US3311877A - Single station range light - Google Patents

Description

March 28, 1967 T. H. PROJECTOR ETAL I SINGLE STATION RANGE LIGHT 2 She ets-Sheet 1 Filed Feb. 28, 1963 L-B HJIHIlllllllIIHHHIHHIIHIHIIII coA/rm/uaus 50 1 Cal/95E lLHIRNWNNIRIkNIKH I N VENTORS co/vr/lvuous apsw March 28, 1967 -r. H. PROJECTOR ETAL 3,311,877

SINGLE STATION RANGE LIGHT Filed Feb. 28, 1963 2 Sheets-Sheet 2 1 Q CHANNEL u w ///%\B' S/G VAL PRESENTATION TIME.

CONTINUOUS RED A B HIIIH 'IIIHNWIIH HIIHNNIIHHRIHHF sec. 6 fil||k\@WIZIIR\\RYHHIF .3 secs.

ca/vrnvuous GREEN NAV/GATOR pos/r/oN 3,3 l 1,877 Patented Mar. 28, 1967 ice 3,311,877 SHNGLE STATTQN RANGE LIGHT Theodore H. Projector, 3304 Edgwood Road, Kensington, Md. 20795, and Robert S. Rinkinen, 4708 Topping Road, Roclrville, Md. 20353 Filed Feb. 28, 1963, Ser. No. 261,688 20 Claims. (Ql. 340-29) This invention relates to range lights, particularly for river and harbor navigational purposes wherein a navigator is to be guided through a deep water channel of the river, harbor, or the like.

Much development work has been done in the matter of providing beacons for the guidance of navigators in channels and along coasts. Beacons intended to guide mariners along channels (range lights, as they are called) usually take the form of two spaced lights. The two lights are located on an extension of the center line of the section of the channel for which they provide guidance, the one farther away being slightly above the nearer light. When a mariner is on the channel center line, the farther light appears directly above the near light. When he is off the channel center line, the two lights are laterally separated, the amount of the separation being an indication of the mariners distance from the center line.

However, a number of range lights have been developed of the so-called single-station type wherein only one light or assembly of lights at a particular point is used. In the matter of single station range lights, various systems involving multi-color units, flashers and coacting time flashes have heretofore been known. Examples of such single station range lights are shown in prior art patents, such as McKay Nos. 2,570,137 and 2,570,138; Knapp No. 2,531,337; Penton No. 2,458,414; Field No. 2,559,415, and others.

The basic principle involved in a single station system is the provision of means such as lights of different color on each side of white beam to indicate to a pilot whether he is on course, or to the left or right of course, depending on which colored light he sees, or depending on some other manifestation effected by the coacting beams, either with or without a movement of such beams.

The prior arrangements have various drawbacks, such as complexity of mechanism or confusing manifestations, or expensive construction, or the like. Accordingly, it is the primary object of the present invention to provide a simple and dependable single-station range light which can be manufactured economically and which will give a signal more positively recognizable for ofif or on course conditions than those of the prior art.

Other objects and features of the invention will be apparent from the description to follow.

Briefly, the invention contemplates the provision of twin red and green beams integrally mounted for oscillation and steadily illuminated so that the swing of the beams crossing and re-crossing a desired course line in a channel takes place in a particular sequence of angular position, with a dwell of a predetermined time at each position and rapid traverse between positions. Thus, assuming two parabolic reflector type light projectors, integrally connected, one green, one red, are mounted side by side on an oscillatory platform, the axis of the equipment would be a line bisecting the angle formed by the optical axes of the two light projectors. By virtue of mechanical oscillation of the platform around a vertical axis, the center line of the composite beam swings to and fro through a narrow predetermined angle. However, the platform oscillation is such that the composite beam center line is stationary at certain positions in the swing on each side of the course line.

A navigator in the channel can ascertain by the duration of time in which he sees one color of beam as compared with the length of time that he sees the other color whether he is on course or olf course and to what extent. In other words, the navigator sees the light changing from, say, red to green, repetitively, and, depending on the position in which he is relative to the proper course that he is to follow, he will note that one or the other of the lights is seen fora longer period. In that way, he determines whether he is to the left or right of the course. When he sees only one color of light steadily he is apprized of the fact that he is farther off course than when he sees two colors of different time duration. The color that predominates in time duration apprizes him as to whether he is left or right of the course. When he is on course he sees the portions of the composite beam alternate in color, and the colors are of equal time duration.

