US1779776A - Braking mechanism for railway vehicles - Google Patents

Description

Oct. 28, 1930. A. MAsloN I BRIAKING MECHANISM FOR RAILWAY VEHICLES Filed Aug. 10, 1928 Patented Oct. 28, 1930 I UNITED STATES PATENT OFFICE Application led August 10, 1928, Serial No.

This invention relates to brakes for railway vehicles of the type in whichlthe braking shoes are adapted to engage the side faces of braking wheels or drums instead of en- 6 gaging the convex peripheral surface of the vehicle wheels as is usually the case. This arrangement is very eflicient as it affords the possibility of lacting on large braking surfaces in immediate proximity of the axle.

However the brakes of this type proposed heretofore require heavy and complicated riggings, and they do not provide for a uniform action of the brake shoes on both sides of the wheel or drum under all operatingl conditions. The object of the present invention is to obviate these inconveniences.

In accordance with lthis invention, the brake shoes acting on the side faces of the braking drum or wheel are located above the axle carrying said rdrum og wheel and are suspended from the vehicle frame by means of pivoted arms or members having their longitudinal axis in the vertical plane extending centrally of the axle. Said arms are actuated by bell crank levers the two arms of which have different lengths so as to amplify as much as possible the pressure transmitted to the brake shoes. The bell crank levers have no operating connection with the shoe carrying arms but they push directly thereon with their short arms, while their long arms are connected by means of rods and a compensating lever with a driving member, for example the piston of a power cylinder.

An important advantage of this construction is that the whole brake gear can be arranged above the axles and as near as possible to the vehicle frame, whereby the bendf ing stresses in its supports are considerably reduced. All the parts for operating the shoe carrying arms can be arranged in the same plane, which is very favourableto the reduction of stresses and provides a very simple and compact structure. Another advantage is that incurves the brake shoes and drum willhave the necessary freedom of movement to secure an operative engagement of the braking surfaces even when the braking shoes must move through different vWard the drum 3 298,728, andvin Belgium September 9, 1927.

distances in order to get into braking engagement with b oth sides of the drum.

lIn the accompanying drawing I have diagrammatically illustrated, by way of example, a brake with a friction drum embody- 5G ing my present invention.

Fig. 1 is an elevation at right angles to the vehicle axle in section on line I-I of F ig. 2.

2 is an elevation parallel tothe axle. 60

Flg. 3 is a horizontal section on line III-III of Fig. 2. A

In the drawing 1 is the vehicle frame and 2 an axle on which is secured, at an intermediate point thereof, a drum 3 with side fric- 65 tion surfaces. These side surfaces are adapted to be respectively engaged by two brake shoes 4 located above the axle and carried each by an arm 5 depending from the vehicle frame 1 and having its longitudinal 7 axis in the vertical plane extending cent-rally of the axle 2. The arms 5 are pivoted to the frame at 6 and the shoes 4 are mounted thereon by means of pin and slot connections 7, 8. Springs 9 are provided between the shoes 75 4 and links 5 in order to keep said shoes parallel to the friction surfaces ofthe drum when they are disengaged therefrom.

The shoe carryin arms 5 are pushed toy means of bell crank levers 10 pivoted on vertical pins 11 secured to the vehicle frame 1. The two arms of the levers 10 are of different lengths, and their short arms bear directly against the arms 5, which are preferably provided with yoke 8 5 shaped members 12 in which these arms are loosely engaged in order to control the returning movement of the shoes to their inoperative positions. To the long arms of the levers 10 are pivoted at 13, rods 14 which are 90 connected by means of a compensating lever` 15 to the rod 16 of the piston 17 of an air pressure cylinder 18.

When the piston 17 is actuated the two levers 10 turning on their pivots 11 bring 95 the shoes 4 independently of each other into engagement with the sides of the drum 3, whereupon both shoes are pressed against the drum simultaneously and with equalv force, even ifthe axle has moved transversely of the vehicle frame, as happens' in curves of small radius. This .is due to the action of the compensating lever 15 and to the fact that the levers 10, not being permanently connected with the arms 5, are free to move throughsuch angle as is necessary to bring the shoes into engagement with the drum.

Upon release ofthe pressure the arms fall back and are moved out of reach of the drum lthrough the members 12, it being understood however that there should be sufcient clearance between these members and the levers to allow to said levers and to. the arms complete freedom of oscillation abouttheir V'respective pivots 11 and 6 throughoutv the rangev of their operative movements.

As shown in thedra ing the levers 10 and the partei contrgllin vtheir operation are .o preferably. mounted 41n the same plane, so

that nfcoiiparison with other brake struc- 'turues'thestresses to which they are subjected are reduced-,'their construction may be made lighter, and they' can be rmly mounted on g5 their supports .without fear of undue wear. It will." also b e 'ap reciated that tlie entire operatin gear can be placed' very close to the being adapted to engage the side faces of said drum above said axle, bell crank levers for actuating said vertical arms, a power cylinder secured to said frame, a piston in said cylinder, and lever and rod connections between said piston and said'bell crank levers, said piston, bell crank levers and connections being located in a horizontal plane above said axle and in close proximity to said frame.

In testimony whereof I aix my signature.

ALFRED MASION.

vehicle ame, thus taking up small space,

and redu'einglthe length of the pivots 11suba0 jected to bending stresses.

The construction shown can `also be used for brakin' the wheels 19, but the 'nsejof a braking as 3 usually is preferable'. as

it does not` uire thatthe distance between v se the axle and t e frame be increased.

. I claim:

, 1. In a braking mechanism for railway ve-- hicles, the combination of va shaft, a ,disc

a pair of bra the side faces of said braking member above said shaft, pivoted arms carrying said shoes and adapted to swing in` a Vvertical plane 'passing through said shaft, and means for actuatlng said arms comprising levers and rods mounted in ahorizontal plane above said shaft.

. 2. In a braking mechanism for railway vehicles, the combination with a vehicle frame and a vehicle axle, of a disc-shaped braking member secured .to said axle, a pair of brak-l ing shoes adapted to enga e the side faces of said braking member a ove said axle, a pair of arms each carrying-one of said shoes, said arms being pivoted to said frame'for motion in a vertical plane, and means for moving` said arms towards said braking m said means being located in ahorizonta plane above .said axle. f

shaped brakinlglmember secured on said shaft, 'ng shoes adapted to engage U0 '3. In a braking mechanism for railwayve- I lhicles, the combination-with a vehicle. frame and a vehicle. axle, ofa braking drum ono said I. axle,`a pair' of vertical arms pivoted to said t frame, braking shoes horizontally pniloted on the free endsof said arms, said bra g shoes

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