APPARATUS FOR MOULDING BATTERY COMPONENTS
Field of the Invention
The present invention relates to an apparatus for moulding battery
components and a method of moulding battery components.
Background of the Invention
The term "battery" is used herein to include accumulators. In a
conventional lead-acid battery it is customary to connect together the plates of
each stack by means of a lead strap or post which is fixed to aligned lugs or tabs
on the plates.
In the manufacture of batteries, particularly for example lead acid
batteries, it is known to cast battery components. Components such as straps
and other formations can also be simultaneously cast onto the lugs of battery
plates so as to, for example, form a connection between a set of plates within a
cell of the battery. Such straps are generally cast by filling a mould cavity with
lead and dipping lugs into the cavity prior to the cooling of the lead. Typically,
the mould cavities are filled by allowing lead to flow into channels at the sides of
the cavities and spill over a weir into the mould.
An example of a typical casting apparatus is shown in the Applicant's
earlier application W094/16466 in which the apparatus includes a mould having
a set of post or strap mould cavities, a molten metal feed duct adjacent thereto,
a weir between the feed duct and the cavities, means for supplying molten lead
to the duct, and hence the cavities, a pump and at least a pair of substantially
parallel feed passages extending below the duct and connected to the duct.
It is important that the flow of lead into all of the mould cavities is carefully
controlled during the casting of components. Ideally the flow of molten lead
should be balanced or controlled along the length of the mould trough so that all
the cavities fill at the same time and at the same rate. Such balancing of the
flow is difficult to achieve with existing apparatuses and may for example be
effected by manufacturing tolerances and operating conditions in the mould
and/or supply.
A further complication arises, when left and right sets of mould cavities
are provided, each having an adjacent feed duct and associated feed passages.
In this case it desirable that the flow of molten lead is balanced between the left
and right sides.
The applicant has previously attempted to address the problem of left and
right side flow control (or left and right flow balancing) by providing a throttle bolt
in either the left or the right feed passage at the pump end. The throttle bolt can
be adjusted to alter the flow rate of the molten metal through the passage to
ensure that the left and right mould cavities are filled at an even rate.
A further possible solution to the problem of balancing the flow of molten
metal is to provide multiple supply pumps and inlets, and to regulate each
individually. However, this increases the complexity and cost of the apparatus.
Embodiments of the invention seek to provide an apparatus which may
provide improved delivery of lead to the mould cavities.
Summary of Invention
According to a first aspect of the present invention there is provided an
apparatus for moulding battery components including:
a mould block having a plurality of mould cavities;
a molten metal feed trough adjacent to the mould block and
extending in a generally longitudinal direction along the mould block;
a plurality of weirs between the feed trough and each of the
cavities; and
a supply for providing molten metal to the trough;
wherein the feed trough is provided with at least one volume
adjustment mechanism, which is operable to alter the volume of the feed
trough.
The applicants have found that such an arrangement provides a simple
and convenient means of balancing the flow through the feed trough and over
the weirs into the cavities. As the troughs are at the upper surface of the mould
(and are generally open) the adjustment mechanism may be easily accessed
and its position viewed by the user (in contrast to throttle bolt arrangements
which act internally within the mould). The feed trough may include a first end; a
second end and a central portion. The plurality of weirs may be provided along
the central portion.
Typically two volume adjustment mechanisms may be provided, one at
each end of the feed trough. The volume adjustment mechanisms may be
independently adjustable. As such the apparatus may allow control/adjustment
of the flow along the length of the trough.
The, or each, volume adjustment mechanism may be arranged to be
adjusted between a plurality of indexed positions. For example the adjustment
mechanism may include an element which can be secured in at least two
discrete positions within the feed trough. The index positions may provide
physical alignment. Additionally, the index may provide a convenient visual
representation of the selected position for the end user.
The, or each, volume adjustment mechanism may be arranged to provide
an adjustable position end wall of the trough in use. The end wall may effectively
adjust the length of the trough in use.
The, or each, volume adjustment mechanism may comprise an element
which is arranged to be received within the feed trough. The element may, for
example, have a lower profile which is shaped and configured to match the
shape and configuration of the trough.
The, or each, element may be arranged to be longitudinally moveable
within the feed trough. For example the element may be slideable within the feed
trough. Alternatively, the element may be positionable in a series of longitudinal
positions within the trough.
The, or each, volume adjustment mechanism may further comprise a
locking member arranged to secure the element in position.
