U.S. patent number 3,753,405 [Application Number 05/177,588] was granted by the patent office on 1973-08-21 for spike positioning system.
Invention is credited to John F. Bryan, Jr..
United States Patent |
3,753,405 |
Bryan, Jr. |
August 21, 1973 |
SPIKE POSITIONING SYSTEM
Abstract
A spike positioning system includes an electro-optical device
for locating spike receiving holes. The locating device is mounted
on a spike positioning mechanism that is in turn mounted for
movement by hydraulic cylinders. In use, the electro-optical device
controls a servo system which operates the hydraulic cylinders. The
cylinders in turn move the locating device and the spike
positioning mechanism into alignment with a spike receiving
hole.
Inventors: |
Bryan, Jr.; John F. (Dallas,
TX) |
Family
ID: |
22649184 |
Appl.
No.: |
05/177,588 |
Filed: |
September 3, 1971 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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839142 |
Jul 2, 1969 |
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Current U.S.
Class: |
104/17.1;
250/234 |
Current CPC
Class: |
E01B
29/26 (20130101) |
Current International
Class: |
E01B
29/00 (20060101); E01B 29/26 (20060101); E01b
029/26 () |
Field of
Search: |
;250/219,234
;104/12,7,8,17,17R ;25/219 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Forlenza; Gerald M.
Assistant Examiner: Bertsch; Richard A.
Parent Case Text
REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of the earlier filed
co-pending application of John F. Bryan, Jr., Ser. No. 839,142,
Filed July 2, 1969, now abandoned.
Claims
What is claimed is:
1. A spike positioning system comprising:
a spike positioning mechanism;
a frame for supporting the spike positioning mechanism at a spike
insertion location;
means for moving the spike positioning mechanism relative to the
frame;
a photoconductive image resolving device secured to the spike
positioning mechanism for movement therewith to scan the surface of
a tie plate;
logic means for identifying an image detected by the
photoconductive image resolving device as a spike receiving
hole;
servo means responsive to the detection of a spike receiving hole
by the photoconductive image resolving device for actuating the
moving means to center the spike positioning mechanism and the
photoconductive image resolving device on the spike receiving hole;
and
means for thereafter driving a spike from the spike positioning
mechanism and into the spike receiving hole.
2. The spike positioning system according to claim 1 wherein the
spike positioning mechanism moving means comprises a pair of
hydraulic cylinders for supporting the spike positioning mechanism
on the frame and for moving the spike positioning mechanism
relative to the frame under the control of the servo means.
3. The spike positioning system according to claim 1 wherein the
actuating means includes circuitry coupled to the output of the
photoconductive image resolving device for generating an output
proportional to the distance between a spike receiving hole and the
spike positioning mechanism.
4. The spike positioning system according to claim 1 wherein the
actuating means includes circuitry coupled to the output of the
photoconductive image resolving device for generating an output
indicative of the direction of displacement between a spike
receiving hole and the spike positioning mechanism.
5. The spike positioning system according to claim 1 wherein the
spike positioning mechanism comprises means for orienting the spike
in an insertion orientation, and wherein the spike driving means
comprises a hydraulic cylinder for actuation after the spike
positioning mechanism is aligned with the spike receiving hole to
drive the spike into the spike receiving hole.
6. A spike positioning system comprising:
means for positioning a spike in an insertion orientation;
means for moving the spike positioning means along a line extending
longitudinally of a rail and above a tie plate having a spike
receiving hole formed therein;
a photoconductive image resolving device mounted for movement with
the spike positioning means and oriented to scan along the line and
hence across the tie plate;
logic means actuated by the photoconductive image resolving device
for determining the scanning thereby of a spike receiving hole;
circuitry coupled to the output of the photoconductive image
resolving device for generating an output indicative of
misalignment between a spike receiving hole scanned by the
photoconductive image resolving device and the spike positioning
means; and
servo means responsive to the circuitry for actuating the moving
means to align the spike positioning means with the spike receiving
hole.
