US3381626A

US3381626A - Track working assembly and control system

Info

Publication number: US3381626A
Application number: US537387A
Authority: US
Inventors: Russell J Fagan; James E Anderson; Bruce W Bradshaw; David G Strasser
Original assignee: JACKSON VIBRATORS Inc
Current assignee: JACKSON VIBRATORS Inc
Priority date: 1966-03-25
Filing date: 1966-03-25
Publication date: 1968-05-07
Anticipated expiration: 1985-05-07

Description

May 7, 1968 R. J. FAGAN ET L TRACK WORKING ASSEMBLY AND CONTROL SYSTEM Filed March 25, 1966 6 Sheets-Sheet l May 7, 1968 R. J. FAGAN ET AL 3,381,626

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May 7, 1968' R. J. FAGAN ET AL 3,381,626

TRACK WORKING ASSEMBLY AND CONTROL SYSTEM Filed March 25; 1966 6 Sheets-Sheet 5 a, Z M ug J 54: 4 +W. f WIAEJ ma May 7, 1968 J, FAGAN ET AL TRACK WORKING ASSEMBLY AND CONTROL SYSTEM 6 Sheets-Sheet 4 Filed March 25, 1966 Q I Y R. J. FAGAN ET AL 6 Sheets-Sheet 5 W2 em NA M M mg ew a W a 0 xw w wm m v.

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May 7, 1968 Filed March 25, 1966 6 Sheets-Sheet 6 R. J. FAGAN ET AL TRACK WORKING ASSEMBLY AND CONTROL SYSTEM May 7, 1968 Filed March 25, i966 T'"-----1 l l l 1 I AYI United States Patent 3,381,626 TRACK WORKING ASSEMBLY AND CONTROL SYSTEM Russell J. Fagan, James E. Anderson, Bruce W. Bradshaw,

and David G. Strasser, Ludington, Mich., assignors to Jackson Vibrators, Inc., Ludington, Micln, a corporation of Illinois Filed Mar. 25, 1966, Ser. No. 537,387 16 Claims. (Cl. 1047) This invention relates to railroad track maintenance apparatus and more particularly concerns an assembly for correcting and resetting both track surface and alinement.

Railroad track surfacing is the vertical smoothing of the track, usually accomplished by slightly raising the track and retamping the ties, with the lower clips or bends in the track being raised more than the higher portions so that the result is a levelling or smoothing of the track surface. Track alining, more commonly called lining," is the sideto-side shifting of the track to produce straight or tangent track, and smooth curves of a desired arc. As surfacing tends to disturb alinement, and vice versa, it is obviously desirable to perform both functions at the same time.

Since track is normally jacked up for both surfacing and lining operations, simultaneously performing both tasks theoretically appears readily possible. However, what has remained difficult is control of the track repositioning operation, i.e., moving the track only enough to effect the desired corrections.

Track position has been determined either by optical or mechanical means. Optical surfacing or alinement has reference to line of sight determinations of track position, often with the aid of sight blocks or spot boards which establish at least three reference points on the track which can be optically alined. More complex optical arrangements and proposals have included telescopes, lights, photoelectric cells and even television cameras with remote viewing screens. In such optical systems the track itself is the reference line which is lifted or transversely shifted until a line of sight or light path paralleling the track shows that the track has been properly adjusted.

Mechanical arrangements for surfacing and lining track involve extending some physical thing along the track, such as a long beam or a tensioned wire or cord, and adjusting the track to the positive reference. A long railroad car has itself served as a positive reference member from which track deviation has been measured and corrected. A- cord of standard length has also, been long used for lining curves and, more recently, tensioned wires have been widely employed for controlling both track lining and surfacing.

When attempting to simultaneously control both surfacing and lining, prior attempts to use either optical or mechanical systems have left much to be desired. Mechanical reference lines are subject to structural sag, environmental effects such as wind vibration and thermal changes, and the limitation of being a fixed length. Moreover, the positive reference members themselves tend to crowd the working area making proper manipulation and re-establishment of the track more difficult. The optical principle has been difficult to automate, that is, to duplicate the eyes ability to determine how far the track is out of line and the direction in which it should be moved. Optical systems also require clear lines of sight and known arrangements make it very difiicult to work around the tamper without interfering with the control system.

Accordingly, it is the primary aim of the invention to provide an improved track working assembly which simultaneously surfaces and lines railroad track under optical, i.e., line of sight, control so as to obtain flexibility and convenience in operation.

3,381,625 Patented May 7, 1968 More particularly, it is an object of the invention to provide a track working control system in which the rate of track positioning is proportional to the amount of deviation, in either direction along the planes of adjustmerit, from an optically determined proper position.

Another object is to provide an assembly and control system of the above character which permits accurate surfacing and lining while leaving the track positioning and tamping area free for workmen assisting the operation.

It is also an object to provide an assembly as described above which allows lining, as well as surfacing, toward a fixed point along the track well in front of the positioning and tamping machine. This allows the track to be lined to a desired point, and the ability to work at varying distances from the reference point is particularly useful in lining stretches of straight or tangent track.

A further object is to provide an assembly and control system as characterized above which is capable of rapid, automatic and accurate work.

