Abstract:
A railroad switch machine which is normally operated by an electric motor but which may be manually operated without causing rotation of the power shaft of the electric motor to enable the switch machine to move the switch points without having to overcome the brake resistance applied to the power shaft by the brake and gearbox thereof.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates generally to railroad yard switch machines, and more particularly to an improved switch machine which may be electrically operated or manually operated, provides run-through capability, and has fewer moving parts than existing switch machines.  
         [0003]     2. Description of the Related Art  
         [0004]     Machines using hydraulic, pneumatic, or electrical energy to move railroad switch points to remotely or locally change the route of trains have been used for many years. These devices have been very useful for allowing remote operators to control the movement of trains on main lines and side tracks and also for distribution of railroad cars in railroad switch yards.  
         [0005]     Within recent years, the use of powered railroad switch movement devices (switch machines) has increased in railroad switch yards as a means of preventing debilitating strains and back injuries to personnel which sometimes results from use of manually-operated switch movement devices (manual switch stands).  
         [0006]     One problem with prior art switch machines is the large number of parts, and especially moving parts, thereby requiring frequent maintenance and repair. In addition, typical switch machines utilize gears which can be damaged by vibration of the switch points as railroad cars roll through the switch. Prior art powered switch machines also typically require two motor control relays to permit reversing the direction of a motor to operate the switch machine in opposing directions. These two such relays needlessly increase repair frequency and maintenance costs.  
         [0007]     A further problem with conventional switch machines, whether powered or manual, resides in the back injuries sustained during manual operation of such switches. The strain placed on the lower back of a railroad employee while attempting to operate the switch is substantial, and leads to frequent injuries and disabilities.  
         [0008]     Applicant solved a large number of the problems in the prior art by way of the invention described in U.S. Pat. No. 6,164,601. In applicant&#39;s earlier invention, an improved switch machine was provided where special locking detection features for high-speed main lines were not required. Applicant&#39;s earlier invention also provided a switch machine with fewer moving parts and simpler design than existing technology, permitting maintenance-free operation and lower cost. Applicant&#39;s earlier invention was also designed to directly replace most of the popular manual switch stands or machines without need for replacing or moving the switch ties, thereby simplifying installation.  
         [0009]     Applicant&#39;s earlier invention includes a unique mechanism which allows the switch points to be moved in either direction without having to reverse the direction of the motor thereby only requiring one motor control relay instead of two required by the prior art existing electric switch machines. The mechanical mechanism of applicant&#39;s earlier patent for moving the switch points was designed to provide a point moving force which follows a general bell curve, to thereby initiate and complete the switching movement at slow speed, with a higher speed movement in the middle of the switching cycle.  
         [0010]     Applicant&#39;s earlier invention also contains a spring-loaded mechanical release which will prevent damage to the motor and crank mechanism if the points of the switch are prevented from moving by a foreign object or if a train moves through the switch when the points are in the wrong direction and forces the points to the other position (trailed through or run through). Applicant&#39;s earlier mechanical release was designed to cause the vertical shaft to hold the points in position as long as the motor is in its stopped position, regardless of correspondence between the crank mechanism position and the position of the points.  
         [0011]     Applicant&#39;s earlier invention contained a hand-throw lever device which may be used to disengage the crank mechanism from the vertical shaft to permit manual movement of the switch points if electrical power is lost or the motor or crank mechanism fails. Provision was made to allow the switch points to be locked in position using the hand-throw lever if it is desired to prevent remote movement of the switch points by activation of the motor and crank mechanism.  
         [0012]     Although the invention of applicant&#39;s earlier patent has met with considerable success, some concern has been raised as to the position of the hand-throw lever when it is manually operated since the lever extends outwardly from the machine. Despite the success of applicant&#39;s earlier invention, it is believed that the present invention represents a significant improvement over the earlier invention in that a different spring arrangement is utilized in the instant invention and it is believed that the operation of the hand-throw lever device is much easier than applicant&#39;s earlier machine. Further, in the instant invention, there is no need to disengage the cam follower assembly from the orthogonally mounted plate on the shaft as in applicant&#39;s earlier invention.  
