Organ stop control apparatus

This invention relates generally to an organ stop control apparatus which provides a visual indication of the stops being played.

Usually the stops of an organ are operated by a plurality of stop tablets or draw knobs which are moved from one physical position to another to obtain a particular stop selection. The operational condition of the stops can be determined by observing the location of the tablets or draw knobs. This arrangement, while having the advantage of traditional appearance, is nonetheless somewhat bulky, expensive and cumbersome in operation.

A stop tablet control system that does not rely on the physical location of the tablets for indication of stop selection is disclosed in U.S. Patent No.4,157,051, wherein a multiplicity of stop tablets are pivotally supported on a tablet rail and spring biased to assume a neutral position from which they can be momentarily moved up or down against the action of the spring, and an electrical latching circuit adapted to be latched into one or the other of two stable states by a pulse produced upon momentary movement of the stop tablet. When a tablet is momentarily pushed downwardly from the neutral position the circuit is latched into a first state in which the associated stop is turned "on" and a light-emitting diode mounted on the operated stop tablet is energised, and when the tablet is moved upwardly from the neutral position the associated stop is turned "off" and the light-emitting diode is extinguished. Thus, the operational condition of the stops can be determined by observing which tablets are illuminated. This arrangement, while preserving the traditional appearance and conventional operation of organ stop switching systems, still requires the use of bulky and relatively expensive individual stop tablets.

U.S. Patent No. 4,023,457 describes a stop control system for an organ which instead of using tablets or draw knobs, employs a plurality of touch-sensitive switches for operating a plurality of associated latching circuits. The switches are included in a panel adapted for mounting on the organ console, and are disposed in groups associated with given organ manuals or functions. Within the groups, the switches are disposed in pairs connected respectively for setting and resetting the corresponding latching circuit which operates a designated organ stop, and controls an indicating lamp disposed in proximity to the pair of touch-sensitive switches employed for operating the. latching circuit, thereby indicating to the organist the condition of the particular stop. This arrangement, while permitting accommodation. of a greater number of stops on a given organ console than when tablets or draw knobs are employed, does not have the appearance of traditional stop tablet controls, and the action taken by the organist in effecting stop selection is quite different, and requires greater deliberation, than when playing conventional organs.

It is a primary object of the present invention to provide an organ stop control apparatus which is compact, inexpensive, and easy to manufacture, is readily accommodated to use with organ systems of different complexities, and which largely preserves the appearance and stop selection action of traditional stop tablet control systems.

According to the present invention, stop-control apparatus for an organ comprises a plurality of latching circuits associated respectively with individual organ stops and which energise circuitry for affecting the tonal quality of the organ; an elongate panel having a multiplicity of apertures therethrough arranged in at least first and second vertically spaced horizontal rows and a plurality of horizontally spaced vertical columns, the apparatus comprising a plurality of touch-sensitive switches of which at least some are arranged in pairs connected for setting and resetting a corresponding latching circuit, the switches of each pair being disposed proximate an aperture in the panel and respectively below and above the aperture in the direction of the panel surface; and indicating lamps responsive to respective conditions of each of the organ-stop latching circuits for indicating the state of each latching circuit, each lamp being aligned with the aperture in the panel disposed between the pair of touch-sensitive switches employed for operating its respective latching circuit; characterised in that the apparatus further includes a common surface layer overlying the elongate panel and providing a substantially flat overall front surface for the panel, the surface layer being so constructed that the switches are operable to set and reset the latching circuits by touching the said surface layer or directly touching switch contacts lying in the surface layer, and that the indicating lamps are visible through the panel surface layer only when energised, the surface layer having displayed thereon a plurality of outlines each positioned to circumscribe a different pair of switches and their associated indicating lamp. The surface layer is preferably substantially opaque to ambient light. The indicating lamps are preferably light-emitting diodes, responsive to respective states of each of the latching circuits, thereby indicating to the organist the condition of the particular stop. The light-emitting diodes are disposed behind the substantially opaque front graphics panel and are visible only when the associated stop is selected. ^«

The support panel, and the touch-sensitive switches, are of modular design to provide a high degree of universality; that is, the support panel is constructed to receive, at selectable locations thereon, a number of switch assemblies sufficient to control the stops of a given organ, the number of which will vary with the sophistication of the organ, so that only the graphics on the front panel need be changed to accommodate the control panel to organs having different functions. Thus, the panel can be used, with modification of only the graphics panel, on several different organ models, thereby to realise economy of scale on common parts and attendant reduction in manufacturing cost.

