Patent Document

BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to wire terminal blocks, and more particularly to a terminal block assembly where electrical leading wires are inserted and connected. The inventive terminal block assembly features for a combination of a lever member, a buckle and a metal spring piece that can be operated in an effort-saving manner to crimp or release a leading wire inserted into the terminal block assembly. 
     2. Description of Related Art 
     A terminal (block) or a crimp terminal (block) using a metal piece or a metal spring piece covered by an insulating housing (typically made of plastic) to crimp a leading wire inserted therein and thereby form electrical connection is known. 
     Such a connecting terminal designed be inserted onto a circuit board (such as a PC circuit board) has an insulating housing that is provided with a through hole or an wire inlet, through which a leading wire can be inserted to the interior of the housing. The housing defines therein a chamber for receiving a metal spring piece as described previously, so as to form contact or electrical connection with the leading wire inserted into the housing. The metal spring piece has a head, serving to crimp the leading wire inserted into the housing so as to prevent the leading wire from disconnecting form the metal spring piece or leaving the insulating housing. The established connection between the leading wire and the metal spring piece can be only dismissed when the head is pushed by a tool accessing it from the exterior of the housing. 
     Basically, the metal spring piece is connected to a terminal pin that is formed symmetrical and narrow, so as to be inserted onto and become electrically conductive with the circuit board. 
     The prior art also discloses an approach to controlling such a metal spring piece to crimp or release a leading wire by providing a terminal block or a connecting terminal with a lever member. For example, a prior art has proposed a reasonable embodiment, wherein a metal spring piece spans over two sides of a lever member with a forked head, for bearing and responding to operation of the lever member. In other words, when the lever member is operated to press the metal spring piece downward, it forces the tail of the metal spring piece to go downward and engage with a leading wire inserted into the terminal block. When the lever member is operated oppositely, its end pushes the forked head of the metal spring piece in the manner that the tail of metal spring piece raises and the crimped leading wire is now released. 
     In the foregoing prior art device, for ensuring that the tail of the metal spring piece can firmly secure the leading wire entering the terminal block without the risk of unintentionally disengagement, the forked head of the metal spring piece is provided with a curved segment and a pair of slender arms are extended from the upper portion of the terminal pin corresponding to the curved segment. When the lever member presses the metal spring piece&#39;s forked head, the curved segment is pushed toward and get grasped by or engaged with the arms. When the lever member is pushed upward, it drives the curved segment to get away from the arms, so as to dismiss the engagement and release the leading wire. 
     One issue about such a terminal block or connecting terminal in terms of structural design and application is that for endowing the curved segment with structural strength sufficient for the engagement with the arms of the terminal pin and thus preventing deformation that degrades the engagement between the metal spring piece and the leading wire over time, the curved segment in practice is made as a U-shaped structure. However, the specially processed structure can significantly increase the complexity and cost level for manufacturing the metal spring piece. 
     Another issue about such a terminal block or connecting terminal in terms of structural design and application is that for ensuring good electrical conductivity, the terminal pin is usually made of a metal material containing cooper (e.g. brass or the like) and thus is less rigid. This makes the terminal pin show inferior structural strength when its arms engage with the curved segment of the metal spring piece. Particularly, after long-term operation, the arms tend to deform and become unreliable for the intended engagement. While this problem may be solved by increasing the thickness or area of the arms, the consequent high complexity and costs are adverse to the relevant manufacturers. 
     Briefly, the aforementioned references do propose some ideas about the design and combination of connecting terminals/terminal blocks, lever members, metal spring pieces, and terminal pins. It is thus believed that by rearranging and recombining these components, a novel approach superior to the existing devices can be devised to improve the structure, structural strength, utility and thereby applications of a terminal block while minimizing the manufacturing cost and potential deformation. 
