US2835441A - Restoring mechanism for adding machine indexing means - Google Patents

Description

May 20, 1958 R. w. PlTMAN RESTORING MECHANISM FOR ADDING MACHINE INDEXING MEANS 4 Sheets-Sheet 1 Filed Nov. 3. 1954 Q lNl/ENTOR RICHARD w p/ TMAN d ATTORNEY May 20, 1958 R. w. PITMAN ,83

RESTORING MECHANISM FOR ADDING MACHINE INDEXING MEANS Filed Nov. 3, 1954 w 4 Sheets-Sheet 2 I INII/ENTOR R/CHARDWP/TMAN AT TORNEV May 20, 1958 w, PITMAN 2,835,441

RESTORING MECHANISM FOR ADDING MACHINE INDEXING MEANS Filed NOV. 3, 1954 4 Sheets-Sheet 3 RICHARD WP/TMAN ATTORNEY y 20, 1958 R. w. PITMAN 2,835,441

RESTORING MECHANISM FOR ADDING MACHINE INDEXING MEANS Filed Nov. 3, 1954 4 Sheets-Sheet 4 i4 /0/ 2 jjjjj;;1j r 1 I Z; 417 80 i 50 50 4f 1 "m m a;

' CAM 0 3O 60 90 I20 I50 I80 ZIO 240 270 300 330 TYPEBARS N REGISTER RACKS DISENGA T TA O INVENTOR WP/TMAN CARRYOVER 4% PRINTINQ A TTORNEV erated line. 'operated since the usual A. (1-D. C. electric motors re- RESTORING MECHANISM FOR-ADDING MACHINE INDEXING MEANS Richard W. Pitman, Laverock-Hillcrest, Pa.,-'as'signor to Underwood Corporation, New York, N. Y., a corporation-of Delaware Application'November 3, 1954, Serial No. 466,645

6 Claims. (CL 235'---60) This invention relates to improvements in a -ten key adding machine, and more particularly to improvements forsimplifying the construction of'such a machine.

Ten-key addingmachines are-wellknown-andhave-been "on the market for many years with many companies marketing inexpensive machines which, generally, are

stripped down versions of their higher priced motor-p- Such inexpensive machines are all manually quired to drive the machine are not economically possible at the competitive price level. The machine disclosed in this application is particularly designed to be powered by an inexpensive A. C. motor of the shaded pole type used for fans and similar light duties and may be constructed mainly of simple, automatically producible 'parts.

'It is a major object of this invention to devise a ten key adding-machine of a minimum number of parts, most of which are metal stampings.

It is also an object of this invention to produce an adding machine indexing mechanism which is simple in design and requires a minimum of force to operate with no peak load points.

Another object is the inclusion of a pin carriage restoring mechanism which maybe locked in a disabled position for one cycle to provide a repeat entry of an item whether the repeat key remains operated during a cycle or not.

Other objects will be in part obvious or pointed out in the following description and accompanying drawings of a :preferred embodiment of the invention.

In the drawings:

Figure 1 is a left elevation of the mechanism of the machine,

Figure 2 is a vertical section taken on a front to rear line through the machine,

Figure 3 is a left side view of the pin carriage restoring and item repeat mechanism,

Figure 4 is a view of a portion of Figure 3 showing the parts in operated position,

Figure 5 is an isometric view of the mechanism of Figure 3, I

Figure 6. is a plan view of the motor drive and the cycling clutch controls therefor,

Figure 7 is an isometric view of the register engaging cams and the zero eliminating control for total printing,

Figure 8 is a view showing a part of the total signal printing mechanism,

Figure 9 is a rear view of the amount indexing mechanism,

Figure 10 is a sectional view showing the numeral key connections to the escapement and pinv setting members,

Figure 11 is a front elevation of the platen,

Figure 12 is a right side view showing the platen printing stop, and

Figure 13 is a diagram showing the timing of the operating members.

2 General description The disclosed adding machine is of the well known ten key type and is driven by a rotary drive shaft cyclically energized by an electric motor and driving a group of cams. Numerical items are set up by the ten numeral keys in settable pins of a travelling pin carriage controlled in its travel by a key operated escapement. The set pins of the pin carriage limit, during a cycle, the travel of aligned type bars to present type at a printing line. A platen, a paper tape around the platen and an inked ribbon are then swung against the type bars to record the set up item on the tape and a register is engaged with a toothed portion of the type bar to enter the set up values in the register during the return of the bars to a home vposition. When the type bars are fully restored, the pin carriage is returned to a home position to reset any set pins in preparation for the succeeding entry.

