Patent Description:
Electric storage batteries may include bipolar plates and an electrolyte. A lead acid battery may include a plurality of bi-polar plates and a sulfuric acid electrolite. The bi-polar plate may include a frame or substrate with electrodes on both sides, an absorbant glass mat (AGM) separator with a positive paste (active material) applied to one of the electrodes and a negative paste with an AGM separator applied to the other electrode.

Prior approaches to applying the battery paste and an AGM separator to an electrode of a bi-polar battery plate have a low rate of mass production and require a significant capital investment for a specially designed production line and equipment to do so.

A system, apparatus and method for cutting battery grids or plates from a continuous strip of a plurality of connected battery grids are described in <CIT>. The continuous strip moves toward a rotating cutter with at least two cutter blades with cutting edges equally circumferentially spaced apart and extending parallel to the cutter axis of rotation and a rotating cooperating anvil. The cutting edges and the anvil are rotated at the same tangential speed to cut in a nip between them a plate or grid from the continuous strip of connected grids. At a point upstream of the cutter, an electric signal indicative of each lug of the grid of the continuous strip moving past this point is used to control the speed of movement of the strip through the nip to cut a plate or grid from the continuous strip at a longitudinal speed which is essentially the same as the tangential speed of the cutting edges.

<CIT> describes a battery grid pasting system including a battery grid pasting machine, a sensing station, and a controller. The battery grid pasting machine includes a conveying apparatus confronting a hopper's dispensing end across a space, and includes a motor actuatable to cause variance of the space and hence variance of the amount of battery paste received on carried battery grids through the space. The sensing station senses a value of a property of a pasted battery grid. And the controller receives the sensed value of the property and controls actuation of the motor based in part or more on the received value.

Finally, a thin battery and a manufacturing method of a thin battery are described in <CIT>. The thin battery comprises an anode material, a cathode material, two or more separator paper layers there between, and electrolyte. One of the outer separator paper layers has an anode material applied thereon, another separator paper layer being an outer layer on the opposite side having a cathode material applied thereon. The method of the invention for manufacturing such a thin battery is mainly characterized by the steps of wetting a separator paper with an electrolyte solution, applying an anode material on a first separator paper and applying a cathode material on a second separator paper. The separator papers are then combined by pressing them together so that the anode and cathode materials are outmost, respectively in order to form a layered structure. The combined layers are then cut in desired sizes.

The present invention provides a line for making, pasting and applying separators to substrates for battery plates according to independent claim <NUM> and a method of making, pasting, and applying separators to substrates for batter plates according to independent claim <NUM>. Further preferred embodiments result from the dependent claims.

A method of making, pasting and applying separators to substrates of a battery plate includes providing a longitudinally elongate web of separator material having first and second opposites sides, applying a layer of battery paste to one of the first and second sides of the web, severing the pasted web into a series of separate individual separators with paste on the one side, disposing a separate separator of the series on one of a series of substrates with the pasted one side facing the substrate on which it is disposed. To dispose an individual separator on a substrate, the separator is turned over end for end by reversing its direction of travel relative to the direction of travel of the web before such separator was severed from the web. After an individual separator is disposed on its associated substrate such substrate may be turned over and the foregoing steps repeated to dispose another individual separator on the other side of such substrate.

The substrate may include a planar panel portion with at least one and usually a plurality of spaced apart protuberances projecting outwardly of both sides of the panel and before pasting a corresponding clearance hole or holes may be formed through the web so that each pasted individual separator may be disposed on one substrate with each of the one or more protuberances received within a clearance hole of the separator deposited on the one substrate. The substrate may include an edge extending around the panel and projecting outwardly thereof and each individual separator may be disposed within the edge of its associated substrate.

