US2251635A - Telephone signaling apparatus - Google Patents

Description

Filed Jan. 14, 1957 2 Sheets-Sheet 1 INVENTOR. THEODORE C. RIEBE BY Z Z ATTORNEY.

FIG. 2

Aug 5, 1941. I RIEBE 2,251,635

TELEPHONE SIGNALING APPARATUS Filed Jan. 14, 1937 2 Sheets-Sheet 2 H 81 84 F|G.5 87 as v f7 18 F'IG.4

34 FIG.3 14

INVENTOR. THEODORE C. RIEBE BY A TTORNE Y.

Patented Aug. 5, 1941 TELEPHONE SIGNALING APPARATUS Theodore C. Riebe, Chicago, 111., assignor to Associated Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application January 14, 1937, Serial No. 120,508

4 Claims.

This invention relates to telephone systems in general, but more in particular to substation apparatus for signaling wanted telephone subscribers.

More specifically, the object of the present invention is to provide a pleasant sounding single stroke chime signal that operates directly from the regular telephone ringing current and which may be substituted for the well known vibrating type telephone ringer box to signal a wanted subscriber.

Another object of the invention is to provide a chime signal that can be used on either grounded or metallic telephone lines, having local or common battery telephones, in either automatic or manual telephone systems. In addition, a chime signal that may be used on individual lines or two-party divided ringing lines equipped with booster, anti-side tone, or series type telephone circuits and which may also be used as an extension signal for any of the above mentioned classes of service.

One feature of the invention relates to a new and improved musical chime mounting box containing all the apparatus comprising the substation telephone signaling equipment.

Another feature relates to a new and improved alternating current magnet actuated strike hammer, wherein the inertia, built up by a primary movement of the magnet armature, carries the striker hammer sufliciently beyond the actual stopping point of the magnet armature, to strike the chime bar of the unit a single sharp blow before receding, out of contact with the chime bar, to the point of maximum stroke of the armature.

A further feature relates to the means for mounting the alternating current magnet which practically eliminates any possibility of extraneous noises generated by the magnet and its armature from being transmitted to the mounting case.

Further features relate to the arran ement of mounting the tubular resonator and the chime bar, and the means for preventing the mounting case from functioning as a resonator.

Other novel features, not specifically pointed out, will be apparent from the following descriptic-n of the invention.

The accompanying drawings, comprising Figs. 1 to 5, inclusive, illustrate a preferred embodiment of the invention in which" Fig. 1 shows a general side view of the chime signal, portions being broken away to more clearly show the construction;

Fig, 2 shows a bottom view of the chime signal;

Fig. 3 shows a sectional view taken on line 3-3 of Fig. 1;

Fig, 4 shows an enlarged sectional view taken on line 4--4 of Fig. 1; and

Fig. 5 shows a circuit of telephone subscribers booster type telephone with a chime signal connected to a divided ringing party line in an automatic telephone system.

Throughout the drawings like reference characters denote like parts.

Referring now more specifically to the chime signal box and apparatus therefor, shown in Figs. 1, 2, 3, and 4. The base I of the box and the cover 2, which fits snugly on said base, are manufactured from synthetic resin or Bakelite. It is well known that Bakelite may be moulded into any desired shape, and that it retains its finish indefinitely because of its immunity to corrosion. The cover 2 is held in position on the base I by means of a pair of screws 3, which are threaded into holes provided in the base I. The base I may be mounted on a wall or other suitable support by means of screws in the holes 4. The pair of condensers 5 and 6, which are mounted on either side of the base I, are set in shallow cutout portions in the base, and are fastened there to by means of clamping brackets I and screws 8.

An induction coil indicated generally at 9, the spool heads of which likewise serve as terminal blocks, is fastened to the base I by means of studs III. The induction coil 9 may be similar to the induction coil disclosed in Patent 1,878,800, issued to H. F. Obergfell, September 20, 1932. A terminal strip II is fastened to the studs ID by means of screws I2. The groove I3 in the base I and likewise in the cover 2 permits entrance of the connecting leads extending from the desk set or telephone to the terminal posts (not shown) on the induction coil 9. The cut-out I4 in the base I, which extends from the top to the bottom of the base, permits the permanent line conductors and any other wires, such as a ground lead, to be placed so that the base I can be mounted flat against a wall or any other suitable mounting surface. The hole I5 in the base I permits entrance of the above-mentioned line conductors to the terminals on the terminal block II.

A chime bar I6, which is mounted on the cover 2 at the two points shown in Fig. l, is provided with mounting holes which are placed at the nodal points, so thatmaximum vibrations may be attained when the bar is struck. Fig. 4, which is an enlarged cross sectional view at line 4-4 of Fig. 1, shows the method of suspending the chime bar it at one of its nodal points, the mounting at the other point being exactly the same. It should be noted that the holes in the chime bar [6 are countersunk from each side so that when the bar is in contact with the rubber sleeve H there is very little or no damping effect encountered. In mounting the chime bar IS, the formed bracket 28, with its two soft rubber sleeves 2|, and the formed bracket 22, with 1-? its two soft rubber sleeves 23, are placed on the chime bar IS in the position indicated. The stud I9 is inserted through the hole provided in chime bar I6 and brackets 28 and 22 as it is threaded into nut I8.