The machine is also operable to print the total of accumulated amounts by engaging the register with the type bars prior to initial movement of the bars and utilizing the tens'carry mechanism to arrest movement of the type bars at a number corresponding to that originally in the regin both item or total printing operations, the platen mechanism'is so designed that the pressure exerted against the individual type bars will be substantially constant irrespective of the number of bars against which the %platen presses. This is accomplished by mounting the platen in its frame at a'slight angle from the printing line and arresting one end of the platen near the end of the printing stroke to effect a seriatim pressure on the bars.

More specifically, the operating mechanism is mounted on a framework comprising a base plate 15, Figure 1, resiliently mounted on feet 16 and supporting right and left sidepla'tes 1-8 and 19, respectively, see also Figures 2 and-11. The base 15 also supports a shaft 21, to be later described, in bearings 22.

Cycling mechanism The machine is driven by a rotary cycling mechanism 'engageable for one cycle of operation by motor keys in the keyboard. Referring to Figure 6, a shaft 24 of a motor, not shown, mounted on right side plate 18 has a "gear 25 secured thereto to drive a gear 27 rotatable in side plate 18, A shaft 28 is slidably' and rotatably mounted in a bearing 30 in side wall 19 and passes through the open axis of gear 27. Shaft 28 has a collar 31 secured thereto and also a clutch member 33 sl'idabl'e thereon but prevented from rotating on the shaft by a pin 35 in shaft 28 engaging in hole 36 of'the member 33 with a spring 34 between collar 31 and clutch member 33 to yieldably hold member 33 to the right. Clutch member 33 and the hub. of gear 21 have mating teeth formed thereon toprovidedriving engagement between these parts when shaft 28 is: moved to the right.

Secured: to: the left end of shaft 28 outside plate 19 are a-grooved collar38i and a gear 39. Gear 39meshes with *a. large gear 41 rotatable on a stud 42 secured in left side also Figures 1 and 2, each of which keys has a lug engageable with ears on a rockable plate 50 pivoted in spacer bars 51 of the keyboard plates to be later described; see also Figure 10. Plate 50 has a rearward extending arm 53 which will when plate 50 is rocked by operation of a key, engage a cam edge of a. trip link. 54

mounted outside of plate 19 on a stud 55 in plate 19.

A spring 57 on stud 55 presses the forward part of link 54 against side plate 19 which has a slot therein to allow the cam edge of link 54 to pass through into contact with arm 53 of plate 50. The rear end of link 54 is bent outwardly and engages in the groove of collar 38 with the bend line serving as a rocking fulcrum on plate 19. A bent off ear 58 of link 54 is normally engaged in a notch of ring 44 to hold gear 41 in a home position. When any motor key is operated, link 54 is rocked about its fulcrum on plate 19 to remove ear 58 from the notch of ring 44 and to shift shaft 28 rightwardly to engage the teeth of member 33 and gear 27. The right end of shaft 28 when moved rightwardly is utilized to close a switch, not shown, to energize the driving motor and thereby start rotation of shaft 28 and gear 41. As soon as gear 41 starts rotating, clockwise in Figure l, the notch of ring 44 moves away from ear 58 and upon release of the operated key, the ring 44 maintains link 54 in its operated position until gear 41 completes a full revolution and ear 58 can again drop into the notch to disconnect clutch member 33 from gear 27 and de-energize the motor.

Type bars The machine is provided with a plurality of type bars 60, Figure 2, one for each denominational order, arranged for sliding movement on a plate 61 secured between side plates 18 and 19. Each type bar 60 has at its forward end a tail 62 passing downwardly through a slot in plate 61 and an upwardly extending ear 64 to limit movement of the bars 60 during item entry operations. The type bars are each formed with a rack and a notch in their upper surfaces and each has secured thereto a type bearing plate 65. A spring 66 is connected between each type bar tail 62 and the rear edge of plate 61 to urge the bars rearwardly but the bars 60 are normally restrained in their forward position by a plate 68 engaging the tails 62 and guided in slots 69, see also Figure l, in plates 18 and 19. The rear end of plate 68 is pivoted on an arm 70 secured to shaft 21 on base 15. Another arm 72 on the left end of shaft 21 is connected by a link 73 to a cam follower 74 pivoted on a stud 76 in side plate 19 and urged clockwise by a spring 77 into contact with a cam 78 secured to gear 41. As may be seen from the first line of the timing diagram Figure 13, the cam 78 during a rotation of gear 41 will first release the type bars 68 for movement to align their type at the printing line and then after a short pause will release bars 60 for further rearward movement until they are difierentially arrested in a manner to be later described. During the second half of a revolution of cam 78, bar 68 will be driven forward to first return all type bars to the 0 position and again after a short pause, to restore bars 60 to their normal forward position.

