US2236298A - Traffic signal controller - Google Patents

Description

March 25, 1941. a A. REID TRAFFIG sismm CONTROLLER Filed April 23, 1938 3 Sheets-Sheet 1 mmmm lTiventons Ralph A. Reid,

His Attorney zawm March 25, 1941. R. A REID TRAFFIC SIGNAL coa'rRQLLsR Filed April 23, 1938 3 Sheets-Sheet 2 Ivnbov: Ralph A. Reid l lis AOt owneg R. A. REID TRAFFIC SIGNAL CONXRDLLER MardTZS, 1941.

3 Sheets-Sheet 5 Filed April 23-, 1938 Inventor: Ralph A. Reid fvu fM His Attorney.

Federated Mar. 25, 3941 entrant carton TRAFFIC SIGNAL CONTRMER Ralph A. Reid, Nahant, Mass... 'assignor to (General Electric Company, a corporation of New York Application April 23, 193%, Serial. No. 263,888

8 Claims.

My invention relates to signal controllers, and more particularly to trafilc signal controllers. This application is a continuation in part of my application S. N. 105,684, filed. October 15,

One object of my invention is to provide an improved traific signal controller which is simple in construction, reliabl in operation, and capable of performing respectively the several functions required of apparatus of this type.

Another object of my invention is to provide an improved indicating means for the cycle length setting of the traffic signal timer.

Another object of my invention is to simplify the structure of .the controller to increase its ings, and its scope will be pointed out in the appended claims.

The term timer" is herein used to designate the timing mechanism and the contacts for controlling the timing and sequence of energization of a group of traflic signals. It includes the driving motor and the mechanism necessary to accomplish an accurately timed and adjustable control of the circuits to the signals. The term controller is used to designate the complete apparatus forcon-tnolling a group of signals for an intersection, including a casing in which is mounted the timer, rthe switchboard, the manual contrcl switch and any other auxiliary device that may be required to accomplish the necessary control of the trafiic signals.

In the accompanying drawings, Fig. 1 is a front perspective view of my improved trafiic signal cont-roller; Fig. 2 is a perspective view of a key used in the setting of the timer; Fig. 3 is a perspective rear view of the timer; Fig. 4. is an exploded view of the bottom of the timer and theterminal board normally attached thereto; Figs.

5, 6, 7, 8, 9, 10, and 11 are fragmentary views of elements of the timing mechanism; and 12 is a diagram of connection of a controller and a group of intersection signals.

Referring to the drawings in detail, Fig. 1 il1ustra'tes a front perspective of an intersection con troller comprising a casing 5, a timer 8 supported on hinges 1 and 8, and a terminal and switchboard 9 mounted on the rear wall of the casing 5 below the timer 8. A flexibl cable I connects the timer 3 to terminals on the switchboard 9 and a cable ll coects the switchboard terminals to the mtersection signals. A hand-operated switch I? with a suitable length cable 63 is connected to the switchboard terminals 55. It is used to manually operate the traffic signals, and when not in use is stored in the bottom of the casing 5. The switchboard has mounted thereon lin fuses i5 and a fuse it connected into the system synchronizing conductor, terminals ll for the con-j ductors in cable M, and a hand operated switch 10 it used for changing the controller from normal sequence operation to flashing amber signal oporation.

In Fig. 1, only the control panel 5' of the timer 6 is illustrated in detail. It is provided with a 3 circular opening 69 in which a dial rotates. On the lower side of this opening, a notch 21 having an arcuate length of about is provided in which a. pointer 22 is'positioned to indicate the length of time required for a complete revolution of the dial 20, or in other words, the length of a complete timecycle. In the specific timer illustrated, the indlcia under the pointer indicate that a range of time cycle length is provided which is adjustable between 40 and 180 seconds;

ranged in a circl about the center of the dial in which keys 2 3 and 543, as shown in Fig. 2, are

placed. The -relative position of these keys to each other determines the-relative lengths of the 39 is longer. The placing of this key in on of the slots 25 determines the relationship of the signal time cycle to other cycles in the system.

Fig. 2 illustrates in perspective a key 2 3. It is an elongated sheet metal member having a body of such cross-section that it may be easily moved 4i} through a slot 23 and of such length as to engage and operate contacts mounted in back of the dial. It is provided with a head 2i which isnotched to Zorm a shoulder 2i and a handle-30. The key 2' is the same as key 23, except that its body is (it? longer. The key "3 is similar to key 24% except that it is longer and is provided with a notch M3 (Fig. 12). In operation, the keys are placed in their respective slots until each head 2? engages the surf-ace of the dial and prevents any further 59 movement inwardly. A disc 28 provided with an opening 29 is then mounted on the dial by means of a thumb screw 38. This disc is of such diame'ter that it engages the shoulders 2?? of the keys at, and th opening 2a is so placed that its edge g 28 The dial 2c is provided with radial slots 23 arhandle ends of the keys 26 project over the edge of the disc 28 and thereby indicate their respective positions. The handle 30 of the key 28 proj'eots through the opening 29 and indicates its posit-ion relatively to the keys 24. I

The panel of the timer 6 is further provided with three control switches mounted in a horizontal row below the timer dial. Switch 32 controls the signal circuits.- Switch 33 controls the automatic and hand operation of the signals and.

switch 34 controls the timer motor circuit.

