Patent Grant
7383961
The present invention relates, in general, to draft gear assemblies for use in cushioning both buff and draft shocks normally encountered by railway rolling stock during make-up and operation of a train consist on a track structure and, more particularly, the present invention relates to a draft gear assembly having plates, particularly the tapered plates, wherein a portion of a lugs supporting the plates is tapered or angled to increase the side force from the wedge shoe to the movable plate which, in turn, increases the draft gear assembly's resistance to closure and increases the capacity of the draft gear assembly.
Draft gear assemblies which utilize friction-type clutch mechanisms to absorb heat energy generated during service have been in widespread use in the railroad industry for many years to absorb both buff and draft shocks applied to the railway rolling stock. Many of such draft gear assemblies which were in use, prior to the present invention, are taught in U.S. Pat. Nos. 2,916,163; 3,178,036; 3,447,693; and 4,645,187. Each of the above-identified patents is owned by the assignee of the present invention. The teachings of each of these patents are all incorporated into the present application by reference thereto.
These draft gear assemblies are designed to receive coupler forces and dissipate them without damage to the car structure and lading. The assemblies are disposed within an elongated opening located in the center sill member of the railway car along the longitudinal axis thereof and behind the shank, or innermost end, of the railway car's coupling mechanism. In this position, these friction clutch type draft gear assemblies will absorb at least a relatively large portion of both the buff and draft forces generated during service. Such buff and draft forces encountered by such railway cars are usually being applied in an alternating manner to the center sill member during normal car operation on the track.
It is well recognized in the art that these draft gear assemblies must be provided with the capability of maintaining at least a certain minimum shock absorbing capacity both during making up a train consist and in-track service. Such minimum capacity has been specified by the Association of American Railroads (AAR) and is defined in the standards issued by the AAR. For example, friction clutch type draft gear assemblies have a specified absolute minimum capacity rating of at least 36,000 foot pounds. Any draft gear assembly with a capacity rating which is determined to be below 36,000 pounds will not receive approval from the AAR for service on any railroad car which may be used in interchange.
It is, likewise, important to note that the heat energy absorbing action of the friction clutch mechanism must enable this minimum capacity rating to be readily achieved without exceeding a specified maximum 500,000 pound reaction force, or pressure, being exerted on the center sill member of the railway car during both such make-up and operation of such train consist. It has been found that such maximum reaction pressure is required to enable these high energy shocks to be readily absorbed without upsetting the end of the coupling member shank and/or damaging other critical car components and/or lading that is being transported by such railway car.
In order for the manufacturers of such friction clutch type draft gear assemblies to meet the requirements of the railroad industry, with the ever increasing load carrying capacity of their modern day railroad cars, it has become of extreme importance to enhance the overall rated capacity of the friction-type draft gear assemblies as much as possible. This higher capacity rating being found necessary in order to minimize any damage to such cars and/or the lading due to the increased forces being exerted on the center sill member of the cars by the heavier loads such cars are now carrying.
It is therefore an object of the invention to produce a draft gear assembly having an increased capacity and resistance to closure.
It is a further object of the invention to provide a draft gear assembly wherein an additional side force is applied to the movable plates from the tapered plate.
It is still yet a further object of the invention to provide the lugs supporting the tapered plate with a tapered portion to increase the side force on the movable plate which increases the draft gear assembly's resistance to closure and increases the capacity of the draft gear assembly.
It is still yet a further object of the invention to provide a draft gear assembly wherein an angle is provided on the portion of the lug supporting the tapered plate which cooperatively contacts the third housing rib so as to increase the side force on the movable plate, increasing the capacity of the draft gear and providing a greater resistance to closure.
It is yet a further object of the invention to provide a draft gear assembly having tapered plates wherein a portion of a horizontal housing rib supporting the lugs of the tapered plates is tapered or angled to increase the side force on the movable plate which increases the draft gear assembly's resistance to closure and increases the capacity of the draft gear assembly.
