Rotary Switch Having a Stator With a Conductive Matrix

The present invention relates to rotary switches of the type having a complex electrical matrix positioned in a non-conductive support member as the stator and a rotor having contacts disposed adjacent to the matrix.

One purpose of the invention is a switch of the type described in which the stator has a complex conductive matrix positioned within a non-conductive support member with the matrix and support member having respective and cooperating openings and projections for positioning the matrix relative to the support member.

Another purpose is a structure of the type described in which the rotor encloses all of the switching contact areas.

Another purpose is a structure of the type described in which the rotor outer cylindrical wall carries integral detents.

Another purpose is a structure of the type described having contacts with bifurcated arms.

Another purpose is a rotary switch of the type described in which a rotor has a series of contact pockets, the pockets being positioned variable distances from the rotor axis to provide contact tracking along different radii.

Another purpose is a rotary switch of the type described in which the rotor and stator have cooperating hubs providing bearing surfaces.

Another purpose is a rotor of the type described formed of a resilient material holding the rotor shaft in a press fit, thus eliminating backlash between the shaft and rotor.

Another purpose is a stator of the type described in which the support member is formed of a thermoplastic material so that the matrix may be attached to the support member by heat or sonic welding.

Another purpose is a rotary switch of the type described in which switch sections may be stacked, one upon the other.

Another purpose is a rotary switch of the type described having an integral stop on the stator and a washer on the switch shaft which is formed and adapted to cooperate with the stop.

Another purpose is a rotary switch having a stator and rotor of the type described in which each stator section has integral spacing posts.

Another purpose is a stator for use in a switch construction providing for stacking of several such sections and with recesses in the stator to accomodate spacers between switch sections.

Another purpose is a rotary switch in which the stator mounts a conductive matrix formed of criss-crossing integral stator sections which may be severed to provide specified circuit configurations.

Another purpose is a structure of the type described in which the stator matrix sections may be severed by mechanical or chemical means.

Other purposes will appear in the ensuing specification, drawings and claims.

The invention is illustrated diagrammatically in the following drawings wherein:

FIG. 1 is a front view of a switch of the type described,

FIG. 2 is a side view of the switch with switch sections stacked together,

FIG. 3 is a back view of the switch,

FIG. 4 is a plan view of the stator with the matrix removed,

FIG. 5 is a bottom view of the stator of FIG. 4, with portions broken away,

FIG. 6 is a section along plane 6--6 of FIG. 4,

FIG. 7 is a plan view of the conductive matrix,

FIG. 8 is a section along plane 7--7 of FIG. 2, with parts broken away,

FIG. 9 is a section along plane 9--9 of FIG. 8,

FIG. 10 is a plan view of the rotor, and

FIG. 11 is a perspective of a stacking spacer.

The switch basically includes a rotor, a stator, and a shaft. Looking particularly at FIG. 9, the shaft is indicated at 10, the rotor at 12 and the stator is indicated generally at 14. Stator 14 is made up of two generally identical stator sections 16 which are shown in detail in FIGS. 4, 5, 6 and 7. The rotor is shown in detail in FIG. 10.

Looking first at the stator, each section 16 includes a non-conductive support member or housing portion 18 which may conveniently be made of a suitable plastic material. Support member 18 has a base 20 and a series of spaced, variably positioned, upwardly-extending projections 22, shown in plan in FIG. 4, which projections are used to locate a conductive matrix 24 shown in detail in FIG. 7. FIG. 8 shows conductive matrix 24 positioned upon base 20 with projections 22 properly locating the matrix. In this connection, after assembly, since the stator may be formed of a thermoplastic material, the matrix 24 may be permanently affixed to base 20 by heat or sonic welding. Base 20 may further have four upstanding hollow posts 26 which are generally located adjacent corners of base 20 which are used to properly space the two stator sections, one from another. Note particularly FIG. 2, which shows a pair of switches mounted on a single shaft, but which clearly shows projections 26 spacing stator sections 16 in proper relationship with each other. Base 20 further has, at each corner, detent spring projections 28 and 30. Note in the plan view of FIG. 4 that projection 28 is solid, whereas, projection 30 has a groove 32. A detent spring 34, shown in FIG. 8, has a pair of laterally extending arms 36, with a flange 38 at the end of each arm. Flanges 38 will extend through grooves 32 with the end of each flange bearing against a projection 28. Thus, projections 28 and 30 are effective to hold the detent springs within the switch and disposed relative to the detent projections on the rotor.

