U.S. patent number 3,795,964 [Application Number 05/287,962] was granted by the patent office on 1974-03-12 for forming and placing tubular battery separators.
This patent grant is currently assigned to ESB Incorporated. Invention is credited to Milo H. Beckman.
United States Patent |
3,795,964 |
Beckman |
March 12, 1974 |
FORMING AND PLACING TUBULAR BATTERY SEPARATORS
Abstract
Battery separator material in strip form and cut to proper size
is entered tangentially into a borehole. Air streams directed
tangentially to the borehole cause the strip of material to roll up
into a tube of controlled diameter. When the tube is wound, a
pressure differential between the two ends of the borehole causes
the tube to eject into a waiting battery assembly placed on the
trajectory of the rolled tube.
Inventors: |
Beckman; Milo H. (Madison,
WI) |
Assignee: |
ESB Incorporated (Philadelphia,
PA)
|
Family
ID: |
26782480 |
Appl.
No.: |
05/287,962 |
Filed: |
September 11, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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90641 |
Nov 18, 1970 |
3736655 |
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Current U.S.
Class: |
493/304; 29/235;
29/451; 29/730; 72/60; 264/339; 425/387.1; 425/403; 493/450;
493/472 |
Current CPC
Class: |
B29C
53/40 (20130101); B31C 1/00 (20130101); Y10T
29/49872 (20150115); B29C 2793/0081 (20130101); Y10T
29/53135 (20150115); Y10T 29/53657 (20150115) |
Current International
Class: |
B29C
53/00 (20060101); B29C 53/40 (20060101); B31C
1/00 (20060101); H01m 003/00 () |
Field of
Search: |
;264/339,322 ;29/592,204
;72/54,56,60,146 ;425/387,403 ;93/81R ;271/74,26 ;214/1BE,1.4
;302/25,30,31,46 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Spicer, Jr.; Robert L.
Claims
I hereby claim:
1. A machine for forming a tubular battery separator from a sheet
of battery separator material which comprises:
a. a block of material having a borehole passing from one end to
the other;
b. a slot piercing the block from one side to the borehole parallel
with the axis of the borehole and tangential to the wall of the
borehole.
c. external first air jet means directed to the slot in the
block;
d. second air jet means located within the block tangential to the
borehole; and
e. means producing a pressure differential between one end and the
other end of the borehole; whereby when a piece of separator
material is placed in the vicinity of the first air jet means, it
is transported via the slot into the influence of the second air
jet means, the sheet of material then being rolled into a tube
approximating the size of the borehole by the action of the second
air jet means and by the pressure differential producing means, the
so-formed tube is ejected from the borehole.
2. A machine as defined in claim 1 in which the pressure
differential is caused by at least one baffle means covering parts
of the borehole.
3. A machine as defined in claim 1 in which the means producing the
pressure differential comprises a baffle means partially covering
one end of the bore hole and guide means is located along the path
of the piece of material prior to its entry into the slot; whereby,
prior to and during the tube forming operation, the tube is
constrained from being ejected from the borehole by the guide means
and after the tube is formed being no longer constrained by the
guide means is ejected from the borehole by the pressure
differential.
4. A machine as defined in claim 1 in which the pressure
differential producing means comprises moveable baffle means
whereby during the tube forming period, the moveable baffle means
is located in a first baffle position preventing the ejection of
the tube and when the tube is formed, the moveable baffle means is
located in a second baffle position producing a pressure
differential causing the tube to be ejected from the borehole.
5. A machine as defined in claim 1 further characterized by a cell
assembly placed axially with the bore hole whereby when the tube
formed of the sheet is ejected from the borehole, it locates within
the cell assembly.
6. A machine as defined in claim 1 further characterized by a feed
means feeding separator sheets to the first air jet means.
Description
BACKGROUND OF THE INVENTION
a. Field of the Invention
This invention relates to a method and apparatus for forming short
tubes of non-woven textile material. Specifically, it relates to
the method and the equipment required for the formation of a
battery separator or tubular shape.
