US2385492A - Railway switch operating apparatus - Google Patents

Description

Sept. 25, 1945. H, BONE 2,385,492

RAILWAY SWITCH OPERATING APPARATUS Filed Jan. 14, 1944 2 Sheets-Sheet 1 I N VENTOR ff pfierf Z 50129 H11 ATTORNEY Sept. 25, 1945. H. L. BONE 2,385,492

RAILWAY SWITCH OPERATING APPARATUS Filed Jan. 14, 1944 I 2 Sheets-Sheet? BY I 62:2 M

H11! ATTORNEY Patented Sept. 25, 1945 UNITED, STATES PATENT OFFICE RAILWAY SWITCH OPERATING APPARATUS Herbert L. Bone, Forest Hills, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application January 14, 1944, Serial No. 518,265

2 Claims (01. 246-411) My invention relates to railway switch operating apparatus, and particularly to switch operating apparatus of the type including a switch operating crank operatively' connected with the switch for moving it between its two extreme positions.

In switch operating apparatus of the type described it sometimes happens that the operating crank becomes displaced relative to the remainder of the switch operating apparatus due, for

example, to the application thereto of an abnormal force such as that which takes place when a train improperly trails the switch, and when this is the case, it is desirable in the interest of safety to prevent further operation of the switch operating apparatus until the damaged parts have been replaced.

One object of my invention is to provide simple and effective means for preventing subsequent operation of the switch operating apparatus in the event of abnormal displacement of the operating crank.

According to my invention, I provide limit stops for the operating crank so arranged that in normal operation these stops do not engage the crank but that in the event of displacement of the crank relative to the remainder of the parts of the switch operating apparatus, one stop or the other will then cooperate with the crank to prevent it from being operated to the extreme position opposite to that which it occupied when the displacement occurred.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

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

In th accompanying drawings, Fig. l is a plan view showing a railway switch operated by a switch operating mechanism embodying my invention. Fig. 2 is an enlarged top plan view of the switch operating mechanism shown in Fig. 1, the mechanism cover being removed to better illustrate the construction of the remaining parts. Fig. 3 is a vertical longitudinal sectional view of the mechanism shown in Fig. 2 taken substantially on the line III-III of Fig. 2. Fig. 4 is a sectional view taken on the line IV-IV of Fig. 3. Fig. 5 is a detail of a part of the switch operating mechanism shown in the preceding views.

Similar reference characters refer to similar parts in all views.

Referring first to Fig. 1, the reference character A designatesa railway switch comprising, as usual, two fixed rails l and la and two mov able rails or switch points 2 and 2 a. The fixed rails l and la. are laid on tie plates 3, and are secured to crossties 4 in the customary manner; The movabl rails 2 and 2a are fastened together by a front rod 5 and a head rod 6, and may be moved into a normal or a reverse position by means of a throw rod I which is connected to the head rod 6 through the medium of a switch basket 8. When the switch occupies its'norrnal position, in which position it is shown in the drawings, the movable rail 2 engages the fixed rail I, and the movable rail 2a is spaced from the fixed rail la. When the switch is reversed, however, the movable rail 2a then engages the fixed rail la, and the movable rail 2 is" spaced from the fixed rail I.

Secured to an elongated pair'of the ties 4 adjacent the outer side of the rail l is a switch operating mechanism B embodying my invention. As best seenin Figs. 2, 3 and 4', the mech anism B in the form here shown comprises a suitable casing In which encloses the operating parts of the mechanism, and which is closedat its upper end by a removable cover I l. Located within the casing to is a motion plate I2 which is guided to slide longitudinally of the casing It) by means of guide rollers l3 and M secured to the underside of the'motion plate adjacent its opposite ends and cooperating with a guideway l5 provided in the bottom wall of the casing. The motion plate l2 has rack teeth 16 formed in its upper surface on one side of the center line. These rack teeth mesh with a segment gear I I mounted on a square shaft l8,

which shaft, in turn, is mounted adjacent its ends in suitabl bearings provided in the opposite side walls of the casing l0. Secured to the outer end of the shaft I8 is a hand throw lever l9 which serves as a means for reciprocating the motion plate between its two extreme positions.

