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Publication numberUS1413667 A
Publication typeGrant
Publication dateApr 25, 1922
Filing dateJan 8, 1921
Publication numberUS 1413667 A, US 1413667A, US-A-1413667, US1413667 A, US1413667A
InventorsK. L. Lehmann
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
A copartnership consisting oe christ
US 1413667 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)



APPLlcATIoN mio 1AN.8,192|.

1,413,667. Patented Apr.25, 1922.




1,41 3 ,667. Patented Apr. 25, 1922.




APPLICATION man JAN. 8. |921.

Patented Apr. 25,' 1922u 4 lSHEETS--SMEET 3L Ifl LJLJLJLJLJULJLJLJ VE /f z L. .Le/mam EEEEE K. L. LEHMANN.




Patented Apr. 25, 1922.


VE? LII!l (aff.




Patented Apr. 25, 1922.

Application filed January 8, 1921. Serial No. 435,788.

To all whomz't may concern:

Be it known that I, KARL L. LEHMANN, a citizen of Norway, and a resident ofthe city of Chicago, in the county of Cool: and State of Illinois, have invented certain new and useful Improvements in a Railway Signaling Device; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying'drawings, and to the numerals of reference marlred thereon, which form a part of this specification.

Numerous attempts have been made to devise a system of controlling a signal in a railway cab by means of arrangements along the roadway. `home of these devices malte use, of the mechanical attraction between an electro-magnet on the vehicle and a bar of iron on the road bed. These possess the disadvantage that the mass to be moved by the comparatively small force exerted through a practical air gap is large and consequently the control of the signal isslowly exercised, and' the vibrations caused by curves and grades may prevent their acting or cause them to act in the wrong place.

It is an object of this invention to provide a device of this class in which this difiiculty shall be avoided.

It is a further object of this invention to provide a train carried signal device which shall be controlled bymeans of bars of iron along the road bed but in which the electromagnet on the vehicle shall remain stationary relative to the vehicle.

It is a further object of this invention to provide a signaling system in which the signal bars used on the road bed may be shorter than has been necessary in the devices heretofore employed. Y

It is a further object 'of this invention to provide a signaling 'system which may be operatedby the use of a smaller amount of energy than has been necessary heretofore and whichshall thereby be more economical and reliable. I f

It is a further object of this invention to provide a signaling system in which the moving parts shall be few and light and situated in well protected places.

It isa further object of this invention to provide a magnet with a pole having a moving poleshoe.

It is a further object of this invention to provide a circuit controller on the vehicle adapted to be operated by the movement of a moving portion of the poleshoe of a magnet under the influence of a bar of iron upon thero'ad bed.

Other" and further important objects of thisV invention will be apparent from the disclosures in the specification and drawings. y

The invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

0n the drawings:

Figure 4l is a diagrammatic view of a railway locomotive and a'portion of the road bed with this signalingequipment thereon.

Figure 2 is a viewof a portion Aof the road bed.

Figure 3 is a view of the circuit closing device illustrated on the locomotive in Figure l.

Figure 4 is an end elevation, and

Figure 5 isa section `of'a modification of the circuitclosing device.

Figure G is a side elevation and Figure 7 a plan partly in'section of a portion of another modiiication of the circuit closing device. Y

Figure 8 'is an elevation and Figure 9 a plan partly in section of a portion of another modiiication of the'circuit closing device.

Figure 10 is a diagrammatic elevation of still another n'iodification of the circuit closing device.

Figure 1l is a diagrammatic view of still another modification showing also a section of a portion of the road bed.

As shown on the drawings:

, `The reference numeral l indicates the vehicle which runs upon the rails 2. `At intervals along` the Itrack there are placed bars of iron 3. These may be either between the rails or outside thereof as the designer may propose. They must, however, be so placed that thepart Ll carried on the locomotive will pass in close proximity` to these bars. rlhe part a may be located atvany convenient point on the locomotive. If it is between the wheels the bars 3 must be between the tracks. lf the part d is outside of the wheels the bars 3 must be outside of the tracks. A protective plow and cover against snow l is 'preferably provided. The part t is of iron or steel and is magnetized by a coil 6 `led trom the battery 5.

r1`he core oit the part 4 may be a permanent magnet or the part may be a permanent magnet reinforced by current from a battery. Again it may be an electromagnet or an electromagnet in which the current 1s increased at certain times during its motion.

