US1563556A - Telephone system - Google Patents

Description

E. H. CLARK TELEPHONE SYSTEM Filed Sept. 18, 1923 Dec. 1 1925. 1,563,556

Patented Dec. 1, 1925.

UNITED STATES PATENT OFFlflE EDGAR H. CLARK, OF RICHMOND HILL, NEW YORK, ASSIG-NOR TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Application filed September 18, 1923.

T 0 all whom it may coaccwi:

Be it known that I, Enean H. CLARK, a citizen of the United States of America, residing at Richmond Hill, in the countyof Queens and State of New York, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact de scription.

This invention relates to telephone systems and particularly to machine switching systems in which coordinate type switching mechanism is employed.

The object of the invention is to produce a controlling arrangement which will be positive and accurate in its action.

A feature of the invention resides in the use of slow acting relays, the operation of which depends in such a manner upon the voltage that the operating time interval may be held substantially constant for varying voltages, such variations as may occur being of a desirable character.

I-Ieretofore in circuit arrangements such as shown in the patent to S. B. WVilliams, No. 1,517,331, granted December 2, 1924, where it is necessary to cause a heavy current to flow to produce a certain result'such as to operate a magnet and to thereafter reduce the flow of such current, timing means such as a slow-releasing relay is depended upon to measure the interval. Due to the fact that a slow-releasing relay is energized for a comparatively long period prior to the opening of its circuit, its core has had time to become fully saturated, the degree of saturation depending directly upon the voltage. To-insure that the releasing time of the relay shall always be at least equal to a required minimum, it is necessary to saturate the relay to a degree represented by a point out on the flat part of the well known magnetization curve. On this portion of the curve, a given increase in voltage corresponds to a much greater time increment in the release of the relay than on the steep portion of the curve. Hence, for increasing voltages the time interval during which the heavy current flows is materially increased to the possible detriment of the apparatus.

In the present arrangement this diliiculty is overcome by the use of slow-to-operate rc lays. The operating interval of these relays is more independent of voltage changes due to the fact that their magnetization begins Serial No. 663,333.

at practically zero and is represented by the steep portion of the curve. It may be seen from the description of the circuits hereinafter that since the interval is measured by the operating time of a relay and not by the releasing time, if an increment of increase in voltage causes the timing relay to operate slightly faster, this fact will be advantageous. This is a desirable result since the increased voltage causes a quicker operation of the heavy current magnets and therefore the time interval to provide for the completion of the operation of the magnet may be correspondingly short.

The invention is shown in a single sheet of drawing comprising a diagrammatic illustration of the preferred form of circuit arrangement.

When the subscriber at substation 1 removes his receiver from its hook, line relay 2 becomes energized. Relay 4 thereupon operates over a circuit from ground, back contact and inner lefthand armature of relay 3, front contact and righthand armature of line relay 2, winding of relay 4 to grounded battery. Relay 4 causes the energization of relay 3 through its inner right-hand armature and closes a circuit from ground, normal contacts of the armature of relay 5, armature and back contact of relay 6, outer right-hand armature of relay 4:, right-hand winding of relay 7 to battery and-ground. Relay 7 attracts its armatures and closes, first a circuit for relay 8 through its outer righthand armature, second, a holding circuit for relay 3 through its inner right-hand armature, and third, a locking circuit for itself from ground, normal contacts of the armature of relay 5, winding of relay 6, inner left-hand armature and back contact of relay 9, inner left-hand armature and front contact of relay 7, left-hand winding of re lay 7 to battery and ground. The energization of relay 3 opens the circuit of relay 4 so that this relay now becomes deenergized but relays 3, 7 and 8 remainenergized. In series with relay 7, relay 6 becomes energized and transfers the ground connection from its back contact to its front contact whereupon a circuit is established from ground, the normal contacts of the armature of relay 5, armature and front contact of relay 6, left-hand armature and back contact of relay l0, outer left-hand armature and front contact of relay 7 outer left-hand armature and front contact of relay 3, lefthand armature and front contact of relay 2, upper winding of relay 11 to battery and ground. Relay 11 becomes energized in this circuit and closes a locking circuit through the winding of relay 10, the inner lower armature and front contact of relay 11, the lower winding of relay 11 to battery and ground. Relay 10 operates in this circuit. Ground is now extended from the armature and front contact of relay 10 through the upper armature and front contact of relay 11 to vertical magnet 12 causing the energization of this magnet. At the same time, a circuit is closed from ground, the ari'nature and front contact of relay 10, through the lowermost armature and front contact of relay 11, the inner lower arn'iature and back contact of relay l3, winding of vertical magnet lt to battery and ground causing the energization of this magnet. Upon the energiZation of magnets 1.2 and 14: a circuit is closed from ground, front contact and outer lower armature of magnet 1e, conductor 15, outer lower arn'iature and front contact of magnet 12, conductor 16, winding of relay 17 to battery and ground. Simultaneously therewith a circuit is closed from ground through the front contact and outer lower armature of magnet ll, conductor 15, theinner lower armature and front contact of magnet 12, conductor 18. front contact and innermost left-hand armature of relay 8, inner left-hand armature and back contact of relay 19, right-hand winding of horizontal magnet 20 to battery and ground, It will be noted that the two vertical magnets ointly control the circuit for the energization of the horizontal magnet and that at the same time they close a circuit for limiting the energization of the horizontal magnet. This circuit is through the winding of relay 1? as traced. Upon the closure of this circuitthe armature of relay 1? is attracted but this relay being slow to operate does not close the circuit controlled by itself for a definite interval. At the end of this interval, relay which is also a slow operating relay becomes energized. Thus, through the operation of relays 17 and 5, the ground supplied at the normal contacts of the armature of relay is removed in a definite interval which is measured from the time when magnet 20 first becomes operated.

