US3334719A

US3334719A - Miniaturized electrically operated printer having automatic carriage return

Info

Publication number: US3334719A
Application number: US340615A
Authority: US
Inventors: Howard Bernard
Original assignee: Mite Corp
Current assignee: Mite Corp
Priority date: 1964-01-28
Filing date: 1964-01-28
Publication date: 1967-08-08
Anticipated expiration: 1984-08-08
Also published as: GB1061179A

Description

1967 B. HOWARD 3,334,719

MINIATURIZED ELECTRICALLY OPERATED PRINTER HAVING AUTOMATIC CARRIAGE RETURN Filed Jan. 28, 1964 4 Sheets-Sheet 1 a a a a \1 a m \9 4 INVENTOR. SEEN/1E0 HOWAKD BY Oflfiuwm M W ATTOE/VEXS' Aug. 8, 1967 B. HOWARD MINlATURIZE-U ELECTRICALLY OPERATED PRINTER HAVING AUTOMATIC CARRIAGE RETURN 4 Si1eets--5heei Filed Jan. 28, 1964 NWN INVENTOR.

K m J 3,334,719 HAVING Aug. 8, 1967 s. HOWARD MINIATURIZED ELECTRICALLY OPERATED PRINTER AUTOMATIC CARRIAGE RETURN Filed Jan. 28, 1964 4 Sheets-Sheet 5 I- Q\ N w E Q N3 WW W N r 1 15: H a 5 QQ m3- w 3,334,719 ING Aug. 8, 1967 B. HOWARD MINIATURIZED ELECTRICALLY OPERATED PRINTER HAV AUTOMATIC CARRIAGE RETURN Filed Jan. 28, 1964 4 Sheets-Sheet 4 INVENTOR. Bt'E/VAED HOW/JED BY Z 82' United States Patent Ofiiice 3,334,719 Patented Aug. 8, 1967 3,334,719 MINIATURIZED ELECTRICALLY OPERATED PRINTER HAVING AUTOMATIC CARRIAGE RETURN Bernard Howard, Upper Saddle River, N.J., assignor to Mite Corporation, New Haven, Conn., a corporation of Delaware Filed Jan. 28, 1964, Ser. No. 340,615

12 Claims. (Cl. 197-49) ABSTRACT OF THE DISCLOSURE An electrically operated printer has a movable type body and selector mechanism with three solenoids for moving the same. Two solenoid cores carry pulleys and a third pulley acts as an output pulley movable on a path between the paths of the first two. A cable is fixed at one end and passes back and forth around the three pulleys. The third movable core carries no pulley, and instead is connected to the other end of the cable. The output pulley is mechanically coupled to move the type body in response to its own movement. It is carried at the end of a pivoted arm mounted on a shaft which carries an electrical switch arm slidable over a stationary sector-shaped insulation plate having switch contacts on which the switch arm slides for the provision of special functions, the said switch contacts corresponding to and acting to provide an electrical indication of the position of the type body. The latter is preferably a cylinder which is slidable on a splined shaft for both rotary and axial character selection, with one set of three solenoids providing rotary selection, and another set of three solenoids providing axial selection, with each having one of the aforesaid sector-shaped switches. There is also provision for automatic carriage return.

This invention relates to electrically operated printers, particularly but not necessarily for telegraphy.

The general object of the invention is to improve electrically operated printers. More particular objects are to provide such a printer which is very compact in dimension and relatively light in weight, thereby adapting it for airborne use and for portable military use.

Another object is to provide such a printer which prints in page form. The page may be narrow, compared to letter size, and the roll of paper used may be a roll of wide tape such as is used in some business machines.

In my copending application, Ser. No. 303,739, filed Aug. 22, 1963, and entitled, Electrically Operated Printer, I disclose a printer of small front dimension suitable for panel mounting, and elongated from front to back. This employs a solenoid-operated pulley and cable system for rotary and for axial character selection. One object of the present invention is to further improve such a printer, including the solenoid-to-cable arrangement, and the cable-to-type cylinder arrangement.

The printer employs a type cylinder which is eight characters long and eight characters around. There are three solenoids for ratory selection and another three for axial selection. There are additional solenoids for hammer type action and carriage return. The input is preferably a six-level Baudot code, and after conversion in suitable conversion circuitry forming no part of the present invention, there is a nine-wire supply to the printer, six wires for the six solenoids, a seventh for the hammer action, an eighth for a common return, and a ninth for a local battery supply. A further object of the present invention is to provide automatic switch means for controlling special functions, in response to unique combina tions of rotary and axial selection not used for the printing of a character.

The printer is a narrow page printer, and in the specific form shown the lines have a maximum length of twenty-six characters. The carriage return may be signalled as a special function, but in accordance with a further object of the present invention, if carriage return is not timely signalled, there is an automatic carriage return. This is preferably provided between words, in the event that a word ends between the twentieth and twenty-sixth character (or more generally between the Mth and the Nth character because obviously a different page width or different type size might be employed).

