U.S. patent number 3,736,612 [Application Number 05/123,360] was granted by the patent office on 1973-06-05 for method of fitting ski boots.
This patent grant is currently assigned to Bass Sports, Inc.. Invention is credited to Gary B. Ader, Donald R. Check, Edward A. Pauls.
United States Patent |
3,736,612 |
Check , et al. |
June 5, 1973 |
METHOD OF FITTING SKI BOOTS
Abstract
A method of fitting ski boots using a conformable material made
up of separable small discrete particles covered with a film of a
lubricating or liquid material. The material is fluidized with air
under pressure for injecting the material into the pads, in order
to fit closely to the foot and to insure a close fit in a short
time. The apparatus includes a gun member which utilizes fluid
under pressure that forms a turbulent mixing zone and discharges
the material into the pad in a boot fitting, and which has means
for advancing the bulk material into the mixing zone as
necessary.
Inventors: |
Check; Donald R. (Bloomington,
MN), Ader; Gary B. (Eden Prairie, MN), Pauls; Edward
A. (Excelsior, MN) |
Assignee: |
Bass Sports, Inc. (Edina,
MN)
|
Family
ID: |
22408231 |
Appl.
No.: |
05/123,360 |
Filed: |
March 11, 1971 |
Current U.S.
Class: |
12/142P;
36/117.6 |
Current CPC
Class: |
A43B
5/0405 (20130101) |
Current International
Class: |
A43B
5/04 (20060101); A43d 009/00 (); A43b 000/00 () |
Field of
Search: |
;36/2.5AL,2.5R,71
;12/142R,142P |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lawson; Patrick D.
Claims
What is claimed is:
1. A method of fitting a ski boot to a foot utilizing a filling of
relatively dry discrete particles comprising the steps of providing
a boot and placing a foot form inside said boot, providing a pad
member having a cavity adjacent at least portions of said foot
form, providing an inlet opening to said pad cavity, mixing and
suspending said discrete particles in a stream of air and injecting
said air and particle suspension in a flowing stream into said pad
until said pad is filled.
2. The process of claim 1 further characterized in that said pad
cavity is inflated with air prior to fluid introducing the air and
particle mixture into said pad.
3. The process of claim 1 further characterized in that said pad
cavity is defined by a wall having a resilient layer adjacent said
foot form, and said process comprises adjusting the pressure of the
air in the air suspension material to attain the desired compaction
pressure of material in said pad against said resilient layer.
4. The process of claim 1 comprising the step of separating said
pad in said boot into separate cavities and individually filling
each cavity sequentially.
5. The process of claim 1 comprising the step of separating said
pad member into separated cavity means adjacent the front portions
of said foot form and adjacent the heel portions of said foot form,
and injecting the air and material mixture into the cavity means
adjacent said heel at a higher pressure then in the cavity means
adjacent the front portions of said foot form.
6. The process of claim 5 including the further step of providing
an air and particle mixing chamber having an outlet, and feeding
selected amounts of discrete particle material into said mixing
chamber at a rate to permit the air and particle suspension to
escape through said outlet.
7. A method of fitting a boot such as a ski boot to the foot of a
wearer, said boot including a shell providing a pad member having a
cavity, placing a foot form inside said boot with said pad member
between the shell and said foot form, inflating said pad member
cavity to cause the pad to assume the shape of portions of the foot
form, and filling said cavity with padding material carried in an
air suspension.
8. A method of fitting an athletic boot to the foot of a wearer
utilizing a normally substantially nonflowable material comprising
a particulate material composed of discrete particles ranging
generally up to 0.025 inches in major dimension comprising the
steps of providing a boot having a wall, providing pad means having
a cavity between the boot wall and the foot form, suspending said
particulate material in a gaseous fluid stream, injecting
particulate material in the fluid stream into the pad cavity and
permitting the fluid to escape from the pad until the pad cavity is
filled the desired amount with the particulate material.
9. A method of fitting a ski boot to a wearer utilizing a filling
of discrete particles coated with a lubricant and which retains the
discrete particle characteristic in use comprising the steps of
providing a boot and placing a foot form to be fitted inside said
boot, providing a pad member having a cavity adjacent at least
portions of said form, providing an inlet opening to said pad
cavity, mixing and suspending said discrete particles in a stream
of gaseous fluid to cause the discrete particles to be suspended to
flow with the fluid, and injecting said fluid and suspended
particles into said pad, and permitting air to escape from the
cavity until said pad is filled with discrete particles a desired
amount.