The panel 6' is further provided at its upper right-hand corner with a lug 35 in which a screw 36 is mounted which engages a threaded opening in a lug 31 on the casing ill. By means of this lug and screw arrangement, the timer may be secured in the casing,and if desired, may be unlocked and swung outwardly about its hinges I and 8.

The mechanism of the timer is illustrated in Fig. 3. This figure is a perspective rear view of the timer having a cover 38, shown in Figs. 1 and 4, removed to expose the mechanism. This mechanism consists essentially of a driving motor connected to drive the dial 20, a contact-block which supports contacts actuated by the keys in the dial 20, and of a drum controller with its operating mechanism arranged to operate the drum controller step by step in response to actuations of the contacts by the keysin the dial.

The driving motor indicated generally by the numeral 4|! is preferably a self-starting syn-- chronous motor of the type disclosed in U. S. Patent 1,430,867 issued to H. E. Warren. It com prises a tubular casing 42 attached to a larger casing 42. The tubular casing encloses an armature shaft which is connected to speed reducing gears in the casing 42. The speed reducing gears drive the shaft 43 (see Fig. 12) which is referred to as the motor shaft. A field 44 mounted on the casing 42 effects a rotation of the armature and motor shaft. when it is energized. The motor 40 is a modification of the motor described in the above Warrempatent in that the casing 42 is lengthened and two armatures are provided on the shaft therein. One of the armatures cooperates with the field 44 and the second armature cooperates with a field 45. The two fields 44 and 45 are mounted on the casing 42 in operative relation to the two armatures, respectively, to effect a rotation of said armature shaft in opposite directions. The fields are of equal strength, so that if they are simultaneously energized, the armature and motor shafts are stopped. Only one field, field 45, is therefore normally energized and the may be stopped instantly provides a precise control of the timer, from a remote point since the motor will not coast after the braking current is applied. The above-described motor stops and starts instantly and no inaccuracy results when the timer resynchronizes with the master timer.

As stated in the description of Fig. 1, the dial 20 rotates in the opening IQ of the panel. In order to support the dial it is mounted on a shaft 5| (see Fig. 12) which projects through a bearing in a yoke 56. The yoke is attached to the back of the panel 6' near the rim of the opening l9 and extends, across the opening. The front surface of the dial is substantially parallel aesaaoe to and spaced slightly inwardly from the surfue of the panel and the surface of the yoke is suiiicientiy spaced from the back surface of the dial to permit the keys extending from the back surface of the dial, to move freely with the dial. A gear 52 is attached to the end of the shaft 5| projecting through 'the. yoke. This gear is removable and may be replaced by other gears 52, 53, and 54. These latter gears are stored, for convenience, on a pin 55 on shelf 56 which projects from the lower edge of the panel 6'.

The gear 52 on the dial shaft'is driven by a pinion 51 on the end of the motor shaft 43. In order to support the motor 49 to maintain a driving relation between the pinion 51 and the gear 52,'or one of the other available gears, the motor is mounted on a plate 46. This plate is pivoted at one corner on a screw 47 which is screwed into a lug 48 projecting from the yoke 50. The cycle length indicating pointer 22 is attached to another corner of the plate and moves with the plate 46 when the latter is moved about its pivot to place the motor pinion 51 into engagement with one of the gears placed on the dial shaft. Since each gear corresponding to a end. A washer is placed under the head of this screw and projects over the edge of the plate 46. When the screw 58 is tightened, it pinches the edge of this plate 46 between the end surface of the lug and the surface of the washer thereby preventing any movement of the plate about its pivot.

The motor, being a synchronous motor, runs at a speed dependent upon the frequency of the current which is supplied thereto. This frequency being maintained constant, the dial speed is determined by the gear ratio between the motor and dial shafts. The time required by the dial to make one complete revolution determines the length of a cycle of operation, and the physical spacing of thekeys in the dial slots determines the time intervals into which a cycle is divided. This possibility of changing the dial speed together with the large number of possible changes in spacing between keys provides a flexibility which adapts the timer for use at substantially all trafilc intersections.

In order to convert the above-mentioned dial speeds and key spacings into correspondingly timed trailic signal operations, contacts are provided on the back of the panel and placed in the path of movement of the keys so that the keys will actuate the contactsand close circuits which set into motion the operating mechanism of the drum controller at the desired time intervals to change the traffic signal circuits. The contacts which are to be operated by the dial keys are mounted in the contact block 4| mounted above the dial on the back surface of the panel.

In Fig. 5 the contact block 4| is illustrated in cross-section to expose one of three pairs of contacts mounted therein. The three pairs of contacts are mounted side by side, the pair nearest the surface of the panel being arranged to be actuated by keys 24, in the slots 23, the second pair is actuated by the key I43 also in a slot 23 aaaaaes and the third pair being arranged for operation by the longest key 26 in one of the slots 25. The

cross-sectional view of Fig. exposes the third pair of contacts which are to be actuated by the key 26, These contacts 6i and 62 are respectiveiy mounted on resilient contact springs 83 and 64 which are respectively attached to the back end of the block H and project through a slot as in the block to the other end thereof. The free end of the upper contact spring is bent upwardly to form a hook 66 the end of which engages the upper surface of the block and limits its own movement downwardly. Considerable space is left, however, for it to move upwardly with the contact Bl when the lower contact spring 8 with contact 62 is lifted so that the two contacts engage.