       SUMMARY OF THE INVENTION  
       [0013]     A railway switch machine having a reciprocating throw rod extending therefrom for operating the points of a railway track switch is described which includes a housing having a base plate for supporting the switch machine. The base plate has an opening formed therein which receives a vertically disposed shaft, having upper and lower ends, extending therethrough with the lower end thereof being operably connected to the throw rod. The vertically disposed shaft is rotatable to reciprocate the throw rod to open and close the switch points. A first plate, having an upper surface, is mounted on the vertically disposed shaft for rotation therewith and the upper surface thereof has a plurality of radially spaced grooves and ridges formed therein. A cam follower assembly, having upper and lower ends, is slidably and rotatably mounted on the vertically disposed shaft above the first plate. The cam follower assembly includes a pair of cam followers at its lower end for engagement with oppositely disposed grooves and ridges. A spring means is provided on the vertically disposed shaft above the cam follower assembly to apply a biasing force downwardly on the cam follower assembly. The biasing force yieldably maintains the cam followers within the grooves formed in the upper surface of the first plate. A DC or AC motor is mounted in the housing and has a horizontally disposed and rotatable power shaft extending therefrom with the power shaft only being rotatable in a first direction by the motor. The motor includes a brake which resists the rotation of the power shaft unless the motor is energized.  
         [0014]     A horizontally disposed and rotatable hand throw shaft is positioned in the housing in manner which is parallel to and spaced laterally from the power shaft. A drive gear is mounted on the hand throw shaft for rotation therewith and hinge assembly a hand throw handle secured thereto which is positioned outwardly of the housing. The hand throw handle or lever is selectively movable between first and second positions. A driven gear is operably freely rotatably mounted on the power shaft and is in mesh with the drive gear. A crank plate is mounted on the power shaft with a first clutch operably connecting the crank plate to the power shaft. The crank plate is operably connected to the cam follower assembly whereby rotation of the crank plate by the power shaft causes the vertically disposed shaft to reciprocate the throw rod. The first clutch permits the crank plate to rotate on the power shaft in the first direction without rotating the power shaft of the electric motor when rotational force is applied to the crank plate by means other than the power shaft. A second clutch connects the driven gear to the crank plate with the second clutch permitting the crank plate to rotate in the said first direction without causing the rotation of the driven gear in the first direction when the power shaft rotates the crank plate in the first direction. The second clutch causes the crank plate to rotate in the first direction when rotational force is applied to the crank plate by the driven gear rotating in the first direction. The first and second clutches enable the switch points to be moved by means of the hand throw handle and hand throw shaft without rotating the power shaft of the motor if the motor cannot be energized.  
         [0015]     These and other objects will be apparent to those skilled in the art. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is a perspective view of the switch machine of this invention and the switch points associated therewith;  
         [0017]      FIG. 2  is a top view of the switch machine and the switch points;  
         [0018]      FIG. 3  is an exploded perspective view of a portion of the switch machine;  
         [0019]      FIG. 4  is a top elevational view of the switch machine with the cover thereof removed;  
         [0020]      FIG. 5  is an exploded perspective view of a portion of the switch machine;  
         [0021]      FIG. 6  is an exploded perspective view of a portion of the switch machine;  
         [0022]      FIG. 7  is a perspective view of the wave plate, cam follower assembly, target post base, etc.  
         [0023]      FIG. 8  is an exploded perspective view of the electric motor of the switch stand and some of the associated structure;  
         [0024]      FIG. 9  is a sectional view of the upper portion of the target post base and associated structure;  
         [0025]      FIG. 10  is a partial sectional view illustrating the relationship of the drive gear, driven gear, clutch plate and lock plate, etc.; and  
         [0026]      FIG. 11  is a side view illustrating the manner in which the machine is connected to the connecting rod which is pivotally connected to the throw rod extending to the switch points. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]     The numeral  10  refers generally to the switch machine of the present invention mounted on switch ties  12  using track spikes, drive screws or bolts  14  driven through holes in the tie mounting plates  16  which are secured to and extend from the base plate or bottom wall  18  of housing  20  which has covers or lids  22  and  24  enclosing the open upper end thereof. Base plate  18  is provided with an opening  26  formed therein through which extends a vertically disposed and rotatable shaft  28 .  
         [0028]     The lower end of shaft  28  has an internally threaded bore  29  which extends horizontally therethrough and which threadably adjustably receives the threaded end of a crank eye  30  which has one end of connecting rod  32  secured thereto by means of a pivot bolt  33  ( FIG. 11 ). The other of connecting rod  32  is pivotally connected to the throw rod  34  extending from the switch points  35 A and  35 B. Shaft  28  is provided with a wave plate  36  having an upper surface which is provided with alternating grooves  38  and ridges  40  therebetween ( FIG. 6 ).  
