US2365800A - Railway track switch operating apparatus - Google Patents

Description

DecrZG, 1944. H. BONE 2,365,800

RAILWAY TRACK sw n'cn OPERATING APPARATUS Filed April 50, 1945 s Sheets-Sheet 1 INVENTOR BY QJZF ZM H11 ATTORNEY Dec. 26, 1944. H. L. BONE RAILWAY TRACK SWITCH OPERATING APPARATUS Filed April 30, 1943 -5 Sheets-Sheet 3 mm an aw wm m H M \M R w \m T,

m QMN v v m u Mm 4 mww Q g Q it m Wu P mm \R Q Patented Dec. 26, 1944 RAILWAY TRACK SWITCH OPERATING APPARATUS Herbert L. Bone, Forest Hills, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application April 30', 1943, Serial No. 485,120

16 Claims.

My invention relates to railway track switch operating apparatus and has particular relation to apparatus for operating switches of the type which are adapted to be trailed. More particularly, my invention relates to novel and improved means efiective when a train trails a switch for shifting the points completely to and holding them in their trailed positions until the train clears the switch.

Track; switches of the type adapted to be trailed ordinarily incorporate a spring which acts between the switch operating rod and the switch points to bias the points to a position corresponding to the position of the operating mechanism with which the operating rod is connected. In such a switch, the tips of the movable switch points are subjected to severe abrasive wear each time they are trailed because all trailing wheels must drive the points to their trailed positions by overcoming the biasing spring force, which force of course increases in value as the spring is compressed due to the points being forced to their trailed positions. The energy stored in the spring is effective to restore the points to their normal positions between trucks and will do so unless some restraining means, such as-an oil bufier, is provided to prevent or check the rapid return of the points to their original positions. The use of thebuiier does not, however, eliminate the abrasive wear on the tips of. the switch points, and if the train should stop with a car bridging the switch, the bufier might permit the points to return to their original positions. This would cause derailment if the train should back up because the wheels which have passed-the points i will take the main track whereas the other wheels are on the siding.

Various means have been proposed to obviate the abrasive action on the switch points when trailed, and to permit backing up movements over a trailed switch. One such scheme involves the use of a toggle spring switch movement which permits trailing movement and in which the points when trailed are held in their trailed positions until returned to their original positions by hand or power. Another scheme shown, for example, in my United States PatentNoE 2,115,901 granted May 3, 1938, for Railway switch operating apparatus, involves a toggle "spring ar rangement in which an electrically controlled latch holds the points in the trailed position until the switch is vacated.

In view of the foregoing and other important vention to provide novel and improved railway track switch operating apparatus incorporating sition, a portion of the biasing means will become effective to urge-the points to their other extreme position and hold them in such other position until the train has completely passed the considerations, it is an object of my present inmeans for biasing the movable points of a switch to either 'of two extreme positions in such a manner that when a train trails the switch and discondition the other spring biased members to switch, whereupon the biasing means will again become effective to bias the points to their original positions.

Another object is the provision, in a switch operating mechanism, of novel and improved biasing means which permits trailing movements.

An additional object is the provision, in a railway track switch operating mechanism, of novel and impreved biasing means using cam motions and a latch device arranged to permit trailing movements.

A further object is to provide a novel an improved biasing means, in a railwaytrack switch operating mechanism; arranged to respond to arelatively short head rod travel when a switch is being trailed.

Another object is to provide a novel and improved biasing means, for use with a railway track switch operating mechanism, arranged to be operated in response to relatively low forces when a train trails a switch.

The above-mentioned and other important objects and characteristic features of my invention which will become readily apparent from the following description, are attained in accordance with the invention by interposing between the movable points of a track switch and the operating mechanism forthe switch, a mechanism com prising a firstmember operatively connected with the points and a second member operatively connected with the switch operating mechanism. The first member is provided with cammed surfaces which cooperate with spring biased members operatively connected with-the second member and which biased members include some which constantly bias theswitch points to their operated'positions and others which initially bias the points to their operated positions but which function when the switch is trailed to operate the points to their trailed positions. These other spring biased members are controlled by a latch device and alatch. linkage effective at times to hold the points in their trailed positions and at other times to release such members and permit the first-mentioned members to operate the points to their original operated positions.

I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a top .plan view showing a switch A provided with one form of a railway track switch operating mechanism embodying my invention. Fig. 2 is a top places the points from their biased extreme po- 0 pe t app a embodying y ention view showing on an enlarged" scale the switch I represented in Fig. 1, with the cover l5 and a portion of the apparatus being removed to show the arrangement of the parts. Fig. 3 is a, side elevational view of the operating mechanism shown in Fig. 2, with a portion of housing l4 being cut away in order to show the relationship views, similar reference characters refer to similar parts.