Base 20 has a generally central opening 40 surrounded by a cylindrical bearing member 42 which cooperates with a hub on the rotor as described hereinafter. Looking at the outside surface of base 20, there is a somewhat U-shaped indentation or recess 44 in alignment with each post 26. Such recesses are formed and adapted to receive generally U-shaped spacer members 46, illustrated in FIG. 11, for the purpose of spacing switches, as particularly illustrated in FIG. 2. The spacers may be of varying width, depending upon the desired relative position of the stacked switches. Also formed in the outside surface of base 20 is an outwardly projecting stop 48, on one side of shaft 10, and a corresponding or mating recess 50 formed on the opposite side of the shaft. Thus, there is provision for the stacked switch sections to be in contact with each other, eliminating the U-shaped spacers 46. In such an arrangement, stops 48 will fit within projections 50.

Conductive matrix 24 may have a series of criss-crossing individual conductors 52, as particularly illustrated in FIG. 7. There are a plurality of outwardly-extending terminals 54 along one side and a similar series of terminals 56 along the opposite side. The terminals 54 and 56 may be identical or they may be different, as shown in FIG. 7. The terminals may all extend in a direction parallel with the matrix, or one set of terminals may extend at 90.degree. to the matrix, depending upon how the switches will be used relative to a printed circuit board or other supportive member. The matrix includes a central ring 58 which is connected to each individual switching area 60. The ring may be severed or removed during assembly, or it may remain in certain specialized switching applications. Each switching section 60 is connected to an outer ring 62 which in turn is connected to the criss cross conductive members 52. As can be seen from FIG. 8, there is the possibility of a widely varying number of connections from individual switch sections 60 to terminals 54 and 56. In most applications the matrix will be formed as shown in the drawings and certain of the conductive members 52 will be mechanically or chemically severed, depending upon the precise switch pattern desired.

Rotor 12 includes a double D opening 64 which is formed by outwardly-extending hubs 66 which cooperate with bearing ring 42 on the stator sections to insure smooth and accurate rotation of the rotor relative to the stator. Rotor 12 has an outer circumferential wall 68 with a series of generally equally spaced detent projections 70 which cooperate with detent spring 34 to perform a conventional detent or indexing function. A series of spaced contact pockets 72 are formed in rotor 12. As particularly shown in FIG. 10, the pockets are circumferentially generally uniformly spaced, but may have varying radial spacing relative to the center of the rotor and outer wall 68. Note specifically pockets 74, 76 and 78, each of which are spaced different distances from the axis of rotor 12. Thus, the contacts that are positioned in the pockets may be arranged to wipe different portions of switching areas 60, thus providing more effective use, i.e. longer life for given plating thickness, of precious metal plating. Positioned within each of pockets 72 is a contact 82 which has a generally central body portion 84, as particularly shown in FIG. 9, and outwardly-extending bifurcated arms 86. The arms 86 having contact ends 88 are disposed in direct contact with switching matrix 24. As shown particularly in FIG. 9, arms 86 are of equal length, although it may be otherwise.

A bow-shaped washer 90 is positioned within a groove 92 in shaft 10 for holding the shaft to the switch structure. At the opposite end of the switch a stop washer 93 has arms 94 generally formed to extend away from the outer surface of the stator. However, one such arm 95 is bent in the opposite direction to contact and cooperate with stop 48 in a conventional manner. Although only one such stop arm 95 is shown herein, there may be two or more, depending upon the degree to which rotation of rotor 12 is to be permitted.

Of particular advantage in the switch described is the fact that the matrix 24 may be formed to a prescribed set pattern permitting subsequent severing, either mechanically or chemically, of certain conductive sections to conform to a desired switching pattern. The matrix may be heat or sonic welded to its non-conductive support member during assembly. There may be a stacking of switch sections, as shown in FIG. 2, so that a large number of generally similar switch sections may be mounted on a common shaft as is conventional in rotary switches.

The stator sections may be formed of a convenient thermoplastic material and the rotor may similarly be formed of the same material. It is advantageous to have the rotor formed of a slightly resilient material so that the drive shaft is press-fitted into the rotor center hole, thus eliminating any backlash between the shaft and rotor.

It is important to note that the outer cylindrical wall 68 of the rotor completely encloses the actual contact switching area of the matrix 24.

Whereas the preferred form of the invention has been shown and described herein, it should be realized that there may be many modifications, substitutions and alterations thereto.