US1819066A - bernau - Google Patents

Description

Aug. 18,1931. F. w. BERNAU OW MINERAL KEY LOCKING IECHANISI 9 Sheets-Sheet 1 Filed Sept. 13, 1926 Aug. 18, 1931.

Filed Sept. 13, 1925 9 Sheets-Sheet 2 Aug. 18, 1931.

7 F. W. BERNAU OVERDHAFT NUMERAL KEY LOCKING MECHANISM 9 Sheets-Sheet 3 Filed Sept. 15, 1926 Aug. 18, 1931.

QKING IBCHANISI 9 Sheets-Sheet 4 Filed Sept. 115 1926 Aug. 18, 1931. w, BEQNAU 1,819,066

OVERDRIKQT RUIERAL KEY LOOKING IECBANISI Filed Sept 13, 1925 9 Sheets-Sheet 5 Aug. 18, 1931. F. w. BERNAU OVERDRAFT NUMERAL KEY LOCKING MECHANISM 9 Sheets-Sheet 7 Filed Sept. 13, 192

Aug. 18, 1931;

I P. w. BERNAU ovnqljm mam. m LOOKING momma Filed SQ pt iS, 1 92s 9' Sheets-Sheet 8 k2 w3uw mu g xuk $29k QR.

new Aug. 18,1931 M i 7 v 1,819,066

UNITED STA ES PATENT emcernannmcx w. as figer gimme. new mm, more: re mm m6 TYPEWRITEB m or mum, new mm. a conronarron or m when k ovamnnm m meme Application me seawater is, me. mm ll'o. 135,141.;

This invention relates to an overdreft ated by the accumulator to lock the numeral numeral key locking mechanism "for calcukeys ofthe keyboard and when an atmnpt lating machines: is made thereafter to depress the raised nu- In my Patent 1,508,267 September 9, 1924, meral keys for the purpose of further eddithere is set forth a total and subtmal key tion or subtraction, the locked condition of locking mechanism which is automatically said keys constitutes a signal, notifying the operated when an overdraft occurs in the operator of the overdraft condition.

accumulator, and in my Patent No. 1,731,701 It then becomes 11 w: 1 ry for the operator dated October 15, 1929 disclosure ismade to releasethe lockin means which have ren 0 of locking meansfor the starting bar or dered the numeral eys inoperative. This operating means of the machine. canbe accomplished by dep the add- ;'I'he,present invention has for. its object mg and starting her and causing the therovision of improved means operated machine to thite cycle of I automatically when an overdraftcondition trons, the adding into mom It exists in the accmnulator of a celculat cumuhtor e amount represented by the machine thereupon to lock the unite keysconstitutingtheovernumeral keys and to lock the pmvscusly dedraft. pressed keys which have caused the over- My Improvements are illustrated in condraft o that release of said keys mnnot be nectmn with so much of theEllis machine so had until e;- operatoireleases the locking as. will afford erlear understanding of the means. construction andmode of operation thereof, My numeral key locking mechanism me but reference into/fie bid to the Ellis Patbe used in conjunction with the total an entslios. 1,197,276,!1d 1308M, andtomy subtotal key overdraft locki mechanism Patent 1,508,267 fonillustration of those of my Patent N 0. 1,508,267, 0B,, which, 110W beeomewellbar overdraft locking mechanism; Patknow to the art, require no detail illustn 1 ent N 0. 1,731,701, or, in connectidnlgi Both tion' of said mechanisms, or, it may beamed on p In the accompan ing drawings: a calculatin machine where ofsaid' Figure 1,13 0 (Ltul rear elevation, the locking mec anisms are present. V When referring to a calc'ul p Fig. 2, is a similar view, the she chine, it is to be understood thatI ref-j been turned; erence to an adding, or subtracting nFigsB, is a section on line 8-3, Fig. 1; machine of any character because, While the is a section on line 4-4, 2; as present im rovements have been devifled ar- '5 mprises d t il ia f th 1tic ularly or usle i111 cilllnnectitgi with ,tlzef fig; d.%t isprintingcacuat gmac inensm 9 i s the pge g g to g l q No. 7, ingig fg etgmprmes detail views of the lock eptem 1916 an 0. 1,203,888 10mm Q 40 her 7, 1916, and other patents the m i mgfgfi gifif the iW operating shaft being in normal fgoizltion;