Upon the energization of magnets 12, 1t and 20, switching devices 21 and 22 become operated so that the line of substation 1 is extended to trunk Upon the establishment of this connection, a ground is extended over the front contact and inner lower armature of magnet 14k to the third conductor of the line which leads to the cut-off rela -f 24 which, becoming energized, opens the circuit for line relay 2. This ground connection to the third conductor through the ucasse agency of magnet 14; is only temporary and will remain there only until the ground is returned on the third conductor from the apparatus connected to trun t 23 in the ordinary and well known manner.

Upon the energization of relay .1, relays (i' and become deenergized whereupon the magnets 12 and let. immediately restore their armatures and by so doing remove the. ground supplied for the energization of magnet 20. However, by this time a ground is extended over the third conductor of the transfer circuit leading between switching devices 21 and 22 through the winding of relay 19 and thence through the two windings of magnet in series, which is sufficient not only to energize relay 19 but to cause the continued energization of magnet 20. The energization of relay 5 also causes the deenergization of relays 3, 7 and 8 which release. The locking circuit of relay 11 is also opened and this relay becomes deenergized but relay 13 becomes energized upon the deenergization of magnet 14 in a circuit from the third conductor of the trunk through the inner lower armature of magnet 14 at its back contact and the upper winding of relay 13 to battery and ground.

The lower winding of relay 13 is provided so that if during the extension of a connection to another trunk, the circuit for the up per winding of relay 13 should become opened then this relay will remain energized through its lower winding and hence in this way double connections are prevented.

At the end of the conversation the ground on the third conductor of trunk 23 is removed in the well known manner resulting in the deenergization of relays 13, 19 and 2a and the deenergization of magnet 20 whereupon the apparatus concerned in this connection is wholly restored to normal.

lVhat is claimed is: I

1. In a telephone system, line magnets, link magnets, trunk magnets, a circuit for said link magnets controlled by said other magnets, and time controlling means for limiting the closing period of said circuit to a definite interval.

2. In a telephone system, line magnets, link magnets, trunk magnets, a circuit for said link magnets controlled by said other magnets-and another circuit controlled by said other magnets including relays slow to operate, said slow operating relays determining the closing period of said first circuit.

in a telephone system, lines, links and trunks, separately operable switching mechanisms for connecting said lines to said links, separately operable switching mechanisms for connecting said links to said trunks, line magnets, link magnets and trunk magnets cooperating to operate said switching mechanisms to extend said lines through said links to said trunks, circuits for said link magnets controlled by said other magnets, and timing means for determining the length of the closing period of said circuit.

4:. In a coordinate telephone system, line and trunk magnets for preparing a connection, link magnets for completing a prepared connection, circuits for said link magnets controlled by said other magnets, a timing device, and a circuit for said device controlled by said other magnets, said device having means for limiting the control exercised over said link magnets to a definite interval.

5. The combination in a telephone system of a switch having a link for interconnecting incoming and outgoing lines, a magnet for said link, switch operating members, a circuit for said magnet, a timing relay, a circuit for said relay, both said circuits being closed by said switch operating members, means controlled by said relay upon its operation for opening the circuit of said magnet, and a source of energy for operat ing both the relay and the magnet, said relay adapted to measure an interval always greater than the interval required for the magnet to operate.

In witness whereof, I hereunto subscribe my name this 4th day of September A. D, 1923.

EDGAR H. CLARK.

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