7. The spike positioning system according to claim 6 wherein the
spike positioning moving means comprises a frame for supporting the
spike positioning means at a spike insertion location and at least
one hydraulic cylinder for moving the spike positioning means
relative to the frame under the control of the servo means.
8. The spike positioning system according to claim 6 wherein the
circuitry coupled to the output of the photoconductive image
resolving device comprises a logic circuit for generating an output
whenever a spike receiving hole is scanned by the photoconductive
image resolving device and a hole location circuit for generating
an output indicative of the direction of displacement between a
spike receiving hole and the spike positioning means.
9. The spike positioning system according to claim 8 wherein the
circuitry coupled to the output of the photoconductive image
resolving device is further characterized by means for generating
an output proportional to the distance between a spike receiving
hole and the spike positioning means.
10. The spike positioning system according to claim 6 further
including means operable after the spike positioning means has been
aligned with the spike receiving hole for driving the spike into
the spike receiving hole.
11. A spike positioning system comprising:
means for positioning a spike in an insertion orientation;
a frame for supporting the spike positioning means at a spike
insertion location;
at least one hydraulic cylinder connected between the frame and the
spike positioning means for moving the spike positioning means
relative to the frame and along a line extending parallel to a rail
and above the surface of a tie plate supporting the rail;
a photoconductive image resolving device secured to the spike
positioning means for movement therewith along the line and
oriented to scan along the line and across the upper surface of the
tie plate;
logic means for identifying a portion of the scanned area as a
spike receiving hole in the tie plate;
servo means coupled to the output of the photoconductive image
resolving device for actuating the hydraulic cylinder to align the
spike positioning means with a spike receiving hole scanned by the
photoconductive image resolving device; and
a hydraulic cylinder for driving the spike out of the spike
positioning means and into the spike receiving hole.
12. The spike positioning system according to claim 11 further
characterized by a pair of hydraulic cylinders each for supporting
the spike positioning means on the frame and each responsive to the
servo means for moving the spike positioning means relative to the
frame and along the line.
13. The spike positioning system according to claim 11 wherein the
servo means includes circuitry for generating an output
proportional to the distance between a spike receiving hole scanned
by the vidicon tube and the spike positioning means.
14. The spike positioning system according to claim 13 wherein the
servo means further includes valving means for controlling the flow
of hydraulic fluid to the hydraulic cylinders and thereby
controlling the operation of the cylinders to move the spike
positioning means relative to the frame.
Description
BACKGROUND OF THE INVENTION
The rails of railroad and similar trackways are traditionally
positioned on metal tie plates that are in turn positioned on
wooden ties. The rails are secured to the ties by large metal
spikes which are driven into the ties through holes formed in the
tie plates. The use of the holes in the tie plates to guide the
insertion of the spikes into the ties assures proper positioning of
the spikes relative to the rails.
In the past, railroad spikes have been driven into ties either by
means of sledge hammers or by means of power driven spike inserting
devices. Heretofore, however, the insertion of railraod spikes has
been semiautomatic at best because no system had been provided for
automatically aligning a power driven spike inserting device. That
is, it has not previously been possible to automatically align a
spike to be driven with a spike receiving hole in a tie plate so
that the spike could be automatically driven into a tie by a power
driven spike inserting device.
This invention relates to a system for automatically aligning a
spike positioning mechanism with a spike receiving hole. The system
includes an electro-optical spike receiving hole locating device
and a servo system for guiding the positioning of a spike receiving
mechanism in accordance with the output of the electro-optical
device. Use of the system renders the insertion of railroad spikes
fully automatic.
SUMMARY OF THE INVENTION
In the preferred embodiment, this invention comprises a spike
positioning system including a spike positioning mechanism and an
electro-optical system for locating spike receiving holes.
Preferably, the system includes a servo system responsive to the
electro-optical system for moving the positioning mechanism into
alignment with a spike receiving hole.
