US3927739A

US3927739A - Device for mounting rail-brake magnets

Info

Publication number: US3927739A
Application number: US531189A
Authority: US
Inventors: Ernst Katzer; Pierre Baronnet
Original assignee: Knorr Bremse GmbH
Current assignee: Knorr Bremse AG
Priority date: 1973-12-08
Filing date: 1974-12-09
Publication date: 1975-12-23
Anticipated expiration: 1992-12-23
Also published as: DE2361312A1; IT1024323B

Abstract

A pair of rail-brake magnets mounted from a railway truck are actuated by a fluid pressure actuation device which comprises a double-action pressure bellows acting in opposite directions against first lever arms which are rigidly attached to a pair of parallel torsion rods which are pivotally mounted and extend transversely to the rails. Two second lever arms are rigidly attached to each torsion bar and extend at an angle to the first lever arms such that the free ends of the second lever arms on a torsion bar engage support bearings upstanding near the ends of the brake magnets.

Description

United States Patent [1 1 Katzer et al.

[ 1 Dec. 23, 1975 1 1 DEVICE FOR MOUNTING RAIL-BRAKE MAGNETS [75] Inventors: Ernst Katzer; Pierre Baronnet, both of Munich, Germany 1 [73] Assignee: Knorr-Bremse GmbII, Munich,

Germany 22 Filed: Dec. 9, 1974 21 Appl. No.: 531,189

30 Foreign Application Priority Data Dec. 8, 1973 Germany 2361312 [52] US. Cl 188/206 R; 105/77; 188/165; 1 188/216 [51] Int. Cl. 1 16]) 65/34 [58] Field Of Search; 188/165, 205 R, 206 R,

[56] References Cited UNITED STATES PATENTS 1,782,192 11/1930 Brownyer 188/165 2,270,425 1/1942 Farmer 105/77 2,975,872 3/1961 Lacy 188/216 R FOREIGN PATENTS OR APPLICATIONS 583,766 8/1933 Germany 188/165 846,525 9/1939 France.....'... 188/165 7/1970 Germany 188/165 Primary Examifir-Trygve M. Blix Assistant Examiner-Edward R. Kazenske Attorney, Agent or Firm-Edmund M. Jaskiewicz [57] 1 ABSTRACT A pair of rail-brake magnets mounted from a railway truck are actuated by a fluid pressure actuation device which comprises a double-action pressure bellows acting in opposite directions against first lever arms which are rigidly attached to a pair of parallel torsion rods which are, pivotally mounted and extend transversely to the rails. Two second lever arms are rigidly attached to each torsion bar and extend at an angle to the first lever arms such that the free ends of the second lever arms on a torsion bar engage support bearings upstanding near the ends of the brake magnets.

6 Claims, 3 Drawing Figures US. Patent Dec. 23, 1975 Sheet 1 of3 3,927,739

US. Patent Dec. 23, 1975 Sheet 2 of3 3,927,739

U.S. Patent Dec. 23, 1975 Sheet 3 of 3 3,927,739

DEVICE FOR MOUNTING RAIL-BRAKE MAGNETS The present invention relates to the mounting of railbrake magnets from a railway truck, more particularly, to the mechanism and linkage for actuating the rail-brake magnets between an upper rest position and a lower ready brake position.

Rail-brake magnets have been mounted upon railway trucks by a suitable linkage so as to be positioned in pairs above the rails. A pressure medium control actuation device acted upon the linkage for the purpose of moving the rail-brake magnets from an upper rest position into a lower ready brake position in which latter position brake magnets were maintained by spring force. In the ready brake position the brake magnets are pulled automatically against the spring force into the braking position on the upper surfaces of the rails when the magnets are electrically energized.

Each rail-brake magnet has been commonly actuated by at least one but usually two pneumatically operated actuation cylinders positioned above the magnet. In preparation for a braking operation, the cylinders move the brake magnets into a ready brake position wherein the magnets are positioned closely above the upper surface of the rail. It is therefore necessary that for every pair of associated brake magnets there must be provided two or four cylinder units. The cylinder units necessarily require a complex control and operating system which is arranged along the outer portion of the railway vehicle above the brake magnets. In view of the limited space available in this portion of the railway vehicle the arrangement of the cylinder control system is very crowded and complex and is difficult to install.

It has been proposed to employ an auxiliary magnet or a plurality of such magnets on the side of the vehicle so as to control the movement of the brake magnets through intermediate linkages. However, this arrangement had a similar disadvantage in that a plurality of auxiliary magnets were required for every pair of brake magnets and it was necessary to arrange these auxiliary magnets even more accurately in the very limited space available at the side of the vehicle in the vicinity of the truck.

