US2267129A - Testing apparatus - Google Patents

Description

1- c. PAULSON TESTING APPARATUS Filed Jul 10-, 1940 SheQtS-Shet 2 INVQNTOR. A 7 00/50 Dec. 23, 1941. -.C.-PAUL$ON A I I TESTING APPARATUS Filed July 10, 1940 7 'Sheets-Shet v INVENTQR. 6., al/A500 Dec. 23, 1941; c. PAULSON v 2,267,129 I TES TING APPARATUS Filed July 10, 1940 7 Sheets-Sheet 5 mvgmon. C. pay/500 ATTORNEY.

Dec. 23, 1941. c. PAULSON 2,267,129

TESTING APPARATUS Filed July 10, 1940 "r Sheets-Sheet e INVENTOR. C. ay/500 Dec. 23, 1941.

c. PAULSON 2,267,129

TESTING APPARATUS Filed July 10, 1940 7 She'ts-Sheet 7 252 l T y INVENT OR.

Z CL pay/500' ATTORNEY.

Patented Dec. 23, 1941 TESTING APPARATUS Christian Paulson, Ejlmhurst, Ill., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application July 10, 1940, Serial No. 344,672

9 Claims.

This invention relates to testing apparatus and more particularly to apparatus for repeatedly applying tests to telephone calling dials during the adjustment thereof.

In the manufacture of calling dials for automatic telephone systems, the contact springs in the dial, which control the pulses transmitted in calling a subscriber or which short-circuitthe telephone transmitter during the transmission of selecting impulses, must be adjusted to engage their cooperating springs at predetermined pressures. Similarly, the contact springs which open the talking circuit through the telephone receiver must be adjusted so that they break their circuit after the finger wheel of the dial has moved a predetermined amount from its normal position and before it has moved a slightly greater predetermined amount. The contacts which control the pulses transmitted in calling a subscriber must be adjusted so that they will, on the return of the finger wheel to normal to transmit impulses, be closed a predetermined amount of the time in proportion to the time they are open. The adjustment of these contact springs to give them the desired operating characteristics necessitates bending the springs manually after they are assembled and, in bending one of the springs to give it the desired operating characteristic, another spring may be affected so that it will be out of proper adjustment due to the fact that some of the springs have to be adjusted for more than one characteristic.

In the past, the adjustment of the springs of dials has entailed a great amount of tedious manual work, since the method followed was to make an adjustment in a spring, then operate the dial manually to see if the springs operated in the proper sequence, and then manually test them to see that they operated properly. If necessary, another adjustment was made and the process repeated.

It is an object of the present invention to pro vide a unitary device for repeatedly making a series of tests of the various characteristics of electrical apparatus during the adjustment of parts of the apparatus.

In accordance with one embodiment of the invention, a fixture is provided forreceiving a telephone dial with the springs of the dial extending,

outwardly from the fixture whereby they may be adjusted. The fixture for receiving the dial is tiltable and slidable and when the apparatus is in its normal or inoperative position, the tiltable fixture is tilted outwardly to a position where it may receive a dial, suitable abutments being provided to properly position the dial in the fixture. After a dial has been placed in the fixture, the fixture may be tilted to substantially vertical position, whereupon the main actuating lever of the apparatus may be operated manually. The manual operation of this lever causes the dial receiving fixture to be slid'into position to have a series of tests applied to it. The handle' which actuates the fixture to move the dial therein to its testing position also causes the driven member of a clutch to move a finger carried by it into one of the holes in the dial and just shortly after the finger engages the finger hole in the dial, continued movement of the manual lever will cause the driving clutch member to engage the driven clutch member and prepare the dial for repeated operation.

In the embodiment of the invention being described herein, the number 41 is dialed repeatedly and the finger on the driven clutch member will float when the driven clutch member is disengaged from the driving clutch member so that the dial will not be. moved out of its normal position during the engagement of the finger Wheel thereof by the finger mounted on the driven clutch member. The single manually operable lever provided in the present device also serves to unlock a cam driven gear segment which drives the driving clutch member, suitable interlocking mechanism being provided to insure that the driven clutch member will always start at the same position. Just prior to the time when themanually operable lever releases the gear segment for operation, it releases two groups of gauges to permit them to move downwardly into position to engage springs in the dial which are to be tested. As soon as the interlockjmentioned hereinbefore unlocks at its'proper cyclic interval, the gear segment will drive the finger wheel and a series of cams operating in timed relation to, the gear segment will cause the gauges to apply force to the springs in the dial to determine if some of them, which are to be tested for tension, have the proper tension. The 1 present apparatus is provided with a number of electrical timing cams which control the testing circuits to apply the tests in adefinite, cyclic order.. These cams are continuously driven, as are the cams. which drive the gages, and which actuate the gear segment so that the time of initiation of each test is accurately controlled. When the apparatus is in its normal, inoperative position, the electrical timing cams and the gage and gear segment actuating cams. operate repeatedly to no efiect. However, when the manually operable lever is moved to a position to start testing operations, the interlock will cause the sequence of tests to start at a definite time in the cycle of the apparatus.

