US2396188A - Calculating machine - Google Patents

Description

March 5, 1946. T. o. MEHAN ETAL 2,396,188

CALCULATING MACHINE Filed March 6, 1942 9 Sheets-Sheet -1 INVENTORS THOMAS C. MEHAN HUNTER E. HOOE ATTORNEYS March 5, 1946. T. o. MEHAN ETAL 2,396,188

CALCULATING MACHINE 9 Filed March 6, 1942 9 Sheets-Sheet 2 INVENTORS THOMAS 0. MEHAN HUNTER E. H005 QAMWZ M 1 'ATToR NEKS March 5, 1946.

T. o. MEHAN ETAL 2,396,188

CALCULATING MACHINE Filed March 6, 1942 9 Sheets-Sheet 3 INVENTORS. THOMAS O. MEHAN HUNTER E.H OOE A TTORNEYS March 5, 1946. 04 MEHAN ET 2,396,188

CALCULAT ING MACH INE Filed March 6, 1942 9 Sheets-Sheet 4 INVENTORS THOMAS C. MEHAN HUNTER E.HO0E

- A TTOR NEKS March 5, 1946. T. o. MEHAN ET AL CALCULATING MACHINE Filed March 6, 1942 9 Sheets-Sheet 5 THOMAS 0. MEHAN HUNTER E. HOOE ATTOR NE Y6 March 5, 1946. T. o. MEHAN ET AL CALCULATING MACHINE Filed March 6, 1942 9 Sheets-Sheet 6 INVENTORS. THOMAS O.MEHAN HUNTER E. HQOE I ATTORNEKS G (hob March 5, 1946. T. o. MEHAN ET AL gy CALCULAT ING MACHINE M w W INVENTORIQ THOMA C). MEHAN HUNTEE E. HOOE March 5, 1946. O MEHAN ET AL 2,396,188

CALCULATING MACHINE Filed March 6, 1942 9 Sheets-Sheet 8 JNVENTORS THOMAS QVMEHAN HUNTER E. HOOE C1: flMQZK ATTOR/VE rs March 5, 1946. T. o. MEHAN ET AL 2,396,138

CALCULATING MACHINE Filed March 6, 1942 9 Sheets-Sheet 9 ENTORS as .122 1 188 THOMAS O. MEHAN F16 HUNTER E-.HOOE- A TTOR NE Y6 Patented Mar. 5, 1946 CALCULATING MACHINE Thomas 0. Mehan, Park Ridge, and Hunter E. Hooe. Chicago, Ill., assignors to Victor Adding Machine 00., Chicago, 111., a corporation of Illinois Application March 6, 1942, Serial'No. 433,608

12 Claims.

Our invention relates generally to calculating machines, and more particularly to improvements in subtracting, positive and negative total taking, and control mechanisms for machines of this type. i

The invention is an improvement upon the machine disclosed in the prior applications of Thomas O. Mehan, Serial No. 372,289 and Serial No. 372,290, both flied December 30, 1940.

It is a primary object of our invention to provide an improved calculating machine capable of addition and subtraction (as well as division and multiplication by repeated addition and subtraction) in which positive or negative totals may be taken during the machine cycle immediately following an item entering cycle, that is, without the necessity of interposing one or more blank strokes.

A further object is to provide a calculating ma-- chine with an improved mechanism for the shifting of the accumulator between add and subtract positions.

A further object is to provide an improved carrying or transfer mechanism whereby transfers may be effected substantially instantaneously from the lowestthrough intermediateto the highest denominational order of the accumulator.

A further object is to provide an improved mechanism for taking credit balances.

A further object is to provide an improved overdraft key interlock mechanism, whereby mis operation of the machine is prevented.

A further object is to provide improved electrical control circuits for calculating machines.

A further object is to provide an improved calculating machine which is capable of performing a wide variety of calculating operations efiiciently and rapidly, which is simple in construction, and which may be economically manufactured.

Other objects will appear from the following description, reference being had to the accompanying drawings, in which:

Fig. 1 is a vertical sectional view, taken from the left side of the machine, and showing the numeral keys, the accumulator, and the actuating mechanism therefor;

Fig. 2 is a fragmentary vertical sectional view, taken just inside the left outer vertical frame of the machine, and showing particularly the means for shifting the accumulator between add and subtract positions, and the means for operating the actuator restoring bail;

to an enlarged scale, showing the accumulator and its associated operating mechanism;

Figs. 3 to 7 are fragmentary sectional views, showing portions of the transfer or carrying mechanism in the different positions assumed thereby in effecting transfers;

Fig. 8 is a right-side elevational view of a portion of the machine with the casing removed, showing particularly the control keys and linkage operated thereby;

Fig. 8a is a perspective view showing the connection between the credit balance, total, and subtotal keys and the subtract and add keys;

Fig. 9 is a left-side elevational view of a portion of the machine with the casing removed, and showing particularly the accumulator shift and the motor control mechanisms, and switches associated therewith;

Fig. 10 is a wiring diagram of the electrical control circuits shown in association with the mechanical elements which cooperate therewith; Fig. 11 is a perspective view showing the overdraft locking mechanism for preventing the depression of positive total taking keys when an overdraft exists in the accumulator;

Fig. 11a is a fragmentary side elevational view showing the key locking portion of the overdraft interlock mechanism;

Fig. 12 is a plan view of the accumulator mechanism, portions thereof being omitted to reveal the underlying parts; and,

Fig. 13 is a timing chart showing the sequence of operations taking place during listing and total taking cycles of the machine.