         [0029]     The numeral  42  refers to a cam follower assembly having a central bore  44  which rotatably and slidably receives the upper end of shaft  28 . The lower end of cam follower assembly  42  is provided with a pair of spaced-apart rotatable cams or rollers  46  and  48  which are rotatably mounted thereon. One end of the cam follower assembly  42  has an upstanding crank post  47  as will be described in more detail hereinafter. When the cam follower assembly  42  is mounted on the shaft  28 , the cams  46  and  48  normally reside in a pair of oppositely disposed grooves  38 .  
         [0030]     A plurality of Bellville springs  50  are positioned on the upper end of shaft  28  in a plurality of sets of two. The springs  50  in each set of springs are oppositely disposed. In other words, the bottom-most spring in each set of springs will face upwardly while the upper spring in each set will face downwardly.  
         [0031]     The numeral  52  refers to a pressure plate having an opening  54  formed therein which receives the upper end of the shaft  28 . The lower end of the opening  54  has a reduced diameter which defines a shoulder therein which prevents the head  56  of bolt or screw  58  from extending therethrough. The lower end of bolt or screw  58  is externally threaded and is adapted to be threadably received by the internally threaded bore  60  of shaft  28 . Bracket  62  extends laterally from pressure plate  52  and has an arcuate support  64  secured to the outer end thereof. When the screw  58  is tightened into the internally threaded bore  68 , the pressure plate  52  applies pressure to the Bellville springs  50  to yieldably maintain the cams  46  and  48  in oppositely disposed grooves  38  in wave plate  36  so that rotation of cam follower assembly  42  will cause rotation of the wave plate  36  and shaft  28 .  
         [0032]     Bridge plate  66  is secured to and extends across the open upper end of the housing  20  and has an opening formed therein which registers with the upstanding riser tube  68  ( FIG. 7 ). The upper end  67  of pressure plate  52  is received within the riser tube  68  with a bushing  70  being positioned therebetween. Target post cap  72  is positioned on cap gasket  74  which is positioned on the riser tube  68  with the lower end of post cap  72  rotatably embracing the upper end of the riser tube  68 . Target post cap  72  is secured to the upper end of the pressure plate  52  by bolts or screws for rotation therewith. Target post base  76  is secured to the upper end of the target post cap  72  by screws or bolts. Target  78  is secured to the target post base  76  and extends upwardly therefrom in conventional fashion to advise the workers whether the switch is open or closed.  
         [0033]     The numeral  80  refers to an AC or DC electric motor secured to the base plate  18  and includes a power shaft  82  extending therefrom. Motor  80  includes a brake  84  which prevents rotation of the shaft  82  unless the motor  80  is energized. Motor  80  is a non-reversible motor and rotates in a counterclockwise direction as viewed from the brake end of the motor. Motor  80  also includes a conventional gearbox assembly  83 . A tapered bearing  86  is mounted on power shaft  82  for rotation therewith. The outer periphery of tapered bearing  86  includes a plurality of radially spaced cam surfaces  88  which extend into the tapered bearing  86  and which terminate in shoulders  90 . Driven gear  92  is freely rotatably mounted on the inner end of the tapered bearing  86 . The outer face of driven gear  92  is provided with a pair of oppositely disposed sprag pockets  94  formed therein, each of which are adapted to receive a conventional sprag  96  therein ( FIG. 5 ).  
         [0034]     The numeral  98  refers to a crank plate having an outer peripheral surface  100 , an inner ring-shaped surface  102 , inner face  104  and outer face  106 . Inner face  104  is also provided with a pair of oppositely disposed sprag pockets  108  milled therein which are adapted to receive the spring-loaded sprags  96  therein. A pair of openings  110  extend inwardly from outer face  106  of crank plate  98  and communicate with the sprag pockets  108  ( FIG. 5 ). A spring  112  is positioned in each of the openings  110  to urge the sprags  96  towards the sprag pockets  94  in gear  92 . The sprag pockets  94  and  108  and the sprags  96  are designed to act as a sprag clutch between the driven gear  92  and the crank plate  98  as will be explained in more detail hereinafter.  
