US2521750A - Selector mechanism for printing telegraph receivers - Google Patents

Description

Sept. 12, 1950 R. D. SALMON 2,521,750

SELECTOR MECHANISM FOR PRINTING TELEGRAPH RECEIVERS Filed Dec. 13, 1946 2 Sheets-Sheet l INVENTOR fPfG/NHZO 0. 5/71 MU/V ATTO R N EY Sept. 12, 1950 R. D. SALMON 2,521,750

SELECTOR MECHANISM FOR PRINTING TELEGRAPH RECEIVERS Filed Dec. 13, 1946 2 Sheets-Sheet 2 ATTORNEY Patented Sept. 12, 1950.

SELECTOR MECHANISM FOR PRINTING TELEGRAPH m omvens 1 Reginald Dennis Salmon, 'Croydon, England, assignor to Creed and Company Limited, 'Croydon, England, a British company Application December 13, 1946, Serial No. 715,903 In Great Britain October 23, 1945 Section 1, Public Law 690, August 8, 194-6 Patent expires October 23, 1965 6 Claims. 1

This invention relates to printing telegraph receivers. More particularly the invention relates to that kind of printing telegraph receiver in which storage members are set in accordance with the code elements of the signal combination and these members are afterwards caused to act upon the translator mechanism. The present invention relates to the selecting and storage mechanism and is independent of the nature of the translator mechanism, that is, the mechanism for translating the setting of the storage members into the positioning of a type wheel, selection of a type bar or like means for ensuring that the correct character or representation thereof is printed or perforated.

It is the object of the present invention to provide a signal selector and storage mechanism of simple construction that is cheap and easy to manufacture and maintain and having a higher degree of tolerance than known mechanisms for distorted signals without increasing the power consumption. l

a The degree of tolerance for distorted signals dependsupon the time required for the current in the magnet winding to rise to its operating value and the time required for the armature to move to its operative position. In order to reduce the last mentioned time it is one object of the present invention to reduce to a minimum the moment of inertia of the electromagnet armature system.

In one representative known arrangement described in British Patent Specification #228,842, storage members are set by a striker pin traversed past them and struck towards successive storage members in the middle of successive signal elements, the striker pin. being efiective to set the respective members in accordance with the position of-the magnet armature at the appropriate time. It was accordingly necessary for a member carried by the armature system to be sufiiciently extended to cover five successive positions of the striker pin (for a -unit code).

According to one feature of the present invention I provide a signal selector and storage mechanism for a printing telegraph receiver comprising storage members for the successive elements of abode combination, means for traversing said storage members past the position of a member carried by the armature of the receiving magnet, and means for setting successive storage members in accordance with the successive positions of the armature.

' By means of this feature the armature memher-that acts upon the storagemembers can be .made of extent only large enough to co-operate is then struck in the last mentioned direction to act upon the successive storage members.

On the other hand the said armature member may be carried in guides in the armature system and be struck endways to act upon the successive storage members.

Another factor affecting the tolerance of the signal selecting mechanism to distorted signals is the moment of inertia of the selector cam. When the start element of a signal is received this cam must be accelerated to the required angular velocity and the rate of acceleration will vary from time to time due to changes in the condition of its driving clutch. The moment of operation of each selecting action with respect to the start element of the signal will vary. In order to reduce the magnitude of this variation the time required to accelerate the cam must be made small. This involves either a powerful clutch or a low moment of inertia of the cam.

The selector cam assembly therefore, is preferably driven by a clutch independently of all other cams in the machine.

By this means the moment of inertia of the selector cam assembly is made very small and can be made of very light and rigid construction. Preferably also the clutch driving the selector cam assembly is a friction clutch since this can be made'to have less Variation in pick-up time than a-ratchet clutch.

Two embodiments of the invention are hereinafter described with reference to the accompanying drawings, in'which:

Figs. 1 to 6 show different parts of one form of signal selector and storage mechanism according to the invention, th inter relation between the parts being clear from the fact that at least one part is common to one or more of the figures.

Figs. '7 and 8 show a second form of signal selector and storage mechanism according to the invention.

Referrin to the drawings and first to Figs. 1

to 5, the signal receiving magnet l is shown in Fig. 1 somewhat diagrammatically.

Whatever form of construction be used for this electrcmagnet I, the proportions and details of design are preferably such that it develops maximum efiiciency for that particular degree of movement of the armature "2 required to perform the operations described below.

