US 3114435 A
Description (OCR text may contain errors)
A. POLLMANN 3,114,435
ACTUATING RODS FOR BRAKE BEAM RETARDER SYSTEM 2 Sheets-Sheet 1 Dec. 17, 1963 Filed Aug. 3, 1960 Inventor:-
Dec. 17, 1963 A. POLLMANN 3,114,435
ACTUATING RODS FOR BRAKE BEAM RETARDER SYSTEM 2 Sheets-Sheet 2 Fig. 4
Filed Aug- 3, 1960 1 5 42 45 43 1'2 mm 12, I I h n I36 48 13;
Jnvenfarf United States Patent i 3,114,435 ACTUATING RODS FOR BRAKE BEAM RETARDER SYSTEM Adolf Pollmann, Dinslaken, Germany, assignor to August Thyssen-Hiitte Aktiengesellschaft, Duisburg-Hamborn, Germany Filed Aug. 3, 1960, Ser. No. 48,339 Claims priority, application Germany Aug. 7, 1959 6 Claims. (Cl. 18862) The present invention relates to mechanism for actuating brake beam retarder systems associated with railroad tracks, for example in railroad shunting or marshalling yards.
The invention is characterized by a pair of rod systems extending parallel to the line of rails and including between each other the line of rails; these rods serve to actuate a beam retarder which generally has a hydraulic drive for each of the two rods. Such drives are known for beam retarders with actuating rollers supported on stirrups by swinging levers and actuated by springs. These rollers are linked by two pairs of rods which are parallel to the line of rails.
In the case of beam retarders it is important that differences in the retarding forces between the two wheels of a composition of wheels be avoided as completely as possible to avoid compression and torsional stresses on the cars. The beam retarders engaging on both sides of the wheel have a very strong retarding force, and if one of the two sides of the retarder does not work the danger of damage exists. The invention aims essentially at making it possible to avoid differences in the retarding :forces with simple means.
According to the invention, the two groups of rods operate in opposition to each other; i.e. their movements are in opposite directions. The two groups of rods are linked to each other by a compensating lever which is two-armed and supported on a fixed pivot located below the line of rails; in a preferred embodiment this lever is linked to the guide frame of a piston rod located below the rods (of the retarder).
The invention is based on the understanding that there can be a positive or negative angle formed by the swinging levers of the rollers and by the transverse plane of the line of rails; i.e. only the absolute size of the angle is important. Because of this all the individual parts necessary for the actuation can be provided in pairs; only the arrangement of the parts is rotated by 180. As the compensating lever is located lower than the rods, the invention provides straight line guiding frames with lateral and upper connecting means for overcoming the difference in height. This arrangement has the advantage that the hydraulic cylinders can be installed under the rods without enlarging the overall width of the retarder.
In a preferred construction the individual bars bridging the gaps between two stirrups have at one end a righthanded thread and at the other end a left-handed thread. The individual bars then act as turnbuckle sleeves and allow an exact adjusting of all swinging levers. Moreover, any subsequent adjustment of the bars serving as turnbuckles readily compensates the relatively substantial wear of the brake beams upon first putting them in service retarder.
It also is advisable to make the roller way for each roller concavely curved in such a way that the adjusting movement of the brake beam is proportional to the movement of the driving rods. It facilitates the adjusting of the swinging lever and makes possible a simplification for the adjusting of the hydraulic drive.
The invention is illustrated by the construction shown in the drawing.
Patented Dec. 17, 1963 FIG. 1 shows a beam retarder in top view with portions cut away.
FIG. 2 shows the retarder of FIG. 1 in cross section along line IIII.
FIG. 3 shows the portion III of FIG. 1, enlarged, with the brake beam associated therewith.
FIG. 4 shows diagrammatically the drawing of the curve for a roller way corresponding to FIG. 3.
A pair of stirrups 1 is located in each substructure frame 2. The st-irrups support brake beams 4 and 5 on both sides of the two rails 3. Numeral 6 refers to a pack of rubber, 7 an actuating roller supported by a swinging link or lever 8. The swinging links or levers 8 are connected to rods 10 and 10' by intermediate portion 9. Parts 1 to 10 do not form part of the invention.
The actuating rods on the two sides of the line of rails form groups of rods 11 and 12 which correspond symmetrically to each other in all respects and are associated with a common hydraulic cylinder 13 in the middle of the length of the retarder. The two groups of rods 11 and 12 form an adjusting pair of rods together with the cylinder associated with them. Cylinder 13 is fixed on a substructure frame 14 below the rod 10 and has a piston 15 and a piston rod 16 which passes from opposite sides of the cylinder. The piston rod '16 is fixed at its ends to the end walls 17 of a straight line guiding frame 18 which is provided with a pair of hollow bars 19 which are slidably supported on bars 20. The bars 20 are attached to end walls 21 which are rigid with the substructure frame 147 The end walls 17 of the straight line guiding frame 18 are stiffened by side walls 22 which are not shown in FIG. 1 for simplicity. Hinge bolts 23 in the end walls 17 are attached to shackles 24 of the rods 19'.
