Patent Publication Number: US-7913523-B2

Title: Heater coupling apparatus of washing machine

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a washing machine, and more particularly, to an apparatus and a method for coupling a heater of a washing machine. 
     2. Description of the Related Art 
     A washing machine generally has a cabinet forming an outer shape thereof and a tub installed within the cabinet. The tub, which stores wash liquid within, is supported by a damper connected at the top portion of the cabinet. A wash compartment is rotatably installed within the tub. Specifically, a plurality of through-holes are formed in the bottom and side surfaces of the wash compartment, so that wash liquid stored in the tub can freely flow between the wash compartment and the tub to remove impurities from laundry. 
     A heater is installed on the floor of the tub for heating wash liquid to produce hot wash liquid. Accordingly, when the heater operates during the winter when cold water enters the tub, the water is heated to a suitable washing temperature, so that a separate water heater does not need to be installed at a water faucet. 
     However, compared to the heater and its bolts, a conventional tub is structurally weak, due to being injection molded plastic. Therefore, when stress is continuously applied to the inside of the tub, the region of the tub to which the heater is coupled is prone to cracking. Cracking results in wash liquid leaking through the cracks and a substantial decrease in product reliability of the washing machine. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a heater combining apparatus and method of a washing machine that substantially obviates one or more problems due to limitations and disadvantages of the related art. 
     An object of the present invention is to provide an improved apparatus and method for combining a heater to a tub of a washing machine that prevents cracking of the tub. 
     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a heater coupling apparatus of a washing machine, including: a tub; a heater coupling portion formed on the tub; a heater coupled to the heater coupling portion; and a bracket forming a closed loop portion in a shape of a closed loop, for disposing the heater within the closed loop portion. 
     In another aspect of the present invention, there is provided a heater coupling apparatus of a washing machine, including: a tub; a heater coupling portion formed on the tub; a heater coupled to the heater coupling portion; and a bracket interposed between the heater coupling portion and the heater, for absorbing pressure applied to the heater coupling portion by a coupling of the heater. 
     In yet another aspect of the present invention, there is provided a coupling method for a heater coupling apparatus of a washing machine, including: preparing a tub, a heater coupling portion formed on the tub, a heater, and a bracket forming a closed loop portion in a shape of a closed loop and divided into a plurality of parts; installing a first bracket portion from the plurality of parts on the tub; coupling a bracket portion other than the first bracket portion from the plurality of parts to the first bracket portion; and inserting the heater in the closed loop portion. 
     The heater combining apparatus and method of a washing machine according to the present invention forms a closed loop portion that can absorb pressure applied on the coupled regions by the coupling of the heater. Accordingly, the closed loop portion blocks the transfer of pressure, so stress on the tub from opposing the pressure can be reduced, preventing cracking of the tub. 
     It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIG. 1  is a plan view showing a heater installed on the bottom surface of a tub according to the present invention; 
         FIG. 2  is a rear perspective view of the tub with the installed heater in  FIG. 1 ; 
         FIG. 3  is a vertical sectional view showing an apparatus for combining the heater of a tub according to the present invention; 
         FIG. 4  is a perspective view of a first and a second bracket according to the present invention; 
         FIGS. 5 through 7  are diagrams-showing a combining method of a heater according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
       FIG. 1  is a plan view showing a heater installed on the bottom surface of a tub according to the present invention, and  FIG. 2  is a rear perspective view of the tub with the installed heater in  FIG. 1 . 
     Referring to  FIGS. 1 and 2 , the washing machine according to the present invention has a cylindrical tub  190  with a predetermined diameter and height. 
     Specifically, the tub  190  has damper insert holes  110  formed on the sides thereof for coupling ends of dampers thereto. A through-hole is formed at the center of the tub  190  for a washing shaft  150  to insert through. A heater receptacle  120  recessed a predetermined depth is formed at a side on the bottom surface of the tub  190  for mounting a heater  200 . 
     A drain hole  140  for draining wash liquid is formed in the floor of the heater receptacle  120 , and at least one heater cover fastening boss  130  is formed to protrude a predetermined distance from the perimeter of the heater receptacle  120 . 
     Also, a thermostat  122  is mounted on a side of the heater receptacle  120 , for determining whether the heater  200  has been heated, and a clamp  121  for fixing the heater is disposed above the thermostat  122 . 
     A heater insert hole  191  is formed at the bottom surface of the tub  190  for inserting the heater  200 . In detail, the insert hole  191  is formed to protrude a predetermined depth into the bottom surface of the tub  190 , in order to prevent moisture or wash liquid from entering the terminals of the heater  200 . 
     Here, the heater insert hole  191 , as a portion for coupling the heater  200  to the tub  190 , may be defined as a heater coupling portion. This heater coupling portion may adopt various embodiments other than the heater insert hole  191 . 