A better understanding of the invention may be had by reference to the following detailed description when considered in conjunction with the accompanying drawings, wherein Fig. 1 is a plan view of a testing apparatus embodying the present invention with the top cover of the apparatus removed to show the various parts inside the apparatus, parts being broken away to permit showing the apparatus on a larger scale;

Fig. 2 is a front elevational view of the apparatus, part being broken away to conserve space, and showing the gaging instruments which the operator of the device scans during the. adjust-- ments of a dial;

Fig. 3 is a vertical sectional view taken substantially along the line 3,-3 of Fig. 1 in the direction of the: arrows and showing some of the details: of construction of the clutch mechanism, partsbeing broken away to more clearly illustrate those parts of the apparatus which are a short distance in back of the line on which the view is. taken;

Fig. 4 is a vertical sectional view taken along; the line 4-4 of Fig. 1 in, the direction of the arrows showing the main driving cam which drives the clutch, element and the cam shaft actuated bythe manually operable lever for controlling the operation of the various; parts of the apparatus in the proper sequence;

5 is a detail sectional view showing the cam which, twice in each cycle of the machine, drops the gages down into position to. engage the springs of the dial;-

Fig. 6 is a detail sectional view showing one of the cams for moving a gage spring through an. arcuatepath to apply tension to one of the springs in the dial after the. gages have been dropped to that position by. the cam shown in Fig. 5};

Fig, 7 is a vertical sectional viewtaken substantially along the line of Fig. 1 showing details of the interlocking mechanism which insures that the clutch driving gear segment will start only at a definite time in the cycle of tests made by the apparatus;

Fig. 8 is an irregular vertical sectional view" taken substantially along the line 8-8 of Fig. l in the direction of the arrows showing details of the dial holding fixture, the clutch mechanism andthe various driving cams;

Fig. 9 is an enlarged fragmentary sectionalview taken substantially along the line 9-9. of Fig. 2 in the direction of, the arrows and showing some of. the details of construction of the clutch mechanism, and a dial holding fixture, as well as the. relative position of the gage springs which engage the springs on the dial to test them;

Fig. 10 is an enlarged fragmentary front elevational view of the gage springs engaging thecontact springs of thedial and is taken substantially. along the-line l fl.-I0 of Fig. 9 in thedirection of the arrows, and,

Fig. 11 is a. circuit schematic showing the electrical. connections made by the electrical timing cams or discs in applying the various tests to the dial springs.

Referring to the drawings, wherein likereference characters designate. the same parts throughout the several views, particular reference being. had; at this time to Figs. 8, 9 and 10, where- The dial to be tested The dial 20 comprises a casing or housing 2| on which there is mounted a governor 22 which controls the speed of the dial in returning to its normal position under spring propulsion, at which time the number dialed by a telephone user is transmitted over the telephone circuits to select the called telephone subscriber. A finger wheel 23; having ten finger holes 2'4 therein, is mounted in spaced relation to the casing 2| for manipulation by a subscriber in calling another subscriber of the telephone system. Mounted upon the back of the casing 2| are a series of springs or contact members 25, 26, 21, 28, 29 and 30. The contact member 25 and spring 26 are normally in engagement to complete a circuit through them: which. comprises a part of the talking circuit of the telephone system. The contact member 25 and spring 26- are, therefore, insulated one from another at their lower end, as viewed in Fig. 10, a suitable mounting bracket 31a also insulated from the springs and contact members being provided for supporting them on the casing. The contact spring 26 and contact spring 21 are interconnected by an insulator 32 so that they move together when they are released from engagement with a camming member 33. actuated by the finger wheel of the dial, the springs 26 and. 21. being normally biased to move thespring 26 out of engagement with the contact member 25- and to move the spring 21 into engagement with the contact member 28. Engagement ofthe contact member 28 by the contact, spring 21 short-circuits the transmitter unit Qf the. telephone during dialing operations. The

. spring 29 and contact member 30 comprise the impulsing contacts which are made and broken to transmit impulses in the calling of one subscriber by another. These springs are biased so that they are normally closed and will be intermittently broken by a camming member 34 operated under control of the finger wheel of the dial. The camming member 34, it will be understood, in the operation of this device and in the ordinary operation of the telephone dial, is ineffective,- to break the contact between the contact member 30 and spring 29 during the windup of the finger wheel 23 ofthe dial, but intermittently breaks this circuit on the return of the finger wheel to normal. The various contact members and springs 25 to 30, inclusive, are connected in any suitable manner to terminal posts 35, 36, 3-1, 38 and 39 mounted on the casing 2| in the manner as illustrated in the circuit schematic (Fig. 11) and may be interconnected with the various parts of the testing apparatus through resilient terminal members 40, 4|, 42, 43 and 4.4, respectively.

General framework of the apparatus ing parts of the. apparatus. Also, extending upwardly from they base plate are a pair of side plates 54 and 55V (Fig. 1)., in which there is journalled. a. main control shaft, 56 adapted to be actuated by a. manually operablehandle 51 to initiate testing operations in the machine.

, and 18 (Figs. 8 and 11).

Extending downwardly from the base plate 50, adjacent its front end, are a pairof legs 58-58 (Fig. 2), which, when the apparatus is in use, tend to tilt it so that the angle at which the ap-' paratus is positioned is such that when a dial 20 has been placed in the position to be tested, it will be at a slight slant from the vertical. However, in all of the views of the drawings, the apparatus has been shown in its flat position and where the face, intermediate and back plates 5|, 52 and 53 are in a vertical plane and the base plate 50 is in a horizontal plane.

