US3906206A

US3906206A - Resettable register mechanism

Info

Publication number: US3906206A
Application number: US475759A
Authority: US
Inventors: Bruno S Smilgys
Original assignee: Veeder Industries Inc
Current assignee: Veeder Industries Inc
Priority date: 1974-06-03
Filing date: 1974-06-03
Publication date: 1975-09-16
Anticipated expiration: 1992-09-16

Abstract

A resettable register mechanism having a register with a plurality of coaxial number wheels of ascending order, a bidirectional rotary electrical stepping motor adapted to be electrically stepped in one angular direction for indexing the number wheels to register successive numerical counts and to be electrically stepped in the opposite angular direction for indexing the lowest order number wheel to zero and for operating a heart cam reset mechanism for resetting the remaining higher order number wheels to zero.

Description

United States Patent 1191 Smilgys Sept. 16, 1975 [54] RESETTABLE REGISTER MECHANISM 3,616,996 11/1971 Young .t 235/144 D [75 Inventor: Bruno S. Smilgys, Hartford, Conn. I

Prtmary Exammer-Stephen .l. Tomsky Assigneel veedel' Industries, Hartford Attorney, Agent, or Firm-Prutzman, Hayes, Kalb &

Conn Chilton [22] Filed: June 3, 1974 [21] Appl. No.: 475,759 [57] ABSTRACT A resettable register mechanism having a register with a plurality of coaxial number wheels of ascending or- [52] US. Cl 235/144 ME; 235/144 D def, a bidirectional rotary electrical Stepping motor [51] hit. CI.2 15/42 adapted to be electrically pp vin one angular [58] of Searchm" 235/144 144 144 rection for indexing the number wheels to register suc- 235/132 132 E cessive numerical counts and to be electrically stepped in the opposite angular direction for indexing [5 61 References cued the lowest order number wheel to zero and for operat- UNITED TA E PATENTS ing a heart cam reset mechanism for resetting the re- 2,544,610 3/1951 Nelson 235 144 ME- maining high r r r number wheels to r 3,040,981 6/1962 Bram 235/144 R 9 C] 4 Dr F, 3,187,945 6/1965 Wright et al. 235 144 E aw'ng guns PATENIEBSEP 1's M5 3 9 O6 2 O6 SHEET 2 [IF 3 PATENTEUSEPISIBYS 3808206 SHEET 3 [IF 3 RESE'ITABLE REGISTER MECHANISM BRIEF SUMMARY OF THE uvvizivriou a register with a plurality of coaxial number wheels of increasing order adapted to be indexed for registering successive numerical counts and a reset mechanism for resetting the number wheels to zero, and more particularly to a new'and improved resettable register mechanism having a drive motor selectively operable for indexing the register to successive registrations or for resetting the register to a predetermined registration.

It is a principal aim of the present invention to provide a new and improved resettable register mechanism having a new and improved motor drive mechanism selectively operable for indexing the register for registering successive numerical counts'and for resetting the register to zero.

It is another aim of the present invention to provide a resettable register mechanism having a new and improved stepping motor drive arrangement employing a stepping motor operable in one direction for indexing the register to successive registrations and in the opposite direction for resetting the register to a predetermined registration.

It is a further aim of the present invention to provide a resettable register mechanism having a new and improved motor driven mechanism for resetting the register.

It is a still further aim of the present invention to provide a new and improved resettable register mechanism which is operable as a readout device in a gasoline or other fluid dispensing system for registering the cost and/or volume amount of fluid delivered and which is useful as a local or remote readout device as may be desired.

It is another aim of the present invention to provide a new and improved drive mechanism for a counter type register for selectively indexing the counter for accumulating a count and for resetting the counter.

