FreshPatents.com Logo
stats FreshPatents Stats
n/a views for this patent on FreshPatents.com
Updated: September 07 2014
newTOP 200 Companies filing patents this week


    Free Services  

  • MONITOR KEYWORDS
  • Enter keywords & we'll notify you when a new patent matches your request (weekly update).

  • ORGANIZER
  • Save & organize patents so you can view them later.

  • RSS rss
  • Create custom RSS feeds. Track keywords without receiving email.

  • ARCHIVE
  • View the last few months of your Keyword emails.

  • COMPANY DIRECTORY
  • Patents sorted by company.

Follow us on Twitter
twitter icon@FreshPatents

Method of controlling a rotatable-drum laundry dryer and a rotatable-drum laundry dryer implementing the method

* PDF is temporarily not available for this patent. There was a technical issue with this week's patent images, we are working on getting it resolved. Please check back later. Thank you for your patience.

Title: Method of controlling a rotatable-drum laundry dryer and a rotatable-drum laundry dryer implementing the method.
Abstract: A method is provided for controlling a drying operation of a rotatable-drum laundry dryer (1) having a rotatable drum (3) for loading laundry (5) and at least an electrode sensor (22) for sensing dryness of the laundry (5). The method includes the step of detecting the presence/absence of moist laundry (5) inside the rotatable drum (3) by the electrode sensor (22). If a presence of moist laundry inside the rotatable drum (3) is detected, a drying cycle is started. The dryness of the laundry (5) is sensed during the drying cycle and a cycle time (TD) at which the sensed dryness reaches a preset dryness threshold is measured. If the cycle time (TD) is lower than a preset dryness threshold time (Sm), the drying cycle is continued for a first additional time (D1), and the drying cycle is stopped at the end of the first additional time (D1). ...


Browse recent patents - Brussels, BE
USPTO Applicaton #: #20140115916 - Class: 34282 (USPTO) -


Inventors: Fabio Altinier, Fabio Pasut, Michele Bisaro, Roberto Ragogna

view organizer monitor keywords


The Patent Description & Claims data below is from USPTO Patent Application 20140115916, Method of controlling a rotatable-drum laundry dryer and a rotatable-drum laundry dryer implementing the method.

The present invention relates to a method of controlling a rotatable-drum laundry dryer and a rotatable-drum laundry dryer implementing the method.

Methods of controlling rotatable-drum laundry dryers are known, in which: hot air is fed into the rotatable drum so as to flow over the laundry inside the drum; an electric parameter associated with the laundry moisture is measured by means of an electrode sensor arranged in order to contact with the laundry when drum rotates; the dryness of the laundry is determined according to the measured electric parameter; and the drying cycle is stopped when the measured electric parameter reaches a preset value associated with a prefixed final dryness.

More specifically, laundry dryers are known comprising an electronic control unit which receives a plurality of voltage signals having an amplitude and/or a frequency associated with the electric parameter of the laundry, i.e. impedance or resistance, or conductance, and measured a prefixed number of times; the electronic control unit determines the dryness of the laundry according to the measured voltage signals, and controls the drying cycle according to determined laundry dryness. For example the electrode sensor may be configured to output a voltage signal which is proportional to the dryness of the laundry. Thus, more dried is the laundry, higher is its electric parameter and consequently bigger is the voltage signal outputted from the electrode sensor.

The technical problem of the above-described prior-art laundry dryer is that when contacts between laundry and electrode sensor, during the drying cycle, are very few, an incomplete dryness condition of the laundry may be performed, since the electronic control unit may erroneously conclude (or determine, resolve) that the few number of contacts between the laundry and the electrode corresponds to a dry condition of the laundry.

As a matter of the fact, research by the Applicant shows that when the above control method is performed in a rotary-drum home laundry dryer in which the electrode sensor is arranged outside the drum, i.e. in a position facing the opening in the drum, the frequency with which the laundry contacts the electrode sensor is reduced, or tends towards zero, when, for example, the laundry corresponds to a small load quantity, i.e. a single T-shirt, or when, for example, a “special” kind of laundry (e.g. a pillow), is loaded in the laundry dryer in such a way that it gets stuck inside the drum in such a position that it doesn\'t contact or only rarely contacts the electrode sensor.