DESCRIPTION OF THE DRAWINGS
A more complete understanding of the invention may be had by
referring to the following detailed description when taken in
conjunction with the drawings, wherein:
FIG. 1 is a side view of a spike positioning system employing the
invention in which certain parts have been broken away more clearly
to illustrate certain features of the invention;
FIG. 2 is a rear view of the device shown in FIG. 1;
FIG. 3 is a schematic illustration of a servo system employed in
conjunction with the device illustrated in FIGS. 1 and 2;
FIG. 4 is a schematic illustration of an alternative embodiment of
the system illustrated in FIG. 3;
FIG. 5 is a schematic illustration of another embodiment of the
system illustrated in FIG. 3; and
FIG. 6 is a graph illustrating the operation of the system shown in
FIG. 5.
DETAILED DESCRIPTION
Referring now to the Drawings and particularly to FIG. 1 thereof,
there is shown a rail 10 of the type typically employed in
constructing railroads and similar trackways. The rail 10 is
mounted on a metal tie plate 12 which is in turn mounted on a
wooden rail 14. The tie plate 12 has a plurality of spike receiving
holes 16 formed through it.
The rail 10 is secured to the tie 14 by large metal spikes that are
driven into the tie 14 through the holes 16 in the tie plate 12.
Consequently, during the construction of a trackway it is necessary
to align each spike with a spike receiving hole before the spike
can be driven into the tie. This invention relates to a system for
automatically aligning spikes with spike receiving holes.
Referring now to FIG. 2, a spike positioning and inserting
mechanism 18 is shown. The mechanism includes a pair of side plates
20 which are secured to a vehicle (not shown) similar to the small,
motor driven vehicles typically employed in railroad maintenance
and repair operations. The vehicle is operated to transport the
spike positioning and inserting mechanism 18 to a site at which
spikes are to be inserted. At the site, a mechanism on the vehicle
(not shown) aligns the spike positioning and inserting mechanism 18
with a spike receiving hole in a direction extending transversely
of the rails. Thereafter, the spike positioning and inserting
mechanism 18 operates automatically to precisely align a spike with
the spike receiving hole 16 in a direction extending longitudinally
of the rails, whereupon the spike is driven through the hole into a
tie 14.
The spike positioning and inserting mechanism 18 further includes a
pair of piston rods 22 and 24, both of which extend between the
side plates 20. The piston rods 22 and 24 are mounted in a pair of
retaining members 26 which are in turn secured to the side plates
20 by a plurality of bolts 28. A pair of hydraulic cylinders 32 and
34 are mounted on the piston rods 22 and 24, respectively. Each of
the cylinders 32 and 34 houses a piston (not shown) which is
secured to its respective piston rod. In use, the cylinders 32 and
34 are moved back and forth along the piston rods 22 and 24 by
supplying hydraulic fluid to and removing hydraulic fluid from
their opposite ends.
The hydraulic cylinders 32 and 34 support a spike inserting
hydraulic cylinder 36 and a spike positioning guideway 38. The
cylinder 36 is of standard construction and operates to move a
piston rod 40 upwardly and downwardly relative to the spike
positioning and inserting mechanism 18. As is most clearly shown in
FIG. 1, the piston rod 40 is normally enclosed in a guide sleeve 42
which extends downwardly from the hydraulic cylinder 36.
The spike positioning guideway 38 extends first parallel to and
then beneath the hydraulic cylinder 36. Spikes are inserted into
the upper portion of the guideway 38 either manually or by an
automatic mechanism and fall through the guideway under the action
of gravity. The lower portion of the guideway 38 is positioned
directly beneath the piston rod 40 of the cylinder 36 and includes
a pair of spike positioning springs 44 and a pair of spring loaded
spike-retaining rollers 46. As a spike falls through the guideway
38 it is brought into alignment with the piston rod 40 of the
cylinder 36 by the springs 44 which operate to restrict the main
portion of the spike to movement through the rear of the guideway
38. The rollers 46 engage the spike as it reaches the bottom of the
guideway 38 and prevent it from falling out of the guideway 38
until it is driven therefrom by the operation of the cylinder
36.
