U.S. patent application number 09/792156 was filed with the patent office on 2001-08-23 for dryer-ironer with heated ironing cylinder and heat carrying fluid.
Invention is credited to Dermy, Claude, Grandpierre, Cyril Marc Michel, Maziere, Andre.
Application Number | 20010015025 09/792156 |
Document ID | / |
Family ID | 8847286 |
Filed Date | 2001-08-23 |
United States Patent
Application |
20010015025 |
Kind Code |
A1 |
Grandpierre, Cyril Marc Michel ;
et al. |
August 23, 2001 |
Dryer-ironer with heated ironing cylinder and heat carrying
fluid
Abstract
In a dryer-ironer, the cylinder (10) of which is heated from
inside, the cylinder is built so as to define between two
concentric walls (18, 22), a closed annular chamber (26) containing
a heat carrying fluid. The fluid is set into motion through a
stirring system integrated into the cylinder, so that establishment
of a uniform temperature may be provided along its entire length.
The stirring system may be passive (blades) or active (pump).
Inventors: |
Grandpierre, Cyril Marc Michel;
(Troyes, FR) ; Maziere, Andre; (Saint Parres Les
Vaudes, FR) ; Dermy, Claude; (St. Thibault,
FR) |
Correspondence
Address: |
PEARNE & GORDON LLP
526 SUPERIOR AVENUE EAST
SUITE 1200
CLEVELAND
OH
44114-1484
US
|
Family ID: |
8847286 |
Appl. No.: |
09/792156 |
Filed: |
February 22, 2001 |
Current U.S.
Class: |
38/44 |
Current CPC
Class: |
D06F 67/02 20130101 |
Class at
Publication: |
38/44 |
International
Class: |
D06F 061/00; D06F
067/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 2000 |
FR |
00 02231 |
Claims
1. A dryer-ironer comprising an ironing cylinder provided with a
cylindrical wall and able to rotate around an axis of said wall,
and heating means placed inside the cylinder, for heating the
cylindrical wall, wherein the cylinder further comprises an
external wall, encircling the cylindrical wall in order to delimit
with the latter a closed annular chamber, filled with a heat
carrying fluid, and stirring means able to generate circulation of
the heat carrying fluid inside said chamber, said stirring means
comprising units placed in the annular chamber.
2. A dryer-ironer according to claim 1, wherein said units are
passive units placed in the annular chamber so as to generate
circulation of the heat carrying fluid when the cylinder rotates
about its axis.
3. A dryer-ironer according to claim 2, wherein said passive units
comprise blades borne by the cylindrical wall, wherein said blades
are inclined with respect to the axis of the cylinder.
4. A dryer-ironer according to claim 3, wherein the blades have a
height substantially equal to the thickness of the annular chamber,
so as to serve as a support for the external wall.
5. A dryer-ironer according to claim 2, wherein the he at carrying
fluid is a fluid which only fills a portion of the annular chamber,
wherein said liquid is topped with a neutral gas.
6. A dryer-ironer according to claim 5, wherein stabilizers are
placed in the liquid in order to oppose rotation of the latter when
the cylinder rotates about its axis.
7. A dryer-ironer according to claim 1, wherein said units are
partitions in a staggered configuration within the annular chamber,
in order to delimit between the cylindrical wall and the external
wall, a path for reciprocating motion, substantially parallel to
the axis of the cylinder, wherein the stirring means further
comprise driving means for causing the heat carrying fluid to
circulate along said path.
8. A dryer-ironer according to claim 7, wherein the partitions have
a height substantially equal to the thickness of the annular
chamber, so as to serve as a support for the external wall.
9. A dryer-ironer according to claim 1, wherein the external wall
has a smaller thickness than the one of the cylindrical wall.
10. A dryer-ironer according to claim 1, wherein the external wall
is made out of stainless steel and the cylindrical wall out of
ordinary steel.
11. A dryer-ironer according to claim 1, wherein at least an end of
the external wall is encircled by a discharge space externally
delimited by a fixed case, wherein a valve is mounted in said end
of the external wall in order to enable the annular chamber to be
in communication with the discharge space, in the event of an
overpressure in said chamber.
12. A dryer-ironer according to claim 11, wherein a duct with
gravity flow connects the discharge space to a tank.
Description
DESCRIPTION
[0001] 1. Technical Field
[0002] The invention relates to a dryer-ironer wherein laundry is
ironed between a heated ironing cylinder and one or more endless
straps which are in contact with the cylinder on a portion of its
circumference.
