US3691371A

US3691371A - Trailable railway switch machine

Info

Publication number: US3691371A
Application number: US57571A
Authority: US
Inventors: Lyle L Hylen
Original assignee: Westinghouse Air Brake Co
Current assignee: Hitachi Rail STS USA Inc
Priority date: 1970-07-23
Filing date: 1970-07-23
Publication date: 1972-09-12
Anticipated expiration: 1989-09-12
Also published as: CA943661A

Abstract

This disclosure relates to a trailable railway switch machine for use in classification yards and the like for moving the switch points between their two extreme positions. The switch machine includes a motion translating mechanism having a box shaft, a pivot block, a clevis, a link and a hand throw toggle shaft. A hand throw lever is connected to the hand throw toggle shaft. An electric motor is connected through a gear train, an electric clutch, a pinion and rack to a roller engaging a slotted arm of the box shaft. The switch points are connected through an operating rod by a cam roller engaging the slotted arm. The switch points may be selectively shifted either when the hand throw lever is manipulated or when the electric motor is energized. No movement is imparted to the hand throw lever or the motor and gear train when the switch points are trailed to the wheels of a railway vehicle.

Description

United States Patent Hylen [451 Sept. 12, 1972 TRAILABLE RAILWAY SWITCH MACHINE Lyle L. Hylen, Wilkinsburg, Pa.

Assignee: Westinghouse Air Brake Company,

Swissvale, Pa.

Filed: July 23, 1970 Appl. No.: 57,571

Inventor:

US. Cl ..246/393, 246/284 Int. Cl. ..B61l 5/06 Field of Search ..246/282, 284, 318, 240, 393,

References Cited UNITED STATES PATENTS 6/ 1969 Wilson et al ..246/411 12/ 1969 Wilson ..246/242 X 7/ 1951 Stephenson ..246/393 X Primary Examiner-Arthur L. La Point Assistant Examiner-George H. Libman Attorney-H. A. Williamson, A. G. Williamson, Jr. and J. B. Sotak [57] ABSTRACT This disclosure relates to a trailable railway switch machine for use in classification yards and the like for moving the switch points between their two extreme positions. The switch machine includes a motion translating mechanism having a box shaft, a pivot block, a clevis, a link and a hand throw toggle shaft. A hand throw lever is connected to the hand throw toggle shaft. An electric motor is connected through a gear train, an electric clutch, a pinion and rack to a roller engaging a slotted arm of the box shaft. The switch points are connected through an operating rod by a cam roller engaging the slotted arm. The switch points may be selectively shifted either when the hand throw lever is manipulated or when the electric motor is energized. No movement is imparted to the hand throw lever or the motor and gear train when the switch points are trailed to the wheels of a railway vehicle.

9 Claims, 3 Drawing Figures Hum/nu PATENTED SE? 12 m2 sum 1 BF 2 mg mm Q m g PAIENTED SEP 12 m2 sum 2 or 2 II II/I l I III III] I TRAILABLE RAILWAY SWITCH MACHINE My invention relates to a trailable electrical railway switch machine and, more particularly to an improved yard switch mechanism which is capable of selectively shifting the switch points between their extreme positions by energizing an electric motor for driving the switch points or by rotating a manual hand lever for throwing the switch points, and which is adapted to freely permit the switch points to be trailed by the wheels of railway vehicles without any resultant damage to the switch mechanism or any impending danger to individuals in the vicinity of the switch mechanism.

A railway switch machine which has some degree of universal usage generally requires at least two alternate modes of operation. For example, in automatic classification yards, it is desirable to provide both a power operating mode as well as a manual operation option for moving the switch points between their two extreme positions. That is, in humping and classification of the railway cars or cuts of cars, the railway switches which set up the routes are either automatically controlled from a remote location either by a computer or by a yardmaster, and therefore, power operation of the switch machine is required for such automatic operations. Likewise, on many occasions, it is necessary to provide a manual method of manipulating the railway switches. For example, during emergency periods, such as, power failures, or during train pullout at the exit end of the classification yard, it is advantageous to provide a manual means, such as, a hand throw lever for moving the switch points between their two extreme positions. It has also been found desirable in yard applications to provide switch machines of the trailable type in order to prevent derailment which obviously results in prolonged delays in shipping as well as causes costly damage to equipment and lading. Thus, a railway switch machine for use in classification yards must be capable of being operated in three different fashions, namely, manual operation by a hand throw lever, power operation by a suitable operator and a trailing operation by the wheels of passing railway vehicles.