Ideally the two light beams are adjusted to be precisely divergent so that the inner adjacent edges of their beams are coincident and sharp. Thus, as the composite beam sweeps the channel from side to side, the transition from one color to the other as observed by a mariner would be abrupt and complete. In practice, such precise cutoffs are unattainable, and some overlapping of the two beams at their contiguous edges is unavoidable if a continuous light signal without occulting is desired. The equipment therefore is designed to have adjacent beam edges as sharply defined as is racticable, but there will nevertheless be narrow transition regions in the channel, between the regions of desired signal presentation, where some part of the signal sequence will not be red or green, but some color representing an additive combination of red and green, such as yellow. This does not alter the basic presentations as outlined above, but means that the simple basic presentations are complicated to a small extent by the addition of narrow transition zones between the major, desired signal presentation zones.

As a further engineering modification to form the beams for maximum usefulness, baffles may be added along the inner adjacent edges of the two beams in order to provide essentially flat edges. The object of the beam-flattening baflies is to insure proper transition between the two beams for necessary angles of elevation of the sightline as required by mounting height of the light, ship bridge heights, and tidal actions.

The mechanical arrangement may be very simple and can consist of an oscillatory platform on which the lights are mounted to beam out on both sides of the course line which intersects the oscillatory axis. Any suitable linkage arrangement, which may include a cam, can be arranged to oscillate the platform and, hence, the integral red-green light assembly with respect to the course line. The layout of the cam in the present disclosure provides four angularly related dwell positions having a rest time of about one second each.

The lamp assembly swings very rapidly, in perhaps a tenth of a second, between positions. The sequence of movement to the various dwell positions, assuming four geometrically consecutive angular positions is in the order 132-4 and on each movement between dwell positions the juncture of the composite beam crosses the channel course line. Such oscillation is continuous and the effect is to provide a difference in the length of time each color is seen by a navigator depending on his position with reference to the course line.

The time interval of one second dwell at each of the four positions described above is, of course, arbitrary. Diiferent conditions may indicate variation therefrom and, of course, it is only the design and/or speed of the cam which needs to be changed to produce longer or shorter dwell periods.

A detailed description of the invention now follows, in conjunction with the appended drawing, in which:

FIG. 1 is a diagrammatic plan view of the layout of two parabolic reflectors for red and green beams respectively, and illustrating a mechanical actuation arrangement for four dwell positions;

FIG. 2 is a diagram of a section through 2-2 of FIG. 1, it being understood that the section is greatly distant from the equipment, representing a section through the beam as it might be found in an actual channel;

FIG. 3 is a plan diagram of a river or harbor channel showing the presentation of the composite beam extending into the channel for four dwell positions;

FIG. 4 is a time study chart of the relative durations of specific light color seen by a navigator in various positions in the channel illustrated in FIG. 3;

FIG. 5 is a plan diagram of a system using two dwell positions, and;

FIG. 6 is a time study chart similar to FIG. 4, but for a two dwell position system.

Referring now to FIG. 1, a pair of light projectors, consisting of parabolic reflectors 10 and and lamps 13, and color filters 10a and 15a, red and green, respectively, are represented having approximately collimated beams with center lines 18 at a slightly divergent angle such that the adjacent beam edges are parallel. A battle plate or shield 20 may be disposed in any suitable manner intermediate the beams, in order to flatten the beam edges at the juncture (FIG. 2).

The lights and the baflie may be integrally mounted on support means such as the plate 22, suitably carried on a rotative vertical shaft so as to be oscillatory about the shaft axis, in a horizontal plane. The line M which extends intermediate the lights from the axis of the oscillatory shaft and in a horizontal plane, is the center line of the light configuration and such line oscillates across the desired course line K of the channel (FIG. 3) through a predetermined angle that is necessarily narrow for accuracy. The sweep or swing may be of the order of from one to ten degrees for practical operation under most conditions, as exemplified by the arc IV between lines A and D (FIG. 3), drawn to a somewhat larger angle for clarity, however.