Driving mechanism Power is supplied to the apparatus from'any suitable driving motor (not shown) which drives a main power shaft 65 continuously. The shaft 65 (Figs. 1 and 8) is journalled in suitable bearings 66 and 61 mounted on the intermediate plate 52 and back plate 53 and carries intermediate its ends a gear 68 and a main driving cam The gear 68 meshes with an idler gear 19 mounted on a stud shaft 80 and the idler 18 meshes with a gear 10 fixed to a shaft II, which is, in turn, journalled in the intermediate plate 52 and'back plate 53. The shaft 1| carries on it a set of three cams 12,-13and 14 for actuating'the gages of the apparatus, as will be described more in detail hereinafter, and four electrical cams or commutator discs 15, 16, 11

There is also journalled in the intermediate plate 52 and end plate 53 a rock shaft 85, which is normally urged into the position shown in Figs. 1, 4- and 8 by a coiled spring 86 which surrounds the shaft and is fixed to it and to the back plate 53 at 81. The rock shaft 85 carries an adjustable cam arm 88 (Figs. 1 and 8) having a cam roller 68 mounted on the free end for cooperation with the cam 69 on the main power shaft 65. The extending end of the rock shaft 85, which extends forward of the intermediate plate 52, has fixed to it a gear segment 90 (Figs. 1, 4 and8), which is in mesh with a clutch driving gear 9|.

Dial receiving fixture As previously pointed out, a dial receiving fixture is provided. This fixture has been designated generally by the numeral I60 and comprises, in addition to the terminal members 40,

4|, 42, 43 and 44, a block IOI of insulating 138,- terial in which the terminal members are mounted. This block IOI (Fig. 10) is mounted upon' a gate I02 having a hinge portion I03 extending downwardly into a cooperating hinge plate I04 being pivotally held therein by a pin I05. The hinge plate I04 is provided with extending portions I06 and I51, which extend into slots I08 and I09, respectively (Figs. 2, 8 and 9) formed by shouldered member H and III mounted on the face of the face plate and cooperating with the face plate 5| to form the slots I06 and I09. The gate I82 is provided with a pair of lugs H2 and H3, which, when the gate is moved to its vertical position, pass through notched-out portions H4 and H5 in the plates H0 and III and into the grooves I58 and I09 so that when the dial receiving fixture is moved.

bodily upward, as will be described, the gate I02 will be locked in position with the lugs H2 and. H3 in back of the shoulder on the shouldered members H0 and III. "The gate I02 is provided with an irregularly shaped aperture I25 (Figs. 2, 8 and 10) for receiving the dial governor 22 and springs and contact members 25 to mentioned block 30, inclusive. The hinge plate I04 has fixedto it a holding plate I24 provided with a pair. of rounded shoulders I26 and I21, against which the face of the casing 2| of the dial will rest when the dial is placed between the gate I02 and holding plate I24. It will thus be apparent that with the gate I02 in the position shown in Fig. 8, a dial to be tested may beplaced in the gate, where it will be loosely held and after the gate has been moved to the position shown in Fig. 2, the dialreceiving fixture may be moved upwardly to the position shown in Figs. 9 and 10, where the upper end 'of the .casing 2| will engage a sloping surface I28 of a plate I29 fixed on the rear of the face plate 5| to guide the'dial accurately into the position shown in Figs. 9 and 10, where the casing 2| will be engaged by a rounded abutment I30 and the governor 22 will be tightly engaged against a second rounded abutment I3I fixed to the face plate 5|.

The bottom edge of the hinge plate I04 (Fig. 2) has a pair of notches I32 and I33 formed in it for receiving relatively stiff resilient members I34 and I35, respectively, which serve as levers to move the dial receiving fixture upwardly to its gaging position, as shown in Figs. 9 and 10. The gate I02 is provided with a handle I38, whereby it may be rocked about the pin I05 when it is in its lowermost position, as shown in Figs. 2 and 8. The levers I34 and I35 are mounted on apivot block I31, pivotally mounted on a bar I31 and adapted tobe actuated by a cam I39 (Fig. 9) fixed to the-1 main control shaft 56 and engaging a cam roller I40:mounted in the above- I31.. It. is believed to b'eapparent that, as the handle .51 is moved from the position shown in Fig. 1 in a forward direction toward the front of the apparatus, the shaft 56 will be rocked ina counter-clockwise direction (Figs. 8 and 9) and will move the members Hit and I35 upwardly to lift the dial receiving fixture I00 to the position shown'in Fig. 9.

Clutch mechanism Fixed to the intermediate plate 52, as mostwith the shoulder |5| to fix the bearing sleeve I to the intermediate plate 52, a'lock nut I54 being provided to lock the threaded member I53. in place on the portion I52 of the sleeve I50. Positioned on the outer periphery of the sleeve I50 are two sets of bearings I55 and H56, of conventional construction, which serve to rotatably support a gear 8| and a clutch sleeve I58. The clutch sleeve I58 extends out over a portion of the gear hub and is fixed thereto by means of a set screw 158. From the foregoing, it will be apparent that the gear9| and clutch sleeve |56 are freely rotatable as a unit about the outer surface of the bearing sleeve I58. The bearing sleeve I 50 has an inwardly extending shoulder- I60, against which a collar I6I, formed integrally with a push rod I62, bears. urged against the shoulder I62 by a compression spring I63 interposed between it and a bushing I64 held in the right end (Fig. 9) of the bearing sleeve I50 by means-ofa set screw I65. The shoulder I and thebushing I64 serve to slidably support the push rod I62, which is' urgedxto The collar I6I is,