A mass production line for making, pasting and applying an individual separator to a substrate includes advancing a longitudinally elongate web of separator material through a paster station to apply a layer of paste to one side of the web, severing the web to produce a series of separate individual separators of a desired predetermined length with paste on the one side, a transfer station disposing an individual separator on one of a series of substrates with the pasted one side facing the substrate on which it is disposed. Upstream of the paster station a wound roll of a web of separator material may be unwound from the roll and disposed on a moving belt advancing the web under a hopper of a pasting machine to apply paste to one side of the web, and downstream of the paster station the pasted web is received on a rotating transfer cylinder and the pasted web is separated into individual separators on the cylinder. The cylinder disposes one of the individual separators on one of a series of substrates being advanced with respect to the transfer cylinder. The transfer cylinder has vacuum ports retaining the individual separators on the cylinder and the vacuum is relieved to dispose the separators on the substrates. The separators are disposed on substrates being advanced in a direction generally opposite to the direction in which the pasted web is being advanced upstream of the transfer cylinder.

Upstream of the paster station, clearance holes may be formed through the web to register with protuberances of a separator. The clearance holes may be punched by a die and press mechanism or cut by rotary dies. The clearance holes may correspond to protuberances in the substrate so that an individual separator may be deposited on a substrate with the protuberances received in the clearance holes. A belt advancing the web through the paster station may have protrusions or bosses registering with and received in the clearance holes formed through the web so that paste is inhibited from being deposited in the clearance holes.

The following detailed description of certain embodiments and best mode will be set forth with reference to the accompanying drawings, in which:.

Referring in more detail to the drawings, <FIG> illustrate a bipolar plate assembly <NUM> such as a plate for a lead acid battery with electrically conductive electrodes <NUM> and <NUM> received on opposed faces <NUM> and <NUM> of a frame or substrate <NUM> with a layer of paste <NUM> received on the electrode <NUM> with a separator <NUM> over the paste <NUM> and a layer of paste <NUM> received on the electrode <NUM> with a separator <NUM> over the paste <NUM>.

The substrate <NUM> may have a generally planar panel <NUM> with raised edges <NUM> extending around its perimeter and projecting outwardly from both faces <NUM> and <NUM> of the panel <NUM>. The electrodes <NUM>, <NUM>, paste <NUM>, <NUM> and separators <NUM>, <NUM> may be received within the edges of the substrate <NUM>. The panel <NUM> may also include at least one and usually a plurality of spaced apart protuberances <NUM> arranged in a predetermined configuration and projecting outwardly of both faces of the panel <NUM>. The protuberances <NUM> may have a circular perimeter and planar outer faces and at least some of the protuberances <NUM> may have through-holes <NUM> which when assembled in a battery may provide channels or passages extending transversely through a series of stacked plates. The substrates <NUM> may be of a suitable plastic material which may be dielectric. The separators <NUM> and <NUM> may have clearance holes <NUM> in which the protuberances <NUM> are received.

For a bipolar lead acid battery plate <NUM>, the electrically conductive electrodes <NUM> and <NUM> may be a thin sheet of film or lead or lead alloy received on its associated face of the substrate <NUM> and if desired may be attached to the substrate <NUM> by a suitable adhesive. To provide an anode, one of the electrodes <NUM>, <NUM> may be coated with a layer of negative paste (active material) and to provide a cathode, the other electrode <NUM>, <NUM> may be coated with a layer of positive paste (active material), and the separators <NUM>, <NUM> may be made of an absorbent glass mat (AGM) or other layer or film of a suitable porous material. The separators <NUM>, <NUM> and the layers of paste <NUM>, <NUM> may encircle the protuberances <NUM> but at least substantially do not overlay the outer faces of the protuberances <NUM>. The construction of bipolar lead-acid battery plates and their assembly and use in a lead-acid battery is known and understood by persons skilled in the art and thus will not be further described.

As shown in <FIG> a mass production line <NUM> may make and paste a series of separators <NUM>, <NUM> and apply them to one face of a series of separate substrates <NUM>. The substrates <NUM> may then be turned over and a second production line substantially the same as the first line <NUM> may make and paste a series of separators and dispose them on the other side of the series of substrates to provide battery plates <NUM> with both electrodes <NUM>, <NUM> having a layer of paste <NUM>, <NUM> thereon covered by an associated separator <NUM>, <NUM>. Typically, one of the production lines <NUM> would apply a positive paste on a separator <NUM>, <NUM> received on one side of the substrate <NUM> and the other line would apply a negative paste and an associated separator <NUM>, <NUM> received on the other side of the substrate <NUM> to provide a bipolar battery plate <NUM>. Unipolar plates or end plates with paste and a separator on only one side of a plate may also be made by a production line <NUM>.