Other objects and advantages of the invention will become apparent upon reading the following description and upon reference to the attached drawings, in which:

FIGURE 1 is a partially diagrammatic perspective of a track working assembly embodying the present invention;

FIG. 2 is a digrammatic perspective illustrating some operating principles of the assemble shown in FIG. 1;

FIG. 3 is an enlarged fragmentary front elevation of the larger machine appearing in FIG. 1;

FIG. 4 is a fragmentary section taken approximately along the line 44 in FIG. 3;

FIG. 5 is an enlarged fragmentary rear elevation of a portion of the structure shown in FIG. 1;

FIG. 6 is a fragmentary section, somewhat enlarged, taken approximately on the line 66 in FIG. 5;

FIG. 7 is an enlarged fragmentary rear elevation of another portion of the structure shown in FIG. 1;

FIG. 8 is a fragmentary side elevation of the structure shown in FIG. 7;

FIG. 9 is a slightly enlarged elevation taken approximately along the line 9-9 in FIG. 8;

FIGS. 10 and 11 are enlarged fragmentary elevations of the smaller machine shown in FIG. 1; and

FIG. 12 is a schematic wiring and hydraulic diagram showing a portion of the control circuit utilized in the FIG. 1 assembly.

While the invention will be described in connection with a preferred embodiment, it will be understood that we do not intend to limit the invention to that embodiment. On the contrary, we intend to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

The general tamper assembly Turning first to FIG. 1, there is shown a track working assembly embodying the invention and including a tamper 10 and a light carriage 11 operating on the rails 12 of a length of railroad track. The tamper 10 is preferably of the on-track, self-propelled, production type, including a frame 13 supported on flanged track wheels 14 and car rying an operators cab 15 and a plurality of tamping units 16 mounted on vertically movable crossheads 17, only one of which is shown.

In order to position the track, the tamper carries rail jacks 21 and rail clamps 22 of which only the right-hand set is illustrated. The clamps 22 are adapted to grip the rails 12 and the jacks 21 include feet 23 which can be planted solidly in the ballast outboard of the ties supporting the rails. A plurality of hydraulic actuators, discussed in detail below, are coupled to the jacks 21 for causing relative movement both vertically and horizontally between the jack feet 23 and the rail clamps 22, thus permitting the track to be both raised and shifted from side to side.

The light carriage 11 is arranged for movement on the rails 12 independently of the tamper 10, and includes a frame 25 supporting a power plant 26 which both propels the carriage 25 and energizes a plurality of lights disposed in light sets 27 and 28. Preferably, the power plant 26 has a forward and reverse clutch in the carriage propelling driving train that can be remotely controlled either by a cord or line extended from the tamper or by a radio signal actuated relay which permits a small radio transmitter to control movements of the carriage 11. The use of a line extended between the tamper and the light carriage is useful to keep a relatively constant spacing between the tamper and the carriage, and the radio control is particularly useful in running the light carriage 11 out to a suitable point toward which track surfacing and lining operations are desired to be directed.

In the illustrated construction, each of the light sets 27, 28 is arranged to cooperate with a respective one of the rails 12 with the sets being substantially identical. Construction of the light sets is discussed in greater detail below, and for present purposes it will be suflicient to note that each set includes lower lining lights 31, upper lining lights 32, and surfacing lights 33. The lining lights 31, 32 of each of the light sets are disposed one above the other and are alternately useable.

To read or sense the lights on the carriage 11, the tamper 10 carries pairs of sensors, each pair including a horizontal sensor 34 and a vertical sensor 35, mounted on a common frame 36 that is adapted to ride on the rails 12 independently of the tamper 10. Construction and mounting of the sensors is discussed in greater detail below, but for the present it will be noted that each of the

sensors

34, 35 is similarly constructed with the horizontal sensors 34 functioning for lining the track and the vertical sensors 35 functioning for surfacing the track. The sensors are capable of generating an electrical output signal when struck by a light pattern, unless the pattern falls in a predetermined, neutral or null position on the sensor. In the preferred construction, the patterns utilized are single bands of light 38 and 39 (see FIG. 2) falling across the narrow dimension of the rectangular receiving faces of the

sensors

34, 35, respectively. The centers of the long dimension of the light-receiving sensor faces are the null positions of the sensors.

Cooperating with the lights on the carriage 11 and the

sensors

34, 35 are mast sets 40, only the right-hand set being illustrated in .FIG. 1, carried on the tamper 10 on a common frame 41 which rides independently of the tamper on the track rails 12. Construction and operation of the mask sets 40 are also covered in greater detail below but, for present purposes, it will be seen that the sets include a first mask defined by portions of an opaque, box-like plate 42 outlining a horizontal slot 43 and a second mask defined by other portions of the plate 42 outlining a pair of vertically alined slots 44 and 45.

General operating principles In the layout of railroad track, determinations of track alinement are referenced to one rail selected as the lining rail and determinations of the track surface are referenced to one rail selected as the grade rail. The grade and lining rails are not necessarily the same rail and, indeed, in track curves the inner and lower rail is normally the grade rail and the outer and superelevated rail is normally the lining rail. In the preferred operation of the disclosed track working assembly, the lights and sensors over the grade rail are used while the corresponding elements on the opposite side of the tamper 10 remain idle. The mask set 40 and the

sensors

34, 35 in use are then referenced latorally to the lining rail, whether or not it is also the grade rail.

