Patent Publication Number: US-9897264-B1

Title: Negative connecting terminal and negative connector for LED bulb drive board and lamp cap

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a power supply connection technique for an LED bulb, and more particularly, to a negative connecting terminal for an LED bulb drive board and a lamp cap and a negative connector. 
     2. Description of the Prior Art 
     In the prior art, the drive board of an LED bulb is connected with the positive and negative poles of a lamp cap by means of a wire connection. One end of the wire is welded to the drive board, and the other end of the wire is welded to the lamp cap, or the wire is hung on a lamp holder and then the lamp cap is locked to achieve the connection. Such a wire connection has a complex manufacturing, and its assembly efficiency is low, and the defeat rate is also high. 
     An electrical connecting terminal (including a positive connecting terminal  100 ′ and a negative connecting terminal  200 ′) for an LED bulb drive board and a lamp cap is developed by the inventor of this application. As shown in  FIG. 1  to  FIG. 4 , the electrical connecting terminal comprises a base plate  10 ′, an elastic sheet  20 ′, and an insertion pin  30  or a weld pin. The side of the base plate  10 ′ obliquely extends upward and forward and is bent to form the elastic sheet  20 ′ to be electrically connected with the poles (including a lamp cap positive pole  601 ′ and a lamp cap negative pole  602 ′) of a lamp cap  600 ′. The side of the base plate  10 ′ extends outward or is bent to form the insertion pin  30 ′ or the weld pin to be electrically connected with a drive board  700 ′. For a negative connector, the negative connecting terminal  200 ′ is mounted to a negative plastic core or mounted to an integrated plastic core  500 ′ (having the functions of a positive plastic core and a negative plastic core for installation of the positive connecting terminal  100 ′ and the negative connecting terminal  200 ′). The negative plastic core or the integrated plastic core  500 ′ is fixed to the drive board  700 ′, and is formed with a slot  504 ′. The outer wall of the slot  504 ′ is formed with a slope  505 ′ and a step  506 ′. 
     The base plate  10 ′ of the negative connecting terminal  200 ′ is securely inserted in the slot  504 ′ toward the LED bulb from the lamp cap. The insertion pin  30 ′ or the weld pin is exposed out of the negative plastic core or the integrated plastic core  500 ′ to be electrically connected with the drive board  700 ′. The elastic sheet  20 ′ extends out of the slot  504 ′ toward the inside of the LED bulb. A root portion  22 ′ and an inclined extension portion  21 ′ of the elastic sheet  20 ′ lean against the slope  505 ′ at the outer wall of the slot  504 ′. The slope  505 ′ provides a support for the elastic sheet  20 ′, thereby preventing the elastic sheet  20 ′ from being deformed to ensure electrical connection. The elastic sheet  20 ′ is elastically in contact with the lamp cap negative pole  602 ′ to achieve electrical connection. The head portion  23 ′ of the elastic sheet  20 ′ is hooked on the step  506 ′ at the outer wall of the slot  504 ′. 
     The positive connecting terminal  100 ′ and the negative connecting terminal  200 ′ of the above-described structure can be mounted on the drive board  700 ′ in advance by means of a corresponding plastic core (e.g., the integrated plastic core  500 ′) and then disposed in a lamp holder  800  along with the installation of the drive board  700 ′. When the lamp cap  600 ′ is installed, the lamp cap positive pole  601 ′ is inserted into a plastic core hole  502 ′ to be elastically in contact with the elastic sheet  20 ′ of the positive connecting terminal  100 ′ to achieve a positive electrical connection. The elastic sheet  20 ′ of the negative connecting terminal  200 ′ is compressed to get contact with the lamp cap negative pole  602 ′ to achieve a negative electrical connection. The connection process is simple, and the assembly efficiency is high, and the connection is stable, and the product yield is greatly improved. 