B. Description of the Prior Art
The manufacture of tubular articles of paper and paper-like
materials has been developed to a high degree of refinement. A
great many tubes are formed by spiral winding techniques and this
is the generally accepted production method. Machines are available
which will produce spiral wound tubes at rates up to one or more
yards per second. Such tubes are usually bonded by adhesive applied
during the lay-up operation. The spiral wound equipment usually
includes a mandrel on which the tube is formed. Automatic cut-off
devices can be provided on the tube winding machine to provide
tubes of a suitable length for the produce needs.
In another form of tube making equipment, the paper web is fed
tangentially to a rotating mandrel to form a parallel wound tube.
This form of machine is used in general where the volume of
production does not warrant the spiral wound type of equipment.
This type of equipment is also used when it is desired to construct
tubes having a thick wall. Paper tubes up to a foot or more in
diameter and having walls up to one-half inch thick can be so
prepared. The length of the tube is, of course, determined by the
width of the paper web available. It is usual in this case to bond
the paper with glue to prevent the tube from unwinding.
In certain forms of small batteries, a tube of non-woven fabric
material is used for separation between the depolarizer mix and the
anode material. In this form of battery, it is desirable to avoid,
if possible, the use of a glue material on the separator as this
can provide a source of undesirable chemical contamination in the
cell. In the assembly of these cells, the separator is placed
within a cylindrical cavity formed by the depolarizer. It is
desirable that the tube of separator material be slightly smaller
in diameter than the cavity so that it can easily be inserted
therein. After the separator is inserted, it should then be
expandable so as to form a tight lining on the inside wall of the
depolarizer mix. This is another reason for forming the tube
without a binder. The usual spiral wound tube does not lend itself
to this application for the following reasons. First, the tube must
be wound without glue. It is very difficult to wind and even more
difficult to cut a spiral wound tube formed without a binder.
Second, the spiral wind leaves angular pointed ends which can
easily catch during insertion or which may become mispositioned in
later steps of cell manufacture. Third, the spiral wound tubes
without glue tend to unwind of themselves and thus make insertion
more difficult.
Thus, the parallel wound tube is a better choice for use as a
battery separator. However, the usual form of parallel wound tube
is bonded. If it is not bonded, it will unroll and tus it becomes
difficult to handle.
SUMMAY OF THE INVENTION
A web of material suitable for use as a battery separator is fed
from a roll to a cutting device where pieces of material of
suitable size are successively cut. As each sheet of material is
severed from the web, it is transported by a first air jet to a
slot in a block of material. The slot is directed tangentially to a
borehole in the block. A second air jet, tangential to the
borehole, pulls the sheet into the borehole and causes it to roll
up into a tubular shape. When the tube is completely formed, it is
ejected from the borehole and into a battery cell assembly
positioned on its trajectory.
The transfer of the tube from the borehole is accomplished by
establishing a pressure differential between the two ends of the
borehole. This can be accomplished by a third air jet directed
through the borehole or by closing or partially closing one end of
the borehole so as to bias the exhaust of the second jet in the
desired direction of movement.
The simplicity of this quite specialized tube forming device is its
most obvious feature. There are no handling devices needed other
than the air blasts. Controls, either for the auxiliar air blast or
for the borehole closing pressure differential establishing means
can be simple and dependable.
The entire opeation starting from flat sheet and ending with the
finished tube located in its final position in the cell assembly
takes place in a very short period of time.
The time required to transfer the tube from the borehole to the
cell is so short, that the tube is not able to unwind or otherwise
hinder its insertion in the cell. Finally, the locations and the
adjustments of the several air blasts are not critical.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an elevation of one form of machine for implementing
the method of the invention;
FIG. 2 shows a plan view of the same machine;
FIG. 3 and 4 show in elevation a detail of a part of the machine of
FIG. 1 at two phases of its operational cycle;
FIG. 5 shows an end view of the machine of FIG. 1 near the end of
the operational cycle;
FIG. 6 shows a plan view of a second embodiment of a machine for
implementing the method of the invention; and
FIG. 7 shows a plan view of a third embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, an elevation of a tube forming machine made in
accordance with the invention, a sheet 20 of non-woven fabric or
other separator forming material of suitable size has been placed
on table 22. A block of metal 24 having a cylindrical borehole 26
therethrough and a slot 28 tangential to the borehole and on the
same plane as the surface of the table 22 is located at one of the
table ends. An air jet 30 is located above table 22 and is adjusted
to convey the sheet 20 into the tangential slot 28 of block 24. A
second air jet 32 is located in block 24 in a position tangential
to the borehole and roughly perpendicular to slot 28. FIG. 2, a
plan view of the machine shows in addition to the parts enumerated,
a baffle 34 covering part of the opening of the borehole, and guide
plates 36 attached to the sides of table 22. The baffle is omitted
from FIG. 1 for clarity. The transverse location of the air jet 32
at the longitudinal midpoint of block 23 is also shown. A
cylindrical cell can assembly 40 having a tubular lining 42 of
depolarizer mix is located on the axis of the bore hole 26. The
open end of cell can 40 faces block 24 and the closed end 44 faces
away from it.
