Avionics channel selection apparatus
United States Patent Wisser et 211.  
 [451 Apr. 22, 1975 AVIONICS CHANNEL SELECTHON APPARATUS [75] Inventors: William L. Wisser, Line Lexington;  
 Louis C. Ammlung, l-latboro; Howard M. Schenkel. Ambler. all of Pa.  
 [73] Assignee: Narco Scientific industries, inc Ft. Washington. Pa.  
 [22] Filed: Aug. 12. 1974 [21] Appl. No.: 496,612  
 [52] US. Cl 334/86; 116/1242 R; 334/47 [51] Int. Cl. H03j 1/02 [58] Field of Search 334/39, 47. 86-87; 116/1242. 124.2 A. 124.3. 124.4  
 [56] References Cited UNITED STATES PATENTS 1.735.171 11/1929 Kunzc ..11o/124.2R  
 2.530.541 11/1951) Roth 116/1243 Primary Emminer-Alfred E. Smith Assistant E.\&#39;aminerwm. H. Punter Attorney, Agent, or Firm-Paul &amp; Paul [57] ABSTRACT First and second coaxial shafts respectively operate first and second kilohertz range frequency channel display drums by corresponding gears. The shafts each terminate on one end with wafer switches electrically connected to tuning apparatus, and at the other end by colinear. coaxial knobs which may be operated jointly or independently by the user. A pair of megahertz range display drums are coupled together by Geneva gear apparatus. and are operable together by a third shaft which also terminates in a rotary wafer switch.  
 9 Claims. 4 Drawing Figures AVIONICS CHANNEL SELECTION APPARATUS BACKGROUND OF THE INVENTION This invention relates to avionics channel selection apparatus.  
  One area to which human factors engineering has been most assiduously and most productivelyapplied has been that of aircraft instrumentation. Increasing sophistication of the aircraft themselves has given the pilot more tasks to perform and correspondingly more meters, gauges. and sundry displays to monitor. While the problem of effective arrangement of these various devices has been most critical in very large passenger and military aircraft, the problem exists even in the smallest of private aircraft, and is particularly acute for a relatively inexperienced pilot.  
  There exists a special need for avionics communication apparatus to have displays which are easy to read, and to have channel selection apparatus which may be quickly and effectively adjusted. For example, the frequency band which has been allocated to avionics communications is divided up into a large number of channels. At all times during the flight, and particularly at times of takeoff and landing, it is absolutely essential that the pilot be able readily to observe the channel to which his transceiver currently is set. and quickly and easily to change that selection, as desired. to a specified channel upon which he must communicate. That is to say, during times of takeoff and landing. it is especially important that the pilot be diverted as little as possible from the main task at hand to observation and manipulation of his communication channel selection apparatus.  
 SUMMARY OF THE INVENTION The present invention is directed to communication channel selection and display apparatus which may be most conveniently operated by the pilot without distraction from his other tasks. In accordance with the principles of the present invention. kilohertz range display is divided into two separate display means, each being operable by separate actuating knobs and shafts. Moreover, in preferred embodiments, the shafts are coaxial and the knobs are disposed colinearly and coaxial with one another, such that they may be manipulated independently or jointly by the pilot. The shafts are coupled by appropriate gear mechanisms to the display means, and rotary wafer switches are attached respectively to the shafts. A separate shaft and gear assembly operates coordinated megahertz range display means. Each of the rotary switches is configured to contact selectively and fixed terminals, which in turn lead to a decoder and to a tuning stage of the communication apparatus.  
 DESCRIPTION OF THE DRAWINGS FIG. 1 shows a top view of channel selection apparatus embodying the principles of the present invention;  
  FIG. 2 shows a cutaway ofa portion of the FIG. 1 apparatus;  
  FIG. 3 shows a sectional view of the FIG. 2 apparatus; and  
  FIG. 4 shows the interaction of mechanical and electrical apparatus embodying the principles of the present invention.  
 DETAILED DESCRIPTION In its particulars, the preferred embodiment described hereinafter relates to a 720 channel communication unit. In accordance with relevant FCC and FAA regulations and frequency band allocations, the total operating band extends between 1 18.000 and 135.975 megahertz, with each of the 720 channels being 25 kilohertz wide.  