10. The process of claim 8 further characterized in that said pad
cavity is defined by a wall having a resilient layer adjacent said
foot, and said process comprises adjusting the pressure of the
fluid carrying the suspended particles to attain the desired
compaction pressure of particles in said pad against said resilient
layer.
11. The process of claim 8 comprising the step of separating said
pad means into separated cavity means adjacent the front portions
of said foot form and adjacent the heel portions of said foot form,
and injecting the fluid and suspended particles into the cavity
means adjacent said heel at a higher pressure than in the cavity
means adjacent the front portions of said foot.
12. A method of fitting a boot, such as a ski boot, on a foot of a
wearer using a pad filled with discrete particles comprising the
steps of providing a boot shell, providing pad means defining a pad
chamber on the interior of the shell, placing a foot in the boot,
providing a quantity of discrete particles which form the pad
filling in suspension in an air stream, injecting the air stream
and suspended discrete particles into the pad chamber and
permitting the air to escape from the pad chamber at a rate such
that the pad is initially inflated and the chamber subsequently
fills with discrete particles in a pad shape generally conforming
to the configuration of the space the pad occupies.
13. A method of fitting a boot such as a ski boot to the foot of a
wearer, said boot including a shell providing a flexible wall
member forming an interior cavity, placing a foot form inside said
boot with said flexible wall member between the shell and said foot
form, inflating said interior cavity under fluid pressure to cause
portions of the flexible wall to be forced toward the foot form
under pressure to exert a pressure on portions of the foot form,
and subsequently filling said interior cavity with padding material
while permitting the inflating fluid to escape from the interior
cavity.
14. The method of claim 13 wherein the flexible wall forms a pad
member and including the step of regulating the fluid pressure to a
desired level prior to inflating said interior cavity.
15. The method of claim 14 including the step of filling the pad
with padding material with the padding material exerting a pressure
on the foot substantially equal to the fluid pressure of pad
inflation.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention has relation to a fitting process for boots
and the like which must fit closely to irregular objects such as
human feet.
2. Prior Art
In the prior art of ski boots, properly fitting the boots to the
feet has been a problem. A very suitable material which will
conform to the human foot has been advanced, and the material per
se, as well as its use as a pad for human feet, is shown in U.S.
Pat. No. 3,407,406. The previous method of fitting the boots to the
foot was to utilize lining filled with a quantity of conformable
material, and then finish the fitting process by adding small
pillows filled with conformable material in back of the lining.
Other designers have attempted to obtain close fitting ski boots by
using an "on the foot" foaming process. Typical applications of
this foaming process are shown in U.S. Pat. Nos. 3,377,721 to
Johnson, and 3,325,919 issued to Robinson.
While initially the boots where the material is foamed in place on
the foot have a good fit, the foam in many instances will tend to
take a set, or even in certain instances tend to crumble slightly.
In addition, the person's foot will change in size and shape with
the passage of time so that the wearer may find that the foot
starts to loosen up in the boot. Additional pairs of socks will
have to be put on, and then the boot will likely be too tight.
Further, once a boot has been custom fit to a foot, by the foaming
process, so that the foam is molded in place, the fit cannot be
changed short of shaving away or cutting out portions of the foam
already in place or adding socks. This of course tends to be
unsatisfactory.
The padding material and pads shown in U.S. Pat. No. 3,407,406 thus
are better suited for holding a foot firmly in a boot because the
shape of the material can be changed, and pad material can be added
or removed. However, the time spent in order to accomplish a close
fit using small filler pillows has been quite high in certain
instances. The material will retain its shape, once formed, until
it is disturbed by external forces.
One of the problems facing the conformable material shown in U.S.
Pat. No. 3,407,406 is that it does not flow like a liquid when it
is subjected to pressure unless it is more or less extruded out.
Further, the material itself tends to remain in its position in
which it is formed so that it cannot be fed by gravity into a
pad.
The present device relates to a method of utilizing the conformable
material shown in U.S. Pat. No. 3,407,406 in a quick, custom
fitting of footwear to the foot.
SUMMARY OF THE INVENTION
The present invention relates to a method of custom fitting
footwear utilizing a conformable material made up of discrete
particles. More particularly, the method of fitting the footwear to
the foot utilizes a material made up of discrete particles coated
with a liquid or lubricating coating so that the material will
retain its shape when the foot is removed, but which, when
fluidized as shown, will be injectable into empty pads in a boot in
which a foot is positioned.