A two-armed equalizing lever 26 is linked to the hollow bars 19 of the two straight line guiding frames 18 by two bolts 25; the lever 26 links the two groups of rods 11 and 12 below the line of rails and is pivoted at the center with a hinge bolt 27 on the substructure frame 1 4. The substructure frame 14 is formed essentially by a pair of supporting beams 28 linked by a cross piece 29 in the center.
The two groups of rods 11 and 12 have opposite working directions, i.e. the rods are moved in the two directions of arrows 30 and 3% for a positive application of the retarder where the gap a becomes narrower and the brake effect is increased. The swinging levers 8 of the actuating rollers 7 are gradually pivoted towards broken line 31 about pins 39 when the gap a is narrowed. The equalizing lever 26 follows the free running movement of the swinging levers 8 almost without the application of appreciable force, and insures the synchronism, by its mechanical coupling, of the two groups of rods. The synchronism causes the brake gap a, associated with both the brake beams of respective rod groups to be equal when the wheels pass into said gaps and exert forces on the brake to cause an increase in gap a against the resistance of rubber pack 6. Consequently, the retarding force on each of the wheels of every set thereof is nearly the same. The equalizing lever 26 is subjected to high stresses only if there is a disturbance in the operation of one of the two hydraulic cylinders 13 for instance. In such a case however, the equalizing lever 26 prevents the retarder from being operative on only one rail, since the lever systems are constrained to move equal amounts in opposite direction even though only one cylinder 13 is operative.
In FIG. 3 the external brake beam 5 is attached by means of a screw 35 onto a slide chair 36 of which only the vertical leg supporting the roller way 37 can be seen.
Between the brake beam and the leg of the chair is located a regulating wedge 38. The intermediate portion 9 is pivotally movable about pin 39 which supports link 8. The idle position of roller 7 is shown where there is no contact with the roller way 37.
Three gaps a a and a are shown relative to the fixably mounted brake beam 4 in FIG. 3. The braking force is smallest at a and largest at a The corresponding positions of the swinging lever 8 indicated by the respective center lines are shown by lines a a and a radiating from pin 39.
In order to illustrate the curvature of the roller way 37, a swinging lever 8 with hinge point 39 is shown diagrammatically in FIG. 4. Numeral 49 represents the roller 7 reduced to a theoretical point. This simplification allows the following simplified explanation: If the group of rods is displaced in four equal increments s to the right, numeral 40 passes through positions 41, 42, 43 and 44 successively and thereby describes the circular are 45 passing through the above positions. The straight dotted line 46 represents the roller way according to the art. Thus if the actual dimensions of the gap a is 145 mm. in the end position corresponding to a slight retarding effect and 125 mm. in the end position corresponding to maximum retarding, the intermediate dimensions of the gaps corresponding to the position of the link 8 are noted on the left of FIG. 4 and clearly demonstrate that for equal angular movements of the link 8 about pivot pin 39, the gaps produced between the brake beam are not proportional. The ideal line is straight chain line 47, which if followed by theoretical point 40 would result in proportional adjustment of the groups of rods, according to the scale shown on the right of FIG. 4. To obtain the ideal line 47 the dimen sion h is layed off on the line 46 as It. By laying of the distances between the curve described by point 40 and the line 47 onto line 46, a curve 48 is obtained. if the roller way 37 on the slide chair 35 of the brake beam 5 is not formed as a straight line similar to 46, but as a curve similar to 48, the same effect is obtained as if the point 46 were to move along the line 47. Accordingly equal displacements of rod result in equal displacements of the brake beam. Actually, the influence of the diameter of roller 7 has to be taken into account so that the actual rolling way 37 deviates slightly from curve 48.
It is understood that all the actuating points of the retarder are provided with a roller way corresponding to curve 48. For the transition from one side of the retarder to the other, the angle formed by the swinging lever 8 with respect to the transverse plane 31, is changed :from a positive to a negative angle of the same magnitude.
Only the curved rolling way 37 makes fully effective the equalization of rods on the two sides of the retarder, because only the proportional ratio of movement makes sure that both sides of the retarder exert an equal effect on the set of wheels of the passing car.
The rods 10 and 10 are threadably engaged onto members 49 whose external end is provided with a hinge eye for joining to intermediate part 9. The threads on one end of the rod It) or it) and also the pivot connected thereto are left-handed, and at the other end right-handed. With hook keys for insertion in the holes 59 of the rods, these rods can be turned and have the property of a turnbuckle sleeve because the threads are opposite.