Oscillation of plate 22 is effected by a linkage system comprising the link .pivoted thereto and also to a link 33 having apertures 40, which rocks about a fixed pin or hearing 37 within an aperture 40. Link 33 may have several apertures 40, as shown, so that adjustment of the position of bearings 37 with respect to the linkage may be made, in order to change the amplitude of oscillation of the plate. A tension spring 43 has one end connected to link 33 and the other end fixed so that the link 33 is always :biased in a direction which will effect clockwise rotation of plate 22. A cam follower 46 is carried at the end of link 33, preferably a roller as shown, which is engaged by a continuously rotating cam 50 having a plurality of lobes or dwells A, B, C, D, with fairly sharp drops therebetween, commensurate with proper camming drive on roller 46.

The lobes or dwells A, B, C, D of the cam effect rocking of the plate 22 so that there are a plurality of stationary or dwell :positions of the beam juncture on lines A, B, C, D (FIG. 3), as shown in consecutive geometric sequence, although the sequence of movement is not in geometric sequence, as will be explained. The position of the plate 22 in rocking about the axis of shaft 25 is indicated by the dash lines at the corner thereof (FIG. 1), likewise denoted A, B, C, D to conform with identification of the cam lobes and the beam dwell positions.

The dwell at each such position is for an arbitrary period of about one second and the cam layout is such that the motion of center line M follows in the geometric non-sequential order, from position to position, A-C-B DA-, etc., (FIG. 3), as indicated by the arcuate arrows IIIIIIIV, etc., in repetitive cycle.

The time consumed in. the to and fro passing from position to position is very short, relatively, being of the 1 order of a tenth of a second. Accordingly, the colors of the beam are seen as stationary and the motion time is of no consequence.

It will, of course, be understood that the channel depicted in dash lines on FIG. 3 is a predetermined deep water passage-way through which boats must navigate in order to avoid shallows, sandbars, etc., which may exist on each side of the channel. Thus, while a navigator is in the channel, he is safe, and the signals visible to him apprise him as to his relative position with respect to the width of the channel. Accordingly, he is guided in a manner to be described below along the course line K in mid-channel position and he is aided in finding and in following the course line by means of the relative time periods in which he sees alternating red and green signals, i.e., color portions of the composite beam, as they sweep back and forth across the course line.

The course line K, as shown in FIG. 3, is fixed and extends from the oscillatory axis while the dwell position lines A-B-C-D are the locations of the center line M in the order ACB-D as line M sweeps the channel.

The design of the lights is such that the beams will angularly diverge to a degree sufficient to give full radiation of their respective colors from center line M beyond the channel sides. For example, as seen in FIG. 3, the red beam would have an angular coverage from the origin 0 of the angle between lines K and L while the green beam would give the angular coverage between lines K and N. The point of origin 0 may be assumed to be the location of the two lights on the oscillatory platform, as seen from an operating distance, and the arcuate arrows will be understood to depict the direction and extent of motion of center line M of FIG. 3 in moving to and from the several dwell positions ABCD.

Bearing in mind that owing to the layout of the cam 50, the center line M moves non-sequentially between dwell positions in the order ACBD and remains in said positions for one second, a navigator at point Y in the channel (FIG. 3) would see a continuous red light, as illustrated in the chart of FIG. 4, for the navigator position on the ordinate, designated AL. This is due to the fact that for every dwell position of the lights only the red beam is visible above the line A, since the greatest clockwise rotation of the center line M is only up to position line A and all light clockwise of the line A is always red. Accordingly, the navigator at point Y knows he is off an accurate center course and will, therefore, seek the center course in the manner described below, as would a navigator at the point X (actually outside the channel) who would see only a continuous green beam, since the maximum counter-clockwise sweep of the center line would always maintain the green beam visible toward X, as indicated by the bar in FIG. 4, designated DN. If, however, the navigator is in the zone between A and B, say at the point Z, he will see a series of alternating color signals wherein the red signal lasts three seconds and the green signal lasts one second, respectively, as indicated in the bar designated A-B of FIG. 4. This is due to the particular sequence of oscillation of the lights relative the course line K. Thus, the navigator at Z (blelow line A) sees the green signal for one second when the center line M coincides with line A; when the line M goes to C (arrow I) for another dwell, the navigator sees the red signal, for one second, then line M goes to line B (arrow II) and the navigator sees the red signal for a second second, and finally, the line M goes to D (arrow III) and the red signal is seen for a third second. Subsequently, the center line M sweeps back to A (arrow IV) and the sequence is thus continually repeated.

