US1942588A - Telegraph regenerative repeater - Google Patents

Description

Jan. 9, 1934. E. P. BANCROFT TELEGRAPH R EGENERATIVE REPEATER Filed Feb. 6, 1932 2 Sheets-Sheet 1 FIG. 3

INVENTOR ERWIN P. BANCROFT BY 60/ ATTORN Jan. 9, 1934. E, BANCRQFT 1,942,588

TELEGRAPH REGENERATIVE] REPEATER Filed Feb. 6, 1932 2 Sheets-Sheet 2 INVENTOR ERWIN R BANCROFT BY f ATTORN Y Patent No. 1,229,201.

Patented Jan. 9, 1934 UNITED STATES PATENT OFFICE i,942, 5 ss TELEGRAPH REGENERATIVE REPEATER Erwin 1?. BancrofLBrooklyn, Y., assignor, to International Communications Laboratories, Inc., Newark, N.J., a corporation of New York Application February 6, 1932. SerialNc. 591,324

5 Claims. (o1.'178 70) My invention relates to improvements in regenerative repeaters in which a single set of elements is used to regenerate successively the individual elements of each signal.

The device may be used to regenerate signals in start-stop systems and in systems in which ing drawings, wherein:

Fig.1 shows a start-stop regenerative repeater;

Fig.2 shows a repeaterin which continuous synchronism and correction is maintained; and

Fig. 3 shows the differential gearing in connection with the corrector. I

In Figsl and 2 the transmitting ,stationiis representedfatX and is equipped with the usual transmittercomprising a distributor of the type well known in the art and it is not thought necessary to illustrate the mechanism. The station ..Y is equipped with the usual printer mechanism which responds to the retransmitted impulses and it is not thought necessary to illustrate such mechanism.

Referring to Fig. 1, shaft 5 carrying a toothed .cam 4 is arranged .to make one revolution for 35,

each received code signal. Shaft 5 is started and stopped under control of impulses preceding and following each code signal by any suitable means such, for example, as the well known start-stop clutch mechanism described in United States Patent No. 1,205,248, or the single magnet mechanical distributor disclosed in United States Power for operating the shaft may be furnished from any suitable source, such as a constant speed electric motor or the like.

, The teeth on cam 4 are arranged at definitely spaced intervals around the circumference .of the cam and correspond in number to the impulses of each code signal, including the start andstop impulses. It is arranged to be driven in synchronism with the incoming signals, One short segment (or the stop position) is sfuchthat the length of time representedby the short segment, plus the normal stop time of the shaft, represents one signalling impulse.

Lever3 pivoted at 13 is arranged to be oscillated by cam 4 through the action of a tooth 15 carried ,by lever 3 and"a spring 3. A bifurcated lever 2 is pivoted on the lever 3 opposite the pivot end 13 and oscillates with lever 3. A pin 12 carried by lever'2 slides in a slot 11 inthe end of armature 10f relaylO. Armature 1 is pivotedat 1'. Relay 10 is shown schematically polar relay, such as is shown in Fig. 2.

Located adjacent and immediately above the bifurcated ends of lever 2 is a three-arm lever 6 pivoted at 14. One arm 18 of lever 6 carries contacts which are arranged to make contact with stationary contacts 7 or 8. A jockey roller as a neutral re laybut may be replaced by a 9, mounted adjacent the end of contact'arm 18,

serves to hold the latter in contact with which ever contact, 7 or 8, it is placed upon. Lever '2, through the medium of pinl2,' isfar'ranged to be rocked into either of the two'positions of armature 1 of relay 10. V

The bifurcated ends 19 and 20 of lever 2 are so arranged" with respect to arms 16 and 1'7 of lever 6 that in either its right or left hand polsition only one arm of lever 2 will contact with the corresponding arm of lever 6,as lever 2 is moved upward by lever 3. Thus, if armature 1 is in its left-handor attracted position, as shown, arm "20 of lever 2 will be opposite arm 1'7 of lever 6.

With the partsin this position, lever '6 will be rotated counter-clockwise by lever 2,as the latter is raised as cam erotates. Contact will thus be closed. When armature 1 is moved to its right-hand, position, under the influence of spring 6, lever 2 will move to the right and arm 19 Under this condition, when lever 2 wise, thereby opening contact 7 and closing contact 8.