Referring first to Fig. 1, the reference character A designates a railway track switch, and the reference character B designates a device for operating the switch A. The switch A comprises, as usual, two fixed rails and la and two mov-- able rails or switch points 2 and 2a, the switch points being connected together adjacent their tips by a head rod 3. 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 and the movable rail 2a is'spaced a slight distance from the fixed rail Ia. When the switch is reversed, the movable rail 2a then engages the fixed rail la and the movable rail 2 is spaced from the fixed rail The operating device B, ashere shown, comprises a switch stand 5 having its base 5a spiked or otherwise secured to the ties adjacent to switch A. A gear shaft 6 is journaled in the switch stand and carries a crank I and a gear segment 8. The gear segment 8 meshes with a pinion gear 9 keyed to a pinion shaft Hi. The pinion shaft l extends through the side of switch stand and has attached to its outer end the usual weighted switch throwing lever I The crank of the switch throwing device B is connected with a crank rod 1a and that in turn is connected with head rod 3 of switch A by a novel and improved mechanism embodying my present invention and designated as a whole by T the reference character C. As can be seen in Figs. 2 and 3, the mechanism 0 comprises a housing l4 having sheet steel sides and bottom and a removable cover I5 secured as by bolts Hi to flanges provided on the side members. Cover |5 extends from one end of the housing to a point short of the other end, and the remainder of the top of the housing is provided with an inspection cover I! secured as by bolts l6 to flanges provided on the sidewalls and shaped to enclose a latch device M hereinafter referred to. The ends of the housing M are preferably enclosed by cast steel end members l9 and 20, to which the sidewalls, bottom and cover members of the housing are fastened by bolts Hi. The housing I4 is sup ported by pipe rollers 2| carried by pipe brackets 22 (see Fig. 1) secured as by spiking to the ties.

End member l9 has an outwardly extending lug 23 provided with a jaw 24 which is connected by-means of a pin 25 with crank rod- 1a of the switch throwing device B. The other end mem- Figs. 6a, 6b, 6c, 6d and 6e are views plate 3| and carried on a pin 34 journaled in bearlugs 35 supported in the sidewalls'of housing |4. Motion plate 3| is guided laterally by shoulders 36 formed on sleeves 31 provided on-pin 34 and disposed between roller 32 and bearings 35.

.Motion plate 3| has-its opposite longitudinally disposed edges formed with cam surfaces symmetrically disposed about the horizontal axis of the plate. The' surfaces are shaped to coact with two spring biased rollers 39 in biasing the plate to the neutral position in whichit is illustrated in Fig. 3, and with two other spring biased rollers 40 which initially function to bias plate 3| to its neutral position but which also function to force the plate to either of two extreme positions after the plate has been displaced from its neutral position about three-quarters of the way'to either extreme position.

The two'rollers 39 which bias the plate to its neutral positionare disposed to engage the opposite cammed edges of plate 3| and each has associated therewith a pair of leaf springs 4| disposed on opposite sides of the motion plate.

her 20 is provided with a central bore 23 inwhich is mounted a. rod 21 provided On its outer end ,with an adjustable screw jaw 28 securedby pin 29 to head rod 3. The inner end of rod flliis threaded into a socket :3! formed on one ed of a motion plate 3| which is disposed in a we.

tical plane within housing l4 and is guided horizontally by a needle bearing roller 32 engaging the edges of a longitudinally disposed slot 33 in As can be seen in Figs. 2 and 3, the pair of springs 4| associated with the roller 39 which engages the top edge (as viewed in Fig. 3) of plate 3| is pinned at one end by means of a pin 42 journaled in lugs '43 formed in end member 20 disposed adjacent to the switch points, while the pair of springs associated with the bottom roller 39 is likewise pinned to end member 20 by nuts 48 threaded on the ends of the shackle arms, the two arms of the shackle 46 being inserted through loops provided on the end of the two springs 4| respectively. The free ends of the two springs 4|, one associated with each roller 39, disposed on the opposite side of the motion plate are likewise secured together by a U-shaped shackle '46.

