US1767104A - Flasher signal - Google Patents
Flasher signal Download PDFInfo
- Publication number
- US1767104A US1767104A US256499A US25649928A US1767104A US 1767104 A US1767104 A US 1767104A US 256499 A US256499 A US 256499A US 25649928 A US25649928 A US 25649928A US 1767104 A US1767104 A US 1767104A
- Authority
- US
- United States
- Prior art keywords
- armature
- contact
- plates
- supported
- wire
- 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
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H51/00—Electromagnetic relays
- H01H51/30—Electromagnetic relays specially adapted for actuation by ac
- H01H51/32—Frequency relays; Mechanically-tuned relays
Definitions
- This invention relates to circuit makers and breakers and particularly to circuit makers and breakers known as flashers and adapted to operate periodically at spaced intervals for controlling the operation of lights placed at traflie intersections, railroad crossings, and the like.
- the lights designed to be controlled by our invention are classed as warning lights, operating at intervals of a second or two, as distinguished from control lights designed to regulate the flow of traffic.
- a further object of the invention is to provide for adjustment of the flasher whereby the duration and frequency of the flash may be controlled to meet the desired conditions.
- Another object is to provide a device which may be operated from a battery or other source of current to control the light directly, or which may be embodied in a control circuit to vary the operation of a light which is normally lighted from the conventiona].
- alternating current sources as is fully described in our copending application, Se-
- a still further object of the invention is to provide for the complete insulation of all the contacts one from another and from the framework and supporting structure of the device so as to eliminate all danger of short circuits which would serve to injure the delicate mechanism.
- Another object is to provide means, built in the supporting walls of the device, for restraining certain parts against movement during the shipping thereof.
- Figure 1 is a perspective view of the structure assembled within a protecting casing.
- Figure 2 is a perspective View similar to Figure 1 but with the casing removed.
- Figure 3 is a side elevation, partly in section, with casing and one of the supporting plates removed.
- Figure 4 is an exploded View showing certain details of the armature construction together with appended parts.
- Figure 5 is a fragmentary view showing the means for holding the armature rigid during shipment.
- 1 designates a suitable base provided with four binding posts designated 2, 3, 4 and 5, respectively. These binding posts are each insulated from the base 1 by suitable means such as Washers 6. Supported by the base 1 and secured thereto are two spaced upright plates 7 and 8. These plates are rigidly joined by bars 7.
- the plate 7 is provided at its upper end with two inwardl projecting flanges 9 and 10, one at each 0 the vertical sides of said plate.
- a pole 12 of an electromagnet 13 To each of the flanges 9 and 10 is securely fastened, by screws or other means 11, a pole 12 of an electromagnet 13.
- An armature 14 is fixedly mounted on a shaft 15, said shaft being mounted in bearings 16 located in the plates 7 and 8, so the armature and shaft swing as a unit with said bearings as pivot points.
- the armature is so mounted as to move at the slightest impulse, and carries at one end thereof a weight 17 or similar means for normally inclining the armature from the horizontal.
- Armature 14 carries a contact member 18.
- This member consists of a long resilient member fastened at one end 19, to the armature 14 on the side of the shaft 15 which isopposite to the side to which the weight 17 is attached, and whose other end extends the length of the armature at an angle thereto and carries the contact point 20.
- the contact point 20 is approximately under the weight 17 and is adapted to rotate in the same direction as said weight when the armature is moved.
- the end 19 of the contact member 18 is completely insulated from the armature 14 by insulating strips 21 and 22 placed on each side thereof as shown in F igure 4, the said insulating strip 21 is carried to the end of the armature, to prevent short circuit, when the spring 18 is compressed at the lowermost movement of the armature, when in operation.
- the contact point 20 cooperates with a contact surface 23 carried on a resilient arm 24.
- the arm 24 is mounted at an angle to the base 1 and is supported by an angle bracket 25 fixed to the side plate 7
- a rigid bar 26 also supported by the bracket 25 serves to limit the deflection of the resilient arm 24.