the left (Fig. 9) by the spring I63, to carry. a driven clutch member, designated generally by the numeral I66, into the position shownin Fig. 9. When the driven clutch member is in. the position shown in Fig. 9, a finger I61, extending outwardly'from the lefthand surface (Fig. 9) of the driven clutch member, will enter a finger hole 24 of the telephone dial 20 and the driven clutch member will be interconnected with and driven by a driving clutch member 169, which is mounted on a series of radially extending arms I69-I69, formed integrally with the clutch sleeve I58. The driving clutch member I68.is annular in configuration and has an annular shoulder I10 formed thereon adapted for cooperation with a series of resilient members I1II1I, which are mounted on a series of radially extending arms I12 formed integrally with an annular plate I13, which is, in turn, fixed to a member I14. The member I14 carries the finger I61, and is rotatably mounted, by means of bearings I15I15, on a reduced portion of the push rod I62. The radially extending arms I69 and I12 are disposed alternately in substantially the same vertical plane and a series of light tension springs I16 tend normally to hold the radially extending arms I69 and I12 equally spaced one from another. However, these springs I16 are light enough to permit partial rotation of the member I14 about the push rod I62 without moving the fingerv wheel 23 of the telephone dial out of its normal position when the finger I61 is moving into the finger hole 24 in the dial. It should be noted thatthe end of the finger I61 is tapered slightly so that, if the push rod I62 moves to the left (Fig. 9) and the finger I61 is not in exact registration with the finger hole 23, the member I14 willbe rotated slightly about the push rod I62 until the resilient members I1I, which are rounded on their outer ends to conform to the configuration of the shoulder I10, engage with and grip the shoulder I16.

The clutch mechanism is shown in its operative position in Fig. 9 and in its inoperative position in Fig. 8. It will be understood that the spring I63 (Fig. 9) normally urges the clutch mechanism to its operative position and the normal tension of the spring is overcome by a bifurcated lever I11 engaging in a notch I18 in the push rod I62. The lever I11 is pivotally mounted in the base plate 50 and carries an adjustable cam rod I19, which, in turn, carries a cam roller I80 for cooperation with a cam ISI mounted on the shaft 56.

The details of construction of the clutch mechanism are described more fully and claimed in my co-pending application, Serial No. 344,673, filed July 10, 1940.

Interlocking mechanism The shaft 85, which carries the gear segment 90, is normally urged to rotate in a clockwise direction (Figs. 4 and 7) by the coil spring 86 (Figs. 1 and 8) and when the handle 51 is in the inoperative position, the gear segment 90 is held in its uppermost position, as shown in Fig. 4, by a cam 200'. The cam 266 is mounted on the main control shaft 56 and engages a cam roller 20I, mounted on the end of a cam arm 262 which is, in turn, fixed to the shaft 85. When the handle 51 is moved to operative position, the cam 200 will rotate and move out of the path of cam roller 26I, thereby tending to permit the spring 86 to drive the shaft 85 if the cam 69 on shaft 65 is not engaging the cam roller 89. In

order to prevent the gear segment 96. from snap-' ping downwardly too rapidly, a lever 264, pivoted on a bracket 205, is normally urged'into position under the cam lever 88, as shown in Fig. 7, by a leaf spring 206. The leaf spring'266 is mounted on a collar 201 fixed to a shaft .208. The shaft 208 has one end journalled in the bracket 205 and has the other end journalled in a casting 209, which is formed integrally with the bracket 205. The shaft 208 is normally urged to rotate in a counter-clockwise direction (Fig. 8) by a contractile spring 210, which isfixed to a portion of the casting 209 and to a cam lever 2I I, having one end fixed to the shaft'208 and carrying at its other end a cam roller 2I2. The cam roller 2I2 bears on a cam 2I3 (Figs. 7 and 8) mounted on the main control shaft 56. When the main control shaft 56 is rocked in a counterclockwise direction (Fig. 8), the shaft 268 will, upon engagement of the cam roller 2I'2 with the low part of cam 2I3, rock in a counter-clockwise direction. However, the lever 264 will only be moved out from under the adjustable cam lever 88 by the spring 206 when the cam 69. in its highest part, raises the cam roller 69 slightly from the position shown in Fig. 7, at which time the spring 206 will snap the lever 264 out from under the cam lever 88, thereby to permit the cam roller 89 to follow the contour of the cam 69 and thereby impart oscillation to the gear'segment 90.

