Railroad spring frog

An improved railroad trackwork frog is provided with a relatively fixed rigid wing rail, a relatively movable spring wing rail, a base plate, and at least one roller outrigger and ramp plate assembly which is attached to the spring wing rail and to the base plate, and which functions to cause limited upwards vertical movement of the spring wing rail relative to the base plate when the spring wing rail is moved laterally relative to the rigid wing rail by the engaged wheel flange of a passing rail car.

FIELD OF THE INVENTION 
This invention relates generally to railroad trackwork, and particularly 
concerns an improved frog of the spring-rail type which is principally 
used at turn-outs from main line track. 
BACKGROUND OF THE INVENTION 
A railroad frog is a device which is installed at the intersection of two 
running rails to permit the flanges of railroad car wheels moving along 
one of the rails to pass across the other rail. The frog supports the car 
wheels as they pass over the missing rail tread surface between the throat 
and the point of the frog, and also provides flangeways for the flanges of 
those car wheels which pass through the frog. 
As described in the specification of U.S. Pat. No. 4,624,428, issued in the 
name of Frank and assigned to the assignee of this application, a standard 
railroad spring frog includes a rigid wing rail, which is substantially 
aligned with a long point or heel rail connected to a turnout traffic 
rail, and a relatively movable wing rail which is substantially aligned 
with a short point or heel rail that is connected to a main line traffic 
rail. The movable wing rail is mounted with a yieldable free end, is often 
spring-biased against the frog long point rail by additional spring means, 
and provides a substantially continuous support for the wheels of a rail 
car passing along the main line track. The movable wing rail, sometimes 
called a spring wing rail, is moved laterally away from the long point 
rail to provide a wheel flangeway between the long point rail and the 
spring wing rail when a car wheel flange traversing the long point or 
rigid wing rail engages the spring wing rail free end and forces or causes 
it to move laterally to a full open position. 
Heretofore, such standard railroad trackwork frogs have utilized 
conventional horn/horn-holddown assemblies to limit spring wing rail 
vertical movement when the rail is moved sideways by action of passing car 
wheel flanges. Such conventional assemblies utilize: (1) sliding-type horn 
elements that are connected to and project laterally from the spring wing 
rail, and (2) horn holddown elements that are fastened to a frog base 
plate, that house riser block elements, and that slidably co-operate with 
and vertically restrain the sliding-type horn elements. However, it has 
long been observed that the conventional horn/horn-holddown assemblies are 
susceptible to excessive abrasive wear at the upper surfaces of the riser 
block elements and at the upper surfaces of the slide horn elements due to 
the inherent longitudinal twisting action of the spring wing rail which 
results as it is moved by flange-originated forces applied laterally to 
the upper portion of the rail. Also, spring wing rail lateral 
displacements and longitudinal twisting actions repeatedly effected as a 
result of wheel-flange forces result in excessive abrasion of the frog 
base plate element by the lower portion of the spring wing rail at its 
point of roll-over. 
I have invented a new and useful railroad trackwork frog construction, 
including a new and useful spring wing rail attached roller outrigger 
subassembly with a co-operating ramp-like roller support, that overcomes 
the noted deficiencies associated with the prior art railroad trackwork 
frog conventional construction using slide-type horn/horn-holddown 
assemblies to effect limited spring wing rail vertical movement. Other 
objects and advantages of the present discovery will become apparent 
during a careful consideration of the invention summary, description of 
the drawings, and detailed description which follow. 
SUMMARY OF THE INVENTION 
The improved railroad trackwork frog of this invention is essentially 
comprised of a base plate element, a fixed wing rail element mounted to 
the base plate element, a movable wing rail element mounted to the base 
plate element and having a yieldable, free end portion, and one or more 
combined roller outrigger and riser plate elements which are each rigidly 
connected to the base plate element and to the movable wing rail element 
and which each function to permit limited vertical displacement of the 
movable wing rail with minimum rail twisting as the rail is moved 
laterally by its engagement with the flanges of rail car wheels passing 
through the frog. 