It is an additional object of the invention to provide tapered lugs supporting plates in split wedge draft gears in order to increase the side force from the friction wedge means to the friction plate which increases the draft gear assembly's resistance to closure and increases the capacity of the draft gear assembly.
Briefly, and in accordance with the forgoing objects, the invention comprises a draft gear assembly comprising a housing closed at one end and open at the opposed end and having a rear portion adjacent the closed end and a front portion adjacent the open end, a compressible cushioning element centrally disposed within the rear portion abutting the housing end and extending longitudinally there from, a seat means abutting the opposite end of the compressible cushioning element during application and release of a force on the draft gear assembly, and a friction cushioning means positioned at least partially within said front portion of said housing for absorbing energy during a compression of said draft gear assembly. The friction cushioning means includes a pair of laterally spaced outer stationary plates having an outer surface for engaging the housing and an opposed inner friction surface, a pair of laterally spaced movable plates having an outer friction surface for movably engaging the outer stationary plates, an inner friction surface and at least one substantially flat edge intermediate the outer friction and inner friction surfaces for engaging the seat means. The friction cushioning means also includes a pair of laterally spaced tapered plates having lugs for supporting the tapered plates within the housing. The lugs of the tapered plate are tapered or angled to increase the side force on the movable plate. The tapered plates have an outer friction and an inner friction surface wherein the outer friction surface movably and frictionally engages the inner friction surface of the movable plate. The friction cushioning means further includes a pair of laterally spaced wedge shoes having an outer friction surface for movably and frictionally engaging an inner friction surface of the tapered plate and a center wedge having a pair of matching predetermined tapered portions for engaging the tapered portion of the wedge shoe to initiate frictional engagement of the friction cushioning means and thereby absorb energy. The housing includes three horizontal ribs for positioning and/or holding the components of the cushioning means. A spring release means is provided which engages and longitudinally extends between the seat means and the center wedge for continuously urging the friction cushioning means outwardly from the compressible cushioning means to release the friction cushioning element when an applied force compressing the draft gear is removed.
The present invention increases the capacity and resistance to closure of the draft gear assembly wherein a portion of the lug supporting the tapered plates is tapered or angled to increase the side force on the movable plate which increases the draft gear assembly's resistance to closure and increases the capacity of the draft gear assembly. Additionally or alternatively a tapered or angled top surface on the housing's third horizontal rib may be provided in the area that contacts or supports the lugs of the tapered plates. Providing a taper on the third horizontal rib which mates or cooperates with an angle on the lugs of the tapered plates increases the side force on the movable plates during the application of a buffing shock to the draft gear assembly.
The present invention is also applicable to split wedge draft gears wherein the lugs, which support the plate means positioned on either side of the friction plate, are tapered to increase the side force transferred from the wedge means to the friction plate.
Although a number of objects and advantages of the present invention have been described in some detail above, various additional objects and advantages of the draft gear assembly of the present invention will become more readily apparent to those persons who are skilled in the art from the following more detailed description of the invention, particularly, when such detailed description of the invention is taken in conjunction with both the attached drawing figures and with the appended claims.
The draft gear assembly, according to the present invention, is installed in alignment with a railroad car center sill between a front and a rear draft gear lug. A vertical yoke is connected to a coupler shank by a draft key with a coupler horn spaced from a striking plate and with a front follower member within the yoke which is positioned adjacent to the front lugs, all substantially in accordance with the prior art conventional practice as illustrated in the aforementioned U.S. Pat. No. 2,916,163.
Prior to proceeding to the more detailed description of the various embodiments of the instant invention, it should be pointed out that, for the sake of clarity, identical components which have identical functions have been identified with identical reference numerals throughout the several views that have been illustrated in the drawings.
Now reference is made, more particularly, to drawing
The compressible cushioning element 26 is centrally disposed within the rear portion 14 and has one end thereof abutting at least a portion of an inner surface 28 of the bottom wall 16 of housing 12. The compressible cushioning element 26 extends longitudinally from bottom wall 16 where the opposite end is placed into abutting relationship with at least a portion of one surface 30 of a seat means 32. Seat means 32 is positioned within the housing 12 for longitudinal movement therein for respectively compressing and releasing the compressible cushioning element 26 during application and release of a force on the draft gear assembly 10.