General description It is believed that the detailed description of the machine will be more readily understood if it is read with a general knowledge of the functions to be performed and the general manner in which the objects of the invention are attained.

The machine is of the key-set type, the keys controlling the positioning of actuators which operate the accumulators. Intermediate the actuator racks and the accumulators is a novel form of motion-transmitting mechanism where by transfer operations may be rapidly effected,

during a very short time near the beginning of an operating cycle. The accumulator pinions are shifted between add and subtract positions, depending upon which of the control keys is depressed, by electromagnetic means, which are operated substantially instantaneously upon de- Fig. 2a is a fragmentary vertical sectional view. pression of the control keys.

4 supported inte mediate the keys.

Means are provided automatically to add the fugitive one" as the amount entered in the accumulator changes from a positive to a negative value, and to subtract the fugitive one from the amount in the accumulator as such amount changes from a negative to a. positive value.

By virtue of the fact that the fugitive one is thus added or subtracted, and because the transfer or carry-over mechanism and the accumulator shift mechanism operate rapidly at the beginning of an operating cycle, it is possible to take a positive or negative total and clear the accumulators in the cycle of operation immediately following an item-entering cycle. The necessity of taking one or more blank strokes or spacing cycles is thus avoided.

The machine is provided with an improved electrical control circuit, whereby. upon depression of any one of the control keys. the accumulator is automatically shifted if such shift is necessary to perform the operation determined by the depressed control key.

Accumulator, and actuating mechanism therefor As shown in Fig. 1, the machine has numeral keys 20 which may be provided with any suitable flexible latching mechanism for their key stems 22, and are suitably supported and guided for vertical reciprocat ry m vement, the keys being retu ned to normal position by coil springs 24 extendin th ough a transverse row of keys and The lower extremities of the key stems 22 serve as sto s for cooperation with lu s 26 projecting sidewardly,

alternately in opDSte directions, from actuator slides 28. The stop lu' s 6 are arran' ed in vernier fashion so as to decrease the extent of necessary lon itudinal movement of the slides. Each of the slides has a bracket 90 secured thereto, these brackets bein suitably offset and each provided with a notch 32 enga' ea le with a pin 34 pro ectin'r sidewardly from an actuating rack 36. Each of the slides 28 is normally restrained from rearward movement (under conditions hereinafter to be desc ibed) by a zero stop hook 37. The slides in such of the denominational orders in which a key has been de ressed are released by clockwise swingin of their respective zero sto hooks 37 in a conventional manner.

The actuating racks 36 are mounted for longitudinal reciprocatory movement upon a pair of fixed guide rods 38 extending th ough slots 39, and are laterally spaced by s itable conventional means, such as combs M. The actuating racks 36 are normallv ur ed to move rearwardlv by tension springs 40 in the usual manner. Extending throu h slots42 formed in t e actuating racks 36 is a restoring bail bar 44, which is suitably guided in the center frame plates of the machine for reciprocation in the direction of the slots 42, such as by the slot 46 formed in the left-hand one of a pair of center frame plates 48, 49, A link 58 (Fig. 2) is suitably secured at each end of the restoring bar 44. The rearward ends of the links 58 are pivotally connected to arms 52, which are rigidly secured to a shaft 54, mountedfor oscillation in the center vertical frame plates. The arm 52 at the left-hand end of the shaft 54 is formed integrally with an off-set arm 96, which carries a follower roller 58, the latter being held in en agement with a plate cam 68 by a spring 6|. The cam 68 is secured to a main shaft 8'2.

As will hereinafter appear, the main shaft 62 rotates counterclockwise (Fig. 2) through a com plete revolution during each operating cycle of the machine. As may be observed from Fig. 2, and as indicated in the diagram of Fig. 13, the cam 60 has a depressed portion 64 followed by a slight rise 65, a dwell portion 66, a sharp fall portion 68, a. dwell portion 69, a rise portion Ill, and a final dwell portion 1| As a result of this shape of the plate cam 60, the restoring bar 44 moves in the following manner, as indicated in the chart of Fig. 13.

During the first 36 degrees of rotation of the main shaft, the restoring bar moves the actuating racks rearwardly from their normal position, which resets any tripped transfer pawls, as will appear hereinafter. As the depressed portion 64 of the cam passes the roller, the actuator racks 36 are moved forwardly, while the main shaft rotates from its 36 position to its 60 position. While the main shaft moves from its 60 position to its position, the dwell portion 66 of the cam is adjacent the roller 58 and the actuating racks 36 are thus held stationary during this period.

From the 75 position to the 108 position, the sharp fall portion 68 of the cam passes the roller 58, so that the actuator racks 36 move rearwardly to the position in which they are limited by the stems of any depressed keys, such movement taking place while the main shaft moves from its 75 position to its 108 position.

The rise portion 10 of the cam 60 commences engaging the roller 58 to move the restoring bar 44 forwardly when the main shaft is at its 243 position, such forward motion being completed when the main shaft reaches its 288 position.

An elbow-shaped arm I2 secured to a shaft 14 has a forked end 16 cooperating with a roller 18 secured to an extension of the arm 56, and is adapted to operate suitable mechanism for releasing the depressed keys at the proper time in the cycle of operation.

As best shown in Figs. 1 and 3 to 5, each of the actuator racks 36 has a rack portion 82 meshing with a segmental pinion 84. This pinion is mounted for rotation upon a shaft 86, and is keyed to a segmental gear 88 by a lug 98 partially punched from the segmental gear 88. An aligner bar 85 is provided to align the segmental gear 88 prior to effecting the printing.