Each roller 39 is connected with its associated pair of springs 4| by means of spring brackets 50 respectively secured by U-bolts 5| and nuts 52 to the two associated springs at their mid points. The rollers 39 are substantially similar to the rollers 40, so that the following description of the rollers 4|l will suflice to describe the rollers 39 as well. The rollers 40, shown best in Fig. 4. are of the needle bearing type with a hardened sleeve 54 pressed on a roller pin 55 mounted on either side of the roller in the spring brackets 50, and the roller is spaced from the spring brackets by means of thimbles 56 mounted on pin 55 on either side of roller" anddisposed between the roller and the spring bracket. "The...

pin 55 has provided on one end a pressure grease fitting 51 threaded into adrilled opening 58 in the pinhaving branches extending through the hardened sleeve 54 for lubricating the needle' therefore, the vertical components of these forces balance and cancel each other so that no lateral thrust is exerted on plate 3|. The surfaces with biased by their respective which the rollers 39 cooperate are formed with .an accentuated curved portion disposed cenof the order of, say, 1200 pounds, sufficient to prevent the switch points from creeping from their position of correspondence with operating device B and forcing rollers 39 out of their neutral position. Whenever there is relative motion between the motion plate 3| and housing M, the rollers 39 will be forced out of their neutral position and will be forced apart by the sloped portion of the cammed surfaces. The cam surfaces arepreferably curved surfaces designed in such a manner that increasing displacement of the rollers results in decreasing the horizontal component of the forces exerted by the rollers on the plate opposing the motion of the'plate, due to the fact that the cam slope. falls off faster than the spring force increases.

These forces will, of course, be available to restore the motion plate 3| to its neutral position and the switch points to their original operated position upon removal of the force which caused the relative motion between the plate and housing.

The other two rollers 40 which force the plate to either of two extreme positions in the event that plate 3| is displaced from its neutral position about three-quarters of the way to an exlreme posi ion, are also disposed to engage the opposite edges of the plate. Each roller 40 has associated therewith a pair of leaf springs 66, disposed on either side of motion plate 3| and connected with the associated roller 40 by means of spring brackets 50. bolts and nuts 52 in the manner pointed out in detail hereinhefore. springs 60 have their one ends formed with loops and each pair has a pin 6| inserted through its loops and journaled in bearings 62 mounted in the sidewalls of housing M and in a reinforcing strip 18 secured to the sidewalls. The otherends of the sprin s are also formed with loops and the two springs 6|] associated with the upper roller 4!] (as viewed in Fig. 3) are pinned together by a pin 63 inserted through the .end loops of the springs and journaled in two arm members 64 (see Fig. 5)-disposed on either side of and pinned by a pin 65 to a latch member 66. Two other arm members 61, also disposed on opposite sides of latch member 66, journal a pin 68 which is inserted through the loops of the two remaining springs 60 associated with the bottom roller 40, and these two other arms 61 are also pinned by a pin 69 to latch member The latch member-66 is rotatably mounted, at

a point substantially equi-distant from the pins 65 and 69, on a pivot pin journaled in bear- .ings H mounted in the sidewalls of housing Id.

The member 66 is controlled by 'a latch device M controlled by traflic conditions on the switch and having two positions. one a latching position established when the switch is occupied and the other an unlatched position established when the switch is vacant. Device M is operatively connected with latch member 66 and func- The V tions in the one (latched) position to retain member 65 in its normal position, as shown in Figs. 3 and 5, against the action of springs 60 in the event that the rollers 40 cause the springs to be displaced from their normal positions illustrated in Fig. 3. In the other (unlatched) position, the member 66 is permitted to move under the action of 'the springs 60, as will bemade clear presently.

The control of device M bytraflic on the switch may be established mechanically, hydraulically or electrically. For example, device M may be an electromagnet controlled in any suitable manner so as to be energized whenever a train occupies the track portion immediately adjacent to and including the track switch. As indicated in the drawings, this control is established by a circuit including a back contact of a track relay TR incorporated into a detector track circuit provided for the stretch of track including the track switch. In such a case, the

. detector track section will have a length preferably longer than the distance between trucks of the longest vehicle tobe operated over the switch.

The electromagnet M is supported on a cross member 16 extending laterally across housing M and secured to the sidewalls thereof, and is opcratively connected with latch member 66 by means of an armature 72 carried by member 66.

The armature 12 is normally positioned adjacent to th pole pieces of the magnet by means of a which the rollers cooperate are provided with two sloping surfaces which flare upwardly from a central or neutral position for a distance corresponding to approximately three-quarters of the distance covered by the switch points in moving from either extreme (normal or reverse) position to the other. sponding to the remainder or last quarter of the distance coveredby the switch points in moving to an extreme position, have sharply inclined inward slopes. v

