AN IMPROVED METHOD OF AND APPARATUS FOR INSERTING FILTER BAGS INTO SHEATHS OR CASINGS
Year: 1884

page_text: CORT DELE
I WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, & Co, Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the nature
of my invention for "AN IMPROVED METHOD OF AND APPARATUS FOR INSERTING
FILTER BAGS INTO SHEATHS OR CASINGS and in what manner the same is to ba
performed, to be particularly described and ascertained in and by the following
statement:
"
This invention relates to an improved method of inserting the canvas bags
used in sugar rofineries for filtering the sugar or liquor, into the canvas sheaths
or casings which contain the bags during the filtering operation and to apparatus
therefor.
The filter bags are usually several feet in length and when in use are suspended
from nozzles in the bottoin of a reservoir or tank containing the sugar liquor, and
receive the liquor which percolates through the meshes of the bags leaving its
impurities therein. After several hours use the bags become so clogged or choked
by the accumulated impurities that they have to be removed and washed. When
the bags are in use each is contained in a stout woven sheath of smaller diameter
than the bag, the sheath preventing the pressure of the column of liquor from
distending the bag and thus choking its meshes or pores. When the bags are
washed they have to bo withdrawn from their shoaths and replaced therein after
washing. The operation of replacing the filter bags in their sheaths is one of
considerable magnitude in view of the large number employed and of the fact that
the bags are larger than the sheaths and therefore have to be reduced to a compact
form before they can enter the sheaths.
In many refineries the bags are inserted in their sheaths by a workman who
gathers the bag into longitudinal folds to make it compact, throws it over his

page_text: shoulder, and then, holding the sheath and manipulating the sheath and bag,
gradually works the latter into the former. Other methods equally primitive and
slow prevail at other refineries, but invariably, so far as I am aware, the method,
prior to my invention, has been so slow and laborious that the need of a more
rapid and effective method has long been felt. My improved method consists in 5
drawing the bag into a tubular receptacle which gives the bag the desired
compactness, and then ejecting the compacted bag into the sheath, the end of the
lutter being held over the mouth of the tube. The invention also consists in the
provision of means for alternately drawing the bag into, and ejecting it from,
the tube by alternately exhausting the air from, and admitting it to, the interior 1
of the tube, the latter being arranged vertically with its receiving end at the
bottom, so that when the air is exhausted it will elevate a piston provided with
clamps which grasp the upper end of the bag, and when the air is admitted
the piston and bag will fall by gravitation, the bag being thus inserted in the
sheath.
The invention also comprises certain details of construction, all of which I will
now proceed to describe.
In the accompanying drawing
Figure 1 is a side elevation of an apparatus embodying my invention.
Figure 2 is a vertical section of the same.
Figure 3 is a vertical section of a portion of the apparatus showing the bag at
the commencement of its upward movement.
Figure 4 is a vertical section showing the sheath applied to the lower end of the
tube and the bag in its downward movement into the sheath.
Figures 5 and 6 are views of modificatons hereinafter described.
Similar letters of reference indicate corresponding parts in the several Figures.
In carrying my invention into practice I provide a tube a of suitable length
to contain a filter bag. Said tube is supported by any suitable means in a
substantially vertical position, with an unobstructed vertical space below its lower
end equal to the length of the filter bag. Within the tube a is a piston b, which
fits the interior of the tube somewhat closely and is adapted to "slide therein.
The piston is provided with devices, hereinafter described, for grasping the upper
end of a filter bag c, and is connected by a chain or other flexible device d with a
support c at the upper end of the tube, the chain supporting the piston when it
drops to the lower portion of the tubo, as shown in Figure 2. From the upper
portion of the tube extends a pipe ƒ through which the air may be exhausted from
the tube. Said tube may communicate with any suitable exhausting apparatus
such as a steam ejector or injector, or, if desired, an air pump. I have employed
a "Korting" exhauster with good results, the air being set in motion and
exhausted from the tube by the motion of the steam through the exhauster, in a
manner well known and understood.
The pipefis provided with a self closing valve g which automatically shuts off
the tube a from the air exhausting apparatus, and is controlled by an operating
rod h adapted to be easily reached by the operator at the lower end of the tube.
In the operation of the apparatus the upper end of a filter bag is grasped by the
grasping devices of the piston; and the valve g is opened by the operator. The
valve may be secured in an open position as long as the operator desires, by the
engagement of the handle h¹ of the operating rod h with a slotted ear i on the side
of the tube a, as shown in Figure 3. The air is at once exhausted from the tube
by the exhauster which operates continuously. The partial vacuum thus produced
raises the piston to the upper portion of the tube and holds it there as long as the
valve g remains open. The bag c is thus drawn into the tube and is compressed
or folded into the desired compact form by the inner surface of the tube. While
the bag is thus raised and held, the operator places a sheath j over the lower end
of the tube a, as shown in Figure 4, and then releases the operating rod h thus
allowing the valve g to close,