In the drawings, it has been assumed that the left rail 12 in FIG. 1 is the grade rail, so that the surfacing light 33 in the light set 27, which occupies a predetermined, horizontal plane above the track, is illuminated to direct a beam of light toward the mask plate 42 and the sensors 34, at the left-hand side of the tamper 10. One of the lining lights 31, 32 in the set 27, which occupies a predetermined, vertical plane along the track, is also illuminated to direct a beam of light toward the mask plate 42 and the sensors on the left-hand side of the machine. In FIG. 2, the lower lining light 31 is shown illaminated.

Taking the FIG. 2 example, light from the surfacing light 33 passes through the horizontal slot 43 creating a flat, generally horizontal, beam that strikes the vertical sensor 35 to form the light band 39. Light from the lining light 31 passes through the vertical slots 44, 45 to create flat, generally vertical beams, the lower one of which strikes the horizontal sensor 34 to form the light band 38. In the illustrated arrangement, light from the upper lining light 32 causes a beam from the upper vertical slot 44 to strike the sensor 34 whereas light from the lower lining light 31 creates a beam through the lower slot 45 which strikes the sensor 34.

The null position of the sensor 35 occupies a predetermined or fixed plane above the track, and the null position of the sensor 34 occupies a predetermined or fixed plane along the track. It can thus be seen, in the FIG. 2 example, that when the light band 39 is at the null position of the vertical sensor 35, the horizontal planes of the surfacing light 33, the slot 43 and the null position of the sensor 35, all coincide. When the light band 38 is at the null position of the horizontal sensor 34, the vertical planes of the lining light 31, the vertical mask slot 45, and the null position of the horizontal sensor 34, all coincide.

In accordance with the invention, the horizontal lining sensors 34 are prevented from sensing light from the surfacing lights 33, the vertical surfacing sensors 35 are pre vented from sensing light from the lining lights 31, 32, and the

sensors

34, 35 are coupled to the jack actuators in an electrical-hydraulic circuit so that the track is lifted and simultaneously shifted from side-to-s-ide until the light patterns created by the mask set 40 on the side of the grade rail sensors reach the null positions of those sensors. Preferably, selective light sensing is obtained by mounting light polarizing filters over the lights and the sensors, with the filters over the lining lights and the horizontal sensors being rotated from the angle of the polarizing filters over the surfacing lights and the vertical sensors. Thus, the polarized light from the surfacing lights 33 does not pass through the transversely disposed polarizing filters in front of the sensors 34. Conversely, the light from the lining lights 31, 32 which is polarized in one plane cannot pass through the transversely disposed polarizing filters in front of the vereical sensors 35. Each sensor therefore sees or senses the lights which are intended for its particular function. Ambient non-polarized light is, of course, received by the sensors but, as explained below, this does not affect sensor operation.

When surfacing or smoothing track, the null position of the vertical sensor 35, the horizontal slot 43 and the surfacing light 33 are all mounted at one given height above the track. In effect, and again with reference to the FIG. 2 example, the sensor looks through the slot 43 until it sees its null position alined with the light 33, much in the manner of a track foreman looking over a sighting block or through a sighting telescope to line up a jack block with a spot board. The electrical-hydraulic circuit between the sensor and the jack actuators causes the track on which the mask set 40 rests to be moved vertically until the light band 39 falls in the null position of the sensor 34. When raising the track, the surfacing light 33 is further elevated the desired amount of the raise, in the same manner as a spot board is elevated to put in a track raise. For surfacing, therefore, the carriage 11 can be positioned along the track from high point to high point, or placed at a track position where track elevation must remain fixed, or else moved in step along with the tamper. In each case, the vertical position of the surfacing light 33 relative to the height of the slot 43 and the null position of the sensor determines how much the jacks 21 will raise the tracks, and thus the mask plate 42, to the alined position.

Similarly, when lining track, the sensor 34 looks through either the slot at the light 31, or the slot 44 at the light 32, and the electrical-hydraulic circuit between the sensor and the jack actuators causes the track on which the mask set 40 rests to be moved laterally until the light band 38 falls in the null position of the sensor 34.

As a feature of the invention, the lower lining lights 31 are mounted close to their respective rails 12 and the horizontal lining sensors 34 are mounted at the upper rear of the tamper 10. Thus, lateral tilting of the carriage 11, as when the track moves into a curve, has little effect on the vertical plane in which the lights 31 lie relative to the track. Also, this arrangement permits workmen to function in and around the front of the tamper 10 without blocking light from the lights 31 to the sensors 34. It is often necessary to throw ballast under and around ties being raised and laterally shifted, and opening up the area around the crossheads 17 of the tamper 10 allows this and other required manual tasks, to be done with no interference to the automatic control of the tamper.

As another feature of the invention, the upper lining lights 32 and the horizontal lining sensors 34 are mounted at approximately the same height above the track and in substantially the same vertical planes relative to the track. This permits accurate lining of straight, i.e. tangent, track with the tamper 10 and the light carriage 11 spaced varying distances along the track since, using the lights 32, the sensors 34 sight parallel to the grade rail. Thus, the tamper 10 can work right up to the carriage 11 when the latter is placed at a point where track position must remain constant. When the lower lining lights 33 are used, the sensors look down along a line not parallel to the grade rail and a variation in the tamper-light carriage spacing could move the mask plate 42 from the light path between the lights and the sensors. Thus, when the lower lining lights 31 are utilized it is desirable to maintain the light carriage 11 at an approximately constant distance in front of the tamper 10.

