The present invention generally relates to an ironing roller with a heating device which is applicable in the field of laundry machinery as an ironing roller in an ironing-drying machine, and more particularly to an ironing roller provided with coaxial annular chambers for the circulation of a heat carrying fluid and heating means for heating said fluid inside one of said chambers.
The use of a roller provided with an inner annular chamber which is at least partly filled with a hot heat carrying fluid or through which a hot heat carrying fluid can circulate to heat an external cylindrical wall of the roller, which roller provides a suitable ironing surface to make contact with the articles to be ironed, is known in the art in the field of laundry machinery. The problem to be solved is how to distribute the hot heat carrying fluid inside the chamber along the roller to ensure a uniform heating of the external cylindrical wall all along the roller.
U.S. Pat. No. 4,418,486, belonging to the public domain, discloses an ironing roller with a heating device comprising two concentric cylindrical walls arranged to rotate together about a common longitudinal axis. The external cylindrical wall provides a suitable ironing surface to make contact with the articles to be ironed, and an annular chamber in communication with an inlet at a first end of the roller and with an outlet at a second end of the roller is formed between the external cylindrical wall and the inner cylindrical wall, such that the chamber forms a passage through which a heat carrying fluid heated by an external heating device can pass. Helical fins or blades are arranged in the chamber with a single rotation direction to propel the heat carrying fluid inside the chamber from said inlet to said outlet as a result of the rotation of the roller. An external circuit, to which an impulse pump is coupled, is arranged to propel the return heat carrying fluid from the outlet to the inlet of the chamber.
The mentioned U.S. Pat. No. 4,418,486 teaches how to circulate the heat carrying fluid inside the chamber from the inlet to the outlet and how to return the heat carrying fluid from the outlet to the inlet passing through heating means and an external pump. A drawback of this construction is the need to have considerable equipment outside the roller, formed by a circuit, heating means, an expansion tank, one or more pumps, etc., as well as rotary joints to connect the conduits of the external circuit to the inlet and outlet of the chamber, which joints are arranged axially through pivot joints at each end of the roller.
U.S. Pat. No. 4,677,773 describes a rotary flatwork ironer comprising a roller formed with a double wall providing a closed annular chamber for a fluid, means for rotatably supporting the roller with respect to a horizontal axis, a fluid inlet and a fluid outlet at opposite ends of the chamber, heating means arranged in a stationary manner inside the roller to heat the fluid inside the chamber, a flow circulation system to make the fluid circulate from said outlet to said inlet passing through a rotating joint and an external circuit including a pump, a cooling tank and an expansion tank, and temperature control means arranged in a part of the circulation system outside the roller and adapted to detect the temperature of the fluid and to start and stop the heating means in response to the detected fluid temperature.
Patent EP-A-1130152 discloses a drying ironing machine provided with an ironing roller with a heating device using a heat carrying fluid. The ironing roller is provided with a cylindrical wall and is suitable to rotate about an axis of said cylindrical wall. Inside the roller there are arranged conventional heating means such as those described in the mentioned U.S. Pat. No. 4,677,773 to heat the cylindrical wall. The roller further comprises an external wall surrounding the cylindrical wall in order to delimit with the latter a closed annular chamber, which is partially filled with a heat carrying fluid. The roller further comprises stirring means for stirring the fluid including members placed in said annular chamber and suitable for generating circulation of the heat carrying fluid inside the chamber according to the teachings disclosed by the aforementioned U.S. Pat. No. 4,418,486. The mentioned external wall provides an ironing surface. According to a first embodiment (FIG. 3 of the mentioned patent), said members are passive members in the form of helical blades borne by the cylindrical wall and arranged inclined with respect to the axis of the roller to generate circulation of the heat carrying fluid when the roller rotates about its axis. In two opposite halves of the roller, the helical blades have opposite rotation directions to propel the heat carrying fluid in opposite directions. According to a second embodiment, (FIG. 5 of the mentioned patent), the members are partitions arranged in a stepped manner in the annular chamber in order to delimit, between the cylindrical wall and the external wall, a zigzag back and forth path which is considerably parallel to the axis of the roller, and the stirring means further comprise a pump on the roller to make the heat carrying fluid circulate according to said path
The heating means of the roller described in the mentioned patent EP-A-1130152 dispense with any external equipment. However, a drawback of the first embodiment is that the mentioned helical blades do not ensure uniform distribution of the heat carrying fluid along the roller due to the fact the return circulation is carried out, after the collision of opposite fluid streams, mixed with the propelling circulation of the blades. If the blades propel the fluid in opposite directions towards the center of the roller during rotation, the fluid tends to accumulate in the central area of the roller. If on the other hand, the blades propel the fluid in opposite directions towards the ends of the roller, the fluid will tend to accumulate in the areas close to the ends of the roller. A drawback of the second embodiment is the need to incorporate an impulse pump on the roller, the proposed winding configuration of the fluid distribution circuit, which can be expensive to carry out, and the need of rotary electrical connections for the connecting cables for connecting the pump to an external power supply source.
