US3371602A

US3371602A - Serial type printer with disc-type carrier

Info

Publication number: US3371602A
Application number: US543429A
Authority: US
Inventors: Joseph F Cattorini; Donald E Landis; Larry L Leiter
Original assignee: NCR Corp
Current assignee: NCR Voyix Corp; National Cash Register Co
Priority date: 1966-04-18
Filing date: 1966-04-18
Publication date: 1968-03-05
Anticipated expiration: 1985-03-05
Also published as: GB1133168A

Description

March 5, 1968 j (:ATTORIN] ET AL 3,371,602

SERIAL TYPE PRINTER WITH DISC-TYPE} CARRIER 6 Sheets-Sheet 1 Filed April 18, 1966 FIG.

INVENTORS JOSEPH F. CATTORINI DONALD E. LANDIS LARRY L. LEITER THEIR ATTORNEYS March 5, 1968 J. F. CATTORINI ET AL 3,371,602

SERIAL TYPE PRINTER WITH DISC-TYPE CARRIER Filed April 18, 1966 6 Sheets-Sheet 2 62 FIG. H 5a 250 CARRIER MEANS INDEXING FCODE LINES INPUT DEVICE P2?) 268 v l2 vrm ||6(88) INVENTORS wfixc'oz wsag" (+2?) 2552 "6(86) LARRY LJLEITER (-41) 7 BY M;

THEIR ATTORNEYS March .5, 1968 J. F. CATTORINI ET AL 3,371,602

SERIAL TYPE PRINTER WITH DISC-TYPE CARRIER Filed April 18, 1966 s Sheets-Sheet :3

" FIG. 3

26 mvemons 149 J JOSEPH F. CATTORINI DONALD E. LANDIS LARRY L. LEITER THEIR ATTORNEYS March 5, 1968 I J. F. CATTORINI ET AL 3,3

SERIAL TYPE PRINTER WITH DISC-TYPE CARRIER Filed April 18, 1966 6 Sheets-Sheet 4 FIG. 7

INVENTORS JOSEPH F. CATTORINI DONALD E. LANDIS LARRY L. LEITER THEIR ATTORNEYS March 5, 1968 j J .F. CATTORINI ET AL 3,371,602

I SERIAL TYPE PRINTER WITH DISC-TYPE CARRIER Filed April 18, 1966 e Sheets-Sheet 5 FIG. 8 ggin FIG. l2

SEG.

NO. CHAR.

INVENTORS JOSEPH .F. CATTORINI DONALD E. LANDIS LARRY L. LEITER BY W QXZQ Fw 7 THEIR ATTORNEYS March 5,

J. F. CATTORINI ET AL 3,371,602

SERIAL TYPE PRINTER WITH DISC-TYPE CARRIER Filed April 18, 1966 6 Sheets-Sheet 6 FIG. l3

CODE LINES 3 l2-3 ||-3 0-3 12-1 O-l CHARACTER 3 c L n A J A CODE LINES 3-8 l2-3-8 ll-3-8 0-3-8 7 12-? 0-? N CHARACTER 7 G P x I CODE LINES 9 l2-9 ll-9 0-9 8545, l2 u 0 CHARACTER 9 1 R (BLANK) 0 coos LINES 5 l25 "-5 0-5 8 l2-8 u-s 0-8 g CHARACTER 5 E N 8 H O Y I; U 0005 LINES 4 |2-4 11-4 0-4 2 12-2 u-z 0-2 a CHARACTER 4 0 M 2 B K 8 CODE LINES 4-8 I2-4-8 ||-4-8 0-4-8 8 I2-6 u-e 0-6 CHARACTER v 8% 6 F 0 w TYPEWHEEL CONTROL INVENTORS JOSEPH F. CATTORINI DONALD E. LANDIS LARRY L. LEITER THEIR ATTORNEYS United States Patent Ofiice 3,371,6fl2 Patented Mar. 5, 1968 3,371,602 SERIAL TYPE PRINTER WITH DISC-TYPE CARRIER 1 Joseph F. Cattorini, Xenia, Donald E. Landis, Bellbrook, and Larry L. Leiter, Centerville, Ohio, assignors to The National Cash Register Company, Dayton, Ohio, a corporation of Maryland Filed Apr. 18, 1966, Ser. No. 543,429 7 Claims. (Cl. 101-93) ABSTRACT OF THE DISCLOSURE A printing apparatus which utilizes a disc-type carrier having a plurality of type wheels rotatably mounted thereon and operatively connected to a sun gear which can simultaneously rotate all the type wheels. On-otf springtype clutch members are used to actuate cam members which cooperate with constant length belts to rotate the carrier and the sun gear so as to position a preselected type wheel and printing character thereon in printing relation with a platen in the apparatus. The clutch members are actuated in response to the Hollerith code.

This invention relates to a printing mechanism, and more particularly it relates to a serial-type, high-speed printer mechanism.

The printers which are normally associated with dataprocessing machines such as card punches are usually of the wire-matrix design. This type of printer employs a matrix of wires which is usually arranged in five columns of seven wires per column to form a five-by-seven matrix. Various mechanisms and/or circuits are used to select the specific Wires to be actuated to produce the desired character. Upon actuation, the selected wires are driven against an inked ribbon and a punched card to produce an impression of the desired character on the card.

One of the main reasons for using a matrix-type printer in connection with a card punch machine is that the matrix-type printer is adaptable to the limited space available in a serial-type card punch and printer machine. The printing on a punched card usually appears along a line on a longitudinal edge thereof, and holes may have to be punched into the card approximately .075 inch away from the line of printing at speeds of approximately thirty cycles per second.

The matrix-type printer appears to be adapted for such small space limitations; however, this printer does have undesirable features. The chief objection to a wire matrix printer is that it produces a poor quality of printing. Another objection is that the means for selecting and actuating the appropriate wires in the matrix to produce the desired character usually necessitates the use of expensive mechanism (mechanical and/ or electrical).

Accordingly, the primary object of this invention is to provide a compact, high-speed, serial-type printing mechanism which, though capable of many uses, is especially adaptable for use with a high-speed card punch machine.

Another object of this invention is to provide a typewheel printer capable of operating at speeds of thirty cycles per second or in excess.

A further object is to provide a typewheel printer of the above variety which is not required to return to a home position after each cycle of operation.

A still further object is to provide a printing mechanism having actuation means which is effective to position the printing head according to the character selected for printing in both on and off states of the actuation means.

Another object of this invention is to provide a printing mechanism whose printing head remains in the last printing position selected until a new character is selected,

thereby permitting the actuating means used for character selection to operate at a reduced speed compared to the printing head to which it is operatively connected.

