US1989128A

US1989128A - Railway switch circuit controller

Info

Publication number: US1989128A
Application number: US651933A
Authority: US
Inventors: Herbert L Bone
Original assignee: Union Switch and Signal Inc
Current assignee: Hitachi Rail STS USA Inc
Priority date: 1933-01-16
Filing date: 1933-01-16
Publication date: 1935-01-29
Anticipated expiration: 1952-01-29

Description

Jan. 29, 1935. I H. L. BONE 1,989,128

RAILWAY SWITCH CIRCUIT CONTROLLER Filed Jan. 16, 1935 5 Sheets-Sheet l INVENTOR Q Q HePbePzLBone N BY QRVTNW HIS A TTORNEY Jan. 29, 1935, H. L. BONE RAILWAY SWITCH CIRCUIT CONTROLLER Filed Jan. 16, 1953 3 Sheets-Sheet 2 ww w: @89 E R0... V. mu w No 0 m WMWA r a a a H Jan. 29, 1935. H E 1,989,128

' RAILWAY SWITCH CIRCUIT CONTROLLER Filed Jan. 16, 1933 5 Sheets-Sheet 3 I y l 80 78 7 95 09 5,5 way INVENTOR Herbam L .60129 BY $11M H16 ATTORNEY Patented Jan, 29, 1935 PATENT QFFZICE RAILWAY SWITCH CIRCUIT CONTROLLER Herbert L. Bone, Swissvale, Pa., assignor to'The Union Switch 1' & Signal Company,

Pal, a corporation of Pennsylvania Application January '16,

v Swissvale,

1933, Serial No.- 651,933

a 9 Claims. (om t-253) 'My invention relates to railway switch'c'ircuit I controllers.

Circuit controllers embodying my invention are particularly suitable for, although in no way limited to, use in connection with spring switches of the type which are provided with a facing point look so constructed that when the switch points occupy their normal positions, the'loeking plunger of the lock will normally occupy a locking .posi- -tion, but that-When a train trails the switchthe locking plunger will be automatically withdrawn from its locking positiontounlock the switch by means mechanically actuated by the train, and that when the movable rails have been returned to their normal positions upon completion of the trailing movement, the locking plunger will be automatically restorted to its locking positionby spring means to relock-the switch.

One object of my invention is to provide means for detecting improper adjustment or operation of the lock in a spring switch of the type described.

'Another object of my invention is to provide a latching mechanism for latching the point detector contacts open until they are'manually released in the event that the switch points fail .to becomeunlocked in the normal manner'while a train is trailing the switch.

Specifically, circuit controllers embodying my invention are an improvement upon the circuit controller described in my copending application ,for. Letters Patent of the United States, Serial .No.v 620,421,.fi1ed July 1, 1932, for Railway switch operating apparatus which has matured into Patent No. 1,976,827, dated October15, 1934.

I will describe one form of circuit controller .embodying my invention, andwill then point out the novel features thereof in claims.

In the accompanying drawings, Fig. l is a top plan view showing a spring switch'A controlled by a switch operating mechanism B provided with a circuit controller E constructed in accordance with my invention. Fig. 2 is an enlarged transverse sectional view of thespring connecting rod C forming part of the apparatus illustrated in Fig. 1. Fig. 3 is an enlarged top plan view of the switch operating mechanism 13 and the circuit controller E shown in Fig. 1, with the various cov ers removed to better illustrate the various details of construction. Figs. 4, 5, 6, 7, and 8 are detail sectional views taken substantially on the lines IVIV, VV, VI-VI, VIIVII, and VIIIVIII of Fig. 3, respectively.

Similar reference characters refer parts ineach of the-several views.

attachedtothe operating rod 9.

to similar an adjustable link 49 with the pistonrod 50' oi a Referring first to Fig. 1, the reference character A designates a railway switch comprising, as usual, two fixed rails l and 1 and twomovable rails 2 and 2 The fixed rails 1- and 1 are-laid on tie plates 3 and are securedto crossties 4 in -When the switch occupies its normal position in which position it is shown in" Fig. 1, the movable rail 2 engages the fixed rail 1, andthe movable rail'2 is spaced a slight distance fromthe-fixed :rail 1 When the switch is reversedihowever, themovable rail 2 'then engages the fixed rail 1 and the movable rail 2 is spaced from the fixed rail 1. Y

' The spring connecting rod C may have any suitable form, but in the well known form-here illustrated, this connecting rod'comprises acylin- 'drical housing 10 having a lateral extension'lO "fastened to the head rod-6 (see Fig. 2). The lower end 10 of the housing 'lo has a smaller diameter than the body of the housing, while the upper end is threaded toreceive a cap 11 having an end l1 similar to the end at 10*. Slidably mounted in the opening in the end 10 is a-sleeve 12 provided with an annular'fiange 12 located within the housing 10,- and similarlymounted in the opening in the end 11 is a sleeve 13' provided with an annular flange 13 which is also located within the housing 10. A spring rod 14 extends through the sleeves l2 and 13 withsu'fficient clearness to permit the rod to slide'freely in the sleeves, and this rod carries a compression spring 15 which engages the sleeves at their annular flanges and urges the sleeves toward the-positions in which the annular flange 12 of the sleeve 12 engages the shoulder formed-on the inside of the housing 10 by the end 10 andthe annularfiange 13 of 'the sleeve 13 engages the shoulder formed on the inside 'of the cap 11 by :the end 11 The spring'rod l-is provided with an annular shoulder 16 for 'attimes engagingthe -'outer end of the sleeve 12 and with a nut 1'7 for at times engaging "the outer end of thesleeve 13. The lower end of the spring rod 14 ispivotally The operation of the spring connecting rod C is well understood and need not, therefore be describedhere.