An objective of the present invention is to provide a new ironing roller in which, in a preferred embodiment, means for propelling fluid inside an annular chamber as described in U.S. Pat. No. 4,418,486 are used, but providing a second annular chamber, internally or externally coaxial with the first chamber, such that the circulation of the heat carrying fluid takes place by continuously passing from one of said two chambers to the other, which chambers fulfill a heat uptake function (that chamber facing the heat source) and a heat transfer function (that chamber adjacent to the surface of the roller), respectively.
To that end, an ironing roller is proposed, comprising a first cylindrical wall and a second cylindrical wall having a different diameter, which are concentric and arranged to rotate together about a common longitudinal axis, a first annular chamber being delimited between said first and second cylindrical walls in communication with one or more inlets defined at a first end and at least one outlet at a second end, such that said annular chamber forms a passage through which a heat carrying fluid circulates, said heat carrying fluid being heated by heating means located inside the ironing roller, and a return circuit being provided external to said first chamber to lead the heat carrying fluid from the outlet to the inlet of the annular chamber. According to the invention, a second annular chamber which is adjacent and coaxial with the first annular chamber is provided, this second annular chamber being arranged on either side of the first annular chamber, i.e. the larger diameter of the first chamber can be equal to or less than the smaller diameter of the second chamber, thereby the second chamber would be in a part of the roller that is more external than the first chamber, or the smaller diameter of the first chamber can be equal to or greater than the larger diameter of the second chamber, thereby the second chamber would be in a part of the roller that is more internal than the first chamber. These two annular chambers are intercommunicated such that the heat carrying fluid can continuously circulate from one of the annular chambers to the other, said return circuit external to the first annular chamber being carried out through the second annular chamber. One of the mentioned first or second annular chambers carries out a heat uptake function and the other of the mentioned first or second annular chambers carries out a heat transfer function, transferring heat to the external wall of the roller.
According to the principles of the invention, two or more intercommunicated annular chambers in the mentioned arrangement can be used, providing fluid circulation therethrough which will be carried out by means of helical fin or blade propelling means, active when the roller rotates, or by pump means such as those described in the mentioned background documents.
The communication way between the chambers can be diverse, and it is generally carried out between the end areas of each chamber and through the inside of the roller, or externally to it next to the respective ends of the roller.
In a particular embodiment, it has been foreseen that the second annular chamber adopts the form of a coil located inside the first annular chamber and arranged to rotate together with the first and second cylindrical walls about said longitudinal axis, in which case the second annular chamber in the form of a coil carries out said heat uptake function and the first annular chamber carries out said heat transfer function. The ends of the coil are connected to the ends of the first annular chamber which is delimited by the ironing cylinder. Two or more suitably displaced or offset coils can optionally be provided.
The previous and other features and advantages will be more fully understood from the following detailed description of several embodiments with reference to the attached drawings, in which:
The same alphanumeric references have been used to designate identical or equivalent elements in the different embodiments described below.