The segmental gears each has cut-away portions 92 to receive a transfer sector 94 having three teeth in alignment with the teeth of the segmental gear 88. The transfer sector 94 is secured to a hub 95, which is mounted for rotation on the shaft 86. The transfer sector 94 is normally urged clockwise (Fig. 3), with respect to its adjacent gear segment 88, by a tension spring 96. one end of which is suitably anchored to the gear segment 88 and the other end of which is attached to an ear 98, extending from the transfer sector 94. The transfer sector 94 is normally held a definite arcuate distance, (corresponding to the tooth pitch) from the segmental gear 88 by the stop face 99 of a transfer pawl I00. When the transfer pawl is tripped, as will hereinafter be described, the stop face 99 moves radially inwardly with respect to a stop lug H02 formed on the transfer sector 94 and permits the latter to move clockwise under the influence of its spring 96 and enter a notch I84 formedin the transfer pawl [I88 (Fig. 4).

The accumulator comprises a plurality of accumulator wheels Q88 (pinions) mounted for free rotation upon a shaft 688. these pinions being at all times in mesh with subtract pinions H0 mounted upon a shaft M2, and the latter, as

shown in Fig. 2a, meshing with idler pinions II4 mounted upon a shaft III, the idler pinions meshing with pinions "8 attached to visible dial wheels I20 mounted for free rotation upon a shaft I22. The shafts I08. H2, H8, and I22 are rigidly secured to a pair of accumulator frame plates I24 and I28.

The ends of the shafts I08 and I I2 are provided with bushings I28 located in slots I28 formed in the cradle side plates I30 and I3I. The cradle side plates I30 and I3I are secured together to form a rigid cradle by rods I32, I33, and I34, the rod I33 extending beyond the outer surfaces of the cradle frame plates I30 and I3I, and into suitable openings formed in the center section frame plates 48, 48, to provide a pivot for the cradle.

The cradle for the accumulators is rocked to bring the accumulator wheels I08 into mesh with the segmental gears 88 (or to bring the subtract pinions into meshing engagement, provided a subtract operation is to be performed) by suitable mechanism, best shown in Fig. 2a.

This mechanism comprises a link I38 pivoted on the rod I34. A lost motion pin and slot connection is provided between the lower end of the link I36 and the rearwardly extending arm I38.

y when in the position shown in Fig. 2a, prevents lost motion between the link I36 and the arm I38. This non-add latch I44 is swung rearwardly free from engagement with the pin on the arm I38 when a non-add operat on is to be performed, so that the raising and lowering of the operating link I42 will be ineffective to swing the cradle.

The swinging movement of the accumulator carrying cradle is limited by a pin I46 proiecting inwardlv from the right center frame plate 49 and embraced in an elongated slot I48 formed in an ear I50, depend ng from and forming part of the cradle side plate I30. The ear I50 also has a nose portion I52 cooperable with a detent I54 pivoted on the shaft 86 and operated by a tension spring I56.

The transfer pawls I are pivoted on a shaft I58 carried in the center frame plates 48 and 49 and each urged to swing clockwise (Fig. 2a) by a tension spring I60 attached to the forwardly extending portion of the transfer pawl I00 and a rearwardly extending arm I62 of a transfer pawl latch I64. The latch I64 is notched at its upper end to receive the downwardly extending hook IE6 at the forward end of the transfer pawl I 00. Each of the accumulator pinions I06 is provided with a transfer cam tooth I68, and each of the subtract pinions H0 is similarly provided with a transfer cam tooth I (Fig. 3). The transfer cam teeth I68, "0 (depending upon whether an adding or subtracting operation is being performed) are adapted to contact a nose projection I'I2 formed on the transfer pawl I00 when a transfer is to be effected.

Such engagement causes the transfer pawl I00 to be swung counterclockwise (F g. 2a), whereupon the latch I 84 associated therewith is released from the hook I68 and swings clockwise so as to hold the transfer pawl I00 in tripped position, such holding being effected by the positioning of end portion I14 of the latch I84 beneath the hook I88.

The latches I84 are restored incidental to the disengagement of the accumulator or subtract pinions from the actuators when the side plates I for the accumulator pinions I08 and subtract pinions II 0, respectively, to hold the pinions against rotation when they are not in engagement with thesegmental gears 88.

In order to insert the fugitive one" and to subtract it at the proper times when the amount entered in the accumulator pinions changes from a positive to a negative value, and vice versa, the transfer pawls I 00a and I 00b, respectively, for the highest and the lowest denominational order accumulator pinions I08, have a rearwardly extending portion I18.

Accumulator shifting mechanism As previously indicated,,the frame comprising the accumulator frame plates I24, I26 is shiftable in the cradle frame plates I30, I3I, to bring either the accumulator pinions I06 or the subtract pinions I I0 in position for engagement with the segmental gears 68. Such shifting of these pinions is accomplished electromagnetically by a pair of solenoids I80, I82, having plungers I8I and I83, respectively. As best shown in Figs. 2 and 10, the plungers I8I and I83 are pivotally connected to the ends of a lever I84 centrally pinned to the shaft 86. Likewise secured to the shaft 86 is a pair of forked arms I88, the forked upper ends of which embrace sidewardly extending studs I88, which are secured to the accumulator frame plates I24, I25, respectively.