The head rod 6 is also connected by means of buffing device D. This buffing device may be of any suitable type but, as here shown, this buffing device is similar in all respects to the buffing device shown and described in Letters Patent of the United States, No. 1,869,604, granted to William C. McWhirter on August 2, 1932, for Buifing devices for railway switches and the like. -It is believed, therefore, that for the purposes of the present disclosure the following brief description of the bufling device D will sumce. This bufiing device includes, in addition to the piston rod 50, a cam shaft 51 extending into the case of the device and controlling a valve mechanism not shown. Attached to the outer end of the cam shaft 51 is a crank 52 which is connected by a link 53 with the spring rod 14 of the spring connecting rod C. If, when the movable rails 2 and 2 of the switch A are in their normal positions, as shown in Fig. 1, they are moved to their reverse positions by the mechanism B, the piston rod 50 will be moved into the device, and the cam shaft 51 will be rotated in a clockwise direction, as viewed from'the left in Fig. 1. The construction of the device is such that, under these conditions, the piston rod 50 will be permitted to move with substantially no resistance, and the bufling device will therefore exert practically no retarding action on the rails. Conversely, if the movable rails are moved from their reverse positions to their normal positions by the mechanism B, the piston rod 50 will be moved outwardly and the cam shaft 51 will be rotated in a counterclockwise direction, as viewed from the left in Fig. 1, but due to the construction of the device, no retarding action will again take place. If, however, when the movable rails are in either extreme position, a train trails the switch, the cam shaft 51 will remain stationary, and, under these conditions, the action of the device is such that the movement of the movable rails away from the positions which they previously occupied will be unresisted by the bufling device, but that, when the movable rails are being restored to the positions which they previously occupied, by the spring 15' of the spring connecting rod C, the bufiing device will act to retard this latter movement.

The switch operating mechanism 13 is mounted on one end of a tie strap 18 which is secured to the ties adjacent the outer side of the rail 1, and, as best seen in Figs. 3 and 4, this mechanism, in the form here shown, comprises a main casing 19 provided with a tail-like projection 19 and an auxiliary casing 20 which is secured to the taillike projection 19 of the main casing 19. The upper end of the main casing 19 is closed by a cover 21 and a guard 22, which cover and guard are removably secured to the casing by means of studs 23, while the auxilary casing 20 is closed by a hinged cover 24.

Formed in the main casing 19 is an axially extending rectangular guideway 25 which slidably receives a motion plate 26. The motion plate 26 is provided on its upper face with rack teeth 27, and on its lower face with a cam slot 28, and is adapted to be reciprocated between two extreme positions by means of a handthrow lever 30 fixed to a shaft 31. The shaft 31 is journaled in suitable bearings 32 secured to the casing 19, and has fixed thereto a segment gear 33 which meshes with the rack teeth 27. As best seen in Fig. 3, the cam slot 28 is formed with a portion at each end which is parallel to the direction of movement of the motion plate, and. with an intermediate connecting portion which is disposed at an angle to the direction of movement of the motion plate. Extending into the cam slot 28 and cooperating therewith is a roller 34 which is mounted on a pin 35 secured to an arm 36 forming part of a crank 3'7. The crank 37 is journaled in a vertical bearing 38 provided in the bottom of the casing 19 and has fixed thereto on the underside of the casing, a removable switch operating arm 37 which is pivotally attached to the free end of the operating rod 9.

Reciprocably mounted in the casing 19 directly above the motion plate 26 is a locking device 39 comprising two spaced

parallel side members

39 and 39 connected together at their opposite ends by means of

integral end members

39 and 39 The left-hand end member 39 carries a rectangular locking plunger 39 and is formed with two spaced threaded

holes

39 and 39 while the other end member 39 is provided with three unthreaded holes 39*, 39 and 39 two of which holes, 39 and 39 align, respectively, with the threaded

holes

39 and 39 The locking plunger 39 projects with some clearance into a longitudinally extending rectangular slot 44 provided in the tail-like projection 19 of the casing 19, and cooperates at its inner end with a lock rod L which is slidably mounted in a transverse slot 45 formed in the tail-like projection 19. The lock rod L, in the form here shown, is of standard construction, and comprises two longitudinally

adjustable bars

46 and 47 attached at one end to the front rod 5 of the switch A, and provided with registering notches 48 (see Fig. 5), so disposed that these notches will align with the locking plunger 39 when and only when the switch A occupies the extreme position in which it is shown in Fig. 1. The locking device 39 also comprises two

bolt members

39 and 39 which pass through the

holes

39 and 39 respectively, and are screwed into the threaded

holes

39 and 39 These bolt members also extend with some clearance through holes 40 and 41 formed in lugs 42 and 43 secured to the upper face of the motion plate 26, and surrounding each bolt member-between the associated lug 42 or 43 and the end member 39 is a compressed coil spring 39 which biases the locking device 39 in the direction to cause the locking plunger 39 to enter the notches 48 in the lock rod L.

Vertical displacement of the locking device 39 and the motion plate 26 are prevented by a hold-down member 114 (see Fig. 8) which holddown member is bolted to the side of the casing 19, and which is provided on its underside near its ends with hold-

down surfaces

114 and 114 which are adapted to slidably engage the upper edges of the

side members

39 and 39 respectively, of the locking device 39.

For reasons which will become apparent as the description proceeds, the parts of the locking device 39 are so proportioned that when the motion plate 26 is in its left-hand or normal extreme position as shown in Fig. 1, the biasing spring 39 will tend to drive the locking device to an extreme position which is beyond the desired locking position. The locking device is prevented from moving beyond the desired looking position, under these conditions however, by linkage which connects the locking device with the tie rod 8. As here shown, this linkage includes a plunger bolt 54 which extends with some clearance through the hole 39 in the end imember, 39 and'the head of which-bolt engages the left-hand side of the end 1 member-39 as :viewed in "Figs; 3 and 4. The threaded end 'of the plunger bolt- 39 is adjustably connected by -means or a turnbuckle 55 (see Fig. 1) with one end of a link 56, theopposite "endof whichlink -is pivotally connectedwith the long arm" 57 -of abell crank lever 57. The bell crank-lever 57 is pivotally supportedin'a crank stand 58, and 'has its-short arm 57* pivotally connected-with 'one'end ofan operating'rod 59. "The'o'ther end of the-operating-rod 59 is connected with the previouslydescribed tie rod 8 by means of-a standard switch basket 60. The tie rod S -may be: located at any suitable location, but will-pref- -erably=be located approximately half-way -between the: heel and the point of the switch. "The base 61 of the crank stand 58 is securedboth to a gauge plate 62 and to .the tie strap 18 upon which the mechanism B' is mounted,-and it will be apparent, therefore, that any lossoiadjustmentbetween the parts'due tocreepageoi the 'ties is prevented. The plunger bolt" 54, turn buckle 55, link 56, bell crank lever 57, operating rod 59, spring basket 60, and tierod 8, alsocons'titute meansfor effecting the unlocking of the switch points during a trailin move, as will be made clear presently.

