Description:
BACKGROUND OF THE INVENTION
Since the switch of the present invention is especially adapted for electronic organs, it will be described in that connection, but no limitation is intended by such reference. Switches of the type under discussion have solenoid operated levers which actuate auxiliary switches, which in turn actuate or control components of the organ. For appearance purposes, it is necessary that the levers of a bank of switches be in aligned condition when they are in their "off" rest positions, and also be aligned when they are in their "on" rest positions. Switches of this type as are known to me to be presently available are either relatively expensive and reliable, or less expensive but somewhat unreliable. Also, the mechanism providing for adjustment of the rest positions lever of a switch is somewhat complicated and in certain instances it is disposed in the way of readily mounting the switch in place and necessitates partial disassembly of the switch in order to facilitate mounting. Such switches also have other disadvantages which will be apparent hereinafter.
SUMMARY OF THE INVENTION
The present invention has for a main object to provide a switch which is relatively inexpensive, but is reliable, and to provide such a switch that can be readily mounted in place in fully assembled condition.
These objects are in part carried out (1) by providing a printed circuit board which contains not only part of the energizing circuits for the solenoid coils, but also the electrical elements for a controlled circuit; and (2) by providing special fasteners which not only mount the board on the solenoid coils but also function as adjustable stops for the lever to determine not only its throw, but also its end positions.
Another object is to provide an improved fulcrum for the lever, by indenting the ends of a bearing needle into a mounting plate.
A further object of the invention is to provide a novel overcenter mechanism for a lever, which also actuates an auxiliary switch in the control circuit. This is achieved by providing a pair of permanent magnets, one on the lever and one on the board, mounted in opposing relationship and also arranged to actuate a reed switch which is part of the controlled circuit on the board.
Another object is to prevent the magnetic field of the solenoid coils from interfering with the operation of the reed switch. This is achieved by providing on the lever a shield plate disposed between the coils and the reed switch.
The subject matter which I regard as my invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. The invention, however, both as to organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings wherein like reference characters refer to like elements.
DRAWINGS
FIG. 1 is a side elevation of a switch embodying the invention, parts being broken away for convenience in illustration;
FIG. 2 is a rear elevation of the switch;
FIG. 3 is an enlarged fragmentary horizontal section taken along line 3--3 of FIG. 1;
FIG. 4 is an enlarged fragmentary horizontal section taken along line 4--4 of FIG. 1;
FIG. 5 is an enlarged fragmentary sectional view taken along line 5--5 of FIG. 1;
FIG. 6 is a partial side elevational view of the switch taken from the opposite side from that of FIG. 1;
FIG. 7 is a circuit diagram including the switch of FIG. 1;
FIG. 8 is a side elevation of a preferred form of the switch taken from the same side as FIG. 1 is taken;
FIG. 9 is an edge view of the switch of FIG. 8; and
FIG. 10 is a partial side elevational view of the switch taken from the opposite side of that shown in FIG. 8.
The switch S includes a generally rectangular mounting plate 11, each end portion of which has a slot 13 (FIG. 2) by which the plate can be mounted in place by screws 15. FIG. 1 shows the mounting plate affixed to the rear face of the front panel 17 of an electronic organ. However, this particular usage is merely illustrative and not meant to be limiting.
It is evident from FIG. 1 that all the other portions of the switch S are clear of the axes 19 of the screws 15, permitting mounting of the switch in place by screw driver operation along lines 19 without interference by parts of the switch, and without having to partially disassemble the switch.
The switch further includes two solenoids having coils 31 and 33, each of which comprises a spool 35 on which wire 37 is wound. Extending through each spool is an iron core 41 which has a reduced left hand portion 43 which is staked into a similar sized hole in the mounting plate to mount the solenoid coil in place.
The right hand end of each core is formed obliquely to the axis of the core so as to be disposed in operative relation with an arcuate armature 51 which is carried by the inboard or right hand end of a lever 53.
In the specific embodiment of the invention shown, since the switch is adapted for use in an electronic organ, the lever 53 is bent at its medial portion so that its left hand end or handle portion 55 extends downwardly at a slight angle to the horizontal in the "off" or elevated position of the lever handle, and extends further downwardly in the "on" position. A plastic handle cover 57 is fixed to the front end portion 55.
