US2388819A

US2388819A - Railway switch operating apparatus

Info

Publication number: US2388819A
Application number: US510005A
Authority: US
Inventors: Herbert L Bone
Original assignee: Union Switch and Signal Inc
Current assignee: Hitachi Rail STS USA Inc
Priority date: 1943-11-12
Filing date: 1943-11-12
Publication date: 1945-11-13
Anticipated expiration: 1962-11-13

Description

Nov. 1-3, 1945.

H. L. BONE RAILWAY SWITCH OPERATING APPARATUS 8 Sheets-Sheet 1 Filed Nov. 12, 1943 Hf! ATTORN EY Nov. 13, 1945. H, BONE RAILWAY swrrcn OPERATING ArPARATus Filed Nov. 12, 1943 8 Sheets-Sheet 2 fig Q Q H11 ATTORNEY A Nov. 13, 1945. A H L, BON 2,388,819

RAILWAY SWITCH OPERATING APPARATUS Fil'ed Nov. 12, 1943 8 Sheets-Sheet 4 INVENTOR rfip [.3000 '9 M i.

H11 ATTORNEY Nov. 13, 1945. H. L. BONE 2,388,819

RAILWAY SWITCH OPERATING APPARATUS 'Filed Nov. 12, 1945 8 Sheets-Sheet 6 55a lNV NTOR H11 ATTORN EY RAILWAY SWITCH OPERATING APPARATUS Filed Nov. 12, 1945 8 Sheets-Sheet 7 INVENTOR Hf! ATTORNEY Nov. 13, 1945. H. BONE RAILWAY SWITCH OPERATING APPARATUS I INVENTOR ATTORN EY Patented Nov. 13, 1945 UNITED STATES PATENT OFFICE RAILWAY SWITCH OPERATING APPARATUS Herbert L. Bone, Forest Hills, Pa., assigno'r to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application November 12, 1943; serial No. Simone 8 Claims; (c1. 246- 242) My invention relates to railway switch operating apparatus, and particularly to railway switch operating apparatus of the so-called dual-com trolf' type in whichmeans are provided for operating a switch either by power or by hand depending upon the position of a manually op'er-" able selector lever. Y

The principal object of my invention is to insure the safety of trains and vehicles moving over railway switches.

Another object of my invention is the provision in apparatus of the type described of means for preventing creeping of the switch throwing mechanism from either extreme position due to vibration.

Another object of my invention is the provision of novel means operated by the selector lever for cutting on the supply of powerto the power operating means before the hand operatin means can be connected with the switch.

A- further object of my invention is" the provision of a novel and improved circuit controller for detecting any failure of the switch points to occupy theirip'roper positions relative to the stock rails in either extreme position of the switch. 7

A still further object of my invention is the provision of novel and improved latching mechariism which may be incorporated into the circuit controller when desired, and which, when utilized, provides means whereby, if the indication contactsof the circuit controller are improperly forcedopen, as by a train trailing the switch, when the switch points are locked in either extreme position, these contacts will be positively held open by the latching mechanism with the latching mechanism is manually operated to release the contacts.

According to my invention, the mechanism includes a main switch operating crank selectively connected through" the medium of a; clutch operated by a manually operable selector lever'with a first gear operated by a hand throw lever ojr'a' second gear operated by an electric motor. The

hand throw lever and selector lever are on" a common axis and are interlocked in a manner which prevents operation of the hand throw" lever except when the selector lever occupies its hand throw position. The selector lever operates the clutch through the medium of a bell crank prd'-' vided on the inner end of the leverand cooperating with a pivoted yoke which straddles the clutch. The clutch is op'eratively connected through suitable linkage with motor cutout con"- tactsin such manner that operation of the clutch to the motor operating position willopen these operating crank cooperates with a suitable t row bar to" reverse the switch and also with a locking plunger which latter cooperates with a, 10m rod secured to the switch points to lock the switchin its two extreme positions. The locking plunger carries a rack which actuate's a circuit controller for controlling the energization of the motor. This Controller includes indication contacts. These contacts are arranged in pairs and are moved to their op rated positions either by it can't ofieratedby said rack or by a point detector mechanisfn operated' by a pointdete'ctor rod con: nected to the switch points. The point detector incriidesiattn mechanism which is effective t retain the indication contacts in their operated petitions if they are moved to these positions by displacement of the switch points from their nor mal locked positions, due for example, to a train tra ling the switch. r 7

Other objects and characteristic features of my invention will become'apparent as the description proceeds V U I shall describe one form of railway switch o'pl crating apparatus embodying' my inventionfiantl shall then point out the novel featuresthere'of claims.

In the accompanying drawings} Fig; Us a top plan view" showing one form Of railway switch operating apparatus embodying my'invention', the covers for the" apparatus being removedor broken away to niustmte the detail parts. Fig} 2 is a" longitudinal verticalsectional view of the app'a-ratus illustrated in Fig; 1. Fig. 3 is a view; partly diagrammatic and partly in horizontal section, showing certain of the parts of the apparatus illustrated in Figs. 1 and 2 connected with a railway Switch in the intended manner, Fig; l is a bottom viewof the clutch sleeve 25 forming part of the clutch of the apparatus shown in Figs. 1 and 2i Fig. 5' is a top plan View or the gear" Wheel r5 f orming part or the apparatu's' illustrated in'r'i 's. 1- and 2. Fig; 6 is a; topview of the clutch sleeve 24 forming" part of the clutch for the a paratus illustrated in Figs". and; 2. Fig. 7 is a" bottom View of the gear wheel lflf forming" part of the apparatus illustrated in Figs; 1- and 2; Fig. 8 is a view' similar to Fig. '1 showing a modified form of gear wheel'sometimes employee ii theap aratus in ace of the ear wheel ll. Fig. 9 is' a sectional View taken on the Similar reference characters refer to similar parts in each of the several views. Referring to the drawings, the reference character I designates a housing provided With'removable covers 2 and 3, and adapted to belmounted adjacent a railway track switch S shown diagrammatically in Fig. 3. Journaled in vertically aligned

bearings

4 and 5 disposed within the housing I is a vertically extending shaft 6,--the lower end of which carries a crank I. This crank extends 'in'opposite directions from the shaft, arid'js provided on its lower side with a crank pin .8 carryinga'roller 9, and on its upper side with rounded upstandingprojections I0 and .II (see Fig. 3) disposed on opposite sides of the shaft. The roller 9 cooperates witha cam slot 9a formed inan operating rod 0, while the, pro- 'jections Ill and II cooperate, respectively, with sp'aced recesses Illa and I I a formed in the underside of a slide bar N. The operating rod 0 is slidably mounted in the bottomof the casing I at one side. of the axis of the shaft 6,. and is operatively connected at one 'of its outer ends .with the switchS. The slide bar N is slidably mounted in the bottom of the casing I in a position inwhichit intersects the operating rod 0.

atrightfa'ngles, and is providedat its left-hand end witha locking plunger: l 2 provided with vertically oif'set and longitudinally Spaced locking dogs I2a and Ilbv (Fig.2) which are adapted to selectivelyehter spaced notches I3a and I31) provided in alock rod 'L operatively connected with the switch points of the switch S. The lock rod Llis of. well-known construction, and is slidably mounted in the bottom of the casing .I at right angles to the slide bar N, as is obvious.