The operation,- as a Whole, of the portion of the apparatus thus far described is as follows: When the hand-throw lever 30 occupies the extremepositionin which it is shown in full lines in Figs; 1

and 3, the motion plate 26 is held in its extreme left-hand or normal position as viewed in Figs. 3 and 4, and the roller 34 on the crank 37 then occupies the right-hand end of the cam slot 28 in the motion plate, so that the crank 13'? is held at the extreme end of its stroke in a clockwise direction, as viewed in Figs. 1 and 3. When the crank 37occupies this extreme position, a force is exerted on the movable rails 2 and 2 of the switch through'the medium of the operating rod 9, spring rod 14, nut 17, sleeve 13, spring 15, housing 10,

and the head rod 6, which force holds the mov- -able-rails in their normal extreme positions in which they are shown in Fig. 1. Whenthemovable rails are in-their normal positions, the notches 48 in the lock rod L align with the locking plunger 39 and the locking device 39 is therefore moved by the biasing springs 39 to its locking position in which the locking plunger partly enters the registering notches 48, thus securely lockingthe switch points in their normal positions.

When it is desired to reverse the switch, the hand-throw lever 30 is rotated from the extreme position in which it is shown in full lines-in Fig.

1, 'to its opposite extreme or dotted line-position. This movement of the lever causes the motion plate 26 to move from its extreme left-hand position, as viewed in Figs. 3 and 4, to its extreme right-hand position. As soon as the motion plate has moved a short distance, the lugs 42 and43 carried thereby engage the left-hand side of the end-member 39 of the locking device 39, and as a result, as the motion plate continues to move, the locking device is moved with the motion plate, thus withdrawing the locking plunger from engagement with the notches-48 in the lock rod L, and hence unlocking the movable rails 2 and 2 The parts are so proportioned that while the locking plunger 39 is being withdrawn from engagement with the notches 48 in the lock rod, the cam slot 28 in the motion plate willcontinue to engage the roller 34 on the crank 37 at that=portion of the slot at its right-hand end which is -parallel t0 the-direction "of movement-of the-niotion plata and'as long as this-portion of the slot is engaging the---roller-,=the crank" 37 will remain stationary. :It 'follows, therefore, that during that portion of themovement'of the motion platewhich isnecessarygtocunlock the movable rails 0f the switohlno force-is exerted onthese rails tending to reverse-them. As soon, however, as this first part :of the movement of the motion plate has .been c'ompleted the-roller 34 is then engaged by the curved-portion ofthe camslot 28 which causes the crank 3-7 to-be rotatedin a counter-clockwise 'directionyasfviewed in'Fig; 3; and as a-result,'the rails are theri' moved to their reverse, positions. 'As previously pointed o-ut,-when the rails are movedtotheir reverse positions by the mechanism ':B, the;piston:rod 50= of the buffing device D is -ll-10V6'd il1l/O the device, and the camshaft 51 is rotated in a clockwise direction, as viewed frorn the left in-Figl 1, but-dueto the construction of this device; thedevice offers substantially-nomesistance tofthe movement of the rails under these conditions. Itishould be' noted-that as long as-the movable :rails remain s'tationa'ry, the plunger bolt 54 remains fixeds0 that during the first part of the movement of the motion plate, the end member 39 ofthe locking-device 39 will move out of .engagement-with the head of the plunger bolt. --As soon" as the -movable rails have started to move, howeverfthe; resultant movement of the tie rod "kl-acting throughth'e switch basket 60, operating rod 59, bell cranklever57 and link 56 causes the plunger bolt tomove inthe same direction as'the motion-"plate is; moving, although the time of motion: and rate of motion of the plunger boltwill hear :no direct relation to the 1 movementf'of the inotion' plate. During'the final movement ofthe motion plate, the portion of the cam slot 28in ther'notion plate at the right-hand end-of the slot which is parallel to'the direction-"of movement of the'motionplate engagesAthe-roller 34; which prevents further rotation of' the crank 37, thus locking the-movable'rails in their reverse positions".

In order to restore the movable rails to their normal positions after they have been reversed as above desoribedythe lever 30 is-restoredto' 'the pos'itionin which it is 'shownin full linesin the "drawing. 'Iheesubsequent movementsofthe parts under these-conditions are just the reverse of "those described above, and it is believed, therefore, that theo-perationof the'apparatus under these conditions, will be readily understood from an inspection-of the drawings-without further de- I scription.

