US3274368A

US3274368A - Laminated distributor brush

Info

Publication number: US3274368A
Application number: US421877A
Authority: US
Inventors: Boo Jerome L De; Geoffrey B Lutz
Original assignee: Teletype Corp
Current assignee: AT&T Teletype Corp
Priority date: 1964-12-29
Filing date: 1964-12-29
Publication date: 1966-09-20
Anticipated expiration: 1983-09-20

Description

P 20, 1966 J. DE BOO ETAL 3,274,368

LAMINATED DISTRIBUTOR BRUSH Filed Dec. 29, 1964 FIG. 5

FIG. 6

INVENTORS JEROME L. DEBOO GEOFFREY B. LUTZ TTWU r 36 ATTORNE United States Patent Ofihce 3,274,368 Patented Sept. 20, 1966 3,274,368 LAMINATED DESTRIBUTOR BRUSH Jerome L. De B00, Earrington, and Geoflrey B. Lutz,

Evanston, lll., assignors to Teletype Corporation, Skokie, Ill., a corporation of Delaware Filed Dec. 29, 1964, Ser. No. 421,877 8 Claims. (Cl. 200-165) This invention relates to a distributor brush and a method of making it and more particularly to a distributor brush for use with a telegraph distributor and a method of making telegraph distributor brushes which assures that the resulting brushes will have certain highly desirable characteristics.

In the telegraph industry distributors are used to serialize telegraph signals onto telegraph lines. One type of distributor which has been used for this purpose is the commutator type wherein the segments of a segmented commutator ring are individually connected to the outputs of a telegraph transmitter and wherein a continuous commutator ring is connected to the telegraph line. Electrically connected distributor brushes simultaneously pass over the two rings thereby electrically connecting the ring segments to the continuous ring in step-bystep fashion and thus serially impressing the output of the transmitter onto the telegraph line. In order that the signals so serialized may be of optimum quality it is necessary that the distributor brush which travels over the segmented ring come into and go out of contact with the segments quickly and positively and that it does not make contact with two of the segments at once.

Accordingly, an object of this invention is to improve telegraphic communications by improving the distribution of telegraph signals.

Another object of this invention is to provide an improved telegraph distributor.

A further object of this invention is to provide a distributor brush which quickly and positively comes into and goes out of contact with the segments of a segmented commutator ring.

Another object of this invention is to provide a method of making distributor brushes which assures that they will quickly and positively come into contact with the segments of a segmented commutator ring.

According to the preferred embodiment of this invention a distributor brush is provided which is comprised of two superposed, flat layers of generally L-shaped Wires. The layers are mounted in a block of insulating material which is molded around the wires near the ends of their long sides. When in use the free ends of the wires are urged into engagement with the commutator ring of a telegraph distributor with sufficient force to cause the wires of one of the layers to merge substantially alternately with the wires of the other layer thereby presenting a single row of wires to the commutator ring. This assures that all the wires of the brush will come into and go out of contact at the same time. One method of making this type of brush is to form a plurality of straight wires into two superposed layers, mold an insulating material around one end of the layers, clamp the free ends of the wires into a single row, bend the wires into an L-shape and trim the wires while still clamped so that the free ends of the wires in the row form a straight line. This assures that when it is used the brush will present a single row of wires to a commutator ring.

A more thorough understanding of the present invention may be had by referring to the following detailed description when taken in conjunction with the drawings wherein:

FIG. 1 is a front view of a telegraph distributor employing the brush of the present invention;

FIG. 2 is an enlarged side view of such a brush;

FIG. 3 is an enlarged top view ofsuch a brush taken from the line 33 in FIG. 2 in the direction of the arrows;

FIG. 4 is a sectional view taken substantially along the line 4-4 in FIG. 2 in the direction of the arrows;

FIG. 5 is a first step in a method of making the brush of the present invention;

FIG. 6 is a second step, and

FIG. 7 is a third step.

Referring now to the drawings wherein like reference numerals designate like parts throughout the several views, with particular reference being had to FIG. 1, there may be seen a distributor face 11 upon which are mounted a segmented commutator ring 12 and a continuous commutator ring 13. A shaft 14 extends through the distributor face 11 and is rotatably mounted with respect thereto. Secured on the shaft 14 by means of a collar (not shown) and a snap ring 15 is a rotor 16. Mounted in the rotor 16 are a segment ring brush 20 and a continuous ring brush 21. These brushes are electrically connected by means of a bus 22.