While several switch machines capable of functioning in such a manner have been previously proposed, each of these previous switch machines is possessed of certain inherent disadvantages. In some arrangements the efficiency and reliability of operation are unacceptable while in others the constant hazard and danger to which attending personnel are exposed to is intolerable.

For example, in past trailable switch machines, hydraulic operators have been utilized for power driving the points between their two extreme positions. It will be appreciated that the use of hydraulic operators requires an external source of hydraulic power which is not always readily available at the various locations in classification yards. In some cases where external hydraulic power is not available previous trailable switch machines have been equipped with a separate electric motor and pump for providing operating power for the hydraulic operator so that great versatility has been achieved. However, it will be appreciated that electrically powered hydraulically operated trailable switch machines are relatively inefficient in that extra power is consumed and wasted. For example, any multiple conversion arrangement which changes electrical power to hydraulic pressure to mechanical movement causes an increase in the overall power losses and reduces the overall efficiency of the machine. Further, it has been found that these previous hydraulic types of switch machines are also susceptible to frequent failures due to leakages in the machine itself as well as in the conduits or pipes and hoses leading to and from the switch machine.

Since commercial electrical power is readily available through classification yards, it is therefore highly advantageous to directly employ an electric motor for power operating a trailable railway switch machine. In one previous attempt to provide an electrical power operated switch machine, the use of a manual switch stand has been combined with an electric motor. However, one serious shortcoming of this type of electrically powered switching device involves safety to the attending personnel. For example, it is necessary to positively lock or latch the hand throw lever in its extreme position in that the electric motor can drive and cause movement of an unlatched hand lever so that a switchman or maintainer could be seriously injured by the swinging lever when the machine is automatically operated.

Thus, such previous proposed power operated switches not only have been extremely costly to manufacture and maintain but also have been a constant hazard and danger to attending personnel.

Accordingly, it is an object of my invention to provide a new and improved trailable railway switch machine which alleviates the above-mentioned problems and shortcomings.

A further object of my invention is to provide an improved trailable railway switch machine which may be selectively operated in a power or manual mode of operation for moving the switch points between their extreme positions.

Another object of my invention is to provide an electrically powered railway switch machine which includes a hand throw lever that remains stationary during the movement of the switch points by the electric motor or during a trailing action by the wheels of passing railway vehicles.

Yet a further object of my invention is to provide a railway switch machine having a handlever for manual operation, an electric motor for power operation, and a motion translating mechanism for allowing trailing operation so that the switch points may be shifted between their extreme positions.

Still a further object of my invention is to provide a trailable switch mechanism having a box shaft which is selectively rotated by an electric motor through a gear train, a clutch and a pinion and rack or by a handlever through a toggle shaft, a link, a clevis and a pivot block to shift the switch points between their extreme positions.

Still another object of my invention is to provide an electric railway switch machine having a cutout switch device which cooperates with the hand throw lever to prevent automatic operation during manual operation.

Yet another object of my invention is to provide a railway switch machine having a motion translating mechanism which is capable of translating rotary motion to reciprocating motions so that the hand throw lever remains stationary during power operation and during trailing of the switch machine.

Still yet another object of my invention is to provide a high speed railway switch machine having a motor driven power train which remains stationary during a hand throwing operation and during trailing of the switch machine.

Still yet a further object of my invention is to provide a trailable railway switch machine which is economical in cost, reliable in operation, durable in use, efficient in service, and safe to attending personnel.

In accordance with the present invention, my unique railway switch includes a pair of switch points and an operating mechanism for moving the switch points between two extreme positions. The operating mechanism includes a rotatable box shaft having a slotted arm which is connected to the switch points by a cam roller carried by an operating rod. The rotatable box shaft is connected through a pivot block to a clevis. The clevis is pinned to a link which is pinned to a toggle shaft. A hand throw lever is directly connected to the toggle shaft. A compressive spring bracket assembly normally engages the toggle shaft and acts upon the link, the clevis, the pivot block and the rotatable box shaft to urge the switch points to either of their extreme positions. An electric motor is coupled to the box shaft through a gear train, an electric clutch, a pinion and rack having another cam roller engaging the slotted arm. When it is desired to move the switch points between their two extreme positions, the hand throw lever may be thrown or the electric motor may be energized. In manual operation, the throwing of the hand throw lever imparts rotary movement to the toggle shaft, the link, and the clevis. This rotary movement causes the pivot block to rotate the box spindle and slotted arm which, in turn, causes longitudinal movement to be imparted to the operating rod so that the switch points are moved from one to the other of their two extreme positions. The rotation of the hand throw lever is also translated to a reciprocating movement of the rack which causes the pinion to rotate but the clutch which is deenergized allows the gear train as well as the electric motor to remain stationary. Alternatively, when the electric motor is energized, rotary movement is imparted to the pinion through the gear train and energized clutch. This rotary movement of the pinion causes the rack to move longitudinally which is conveyed to the operating rod by the cam rollers and slotted arm. Thus, the switch points are also moved from one to the other of their two extreme positions. The movement of the slotted arm causes the box shaft to rotate but this rotary movement is translated to a reciprocating movement by the pivot block, clevis, link and toggle shaft so that the hand throw lever remains stationary. When the railway switch is trailed by a passing vehicle, the movement imparted to the switch points by the wheels of the vehicle causes the operating rod to move longitudinally. The movement of the operating rod is conveyed through its cam roller to the slotted arm. The movement of the slotted arm causes rotation of the box shaft and results in longitudinal movement of the rack by the cam roller and causes the pinion to rotate. The rotation of the pinion by the longitudinal movement of the rack is not conveyed to the gear train or motor since the clutch is deenergized. The