Stated generally, the printing mechanism of this invention comprises a frame member on which a printing head is mounted. The printing head utilizes a disc-type carrier means having a hollow stem secured to one side thereof, with the hollow stem rotatably mounted in the frame member. A plurality of type wheels having printing characters thereon are rotatably mounted on the carrier and are symmetrically arranged in a circle on the side thereof which is opposite to the side having the hollow stem.

To effect printing of a preselected character, it is necessary to index the carrier (if it is not already properly indexed) so as to position the particular typewheel bearing the character selected for printing in a predetermined position with relation to the platen of the printer. To accomplish this indexing, the hollow shaft (secured to the carrier) is provided with gear means which are driven by a driving gear which in turn is secured to a first shaft rotatably mounted in the frame member. The remaining end of this shaft is provided with a first drive member, which is operatively connected to a first driving means, which indexes the carrier a predetermined angular amount depending upon the character selected to be printed. Thus, by rotating or indexing the first shaft a predetermined amount, one of the plurality of type wheels (the one bearing the preselected character) is indexed to said predetermined position, so as to be brought into cooperative engagement with the platen of the printer to print the preselected character.

Each of the typewheels rotatably mounted in the form of a circle on the disc-type carrier is provided with a driving gear concentrically formed on the typewheel. Each of these driving gears is in mesh with a sun gear whose rotating axis is coincident with the rotating axis of the carriage. The sun gear is secured to one end of a second shaft, which is rotatably mounted in the hollow stem secured to the carrier and also is rotatably mounted in the frame member. The remaining end of this second shaft is provided with a second drive member, which is operatively connected to a second driving means.

The first and second drive shafts mentioned above can be indexed simultaneously or independently of each other so as to index the carriage (when necessary) and rotate the typewheels (when necessary) so as to position the appropriate typewheel and character thereon, respectively, in a predetermined position for cooperative engagement with the platen of the printer. For example, if the character to be next printed is located on the same type wheel as the last character which was printed, then the carrier is not indexed (as the proper typewheel is already in position for printing); however, second drive shaft will be indexed so as to rotate the last-named typewheel and thereby bring the preselected character into proper printing position for cooperative engagement with the platen.

Means are provided to index the first and second drive shafts, which respectively control the indexing of the carrier and typewheels of the printing head. In the specific embodiment disclosed herein, the means comprise a separate closed driving loop system for each of the related drive members on the first and second drive shafts. Suitable cams are included in each of the closed loop systems, so that, through controlled rotation of selected ones of said earns, the bands in the loop systems can be made to travel in one direction or the opposite and thereby rotate or index their related drive shafts in one direction or the opposite to index and position the carrier and type wheels for cooperative engagement with the platen to thereby print the preselected character. It should be noted that each closed loop system may operate independently of or simultaneously with the other, and that the printing head according to this system is a. low mass system which can be operated at speeds sufficient to enable printing at approximately thirty prints per second.

These and other advantages of the invention will be more readily understood in connection with the following detailed description and the drawings, in which:

FIG. 1 is a general perspective view of the printing mechanism of this invention, showing the input gear, the printing head, and the clutch and solenoid means which are selectively actuated to move the bands which in turn control the positioning of the printing head in accordance with the character selected to be printed;

FIG. 2 is a plan view of the top of the printing mech anism shown in FIG. 1 and shows more details of the clutch and solenoid means used in selecting the character to be printed;

FIG. 3 is an elevational view of the rear of the printing mechanism shown in FIG. 1 and shows the arrangement of the anti-backup pawls for each of the cam shaft means which are actuated by the clutch and solenoid means;

FIG. 4 is an elevational view partly in cross section taken along the line 44 of FIG. 2 and particularly shows the cam shaft means which are actuated by the clutch and solenoid means and which control the movement of the bands which are operatively connected to the printing head;

FIG. 5 is an elevational view, partly in cross section, taken along the line 55 of FIG. 3, and shows more details of the cam shaft means for controlling the movement of the bands which are operatively connected to the printing head;

FIG. 6 is an exploded, perspective view of the elements in one of the cam shaft means;

FIG. 7 is an elevational view of one of the drive members which position the printing head, and also shows the means for securing the bands to the drive member;

FIG. 8 is an enlarged, elevational view of the printing head, partly in cross section, and is taken along the line 88 of FIG. 1;

FIG. 9 is an enlarged elevational view of the front of the printing head, looking from direction A of FIG. 8;

FIG. 10 is a side elevational view of one of the typewheels shown in FIG. 9;

FIG. 11 is a schematic diagram of the circuitry used to actuate the appropriate solenoid coils in response to input signals;

FIG. 12 is a character selection chart which shows the particular characters present on each typewheel; and

FIG. 13 is a character selection chart to be used in conjunction with FIG. 11 for determining the combination of clutch means to be actuated to print the particular character desired.

The printing mechanism, designated generally as 20, is shown in perspective in FIG. 1 and is supported in a frame consisting of front and

rear plates

22 and 24, respectively, which are secured in spaced parallel relationship to each other by spacer supports 26 and 28.

The input gear 30 is fixed to rotate with the input shaft 32, which is rotatably supported in the front and

rear plates

22 and 24, respectively. The input shaft 32 is part of the driving means which are effective for positioning the printing head, designated generally as 34, in printing relationship with a platen (FIG. 8) in response to the selection of a character to be printed.

The printing head 34, shown in FIGS. 1, 2, 5, 8, and 9, comprises, generally, a disc type carrier 36, which is operatively connected to the drive pulley 38 (FIG. 1), and also comprises a plurality of typewheels, designated T.W. 1 through T.W. 6, which are rotatably mounted on the carrier 36 (FIG. 9). The drive pulley 38 is effective to rotate the carrier 36 so as to position the particular typewheel (T.W. 1-T.W. 6) bearing the character to be printed in printing relation with a platen or card 48, as

shown in FIG. 8. In order to bring the selected character on the particular typewheel mentioned into a printing relation with the card 48, the following construction is used.

Each of the typewheels has a gear portion 40 and an eight-sided portion 42, on which eight different characters are formed, as shown in FIG. 10. Each of the gear portions 40 of the typewheels T.W. 1-T.W. 6 is in mesh with a sun gear 44 (FIG. 9), which is operatively connected to a drive pulley 46 (FIG. 5). When the drive pulley is rotated one way or the other, the sun gear 44 is effective to simultaneously rotate all the type wheels so as to position the selected character in printing relation with a platen or card 48 (FIG. 8).

The drive pulleys 38 and 46 may be rotated simultaneously and independently of each other, resulting in the carrier 36 and the sun gear 44 also being rotated simultaneously and independently of each other.

