End Of Message Unit For Use In Push To Talk Microphones

Abstract

An end of message unit is described for use in "push to talk" microphones. The unit is automatically cocked upon actuation of the microphone and an end of message signal is automatically provided when the microphone is deactivated. The end of message signal is stored on the periphery of a magnetic diaphragm which is employed both as the diaphragm of a microphone and as a disc in a disc recorder. A spring acts in conjunction with a viscous bearing to provide the drive and speed control for the disc during end of message signal generation.

Description

FIELD OF THE INVENTION

This invention relates to end of message units and particularly to an end of message unit in which an end of message signal is automatically transmitted each time a push to talk microphone switch or other "push to transmit" switch is deactivated.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 2,479,701 which issued on Aug. 23, 1949, and is entitled, Transmitting System, discloses a system in which an identifying message is transmitted automatically at the end of an information transmitting cycle. Therefore, the concept of automatically transmitting such an identification signal is known. The above-cited patent achieving its purpose by selecting and identifying a multiplicity of radio channels through coded call signals in order to achieve station to station communication among a multiplicity of stations. Said patent includes complex mechanical selecting apparatus and is not specifically an end of message identifier unit. Systems of the type and purpose described herein are most appropriate for police, taxicabs fleets, aircraft and marine radios where the necessity for oral identification by the operator is not only eliminated but anonymous transmissions are made impossible. A transmitter without this device is a fleet of transmitters so equipped will be conspicuous by its absence. The use of this device can aid in tracking down a stolen radio so equipped and will deter unauthorized transmissions or abuses of radio transmissions by the threat of disciplinary measures to the operator of the identified transmitter being used. Abuse of radio sytem operation is a problem in many radio communication system today.

In order for an automatic identifying system to be employed in commercial transmitting system, it is desirable to employ a device which is small enough to be incorporated within the average push to talk microphone without prohibitively increasing the cost of the overall combination. The output of the device must match the output of a normal microphone cartridge and should include as a portion thereof switching contacts for control of associated functions. The device must also operate over a wide range of temperatures without rendering the message transmitted unintelligable.

BRIEF DESCRIPTION OF THE INVENTION

A single producing device is provided in accordance with the teachings of this invention which meets the foregoing requirements. The signal producing device includes a housing, a recording member for storing information thereon on a predetermined portion thereof, the recording member bearing mounted for movement relative to the housing defining a path of travel for the predetermined portion thereof. A force is applied to the recording member to produce the relative movement while a predetermined coefficient of friction is maintain between the recording member and the housing thereby regulating the rate of relative movement. A sensing device is mounted on the housing adjacent the path for sensing information stored on the recording member during the relative movement.

In the preferred embodiment, the recording member is a disc of recording material which is mounted on an axle and the axle is mounted for rotation relative to the housing. The coefficient of friction is maintained by a viscous bearing mounted to resist relative rotation between the axle and the housing and, therefore, between the housing and the disc.

The preferred embodiment further indludes an actuation member mounted for movement between a first position and a second position. Electrical contacts are also provided responsive to the position of the actuation member.

In the preferred embodiment, the disc of magnetic material is mounted for rotation in response to a force applied in a first manner and to vibrate in response to the sound wave impinging thereon so that the magnetic pick-up device mounted on the housing adjacent to the disc responds to the vibration acting as a microphone and to signals stored on the periphery of the disc during rotation thereof, thereby also functioning as a magnetic recorder.

DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the invention, reference should be made to the following detailed description and drawings in which:

FIG. 1 is a cutaway view of a push to talk microphone housing having a signal producing device of this invention mounted therein;

FIG. 2 is a top view of the housing showing how actuation of the push to talk microphone actuates the signal producing device of this invention;

FIG. 3 is a side sectional view of a device constructed in accordance with the teachings of this invention;

FIG. 4 is an exploded view of the device shown in FIG. 3; and

FIG. 5 is a side sectional view showing the relationship of a transducer head to a diaphragm and cushion which is included in the device shown in FIG. 3.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring now to FIG. 1, we see a cutaway view of a push to talk microphone housing 10 having a device 11 in accordance with teachings of this invention mounted therein. A cable of electrical wire 12 brings leads from the device 11 to control a radio receiving and transmitting apparatus not shown. A push to talk button 13 is pivotly mounted by pin 14 in the housing 10 to activate and deactivate the device 11 as can be seen more clearly in FIG. 2.