"I will now assume that the parts are in their normalpositions, as'shown in the drawings, and that a train trails the switch. As the leading wheels of the train roll along the 'fixed rail Land the movable rail'2 fthe movable rails 2 and Ware forced over laterally, but, before a sufficient force is developed to oVer-come'the opposing force of the spring 15 of the spring connecting rod'C and cause the point of the movable rail2 to move out of engagement-with'fixed rail 1, the movable rails beingso-mewhat'resilientbecome bent, so that, with the usual standard split switch, the tie rod 8 isrnoved upwarclly; as viewed in Fig. 1, threequarters of an: inchoramore. This movement of the tie ro-dacting thro-uglirthesvn'tch basket 60,. operating'rod 59,, bell-crank lever- 57, link 56, and plungerbolt -59 moves the locking device 39in (opposition to .theubias of :thesprings 39 a :suiii- :cienh amount: to withdraw. the lo'ckingiplunger: 39 zcompletelyiout-of engagement: with .thexnotches 48 in the lock rod L, thus unlocking the switch. As a result, when the leading wheels have reached the position in which a sufi'icient force is developed to cause the point of the movable rail 2 to move out of engagement with the fixed rail 1, the switch points will be unlocked, and the points will therefore be forced open by the wheels in exactly the same manner as would be the case if no facing point lock were provided, and the buffing' device D will perform its usual functionof preventing the movable rails from snapping back after the passage of each wheel through them. When the train which is trailing the switch has completely passed the switch, the movable rails will slowly return to their normal positions under the bias of the spring 15 of the spring connecting rod C, and against the retarding force of the buffing device D. During this return movement of the movable rails there will be no deflection of these rails, and the locking plunger 39 will be moved into engagement with the lock rod L before the movable rails have reached their full normal positions in which the'lock rod is in the proper position for the notches 48-tl1erein to receive the locking plunger. The spring 39 will therefore become compressed, and will urge the locking plunger 39 into engagement with the side of the lock rod, until the notches 48 move into alignment with the locking plunger, at which time the energy stored in the compressed springs 39 will force the locking plunger into place in the notches, thus restoring the switch to its normal locked condition. If the notches 48 in the lock rod should not come into alignment with the locking plunger, a suitable indication of this fact will be given by means of a circuit controller E embodying my present invention which circuit controller I will describe presently.

During a facing point move, there is no lateral thrust on the movable rails corresponding to, or commensurate with, that which occurs during a trailing movement and what lateral thrust there is will be in the direction to permit the springs 39 to force the locking plunger further into the notches 48 in the lock rod L.

It will be noted that when the parts are in their normal positions as shown in Fig. 1, the reaction of the biasing springs 39 is transmitted through the rack teeth 27 and segment gear 33 to the switch-throw lever 30, which tends to raise this lever. However, this lever is so designed that it has sufiicient weight to resist and overcome this reaction. Furthermore, if it is undesirable for any reason to provide the lever 30 with sufficient weight to overcome the reaction of the springs 39, this lever may be held down by a conventional gravity lever latch stand, two of which stands are indicated at 91 in Fig. 1.

It will also be noted that when the parts are in their normal position as shown in Fig. 1, since the springs 39 tend to drive the locking device to an extreme position which is beyond its normal locking position, but are prevented from doing so by the linkage connecting the locking device with the tie rod 8, these springs will cause a force to be exerted on the movable rails at the point where the tie rod 8 is connected with the rails, and this force which, due to the mechanical advantage afforded by the bell crank lever 57, is relatively large, aids the force exerted by the spring 15 of the spring connecting rod in restoring the movable rails to their proper positions after the switch has been trailed, or after the switch has been operated to its normal position by the hand lever. In most switch layouts when the movable rails are in their proper normal positions,

the entire length of the movable rail 2 between the tip of the rail and the point where the tie rod 8 is connected with the rail, will be in contact with the stock rail 1, and in those switch layouts where this is not the case, fixed stops will usually be provided for the movable rail 2 at the point where the tie rod 8 is connected with this rail. It will be seen therefore, that with apparatus embodying my invention, when the movable rails are in their proper normal positions, the movable rail 2 at the point at which the tie rod 8 is attached to this rail will be constantly urged into engagement with a definite stop by a relatively large force, thus insuring that as long as the linkage connecting the tie rod 8 with the locking device is in proper adjustment, and the lock rod L is in proper working order, the locking device will always to return to its proper locking position after the switch has been trailed, and will thereafter remain in its proper locking position until the switch is again trailed, or until the switch is moved away from its normal position by the mechanism B.

The circuit controller E referred to herein before is located wholly within the casing 20, and in the form here shown, comprises a rocker arm 66 pivotally supported intermediate its ends on a pin 67 (see Fig. 5) secured within a pair of spaced lugs 68 extending upwardly from the bottom of the casing 20. The rocker arm 66 is disposed directly above the locking plunger 39 and is provided with a cam slot 69 which cooperates with a roller 70 mounted in the upper end of a U- shaped bracket 71. wardly with considerable clearance through a longitudinal slot provided in the bottom of the easing 20 and is secured at its lower end to the locking plunger 39 It will be seen, therefore, that the roller '70 will be reciprocated in response to reciprocation of the locking plunger 39 The rocker arm 66 is also provided with a cam face 74 which joins the cam slot 69 at the right-hand end of the slot, and which also cooperates with the roller 70 in a manner which will be described hereinafter.

The inner end of the cam slot 69 is radially disposed with respect to the pivotal axis of the rocker arm 66, but the outer end of this cam slot is provided with an offset portion which extends above the rest of the slot. The radius of curvature of this offset portion is only a little larger than the radius of curvature of the roller '70, and the parts are so proportioned that there will be only a small amount of clearance between the roller and the top and bottom of the cam slot in any position of the roller within the slot. The parts are further so proportioned that when the locking plunger 39 occupies its normal locking position, the roller 70 will engage the cam slot at the central part of the offset portion. It will be apparent, therefore, that when the switch is properly locked in its normal extreme position, the rocker arm 66 will have been positively rotated in a clockwise direction to an extreme position which I shall term its normal extreme po-- sition. If, however, the locking plunger 39 is moved beyond its normal locking position by the biasing springs 39 for any reason, such for example as would be the case if excess lost motion developed in the linkage connecting the locking device 39 with the tie rod 8, or if the parts were improperly adjusted, the roller 70 would be forced out of the offset portion of the cam slot, and into the radial portion, which would rotate the rocker The bracket 71 extends downmember 81-.

