Patent Publication Number: US-9896797-B2

Title: Dryer for clothes

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application is a U.S. National Stage Application under 35 U.S.C. § 371 of PCT Application No. PCT/KR2015/003731, filed Apr. 14, 2015, which claims priority to Korean Patent Application No. 10-10-2014-0045717, filed Apr. 17, 2014, whose entire disclosures are hereby incorporated by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a dryer for clothes. 
     BACKGROUND ART 
     Dryers for clothes are home appliances that supply hot air into a drying drum to remove moisture absorbed into clothes in a state where objects to be dried are put into the rotating drum. Hot air supplied into a drum may be generated by using electrical resistance heat or combustion heat using a gas fuel. Then, the hot air may be supplied into the drying drum by using a blower fan. 
     Also, dryers for clothes may be classified into forced convection dryers and air vented dryers according to a hot air supply method. That is, the forced convection dryers may be dryers in which hot air supplied into a drying drum is repeatedly heated and cooled while circulating the inside of the dryer, and the air vented dryers may be dryers in which hot air supplied into a drying drum is discharged from the drying drum to the outside. 
     During the drying of clothes, lint attached to clothes may be separated and thus floated in air discharged from a drying drum, and foreign substances existing in the clothes may drop onto the bottom of the during drum. To remove the lint contained in the air discharged from the drying drum, a lint filter assembly is mounted in a passage through which the air discharged from the drying drum flows. 
     When the lint is deposited on the lint filter assembly, the lint may interrupt a flow of air to increase a load of the blower fan. As a result, drying performance may be deteriorated, power consumption may increases, and the lint may act as a failure cause of the blower fan. Furthermore, the lint generated during the drying process may be introduced into a fan motor or combustion device that is mounted on a lower portion of the drying drum through a gap between the drying drum and a cabinet to cause fire in the dryer. 
     To solve this limitation, the foreign substances deposited on the lint filter assembly have to be periodically removed. In case of a detachable lint filter assembly, a user may periodically separate the lint filter assembly to clean the lint filter assembly and then mount the lint filter assembly again. 
     Various methods for easily removing lint deposited on the lint filter assembly are being attempted. Recently, a lint removing structure of for removing lint by using water in a state where a lint filter assembly is mounted within the dryer is being proposed. For example, a filter cleaning device of a clothes dryer is disclosed in Korean Patent Registration No. 10-1186159. 
     In Korean Patent Registration No. 10-1186159 according to the related art, water is sprayed through nozzles disposed at front and rear sides of the lint filter assembly to remove lint deposited on the lint filter assembly. However, the lint filter assembly mounted on the cloths dryer according to the related art may be a mash-shaped filter. Thus, the lint filter assembly may generate a lint deposition lump having a size corresponding to that of the filter. Also, when the water is sprayed through the nozzles, the lint lump separated from the lint filter assembly may have a significantly large size. The water sprayed from the nozzles and the lint lump separated from the lint filter assembly may be introduced into a drain pump and then discharged to the outside of the dryer. However, since a pumping chamber in which an impeller of the drain pump is accommodated has an inlet that has a size significantly less than that of the lint lump separated from the lint filter assembly, the lint lump may block the inlet or an outlet of the pumping chamber to increase a load of the drain pump. Also, the increase of the load of the drain pump may ultimately cause a damage of the drain pump. 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     The present disclosure is proposed to improve the above-described limitations. 
     Solution to Problem 
     In one embodiment, a dryer for clothes includes: a cabinet; a drying drum accommodated in the cabinet and into which an object to be dried is put; a suction passage supplying hot air into the drying drum; a heating unit disposed in any position of the suction passage to heat the air introduced into the suction passage at a high temperature; an exhaust passage through the hot air discharged from the drying drum flows; a blower mounted on one position of the exhaust passage to forcibly blow the air within the drying drum; a lint filter assembly mounted on the other position of the exhaust passage; and a lint filter cleaning device for removing lint attached to the lint filter assembly, wherein the lint filter assembly includes: a filter frame defining an edge thereof; a mesh member attached to the filter frame to cover an inner region of the filter frame; and a partition rib including a plurality of horizontal ribs and vertical ribs which are disposed inside the filter frame, wherein the mesh member is partitioned into a plurality of filtering blocks by the plurality of horizontal ribs and vertical ribs. 