Ems type ii,gizfim"g,i Fit;: 7, is e view like in .2, but with eer- I rovements may be a I t atin machines without departing the t 0mm, bang princ ples'of the invention. to black the eontmlhnl .8

" In a calculating machine provided with QWP P my improvements, the operator maymntinue F 8- $31 View like}? 8- the "W to use the keyboard until an overdraft -or e g retm opq e P 9?" negative amount is represented on the acthe locking trigger remaining in position to cumulator. When an overdraft condition ocprevent restoration of the controlling curs, the mechanism is automatically oper- Fig. this: view showing tbe qckmg trigger in normal position, as when no overdraft exists in the machine;

Fig. 10, is a similar view, illustrating how the locking trigger is operated to prevent restoration of the controlling bar when an overdraft occurs.

Figs. 11 and 12 are, respectively, front and rear elevations of the keyboard section of the machine of the Ellis Patent No. 1,197,276 showing how my improvements co-operate therewith;

Fig. 13 is a side elevation of the numeral key latch and lock and the rack lock thereof;

Fig. 14 is a vertical center section of the adding and subtracting machine of the Ellis Patent 1,203,863, the parts being in normal position;

Fig. 15 is a detail elevation of the numeral key release mechanism thereof, the parts bemg normal for adding;

Fig. 16 is a detail view showing the means by which the numeral key release bar is operated;

Fig. 17 is an elevation of the left hand side of the Ellis machine as disclosed in the Bernau Patent No. 1,508,267, showing the subtracting key in depressed position, the mechanism for controlling the adding and subtracting accumulator, and the overdraft locks for the total and subtracting keys, the latter being in normal position;

Fig. 18 is a perspective skeleton view of the Ellis machine as illustrated in the Bernau Patent No. 1,508,267 the side frames being in dotted lines, showing the overdraft mechanism and operative connections to the locks for the total and sub-total keys, and the decimal slide, the parts being in normal position;

Fig. 19 is a partly sectional, partly elevational, detail view of the overdraft mechanism as set for carrying on a subtracting operation, before an overdraft has taken place; and

Fig. 20 is a similar view showing the positions of the parts after an overdraft has taken place.

Reference is to be had more particularly to Figs. 5 to 14 inclusive and 51 of the Ellis Patent 1,197,276, and the description in said patent relating thereto for a detailed disclosure of numeral keys and their latches and manner of operation for those parts of the numeral keyboard and its accessories which are not shown in detail in the accompanying drawings.

Reference is to be made to the disclosures of the Ellis Patent 1,203,863, for the details of the construction and mode of operation of the accumulator, and to my Patent No. 1,508,267, more particularly to Figs. 1, 8, 9, 10, 11, 12, and 13 for a complete disclosure of the overdraft mechanism which is automatically operated by the accumulator when an overdraft occurs.

.ing key stems of the The mechanisms shown and described in these patents and, more particularly, the mechanisms heretofore specifically identified by the reference to the views or figures thereof afford a clear understanding of how the present improvements for locking the numeral keys may be operated when an overdraft occurs and released by the operator after they have been locked.