- the bracket 25, arm 24 and bar 26 are completely insulated from each other by insulating strips 27, 28 and 29.
- the bar 26 also serves to limit the movement of the contact member 18, and the resilient arm 24, and thereby in consequence of such limitation, prevents the armature from rocking beyond center, in its counterclockwise movement, which would, for obvious reasons, be undesirable. It should be noted at this point that the contact between resilient contact member 18 and resilient contact member 24 is, in the operation of the device, a wiping contact, thus keeping the contact points always clean, insurin perfect contact with each movement of t e armature.
- Two resilient contact arms 30 and 31 carrying the contact points 32 and 33 respectively, which points are normally separated, are mounted vertically to the base plate 1 and at one side of the armature 14. These arms are such length that they extend slightly above the shaft 15. They are rigidly supported at their lower ends by an angle bracket 34 mounted on the side plate 7. The contact arms are insulated from each other and froin the supporting bracket by insulating strips 35, 36 and 37.
- a cam member 38 made of insulating material is mounted on the end of the shaft 15 adjacent the contact points 32 and 33, and is rigidly afiixed so as to rotate with the shaft. The cam member has a hardened ti 39 to permit of increased wear at this point. It will be apparent that rotation of the armature 14, shaft 15 and cam 38 clockwise will cause the tip 39 of the cam to press the resilient arm 30 toward the arm 31 and thus close the contacts 32 and 33 for a purpose to be hereafter described.
- connection is made between the electromagnet 13 and the contact member 18 carried by the armature 14, 'by means of a coiled spring 40.
- This spring 40 is rigidly supported at one end, nearest the electromagnet, by a forked member 41, this member being in turn supported by the side plate 8 and insulated therefrom by a washer 42.
- a wire 43 leads from this end of the spring to one end of the magnet coil.
- the other end of the coiled spring is attached to a crosspiece 44 carried by the armature and closing the circuit to the contact arm 18, to which insulated cross piece 44 leads, which piece is also insulated from the armature.
- the means for holding the armature 14 rigid against oscillation during shipment of the device comprises a resilient member 45 ( Figure 5), riveted or otherwise affixed to the side plate 8 at one end of its ends, and having the other end supplied with a fork 46.
- a resilient member 45 Figure 5
- the resilient member is forced inwardly, as by means of a screw 47, carried by the protecting cover 48, and passing .through the hole 49 in side plate 8, the
- forked end 46 secures the armature 14 between its two prongs and thus holds it firmly against movement.
- the device is wired as follows: assuming 2 and 3 to be the input binding posts from the source of current, and 4 and 5 to be the output posts to the device to be operated, for example a lamp 55, a wire 50 leads directly from input post 3 to output post 6. Likewise a wire 51 runs from input post 3 to one end of magnet coil 13. There is also a wire 52 running from post 2 to contact member 23, and a wire 53 running from this same post to contact arm 30 carrying contact point 32. A wire 54 leads from contact point 33 and arm 31 to binding post 4. As previously explained, contact member 18 carrying contact point 20 is connected to the other end of magnet coil 13 by the wire 43, through coil spring 40.
- Armature 14 being unbalanced lies normally inclined at an angle so that contact points 20 and 23 are in engagement.
- - Current supplied at the input posts 2 and 3 will therefore pass from post 2 through wire 52 to contact surface 23, thence through contact point 20, wire 43, magnet coil 13 and wire 51 to binding post 3, thus completing the circuit and energizing magnet coil 13.
- the coil being energized will rotate the armature 14 clockwise about the pivots 16, thereby rotating the cam 38 in the same direction until the tip 39 of the cam forces the contact point 32 against the contact oint 33, thus closing a circuit as follows: rom binding post 2 through wire 53, contact points 32 and 33, wire 54, binding post 4, lamp 55, post 5, wire 50 to binding post 3.
- the cam 38 is adjustable on the shaft 15 by means of the set screw 56. This permits regulation of the length of time the lamp is lighted during each cycle of operation, as the armature 14 always moves a predetermined distance and the cam can be made to close the contacts 32 and 33 at any desired point in the clockwise movement of the armature 14.