The springs and contacts of the other two pairs of contacts are the same as the pair just described. To enable the keys 24, I43 and 2G to move the lower contact of each pair upwardly,

each lower contact spring is provided with a block preferably-formed of insulating material and provided with a beveled end. The block on contact spring 63 is shown at 81 and the blocks on the other two lower contact springs are shown at 68 and 933. (See Figs. 5 and 12.) In Fig. 5, block 61 is partly broken away to show block 68 which in this view is directly behind it. The block 6'! stands in the path of movement of key 26; the block 68 stands in the path of movement of the key 3 and the block E33 stands in the path of movement of key 24. The p rp se of the notch M3 in key 3 is to permit key I43 to pass block i 33, without engaging it. The dial 26 revolves in a clockwise direction, as viewed in Fig. 12, and as the respective keys reach the blocks $1, 68, I33, they engage the beveled surfaces thereof to lift the respective contacts.

It is of considerable advantage to mount these three pairs of contacts in the common block it since they may in this manner be together adiusted in relation to the dial, and their relation to each other remains unchanged. The circuits operated by each of these three pairs of contacts will be described in connection with the connection diagram Fig. 12.

The trams signal circuits are controlled by a drum controller which operates in response to the contact actuations by the dial. This drum con troller designated generally by the numeral 69, includes a drum comprising a shaft 776, a group of discs it, its, 655, its, tar and E58, and a ratchet wheel 32, The shaft is horizontally mounted below the driving motor as by bearings at each end thereof. One bearing is locatedin a lug d3 projecting from one side of the panel and the other bearing is located in a bearing member it attached to a lug projecting from the other side of the panel.

' Fig. 9 is a front perspective of the drum illustrating the ratchet wheel '52 at one end of the shaft 70 and the group of discs adjacent to each other and next to the ratchet wheel. The discs are illustrated, in this figure, with all theirrim sections in place; the desired sections being broken oii just before the drum is placed into the controller. The discs and ratchet wheel may be attached to the shaft is in any convenient manner. In the illustrated drum, the ratchet wheel is fastened to shaft ll! by a set screw, and the discs are mounted on the square portion of the shaft, are spaced from each other by spacing collars 1 I which may or may not be integral with the discs, and are held in fixed position by a collar it" placed against the last disc and fastened to the shaft by a set screw.

Fig. 10 discloses an end View of one of the discs, for example, disc lbs. The disc is made of an insulating material, preferably a molded insulating compound such as a phenolic condensation Product with a filler. A number of radial slots divide the rim of the disc into sections. Directly under the rim the disc is reduced in thickness so that any one of the rim sections may be readily broken ofi. The disc I59 is shown with one such section broken away. The purpose of this will become apparent by reference to Fig. 8. In this figure, an end view of disc .l58, which is similarito disc 7i and has one rim section broken away is illustrated with a contact arm 91 riding on the rim of the disc. The contact arm holds the contacts 98 and NH separated as long as it rides on the rim. when the drum is turned to the position at which the broken away section of the rim is in line with the end of contact arm 81, the arm moves inwardly until the contacts 98 and IN engage and close an electric circuit.

For the purpose of rotating the drum in response to the contact actuations by the dial keys, a solenoid with a pawl and ratchet mechanism is provided. This mechanism may be described by reference to Figs. 3 and 6. It comprises a pawl 78 pivotally mounted on a crank 11 which in turn is pivoted on the shaft 10, and a solenoid having its armature or plunger attached to the free end of the crank for intermittently raising it. This solenoid includes a laminated rectangular core 18 which is pivotally suspended on a lug l9, by a pin 80, at one side of the dial, A coil 82 in the core raises an armature 82 when it is energized and releases it when deenergized. The

armature is connected to.the crank by a pin 83.

When the coil 8! is energized by the closure of contacts operated by the dial, it draws the armature t2 upwardly, thereby lifting the crank ll, causing it to rotate The pawl l6 slides over the teeth of the wheel it during this clockwise movement. When coil 8! is deenergized, armature t2 and crank l7 move downwardly and during the downward movement pawl it engages a tooth of wheel 32, thus eiiectin a turning movement of the drum. A spring 8 wound about the pivot pin 85 for the pawl, and having its ends respectively attached to the pawl and crank, maintains the free end of the pawl in contact with the ratchet wheel l2 and causes it to engage a tooth face when the crank W moves counter-clockwise. In the present an rangement the ratchet wheel it together with the shaft it) and discs it are rotated on the counter-clockwise movement of the crank when clockwise about the shaft 70.

the coil til becomes deenergized and the crank drops due to, its own weight and that of the armatureiiZ connected to it. This is contrary to the usual arrangementv of ratchets but has a definite advantage. The advantage thereof is that since the weight of the crank and armature is constant a uniform force is available for turning the drum at each deenergization of the coil iii.