The particular form of this part 4 illus` trated in Figure 1 is shown in further detail in Figure 3. '1n this figure the iron core 4 is shown as U-shaped with its flattened tapering ends turned at nearly right angles to the arms ot the U as indicated at and 71, preferably slanting a little downwardly to` wards the ends. These ends are to come into a fairly close proximity to the bars 3 when the vehicle passes over that portion of the track near the bar. Thecoil 6 is wound upon the middle portion 7 of the core 4. Upon the flat end portion 71 is a rounded housing 8 to provide a hollow space 9 in whichthere is movably mounted a piece of sott iron 10, with a contact index 10 and turning around hinges 11. Mounted in the side of the space is a block of insulation 12 which contains the contact points ot a circuit closer. This contact may be a sliding one as shown or otherwise. A spring 13 normally serves to keep the part 10 out ot' engagement with these points and the whole space is covered with'a cover plate 14 ot brass or other non-magnetic material.

' In this form of the device, the main mag` netic circuit is through the core 4, Vthe pole piece 71, the air to the member on the track, through this member and the pole piece 70 back to the core 4. There is, however, a branch magnetic circuit which leavesv the main magnetic circuit at the hinges 11 and goes through the sott iron piece 10. From there it goes through the air to return to the main magnetic circuit. When the sott iron piece 10 is moved under the magnetic attraetion as explained below, the branch magnetic circuit approaches the main magnetic cir` cuit.

The magnetization ot the core 4 set up by the current in the coil 6 is not sufficient to overcome the effect of the spring 13. Conequently the spring keeps the member 10 in the position shown in the drawing, but when the device passes over one of the iron bars 3 the flux induced by the coil 6 is very greatly increased because the air gap between the ends 7 O and 71 is much better bridged by the iron 3. The increase in flux is sutli'cient to cause the part 10 to be attracted toward the iron in 71 more strongly than the spring 13 can resist; consequently, the iron member 10 moves downwardly and 10 comes in sliding contact with both contact points, bridging them and thus affording a closure 'for the circuit 15 illustrated in Figure 1.

This circuit includes a battery 1G which may or may not be the same as the battery 5 as is desired. Thecircuit also includes an electroresponsive device 17 whichshall give a response Vwhenever the vehicle passes over a point guarded by one of theV iron bars 3. This electro-responsive device may be of any type desired. It may give a signal, or set thek brakes, or make a record, or shut oli? power, or do all of these things, as the designer wishes. No invention is claimed in the particular electro-responsive device used, all of these functions being well known to workers in this art.

.In the modification shown in Figures 4 and 5 but'one end ot the U-shaped core'4 is illustrated. rJhis has aV depending end 18 ter` minating in a plate 19 adapted to pass in close proximity to the bars 3 already described. Pivoted to the end 18 are a pair of arms 20 and 21 which support a plate of iron 22. At the lower end of the arms 2O and 21 are a pair or contact makers 23 which, when the arms swing about their pivotapproaching the end member 18, will come into sliding contact with the terminals 24 and so close a circuit. The plate 22 and the arms 2O and 21 are held from swinging in this way by the spring 25. Under ordinary circumstances this spring is strong enough to overcome the magnetic attractionv and Vkeep the plate 22 in the illustrated position. lVhen the device passes over one ot the bars 3 the two ends of the core 4 are bridged by this bar and the magnetic iluX is greatly increased; consequently, the attraction of the end 18 for the plate 22 is increased and will now overcome the spring 25. The members therefore turn about their pivots and the parts 23 and 24 come into Contact which is sufficient to close the circuit 15. Y

In this form ot the device, the main magnetic circuit is through the core 4 and the depending ends 18 from which it goes through the air to the body uponthe track. There is a branch magnetic circuit. It the arms 2O and 21 are of sott iron, this branch is easily traced. Tt leaves the main magnetic circuit at the pivoted ends of these arms and goes through the arms to the iron member 22 and from there, it returns to the mainY mag` netic circuit through the air in the illustrated position or through the end 23 of the arms 20 and 21 in the attracted. position. It is, therefore, evident that when the attraction occurs, the branch Vmagnetic circuit i ap` proaches the main magnetic circuit.

1f the arms 20 and 21 are not of magnetic material, a similar branch circuit may still be regardedl as present. v It goes through` the airrom the Vdepending ends 18 tothe upper edge of the plate 22 and returns through the air from the lower edge ot Vthis plate to a lower point upon the depending ends 18.

1n the modification illustrated in Figures 6 and 7 one end only of the core 4 is illustrat` ed on a horseshoe formed magnet. Upon this core is the winding 6 which may be near the ends or not as the designer wishes. The core 4 ends in a pole 26. Attached to the core above and below the winding is a bracket 27 preferabyv of non-magnetic material. This bracket carries a pair of pivot pins 28, 28. These pivot pins support a movable part 29 of iron which is very close to the part 26 at the gap 30. Articulated with `the outer end of the member 29 is a vertical piece 31 which may be pivoted'to 29 or may be v rigid therewith. A hole 32 through the end of the bracket. 27 may be large enough to permit the motion of the part 31 even when it is not pivoted. At the upper end of the part 31 is an iron plate 33 which is insulated by the layer 34 of insulation and below this is the conducting plate` 35. The whole is held in an upward position by the spring 36. When the parts in question are depressed the plate 35 will come into contact with thel terminals 37 and close the circuit 15.

