U.S. patent application number 11/551761 was filed with the patent office on 2008-04-24 for railroad crossing gate having a universal crossing gate arm with a rack and pinion counterweight adjustment system.
This patent application is currently assigned to Union Switch & Signal, Inc.. Invention is credited to Cory Allen Cook, Frederick Earl Woodlief.
Application Number | 20080093509 11/551761 |
Document ID | / |
Family ID | 39317018 |
Filed Date | 2008-04-24 |
United States Patent
Application |
20080093509 |
Kind Code |
A1 |
Woodlief; Frederick Earl ;
et al. |
April 24, 2008 |
RAILROAD CROSSING GATE HAVING A UNIVERSAL CROSSING GATE ARM WITH A
RACK AND PINION COUNTERWEIGHT ADJUSTMENT SYSTEM
Abstract
A railroad crossing gate comprising a crossing gate arm having a
counterweight support structure and one or more counterweights
supported by the counterweight support structure. The counterweight
support structure includes a gear rack provided along a first
portion of the crossing gate arm and a pinion gear operatively
coupled to and selectively movable along the gear rack.
Inventors: |
Woodlief; Frederick Earl;
(Lexington, SC) ; Cook; Cory Allen; (Lexington,
SC) |
Correspondence
Address: |
Robert A. Diaz;Eckert Seamans Cherin & Mellott, LLC
44th Floor, 600 Grant Street
Pittsburgh
PA
15219
US
|
Assignee: |
Union Switch & Signal,
Inc.
Pittsburgh
PA
|
Family ID: |
39317018 |
Appl. No.: |
11/551761 |
Filed: |
October 23, 2006 |
Current U.S.
Class: |
246/473.1 |
Current CPC
Class: |
B61L 29/04 20130101;
B61L 29/00 20130101 |
Class at
Publication: |
246/473.1 |
International
Class: |
B61L 29/00 20060101
B61L029/00 |
Claims
1. A railroad crossing gate, comprising: a crossing gate arm having
a counterweight support structure, said counterweight support
structure including a gear rack provided along a first portion of
said crossing gate arm and a pinion gear operatively coupled to and
selectively movable along said gear rack; and one or more
counterweights supported by said counterweight support structure;
wherein said one or more counterweights are operatively coupled to
said pinion gear and wherein said one or more counterweights may be
selectively moved along said first portion of said crossing gate
arm by selectively moving said pinion gear along said gear
rack.
2. The railroad crossing gate arm according to claim 1, wherein
said first portion of said crossing gate arm includes an elongated
aperture therethrough, wherein said counterweight support structure
includes at least one elongated shaft received through said
aperture and operatively coupled to said pinion gear, and wherein
said one or more counterweights are supported by said at least one
elongated shaft.
3. The railroad crossing gate arm according to claim 2, wherein
said gear rack is provided adjacent to a first side of said
elongated aperture, and wherein said counterweight support
structure includes a beam provided along said first portion of said
crossing gate arm adjacent to a second side of said elongated
aperture that is opposite said first side of said elongated
aperture.
4. The railroad crossing gate arm according to claim 2, wherein
said counterweight support structure includes a plate, wherein said
pinion gear is operatively coupled to said plate and wherein said
plate operatively couples said pinion gear to said elongated
shaft.
5. The railroad crossing gate arm according to claim 4, wherein
said plate is positioned between said one or more counterweights
and said at least one elongated shaft.
6. The railroad crossing gate arm according to claim 4, wherein
said at least one elongated shaft extends through said plate and is
secured to said crossing gate arm by at least one mechanical
fastener.
7. A universal crossing gate arm for use in a railroad crossing
gate, said railroad crossing gate having a motor for selectively
rotating said universal crossing gate arm about an axis of
rotation, said motor having a driveshaft and a hub operatively
coupled to said driveshaft, said universal crossing gate arm
comprising: a first face; a second face opposite said first face; a
first hub receiving element provided on said first face, said first
hub receiving element being structured to receive and engage with
said hub of said motor; and a second hub receiving element provided
on said second face, said second hub receiving element being
structured to receive and engage with said hub of said motor.
8. The universal crossing gate arm according to claim 7, wherein
said first hub receiving element comprises a first recessed web
provided in said first face and said second hub receiving element
comprises a second recessed web provided in said second face.
