US1463155A - District of cqium - Google Patents

Description

July 31, 1923.v

F. K. DAVHS ET AL.

ACOMBINED TYPEWRITING AND COMPUTING MACHNE 5 Sheds-Sheet l Filed Nov. 2l, 1921 ZM M @M July 31, 1923. 1,463,155

F. K. DAVIS ET AL COMBINED TYPEWRITING AND COMPUTING 4MACHINE Filed NOV. 2l 1921 3 Sheets-Sheet 2 v iisg.'

July 31, 1923.

F. K. DAVIS ET AL COMBINED TYPEWRITING AND COMPUTING MACHINE Filed Nov. 21 1921 3 Sheets-Sheet 5 time ,FRANK K. DVES AND CHARLES (C. TAYLR, @F WEHNGTN, DSTRICT @E CLTUM= NEW?" YORK,

CMINED TYEEW'RLNG AND @@MU'TNG- LACHINE.

Application nlcd November To all 'whom t may concern:

Be it known that we, Freinr, l. Davis and CHARLES C. TAYr/on, both citizens et the United States, and residing in the city of Washington, District of Columbia, have invented certain new and useiul llmprovements in Combined Typewriting and Cornputing Machines, of which the following is a specification.

This invention relates to combined writing and computing` machines, settable 'l he two latch members or links are c for addition or subtraction, and more particularly to state controlling means effective during the return orbaclrward movement or the carriage, and is herein illustrated as applied to a bookkeepingT machine of the Underwood-Hanson type.

ln a bookkeeping machine of the type referred to, the computing` mechanism, which is normally set for addition, may be set for subtraction byV the rearward movement of a subtraction bar extending tore and att. The rearward movement of the subtraction bar is usually effected by a spring, and, when the machine is set for addition, the subtraction bar is held in its :forward position by a hook or catch engaging in a notch in the bar. The release o the subtraction bar from the catch may be elected by a subtraction key connected to the catch so as to move therewith in both directions.

.The machine is motor-operated and both the motor-operation and subtraction-setting may be efected by spring-urged levers having their rear ends normally engaged by the outer ends ot transverse latch members or links which restrain the respective levers `from operating under the action ot their springs. rlllhe lever for releasing the snbtraction bar has a one-way connection with the catch which normally restrains the ed by suitable trains of mechanism 'i' vers pivoted at the rear o ma that tappets projecting upw-irdly may be engaged respectively by @do subtraction stops ci' the usual tioned on the carriage in accorti/ance computing Zones determined by the Each ot the tappets is beveled n the si l' gagged by the stops during movement of the earring on the corresponding lem? yield with reference t- 2l, '5.921. Serial No. 536,625.

by the stops in such movement, but, upon engagement by astop moving inthe opposite direction, will swing on, itspivot and allow the passage ot the stop without operation ot the corresponding lever. Actuation of either one of 'these levers by a suitable stop will cause respectively either actuation ot the .general operator by the motor or subtraction-setting by means of the subtraction bar.

such machines, controlling ot the state tor addition or subtraction is etlected automatically in the letter-feeding movement of the carriage, but no such control is eiiected during the return movement thereof. Actuation of the general operator by the motor will reset the machine to addition, it set for subtraction, and it has been proposed to modify the tappet on the motor-trip lever and its connection with the latter, so that the motor-trip lever will be actuated by the stop moving in either direction, whereby, upon backing the carriage in a computing zone, the

motor-trip will be actuated and the machine,

it set tor subtraction, will be reset for addition. According to this arrangement, the motor is actuated every time the carriage is backed into a computing zone.

The main object ot the present invention is to provide means whereby, if the carriage is backed into a computing zone when the machine is set 'for subtraction, the motortrip will be actuated and the machine reset to addition, but, in case the machine is set for addition, the motor-trip will not be ac-` Pta Y in lever, and, upon movement oie the iinl; iny i ine'dective position permit subtree"*onn setting, the hoolr will passinto i i the linll it trie trip lever connected therewith in actuated position.

