US2383794A - Telephone system - Google Patents

Description

Aug.2s,1945. E HAYS v2,383,794

TELEPHONE SYSTEM Filed Jan. 5, 1944 Switch Z' t M /c l giJc/i l F' 2 Y Y mm E En? @mm a f ,60S

ATTORNEY j.

Patented Aug. 28, 1945 UNITED STATES PATENTv OFFICE.

TELEPHONE SYSTEM Earl Joseph Hayes, Chicago,.1ll., assgnor to American Telephone and Telegraph Company,

a corporation of New Yorky Y K Application January 5, 1944; Serial' No. `516,998

s claims. (c1. 1ra-175.21)

which, in turn, is controlled by the subscriber through the medium of his dial. A selector might be termed a device for automatically connecting a given trunk to'any one of several other trunks or to any one of several lines. Each panel selector unit would usually consist of sixty multipled terminals in each of `one hundred rows withy a separate brush being provided for each of the'sixty lterminals of the multiple. The trunks or lines outgoing from a selector unit are connected to the multiple banks of terminals in front of the brushes. Certain of these outgoing trunks or lines would be terminated on a set of selecting brushes` of the next selector unit. The brushes are so arranged that they maybe driven upward over the multiple bank terminals until the desired terminal has been reached. The connections established by these lines or trunks between the multiple banks of terminals of one selector unit and the brushes of another selector unit would under certain circumstances `be. completed through a test and make-busy jack box. An illustration of this would be where the connections were between a district selector and an oilice selector although such jack Iboxes might also be used in connection with other types of selectors.

The test and make-busy jack box would be provided with a jack individual to each of the connections between one selector unit and another selector unit, and its purpose is to provide a means whereby a busy condition may be applied vlto each of the connections by the test man so that the oice selectors associated therewith may be tested. When the test man decides to test a certain connection, he inserts a make-busy plug into the jack individual tothe connection to be tested. Before inserting the make-busy plug into the jack he. would have to look at 'the selector frame and see if the brush of the connection in question had returned to normal, or back to its bearing plate, after the termination of a service call. If the plug were inserted in the jack during the connectionperiod, apparatus would function to' cut off the connection in question and interrupt the service call. Accordingly, the test man must wait for the circuit'torestore to normal before inserting the standard'make-busy plug in the makebusy'jack. It has been found that this may cause a considerable waste of the test mans time, particularly'iniiat rate and suburban areas, where holding times of selectors in the vtalking chains may be excessive. It is the primary object of the arrangements of the invention to provide arrangements which may :be inserted in the make-busy jack before the circuit has restored to normal and while a service call is in being without causing a cut-off ofthe call. When the call is completed, the arrangements of the invention automatically makeY busy theI connection under consideration, anda test thereon may be made at the convenience of the test'man. Thus considerable time may be saved onthe test mans part. Other objects and features ofthe invention will appear more fully from the detailed description thereof hereinafter given.

The invention may be more fully understood from the folowing'description together with the accompanying drawing in the Figures l, 2 and 3 of'which the invention is illustrated. In Fi'g. 1 is shown' a `circuit diagram'of portions of a district selector'v and an ofce selector with connections from certain of the multiple banks of terl minals of the district selectory tovcertain of the brushes of the oflice selector, the said connections being completed through a test and'make-busy jack box. Fig. 2 shows in detail the circuit arrangements of oneof the jacks in the jack box and the standard make-busy plug'usually utilized therewith. In Fig. 3 are shown in detail the arrangements of the invention adapted to be used with' the test andmake-busy jack box'under. certain conditions instead of the standard makebusy plug. Similar reference characters have been utilized tov denote like partsin all of the figures.v y

In Fig. 1, at the left of the drawing, is shown a portion of a district. selector of the panel type Whichis well known in the art. Such a selector would usually consist of one hundred rows of multiple terminals, each row or bank having sixty terminals. Onlyv rows or banks D, I, 2, 3, 4,