The positioning of the drive pulleys 38 and 46 is effected by the first and second drive means, designated generally as 50 and 52, respectively, as shown in FIG. 1. The first drive means, 50, is operatively connected by the band 54 to drive the pulley 38, which is effective for rotating the type carrier 36, as previously explained. The second drive means 52, is operatively connected by a band 56 to the drive pulley 46, which is effective for rotating the sun gear 44, which in turn simultaneously rotates all the type wheels. The combination of rotations of the carrier 36 and the typewheels is effective to position the character selected to be printed in a predetermined position for printing. The printing mechanism 20 may be used with a typical card punch machine having a platen 246 and a punch 247, as shown in FIG. 8. The platen 246 forces the punched card 48 and the ribbon 248 against the selected character on the typewheel to effect the printing.

Referring to the drive means in more detail, the input shaft 32, which is rotatably mounted in the front and

rear plates

22 and 24, respectively, is constrained against axial movement therein by locking collars (not shown).

.The input shaft 32 extends outwardly of the rear plate 24 and has a gear 58 fixed to rotate therewith (FIG. 3).

The gear 58 is in driving engagement with

gears

60 and 62, as shown in FIGS. 2 and 3. The gear 60 is fixed to a shaft 64, which is rotatably mounted in the front and

rear plates

22 and 24, and the gear 62 is fixed to rotate with a shaft 66, which is similarly rotatably mounted in the front and

rear plates

22 and 24. As the input gear 30 is rotated, it rotates the gear 58, which in turn rotates the shafts 64 and 66, which are the input shafts to the first and second drive means 50 and 52, respectively. The input shaft 32 and the shafts 64 and 66 always turn while the printing mechanism 20 is used.

Each drive means has a group of cam shafts located around its pertaining input shaft, which cam shafts are selectively rotated through clutch means on the input shafts. For example, there are three cam shafts, 68, 70, and 72, each of which is rotatably mounted in the front and

rear plates

22 and 24, respectively, and whose axes of rotation are parallel to and equidistantly spaced from the axis of the input shaft 64 of the first drive means 50, as shown in FIGS. 3 and 4.

The input shaft 64 has thereon three separate clutch means, designated generally as 74, 76, and 78, which are effective to selectively connect the shaft 64 to the

cam shafts

68, 70, and 72 (FIGS. 2, 3, and 4), respectively, to impart rotation thereto, as will be described later. Each clutch means is a standard spring-type clutch member, such as a Series C, On-Olf Clutch manufactured by Curtiss-Wright Corporation.

Similarly, the input shaft 66 of the second drive means 52 has associated therewith three cam shafts, 80, 82, and 84, which are each rotatably mounted in the front and

rear plates

22 and 24, respectively, and the axes of rotation of which are parallel to and equidistantly spaced from the input shaft 66.

The input shaft 66 also has thereon three separate clutch means, similar to those on the input shaft 64, and they are designated generally as 86, 88, and 90, as shown in FIG. 2, and are effective to selectively connect the shaft 66 to the

cam shafts

80, 82, and 84, respectively, to impart rotation thereto.

The arrangement of the clutch members on their respective input shafts is best shown in FIG. 5. All of the clutch members are alike, and an explanation of one will suffice for all. The clutch member 86, for example, consists of an output member 92, which is rotatably mounted on the input shaft 66 and which is secured to rotate with a gear 94, which also is rotatably mounted on the shaft 66. The clutch input member 96 is fixed to rotate with the shaft 66 by a screw 98.

The central sleeve 100 of the clutch member 86 provides the coupling between the input member 96 and the output member 92 when the clutch member is actuated. Normally, when the sleeve 100 is free to rotate, the coupling of the input member 96 to the output member 92 is effected. When the sleeve 100 is restrained against rotation, the coupling between the input and

output members

96 and 92, respectively, is disconnected.

To eifect the coupling and uncoupling of the input and

output members

96 and 92, respectively, actuator means, generally designated 102, are provided, as shown in FIG. 4, and include a generally Y-shaped member 104, which is pivotally mounted on a shaft 106, which is .secured to the

frame plates

22 and 24. The member 104 has legs 108 and 110, which are adapted to engage equally-spaced and axially-aligned projections 112 on the periphery of the sleeve 100. A spring 114, which is secured to the leg 110 and the spacer support 26, urges the member 104 counter-clockwise, as viewed in FIG. 4, and thereby brings its leg 108 into abutting engagement with one of the projections 112 on the sleeve 100.

During the time that the sleeve 100 is so constrained, the output member 92 and its related gear 94 do not rotate with the input shaft 66. However, when the ac tuator means 102 is to be energized, the related solenoid 116 (which is secured to the spacer support 26 by a bracket 118) is energized and pulls the leg 120 to rotate the member 104 clockwise, as viewed in FIG. 4, thereby moving the leg 108 out of engagement with one of the projections 112 on the sleeve 100.

When the sleeve 100 is so released, it rotates clockwise, as viewed in FIG. 4, under the influence of an expandable clutch spring (not shown). The expandable clutch spring provides a gripping action between the clutch input member 96 and the output member 92 to rotate the latter along with its related gear 94 whenever the sleeve 100 is released. It should be noted that, due to the rotation of the Yshaped member 104, its leg 110 is moved towards the sleeve 100 while the leg 108 is moved away therefrom, and, during this time, the sleeve 100 rotates. In moving towards the sleeve 100, the leg 110 engages one of the spaced projections 112 and thereby stops the sleeve 100 after it has rotated forty-five degrees. The stopping of the sleeve 100 is effective to disengage the clutch output member 92 from a driving connection with the shaft 66.

The output member 92 and the gear 94 continue to rotate momentarily after the sleeve 100 has been stopped, as they lag somewhat behind the rotation of the sleeve 100. The momentum of the output member 92 and the gear 94 is effective to rotate them until one of the projections 172 (FIG. on the output member 92 engages the leg 108 or the leg 110, as the case may be, and abruptly stops its rotation, The output member 92 and the gear 94 are prevented from rebounding after stopping by anti-back-up pawls to be described later. When stopped, the projections 172 are in axial alignment with the projections 112, to which they are similar.

The forty-five-degree rotation of the output member 92 and the gear 94 is effective to rotate the associated cam shaft 80, which in turn is effective to rotate or index the pertaining drive pulley 46 by means to be explained later. The indexing of the drive pulley 46 is effective to rotate the sun gear 44 (FIG. 9), as explained previously. The solenoid 116 remains in the energized position, thereby keeping the leg .110 in engagement with a projection 112 on the sleeve until it is released by some input device 250 (that is, a card reader, a computer, or the like), which would indicate that a different character is selected for printing.

Each one of the separate

clutch members

74, 76, 78, 86, 88, and 90 has its own output gear 94, which is operatively connected to its respective cam shaft as follows. As shown in FIG. 5, the output gear 94 of the clutch member 86 is in mesh with a gear 122, which is fixed to the cam shaft 80. The output gear 94 of the clutch member 88 is in mesh with a gear 124, which is fixed to the cam shaft 82, and similarly the output gear 94 of the clutch member 90 is in mesh with a gear 126, which is fixed to the cam shaft 84.

