U.S. patent number 3,637,194 [Application Number 04/887,236] was granted by the patent office on 1972-01-25 for humidifier.
This patent grant is currently assigned to Berns Air King Corporation. Invention is credited to Martin Harris, James A. Swimmer.
United States Patent |
3,637,194 |
Swimmer , et al. |
January 25, 1972 |
HUMIDIFIER
Abstract
A humidifier comprises a housing formed from prefinished metal
sheets in such a manner as to provide a water reservoir, an
inclined filter pad carried by a water trough, an impeller disposed
below the high point of the filter pad and consisting of a hub
carrying a pair of axially spaced platelike bodies, each of the
bodies having two semicircular water-throwing edges of different
radii, a ring carried by the impeller and disposed partly in the
water reservoir, a two-speed motor for rotating the impeller, and a
combined shutoff and indicator apparatus which functions to show
the amount of water left in the reservoir and to turn off the motor
when the water level drops below a predetermined value.
Inventors: |
Swimmer; James A. (Highland
Park, IL), Harris; Martin (Chicago, IL) |
Assignee: |
Berns Air King Corporation
(Chicago, IL)
|
Family
ID: |
25390733 |
Appl.
No.: |
04/887,236 |
Filed: |
December 22, 1969 |
Current U.S.
Class: |
261/29; 261/26;
261/92; 261/100 |
Current CPC
Class: |
F24F
6/04 (20130101) |
Current International
Class: |
F24F
6/02 (20060101); F24F 6/04 (20060101); B01f
003/04 () |
Field of
Search: |
;261/92,80,90,29,100 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Miles; Tim R.
Claims
What is claimed is:
1. In a humidifier that utilized a porous, air-permeable, liquid
receiving member, a rotatable impeller for throwing water under
centrifugal force onto the liquid receiving member, and a
continuous ring carried on and rotated by the impeller for
transferring water continuously from a liquid reservoir to the
impeller, the improved impeller comprising a hub and a pair of
axially spaced platelike bodies carried by said hub, each of the
bodies having a first semicircular water-throwing edge defined by a
first radius with respect to said hub and a second semicircular
water-throwing edge defined by a second radius different from said
first radius, and the pair of bodies being arranged on said hub
with the similar portions of the two bodies arranged diametrically
of each other relative to the axis of rotation of the impeller.
2. An impeller as in claim 1 wherein the portions of the surfaces
of the spaced bodies that face each other and are adjacent the hub
are conically shaped and closely adjacent so as to be adapted to
drivingly and supportingly engage the continuous ring and to
maintain said ring spaced from the hub.
3. The arrangement as in claim 2 in combination with a ring whose
cross section includes inclined walls that are adapted to engage
with the said conical-shaped portions of the spaced bodies and to
substantially conform therewith.
4. An impeller as in claim 1 wherein the facing surfaces of the
spaced bodies include an inner frustoconical portion at a first
acute angle to a vertical plane transverse to the axis of rotation
of the impeller, and an outer frustoconical portion inclined at a
greater acute angle to said vertical plane.
5. An impeller as in claim 1 wherein the hub and plate members are
integrally molded of a substantially rigid plastic material and
provides smooth surfaces on the sides of the plate members that
face each other.
Description
It is an important object of the present invention to provide a
humidifier which is capable of delivering humidified air at two
different rates.
Another object is to provide a humidifier that is exceptionally
quiet during operation.
Still another object is to provide a humidifier comprising a single
motor that drives both an impeller which distributes water onto a
filter pad and a fan blade which blows air through the pad.
In connection with the foregoing object, it is another object to
provide the impeller with two platelike bodies, each consisting of
a pair of semicircular water-throwing edges, to minimize the amount
of water dropping into the reservoir and water droplets being
propelled through the filter pad.
Yet another object is to provide a housing for a humidifier, which
consists of prefinished metal sheets formed into a watertight
reservoir without spot welding.
A further object of the present invention is to provide a frame for
supporting the filter pad in a humidifier, constructed to prevent
excess water from dropping into the humidifier's reservoir.
In connection with the foregoing object, it is another object to
support the filter pad in a trough that causes excess water to
gravitate on the sidewalls as opposed to free falling into the
humidifier's reservoir.