[0003] The dryer-ironer according to the invention may be used in
all cases where relatively large amounts of laundry must be ironed
frequently. Thus and uniquely as an example, such a machine may be
used in hospital institutions, nursing homes, hotels, lodging
houses, restaurants, etc.
[0004] 2. State of the Art
[0005] In dryers-ironers with a heated ironing cylinder, the pieces
of laundry are inserted one after the other between a rotating
cylinder, with a generally horizontal axis, and one or more endless
straps which are in contact with the cylinder along its entire
length and a portion of its circumference. Heating means placed
inside the cylinder bring the latter's metal wall up to a
determined temperature, selected in order to provide effective
ironing of the laundry.
[0006] The heating means which are placed inside the ironing
cylinder are of different types, depending on the machines. Hence,
these heating means may comprise a gas manifold, heating
resistances, infrared heating devices, etc.
[0007] In existing dryers-ironers, the ironing cylinder has a
relatively thick cylindrical wall. This wall is generally made of
steel. It has relatively large thermal inertia, because of its
thickness.
[0008] In a dryer-ironer of this type, the passing of a piece of
laundry with a given width between the ironing cylinder and the
endless straps has the effect of lowering the temperature of the
cylinder in the concerned area. On the contrary, the areas of the
cylinder not concerned by the passing of the piece of laundry and
which continue to be heated, experience a rise in their
temperature. Considering the relatively large thermal inertia of
the ironing cylinder, a piece of laundry immediately ironed after
the previous one will therefore encounter either an insufficiently
heated area of the cylinder or on the contrary an overheated area
of the cylinder, depending on whether it is inserted at the same
place than the previous piece of laundry or at a different place.
In the first case, the second piece of laundry is badly ironed. On
the contrary, in the second case, the piece of laundry may be
burnt. Actually, the thermal gradient even increases if several
pieces of laundry are successively inserted substantially in the
same area.
[0009] Dryers-ironers with a heated ironing cylinder are also
known, wherein heating of the cylinder is provided by a heat
carrying fluid such as oil. In this case, the heat carrying fluid
is heated in a boiler located outside the machine, before being fed
into the cylinder by a pump also placed outside the machine.
[0010] Such a machine does not have the drawbacks of dryers-ironers
for which the ironing cylinder is heated by heating means
integrated into this cylinder. Actually, permanent circulation of
the heat carrying fluid is able to provide efficient diffusion of
the heat over the entire length of the cylinder and consequently,
to impart to the latter, a substantially uniform temperature over
its entire length even after the passing of a piece of laundry in
the machine.
[0011] On the other hand, the dryers-ironers of this type have the
drawbacks of requiring heavy, external, expensive and complex
facilities.
[0012] This drawback sometimes causes the users to simultaneously
feed several machines by a unique circuit integrating one single
boiler and one single pump. However, the cost of such a facility
remains substantially greater than that of a dryer-ironer for which
the ironing cylinder is heated by an integrated heating system.
DESCRIPTION OF THE INVENTION
[0013] Specifically, the object of the invention is a dryer-ironer
with a heated ironing cylinder, having both the advantages of
simplicity of machines with integrated heating in the cylinder and
the advantages of uniform diffusion of heat over the entire length
of the cylinder of machines for which the cylinder is heated by a
heat carrying fluid.
[0014] According to the invention, this result is obtained by means
of a dryer-ironer comprising an ironing cylinder provided with a
cylindrical wall and able to rotate about an axis of said wall, and
heating means placed inside the cylinder, in order to heat the
cylindrical wall, characterized in that the cylinder further
comprises an external wall, encircling the cylindrical wall in
order to delimit with the latter an closed annular chamber, filled
with a heat carrying fluid, and stirring means able to generate a
circulation of the heat carrying fluid within said chamber, wherein
said stirring means comprise units placed in the annular
chamber.
[0015] In this machine, the ironing cylinder is heated from the
inside by traditional heating means, which may be of any type, as
in the existing machines for which the cylinder is heated from the
inside. Moreover, by using an ironing cylinder with a double wall,
by filling the closed annular chamber thus defined by a heat
carrying fluid and by using means for stirring this fluid,
integrated into the cylinder, an efficient diffusion of heat on the
entire length of the cylinder may be provided without substantially
increasing the complexity and the cost of the machine.
[0016] According to a first embodiment of the invention, the
aforementioned units are passive units, placed in the annular
chamber in order to generate circulation of the heat carrying fluid
when the cylinder is rotating around its axis.
[0017] These passive units comprise, for example, blades supported
by the cylindrical wall, wherein these blades are inclined with
respect to the cylinder's axis, so as to generate motion of the
heat carrying fluid, parallel to the axis of the cylinder, upon the
latter's rotation.