The springs 6|] are selected to be of equal strength and have associated therewith deflection members clamped between the springs 60 and the associated spring brackets 50. The deflection members 80 are shaped so as to deflect each spring 6|] enough to position the .two rollers 40 just out of engagement with the opposite cammed edges of .motion plate 3| when the motion plate is in a neutral position as represented in Fig. 3 wherein the rollers are adjacent to the neutral portion of the cam surface. The latch linkage and biasing spring 13 are designed so that under the conditions assumed where magnet M is deenergized, the latch linkage holds the springs 60 in the normal position illustrated in Fig. 3. energized, the forces of the latch'springs 13 and magnet M cooperate to hold the latch linkage in the position illustrated in Fig. 3 in the event that relative motion obtains between the motion plate 3| and housing I4. In such an event, the rollers 40 will be displaced from their neutral positions and will be forced apart as the rollers follow the outwardly sloping portionso-f the cam surfaces, thereby applying to the plate forces having.horizontal components which tend to oppose the motion of the plate. The vertical components of these forces cancel each other so that The cam surfaces corre- When magnet M is 'that extreme position in opposition to'the restoring forces applied by springs 4| to the plate. The

springs 60 and the cooperating cam surfaces of plate 3| are selected so that under the conditions assumed, the rollers 40 exert on plate 3| forces which have horizontal components exceeding in value the horizontal components of the restoring forces exerted by rollers. 39 on the plate.

When the detector sectionisunoccupied, magnet M is deenergizedf The switch A may be operated manually under the conditions assumed to either its normal or reverse position as desired by means of the manual operating device B. That is, movement of the switch throwing lever II from either extreme position to the other will result in rotation of crank 1 and this rotation of the crank will be transferred through the spring biasing mechanism to the switch pointsto cause a corresponding movement of the points to be effected, it being noted that the biasing forces appliedby springs 4| to the motion plate 3| are sufficient to oppose relative motion between housing l4 and plate 3| so that the housing and plate will move as a unit on thepipe rollers 2| when the switch operating lever II is thrown manually.

-With the switch points in either of their extreme positions, the entrance of a train on the switch will cause energization of magnet M and that magnet will attract and hold armature 12. If the train operates over the switch in the direction forwhich the points are set, the energization of magnet M will have no function at this time, but if the train trails the switch, then magnet M functions to hold the latch linkage in its normal position, as represented in Fig. 61), while the rollers 39 and 40 are forced apart due to the motion plate being moved relative to housing M by the opening of the switch points. As

a result, both rollers 39 and 40 exert on plate 7 3| forces having horizonta'l components which oppose motion-bfv the plate.

'When the points are driven approximately three-quarters of the way'from theiroriginal to their opposite position by the first trailing wheel, the rollers 40 then engage the inwardly sloping portion of the associated cam surface. -'I'he directions of the horizontal components of the forces exerted by rollers 40 On plate 3| are now reversed, and the plate 3| is driven to its extreme position corresponding to the opposite position of the switch points. The plate 3| is held in its latter position by the forces exerted thereon by rollers 40, which forces have horizontal components which'exceed in value the and latch member 66 is flipped to the position represented in Fig. 6d in response to the forces applied by the springs through arm members 64 and 61 to the latch member 66. This results in releasing springs 60 and decreasing the horizontal components of the forces applied by rollers 40 to plate 3| to avalue less than the horizontal components of the restoring forces exerted by rollers 39 upon the plate, whereupon the plate is driven back toward its neutral position to cause a corresponding movement of the switch points toward their original positions (see Fig. Be). When the motion plate 3| occupies its neutral position wherein the rollers 39 engage the accentuated curved portions of the associated cam surfaces, the switch points will then occupy their corresponding original positions and. rollers 40 will likewise occupy their neutral positions to which they are biased. In this condition of the apparatus, the biasing springs 13 restore the latch linkage to its normal position as represented in Fig. 3.

It is to be noted, that the mechanism mbodying my invention may be incorporated between any switch operating mechanism and the associated switch points and will convert that switch to operate for trailing movements. It is further to be noted that my mechanism incorporates into a single operating unit the springs -heretofore required for spring movement and the locking and restoring means for locking the points in their trailed positions and restoring the points to their original positions, respectively.

Although I have herein shown and described only one form of railway track 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.

Having thus described my invention, what I claim is:

1. In combination with a railway track switch and a switch operating mechanism movable between two extreme positions, means for operatively connecting said mechanism with said switchnormally' efiectiveto bias the switch to an extreme position corresponding to the position of said mechanism, said means including biasing members constantly effective to bias said switch to said corresponding position and other biasing members initially efiective upon movement of said switch when trailed to aid said firstmentioned biasing members and effective when said switch is moved a predetermined distance toward its trailed position' for operating said I switch to the extreme position out of correspond- 'horizontal components of the forces exerted by ence with said-mechanism by a force which op poses and exceeds the biasing force of said firstmentioned biasing members, and means. controlled by tramc' on said switch effective when said switch is in its said out of correspondence position for reducing the force' exerted by said other. biasing members on said switchto a value below that exerted thereon by said first-mentioned biasing members whereby to permit said 2. In combination with a railway track switch and a switch operating mechanism movable between two extreme positions, a first member connected with said switch, a second member connected with said operating mechanism, first biasing means connected with said second memher and acting on said first member to bias said switch to an extreme position corresponding to the position of said operating mechanism, a device controlled by trafiic on said switch and having a first condition when said switch is occupied and a second condition when said switch is vacant, and second biasing means connected with said second member and acting on said first member effective when said device is in its said first condition and said switch is trailed by 'a vehicle for initially opposing movement of said.