,It is a further aim of the present invention to provide a new and improved register reset mechanism for a register of the type having a plurality ofcoaxial counter wheels and employing a reset drive motor which may be operated for sequentially disengaging the counter wheelsto condition them for being reset, resetting the counter wheels and conditioning the counter wheels for counting Other aims will be in part obvious and in part pointed out more in detail hereinafter. I

i The invention accordingly consists in the features of construction, combination of elements and arrangements of parts which will be exemplified in the construction hereafter set forth and the scope of the application wliich will be indicated in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS In; the drawings: 7 v I FIG. 1 is a front view, partly broken away and partly in section, of a resettable register mechanism incorpobroken away and partly in section, taken substantially along line 33' of FIG. 1, additionally showing a cam track of the register mechanism in broken lines; and

FIG. 4 is an enlarged partial transverse section view, partly in section, of the register mechanism of FIG. 1 showing a side view of a counter wheel thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring nowto the drawings in detail, wherein like numerals represent like parts, a" resettable register mechanism incorporating an embodiment of the present invention is shown comprising a register or counter 8 having a plurality of coaxial register or

number wheels

10, 12, 14, 16 of ascending order mounted on a counter shaft 21 rotatably supported on a suitable frame 22.

The register 8 is adapted to be indexed by operation of a suitable bidirectional electrical stepping motor 20 in one angular direction, in the clockwise direction as viewed in FIGS. 2 and 3-, to display successive numerical counts or registrations in appropriate number wheel windows 2. A compound gear 24 mounted on a motor v shaft 26 has a relatively large gear 28 in engagement with a wheel drive gear 30 of the lowest order number wheel 10. The gear ratio of the

gears

28, 30 is preferably such that one step of the stepping motor, in the clockwise direction as viewed in FIGS. 2 and 3, is operable to index the lowest order counter wheel 10 one count or graduation, 3.6 in the shown embodiment where the lowest order counter wheel 10 bears one hundred graduations representing 0-99 counts respectively and where the remaining higher order counter wheels 12, 14, 16 bear ten graduations or sequence of numerals 0-9. The stepping motor 20 is, for example, a four phase bidirectional stepping motor in which the motor shaft 26 is indexed 7.5 for each electrical operating pulse to the motor (i.e. 48 steps per motor revolution), in which event the

gears

28, 30 preferably provide a 12:25 gear reduction for indexing the lowest order counter wheel 10 one count or 3.6 for each step of the drive motor 20.

The

counter wheels

10, 12,14, 16 comprise suitable indicia or register wheel members 40; heart reset cams 41 on the higher order count wheels 12, 14,' 16; combined locking ring and transfer gear sectors 42 on the lower order counter wheels 10, 12, 14; and wheel driving gears 30 on all the counter wheels 10, 12, 14, .16.

In a conventional manner, mutilated transfer pinions 44 rotatably mounted on a transfer pinion shaft 46 are provided between adjacent counter wheels for indexing each higher order counter wheel one count or registration for each revolution of the adjacent lower order counter wheel in the conventional manner as the adjacent lower order counter wheel is indexed the last 36 from 9 to 0, or to 00 in the case of the lowest order counterwheel 10. The mutilated transfer pinions 44 have in a conventional manner alternate, relatively long and

short teeth

48, 49 respectively, to provide for gears, and the transfer pinions 44 function as intermediate gears interconnecting the drive and driven gears.

A reset finger comb 74 fixed ,on a rotatable reset finger shaft 75 has three axially spaced reset fingers 76 and is adapted to be pivoted against the bias of a tension spring 78 for pivoting the reset fingers 76 into engagement with respective heart cams 41 of the higher order counter wheels 12, 14, 16 for resetting those wheels to zero.

The register 8 shown incorporates a wheel disengagement mechanism 58 of the type disclosed in US. Pat. No. 3,456,877 of M. S. Juhas, dated July 22, 1969 and entitled Counting Mechanism, and therefore the wheel disengagement mechanism 58 will not be described in detail. Briefly, however, the combined locking ring and transfer gear sectors 42 are formed separately from and are controllable independently of the respective indicia wheels 40, and the remaining parts of each counter wheel (i.e., gear 30, heart cam 41 and indicia wheel 40) are integrally formed together. Referring to FIG. 4, the combined locking ring and transfer gear sector 42 is keyed to the indicia wheel 40 by a pin 60 on the combined locking ring and transfer gear sector 42 and received within a generally radial and slightly arcuate slot 91 in the indicia wheel 40. The combined locking ring and transfer gear sector 42 is rotatably supported on an eccentric bearing or journal 64 mounted on the counter wheel shaft 21 and suitably keyed thereto.