To accomplish the foregoing general objects, and other more specific objects which will hereinafter appear, my invention resides in the electrically operated printer elements and their relation one to another, as are hereinafter more particularly described in the following specification. The specification is accompanied by drawings in which:

FIG. 1 is a perspective view showing a printer employing features of the present invention;

FIG. 2 is a plan view of the mechanism, removed from the casing;

FIG. 3 is a vertical section taken approximately in the plane of the line 3-3 of FIG. 2;

FIG. 4 is an elevation looking in the direction of the arrows 4-4 of FIG. 2;

FIG. 5 is a vertical section taken approximately in the plane of the line 55 of FIG. 2;

FIG. 6 is a side elevation looking in the direction of the arrows 6-6 of FIG. 2;

FIG. 7 is a front View, with the casing and the paper removed;

FIG. 8 shows the stationary part of a sector switch which is used for special functions;

FIG. 9 shows the movable arm of the sector switch;

FIG. 10 shows three switches operated by a cam which turns with the lateral feed drum; and

FIG. 11 is a wiring diagram.

Referring to the drawing, and more particularly to FIG. 1, the printer mechanism is housed in a housing 12 adapted to be slid through an opening in a panel, with the front end 14 exposed in front of the panel. The portion 14 may be a door hinged at 16, and the top edge 18 may act as a tear strip for tearing paper 20. Alternatively the paper may be rewound on a reel not shown.

Without limitation, but rather as an example of the invention in a particular case, the front 14 is only fourand-three-quarters inches wide and three and one-half inches high, the body 12 being significantly less in dimension. The paper may be a wide tape with perforated edges such as is already used in certain business machines, and in the present case has a width of two and one-half inches.

Paper path The paper path may be described with reference to FIGS. 3 and 5 of the drawing, referring to which a paper roll is shown at 22, and paper leaving the same runs downward beneath a roller 24 carried on arms 26 pivoted at 28 and normally urging the paper downward by means of springs 30. The roller 24 yields in the event the paper tension becomes excessive.

FIGS. 4 and 6 show how the ends of the shaft 32 of the paper roll are held in appropriate bearing slots by means of liftable arms 34, these being pivoted at 36, and being normally held downward by over-the-center springs 38. The upper ends of the arms 34 have inwardly turned finger tabs 40 (FIGS. 2 and 4 6) to facilitate turning the arms out of the way as shown in broken lines at 34' in FIG. 4, when a new roll of paper is to be added.

Again referring to the paper path in FIGS. 3 and 5, the paper runs forward beneath the printer and is then printer, and therefore guided upward around the curved lower edge of a polished front plate 42. The paper passes between a type cylinder 44 and a hammer 46, and then to paper feed wheels carried on a shaft 48. These wheels are shown at 50 in FIGS. 2, 4 and 6, and preferably have blunt or rounded sprocket teeth which engage mating sprocket holes at the edges of the paper. The paper is held against the feed wheels by means of appropriate bifurcated shoes 52 which may be turned out of the way when threading a new roll of paper through the machine. For this purpose the shoes are carried on horizontal arms 54 pivoted on vertical pivots at 56, and provided with over-the-center springs 58 so that they remain in either operative or inoperative position.

Rotary selection The mechanism for rotary selection may be described by reference to FIG. 4 of the drawing. There are three solenoids 60, 62 and 64 having movable cores 66, 68 and 70. These are disposed in parallel relation and they point in the same direction. Core 66 carries a pulley 72, and core 68 carries a pulley 74. A third movable pulley 76 is disposed for movement on a path between the paths of the movable pulleys 72 and 74. A cable 7 8- is fixed at one end, as on an adjustable post 80, and then passes backand-forth around the three movable pulleyes 74, 76 and 72. The third movable core 70 is connected by means of a link 82 to a lever 84 pivoted at 86 and connected at its opposite end 88 to the other end of the cable 78.

The third movable pulley 76 is used for character selec tion, in this case to rotate the type body 44. For this purpose there is a cable 90 fixed at one end on an adjustable post 92, and passing around a pulley 94 like pulley 76 or coaxial and movable with pulley 76.

The cable then extends forward to and is secured around a drum 96. In simple form this drum could be on the splined shaft of the type cylinder, but in the present case it turns a gear 98 which meshes with a gear 100 on the type cylinder shaft 102. The gearing has a two-to-one stepup ratio, so that the drum 96 need be turned only a half turn.

The return movement is provided by a load spring. This could be a spiral spring acting on drum 96, but in the present case it is an elongated pull spring 104 anchored at the rear end of the frame on a post 106. The forward end of the spring is connected to a cable 108 which may be Wound in opposite direction and secured to drum 96, but which in this case is secured to a separate drum 110' of smaller diameter serving the same purpose. A small travel makes for a more uniform spring tension.