Item set up mechanism The rearward movement of type bars 60 to print and register an item is controlled by a set of digit keys 80 and a shiftable pin carriage 81 carrying a plurality of rows of pins 82, see Figures 2, 3, 9 and 10. The digit keys 80 are guided for vertical movement in slots in an upper keyboard plate 84 secured by spacer bars 51 to a lower keyboard plate 85 secured between side plates 18 and 19. Each key stem of a key 80 is formed with an arm extending over an escapement bail 86, Figure 10, pivoted in the two left spacer bars 51 and tensioned upwardly by a spring 87 with the arm of each key stem except that for the "9 key having a pin setting projection passing through lower keyboard plate 85. Compression springs 88 between the plate 85 and the arm of each key stem normally holds the keys 80 in their upper positions.

Mounted below the keyboard plate 85 on horizontal rods 89 secured between depending ears of plate 85, is the pin carriage 81 comprising upper and lower plates secured together and embracing rods 89 for sliding movement of carriage 81. The settable pins 82 pass through the pin carriage plates and are frictionally held in any set position by a spring wire passing in serpentine fashion through a row of pins, by leaf springs or other suitable friction devices. Pins 82 are arranged in rows with the pins in each row being alignable with the pin setting extensions of keys under control of an escapement mechanism hereinafter described and each pin 82 when set by a key 80 has its lower end in the path of the ear 64 of the type bar 60 with which it is aligned to arrest the type bar 60 at the digit value corresponding to that of the operated key 80. A plate 92 fixed to the rear of pin carriage 81 will arrest any type bar 60 reaching it at the 9" position and therefore it is not necessary to set a pin 82 when the 9 key 80 is depressed. To prevent rearward movement of type bars 60 for which no pin 82 has been set, a bracket 93, Figures 3, 5 and 8 is secured to the left side of the pin carriage 81 to pivotally support a zero stop plate 94. Stop plate 94 in the normal position of pin carriage 81 lies just to the rear of the ears 64 of type bars 60 and is moved from in back of successive ears 64 by the movement of the pin carriage incident to the setting of a pin 82 in a position to limit movement of a type bar 60.

The pin carriage 81 is urged to the left by a spring 90, Figure 9 connected between the carriage and an arm 91 secured to and extending leftward from the lower keyboard plate but is restrained by an escapement dog 97, Figure 9, pivoted to an ear on escapement bail 86. A spring 98 connected between the bail 86 and the dog 97 holds the end of the dog under an ear 99 of bail 86 with the edge of the dog 97 just to the right, left in Figure 9, of the edge of car 99. A rearwardly extending portion 101 of pin carriage 81 is bent into engagement with dog 97 and is provided with notches, Figure 10, having the same spacing as the rows of pins 82 and the type bars 60. The ear 99 and dog 97 are alternatively engageable with the notched part of carriage 82 each time the escapement bail 86 is rocked by depressionof a key 80 to provide a step by step movement of pin carriage 81 in the well known manner.

An interlock to prevent operation of a numeral key 80 during a machine cycle or operation of a motor key 45, 47 or 48 while a numeral key is depressed is provided in the machine. As shown in Figures 9 and 10, a lever 102 is pivoted on top keyboard plate 84 and its rearward end is engaged in a slot of the trip link 54 to be rocked counterclockwise upon each depression of a motor key 45, 47 or 48 as above set out. The forward end of lever 102 is engaged in a slot of a key lock slide 103 which is guided between the keyboard plates 84 and 85 and which will have its right end (Figure 10) inserted under the escapement bail 86 during the whole time that the trip link 54 is held rocked by a motor bar 45, 47, or 48 or by ring 44 on gear 41. Such interposition of slide 103 will prevent operation of a numeral key during the entire machine cycle and, if a numeral key should be held depressed, it will prevent any effective operation of one of the motor keys.

