US3179067A

US3179067A - Railway car

Info

Publication number: US3179067A
Application number: US192124A
Authority: US
Inventors: Merrill G Beck; James W Sherrick
Original assignee: Lord Manufacturing Co
Current assignee: Lord Manufacturing Co
Priority date: 1962-05-03
Filing date: 1962-05-03
Publication date: 1965-04-20
Anticipated expiration: 1982-04-20

Description

April 20, 1965 M. G- BECK E1AL 3,179,067

RAILWAY CAR Filed May 3, 1962 United States Patent 3,179,067 RAILWAY CAR Merrill G. Beck, Erie, and James W. Sherrick, Edinboro, Pa., assignors to Lord Manufacturing Company, Erie, Pa., a corporation of Pennsylvania Filed May 3, 1962, Ser. No. 192,124 3 Claims. (Cl. 105-368) This invention is a structure for applying shock protection to a railroad car to protect the lading from impact or humping forces. It is a system which uses mountings between the car frame and lading platform, container, and the like, in which the mountings are stiff in a vertical direction to avoid resonance with the more severe track induced vibration and which are soft in a longitudinal direction so the entire load carrying structure may yield under impact or humping forces.

In the drawing, FIG. 1 is a side elevation of a railway car, FIG. 2 is a side elevation of one of the mountings, FIG. 3 is an end elevation of the mountings, FIG. 4 is a section on line 44 of FIG. 5, and FIG. 5 is a perspective of one of the mountings showing the connection to the load carrying structures and the car frame.

The invention is shown applied to a railway car in which the load carrying structure is a three deck frame for automobiles. In this frame there are two rows of a plurality of vertical posts 1 supporting three pairs of

longitudinal members

2, 3, 4 for automobiles 5. Each pair of

members

2, 3, 4 is spaced to receive the wheels of an automobile. Suitable bracing 6 is provided. The resultant frame will carry twelve to fifteen passenger automobiles, depending upon the size. The structure so far described is of common construction.

In railway cars, there are track induced vibrations in a vertical direction which develops relatively high amplitude in the car within the frequency range of from two to seven cycles per second and there are impact forces in a fore and aft or longitudinal direction, resulting from impact or humping of the car during switching operations. The impacts would result in forces of from ten to twenty g if the load carrying structure were not cushioned.

FIGS. 2 and 3 show the mounting elements for providing the required cushioning and at the same time avoiding resonance with the track frequencies in addition to carrying the load being protected. The mounting elements comprise a bottom plate 7 with downwardly extending mounting studs 10. Other means of attaching the plate may be used. Between the plates is a body 11 of elastomer in which are embedded a plurality of plates or shims 12 parallel to the top and bottom plates 7 and 9. The elast-omer 11 is bonded to the opposite surfaces of the plates 12 and to the opposed surfaces of the plates 7 and 9. The purpose of the plates 12 is to increase the stiffness of the mounting in the vertical direction (perpendicular to the plates) while permitting the mounting to be soft in a horizontal direction (lengthwise or crosswise of the plates). In the horizontal direction, the elastomer is stressed in shear while in the vertical direction the elastomer is stressed in compres sion. The bonding of the elastomer to the plates 12 constrains the elastomer and limits bulging under compression load, thereby increasing the stiffness. The plates have negligible effect on the horizontal stiffness where the elastomer is stressed in shear.

The mounting elements may be installed as shown in FIGS. 4 and 5 spaced at convenient points for load dis tribution such as under each of the posts 1. The bottom plate 7 is bolted or otherwise attached to one of the longitudinal frame members 13 of the car and the top plate 9 is bolted to a plate 15 fixed to the lower end of the post 1. Each mounting element is enclosed in a longitudinally extending channel 16 with the bottom wall 17 underlying the bottom mounting plate 7 and resting on the car frame 13 and with sides 18 spaced from the sides of the mounting element. At the top of the sides 18 are inwardly extending flanges 19 which overlap the top plate 9 of the mounting element and provide limiting or safety stops. The channel 16 extends lengthwise of the car frame 13 and the length of the channel is such that in all positions of the mounting element under load, the greater part of the top plate 9 of each mounting element is contained within the channel and the top and bottom plates 7 and 9 are always in at least partial overlapping relation. Suitable stops, either rigid or flexible, may be provided at the ends of the channel 16 if desired.

