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(11) | EP 0 038 225 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Electric typewriter |
| (57) The typewriter comprises a carriage 82, a mechanical keyboard and type character
support hammers. The hammers are connected to levers 62 which can be selected by the
keyboard keys and engaged via intermediate levers by a drive frame 73 for the striking
of the selected hammer. The drive frame is actuated by a solenoid electromagnet 92
which is connected to mains voltage and is controlled by a microprocessor by way of
a triac and rectifier. Carriage advancement takes place on each energisation of the
electromagnet unless specifically deactivated, and carriage return takes place by
means of a spring which is loaded during advancement. The carriage return 169 and
backspace 144 keys are connected to the electromagnet and microprocessor. In addition,
the carriage return key activates a sequence of commands executed under the control
of a mechanical member 176, 177. The microprocessor controls the positioning of the
carriage by means of a carriage spacing sensor, and then activates the execution of
the functions chosen on the keyboard if in agreement with the margins of the line
of type. The machine is also provided with a contact-type keyboard and a selector
by means of with four different margin and tabulation stop programmes can be memorised
in a non-volatile memory- The carriage tabulations are initiated by the contact keyboard
keys, which also comprises a set of decimal tabulators. |
[0001] This invention relates to an electric typewriter which may be a portable or office typewriter, comprising a set of type character support elements, a keyboard for selecting the character, and a cyclically operated power member for causing the element carrying the selected character to strike for typing purposes.
[0002] Typewriters of this type are known in which the power member is a drive bar pulled by a spring and controlled by a clutch driven by an electric motor. When it is required to carry out the various functions of the typewriter and in particular the carriage return, these functions are executed by the motor by way of clutches. The motor must be sufficiently powerful to move the carriage in a short time. Considering their weight and size limitations, these typewriters are very costly and cannot use those electronic solutions to margining and tabulation problems which are usable on standard typewriters.
[0003] The object of the present invention is to provide a portable and/ur office electronic typewriter which is of relatively low cost and has high performance in terms of speed, reliability and number of functions performed.
[0005] The invention will be described in more detail, by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a partly sectional side view of a typewriter embodying the invention;
Figure 2 is a view of certain parts of Figure 1 in a first operating position;
Figure 3 is a view of certain details of Figure 2 in a second operating position;
Figure 4 is a view of further parts of the typewriter;
Figure 5 is a plan view of certain details of the typewriter;
Figure 6 is a perspective view of certain details of Figure 4;
Figure 7 is a block diagram of an electronic control unit for the typewriter;
Figure 8 is a view of further parts of the typewriter;
Figure 9 is a detailed view of Figure 4;
Figure 10 is an electrical circuit of a block of Figure 7;
Figure 11 is an operating diagram of certain parts of Figures 7 and 10.
[0006] The typewriter uses a set of type character support hammers which can be selected by keys of a mechanical keyboard. The depression of each key is detected by a mocroprocessor which energises an electromagnet which is connected to the mains without the aid of transformers, and which supplies the energy for the striking operation. The electromagnet also executes the various typewriter functions such as back-spacing and carriage return, selected either directly from the keyboard or by way of a control member. The microprocessor controls the advancement of the carriage with respect to the margins, and executes the tabulations controlled by keys of the contact type.
TYPING MECHANISM
[0007] The electrical typewriter 30 (Figure 1) comprises four rows of typing keys 31 guided in slots 32 in a channel section 33. The keys 31 are pivoted on a shaft 34 and are provided with lower projections 35 which cooperate with leaf springs 36 formed from a strip 37 fixed to the frame 38. The springs 36 keep the keys 31 in their rest position, arrested by a tongue 39 against a transverse rubber block 40 fixed to the frame 38.
[0008] A series of lower shoulders 45, disposed at various heights on the keys 31, act as stops for the keys 31 against the block 40 in order to attain a constant operating stroke for the various keys independently of the row to which they belong. The distance of the projections 35 from the shaft 34 is calculated for the various rows so as to obtain a constant resistance force for each key 31.
[0009] Certain of the keys 31 arranged for the repeated typing of characters and indicated by 49 are also provided with a repeat element comprising a lever 50 pivoted on a pin 51 of the repeat key 49, and connected to it by a resilient joint formed by a spring 52, a lug 53 on the key 49 and a lug 54 on the lever 50. The lever 50 is provided with a lower shoulder 55 similar to the shoulders 45, while the key 49 is provided with a shoulder 56 disposed substantially higher than the shoulders 45 of the non-repeat keys belonging to the same row.
[0010] The leaf springs 36 are provided at their free ends with plastics push rods 60 arranged to cooperate with an intermediate lever 61 pivoted on a moving lever 62 of a corresponding typing hammer 63.
[0011] On the lever 61, constructed of plastics material, the pivot is a pin 63 of the moving lever 62, and the part engageable by the push rod 60 is constituted by a flexible finger 65 provided with a straight projection 66 and a circular projection 67. The lever 61 is connected to the lever 62 by a flexible joint formed by a spring 70 and is kept in its rest position with its shoulder 68 against tongue 69 of the lever 62. Each intermediate lever 61 is arranged to move an initiation frame 71 by means of the circular projection 67, and is arranged to be engaged and entrained by a drive frame 73 by means of a front shoulder 72.
