US3393785A

US3393785A - Keyboard operated spring powered type wheel recorder

Info

Publication number: US3393785A
Application number: US595296A
Authority: US
Inventors: Walter J Zenner
Original assignee: Teletype Corp
Current assignee: AT&T Teletype Corp
Priority date: 1945-05-23
Filing date: 1945-05-23
Publication date: 1968-07-23
Anticipated expiration: 1985-07-23

Description

W. J. ZENNER July 23, 1968 KEYBOARD OPERATED SPRING POWERED TYPE WHEEL RECORDER Filed May 23, 1945 3 Sheets-Sheet 1 INVENTOR WALTER J. ZENNER July 23, 1968 w. J. ZENNER 3,

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KEYBOARD OPERATED SPRING POWERED TYPE WHEEL RECORDER Filed May 23, 1945 3 Sheets-Sheet 3 INVENTOR WALTER J. ZENNER United States Patent 3,393,785 KEYBOARD OPERATED SPRING POWERED TYPE WHEEL RECORDER Walter J. Zenner, Des Plaines, 'lll., assignor to Teletype Corporation, Chicago, Ill., a corporation of Delaware Filed May 23, 1945, Ser. No. 595,296 Claims. (Cl. 197-12) The present invention pertains to recording apparatus and more particularly to a keyboard operated type wheel printer.

The object of the present invention is to provide a lightweight portable printing unit.

A further object of the present invention is to provide apparatus for enciphering and deciphering coded messages.

The instant apparatus comprises, in general, a keyboard unit whereby upon depression of a particular key, an electrical circuit is conditioned through a cipher unit or reciprocal maze to a segmented distributor and through the winding of a type wheel magnet. Thereafter, upon the operation of a print control bar, a shaft is released for rotation which carries on it a brush for traversing the segmented distributor, and a type wheel having a plurality of stops, each associated with a character. At such time as the brush traverses the segment which is connected in the circuit conditioned by the operation of the key, the magnet will be energized causing a stop arm to engage a stop associated with the type wheel to thereby stop the type wheel in a position .whereat the selected character will be presented to a print hammer whereupon the character will be recorded on a movable tape.

The present invention may be understood more fully by referring to the following detailed specification taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view, partly broken away, showing the apparatus embodying the invention;

FIG. 2 is a front elevational view of the assembled apparatus;

FIG. 3 is a side elevational view of the apparatus, as seen in FIG. 2 looking from the left toward the right;

FIG. 4 is a side elevational view of the apparatus shown in FIGS. 1 and 3 with certain of the parts removed in order to show more clearly certain other parts;

FIG. 5 is a diagrammatic view showing the wiring diagram and fragments of mechanical parts associated therewith;

FIG. 6 is a front view of a tape carrier provided with tape storage means;

FIG. 7 is an end elevational view of the tape holder shown in FIG. 6, showing in dotted lines an operational view thereof, and

FIG. 8 is an enlarged sectional view of means for obtaining a positive securement of the key top with respect to the key lever.

Referring now to FIG. 2, the apparatus according to the present invention comprises a carrying case or frame 11 in the front of which is secured a plate 12 by means of screws 13. The plate 12 is provided with a plurality of slots 14 therein, through which extend a plurality of key levers 16, said plate and slots serving to correctly align the key levers. Each of the key levers 16 is provided with a key top 17 secured thereon. A print control bar 18 is secured across the front of the device by a pair of levers 19 which extend through two long vertical slots 21 in the plate 12 and frame 11.

Also shown in FIG. 2 is a counter 22 and a general view of the recording apparatus, which will be described more fully hereinafter.

Referring now to FIG. 1, it may be seen that each of the key levers 16 protrudes forwardly from a key controled member indicated generally by the numeral 23, which is formed of a plate 24 having a slot 26 extending centrally thereof, approximately in the upper half of the plate. The plate 24 has a lug 27 extending from the forward edge thereof, toward the bottom, and a lug 28 ex tending from the rearward edge thereof toward the back. The plate 24 is further provided at the back with a rearwardly and downwardly extending portion 29 near the base of the plate, a ing 31 also on the rearward edge and positioned below the member 29, and an outwardly and rearwardly extending portion 32 at the bottom thereof. A spring 33 is secured to each plate 24 directly below the central slot 26 and extends upwardly within the slot and is secured at the opposite end thereof to a member 34 which extends across the entire front of the apparatus, passing through a similar slot 26 in each of the key members, and which is secured'at the ends to the frame. Through the action of the springs 33, the members 23 are normally biased to their upward position.

Associated with each of the rearwardly extending lugs 28 is an electrical contact pile-up which is formed of a movable swinger 36 normally in engagement with a rearward contact 37 and adjacent to a forward contact 38. The swinger 36 is so made that through engagement with the lug 28, during a normal or unoperated position of the apparatus when each key member is in its upward position, the swinger 36 will be in engagement with the rearward contact point 37. However, in the event that one of the key members is selected and depressed against the action of its spring 33, the lug 28 will be removed from engagement with the swinger-36, and through the inherent resiliency of the swinger, will allow it to be positioned in engagement with the forward contact point 38, instead of with the rearward contact point 37. It might be noted that either the lug 28 or the section of the swinger 36 whch comes in engagement with the lug 28, should be made of an insulating material so that no electrical circuit will be completed to the key members.

A bar 39 extends across the entire front of the apparatus and is positioned below the lug 27 extending forwardly from each of the key members 23 in such a manner that upon depression of any of the key members, the bar 39 will limit the downward movement thereof by engaging the lug 27 and preventing further downward movement. The bar 39 is secured by any suitable means to the inside of the front plate 12.

Positioned slightly to the rear and below the key memhers is a bail 40 which is pivoted at pivot points 41 to members 42 extending from the frame of the apparatus and which is normally biased in a counterclockwise direction by means of springs 43 at each end thereof (FIG. 4). The bail 40 extends upwardly and has near the upper surface thereof, a forwardly extending lip 44 which is adjacent to the

portions

29, 31, and 32, all of which extend rearwardly from the key members 23. The cooperation of the bail with various of these protuberances will be explained hereinafter in the description of the operation of the apparatus. The bail 40 is formed at the lefthand side thereof (FIG. 1) with a sidewardly extending arm 46 which is secured to the bail 40 by means of screws 47. The opposite or right-hand side of the bail 49 is formed with an upwardly extending arm 48 which has a short forward extension at the top thereof.

As previously mentioned, with respect to the discussion of FIG. 2, a print control bar 18 is provided which extends across the front of the apparatus and is secured within the apparatus by means of levers 19 at each end thereof. The levers 19 are pivoted at 49 to two members extending upwardly from the apparatus frame and are provided with a bar 52 which extends across and is connected to each of the levers 19 near the pivot point thereof. A plate 53 extends from the bar 52 near the righthand end thereof which has a spring 54 connected thereto which tends normally to bias the levers 19 and print bar 18 in a counterclockwise or upward direction. The righthand lever 19 is provided with a forwardly extending arm 56 which has a sidewardly extending lug 57 at the forward end thereof which overlies the sidewardly extending portion of the arm 48 extending upwardly from the bail 40 and associates therewith under certain operating conditions.

A lever 58 is mounted pivotally at 59 to the left lever 19 associated with the print control bar 18 at an intermediate point thereof and is biased normally in a counterclockwise direction by means of a spring 61. The lever 58 is formed near the upper end thereof with a lug 62 extending rearwardly and with a sidewardly extending pin 63.

Positioned immediately below the lug 62 of lever 58 is one arm 64 of a U-shaped member 66 which is mounted pivotally on a shaft 67 and which is formed with a rearwardly extending rightward side 68 which is formed at the rearward extremity thereof with an upwardly extending arm 69 and a downwardly extending arm 71. The rightward side 68 of the U-shaped member 66 is formed with a sidewardly extending pin 72 secured therein. The opposite or leftward side of the U-shaped member 65 has a lug 73 extending rearwardly thereof and an arm 74 extending upwardly near the front thereof.

A pawl 75 is mounted pivotally at 76 to the rearward extremity of the side 68 of the U-shaped member 66 and has a rearwardly and downwardly extending arm 77 at the back thereof which is connected by means of a spring 78 to the downwardly extending arm 71, previously mentioned.

The U-shaped member 66 has a lug 79 extending downwardly therefrom at a point approximately centrally located with respect to the sides thereof which has a spring 81 connected thereto, said spring extending therefrom forwardly in the apparatus. The forward end of the spring 81 is connected to a member 82 extending from the frame of the apparatus, as may be seen by referring to FIG. 3.

A contact pair 83 is so positioned in the apparatus as to overlay the operating position of the pin 72 extending sidewardly from the rightward side 68 of the U-shaped member 66 in such a manner that it is normally closed but upon operation of the pin 72, the contact pair 83 will be opened in a manner which will be described hereinafter.