     Apart from overcoming the above-mentioned issues, a preferred terminal block shall satisfy some more expectancies. For instance, with the overall capability and reliability of the crimp and engagement ensured, it is preferred that the operation of the lever member is effort-saving. Also, it is preferred that the structural complexity of the terminal block, the lever member, the metal spring piece and the terminal pin is further improved. These have been neither mentioned nor disclosed in the previously discussed references. 
     SUMMARY OF THE INVENTION 
     In view of this, the primary objective of the present invention is to provide a terminal block assembly, which is a combination of a terminal block and a lever member pivotally connected to the terminal block and is less structurally complicated and less likely to deform as compared to the existing terminal block products. The terminal block comprises a main body and a chamber defined by the main body. The chamber receives therein a metal spring piece for in response to the lever member&#39;s movement to crimp and electrically connect a leading wire or release the leading wire. A buckle is also installed in chamber such that it is allowed to perform reciprocating movements. The buckle is equipped with a spring that makes the buckle normally engage with the lever member until it receives an operating force that cancel the established engagement. Thereby, the disclosed terminal block assembly is easy and convenient to operate. 
     According to the present invention, when the lever member has a socket and a retaining portion formed in the socket corresponding to the buckle. When the lever member is operated (pressed downward) to make the metal spring piece crimp a leading wire entering the terminal block, the lever member&#39;s retaining portion first pushes the buckle into the socket to engage with the retaining portion, thereby ensuring that the metal spring piece crimps the leading wire firmly. 
     According to the present invention, the buckle has a pivotal end and a free end. The pivotal end is connected to the main body, so that the buckle&#39;s free end is allowed to rock into the lever member&#39;s socket to engage with the retaining portion, or rock out when pushed away by the lever member&#39;s retaining portion and dismiss the engagement. 
     According to the present invention, the buckle and the spring are jointly assembled to the main body. The spring has a first end and a second end. The first end abuts against the main body, while the second end abuts against a back of the buckle so as to make the buckle normally stay at a position it engages with the lever member&#39;s retaining portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a terminal block assembly according to the present invention. 
         FIG. 2  is an exploded view of the terminal block assembly of  FIG. 1 , showing its main body, lever member, metal spring piece, buckle and terminal pin particularly. 
         FIG. 3  is a cross-sectional view of the terminal block assembly of the present invention, showing relation between the lift lever member and the metal spring piece. 
         FIG. 4  is a cross-sectional view of the terminal block assembly, showing that the pressed lever member makes the metal spring piece crimp a leading wire and the retaining portion pushes the buckle&#39;s free end away. 
         FIG. 5  is a cross-sectional view of the terminal block assembly, showing the engagement between the lever member&#39;s retaining portion and the buckle&#39;s free end. 
         FIG. 6  is a schematic drawing showing the acting force distribution cross the lever members retaining portion and the buckle&#39;s free end. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 ,  2  and  3 , according to the present invention, a terminal block assembly comprises a main body made of an insulating material, and a lever member, which are denoted throughout the figures by numerals  10  and  20 , respectively. The main body  10  defines therein a chamber  11 . The chamber  11  has a metal spring piece  30  and a terminal pin  40  installed therein. The terminal pin  40  is inserted onto a circuit board (e.g. a PUB). The main body  10  also comprises a wire inlet  12  communicated with the chamber  11 , so that a leading wire  50  can be inserted into the chamber  11  through the wire inlet  12  and get crimped by the metal spring piece  30 , thereby forming electrical connection with the terminal pin  40 . 
     In the illustrated embodiment, the metal spring piece  30  is configured to move in response to the operation of the lever member  20  to crimp and have electrical connection with the leading wire  50 , or release the leading wire  50 . Particularly, the lever member  20  comprises a pivotal end  21  and an operational end  22 . The pivotal end  21  is pivotally connected to the main body  10  or the wall of the chamber  11 , so as to enable the operational end  22  to perform reciprocating movements. The pivotal end  21  is provided with a recess  23 , and also a pressing portion  24  and a pushing portion  25  that are connected to and jointly define the recess  23 . 