The solenoid cores 66 and 68 have heat shields 112. The solenoid stroke is limited by adjustable lock nuts or rods projecting from the rear ends of the solenoids. These are not shown in FIG. 4 but are like those shown at 114 in FIG. 6. In the present case, core 66 travels oneeighth inch, core 68 travels one-sixteenth inch, and core 70 travels one-fourth inch, thus providing rotation of the type cylinder in the ratio of one to two to four, the type cylinder having eight characters around. The pivot 86 of lever 84 is only one-third from the bottom, thus doubling the movement at 88, but this merely compensates for the fact that its motion is applied directly to cable 78, instead of through a motion-doubling pulley such "as 72 or 74.

Referring to FIG. 2, it will be seen that the selector cable 78 may be a flat tape or belt, and further that it is located well in from the side of the printer, as necessitated.

by the substantial diameter of the solenoid 60 and the two subjacent solenoids. The output cable or coupling cable 90, however, is preferably located at the side of the the coupling pulley 94 is axially displaced from its companion third pulley 76.

Referring now to FIG. 4, the third or concealed ribbon pulley 76 is preferably carried at the end of a pivoted arm which extends transversely of the solenoid axes, and this arm is mounted on a shaft 116, which shaft carries another such arm 118, which in turn carries the output pulley 94. Thus the pulleys 76 and 94 move equally, and provide the desired coupling through output cable to the drum 96 for rotating the gears 98 and and the splined shaft 102 and type cylinder.

Lateral or axial selection The solenoid arrangement for axial selection may be described with reference to FIG. 6 of the drawing. Here again there are three

solenoids

120, 122 and 124, with

movable solenoid cores

126, 128 and 130 respectively. Core 126 carries a selector pulley 132, and core 128 carries a selector pulley 134. There is a third pulley 136 disposed for movement on a path between the paths of the pulleys 132 and 134. A cable 138 is fixedly but adjustably mounted atone end, as on a post 140, and passes back and forth around the three

movable pulleys

134, 136, and 132.

The third core 130 is connected as by means of a link 142 to a lever 144 pivoted at 146 and connected at its opposite end 148 to the other end of the cable 138.

Here again the cores 126 and 128 have heat shields 150, and the solenoid stroke is adjustable by suitable lock nuts 114. In the present case the adjustment afiords a travel of one-eighth inch for core 126, one sixteenth inch for core 128, and one-fourth inch for core 130. The pivot 146 is so located on lever 144 that the motion at 148 is doubled, thereby compensating for the motion-doubling action of the selector pulleys 132 and 134.

The third movable pulley 136 may be considered to be an output pulley which is coupled to move the type body, in this case axially. This is done by means of a cable 152 which passes around a pulley 156 which is coaxial with and movable with the pulley 136. One end of cable 152 is connected to a character advance drum 154, and the other end extends forward and is turned around a guide pulley 158 to follow a horizontal path across the front of the printer, in this case, above the horizontal splined shaft 102 of the type cylinder.

Referring to FIG. 2, the cable 152 and take up drum 154 are located at the side of the printer, whereas the selector pulleys and cable 138 are located well in from the side, as shown at 132 and 138. This makes roomfor solenoid 120 and its two subject solenoids. The driven or output pulley 156 is displaced axially by mounting pulley 136 at the end of a generally upright pivoted arm 160, this being mounted on a shaft 162 carrying a similar arm 164 (best shown in FIG. 6) which carries pulley 156 for cable 152. The cable 138 may be a flat ribbon, but cable 152 is preferably round in section.

Referring now to FIG. 7, the round cable 152 extends across the front of the machine between guide pulleys 158.

and 166. It is connected at 168 to a slide 170 which is slidable on a horizontal guide rail 172. Slide 170 carries a thin flat yoke 174 received in a groove in the type cylinder 44, the latter being slidable on splined shaft 102. Yoke 174 straddles shaft 102, and shifts the cylinder axially or laterally without interfering with its rotative movement.

Refer-ring now to FIG. 4, the rearwardly extending end portion of cable 152 leaving the guide pulley 166 is connected to a suitable load spring or return spring. This could be a long pull spring (like spring 104 for cable 108), or it could be a rotatable drum which houses a spiral spring, but in the present case a bent-helical spring is employed. More specifically, there is a helical spring 176 one end of which is anchored on a fixed post 178, and the other end of which is connected at 180 to an arm 182 pivoted at 184. The other end of arm 182 carries a pulley 186 around which cable 152 passes, the end of the cable being secured on a fixed adjustable post 188. The spring 176 is bent to arcuate shape. It will be evident that as spring 176 tends to straighten, it moves pulley 186 rearward, and thus applies tension to cable 152. This spring arrangement has the advantage of providing substantially constant tension over a long travel. The travel The hammer action The hammer action is next described with reference to FIGS. 2-7. The hammer head 46 (FIG. 5) is carried at the upper end of a hammer arm 190, the lower end of which is enlarged to form a slide 192 (FIGS 5 and 7) which is slidable on a non-circular (in this case a rectangular) hammer shaft 194. The ends of shaft 194 are reduced to provide round journals received in bearings 196 (FIG. 7) in the side plates of the printer. Near one end the hammer shaft 194 has an upstanding arm 198 (FIGS. 4 and 7) to rock the same. Referring to FIG. 4, the shaft is rocked by a link 200 extending rearwardly to an arm 202 on a shaft 204.