The rail jacks and clamps The jacks 21 and the rail clamps 22 positioned at each side of the tamper 10 are mounted on a common strongback or crossbeam (see FIGS. 3 and 4). In operation, the beam 50 is lowered on the tamper frame 13 until flanged wheels 51, mounted on the crossbeam and only one of which is shown, rid on the track rails 12. For transport, the beam 50 is lifted clear of the track by a pair of actuators 52, again only one being shown, which extend from lugs 53 on the tamper frame 13 to the upper portion of brackets 54 which are fixed to the crossbeam. The brackets 54, one at each end of the beam although only the right-hand bracket 54 is shown, carry rollers 55 which ride in slots 56 formed in the frame 13 of the tamper. This connection between the crossbeam'and the tamper frame allows the beam to float relative to the tamper with the flanged wheels 51 in contact with the track rails 12 when the jacks are in operation.

To prevent tilting when the actuators 52 are extended to raise the crossbeam 50 to transport position, arms 57 are fixed on the brackets 54 supporting rollers 58 which engage plates 59 on the front of the frame 13 so as to limit counterclockwise swinging of the crossbeam 50 about the axis defined by the rollers 55. Bumpers 60 are secured to the crossbeam to engage the front of the plates 59 so that the crossbeam assembly is moved along in front of the tamper during operation.

Each of the rail clamps 22 include opposed fingers 62 pivoted on a pin 63 that is mounted in bracket plates 64 which are rigidly fixed to the underside of the crossbeam 50. A pair of actuators 65 are anchored on the crossbeam 50 and extended to the upper ends of the fingers 62. C01- lapsing or shortening the actuators 64 opens the rail clamp fingers 62 whereas extending the actuator 65 causes the finger 62 to clamp beneath the head of the track rail 12 so as to lock the rail to the crossbeam 50. Preferably, bumpers 66 are mounted in the bracket plates 64 to cushion clamping movement of the fingers 62.

In carrying out the invention, the jack feet 23 are mounted for both vertical and transverse movement relative to the rail clamps 22. In the illustrated construction, the feet 23 are fixed at the bottom of square posts 70 which slidably extend up into square column 71, only the right-hand assembly being illustrated. Hydraulic actuators 72 are positioned within the posts 70 anchored between the posts and the columns 71 (see also FIG. 12). The columns 71 are mounted at the outer ends of a pair of I-beams 73 slidably fitted within the crossbeam 50. Pairs of rollers 74 are journalled on the crossbeam 50 in contact with the I-beams-73 so as to transfer jacking loads to the crossbeam while minimizing frictional resistance to transverse movement of the I-beams.

The jacks 21 are moved transversely by actuators 75 (see also FIG. 12) which extend between lugs 76 on the top of the crossbeam 50 and the columns 71. To establish an initial jacking position, a pair of microswitches 77 and 78 (also shown in FIG. 12) are mounted on an arm 79 secured to the crossbeam 50, and a cam 81 is formed on an arm 82 that is secured to the column 71. A similar arrangement is utilized for each of the jacks 21. As will be described in more detail below, the initial jack working position is established when the cam 81 is positioned between, and without actuating either of, the

microswitches

77, 78. For transport, the jack feet 23 are lifted by the actuators 72 and the columns 71 are pulled inwardly by the actuators 75 adjacent to the ends of the crossbeam 50.

The mask sets The box-like plates 42 of the mask sets 40 are defined by panels 91 and 92 (see FIGS. 5 and 6) stiffened by ribs 93. Collars 94 are secured to the bottoms of the plates 42 and are mounted on parallel rods 95 fixed on the top of a cross rail 96. The cross rail 96 is tiltably secured at each end by a bolt 97 to a fitting 98 which is slidably mounted on top of a side post 99 forming part of the frame 41. The frame 41 carries flanged wheels 101 which ride on the track rails 12. A screw 102 serves as an adjustable abutment stop for the fitting 9S and, since the opposite side mounting of the cross rail is identical, it can be seen that adjusting the screws 102 at each side of the frame 41 permits vertical adjustment and cross levelling of the rail 96, and hence of the mask sets 40, to their proper working positions.

To insure that the mask slots 44, 45 are held in proper lateral alinement with the underlying rail, pneumatic actuators 105 are mounted on the crossbeam 50 and connected by

links

106 and 107 to the frame 41. The links 106 are pivoted on the crossbeam 50 and the links 107 are pivoted between the links 106 and frame 41. Actuation of the actuator 105 illustrated in FIG. 5 swings the associated link 106 clockwise so as to push the frame 41 to the left until the flanged wheel 101 is stopped by the track rail. This tends to establish and fix the vertical relationship between the underlying rail and the mask slots 44, 45 above it. Actuation of the actuator 105 at the opposite side of the frame 41 moves the frame to the right and fixes the right-hand mask set 40 with respect to the rail on that side of the tamper. A pair of stops 109 on the frame 41, only one of which is shown in FIG. 4, engage the top of the crossbeam as the latter is raised so that the frame lifts with the crossbeam to a transport position clear of the track, and is lowered with the crossbeam onto the track rails for operation.