[0018] Preferably, the blades have a height substantially equal to
the thickness of the annular chamber, in order to also serve as
support for the external wall of the cylinder.
[0019] In the first embodiment of the invention, the heat carrying
fluid is a liquid which only fills a portion of the annular
chamber. This liquid is topped by a neutral gas, so that the
annular chamber also acts as an expansion vessel.
[0020] Advantageously, stabilizers such as balls are then placed in
the liquid in order to oppose a rotation of the latter with the
cylinder when the latter rotates around its axis.
[0021] According to a second embodiment of the invention, the
aforementioned units are partitions in a staggered configuration
within the annular chamber, in order to delimit between the
cylindrical wall and the external wall of the cylinder, a path for
reciprocating motion, substantially parallel to the axis of the
cylinder. Now, the stirring means further comprise driving means
such as a pump in order to cause circulation of the heat carrying
fluid along this path.
[0022] In both embodiments of the invention, the external wall
preferably has a thickness lower than that of the cylindrical
wall.
[0023] Moreover, the external wall of the cylinder is
advantageously made of stainless steel and the cylindrical wall of
ordinary steel.
[0024] Preferably, at least one end of the external wall is
encircled by a discharge space, externally delimited by a fixed
case. A valve is then mounted in the aforementioned end of the
external wall so as to allow the annular chamber to communicate
with the discharge space, in the event of overpressure in said
chamber.
[0025] Advantageously, a duct connects the discharge space to a
tank, in order to provide flow by gravity of the heat carrying
fluid.
BRIEF DESCRIPTION OF DRAWINGS
[0026] Different embodiments of the invention will now be described
as non-limiting examples with reference to the appended drawings,
wherein:
[0027] FIG. 1 is a sectional view which very schematically
illustrates a dryer-ironer according to the invention;
[0028] FIG. 2 is a partial longitudinal sectional view
schematically illustrating the ironing cylinder of the machine of
FIG. 1 and its associated components;
[0029] FIG. 3 is a partial sectional view comparable to FIG. 2,
illustrating a first embodiment of the invention, wherein the
ironing cylinder is provided with stirring means of the passive
type;
[0030] FIG. 4 is a sectional view of the ironing cylinder
illustrated if FIG. 3; and
[0031] FIG. 5 is a perspective view, illustrating a second
embodiment of the invention, wherein the ironing cylinder is
provided with stirring means of the active type, wherein the
external wall of the cylinder has deliberately been omitted in
order to facilitate the understanding.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] As illustrated in FIG. 1 very schematically, the
dryer-ironer according to the invention comprises an ironing
cylinder 10 as well as one or more endless straps 12 which are in
contact with cylinder 10 on its entire length and on the greater
part of its periphery. This type of machine is well known to one
skilled in the art, so that only the characteristics required for a
good understanding of the invention will be described.
[0033] The ironing cylinder 10 is supported by a fixed frame (not
shown) so that it may rotate freely around a substantially
horizontal axis 14.
[0034] The endless straps 12 are supported and guided by rollers 16
borne by the chassis of the machine. The axes of rotation of the
rollers 16 are parallel to the axis 14 of the ironing cylinder 10.
Any of the rollers 16 may be driven into rotation by a geared motor
(not shown) in order to be able to provide motion of the endless
straps 12 in the direction of the arrows in FIG. 1. This motion has
the consequence of causing the ironing cylinder 10 to rotate in the
same direction and at the same speed.
[0035] As schematically illustrated at 18 in FIG. 1, the ironing
cylinder 10 is internally equipped with heating means of any known
type, able to bring the cylinder to a selected temperature in order
to provide efficient ironing of the laundry. These heating means 18
may be any heating means such as electric resistances, a gas
manifold, an infrared heating device, etc. without departing from
the scope of the invention.
[0036] In order to provide ironing, the pieces of laundry are
inserted, one after the other, between the ironing cylinder 10 and
the endless straps 12, in the higher portion of the machine. They
are then fed between the cylinder and the endless straps so that
they come out in the lower portion of the machine.
[0037] According to the invention, the ironing cylinder 10 has an
original structure which will now be described with reference to
FIG. 2.
[0038] As illustrated in this figure, the ironing cylinder 10
comprises a cylindrical wall 20, centered on axis 14 and made of a
metal such as ordinary steel. The thickness of the cylindrical wall
20 is selected in order to provide the cylinder with good
mechanical strength, without virtually any deformation, during the
ironing. For example, this thickness varies between 4 mm and 6 mm
according to the size of the cylinder. As schematically
illustrated, heating means 18 are placed inside the cylindrical
wall 20.