A still further object is to provide a combined shutoff and
indicator apparatus that shows how much water is in the
humidifier's reservoir and shuts off the humidifier when the water
level drops below a certain value.
A yet further object is to provide a housing for a humidifier,
which does not require sealing around fasteners.
With the foregoing and other objects in view which will appear as
the description proceeds, the invention consists of certain novel
features and construction, arrangement, and a combination of parts
hereinafter fully described, illustrated in the accompanying
drawings and particularly pointed out in the appended claims, it
being understood that various changes in the form, proportions,
size, and minor details of the structure and the method may be made
without departing from the spirit or sacrificing any of the
advantages of the invention.
For the purpose of facilitating an understanding of the invention,
there has been illustrated in the accompanying drawings a preferred
embodiment thereof, from an inspection of which, and considered in
connection with the following description, the invention's mode of
construction, operation, and many of its advantages should be
readily understood and appreciated.
Referring to the drawings in which the same characters of reference
are employed to indicate corresponding or similar parts throughout
the several figures of the drawings:
FIG. 1 is a perspective view of a humidifier embodying the
principles of the present invention;
FIG. 2 is a top plan view on an enlarged scale of the humidifier
shown in FIG. 1;
FIG. 3 is an enlarged view in vertical section of the humidifier
shown in FIG. 2, taken along the lines 3--3 thereof;
FIG. 4 is an enlarged view in vertical section of the humidifier in
FIG. 2, along the lines 4--4 thereof, with portions of the back
wall broken away;
FIG. 4A is an enlarged fragmentary view of one of the casters and
its connection to the humidifier;
FIG. 5 is an enlarged view of the frame and filter pad;
FIG. 6 is a greatly enlarged sectional view of a fragmentary
portion of one of the walls making up the humidifier housing;
FIG. 7 is a fragmentary bottom plan view on an enlarged scale of a
caster mounted on the humidifier housing;
FIG. 8 is a side elevational view on an enlarged scale of the
impeller;
FIG. 9 is a view in vertical section of the impeller of FIG. 8,
taken along the lines 9--9 thereof;
FIG. 10 is a view in lateral section of the ring shown in FIG. 9,
taken along the lines 10--10 thereof; and
FIG. 11 is an exploded view of the humidifier.
Referring now to the drawings, and more particularly to FIGS. 1 to
4 and 11, thereof, there is shown a humidifier 20 embodying the
principles of the present invention. The humidifier 20 comprises a
housing 30 formed from two pieces of prefinished sheet metal, one
of which is generally U-shaped to form a front wall 31 and a pair
of sidewalls 32. The bottom of the front wall 31 is bent about
90.degree. to form an inwardly directed bottom flange 33;
similarly, the bottoms of the sidewalls 32 are respectively bent
about 90.degree. to form inwardly directed flanges 34. The rear
portions of the sidewalls 32 are bent about 90.degree. toward one
another to form inwardly directed side flanges 35; similarly, the
top of the front wall 31 and the tops of the sidewalls 32 are bent
about 90.degree. to from an inwardly directed top flange 36, which
flange carries an offset ledge 36a.
Referring to FIG. 6, the sheeting bent to form the parts 31-36a
consists of a metal sheet 37 carrying on one side thereof a
decorative vinyl coating 38 and on the other side thereof a
waterproof coating 39. The waterproof coating 39 surrounds the
interior of the housing 30, as will be described, and the
decorative vinyl coating 38, which, for example, may have a
wood-grain appearance, covers at least the front wall 31, the
sidewalls 32, and the top flange 36, so that the outside of the
humidifier 20 presents an attractive appearance.
The housing 30 also comprises a second metal sheet which may also
be prefinished on either or both sides as shown in FIG. 6. This
second sheet is bent to form a bottom wall 40 and an upstanding
backwall 41, the backwall 41 having a height much shorter than the
height of the front wall 31. The front of the bottom wall 40 is
bent about 90.degree. to form a downwardly directed front flange 42
which, in turn, carries an inturned flange 42a disposed generally
parallel to the bottom wall 40. The sides of the bottom wall 40 are
bent about 90.degree. to form a pair of downwardly directed side
flanges 43 which, in turn, respectively carry inturned flanges 43a
disposed generally parallel to the bottom wall 40. The sides of the
backwall 41 are bent about 90.degree. to form a pair of outwardly
directed side flanges 44 which, in turn, respectively carry
inturned flanges 44a disposed substantially parallel to the back
wall 41. The top of the backwall 41 is bent inwardly about
90.degree. so as to extend parallel to the bottom wall 40.