The operation is as follows:

The mechanism is shown in the stop or rest position. The arrival of the start impulse from station X will operate relay 10 and armature 1 will move to the right, thereby bringingarm 19 of lever 2 opposite arm 16. At the same, time the clutch mechanism will be released, allowing shaft 5 to rotate. A tooth on cam 4 immediately lifts lever 3, causing lever 2 to rotate lever'6 about its pivot to open contact '7 and close contact 8, and the retransmitted or regenerated impulse is sent to station Y. Lever 3 immediately returns to its rest position, leaving lever 2 free ,to,be positioned by armature 1' in accordance with the first impulse of the code signal. When lever 2 has been positioned by armature 1, lever 3 is again raised by the next tooth on cam 4 and lever 6 either remains in contact with contact 6 or is moved to make contact with contact '7, depending upon whether the first impulse of the code signal is spacing or marking, respectively. The remaining impulses of the code signal act in a similar manner to position lever 6 in contact with contact 7 or 8 in accordance with the marking and spacing conditions corresponding to each impulse. Since cam 4 rotates under local control in synchronism with the incoming signals, lever 6 will be moved from contact '7 to contact 8, or vice versa, in definite time relation corresponding to the individual impulses of the code signals, and in this way the latter will be repeated into line 2 completely regenerated.

Referring now to Fig. 2, a bifurcated lever 22, pivoted to a lever 23 and 26, is oscillated in definite time relation by means of a toothed cam 24 carried by a shaft 56 driven at a constant speed and maintained in synchronism with the incoming signals, as will be explained later. Lever 22 is also under control of the armature 21 of a relay 40, whose winding 41 is connected with the line over which the signals are received. Lever 22, under the dual control of the toothed cam 24 and relay 40, serves to position a three-arm lever so as to cause arm 38 thereof to make contact with either contact 27 or 28 in accordance with the polarity of the signals received. The operation of this portion of the mechanism is the same as that already described in connection with Fig. 1.

Stops 45 and 46 on either side of the armature 21 of relay 4O serve as contacts to complete a circuit for magnet 50. The circuit may be traced from the battery 44, through the current limiting resistance 49, contact 45, armature 21 of relay 40, condenser 47, magnet 56 to ground. With the armature in the right-hand position, as shown, the circuit may be traced from ground through contact 46, armature 21, condenser 47, magnet to ground. The arrangement of this circuit is such that, each time the armature 21 makes contact with either contact 45 or 46, an impulse will be transmitted through magnet 50 to attract its armature 54 momentarily. Thus, when armature 21 makes contact with contact 45, condenser 47 will be charged and armature 54 of magnet 50 momentarily attracted. When armature 21 next makes contact with contact 46, condenser 47 will discharge through magnet 50, again momentarily attracting the armature 54.

The toothed cam 61, exactly like the toothed cam 24 on shaft 56', serves to oscillate armature 54 at right angles to the core of magnet 50 through the medium of a lever 55 pivoted at 62, the armature 54 being pivoted to arm 55 at 43. If armature 54 is in the retracted position, as shown, when it is raised by a tooth of cam 61, nothing happens. If, however, armature 54 is attracted by the magnet 50 at the time it is raised, it will contact with an arm 66 of a bell crank pivoted at 6'7, rotating the same in a clockwise direction. The other arm or" the bell crank 65 carries a pawl 68 pivoted at 69 adapted to engage a ratchet wheel 70 mounted concentric with the shaft 56. Rotation of the bell crank 65 in the clockwise direction will cause the pawl 68 to pass over and engage a new tooth on the ratchet wheel 76, so that when the pawl '71 of lever 55 passes over a tooth of the cam 61 and returns to its normal position, the ratchet wheel '70 will be turned a oscillation of lever 55 to which armature 54 is distance of one tooth in a clockwise direction under the influence of spring 57. The wheel '10 is retained in its new position by a jockey roller or holding pawl, not shown.

The apparatus is assumed to be driven by a constant speed motor such, for example, as a phonic wheel motor (not shown) whose shaft 60 (Fig. 3) carries a gear 59. Arranged to engage gear 59 is a second gear 51 carried by shaft 58, which also carries a third gear 52. Gear 52 is adapted to engage gear .53 carried by shaft 56. The gear ratios, 59 and 51, and 52 and 53, are such that shafts 6i] and 56 are driven at slightly different speeds. In the arrangement shown, shaft 56 is assumed to be rotating at a slightly higher speed than shaft 60. Shaft 58, to which gears 51 and 52 are rigidly attached, is journaled in bearings (not shown) carried by the ratchet wheel 76. It will thus be seen that, if ratchet wheel '75 rotated in a clockwise direction about shaft 56 as a center, shaft 56 will be advanced with respect to shaft 60.