The hook or latch has a movable mounting which is normally maintained by the general operator in position to enable the latch to enter the notch and to co-operate with the link or latch to hold it against movement. Upon forward movement of the general operator, the mounting will, however, be shifted so as to move the hook or latch away from the link, thereby permitting vthe link and the subtraction-trip lever to return to their normal positions.d lVhen, therefore, the machine has been set for subtraction, the tappet on the motor-trip lever will be locked against yielding when engaged by the stop in a backward or return movement of the carriage, and, upon backing the carriage into a computing zone, the motor will be tripped and the general operator actuated, the subtraction-trip lever then being released and permitted to return to its normal position, and consequently the tappet on the motor-trip lever will be released.

If the subtraction-setting is eected by the subtraction key, provision must be made of means to aetuate the subtraction-trip lever. so as to lock the tappet on the motortrip lever toenable the machine to be restored to addition when backed into a computing zone. To this end, provision may be made of means actuated by the subtraction bar in its rearward movement, whereby the link or latch connected with the subtractiontrip lever will be moved to ineffective position by the subtraction-setting bar, and then released, the link being maintained in this ineffective position by the hook or latch arranged to, engage in the notch therein, as in the case of automatic setting for subtraction. Upon backing the carriage into a computing zone, the motor-triplever will be actuated and the general operator will effect re-setting of the machine for addition in the usual manner.

Other features and advantages will hereinafter appear.

In the accompanying drawings,

Figure 1 is a diagrammatic side view, partly in section, of an Underwood-Hanson machine with the invention applied thereto.

Figure 2 is a skeleton perspective view of the arts embodying the invention.

Figure 3 is a view of the subtraction-trip and motor-trip levers, part of the subtraction-trip lever being broken away to show the means forA locking the tappet on the motor-trip lever against pivotal movement with respect thereto.

Figure 4 is a top view of the parts shown in Figure 3.

Figure 5 is a rear view of certain of the parts, showing them in normal position.

Fi ure 6 is a view similar to Figure 5, but s rowing the position of the parts after position b actuation of the subtraction-trip lever by a subtraction-stop.

Figure 7 is a. detail view, partly in section, showing the link, connected with the subtraction-trip lever, and means for control-` ling the same, the parts being in their no1'- mal positions.

Figure 8 is a view showing the latch, or hook, which is normally held in retracted the transverse link, positioned in the notc of the link and holding the latter in ineffective position.

Figure 9 is a detail view similar to Figure 8, but showing the parts in the position assumed when the general o erator moves forward` the transverse link eing released from the latch or hook.

Figure 10 is a detail view'showing the manner in which the motor-trip lever is actuated upon backing the carriage into a computing zone when the tappet on said lever is locked against pivotal movement thereon as a result of the previous actuation of the subtraction-trip lever.

Depression of numeral-keys 10 and alphabet-keys 11 will actuate key-levers 12and bell-cranks 13 to swing type-bars 14.- upwardly and rearwardly' to canse types 15 thereon to co-operate with a platen 16 and eilect printing on work-sheets carried by the latter. The platen 16 is rotatably mounted in a carriage 17, supported on front and rear rails 18 and 19, respectively` and urged in the letter-feeding direction by suitable means (not shown).

The movement of the carriage under the action of its urging means is controlled by means of a rack 20, connected with the carriage and meshing with a pinion 21, having the usual one-way connection with an escapement-wheel 22. As any one of the type-bars approaches the end of its printing stroke. a shoulder 23 thereon will engage a universal bar 24 and actuate the usual fast and loose dogs 25 and 26, respectively` thereby permitting movement of the escapement-wheel Q2, and, consequently, a letter-space movement of the carriage 17.

