Coordinated Control Device For Variable Resistors

Abstract

A device for coordinatedly controlling a plurality of variable resistors so as to achieve a desired combination of a plurality of varied resistances, said device comprising a plate member horizontally movable in any direction and a plurality of wipers which move in accordance with the movement of the horizontally movable plate member in engagement therewith respectively maintaining contact with a resistor.

Description

BACKGROUND OF THE INVENTION

This invention relates to a device for coordinatedly controlling a plurality of variable resistors to create any desired combination of resistances. More particularly, this invention provides a small-sized device with simple compact structure having a single handle for cordinated control of a plurality of variable resistors.

There has been growing demand for an inexpensive simple device for controlling a plurality of variable resistors, which are useful, in the field of consumer electronics, especially for instance, in the case where volumes of a plurality of loud speakers are to be coordinatedly controlled so as to create a desired sound balance as in a stereo or quadraphonic speaker system. Various devices to achieve this purpose are known.

A typical device of the prior art comprises a control stick or lever supported by a ball-and-socket joint which allows the nutation (joystick movement) of the lever, and two U-shaped bridge-like supporters or bridge members having a lengthwise slot which are pivotably supported horizontally at right angles in a gyroscope-like fashion, whereby the lower end of the lever penetrates the slot of the two bridge members so that the two bridge-members swing as the lever nutates. The ends of each bridge member are provided with a wiper which respectively wipes the surface of a resistor element which is placed perpendicular to the rotation or swing axis of each bridge member when the bridge member swings. In some cases, those bridge members directly contact the variable resistors. Thus the desired resistance is determined by the distance between the contact point of the wiper on the resistor element and the lead terminal of either end of the resistor element for four resistors in this case.

However, the construction of the control device of this kind is complicated and therefore is inevitably bulky and costly.

SUMMARY OF THE INVENTION

According to this invention, a simple compact device for coordinatedly controlling a plurality of variable resistors is provided, which comprises a plate member horizontally movable in any direction and a plurality of wipers which move in accordance with the movement of the horizontally movable plate member in engagement therewith respectively maintaining contact with one of a plurality of separate resistor elements, whereby the wipers are moved simultaneously but severally or in a pair so as to achieve a desired combination of resistances.

Various means are possible for horizontally moving the plate member. The plate member can be horizontally moved by picking a small knob or stem provided in the center or any other position on the surface of the plate member as a handle, or moved by nutation or rather precessional movement of a lever (joystick) the middle of which is supported by a ball-and-socket joint provided in the center of the top of the housing of the device and one end of which is connected to the center of the horizontally movable plate member by another ball-and-socket joint.

The movement of the horizontally movable plate member is achieved by a mechanism comprising a supporter which freely slides along one axis and provides a guide for the plate member mounted thereon to allow free movement along another axis perpendicular to the first axis as seen in a customary overhead travelling crane mechanism. When a lever or a joystick is employed, usually the joint of the stick and the horizontally movable plate member has some clearance so that the vertical movement of the plate member does not take place. However, it is also possible to design so as to allow the vertical movement of the plate member when it is moved by means of such a joystick.

The engagement of the horizontally movable plate member and the wipers is achieved by any of various means, for instance, by providing a number of protrusions equal to the number of the wipers in suitable positions in the bottom surface of the horizontally movable plate member, and providing a groove or slot in each wiper which rotates around an axis, each of said protrusions being received in the groove or slot of a wiper.

Various arrangements of resistor elements are possible. In any arrangement, desired resistance is obtained between the wiper contact point and the terminal of either end of the resistor element for each combination of a wiper and a resistor element.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially cut away perspective view of a preferred embodiment of the device of this invention.

FIG. 2 is a perspective bottom view of a horizontally movable plate member of the device shown in FIG. 1.

FIGS. 3, 4 and 5 show the construction of the wiper of the device of FIG. 1.

FIG. 6 is a plan view of the base plate of the device of FIG. 1.

FIG. 7 is a schematic diagram corresponding to FIG. 6 showing the relation between the resistor elements and the wipers of the device of FIG. 1.

FIG. 8 is another embodiment of the horizontally movable plate member as shown in FIG. 2.

FIG. 9 shows another embodiment of the wiper of the device of this invention.

FIG. 10 shows still another embodiment of the wiper of the device of this invention.

FIGS. 11 and 12 show another embodiment of the device of this invention.

