Description:
This invention relates to a device for automatically answering telephone calls. More specifically this invention relates to such an answering device which is used with a magnetic sheet of belt-type dictating machine.
The dictating machine with which this invention is used contains a cylinder driven by an electric motor. The drive for the cylinder has a magnetic clutch and the cylinder is adapted to receive a recording medium which may be a magnetic sheet (sometimes called a foil) or a magnetic belt. The machine has a sound head carriage, which carries a sound head. This sound head carriage can be guided parallel to the cylinder and can be displaced, or moved, by a drive to an end position at the end of the cylinder and is connected with an electrically operated return device to provide for the stepwise return of the carriage to the front end of the cylinder. Furthermore, the machine has an amplifier which is connected to the sound head, to a microphone and to two limit switches. Both of these limit switches are adapted to be actuated by the sound head carriage. The first limit switch can be moved between the sound head carriage and the end of the cylinder by hand. The second limit switch is arranged in a fixed position ahead of the front end of the cylinder and is adapted to be actuated by a return element. The second limit switch, the return element, the cylinder and the sound head carriage cooperate, during the return of the carriage in such a way that the second limit switch is returned to its rest position after the carriage is returned and the cylinder and the sound head carriage are reset to their starting position.
Usually, when magnetic sound recording devices are used for automatically answering telephone calls, the amplifier output of the device is switched to reproduction, i.e. playback by a call signal which is received by a telephone connected to the device. Then a recorded message is transmitted to the telephone line to answer the call. After the call has been as answered, the sound head and the magnetic recording medium are automatically returned to the starting position and the telephone line is disconnected, i.e. made ready to receive another call. The answer to the call must be selected so that it is completed within the time period during which the amplifier output is connected. In some cases a tape recorder is also connected to the answering device for recording a message transmitted by the caller over the telephone line. The answer to the call and the message of the caller must then be completed within the given time. In order to adapt the answering device better to its respective operation, whether it is used for answering calls only, or for both answering calls and for recording the message of a caller, the time setting frequently is effected in steps, i.e. increments. The shortest time step or increment can be selected. However, in these type devices, the telephone line remains busy for the entire incremental time set, even if the answer is completed sooner than the time allowed, i.e. in less time than is allotted by the one or more steps.
The object of the invention is to provide a device for automatically answering telephone calls with a magnetic sheet or belt-type dictating machine in which the sound head of the machine is returned to its start position immediately after the answer recorded on the recording medium, no matter what is its length, has been transmitted and the telephone line is released immediately after the sound head, and the cylinder carrying the recording medium, are reset to the start of the recorded answer.
The device according to the invention is characterized by the face that an output of a release member, which is connected with a magnetic clutch of the dictating machine drive, leads also to matching-and-holding circuit, and the electrically operated return device for the sound head carriage is controlled by two limit switches. The return device is connected when the first limit switch is actuated and is disconnected when the second limit switch is actuated. This operation is accomplished in such a way that the release member holds the telephone line to the amplifier output by means of the matching-and-holding circuit when a call signal arrives, and, at the same time, couples the cylinder through the magnetic clutch to its drive. Then, after the call is answered, or after the call is answered and a message by the caller is recorded, and the sound head carriage is returned to its starting position, the release member releases the matching-and-holding circuit and, after the second limit switch returns to its rest position, the cylinder is uncoupled from its drive.
To provide for the return of the sound carriage the electrically operated return device can be connected to an astable multivibrator. An electronic switch, controlled by the second limit switch, can be connected in series with this astable multivibrator. A switch, which is actuated by this electronic switch and which separates the amplifier output from the matching-and-holding circuit during the return of the sound head carriage to its starting position, can be connected into the amplifier output line leading to the matching-and-holding line.
The first limit switch can be connected to the electronic switch through a switch, and the second limit switch can also be connected through a switch to both the electronic switch and to the release member. Additional switches for operationally engaging the answering device can be connected into the lines between the telephone terminals and both the mate matching-and-holding circuit and the release member, between the amplifier output and the matching-and-holding circuit, and between the release member output and the magnetic clutch.