     As shown, the metal spring piece  30  has a head  31  and a tail  32 . The head  31  is configured to be received in the recess  23 , so that when the pressing portion  24  of the lever member  20  presses the head  31  of the metal spring piece  30  downward, the tail  32  crimps or engages with the leading wire  50  entering the chamber  11 , and when the pushing portion  25  pushes the head  31 , the tail  32  releases the leading wire  50  from the retained state, as described in detail below. 
     In a preferred embodiment, in the chamber  11 , there is also a buckle  60  that can perform reciprocating movements. The buckle  60  is biased by a spring  70  to normally engage with the lever member  20 . 
     In the illustrated embodiment, a socket  26  and a retaining portion  27  formed in the socket  26  are provided on the lever member  20  between the pivotal end  21  and the operational end  22  or near the operational end  22 . The retaining portion  27  defines an inlet  28  for the socket  26 . The buckle  60  and the spring  70  are such assembled into the chamber  11  of the main body  10  that they correspond to the socket  26  and the retaining portion  27  of the lever member  20 . 
       FIGS. 2 and 3  depict the buckle  60  as comprising a pivotal end  61  and a free end  62 . The pivotal end  61  (including a hole  63  and the spring  70  are combined by a post  13  of the main body chamber  11 , so that the free end  62  of the buckle  60  is allowed to rock into the lever member&#39;s socket  26  to get engaged with the retaining portion  27 , or rock out when pushed away by the retaining portion  27  of the lever member  20  to cancel the foregoing engagement. 
     In a practicable embodiment, the spring  70  has a first end  71  and a second end  72 . The first end  71  abuts against the main body  10 , while the second end  72  is a bent portion perpendicularly extending from the spring  70  and abuts against a back  64  of the buckle  60 , so as to bias the buckle  60  to normally engage with the lever member&#39;s retaining portion  27 . 
     Please refer to  FIG. 3 , wherein the lever member  20  is lift to an open position. As shown, the pushing portion  25  of the lever member  20  pushes the head  31  of the metal spring piece  30  upward, so as to position the tail  32  as shown in the drawing. At this time, the leading wire  50  cart be inserted into the chamber  11  through the wire inlet  12 . When the lever member  20  is pressed down to a close position, or the position as shown in  FIG. 4 , the pressing portion  24  pressed the head  31  of the metal spring piece  30 , and in turn makes the tail  32  to rock downward to a lower position as shown, where it crimps the leading wire  50  entering the main body  10  or the chamber  11 . 
     As shown in  FIG. 4 , when the retaining portion  27  of the lever member  20  reaches the buckle&#39;s free end  62 , the retaining portion  27  first pushes the free end  62  of the buckle  60  away, so that the buck  64  of the buckle  60  pushes the spring&#39;s second end  72 , thereby forcing the spring  70  to deform and accumulate energy. 
     Referring to  FIG. 5 , when the detaining portion  27  passes the buckle&#39;s free end  62 , the spring  70  releases the energy it accumulates when deforming, and forces the free end  62  to return to the socket  26 , where the free end  62  engages with the lever member&#39;s retaining portion  27 . At this time, the metal spring piece&#39;s tail  32  crimps the leading wire  50  firmly. 
     It is to be understood that when applying an operating force to lift the lever member  20  and make the retaining portion  27  push the free end  62  of the buckle  60  away to dismiss the engagement, a user shall push the lever member  20  toward its open position as shown in  FIG. 3 , so that the pushing portion  25  pushes the head  31  of the metal spring piece  30  upward, which in turn drives the tail  32  to move upward, thereby freeing the metal spring piece&#39;s tail  32  from crimping the leading wire  50  and cancelling the engagement. 