Pin carriage restoring mechanism The pin carriage 81 is normally returned to the right near the end of a machine cycle to restore any set pins and thus prepare the machine for entry of a new item. Referring to Figures 3, 4, and 5, a link 105 is pivotally connected between bracket 93 of pin carriage 81 and an arm 106 pivoted on a post 10.7 secured to keyboard plate 85. Also slidably pivoted on post 107 is a bail 109 having a shoulder 110 normally engaged between a forward ear 111 and a rearwardly bent up ear 112-on arm 106. A spring 114 connected between arm 186 and bail 189 normally maintains shoulder 11% against ear 112 to hold an ear 115 of bail 189 in position to be engaged near the end of a machine cycle by a cam 116 fixed tov gear 41 inside of ring 44. Engagement of the cam 116 with ear 115 of bail 109 will swing bail 189 to engage shoulder 110 with ear 111 of arm 106 and return pin carriage 81 to its rightmost position where it will be retained by escapement dog 97.

During such restoration of pin carriage 81 to the right, any set pins 82 will be reset to their upper ineffective position by a cam plate 118, Figure 9, secured to side wall 18 under the pin carriage 81.

Should the operator make an error in setting up an item or wish to clear out a set up item for another reason without printing or entering such amount, an error key 119 is provided. This key 119 is slidable in the keyboard plates 84 and 85 and has a spring 120 similar to springs 88 for numeral keys 80 to hold key 119 in its upper position. An ear of key 119 is engaged by an arm of a bell crank 122 tensioned upwardly by a spring 123 and having a hooked end 124.

By depression of error key 119, bell crank 122 may be pivoted counterclockwise, Figure l, to bring its hooked end 124 into engagement behind bar 68. During an ensuing machine cycle which may be initiated by operation of either key 45 or 47, bar 68 is prevented from releasing type bars 60 so there will be no printing or item entry and the only effective operation will be the restoration of pin carriage 81 to its initial position.

Item repeat mechanism When the operator wishes to retain a set up item for a number of cycles as in multiplication operations, a machine cycle is initiated by operation of repeat'key 48. This key in addition to operating the cycle trip plate 50 also rocks a lever 126 which underlies key 48 and is pivoted on the rear pin carriage rod 89. A compression spring 127, Figure 5, between a collar 128 fixed on rod 89 and the right edge of lever 126 urges lever 126 to the left, right in Figure 5, to hold its left edge in contact with a pin 13,8 fixed in plate 85 adjacent to rod 89. When the lever 126 is rocked by depression of key 48, a slot 131 in .lever 126 is aligned with the pin 130 and lever 126 is moved by spring 127 rightwardly in Figure 5 to retain lever 126 in its rocked position as shown in Figure 4.

' The rear end of lever 126 underlies a tooth 132 projecting from bail 199 and will, when lever 126. is rocked, raise the bail 189 so that its shoulder 110 is above the ear 111 of arm 186. In the ensuing machine cycle, arm 106 will not be rocked by the bail 189 and the item set up will be retained. Near the end of the movement of bail 109 in this operation, tooth 132 of bail 109 will strike an car 135 on lever 126 to shift the lever back to the right side, disengaging pin 130 from slot 131 and so freeing lever 126 for return to its ineffective position. Restoration of lever 126 is, however, not positive and so long as key 48 is held depressed, the machine willcontinue to cycle and repeatedly add the set up amount. For the last cycle, the motor bar 45 and, if the item is not to be entered, the error key 119, may be operated to clear out the set up item.

Printing mechanism The machine includes a printing mechanism to make a record of the items entered and the totals thereof but as this mechanism forms no part of the invention claimed herein, it will be but briefly described. As shown in Figures 1 and 2, a platen 136 is rotatably supported in A roll of paper tape 147 is supported on a rod 149 and the tape from the roll is passed between platen 136 and a set of spring pressed eed rolls around platen 136 and below the type plates 65 and then out to the rear of the machine. After a record is made on the tape 147 by upward movement of the platen 136, the tape is stepped to the rear by a detent 156, see Figure 2, which engages in the teeth of a ratchet wheel on the right end of platen shaft 137 to turn the platen during return movement of the platen frame 138.

