1. Field of the Invention
The present invention relates to a connector terminal including at opposite ends thereof a pair of press-fit terminals to be inserted into through-holes formed through each of two printed circuit boards located facing each other, to thereby electrically connect the two printed circuit boards to each other. The present invention relates further to a connector housing suitable to the connector terminal.
2. Description of the Related Art
There is known an electric connector holding a plurality of connector terminals in a line. The connector terminals are inserted at one of ends thereof into through-holes formed through a first printed circuit board, and at the other end thereof into through-holes formed through a second printed circuit board, to thereby electrically connect circuits mounted on the first and second printed circuit boards to each other.
The illustrated connector 100 includes a housing 110, and a plurality of post contacts 120. The connector 100 electrically connects printed circuit boards 101 and 102 (see
The illustrated pin header 200 includes a plurality of connector terminals 201, and a connector holder. The connector holder includes a board 202, an upper bar 203 horizontally extending along an upper end of the board 202, a lower bar 204 horizontally extending along a lower end of the board 202, and a plurality of protrusions 205 horizontally aligned at a middle of the boards 202. The connector terminals 202 are supported by the upper bar 203 and the lower bar 204. The protrusions 205 are located in gaps formed between the adjacent connector terminals 201 to thereby electrically insulate the adjacent connector terminals 201 to each other.
In an electric connector including a plurality of connector terminals through which printed circuit boards are electrically connected to each other, a positional relation between the printed circuit boards is important. For instance, when connector terminals are inserted at opposite ends thereof into through-holes formed through printed circuit boards, to thereby electrically connect the printed circuit boards to each other, if a positional relation between the printed circuit boards were displaced, the connector terminals might be able to be inserted at one of ends thereof into through-holes of one of the printed circuit boards, but could not be inserted at the other end thereof into through-holes of the other of the printed circuit boards, because axes of the connector terminals are displaced relative to axes of the through-holes. In particular, in the case that a plurality of electric connectors is employed, it is much afraid that connector terminals cannot be inserted into one of printed circuit boards. Furthermore, if connector terminals were designed to have a smaller cross-sectional area in order to allow the connector terminals to be much resiliently deformable, the connector terminals would allow a less current to pass therethrough.
In the connector 100 illustrated in
In the pin header 200 illustrated in
In view of the above-mentioned problems in the conventional connectors, it is an object of the present invention to provide a connector terminal capable of being inserted into printed circuit boards, even if there were a gap between axes of the connector terminals and axes of through-holes formed through the printed circuit boards. It is further an object of the present invention to provide a connector housing suitable to the above-mentioned connector terminal.
In one aspect of the present invention, there is provided a connector terminal including at opposite ends a pair of press-fit terminals to be inserted into through-holes formed through two printed circuit boards located facing each other, each of the press-fit terminals including a plurality of contact pieces, the connector terminal further including at least one buffer portion deformable in accordance with a gap between imaginary longitudinal center lines of the press-fit terminals.
In the connector terminal in accordance with the present invention, even if there were a gap in a positional relation between two printed circuit boards, the buffer portion is deformed in accordance with a gap formed between longitudinal center lines of the press-fit terminals to thereby prevent an excessive stress caused by the gap from acting on the press-fit terminals. Consequently, after one of the press-fit terminals was inserted into one of printed circuit boards, the other of the press-fit terminals can be inserted into the other of printed circuit boards without problems.
It is preferable that the buffer portion includes a plurality of resilient pieces. Each of the resilient pieces is deformable in accordance with a gap between imaginary longitudinal center lines of the press-fit terminals, and allows even a much current to pass therethrough.
It is preferable that the buffer portion further includes a pair of binders each binding the resilient pieces at one of opposite ends of the resilient pieces, each of the binders bending so as to surround the resilient pieces therewith. The binders are able to bind the resilient pieces in a U-shape, a C-shape or an arcuate shape. Thus, the resilient pieces can be uniformly bent at an entirety in any direction with rigidity thereof being ensured.
It is preferable that the resilient pieces are equal in width to one another. By designing the resilient pieces to have a common width, the resilient pieces can be deformed at any position, and further, can be smoothly deformed at an entirety.