A stationary camming member 84 is secured in the frame of the apparatus in a manner not shown and is so positioned that it underlies the pin 63 extending sidewardly from the upper extremity of the lever 58. The utility of the member 84 is to engage the pin 63 as the lever 58 moves downwardly and cam the lever 58 in a clockwise direction, against the urging of its spring 61, in a manner which will be described hereinafter in the operation of the apparatus.

A magnet 86 is provided which is formed of a pair of windings and which is fastened securely to the apparatus frame. The magnet 86 is used, when energized, to control the type wheel operation for recording purposes in a manner to be described later. Adjacent the pole pieces of the magnet 86 is an armature 87 which is formed of an arm of a member 88 which is mounted pivotally on the shaft 67 to the left of the U-shaped member 66. The member 88 is formed, as just mentioned, of an arm serving as the armature 87 of the magnet 86 and also with a forwardly and downwardly extending arm 89 which has a sidewardly extending lug 91 at the foremost extremity. A spring 92 has one end thereof connected to the lug portion 91 and tends to bias the member 88 in a counterclockwise direction about the shaft 67, with the armature 87 integral therewith away from the magnet 86. The opposite end of the spring 92 is secured to the frame of the apparatus. By referring to FIG. 4, it may be seen that the member 88 has a downwardly extending arm 93 which is provided, at the extremity thereof, with a central slot 94 which is utilized for a purpose to be later described.

Referring back again to FIG. 1 it may be seen that a ratchet wheel 96 having a plurality of teeth in the outer periphery thereof is positioned immediately below the hooked end of the pawl in such a manner that the pawl may engage the ratchet. The ratchet 96 is rotatably mounted on the shaft 67 and is connected by a sleeve (not shown) to a gear 97 which is of a larger diameter than the ratchet 96 and is also rotatably mounted on the shaft. A pinion 98 is provided in meshing engagement with the gear 97 and is fastened securely to a shaft 99. Thus, it may be seen that in the event that motion is imparted to the ratchet 96 by the pawl 75, motion will likewise be imparted to the gear 97, the pinion 98 in meshing engagement therewith, and to the shaft 99 which is rotatably mounted in bearing blocks 101 (only one of which is shown) which are secured to the frame of the apparatus. A gear 102 is also fastened securely to the shaft 99 so as to rotate therewith and is in meshing engagement with a pinion 103 secured to a stub shaft 104, which is secured rotatably in the apparatus frame. The opposite end of stub shaft 104 is connected to a governor 106 which is of the type used in dial telephones, for instance, and which regulates the speed of rotation of the stub shaft 104 and of the pinion 103 secured thereto.

Also secured to the leftward extremity of shaft 99 is a type wheel indicated generally by the numeral 107 which is formed with a plurality of type pallets 108 thereon, and which is also provided with identifying characters 109 thereon, which through cooperation with an indicating lever 111 indicate visually the character which has been selected. The type wheel has an index wheel 112 secured thereto which has a plurality of notches in the periphery thereof, each of said notches corresponding to a type pallet 108. The type wheel 107 is so positioned in the apparatus that the index wheel 112 underlies the lug 91 extending from the arm 89 of the member 88 so that when member 88 is biased in a clockwise direction, the lug 91 will enter a notch in the index wheel 112.

To the opposite extremity of the shaft 99 is fastened securely a brush arm holder 113 which is provided with a pair of brushes 114 thereon. The brushes 114 are utilized when the shaft 99 and the brush arm holder 113 are rotating to traverse successively and bridge a plurality of segments of a segmented ring 116 with a solid ring 117, which are part of a stationary commutator indicated generally by the numeral 118.

A U-shaped member 121 is mounted pivotally on a shaft 122 to the left of the lever 19 and lever 58, previously described. The U-shaped member 121 is formed with a short forwardly extending arm 123 at the left side thereof, and at the right side with a rearwardly extending lever 124 and a rearwardly extending lug 126. The lug 126 has a spring secured thereto which tends normally to bias the U-shaped member 121 and the arms associated therewith in a clockwise direction. Referring now to FIG. 4, it may be seen that the arm 124 of the U-shaped member 121 is provided with a pin 127 extending sidewardly therefrom and a sidewardly extending plate 128 which has a set screw 129 adjustably positioned therein. A spring 131 has one end thereof secured to the sidewardly extending plate 128. Also mounted pivotally on the shaft 122 is a second U-shaped memher 132 (FIG. 1) which has a single rearwardly extending arm 133 which has positioned near the rearward extremity thereof, a block 134. The opposite end of the spring 131, previously mentioned, is secured to an off-set section of the arm 133 in such a manner that the block 134 is held in engagement with the end of the set screw 129. Secured to the block 134 is a print hammer 135.

Referring again to FIG. 1, it may be seen that the upwardly extending arm 74 of the U-shaped member 66, mounted pivotally about the shaft 67, has a plate 137 mounted adjustably thereon at 138. A lever 139 is pivotally mounted at one extremity to the plate 137 and extends downwardly in an arcuate curve in such a manner that its opposite bifurcated extremity 142 is positioned over the pin 127, extending sidewardly from the arm 124 (FIG. 4).

The left-hand lever 19 of the print control bar 18 extends rearwardly from its pivot 49, as may be seen in FIG. 4, and is provided with a pin 143 near the rearward extremity thereof. A lever 144, which is pivotally mounted at 146, is provided at the forward extremity thereof with a slot 147 which engages the pin 143 extending from the lever 19. The lever 144 supports a pawl 148, pivotally mounted toward the rear thereof at 149, which extends upwardly from the lever. A second pawl 151 is pivotally mounted at 152 to the lever 144 in such a position that its pivot point 152 is twice the distance from the lever pivot point 146 as is the pivot point 149 of the pawl 148. A spring 153 is provided which is secured at opposite ends to the

pawls

148 and 151 and which tends to bias them in a clockwise and counterclockwise direction, respectively, toward each other.

A pair of

ratchets

154 and 155 are securely mounted to a shaft 157, and are so positioned that the pawl 148 cooperates with the ratchet 154 whereas the pawl 151 cooperates with the ratchet 155. The ratchet 154 is provided with a plurality of teeth thereon whereas the ratchet 155 is provided with four teeth only. The difference of the number of teeth on the ratchets and the operation of the two

pawls

148 and 151 in conjunction therewith, will be described hereinafter in the description of the operation of the apparatus.

Still referring to FIG. 4, it is to be remembered that the downwardly extending arm 93 of the member 88 was described as having a centrally located slot 94 at the lower extremity thereof. Cooperating with such slot is the head 158 of a lever 159 which is pivotally supported on a shaft 161. The lever 159 has a portion 162 extending rearwardly thereof to which is secured one end of a spring 163 which tends normally to bias the lever 159 1n a clockwise direction. The lever 159 is formed on its forward edge with an arcuate portion 164, toward the top, which has a cutaway portion immediately therebelow forming a shoulder 165. The lever 159 is so positioned that the extremity of the lever 124 normally rides agalnst the arcuate portion 164 of the lever 159.

A manually operable lever 167 is provided which extends toward the right, as viewed in FIG. 4, through a slot (FIG. 2) in the carrying case 11 of the apparatus. The lever 167, as seen in FIG. 4, is formed at the rearward extremity thereof of a U-shaped member which is pivotally mounted on a shaft 169. One side of the I J-shaped member has an upwardly extending arm 17 0 which has a sidewardly extending lug at the top thereof and 1s so positioned as to normally be in engagement with the rear edge of the pawl 151. When the rightward end of lever 167 is in its upward position, the upwardly extending arm 170 thereof permits the pawl 151, under the urging of Its spring 153 to be positioned in a counterclockwise direction in engagement with ratchet wheel 155. In the event, however, that lever 167 were to be operated manually to its clockwise position the upwardly extending arm 170 thereof would engage the pawl 151 and urge it in a clockwise direction whereat it would be out of engagement with its associated ratchet 155. The opposite side of the U- shaped member, formed at the extremity of the lever 167, has an arm 172 formed thereon which has at its extremity a sidewardly extending lug 173 made of an insulating material. As may be seen by referring to FIG. 3, the insulated lug 173 overlies a swinger arm 174 which forms the central contact between an upper contact point 175 and a lower contact point 176 of a contact pile-up which is secured to the side frame of the apparatus. During such time as the lever 167 is in its upward or counterclockwise position, as viewed in FIG. 4, the arm 172 will likewise be in its extreme counterclockwise position, and referring to FIG. 3, the sidewardly extending lug 173 will not be in engagement with the swinger 174. Under this condition, because of the inherent resiliency of the swinger 174, it will be in electrical engagement with the upper contact point 175. However, in the event that the lever 167 is moved downwardly to its extreme clockwise position, the arm 172 will be urged about shaft 169 to its clockwise position at which time it will engage the swinger 174 and position it in engagement with contact point 176, thereby removing it from engagement with contact point 175 and breaking the electrical circuit which had previously been estabilshed therethrough, as will be described later.