The portion of the switch operating ar'ipa'ratus thus far described is essentially the same as that described and claimed in Letters Patent of the United States No. 293,290, granted to William Zabel on February 4, 1919, for Railway traffic controlling apparatus, and its operation, briefly described, is as follows: When-the operating rod 0 and the slide bar N are in their normal positions, and the switch'points of the switch S'are in their corresponding'positions, as shown in Fig. 3, the locking dog I20. is disposed within the notches l3a in the lock rod L, and under these conditions the switch points are securely locked in their normal positions by'the locking dog I2a.

When it is desired to reverse the switch S, the

shaft Bis rotated in a clockwise direction from the extreme position shown to its opposite extreme position. The initial part of this rotation,

usually about'the first 30, causes the projection ID on the crank I to engage the left-hand wall of the recessullla in the slide bar N1, and'move the slide bar 'toward'the left far enough to withdraw the locking dog I2a from the notches I 3a in the lock rod L. During this initial movement of the crank the roller 9 whose initial position wasat the, left-hand end of the cam slot 9d is moved tothe medial portion of the slot, that is to say, to a point just a little to the leftof the junction of the curved and straight walls thereof, but due to the curvature of the upper Wall of the cam slot, this movement of the roller does not cause any movement of the operating rod 0. It will be seen, therefore, that during the first part of the movement of the crank I the slide bar N is moved to unlock the switch points, but the operating rod 0 and the switch points remain stationary. However, in the continued movement 'of the crank, the roller9 engages the lower straight side of the cam slot 9a and moves the operating rod 0 in the direction that the crank is moving to thereby move the switch points to their reverse positions. This latter or intermediate movement of the crank will usually rotate the crank through an angle of approximately 180. Upon further continuedmovement of the crank, projection II enters the recess I Ia and imparts a second movement to the slide bar N in the same direction as the first movement, which latter movement causes the locking dog lZb to enter the notches I3b in the lock rod L and lock the switch in its reverse position.

When the parts have been operated to themsitionsjust described, and the crank is rotated in a counterclockwise direction to restore the parts to the positions shown, the sequence of movements, of .the operating rod andslide bar are maintained, but the directions-of the movements are reversed. a

For convenience I shall hereinafter refer to the initial movement of the crank from eitherextreme positiontoward the other as the unlocking stroke, the intermediate portion as the switch operating stroke, and the final movement asthe locking stroke. I

Itshould be. particularly pointed out that with the apparatus constructed .in the manner just described, upon the completion of the switch operating stroke in either direction of rotation of the crank], the roller Swill have just entered the curved portionlof the cam slot 9a, and that when the parts are in these positions if the crank is prevented from rotating in the direction to move'the roller out of the curved portion of the cam slot, the switch will. be effectively held, by

the cooperation'between the roller and the operating rod, in the extreme position it then occupiesirrespective of the fact that it is unlocked.

, It follows, therefore, that if suitable precautions are taken to prevent the crank from creeping upon the completion of the switch operating plunger. For thepurpose of preventing the crank from creeping'under these conditions, and. also when the switch is locked in either extreme position I. provide anti-creep means which I shall now "describe.

As here illustrated, these means comprise a spring pressed plunger I4 (see Fig. 1) which cooperates with a. main bevel gear I5 rotatably mounted on. the shaft 6 directly above the lower bearing 4. The bevel gea I5" is operatively connected with power drivingmeans here shown as an electric motor M, through suitable reduction gearing indicated in the drawings by dash-lines I6, and is arranged to be at times connected with the shaft 6 by suitable clutch mechanism which I shall described presently. The spring pressed plunge I4 is mounted in an auxiliary housing I la bolted to the side of the main casing I, and cooperates at its inner end with four inclined camsurfaces I 511, I52), I50 and l5d-formed on .the periphery of'the'main bevel gear. The cam surface. lid is sopositioned that any movement of the mechanism away from its full normal position' will cause the plunger M to ride up onto this cam surface the cam surface. I511 is sopositioned thatany movement of the mechanism away from its full reverse position will cause the plunger to ride up onto this cam surface; the camsurface [5b is so positioned that any move ment of the mechanismaway from the end of the switch operating stroke in the direction. tomove' the switch from its normal toward its reverse position will cause the plunger It to ride up onto this cam surface, and the cam surfacel5cis so positioned that any movement of the mechanism away from the end of the switch opcrating stroke in the direction to move the switchfromits reverse to its normal position willcause the plunger M to ride up onto this surface. The

strength of the spring- Mb which urges theplunger into frictional contact with the peripheryof the main bevel gear is such that the force necessary to cause the plunger to ride up" onto any one of the cam surfacest5a, [51), E50 orl5d is greater than any force resulting from vibration tendingto cause the-switch operating mechanism to creep, but isin-su-fiicient to interfere with the normal operation of the mechanismby the power driving means or by the-hand throw means presently to be described.

An auxiliary-bevel gear I! (Figs. 2- a-nd 9-) is also rotatably mounted on the shaft 6 between the upper-bearing 5 and the upper end of abushing [8, the lower end of which bushing rests on a shoulder l9 formed on the shaft 6; The bevel gear I' l meshes with a second bevel gear fixed to the end of a horizontal-1y extending sleeve 2| rotatably mounted in suitable bearings provided in a bearing support 22 bolted to the side of' the main casing I. Secured to the outer end of the sleeve H is a hand throw lever 23, by means of which the sleeve 2!, and hence the bevel gear 20 may at times be rotated between two extreme positions.

The main bevel gear l5 and the auxiliary bevel gear I"! are arranged to be selectively connected with the shaft 6 to permit the shaft to be operated by the motor or by the hand throw lever 23, by means of a clutch mechanism A (see Fig. 9). As here shown, this clutch mechanism comprises two

sleeves

24 and 25 which are mounted on the shaft6 for verticalsliding movement between; the two gears l5 and H, but which are constrained to rotate with the shaft 6 by means of integral internal splines 26 which cooperate with corresponding splines 6a formed on the shaft. The two

sleeves

24 and 25 are secured together at their confronting ends to cause them to act as a unit, and are provided at their upper-and lower ends, respectively, with circumferential flanges 24a and 25a which form confronting shoulders 24?) and 25b. Surrounding the sleeves 24 and 25' between the shoulders 24b and 25b is a compressed coil spring 28. engages a cupped spring thrust washer 270' and constantly urges it to the position in which it engages the shoulder 24b, and the other end of this spring'engages a cupped spring thrust washer- 2! and constantly urges it to the position in which it engages the shoulder 25b.