It is preferable that the resilient pieces are collected at ends thereof in the vicinity of and in parallel with the imaginary longitudinal center lines. The resilient pieces can be deformed more readily than resilient pieces arranged to be separated from one another, ensuring that the buffer portion comprising the resilient pieces can be easily deformed.
It is preferable that the buffer portion has a length equal to or greater than a width thereof.
It is preferable that the buffer portion has a width longer than a length.
It is preferable that the connector terminal further includes at least one projecting portion located between the press-fit terminals, the projecting portion projecting beyond the press-fit terminals in a width-wise direction of the connector terminal.
It is preferable that the connector terminal further includes two projecting portions located between the press-fit terminals, each of the projecting portions projecting beyond the press-fit terminals in a width-wise direction of the connector terminal, one of the projecting portions having a length greater than the same of the other of the projecting portions in a length-wise direction of the connector terminal.
It is preferable that the projecting portion is formed of a thin resilient metal plate.
It is preferable that the buffer portion is formed of a thin resilient metal plate. Even if the imaginary longitudinal center lines are displaced to each other in a thickness-wise direction of the resilient metal plate, the buffer portion can accomplish its performance by deforming the resilient metal plate.
In another aspect of the present invention, there is provided a connector housing including a pair of holders detachably holding a plurality of connector terminals in a line, each of the connector terminals defining the above-mentioned connector terminal, wherein the holders are spaced away from each other in a length-wise direction of the connector terminals, and one of the holders holds the connector terminals in a non-fixed condition, and the other holds the connector terminals in a fixed condition.
In the connector housing in accordance with the present invention, since the connector terminals are held by one of the holders in a non-fixed condition, even if there were a gap in a positional relation between printed circuit boards, the press-fit terminals can be moved towards and be inserted into through-holes of the corresponding printed circuit board.
It is preferable that each of the holders includes a pair of arms spaced away from each other and extending in parallel with each other, and a pair of wedges each formed at a leading edge of each of the arms, the connector terminal can be inserted into a space formed between the arms through an open space formed between the wedges, and each of the holders has a resilient force causing the arms to draw each other.
Inserting a connector terminal into an open space formed between the wedges, the wedges are resiliently deformed to thereby hold the connector terminal therebetween by virtue of the resilient force of the holders.
It is preferable that a distance between the arms in the one of the holders holding the connector terminal in a non-fixed condition is set to such a distance that at least one of the arms does not make contact with the connector terminal when the connector terminal is inserted between the arms, and a distance between the arms in the other of the holders holding the connector terminal in a fixed condition is set to such a distance that both of the arms make contact with the connector terminal when the connector terminal is inserted between the arms.
By designing the distances between the arms and the holders in the above-mentioned manner, a connector terminal can be held by the holders in a fixed or non-fixed condition.
It is preferable that the connector housing further includes a projection projecting towards the wedges in a space formed between the arms in each of the holders, the projection in the one of the holders holding the terminal connector in a non-fixed condition has such a length that the projection does not make contact with the connector terminal when the connector terminal is inserted between the arms, and the projection in the other of the holders holding the terminal connector in a fixed condition has such a length that the projection makes contact with the connector terminal when the connector terminal is inserted between the arms.
The projections assist the holders for holding connector terminals in a fixed or non-fixed condition.
In still another aspect of the present invention, there is provided a connector housing including a pair of holders detachably holding a plurality of connector terminals in a line, each of the connector terminals defining the above-mentioned connector terminal including the projecting portion, wherein the holders are spaced away from each other in a length-wise direction of the connector terminals, one of the holders holds the connector terminals in a non-fixed condition, and the other holds the connector terminals in a fixed condition, and the projecting portion makes abutment in each of the holders with edges extending perpendicularly to a length-wise direction of the connector terminal.
The advantages obtained by the aforementioned present invention will be described hereinbelow.
In accordance with the present invention, even if there were a gap in a positional relation between printed circuit boards, the press-fit terminals can be surely inserted into the printed circuit boards, because the gap is absorbed into the buffer portion, and thus, one of the press-fit terminals can be brought to through-holes of the corresponding printed circuit board, ensuring that the printed circuit boards can be surely connected to each other through the connector terminals with the connector terminals being allowed to have a necessary strength and allowing a much current to pass therethrough.