Referring again to FIG. 1, it may be seen that the rearward extremity of an arm 178 of a U-shaped member 179, pivotally mounted on shaft 180, is so positioned that it underlies the forwardly extending lug 123, forming one side of the U-shaped member 121 which is mounted pivotally on the shaft 122. A spring 181 is secured to the arm 178 and tends normally to bias the arm 178 and U- shaped member 179 in a clockwise direction about the pivot shaft 180. The opposite side of the U-shaped member 179 has a downwardly extending arm 182 integral therewith, which is formed at the lower extremity thereof with an upper step or shoulder 183 and a lower step or shoulder 184. The same side of the U-shaped member 179 also has an unwardly extending arm 186 formed integral therewith which has a roller 187 at the upper extremity thereof. Associated with the roller 187 is the movable swinger of a contact pair 188.

A second U-shaped member 191 is also pivotally mounted on the shaft and is formed, as may be seen in FIG. 4, with an upwardly and forwardly extending lever 192. The forwardly extending arm of lever 192 passes through an opening in the front of the frame 11 and is thus in position for manual operation. The U- shaped member 191 is also formed with a downwardly extending arm 193 which is formed at the bottom thereof with a rearwardly extending lug 194. A third arm 196 extends rearwardly from the U-shaped member 191 and has a sidewardly extending lug 197 at the rearward extremity thereof. The arm 196 and sidewardly extending lug 197 are so positioned that the lug 197 underlies the lever 124, previously mentioned. A spring 198 is secured at one end to the arm 196 and normally tends to bias that arm and the U-shaped member 191 formed with the

arms

192 and 193 in a clockwise direction.

It is to be noted that the various parts of the apparatus are so positioned that the end of the sidewardly extending arm 46 of the bail 40 is normally in association with the extremities of the

arms

182 and 193, as exemplified by the

shoulders

183 and 184 and the lug 194. The various associations and operation of these parts will be hereinafter described.

By referring to FIG. 3, it may be seen that a drive roll 201 is secured to the opposite end of shaft 157, which is under the control of

ratchets

154 and 155. Associated with the drive roll 201 is a friction roll 202 which is mounted rotatably at the extremity of one arm of a U-shaped member 203, which is normally biased in a clockwise direction toward the drive roll 201 by means of a spring 204. Passing between the drive roll 201 and the friction roll 202 is a tape 206 upon which characters are printed. The tape 206 is stored in a tape storage device indicated generally by the numeral 207 and passes over a guide pin 208 and through a guide 209 before it is threaded between the drive roll 201 and the friction roll 202. Thereafter, the tape 206 is fed through a tape guide 210 so as to be passed through the apparatus in such a manner that it passes under the type pallets 108 and above the print hammer 135. Thereafter, the tape 206 passes through an extension of the tape guide 210 until it issues from the front of the apparatus.

Still referring to FIG. 3, it may be seen that an inked ribbon 212 is spooled at either end thereof on a ribbon spool 213. The ribbon 212 is supported and directed by means of a guide 214 so that it will pass between the tape 206 and the type pallets 168 on the type wheel 107.

By referring to FIG. 1, it may be seen that the sidewardly extending extremity of a lever 216, which is pivotally mounted on a shaft 217, extends immediately above the rearwardly extending lug 73 of the leftward side of the U-shaped member 66. The lever 216, which is normally biased in a clockwise direction by means of a spring 218, controls the operation of a ribbon stepping device indicated generally by the numeral 219. Inasmuch as the ribbon stepping mechanism does not form part of the present invention, it is not deemed necessary to explain its operation, other than to say that upon the operation of the U-shaped member 66 its lug 73 will be moved upwardly and downwardly and through cooperation of the corresponding movement of the arm 216 and the resulting operation of the ribbon stepping mechanism 219, the ratchet wheel 220 will be stepped during each operation of the device. Thus, inasmuch as one of the spools 213 is associated operatively with the ratchet 220', through the shaft 217, the ribbon will be advanced in a step-by-step manner. A lever 221 is provided which allows the tape stepping mechanism to be manually placed in operative engagement with the ratchet wheel 220 or in operative engagement with a second ratchet wheel similar to 220, but not shown in the drawings, which would operatively control the operation of the second ribbon spool 213. Accordingly, through the operation of these units, the

ribbon will be stepped forwardly until it is almost completely unwound from one spool at which time the stepping mechanism will be reversed, as is well known in the art, so that the stepping mechanism will operate the other of the spools in order to rewind the ribbon.

Previously, with respect to a description of FIG. 2, it was indicated that a counting mechanism 22 was provided for the apparatus. By referring to FIG. 3, it may be seen that the counting mechanism 22 is operated by means of an arm 222 which is coupled operatively by means of a rod, which is not shown, to the leftward lever 19 of the print control bar 18. Every time that the lever is operated, the rod connection will cause the arm 222 to be pivoted in a counterclockwise direction which will cause the operation of the counting mechanism. In the event that it is desired to reset the counting mechanism to zero or to set it to a predetermined number, it may be done manually by means of the hand wheel 223, shown in FIG. 2.

By referring to FIGS. 6 and 7, the tape storage apparatus, previously indicated generally by the numeral 207, may be seen. By referring to FIG. 7, it may be seen that the unit comprises a lid 225 which is pivotally mounted at 226 and which, by means of spring 227, is normally urged in a clockwise direction. The plate 225 is provided with a hub 228 located centrally thereof by means of which a spool of tape 229 may be held in position. A holddown clamp 230 is secured to the plate 225, toward the outer extremity thereof, and is formed with an off-set portion in such a manner that once the spool of tape 229 is placed on the hub 228 the hold-down lever may be positioned to hold it in place. It is to be noted that the spool of tape 229 is not the one which is being fed through the apparatus but instead is an extra roll which may be provided for use when the one currently being used is exhausted.

A second plate 232 is provided which is pivotally mounted toward the lower extremity thereof on shaft 233, which is fastened securely to the base of the apparatus. Plate 232 has at the upper extremity the plate 225 pivotally mounted thereto at 226, as previously described. The plate 232 likewise has a hub 234 located centrally thereof on which is positioned a roll of tape 235 from which the tape 206 is drawn, which is threaded through the apparatus. The tape holder 207 is so pivoted that at such time as the roll 235 is completely used, the plate 225 may be pivoted upwardly in a counterclockwise direction after the spool 229 has been taken off and this spool may then be inserted on the hub 234 associated with plate 232. The plate 225 will then be allowed to pivot downwardly through the action of its associated spring 227, which has its opposite end secured to the plate 232, in such a manner that the plate 225 serves as the necessary means to hold tape roll 235 in place. Thereafter, the end of tape roll 235 is threaded through a pair of tape guides 236, as may be seen in FIG. 6, and passed through the apparatus.

By referring to FIG. 8, it may be seen that the extremity of the key lever 16 upon which the key button 17 is secured has an upwardly extending portion which is composed of two separate portions 238 separated by a notch or slot 239. By utilizing such a construction, when the key top 17 is forced over the upwardly extending portions 238 of the key lever 16 the portions 238 will tend to move toward each other, because of the slot 239 separating them and at such time as the key top 17 is positioned whereat its base is in engagement with a shoulder 240 On the key lever 16, the portions 238 will, through their .inherent resilience, tend to move outwardly and thus hold the key top 17 securely in position.

By referring now to FIG. 5, it may be seen that the contact swinger arms 38, with the exception of the lowermost one shown, are connected by means of individual conductors 242 to separate contact points on a code disc 243. The code disc 243 is the foremost disc of a plurality of code discs, which are shown diagrammatically in FIG. 1, and which form a cipher unit or reciprocal maze, which is well known to those versed in the cryptographic art. The lowermost swinger arm 36 is connected by means of a conductor 244 to the contact point 37 of the contact pair shown immediately above it. The reason and utility for such wiring of the bottom two contacts will be described hereinafter. The other contact point 38 of the contact pile-up associated with each key lever is connected by means of a common conductor 245 to one side of the contact pair 188 which, as previously mentioned, was under the control of a roller 187 forming the extremity of lever 186. The opposite side of the contact pair 188 is connected by means of a conductor 246 to the movable side of the contact pair 83, previously described. The opposite side of the contact pair 83 is connected over a conductor 248 to the winding of the magnet 86 and thence to grounded battery 249. The contact point 37 of the contact pile-up associated with each key lever is connected by means of a conductor 250 to one of the individual segments of the segmented ring 116 of the commutator 118. However, the lowermost contact point 37 shown is connected by means of conductor 252 to the swinger arm 174, previously mentioned. It is to be noted that the solid commutator ring 117 is connected to ground over conductor 251.

Operation In describing the operation of the apparatus a complete cycle of operation will be described which includes the apparatus with none of the key levers depressed upon the operation of a key lever, upon the operation of the print control bar, the resulting printing of a character, and the return to normal conditions in the event that such condition differs from the normal condition initially described. Further, the instant description will be made with the manually operable lever 167 in its upper or enciphering position, and a separate description .will be made of the operation of the apparatus when the lever 167 is in its downward or deciphering position wherein it differs from that previously described.