' 58, 59 and 99 are shown and only a portion of the sixty terminals in each row or bank have been shown. For each of the sixty terminals in the banks there would be provided a selector brush. Only the brushes of one bank of selectory-l, ,3; 53, 55, y5l: and 59l have been shown. ,These brushes would normally, when not being used= to complete a ca1l,rest"ona bearing plate |02. Each of the brushes would be provided with an elevator rod. For example, brush I is provided with the elevator rod IOI and brush 3 is provided vvith the elevator rod |03. These elevator rods would cause the brushes to move vertically until they reached a desired terminal on a desired row or bank of contacts. At the right of the figure is shown a similar portion of an ofce selector. Only rows or banks 0, I, 2, 3, 4, 58, 59"

and 99 are shown, and only a portion of the sixty terminals in each row or bank have been shown. This selector would also be provided with brushes of which I', 3', 53', 55', 51 and 59' are shown. Y, These brushes in a similar manner lwould bel provided with elevator rods. For example, brush I' and brush 3 are shown with the elevator rods |I and |03. 51 has been elevated to the number one bank of contacts, and the other brushes are shown resting on the bearing plate indicating that they are not being used to complete a call. In the oce selector the brush 51 has been shown elevated to the number two row of contacts to indicate that it is being used to complete a call. Certain of the banks of multiple terminals of the district selector would be connected to the brushes of the oice selector. For the purposes of illustrating this invention the 59th row of district terminals is shown connected by conductors |05 to the brush I of the oice selector and the 58th row of terminals is connected by conductors |06 to brush 3'. In a similar manner the 4th, 3rd, 2nd and lst rows of the terminals of the district selector are connected, respectively, by conductors |01, |98, |09 and IIII to the brushes 53', 55', 51' and 59 of the oiiice selector. Inconnecting the rows of terminals of the district selector to the brushes of the office selector, the conductors |05 to H0, inclusive, will -be associated with a test and make-busy jack box |04. This jack box would have a jack individual to each of the sixty selectors provided on the ofceframe. 'Ihe purpose. of this jack box is to allow the test man to place a busy condition on any one of the conductors such as |05 to ||0, inclusive, so that he may test the selectors associated therewith. To do this the test man would normally insert a standard make-busy plug into the jack individual to the office selector he wished to test. Before doing this the test man would have to look at the oflice selector and see whether the brush associated with the selector he desired to test was in an elevated position such as brush 51', or was in its normal position such, for exampie, as brushes 53 and 55'. If for the purposes Aof illustration, the test man wished to test the selector associated with conductors |09, and having looked at the office selector frame and ascertained that the brush'51 was not resting on the bearing plate |02', he could not insert his standard make-busy plug into the jack in the jack box |04 because to do so'would cause the circuit associated with brush 51 which was in service, to be cut off. A more detailed description of the mechanism for performing this cut-01T will be given hereinafter. Accordingly, he would have to wait until brush 51 returned to its normal position or back to the bearing plate I 02 when the call was completed. As heretofore pointed out, this sometimes would cause a considerable delay due to the fact that the call in question might be unduly prolonged. Y

In Fig. 2 areshown, in more detail, the circuit arrangements of one of the jacks of the test and make-busy kjack box |04.' As heretofore pointed In the district selector the brush out, the tip, ring and sleeve conductors |09 connect the second bank of terminals of the district selector to the brush 51. As shown in Fig. 2, .the tip and ring conductors are directly connected to the brush 51 and are multipled to the jack box |04. The sleeve conductor, however, is not directly connected to the brush 51 but is only connected thereto through the medium of the jack box |04 and the contacts of the jack J Shown associated with the jack J is the standard make-busy plug P1. It will be seen that if the plug P1 is inserted in the jack J the sleeve circuit S will be opened at the upper contact of the jack. This will break the sleeve connection and this breaking of the sleeve connection will cause relay I I5 to release. This will close a cirr cuit for the sequence switch I I6 which, in a manner well known in the art, will advance and cut 01T the tip and ring conductors. A ground will also be applied over the lower contact of the jack to the. sleeve conductor to place a busy condition on conductors |09. Accordingly, if the test man should insert the standard make-busy plug P1 into the jack J while the brush 51' is handling a service call, an existing connection would be broken and the service disturbed. As heretofore pointed out, the test man would, accordingly, have to -wait an indenite length of time until the spring 51 returned to its normal position. f

