US2709968A - Traction increasing devices for railroads - Google Patents

Description

June 7, 1955 W. C. COX

TRACTION INCREASING DEVICES FOR "YRAILROADS Filed Jan; 28, 1952 l INVENToR. BY h/ALTERC Cox A TTORNE'YS United States Patent O rRAcTIoN 'INCREASING DEVICES Fon RAILRoADs Walter C. Cox, Denver, Colo.

Application January 28, 1952, Serial No. 268,499

1 Claim. (Cl. 10S-75) This invention relates to improvements in railways and has reference more particularly to an improved locomotive and track by means of which greater traction can be obtained with the same weight of locomotive or tractor.

In many parts of the world there is a great need for an ecient mode of transportation, more particularly for freight. The present method of railway construction is to expensive for places that are not fully developed because the grades that can successfully'fbe traveled are limited to a few degrees and as a result of this it requires a great amount of filling, cutting and tunneling to construct a standard type of railway over hilly terrain.

This difficulty has been recognized and elevated railways have been proposed as a solution. The structure required for such railways result in prohibitive costs.

The use of rack and pinion construction has been utilized in some mountainous railway construction but merely for what may be termed scenic railways that climb to some mountain top or resort. Cog roads are limited to slow speeds.

It is the object of this invention to produce a system of railway construction that will utilize the present type of track, cars and locomotives with slight modifications to enable the train to travel over grades that are much too steep for present railroads.

Another object is to produce a railroad locomotive that can travel at normal speeds over the comparatively level sections and slow down only at steep grades.

In the standard type of railroads the traction is exerted by a locomotive employing steam, electricity or internal combustion engines for power. The tractive effort is limited to the frictional resistance between the rails and the drive wheels of the tractor and this is directly proportioned to the weight of the tractor. When such tractors or locomotives travel over level tracks the weight is perpendicular to the rail surface but when there is an upgrade the weight is divided into two components one of which is perpendicular to the track and the other parallel thereto and directed downwardly. It is evident that on an upgrade a locomotive cannot exert the same tractive effort as it can on a level track. If the weight of the tractor unit were increased to keep the component perpendicular to the rails the same as it is on a level track the component parallel with the rail surface would likewise increase.

It is the object of this invention to produce a construe tion of track and tractor by means of which the pressure of the tractive or drive wheels on the rails can be greatly increased without adding to the weight of the tractor or locomotive and thereby enable it to negotiate higher grades thereby simplifying and reducing the cost of track construction,

In order to explain the invention so that it can be readily understood reference will be had to the accompanying drawing in which the invention has been illustrated and in which,

Figure l is an illustrative view showing a train traveling up a steep grade,

Patented June 7, 1955 "ice Figure 2 is a side elevation showing the tractor or locomotive in position to exert increased rail pressure by the drive wheels per unit tractor weight,

Figure 3 is a side view to a somewhat larger scale showing the relationship between the drive wheels and the track to effect increased traction,

Figure 4 shows the relationship of the drive wheels to the track during travel over comparatively level track sections,

Figure 5 is a top plan view of a tractor truck, taken on plans 5 5 Figure 3,

Figure 6 is a force diagram illustrating the relationship of the forces during the time the increased traction arrangement is in force; and

Figure 7 is a diagram showing a slight modification.

In the drawing reference numeral 10 designates the rails of an ordinary railway track and numeral 11 designates the auxiliary rails which are provided at steep grades. The auxiliary rails are rigidly connected with rails 10 by means of bars 12, which of course, are positioned quite close together. Instead of spaced bars 12 a continuous plate may be used.

The locomotive or tractor car 13 has been illustrated as an ordinary coach body and carries the power plant which has been designated by numeral 14 in Figures 3 and 4. Any suitable power may be used such as steam, gasoline engine, diesel engine or electric motor. The tractor car is provided with novel trucks of which two have been shown.