All these switches can be engaged for operation by a single control. Finally, the matching-and-holding circuit, the release member, the astable multivibrator with the electronic switch, and the switches with their operating control can be installed in the housing of the magnetic-sheet-type dictating machine.
An embodiment of such a device for automatically answering phone calls is represented in the attached drawing in which:
FIG. 1 shows schematically a front elevation of a magnetic-sheet-type dictating machine, with its cover removed to illustrate the parts beneath, having a telephone responder arrangement embodying the invention;
FIG. 2 shows, in section, a top plan view of the front parts of the dictating machine shown in FIG. 1;
FIG. 3 shows a partial section along the line III-III in FIG. 2; and
FIG. 4 is a block diagram of the circuit used in the device for automatically answering phone calls represented in FIG. 1 through 3.
In the magnectic-sheet, or foil-type, dictating machine represented in the drawing, two bearing blocks 2a and 2b are mounted in a housing bottom 1. These blocks carry a shaft 3 with a cylinder 4 into which is inserted the reinforced upper edge of a magnetic sheet 5. The sheet merely is placed around the cylinder without being secured to it, other than by its edge engaged in the slot.
The cylinder 4 is driven by an electric motor (not shown in the drawing). The motor drive is connected through a friction wheel gear and a magnetic clutch 67, of which only the wheel gear 6, secured on the cylinder shaft 3, is represented. A guide 8, extending parallel to the cylinder shaft, is secured in the two bearing blocks 2a, 2b. A sound head carriage 9, carrying a sound head 10, is mounted for displacement, i.e. to slide, on this guide 8. This dictating machine is provided with a driving spindle 11, mounted at both ends for rotation in the bearing blocks 2a and 2b. This spindle is for moving the sound head carriage into the end position at the rear end of the cylinder. Spindle 11 is driven by the cylinder shaft 3, acting in cooperation with appropriate linkage, for example, with a cam belt 13 and cooperating pulley, or wheels 13 and 14, each respectively attached to the cylinder shaft ad and the spindle. When the cylinder turns, the driving spindle likewise turns and displaces the sound head carriage which is coupled to it. The cylinder, and, hence, the spindle turn in one direction only, i.e. the feed direction, because if the cylinder were allowed to turn in the opposite direction, the magnetic sheet, held only by its end inserted in the slot in the cylinder, would come loose from the cylinder and become damaged.
In the dictating machine shown, the sound head carriage 9 comprises a frame 15, which is displaceably, i.e. slideably, mounted at its upper end on the guide 8. The sound head 10 is engaged in the frame under a spring load. Side parts 15a extend towards the front of the machine and their ends are connected by a pivot 20, extending parallel to the guide 8, on which is rotatably mounted a key 19. Guide parts 22 and 23 are provided to hold the key for displacement in a vertical direction only. The frame 15 is tilted about the guide by pressure on the finger support, or fingerpiece, 21 of key 19.
As can best be seen in FIG. 1, a stirrup 16, having a straight center part extending parallel to the spindle 11, is mounted at both its ends to rotate in the bearing blocks 2a, 2b. The portion of the sound head carriage frame 15 which extends behind the spindle 11, between the spindle and the cylinder (see FIG. 3), has at its bottom a crossbar 42 which is attached to the stirrup 16 by a U-shaped coupling part 43 mounted on the center part of the stirrup 16. The frame of the sound head carriage can be tilted by tilting the center part of the stirrup 16 towards the cylinder which causes the sound head carriage to tilt about the guide 8.