The above and other objects and advantageous features of the present invention will be made apparent from the following description made with reference to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the drawings.
An electric connector in accordance with the first embodiment of the present invention is explained hereinbelow with reference to the drawings.
The electric connector 10 in accordance with the first embodiment, illustrated in
The electric connector 10 includes a plurality of connector terminals 20 each in the form of a bar, and a connector housing 30 supporting the connector terminals 20 in a line.
Each of the connector terminals 20 illustrated in
The connector terminal 20 can be manufactured by bending a single metal plate 210 having resiliency, illustrated in
Each of the first and second press-fit terminals 21a and 21b can be connected to the printed circuit boards P1 and P2 without being soldered. As illustrated in
As illustrated in
The first projecting portion 22a located closer to the printed circuit board P1 (see
Since the first and second projecting portions 22a and 22b are formed of a resilient thin metal plate, they can accomplish the same performance as that of the buffer portion 23.
The buffer portion 23 is located at a center of the connector terminal 20 between the first and second press-fit terminals 21a and 21b. As illustrated in
The buffer portion 23 including a plurality of the resilient pieces 231 is preferably designed to have a length at least twice greater than a thickness thereof in order to be readily resiliently deformable.
As illustrated in
In the first embodiment, the three resilient pieces 231 are connected to the binders 232 and 233 such that the resilient pieces 231 are bound with being located close to one another. Hence, each of the three resilient pieces 231 makes contact with each of three inner walls of the U-shaped binders 232 and 233.
For instance, in the case that the buffer portion 23 includes four or five resilient pieces 231, the binders 232 and 233 may be designed to have a rectangular or pentagonal cross-section, respectively. As an alternative, the binders 232 and 233 may be designed to be C-shaped or arcuate. It is preferable in such cases that the resilient pieces 231 are bound such that they are located at the opposite ends 231a thereof close to the imaginary longitudinal center lines L, and extend in parallel with the imaginary longitudinal center lines L.
Hereinbelow is explained a process of manufacturing the connector terminal 20, with reference to
The connector terminal 20 is manufactured by bending a single thin metal plate 210 illustrated in
First, each of the shaft portions 211 located at the opposite ends of the metal plate 210 is bent about the imaginary longitudinal center line L so as to have a U-shaped cross-section. Then, the U-shaped shaft portion 211 is bent by 180 degrees towards the contact portion 213 about a line 241 horizontally extending between the shaft portion 211 and the contact portion 213.
Then, the binders 214 and 215 extending in a direction perpendicular to the imaginary longitudinal center line L and defining outer edges of the contact portion 213 are bent into a C-shape, and the contact pieces 212 extending in parallel with the imaginary longitudinal center line L are bent into a barrel shape such that the resultant contact portion 213 surrounds the shaft portion 211.
After a folding line is brought into the opposite ends 231a with central areas of the resilient pieces 231 being kept straight, the binders 232 and 233 extending in a direction perpendicular to the imaginary longitudinal center line L and defining outer edges of the buffer portion 23 are bent into a U-shape to thereby bind therewith the resilient pieces 231 extending in parallel with the imaginary longitudinal center lines L.
Thus, there is completed the connector terminal 20 illustrated in
The resilient pieces 231 in a developed condition are designed to be equal in width to one another, equally spaced away from one another, and extend in parallel with one another, as illustrated in
As illustrated in
The support plate 31 extends between the legs 34, and is rectangular in shape.
The first and second holders 32a and 33b are formed on the support plate 31, and equally spaced away from one another. Each of the first and second holders 32a and 32b includes a pair of claws 321, and a pair of guide walls 322 (see
Each of the claws 321 includes a pair of arms 321a extending from the support plate 31, and being resiliently deformable when the connector terminal 20 is inserted thereinto, and a pair of wedges 321b formed at a distal end of each of the arms 321a, and being tapered such that a distance therebetween is greater at a location remoter from the support plate 31. Between the arms 321a is formed a rectangular space R in which the connector terminal 20 is housed.
As illustrated in
As illustrated in
In contrast, as illustrated in
Each of the projections 33 projects in the space R from the support plate 31 towards the wedges 321b between the arms 321a.