arm in a counter-clockwise direction from its'nor mal extreme position'to another extreme positionl, Furthermore, when the locking plunger? 39 i is withdrawn from the notches'48 in'the lock rod L, theroller 70'wil1 likewisebe forced out of theoft setportion-of the cam slot, but underthese conchtions it will move into engagement with the cam face '74:," thus rotating the "rocker arm from its: normal extremeposition to-its counter-clockwise extreme position. It should be'notedthat, dueto' the relatively small radius of curvature ofthe offset portion-f the camslot', this latter rotationof the rocker arm will take place before the lock': ing-plunger 39 has beenmove'd fa'rl'enough'to clear the notches inthe lock rod; The cam 'face: '74 isiso designedand the parts" are soproportioned that after the roller '70 has moved into errgagement withthe cam'iace 74:;I1Uflllth8l rota-- tion of the rocker arm will take-"place "untilthe locking plunger 39 is'subsequently restoredto-its normal locking position, at" which time the roller: 70 will engage the lower face 69% of the-cam s1ot 69 and will positively restore the rocker: arm to its normal extreme position. I

Pivotally attached to the left-hand end-of. the rockerarm 66is a contact operating mem'ber YE. This contact operating member" is mountedvto move vertically on studs '76 which project'upe wardly from the-bottom of the 'casing -20, andv which pass freely throug-hholes "75 inthe operate ing member; Secured to the upper side ofthe operating member 75 are two superposed insulate ing" blocks 78 and79 between which are clamped the free ends of'a plurality of flexible contact fingers 80, here shown as four in number. Each Contact finger 80-cooperates-withan associated" contact member 81t0 form a plunger lock contact 80-8l. Each contact finger SO 'and'theassO- ciated contact member .81. are clampedto the opposite sides of an insulating block 82 by means of terminal posts 83 and-84;--ancl the insulatin'gr block 82, in turn; issupported on lugs-85'projectv ing inwardly: from the sides of the housing 20.: Each terminal post 84 is electrically connected: with the associated contact member 81,- -but-is in sulatedfrom the associated contact finger 80as will beapparent from an inspection of thedraw ing, ,while each terminal "post- 83-is insulated from? both the associated'contact finger 80"and contact The parts are so: proportioned that: when the rocker arm'66 occupies its normal ex'-- treme position in which it is shown in the draw-- ing. each-plunger lock contact 80-"-81-wil1' be closed, but that, when the-rocker'arm is rotated to its other extreme position, each contact30-8l will then become opened. It will be :apparent; thereforathat the plunger lock contactswill be: closed when and only when the-locking plunger: 39 -occupiesits normal locking position,

Associated with each plunger lock contact 8081 is a point detector'contact comprisinga flexible contact. finger 86 which cooperates with a fixed contactmem'ber- 87-. Each contact finger: 861 is fastened at one endjto. a conductingstrip 88', the-other endof which'stripis clamped against the fixed end of 'theassociated finger 80- to: makeielectrical contact therewith; :While-each' contact'member 87 is secured to, and electricallyconnected with, the associated-terminalpost 83.

Pivotally mounted below-the contact fin'gers86 is? a second contact operating-member s (see- Figs 5 and 6)"carryinga rolIer-QO Wh-ich at times enters a notch 91 in a point detector rod 63; The :point detector rod 63 is slidably mounted in the casing- 20 and as shown in Fig.1 is'attachedpby means:

and 'areproperly locked in these positions.

of a link-6e anda bolt member-65 to themovable rail 2 of the switch A-in the usual and well-known manner. The operatingmember'SQ also carries an insulating strip 92which cooperates with the movablecontact. fingers 86 in such manner that whentlie roller"90 is Within the notch91 in the pointidetector'rod 63, the insulating strip '92 will be: clear of themovable contact fingers 86, so that thelcontacts 86-8'7 will then beclosed, but that-, when theroller QO'is forced out of the notch- 9l, this strip will engage the underside of the fingers 86 and raise them to the positions in which theytare' out of.-enga'gement with the associated fixed contact members 87, thus opening the contacts 86 -87. The notch 91 in the point detector ro'd' fia is so'l'disposedand the parts are so proportioned that the roller 90 will enter the notch 91 when and only when the movable rails 2 and 2- of'lithe switchiA occupy their normal extreme positions; and the rail '2 is in proper engagement with the fix'ed rail 1.

As is wellunderstood, "the contacts of a circuit controller of the type described are utilized to controlsignals governin'g traflic over the switch; and their primary purpose is to cause the signal to indicateflstopi unless-the switch points occupy their proper positions relative to the fixed'rails With the portionot the circuit controller thus far described; thesecontacts will adequately do this inall instances' where the apparatus is in proper working order. However, if due to some failure of the operatingmechanism', the lockingplu'nger 39 does-not become completely withdrawn from thenotches48 in-the lock rod. L in the normal manner while a train is tr'ailing the-switch, a danger ous con'dition might possibly exist, because under these-conditions; while the switch points will be displaced at the top an amount which would easily operate-the pointdetector contacts of the circuit controller if the detectorrod could be-connected wi-th the points atfithe top" of-the points, it is necessary for clearancareasons to connect the: detector rod to the switch points some distance below the top -'of the points; whera due to the" rolling of- 1 the zpoints :during the trailing, the amountof the -mo'vem'ent may not be more than one-half of that occurring at the top of the points and fur'thermore', after a train 'has trailed the switch;- the points will usually. spring back "-toward-their 'original t-positionsa certain amount. As-a :result, thefinal displacement of the' point detectorrod-mayibe very little, if any, more than the displacement which would correspond to 'a.

maximum permissible I opening of the closed switch po'int;=which isthe setting at which the point detector contacts becomeopened, while'the openingoflthe closed pointiat the'top might be suffi'cientto be extremely dangerous forsubsequent high speed: train movements: In 'order to insure that this dangerous'condition will be de-- te'cted'gI provid'e latching mechanism so constructed that if-the switch fails to become unlocked while 1 the train is trailingthe switch, this latch in'g mechanismwill retain theindication contacts in 'th'eiroperated positions until they are subsequently releas'ed by -a maintainerh even'thoughxthe switch points'spring back toward theiraproper positions after 1 the train has trailed throughthe'switch,.the signals governing traffic over'rthe switchtwill' continuexto display a restrictive 'indicationwuntil the maintainer releasesr the-contacts of the circuit controller andpermits them .toIreturn-to their normal positions; It is. assumed that before the maintainer-does this,

he will inspect the switch points, and, if damaged, repair them, thus guarding againsta dangerous condition due to damaged switch parts.