As is usual in automatic telegraph apparatus the segmented ring 12 is divided into a plurality of segments including a start segment 25, a plurality of character segments 26, and a stop segment 27. A plurality of connectors, each of which are individually electrically connected to one of the segments, are provided, this plurality of connectors including a start segment connector 28, a plurality of character segment connectors 29, and a stop segment connector 30. The continuous ring 13 is electrically connected by means of a Web 31 to the start segment 25 and, therefore, to the start connector 28.

In use, the start connector 28 is attached to a telegraph line over which characters are to be sent in serial fashion. The character connectors 29 are individually connected to the outputs of a telegraph transmitter. This transmitter may be of any of the well known types, including punched paper tape readers and keyboard transmitters. The output of these transmitters is typically parallel in nature, that is, all of the bits of the signal are sent over a plurality of wires to the distributor at the same time. The stop segment connector 30 is normally connectedto a current source.

The usual practice in the telegraph industry is to transmit over telegraph lines signals in the form of a Baudot or start-stop code. In this code a current is applied to the telegraph line when signals are not being sent. This condition is known as a marking condition. When a si nal is sent the first bit applied to the telegraph line is known as a start bit and this is a spacing or no-current bit. After the start bit, a plurality of character bits may be transmitted which convey to a receiving apparatus the desired character. Finally, a stop bit which is a marking or current bit is sent. This informs the receiving station that the character has been completed.

In the present device as the shaft 14 is rotated by a motor (not shown) the rotor 16 rotates with it, thus driving the segment ring brush 20 and the continuous ring brush 21 simultaneously around the segmented ring 12 and the continuous ring 13. This causes the segment ring brush 20 to come into electrical connection with the start segment 25, the character segments 26, and the stop segment 27 of the segment ring 12 in step-by-step fashion. Since the segment ring brush 20 is electrically connected to the continuous brush 21 by the bus 22 and continuous ring 13 is connected to the telegraph line, this operation puts the various segments of the segmented ring 12 into an electrical connection with the telegraph line in step-bystep fashion. The first segment connected by the segment ring brush 20 in its progress around the segmented ring 12 is the start segment 25. Since this segment is connected by the web 31 to the continuous ring 13 and by the connector 28 to the telegraph line there will be no current available for application to the telegraph line at this time. Thus, a spacing bit will be applied to the line in the usual telegraph fashion. The speed of rotation of the shaft 14, together with the amount of the ring 12 devoted to the segment 25, determine the length of the start pulse. After the brush 20 has left the start segment 25 it will come into contact in step-by-step fashion with each of the character segments 26. An equal portion of the ring 12 is devoted to each of these character segments so that the amount of time each of them is connected to the telegraph line is the same. Since each of the segments 26 is individually connected by a connector 29 to an output of a telegraph transmitter, current may or may not be available for application to the telegraph line at each of the segments 26 depending upon the output of the telegraph transmitter. Each possible character to be transmitted with apply current or no current to a different permutation combination of the segments 26 and thus as the brush 20 traverses the character segments 26 various combinations of marking and spacing bits, representing various characters, will be applied to the telegraph line. After having traversed all of the segments 26 and brush 20 will engage the stop segment 27. Since a current is always applied to the stop segment 27 by means of the connector 30, the brush 20 will apply current to the continuous ring 13 and, therefore, to the telegraph line when the brush is in engagement with the stop segment 27. Typically, the shaft 14 is connected to its driving motor (not shown) by a clutch (not shown). If a character is to be sent immediately after the sending of a previous character is terminated, this .clutch remains in engagement and shaft 14 continues rotation. However, if no character is to be sent after the sending of a previous character is terminated, the clutch is disengaged and the brush 20 comes to rest on the stop segment 27. Thus, when no characters are being sent by the distributor a marking or current condition remains on the telegraph line.

From the foregoing description it may be understood that the quality of the signal which is serialized onto the telegraph line by the distributor is dependent upon the quality of the electrical contact made between the segments of the segmented ring 12 and the segment brush 20. In recent years the speed at which characters are serialized onto telegraph lines has increased from 6.5 characters per second to characters per second. At the same time the characters have come to be comprised of eight bits rather than five bits. The combination of these factors have resulted in the time duration of the bits being materially reduced. Consequently, it is imperative to assure that the marking or spacing condition of each of the bits is fully recognized throughout the time duration of the bit.

In accomplishing this end it is desirable that the brush which engages the segments of the segmented ring 12 not be in contact with two of the segments at once. This assures that if one of the segments is in marking condition and the other is in a spacing condition then it will not be possible for the brush to apply the marking condition of the first segment to the line while it is in partial engagement with the second segment. It is also desirable to have all of the wires which comprise the segment brush engage and disengage an individual segment at the same time. This assures that the entire current carrying capacity of the brush is available throughout the period in which the brush is engaged with the segment. Finally, it is desirable that the brush not bounce when it initially comes into contact with a segment, which may lie in a plane which is either raised from or lowered below the plane of the distributor face 11. All of these characteristics aid in assuring that the segment brush 20 will be in complete electrical contact and Will be fully capable of conducting a current from the segment to the telegraph line during the entire time that the brush is positioned above the segment.