The lower end of the sleeve 25 is formed with tapered projections 29 (see Figs; 4 and 9) which cooperate with tapered recesses 30 (see-Figs. 2 and 5) provided in the hub of thebevel gear I 5, whereby when the clutchmechanism is in its lower position: as shown, the shaft disconnected One end of this spring to the main bevel gear l5 to enable the mechanism to be power operated in the normal m'an'-= ner. The projections 29 are unevenly spaced about the sleeve, three such projections being provided. It will be seen, therefore, that with the parts constructed as shown, the clutch can become connected with the gear wheel I 5 in only one angular position. It should be understood, however, that any desired number of projections may be provided.

The upper end of the sleeve 2 is provided with a single projection 3! (see Fig. 6) which cooper-' ates with a, recess 32 (see Fig. 7') formed in the lower face of the bevel gear ll. When it is de-- sired to permit the switch to be locked in either extreme position by means of the hand throw lever, the projection 3! will usually be made with an angular length which is just slightly less than the angular length of the recess 32', and the parts are so proportioned that under these conditions rotation of the hand throw lever 23 between its two extreme positions will rotate the switch actuating shaft between its two extreme positions in the same manner that this shaft is rotated be-- tween its two extreme positions by power opera*- tionwhen the clutch is in engagement with the bevel gear l5. For example the projection 3} may have an angular length of just slightly'lessthan 180", while the recess 32' may have an angu-- lar length of just slightly more than 180. It will be understood, however, that this proportioning of the parts is given merely by way of example, and not by way of limitation, and that other satisfactory proportionings of the parts may be readily effected.

Under some conditions of operation it is desirable to be able to reverse the switch; by the hand throw lever 23 without. causing it to'becomelocked by the lock rod'in its extreme positions. With the mechanism constructed as shown, this result can be accomplished by replacing the bevel gear i=1 with a; bevelgear' lla- (see Fig. 5%) having arecess 32a of longer are. than the: recess 32' of the gear. Isl. For. example, the recess at may be made 240? long. When. the gear ii. is replaced by the gear Ila, the anti-creeper. mechanism described hereinbefore' will act; to retain. the switch. points in either." extreme position. to which they" are moved by the hand throw lever even though the switch is. not locked by the: lock rod in. such extreme position, thus permitting: trains: to be safely moved over: the: switch at reduced speeds; The: overall length of the clutch mechanism including the projections 29 and: Si is such; that it cannot be disengaged. from one. gear until it. first becomes engaged with the othergear. It follows, therefore, that the shaft tv will always be engaged with either the power or. the hand throw gearing,

The clutch mechanism A is arranged: to: be moved longitudinally on. the shaft 6 to. effect the desired driving connection between thebevel gear H and the shaft 6 or the bevel gear he and the shaft 6 by means of a. U-shapedishifterzforlc. 35: (Figs. 1, 2 and 9) the'arms 351a. and sst: of. which straddle the clutch. mechanism and are pivotally supported on pivot pins. 36 mounted in spaced lugs 37 provided on a removable plate 3.8 bolted to one side of the housing I. secured to: the arms 35a and 351)- on opposite sides of the clutch; mechanism are spaced rollers 39;. the upper ones of which overlie the flange of the spring cup: Washer 210 and the lower ones of which underlie: the. flange of the springv cup washer. 21'. The spacing betweenthe tw rollers. on each arm: is made.

slightly greater than the spacing] betweenthe upper and lower sides respectively of the :fianges on the two cup washers whenthese washers are engaging the associated shoulders 24b and 25b, for a purpose whichwill appear presently;

The web portion 35c of the shifter fork 35 is provided with an opening 4|! which cooperates with a rounded pin 4| formed on the inner end of a shaft-42 in eccentric relation with respect to the axis of the shaft. The shaft 42 extends through, and is rotatably mounted in, the sleeve 2|, and is provided at its outer end with a selector lever 43 by means of which the shaft may at times be oscillated. e

The operation, as a whole, of the portion of the apparatus thus far described is as follows: Normally the selector and hand throw levers both occupy the positions in which they are shown in Fig. l, which is the position for power operation, and under these conditions, the shifter fork 35 is rotated by means of the rounded pin 4| to its lowermost position. The parts are so propor-- tioned that, when the shifter fork occupies this position, if the projections 29 on the lower end of the clutch sleeve 25 are then in alignment with the recesses 39 in the bevel gear [5, the clutch will move to its lowermost position, and will thereby condition the apparatus for power operation in the manner pointed out hereinbefore. When the clutch assembly 'is in its lowermost position, it is supported by the top face of the hub of the gear l5, and the parts are further so proportioned that all four rollers 39 will be clear of the flanges of the spring cup washers, so that under power operation no load is carried by these rollers. It will be understood, of course, that when the mechanism is operated by the motor, the switch actuating shaft 6 will be rotated through its full operating stroke, so that the switch will become locked in either extreme position to which it is moved.

If, when the selector lever is moved to the power operating position, as shown, the projections 29 on the clutch sleeve 25 do not align with the recesses 30 in the hub of the bevel gear l5, so that the clutch sleeve is prevented from moving to its lowermost extreme position by engagement of the lower ends of the projections 29 with the upper side of the hub of the bevel gear, the shifter fork 35 will still be rotated, to its lowermost position, but under these latter conditions, the rollers 39 will act through the cup' washer 210 to exert a force on the spring 28 which causes it to become compressed and bias the clutch assembly toward its lowermost position. As a result, as soon as the bevel gear 15 is rotated by the motor to the position in which the projections 29 align with the recesses 30, the clutch will immediately snap to its lowermost position in which it is shown in the drawings.

When the switch is in condition for motor operation, the bevel gear I1 is disconnected from the switch actuating shaft 8, and the hand throw lever is therefore disconnected from the switch.