The, or each, element may be provided with a plurality of features to be
engaged by the locking member. The features may for example be a plurality of
notches or recesses (into which the locking member may for example be
received). The notches or recesses may be defined by castellations along the
upper surface of the element.
The supply may comprise a feed passage extending below the feed
trough. The supply may further comprise a plurality of substantially vertically
extending passages connecting the feed passage to the feed trough. The supply
may further comprise a supply pump inlet in fluid communication with the feed
passage, for connection to a pump supplying molten metal.
The feed passage may comprise an inner feed passage extending below
the feed trough and connected to the feed trough. The feed passages may also
comprise an outer feed passage extending substantially parallel to the inner feed
passage, the supply pump inlet being in fluid communication with the outer feed
passage. At least one connection passage may be provided leading from the
outer feed passage to the inner feed passage.
Typically, the apparatus may extend longitudinally and the supply pump is
provided at one end of the apparatus.
The apparatus may include a second mould block, provided adjacent and
parallel to the first mould block, the second mould block having a plurality of
mould cavities.
A second molten metal feed trough may be provided adjacent to the
second mould block and extending along the length of the mould block. A
plurality of weirs may extend between the second feed trough and each of the
cavities. A second supply may be arranged for providing molten metal to the
second trough. The second feed trough may be provided with at least one
volume adjustment mechanism, which is operable to alter the volume of the
second feed trough.
The second supply may comprise a second feed passage extending
below the second feed trough. The second supply may further comprise a
plurality of substantially vertically extending passages connecting the second
feed passage to the second feed trough. The second supply may further
comprise a supply pump inlet. The first and second supply may be connected to
a common inlet.
The second feed trough may include volume adjustment mechanism
having any of the features described above.
Two further volume adjustment mechanisms may be provided, one at
each end of the second feed trough The volume adjustment mechanisms may
be independently adjustable.
According to a further aspect of the present invention, there is provided a
method of moulding battery components including
providing an apparatus for moulding battery components including:
a mould block having a plurality of mould cavities; a molten metal feed
trough adjacent to the mould block and extending along the length of the
mould block; a plurality of weirs between the feed trough and each of the
cavities;
providing a supply arrangement for supplying molten metal into the
feed trough;
adjusting the volume adjustment mechanism to alter the volume of
the feed trough so that the molten metal flows over the weirs into the
plurality of mould cavities simultaneously.
The step of adjusting the volume may include moving volume adjustment
mechanisms at one or both ends of the feed trough. The volume adjustment
mechanisms may be adjusted to order to balance the flow of molten metal into
the cavities along the length of the mould block.
The step of adjusting the volume may include moving volume adjustment
mechanisms at one or both ends of the left and right feed troughs in order to
balance the flow of molten metal into the cavities along the length of the both the
left and the right mould blocks.
According to a further aspect of the invention, there is provided an
apparatus for moulding battery components substantially as described herein.
According to a further aspect of the invention, there is provided a method
of moulding battery components substantially as described herein.
Whilst the invention has been described above, it extends to any
inventive combination of features set out above or in the following description or
drawings.
Brief Description of the Drawings
Specific embodiments of the invention will now be described in detail by
way of example only and with reference to the accompanying drawings in which:
Figure 1 is a schematic representation of a plan view of an
apparatus according to an embodiment of the invention;
Figure 2 is a schematic representation of Figure 1 with cut-away
sections showing internal components of the apparatus;
Figure 3 is a cross-sectional view of the apparatus of Figure 1,
taken through line A;
Figure 4 is an expanded schematic representation of the
highlighted area of Figure 3 ;
Figure 5 is schematic representation of an adjustment mechanism
according to the embodiment of Figure 1; and
Figure 6 is a schematic representation of an adjustment element
for use in the embodiment of figure 1.
Description of an Embodiment
Figure 1 shows a plan view of an apparatus 1 for moulding battery
components according to an embodiment of the invention. The apparatus 1
includes a left (or first) mould block 100 and a right (or second) mould block 200.
In this embodiment the left mould block 100 is integrally formed with the right
mould block 200. However, the two mould blocks could also be formed
separately.
A left support block 120 is secured to the left side of the left mould block
100; and a right support block 220 is secured to the right side of the right mould
block 200.
Each mould block 100, 200 has a longitudinally extending form with
several mould cavities 110 , 210 provided along its length.