A further disadvantage of known suspension arrangements for rail-brake magnets is that the magnets are rarely maintained in parallel with the upper surface of the rail since the magnets tend to pivot with the suspension linkage about a point or are retained by means of two actuation units that can be adjusted with respect to each other only with great difficulty. As a result of the rather frequent non-parallel positioning of the magnets, the lower surfaces of the brake magnets are rapidly worn off particularly at their ends. This wear significantly reduces the available braking surfaces.

A further disadvantage of known devices for mounting rail-brake units is that such units must be installed during the construction of the vehicle. A vehicle that is not originally equipped with magnetic rail-brakes can be equipped with such rail-brakes at a subsequent time only at a very great cost and by means of a difficult rebuilding and installation procedure.

It is therefore the principal object of the present invention to provide a novel and improved device for the mounting from a railway truck of a pair of railbrake units.

It is another object of the present invention to provide a device for the mounting of such rail-brake units which is compact in arrangement and can be readily installed on an existing vehicle without modifying substantially the original structure of the vehicle.

It is a further object of the present invention to provide such a device for mounting rail-brake units wherein the actuation device for the rail-brakes occupies a small space and wherein there is some choice in selecting the location of the actuation device.

According to one aspect of the present invention a device for mounting from a railway truck a pair of rail-brake magnets above the rails may comprise a pressure medium actuated bellows means which acts in opposite directions against a pair of first lever arms each of which is attached rigidly to one of a pair of parallel pivotable torsion bars extending transversely to the rails. Two pairs of second lever arms are provided and each pair is attached rigidly to torsion bars on either side of the bellows means such that the second lever arms extend at an angle to the first lever arm. Each of the second lever arms has a free end with one of said rail-brake magnets being supported at the free ends of each pair of the second lever arms. The bellows means moves the rail-brake magnets between a lower ready brake position and an upper rest position and includes spring means for retaining the rail-brake magnets in the ready brake position.

The bellows means may comprise a spring unit which acts against oppositely directed bolts extending from a housing of the spring unit with the bolts being provided with abutment means to engage portions of the housing to limit the movement of the bolts.

Other objects and advantages of the invention will be apparent upon references to the accompanying description when taken in conjunction with the following drawings, which are exemplary, wherein;

FIG. 1 is a side elevational view of a rail-brake magnet mounting device according to the present invention with portions thereof being in section;

FIG. 2 is a top plan view of the device as shown in FIG. 1; and

FIG. 3 is a perspective view of the rail-brake mounting device according to the present invention.

Proceeding next to the drawings wherein like reference symbols indicate the same parts throughout the various views a specific embodiment of the present invention will next be described in detail.

In FIGS. 1 and 2 there is indicated at 9 a truck or frame of a railway vehicle having conventional wheels shown at 10. The truck or frame is provided with a transverse beam 11 to which are attached a pair of bracket arms 12 which are curved downwardly toward the rails 13 as shown in FIG. 1. The lower ends of the bracket arms 12 are substantially perpendicular to the rails as seen at 14 and have attached on the inner sides thereof transverse side bars 15. On the ends of each side bar 15 there are mounted inwardly directed pivot pins 16 upon which torsion bars 17 are slid. The torsion bar 17 may comprise tubular elements and extend parallel to each other between the side bars 15 and are pivotable upon the pivot pins 16.

A pneumatically operated pressure bellows 18 is mounted at any convenient position between the brackets 12 and above and between the torsion bars 17. The actual location of the bellows 18 is thus not limited to any precise area but may be located anywhere within the space thus defined. The bellows 18 actually comprises a pair of bellows which are fastened together upon a downwardly extendingcentral plate 22 which is inserted into two slotted plates 21 extending upwardly from a spacer or separator element embracing both torsion bars 17 by means of curved portionsl9. The bellows 18 is thus attached in any suitable manner to the spacer elements 20 as described above.

The pressure bellows 18 engages the upper ends of two guide rods 23 whose lower ends are rigidly attached such as by welding to torsion bars 15.