Referring to Fig. 14, the machine has a rack R for each bank or row of numeral keys, mounted to slide on two slotted cross bars K and R The movement of each rack R backward and forward is limited for the purpose of addition and subtraction by the stops K secured to the vertical slidkeys, K K K etc. to K The key, K does not limit the travel of the rack, but permits it to go its full stroke which is limited by the downward projections at the ends of that part of R which slides in the groove in the bar K These stops, K are so arranged that they engage steps on the upper edge of the rack R and these steps and the stops, K are arranged vernier fashion so that from the first step to the first stop, K on the key stem K, the rack R could move a distance of one tooth, while stop K on the second key K would permit the rack R to move a distance of two teeth and the stop K on the key stem of K would permit the rack to move a distance of three teeth, etc., up to K, which serves the purpose of unlocking the rack R, by releasing the rack lock 68, and permitting the rack, R to move its full travel or nine teeth.

The rack R is moved in a rearward direction by means of the springs, R which are connected at their rear ends to a bar, R extending between the side members of a bail, 45*, which bail is secured to the shaft R and rotates with it. Mounted on the shaft R are a series of hell cranks,

R, having three projecting arms, one projecting forward for the purpose of operating the 0 printing triggers, P, the other arm extending rearwardly for the purpose of connecting to the link P which serves to rotate the type sector P and if the bell crank, R" is rotated about the shaft R the connecting link P will cause the type sector P to rotate about its center and bring the desired type to the printing line. The third arm from the bell crank, R extends in a downward direction and carries a pin R which engages a vertical 'slot in the lower side of the rack, B. so that when the rack R moves forward and backward it communicates this motion to the bell crank B through the pin R and when the bail 45 is moved to rotate toward the rear or right, in Fig. 14, the spring R which connects the bar R and the bell crank It, tends to move the'rack R in a rearward direction until this travel is checked by one of the side of the order plate 60K, rests in small stops K or some other obstruction to its movement.

The segmental rack, B", mounted on the lower extending arm of the bell crank, R is for the purpose of obtaining forced alinement of the type on the sector I? and this alinement segment R is secured firmlyrto the lower arm of the bell crank R. he alinement of the type throu h the segment R is brought about throng the insertion of the blade R" mounted onthe forward side of the alining frame R which in turn is mounted upon the shaft R.

The handle, or the motor drive of the machine is adapted to cause rotation of shafts 01, R1 and R2, as explained in Ellis No.

Referring to Figs. 11, 12, 13, underneath the keyboard K50, there is a a series of vertical plates 60K, which tare called order plates. These are secured to the plates pass down on the left-hand side of the order plates K, and are held in contact therewith by means of hexagon-headed rivets K23, which as through vertical slots in the plate 601?. These rivets m, form the stops for the rack R50, and serveas a means of guiding the keystems K51, to K59, in a vertical direction. Above the rivet K23, opposite each of the keystems K51, to K59, there'is an irregular shaped hole in the order plate 60K. Through the u per and of this hole, there is inserted a at washer 59K, which has arectan lar slot through it, through which the rgstem This washer 59K, is held xedly m the order plate 60K, and 'ust below it there is a loose washer K99, o felt, mounted on the keystem, and below this felt washer K99, is a third washer 56K, which is to the keystem and moves with it. Between the washer 56K, and the bottom of the hole' aforesaid, is a compression-coil spring K80,

the lowerend of which rests against the edge of the hole in the order plate 60K, and the upper end presses against the washer 56K, mounted on the keystem. when a keystem is de ressed, it carries down with it the washer 99, and comp as the ring K80, and when the keystem is rel the spring K80, returns it to its normal position. The order plates 60K are further maintained in position by two bars extending horizontally across their front and rearedges, which bars are marked 61K, and 62K. These bars are notched in asuitable fashion to enga e each of the order plates 60K, and

is ada slots in the cross bar K3, extendi between the side frames of the machine. cross bars 61K, and 62K, serve also as a means of supporting the pivots K1, of the latches 52K}; whch holddthe keyatazlms litigate K59, int eir e resse 'tion nrmg' ration of th? machin l These latches a r arranged so that there is one toeach column of nine 'ke stems, and they swing sidewise from the Swinging about the same pivot 1, are the keystcm the [80k 106k 68K, and :w I control the keystem latch 52 lost 53K,andasringK88,eont :therack lock 68K. e locks 53K, are'olchprovidled in their; rear Iends with a an across ar ,issupported a each of these locks 58K.

e shiftable bar 65K is provided with a series of notches A adapted to cooperate with the luck latches 53K m a manner which is clearly shown in F 11 and 12.