In such cases, because the number of contacts laundry-electrode is very few and/or the electric signals outputted from electrode sensor are affected by high electric noise, the electronic control unit determines a high average value and, as a consequence, calculates a high electric parameter (impedance or resistance or conductance), and erroneously associate the latter with a dryness condition. Thus, electronic control unit may incorrectly conclude (or determine, resolve) that an expected drying condition of the laundry has been reached, and it may and stop the drying cycle too early, even if the laundry is still wet.

JP2000229200 discloses a clothes drying machine in which drying operation are controlled in the case of a small amount of laundry into the rotating drum. In particular, the drying machine is configured to start a drying course by measuring the number of contacts between electrode and laundry; to determine whether the laundry is a high load or small load based on the measured number of contacts; and if the determined laundry is a small load, to set the drying cycle period for twenty-five minutes, independently of the moisture of the laundry.

JP6312095 discloses a clothes drying machine which dries laundry independently of the its quantity, by executing the drying operation by a drying time setting timer when a small quantity signal is outputted from a clothes quantity judging device, while executing the drying operation, monitoring the dried state if the small quantity signal is not outputted. In detail, the clothes are agitated, and each time when the clothes come to an electrode which operates as clothes detector, is detected repeatedly. When the clothes detection signal which is detected up to the time-up of a clothes quantity judging timer is less than a standard value, a microcomputer incorporated in a control circuit outputs a small quantity signal from a clothes quantity judging device and forcibly executes the drying operation without monitoring the dried state of the clothes up to the time-up of a drying time setting timer. Under the condition that it is considered that the contact frequency of the clothes with the electrode is high and the reliability of the signal of the electrode is high, the drying operation is executed, judging the degree of dryness by the electrode.

Clothes drying machines disclosed in JP2000229200 and in JP6312095 have the problem that systems starts the drying cycle selected by the user and maintains operating the same in any case for a preset time, even if the drum is empty or the laundry is already dry, causing a useless wastage of electric energy.

It is therefore an object of the present invention to provide a solution designed to obviate one or more problems due to limitations and disadvantages of the related art, and in particular a solution which guarantees the user to control the rotatable-drum laundry dryer in order to assure a uniform laundry dryness, even if the laundry inside of the drum is few and/or is arranged inside the rotatable-drum so that number of contacts with the electrode sensor is very low, and at the same time strongly reducing the wastage of electric energy, in particular in case no laundry or already dry laundry is loaded in the rotatable drum.

According to the present invention, there is provided a method of controlling a drying operation of a rotatable-drum laundry dryer comprising a rotatable drum for loading laundry and at least an electrode sensor for sensing dryness of the laundry. The method comprises: detecting the presence/absence of moist laundry inside the rotatable drum by the electrode sensor; if presence of moist laundry inside the rotatable drum is detected, starting a drying cycle; sensing dryness of the laundry during the drying cycle; measuring a cycle time at which the sensed dryness reaches a preset dryness threshold; if the cycle time is lower than a preset dryness threshold time, continuing the drying cycle for a first additional time, and stopping the drying cycle at the end of the first additional time.

Preferably the first additional time is such that the time elapsed from the beginning of the drying cycle and the stopping of the drying cycle is a preset minimum dryness time.

More preferably the first additional time is set as the difference from the preset minimum dryness time and the cycle time.

Advantageously the method comprises: if the cycle time is not lower than the preset dryness threshold time, continuing the drying cycle for a preset second additional time; and stopping the drying cycle at the end of the second additional time.

Preferably the second additional time is between zero and ten seconds.

Preferably determining the presence/absence of moist laundry inside the rotatable-drum comprises: performing a starting detection phase for a starting detection time; if no moist laundry has been detected during the starting detection time, performing one or more additional detection phases, each of which lasts an additional detection time; if no moist laundry has been detected during the additional detection phase/s, ending operation of rotatable-drum laundry dryer.

Advantageously the additional detection time is lower than the starting detection time.

