US2103416A - Railroad crossing signal - Google Patents

Railroad crossing signal Download PDF

Info

Publication number
US2103416A
US2103416A US80641A US8064136A US2103416A US 2103416 A US2103416 A US 2103416A US 80641 A US80641 A US 80641A US 8064136 A US8064136 A US 8064136A US 2103416 A US2103416 A US 2103416A
Authority
US
United States
Prior art keywords
secured
shaft
casing
platform
contacts
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US80641A
Inventor
Oscar T Gregory
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AUTO FLAGGER Corp
Original Assignee
AUTO FLAGGER CORP
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by AUTO FLAGGER CORP filed Critical AUTO FLAGGER CORP
Priority to US80641A priority Critical patent/US2103416A/en
Application granted granted Critical
Publication of US2103416A publication Critical patent/US2103416A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B61RAILWAYS
    • B61LGUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
    • B61L29/00Safety means for rail/road crossing traffic
    • B61L29/08Operation of gates; Combined operation of gates and signals
    • B61L29/18Operation by approaching rail vehicle or train
    • B61L29/22Operation by approaching rail vehicle or train electrically
    • B61L29/226Operation by approaching rail vehicle or train electrically using track-circuits, closed or short-circuited by train or using isolated rail-sections

Definitions

  • This invention relates to railroad crossing signals of the claimed.
  • Figure 1 is a side elevation illustrating a signal
  • Figure 2 is a View similar to Figure l showing the device when in non-signaling position.
  • Figure 3 is a fragmentary top plan View illustrating the combined mechanical and electrical Atlanta, Ga.
  • Figure 4 is a fragmentary vertical sectional view illustrating the saine as that shown in Figure 3.
  • Figure 5 is a side elevation illustrating a reversing switch for an electric motor employed for the actuation of the signals.
  • Figure 6 is a sectional View taken on the line 6 ⁇ 6 of Figure 5.
  • Figure '7 is an end elevation illustrating a main control switch.
  • Figure 8 is a 8-8 of Figure 7.
  • Figure 9 is a transverse sectional view showing the mounting for the nag type signal and taken on the line 9-9 of Figure 10.
  • Figure 10 is a sectional View ID-I of Figure 9.
  • Figure 11 is a fragmentary front elevation illustrating a portion of the flag.
  • Figure 12 is a sectional view taken on the line
  • Figure 13 is a sectional view taken on the line
  • Figure 14 is a diagrammatical view illustrating the wiring diagram.
  • the signals il and 6 are carried by a supporting structure l2 which includes a vertically arranged hollow post I3 supported by a suitable foundation i4 and a platform l5 mounted on the upper end of the post and to which is secured a horizontally arranged casing lli adapted t extend across the roadway at a desired height from the ground.
  • the signal 5 is mounted on the post i3 and the signal 6 is movable into and out of the casing lf3 so that when the signal S is in a signaling position it will be arranged transversely of the roadway of the crossing in a depending position with the lower edge terminating approximately theV height of a motor vehicle hood so that the signal B will be in alignment with the vision of the driver of the motor vehicle and also in a position so that the light rays of the headlamps of the motor vehicle will strike rthe flag and jewels thereon, rendering the characters clearly readable, as well as the other markings, at night time.
  • the markings and characters being of distinguishable colors maybe easily read in the day time.
  • the casing I6 is of substantially U-shape in the flag may readily move into and out of the casing and when confined in the casing will be protected against weather elements.
  • a partition Il is arranged in the casing towhich the upper edge of the flag is secured and forms a stop for the flag to fold against when moved upwardly in the casing.
  • the partition Il is apertured to permit the flexible elements i0 to extend therethrough and they also extend through slots I8 formed in the top of the casing.
  • a pair of pulleys I9 Yare journaled on the casing and have trained thereover a pair of flexible elements IB, while a third of the ilexible elements IB is trained over pulleys 2i) and secured to one of the flexible elements of said pair of flexible elements, as shown at 2l.
  • the pulleys 2i) are journaled on the casing.
  • the flexible elements after passing over the pulleys extend through a vertical wall 22 of the platform I5 and over guide pulleys 23 carried by said vertical wall 22.
  • the flexible elements after passing over the pulleys 23 are wound on and secured to drums 2d and the latter are secured to an operating shaft 25.
  • the operating shaft is rotatably mounted in supports 26 mounted on the platform I5.
  • a removable hood 21 overlies the pulleys i9 and '2li and the flexible elements after they leave the casing and pass to the drums.
  • the hood 21 is hinged to the casing, as shown at 28, and is equipped with a catch 29 to prevent the hood from accidentally swingingv into an open position.
  • a removable cover 29 is carried by the platform l5 to protect the mechanism supported by said platform from weather elements and from being tampered with.
  • a suitable locking mechanism (not shown) may be provided for securing the cover 2Q' in place on the the feed nut and the platform.
  • the casing I6 besides being secured at one end to the vertical wall of the platform has its opposite end connected to said vertical wall by supporting rods 30.
  • is supported by the platform and operatively connected to the shaft 23 for rotating the latter in opposite directions for the purpose of folding and unfolding the flag.