In use, the hydraulic cylinders 32 and 34 are operated to position
the guideway 38 in direct alignment with a spike receiving hole in
a tie plate. Thereafter, the cylinder 36 is operated to drive a
spike from the guideway 38 through the spike receiving hole 16 and
into a tie.
It might at first appear that the use of the cylinders 32 and 34 is
unnecessary since the guideway 38 could be aligned with a spike
receiving hole by simply manipulating the vehicle upon which the
spike positioning and inserting mechanism 18 is supported. However,
in actual practice, four spike positioning and inserting mechanisms
18 are mounted on the vehicle, one on each side of each rail of the
trackway. Often a particular tie may be positioned at a skewed
angle relative to the longitudinal axis of the trackway. Also, the
two tie plates that are supported on a particular tie are often
slightly misaligned relative to each other. Thus, if all four of
the positioning and inserting mechanisms on a vehicle were rigidly
mounted, it would be frequently impossible to bring them all into
alignment with four spike receiving holes at the same time. To this
end, the spike positioning and inserting mechanism 18 is equipped
with an automatic system for aligning the guideway 38 with a spike
receiving hole.
As is most clearly shown in FIG. 1, the aligning system of the
positioning and inserting mechanism 18 includes a spike receiving
hole locating device 48 which is secured to and moved with the
guideway 38. The hole locating device 48 may be a vidicon, an image
orthicon, or any similar photoconductive image resolving device.
Alternatively, the hole locating device 48 may be comprised of a
laser or other source of intense radiation and a photocell or other
radiation sensitive device. In either event, the hole locating
device 48 serves to operate a servo system which in turn controls
the operation of the cylinders 32 and 34 to bring the hole locating
device 48, and therefore the guideway 38 to which it is attached,
into alignment with a spike receiving hole.
The operation of the electro-optical spike receiving hole locating
device 48 to control the operation of the cylinders 32 and 34 in
positioning the guideway 38 can be best understood by referring to
FIGS. 3 and 4. Referring first to FIG. 3, a photoconductive image
resolving device type hole locating device 48 is coupled through an
amplifier 50 to a logic circuit 52. The logic circuit 52 produces
an output whenever a spike receiving hole is positioned anywhere
within the range of the photoconductive image resolving device. The
logic circuit 52 is connected to a hole locating circuit 54.
Whenever the logic circuit 52 produces an output, the hole location
circuit 54 produces an output proportional to the amount of
misalignment between the spike receiving hole and the center of the
photoconductive image resolving device. This output is either
positive or negative depending on the direction of misalignment.
The output of the hole location circuit 54 is directed through a
servo amplifier 56 to a servo motor 58. The servo motor 58 is in
turn mechanically coupled to a three position, four way valve
60.
The valve 60 operates to control the flow of hydraulic fluid
between four ports 62. Two of the ports 62 are coupled to a
hydraulic fluid supply line 64 and to a hydraulic fluid return line
66, respectively. The remaining ports 62 are coupled to a pair of
lines 68 and 70 which extend to the opposite ends of the cylinders
32 and 34, respectively.
In use, the servo motor 58 operates under control of the circuit 54
to control the position of the valve 60 relative to the ports 62.
The valve 60 in turn couples the lines 64 and 66 to the appropriate
ends of the cylinders 34 and 32 to cause movement of the cylinders
in a centering direction. This action continues until the circuit
54 determines that the spike receiving hole locating device 48 is
positioned in alignment with the spike receiving hole 16. When this
occurs, the circuit 54 actuates the valve 60 through the servo
amplifier 56 and the servo motor 58 to discontinue movement of the
hydraulic cylinders 32 and 34. Since the spike receiving hole
locating device 48 is coupled directly to the guideway 38, this
positions the guideway 38 in alignment with the spike receiving
hole.
Referring now to FIG. 4, a laser type electrooptical spike
receiving hole locating device 48 and a second servo system are
illustrated. The device 48 includes a laser 72 which produces a
high energy output. The reflection of the output of the laser 72 is
directed through a lens 74 to a photocell 76. The output of the
photocell 76 is directed through an amplifier 78 to a logic circuit
80.