The operation of e keystem, its latch 52K, its lock 53K and the rack lock 63K is set forth in detail ,in Ellis Patent No. 1,197,276.

In Figures 1, 3, and 14, the shaft 01 is shown in normal position, the position ap- Bearing in Fig. 3 of patent 1,121,270 and ig. 2 of Patent 1,203,863. In that position, the abutment of the restoring pin 2 against the roller 3 of the crank lever 63K causes the shiftable bar 65K to be moved toward the right, Fig. 1. It will be understood that Fig. 1 is a view looking toward the rear of the numeral key latching means, coing to F' 12 which is taken from the Ellis Patent the im roved cam lever 63K, 168K.

The olding of the parts in the position locks 53K. There is also mounted on the ivot kg,

shown in Figs. 1 and 3 permits the lock latch 4, under the tension of spring 4, to enter the notch X which is rovided in the extreme eng lpf ghe bar 62K be e rams piece appears at r ieces of the su porting frame being omitted or the sake o clear-noes.

Normally, the lock latches 53K are held out of the downward path of travel of the studs K25 by the action of the notches A.

When the machine is operated, the shaft 01 the restoring pin 2 from the position of igs. 1 and 8 to that of Figs. 2 and 4. 2 and 4 re resent the extreme extent o turning of a shaft 01 and the actionsofthe parts when movingfrom the normal position of Fi 1 and 3.

The arm 50" which 18 secured to shaft 01 is utilized for "the p of actuating the latch 4. To that end are is carried by the arm an ad'ustable eccentric roller 080 which to wipe inst the latch 4 to shift t e latch from locking position of Figs. 1 and 3 to the unlocking position of Figs. 2 and 4 when the shaft ()1 is turned from normal position to the position appearing in Fig. 4. The first approximate ten degrees of the movementof the "shaft 01 brings about a movement of the key latches 53K to the position'shown in Fig.2, thereby preventing the key stems'KSl from being depressed.

Illustration is given only in Figs. 1' and 2 oftwo orders of key stems. the others being omitted for the sake of clearness, as they appear in Fi s. 11 and 12'.

In Fig. 2 the right-hand key stem K51 is held in' its depressed position by its latch plate 52K. Both of the lock-latches 53K have moved in a counterclockwise direction. allowing the bent parts of the latches to rest against the sides of the key stems. By reason of the latching action, it will be obvious thatno stem which has not already been'depressed can be depressed once'the bar 65K has been'shifted to the position s'hown'in Fig. 2 because the lateral parts of the key latcheswill lie directly under the studs or lugs K25 of 'those 'key stems which have-not been depressed. Y

The various shutter latches 53K for the banks of numeralkeys are operated the release bar 66K, Figs 11; 12,16 which engages a' 'bell crank'lever L ,'whioh in turn is operated by a sliding bar L extending forwardly and rearwardly of the machine,

Figs. 11, 15, 16. In additionthe numeral therolle'r D On'the' return stroke of the handle O? and the shaft"O,the roller '1) engagingithe hook L which'is pivoted on the slidingba'r L draws the sliding bar L towardlthe rear of the machine" and so o'peratesthef'crank L and the transverse bar 66 releasing the numeral keys." The upward extending arm of thehook L ongages a stud L at a "suitable' time to release the hook L from the roller D" and permits the sliding bar L and itsfconnections' to the transverse slidingbar 66 to resume theirnorm'al position. In the efvent of an overdraft, the keys'which have been depressed are released from the latch. 52K

at C (Fig. 2) "when the machine i's*p'ut.

