US2854547A - Flashing relays - Google Patents

Description

Sept. 30, 1958 R. J. LITTLE 2,854,547

FLASHING RELAYS Filed Aug. 30, 1954 4 Sheets-Sheet 1 FIG.|.

LCI

F|G.4. 72 75 77 e9 IN V EN TOR.

HIS ATTORNEY Sept. 30, 1958 R. J. LITTLE 2,854,547

- FLASHING RELAYS Filed Aug. 30, 1954 4 Sheets-Sheet 2 :p/ta INVENTOR. s 3

R.J.L|TTLE HIS ATTORNEY Sept. 30, 1958 R. J. LITTLE FLASHING RELAYS 4 Sheets-Sheet 3 Filed Aug. 30, 1954 INVENTOR.

R.J.L|TTLE HIS ATTORNEY Sept. 30, 1958 R. J. LITTLE 2,854,547

- FLASHING RELAYS Filed Aug. 30, 1954 4 Sheets-Sheet 4 FIGS.

47 LCI FIG/9.

IN VEN TOR.

HIS ATTORNEY United States .1: tent FLASHTNG RELAYS Robert J. Little, Rochester, N. Y., assignor to General Railway Signal Company, Rochester, N. Y.

Application August 30, 1954, Serial No. 453,001

9 Claims. (Cl. Nil-93) This invention relates to direct current relays of the oscillating armature type particularly adapted to flash signal lights at a railroad highway crossing upon the approach of a train. It more particularly pertains to the correlation of a novel contact structure with a pivoted armature in such a way that suitable timing of the relay armature operation and the flashing of the signal lights is accomplished in a positive and safe manner in accordance with rigid safety requirements.

A primary object of the invention is the provision of a set of special contacts to permit automatic energization of one or the other of the relay coils for alternate periods of time so long as the main energizing circuit is closed, as for instance, by the presence of a train in the highway crossing track section. These contacts are held closed in one or the other of two positions by means of permanent magnets until movement of the relay armature occurs, at which time the closed contact connection is forceably broken and moved to a reverse contacting position by a snap action movement.

Another object of the invention is the provision of nonbounce type of lamp control contact assemblies wherein two separate contact groups cooperate to center the pivoted armature in the absence of energizing current and yet provide contacts which are closed in such center positions with normal contact pressures. This provides positive control of the associated warning lamps even though the relay should fail to operate.

Further objects, purposes and characteristic features of the invention will be apparent as the description progresses and by reference to the accompanying drawings.

In describing the invention in detail, reference will be made to the accompanying drawings, in which like parts are referred to by like reference characters, and in which:

Fig. 1 is a front elevation view of a flashing relay constructed in accordance with the present invention;

Fig. 2 is a side elevation view partly in section showing relay structure and the lamp control contacts;

Fig. 3 is an enlarged side elevation view of the special coil control contacts;

Fig. 4 is a sectional view taken on the line 44 of Fig. 3 showing the movable contact of the coil control contacts;

Fig. 5 is a sectional view taken on the line 5--5 of Fig. 3 showing a stationary contact of the coil control contacts which each carry a permanent magnet;

Fig. 6 is a sectional view taken on the line 66 of Fig. 3 showing the means of mounting the pusher on the biasing springs of the coil control contact structure;

Fig. 7 is a perspective view of the relay core structure shown in Figs. 1 and 2;

Fig. 8 is a diagrammatic view shown more for the purpose of illustrating the operation of the relay; and

Fig. 9 is an enlarged sectional view of the armature stop screw.

Referring now more particularly to Figs. 1, 2, 3 and 7,

the usual back plate or base 11 of the relay is constructed of molded insulating material. This back plate 11 acts as a mounting for the relay and also supports the various relay elements, such as the contact structures LCl, LCZ and CC, the cores 12, 13 and 14, and the rear bearing pin 15 for the contact operating shaft 16. These cores 1'2, 13 and 14 are magnetically tied together by a back yoke 17 which is inserted between the ends of the cores and the relay back plate. Large screws 18, one for each core, are passed through the back plate 11 and the yoke 31'? and threaded into the cores 12, 13 and 14. The screws 18 are drawn up tightly to provide a rigid support for the cores 12, 13 and 14 and also to provide a proper magnetic connection between the cores 12, 13 and 14 and the back yoke 17.

The cores 12, 13 and 14 are each provided with an enlarged pole shoe, such as 19, 20 and 21. These pole shoes are properly positioned with respect to the armature 22 and held in place by a non-magnetic face plate 23 which is fastened to the pole shoes 19 and 20 by rivets 24 and the pole shoe 21 by screws 25. The armature 22 is adapted to oscillate back and forth between the pole shoes 19 and 20 and is suspended from, and fastened to, the shaft 16. This shaft 16 is mounted to oscillate on two pinion type bearings, the rear bearing 15 being located in the relay back plate 11 and the front bearing 26 being located in a bracket 27 which is mounted on the front of face plate 23 by means of screws 28. These pinion type bearings 15 and 26 are screw threaded and are adjustably mounted and held in position by lock nuts 29.

As it can be seen with reference to Fig. 1, the pole shoes 19, 2t) and 21 are so positioned that the armature 22 in its neutral position will hang directly above pole shoe 21 and between the pole shoes 19 and 20, leaving an air-gap on either side. The amount of the air-gap on either side is preset and maintained by means of adjustable stop screws Stl. The bottom face of the armature 22 and the top face of the lower pole shoe 21 are arcuate in shape to correspond to the swing of the armature 22, the air-gap therebetween being predetermined and non-adjustable.

The lower head part of the armature 22 is provided with a cored hole 31 in its center to reduce the size of the mass and provide a more direct path for the passage of fiux therethrough. The core 14 is provided with a cylindrical copper slug 32 to retard the flow of flux therethro-ugh for reasons explained hereinafter. The cores 12 and 13 are provided with the usual energizing windings or coils, such as 33 and 34.

As previously mentioned, the armature 22 hangs in a vertical position and is fastened to a horizontal shaft 16, as by a pin 35, so as to swing between the two pole shoes 19 and 20. Fastened to the shaft 16 in a horizontal plane and at right angles to the shaft 16, is a contact operating arm 36. This is conveniently done by passing the arm 36 through a hole in the shaft 16 and welding the two parts together. This provides a contact operating arm which reflects the movement of the armature 22 and this movement is transmitted to the pushers 37, 3S and 39 of their respective contact groups LCl, LCZ and CC. The pushers 37 and 38 are biased toward the flat ends 40 of the operating arm 36; whereas, the pusher 39 is connected to it, so that they are all in a position to be operated by the arm 36 as will be fully explained hereinafter.

As referred to above, the air-gap on either side of the armature 22 between the pole shoes 19 and 20 is adjustable by means of a stop screw 30. When the armature 22 is attracted to one of the pole shoes, either 19 or 20, the tip of the stop screw 30 will come in contact with a non-magnetic hardened metal residual pin 111 located in armature 22. In order to reduce the shock and damage to these metal parts caused by the consistent pounding and still maintain a fixed air-gap, the tips of the stop screws are provided with an insert 112 made of Formica or such other materials as Phenolic, etc.

The insert 112 (see Fig. 9) is made with a reduced portion on its contact tip, thus forming a shoulder as at 113. The stop bolt 30 is provided with a bored hole having a reduced portion 114, thus forming a shoulder as at 115. When the insert 112 is placed in the hole in the stop bolt 30, its bottom enlarged portion will rest against the shoulder 115. The end of the stop bolt 3 is then spun over the shoulder 113 as shown, to hold the insert 112 in place.

When assembled, there is just enough clearance around the insert 112 to form a loose fit. This creates a socalled air pocket behind the insert 112 in the innermost reduced portion 114- of the hole in the stop bolt 3th When the insert part 112 of the stop bolt 30 is struck by the residual pin 111 of the armature 22 upon movement of said armature, the combination of the air pocket and the resiliency of the insert 112 combine to absorb the impact of the armature 22. After adjustment of the air-gap, the stop screw 30 is locked in place by a nut 116.

Referring now more particularly to the detail construction of the contact group assemblies, the lamp control groups LCl and LCZ are each comprised of a molded insulation block 41 having the contact fingers and biasing springs molded therein during manufacture. The two biasing spring 42 and 43 extend outwardly at right angles from the supporting block 4-1 and carry the contact operating pusher, such as 37 or 38. The pusher 3a is mounted on hearing pins 45 and held in place by clips 46. These bearing pins 45 and clips 46 are situated in a slot 47 formed in the biasing springs 42 and 43, similar to the manner shown in Fig. 6 in connection with the mounting of pusher 39. The pusher 33 passes within the slot 47, the clips 46 maintaining the pusher 33 in position after it has been moved forward to rest upon the bearing pins 45.

Each of the contact assemblies LCl and LC2 has a complement of two contact groups, the upper group comprising a movable front contact finger 47, an intermediate stationary contact finger 43 and a movable back contact finger 49. Likewise, the lower group comprises similar contact fingers t), 51 and 52. The pusher 38 is pro vided with four slots to form shoulders 53, 54, 55 and 56, these shoulders cooperating with the contact fingers 47, 49, 50 and 52 as the pusher 38 assumes different positions. During assembly, the contact fingers 47 and 49 are biased to bear against the stationary contact-finger 48 and the contact fingers 5t and 52 are biased to bear against the stationary contact finger 51. Also the biasing springs 42 and 43 are adjusted to hold the bottom biasing spring against a stop retaining arm 57, in which position the bottom of the pusher 38 will be located ator very near a contacting point with the fiat portion 40 of the contact operating arm as, the shoulder 54 will be bearing against the contact finger 49 and the shoulder 56 will be hearing against the contact finger 5'2.

It should be noted at this point that the downward pressure exerted by the biasing springs 52 and 43 must be great enough to overcome the bias of contact springs 49 and 52 as well as hold the pusher 38 down in position next to the fiat portion 40 of the contact operating arm 36. It is believed that with reference to the drawings and the description already given, it can be seen that the relay armature 22 will be normally biased to its center position by reason of its own weight and due to the fact that the push'ers 37 and 38 of the contact groups LCD. and LC2 are bearing against the flat portions 4ft of the cor.- tact operating arm 36, one on either side of center. Upon movement of the armature 22 to the right or left, the contact operating arm will raise either one or the other of the pushers 37 or 38, causing the shoulders 55 and 55 to bear against the front contact fingers 4'7 and Stl, thus breaking contact with the stationary contact fingers 43 and 51. With the pushers 37 or 38 in their upper positions, shoulders 54 and 56 will be moved away from contact fingers 49 and 52, allowing them to assume their biased positions against stationary contacts 48 and 51. In other words, the function of the pusher is to force a break in a given pair of contacts which are normally made by reason of their own bias.

The coil control contact group assembly CC comprises the usual molded insulation block 60 having contact fingers and pusher supporting springs molded therein in the usual way. The pusher supporting springs 61 and as are made of a thin metal resilient material and are cut out as shown at 63 to further increase their flexibility. The pusher 3% is hung and supported at the outer ends of these springs 61 and 62 by the usual bearing pin 45 and clip 4-6 as explained in connection with the lamp control contact assemblies LC1 and LC2. The bottom end of the pusher is forked as shown at 67 to fit over the fiat portion 40 of the contact operating arm 36 so that the pusher 39 will operate up and down in correspondence with the back and forth movement of the armature 22.

The contact group comprises a front stationary contact finger as, a movable contact finger as and a back stationary contact finger 70. The movable contact finger 69 is provided with two spaced resilient metal tips '72 and 3; and two iron washers 75 and 76, one of each on either side. A large rivet 77 of suitable contacting material, such as silver, is used to hold the assembly together. This movable contact finger 65 is also cut out as shown at 71 to increase its flexibility. The front contact 68 is pro vided with a permanent magnet PMl preferably of very strong flux, such as Alnico No. 5 or similar quality material. This magnet PMl is held to the contact finger 68 by means of a bolt and nut 78, the head of the bolt having a piece of silver 79 attached thereto. Similarly, the back contact 70 i provided with a permanent magnet PMZ which is held in place by a nut and bolt 80 which has a silver contact 81 attached to its head.

These permanent magnets PM1 and PM2 are recessed as shown at 74 to receive the full width of their respective contact fingers 68 and '76 so that when bolted together, the permanent magnets are prevented from turning. Also, each permanent magnet PMl and PMZ is provided with a transverse groove 53 in its face portion to definitely establish opposite poles and facilitate the flow of flux therethrough. A counterbore 59 allows the heads of the bolts '78 and 80 to be countersunk below the face surface of the magnets.

The pusher 39 is recessed to form two shoulders 82 and 83 as shown. The resilient tips 72 and 73 of contact finger 69 extend into this recess and are so positioned that a downward movement of the pusher 3-9 will cause the shoulder 82 to contact the tip '72 and an upward movement of the pusher 35" (assuming the contact 65 to be in its back contact position) willcause the shoulder 33 to contact the tip 73.

It should be noted that the bolts 78 and 8t and the rivet 77 not only serve to hold the various parts together but also serve as conductors for the electrical current through the contacts and provide an air-gap means to prevent the permanent magnets of contacts 68 and 76) from coming into actual contact with the iron washers of contact 69. As a matter of convenience for plug coupling purpor' .52. the various contact fingers above mentioned all extend through their supporting blocks and are shaped as shown at 84 and 85 to facilitate the reception of plug connector in the usual way.

With particular reference to'Fig. 3, the position of movable contact finger 69 shown in contact with stationary contact finger 62 is assumed to be the last operated po ition of the relay, it being understood that either the front or the back contact is always closed in the normal deenergized position of the relay. In this position, the next movement of movable contact 69 would occur when the pusher 39 is moved downward.

Assuming now that coil 33 on the left was to become energized, relay armature 22 would move to the left and the right hand end of contact operating arm 36 would pull the pusher 39 downward. As the movement of the pusher 39 starts downward, the shoulder 82 will bear against the resilient tip 72 and tend to force contact finger 69 downward. However, the magnetic pull between permanent magnet PMl and iron washer 75 is of such strength that it would hold contacts 68 and 69 in a closed position until such a time as the pusher 39 builds up enough pressure against the resilient tip 72 to overcome this magnetic pull. The factors are so chosen and the parts so proportioned that the contact breaking point comes at a time when the resilient tip 72 is bent down until it is just short of touching the main contact finger 69. The built up pressure in the combination tip 72 and finger 69 will then break the hold of the permanent magnet PM1 and the contact finger 69 will start moving downward. As the iron washer 75 starts to leave the magnetic field the permanent magnet PMl, the trapped pressure in the resilient contact tip 72 will show its effect and snap the contact 69 towards the back contact finger '70. As the movable contact finger 69 passes its mid-position, the iron washer 76 will come into the magnetic field of permanent magnet PM2 and the magnetic pull of this magnet will complete the snap action movement of movable contact finger 69 and cause it to make connection with its back contact member 70 through the rivet 77 and bolt 80. Upon a reverse movement of the armature 22 which would cause an upward movement of the pusher 39, the shoulder 83 would contact the resilient tip 73 shortly after the armature 22 passes through its mid-position and movable contact finger 69 would be moved back to its front contact position in a manner similar to that described above.

Referring now more particularly to Fig. 8, there has been shown a simplified operating circuit in connection with a diagrammatic showing of the operating parts of the relay, such as the core structure, the armature 22, contact operating arm 36, the two lamp control contact assemblies LC1 and LC2 and the coil control contact assembly CC.

It is assumed that the line control relay XR is energized because of the absence of a train in the usual highway crossing track section, thus all energy is cut off from the flashing relay and its associated lamp control and coil control contact LC1, LC2 and CC. The relay armature 22 is now biased to its center position by reason of the biased pushers 37 and 38 as previously explained. With the relay armature 22 in its center position, the

front contacts 47 of the lamp control contact groups LCl and LC2 are biased to a closed position and the movable contact 69 of the coil control contact group CC is held closed against the front contact 68 by the magnetic pull of the permanent magnet PM1, since this happens to be the last operated position of this contact group CC.

Upon entrance of a train into the usual highway cross ing control section (not shown), relay XR is deenergized, causing its back contacts 86, 87 and 88 to be closed. With contact 88 in its back position, a circuit is established to light the lamp E1, which is assumed to be one of the flashing lamps to warn highway trafirc approaching a railroad crossing from an easterly direction. This circuit may be traced from the side of a source of current to the contact 88, wires 89 and 90, contact fingers 4-7 and 48 of the lamp control contact group LC1, wire 91, filament of the lamp E1 and through a suitable voltage limiting resistor to the side of the source of current. Similarly, with the contact 87 in its back position, the westbound highway trafiic warning lamp W1 is lighted by a closed circuit traced from to the con- 6 tact 87, wires 92 and 93 to contact fingers 47 and 48 of the lamp control contact group LC2, wire 94, filament of the lamp W1 etc. to

Also, with contact 86 of the control relay XR in its back position, an energizing circuit for the flashing relay is established. As previously mentioned, movable contact finger 69 of the coil control contact group CC always remains in one or the other of its closed positions after the flashing relay has ceased functioning after its last operation. It has been assumed tht it has stopped in its front contact position in contact with stationary contact finger 68, and is held there by the permanent magnet PMl. With the coil control movable contact 69 in this position, the energizing circuit will supply current to the winding 33 through a circuit which may be traced from the side of battery B, wire 95, back contact 86 of relay XR, wires 96 and 97, winding 33 on the core 12, wires 98 and 99, contacts 69 and 68 of the coil control contact group CC, wires 100 and 101 back to the negative side of the battery B.

With winding 33 energized, flux will begin to flow in the direction of the dotted arrows A1 through the core 12, yoke 17, core 13, pole shoe 21, armature 22, pole shoe 19 and back to core 12. As previously mentioned, core 13 is provided with a short circuited winding or copper slug 32 so that the building up of flux in the magnetic structure just described is retarded for a short interval of time. When suflicient flux is built up in this magnetic circuit the armature 22 will be attracted to the pole shoe 19, an air-gap being maintained by reason of the residual screw or pin 30.

Upon movement of the armature 22 to the left towards pole shoe 19, the shaft 16 and its associated contact operating arm 36 will turn in a clockwise direction, causing the left-hand portion of arm 36 to rise and the right-hand portion of arm 36 to drop. The upward movement of this left hand portion of arm 36 will force the pusher 37 upward, causing contact finger 47 to break with contact finger 48 and allowing contact finger 49 to make with contact finger 48 due to its own bias. When this happens, flashing lamp E1 will be extinguishe. and flashing lamp E2 will be lighted by a circuit traced as follows: from to back contact 88 of relay XR, wires 89 and 102, filament of the lamp E2, wire 91, contacts 48 and 49 of the lamp control contact group LC1, wire 183 and. through the voltage limitin resistor to At the same time the left hand portion of contact operating arm 36 moves upward, it is obvious that the right hand portion will move downward. This downward movement of the right hand portion of the arm 36 does not disturb the pusher 38 of the lamp control contact group LC2 as the biasing spring 43 is against the stop 57 and consequently, no movement of the pusher 38 can take place as the arm 36 moves away from it. As a result, the flashing lamp W1 will remain lighted during this interval so that a warning light will be displayed facing the highway trafiic approaching from both directions. However, this downward movement of the right hand portion of the arm 36 will move the pusher 39 of the coil control contact group CC downward and in so doing the pusher 39 will force a break between contact fingers 69 and 68 and allow a contact to be made between contact fingers 69 and 70 as previously described, the permanent magnet PM2 attracting and holding the iron washer 76 of contact finger 69.

When this change takes place, a new circuit is established and the energizing current for winding 33 is cut off, and transferred to the winding 34 on the right hand core 14. This circuit may be traced as follows: from the side of battery B, wire 95, back contact 86 of relay XR, wires 96 and 104, contact fingers 70 and 69 of the coil control contact group CC, wires 99 and 105, winding 34 on the core 14 and wires 106 and 101 back to the side of the battery B. Upon deenergization of the winding 33, the armature 22 does not immediately swing to its vertical center position even though the bias of pusher 37 tends to make it do so. This is because the highpercentage of flux built up in the magnetic field including the core 12, and previously described, will take a larger interval of time to decay than would be the case if the copper slug 32 were not present. While this flux decay in the core 12 is taking place, with the winding 34 now energized the flux will be building up in a new magnetic field including the core 14, pole shoe 20, armature 22, pole shoe 21, core 13 and yoke 17, as indicated by the dotted arrows A2.

As the flux continues to decay in core 12 and build up in core 14 until such a time as they are about equal, the downward bias of pusher 37 of the lamp control contact group LCll against the arm 36 will begin to prevail and the armature 22 will begin to move to its center vertical position. At this stage of the operation the pusher 37 will have forced the contact finger to make contact with contact finger 8, due to its own bias. This change will now extinguish flashing lamp E2 and again light flashing lamp Eli through a circuit which has been previously traced, thus completing a flashing cycle between the lamps E1 and E2.

As the armature 22 moves toward its center vertical position, the fiux in the new magnetic path including core 14 will have increased sufiicient enough to attract the armature 22 to the pole shoe 20, thereby turning the shaft 16 and the contact operating arm 36 in a counterclockwise position. In this position, the left hand portion of arm 36 will move downward and the right hand portion will move upward. The downward movement of the left hand portion of the arm as will not effect the pusher 37 of the lamp control contact group LCll and the lamp Ell will remain lighted. However, the upward movement of the right hand portion of the arm 36 will raise both pushers 33 and 39. The upward movement of pusher 38 of the lamp control contact group LCZ will cause contact finger 47 to break from contact finger 48 and allow contact finger 49 to make contact with contact finger 48 in a manner similar to that described in connection with the operation of lamp control contact group LCl. In this position, lamp W1 will be extinguished and lamp W2 will be lighted, the new circuit cutting off energy to lamp W1 and transferring it to lamp W2 as follows: from to back contact 87, wires 92 and 107, filament of lamp W2, wire 94, contact fingers 48 and 49, Wire 1% to the voltage limiting resistor and Here again, there will be at least one warning light, either E1 or W2, displayed to highway trafiic approaching the.railroad crossing from either direction.

At the same time pusher 38 moves upward, pusher 39 will also move upward, and cause a break between con tact fingers 69 and 7t and make contact between contact fingers 69 and 63, thus establishing the original circuit previously described. It will now be obvious that the energizing current is cut oif from winding 34 and again transferred over'to winding 33. Thus, the building up of flux in core 1'2. and the decaying of flux in core 14 must take place before another shift of the relay armature 22 occurs, the same procedure taking place as previously described in connection with a counterclockwise movement of the armature 22.

From the foregoing description and with reference to the drawings, it will be understood that once energy is supplied to the flashing relay, as for example as illustrated by the dropping of relay XR due to the presence of a train in the highway crossing track section associated with the highway crossing, the flashing relay armature 22 will continue to reverse its direction of movement at certain spaced time intervals and thereby cause a flashing of the lamps Ell-E2 and Wit-W2; until such a time as the tran proceeds out of the highway crossing track section, whereupon the relay XR will become energized cut off current to the flashing relay. The spaced time interval recommended in accordance with accepted standards is about 45 to 50 times per minute and the values of the windings 33 and 34 and the copper slug 32 as well as the contact finger adjustments are so chosen that the correct results are obtained.

For instance, it will be noted that the space between the end of contact finger 47 and the shoulder 53 of the pusher 38 of the lamp control contact group LCl must of necessity be smaller than the distance between the contact surfaces of contact finger 4-9 when in a position as snown in Fig. 2, because contact fingers 47 and 48 we ole rly broken before contact fingers 48 and 49 are made. This prevents a complete shorting of both lamps but does create a short dark interval between the extinguishing of one lamp and the lighting of the other lamp, thus providing a flashing effect of the lamps with either one or the other of the lamps lighted up during most of the time interval between changes.

Also, the fact that both of the contact fingers 47 and 49 are biased to a closed position with respect to stationary contact 4-8 guarantees that either one or the other of the lamps will light up during the presence of a train into the highway crossing control track section, because the pusher 37 can only hold one contact open at a time, either one or the other remaining closed dependent upon the position of the relay armature 22. Consequently, if the flashing relay armature 23 failed to operate from its center position or became stuck in either extreme operated position for some reason or other, there would always be at least one flashing lamp lighted steadily to warn approaching highway traffic. Furthermore, if any one of the contact fingers 47, 43 or 49 should accidentally be broken or burned out, or fail to conduct current for any other reason, the two sets of lamps E1E2 and W1WZ would become coupled up in series circuits and each would light up to show a somewhat dimmer light, but still act as a warning to approaching highway traffic.

It should also be noted that the bias of the pusher 37 to a downward position by reason of biasing springs 42 and 43 must be sufiicient to overcome the bias of contact fingers 49 and 52 as well as return the armature 22 to its center position, the stop arm 57 preventing any further downward movement of the pusher 37. The same is true with respect to the lamp control contact group LCZ.

As previously mentioned, the coil control contact group CC has its pusher 39 interlocked with the contact operating arm 36 so that movement of the armature 22 in either direction will affect the movement of the movable contact finger 69. In the position shown in enlarged Fig. 3, it is assumed that the armature 22 has just operated the pusher 39 and its associated movable contact 69 to an upward position and the armature 22 has returned to its center position and is now in position to move the pusher 39 and the contact 69 to a downward position.

it will be noted that there is a small gap between the upper shoulder 82 of the pusher 39 and the resilient tip 72 of Contact finger 63 and a much larger gap between the lower shoulder 83 and the resilient contact tip 73. in this position, it will be obvious that the lower gap must be larger because it must equal the space of the upper gap plus the distance the pusher 39' will move downward on its next operation. After the pusher 39 has moved downward in response to the next operation of the armature 22, the operated contact finger 69 will position itself so that the small gap will be between contact tip 73; and shoulder whereas the large gap will be between contact tip 72 and shoulder 82. It stands to reason that the airgap between the movable contact finger 69 and stationary contact finger 70, as an example, must be so proportioned so that when the pusher 39 is moved downward as just described above, the permanent magnet P112 will hold the silver rivet head 7 tightly against the silver tip 81 on the head of bolt 83, leaving a slight airgap between the permanent magnet PMZ and the iron washer 76 and also leaving a slight airgap between the contact tip 73 and the shoulder 83.

As previously described, i-pon movement of the pusher 39 to a downward position from its position as shown in Fig. 3, the shoulder 82, would bear against the resilient contact tip 72, thereby forcing it downward against the pull of the permanent magnet PMl. Under ordinary circumstances, the downward force being built up in the contact tip 72 and its associated contact finger 69 while the pusher 39 is moving downward would be sufficient to overcome the pull of the permanent magnet El /ill at a point just before the contact tip 72 reaches the extreme end of the movable contact finger 69, thus causing operation of the movable contact to its back position wherein it contacts stationary contact 7%. However, in the event that contact fingers 68 and 69 become stuck together, such as by the arcing and burning of its silver contact elements 77 and 79, there is still enough armature movement left so that the further movement downward of the pusher 39 would cause contact tip 72 to actually bear against the extreme end of the movable contact finger 69 and force a break between the contacting elements 77 and '79.

With reference again to Fig. 8, it will be seen that the coil control circuit has been provided with the usual resistance Ml? and condenser 110 which is wired across one of the coil windings, such as 33, to minimize the arcing across the above mentioned contact elements, such as '77 and 79 or 77 and 81. This incidentally also minimizes the interference which is caused by the arcing and transmitted to radio receivers which may be located in the immediate vicinity of the highway crossing.

It is believed that the invention shown and disclosed herein presents a new and novel way of providing flashing highway crossing signal lights which afiord better protection and safety. It should also be understood that the self-closing biased type of non-bounce contacts provided for the lamp controls are more durable and capable of handling higher voltages without contact arcing and burning. Also, the coil control contact structure provides a positive quick snap action control whereby energy is transferred from one coil winding to the other in a minimum of time even though the relay core structure is purposely constructed to make it slow acting to provide proper time intervals between reversal of armature operations.

It is also desired to be understood that even though these novel contact structures are particularly desirable in a flashing relay of the type shown and described, they could be very easily adapted for use in other types of relays and circuit controlling devices.

Having shown and described one form of the invention, it should be understood that various adaptations and deviations in the structures could be made without departing from the spirit of the invention or the scope of the appending claims.

What I claim is:

1. In a relay organization, an electromagnetic core structure with a cooperating armature operable to either of two extreme positions by selective energization of windings on said core structure, spring means acting to normally bias said armature to a mid-position, two fixed contact fingers, a pair of movable contact fingers associated with each of said fixed contact fingers, the fingers of each pair being located on opposite sides of such fixed contact finger and biased toward it, a contact operator for each pair of said movable contact fingers and which is operably connected to said armature, each such contact operator acting to hold said movable fingers of its pair at spaced points away from each other and each away from its respective fixed contact for one extreme position or the other of said armature but allowing one of said movable contact fingers of each pair to make contact with its respective fixed contact While said armature is in a mid-position and one of its extreme positions.

2. In a relay organization, a contact block of insulating material, a relatively rigid contact finger mounted on said block, two relatitaaly flexible movable contact fingers mounted on said contact block on opposite sides f said fixed contact finger and biased toward it with a predetermined pressure, a contact operator of insulating material, two spring supports for said contact operator mounted on said contact block for permitting limited movement of said contact operator in a particular plane, said contact operator having a spacer portion located iding portions of said two movable contact fingers to hold them away from each other for a distance slightly greater than the thickness of said fixed contact finger located between them, said spring supports having a permanent deformation causing them to bias said contact operator in a particular direction causing its spacer portion to hold one of said movable contact fingers away from said fixed contact finger but allowing the other of said movable contact fingers to rest against said movable contact finger wholly free of any connection with said contact operator, a stop member for limiting the movement in said particular plane of said contact operator by the bias of its supporting springs, and electromag netic means efiective when energized for moving said contact operator in a direction opposite to its bias for permitting the opposite movable contact finger to make contact with said fixed contact finger in accordance with its bias independently of any connection wtih said operator but causing said spacer portion to move said one movable contact finger away from said fixed contact finger.

3. in a relay organization, two contact structures, each comprising a block of insulating material, a relatively rigid contact finger mounted on said block, two relatively flexible movable contact fingers mounted on said contact block on opposite sides of said fixed contact finger and biased toward it with a predetermined pressure, a contact operator of insulating material, two spring supports for said contact operator mounted on said contact block for permitting limited movement of said contact operator in a particular plane, said contact operator having a spacer portion located between extending portions of said two movable contact fingers to hold them away from each other for a distance slightly greater than the thickness of said fixed contact finger located between them, said spring supports having a permanent deformation causing them to bias said contact operator in a particular direction causing its spacer portion to hold one of said movable contact fingers away from said fixed contact finger but allowing the other of said movable contact fingers to rest against said movable contact finger wholly free of any connection with said contact operator, a stop member for limiting the movement in said particular plane of said contact operator by the bias of its supporting springs; electromagnetic means having a pivoted armature operable to either of two extreme positions but cooperating with said contact operators in a manner to be normally biased by them to a mid-position, said armature acting when operated toward either extreme position to actuate one of said contact operators, whereby a movable contact finger of each pair is normally making contact with its respective fixed contact finger While said armature is in a mid-position.

4. A circuit controlling contact mechanism comprising, a block of insulating material, a relatively rigid contact finger mounted on said block, two relatively fiexible movable contact fingers mounted on said block and positioned one on each side of said rigid contact finger, a contact operator of insulating material, two spring supports for said contact operator each mounted on said block, a stop member mounted on said block for limiting the movement of said spring supports and said contact operator in one direction, said two relatively flexible movable contact fingers being biased toward said relatively rigid contact finger with a predetermined pressure, said two spring ill supports and said contact operator being biased toward said stop member with a predetermined pressure, said spring support bias being greater than said movable contact finger bias, said contact operator having a spacer portion located between the free end portions of said two relatively flexible movable contact fingers, said spacer portion having a length greater than the thickness of said relatively rigid contact finger to prevent both of said two relatively flexible movable contacts from contacting said relatively rigid contact finger at the same time, whereby an applied force against said contact operator in a direction reverse to said spring support bias will first move the normally closed flexible contact away from said rigid contact finger and next allow the normally open flexible contact finger to bias itself closed against said rigid contact finger, whereupon removal of said applied force will allow the bias of said spring supports to return said contact operator and said two flexible contact fingers to their normal position.

5. In a clay organization, an electromagnetic core structure having a cooperating pivoted armature operable from a normal mid-position to either of two extreme positions by selective energization of windings on said core structure, said armature being limited in movement to its two extreme positions and having means attached thereto for transmitting its movement to a contact operator, said contact operator being suspended on two spring fingers and having a notch therein forming two shoulders, two spaced rigid contact fingers each having a permanent magnet mounted thereon in a manner to face each other, a movable contact finger positioned between said two rigid contact fingers and having a magnetic disc mounted on each side thereof to cooperate with said two permanent magnets, said movable contact finger having two resilient fingers mounted on its opposite sides at its free end which resilient fingers cooperate with said two shoulders on said contact operator but are limited in their bending by said movable contact finger, whereby a movement of said armature in a given direction away from its midposition will cause said contact operator to force a magnetic break between said movable contact finger and one of said rigid contact fingers and allow said movable contact finger to make a magnetic connection with said other rigid contact finger, said contact fingers having contact elements thereon which cooperate with each other.

6. In combination a contact block having two fixed contact fingers mounted thereon at spaced locations, a movable contact finger located between said two fixed contact fingers and carrying a small circular magnetic disc on each side thereof, said movable contact finger having a free end extending beyond said metal discs and having a spring member on each side of such free end also extending at a slight angle to a length substantially correspondin with the free end of said movable contact finger, ttvo small circular permanent magnets each mounted on its respective one of said two fixed contact fingers for cooperatin with said discs mounted on said movable contact finger, a contact operator of insulating material having a slotted portion into which the three extending portions of said movable contact finger may be inserted, said slot being greater than the distance between the ends of said springs on said movable contact finger but effective when moved in one direction to cause said magnetic discs to be drawn away from the permanent magnet on the xed contact finger on its side only when such spring has lcen rf pressed to the extent that sufficient trapped pressure is present to overcome the magnetic pull of said permanent magnet, whereby said movable contact finger is quickly snapped to the opposite position when it has been moved to a point beyond the central position between said two fixed permanent magnets, in which opposite position it is held by said other permanent magnet.

7. A circuit controlling contact mechanism for operation by a push-puil movement comprising, a block of insulating material, two rigid contact fingers mounted on said block, a flexible movable contact finger mounted on said block and positioned between said two rigid contact fingers, two flexible spring supports mounted on said block, a contact operator mounted on and positioned between the free ends of said two spring supports, said flexible movable contact finger having a spaced resilient spring finger on each side of its free end and a magnetic disc on each side near its center portion and a rivet of suitable contact material for holding together said flexible movable contact finger, said resilient spring fingers and said magnetic discs; said two rigid contact fingers each having a small round permanent magnet fastened thereto by means of a bolt of suitable contact material, said permanent magnets being located so as to face and co-act with its respective magnetic disc on said flexible movable contact finger, said contact operator having a slotted portion which confines the free ends of said flexible movable contact finger and its associated resilient spring fingers, said slotted portion of said contact operator having a width slightly greater than the span of said spaced resilient spring fingers lus the length of said contact operator travel during a movement from its center position to an extreme position; whereby a movement of said contact operator in a direction opposite to its last operated position will cause a shoulder of said slotted portion to compress its co-acting said resilient spring finger until sutflcient trapped pressure is available to overcome the magnetic pull of its associated said permanent magnet, whereupon said flexible movable contact finger will break connection with one of said rigid contact fingers and by a spring type snap action will be forced into a contacting position with the other of said rigid contact fingers, the magnetic pull of said other permanent magnet holding said flexible movable contact finger in a contacting position against said other rigid contact finger until a reverse movement of said contact operator is started and proceeds beyond its center position.

8. In a relay organization, an electromagnetic core structure having a back yoke and a plurality of cores fastened thereto, two of said cores having an enlarged pole piece and a winding thereon, a pivoted armature mounted between said two cores and operable to either of two extreme positions, said armature having means associated therewith for opening and closing contact fingers, each of said two cores having an adjustable stop bolt mounted therein and positioned to have one end facing said armature, said armature having two nonmagnetic residual pins mounted therein and positioned so that each will cooperate with a separate one of said stop bolts ends upon alternate movements of said armature, said stop bolt ends having an insert of resilient fibrous material mounted therein in such a manner 11; to rest against a shoulder and form an air pocket in the rear thereof, whereby an impact against said re"- insert will be cushioned by said air pocket and said re ient insert combination.

9. in a relay organiaztion, an electromagnetic structure having a cooperating armature pivotally mounted between two pole shoes and operable eith r of two extreme positions by selective cncrgizaticn of windings on said core structure, an adjustable stop bolt mounted in each of said two pole shoes positioned t; have their ends cooperate with nonmagnetic residual pins in said armature when said arm .rc is in either of its two extreme positions, said stop bolt ends being hollowed out and having an insert of resilient fibrous material mounted therein in such a as to red against a shoulder and form an air pocke the rear thereof, said armature having centrally treated attached thereto for transmitting its movement to u contact operator operably connected to said arm. s id contact operator eing suspended on two spring fingers and having a notch therein forming two shoulders, two spaced rigid contact fingers each having a permanent magnet mounted thereon in a manner to face each other, a movable contact finger positioned between said two rigid contact fingers and having a magnetic disc mounted on each side thereof to cooperate with said two permanent magnets, said movable contact finger having two resilient fingers mounted at its free end thereof which cooperate with said two shoulders on said contact operator, whereby a movement of said armature in a given direction will cause said contact operator to force a magnetic break between said movable contact finger and one of said rigid contact fingers and allow said movable contact finger to make a magnetic connection with said other rigid contact finger, said contact finger having contact elements thereon which cooperate with each other, whereupon the impact of said armature against said stop bolt will be cushioned by said air pocket and said resilient insert combination.

References Cited in the file of this patent UNITED STATES PATENTS Mallett June 12, 1888 Coleman July 5, 1904 Hobbs Feb. 14, 1911 Levison Sept. 14, 1915 Speed Oct. 24, 1916 Leake Apr. 5, 1932 Howe Nov. 1, 1938 Field Nov. 8, 1938 McNairy Dec. 23, 1941 Cox Dec. 24, 1946 Ayers et a1. Jan. 6, 1948 Knapp et al. Oct. 1, 1957 FOREIGN PATENTS Austria Aug. 10, 1915 Switzerland Dec. 16, 1953

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