Further, the process includes the idea of separating the pads in
the boot into compartments, and providing means for fluidizing the
discrete material at different pressures so that a different amount
of packing force can be achieved in each of the separate sections
of the boot for different degrees of firmness for fitting on the
foot.
The pads in the boot may be lined with a compressible foam on the
walls against the foot to exert compression force against the foot
when the foot is in place. The amount of force against the foot can
be selected by selecting the pressure with which the pads are
filled.
The device for making the air particle suspension includes a
housing that has a frontal area adjacent a discharge opening in
which air is introduced to turbulently mix the discrete particles
covered with the liquid coating. Material is fed into this
turbulent mixing area and is discharged when fluidized, into the
pads being filled.
The device utilizes air under relatively low pressure, and low air
volume is all that is necessary for fitting the boot. The device
permits inflating the pads against the foot of a wearer before they
are filled, to get a good fit.
The fitting process is rapid, and gets an extremely close fit
utilizing the conformable material that will move slightly if
changes in the foot configuration occur, or which can be removed
very quickly if the person fitting the boot decides that they do
not want to have the boots, or if they decide they want a
completely different fit.
Further, the conformable material can be manually removed from the
pad in small quantities, or added into the pad if final adjustments
are necessary after the boots have been used for a short time.
Once injected, the material particles again cluster or adhere
together to retain their shape until disturbed by external
force.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 of the side elevational view of a ski boot in place on a
foot wherein pads for the boot are being fitted according to the
process of the present invention;
FIG. 2 is a side elevational view of the boot of FIG. 1 as viewed
from the opposite side thereof;
FIG. 3 is a perspective view showing the interior of the boot of
FIG. 1;
FIG. 4 is a sectional view taken as on line 4--4 in FIG. 2 showing
a pad filled and closed;
FIG. 5 is a sectional view taken substantially the same as FIG. 4
showing the filling process being carried out; and
FIG. 6 is a fragmentary perspective view showing schematically the
process of removing material from a boot pad using an aspirator
action with a filter compartment container for the removed
material.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a ski boot illustrated generally at 10 is of
the type having a lower portion 11 that holds the foot, and a cuff
portion 12 for supporting the lower leg and which is pivotally
mounted about an axis 13 with suitable brackets 14 with respect to
the lower portion. Foot access into the boot is achieved through
the use of a door 15 that is hingedly attached as at 16 to the rear
portions of the boot. The lower leg encircling cuff portion 12 thus
comprises two sections, 12A and 12B, one section being on the door,
and one being on the main part of the boot, and the lower foot
receiving portion 11 also comprises two sections namely the main
portion 11A of the main part of the boot and a door portion
11B.
Suitable fastening means comprising encircling cables 17 and 18,
held together with overcenter clamps 19 and 20, the cables encircle
the cuff and the lower portion of the boot to hold the door closed,
and a cover member 21 is carried by the cables to enclose the open
area between the cuff portion and the lower portion of the boot. In
addition, a suitable clamping strap assembly over the instep area
illustrated generally at 23 can be provided to hold the door
tightly closed over the instep. The cuff portion 12 is made to fit
around the lower leg 25 of a wearer and when the door portion 11B
is held closed, the foot is held inside the lower part of the boot.
The ski boot has a sole portion 26 with means 27 for attaching it
to a ski binding to hold it on a ski.
Boots of the general type illustrated are shown in greater detail
in U.S. Pat. Nos. 3,529,368 and 3,543,421, as well as others.
The boot shell making up the lower portion 11 of the boot as shown
is of a rigid fiber glass reinforced plastic, or similar rigid
material, and once the boot is locked closed it is vitally
important that a close fit between the shell and the foot in the
boot is achieved. The padding on the inside of the boot needs
therefor to be conformed to the foot configuration, and to give it
adequate support for withstanding the pressures or forces that are
encountered during the skiing. Other ski boots conventionally
constructed of plastic or leather also benefit from a firm,
comfortable fit and the method described herein can be used with
all types of boots.
As shown, the interior of the cuff 12 is lined with suitable
padding illustrated generally at 28 that can be of the type shown
in U.S. Pat. No. 3,407,406, and the cuff can be padded in the same
manner as that shown in U.S. Pat. No. 3,374,561. The fit around the
cuff portion is not as difficult to obtain as the fit on the lower
part of the boot.
