US1882981A - Switching mechanism - Google Patents

Description

Oct. 18, 1932.

L. J. J. SCHREIBER ET AL SWITCHING MECHANISM Filed Oct. 6, 1931 I5 Sheets-Sheet l mm bw m I QR aw mw 3. m m N CHE $.H/. JCX 6 I? 6 m T Q N :M. v, N 8 Nut ATTORNEY V Oct. 18, 1932. L. J. J. SCHREIBER ET AL 1,832,931

SWITCHING MECHANISM Filed Oct. 6, 1931 3 Sheets-Sheet 2 L. J. J. SCHRE/BER INVENTORS-QRCHEV/GNV 91X.\LENS $6M A TTORNEV Oct. 18, 1932. 1.. J. J. SCHREIBER ETAL swmnme MECHANISM Filed Oct. 6. 1951 3 Shets-Sheet 3 L.J. JSCHRE/BER INVENTORS. G.P.CHEVIGNY A TTORNE Y Patented Oct. 18, 1932 UNITED STATES PATENT OFFICE.

LOUIS J. J. SCHREIBER, GEORGES .P. CHEVIGNY, AND GEORGES X. LENS, OF PARIS, FRANCE, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK SWITCHING MECHANISM Application filed October 6, 1981, Serial No. 567,148, and in France December 8, 1980.

This invention relates to switching mechanisms and more particularly to a switching mechanism of the type used in automatic and semi-automatic telephone systems. It is es- 5 pecially applicable to a switching mechanism of the type in which a set of movable termihalls are adapted to be rotated over a set of fixed terminals. The object of the invention is to provide new and novel improvements 10 in a switching mechanism of this type which will improve its operation and also simplify manipulating, dismounting, adjusting and assembling its various parts so as to increase the overall efficiency of the said switching mechanism.

In order to more clearly understand the invention, the type of switch contemplated herein will be briefly described. The said switch is built up on a base plate on which is mounted the contact bank, the brush carriage assembly and the feeder brush assembly. The bank contacts are molded in a suitable insulating material in such a way as to form a plurality of separate levels which are placed one on top of the other and secured to the base plate. The brushes of the switch are rigidly secured to a sleeve and form a complete brush carriage assembly. This carriage is then freely mounted on a shaft rigidly secured to the base plate, the whole being free to rotate over the terminal contacts of the contact bank when driven by an external source of power.

One feature of the invention has to-do with the structure of the brush assembly for such a selector switch and, in the embodiment of the invention disclosed herein, the brush carriage is slidably mounted in a slot in the base plate to which it is secured at one end only by a single nut. The feeder brush assembly is 1 secured to the base plate by a single bolt in such a way that the tips of the feeder brushes may be swung away from the brush carriage when desired. The driving wheel is secured to the shaft by a split conical member which is clamped to the shaft by a nut, the lower portion of which is provided with a second thread for engaging with 'a member surrounding the split conical member, the two threads on the securing nut being oppositely Another feature of the invention relates to the wiper brushes which are preferably constructed of two pieces of metal, the larger portion near the switch shaft being formed of thick rigid metal and the other portion near the wlper tip being constructed of thin flexible metal. In this way a wiper is produced which has, at the same time, the necessary amount of rigidity and flexibility,

which prevents the occurrence of any vibration of the wiper on the bank contacts.

Or, according to another preferred arrangement the said brush wiper may be constructed of a single plate of metal having a long V-shaped depression or indentation which is formed in the arm of the wiper, this V-shaped depression having two arms, the point at which they join one another being deepened a little further to form a stud. A wiper of this construction is given a bendin tendency when freely supported at itsbase an when two such wipers are placed with their bases together, both studs will contact and, due to the bending tendency mentioned, the wipers will be pressed together causing'the effective vibration length of the wiper to be limited from the tip of the wiper to the stud. In this way vibration is quickly damped.

For a more detailed description of our invention reference is now made to the accompanying drawings in which:

Fig. 1 shows the front view of the switching mechanism embodying the invention;

Fig. 2 shows a sectional side view of the switching mechanism;

Fig. 3 shows a plan view of the switching mechanism and switch assembly;

Fig. 4 shows a view of the driving mechanism detached from the remaining portions of the switch and taken from underneath;

Fig. 5 shows a sectional side view of the driving mechanism seen in Fig. 4;

' Figs. 6 and 7 shows different side views of the split conical member provided forsecur- 5 in the driving Wheel to the shaft;

ig. 8 shows a plan view of a modified form of wiper brush which may be used alternative- ,ly to that illustrated in Fig. 3; Fig. 9 shows a side view of the wiper shown 10 in Fig. 8; while V.

