Railcar draft gear assembly
09789888 ยท 2017-10-17
Assignee
Inventors
- Donald E. Wilt (Batavia, IL, US)
- Robert J. Pokorski (Saint Charles, IL, US)
- Keith A. Salis (Clare, IL, US)
- Erich A. Schoedl (Yorkville, IL, US)
Cpc classification
International classification
Abstract
A railcar draft gear assembly specifically designed to consistently and repeatedly withstand up to about 110,000 ft-lbs of energy imparted thereto while not exceeding a force level of 900,000 lbs. and while having a wedge member of the draft gear assembly travel in an inward axial direction of less than about 4.5 inches relative to an open end of the draft gear.
Claims
1. A railcar draft gear assembly, comprising: a hollow metal housing open at a first end and closed toward the second end thereof, with the housing being configured to fit within the pocket defined by the centersill on the railcar, with the housing defining a series of tapered longitudinally extended inner surfaces opening to and extending from the first end of the housing; a series of friction members equally spaced about a longitudinal axis of the draft gear assembly toward the first end of the housing, with each friction member having axially spaced first and second ends and an outer surface extending between the ends, with the outer surface on each friction member being operably associated with one of the tapered longitudinally extended inner surfaces on the housing so as to define a first angled friction sliding surface therebetween; a wedge member arranged for axial movement relative to the first end of the housing, with a free end of said wedge member axially extending from said housing and against which an external force is applied during operation of the railcar, with the wedge member defining a series of outer tapered surfaces equally spaced about the longitudinal axis of the housing, with each outer tapered surface on the wedge member being operably associated with an inner surface on each friction member so as to define a second angled friction sliding surface therebetween and such that the wedge member produces a radially directed force against the friction members upon movement of the wedge member inwardly of the housing; a spring seat arranged within the housing, with one surface of the spring seat being arranged in operable engagement with the second end of each friction member; a spring assembly disposed in the housing between the closed end of the housing and a second surface of the spring seat for storing, dissipating and returning energy imparted to the draft gear assembly by the coupler, with the spring assembly comprising a axial stack of individual elastomeric springs and with said spring assembly further including a rigid separator plate disposed between two individual and axially adjacent springs in said axial stack of elastomeric springs so as to create different dynamic elastic absorption characteristics on opposite sides of the separator plate whereby optimizing dynamic lost work opportunities during an impact event of the draft gear assembly; and wherein the spring assembly is configured to function in operable combination with the disposition of the first and second angled sliding surfaces relative to the longitudinal axis of the draft gear assembly such that said draft gear assembly consistently and repeatedly withstands about 70,000 ft-lbs. to about 85,000 ft-lbs. of energy imparted to the draft gear assembly while not exceeding a force level of 600,000 lbs. over a range of travel of the wedge member in an inward axial direction relative to the housing approximating 3.5 inches.
2. The railcar draft gear assembly according to claim 1, wherein the first angled friction sliding surface of the draft gear assembly is disposed at an angle ranging between about 1.5 degrees and about 5 degrees relative to the longitudinal axis of the draft gear assembly.
3. The railcar draft gear assembly according to claim 1, wherein the second angled friction sliding surface of the draft gear assembly is disposed at an angle ranging between about 32 degrees and about 45 degrees relative to the longitudinal axis of the draft gear assembly.
4. The railcar draft gear assembly according to claim 1, wherein the elastomeric pad of each individual elastomeric spring has a Shore D hardness ranging between about 40 and 60.
5. A railcar draft gear assembly for a railcar having a centersill defining a pocket having a distance of 24.625 inches between stops thereon, comprising: a hollow metal housing open at a first end and closed toward the second end thereof and configured to fit within the pocket defined by the centersill on the railcar, with the housing defining a series of tapered longitudinally extended inner surfaces opening to and extending from the first end of the housing; a series of friction members equally spaced about a longitudinal axis of the housing toward the first end of the housing, with each friction member having axially spaced first and second ends and an outer surface extending between the ends, with the outer surface on each friction member being operably associated with one of the tapered longitudinally extended inner surfaces on the housing so as to define a first angled friction sliding surface therebetween; a wedge member arranged from axial movement relative to the first end of the housing, with said wedge member having a free end extending beyond the open end of said housing and to which an external force is applied during operation of the railcar, with the wedge member defining a series of outer tapered surfaces equally spaced about the longitudinal axis of the housing, with the outer tapered surface on the wedge member being operably associated with an inner surface on each friction member so as to define a second angled friction sliding surface therebetween and such that the wedge member produces a radially directed force against the friction members upon movement of the wedge member inwardly of the housing; a spring seat arranged within the housing, with one surface of the spring seat being arranged in operable engagement with the second end of each friction member; a spring assembly including an axial stack of elastomeric springs disposed in the housing between the closed end of the housing and a second surface of the spring seat for storing, dissipating and returning energy imparted to the draft gear assembly, wherein said spring assembly further includes a rigid separator plate disposed between two individual and axially adjacent springs in said axial stack of elastomeric springs so as to create different dynamic elastic absorption responses on opposite sides of the separator plate whereby optimizing dynamic lost work opportunities during an impact event of the draft gear assembly.