By referring to FIG. I, it may be seen that when the key levers 16 and their associated members 23 are in their upward or unoperated position, the lug 28 extending therefrom cams the electrical swinger 36 against the contact point 37 of the associated contact pile-up. However, by referring to FIG. 5, it may be seen that no electrical circuit is established at this time inasmuch as none of the swingers 36 are in engagement with their associated contact points 38 to complete a circuit through the common conductor 245 to battery 249. Further, inasmuch as contact pair 188 is opened, as will be later described, no electrical circuit is established. Likewise, during the normal or unoperated position of the key levers, as may be seen by referring again to FIG. 1, the bail 40 is biased in a counterclockwise direction under the urging of its associated springs 43. When the bail 40 is in this position, the arm 48, extending upwardly therefrom with the lug at the upper extremity thereof will be so positioned as to underly the sidewardly extending lug 57 of the arm 56 associated with the right-hand lever 19 of the print control bar 18, thereby blocking any operation of the print control bar 18. In other words, under this condition it will be impossible to operate print control bar 18 in a downward direction to cause opera tion of the apparatus. The arm 46 extending sidewardly from the bail 40 will be positioned in its extreme counterclockwise position and will engage the lowermost step 184 of the steps formed at the bottom of the lever 182. This step acts as a stop to limit the counterclockwise motion of the bail 40.

Inasmuch as the print control bar 18 will be held in its upward or unoperated position through the bo:king thereof by means of the lever 48, and also through the urging of its associated springs 54, the levers 19 will also be in their upward position as will be the lever 58 which is pivoted at 59 to the leftward lever 19. Under this condition, the lug 62 formed at the upper extremity of the lever 58, and which normally overlies the end of lever 64 extending from the U-shaped member 66, will merely rest thereon and will allow the U-shaped member 66 to be held in its extreme counterclockwise position under the urging of the spring 81. During this condition, the pin 72 extending outwardly from the side 68 of the U-shaped member 66 will be out of engagement with the movable swinger of the contact pair 83, and because of the inherent resilience thereof, the contact pair 83 will be closed. Such condition may be seen by referring to FIG. 5, but inasmuch as this contact pair is in the circuit from the battery 249 to the contact points 38, which was previously described as being open, and since none of the movable swingers 36 are in engagement with the contact points 38 and as contact pair 188 is open at this time, no electrical circuit will be established.

Inasmuch as the U-shaped member 66 is in its extreme counterclockwise position, the lever 139, which is connected to .plate 137 mounted to arm 74 at 138, is held in its upward position so that the bifurcated portion 142 at the extremity thereof is not applying any pressure to the pin 127 extending sidewardly from the lever 124. In this condition, the lever 124 will be in its extreme clockwise position, as seen in FIG. 4, under the urging of the spring 125 connected to the lug 126 integral with the lever and U-shapcd member 121. During this condition the arm 133 of the U-shaped member 132 will also be held in its extreme clockwise position through the action of the set screw 129 extending from the sidewardly extending section 128 of the lever 124 which exerts pressure directly on the print block 134 integral with the arm 133. In the extreme clockwise position of the arm 133, the print hammer 135, at the extremity thereof, will be positioned against the tape 206. It is to be noted that when the lever 124 is in its extreme clockwise position, the forwardly extending lug 123 integral therewith exerts pressure on the rearwardly extending lug 178 of the U-shaped member 179 and thereby holds the U-shaped member 179, against the urging of its spring 181, in its extreme counterclockwise position. In such position the downwardly extending arm 182 thereof will be, as previously mentioned, presenting its step or shoulder 184 to the extremity of lever 10 46, which serves as a stop for the counterclockwise rotation of the bail 40.

Also, under this condition of operation the magnet 86 will be in its deenergized condition inasmuch as the magnet is in the electrical circuit between the battery 249, the open contact pair 188, and the open contacts at contact points 38, as previously mentioned. Thus, it may be seen no electrical circuit may be established at this time for the magnet 86. During the deenergized condition of the magnet 86 the armature 87 will not be attracted thereto and, therefore, the plate 88 and arm 89 will be urged in counterclockwise direction about shaft 67 by the spring 92. As previously mentioned, the lever 124 was in its extreme clockwise position and at this time presents its extremity to the arcuate surface 164 of the lever 159, pivoted about shaft 161 by the spring 163. In this condition, the clockwise rotation of the lever 159 due to the urging of its spring 163 will be limited through the engagement of the extremity of lever 124 and the arcuate surface 164, as previously mentioned. Inasmuch as the head 158 of the lever 159 extends within the slot 94 in the lower portion of the arm 93 extending downwardly from the member 88, the counterclockwise movement of the member 88 and the arm 89 associated therewith will be limited to the extent of the amount of clearance in the slot 94. Thus, while the spring 92 urges the lever 89 and member 88 in a counterclockwise direction, these members may only move to such an extent that the left-hand side of the slot, as seen in FIG. 4, comes into engagement with the head 158 of the lever 159. Due to the adjustment of the various members and the size of the slot 94, with respect to the head 158, the member 88 and the arm 89 may only move in a clockwise direction to an extent wherein the sidewardly extending lug 91 is in engagement with the notches in the periphery of the index wheel 112 to a predetermined amount, which is not as far as the lug 91 could otherwise go if it were biased to its extreme clockwise position. During the entrance of the lug 91 within one of the notches in the periphery of the index wheel 112, the type wheel 107, the shaft 99, the gear 102 and pinion 98 on the shaft 99, and the brush arm 113, also on the shaft, will be held stationary against rotation. Inasmuch as the notches in the index wheel 112 are wider toward the outer periphery than at the inner point thereof, it is not necessary that the lug 91 enter all the way within the notch to hold the index wheel and type wheel against rotation. However, during a printing operation, at which time it is necessary that the type wheel be properly aligned with a type pallet 108 in proper presentation to the type hammer 135, it becomes necessary that the lug 91 enter fully in a notch in the index wheel 112. It is for these reasons that the lug 91 may enter the notches in the type wheel in two varying degrees. The description with respect to the lug 91 entering a notch completely will be described hereinafter under the description of the operated position of the apparatus.

Inasmuch as the levers 19 are in their upward or unoperated positions, the pin 143 at the lowermost extremity of the left-hand lever, which as previously mentioned, enters a slot 147 in the lever 144, holds lever 144 in its extreme clockwise position, as may be seen in FIG. 4. Under this condition the

pawls

148 and 151 are in engagement with the

ratchets

154 and 155, respectively, but do not exert any pressure thereon to cause rotation to be imparted to either of the ratchets.

Also, under the unoperated condition of the apparatus the gear 97, which is connected by means of a sleeve (not shown) to the ratchet 96, will be in a stationary position not only through the locking of the shaft 99 and the pinion 98 thereon and through the meshing engagement of pinion 98 with gear 97, but also because the U-shaped member 66 is in its extreme counterclockwise position and has no stored energy to impart thereto. The imparting of motion to the ratchet 96 and the gear 97, through the 11 operation of the U-shaped member 66, will be described hereinafter.

As previously mentioned, the extremity of arm 46 extending from the bail 40 is positioned on step 184 of the lever 182. Because of this engagement the arm 193 extending from U-shaped member 191 is prevented from moving in a clockwise direction under the urging of its spring 198 further than to such a point that the lug 194 at the lowermost extremity thereof engages the side of the arm 46, as may be seen in FIG. 4. It is to be noted that in this position there is a clearance between the sidewardly extending lug 197 of the arm 196 of U-shaped member 191 and the bottom of the lever 124 which it underlies.

The above description has indicated the condition of the apparatus when it is in its unoperated position with none of the key levers selected. Hereinafter the condition will be described wherein one of the key levers is selected with the resulting depression thereof. It is to be remembered at this time that the apparatus is now being described with the manually operable lever 167 in its counterclockwise or encipher position, at which time the insulated lug 173 is not in engagement with the movable swinger 174 of the associated contact pile-up, thereby allowing the movable contact arm to be in engagement with its associated upper contact point 175.

Upon the selection and operation of one of the key levers, such as the A key lever shown in FIG. 1, the member 23 will move downwardly against the tension of its spring 33 an amount which will be limited by the lug 27 extending forwardly from the plate engaging the stop 39. As the member 23 moves downwardly, its rearwardly and downwardly extending lug 29 will engage the back of the bail 40, as shown in FIG. 1, and because of the angular contour of the lug 29 will cause the bail 49 to be rotated in a clockwise direction about pivot points 41 against the urging of the associated springs 43. Because of the forwardly extending lip 44 at the top of the bail 40, the key member 23 will not be able to move upwardly, inasmuch as the rearwardly extending lug 31 will be below the lip 44 of the bail 40 and thus prevent the lever from moving upwardly. At such time as the bail 40 is cammed in a clockwise direction, the lip 44 will engage the steps formed between the rearwardly extending lugs 31 and 32 of all the unselected key levers, which are in their extreme upward position under the urging of their associated springs 33, and thus preclude either upward or downward movement of the unselected members 23.