Thus, when the solenoid I isenerg zed, the accumulator pinions I06 are brought to the position shown in Fig. 3, where they may be brought into mesh with the transfer sectors 94 and gear segments 88. When in this position, the transfer cam teeth I86 are in positions such that they may operate the transfer pawls I00 and I00a. On the other hand, when the solenoid I82 is energized, the accumulator assembly will be moved to the position shown in Figs. 1 and 10, wherein the subtract pinions I I0 are in position for engagement with the transfer sectors 94 and gear segments 86, and the transfer cam teeth I10, associated with these pinions, may cooperate with the transfer pawls I00 and MM for effecting transfer operations.

The accumulator assembly is heldin the particular position to which it is shifted upon operation of either of the solenoids I80, I82 by a detent lever I90 (Fig. 9) suitably pivoted upon a stud I9I and urged counterclockwise by a suitably anchored tension spring I92. The rearward arm of the detent lever I90 carries a roller I94 cooperable with the pointed end I96 of lever I98, the latter lever being pinned to the shaft 86.

Control keys and operating controls Referring to Fig. 8, it will be seen that the machine is provided with a plurality of control keys, including a non-print control key 200, a non-add key 2M, 9. sub-total key 202, a total key 203, a credit balance key 204, a repeat key 205, an error key 206, an add key 201, and a subtract key 208. The keys 200 to 206 operate in a manner more fully disclosed in the aforesaid copending applications Serial No. 372,289 and Serial No. 372,290, to determine thecharacter of the operating cycle to be performed. In addition, the keys 20l to 204, inclusive, are individually operable to close a switch 2l0, which, as will hereinafter appear, results in the energization of the driving motor for initiation of a cycle of operation of the machine.

The add key 201 has an off-set stem 2 I2, which, at its lower end, is provided with a foot 2. Similarly, the subtract key 208 has an off-set stem 2 l 6 provided with a foot 2l8. The key stems U2 and 216 are provided with longitudinal slots embracing guiding studs 220 and 22 I. An interlock finger 222 is freely pivoted on the stud 220 and has cam faces for engagement with studs 223 and 224 projecting sidewardly from the key stems 2|2 'and U6, respectively, and prevents simultaneous depression of the keys 201 and 208.

The key 201 is adapted to be held in depressed position by a latch 226, while a similar latch 221 is provided for the subtract key 208. These latches, upon complete depression of the key 201 or key 208, are adapted to hook beneath the studs 228 or 229, respectively, to hold down the depressed key during a predetermined portion of the operating cycle. The latches 226 and 221 are adapted to 'be released by a reciprocatory slide 230 operated by suitable mechanism driven. from the main shaft 62.

As shown in Fig. 8a, the credit balance key 204 is adapted, upon depression, to swing clockwise a rocker plate 232 suitably supported in the keyboard assembly, the rocker plate 232 having a rearwardly extending arm 234 which overlies a pin 236 projecting inwardly from the key stem 2|6. In a similar manner, the sub-total key 202 and total key 203 are each provided with rocker plates having arms engageable with studs 238 and 239, respectively, which are secured to the adding key stem 2H2.

Depression of the add key 201 causes its foot 2l4 to close a switch 240 and thereafter to close a switch 242. In a similar manner, complete depression of the subtract key 268 causes the foot 2l8 of its key stem successively to close switches 244 and 246.

Electrical circuits and motor control Referring to the circuit diagram, Fig. 10, the switches 240 and 244 are respectively connected in series with switches 250 and 254 and with the windings of solenoids 880 and H82, respectively. Thus, in order to energize the solenoid E80, switches 250 and 240 must be closed, while, to energize solenoid E82, switches 254 and 244 must be closed.

As best shown in Fig. 9, an arm 256 is rigidly secured to the left-hand end of shaft 86, and at its free extremity carries an insulating bushing 258, which is adapted alternately to open switches 250 and 25%, depending upon the position to which the accumulator assembly has been shifted.

It will be noted that the switches 242 and 246 are respectively closed subsequently to the closure of the switches 220 and 2434. The switches 242 and 246 are connected in parallel with each other and in parallel with switch 2| 0, these three switches being arranged in series circuit with the winding of a solenoid 260 and in series with a switch 26l. As more fully disclosed in the copending application of Thomas 0. Mehan, Serial No. 359,271, filed October 1, 1940, and also as illustrated generally in Figs. 9 and 10, the energization of the solenoid through a suitable linkage trips 8. one-revolution clutch mechanism 262 and therethrough closes a motor switch 264 to energize a motor 266. Tripping of the one-revolution clutch mechanism 262 results in opening the switch 26L and thus deenergizing the solenoid 260. The circuits are illustrated as being supplied with electrical energy from line conductors 268, 269, which may supply direct current or alternating current.

Overdraft interlock As best illustrated in Figs. 11 and 11a, means are provided to lock the total key 203 and subtotal key 202 against depression when the accumulator contains a negative balance, and to lock the credit balance key 204 against depression when the accumulator contains a positive balance. Thus, attempted misoperation of the machine by depression of the wrong key 202, 203, or 204 is prevented. Furthermore, the interlock provides a warning indication to the operator, especially of the existence of an overdraft, the indication being provided by the inability of the operator to press the total and subtotal keys.