  As set forth in the drawings, all of the mechanical channel selection apparatus is disposed within a modular chassis 100 which may be installed or withdrawn from an instrument panel as a unit. Centrally located within the housing 100, are four display cylinders 101 through 104, which as shown in FIG. 4 display the currently selected channel through an opening in the front face of the module 100. For the 720 channel unit, display cylinder 101 indicates the units and tens digits in the kilohertz range, display cylinder 102 indicates the hundreds integer in the kilohertz range. display drum 103 indicates the units digit in the megahertz range. and display drum 104 indicates the tens and hundreds digits in the megahertz range. It is also preferred that display cylinder 101 be graduated in increments of 25, display cylinders I02 and 103 be graduated in integer units, and display cylinder 104 being graduated in integer units between I 1 and 13. Thus, for example, if the channel 132.475 were to be selected, the numbers apparent through the front face window in the housing 100 would be showing, with numbers I and 3 disposed on cylinder 104, number 2 on cylinder I03, number 4 on cylinder 102, and the number on the cylinder 101.  
  The megahertz range display cylinders 103 and 104 are controlled by knob 108 through actuating shaft 109, and appropriate gearing mechanism. The operation thereof is described in detail hereinafter. Display cylinders 101 and 102 are operated by means of colinear, coaxial, and substantially adjacent knobs I06 and 107, which respectively operate the cylinders 102 and 101 by means of coaxial shafts Ill and 112. In addition, behind the housing and respectively operated by the knobs 106 through 108 are rotary wafer switch contacts 127, 128 and 142. The function of these switch contacts also is described hereinafter.  
  The lower kilohertz display cylinder 101 is operated as follows. The knob 107 is rigidly connected to the outer coaxial shaft 111, which in turn is rigidly connected to a crown gear 114. The crown gear 114 meshes with a spur gear 116 rigidly connected to the cylinder 101. Thus, rotation of the knob 107 also rotates the lower kilohertz display cylinder 101. The spur gear 116 also is meshed with another spur gear 117, which in turn operates a crown gear 118. The crown gear 118 is rigidly connected by means of another shaft 113, also coaxial to the central shaft 112, and thence to a wafer 128 of a rotary switch. Thus, rotation of the knob 107, by virtue of the cooperation of gears 114, 116, 117 and 118, also rotates the wafer 128. Also affixed to the shaft 113 is a detent assembly having indentation stops corresponding to each reading on the kilohertz display cylinder 101. Detent roller 130 rides in the indentations of the detent gear 124, and is flexibly secured in position by means of a spring 126 attached to the housing 100 by a screw 129. The spring 126 is maintained in downward compression against the roller 130 by means of another screw 131 in the housing 100.  
  The second kilohertz display cylinder 102, occupying the hundreds of kilohertz&#34; position, is operated by means of the knob 106 attached to the central coaxial shaft 112. Rigidly attached to the shaft 112 is a first miter gear 119, which meshes with a traverse miter gear 121. The traverse miter gear 121 in turn is rigidly attached to the cylinder 102. Attached to the end of the shaft 112 opposite the knob 106 is another wafer type rotary switch contact 127. Also centrally mounted on the shaft 112 is a detent assembly including a detent gear 123 and spring 125, which functions identically to the other detent gear 124 described hereinabove. The detent gear 123 is indexed to correspond to the integers of the hundred kilohertz display cylinder 102.  
  As may be seen from the drawings, the shafts and gears are variously supported by the outer walls of the housing 100, or by an upstanding casting 160 therein. While the precise design of the various gears will depend on the degree of rotation which is desired for the respective display cylinders relative to one another, for preferred embodiments the two kilohertz display cylinders 101 and 102 are indexed such that a turning of knobs 106 and 107 by a predetermined degree of rotation when grasped together will turn both cylinders 101 and 102 together to index them successively thus: 000, 125, 250, 375, etc. in order to achieve this coordinated action, the first cylinder 101 has two full cycles from through 75, and the second cylinder 102 has one full cycle from O to 9. Accordingly, the gear combination 114 and 116 should have an effective ratio to that of miter gears 119 and 121 of to 4. That is, each incrementing in the hundreds of kilohertz range on cylinder 102 requires only 80% the turning required to increment the lower kilohertz display cylinder 101.  
  The two megahertz display cylinders 103 and 104 are operated from knob 108 and shaft 109. Rigidly attached to the shaft 109 is a beveled gear 132 which meshes with a transverse pinion gear 133. The transverse gear 133 in turn is affixed on the hub of the cylinder 103 which penetrates cylinder 104 and operates cylinder 103. Thus, rotation of the knob 108 correspondingly rotates display cylinder 103.  