Near the ends of each torsion bar 17 are welded a pair of angular lever arms 24 which extend one behind the other in the form of shears and over the opposing torsion bar in the manner as shown in FIGS. 1 and 3. The lever arms 24 are curved to engage support bearings 25 on the ends of a rail-brake magnet 26. The support bearings 25 are in the shape of a hook the opening of which extends slightly downwardly and receives pivot pins 28 on the free ends of the lever arms 24. Each lever arm 24 is thus connected between its torsion bar 17 to the support bearing 25 which is furthest away from that torsion bar. By means of the bearing surfaces 27 on the bearing support 25 a rail-brake magnet 26 is thus supported continuously in parallel with the upper surface of rail 13 on the levers 24. There is a sufficiently large play or clearance s between the hook-shaped support bearings 25 and the bearing pins 28 on the ends of the lever arms 24.

U-shaped recessed vertical guides 30 are mounted on the upper surface of each rail-brake magnet 26. The guides 30 are attached on the bracket arms 12 below side bars 15 and embrace corresponding vertical guides 32 in such a manner that the rail-brake magnets 26 are capable of guided vertical movement. A sliding coating or plating may be disposed between the inner sides of the vertical guides 30 on magnets 26 and the outer sides of vertical guides 32 on brackets 12. This coating is not shown but is known in the art and reduces the wear on the vertical guides. I

In order to avoid independent movement of the brake magnets 26 transversely to the longitudinal direction of the vehicle, a pair of brake magnets are interconnected and thus stabilized by means of a tie rod 34 as may be seen in FIG. 3.

The pressure bellows 18 comprises two annular bellows elements 41 that are mounted to its central plate 22 and attached to a pair of bell-shaped pistons 42 to form a sealed cylindrical space which can be subjected to the action of pressure and is connected to a pressure medium pipe 43. The cylindrical space is vented through a switching valve which is not shown in the drawings but is known in the art and is preferably located near a source of pressure medium.

Passing through each of the pistons 42 are bolts 44 having ball ends 45 which are received within ball cups 23 on the lever arms 23. The length of the ball end 45 can be adjusted by means of the nuts 46. Mounted on the central plate 22 is a compression spring unit 48 for movement of the lever rods 23 and is provided with structure thereon for limiting the stroke of these arms in a manner to be presently described.

The spring unit or stroke limiting unit comprises a pair of cylindrical housing components 48' having flanges which are secured on both sides to the central plate 22. The rear or inner ends of bolts 44 are provided with abutment heads 49 which engage inwardly flanged portions on the housings 48'. The housings 48' contain springs 51 such that one end of each spring rests against the central plate 22 and the other end rests against an outer abutment plate 51'. The outer movement of the plates 51' is limited by a shoulder portion within the housings 48 and thus define a free stroke A of the pistons 42 with bolts 44 and the arms 23 then engage the bolts. The distance of the free stroke is followed by a cushion stroke B which is determined by the adjustment of the spring sets 51 such that the abutment heads 49 of bolts 44 are pressed against abutment plates 51 which can be displaced inwardly by stroke B against the force of the springs 51. It is therefore apparent that the free stroke A and the cushion stroke B are readily adjustable as to length.

The adjustment of the stroke enables resetting of the position of the rail-brake magnets 26 to the desired distance from the upper surface of the rails 13 even when the magnets 26 and/or the wheels 10 are worn.

In FIG. 3, it is apparent that the location of the annular bellows 18 is selected arbitrarily in the direction of torsion bars 17 and this location can be readily adapted to this available space existing in the truck or substructures of railway vehicles.

The brake magnets 26 are shown in their rest positions and in this position the annular bellows 18 is vented through a suitable switching valve which is not shown. As a result, the weight of the brake magnets 26 causes them to descend until abutment heads 49 on the bolts 44 engage the abutment plates 51'. The lower surfaces of the rail-brake magnets 26 are then located approximately 10 mm. above the upper surface of rail 13 in the ready brake position indicated at B.

When the rail-brake magnets 26 are energized by the passage of electrical current therethrough, they will be attracted by the rails. This downward movement of the rail-brake magnets 26 will cause the bolts 44 to compress the springs 51. The spring force of the springs 51 .is less than the magnetic force between the brake magnet 26 and rail 13.

When a brake magnet 26 is in contact with rail 13 a strong surface friction will be produced between the lower face of the brake magnet and the upper surface of the rail which friction force is further amplified through the magnetic forces acting between these two elements. The brake forces thus occurring in the longitudinal direction of the rail because of these friction forces could not be absorbed by the

levers

24 and 23. As a result, these brake forces are introduced through vertical guides 30 and 32 directly into bracket arms 12 and through these bracket arms into the truck or frame of the vehicle.