This mechanism comprises a cam 210 which is secured to and is rotatable with the highest order subtract pinion 0. This cam, when the accumulator assembly is in subtract position (shown in Fig. 11) is adapted to engage the rearward toothed portion 212 of a bail 214, the latter i n'cunted for free pivotal movement on a stud When the accumulator assembly is shifted to its add position, the cam 210 will be in position to engage the forward toothed portion 218 of the bail 214. The bail 214 is provided with a forwardly extending arm 280 pivotally connected by a pin 282 with a link 284. The link 284 is pivotally connected to an arm 286 secured to a shaft 288 suitably mounted in the center frame plates of the machine and having an arm 290 rigidly secured at its right-hand end. This linkage is adapted to be held in the position in which it.is moved, by a spring 29B frictionally engaging the link 284.

A locking slide 292 has a pivotal pin and slot connection with the free end of the arm 290 so as to be reciprocated by angular oscillation of the shaft 288. The locking slide 292 is suitably guided for longitudinal movement in the keyboard assembly and has a pair of stop lugs 294, 295 bent upwardly therefrom. As shown in Fig. 11a, when the locking slide 292 is in its rearmost (full line) position, the lug 295 is positioned beneath the credit balance key 204, while the lug 294 lies in a position between the subtotal key 202 and the total key 203, so that these latter keys may be freely depressed. When the locking slide 292 is moved forwardly to the position indicated in dotted lines in Fig. 11a, the stop lug 294 is in position to prevent depression of the subtotal key 202, while the stop lug 295 is in position beneath the total key 203 to prevent depression thereof. In this position, the stop lug 295 is no longer beneath the credit balance key, so'that the latter may be operated.

Operation priate amount keys 20. While the keyboard is indicated as of the full flexible type, it will be readily understood that this is not essential and that a ten-key amount-setup mechanism may be employed.

After setting up he amount, the operator depresses either the dd key 201 or the subtract key 208, depending upon the character of the operation to be, performed. If, for example, the preceding operation has been a subtract operation and the operator depressed the add key 207, the initial portion of the downward stroke of the add key 201 results in closure of the switch 240. As best illustrated in Fig. 10, and as previously described, closure of the switch 240 would, in this instance, result in the energization of the solenoid I80. Under the assumed initial conditions (with the accumulator assembly in subtract position), the arm 258 is in the position shown in Fig. holding the switch 254 open, and with the switch 250 closed. A circuit is thus established from the line conductor 268, through the switches 240 and 250, through the winding of solenoid I80, and hence to the line conductor 289. The completion of this circuit will, through the energization of the solenoid I80, swing the accumulator assembly to the add positions, where it will be held by the detent I90 (Fig. 9). The accumulator pinions I08 are thus in the positions shown in Figs. 3, 4, 6, and 7.

Further depression of the add key 201 results in the closure of switch 242. Since the drive mechanism is assumed to be in normal position, the switch 28I will, at this time, be in closed will, as previously described, commence moving forward until at the 60 position of the main shaft, the gear segments 88 and transfer sectors 94 will be in their normal positions shown in Fig. 3. After being held in this position from a 60 to a 75 position of the main shaft, such of the racks as have been released by their zero stops 31 (due' to the depression of a key in the associated bank of keys) will move rearwardly with the restoring bail bar 44 until arrested by the depressed key stems. As indicated in Fig. 13, all of the racks will have moved rearwardly to the limit permitted by their associated set keys when the main shaft has rotated through 108. When in this position, the segmental gears 88 are locked in, aligned position by the aligner bar 85, and, after the main shaft has moved toits 207 position, the accumulator pinions I06 are rocked into engagement with the gear segments 88.

As the main shaft reaches its 231 position, the accumulators will be fully enmeshed with the gear segments 88 so that at the 234 position of the main shaft, the aligner bar 85 may be, and is, moved from engagement with the segmental gears -88. At the 243 position of the main shaft, the

aligner bar will be fully disengaged and the reposition so that the closure of the switch 242 will result in the establishment of a circuit, which may be traced as follows: From the line conductor 288, through switches 26I and 242, and winding of solenoid 280 to line conductor 269. This will result in the energization of the solenoid 260 and the tripping of the one-revolution clutch mechanism 262. Such tripping of the clutch mechanism results in opening the switch 28I to deenergize the solenoid 280 and closure of the switch 284, thus connecting the motor 266 across the line conductors 288 and 269.

The motor will thus commence driving the main shaft 62 through the one-revolution clutch mechanism 282, and, by means of the cam 60 (Fig. 2) move the restoring bail bar 44 rearwardly a short distance sufficient to move the segmental gears 88 from the positions in which they are shown in Fig. 3 to the position shown in Fig. 5. In this position, the gear segment 88 is in contact with the transfer sector 94 and holds the latter sufficiently counterclockwise from its normal position to permit any of the transfer pawls I00 which may have been moved to transfer position in a preceding cycle (as in Fig. 4), to swing from the dotted line position of Fig. 5 to the full line position. Such restoration of any previously actuated transfer pawls I00, No, is permitted, since at this time, the accumulator cradle frame plates I30 and I8I are in the position shown in Fig. 2a, in which, it will be noted, the transfer pawl latches I84 are swung sufllclently counterclockwise to permit the springs I80 to move their respective transfer pawls I00, I 00a, to normal position.

Following restoration of the transfer pawls I 00, Na, and after the main shaft has rotated through 36, the actuator restoring bail bar 44 storing bail bar 44 will commence moving forward, and reaches its normal forward position when the main shaft is'at its 288 position. Dur. ing the course of such movement, the actuating racks 38 which have been displaced due to the operation of a numeral key in their associated key banks will be successively picked up by the restoring ball 44 and returned to normal position, Where they will be relatched by their zero stop hooks 31.

