Coupler knuckle

An improved coupler-knuckle assembly is comprised of a coupler body, a knuckle, and at least two knuckle retainer plugs. The knuckle has an internal coring geometry that increases the cross-sectional area of the throat portion of the knuckle compared to previous designs. The present invention's knuckle design includes a top and a bottom tapered holes in the knuckle with a locking groove at the bottom of each tapered hole for the knuckle retainer plugs to snap into. The knuckle retainer plugs are inserted through the coupler body and into the tapered holes in the knuckle. The improved coupler-knuckle assembly of the present invention reduces fatigue on the coupler, knuckle, and knuckle pin, prevents misalignment of the coupler-knuckle assembly, and prevents knuckle pin breakage.

BACKGROUND OF THE INVENTION

The invention relates generally to railway car coupling systems, and more particularly to an improved cast metal coupler-knuckle assembly.

This invention is applicable to Association of American Railroads (AAR) Type E, F, and H couplers. In a standard railway coupler-knuckle assembly, a knuckle pin pivotally connects a coupler body and a knuckle. Both the coupler body and the knuckle have a pinhole that allows a single knuckle pin to pivotally secure the coupler and the knuckle together.

In the coupler-knuckle assembly design that is currently used in the railway industry, the knuckle's weakest section is in the throat area around the hole for the knuckle pin. The hole is 1 21/32 inches in diameter and goes completely through the coupler and the knuckle. The pinhole reduces the cross-section area of the knuckle's throat area, which is a highly stressed location in the coupler-knuckle assembly. Because of this weakness in the throat area of the knuckle, the current AAR cast metal coupler-knuckle assembly design does not consistently meet the AAR's newly adopted M-216 fatigue test for a coupler-knuckle assembly.

The current single style knuckle pin designs are either metallic or non-metallic. When in use, the knuckle pin can get loaded due to the misalignment of the pulling lugs and pinholes located both on the coupler body and the knuckle. The misalignment causes both the knuckle pin and the coupler-knuckle assembly to fatigue during use, and can cause damage or break the pin or assembly.

The present invention provides an improved railway coupler-knuckle assembly that strengthens the coupler-knuckle assembly and reduces fatigue on all components of the coupler-knuckle assembly.

SUMMARY OF THE INVENTION

In accordance with the present invention, an improved railway car metal cast coupler-knuckle assembly secured by two knuckle plugs instead of a single knuckle pin is provided for use.

The coupler-knuckle assembly is comprised of a coupler body, a knuckle, and at least two knuckle retainer plugs. The knuckle has an internal coring geometry that removes the knuckle pinhole that protrudes entirely through the knuckle in previous knuckle designs. The present invention's knuckle design includes a top tapered hole and a bottom tapered hole in the knuckle with a locking groove at the bottom of each tapered hole for the knuckle retainer plugs to snap into.

The knuckle retainer plugs have a top end and a bottom end, with a head on the top end, and a taper on the bottom end. On the tapered bottom end are locking tabs that snap into the locking groove at the bottom of the tapered hole in the knuckle, ensuring the knuckle is securely attached to the coupler body. The knuckle retainer plugs have relief cutouts on the head of the plugs to allow easy removal from the coupler-knuckle assembly.

It is an object of the present invention to provide a coupler-knuckle assembly with a greater cross-sectional area in the knuckle that is stronger through the knuckle throat area and consistently passes the AAR M-216 fatigue test.

It is another object of the present invention to provide a coupler-knuckle assembly with a knuckle that couples with a standard E, F, or H-type coupler,

It is another object of the present invention to provide a coupler-knuckle assembly utilizing a multi-knuckle plug design wherein the plugs are independent of each other allowing for uniform alignment of the top and bottom pulling lugs, thus, reducing fatigue on both the coupler-knuckle assembly and knuckle plugs.

It is another object of the present invention to provide a coupler-knuckle assembly utilizing a multi-knuckle plug design that eliminates knuckle pin loading and prevents bending and breakage of the knuckle pin.

It is a further object of the present invention to provide a coupler-knuckle assembly utilizing a multi-knuckle plug design that allows the knuckle plugs to remain unloaded and the coupler and knuckle pulling lugs to remain uniformly aligned during use.

It is still a further object of the present invention to provide a multi-knuckle plug coupler-knuckle assembly that can be used in current OEM coupler production or for field replacement when knuckles need to be replaced in a current revenue service.