  • the mechanism 3i includes a reversible electric motor S2, the shaft thereof being connected to a stub shaft 33 by a coupling 34.
  • the stub shaft 33 is journaled in the support 35 mounted on the platform and has secured thereto a worm 36 which meshes with a worm gear 3l secured to the shaft 25.
  • the shaft also has secured theretoY a beveled gear 33 meshing with a beveled gear 3% secured to a feed shaft itil.
  • the feed shaft d has the usual feed threads thereon to be engaged by a feed nut fil.
  • the feed shaft lil is rotatably supported by standards i2 mounted on the platform.
  • the standards also slidably support a shaft d3 which parallels the feed shaft and has secured thereto stop collars 4 between which operates latter also contacts said collars for shifting the shaft 43 in opposite directions as the feed nut travels in opposite directions on the feed shaft
  • the feed nutJ is slid- ⁇ ably secured to the shaft 43 so that the feed nut will not follow the rotation of the feed shaft but which will travel endwise of said feed shaft.
  • An arm i5 is secured to one end of the shaft d'5 and has pivoted thereto a link 66.
  • the link 4S is pivoted to an actuating arm il mounted on a shaft L18.
  • Journaled on the shaft 48 is a sleeve rotatably supported by a bracket 5E secured to the platform l5.
  • the shaft 48 is free to turn in the sleeve RS.
  • a trip plate 5l is secured to the sleeve adjacent the actuating arm l1 and includes diverging arm portions 52 between which operates a pin 53 secured to the trip arm Gl.
  • a coil spring 5ft has one end secured to the trip arm 41 adjacent the latters free end and the other end of said spring is secured to the platform. The purpose of'the spring 5 is to cause the trip arm to snap past dead center position when movement of the arm lil is transmitted to the trip plate by the pin 53 contacting either of the arm portions 52.
  • the purpose'of the trip plate is to actuate a reversing switch 55, the latter being electrically connected in an electric circuit and in which is also connected the electric motor so that the latter will be reversed for the purpose of folding and unfolding the flag.
  • the reversing switch 55 includes a support Eli of insulating material mounted cn the platform to which are secured contacts El, 58, 59 and 6E?.
  • the switch 55 also includes a movable element El constructed of insulating material and is secured to the sleeve 49. Mounted on the movable element Gi of the switch 55 are contacts G2 and 63.
  • the movable element El of the switch 55 has two positions and when in one position the contacts @2 and 63 engage the contacts 5l and 52 and when in the other or second position, the contacts 62 and E3 engage the contacts 59 and GB.
  • the movable element El of the switch 55 is temporarily retained in either of its positions by a spring element iid engaging in notches E5.
  • An arm @E is secured to the sleeve A9 and pivoted to said arm is a connecting link 6l.
  • the connecting link 5l connects with a main control switch '68 mounted on the platform.
  • the main control switch 68 is of the electrically actuated i9 and the sleeve is moving in either direction.
  • The' a position within the casing l5, the various parts of the combined electrical and mechanical mechanism 3
  • a train entering the block energizes the magnet l and the latter attracts the movable contact element 69 engaging the latter with the contacts "l2 completing the electric circuit to l when freed from either oivits positions or" engaging the contacts ⁇
  • is mounted in guides 16 carried by the platform i 5 and pivoted to the block is a.
  • link l'l and tliel'atter is pivoted t'o a lever 'i8 adjacent the pivoted end ofy tire lo latter.
  • the lever 18 is pivoted, as shown at 75, to a support B forming apart ci the main switch.
  • e support 80 has the movable contact hinged thereto.
  • the other end of the lever 'i8 has the connecting rod 61 pivoted thereto.
  • 20 ing the movable Contact 69 is a stop 8
  • the conductor 85 is connected to its respective rail of the track a selected distance from 68 to the right in Figure 4.
  • the magnet 'IQ is deeneri0 connected to the latter are conductors 89 and S.
  • 'I'he signal 5 is connected in an electric circuit (not shown) and also in this circuit is connected a control switch 96 mounted on the platform l5 complete the movement of the trip arm to the and includes spaced contacts 91 adapted to be bridged by a pivotally mounted bridging element end of a coil spring
  • arrives at the end of its movement in one direction it imparts pivotal movement to the lever
  • a device for operating a railroad crossing signal comprising a supporting means, a shaft carried for rotation in opposite directions to move a signal into signaling and non-signaling positions, a reversible electric motor carried by the supporting means and connected to said shaft, a feed shaft driven by said first shaft, a sliding shaft carried by said supporting means, spaced collars secured to the sliding shaft, a feed nut meshing with the feed shaft and slidable on the sliding shaft between the collars, a reversing switch carried by the supporting means, a train controlled electric circuit connected to the reversing switch and to the electric motor, a main control switch connected to the circuit and including a hingedly mounted and weighted movable Contact and slidable spaced contacts and having the contacts thereof connected in the circuit, a trip mechanism actuated by the movement of the sliding shaft to operate the reversing switch and the movable contacts for the main switch, and an electromagnet connected in the electric circuit for the actuation of the weighted movable contact of the main switch.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Train Traffic Observation, Control, And Security (AREA)