The lever extends through an essentially rectangular slot 61 (FIGS. 1, 2 and 3) formed in the mounting plate 11. A single bearing needle 63 is fixedly secured to the obtuse angle corner (FIG. 1) of the lever and has its ends pivotally mounted in the adjacent margins defining the opening 61 whereby the lever is pivotally mounted in place.
In assembly, the slot 61 is made to have a width just slightly exceeding the length of the needle 63. The lever is inserted into the slot, with the needle located in the position shown in FIG. 3. Thereafter the sides of the mounting plate are deformed permanently inwardly as at 64 (FIG. 2) to press them onto the ends of the needle. The needle is much harder than the plate so that the needle ends indent into the plate margins and form suitable sockets in which the needle ends can pivot. This arrangement provides long life pivotal action for the lever with a minimum of wobble.
The preferred form of needle end is one that a somewhat abrupt frusto-conical portion from which protrudes a less abrupt essentially conical portion.
It is contemplated that switch S will be mounted in a bank with other similar switches. It is desired that the outer ends (handles) of all the switches be disposed at the same inclination when similarly positioned. To enable the switches to be adjusted so that their handles are at the same inclination, an adjustment system has been provided. It comprises a pair of adjustment means associated respectively with the solenoids 31 and 33, each means being mounted on a bracket 71 (FIG. 4). Such adjustment means also mount a printed circuit board 73 on such brackets.
Referring particularly to FIGS. 1 and 4, each adjustment means includes a cam 81 into which a tri-lobular adjustment screw 83 tightly threads in an unthreaded hole in the cam. Thus, the cam can be considered a nut. The lock screw 83 passes through a hole (FIG. 4) formed in the associated bracket 71 and through a hole formed in a margin of the circuit board 73.
The frictional fit of the tri-lobular lock screws 83 in the cams 81 creates a frictional resistance which is greater than the clamping friction resistance on the brackets 71 and the circuit board 73 so that the screws may be turned to adjust the cam positions without unthreading or further threading the screws relative to the cams.
As is evident from FIG. 1, each screw 83 is threaded into its cam 81 in offset relation to the axis of the cam to provide a cam lobe which can be variously located about the axis of the screw.
The lever 53 carries two resilient impact cushioning pads or bumpers 101 (FIG. 1) which, at the end of the travel of the lever, engage the peripheral surface of one or the other of the cams 81. If it is desired to locate the "off" position of the handle 57 at a lower level than as shown in FIG. 1, the lower cam 81 would be turned which would raise the associated pad 101, which in turn would depress the handle 57 of the lever. Similarly, the "on" position of the handle 57 could be raised by adjusting the upper cam 81. The resilience of the pads is a factor making adjustment of the rest positions of the lever necessary.
The armature 51 has a central slot to receive a narrow inboard portion end 53' (FIG. 5) of the lever 53, and is secured in place by solder. The pads 101 are adhesively secured to the inboard end of the lever alongside the armature 51 in position to engage the adjustment cams 81 at the ends of the travel of the lever.
An overcenter compression spring 105 has one end pivotally mounted in an indentation in the inboard end of the lever, whereas its other end is bent to pass through a tube 107 (FIG. 5) mounted in the circuit board. The compression spring 105 is under stress in the position shown in FIGS. 1 and 5, and this stress is increased upon upward movement of the right hand (inboard) end of the lever. This resistance must be overcome in order to shift such inboard end from its lower position to its raised position. This provides an overcenter action for the lever.
The circuit board 73 contains portions of a controlled circuit which portions are shown in FIG. 7. The controlled circuit affects one or more components of an electronic organ, and includes four contact posts 111, 113, 115 and 117, which comprise part of an auxiliary contact switch means. These posts are mounted on and extend through the board 73 and are in electrical contact with the metallic contact layer (FIG. 6) on the opposite side of the board from the insulated side shown in FIG. 1.
A spring contact, generally labeled 131 (FIG. 1) has one end portion 133 in constant engagement with post 115. The spring is bent to provide a loop portion having a first hump portion 135 and a second hump portion 137 and an angular portion 139 whose free end pivots in an indentation in the inboard end of the lever 53.
Post 115 is connected by a conductor 140 (FIGS. 6 and 7) to a source of electrical power, 12 volt regulated power in the particular circuit shown.
The operation of the switch will be explained with reference to the right hand or inboard end of the lever 53 in FIG. 1, rather than the left hand end, for convenience in description.