A roller 20 is secured to the underside of the motion plate l2 adjacent one side thereof at a point equally spaced from the rollers i3 and I4, and this latter roller cooperates with cam faces 2| and 22 formed on an escapement crank 23. The escapement crank 23 is formed integrally with the upper end of a switch actuating shaft 24, the shank of which is provided with twd bear ing surfaces 25 and 26 separated by a squared portion 21. The bearing surfaces are journaled in vertically aligned bearings 28 and 29 formed respectively in the bottom wall of the casing Hi,- and in a depending stirrup 30 provided on the underside of the casing, and mounted on the squared portion 21 of the shaft is a switch operating arm 3| which is pivotally attached to the free end of the operating rod 1.

A lock bar 32 extends longitudinally of the casing l directly above the motion plate l2, and cooperates at its left-hand end, as viewed in Figs. 2 and 3, with a lock rod L' which is slidably mounted in a transversely extending guideway 33 formed in th casing 12. The lock rod L in the form here shown is of a well-known construction, and is secured at one end to the front rod 5 of the switch A. Formed in the lock rod is a notch 34 so disposed that itwill align with the lock bar 32 when and only when the switch A occupies the extreme position in which it is shown in Fig. l. The lock bar may, if desired, be operated by operating means located at a point remote from the mechanism as described in detail in Letters Patent of the United States No. 2,184,870, granted to myself and another on,

December 26, 1939, for Railway switch operating mechanisms, in which event it is commonly referred to as a loos lock bar, or, as shown, it may be operatively connected with the motion plate l2 by means of a stud 35 secured to the lock bar and extending into a transversely extending slot 36 formed in the upper side of the motion plate.

The portion of th switch operating apparatus thus far described is identical with that shown and described in the patent just referred to and its operation as a whole is as follows. When the hand throw lever I9 is rotated to its normal extreme position in which it is shown in the drawings, th motion plate I2 is moved to its extreme left-hand or normal position in which it is shown in Figs. 2 and 3, and under these conditions the switch points are held in their normal positions by engagement of the roller 20 with the cam surface 2| of the escapement crank 23. Furthermore, under these conditions, the lock bar 32 enters the notch 34 in the lock rod L, thus locking th switch points segment gear I! and rack teeth 16 to move the motion plate to its right-hand extreme position, and as the motion plate moves to this latter position, the first part of the movement withdraws the lock bar 32 from the notch 34 in the lock rod L to unlock the switch, the intermediate part of the movement causes the roller 20 to engage the cam surface 22 of the escapement crank 23 and rotate the escapement crank to the position in which the straight portion of the cam surface 22 extends parallel to the track, thereby rotating the switch actuating shaft to its reverse extreme position, and hence moving the switch points to their reverse extreme positions, while the final part of the movement causes the roller 20 to move along the straight portion of the cam surface 22 to such a position that any tendency of the switch actuating shaft 24 to rotate in a direction to permit the switch points to move away from their'reverse extreme positions is effectively blocked by the roller; It will be seen, therefore, that when the switch points occupy their reverse extreme positions, they are effectively held in these positions du to the coaction between the roller and the escapement crank, and it will also be seen that any force which may be exerted on the switch tending to restore it to its normal position will cause a transverse force to be exerted on the motion plate rather than a longitudinal force, thus avoiding any tendency to reverse the hand throw lever due to any force which may be exerted on the switch.

When the switch has been moved to its reverse position, and it is desired to restore it to its normal position, the hand throw lever I9 is returned to the position shown. The operation of the parts under these conditions is exactly the reverse of that just described, and this operation will be apparent from the foregoing description and from an inspection of the drawings without further detail description.

When the loose type of lock bar is used instead of the typ shown, the operation of the apparatus is similar to that just described except for the fact that the lock bar 32 has to be moved to its unlocking position by the remotely located operating means before the hand throw lever l9 can be operated to reverse the switch, and to be restored to its locking position to lock up the switch after the hand throw lever is restored to the position shown.