In connecting together the two pieces of bent, prefinished sheet
metal, the inturned flange 42a is placed on top of the bottom
flange 33, so that the front flange 42 is spaced rearwardly of the
front wall 31. Also, the inturned flanges 43a are respectively
placed on the side flanges 35, so that the side flanges 43 are
spaced respectively from the sidewalls 32. Finally, the inturned
flanges 44a are respectively placed against the side flanges 35, so
that the side flanges 44 are respectively spaced from the sidewalls
32. Sheet metal screws 47 are then used to connect the flanges 34
and 43a, the flanges 33 and 42a, and the flanges 35 and 44a, in
such a manner that the screw heads are on the outside of the
housing. The space between the flange 42 and the front wall 31, the
spaces between the side flanges 43 and the sidewalls 32, and the
spaces between the side flanges 44 and the sidewalls 32 are filled
with a sealant 46. There are also provided reinforcement plates 48
to strengthen the bend in the prefinished sheet metal between the
walls 40 and 41. The five joints thus described are watertight and
define a reservoir 49.
As explained previously, the sheeting used to form at least the
parts 31-36a is prefinished with a decorative coating 39 on the
"outside" and a waterproof coating 39 on the "inside". It would be
undesirable to weld together the parts of such a construction since
to spot-weld, a means to expose bare metal is necessary, and the
heat created during welding would damage one or both of the
coatings. In addition, it is desirable, from an economic
standpoint, that the housing be formed so as to constitute the
reservoir, rather than provide a separate reservoir. Finally, it is
advantageous not to have any screws extending into the water
reservoir, which are difficult to seal and might eventually result
in leaks. The novel construction of the housing 30 described above
accomplishes these objectives, as may be seen in FIG. 4a which
depicts in cross section one of the five joints, that connects the
two pieces of prefinished sheet metal. By virtue of this
construction, none of the screws 47 extends into the interior of
the housing 30, thereby to reduce substantially the chances of a
leak occurring. The interior of the reservoir 49 is completely
waterproof by virtue of the waterproof coating 39 on the interior
of each wall and by virtue of the sealant 46 in each of the
joints.
Supporting the housing 30 is a set of four casters 60. As is most
clearly shown in FIG. 11, each caster 60 includes a mounting plate
61 having a pair of openings 62 and a pair of openings 63. The
mounting of the two casters toward the back of the housing 30 is
best shown in FIGS. 4A and 11. Sheet metal screws 66 pass through
the openings 63 and through the juxtaposed flanges 43a and 34.
There is provided a spacer 64 having a pair of fingers 65 that fit
into the other pair of openings 62, the opposing edge of the spacer
64 bearing against the bottom wall 40 so as securely to mount and
support each of the rear casters 60. The mounting of the front
casters 60 is most clearly shown in FIG. 7, wherein it can be seen
that sheet metal screws 66 pass through all four openings, through
the juxtaposed flanges 33 and 42a and through the juxtaposed
flanges 34 and 43a.
As is best seen in FIGS. 3, 4, and 11, the humidifier 20 includes a
rear panel 70 having a series of vents 71 generally centrally
therein. Formed in an inwardly directed portion 74 of the rear
panel 70 is a cutout 72 and a curved support 73, the purpose of
which will be explained subsequently. The rear panel 70 is attached
to the upper portion of each of the side flanges 35 by screws or
the like. There is also provided an L-shaped angle iron 80
including an abutment plate 81 and an attachment flange 82 which is
secured to the inwardly directed portion 74 of the rear panel 70.
There is also provided a cover 83 having a slot 84 therein that is
in substantial alignment with the cutout 72 and the support 73 on
the rear panel 70. The cover includes a pair of side flanges 85
that rest on the inwardly directed portion 74 of the rear panel 70.
A ledge 86 is struck from one of the side flanges 85 so as to be
aligned with the offset ledge 36a provided on the front wall 31 and
the sidewalls 32, whereby a substantially continuous ledge is
provided. The inwardly directed portion 74 also carries a
three-position switch 90 and a humidistat 91, the shafts of which
extend through openings in the cover 83 and are attached
respectively to knobs 92 and 93. An indicator light 94 is also
mounted in the inwardly directed portion 74 so as to be viewable
through an opening in the cover 83.