Gaging mechanism The gaging mechanism, as most clearly shown in Figs. 9 and 10, comprises two sets of tension springs, movable as a unit, in a vertical plane and oscillatable individually to apply tension to the springs in the dial, the tension of which is to be tested. The set of gages which measure the tension under which the spring 21 engages its associated contact 28 comprises a contact spring 220, which is in engagement with an adjustable spring 22I and presses against the spring 22I to close a contact at 222 under the same tension that the spring 21 should exert against its contact member 29. The springs 220 and 22I are mounted upon and insulated from a gage support 223 and the lower end of the spring 220 has a substantially Z-shaped insulating member 224 fixed to it for engagement with the spring '21 when the gages are moved downwardly as a unit and when the gage support 223 is rocked or oscillated individually. In a similar manner, a pair of contact springs 225 and 226 are mountedupon a gage support 221 and insulated therefrom, the spring 225 being adjustable so that the tension with which it makes contact with the spring 226 may be varied. Fixed to the lower end of the spring 226 is an insulating member 228 adapted to engage the extending end of the contact spring 29 of the dial so that upon oscillation of the gage support 221, pressure will be applied to the spring 29, tending to break its contact with the contact member 30. The gage supports 223 and 221 are mounted on the ends of rods 229 and 230, respec tively (Figs. 1, 8, 9 and 10). The rods 229 and 239 are journalled in a pair of blocks 249 and 244 somewhat loosely mounted in the face plate 5| and intermediate plate 52, respectively. The rods 229 and 230 have fixed to them, at their rear ends (right end Fig. 8), cam levers 242 and 243, respectively, which carry cam rollers 244 and 245 (Fig. 1), respectively, which are held by means of springs 246 and 241 against the peripheries of the cams 12 and 14, respectively. The springs 246 and 241 are fixed to a bracket 256 mounted on the intermediate plate 52. The rods 229 and 236 are oscillatable in the bearing 246 and 2 (Figs. 8 and 9), which are rigidly interconnected by a stay bar 25I. Journalled in the face plate I and the intermediate plate 52 is a rock shaft 252 (Figs. 1, 4, 5 and 8), which carries at its rear end a cam lever 253, having a cam roller 254 urged into engagement with the cam I3 by a spring 255. The rock shaft 252 has fixed to it, adjacent its forward. end, a lever 256 (Fig. 1), which engages the stay bar 25I (Fig. 5), and upon rotation of the cam I3, the lever 256 will be oscillated to move the block 246 downwardly to carry the gage springs into position, where they 7 may engage the springs in the dial.

The shaft 252 also has fixed to it a stop lever 266 (Figs. 4 and 8), which extends into the path of a latch 262 formed integrally with a slidable plate 263, which, in turn, abuts a bearing plate 26I and is positioned to slide between the bearing plate 26I and a cam 266, a portion of the slidable plate 263 being cut out, as shown at 268, to slidably engage the shaft 56 and the intermediate plate 52. A cam roller 265, fixed to the slidable plate 263, serves to move the plate 263 upwardly when engaged by the high part of the cam 264 to carry the latch 262 out of the path of the stop lever 266. A spring 269, fixed to a pin 261, extending outwardly from the slidable plate 263 and to a pin 266 fixed to the bearing plate 26I, normally tends to hold the slidable plate 263 in its downward position. When the shaft 56 is rotated to initiate a testing operation, the earn 264,

which is mounted on the shaft 56, will move the latch 262 out of the path of the stop lever 266 and the spring 255 (Fig. 1) will then be able to move the lever 253 and thereby rock the shaft 252 to permit the gages to drop down into association with the contact springs to be gaged.

However, when the shaft 56 is in its inoperative position, as shown in Fig. 8, the continuous operation of the cam I3 will be ineffective to drop the gates and will become effective only when the handle 57 has been operated to initiate a testing operation.

Testing circuit and operation The apparatus shown diagrammatically in the circuit schematic (Fig. 11) makes a series of tests on a dial each revolution of the shaft II and the electrical cams I5, I6, I? and I8 control the sequence of the tests. In measuring the tension of the contact springs of the dial, two testing circuits of the type described in detail and claimed in the co-pending patent application of Christian Paulson, Serial No. 298,409, filed October '7, 1939, are utilized, together with circuits for testing the proportion of time that the pulsing contacts are open and closed when the finger wheel of the dial is operated and circuits for measuring the length of time the contact springs which open the telephone talking circuit remain closed after the dial starts to move from its normal position. v

Since the circuits for performing these functions are relatively simple, they will now be described in conjunction with the description of operation of the apparatus.

In the bridge circuit for testing the tension of the contact springs, there are provided a pair of milliammeters 284 and 285, which operate in exactly the same manner as th milliammeter. shown in the Paulson application hereinbefore identified. A milliammeter 283 is used in the circuit for measuring the length of time the contact springs in the talking circuit remain closed after the dial starts to move, and in the circuit for measuring the proportion of make and break of the impulse transmitting contacts, a microammeter 282 is utilized in connection with two banks of condensers 293 and 284, which are progressively charged during the closed and open periods, respectively, of the impulsing contacts on the return of the dial to normal. In the circuit for measuring the proportion of make and break of the impulsing contacts, a series of chain relays 2'II to 286 are utilized, in conjunction with a control relay 28l, to control the flow of current from a volt direct current source to the banks of condensers 293 and 264 through suitable resistances.

