Patent Publication Number: US-2007114191-A1

Title: Positioning rack for thin-type electrothermal straps

Description:
FIELD OF THE INVENTION  
      This is a Continuation-In-Part application of applicant&#39;s former patent application with application Ser. No. 10/792,700, filed Mar. 05, 2004. 
    
    
     BACKGROUND OF THE INVENTION  
      A conventional positioning rack for mounting electrothermal straps  3  used in heating fan, for example is shown in  FIGS. 1-3  and comprises a fixing bracket  1  having a base  102  and a plurality of support arms  104  extend from the base  102 . A plurality of insulating members  2  each are mounted on a respective one of the support arms  104  of the fixing bracket  1  and each have a side formed with a plurality of separation portions  204 , and a plurality of positioning recesses  202  are located between the separation portions  204  for positioning electrothermal straps  3 .  
      Each of the insulating members  2  is fixed on a respective one of the support arms  104  of the fixing bracket  1  by a plurality of rivets with manual aid of a special tool. However, it is difficult to rivet the insulating members  2  by riveting tools because the gap between the support arms  104  are limited, so that the tools easily touches and collides the insulating members  2  during the riveting process, thereby easily wearing or breaking the insulating members  2 . In addition, the insulating members  2  are fixed the support arms  104  of the fixing bracket  1  and only limited space allows tools to access the rivets, so that when either one of the insulating members  2  is worn out or broken, it is necessary to replace the whole positioning rack, thereby wasting the resource, and thereby increasing the costs.  
     SUMMARY OF THE INVENTION  
      The primary objective of the present invention is to provide a positioning rack for mounting thin-type electrothermal straps for an electric appliance, wherein the blade plates can be easily and conveniently connected to and removed from the support arms without needing aid of a tool.  
      In accordance with the present invention, there is provided a positioning rack which comprises a main frame having a tubular base and a plurality of support arms extend radially from the tubular base. Two locking members extend from one of two opposite surfaces of each support arm and each locking member has a locking post and a catch block which is connected to a distal end of the locking post corresponding thereto. The locking post is connected to the surface of the support arm.  
      A plurality of blade plates each have a plurality of hook-shaped separation portions extend from each of two sides thereof and a plurality of positioning recesses are located between the separation portions. Two guide slots and two locking grooves are defined through each of the blade plates. The locking grooves are respectively communicate with the two guide slots. The guide slots each are sized to allow the catch block to pass therethrough and a width of each locking groove is sized to receive the locking post and smaller than a width of each catch block so that the blade plate is not disengaged from the support arm by the catch block. Each of the blade plates is partially clamped between the surface of each support arm and the catch block.  
      In accordance with another embodiment of the present invention, wherein a connection tube is connected between two tubular bases of two main frames so that the two main frames can be connected with each other.  
      Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a partially perspective view of a fixing bracket of a conventional positioning rack in accordance with the prior art;  
       FIG. 2  is a plan view of an insulating member of the conventional positioning rack in accordance with the prior art;  
       FIG. 3  is a plan view of the conventional positioning rack in accordance with the prior art;  
       FIG. 4  is a partially exploded perspective view of a positioning rack in accordance with the preferred embodiment of the present invention;  
       FIG. 5  is a plan view of a blade plate of the positioning rack in accordance with the preferred embodiment of the present invention;  
       FIG. 6  is a plan cross-sectional view of a locking member of the positioning rack in accordance with the preferred embodiment of the present invention;  
       FIG. 7  shows that the electrothermo straps are positioned on the blade plates of the positioning rack in accordance with the preferred embodiment of the present invention;  
       FIG. 8  shows the blade plate is to be engaged with the locking member on the support arm;  
       FIG. 9  shows that the blade plate is pivoted an angle to disengage the electrothermo straps from the positioning recesses of the blade plate;  
       FIG. 10  is an exploded view of another embodiment of the positioning rack of the present invention; and  
