[0001] The present invention relates to a fuse clip assembly for use primarily but not exclusively
in a vehicle electrical system fuse box to a bus bar and a fuse clip for use in such
an assembly, and to a fuse box utilising such an assembly.
[0002] In our British Patent No. 2123626 there is disclosed a fuse clip unit wherein a bus
bar is integral with, and electrically interconnects, a plurality of spaced parallel
fuse clips, the unit being formed from sheet brass which is stamped and folded to
define the fuse clips, the bus bar and means for gripping and making electrical connection
to one or more electrical connecting leads.
[0003] The fuse clip unit of Patent 2123626 is suitable for many applications but presents
problems where a close positioning of adjacent parallel clips is required. The problem
results from the fact that the clips are integrally formed by stamping and folding
sheet material, the developed width (the unfolded width) of each clip determining
the minimum spacing between clips along the bus bar. For example, where the developed
(unfolded) width of the clips is 15mm and the clips, in their developed form, are
symmetrical about centre lines at right angles to the length of the integral bus bar,
then the minimum spacing of clips (centre line to centre line) is 15mm.
[0004] It has previously been proposed to overcome this difficulty by producing the unit
with minimum spacing and then folding or otherwise deforming the bus bar between adjacent
clips to reduce the spacing between clips. Such a solution is in itself disadvantageous
in that additional manufacturing steps are necessary to shorten the bus bar between
clips, the shortening operation risks damage to the unit so increasing the failure
rate and may, through mechanical working of the bus bar, affect its electrical properties,
and the shortened bus bar takes up more space in the fuse box in the direction in
which the bus bar is deformed and this dimension must be accommodated in the fuse
box design. A further disadvantage of the unitary construction is that the bus bar
and the clips are formed from the same material whereas ideally the bus bar is formed
from a material of high conductivity whereas the material of the clip should exhibit
good resilience and in the unitary construction therefore the material is a compromise
between the two requirements.
[0005] It is an object of the present invention to provide a fuse clip assembly wherein
the aforementioned problems are mitigated or avoided.
[0006] In accordance with the present invention there is provided a fuse clip assembly comprising,
an elongate bus bar having integral therewith a plurality of juxtaposed parallel blade
terminals extending transverse to the length of the bus bar, and,
a plurality of fuse clips, each fuse clip having a fuse engaging portion and an integral
flat, socket terminal portion, each fuse clip being carried by and electrically connected
to the bus bar by engagement of a respective blade terminal of the bus bar in the
socket terminal portion of the clip.
[0007] Preferably the bus bar includes at least one integral connector means whereby an
electrical connecting lead can be electrically connected to the bus bar.
[0008] Desirably the bus bar is formed from copper sheet or strip and the fuse clips are
formed from brass sheet or strip.
[0009] The invention further resides in a bus bar for use in a fuse clip assembly, the bus
bar comprising an elongate conductive strip having integral blade terminals projecting
parallel to one another transverse to the length of the strip.
[0010] The invention still further resides in a fuse clip for use in a fuse clip assembly,
the clip comprising a fuse engaging portion, and an integral flat socket terminal
portion for receiving a blade terminal.
[0011] The invention yet further resides in a fuse box comprising an electrically insulating
housing, a fuse clip assembly as specified above disposed in the housing with each
fuse clip thereof disposed adjacent a further fuse connector so that each clip defines
with a respective connector a pair of elements for receiving respectively the terminal
regions of a fuse.
[0012] The present invention will now be further described, by way of example, with reference
to the accompanying drawings wherein,
Fig. 1 is a diagrammatic plan view illustrating the components of one embodiment of
a fuse clip assembly constructed according to the present invention;
Fig. 2 is a side elevational view of a fuse clip as shown in Fig. 1;
Fig. 3 is a view in the direction of arrow A in Fig. 2;
Fig. 4 is a diagrammatic perspective view, to an enlarged scale of the fuse clip of
Figs. 2 and 3; and
Fig. 5 is a diagrammatic representation of a fuse suitable for use with the assembly
of Fig. 1.
[0013] Referring to the accompanying drawings, the fuse clip assembly illustrated includes
a bus bar 11 and a plurality of fuse clips 12.
[0014] The bus bar 11 is stamped from tinned copper strip material and includes an elongate
connecting strip 13 having integral therewith a plurality of juxtaposed parallel blade
terminals 14. The blade terminals 14 are coplanar with the strip 13 and protrude from
one edge of the strip at right angles to the length of the strip. The blade terminals
are equidistantly spaced along the edge of the strip and the free-end region of each
blade terminal is chamfered. Moreover, each blade terminal is pierced, adjacent its
free end, to define an aperture 15 therein.