[0039] The cylindrical wall 20 is externally lined, over virtually
its entire length, by a cylindrical external wall 22, also centered
on axis 14. The external wall 22 is made of stainless steel and it
has a thickness substantially lower than that of the cylindrical
wall 20. More specifically, the thickness of the cylindrical wall
20 is at least twice that of the external wall 22, whereby the
latter may vary for example, between 1.5 mm and 2 mm depending on
the size of the ironing cylinder.
[0040] The external wall 22 is mounted concentrically and at a
distance from the cylindrical wall 20, for example by means of two
welded rings 24 close to the ends of the cylindrical wall 20 and on
which are welded the ends of external wall 22.
[0041] A closed annular chamber 26 with uniform thickness, which is
at least partially filled with a heat carrying fluid, is thus
delimited between the cylindrical wall 20 and the external wall
22.
[0042] As described in detail later on, the ironing cylinder 10 is
also equipped with integrated stirring means, designed for
providing circulation of the heat carrying fluid contained in the
closed annular chamber 26, when the ironing cylinder 10 rotates
around its axis 14. More specifically, the stirring means have the
function of causing the heat carrying fluid to circulate both in
parallel to axis 14 of the cylinder, in order to homogenize the
temperature, and between walls 20 and 22, in order to transfer heat
released by the heating means 18 to the external wall 22.
[0043] As also schematically illustrated in FIG. 2, at least one of
the ends of the external wall 22 of the ironing cylinder 10 is
encircled by a discharge space 28, delimited inwardly by said
external wall 22 and outwardly and laterally, by a fixed case 30.
Sealing units such as revolving joints 31 borne by fixed case 30
ensure water tightness of the discharge space 28.
[0044] A valve 32, mounted on the end of the external wall 22
encircled by the discharge space 28, enables the annular chamber to
be connected with said discharge space, notably when the pressure
within the chamber 26 exceeds a predetermined threshold.
[0045] The bottom of the discharge space 28 communicates with a
tank 34 through a duct 36. This duct 36 is laid out in order to
enable the heat carrying fluid collected in the discharge space 28
to flow by gravity into tank 34.
[0046] According to a first embodiment of the invention, and as
illustrated in FIGS. 3 and 4, the stirring means for the heat
carrying fluid inside the annular chamber 26 may notably be of the
passive type.
[0047] In this case, the stirring means comprise passive units such
as blades 38 placed in the annular chamber 26, in order to generate
the desired circulation of heat carrying fluid when the cylinder
rotates around its axis 14. More specifically, the blades 38 are
positioned in order to bring the heat carrying fluid from the ends
of the annular chamber 26, back into a central region of the
latter. For this purpose, if the cylinder is considered to be
formed of two abutting sections, the blades 38 may notably assume
the shape of spirals wound in one direction on a first of these
sections and wound in the other direction on the other section,
whereby the direction of the spirals is such that the heat carrying
fluid is brought back from the ends towards the center when the
ironing cylinder 10 is rotating about its axis 14.
[0048] In practice, the blades 38 are fixed on the cylindrical wall
20, for example by welding, and they have a height substantially
equal to the thickness of the annular chamber 26, for example this
thickness is of about 5 mm. Thus the blades 38 also serve as a
support for the external wall 22, which usually has relatively
reduced thickness, as seen earlier, with respect to that of the
cylindrical wall 20 of cylinder 10.
[0049] With this layout, a satisfactory geometrical shape may be
maintained for the external wall 22, which is directly used for
ironing the laundry when the machine is in operation.
[0050] It is to be noted that passive units, materialized by blades
38 in FIG. 3, may assume substantially different shapes, without
departing from the scope of the invention. Thus, the spiral blades
38 may be replaced with substantially planar blade sections in
order to reduce the manufacturing costs for the machine.
[0051] The heat carrying fluid contained in annular chamber 26
usually consists of a liquid such as oil capable of providing
efficient heat transfer between cylindrical wall 20 and external
wall 22, under conditions of temperature for ironing. Such heat
carrying liquids are well known to one skilled in the art and will
therefore not be described.
[0052] In the first embodiment of the invention, and as illustrated
in FIG. 4 in particular, the heat carrying liquid 40 only partially
fills the annular chamber 26. In this case, the upper portion of
the annular chamber 26 is filled with a neutral gas. Chamber 26
then acts as an expansion vessel.