     However, the inventor further studies and finds that the negative connecting terminal needs improving. The elastic sheet  20 ′ of the negative connecting terminal  200 ′ directly obliquely extends upward and forward from the side of the base plate  10 ′ and is bent at the head portion  23 ′. The joint of the root portion  22 ′ of the elastic sheet  20 ′ and the base plate  10 ′ is hardly elastic. The inclined extension portion  21 ′ and the root portion  22 ′ lean against the slope  505 ′ at the outer wall of the slot  504 ′ when assembled. The elasticity mainly concentrates on the curved head portion  23 ′ of the elastic sheet  20 ′. The working stroke of the elastic sheet  20 ′ is smaller. (As shown in  FIG. 4 , the working stroke from the elastic sheet  20 ′ in broken lines to the elastic sheet  20 ′ in solid lines is short.) The elasticity of the elastic sheet  20 ′ is small. The elastic sheet  20 ′ is bent at the head portion  23  away from the base plate  10 ′, and there is no stress support during processing. The bending work is not easy. Accordingly, the present invention intends to provide a dual faucet structure for improving the shortcomings mentioned above. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide a negative connecting terminal for an LED bulb drive board and a lamp cap. The negative connecting terminal is simple in structure and more flexible and has a greater working stroke and can be processed more easily. 
     According to one aspect of the present invention, a negative connecting terminal for an LED bulb drive board and a lamp cap is provided. The negative connecting terminal comprises a base plate, an elastic sheet, and a drive terminal. A side of the base plate is formed with the elastic sheet to be electrically connected with a lamp cap negative pole. The elastic sheet is bent from the side of the base plate to form a small curved portion having an opening facing rearward and then bent again to form a big curved portion having an opening facing forward, and obliquely extends forward to form an oblique extension portion, and finally is bent to form a head portion. The side of the base plate extends outward to form the drive terminal to be electrically connected with a drive board. The drive terminal is an insertion pin extending outward from the side of the base plate, alternatively, the drive terminal is a weld pin bent outward from the side of the base plate. 
     Preferably, the base plate is in the form of a frame (such as a   shape or in a □ shape). 
     Preferably, the small curved portion and the large curved portion of the elastic sheet each have an arc shape. The small curved portion, the large curved portion, and the oblique extension portion each have a middle reinforcing rib. 
     According to another aspect of the present invention, a negative connector for an LED bulb drive board and a lamp cap is provided. The negative connector comprises a plastic core and the aforesaid negative connecting terminal. The plastic core is fixed to the drive board. The plastic core is formed with a slot. An outer wall of the slot is formed with a recess. The base plate of the negative connecting terminal is securely inserted into the slot. The insertion pin or the weld pin is exposed out of the plastic core to be electrically connected with the drive board. The elastic sheet extends out of the slot. The small curved portion is located in the recess. The head portion of the elastic sheet is elastically in contact with the lamp cap negative pole for electrical connection. 
     Preferably, the outer wall of the slot is formed with a slope. 
     The present invention has a simple structure. The small curved portion and the large curved portion are provided between the root portion of the elastic sheet and the base plate to increase the elasticity of the root portion of the elastic sheet, so that the elasticity of the whole elastic sheet is also increased. When the elastic sheet is mounted to the plastic core, the slot of the plastic core protects the small curved portion, and the big curved portion cooperates with the small curved portion, enabling the working stroke of the elastic sheet to become larger. The main bending of the elastic sheet is at the root portion. The root portion is close to the base plate. The base plate provides a native bending stress support, so that the bending process is easier. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a conventional positive connecting terminal; 
         FIG. 2  is a perspective view of a conventional negative connecting terminal; 
         FIG. 3  is a side view of the conventional negative connecting terminal; 
         FIG. 4  is a sectional view of the conventional positive and negative connecting terminals mounted to an LED bulb by means of an integrated plastic core; 
         FIG. 5  is a perspective view of the negative connecting terminal of the present invention; 
         FIG. 6  is a side view of the negative connecting terminal of the present invention; 
         FIG. 7  is a perspective view of the plastic core of the present invention; 
         FIG. 8  is a perspective view of the negative connector of the present invention; and 
         FIG. 9  is a sectional view of the present invention applied to an LED bulb. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings. 