The lower door portion 11B, has a pad assembly illustrated
generally at 30 mounted thereon. The pads are made with a backing
member and a cover member fastened or stitched together to form a
container or packet, as will be explained in detail. The pad
assembly 30 includes a frontal pad 31 that extends along the side
of the foot and up partially over the instep of the boot, and the
pad forms a pocket separated by stitching 32 from a door heel pad
33. As shown, the door heel pad 33 forms a pocket or cavity and is
stitched at 34 to leave an isolated area along the ankle bone of a
wearer which is not filled.
On the lower main part 11A of the boot, there is a pad assembly
which includes a frontal pad 35 along the outside surface of the
boot and extends upwardly along the instep. This main boot frontal
pad forms a pocket which is separated by stitching 36 from a main
boot heel pad 37 that also forms a pocket or cavity and stitching
38 isolates the ankle bone area from the heel pad pocket. The heel
pad extends along the side of the foot in the heel area and extends
upwardly at the rear part of the foot above the heel of the
foot.
The pad assemblys in this particular instance are constructed
identically, except for peripheral shape, and referring
specifically to FIG. 4 as a typical cross section each of the pads
includes a backing member 40, and an inner liner wall member 41
that is stitched or otherwise fastened around the pad periphery as
at 42 to the backing member. The inner liner wall 41 is the wall
that goes against the foot in each of the pads, and is of soft
leather or other suitable material that is not harsh on the foot.
In FIG. 4 pad pocket 37 is illustrated, which is the pad near the
heel on the main part of the boot. The inner wall 41 which is next
to the foot in the frontal pads may be lined on its inner side with
a layer of foam 43 (see FIG. 3) that is of suitable density to
provide a relatively compressible layer next adjacent the foot. The
heel pads generally will omit the foam layer and the cover wall 41
will compress against the foot.
As typically shown in FIG. 4, each of the pads is positioned
against the wall 44 of the boot, which is made up of fiberglass
reinforced plastic or the like, and a ferrule 45 is passed through
an opening in the backing member 40 for each of the respective pad
pockets 31, 33, 35, and 37. The ferrule is fitted through a
provided opening in the boot wall 44 associated with that pad.
Ferrule 45 has a head on the interior of the pad and is flared
outwardly at its outer end to hold the backing member 40 snuggly
against the interior of the wall 44 of the boot. The ferrules 45
each have a threaded interior opening. A screw 46 is threaded in
the opening and fits downwardly over the cover member 21 and seals
the opening through the ferrule 45. Thus there is an opening to the
interior pocket chamber of each of the pads 31, 33, 35 and 37
formed between the interior surface of the backing member 40 and
the interior surface of the cover wall 41 in each of the pads, and
in the frontal pads, of course, the foam layer 43 is on the
interior of the wall 41.
As shown, in FIG. 2, there are filler screws 46 adjacent the top
portions over the instep on each side of the foot, (see FIG. 3 as
well for the screw on the door portion), and there is a filler
screw 46 on each side of the boot at the rear portions. There is
one filling opening to each of the pad sections, 31, 33, 35 and
37.
In order to have the material that will conform to the foot, and
support the foot under skiing loads, as well as a material which
can be moved slightly to accomodate changes in the foot, the
material described in U.S. Pat. No. 3,407,406 has been found to be
suitable. Generally this material comprises discrete particles each
of which is covered with a thin coating of a liquid lubricating
material, preferably in the form of an oil or grease that has an
insert base. The mixture is relatively dry when mixed in the proper
portions and the particles will tend to cluster or clump together
because of the coating. The desired portions are those disclosed in
U.S. Pat. No. 3,407,406, and the desired particulate material is
the small microspheres which are small (usually less than 0.005
inch diameter), and are coated with a silicone base oil or grease
in the ratio of 20 to 1 by weight (20 parts of the spheres to one
part of the grease). This material is, when mixed as shown, a
substantially incompressible, but light in weight, because the
spheres are hollow. The material will retain its shape as formed
from external pressures, and will not shift or flow, but can be
kneaded or worked into desired shapes. It is very difficult to move
the material under pressure, such as when trying to extrude it. The
previous fitting process has utilized small pillows of the material
which were placed in behind the pads in the boot, and as the foot
worked inside the boot, the material would gradually conform to the
foot and hold it securely. This did take time, however.