In FIG. 2, we see the button 13 pivotly mounted on the housing 10 and the device 11 mounted therein. An actuation member 16 is pivotly mounted by a pin 17 and connected to the button 13 by a spring 18. The button 13 and the actuation member 16 are shown in their rest position in which a spring 19 urges the button 13 to rest a lip 21 thereof against a stock 22. In the rest position of the button 13, the spring 18 holds the actuation member 16 against the stock 23. In operation, the pressure of the button 13 moved the button 13 against the spring 19 rotating the button 13 until the spring 18 crosses the pin 17 rotating the actuation member 16 in a counterclockwise direction coming into forceable engagement with a force applying member 24 moving the same from a first position to a second position. Release of the button 13 allows the spring 19 to return the button 13 to its rest position, thereby moving the spring 18 back past the pin 17 drawing the actuation member 16 to its original rest position. Internal mechanisms in the device 11 thereupon return the actuation member 24 to its original rest position. It should be noted that the device 11 has a pattern of openings 26 on the front face thereof. The only requirement of this push to talk button is that it be of the snap-action variety. This construction was typical.

Referring now to FIGS. 3 and 4, we see the device 11 having a device housing 27 having the openings 26 passing therethrough and a back cover 18 which meets with and completes an enclosure for the device 11. A hub 29 is press fit into a recess 31 on an interior wall of the device housing 27. An axle 32 is mounted for rotation through the hub 29. A front portion 33 of the axle 32 extends through the hub 31 into a cavity 34 defined by the device housing 27 and the hub 29. A viscous material fills the cavity 34 providing a predetermined drag or coefficient of friction on the axle 32.

A disc 36 of magnetic recording material is affixedly mounted on the axle 32 for rotation therewith. An actuation member 37 is mounted in the device housing 27 laying in recesses 38 and 39 of the device housing 27 for slidable movement therein. The actuation member 37 has a cut out portion 41 to allow the axle 32 to pass therethrough. It can be seen that the disc 36 sets in the device housing 27 below the recesses 38 and 39 and therefore between the closed front portion of the device housing 27 and the actuation member 37. A cord 42 is wrapped about the axle 32 and connected at either end to opposite sides of the cut out portion 41 of the actuation member 37. A spring 43 connects the actuation member and adjustment pin 44 mounted for rotation in the back cover 28.

A pick up or recording head 45 is mounted in the device 11 adjacent to the disc 36 along a radius thereof. A pair of electrical wires 46 and 47 connect the magnetic pick up and recording head 45 to a pair of terminal posts 48 and 49 mounted in the back cover 28. Three electrical contact assemblies 51, 52 and 53 are also mounted in the back cover 28 to provide a single pole double throw switch in combination with conductive 54 mounted on a back portion of the actuation member 37.

In operation, the actuation member 37 is normally held by the spring 43 against the axle 32 in a first position which is shown downward in FIG. 3 and downward and to the left in FIG. 4. Referring now to FIGS. 1-4, we see that when the button 13 is depressed the member 16 pushes the actuation member 37 against the spring 43 to hold the other side of the opening 41 of the actuation member 37 against the axle 33. This movement occurs quickly (in about a 10th of a second) rotating the disc 36 and closing an electrical path between contact assemblies 52 and 53. The closing of the path between the contact assemblies 52 and 53 actuates a transmittor not shown. An operator of the push to talk microphone then speaks, therein in a normal manner, the sound waves passing through the openings 26 and impinging upon the disc 36 causing the disc 36 to respond to the sound waves. The movement of the disc 36 induces electrical signals in the pick-up 45 which is then conducted via leads 47 and 49 to the transmitting equipment not shown.

Release of the button 13 retracts the member 16 freeing the actuation member 37 to return to its rest position. The spring 43 urges the actuation member 37 towards its first position with a predetermined force while the drag or friction imposed by the viscous material 34 resists such movement so that the rate of movement of the actuation member 37 is determined by the characteristics of the spring 43 and the viscous material 34. In this embodiment, the values are chosen so that the actuation member 37 returns to its press position in approximately 21/2 seconds. The cord 42 causes the disc 36 to complete one complete revolution during the 21/2 seconds it takes the actuation member 37 to return to its rest position. A message is prerecorded on the periphery of the disc 36 so that pick-up head 45 provides an electrical signal in response thereto as the disc 36 completes its revolution. This prerecorded signal is the end of message signal provided each time that the button 13 is released. It should, of course, be noted that the transducer or pick-up head 45 can also be employed to put the prerecorded message on the periphery of the disc 36.

When the actuation member 37 returns to its rest position, the contact assemblies 52 and 53 are opened and the contact assemblies 51 and 52 are opened and the contact assemblies 51 and 52 have an electrical connection therebetween. In this state, the radio transmitter not shown will be de-energized.