[0012] The moving levers 62 are ;pivoted on a shaft 75, are connected to the hammers 63 by tie rods 76, and are kept at rest by a series of leaf springs 77 fixed to a cross bar 78. The hammers 63 rest on a bar 47 and are pivoted by pivots 80 on a hammer support cradle 79. The cradle 79 also guides each hammer 63 in such a manner as to cause the corresponding character to be struck on to the typing platen 81 by way of an ink ribbon 74. The cradle 79 is arranged to move vertically relative to the platen 81 for lower case-upper case shift. The platen 81 is supported by a carriage 82 movable transversely on a fixed guide 83 to define the line of type of the typewriter 30.
[0013] The initiation frame 71 is connected by a bridge 48 to a screen 84 disposed between a lamp and detector of an initiation sensor 85. The drive frame 73 is fixed to two rocker arms 86 and 87 which rock about the shaft 75 and are fixed above to a cross member 88. The arm 86 is attached at the top to the end of a typing spring 89 which tends to rotate the arms 86 and 87 in an anticlockwise direction. The arm 87 is connected at the bottom to a connecting rod 90, which is pivoted at 93 to the plunger 91 of a solenoid 92. The connecting rod 90 is also connected to the carriage displacement mechanism 115.
[0014] The solenoid plunger 91 (Figure 4) is provided at its other end with a striking surface 94 arranged to be arrested by a rubber block 95. A pin 96 rigid with the armature 91 projects from the surface 94, and is provided with a flange 97 which is normally halted by the rubber block 95 against the pull exerted by the spring 89 on the frame 73.
[0015] Turning to the mechanism 115, the connecting rod 90 (Figure 1) is provided with a lower appendix 116 which is pivoted on an arm 117 of a double arm lever 98 rotatable on a pin 99 fixed to the frame 38. On a pin 102 of another arm 101 of the lever 98 there is pivoted a tooth 103, one arm 110 of which (Figure 5) rests on a rubber stop 109 under the action of a spring 108. The tooth 103 is disposed in front of a space between two teeth of a sprocket wheel 104 rotatable on a fixed pin 105 and rigid with a pinion 106 which in its turn engages a rack 107 fixed on the carriage 82.
[0016] On the sprocket wheel 104 is fixed a disc 112 provided with a set of apertures 113 and rotatable between the lamp and detector of a spacing sensor 114.
[0017] The mechanism 115 also comprises a spring 120 which pulls the rack 107 towards the right for return of the carriage 82, and a retention tooth 121 pivoted on a fixed pin 122. The tooth 121 engages with the sprocket wheel 104 under the action of the spring 108 which acts on the tooth 103, and determines the various typing positions of the platen 81. A back-spacing tooth 124, pivoted on a pin 125, can engage with the teeth of the sprocket wheel 104 under the action of a spring 126. The tooth 124 is normally disposed a short distance from one of the teeth of the sprocket wheel 104 under the control of a tongue 127 of a lever 128. The lever 128 is pivoted on a pin 129 fixed on the arm 101 of the lever 98, and thus moves synchronously with the movable tooth 103.
[0018] The initiation sensor 85 and spacing sensor 114 are connected to a microprocessor 200 (Figure 7), which controls a power circuit 201 for energising the solenoid 92.
[0019] The operation of the typing mechanism is as follows. On depressing one of the keys 31 (Figure 1), its projection 35 deflects the spring 36 which, by means of the push rod 60, selects the lever 61 associated with the pressed key, by lowering its finger 65. By rotating about the pin 64, the lever 61 moves its shoulder 72 into the trajectory of the drive frame 73. Its projection 67 also acts on the initiation frame 71, removing the screen 84 from its position between the light and detector of the initiation sensor 85. The corresponding signal, received by the microprocessor 200 (Figure 7), activates the circuit 201, so energising the solenoid 92. The plunger 91 (Figure 4) is rapidly moved towards the left until the surface 94 strikes against the block 95.
[0020] The plunger 91 (Figure 1) thus causes the drive frame 73 to rotate in an anticlockwise direction by way of the connecting rod 90, against the action of the spring 89. The frame 73 engages the shoulder 72 of the selected lever 61 and entrains the lever 61 with it, to cause a clockwise rotation of the lever 62 against the action of the spring 77. By way of the tie rod 76, the lever 62 causes the corresponding hammer 63 to strike against the platen 81 and the corresponding character to be typed by way of the ink ribbon 74.
[0021] While the hammer 63 is striking, the appendix 116 (Figure 5) in moving backwards rotates the lever 98 in an anticlockwise direction, to move the tooth 103 and the back-spacing tooth 124 towards the left. After jumping over the tooth to the left of the engagement tooth, the tooth 103 becomes disposed in front of the space adjacent to the preceding space. The tooth 124 in its turn disengages from the sprocket wheel 104, and the two teeth 103 and 124 are both moved into the positions indicated by the dashed and dotted line. This therefore causes no movement of the carriage 82 (Figure 1).