When it is desired to disconnect the motor from, and connect the hand throw lever 23 with the shaft 6, the selector lever is rotated from the motor operating position in which it is shown in the drawings to its opposite extreme or hand throw position. This rotation acts through the shaft 42 and rounded pin 4| to rotate the shifter fork from its lowermost to its uppermost position. During this rotation the lower rollers 39 on the shifter fork engage the underside of the flange on the lower spring cup washer 211 and move it upwardly with the shifter fork. The upward movement of the cup washer, in turn, exerts a force on the spring 28 which is transmitted through the spring and cup washer 210 to the interconnected clutch sleeves, and under normal conditionsthis force will cause the sleeves to move upwardly as soon as the shifter fork starts to moves However, should the switch operating apparatus hap pen to be standing with the power gear train stopped by the inertia of the rotating parts upon the completion of the previous reversal ofthe mechanism, the static torque which then exists between the engaging sides of the projections 29- and recesses 30, may be suflicient to prevent the assembly from starting to move upwardly even though spring 28 becomes fully compressed. The parts are so proportioned that under these latter conditions, the flange of the cup washer 21 will move into engagement with the flange of the cup washer 210 before the shifter fork reaches its upper extreme position, and when this happens, 'a positive force will be exerted on the clutch sleeves, which force is sufficient to overcome the static torque between the lower sleeve and the gear wheel l5 and thus cause the clutch assembly as a whole to move upwardly under the bias of the compressed spring 28. a

When the clutch assembly starts to move up wardly, if the recess 32 in the bevel gear I! is then in alignment with the projection 3| on the sleeve 24, as will be the case when the switch and hand lever occupy corresponding extreme positions and the switch is fully locked in the extreme position it then occupies, the spring 28 will cause the clutch to move to its upper extreme position in which the projection 3| enters the recess'32. The bevel gear i! will then be connected with the shaft 6 in such manner that the switch may be rotated between its two extreme positions and locked in either extreme position to which itis moved by the hand throw lever 23 in the same manner that it is rotated between its two extreme positions and is locked in either extreme position by power operation. If, however, the recess 32 in the bevel gear is not in alignment with the projection 3| or the sleeve 24 of the clutch assembly when the clutch assembly starts to move upwardly, the spring 28 will become compressed and permit the shifter fork to complete its upward movement. Under these conditions, as soon as the hand throw lever is rotated to the position in which the recess 32 aligns with the projection 3|, the spring 28 will act to force the clutch assembly to its full upper position. This alignment; of the recess with the projection 3| will always occur at some point in the stroke of the hand throw lever,-

and if the switch happens to be in a position op-' posite to that of the hand throw lever when the selector lever is operated to the hand throw position, then the hand throw lever will rotate freely without engaging the clutch until the hand throw lever is fully reversed.

Associated with the hand throw lever 23 and the selector lever 43 is'a mechanism D includin means for locking the levers against movement by unauthorized persons and means for interlocking the levers in such manner that the hand throw lever cannot be operated unless the selector lever occupies the hand throw position. This mechanism forms no part of my present invention, and may for example, be similar to that described and claimed in Letters Patent of theUnited States N0.

1,887,376, granted to G. V. Jefferson and E. J. Little on November .8, 1932, for Railway switch op- D forms no part of my present invention it is iieemed unnecessary to describe it in detail here- Mounted in the left-hand end of the housing I above the lock rod L and the slide bar N is a circuit controller G for indicating when the switch is locked and the closed switch point is in proper engagement with the associated stock rail. As best seen in Figs. to 13, this circuit controller comprises a suitable supporting frame work 50 provided with aligned

bearings

51 and 52 in which a horizontal camshaft 53 is iournaled. The camshaft 53, which is of rectangular cross section except for a rounded portion at each end which fits into the associated bearing, is adapted to be rotated or oscillated in response to longitudina1 movements of the slide bar N, and for this purpose the shaft 53 has fixed thereto a gear wheel 54 which meshes with the teeth of a rack bar 45 secured to the upper face of the locking plunger l2. Mounted on the camshaft 53 on opposite sides of the gear wheel 54 are a plurality or driving collars of insulating material, each designated by the reference character 55 with a suitable distinguishing exponent. Each driving collar 5-5 is provided with a square hole which has a sliding fit onthe camshaft 53, and as clearly shown in Fig. 11, each driving collar comprises a comparatively narrow web and a peripheral flange extending in each direction from'the outer edge of the driving collar. A portion of the peripheral flange of each driving collar is tapered, and the tapered portion is provided with serrations or teeth (not shown) around its entire circumference. Each driving collar 55 carries a metal contact segment of electro-conductive material designated by the reference character 55 with the same distinguishing exponent as the exponent for the reference character of the associated collar. Each contact segment is in the form of the segment of a ring, the base of which is tapered to fit the tapered portion of the periphery'of the associated driving collar. The base of each driving collar is also provided with serrations or teeth (not shown) which match the teeth on the periphery of the insulated driving collars. Each contact segment 55 cooperates at its periphery with a contact finger designated by the reference character 5'! with the same distinguishing exponent as the reference character for the associated contact segment. For example, the contact segment 56a cooperates with the contact finger 51a to at times close a contact 56a-51a. The periphery of each contact segment may have any desired length, and due to the mating teeth on the driving collars, the segment may be turned to any desired position relative to the camshaft 53. The two contact segments 56a and 561) are connected. together by a bar 58 and are so adjustw that these segments will each engage the associated contact finger to close the contacts formed thereby at all times except when the slide bar N is in the extreme position in which it locks the switch points in their normal positions. The two contact segments 55c and 56d are similarly connected together by a bar 55 and are so adjusted that these segments will each engage the associated contact fingers at all times except when the slide bar N occupies the ex treme position in which it locks the switch points in their full reverse positions. The contacts -5Ba5la, 5619-5112, 5Sc-5lc and Stat-51d may be used in a wellknown manner to control the circuits for the motor M or for any other desired purpose.

The circuit controller also comprises a pair of contact fingers 69a which are connected: together for simultaneous movement by an insulating bridge fila, and a pair of contact fingers Bill) which are connected together for simultaneous movement by an insulating bridge Gib. The fingers Sea. and 601) are biased by their own resilience to lower positions in which they engage associated lower

stationary contact members

62a and 62b to close a pair of contacts 6Ela-62a and a pair of contacts GNP-52b, but are adapted to be at times moved upwardly, by means of point detector mechanism which I shall now describe, to upper positions in which they engage an upper stationary contact member 63' to thereby close a contact 6eafi3 and Bub-63.