With reference first to
Conventional heating means (not shown) are arranged inside the ironing roller 10, which means are adapted to heat the first cylindrical wall 1, and the heat carrying fluid which is located in the first annular chamber 4 is heated by direct contact with the first cylindrical wall 1. Blades 7a are arranged in the first annular chamber 4, which blades are inclined with respect to the mentioned longitudinal axis E of the ironing roller 10 to propel the heat carrying fluid inside the first annular chamber 4 from said inlet 5 to said outlet 6. The flow of heat carrying fluid leaving the first annular chamber 4 through the outlet 6 enters the second annular chamber 8 and circulates in an opposite direction therealong up to the opposite end, where it again enters the first annular chamber 4 through the inlet 5. The third cylindrical wall 3 is heated by direct contact with the heat carrying fluid circulating through the second annular chamber 8 from the outlet 6 to the inlet 5, and the third cylindrical wall 3 has an external ironing surface 9 adapted to make contact with the articles to be ironed. The first annular chamber 4 thus carries out a heat uptake function for uptaking the heat coming from the heating means located inside the roller and the second annular chamber 8 carries out a heat transfer function for transferring heat to the articles to be ironed. The rotation of the ironing roller 10 and the continuous circulation of the heat carrying fluid along the first and second annular chambers 4, 8 ensure uniform distribution of heat through the entire third cylindrical wall 3.
The first embodiment of
Alternative constructions for the ironing roller 10 will occur to a person skilled in the art without departing from the scope of the present invention. For example, the blades 7a can alternatively comprise only one or more than two helical blades, or a plurality of short inclined blades distributed inside the first cylindrical chamber 4, or the helical blades can be continuous or interrupted. Alternatively, the first and second ends 2a, 2b of the second intermediate cylindrical wall 2 can be respectively separate from said first and second side walls 11, 12 in order to provide the inlet 5 and the outlet 6, in which case the blades 7a would be fixed to the first cylindrical wall 1 and the second cylindrical wall 2 would be held in place by the blades 7a.
Second and third embodiments for the ironing roller 10 of the present invention are shown in
In the second embodiment shown in
In the third embodiment shown in
In relation to
A heat carrying fluid completely or partially fills the first and second annular chambers 4, 8, and a pump 17 is connected to the second conduit 16 to propel the heat carrying fluid from the inlet 5 to the outlet 6 through the first chamber 4 and from the inlet 5a to the outlet 6a through the second chamber 8. The first and second conduits 15, 16 and said pump 17 are arranged to rotate together with the first, second and third cylindrical walls 1, 2, 3 about the longitudinal axis E. Heating means (not shown) are arranged inside the ironing roller 10 to heat the first cylindrical wall 1 and indirectly the heat carrying fluid inside the first cylindrical chamber 4. The third cylindrical wall 3 is heated by direct contact with heat carrying fluid circulating through the second annular chamber 8, and the third cylindrical wall 3 has an external ironing surface 9 adapted to make contact with the articles to be ironed. The first annular chamber 4 thus carries out the heat uptake function and the second annular chamber 8 carries out the heat transfer function.
The pump 17 could alternatively be connected to the first conduit 15 instead of the second conduit 16 with an equivalent result. With the construction shown in
Heating means (not shown) are arranged inside the ironing roller 10 of
In all the embodiments, inlet 5 generally includes one or more openings located in, or adjacent to, a first end of the first annular chamber 4 and in communication with an outlet of the second annular chamber 8 including one or more openings arranged in, or adjacent to, a first end thereof, and said outlet 6 includes one or more openings located in, or adjacent to, a second end of the first annular chamber 4 and in communication with an inlet of the second annular chamber 8 including one or more openings arranged in, or adjacent to, a second end thereof, the first ends of the first and second annular chambers 4, 8 being contiguous and opposite to the respective second ends. This constriction ensures that the heated heat carrying fluid reaches both ends of the annular chambers carrying out the heat uptake and heat transfer functions.
A person skilled in the art will be able to introduce modifications and changes in the embodiments shown and described above without departing from the scope of the present invention as defined in the attached claims.
Number | Date | Country | Kind |
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P200601625 | Jun 2006 | ES | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/ES07/00294 | 5/22/2007 | WO | 00 | 5/7/2009 |