If it be assumed that the circuit shown in Fig. 11 is connected to the 90 volt direct current source through any suitable switching mechanism and that the driving motor (not shown) is op erating, the apparatus is prepared to apply the tests to a telephone dial 26, the shaft 65 being continually in rotation, and, through the idler gear I9, will drive the shaft II at one-half the speed of the shaft 65. With the apparatus in this condition, a dial may be placed in the gate I62 while the gate is in the position shown in Fig. 8. After a dial has been placed in the gate I62, the gate may be closed and the handle 57 rocked to move the main control shaft 56 in a counter-clockwise direction (Figs. 8 and 9). As the shaft 56 is rocked in a counterclockwise direction, the dial will be clamped rigidly in place and the tests thereon will be initiated, it being understood-that the shaft 'II, in rotating continuously, will actuate the parts associated with it continuously. However, when no dial is in place in the apparatus, the gear segment 66 will not be rocked due to the fact that the lever 264 will extend under the adjustable cam lever 88 and prevent the cam roller 89 from following the contour of the cam 69 until the handle 57 has been moved to its ultimate position to rock the maincontrol shaft 56 in a counterclockwise direction, as was explained in detail in connection with the detailed description of the interlocking mechanism. As the shaft 56 rocks in a counter-clockwise direction from the position shown in Fig. 8 to the position shown in Fig. 9, the cam I39 will cause left ends of the members I34 and I35 to be moved upwardly, thereby to raise the gate I62 to the position shown in Fig. 9. As the gate I62 approaches the position shown in Fig. 9, the cam roller 66 will ride onto the low part of cam I8! and permit the spring I63 to move the push rod I62 to the left, thereby to carry the finger I61 into the hole 26 in the finger wheel 23 for the digit 4 on the dial mechanism. Shortly after the finger I67 enters the finger hole 24 in the dial 23, the resilient members III will engage the annular shoulder I16 to lock the driving and driven clutch parts together. Just as soon as the clutch engages, the cam 266 will move out of the path of the cam roller 26I (Fig. 4) and the next time the cam 69 (Fig. '7) raises the lever 88, the lever 264 will be snapped out of the path of the lever 68 and the cam roller 89 will follow the cam 69 to oscillate the dial back and forth until the handle 57 is again moved to inoperative position.

In moving from the position shown in Fig. 8 to the position shown in Fig. 9, the shaft 56 will rotate the cam 264 (Fig. 4) to move the cam roller 265 and thereby lift the latch 262 out of the path of the stop lever 255 so that the cams 12, T3 and 14 may operate the gage supports 223 and 221. Since the lever 264 will be snapped out of the path of the lever 268 at the same time in any cycle when the spring 23-05 has been flexed due to the movement of the handle 51 to operative position, the movement of the dial by the driven clutch member will always be synchronized with the operation of the gages under control of the cams 12, T3 and I4 and with the electrical circuits which operate under control of the electrical cams or commutator discs 15, T5, 11 and I8 and therefore the tests performed by the electrical circuits will be made in syn-- chronization with the oscillation of the dial finger wheel 23. In the operation of the testing apparatus, a dial 29, having been placed in the gate I02 and moved to testing position andthe tests initiated by the various mechanical interlocking mechanisms, the gage supports 223 :and 227 will be dropped twice into position, Where the gages carried by them can engage the contact springs to apply pressure to them in each cycle of the rotation of the shaft H due to the shape of the cam [3 (Fig. makes one revolution while the shaft 65 is making two revolutions, the cam 13 will move the gage supports 223 and 2'2: downwardly twice in each revolution of the shaft H, i. e., once for each revolution of shaft 85, and the earns 12 and M will actuate their associated gage supports 221 and 223, respectively, on alternate revolutions of the shaft 65.

The tension tests of the contact springs in the dial are made during the windup of the dial and, of course, the amount of travel of the dial before contact between the member 25 and spring 26 breaks, is also measured at the beginning of the windup of the dial. Referring to Fig. 11, 'it will be seen that as soon as a dial is in place to be tested, the terminal posts 35, 35, 3:7, 38 and 35 will be connected to the terminal members 40, ll, 42, 43 and M, respectively. As soon as these connections are made, grounded battery at 390 will be connected through resistance-3M, closed spring 26 and member 25, the milliammeter 283 to ground 303 and across shunt resistance 332 to ground 363. This circuit is designed to utilize the inherent time delay characteristic of the milliammeter to measure the length of time the member 25 and spring 26 are in contact and, accordingly, the value of the battery 3%, resistances 3M and 33-2 and milliammeter are chosen so that when the number 25 and spring 2% stay in engagement, the needle of the milliammeter will just move to full scale deflection. Therefore, the length of time that the contact member 25 and contact spring 2'6 are in engagement will be indicated by the amount of deflection of the needle of the milliammeter 283 once for each oscillation of the wheel and while the dial finger wheel is being oscillated, the spring 26 may be adjusted.

Each time the cam 13 starts to lower the gate supports to make a tension test, brush 2 of electrical cam ll makes contact with a conducting portion of the cam Ti and since the brush I associated with the cam IT is always in contact with a conducting portion thereof and is connected to ground at 335, the relay 290 will be energized over a circuit from ground at 355, through brushes I and 2, and winding of relay 290 to grounded battery 308. Thus, relay 230 will be energized throughout the entire time that a tension test is being made. When the relay Since the shaft ll 2% is energized, it'conne'ctsgrounded battery at 38-1 through-a suitable resistance 393 and a manually operated switch 309, which is closed all 'during testing operations to tension testing bridgecircuits associated with the milliammeters 284 and 285. During the first half revolution of the shaft 1 I, cam 14 will be effective'to oscillate gage support 22 1 and, therefore, the tension of spr g 29 will be tested during this interval.