Description

Bec. 28, 193?. o. T. GREGORY RAILROAD CROSSING SIGNAL Filed May 19, 1936 4 Sheets-Sheet 2 ATTORNEYs Dec. 28, 1937. o. T. GREGORY RAILROAD CROSSING SIGNAL Filed May 19, 1936 4 Sheets-Sheet 4 m w, 0 y, 7 W M www Patented Dec. 28, 1937 UNlTED STATES PATENT GFFICE Auto Flagger Corporation, Application May 19, 1936, Serial No.
1 Claim.
This invention relates to railroad crossing signals of the claimed.
For a complete understanding of my invention, reference is to be had to the following description and accompanying drawings, in which Figure 1 is a side elevation illustrating a signal Figure 2 is a View similar to Figure l showing the device when in non-signaling position.
Figure 3 is a fragmentary top plan View illustrating the combined mechanical and electrical Atlanta, Ga.
means for actuating the signals and having the cover for said mechanism removed.
Figure 4 is a fragmentary vertical sectional view illustrating the saine as that shown in Figure 3.
Figure 5 is a side elevation illustrating a reversing switch for an electric motor employed for the actuation of the signals.
Figure 6 is a sectional View taken on the line 6`6 of Figure 5.
Figure '7 is an end elevation illustrating a main control switch.
Figure 8 is a 8-8 of Figure 7.
Figure 9 is a transverse sectional view showing the mounting for the nag type signal and taken on the line 9-9 of Figure 10.
Figure 10 is a sectional View ID-I of Figure 9.
Figure 11 is a fragmentary front elevation illustrating a portion of the flag.
Figure 12 is a sectional view taken on the line |2-|2 of Figure 11.
Figure 13 is a sectional view taken on the line |3-I3 of Figure 11.
Figure 14 is a diagrammatical view illustrating the wiring diagram.
Referring in detail to the drawings, the nusectional view taken on the line taken on the line that they may be ob- 2 cross section so that 2 cate danger. Rows of grommets or eyelets 9 are secured to the flag 6 and have laced therethrough flexible supporting elements it each having one end secured to the flag adjacent the free end of the latter. Reinforcing strips l l are secured to the fabric of the flag where the eyelets pass through the fabric and these reinforcing elements are of the type to cause the fabric of the flag to fold when the lower edge of the flag is drawn upwardly in the direction of the upper edge.
The signals il and 6 are carried by a supporting structure l2 which includes a vertically arranged hollow post I3 supported by a suitable foundation i4 and a platform l5 mounted on the upper end of the post and to which is secured a horizontally arranged casing lli adapted t extend across the roadway at a desired height from the ground. The signal 5 is mounted on the post i3 and the signal 6 is movable into and out of the casing lf3 so that when the signal S is in a signaling position it will be arranged transversely of the roadway of the crossing in a depending position with the lower edge terminating approximately theV height of a motor vehicle hood so that the signal B will be in alignment with the vision of the driver of the motor vehicle and also in a position so that the light rays of the headlamps of the motor vehicle will strike rthe flag and jewels thereon, rendering the characters clearly readable, as well as the other markings, at night time. The markings and characters being of distinguishable colors maybe easily read in the day time. Y
The casing I6 is of substantially U-shape in the flag may readily move into and out of the casing and when confined in the casing will be protected against weather elements. A partition Il is arranged in the casing towhich the upper edge of the flag is secured and forms a stop for the flag to fold against when moved upwardly in the casing. The partition Il is apertured to permit the flexible elements i0 to extend therethrough and they also extend through slots I8 formed in the top of the casing. A pair of pulleys I9 Yare journaled on the casing and have trained thereover a pair of flexible elements IB, while a third of the ilexible elements IB is trained over pulleys 2i) and secured to one of the flexible elements of said pair of flexible elements, as shown at 2l. The pulleys 2i) are journaled on the casing. The flexible elements after passing over the pulleys extend through a vertical wall 22 of the platform I5 and over guide pulleys 23 carried by said vertical wall 22. The flexible elements after passing over the pulleys 23 are wound on and secured to drums 2d and the latter are secured