[0022] After a predetermined time, the circuit 201 deenergises the solenoid 92, and the spring 89 causes the frame 73 to rotate clockwise, to return it to its rest position. During this movement, the cross member 88 entrains the previously displaced moving lever 62, so facilitating the action of the leaf spring 77, until the hammer 63 reaches its rest position on the support bar 47.
[0023] The forward movement of the connecting rod 90 and of its appendix 116 (Figure 5) causes the lever 98 to rotate clockwise. The tooth 103 is displaced from the position indicated by dashed and dotted lines to the rest position-indicated by full lines, and causes a tooth of the sprocket wheel 104 to advance, and the rack 107 to advance through one space. Because of the give of the rubber block 95 (Figure 4) and of the inertia of the moving parts, the plunger 91 moves beyond its end-of-stroke position. This enables the tooth 103 (Figure 5) to move beyond its operating position, so enabling the retention tooth 121 to jump over the tooth adjacent to the initially engaged tooth. The resilient reaction of the block 95 then returns the parts into the position indicated in Figure 1, but with the carriage 82 moved through one space to the left.
[0024] If a key 31, indicated by dashed lines in Figure 3 together with the parts connected to it, is kept depressed there is no repetition of the typing cycle. After the selection, the spring 70 returns the lever 61 upwards. When the lever 61 turns backwards, the front end of the finger 65 halts against the rear end of the push rod 60, so slightly deflecting the finger 65, but the circular projection 67 remains distant from the initiation frame 71 which keeps the screen 84 at rest.
[0025] If a key 49, indicated by a full line in Figure 3, is pushed completely downwards, when the lever 61 returns to rest the push rod 60 keeps the lever 61 lowered by means of the straight tongue 66 of the finger 65, and the circular projection 67 acts on the frame 71 to withdraw. the screen 84 from the sensor 85. The arrest of the shoulder 55 of the lever 50 (Figure 1) against the block 40 is signalled to the operator by the greater opposing resistance provided by the spring 52, until the key 49 reaches its end-of-stroke position defined by the shoulder 56. The space bar, not shown, operates in the same manner as one of the keys 49, without operating any hammer 63.
[0026] During the throw of the hammer 63 (Figure 2), even if the key 31 or 49 has been kept lowered, the projection 67 leaves the frame 71, which can thus at least temporarily return the screen 84 to rest, in order to reset the operating conditions.
SERVICE FUNCTIONS
Back-spacing
[0027] With reference to Figure 4, the typewriter 30 comprises a back-spacing key 144 arranged to select, by means of the spring 77 and finger 65, an intermediate lever 145 of a movable lever 146 similar to the levers 62. The lever 145 corresponds to the levers 61 of Figure 1, and by means of its projection 67 is arranged to cooperate with a frame 172 connected to a screen 162 disposed between the light and detector of an optical sensor 163 connected to the microprocessor 200 of Figure 7. The projection 67 is also arranged to cooperate with a lever 147 (Figure 4) which controls a microswitch 148 which is also connected to the microprocessor 200 of Figure 7. The moving lever 146 is provided with a tongue 149 arranged to engage the front edge of a slider 150 guided by two fixed pins 151 and 152. By means of its rear tongue 155, the slider 150 is arranged to cooperate with an arm 156 of a release lever 157 (Figure 5) pivoted on a pin 158. The lever 157 is arranged to cooperate with the sprocket wheel 104, and with an appendix 160 of the retention tooth 121. A spring 159 acting on the lever 157 also urges the slider 150 towards the frong, to keep it normally at rest against a drum 154 (Figure 9) provided with a cam which constitutes a function control member for the typewriter 30.
[0028] On depressing the back-spacing key 144 (Figure 4), the intermediate lever 145 is rotated with respect to the moving lever 146. The projection 67 activates the optical sensor 163 by means of a control lever 147 and the screen 162, and closes the microswitch 148 by means of the control lever 147. The microprocessor 200 (Figure 7) recognises the signal of 163, and makes the necessary settings for the backward counting of the carriage movement signals received by the sensor 114. In addition, having recognised the signal of the microswitch 148, it activates the circuit 201 in order to energise the solenoid 92.
[0029] The activation of the solenoid 92 (Figure 4) causes the drive frame 72 to move backwards and the moving lever 146 to rotate clockwise. The lever 98 (Figure 5) is rotated clockwise, and the tooth 103 engages that tooth of the sprocket wheel 104 to the left of that engaged when at rest. By way of the tongue 149 (Figure 4) and the appendix 155 of the slider 150, the moving lever 146 in its turn causes the release lever 157 (Figure 5) to rotate clockwise against the action of the spring 159. By means of the appendix 160, the lever 157 disengages the retention tooth 121 from the sprocket 104, and the spring 120 moves the carriage 82 backwards by slightly more than one space. When the tooth 103, which is limited in its rotation by the stop 109, is in the position indicated by the dashed and dotted line it engages the space to the right of that engaged when at rest. On de-energising the solenoid 92 (Figure 4), the return to their rest position of the slide 150, the lever 157 and the tooth 121 causes arrest of the sprocket 104 after a backward movement of one space of the carriage 82, while the tooth 103 (Figure 5) accompanies the sprocket wheel 104 to take-up that part exceeding the space through which the carriage 82 moved.