Left and right feed troughs 130, 230 extend longitudinally along the upper
surface of the left and right support blocks 120, 220. The left and right feed
troughs are positioned along the outer edge of the left and right mould blocks
100, 200. Each trough 130, 230 extends from a first end 132, 232 to a second
end 134, 234. As best seen in the cross-section of Figure 3 each trough 130,
230 has a radiused base 138, 238 and parallel spaced apart inner 135, 235 and
outer 136, 236 side walls.
The left and right support blocks 120, 220 are joined at one end by a
cross-member 10 , the support blocks 120, 220 and cross member 10 thereby
forming a u-shape when viewed from above. The cross-member 10 includes a
T-connector 20 having an inlet 22 and two outlets 24, 26. In use, the inlet 22 is
connected to a molten lead supply (not shown), which may include a pump
assembly, A left outer feed passage 140 provided in the left support block 120
is in fluid connection with the left outlet or branch 24 of the T-connection. A right
outer feed passage 240 provided in the right support block 220 is in fluid
connection with the right branch 26 of the T-connector 20. The outer feed
passages 140, 240 extend longitudinally in the support blocks along
substantially the length of the apparatus 1, as can be seen from Figure 2 .
As shown in Figure 3 , a left inner feed passage 142 is provided in the left
support block 120 substantially parallel to the left outer feed passage 140. The
left inner feed passage 142 extends longitudinally along the apparatus and is
provided below the left feed trough 130. Similarly a right inner feed passage 242
is provided in the right support block 220, extending substantially parallel to the
right outer feed passage 240 and below the right feed trough 230.
In the illustrated embodiment, the inner feed passages 142, 242 are
initially formed to have a fluid connection to the right branch 24 of the Tconnector,
and this connection is blocked with a plug 144, 244. The left inner
feed passage 142 and left outer feed passage 140 are fluidly connected at a mid
point 146 as shown in the central cut-away section of Figure 2 . A similar fluid
connection is provided between the right inner and outer feed passages 240,
242 at a mid-point 246.
The inner feed passages 142, 242 are connected to each respective feed
trough 130, 230 by means of a plurality of substantially vertically extending
passages 148, 248.
Along the feed troughs 130, 230 narrow supply channels 132, 232 extend
generally perpendicularly to the longitudinal direction from the inner side wall
135, 235 of the trough towards each mould cavity 110 , 2 10 . At the end of each
supply channel 132, 232, and in alignment with the respective mould cavities
110 , 2 10 , is a weir 133, 233. Figure 4 is an enlarged representation of a crosssectional
view of the area around one of the feed troughs 130. The feed trough
130 has an outer side wall 136 opposite the weir 133, and a base 138. At an
outer edge of the channel 132 is a lip or overhang 134 which extends partially
over the base of the supply channel.
The mould cavity 110 has a base 122, at a depth c below the weir 133.
The depth of the feed trough 130 is greater than the depth of the mould cavity
110 . Figure 4 also shows the molten metal M at a pre-fill height p in the trough
130, which is significantly below the level of the weir 133.
The left feed trough 130 is provided a first volume adjustment mechanism
160 at the end 132 of the trough 130 which is closest to the pump inlet 22; and a
second volume adjustment mechanism 162 at the other end 134 of the trough
130 (the end which is remote or distal from the pump inlet 22). Likewise, the
right feed trough 230 is also provided with first and second volume adjustment
mechanisms 260, 262 respectively positioned at the ends 232 and 234.
In the embodiment shown in the Figures, all of the volume adjustment
mechanisms have the same structure, which will be described with regard to
Figure 5 which shows an enlarged view of the second volume adjustment
mechanism 262 on the right feed trough 230 and Figure 6 which shows an
adjustment element 264 in isolation. However, it should be appreciated that all
the other volume adjustment mechanisms have this structure.
The volume adjustment mechanism 262 includes a first element 264
which is arranged to be received within the feed trough 230. The lower profile of
the element 264 is radiused and shaped and configured to match the profile of
the trough 230. When positioned within the trough 230 the first element 264 is
arranged to be slidable in a longitudinal direction S. A second element 270 is
provided as a locking element which is operable to lock or secure the first
element 264 in a desired position. As explained further below, when positioned
within the feed trough 230 the elements of the volume adjustment 160, 162, 260,
262 act to define an end wall of the trough 130, 230.