The bridge circuit associated with the milliammeter 285 comprises four equal resistances 3L0, 3H, 312 and 313 'o"f any suitable value so long as they are equal and they and thepower source at grounded battery 38'! may be chosen to suit the particular milliammeter selected for use. A milliammeter should 'be chosen which takes approximately thesame length'of time to go from zero -to full scale deflection under influence of the battery-301 and the-resistances as it takes the gage spring 226 to oscillate through one cycle. When the :relay 290 is energized, the contact spring 29'yvill'ibe connected through the right :hand make contact o'f the relay to the resistance 31 0 and through the *switch :3'89 and left hand make contact'ofthe relay 299 to grounded batteryat "301. Similarly, contact member 30 will be connected through on'e of th'e' right hand make :conta'cts of relay 250 to resistances "312. Resistance 3! I is "connected to'grounrita't 316 and when contact spring 226 is in engagement with contact member'2'25, ground'at 3% will also be connected to the resistance 313. In the -operation :oi' this tension testing circuit, the insulating member 228 will-engage the spring 2 3 to open the circuit between contact spring 23 and "contact member 30 and contact springs 225 and 226. If, in the oscillation of thesgauge support 221, the contacts just mentioned open at the same time, thereby indicating that the tension in the spring 226 is equal to the tension in the spring 2'9, n'o current will now through the milliammeter 2 and, therefore, its pointer will remain stationary. Howevenshould the s'pring 2'9 under test b'e w'eak er or stronger than the spring 228, the pairs of contacts willnot open at the same instant, thus permitting current to flow through the m'te'r in one direction-or the other, depending upon which pair of springs break contact first. Since the time interval "between the breaking of contact is proportional to the difference in tension between the spring 226 and the spring '29 under test, the deflection of the meter pointer will be proportional to the difference in tension of the two springs and the direction of movement of the needle will indicate which or the two springs is stronger. Thus, an operator watching the min liammeter 385 may a'd'justthe tension in the-con tact spring '29 until the meter "po'inter remains substantially stationary under repeated tests.

During the second half cycle of the shaft H, the relay 290 will be Teenerg'ized and held energized all the time the gage supports are in their lower position. Since no tension will be applied to the spring 29, the milliammeter 28-5 will not be unbalanced. However, the spring 27 will :be in engagement with the contact member 23 and will be urged away from it 'by the insulating member 224 when the =gag e support 22 3 is "0s cillated. The energization oi-relay 290 will connect the contact spring 2Ta'hd contact member 28 to opposite 'sidesof the bridge circuit associated with the milliammeter $284, which is su plied -with suitable resistances -'in' exactly the s'ame manner as the milliammeter 235, and while the gage supports are in their lowermost positions during the second'half of the cycle of theshaft 1!, the milliammeter 284 will indicate the difference in tension between the spring 21 under test and the spring 229 mounted on the gage support.

Brush 3, associated with electrical cam 19, brush 2 associated with electrical cam and brush associated with electrical cam 15 are always in engagement with conducting portions of their respective electrical cams. Brush associated with cam 19 makes contact with a conducting portion of the cam 16 in the second half of each cycle of the shaft 65 and, therefore, ground at 329 will be connected over the left hand break contact of relay 299 to contact member 39 and when the contact spring 29 is in engagement with contact 39, the circuit will be completed through the right hand break contact of relay 299, brushes and 2 of cam 16 to one side of the winding of relay 28!, the other side of the winding of which is connected through a suitable resistance 32! to brush 3 associated with electrical cam 18, which makes in the normal position of shaft 35 and breaks for a short interval near the end of each half cycle of the shaft 65. It will be understood that the shaft 65 is the shaft which supplies power to drive the dial finger wheel in both directions and that the proportion of make time to break time of the contact 29 is measured in the second half cycle or while the dial is dialing numbers. Since the brush 15! makes contact with its associated cam on the return of the finger wheel of the dial to normal, ground at 329 will be connected through the contact of relay 399, through the contact member 39 and spring 29, which are normally in engagement, through right hand break contact of relay 299, brushes 1 and 2 associated with cam 15, through winding of relay 29! to grounded battery 322 at brush 2 of cam 13 to energize relay 28! and connect the 90 volt direct current source through a resistance 323, and variable resistance 324 to right hand make contact of relay 289, which is not energized at this time. Relay 215, however, will be energized over the ground lead from brush 2 on cam 16,.break contact of relay 289, winding of relay 215, brushes 3 and 2 of cam 18 to grounded battery at 322. The relay 28! will be held energized all the time contact is made between spring 29 and contact member 39 in their normal position. However, as soon as the dial finger wheel starts to return to normal, the relay 28! will be deenergized and the 90 volt direct current source will be connected through contact of relay 28! across the bank of condensers 294 to charge these condensers. Also, as soon as the contact between spring 29 and contact member 39 breaks, ground at 329 will be removed from one side of the winding of relay 215. However, relay 215, when it was energized, connected ground at its make contact through the winding of relay 289, winding of relay 215, through brushes 3 and 2 of cam 18, to grounded battery at 322. When the ground connection at 329 is broken by the disengagement of contact spring 29 with contact member 39, relay 289 will pull up over a path from ground at the make contact of relay 215 through the winding of relays 289 and 215 in series to grounded battery at 322. When relay 289 pulls up, it will also connect the lead from the make contact of relay 28! through a break contact of relay 211 to prepare a circuit path to one side of the bank of condensers 293. This circuit path will become efiective the next time spring 29 engages member 39, but is unefiective since the circuit is broken at relay 28!.