In a similar manner, the output gear 94 of the clutch member 74 is in mesh with a gear 128, which is fixed to the cam shaft 68 (FIG. 2); the output gear 94 of the clutch member 76 is in mesh with a gear 130, which is fixed to the cam shaft 70; and the output gear 94 of the clutch member 78 is in mesh with a gear 132, which is fixed to the cam shaft 72.

As mentioned earlier, the first drive means 50, comprising the

clutch members

74, 76, and 78, which control the operation of the

cam shafts

68, 70, and 72, respectively, is effective for controlling the drive pulley 38, which positions the carrier 36 (FIG. 1). Each of the cam shafts is similar to the others in construction, except that their throws are different.

The cam shaft 72, which is typical of the cam shafts,

-is shown in FIGS. 1, 2, 4, and 6 and is composed of two sections (a and b), with the cam means designated gen erally as 134 mounted therebetween. Included in the cam means 134 are identical

cylindrical members

136 and 138, the member 136 being fixed to rotate eccentrically with the shaft section 72a, and the member 138 being fixed to rotate eccentrically with the shaft section 72b.

The cam means 134 also includes a crank 142, which has a central cylindrical portion with

shafts

144 and 146 extending outwardly from opposed sides thereof, the axes of the shafts being parallel to and equidistantly spaced from the axis of the central cylindrical portion, and said axes lying in a common plane also passing through a diametral line on the cylindrical portion. Suitable pulleys, such as 148 and 149, each having a grooved periphery 150, are rotatably mounted on the

shafts

144 and 146, respectively, prior to the shafts being inserted in holes in the

cylindrical members

136 and 138, respectively. A pin 152 passes through an opening 154 in the cylindrical member 136 and a hole 156 in the shaft 144 to secure the two members together, and, similarly, another pin 152 passes through the openings 154 and 156 to secure the shaft 146 and the cylindrical member 138 together.

When in assembled relationship, the cam shaft 72 and the cam means 134 rotate as a unit, the shaft 72 being rotatably supported in bearings (not shown) which are similar to the

bearings

158 and 160 for the cam shaft 84, which are mounted in the front and

rear plates

22 and 24, respectively, as shown in FIG. 5. The shaft sections 72a and 72b are in axial alignment when in assembled relationship.

The construction of the remaining cam shafts is similar to that shown in FIG. 6; however, the cam means 162, 164, 166, 168, and of the

cam shafts

68, 70, 80, 82, and 84, respectively, have different throws, as shown in FIG. 4. The throw of the cam means 164 of the cam shaft 70 is (+12), and the throw of the cam means 162 of the cam shaft 68 is (+2t), while the throw of the cam means 134 of the cam shaft 72 is (-21). This combination of throws is sufiicient to enable the carrier 36 to be positioned in any one of six positions to thereby position any one of the six typewheels (T.W. 1T.W. 6) in printing relation with the platen 246 (FIG. 8).

Each of the clutch means 74, 76, 78, 86, 88, and 90 may be positioned and held in one of two positions, off and on. For the first drive means 50, consisting of the clutch means 74, 76, and 78, only six combinations of clutch positions are necessary to produce the needed six positions of the carrier, as there are only six typewheels. Therefore, the ratio of the eccentricities of the cam means of the clutch means is 1:212 for the embodiment shown, enabling the carrier 36 to be positioned in any one of six different positions. In general, the cam means above is effective to index the carrier 36 an angular amount which is at least equal to 1/ n revolution or multiples thereof, in which n is the total number of typewheels carried by the carrier.

The ratio of the number of teeth in the output gear 94 of each clutch means relative to the pertaining gear on the cam shaft (such as the gear 132 on the cam shaft 72) is 4 to 1. Thus, when a clutch means is actuated and rotates forty-five degrees, the pertaining output gear is also rotated forty-five degrees, and the pertaining gear (such as the gear 130 on the cam shaft 72) drives the pertaining cam shaft one hundred and eighty degrees.

With a one-hundred-and-eighty-degree rotation of the cam shaft, the pertaining cam means thereon will also be rotated through one hundred and eighty degrees, with the result that the drive pulley, such as 38, will be rotated to an extent dependent upon the particular throw of the cam means employed. For example, if the clutch means 74, 76, and 78 of the first drive means 50 are in the off, or non-energized, state, shown in FIG. 4, in which each spring 114 urges a leg 108 into engagement with a projection 112 on the sleeve 100, then the follow ing relationships hold. When the clutch means 76 is energized via its pertaining solenoid 116, the cam shaft 70 is rotated through one hundred and eighty degrees and held in this new position as long as the pertaining solenoid 116 is energized. As the throw of the cam means 164 of the clutch means 76 is (+1t), it is effective through the band 54 and the drive pulley 38 to index or rotate the carrier 36 one sixth of a revolution counter-clockwise, as viewed in FIG. 4.

Similarly, if the clutch means 74, 76, and 78 are in the non-energized state, mentioned above, and the clutch means 74 alone is energized, then the cam shaft 68 is rotated through one hundred and eighty degrees and held in this new position as long as its pertaining solenoid 116 is energized. As the throw of the cam means 162 of the cam shaft 68 is (+2t), it is effective through the band 54 and the drive pulley 38 to index the carrier 36 two sixths of a revolution counter-clockwise, as viewed in FIG. 4. As there are six typewheels positioned on the carrier 36, each one sixth revolution thereof is effective to index a different typewheel into printing relation with the platen 246.

Finally, if the clutch means 74, 76, and 78 are in the unenergized state, mentioned above, and the clutch means 78 alone is energized, then the cam shaft 72 is rotated through one hundred and eighty degrees and held in this new position as long as the pertaining solenoid 116 is energized. As the throw of the cam means 134 of the cam shaft 72 is (-20, it is effective through the band 54 and the drive pulley 38 to index the carrier 36 two sixths of a revolution; however, the direction will be clockwise, as viewed in FIG. 4, which is opposite to the direction effected by the cam means 162 and 164.

While the clutch means 74, 76, and 78 of the first drive means 50 have been illustrated above as being actuated singly, they may be actuated in concert in any combination thereof. For example, the solenoids 116 of the pertaining clutch means 74 and 76 may be energized jointly to actuate the named clutch means jointly with their respective throws (+2t) and (+11) adding together to effect at (2+1) or three sixths revolution or indexing of the carrier 36 counter-clockwise.