switch to its trailed position and effective when said switch is operated a predetermined distance toward its trailed position for biasing said switch to its trailed position by a force exceeding that exerted on said switch by said first biasing-means, said second biasing means being controlled by said device to be efiective when said device is in its second condition and said switch is in its extreme trailed position to reduce the force exerted by said second biasing means on said switch to a value below that exerted on said switch by said first biasing means, whereby said switch when trailed is held in its extreme trailed position out of correspondence with said operating mechanism until said device is in its second condition whereupon said switch is restored to its corresponding position bythe force exerted on said first member by saidfirst biasing means.

3. In combination with a railway track switch and a switch operating mechanism movable between two extreme positions, means for operatively connecting said mechanism with said switch normally effective to bias the switch toan extreme position corresponding to the position of said mechanism, said means comprising biasing members constantly efiective to bias said switch to said corresponding position, an electromagnet controlled by traific on said switch,

and other biasing means controlled by said electromagnet to be effective when said electromagnet .is energized and said switch is trailed by a vehicle for initially biasing the switch to its corresponding position but effective when said switch is operated a given distance toward its trailed position for biasing said switch to its trailed position by a force greater than the biasingv force of said first-mentioned biasing members, said otherbiasing means being controlled by said electromagnet to be effective when said switch is in its trailed position and said electromagnet is deenergized for reducing the force exerted by said other biasing means on said switch to a value less than the force exerted thereon by said first-mentioned biasing members, whereby said switch when trailed is held in its trailed position until said electromagnet is deenergized and is then restored to its corresponding position by electromagnet controlled by traflic on said switch, and second biasing means connected with said second member and acting on said first member effective when said electromagnet is energized and said switch is trailed by a vehicle for initially opposing movement of said switch to its trailed position and effective when said switch is operated a predetermined distance toward its trailed position for biasing said switch to its trailed position by a force exceeding that exerted on said switch by said first biasing means, and means controlled by said electromagnet effective when said electromagnet its deenergized and said switch is in its said trailed position r for reducing the force exerted by said second biasin means on said first member to a value below the force exerted by said first biasing means on said first member, whereby said switch when trailed is held in its extreme trailed position out ofcorrespondence with said operating mechanism until said electromagnet is deenergized and is then restored to its corresponding position by the force exerted on said first memher by said first biasing means.

5. In combination with a,railway track switch and a switch operating mechanism movable between two extreme positions, a first member connected with said switch, a second member conasing' means when said electromagnet is energized and said switch is trailed by a vehicle to exert on said switch a force whichinitially opposesmovement of said switch to its trailed position and to cause said second biasing means when said switch is operated a predetermined distance toward its trailed position, to bias said switch to its extreme trailed position by a force which exceeds the force exerted on said switch by-said first biasing means, said electromagnet when deenergized being efiective to reduce the 1 force exerted by said second biasing means on said switch to a value lower than the force exerted on said switch by said first biasing means, whereupon said switchis restored by the force exerted thereon by the said first biasing means to its extreme position corresponding to the position of said operating means.

6. In combination with a railway track switch and a switch operating mechanism movable between two extreme positions, a first member connected with said switch, a second member connected with said operating mechanism, first biasing means connected with said second member, cam surfaces formed on said first member engaged by said first biasing means and shaped pied and a second position when said switch is vacant, second biasing means connected with said second member, other cam surfaces formed on said first member engaged by said-second biasing means and shaped to cause said second biasing means when said device isin its said first position and said switch is trailed by a vehicle to exert on said switch a force which initially opposes movement of said switch to its trailed position and to cause said second biasing means when said switch is operated a predetermined distance toward its trailed position, to bias said switch to its extreme trailed position by a force which exceeds the force exerted on said switch by said first biasing means, said device when in its said second position being eifective to reduce the force exerted by said second biasing means on said switch to a value lower than the force exerted on said switch by said first biasing means, whereupon said switch is restored by the force exerted thereon by the. said first biasing means to its extreme position corresponding to ing mechanism movable between two extreme positions, first spring biased members operatively connected with a first of said two operating members, cam surfaces formed on the second of said two operating members engaged by said first spring biased members and shaped to cause said first spring biased members to exert on said second operating member a force which biases said switch to an extreme position corresponding to the position of said operating mechanism, an electromagnet, second spring biasing members operatively connected with said first operating m'ember, other cam surfaces formed on said second operating member engaged by said second spring biasing members and shaped to be effective when said electromagnt is energized and said switch is trailed by a vehicle for causing said second spring biasing members to exert on said second operating member a force which initially opposes movement of said switch to its trailed position but which is efifective when said switch is moved a predetermined distance toward its trailed position to bias said switch to its extreme trailed position by a force which exceeds the force exerted is moved relative to the other operating member to cause 'said second spring biasing means to exert on said second operating member a forcewhich by said first biasing means on said switch, whereby when said switch is trailed it is operated to and held in its trailed position so long as the electromagnet is energized and said electromagnet being effective when deenergized to reduce the force exerted by said second biasing means on said second operating member to a value below the force exerted thereupon by said first biasing means whereupon said switch is restored to its position of correspondence with said operating mechanism.