to an operating shaft 25. The operating shaft is rotatably mounted in supports 26 mounted on the platform I5. A removable hood 21 overlies the pulleys i9 and '2li and the flexible elements after they leave the casing and pass to the drums. The hood 21 is hinged to the casing, as shown at 28, and is equipped with a catch 29 to prevent the hood from accidentally swingingv into an open position. The hood when in closed position contacts the casing and a flange on theV vertical wall 22 of the platform so as to exclude weather elements from the interior of the hood thereby protecting the ilexible elements and pulleys. A removable cover 29 is carried by the platform l5 to protect the mechanism supported by said platform from weather elements and from being tampered with. A suitable locking mechanism (not shown) may be provided for securing the cover 2Q' in place on the the feed nut and the platform. The casing I6 besides being secured at one end to the vertical wall of the platform has its opposite end connected to said vertical wall by supporting rods 30.
A combined electrical and mechanical means 3| is supported by the platform and operatively connected to the shaft 23 for rotating the latter in opposite directions for the purpose of folding and unfolding the flag. The mechanism 3i includes a reversible electric motor S2, the shaft thereof being connected to a stub shaft 33 by a coupling 34. The stub shaft 33 is journaled in the support 35 mounted on the platform and has secured thereto a worm 36 which meshes with a worm gear 3l secured to the shaft 25. The shaft also has secured theretoY a beveled gear 33 meshing with a beveled gear 3% secured to a feed shaft itil. The feed shaft d has the usual feed threads thereon to be engaged by a feed nut fil. The feed shaft lil is rotatably supported by standards i2 mounted on the platform. The standards also slidably support a shaft d3 which parallels the feed shaft and has secured thereto stop collars 4 between which operates latter also contacts said collars for shifting the shaft 43 in opposite directions as the feed nut travels in opposite directions on the feed shaft The feed nutJ is slid-` ably secured to the shaft 43 so that the feed nut will not follow the rotation of the feed shaft but which will travel endwise of said feed shaft. An arm i5 is secured to one end of the shaft d'5 and has pivoted thereto a link 66. The link 4S is pivoted to an actuating arm il mounted on a shaft L18. Journaled on the shaft 48 is a sleeve rotatably supported by a bracket 5E secured to the platform l5. The shaft 48 is free to turn in the sleeve RS. A trip plate 5l is secured to the sleeve adjacent the actuating arm l1 and includes diverging arm portions 52 between which operates a pin 53 secured to the trip arm Gl. A coil spring 5ft has one end secured to the trip arm 41 adjacent the latters free end and the other end of said spring is secured to the platform. The purpose of'the spring 5 is to cause the trip arm to snap past dead center position when movement of the arm lil is transmitted to the trip plate by the pin 53 contacting either of the arm portions 52. The purpose'of the trip plate is to actuate a reversing switch 55, the latter being electrically connected in an electric circuit and in which is also connected the electric motor so that the latter will be reversed for the purpose of folding and unfolding the flag. The reversing switch 55 includes a support Eli of insulating material mounted cn the platform to which are secured contacts El, 58, 59 and 6E?. The switch 55 also includes a movable element El constructed of insulating material and is secured to the sleeve 49. Mounted on the movable element Gi of the switch 55 are contacts G2 and 63. The movable element El of the switch 55 has two positions and when in one position the contacts @2 and 63 engage the contacts 5l and 52 and when in the other or second position, the contacts 62 and E3 engage the contacts 59 and GB. The movable element El of the switch 55 is temporarily retained in either of its positions by a spring element iid engaging in notches E5.