As illustrated in
As illustrated in
The legs 34 are formed at opposite ends of the support plate 31. Being inserted into through-holes (not illustrated) formed through the printed circuit boards P1 and P2, the legs 34 fix the connector housing 30 between the printed circuit boards P1 and P2, keeping a space uniform between the printed circuit boards P1 and P2, and prevent the connector terminals 20 from being longitudinally damaged.
As illustrated in
The electric connector 10 in accordance with the first embodiment, having the above-mentioned structure, is used as follows.
First, as illustrated in
Even if a stress acts on the connector terminals 20 in a direction of the imaginary longitudinal center lines L when the second press-fit terminals 21b are inserted into the through-holes of the printed circuit board P2, since the second projecting portion 22b engages with the claws 321, the connector terminals 20 are restricted from moving in a direction of the imaginary longitudinal center lines L. Consequently, the connector terminals 20 cannot move in a direction of the imaginary longitudinal center lines L, and thus, the second press-fit terminals 21b can be surely inserted into the through-holes of the printed circuit board P2.
Then, locating the printed circuit board P1 above the electric connector 10, the second portions 342 (upper ones in
As illustrated in
Even if a positional relation between the printed circuit boards P1 and P2 were not in accuracy, that is, even if the through-holes of the printed circuit board P1 do not align with the through-holes of the printed circuit board P2, since the connector terminals 20 are held in a non-fixed condition in the spaces R of the first holders 32a, as illustrated in
If the connector terminal 20 is inserted into the printed circuit boards P1 and P2 with a positional relation between the printed circuit boards P1 and P2 not being in accuracy, the imaginary longitudinal center lines L of the first and second press-fit terminals 21a and 21b are not in alignment with each other.
However, the resilient pieces 231 (see
For instance, if the through-holes of the printed circuit board P1 into which the first press-fit terminals 21a are inserted deviate backwardly (that is, towards the support plate 31) relative to the thorough-holes of the printed circuit board P2, as illustrated in
If the through-holes of the printed circuit board P1 into which the first press-fit terminals 21a are inserted deviate forwardly (that is, in an opposite direction against the support plate 31) relative to the thorough-holes of the printed circuit board P2, as illustrated in
If the through-holes of the printed circuit board P1 into which the first press-fit terminals 21a are inserted deviate to the left relative to the thorough-holes of the printed circuit board P2, as illustrated in
If the through-holes of the printed circuit board P1 into which the first press-fit terminals 21a are inserted deviate to the right relative to the thorough-holes of the printed circuit board P2, as illustrated in
As mentioned above, even if the through-holes of the printed circuit boards P1 and P2 deviate forwardly, backwardly or to the left or right relative to each other, the buffer portion 23 can absorb the deviation therein, and hence, the connector terminals 20 can be inserted into the printed circuit boards P1 and P2.
In particular, since the resilient pieces 231 are bound at the opposite ends 321a thereof in the vicinity of and in parallel with the imaginary longitudinal center lines L, the resilient pieces 23 can be readily resiliently deformed relative to the case that the resilient pieces are separated away from one another, ensuring the buffer portion 23 to be readily deformed.
Even if a stress acts on the connector terminals 20 in a direction of the imaginary longitudinal center lines L when the first press-fit terminals 21a are inserted into the through-holes of the printed circuit board P1, since the first projecting portion 22a engages with the claws 321 of the first holder 32a, the connector terminals 20 are restricted from moving in a direction of the imaginary longitudinal center lines L. Consequently, since the connector terminals 20 cannot move in a direction of the imaginary longitudinal center lines L even if the connector terminals 20 are held in a non-fixed condition in the spaces R of the first holders 32a, the first press-fit terminals 21a can be surely inserted into the through-holes of the printed circuit board P1.
As mentioned above, the first press-fit terminals 21a can be inserted into the through-holes of the printed circuit board P1 without any problems with the second press-fit terminals 21b being inserted into the through-holes of the printed circuit board P2.
In particular, when the through-holes formed through the printed circuit boards P1 and P2 in a plurality of lines in parallel with one another are electrically connected to each other through a plurality of the electric connectors 10, a distance between the adjacent lines and/or a distance between the adjacent through-holes may be deviated from the designed distance. A total of a deviation between the adjacent through-holes makes unignorable deviation. Even so, since the connector terminals 20 are held in a non-fixed condition in the spaces R of the first holders 32a, and the connector terminals 20 each includes the deformable buffer portion 23, the first and second press-fit terminals 21a and 21b can be shifted to the corresponding through-holes of the printed circuit boards P1 and P2. Thus, the connector terminals 20 can be all inserted into the printed circuit boards P1 and P2 without difficulty.