As may be best seen in FIGS. 2, 3, and 4 the brushes 2t) and 21 are comprised of two layers of generally L- shaped wires. These layers are held in superposed relation one to the other by the rotor 16 and, as is seen in the dotted line drawing in FIG. 2, when the brush is not used the layers maintain their separate character throughout the length of the brush. As may be seen in the solid line portion of FIG. 2 and in FIG. 3 when the brush is held in contact with the distributor face 11 by the snap ring 15, the wires of one of the layers merge substantially alternately with the wires of the other layer so that the brushes present a single straight row of wires to the distributor face 11. In so merging the free ends of the

brushes

20 and 21 fan out so that the single straight row of wires which is in contact with the distributor face 11 has a width approximately double the width of one of the layers when the brush is in an unloaded condition. The single straight row of wires of the brush causes it to have a minimum width in the longitudinal direction. This allows an absolute minimum separation between the segments of the segmented ring 12 and also allows all of the wires of the brushes to come into and to go out of electrical contact with the segments at virtually the same time. Since the layers of Wires are merged alternately one with the other the brush has a substantial amount of interwire friction which prevents the wires from bouncing any substantial amount when they are brought into contact with a segment.

The brushes are formed so that when they are in use their free ends engage the distributor face 11 on a line which lies in a plane which extends through the axis of the shaft 14 and which is perpendicular to the plane of the distributor face 11. In order to assure that the brushes will have the proper dimensions and that they will fan out into a single straight row when in use, they must be manufactured in a very precise and accurate manner. To this end the method of making the brushes which is schematically illustrated in FIGS. 5, 6, and 7 may be used.

As shown in FIG. 5 a plurality of wires have been arranged in two superposed layers and the ends of the wires have been molded into rotor 16. After the molding operation is completed, the layers of wires are brought into contact with an upper surface 35 of a block 36 and a gripping ram 37 is lowered thus gripping the wires between the ram 37 and the surface 35. This gripping action causes the free ends of the layers of Wire to merge into a single row of wires. After the wires are gripped by the ram 37 a bending ram 38 is lowered. This bending ram 38 cooperates with the block 36 to form the wires into a generally L-shaped configuration. The bending ram 38 is so constructed that it cooperates with the blocking ram 37 to rigidly grip the free ends of the wires after the bending operation is complete. At this time a knife 39 is used to trim the free ends of the wires to the proper length thus assuring that when the brush is in use the wires not only will have the proper dimensional characteristics, but that the wires will properly fan out to present a single straight row of wires to the distributor face 11. After the trimming operation is complete, the

rams

37 and 38 and the knife 39 are removed thus allowing the brush to resume the shape shown in the dotted line portion of FIG. 2.

Although particular embodiments of the invention are shown in drawings and described in the foregoing specification, it will be understood that the invention is not limited to these specific embodiments, but is capable of modification and re-arrangement, and substitution of parts and elements without departing from the scope of the invention.

What is claimed is:

1. The combination with a plurality of brush contacting surfaces, of a distributor brush comprising:

a first layer of generally L-shaped, resilient wires positioned adjacent each other in a substantially straight row;

a second layer of generally L-shaped, resilient wires positioned adjacent each other in a substantially straight row, and

means holding the layers in a position where they bear upon the contacting surfaces with sufficient force to flex all of the wires of both layers and to merge the two layers into a single row of wires.

2. The combination with a brush contacting surface, of

a brush assemblage comprising:

a first row of resilient wires of a first positioned in alignment one with another;

a second row of resilient wires of a second length positioned in alignment one with another;

means for holding the first row and the second row in superposed relation one to the other, and

means holding the two rows against the contacting surface with sufficient force to cause the two rows to merge into a single row.

3. The combination of a distributor and a distributor brush comprising:

a first plurality of generally L-shaped wires positioned adjacent each other in a substantially straight row extending normal to the axis of the wires;

a second plurality of generally L-shaped wires positioned adjacent each other in a substatnially straight row extending normal to the axis of the wires;

means holding the second plurality of wires in grooves for-med between the first plurality of wires; and

means urging all of the wires of the first plurality and all of the wires of the second plurality simultaneously into engagement with the distributor to force the wires of the second plurality to merge with the Wires of the first plurality thereby causing the distributor brush to present a single, straight row of wires to the distributor.