If, during the time that the clutch means 74 and 76 are so actuated, the solenoid 116 pertaining to the clutch means 76 is deenergized, the clutch means 76 is again actuated and returns to the deener-gized state; however, the cam means 134 associated therewith will be effective to rotate or index the carrier 36 clockwise, as viewed in FIG. 4. When the solenoid 116 pertaining to the clutch means 76 is deenergized, the pertaining tensioned Spring 114 rotates the Y-shaped member 104 on the shaft 106 of the actuator means 102 counter-clockwise, as viewed in FIG. 4, thereby releasing the leg 110 from a projection 112 on the sleeve 100, permitting the clutch means 76 to be again actuated and to rotate the sleeve for forty-five degrees until another projection 112 thereon abuts against the leg 108. During the forty-five degree rotation when the clutch means 76 is actuated, its pertaining cam shaft 70 and cam means 164 are rotated one hundred and eighty degrees to effect an indexing of the carrier 36 clockwise for one sixth of a revolution, thereby subtracting from the three sixths revolution mentioned in the previous paragraph, when the solenoids 116 of both clutch means 74 and 76 were actuated.

The abutting of a projection 112 on the sleeve 100 against the leg 108, mentioned in the previous paragraph, is effective to disconnect the gear 94 from the input member 96 to thereby deactuate the clutch means 74. The inertia of the gear 94 in being driven is sufficient to rotate the member 92 (after the sleeve 100 is stopped) until a projection 172 (FIG. 5) on the member 92 is stopped by either leg 108 or leg 110, as the case may be. The projections 172 are equal in number to the projections 112 and are in axial alignment with the projections 112 when the pertaining cam shaft, such as 70, is locked against rebounding by a pawl, such as 174 in FIG. 3.

The pawls 174 are identical for each of the

cam shafts

68, 70, 72, 80, 82, and 84; therefore, a discussion of the pawl for the cam shaft 84 will suffice. As seen in FIG. 5, the cam shaft 84 extends outwardly from the rear plate 24 and has a cam 176 fixed thereto. All the cams 176 rotate counter-clockwise, as viewed in FIG. 3, along with their respective cam shafts.

Each cam 176 has two shoulders 178, spaced one hundred and eighty degrees apart, as shown in FIG. 3. As the cam rotates with its respective shaft, the pawl 180, which is pivotally mounted on a screw 182, is urged counter-clockwise (FIG. 3) against the periphery of the cam 176 by a spring 184. After the gear 94 is driven and the sleeve 100 is brought to a stop (to deactuate the clutch means) against either leg 108 or 110, as the case may be, inertia rotates the gear 94 and the output member 92 until a projection 172 thereon is also brought to a stop by abutting against either leg 108 or (FIG. 5). At this time, the cam 176 is aligned in the position shown in FIG. 3, in which the pawl drops into position against the pertaining shoulder 178 and prevents a clockwise rotation or rebounding of the related cam shaft, such as 84 in the example given.

As previously mentioned, rotation of the

cam shafts

68, 70, and 72 of the first drive means 50, singly or in combination, is effective through the band 54 and the drive pulley to index or rotate the carrier 36. Each of the cam means 162, 164, and 134 is so arranged that its maximum throw occurs when the cam means bears the same angular relationship to a fixed reference line; for example, the crank 142 (FIG. 6) of each cam means 134, 162, and 164 is positioned in FIG. 4 so that all the diametral lines along which the

shafts

144 and 146 are positioned are vertical. This is the normal, off, position, in which none of the solenoids 116 is actuated and all the clutch means of the first and second drive means 50 and 52 are held in the non-energized state, in which the legs 108 engage projections of the corresponding clutch means.

In this normal, off, position, the pulleys 148 of the cam means 162, 164, and 134 lie substantially in a common vertical plane which is parallel to the rear plate 24. Similarly, the pulleys 149 of the same previously named cam means lie in a common vertical plane which is parallel to the rear plate 24; however, the plane containing the pulleys 148 is closer to the rear plate 24 than is the plane containing the pulleys 149. The band portion 54a of the band 54 coming from the right side of the drive pulley 38, as viewed in FIG. 4, passes under the bottom of the pulley 148 of the cam means 162, then over the top of the pulley 148 of the cam means 134, and then under the bottom of the pulley 148 of the cam means 164. From the last-named pulley 148, the band portion passes through an opening (not shown) in a bracket 186 (L-shaped in cross section) secured to the front plate 22. A clamp 188, resting on the bracket 186, is used to secure the end of the band thereto.

The other band portion 54b of the band 54 comes from the left side of the pulley 38 and passes under the pulley 149 of the cam means 162 (FIG. 4), over the top of the pulley 149 of the cam means 134, and then under the pulley 149 of the cam means 164, whence it passes through a second hole (not shown) in the bracket 186, to be retained by a clamp 190, shown in FIG. 1. The band 54 is retained in the grooves 150 of the

pulleys

148 and 149.

Both

band portions

54a and 54b are secured to the drive pulley 38, as shown in FIG. 7. The end of the band portion 54b is inserted into a slot in the drive pulley 38, in which it is bent inwardly towards the shaft 194 and is retained by a screw 192. The end of the band portion 54:: is similarly retained in the drive pulley 38; however, the end is inserted on the side of the pulley opposite to that shown in FIG. 7.

From the above-described construction, it is apparent that the band 54 is secured to the drive pulley 38 to positively rotate it in two directions. The free length of the band portion 54a as measured from its end in the clamp 188 (FIG. 4) to the point at which it touches the drive pulley 38 will change as different ones of the clutch means are actuated. correspondingly, the free length of the band portion 5411 as measured from its clamp 190 (FIG. 1) to the point at which it touches the drive pulley 38 will also change as different ones of said clutch means are actuated. If the band portion 54a is pulled downwardly, as viewed in FIG. 4, its free length will increase, and the drive pulley 38 will be rotated clockwise. Of course, while it is so rotated, the free length of the band portion 54b will decrease a corresponding amount, and the portion 54b will move upwardly.

This equal upward and downward movement of the band 54, as viewed in FIG. 4, is obtained through the related cam means. For example, if the clutch means 74 is actuated, the cam shaft 68 will be rotated one hundred and eighty degrees counter-clockwise from the position shown to a position in which the pulley 148 will assume the lower position and the pulley 149 will assume the upper position, which is a complete reversal of positions each time the clutch means is actuated. The reversal of positions produces a downward movement on the band portion 54a and an equal upward movement on the band portion 54b, which cause the drive pulley 38 to be rotated clockwise, as viewed in FIG. 4, by an amount dependent upon the particular throw of its related cam means, which, for the cam means 162, is (+2t). Therefore, the carrier 36 would be indexed two sixths of a revolution and would remain there as long as the solenoid 116 for the clutch means 74 remains energized.

When the solenoid 116 named in the previous paragraph is deenergized, the clutch means 74 would again be actuated, and the related cam means 162 would again be rotated counter-clockwise for one hundred and eighty degrees, as viewed in FIG. 4, which would restore the

pulleys

148 and 149 to the positions shown in FIG. 4. In so returning, however, the band portion 54b would move downwardly, while the band portion 54a would move upwardly to rotate the drive pulley 38 counter-clockwise for two sixths of a revolution and thereby position one of the typewheels on the carrier 36 in printing relation with the platen 246 (FIG. 8).

