Patent Application
20090308830
This invention relates to a pin for use in a railroad car coupler assembly.
Knuckle coupler assemblies are well known in the railway industry to attach one railroad car to another. Each railroad car to be connected to another railroad car has a coupler. The two couplers of adjacent railroad cars that are about to be coupled each have a knuckle attached to them. When the couplers go together and become coupled, the knuckles snap closed. Thus, you have two couplers, two knuckles, and two thereby formed apertures for the knuckle pins to slip into. A railroad pin is inserted into the through apertures of the knuckles to lock shut the knuckles and secure the connection between the two railcars. However, over time, the alignment of the apertures formed by the connection of the two knuckles and coupler bodies are difficult to attain because of metal wear. Misalignment of the apertures of the knuckle and coupler body reduces the area size of the overall aperture for receiving the railroad pivot pin, making installation of the pin more difficult and potentially hazardous to the railroad worker during connection of the railroad cars.
In addition, cotter pins have been previously used to hold the pivot pin within the aperture of the railroad car coupler. The continued motion of the railroad cars can wear into a specific area of the pin which can cause fatigue and breakage of the cotter pin material.
Another disadvantage of using a cotter pin to secure the pivot pin within the railroad coupler is that installing or removing the cotter pin can be difficult and dangerous to the railroad worker.
It is the intent of the subject invention to address some of the aforementioned concerns. According to one aspect of the invention a knuckle pin retainer is provided for a railroad car coupler including a pivot pin having an elongate shaft with an exterior surface extending between a first end and second end of the elongate shaft. The first end has a head disposed at the terminating end having an arcuate exterior surface. The arcuate surface terminates at a lip integrally formed to the elongate shaft. The elongate shaft has a constant diameter from the lip of the head to the terminating end of the second end. The elongate shaft further includes a cylindrical slot positioned proximate to the second end which extends through the exterior surface of the shank generally diametrically and terminating before the opposing diametric exterior surface of the shank. A retractable spring-loaded retaining member is disposed within the cylindrical slot.
The invention provides an improved knuckle pin retainer for installation in a knuckle coupler assembly for securing the connection of two adjacent railroad cars that addresses the aforementioned concerns.
Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
The knuckle pin retainer 20 of the present invention is provided to lock a railroad coupler 10 together to securely connect adjacent railroad cars. Referring to the drawings,
Referring to
At the free end 32 of the shaft 26, a slot or aperture 30 diametrically traverses the shaft 26. The aperture 30 does not extend through to the opposing surface of the shaft 26, but terminates at a point 34 adjacent to the diametrically opposing surface from the opening 36. The opening 36 to the aperture 30 has a circumferential distortion concentric and wider than the diameter of the remainder of the aperture 30. In the illustrated embodiment the circumferential distortion at the entry or opening 36 to the aperture is a beveled edge. The beveled opening 36 facilitates rotatably pressing a retaining member/latch pin 24 into the aperture 30. The beveled opening 36 terminates at a radial point 38 defining a shoulder with a reduced diameter commencing just inside the peripheral outer surface of the shaft 26. The radial point 38 forms a stop to prevent the retaining member 24 from inadvertently escaping the aperture 30 during use.
A spring 40, preferably made of stainless steel, is disposed within the aperture 30 and positioned adjacent the terminating pointed end 34 of the aperture 30. The aperture 30 is coated or filled with a lubricant, such as grease or oil at the spring 40 location to facilitate the compression and expansion of the spring 40. The lubricant also prevents corrosion from water or dirt; and further prevents winter freeze up.
The retaining member/latch pin 24 is rotatably pressed into the aperture 30 so that a rear surface 42 of the latch pin 24 lays against a first end surface 44 of the spring 40. The retaining member 24 has a tubular main body 48 with a constant diameter along the axial length of the main body 48. The diameter of the main body 48 is slightly smaller than the diameter of the aperture 30 between the radial point 38 of the beveled opening 36 and the beginning of the taper for the pointed distal end 34. Clearance between the outer surface of the retaining member 24 and the wall defining the aperture 30 allows for rotatable movement of the retaining member 24 within the aperture 30. The diameter of the main body 48 of the retaining member/latch pin 24 is predetermined to allow the latch pin 24 to rotate within the aperture 30. The rotatable attribute of the latch pin 24 minimized wear on the latch pin 24 during use. The rotational movement of the spring-loaded latch pin 24 also allows for the latch pin 24 to rotatably maneuver within the cavities (not shown) in the wall of the aperture 16 formed by the yolk 12 and coupler 14. Further the ability to rotate facilitates the entry and removal of the retaining member/latch pin 24 from the aperture 30.
The retaining member/latch pin 24 further includes a nose portion 50 integrally formed at the front end 49 of the main body 48. The nose portion 50 has a reduced diameter from the main body 48. The diameter of the nose portion 50 is constant until it terminates at the ball nose 52 which has an arcuate end surface with a radius equaling the radius of the nose portion 50. The arcuate end surface of the ball nose 52 allows the retaining member 24 to easily slide within the through aperture 16 and its cavities (not shown) of the railroad car coupler 10. As the retaining member 24 enters and leaves the coupler 10, the rotational ability of the latch pin 24 minimizes wear along any single surface of the latch pin 24.
Further, as the latch pin 24 enters the through aperture 16 of the coupler 10, the arcuate surface of the ball nose 52 glides over the entry edges to the aperture 16 to prevent nicks and gorges to the latch pin 24. This is especially advantageous when the latch pin 24 has not been fully depressed into slot 30 before the knuckle pin retainer 20 is inserted into the aperture 16 of the coupler 10.
In the prior art, cotter pins have been used with the knuckle pin retainer 20. However, cotter pins do not have the ability to rotate and therefore quickly wear along one surface area during use and when requiring replacement. Further cotter pins require additional manual labor to insert the cotter pin after the pivot pin 22 is installed.
The lengths of the retaining member/pin 24 and spring 40 with the described configuration are such that when the spring 40 is in its normal biased position, the nose portion 50 extends beyond the beveled opening 36 of the aperture 30. In the biased position, the spring 40 urges the retaining member 24 out of the aperture 30. The front end 49 of the main body 48 of the latch pin 24 is stopped by the reduced diameter formed at the radial point 38 of the beveled opening 36. The radial point 38 anchors the retaining member/latch pin 24 and prevents inadvertent removal of the latch pin 24.
The retaining member/latch pin 24 is made of a corrosive resistant material that is plated with a zinc or cadmium material with a di-chromate bake. The resultant latch pin 24 has a gold or yellow hue that is highly visible in contrast to the steel material of the remaining components of the knuckle coupler. This is especially useful during inspection of the railroad cars to check the condition of the latch pin 24. The material of the retaining member/latch pin 24 also provides anti-corrosive properties.
When the shaft 12 is installed in the railroad car coupler 10, the retaining member 24 is retracted into the aperture 30 and thereby compresses the spring 40, as shown in
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law