     The heater  200  received in the heater receptacle  120  includes a heater pipe  201  formed with a predetermined diameter and length and bent a plurality of times at a predetermined location, and a power connector  203  formed at each end of the heater pipe  201  to electrically connect to the heater pipe  201  for supplying power thereto. 
     The heater  200  also includes a sealing member  210  inserted through the power connector  203 . Before the sealing member  210  is inserted, a pressing plate  206  for pressing the sealing member is first inserted. A sealing case  202 , recessed a predetermined depth to accommodate the sealing member  210 , is inserted at the rear of the sealing member  210 , for preventing leakage of wash liquid from the heater insert hole  191 . Here, the sealing case  202  is tightly pressed against the outer wall of the tub  190  through a tightening member (to be described later). 
     The pressing plate  206  and the sealing case  202  are firmly tightened with an assembly bolt  205  passing through the center of the pressing plate  206  and an assembly nut  204 . In further detail, the sealing member receives a high level of pressure between the pressing plate  206  and the sealing case  202  from the assembly nut  204  that tightens along the threaded outer portion of the assembly bolt  205 . Here, the sealing member uses a material with a predetermined elasticity and flexibility, which may be rubber. 
     In further detail, the sealing member may have the same shape as the heater insert hole  191  or be slightly smaller, so that it can easily insert into the heater insert hole  191 . However, the thickness of the sealing member is formed to be thicker than the tub  190 . 
     Here, when the sealing member receives pressure from the assembly bolt  205  and the assembly nut  204 , the upper portion of the sealing member flattens within the inner perimeter of the tub  190 , as shown in the diagrams. Thus, the surface area of the sealing member becomes wider than that of the heater insert hole  191 . Accordingly, the sealing member widens with pressure to completely seal the heater insert hole  191 , to prevent wash liquid leaking into the heater insert hole  191 . 
     The heater pipe  201  of the heater  200 , as described above, has a predetermined diameter and length, and is made of a conductive material that is bent a plurality of times. Here, the length of the heater pipe  201  and the number of times it is bent may depend on the required length, number of bends, etc. of the heater pipe  201 . 
     In the present invention, by installing a first bracket portion  310  and a second bracket portion  320  as a pair, cracking may be prevented when the heater  200  is combined with the tub  190 . This will be described in more detail below. 
       FIG. 3  is a vertical sectional view showing an apparatus for combining the heater of a tub according to the present invention. 
     Referring to  FIG. 3 , the combining structure of a heater to a tub according to the present invention includes a heater  200  for heating wash liquid inside a tub, a tub  190  for combining the heater  200  to, and a first and a second bracket portion  310  and  320  for preventing cracking of the tub  190 . Here, the first and second bracket portions  310  and  320  form a bracket  300 . 
     The heater  200  includes a pressing plate  206 , a sealing case  202  contacting the wash liquid and formed at the end of a heater pipe  201  that heats the wash liquid, and a sealing member  210  provided between the heater  200  and the tub  190  for sealing the gap therebetween. The heater  200  may be cohered with the pressing plate  206 , the sealing case  202 , and the sealing member  210  through a separate assembly bolt  205  and nut  204 . 
     The tub  190  includes a bracket insert hole  191  formed for inserting a predetermined part of the first bracket portion  310 , and a bracket insert hole forming portion  192  for forming the bracket insert hole  191 . 
     The first and second bracket portions  310  and  320  contact the sealing member when the heater  200  is coupled to the tub  190 . In other words, the first and the second bracket portions  310  and  320  prevent direct contact between the sealing member and the tub  190 , or more specifically, between the sealing member and the bracket insert hole forming portion  192 . When thus structured, and the heater is coupled  200 , the pressure applied to the inserted sealing member is transferred to the first and second bracket portions  310  and  320  it contacts. Thus, virtually none of the pressure from the sealing member is transferred to the tub  190 , or more specifically, to the bracket insert hole forming portion  192 . Therefore, stress in the tub  190  reacting to the pressure is reduced. Accordingly, due to the insertion of the sealing member, cracking of the tub  190  can be prevented. 
     According to this embodiment, a bracket sealing portion  330  for sealing the space between the first and second bracket portions  310  and  320  is installed between said first and second bracket portions  310  and  320 . In this configuration, the space between the first and second bracket portion  310  and  320  is sealed. Thus, the sealing function of the bracket sealing portion  330 , along with the sealing function of the sealing member sealing the space between the bracket  300  and the heater  200 , can increase the reliability of the seal between the heater  200  and the tub  190 . 
       FIG. 4  is a perspective view of a first and a second bracket according to the present invention. 
     Referring to  FIG. 4 , the first and second bracket portions  310  and  320  according to the present invention form the bracket  300  and are coupled to the tub  190  to prevent cracking of the tub  190 . 
