US 2531461 A
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R. C. PETRY MEANS FOR LINING RAILROAD CURVES Nov. 28, 1950 3 Sheets-Sheet 1 Filed March 29, 1946 N 29.50pm
Nov. 28, 1950 R. c. PETRY 2,531,461
MEANS FOR LINING RAILROAD CURVES Filed March 29, 1946 3 Sheets-Sheet 2 Nov. 28, 1950 c, PETRY MEANS FOR LINING RAILROAD CURVES 3 Sheets-Sheet 5 Filed March 29, 1946 Patented Nov. 28, 1950 MEANS FOR LINING RAILROAD CURVES Ray C. Petry, Westside, Iowa, assignor of onehalf to Edward L. Whiteing, Westside, Iowa Application March 29, 1946, Serial No. 658,357
1 Claim. 1
My invention relates to devices for the periodi, cal lining or correcting of railroad track on curves, with special reference to correction by workers unskilled in the art of surveying.
A typical railroad curve has a central portion conforming to a true circle and two easement ap-v proaches to the central portion both of which are spiral in character. The central circular POI..- tion is often termed the full elevation curve since on the outer rails the spiral approaches of the curve are banked progressively to a maximum, which maximum is maintained throughout the central circular portion.
Because of forces engendered by traffic, and because roadbeds tend to settle and are affected by weather, the rails of a railroad curve shift in the course of service to develop localized increases in curvature known as sharps and localized decreases in curvature known as flats. These deviations cause rough train travel and, of course, may become hazards if neglected. It is necessary, therefore, for section crews to correct or line the rails on curves periodically. The required correction may be accurately laid out with the help of; skilled engineers, but it is highly desirable to provide a method and means for those unskilled in the surveying art, so that section foremen can line curves without technical assistance.
To this end various procedures have been de- 5 veloped wherein a length of string is used to ascertain and correct the configuration of a rail? road curve. A series of six articles by Charles H. Bartlett in Railway Engineering 82 Maintenance, January to July, 1928, entitled The String Lining of Curves Made Easy, explains such a procedure in detail. In string lining, spaced stations are marked out along the track usually at distances of not less than thirty feet, and the ordinate or offset at each station is measured by employing a ruler and a piece of string. The ordinate or offset at a given station is the distance from the rail to the chord defined by the two adjacent stations, the chord being rep-. resented by the piece of string stretched taut between the two adjacent stations.
A typical string lining procedure includes the following steps, among others. The existing ordi-. nates are both plotted and totaled. A list of trial ordinates or tentative ordinates is drawn up on the basis of the average ordinate for the full elevation curve and on the basis of a formula of pro: gressive decrease of the ordinate on the spirals of the curve. This list Of tentative ordinates is increased or decreased as necessary to reach the same total as the existing ordinates. The next stepis to compute the accumulated effect of the trial or tentative ordinates by beginning at one end of the list and carrying out calculations from station to station to the end of the list. Invari ably this computation reveals a substantial ordinate for the last station where the end of the spiral joins the straight track, and since no ordinate 0. offset whatsoever is permissible at the end of the curve it is necessary to make some compensating changes in the trial ordinates. In making the compensating changes it is borne in mind that whenever they ordinate at one station is increased by a given amount the ordinates at the adjacent stations are decreased by one-half t a amo and vice. er a- Whe he comp nsating chan es re mad it is a ain n ary to compute through the lis of stations to be sure that the final ordinate is reduced to zero and also to reveal Whether or not any of the revised ordinates is of excessive magnitude. Usually some of the ordinates are found to be excessive o t at turther revision and further omputation are required.
The above described procedure involves considerable paper work and complicated calculations. The method is characterized by a certain amount of trial and error. Since different comna ns of ordinates may be han ed to red c the ordinate at an end station to Zero or to 001'? ot. an exc s v or i ate at y p n i h curve, personal judgment is exercised and twodiflerent competent operators may arrive at two different iinal curve configurations.
One o ject of my n ention i t imp y he pa r wo k i o d in l n g a c e. and o edu e the m a task. o a m n mum number. o steps requiring less skill than heretofore necessary. It is my pur os o p ov d apparatus for an exact procedure without any trial and error steps Th h man ua o s in mized since n bu den s plac d on the udgm nt o the operatQr. Broadly deSGlibed, the new procedure re! quires merely totaling the existing ordinates, are ivi at a cons an ord na for th cir ular tion of the c rve y imp d visi a d th n y simple multiplication derivin the final ordinate for the two spiral approaches.
Another br ob e t f my nv io a es to the mechanics of ascertaining the existing or must e taken to e h e s r ng ti h an o measure with accuracy the distance from the rail 3 to the stretched string, the measurement being taken perpendicular of the string. Obviously three workmen are required.