The armature 2 is fixed to a pivot rod 3 mounted in fixed bearings (not shown). Fixed to the pivot rod 3 is a light armature lever 4. of the lever i is upturned at 5 and engages a latch 8 which is pivoted at i on one arm of a detent release lever 3 in the form of a bell crank, in turn pivoted at .l on the framework of the machine. The detent release lever B is urged in a counterclockwise direction by a spring i3, whilst the latch 6 is urged in a clockwise direction by a spring I I.

The selector cam assembly consists of two discs only, one being a detent plate 12, Figs. 1 and 2, and the other the selector cam proper [3, Fig. 3. These two discs are fixedly mounted on a short shaft I4, driven from a constantly rotating shaft (not shown) through a friction clutch in well known manner. This cam assembly is very light and requires only a small amount of power to accelerate it rapidly.

The selector cam assembly is normally held against rotation by means of the engagement of a projection 55 thereon with the bent over end of one arm l6, Fig. 1, of a detent lever. This detent lever has three arms Hi, I! and H3, and is pivoted at H! on a frame 28 that can be moved by hand in an arc coaxial with the axis of rotation of the selector cam assembly. Rotation of the frame is for the purpose of orientation adjustment, a scale 2i being provided to indicate the degree of adjustment.

The middle arm ll of the detent lever embraces a pin 22 on the detent release lever-8. The third arm It is for the purpose of resetting the detent lever in a manner presently to be explained.

When the start element of a signal is received the armature 2 moves to the right in Fig. l zand rotates the armature lever L2 in aclockwise direction, thus allowing the latch '6 to follow it and allowing the detent release lever B to be moved by its spring it in a counterclockwise direction.

The arm l6 of the detent lever is-also rotated in 1 a counterclockwise direction thus removing its end from the projection l5 and allowing the se lector cam assembly to rotate in the direction of the arrow. The latch 6 is drawn by its spring El until it contacts with a fixed stop'23, which causes the latch ii to be disengaged from the upturned end of the armature lever 4. I

The detent plate I2 is formed with two bent over lugs 24 and 25, lug 24 being bent downwards from the plane of the paper in Fig. 1 and lug 25 5.."

being bent upwards. Lu 25, during the rotation 01" the detent plate l2 engages the end of arm 18 0f the detent lever a little before the plate has returned to normal position. The detent lever is rotated clockwise about its pivot E9 the end of arm 16 replaced in the path of'projection I5 on the detent plate and the selector cam. assembly is thus brought to rest after one revolution. This will happen even if the armature 2 remains in spacing position since the clockwise rotation of the detent lever it will cause rotation of lever 8 in a clockwise direction and upward movement of latch 8. Should the armature lever 4 be in'its left hand position or marking position, latch 6 will re-engage the upturned end 5 of armature lever 4, but if, due to non-receipt of the stop element or other mischance, the armature l remains in spacing position and armature lever 4 is in its right hand position, a, tooth 26 on the latch ii will be moved beyond the fixed stop 23 and the spring One end I! will draw latch 6 to the right. Engagement of tooth 25 with the fixed stop 23 will then prevent movement of latch 6 downwards in Fig. l and the detent lever B will be held with arm IS in engagement with projection IS on the detent plate i2 and the selector cam assembly cannot be again released until the armature 2 has first been moved to marking position, when the end 5 of armature lever will re-engage latch 6, and then is moved to spacing position.

Lug 24 on detent plate l2 engages, shortly after the latter has commenced its rotation, an arm of a. lever 21, Fig. 2, which is held by a spring 28 in engagement with a pawl 29 and thus holds the pawl 29 out of engagement with a ratchet 30. The ratchet 30 is mounted on a motor driven shaft 3,! and the pawl 29 is carried on a cam sleeve 32 which carries the translator cam and other cams for the operation of the machine, other than the selector cam assembly. When lug 24 on plate l2 engages the lever 21, the latter is moved out of engagement with the pawl 29 and allows the latter to be drawn by spring (not shown) into engagement with the ratchet 30.

U The pawl 23 and ratchet 30 constitute a well known form of ratchet clutch by means of which when engaged the cam sleeve 22 is driven by the motor driven shaft 21.