Referring now to FIG. 5, there is a hammer actuating solenoid 206 having a core 208 connected by a link 210 to the upper end of a lever 212 mounted on a rock shaft 204. The lower end of the lever is connected to a load spring 214. The hammer solenoid 206 is between the character selection solenoids, as will be clear from FIG. 2.

Reverting now to FIG. 4, it will be evident that rocking of the shaft 204 causes the hammer to strike. A lost motion connection preferably is provided at the forward end of link 200, as shown at 201, so that the hammer stroke may be completed by inertia.

In FIG. 5 switch 54 is normally open, and is closed momentarily each time the hammer acts. Screw 304, carried by link 210, is adjustable to set the timing of the switch, the purpose of which is described later.

Character advance Referring to FIG. 5, the return movement of the hammer solenoid is employed for the desired step-by-step character advance of the type cylinder. More specifically, the generally upright lever 212 carries a character advance pawl 216 engaging a ratchet wheel, a fragment of which is shown at 218. Force for the desired movement is provided by spring 214. As will be seen in FIG. 3, the ratchet wheel 218 is also provided with a check pawl 220. It also has a stop post 222 which engages an adjustable stop screw 224 to limit the return movement of the type cylinder during carriage return.

Referring now to FIG. 2, character advance pawl 216 engages ratchet wheel 218. This is mounted on a shaft passing through a long fixed bearing 226, the said shaft at its outer end carrying the character advance drum 154 previously mentioned. From inspection of FIG. 6 it will be evident that the resulting step-'by-step counterclockwise movement of drum 154 results in a step-by-step character advance of the type cylinder across the paper, this advance taking place during the return movement of the hammer. This does not affect the character selection movement of the type cylinder, because of the coupling action aflForded by the coupling pulley 156. The two motions are independent, although they are combined in one cable 152.

The hammer is advanced with the same step-by-step movement across the paper. For this purpose a hammer advance cable is provided near the bottom of the printer Referring to FIG. 5, the cable is secured to the hammer at 228. This is behind the broad flat hammer shaft 194, and therefore the horizontal front portion of the cable is not visible in FIG. 7. However, the cable extends between a guide pulley 230 (FIG. 4) on one side of the machine and a guide pulley 232 (FIG. 6) at the other side of the machine. In FIG. 6 the hammer cable 234 then extends to the lower side of drum 154 (or a drum exactly like it and immediately adjacent it). The drums turn together and move the cables equal amounts, so that the hammer is advanced along with the type cylinder, but

of course does not partake of the back and forth character selection movements of the type cylinder.

Referring now to FIG. 4, the hammer cable 234 leaving the guide pulley 230 extends rearward and is connected to a long load spring or return spring 236, the rear end of which is connected to a post 238 on the printer frame.

Carriage return and line feed Carriage return and line feed are produced by actuation of another solenoid shown at'240 in FIG. 5. It is below hammer solenoid 206, and both are between the selector solenoids, as will be clear from FIG. 2. Its core 242 (FIG. 5) moves a link 244 connected at 245 to the lower end of an upright lever 246 pivoted at 248. The upper end of lever 246 carries a line feed or paper feed pawl 250 which cooperates with a ratchet wheel 252 mounted on shaft 48 which carries the paper feed wheels 50 (FIG. 2) previously referred to. FIG. 7 shows the ratchet Wheel 252 on shaft 48, and also a companion detent wheel 254. Referring now to FIG. 3, detent wheel 254 is engaged by a detent roller 256 on an angle lever 258 biased by a spring 260, the effect of this being to fix the line-to-line position of the paper being fed by the paper feed wheels, with adjustment at 259.

Reverting to FIG. 5, the line feed pawl 250 and its lever 246 are bodily urged rearward by a pull spring 262, the rear end of which is secured at 264. The line feed pawl 250 is biased by a spring 266 and the effective length :of its stroke may be controlled by an eccentrically mounted camming pin 268 mounted on a rotatable member 270 and bearing against a camming surface 272 on the feed pawl 250. In this way, the spacing between successive lines may be adjusted because the pin 268 may be used to delay the effective point of engagement between the pawl and the ratchet wheel 252.

For purpose of carriage return, the character-advance pawl 216 is disengaged so that the return spring 176 (FIG. 4) may pull the type cylinder back to starting position at the left edge of the paper. For this purpose the holding pawl 220 (FIG. 3) also must be disengaged.