As best seen in Figs. 11 and 15, the gear wheel 54 which drives the camshaft 53 is formed with oppositely disposed

hubs

54a and 54b, and mounted on the camshaft 53 between the hub 54a and the driving collar 55b is a washer 65a and a bushing 6611. A washer 65b and a bushing 56b are similarly mounted on the camshaft between the hub 54b and the cam 550. The

bushings

66a and 6% are formed with "portions 61a and 611) which are eccentric with respect to the camshaft, and with other portions SBa-and 681) which are concentric with respect to the camshaft, and are disposed on the camshaft with the concentric portions 63a and 68b nearest to the

adjacent hubs

54a and 54b, respectively. The hubs 54a'and 54b carry cams 69a and 691), respectively, which are connected to the gear 54 to rotate therewith in- The a manner which I shall describe presently. cam 69a is provided in its preiphery with an arcuate notch Illa (see Fig. 12), and is adapted when rotated to actuate the contact fingers a through the medium of a roller Ha attached to the insulating bridge Bio. The cam 69?) is likewise provided in its periphery with an arcuate notch 10b (see Fig. 2), and is adapted when rotated to actuate the contact fingers 601) through the medium of a roller Hb attached to the insulating bridge Bib. The parts are so proportioned that when either notch is opposite the associated roller, the fingers are free to move to their lowermost position, but that, when the notches are not opposite the rollers, the associ ated fingers will be lifted into engagement with contact member 63. The

cams

69a and 6% are so arranged and the notches 10a and 1019 are of such lengths that both sets of fingers 60a and v 601) will be lifted when the slide bar N is in transit, but that one pair of fingers will normally be permitted to assume their lower positions when the slide bar N is at one extreme end of its stroke, and the other pair of fingers will normally be permitted to assume their lower positions when the slide bar N is at the other extreme end of its stroke, as will be described more fully hereinafter.

The means referred to hereinbefore for oper-' between the slots 16a and 11a is such, and the parts are so arranged, that when the pin 15a is within the slot 1611 the notch 10a in the cam 69a will align with the roller 'lflawhen and only when the slide bar N occupies the extreme position in which it is shown in the drawings, but that when the pin 15a is within the slot "a the notch 10a .in the cam 69a will then align with the roller Illa when and only when the slide bar N occupies its opposite extreme position. Similarly, the spacing between the slots 16b and 11b is such that when the pin 15b is within the opening 161), the notch 10b in the cam 691) will align with the roller b when and only when the slide bar N occupies its normal extreme position shown in the drawings, whereas when the pin 15b is within the slot "b, the notch 10b in the cam 69b will align with the roller Hb when and only when the slide bar N occupies its reverse extreme position. The cams will usually be mounted on the hubs in such positions that the notch in one cam will align with the associated roller in one extreme position of the switch and the notch in the other cam will align with the associated roller in the other extreme position of the switch.

In order to enable the switch operating apparatus to be used in either a right-hand or a left hand installation, it is desirable to be able to readily change the cams 69a and 6912 from the positions in which the associated pin 15 extends into either one of the slots 16a and 11a to the position in which it extends into the other open-' ing, and for this purpose the cams 69a and 691) are provided at the side opposite to that in which the slots 16 and 11 are formed with counterbores 18a and 18b. These counterbores are slightly larger in diameter than the

adjacent washers

55a and 65b, and the parts are so proportioned that when it is desired to rotate a cam from the position in which-the associated pin 15 enters the one slot in the cam to that in which it enters the'other' slot this can be done bymerely sliding the cam outwardly along the associated hub of the gear wheel 54 far enough to disengage the pin from the slot, rotate the cam until the other slot aligns with the pin, and then move the cam inwardly along the hub to the position in which the pin enters the desired slot. The cams are held in the position in which the associated pin 15 is within the desired slot by means of coil springs 19a and 79b disposed in the counterbores. As here illustrated the cam 69a occupies the relative position on the hub 54a in which the associated pin 15a is within the slot 76a, while the cam 69b occupies the relative position on the hub 54?) in which the associated pin 15b is within the slot 11b. With this arrangement, insofar as the control of the

contact fingers

60a and 60b by the cams 59a and 59b is concerned, the contact fingers 60a will be held in the positions in which the contacts Gila-62a are open and the contact Gila-63 is closed except when the slide bar N occupies the extreme position shown in Fig. 3, and the contact fingers 60b will be held in the positions in which the contacts 69b52b are open and the contact 60b63 is closed at all times except when the slide bar N occupies the extreme position opposite to that in which it is shown in Fig. 3.

The

contact fingers

60a and 60b are further controlled in accordancewith the positions of the switch points through the medium of two cams Blaand 8lb (Figs. l0 and 15) which are formed on the

arms

82a and 82b of a U-shaped contact operating member 82, and which cams diate their ends on theportions 68a and 68b of the

bushings

66a and 66b which are concentric with respect to the camshaft 53, and are provided at their free ends with open end slots' 84a and 841) which slidably receive

pins

85a and 85b mounted on the short laterally projecting arms 86a and 86b of two operating levers 81a and 81b. The levers 81a and 8112 are journaled on the portions 61a and 61b of the

bushings

66a and 66b eccentric with respect to the camshaft 53 and are further provided with forked depending arms 88a and 881) which are pivotally connected to adjustable operating rods 89a and 89b, respectively. The free ends of the operating rods 89a and 89b, in turn, are connected with the up standing arms 99a and 901) (see Fig. 13) of point detector levers 9|a and 9!!) pivotally supported on pivot pins [92a and I92?) mounted in suitable supports formed in the housing I.

The levers 9m and 9H) are provided in addition to the upstanding arms 90a and 90b with depending feet 92a and 9212 which carry rollers 93a and 93b and with laterally projecting

arms

94a and 94b. Tension springs 95a and 951) are connected at one end to the arms 94a'and 94b and at the other end to lugs 96:; and 96b cast on the housing I, and constantly bias the levers to positions in which the associated roller 93 engages a point detector rod D slidabl mounted in the housing I for movement in directions parallel to the camshaft 53. The detector rod D is adapted to be adjustably connected to the movable switch points of the switch S as indicated diagrammatically in Fig. 3, by a well-known form of adjustable connection (not shown), and is provided with an annular notch or recess 91 which aligns with the roller 93a when and only when the switch points occupy their proper normal positions and with the roller 931) when and only when the switch points occupy their proper reverse positions.

The bushings 66a and 86?) are provided with square holes to fit the camshaft 53, and it follows that these bushings can'be mounted on the camshaft in any one of four positions spaced 90 apart. The eccentricity of the eccentric portions 61a and 61b is arranged So that the line extending from the eccentric center to the center of the shaft 'is spaced 30 from the nearest line extending from the center of the shaft at right angles to one of the sides of the square hole, and the bushings are assembled on the shaft in such relative positions and the parts are so proportioned that when the notch 91 in the point detector rod D is in alignment with either roller 93 the spring 95 connected with the point detector lever 9| to which such roller is attached will rotate this lever to the position in which the roller enters the notch, and that under these conditions both springs '95 will act through the associated point detector lever 9|, the associated operating rod 89, operating lever 91', pin 85, and open end slot to rotate the contact operating member 82 to the position in which a stop shoulder 82c (see Fig. 12) formed in the yoke portion of the contact operating member engages a stop. arm I01 secured to the frame 50 of the controller,.