6. The railcar draft gear assembly according to claim 5, wherein the first angled friction sliding surface on the draft gear assembly is disposed at an angle ranging between about 1.5 degrees and about 5 degrees relative to the longitudinal axis of the draft gear assembly.
7. The railcar draft gear assembly according to claim 5, wherein the second angled friction sliding surface on the draft gear assembly is disposed at an angle ranging between about 32 degrees and about 45 degrees relative to the longitudinal axis of the draft gear assembly.
8. The railcar draft gear assembly according to claim 5, wherein said spring assembly includes an axial stack of individual elastomeric springs, with each elastomeric spring including an elastomeric pad having a generally rectangular shape, in plan, approximating the cross-sectional configuration of the hollow chamber defined by the housing whereby optimizing the capability of the spring assembly to store, dissipate and return energy imparted to the draft gear assembly.
9. The railcar draft gear assembly according to claim 8, wherein the elastomeric pad of each individual elastomeric spring has a Shore D hardness ranging between about 40 and 60.
10. A railcar draft gear assembly for a railcar having a centersill defining a pocket having a distance of 24.625 inches between stops thereon, the draft gear assembly comprising: a hollow metal housing open at a first end and closed toward the second end thereof, with the housing being configured to fit within the pocket defined by the centersill on the railcar, with the housing defining a series of tapered longitudinally extended inner surfaces opening to and extending from the first end of the housing; a series of friction members equally spaced about a longitudinal axis of the housing toward the first end of the housing, with each friction member having axially spaced first and second ends and an outer surface extending between the ends, with the outer surface on each friction member being operably associated with one of the tapered longitudinally extended inner surfaces on the housing so as to define a first angled friction sliding surface therebetween; a wedge member arranged from axial movement relative to and having a free end extending from the first end of the housing and to which an external force is applied during operation of the railcar, with the wedge member defining a series of outer tapered surfaces equally spaced about the longitudinal axis of the housing, with each outer tapered surface on the wedge member being operably associated with an inner surface on each friction member so as to define a second angled friction sliding surface therebetween and such that the wedge member causes the friction member to move radially outward upon movement of the wedge member inwardly of the housing; a spring seat arranged within the housing, with one surface of the spring seat being arranged in operable engagement with the second end of each friction member; a spring assembly disposed in the housing between the closed end of the housing and a second surface of the spring seat for storing, dissipating and returning energy imparted to the draft gear assembly by the coupler, with the spring assembly including an axial stack of individual elastomeric springs, and wherein said spring assembly further includes a rigid separator plate disposed between two individual and axially adjacent springs in said axial stack of elastomeric springs so as to create different dynamic elastic absorption reaction on opposite sides of the separator plate whereby minimizing dynamic lost work opportunities during an impact event of the draft gear assembly; and wherein the spring assembly is configured to function in operable combination with the disposition of said first and second angled sliding surfaces of said draft gear assembly such that said draft gear assembly consistently and repeatedly withstands about 70,000 ft-lbs to about 110,000 ft-lbs. of energy imparted to the draft gear assembly at a force level not to exceed 900,000 lbs. over a range of travel of the wedge member in an inward axial direction relative to the housing of at least 4.5 inches.
11. The railcar draft gear assembly according to claim 10, wherein a first group springs, disposed to one side of said separator plate have a different cumulative spring rate than a group of springs disposed to an opposite side of said separator plate.
12. The railcar draft gear assembly according to claim 11, the group of springs disposed between said separator plate and said spring seat offer less resistance to axial compression than the group of springs disposed between said opposite side of said separator plate and the closed end of said housing.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
DETAILED DESCRIPTION
(10) While this invention disclosure is susceptible of embodiment in multiple forms, there is shown in the drawings and will hereinafter be described preferred embodiments, with the understanding the present disclosure is to be considered as setting forth exemplifications of the disclosure which are not intended to limit the disclosure to the specific embodiments illustrated and described.
(11) Referring now to the drawings, wherein like reference numerals indicate like parts throughout the several views, there is shown in
(12) The centersill 14 can be cast or fabricated and has many standard features. As shown in
(13) As shown in
(14) In the embodiment illustrated in
(15) Moreover, and as shown in
(16) In the embodiment shown in
(17) In the embodiment shown by way of example in
(18) In the illustrated embodiment, the friction clutch assembly 40 further includes a wedge member or actuator 50 arranged for axial movement relative to the open end 28 of housing 20. As shown in
(19) In the embodiment illustrated by way of example in
(20) In the embodiment illustrated by way of example in
(21) Wedge member 50 is formed from any suitable metallic material. In a preferred form, and as shown in
(22) As shown in
(23) As shown in
(24) An axially elongated elastomeric spring assembly 70 is generally centered and slidable within chamber 34 of the draft gear housing 20 and forms a resilient column for storing, dissipating and returning energy imparted or applied to the free end 52 of wedge member 50 during axial compression of the draft gear assembly 10. One end of spring assembly 70 is arranged in contacting relation with the end wall 24 of housing 20. A second end of spring assembly 70 is pressed or urged against surface 64 of the spring seat 60 to oppose inward movements of the friction members 42 and wedge member 50 in response to impact forces being directed to and/or against the draft gear assembly 10.