8. In combination, two operating members each operable between two extreme positions, first spring biasing means operatively connected with a first of said operating members, cam surfaces formed on the second of said operating members engaged by said first spring biasing means and shaped to cause said firstspring biasing members to exert on said second operating member a force which biases said two operating members into corresponding relative positions, an electromagnet, second spring biasing means operatively connected with said first operating member, other cam surfaces on said second operating member,

engaged by' said second spring biasing means and shaped to be eflective when said electromagnet is energized and either of said operating members initially opposes relative movement between said operating members and is effective when either operating member is moved a predetermined dis tance to assist such movement and bias said two operating members topositions out of correspondence with each other by a force which exceeds the force exerted on said second member by' said first spring biasing'means, said electromagnet being efiective when deenergized to reduce the forces exerted by said second spring biasing means on said-second operating member to a value less than'the force exerted by said first spring biasing means on said second operating member, whereby said operating members are restored to corresponding relative positions when said electromagnet is deenergized.

9. In combination, two operating members each operable between two extreme positions, first spring biasingmeans operatively connected with afirst of said operating members, cam surfaces formed on the second of said operating members engaged by said first spring biasing means and shaped to cause said first spring biasingmembers to exert on said second operating member a force which biases said two operating members into corresponding relative positions, an electromagnet, a latch linkage controlled by said electromagnet, second spring biasing means operatively connected with said first operating member and controlled by said latch linkage, other cam surfaces on-said second operating member engaged by said second spring biasing means and shaped to be effective when said electromagnet is energized and either of said operating members is moved relative to the other operating member to cause said second spring biasing means to exert on said second operating member a force which initially opposes relative movement between said 1 operating members'and is effective when either operating member'is moved a predetermined distance to assist such movement and bias said two operating 'members to positions out of corre'-- ing member, whereby said operating members are restored to corresponding relative positions when said electromagnet is deenergized.

10. In combination with a railway track switch' and an operating mechanism movable between two extreme positions, a housing member operatively connected with said operating mechanism, a motion plate disposed in said housing member and attached to a rod slidablymounted in an opening in said housing member and connected with said switch, biasing means attached to said housing member and acting on said motion plate to bias said switch and operating members into corresponding relative positions, aleaf spring pinned at one end to said housing member, an

electromagnet, anarmature member rotatably' mounted for movement toward and away from the pole pieces of said electromagnet, a linkage member pinned at one end to said armature member and at the other end to the other end of said spring, a roller connected with said spring, cam surfaces formedon an edge of said motion plate that or the resultant of the parallel-directed engaged by said roller and shaped to cause said roller to exert on said motion plate a force efiective initially upon relative movement of said switch and operating-mechanism to oppose such relative movement but which force due to the shape of said cam surface becomes effective upon displacement of said switch a given distance plate a force which exceeds the value of the force exerted on said motion plate by said biasing means and when said electromagnet'is deenergized the force exerted by said roller decreases to a value below that exerted by said biasing means. I