DETAILED DESCRIPTION

Referring now toFIGS. 1-3, an E-type coupler-knuckle assembly known in the prior art is generally designated10and includes a coupler body11, a knuckle22, and a knuckle pin32. The coupler body11comprises generally a coupler head12and a coupler shank14which is adapted to be mounted on a railway car (not shown). The coupler-knuckle assembly10serves to transfer buff and draft loads that are exerted on the assembly10during use, from the knuckle22to the coupler body11, without damaging knuckle pin32.

The coupler head12has a knuckle side16and a guard arm side18. Coupler head12has a front face24including a throat portion26extending towards the knuckle side16in a curved manner toward upper pivot lug28and lower pivot lug30. Coupler head12includes outwardly protruding flange sections34and36from the top surface38of upper pivot lug28and the bottom surface64of lower pivot lug30respectively. Along with pulling and buffing loads on a coupler head12during use, a bending load is present which acts to pull upper pivot lug28away from lower pivot lug30. The flange sections34and36provide the necessary strength to prevent pivot lugs28and30from bending away from each other.

The knuckle22is inserted between upper pivot lug8and lower pivot lug30, with the upper and lower pinholes50and52in the upper and lower pivot lugs28and30respectively, aligned with pinhole54in knuckle22. The knuckle22is pivotally secured in place by knuckle pin32, that is inserted through pinholes50and52in the upper and lower pivot lugs respectively, and through pinhole54in the knuckle22. Pinholes50and52in the upper and lower pivot lugs28and30, and pinhole54through knuckle22generally have a circular cross-section that is greater than the cross-sectional area of the knuckle pin32.

Knuckle pin32comprises a longitudal cylindrical member having a length greater than that of the distance between the upper and lower pivot lugs28and30, allowing a bottom portion42of knuckle pin32to extend beyond lower pivot lug30. A cotter pin46or other locking mechanism secures knuckle pin32in place in the coupler-knuckle assembly10. The cotter pin46prevents knuckle pin32from unintentional upward removal during use, and allows knuckle pin32to rotate. At the end opposite the bottom portion42, knuckle pin32has a head44which is diametrically larger than upper pinhole50, preventing knuckle pin32from moving downward during use. The head44also allows a maintenance worker to issue downward blows on the knuckle pin32during installation of the knuckle pin32into the coupler-knuckle assembly10without damaging the knuckle pin32.

As a result of buff and draft movements during use, force and stress is exerted on the top pulling lugs60,62and the bottom pulling lugs64,66of the knuckle22, causing them to contact with top pulling lugs68,70and bottom pulling lugs72,74of the coupler body11respectively. While in use, when uneven force is exerted on the top and bottom pulling lugs of the coupler and knuckle, the coupler-knuckle assembly can become misaligned as the rigid single knuckle pin only allows one set (either the upper pulling lugs or the lower pulling lugs) of pulling lugs on the coupler and knuckle to contact. This places unwanted force on the coupler, knuckle, and knuckle pin. This force causes the knuckle22to move with respect to the coupler body11, exerting force on knuckle pin32, as well as the knuckle22and coupler body11. The area of the knuckle22that experiences the most stress from the misalignment of the coupler and knuckle is the throat area76. The throat area76of the knuckle22is the internal area of the knuckle22immediately surrounding the knuckle pinhole54. The use of a single knuckle pin32places a load on knuckle pin32when the pulling lugs become misaligned, causing fatigue and damage to the coupler, knuckle, and knuckle pin.

Referring now toFIGS. 4-7, a coupler-knuckle assembly embodying the improved design of the present invention is generally designated100and includes a coupler body102, a knuckle112, and two knuckle retainer plugs122,124. The knuckle and knuckle retainer plug design can be used in current OEM coupler production or for field replacement when knuckles need to be replaced in current revenue service. The improved knuckle couples with any Type E, F, or H couplers.

The coupler body102of the present invention includes the same components and is the same design as the prior art coupler body11Shown inFIGS. 1-3. Thus, the coupler body102includes a coupler head104and coupler shank106. The coupler head104has a knuckle side108and a guard arm side110. Coupler head104has a front face114including a throat portion116extending towards the knuckle side108in a curved manner toward upper pivot lug118and lower pivot lug120. All parts of coupler body102function the same way as described previously for prior art coupler body11.

