BRIEF DESCRIPTION OF THE DRAWINGS
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:
FIG. 1 is an isometric view of a portion of an automatic railroad crossing gate in accordance with one embodiment of the invention;
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;
FIGS. 3A and 3B are left and right side elevation views of the universal crossing gate arm shown in FIG. 2, and
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
In accordance with another embodiment of the invention, the pinion gear 40 is located adjacent to only one elongated shaft 26.
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.
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.
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.
Patent Application
20080093509
