US703777A - Cable-testing apparatus. - Google Patents

Description

no. 703,771. Patented July vl, |902;

H. w. FISHER.

CABLE TESTING APPARATUS.

(Application led July 15, 1901.)

(No Model.,

UNITED Statics Parana HENRY W. FISHER, F PITTSBURG, PENNSYLVANIA.

CELEHTE?.

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To @ZZ whom t 717/607/ con/067171,:

Be it known that I ,HENRY W. FISHER, a citizen of the United States,residin g at Pittsburg, county of Allegheny, and State of Pennsyh Vania, have invented certain new and useful Improvements in VCable-'Iestug Apparatus, of which the following is a specification.

Gable-testing apparatus, as is well known, consists of a standard high resistance, a Wheatstone bridge, a galvanometer and shunt, a standard condenser, a battery, and various keys and switches. To make the several tests, these different devices must be con nected in different ways among themselves, and to make the different connections it is necessary with some forms of cable-testin g apparatus to provide a number of iiexible connectors. It not only requires time and is in convenient to make these changes with that type of testing apparatus wherein flexible con nectors are employed, but it is necessary in order to do so to carry in mind arather comn plicated scheme of connections, which is some what difeult even for those thoroughlyfamiliar with the theory cf cable-testing. To avoid these inconveniences, I have provided a rotary switch, by means of which the changes in connection can be made witha single motion, the said switch being provided with a pointer which indicates when the desired connections are made.

My invention therefore consists of a plu rality of contacts arranged in pairs and connected with the various instruments and a roH tary switch provided with a pluralityT of contact-arms adapted to engage one set of said contacts when in one position to properly couple up the necessary instruments for one test and to engage another set of said contacts when in another position to properly couple up the instruments necessary for another test.

The details of my invention will be fully set forth hereinafter, and thenovel features thereof will be defined in the claims.

In the drawings forming part of this specin fication, Figure l is a diagrammatic view of the different instruments comprising a testing set, showing the circuit connections bc tween the same. Fig. 2 a top plan view of the coupling-switch employed, with the upper end or cover of the casing in which 'the Patent No. 703,777, dated July l, 1902.

Serial No. 68,340. (No model.)

operative parts are mounted removed. f Fig. 3 is a vertical section of: a switch on the lino cc a3 of Fig. 2.

Lilie reference-numerals indicate like parts in the different views.

The parts comprising the testing set illustrated in Fig. l of the drawings are a battery l, a battery-reverser 2, a galvanometer 3, a short-circuit key 4i, a galvanometer-reverser 5, a shunt G, a standard condenser 7, a standard high resistance S, a key 9, cable connections lO ll, IVheatstone'bridge 12, ca ble connections 13 l for the l/Vheatstone bridge, contacts 15 1G 17 1S 19 2() for the resistance Varley-loop or Murray-loop test, a battery-hey 2l, a ground connection 22, and contacts 23, 2l, 25, 26, 27, 28, 29, 30, 3l, 32, 33, 3l, S5, 3G, 37, and 3S in circuit with the diffcrentinstriunents and adapted to be coupled in pairs by the switch 39. The contacts 23 to 3S, inclusive, are preferably arranged substantially as shown and are connected with the casing d0 of the switch 39, shown in Figs. 2 and 3 of the drawings. Coperating with these contacts are the switch-arms Lil, 42, a3, and de, secured to a hollow blocl; 15 of suitable insulating material, which block is itself secured to a central shaft 4:6, mounted in suitable bearings in the upper and lower ends of the switch-casing and provided with an operating knob or handle a7. l Secured to said knob or handle or to the projecting upper end of the shaft -lG is a hand or pointer LS, which moves in front of a dial upon vthe upper face of the top or cover of the casing 40. The said dial contains such terms as Capacityf7 Insulation, Bridge,7 and when the pointer LS is opposite one or the other cf the words indicated it will show 'that the proper connections have been made by the switch for the test indicated. The switch-arms il, 4:2, 43, and ed are provided with segmental outer ends 49, each of suiicient length to bridge the circuit between two of the contacts, such as 23 and 24, 2i and 25, and 25 and 26. The connections between said switch ins and said contacts are of the knifeand-ja type, and consequently are perfectly reliable. The switch-contacts referred to are se arranged that when the pointer 48 is opicsite Capacity the contacts 23 and 21,1., 27