When the braking operation has been completed, the brake magnets 26 will again be lifted into their positions about 10 millimeters above the upper edge of the rail by springs 51 that are again relaxed. The brake magnets will remain in this position until compressed air is introduced into the bellows 18 through supply line 43. Only then will the brake magnets be lifted into their rest position by this application of compressed air through pistons 42, and interaction of bolts 44, levers 23, torsion bars 17, levers 24 and bearings 25. The clearance between levers 24 or pivot pins 28 thereon and bearings 25 in the longitudinal direction of the vehicle is greater than the clearance between vertical guides 30 and 32 so as to prevent any possibility of braking forces acting upon the rods or linkage during the braking operation.

In the described operation of controlling the movement.of the brake magnets it is preferable that the brake magnets drop automatically into the ready brake position should the supply of compressed air be damaged or fail for any reason.

Except for brake magnets 26, the entire mounting structure can be flanged onto bracket arms 12 and thus may be mounted on a vehicle, subsequent to the actual construction of the vehicle, without the necessity of making additional modifications on the railway vehicle. When the magnetic brake structure is thus mounted after the vehicle has been constructed it is preferable on the one hand that the actuated lever 24 be located at a low level and on the other hand the actuation elements themselves consisting of the levers 23 and'thc annular bellows be located above the torsion bars in any desired location in accordance with conditions as described above with respect to the underframe or substructure of the vehicle.

It is therefore apparent that the rail-brake mounting device of the present invention embodies several significant advantages with respect to prior art structures. One such advantage is that only one actuating cylinder is required in place of the four actuating cylinders commonly employed in such rail-brake structures. The mounting device can be located between the axles of a truck and as such can be mounted by means of a simple suspension by arms attached directly to the frame. When the compressed air supply should fail for any reason the rail-brake magnets will automatically descend into their ready brake positions. According to the present invention, the rail-brake magnets are lifted by the application of compressed air. The mounting device of the present invention also provides for maintaining the rail-brake magnets in a parallel relationship to the upper surfaces of the rails.

It will be understood that this invention is susceptible to modification in order to adapt it to differentusages and conditions, and accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of appended claims.

What is claimed is:

1. In a device for mounting from a railway truck a pair of rail-brake magnets above the wheels, the combination of a pair of pressure medium actuated bellows means for acting in opposite directions, a pair of first lever arms acted upon by said bellows means, a pair of parallel pivotable torsion bars extending transversely of the rails and a said first lever arm attached rigidly to each of said bars, two pairs of second lever arms and each pair attached rigidly to said torsion bars on either side of said bellows means at an angle to said first lever arms and each second lever arm having a free end, one of said rail magnets being supported at the free ends of each pair of said second lever arms, said bellows means moving the brake magnets between a lower ready brake position and an upper rest position and including spring means to retain said brake magnets in the ready brake position.

2. In a device as claimed in claim 1 and each of said rail-brake magnets having support bearings thereon, each of said second lever arms attached to one of said torsion bars and extending over the other of said torsion bars and the free ends thereof engaging said support bearings adjacent to the other of said torsion bars.

3. In a device as claimed in claim 1 wherein said bellows means comprises a centrally mounted compression spring unit, a pair of oppositely directed bolts extending from said unit and having abutment means thereon engageable with portions of said unit in the ready brake position of the brake magnets.

4. In a device as claimed in claim 3 and said spring unit comprises a cylindrical housing and having means for guiding the stroke of said bolts, a frame for mounting said pair of bellows, and said cylindrical housing being secured to said frame.

5. In a device as claimed in claim 3 and means on said bolts for adjusting the length thereof so that the uncushioned stroke of the brake magnets from their rest position into the ready brake position can be adjusted.

6. In a device as claimed in claim 3 and the cushioned stroke of the brake magnets from their ready brake position into their braking position is adjustable dependent upon the spring unit which has been selected.

Claims

1. In a device for mounting from a railway truck a pair of railbrake magnets above the wheels, the combination of a pair of pressure medium actuated bellows means for acting in opposite directions, a pair of first lever arms acted upon by said bellows means, a pair of parallel pivotable torsion bars extending transversely of the rails and a said first lever arm attached rigidly to each of said bars, two pairs of second lever arms and each pair attached rigidly to said torsion bars on either side of said bellows means at an angle to said first lever arms and each second lever arm having a free end, one of said rail magnets being supported at the free ends of each pair of said second lever arms, said bellows means moving the brake magnets between a lower ready brake position and an upper rest position and including spring means to retain said brake magnets in the ready brake position.