends of the input and output conductors against the hold-down plate (42).
15. Connection block as claimed in any of the claims 9 to 13, wherein the terminal (4)
is of the direct tightening, so that the screw (41, 42) acts as a hold-down plate
and tightening is carried out directly on the conductor ends.
16. Connection block as claimed in any of the claims 10 to 15, wherein it includes at
least one segment of the input conductor that is fastened to the first port (12).
17. Connection block as claimed in any of the claims 9 to 15, wherein it comprises a hole
(16) which inlet has a cross-section that is larger than that of a terminal lead to
be deformed, for loosely inserting the front portion of said terminal lead in the
axial direction, and which walls define a generally frusto pyramidal shaped gap.