To prevent any such delay or waste of time, the arrangements of the invention, which are shown in Fig. 3, are provided. These arrangements consist of a plug P2 which has only a sleeve contact. This sleeve contact is connected by conductor III to a thin conducting plate ||2 which is mounted on a thin non-conducting member IIS which may be alxed by the spring II|| to the bearing plate |02. This device would be aixed, for example, inclose proximity to the elevator rod of the brush,lsuch as brush 51', connected to the line to be tested. Due to the fact that the member |I3 is a non-conducting member no ground is connected to the sleeve of the plug P2 at this time. The plug Pz can be inserted in the jack J duringvthe existence of a service call without having any effect on the circuit arrangements because the contact spring assembly in jack J will not be moved due to the fact that the plug P2 has no tip or ring contacts. Accordingly, the test man can clip the device of the invention on to the bearing plate |02 and insert the plug P2 in the jack J even while a call is in progress and continue on other business. When the brush 51 returns to its normal position on the bearing plate |02 at the termination of the call, a portion of the brush member 51',

lwhich is always grounded, will rest on the conducting plate ||2. This will apply ground to the sleeve of the plug P2 and thence to the sleeve of the circuit |09 and cause the circuit to be tested to remain busy even after the service call thereon was completed. The circuit including the selector to be tested will now remain in a busy condition so that it cannot-again be utilized for service and will remain this way until the test man returns to complete his test. When the test man returns he may remove the plug P2 from the jack and either Vconnect a standard make-busy plug to the jack or connect other testing apparatus thereto.

While the arrangements of the invention have been disclosed as embodied in certain specific forms which are deemed desirable, it is understood that they are capable of embodiment in many and other widely varied forms without departing from the spirit ofthe invention as defined by the appended claims.

What isr claimed is:

1. A device adapted to be connected to a jack of a test and makeebusy jack box associated with a selector frame in a machine switching telephone system of the panel type, said device comprising a plug having only a sleeve contact Whereby when it is inserted in a jack of said box the spring contacts of the jack will not be disturbed and no cut-off will occur on a line connected thereto, a conductor connected to the sleeve contact of said plug, and means to aix said conductor to a selector frame whereby when a selector being tested returns to its normal position upon the completion of a call a ground will be applied to said conductor and from thence to the sleeve contact of the jack to which said plug is connected to place a busy condition on the line connected thereto.

2. A device adapted to be connected to a jack of a test and make-busy jack box associated with a selector frame in a machine switching telephone system of the panel type, said device comprising a plug having only a sleeve contact whereby when it is inserted in a jack of said box the spring -contacts of the jack will not be disturbed and no cut-01T will occur on a linev connected thereto, a conductor connected to the sleeve contact of said plug, a thin non-conducting member, a thin conducting member mounted on said non-conducting member and connected to said conductor, and

. means to clamp said non-conducting member on the bearing plateof a selector frame in such a position that when a selector which is in use and is to be tested returns to its normal position on the bearing p-late the ground connected to the selector will be applied to said conducting member and thence to the sleeve of said plug to place a busy condition on the line associated therewith. 3. A device adapted to be connected to a jack of a test and make-busy jack box associated with a selector frame in a machine switching telephone system of the panel type, said device comprising a plug which may be inserted in a jack of said box without disturbing the spring contacts .of the jack and causing a cut-01T on a line connected to said contacts, and means for connecting said plug to a selector frame so that When a selector which is in use and is to be tested returns to its normal position, after a call is termina-ted ground will be applied to said selector to said plug to place a busy condition on the line associated with said plllg- EARL JOSEPH HAYES.

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