Fig. 10 shows'a side view of two wipers such as that shown in Figs. 8 and 9 arranged with their bases togethe 7 Referring now to the drawings, it will be I seen that the switch is built up on a base plate 1 on which is mounted the contact bank 6.6,

- the brush carriage assembly 16 and the feeder brush assembly 15. The bank contacts 2 "are molded in bakelite or any other suitable insulating material in such a way as to form a plurality of separate levels which are placed orie on top of the other and secured to the base plate 1 and the plate '49 by means of the bolts 3. The brush wipers of the switch are 2 rigidly secured to the sleeve 4 by means of the two nuts 5 and 6 in such a way as to form a complete assembly. This complete brush carriage assembly is then freely mounted on the shaft 7 which is rigidly secured'to the base plate 1 by means of the single nut 8.

It will be seen that the base plate 1 is provided with a slot 9 which extends from the periphery of the plate to the centenso that when the nut 8 is loosened the whole brush carriage may be withdrawn as a single unit through the slot 9 and may thereby be entirely removed from the switch. The brush carriage, when mounted, is secured at the extreme end of the groove 9, and a slightly raised portion is provided on the base plate on which the nut of the brush carriage is adapted to fit to position the wiper assembly securely.

The switch wipers are rotated over the bank contacts 2 by means of the gear wheel 19 which is adapted to mesh with the gear wheel 20 which is rigidly mounted on the driving shaft 21. The gear wheel 20 is rigidly secured to the drivin shaft 21 b the clamping means shown in igs. 2-7. eferring in particular to these figures it will be seen that the driving gear wheel 20 is mounted between a pair of metal plates 44 and 22. The assembly of the gear wheel and plates is fixed to the shaft 21 by means of a split conical sleeve 53 which is threaded at one end to receive the securing nut 23. The lower portion of this securing nut 23 is provided with a second internal thread for engagement with the hub member 24 and the two threads 60 of the nut 23 are oppositely cut with respect to each other so that when the nut 23 is turned in a clockwise direction it is moved downwards with respect to the member 24 and, at the same time, causes the conical member 53 to be moved downwards with respect to the nut 23 so as to cause a clamping action to take place between the conical member 53 and the shaft 21 due to the fact that this conical member, on being forced downwards will close the split portions around the shaft 21 It will be seen from Fig. 7 that one split portion 27 of the member 53 is widened at its free end and this widened portion of the The whole assembly is firmly secured together by means of the nut 26 which engages with the lower threaded portion of the'hub member 24.

Qne of the slits provided in the conical member 53 is arranged to extend through the whole length of the member as shown at 54 in Fig. 6. The remaining grooves 55 are cut in such a way as to extend from the smaller end of the member to the commencement of the threaded portion 28.

The presence of the inner thread on the nut 23 allows the whole drivlng mechanism to be loosened when the nut 23 is slackened without the driving mechanism being dismantled.

When the wipers of the switch are rotating,

.the driven gear wheel 19 will be in engagement with the driving wheel 20 which is rigidly secured to the continuously rotating shaft 21. When, however, it is desired to stop the rotation of the switch wipers the magnet 29 is deenergized thereby releasing its armature 30 which causes its arm 31 to res's against the flexible gear wheel 19 therey causing the latter to be warped out of engagement with the driving wheel 20.

The armature 31 is provided at its extremity with a threaded aperture in which there is mounted a screw stud 32 which may be adjusted to any position with respect to the armature 31 and locked in such position by the nut 33.

The armature 30 is pivotally mounted on a shaft 34 which is provided with an extension piece 35 having a'hook 36 for engaging with one end of the armature restoring spring 37. The other end of this spring 37 engages with one end 38 of an L-shaped member which is pivotally mounted ina slot 39 wherein it is held by means of a bolt 40, which is mounted in the portion 31 of the framework and is arranged to press against the other arm 42 of the L-shaped member. It will be seen that the tension of the spring 37 may be adjusted by turning the bolt 40 which may be locked in its adjusted position by means of the nut 43.

When the bolt 40 is loosened the spring 37 may be removed from the end 38 of the L- shaped member, thereby allowing the latter to be freely withdrawn from the slot 39.

The magnet frame is provided with a pair of lugs 45 by means of which the whole clutch mechanism is secured to a portion 47 of the base plate 1, by means of the lag screws 46. The portion 47 is bent up at right angles from the main part of the base plate 1, and is secured to the frame work of the exchange by the bolts 48, the other side of the base plate 1 being secured by the bolt 50.