An arm @E is secured to the sleeve A9 and pivoted to said arm is a connecting link 6l. The connecting link 5l connects with a main control switch '68 mounted on the platform. The main control switch 68 is of the electrically actuated i9 and the sleeve is moving in either direction. The' a position within the casing l5, the various parts of the combined electrical and mechanical mechanism 3| Figure 4. A train entering the block energizes the magnet l and the latter attracts the movable contact element 69 engaging the latter with the contacts "l2 completing the electric circuit to l when freed from either oivits positions or" engaging the contacts `|2 or T3. The block 711| is mounted in guides 16 carried by the platform i 5 and pivoted to the block is a. link l'l and tliel'atter is pivoted t'o a lever 'i8 adjacent the pivoted end ofy tire lo latter. The lever 18 is pivoted, as shown at 75, to a support B forming apart ci the main switch.
e support 80 has the movable contact hinged thereto. The other end of the lever 'i8 has the connecting rod 61 pivoted thereto. 20 ing the movable Contact 69 is a stop 8| wardly of the casing and assume signaling posi- The electric motor signal 5. As the nut 4| Figure 4 it engages one of the collars 44 causing rail of the track has the conductor S3 connected The conductor 85 is connected to its respective rail of the track a selected distance from 68 to the right in Figure 4. However, when the train leaves the block the magnet 'IQ is deeneri0 connected to the latter are conductors 89 and S.
ment with the Contact 'I3 completing the electric circuit to the motor 32. However, the reversing switch having had the element 6| thereof shifted switch. A conductor 92 connects the Contact 58 of the reversing switch to the conductor 9| and the conductor 93 connects the contact 5'! of the and to the contacts 62 and 63 of the reversing switch 55.
'I'he signal 5 is connected in an electric circuit (not shown) and also in this circuit is connected a control switch 96 mounted on the platform l5 complete the movement of the trip arm to the and includes spaced contacts 91 adapted to be bridged by a pivotally mounted bridging element end of a coil spring |00 is connected to the arm to one end of a pivotally mounted lever |0| lever is forked, as shown at |02 to receive a pin ID3 secured to the feed nut 4|. When the feed nut 4| arrives at the end of its movement in one direction it imparts pivotal movement to the lever |0| causing the element motor stopping the operation of the motor as the signal 6 is completely folded within the casing.
4| reaches the limit of its movement in an oppo- 4| to the left in Figure 3 brings about a pivotal movement of the lever itl so as to disengage the bridging element 98 and the contacts B7 after the train has left the block for interrupting the circuit to the electric signal 5. The stop 8| on the lever 'I8 prevents the movable contact element 69 of 75 for driving the drums 24 in a direction to unfold lo to the right in Figure 4 and at the same time the 30 gized and the weight 'I5 acts to move the contact i0 and at the same time the block 'I4 is shifted to 50 Therefore, it will be seen that al1 parts of the 55 by said means the main switch B8 from following the contact 'i3 when the latter is moved away from said contact 69 so as to assure said contact 69 assuming a perpendicular position when the various parts of the mechanism have been restored to their initial position and after the folding of the signal 6.
Having described the invention, I claim:
A device for operating a railroad crossing signal comprising a supporting means, a shaft carried for rotation in opposite directions to move a signal into signaling and non-signaling positions, a reversible electric motor carried by the supporting means and connected to said shaft, a feed shaft driven by said first shaft, a sliding shaft carried by said supporting means, spaced collars secured to the sliding shaft, a feed nut meshing with the feed shaft and slidable on the sliding shaft between the collars, a reversing switch carried by the supporting means, a train controlled electric circuit connected to the reversing switch and to the electric motor, a main control switch connected to the circuit and including a hingedly mounted and weighted movable Contact and slidable spaced contacts and having the contacts thereof connected in the circuit, a trip mechanism actuated by the movement of the sliding shaft to operate the reversing switch and the movable contacts for the main switch, and an electromagnet connected in the electric circuit for the actuation of the weighted movable contact of the main switch.
OSCAR T. GREGORY-
US80641A 1936-05-19 1936-05-19 Railroad crossing signal Expired - Lifetime US2103416A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US80641A US2103416A (en) 1936-05-19 1936-05-19 Railroad crossing signal

