A male terminal fitting and a production method therefore

The present invention relates to a male terminal fitting and to a production method for such a male terminal fitting.

Male terminal fittings formed by applying bending and the like to a plate-shaped metallic terminal material stamped out into a specified shape and having a specified thickness are widely known. In the male terminal fitting of this type, the leading end of the terminal material is folded back to form a thick tab (see Japanese Unexamined Patent Publication No. 11-224701). By forming the tab by folding back the terminal material, the thickness of the tab can be twice as large as that of the terminal material.

JP 09 223532 relates to a male terminal having a connection portion for connection to a female terminal which connection portion is formed by bending an electrically conductive sheet material, wherein the connection portion includes a bottom base portion and a contact portion, and the connection portion is bent and folded, with the contact portion superposed on the bottom base portion.

In a connection construction for connecting a male and a female terminal fittings, the thickness of the tab of the male terminal fitting is sometimes strictly determined by the state of the female terminal fitting. In such a case, a terminal material having half the thickness of that of the tab has been selected as the material of the male terminal fitting.

On the other hand, the male terminal fitting and a wire are connected by a method for crimping a barrel portion formed at the male terminal fitting into connection with the wire using an applicator. There is a limit in a range of the thickness of the terminal materials which can be coped with by one kind of applicator. If an attempt is made to reduce production costs by reducing the number of kinds of applicators in such circumstances, the range of selection is obliged to be narrowed in selecting the thickness of the terminal material.

However, a reduced variety of thicknesses of the terminal material leads to a reduced variety of thicknesses of the tab. As a result, the thickness of the tab required by the state of the female terminal fitting may not be coped with.

It is an object of the present invention to provide a male terminal fitting having an improved tab.

Accordingly, there is provided a tab having a desired thickness without being influenced by the thickness of a terminal material.

This object is solved according to the present invention by a male terminal fitting according to claim 1 and by a production method according to claim 8. Preferred embodiments of the invention are subject of the dependent claims.

According to the invention, there is provided a male terminal fitting made of a plate-shaped metallic terminal material and having a tab formed by substantially folding back or bending the terminal material, wherein the tab comprises a base portion, at least one substantially U-shaped turning portion, at least one overlapping portion which is connected to the base portion via the turning portion and substantially faces the base portion, and at least one raising portion extending from an end of the overlapping portion and held substantially in contact with the base portion.

The thickness of the tab can be set at a desired value regardless of the thickness of the terminal material by changing a curvature of the turning portion and a projecting distance of the raising portion.

Furthermore, a contact area of the base portion with the raising portion(s) is/are recessed and/or slanted to form a receiving portion which preferably is stepped from and substantially parallel to the remaining area of the base portion.

There is a restriction in reducing the projecting distance of the raising portion in view of bending processing. However, since the recessed receiving portion is formed in the contact area of the base portion with the raising portion, the projecting distance of the raising portion can be increased.

According to a preferred embodiment of the invention, the overlapping portion faces the base portion substantially in parallel.

Preferably, the raising portion extends from the overlapping portion substantially at right angles.

According to a further preferred embodiment, there is provided a male terminal fitting made of a plate-shaped metallic terminal material and having a tab formed by folding back the terminal material, wherein the tab comprises a flat base portion, a substantially U-shaped turning portion, a flat overlapping portion which is connected to the base portion via the turning portion and faces the base portion substantially in parallel, and a raising portion extending from an end of the overlapping portion substantially at right angles and held in contact with the base portion.

Preferably, a contact area of the base portion with the raising portion(s) is/are recessed to form a receiving portion which preferably is stepped from and substantially parallel to the remaining area of the base portion.

There is a restriction in reducing the projecting distance of the raising portion in view of bending processing. However, since the recessed receiving portion is formed in the contact area of the base portion with the raising portion, the projecting distance of the raising portion can be increased.

Further preferably, a contact area of the base portion with the raising portion is formed into a receiving surface preferably slanted with respect to the remaining area of the base portion, and a projecting end of the raising portion is formed into a contact surface slanted substantially in parallel to the receiving surface or complementary to the corresponding receiving surface.

A variation of the projecting distance of the raising portion due to a tolerance can be taken up by bringing the contact surface into slidable contact with the receiving surface. Therefore, the thickness of the tab can be adjusted with high accuracy.

Still further preferably, the base plate comprises a further or mating raising portion projecting therefrom which substantially comes into contact with the raising portion formed on the overlapping portion.

Most preferably, at least one space is defined between the base portion, the turning portion, the overlapping portion, and the raising portion.

According to the invention, there is further provided a method for producing a male terminal fitting, in particular according to the invention or an embodiment thereof, comprising the following steps: <ul id="ul0001" list-style="none" compact="compact"><li>providing a substantially plate-shaped metallic terminal material and</li><li>forming a tab by substantially folding back the terminal material, wherein in the folding step the following steps are performed: <ul id="ul0002" list-style="none" compact="compact"><li>bending the terminal material to form    a base portion,    at least one substantially U-shaped turning portion,    at least one overlapping portion, which is connected to the base portion</li><li>via the turning portion and substantially faces the base portion, and    at least one raising portion extending from an end of the overlapping portion</li></ul></li></ul> wherein the raising portion is formed such that it is held substantially in contact with the base portion.