The construction of the truck will now be described; it is to be understood, however, that only such parts have been shown as are necessary to explain the principle on which it operates. Each truck consists of five pairs of wheels each pair being secured to an axle. There are three pairs of drive wheels for each truck; one pair has been designated by reference numeral 15, two pairs by numeral 16 and two other pairs by numeral 17. The axles have not been designated by any numerals. The wheels are interconnected by means pairs of levers 18 and 19 each pair being fulcrumed at approximately its center point on the axle connecting the pairs of drive wheels 16. The intermediate ends of the pairs of levers overlap as shown in Figure 5 and are connected by the axle of the wheel pair 15. Wheels 17 are journaled in the outer ends of levers 18 and 19. The body of the tractor is supported from the axle of wheels 15 by brackets 20. Under normal conditions all six wheels 15 and 16 rest on rails 10 as shown in Figure 4. Wheels 15 are rotated by power from engine 14 by means of a sprocket chain 21 which engages sprocket wheel 22 on the shaft and wheels 16 are rotated from the driven shaft by sprocket chains 23. The drive shown is illustrative only. Since wheels 15 and 16 are the same size they all have to rotate at the same speed. Wheels 17 have not been shown as driven but they may be rotated from the adjacent driven axles, as for example, by a crossed belt or its equivalent. The gear ratio must be such as to produce the same peripherial speed as that of the other drive wheels. The belt drive just referred to has been indicated by dotted lines 24 in Figure 5. Each pair of levers 1S and 19 is joined by a bar 25 that are engaged by the ends of the semi-elliptical springs 26 that are carried by brackets 20 and normally rest on these bars. When the tractor travels over a level or slightly inclined portion of the track the parts are as in Figure 4. At steep grades the track is provided with auxiliary rails 11. Under normal operations the highest point of the peripherial surfaces of wheels 17 is spaced a distance a from the top of rails 10. The distance between adjacent surfaces of rails 10 and 11 is less than a by a distance x or (a-x). The ends of rails 11 are curved upwardly as indicated at 27. When the locomotive or tractor reaches that part of the road where rail ll begins, wheels 17 will engage rails 11 and be moved downwardly a distance x thereby'tilting the levers on their fulcrums and raise wheels 15 from rails 10, as shown in Figure 3. Since the weight of the tractor is transmitted to the axle of wheels 15 by brackets 20 wheels 16 and 17 exert a force that tends to increase the distance between rails 1i) and 11 with the result that, if the lever arms are equal and the Weight transmitted to the axle of wheels 1S is'ZW the forces will be distributed as in Figure 6. The pressure exerted .on rails 10 by wheels 16 will now be 4W which is equivalent to doubling the weight of the tractor.

Under the conditions shown in Figure 4 a portion of the weight is transmitted to wheels 16 and by properly designing the spring and positioning it the weight can be equally distributed between wheels 15 and 16.

The modification illustrated in Figure 7 shows a four wheel truck to which the weight from the tractor is transmitted by brackets 20. The distance from rail 10 to the tops of wheels 17a is greater than the distance between the two rails and, therefore, a spring must be exed when the truck enters between the rails into the position and this produces a force that is transmitted to wheels 16 and rail 1G. The value of this force depends on the strength of the spring and the amount of exure.

What is claimed is:

A railway comprising an upwardly inclined track 'having two horizontally spaced rails, each rail having another rail directly above it uniformly spaced therefrom and rigidly connected therewith, a railway car having a supporting `truck having three pairs of drive 'wheels normally resting on the rst mentioned rails, the diameters of the drive wheels being less than the distance between the vertically spaced rails, the axles of the three pairs of wheels being interconnected at each end by levers, one end of each lever being pivoted to the intermediate axle and pivoted intermediate their ends to the other axles, the other ends `of Vthe v'1eversflbeing.interconnected by axles each of which has a pair of -wheels positioned to engage the upper rails, .the normal distance between a plane tangent to the bottoms of the three pairs of wheels that normally rest ,on the under rail and a plane ltangent to the tops of the wheels ,carried by the ends of the levers being greater than the distance between the upper and lower rails, whereby when the truck is positioned between the upper and lower rails the intermediate pair of drive wheels will beraised out of contact with the lower rail, and means for supporting the weight of the car from the intermediate axle, whereby ythe pressure between the drive wheels resting on the rails will be increased.

'References Cited in lthe -le of this patent UNITED STATES PATENTS 9,652 'French June 22, 1852 715,791 Happe Dec. 16, 1902 1,024,084 Kinter Apr. 23, 1912

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