The invention will become better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings wherein:

• Figure 1 is a plan view of a portion of an organ stop switching system panel embodying the present invention;
• Figure 2 is an exploded fragmentary perspective view of the Figure 1 panel, illustrating mounting structure and assembly of the panel;
• Figure 2A is a fragmentary plan view showing an alternative configuration of the front surface of the Figure-2 panel;
• Figure 2B is a fragmentary plan view of a portion of an organ stop control panel illustrating an alternate shape of the "tab" outline;
• Figure 20 is a fragmentary plan view of a portion of an organ stop control panel illustrating still another alternate shape of "tab" outline; and
• Figure 3 is a plan view of a portion of the panel support structure.

A flat panel 10 (Figure 2) is mounted on the upper portion of an organ console, above the organ keyboara or manuals. As best seen in Figure 2, the panel is of sandwiched construction, consisting of an elongate flat supporting panel 12, preferably in the form of an aluminium extrusion, a plurality of membrane-type touch -sensitive switches 14, and a front surface layer 16. Panel 12, fragmentary portions of which are shown in Figure 3, has a multiplicity of apertures 18 therethrough arranged in three vertically spaced horizontal rows 20, 22 and 24 and a plurality of horizontally spaced vertical columns 26 and 28, it being understood that the pattern fragmentarily shown in Figure 2 is continuously repeated, as shown in Figure 3, throughout substantially length of the panel. Typically, the spacing between rows is 2.5cm and the spacing between columns is 1.9cm. The extrusion has a pair of integral vertically spaced parallel extending bosses 30 and 32 on the back face to which a circuit board 33 containing latching circuitry for operating the organ stops and controlling energisation of indicating lamps, is attached by a plurality of self-tapping screws. The indicating lamps, preferably light-emitting diodes, two of which are shown at 34 and 36, extend through apertures in the board 33 and are electrically connected to the latching circuitry. Typically, the width of the front face of the supporting panel, between an angularly displaced upper surface 12a and a bottom lip 12b, is approximately 9.5cm. A plurality of holes 38 are distributed along the edge of surface 12a for receiving screws for attaching the panel to the console, a fragmentary portion 40 of which is shown in Figure 2. Near its upper edge the panel has a plurality of elongate narrow slots 42 therethrough distributed along the length of the panel, each being generally centered above four adjacent columns of apertures 18. The slots 42 each receive therethrough an integral tab 14a of a membrane switch assembly 14, the tab having conductive paths for completing circuits between pairs of contacts of a plurality of switches contained within the switch assembly and respective latching circuits contained on printed wiring board 33 secured to the back of panel 12. At a suitable location along its length, typically near one end, panel 12 may have a plurality of vertically oriented slots 43 therethrough, three of which are shown, dimensioned to receive therethrough slide controls for adjusting rhythm tempo, rhythm level, accompaniment level and the like. The slots are positioned between and equidistant from adjacent columns of apertures 18 and may be utilised or not as the features and functions of a particular organ model may dictate.

Membrane switch 14 includes first switches 50 arranged in a first horizontal row and a second plurality of switches 52 disposed therebelow in a second horizontal row, with the corresponding switches in the rows, say switches 50a and 52a, being arranged in vertical columns. The adjacent switches from each column form a pair, for example, switches 50a and 52a, for controlling the "on" and "off" condition of a given organ stop. Although not shown in Figure 2, a membrane switch assembly, or module, includes four such pairs of switches uniformly distributed along the first and second horizontal rows, and four additional such pairs of switches, one of which comprises the pair 54a and 56a, arranged in third and fourth horizontal rows disposed below and spaced from the rows containing switches 50 and 52. In between and in vertical alignment with the switches constituting each pair is an aperture 58 which, in turn, is in register with an aperture 18 in support panel 12, in which indicator lamps supported on circuit board 33 are received to inform the observer whether a particular organ stop Is actuated. For instance, indicator lamp 34, the tip of which is essentially flush with the front surface of the membrane switch in the assembled panel, will, if illuminated, indicate that the particular organ stop controlled by switches 50 and 52 is in an "on" or actuated condition. It will be evident that the modularly designed membrane switch has, in the described example, eight pairs of switches, each of which pairs having an aperture 58 for receiving an indicator lamp. The switches 50, 50a, 52, 52a, 54a and 56a are suitably touch-sensitive momentary contact switches provided with a front deformable plastic membrane having a conductive pattern on the rear surface thereof, which pattern completes a circuit between adjacent, spaced contacts thereunder, when the membrane is depressed. Suitable switches are manufactured by Centralab Electronics, Milwaukee, Wisconsin, and by other manufacturers including Molex, Downers Grove, Illinois. Although pressure sensitive switches of this type are preferred, capacitive switches or switches wherein the human body completes a circuit between printed conductive patterns may alternatively be employed. In this last case, access to the switches is made through the front surface layer 16.