' through its cycle'of operations, but these keys are prevented fromrising b the engagement ,of'latch 53K with 'stu K25,*as shown in said figure and thus remain in operative-position. 7 r The release of-the numeral keys when subtraction takes place is done in the'same time and by the same mechanism that releases the numeral keys' in addition; r

7 \Vhen a-total or sub-total'is to be taken it is necessaryto r'elease the numeral keys during the first fifteen degrees of the forward stroke of the handle 0 and this is accomplished in the following manner. The total and sub-total keys 'K abut at their lower end against a diagonally sliding piece L"- which'sliding piece has a turned over lip near itsrearupper edge which engagesa stud L on the lower edge' of the irregular shaped piece L. TlllS pieceL 'is pivoted to the lower end of the latch L for the repeat key'K and is held in its upper position by a suitable spring. A

second stud L iirtlie lower edge of the piece'L comes underneath a second hook L pivoted on a downward extension from the piece L and the hook L and the hook and carries down the'piece -L which permits the spring to raisethe hook L until it comes'into engagement with a roller D on-the lower end of a pivoted c'ar'n'"D and thiscam D is in contact with a roller D mounted on theplate D securedtd'the shaft 0 r When the parts have been thusarranged, the initial movement of shaft 01 will cause roller-D32 toswing the cam D63 to the left and-so. movethe hook L64 -'and the piece with the overdraftautomatic locking mechanism set forth in myPatent No. 1,508,267 the action of said overdraft locking mechanism will be clear by reference to Patent No. 1; 508,267, articularly to FigsJB, 9, 10,11, 12

and 13t ereof,xand to F'gs.: 17, 18, 19 and .20 hereof. I

F orthe purpose of locking the bar 6 5K in positionwhere the lock-latches'53K will pregvent the key stemsK51 from being depressed as shown, forinstance, intFigs. 2,8 and 10, there is provided a locking trigger 10 which is pivotallymounted in any suitable manner as,'for instance, atlO on a part of a frame 'rF." This trigger is normally in the position shown in Fig; 9 but-when the overdraft mechanism of. the'accumulator comes into 'action'on' the occurrence of an overdraft in the' machine, the bar or link 69L is shifted brings about a position of the trigger as shown in Figs. 8 and 10, whereupon the trigger is disposed so that its bent end constitutes a etc or abutment for the end of the shiftable Bar 65K and prevents said bar from returning to the normal position shown in Fig. 1 and looks it in the positionshown in Fig. 2 where it is impossible for the latch 4 to enter the slot X. When thwbar 65K is in this blocked position, the key stem latches 53K are held so thatthehey stems are locked against depression and "hence the operator is given a signal that there is an overdraft in the accumulator. I

i To take care of this condition there is provided a secondary or safety pawl 163K w ich is pivoted at 13 to the lever 63K and is connected to it by a spring 15. The lever 63K and the pawl 163K collectively cooperate with a pin 14 carried b the barfifiK. The spring 15 normally enab es the parts 63K and 163K to swing as a unit on the 14 but this spring permits yielding as shown in Fig. 8 when the shifting of the by 65K is blocked by the trigger 10, so that there will be no breakage or interference when the rock shaft 01 turns while the in the bar 65K. I a

%he crank lever and safety part! a pear in detail in Fig. 5, and the trigger is. s own in detail in Fig. 5A.. I

To'restore the trigger 10 to normal position and to maintain it normally in the position shown in Fig. 9, there is provided a trigger 10 is blockspririg 10". Y

Normall the parts are in the. position shown in i s. 1 and 3 and thelcey stems K51 may be depressed in the difierent banks of the keyboard and the machine operated in the usual manner as will be clear from the Ellis Patents 1,197 .276 and 1,203,863 and i the foregoing disclosure.

The adding and subtracting accumulators of Ellis Patent No. 1,203,863 appear in Fig. 14 and the overdraft mechanism therefor 18 shown in Figs. 18, 19, 20 in accordance with my Patent N 0. 1,508,267. The keys and means setting the respective accumulators for subtraction and for the taki of totals and sub-totals are shown in F ig i f.