The bank of condensers 294 will be charged .all the time the contact between the spring 29 and the contact member 39 is open as the finger Wheel moves a portion of one digit space in its return tonormal since the bank of condensers 294 is connected at'this time to the volt direct current source. As soon as the contact between the spring 29 and contact member 39 again closes, relay 28! will be reenergized and the charging of the bank of condensers 293 will begin. Also, relay 214 will pull up over make contact of relay 280 and break contact of relay 219. When the contact between the spring 29 and contact member 39 again breaks, another charge will be sent to the bank of condensers 294. Thus, the bank of condensers 294 and the bank of condensers 293 will receive charges proportional to the length of time the contact between the springs 29 and contact member 30 are open and closed, respectively, during the return of the dial finger wheel to normal and the chain relays will pull up in succession from right to left until the dial finger wheel returns to its normal position. When chain relay 211 pulls up on the break of the last pulse, its left hand break contact will disconnect the bank of condensers 293 from the 90 volt direct current source and will energize relay 21!. Energization of relay 21! will connect one side of the microammeter 288 to one side of the bank of condensers 294 and to brush 2 associated with cam 15. At this time, brush 2, associated with cam 15, is not engaging a conducting portion of the cam 15 so that this portion of the circuit is ineffective. However, as the shaft 65 completes one cycle of rotation, brush 3 at cam 15 will engage a conducting portion of cam 15 to connect one side of the bank of condensers 293 through brush of cam 15 to one side of the microammeter 282; Now, since one side of the bank of condensers 294 is connected to one side of the microammeter 292 and one side of the bank of condensers 293 is connected to the other side of the microammeter 282, the relay 28! is reenergized, the charges in the banks of condensers 293 and 294 will be opposed, and, therefore, the needle of the microammeter 282 will be displaced from normal in one direction or the other, depending upon the charges in the banks of condensers and this will indicate whether the proportion between the make and break time of spring 29 and contact member 39 is correct and the spring 29 or contact member 39 may be adjusted to have the desired characteristics, as indicated by the microammeter 282 in staying in a predetermined position.

Shortly after the shaft 65 moves out of normal position, and after brush 3 of cam 15 has broken contact, brushes 2 and 4 of cam 15 will make contact for a short time to discharge the banks of condensers 293 and 294 over a circuit from brushes 2 and 4 through banks of condensers 293 and 294 to brush I of cam 15, thus restoring the mechanism that makes the percentage of make and break test to normal.

Although a specific embodiment of the invention has been described hereinbefore, it will be understood that the invention is to be limited only by the scope of the appended claims.

What is claimed is:

1. In an apparatus for repeatedly testing telephone dials during their adjustment, a continuously rotating shaft, a series of testing circuits repeatedly prepared for operation each time said shaft rotates, a second shaft operating in timed relation with said first-mentioned shaft, a set of gages operable under control of said first-mentioned shaft, an actuator operable by the secondmentioned shaft, and a control means for synchroni'zing the initiation of operations by the shafts in a predetermined cyclicorder.

2. In a testing apparatus for testing telephone dials during the adjustment thereof, a pair of vertically re'ciprocatable gages, means for reciprocating said gages to move them into operative relation with a piece of apparatus to be tested, means for oscillating the gages-separately to test separate parts of the apparatus being tested, means for positioning the apparatus in a predetermined position, andmeans operableunder control of said last mentioned. means for rendering the means for reciprocating -the gages operable.

3. In a testing device for telephone dials, means for moving the dial into position to be tested, a pair of gages for applying tension tests to contact springs in the dial, a bridge circuit associated with each of the gages for measuring the tension of the contact springs, means for repeatedly operating the dial, and means for rendering the tension testing circuits operable during the \vind-up of the dial.

4. In "an apparatus for repeatedly applying tests to the contact sptings of telephone dials during the adjustment thereof, means for repeatedly operating the dial, an electrical circuit connected to a pair of contacts of the dial for measuring the relative length of time after the dial starts to operate until said contacts break, circuits for measuring the tension of contact springs in the dial during the windup part of the operation of the dial, circuits for measuring the proportion of make time to break time of a pair of contacts in the dial during the return of the dial to normal, and means for synchronizing the operation of the circuits with the means for repeatedly operating the dial.

5. In an apparatus for repeatedly applying tests to the contact springs of a telephone dial during the adjustment thereof, means for repeatedly operating the dial, a plurality of circuits for applying the various tests to the contact springs of the dial, a control means for controlling theduration and sequence of the tests applied to the dial, and means operable in synchronism with said last mentioned means for initiating the operation of the dial operating mechani'sm'at a predetermined time in the cycle ape-1,1 29

of operation of the testing circuits, said means for synchronizing the operation of the dial operating mechanism with the testing circuits comprising a stop member for holding the dial operating mechanism inoperative, a spring for urging said stop member out of the path of the dial, operating mechanism, and a cam associated with the dial operating mechanism for driving it, said cam being so shaped as to move the dial operating mechanism away from said stop lever at one point in the cycle of rotation thereof.

6. In a testing apparatus for dials, means for receiving and holding a telephone dial, a continuously driven shaft, a means for oscillating the dial finger wheel, means for interconnecting the oscillating means with the driven shaft, and means for controlling the sequence of tests in timed relation to the oscillation of the finger wheel.

'7. In a testing apparatus for telephone calling dials, a continuously driven shaft, means driven to position to be tested, for rendering the tension gages operable, and for initiating operation of the means for repeatedly operating the dial.

9. In an apparatus for applying repeated tests to the contact springs in telephone dials during their adjustment, a set of reciprocatable and oscillatable gages for applying tension to contact springs in the dials, means for repeatedly operating the dial, a fixture for receiving the dial, and a unitary control means for moving the dial to position to be tested, for rendering the tension gages operable, and for initiating operation of the means for repeatedly operating the dial, said unitary control device being provided with interlocking mechanism for initiating the operation of the dial operating mechanism at a predetermined point in the cycle of operation of the means for repeatedly operating the dial.

CHRISTIAN PAULSON.

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