The parts are still further so proportioned that if either roller is forced out of the notch in the point detector rod when the switch is locked inthe extreme position in which the notch aligns with such roller, as by a train trailing the switch, the resulting movement of the associated point detector lever 9I will act through the associated operating rod 89, operating lever 86, pin 85, and open end slot 84 to rtate the contact operating member 82 in a clockwise direction, as viewed in Fig. 2, to such a position that the cams 8Ia and 8Ib will then engage the rollers Ila and Nb and will thus move the contact fingers to their upper positions in which they engage the contact member 63, but that, when the switch is moved from either extreme position to the other by the operating apparatus, the resulting movement of the camshaft 53which takes place during the unlocking stroke of the slide bar N will act through the eccentric portions 67a and 67b of the

bushings

66a and 66b and associated linkages to rotate the point detector levers to positions in which both rollers are clear of the point detector rod, and these rollers will be subsequently retained out of engagement with the .point detector rod until the switch becomes locked in its reverse position.

It will be seen; therefore, from the foregoing that when the switch occupies its normal position in which it is shown in Fig. 3, and is locked in this position by the slide bar N, the notch Illa in the cam segment 69a will align with the roller lla and the cam Illa will be out of alignment with the roller Ha as shown in Fig. 12, and under these conditions the fingers 60a will assume their lowermost positions in which the contacts 60a- 62a are closed and the contacts Ella-63 are open. Likewise, when the switch occupies its reverse position, and is locked in this position by the slide bar N, the notch 'Hlb in the cam segment 6% will align with the roller IIb and the cam 8Ib will be out of alignment with this roller, and the fingers 60b will therefore assume their lowermost positions in which the contact Nib-62b are closed and the contacts Ebb-4S3 are open. When, however, the switch is being moved from one extreme position to the other, the notch 10a in the cam segment 69a will be out of alignment with the roller Ho and the notch 10b in the cam segment 6% will also be out of alignment with the roller Ilb, so that under these conditions both sets of contact fingers 60a and Bill) will be moved to their raised positions in which the contacts 60a62a and 6'0b62b are open and the contacts 68a63 and 60b-63 are closed.

It should be particularly noted that while the switch is being moved from either extreme position to the other, the tension springs 95a and 95b constantly exert a force on the contact operating member 82 which is considerably greater than that due to any friction which may exist between the operating lever 86 and the associated eccentric portions of the bushing 66 tending to rotate the contact operating member 82 in a clockwise direction, as viewed in Fig. 2, and that as a result the contact operating member remains stationary in the position in which the stop shoulder 82c engages the stop arm IEII during the reversal of the switch. Consequently, while the switch is being reversed the rotation of the

eccentric bushings

66a and 6% resulting from the unlocking and locking strokes of the switch operating crank causes the operating levers 85a and 86b to traverse an orbit which slides the

pins

85a and 85b longitudinally in the

slots

84a and 81b, and which acts during the unlocking stroke of the switch operating crank to move both rollers away from the point detector rod to positions in which both rollers are completely clear of the rod, and during the subsequent locking stroke to move both rollers toward the detector rod to such positions that at the end of the lockin stroke the roller which was initially out of the notch in the detector rod will have entered this notch.

The contacts Slice-62a, 6817-4521), 6Ba63 and 6613-63 of the circuit controller are usually referred to as the indication contacts, and their function is to so control signals governing traffic over the switch connected to the switch operating apparatus that these signals will indicate stop unless the switch points occupy their proper extreme positions relative to the stock rails .and are locked in these positions. When, by error, the switch is trailed through, the switch points are displaced at the top an amount whichwould easily operate the circuit controller if the connection of the point detector rod with the switch points could be made at the top of the points. However, for clearance reasons, it is necessary to connect the detector rod to the switch points some distance below the top of the points where, due to the rolling of the points during the trailing, the amount of the movement may not be more than one-half of that occurring at the top; and furthermore, after a train has trailed through the switch, the points will usually spring back toward their original positions a certain amount. As a result, the final displacement of the point detector rod or rods may be very little, if any, more than the displacement which would correspond to a maximum permissible opening of the closed switch point, (which is the setting at which the circuit controller would be adjusted to operate the indication contacts), while the openin of the closed point at the top might be sufficient to be extremely dangerous for subsequent high speed train movements. In order to insure that this dangerous condition will be detected, I provide the circuit controller with latch mechanism for holding the indication contacts in their operated positions after they are once operated by displacement of the switch points until they are released by a maintainer. Thus, even though the switch points spring back toward their proper positions after the train has trailed through the switch, the signals governing trafiic over the switch will continue to displa a restrictive indication until the maintainer releases the latch and permits the contacts of the circuit controller to return to their normal positions. sumed that before the maintainer does this, he will inspect the switch points, and, if damaged, repair them, thus guarding against a dangerous condition due to damaged switch points.

This latch mechanism, as here shown, comprises a latchin finger I05 which cooperates with a latch surface 82d formed on the yoke portion of the contact operating member 82 above the stop shoulder 820. The latch finger I 05 is pivotally sllpported intermediate its ends on a pin I06 mounted in upstanding lugs IIlI provided on the frame 50, and is constantly biased to a latching position by mean of a tension spring I08 stretched between the upper end of the latching finger and an upstanding lug I09 provided on the frame 50. When the contact operating member occupies its normal position in which it is shown in Fig. 2, the latching finger is held in engagement with the side of the contact operating member by means of the spring I08. When, however, the contact operating member is moved to its It is as- 'contact operating position as bya train trailing the switch, the latch spring thenrotates the latching finger into engagement with a stop lug 82c formed on the upper side of the yoke of the contact operating member 82. When in this latter position, the lower end of the latching finger overlies the latch surface 82d and prevent the contact operating member from returning to its normal position in which it is shown in Fig. 2. Thus, it will be seen that once the indication contacts are operated by operation of th oint detector rod D, it will notbe possible for the contact fingers 600. or 60b, as the case may be, to return to their lowermost positions until the latching finger i manually restored to its normal position, even though the switch points spring back to their normal positions in which the notch in the point detector rod aligns with the roller which was previously forced out of the notch to operate the contacts.

