US2302081A - Signaling system - Google Patents

Description

Patented Nov. 17, 1942 SIGNALING SYSTEIW Otto Weitmann, Binghamton, N. Y.-, assignmto International Business Machines Corporation, New York, N. Y., a corporation of New York Application June 19, 1941, Serial No. 398,720

Claims.

This invention relates broadly to signaling systems, and more specifically to means capable of initiating groups of control impulses upon the sensing of perforations in a control ,gheet or tape.

The present invention is particularly applicable to printing telegraph systems or similar systems wherein perforated tapes or sheets are utilized for controlling impulse initiating circuits,

An object of the present invention resides in the provision of an improved sensing means for analyzing a perforated sheet and initiating control impulses whenever the perforations are presented to a sensing station.

Another object resides in the provision of impulse initiating means comprising piezo-electric devices and associated means for applying mechanical vibrations to the said devices whenever perforations in the sheet are encountered.

Another object resides in the provision of perforated sheet analyzing means wherein vibrating means are associated with the piezo-electric devices which when set into operation vibrate at selected frequency rates thereby causing the said devices to initiate control impulses at corresponding frequency rates. I

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawing, which discloses, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawing:

Fig. 1 shows diagrammatically the tape advancing means, sensing members and a related piezo-electric device and associated control circuits.

Fig. 2 is a circuit diagram embodying the piezo-electric devices as controlling elements.

Fig. 3 shows diagrammatically a modified arrangement of the piezo-electric device.

Fig. 4 is a circuit diagram showing a modified application of the piezo-electric devices.

Referring now to Fig. 1, the perforated sheet III to be analyzed is shown, for illustrative purposes, to be the well known type of perforated tape employed in printing telegraph systems. The perforations are usually formed in various combinations, in transverse rows, in accordance with a combinational code, such as the Baudot code. Suitable tape advancing means are diagrammatically shown in the form of a motor with the associated feed rollers, indicated generally by the reference character It Disposed beneath the tape, and in close proximity thereto, are the individual piezo-electrlc devices II. An individual piezo-electric device is provided for each column of perforations formed in. the tape, which for telegraph purposes, is usually five or six columns. Each piezo-electric device l2 consists of a piezo-electric crystal carried in a suitable mounting l3, one end of which is provided with a projecting member l4. Disposed above the tape are individual spring urged arms [5, one for each piezo-electric device.

As the tape is advanced to present the perforations to the sensing station, each corresponding arm i5 is urged in a counterclockwise direction causing the tip of arm l5 to deliver a sharp blow to the projecting member H, which in turn causes a mechanical pressure to be applied to the piezo-electric crystal through the mounting l3. As is well known, upon receiving a mechanical shock of this type, the piezo-electric crystal is capable of converting the mechanical pressures or vibrations into electrical vibrations or impulses.

Each piezo-electric device is connected-to the input circuit of a cold cathode gaseous discharge device l6, known in the art as a cold cathode starter anode type. One terminal of the piezoelectric device is connected through resistor ii to a suitable point on the resistor l8, which, in

turn, is connected across the power supply. The other terminal is connected to the starter anode IS. The cathode element 20 is connected to one terminal of the power supply and resistor l8, and the anode element 2! is connected to coil of relay Rl, normally closed contacts 23, and the other terminal of the power supply and resistor IS. The voltage normally impressed across the starter anode and cathode elements, by means of said supply through resistors l1 and I8, is of such value. as to be slightly less than the tripping voltage required for the cold cathode device.

Now, upon sensing of a perforation, or perforations, the arm or arms l5 are effective to apply mechanical shocks to the corresponding piezoelectric devices to generate electro-motive forces accordingly. These generated electro-motive forces when impressed upon the respective input circuits of the cold cathode devices are suflicient to effect the tripping of the devices, and thus render them conductive. As shown, in Fig. 1, each output circuit of each cold cathode device, includes the coil of an electromagnetic device, for example, relay RI, which is energized, when its related device is rendered conductive.

To continue further with an exemplary application of the present sensing system, refer now to Fig. 2, wherein the piezo-electric units and related gaseous discharge devices and associated circuits are shown diagrammatically and indicated by the reference characters l2 and I6 respectively; and wherein the individual contacts Rla to Ria of the relays Rl to R are connected to the individual conducting segments 29 of a well known type of start-stop distributor. The distributor briefly comprises the said conducting segments 29, brushes 30 which when released engage successively the said segments and connect them to the common conducting strip I, which in turn can be connected to any suitable transmission terminal or medium.