9. The universal crossing gate arm according to claim 7, further
comprising a first gear rack provided along said first face and a
second gear rack provided along said second face, said first gear
rack and said second gear rack being structured to mechanically
engage a pinion gear of a counterweight support structure of said
railroad crossing gate, wherein one or more counterweights may be
operatively coupled to said pinion gear and may be selectively
moved along said universal crossing gate arm by moving said pinion
gear along one of said first gear rack and said second gear
rack.
10. A counterweight support structure for movably supporting one or
more counterweights in a railroad crossing gate having a crossing
gate arm, comprising: a gear rack provided along a first portion of
said crossing gate arm, a pinion gear operatively coupled to and
selectively movable along said gear rack; and means operatively
coupled to said pinion gear for supporting said one or more
counterweights; wherein said one or more counterweights may be
selectively moved along said first portion of said crossing gate
arm by selectively moving said pinion gear along said gear
rack.
11. The counterweight support structure according to claim 10,
wherein a first portion of said crossing gate arm includes an
elongated aperture therethrough and wherein said means for
supporting said one or more counterweights includes at least one
elongated shaft received through said elongated aperture.
12. The counterweight support structure according to claim 11,
wherein said gear rack is provided adjacent to a first side of said
elongated aperture and wherein said counterweight support structure
further comprises has a beam provided along said portion of said
crossing gate arm adjacent to a second side of said elongated
aperture that is opposite said first side of said elongated
aperture.
13. The counterweight support structure according to claim 11,
wherein said counterweight support structure includes a plate,
wherein said pinion gear is operatively coupled to said plate and
wherein said plate operatively couples said pinion gear to said
elongated shaft.
14. The counterweight support structure according to claim 13,
wherein said plate is positioned between said one or more
counterweights and said at least one elongated shaft.
15. The counterweight support structure according to claim 13,
wherein said at least one elongated shaft extends through said
plate and is secured to said crossing gate arm by at least one
mechanical fastener.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to railroad crossing gates.
More specifically, this invention relates to a railroad crossing
gate having a rack and pinion counterweight adjustment system and
universal crossing gate arms.
[0003] 2. Description of the Related Art
[0004] Automatic railroad gates, which include one or more railroad
crossing gate arms, are used at many crossings where a road
intersects a railroad track. The typical railroad crossing gate arm
is finely counterbalanced with a weight or weights so that only a
relatively small, low horsepower, and low current consuming rotary
electric motor having associated gears is necessary to move the
railroad crossing gate arm up and down as needed. The use of low
horsepower motors, which consume low power, is particularly
important in situations where railroad gates are located in
isolated or inaccessible places where they may have to be run from
battery power or, in some modern installations, solar charged
battery power.
[0005] Due to a number of considerations, described below, frequent
adjustments and realignments of the counterbalance weights are
typically required in order to insure that the railroad crossing
gate arm is able to be readily moved by the associated low
horsepower motor. Such considerations include changing weather
conditions, particularly changing temperatures with changing
seasons, snow accumulation on the crossing gate arm, wear and tear
on the operating motor, and changes in the power system, such as
current source variations. Other factors which may disturb the
balance or require readjustment include broken or damaged railroad
crossing gate arms due to being struck by a vehicle or damage to
the gate due to vandalism.
[0006] The adjustment of existing counterbalance weight mechanisms
is not, however, a simple task. A railroad crossing gate arm is a
relatively heavy structure and, as a result, the counterbalance
weights are also quite heavy. That is particularly true if the
counterbalance arm is to be made relatively short in order to
obtain maximum leverage. Adjusting counterbalance weights, which
are usually in the form of metal plates, normally entails releasing
a large bolt-type fitting or other fastening means which maintains
the counterbalance weights in a particular longitudinal position
with respect to the gate structure, and then moving such
counterbalance weights to a different longitudinal or other
position on the gate structure. Once the weights have been
repositioned, the large bolts or other fastening means are
retightened manually. Since the counterweights are quite heavy, the
readjustment process requires a large weight to be supported by the
maintenance personnel performing the readjustment during the entire
process. As a result, it is not unusual for a manual adjustment of
the weights on a gate to take several hours, incurring a very
significant cost in manpower. Such personnel are particularly
subject to strained muscles, hernias, and other like injuries while
adjusting the counterweights. In other words, the readjustment
process presents a great risk of injury to personnel. Additionally,
as will be appreciated, the manual adjustment process is often
quite time consuming.