Handling this material has proved to be a real problem, until the
device shown in FIG. 1 was advanced. The material mixture made up
of these coated spheres, which are preferably the small particles,
(but can be larger particles as well) is illustrated generally at
50 inside the cylindrical (circular cross section) barrel 51 of a
ratcheting type gun, similar to a caulking gun. The material
particles can be selected to be larger and the method will also
work. The barrel 51 as shown has an interior plunger 52 mounted
onto a ratcheting shaft 53 operated with a ratcheting trigger 54 at
one end of the gun. The barrel 51 can be filled with the material
50 in any desired manner, but for convenience, cartridges of the
material 50 can be prepacked, or prefilled and then the material
drawn out of the cartridge by removing the end 59 of the gun and
pulling the shaft 53 rearwardly so that the plunger 52 will suck
the material from the cartridge directly into the barrel. Because
the material itself does not tend to flow, other forms of filling
are possible, but are more time consuming than using cartridges of
the material.
The barrel 51 has an air inlet opening in one side wall thereof and
a petcock valve 55, which can be turned on or off, and is
threadably mounted in the opening and opens into the interior of
the barrel adjacent the outlet end thereof. A suitable line 56 is
attached to the inlet side of the petcock 55, and leads from a
pressure regulator 57, that in turn is attached to a compressor or
air pressure source 58.
The outlet end of the barrel 51 has the removable cap 59 mounted
thereon, which can be twist locked on or off as desired, and this
cap 59 has an outlet opening of small diameter, with a valve 62
mounted in the opening to control flow out through the opening in
the cap 59. The valve 62 has a lever 63 for operating it, and the
outlet side of the valve is connected to a small diameter tube 64.
Tube 64 is made to fit inside an adapter 65 that is threaded into a
selected one of the ferrules 45 when a pad is to be filled, and
after the screw 46 is removed from that particular ferrule. In FIG.
1, for example, the adapter 65 is threaded into the opening leading
to the door heel pad section 33 adjacent the heel of the foot in
the boot and on the door of the boot.
The fitting process is initiated by placing the boot on the foot to
be fitted. The lower end of tongue 70 is usually lifted up over the
top of the lower part of the boot and the door 15 closed. The strap
23 is latched, but usually the other clamps are left loose with
cover 21 open so air can escape from inside the boot.
Prior to any mixing of material and passage of the fluidized
material, air can be discharged through the valves and the end of
barrel 51, through tube 64 to inflate the pad that is being filled,
for example the pad 37. The pad inner liner actually billows out
under air pressure and the interior liner member 51 will contact
the foot under air pressure. The air will discharge out through the
stitching 42 around the periphery of the pad, and also some of the
air will pass out through the member 41, which is usually leather
and porous, so that the air actually blows the pad against the
foot. Some means for permitting air to escape from the pads must be
provided and preferably the air will discharge around the
periphery.
The particulate material is moved forwardly toward the end cap 59
by ratcheting the trigger and plunger into a turbulent mixing zone
that forms automatically inside the barrel 51. This turbulent
mixing zone is indicated at 67 and is filled with swirling air and
suspended small particles which make up the material 50. The mixing
zone self forms as the air tends to rotate around the cylindrical
barrel 51 when the air comes in through the regulator 57 and line
56. With the valves 62 and 55 open, this mixing takes place as long
as the material 50 is moved by the plunger 52 to the area adjacent
the mixing zone 67 until the material is broken up into the
individual particles and is fluidized or in other words the
particles are suspended in the fluid with a sufficiently low
particle to air ratio to permit passage of the fluidized material
through the outlet opening in the cap 59, through the valve 62 and
into the tube 64. The air under pressure then moves this air
suspended material through the adapter 65, through the ferrule 45
and into the interior of the connected pad. As the fluidized
material is blown into the pad it will migrate toward the seams or
stitching or wherever air is being discharged. The material will
blow into the farthest corner of the pad first, filling up these
areas and compressing the foam layer 43 of the particular pad being
filled under a force directly proportional to the air pressure
delivered from the regulator 57. The trigger 54 on the ratchet
plunger is operated as desired to move the material 50 into the
mixing zone 67. The mixing of air and particles will take place,
and the additional fluidized material will be discharged out
through the tube 64 into the pad. The pad will be filled at the
desired pressure. As the pad fills, material fills in the
irregularities against the foot and when the pad fills the material
starts to build up around the interior end of the adapter 65. When
the build up occurs no additional material can be blown in, and
then the tube 64 starts to fill up. This is an indication that the
pad is full. The tube 64 is of a clear plastic material, and is a
small tube preferably about one-fourth of an inch in diameter.
However the tube size will be selected depending on the size of the
particles being blown, but the one-fourth inch diameter tube works
well with the microballoon particles. The valves can be turned off,
the tube 64 and the adapter 65 removed and the plug 46
replaced.