         [0035]     Crank plate  98  has a plurality of bores  114  extending between surfaces  100  and  102 , each of which receives tubular dowels or sprags  116  therein. The number of bores  114  will correspond to the number of cam surfaces  88  formed in tapered bearing  86 . Springs  118  are positioned in the bores  114  outwardly of the sprags  116  and are maintained therein by Allen screws  119  or the like so that the springs  118  urge the dowels or sprags  116  into yieldable engagement with the cam surfaces  88 . The springs  118 , in cooperation with the cam surfaces  88 , act as a clutch between the tapered bearing  86  and the crank plate  98 , as will be described in more detail hereinafter. Notch or lock ring  120  embraces crank plate  98  and is secured thereto by means of set screws extending inwardly through the notch ring  120  and being threadably received by threaded bores in the outer peripheral surface  100  of crank plate  98 . Notch ring  120  has a pair of spaced-apart notches  122  formed in the peripheries thereof. Retainer  124  is positioned adjacent the outer face of crank plate  98  and is secured to tapered bearing  86  by screws or the like and is secured to power shaft  82  by a key or the like. As seen in the drawings, crank plate  98  has a crank shaft  126  extending outwardly therefrom. One end of an adjustable rod eye  128  is rotatably, pivotally and swivelly connected to crank shaft  126 . The outer end of crank shaft  126  is rotatably secured to one end of a pivot arm  130  which is rotatably mounted on a shaft  136  extending inwardly from a bearing  132  secured to the end wall of housing  20 . Adjustable rod eye  128  is rotatably secured, at its other end, to the post  47  which extends upwardly from one end of cam follower assembly  42 .  
         [0036]     Hand throw shaft  136  rotatably extends into the housing  20  and has its opposite ends received by and rotatably supported in suitable bearings secured to the housing. Hand throw lever  138  extends transversely from the outer end of shaft  136  and is selectively movable from a horizontally disposed position closely adjacent the housing  20  to a position extending upwardly therefrom. A drive gear  140  is mounted on shaft  136  within housing  20  for rotation with the shaft  136  and is in engagement or mesh with gear  92 . The lower end of pivot plate  142  is pivotally mounted on shaft  136  and has a roller  143  mounted at its upper inner end which rolls upon the outer periphery of the notch ring  120 . Spring  144  yieldably urges the pivot plate  142  towards the notch ring  120  to ensure the engagement of the roller  143  with the notch ring  120 . Bracket  146  extends upwardly from the pivot plate  142  and moves therewith so as to move into and out of one end of a proximity switch  148  secured to the inner surface of housing  20 .  
         [0037]     The numeral  154  refers to a proximity mount having a semi-circular bracket  156  at the upper end thereof which has proximity switches  158  and  160  adjustably mounted thereon. A proximity actuator assembly  162  is mounted on the upper end of shaft  28  for rotation therewith and has a pair of spaced-apart actuators  164  and  166  mounted thereon which are adapted to actuate switches  158  and  160 , respectively. The actuators  164 ,  166  and switches  158 ,  160  are selectively adjusted so that switch  158  will be actuated when the switch points have reached their closed position and so that switch  160  will be actuated when the switch points have reached their open position.  
         [0038]     Assuming that the switch points are in their open position, the machine  10  operates (electrically) as follows to close the switch points. The start button for the motor  80  is depressed momentarily to energize or activate the motor  80  so that power shaft  82  rotates in a counterclockwise direction as viewed from the rear of motor  80 . As power shaft  82  rotates in a counterclockwise direction, tapered bearing  86  also rotates in a counterclockwise direction with power shaft  82  which causes crank plate  98  and lock ring  120  to also rotate in a counterclockwise direction. Tapered bearing  86  drives crank plate  98  in a counterclockwise direction due to the engagement of the spring-loaded sprags or dowels  116  mounted in crank plate  98  with the shoulders  90  at the ends of the cam surfaces  88  formed in tapered bearing  86 . At this time, gear  92  does not rotate due to the non-engagement of the sprags  96  positioned in the sprag pockets  108  in crank plate  98  with the sprag pockets  94  on gear  92 . As will be explained hereinafter, rotation of driven gear  92  in a counterclockwise direction by gear  140  will cause crank plate  98  to be rotated in a counterclockwise direction. As also described hereinafter, counterclockwise rotation of crank plate  98  by the driven gear  92  does not cause rotation of power shaft  82  since the spring-loaded sprags  116  will move out of the cam surfaces  88  at the opposite ends thereof from the shoulders  90 .  