The bottom crossbar 42 of the sound head carriage frame 15 has a carrier level 44 mounted for rotation which is represented for sake of clarity only schematically in FIG. 3 This carrier lever 44 has at each of its ends a comb, or series of ridges, for engaging the thread of the spindle. This stirrup 16 is urged by a spring toward the spindle 11 so that each comb on the carrier lever engage the thread of the spindle. When this happens, the sound head carriage is displaced by the spindle 11 when it rotates. To move the carriage back, a spring (not shown) urges one end of the carrier lever toward the spindle. The other lever is associated with a stop so that, when the sound head carriage frame 15 is tilted about the guide 8, the comb at the stop end of the lever is disengaged from the spindle thread. When the frame is further tilted, the other comb is likewise lifted from the spindle the thread, Then, when the frame 15 swings back, since the fulcrum of the carrier lever is further away from the spindle than it is when the frame 15 is in its rest position, the comb, advanced by the spring, engages the thread of the spindle in such a way that the top of a descending flank of a comb tooth strikes the top of an ascending flank of a turn of the spindle thread. When the frame 15 is tilted back completely into its rest position, the two flanks glide on one another and the sound head carriage is pushed back by one turn of the spindle thread, that is, by one sound track.
The driving device for the stirrup 16 consists of a magnet coil 17 (see FIG. 2) which surrounds an armature 18. This armature is adapted to cause the stirrup 16 to be pulled backward when the coil 17 is engaged. Current impulses can be fed to the magnet coil 17 by a control on the microphone, so that with each current impulse fed to the magnet coil, the stirrup 16 is tilted, against the action of its return spring away from the carriage by the armature 18 to effect the return of the sound head carriage.
A "correction slide" 26 is arranged as shown on the guide 8 between the sound head carriage 9 and the rear, i.e. the right of the cylinder. This "correction slide" 26 can be adapted so that it can move, i.e. slide, easily along the guide, but cannot be turned, i.e. pivoted, about it. This slide has a pair of normally open contact springs 31 and 32 which are adapted to be actuated by the sound head carriage. The use and connections of these contact springs, which comprise a first limit switch, will be described in detail below.
A second limit switch, likewise consisting of a pair of normally open contact springs 45 and 46, is arranged at the end of the return path of the sound head carriage. This second limit switch 45 and 46 can be actuated by a return pawl 50 when the pawl is acted upon by the sound head carriage. The return pawl 50 is mounted for rotation and displacement transverse to the cylinder shaft on a projection 49 which extends from the bearing block. It has a nose, or extension 53 at its front end which fits into an opening 54 in the front frame part 15a when the sound head carriage is moved to the extreme front end of the cylinder, i.e. to the far left hand side of the cylinder as viewed in FIG. 1 and 2.
When the sound head carriage is moved to the extreme left and the pawl nose 53 is caused to be engaged in the opening 54, the nose 53 of the pawl is caused to push the sound head carriage to the front, i.e. to the right, into a starting position. For this this positioning of the sound head carriage by the pawl 50, the other end of the pawl, i.e. the end opposite the end with the nose 53, is provided with a hook 57 which is contacted and then displaced by a return cam 58 which is secured on the front face, i.e. the front end wall, of the cylinder. When the sound head carriage 9 is moved to the extreme left and the cylinder 4 turns, the return cam 58 strikes against the hook 57 and the pawl is displaced in the direction of motion of the cylinder causing the sound head carriage to slide to the right along the inclined edge of the nose 53. The carriage thus is displaced by the pawl until the nose slips from opening 54 and the pawl is released. In this manner the carriage is set in its starting position.
A journal 62, secured vertically in a bearing block part 49, protrudes through an oblong slot 61 in the pawl 50. A return spring 52, secured to the journal 62, holds the pawl 50 in its rest position. The oblong slot 61 is designed so that the return cam 58 secured to the rotating cylinder is able to move the pawl 50 by its hook 57. First, the hook is moved to the rear and then, when a certain cylinder position, i.e. the starting position, is reached, it is moved to the left so as to disengage the hook from the cam. When the hook is disengaged, the pawl is able to return to its rest position and the pair of contact springs 45 and 46, which have been closed until then, can spring open. This pair of contacts 45 and 46 is connected to the signal supply line for the magnetic clutch 67 and also to the magnet coil 17.