- the base plate 1 is preferably provided with oppositely disposed holes 57, for the passage of screws whose ends engage the internally threaded openings 58 in bosses 59 at the lower edge of the casing, so that the mechanism may be c0mpletely housed and the device handled as a unit.
- the upper side of the casing is provided with a finger ring 60 by which the device may easily be carried or hung up.
- a base vertical spaced plates supported by said base, an armature pivoted between said plates, an electromagnet supported by said plates, said magnet having depending poles, means attached to one end of said armature for causing it to be normally positioned at an angle to the horizontal, a contact member carried by said armature, a contact member supported by one of said vertical plates and adapted to contact with the contact member carried by said armature when said armature is in its angular position, a pair of vertical contact members also supported by one of said plates, said contacts being normally open, and a cam member actuated by movement of said armature to close said vertical contact members.
- a base vertical spaced plates supported by said base, an armature pivoted between said plates, an electromagnet supported by said plates, said magnet having depending poles, means attached to one end of said armature for causing it to be normally positioned at an angle to the horizontal, a contact member carried by said armature, a contact member supported by one of said vertical plates and adapted to contact with the contact member carried by said armature when said armature is in its angular position, a pair of vertical contact members also supported by one of said plates, said contacts beingnormally open, a cam member actuated by movement of said armature to closesaid vertical contact members, and insulating means between each of said vertical contact members and between said members and the vertical plate.
- a base vertical spaced plates supported by said base, an armature pivoted between said plates, an electromagnet supported by said plates above said armature, means attached to one end of said armature for causing it to be normally positioned at an angle to the horizontal, a contact member carried by said armature, insulating means between said contact member and said armature, a contact member supported angularly by one of said vertical plates, insulating means between said contact member and said plate, said secondnamed contact member adapted to contact with the contact member carried by said armature when said armature is in its angular position, a pair of vertical contact members also supported by one of said plates, said contacts being normally open, and an insulated cam member actuated by movement of said armature to close said vertical contact members.
- An electro-magnet having a pair of spaced and opposed poles, a bar armature pivoted between said poles and having one end weighted to cause it to assume a position diagonally across lines of magnetic force between the poles, a contact carried by said armature, a fixed contact in the path of the first contact and engaged thereby in the diagonal position of the armature, a movable third contact adjacent the axis of the armature, a fourth contact in the path of the third contact, and means on the armature engaging the third contact to move it into engagement with the fourth contact upon energization of the magnet.
- An electro-magnet having a pair of spaced and opposed poles, a bar armature pivoted between said poles and having one end weighted to cause it to assume a position diagonally across lines of magnetic force between the poles, a contact carried by said armature consisting of an elongated strip of spring metal having one end mounted on but insulated from said armature and its other end provided with a contact point, a fixed contact in the path of the first contact and engaged thereby in the diagonal position of the armature, a movable third contact adjacent the axis of the armature, a fourth contact in the path of the third contact, and means on the armature engaging the third contact to move it into engagement with the fourth contact upon energization of the magnet.
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Electromagnets (AREA)
Description
June 24, 1930. F. c. VOLKMAN El AL FLASHER smrm.
Filed Feb. 24, 1928 2 Sheets-Sheet 1 June 24, 1930, F. c. VOLKMAN ET AL FLASHER SIGNAL Filed Feb. 24, 1928 2 Sheets-Sheet 2 Patented June 24, 1930 UNITED STATES -PATENT QFFICE FREDERICK C. VOLKMAN AND SIDNEY C. VINCENT, OF BALTIMORE, MARYLAND FLASHER SIGNAL Application filed February 24, 1928.
This invention relates to circuit makers and breakers and particularly to circuit makers and breakers known as flashers and adapted to operate periodically at spaced intervals for controlling the operation of lights placed at traflie intersections, railroad crossings, and the like. The lights designed to be controlled by our invention are classed as warning lights, operating at intervals of a second or two, as distinguished from control lights designed to regulate the flow of traffic.