In order to limit the movement of the drum to a predetermined are at each operation, an im proved spring assembly is provided. This spring assembly may be described by reference to Figures 3, 6 and 7. It comprises a leaf spring 86 attached at one end to a lug 81 on the shelf at by screws 88. It extends upwardly at a slight angle to the vertical and at its upper end it is provided with a shoulder 89 extending across a portion of its width and an extension 9! extending across the remainder of its width. The extension 9i is bent approximately at right angles to the body of the spring and supports at its end, a second spring 92 which extends back along the extension 9i, its end rising slightly above the extension and ending slightly forward of the shoulder 99, As best shown in Fig. 3,'the upper end of leaf spring 86 terminates adjacent to the free end of pawl I6. Pawl l6 is provided with a notch which forms a forward end or nose 99 adapted to engage the teeth of ratchet wheel I2 and an abutment, or end surface 93', spaced back from the end of nose 93. Pawl 'I6 is narrower in width than ratchet wheel I2 and when in the position shown in Figs. 3 and 6, which, may be termed its normal position, abutment 93' engages the top edge of leaf spring 86 at one side of spring extension 9i with nose 93 projecting over and beyond such top edge. At this time, nose 99' lies alongside the second spring 92 with its end in line with the end thereof and with the end of nose 93 and the end of spring 92 both in engagement with the same tooth of the ratchet wheel I2. The function of this spring assembly is threefold. First, it prevents a clockwise rotation of the ratchet wheel when the coil 8| is energized to move the pawl 84 clockwise, second, on return movement of the pawl it prevents a movement of the drum due to its own momentum beyond the point to which it is carried by the pawl, and thirdly, it limits the travel of the pawl on the return movement. When the pawl I6 moves clockwise, due to the energization of coil 8i, the forward end of the spring 92 which is in engagement with the face of a tooth on the ratchet wheel I2, prevents this wheel being dragged 'by the pawl- I6 which slides over the teeth of the ratchet wheel during this movement. Upon the return movement of the pawl during which it engages a tooth face and rotates the ratchet wheel and drum, it moves toward the shoulder 89. At the end of its movement, its forward end 93 is directly over the shoulder 89 and is thereby looked into the tooth notch in which it happens to be. Any tendency on the part of the drum, therefore, to move beyond the position to which it is carried by the pawl is overcome and it is locked into that position. At this moment the end surface 93 of pawl I6 engages the upper end of spring 85. This stops the return movement of the pawl, the spring thereby forming a resilient stopforlimiting the return movement of the pawl and crank. The combining of the two springs 86 and 92 in the manner described greatly simplifies the adjustment of the shoulder 89 and the spring 92 with respect to pawl I6 and ratchet wheel I2. The spring 92 is made of such length that when abutment 93 on pawl I6 is in engagement with the upper end of spring 86, as shown in Fig.

6, the end of spring 92 is,in line with the free end of pawl 16. This forms a simple means for obtaining initially a correct relationship between the cooperating pawl and the spring surfaces. Spring 86 can be bent forward or backward to adjust it to the desired position with respect to ratchet wheel I2 so that when the drum is actuated, return movement of the pawl will be stopped to position correctly the ratchet wheel and the drum discs; and'when thus adjusted, it will be noted that since springs 86 and 92 form a unitary structure and are moved simultaneously, the relationship between the upper end of spring 86, which is engaged by pawl I6, and the end of spring 92 will be always-"maintained.

As stated above the controller drum controls drum and is supported in back ofand in spaced relation to panel 6' by a suitable number of bolts I I9 which thread into bosses I I I on block 95 andclamp the bosses against lugs I99 projecting from the face of panel 9'. In shelf 59, directly beneath block 95, is a rectangular opening H2 which extends the length of the block. Block 95 has a central forwardly projecting longitudinally extending portion 95 above and below which are upper and lower contact and terminal carrying portions 95 and 95. At its rear, block 95 is provided with a longitudinally extending terminal carrying portion 95 Extending transversely of portion 95 are dividing walls 96 which provide contact arm receiving grooves. In signaling systems of the type in which a controller of the character embodying my invention is used, the number of contact arms which may be required varies according to the particular conditions to be taken care of in any particular instance and block 95 is made long enough to provide a suflicient number of contact arm receiving grooves, or channels, to take care of maximum requirements, The contact arms are indicated at 9! and in the present instance, as will be seen from Fig. 3, seven contact arms 97 located in the seven left hand contact arm receiving grooves are shown. Each contact arm 91 comprises a flat strip of metal, for example, a sheet metal stamp-- I92 at the other end. In each contact arm, just above contact I92, is an opening I91. The stationary contacts 98 and 99 are mounted in rows above and below the dividing walls 96 and in line with the channel between each pair of walls 96. Contacts 98 are'mounted in the upper contact and terminal receiving portion 95 of block 95 and comprise contact heads ,oarried by threaded bolts 99 which project through portion 95 and are provided on their inner ends with terminal bolts 98'. Stationary contacts 99 are carried by contact strips II9 fastened to contact and terminal carrying portion 95 by screws I29. The lower ends of contact strips II 9 project below block 95 and through opening H2 in shelf 56 terminating below the lower face of the shelf. The contacts I9I and I92 on each contact arm 91 cooperate respectively with a contact 98 and a contact 99. Each contact arm 91 is held resiliently in position to cooperate with the stationary a head I94 and a bit I95. As best shown in Fig. 8,