[0007] Furthermore, railroad crossing gate arms are designed to be
mounted on a specific side of the housing that contains the
railroad crossing gate mechanism. That is, railroad crossing gate
arms are designed to be mounted on either the left side of the
housing or on the right side of the housing only. Current railroad
crossing gate arms are single-sided because the crossing gate arms
have a hub receiving mechanism (i.e., a web or a flange) for
receiving a motor hub that is disposed on only one side of the
crossing gate arm and, therefore, permit mounting on only one side
of the housing that houses the motor. If the railroad crossing gate
arm is designed to be mounted on the left side of the housing, then
the railroad crossing gate arm cannot be mounted on the right side
of the housing and vice versa. This is problematic because a large
stockpile of left and right sided railroad crossing gate arms has
to be stored in a storage facility in the event that a railroad
crossing gate arm has to be replaced.
SUMMARY OF THE INVENTION
[0008] These needs and others are met by embodiments of the
invention, which provide a railroad crossing gate having a
universal crossing gate arm with a rack and pinion counterweight
adjustment system.
[0009] In accordance with one embodiment of the invention, a
railroad crossing gate is provided that includes a crossing gate
arm having a counterweight support structure and one or more
counterweights supported by the counterweight support structure.
The counterweight support structure includes a gear rack provided
along a first portion of the crossing gate arm and a pinion gear
operatively coupled to and selectively movable along the gear rack.
The one or more counterweights are operatively coupled to the
pinion gear and may be selectively moved along the first portion of
the crossing gate arm by selectively moving the pinion gear along
the gear rack.
[0010] In accordance with another embodiment of the invention, a
universal crossing gate arm for use in a railroad crossing gate.
The railroad crossing gate has a motor for selectively rotating the
universal crossing gate arm about an axis of rotation. The rotor
has a driveshaft and a hub which is operatively coupled to the
driveshaft. The universal crossing gate arm includes a first face,
a second face, a first hub receiving element disposed on the first
face, and a second hub receiving element disposed on the second
face. The first and second hub receiving elements are structured to
receive and engage with the hub of the motor.
[0011] In accordance with yet another embodiment of the invention,
a counterweight support structure for movably supporting one or
more counterweights in a railroad crossing having a crossing gate
arm. The counterweight support structure includes a gear rack
provided along a first portion of the crossing gate arm, a pinion
gear operatively coupled to and selectively movable along the gear
rack, and means operatively coupled to the pinion gear for
supporting the one or more counterweights. The counterweights may
be selectively moved along the first portion of the crossing gate
arm by selectively moving the pinion gear along the gear rack.
[0012] One aspect to this invention is to provide a counterweight
adjustment system that reduces the amount of time required to
adjust the counterweights on a railroad crossing gate arm.
[0013] Another aspect to this invention is to provide a railroad
crossing gate arm that can be mounted on opposite sides of a
housing that contains a railroad crossing gate mechanism.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] A full understanding of the disclosed and claimed concept
can be gained from the following Description when read in
conjunction with the accompanying drawings in which:
[0015] FIG. 1 is an isometric view of a portion of an automatic
railroad crossing gate in accordance with one embodiment of the
invention;
[0016] FIG. 2 is an exploded view of a universal crossing gate arm
and a counterweight adjustment system forming a part of the
automatic railroad crossing gate arm of FIG. 1;
[0017] FIGS. 3A and 3B are left and right side elevation views of
the universal crossing gate arm shown in FIG. 2, and
[0018] FIG. 4 is an isometric view of a portion of the universal
crossing gate arm and counterweight adjustment system shown in
FIGS. 1 and 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] As used herein, the term "universal railroad crossing gate
arm" and variations thereof shall broadly refer to a crossing gate
arm that can be positioned on either side of a housing that
contains a railroad crossing gate mechanism used to move the
railroad arm.
[0020] As used herein, the term "mechanical fastener" or variations
thereof shall broadly refer to any suitable fastening, connecting
or tightening mechanism including, but not limited to, screws,
bolts, nuts, and the combination of bolts and nuts or bolts/nuts
and washers.