page_text: Air being then admitted into the tube above the piston as herein after described
the piston is released and falls with the bag c until arrested by the chain d, the
bag being thus inserted neatly and smoothly into the sheath. The grasping devices.
with which the piston is provided are a series of fingers k pivotted at to an.
extension of the piston b, and provided with short arms at their upper ends,
against which bears a bolt or plunger m adapted to slide in a cavity o in' the
piston, and pressed downwardly by a spring n in said cavity. The pressure of
the plunger m on the arms k¹ throws the fingers & outwardly when they are below
the lower end of the tube, as shown in Figure 2. The fingers are thus in an open
condition, when the end of the bag is placed between them before it is drawn into
the tube, and said fingers are forced inwardly and caused to grasp the bag by the
inner surface of the tube when the piston commences its upward movement.
When the piston drops the fingers emerge from the lower end of the tube and are
caused by the spring n to release the bag, when the latter is fully inserted in its
sheath. The action of the fingers in grasping and releasing the bag is therefore
automatic.
The piston is provided with a shell or receptacle p, at its upper end, which
receives the chain & as the piston rises, and thus prevents the chain from rubbing
against the inner surface of the tube. The support e, to which the upper end of
the chain is attached, is a screw threaded rod passing through a smooth surfaced
aperture or guide in the upper end or head a¹ of the tube a, and is provided above
said head with a nut q resting on a spring which is interposed between the said
nut 9 and head a'. Said spring cushions the rod or support e, and prevents a
shock or jar when the piston is arrested in its downward movement by the chain.
The threaded rode and its nut enable the chain to be adjusted so as to support the
piston at any desired height when it is at rest. The head a' is provided with air
holes 8 which are covered by the spring r, the latter being a block or ring of india-
rubber. A spiral springt located in a casing presses downwardly on the nut q,
and presses the spring downwardly on the head a', the spring 7 serving as a
valvo, covering the orifices t. The piston in its upward movement strikes an
enlargement or spider e¹ on the rode and raises said rod with the valve or spring r,
thereby uncovering the air holes 8 8. Air is thus admitted which destroys the
vacuum and partially checks the upward movement of the piston. Said movement
is additionally checked by the spiral spring which resists the upward movement
of the rod c. These two instrumentalities cause the piston to stop quickly without
any violent concussion. The spring presses the valve or spring r against its sent
when the upward movement of the piston is arrested, and thus closes the air
holes & 8, so that the piston cannot drop until air is admitted to the tube.
indicates a pipe adapted to admit air to the tube for the purpose of releasing
the piston. Said pipe has a self closing valve g' having operating devices similar
to those provided for the valve g, the operator being thus enabled to open the
valve and admit air to the upper portion of the tube when he is ready for the
piston and compressed bag to drop into the sheath. The rapidity of the downward
movement of the piston may be regulated by means of an adjustablo cap, or nut v
adapted to cover to any desired extent air holes w in the outer portion of the tube x,
the rapidity of the downward movement of the piston increasing in proportion to
the extent to which said holes are uncovered. A set screw or check bolt y
positively holds the cap in any position to which it may be adjusted. The
described apparatus performs the operation of sheathing filter bags much more
rapidly than any means used heretofore.
I do not limit myself to the details of construction above described, nor to the
employment of air exhausting apparatus as a means for drawing the bag into the
tube, as a mechanical device or plunger may be employed for the same purpose
without departing from the nature of my invention.
In the modification shown in Figures 5 and 6 a lever is pivotted to the tube a
and engages at opposite sides with the rods by which the valves g and g' aro