The cam means 164 operates in the same manner upon the band 54 as just explained; however, the throw of the cam means 164 is only (+lt) instead of the (+2t) of the cam means 162. The throw of the cam means 134 is (2t), which causes the drive pulley 38 to be first rotated counter-clockwise, as viewed in FIG. 4, when the pertaining solenoid 116 is energized. Upon deenergization of the solenoid 116 for the clutch means 78, its cam means 134 will be rotated counter-clockwise for one hundred and eighty degrees to return the

pulleys

148 and 149 to the position shown in FIG. 4 and to rotate the drive pulley 38 clockwise.

The rotation of the cam means 162, 164, and 134 of the first drive means 50 is effective for causing the band 54 to wrap and unwrap around the drive pulley 38 to rotate it predetermined angular amounts. As the ends of the band 54 are fixed, a closed loop system is achieved whereby the band portions 54a and 5412 are always positively driven. In some situations, it may be necessary to spring-load one of the band portions to allow for slight variations in the lengths of the band portions during rotation of the

pulleys

148 and 149; however, with close machining tolerances in producing the printing mechanism, the spring-loading is generally not necessary.

An advantage of the mechanism as described so far is that each of the clutch means 74, 76, and 78 of the first drive means 50 operates in both an on state and an off state. As long as the solenoid 116 of the pertaining clutch means is energized, the clutch means stays in that selected state, or on state. When the named solenoid 116 is deenergized, the spring 114 pulls the leg (FIG. 4) out of engagement with the sleeve 100, releasing the sleeve 100, thereby actuating the clutch means again. The leg 108 of the actuator means 102 will then retain the clutch means in the off position.

The rotating or indexing of the drive pulley 38, previously described, is effective for indexing the carrier 36. The drive pulley 38 is fixed to rotate with the shaft 194 by a pin 196 (FIG. 7), and the shaft 194 is rotatably supported in the neck portion 198 of the front plate 22 and a plate 200, which are maintained in spaced, parallel rela tionship by

spacers

202 and 204, as shown in FIGS. 1 and 5. The shaft 194 is prevented from moving axially by locking collars 206, which are fixed to rotate with the shaft and are placed on opposed sides of the neck portion A driving gear 208 is also fixed to rotate with the shaft 194, as shown in FIG. 8, and the teeth of the gear 208 are in mesh with the teeth 210 formed on a tubular portion 212 of the carrier 36 to thereby rotate or index the carrier 36, as previously explained.

The tubular portion 212 of the carrier 36 is rotatably mounted on a shaft 214, which in turn is rotatably mounted in the neck portion 198 and the plate 200 and is restrained against axial movement therein by the locking

collars

216 and 218, which latter collar has a reduced portion 220, which serves as a spacer to keep the teeth 210 in alignment with the teeth of the gear 208 (FIG. 8). The sun gear 44, mentioned earlier, is pinned to one end of the shaft 214 by a pin 222, and the drive pulley 46 is pinned to the other end of the shaft 214. Whenever the drive pulley 46 is rotated or indexed, the sun gear 44 will also be indexed a corresponding angular amount. As the carrier 36 is rotatably mounted on the shaft 214, the carrier 36 and the sun gear 44 can be rotated simultaneously and independently of each other.

The carrier 36 is provided with six equally-spaced holes 224, which are located along a circle which is concentric with the axis of rotation of the sun gear 44, as shown in FIGS. 8 and 9. A circular plate 226, which is washershaped, has therein six holes which are in alignment with the holes 224 in the carrier 36 when positioned thereagainst. When so aligned, an insert bearing member 228, having an annular flange 230 therein, is inserted into each of the holes 224 and passes through the holes in the plate 226, the flange 230 abutting against the carrier 36, as shown in FIG. 8. The ends of the insert members 228 passing through the plate 226 are peened over, as at 232, to secure the insert members to the carrier 36.

The typewheels T.W. 1 to T.W. 6 are tubular and are rotatably mounted on the remaining ends 234 of the insert members 228, with the gear portion 40 of each typewheel in mesh with the sun gear 44. Each of the typewheels has, on one side thereof, an annular recess, which provides a shoulder 236, against which a screw 238 abuts to retain the typewheel on the end 234 of the pertaining insert member 228. The screw 238 is threadedly received in the insert member 228, which is dimensioned to provide a running clearance between the type wheel and the flange 230, as shown in FIG. 8. The sun gear 44 has an annular recess 240, in which a bearing 242 is inserted to receive a support shaft 244 (shown out of the bearing in FIG. 8), which provides support for the printing matrix 34 when the platen 246 pushes the sheet to receive the printing, such as the card 48, and the ink ribbon 248 into engagement with a character on the typewheel in printing relationship therewith.

The typewheels T.W. 1 to T.W. 6 are arranged on the carrier 36 in the positions shown in FIG. 9, which is viewed from the direction A of FIG. 8. FIG. 12 shows the arrangement of the characters formed on the specific typewheels. For example, the first or #1 sequence position for typewheel #3 is a blank (no character), and, going clockwise, as viewed in FIG. 9, the #2 Seq. No. from the chart (FIG. 12) is the letter Z with the #8 Seq. No. or the eighth face of the character portion 42 of the typewheel containing the character (-1-). Thus, with six typewheels each containing eight faces, a total of fortyeight characters is available for the printing head 34.

In order to index the typewheels so as to present any one of eight characters on a typewheel in printing relation with the platen of the printing apparatus, the second drive means 52 is effective to index the typewheels in any one of eight dilferent positions. The second drive means 52 is similar in construction to the first drive means 50; however, the cam means 166, 168, and 170 of the second drive means 52 have throws of (+2t), (+11), and (4t), respectively, as shown in FIG. 4. These throws are sufficient to obtain the eight combinations of throws necessary to position each typewheel in any one of eight positions.

The band 56 of the second drive means 52 is operatively connected to the related cam means by the technique previously described in relation to the band 54-. The band portion 56a, coming from the right side of the drive pulley 46, which is the output member for the second drive means 52, passes under the pulley 149 of the cam means 166 (FIG. 4), over the pulley 149 of the cam means 170, and under the pulley 149 of the cam means 168, and its end is secured to a bracket 193 (FIG. 1). The band portion 56b, coming from the left side of the drive pulley 46, as viewed in FIG. 4, passes under the pulley 148 of the cam means 166, over the pulley 148 of the cam means 170, and under the pulley 14-8 of the cam means 168, and its end is secured to a bracket 195. As the different clutch means of the second drive means 52 are actuated, their corresponding cam means will be effective to vary the free lengths of the

band portions

56a and 56b to rotate the drive pulley 46 according to the throws of the corresponding cam members, as previously explained in relation to the first drive means 50. As there are eight faces on each typewheel, a throw of (+12) of the cam means 168, for example, will rotate the drive pulley 46 and the sun gear 44 (FIG. 9), so as to simultaneously index all typewheels an angular amount equal to one eighth-revolution. In general, the cam means for the second drive means 52 is effective to index the typewheels by an angular amount which is at least equal to 1/ m revolution, or multiples thereof, in which m is the total number of characters on each typewheel.