As shown in
A friction cushioning means, generally designated as 40, is positioned at least partially within the front portion 18 of the housing 12. The friction cushioning means 40 absorbs energy during application of a force sufficient to cause a compression of the draft gear assembly 10.
The friction cushioning means 40 includes a pair of laterally spaced outer stationary plates 42 having an outer surface 44 and an opposed inner friction surface 46. The outer surface 44 engages the housing 12. A pair of laterally spaced movable plates 48 of substantially uniform thickness is also provided. Movable plates 48 have an outer friction surface 50 and an inner friction surface 52 and at least one substantially flat edge 54 intermediate the outer friction surface 50 and the inner friction surface 52 which edge 54 engages the seat means 32. At least a portion of the outer friction surface 50 movably and frictionally engages the inner friction surface 46 of the outer stationary plate 42. A pair of laterally spaced tapered plates 56 is provided. The tapered plates 56 include an outer friction surface 58 and an inner friction surface 60. The outer friction surface 58 movably and frictionally engages at least a portion of the inner friction surface 52 of the movable plate 48. As shown in
It has been discovered that providing an angle or taper 25 on the top surface of the third horizontal rib 24 and correspondingly providing an angle or taper on the lug 63 of the tapered plates 56 in the area that contacts this tapered top surface 25 of the third horizontal lug 24 of the housing 12, results in a greater side force being applied to movable plates 48 by enhancing the force transfer from the wedge shoes 64 to the movable plates 48. Thus, the capacity of the draft gear and its resistance to closure is increased. A spring release means 76 engages and extends longitudinally between the seat means 32 and the center wedge 72 for continuously urging the friction cushioning means 40 outwardly from the compressible cushioning means 26 to release the friction cushioning means 40 when an applied force compressing the draft gear assembly 10 is removed.
The present invention may also be applied to a split wedge type draft gear having a center friction plate such as shown in
As shown in
A friction cushioning means, generally indicated as 80 is positioned at least partially within the front portion 78 of the housing for absorbing energy during a compression of the draft gear assembly. The friction cushioning means includes a friction plate means 22a centrally disposed within the front portion of the housing. The friction plate means 22a has a first end which extends out of the housing 24a and a second end which contacts the seat means 46a. A first and second barrier plate means 48a and 50a are disposed one on either side of the friction plate 22a. The first and second barrier plate means 48a, 48b include lugs 98, as shown in
The friction cushioning means further includes first and second friction wedge means 18a and 18b. The first friction wedge means 18a is disposed on one side of the first barrier plate means 48a and the second friction wedge means 18b is disposed on one side of the second barrier plate means 48b. A first and second shoe means 60a and 60b are provided wherein the first shoe means 60a is disposed on one side of the first friction wedge means 48a and the second shoe means 60b is disposed on one side of the second friction wedge means 48b. The friction cushioning means also includes first and second wear liner plate means 68a and 68b. The first wear liner plate means 68a is disposed on one side of the first shoe means 60a and the second wear liner plate means 68b is disposed on one side of the second shoe means 60b. In addition to the angled lug 98 of the barrier plates, at least one horizontal rib contacting the angled portion of the lug can be cooperatively angled.
Thus, the present invention has been described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same. It will be understood that variations, modifications, equivalents, and substitutions for components of the specifically described embodiments of the invention may be made by those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.
This application claims priority from provisional application Ser. No. 60/561,048, filed Apr. 8, 2004. This application is also closely related to U.S. patent application Ser. No. 11/071,004, entitled “Taper Under Taper Plate to Increase Side Force On The Movable Plate”
| Number | Name | Date | Kind |
|---|---|---|---|
| 4645187 | Kanjo et al. | Feb 1987 | A |
| 4735328 | Carlstedt | Apr 1988 | A |
| Number | Date | Country | |
|---|---|---|---|
| 20050252873 A1 | Nov 2005 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60561048 | Apr 2004 | US |