In the embodiment shown, the first element 264 is provided castellations
266 along its upper surface which define a series of notches or recesses 268.
The second element 270 is arranged to engage the notches or recesses 268 so
that the element 264 may be secured in a plurality of indexed positions within
the trough 230. Conveniently, the second element 270 is slidebly mounted in a
recess 272 in the upper surface of the right support block 220. In the
embodiment shown, the second element 270 is provided with a slot 273 though
which a bolt 274 is inserted and screwed into a corresponding threaded hole
(not shown) in the recess 272. The second element 270 has an inner end 276
which is configured to fit within the notches 268 on the first element 264. The
second element 270 slides perpendicularly to the first element 264. To position
and secure the volume adjustment mechanism 262, the first element 264 is slid
in the feed trough 230 towards or away from the pump inlet 22 to the desired
position. The second element 270 is then slid inwards until its inner end 276
engages with a notch 268 on the first element 264, and the bolt 274 is tightened
to hold the second element 270 in place, thereby locking the first element 264 in
position.
It will be appreciated that any other suitable mechanism could be used to
secure the first element in a desired position. For example a second slideable
element having an inner end with an engaging feature, and which is resiliently
biased inwards to engage corresponding engaging features on the first element.
Alternatively, a second element could be provided which is not slideable at all,
but which is in some other way moveable, for example being pivotable, between
a first position in which it locks and engages the first element and a second
position in which the first element is freely slideable. The second element could
also be removably, attached to the apparatus to engage and secure the first
element.
In order to increase the volume of the feed trough 130, 230 at the pump
inlet 22 end of apparatus, the first volume adjustment mechanism 160, 260 is
moved towards the pump inlet 22, thereby elongating the feed trough 130, 230.
To decrease the volume of the feed trough 130, 230 at the pump inlet 22 end of
apparatus, the first volume adjustment mechanism 160, 260 is moved away from
the pump inlet 22, thereby shortening the feed trough 130, 230.
In order to increase the volume of the feed trough 130, 230 at the end of
apparatus remote or distal from the pump inlet 22, the second volume
adjustment mechanism 162, 262 is moved away from the pump inlet 22, thereby
elongating the feed trough 130, 230. To decrease the volume of the feed trough
130, 230 at the end of apparatus remote or distal from the pump inlet 22, the
second volume adjustment mechanism 162, 262 is moved towards the pump
inlet 22, thereby shortening the feed trough 130, 230.
It will therefore be appreciated, that the volume adjustment mechanisms
160, 162, 260, 262 can be adjusted independently.
In Figures 1 and 2 , the second volume adjustment mechanisms 162, 262
are in the position closest to the pump inlet 22 which means that there is a
smaller volume for the molten metal to fill at this end of the feed troughs 130,
230. The first adjustment mechanisms 160, 260 are in the position closest tothe
pump inlet, which in this case means that a larger volume of molten metal is
required to fill this end of the troughs 130, 230.
In use, a supply (not shown) is connected to the inlet 22, and is operated
to pump molten metal, such as for example molten lead, into the apparatus 1
through the inlet 22. The molten metal flows through the T-branches 24, 26;
along the outer feed passages 140, 240; through the connections 146, 246 and
into the inner feed passages 142, 242. As the volume of molten metal in the
apparatus increases, the molten metal rises up through the vertical passages
148, 248 and into the feed troughs 130, 230. As more molten metal flows into
the apparatus 1, the level of molten metal M in the feed troughs 130, 230 rises.
When the level of molten metal M in the trough rises above the uppermost point
of the weir 133, 233, the metal flows over the weirs and into the cavities 110,
120.
To provide greater control of the filling process, the pump can be
operated a first, slower speed until the molten metal in the feed troughs 130, 230
reaches a pre-fill height p (shown in Figure 4). The pump then can be adjusted
to maintain the pre-fill height of the molten level to allow the molten metal to
reach a stable condition; this can be referred to as operating at the tick-over
speed. The pump can then be operated at a faster speed to more rapidly
increase the level of molten metal in the feed trough 130, 230 to a level a above
the weir height (shown in Figure 4) in order to fill the mould cavities 110, 210.
The volume adjustment mechanisms at both ends of the two feed troughs
can be moved independently to adjust the volume of that portion of the feed
trough (i.e. to extend or reduce the length of the trough at that end of the mould).