The front surface layer 16 has length and width dimensions corresponding to those of the flat front surface of panel 12 and preferably consists of a thin sheet of polycarbonate material, such as "Lexan", having a matte front surface and to the back surface of which paint of various colours is applied to provide the graphics illustrated in Figure 1. Desirably, the completed panel has a "dead front" appearance, either black or dark brown in colour; for purposes of illustration the steps involved in the fabrication of a black panel will be described. Initially, an essentially transluscent grey paint is applied to the back surface of layer 16, over which paint of other colours is applied, by a screening or lithographic process, to define a plurality of outlines 60 (Figure 2) each of a shape generally corresponding to the shape of a conventional stop tablet; that is, each outline is generally rectangular with one enα squared off and the other end rounded and having its longer dimension vertically directed. For a control panel having the illustrated two horizontal rows of "tabs", each outline typically is 3.2cm long and the outline has a width of 0.13cm. The stop tab-representing outlines are arranged in horizontal rows and vertical columns to be in registration with respective pairs of touch-sensitive switches contained in switch assembly 14. For instance, the leftmost outline 60 in the upper row is centered around switches 50 and 52 such that the associated indicator lamp 34 extending through aperture 58 is disposed substantially centrally of the outline. The switches and their respective tab-representing outlines 60 are suitably arranged in groups, such as groups 70 and 72, according to the keyboard or function controlled thereby. In the illustrated example, grouping 7Q comprises the stops for rhythm selection, and grouping 72 comprises the stops for the pedal keyboard. Just as different coloured tablets are conventionally employed to differentiate groups of tabs according to the keyboard or function controlled thereby, all of the tab-representing outlines 60 in a particular grouping are printed in one colour, and the "tabs" in other groupings are printed in other colours. For example, all of the "tab" outlines in grouping 70 may be blue in colour, and the "tab" outlines in group 72, yellow. Paint of other colours, if sufficiently bright to be visible under ambient light conditions in spite of being applied over the grey background paint, may be used to distinguish other groupings. The names 62 of the stop tabs, and the names of the various categories of effects and box lines, are all preferably displayed in silver for aesthetic reasons,and clear visibility. In addition to tab and group names, the logo of the manufacturer, the name and number of the organ model, labels for the slide controls and power switch, etc., may be applied to the rear face of the panel in the same way. Thus, the inconvenience and cost of providing separate nameplates, escutcheons, etc., normally found on conventional stop control panels is eliminated.

Following application of the described graphics, opaque black paint is applied thereover, except for small circular areas, indicated by the dotted line circles 74, which are in register with the LED- receiving apertures 53 and 58 in switch assembly 14. The painted back surface is then coated with an adhesive for securing it to the front surface of the switch assemblies. Thus, the front surface of the panel, including the areas circumscribed by outlines 60 (except for circular areas) is opaque black, while the circular areas are only "light black" because they are covered with only translucent grey paint; however, because of the sandwiched construction, little or no light is reflected from the circular areas 74 with the consequence that when the LED's are off, the whole area (except for the graphics) appears'black, or "dead", and nothing behind the graphics sheet is visible from the front. However, when an LED is illuminated,'in response to slight depression of the surface layer in the region of the lower end of a tab-representing outline 60, it appears to pop out from nowhere and is clearly visible to the observer and indicates the "on" condition of the stop with an illuminated spot (preferably red) disposed centrally within the associated outline.

The sandwiched construction protects the painted back surface of sheet 16 from abrasion and reactive chemicals, and since the front face of the sheet has nothing applied thereto, the,panel is very durable and not subject to wear. The latching circuits 35 are suitably of the configuration described in U.S. Patent No. 4,023,457 and are so connected to respective switch pairs that closure of the lower switch of the pair turns "on" the associated stop and illuminates the associated indicator lamp, and closure of the upper switch of the pair turns the stop "off" and extinguishes the indicating lamp. Thus, the physical action of turning stops on and off is very similar to that involved in the actuation of conventional stop tablets, and provision of tab names within the tab-representing outlines, groups of which are distinguished from each other by colour, also makes the tab selection process comfortably familiar. The departure from traditional stop tablets is much less than in the U.S. Patent No. 4,023,457 system in which the "on" and "off" switches for a given stop are physically separated by a considerable amount with only their vertical alignment suggesting that they are associated with the same stop; thus, tab selection requires more deliberate thought and action than is required with the present stop control panel.