key I93 extends through the opening I9'I in the contact arm and through a keyhole shaped opening I98 in block 95, the bit I 95 on the end of the key engaging a notch in the rear face of the block. A helical spring I96 is mounted on the key between the head I94 and the arm 91. For simplicity in manufacture, the key I93 may be stamped out of sheet metal. ,In assembling a contact on the block, the forward end of the key is inserted by simply hooking the bit end of the key through the hole I91 in the arm and thereafter moving the head end of the key upwardly until it is perpendicular to the arm. The bit end of the key is then moved through the key hole shaped opening I98 in the block after which the key is turned 99 and the bit I95 hooked into a suitable notch'in the back surface of the block.

The contact arm with its contacts is then held against the stationary contacts by the pressure of the spring its which is under compression between the head tilt and the contact arm. This method of holding the contact arm enables a quick removal of the arm for replacement or contact examination. When assembled, contact @632 is held firmly in engagement with contact as and contact idi is moved into and out of engagement with contact 98. Thus each contact arm functions to connect and disconnect its corresponding pair of contacts 93 and 9d.

Mounted on terminal carrying portion 95 of 7 block 95 are angularly shaped terminal strips HI, each having one arm fastened to the underside of portion 95' by terminal screws I22 and the other arm extending down through opening I I2 in shelf 55 in parallel relation to strips H9.

In order to control the engagement of the movable contacts IIII with the stationary contacts 98 the contact arms 91 extended upwardly so that their ends ride on the rims of the discs ii and IE6 to I59 inclusive. In the positions of the-drum, in which a discpresents an unbroken rim to the end of a contact arm 97, the contact IN on such arm is out of engagement with the corresponding stationary contact 98. When a disc is turned by'the rotation of the drum to a position where a broken away portion oi its rim is brought into line with the end of a contact arm, the contact arm moves inwardly to bring its contact IIlI into engagement with a stationary contact 96.

For the purpose of providing a convenient connection between the contacts on the block 95 and the conductors in cable In, there is provided a terminal board H3 fastened, by means of screws IN, over opening H2.

The terminal board Ii! is a rectangular board provided on its inner surface with a channel H5 extending lengthwise of the board from end to end and with grooves II 6 not as deep as the channel, extending across the width of the board at right angles to the channel I 55. Terminals Ill comprising resilient leaves are attached to the board by means of eyelets H8 into which conductors from the cable I are soldered; The

, leaves or the terminals extend outwardly of the rooves and over and above the surface of the channel. when the board is attached to the under side of the shell 56 these leaves engage the ends of terminal strips H9 and I20 which extend through the opening in the shelf.

Terminals II I are connected to the terminals on switchboard 9 by cable III and the terminals on the switchboard are connected to the outgoing circuits of cables II and I3.

Terminal board H3 is provided with a number of terminals III suhicient to make the requirednumber of connections to terminal strips 9 I 9 and I26. The number required and the arrangement varies in accordance with the requirements in any particular case.

With this arrangement, it will be seen that a timer as a. unit may be completely disconnected electrically by unscrewing the. screws HQ and removing terminal board H3, a thing which disturbs none of the wiring of the timer nor of the cable connections. This is a feature in the construction which is of substantial importance in that it enables the timer to be wired complete as a unit after which it may be mounted in casing and connected in the circuit by merely attachin; a terminal board II3. Likewise, switchboard 8 and terminal board H3 may be wired together as a unit, the wires being made into the cable iii.

In constructing a controller for a particular application, the timer may be assembled except for the drum and the contact arms 9i, and completely wired. Following this, a drum may be made up by taking a shaft 10 and mounting thereon the required number of disks with the correct segments broken out and a ratchet wheel having the required number of ratchet teeth and mounted in place in the timer. And then the required number of contact arms 9i may be slipped into place. This completes the timer. The timer may be now mounted in the controller casing. Next, a switchboard 9 and a terminal board I3 may be made up with the required number and arrangement of terminals and wired together as a unit and assembled in the controller casing, the terminal board being attached to the shelf to make the electrical connections to the timer. This completes the controller, it being now ready to be wired into the system in which it is to be used. It is wired into the system through the terminal connections on the front of the switchboard 9 as shown in Fig. 1.

Referring now to the diagram of connections, Fig. 12, we may trace the circuit connections and the sequence of operations of the apparatus just described. This figure discloses a circuit diagram including a perspective view of the dial 2!] with its keys and a skeleton view of the contacts operated thereby. A conventional trafiic signal having the well known three color signals designated by the letters R, A, and G is shown. Two

faces of this unit are illustrated one for each of conductor I29.