Referring to FIG. 5, pawl 216 is normally urged downward by a pull spring 274. It is connected to an arm 276, the lower end of which is in the path of a pusher 278 carried by a forward extension of the link 244. This extension is guided by a slot 280 movable on a fixed pin 282. It will be evident that when the carriage-return, linefeed solenoid is energized and link 244 is pulled to the right, the pusher 278 moves finger 276, which in turn disengages the character-advance pawl 216.

Referring now to FIG. 3 of the drawing, the check pawl 220 is normally urged into engagement by a pull spring 284. It is connected to a finger 286, the upper end of which is in the path of the pusher 278 previously referred to. The horizontal link 2 44 of the carriage-return, line-feed solenoid 240 has been omitted in FIG. 3, but the pusher 278 is shown and it will 'be understood that when the solenoid is energized the check pawl 220 is disengaged, at the same time that the feed pawl 216 is disengaged :as described in connection with FIG. 5. The disengagement of both pawls results in the instantaneous return of the type cylinder back to its start position.

Attention may be directed to the switch S2 in FIG. 5, which is'normally open but is permitted to close when solenoid 240 is energized. It is normally held open by a screw 308 carried by the link 244. The position of the screw is adjustable so that the timing of the closing of switch 52 may be set as desired. The function of this switch will be described later, but for the present it may be mentioned that it is a holding switch for the carriage-return, line-feed operation, that is, when solenoid 240 is energized it remains energized until the circuit is opened by the opening of another switch which is responsive to return of the print cylinder to starting position.

Ink ribbon It is common to employ an ink ribbon between the hammer and the paper, but for simplicity the ink ribbon and its spools and their ribbon feed mechanism are not shown. Indeed they may be entirely omitted when using a special paper of a type which carries concealed inking material which is exposed where hit. Such impact-sensitive paper is self-inking, thus dispensing with the use of an ink ribbon. For purpose of the present disclosure, it may be assumed either that special impact-sensitive paper is used, or that ink ribbon mechanism is used but is not shown 'because it may be conventional.

The electrical circuitry Referring to FIG. 11, the six character-selection solenoids are indicated at Ll through L6, and the supply conductors leading to the-m are marked 16. The hammer solenoid is shown at 206, and the carriagereturn, linefeed solenoid is shown at 240. In the present case, the hammer solenoid is energized through a wire marked 7, and there is a common return wire marked 3. There is also a local battery supply wire marked 9. The common return 8 is also the negative side of the battery. Connections are made through a multiple pin connector at the back of the unit, marked 350 in FIGS. 26.

The original signal is made up of sequential pulses in accordance with a six-level Baudot code, and these are converted in appropriate conversion circuitry to provide the desired simultaneous outputs for the six selector solenoids.

The relation between the six solenoids shown in FIG. 11 and those shown in FIGS. 1-7 is not critical, because the conductors 1-6 may be used as desired. However, in the specific case shown, solenoids L3, L4, and L5 are for lateral selection, and solenoids L1, L2, and L6 are for rotary selection. Diodes are connected in shunt around the solenoid coils and serve to prevent induced voltages from affecting other nearby equipment.

Half the type cylinder is used for letters, and the other half is used for figures. There are excess spaces which are not used, and special combinations of rotary and lateral selector positions may be reserved to initiate so-called special functions. When dealing with a five-level Baudot code, the sixth solenoid (which turns the type cylinder a half revolution to select as between letters and figures) may be energized as a special function. In the present case that is not necessary because a sixth input conductor operates the sixth solenoid. One special function which remains, however, is carriage-return, line-feed.

To provide for this and any other desired special functions, the printer is provided with electrical switch mechanisms sensitive to the positions of the type cylinder. FIG. 8 shows an insulation stator 310 having eight printed contacts 312. These lead at their lower ends to connections through the insulation board to wires of a harness. In the present case only two wires are used, as described later. There is also a printed arcuate strip 314 which extends upward to another connection to a wire on the opposite side of the board. The exact rotative position of board 310 may be adjusted, as indicated by the slots 316 which receive mounting screws.

The lower end of the board is secured outside the stationary bearing of either shaft 116 (FIG. 4) or shaft 162 (FIG. 6). The location of these sectors is shown at S12 in FIG. 4 and at S9 in FIG. 6. The letters designate the sector switch generally. The location of the sector switches is also indicated in plan in FIG. 2 at S9 and S12, the movable switch arms being omitted to simplify the draw- The movable switch arm is shown in FIG. 9, there being an arm 318 which is secured to its shaft at a hub 320, which may be provided with a clamp screw or set screw or the like, not shown. It carries a bowed spring contact 322, the upper end of which slides over the stationary contacts 312 (FIG. 8), and the lower end of which slides over the arcuate sector 314, thereby completing a circuit which is indicative of the position of the type cylinder (the lateral position at switch S9, and the rotary position at switch S12).