As mentioned above, since the first and second press-fit terminals 21a and 21b can be surely inserted into the printed circuit boards P1 and P2, the electric connector 10 enhances the electrical connection between the printed circuit boards P1 and P2, keeping a strength of the connector terminals 20 and enabling the connector terminals 20 to pass a requisite current.
Furthermore, even if the connector terminals 20 are inserted obliquely into the printed circuit boards P1 and P2, the resilient pieces 212 are further resiliently deformed to thereby prevent an excessive stress from acting on the through-holes of the printed circuit boards P1 and P2.
The connector terminal 20 is inserted into an open space formed between the wedges 321b, and is guided into the space R with the claws 321 being resiliently deformed. Thus, the connector terminal 20 can be set into the connector housing 30 after the completion of the connector housing 30. Hence, it is not necessary to set the connector terminal 20 in an injection die when the connector housing 30 is formed by injection molding.
Furthermore, the connector terminal 20 can be held in a fixed or non-fixed condition in the space R in accordance with both a length of the projection 33 and a space between the arms 321a. In addition, it is possible to determine a range in which the connector terminal 20 can swing when the connector terminal 20 is held in a non-fixed condition in the space R. Thus, the connector terminal 20 can be readily set into a fixed condition.
In the first embodiment, the buffer portion 23 is deformed in accordance with a gap between the imaginary longitudinal center lines L of the first and second press-fit terminals 21a and 21b. It should be noted that the first projecting portion 22a in the first embodiment is designed to be formed of a resilient metal plate having a length longer in a length-wise direction of the connector terminal 20 than a width, and hence, the resilient metal plate can be deformed when a gap between the imaginary longitudinal center lines L of the first and second press-fit terminals 21a and 21b is generated in a thickness-wise direction of the connector terminal 20. Hence, the first projecting portion 22a can accomplish the same performance as that of the buffer portion 23. The combination of the buffer portion 23 and the first projecting portion 22a provides enhanced flexibility to the connector terminal 20.
A printed circuit board to be used in an electronic device equipped in a vehicle is subject to expansion and/or contraction due to heat in a temperature range of −20 to 80 degrees centigrade. When an electric connector is soldered to a printed circuit board, a high stress acts on the solder due to expansion and contraction of the printed circuit board. The repeated stresses cause the solder to be cracked, resulting in failure in electrical connection. However, since the first and second press-fit terminals 21a and 21b can be connected to the printed circuit boards P1 and P2 merely by being inserted without being soldered to the printed circuit boards P1 and P2, it is possible to prevent the above-mentioned failure in electrical connection caused by expansion and contraction of the printed circuit board.
An electric connector in accordance with the second embodiment of the present invention is explained hereinbelow with reference to
In an electric connector 20x in accordance with the second embodiment, a second projecting portion 22bx is designed to have the same size as that of a first projection portion 22ax, as illustrated in
The second projecting portion 22bx is designed to be larger than the second projection portion 22b in the first embodiment (see
The present invention provides the connector terminal and the connector housing both of which define the electric connector capable of electrically connecting printed circuit boards to each other by inserting the press-fit terminals formed at opposite ends of the connector terminal, into through-holes formed through the printed circuit boards. Thus, the electric connector can be employed broadly in fields such as an electric/electronic industry and a vehicle industry as a connector used for electric/electronic devices or a connector equipped in a vehicle.
While the present invention has been described in connection with certain preferred embodiments, it is to be understood that the subject matter encompassed by way of the present invention is not to be limited to those specific embodiments. On the contrary, it is intended for the subject matter of the invention to include all alternatives, modifications and equivalents as can be included within the spirit and scope of the following claims.
The entire disclosure of Japanese Patent Application No. 2013-142065 filed on Jul. 5, 2013 including specification, claims, drawings and summary is incorporated herein by reference in its entirety.
Number | Date | Country | Kind |
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2013-142065 | Jul 2013 | JP | national |