11. In combination with a railway track switch and an operating mechanism movable between two extreme positions, a housing member operatively connected with said operating mechanism, a motion plate disposed in said housing member and attached to a rod slidably mounted in an "opening in said housing member and connected with said switch, biasing means attached to said housing member and op-eratively connected with said motion plate for exerting thereon forces which havea resultant component of zero magnitude directed perpendicular to the axis of said rod and which have components directed parallel to the axis of saidrod eifective to bias said switch and operating members into corresponding relative positions, a leaf spring pinned at one end to said housing member, an electromagnet, an armature member rotatably mounted for movement, toward and away from the pole pieces of said electromagnet, a linkage member pinned at one end to said armature member and at the other end to the other end and an operatingmechanism movable between twoextreme positions, a housingmember operatively connected with said operating mechanism, a motion plate disposed in said housing member and attached to a rod slidably mounted in an opening in said housing member and connected with said switch, biasing means attached to said housing member and acting on said motion plate to bias said switch and operating members into corresponding relative positions by a force which has a relatively high value when said switch and operating meshanism occupy corresponding relative positions and which force decreases in value when said switch is operated to a position out of correspondence with said operating mechanism, a leaf spring pinned at one end to' saidhousing member, an electromagnet, an arma ture member rotatably mounted for movement toward and away from the pole pieces of said electromagnet, 'a linkage member. pinned at one end to said armature member, and at the other end to the other end of said spring, a roller connected with said spring, cam surfaces formed on an edge of said motion plate engaged bysaid roller and shaped to. cause said roller to exert on said motion platea force efiective initially upon relative movement of said switch and operating mechanism to oppose such relative movement of said spring, a roller connected with said spring, a

rod eiTective initially upon relative movement of said switch and operating mechanism to-oppose such relativemovement but which component due to the shape of said cam surface becomes effective upon displacement of said switch a given distance toward a position out of correspondence with said operating mechanism to assist in operating said switch to and in holding said switch in its said non-corresponding position, said electromagnet being effective through said armature member and saidlinkage member to control the magnitude of said component of the force exerted by said roller on said motion plate when said switch and operating mechanism occupy non-corresponding positions, in such-a manner that when said electromagnet is energized said component of the force exerted by said roller on said motion plate exceeds the value of the resultant of the parallel-directed components of the forces exerted on said motion plate by said first biasing means and when 'said electromag net is deenergized said component of the force exerted by said roller decreases to a value below but which force due to the shape of said cam surface becomes efiective upon displacement of, said switch a given distance toward a position,

ing position, said electromagnet being efiective through said armature member and said linkage member to control the magnitude of the fonce-e-x 'erted by said .roller on said motion plate When said I switch and operating mechanism occupy non-correspondingpositions, in such a manner that when said electromagnet is energized said roller exerts on said motion plate a force which exceeds the valueof the'iorce exerted on said motion plate by said biasing means and when said electromagnet is .deenergized the force exerted by said roller decreases to a value below that exerted by said biasing means.

13.v In combination with a railway track switch and a switch operating mechanism movable between two extreme positions, a housing member operatively connected with said operating mechanism, a rod mounted for sliding movement in an opening in said housing member and con- .nected with said switch, a motionplate disposed her, a first roller'conn'ected with said first spring, a

cam surfaces formed on an edge of said motion plate engaged by said first roller and shaped to cause said first roller'to exert on said motion plate a force whichbiases said switch and operating mechanism into corresponding relative positions, a second leaf spring pinned at one end to said housing member, an e'lectromagnet,

an armature member rotatablymounted for movement toward and away from the pole pieces of said electromagnet, a linkage member pinned at one end to said armaturemember and at thea second roller connected with said second spring, other cam surfaces formed on an edge of said motion plate engaged by said second roller and shaped to cause said second roller to exert on said motion plate a force effective initially upon relative movement of said switch and operating mechanism to oppose such relative movement but which force due to the shape of said other cam surface becomes effective upon displacement of said switch a given distance toward a position out of correspondence with said operating mechanism to assist in operating said switch to and in holding said switch in its said non-corresponding position, said electromagnet being effective through said armature member and said linkage member to control the magnitude of the force exerted by said second roller on said motion plate when said switch and operating mechanism occupy non-corresponding positions, in such a manner that when said electromagnet is energized said second roller exerts on said motion plate a force which exceeds the value of the force exerted on 1 said motion plate by said first roller and when said electromagnet is deenergized the force exerted by said' second roller decreases to a value below that exerted by said first roller.

with said rod, a first leaf spring pinned at one end to said housing member and having its other end yieldingly connected with said housing memher, a first roller connected with said first spring, cam surfaces formed on an edge of said motion plate engaged by said first roller and shaped to cause said first roller to exert on said motion plate a force which has a component which biases said switch and operating mechanism into corresponding relative positions, said cam surfaces being further shaped to cause the said component of the biasing force exerted by said first roller on said motion plate to decrease in value as said switch is operated to a position out of correspondence with said operating mechanism, a second leaf spring pinned at one end to said housing member, an electromagnet, an armature member rotatably mounted for movement toward and away from the pole pieces of said electromagnet, a linkage member pinned at one end to said armature member and at the other end to.

the other end'of said second spring a second roller connected with said second spring, other cam surfaces formed on an edge of said motion plate engaged by said second roller and shaped to cause 'said second roller to exert on said motion plate a force which has a component effective initially upon relative movement of said switch and operating mechanism to oppose such relative movement but which force component due to the shape of said other cam surface becomes effective upon displacement of said switch a given distance toward a position out of correspondence with said operating mechanism to assist in operating said switch to and in holding said switch in its said non-corresponding position, said electromagnet being effective through said armature member and said linkage member to control the magnitude of the force component exerted by said second roller on said motion plate when said other end to the other end of said second spring,

switch and operating mechanism occupy noncorresponding positions, in such a manner that when said electromagnet is energized said second roller exerts on said motion plate a force component which exceeds the value of the force component exerted on said motion plate by said first roller and when said electromagnet is deenergized the force component exerted by said second roller decreases to a value below that exerted by said first roller.

