JPS6138163Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of a small variable resistor, and its primary purpose is to prevent caulking cracks when a metal shaft is caulked to a circuit board. The second purpose is to prevent sticking during soldering and to increase insulation resistance.

An embodiment of the present invention will be described below with reference to the drawings. First, in the figure, reference numeral 1 denotes a substrate made of an insulating material and having a hole 1a in the center, and a resistor 2 made of cermet is provided around the hole 1a on the surface of the substrate 1. Silver terminals 3 and 3' made of a conductive material are provided at both ends of the resistor 2, and these silver terminals 3 and 3' are connected to the side surface of the substrate 1.
The extension portions 3a, 3a' extend to the back surface of the substrate 1 through b, 1b'. A silver terminal 4 is provided around the hole 1a on the surface of the substrate 1, and is located between the resistor 2 and the hole 1a, and a part thereof is connected to the silver terminal 3. Reference numeral 5 denotes a slider made of a conductive metal material having spring properties. It is attached to the metal shaft 6 so that it can rotate with the metal shaft 6 by bringing it into contact with the linear side surface 6b and caulking the tip of the metal shaft 6 on the back surface of the substrate 1. The diameter of the head 6a having the driver groove 6c of the metal shaft 6 is made larger than the inner diameter l of the arm 5b of the slider 5 to prevent deformation of the slider 5 and to provide a barrier effect. Furthermore, a contact portion 5c is connected to the arm 5b of the slider 5. Reference numeral 8 denotes a resin portion made of an insulating material provided by coating or the like between the silver terminal extension portions 3a and 3a' on the back surface of the substrate 1 and around the hole 1a. Also, 9 and 9' are height adjustment silver terminals provided on the back surface of the substrate symmetrically with the silver terminal extensions 3a and 3a', which should be at the same height. , 9' is also provided with the resin portion 8 by coating or the like. In reality, preliminary solder is provided at the same height on the silver terminal extensions 3a, 3a' and the height adjustment silver terminals 9, 9'.

As mentioned above, the slider 5 co-rotates by rotating the metal shaft 6, and the contact portion 5c at the tip of the arm portion 5b slides over a portion of the resistor 2 and the silver terminal 4, allowing the desired resistance value to be set. can be taken out. This resistance value is taken out by the silver terminal extensions 3a, 3a' on the back surface of the substrate 1.

The present invention is constructed as described above, and since the resin part 8 made of an insulating material is provided around the hole on the back side of the board 1, when the metal shaft 6 is attached to the board 1 by caulking. The resin portion 8 acts as a cushion and can prevent caulking cracks in the substrate 1. Furthermore, when the back side of the board 1 is directly attached to a printed circuit board, etc., the solder distance and insulation resistance between the terminals become a problem due to the small size. This makes it possible to prevent pinching during soldering between terminals and to increase insulation resistance, making it possible to provide high-quality products to users.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the small variable resistor according to the present invention, Fig. 2 is a bottom view of the same, Fig. 3 is an exploded perspective view of the same, and Fig. 4 A, B, and C are the same variable resistors. FIG. 3 is a top view, a front view, and a bottom view of a substrate constituting the device. 1... Board, 1a... Hole, 1b, 1b'... Side surface, 2... Resistor, 3, 3', 4... Silver terminal, 3
a, 3a'...extension part, 5...slider, 6...metal shaft, 8...resin part made of insulating material.

Claims (1)

[Claims for Utility Model Registration] (1) A substrate made of an insulating material having a hole in the center, a resistor provided around the hole on the surface of the substrate, and a resistor connected to both ends of the resistor. two silver terminals having extensions extending to the surface of the substrate, and a portion of the silver terminals provided between the holes on the surface of the substrate and the resistor, and a portion thereof being connected to one of the two silver terminals; A slider that electrically conducts between the silver terminal, the resistor and the silver terminal around the hole, and a slider that is inserted into the hole of the board and caulked with the back surface of the board, and that allows the slider to rotate together. It consists of a metal shaft attached to the
A small variable resistor comprising a resin part made of an insulating material around a hole on the back side of the substrate. (2) The small variable resistor according to claim 1 of the utility model registration claim, in which a resin part made of an insulating material is provided as an extension between the extension parts of the silver terminals extending on the back surface of the board.