Carriage return
[0030] The typewriter 30 (Figure 4) is provided with a carriage return key 169 which is arranged, by way of the spring 77 and finger 65, to select an intermediate lever 170 of a moving lever 171 similar to the lever 145 and arranged to act on a control lever 172 of a microswitch 173 connected to the microprocessor 200 of Figure 7, and on the control lever 161 of the optical sensor 163. A pawl 174 is pivoted on the lever 171,and, under the action of a spring 175., cooperates with an input element of the function control member 154, constituted by a double toothed cam 176. The member 154 is provided with a further input element which comprises a six toothed cam 177, the teeth of which are grouped into two groups of three teeth disposed at 90° to the teeth of the cam 176. A pawl 178 pivoted on the arm 87 of the drive frame 73 and normally resting on the toothless zone of the cam 177 cooperates with the cam 177 under the action of a second spring 175. The movements of the pawl 178 have no effect on the member 154 during the operation of the frame 73 in the typing and back-spacing cycles of the typewriter.
[0031] The function control member 154 comprises as its output elements four cams 180, 181, 182 and 183 (Figure 6) which cooperate respectively with a cam follower lever 184, a slider 185, the slider 150 and a further slider 186. The lever 184 controls a line spacing mechanism of known type and not shown on the drawings. The slider 185 is kept against the cam 181 by a spring 187, and is provided with a rear projection 188 arranged to cooperate with the arm 110 of the tooth 103 (Figure 5). By way of an arm 190, a projection 189 on the slider 186 keeps a back-spacing lever 191, pivoted at 158, disengaged from the sprocket wheel 104 under the action of a spring 192 which keeps the slider 186 against the corresponding cam of the member 154 (Figure 4). Finally, a back-spacing pawl 193 cooperates with both the cams 176 and 177 under the action of a spring 194, to prevent retrograde movements of the member 154.
[0032] On depressing the carriage return key 169, the intermediate lever 170 rotates with respect to the moving lever 171. The circular projection 67 activates the optical sensor 163 by means of the control lever 161 and screen 162, and closes the microswitch 148 by means of the control lever 147. The signal of the sensor 163 is recognised by the microprocessor 200 (Figure 7) which makes the necessary settings for backward counting of the carriage movement signals received by the sensor 114. The microprocessor 200 recognises the signal of the microswitch 148, and activates the power circuit 201 in order to energise the solenoid 92.
[0033] The energisation of the solenoid 92 (Figure 4) results in the function control member 154 rotating through about 45° by way of the moving lever 171 and pawl 174. The cams 181 and 182 (Figure 6) causes the sliders 185 and 150 to move backwards, and the teeth 103, 160 and 124 (Figure 5) to disengage from the sprocket wheel 104 by the simultaneous rotation of the lever 98, and cause a partial operation of the line spacing mechanism.
[0034] The carriage which is thus released now moves towards its end position, urged by the spring 120 and braked by a brake, not shown.
[0035] When the microprocessor 200 (Figure 7) detects that the carriage has passed two spaces beyond the left hand margin, it activates the circuit 201 to give a sequence of three energisations of the solenoid 92.
[0036] On the first energisation, the pawl 178, operated by the arm 87, engages the first tooth of one of the two groups of three teeth of the cam 177 and rotates the control member 154 through a further 450. The cams 182 and 183 (see also Figure 9) allow the forward movement of the sliders 150 and 186. The retention tooth 121 (Figure 5) re-engages the sprocket wheel 104 to halt the carriage, and the back-spacing lever 191 prevents it from recoiling. The line spacing mechanism executes a second part of its own cycle.
[0037] On the second energisation, during the rearward movement of the plunger 91 (Figure 4), the member 154 is rotated through a further 450 and releases the tooth 103 (Figure 5) which becomes disposed in the position shown by the dashed and dotted line.
[0038] When the lever 98 returns to rest, the tooth 103 therefore moves the carriage forward to take-up one of the two spaces beyond the margin, while the line spacing mechanism executes a further part of its cycle.
[0039] The third energisation causes the member 154 (Figure 4) to rotate through a further 45°, which completes the line spacing cycle, while the tooth 103 moves the carriage forward in order to take-up the second space beyond the margin.
Lower case-upper case shift
[0040] With reference to Figure 8, the typewriter 30 comprises a lower case-upper case shift key 250 similar to the keys 31 of Figure 1, with one end of a connecting bar 252 pivoted on its key support lever by means of a corresponding pin 251. The other end of the connecting bar 252 is connected to one arm 253 of a bridge lever 254 by means of a joint comprising a pin 255, a slot 256 and a spring 257. The lever 254 is pivoted on a pin 258 and comprises a further arm 259 provided with a tooth 260 and an inclined edge 261 adjacent to the tooth 260.