In my new procedure it is my purpose to dispense with the string and to rely on three simple sighting devices each of which will stay in a desired position relative to the rail without the continuous attention of a workman. Two men instead of three may measure the ordinates of a curve, if desired. In fact one man can employ the three sights to ascertain whether or not a recorded ordinate is correct. The use of sights instead or" string minimizes the chances for error.
More specific objects of the invention relate to the construction of the sighting means. these objects is to provide a sighting means that will take a predetermined position relative to the rail, preferably but not necessarily by directly engaging the rail. Another of these objects is to provide a sighting means that may be readily adjusted relative to the rail in accord with various ordinates at the various stations and will be provided with scale means to indicate the magnitude of such ordinates. A further object inthe preferred practice of the invention is to provide a sighting means that may be readily leveled.
Further objects and advantages of my invention will be apparent from the following description taken with the accompanying drawings.
In the drawings, which are to be regarded as merely illustrative:
Fig. 1 is a diagram of a curve divided by stations into sections, the diagram showing the existing ordinates at the various stations prior to correcting the curve configuration;
Fig. 2 is a similar diagram with the desired ordinates for the corrected curve noted thereon;
Fig. 3 is a diagram indicating how an ordinate at a station is ascertained;
Fig. 4 is a diagram indicating how the three sighting means of the present invention are employed in lining a curve;
Fig. 5 is a perspective View of the first of the three sighting means employed in practicing the invention;
Fig. 6 is a bottom view of the same sighting means;
Fig. 7 is a sectional view taken along the line 'I-! of Fig. 8; and
Fig. 8 is a perspective view showing the constraight track at each end of the curve is accurately lined as a preliminary step, thereby accurately positioning both ends of the curve in preparation for the lining procedure. These points at the end of the curve where th straight tracks or tangents meet the spiral portions of the curve are indicated T. S. in Fig. 1.
The first step in the lining procedure proper is to divide each of the spiral portions of the track into eleven equal sections by marking off thereon ten equally spaced stations numbered from 1 to 10, beginning at the T. S, end of the spiral. In practice this is accomplished by ascertaining the points where the full elevation portion of the outer rail begins and dividing into eleven equal parts the outer rail between that point and the corresponding T. S. These points of curvature at the two ends of the full elevation portion of the rail, i. e., at the ends of the intermediate truly circular portion of the rail, are designated P. C. in Figs. 1 and 2. After the spirals are thus One of 7;-
4 divided into sections the central full elevation portion of the curve between the two points P. C. is divided by stations into equal sections of the same length, or substantiall the same length as the sections in the spirals, the stations being numbered consecutively as indicated in Fig. 1. In Fig. 1 there are seven stations between the two points P. C. If, for example, the sections on the spirals are approximately 10 feet long and the full elevation of the curve is 76 feet long, the full elevation portion will be divided by seven stations into eight sections of approximately the same length, i. e., 9 /2 feet long.
After all the stations have been measured and marked the existing ordinates 0r offsets for all the stations are obtained by the measuring procedure indicated diagrammatically in Fig, 3. This figure shows how the offset or ordinate for station B may be obtained by locating a chord defined by the adjacent stations A and C and measuring the distance from the rail to the chord at station B. The ordinate or ofiset for station B is the distance 0 in Fig. 3.
This distance or ordinate 0 may be expressed in any suitable units, such as tenths of an inch or eighths of an inch. While the ordinate 0 may be ascertained by simply measuring with a ruler the distance from the rail at B to a piece of string stretched tightly between A and C, a feature of the preferred practice of my invention is the employment of special sighting means that avoids the use of string, as will be later explained.
While it is not strictly necessary to tabulate the data obtained by or employed in the various steps of my method, it is helpful to tabulate the data, and the following table is an example of what tabulations may be employed. Reference will be made to the various columns in the table in the further explanation of my invention.
Table I Difference FAlStll'lE Desired Stations v r between Ordinates Oidmatcs ordinates 12 12. 6 O. 6 8 10.8 2. 8 4 9.0 5. 0 2 7. 2 5. 2 i 5. 4 -l. 4 2 3. G l. 6 l 1.8 0. 8 0 0 After all of the existing ordinates are listed as shown in Table I the column is added, in this instance the total being 340. The ordinates are added algebraically since in some situations negative ordinates representing reverse curvature may be involved.