The frontal pads 31 and 35 are filled first. These pads do not have
to be filled with such a high holding pressure, and generally the
regulator 57 will be set at a relatively low air pressure, for
example 25 lbs per square inch this will compress the foam layer 43
in the frontal pads.
Once the pad 35, for example, has been filled, the material will
back up into the tube 64 indicating that the pad is filled, the
adapter will be removed and the screw 46 for that pad inserted.
Then the next screw 46 on the frontal pad 31 on the door side of
the boot will be removed, the adapter 65 inserted and this pad
filled under the same air pressure. The stitching 36, and 32 in the
respective pad assemblys prevents material from being blown into
heel pad areas 33 and 37.
The heel areas will then be filled and in this instance the
pressure regulator 57 is increased in pressure output to
approximately 40 lbs per square inch, and the pads are filled as
before, by first inflating them with air, and then moving the
material 50 into the turbulent mixing zone 67 to fluidize it and
send it out through the valve 62 and tube 64 into the pad. The
increased air pressure will cause the material to compress the wall
41 against the flesh in the heel areas under a greater pressure,
and thus a greater pressure will be exerted against the heel area
for more secure heel hold down. One of the problems in fitting ski
boots of course is to get a sufficient amount of padding just above
the heel proper at the rear part of the leg to the rear of the
ankle bone where there are depressions or sockets in the foot. The
present process inflates the pad so that the interior of the pad
will conform into this area, and the filling with the fluidized
particles forces the wall 41 to compress against these areas at a
higher pressure to insure adequate heel hold down. The wall 41 is
somewhat resilient and also the flesh compresses slightly.
Then when both sides of the heel area have been filled, the boot is
fitted properly and can be used. If desired, some material can be
removed from the pads by merely pressing on the interior surface of
the pad and forcing material in small quantities out through the
opening ferrule. Likewise, small amounts of material can be forced
into the pad after the foot is removed by taking out the screw 46
and pushing columns of the material through the openings of the
ferrule.
The particles can be removed from the pads by aspirating action. As
shown in FIG. 6, the adapter 65 can be inserted into the opening of
the pad to be emptied and air under pressure is flowing through
main line 73. This line goes past an aspirator member 74 to form a
suction or vacuum on line 75 under well known physical principles.
The air is discharged through a tube 76 into a porous bag 77 which
can be of the suitable construction such as a vacuum cleaner bag,
so that air can pass out through the walls of the bag, and padding
material will remain in the bag and not pass through these walls.
The aspirator action through tube 75 will pull the particles right
out of the pad in a reverse action, and this can be aided by
jiggling the pads to loosen the particles and get them into the air
flow. In this manner boots that were fitted to one foot can be
refitted to a different foot if desired, or if the person's foot
changes drastically a substantial amount of material can be removed
in this manner and new material 50 inserted as previously
described.
The method has been particularly described in connection with
footwear, where fitting problems are greatest. However, the method
also may be used generally for filling pads that are between a
rigid or semirigid member and an irregular shaped portion of the
body where close fit is desired. Further, the provision of means
for fluidizing the discrete particles covered with the lubricating
material can be used for transferring the material from one place
to another, or for filling pads.
The coating on the particles will tend to make them cluster
together inside the pad before the particles pass out through the
seams with the discharging air. If a small amount of particles do
pass through the seams, the material can be brushed off easily. The
air discharge openings can be selected to be small enough in size
to prevent any substantial loss of particles during filling.
The microsphere particles, coated with the liquid coating will
quite easily slide along the barrel 51 as the material is fed by
plunger 52 and the ratchet drive. The material is very difficult to
extrude into a smaller cross section, or smaller opening,
however.
In the claims, the term microspheres is to be interpreted as in
U.S. Pat. No. 3,407,406. The discrete particles may be of size to
provide the necessary padding effect without too harsh a feel.
Usually this is under one-fourth inch in major dimension.
Microspheres range from 0.0002 inch in diameter to 0.025 inch. The
preferred microballoons, which are the hollow phenolic resin
spheres range from 0.0002 inch to 0.005 inch in diameter.
The fluidizing process components are selected to obtain the proper
volume and velocity of air in relation to the particle size. Also,
the diameter of tube 64 and the opening in the ferrules 45 are
selected to suit the particle size used. The foam layers in the
pads can be foam commonly used for padding and selected to give the
firmness of hold desired.
* * * * *