The left hand arm of the armature lever 4 carries at its end a plate 33, Fig. 3, having therein a slot in which slides one end of a striking rod 34, the other end of which is pivoted to the end of a striking lever 35. This latter lever is pivoted at 36 and is drawn to the right in Fig. 3 by a spring 31, with a roller 38 on the lever engaging the selector cam l3. The selector cam I3 is formed with five humps which cause leftward movement of lever 35 and so move striker rod 34 to the left. It will be observed that the left-hand end of armature 4 is provided with a bent-over lip 33 which can assume either one of two positions, namely the full-line position or the dotted line position shown in Fig. 3, depending upon whether the magnet I is energized or de-energized. Mounted adjacent the lip 33 is a pivoted lever 35a which is held in the position shown in Fig. 3, against the tension of spring 36a and under control of the lever 35 when the roller 38 is resting in a valley of the cam I3 as a result of the tension of spring 37. In this relation, the lever 35a has its lower end held in the position shown in Fig. 3 by engagement with a suitable groove or notch in rod 34. When the roller 88 engages a raised portion of cam I3, the lever 35a is moved to the left and if the armature 4 is in full line position as shown in Fig. 3, the right angled lip 31a of lever 35a latches over the upper surface of lip 33, thus mechanically holding the armature in its full line position. If, however, the magnet is energized, the armature 4 moves the lip 33 to the dotted position shown in Fig. 3, so that the movement of lever 35 causes the lip 31a to latch beneath the lip 33, thus holding the armature 4 in its operated position.

As previously described the translator cam sleeve 32, Fig. 2, has been released for rotation. This cam sleeve carries cams to control the translating mechanism and to initiate other functions of the machine. One of the cams thereon, viz. cam 39, Fig. 3, causes the endways traverse of a frame 40, Figs. 3 to 6, along a spindle 4!. The frame 40 carries a pin 42 the axis of which is parallel to spindle 4|. Mounted on pin 42 are five. signal storage members 43 separated from each other by spacing washers. The storage members 43 and washers are pressed together by a spring 44, Fig. 5, mounted on the pin 42. The storage members are free for a limited amount of rotation on pin 42 being held by friction in the position into which they are rotated whilst the washers are prevented from rotating with respect to the pin.

The shape of the storage members 43 is seen in Fig. 3 and in Fig. 6. Each of them is formed with short arms extending vertically upwards and downwards respectively and a horizontal arm.

Endways motion of the frame 46 causes the storage members 43 to be traversed past the end of the striker rod 34, Fig. 3. When the armature lever 4 is in its lowest position striker rod 34, when moved to the left in Fig. 3, strikes the upper vertical arm of a storage member 43. When the armature lever 4 is in its upper position, striker rod 34 misses the storage member. The endways motion of the frame 40 is timed by cam 39 so that the five storage members 43 are brought into line with the striker rod 34 seriatim so that the successive storage members 43 are struck by successive striking actions of the rod 34.

As the frame 40 moves endwise into the position when the fifth storage member 43 can be struck by rod 34, a hole in the side of the frame 40 engages a pin 45 fixed to a two-armed lever 46 fixed on the spindle 4|, Fig. 4. Lever 46 carries rollers 41 engaging cams 48 on the translator cam sleeve. After the fifth striking action is completed one of the cams 4B acting on lever 46 rocks the spindle 4| to move the storage members 43 away from the striker rod 34 and towards five pairs of bell crank levers 49. One pair of these levers is shown in Fig. 4.

The bell crank levers 49 are pivoted on pins 50 and 5| respectively. The vertical arms of each pair extend towards one another and the horizontal arms extend in a direction away from the striker rod 34. The horizontal arms of each pair of bell crank levers 49 engage with a vertical rod 52 which is linked with a combination disc 53, Fig. 4.

When a storage member 43 is in the unset po sition represented by the full line in Fig. 4, it engages the downwardly extending arm 49a of its corresponding upper bell crank lever 49, and when in the set position represented by the dotted line in Fig. 4, the storage member 43 engages the vertical arm 49b of the lower bell crank lever. Actuation of the upper bell crank lever 49 will move the vertical rod 52 into an upper extreme position and actuation of the lower bell crank lever 49 will move this rod into a lower position. Movement of the rod 52 will result in rotation, in one direction or the other, of the corresponding combination disc 53.