With such rods the retarder can be easily adjusted. Moreover, since the wear of the brake beam is most when the retarder is first put into service, it can be adjusted easily by the turnbuckle bars if the swinging levers are preset for slightly excessive wear. The device operates as follows:
When it is desired to effect a braking operation on the wheels of a car passing on the tracks, fluid is regulated in cylinders 13 by an external control means (not shown) to cause movement of pistons 15 in the cylinders. The movement of the pistons results in corresponding movement of the piston rods 16 and movement of guiding frames 18 and 18 on rods 19. The movement of the frames 18 and 18 causes movement of equalizing rod 26 about pivot 27. By virtue of the location of pivot 27 midway between the points of connection of the rod 26 to the frames, the frames undergo exactly equal differential displacements in opposite directions. The movement of the frames 13 and 18 causes resultant movement of the rod systems 11 and 12. Each of the rod systems is constituted by rods 10 and it) which are connected through portions 9 to rollers 7 which is constrained to pivot with links 8 about pivots 39. When the rods 10 and 10' are displaced, the links 8 are pivoted about pivots 39 in a direction towards or away from line 31 dependent upon the direction of displacement of the rod systems. The pivots 39 are each supported on a slidable member which is in contact with rubber pack 6. The rubber pack resists movement of the member supporting pivot 39 when the links 8 are pivoted by the rod systems. When the links 8 pivot about 39, they cause rollers 7 to ride in roller ways 37 and cause movement of brake beams 5. By virtue of the curvature of roller ways 37, the movement of brake beams 5 is substantially proportional to the angle through which links 8 are turned.
When the wheels pass between the brake beams, a force is developed between the wheels and the brake beams to cause braking of the car. The force developed on the brake beams 5 is resisted by the roller packs 6.
1. A brake beam retarder for applying braking forces to the wheels of a vehicle passing on a parallel pair of rails, said retarder comprising: a pair of rod means each parallel to a rail and displaceable in a direction substantially parallel thereto, a pair of beams adjacent opposite sides of each of the rails, means supporting at least one of the beams of each pair for sliding movement transverse of the associated rail, means connecting each of the rod means to a corresponding one of said pair of beams to cause movement of the latter relative to the associated rail in an amount which is proportional to movement of the rod means, hydraulic means coupled to each of the rod means for displacing the same, and an equalizing lever operatively associated with the hydraulic means of each rod means to cause equal movement of each of the rod means in opposite directions.
2. A retarder as claimed in claim 1 wherein the means connecting each of the rod means to a corresponding one of the brake beams, comprises a pivotally supported link connected to the associated rod means, for undergoing pivotal movement in response to movement of the rod means, a roller supported on said link for movement therewith, a roller way supported on said one brake beam and moveable therewith, said roller being in contact with said roller way for causing displacement of the latter and the said one brake beam therewith upon pivotal movement of the link, said roller way being of arcuate shape to provide displacement of the associated one brake beam which is proportional to displacement of said rod means.
3. A retarder as claimed in claim 1 wherein the hydraulic means comprises a cylinder and a piston in the cylinder, said retarder comprising a frame for each of the hydraulic means which is supported for sliding movement substantially parallel to said rails under the action of an associated piston of the hydraulic means, said equalizing lever being connected to each of said frames to cause corresponding movements thereof in opposite directions.
4. A retarder as claimed in claim 3 comprising means connecting each of the rod means to a respective one of the frames whereby the rods are displaced in accordance with movement of the frames.
5. A retarder as claimed in claim 1 wherein the rod means comprises a plurality of interconnected rods and an intermediate portion connected to the links associated with each of said one brake beams, and connected to rods of the rod means, each intermediate port-ion including ends of opposite threading in threaded engagement with associated rods thereby enabling relative adjustment of the latter.
6. In a brake beam retarder adapted for applying braking forces to the wheels of a vehicle adapted for passing on a parallel pair of rails, the retarder being of the type having a brake beam associated with each rail and supported for movement in a direction transverse thereto, a rod system for each rail associated with said brake beam for controlling the position thereof relative to said rail and a hydraulic device for each rod system for moving the same to in turn cause movement of the respective brake beams relative to the rail associated therewith, an improvement for the retarder comprising: an equalizing lever, means pivotally supporting the equalizing lever midway thereof, means connecting each of the hydraulic devices to the equalizing lever at locations on the latter substantially equidistant from the pivotal support of the 6 lever, means connecting each of the rod systems to the last said means to cause synchronized, equal movement of the rod systems in opposite direction under the action of said equalizing lever and the hydraulic device, and
means connecting each of the rod systems with a respective brake beam to cause movement of the latter relative to the associated rail in an amount which is proportional to movement of the rod systems.
References Cited in the file of this patent UNITED STATES PATENTS 1,280,873 Schuh Oct. 8, 1918 1,459,574 Cover et al June 19, 1923 1,629,286 McCallum May 17, 1927 1,871,929 Varble et al. Aug. 16, 1932 1,907,037 Bickley May 2, 1933 2,679,809 Beltman June 1, 1954 2,943,709 Schode July 5, 1960 FOREIGN PATENTS 733,207 Great Brita-in July 6, 1955 947,172 Germany Aug. 9, 1956