The method further comprises a step of recessing and/or slanting the base portion to form a receiving portion for the raising portion.

Preferably, the raising portion is formed with a shape substantially complementary to the shape of the receiving portion.

These and other objects, features and advantages of the present invention will become apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments. <ul id="ul0003" list-style="none" compact="compact"><li>FIG. 1 is a perspective view of a male terminal fitting which is not covered by the present set of claims,</li><li>FIG. 2 is a lateral section of a tab of the male terminal fitting,</li><li>FIG. 3 is a lateral section of a tab of a first preferred embodiment,</li><li>FIG. 4 is a lateral section of a tab of a second preferred embodiment,</li><li>FIG. 5 is a lateral section of a tab of a third preferred embodiment, and</li><li>FIG. 6 is a lateral section of a tab of a fourth preferred embodiment.</li></ul>

[First Embodiment]

Hereinafter, a male terminal fitting which is not by the present set of claims is described with reference to FIGS. 1 and 2.

A male terminal fitting is formed by applying bending and the like to a conductive plate-shaped metallic terminal material stamped out into a specified shape by a press. An open barrel portion 11 to be crimped or bent substantially into connection with an unillustrated wire is provided at the rear end of the male terminal fitting, and a tab 10A for the connection with an unillustrated female terminal fitting is provided at the front end thereof.

The tab 10A is formed by folding or bending back the terminal material along a fold extending in forward and backward directions and, accordingly, is narrow or elongated in forward and backward directions as a whole. The thickness (dimension in a direction in which portions of the terminal material are placed one over the other by folding) of the tab 10A is strictly specified by the state of the female terminal fitting. The required thickness of the tab 10A is 0.65 mm, and a dimensional tolerance is ±0.02 to 0.025 mm. On the other hand, the thickness of the terminal material is 0.25 mm. Accordingly, if the terminal material having a thickness of 0.25 mm is folded to put the upper and lower portions thereof together, the thickness of the tab 10A is thinner than the required thickness by 0.15 mm. In order to solve this problem, the tab 10A takes a shape as described below.

Specifically, as shown in FIG. 2 (lateral section obtained by cutting the tab 10A along a plane normal to the longitudinal direction of the tab 10A), the tab 10A is comprised of a base portion 12 preferably in the form of a substantially flat plate, a substantially U-shaped turning portion 13, an overlapping portion 14 preferably in the form of a substantially flat plate which is connected to the left end of the base portion 12 via the turning portion 13 and faces the upper surface of the base portion 12 substantially in parallel with a space S defined therebetween, and an elevated or lift-up portion or raising portion 15 extending downward substantially preferably at right angles from the right end (the end opposite from the turning portion 13 with respect to widthwise direction) of the overlapping portion 14 and held in contact with the upper surface of the base portion 12. In forming the tab 10A, the raising portion 15 is first formed by bending the substantially flat terminal material and then, bending is applied to fold the overlapping portion 14 back with respect to the base portion 12. It is to be understood, that the base portion 12, the turning portion 13, the overlapping portion 14 and/or the raising portion 15 may be of a shape different from a flat shape, such as with embosses, recesses, grooves, projections, etc. Accordingly, the elevated or lift-up or raising portion 15 provides the overlapping portion 14 at a distance or lifts it up from the base portion 12 so as to form the space S between the base portion 12 and the overlapping portion 14.

In the tab 10A thus formed, thickness tb of the base portion 12 and the overlapping portion 14 is 0.25 mm which is the thickness of the terminal material, and a projecting distance tc of the raising portion 15 from the lower surface of the overlapping portion 14 is 0.15 mm. Accordingly, thickness ta of the tab 10A as a whole is a total of the thickness tb (0.25 mm) of the base portion 12, the thickness tb (0.25 mm) of the overlapping portion 14, and the projecting distance tc (0.15 mm) of the raising portion 15, i.e. the required thickness of 0.65 mm.

As described above, the thickness ta of the tab 10A can be set at a desired value regardless of the thickness tb of the terminal material by changing a curvature of the turning portion 13 and the projecting distance tc of the raising portion 15.

[First Embodiment]

Next, a first preferred embodiment of the present invention is described with reference to FIG. 3.

In a contact area of the base portion 12 with the raising portion 15, a recessed receiving portion 16 which is stepped from and substantially parallel to the remaining area of the upper surface of the base portion 12 is formed in a tab 10B of the first embodiment. The receiving portion 16 is formed preferably by pressing a specified area by a press before bending is applied.

It should be noted that, since the construction other than the receiving portion 16 is same or similar as in the above described male terminal fitting, no description is given on the structure, action and effects thereof by identifying it by the same reference numerals.