For automatic rather than a signalled carriage return, an indication of the position of the type cylinder in its step-by-step travel across the paper is needed. Referring to FIG. 6, in the present case this is accomplished by switches S1, S10, and S11, which are operated by a cam which turns with the drum which receives the cables which move the type cylinder and the print hammer across the paper. The switch S1 marks the starting position at the beginning of a line. The switch S10 marks the end of a line of maximum length. The switch S11 corresponds to the alert position. In the particular case here shown, the switch S11 corresponds to the twentieth character and the switch S10 to the twenty-sixth character.

This drum switch arrangement is shown in greater detail in FIG. 10 of the drawing. Referring to that figure, switches S1, S11, and S10 are fixedly mounted on an insulation plate 330, which is locked by means of a clamp screw 332 on the stationary bearing 226 (FIG. 2) of the lateral feed drum. The position of plate 330 is bodily ad- The operation may be described with reference to FIG.

11. Sector switch S9 is controlled by the positioning of the lateral solenoids, and sector switch S12 is controlled by the positioning of the rotary solenoids. The combinations of the three lateral solenoids provide eight lateral positions of the type cylinder, giving eight positions on sector switch S9. The rotary positioning solenoids provide eight rotary positions of the type cylinder, and move the arm of sector switch S12 to eight positions. With these two sector switches S12 and S9, it is possible to recognize any one of 64 possible combinations, some of which are not used for a character and may be used for a special function.

The carriage-return, line-feed function usually is initiated upon the receipt of a signal for that purpose. This signal energizes solenoid L2 if the type cylinder is in letters position. Solenoid L2 positions the arm of sector switch S12 to the number 1 position, and because sector switch S9 is at 0, the carriage-return, line-feed solenoid 240 is energized when the character advance switch S4 is closed by operation of the hammer. When the carriage-return, line-feed solenoid 240 pulls in, it is held in the energized position by the carriage-return, line-feed hold switch S2. At the beginning of a new line a cam on the character positioning mechanism or drum opens drum switch S1, thereby releasing the holding circuit to the carriage-return, line-feed solenoid 240; Should a carriage-return, line-feed signal be received with the type cylinder in the figures position, solenoids L6 and L2 are energized and the arm of sector switch S12 moves to the number 5 position. This switch position is Wired to the number 1 position, accomplishing the same function as when the cylinder is in the letters position.

If no signal for carriage return is received, there is an automatic carriage return. This could most simply be provided at the end of the maximum length of line, which in this case is twenty-six characters. However, that would break up words at undesired and abnormal points. To help minimize such undesired breaking up of words, the present mechanism is alerted at an earlier point, say at the twentieth character, and thereafter causes carriage return in the event that a signal for space is received, which ordinarily indicates the separation between two words. It will be understood that the numbers 20 and "26 are exemplary, and that considered more generally the mechanism is alerted at what may be termed the Mth character, and the maximum permissible length of line would be at the Nth character.

For this purpose the character advancing mechanism closes the 20th character drum switch S11, and the first subsequent space is recognized by the two sector switches S9 and S12. T recognize the space signal, lateral solenoid L3 is energized, moving the arm of sector switch S9 to position"4. As this is the only solenoid energized, the sector switch S12 is at the 0 position, and when the character advance solenoid plunger closes switch S4, the carriage-return, line-feed function occurs. The carriage-return, line-feed solenoid is held in the energized position by carriage-return, line-feed hold switch S2, until drum switch S1 is opened at the beginning of a new line, as described above. Should a space signal be received while the type cylinder is in the figures position, solenoids L6 and L3 are energized, and the arm of sector switch S12 moves to the number 4 position. This sector switch position is wired to the 0 position, thereby accomplishing the same function as when the type cylinder is in the letters position.

If no signal for space or for carriage return is received by the end of the line the character advance mechanism closes drum switch S when the drum is positioned to the 26th character. On receipt of the hammer pulse, the hammer solenoid plunger closes switch S4. When switch S4 and drum switch S16 are closed during the same period of time, the carriage-return, line-feed solenoid is energized, returning the hammer and the type cylinder to start position, as well as advancing the paper. The carriage-return, line-feed solenoid is held energized once it is pulsed by the carriage-return, line-feed hold switch S2. At the beginning of a new line, the solenoid is released as described above.

It is believed that the construction and method of operation of my improved electrically operated printer, as well as the advantages of the same, will be apparent from the foregoing detailed description. It will also be apparent that while I have shown and described the invention in a preferred form, changes may be made without departing from the scope of the invention, as sought to be defined in the following claims.

I claim:

1. An electrically operated printer comprising .a type body, and selector mechanism for moving the same, said mechanism comprising three solenoids having movable cores, the first and second movable solenoid cores each carrying a pulley, a third movable pulley being disposed for movement on a path between the pathsof the first two movable pulleys, acable fixed at one end and passing back and forth around the three movable pulleys, the third movable core carrying no pulley and instead being operatively connected mechanically directly to the other end of the cable, said third movable pulley acting as a movable output pulley and being mechanically coupled to move the type body in response to its own movement.