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and 2S, 31 and 32, and 35 and SG will be connected to each other. Likewise when the pointer L18 indicates Insnlation7 the contacts Zet and 25, 28 and 29, 32 and 39, and 36 and 3'? will be coupled together. Similar connections will be inade between the remaining contacts when the pointer 1S is opposite the word Bridge en the dial.

Two copper straps are connected, respectively, to the contacts 15 18 and adapted to connect the contact 15 with the contact 1G or 17 and the contact 1S with the contact 19 or 20. 'When 15 and 1G and 1S and 19 are connected, the apparatus is in proper condition for the Murray-loop test. tfifhen 15 and 17 and 1S and 19 are connected, the connections are correct for the Varley--loop test, and when 15 and 17 and 18 and 2O are connected the connections are proper for resistance measurements.

As an illustration of the operation of my invention let it be assumed that the switch 39 is set for insulation, with the hand or pointer i8 opposite the word insulation on the dial. As heretofore stated, and 25, 2S and 29, 32 and 33, and 3G and 37 willbe coupled together when the switch is in this position. The circuit from the battery 1 through the left side of the battery reverser 2 passes through the wires 50 and 51 to the contact 33, thence through switch-arm L13 to contact 32, thence through wire 59, through the standard resistance S or the cable connected with the contacts 10 and 11, according to which is unplugged, and thence through the wires 53 54k to contact 29, 'thence across switch-arm 11:2 to contact 2S, and thence through the wire 55, through the shunt (i and galvanometer 3,`and back to the battery through the wire 5G, centaet 25, switch-ar1n fil, contact 2l, and wire 5G. By tracing them out it will be 'found that all other circuits to which. the current has access are broken. rEhe circuit may be similarly traced when the switch is set 'i'or the capaeity and bridge tests, but as the particular arrangement of the circuits forms no part my invention and as they are familiar to those conversant with the practice of cabletesting, it is unnecessary to trace them out or allude to them speciiically.

0f course inthe particular forni of testing set used by ine "i employ special constr Lctions of the dil'terent apparatus and arrange thein conveniently in a suitable bex; but as these also 'form no part of my present invention it is not deemed necessary to show or describe theni specifically.

Having new described my invention, what I claim is*4 1. The combination with a plurality el instruments of a cable-testing set, a series of different circuits leading to and from said instruments and adapted to be connected up in different ways with said instruments tor making various tests, contacts arranged in pairs in said circuits, oi a switch comprising a rotary shaii't carrying a plurality of contact-arms arranged to bridge the vcircuits between the different pairs ol contacts in such manner that when said switch is in one position all the proper connections will be made with said instruments through seine of said contacts for one test and when in another position all the proper connections will be made with said instruments through other contacts for another test.

2. The combination with a plurality of instruments of a cable-testing set and a series ol' different circuits leading to and from said instruments and adapted to be connected up in different ways vtor making diiterent tests, of contacts in said circuits arranged in hori- Zontal and vertical rows, the contacts being se arranged that when the circuit is closed between all the horizontal contacts in two adjacent vertical rows the apparatus will be set ior one test and when closed between all the horizontal contae in two of the other adjacent vertical rows the apparatus will be set for another test, and rotary switch having a series of contact-ar is thereon equal in num-- ber to the contacts in each ol the vertical rows, the said arms being located one above the other in the same planes, respectively, as the horizontal rows et' contacts and having segmental l'n'ojections thereon adapted to bridge the circuit between the horizontal contaets in two adjacent rows, whereby when said switch is in one position all the proper connections with said instruments will be made for one test, and when in another p0- sition all the proper connections will be made with said instruments for another test.

1n testimony whereof have hereunto set my hand in presence et two subscribing wit HENRY YV. FISHER.

H. n. Oneens, 1'). W. Queens.

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