With the switch operating mechanism constructed in the manner just described, if the switch is improperly run through, it will usually be found that some part of the mechanism is broken or distorted. The part which generally becomes distorted is the switch actuating shaft 24 or the switch operating arm 3|, and the result of the distortion is to cause angular displacement of the operating arm 3|. When distortion occurs, unless means are provided to prevent continuance of service of the distorted part,

- the maintainer will usually correct for the distortion by adjustment of the operating rod connection after the switch point damag has been repaired. The cold working of the parts which takes place while the distortion is taking place tends to make the parts brittle, and if the overstressing of the parts is repeated several .times, there is a possibility that breakage will result.

This is undesirable, and in accordance with my present invention I provide the mechanism with limit stops and 4| (see Fig. 4) which are cast on the vertical portion of the stirrup 30 on opposite sides of the operating arm 31 in such position that when the arm is rotated to the extreme position it normally occupies when the switch points are in their proper normal extreme positions, the arm 3| will, just clear the stop 43, and that when the arm is rotated to the extreme position it normally occupies when the switch points are in their proper reverse extreme positions, the arm 3| will just clear the stop 4|, but that, when the arm becomes angularly displaced due to distortion of some part of the mechanism, the arm will engage one or the other of the limit stops and will thus prevent the hand throw lever l9 from completing its stroke when the switch operating mechanism is next operated to reverse the switch. Inasmuchas the engagement of the arm with one or the other of the limit stops prevents the hand throw lever from completing its stroke, the maintainer is forced to replace the distorted part of the switch mechanism, and as a result the presence of a dangerous condition resulting from restoring the switch to service with embrittled parts is effectively prevented. I

It should be particularly pointed out that when distortion occurs, the force which gives rise to the distortion will always be in the direction to move the arm 3| away from the contiguous stop, and these stops do not therefore come into play until the mechanism is subsequently operated to reverse the switch. It should also be pointed out that since the stops do not come into play until distortion occurs, they do not in any way afiect the normal operation of the switch operating mechanism.

It should also be particularly pointed out that while I have shown my invention applied to a particular type of switch operating mechanism, it is not limited to any particular type, but on the contrary it can be applied to any type of mechanism which employs a switch operating arm similar to the arm 3| or its equivalent.

Although I have herein shown and described only one form of 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 a switch operating mechanism including a switch operating arm adapted to be connected with a railway switch and operable between two extreme positions for operating the switch between its two extreme positions, the combination of means for detecting distortion of the parts of said mechanism resulting in displacement of said arm from its normal position relative to other parts of said mechanism comprising two stops positioned to just clear said arm in its two extreme positions, respectively, and efiective upon displacement of the arm away from one extreme position toward the other to engage said arm when said mechanism is next operated to reverse the switch to prevent the complete reversal of the mechanism, whereby the displacement of said arm will be detected.

2. In a switch operating mechanism comprising a mechanism casing, a stirrup formed in the bottom of said casing, a switch operating crank journaled in aligned bearings provided in the bottom wall of said casing and in said stirrup, means in said casing connected with said shaft for rotating said shaft between two extreme positions, and a switch operating arm secured to said shaft between said bearings and operatively connected with a switch for operating the switch between its two extreme positions, the combination of means for detecting distortion of the parts of said mechanism resulting in angular displacement of said switch operating arm from its normal position relative to other parts of said mechanism comprising limit stops provided in said stirrup on onposite sides of said arm in such positions that when the arm is rotated to the extreme position it normally occupies when the switch points are in their proper normal positions the one stop will just clear said arm and that when said arm is rotated to the extreme position it normally occupies when the switch points are in their proper reverse positions the other stop will just clear said arm, but that, if said arm becomes angularly displaced due to distortion of some part of said mechanism from its normal position relative to other parts of said mechanism the arm will then engage one or the other of said limit stops and will thus be prevented from completing its stroke when the switch operating mechanism is next operated to reverse the switch, whereby the displacement of the arm will be detected.

HERBERT L. BONE.

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