2. An electrically operated printer as defined in claim 1, in which the type body is a cylindrical type body s1id able on a splined shaft for rotary and axial character selection, and in which the set of three solenoids is used for rotary selection, and in which there is a second similar set of three solenoids which is used for axial selection, and in which there are two additional solenoids, one having linkage for causing hammer action and character advance, and the other having linkage for causing carriage return and line feed.

3. An electrically operated printer as'defined in claim 1, in which the type body is a cylindrical type body slidable on a splined shaft for rotary and axialcharacter selection, and in which the set of three solenoids is used for rotary selection, and in which there is a second similar set of three solenodis which is used for axial selection, and in which there are two additional solenoids, one having linkage for causing hammer action and character advance, and the other having linkage for causing carriage return and line feed, the rotary selection being provided by a cable fixed at one end and passing about a pulley mechanically moved with the aforesaid movable output pulley of the first set of solenoids and leading to a cable drum having an oppositely movable return cable connected to a load spring, the type body being axially moved by a cable having one portion connected to a load spring, the other end of said cable being connected to a character advance drum having a ratchet wheel and a pawl operated by the hammer solenoid, said cable passing about a pulley mechanically moved with the movable output pulley of the second set of solenoids.

4. An electrically operated printer comprising a type body, and selector mechanism for moving the same, said mechanism comprising three solenoids having movable cores, the first and second movable solenoid cores each carrying a pulley, a third movable pulley being disposed for movement on a path between the paths of the first two movable pulleys, a cable fixed at one end and passing back and forth around the three movable pulleys, the third movable core carrying no pulley and instead being operatively connected mechanically directly to the other end of the cable, said third movable pulley acting as a movable output pulley and being mecahnically coupled to move the type body in response to its own movement, said third movable pulley being carried at the end of :a pivoted arm extending transversely of the solenoid axes, said arm being mounted on a shaft carrying an electrical switch arm slidable over a stationary sector-shaped insulation plate having switch contacts on which the switch arm slides for the provision of special functions, said switch contacts corresponding to and acting to provide an electrical indication of the position of the type body.

- 5. An electrically operated narrow page printer as defined in claim 2 comprising a paper-roll, solenoid means responsive to a circuit controlled by said sector-shaped switch to feed the paper for line feed and to cause carriage return, said type body being movable across the paper to print lines having a desired length between M characters and N characters long, circuit means made efietcive by the aforesaid sector-shaped switch beginning with the Mth character, whereby the occurrence of a received signal for a space between the printing of characters causes carriage return and line feed, and an additional limit switch means made eifective by the aforesaid sector-shaped switch on reaching the Nth character to cause carriage return and line feed it not caused sooner by a received signal.

6. An electrically operated pirn-ter as defined in claim 4, in which the type body is a cylindrical type body slidable on a splined shaft for rotary and axial character selection, and in which the set of three solenoids is used for rotary selection, and operates the sector-shaped switch, and in which there is a second similar set of three solenoids and a sector-shaped switch which set is used for axial selection, an additional solenoid and linkage operated thereby for causing carriage retmn and line feed, said additional solenoid being controlled by said sector shaped switches, circuit means made effective beginning with the Mth character, whereby the occurrence of a signal for a space between the printing of characters as recognized by said sector-shaped switches causes carriage return and line feed, and an additional means effective on reaching the Nth character to cause carriage return and line feed if not caused sooner by a received signal.

7. An electrically operated printed as defined in claim 2, in which the type body is a cylindrical type body slidable on a splined shaft for rotary and axial character selection, and in which the set of three solenoids is used for rotary selection and operates one sector-shaped switch, and in which there is a second similar set of three solenoids and a sector-shaped switch which set is used for axial selection, an additional solenoid and linkage operated thereby for causing carriage return and line feed, said additional solenoid being controlled by said sectorshaped switches, the rotary selection being provided by a cable fixed at one end and passing about a pulley mechanically moved with the said movable output pulley of the first set of solenoids and leading to a cable drum for rotating the splined shaft and type body, said cable drum having an oppositely movable return cable connected to a long spring, the type body being axially moved by a cable having one portion connected to a return spring, the other end of said cable being connected to a character advance drum having a ratchet wheel and a pawl operated by the hammer solenoid, said cable passing about a pulley mechanically moved with the movable output pulley of the second set of solenoids, electrical switches operated by said drum at the Mth and Nth character, circuit means including said sector-shaped switches made effective beginning with the Mth character, whereby the occurrence of a signal for a space between the printing of characters as recognized by said sector-shaped switches causes carriage return and line feed, and an additional means effective on reaching the Nth character to cause carriage return and line feed if not caused sooner by a received signal.