     Here, the bracket  300  is divided into a first and second bracket portion  310  and  320 ; however, this is only exemplary. That is, the bracket  300  may be divided into a plurality of bracket portions and may be formed by coupling the various bracket portions. 
     The first bracket portion  310  includes a heater insert hole  311  for inserting the heater  200 , and a closed loop portion  312  forming the heater insert hole  311 . A tub coupling portion  314  is formed to extend from the closed loop portion  312  on the first bracket portion  310  to form the periphery of the closed loop portion  312 . The tub coupling portion  314  is a portion for coupling the bracket  300  and the tub  190 . 
     The closed loop portion  312  autonomously forms a closed loop. Thus, the closed loop portion  312  can absorb pressure put on the heater coupling portion  191  when the heater  200  is inserted therein. Accordingly, the closed loop portion  312  blocks the transfer of pressure from the heater coupling portion  191 , so that the cracking of the tub  190  is prevented. 
     The closed loop  312  is connected to the tub coupling portion  314 . Also, the closed loop portion  312  forms a shape corresponding to the shape of the portion of the heater  200  that inserts into the closed loop portion  312 . The closed loop portion  312  also passes through the heater coupling portion  191 . 
     In the above structure, the first bracket portion  310  is coupled to the tub  190 , after which the inner surface of the closed loop portion  312  contacts the sealing member and functions as a seal. Therefore, the sealing member and the tub  190  do not directly contact one another, and the pressure of the sealing member is not transferred, so that cracking of the tub  190  can be prevented. 
     A first coupling hole  313  is formed in the tub coupling portion  314  so that the second bracket portion  320  and the tub  190  may be coupled through a separate bolt or other coupling member. In order to increase the coupling reliability of the first coupling hole  313 , each part of the first bracket portion  310  may be formed in plurality. 
     A second coupling hole  321  is formed in the second bracket portion  320  opposite the first coupling hole  313 , for the coupling member fixed in the first coupling hole  313  to pass through. 
     As described above, the first bracket portion  310  forms a portion surrounding the closed loop portion  312 , to allow the bracket sealing portion  330  that seals the space between the bracket  300  and the tub  190  to be further installed. 
       FIGS. 5 through 7  are diagrams showing a combining method of a heater according to the present invention. 
     Referring to  FIGS. 5 through 7 , the combining method of the heater  200  according to the present invention will now be described. Here, the description of each element shall be deemed replaced by the previous descriptions thereof, and repetitive descriptions shall thus be omitted. 
     First, as shown in  FIG. 5 , a tub  190  is made. The bracket insert hole  191  and the bracket insert hole forming portion  192  are formed in the tub  190 . 
     Next, as shown in  FIG. 6 , the first bracket portion  310  is inserted in the bracket insert hole  191 . The inserting of the first bracket portion  310  is performed from the inside to the outside of the tub  190 . Then, the closed loop portion  312  protrudes out of the tub  190 . Here, the bracket sealing portion  330  installed around the closed loop portion  312  contacts the tub  190 . 
     Subsequently, as shown in  FIG. 7 , the second bracket portion  320  is coupled to the first bracket portion  310 . This coupling may be performed by passing a bolt or other separate coupling member through the first and second coupling holes  313  and  321 . When the above coupling is done, the first and second bracket portions  310  and  320  may be fixed to the tub  190 . This coupling compresses and deforms the bracket sealing portion  330  disposed between the first and second bracket portions  310  and  320 , so that the space between the first bracket portion  310 , second bracket portion  320 , and tub  190  is sealed. 
     Thereafter, the heater  200  is inserted in the heater insert hole  311 , and the sealing member that is a component of the heater  200  is inserted in the heater insert hole  311  to contact the closed loop portion  312 . In this condition, when the assembly bolt and nut  204  and  205  are tightened, the tightening compresses the sealing member and deforms it. The sealing member thus presses against the closed loop portion  312  that it contacts. 
     As described above, the pressure on the sealing member of the present invention is transferred to the first and second bracket portions  310  and  320 , and is thus prevented from being transferred to the tub  190 . In this way, stress that may be generated in the tub  190  in opposition to pressure is reduced, and cracking of the tub  190  can be prevented by the insertion of the sealing member. 
     The heater combining apparatus and method of a washing machine according to the present invention forms a closed loop portion and absorbs pressure applied to a heater coupling portion through the coupling of the heater. Therefore, the closed loop prevents transferring of the pressure to the tub, and reduces stress that may otherwise be generated in the tub to counter the pressure, so that cracking of the tub can be prevented. 
     Also, the heater combining apparatus and method according to the present invention further installs a bracket sealing portion to reliably seal the space between the bracket and the tub. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.