page_text: opened. The operator by depressing either end of the lever causes that end to
pull down the rod h engaged therewith and thus open the valve to which said rod
pertains. The lever has a weighted offset hs which acts to hold the lever
when it is inclined, and thus prevents the spring of the opened valve from acting
to close the valve. When the lever is in a horizontal position its weight has no
effect.
The valve g' is not essential and may be omitted. The apparatus will operate if
air is admitted continuously through the holes w into the tube while the piston is
being raised.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
First The improved method of sheathing or encasing filter-bags, consisting in
drawing the bag into a tube and thereby compressing it, and then ejecting the
compressed bag from said tube into a sheath, as set forth.
Second. A tube adapted to receive and compress a filter-bag, combined with
means for inserting such bag into the tube, and means for ejecting or discharging it
therefrom into the sheath, as set forth.
Third A tube adapted to receive and compress a filter-bag, combined with a
piston adapted to move in said tube, and provided with means for holding the
bag, and means for exhausting the air from the tube above the piston, as set forth.
Fourth The combination of a tube adapted to receive and compress a filter-bag,
and provided at its upper end with a pipe communicating with an air-exhausting
apparatus, a valve whereby the tube may be put in communication with, or shut
off from, the exhausting apparatus, and a piston adapted to slide in the tube and
provided with bag-holding devices, as set forth.
Fifth The combination of a tube adapted to receivo and compress a filter bag,
and provided at its upper end with a pipe communicating with an air-exhausting
apparatus, a self closing valve for said pipe, an operating rod or device whereby
faid valve may be opened, means whereby said valve may be held in an open
position, and a piston adapted to move in said tube and provided with bag-holding
devices, as set forth.
Sixth The tube and means for exhausting air therefrom, combined with the
piston provided with bag-holding devices, and a chain or equivalent flexible
device connecting the piston with a support at the upper portion of the tube, as
set forth.
Seventh. The tube and means for exhausting air therefrom, combined with the
piston provided with bag-holding devices, a chain or equivalent flexible device
connected to the piston, and a support for the upper end of said chain bearing on
a spring or cushion, whereby the jar attending the fall of the piston is relieved, as
set forth.
Eighth The combination of the tube, the supporting chain and the piston having
a receptacle p for said chain, as set forth.
Ninth. The combination of the tube with the piston having the pivotted
grasping fingers normally thrown outwardly or separated by spring pressure, and
adapted to be moved inwardly by contact with the tube when the piston is raised,
as set forth.
Tenth. The combination of the tube, the bag-raising piston, air-exhausting
apparatus communicating with the tube, air-inlets at the upper portion of the tube,
a valve adapted to normally cover the air-inlets and provided with a rod or stem
adapted to be raised by the upward movement of the piston and thereby admit air
to check said movement, and a spring whereby the upward movement of the piston
is additionally checked, as set forth.
Eleventh The tube having the bag-raising piston, combined with air-exhausting
apparatus whereby the piston may be raised in the tube, and an adjustable air

page_text: inlet whereby the rate of downward movement of the piston may be regulated, as
set forth.
Twelfth. The combination of the tube, an air-exhausting apparatus therefor, the
bag-raising piston, and an air-inlet pipe having a valve whereby air may be
admitted to the tube to release the raised piston, as set forth.
Dated this 7th day of October 1884.
HASELTINE, LAKE & Co.,
For the Applicant.