Referring now again to Figs. 3 and 4, the latching mechanism just referred to comprises a latch arm 107 which is secured at its left-hand end to the contact operating member 89, and which extends toward the right from the pivotal axis of this operating member. A latch dog 106 is provided on the extreme right-hand end of the latch arm 107, and cooperating with this latch dog is a latch catch 100 having a screw threaded upper portion 100 which is adjustably screwed through a tapped hole 95 in a latching member 95. The latch catch is also provided with a rectangular latch head 100 having its opposite sides cut away to form two notches 104 and 105, and the latch catch is adapted to be locked, by means of a lock washer 101 and a jam nut 102 provided on the threaded portion 100 above the latching member 95, in an adjusted position in which either the side of the latch head 100 containing the notch 104, or the opposite side, faces the latch dog. To facilitate adjusting the latching member, the upper end of the threaded portion 100 is provided with a saw kerf 100 for the reception of a screw driver.

The latching member 95 extends transversely of the casing 20 directly above the left-hand end of the rocker arm 66, and is pivotally supported at its ends on trunnion screws 96 which are adjustably mounted in bosses 97 formed in theside walls of the casing 20. A substantially horizontal cam arm 108 extends toward the right from the latching member 95 and is provided adjacent its righthand end with two converging downwardly extending cam faces 111 and 112 which cooperate, under certain conditions later to be described, with the roller carried by the locking plunger 39 The cam arm 108 also serves to overbalance the latching member, so that the latching member tends to constantly rotate in a clockwise direction about the trunnion screws.

The latching member 95 is further provided with 2. depending leg 109 (see Fig. 7) carrying a horizontal latching foot 110 which extends underneath the rocker arm 66. The latching foot 110 coacts with the lower end of a latching plunger 113 which extends upwardly throughi concentric holes 114 and 115 (see Fig. 5) formed in an upwardly projecting portion provided in the left-hand end of the rocker arm 66. The hole 114 is made considerably larger in diameter than the hole 115 since hole 114 is adapted for the reception of a coil spring 116 which surrounds the latching plunger 113 between the upper end of the hole 114 and a guide 11'! which is secured to the plunger. The spring 116 biasesthe latching plunger to a lowermost position in which it is stopped by a nut 118 screwed onto the upper end of the latching plunger above the hole 115.

The parts of the latching mechanism are so proportioned, and. the latch catch 100 is so adjusted that when the roller on the contact operating member 89 is within the notch 91 in the point detector rod 63, and the locking plunger 39 is within the notches 48 in the locking rod L, as shown in the drawings, the latch head 100 of the latch catch 100 will engage the end of the latching dog 106 on the latch arm 107 just above the notch 104, and will thus prevent the latching member from rotating in a clockwise direction past the position in which it is shown in the drawings. In order to prevent vibration and consequently wear-between the latch catch and the latching dog due to the passage of trains over the switch when the parts are in these positions, a spring 119 is stretched between a depending lug 120 on the operating member 89, and a lug 121 formed on the-side of the leg 109 of the latch member. It will be seen that this spring increases the normal tendencyof the latching member to rotate in a clockwise direction, and the tendency of the operating member 89 to rotate in a counter-clockwise direction, so that the latch catch is normally held firmly against the end of the latching dog, and the latching dog is prevented from vibrating up and down.

In explaining the operation of the circuit controller as a whole, I will first assume that the switch points are locked in their normal positions and that a train trails the switch. I will also assume that while the train is trailing the switch, the locking mechanism functions in the manner previously described so that the locking plunger 39 becomes fully withdrawn from the notches 48 in the lock rod L and unlocks the switch points before the switch points are forced open by the wheels of the train, and that after the train has completely trailed the switch and the switch points have been returned to their normal positions by the spring 15 of the spring connecting rod C, the locking plunger is restored to its normal locking position to relock the switch points in their normal positions. tions, as soon as the locking plunger 39 starts to move toward its unlocking position due to engagement of the wheels of the train with the movable rails of the switch, roller 70 will rotate rocker arm 66 in a counter-clockwise direction from its normal extreme position to its other extreme position in the manner previously described, and this rotation of the rocker arm will open the plunger lock contacts. This rotation of the rocker arm will also cause the latching plunger 113 to move into engagement with the upper side of the latching foot 110, thus forcing the latching plunger upwardly in opposition to the bias of spring 116. When the locking plunger 39 reaches the position where it is just clear of the lock rod L, roller '70 will move into engagement with cam face 111 of cam arm 108, and as the latching plunger continues its movement, cam. arm 108 will be rotated in a counter-clockwise direction by the roller 70. This rotation of the cam arm, in turn, will rotate the latching member to a position in which the latch catch is out of engagement with latching dog 106, and in which the latching foot is clear of the right-hand side of the latching plunger 118. As soon as the latching foot 110 clears the latching plunger, the spring 113 will force the latching plunger to its lowermost position, and as a result, when the roller 70 has moved completely past the cam face 111 on the cam arm 108, the latching plunger 113 will engage the latching foot 110 at the left-hand side of the latching foot and will thus hold the latching member 95 substantially in the extreme position to which it was previously moved by the roller 70. When the switch points are next forced open by the trailing train, the roller 90 on the contact member 89 will be forced out of the notch 91 in the point detector rod, which action will rotate the operating member 89 to the position in which the point detector contacts 8687 become opened. The parts will then remain in the positions which they then occupy until the train has completely trailed the switch and the switch points have started to return to their normal positions. When this hap- Under these condipens, -the locking plunger will, of course, start to. return to-its normal locking position, andduringthe first part of this return movement, the roller '70 will engage the cam face 112 on the cam-arm. 108, andwill raise the cam arm- 108 slightly, so

that the latching member 95 will be rotated through a small anglein a counter-clockwise direction from the position where it is stopped by engagement of the latching plunger 113 with the left-hand side of the latching foot 110. As soon,

however, as the roller '70 has moved past the cam which it is shown in the drawings.