Provisin is made at the rear of the carriage of a rod 27, on which one or more selectors Q8 may be loosely pivoted` so as to be slidable therealong, and of a notched bar 29, with which a tooth 30 on each selector co-ope'rates, so as to hold the selector in adjusted position. Each selector 28 is held in raised or effective position while passing through a computing Zone by means ot' a frusto-conical roller 31 thereon engaging a cylindrical roller 32, having tapered ends. thereby causing a tappet or dog 33 on the selector to engage seriatim the forward ends of jacks 34.-, pivote-d at 35 in ay housingr 3G. The movement of the jacks 34 is transmitted, by means of thrust-links 37. levers 38. transposition-linkages 39 and bell-cranks 40.

lill) to pins or lugs 41 on pin-bars or denominational members 42, thereby advancing the latter seriatim, to enable digits to be indexed thereon, by depressing index-pins 43 carried thereby.

For the purpose of setting the index-pins 43, each of the numeral-keys from l to 9, inclusive, is provided with a pendant or thrust-link 44, which, upon depression, engages an arm 45 on a corresponding shaft 46 of a set corresponding in number to the links 44, to actuateJ corresponding linkage and causea pin-setting bar 47 `thereof to engage and depress a pin, of the same value as the numeral-key depressed, on a pin-bar which has been advanced from its normal position, to bring the pins thereon in alignment with the pin-setting bars 47. This action is repeated each time-a digit is indexed in a different denomination.

Then the indexing of the number has been completed, the generaloperator 48 may be actuated, to cause the bar 49, thereon to engage the depressed index-,pins 43 and advance the pin-bars 42, in accordance with the setting of the index-pins 43, therebactuating dial-wheels 50, suitably geare to said bars 42, thedial-wheels 50` fomin part of a register, from which the results o the computations may be read through a sight-openlng 51 in the casing 52 of the computing mechanism. c

Manual. actuation of the general operator may be effected by means of a handle 53, fixed on a shaft 54, the movement of the latter being transmitted by means of toothed sectors 55, fixed thereon, and'pinions 56 to racks 57, forming parts of the general operator 48. The general operator may also be operated by motor-actuated means which may be, in general, the same as disclosed in the patent to Wood, No. 1,299,646, dated April 8, 1919. To throw the motor-actuated means into operation, apin 58 may be raised vby means of a lever 59, pivoted at 60 and normally held by a spring (notshown) in position to maintain the pin 58 in its normal depressed position. Operation of the lever 59, to raise the pin 58 to ineffective posltion, thereby releasing the rotatable clutch-member 61, may be effected by' depressing- 'the outer end of lever 59 by means of a motorstarting slide 62.

The machine may be set for subtraction by l means of a subtraction-key 63, connected by means of a link 64 with an arm 65, fixed on a transverse shaft 66, which carries 'al hook or latch-member 67, normally engaging a shoulder 68 at the forward endof a notch 69 in the usual subtraction-bar 70. Upon operating the subtraction-key 63, the latch member 67 will be moved to ineffective position, and the subtraction-bar 70 will be moved rearwardly by its spring 70% thereby setting the machine for subtraction. fr pin 71 on the-bar 70 extends into a slot in one arm 72 of a bell-crank, the other arm 73 of which is connected by a pin-and-slot connection 74 with an arm 75, fixed on a plate 76, pivoted at its upper edge and having its lower edge projecting into slots 77 in shafts 46.

Upon the rearward movement of the subtraction-bar 7Q, the plate 76 will be turned in a clockwisedirection, and the shafts 46 moved forwardly, to change the connections betweenI the shafts and the pin-setting linkages in the usual manner. The rearward movement of the subtraction-bar 70 will also effect setting of the 9 pins in the usual manner. After the completion of the indexing of a number, when the mechanism is set for subtraction, the pin-bars may be advanced by the general operator, and subtraction effected by the complemental method. 1n the forward movement of the general operator, the bar 49 thereof will engage a. lug 78 on the subtraction-bar 70 and advance the same to a position to enable the hook or latch-member 67 to engage the shoulder 68 and retain the subtraction-bar in its forward position.