[0021] Directional phrases used herein, such as, for example,
upper, lower, left, right, vertical, horizontal, top, bottom,
above, beneath, clockwise, counterclockwise and derivatives
thereof, relate to the orientation of the elements shown in the
drawings and are not limiting upon the claims unless expressly
recited therein.
[0022] FIG. 1 shows a portion of a railroad crossing gate 2
according to one embodiment of the present invention. The railroad
crossing gate 2 includes a housing 4 that contains therein a rotary
electric motor having associated gears (not shown) that selectively
raises and lowers the universal crossing gate arms 6 (described
below) and the elongated crossing gate arms that typically extend
therefrom. As seen in FIG. 1, a circular hub 12 extends from the
housing 4 on either side thereof. Each hub 12 is rotatably
connected to the drive shaft of the motor contained within the
housing 4 and is, therefore, rotatably driven thereby. In addition,
each hub 12 has a plurality of bolts (not shown) which extend in a
circular fashion around the outer periphery thereof. A central
shaft 8 is disposed within the circular arrangement of bolts.
[0023] As seen in FIG. 1, the railroad crossing gate 2 has two
universal crossing gate arms 6 that are positioned on opposite
sides of the housing 4. It is noted, however, that in alternate
embodiments the railroad crossing gate 2 can have a single
universal crossing gate arm 6 as described herein. Each of the
universal crossing gate arms 6 includes a hub receiving element 14,
such as a recessed web or a flange, on each side thereof (i.e., on
both the left and right sides thereof as shown in FIGS. 3A and 3B).
As described in greater detail hereinbelow, each hub receiving
element 14 is structured to receive and engage with a selected one
of the hubs 12 extending from the housing 4. In this manner, each
universal gate arm 6 may be selectively and rotatably attached to a
chosen side of the housing 4 such that they may be driven by the
motor (not shown) contained therein. Accordingly, the universal
crossing gate arm 6, unlike other current crossing gate arm
designs, is capable of being mounted on either side of the housing
4.
[0024] Referring to FIGS. 1 and 2, each of the universal crossing
gate arms 6 also includes a counterweight adjustment system 16. The
counterweight adjustment system 16 is shown in exploded fashion in
FIG. 2. The counterweight adjustment system 16 comprises a gear
rack 18 that is disposed on each side of the universal crossing
gate arm 6. The gear rack 18 is positioned adjacent to a bottom
side of an elongated aperture 20 that extends along the length of
the universal crossing gate arm 6. The gear rack 18 has a plurality
of teeth 22 extending from a top surface of the gear rack 18.
Adjacent to the top side of the elongated aperture 20 is a beam 24,
preferably having a length substantially equal to the gear rack 18,
which extends along the universal crossing gate arm 6 in a
direction substantially parallel to the gear rack 18. A plurality
of elongated shafts 26, each having a first end and a second end,
extend through the elongated aperture 20 in a direction
substantially perpendicular to the length of the gear rack 18 and
the beam 24. In the embodiment depicted in FIGS. 1 and 2, the
elongated shafts 26 are threaded.
[0025] Referring to FIGS. 2 and 4, in order to prevent the
elongated shafts 26 from mechanically engaging with the teeth 22 of
the gear rack 18, each of the elongated shafts 26 extend through a
corresponding sleeve 28 that is positioned within the elongated
aperture 20. The first end of each elongated shaft 26 is positioned
on the side of the universal crossing gate arm 6 that is adjacent
to the housing 4 (i.e., the inner side of the universal crossing
gate arm 6). Each elongated shaft 26 is selectively movably secured
to the universal crossing gate arm 6 by a mechanical fastener, such
as a bolt 30 and washer 32, which is fastened to the first end of
the elongated shaft 26. As can be seen from FIG. 1 (and in the
detailed portion thereof shown in FIG. 4), the washers 32 do not
come into contact with the teeth 22 of the gear rack 18, but rather
the washers 32 contact the outer surface 34 of the gear rack 18. On
the opposite side of the universal crossing gate arm 6 (i.e., the
outer side which faces away from the housing) is a support plate 36
having a plurality of apertures 38 through which the elongated
shafts 26 extend. The counterweights (not shown) are structured to
be mounted on the elongated shafts 26 and the support plate 36. In
the embodiment depicted in FIGS. 1 and 2, the apertures 38 in the
support plate 36 are threaded. Accordingly, each elongated shaft 26
mechanically engages the corresponding aperture 38 through which it
extends, thereby securing the elongated shaft 26 to the support
plate 36.