  Display cylinder 103 is configured with a raised portion upon which the megahertz integers are emblazoned, and a depressed portion 170 above which a pin 138 is affixed. in proximity with the depressed portion 170 is the indexing gear 135 of a Geneva assembly 134 and 135. in turn, the spur gear 134 of the Geneva assembly meshes with a larger spur gear 173 affixed to the display cylinder 104. For each rotation of the lower megahertz display cylinder 103, the pin 138 advances the Geneva assembly by an amount equal to successive indentations in the gear 135, and correspondingly increments the second megahertz display cylinder 104. For application in the preferred embodiments set forth above, since only three positions register on the second drum 104, the readable display portion is correspondingly limited.  
  The shaft 109 terminates with a rotary wafer contact 142 of a rotary switch means, and the shaft also has a detent assembly including gear 140, screws 143 and 146, a detent roller 141, and a spring 144. I  
  The cooperation of the tuning mechanisms set forth hereinbefore, the rotary switches 127, 128 and 142 upon which the respective shafts terminate, and the electrical and electronic apparatus which constitute the actual transceiver is shown, symbolically in FIG. 4. In  
 FIG. 4, the chassis 100 is shown, with selected portion of the display cylinders 101 through 104 being evident through a window cut in the front portion thereof. The knobs 106 through 108 are disposed as shown on either side of the display cylinders 101 through 104, and the shafts 109, 111, 112 and 113 are shown in phantom. The three wafer rotary contacts 127, 128 and 142 are each disposed in the proximity of respective pluralities of electrical terminals, which in turn lead to a decoder 401 and to the actual tuning electronics 402 of the transceiver.  
 The contacts 127, 128 and 142 are configured to define a binary coding arrangement for each of the corresponding numbers being displayed by selectively connecting the terminals from the decoder 401 to a ground connection. Accordingly, disposed strategically relative to each of the wafers 127, 128 and 142 are electrical ground connections 403 through 405, each having a brush type contact with the wafers. For the embodiment described herein, the wafers each are composed of a totally conductive material, such that when any of the terminals from the decoder 401 make contact with the associated wafer switch, they are thereby coupled to an electrical ground. Correspondingly, if the terminals are not in electrical contact with the associated wafer switch, they are maintained at some predetermined voltage. Thus, the binary ones and zeros are established.  
  in accordance with the foregoing binary coding arrangement, each of the wafer switch contacts 127, 128 and 142 is configured having a variable radius, with the terminals from the decoder 401 being fixed brush contacts arrayed around the periphery of the wafers, but located beyond the inner radius and within the outer radius. Thus, the position of the wafer switch dictates whether or not a given terminal from the decoder 401 is grounded by presenting either a portion having the outer radius, thereby connecting the terminal to ground, or a portion having the inner radius, thereby excluding the terminal from ground and maintaining it at a prescribed voltage. The precise dual radius configuration for each of the wafer contacts of course depends on the code utilized to represent each of the associated numbers on the display cylinders 101 through 104.  
  For example, as set forth hereinbefore, for preferred embodiments the lower kilohertz display cylinder is graduated in increments of 25, thereby requiring a digital code to represent only four values, i.e., 00, 25, 50 and 75. Thus, a two digit binary code may be utilized to define the four quantities, thereby requiring two leads 406 and 407 from the decoder 401. However, as also set forth hereinbefore, the cylinder 101 may be conveniently inscribed with a repeated pattern, having each of the numbers occurring twice on the cylinder. Accordingly, the wafer contact 127 is symmetric to permit a repetition of the two digit binary code. Therefore, the brush contacts of terminals 406 and 407 may individually be connected to ground, by means of wider radius protuberances 408 and 409, they may be connected together to ground by means of outer radius protuberances 410 and 411, or alternatively they may both be disconnected from ground, whenever the short radius portions, such as the one located next to 407 in FIG. 4, are exposed thereto. Correspondingly, the binary combinations 00, 01, 10, and l 1 may be defined.  
  The hundreds of kilohertz integers on display cylinder 102, being in number, require four leadsfrom the decoder 401 to generate the appropriate number of binary combinations. However, since only 10 of the l6 possible combinations need to be utilized, the rotary contact 128 need not be configured for every possible combination offour binary digits, but rather may be designed more simply. The configuration shown in FIG. 4 for the rotary contact 128 is capable of contacting, and thereby grounding each of the four terminals 412 through 415 individually by means of the outer radius portion 416. Also, the larger outer radius portion 417 may make contact with 414 and 415; 413, 414, and 415; 412 through 415 together; 412 through 414 together; and 412 and 413 together. Finally, none of the four leads 412 through 415 may be grounded, thereby yielding the 10th combination. It is clear, however, that other of the 16 available combinations might be used instead of any of the foregoing ones, merely by rear ranging the position of the respective terminals 412 through 415, or by correspondingly altering the configuration of the rotating wafer element 128.  