It is an object of this invention to produce such a circuit breaking device or flasher which will be simple in construction, low in cost, and reliable in operation, and one that is especially compact, facilitating its installation in small and inexpensive housings.
A further object of the invention is to provide for adjustment of the flasher whereby the duration and frequency of the flash may be controlled to meet the desired conditions.
Another object is to provide a device which may be operated from a battery or other source of current to control the light directly, or which may be embodied in a control circuit to vary the operation of a light which is normally lighted from the conventiona]. alternating current sources as is fully described in our copending application, Se-
rial Number 256,498, filed February 24, 1928.
A still further object of the invention is to provide for the complete insulation of all the contacts one from another and from the framework and supporting structure of the device so as to eliminate all danger of short circuits which would serve to injure the delicate mechanism.
Another object is to provide means, built in the supporting walls of the device, for restraining certain parts against movement during the shipping thereof.
Other objects and advantages of my invention will be readily apparent from the following description and accompanying drawings, wherein:
Figure 1 is a perspective view of the structure assembled within a protecting casing.
Serial No. 256,499.
Figure 2 is a perspective View similar to Figure 1 but with the casing removed.
Figure 3 is a side elevation, partly in section, with casing and one of the supporting plates removed.
Figure 4 is an exploded View showing certain details of the armature construction together with appended parts.
Figure 5 is a fragmentary view showing the means for holding the armature rigid during shipment.
Referring to the drawings, 1 designates a suitable base provided with four binding posts designated 2, 3, 4 and 5, respectively. These binding posts are each insulated from the base 1 by suitable means such as Washers 6. Supported by the base 1 and secured thereto are two spaced upright plates 7 and 8. These plates are rigidly joined by bars 7. The plate 7 is provided at its upper end with two inwardl projecting flanges 9 and 10, one at each 0 the vertical sides of said plate. To each of the flanges 9 and 10 is securely fastened, by screws or other means 11, a pole 12 of an electromagnet 13. An armature 14 is fixedly mounted on a shaft 15, said shaft being mounted in bearings 16 located in the plates 7 and 8, so the armature and shaft swing as a unit with said bearings as pivot points. The armature is so mounted as to move at the slightest impulse, and carries at one end thereof a weight 17 or similar means for normally inclining the armature from the horizontal.
Armature 14 carries a contact member 18. This member consists of a long resilient member fastened at one end 19, to the armature 14 on the side of the shaft 15 which isopposite to the side to which the weight 17 is attached, and whose other end extends the length of the armature at an angle thereto and carries the contact point 20. Thus the contact point 20 is approximately under the weight 17 and is adapted to rotate in the same direction as said weight when the armature is moved. The end 19 of the contact member 18 is completely insulated from the armature 14 by insulating strips 21 and 22 placed on each side thereof as shown in F igure 4, the said insulating strip 21 is carried to the end of the armature, to prevent short circuit, when the spring 18 is compressed at the lowermost movement of the armature, when in operation.
The contact point 20 cooperates with a contact surface 23 carried on a resilient arm 24. The arm 24 is mounted at an angle to the base 1 and is supported by an angle bracket 25 fixed to the side plate 7 A rigid bar 26 also supported by the bracket 25 serves to limit the deflection of the resilient arm 24. The bracket 25, arm 24 and bar 26 are completely insulated from each other by insulating strips 27, 28 and 29. The bar 26 also serves to limit the movement of the contact member 18, and the resilient arm 24, and thereby in consequence of such limitation, prevents the armature from rocking beyond center, in its counterclockwise movement, which would, for obvious reasons, be undesirable. It should be noted at this point that the contact between resilient contact member 18 and resilient contact member 24 is, in the operation of the device, a wiping contact, thus keeping the contact points always clean, insurin perfect contact with each movement of t e armature.