[0041] By way of a spring 36 and the corresponding finger 65, the key 250 is arranged to select an intermediate lever 270 like the levers 61 of Figure 1 and arranged to cooperate with the initiation frame 71. The lever 270 is pivoted on a moving lever 271 provided with a projection 272 on which there rests a tongue 273 of a bridge 274 -under the action of a spring 280 on an arm 278 of the bridge 274. The bridge 274 is pivoted on a pin 275 about which the control member 154 rotates, and comprises a second arm 276 with a tongue 277 arranged to cooperate with the arm 259 of the lever 254. In its turn, the arm 278 engages a cross-member 279 of the hammer support cradle 79.
[0042] On the leaf spring 77 acting on the moving lever 271, there normally rests a dead key frame of a bridge 283 pivoted on the pin 275 and provided on one of its arms with a tongue 286 arranged to cooperate with an appendix 287 of the slider 185.
[0043] An shift-lock key 291 is pivoted on the lever of the key 250 by means of a pin 290, and comprises a lower tongue 289 connected to the key 250 by a resilient joint comprising a tongue 292 and a spring 293. The rest position and the stroke of the key 250 are limited by a pair of shoulders 294 and 295 arranged to cooperate with the block 40. The key 291 is provided below with a substantially vertical rear edge 296 and an inclined edge 297, arranged to cooperate with a front edge 298 of the frame 38.
[0044] On depressing the shift key 250, the intermediate lever 270 is selected by way of the spring 36 and corresponding finger 65, to activate the initiation sensor 85. The lowering of the connecting bar 252 causes the lever 254 to rotate clockwise, and disposes the arm 259 in the position indicated by the dashed line.
[0045] The microprocessor 200 of Figure 7 activates the circuit 201, which in its turn energises the solenoid 92. This moves the frame 73 backwards and entrains the moving layer 271 so that it makes a clockwise rotation. By means of the tongue 273, the relative appendix 272 then rotates the bridge 274 in an anticlockwise direction, to hook the tongue 277 to the tooth 260 of the arm 259 after its cooperation with the inclined edge 261 and the extension of the spring 257. The effect of the rotation of the arm 278 is to lower the cradle 79 and select the upper-case characters of the hammers 63 of Figure 1.
[0046] By means of the leaf spring 77, the rotation of the moving lever 271 causes the simultaneous, clockwise rotation of the dead key frame 284 and of the bridge lever 283. By means of the appendix 287, the tab 286 moves the slider 185 backwards so that its projection 188 (Figure 5) acts on the arm 110 of the mobile tooth 103, to withdraw it from the sprocket wheel 104 simultaneously with its movement towards the left by means of the double arm lever 98. Thus in this case the operation of the solenoid 92 causes- no movement of the carriage 82 (Figure 8).
[0047] The cradle 79 remains in the upper-case position for the entire time during which the key 250 remains depressed, by the stop action of the tooth 260 on the arm 276 even when the drive frame 72 has returned to its rest position, together with those parts of the displacement mechanism 115 which had been previously moved. In addition, the cradle 79 remains locked in the upper-case position on depressing the key 291. The key 291 firstly rotates about the pin 290 and moves the edge 296 of the tongue 289 into contact with the edge 298 of the frame 38, so stretching the spring 293. The key 298 then positively lowers the key 250 until the edge 298 engages the inclined edge 297. In this position, the key 250 remains locked in its lowered position under the action of the spring 36 and of a spring 299 which act on the key 250 and which prevail over the action of the spring 293 on the key 291.
Dead keys
[0048] Certain of the keys 31 of Figure 1 are."dead", i.e. do not give rise to movements of the carriage 82. For this purpose, the dead key frame 284 (Figure 8) extends over the entire width of the keyboard and is provided with specific tongues arranged to individually cooperate with the leaf spring 77 associated with the "dead" keys 31. On lowering one of these dead keys, as in the case of the shift key 250, the slider 185 (Figure 5) is moved backwards, and the escapement is excluded in the manner previously described.
Ribbon services
[0049] The ribbon 74 (Figure 1) is carried by a cartridge 265 mounted on a support 266 which swivels on the frame 38. The cartridge 265 and its support are of the type described in European Patent Application No 80300916.6 (.Publication No ) in the name of Ing C Olivetti & C, S.p.A. In the present case, the support 266 is raised and the ribbon 74 fed by the action of a lower appendix 267 of the support 266 (Figure 5) which cooperates with two tongues 267 of the lever 128.
[0050] During the throw of the hammers 31 of Figure 1, the clockwise rotation of the double arm lever 98 leads to raising of the support 266 (Figure 1) and of the ribbon 74, together with the feed of this latter.
Functions and electronic system
[0051] In addition to the keys 31, the machine 30 is provided with a function keyboard 205 of the contact type connected to the microprocessor 200 (Figure 7), and of which the keys have no direct mechanical connection with the typewriter. In particular, the keyboard 205 comprises fifteen keys, namely left hand margin 206, indentation 207, right hand margin 208, free margin 209, tabulation setting 210, eight tabulation control keys 211, a tabulation cancelling key 212 and a carriage centering key 213. In addition, the typewriter comprises a five position selector 214 also connected to the microprocessor 200 to select one of four different tabulation programmes and margins for the typewriter.