' With the counter wheel shaft 21 in its normal angular position shown in FIGS. 2 and 3, as the indicia wheel 40 is rotated on the shaft 21, the respective combined locking ring and transfer gear sector 42 rotates with the indicia wheel 40 but about the axis of the eccentric 64.

- Also, by rotation of the shaft 21, the eccentric 64 is rotated to shift the axis of the combined locking ring and transfer gear sectors 42 with respect to the transfer pinions 44 and thereby disengage the counter wheels for conditioning them to be reset. Although complete disengagement of the counter wheels requires that the counter wheel shaft 21 be rotated approximately 120, in the clockwise direction as viewed in FIGS. 2 and 3, from its normal or counting position shown in FIGS. 2 and 3, the wheels are gradually disengaged as the shaft 21-is rotated, thereby permitting the reset action with the fingers 76 to commence before the counter wheels are completely disengaged. Accordingly, the reset cycle can be programmed to commence the pivotal movement of the reset fingers 76 before and to complete their pivotal movement for resetting the counter wheels afterthe wheels are completely disengaged.

After the wheels l0, 12, 14, 16 have been reset, the shaft 21 is angularly returned, in the counterclockwise direction as viewed in FIGS. 2 and 3, to its normal angular position shown, to re-engage the transfer drives between the number wheels.

In accordance with the present invention, the bidirectional stepping motor is adapted to he stepped in the reverse angular direction, in the counterclockwise direction as viewed in FIGS. 2 and 3, for resetting the

register wheels

10, 12, 14, 16 to zero. For this purpose, the bidirectional stepping motor 20 is connected for rotating a reset control rotor 80, in the clockwise direction as viewed in FIGS. 2'and 3, via a relatively small gear 82 of the compound gear 24, an input gear 84 of a one-way drive mechanism 86, an output gear 88 of the one-way mechanism 86, an idler gear 90, and a rotor drive gear 91. The one-way drive mechanism 86 comprises a drive pawl 92 pivotally mounted on the input gear 84 and spring biased into engagement with a driven ratchet wheel or hub 94 affixed to the driven gear 88. The ratchet wheel 94 has a single notch or tooth 96 whereby the pawl 92 is engageable for rotating the ratchet wheel 94 and output gear 88, in the clockwise direction as viewed in FIGS. 2 and 3, from their normal or rest angular positions shown in FIGS. 2 and 3. Also, the single ratchet wheel teeth 96 is angularly positioned and the

gears

82, 84 provide a gear reduction (12:25 in the described example) so that, as the stepping motor 20 is indexed in its reverse angular direction for resetting the register wheels to zero, the pawl 92 engages the tooth 96 to commence rotating the reset control rotor when the lowest order number wheel 10 is at its zero position. As will beexplained more fully hereinafter after the pawl 92 engages the tooth 96, the bidirectional stepping motor 20 continues to be stepped in its reverse direction for indexing the reset control rotor 80, in the clockwise direction as viewed in FIGS. 2 and 3, one full revolution for resetting the higher order counter wheels l2, l4, 16 to zero. While the reset control rotor 80 is rotated one full revolution, the lowest order counter wheel 10 is rotated five full revolutions by the stepping motor 20 and such that the lowest order counter wheel 10 ends at its zero position at the end of the reset cycle of the reset control rotor 80, at which point all of the register wheels 10,,

l2, l4, l6 are reset for a subsequent counting or registration cycle. Thus, the drive ratio employed for rotating the reset control rotor 80 is one-fifth the drive ratio employed for indexing the register for accumulating a count and such that the reset control rotor 80 is driven with sufficient torque to perform its various reset functions to be described.