Reference is to be had to Patents L203,863 and 1,508,267 for a full disclosure of the accumulators and the manner in which they maybe conditioned for addition, subtraction or the taking of a total or sub-total,-and their cooperation with the racks the parts and mechanisms being numbered to correspond with similar parts and5mechanisms in said patents.

Particular description, however, will now be given of the overdraft mechanism of my Patent N o.-1,508,267 in order thatithe relationshi of the present improved numeral key 100 ring mechanism thereto will fire clear.

ferring first to Figs. 19 and "20, the

former shows theshift bar N90 set to cans:

pressed as. shown in 17, the shift bar N90 is turned to the P0816011. shown in Fig.

19 to block the adding cam hook N and free the subtractin cam hook N56 for use.

A link 64L, Fig. 1 which is shifted when subtracting key K67 is depressed as in said ggure, effects this setting of the shift bar Referringnow to Figs. 18, 19, 20.

Pivoted to the order plate 53N of the highest order by a stud N16, is an overdraft lock latch 66N. A spring 8-1N which cooperates with the overdraft lock latch 66N andv the order plate 53N, tends to swi the overdraft lock latch so that its oint willmove in aclockwise direction. his movement is prevented when the shift bar N90 is set for addition as shown in Fig. 14, there being a rounded projection X on the overdraft lock latch which is nessed downwardly by the shift bar N90 when the latter is set for addition. Con uently when the accumulator is set for addition as shown in Fig. 14, the pointed and X performs no function.

However, when the shift bar N90 is set forsubtraction, as will be the case when the subtracting key K67 is do and the machine 0 rated, the turnln of the shift bar N90 mm the position a own in Fig. 14 to the position shown in Fig. 19, relieves the pressure against the rejection X" and thereupon the sprin 81 turns the overdraftlock latch 6614 so that the int X comes against the rear end of the sua racting pawl or hook N62 which arrests it as shown in Fig. 19. The turning of the wheel N50 of the highest order either directly .by rack v R50 or b carrying, resulting in an accumulation o subtracted items causes the cam N 56 to engage the tip of the. sub pawl or book N62 by moving from the pos1 tion shown: in Fig. 19 to that shown in 20 thus depressing the left hand end of the subtracting pawl and elevating the right hand end thereof. This action results in the release of int X so that the sp 81N immedia y swings the overdraft latch to the position shown in F 20 whereupon it enga as the rear end of t subtracting pawl or 1: N62 and holds it in that position until released as hereinafter described. Y

To prevent the balance or total key K63 for the 11 per accumulator and the sub-total or total posits key K64 from being operated when the upper accumulator represents an overdrafted condition, means are provided for automatically locking these keys when this condition prevails, said means being operated from the overdraft shaft N6.

Referring to Figs. 17, 18, there is provided on the left hand end of the shaft N6 a crank N68". Pivoted on the screws L19L of the latches 56L and L56 for the keys K64 and K63, are locks 67 L and 68L whose lower ends are positioned so that they can be engaged with notches 167L in the stems of keys K63, K64, when said keys are in elevated or normal osition. For the purpose of causing the 100 s 67L, 68L, to engage the notches 167L or to be released therefrom by the turning of overdraft shaft N6, there is rovided an operative connection comprising a link 69L pivoted to the crank N68 and a link or slide bar 66L pivotally connected to link 69L at L24L. The link 66L is pivoted to studs L18L on the upper ends of the locks 67L, 68L. Near the rear end of the slide bar 66L there is a slotted part 66L which slides on a pin or stud L20L on the side frame of the machine, thereby guiding and suspending the bar 66L. Normally the crank N68 is in the position shown in Figs. 17 and 18 even when the subtracting key K67 is depressed.