After the total of existing ordinates is obtained, I derive What I call a constant offset or constant hiinete $91 ap icati n to th ful eleva on p9 tion of the track, This constant is derived by dividing the total of the ordinates, i. e., 340, by the number of stations in the full elevation of the curve together with the number of stations n ne o th ra o s o the cu ve, I h pr s t am le t e a seve s at on ween t wo points and t n stations in. one of the spiral portions, so 340 is divided by 17 to give a constant ordinate of 20, This figure is placed in the above table as a desired ordinate for the stations I to 11 in the full elevaGiQn portion of he ar e,
The desired ordinate for each station on each of the two spiral portions of the curve is the constant ordinate times the factor .09 times the numerical order of the station in the spiral. Thus, the ten desired ordinates for the ten stations in a spiral portion of the present curve are calculated as follows:
Station I, 20 .09 1=i.8 Station 2, 20 .99 2=u.6 Station 3, 20 .09 3=5.4 Station 4, 20 Q9 4=7.2 Station 5, 20 .09 5 =9.0 Station 8, 20 .09 6=l0.8 Station I, 20 .09 7=12L6 Station 8, 20 .09 8=14.4; Station 9, 20 -.09 9=l6.2 Station It], 20 .09 l0=18.0
These desired ordinates are posted in the foregoing Table I.
In the course of my procedure the differences between the existing ordinates and the desired correctly lined station is employed at each step.
Thus the first lining step is carried out at station I on one of the spirals, and the adjacent correctly aligned station 0 at the adjacent point T. S. is used as a base or reference point. A second reference point is at the other adjacent stafish on the other side of station via: station 2, and is the point, usually an imaginary point, at which station 2 will lie on the corrected curve. The tabulation of differences between the existing ordinates and the desired ordinates becomes useful here since the corrected or final position for each station will be offset from the uncorrected rail by the distance shown in the last column of Table I. Thus Table I shows the difference in ordinates at station 2 to be +2.4, and a point at a distance 2.4 from the uncorrected rail at station 2 will be the final or corrected location of the station 2.
In lining or correcting the track at station I a chord or straight line from the corrected station I! to the point offset by the distance 24 from the uncorrected track at station 2 is established, and the track at station I is shifted or thrown to a new location at the desired ordinate with reference to the straight line or chord. In this instance. the track at station I is shifted to a III ne essary, but employin my data in such man ner is cumbersome. In the preferred practice. of my invention I employ suitable sighting means that makes the use of string unnecessary and avoids the necessity of driving any stakes. what.- soever. Preferably there are three sighting means constructed in the manner indicated in the drawings. The first of the three sighting means is constructed as shown in Figs. 5 and 6, and. each of the other two sighting means is con: structed as shown in Figs. 7 and 8.
In Figs. 5 and 6, showing the first of the three sighting means, a base Iii, in the form of a block of hard wood, is provided with an upper face plate II anchored by suitable screws l2. A suitable sight or sighting stake I3 is mounted on the base ill; and may consist of a simple metal sighting rod formed with a point I5. In the construction shown a suitable nut I6 is welded or brazed to the base plate II, and the sighting element I3 is threaded into the nut. When the device is not in use the sighting element may be removed for compactness.
It is essential that the base I0 for the sighting element be adapted for predetermined positions ing relative to a rail, it being contemplated that a portion of the base will be placed in a given position relative to a vertical planev at the rail. In the preferred practice of my invention the base I9 is adapted for mechanical engagement with the rail to insure the desired predetermined relative positioning of the base. Any suitable means be employed for engaging the base with the rail, but I prefer an arrangement in which a rigid flange or jaw fixed relative to the base I!) abuts one side face of the rail, and a second movable or flexible flange or jaw abuts the second face of the rail.
In the present construction a fixed flange or jaw I1 is provided by mounting an angular plate I8 on the under side of the base I0 by suitable screws 20, the angular plate being relatively rigid and extending precisely perpendicular to the base I I], It is contemplated that all measurements ofordinates will be taken from the side of the rail contacted by the fixed flange I1, and therefore the axis of the sighting rod I3 will lie inthe plane of the fixed flange II.
The required second flange or jaw ZI is provided by a flexible plate 22 that is secured onthe end of the base by suitable screws 23'. Preferably the flexible plate. 22 is bent inward along the line- 25 so that the flange 21 must be sprung outward to engage a rail. The inward biasing of the second flange 21 in this manner insuressuch gripping pressure on the rail as to maintain the base It} in any position of adjustment. It is contemplated that when the base It is mounted on a rail and adjusted to. place the sighting rod I3 in a vertical plane the base will maintain such position without, further attention.
lf'referably a suitable gravity-responsive means provided for guidance in an accurate positions. ing of the sighting rod IS in a vertical plane at the side of the rail represented by the fixed flange I'l'. In the present construction the face plate II isformed with a slot 26 in which is. installed a spirit level 21', as shown in Fig. 5..