The reset control rotor80 comprises a reset finger control cam 96 on one side of its drive gear 91 and a generally heart shaped cam track 98 (shown in part in dotted lines in FIG. 2 and in phantom lines in FIG. 3) on the opposite side of itsdrive gear 91. A first pivotal lever 100 having a follower roller 102 in engagement with the cam 96 is connected via a slot 104 and roller pin 106 to a lever 108 keyed to the reset finger shaft 75. A second pivotal lever 112 having a follower 114 received in the cam track 98 has a gear segment 116 in mesh with a gear 118 keyed to the counter wheel shaft 21 for rotating the shaft 21 for disengaging the counter wheels10, 12, 14, 16 as described. The reset finger control cam 96 and the cam track 98 are preferably designed so that as the reset control rotor 80 is rotated one revolution, in the clockwise direction as viewed in FIGS. 2 and 3, the reset action of the reset finger comb 74 is initiated substantially at the beginning of the reset cycle and is completed just prior to the end of the reset cycle, and the higher order counter wheels 12, 14, 16 are held by the reset fingers 76 at their reset or 0 positions until'near the end of the reset cycle and until the transfer pinions 44 are re-engaged by the combined locking ring and transfer gear segments 42, whereupon the follower 102 drops off the peak of the cam 96 to provide for withdrawal of the reset finger comb 74 by the return spring 78.,The counter wheel shaft 21 is rotated, clockwise as viewed in FIGS. 2 and 3, approxiwheels, is retained in that withdrawn angular position while the higher order counter wheels 12, l4, 16 are" reset-and is then rotated in the opposite angular direc tion during approximately the last 6070f rotation of the reset control rotor 80 to re-e ngage the counter wheels after they have been fully reset by the reset fingers 76. Accordingly, the

cams

96, 98 are contoured to ensure smooth and synchronous disengagement of the wheels, wheel resetting with the reset fingers 76 vand reengagement of the wheels after they are reset, all during one revolution of the reset control rotor 80.

A number wheel shutter 120 pivotallymounted on the wheel shaft 21, is connected to the lever 112 by a slot 122 in one side of the shutter 120 and a roller pin 124 on the lever 112 for pivoting the shutter 120,

clockwise as viewed in FIG. 3,'to cover the counter wheel windows during the. reset operation and such that the register'is not readable during reset. The shutter 120 is then withdrawn by the lever 112 at the end of the reset cycle to permit reading the register wheels after they are fully reset.

The reset cycle is positively terminated by the engagement of a pin. 130 on the lowest order counter wheel gear 30 with an inturned flange or lip 132 of an abutment lever 134. The abutment lever 134 is affixed to the pinion shaft 46, and an abutment control lever 138 (FIG. 2), also affixed to the transfer pinion shaft 46, is provided for selectively pivoting the abutment lever 134 into alignmentwith the stop pin 130. In. this regard, at the completion of a reset cycle, the abutment and control levers 134, 138 are. in their positions shown inFlGS. 2 and 3.During the subsequent operation of the register to accumulate a count, as the lowest order counter wheel is indexed'by the motor 20, in the counterclockwise direction as viewed in FIGS. 2 and 3, the stop pin 130 engages the side of abutment'lever flange'l32 to pivot the abutment lever 134 to awithdrawn position where it is held by the engagement of a leaf spring detent 140-with a notched end 142 of-the controllever '138. The abutment lever 130 remains in that withdrawn position during the subsequent operation ofthe register. r

During the succeeding reset cycle, a pin 144 on the reset control rotor 80 engages the tail 146 of the control lever 138 to pivot the abutment lever 134 to its position shown in FIG. 3 where it is also held by the engagement of the leaf spring 140 with the notched end 142 of lever 138. The abutment lever 134 is so pivoted to its stop position shown by the pin 144 approximately 45 before the end of the rotor reset cycle and therefore after the lowest order register wheel 10 is indexed beyond its zero position immediately preceding its final reset or zero position.

The pivotal retraction of the abutment lever 134 by the pin 130 occurs as the lowest order register wheel 10 is indexed from its 80 to its 90 position and therefore before the next higher order register wheel 12 is indexed via the respective transfer pinion 44. Accordingly, if the register is reset before the first wheel 10 is indexed beyond approximately its 90" position (and therefore before the abutment lever 134 is retracted by the pin 130), the first wheel 10 would merely be indexed in the reverse direction back to zero by the motor 20, where the abutment lever 134 would stop the first wheel 10 against further reverse rotation. The reset control rotor 80 would not then be rotated by the motor since the one-way drive mechanism 86 is not engaged until the first wheel 10 is returned to its zero position.