     Advantageous Effects of Invention 
     According to the dryer for the clothes according to the embodiment, the partition rib having the lattice structure may be disposed inside the filter frame of the lint filter assembly to divide and collect the lint generated during the drying onto the lint filter assembly. Thus, the lint lump separated from the lint filter assembly while the lint filter assembly is cleaned may be minimized in size. 
     Also, the limitation in which the lint separated from the lint filter assembly blocks the inlet and outlet of the drain pump to deteriorate the drying performance may be improved. 
     Also, in the dryer of the clothes according to the embodiment, the lint filter assembly is partitioned into the plurality of filtering blocks, and a difference between the filter cleaning times for the blocks may be generated. Thus, since the lint lumps each of which has a small size are introduced to the drain pump with a time difference, the phenomenon in which the inlet and outlet of the pumping chamber of the drain pump are blocked by the lint lumps may be minimized. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a dryer for clothes including a lint filter cleaning device according to an embodiment. 
         FIG. 2  is a side view of the dryer for the clothes. 
         FIG. 3  is a perspective view of the lint filter cleaning device according to an embodiment. 
         FIG. 4  is a perspective of a control valve provided in the lint filter cleaning device according to an embodiment. 
         FIG. 5  is an exploded perspective view of the control valve. 
         FIG. 6  is a cross-sectional view taken along line VI-VI of  FIG. 3 . 
         FIG. 7  is a perspective view illustrating an outer appearance of a lint filter assembly mounted on the lint filter cleaning device according to an embodiment. 
         FIG. 8  is a longitudinal cross-sectional view taken along line VIII-VIII of  FIG. 7 . 
         FIG. 9  is a perspective view illustrating an outer appearance of a lint filter assembly according to another embodiment. 
         FIG. 10  is a perspective view illustrating an outer appearance of a lint filter assembly according to further another embodiment. 
         FIG. 11  is a longitudinal cross-sectional view taken along line XI-XI of  FIG. 10 . 
     
    
    
     MODE FOR THE INVENTION 
     Hereinafter, a dryer for clothes including a lint filter cleaning device according to an embodiment will be described in detail with reference to the accompanying drawings. Also, an air vented dryer will be described as an example of the dryer for the clothes including the lint filter cleaning device according to an embodiment. However, the lint filter cleaning device according to an embodiment may be applied to various types of dryers for clothes including a forced convection dryer as well as the air vented dryer. 
       FIG. 1  is a perspective view of a dryer for clothes including a lint filter cleaning device according to an embodiment, and  FIG. 2  is a side view of the dryer for the clothes. 
     Referring to  FIGS. 1 and 2 , a dryer for clothes (hereinafter, referred to as a “clothes dryer”) including a lint filter cleaning device according to an embodiment may include a drying drum  11  into objects to be dried are put, a front cabinet  12  supporting a front part of the drying drum  111 , a blocking member mounted on a bottom part of the front cabinet  12 , a rear cabinet  13  supporting a rear part of the drying drum  11 , and a lint filter cleaning device  30  disposed under the drying drum  11 . 
     Also, the clothes dryer  10  may further include a suction duct  21  for suctioning air to be supplied into the drying drum  11 , a rear duct  19  connecting the suction duct  21  to an air inflow hole defined in a rear surface of the drying drum  11 , a guide duct  15  connected to a bottom surface of the front cabinet  12  to guide air discharged from the drying drum  11 , a blower  16  connected to an outlet end of the guide duct  15 , and an exhaust duct  20  connected to an outlet end of the blower  16 . 
     The lint filter cleaning device  30  may be mounted on any position of the exhaust duct  20  to filter lint contained in air flowing along the exhaust duct  20  while the air passes through a lint filter assembly provided in the lint filter cleaning device  30 . 
     A middle cabinet (not shown) is disposed between the front cabinet  12  and the rear cabinet  13  to protect the drying drum  11  and various components disposed under the drying drum  11 . The middle cabinet may define both side surfaces and top surface of the clothes dryer  10 . A base plate  101  defining a bottom part of the clothes dryer  10  may be disposed on a bottom surface of the middle cabinet, and the components may be mounted on the base plate  101 . 