In a similar manner, a navigator in zone C-D would see three seconds of green alternating with one second of red, as indicated on FIG. 4 by the bar CD.

Accordingly, a navigator, interpreting the time ratio of signals, red versus green, would know where he is in the channel and steer in the correct direction toward course line K. When he is on line K, he would see equal time interval signals, one second red, one second green alternating, as illustrated on FIG. 4 for the bar B-C, On Course. This follows from the symmetry of the dwell positions with respect to the course line; and observing the movements I-ll-III-IV of the juncture line it will be noted that the red and green beams alternate on line K (or anywhere in the zone lB-C) since each motion of the center line M crosses the course line K.

It will be appreciated that although the illustration of the invention shows integrally moving lights, the invention is not thus restricted. For example, individual lights independently movable in synchronization could be used, either pivotally with their reflectors or with lamps movable relative to fixed reflectors so as to achieve the swinging of the beams. The crux of the invention is the identification of a course line by adjacency of two signal beams of differing color moving in unison to effect a difference in the relative lengths of time a navigator sees each color, depending on his position in a channel as effected by predetermined dwell positions of the beams. Further, although the ideal beam condition is that there be an infinitely thin separation between the beams, as seen by a navigator, such ideal is impossible of attainment and some light blending or overlap will occur. Accordingly, the invention is not restricted to a composite beam of only two colors, and none other, but to the concept of providing a system where colors will alternate to the eye of a navigator in respective time duration so as to apprize him of his position and aid him in finding the prescribed course line. As a practical matter, if a navigator is close to or directly on a dwell position line A, B, C, D looking towards the lights, he is bound to see a blend of the beam colors which will appear as a white or yellow signal of one second duration. However, this may be disregarded, since he likewise sees the red and green signals of differing time duration to apprize him of his position, such red and green signals being the useful component of any composite signal which he may receive and which may comprise a blend.

Referring to FIG. 5, a two dwell position system having center line M sweeping back and forth to dwell positions B and C, is shown. The angle of radiation for red is between lines M and L: for green, between M and N. In this simplified system a two lobe equal rise cam could be used for about one sec-0nd dwell at B and C. Likewise, a four lobe cam, of equal rise for all lobes, rotating at half the sweep of a two lobe cam could also be used. In any event, the signals. seen by a mariner would be continuous red when he is at a point P, and continuous green at a point Q. Between B and C he would see the equal time alternations of red and green.

Having thus described our invention, we are aware that various changes may be made without departing from the spirit thereof and, therefore, do not seek to be limited to the precise illustrations herein given, except as set forth in the appended claims.

We claim:

1. In a device of the class described, a pair of light sources of differing color effecting closely adjacent beams, means for oscillating said light sources in unison with each other within a predetermined angle, and means for effecting in the course of oscillation a plurality of dwell periods at angularly distributed positions wherein said periods are substantially greater than the time consumed in passing from position to position, and wherein said positions are on both sides of a plane intermediate said light beams.

2. In a device as set forth in claim 1, a support means, said light sources being mounted on said support means and integral therewith.

3. In a device as set forth in claim 1, a support means, said light sources being mounted on said support means and integral therewith, a mechanical linkage means for oscillating said support means and comprising a cam having dwells for effecting said dwell periods.

4. In a device as set forth in claim 1, said light sources being angularly juxtaposed to each other to minimize blending of said beams.

5. In a device as set forth in claim 4, including a mask disposed intermediate said light sources and oscillatable therewith to substantially block blending of the two colors of said sources and to effect flat edges of the adjoining sides of said beams.

6. In a device as set forth in claim 1, including means disposed to minimize blending of the light from said light sources.

7. In a device of the class described, a pair of light sources, and means for moving said light sources whereby the beams thereof oscillate in unison, said beams being of different color and disposed adjacent each other and of sufficient expanse so as to radiate portions of respective color on each side at all times of a fixed line passing between said light sources, said means for moving said light sources comprising elements for effecting a predetermined dwell time of said beams at a plurality of dwell positions on each side of said fixed line during oscillation.

8. In a device as set forth in claim 7, there being a plurality of said dwell positions on each side of said fixed line comprising four such dwell positions, the movement of said beams being in in the position order A-C-B, starting at A, where the location of said dwell positions is in the order ABCD, positions A and B being one side of said course line and positions C and D on the other side, the time during which said beams remain at each dwell position being substantially greater than the time during which they are moving.