       FIG. 11  shows the connection between the two tubular bases and the connection tube between the two positioning racks of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring to the drawings and initially to  FIGS. 4-6 , a positioning rack in accordance with the preferred embodiment of the present invention comprises a main frame  10  having a tubular base  12  and a plurality of support arms  14  extend radially from the tubular base  12 . Each support arm  14  has two locking members  16  extending from one of two opposite surfaces thereof and each locking member  16  has a locking post  162  and a catch block  164 , wherein the locking post  162  is connected to the surface of the support arm  14  and the catch block  164  is connected to a distal end of the locking post  162  corresponding thereto.  
      A plurality of blade plates  20  each have a plurality of hook-shaped separation portions  24  extending from two sides thereof and a plurality of positioning recesses  22  are located between the separation portions  24 . Two guide slots  26  and two locking grooves  28  are defined through each of the blade plates  20 . The locking grooves  28  respectively communicate with the two guide slots  26 . The guide slots  26  and the locking grooves  28  are located along a central longitudinal axis of each blade plate  20 .  
      The guide slots  26  each are sized to allow the catch block  164  to pass therethrough so that the blade plates  20  can be mounted to the support arms  14  by passing the catch blocks  164  through the guide slots  26  and then pushing the blade plates  20  along the longitudinal direction of the support arms  14  to let the locking posts  162  be engaged with the locking roves  28 . It is noted that a width of each locking groove  28  is sized to receive the locking post  162  and smaller than a width of each catch block  164  so that the blade plate  20  is not disengaged from the support arm  14  by the catch block  164 . Each of the locking posts  162  has two sides thereof which are clamped by two inner sides of the locking groove  28  corresponding thereto. Each of the blade plates  20  is positioned by partially clamped between the surface of each support arm  14  and the catch block  164 .  
      As shown in  FIG. 7 , the thin electrothermo strap  92  has one end thereof engaged with one of the positioning recesses  22  of one of the blade plate  20  and the positioning recess  22  is the one that is located close to the tubular base  20 . The other end of the thin electrothermo strap  92  is then positioned at one of the positioning recesses  22  of the adjacent blade plate  20 . By this way, the thin electrothermo straps  92  can be positioned to the same side of each of the blade plates  20  like a spider web. Another electrothermo strap  92  can also be positioned at the other side of each blade plate  20 .  
      As shown in  FIGS. 8 and 9 , when replacement of the blade plates  20  is needed, the damaged blade plate  20  is pulled toward the tubular base  12  along the longitudinal direction of the support arm  14  to shift the locking posts  162  out from the locking grooves  28 , and lift the blade plate  20  to pass the catch blocks  164  through the guide slots  26  to separate the blade plate  20  and the support arm  14 . The blade plate  20  is then pivoted about a center thereof to disengage the two thin electrothermo straps  92 ,  94  from the positioning recesses  22 . A new blade plate  20  can be connected to the support arm  14  by reversely proceeding the steps as mentioned above. Accordingly, each of the blade plates  20  is mounted on the respective support arm  14  of the main frame  10  easily and conveniently without needing aid of a tool,  
      As shown in  FIGS. 10 and 11 , multiple main frames  10 ′.  10 ″ can be connected with each other so as to increase the number of the thin electrothermo straps. Each of the tubular bases  12 ′,  12 ″ of the two main frames  10 ′.  10 ″ has a passage  122 ′/ 122 ″ defined axially therethrough and a first tube  124 ′/ 124 ″ and a second tube  126 ′/ 126 ″ extend from two sides of the tubular base  12 ′/ 12 ″ respectively. A connection tube  40 ′ has one end inserted into the first tube  124 ′ of the first main frame  10 ′ and the other end of the connection tube  40 ′ is mounted to the second tube  126 ″ of the tubular base  12 ″ of the second main frame  10 ″. It is noted that the second tube  126 ′/ 126 ″ has a tapered outer periphery so that the connection tube  40 ″ can be easily mounted thereto. A bolt  32 ′ extends through the two tubular bases  12 ′/ 12 ″ and the connection tube  40 ′, wherein the head  32 ′ is stopped by the jointed portion of the second tube  126 ′ and the passage  122 ′ of the first tubular base  12 ′ and the threaded end  34 ′ of the bolt  32 ′ is located in a space enclosed by the first tube  124 ″ of the second tubular base  12 ″. A nut  36 ′ is used to lock the threaded end  34 ′ of the bolt  32 ′ to connect the first and second main frames  10 ′.  10 ″.  
      The second embodiment of the present invention can carry more thin electrothermo straps  92 ,  94  without increasing the size of the main frame  10 . The total length of the thin electrothermo straps  92 ,  94  for the multiple main frames  10 ′.  10 ″ is longer than that on one single main frame  10 , so that the desired temperature can be easily achieved while each thin electrothermo strap needs only generate limited heat, thus prolonging the life term of the thin electrothermo straps.  
      Although the invention has been explained in relation to its preferred embodiments as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.