Under all vertical load, the mounting elements are so still that the natural frequency of the load carrying structure is well above the predominant track induced frequencies. The natural frequency in the vertical direction can be of the order of eight to twenty cycles per second, which is safely above the predominant track induced frequencies in the range of two to seven cycles per second. Accordingly, so far as track induced vibrations are concerned, the mountings behave as substantially rigid connections. In a horizontal direction, the mounting elements are sufficiently soft to prevent damage due to impact. These impacts are in a longitudinal or fore and aft direction and arises during switching or humping. At an impact or humping speed of ten miles per hour (an abnormally high speed) the mounting yields substantially eight inches in a longitudinal direction, thereby limiting the impact transmitted to the rack to the safe value of substantially four g. If the mountings were omitted and the rack rigidly connected to the frame, the forces reaching the load carrying structure would be of the order of fifteen to twenty g. Forces of four g are readily withstood by most lading while forces of ten g are large enough to cause damage.

The large horizontal deflection encountered during impact or humping requires that the mounting be substantially longer than the maximum deflection. Under the maximum deflection conditions shown in FIG. 2, the mounting deflects to the position indicated by

dotted lines

19, 20, 21 and in this position substantially five inches of the top plate 9 overlaps the bottom plate 7 so there is still a substantial body of rubber in direct load carrying relation between the top and bottom plates 7 and 9. This body of rubber in side elevation is defined by the

rectangle

22, 23, 24, 25. Although the rubber in the

rectangle

22, 23, 24, 25 is substantially three inches in total thickness, the plates 12 stiffen the rubber under ,vertical load so it provides ample support for stability. If this same deflection were attempted crosswise of the car frame, the top plate 9 of the mounting element would be almost five inches beyond the bottom plate 7 and no part of the body 11 would be in load carrying relation between the plates. Large forces sidewise of the car frame do not occur in service and deflection of the mounting elements in the sidewise direction is limited by the sides 18 of the channel 16.

In a specific example, the rack when loaded with twelve automobiles weighed 83,500 pounds. There were 18 posts with a mounting under each post. The combined stiffness of the 18 mountings in the fore and aft direction was 24,000 lbs/inch. The stiffness of the 18 mountings in the vertical direction was 45 0,000 lbs./ inch. At 8 miles per hour, the impact energy was 2,160,000 inch lbs. and the impact transmitted to the rack was 210,000 inch pounds at a deflection of approximately 8.00 inches. The vertical natural frequency was approximately 8 cycles per second which was safely above the predominant track induced frequencies. The horizontal natural frequency was approximately two cycles per second but in railway cars there are no large horizontal vibration exciting forces.

*From one aspect, the automobile carrying frame is a specialized rack-like structure for multiple lading supportedivertically by elastomeric mountings which carry the load in compression and deflect in shear to cushion the rack from longitudinal impacts; The spring rate of the mountings in the Vertical (compression) direction is at least ten times the longitudinal (shear) rate. no guides for the rack. There are no guides or positioning elements for the rack which could bind and interfere with the cushioning.

What is claimed as new is:

l. A railway car having a frame extending lengthwise of the car, an automobile carrying structure comprising a frame with two rows of vertical posts with the posts in each row spaced along the, length of and overlying the car frame and at least two pairs of longitudinal members between and connected in load carrying relation to the posts of said rows and arranged one pair above the other with each pair of members spaced to receive the wheels of an automobile, a mounting between the car frame and the lower end of each post, said mounting comprising an elongated horizontal. upper platefixed to the lower end of the post andextending lengthwise of the car frame, an elongated horizontal lower plate fixed to and extending lengthwise of the car frame, and a body of elastomer sandwiched between and bonded to said plates, the total thickness of the elastomer being at least substantially three inches and the spring rate of the elastomer being. such that the mounting deflects lengthwise at least substantially eight inches under the maximum impact arising during switching or humping, a plurality of horizontal plates spaced from each other and disposed between the top and bottom plates and embedded in and bonded to said elastomer, the spring rate of the mountings in the vertical direction being at least ten times the spring rate of the mountings in a longitudinal direction, said mountings having a natural frequency in the vertical direction above the range of the track frequencies 2 to 7 cycles per second and havingv a natural frequency in the fore and aft direction below 7 cycles per second, the length of the plates exceeding by a substantial amount the maximum lengthwise deflection under impacts arising during switching or humping so that the upper and lower plates are always in at least partial overlapping relation, and the body of rubber between the upper and lower plates provides a stable support for the structure.

2. A railway car having a frame extending lengthwise of the car and a load carrying structure mounted on the frame by a plurality of mountings in load carrying relation between the frame and the structure, said mountings having a natural frequency in the vertical direction above the range of the track frequencies 2 to 7 cycles per second and having a natural frequency in the fore and aft direction below 7 cycles per second, said mountings comprising spaced horizontal plates extending lengthwise of the car frame and arranged one above the other with the upper plate connected to the load carrying structure and the lower plate connected to the frame and with a body of elastomer sandwiched between and united to the upper and lower plates, the total thickness of the elastomer being .atleast substantially three inches and There are the spring rate of the elastomer being such that the mount ing deflects length-wise at least substantially eight inches under the maximum impact arising during switching or humping, a plurality of horizontal plates spaced from each other and disposed between the top and bottom plates and embedded in and bonded to said elastomer, the spring rate of the mounting-s in the vertical direction being at least ten times the spring rate of the mountings in a longitudinal direction, the length of the upper and lower plates exceeding by a substantial amount the maximum lengthwise deflection under impacts arising during switching or humping so that the plates are always in at least partial overlapping relation and the body of rubber between the upper and lower plates provides a stable support for the structure.