9. In a device as set forth in claim 7, said elements effecting said beam oscillation to and fro between dwell positions in a predetermined order so that each movement thereof crosses said fixed line.

10. In a device as set forth in claim 7, said elements comprising a rotary cam and a follower, link means intermediate said follower, and a support means, means biasing said link means to swing said support means in one direction, and lobes on said cam having predetermined dwell for effecting swing of said support means in the opposite direction, wherein said lobes predetermine the dwell time of said beams in said dwell positions, said light sources being integrally fixed on said support means.

11. In a device of the class described, means for effecting a composite light beam comprising different color portions, means for moving said composite beam repetitiously to a plurality of dwell positions on each side of a devised course line to be followed in a channel, means whereby at least part of a beam color portion is at all times visible on a respective side of said course line, and means whereby said motion of said composite beam is reversed in leaving each dwell position and wherein said motions vary predeterminedly in extent between dwell positions.

12. In a device of the class described, means for effecting a composite light beam comprising different color portions, means for moving said composite beam repetitiously to a plurality of dwell positions one each side of a devised course line to be followed in a channel, means whereby at least part of a beam color portion is at all times visible on a respective side of said course line, and means whereby said motion of said composite beam is reversed in leaving each dwell position and wherein said motions vary predeterminedly in extent between dwell positions, said different color portions being closely adjacent, and means providing for at least part of each beam color portion crossing said course line in each motion between dwell positions.

13. A range light for determining a predetermined course line to be followed, comprising means for effecting a pair of adjacent light beams of differing color, means for moving said pair synchronously with respect to said I course line, means for effecting such movement so that said beams move back and forth across said course line between predetermined positions on each side of said course line, means whereby said beams are of a width such that each beam has a portion thereof on each side of said course line at all times.

14. A range light as set forth in claim 13, and means for effecting reversal of movement of said beams at a position on each side of said course line, said positions being equidistant from said course line.

15. A range light as set forth in claim 13, and means whereby said beams reverse their direction of movement at each of two positions on each side of said course line, corresponding positions on each side of said course line being equidistant from said course line.

16. A range light as set forth in claim 13, and means whereby said beams reverse direction of movement at two positions on each side of said course line, said positions being an outer position on each side of said course line and an inner position on each side of said course line, said beams having-a motion cycle from an initial outer position on one side of said course line to an inner position on other side of said course line, thence to an inner position on said one side of said course line, thence to an outer position on the other side of said course line, thence to said initial outer position on said one side of said course line.

17. In a range light as set forth in claim 16, including means for effecting a dwell at each of said movement reversing positions.

18. A method of guiding a navigator in a channel which comprises moving a pair of light beams of differing colors back and forth across said channel so that said beams cross a predetermined course line with each movement, While controlling the movement so that a portion of each beam is at all times on a respective side of said course line, and reversing the movements at each of two positions on each side of said course line in a cycle such that reversal occurs at an outer position at one side of said course line, thence at an inner position on the other side of said course line, thence at an inner position at said one side of said course line, thence at an outer position at said other side of the said course line returning to said first mentioned outer position at said one side of said course line.

19. A system for identifying a predetermined line of direction comprising means for effecting a pair of adjacent light beams of differing color, means for moving said pair synchronously with respect to said predetermined line of direction, means for effecting such movement so that said beams move back and forth across said line of direction between predetermined positions on each side thereof.

20. A system as set forth in claim 19 and means Whereby said beams sweep said line of direction periodically at substantially equal time intervals.

References Cited by the Examiner UNITED STATES PATENTS 2,342,202 2/ 1944 Kennelly 34()49 2,595,253 5/1952 Heehler et al. 34049 NEIL C. READ, Primary Examiner.

A. H. WARING, Assistant Examiner.

Claims (1)

19. A SYSTEM FOR IDENTIFYING A PREDETERMINED LINE OF DIRECTION COMPRISING MEANS FOR EFFECTING A PAIR OF ADJACENT LIGHT BEAMS OF DIFFERING COLOR, MEANS FOR MOVING SAID PAIR SYNCHRONOUSLY WITH RESPECT TO SAID PREDETERMINED LINE OF DIRECTION, MEANS FOR EFFECTING

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