rotation of the box shaft is again translated to longitudinal movement of the toggle shaft by the pivot block, clevis and link. Thus, the hand throw lever as well as the electric motor and gear train remain stationary during a trailing action of the switch points by the wheels of a railway vehicle.

One form of the railway switch machine embodying the present invention will be described and the novel features and advantages thereof will be pointed out in the annexed claims.

The above objects and other attendant features and advantages of this invention will become more fully evident from the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a partially schematic view of a railway switch and a top plan view of the switch operating mechanism having its cover removed to show in more detail the various internal parts of the operating mechanism.

FIG. 2 is a sectionalized elevational view of the switch operated mechanism taken substantially along lines 11-11 of FIG. 1.

FIG. 3 is an end elevational view of the switch operating mechanism as externally viewed from the hand lever end.

Referring to the drawings, wherein like parts are indicated by like reference numerals in each figure, and in particular to FIG. 1, the reference character A schematically designates a right-hand railway switch layout with the left point closed. The railway switch includes two stock or fixed rails la and lb and two

movable switch points

2a and 2b. The fixed rails 1a and lb are normally placed on tie plates (not shown) which are secured in the usual well known manner to cross ties (not shown). The

movable switch points

2a and 2b are fastened together for simultaneous movement by a head rod 3. The switch may be defined as occupying its normal position when the movable switch point 2a engages the fixed rail 1a while the movable point 2b is spaced from the fixed rail lb, as illustrated in FIG. 1. Conversely, the switch may be defined as occupying its reverse position when the movable point 2b engages the fixed rail lb while the movable point 2a is spaced from the fixed rail la.

Cooperating with and suitably secured to cross ties 4, adjacent the outer side of the fixed rail 1b is a switch machine or operating mechanism B comprising a rectangular casing or frame 6 which supports and houses the internal components or parts of the mechanism. In viewing FIGS. 2 and 3, it will be noted that a cover 7 cooperates with the top of the frame 6 and includes, for example, a rubber gasket 7a, FIG. 2, which effectively seals the internal components of the mechanism from moisture, dirt and other foreign particles. As shown in FIG. 3, the cover 7 is removably attached to the casing 6 by a pair of hasps and staples generally indicated by

characters

12a and 12b each of which may be locked with a padlock to prevent unauthorized tampering with the switch mechanism. In viewing FIG. 1, it will be noted that the switch points are interconnected with the switch operating mechanism B and are moved between the normal and reverse positions by means of an operating or throw rod 8 which may be directly connected or indirectly connected by a push rod, a conventional switch basket (not shown) which is secured to the head rod 3. The operating bar 8 passes through a suitable opening provided in the back end of the casing '7. A flexible boot 9 is suitably attached to the exterior of the casing to prevent the entrance of dirt, moisture, and the like into the casing 7.

In viewing FIGS. 1 and 2, it will be noted that the switch mechanism B basically includes a substantially centrally located motion translating mechanism 14 and a power drive 15 and a manual operator 16 disposed on either end thereof.

As shown, the motion translating mechanism 14 includes a rotatable vertical box shaft 17 which is suitably disposed between the upper or top and lower or bottom extremes of the frame 6. The upper reduced cylindrical end of the box shaft 17 is journaled within an upper bearing 18 mounted in cross plate member 19. The cross plate member 19 is rigidly fastened to the top of frame 6. For example, one end of the cross plate member 19 is secured by bolts 20 to a first flange 21 which is welded to and extends laterally from the outer side wall portion 22. The other end of the cross plate member 19 is preferably forked or branched for providing increased stability. Each branch is secured by

individual bolts

23a and 23b to a pair of flange members 24 extending laterally from the front end wall portion 25. The bottom portion 26 of the frame 7 is provided with an upstanding central bushing or cylindrical bearing 27. The cylindrical bearing 27 is secured in a suitable manner, such as by welding, to the bottom of frame 7 and is adapted to accommodate the lower reduced cylindrical end portion of the box shaft 17. Thus, the upper and lower bearings 18 and 27 are arranged to rotatably support the spindle 18 about a vertical axis. As shown, the lower end of box shaft 17 includes a laterally extending slotted arm 28, the purpose of which will be described hereinafter.