In addition, the improved railroad trackwork frog of this invention may 
advantageously include a spring box element which is connected to the base 
plate element and which functions to positively return the movable wing 
rail to its initial full closed position after co-operating car wheel have 
passed through the frog. Also, the frog construction may advantageously 
further include one or more novel roller holddown elements which are 
usually connected to the base plate element at positions near the roller 
outrigger and riser plate combination elements and which function to limit 
vertical displacement of portions of the spring wing rail.

DETAILED DESCRIPTION 
Referring to FIG. 1, a right-hand spring frog assembly 10 is shown inserted 
in one rail 12 of a pair of turnout rails 12, 14 and one rail 16 of a pair 
of mainline rails 16, 18. Spring frog 10 is assembled and mounted on a 
base plate element 20 which provides a level foundation for the frog and 
which maintains the elements which comprise the frog in their proper 
relationship during assembly, shipping, and subsequent installation in a 
railroad trackwork. Frog assembly 10 is functionally positioned to permit 
flanged rail car wheels riding along rail 12 to cross rail 16 and flanged 
rail car wheels riding along rail 16 to cross rail 12. A conventional 
switch stand for directing rail cars from rail pair 12, 14 to rail pair 
16, 18 and vice versa is necessary for the trackwork but does not comprise 
a portion of frog assembly 10. 
A long point rail element 22 is mounted on base plate 20 at the heel end of 
frog assembly 10 and has a rail end 24 which upon frog installation is 
joined, as by welding, to turnout line rail 12 to provide a connection for 
that rail to frog assembly 10. A short point rail 26 is also mounted on 
base plate 20 and has a rail end 28 which upon frog installation is 
joined, as by welding, to mainline rail 16 to connect that rail to frog 
assembly 10. Long point rail element 22 and short point rail element 26 
are mounted on base plate element 20 at an included angle relative to each 
other which is known as the angle of frog. A heel block element 49 may be 
bolted into position with and between point rail elements 22 and 26 to 
maintain the desired angle and spacing between such point rail elements, 
and also a heel riser element (not illustrated) may be provided to protect 
the point rails from damage due to car wheels having false flanges. See 
U.S. Pat. No. 4,362,282 for a description of the false flange protection 
problem. Long point rail element 22 terminates with a tapered vertical 
surface 30 on one side which is substantially parallel with mainline rail 
16, and short point rail element 26 terminates with a tapered vertical 
surface 32 on one side which is substantially parallel with turnout rail 
12. Surface 32 is complementary to and engages one side of long point rail 
22. The pointed end of long rail element 22 terminates with a width of 
approximately one-half inch and is known as the half inch point of the 
frog assembly. 
The generally-curved, fixed wing rail element 40 of frog assembly 10 has an 
end 42 connected to a curved closure rail section 43, has a long body 
section 44, and has a joined, angled body section 46 that is oriented 
generally parallel to short point rail element 26. Upon installation, 
closure rail section 43 is joined at its end 42 to a section of turnout 
rail 12. The end 48 of wing rail element 40 is preferably flared so that 
the flange of a car wheel moving along short point rail element 26 toward 
element 40 will not strike the wing rail free end. An elongated inter-rail 
spacer or filler 47 is positioned intermediate and joined to the web 
portions of short-point rail 26 and fixed wing rail end portion 46 and 
also intermediate and joined to the web portions of long-point rail 24 and 
rail end portion 46 and functions to establish a continuously open 
flangeway between those rails principally to accommodate the car wheel 
flanges of rail cars passing through frog assembly 10 on mainline tracks 
16 and 18. The rigid wing rail element 40 is rigidly secured to base plate 
element 20 by conventional means such as plate clips and is a relatively 
immovable member of frog assembly 10. 