When the bail 40 moves to its extreme clockwise position, the arm 46 extending leftwardly therefrom will move from its normal position with its extremity in engagement with the step 184 of the lever 182 and will assume a position on the step 194 of the lever 193. The lever 193 will thus no longer be blocked in normal position by the extremity of arm 46 but will be allowed to move such a distance, as mentioned above, under the urging of its spring 198. At the same time, the upwardly extending arm 48 of the bail 40 will also move in a clockwise direction, thereby removing its extending lug from blocking engagement with the sidewardly extending lug 57 of the arm 56. Therefore, the print control bar .18

is no longer blocked from operation by means of the arm 48, but at this time remains in its extreme counterclockwise position under the urging of its spring 54.

As key plate 24 is moved downwardly, the lug 28 extending rearwardly therefrom no longer will be in engagement with the movable swingfier 36 of the contact pile-up asociated therewith, and due to the inherent resilience of the contact swinger it will move to its forward position whereat it will be in engagement with contact point 38 rather than in engagement with contact point 37. The result of the swinger 36 moving, as just described, will be referred to under a later description of the circuit as shown in FIG. 5.

The actual depression of a key lever 16 and the resulting movement to its key plate 24 affects only the elements which have been described above. However, it is to be noted that the key plates are automatically locked after the operation of one of the keys through the movement of the bail, so that no other key can be selected as long as one of the keys remains in its selected position.

Now, proceeding with the description of the apparatus, after a key has been selected and depressed it is necessary to manually depress the print control bar 18 in a downward or clockwise direction, as seen in FIG. 1, in order to cause further operation of the apparatus. As a result of the clockwise movement of the print control bar 18, the associated levers 19 will move in a similar direction and the lever 58 pivoted at 59 to the left-hand lever 19 will be caused to move downwardly. As a result of such downward movement of the lever 58 the lug 62 which extends rearwardly from its extremity will engage the extremity of arm 64 and cause this arm to be moved or pivoted in a clockwise direction. Inasmuch as the arm 64 is a part of the U-shaped member 66, the U-shaped member will likewise be pivoted in a clockwise direction about pivot shaft 67, which will, among other things, result in a stretching of the spring 81 secured thereto by means of the lug '79. The spring 81 must necessarily be strong and extended a predetermined amount to insure suflicient rotation of the type wheel inasmuch as it is this spring which causes operation of the apparatus through its stored energy, as will presently appear.

As the Ushaped member 66 is pivoted in a clockwise direction, its side member 68 will move likewise, and the pawl 75, which is in engagement with the teeth of the ratchet 96, will move toward the front, passing over the ratchet teeth but being held in engagement therewith under the urging of its spring 78 which tends to at all times hold the pawl in a clockwise position. As the side member moves in a clockwise direction, the pin 72 extending sidewardly therefrom will move in an upward direction to a point whereat it will engage the movable swinger of the contact pair 83 and thereby disengage it from the associated stationary contact point. By referring to FIG. 5, it may be seen that upon the opening of the contact pair 83 no circuit could possibly be established for the energizing of the magnet 86 as long as such contact pair is open.

A further result of the clockwise movement of the U-shaped member 66 results in a downward pressure being applied through the upwardly extending arm 74 and the pivotally mounted plate 137 to the arcuately shaped lever 139, which extends downwardly and engages the pin 127 extending sidewardly from the lever 124 through the bifurcated extremity 142. As the lever .139 moves downwardly, as may be seen in FIG. 4, pressure will be applied through the bifurcated end 142 thereof to the pin 127 resulting in the lever 124 being moved in a counterclockwise direction about its pivot shaft 122. As a result of a downward movement of the lever 124, the extremity thereof wil move downwardly along the arcuate surface 164 of the lever 1S9, pivotally mounted at 161, and will eventually move oil? of the arcuate surface and into the slotted portion which is below the shoulder 165. The lever 159 will, therefore, be able to move, under the urging of its spring 163, a limited distance in a clockwise direction which will be the difference between the radius of the arcuate surface .164 and of the slotted surface below the shoulder 165. As a result of such movmeent of lever 159, the head 158 thereof moves a similar amount and inasmuch it is in engagement with the member 88 through its entering the slot 94 in the downwardly extending arm 93, the member 88 may move in a counterclockwise direction, under the urging of its associated spring 92. As a result of such movement of the arm 89 of member 88, the lug 91 at the extremity thereof will be moved from latching engagement with the notches in the periphery of index wheel 112 associated with the type wheel 107. However, the type wheel 107 will not be rotated at this time inasmuch as the lug 62 of the lever 58 is in engagement with the arm 64 and is holding the U-shaped member 66 in its clockwise position. Likewise, it should be noted at this time that the removal of the lug 91 from the notches in the index wheel 112 occurs near the end of the cycle of setting of the apparatus; that is, approximately at the time that the lever 139 reaches its extreme downward position.

As the arm 124 moves downwardly to its set position, the print lever 133 and the associated print block 134 and print hammer 135 are also moved downwardly through the connection to lever 124 by means of the spring 131.

When the arm 124 moves in a counterclockwise direction, as may be seen in FIG. 4, as it approaches the limit of its travel it engages the sidewardly extending lug 197 of the arm 196, forming one of the arms of the U-shaped member 191. Further downward motion of the arm 124 causes arm 196 of the U-shaped member 191 tobe moved in a counterclockwise direction against the urging of the spring 198. As the arm 196 moves in such a manner, the downwardly extending arm 193, formed integral with the U-shaped member 191, likewise moves in a counterclockwise direction and the step or shoulder 194 thereof is removed from its position underlying the extremity of the arm 46 of the bail 40.

Likewise, as the arm 124 moves in a downward or counterclockwise direction, as seen in FIG. 1, the forwardly extending lug 123 of the U-shaped member 121 associated therewith will also move in a counterclockwise or upward direction. As a result of such movement of the lug 123, the U-shaped member 179 will be allowed to move in a clockwise direction under the urging of its spring 181, inasmuch as the underside of the lug 1 23 acts as a cam with respect to the U-shaped member 179 through engagement with the upper surface of the arm 178.

Inasmuch as the arm 193 is moved in a counterclockwise direction with its shoulder 194 no longer in engagement with the extremity of arm 46, and as arm 182 is moved in a clockwise direction, toward the extremity of lever 46, the arm 46 will engage the second step or shoulder 183 of the arm 182. Through the engagement of the arm 46 with the shoulder 183, the bail 40 will still be held in a clockwise position so that the key members are all locked as positioned. The reason for the initial engagement of the extremity of lever 46 by the shoulder 194 of the arm 193 and the later transferring of the extremity of arm 46 from that shoulder to the shoulder 183 of arm 182, is for the purpose of holding the bail and the key members in a locked position but allowing for resetting of the apparatus to a normal unoperated condition in the event that an incorrect key lever had been depressed. In the event that such had occurred; that is, manual operation of an incorrect key lever, the operator could, by applying pressure to the end of arm 192 which extends forwardly through the apparatus frame, cause such lever and the associated U-shaped member 191 to be pivoted in a counterclockwise direction, as viewed in FIG. 4. Therefore, in the event that such had occurred, the downwardly extending arm 193 would likewise move in a counterclockwise direction and the shoulder 194 would no longer be presented to the extremity of the arm 46. However, at this time, inasmuch as the print control bar 18 would not have been depressed, the arm 182 would be in its extreme counterclockwise position and the arm 46 would then be free to move back to its normal position in engagement with shoulder 184 of the arm 182. However, in this position the bail 40 would rotate back to its normal extreme counterclockwise position at which time it would not be in locking engagement with the depressed key member 23 and therefore would allow the key member to move to its upward normal position under the urging of its spring 33. However, after a key lever has been selected and the print control bar 18 depressed it is impossible to manually change the key selection through the transference of the locking of bail 40 by means of the arm 46 and, therefore, once the print control bar 18 is operated the selected character must be printed.

As the U-shaped member 79 moves in a clockwise direction, its upwardly extending arm 186 will be moved likewise and the roller 187 at the upper extremity thereof will engage the movable swinger of the contact pair 188 and cause such contact pair to be closed. By referring to FIG. 5, it is to be seen that even though the contact pair 188 is closed at this time, no circuit may be established from the battery 249 to cause the energization of the magnet 86 inasmuch as, as previously mentioned, the contact pair 83 has been opened.