     As shown in  FIG. 5  to  FIG. 9 , the present invention discloses a negative connecting terminal  200  for an LED bulb drive board and a lamp cap. The negative connecting terminal  200  comprises a base plate  10 , an elastic sheet  20 , and an insertion pin  30  or a weld pin. 
     The base plate  10  may be a single plate or in the form of a frame (generally in a   shape or in a □ shape). In order to increase the firmness of installation, the base plate  10  is formed with a raised rib  11 . 
     One side of the base plate  10  is formed with the elastic sheet  20 . The elastic sheet  20  is adapted to be electrically connected with a lamp cap negative pole  602 . The elastic sheet  20  is first bent from the side of the base plate  10  to form a small curved portion  21  having an opening facing rearward and then bent again to form a big curved portion  21  having an opening facing forward, and obliquely extends forward to form an oblique extension portion  23 , and finally is bent to form a head portion  24 . In order to make the stress more uniform and to make the elasticity better, the small curved portion  21  and the large curved portion  22  of the elastic sheet  20  are each designed in an arc shape. The small curved portion  21 , the large curved portion  22 , and the oblique extension portion  23  are provided with a middle reinforcing rib  25 . 
     The side of the base plate  10  extends outward or is bent to form the insertion pin  30  or the weld pin. The insertion pin  30  is adapted for electrical connection with a drive board  700 . The weld pin is welded to the drive board  700  to achieve electrical connection. 
     When the negative connecting terminal  200  is electrically connected with the drive board  700  and the lamp cap  600 , the negative connecting terminal  100  and a positive connecting terminal  100  may be mounted by means of respective plastic cores or by means of a common plastic core. The present invention further discloses a negative connector  400 . The negative connector  400  comprises a plastic core  300  and the aforesaid negative connecting terminal  200 . The plastic core  300  is fixed to the drive board  700 . The plastic core  300  is formed with a slot  301 . An outer wall of the slot  301  is formed with a recess  302 . 
     The base plate  10  of the negative connecting terminal  200  is securely inserted into the slot  301  in the direction of the LED bulb from the lamp cap  600 . The insertion pin  30  or the weld pin is exposed out of the plastic core  300  for electrical connection with the drive board  700 . The elastic sheet  20  extends out of the slot  301 . The small curved portion  21  is located in the recess  302 . The slot  301  functions to protect the small curved portion  21 . The head portion  24  of the elastic sheet  20  is elastically in contact with the lamp cap negative pole  602  for electrical connection. The outer wall of the slot  301  is further formed with a slope  303 . When the elastic sheet  20  is deformed at the maximum, the oblique extension portion  23  will lean against the slope  303  to provide a support for the elastic sheet  20 , thereby preventing the elastic sheet  20  from being deformed to ensure electrical connection. 
     The present invention has a simple structure. The elasticity of the root portion of the elastic sheet  20  is increased through the small curved portion  21  and the large curved portion  22 , so that the elasticity of the whole elastic sheet  20  is also increased. When the elastic sheet  20  is mounted to the plastic core  300 , the working stroke of the elastic sheet  20  becomes larger. As shown by the dotted lines in  FIG. 9 , the working stroke of the elastic sheet  20  of the present invention is significantly larger than the working stroke of the elastic sheet  20 ′ as shown in  FIG. 4 . The main bending of the elastic sheet  20  is at the root portion (formed with the small curved portion  21  and the large curved portion  22 ). The root portion is close to the base plate  10 . The base plate  10  provides a native bending stress support, so that the bending process is easier. 
     The structure and installation of the positive connecting terminal  100  may be the same as those of the prior art, or may be other modifications. Although particular embodiments of the present invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be limited except as by the appended claims.