Immediately the storage members 43 are moved clear of the bell crank levers 49 after the vertical rods 52 are set, the frame 40 is moved by cam 39, Fig. 3, endways to bring the first storage member 43 again into line with the striker rod 34. During its sideways and rotary motion the frame 46 is controlled by a guide plate 54 (Figs. 4 to 6) and as the frame 46 returns to its initial position and becomes disengaged from the driving pin 45, the frame is controlled in a fixed rotary position by this guide plate. One of the cams 48, acting on lever 46 rotates the spindle 4| with the driving pin 45 disengaged and a resetting lever 55, Fig. 6, fixed to spindle 4| engages the downward projection on each storage member 43 and ture 2 has fixed thereto a blade 56 having considerable rigidity in a plane at right angles to a plane containing the axis of the spindle 3 but having compliance in a direction parallel to the axis of that spindle.

The selector cam assembly consists, as in the first embodiment described of a detent plate and a selector disc l3. The arrangements for releasing this cam assembly for rotation and for the release by the detent plate of the translator cam assembly are similar to those in the first embodiment.

v The selector lever 35 is acted on by the selector cam l3 as previously described and strikes the blade 56 sideways towards a storage member 43. The storage members are of slightly different shape from those in the first embodiment and each has a vertical projection 43a. tocooperate with theblade 5t and two other projections 43b and 430. The storage'members 43 are mounted in a frame 4|; and are traversed past the end of blade 56 by a cam 33 onthe translator cam sleeve. When selector lever 35 strikes blade 56 sideways, the blade 56 either rotates a storage member 43 or misses it, according to the position of the armature 2.

When the frame 46 has moved into the position where the fifth storage member 43 can be struck and lever 35 has finished its stroke, a cam 31 rotates a bell crank lever 58 in a clockwise direction against a spring 59.

Pivoted on a common pivot 60 on bell crank lever 58 are five sword members 6| which are thus brought against the arms of their corresponding storage members 43 and rotated according to the positions in which said storage members were set. The sword members 6| are linked with combination discs '53 which are accordingly rotated through a small arc in one direction or the other.

The swords 6| after being set are moved clear of the storage members 43 and immediately afterwards the frame 46 is moved to bring the first storage member again into line with the end of the selecting blade 56.

What is claimed is:

1. Signal selector and storage mechanism for a printing telegraph receiving machine, comprising, an electro-magnet having an armature, a plurality of selectively shiftable storage elements, one for each signal element of a plural element code, a setting member controlled by said electromagnet for setting said storage elements, said storage elements being mounted in an array with respect to said member so that said member is capable of cooperative engagement with respect to only one of said elements at a time, a frame carrying said storage elements, cam control means for reciprocating said frame laterally with respect to said setting member, and other cam control means for moving said frame bodily as a unit in a direction transverse to said reciprocating movement for causing said setting member to be operative to set each of said storage elements in turn in accordance with the selective positions of said armature as determined by the successive code elements of a received signal.

2. Signal selector and storage mechanism according to claim 1, further comprising a plurality of code combination discs, one for each element of the code, a plurality of pairs of rockably mounted elements, each pair linked to a difieren't one of said discs and the elements of each pair adapted to move said discs in opposite directions, said storage elements mounted in selective positioning array with said pairs of rockable elements, each of said storage elements adapted to engage either of said rockable elements in response to movements of said setting member.

3. Signal selector and storage mechanism according to claim 1 in which said storage elements are mounted in a reciprocating frame, cam control means are provided for reciprocating said frame laterally with respect to said settingmember, means tomove said frame and said storage elements in one direction perpendicular to said reciprocation movement, and means to re-set said storage elements while said frame is being moved in the opposite direction perpendicular .to said reciprocation movement.

4. Signal selector and storage mechanism according to claim 1 in which each of said storage elements comprises, an operating arm arranged to assume either an upper or lower position as determined'by said electromagnet, a plurality of upper and lower sets ofbell crank levers i operative engagement with said storage element arms,

and a plurality of shiftable combination rods arranged to be moved selectively in either direction under control of an associated one of said bell crank levers.

5. Signal selector and storage mechanism according to claim 1 in which cam control means are provided for locking said armature in either of two positions while said storage elements are being set by said setting member.

6. Signal selector and storage mechanism according to claim 1 in which said armature carries a locking lip and a locking lever is pivotally mounted with respect to said lip to lock the armature in either of its two selective positions while said storage elements are being selectively set by said setting member.

REGINALD DENNIS SALMON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,108,529 Underhill Aug. 25, 1914 1,904,164 Morton et a1 Apr. 18, 1933 1,917,308 Krum July 11, 1933 1,932,932 Griffith Oct. 31, 1933 2,262,471 Shoenberg Nov. 11, 1941 2,273,083 Angel Feb. 17, 1942

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