1. Field of the Invention
The present invention relates to a socket contact. In particular, it relates to a structure of a socket contact, which elastically connects to an extremely small tabular tab-shaped contact, and is capable of being provided in a print substrate.
2. Related Art
In compact electronic equipment for photographic use of recent years, small-size motors are embedded. Generally, these kinds of small-size motors include a pair of tabular tab-shaped contacts (hereinafter, called “input terminals”). In addition, by supplying electricity to these input terminals, it is possible to drive the small-size motors.
For example, in input terminals of small-size motors such as the above, terminals of the wires thereof are connected by soldering. Moreover, input terminals are inserted into through holes provided on a rigid substrate or a flexible substrate, and the input terminals are joined by soldering to these through holes. In compact electronic equipment for photographic use, many multi-branched foldable flexible substrates are used, and these flexible substrates connect small-size motors and other internal electric and electronic elements.
Automating direct soldering of input terminals of small-size motors to flexible substrates is difficult. The reason is that, if a small-size motor and a flexible substrate are put into a reflow furnace capable of automatic soldering, the small-size motor is heated. In the end, there was no alternative but to rely on soldering by way of skilled manual labor. In addition, this hindered increase of productivity.
In response to these circumstances, small-size motors which are quickly connectable to flexible substrates, are versatile, and allow for cost reduction have been invented (for example, see Japanese Unexamined Patent Application Publication No. H5-115148 (hereinafter referred to as “Patent Publication 1”)).
FIG. 23 is an exploded perspective assembly view of main parts showing an embodiment of a small-size motor according to Patent Publication 1. FIG. 23 of the present application corresponds to FIG. 2 of Patent Publication 1. In FIG. 23, a small-size motor 80 has a case 81 formed in a shape of a bottomed hollow tube. In the case 81, a rotor consisting of an armature and a commutator not shown is internally packaged. An end plate 82 with insulation properties is attached to a rear-end portion of the case 81.
In FIG. 23, ends of a pair of brush arms (not shown) electrically connecting to be slidable to a commutator protrude from an end plate 82 as an input terminal 83. Moreover, a columnar bearing 84 supporting one end of the rotor to be rotatable bulges from the end plate 82. On a circumference of the bearing 84, a toric protrusion 84a is elevated.
In FIG. 23, a connector unit 90 is constructed of a substantially discoid housing 91 and a pair of strip-shaped contacts 92 and 92 fixed to the housing 91 and making a substantially circular arc. In the housing 91, an opening 91a, into which a print substrate (not shown) can be inserted, is formed. Moreover, in the center of the housing 91, a circular hole 91b engaging the bearing 84 is formed. On the left and right flanks of the hole 91b, a pair of rectangular insertion holes 91c and 91c are provided.
In FIG. 23, the contact 92 has, on a side of one end, clamping fragments 92a inserted into the engaging hole (not shown) in communication with the opening 91a formed by way of bending, and has, on a side of another end, contact fragments 92c inserted into the insertion holes 91c formed by way of bending. When the connector unit 90 built up by a pair of contacts 92 and 92 on the housing 91 is attached to the end plate 82, the input terminal 83 and the contact 92 are electrically connected. Moreover, when a print substrate is inserted from the opening 91a, an end of this print substrate is clamped by the pair of clamping fragments 92a and 92a, and therefore this print substrate and this contact 92 are electrically connected.
In this manner, the small-size motor according to Patent Publication 1 is made to be such that, after the connector unit is attached to an end plate of the small-size motor, by only a simple operation of inserting an end edge portion of a print substrate (for example, an FPC) into the connector unit, the print substrate can be attached to the small-size motor with certainty. Moreover, since the print substrate is removable from the connector unit, it is described that modifications to a print substrate with a different circuit specification are extremely simple, and that it is possible to increase maintainability from a user's side as a set maker.
However, compact electronic equipment for photographic use of recent years is packaged to be overcrowded with internal constituent elements. However, as shown in Patent Publication 1, there is no room to provide a small-size motor on a housing-equipped contact, and housing-equipped contacts are becoming difficult to be accepted from the side of users who are set makers. A socket contact connectable to an input terminal of a small-size motor is sought that is capable of providing a bare contact on a print substrate without holding a contact to a housing.
In particular, electronic equipment for photographic use of recent years is being developed to be more compact. Therefore, for example, small-size motors used in compact electronic equipment for photographic use have an outer diameter of the order of 8 mm. In addition, a protruding length of an input terminal is to be 1 mm or less. That is to say, a socket contact made to have a low profile (a low mounting height) connectable to an extremely small tab-shaped contact is sought.
Moreover, in order to reduce contact resistance when connecting the input terminal of the small-size motor to the socket contact, it is preferable to apply gold plating to this input terminal. However, in order to reduce the manufacturing cost of small motors, usually gold plating is not applied to input terminals. The input terminals are either metal plates that are uncoated, or at best a degree of plating by zinc plating or tin plating is applied thereto. Therefore, in order to ensure a certain contact resistance or less, a structure in which contact pressure is increased is sought for the socket contact.
Furthermore, in mounting this socket contact on a print substrate, it is preferable for the socket contact to have a structure that can be easily automatically assembled, thereby increasing productivity. The above can be said to be the objective of the present invention.