GB2183927A

GB2183927A - Variable capacitor and variable resistor combination

Info

Publication number: GB2183927A
Application number: GB08628977A
Authority: GB
Inventors: Kazuo Sato
Original assignee: Alps Electric Co Ltd
Current assignee: Alps Alpine Co Ltd
Priority date: 1985-12-05
Filing date: 1986-12-03
Publication date: 1987-06-10
Also published as: JPH043494Y2; JPS6296829U; GB8628977D0; KR890009403Y1; GB2183927B; KR870011232U

Abstract

A variable capacitor and a variable resistor combination includes a resistor element (4) having a resistive layer (4a) engaged by a slider (5) and a capacitor (1) mounted on a common rotary shaft (1b). The slider (5) is secured to a slider receptor (6) on a surface thereof which faces variable capacitor (1) so that when the slider receptor (6) is rotatably attached to the rotor shaft (1b), the slider receptor (6) is located in the clearance between the slider (5) and sliding surface of the resistor element (4a) namely within the slider segments (5a, 5b) of the slider operating height of slider (5). The (5) extend through a cut-away part of the slider receptor (6) into engagement with the resistive layer (4a). <IMAGE>

Description

SPECIFICATION Variable capacitor and variable resistor combination The present invention relates to a variable capacitor and a variable resistor combination in which the capacitance of variable capacitor and resistance of variable resistor are varied with a single shaft.

It is an object of the present invention to provide an improved variable capacitor and variable resistor combination.

According to the present invention there is provided a variable capacitor comprising a variable resistor having a structure such that a slider receptor is rotatably attached to the rotor shaft of a variable capacitor and the capacitance and the resistance can be changed by.

rotation of such rotor shaft, wherein a slider is attached to the slider receptor on side thereof facing the variable capacitor so that the slider receptor rotatably attached to said rotor shaft is located between the slider and the resistor element sliding surface, namely within the operation height of slider and a slider member comes to contact with the sliding surface of the resistor element through a cut-away part provided at a part of the slider receptor.

The present invention also provides that the slider of the slider receptor surface is on a side thereof facing the variable capacitor so that the slider receptor which is rotatably attached to the rotor shaft is located between the slider and the element sliding surface, namely within the operating height of the slider and realises that plate thickness of slider receptor can be accommodated within the operating height of slider by placing the slider segments to contact with the sliding surface of element through a cut-away part provided at a part of the slider receptor, and is thereby characterised in that the height of combination can be reduced.

A variable capacitor and a variable resistor combination embodying the invention will now be described by way of example with reference to the accompanying diagrammatic drawings in which: Figure 1 is an exploded perspective view of the combination; Figure 2 is a fragmentary section of the combination of Fig. 1; Figure 3 is a side elevation of the slider of the combination; Figure 4 is an exploded perspective view of a previously proposed combination; Figure 5 is a fragmentary section of the combination of Fig. 4; and Figure 6 is a side elevation of the slider of the combination of Fig. 4.

Figs. 4 to 6 show a previously proposed variable capacitor and variable resistor combination.

As shown the combination comprises a small size variable capacitor 1 using a dielectric film material and a variable resistor 2. The variable resistor 2 is composed of a substrate 3, an element 4 providing a resistive layer 4a and a collecting layer 4b, a slider 5 providing two sliding members 5a, 5b which are respectively in slidable contact with the resistive layer 4a and the collector 4b, and a slider receptor 6 which holds the slider 5.

The variable capacitor 1 includes a substrate or base plate 1a, a rotor shaft 1b for rotating a rotor plate within the variable capacitor 1, and a pole for supporting stator plates. A plurality of terminals 1 c are electrically connected to each stator plate.

The substrate 3 which accommodates and holds the element 4 of variable resistor (see Fig. 4) is provided with a fitting part 3a with which the element 4 engages, a shaft inserting hole 3b into which the rotor shaft 1 b of variable capacitor 1 can be inserted, and a terminal inserting hole 3c into which each terminal 1c can be inserted.

The shaft inserting hole 3b and the terminal inserting hole 3c are respectively provided at the positions corresponding to the rotor shaft 1 b and terminal 1 c of the variable capacitor 1.

The shaft inserting hole 3b is provided at the centre of substrate 3. The four terminal inserting holes 3c are provided at the four corners of the substrate 3. Each terminal inserting hole 3c is sized so as to allow a corresponding terminal 1 c to be press fitted therein and thereafter held therein by frictional force.

The resistive layer 4a of the element 4 extends around the collector layer 4b. The element 4 has three terminals. Within the collector layer 4b is the insertion hole 4c into which the rotor shaft 1 b can be inserted with some clearance. The hole 4c is coaxial with the rotor shaft inserting hole 3b of the substrate 3.

The slider receptor 6 which holds the slider 5 on the under surface thereof has a shaft inserting hole 6a into which the rotor shaft 1 b can be press fitted. The shaft inserting hole 6a is elongate and is almost the same shape as the rotor shaft 1 b so that the receptor rotates in unison with the rotor shaft 1b.