The logic circuit 80 is coupled to a centering circuit 82 which
cooperates with the logic circuit 80 to control the operation of a
servo motor 84. In addition to receiving an input from the
amplifier 78, the logic circuit 80 receives an input from a flow
meter 86 positioned in the hydraulic fluid supply line 64.
In use, the logic circuit 80 is programmed to operate the valve 60
through the servo motor 84 in such a way that the cylinders 32 and
34 initially move in a predetermined direction. During this action,
the electro-optical spike receiving hole locating device 48 scans
for a hole having the size of a spike receiving hole. Whenever the
logic circuit 80 determines that the device 48 has traveled over
such a hole, it actuates the centering circuit 82. The circuit 82
in turn causes the servo motor 84 to reverse the travel of the
cylinders 32 and 34. During this action, the flow meter 86 produces
an output indicative of the distance traveled in the reverse
direction.
When the logic circuit 80 determines that the cylinders 32 and 34
have traveled exactly half the width of a spike receiving hole 16
in the reverse direction, it discontinues the operation of both the
centering circuit 82 and the servo motor 84. This action stops the
movement of the cylinders 32 and 34. At this time, the spike
receiving hole locating device 48 is positioned exactly in the
center of the spike receiving hole 16. Since the guideway 38 is
coupled directly to the device 48, the guideway 38 is therefore
positioned in alignment with the spike receiving hole 16.
Referring now to FIG. 5, a third servo system is shown. The third
servo system is actuated by a spike receiving hole locating device
48 comprising a vidicon, an image orthicon, or the like. The output
of the spike receiving hole locating device 48 is coupled to an
amplifier 90, and the output of the amplifier 90 is coupled to a
hole locating logic circuit 92 through a pulse duration circuit 94
and a pulse count circuit 96 and through a start of pulse detection
circuit 98. The hole location logic circuit 92 functions to produce
an output indicative of the direction of misalignment of the spike
receiving hole locating device 48 relative to a spike receiving
hole. This output is coupled to a servo motor 100 through a servo
amplifier 102. The servo motor 100 in turn controls the positioning
of the three position, four way valve 60 to actuate the hydraulic
cylinders 32 and 34. By this means, the spike receiving hole
locating device 48, and therefore the guideway 38, are moved into
alignment with the spike receiving hole.
The operation of the third servo system shown in FIG. 5 will be
better understood by referring to FIG. 6 which comprises a trace of
the output of the amplifier 90. Each vertical subdivision of FIG. 6
comprises one horizontal sweep of the spike receiving hole locating
device 48. Any spike receiving hole lying within the sweep of the
spike receiving hole locating device 48 appears as a square wave in
the trace. The time T.sub.s is the time from the initiation of the
sweep to the start of any particular pulse, and is therefore
indicative of the direction of misalignment of the spike receiving
hole locating device 48 from a spike receiving hole. The time
period T.sub.d is the duration of a particular pulse and is
therefore indicative of the width of a spike receiving hole that is
detected by the spike receiving hole locating device 48.
In the operation of the servo system shown in FIG. 5, the output of
the amplifier 90 is sampled by the pulse duration circuit 94. Each
pulse is monitored by the circuit 94 to determine whether the
period T.sub.d is equal in duration to a predetermined duration
corresponding to a spike receiving hole. If this test is passed,
the number of horizontal sweeps of the spike receiving hole
locating device 48 in which the pulse occurs is counted by the
pulse count circuit 96. The number of horizontal sweeps in whch the
pulse occurs is indicative of the length of a spike receiving hole.
Thus, if the count reached by the circuit 96 corresponds to a
predetermined count corresponding to a spike receiving hole, it is
known that a hole corresponding in length and width to a spike
receiving hole has been located by the spike receiving hole
locating device 48.