The characters to be printed by the printing head 34 are dictated by the input device 250, which may be a computer, a card reader, etc., and the output therefrom may be in any desired code. In the disclosed embodiment, the output is in the form of the Hollerith code. An advantage of this code in the control of a printing mechanism is the small amount of electrical decoding necessary. FIG. 11 shows a simple diode matrix which is used to activate the particular solenoids 116 of the first and second drive means 50 and 52, respectively, which position the carrier 36 and the typewheels, respectively, to obtain the printing of the selected character as follows:

If the character selected to be printed is the number 1, the input device 250 delivers an electrical signal to line 1 in FIG. 11, which energizes solenoid 116(78), which is operatively connected to the clutch means 78 of the first drive means 50, which in turn indexes the carrier 36. The lines 0 to 9 represent the O to 9 positions in a standard tabulating card, while 11 and 12 represent the 11 and 12 zone positions in the card. The particnlar solenoid 116 energized receives its source of current from the input device 250. Each of the solenoids 116 has a resistor 252 in series therewith, as shown in FIG. 11, which resistor is normally shunted by a circuit through switches, as 254 (FIGS. 4 and 11) and is used for reducing the current supplied to the pertaining solenoid 116 to a lower level after the solenoid has been initially energized from the input device 250 and the leg has moved to allow its related contacts 258 to move away from the contact 256. Once the leg 120 of the actuator means 102 (FIG. 4) has been attracted to the solenoid 116 by a large initial current, only a small current is needed to supply the attractive force to maintain the leg 120 in the attracted position, and the smaller current also prevents the solenoid coil from burning out.

Reducing the current to the solenoid 116 is accomplished by the leaf switches 254, best shown in FIG. 4. The leaf switches 254 are the same for the clutch means 74, 76, 78, 86, 88, and 90, and each switch comprises a leaf spring 256, which engages a second leaf spring 258 to make an electrical connection therebetween as long as the solenoid 116 is in the non-energized state. In this state, the spring 114 (FIG. 4) is efiective to rotate the leg 120 to force the leaf spring 258 against the leaf spring 256 and thereby bypass the resistor 252 (FIG. 11) and make the electrical connection to the solenoid 116. When the solenoid 11 6 is energized, the leg 120 is attracted thereto, and the leaf spring 258 breaks away from the leaf spring 256, and thereafter the solenoid coil is supplied with reduced current through the resistor 252. When the current to the solenoid 116 is shut off by the input device 250, the spring 114 returns its pertaining leaf switch 254 to the position shown in FIG. 4.

Returning to the selection of characters to be printed, if the number 5 is to be printed, the current from the input device 250 will pass over code line 5 (FIG. 11) and through

diodes

260 and 262 to reach

code lines

8 and 9, respectively. Energization of code line 8 is effective for actuating the solenoid 116 of the clutch means 76, which indexes the carrier 36 one sixth-revolution, and energization of line 9 is elfective for actuating the solenoid 116 of the clutch means 90, which indexes the sun gear 44 to position the number 5 on T.W. 4 in printing relation with the platen 246 (FIG. 8).

To record the letter A on a standard tabulating card, row positions 12 and 1 are punched in the same column. This same coding technique is used in the present printing mechanism to print letters and characters. For example, from the chart in FIG. 13, the printing of the letter A (shown in the lower half of its enclosing square) requires .13 a the energization of code lines 12-1 (shown in the upper half of its enclosing square). From FIG. 11, when line 12 is energized from the input device 250, the solenoid 116(88) is energized to activate the clutch means 88, which is effective to index or rotate the typewheels so that when the carrier is also indexed, the letter A on T.W. 1 is positioned in printing relation with the platen 246. The carrier 36 is indexed upon energization of line 1 (FIG. 11), which is effective to activate solenoid 116(78) of the clutch means 78, which causes the carrier 36 to be positioned with the typewheel TLW. 1 in printing relation with the platen 246.

The carrier 36 and typewheel T.W. 1 will be held in printing relation with the platen 246 for the printing -of the letter A as long as the pertaining solenoids 116 previously mentioned are maintained in the energizedcondition by the input device 250. After the printing is effected, the solenoids are deenergized, and the pertaining clutch means 78 and 8-8 for the carrier 36 and the typewheels, respectively, are actuated to return the carrier 36 and the typewheel (T.W. 3) to the home position, as shown in FIG. 9 and as indicated by the chart in FIG. 13, in which -Home Position a blank or no character appears on typewheel T.W. 3 in printing relation with the platen 246.

If, in the previous example, a repeat printing of the character A is required, the pertaining solenoids 116 mentioned are first deenergized, as mentioned in the previous paragraph; however, due to a lag in response in the pertaining clutch means 78 and 88 in being actuated to return to the home position, a second energization of

code lines

12 and 1 of FIG. 11 from the input device 250 occurs, and the said solenoids 116 are again energized. This second energization of the solenoids 116 for the clutch means 78 and 88 is effective to keep the pertaining legs 120 of the clutch means attracted to the solenoids 116, so that the carrier 36 and the typewheels remain in the same position to repeat the printing of the letter A. This is a feature of the present invention, in that the carrier 36 and the typewheels are not required to go back to the Home Position after each character is printed and before the next character is printed.

Another feature of the present invention relating to the repeat feature disclosed in the previous paragraph is that, if an error occured in the printing of the selected character, the error would occur for only one cycle, because, upon reenergization of code lines through 12 (FIG. 11) from the input device 250, the correct solenoids 116 would be actuated to obtain the selected charcter.

The code lines 0 through 12 shown in FIG. 11 ai e arranged to energize particular solenoids as follows. Code line 1 is connected to the solenoid 116 of the clutch means 78, and code line 2 is connected to the solenoid 116 of the clutch means 74. Code line 3 is connected to code line 1 via the diode 264 and is also connected to code line '9 via the diode 268. Code line 4 is connected to code line 2 via the diode 272, and it is also connected to code line 9 via the diode 276. Code line 5 is connected to code line 8 via the diode 260 and is also connected to code line 9 via the diode 262. Code line 6 is connected to code line 2 via the diode 284 and is also connected to code line 8 the diode 286. Code line 7 is connected to code line 1 via the diode 288 and is also connected to code line 8 via diode 290. Code line 8 is connected to the solenoid 116 of the clutch means 76. Code line, 9 is connected to the solenoid 116 of the clutch means 90. Code line 0 is connected to code line 12 via the diode 292 and is also connected to code line 11 via the diode 294. Code line 11 is connected to the solenoid 116 of the clutch means 86, and code line 12 is connected to the solenoid 116 of the clutch means 88.