  The megahertz display cylinders 103 and 104 are both coupled through shaft 109 to the rotating wafer contact 142, thereby necessitating coded representation of 18 distinct numbers. Accordingly, while as few as five leads might be utilized to generate adequate code combinations, it is more convenient from the standpoint of operation of the rotating switch 142 to utilize eight terminals from the decoder, and to configure the rotary wafer as shown, Thereupon, a sufficient number of possibilities from the various leads will be provided.  
  As shown in the drawing. the various terminals exposed to the rotary switches 127, 128 and 142 are coupled to a decoder 401, which senses the state of the various terminals, and translates the code to an appropriate digital or analog quantity to operate the tuning stage 402. Both the decoder 401 and the tuner 402 may be embodied by any of the apparatus conventionally known for the respective functions.  
  It is to be understood that the embodiment described herein is a preferred realization of the principles of the present invention, but that alternatives may occur to those of ordinary skill in the art without departing from the spirit or scope of the principles of the present invention. For example, the rotatable wafer switch contacts may assume different configurations, or may be composed of nonconductive material and have circuit paths inscribed thereon. Likewise, the labelling of the display cylinders and the gear drive therefor may be varied in accordance with different operating ranges, as described.  
 We claim:  
  1. A channel selection device for avionics transmitters and receivers comprising:  
 first and second frequency display means, said first means being graduated in units and said second means being graduated in fractional parts of said unit;  
 first and second actuating shaft means corresponding respectively to said first and second display means,  
 said shaft means being at least partially coaxial with another;  
 first gear means. coupling said first shaft means with said first display means, for incrementing said first display means a unit at a time in-response to a predetermined degree of rotation of said first shaft means; and  
 second gear means. coupling said second display means with said second shaft means, for incrementing said second display means by a fractional part at a time in response to rotation of said second shaft means by said predetermined degree of rotation;  
 whereby said knobs may be operated jointly and independently to set said first and second display means at selected settings.  
  2. A device as described in claim 1 wherein said first and second shaft means are position quantized by respective detent means having stops corresponding to graduations on associated display means.  
  3. A device as described in claim 1 and further including third and fourth display means graduated in predetermined multiples of said units, said third and fourth display means being operated by a third shaft means; third gear means coupling said third shaft means to said third display means, and geneva gear means coupling said third display means with said fourth display means.  
  4. A device as described in claim 3 wherein said third shaft means is position quantized by a detent means having stops corresponding to graduations on said third display device.  
  5. A device as described in claim 1 and further including: a plurality of fixed electrical contacts disposed about a portion of said first and second shaft means. said contacts being coupled to specified electrical and electronic apparatus; and first and second wafer means respectively affixed to said shafts in the proximity of said fixed contacts, said wafer means having electrical conduction paths thereon to make contact with select ones of said contacts in accordance with rotation of the associated shaft.  
  6. Channel selection apparatus for avionics transmitters and receivers comprising:  
 mechanical selection means including first and second megahertz range display means and first and second kilohertz range display means, said first and second megahertz display means being operated by a first actuating shaft means, and said first and second kilohertz range display means being operated respectively by second and third actuating shaft means, said shaft means each having a rotary switch means attached thereto and rotatable therewith, each of said rotary switch means having a plurality of fixed terminals and a rotatable wafer portion having multiple circuit contacts to be variably coupled to select ones of said terminals in response to rotation of the associated shaft; and  
 variable tuning means coupled to said first terminals and thereby responsive to said mechanical selection means, for generating an electrical condition, corresponding to a selected channel.  
  7. Apparatus as described in claim 6 wherein said rotary switch means each include wafer means having a periphery which steps between first and second radii, said fixed terminals being disposed to contact the associated wafer means when a portion having said second radius is rotated in proximity with the fixed terminals.  
 second and third shaft means are coupled respectively to said first and second kilohertz display means, said gear means being relatively configured to increment said first and second display means together when said second and third shaft means are rotated by an identical. predetermined degree of rotation.  
 UNITED STATES PATENT OFFICE CERTIFICATE OF CORREQTION Patent No. 3,879,692 &#39;Dated April 22, JQ&#39;7&#39;3 Inventor(s) William L. Wisser. Louis C. Amm-lun &amp; Howard qnhpmk l It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:  
 Column 1, line 54, &#34;and&#34; should be with-.  
 Signed and Scaled this twenty-sixth Day Of August 1975 [SEAL] A ttest:  
 RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner uj&#39;PaIenIs and Trademarks