Conductor I28, which is permanently energized carries current to contact I30 which is one of the stationarycontacts in the block 4 I. The cooperating contact of this pair is contact I3I mounted on the spring I32. The contacts I30- I3I are the pair of contacts in the block 4| which is nearest to the dial 20. The lower contact I3I of this pair is lifted into engagement with upper contact I30 by each key 24 as the dial rotates.

Contacts B0 and HI arcin a circuit which includes the drum operating coil 8| and which may be termed the normal operating circuit. This circuit may be traced as follows: Source conductor I25, conductor I28, contacts I30-I3I,

contact arm E32, conductor I35, set of contacts 9lI029l98-IOI (as illustrated in Fig. 8) controlled by drum disc H, conductor I36, conductor I31, switch 33, conductor I38, coil 8|, to ground. Contact arm 9! controlled by disc H is in closed circuit position for all positions of the control drum except one. To this end, all but one of the segments of disc ii are broken away. In the present instance, ratchet wheel i2 has six teeth so that the drum has six positions, in five of which such contact arm is in closed circuit position and in the sixth in open circuit position. When contact I3I is moved into engagement with contact I39 by okay 2% at a time when the contact arm controlled by disc II is in closed position, the normal operating circuit through coil 8| is closed, thus energizing coil 8| and advancing the drum one step. Thus successive operations of the contacts Ian-m by the keys 24 at intervals determined by the spacings of the keys 24. However, if when contact I3I is moved into engagement with contact I30, the contact arm controlled by, disc II is in open circuit position, the normal operating circuit is not closed, and hence the drum is not advanced. Now, to efiect a further movement of the drum, there is provided through coil 6| 9. second circuit, which may be termed a local synchronizing circuit,

which circuit is in shunt with the normal operating circuit and includes the-contacts I40 and MI which are moved into engagement by local synchronizing key I43. When during rotation of dial 20, key I43 engages block 66 to move contacts I4I into engagement with contact I40, a circuit is closed through coil 8| as follows: from source conductor I25 through switch 32, conductor I29, switch I8, conductor I46, contacts I40-I4I, contact spring I42, conductor I36, conductor I31, switch 33, conductor I36 and coil 6! to ground. Closing of this circuit energizes coil 8| and causes the drum to be advanced one step. It will thus be seen that under normal operating conditions during each complete rotation of dial 20, the drum is given one complete turn in six successive steps, one step, which may be considered the first step, being effected by local synchronizing key I43 and the five following steps being effected by the five keys 24. The contact arms actuated by drum disces I54 to I59 inclusive control the circuits R. R1, G, G1, and A, A1 to the signal lamps, and discs I 54-459 inclusive are arranged in the drum controller with their broken away sections located in such relation to each other that with successive-actuations of coil 8|, first by local synchronizing key I43 and then by the five keys 24, the desired sequence of operation if the lamps is effected. And the keys i43I24 are spaced apart around the dial 20 to give the desired duration of signals for each drum position. Thus there is'a definite correct relationship between the drum position and the dial position which must be maintained for correct operation of the signal lamps. This correct relationship obtains as long as the drum position is in such relationship to the dial position that key I43 operates contacts I, I40 at a time when drum disc II has moved its contact arm 91 to open circuit position; that is, when the drum disc is moved to such position by the key 24 just in advance of key I 43. If the controller is started into operation with the drum and the dial not in correct relationship relatively to each other, then if it so happens that the drim'i is in the. position in which contact arm 91 is in open circuit position, no energization of coil 6I and operation of the drum will occur untii key I43 actuates contacts I4I, I40, keys 24 being inefi'ective to close the normal operating circuit since this circuit is opened by the drum disc 11. On the other hand, if the controller is started into operation with the drum and dial not in correct relative relationship but at a time when drum disc H is I in a position such that contact arm 91 is in closed relationship,.they will. be quickly brought into correct relationship during the first complete rotation of dial 20.

For automatic operation as-described above, switch 33 is in the position shown in Fig. 12, wherein it connects conductor I38 to conductor I31. To shift the signals from automatic to manual control, switch 33 is moved to 'connect conductor I38 to conductor I3. This connects coil 8! in circuit with push button I2 so that the drum may be turned manually step by step by successively closing switch I2. At any time, the signals may be shifted back to automatic control by moving switch 33 back to the Fig. 12 position.

And during the first complete rotation of dial 20,

'BI and 62 and the field winding 45 of motor 42 which circuit may be traced as follows: Source S, switch II, conductor I26, conductor I52, arm 64, contacts 62, 6t, and conductor I53. Switch I5I is normally closed and is opened periodically once during each complete rotation of I cam I50. Contacts 6|, 62 are normally separated and are closed once during each complete rotation of dial 20 by key 26 engaging block 61. During operation, if the controller at anintersection is in synchronism with the master controller, the time is such. that at the instant key 26 effects aclosing of contacts 6|, 62, cam E50 effects an opening of switch I5I with the result that the circuit through motor I45 is not completed and the intersection controller continues to operate in a normal manner. If, however, when key 26 effects a closing of contacts 6!, 62, cam I is in a position such that switch I5I is closed (which indicates that the intersection controller is out of the desired time relationship with the master controller), the circuit through motor windings 45 is completed and motor 42 is stopped due .to

the field 45. opposing field 44, and when thus Each controller of a group being similarly equipped will actuate a-similar pair of contacts at an instant during its operating cycle. If it is in synchronism it will continue to operate. If it is out of synchronism, it will stop and will start at the instant at which I5! is opened. The positioning of the key 26 in the slots 25 will therefore determine the relationship in which the controller and the signals operated thereby will be maintained by the above mechanism. in relationship to other controllers in the system.