Whenever a spike receiving hole is identified by the pulse duration
circuit 94 and the pulse count circuit 96, the hole location logic
circuit 92 is actuated. The hole location logic circuit 92 is
responsive to the time period T.sub.s as determined by the start of
pulse detection circuit 98 to determine the direction of
misalignment of the spike receiving hole locating device 48 from
the spike receiving hole. That is, the output of the hole location
logic circuit 92 is either positive or negative or nil depending on
the positioning of the spike receiving hole locating device 48 to
the left, or to the right, or in alignment with the spike receiving
hole. The output of the hole location logic circuit 92 is amplified
by the servo amplifier 102 whereupon the servo motor 100 positions
either the left hand side, or the right hand side, or the center of
the three position, four way valve 60 in alignment with the ports
62. By this means the hydraulic cylinders 32 and 34 are actuated to
align the spike receiving hole locating device 48 with the spike
receiving hole.
Those skilled in the art will realize that the servo system shown
in FIG. 5 is capable of numerous modes of operation. For example,
the rate of hydraulic flow through the lines 64 and 66 may be
controlled at such a low rate that there is no possibility of
"overshoot" of the hydraulic cylinders 32 and 34 as the hole
locating device 48 comes into alignment with a spike receiving
hole. In another mode, the cylinders 32 and 34 are caused to
traverse very rapidly until the hole location logic circuit 92
notes that the spike receiving hole locating device 48 is within a
predetermined range of the spike receiving hole. At that time, the
hole location logic circuit 92 actuates a flow control device 104,
whereby the rate of flow of hydraulic fluid through the lines 64
and 66 is substantially reduced. That is, the rate of traverse of
the cylinders 32 and 34 is reduced to the point that there is no
possibility of overshoot when the spike receiving hole locating
device 48 comes into alignment with the spike receiving hole. In
accordance with still another mode of operation, the spike
receiving hole locating device 48 is initially positioned to a
particular side of a spike receiving hole, for example, the left
side. In such a case, the rate flow of hydraulic fluid to the
hydraulic cylinders 32 and 34 during leftward movement is very
high, so that some overshoot is virtually certain. As soon as the
hole location logic circuit 92 notes that the spike receiving hole
locating device is positioned to the right of a spike receiving
hole, the flow control device 104 is actuated to materially reduce
the rate of hydraulic fluid flow to the cylinders 32 and 34. By
this means the rate of return movement of the cylinders 32 and 34
is reduced to such a low level that no overshoot occurs. Other
modes of operation of a servo system of the type shown in FIG. 5
will readily suggest themselves to those skilled in the art.
It should be understood that the servo systems illustrated in FIGS.
3, 4, and 5 are exemplary only in that mamy other types of servo
systems can be employed in the practice of the invention. It should
be further understood that whereas the embodiment of the invention
illustrated in the Drawings operates to align a spike positioning
mechanism in a direction extending parallel to the track, the
invention can be employed to provide alignment in any direction and
in two directions at once.
In the use of the invention, the vehicle which supports the side
plates 20 is operated to roughly position the spike positioning and
inserting mechanism 18 at a spike insertion location. A spike is
then inserted into the guideway 38 whereupon it falls through the
guideway into position beneath the piston of the hydraulic cylinder
36. During this action the springs 44 guide the spike into proper
alignment with the piston 40 and the spring loaded rollers 46
restrain the spike from falling out of the guideway 38.
Before the cylinder 36 is actuated to insert the spike, the spike
receiving hole locating device 48 is operated to precisely align
the guideway 38 with a spike receiving hole. The device 48 operates
through a servo system to actuate the cylinders 32 and 34 to move
the guideway 38 into alignment with the spike receiving hole. As
soon as the guideway 38 is aligned, the cylinder 36 is actuated to
drive the spike through the rollers 36 and through the spike
receiving hole into a tie, whereupon the spike secures a rail to
the tie.
Although specific embodiments of the invention are illustrated in
the Drawings and described herein, it will be understood that the
invention is not limited to the embodiments disclosed but is
capable of rearrangement, modification, and substitution of parts
and elements without departing from the spirit of the
invention.
* * * * *