8. An electrically operated printer comprising a type body, and selector mechanism for moving the same, said mechanism comprising three solenoids having movable cores disposed in parallel relation and pointing in the same direction, the first and second movable solenoid cores each carrying a pulley, a third movable pulley being disposed for movement on a path between the paths of the first two movable pulleys, a cable fixed at one end and passing back and forth around the three movable pulleys, the third movable core carrying no pulley and instead being connected to a lever pivoted at an intermediate point and connected at its opposite end directly to the other end of the cable, said third movable pulley acting as a movable output pulley and being carried at the end of a pivoted arm extending transversely of the solenoid axes, said arm being mounted on a shaft carrying another such arm which is located at the side of the printer and is coupled to a cable leading to the type body for moving the same.

9. An electrically operated printer as defined in claim 8, in which the type body is a cylindrical type body slidable on a splined shaft for rotary and axial character selection, and in which the set of three solenoids is used for rotary selection, and in which there is a second similar set of three solenoids which is used for axial selection, and in which there are two additional solenoids, one having linkage for causing hammer action and character advance, and the other having linkage for causing carri-age return and line feed, the rotary selection being provided by .a cable fixed at one end and passing about a pulley mechanically moved with the aforesaid movable output pulley of the first set of solenoids and leading to a cable drum having an oppositely movable return cable connected to a load spring, the type body being axially moved by a cable having one portion connected to a load spring, the other end of said cable being connected to a character advance drum having a ratchet wheel and a pawl operated by the hammer solenoid, said cable passing about a pulley mechanically moved with the movable output pulley of the second set of solenoids, said cable drum being located at one side of the printer, said character advance drum being located at the other side of the printer, and in which the solenoids of the first set are superposed at one side of the printer, the solenoids of the second set are superposed at the other side 12 of the printer, and the two additional solenoids are super. posed therebetween.

10.. An electrically operated printer comprising a type body, and selector mechanism for moving the same, said mechanism comprising three solenoids having movable cores disposed in parallel relation and pointing in the same direction, the first and second movable solenoid cores carrying pulleys, a third movable pulley being disposed for movement on a path between the paths of the first two movable pulleys, a cable fixed at one end and passing back and forth around the three movable pulleys,

the third movable core being connected to a lever pivoted at an intermediate point and connected at its opposite end directly to the other end of the cable, said third movable pulley acting as a movable output pulley and being carried at the end of a pivoted arm extending transversely of the solenoid axes, said arm being mounted ona shaft carrying another such arm and pulley for a cable leading to the type body, said latter arm and pulley being located at the side of the printer the travel of the solenoid cores being so adjusted that they produce motions of the type body in the ratio of one to two to four, said shaft also carrying an electrical switch arm slidable over a stationary sector-shaped insulation plate having switch contacts on which the switch arm slides for the provision of special functions, said switch contacts corresponding to and acting to provide an electrical indication of the position of the type body.

11. An electrically operated printer as defined in claim 10, in which the type body is a cylindrical type body slidable on a splined shaft for rotary and axial character selection, and in which the set of three solenoids is used for rotary selection, and in which there is a second similar set of three solenoids which is used for axial selection, and in which there are two additional solenoids, one having linkage for causing hammer action and character advance, and the other having linkage for causing carriage return and line feed.

12. An electrically operated printer as defined in claim 10, in which the type body is a cylindrical type body slidable on a splined shaft for rotary and axial character selection, and in which the set of three solenoids is used fior rotary selection, and in which there is a second similar set of three solenoids which is used for axial selection, the solenoids of the first set being superposed at one side of the printer, the solenoids of the second set being superposed at the other side of the printer, and two additional superposed solenoids being disposed therebetween, one having linkage for causing hammer action and character advance, and the other having linkage for causing carriage return and line feed.

References Cited ROBERT E. PULFREY, Primary Examiner.

E. S. BURR, Assistant Examiner.

Claims

1. AN ELECTRICALLY OPERATED PRINTER COMPRISING A TYPE BODY, AND SELECTOR MECHANISM FOR MOVING THE SAME, SAID MECHANISM COMPRISING THREE SOLENOIDS HAVING MOVABLE CORES, THE FIRST AND SECOND MOVABLE SOLENOIDS CORES EACH CARRYING A PULLEY, A THIRD MOVABLE PULLEY BEING DISPOSED FOR MOVEMENT ON A PATH BETWEEN THE PATHS OF THE FIRST TWO MOVABLE PULLEYS, A CABLE FIXED AT ONE END AND PASSING BACK AND FORTH AROUND THE THREE MOVABLE PULLEYS, THE THIRD MOVABLE CORE CARRYING NO PULLEY AND INSTEAD BEING OPERATIVELY CONNECTED MECHANICALLY DIRECTLY TO THE OTHER END OF THE CABLE, SAID THIRD MOVABLE PULLEY ACTING AS A MOVABLE OUTPUT PULLEY AND BEING MECHANICALLY COUPLED TO MOVE THE TYPE BODY IN RESPONSE TO ITS OWN MOVEMENT.