[0052] The microprocessor 200 is of known type, for example an INTEL 8048, and is also connected to a RAM memory 215 of known type, of CMOS form rendered non-volatile by means of a buffer battery 216. The RAM 215 permanently memorises the margin and tabulation data for the carriage set on the keyboard 205 and on the selector 214, for example in the manner described in published British Patent Application 2 046 966 in the name of Ing C Olivetti & C, S.p.A. An oscillator 217 connected to the microprocessor 200 and a buzzer 218 indicate when the carriage approaches the right hand margin and the need to operate one of the keys of the keyboard 205.
[0053] In the RAM working memory 224 the microprocessor 200 comprises cells 225 arranged to memorise the terms of spaces the distance of the carriage from the physical margin of the typewriter synchronously with the signals fed to the sensor 114. On starting the typewriter, since the position of the carriage is not known, the carriage is moved to the physical left hand margin and the cells 225 are zeroed. For this purpose, after the general start-up reset, the initialisation microprogrammes recorded in the ROM 226 of the microprocessor 200 accept only the operation of the carriage return key 169. On depress-ing this key, the return of the carriage to the end begins in the manner previously described. However, in this case, after the energisation of the electromagnet 92, the microprocessor 200 ignores the signals of the sensor 114, and carriage return is carried out without checking the spaces passed through, until the carriage stops at the physical margin. After a time of about two seconds from the operation of the key 169, which is certainly sufficient for this movement, the microprocessor 200 zeroes the cells 225 and feeds the circuit 201 with the sequence of three energisation commands for the solenoid 92, and completes the carriage return cycle in the manner previously described. The microprograms then, proceed with the movement of the carriage to the left hand margin memorised by the non-volatile RAM 215, or if this is absent, to a point distant eight spaces from the physical margin.
[0054] The value memorised by the cells 225 remains synchronised with the carriage position for the entire time in which the typewriter remains switched on, and the signals originating from the sensor 114 and indicative of a forward or backward movement of the carriage cause the number memorised by the cells 225 to increase or decrease only according to which of the two optical sensors 85 or 163 has been activated by the corresponding keys 31 or 144, 169. This synchronism cannot be lost because of uncontrolled movements of the carriage. In this respect, the carriage is normally blocked in each position by the retention tooth 121 (Figure 5) and by the back-spacing tooth 124, and can therefore not be moved manually by the operator.
[0055] In order to set the margins or tabulation stops, it is necessary only to press one of the keys 206, 208 or 210 (Figure 7) when the carriage has been moved into the required position by means of the typewriter keys. This causes the transfer and memorisation of the value of the cells 225 into one of four different zones of the non-volatile memory 215 selectable by the programme selector 214. During the typewriter operation, the values thus recorded are each time compared with the value of the cells 225. Five spaces before the right hand margin, the microprocessor 200 activates the oscillator 217 which causes an acoustic warning signal to be emitted by the buzzer 218. Having reached this margin, the microprocessor completely ignores any signals from the sensor 85 which can arise on operating the keys 31, so preventing any new energisation of the solenoid 92 and the striking of the selected hammer. On pressing the margin release key 209, the microprocessor 200 moves the right hand margin to the physical margin of the typewriter, and again correctly processes the keys 31.
[0056] The value of the left hand margin is also compared with the value of the cells 225, and causes the carriage to half at the margin set during the previously described carriage return stage. When the carriage is at the left hand margin, then on pressing the margin release key 209 the processor 200 moves this margin to a position corresponding with the physical margin of the typewriter.
[0057] Indentation is a special margin displaced five spaces to the right from the programmed left hand margin. To carry out the indentaiion, the key 207 is pressed, followed by the carriage return key 169. During carriage return, the microprocessor 200 instead of stopping the carriage in its end position, stops it five spaces before. If the indentation request is followed by a key other than the key 169, this request becomes cancelled.
[0058] For tabulation control, the eight keys 211 enable figures from 1 to 10,000 to be typed in columns. On operating the tabulator control I, the microprocessor 200 checks the actual position of the carriage in 225, compares it with the memorised position of the first tabulation stop, and activates the solenoid 92 a number of times equal to the number of spaces necessary for reaching the stop. The carriage moves through the same number of spaces as the number of actuations of the solenoid, and the microprocessor ceases to attract it when the tabulation stop has been reached. On pressing one of the other seven keys IT-VIII, the carriage instead of reaching the stop position stops 1 to 10 steps before, according to the key touched and the punctuation between triplets. If the sensor 163 is activated during execution of the tabulation command, the microprocessor interrupts execution of the tabulation cycles and follows the back-spacing or carriage return programme, which therefore takes precedence.
[0059] On pressing the key 212, any tabulation stop present in the attained carriage position is cancelled. In addition, if the key 212 is kept pressed and the carriage return key 169 operated, all memorised tabulations relative to the selected programme are cancelled.
[0060] As the carriage cannot be moved manually, in order to be able to put the typewriter away or transport it after use, microprograms are provided in a RON 226 for moving the carriage to its central position. These microprograms are initiated by pressing the.carriage centering key 213 followed by operating the carriage return key 169, In this case, carriage return is carried out without any check on the steps detected by the sensor 114, as in the already described initialization programme, until the physical left hand margin is reached. The microprocessor 200 then causes a number of actuation cycles for the' electromagnet 92 to be carried out in the manner typical of the carriage return, in order to move the carriage to its central position.