Each of the second; and third sighting means in the combination of three sighting means is of the same general construction as just described, but both have sighting rods that are adjustable, with respect to offset from the rail. The preferred construction shown in Figs. 7 and 8 includes a base 28 in the form of a wooden block on which a suitable face plate 30 is mounted by suitable screws 3 I. In this instance the face plate 39 forms a wide longitudinal groove or channel 32 of dovetail cross-sectional configuration in which is mounted a dovetail slide 33. A sighting rod 35 of pointed configuration is screw-threaded into a suitable boss 36 at one end of the slide 33. For releasably fixing the longitudinally position of the slide 33 the slide may be formed with a longitudinal slot 31 through which extends a suitable fixed screw 38 carrying a washer 4D and a wing nut 4|. The nut 4| may be loosened temporarily to permit shifting the sighting rod 35 as desired.
On the slide 33 in the plane of the axis of the sighting rod 35 is an index mark 42 for use with respect to a longitudinal scale 43 on the face plate 30, the scale being graduated in units of distance and reading in both directions from a zero point shown at 45. The face plate also has a longitudinal slot 46 in which is mounted a spirit level 41 to indicate when the sightin rod 35 is in a vertical plane.
The sighting means in Figs. 7 and 8 is adapted for engagement with a rail by means of a rigid fixed flange or jaw 48 and a cooperating flexible flange or jaw 49 in the manner heretofore described. It is to be noted that the zero point on the scale 43 is in the plane of the inner face of the fixed flange 48.
To carry out the procedure of ascertaining the existing ordinates at the various stations of the curve the three sights are placed at three successive stations to reveal the ordinate at the intermediate station. Fig. 3, the first sighting means (shown in Fig. 5) is placed at station A and leveled to make its sighting rod vertical. The second sighting means, which is adjustable, is placed at station B, and
the third sighting means, which is also adjustable, is placed at station 0. The sighting rod of the third sighting means is set at zero to place it in vertical alignment with the edge or side face of the rail. When so adjusted the third sighting means serves in the same manner as the first non-adjustable sighting means. With one man at station B manipulating the adjustable slide of the second sighting means, a second man at either station A or C sights along the three sighting rods to guide the first man in placing the second sighting rod in line with the other two rods. When the three sighting rods are in line the index mark 42 of the second sighting rod at station B will be at a point on the corresponding scale 43 that represents the existing ordinate at station E.
The manner in which the three sighting rods may be employed in the final operation of progressively lining the curve to conform to the desired ordinates may be understood by referring to Fig. 4. This figure shows in solid lines the existing or uncorrected configuration of the rail R at the stations 0, I and 2 at the left end of the curve, and shows in dotted lines the desired configuration of the rail; that is to say, the configuration conforming to the desired ordinates in Table I. The first of the three sighting means, indicated at S, is placed at station 0, which, as heretofore stated, is already corrected. The second of the three sighting means, indicated at'Sz, is placed at station I, the station now to be corrected, with the sighting rod 35 Referring to the diagram in z thereof positioned at the point 1.8 on its ordinate scale, since the desired ordinate at station I is 1.8. The third sighting means S3 is placed at station 2, with the sighting rod 35 at the point 2.4 on its ordinate scale, the value 2.4 being the difference between the existing ordinate 6.0 and the desired ordinate 3.6 as listed in Table I. It is to be noted that such adjustment of the third sighting means places the third sighting rod at the desired or corrected position for station 2. Thus Fig. 4 shows the dotted position of the rail passing through the third sighting rod.
When the three sighting means S, S2 and S: are positioned as described and as shown in Fig. 4, one man sights along the three sights and workmen throw or shift the rail in the region of station I until the sighting rod 35 on the second sighting means S2 is carried by the rail into line with the other two sighting rods. When the three sighting rods are in line the rail at station I is at the position represented by the desired ordinates in Table I.
The three sighting means are now shifted to place sighting means S, at station I, sighting means S2 at station 2, and sighting means S3 at station 3. The procedure is repeated to throw the rail at station 2 to the correct position for the desired curvature. In this manner the track is progressively lined throughout the curve.
My description in detail of my preferred means for carrying out the procedure will suggest to those skilled in the art various changes and substitutions within the scope of my appended claim.
I claim as my invention:
A sighting device for aligning rail curves comprising a block having linear guide means and having rail-engaging flanges extending transversely to the longitudinal axis of said guide means and projecting downwardly therefrom for mounting the block on a rail, a slide mounted on said guide means for movement laterally of the rail along he longitudinal axis of the guide means, a guide post mounted on the slide, and a scale associated with the slide for indicating the position of the guide post laterally of the rail, said post having a range of movement which includes positions in which a vertical portion of the guide post is inside the gauge edge of the rail and at least to the center line thereof and also positions in which said vertical portion of the guide post is outside said gauge edge, whereby th sighting device may be used to establish with another such device a second reference point in the aligning of the rail.
RAY C. PETRY.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Germany Apr. 13, 1932