FIGS. 13 and 14 show the arrangement of the resistor elements and wipers in another embodiment of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1, member 4 is a case or housing of the device. A lever or joystick 1 is supported in the middle thereof by a ball-and-socket joint 2 provided in the center of the top of the housing 4. The lower end of the lever or joystick is connected to a horizontally movable plate member shown at 5 by another ball-and-socket joint provided in the center of the upper surface of the horizontally movable plate member. The plate 5 is mounted on two sliding rods 7 and 7' along which the plate can freely move to and fro. The two sliding rods 7 and 7' are supported by a pair of sliding guide plates 8 and 8', which freely slide to and fro in a line perpendicular to the two sliding rods along a guide, which is the two walls of the housing facing each other in this case. Depending on the design, there may be overhead clearance in the guide for the sliding guide plates, that is, the housing walls in this case, for allowing slight vertical movement of the plate member when the lever does precessional movement around the fulcrum.

In FIG. 1, wiper finger 19" and 19"', finger carriers 18 and 18"' and resistor elements 22 and 22"' are also shown, which will be explained in detail with reference to FIGS. 3 through 6.

FIG. 2 is a perspective bottom view of the horizontally movable plate member 5. The plate member has two throughholes 6 and 6' which receive the sliding rods 7 and 7', and four protrusions 11, 11', 11" and 11"' are provided in the bottom surface thereof. The socket is shown at 26.

A wiper consists of a resilient finger 19 and a finger carrier 18 which are shown in FIGS. 3, 4 and 5. The finger carrier 18 has a lengthwise groove or slot (in the upper surface thereof in the case of a groove) as shown in FIG. 3, and is provided with at least two protrusions 21a and 21b on the bottom side and has a hole 17 for a rotating axis as shown in FIG. 4. The wiper finger 19 is a spatula-like piece as shown in FIG. 5, and is provided with a hole 20c for the rotating axis and holes 20a and 20b for receiving the protrusions 21a and 21b of the finger carrier 18. The carrier 18 and the finger 19 are united by means of the protrusions 21a, 21b and holes 20a, 20b to form a wiper, whereby the finger carrier is made of a non-conducting material and the finger of an electroconductive resilient metal blade.

In FIG. 6, which is a plan view of the top of the base 9 of the device, four resistor elements shown at 22, 22', 22" and 22"' are arranged in a swastika-like pattern having a common terminal in the center, which is grounded. The end of each resistor element has a lead terminal 16, 16', 16" or 16"'. The four wipers are rotatably and electroconductively supported on axes 10, 10', 10" and 10"' respectively by holes 17 and 20c, so that the finger thereof may wipe the surface of each resistor element. The thus constructed base plate is combined with the above-explained horizontally movable plate member 5 as shown in FIG. 1 so that each of the protrusions thereof 11, 11', 11" and 11"' may be received by the groove or slot 12 of the finger carrier of a corresponding wiper. A desired resistance is obtained between the wiper-resistor element contact point and the terminal for each resistor element.

The four protrusions 11 etc. are positioned in an arrangement such that when the lever stands upright or vertically, it takes an absolutely neutral position, that is, the four wipers are positioned as shown in FIG. 6, wherein the four resistances obtained between the wiper-resistor element contact points and the terminals are the same and a pair of wipers located diametrically opposite are in parallel. When the lever is nutated in one direction, the lower end thereof moves in the opposite direction, and thus the horizontally movable plate member 5 is shifted in that direction. Such shifting or sliding of the horizontally movable plate member causes horizontal displacement of the four wipers which are engaged with the plate member by means of the protrusions 11 etc. provided in the plate member and the groove or slot 12 provided in the finger carrier of the wiper. When the horizontally movable plate member moves horizontally according to the nutating or precessional movement of the control lever, a protrusion 11"' for instance can take any position within a circle shown at 27"' in FIG. 6. When the lever is nutated in a direction parallel with a pair of wipers, for instance, along a line Z - Z' in FIG. 7, the resistances determined by the pair of wipers 18 and 18" are unchanged and the resistances of the remaining two resistor elements are relatively changed. Thus, any desired combination of the four resistances can be achieved by operating the control lever in a precessional or nutating movement with the combination effect as reflected in the sound effect or any other phenomena resulting from the combination being checked.

An alternate means for engagement of the horizontally movable plate member and the wipers is as follows. In this case, four grooves are provided in the bottom of the plate member instead of protrusions as shown in FIG. 8, and a protrusion is provided in the finger carrier instead of a groove or slot as shown in FIG. 9. Alternatively, the protrusion can be provided in the wiper finger per se as shown in FIG. 10. This can be easily effected by caulking or drawing. It is apparent that when these plate member and wiper assemblies or wiper fingers are combined so that the protrusions of the wipers are received in the corresponding grooves, the combination of the horizontally movable plate member and the wipers functions in the same way as the combination explained above.