As a feature of the invention, the mask plates 42 are mounted for controlled lateral movement of the frame 41. In the preferred embodiment, the collars 94 are slidably fitted on the rods 95, and screws 110, rotatably mounted on the cross rail 96 parallel to the rods 95, are fitted respectively through nuts 111 secured to the plates 42. The screWS'110 are coupled to small reversible electric motors 112 which, when energized, rotate the screws so as to drive the nuts 111 and hence the mask plates 42 along the rods 95 in either direction depending upon the direction of the rotation of each motor 112. Scales 113 are mounted on the cross rail 96 and a pointer 114 is secured to each of the plates 42 in cooperative relation with the respective scale. The scales 113 for each of the mask sets are readily visible from the operators cab and the motors 112 are also controlled from the cab. Lateral movement of the mask sets is not only used to vertically aline the slots 44, with the rail selected as the grade rail, but the motors 112 and the scales 113 are also employed along with meters in the operators cab to prelog or plot track curves in a manner which'will be described in more detail below.

The light sensors The

light sensors

34, 35 are mounted in brackets anchored to the upper corners of the frame 36 (see FIGS. 7 and 8). For initial aiming, the sensors 34 are mounted on trunnions 121 and the sensors 35 are mounted on trunnions 122, the trunnions being rotatably held in the brackets 120. Locking screws 123 mounted in the brackets 120 can be loosened to permit pivoting and aiming of the

sensors

34, 35 and, when tightened, the screws 123 hold the sensors in adjusted positions.

The frame 36 carries track engaging flanged wheels 125 and, like the mask frame 41, pneumatic actuators 126 on the tamper frame 13 are coupled by

links

127 and 128 to the frame 36 so as to urge the frame to one side or the other and thus hold the selected sensor 34 in fixed relationship to the underlying rail selected as the lining rail.

To raise the frame 36 to a transport position clear of the track, hydraulic actuators 131 extend from the tamper frame 13 to each lower side of the frame 36. The frame is guided for vertical, and some horizontal, move ment between rollers 129 mounted in brackets 130 on the tamper frame 13. Energization of the actuators 131 lifts the frame 36 clear of the track for transport purposes and also lowers the frame until the wheels 125 engage the rails. Energization of one of the actuators 126 causes the frame 36 to be moved laterally until the adjacent flanged wheel is pressed against the selected grade rail, thus holding the overlying sensor 34 in a fixed positional relationship with the lining rail.

In carrying out the invention, the sensors include a plurality of closely arrayed photoelectric cells 135 aimed forwardly behind polarizing filters 136 and coupled in electrically balanced circuits (see also FIG. 12). In the preferred construction, the cells 135 are disposed in two adjacent lines, with the cells being staggered so that a light pattern across the narrow dimension of the sensor overlaps several cells (see FIG. 9). Shifting movement of the light band along the length of the cell array thus energizes the same total number of cells, but different cells are illuminated depending upon the light band position.

The preferred electrically balanced circuit couples the cells on each side of the sensor center or null position in parallel groups, and the two groups of cells in series (see particularly FIG. 12). A DC voltage source 137 is connected across the cells 135 through

load resistors

138 and 139. A pair of oppositely poled Zener diodes 140 connected to ground and at each end of the cell array establishes fixed plus and minus voltages at the opposite ends of the cell array. In use, all of the cells 135 receive some ambient light reflected by the sensor surroundings. Since the cells receive equal amounts of light, their resistances in the circuit are equal and the voltage drop is uniform across the cell array. A variable resistor 141 is interposed in the series connection between the cells on the opposite side of the null position so that the cell circuit can be exactly balanced to impose a zero voltage on a groundconnected signal resistor 142 when the cells are uniformly illuminated.

When a light band from the mask sets 40 strikes the sensor photocells 135, the resistance of the photocells hit by the light band changes. The preferred cells being of the photo-resistive type, if the light band 39 strikes only cells in the upper array of the sensor 35, for example, the resistance of the positive side of the balancing resistor 141 will greatly increase, causing a negative, with respect to ground, voltage signal to be imposed across the signal resistor 142. As the light band 39 moves down, some of the cells below the neutral or null position will be illuminated and fewer of the cells above the null position will remain illuminated. Therefore, the negative voltage signal becomes less until an equal number of Cells above and. below the null position receive light. At this point, the circuit is again in balance and the output signal is zero. If the band continues to move down, a positive voltage signal is imposed on the signal resistor 142. Preferably, the magnitude of the output signals from the sensor 35 is controlled by a variable resistor 143.

It will, of course, be understood that all of the

sensors

34, 35 are similar to the sensor 35 described above in connection with FIGS. 9 and 12.

The

sensors

34, 35 are, therefore, more than simply receivers noting the presence or absence of a light beam. They sense the position of a received beam and generate a signal of variable intensity indicating both the direction and amount of deviation of the beam from the center or null position of the sensor. The

sensors

34, 35 are also unaffected by ambient light which hits all of the cells since the sensors react only to a light pattern which creates an unbalance in the sensor circuit.

The light carriage The light sets 27, 28 on the light carriage 11 are mirror images of one another. The set 27 has its lights 31-33 mounted in upper and

lower housings

151 and 152, re spectively (see FIGS. 10 and 11). The lower housing 152 in which the light 31 is fixed is secured to the carriage frame 25. The housing 152 is pivoted at 153 and held at an adjustable, upwardly aimed angle by a threaded adjusting screw 154.

The upper housing 151 is fixed to the top of a twopiece mast 155. The lower portion of the mast is hollow and slidably receives the upper portion. Threads 156 are cut on the upper portion of the mast 155, and the threads 156 carrying a pair of nuts 157. The nuts 157 abut the top of the lower hollow portion of the mast and, by rotating the nuts, the upper housing 151 can be adjustably raised and lowered. The nuts 157 are jammed together when the desired adjusted position has been reached.