When an overdraft condition exists in the 11 per accumulator which causes the overdraft latch 66N to move to the position shown in Fig. 19, the rocking of the shaft N6 turns the crank N68 backwardly and thereupon the locks 67L, 68L, are swung so that their lower ends engage the notches 167L. This results in locking the keys K63 and K64 so that the operator cannot take a total or sub-total and a signal is thus given, indicating to the operator that the account is overdrawn and necessitating the manual operation of the decimal slide P67 or such other means as may be employed to unlock the keys K63, K64.

To release the total and sub-total keys, the hand-operated decimal slide P67 or some other suitable means is provided, said device bein adapted, when operated, to shift the link 73 thereby to rock the crank E60 carried by shaft 11 which rocks the arm C which, in turn, rocks crank N68, shifting the link 69L which releases the latches 67L and 68L from the total and sub-total keys K63, K64.

\Vhen an overdraft has taken place in the accumulator, the action of the overdraft mechanism, which will be clear from the foregoing description and the disclosures of my Patent 1,508,267, causes the shifting of the link 69L from the position shown in Fig. 9 to that shown in Figs. 8 and 10, po-

sitioning the trigger 10 in the extreme for-' ward position appearing in Figs. 7 and 10.

While the O1 shaft returns to normal position, the locking trigger 10 remains in the position shown in Figs. 8 and 10 where it is directly in the path of the bar 65K and prevents said bar from returning to normal position. The pressure of the pin 2 againstthe roller 3, as the shaft 01 returns to normal position forces the lever 63K to the position shown but as the spring 15 yields and as there is nopositive connection between the lever 63K and the pin 14, there is no interference with the locking action of the locking trigger 10 and the retention of the lock-latches 53K in the locked position shown in Fig. 2.

Finding that the numeral keys cannot be depressed, the operator thereby is given a signal which indicates to him that an overdraft exists in the accumulator.

By referring to my Patent No. 1,508,267 issued September 9, 1924 on overdraft key locking and indicating mechanism on page 9, beginning on line 28, I mention that when an overdraft has taken place no further addition should be permitted in the accumulator. In the mechanism of Patent No. 1,508,267, in order to prevent further addition after an overdraft has taken place, a hook 69L is arranged on the link 69L, that embraces the stud D21 and renders the credit accumulator inoperative insofar as addition is concerned.

With the overdraft key lock mechanism as set forth in my Patent No. 1,508,267, it is desirable to prevent further addition after an overdraft has taken place. On the contrary, with the mechanism of my present application for overdraft key locking mechanism it is not desirable to prevent addition after an overdraft has taken place. Therefore the hook 69L on the link 69L of my Patent No. 1,508,267 is omitted, thus permitting the accumulator to go through its operation as of addition, but as the numeral keys are locked against their depression no addition is actually performed.

As set forth heretofore, in connection with my present improvements, when an overdraft has taken place in the accumulator, the operators attention is called to this condition by the inability to depress any of the numeral keys, either for the purpose of addition or subtraction. The adding key that controls the addition for the credit accumulator is now depressed by the operator and the machine is operated, thereby: adding back the exact amount which has caused the overdraft.

Should the mechanism be provided with a key to manually release the depressed numeral keys, the credit accumulator will go falsely through its cycle of addition.

It is to be understood that when the credit accumulator is set for addition, the shift bar N-90 is set as shown in Fig. 9 of my Patent, No. 1,508,267, the abutment of the shift bar N-90 against the overdraft lock latch 66--N causing the extreme lower end X1 of the said lock latch 66--N to be held away from the backward side of tho subtracting pawl N-62.

When the accumulator is set to 'perform subtraction, the shift bar N--90 has been 1 caused to move to assume the position shown in Fig. 19 hereof, thus allowin the overdraft lock latch to stop against t e subtracting pawl. Inasmuch as the overdraft lock latch 66N is under the tension of the sprin 81-N as explained in in said patent, sai overdraft lock latch 66- the position shown in Fig. 20 hereof after can overdraft has taken place, and thro hits train of mechanism causes the balanc iey or keys to become locked. However, in thepresent application I prefer to use this same initial movement of the lock latch 66-N}to lock the numeral keys as hereinbefore e lained. When the shift bar N--9O is mo it t eth subtracting position as shown in Fig. 19 hereof, it is latched in this. sitionl by the latch -N illustrated in Fi s. 3 and 5 of my Patent No. 1,471,770, Octo r 23,1923.