The invention regards also a rotatable-drum laundry drier comprising: a rotatable drum for loading laundry, a least an electrode sensor for sensing dryness of the laundry; feeding drying air means for feeding drying air into the drum, and rotating means for rotating the drum about an axis of rotation. The rotatable-drum dryer comprises electronic control means configured to: detect presence/absence of moist laundry inside the rotatable drum by the electrode sensor; if presence of moist laundry inside rotatable drum is detected, start a drying cycle; sense dryness of the laundry during the drying cycle; measure a cycle time at which the sensed dryness reaches a preset dryness threshold; if the cycle time is lower than a preset dryness threshold time, continue to perform the drying cycle for a first additional time, and stop the drying cycle at the end of the first additional time.

Advantageously the first additional time is such that the time elapsed from the beginning of the drying cycle and the stopping of the drying cycle is a preset minimum dryness time.

Preferably the first additional time is set as the difference from the preset minimum dryness time and the cycle time.

Opportunely the electronic control means are further configured to: continue to perform the drying cycle for a preset second additional dryness time if the cycle time is not lower than the preset dryness threshold time; and stop the drying cycle at the end of the preset second increased cycle time.

Advantageously the second additional time is between zero and ten seconds.

Preferably the electronic control means are further configured to: perform a starting detection phase for a starting detection time; if no moist laundry has been detected during the starting detection time, perform one or more additional detection phases; and if moist laundry have been detected during the additional detection phase/s, end operation of rotatable-drum laundry drier.

Advantageously each of the one or more additional detection phases lasts an additional detection time lower than the starting detection time.

A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic lateral cross section of a rotatable-drum laundry drier implementing the laundry drying control method according to the present invention;

FIG. 2 shows an inner lateral wall of the FIG. 1 rotatable-drum laundry drier; while

FIG. 3 shows an operation flow chart of the control method implemented according to the present invention.

Number 1 in FIG. 1 indicates as a whole a rotatable-drum laundry dryer comprising an outer casing 2, which preferably rests on the floor on a number of feet.

Casing 2 supports a rotatable laundry drum 3, which defines a drying chamber 4 for laundry 5 and rotates about a preferably, though not necessarily, horizontal axis of rotation 6. In an alternative embodiment not shown, axis of rotation 6 may be vertical or inclined.

Drying chamber 4 has a preferably frontal access opening 7 closable by a door 8 preferably hinged to casing 2.

Drum 3 may be rotated about axis of rotation 6 by an electric motor, schematically represented in FIG. 1 and indicated with reference number 9, is fed with hot air heated by a heating device, schematically represented in FIG. 1 and indicated with reference number 10, and is fed into drum 3 preferably by a fan schematically represented in FIG. 1 and indicated with reference number 11. Fan 11 may preferably, though not necessarily, be driven by electric motor 9 or, in an alternative embodiment (not shown), by an auxiliary electric motor (not shown) independent of electric motor 9.

In the FIG. 1 example, one opened side of the drum 3 of the laundry drier 1 is advantageously associated, in a rotatable and substantially air-tight way, to a perforated inner wall 12 fixed to a lateral wall of casing 2 and through which hot air flows into drum 3; the other opened side of the drum 3 is advantageously associated, in a rotatable and substantially air-tight way, to a flange 13 associated to casing 2 and interposed between door 8 and front access opening 7 of drum 3.

In the FIGS. 1 and 2 example, flange 13 is fixed firmly to casing 2, and is positioned at front access opening 7 so as to project at least partly inside drum 3, so that its inner surface faces the laundry 5 when the latter is loaded into the drum 3.

Heating device 10 may advantageously comprise one or more electric heating components, such as electric resistors (not shown) or, in an alternative embodiment, a heat pump.

In actual use, fan 11 blows a stream of drying air (represented by the white arrows in FIG. 1), produced by heating device 10, preferably through perforated inner wall 12 into drum 3. After contacting laundry 5 inside drum 3, the moisture-laden drying air flows out of drum 3 and it is preferably directed to a condensing device 15, which cools the drying air to condense the moisture inside it. For this purpose, condensing device 15 may be supplied with cold air from outside the drier, and feeds the moisture-free air to fan 11. It should be pointed out that condensing device 15 as described above applies, purely by way of example, to one possible embodiment of the present invention, and may be omitted in the case of an exhaust-type rotatable-drum laundry drier 1 (i.e. in which the hot and moisture-laden drying air from the rotatable laundry drum 3 is expelled directly out of rotatable-drum laundry drier 1).