Two resilient contact arms 30 and 31 carrying the contact points 32 and 33 respectively, which points are normally separated, are mounted vertically to the base plate 1 and at one side of the armature 14. These arms are such length that they extend slightly above the shaft 15. They are rigidly supported at their lower ends by an angle bracket 34 mounted on the side plate 7. The contact arms are insulated from each other and froin the supporting bracket by insulating strips 35, 36 and 37. A cam member 38 made of insulating material is mounted on the end of the shaft 15 adjacent the contact points 32 and 33, and is rigidly afiixed so as to rotate with the shaft. The cam member has a hardened ti 39 to permit of increased wear at this point. It will be apparent that rotation of the armature 14, shaft 15 and cam 38 clockwise will cause the tip 39 of the cam to press the resilient arm 30 toward the arm 31 and thus close the contacts 32 and 33 for a purpose to be hereafter described.
Connection is made between the electromagnet 13 and the contact member 18 carried by the armature 14, 'by means of a coiled spring 40. This spring 40 is rigidly supported at one end, nearest the electromagnet, by a forked member 41, this member being in turn supported by the side plate 8 and insulated therefrom by a washer 42. A wire 43 leads from this end of the spring to one end of the magnet coil. The other end of the coiled spring is attached to a crosspiece 44 carried by the armature and closing the circuit to the contact arm 18, to which insulated cross piece 44 leads, which piece is also insulated from the armature.
The means for holding the armature 14 rigid against oscillation during shipment of the device comprises a resilient member 45 (Figure 5), riveted or otherwise affixed to the side plate 8 at one end of its ends, and having the other end supplied with a fork 46. When the resilient member is forced inwardly, as by means of a screw 47, carried by the protecting cover 48, and passing .through the hole 49 in side plate 8, the
forked end 46 secures the armature 14 between its two prongs and thus holds it firmly against movement.
The device is wired as follows: assuming 2 and 3 to be the input binding posts from the source of current, and 4 and 5 to be the output posts to the device to be operated, for example a lamp 55, a wire 50 leads directly from input post 3 to output post 6. Likewise a wire 51 runs from input post 3 to one end of magnet coil 13. There is also a wire 52 running from post 2 to contact member 23, and a wire 53 running from this same post to contact arm 30 carrying contact point 32. A wire 54 leads from contact point 33 and arm 31 to binding post 4. As previously explained, contact member 18 carrying contact point 20 is connected to the other end of magnet coil 13 by the wire 43, through coil spring 40.
The operation of the device is as follows: Armature 14 being unbalanced lies normally inclined at an angle so that contact points 20 and 23 are in engagement.- Current supplied at the input posts 2 and 3 will therefore pass from post 2 through wire 52 to contact surface 23, thence through contact point 20, wire 43, magnet coil 13 and wire 51 to binding post 3, thus completing the circuit and energizing magnet coil 13. The coil being energized will rotate the armature 14 clockwise about the pivots 16, thereby rotating the cam 38 in the same direction until the tip 39 of the cam forces the contact point 32 against the contact oint 33, thus closing a circuit as follows: rom binding post 2 through wire 53, contact points 32 and 33, wire 54, binding post 4, lamp 55, post 5, wire 50 to binding post 3. At the same time the clockwise movement of the armature has opened the circuit through the contacts 20 and 24, so that the magnet 13 becomes deenergized and permits the armature 14 to resume its starting position, by reason of the weight 17. Thereupon the cam 38 releases the contacts 32 and 33, opening the lamp circuit, and the contacts 20 and 24 are again closed. The cycle of operations is continuously repeated as long as current is applied at the binding posts 2 and 3.
The cam 38 is adjustable on the shaft 15 by means of the set screw 56. This permits regulation of the length of time the lamp is lighted during each cycle of operation, as the armature 14 always moves a predetermined distance and the cam can be made to close the contacts 32 and 33 at any desired point in the clockwise movement of the armature 14.
It will be seen from the foregoing description that I have provided a circuit making and breaking mechanism which is simple in construction, reliable in operation, easily adjustable and with few moving parts, and at the same time of a size enabling it to be housed in small and comparatively inexpensive housings.