There is a restriction in reducing the projecting distance of the raising portion 15 in view of bending processing. However, since the recessed receiving portion 16 is formed in the contact area of the base portion 12 with the raising portion 15 in the first embodiment, a projecting distance td of the raising portion 15 from the overlapping portion 14 can be increased. Therefore, the raising portion 15 can be easily formed.

[Second Embodiment]

Next, a second preferred embodiment of the present invention is described with reference to FIG. 4.

In a tab 10C of the second embodiment, a slanted receiving surface 17 which is inclined with respect to the remaining area of the upper surface of the base portion 12 is formed in the contact area of the base portion 12 with the raising portion 15, and a projecting end surface of the raised portion 15 is formed into a contact surface 18 which is inclined substantially parallel to the receiving surface 17 in the bent or final condition. The receiving surface 17 and the contact surface 18 are formed preferably by pressing by a press before bending is applied.

It should be noted that, since the second embodiment is same or similar as the prior art male terminal fitting except the receiving surface and the contact surface, no description is given on the structure, action and effects of the same construction by identifying it by the same reference numerals.

According to the second embodiment, a variation of the projecting distance of the raising portion 15 due to a tolerance can be taken up by bringing the contact surface 18 into slidable contact with the receiving surface 17. Therefore, the thickness of the tab 10C can be adjusted with high accuracy.

[Third Embodiment]

Next, a third preferred embodiment of the present invention is described with reference to FIG. 5.

A tab 10D of the third embodiment differs from the tab 10C of the second embodiment in that a receiving surface 19 is stepped down (lowered) from the upper surface of the base portion 12. Accordingly, the projecting distance of the raising portion 15 from the overlapping portion 14 can be increased. Therefore, the raising portion 15 can be easily formed.

[Fourth Embodiment]

Next, a preferred fourth embodiment of the present invention is described with reference to FIG. 6.

Unlike the tab 10B of the first embodiment in which the overlapping portion 14 extends only from one side end of the base portion 12, a pair of left and right overlapping portions 14L, 14R are folded back from the opposite side ends of the base portion 12 via turning portions 13L, 13R, and raising portions 15L, 15R are formed at the ends of these two overlapping portions 14L, 14R in a tab 10E of the fourth embodiment. In a contact area of the base portion 12 with the raising portions 15L, 15R, i.e. in a widthwise middle portion of the upper surface of the base portion 12, a recessed receiving portion 20 is preferably formed which is stepped from and substantially parallel to the remaining area of the upper surface of the base portion 12. Since the raising portions 15L, 15R are arranged in the widthwise center portion of the tab 10E in the fourth embodiment, two separate spaces S are laterally provided between the base portion 12 and the overlapping portions 14L, 14R, thereby enhancing the rigidity of the tab 10E against a squeezing force acting in the thickness direction of the tab 10E. It should be noted that no description is given on the other action and effects since they are same as in the first embodiment.

<Other Embodiments>

The present invention is not limited to the above described and illustrated embodiments. For example, the following embodiments are also embraced by the technical scope of the present invention as defined in the claims. Beside the following embodiments, various changes can be made without departing the sprit of the present invention as defined in the claims. <ul id="ul0004" list-style="none" compact="compact"><li>(1) Although one overlapping portion is folded back at only one side end of the base portion in the foregoing embodiments 1 to 3, two overlapping portions may be folded back at the opposite side ends of the base portion according to the present invention.</li><li>(2) Although the raising portion projects only from the overlapping portion in the respective foregoing embodiments, two raising portions may project from both the overlapping portion and the base portion toward each other according to the present invention. In such a case, the projecting end surfaces of the both raising portions may substantially abut against each other or the raising portion projecting from the overlapping portion may be in contact with the base portion and the one projecting from the base portion may be in contact with the overlapping portion.</li><li>(3) Although the slanted receiving surface is formed by thinning the base portion toward its side end edge opposite from the turning portion to form a wedge-shaped portion in the third and fourth embodiments, the inclination of the receiving surface may be reversed according to the present invention. In such a case, an area of the receiving surface may be larger than that of the contact surface.</li><li>(4) Although the male terminal fitting connected with the wire by crimping is described in the foregoing embodiments, the present invention is also applicable to male terminal fittings connected with a wire by insulation displacement or by both crimping and insulation displacement.</li></ul>

LIST OF REFERENCE NUMERALS

<dl id="dl0001" compact="compact"><dt>10A</dt><dd>tab</dd><dt>12</dt><dd>base portion</dd><dt>13</dt><dd>turning portion</dd><dt>14</dt><dd>overlapping portion</dd><dt>15</dt><dd>raising portion</dd><dt>10B, 10C, 10D, 10E</dt><dd>tab</dd><dt>13L, 13R</dt><dd>turning portion</dd><dt>14L, 14R</dt><dd>overlapping portion</dd><dt>15L, 15R</dt><dd>raising portion</dd><dt>16, 20</dt><dd>receiving portion</dd><dt>17</dt><dd>receiving surface</dd><dt>18</dt><dd>contact surface</dd></dl>