The box portion 29 of the shaft includes a rectangular opening 30 for accommodating a pivot block 31. The pivot block 31 is pivoted about a horizontal axis by a pair of pins 32a and 32b, the ends of which extend into apertures provided in the sides of the box portion 29. The ends of pin 32 may be securely held in place by rivets or the like (not characterized) so that the pivot block 31 is free to rotate in a vertical plane but not in a horizontal plane with respect to the box shaft 17. A clevis 33 including a reduced portion 34 passes through a central circular opening provided in pivot block 31. A split retaining ring 35 is disposed within an annular groove located in the remote end of the reduced portion 34 so that the clevis 33 is maintained in place and allowed to rotate with respect to the pivot block 31. The perforated U-shaped portion of clevis 33 receives one end of a link 36. The one end of link 36 is pivotally connected to the U-shaped portion of clevis 33 by a pivot pin 37. The other end of link 36 is interfitted with a U-shaped portion 38 of hand lever toggle 39. The link and toggle are held in pivotal relationship by means of pivot pin 40. The other end of the hand throw toggle 39 includes a splined shank or shaft 41 which is fitted within an agreeing splined portion of hub 42. The hub 42 is journaled within a sleeve bearing 43 formed in the end wall of the frame 7. Thus, the hand throw toggle shaft moves longitudinally with respect to the hub 42 and also rotates therewith, as will be described hereinafter. A hand throw lever 43 is spline fitted onto the shaft end of toggle 39 and is retained in place by a split retaining ring 44 which is disposed within an annular groove formed in the end of shaft 41.

A suitable spring biasing arrangement normally urges the hand throw toggle 39 to a retracted position, as depicted in the drawings. The biasing arrangement includes a longitudinally movable bracket 48 which is guided by a pair of L-shaped channel members 50 and 51 secured to the respective side walls of frame 6. A pair of helical springs 52 and 53 normally urge the hand throw toggle 39 and bracket 48 to a retracted position as shown in FIGS. 1 and 2. As shown, the toggle shaft 41 passes through a circular opening 54 centrally located in the movable bracket 48. In viewing FIG. 2, it will be noted that the toggle 39 is provided with a collar 55 which engages and communicates with an annular recess 56 formed about opening 54. Thus, the toggle 39 is permitted to rotate relative to the bracket 48 but moves longitudinally with the bracket 48 between an extended and the retracted position. Further, a pair of open-ended cylindrical spring retainers 57 and 58 accommodate one end of the springs 52 and 53, respectively. The other end of each of the helical springs is confined by dish-shaped members (not characterized) formed on the inner surface of end wall 25. A pair of through bolts 59 and 60 are adapted to pass through the ends of circular spring retainers 57 and 58, respectively, as well as through the center of springs 52 and 53. One end of the bolts 59 and 60 is located in holes in the end wall 25 of the frame 6. A pair of nuts threadedly engage the other ends of the through bolts 59 and 60 and are used for assembly and maintenance purposes. Thus, the bolts and nuts retain the bracket 48 and springs 52 and 53 in the proper position with each other. The dual-spring assembly and shaft portion 41 of the hand throw toggle 39 provide a very stable arrangement so that the bracket 48 moves freely without binding and shafting.