With reference to FIG. 4, it may be seen that as the lever 19 is pivoted in a clockwise direction about pivot point 49, the lever 144, which is in engagement with the extremity of the lever 19 through the slot and pin connection will be moved in a counterclockwise direction about its pivot point 146. As a result of such movement the pawl 148, mounted pivotally at 149 to the lever 144, will cause rotation to be imparted to the associated ratchet 154 thereby rotating the ratchet and the shaft 157 a distance equal to the distance between adjacent teeth. In the event that one of the four teeth of the ratchet is in engagement with the upper extremity of the pawl 151 at this particular position, the pawl 151 will cause the ratchet 155 to be rotated in a counterclockwise direction an amount equal to twice the amount of the motion imparted to the ratchet 154 by the pawl 148. Such occurs inasmuch as, as was previously mentioned, the pivot point 152 of the pawl 151 is twice the distance from the pivot point 146 of the lever 144 as is the pivot point 149 of the pawl 148. The necessity under certain conditions, for imparting a double step to the shaft 157 will be described hereinafter. However, it might be noted that rotating either the

ratchet

154 or 155 with the simultaneous rotation of the shaft 157 to which they are secured, causes a corresponding movement of the tape 206 through movement of the drive roll 201, which is also fastened securely to the shaft 157.

As the print control bar 18 and the associated levers 19 approach the limit of their clockwise rotation, the lever 58, pivotally mounted to the left-hand lever 19 at 59, will reach a position whereat its sidewardly extending pin 63 will engage the upper camming surface of the stationary member 84, shown in FIG. 1. At this time the lever 58 will be rotated in a clockwise direction to such an extent that its rearwardly extending lug 62 will no longer overlie the extremity of arm 64 but will be removed from engagement therewith. Inasmuch as during the time that the arm 64 and the U-shaped member 66 have been moved in a clockwise direction the spring 81 associated therewith has been extended to store up energy, the spring 81 will cause the U-shaped member 66 to be rotated in a counterclockwise direction upon the release of arm 64. As the pawl 75, pivotally mounted at 76 to the side member 68 of the U-shaped member 66 is in engagement with a tooth on the periphery of ratchet 96 under the urging of its spring 78, as the U-shaped member 66 moves in a counterclockwise direction the pawl will cause counterclockwise motion to be imparted to the ratchet 96. Inasmuch as the gear 97 is secured to the ratchet 96 by means of a sleeve (not shown) the gear will likewise move in a counterclockwise direction and in so doing will impart clockwise rotation to the pinion 98 in meshing engagement therewith. Any clockwise motion of the pinion 98 will be imparted to the shaft 99 to which it is secured, which results in similar motion being imparted to the gear 102 and the type wheel 107 secured thereon. It is to be remembered that the lug 91 has previously been removed from blocking engagement in the notches of the index wheel 112 and, therefore, the type wheel 107 is free to move. The speed of rotation of the shaft 99 and the type wheel 107 will be controlled by the governor 106 through the meshing engagement of its associated pinion 103 with the gear 102 of shaft 99. As the shaft 99 rotates, the brush arm holder 113, secured thereto, will also rotate in a clockwise direction with the brushes 114 bridging the solid ring 117 and the individual segments of the segmented ring 116.

As the U-shaped member 66 moves in a counterclockwise direction, the pin 72 extending sidewardly from the member 68 thereof will move downwardly, which will release the movable contact arm associated with the contact pair 83, thus allowing the contact pair to close. Referring now to FIG. 5, it is to be remembered that the movable contact arm 36 associated with the A key lever, which is disclosed as the uppermost contact arm in the drawing, was previously allowed to move to a position whereat it was in engagement with its associated contact point 38. Likewise, as previously mentioned, the contact pair 188 was also closed through the clockwise movement of arm 186 and, as just described, the contact pair 83 is now closed.

In the electrical system utilized in the present invention, including the cipher unit or reciprocal maze as exemplified by the code disc 243 and which is well known in the art, the conductor 242 associated with the A key lever movable swinger 36 is connected to the A contact point of the code disc 243. An electrical circuit is set up through the various code discs forming the reciprocal maze and may result, for instance, in the A contact point coming out of the maze at the Y contact point on the code disc 243. Such being the case, an electricial circuit will be conditioned from the grounded battery 249, through the winding of magnet 86, over the conductor 248 and through the contact pair 83, now closed, over conductor 246 and through the closed contact pair 188, over the common conductor 245 to the contact point 38 associated with the A key lever, through the movable swinger 36 now in engagement therewith, through the conductor 242 to the A contact point of the code disc 243, through the cipher unit or reciprocal maze formed of the various code discs, back to the Y contact point of the code disc 243, through the conductor 242 to the movable swinger arm 36 associated with the Y key lever, through the contact point 37 to which the movable swinger is in engagement (the Y key lever has not been depressed), and through a conductor 254 to the Y segment of the segmented commutator ring 116. However, an electrical circuit will not be completed for the energization of magnet 86 until the brush arms 114 traverse the Y segment of the segmented commutator ring 116, at which time the solid ring 117 will be placed in the circuit with that particular segment and thereby supply ground through the conductor 251 for the establishment of the electri cal circuit which was traced from grounded battery 249.

Assuming that the shaft 99 has rotated to a position whereat the brush arm holder 113 will be positioned with the brush arms 114 bridging the Y segment and the solid ring 117, the above traced electrical circuit will be established causing the energization of the magnet 86. Referring to FIG. 4, at such time as the magnet 86 is energized, the armature 87 associated therewith will be attracted thereto and will cause the member 88 to be rotated about pivot shaft 67 in a clockwise direction causing the lug 91, at the end of the arm 89, to enter a notch in the index wheel 112 and thereby arrest rotation of the index wheel 112, the type wheel 107, and the shaft 99.

As the member 88 moves in a clockwise direction, its downwardly extending arm 93 will likewise be moved in a clockwise direction causing the side of the notch 94 to engage the head 158 of the lever 159 and pivot the lever 159 in a counterclockwise direction about its pivot point 161. It is to be remembered that, as previously described, the extremity of lever 124 was held in an extreme counterclockwise position by means of the shoulder 165 of the lever 159. As the lever 159 is moved, as just described, the extremity of the lever 124 will no longer be held by means of the shoulder 165 but instead the lever 124 is allowed to move in a clockwise direction along the arcuate surface 164 of the lever 159. Inasmuch as the motivating means for the lever 124 is a strong spring 125, the lever 124 will move upwardly with sufficient speed and power to cause the print control bar 133 to be moved upwardly in a clockwise direction through the engagement of the set screw 129 with the print block 134 to cause the print hammer 135 to engage the tape 206 with sufficient force to cause the selected type pallet 108 to print the selected character on the tape.

It is to be noted that the type pallets 108 are so arranged on the type wheel 107 with respect to the segments of the segmented disc 116 of the commutator 118 and with respect to the brushes 114, that at such time as the brushes bridge any particular segment the corresponding type pallet will be presented in printing position. Of course, it is necessary that the keyboard unit and the reciprocal maze be so wired that the type pallets on the type wheel correspond to the segments of the segmented ring 116.

Inasmuch as the printing of a particular character takes place at the extreme lowermost point of the type wheel, it is impossible to determine visually, other than by the particular key, the character which has been printed. Therefore, the characters have been aflixed at 109 on the type wheel 107 in a different order than the type pallets 108 appear on the type wheel so that when the type wheel is arrested in printing position the character corresponding to that which has been selected will be shown immediately adjacent the guide 111. Therefore, the operator, after depressing a key and the subsequent operation of the print control bar 18, can determine if the type wheel is so positioned with the selected character in printing position.

Immediately upon the printing arm 133 and the lever 124 moving to a clockwise or printing position, the forwardly extendin lug 123 of the U-shaped member 121 will likewise be moved in a clockwise direction, resulting in the under camming surface thereof causing the arm 178 of the U-shaped member 179 to be moved in a counterclockwise direction. At this time the arm 186, integral therewith, will likewise move in a counterclockwise direction and the roller 187 at the extremity thereof will no longer apply pressure to the movable member of the contact pair 188 to keep this pair in engagement. Therefore, the electrical circuit previously established for the energization of the magnet 86 will be broken and the magnet will be deenergized. The contact pair 188 which is closed only upon the depression of the print control bar 18 and until the printing arm 133 has been released, has been provided so that a minimum of potential may be drained from the battery 249, in order that the battery may last as long as possible. This is especially true with the instant apparatus wherein, because of its light weight and the fact that it is portable, it is desirable to utilize as small a potential source as is possible. It might be noted that the apparatus operates on two dry cells of the flashlight battery type.

In the operation of the apparatus, once a character has been printed, at which time the lug 91 is in locking position in a notch of the index wheel 112 thus precluding further rotation of the type wheel 107, the lug 91, as previously described, will not be withdrawn from such locking position until such time as the print arm 133 and lever 124 are positioned in their maximum counterclockwise position whereat the extremity of lever 124 is held locked by the shoulder of the lever 159. Inasmuch as the electrical contact pair 188 will not be c osed until the lever 124 arrives at this position, no electrical circuit can be established for the energization of magnet 86 until this time. Likewise, inasmuch as this position is not reached until the U-shaped member 66 approaches its maximum clockwise position under the manual operation of the print control bar 18, as previously described, the

17 type wheel 107 will be held against further rotation through the operation of the print control bar 18.