The humidifier 20 further comprises a water trough 100 (see FIG. 3)
including a pair of attachment flanges 101 on either end thereof
which are mounted to the sidewalls 32 of the housing 30. The
interior wall 102 of the water trough 100 is inclined at a
predetermined acute angle with respect to the horizontal. For
reasons to be explained hereinafter, the length of the interior
wall 102 of the trough 100 is very slightly less than the distance
between the sidewalls 32 so as to furnish a slight space between
each end of the interior wall 102 and the adjacent sidewall 32.
There is provided a filter support frame 103 which is generally
rectangular in shape and includes a set of three lips 104 and a
plurality of crossmembers 105. Resting on the frame 103 is a
porous, air-permeable liquid-receiving member or filter pad 108.
The lips 104 maintain the pad 108 in position. Further details of
the frame 103 and the filter pad 108 thereon are shown in FIG. 5
which illustrates each crossmember 105 as having a generally flat
top 106 and a curved bottom 107 for purposes to be explained
presently. One margin of the frame 103 rests in the water trough
100 and has a width such that the opposing margin thereof rests
against the abutment plate 81 at an acute angle with respect to the
horizontal. The parts are so dimensioned that the angle between the
interior wall 102 of the water trough 100 and the horizontal is
less than the angle between the frame 103 and the horizontal, for
purposes to be explained presently.
Disposed directly above the filter pad 108 and supported by the
ledges 36a and 86 is a decorative grill 109. In order to fill the
humidifier 20, the grill 109 is simply lifted off of its supporting
ledge, and the frame 103 and the pad 108 are removed to expose the
reservoir 49.
The humidifier 20 further comprises a combined shutoff and
indicator apparatus 110 shown in FIGS. 4 and 11. The apparatus
includes an L-shaped transparent tube 111, one leg of which rests
on the support 73 of the panel 70 and the other leg of which
extends downwardly through the cutout 72. A pair of stabilizer
brackets 112 and 112a is affixed to the rear panel 70 and has a
hole therein to receive the downwardly extending leg of the tube
111. There is provided an elongated flexible member 113 carrying on
one end thereof an enlarged head 114 and on the other end thereof
an enlarged tail 115. A rigid rod 116 has one end thereof
press-fitted in an opening in the tail 115. The other end of the
rod 116 is bent as shown so as to pass through an opening in a
float 117. A washer 118, followed by a push on fastener 119 holds
the float 117 in place on the rod 116 and provides sufficient
weight to actuate the switch 120 when the water level recedes. The
member 113 is at least partially disposed in the tube 111 and is
adapted to move therein as will be explained.
There is also provided a switch 120 mounted on the rear panel 70 by
a speed nut 122, the switch having a pivotal actuating arm 121. The
switch 120 operates a motor 132. A switch linkage in the form of a
rod 123 has a loop 124 on one end thereof and is attached to the
actuating arm 121 at the other end thereof. The rod 116 is disposed
in the opening of the loop 124. If the member 113 is lowered, the
enlarged tail 115 engages the loop 124 to lower the rod 123 and
consequently lower the arm 121 and thereby open the switch 120.
There is provided an air guide 130 to which is mounted a bracket
131. A two-speed motor 132 is mounted on the bracket 131 and is
also secured to the rear panel 70 by means of nuts and bolts 133,
thereby to mount not only the motor 132 but also the air guide 130.
The motor 132 has a shaft 134 consisting of a larger diameter
portion 135 and a reduced diameter portion 137, the portion 135
carrying a fan blade 136. There is provided a line cord 138 for
connecting the motor to a source of AC power. Mounted on the
reduced diameter portion 137 is an impeller 140 which carries a
ring 170 that is disposed partly in the reservoir 49. The
dimensioning of the parts is such that the impeller 140 is below
the uppermost region of the filter pad 108.
When the motor 132 is energized, the impeller 140 rotates the ring
170 through the water in the reservoir 49. The ring 170 deposits
water on the impeller 140, which then forms the water into a spray
175, striking the uppermost region of the pad 108. The water
gravitates through the pad by virtue of being inclined and also
moves throughout the pad by capillary action, thereby to saturate
the pad. In an operating embodiment, the filter pad 108 was formed
of a polyurethane foam that had 20 pores per square inch. If the
porosity is excessive, the droplets will pass through the pad 108
into the air, whereas, if the porosity is insufficient, the air
will have difficulty passing.