As is well known, normally the brushes are held from rotating, under control of the latching magnet 32, which is shown connected to the output of one of the gaseous discharge devices, which in turn is connected to a piezo-electric unit designated 120:. Each time a row of perforations is presented to the sensing position, the arm i5a senses a perforation which is provided on the tape for each row of perforations presented thereto, in order to set the related piezoelectric unit 1 2a into operation. In this manner, it is seen that the magnet 32 is energized each time a row of perforations is presented to the sensing position, to release the brushes 30. As mentioned, the brushes 30 traverse the con ducting segments 29 progressively to initiate signals at differential times, depending upon which contacts of the group Rla to R5a are closed during the signaling cycle.

(Jam 25 is suitably secured to the start-stop shaft carrying the rotatable brushes 30, and is arranged to open the contacts 23, momentarily, near the end of each signaling cycle to render the operated gaseous discharge devices 16 nonconductive, and thus restore the system to the normal condition shown. The rate of advancing the tape is adjusted so that the brushes can complete one revolution, or stated in other words, so that a signaling cycle can be completed before another row of perforations ispresented to the sensing position. It should be stated too that contacts 32a are provided to render the gaseous discharge device, connected to the piezo-electric unit l2a, non-conductive each cycle. These contacts are opened, each time the magnet 32 is energized to disconnect the power supply connected to this discharge device. Numerous other applications, of course, will become evident to those skilled in the art, for the described sensing means.

For example, with reference now to Figs. 3 and 4, the projecting member H of each piezo-electrio unit is shown connected to an elongated spring armature 26, which when actuated by the related spring urged arm 15, is effective to vibrate at a predetermined frequency; which vibrations are transmitted by the mountings l 3 to the piezoelectric crystal, the latter, in turn, generating electro-motive forces of a corresponding frequency.

Assume now, that the individual armatures 26 are adjusted and arranged to vibrate, when set into operation by virtue of the sensing of perforations in the tape ill, at frequencies fl, {2,

f3, and in, respectively, to effect generation of electro-motive forces of corresponding frequencies, by the related piezo-electric units [2.

These generated electro-motive forces are then delivered to a suitable type of wide band" amplifier unit 2'! which will amplify all of the electro-motive forces of different frequencies.

Individual filter circuits Ill, fi2, H3, and fin are provided and suitably connected to the output circuit of the amplifier unit, as indicated in Fig. 3 which filter circuits are tuned so as to be responsive to only one frequency of the group impressed upon the amplifier unit. In this manner, the amplified oscillations of different frequencies are impressed upon the individual coils of relays or magnets RI, R2, R3 and Rn connected to the individual and related filter circuits. The associated relay contacts can then be connected to any suitable work circuit desired. It is obvious, of course, that the generated oscillations of different frequencies can be impressed directly upon any desired transmission medium, and impressed upon suitable filter circuits at a distant station to energize the windings of electromagnetic devices, such as those indicated RI, R2, R3 and Rn, which for illustrative purposes, could readily represent the selecting magnets of suitable and well known types of printing telegraph receiving units.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modifica tion, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operations may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. Apparatus for sensing perforated sheets and initiating control impulses comprising means for feeding a perforated sheet, individual means for sensing the perforations in said sheet, individual piezo-electric means, and means controlled by each of said sensing means for controlling the related piezo-electric means for effecting the initiation'of control impulses whenever perforations are sensed in said sheet.

2. Apparatus for sensing perforated sheets comprising means for feeding a perforated sheet,

individual means for sensing the perforations in said sheet, individual piezo-electric means, and means controlled by each of said sensing means for controlling the related pieZo-electric means for initiating control impulses whenever perforations are sensed, individual electric discharge means, one for each piezo-electric means, means responsive to the impulses initiated by the related piezo-electric means for controlling the related electric discharge means, and means controlled by the said electric discharge means.

3. Apparatus for sensing perforated sheets comprising means for feeding a perforated sheet, individual means for sensing the perforations in said sheet, individual piezo-electric means, means controlled by each of said sensing means for controlling the related piezo-electric means for initiating control impulses whenever perforations are sensed, individual cold cathode gaseous discharge means, one for each piezo-electric means, said gaseous discharge means being normally non-conductive, means for impressing the initiated impulses upon the related gaseous discharge means for rendering the latter conductive, and means controlled by the conductive gaseous discharge means.

4. Apparatus for sensing sheets having columns of coded data designations comprising means for feeding a control sheet, individual means, one

for each column of data designations, for sensing the said data designations on said sheet,

individual piezo-electric means, and means controlled by each of said sensing means for controlling the related piezo-electric means for generating control impulses uponthe sensing of data designations in the said columns on said sheet.

5. Apparatus for sensing perforated sheets, comprising means for feeding a perforated sheet, individual means for sensing the perforations in said sheet, and individual piezo-electric means,

one for each sensing means, each of said piezoelectric means including a vibratory member, each vibratory member adjusted to vibrate at a different frequency rate and set into operation by the related sensing means upon the sensing-of the perforations in said sheet, and individual means controlled by the vibratory members for causing the related piezo-electric means to generate control impulses at varying frequency 1 rates.

OTIO WEITMANN.

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