CONTROL AND POWER CIRCUITS
[0061] With reference to Figure 10, the circuit 201 comprises a bridge rectififer 230 connected to the mains voltage by means of a triac 231, its output terminals 229 being connected to the solenoid 92 by way of two resistors R1 and R2, a diode D1 and a condenser C1. The triac 231 is controlled by a unijunction transistor 232 which in its turn is controlled by way of an optoelectronic isolator 233 from two output lines 234 of the microprocessor 200. The logic components are fed from a low power transformer 235 and a stabiliser. 236, and the unijunction 232 and phototransistor of the isolator 233 are fed by a diode D2 and condenser C2 from a 15V tapping on the primary of the transformer 235, via a resistor network R3-R6. A condenser C3 accumulates the phototransistor charge until the unijunction 232 discharges.
[0062] The microprocessor 200 (Figure 7) is synchronised with the mains by means of a zero crossing circuit 240 of known type, which generates a pulse for each passage through zero of alternating mains voltage. The-asynchronous generation of the signal 85 (Figure llb) gives rise, in the microprocessor 200, to the generation of control processes for the lines 234 (Figure llc) which are synchronous with the mains (Figure lla) and spaced apart by two half periods independent of the duration of the lowering of the key 31. The microprocessor 200 of Figure 7 causes a second energisation of the solenoid 92 only after a time of eight half periods sufficient for the solenoid plunger to return to rest, which takes place in a time of 40 msec. (Fig lld), while it repeats the back-spacing at a cycle time of 160 msec. to give the operator sufficient time for stopping the carriage at the desired point. The movement of the carriage in one of these cycles takes place in a time of about 50 msec. CFig lle),
[0063] In the case of carriage return cycles, the operation of the solenoid 92 is conditioned not only by the signal of the sensor 114 (Fig llf) after the margin, but also by the moment in which the mains voltage passes through zero, so that it can cause stoppage of the carriage after a number of spaces greater than the two typical spaces. This however has no effect on the final positioning of the carriage, because in this case the microprocessor 200 causes the solenoid to make a number of carriage advancement cycles such as to move it to the predetermined left hand margin.
[0064] As the power unit of Figure 10 does not use power transformers for the solenoid 92, it is of very low cost and high reliability because of the constant conditions under which the solenid 92 is supplied at all moments during its operation.
[0065] It is apparent that various modifications can be made to the typewriter heretofore described within the scope of the claims. For example, instead of using type character support hammers, the machine could use a single type character support member, and the moving levers in this case could control variable positions of this type character support member.
1. An electric typewriter comprising a set of type character support elements (63),
a keyboard (31) for selecting a character, and a cyclically operated power member
(73) for causing the element carrying the selected character to strike for typing
purposes, characterised by a function control member (154) which can be selectively
actuated by the power member to execute mechanical control sequences relative to a
typewriter function, at least one key (169) for connecting the control member of the
power member, and an electronic circuit which responds to the operation of the key
in order to control the number of operating cycles of the control member.
2. Typewriter as claimed in claim 1, characterised in that the power member (73) moves
a pawl (174) connected to it, and that the function control member (154) comprises
a drum provided with a plurality of teeth (176, 177) movable under the control of
the key (169) from an inoperative position for the control member to an operative
position in which it is rotated incrementally by the pawl (174) and by a set of output
cams (180- ,183) in order to execute the functions associated with the incremental
rotations.
3. Typewriter as claimed in claim 1 or 2, comprising a typing area (81) for the type
character support elements (.63) which is mobile along a series of positions of a
line of type, and a spring (120) for bringing the areas to the beginning of the line,
characterised by a toothed member (104) synchronous with the positions of the area,
and a retention tooth (121) which retains the typing area in the attained position,
and in that the control member (154) is activated by a carriage return key (169) in
order to disengage the retention tooth from the toothed member until an end margin
is reached, and to re-engage the tooth with the toothed member when the margin is
exceeded.
4. Typewriter as claimed in claim 3, characterised by an advancement tooth (103) actuated
by the power member (73) and engageable with the toothed member (104) in order to
cause the typing area to advance through one position for each activation of the power
member, an element C185) controlled by the control member (154) to disengage the advancement
tooth from the toothed member jointly with the retention tooth (121), and to re-engage
the advancement tooth with the toothed member after the margin, and in that the electronic
circuit activates the power member (73) after the re-engagement of the advancement
tooth a number of times sufficient to bring the typing area to its end position.
5. An electric typewriter comprising a typing area (81) movable along a series of
typing positions of a line of type, a transducer (114) for incrementally determining
the positions and a memory (200) having cells associated with the typing positions,
and of which the content is synchronous with the positions of the carriage, and a
keyboard with keys which can be operated in order to move the typing area forwards
or backwards, characterised by a sensor (85) which senses the operation of a key which
moves the typing area forwards in order to increment the contents of the memory, and
by a further sensor (168) which senses the operation of the key which moves the typing
area backwards in order to decrement the contents of the memory, and by means (121,
124) which prevent the movement of the typing area independently of the keys.