The base plate 1 is preferably provided with oppositely disposed holes 57, for the passage of screws whose ends engage the internally threaded openings 58 in bosses 59 at the lower edge of the casing, so that the mechanism may be c0mpletely housed and the device handled as a unit. For further convenience, the upper side of the casing is provided with a finger ring 60 by which the device may easily be carried or hung up.
While I have shown and described a specific form of my invention, it will be readily apparent that other forms might be adopted, all coming within the scope of the following claims.
Claims.
1. In combination, a base, vertical spaced plates supported by said base, an armature pivoted between said plates, an electromagnet supported by said plates, said magnet having depending poles, means attached to one end of said armature for causing it to be normally positioned at an angle to the horizontal, a contact member carried by said armature, a contact member supported by one of said vertical plates and adapted to contact with the contact member carried by said armature when said armature is in its angular position, a pair of vertical contact members also supported by one of said plates, said contacts being normally open, and a cam member actuated by movement of said armature to close said vertical contact members.
2. In combination, a base, vertical spaced plates supported by said base, an armature pivoted between said plates, an electromagnet supported by said plates, said magnet having depending poles, means attached to one end of said armature for causing it to be normally positioned at an angle to the horizontal, a contact member carried by said armature, a contact member supported by one of said vertical plates and adapted to contact with the contact member carried by said armature when said armature is in its angular position, a pair of vertical contact members also supported by one of said plates, said contacts beingnormally open, a cam member actuated by movement of said armature to closesaid vertical contact members, and insulating means between each of said vertical contact members and between said members and the vertical plate.
3. In combination, a base, vertical spaced plates supported by said base, an armature pivoted between said plates, an electromagnet supported by said plates above said armature, means attached to one end of said armature for causing it to be normally positioned at an angle to the horizontal, a contact member carried by said armature, insulating means between said contact member and said armature, a contact member supported angularly by one of said vertical plates, insulating means between said contact member and said plate, said secondnamed contact member adapted to contact with the contact member carried by said armature when said armature is in its angular position, a pair of vertical contact members also supported by one of said plates, said contacts being normally open, and an insulated cam member actuated by movement of said armature to close said vertical contact members.
4. An electro-magnet having a pair of spaced and opposed poles, a bar armature pivoted between said poles and having one end weighted to cause it to assume a position diagonally across lines of magnetic force between the poles, a contact carried by said armature, a fixed contact in the path of the first contact and engaged thereby in the diagonal position of the armature, a movable third contact adjacent the axis of the armature, a fourth contact in the path of the third contact, and means on the armature engaging the third contact to move it into engagement with the fourth contact upon energization of the magnet.
5. An electro-magnet having a pair of spaced and opposed poles, a bar armature pivoted between said poles and having one end weighted to cause it to assume a position diagonally across lines of magnetic force between the poles, a contact carried by said armature consisting of an elongated strip of spring metal having one end mounted on but insulated from said armature and its other end provided with a contact point, a fixed contact in the path of the first contact and engaged thereby in the diagonal position of the armature, a movable third contact adjacent the axis of the armature, a fourth contact in the path of the third contact, and means on the armature engaging the third contact to move it into engagement with the fourth contact upon energization of the magnet.
6. An=.electro-magnet having a pair of spaced and opposed poles, a bar armature pivoted between said poles and having one end weighted to cause it to assume a position diagonally across lines of magnetic force between the poles, a contact carried by said armature, a fixed contact in the path of the first contact and engaged thereby in the diagonal position of the armature, a movable third contact adjacent the axis of the armature, a fourth contact in the path of the third contact, a cam mounted on the axis of said armature and having a projecting portion engageable with the third contact to move it into engagement with the fourth contact upon energization of said magnet.
In testimony whereof We afiix our signatures. FREDERICK C. VOLKMAN.