The rotating shaft 134 of the motor 132 also causes the fan blade
136 to rotate so as to draw air from the surrounding area through
the vents 71 in the rear panel 70, through the air guide 131, and
forces the air upwardly through the wetted filter pad 108 so as to
humidify the air. The humidified air passes out of the humidifier
20 through the decorative grill 109.
The excess water in the filter pad 108 drops onto the frame 103 and
runs down the crossmembers 105 thereof into the trough 100. Because
the bottom 107 of each of the crossmembers 105 is rounded, the
quantity of water that will drop into the reservoir 49 is reduced.
It is, of course, undesirable for the water to drop into the
reservoir since that would make the humidifier noisy during
operation thereof. In addition, it should be noted that the frame
103 consists only of crossmembers 105 that run in the direction of
inclination so that water flows therealong into the trough 100.
There are no longitudinally extending members which would increase
the likelihood of water droplets falling directly into the
reservoir.
The fact that the inclination of the frame 103 is greater than the
inclination of the interior wall 102 of the water trough 100
results in a V-shaped space between the wall 102 and the frame 103.
This assures that the water on the frame 103 will flow into the
trough 100 rather than impinge on the longitudinal edge thereof and
then drop into the reservoir 49. Also, the fact that the ends of
the interior wall 102 are spaced slightly from the adjacent
sidewalls 32 of the housing 30 means that the water in the trough
100 will flow into the reservoir 49 as sheets along on the walls 32
as opposed to dropping into the reservoir 49. Each of these factors
contributes to the noise-free operation of the humidifier 20.
The three-position switch 90 is attached to the two-speed motor
132, so that rotating the knob 92 to its first position turns off
the motor 132; rotating it to its second position causes the motor
132 to operate at a low speed; and rotating it to its third
position causes the motor to operate at a high speed. The
humidistat 91, also connected to the motor 132, operates to turn
off the motor 132 when a selected humidity is attained, determined
by the setting of the knob 93.
The combonation shutoff and indicator apparatus 110 comprises a
minimum number of parts, both to turn off the motor 132 when the
water level drops below a predetermined value and to indicate the
quantity of water in the reservoir 49. The water will raise or
lower the float 117, depending upon the water level, so as to move
the enlarged head 114 in the horizontally disposed leg of the tube
111. As is most clearly shown in FIG. 2, the head 114 will point to
the appropriate indicia to indicate the quantity of water in the
reservoir 49. When the water drops below a certain level, the
enlarged tail 115 engages the loop 124 to pull down the actuating
arm 121 of the switch 120, via the rod 123, which turns off the
motor 132. Filling up the reservoir 49 causes the float 117 again
to turn on the motor 132. The indicator light 94 is connected to
the switch 120, so that, when the light is off (or on, if desired),
there is sufficient water in the reservoir 49 to permit the motor
132 to operate, whereas, when the light is on, the water level has
dropped below the requisite minimum value.
Referring now to FIGS. 8 and 9, the details of construction of the
impeller 140 will be described. The impeller 140 includes a hub 141
that has a bore 141a extending therethrough and carries a pair of
axially spaced, platelike bodies 142 and 152. The body 142 has an
inwardly facing surface 143 that is generally conically shaped and
is divided into a central portion 144 and an outer portion 145. The
inwardly facing surface 143 in the central portion 144 is inclined
at a given angle with respect to the axis of rotation of the
impeller 140, whereas the inwardly facing surface 143 of the outer
portion 145 is inclined at a lesser angle with respect to that
axis. The body 142 also has an outwardly facing surface 146 with a
dished-out region 147 formed therein in order to save material.
Along the periphery of about one-half of the body 142 is a beveled
surface 148 that meets the inwardly facing surface 143 to define a
semicircular water-throwing edge 149, having a given radius. Along
the periphery of the other half of the body 142 is a beveled
surface 150 that meets the inwardly facing surface 143 to define a
second semicircular water-throwing edge 151 having a shorter
radius. The other platelike body 152 is precisely the same as the
body 142 and is numbered with corresponding reference numerals plus
a factor of 10. In the interest of brevity, further detailed
description of the platelike body 152 will be omitted.