A pointer element 158 is secured near the bottom of the upper portion of the mast 155 and extended outwardly through a slot 159 in the lower portion of the mast. The pointer not only prevents relative rotation between the mast portions but also cooperates with a scale 160 to give a visual indication of the vertically adjusted position of the upper lamp housing 151. The scale is preferably calibrated in inches with a zero mark establishing the height of the surfacing light 33 at the operating heights of the slots 43 and the null positions of the sensors 35. Thus, the nuts 157 can be manipulated to raise the light 33 a number of inches shown on the scale 160 in order to put into the surfacing operation that number of inches of track raise, as has been described above.

Properly oriented polarizing filters 161 are mounted on the

housings

151, 152 to provide the polarized light 9 discussed above. In the illustrated construction, the lower housing 152 also includes a hinged plate 162 which is adapted to be lowered over the front of the housing so as to protect the light and polarizing filter against inadvertent damage when the carriage is not in use; the low position of the housing 152 making it particularly vulnerable. If desired, all of the lights can be so protected.

The control circuit and summary of operation Each of the sensors 35 is operatively coupled to the jack 21 at the same side of the tamper 10. The sensor 35 over the grade rail controls the actuator 72 in the jack that is adjacent the grade rail, and a cross level sensor 170 controls the actuator 72 in the jack at the opposite side of the track (see FIG. 12). Control of the jacks is reversed when the opposite track rail is the grade rail.

The voltage signal created by the operating sensor 35 is amplified by an amplifier 171 and fed to a servo valve 172 which directs fluid to or from the jack actuator 72, and at a rate, dependent on the direction and magnitude of the signal received from the sensor 35. That is, when the light band 39 hits the lower portion of the sensor 35 a strong positive signal is developed and the servo valve 172 fully opens to drive the jack foot 23 downwardly. This lifts the track and the mask set 40 which creates the light band 39 so that the band raises along the face of the sensor 35 and, as the null position is approached, the voltage signal from the sensor approaches zero. The servo valve 172 gradually closes, the jack actuator 72 slows down and finally comes to rest when the beam from the mask set 40 hits the null position on the sensor 35. Similarly, if the beam 39 moves above the null position on the sensor, the servo valve 172 shifts to lower the track.

At the same time, the cross level 170, shown schematically in FIG. 12 as a pendulum-actuated variable resistor taking off a voltage signal varying with the swing of the pendulum, operates the opposite jack 21. The cross level 170 is mounted on the crossbeam 50 (see FIG. 3) so that as the grade rail jack lifts one side of the track, the beam 50 tends to tilt causing the cross level sensor 170 to generate a signal which is amplified by an amplifier 173 and fed to a servo valve 174 that controls the jack actuator 72 on the opposite side of the track. Thus, both jacks 21 are almost simultaneously actuated and the track is raised smoothly.

Preferably, the cross level sensor 1'7 includes a device 175 for varying the null or neutral position at which beam angle fails to produce a correction signal from the sensor 170. In other words, the sensor 170 can be set to maintain a predetermined cross level, and thus a desired track superelevation, i.e., difference in track rail height, can be automatically maintained. Also, the preferred circuit includes a pair of meters 176 positioned in the operators cab 15 and connected to visually indicate the signals developed by the surfacing sensor 35 and the cross level sensor 170.

For lining, the sensor 34 over the grade rail develops a signal varying in direction and magnitude which is amplified by an amplifier 181 and fed to a servo valve 182 that directs hydraulic fluid, at varying rates, to and from the lining actuators 75. The function of the lining sensor 34, and its servo valve 182, is like that of the surfacing sensor 35 and the servo valve 172. That is, there is rapid movement of the actuators 75 when a strong signal is developed by the sensor 34, and the valve 182 shifts to slow up movement of the actuator 75 bringing it to a halt as the light band 38 reaches the null position of the sensor 34.

It is important to note that the lining sensors detect and "respond to track deviations to either side of proper track alinernent. If the light band 38 strikes the right-hand portion of the operating sensor 34, the jacks 21 quickly shift the track to the left until the band 38 reaches the sensor null position. If the light band 38 strikes to the left of the sensor null position, the appropriate opposite correction is made. In both cases, the track is directly moved in the required direction for lining correction, thus minimizing track disturbance.

As another feature of the invention, the actuators are only hydraulically coupled, not mechanically interconnected, so that relative movement between the jack feet 23 can take place, and means are provided for returning the actuators 75 to predetermined starting positions after each lining operation. During lining, a solenoid operated on-off valve 185 is actuated so as to hydraulically interconnect the actuators 75. Fluid from the servo valve 182 flows to one of the actuators 75, and the exhausted fluid from that actuator moves the opposite actuator 75. A difference in hydraulic leakage, or slippage of the jack feet 23 in the ballast, can cause differences in lateral movement of the two jacks 21 but, in any event, lateral shifting pressure continues to be exerted on the jacks so long as the servo valve 182 is held open by a signal from the lining sensor 34.