4. The combination of a telegraph distributor and a brush for it including:

a flat, commutator type distributor face;

a rotor for circular movement with respect to the distributor face;

a distributor brush comprised of two superposed layers of generally L-shaped flexible wires, and

means attached to the rotor holding the brush against the distributor face with sufficient force to cause the wires of the brush to flex and form at their free ends a single straight row of wires.

5. The combination of a telegraph distributor and a distributor brush including:

a distributor face having a segmented commutator ring,

a rotor for rotational movement with respect to the distributor face;

a distributor brush comprised of two superposed layers of flexible, generally L-shaped wires for electrical contact with the segmented ring of the distributor face, and

means attached to the rotor urging the distributor brush into engagement with the segmented ring of the distributor tace with sufiicient force to cause the wires of one layer of the brush to merge substantially alternately with the wires of the other layer of the brush thereby causing the distributor brush to present a single, straight row of wires to the segmented ring of the distributor face.

6. The combination of a telegraph distributor and a distributor brush including:

a distributor face comprised of an outer segmented commutator ring and an inner, continuous commutator ring;

a rotor for rotational movement with respect to the distributor face;

a first distributor brush for electrical contact with the inner ring of the distributor face;

a second distributor brush comprised of two superposed layers of flexible, generally L-shaped wires for electrical contact with the outer ring of the distributor face;

means electrically connecting the first and the second distributor brushes; and

means attached to the rotor urging the second distributor brush into engagement with the outer ring of the distributor face with sufiicient force to cause the wires of one layer of the brush to merge substantially alternately with the wires of the other layer of the brush thereby causing the second distributor brush to present a single, straight row of wires to the outer segmented ring of the distributor face.

7. A telegraph distributor for receiving the output of a telegraph transmitter and -for serializing the output onto a telegraph line comprising:

a plurality of electrically conducting segments including a plurality of bit segments each adapted to be individually electrically connected to one of the outputs of the transmitter;

an electrically conducting commutator ring adapted to be connected to the telegraph line;

an electrically conducting commutator brush in substantially constant engagement with the commutator ring;

an electrically conducting segment brush which presents a single, straight row of wires to the conducting segrnents;

an electrical connection between the two brushes, and

a rotor bringing the segment brush into electrical connection with the segments in succession thus serially connecting the segments to the commutator and therefore to the telegraph line, the single row, straight line character of the segment brush assuring that the entire segment brush will come into contact with the individual segments at the same time.

-8. A telegraph distributor for receiving the output of a telegraph transmitter and for serializing the output onto a telegraph line comprising:

a plurality of electrically conducting segments circularly positioned around a fixed point and consisting of a plurality of bit segments each adapted to be individually electrically connected to one of the outputs of the transmitter, a start segment and a stop segment;

an electrically conducting commutator ring adapted to be connected to the telegraph line and circularly disposed about the fixed point;

an electrically conducting segment brush which presents a single, straight row of wires to the conducting segments;

an electrical connection connecting the two brushes;

a rotor which rotates about the fixed point and which '2' supports the two brushes in engagement, respectively, with the segments and commutator ring thereby brin ing the segment brush into electrical connection with the segments in sequence thus serially connecting the segments to the commutator and therefore to the telegraph line, the single row, straight line character of the segment brush assuring that the entire segment brush will come into contact with the individual segments at the same time, and means rotating the rotor.

References Cited by the Examiner UNITED STATES PATENTS ROBERT K. SOHAEFER, Primary Examiner.

10 H. O. JONES, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,274,368 September 20, 1966 Jerome L. De Boo et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 35, for "with" read will line 41, f0 "and" read the column 5, line 30, after "first" insert length line 45, for, "substantnially" read substantially column 6, line 22, after "means" insert for (SEAL) EDWARD J. BRENNER Commissioner of Patents ERNEST W. SW'IDER Attesting Officer

Claims

1. THE COMBINATION WITH A PLURALTIY OF BRUSH CONTACTING SURFACES, OF A DISTRIBUTOR BRUSH COMPRISING: A FIRST LAYER OF GENERALLY L-SHAPED, RESILIENT WIRES POSITIONED ADJACENT EACH OTHER IN A SUBSTANTIALLY STRAIGHT ROW; A SECOND LAYER OF GENERALLY L-SHAPED, RESILIENT WIRES POSITIONED ADJACENT EACH OTHER IN A SUBSTANTIALLY STRAIGHT ROW, AND MEANS HOLDING THE LAYERS IN A POSITION WHERE THEY BEAR UPON THE CONTACTING SURFACES WITH SUFFICIENT FORCE TO FLEX ALL OF THE WIRES OF BOTH LAYERS AND TO MERGE THE TWO LAYERS INTO A SINGLE ROW OF WIRES.