     Also, the blocking member  14  may prevent foreign substances contained in the objects to be dried, for example, bulky and hard foreign matters a coin, a ballpoint pen, and the like from being suctioned into the guide duct  15  during the drying process. The foreign substances such as the lint may be filtered by the lint filter assembly (that will be described later) mounted on the lint filter cleaning device  30  even though the foreign substances are introduced into the guide duct  15 . Other foreign substances, i.e., bulky and soft foreign matters may be blocked by the blocking member  14  to remain in the drying drum  11 . 
     If foreign substances except for the lint are suctioned into the guide duct  15 , the blower  16  may be damaged, or a rattling sound may be generated inside the exhaust duct  20 . Thus, it may be necessary to prevent the foreign substances from being out of the drying drum  11  through the blocking member  14 . Also, the blocking member  15  may be detachably coupled to the front cabinet  12 . 
     Also, the lint filter cleaning device  30  is connected to a cleaning water supply tube  17  and a cleaning water drain tube  18 . The cleaning water supply tube  17  may have an inlet end mounted on the rear cabinet  13  and connected to a water supply tube  2  connected to an external water supply source  1 . Also, the cleaning water supply tube may have an outlet end connected to an inflow port  353  of a control valve (see reference numeral  35  of  FIG. 4 ) of the lint filter cleaning device  30 . Also, the cleaning water drain tube  18  may have an inlet end connected to a drain pump (see reference numeral  36  of  FIG. 3 ) of the lint filter cleaning device  20 . 
     Also, the blower  16  may include a fan motor  161  and a blower fan  162  connected to a rotation shaft of the fan motor  161 . The blower fan  162  is disposed on an output end of the guide duct  15  to guide the air, which passes through the drying drum  11  and guided to the guide duct  15 , to the exhaust duct  20 . 
     Also, in case of the air vented dryer, a gas combustion device is disposed on an inlet of the suction duct  21  to heat air suctioned into the suction duct  21  at a high temperature. Also, in case of an electric dryer, an electric heater is mounted inside the rear duct  19  to heat air introduced into the suction duct  21  at a high temperature before the air is introduced into the drying drum  11 . 
     Briefly explaining the drying process of the clothes dryer  10  including the above-described constitutions, objects to be dried are put into the drying drum  11  through an input hole  121  defined in the front cabinet  12 . 
     Also, when a drying start command is inputted, the blower  16  operates to the air introduced into the suction duct  21  at a high temperature by using the gas combustion device or electric heater. 
     Then, the air heated at the high temperature is introduced into the drying drum  11  through a rear surface of the drying drum  11  along the rear duct  19 . The high-temperature and dry air introduced into the drying drum  11  changes into high-temperature and humidity air while drying the objects to be dried. 
     Also, the high-temperature and humidity air passes through the blocking member  14  in a state where the air contains lint generated from the objects to be dried and then is guided to the guide duct  15 . Also, the high-temperature and humidity air guided to the guide duct  15  is guided to the exhaust duct  20  by the blower  16 . 
     Also, the lint contained in the high-temperature and humidity air guided to the exhaust duct  20  is filtered by the lint filter assembly while passing through the lint filter cleaning device  30 . Also, the lint filter cleaning device  30  operates to separate the lint attached to the lint filter assembly and then discharge the lint together with cleaning water by using the drain pump. 
     Hereinafter, a structure and operation of the lint filter cleaning device  30  will be described with reference to the accompanying drawings. 
       FIG. 3  is a perspective view of the lint filter cleaning device according to an embodiment. 
     Referring to  FIG. 3 , the lint filter cleaning device  30  according to an embodiment may include a cleaning case  31  constituted by a filter housing  311  and a pump housing  312 , a lint filter assembly  32  disposed inside the filter housing  311 , a water supply port array  33  disposed on a top surface of the lint filter assembly  32 , a water supply tube array  34  connected to an outlet end of the water supply port array  33 , a control valve  35  connected to an inlet end of the water supply tube array  34 , and a drain pump accommodated within the pump housing  312 . 
     The lint filter assembly  32  vertically stands up inside the filter housing  311 . Also, an inflow hole  313  through which the high-temperature and humidity air passing through the drying drum  11  is introduced is defined in one side of the filter housing  311 , and a discharge hole  314  through which the high-temperature and humidity air passing through the lint filter assembly  32  is discharged is defined in a surface opposite to the surface in w which the inflow hole  313  is defined. Also, the pump housing  312  and the filter housing  311  communicate with each other through a communication hole (see reference numeral  315  of  FIG. 6 ). 