After lining, the valve 185 closes, hydraulically disconnecting the actuators 75 and a pair of solenoid operated three-way valves 186 and 187 reposition the actuators 75. If the actuators 75 have driven the jacks 21 to the left, as seen in FIGS. 3 and 12, during lining, the microswitches 77 are closed, thus actuating the valves 186 and 187 so as to return the actuators 75 to the right. If the actuators had extended the jacks 21 to the right, the microswitches 78 would close returning the actuators 75 to the left. In either case, the actuators 75 are quickly returned to their predetermined starting positions wherein the microswitch operating earns 81 lie between the

microswitches

77, 78.

To insure that lateral movement of the jacks 21 does not take place until the jack feet 23 are firmly planted in the ballast and the track at least partially lifted, the lifting pressure ends of the jack actuators 72 carry pressure responsive switches 188 controlling normally open contacts 139 in the circuit between the lining sensor 34 and the servo valve 182. Thus, the servo valve 182 cannot be energized until pressure in the jack actuators 72 indicates that the track is lifted and ready for lining. At the same time, the pressure switches 188 also control normally open contacts 190 which serve to actuate the valve 185, and normally closed

contacts

191 and 192 in the actuating circuits for the valves 186, 187 respectively. Therefore, at the same time that the lining sensor 34 is electrically coupled to its servo valve 182, the valve 185 is operated to hydraulically couple the actuators 75, and the

contacts

191, 192 are opened to disable the

microswitches

77, 78. When the lining operation is complete and the actuators 72 lift the jack feet 23, the pressure responsive switches 188 are deactivated, opening the contacts 190 so as to return the valve 185 to its normal position breaking the hydraulic connection between the actuators 75, and also closing the

contacts

191, 192, so that the

microswitches

77, 78 operate in the manner described above to return the actuators 75 to their predetermined starting positions.

Preferably, manually operated switches 133 and 184, controlling

contacts

195 and 196 respectively, are provided to by-pass the

microswitches

77, 78 and permit manual actuation of the valves 186 and 187. Operating the switch 194 causes the valves 186, 187 to drive both of the actuators 75 inwardly moving the jacks 21 to transport position. Operation of the switch 183 extends the jacks laterally toward their operating positions.

While the combined lining and surfacing operation will now be clear, it can also be seen that surfacing can be done without also lining the track simply by deactivating the lining sensors or lining lights. Also, the lining sensors can be used alone to prelog track curves. For this latter purpose, a meter 200 is connected across the output of the sensor 34 to give the tamper operator in the cab 15 a visual indication of the magnitude and direction of the the sensor 34 are no longer alined. The operator then energizes the motor 112 shifting the mask set 40 which is in use inwardly of the curve until the meter 2% shows the mask set has shifted the light band 33 to the neutral or null sensor position. The reading on the mask scale 113 is then read and noted. The operation is repeated at any desired number of points on the curve. Knowing the spacing between the sensor 34, the mask set 40 and the lining light, it is then a simple matter to plot the actual shape of the track curve, compare it with the desired shape, and determine the readings of the scale 113 for each of the measured points which should appear if the curve were in the desired shape. Then, when lining the curve, at each of the previously measured points the tamper operator shifts the mask set 40 being used until the scale 113 reads the value for a proper disposition of the track at that point, and the lining circuit brings the track and the mask set to the desired null position. This operation is similar to using a lining cord to first measure a track curve and then control its adjustment into proper configuration.

We claim as our invention:

1. A track working assembly comprising, in combina tion, a tamper, jacks and rail clamps mounted on said tamper, a plurality of actuators coupled to said jacks for raising track and shifting it from side to side, a light carriage adapted for movement along the track, a first light source mounted on said carriage in a predetermined horizontal plane above the track, a second light source mounted on said carriage in a predetermined vertical plane along the track, a first light sensor mounted on said tamper in a predetermined horizontal plane above the track, a second light sensor mounted on said tamper in a predetermined vertical plane along the track, means for preventing said first sensor from sensing light from said second source and said second sensor from sensing light from said first source, a first mask on said tamper between said sources and said sensors and disposed to create with light from the first source a pattern on said first sensor, a second mask on said tamper between said sources and said sensors and disposed to create with light from the second source a pattern on said second sensor, a first circuit controlled by said first sensor for operating the actuators which raise the track, and a second circuit controlled by said second sensor for operating the actuators which shift the track from side to side.

2. The combination of claim 1 in which said means includes light polarizing filters over said sources and said sensors.

3. The combination of claim 1 in which said first sensor includes a vertical array of photocells, said second sensor includes a horizontal array of photocells, and said circuits couple the photocells of each sensor in electrically balanced circuits so that said light patterns create sensor output signals for operating said actuators except when the pattern strikes the sensors in predetermined null positions.

4. The combination of claim 1 in which said second light source .is mounted close to one rail of said track so that lateral tilting of said carriage has little elfect on the vertical plane in which said second source is mounted, and said second sensor is mounted at the upper rear of said tamper so that workmen in and around the front of said tamper do not block light passing from said second source to said second sensor.

5. The combination of claim 1 in which said second light source and said second light sensor are mounted at approximately the same distance above the track, and said vertical planes substantially coincide relative to the track so as to permit continuous side-to-side alining of the track with the tamper and the light carriage spaced at varying distances along the track. 7

6. The combination of claim 1 in which said tamper is adapted for on-track movement and operation, said jacks include a pair of ballast engaging jacks mounted at the forward end of said tamper one on either side of the track being positioned and tamped, and said plurality of actuators include separate actuators arranged to effect relative transverse movement of each of said two jacks relative to said rail clamps, said combination including means for returning said separate actuators to predetermined starting positions after each jacking operation.