While the switches associated-with particular organ stops have been described and illustrated as pertaining to a representative small number of groups for particular manuals or functions, the modular construction of the support panel 12 and the switch assemblies permits the stops of an organ to be organised in other groupings, or in a lesser or greater number of groupings, as desired, simply by altering some wiring connections and the graphics applied to the common surface layer 16. Assuming, for example, that the stop control panel of Figure 1 is intended for use with a relatively sophisticated organ, it can be adapted for use with a less sophisticated organ system simply by providing a surface layer having different graphics appropriate to the functions to be controlled, and possibly eliminating some of the modular switch assemblies. For instance, such less-sophisticated, and concomitantly lower-cost organ, may not contain the PEDAL feature; thus, the graphics would not include tab-representing outlines for the underlying four switch pairs required for control of these functions and the four switch pairs simply would not be connected to respective latching circuits. If the four tabs directly below the "PEDAL" tabs should also be dispensed with in the less sophisticated model, the modular switch assembly carrying the associated eight pairs of switches (four pairs in each of the upper and lower rows) could be dispensed with and replaced with a filler having the thickness of the membrane switch assembly. Alternatively, the switch assembly associated with the deleted tabs could be retained and used with other tab outlines re-arranged on the graphics panel to partially or completely fill the void left by removal of the eight tab-representing outlines. This is all possible by virtue of the repeating pattern of apertures 18 in support panel 23 and the cooperating pattern of apertures 58 and switch contact positions in the membrane switch modules.

In the description thus far, the reasons for the apertures 18 in intermediate horizontal row 22 which, it will be recalled, is positioned substantially equidistantly from rows 20 and 24, has not been discussed. The apertures in this row are aligned with a plurality of apertures 53 formed in membrane switch 14 disposed in between the innermost contacts of the switch pairs of the top and bottom rows of switches. The spacing between the innermost contacts of the switch pairs of the top and bottom rows (e.g. contacts 52 and 45a) is typically 0.6cm larger than the spacing between the contacts of the switch pairs (e.g. contacts 50 and 52 or contacts 54a and 56a), .thereby making it possible to scale up the size of the tab-representing outlines on the graphics panel without changing the construction of support panel 12 or switch assemblies 14. This gives the panel construction the added flexibility of using only a single row of tab-representing outlines, instead of the two shown in Figure 1, simply by changing the graphics on common surface layer 16. In this case, the stop tab outlines are scaled up in both length and width to have essentially the same shape as outlines 60, and are centered between the top and bottom edges of th( panel, as illustrated in Figure 2A. The increased width of the outlines 60' is accommodated by skipping a vertical column of switch contacts between adjacent tab outlines. With this modification of the graphics, light-emitting diodes supported in apertures 18 and 53 in the intermediate row are centrally positioned within the tab outlines 60', as shown at 74 in Figure 2A, in between and spaced substantially equidistantly from switch contact 52 in the lower of the upper two rows of switch contacts and contact 54a in the uppermost of the two lower horizontal rows of switch contacts. The tab-representing outlines 60' are sufficiently long to circumscribe these contacts, which are connected to an associated latching circuit in a manner such that depression of contact 54a turns "on" the stop associated with the particular tab and energises the indicating lamp, and depression of contact 52 turns the stop "off" and extinguishes the indicating lamp. In this case, contacts 50 in the uppermost horizontal row and contacts 56a in the lowermost horizontal row are not connected to latching circuitry, but may be used, if desired, to control other functions related to the particular organ voice associated with the "tab". In any case, the savings in manufacturing cost realised from the use of the universal support panel 12 and modular switch assemblies 14 far outweighs the cost of providing unused switch contacts.

The advantage of the described panel construction that only the graphics on the front cover sheet 16 need to change to accommodate the panel to different organ models also extends to changes in the aesthetic appearance of the panel. For example, should it be desired to change the shape and/or general appearance of the tab-representing outlines, this can readily be accomplished simply by changing the graphics. One alternative form of outline, shown in Figure 2B, has a rectangular outer perimeter 80 and an inner perimeter 82 of a shape generally corresponding to the shape of a conventional stop tablet, that is, with the upper end squared off and the lower end rounded. The outline is printed in a distinguishing colour, and the area 84 within the outline is the same opaque colour as the background area 86 of the panel, for example black or dark brown. The name 88 of the stop is applied near the upper end of the opaque circumscribed area 84, preferably in white or silver.

Another alternative outline shape, simulative of the rocker tablets used on some organs for stop control, is illustrated in Figure 2C. In this case, the outline printed in a colour that contrasts with the background (typically black or dark brown) is significantly wider than in the earlier-described embodiments and is defined by a small rectangle 90 within a larger rectangle 92. The area within rectangle 90 is the same colour as the background 94, the name 96 of the tab is printed in white or silver on the outline colour, and the translucent area 74 through which an energised LED is visible is disposed centrally of the inner rectangle.

It will be understood that each of the alternative outline shapes shown in Figures 2B and 20 may be sized to allow either two horizontal rows of outlines as shown in Figure 1 or one row as shown in Figure 2A.