lln order to effect automatic control of the motor and the subtraction-setting means, use is made of' addition-stops 80 and subtractionstops 81, settable on a notched bar 79 supported on the rear of the carriage. Each stop of the two kinds is made up of two parallel spaced plates, and, as here shown, the right-hand plate, looking from the front of the machine, 1s provided witha downward extension 82 toco-operate with a usual tabulator-plunger or counter-stop 83. The downward extension 82 of each of the stops is also utilized in tripping the motor, and, in passing out of a computing zone in a letter-feed direction, engages the beveled side 84 of a dog or tappet 85 pivotally mounted on a motor-trip lever 86. When engaged by the downward extension 82 as the carriage moves in a letter-feed dirertion, the dog 85 is held against movement on its pivot by engagement with a stop or abutment 87 on I the lever and the latter is operated. Upon engagement of the left-hand beveled face 88 of the dog 85 in the return movement of the carriage, the dog 85 will turn idly about its pivot 89, against the action of a spring 90, toan ineffective position.

As the downward extension 82 of the stop engages the beveled side 84, the tappet 85 will be forced downwardly and the lever 86 turned about its pivot 91, thereby actuating, by means of a link 92, a bail 93 mounted on a stud or stub-shaft 94 near the base of the machine. This movement of the bail 93 is effected against the resistance of a spring 95, and causes the drawing to the right, looking from the front of the machine, of a link 96, thereby enabling the upward movement,

under the influence of a spring, not shown, of the rear arm 97 of a lever 98 pivoted at 99. Upon such upward movement of the arm 97, the other arm 100 thereof will be swung downwardly, and, by engagement with a pin or stud l101 on the slide 62, will actuate the lever 59 and lift the pin 58 to render the motor effective to actuate the general operator 4.8. Upon the forward movement of the general operator, a cam-surface 102 on the side adjacent the lever 98 will engage an off-set finger 103 on the forward arm 100 of the lever, and swing the latter back to its normal position to enable it to be locked in its 'position by the link 96, which is guided near its outer end by means not shown.

Each subtraction-stop 81 is provided with a cam-bar or extension 101, which, as the carriage moves into the corresponding subtraction-zone in a letter-feeding direction, engages the beveled face et a dog or tappet 105 pivoted at 106 on a subtraction-trip lever 107, and rocks the latter about its pivot 91, thereby lifting a link 108 and Swinging a bail 109 connected thereto against the action of-a spring 110. This movement will also effect movement to the right, viewed from the front, of a transversely-extending link 111, guided at its outer end by means not sliown,and withdraw the end of said link from the path of an arm 112 of a threearmed lever 113, thereby permitting the latter to be swung in a clockwise direction about the axis of the shaft 66. The lever 113 is provided with an upwardly-extending arm 114 normally in engagement with a finger 115 extending laterally from an arm 116 tixed on the shaft 66, and the movement of the lever 113 in a clockwise direction will actuate the arm 116 and consequently the shaft 66. so as to withdraw the hook 67 from engagement with the shoulder 68. The subtraction-bar will then be moved to the rear by its spring 70a and the machine Set for subtraction'. A forwardly-extending arm 117 of the lever 113 is provided with a cam-surface 118, so that, upon the forward movement of the general operator, the bar 49 thcreofwill engage the cam-surface 118 and restore the lever 113 to its normal position, so that its rearwardly-extending arm 112 may again be held in raised position by the link 111. The mechanism described so far is similar in general to that disclosed in the patent to Minton, No. 1,280,065, granted September 24, 1918.

Advantage may be taken of the fact that resetting of the subtraction-bar may be effected by the general operator, in carrying out the object oi the invention, namely, of insuring that the machine, if set for subtraction. will be restored to addition when the carriage is backed into a computing zone. Ordinarily, when the left-hand beveled face 88 of the tappet 85 is engaged by the downward extension 82 of one of the stops, the tappet will be rocked idly about its pivot. When, however, the machine is set for sub traction, the tappet 85 is. locked against such swinging movement, so that the downward extensionp82 of a stop will exert a camming action on the beveled face 88, therebyvde pressing the tappet 85 and throwing the general operator into operation to restore the machine to addition. For this purpose, the tappet 85 is provided with a vertical slot 119, and the lever 107 is provided with a pin or projection 120 normally lying above said slot, but which. upon depression of the tappet 105, will be carried into the slot 119, and will prevent swinging oil the tappet 85 about its pivot when engaged by one of the downward extensions 82 during the return movement of the carriage. it wiil be seen that the pin 120 has been cut away to form two faces at a right angle with each other, so that change from ineffective relation to effective relation between pin 120 and dog 85 may be effected quickly.