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US80641A US2103416A (en) 1936-05-19 1936-05-19 Railroad crossing signal

Publications (1)

Publication Number Publication Date
US2103416A true US2103416A (en) 1937-12-28

Family

ID=22158662

Family Applications (1)

Application Number Title Priority Date Filing Date
US80641A Expired - Lifetime US2103416A (en) 1936-05-19 1936-05-19 Railroad crossing signal

Country Status (1)

Country Link
US (1) US2103416A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2864911A (en) * 1955-06-23 1958-12-16 Ite Circuit Breaker Ltd Mechanism for motor operation of a circuit breaker
US2864912A (en) * 1955-06-23 1958-12-16 Ite Circuit Breaker Ltd Motor operated circuit breaker
US2870288A (en) * 1955-06-23 1959-01-20 Ite Circuit Breaker Ltd Motor operated circuit breakers

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2864911A (en) * 1955-06-23 1958-12-16 Ite Circuit Breaker Ltd Mechanism for motor operation of a circuit breaker
US2864912A (en) * 1955-06-23 1958-12-16 Ite Circuit Breaker Ltd Motor operated circuit breaker
US2870288A (en) * 1955-06-23 1959-01-20 Ite Circuit Breaker Ltd Motor operated circuit breakers

Similar Documents

Publication Publication Date Title
US1929859A (en) Photo-electric cell controls for highway barriers
US2103416A (en) Railroad crossing signal
US1832812A (en) Safety gate
US1661051A (en) Crossing safety device and operating mechanism therefor
US1914359A (en) Automatic railroad crossing gate
US1639866A (en) Gate for railroad crossings
US1604014A (en) Railroad-crossing gate
US2228909A (en) Railroad crossing gate and signal
US1666559A (en) Automatic electric railroad-crossing gate
US1818013A (en) Railroad crossing gate
US1326009A (en) A trust estate
US1806497A (en) Automatic crossing gate
US1577173A (en) Automatic vehicle stop for railroad crossings
US1575248A (en) Crossing gate
US1879919A (en) Electrical means for operating or raising and lowering railway booms and the like
US1064673A (en) Danger-signal for railways.
US1853934A (en) Crossing gate
US1348367A (en) Automobile
US1531745A (en) Traffic signal
US1551541A (en) collins
US1518176A (en) Signal
US1550538A (en) Warning and stop system
US1419661A (en) Automobile traffic signal
US1830011A (en) Automatic crossing gate
US1628663A (en) Automatic railway signal