15. In combination with a railway track switch and a switch operating mechanism movable between two extreme positions, a housing member operatively connected with said operating mechanism, an operating rod mounted in an opening in said housing member and operatively connected with said switch, a motion plate disposed within said housing and operatively connected with said operating rod, a first pair of springs having one end thereof pinned to said housing member and the freeends thereof connected together, two rollers one connected with each of said first pair of springs, cam surfaces formed on opposite edges of said motion plate engaged respectively by said two rollers and shaped to cause said two rollers to exert forces which bias said switch and operating mechanism into corresponding relative positions, a second pair of springs having one end thereof pinned to said housing member, an electromagnet, an armature member rotatably mounted on a shaft journaled in said housing member for movement toward and away from the pole pieces of said electromagnet, a biasing spring connected between said armature member and said housing member for biasing said armature memberto the pole pieces of said electromagnet, two linkage members pinned at one end respectively to said armature member on opposite sides of said shaft, means for connecting the free ends of said second pair of springs to the free ends of said two linkage members, two other rollers one connected respectively with each of said second pair of springs, and other cam surfaces formed on opposite edges of said motion plate engaged respectively by said two other rollers and shaped to cause said two other rollers to exert forces which initially bias said switch and operating mechanism into corresponding relative positions but which forces due to the shape of said other cam surfaces become effective upon movement of said switch a predetermined distance relative to the position of said operating mechanism to bias said switch and operating mechanism to positions out of correspondence, said electromagnet being effective through said armature member and linkage members to control the value of the forces exerted by said other rollers on said motion plate in such manner that when said electromagnet is energized and relative motion obtains between said motion plate and housing member said other rollers exert on said motionplate forces which exceed the forces exerted thereon by the firstmentiond rollers and when said electromagnet is deenergized said linkage members are displaced by theforces exerted thereon by said other pair of springs so that the forces exerted by said other rollers on said motion plate decrease to a value below that exerted on said motion plate by said first-mentioned rollers.

16. In combination with a railway track switch and a switch operating mechanism movable between two extreme positions, a housing member having one end thereof pinned to said housing member and the free ends thereof connected together, two rollers one connected with each of i said first pair of springs, cam surfaces formed on opposite edges of said motion-plate engaged respectively by said two rollers and shaped to cause said two rollers to exert forces thereon which have a resultant component of zero magnitude directed perpendicular to the axis of said operating rod and whichhave components directed parallel to the axis of said rod efiective to bias said switch and operating mechanism into corresponding relative positions, a second pair of springs having one end thereof pinned to said housing member, an electromagnet, an-armature member rotatably mounted on a shaft journaled in said housing member for movement toward and away from the pole pieces of said' electromagnet, a biasing spring connected between said armature member and said housing member for biasing said armature member to the pole pieces of said electromagnet, two linkage members pirmed at one end respectively to said armature member on opposite sides of said shaft,

, site edges of said motion plate engaged respectively by said two other rollers and shaped to cause said two other rollers to exert forces thereon which have a resultant component of zero magnitude directed perpendicular to the axis of said operating rod and which have components directed parallel to the axis of said rod effective initially to bias said switch and operating mechanism into corresponding relative positions but which parallel-directed components of the forces due to the shape of said other cam surfaces becofne effective upon movement of said switch a predetermined distance relative to the position of'said operating mechanism to bias said switch and operating mechanism to positions out of correspondence, said electromagnet being effective through said armature member and linkage members to control the value of the parallel-directed components of the forcesexerted by said other rollers on said motion plate in such manner that when said electromagnet is energized and relative motion obtains between said motion plate and housing member the parallel-directed components of the forces exerted by said other rollers on said motion plate exceed the paralleldirected components of the forces exerted thereon by the first-mentioned ro'llers and when said electromagnet is deenergized said linkage members are displaced by the forces exerted thereon by said otherpair of springs and the paralleldirected components of the forces exerted by said other rollers on said motion plate decrease to a value below that of the parallel-directed components of the forces exerted on said motion plate by said first-mentioned rollers.

HERBERT L. Bonn.

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