If, in the course of the forward movement of the actuator racks 38, one of the accumulator pinions I03 is rotated from its 9 to M0 position, its transfer cam tooth I68 trips the transfer pawl I00 or lIlOa associated with the next highest denominational order so that the latter moves from the full line to the dotted line position of Fig. 5. The transfer sector 94 of the order into which the transfer is effected is thus permitted to be restored with its segmental gear 88 to the position in which it is shown in Fig. 4, and the accumulator pinion I06 in mesh therewith will thus be advanced an additional tooth space since the transfer sector 94 forms in effect a continuation of the gear segment 88.

After the main shaft reaches its 348 position, the accumulator pinions I06 are moved away from the segmental gears 88 and transfer sectors 94 so that as the cycle of operation is completed the accumulator pinions will again be in the positions in which they are shown in Figs. 3 and 4 and will have had the amount set up on the keyboard addedto the registration which may have initially been contained therein.

It will be noted that in an ordinary listing operation (as well as other types of operating cycles to be described hereinafter), the transfer pawls I00, I00a are reset during the initial 60 movement of the main shaft-so that transfer operations may be rapidly performed during the limited time that the accumulators are in engagement with their actuating gears 88 and transfer sectors 94. Furthermore, it will be noted that the movement of the transfer sectors 94 is effected by the springs 98, and that because of the relatively light weight and low rotary movement of inertia of the transfer sectors 94, these parts may move rapidly to the position in which they effect a transfer (1. e., from the position of Fig. 3

to that of Fig. 4). Thus, for example, if the accumulator contained the registration of the amount 999,999,999.99 prior to the start of the adding cycle, it will be apparent that if the amount added during the adding cycle was 1, all of the transfer pawls will have to be tripped. The energy for tripping the pawls I00, M011, and for rotating the accumulator pinions each through one step and effecting a transfer of the type indicated, is obtained from the stretched springs 96. Thus, the latch is capable of performing successive transfer operations from the units to the highest order accumulator pinion without requiring the movement of relatively heavy parts having considerable inertia, which would tend to slow do wn the transfer operation.

In performing a subtract operating cycle, the operator presses the keys representing the amount to be subtracted and follows this with the depression of the subtract key 208. The initial downward movement of the key 208 results in closure of the switch 2, which, as will be apparent from the wiring diagram of Fig. 10, completes a circuit through the solenoid H02.

As the latter is energized, the accumulator assembly is shifted from the position in which it is shown in Figs. 3 and f to the position in which it is shown in Figs. 1, 2a, and 10, in which position the subtract pinions i W are in position to be engaged with the segmental gears fit and transfer sectors 94.

Further depression of the subtract key 208 results in closure of the switch M0, which completes the circuit to the one-revolution clutch mechanism solenoid 260 in the same manner as was previously described as occurring upon the closure of switch 202.

The operating cycle of the machine commences, and all parts operate in the same manner as previously described with reference to the adding cycle, except that the subtract pinions M0, instead of the accumulator pinions i06 are brought into mesh with the gear segments 83 and transfer sectors 94, and the transfer pawls M0, M01; are actuated by the transfer cam teeth 8'50 of the subtract pinions IIO instead of by the corresponding transfer cam teeth of the accumulator pinions. Since the subtract pinions Ilflil are geared directly to the accumulator pinions 506, the amount set up on the keyboard will be subtracted from the registration contained in the accumulator pinions in the well known manner.

To illustrate a simple example involving a neg= ative total, that is, a true total obtained when a greater amount is subtracted from a lesser amount, 4 subtracted from 3, for instance, the following operations occur: Assume that 3 has been entered into the units accumulator pinion I06, as illustrated in Fig. 5, with its transfer cam tooth I68 in the position th re shown. Then assume that digit 4 is set up in the keyboard, followed by a depression of the subtract key 208, to perform a subtract operating cycle, in the manner previously described.

It will be recalled that the initial portion of the downward stroke. given subtract key 208 results in shifting the subtract pinions i 00 to proper po' sition for meshing with the segmental gears 88 and transfer sectors 94 if, as in the present example, the preceding cycle was an adding operation. Thus, the units subtract pinion IIO will be in position to mesh with the units segmental gear 88 (Fig. 12), and when so meshed, will be rotated four toothed spaces counterclockwise during the subtract cycle by virtue of the digit 4 set up in the keyboard. During such four toothed rotation of the unit subtract pinion IIO, its associated transfer cam tooth I10 will trip its transfer pawl I00 when said pinion -I I0 moves between its 9 to 0 position to effect a transfer into the next highest denominational order subtract pinion. Such transfer operation accordingly takes place successively through the higher denominational order subtract pinions IIO until the tooth I10 of the highest denominational order pinion IIO trips its associated transfer pawl |00a (Fig. 12). When this pawl I00a is tripped, the transfer pawl I00b is likewise tripped through the tie bar I18. and the unit order subtract pinion III] is thereby moved one additional toothed space to enter the fugitive one in the subtract pinion H0 of lowest order. At this time, the registration in the subtract pinions H0 will read 000,000,000.01.

It may be convenient at this time to refer to the corresponding operation of the accumulator mechanism as the registration in the accumulator is changed from a negative value to a positive value. Such change would, of course, occur while the accumulator pinions I06 are in mesh with the actuating gear segments 88 or transfer sectors 94. With a registration of 999,999,999.99, all of the transfer cam teeth I68 of the accumulator pinions I06 will be in position about to trip their associated transfer pawls I00, l00a. Thus, any further (counterclockwise. Fig. 3), movement of the units accumulator pinion I06 will trip the tens order transfer pawl I00 and advance the tens accumulator pinion I06 one tooth counterclockwise. This transfer will be carried through, in similar manner, to the highest order accumulator pinion I00, and from the latter to the units order accumulator pinion thus reinserting the fugitive one.