face ,112, the latching member will return by gravity to its latched'position. Shortly after the roller passes the cam face 112, the endpoint detector contacts will close and the latch arm'lfl'lwillbe restored to its normal position in When the switch points reach their full normal position,

the notches 48 in the lock rod L will then align with the locking plunger and will allow the lock ing plunger to snap into its normal lockingposition under thev action of the biasing springs 39 in the manner previously described. As the locking plunger thus completes its return stroke, roller 70 will'engage cam surface 69 of cam slot 69' in rocker arm 66, and will thus rotate the rocker arm to its normal position. This rotation of the rocker arm, in turn, will cause the plunger lock contacts -81 to close, and will also raise thelocking plunger 113 to the positioninwhich it is out of engagement with the latching foot 110.- As soon as the latching plunger has moved out of engagement with the latch foot, the latch-,

ingmember will return, under the influence of gravity and the'bias of the spring 119, to the position in which the latch catch engages the end of the latching dog 106, and all parts of the circuit controller will then be restored to their normal positions in which-they are shown in the drawings.

Where the parts are in the positions in'which they are shown in the drawings,- and the switch is operated to its reverse position by means of the hand throw lever 30,- the operation of the circuit controller will be similar to that just described for a trailing movement up to the point where V the switch points start to return to their normal positions.

Likewise, after theswitch' points have been movedto their reverse positions by the"hand-' throw lever, and the hand-throw lever is subsequently operated to restore the switchpo-ints 'to their normal positions, the operation of the circuitcontroller will be similar to that "just described fora trailing movement from the point where the switch points have started to'return to their normal positions.

I will now assume that a train trails the switch,

I and'that the mechanism is so far out of adjustment that the locking plunger remains in its normal "locking position during the entire time the train is trailing the switch. Under these conditions, the plunger lock contacts 80 -81 will remain closed, but due to the extreme forces which" are exerted on the switch points by the trailing train, the point detector rod will be moved upwardly as viewedin Fig. 2 far enough to cause the roller 90on the contact operating member -89 to move out of thenotch'elin. the lock rod L. As a-result, the operatingmember 89 will be rotated to-the position in which the point detector contacts become opened, andin which the latch dog 106 onthe latch arm 107' alignswiththe notch 104 in the latch catch-100. Thelatchingmember95 will therefore now rotate, due to its bias, to the position-in which the latch dog- 106 enters the notch 104 in the latch. catch.100.. It will be apparent from an'inspectionof the drawings that when the latch dog 106 has once entered the notch 104 in the latch catch l00, the operating member 89 will be held in the position in which the point detector contacts are open until the latch catch is subsequently moved outqof engagement with the latch dog even if the pointdetector; rod subsequently returns to'the positionrin' which the notch 91 aligns with the roller 90.- It follows that in order to releasethe operating member and permit the point detector contacts-tobecome-closedafter they have once been opened in'the manner just described, ityis necessary to'restore-the latching member 95 to itsnormal position in which it is shown in the drawings.- This may be-done either by removing the hinged cover 24 from the casing 20 and raising 111118103111. arm, 108' manually, or by throwing theswitch movement by hand to its reverse position,xin which latter case,.roller 70 will raise the cam arm and thus release the, operating member;. Whenthe point detector contacts are .released by.. thro.wing,.the:switch movement to its reverse position by' hand, if the switch points haveibeen distorted' at all by. the trailing'train,

the :locking plunger willnot reenter the "lock-rod thatqthe locking plunger is partly withdrawn from r engagement with the notches 48 in the lock rod Lflbut is not moved far enough to clear the notches, the apparatus will still operate to latch the point detector contacts 'open until they are subsequently manually released.- Under these conditions-theoperation of the mechanism will bethesame as that just describedwith the exception that the, rocker arm 66' will now be rotated from its normal extreme position to its other extreme position, so that the latching plungerllB will be moved upwardly by .engage-- mentfof the latching plunger with the'latching foot-;1-10'. -'This engagement of the latching" plunger with the. latching foot 110 will not pre vent-the latching device from rotating to its latching-i position, as might appear on firstthought, but" on 'the-contrary, the end of the latching plunger andthe top of the latching footare disposed at such an angle as to tend to urge the latching member 95 toward its latching position. Itwill be seen,- therefore, that when the switch points are forced open, thus rotating the operatingmember. 39in a clockwise direction to the position in which the point detector contacts are forced .open, the latching member .95 will:be= rotated to the position in which the latch dog 106 enters the'notch 104 in exactly the same manner as it was rotated when the plunger remained in its normallatching position. When the latching member h as beenrotated to the po sition in which the latch dog 106 enters the notch 104 in the latch catch 100, the point detector contacts will then be held open until the latching member is subsequently restored to its normal position in the manner previously described.

Although I have herein shown and described only one form of circuit controllers 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.

Having thus described my invention, what I claim is:

1. In combination, a spring switch, a lock rod connected with the switch and provided with a notch, a locking plunger biased to a position in which it will enter the notch in said lock rod when and only when the switch occupies one extreme position, means for at times withdrawing said locking plunger from said notch to unlock said switch, a contact, means for operating said contact when said switch is moved away from said one extreme position, and means for latching said contact in its operated position if and only if the movement of the contact to its operated position is due to the switch being moved away from said one extreme position by a train trailing the switch while the switch is locked in said one extreme position.

2. In combination, a spring switch, a lock rod connected with the switch points to move therewith and provided with a notch, a locking plunger, means for at times moving said locking plunger into the notch in said lock rod to lock the switch points in one extreme position and for at other times withdrawing said locking plunger from said notch to unlock the switch points, a normally closed contact, means effective if the switch points are moved away from said one position when said locking plunger is within said notch for latching said contact open, and means effective upon withdrawal of said locking plunger from the notch in said lock rod after said contact has been latched open for unlatching said contact.