The switch operating apparatus further comprises auxiliary contact mechanisms for interrupting the motor circuit whenever the selector lever is moved away from the motor operating position to insure that the motor cannot be operated in a manner to cause injury to a person who is attempting to operate the switch machine by means of the hand lever, as well as for conditioning circuits for indicating at a remote point that the switch movement is in condition for manual operation. As here shown, this auxiliary contact mechanism comprises two flexible contact fingers H5 and HE (see Figs. 1, 2, l and 12) which cooperate with fixed contact members 511 and Ba to form contacts II--II5a and II6-I Ilia, respectively. The flexible contact fingers are supported in the proper positions to cooperate with the fixed contact fingers by means of supporting strips I I1 and I I8 secured to terminal posts I I9 and I20 mounted on an insulating strip I2I. The insulating strip I2! is secured to one side of the circuit controller frame 50 and serves as a support for other terminal posts connected to the previously described

contact fingers

60a and 60b, The fixed contact members 511 and H60, are secured by means of screws I22 and I 23 to supporting members I24 and I25 secured by means of terminal posts I 26 and I2! to the insulating strip I2I. Th fingers are biased by their own resiliency to the positions in which they engage the associated fixed contact members, but are arranged to be at times moved out of engagement with the fixed contact members by means of insulating buttons I28 and I29 provided on upstanding arms I30 and I3I (see Fig. 14) forming part of a compound contact operating lever I32.

The lever I32 is pivoted on a rod I33 mounted at 7 it ends in bosses I34 formed on the sides of the housing I, and is formed with a depending le I35 which is pivotally connected with one end of an operating link I35. The link I36 rests by gravity o a shelf I31 formed in the bottom of the housing I, and is provided with a tapered hole I38 which receives with slight clearance the tapered lower end of an operating arm I39. The arm I39 is secured at its upper end to one end of a rockshaft I40 which extends transversely of the switch machine, and which is journaled intermediate its ends in spaced lugs I4I formed on a supporting bracket I42. The bracket I42, in turn, is secured to what is generally termed a gear box, which gear box is removable from the housing I as aunit, and which supports the shaft 6, the gear wheels I5 and I1 and associated clutch mechanism for selectively connecting these gear wheels with the fact that the only connection between thelever shaft 5. The rockshaft at the end opposite to the arm I39 has pinned thereto a second arm I43 which overlies and cooperates with the arm 35a of the shifter fork 35. A torsion spring I44 surrounds the rockshaft I40 between the lugs MI and constantly biases the rockshaft in a clockwise direction as viewed in Fig. 2 to the position in which a stop screw I45 adjustably mounted in a laterally projecting lug I46 formed on the side of the arm I43 engages the side of the framework of the gear box. The stop screw is so adjusted that the arm I39 will normally be maintained by the torsion spring in the vertical position shown.

With the auxiliary contact mechanism arranged'in this manner, when the selector lever occupies its motor operating position in which it is shown in Fig. 1, the torsion spring holds the arm' I39 in its vertical position, and the parts are so proportioned that under these conditions, the arms I30 and I3I carrying the insulating buttons I28 and I29 will be held in their vertical positions and the buttons I28 and I29 will be out of engagement with the contact fingers H5 and II Ii. It follows, therefore, that when the selector lever occupies its motor operating position, the contacts II5--I I5a and IIIi-I Ilia will be closed. When, however, the selector lever is operated from the motor operating to the hand throw position, the resultant upward movement of the shifter fork 35 will cooperate with the arm I43 to rotate the shaft I40 in a counterclockwise direction, as viewed in Fig. 2, in. opposition to the bias of the spring I44, and this rotation, in turn, will act through the arm I39, link I36 and depending arm I35 to rotate the lever I32 and hence the arms I30 in the same direction. This latter rotation will move the insulating buttons I28 and I29 into engagement with the flexible fingers I I5 and H6 and will thus move these fingers out of engagement with the fixed contact members I I5a and Ba to open the contacts II5-I I5a. and I IBI Ilia. When the selector lever is subsequently restored to the position shown, the spring I44 will return the parts to the positions shown and will permit the contacts I I5I I5a, and I I6-I Ilia to again become closed due to the inherent resiliency of the fingers.

It should be pointed out that while as shown the contacts II5II50; and IIB-iIBa are normally closed, the fixed contact members I I50, and Ba are so constructed that by removing the bolts I22 and I 23 and turning these members over so that the contact buttons carried thereby face upwardly, instead of downwardly, these contacts can be converted from normally closed to normally open contacts which become closed when the selector lever is moved to the hand throw position.

It should also be pointed out that due to the I39 and the link I 35 is that provided by the tapered end of the lever and the tapered hole, the gear box can be removed at any time without the necessity for taking any precautions to disconnect the circuit controller since when the gear box is removed the lever I39 will lift out of the hole I38.

Although I have herein shown and described only one form of railway switch operating apparatus embodying my invention, it is understood that various changes and modifications may 'be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

iZl-Iaving thus described "my invention, what I claim is: a

1. In railway switch operating apparatus of the type in which -I:a {slide bar is moved to an intermediate-position ?prior to the reversal of the switch points and to one 101' the other-jot two extreme positions upon the completion of the movement of the switch :points depending, upon the extreme position to which the-switch points have been moved, the combination .of a camshaft rotatable between two extreme positions response to rotation of :said :slide .abar between its two extreme positions-a contact operating :mem-

fber journa'led ion'sa-id camshaft, two .pivotedpoint detectorlevers 'eachprovided-witha roller a' point "detector rodsecured to the switchi-points to move therewith andprovidedwith-a notch which alig s with the roller carried by the one point detector lever when and only when the switch occupies its one extreme position andwith the other roller when and only when thesswitch occupies its other extreme position, means biasing :said point detector levers in directions tending to cause said rollers to enter said notch, two operating levers journaled on eccentric bushings mounted on said camshaft and operatively connected with .said contact operating merriherandwithsaid two point detector levers, respectively, said bushings being so disposed on said shaft that the roller on said one point detector lever is free :to :enter the notch in said .point detector rod when and only when said slide bar occupies its one extreme position and that the roller "on said other point detector lever is free to enter said notch when and only when said slide bar occupies its -other extreme position, and :a contact controlled by said contact operating member.

2. In railway switch operating apparatus of the type in which :a slide bar is moved to an intermediate position prior to the eversal of the switch points and to one or the other of two .extreme positions upon the completion of the movement of the switch-points depending upon the extreme position to which the switch points have 7 being *so disposed that one lever will occupy one "extreme positionwhen the slide bar and switch points occupy one 'extre'me'position andwill be moved away from "said one position-at all other times and that the other lever will occupy one extreme position when the slide bar and switch points occupy another extreme position and will be moved away from such otherpositi'on at all other times, and a contact controlled by said contact operatingmember. V

3. In railway "switch operating apparatus of the type in which a slide bar 'ismoved to an inher journaled on said camshaft, :twoy'operating -levers journaled :Dn" eccentric bushings mounted on said camshaft :and -operatively connected with said contact operating member and with the switch points, said eccentric bushings being :angularly displaced on the shaft in such man- :ner and the connections with the switch points and contact nperating member being .such that said operating member will be held in one extreme position except When said slide bar occupies "one or the other of its extreme positions and the switch points are displaced from the corresponding extreme position, and a contact controlled by said contact operating member.