When a subtotal is to be taken, the subtotal key 202 is depressed. Depression of this key through its rocking plate 232 operating upon pin 238 depresses the key stem 2I2 of the add key 201', and, in the manner previously described sufficiently to close switch 240, thereby shifting the accumulator assembly to the add position (if it was not previously in that position) and subsequently by closure of switch 2H1 energizing the driving motor to start an operating cycle.

As the main shaft 62 reaches its 60 position, the accumulator pinions I06 are moved into mesh with the gear segments 88 and transfer sectors 94, and are retained in mesh throughout the rearward and forward travel of the actuating racks, being disengaged from the gear segments 83 and transfer sectors 94 as the main shaft reaches its 231 position.

In the sub-totaling operating, the zero hooks 31 are operated to release all of the actuating racks in the usual manner so that their movement may be limited by the engagement of the radial faces of the transfer cam teeth 868 with the cooperating surfaces of the noses N2 of the transfer :pawls I00, I00a, all in a well known manner, so that printing of the sub-total may be effected.

In effecting a total operation, the total key 203 is operated, and an operating cycle corresponding closely with that described above with reference to taking a sub-total is performed by the machine, with the exception that the accumulator pinions I06 are disengaged from their gear segments 88 and transfer sectors 94 as the main shaft 62 moves from its 207 to its 231 position so that the accumulator is cleared.

It will be understood that neither a total nor sub-total operation can be performed by the machine while a credit balance or overdraft is present in the accumulator. Such operation is prevented by the overdraft locking mechanism shown particularly in Figs. 11 and 11a. When a credit balance is present in the accumulator and It is desired to print the credit balance and clear the ,machine, the credit balance key 204 is depressed.

During the initial portion of the downward stroke of the key 204, it will, through the rocking plate 232, its arm 234, and pin 230, depress the subtract key stem 2I6 sufficiently to cause closure of the switch 2, thereby assuring that the accumulator assembly will be in its subtract position, energizing the solenoid I82 if necessary to thus shift the accumulator assembly. Such shifting is necessary whenever the preceding cycle of the machine was an adding cycle.

Further depression of the credit balance key 204 results in closure of the switch 2I0 and consequent energization of the one revolution clutch mechanism solenoid 260. In the course of the credit balance operating cycle, just as in the sub-totaling and totaling cycles, the zero hooks 31 are released during the operating cycle to permit the actuating racks 36 to move rearwardly to an extent determined by the positions of their associated subtract pinions H0. The rotation of the subtract pinions I I is limited by the engagement of the radial faces of their transfer cam teeth III) with the cooperating faces of the noses I72 of the transfer pawls I00, I00a. When all of the subtract pinions have been arrested in this position, the accumulator pinions I06 are in positions corresponding to a registration of 999,999,- 999.99. This might be termed a "negative zero" position of the accumulator pinions I06 since when in this position, if a unit is added in the units wheel, it will effect a successive transfer to the highest order wheels, first setting all of the wheels to zero position, and then, due to the rigid connection between the transfer pawls I00a and I00b, the unit will be entered into the units accumulator pinion by way of the transfer mechanism.

From the foregoing, it will be apparent that due to the rigid connection between the transfer pawls I00 and I00b, there is a possibility of erroneous addition by the amount of "1" for each time the capacity of the machine is exceeded in a single series of adding cycles, because after the full capacity of the machine, namely 999,999,- 999.99, is reached, the addition of 1 will result in causing the accumulators to register 000,000,- 000.01, whereas, the indication should have been 000,000,000.00. However, this possibility of error is extremely remote and is of no more consequence than the possibility of error in the use of any adding or calculating machine whenever the capacity of the machine is exceeded.

Rsum

From the foregoing, it will appear that the machine of our invention is so constructed that a sub-total, a total, or a credit balance may be taken at any time, that is, during a cycle of the machine immediately following an add or subtract cycle. The factors which make this possible include the manner of resetting the transfer mechanism, whereby this is accomplished during the first 60 of rotation of the main shaft, and the utilization of a means for shifting the accumulator between its add and subtract positions which is operable prior to the commencement of, or at least during the first few degrees of. the operating cycle. v

The transfer mechanism, in which energy is stored and released to effect transfer operations with the movement of small low inertia parts, and the actuator operating means, whereby the resetting of the transfer mechanism is effected early in an operating cycle of the machine, contribute materially to the simplicity and speed of operation of the machine.

The means whereby the transfer mechanism is reset at the beginning of the operating cycle so that a blank stroke is unnecessary, is not claimed herein, but forms the subject matter of divisional application Serial No. 596,762, filed May 30, 1945.

While we have shOWn and described a particu lar embodiment of our invention, it will be understood by those skilled in the art that the invention may be embodied in various modified forms, and we therefore desire, by the following claims, to include within the scope of our invention, all such variations and modifications by which substantially the results of our invention may be obtained through the use of substantially the same or equivalent means.

We claim:

1. In an adding machine having numeral key controlled actuators, an accumulator having a plurality of pinions, said accumulator pinions being adapted to be actuated by said actuators in one direction to effect adding operations and to be actuated in the opposite direction to effect subtract operations, electromagnetic means for selectively shifting said accumulator pinions to condition them either for adding or for subtractingoperations, means for initiating an operating cycle of the machine, and means operated incidental to the initial movement of said last named means to energize said electromagnetic means.