' 3. A railway car having a frame extending lengthwise of the car, a load carrying structure, a plurality of mountings formin the entire load carrying connection between the car frame and the structure inthe normal static position and during normal impacts, said mountings having a natural frequency in the vertical direction above the range of the track frequencies 2 to 7 cycles per second and having an-atural frequency in the fore and aft direction below 7 cycles per second, each mounting comprising an elongated horizontal upper plate fixed tothe structure and extending lengthwise of the car frame, an elongated horizontal lower plate fixed to and extending lengthwise of the car frame, and a body of elastomer sandwiched between and bonded to said plates, a plurality of horizontal plates spaced from each other and disposed between the top and bottom plates and embedded in and bonded to said elastomer, the total thickness of the elastomer being at least substantially three inches and the spring rate of the elastomer being such that the mounting deflects lengthwise at least substantially eight inches under the maximum impact arising during switching or humping, the spring rate of the mountings in the vertical direction being at least ten times the spring rate of the mountings in a longitudinal direction, and the length of the upper and lower plates exceeding by a substantial amount the maximum deflection under impacts arising during switching or humping so that the plates are always in at least partial overlapping relation, and the body of rubber between the upper and lower plates provides a stable support for the structure.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCES 7 Article entitled Frisco tri level Auto Car in Railway Age, February 15, 1960, page 23.

Article entitled Whats New In Rolling Stock, Railway Age, February 15, 1960. i

LEO QUACKENBUSH, Primary Examiner.

Claims

2. A RAILWAY CAR HAVING A FRAME EXTENDING LENGTHWISE OF THE CAR AND A LOAD CARRYING STRUCTURE MOUNTED ON THE FRAME BY A PLURALITY OF MOUNTINGS IN LOAD CARRYING RELATION BETWEEN THE FRAME AND THE STRUCTURE, SAID MOUNTINGS HAVING A NATURAL FREQUENCY IN THE VERTICAL DIRECTION ABOVE THE RANGE OF THE TRACK FREQUENCIES 2 TO 7 CYCLES PER SECOND AND HAVING A NATURAL FREQUENCY IN THE FORE AND AFT DIRECTION BELOW 7 CYCLES PER SECOND, SAID MOUNTINGS COMPRISING SPACED HORIZONTAL PLATES EXTENDING LENGTHWISE OF THE CAR FRAME AND ARRANGED ONE ABOVE THE OTHER WITH THE UPPER PLATE CONNECTED TO THE LOAD CARRYING STRUCTURE AND THE LOWER PLATE CONNECTTED TO THE FRAME AND WITH A BODY OF ELASTOMER SANDWICHED BETWEEN AND UNITED TO THE UPPER AND LOWER PLATES, THE TOTAL THICKNESS OF THE ELASTOMER BEING AT LEAST SUBSTANTIALLY THREE INCHES AND THE SPRING RATE OF THE ELASTOMER BEING SUCH THAT THE MOUNTING DEFLECTS LENTHWISE AT LEAST SUBSTANTIALLY EIGHT INCHES UNDER THE MAXIMUM IMPACT ARISING DURING SWITCHING OR HUMPING, A PLURALITY OF HORIZONTAL PLATES SPACED FROM EACH OTHER AND DISPOSED BETWEEN THE TOP AND BOTTOM PLATES AND EMBEDDED IN AND BONDED TO SAID ELASTOMER, THE SPRING RATE OF THE MOUNTINGS IN THE VERTICAL DIRECTION BEING AT LEAST TEN TIMES THE SPRING RATE OF THE MOUNTINGS IN A LONGITUDINAL DIRECTION, THE LENGTH OF THE UPPER AND LOWER PLATES EXCEEDING BY A SUBSTANTIAL AMOUNT THE MAXIMUM LENGTHWISE DEFLECTION UNDER IMPACTS ARISING DURING SWITCHING OR HUMPING SO THAT THE PLATES ARE ALWAYS IN AT LEAST PARTIAL OVERLAPPING RELATION AND THE BODY OF RUBBER BETWEEN THE UPPER AND LOWER PLATES PROVIDES A STABLE SUPPORT FOR THE STRUCTURE.