     Still referring to  FIG. 5 , it is to be noted that by defining a distance between the lever member&#39;s operational end  22  and pivotal end  21  as L1, a distance between the retaining portion  27  or the buckle&#39;s free end  62  and the pivotal end  21  as L2, a distance between the pressing portion  24  and the pivotal end  21  as length L3, requirements of the disclosed terminal block assembly can be expressed as: L1&gt;L2&gt;L3; and that L1 is approximately equal to 4×L3 to 5×L3 while L2 is approximately equal to 3×L3 to 4×L3 (i.e. 3.5×L3). Assuming that the force the pressing portion  24  uses to press the metal spring piece&#39;s head  31  downward is F, the minimum force the user may use to operate the lever member at its operational end  22  is only 1/5×F. 
     Referring to  FIG. 6 , since the lever member&#39;s retaining portion  27  or the buckle&#39;s free end  62  is away from the lever member&#39;s pivotal end  21  a distance L2 (namely 3.5×L3), it means that an engaging force or total acting force by which the retaining portion  27  engages with the buckle&#39;s free end  62  is 1/3×F to 1/4×F (e.g. 1/3.5×F). 
       FIG. 6  particularly illustrates that the engaging force or total acting force (1/3.5×F) is composed of a horizontal component and a vertical component. The horizontal component is equal to a half of the engaging force or total acting force, i.e. 1/7×F. 
     In other words, when lilting the lever member  20  as mentioned previously, the user needs only to exert an operating force of 1/7×F to make the retaining portion  27  push the free end  62  of the buckle  60  toward the right of the drawing and dismiss the engagement. Thus, the operation is easy and effort-saving. 
     Representatively, in addition to allowing easy and reliable operation, the disclosed terminal block assembly is superior to the existing devices for the following advantages. 
     First, the terminal and the associated components the lever member  20  having the socket  26  and the retaining portion  27  to work with the free end  62  of the buckle  60 ; the spring second end  72  abutting against the back  64  of the buckle  60  to make the buckle  60  normally stay at its engaged position; and the arrangement among the lever member  20 , the metal spring piece  30  and the buckle  60 ) have been reconsidered and redesigned in terms of usage and structure, and are different from the conventional schemes. This allows the disclosed terminal block assembly to be more adaptive and applicable. With the overall capability and reliability of the crimp and engagement ensured, the disclosed terminal block assembly has improved structural strength and operational convenience as compared to the prior art. 
     Second, the disclosed approach eliminates the use of the slender arms on the terminal pin for working with the curved segment of the metal spring piece&#39;s head as implemented in the aforementioned prior-art device, thereby being free from the shortcomings about unwanted part deformation, inferior engagement, and high complexity as well as costs for manufacturing. 
     Third, it is to be noted that in the known approach for making the terminal pin&#39;s arms to release the curved segment of the metal spring piece&#39;s head they grasp and cancelling an established engagement, a user has to exert a quite large operating force (greater than 1/5×F). As comparison, in the present invention, the retaining portion  27  only needs a force of 1/7×F to push the buckle  60  away and achieve disengagement. Thus, the configuration and combination of the lever member  20 , the metal spring piece  30 , the buckle  60 , and the spring  70  directly contribute to the claimed effort-saving operation. 
     To further explain, the particular conventional device has the engagement between the curved segment on the metal spring piece&#39;s head and the terminal pin&#39;s arms realized on an axis perpendicular to the lever member&#39;s pivotal end. Assuming that the engaging force between the curved segment and the arms is F (which in practice is usually greater than two times of the aforementioned a user has to exert a force of at least 1/5×F for disengagement, much greater than that required between the lever member&#39;s retaining portion  27  and the buckle&#39;s free end  62  (namely the horizontal component as discussed above). Thus, the present invention provides great operational convenience. To sum up, the present invention provides an effective terminal block assembly that has novel configuration and possess various advantageous that unseen in the prior art. 
     The present invention has been described with reference to the preferred embodiments and it is understood that the embodiments are not intended to limit the scope of the present invention. Moreover, as the contents disclosed herein should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present invention should be encompassed by the appended claims.

Technology Category: 5