This allows an operator to balance the flow of molten metal into the cavities
along the length of the both mould blocks, so that all of the mould cavities are
filled at the same time and at the same rate. The mould cavity fill process can
therefore be controlled and balanced side-to-side as well as longitudinally.
While the invention has been described above with reference to one or
more preferred embodiments, it will be appreciated that various changes or
modifications may be made without departing from the scope of the invention as
defined in the appended claims.

Claims
1. An apparatus for moulding battery components comprising:
a mould block having a plurality of mould cavities;
a molten metal feed trough adjacent to the mould block and
extending in a generally longitudinal direction along the mould block;
a plurality of weirs between the feed trough and each of the
cavities;
a supply for providing molten metal to the trough; wherein the feed
trough is provided with at least one volume adjustment mechanism, which
is operable to alter the volume of the feed trough.
2 . An apparatus according to claim 1, wherein the feed trough comprises a first
end; a second end and a central portion, the plurality of weirs being provided
along the central portion; and
wherein two volume adjustment mechanisms are provided, one at each
end of the feed trough, the volume adjustment mechanisms being
independently adjustable.
3 . An apparatus according to any of the previous claims, wherein the, or each,
volume adjustment mechanism is arranged to be adjusted between a
plurality of indexed positions.
4 . An apparatus according to any of the previous claims, wherein the, or each,
volume adjustment mechanism is arranged to provide an adjustable end wall
which may be used to adjust the length of the trough in use.
5 . An apparatus according to any of the previous claims, wherein the, or each,
volume adjustment mechanism comprises an element which is arranged to
be received within the feed trough.
6 . An apparatus as claimed in claim 4 , wherein the element is longitudinally
slideable within the feed trough.
7 . An apparatus according to claim 5 or 6 , wherein the volume adjustment
mechanism further comprises a locking member arranged to secure the
element in position.
8 . An apparatus according to claim 7 , wherein the element is provided with
castellations along its upper surface which define a plurality of notches or
recesses to be engaged by the locking member.
9 . An apparatus according to any of the previous claims, wherein the supply
comprises:
a feed passage extending below the feed trough;
a plurality of substantially vertically extending passages connecting the
feed passage to the feed trough;
a supply pump inlet in fluid communication with the feed passage, for
connection to a pump supplying molten metal.
10 .An apparatus according to claim 9 , wherein the feed passage comprises:
an inner feed passage extending below the feed trough and
connected to the feed trough;
an outer feed passage extending substantially parallel to the inner
feed passage, the supply pump inlet being in fluid communication with the
outer feed passage; and
at least one connection passage leading from the outer feed
passage to the inner feed passage.
11. An apparatus according to any of the previous claims, wherein the
apparatus extends longitudinally and the supply pump is provided at one end
of the apparatus.
12. An apparatus according to any of the previous claims, further comprising:
a second mould block, provided adjacent and parallel to the first
mould block, the second mould block having a plurality of mould cavities;
a second molten metal feed trough adjacent to the second mould
block and extending along the length of the mould block;
a plurality of weirs between the second feed trough and each of
the cavities;
a second supply for providing molten metal to the second trough.
wherein the second feed trough is provided with at least one
volume adjustment mechanism, which is operable to alter the volume of
the second feed trough.
13 .An apparatus according to claim 9 , wherein two further volume adjustment
mechanisms are provided, one at each end of the second feed trough, the
volume adjustment mechanisms being independently adjustable.
14. A method of moulding battery components comprising
providing a apparatus for moulding battery components including:
a mould block having a plurality of mould cavities; a molten metal feed
trough adjacent to the mould block and extending along the length of the
mould block; a plurality of weirs between the feed trough and each of the
cavities;
providing a supply arrangement for supplying molten metal into the
feed trough;
adjusting the volume adjustment mechanism to alter the volume of
the feed trough so that the molten metal flows over the weirs into the
plurality of mould cavities simultaneously.
15 .A method according to claim 14, wherein the step of adjusting the volume
includes moving volume adjustment mechanisms at one or both ends of the
feed trough in order to balance the flow of molten metal into the cavities
along the length of the mould block.
16. A method according to claim 14 or claim 15 , wherein
the step of adjusting the volume includes moving volume adjustment
mechanisms at one or both ends of the left and right feed troughs in order to
balance the flow of molten metal into the cavities along the length of the both
the left and the right mould blocks.
17 .An apparatus for moulding battery components substantially as described
herein.
18 .A method of moulding battery components substantially as described herein.