FIG. 1 shows the switch S in its "off" position, with the inboard end of the lever down. At this time the wire contact 131 is in engagement with post 117 (compare FIGS. 1 and 7). This means that twelve volt power from the conductor 140 (FIG. 7) is transmitted by wire contact 131 from post 115 to post 117, and from the post 117 and a conductor 141 to an external circuit to affect the same in a desired manner.
To magnetically move the switch to its "on" position, a manual switch 142 (FIG. 7) is closed, whereby to energize the coil 31 through conductors 143 and 145 (compare FIGS. 6 and 7). Coil 31 pulls armature 51 upwardly, as the parts are shown in FIG. 1, to bring the upper pad 101 against the cam 81 associated with such coil. The upward movement of the inboard end of the lever deforms the wire contact 131 (FIG. 1) to bring hump 135 against contact posts 111 and 113, and move hump 137 away from post 117. This transmits twelve volt power from conductor 140 (FIG. 7) to the external controlled circuit by means of conductors 147 and 149 (compare FIGS. 6 and 7) to affect the external controlled circuit in another desired manner.
To magnetically throw the switch S to its "off" position, a manual switch 156 (FIG. 7) is closed to energize the coil 33 through conductors 145 and 157 (compare FIGS. 6 and 7). This again brings the wire contact into engagement with post 117 (FIG. 1 position).
FIGS. 8, 9 and 10 show the preferred form of switch S 1 which includes many of the features of the FIG. 1 switch, but has reed switches, magnetically operated, rather than contact switches, as does switch S. Thus, switch S 1 has a mounting plate 11, a lever 53 having an arcuate armature 51 which is operatively related to a pair of coils 31 and 33, mounted on the mounting plate 11. The coils 33, by means of adjustment screws 83, mount a printed circuit board 73a in stand-off relation to the plate 11. Adjustment screws 83 non-rotatably fit in cams 81a which serve as adjustable stops for bumpers 101 on the lever 53 to determine the rest positions of the handle portion of the lever.
The coils 31 and 33 are energized by a circuit like that in FIG. 7, which is not believed necessary to detail, because the elements thereof will be apparent to those skilled in the art by a comparison of the disclosure in FIGS. 6 and 10.
The S 1 switch differs from the S switch in the following respects. The printed circuit board 73a carries a pair of reed switches 201 and 203, switch 201 being mounted at 205 and 207 (FIGS. 8 and 10), and switch 203 being mounted at 209 and 211, on the printed circuit board. The reed switches control one or more exterior circuit components by conductors 213, 215, 217 and 219. The circuit board carries a pair of diodes 221 and 223 which are part of the reed switch circuit.
A pair of permanent magnets 231 and 233 are employed for actuating the reed switches, and for obtaining an overcenter action on the lever. Magnet 231 is mounted on the inboard end of the lever 53 and can assume a position slightly below the horizontal centerline of the magnet 233 (as the parts are depicted in FIG. 8) when the lever is in the "off" position, or a position slightly above such centerline, when the lever 53 is in its "on" position. When the magnet 231 is in its "off" position (FIG. 8) it closes switch 201, whereas when it is in its elevated position, it energizes reed switch 203.
The two permanent magnets are magnetized oppositely --are in opposition--so that an overcenter action is achieved.
Permanent magnet 233 is mounted on the printed circuit board by means of a split steel holder 251 (FIGS. 8 and 10), which fits in an opening in the printed circuit board. The two pieces are soldered in place, as indicated in FIG. 10. The split in the holder increases the magnetic field variation (as the switch is toggled from one to off) at the reed position, by eliminating a detrimental magnetic short circuit.
Since in many instances, it is contemplated that the switch of the present invention may be arranged in banks, it is possible for the coils of neighboring switches, as well as the coils of its own switch to adversely affect the operation of the reed switches. To prevent this, a metal plate-like shield 253 is mounted adjacent the inboard end of the lever 53 beneath the magnet 231 to prevent erratic performance of the reed switches as might otherwise be caused by the action of the coils 31 and 33, or the coils of adjacent switches.
The operation of the S 1 switch is basically like that of the S switch in that the lever 53 can be manually operated when desired, or magnetically operated by remote switches such as at 141 and 146 in FIG. 7. When the switch is in one position, one of the reed switches is closed to affect the controlled circuitry one way, and when the lever is in the opposite position, the other reed switch is closed to affect the controlled circuitry another way.