The slider 5 is provided with a hole into which a projection 6b can be inserted. The slider 5 can be fixed when the projection 6b of slider receptor 6 is inserted into said hole and rotates in unison with the slider receptor 6. Moreover, said slider receptor 6 is fitted to the slider receptor 6 when the variable resistor 2 is mounted on the variable capacitor 1.

The rotor shaft 1 b of variable capacitor 1 engages the slider receptor 6 so that the slider segments 5a, 5b of slider 5 are biassed into contact with the sliding surface of element 4.

The clearance between the sliding surface of the element 4 and the slider 5 fixing surface of slider receptor 6, namely the under surface thereof is small.

The clearance provided between the slider receptor 6 and the element 4, namely height of slider 5 requires the height of the combination to be increased accordingly and it is difficult to reduce this height. Any height reduction usually requires the use of a new lower slider 5 and an alteration in the setting of the spring pressure of the slider 5 for the sliding surface of element 4. But, in order to lower the height of slider 5 and to obtain the same spring pressure, a slider material having a higher spring pressure must be selected and even when the same spring pressure is obtained, the fluctuation of spring pressure becomes larger.

In the combination shown in Figs. 1 to 3 parts similar to those shown in Figs. 4 to 6 are similarly referenced.

As shown in Figs. 1 to 3 the combination includes a small size capacitor 1 having a film dielectric material and a variable resistor 2.

The variable resistor 2 comprises a substrate 3, a resistor element 4 providing a resistive layer 4a and collector layer 4b, a slider 5 having two slider segments 5a, 5b which respectively make contact with the resistive layer 4a and the collector layer 4b and a slider receptor 6 which holds the slider 5.

The variable capacitor 1 includes a base plate or a substrate 1a, a rotor shaft 1b for rotating the rotor plate within the variable capacitor, and a pole for supporting the stator plates. A plurality of terminals 1c are electrically coupled to each stator plate.

The substrate 3 which accommodates and holds the element 4 of variable resistor 2 shown in Fig. 1 is provided with the fitting part 3a with which the element 4 engages, a shaft inserting hole 3b into which the rotor shaft 1b of variable capacitor 1 can be inserted with some clearance and the terminal insertion holes 3c into which the terminals Ic can be inserted.

The shaft inserting hole 3b and terminal insertion holes 3c are provided at the positions respectively corresponding to the rotor shaft ib and the terminals Ic of variable capacitor 1. The shaft inserting hole 3b is provided in the centre of substrate 3 and the terminal inserting holes 3c are provided at the four corners of the substrate 3. The terminal inserting holes 3c are sized to allow corresponding terminals 1 c to be press fitted therein and thereafter held therein by friction force.

The element 4 has the outer resistive layer 4a, an inner collector 4b and three terminals.

Within the confines of the collector 4b, is insertion hole 4c into which the rotor shaft 1b can be inserted with some clearance. The insertion hole is coaxial with the rotor shaft inserting hole 3b. A shaft inserting hole 6a into which said rotor shaft 1 b can be inserted is formed in the centre of slider receptor 6. The shaft inserting hole 6a is elongate having the same shape as said rotor shaft 1 b so that the receptor 6 rotates in unison with the rotor shaft 1 b. The slider 5 has holes which accommodate projections 6b from the slider receptor 6. When the projections 6b of the slider receptor 6 engage the holes, the slider is coupled to and rotates in unison with the slider receptor 6. In addition, projections 6b are provided on the slider receptor surface facing the variable capacitor 1.The slider receptor 6 allows the insertion of the rotor shaft 1 b of variable capacitor and is thereby positioned so that when the variable resistor 2 is mounted in the variable capacitor 1 the slider segments 5a, 5b carried by the slider receptor 6 are made to contact the sliding surface of element 4 with a constant spring pressure, leaving only a small clearance between the element sliding surface and the lower surface of the slider receptor 6. Moreover, the slider 5 is mounted on the slider receptor surface 6c which faces the variable capacitor so that the slider receptor is located in the clearance between the slider 5 and element sliding surface, namely within the operating height of slider.

The slider members 5a, 5b are in contact with the sliding surface of element through a cutaway part 6d of the slider receptor 6.

As will be appreciated, the slider receptor can be accommodated within the operating height of the slider by mounting the slider on the side of the slider receptor opposite to that facing the resistive layer.

Claims

1. A variable capacitor and a variable resistor combination comprising a resistor element having a resistive layer and a collector, a slider having slider members in sliding contact with the resistive layer and the collector layer to electrically interconnect the resistive layer and the collector layer and a slider receptor, the slider being secured to the slider receptor on a side thereof remote from the resistor element.

2. A combination according to Claim 1, wherein said variable capacitor and said slider receptor are secured to a common rotor shaft so that rotation of the shaft produces a simultaneous change in capacitance and resistance.

3. A combination according to Claim 1, wherein said slider is attached to the slider receptor on a side thereof which faces the variable capacitor so that when the slider receptor is attached to said rotor shaft it is located between the slider and resistive and collector layers.

4. A combination according to any preceding claim, wherein said slider members which contact the sliding surfaces of the resistor element extend through an opening in the slider receptor.

5. A variable capacitor and variable resistor combination substantially as hereinbefore described with reference to Figs. 1 to 3 of the accompanying drawings.