While the form of the invention shown and described herein is admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to confine the invention to the form or embodiment disclosed 14 herein, for it is susceptible of embodiment in various other forms.

What is claimed is: 1. In a printing apparatus of the type described, 5 frame means;

carrier means rotatably mounted in said frame means; a plurality of type wheels rotatably mounted on said carrier means,

each said type wheel having printing characters on the perimeter thereof; first drive means operatively connected to said carrier means and operative in response to the selection of a character to be printed to index said carrier means and position the particular one of said type wheels bearing the character selected to be printed in a predetermined position for printing; and

second drive means operatively connected to said type wheels and operative in response to the selection of said character to be printed to index said type wheels and thereby position said particular one of said type wheels so as to bring said character selected thereon in said predetermined position for printing;

said first drive means comprising:

a first output member rotatably mounted in said frame means and operatively connected to said carrier means to index the latter;

belt means having ends secured to said frame means, said belt means being secured between said ends to said first output member to form first and second lengths, and one of said lengths adapted to wrap around said first output member and thereby become shortened as the other of said lengths unwraps an equal amount from said output member to become lengthened and thereby rotate said first output member to index said carrier means;

and first cam means operatively connected to said first and second lengths and operative in response to said selection of the character to be printed to vary the lengths of said first and second lengths and thereby index said carrier means;

said second drive means comprising:

a second output member rotatably mounted in said frame means and operatively connected to said type wheels to index them;

second belt means having ends secured to said frame means and with said second belt means being secured between the ends thereof to said second output member to form first and second lengths of said second belt means and with one of said last-named lengths adapted to wrap around said second output member and thereby become shortened as the'other of said last-named lengths unwraps an equal amount to become lengthened and thereby rotate said second output member and index said type wheels;

and second cam means operatively connected to said first and second lengths of said second belt means, and operative in response to said selection of the character to be printed to vary said last-named lengths and thereby index said type wheels relative 60 to the carrier means.

2. The apparatus as claimed in claim 1 in which said first cam means comprises:

a plurality of cam shafts and a pair of cam members for each said shaft with said cam shafts being rotatably mounted in said frame means and each said pair of cam members being fixed to rotate with its related said cam shaft; said cam members of any one pair having identical throws which are located one hundred and eighty degrees apart on the related said cam shaft; the throws of said pairs of cam members being whole-number multiples of one another; one of said cam members of each said pair being in operative engagement with one length of said first and second lengths of said first belt means while the other cam member of said last-named pair is in 15 operative engagement with the remaining length of said first belt means,

each said cam shaft having a rest position and an actuated position which is one hundred and eighty degrees away from said rest position and with a one-hundred-and-eighty-degree rotation of said last-named shaft being effective to index said carrier means an angular amount which is at least equal to 1/n revolution where n is the total number of type wheels carried by said carrier means, and with predetermined combinations of said cam shafts in said rest and actuated positions being effective to position any one of said type wheels in said predetermined position for printand clutch means adapted to be driven by an input shaft and adapted when actuated to selectively rotate said cam shafts one hundred and eighty degrees to said actuated and rest positions to obtain said predetermined combination required by the said character selected to be printed.

3. The apparatus as claimed in claim 2 in which said second cam means is similar to said first cam means and comprises:

a plurality of cam shafts and pairs of cam members similar to the related elements of said first cam means except with said last-named cam members being in operative engagement with the first and second lengths of said second belt means,

each said cam shaft of said second cam means having a rest position and an actuated position which is one hundred and eighty degrees away from said rest position and with a onehundred-and-eighty-degree movement of said last-named shaft being effective to simultaneously index all said type Wheels by an angular amount which is at least equal to l/m revolution, where m is the total number of characters on the perimeter of one of said type wheels, and with predetermined combinations of said last-named cam shafts in said rest and actuated positions being effective to position any one of said characters on said type wheels in said predetermined position for printing;

and second clutch means adapted to be driven by a second input shaft in timed relation with said firstnamed input shaft and adapted, when actuated, to selectively rotate said cam shafts of said second cam means one hundred and eighty degrees to said actuated and rest positions to obtain said last-named predetermined combinations required by the said character selected to be printed.

4. The apparatus as claimed in claim 3 in which the number of pairs of cam members is three for said first and second cam means and the axes of the cam shafts for said first cam means are in spaced parallel relationship with one cam member of each said pair lying substantially in a plane perpendicular to said last-named axes and in operative engagement with one length of said first and 16 second lengths of said first belt means, and with the the other cam member of said last-named pairs lying substantially in a second plane parallel to and spaced from said first-named plane and with said last-named other cam members in operative engagement with the other length of said first and second lengths of said first belt means.

5. The apparatus as claimed in claim 3 in which each said clutch means includes a clutch member and actuator means for each said cam shaft,

said actuator means having a rest position and an actuated position With spring means to bias said actuator means to said rest position,

said actuator means including a solenoid member and being effective to actuate said clutch member to rotate the related cam shaft to said actuated position and hold said cam shaft in said actuated position as long as the related said solenoid is held in the energized state,

said spring means being effective upon the deenergization of the related said solenoid to return the related said actuator means to said rest position, which return movement of said actuator means is effective to again actuate the related said clutch member and thereby index the related cam shaft one hundred and eighty degrees to return it to said rest position.

6. The apparatus as claimed in claim 5 in which all said cam shafts are rotated in the same direction when actuated and said pairs of cam members are arranged on their respective cam shafts so that at least one of said pairs of cam members will cause its related said output member to be rotated in a direction opposite to that caused by the remaining said pairs of cam members for the respective said drive means.

7. The apparatus as claimed in claim 5 further including signal distribution network means comprising an input and output with said input including an input terminal corresponding to each row position of a standard tabulating card and said output including an output terminal for each said solenoid member and conductor means connecting each said output terminal with one of said solenoid members, and unidirectional switch means operatively connecting said input terminals with said output terminals so as to selectively energize the said solenoid members in accordance with the said character selected to be printed.

References Cited UNITED STATES PATENTS 748,421 12/1903 Robertson 1011 10 X 1,343,511 6/1920 Kelly 101--1 10 X 2,343,721 3/1944 Van Tuyl 101101 2,613,795 10/1952 Yutang 1971.1 2,688,916 9/1954 Baldwin. 2,757,775 8/1956 Hickerson 197-49 2,825,279 3/1958 Gottscho 101-110 X 2,853,940 9/1958 Mockenfuss et al. 101109 X 2,905,083 9/ 1959 Hickerson. 3,168,182 2/1965 Bernard et a1 197-55 3,291,041 12/1966 Burchfield et al.

WILLIAM B. PENN, Primary Examiner.