The drum illustrated in the example controller is provided with seven discs of which disc 1I regulates the position of the drum relatively to the dial and the discs I54 to I59 control the red, green, and amber signals for two intersecting highways. As above stated, the contacts operated by each disc are normally separated and closed in only one or more positions of the drum, dependent upon the signalling cycle. The current for the signals is received through the switch 32, conductor i29, contacts of the switch I8, and a conductor I60 which is connected to each of the contacts 98 under the discs I56 to I59. When the discs are in proper position, the proper contacts close and the corresponding signals are energized through the cable ii.

The switch it is provided to control the circuits of the traffic signals and of a flashing mechanism to make it possible to operate only the amber signals and to operate them as periodically flashing signals. This type of operation is practical during periods of lighttrafnc. In the position shown in Fig. 12, the switch is in a position to connect the amber conductors A and A1 to the contacts of the drum controller, so that these signals are under control of the discs I58 and I59. When the switch is thrown to its second position, the conductor I29 which supplies the local current for operating the signals is separated from conductors I46 and I66 and no current flows to the drum contacts 99 through the conductor I60. Simultaneously, the conductors A and A1 are connected to a conductor I48. This conductor I48 is connected to a flashing mechanism mounted on the supporting plate 46 of the driving motor.

This flashing mechanism comprises a station ary contact I6I mounted ona contact arm I62 and a movable contact I63 mounted on a contact arm I64. The contact arms are both mounted on a contact block I65 which is suitably attached to the motor supporting plate 46. The arm I64 is pivoted to the block at its back end and is bent at right angles at its forward end to provide a nose I66. The end of this nose I66 rides on the periphery of a star wheel I61. When the star wheel rotates the nose I66 riding the periphery of the wheel causes an intermittent engagement of the contacts I6I, I63. Conductor I48 is connected to contact arm I64. Contact IGI is connected by a conductor I66 to the current supply conductor I29.

In operation, therefore, when the switch It is thrown to its second position it shuts off the current supply to the green and red lamps of the traffic signal unit and connects the ambler lamps to the current supply through the flashing mechanism so that as star wheel I6I rotates it operates contacts I6I, I63 to intermittently energize the amber lamps. Simultaneously, switch I6 disconnects conductor I46 and the resynchronizing contact I46 from the current supply thus opening the local synchronizing circuit. After this circuit has been opened, the drum will continue to be advanced by keys 24, operating contacts I30, I3I until it reaches the position at which disc It opens the drum advance coil circuit. The drum will then remain in that posito break the same circuit, by separating conductors I 46 and I29, at the switch contacts.

The switch 6Q may be opened to stop the dial at any chosen instance. By merely opening the switch 35. during the amber signal period, for example, it is possible to obtain a steady amber indication instead of a flashing amber indication as is the case when switch I8 is operated to its second position. An opening of both switches and 3 3 effects a complete shutdown of the controller.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a traffic signal timer, the combination of a drum controller, a group of contacts for trafiic signal circuits operated thereby, a dial, means for rotating said dial continuously, means for intermittently operating said drum controller in response to the continuous movement of said dial, means for maintaining synchronism between said drum controller and said dial comprising a synchronizing circuit including a switch opened by said drum when the latter is in a position to energize the right of way signals to the most important of a plurality of intersecting highways, and a second switch actuated by the dial to close the synchronizing circuit in shunt to said drum-operated switch when said dial reaches a predetermined corresponding. position in the timer, a secondary signaling device, means for simultaneously energizing said secondary signal device and making inefiective the dial-operated switch in said synchronizing circuit whereby said drum moves until it breaks its dial synchronizing circuit and resumes operation from that position when said last-mentioned means is operated to deenergize said secondary signal device and simultaneously to make effective the said dial-operated switch.

2. In a traflic signal timer, the combination of a drum controller, a group of contacts for trafiic signal circuits operated thereby, a dial, means for intermittently operating said drum controller in response to movement of said dial, means for maintaining synchronism between said drum controller and said dial, a secondary signaling device, means for simultaneously energizing said secondary signal device and operating said synchronizing means to effect a stopping of said drum controller at a predetermined position whereby upon' a change of signals of said controller from the normal sequence signals to the secondary signal, the drum will be advanced to a predetermined position whereby upon a return to normal operation a predetermined combination of signals will first be shown.