6. Typewriter as claimed in claim 5, characterised by a cyclically operated power
member (73), a toothed member (104) synchronous with the positions of the typing areas,
an advancement tooth (103) actuated by the power member in order to cause the area
to advance, a retention tooth (121) for maintaining the area in the position attained
against the action of a spring (120), and a back-spring tooth (124) synchronous with
the advancement tooth which engages the toothed member in order to prevent any retrograde
movement thereof.
7. Typewriter as claimed in claim 6, characterised in that the toothed member comprises
a sprocket wheel C104) rotatable on the typewriter frame, and synchronous with the
typing area and with a synchronisation disc (106) comprising elements which indicate
discrete angular positions determinable by the transducer (114).
8. Actuation device for an electromagnetic power mechanism comprising an input member
and a microprocessor for programming the activations of the mechanism, characterised
in that the power mechanism (92) is directly connected to the alternating mains voltage
C230), and is controlled By a semiconductor switch (231), by a circuit (240) which
synchronises the microprocessor (200) with the phase of the alternating voltage and
by a circuit (232) controlled by the microprocessor which operates on the switch in
order to activate the power mechanism in response to a command of the input member.
9. Device as claimed in claim 8, characterised in that the semiconductor switch (231)
is a triac.
10. Device as claimed in claim 8 or 9, characterised in that the circuit comprises
an optoelectronic isolator (233) connected between the microprocessor C200) and the
switch (231).
11. Device as claimed in claim 8, 9 or 10, characterised in that the input member
comprises an optical sensor (85) activated by the operation of one or more keys (31)
of a keyboard of a typewriter.
12. Device as claimed in any of claims 8 to 11, characterised in that the power mechanism
comprises an electromagnet (92), the armature (91) of which activates the typing mechanism
of a typewriter.
13. An electric typewriter comprising a set of type character support elements (63),
a plurality of elements C61) for selecting the type elements and an electromagnet
(92) for causing the selected element (63) to type and for executing machine functions,
characterised by control elements (85, 163) which can be activated by the operation
of the selection elements (61), a rectifier (229) which supplies the electromagnet
with a pulsating voltage directly obtained from the alternating mains voltage, and
synchronisation means (240, 200, 231) which activate the rectifier in response to
the activation of the control elements and to a predetermined phase of the mains voltage.
14. An electric typewriter comprising a typing area (81) movable along a series of
positions of a line of type, a spring (120) for bringing the zone to the beginning
of the line, a power member (73) for the striking of the character to be typed, a
toothed member (104) synchronous with- the positions of the series, a tooth (103)
actuated by the power member in order to advance the area against the action of the
spring, and a retention tooth (121) for retaining the typing area in the attained
position, characterised by selection elements which can be set on command by the keyboard
in order to selectively disengage said tooth for the advancement of said typing area
and said retention tooth for maintaining said typing area in position and for moving
it backwards.
15. Typewriter comprising a set of keys (31), a set of setting elements (62) which
can be actuated in order to effect typing of a character and the execution of a function,
a drive frame (73) and a set of intermediate elements (61) carried by the setting
elements and selectable by the keys for their engagement with the frame and for the
actuation of the corresponding setting element, characterised in that each intermediate
element has a finger'(65) and by a part (36) operated by a depressed key which rests longitudinally on
one end of the finger in order to cause the intermediate element to engage with the
drive frame, and in that the finger loses its support during the actuation of the
setting element and engages in a non-operative manner on the said part after its return
to rest.
16. Typewriter as claimed.in claim 15, characterised in that the finger (65) is rigid
longitudinally and yieldable transversely.
17.. Typewriter as claimed in claim 15 or 16, characterised in that the part operated
by the keys (31) comprises the end of a leaf spring (36) which is deflected by a corresponding
key.
18. Typewriter as claimed in claim 17, characterised in that the keys (31) are carried
by corresponding levers of different lengths pivoted on a shaft (34) and disposed
along a number or rows, and are provided with projections (35) which act on different
points of the springs (36) associated with the two of the key in order to exert a
resistant force and to provide a substantially constant stroke for the keys of all
the rows.
19. Typewriter as claimed in any of claims 15 to 18, characterised in that the finger
(65) is provided with a lateral projection (66) on which the operated part (66) of
certain keys (31) can rest in order to repeatedly select the corresponding intermediate
element (61).
20. Typewriter as claimed in any of claims 15 to 19, characterised in that each of
the intermediate elements comprises a lever (61) pivoted on the corresponding setting
element (62) and connected to it by means of a flexible joint (70), and provided with
an appendix shaped in the form of a circular sector (67) concentric with the pivot
and arranged to operate a control frame (71) for the drive frame (73).
21. A typewriter comprising a set of type character support hammers (63), a set of
moving levers (62) connected to the hammers, a series of selection elements (61) associated
with the levers and which can be set in a working position for selecting each of the
hammers, and a bar (73) movable from a rest position to a working position to engage
the selection element set in its working position in order to move the moving lever
and cause the selected hammer to strike, characterised in that the bar (73) is activated
by an electromagnetic command (92) and is connected to a second bar (88) arranged
to return the moving lever of the selected hammer to rest after the hammer has stuck.