As mentioned above, the horizontally movable plate member 5 can be moved not only by a joystick but also by any means, for instance, by a small knob secured in the center of the upper surface of the horizontally movable plate member as shown in FIGS. 11 and 12, in which the knob is shown at 1 and a circular opening 2' provided in the top of the housing 4 functions as the guide for the knob.

In another embodiment, resistor elements are arranged as shown in FIGS. 13 and 14. In this embodiment, each resistor element has two proper end terminals instead of one proper terminal and one common terminal shared by several elements as explained hereinbefore. And in this case, a separate intermediate terminal 28 may be provided in the middle of each resistor element. Thus a number of varied resistances can be obtained in desired combinations. The intermediate terminals can be arranged as shown in FIG. 14. In this embodiment, the intermediate terminals are the rotation axes of the wipers, which are connected to the respective resistor elements by bridging circuits 28 etc. The terminals, that is, the rotation axes of the wipers, may be either separate units or one integrated piece. In the latter case, the common terminal may be used for grounding as in the first embodiment.

Claims

What I claim is:

1. A device for coordinatedly controlling a plurality of variable resistors comprising a plate member horizontally movable in any direction supported by a mechanism comprising a supporter which freely slides along one axis and provides a guide for the horizontally movable plate member mounted thereon to allow free movement along another axis at right angles to the first axis and a plurality of wipers which move in accordance with the movement of the horizontally movable plate member in engagement therewith respectively maintaining contact with a separate resistor element, whereby each wiper can be made to rotate around one axis while remaining in contact with a resistor element at the other end thereof and either the horizontally movable plate member or each of the wipers has a protrusion on the side facing the other, and the other of the two has a groove or slot to receive the protrusion so that the wiper is rotated around the axis when the horizontally movable plate member is moved.

2. A device as set forth in claim 1 wherein the mechanism supporting the horizontally movable plate member comprises a pair of parallel sliding rods rigidly supported by a pair of sliding guide plates perpendicular to said pair of the sliding rods, said rods functioning as a guide for the horizontally movable plate member and said guide plates slide along a pair of facing walls of a housing of the device.

3. A device as set forth in claim 1 wherein the horizontally movable member has a knob on the upper side thereof and the top of the housing has a circular opening which functions as a guide for the knob when the knob is moved.

4. A device as set forth in claim 1 wherein the horizontally movable plate member has the protrusions and each wiper has a groove or slot.

5. A device as set forth in claim 1, wherein the horizontally movable plate member is connected to an end of a lever by a ball-and-socket joint at the center thereof, and the lever is supported in the middle thereof by another ball-and-socket joint provided at the center of the top of the housing of the device so that the horizontally movable member is moved when the lever does a nutating or precessional, that is, joystick movement.

6. A device as set forth in claim 5, wherein each wiper comprises a resilient finger and a finger carrier.

7. A device as set forth in claim 5, wherein the resistor elements are arranged in a arcuate swastika-like pattern on a square base plate and the four wipers are provided on the base plate each with the rotation axis thereof at the center of each edge of the base plate.

8. A device as set forth in claim 5, wherein the resistor elements are arranged in a circumferential pattern on a base plate and the four wipers are provided on the base plate each with the rotation axis thereof at the central portion of the plate.

9. A device as set forth in claim 8, wherein each resistor element has an intermediate terminal in the middle thereof so that different resistances can be obtained with one element.

10. A device as set forth in claim 9, wherein the intermediate terminal is the axis of a corresponding wiper which is connected to a suitable position in a corresponding resistor element by means of a bridging circuit.

11. A device as set forth in claim 1, wherein each wiper comprises a resilient finger and a finger carrier.

12. A device as set forth in claim 1, wherein the resistor elements are arranged in an arcuate swastika-like pattern on a square base plate and the four wipers are provided on the base plate each with the rotation axis at the center of each edge of the base plate.

13. A device as set forth in claim 1, wherein the resistor elements are arranged in a circumferential pattern on a base plate and the four wipers are provided on the base plate each with the rotation axis at the central part of the plate.

14. A device as set forth in claim 13, wherein each resistor element has an intermediate terminal in the middle thereof so that different resistances can be obtained with one element.

15. A device as set forth in claim 14, wherein the intermediate terminal is the axis connected to a suitable position in a corresponding resistor element by means of a bridging circuit.