In multiplex systems, in which mechanical correction is employed, it is common practice to rotate the receiving distributor either slightly faster or slightly slower than the transmitting distributor. It is further usual to generate the impulses for correcting the phase position of the receiving distributor from the signals through a system of relays and electrical circuits. In the repeater shown in Fig. 2, the receiving distributor is arranged to normally rotate slightly slower than synchronous s eed. Under this condition shaft 56 will gradually fall behind its proper synchronous position. When it has fallen sufiiciently far behind the synchronous position to allow 59 to attract armature 54 in time to cause it to engage the arm 66 of bell crank 65, the ratchet wheel '20 will he stepped ahead, advancing shaft 56 to its proper synchronous position. The correction is under the dual control of the incoming signals, since magnet 50 is energized each time relay armature 21 changes position and the receiving distributor which controls the pivoted. It will thus be seen that, although the shaft 56 tends to fall behind the true synchronous position, its phase position will be corrected as soon as it has fallen far enough behind for armature 54 to engage lever 66, and it will thereby be maintained in synchronism with the incoming signals.

In order for the signals to be properly regenerated, it is necessary for the cam 24 to be positioned in definite time relation with respect to the incoming signals. Although no means is shown for adjusting the relative phase relation of the cams 61 and 24, a differential gearing can be employed and when so used the cams 24 and 61 will be mounted on separate shafts coupled by this diiferential gearing. Such an arrangement is shown in United States Patent No. 1,543,119 of June 23, 1925.

What is claimed is:

1. In a regenerative repeater, the combination of a relay for receiving signals, a rotatable cam, a movable arm, a plurality of contacts, means controlled by the relay for positioning said arm in relation to said contacts, means controlled by the cam for operating said arm to cause the operation of the contacts with which it is positioned, means for creating a momentary impulse at each reversal of the received signals, a lever movable transversely under control of the momentary impulse, local mechanism controlling longitudinal movement of said lever, and means operated by said lever under such dual control to maintain said cam in synchronism with the received signals.

2. In a regenerative repeater, the combination of a relay for receiving signals, a set of contacts, a rotatable cam, means controlled by said cam for operating said set of contacts for retransmitting signals corresponding to the received signals, means controlled by said relay for creating a momentary impulse at each reversal of the received signals, a lever movable both laterally and longitudinally, one movement thereof being under control of the momentary impulse and the other under control of said local mechanical mechanism, and a correcting device operated by said lever under such dual control for maintaining said cam in synchronism with the received signals.

3. In a regenerative repeater, the combination of a relay for receiving signals, means controlled by said relay for creating a momentary impulse at each reversal of the received signals, a set of contacts, a rotatable cam, means controlled by said cam for operating said set of contacts for retransrnitting signals corresponding to the received signals, a locally operated second cam, a lever movable both laterally and longitudinally, one movement thereof being under control of the momentaiy impulse and the other under control of said second cam, and a correcting device operated by said lever under such dual control for maintaining said cams in synchronism with the received signals.

4. In a regenerative repeater, the combination of a relay for receiving signals, a set of contacts, a rotatable cam, means controlled by said cam for operating said contacts for retransmitting signals corresponding to the received signals, a shaft on which said cam is mounted, a second cam mounted on said shaft, a lever movable both laterally and longitudinally, one movement thereof being under control of the momentary impulse and the other under control of said second-mentioned cam, a ratchet wheel fixed to said shaft, a lever pivoted intermediate its ends and having at one end thereof a pawl for engaging the teeth of said ratchet and having its other end positioned to be engaged by said first-mentioned lever when moved both laterally and longitudinally under such dual control thereby to tilt said pivoted lever to cause the pawl to step back and engage a succeeding tooth of the ratchet, and means for causing the pivoted lever to return to normal position and move the ratchet wheel.

5. In a regenerative repeater, the combination of a relay for receiving signals, a set of contacts, a rotatable cam, means controlled by said cam for operating said contacts for retransmitting signals corresponding to the received signals, a shaft on which said cam is mounted, a second cam mounted on said shaft, a lever movable both laterally and longitudinally, one movement thereof being under control of the momentary impulse and the other under control of said secondmentioned cam, a ratchet wheel fixed to said shaft, a lever pivoted intermediate its ends and having one end thereof positioned to be engaged by'said laterally and longitudinally movable lever whilst under said dual control, and a pawl carried by the other end of said pivoted lever for engaging said ratchet wheel to effect a corrective movement thereof thereby to maintain said cams in synchronism with the received signals.

ERWIN P. BANCROFT.

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