3. In a trafiic signal controller the combination of a signal circuit controller, means for advancing said controller step by step including a coil, an energizing circuit therefor, including a pair of normally open contacts operable to close said circuit to effect an operation of said advancing means, a continuously rotating dial, a'

motor for driving said dial at a predetermined speed, means for stopping said dial including a circuit and a pair of normally open contacts operable to close said circuit to energize said stopping means, an interlock between said signal circuit controller and said dial including a pair of normally closed contacts separated by said signal circuit controller when it assumes a predetermined position to open the circuit to the operating coil and a second pair of contacts operable to close a shunt circuit around said controller operated contacts, keys in said dial, and a common supporting block for the said operating coil circuit contacts, the said dial stopping contacts, and the said interlock contacts, said common support holding said three pairs of contacts in the path of movement of said keys whereby a common relationship is established between each pair of said contacts and said dial and therefore the spacing of said keys relatively to each other becomes the only adjustment necessary to establish the desired relative operation of said contacts.

4. In a trafiic signal controller, the combination of contacts for a drum controller, a group of traffic signal circuits operated thereby, a dial, means for intermittently operating said drum controller in response to movement or said dial, means for maintaining synchronism between said drum controller and said dial, a flashing mechanism, and means for making inefiective the contacts of said drum controller and for making effective said flashing device to energize one signal circuit and simultaneously operating said synchronizing means so that said drum controller will advance to one predetermined position and will not move beyond that position in response to dial operation until the contacts of said drum controller are again made efiective to control their respective circuits.

5. In a trafiic signal controller, th' combination of a contact operating drum, c 'ntacts for energizing the circuit of three-colored traflic signals including green, red, and amber signals, a control dial, means responsive to the operation of said control dial for advancing said drum stepby-step to establish predetermined combinations of said contacts so as to energize the corresponding traffic signals at each position thereof, an interlocking circuit between said dial, said drum, and said advance mechanism including a pair of contacts opened by said drum when it is in the main street green position, and means upon said dial for shunting said contacts when it reaches a predetermined correspondingrposition, a flashing mechanism, and a change over switch which is provided with contacts to make inefiective the contacts for said red and green signal circuits to make effective, said amber signal circuit contacts of said flashing mechanism and to simultaneously open the circuit of said shunting contacts whereby said drum will be advanced to the position at which the main street green contacts are closed after said flashing signal switch is operated andawhereby when said flashing signal switch isreturned to its normal position the first signal circuit closed will be the main street green signal circuit.

6.'In a traiilc signal system for controlling when such transfer i made said controller is stopped in a predetermined signalling position.

7. .;In a trafic signal system, a plurality of signals, movable means for operating said signals through a cycle of operations, a second means for operating at least one of said signals, means for disconnecting said signals from said movable means, and connecting said second means thereto, and means whereby when said signals are disconnected from said movable means such movable means is stopped in a predetermined position.

8. In a traflic signal system, a plurality of signals, a drum controller, circuit closers operated by said drum controller, circuits connecting the circuit closers to said signals, means for moving the drum controller through a cycle of successive positions, a second circuit closer, means for operating it, switch means for disconnecting the signals from said drum operated circuit closers and connecting at least one of said signals to said second circuit closer, and means whereby when said switch means is operated, said drum controller is stopped in a predetermined position corresponding to a certain signal display.

RALPH A. REID.

. CERTIFICATE .OF CORRECTION.

Patent No..2,256,298- March 25, 19in. I RALPH A. REID.

'It is hereby certified. that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, first column, line 63, for the-re'ference numeral "79" read "70"; page 5, first column, line 55, after "shelf." insert the following paragraph The terminals 117 011 the board 1.15 are arranged in two rows along the opposite sides of the board, each row extending over and above the channel surface 115 and engaging the two rows of terminal strips 119 and 121 projecting down from the block 95.

page 6, first column, line 51; for "disces" read'--discs-=-" line 59, for

" f" read --of=- line72, for the word "closed" read --correct'- page 7,-

9 first column, line 51, for "ambler" read -amber-- page 8, first column,

line 15, claimll, strike out "contacts for? and insert the same after "of" in line 114,, sameclaim; line 51, claim5, for "circuit" read ---circuits--;

and that the-said Letters Patent should be readwith this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 15th day of May. A. D. 1914.1.

' Henry Van Arsdale, (Seal) Acting Comissioner of Patents.

Patent No. 2,256,298;-

CERTIFICATE or CORRECTION.

Q March 25, 191a.

V v RALPH A REID. v V It is hereby certified. that" error appears in the printed sfiecification of the above numbered patent requiring correction as follows: Page 5, first column, line 69 for'theme'ference numeral "779" read -70--; page 5, first,

column, line 55, after -"shelf." insert the following paragraph The terminals ll'Y on the board 115 are arranged in two rows along the opposite sides of the board, each row extending over and above the channel surface 115 and engaging the two rows of terminal strips ll9and 121 projecting down from the block 95.

page 6, first column, line 51; for "disbes" read'--discs-; line 59, for

line T2, for the word "closed" read -correct'-; page 7,

first column, line 51, for "ambler." read -amber--; page 8, first column, line 15, claiml strike out "contacts for" and insert the same after "of" in line 111., same-claim;' line '51, claim 5, for "circuit" read --circuits--;'

and that thesaid Letters Patent should be read with this correction there-in that the same may conform to the record of, the case in the Patent Office.

Signed and sealed this 15th da of May, A. D. 1914.1 7

v Henry Van Arsdale, (Seal) Acting Commissioner of Patents.

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