The rotatable-drum laundry drier 1 also comprises an electronic control system 16, which is configured to control the rotatable-drum laundry drier 1, advantageously on the basis of a drying cycle selected by a user via a user control interface 18.

The electronic control system 16 advantageously comprises an electrode sensor 22 for detecting dryness of the laundry.

According to a preferred embodiment, the electrode sensor 22 is a contact electrode sensor type and comprises two metal plates 23 arranged on the flange 13 in a position facing the inside of the drum 3, for sensing the dryness of laundry by using impedances generated at opposite ends of the metal plates 23 according to moisture content of the laundry 5 when the later is brought into contact with the opposite metal plates 23, and forwards the dryness as a electrical signal, i.e. a voltage signal. Nevertheless, it is obvious that electrical signal outputted by the electrode sensor 22 could be associated, for example, with the resistance and/or conductance of the laundry 5 sensed between the metal plates 23.

Preferably the electrode sensor is configured to generate an oscillating electrical signal and vary the frequency of oscillation of the electrical signal according to the laundry moisture/dryness.

The electronic control system 16 further comprises an electronic control unit 14, which is configured to control the electric motor 9, heating device 10 and/or fan 11 in order to regulate the rotation speed of the drum 3, the temperature and/or the flow rate of hot air entering the drum 3 according to preset temperatures and flow rates specified for the laundry drying cycle selected by the user.

Preferably, selectable laundry cycles may comprise for example, a “cotton laundry drying cycle”, a “synthetic fabric laundry drying cycle”, a “wool laundry drying cycle”, and a “delicate laundry drying cycle”.

The electronic control unit 14 is further configured to: detect the presence/absence of moist laundry 5 inside the rotatable drum 3 by the electrode sensor 22; if presence of moist laundry 5 inside the rotatable drum 3 is detected, start a drying cycle that user selected.



Download full PDF for full patent description/claims.

Advertise on FreshPatents.com - Rates & Info


You can also Monitor Keywords and Search for tracking patents relating to this Method of controlling a rotatable-drum laundry dryer and a rotatable-drum laundry dryer implementing the method patent application.
###
monitor keywords



Keyword Monitor How KEYWORD MONITOR works... a FREE service from FreshPatents
1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored.
3. Each week you receive an email with patent applications related to your keywords.  
Start now! - Receive info on patent apps like Method of controlling a rotatable-drum laundry dryer and a rotatable-drum laundry dryer implementing the method or other areas of interest.
###


Previous Patent Application:
Coat hanger for conveyor belts
Next Patent Application:
Raising apparatus for cleaning portion in cleaning tool and raising method for cleaning portion in cleaning tool
Industry Class:
Communications: directive radio wave systems and devices (e.g., radar, radio navigation)
Thank you for viewing the Method of controlling a rotatable-drum laundry dryer and a rotatable-drum laundry dryer implementing the method patent info.
- - - Apple patents, Boeing patents, Google patents, IBM patents, Jabil patents, Coca Cola patents, Motorola patents

Results in 0.55856 seconds


Other interesting Freshpatents.com categories:
Tyco , Unilever , 3m

###

Data source: patent applications published in the public domain by the United States Patent and Trademark Office (USPTO). Information published here is for research/educational purposes only. FreshPatents is not affiliated with the USPTO, assignee companies, inventors, law firms or other assignees. Patent applications, documents and images may contain trademarks of the respective companies/authors. FreshPatents is not responsible for the accuracy, validity or otherwise contents of these public document patent application filings. When possible a complete PDF is provided, however, in some cases the presented document/images is an abstract or sampling of the full patent application for display purposes. FreshPatents.com Terms/Support
-g2-0.2408
     SHARE
  
           

FreshNews promo


stats Patent Info
Application #
US 20140115916 A1
Publish Date
05/01/2014
Document #
14127182
File Date
06/21/2012
USPTO Class
34282
Other USPTO Classes
34572
International Class
/
Drawings
4


Electrode
Cycle Time


Follow us on Twitter
twitter icon@FreshPatents