When the contact pair 45 and 46 is closed by the returning sound head carriage 9, both the magnetic clutch 67 and the magnetic coil 17 receive current to engage the clutch and to operate the stirrup 16. The cylinder, coupled to its drive, through the magnetic clutch, starts to turn. At the same time the stirrup 16 is pulled back so that the carrier lever 44 is lifted from the thread of the driving spindle. Then, after the pawl 50 is released and the pair of contact springs 45 and 46, i.e. the second limit switch, is opened, the magnetic clutch and magnet coil 17 deenergize simultaneously. The cylinder then stops rotating and remains in its starting position, into which it has been pushed as described above, and the sound head carriage 9, now also in its starting position, is again coupled to its driving spindle.
FIG. 4 shows schematically a block diagram of the telephone answering device circuitry for this magnetic-sheet-type dictating machine. In this diagram only certain of the dictating machine parts are represented.
For example, socket (not shown) for connecting a telephone 68 is arranged in the rear wall of the housing bottom 1. This socket is connected to the input terminal 75 of the circuit shown FIG. 4. These terminals 75 are connected by the switches 81 to a matching-and-holding circuit 70 is and to a release member 69. This matching-and-holding circuit 70 is of the conventional type. When connected, it transmits the sound signals emitted by received amplifier 72 to the telephone line, and holds the line until it is to be disconnected. The release member 69, which is likewise of known design, is used to control the matching-and-holding circuit 70. When a call signal arrives, the release member signals the matching-and-holding circuit and the call signal is held until an off-signal appears at the input 82 of release member 69. The output 83 of the release member 69 is connected through a switch 80 to the magnetic clutch 67 for the cylinder drive. When the switch 80 is closed, the magnetic clutch 67 is controlled by the release member only, that is, when switch 80 is closed and a call signal arrives, the cylinder is set in rotation by the call signal and stops only when the release member is disconnected and the magnetic clutch is allowed to deenergize.
The feeding of the magnet coil 17 with current impulses to return the sound head carriage 9 is achieved by using an astable multivibrator 73. For connecting and disconnecting this multivibrator 73 with the coil 17, the multivibrator is connected in series with an electronic switch 74, for example, a thyristor. This electronic switch 74, and, thus, the astable multivibrator 73, are turned on by the contact springs 31 and 32, i.e. the first limit switch, which is actuated by the sound head carriage at the end of its advance path. When these contacts 31 and 32 are closed, the magnet coil 17 receives current impulses from the multivibrator 73. The stirrup 16 is attracted with each current impulse and then is pulled back each time into its rest position by the return spring. This movement of stirrup 16 causes the sound head carriage 9 to move back in steps to its starting position in accordance with action previously described. An amplifier 72 is connected to the sound head 10. A switch 77, connected into the output line 84 of this amplifier, is actuated by the electronic switch 74. When the electronic switch 74 is in its rest position, the switch 77 is closed. When the return device for the sound head carriage is started, the switch 77 opens and disconnects the matching-and-holding circuit 70 from the amplifier output. The limit switch 31 and 32 is connected to the electronic switch 74 by a switch 78. In one position of the switch 78, the limit switch 31 and 32 is connected to the electronic switch 74. The other position, the switch is tied into the control circuit of the dictating machine so that, when the limit switch 31 and 32 is actuated, the dictating machine is switched from recording to reproduction This second position of the switch 78 is used only when the machine is being used for dictation.
The second limit switch 45 and 46 located at the end of the return path of the sound head carriage 9 is also connected through a switch 79 to the electronic switch 74 and the the release member 69. When this second limit switch 45 and 46 is actuated by the sound head carriage 9 after it is returned, the astable multivibrator 73 is disconnected by the electronic switch 74 so that the sound head carriage 9 is not further. The closing of the second limit switch 45 and 46 is achieved, as mentioned above, the carriage 9 pushing the return pawl 50 into the spring contact 46. When this limit switch is closed, the pawl carrier hook 57 is pushed into the path of motion of the return cam 58 which rotates with the cylinder 4. The cylinder continues to turn until the cam 58 strikes and displaces, i.e. pulls back the carrier hook 57 causing the nose, or extension, 53 of pawl 50 to urge the sound head carriage 9 into its starting position. During the further rotation of the cylinder, the carrier hook 57 is pushed to the side and is detached from the return cam 58. The pawl 50 then springs back into its rest position, as described above, and the limit switch 45 and 46 springs open. When the limit switch 45 and 46 us opened, the release member 69 is disconnected. With no signal through its output 83, the magnetic clutch 67 for the cylinder drive is deenergized, stopping the cylinder in its starting position, and the matching-and-holding line 70 is deactivated, so that the telephone line is released. The device is thus made ready to receive another call.