2. In an adding machine having toothed actuators, accumulator pinions adapted when in one position to be driven in one direction and when in a second position to be driven in a reverse direction by movement of said actuators, electromagnetic means for shifting said accumulator pinions from one of said positions to the other, means for initiating an operating cycle of the machine, and a switch closed by said last named means upon the partial operation thereof, thereby to energize said electromagnetic means and shift said accumulator pinions prior to the commencement of the operating cycle.

3. In an adding machine having a plurality of toothed actuators, a plurality of accumulator pinions adapted to be engaged with and driven by said actuators respectively, a plurality of subtract pinions meshing with said accumulator pinions, means for shifting said accumulator and subtract pinions between positions in one of which the accumulator pinions are engageable with said actuators and in the other of which said subtract pinions are engageable with said actuators, an electromagnet for operating said last named means, and a manually operable switch-controlled circuit for energizing said electromagnetic means.

4. In an adding machine having a plurality of toothed actuators, a plurality of accumulator pinions adapted to be engaged with and driven by said actuators respectively, a plurality of subtract pinlons meshing with said accumulator pinions, means for shifting said accumulator and subtract pinions between positions in one of which the accumulator pinions are engageable with said actuators and in the other of which subtracting position, a pair or". solenoids, accumulator shifting means operated in one direction by one of said solenoids and in the opposite direction by the other solenoid, a key for initiating an adding operation and a key for initiating a subtract operation, a first pair of switches operated by said keys respectively, a second pair of switches connected respectively in series with said first named switches and said solenoids, and means operated by said accumulator shifting means to open the one of said second pair of switches which is in series with the solenoid which has been energized by the depression of one of said keys.

6. A calculating machine having a plurality of actuators, an add and subtract accumulator engageable with said actuators but normally disengaged therefrom, means for engaging and disengaging said accumulator and actuators, means for moving said accumulator from an add to a subtract position and vice versa while it is disengaged from said actuators, positive total-tak ing control means, negative total-taking control means, means operated incidental to the start of the manual operation oi said positive totaltaking control means to cause said accumulator moving means to move said accumulator from subtracting to adding position, and means operated incidental to the start of the manual operation of said negative total-taking control means to cause said accumulator moving means to move said accumulator from adding to subtracting position.

'7. A calculating machine having a plurality of actuators, an add and subtract accumulator engageable with said actuators but normally disengaged therefrom, means for engaging and disengaging said accumulator and actuators, means for moving said accumulator from an add to a subtract position and vice versa while it is disengaged from said actuators, positive total-talr ing control means, negative tOtaL-taking control means, and electromagnetic means energized in= cidental to the start of the manual operation of said positive total-taking control means to cause said accumulator moving means to move said accumulator from subtracting to adding position, and electromagnetic means energized incidental to the start of the manual operation of said negative total-taking control means to cause said accumulator moving means to move said accumulator from adding to subtracting position.

8. In a calculating machine having a key-set stop mechanism, actuators controlled thereby, and accumulator pinions operated by said actuators, said accumulator pinions occupying different positions in the performance of adding and subtracting operations, means for shifting said accumulator pinions from one position to mulator shiftable between adding position and the other, comprising a pair of opposed electromagnetic means, manually operable means for selectively energizing said electromagnetic means, and switch means operated by said accumulator shifting mechanism to deenergize and prevent reenergization of the electromagnetic means after the accumulator shifting mechanism has been operated by such electromagnetic means.

9. In a calculating machine, the combination of an accumulator, means for differentially actuating said accumulator, manually operable means for-selectively initiating an adding or subtracting cycle of operation of the machine, electromagnetic means operable upon energization substantially instantaneously relatively to shift said accumulator and said actuating means between add and subtract positions, and means controlled by said manually operable means to energize said electromagnetic means to cause relative shifting of said accumulator and said actuating means effectively prior to the commencement of a cycle of operation of the machine between positions in which the accumulator is effective to add or to subtract, depending upon the character of operation selected by said manually operable means.

10. A calculating machine having a plurality oi actuators, an add and subtract accumulator engageable with said actuators but normally disengaged therefrom, means for engaging and disengaging said accumulator and actuators, means for relatively moving said accumulator and said actuators between add and subtract positions while the accumulator is disengaged from said actuators, a credit balance key, means controlled by said key for conditioning the machine for the operation of taking a credit balance and for initiating such operation, and means operated by said key during the initial portion of the opera tive movement thereof to cause said accumulator moving means to move said accumulator from add to subtract position.

11. In a calculating machine having actuating means, an accumulator, and operation controlling keys, electromagnetic means for effecting relative shifting of said accumulator and actu ating means between add and subtract positions, and switch means operated by said operation controlling keys to energize said electromagnetic means and thereby cause relative shifting of said accumulator and actuating means in accordance with the operation to be performed, said shifting being accomplished prior to the effective commencement of the operating cycle oi the machine.

12. In a calculating machine having actuating means and an accumulator, electromagnetic means for relatively shifting the accumulator and the actuating means between add and subtract positions, switch and electric circuit means for energizing said electromagnetic means to cause relative shifting of said accumulator and actuating means to relative positions according with the operation to be performed, and control keys for determining the character of operation to be performed and for causing the operation of said switch means prior to the engagement of said accumulator with its actuating means.

THOMAS O. IVIEHAN. HUN .EER E. HOOE.

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