The spring 36 may be suificient to keep the parts normally elevated or it may be substituted for or supplemented by a magnetic arrangement to hold the parts up. This is illustrated at 38 where a soft iron bar is shown coming to the point immediately over 33. The other end of this bar is held close to the far end of the U-shaped frame 4 and so has a polarity opposite to that of the plate 33. The spring 36 or the combined effect oi: this spring and the magnet 38 is sulicient to maintain the parts 39 in the illustrated position under normal conditions. When the device passes over an iron bar 3 the magnetic iuX between the `parts 29 and the bar '3 is suiiicient to lower the part 29 and cause the plate 35 to contact with the terminal 37 and so close the circuit. i

In this form of the device, the main mag@ netic circuit is through the core 4 to the pole piece 26, from there to the body of iron upon the track and from this body oli'iron to the pole piece at the other end ot the core 4. There is a branch magnetic circuit which leaves the main magnetic circuit at the righthand edge of the pole piece 26, as illustrated in Figure 6, and goes along the member 29 from which` it` goes through the air to the body of iron upon the track where it rejoins the main magnetic circuit.

The modification illustrated with a horseshoe magnetv in Figures 8I and 9V is closely similar to that illustrated in Figure 3, It shows a rounded housing 8 as part of poleshoe 71. This is applicable when the proximity of the part 10 to the'iron 8 is suiiicient to insure that this part will be 'attracted toward 8 and not toward the bar This modification may be adopted when conditions.

an air-tight cylinder or to act by gravity only.

In the modification illustrated in Figure 8, the main magnetic circuit is through the core 47 the pole piece 71, the rounded portion 8 of the housing and from the end of the pole piece through the air to the body of iron Vupon the track member whence it returns to the core 4 in the same way as with the other modifications. A branch magnetic circuit leaves the pole piece 71 at the left-hand edge of the inner surface of the rounded housing 8, as illustrated in Figure 8, and Vgoes through the insulation or through the air to the member 10. It then goes through the member 10 to the opposite edge thereof and from there through the insulation or air to the right-hand edge o1"- the housing 8. It will again be obvious that when the attraction occurs, the branch magnetic circuit approaches the main magnetic circuit.

In the modification shown in Figure 10 one end of the core 4 is illustrated and a portion of the winding 6. The core may be U-shaped and a 'further winding may be applied at the far end of it as is desired.V The core ends in a rounded pole 40. Mounted thereon with small bronze ball bearings is a movable piece 41 of soft iron which is separated from 40 by a very small air gap 42. This piece 41 pivots about the rounded ends 40 of the magnet. In the illustration it is to be understood that both ends of the core have moving poleshoes. It is held in the illustrated position against the weight of the part 45 of the piece 41 by the weight ot' levers 43 anda piston rod 44 which goes to a circuit controller 45 supported on the .trame 46 of the vehicle. This circuit con- 105 troller is controlled by a spring 47 which cooperates with the weight of the-parts just mentioned to hold the piece 41 in the illustrated position. The spring 47 acts against a plate 48 which is on the'end of the piston 110 rod. 44. This plate extends to the sides of the housing enclosing the circuit controller and serving to guide the movement of the movable contact 50. This contact is separated from the plate 48 by the linsulation 115 49. Situated at the otherlend of the travel of this plate are two pins 51 which are the terminals of the circuit 15. The force of the spring 47 added to the weight of the rod 44 and the levers 43 is ordinarily suiiicient 120 to keep the par-ts in the illustrated position but when the device passes over an iron bar 3 the magnetic tiuX is increased and the attraction between the bar 3 and the member 41 draws down the end 41 causing the mem- 125'- ber 41 to pivot about the end 40 of the magy net 4. This tilts the levers '43 and causes the rod 44 to move upward bringing the angularmember 50 into contact with the terminal 51 and closing the circuit 15. The 130 l guards. 52 prevent the member 41 from moving too iar downward. It may easily be seen that a sliding contact bridging another circuit can be had in the wall ot the circuit controller 45 or on 4l. to increase the current in 6 after a very small movement has begun and thus increase the strength of the magnet with little expenditure ofl electric current.

In this form of the device, the main magnetic circuit is through the core 4 into the left-hand end of the member 41, as illustrated in Figure 10. yFrom there, the main magnetic circuit is through the air to the body of iron upon the track and returns to the other end of the core 4 inf the same way as with the other modifications. The branch magnetic circuit leaves the main magnetic circuit at the end of the core 4 illustrated in Figure l0 and goes Valong the member 41 to its end 41. From there,rit goes through the air to the body of iron upon the track where it rejoinsthe main magnetic circuit.