:4. In railway switch "operating apparatus nf the type in which a slide barris moved to anintermediate position prior to the reversalrof "the "switch points-and to tone or the other pf two aextreme positionsupon the completion of the movement of the switch points depending upon the extreme position to which-theiswit'ch points have been moved, the combination of a camshaft rotatable between two extreme positions in response to rotation "of said slide bar between its two extremeposi-tionsra contact operating member journaled on said camshaft, two operating levers journaled on eccentric bushings mounted on said camshaftand operatively connected with said contact operating member and withthe switch points, said eccentric bushings being .angularly displaced on the shaft in such "man-- her. and the connections with the switch :poin-ts arid contact operating member being such that said operating member will be held in one extreme position lexcept when said vslide bar :occu-- pies one or the other of itsextreme positions and the switch "points are displaced from the. corre- :sponding extreme position, :a contact controlled by said contact operating member, and means for preventing .said contact/operating member from returning to its one extreme position after it"is "moved away fromsuch extreme position until it is manually-released.

5. In railway switch operating apparatus of the type in which a slide bar is moved to an intermediate position prior to the reversal of the switch points and to one or the other oftwo extreme positions upon the completion of the movement of the switch points depending upon the extreme position to which the switch points have been moved, the combination of a camshaft connected to said slide bar for rotation between two extreme positions in response to movement of said slide bar between its two extreme positions, a first and :asecond cam mounted on said camshaft to rotate therewith, a point detector rod secured to the :switch points to movetherewith and provided with ;a notch, two pivoted point detector levers each provided with a roller :and each biased in a direction which tends to cause the lroller carried thereby to enter said termediate position prior to the reversal 0f the switchpoints and to one or the other of two extreme positions upon the completion of the movement of the switch points depending upon the extremeposition to which the switch points have been moved, thelcombination of a camshaft rotatable between two extreme positions in response to rotation of said slide bar between its two extreme positions, a contact operating memnotch, said notch being so disposed that it will align with the roller on the one lever when and onlywhen the switch occupies its one extreme position and with the roller on the other lever when and only when the switch occupies its other extreme position, a contact operating member 'journaled on said camshaft and provided with third and fourth cams, a first contact controlled by said first and third cams, a second contact controlled by said second and fourth cams, two operating levers journaled on eccentric bushings mounted on said camshaft and operatively connected with said contact operating member and with said two point detector levers, respectively,

said eccentric bushings being so arranged. that the roller on the one pointdetector lever is free to enter the notch in said point detector rod when and only when said slide bar occupies its one extreme position and that the roller on the other point detector lever is free to enter the notch in said point detector rod when and only when said slide bar occupies its other extreme position.

6. In a point detector for switch operating apparatus of the type including a slide bar for looking the switch points in their two extreme positions, a camshaft operatively connected with said slide bar, a pair of bushings mounted on said camshaft and each provided with a portion concentric with respect to said shaft'and a portion eccentric with respect to said shaft, a, U-shaped contact operating member having its arms journaled intermediate their ends on the concentric portions of said bushings and provided at their free ends with open end slots, operating levers journaled on the eccentric portions of said bushings and each provided with a first arm carrying a pin slidably mounted in said slots and with a second arm, apair of pivoted point detector le vers each provided with an-arm operatively connected by means of a link' with the second arm of a corresponding one of said operating levers,

each said point detector lever also being'provided and only when the switch occupies its ther,ex--

treme position, said bushings being disposed on said shaft in such relative positions that the rollers carried by said point detector levers are free to enter the notch in said point detector rod when and only when such notch alignswiththe roller and the slide bar occupies a corresponding locking position, spring means biasing said point detector levers to thepositions in which-said rollers enter said notch, means for limiting the rotation of said contact operating member due to said spring means, and a contact operated in accordance with the position of said contact operating member.

'7. In a point detector forswitch operating apparatus of the type including a slide bar for looking the switch points in their two extreme positions, a camshaft operatively connected with said slide bar, a pair of bushings mounted on said camshaft and each provided with a portion concentric with respect to said shaft and a portion ings and each provided with a first arm carrying a pin slidably mounted in'said slots and with a second arm, a pair of pivoted point detector levers each provided with an arm' operatively connected by means of a link with the second arm of a correspondingone of said operating levers,

each said point detector lever also being provided with a roller, a point detector rod connected with the switch points and provided with a notch which aligns with the roller carried by one point detector lever when and only when the switch occupies one extreme position and with the roller carried by the other point detector leve'rw'hen and only-when the switch occupies-its other ex- "trem'e position,said"bushings being disposed on said shaft in such relative positions that the rollers carried by said point detector levers are free to enter the notch in said point detector rod said-biasing means, first and second camsformed respectively" on the two arms of said contact operating'-member,' third and fourth oams mounted on said camshaft for rotation therewith adjacent the two arms of said contact operating membencontacts controlled by said first and third cams, and other 'contacts'controlled by said second and fourth cams. r

8. In a point'de tect'or for switch operating apparatus of the type including a slide bar for locking the switch 'points'in'their two extreme positions,a camshaft operatively connected with said slide'b'ar, 'a pair of bushings mounted on said camshaftand each provided with-a portion concentric with respect to said shaft and a portion eccentric with respect to said'shaft, a U-shaped contact operating member having its arms journaledi'ntermediate their ends onthe concentric portions of said bushings and provided at their free ends with open'end slots, said contact operatingmemberbeingrotatable between a normal anda contact operating position, operating levers journaled on the eccentric portions of said bushings and each provided with a first arm carrying a pin slidably mounted in said slots and with a second arm, a pair of pivoted point detector levers each provided with an arm operativelyconmated by means of a link with the second arm of a corresponding one of said operating levers,

each said point detector lever alsobeing provided treme position, said bushings being disposed bn said shaft in such relative positions that the rollers carried by said point detector levers are ,free

.to enter thenotch in said point detector rod whe'n and only when such notch aligns with the roller and the slide bar occupies a corresponding locking position, spring means biasing said point detector levers to the positions in which said rollersenter said notch, the parts being so proportioned that said contactoperating member will be rotated to its normal position at all times except when the switch is locked'ineither extreme position and neither roller is within said notch; a latching finger biased to a latching position and effective when saidcontact operating member is moved to its contact operating position to latch said contact operating member in such position until said finger is manually operated to release said contact-operating member, anda contact controlled by said contact operating member.

' HERBERT L. BONE;