(25) Spring assembly 70 is precompressed during assembly of the draft gear assembly 10 and serves to: 1) maintain the components of the friction clutch assembly 40, including friction members 42 and wedge member 50 in operable combination relative to each other and within the draft gear housing 20 both during operation of the draft gear assembly 10 as well as during periods of non-operation of the draft gear assembly 10; 2) maintain the free end 52 of wedge member 50 pressed against the follower 53 (
(26) In the form shown in
(27) As described in further detail below, the purpose of the separator plate 73 between the springs 72 is to provide the springs 72 with different dynamic elastic absorption characteristics on opposite sides of the separator plate 73 so as to optimize dynamic lost work opportunities during an impact event of the draft gear assembly 10. To effect such desirous ends, the separator plate 73 is extremely rigid and is preferably formed from steel or the like.
(28) As shown in
(29) In a preferred embodiment, the springs 72 disposed between the lower surface 76 of plate 73 and the end wall 24 of housing 20 combine with each other to offer a greater resistance to compression than do the combination of springs 72 disposed between the upper spring engaging surface 75 of plate 73 and the spring engaging surface 64 of spring seat 60.
(30) Each cushioning unit or spring 72 includes an elastomeric pad 78. Preferably, each spring 72 has a configuration which complements the configuration, in plan, of the housing chamber 34. In a preferred form, each spring 72 has a generally rectangular shape, in plan, and is sized to optimize the rectangular area of the hollow chamber 34 wherein spring assembly 70 is slidably centered for axial endwise movements in response to loads or impacts being exerted axially against the draft gear assembly 10. Preferably, the pad 78 of each elastomeric spring 72 has two spaced and generally planar surfaces 74 and 77. As shown in
(31) Preferably, the elastomeric pad 78 and thereby each spring 72, comprising spring assembly 70 is configured such that its radial expansion, in response to impacts or loads being placed thereon, is limited by the walls of housing 20 thereby enhancing the absorption capabilities of spring assembly 70. Turning again to
(32) Preferably, each elastomeric pad 78 is formed from a polyester material having a Shore D durometer hardness ranging between about 40 and 60 and an elastic strain to plastic strain ratio of about 1.5 to 1. The working process and methodology for creating the each spring unit 72 involves creating a preform block which is precompressed to greater than 30% of the preformed height of the preform thereby transmuting the preform into an elastomeric spring.
(33) In one embodiment of the present invention disclosure, the durometer hardness of those elastomeric springs comprising spring assembly 70 may be different relative to each other. That is, the cumulative durometer hardness of the springs 72 disposed between spring seat 60 and plate 73 can be different from the cumulative durometer hardness of the springs 72 disposed between housing end wall 24 and plate 73. As mentioned, however, it is preferable for the cumulative durometer hardness of the springs 72 between the housing end wall 24 and plate 73 to be greater or harder than the cumulative durometer hardness of the springs 72 between spring seat 60 and plate 73. Such a design allows the functionality and performance characteristics of the of the draft gear assembly 10 to be fine tuned to the particular environment wherein the draft gear assembly 10 is to be used and function.
(34) As shown in
(35) As mentioned above, the purpose of the rigid separator plate 73 between the springs 72 is to provide the springs 72 with different dynamic elastic absorption characteristics on opposite sides of the separator plate 73 so as to optimize dynamic lost work opportunities during an impact event of the draft gear assembly 10.
(36) As used herein and throughout, the phrase lost work opportunity means and refers to where the force levels imparted to the draft gear assembly drop-off or fall off dramatically over a given travel. The areas shown in dash lines in
(37)
(38) Alternatively,
(39) Suffice it to say,
(40) With the present invention disclosure, and with no design changes to the centersill 14 on railcar 16, the draft gear assembly 10 is configured such that the wedge member 50 can achieve a range of longitudinal or horizontal movement in one axial direction of about 4.5 inches. That is, the draft gear assembly 10 of this invention disclosure permits 4.5 inches of travel in a buff direction and 4.5 inches of travel in a draft direction. This advantageous gain in longitudinal movement of the wedge member 50 allows the draft gear assembly 10 to consistently and repeatedly withstand between about 70,000 ft-lbs and about 110,000 ft-lbs of energy imparted thereto while not exceeding a force level of about 900,000 lbs. over a range of travel of the wedge member 50 in an inward axial direction relative to the draft gear housing 20 not exceeding 4.5 inches.
(41) From the foregoing, it will be observed that numerous modifications and variations can be made and effected without departing or detracting from the true spirit and novel concept of this invention disclosure. Moreover, it will be appreciated, the present disclosure is intended to set forth exemplifications which are not intended to limit the disclosure to the specific embodiments illustrated. Rather, this disclosure is intended to cover by the appended claims all such modifications and variations as fall within the spirit and scope of the claims.