     Also, the water supply port  33  may include a plurality of ports that are disposed to be spaced a predetermined distance from each other on a top surface of the lint filter assembly  32 . Although the water supply port array  33  includes first to fourth supply ports  331 ,  332 ,  333 , and  334  in the current embodiment, the present disclosure is not limited thereto. For example, the number of supply ports may be adequately set according to a size of the lint filter assembly  32 . 
     Also, the water supply tube array  34  may include a plurality of supply tubes connected to the water supply port array  33 . Although the water supply array  34  includes first to fourth water supply tubes  341 ,  342 ,  343 , and  344  in the current embodiment, the present disclosure is not limited thereto. For example, the number of water supply tubes may be adequately set according to the number of supply ports. 
     Also, a hole into which the lint filter assembly  32  is inserted is defined in a top surface of the filter housing  311 . 
       FIG. 4  is a perspective of the control valve provided in the lint filter cleaning device according to an embodiment, and  FIG. 5  is an exploded perspective view of the control valve. 
     Referring to  FIGS. 4 and 5 , the control valve  35  provided in the lint filter cleaning device  30  according to an embodiment may include a valve case  351  having a changer into which water supplied from the external water supply source  1  is collected, a control disk  355  having a disk shape and rotatably disposed inside the valve case  351 , a valve motor  352  of which a rotation shaft is connected to a center of the control disk  355  to rotate the control disk  355 , a valve cover coupled to a front side of the valve case  351  to cover a front opening of the valve case  351 , and an inflow port  353  connected to one side surface of the valve case  351 , and a discharge port array  354  disposed on the valve cover  356 . Also, one or a plurality of communication holes  355   a  may be defined on one side of the control disk  355 . 
     In detail, the discharge port array  354  may include first to fourth discharge ports  354   a ,  354   b ,  354   c , and  354   c . The number of discharge ports may correspond to that of water supply ports. Also, inlet ends of the discharge ports may be disposed to be spaced a predetermined distance from each other in a circumferential direction of the valve cover  356 . 
     As the control disk  355  rotates at a predetermined angle, the communication hole  355   a  may be disposed at one inlet end of the plurality of discharge ports to open the discharge port facing the communication hole  355   a.    
     When one communication hole  355   a  is provided, only one discharge port of the plurality of discharge ports may be opened. As the control disk  355  rotates, the plurality of discharge ports may be successively opened. 
     Also, the discharge port to be opened may be determined by a rotation angle of the control disk  355 . In addition, an opening rate of the discharge port may be determined according to the rotation rate of the control disk  355 . 
     When the communication hole  355   a  is provided in plurality, the plurality of discharge ports may be opened at the same time. Also, the discharge ports to be opened at the same time may be determined by the distance between the plurality of communication holes  355   a  in the circumferential direction within the control disk  355 . Also, the discharge ports to be opened at the same time may be determined by the rotation angle of the control disk  355 , and an opening rate of the discharge ports may be determined by the rotation rate of the discharge ports. 
     Inlet ends of the first to fourth water supply tubes  341  to  344  are connected to the first to fourth discharge ports  345   a  to  345   d , respectively. The cleaning water supplied into the valve case  351  through the inflow port  353  may be supplied into the water supply port array  33  along the water supply tube array  34 . 
     The water supplied into the water supply port array  33  may flow downward along the lint filter assembly  32  to separate the lint lump attached to the lint filter assembly  32  from the lint filter assembly  32 . 
       FIG. 6  is a cross-sectional view taken along line VI-VI of  FIG. 3 . 
     Referring to  FIG. 6 , the pump housing  312  and the filter housing  311  of the lint filter cleaning device  30  according to an embodiment are fluidly connected to each other through the communication hole  315  as described above. 
     In detail, the pump housing  312  is disposed outside the filter housing  311 . The communication hole  315  is defined in one position of a bottom part of a wall that defines the filter housing  311  and partitions the pump housing  312  from the filter housing  311 . 