The yieldably-mounted spring wing rail element 50, which is the primary 
movable member of frog assembly 10, has a straight, long body section 52 
which terminates at an end 54 that upon installation is joined to a 
section of mainline rail 16. Element 50 also has an angled body section 58 
which is at the opposite end of long body section 52. Angled body section 
58 is parallel to and engages the side of long point rail 22 opposite that 
engaged by short point rail 26. The free end 60 of angled body section 58 
is flared so that no portion of its very end 62 can be accidentally struck 
by the flange of a car wheel moving from the long point rail element 22 
toward spring wing rail element 50. An additional conventional spacer 
block 59 may, as in the case of spacer block 49, be advantageously 
positioned in assembly 10 but at the toe end between and connected to 
spring wing rail element 50 and to rigid wing rail element 40 to maintain 
their desired spacing and included angle of intersection. It should be 
noted that spring wing rail 50 at its angled body section 58 and at its 
free end 60 is not secured to base plate element 20 either by conventional 
plate clips or the like. 
Thus, when the flange of a car wheel engages spring wing rail 50 at its 
free end 60 and causes it to move laterally so that a flangeway is 
provided between long point rail 22 and spring wing rail 50, rail 50 is 
stressed and flexed from the point of wheel engagement to where it is 
attached to spacer block 59. Spring wing rail element 50 is acting 
essentially as a cantilevered beam with a force applied at or close to its 
free end 60. 
The railroad trackwork installation shown in FIG. 1 also typically includes 
a pair of conventional guard rail elements 64, 66 having flared ends which 
are positioned at turnout rail 14 and at mainline rail 18, each in 
spaced-apart relation to the adjacent rail by a distance that is slightly 
greater than the standard car wheel flange thickness, respectively, that 
function to "protect" rail 50 from lateral forces caused by possibly 
skewed car wheels and to assist in maintaining the gage of the track rail. 
In addition, and as shown in FIG. 1, the improved railroad spring frog 
assembly 10 of this invention includes at least one hereinafter-described 
novel roller outrigger and ramp plate subassembly element 70 which, 
optionally but also advantageously, may be utilized in combination with 
one or more novel roller holddown subassemblies 72, each such subassembly 
70 and 72 being rigidly connected in-part to spring wing rail 50 and 
in-part to base plate element 20. Subassemblies 70 and 72 function, during 
periods when a rail car wheel flange engages the free end 60 of spring 
wing rail 50 to cause lateral displacement of rail 50, to limit upwards 
vertical movement of the rail while permitting rail lateral movement, and 
to additionally do so in a manner which eliminates abrasion of the base 
plate, horn, and holddown elements of the assemblies. 
Heretofore, state-of-the art spring-rail type railroad trackwork frog 
assemblies have utilized one or more conventional co-operating rail horn 
and horn holddown sub-assemblies of the type schematically referenced as 
80 in FIG. 2 to vertically restrain a spring wing rail 82 during lateral 
rail movement caused by the rail's engagement with and displacement by a 
passing car wheel flange. Sub-assembly 80 is basically comprised of a horn 
element 84 that is rigidly and fixedly secured to spring wing rail 82 and 
a co-operating strap-like horn holddown 86 that slidably receives horn 
element 82. 
As previously indicated, repeated lateral movement of a spring wing rail 
between its full closed and full open positions in response to the passing 
of rail car wheels through the conventional frog assembly installation 
causes excessive component wear due to metal abrading at least three 
different location. More specifically, and referring to FIG. 2, excessive 
wear has been noted at the upper surface region 87 of the riser block 
component of holddown 86, at the upper surface region 88 of the assembly 
horn element 84, and at the surface region 89 of the base plate upon which 
assembly 80 is mounted. The abrasion wear is principally caused by rail 
car wheel-originated flange forces being applied laterally to the side of 
the tread portion of the spring wing rail movable end causing the rail to 
become twisted or rotated about the laterally sliding rail base toe-like 
point of roll-over as it is moved when placing the frog assembly in an 
open condition. Such surface abrasion can be avoided totally by 
utilization of the combined roller outrigger and ramp plate frog element 
70 detailed in FIGS. 3 and 4. 