An inked ribbon 159 passes between two tape spools 160, one on each side of the machine and rotatable in lower extensions of platenframe 138 with the ribbon passing over the platen 136 between the type plates 65 and the paper tape 147 so that pressure of the tape 147 against the inked ribbon and type bars 65 will record on the paper. A shaft 169 with a pair of pawls 173 and 168 thereon is pivotally mounted in plates 18 and 19 below the ribbon spools 168 and is spring held in a set position by an over center spring 172, Figure l. The other end of spring 172 is secured to a tape follower arm 174 which acts to reverse the position of shaft 169 when the tape on the left hand spool nears exhaustion or the capacity of the spool and hence reverse the direction of drive of the tape 159 across the platen.

As shown in Figure 11, the right end of platen 136 is slightly higher in frame 138 than is the left end. An adjustable stop 145 first arrests the right platen frame 138 as the right hand type bars 60 are contacted by platen 136. The remainder of the bars 60 will be contacted by platen 136 through a twisting of the platen frame 138 by the drive from arm 142 and movement of platen 136 will be substantially .a rocking motion so that all type will be contacted with about the same pressure giving even printing irrespective of the number of type being contacted by the platen 136.

Item entry registration A register mechanism is provided to sum up the items entered by key 80. The frame for the register comprises a U shaped member 178, Figure 2, pivoted in the side frames 18 and 19 by ears 179 secured to frame 178. Secured to the bottom of frame 178 is a bracket 181 having forwardly extending arms in which is mounted a shaft 182 rotatably supporting a plurality of register wheels 183. Frame 178 is rockable about its pivots 179 to engage register wheels 183 with racks 185 out in the upper surfaces of type bars 60 to enable rotation of wheels 183. A slotted leaf spring detent 186 is secured to the upper part of frame 178 and is bent into engagement with the teeth of wheels 183 to yieldably hold the Wheels 183 in any set position.

A tens transfer mechanism to move the next higher denomination wheel 183 one additional step whenever a wheel 183 passes from its 9 to its 0 position is provided in frame 178. The tens carry mechanism comprises, for each order, a slide 187 and a spring 189. Each slide 187 is slidable in slots in frame-178 between a pair of wheels 183. The slides are slidably retained in the slots of frame 178 by a stop plate 188 at the, bottom and a bracket 198 secured to the top of frame 178 and are urged downwardly by their springs 189. Normally, the slides are retained in their Figure 2 positions by the engagement of a shoulder 191 on the slides with stop plate 188 until during the rotation of a numeral wheel 183 between its 9 and 0" positions, a wide tooth 193 of a wheel contacts a cam surface 194 on slide 187 to move the bottom end rearwardly off of stop plate 188 permitting spring 189 to move the slide 187 downwardly until a nose 195 at the top of the slide contacts a restoring bail 196. When bail 196 is moved downwardly to permit slide 187 to move to its lowest extent, a tooth 199 extending to the left from slide 187 will engage a tooth of the next higher denominational wheel 183 to move it one space. If another slide 137 is released by such movement of a wheel 183, it will be free to move downwardly and transfer to the next higher wheel 183.

' The restoring bail 196 is secured to a shaft 201) pivoted in arms 281 secured to frame 178. On the left end of shaft 280 is a cam follower arm 283, Figure 1, tensioned clockwise by a spring 2114 around shaft 286 into contact with a cam 285 secured to gear 4-1. The movement of bail 196 by cam 285 is as shown in the fourth line of l Figure 13 wherein slides 187 are shown held in their restored positions until the register wheels 133 are engaged with racks 185 after which the slides are reed for movement to a set position by the Wheels 183 which move from their 9 to position. After the wheels 183 are removed from racks 185, the bail 196 is lowered to permit the slides 187 to drop to their lower position for carryovers after which bail 196 is again raised to restore slides to their reset positions wherein their shoulders 191 are resting on stop plate The double levels in the restored and set slides positions are to compensate for the movements which frame 173 may make in engaging and disengaging register wheels 183 with racks 185 and do not represent any effective movement of bail 196.

Register engaging mechanism The register wheels 183 are rocked into engagement with the racks 185 by the mechanism shown in Figures 211 on follower 208 passing through a hole therein is a cam follower 212 slidable on stud 76 and urged toward side wall 19 by a compression spring 213. Cam follower 288 is held counterclockwise at the home position of gear 41, Figure l, by a cam 215 secured to gear 11 to hold cam follower 212 free of its cams to enable easy shifting of follower 212 on stud 76. During a machine cycle, cam follower 208 does not follow its cam 215 and is controlled by follower 212.