Because of the fact that the type wheel 107 does not return to a stop position but instead operates from the position in which it was previously stopped for the printing of a character, it is necessary to include the contact pair 83, as will now be described.

If such contact pair 83 were not in the electrical circuit and in the event that a character was selected which would establish a circuit through the segment of the segmented commutator ring 116 which was immediately adjacent to or closely adjacent to the segment establishing the circuit for the character previously printed, upon the lever 58 being cammed in a clockwise direction and releasing the U-shaped member 66 for counterclockwise motion under the urging of the operating spring 81, the magnet 86 would become energized causing the arresting of the index wheel 112 and the positioning of type pallet 108 in printing position before it would be possible for such printing to occur. This may be seen by referring to FIG. 1, wherein it is to be noted that the lever 139, which through pressure exerted by its bifurcated extremity 142 against the pin 127 (FIG. 4) sets the print arm 133, would not have returned, through its connection with the U-shaped member 66, to a sufiicient extent to allow the printing arm 133 and the print hammer 135 to cause printing. Therefore, by including the contact pair '83 in the circuit under the control of the pin 72 on the side member 68 of the U-shaped member 66 a timing is assured which will preclude a closing of the contact pair 83 and establishment of the electrical circuit for the magnet 86 until such time as the U-shaped member 66 is moved sufliciently counterclockwise to allow the lever 139 to rise sufliciently for the print arm 133 and lever 124 to rise to a sufiicient height for printing to occur. There is no danger, however, of the loss of a character by the inclusion of the contact pair 83 inasmuch as power spring 81 is sufficiently strong to cause rotation of the shaft 99 and the brush arm holder 113 to an extent that if not stopped, it will traverse the segmented ring 116 more than one complete cycle. Therefore, in the event that the brushes 114 traverse the conditioned segment of the segmented ring 116 before the electrical contact pair 83 closes for the establishment of the magnet circuit, such circuit will be established after the contact pair 83 has closed and during the second cycle of rotation of the brush arms 114 and the shaft 99.

With reference to FIG. 5, it is to be remembered that, as previously described, the contact swinger arm 36 shown lowermost in this figure was not connected to one of the contact points of the code disc 243 but instead was connected by conductor 244 to the contact point 37 of the contact pile-up, shown immediately above in the figure, which is associated with the Z character and key lever. The reason for such a provision will now be described. In the encipherin-g operation of the apparatus, it was deemed necessary to compose the message in groups of characters with a space occurring at predetermined intervals for security reasons. In the instant embodiment, means are provided, through the operation of the double space pawl 151 and associated ratchet 155 for double spacing every fifth character. Under normal operating conditions the pawl 148 will step the ratchet 154 once with each operation of the print bail so as to position the tape for the printing of the succeeding character. Therefore, by adding the second pawl 151 and the ratchet wheel 155 associated therewith, a double space may be obtained at predetermined intervals so that the tape 206 will be spaced two steps and so that when the succeeding character is printed a space equal to the size of a character will remain blank. By providing four teeth only on the ratchet 155 and twenty-four teeth on the ratchet 154, five characters will be printed on the tape after which the double space operation will occur leaving a space before the next character is printed. Thereafter,

the entire message is printed in groups of five characters with a space between successive groups. Under such predetermined grouping or spacing, there is no necessity for printing spaces at the end of words, sentences, etc., but still means must necessarily be provided so that in the deciphering of the message the person so doing may determine where to insert spaces, which obviously would not occur every five characters as in the encipherin-g operation. Accordingly, in order to achieve such results the special wiring referred to above was embodied in the invention.

In order to provide such an operation and not to make the code obvious, thus allowing deciphering by persons other than those who it is desired to be able to do so, and in order to keep the number of characters at a minimum, one of the letters of the alphabet was selected for a space designation in the enciphering process. Inasmuch as the letter Z is seldom used, it was decided to utilize this letter to designate a space.

In accordance with such provisions, as may be seen in FIG. 5, the movable contact swinger 36 associated with the Z key lever is connected o'ver conductor 242 to the Z contact point of the code disc 243. Likewise, the contact point 38, normally open, is connected to the common conductor 245 as are the other contact points 38. However, instead of connecting the contact point 37 with which the movable swinger arm 36 is normally in engagement directly to one of the segments of the segmented commutator ring 116, as are the other contact points, it is connected over conductor 244 to the movable contact arm 36 associated with a space key lever. Therefore, in the enciphering of a message, every time the operator comes to a space in the message the space key, shown as the lowermost one in FIG. 5, would be depressed, the lug 28 thereon would be moved out of engagement with the movable swinger arm 36 of the associated contact pile-up and the swinger arm would move into engagement with the front contact point 38. Assuming that the contact pairs 188 and 83 are closed, it may be seen that an electrical circuit may then be traced from the battery 249, through the contact pairs '83 and 188, over the common conductor 245 to junction point 255, through a conductor 256 to the contact point 38, through the movable swinger 36 now in engagement therewith, through the conductor 244 to the contact point 37 associated with the Z key lever, through swinger arm 36 in engagement therewith, and over conductor 242 to the Z contact point of the code disc 2-43. The circuit is then traced through the reciprocal maze in the cipherin-g unit and comes out, for instance, at the C contact point of the code disc 243. The circuit would then be traced further over conductor 242 to the movable contact arm 36 associated with the C key lever, through the contact point 37 with which the movable swinger is in engagement (C key lever not selected), and over a conductor 257 to the C segment of the segmented commutator ring 116.

In the event that the Z key lever were to be depressed instead of the space key lever, with the resulting movement of the contact swinger arm 36 associated therewith from engagement with contact point 37 to contact point 38, a circuit would be established from the battery 249, through the assumedly closed contact pairs 83 and 188, over the common conductor 245 to a junction point 259, over the short conductor 260 to the contact point 38 associated with the Z contact pile-up, through the movable swinger 36 in engagement therewith, and over the conductor 242 to the Z contact point of the code disc 243. The circuit would then be further established and traced through the reciprocal maze and to the C contact point of the code disc 243 and then to the C segment of the segmented ring 116, as just described. Therefore, it may be seen that in the enciphering operation, the depression of either the space key lever or the Z key lever will cause the recording of a single similar character, depending on the setting of the cipher unit or reciprocal maze.

Assuming that a selection is made just opposite to that previously described in an enciphering operation and it is necessary to depress the C key lever, an electrical circuit will be traced through the grounded battery 249, through the assumedly closed contact pairs 83 and 188, over the common conductor 245, through the contact point 38 associated with the C contact pile-up, through the movable swinger arm 36 associated therewith which will now be in engagement with contact point 38, and over the conductor 242 to the C contact point of the code disc 243. The circuit will be further traced through the reciprocal maze to the Z contact point of the code disc 243, over the conductor 242 to the swinger arm 36 associated with the Z key lever, through the contact point 37 with which it will be in engagement (Z key lever not selected), through the conductor 244 to the contact swinger 36 associated with the space key lever, through the contact point 37 in engagement therewith (space key lever not selected), through the conductor 252 to the movable contact arm 174, through the contact point 175 with which it is in engagement, and over the conductor 261 to the Z segment of the segmented ring 116 of the commutator 118. Therefore, it may be seen that in the enciphering operation no space will occur upon the depression of the space key lever.

After the operation described above for the printing of a selected character, the apparatus returns to its normal or unoperated position as initially described hereinbefore but as mentioned above, the type wheel 107 remains in the position whereat the selected character was printed and does not return to a zero position. Otherwise, the apparatus returns to a condition whereat another key lever may be selected, with all of the key levers in their upward or unoperated position and the bail 40 in its counterclockwise or nonblocking position.

Assuming now that an entire message has been enciphered and it is desired to decipher a message which has been handed to the operator, he would manually operate the lever 167 in a downward or clockwise direction, as viewed in FIG. 4. As a result of such operation of the lever 167 the upwardly extending arm 170 thereof would likewise move in a clockwise direction and the sidewardly extending lug at the upper extremity thereof would cam the pawl 151 in a clockwise direction out of engagement with the ratchet 155. At the same time the arm 172 would also move in a clockwise direction to a position whereat its sidewardly extending insulated lug 173 would engage the movable contact arm 174 and move it to a position out of engagement with the upper contact point 175 and into engagement with the lower contact point 176 (FIG. 5).

As previously mentioned, the message is enciphered or printed in groups of five characters, each group separated by a space. Inasmuch as the space is automatically included in the printing of the message and, as previously described, is automatically inserted by means of the operation of the double space pawl 151, the rendering unoperative of this pawl with respect to its associated ratchet 155 will preclude further automatic double spacing. However, a space will be obtained in the deciphering of the message because, as described above, at such time as a space was necessary in the printing of the message, the space key was depressed which caused the printing of the letter Z.