[0026] A pinion gear 40 is positioned between the elongated shafts
26 on the inner side of the universal crossing gate arm 6 (i.e.,
the side adjacent to the housing 4). The pinion gear 40 is
structured to mechanically engage with the gear rack 18
(specifically, the teeth 22 of the gear rack 18) that is provided
on the inner side of the universal crossing gate arm 6. The pinion
gear 40 is secured to the support plate 36 by a mechanical fastener
42 that extends through the pinion gear 40 and into an aperture 44
disposed on the support plate 36. Rotation of the pinion gear 40 as
shown by the arrows 46 will cause the support plate 36 and the
elongated shafts 26 (hereafter, the pinion gear 40, the elongated
shafts 26, the support plate 36, and any associated structures
shall collectively be referred to as the counterweight support
structure) to move along the gear rack 18 in either direction
therealong. As will be discussed in greater detail below, the
location of the counterweights that are mounted to the universal
crossing gate arms 6 can be adjusted by rotation of the pinion gear
40 in this manner.
[0027] Referring to FIGS. 3A and 3B, the hub receiving element 14
that is disposed on each side of the universal crossing gate arm 6
allows the universal crossing gate arm 6 to be mounted on either
side of the housing 4. As can be seen from these figures, the hub
receiving element 14 is comprised of a central aperture 10 that is
surrounded by a plurality of apertures 48. In the embodiment
depicted in FIGS. 3A and 3B, the central aperture 10 is surrounded
by twelve apertures 48. The central aperture 10 is adapted to
receive the central shaft 8 of the hub 12 while the apertures 48
are adapted to receive the bolts (not shown) positioned around the
outer periphery of the hub 12. The hub 12 is then fastened to the
universal crossing gate arm 6 by a plurality of mechanical
fasteners (not shown), such as nuts, that engage the bolts that
surround the central aperture 10. Once the hub 12 is fastened to
the universal crossing gate arm 6, the universal crossing gate arm
6 can be raised and/or lowered by the motor provided within the
housing 4. Moreover, to facilitate the universal nature of the
universal crossing gate arm 6 (i.e., to allow it to be mounted on
either side of the housing 4 along with a functioning
counterweights support structure), the gear rack 18 as well as the
beam 24 is also disposed on each side of the universal crossing
gate arm 6 adjacent to the elongated aperture 20 in the manner
described herein.
[0028] When the position of the counterweight support structure,
including the counterweights that are mounted on the counterweight
support structure, needs to be adjusted, the mechanical fasteners
that secure the elongated shafts 26 to the universal crossing gate
arm 6 are loosened to permit the counterweight support structure to
be relocated. Once the mechanical fasteners on the elongated shafts
26 are loosened, the pinion gear 40 is rotated. Rotation of the
pinion gear 40 moves the counterweight support structure in the
direction that the pinion gear 40 is being rotated. Once the
counterweight support structure is in the desired location, the
mechanical fasteners on the elongated shafts 26 are retightened,
thereby securing the counterweight support structure to the
universal crossing gate arm 6.
[0029] In accordance with another embodiment of the invention, the
elongated shaft is smooth and is secured to the support plate 36 by
a mechanical fastener that is either positioned between the support
plate 36 and a side of the universal crossing gate arm 6 or
adjacent to a side of the support plate 36.
[0030] In accordance with another embodiment of the invention, the
pinion gear 40 is located adjacent to only one elongated shaft
26.
[0031] In accordance with yet another embodiment of the invention,
the gear rack 18 and beam 24 are cast with the universal crossing
gate arm 6.
[0032] In accordance with yet another embodiment of the invention,
the gear rack 18 and beam 24 are welded and/or mechanically
fastened onto the universal crossing gate arm 6.
[0033] The accompanying figures and the description that follows
set forth this invention in its preferred embodiments. It is,
however, contemplated that persons generally familiar with railroad
crossing gates will be able to apply the novel characteristics of
the structures and methods illustrated and described herein in
other contexts by modification of certain details. Accordingly, the
figures and description are not to be taken as restrictive on the
scope of this invention, but are to be understood as broad and
general teachings.
* * * * *