The feeder brushes 10 are mounted between blocks 11 of bakelite or other insulating material so as to form a complete assembly which is secured to the base plate 1 by means of a single bolt 12. It will be seen that at the base of the feeder brush assembly there is provided a horse-shoe shaped member 13 which engages with a somewhat similar recess 14 in the base plate 1. The dimensions of the recess 14 are slightly greater than those of 13 and the front portion of the former is made slightly convex so that when the nut 12 is loosened the feeder brush assembly may be slightly rotated about the bolt as a pivot. In this way the free ends 15 of the feeder brushes may be swung away out of engagement with the bases of the switch wipers with which they engage when they. are in their normal position.

Referring now again to the switch wipers it will be seen that these are provided at their bases with extensions 16 to insure that the ends 15 of the feeder brushes will be moved back into their proper position with respect to the switch wipers after they have been swung away from the latter.

Each switch wiper is preferably constructed in the form of two pieces of metal 17 and 18, the larger portion near the switch shaft being formed of thick rigid metal and the other portion 18 near the wiper tip being constructed from thin flexible metal. In this way a wiper is produced which has at the same time the necessary amount of rigidity and flexibility, which prevents the occurrence of any vibration of the wiper on the bank contacts. The two portions of the wipers are secured together by welding or any other suitable process. I

Referring now to Figs. 8, 9 and 10 a modified form of wiper is shown which may be used alternatively to that described above. This wiper is constructed from a single plate of metal only, 57, and is provided with an extension 63 and an aperture 64 similar to the wiper described above. The construction of the wiper tip 61 together with the fibre guide 62 is also the same. In the modified form of wiper, however, as shown in these three figures, although the wiper is constructed of a single plate of metal, chattering is prevented by means of a long V- shaped embossed portion which is formed in the arm of the wiper, this V-shaped embossment having two arms 58 and 59, the point at which they join one another being deepened a little further so as to form a stud 66 as shown in Fig. 9. A wiper of this construe tion, when supported freely at its base, is given a bending tendency as shown in Fig. 9. When the wiper is assembled on the switch, however, two such wipers will. be placed with their bases together as shown in Fig. 10 so as to engage on either side of the bank contacts 65. Thus, it will be seen that due to the bending tendency described above the two studs 66 formed by the embossment at the bases of the Vs in the wipers will be pressed together and, due to this arrangement, the vibration of the wiper arms is dependent only on the length of the whole wiper and in this way any possible chattering of the contacts is very quickly damped due to the shortness of the vibrating portion of the wiper.

While this invention has been described with respect to a line finder having 200'points it is to be understood that the invention is not limited to-this particular kind of switch and that it is equally well applicable to any other type of rotary switch mechanism having any number of points over which the switch wipers rotate.

What is claimed is:

1. A switching mechanism comprising a brush carriage and wiper brushes each formed in two portions, the portion nearest to the point ofv attachment to said carriage being ofthick, rigid metal and the other portion being of thin, flexible metal.

2. A switching mechanism comprising a brush carriage, wiper brushes cooperatively arranged in pairs thereon, each of said brushes being formed with an embossed portion between the point of attachment to said carriage and the contacting end thereof, the embossed portions of each pair of brushes abutting against each other when mounted on said rotor.

3. A switching mechanism comprising a frame, and a feeder brush assembly including a horse-shoe shaped member which is adapted to engage with a similarly shaped but slightly larger recess in the said frame to allow limited rotational movement of said feeder brush assembly.

4. A switching mechanism comprising a frame, a rotatable wiper brush assembly and a cooperating feeder brush assembly, said feeder brush assembly being pivotally mounted on said frame to permit it to be swung out of contact with said rotatable wiper brush assembly.

5. In an automatic switching mechanism a shaft, a gear wheel, and means for locking said gear wheel to said shaft comprising male and female conical clamping devices and a nut having right and left-handed threads.

6. In an automatic switching mechanism, a shaft, a gear wheel for attachment to said shaft having a hub portion formed with an inner conical bore surrounding said shaft and with an external male thread, a conical shaped .split sleeve surroundingsaid shaft and having its outer conical surface in engagement with the inner conical bore of said hub and having an external male thread cut oppositely to the thread on said hub, and a clamping nut having female threads for engagement with the threads on said hub and sleeve for forcing said sleeve against said shaft and against the inner bore of said hub for locking said gear wheel to said shaft.

In witness whereof, we hereunto subscribe our names this 12th day of September, 1931. LOUIS J. J. SCHREIBER. GEORGES P. CHEVIGNY.

GEORGES X. LENS.

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