         [0039]     At the beginning of the cycle described above, roller  143  will be in one of the notches  122  in lock ring  120 . When the roller  143  is in one of the notches  122 , the pivot plate  142  will be in its inward pivoted position so that the bracket  146  thereon will be adjacent proximity switch  148  which is the motor stop by deenergizing contactor to the motor. As crank plate  98  and lock ring  120  are initially rotated in a counterclockwise direction by power shaft  82 , the roller  143  moves up the tapered cam end  150  of the notch  122  and rolls upon the peripheral surface of lock ring  120  until it moves into the other notch  122 . When positioned in the notch  122 , the lock ring  120  cannot be rotated in a clockwise direction due to the engagement of the roller  143  with the lock end  152  of the notch  122  due to the shoulder-like design of the lock end  152 . The engagement of the roller  143  with the lock end  152  keeps pressure on the switch points to maintain the switch points in position.  
         [0040]     Rotation of crank plate  98  causes rod eye  128  to be reciprocatably moved towards cam follower assembly  42  thereby causing the rotational movement thereof which causes wave plate  36  to rotate therewith due to the positioning of the cams  46  and  48  in a pair of oppositely disposed grooves  38 . The spring force of the Bellville springs  50  yieldably maintains the cams  46  and  48  in the grooves  38  to act as a spring-loaded slip clutch which drives or rotates wave plate  36  and shaft  28 . If sufficient resistance is encountered during the opening or closing of the switch points due to an obstruction or the like which prevents complete opening or closing of the switch points, the cams  46  and  48  will move upwardly out of the grooves  38  against the resistance of the springs  50  so that throw rod  34  will not be further moved with respect to the obstruction.  
         [0041]     Assuming that an obstruction is not encountered in the cycle described above, the throw rod  34  and connecting rod  32  will be moved by the rotating crank eye  30  at the lower end of the shaft  28 . Rotation of the shaft  28  causes rotation of the target post base  76  and target  78  so that target  78  will indicate the position of the switch. The crank plate  98  continues its counterclockwise rotation described above until actuator  166  moves adjacent to switch  160  to actuate the same which causes motor  80  to be deactivated. In the event that an obstruction prevents the switch points from completely moving to their closed position, the crank plate  98  will continue to rotate, with the cam follower assembly rotating with respect to the non-moving wave plate  36 , until the roller  143  moves into a notch  122  thereby actuating proximity switch  148  which will deactivate motor  80 . Since shaft  28  and wave plate  36  did not completely rotate to the normal “closed” position, the target  78  will indicate the malfunction. The obstruction may then be removed and the machine re-set. The switch point opening cycle is performed in the manner set forth above except for the direction of movement of the throw rod  34 , connecting rod  32 , and rod eye  128 . In a trail through situation, the lock ring  120  prevents movement of the switch points. Movement of the switch points in a trail through situation is also prevented by the sprag clutch positioned between the crank plate  98  and the tapered bearing  86 .  
         [0042]     In the event of a power outage, the machine may be manually operated to open or close the switch points as follows. The hand throw lever  138  is unlocked and pivotally moved upwardly from its horizontally disposed position to its raised position. The upward movement of lever  138  causes hand throw shaft  136  to be rotated in a clockwise direction as viewed from the rear of the machine. Clockwise movement of shaft  136  causes drive gear  140  to also be rotated in a clockwise direction which in turn causes driven gear  92  to be rotated in a counterclockwise direction. Counterclockwise rotation of gear  92  causes clutch plate  98  to be rotated in a counterclockwise direction due to the spray slip clutch connection of gear  92  and clutch plate  98  as described above. Counterclockwise rotation of gear  92  does not cause rotation of tapered bearing  86  or power shaft  82  due to the spray slip clutch connection of crank plate  98  with respect to tapered bearing  86  as described hereinabove. Continued rotational movement of shaft  136  by lever  138  causes the machine to function as if crank plate  98  was being driven by motor  80 . One upward cycle of lever  138  causes the switch points to be moved from their open position to their closed position. The lever  138  is then returned to its horizontal position. If it is then desired to open the switch points, a second cycle of the lever  138  will accomplish the same.  
         [0043]     A bracket or post  170  extends upwardly from one of the plates  16  and has an opening  176  formed therein which is adapted to register with one of the openings  174  or  176  formed in bracket  178  which is secured to lever  138  ( FIG. 3 ). When opening  172  registers with opening  176 , the actuator  180  on shaft  136  will be adjacent proximity switch  182  positioned within housing  20  so that motor  80  is able to be actuated. Lever  138  may be locked in this position with a padlock or the like. When opening  174  registers with opening  172 , actuator  180  will not be adjacent proximity switch  182  which will prevent motor  80  from being actuated. Lever  138  may be locked in this “blue” position by a padlock or the like to prevent accidental actuation of motor  80 .  
         [0044]     Thus it can be seen that the invention accomplishes at least all of its stated objectives.