Obviously, when the tappet 105 is held in depressed position by the cam-bar 104, the tappet 85 will be locked against idle movement about its pivot, but, upon movement out of the subtraction-zone, the tappet 105 will be released from the action of the cambar 104, and, unless provision is made of some other holding means, the tappet 85 will no longer be locked against such idle movement. To retain the tappet 105 in locking position, the link 111 is provided with a notch 121, and a frame 122, comprising two parallel side plates 123, is pivoted at 124 on a xed part of the machine. A hook or latch 125 is pivoted at 124 in the frame 122, and is pressed by means of a spring 127 against the rear face of the link 111 at one side of the notch 121, so that, when the link iS drawn to ineffective position` the latch 125 will drop into the notch 121, and the link 111, by means of the bail 109 and link 108, will maintain the lever 107 in actuated position, thereby retaining the pin 120' in effective position in slot 119. When, therefore, the carriage is backedinto another computing zone, the downward extension 82 of the corresponding stop will depress the tappet 85 and trip the general operator.

Upon forward movement of the general operator, the fra-me 122, which has been held in effective position by means of an arm or rod 128 fixed on the frame 122, and engaging the rear end of one of the side bars of the general operator, will be released to the. action of a spring 129, and the upper end thereof will be swung rearwardly to the position shown in Figure 9, thereby releasing the link 111 and enabling the subtractiontrip mechanism to return to its normal position. Upon the return of the general almenos operator. to its normal position, the trame l 122 will be returned to its normal position lll (Figures 7 and 8).

It will beevident that, in the mechanism so far described, if the machine is set for subtraction by means of the subtraction-hey 63, the tappet 105 will not be depressed and the machine will notbe reset for addition when backed into a computing Zone. Provision must therefore be made oi some means to actuate the subtraction-trip lever 107, and thereby loc-lr the tappet 85 against idle movement about its pivot. For this purpose, provision is made of a lil-shaped lever 130 pivoted on a shouldered screw 131 on a ixcd part of the machine, the normal position ot the lever being determined by a spring 132 attached at one end to the lever 130 by a screw 133, and at the other end to a iixed part of the machine by a screw v@ne arm of the 'tl-shaped lever is provided with a cam-member 135 opposite the rear end ot the subtraction-bar 70, so that, upon movement of the latter to the rear, it will `force the member 135 downward by a camming action, and rock the lever 130 about its pivot 131. On the other arm of the lever provision is made oi a pivoted lever` 136 having a hook 137 at its end farthest from the subtraction-bar, the lever 136 being urged to normal position by means of a spring` 138 connecting it with the cam-member 135.

Upon movement of the subtraction-bar i0v to the rear, lever 130 will be rocked thereby, and the secondary lever 136 moved to the right with the hook 137 on the lever 136 c11- gag'ing a pin or rod 139 fixed on the link 111, thereby drawing the latter from its eliectivc position (Figure 5) to an ineffective position {Figure 6l, and enabling the latch 125 to drop'into the notch 121. As shown in igure 6, the link 111 is moved past the position necessary for the latch 125 to drop into thc notch 121, and, in this additional movement, the advancing upturned end 140 of the secondary lever 136 will strike a suitable stop or abutment 141, and the lever 136 will be swung suiciently to withdraw the hooi; 137 from engagement with the rod 139, so that Ithe link 111 will be retained in ineffective position by the latch 125 only. Upon movement of the hook 137 to ineiiective position, as shown in Figure 6, the rod 139 may pass over the hook 137 when the link 111 is released by the hook 125. The rod 139 will, however, remain over the outer end of the hook 137, so that, upon movement oi the lever 130 to its normal position, ire-engagement of the book 137 and rod 139 will be sure to be effected. The Atappet 85 is then locked against idle movement on its pivot, and, upon backing into a computing zone, the general (perator will be thrown inio operation an the mechanism restored to addition, as previously described.,

provided with an arm 143 to receive screw 1311 its outer end. rlhe stop or abutment 1111 may also .be formed by suitably cutting and bending a 4 plate 1411, and this plate may be secured to the plate 142, with the abutment 1&1 projecting' over the upper edge oi the latter into the path of the end 'ie-0 ot lever 136.