Inasmuch as the operation of the apparatus is similar in the deciphering of a message as in the enciphering, with the exception of the operation of the spacing, only the latter will be described.

In the previous example it was indicated that upon the depression of a Z or space key lever and through the electrical circuit established through the reciprocal maze, a resulting C would be printed on the tape. Now, describing the converse operation, assume that the instant coded message to be deciphered includes a C therein, and further assume that the contact pairs 83 and 188 are closed. Under this condition, upon the depression of the C key lever the movable contact member 36 associated therewith will move from engagement with they contact point 37 to engagement with the contact point 38, and conditions a circuit from the grounded battery 249, through the contact pairs 83 and 188, over the common conductor 245, through the contact point 38 associated with the C key lever, through the movable contact arm 36 now in engagement therewith, and through the conductor 242 to the C contact point on the code disc 243. The circuit would further be traced through the reciprocal maze to the Z contact point of the code disc 243, through the conductor 242 to the movable contact arm 36 associated with the Z key lever, through the contact point 37 in engagement therewith (Z key lever not selected), through the conductor 244 to the movable contact arm 36 associated with the space key lever, through the contact point 37 in engagement therewith (space key lever not selected), through the conductor 252 to the movable contact arm 174 associated with the lever 172, through the contact point 176 now in engagement therewith, and through the conductor 262 to the space segment of the segmented commutator ring 116. Thereafter, at such time as the brush arms 114 bridge the space segment with the grounded solid ring 117, the circuit will be completed for the energization of the magnet 86 and the resulting arrestment of the index wheel 112, through the lug 91 entering a notch therein, as previously described. In this position the index wheel 112 and the type wheel 107 would be arrested with a blank type pallet presented to the type hammer 135. Thereafter, upon the operation of the printing mechanism no legible character would be printed on the tape 206.

It is to be remembered, with respect to the description in the enciphering operation, that upon the depression of either a space key or the Z key, only the single character C would be printed on the tape; therefore, the letter C corresponds to either a Z or a space in the message. However, inasmuch as in the deciphering the depression of the C key lever will result only in a space occurring on the tape, in the event that a Z actually occurred in the communication the person deciphering the message would have to realize that from reading the message and insert it therein.

Inasmuch as the double space pawl 151 has been rendered unoperative, there will be no double spacing in the deciphered message but single spacing at every operation through the pawl 148 and associated ratchet 154. As previously described, the spacing between words will occur upon the selection of the C key lever which corresponds to the Z or space key lever in enciphering, and causes a blank to occur on the tape when selected.

It is obvious that the present apparatus need not be limited to the number of characters disclosed, but instead may operate with larger selections by increasing the number of key levers, the contact pile-ups associated therewith, the number of segments of the commutator 118, and the number of type pallets 108 and notches in the index wheel 112. Likewise, it is obvious that the apparatus need not necessarily operate on batteries of the flashlight type only but may be utilized with any suitable source of potential. Further, in the event that it is desired to design the apparatus, not as a ciphering unit but as a strict non-secret recording apparatus, the circuit arrangements could be altered for instance so that single contact points could be associated with each of the key levers which are connected directly to the associated segment of the segment of the segmented ring 116 of the commutator 118.

Although a specific embodiment of the invention has been shown and described, it will be understood that this embodiment is but illustrative and that various modifications may be made therein without departing from the scope and spirit of the invention.

What is claimed is:

1. In a printing telegraph apparatus, a keyboard including a plurality of keys, an electrical contact associated with and under the control of each of said keys, a commutator having a segmented and a solid ring, means to condition a segment of said segmented ring upon the selection of each of said keys and the closure of its said associated electrical contact over an associated electrical circuit, a rotary shaft, a brush arm on said shaft for bridging said solid ring and said segmented ring during rotation thereof, a type wheel on said shaft having an index wheel integral therewith, said index wheel being formed with a plurality of notches in the periphery thereof, a magnet, an armature associated with said magnet and being so positioned as to enter a notch in said index wheel during the energized condition of said magnet, means for storing energy for the rotation of said shaft, means operating immediately after the storage of energy in said energy storing means for releasing the latter to rotate said shaft, thereby causing said brush arm to traverse the individual segments of said segmented ring and to cause the energization of said magnet as said brush arm traverses the segment associated with said selected key, said armature thereby engaging said index wheel and arresting rotation of said type wheel, printing means, and means operating upon the arresting of rotation of said type wheel to cause the operation of said printing means to record the selected character.

2. In a keyboard operated printer, a keyboard having a plurality of keys, means to condition an electrical circuit upon the selection of one of said keys, a normally arrested type wheel having stop means, means to store energy for the rotation of said type wheel, a print hammer, means to set said print hammer and release said type wheel during the storage of energy in said energy storing means, means including trip-off mechanism operating automatically upon the storing of energy in said energy storing means for releasing the latter to rotate said type wheel, means acting during the rotation of said type wheel to complete said conditioned electrical circuit to cause through the cooperation of said stop means the arresting of rotation of said type wheel, and means operating upon the arresting of said type wheel to release said print hammer whereby said print hammer engages said type wheel to cause the printing of a character.

3. In a keyboard operated printer, a keyboard having a plurality of keys, means to condition an electrical circuit upon the selection of one of said keys, a normally arrested type wheel having stop means, means to store energy for the rotation of said type wheel, a print hamm'er, means to set sai-d print hammer and release said type Wheel during the storage of energy in said energy storing means, means including trip-01f mechanism operating automatically upon the storing of energy in said energy storing means for releasing the latte-r to rotate said type Wheel, means acting during the rotation of said type wheel to complete said conditioned electrical circuit to cause through the cooperation of said stop means the arresting of rotation of said type wheel, and means to prevent the completion of said electrical circuit until said print hammer setting means are retracted sufiiciently to permit said print hammer to engage said type wheel.

4. In a keyboard operated printer, a keyboard having a plurality of keys, means to condition an electrical circuit upon the selection of one of said keys, a normally arrested type wheel ha'ving stop means, means to store energy for the rotation of said type Wheel, a print hammer, means to set said print hammer and release said type wheel during the storage of energy in said energy storing means, means including trip-off mechanism operating automatically upon the storing of energy in said energy storing means for releasing the latter to rotate said type wheel, a magnet in saidcircuit having an armature, means associated with and acting during the rotation of said type wheel to complete said electrical circuit to cause the energization of said magnet,'said armature being attracted thereto to cause through the cooperation of said stop means the arresting of the rotation of said type wheel, and means operating upon the arresting of said type Wheel to release said print hammer whereby said print hammer engages said type wheel to cause the printing of a character.

5. In a keyboard operated printer, a keyboard having a plurality of keys, means to condition an electrical circuit upon the selection of one of said keys, a normally arrested type wheel having stop means, means to store energy for the rotation of said type wheel, a print hammer, means to set said print hammer and release said type wheel during the storage of energy in said energy storing means, means including trip-off mechanism operating automatically upon the storing of energy in said energy storing means for releasing the latter to rotate said type Wheel, means acting during the rotation of said type wheel to complete said conditioned electrical circuit to cause through the cooperation of said stop means the arresting of rotation of said type wheel, means operating upon the arresting of said type wheel to release said print hammer whereby said print hammer engages said type Wheel to cause the printing of a character, and means under the control of said print hammer to preclude completion of said electrical circuit until said print hammer is set and after said print hammer is released.

References Cited UNITED STATES PATENTS 867,868 10/1907 Beals 19712 1,054,582 '2/1913 Marchthal 19718 1,520,089 12/1924 Scherbius 197--12 2,365,913 12/1944 Stenfors 19718 ROBERT E. PULFREY, Primary Examiner.

Claims

2. IN A KEYBOARD OPERATED PRINTER, A KEYBOARD HAVING A PLURALITY OF KEYS, MEANS TO CONDITION AN ELECTRICAL CIRCUIT UPON THE SELECTION OF ONE OF SAID KEYS, A NORMALLY ARRESTED TYPE WHEEL HAVING STOP MEANS, MEANS TO STORE ENERGY FOR THE ROTATION OF SAID TYPE WHEEL, A PRINT HAMMER, MEANS TO SET SAID PRINT HAMMER AND RELEASE SAID TYPE WHEEL DURING THE STORAGE OF ENERGY IN SAID ENERGY STORING MEANS, MEANS INCLUDING TRIP-OFF MECHANISM OPERATING AUTOMATICALLY UPON THE STORING OF ENERGY IN SAID ENERGY STORING MEANS FOR RELEASING THE LATTER TO ROTATE SAID TYPE WHEEL, MEANS ACTING DURING THE ROTATION OF SAID TYPE WHEEL TO COMPLETE SAID CONDITIONED ELECTRICAL CIRCUIT TO CAUSE THROUGH THE COOPERATION OF SAID STOP MEANS THE ARRESTING OF ROTATION OF SAID TYPE WHEEL, AND MEANS OPERATING UPON THE ARRESTING OF SAID TYPE WHEEL TO RELEASE SAID PRING HAM-