As shown in <FIG> and <FIG> the production line <NUM> may include an unwinding station <NUM> for a roll <NUM> of a longitudinally elongate web <NUM> of an absorbent glass mat (AGM), a station <NUM> forming clearance holes <NUM> through the web <NUM> for receiving protuberances <NUM> of substrates <NUM>, a feed station <NUM> for unwinding the roll <NUM> of web <NUM> and moving the web <NUM> through the clearance hole forming station <NUM>, a paster station <NUM>, a cutter station <NUM> to sever the pasted web <NUM> into separate individual separators <NUM>, <NUM> of a predetermined length, and a transfer station <NUM> to dispose an individual pasted separator <NUM>, <NUM> on an associated one of a series of separate substrates <NUM> advanced through the transfer station <NUM> such as by a conveyor <NUM>. Downstream of the transfer station <NUM>, desirably the pasted separator <NUM>, <NUM> may be slightly pressed onto its associated substrate <NUM> such as by passing them and an underlying portion of a conveyor belt <NUM> through the nip of a pair of rollers <NUM> and <NUM>. This may provide a substantially uniform thickness of the substrates <NUM> with the paste <NUM>, <NUM> and separators <NUM>, <NUM> thereon, ensure good contact of the paste <NUM>, <NUM> with its associated electrode <NUM>, <NUM> and sufficiently attach the separator <NUM>, <NUM> to its associated pasted substrate <NUM> to facilitate subsequent assembly of plates into a battery.

In the unwinding station <NUM>, a roll of an elongate web <NUM> of separator material such as an AGM may be received on a rotatable arbor <NUM> and in operation of the line <NUM> unwound by the web <NUM> passing through the nip of a pair of feed rollers <NUM>, <NUM> driven for co-rotation by a desirably variable speed electric motor <NUM> such as a stepper motor. An adjustable air brake <NUM> may be connected to the arbor <NUM> to maintain the web <NUM> in tension or taut between the feed rollers <NUM>, <NUM> and the roll <NUM> of the web <NUM> as it is being unwound. If the substrate <NUM> includes protuberances <NUM>, corresponding clearance holes <NUM> may be formed in the web <NUM> in the station <NUM> such as by punching dies <NUM> received in and actuated by a press <NUM>. Alternatively, the clearance holes <NUM> in the web <NUM> could be formed by a pair of rotary dies through the nip of which the web <NUM> passes with the tangential speed at their nip being the same as the linear speed at which the web <NUM> is advanced through the forming station <NUM> by the feed rollers <NUM>, <NUM>. The pair of rotary cutting dies may be driven by a variable speed motor such as a stepper motor synchronized with the speed of the feed rollers <NUM>, <NUM> which may be driven desirably by another stepper motor <NUM>. Optionally, the clearance hole forming station <NUM> can be eliminated and any desired clearance holes <NUM> formed in the web <NUM> before it is wound into a roll <NUM> and placed on the arbor <NUM> of the unwinding station <NUM>.

In the paster station <NUM> the web <NUM> may be received on a upper run <NUM> of a continuous belt <NUM> received over a pair of spaced apart rollers <NUM>, <NUM> journaled for rotation with preferably the downstream roller <NUM> being driven by a variable speed electric motor <NUM> such as a stepper motor to advance the web <NUM> under a paste hopper <NUM> and through the paster station <NUM>. The belt <NUM> may be made of stainless steel and as shown in <FIG> may include circular protrusions or bosses <NUM> in a configuration complimentary to and received in the corresponding clearance holes <NUM> in the web <NUM> and desirably having an outer substantially planar face <NUM> substantially in the plane of the upper face of the web <NUM> to inhibit paste <NUM>, <NUM> applied to the upper face of the web <NUM> from entering the clearance holes <NUM> in the web <NUM>. The paste hopper <NUM> may be of conventional construction and in operation may discharge paste <NUM>, <NUM> through an orifice <NUM> onto the upper or first surface <NUM> of the web <NUM> as it is advanced under the orifice <NUM>. The orifice <NUM> may extend substantially across the transverse width of the web <NUM>.