, Itcan therefore be seen that in accordance with the present invention a single bidirectional stepping motor drive is adapted to be selectively operated for indexing the register 8 for displaying successive registrations and for resetting the register. Also, the register wheels are positively reset to zero and the reset cycle is automatically and positively terminated, thus permitting the electrical bidirectional stepping motor to be additionally electrically pulsed to ensure full and proper resetting of the number wheels without possibility of overrun. Further, the mechanical drive between the bidirectional motor lowest order counter wheel 10 is not disengaged for resetting purposes and whereby an additional disengagement clutch is not required and the correct drive relationship between the bidirectional stepping motor and the register is maintained for subsequent registration cycles.

As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of the present invention.

Iclaim:

1. In a resettable register mechanism having a resettable register with a plurality of rotary register wheels of ascending order and adapted to be. indexed to suecessive registrations thereof by indexing. its lowest order register wheel in one angular directionthereof, and register wheel reset means having a rotary input and operable by rotation of its rotary input in a reset angular direction thereof for resetting the remaining higher order register wheels to respective reset angular positions thereof; and a motor drive mechanism connected to the lowest order register wheel and operable for indexing the lowest order register wheel in its said one angular direction for indexing the register to successive registrations thereof, theimprovement wherein the motor drive mechanism comprises a bidirectional electrical rotary stepping motor adapted to be selectively angularly stepped in each angular direction thereof, first drive meansconnecting the. bidirectional rotary stepping motor to the lowest order. register wheel for indexing the lowest order wheel in each angular direction thereof with the stepping motor in accordance with the angular direction and number of steps of operation of the stepping motor whereby the rotary stepping motor is adapted to be selectively electrically stepped in one angular direction thereof for selectively indexing the lowest order register wheel in its said one angular direction for selectively indexing the-register to successive registrations thereof and to be selectively electrically stepped in a reverse reset angular direction thereof for indexing the lowest order counter wheel in an opposite reset angular direction to a reset angular position thereof, and second drive means connecting the bidirectional stepping motor to said rotary input of the reset means for indexing said rotary input in its said reset angular direction with the bidirectional stepping motor as it is stepped in its reset angular direction for concurrently resetting the remaining higher order register wheels with the lowest order wheel to their respective reset angular positions.

2. A resettable register mechanism according to claim 1 wherein the register wheel reset means comprises reset terminating means for automatically terminating the stepping motor rotation in its reset angular direction with all of said register wheels in their respective reset angular positions.

3. A resettable register mechanism according to claim 1 wherein the registeif wheel reset means comprises one way drive means automatically engaged for automatically resetting said remaining higher order register wheels with the bidirectional rotary stepping motor and via the rotary input as the motor is stepped in its reset angular direction.

4. A resettable register mechanism according to claim 3 wherein the'one way drive means is automatically engaged as said lowest order register wheel is indexed in its reset angular direction and at its reset angular position. i

5. A resettable register mechanism according to claim 1 wherein the register reset means comprises a reset control rotor connected to said rotary input to be indexed in one angular direction thereof by the bidirectional stepping motor as it is stepped in its reset angular direction, and wheel resetting means operable by the reset control rotor as it is rotated 360, in its said one angular direction for resetting said remaining higher order register wheels.

6. A resettable register mechanism according to claim 5 wherein the reset control rotor is connected to be indexed by the stepping motor as it is stepped in its reset angular direction at an angular rate which is a 1/a fraction, where a is a whole number greater than 1, of the angular rate the lowest order register wheel is indexed in its said one angular direction by the stepping motor.

7. A resettable register mechanism according to claim 2 wherein the reset terminating means comprises positive stop means for positively stopping the stepping motor rotation in its reset angular direction with all of the register wheels in their respective reset angular positions.