As shown in FIGS. 3 and 4, roller outrigger and ramp plate assembly 70 is 
comprised of a forged outrigger arm 90, which is preferably made of a 
ductile iron, that has an integral base element 92 mounted to the web 
portion of spring wing rail 50 and rigidly secured in place by threaded 
fastener means 94. The integral housing portion 95 formed at the outboard 
end of outrigger arm element 90 partially contains, and rotatably 
supports, a roller wheel designated 96. Such roller wheel is preferably 
made of a forged and hardened metal and is supported by and co-operates 
with a ramp plate 98. 
As best illustrated in FIG. 4, the upper surface of ramp plate 98, which 
ramp plate is usually welded in position to frog base plate element 20, 
has a sloped riser section 99 that is positioned intermediate two adjacent 
flat (non-rise) upper surface sections. In one actual embodiment of this 
invention ramp plate element 98 was provided with an intermediate sloped 
surface that measured approximately 5 inches in width by 11/2 inches in 
length and had a rise of approximately 1/16 inch or 3/32 inch depending on 
assembly 70 location along the spring wing rail 50 from the free end 62. 
As previously indicated, when a rail car wheel flange moves the spring 
wing rail 50 toward a frog fully open condition, both outrigger arm 90 and 
the attached spring wing rail 50 are raised vertically thus taking the 
base undersurface of rail 50 out of contact with the upper surface of base 
plate element 20. The new "roll-over" point for rail 58 lies on the upper 
surface of ramp plate 98 vertically below the axis of roller wheel 96. 
Additionally, sloped riser section 99 of ramp plate 98 acts to assist in 
closing spring wing rail 5e against long point rail 22 after a car wheel 
flange has passed therebetween. This sloped riser section 99 also acts to 
resist excessive outward or lateral movement of spring rail 50 when a car 
wheel flange engages it. 
In addition to the utilization of at least one roller outrigger assembly 70 
in the improved railroad spring frog of this invention, I find it 
advantageous to include at least one roller holddown assembly 72 in order 
to provide a limit to any upwards vertical movement of spring wing rail 50 
beyond that produced by the interaction of roller outrigger wheel element 
96 and the sloped surface portion 99 of ramp plate 98 during lateral 
movement of spring wing rail 50 to a full open condition. It should be 
noted that assembly 70 does not provide a positive limit to that possible 
excess vertical movement. 
As shown in FIGS. 5 and 6, assembly 72 is basically comprised of a roller 
horn element 100 that is rigidly secured to the web portion of spring wing 
rail 50 by threaded bolt fasteners 101 and of a roller holddown element 
102 that co-operates with horn element 100. Horn element and roller 
holddown element 102 are each preferably forged of a ductile iron 
material. Contained in strap-like subassembly 102, which subassembly is 
fastened to riser blocks that are welded to base plate 20, is a hardened 
and rotatable metallic roller wheel 104. The upper surface of roller horn 
100 is preferably provided with a crown contour, and an initial gap or 
space 106 is provided between the upper surface of roller horn 100 and the 
lowest point of roller wheel 104 when spring wing rail 50 is in its full 
closed condition. The gap or space is preferably slightly greater in 
dimension that the amount of vertical rise incorporated into the ramp 
plate element 98 so that when spring wing rail is moved to its full open 
condition, vertically restrained roller wheel 104 functions to limit any 
significant further upward movement of roller horn element 00 and its 
attached spring wing rail. 
From the foregoing it becomes apparent that substantial component wear 
associated with the conventional spring frog construction that utilizes 
sliding rail horn and horn holddown elements may be nearly totally avoided 
by utilizing the above-described roller outrigger and roller horn holddown 
subassemblies instead. 
Other component shapes, sizes, and materials may be substituted for the 
component shapes, sizes, and materials described above to obtain the 
advantages of this invention and without departing from the claimed scope 
of the invention.