[0053] It is desirable to prevent the heat carrying fluid 40 from
being driven into rotation by blades 38 and walls 20 and 22 of the
cylinder 10 during rotation of the latter. Actually, this would
reduce the stirring of the liquid and consequently the achievement
of a substantially uniform temperature over the entire length of
the external wall 22 of the cylinder. For this purpose, the
placement of stabilizers such as balls 42 within liquid 40 proves
to be advantageous.
[0054] In a second embodiment of the invention, illustrated in FIG.
5, active stirring means are used for moving the heat carrying
fluid in the annular chamber 26 provided between the cylindrical
wall 20 and the external wall 22 of the cylinder. These active
stirring means enable the heat carrying fluid to be moved
regardless of the rotation of the cylinder.
[0055] The active stirring means now comprise partitions 44a, 44b,
44c in a staggered configuration inside the annular chamber 26, so
as to delimit between the cylindrical wall 20 and the external wall
22 of cylinder 10, a path for reciprocating motion, substantially
in a parallel orientation with respect to the axis 14 of the
cylinder. The active stirring means also comprise driving means,
such as a pump 46, mounted on the cylinder in order to cause the
heat carrying fluid to circulate along the path delimited by
partitions 44a, 44b, 44c.
[0056] More specifically, partitions 44a, 44b, 44c delimiting the
aforementioned path are fixed on the cylindrical wall 20 and extend
over a height substantially equal to the thickness of the annular
chamber 26, so that they also serve as a support for the external
wall 22, like the blades 38 in the first embodiment of the
invention.
[0057] As illustrated more specifically in FIG. 5, the
aforementioned partitions comprise a circumferential partition 44a,
closely placed to one of the rings 24, in order to delimit with the
latter, an annular channel 48. Two rectilinear partitions 44b, 44c
parallel to axis 14 of the cylinder and located in diametrically
opposite positions, extend over the entire length of the cylinder
between both rings 24. Finally, a certain number of rectilinear
partitions 44d, also parallel to axis 14, are regularly distributed
over the entire circumference of the cylinder, between the
circumferential partition 44a and ring 24 which is the furthest
away from this partition, on both sides of the rectilinear
partitions 44b and 44c. The rectilinear partitions 44b, 44c and 44d
thereby delimit axial channels 50 between each other.
[0058] In addition, the circumferential partition 44a is
interrupted between both rectilinear partitions 44d which are the
closest to rectilinear partition 44c, so that the axial channels 50
adjacent to the latter, are in communication with the annular
channel 48.
[0059] Moreover, one out of two of the rectilinear partitions 44d
is in turn, interrupted close to ring 24, the furthest away from
the circumferential partition 44a and close to said circumferential
partition. Rectilinear partition 44b is also interrupted close to
ring 24, the furthest away from the circumferential partition 44a.
More specifically, the layout is such that both rectilinear
partitions 44d, the closest to rectilinear partition 44b, are
interrupted close to the circumferential partition 44a, and both
rectilinear partitions 44d, the closest to rectilinear partition
44c, are interrupted close to ring 24 the furthest away from the
circumferential partition 44a. The adjacent axial channels 50 thus
communicate with each other at one end and at the other end of the
cylinder, alternately. In this way, a path for reciprocating motion
is delimited for the heat carrying fluid, parallel to the axis of
cylinder 10.
[0060] Pump 46 is borne by cylinder 10 and connected to the annular
channel 48, on both sides of the rectilinear partition 44b, through
suction 51 and discharge 52 ducts.
[0061] With the layout which has just been described, circulation
of the cooling fluid may be established along the path delimited by
the various partitions 44, as indicated by the arrows in FIG. 5. A
reciprocating movement of the fluid is thus established, parallel
to axis 14 of cylinder 10, over the entire periphery of the
latter.
[0062] In both described embodiments, the dryer-ironer has a
relatively simple and not very expensive structure. In particular,
it should be noted that the cylindrical wall 20, which is not in
contact with the laundry to be ironed, may be made of ordinary
steel. Therefore, the amount of stainless steel may be reduced as
compared with an existing machine, because the external wall 22 has
a lesser thickness.
[0063] Moreover and essentially, with the presence of the heat
carrying fluid between both walls of the cylinder and by causing
this heat carrying fluid to circulate through passive or active
stirring means which equip the cylinder, the temperature of the
external wall 22 in contact with the laundry may be made equal
during the whole ironing period. The quality of ironing is thus
improved very substantially as compared to dryers-ironers existing
today with an ironing cylinder heated from the inside.
[0064] Of course, the machine may undergo many alterations, without
departing from the scope of the invention. In particular, the
stirring means for setting the heat carrying fluid into motion
between both walls of the cylinder may assume shapes different from
those which have been described.
* * * * *