Referring now to FIG. 5, we see a partial side view showing the pick-up head 45 and its relationship to a portion of the disk 36. The head 45 is mounted adjacent to the disc 36 opposite a pad 54 adhered to the device housing 27 (see FIG. 4). As can be seen in FIG. 5, the head 45 is mounted at an angle with respect to the disc 36 along a radius thereof. At the periphery of the disc adjacent the pad 54, the head 45 allows no gap between the disc 36 and itself. As the left hand end, further towards the center of rotation of the disc 36, a gap is provided between disc 36 and pick-up head 45 which allows movement of the disc with sound vibration of the diaphragm during normal microphone operation, while the direct contact is for transverse pick up when the information is taken from the periphery of the disc 36. The transducer 45 has a characteristically narrow gap over which the periphery of the disc 36 moves for the transverse pick up and a wider transducer gap towards the left hand portion thereof. The wider gap is bridged by an extra concentration of magnetic material on the disc and is spaced from the head to provide optimum transduction with vibration of disc 36. The pad 54 may be extended to an appropriate shape to supress spurious modes of vibration from the unused portion of disc 36.

It should be noted that while the device 11 has been described mounted in a push to talk microphone casing, it can be mounted in other locations for example, in the transmitter casing itself to be actuated by a solenoid in response to contact closures.

While this invention has been described with respect to a particular embodiment thereof, numerous other embodiments within the spirit and scope of this invention will become obvious to those of ordinary skill in the art in light thereof.

Claims

What is claimed is:

1. A signal producing device for use in microphones including:

a housing;

a recording member for storing information thereon on a predetermined portion thereof;

first means for mounting said recording member for movement relative to said housing; said movement of said member relative to said housing defining a path of travel for said predetermined portion of said member;

second means for applying a force to said recording member to produce said relative movement for a predetermined period of time;

third means for providing a predetermined coefficient of friction between said recording member and said housing thereby regulating the rate of said relative movement during said predetermined period of time;

fourth means mounted on said housing adjacent to said path for sensing said stored information during said relative movement, so that a signal is thereby produced for said predetermined period of time after said force is applied to said recording member by said second means.

2. The signal producing device as defined in claim 1, in which said recording member is a disc of recording material and said first means includes:

an axle;

fifth means for mounting said disc on said axle and

sixth means for mounting said axle for rotation relative to said housing.

3. The signal producing device as defined in claim 2 in which said third means includes a viscous bearing, mounted to resist relative rotation between said axle and said housing and therefore between said housing and said disc.

4. The signal producing device as defined in claim 3 in which said second means includes:

an actuation member mounted for movement between a first position and a second position with respect to said housing;

seventh means for connecting said actuation member to said axle to rotate said axle in response to relative movement between said actuation member and said housing; and

a yieldable member connected between said housing and said actuation member for urging said actuation member towards said first postition;

5. The signal producing device as defined in claim 4, also including:

a first electrical contact mounted on said housing;

a second electrical contact mounted on said housing; and

conducting means on said actuation member to make and trade electrical continuity in response to the position of said actuation member.

6. The signal producing device as defined in claim 5 in which said housing has a plurality of holes therethrough and through which said disc may be sound actuated from external sources.

7. The signal producing device as defined in claim 6 in which said fourth means extends from the periphery of said disc towards the center of rotation thereof and the space between said fourth means and said disc increases from said periphery towards said center of rotation.

8. A signal producing device including:

a housing;

a disc of magnetic material;

means for mounting said disc of magnetic material for rotation in response to a force applied in a first manner and to vibrate in response to sound waves impinging thereon; and

a magnetic pick-up device mounted on said housing adjacent to said disc to provide a signal representation of magnetic information stored on said disc in response to rotation thereof and to the vibrations of said disc in response to sound wave impingement thereon thereby serving the dual function of both a magnetic recorder and a microphone.

9. The signal producing device as defined in claim 8, in which said magnetic pick-up extends from the periphery of said disc towards the center of rotation thereof and the space between said magnetic pick-up device and said disc increases from said periphery towards said center of rotation.

10. The signal producing device as defined in claim 8, also including;

means for applying a force to said recording member to produce said rotation.

11. The signal produce device as defined in claim 10 also including;

means connected to said disc mounting means for providing a predetermined coefficient of friction between said disc and said housing thereby regulating the rate of said rotation.

12. The signal producing device as defined in claim 11, in which said coefficient of friction producing means includes a viscous bearing which resists said rotation.