Downstream of the paster station <NUM>, the pasted web <NUM> may pass into the transfer station <NUM> and be received on the periphery of a transfer cylinder <NUM> journaled for rotation and driven by a variable speed motor <NUM> such as a stepper motor. Desirably, while the web <NUM> is on the transfer cylinder <NUM> it may be severed into a series of succeeding separate individual pasted separators <NUM>, <NUM> such as by a cutter assembly <NUM> journaled for rotation and having at least one and desirably a plurality of cutter blades <NUM> of sufficient length to extend transversely across the web <NUM>. The speed of rotation of the cutter blades <NUM> may be synchronized with the rotary speed of the transfer cylinder <NUM> to provide the desired predetermined length of each individual separator <NUM>, <NUM> with the web <NUM> being severed in the nip between a rotary blade and the transfer cylinder <NUM>. The tangential velocity or speed of the periphery of the transfer cylinder <NUM> may be greater than the immediately upstream speed of the web <NUM> when it engages with the transfer cylinder <NUM> to provide a gap or spacing <NUM> between adjacent individual separators <NUM>, <NUM> received on the transfer cylinder <NUM>. This may also maintain tension on the pasted web <NUM> before it is severed. The cutter blades <NUM> may be rotated by a variable speed motor <NUM> such as a stepper motor.

The individual separators <NUM>, <NUM> may be retained on the transfer cylinder <NUM> by a vacuum applied to a plurality of circumferentially and axially spaced apart ports <NUM> opening onto the periphery of the transfer cylinder <NUM> and underlying the individual separators <NUM>, <NUM>. As the transfer cylinder <NUM> rotates it may depose an individual pasted separator <NUM>, <NUM> onto one of a series of substrates <NUM> by interrupting or stopping the vacuum applied to the ports <NUM> preferably sequentially and if need be by applying preferably sequentially an atmospheric or super atmospheric pressure to the ports <NUM>. Vacuum retaining and atmospheric or super atmospheric release pressure may be supplied to the ports <NUM> through adjustable slip rings <NUM> communicating with generally axially extending passages <NUM> in the transfer cylinder <NUM> communicating with the ports <NUM> which open into the passages <NUM>. If desired, after the vacuum ports <NUM> have released and deposited an independent separator <NUM>, <NUM> on a substrate <NUM> they may be rotatably advanced to communicate with slip rings <NUM> supplying to them a super atmospheric pressure to clean them before they are further rotated to receive and retain another individual pasted separator <NUM>, <NUM> severed from the web <NUM>.

The substrates <NUM> may be advanced under the transfer cylinder <NUM> by a conveyor <NUM> which may include a continuous belt <NUM> with a run underlying the transfer cylinder <NUM> and carrying thereon a series of equally spaced apart substrates <NUM>. This conveyor belt <NUM> may be driven by a variable speed motor <NUM> such as a stepper motor to advance the substrates <NUM> under the transfer cylinder <NUM> at the same or substantially the same linear speed as the tangential peripheral speed of the pasted surface of the individual separators <NUM>, <NUM>. Each separator <NUM>, <NUM> may be released from the transfer cylinder <NUM> and deposited on an underlying substrate <NUM> with its clearance holes <NUM> in registration with the substrate protuberances <NUM> and within the boundary of the edges <NUM> of such substrate <NUM>.

Downstream of the transfer cylinder <NUM>, if desired each substrate <NUM> with a pasted separator <NUM>, <NUM> received thereon may pass through the nip of cylindrical rotating rollers <NUM> and <NUM> to apply a force urging a separator <NUM>, <NUM> onto its associated substrate <NUM>. Desirably these rollers <NUM>, <NUM> are driven by a variable speed stepper motor <NUM> at the same tangential speed of their nip as the linear speed at which the combined separator <NUM>, <NUM>, paste <NUM>, <NUM> and substrate <NUM> is advanced through the rollers <NUM>, <NUM>.