[0015] At predetermined points along the length of the strip 13, conveniently aligned with
the root of alternate blade terminals 14, the strip 13 defines two pairs of integral
deformable tags 16, 17. The tags 17 are at the edge of the strip 13 opposite that
carrying the blade terminals 14, and the tags 16 are formed within the body of the
strip, the reference numerals 18 identifying rectangular apertures produced by bending
the tags 16 out of the plane of the strip. At the right hand end of Fig. 1 the tags
16 and 17 are shown deformed around an electrical connecting lead 19, the tags 17
being deformed around the insulating sheath of the lead 19 and the tags 16 being deformed
around a bared portion of the core of the lead 19. Thus the two pairs of tags provide
a physical connection of the lead to the bus bar, and the tags 16 provide an electrical
connection between the core of the lead 19 and the bus bar 11. The remaining pairs
of tags 16, 17 along the length of the bus bar are shown bent over to lie in facial
contact with portions of the bus bar lying between the roots of the tags. During manufacture
of the bus bar, as the bus bar is stamped from the strip of copper, the strip material
is cut to define the tags, and at the same time the tags are bent upwardly to lie
generally at right angles to the plane of the strip. Clearly if they were left in
this position during use of the bus bar then they would materially increase the space
needed to house the bus bar. For this reason during use of the bus bar those tags
which are not associated with a lead are bent to lie flat, either by being pressed
back to lie coplanar with the strip 13 of the bus bar, or, as shown in Fig. 1, by
being folded over as if they were making connection to a lead.
[0016] Each fuse clip 12 is formed from a sheet or strip of tinned brass. The use of copper
for the bus bar 11 is preferred to the use of brass primarily owing to its better
conductivity. The bus bar does not require resilience, and so the lack of resilience
of copper is of no consequence. However, the clips 12 do require resilience and thus
the use of brass is preferred to copper.
[0017] Each fuse clip 12 has two distinct, but integral portions, a fuse engaging portion
21 and a flat socket terminal portion 22. The flat socket terminal portion 22 of each
clip comprises a generally flat base 23 and a pair of inwardly rolled side portions
24. The shape of the portion 22 conforms to that of the well recognised female "LUCAR"
terminal designed to receive, grip and make electrical connection to a flat blade
terminal.
[0018] The fuse engaging portion 21 of each fuse clip 12 is integral with the socket terminal
portion 22 and comprises a pair of elongate, transversely spaced, resilient arms 25
extending outwardly in the direction of the length of the terminal portion 22. Part-way
along their length the arms 25 are bent to a U-shape so that the end regions of the
arms 25 lie close together, or even in facial contact, and extend back towards the
socket portion 22 between their respective root portions. It will be recognised therefore
that the closely adjacent portions 25
a of the arms 25 define a pair of substantially planar regions urged, by the inherent
resilience of the arms 25, towards facial contact with one another. A flat blade-like
terminal 27 of a fuse 26 (Fig. 5) introduced between the portions 25
a will be gripped thereby, and there will be established a good electrical connection
over a large surface area.
[0019] The fuse clip assembly is completed by engaging the desired number of fuse clips
12 with respective blade terminals 14 of the bus bar 11, the bus bar 11 first having
been cut to an appropriate length determined by the number of fuse clips required.
Each blade terminal 14 is received in the flat socket terminal portion 22 of the respective
fuse clip 12, and in order to resist withdrawal of a fuse clip 12 from the bus bar
11 the base 23 of the terminal portion 22 of each fuse clip 12 is formed with a locking
projection which engages within the aperture 15 of the mating blade 14 when the fuse
clip is correctly engaged with the bus bar. In the event that it is necessary at some
stage to remove fuse clips from the bus bar then the projection on the base 23 may
be a rounded projection which provides a good latching of the terminal portion 22
on the blade terminal 14, but does not prevent deliberate, subsequent withdrawal,
or alternatively where the fuse clips are to be substantially permanently attached
to the bus bar then the projection on the base 23 of each fuse clip may be a half-sheared
formation which, in effect, locks into position in the respective aperture 15.
[0020] One or more electrical connecting leads 19 will be attached, as described above,
to the bus bar 11 at some convenient point in the assembly, and this may be before,
or after, engagement of the fuse clips with the bus bar. It will be recognised that
with the type of construction described above the fuse clips and the bus bar can be
formed from different, and individually suitable materials, and moreover, the minimum
spacing between adjacent fuse clips of the assembly is governed primarily by the thickness
of the material used to form the fuse clips. The developed width (that is to say the
unfolded width) of the fuse clips is irrelevant in determining the minimum spacing
since the clips are attached to the bus bar as individual items. The tags 17 and 18
can be spaced as desired along the length of the bus bar, and thus their developed
width is also irrelevant. The blade terminals 14 do not involve folding of material
and thus they can be positioned as close as desired along the length of the strip.
The only parameter of importance therefore is the thickness of the material of the
clips 12, since the spacing between adjacent blade terminals 14 must, at minimum,
be twice this thickness to permit fuse clips to be engaged simultaneously with adjacent
blade terminals.