     Also, the bottom part of the filter housing  311  may be inclined upward in a direction that is away from the communication hole  315 . Thus, the cleaning water supplied from the water supply port array  33  to flow down along the filter assembly  31  and the lint lump may flow toward the communication hole  315  and then be concentrated into the pump housing  312 . Also, the drain pump  36  may operate to discharge the lint lump and the cleaning water to the outside of the dryer. 
       FIG. 7  is a perspective view illustrating an outer appearance of a lint filter assembly mounted on the lint filter cleaning device according to an embodiment, and  FIG. 8  is a longitudinal cross-sectional view taken along line VIII-VIII of  FIG. 7 . 
     Referring to  FIGS. 7 and 8 , the lint filter assembly according to an embodiment may include a bracket  321  seated on a top surface of the filter housing  311 , a filter frame  326  having an approximately rectangular shape that vertically extends downward from a bottom surface of the bracket  321 , a partition rib  327  partitioning the inside of the filter frame  326  in a lattice shape, and a mesh member  325  coupled to an inner space part of the filter frame  326 . 
     In detail, the partition rib  327  may be integrated with the filter frame  326  as one body. A plurality of vertical ribs  327   a  and horizontal ribs  327   b  may be disposed in directions perpendicular to each other. Thus, the mesh member  325  may be partitioned by a plurality of filtering blocks. 
     The plurality of filtering blocks may have the same size. On the other hand, the filtering blocks may be designed so that the filtering blocks have sizes that gradually decrease or increase toward a lower side of the lint filter assembly  32  by adjusting a distance between the vertical ribs  327   a  and a distance between the horizontal ribs  327   b . For example, the filtering blocks may have heights or widths that gradually increase or decrease toward the lower side of the lint filter assembly  32 . 
     Also, the mesh member  325  may be attached to a front surface of the filter frame  326 . Here, the front surface of the filter frame  326  may be defined as a surface opposite to a surface that collides with the air flowing along the guide duct  15 . 
     Also, a plurality of port mounting parts  322  is disposed on the bracket  321 . The plurality of port mounting parts  322  may be provided in number corresponding to that of plurality supply ports  331  to  334 . In the current embodiment, first to fourth port mounting parts may be provided. 
     Also, a water guide  323  extends from a bottom surface of the bracket  321 , which corresponds to a lower side of each of the port mounting parts  322 . An inlet of the water guide  323  may communicate with the port mounting part  322 , and an outlet of the water guide  323  may communicate with the one or plurality of filtering blocks in a transverse direction. 
     Also, a discharge hole  324  is defined in an outlet end of the water guide  323  so that the cleaning water flows downward. The discharge hole  324  may be a slit defined in a bottom part of the water guide  323  in a transverse direction. Also, the slit may have a length corresponding to a width of each of one or plurality of filtering blocks in the transverse direction. 
     For example, in case of a structure in which one water guide  323  covers a single filtering block, the port mounting part  322  having numbers corresponding to that of filtering blocks disposed in transverse direction may be disposed inside the lint filer assembly  32 . Also, the discharge hole  324  may have a width corresponding to that of one filtering block. 
     Alternatively, in case of a structure in which one water guide  323  covers two filtering blocks, the port mounting part  322  having numbers corresponding to a half of the number of filtering blocks in the transverse direction may be provided. Here, the width of the discharge hole  324  may doubly increase. 
     According to the above-described structure, the cleaning water guided by the water guide  323  may flow down from the uppermost filtering block to the lowermost filtering block along the mesh member  325 . Here, the lint lump collected onto each of the filtering blocks may flow down together with the cleaning water. Also, the separated lint lump and cleaning water may be collected into the pump housing  312  through the communication hole  315  along the inclined bottom surface of the filter housing  311 . 
     A flow groove  328  may be defined between the mesh member  325  and the horizontal rib  327   b  so that the cleaning water smoothly flows down along the mesh member  325 . The flow groove  328  may be a long grove that is recessed by a predetermined depth from a front surface of the horizontal rib  327   b  contacting the mesh member  325 . The flow groove  328  may be defined by the horizontal rib  327   b  that defines each of the filtering blocks. 