Assuming that an overdraft has taken place and the operators attention is called to this fact by being unable to continue with addition or subtraction of items, for the reason that the numeral keys are locked against depression, the credit-add key is depressed and the machine is operated; While the machine is going through its cycle the latch 70N is released from the path of the shift bar N- b the restoring N49 (Fig. 2, Patent 0. 1,471,770) and the shift bar is permitted to amume its normal position as shown in Fig. 14 hereofi. The shift bar N--90 forms an abutment the overdraft lock latch 66-N and' f'causes the trigger 10 of the present application to assume its normal position as shown it! Figs. 7 and 9, thereby removing the lock-latch from the path of the lock stud. K25'in the numeral key stem K-51. I

What I claim is:

1. In a calculating machine, the combin-ation with an accumulator adapted foreither addition or subtraction, of settable numeral keys on which the numbers or amounts which are to be added into, or subtracted Thom, the accumulator may be manually set u means adapted to automatically locking numeral keys which remain undo n to prevent them from being 0 re to as up a number after an ove raft has occurred in the accumulator, and for releasing said locking means.

2. In a calculating machine, the combination with an accumulator adapted for hither addition or subtraction, of settablo n keys on which the numbers or amounts yhich are to be added into, or subtracted from, the accumulator may be manually set up, means b 0 rations ads operated b the accumulator adapted to automation y efl'ect locking of the numeral keys which-remain undepressed to prevent them from be ngoperated tcset up a after; an ,overdraft?- has occurred in the accumulator,

coking a 3. In a calculating machine, the combination wit an accumulatoradapted for either addition or subtraction, of numeral he on which the figures or amounts to be added into, or subtracted out of, the accumulator may be manually set up, locking means which, in the normal use of the numeral keys, retain the he in set position after said numeral keys ave been manually set to enable the amountsor figures represented thereby to be entered into said accumulator, and overdraft mechanism automatically operated when an overdraft occurs in the accumulator, said overdraft mechanism bemg adapteckwhen thus automatically operated to mtarfere with the normal action of the locking means aforesaid, thereb to pre vent such numeral he s as have been set from being automati y restored and those numeral keys which have not been set from bemghmanually operated.

4. a calculat' machine, the combination with the numeral keys thereof on which numbers or amounts may be manually set up, of latches for holdi the numeral keys in set tion when said keys have been man iset, means normally operated when the mac me 18 going through its cycle of ted to automatically release t e aforesaid atches so that the numeral keyswillbefreedfornmtuaman accumulator-adapted for either addition or subtraction, overdraft v new ads for automatic operation by said accumum when an orerdraft occurs, and means operrated by overdraft mechanism adapted for ring with the normal 0 of'the latches, thereby to prevent such numeralhe as have been set from being automat! y restored and those numeral keys which have not been set from being mannally operated, without interfering with an idle operation of the machine.

5. In a calculating machine, the combination with the numeral keys thereof, of latches for holding the muneral keys in set position when said keys have been set, means operated when the machine is going through its cycle of operations adapted to release the aforesaid latches, an accumulator, overdraft mechanism operated by said accumulator, a shiftcble bar which determines us whether the latches shall be arranged to permit depression of the numeral keys, or, to prevent depon of said keys, and a locking trigger which is set by the action oftheoverdrafttolocksaidbar II.

and means for releasing saidw Ill and maintain the latches in their latched position when an ovedraf-t occurs in the accumulator, thereby to prevent depression of any numeral keys which have not been set.

In testimony whereof I afllx my signature.

FREDERICK W. BERNAU.

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