Variations may be resorted to within4 the scope of the invention, and portions oi' the improvements may be used without others.

Having thus described our invention, we claim:

1. 1n -a combined typewriting computting; machine, in combination, mechanism including; numeral-keys 'and a traveling carriage, computing' mechanism, normally set for addition, including a register, numeral-lrey-actuated means for indexing digits as typed, a generalnperator -tor actuating the register in accordance with the digits indexed, and subtractionsetting means, motor means for actuating said general operator, addition and subtraction stops mounted on said carriage, a motor-triodevice engaged and actuated by said stops. during movement of the carriage in n letterfeeding direction, but ast Which'the stops normally pass idly in t e opposite directioi a subtraction-trip operable by said carriage only in letter-feeding direction, and means controlled by the subtraction-trip to render the motor-trip-device actuable by said stops when 'the carriage is backed across the rrachine.

2. In a motor-operated combined i2n writing and computing machine, settacle to subtraction, in combination, a carriage, addition and subtraction Stops, settable at letter-space intervals along said carriage, a motor-trip-lever adjacent the path of said stops, a tappet pivotally mounted on said lever, so that, when engaged by vone of said stops, in letter-feeding movement thereof, it will be held Xed on 'the lever and the latter will be actuated, but, when engaged during the return movement of the carriage, it will turn about its pivot to ineffective position, and. a subtraction-trip-device, which, when operated, will prevent such turning of the tappet about its pivot and will cause the motor-trip-lever to be actuated by said stops during' return movements of the carriage.

3. In a motor-operated combined typewriting and computing machine, settable 'to subtraction, in combination, a carriage, addition and subtraction stops, settable at letter-space intervals along Said carriage, a

motor-trip-lever adjacent the path of said stops, a tappet pivotally mounted on said lever, so that, when engaged by one of said stops, in letter-feeding movement thereof, it will be held fixed on the lever and the latter will be actuated, but, when engaged during the return movement of the carriage, it will be turned about its pivot to ineffective position, a subtraction-trip device, which, when operated, will prevent such turning of the tappet about its pivot and Will cause the motor-trip-lever to be actuated by said stops during return movements of the carriage, and means to latch the subtraction-trip device in position to prevent movement of the tappet about its pivot.

4. In a motor-operated combined typewriting and computing machine, settable to subtraction, in combination, a carriage, means for yindexing digits when typed, means including a general operator to compute numbers when the digits thereof have been indexed, additionl and subtraction stops, settable at letter-space intervals along said carriage, a motor-trip-lever adjacent the'path of'said stops, a tappet pivotally mounted on said lever, so that, when engaged by one of said stops, in a letter-feeding movement thereof, it will be held fixed on the lever` and the latter Will be actuated, but, when engaged during the return movement of the carriage, it Will be turned about its pivot to ineffective position, a subtraction-trip device, which, when actuated, will, prevent such turning and enable actuation thereof by said stops in the return movement of/ the carriage, means effective, upon operation of the Subtraction-trip device, tol latch the same in position to prevent movement of said tappet about its pivot, and means, whereby, upon operation of the general operator, the latching means Will be rendered ineffective.

5. In a combined typewriting and computing machine, in combination, a carriage, computing mechanism including a subtraction-setting member yieldably urged to operate, a latch to prevent such operation, manual means to release said latch, carriage-controlled means having a one-way connection with said latch to release the same, and means actuable by said member, when released by said manual means, to operate said carriage-controlled means and then release .the same.