3. In combination, a spring switch, a lock rod connected to the switch points to move therewith, a locking plunger movable between a locking and an unlocking position and effective when in its locking position for engaging said lock rod to lock said switch in its normal position, means-for moving said locking plunger between its locking and unlocking positions, a contact operating member movable between two positions and biased to one position, means for moving said contact operating member from its one position to its other position whenever said switch occupies any position but its normal position, a contact controlled by said contact operating member, and means for latching said contact operating member in its other position if said contact opcrating member is moved-to its other position when said locking plunger occupies its locking position.

4. In combination, a spring switch, a lock rod connected to the switch points to move therewith, a locking plunger movable between a looking and an unlocking position and effective when in its locking position for engaging said lock rod to lock said switch in its normal position, means for moving said locking plunger between its.

locking and unlocking positions, a contact operating member movable between two positions and biased to one position, means for moving said contact operating member from its one 130 sition to its other position whenever said switch occupies any position but its normal position, a contact controlled by said contact operating member, means for at times latching said contact operating member in its other position when said contact operating member is moved to its other position, and means for rendering said latching means inefiective when said locking plunger occupies its locking position.

5. In combination, a spring switch, a lock rod connected to the switch points to move therewith and provided with a notch, a locking plunger movable into and out of engagement with said notch when and only when the switch occupies its extreme normal position, means for moving said locking plunger into and out of engagement with said notch, a contact operating member movable between two positions and biased to one position, means for moving said contact operating member from its one position to its other position whenever said switch occupies any position but its normal position, a contact controlled by said contact operating member, means for at times latching said contact operating member in its other position, and means for rendering said latching means ineffective except when said looking plunger is in engagement with said notch in said lock rod.

6. In combination, a spring switch, a lock rod connected with the switch points to move therewith and provided with a notch, a locking plunger, means effective when said switch occupies its normal position for biasing said locking plunger to a locking position in which it enters the notch in said lock rod, means for at times moving said locking plunger to an'unlocking position in which the plunger is withdrawn from the notch in said lock rod, a pivoted contact operating member biased to one position and provided with a roller, a point detector rod connected with the normally closed switch point and provided with a notch which is adapted to receive said roller when and only when said switch occupies its normal position, a contact controlled by said contact operating member, and latching mechanism controlled in part by said locking plunger and cooperating with said contact operating member in such manner that if said roller is forced out of the notch in said point detector rod while said locking plunger is within the notch in said lock rod said contact operating member will subsequently be held in the position in which the roller is out of the notch in the point detector rod until the latching mechanism is operated to release the contact operating member.

7. In combination, a spring switch, a lock rod connected to the switch pointsto move therewith and provided with a notch, a locking plunger movable into and out of engagement with said notch when and only when the notch occupies its extreme normal position, means for moving said locking plunger into and out of engagement with said notch, a contact operating member movable between two positions and biased to one position, means for moving said contact operating member from its one position to its other position whenever said switch occupies any position but its normal position, a contact controlled by said contact operating member, a latch arm secured to said contact operating member and provided with a latch dog, a latch catch biased to one position and movable to said one position when and only when said operating member connected to the switch points to move therewith and provided with a notch, a locking plunger movable into and out of engagement with said notch when and only when the switch occupies its extreme normal position, means for moving said locking plunger into and out of engagement with said notch, a contact operating member movable between two positions and biased to one position, means for moving said contact operating member from its one position to its other position whenever said switch occupies any position but its normal position, a contact controlled by said contact operating member, a latch arm secured to said contact operating member and provided with a latch dog, a pivoted latching member provided with a depending latch catch having a latch head containing a notch, means for biasing said latching member to such a position that when said contact operating member is moved to its other position said notch will receive said latch dog and latch said contact operating member in its other position, and means controlled by said locking plunger for rotating said latching member away from the position to which it is biased whenever said locking plunger is withdrawn from the notch in said lock rod.

9. In combination, a spring switch, a lock rod connected wlth the switch points to move therewith and provided with a notch, a locking plunger adapted to enter the notch in said lock rod when and only when the switch occupies its normal extreme position, said locking plunger being movable within said notch to an extreme position which is beyond its normal locking position, means for moving said locking plunger into and out of engagement with said notch, a roller secured to said locking plunger, a pivoted rocker arm provided with a cam slot which receives said roller, said cam slot being so designed that when said locking plunger occupies its locking position said rocker arm will be rotated to one extreme position but that if said locking plunger is moved beyond, or is withdrawn from, its looking position said rocker arm will be rotated to another extreme position, a plunger lock contact operated by said rocker arm, a point detector rod provided with a notch, a contact operating mem-- ber provided with a roller which aligns with the notch ,in said point detector rod when and only when the switch occupies its normal extreme position, said contact operating member being biased to a position in which the associated roller will enter the notch in said point detector rod when this roller aligns with this notch, a contact operated by said contact operating member, a pivoted latching member, a cam arm secured to said latching member and biasing said latching member to a latching position, said cam arm being provided with cam faces which cooperate with the roller secured to said locking plunger to rotate said latching member to a second position when said locking plunger'is withdrawn from the notch in said lock rod, a depending leg on said latching member provided with a latching foot which extends underneath said rocker arm, a latching plunger mounted in said rocker arm and biased to one position and cooperating at its lower end with said latching foot in such manner that if said latching member is moved to its second position when said rocker arm occupies its other extreme position said latching plunger will engage said latching foot and hold said latching member in its second position until said rocker arm is subsequently returned to its one extreme position, a latch arm secured to said contact operating member and provided with a latch dog, and a latch catch secured to said latching member and provided with a latch head containing a notch which is adapted to receive said latch dog when and only when said contact operating member occupies the position in which said roller is out of the notch in said point detector rod and said latching member is rotated to its latching position, the parts being so proportioned that when said notch is receiving said latch dog said contact operating member will be held in the position in which said roller is out of the notch in said lock rod.

HERBERT L. BONE.