7. The combination of claim 1 in which the mounting for said sensors includes a frame having a flanged wheel engaging one of the rails of said track, and the mounting for said masks includes a frame having a flanged wheel engaging the same rail of said track, said combination including means for urging said frames laterally so that said flanged wheels establish fixed lateral positions for the frames, and the masks and the sensors they carry, relative to the track.

8. The combination of claim 1 including means for disabling said second sensor until said actuators which raise the track have lifted the track.

9. A track working assembly comprising, in combination, a tamper, jacks and rail clamps mounted on said tamper, a plurality of actuators coupled to said jacks for raising track and shifting it from side to side, a light crariage adapted for movement along the track, a light source mounted on said carriage in a predetermined vertical plane along the track, a light sensor mounted on said tamper in a perdetermined vertical plane along the track, a mask on said tamper between said source and said sensor and disposed to create with light from the source a pattern on said sensor, and a circuit controlled by said sensor for operating the actuators which shift the track from side to side, said sensor creating a signal in said circuit elfective to move the track to one side or the other until said light pattern strikes the sensor in a predetermined null position.

10. The combination of claim 9 including means for varying the lateral position of said mask relative to the track, and means for visually noting said sensor signal so that the position of the mask can be varied until said null position is reached, whereby the mask position indicates track alinement or misalinement between said sensor and said light source.

11. The combination of claim 9 in which said sensor includes a horizontal array of photocells, and said circuit couples said photocells in electrically balanced circuits creating said null position.

12. The combination of claim 9 in which said light source is mounted close to one rail of said track so that lateral tilting of said carriage has little effect on the vertical plane in which said source is mounted, and said sensor is mounted at the upper rear of said tamper so that workmen in and around the front of said tamper do not block light passing from said source to said sensor.

13. The combination of claim 9 in which said light source and said light sensor are mounted at approximately the same distance above the track and said vertical planes substantially coincide relative to the track so a to permit continuous side-to-side alining of the track with the tamper and the light carriage spaced at varying distances along the track.

14. The combination of claim 9 in which said tamper is adapted for on-track movement and operation, said jacks include a pair of ballast-engaging jacks mounted at the forward end on said tamper one on either side of the track being positioned and tamped, and said plurality of actuators include separate actuators arranged to effect relative 13 transverse movement of each of said two jacks relative to said rail clamps, said combination including means for returning said separate actuators to predetermined starting positions after each jacking operation.

15. The combination of claim 14 including means for 5 selectively driving said separate actuators in opposite directions so as to elfect movement of said jacks from inboard transport positions to outboard operating positions.

16. The combination of claim 9 in which the mounting I for said sensor includes a frame having a flanged wheel engaging one of the rails of said track, and the mounting for said mask includes a frame'having a flanged wheel t the frames, and the mask and the sensor they carry, relative to the track.

References Cited UNITED STATES PATENTS 4/1967 Plasser et al. 104-8 8/1967 Plasser et al. 1047 ARTHUR L. LA POINT, Primary Examiner.

R. A. BERTSCH, Assistant Exami/zcla

Claims

1. A TRACK WORKING ASSEMBLY COMPRISING, IN COMBINATION, A TAMPER, JACKS AND RAIL CLAMPS MOUNTED ON SAID TAMPER, A PLURALITY OF ACTUATORS COUPLED TO SAID JACKS FOR RAISING TRACK AND SHIFTING IT FROM SIDE TO SIDE, A LIGHT CARRIAGE ADAPTED FOR MOVEMENT ALONG THE TRACK, A FIRST LIGHT SOURCE MOUNTED ON SAID CARRIAGE IN A PREDETERMINED HORIZONTAL PLANE ABOVE THE TRACK, A SECOND LIGHT SOURCE MOUNTED ON SAID CARRIAGE IN A PREDETERMINED VERTICAL PLANE ALONG THE TRACK, A FIRST LIGHT SENSOR MOUNTED ON SAID TAMPER IN A PREDETERMINED HORIZONTAL PLANE ABOVE THE TRACK, A SECOND LIGHT SENSOR MOUNTED ON SAID TAMPER IN A PREDETERMINED VERTICAL PLANE ALONG THE TRACK, MEANS FOR PREVENTING SAID FIRST SENSOR FROM SENSING LIGHT FROM SAID SECOND SOURCE AND SAID SECOND SENSOR FROM SENSING LIGHT FROM SAID FIRST SOURCE, A FIRST MASK ON SAID TAMPER BETWEEN LIGHT FROM THE FIRST SOURCE A PATTERN ON SAID FIRST SENSOR, A LIGHT FROM THE FIRST SOURCE A PATTERN ON SAID FIRST SENSOR, A SECOND MASK ON SAID TAMPER BETWEEN SAID SOURCES AND SAID SENSORS AND DISPOSED TO CREATE WITH LIGHT FROM THE SECOND SOURCE A PATTERN ON SAID SECOND SENSOR, A FIRST CIRCUIT CONTROLLED BY SAID FIRST SENSOR FOR OPERATING THE ACTUATORS WHICH RAISE THE TRACK, AND A SECOND CIRCUIT CONTROLLED BY SAID SECOND SENSOR FOR OPERATING THE ACTUATORS WHICH SHIFT THE TRACK FROM SIDE TO SIDE.