In viewing FIGS. 1 and 3, it will be noted that the hand throw lever 43 is shown resting in a horizontal position atop a stop member 64 which is secured to the side of the casing 6. A similar stop member 65 is secured, such as by welding, to the other side of the case or frame 6 and limits the amount of rotation in the other direction that the hand throw lever 43 may be moved. The hand throw lever 43 is locked in either one of the two horizontal positions by a locking plate 67 which is pivotally connected to the outer surface of the front wall 25 of frame 6. A staple 68 is also preferably secured to the front end 25 of frame 6 and is adapted to pass through a rectangular opening provided in the lock plate 7. Thus, a padlock (not shown) may be inserted through the staple 68 to prevent tampering or inadvertent manual operation by unauthorized personnel. The lock plate 67 also functions as an interlocking device which precludes the switch mechanism from being both manually and power operated at the same time. For example, when the locking plate 67 is in its vertical position as shown in the drawings, the hand lever 43 cannot be thrown since the upper surface of the plate cooperates with the under side of lever 43 to prevent movement thereof. Conversely, when the padlock is removed and the lock plate is pulled outwardly as viewed in FIG. 3, a power disabling effect occurs to prevent automatic operation of the switch mechanism so that the switch mechanism may only be manually operated. Further, when the lock plate is flipped forward, the upper surface of the lock plate 67 does not impede movement of the hand lever 43 so that the lever may be manually thrown opposite the horizontal position to engage the stop member 65. The power disabling action is carried out by a motor cutout switch 70 which permanently interrupts the motor energizing circuit while the lock plate 67 remains in its pulled away inclined position. The switch 70 is illustrated as a conventional miniature switch which includes a roller operated lever 71 which controls a pair of internal electrical contacts to open and close the control circuit. As shown in FIG. 1, the roller lever 71 cooperates with a cam surface 72 which depresses or releases the lever to control the electrical cutout contacts. In the position shown in the drawings, the roller 71 is engaging the high part of the cam 72 so that the lever is released and the electrical contacts are closed. The cam 72 is secured to one end of a slide bar 73 which passes through aligned openings in a slide bracket 74 fixed to the bottom of the frame 6. The other end of the slide bar 73 includes an upstanding vertical portion having an aperture formed near the end thereof. One end of a push rod 75 passes through the aperture and is securely held thereto by a pair of nuts which allow for any necessary adjustments. The other end of the push rod is connected to a pivot pin 76 extending laterally from the lower end of the lock plate 67, as shown in FIG. 3. A retaining ring 77 or the like securely holds the push rod 75 onto the pin 76. Thus, when the lock plate 67 is flipped outwardly the push rod 75 and slide rod 73 move the cam 72 forward toward the front end of the frame 6. This causes cam 72 to depress the roller lever 71 and in turn causes the electrical contacts to open thereby interrupting the control circuit and preventing automatic operation of the mechanism.

It will be noted that the radial extending arm 28 of box shaft 17 includes an elongated slot 80 formed in the under side thereof. As shown, the slot 80 accommodates and coacts with a pair of cam rollers 81 and 82. The cam roller 81 is secured to an upstanding pin provided on the end of operating rod 8. The operating rod 8 is slightly elevated above the bottom surface 26 of the case 7 by a pair of bearing blocks 84 and 85. Thus, it will be appreciated that any rotational movement imparted to the box shaft 17 will be translated to longitudinal movement of the operating rod 8 and vice versa. As shown, the cam roller 82 is also secured to an upstanding pin provided on one end of rack 86. The rack 86 includes gear teeth formed along its upper side which are adapted to mesh with the gear teeth of pinion 87. The pinion gear 87 is situated between a pair of intcrmediately

disposed walls

88 and 80 and is secured to one end of pinion shaft 90. The shaft 90 is disposed within a pair of

bearings

91 and 92 which are disposed within the

walls

88 and 89, respectively. As shown, the

walls

88 and 89 also function as a guide for rack 80 which also is confined by and slides within the bearing block 84 located at the back end of frame 6. Thus, any rotational movement imparted to the box shaft 17 is also translated to longitudinal movement of the rack 86 and vice versa. The other end of pinion shaft 90 is keyed to the hub of the armature plate 91 of an electromagnetic clutch 92. The electromagnetic clutch 92 is electrically connected to a suitable source of dc power during the power operating mode. Normally the armature plate 91 is disengaged from the clutch field magnet 93 so that no movement can be imparted to the clutch field magnet 93 unless the clutch is energized. The slip rings and clutch field hub 93 are keyed to one end of the output shaft of gear train 94. The output shaft is rotatably supported by bearings 95 and 96 which are disposed within the side walls of a gear box 97. An output gear 98 is disposed between the wall of gear box 97 and is carried by the output shaft. The output gear 98 is driven through a plurality of intermediate gears (not characterized) which, in turn, are driven by an input gear 99. The input gear 99 is attached to the exposed end of drive shaft 100 of a three phase reversible electric motor 101. The motor 101 is securely fixed, such as by being bolted, to one of the side walls of gear box 97. The electric motor 101 is appropriately energized by a conventional 220 or 440 voltage source of an ac. power supply which is remotely controlled for power operations. With an average gear ratio of approximately 230:1 an operating time of approximately two seconds is achieved. Further, the high gear ratio of the gear train only requires that one horsepower motor be employed for effectively driving the switch points between their extreme positions. As shown, all of the critical components or parts of the railway switch mechanism B are internally located within the frame 6, and therefore, are not exposed to the adverse conditions normally present in a railroad environment.