The semicircular water-throwing edge 159 of the body 152, having
the longer radius, is diametrically opposed in position to the
semicircular water-throwing edge 149 of the other body 142, having
the longer radius. Similarly, the semicircular water-throwing edge
161, having the shorter radius, is diametrically opposed to the
corresponding semicircular water-throwing edge 151 on the body 142,
having the shorter radius. The positioning of the water-throwing
edges at diametrically opposite positions provides for dynamic
balance of the impeller 140. To provide further dynamic balance, it
may be desirable to add some material to the dished-out region 147
where the radius is less, so that the mass of either platelike body
on one side of any diameter thereof equals the mass on the other
side of that diameter. A careful selection of material for the
impeller 140 is important. If it is too soft, the ring 170
"squishes" against it to cause noisy operation of the humidifier;
whereas, if it is too hard, the ring 170 makes a metallic sound
against it, again noisy. In an operating embodiment of the
invention, the impeller 140 was constructed of a synthetic
copolymer of a 60 to 80 durometer hardness rating.
Referring now to FIGS. 3, 9, and 10, the ring 170 is circular and
rigid and has a pair of side surfaces 171 that slope toward one
another towards the center of the ring. The slope of each of the
surfaces 171 is selected to be equal to the slope of the inwardly
facing surfaces 143 and 153 of the central portions 144 and 154.
Accordingly, one side surface 171 will mate with the inwardly
facing surface 143 of the central portion 144, and the other side
surface 171 will mate with the inwardly facing surface 153 of the
central portion 154. The ring 170 has a curved outer surface 172
and a flat annular inner surface 173. The ring 170 is laterally
dimensioned, so that the surface 173 is spaced from the hub 141 to
achieve best support of the ring. Both the ring 170 and the
inwardly facing surfaces 143 and 153 are constructed as carefully
as possible to be smooth and thereby minimize points at which water
can drop from and into the reservoir. It is pointed out that the
amount of contact between the side surfaces 171 and the inwardly
facing surfaces 143 and 153 controls the amount of water that will
be deposited by the ring 170 onto the impeller 140. Thus, the
dimension of the surfaces may be selected to cause the desired
quantity of water to be deposited. Of course, the fact that the
ring 170 is rigid permits it to be constructed to be smooth and
thereby minimize noise. Also, the rigidity of the ring maintains it
in the desired configuration.
The construction of the impeller 140 as described contributes to a
basic objective of the humidifier 20, i.e., to reduce the noise
during operation thereof. If the water-throwing edge had a constant
radius of a value selected to insure that the spray 175 would not
pass through the filter pad 108 when the motor 132 was operating at
its high speed, then the velocity of the spray at the low speed of
the motor 132 would be so slow that much of the spray would drop
into the reservoir 49 and thereby make noise. On the other hand, if
the water-throwing edge of each platelike body had a constant
radius of a value selected to insure that the spray 175 had
sufficient initial velocity at the slower speed of the motor 132 to
reach the filter pad 108, then at the higher speed of the motor 132
the spray would be propelled fast enough undesirably to pass
through the filter pad 108.
The impeller 140 described above strikes a compromise, by reducing
both the quantity of spray 175 capable of passing through the
filter pad 108 and the quantity of spray 175 that drops into the
reservoir 49. Thus, the humidifier 20 operates efficiently to
humidify the air quietly and without dispensing spray at both
speeds of the motor 132. For example, the user, at night, when very
quiet operation is important, positions the knob 92 in its "low"
position to operate the motor 132 in its less noisy, low-speed
condition. On the other hand, when maximum humidification is
desired, the knob 92 is placed in its "high" position to rotate the
fan 136, the impeller 140, the the ring 170 at high speed. Of
course, the humidistat 91, as determined by the setting of the knob
93, will turn off the motor 132 when the desired humidity is
reached, whether the motor is operating at its high speed or its
low speed.
It is believed that the invention, its mode of construction and
assembly, and many of its advantages should be readily understood
from the foregoing without further description, and that it should
also be manifest that, while a preferred embodiment of the
invention has been shown and described for illustrative purposes,
the structural details, nevertheless, are capable of a wide
variation within the purview of the invention as defined in the
appended claims.
* * * * *