The entire assembly including the chime bar and both its mountings are then mounted by inserting the studs 19 in the proper holes in the cover 2 and the nuts 24 lock the assembly to the cover. place on each of the studs 9. The chime bar i6 is now resiliently mounted at the nodal points, as a result of which, the vibrations of the bar are not damped.

The resonance chamber 25 consists of a tube closed at its ends and having a hole 25' midway between the ends. The resonance chamber 25 is fastened to mounting brackets 26 by means of screws 2'! and nuts 28. The assembly, including the resonance chamber 25 and mounting brackets 26, is placed so that the screws 27 are directly over the studs IQ of the chime bar mounting and is fastened to the cover 2 by means of screws 23 and nuts 30.

The alternating current magnet, shown generally at 3| is the same as the magnet disclosed in Patent 1,883,773 issued to John Erickson, October 18, 1932, modified slightly to mount the striker hammer 32. The general construction of the alternating current magnet is the same as i th above-mentioned patent except that in addition to the regular armature 33, an L shaped bracket 82 is riveted to the armature 33 by means of rivets 34. A spring member 35 is riveted to the L shaped bracket 32 by means of two rivets 36 (one of which is not shown). Attention is called to the fact that in order to provide the necessary space between the armature and magnet frame of the above mentioned Erickson magnet, to permit the L shaped bracket 32 to actuate to the full extent of the stroke of armature 33, metal spacer washers 54 are inserted between the armature mounting support 41 and the frame bracket 56. A portion of the U-shaped laminated core of the relay 3| is shown at 5T. hammer, which comprises a leather button 31 and metal hammer 38, is fastened to the spring member 35 by means of stud 39 and screw 48. The stud 39, which is riveted to the metal hammer 38 and fastened to the spring member 35 by means of screw 40, is mounted through a clearance hole 42 in the L shaped bracket 32. The tension of spring 35 is such, that the striker hammer assembly is lightly held against the L shaped bracket 32, but separated therefrom by the felt washer 4!. The felt washer 4| is provided to prevent the metal hammer 38 and the metal L shaped bracket from chattering when armature 33 of the magnet is actuated. The stationary terminal set, comprising contacts 42 and 43, is provided for terminating the coil wires of the magnet at the upper ends and external wires at the lower ends. The restoring spring 44 is provided to restore the armature 33 to its normal position when the magnet is deenergized.

A soft rubber sleeve IT is now slid in The striker P,

To provide a substantial mounting for the alternating current magnet assembly a yoke 46 is fastened to the magnet armature mounting bracket 41 by means of screw 48. At each end of the yoke 46 a soft moulded rubber cushion 45 is fastened by means of nuts 49. These cushions are provided with a threaded stud on each end, which are moulded in the rubber in such a manner that there is no metal to metal contact between the two studs, thereby providing a noise absorbing mounting for the magnet. One stud of the bottom cushion 45 (Fig. l) is threaded into bushing 50, which in turn is threaded into the magnet mounting frame 5!. The three cushions 45 are now fastened to the magnet assembly and the threaded studs on the opposite ends of the cushions are inserted into holes provided in the cover 2 and securely fastened thereto by means of nuts 52. It will be noted that the striker hammer 38 is centered in hole 53 in the cover and is within striking distance of the chime bar l6.

It will be noted by the construction of the striker mechanism described above that when the coil of magnet 31 is energized by a suitable source of alternating ringing current that the armature 33 will be attracted to the core of the magnet. When this occurs, the L shaped bracket 32, which is fastened to the armature 33, will thrust the striker hammer through the hole 53 in the cover 2, toward the chime bar H6. The magnet assembly is adjusted so that the L shaped bracket 32 is stopped, due to the fact that the armature 33 has been attracted the maximum distance of its movement, before the leather button 3'! of the striker hammer has struck the chime bar it. However, the momentum of the weight of the metal hammer 38, as it is thrust forward through the hole 53 by the L shaped bracket 32, is sufiicient to overcome the tension of spring 35 and permits the leather button 3'! to strike the chime bar [6 a single sharp blow. The momentum that carried the metal hammer 38 and the leather button 31' sufiiciently to strike the chime bar i6 is dissipated when the bar is struck and the tension of spring 35 is now strong enough to pull thehammer 33 back against the L shaped bracket 32. The L shaped bracket 32 remains in the operated position until the silent period of the ringing cycle is reached and the magnet deenergizes.

When the hammer 38 is restored against the bracket 32 by the tension of spring 35, the button 37 is out of engagement with the chime bar it. The tension of the armature restoring spring 44 is sufficient to restore the armature 33 to its normal unoperated position when the magnet deenergizes. This cycle of operation is repeated each time the magnet is energized.