Now assuming that all the necessary adjustments have been made and that the railroad switch is operating properly, I will describe the various alternative methods of operating the switch from its normal position, as shown in the drawings, to its reverse position. As previously mentioned, the switch points may be selectively moved from one extreme position to the other extreme position in one of three ways, namely, power driving the switch points by energizing motor 101, manually moving the switch points by throwing the hand throw lever 48 or trailing the switch points by the wheels of a vehicle passing through the switch by moving the operating rod 8.

First let us assume that the switch points are to be moved automatically from their normal to their reverse position by energizing the reversible electric motor 101. As previously mentioned, automatic operation of the switch machine may be under the control of a computer or a yardmaster remotely located from the site of the railway switch. When the control circuit is closed, both the motor 101 and the clutch 92 become energized. The energization of the reversible motor 101 causes rotational movement of the armature and its shaft 100 and in turn causes high speed rotation of the gear 99. The rotation of the input gear 99 is transmitted through and reduced by the gears so that the output gear 98 rotates at a relatively low speed. The rotation of the gear 98 is coupled to the pinion gear 87 by clutch 92 which is energized so that the armature causes the clutch plate to engage the slip ring and cause the shaft 90 to rotate. The rotary movement of the gear 87 imparts longitudinal movement to the rack 86. In the present instance, the rack 86 is moved to the right, as viewed in FIGS. 1 and 2. The longitudinal movement is transmitted through the cam roller 82 and slotted arm 28 to cause counterclockwise rotation of the box shaft 17. The counterclockwise rotation of the box shaft 17 causes the slotted arm to pull and move the operating rod 8 to the right. Thus, the switch points 2a and 2b begin moving from their normal to their reverse position. The counterclockwise rotation of the box spindle 18 also causes planar horizontal movement to be'imparted to the clevis 33 through pivot block 32. The planar horizontal movement of the clevis 33 also causes lateral movement to be imparted to the intermediate link 36. That is, the link 36 is caused to move in a planar lateral direction rather than to move in an arcuate angular direction. This planar horizontal movement of the intermediate link 36 is transmitted through pivot pin 40 to the hand throw toggle 39. Accordingly, the hand throw toggle 45 begins moving longitudinally with respect to the axis of the shaft 42. The longitudinal movement of the toggle 39 also causes movement of the bracket 48 which results in the depression of the helical springs 52 and 53. As the motor continues to rotate and turn the box shaft 17, the slotted arm 28 continues to move the switch points 2a and 2b from their normal to reverse position and the hand throw toggle 39 continues to move bracket 48 which, in turn,

depresses the springs 52 and 53. When the switch points assume their intermediate position, the helical springs 52 and 53 will be substantially fully depressed by bracket 48. Thus, the splined shank portion 42 of the hand throw toggle 39 will be extended outwardly by an amount equal to the horizontal displacement of the bracket 48. At this instance, the longitudinal axis of the clevis 33, the intermediate link 36 and hand throw toggle shaft 42 are in a straight line relationship. As the motor 101 continues driving the box shaft 117, and as the hand throw toggle 45, the intermediate link 36 and the clevis 33 move past dead center, the remaining movement is nowassisted by the stored energy in the biasing springs 52 and 53. Normally, the motor 101 and clutch 92 will remain energized until the cam 102 carrying the arcuate section 103 of box shaft 17 engages the roller lever 104 which controls a motor limit switch mounted within the housing of miniature switch 70. As shown, an adjustable cam 105 and roller lever 106 operate as a motor limit switch to control the deenergization of the motor and clutch in clockwise rotation of the box shaft 17. The switch points are moved the remaining distance by the inertia of the mechanism and by the compression springs 52 and 53 until the switch point 2b intimately contacts stock rail 1b. However, it will be appreciated that in case an obstruction prevents the switch points from assuming the reverse position, the reverse control circuit may be interrupted and the normal control circuit may be energized to return the switch points to their normal position. Thus, it can be seen that a rotational input from the motor 101 imparts a rotational movement to the shaft 17 and imparts a reciprocating movement to the hand throw toggle 39.

the rack 86 and operating rod 8 through the cam rollers 81 and 82 and slotted arm 28. The rotational movement of the box shaft causes lateral movement of the clevis and intermediate link 41 which in turn causes a reciprocating movement of the hand lever toggle 39. Again, the hand throw lever 43 remains stationary on the stop member 64 and the switch machine moves through its procedure operation until again the switch mechanism assumes the position as shown in the drawings and the switch points again assume their position as shown in FIG. 1.- Thus, it can be seen that attending personnel are not in danger and cannot be injured by the hand throw lever 43 during power operation of the railway switch machine. If during either normal or reverse operation, the switch points are trailed by the wheels of a passing vehicle, the clutch 92 slips so that no damage is caused to the switch machine.