[0021] A fuse clip assembly as described above is utilised in the fuse box which comprises
a moulded synthetic resin housing having means whereby the fuse clip assembly can
be mounted therein with the fuse engaging portions 21 of the clips extending towards
an open face of the housing. The clips 12 will of course, by virtue of the bus bar
11, be arranged in a linear row, and within the fuse box housing there is a parallel
linear row of fuse connectors. The fuse connectors have fuse engaging portions identical
in form to the fuse engaging portions 21 of the clips 12, but do not necessarily incorporate
respective socket terminal portions 22. For example the fuse connectors may be secured
to a printed circuit board forming the base of the fuse box, the printed circuit board
carrying conductive tracks electrically connected to respective fuse connectors of
the board. Each fuse connector will be positioned adjacent a respective clip 12, and
a fuse, for example of the kind illustrated in Fig. 5, will have one of its terminal
blades 27 engaged in the portion 21 of a clip and the other of its terminal blades
engaged in the respective adjacent fuse connector so that the fuse electrically interconnects
the lead 19, attached to the fuse clip assembly, with the printed circuit board conductive
track which is associated with the respective fuse connector.
[0022] The invention is not restricted to the specific fuse engaging portion 21 described
above. A number of different fuse configurations are presently available, and the
nature of the fuse engaging portion 21 of each clip 12 will be determined by the nature
of the fuse with which the clip is to be utilised. For example the fuse clips may
be shaped to accommodate the cylindrical end-caps of cartridge type fuses.
1. A fuse clip assembly characterised by an elongate bus bar (11) having integral
therewith a plurality of juxtaposed parallel blade terminals (14) extending transverse
to the length of the bus bar (11), and a plurality of fuse clips (12), each fuse clip
(12) having a fuse engaging portion (21) and an integral socket terminal portion (22),
such fuse clip (12) being carried by and electrically connected to the bus bar (11)
by engagement of a respective blade terminal (14) of the bus bar (11) in the socket
terminal portion (22) of the clip (12).
2. A fuse clip assembly as claimed in claim 1, wherein the bus bar (11) includes at
least one integral connector means (16) whereby an electrical connecting lead (19)
can be electrically connected to the bus bar (11).
3. A fuse clip assembly as claimed in claim 1 or claim 2, wherein the bus bar (11)
includes at least one integral tag (17) for use in solely physically attaching an
electrically connecting lead (19) to the bus bar (11).
4. A fuse clip assembly as claimed in any one of claims 1 to 3, wherein the bus bar
(11) is made of copper sheet or strip and the fuse clips are formed from brass sheet
or strip.
5. A fuse clip assembly as claimed in any one of claims 1 to 4, wherein each blade
terminal (14) and fuse clip (12) have interengaging means (15) for retaining the fuse
clip (12) on the blade terminal (14).
6. A fuse clip assembly as claimed in claim 5, wherein the interengaging means (15)
is formed by an aperture (15) in the blade terminal (14) and a protuberance on the
fuse clip (12), which protuberance engages on the aperture (15) when the fuse clip
(12) is slid into the blade terminal (14).
7. A fuse clip assembly as claimed in any one of claims 1 to 6, wherein the socket
terminal portion (22) of each fuse clip (12) comprises a generally flat base (23)
and a pair of inwardly rolled side portions (24).
8. A fuse clip assembly as claimed in any one of claims 1 to 7, wherein the fuse engaging
portion (21) of each fuse clip (12) comprises a pair of elongate, transversely spaced,
resilient arms (25), the arms (25) extending from the socket terminal portion (22)
and being each bent to a U-shape so that the end regions of the arms (25) lie close
together or even in contact, and extend back towards the socket portion (22).
9. A fuse clip assembly as claimed in any one of claims 1 to 8, when installed in
a fuse box, with each fuse clip (12) disposed adjacent to a further fuse connector
so that each clip (12) defines with a respective connector a pair of elements for
respectively receiving the terminal regions of a fuse (26).
10. A bus bar for use in a fuse clip assembly, comprising an elongate electrically
conductive strip (13) having juxtaposed integral blade terminals (14) projecting parallel
to one another transverse to the length of the strip (13).
11. A bus bar as claimed in claim 10, wherein at least one integral connector means
(16) is included whereby an electrical connecting lead (19) can be electrically connected
to the bus bar (11).
12. A bus bar as claimed in claim 10 or claim 11, wherein the bus bar (11) includes
at least one integral tag (17) for use in solely physically attaching an electrically
connecting lead (19) to the bus bar (11).
13. A fuse clip for use in a fuse clip assembly, comprising a fuse engaging portion
(21) and an integral socket terminal portion (22), the socket terminal portion (22)
being suitable for electrically and physically attaching the fuse clip (12) to a blade
terminal (14).
14. A fuse clip as claimed in claim 13, wherein the socket terminal portion (22) comprises
a generally flat base (23) and a pair of inwardly rolled side portions (24).
15. A fuse clip as claimed in claim 12 or claim 13, wherein the fuse engaging portion
(21) comprises a pair of elongate, transversely spaced, resilient arms (25), the arms
(25) extending from the socket terminal portion (22) and being each bent to a U-shape
so that the end region of the arms (25) lie close together or even in contact, and
extend back towards the socket portion (22).