In FIG. 3, the action of air jet 30 has caused the sheet 20 to
enter slot 28 and start to curl. In FIG. 4, due to the action of
air jet 32, the entire sheet is rolled up into a tube 40. The
external diameter is approximately, but slightly less than, the
borehole. FIG. 5 illustrates the condition occurring as soon as the
tube is fully formed. Baffle 34 is shown partially covering the
right hand end 46 of borehole 26. The effect of baffle 34 is to
cause a higher pressure at the right hand end 46 of the borehole
than at the left hand end 48. The pressure differential causes more
exhaust air from jet 32 to move to the left of FIG. 5 than to the
right. While the tube is being formed, it is constrained from
moving because of the guide plates 36. However, as soon as the tube
40 is formed and free of the constraint of guides 36, it is ejected
by the pressure differential from the borehole 26. In FIG. 5, tube
38 is shown passing to the left out of borehole 26 and into the
cell assembly. The velocity of tube 38 is sufficient to place it in
its permanent location in the cell assembly. When the finished tube
has come to rest in the cell assembly, it springs outward due to
its inherent resiliance and conforms to the inside of the lining of
depolarizer in the cell assembly.
The amount of pressure differential and hence the speed with which
the formed tube 38 is forced from the borehole 26 is controlled by
the amount by which baffle 34 covers the end 46 of the
borehole.
An alternate embodiment is shown in plan view in FIG. 6. In this
view, the baffle 34 and the guide plate 36 shown in FIG. 2 are
omitted. Instead, there is a third air jet 50, directed along the
axis of the borehole. With this embodiment, the tube, after being
formed by the action of air jet 32, remains in the borehole 26
until air jet 50 is activated. This causes an increase of pressure
at the right end 46 of the borehole which in turn forces the
completed tube 38 out of the borehole.
In a third embodiment, shown in end elevation in FIG. 7, two
moveable baffles 60 on the left and 62 on the right are shown
partially covering either end of the borehole 26 in block 24. When
the tube is fully formed, baffle 60 is raised to clear the
borehole. A pressure differential is established between the two
ends of the bore hole causing the full exhaust blast of air jet 32
to escape to the left, carrying the finished tube with it. In FIG.
7, a device for feeding and cutting the separator web is also
shown. The roll of web material 64 is led through a pair of
indexing feed rolls 66. From the feed rolls, the web passes through
shears 68. By well known mechanical means (not shown) feed rolls
pull a measured length of web material from roll 64. Shears 68 cut
the measured length of web allowing it to drop on the table in
front of block 24. The web is immediately picked up by the first
air jet, and rolled up by jet 32. Baffles 60 and 62 then raise
causing the wound separator tube to shoot into waiting cell
assembly 40. Cell assembly 40 is shown located in an indexing
device, in this case, a dial feed wheel. Means (not shown) are
provided for coordinating the motion of the feed device with the
motion of the shear 68 and the baffles 60 and 62, so as to move an
empty cell assembly into line with the borehole 26 each time a
sheet of web material is cut.
It will be seen from this description that the method of the
invention for forming tubular battery separators is simple and
speedy and the equipment used in its embodiment neither costly nor
complicated. Although three methods for causing the formed tube to
eject from the borehole are described, the invention is not limited
to these only, but covers the broader area of providing a
differential air pressure at the two ends of the borehole.
Having thus fully described the method of my invention and given
examples for its embodiment by the use of simple machine
elements
* * * * *