Let us again assume that the railway switch is in its normal position as shown in FIG. 1 and that it is now desirable to manually manipulate the switch points to their reverse position. Under this condition, a yardman or switchman simply throws the hand throw lever 43 from the stop member 64 toward stop member 65. However, before the hand lever 43 can be thrown, the authorized individual may remove the padlock and pull back the lock plate 67 to allow clearance for the hand throw lever. The manipulation of the lock plate 67 moves the rods and 73 which in turn causes the cam 72 to depress the roller lever 71. The depression of the roller 71 interrupts the electrical cutout contacts of the control circuit so that energization of the electrical motor 101 cannot take place during manual operation of the switch mechanism. It will be noted that the manual throwing of the hand lever 43 causes rotational movement to be imparted to the hand throw toggle 39. The rotational movement of the hand throw toggle 39 now causes arcuate angular rotation of the intermediate link 36 and clevis 33 which imparts a counterclockwise rotary movement to the box shaft 17 through pivot block 32. The counterclockwise rotational movement is obviously conveyed to the slotted arm 28 which again causes longitudinal movement to the operating rod 8. The rotational movement of the slotted arm 28 also causes the rack 86 to move longitudinally which, in turn, causes rotation of the pinion gear 87 and shaft 90. However, since the clutch 92 is not energized, the armature plate 91 does not engage the clutch field magnet 93 but rotates freely. Such operation insures that extra effort is not required by the operator to overcome the dead weight of the clutch plate and armature as well as the gear train and motor.

It will be appreciated that the procedure for moving the switch points from their reverse to normal position is substantially the same with the exception that the hand throw lever is moved from the stop member 65 back to the stop member 64. The hand lever toggles and link clevis and pivot block undergo similar movement, namely, the hand throw toggle 39, link 36 and clevis 33 rotate angularly while the pivot block 31 pivots about pins 32a and 32b. The pivot block 31 also rotates with the box shaft 17 and causes the slotted arm to turn therewith. The rotary movement is conveyed through roller 81 to cause the operating rod 8 to move the switch points back to their normal position. Thus, it will be seen that the rotational input to the hand throw lever 43 imparts a rotational movement to the box shaft 17 which is translated to a reciprocating movement of the throw rod 8. Further, it will be noted that the toggle 39 rotates within the annular recess 56 of bracket 48 so that the spring bracket assembly does not move and therefore extra effort need not be exerted for compressing the biasing springs 52 and 53.

Let us again assume that the railway switch is in its normal position as shown in FIG. 1 and that a railway vehicle is approaching the switch position on stock rail la and switch point 2b. Under this condition, a trailing action will occur and the forward wheels of the vehicle will shift the switch points from their normal to reverse position as the vehicle passes through the switch. The lateral movement of the switch points causes longitudinal movement of the operating bar 8 which in turn is translated by roller 81 and slotted arm 28 and causes rotational movement of the box shaft 17. The rotation of the box shaft 17 causes longitudinal movement of the rack 86 through roller 82 and the slotted arm 28. Since the clutch 92 is deenergized, the rotational movement imparted to gear 87 and shaft 90 has no effect on the gear train and motor 101. Further, it will be noted that rotation of the box shaft 17 causes the hand throw toggle linkage to simply reciprocate between the normally extended and retracted positions. That is, the

rotational movement of the box shaft 17 and, in turn, rotation of the clevis 33 causes the intermediate link 36 to undergo a planar horizontal movement. Again, the planar movement of the clevis and link causes reciprocating movement to occur in the hand lever toggle 39. Thus, a rotational input movement to the box shaft 17 by a trailing action of the railway switch simply causes reciprocating movement to occur in the hand throw toggle 39. Thus, when the front wheels of a railway vehicle trail the railway switch, a maintainer is not exposed to any danger of a swinging hand throw lever, and no damage will occur to the gear train or electric motor. The switch points are held in their trailed position by the tension of the helical springs 52 and 53 so that no slapping action with the stock rails occurs due to the passage of the subsequent wheels of the railway vehicle.