6. 'In a combined typewriting and computing machine, in combination, a carriage, computing mechanism including a subtraction-setting member yieldably urged to operate, a latch to prevent such operation, manual means to release said latch carriagecontrolled means having a one-way coni nection with said latch to release the same,

means actuable by said member, when released by said manual means, to operate said carriage-controlled means and then release the same, and a' latching device to hold the carriage-controlled means in operated condition.

7 In a computing machine, in combination, digit-indexing means, a general operator to effect computation of numbers so indexed, subtraction-setting means, a lever urged to actuate the subtraction-setting means, a reciprocable locking member to hold said lever in ineffective position, and a device comprising a spring-pressed latchlng member normally in engagement with said locking member, so that, upon movement of the locking member to ineffective position, the latching member will enter an opening therein and detain it in said ineffective position.

8. In a computing machine, in combination, digit-indexing means, a genera-l operator to effect computation of numbers so indexed, subtraction-setting means, a lever urged to actuate the subtraction-setting means, a reciprocable locking member to hold said lever in ineffective position, a device comprising a spring-pressed latching member normally in engagement with said locking member, so as to enter an opening therein and detain it in ineffective position when moved thereto, and general-operatorcontrolled means to render the device effective when the general operator is in normal position and lneffective when the general operator is moved therefrom.

9. In a computing machine, in combination, state-setting mechanism including a reciprocable bar urged in a direction to e1'- fect a change of state, a device to hold said bar against movement in such direction, manually-operable means to render said ldevice ineffective, a member having a one-way connection with said device to operate the same, and being urged in a direction to operate the device, a latch to prevent such movement of the member, and means, Whereby, upon release of the bar by said manually-operable means, the latch will be withdrawn to ineffective position,

10. In a motor-operated computing machine, inl combination, subtraction-setting mechanism, a carriage, a stop positioned thereon, a motor-trip-lever, a tappet pivoted on said lever, an abutment on said lever to support -said tappet, so that, when the latter is engaged by said stop. in a letter-space movement of the latter, the lever will be actuated, a spring normally maintaining the tappet against the abutment, but permitting it to be swung into ineffective position bythe stop during the return movement of the carriage. and means actuable by said subtraction-setting mechanism, whereby the tappet will be locked' against movement away from said abutment, and, upon engagement thereof bythe stop in its return movement, the motor-trip-lcver will be actuated.

11. In a computing machine, in combination, digit-indexing means, a general operator to effect computation of numbers so indexed, subtraction-setting means, an operating member urged to actuate the subtraction-setting means, a reciprocable locking member to hold said member in ineffective position, and a latching device for said iocking member comprising a yieldingly-urged member normally in engagement with said locking member and holding said late-hing device ineffective, said yieldingly-urged member being released by said locking member when the la-ter is moved to ineffective position, thereby rendering lsaid iatching device etfective.

12. In a power-operated computing machine, in combination, a carriage, an operating member mounted thereon, motor-trip mechanism including a lever having an abutment thereon and a tappet pivoted nthereon and yieldingly pressed against said abutment, whereby said tappet, when engaged by said member in a letter-feeding direction, will serve to actuate the lever, but, when engaged by the member in a reverse movement, will be swung about its pivot idly, and means to lock said tappet against the abutment to enable the lever to be actuated by said member when the latter is moving in the reverse direction.

13. In a power-operated computing machine, in combination, a carriage, an operating member mounted thereon, motor-trip mechanism including a lever having an abutment thereon and a tappet pivoted thereon and yieldingly pressed against said abutment, whereby said tappet, when engaged by said member in the letter-feeding direction, will serve to actuate the lever, but, when engaged by the member in the reverse movement, will be swung about its pivot idly. said tappet having a, slot therein` and locking means for said tappet comprising a member to enter the slot in the tappet and hold the latter against pivotal movement away from the abutment.