     Here, when the cleaning water is supplied into the plurality of supply ports  331 ,  332 ,  333 , and  334  at the same time, lint attached to the filtering block of the lint filter assembly  32  may be separated once to drop down onto the bottom of the filter housing  311 . As a result, a large amount of lint lumps may be introduced into the drain pump  36  at the same time to block the drain pump  36 . Thus, the drain pump  36  may become to an abnormal state. To solve the above-described limitation, it may be necessary to separate a small amount of lint lumps from the filtering blocks with a time difference and to allow the separated lint lumps to flow into the drain pump  36 . 
     For this, the supply ports  331 ,  332 ,  333 , and  334  constituting the water supply port array  33  may be alternately opened with a time difference. For example, the control valve  35  may operate to successively open supply ports  331  to  334  from the first supply port  331  that is the closet to the drain pump to the fourth supply port  334  that is the farthest to the drain pump to prevent the lint lumps from being introduced into the drain pump  36  at once. 
     Alternatively, the control valve  35  may operate so that odd-numbered supply ports  331  and  333  are opened first, and then even-numbered supply ports  332  and  334  are opened after a preset time elapses. 
     Also, the lint filter cleaning process may be partitively performed several times during the cleaning process to prevent a large amount of lint lumps from being introduced into the drain pump at once. 
     As described above, in the lint filter cleaning device  30  according to an embodiment, the mesh member  325  of the lint filter assembly  32  may be partitioned into the plurality of filtering blocks to form a plurality of lint lumps each of which has a small size. 
     Furthermore, the opening degree may be variously controlled by the control valve  35 . 
     Thus, the lint lumps attached to the lint filter assembly  32  may not be separated at once, but be successively separated with a time difference. As a result, the blocking of the inlet of the drain pump  35  may be prevented. 
       FIG. 9  is a perspective view illustrating an outer appearance of a lint filter assembly according to another embodiment. 
     Referring to  FIG. 9 , a lint filter assembly  32  according to the current embodiment has the same structure as the lint filter assembly  32  of  FIG. 8  except for only a structure of a flow groove  328 . 
     In detail, in case of the lint filter assembly  32  according to the foregoing embodiment, one long groove is defined in each of the filtering blocks. However, according to the current embodiment, a plurality of short grooves are defined to be spaced a predetermined distance from each other. 
     Since the lint filter assembly  32  has the same structure as that according to the foregoing embodiment except for the groove, duplicated descriptions will be omitted. 
       FIG. 10  is a perspective view illustrating an outer appearance of a lint filter assembly according to further another embodiment, and  FIG. 11  is a longitudinal cross-sectional view taken along line XI-XI of  FIG. 10 . 
     Referring to  FIGS. 11 and 12 , a lint filter assembly  42  according to the current embodiment includes a bracket  421 , a water guide  423 , a discharge hole  424 , a mesh member  325 , and a partition rib constituted by a vertical rib  427   a  and a horizontal rib  427   b . The above-described components are the same as those according to the foregoing embodiment. 
     However, unlike the foregoing embodiment, the filter frame  426  is different in that the filter frame  426  is stepped in a stair shape. That is, the current embodiment may be different from the foregoing embodiment in that a stepped part  428  having the stair shape is disposed on each of both ends of the horizontal rib  427   b , and cleaning water flowing from the water guide  423  flows in stages along the mesh member  425  and the horizontal rib  427   b.    
     In detail, since the filter frame  426  is stepped in the stair shape, the mesh member  425  may be attached in the stair shape along a front surface of the filter frame  426 . 
     That is, the mesh member  425  defining an upper filtering block may be disposed on a front surface of the horizontal frame  427   b  disposed between two filtering blocks adjacent to each other, and the horizontal frame  427   b  may have a structure having the same plane as the mesh member  425  defining a lower filtering block. 
     Thus, the cleaning water flowing trough the discharge hole  424  may flow along the mesh member  425  defining the upper filtering block and then flow along the top surface of the horizontal rib  427   b  to flow along the mesh member  425  defining the lower filter block. 
     As a result, the cleaning water successively flows from the uppermost filtering block to the lowermost filtering block to separate the lint lump attached to the uppermost filtering block and then separate the lint limp attached to the filter block disposed under the uppermost filtering block. 
     As described above, since the filter frame  326  is stepped in the stair shape, even though a separate flow groove is not defined in the front surface of the horizontal rib  427   b , the cleaning water may smoothly flow down along the filtering assembly  42  to successively separate the lint lumps.