US814910A

US814910A - Electromagnetic brake.

Info

Publication number: US814910A
Application number: US21940104A
Authority: US
Inventors: Erwin Kramer
Original assignee: Individual
Current assignee: Individual
Priority date: 1904-08-03
Filing date: 1904-08-03
Publication date: 1906-03-13
Anticipated expiration: 1923-03-13

Description

' 'PATENTED MAR. 13, 190g E. KRAMER. Y

ELECTROMAGNETIC BRAKE.

APPLICATION FILED AUG. 3. 190 .1.

rll llllllllllll ll||| 7 brake eonsisting'o the electr'omagn j terrain-STATE PATE T FER EEWIN- KRAMER, or BERLIN, GERMANY.-

' eL'aorfiomneur-zrlc BRA -n To all whom) it may concern.-

ject oil-the King of Prussia, German Emperor, residing at No. 9 Paul street, Berlin,

Germany, have invented certain new and useful lmorovernents iii-Electromagnetic Brakes,

oi which the following isfa spec fication. v, i mvention relates'to brakes, principall for electrical street-railways, provided wit an electromagnet, which actuates a'system' or levers and presses thebralie-blocks' to the. hnwhielsll invention is to produce a an 'electromagnet of such a for every, intensity of'curet is -Theobje ct of m construction hat rent "the armature of theelect'roma moved to e definite position, and of t e con-- 7 nection of such an electromagnet with an aparatusdriven by the wheel-axle which regueltes the intensity of the current, .ener 'zmg etin accordance wit the speed of rotat on of the wheels. The said magnetic effector attraction ,is attained,

I i owing to the fact that the cross-section of the nth of he lines of force between the iron ody of the solenoid and thecore is decreased by the (lee er drawing in of the latter, where by the too, 'gh increase of the me: eticforce,

a and the consequent drawing in y starts of he core,is obviated. As, therefore, the'force' with which the brakes are attracted depends upon the-intensity of the current, so above a certain limit the application of the brake 'blocks is proportionate to the velocity of rotation ofthe wheels. I attain these objects by the mechanism illustrat drawing, in whic the operatin' parts are shown in full lines and some deta' s v of the carriage indotted llIlGS.

' n 4 I u b I of a coil of wire 1,1nclosed1n an lrolrcasing 2.

The fore extrerrnty The solenoid attractingthe brakesconsists of the casing is partlall closed by an annular iron shoe 3, which 1s fixed thereon by screws or iamade of such a le core is the like. In the cavity of the coil '1 and' of the shoe 3 an lron core 4 is displaceableaidallllpand the core 4 h '0' y that the outer of the same is ina eeper position then the mneeeiid of theshoe, when the core is drawn fintdthe coil whereby the cross-section of the Ipathhi the lines oiforce from the shoe to the reduced the moredeeply the core is die" n in, '--By this means the too speedy increase of the magnetic force is obviated, so that the core is not drawn inward deeper than ole-frame,

, sented,'others mightloe ernp tures of which would assume adefiniteposiin theaccom H Bpeoifiodtion ofLetters'Patent-f iPatnted Marchll3, v Application filed AugustS, 1904., atrium. 219.401."

in .-current for the time being. he core t is provided longitudinal bores and is guided by means of these on bolts 5, the ends of which are fas- 6o tened in the rear wall of the iron casing 2 and ter is ixed'upon the shoe 3 for mounting the electromagnet on the .vehi- Instead of the electroxne yed, the armation for each current intensity.

Upon the outer end of the core is fined a 7 rod 7, which,by means of alink 8 and lever 9 acts upon the usual" brake-rods 1O 11 .12,

which carry the brake-blocks 1'3 and which are taken off by released.

The braking-'electromagnet is preferably energized directly by the electromotors of the vehicle, which by the intermediaryx-of tlie starting-switch are connected W1 e elec-. troma tion 9 act as current-generators. thatfwithsuchan arrangement the current intensity produced by the motors of the vependent on the velocityof rotation 85 of they wheels. I As, however, as alreadyex plained, the position of the core corresponds hicle is with the current intensity, the pressure of the brake-blocks upon the wheels-is dependent 9 The brake acts 1n the following manner: When the driver desires to apply. the brake,

upon the rotative s eed of these latter. i

'th a number, of

springs 14; when the'lirake is r orresponds to the intensity of the'mflgnletlizf I 'in a ca or bridge 6, respective ,whlchlatyes '15 serve .I I 5. %net here repre- O et, if necessary," with the interposi- '80' resistance in such a mannerthat they T It is'well-known he. switches the electromotors onto the brake:

electro'ma ets.'- The-motors then generate current, t e strength'of which corresponds '5 .tp the-velocity of rotation of the wheels, so

that the core 4 is drawn into the corresponding (position in the coil an phe with a certain force. the decreased velocity of When, owing topressure mlmshed tirely without shock. The brakes are like liable to slide, as in this case also the rotative velocity of the Wheels, and conseo'lently the current intensity, decreases. It is thereforeimpossible for" the Wheels to be locked; If, x

the. brake sipthe car and of the 106 wheels the intensity of the current fells', the

of the brake isalso gradually ditill the vehicle comes to rest enon the other hand, the vehicle should start rolling u onan incline or owing to other causes, -t e current intensity rises and the brakes will be applied morefirrnly.

Instead of connecting the motor of the vehicle directl with the 'brake-electroma gnet, a centrifu a governor might becoupled with the whee -shaft and switch in current of greater intensity forthe brake electromagnet when the s eed of rotation of the wheels was high and ower intensities when the speed. was lower. In this case, however, a source of current'which is constant to some extent,

atleast, must be used. i

The brake may be varied in different ways without departing from the principle of my invention. I therefore do not wish to be limited to the construction illustrated in the drawing; but

What I claim as m invention and desire to secure by Letters atent, is-- 1. In an electromagnetic brake for vehicles, the combination withan electromagnet,

having a'coil, an ironcasing inclosin the coil,

in conformity with the rotative speed of the wheels; and circuit connections between the electromagnet and the current-generator, substantially as described. i

2. An electromagnet for vehicle-brakes, 0 having a coil, an iron casing inclosin the coil, an iron shoe closing the open end 0 thejcasing, a central opening in the shoecoinciding with thehole of the coil, a core adapted to move axially in the said cavity of the coil and 4 5 shoe, the core being of such a form that the *eross-section of the path of the lines of force from the shoe to the core its-reduced, when the core is drawn into the coil, substantiallyas described. 5 3. An electromagnet for 'vehicle brakes, having a coil, an iron casinginclosing the coil, an annular iron shoe partially'clesing the open end of the casing, a coreadapted to -move axially in the cavity of the coil and 55 shoe, the corebeing of such a form that the cross-section of the path of the lines of-force from the shoe to the core is reduced, when the core is drawn into the coil, which-electro-' Ina net is energized bythe vehicle-motor, 6o wit whichit is short-circuited; in combination with a system of brake-levers, substantially as described. A In testimony whereof I have signed my.

name to this specification inpr'esence of two 65 subscribing witnesses.

ERWIN KRAMER. Witnesses Germs-Bonus, CARL APMAN.