In the modification rshown in Figure 1l the magneticy core 4'i's carried onV the vehicle by supports 57 preferably of non-magnetic material. Thel parts 5G of this core are turned downward and the end- 53' at one end oi the core is turned tow-ard the othercnd. At the other end. of the core there is an end member 54 which is pivoted at 55 to the part 5G. The magnetism produced. by the winding G induces an attraction between the parts 53 and 54, which ordinarily keeps these parts in the illustrated position, but when the device Vpasses over an iron rail 3 attraction of this rail for the part 54 causes it to tilt about. the pivot 55. The loose'joint 58 causestheV motion of the member 54 to be-imparted to the ball-crank whose armsv arey 60 and' 61' and which is pivoted at 59. The motion of this bell-crank causes the end of the arm 61 to rise bringing a plate 62 into Contact with the terminals 655 and closing the circuit 15; In this form of the device, the magnetic circuit is through the core 4 and through the end pieces 53 and 54. Between these end pieces, the magnetic circuit goes through the air. lhen the device is positioned over the body of iron 3 upon the track, the magnetic circuit leaves the end pieces 53 and 54 and goes through the air to the body ofiron 8. There is, however, some flux remaining between the inner ends of the poles 53 and 54. Although no sharp line of division between these two portions of the flux exists, either portion may be regarded as a branch magnetic circuit `and the otherportion as in the main magnetic circuit.

It will thus be seen that the invention provides a device for closing a circuit carried upon thev train eachl timethat the train passes a stationary'iron bar 3. These bars may be 1,411 acer placed at'the approach to aswitch or a curve or other dangerous points, or they maybe arranged to be movable, being depressed or tilted out of the way when there is no danger and brought back to operative position when danger exists. All of such arrangementsfare well known inthe art'and do' not constitute a part of this invention. It willbe noted that each of the modilications described includes a small movable part mounted upon themagnetic core or poleshoe and that'this partis moved by the cha-nge in the magnetic ux density which occurs when the irony bar 3 bridges the large air gapinthe'magnetic circuit. This feature is believed to be new in the art and possesses the vadvantage that the moving part although magnetic isfnot heavy and consequently the device maybe made sensitive and `effective without the eX- penditurel of any large amount of energy for the magnetizing current. V

Several parallel magnets with current from the same battery can be used in connection with parallel iron bars as the space taken up and cost involved is smal'l.V

Automobile roads can be supplied with cross rai'ls in the pavement with iron longitudinal connections like a grating at dangerous crossings for the useoia this device as it is very sensitive and does not need-'a long iron barto produce a signal and can be worked with permanent magnets reinforced by a small battery or reinforcedv at intervals. A soi't iron anchor may beL used on the magnet when the magnet is not in use..V

I am aware that numerous details of construction may be varied' through. a wide range without departing from the principles oithis invention, and-I th'erelfore do not purpose limiting the patent granted otherwise than necessita-ted' by theprior art.

I claim as my invention: l

1. In a device ot thecl'assdescribed, a vehicle, an incomplete magnetic circuit 'carried thereon, a body of magnetic material outside said vehicle adapted to complete said magnetic circuit when the vehicle passes said body except for the air gapneeded for clearance, a piece of magnetic materialen the vehicle separated fromv the main part of' the magnetic circuit by an air gap 'small com` pared tothe clearance air gap, said piece being adapted to be moved bythe increase i=n flux when the vehicle ypasses the body,rcon stantly acting means for returning theA piece after such movement, a Ycircuit closer controlled by saidA piece, a circuit controlled thereby, 'and a traffic .controlling device in said circuit.

2. In a railway signaling device, a magnetic circuit comprising a part on the vehicle and a magnetic body on the wayside, a member of magnetic'material movably mounted on the vehicle carried part of said magnetic circuit and constituting a portion of a branch tol magnetic circuit and a Contact controller carried by said movably mounted member, the Vehicle carried part also including :t source of magnetomotiveforce whereby upon the passage of the vehicle past the megnetic body on the Wayside the flux will be increased and the member of magnetic material so moved as to bring the branch magnetic circuit toward the first named magnetic circuit thereby actuating the Contact controller.

In testimony whereof I have hereunto Subscribed my name in the presence of tWo subscribing Witnesses.




Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3022398 *May 15, 1959Feb 20, 1962Fluidwick Company IncElectric control device
US5234184 *Nov 27, 1991Aug 10, 1993Union Switch & Signal Inc.Locomotive axle mounted cab signaling sensor
U.S. Classification246/63.00A, 246/197
International ClassificationB61L3/00, B61L3/12
Cooperative ClassificationB61L3/121
European ClassificationB61L3/12A