Cam follower 212 is axially shiftable as above noted to engage either of two cams, an adding cam 216 and a total cam 217, both cams being secured to boss of gear 41 with a slotted blocking plate 219, Figure 1, between them. Blocking plate 219 is not shown in Figure 7 in order that the outline of cam 216 will not be obscured but lies between the two cams 216 and 217 with its slot aligned with the nose of follower 212 as shown in Figure 1. For adding cycles, follower 21?. engages cam 216 and through its connection to follower and link 2117 will shift the register frame 178 as shown on the second line of Figure 13, that is, to engage the register wheels 183 with racks 135 during the return move ment of type bars 68 between their set and their 0 positions. Such register engagement will enable the number set up on type bars 60 to be entered into wheels 183.

When it is desired to print the total of the entered items, the total key 47 is depressed. This key 47 is formed with an inclined ear 229, Figure 7, and when depressed will, in addition to starting a machine cycle as previously described, swing an arm 221 about its pivot in plates 85. Arm 221 abuts the right edge of cam follower 212 and when key 4'7 is depressed will move follower 212 to the left through a slot in blocking plate 219 into engagement with cam 217. During the ensuing cycle, cam 217 will cause the register wheel 183 to be engaged with racks 185 in the total timing shown in the third line of Figure 13, that is, during the rearward stroke of type bars 6 3 from their 0 toward the 9 position. Blocking plate 219 prevents cam follower 212 from moving back to the add position despite a.

release of total key 47 before the end of a machine cycle.

During such rearward movement of type bars 60, the wheels 183 are rotated reversely until their wide teeth 193 are individually engaged by the lower edges of cam surfaces 194 on slides 187 which engagement arrests the wheels 183 at 0 and type bars 63 at a position corresponding to the initial setting of wheels 183 as is well known. The platen 136 will thereafter be driven as set out above to print on tape 147 the item total.

Total key 47 when depressed for a total cycle causes the release of all of the type bars 6t and releases a symbol bar 233, Figure 8, to align a total signal type for printing. As shown in Figures 1 and 8, blocking plate 94 for type bars 60 is pivoted on bracket 93 of pin carriage 81 and underlies key 47 so that depression of total key 47 will lift the forward end of plate 94 and permit free rearward movement of type bars 60 during the machine cycle.

The symbol type bar 223 is normally held by a plate 224 pivoted in side walls 13 and 19 and pulled into engagement with an ear on symbol bar 223 by a spring 225 to normally hold the bar 223 against movement during a machine cycle. When plate 94 is operated by total key 47, the forward edge of the plate contacts an ear on plate 224 to lift the plate 224 away from bar 223 which will during the ensuing cycle, follow restoring bar 68 until the front edge 227 of a slot in bar 223 strikes a stationary pin 228 to align the total signal type on bar 223 at the printing line. Bar 223 will be restored to the latched non-printing position by bar 68 at the end of the machine cycle.

Zero elimination on totals As thus far described, the type bars 60 when released by plate 94 on total taking operations will all move to the 0 position resulting in the printing of non-significant zeros in the higher denominational orders. However, mechanism controlled jointly by the register wheels 183 and the cam follower 212 when shifted to total taking position will cause elimination of such nonsignificant zeros. As shown in Figures 2 and 7, a lever 229 is pivoted On a stud 230 in wall 19 and is tensioned counterclockwise by a spring 231 to bring an inclined front end 232 into engagement with the cam follower 212.

Pivoted on a shaft 233 fixed in bracket of the register are levers 235, one for each numeral wheel 183 except the two of lowest denomination, each lever 235 having an upper end in engagement with a notched collar 236 secured to a numeral wheel 183 and a rear end having a bent olf ear 237 and a shoulder 239. The ears 237 overlap to the left so that any lever 235 which does not engage in the notch of collar 236 and is thereby prevented from dropping counterclockwise will hold up all levers 235 to the right. As the notches of collars 236 are in position under the arms of levers 235 only when the numeral wheel stands at 0, it will be clear that only the levers 235 associated with the denominational orders standing at nonsignificant zeros are free to drop. When any lever 235 does drop the shoulder 239 thereon engages in a notch 240 of the associated type bar 60 and prevents movement of the type bar to the 0 printing position.