SIDNEY C. VINCENT.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US256499A US1767104A (en) | 1928-02-24 | 1928-02-24 | Flasher signal |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US256499A US1767104A (en) | 1928-02-24 | 1928-02-24 | Flasher signal |
Publications (1)
Publication Number | Publication Date |
---|---|
US1767104A true US1767104A (en) | 1930-06-24 |
Family
ID=22972460
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US256499A Expired - Lifetime US1767104A (en) | 1928-02-24 | 1928-02-24 | Flasher signal |
Country Status (1)
Country | Link |
---|---|
US (1) | US1767104A (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2438609A (en) * | 1945-02-19 | 1948-03-30 | James G Juhasz | Circuit control device |
US2476106A (en) * | 1946-03-27 | 1949-07-12 | Aerotec Corp | Electric motor follow-up transmitting apparatus |
US2503493A (en) * | 1944-09-28 | 1950-04-11 | James G Juhasz | Starter winding cutout for motors |
US2538700A (en) * | 1946-12-26 | 1951-01-16 | Clarence L Mershon | Synchronizing relay |
US2542734A (en) * | 1947-04-19 | 1951-02-20 | Tucker Robert | Electric make-and-break device |
US2574082A (en) * | 1949-04-02 | 1951-11-06 | Smidth & Co As F L | Roto-vibrator |
US2626364A (en) * | 1946-03-20 | 1953-01-20 | Leo H Underwood | Electric fence controller and method of operation |
US2718568A (en) * | 1952-08-19 | 1955-09-20 | Connecticut Valley Entpr Inc | Rotary type relays |
US2798171A (en) * | 1955-08-05 | 1957-07-02 | Maxwell Rubin And Les Scherer | Direct current pulser device |
-
1928
- 1928-02-24 US US256499A patent/US1767104A/en not_active Expired - Lifetime
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2503493A (en) * | 1944-09-28 | 1950-04-11 | James G Juhasz | Starter winding cutout for motors |
US2438609A (en) * | 1945-02-19 | 1948-03-30 | James G Juhasz | Circuit control device |
US2626364A (en) * | 1946-03-20 | 1953-01-20 | Leo H Underwood | Electric fence controller and method of operation |
US2476106A (en) * | 1946-03-27 | 1949-07-12 | Aerotec Corp | Electric motor follow-up transmitting apparatus |
US2538700A (en) * | 1946-12-26 | 1951-01-16 | Clarence L Mershon | Synchronizing relay |
US2542734A (en) * | 1947-04-19 | 1951-02-20 | Tucker Robert | Electric make-and-break device |
US2574082A (en) * | 1949-04-02 | 1951-11-06 | Smidth & Co As F L | Roto-vibrator |
US2718568A (en) * | 1952-08-19 | 1955-09-20 | Connecticut Valley Entpr Inc | Rotary type relays |
US2798171A (en) * | 1955-08-05 | 1957-07-02 | Maxwell Rubin And Les Scherer | Direct current pulser device |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US1767104A (en) | Flasher signal | |
US1970412A (en) | Means for opening and closing circuits at regular intervals | |
US2156684A (en) | Electrical relay | |
US2156685A (en) | Electrical relay | |
US2025859A (en) | Oscillating motor circuit controller | |
US2143074A (en) | Timing device | |
US1647858A (en) | Electric signal | |
US2855583A (en) | Signal devices | |
US1169991A (en) | Electric signaling system. | |
US1555563A (en) | Burglar alarm | |
US1214624A (en) | Alarm for railroad-crossings. | |
US1160243A (en) | Wigwag-flagman. | |
US1321635A (en) | Electric railway-signal | |
US1937403A (en) | Electric bell | |
US571043A (en) | George ross green | |
US1032880A (en) | Electromechanical device for controlling electric signals. | |
US964289A (en) | Electric time-switch. | |
US1862773A (en) | Railway signaling flasher | |
US1296360A (en) | Time-controlled highway-crossing alarm. | |
US1728746A (en) | cannella | |
US2294196A (en) | Circuit making and breaking device | |
US2513206A (en) | Electrical fence | |
US2056674A (en) | Solenoid motor | |
US494832A (en) | Electric clock | |
US727124A (en) | Motor. |