In one switching position, switch 79 connects, as indicated above, the second limit switch 45 and 46 to the electronic switch 74 and to the release member 69. In the other switching position, this second limit switch 45 and 46 is connected through diodes 85 and 86 to the magnet coil 17 to provide for the return of the return of the sound head carriage 9. In this second position, it is also connected to the magnetic clutch 67 to provide for the drive of the cylinder. When the switch 79 is in this second switching position and the limit switch 45 and 46 is actuated by the sound head carriage 9, the return of the sound head carriage 9 is stopped and the cylinder 5 is coupled with its drive. This second position of the switch 79 is used only when the machine is being used for dictation. It is not used for answering phone calls.
The magnet coil 17 and the magnetic clutch 67 can also be actuated by the control in the microphone. The diodes 87, 88, and 89 are used to separate the microphone from the telephone responder circuit.
The matching-and-holding line 70, the release member 69, and the astable multivibrator 73 with its switch 74 advantageously are mounted, together with the necessary switching elements, on a support plate. Thus, the telephone responder is designed as an optional unit to be installed in a magnetic-sheet-type dictating machine which is adapted to receive it.
The switches 76, 78, 79, 80 and 81 in the output line of the amplifier 72, the respective connecting lines for the first and second limit switch 31 and 32 and 45 and 46, the connecting line for the magnetic clutch 67 and the connecting lines for the telephone socket 75 are arranged in a relay block and are engaged for use by a common control button 90 (see FIG. 2).
In addition to this control button 90 for "answering phone calls," the machine has additional control buttons to switch it for use for normal dictation operations and for recording telephone calls. When a control button is actuated, the corresponding circuit connections are established and the machine is connected. The disconnection of the machine is accomplished by an "off" key.
For answering calls, the control for normal dictation is actuated first. With a foil inserted, the sound head carriage is returned, i.e., moved to the left, by hand or by actuating the return control on the microphone until the second limit switch is actuated and the cylinder an the sound head carriage are moved into starting position. The message is then recorded on the magnetic sheet. At the end of the message the cylinder drive is uncoupled by actuating the control on the microphone.
The "call answering key" 90 is then pressed, so that all necessary circuit connections are established. The "correction slide" 26 is then moved on the sound head carriage next to the sound head carriage, and is left in the this position. From this stage on the machine works fully automatically. After the "correction slide" 26 is moved, as described above, next to the sound head carriage, the first limit switch 31 and 32 closes and the sound head carriage and the cylinder are moved into their starting position, that is, to the position where the recording on the magnetic sheets starts. When a call signal arrives, the carriage moves and the message is reproduced and transmitted over the telephone line. At the end of the message, the sound head carriage and the cylinder are automatically returned, as described previously, to their starting position. When this starting position is achieved, the telephone line is released for another call.
An important advantage of this answering device is that the person telephoning receives the recorded message immediately after his call is recieved. There is no waiting period before the recorded message starts, which frequently gives rise to misunderstandings. Also, the recorded message is not restricted to a predetermined time period which may be longer or shorted shorter than necessary for the message desired. The message transmitted by this device can be as long or as short as desired, and the telephone lines is held only for the duration of the message (plus the time required for returning the sound head carriage to its starting position). Furthermore, the answering device of this invention is advantageously designed so that it can be added to a dictating machine adapted to receive it. This represents and important economical advantage.