From the foregoing, it will be seen that the presently described railway switch machine provides a more efficient mechanism for moving the switch points between their two extreme positions. It will also be seen that the switch mechanism provides a reliable method of moving the switch points between their two extreme positions with a minimum of losses due to the elimination of imparting or attempting to impart movement to dead weights. For example, during power operation, the hand throw lever 43 remains stationary so that unnecessary power is not consumed in moving or attempting to move the lever from one position to the other position. Similarly, during manual operation no movement is imparted to the gear train and in turn to the motor due to the disengagement of clutch 92. Similarly, less chance of injury to personnel is realized in that no movement or torque is applied to the hand lever 43 and less danger of damage to the power drive train is realized due to the elimination of rotational torque to these portions of the switch mechanism. Thus, a more efficient and safer switch machine is realized by insuring that rotary input movement to the manual or power inputs simply result in rotary output to the switch crank arm, and that rotary input to the switch crank arm results in the reciprocating movement to the manual and power inputs.

Although I have herein illustrated and described only one form of apparatus embodying my invention, it is understood that various changes, alterations, and modifications may be made by those skilled in the art which fall within the realm and scope of the claims of the invention.

For example, it will be appreciated that the various parts of the switch mechanism B may be separate entities which are housed in distinct or individual casings rather than a single protective casing. That is, the power drive and the motion translating mechanism and manual operator which operate as a switch stand may be separated and enclosed in individual protecting housings.

Having thus described my invention, what I claim is:

1. A railway switch machine for moving switch points between their extreme positions comprising, an electric motor for power operating the switch points between their extreme positions, a gear train in driving engagement with said electric motor, a pinion and rack, a clutch interposed between said gear train and said pinion, an operating rod having one end connected to the switch points, a motion translating mechanism interconnecting said rack to the other end of said operating rod, a handlever connected through said motion translating mechanism to said other end of said operating rod for providing an optional method of manually throwing the switch points to either of their extreme positions and said motion translating mechanism including a toggle shaft and a spring bracket assembly which moves longitudinally relative to said handlever so that no movement is imparted to said handlever during power operation or trailing action of the switch machine.

2. A railway switch machine as defined in claim 1, wherein said clutch slips so that said electric motor remains stationary and a toggle linkage ensures that said handlever remains stationary when the switch points are trailed by the passing wheels of a railway vehicle.

3. A railway switch machine as defined in claim 1, wherein said motion translating mechanism includes a rotatable box shaft which translates rotary movement of said electric motor and said handlever to longitudinal movement of said operating rod.

4. A railway switch machine as defined in claim 3, wherein said box shaft includes an arm having an elongated slot which receives a pair of rollers carried by slide bars attached to said rack and to the other end of said operating rod.

5. A railway switch machine as defined in claim 1,

wherein said spring bracket assembly includes a pair of cylindrical sockets for receiving helical springs through each of which passes a threaded bolt having an adjusting nut for setting the tension on said helical springs.

6. A railway switch machine as defined in claim 1, wherein said motion translating mechanism includes a toggle shaft, a spring bracket assembly through which said toggle shaft passes, a box shaft, a link, clevis and pivotaLblock interconnecting said toggle shaft to said box shaft, said shaft including a radially extending slotted arm, a first slide bar forming part of said rack, a second slide bar forming part of said operating rod, each of said slide bars having a roller slidably engaging said slotted arm so that longitudinal movement is imparted to said operating rod when said electric motor is energized or said handlever is rotated.

. 7. A railway switch machine as defined in claim 1, wherein said clutch is arranged to slip so that said gear train and said electric motor does not rotate during manual operation and trailing action of the switch

Claims

5. A railway switch machine as defined in claim 1, wherein said spring bracket assembly includes a pair of cylindrical sockets for receiving helical springs through each of which passes a threaded bolt having an adjusting nut for setting the tension on said helical springs.

6. A railway switch machine as defined in claim 1, wherein said motion translating mechanism includes a toggle shaft, a spring bracket assembly through which said toggle shaft passes, a box shaft, a link, clevis and pivotal block interconnecting said toggle shaft to said box shaft, said shaft including a radially extending slotted arm, a first slide bar forming part of said rack, a second slide bar forming part of said operating rod, each of said slide bars having a roller slidably engaging said slotted arm so that longitudinal movement is imparted to said operating rod when said electric motor is energized or said handlever is rotated.

7. A railway switch machine as defined in claim 1, wherein said clutch is arranged to slip so that said gear train and said electric motor does not rotate during manual operation and trailing action of the switch machine.

8. A railway switch machine as defined in claim 6, wherein the compressive force of said spring bracket assembly is transmitted through said toggle shaft and said box shaft to said operating rod to effectively hold the switch points in their extreme positions.

9. A railway switch machine as defined in claim 1, wherein an interlocking cutout device including a cam operated switch, an operator rod assembly and locking block are associated with said handlever to prevent energization of said electric motor during manual throwing of the switch points.