In operation of the production line <NUM>, the various variable speed motors such as stepper motors may be controlled by a suitable conventional electronic controller <NUM> (known to skilled persons) to synchronize their various speeds and phase relationship of operation. For example, the speed of a preferably stepper motor <NUM> driving the paster belt <NUM> may be set to provide the desired rate of production and used as the set point for the speed and synchronization of separate preferably stepper motors operating each of the paste hopper <NUM>, clearance hole forming station punching or rotary dies, rotating the transfer cylinder <NUM>, and driving the conveyor <NUM> advancing the substrates <NUM> relative to the transfer cylinder <NUM>. To provide the desired length of the individual separators <NUM>, <NUM>, the speed and synchronization of the preferably stepper motor <NUM> driving the cutter assembly <NUM> (severing the web <NUM> into individual separators <NUM>, <NUM>) may also be varied and synchronized relative to the speed at which the transfer cylinder <NUM> is rotated.

The speed of the web feed rollers <NUM>, <NUM> may be varied and synchronized relative to the speed at which the paster belt <NUM> is advanced to maintain a slack loop <NUM> of the web <NUM> between the feed rollers <NUM>, <NUM> and the paster belt <NUM>. This maintaining of the length or depth of the slack loop <NUM> may be accomplished in various ways such as by synchronizing the speed of the feed rollers <NUM>, <NUM> with the speed at which the belt <NUM> advances the web <NUM> under the paste hopper <NUM> or more simply by sensors determining a minimum and maximum vertical depth of the slack loop <NUM> and providing signals to control the speed at which the feed rollers <NUM>, <NUM> driven by the motor <NUM> advance the web <NUM> to maintain the loop <NUM> between the desired maximum and minimum depth of the slack loop <NUM>. The speed or cycling of the clearance hole forming station press <NUM> operating the punching dies <NUM> or the speed of the rotary cutting dies may be varied and synchronized with the speed at which the feed rollers <NUM>, <NUM> advance the web <NUM> through the clearance hole forming station <NUM>. The magnitude of the resistance to the unwinding rotation of the web roll <NUM> produced by the air brake <NUM> may also be controlled relative to the extent to which the web <NUM> is unwound and advanced by the feed rollers <NUM>, <NUM> and if desired may be increased as the radius or diameter of the web roll <NUM> decreases as it is being unwound.

Claim 1:
A production line (<NUM>) for making, pasting and applying separators (<NUM>, <NUM>) to substrates (<NUM>) for battery plates (<NUM>) comprising:
a paster station (<NUM>) configured to apply a battery paste (<NUM>, <NUM>) to a first side of an elongate web (<NUM>) of a separator material;
a cutter station (<NUM>) downstream of the paster station (<NUM>) configured to sever the pasted web (<NUM>) into a series of separate individual separators (<NUM>, <NUM>) with paste on their first side; and
a transfer station (<NUM>) configured to dispose an individual separator (<NUM>, <NUM>) of the series on one of a series of substrates (<NUM>) with the pasted first side of the separator (<NUM>, <NUM>) facing the substrate (<NUM>) on which it is disposed, wherein the transfer station (<NUM>) includes a rotatable cylinder (<NUM>) on which individual separators (<NUM>, <NUM>) are received and releasably retained by a plurality of ports (<NUM>) opening onto the periphery of the cylinder (<NUM>) and underlying the individual separators (<NUM>, <NUM>), and thereafter individual separators (<NUM>, <NUM>) are released from the cylinder (<NUM>) by at least decreasing the vacuum applied to the ports (<NUM>) and disposed on an associated substrate (<NUM>), wherein
the cutter station (<NUM>) includes at least one blade (<NUM>) extending transversely across the web (<NUM>) and journaled for rotation to sever the web (<NUM>) into separate individual separators (<NUM>, <NUM>) in a nip between the at least one blade (<NUM>) and the rotatable cylinder (<NUM>) as the pasted web (<NUM>) passes through the nip, and
the transfer station (<NUM>) overturns the individual separators (<NUM>, <NUM>) end for end by reversing the direction of travel of the individual separators (<NUM>, <NUM>) relative to the direction of travel of the web (<NUM>) before the individual separators (<NUM>, <NUM>) were severed from the web (<NUM>) and deposits them on an associated substrate (<NUM>), and which also comprises a conveyor (<NUM>) advancing a series of substrates (<NUM>) relative to the transfer station (<NUM>) as individual separators (<NUM>, <NUM>) are deposited on the substrates (<NUM>) by the transfer station (<NUM>).