The knuckle112of the present invention contains a top tapered hole130and a bottom tapered hole132that extend into the knuckle and towards each other, but do not connect. The tapered holes130and132are symmetrical, and contain a top locking groove138in the top tapered hole130and a bottom locking groove140in the bottom tapered hole132at the bottom of each respective hole. Both locking grooves138,140are identical. The locking grooves138,140pivotally secure the knuckle112into the coupler body102, and ensure the knuckle plugs138,140remain in place during use. A hollow shaft142that is diametrically smaller than the tapered holes134,136connects the top tapered hole134and the bottom tapered hole136. The hollow shaft142allows the internal coring geometry144of knuckle112to have a greater cross-sectional area in the throat portion145of the knuckle112. This internal coring geometry change leads to added strength and less fatigue endurance on the knuckle during use, while still making the knuckle light enough for installation purposes.

The knuckle112of the present invention is inserted between upper pivot lug118and lower pivot lug120of coupler head104, and secured into place by an upper retainer plug122and lower retainer plug124. The retainer plugs122,124include a longitudal member that serves to lock the knuckle112into the coupler body102and allow the knuckle112to pivotally move with respect to the coupler body102. Upper retainer plug122is inserted through the top plug hole130in upper pivot lug118and into top tapered hole134of knuckle112, and lower retainer plug124is inserted through bottom plug hole132in lower pivot lug120and into bottom tapered hole136. Upper retainer plug122and lower retainer plug124are secured in place by top locking groove138and bottom locking groove140respectively. The knuckle retainer plugs122,124are snapped into place by exerting pressure on the retainer plugs122,124driving it into the knuckle, with the locking tab208(FIG. 8) of the knuckle retainer plugs122,124secured into the place by the locking grooves138,140in the knuckle112.

After knuckle112is secured in place by upper and lower retainer plugs122,124, the top pulling lugs146,148and the bottom pulling lugs150,152of knuckle112are aligned with top pulling lugs154,156and bottom pulling lugs158,160of coupler body102respectively.

During use, when uneven force is exerted on the top pulling lugs of the coupler and knuckle, the coupler-knuckle assembly can become misaligned placing force on the coupler, knuckle, and knuckle pin. The inventive coupler-knuckle assembly utilizing the retainer plug design allows the retainer plugs to move independently of each other ensuring contact between both the upper pulling lugs of the knuckle and the upper pulling lugs of the coupler, and the lower pulling lugs of the knuckle and the lower pulling lugs of the coupler. Both sets of pulling lugs (upper and lower) on the coupler and knuckle remain in alignment, allowing the knuckle retainer plugs to remain unloaded during use, preventing breakage of the knuckle retainer plugs, and ensuring even load distribution during buff and draft movements.

Referring now toFIGS. 8-11, a knuckle retainer plug of the present invention designated200includes a shaft202with a bottom tapered end204and a top end206. The knuckle retainer plug200can be made of a metallic or plastic material. The shaft202is a longitudal member with a circular cross-sectional area that is smaller than that of the plug holes130,132in the pivot lugs118,120. On the bottom tapered end204there are locking tabs208that allow the knuckle retainer plug200to lock into the locking grooves138,140of knuckle112. The locking tabs208ensure that the knuckle is securely attached to the coupler body in the open, closed, or rotated positions, while still allowing the knuckle to rotate. On the top end206of the shaft202is a head210. The head210is dome-shaped and generally has a circular cross-sectional shape having a cross-sectional area greater than that of the shaft202and the plug holes130,132in the pivot lugs118,120. It is also contemplated that the present invention can have a head210that is a non-circular shape. The head210includes at least one relief or cutout212that allows a person to easily remove the knuckle retainer plug200with a pry bar, standard slotted screwdriver, or any other shaft-like tool. To remove the knuckle retainer plug from the coupler, the tip of the removal tool is inserted into the relief area beneath the head of the knuckle plug, and the removal tool is forced against the coupler body forcing the plug to unsnap from the locking groove in the knuckle. The removed knuckle retainer plug can be reused and reinserted into another coupler-knuckle assembly. The shaft202of the knuckle retainer plug200also contains relief areas214. These relief areas214allow the shaft to use less material in the molding process and allow the knuckle retainer plug200to cool faster after the molding process is complete.

While particular embodiments of the present knuckle pin have been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects.