US2337486A - Selectively operated circuit controlling device - Google Patents

Description

Dec.-21, 1943. A. H. MILLER 2,337,486

SEIJECTIVELY OPERATED CIRCUIT CONTROLLING DEVICE Filed Aug. 29, 1941 Sheets-Sheet 1 FIG! INVENTOR AHMIILLER A T TORNEY Dec. 21, 1943.

'A. H. MILLER SELECTIVELY OPERATED CIRCUIT CONTROLLING DEVICE Filed Aug. 29', 1941 2 Sheets-Sheet 2 INVENTOP EVA. HM/L'LER (9, %%mfl1 A TTORNEY Patented Dec. 21, 1943 nane SELECTIVELY OPERATED CKRCUET CONTROLLING DEVICE Albert H. Miller, Bayside, N. Y., assignor to Bell Telephone Laboratories, Incorporated, New

York, N. Y., a corporation of New York Application August 29, 1941, Serial No. 4%,692

2 Claims.

This invention relates to selectively operated circuit controlling devices of the step-by-step operated type and which are commonly known as selectors,

The object of the invention is to provide im provements in a. device of the type above mentioned to make the device suitable for use in an emergency signaling system.

A feature of the invention resides in a cam provided in the selector to control the operation of an emergency signal device.

In the drawings,

Figs. 1 and 2 are respectively a top View and a side elevational View of the selector with the invention embodied therein.

Fig. 3 is a schematic diagram of a signaling system showing an application of the invention.

Fig. 4 is a diagrammatic illustration of a radio signaling system in which the invention is found useful; and,

Fig. 5 is an enlarged view in perspective of a portion of the wheel of the selector and showing the cam mounted on the wheel and a set of contacts operated by means of the cam.

The selector is found useful in selective sig naling systems comprising a central signaling station and a plurality of substations to be selectively signaled by the central station and provides means for controlling the operation of an emergency signaling device at eachsubstation when an emergency signal for all substations is sent from the central station.

The improved selector may follow the general form of the selector illustrated and described in Joseph C. Field Patent 1,343,256, issued June 15, 1920, and reference may be had to that patent for an understanding of the general form and arrangement of most of the parts and the general manner in which the selector may be operated. To simplify the description and understanding of the invention and not in the sense of limiting the invention to that particular form, it will be assumed that the invention is embodied in a selector of the type shown in the abovementioned patent.

The selector is so constructed and arranged that it may be operated rapidly and accurately in response to alternating current impulses and comprises a polarized electromagnetic driving device; a centrally pivoted armature, a stepping or actuating pawl driven by means of the armature and a wheel operated in an advanced movement by means of the pawl. The wheel carries a wiper contact and is rotated in an advanced movement to carry the wiper contact into engagement with the desired one of a group of fixed contacts, the wheel being advanced one step for each impulse received by the electromagnetic driving device, A return spring is provided in each selector to return the wheel to starting position and releasable holding means are also provided to hold the wheel in various advanced positions against the action of the return spring. I

As shown in the drawings 5-5 designate the windings of the electromagnetic device, ii the centrally pivoted armature which is polarized by means of the permanent magnet l. Attached to the armature 6 is an elongated S-shaped arm ii carrying at its free end a pin 9 and at a point intermedate its ends a pin it, both pins being adapted to engage a pivoted lever 52 carrying at its outer end a stepping pawl :13. The coils ii5 and the cores on which they are wound are supported in a bracket 19 mounted on a base i. Carried by the supporting bracket is is a frame comprising upper and lower members or plates M and i5 fastened together and between which there is a pin it upon which the lever 82 is pivoted in position to move the stepping pawl l3 into engagement with a ratchet wheel i'l mounted on a shaft 18 journaled in the frame members i i and I5. By means of a spring 45 the ratchet wheel I! is normally retained in a position with a pin thereon (not shown) in engagement with a stop member (not shown) but which is supported on the under surface of the plate I i. The stepping pawl I3 is normally held against the stop pin 56 supported on the plate E5, the pawl i3 being normally held in this position by means of a spring 5! which is attached at one end to the pawl l3 and at the other to the pivoted lever i2, an adjustable pin 52 mounted in a projection of the plate i i limiting the forward travel of the pawl l3. By means of a spring 3 secured at one endto the lever l2 and at the other to an arm 36 mounted on the plate t5, the lever i2 is normally held in the position shown in Fig. 1 and with the stepping pawl l3 out of engagement with the ratchet wheel i'i. The pins 9 and Ill engage the pivoted lever it upon opposite sides of the pivot axis or pin Iii and upon opposite faces in such manner that with each movement of the armature ii, in either direction the stepping pawl l3 will cause a one step advance movement of the ratchet wheel ll.

Mounted upon the shaft l 8 carrying the ratchet wheel i? and movable therewith is an apertured wheel 28 carrying a contact spring 53 in the free end of which is a contact 2! adapted to cooperate with a plurality of fixed contacts or, 23 and 25 mounted upon an insulating plate secured to the plate it. Holding pins 28 and 23 carried by the wheel 2d are adapted to cooperate with a holding spring insulatingly mounted on the plate i i. The holding pin is located in a definite position on the wheel 28 while the holding pins 2'? and 23 are made removable so that they may be secured in any of the holes d provided in the rim of the wheel 2t, the location of the holding pins 2'! and 28 depending on the particular code of impulses to which the selector is to be made responsive. The spring 35 normally bears against the insulating knob or roller 3i! carried by the lever l2 and is so tensioned or bowed that in the neutral position of the armature 6 the free end of the spring 3a which is provided with a curved projection extends inside the circumference of a circle described by the holding pins 27. 2S and Ell in the movement of the wheel All. As the armature 5 moves, how ever, in response to current impulses through the w ndings 5-5 of the electromagnets. the movements of t e lever 52 will move the projection 33 outwardly beyond he periphery of the wheel and when. the ratchet wheel ii is moved by means of pawl 13, in accordance with current impulses supplied to the windin s and to a position where one of the p ns 2?, or is opposite the projec ion 38. the selector is deenergized, the spring 35 will move inwa. d -y to bring the pro jection 38 nto en agement with that pin to hold the wheel 25 in the position to which it has been advanced. \A hold ng pawl is prov ded to engage the ratchet wheel ll and prevent dropping back of the ratchet wheel l'l dur the time that the armature t is traveling from one extreme position to the other in response to a change in po-- larity of the energizing current.

The wheel 28 may be stepped around to bring the contact 2i into selective engagement with the fixed contacts 22, 23 and M. Each of these contacts may be in control of a circuit including a bell or other signal device. The selector therefore be operated to selectively control the signaling devices served by the fixed contacts 22, 23 and 26.

In the present invention, the wheel is equipped with a cam of particular form and construction and a pair of normally open contact springs is mounted on the selector to be operated by means of the cam.

Selectors of the general type above described and not having the improvement provided in the present invention are commonly used in selective signaling systems employed in train dispatching. The selectors are located in substations commonly called way stations of the system and may be operated by code impulses sent from a central station, the code impulses being sent by operation of suitable code sending keys or by operation of some other suitable impulse code sending device. When the impulses are sent all selectors connected to the signaling system operate to advance the wheels Ell so that the contacts 2i are moved toward the fixed contacts of the selectors. The impulses are sent in groups with appreciable pause between each group. The s ector havin its holding piins arranged for the code signal sent will be finally advanced to a position where the contact El engages one of the fixed contacts 22, 23 or 2 5. The other selectors will return to normal position during the pauses between the groups of code impulses. By use of the selectors it is therefore possible to selectively control the operation of signaling devices at the way stations.

In the present invention a cam Ht is secured to the upper surface of the Wheel 2-3 in the se- 5 lectc-r a d is rotated by of the wheel 25 engagement with. a knob Ell pro-- e under-surface of a relatively long leaf spring contact 552 of pair of contacts H3. T is i ii? is an inch; e type cam havln an up acting portion lid and a downwardly portion i5 3". The finger portion 5 l 5 siopes downwardly i1 cm the upper end of the portion ii and into engagement with the wheel and is curved to follow the form of the rim of the whee. The lower end of the portion te mhates in an ly disposed aper i a bolt iii which extends 1'3 aperture in the loot portion l i3 and holes 5 in the rim of the it.) is so mounted on the line "'on shown in l and 2 to the dotted line pcsit'on shown in these figures. During this eat, the finger portion H5 is gradually 35 moved in successive ste .s the knob Hi and gradually flexes the relatively long spring finger contact 552 into engagement with the shorter spring contact 68 of the pair of normally open contacts 653. he spring contacts H2 and MS as shown in Fig. 3 may be in a local circuit H9 including a source of current supply i159 and a signal device 52 i.

The contacts M3 are insulatingly supported as shown in Figs. 1 and 2 on an angle bracket 122 which is supported by means of the screws on a downwardly extending side portion of the plate M. The position of the contact springs Eli-l relative to the cam H8 is such that the cam i it will not only cause closing of the contact H2 against the contact H5, but will also cause upward flexing of the contacts 1! l2 and H3 when the high point on the cam i it is brought almost directly under and in engagement with the knob l i l. The wheel 28 has a tendency to rotate back to normal position under action of its return spring 55 between each successive impulse ap plied to the selector. In this brief clockwise movement of the wheel as, the extent of movement is not suilicient to cause opening of the contacts M3 since the cam Hill is not carried out of engagement with the knob l l i and the upward flexure of the contact H3 under the action of the cam l ill has built up sufficient spring tension in the contacts M2 and M3 to hold the contacts in engagement during the slight return movement of the wheel The local circuit H9 will therefore remain closed during this brief period.

The cam lid is made with the long sloping finger portion H5 sloping downwardly in the direction of the forward rotation of the wheel 29 and followin the curvature of the rim of the wheel and is so arranged on the wheel 2E? and relative to the knob ill that when the wheel 2&3 is rotated to bring the cam i iii to the position shown in Fi 5, the contacts H3 will be closed before the cam Hi! reaches its final operated position and that from then on until the cam lit reaches its final operated position, the contacts H3 will be flexed upwardly to accommodate the rising form of the cam. It will be seen therefore that even when the wheel it rotates slightly backward between pulses, and the cam lid, in efiect, slides under the knob i l l, the contacts M3 still remain closed to keep the local circuit H9 closed and the bell liii still operating. If the cam i it were not made with the relatively long sloping finger portion i555 and the contacts lit were not flexed by the cam lit, the contacts H3 might open on a slight return movement of the wheel 28 and the local circuit lit would be opened and the bell signal l2i would stop rin ing until the cam closed the contacts lit again. The selector embodying this invention may be used as shown in Fig. 3 in the selective signaling system. In this figure iii and "ii designate line wires extending from a central transmitting or dispatchers station A to a plurality of receiving or way stations B and C. At each way station there is a selector '52, the windings 5-55 of which are connected in bridge or the line wires and in series with a condenser l t and two impedance coils iii-"l5. Each way station also equipped with a signaling bell l5 under control of the selector thereat and a telephone set ll included in a normally open bridge of the line A single battery '53 in each Way station may serve for operating the signal hell it and for furnishing current for talking purposes. At each way station there may be additiona signaling devices such as 19 and which may be exactly like the signaling bell l6 controlled by the selector and operated from the local battery it.

At the transmitting station A there is a main battery 55 for supplying current for operating the selectors at the way stations. This battery is normally disconnected from the line wires and may be connected therewith by the operation of a relay 53. A pole-changing relay Bl is provided for reversing connections from battery 85 to the line wires. The relays t6 and iii are connected in parallel and in circuit with a local battery 38, and are controlled by the impulse transmi ters 89, Q9 and ill. The transmitter till is for calling w ay station B, $6 for calling way station C, and 9i for calling both way stations in case of emergency. The transmitters are adapted to rotate in the direction of the arrow and are provided with teeth to control the operation of contact springs 9t and Si in circuit with the pol changing relay Bl. Certain of the teeth in the transmitters 89 and lid are blocked out by means of one or both adjustable cams 9 and 95 to obtain the particular number and combination of eifective teeth for calling purposes. The free end of contact spring er of transmitters lit and 5 is bent downward and carries at the extremity thereof an insulating roller til which, as the transmitter rotates is adapted to ride on top of th cam t5 and separate contacts i i and @l during the time of passage of the cam and the contact spring 523 of each transmitter is normally out of engagement with the rotatable thereof and during the revolution of the disc of each transmitter, contact spring 963 is in engagement with the disc maintaining the circuit of relay t5 closed to connect battery E5 to the line wires 2'9 and M. It is to be understood that when potential of either polarity is applied to the line for a sufiicient interval, the condenser i i-it becomes charged, whereupon the flow of current through that an emergency signal is being sent.

the electromagnet coils 5-5 ceases and the selector magnets release, allowing the wheel 20 to return to normal position. These transmitters will operate to cause the sending of signal impulses divided into three groups with appreciable pauses between each group of impulses. Upon the sending of these impulses the selectors at the way stations will step their wheels 25! around in the direction indicated by the arrows, to move the Wiper contacts El towards the fixed contacts 22, 23 and 2d. The holding pins 27 and 2% on the selector at station E are so set that this selector will reach a contact-making position when the transmitter iii! is operated, the holding pins serving to hold the wheel 26 against return to normal position during the interdi ital pauses between groups of impulses. All other selectors in the system will return to normal position during the interdigital pauses when the transmitter 89 is operating. The selector at way station C has its holding pins set so that this selector will reach a contact-making position when the transmitter $9 is operated. All other selectors will return to normal position during the interdigital pauses. The signaling device it at way station B will therefore be operated when the transmitter 88 is operated and the signal device 76 at way station C will be operated when transmitter as is operated. Other transmitters (not shown) may be provided at the centra1 station A to selectively cause the selectors at the way stations B and C to advance to the contacts 253 and 25.

When the transmitter 98 is operated all selectors la in the system will be operated to step the wheels 2Z9 around as far as they can go. Since the transmitter Ql has no cams 9 3 and provided therein and will not operate to cause interdigital pauses to occur in the series of impulses sent and the impulses sent will be of sufficient number to step the wheels 28 around to bring the cams liil into engagement with the knobs ill, the signal devices l2! at all way stations will be brought into operation to indicate The system, including selectors of this invention may therefore be used in selectively signaling way stations from a central station and in simultaneously signaling all such way stations to indicate an emergency condition.

The improved selector might also be used in a radio system for bringing into operation signal devices at remote stations to indicate that an SOS call is about to be sent. In this case as shown in Fig. i, a central station A might send a radio signal to substations B and C to indicate an emergency condition. Station A in this case would be equipped with a transmitter 9i shown in Fig. 3 and the substations B and C would be equipped with the improved selector i2 and the signal devices IZI, the only difierence between the systems shown in Figs. 3 and 4 being that in Fig. 4 the central station is equipped with radio transmitting apparatus indicated by the box I24 to transmit the emergency signal by radio, and the substations B and C are equipped with radio receiving apparatus indicated by the boxes H25 and lit to receive the radio signals and cause operation of the selectors Til in accordance therewith. Radio signals sent to cause operation of the selectors to indicate an emergency might be continued over a relatively long period to insure operation of the selectors even when storm and other atmospheric conditions are such that radio signaling is diflicult. To

take care of such conditions it is contemplated that the transmitter 9! would be arranged to send the impulses for a long enough time for the interfering atmospheric conditions to change to a more favorable condition for radio signaling. It has been found, for instance, that when the signals are continued for about three or four minutes during storm conditions the signals will get through from the transmitting station to the substations at some time during this period. The transmitter 9| in this case would be arranged to continue in operation for a long enough period to insure stepping around of the cam Hi? to a circuit closing-condition for the contacts l H and 9 58 at some time during the sending of the emergency signal impulses.

What is claimed is:

1. In a step-by-step operated selector comprising a wheel operating against a return spring for said wheel, and electromagnet means to advancerotate said wheel in step-by-step movements, in combination, a cam mounted on the rim portion of said Wheel and having a long curved finger portion pointing in the direction of advance movement of said wheel, said finger portion following the curvature of the rim of said wheel and gradually sloping upwardly from the plane or" said Wheel, a set of leaf springs supported above the plane of said wheel and arranged in normally open contact position, one of said leaf springs being relatively long and extending into the path of movement of the higher portion of said cam, said cam being operable to pass part way under said leaf springs to move said leaf springs into closed contact condition and still further flex said leaf springs to build up contact pressure therein, and the slope of the finger portion of said cam and the fieXure produced in said leaf springs by means of said cam being such that a one-step return movement of said wheel will not release said leaf springs from closed contact condition.

2. In a step-by-step operated selector comprising a wheel operating against a return spring for said wheel, and electromagnet means to ad- Vance-rotate said wheel in step-by-step movements, in combination, an L-shaped cam mounted on the side of said wheel and having an end portion extending normal to the plane of said wheel, a curved finger portion continuing from the outer end of said end portion and gradually sloping downward to the plane of said wheel and in a direction of advance movement of said wheel, a set of leaf springs supported above the plane of said wheel and having normally open contact points, one of said leaf springs extending beyond the contact point thereon and into the path of movement of the higher portion of said curved finger portion of said cam and arranged to gradually ride up on said curved finger portion of said cam when said wheel is advance-rotated to bring said cam under said leaf springs, said cam operating to pass part way under said leaf springs to first move said leaf springs into such position that the contact points thereof are in closed circuit condition and then still further flex said leaf springs to build up spring pressure therein, and the slope of said finger portion of said cam and the flexure produced in said leaf springs by means of said cam being such that during a slight return movement of said wheel the contact points on said leaf springs will remain in closed circuit condition due to the follow-up spring pressure developed in said leaf springs by means of said cam.

ALBERT H. MILLER.

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