The levers 235 are held up to free all bars 60 during adding cycles by an ear 241 on the rear end of lever 229 which ear lies under car 237 of the leftmost lever 235 and so long as the lever 229 is in the Figure 7 position will hold all levers 235 in the non-rack engagingposition. When the total key 47 is depressed and cam follower 212 shifts to the left, Figure 7, lever 229 is permitted to rock to release ears 237 and permit such levers 235 as are aligned with the notches in collars 236 and are not held up by a higher lever 235 to lock their rack bars in their home positions. A stop 243 is secured to frame'178 to 9 prevent excessive upward movement of the rightmost lever 235.

There are no levers 235 for the two right hand type bars 60 and these bars are thus free when a total is taken from a clear register to move to at least the position thus printing .00 to indicate that the register was clear when the total was taken.

The above description of the preferred embodiment of my invention is not to be taken in a limiting sense as substantial modifications and variations of structure are possible without departure from the invention as set forth in the following claims.

What is claimed is:

1. in an adding machine of the class described having a plurality of numeral keys, a shiftable pin carriage having settable pins therein to be indexed by said keys, a register, amount entering means controlled by said pin carriage and machine cycling mechanism, the combination of a restoring arm connected to said pin carriage, a swingable member driven by said cycling mechanism and engageable with said restoring arm to restore said pin carriage to a home position, an item repeat key, a lever operated by said repeat key and latchable in an operated position, said lever moving said swingable member to a non-engaging position with respect to said restoring arm, and engageable extensions on said swingable member and said lever to enable said swingable members to move said lever to an unlatching position during a machine cycle.

2. In an adding machine of the class described having a plurality of numeral keys, a shiftable pin carriage having settable pins therein to be indexed by said keys, a register, amount entering means controlled by said pin carriage and machine cycling mechanism, the combination of a pivotal restoring arm connected to said pin carriage, a swinging plate rotatable and slidable on the pivot of said restoring arm and yieldably urged into engagement with said arm, a cam included in said cycling mechanism to operate said swinging plate in each machine cycle, a repeat key, a lever operated by said repeat key to slide said swingable plate to a non-operating position with respect to said restoring arm, a stationary part, said lever when operated being engageable with said stationary part to hold said lever and said swinging plate in the operated positions, and engaging members on said lever and said swinging plate to move said lever away from said stationary part to a restoring position during a machine cycle.

3. In an adding machine of the class described having a plurality of numeral keys, a shiftable pin carriage having settable pins therein to be indexed by said keys, a register, amount entering means controlled by said pin carriage and machine cycling mechanism, the combination of a restoring arm to return said pin carriage to a home position, a cyclically operated swinging plate normally engaged with said restoring arm, a manipulable member, a lever operable thereby, and means to lock said lever in an operated position, said lever engaging said swinging plate to move said plate to an ineffective position with respect to said restoring arm and said swinging plate when operated moving said lever to an unlocked position.

4. An adding machine of the class described having a plurality of numeral keys, a register, ctuators for said register, indexable means controlled by said numeral keys for controlling movement of said actuators, cycling means for moving and restoring said actuators during a cycle of said cycling means, an arm rockable to restore said indexable means to a non-indexed condition, a swingable plate coaxially supported with said arm and cyclically driven by said cycling means to rock said arm, an item repeat key and means operated thereby to axially move said swingable plate to an inefiective position with respect to said arm.

5. An adding machine as set out in claim 4 including a latching mechanism to hold said repeat key operated means in an operated position, and cooperative parts on said swingable plate and said last means to release said means from said latching mechanism when said plate is driven by said cycling means.

6. An adding machine as set out in claim 4 including a device engageable by said repeat key operated means when operated to hold said means in effective position, a resilient means to urge said means into engagement with said device and cooperative parts on said swingable plate and said means to cyclically move said repeat key operated means out of engagement with said device for restoration to normal position during the first cycle in which said repeat key is not retained depressed.

References Cited in the file of this patent UNITED STATES PATENTS 1,180,556 Wetmore Apr. 25, 1916 1,426,710 Brown Aug. 22, 1922 1,851,401 Munzer Mar. 29, 1932 2,021,618 Sundstrand Nov. 19, 1935 2,062,963 Benninger Dec. 1, 1936 2,158,142 Muller May 16, 1939 2,194,270 Sundstrand Mar. 19, 1940 2,203,533 Landsiedel June 4, 1940 2,221,861 Butler Nov. 19, 1940 2,264,582 Petit Dec. 2, 1941 2,580,031 Liljestrom Dec. 25, 1951 2,682,371 Benninger June 29, 1954

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