When the chime bar [6 is struck by the button 37 of hammer 38 the chime bar is set to vibrating. The vibrations of the chime bar l6 are transmitted to the air column within the resonance chamber 25 through the opening 25. Due to the fact that the resonance chamber is tuned to respond to the frequency of the vibrations set up by the chime bar IS the musical tone of the chime bar is greatly amplified.

The cover 2 and mounting base I also form an air column which receives the vibrations of the chime bar l6 through the opening 53. The holes 55, two of which are drilled in each side of the cover 2, are provided to prevent the box from functioning as a resonator.

Fig. 5 shows a booster type substation telephone circuit of an automatic telephone system that is equipped with a chime signal for signaling a called subscriber. The equipment shown at the left comprising the switch hook H, receiver R, transmitter T, calling device CD and terminals 8l83, inclusive, are located in the subscriber's telephone desk stand. The equipment shown at the right comprises the induction coil 9, condensers and 6, the chime signal represented by the magnet 3| of the chime signal, and the terminals 8492, inclusive of the chime signal box. The leads connecting terminals 8|, 82, and 83 with terminals 84, 85 and 86, respectively, represent a three-conductor cord connecting the desk stand and the chime signal box. The half-circle shown at the ends of the various conductors in Fig. 5, represent space terminals soldered to wires which are connected by means of screw type terminals for convenience. Conductors 93 and 94, connected to terminals 81 and 92, respectively, are the line conductors extending the party line of an automatic telephone exchange.

In the particular embodiment shown in Fig. 5 the chime signal 3| is connected for divided ground ringing. Since the booster type substation telephone circuit is well known in the telephone art only that part of the circuit concerned with the signaling circuit will be described.

When the subscriber at the substation shown in Fig. 5 is wanted by another telephone subscriber, ringing current is intermittently transmitted, after the called subscribers number has been dialed, over line conductor 94, terminals 92 and 9|, winding of the chime magnet 3!, terminal 89, condenser 6, terminal 90, to ground. The chime signal magnet 31 energizes and strikes the chime bar each time the ringing current is applied to conductor 94, and restores to normal during the silent period of each ringing cycle. The wanted subscriber, upon hearing the pleasant tone of the chime bar, answers his telephone.

It should be clearly understood that the chime magnet can also be connected between terminals 81 and 89 when the subscribers ringing current is transmitted over conductor 93. In addition, when bridged or metallic ringing is employed the chime magnet 3| can be connected between terminals 88 and 9 l Condenser 6 and the ground connected to terminal 90 need not be used for bridged ringing because condenser 5 is now in series with the circuit of the chime signal magnet 3|.

Having described the invention, what is considered to be new and desired to have protected by Letters Patent will be pointed out in the following claims.

What is claimed is:

,1. In a signaling device, a mounting case carrying a striker mechanism, a chime bar, means for supporting said bar at" each of two nodal points including resilient cushions always in direct contact with the front and rear surfaces of said bar, said cushions contacting said bar only on a line with each of the nodal points, to prevent damping of vibrations when said bar is struck by the striker mechanism.

2. In a signaling device, a mounting case carrying a chime striker member, a chime bar supported on the case, said supporting means comprising two supporting brackets encircling said bar, soft rubber sleeves on said brackets in contact with the front surface of said bar, a formed bracket between said bar and each of said support brackets, soft rubber sleeves on said formed brackets in contact with the rear surface of said bar, said bar having mounting holes therein at each of its two nodal points, and a stud inserted through ach of said holes and each pair of said brackets, the sleeves on said bracketsresiliently preventing forward and backward movement of said bar and in contact with said bar only in line with said nodal points to prevent damping of the vibrations when said bar is struck by said striker.

3. In a chime bar mounting, a chime bar adapted to be struck by a striker mechanism, a base for mounting said bar said bar having a mounting hole at each of two nodal points, the said holes being countersunk on both sides forming a limited contacting area around the inside periphery thereof, two studs projecting from said base through said holes, resilient tubing encircling said studs of a diameter to contact the entire inside periphery of said mounting holes to thereby limit the lateral movement of said bar, and means including resilient cushions always in direct contact with the front and rear surfaces of said bar on a line only with said mounting holes to limit forward and backward movement of said bar.

4. In a chime bar mounting, a chime bar adapted to be struck by a striker mechanism, a base, said bar having a mounting hole for each of two of its nodal points, each of said holes being countersunk on both sides thereof forming a limited contacting area around the inside periphery thereof, two studs projecting from said base through said holes, brackets supported by said studs holding said bar a definite distance from said base, and resilient cushions on said studs contacting the entire surface of said limited periphery, and resilient cushions on said brackets always contacting the front and rear surfaces of said bar, all of said bracket cushions contacting said bar on a line only at said nodal points to prevent damping of vibrations when the bar is struck and to permit said base to be mounted in any position.

THEODORE C. RIELB-El.

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