14. In a power-operated computing machine, in combination, a carriage, an operating member mounted thereon, motor-trip mechanism including a lever having an abutment thereon and a tappet pivoted thereon and yieldingly pressed against said abutment, whereby said tappet, when engaged by said member in the letter-feeding direction, will serve to actuate the lever, but, when engaged by the member in the reverse movement, will be swung about its pivot idly, subtractionfsetting means, and means rendered effective by the subtraction-setting means for locking said tappet against movement away from the abutment. so that the tappet, upon engagement by the member moving in the reverse direction, will serve to actuate the lever.

15. In a power-operated computing machine, in combination, a carriage, an operating' member mounted thereon, motor-trip mechanism including a lever having an abutment thereon and a tappet pivoted thereon and yieldingly pressed against said abutment, whereby said tappet, when engaged by said member in a letter-feeding direction, will serve to actuate the lever, but, when engaged by the member in a reverse movement, will be swung about its pivot idly, subtraction-setting mechanism, means rendered effective by the subtractionsetting mechanism for locking said tappet against movement away from the abutment, so that the tappet, upon enga-gement by the member moving in the reverse direction, Will serve to actuate the lever, and means for detaining said subtraction-setting mechanism in operated condition.

16. In combination, a traveling carriage. a computing mechanism normally for addition, carriage-actuated means for de termining computing zones, subtraction.- setting means, means for restoring said subtraction-setting means to ineffective con.- dition, and means, effective only when the machine is set for subtraction, whereby backing of the carriage into a computingv zone will cause the restoring means to be actuated.

17. In combination, a traveling carriage, computing mechanism normally set for addition and including means for indexing numbers, and a general operator for effecting computation of the numbers so indexed, subtraction-setting means returnable to ineffective position by said general operator, controlling means effective, as the carriage passes out of a computing zone in lett-erfeeding direction, for automatically throwing said general operator into action, but normally ineffective when the carriage is backed into said zone, and means whereby, when the machine is set for subtraction, said controlling means will be effective when the carriage is backed into the computing zone.

18. In a combined typewriting and computing machine, in combination, means including a carriage for determining computing zones, computing mechanism normally set for addition, subtraction-setting means, manually-operable means for setting said subtraction-setting means, yieldablyurged means to actuate said subtraction-setting mea-ns and having a one-way connection therewith, a subtraction-trip device normally preventing operative movement of said yieldably-urged means and actuable b v said carriage only when the latter is moving in a letter-feeding direction, resetting means 'for said subtraction-setting means normally effective only when the carriage moves out of a computing zone in the letterfeeding direction, means whereby said subtraction-drip device, when actuated, Will render said re-setting means effective when the carriage is backed into a computing zone, and means whereby actuation of said manually-operable means will render the resetting means effective When the carriage is backed into the computing zone.

19. In a combined typewriting and computing machine, in combination, computing mechanism settable for subtraction, motor means for actuating said computing mechanism and re-setting the machine to addition at the end of said actuation, means, including a carriage, for determining computing zones, means whereby the carriage Will start the motor means when moved out of a computing zone in the letter-feeding direction, but will be ineffective thereon in the return movement, and means whereby the computing mechanism, when set for subtraction, will render the carriage effective on the motor means in its return movement into a computing zone.

20. In a combined typewriting and computing machine, in combination, a carriage, a subtraction-trip device actuable thereby,

subtraction-trip device to hold and a latching device normally held out of action by said subtraction-trip device, but effective thereon, upon operation of the latter, to co-operate therewith and hold it in actuated condition.

21. In a combined typewriting and computing machine, in combination, a carriage, a subtraction-trip device actuable thereby, and means, independent of the carriage, rendered effective upon actuation of said the latter in actuated condition.

22. In a combined typewritingr and computing machine, in combination, a carriage, a. subtraction-trip device actuable thereby, a re-settingr trip device normally actuable by the carriage at predetermined positions o-f the latter as it moves in a letter-feeding direction, and means whereby actuation of said subtraction-trip device will render said re-setting device effective at the first of said predetermined positions passed by the carriage in the return movement thereof.

FRANK K. DAVIS. CHARLES C. TAYLOR.

Witnesses GEORGE F. HAND, M. V. NICHOLS.

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