8. A resettable register mechanism according to claim 7 wherein the positive stop means comprises first stop means rotated by the stepping motor as it is stepped in its reset angular direction, and second shiftable stop means adapted to be selectively shifted between a firstextended position engageable by the first stop means'to stop the rotation of the motor in its reset angular direction when the lowest order register wheel reaches its reset angular position and a second withdrawn position out of engagement by the first stop means, and shifting means for automatically shifting the second shiftable stop means to its said extended position as the stepping motor is stepped in its reset angu lar direction and for automatically shifting the shiftable stop means to its withdrawn position as the motor is stepped in its said one angular direction to index the register to successive registrations thereof.

9. In a resettable counter mechanism having a resettable counter with a plurality of rotary counter wheels of ascending order and adapted to be indexed to successive'counts by indexing its lowest order counter wheel in one angular direction thereof, and a counter drive mechanism connected to the resettable counter and alternatively operable for indexing the lowest order counter wheel in its said one angular direction for indexing the counter to successive counts and for reset ting the counter wheels to respective reset angular positions thereof; the improvement wherein the counter drive mechanism comprises a bidirectional electrical rotary stepping motor adapted to be selectively angularly stepped in each angular direction thereof, first drive means connecting the bidirectional stepping motor to the lowest order wheel for indexing the lowest order wheel in each angular direction thereof with the stepping motor in accordance with the angular direction and number of steps of operation of the stepping motor whereby the electrical stepping motor is adapted to be selectively electrically stepped in one angular direction thereof for selectively indexing the lowest order counter wheel in its said one angular direction for selectively indexing the counter to successive counts, and second drive means connecting the bidirectional electrical stepping motor to the resettable counter for resetting the remaining higher order counter wheels with the stepping motor as it is stepped in a reverse reset angular direction thereof for concurrently resetting the remaining higher order counter wheels with the lowest order wheel to their respective reset angular positions.

Claims

1. In a resettable register mechanism having a resettable register with a plurality of rotary register wheels of ascending order and adapted to be indexed to successive registrations thereof by indexing its lowest order register wheel in one angular direction thereof, and register wheel reset means having a rotary input and operable by rotation of its rotary input in a reset angular direction theReof for resetting the remaining higher order register wheels to respective reset angular positions thereof; and a motor drive mechanism connected to the lowest order register wheel and operable for indexing the lowest order register wheel in its said one angular direction for indexing the register to successive registrations thereof, the improvement wherein the motor drive mechanism comprises a bidirectional electrical rotary stepping motor adapted to be selectively angularly stepped in each angular direction thereof, first drive means connecting the bidirectional rotary stepping motor to the lowest order register wheel for indexing the lowest order wheel in each angular direction thereof with the stepping motor in accordance with the angular direction and number of steps of operation of the stepping motor whereby the rotary stepping motor is adapted to be selectively electrically stepped in one angular direction thereof for selectively indexing the lowest order register wheel in its said one angular direction for selectively indexing the register to successive registrations thereof and to be selectively electrically stepped in a reverse reset angular direction thereof for indexing the lowest order counter wheel in an opposite reset angular direction to a reset angular position thereof, and second drive means connecting the bidirectional stepping motor to said rotary input of the reset means for indexing said rotary input in its said reset angular direction with the bidirectional stepping motor as it is stepped in its reset angular direction for concurrently resetting the remaining higher order register wheels with the lowest order wheel to their respective reset angular positions.

3. A resettable register mechanism according to claim 1 wherein the register wheel reset means comprises one way drive means automatically engaged for automatically resetting said remaining higher order register wheels with the bidirectional rotary stepping motor and via the rotary input as the motor is stepped in its reset angular direction.

4. A resettable register mechanism according to claim 3 wherein the one way drive means is automatically engaged as said lowest order register wheel is indexed in its reset angular direction and at its reset angular position.

5. A resettable register mechanism according to claim 1 wherein the register reset means comprises a reset control rotor connected to said rotary input to be indexed in one angular direction thereof by the bidirectional stepping motor as it is stepped in its reset angular direction, and wheel resetting means operable by the reset control rotor as it is rotated 360* in its said one angular direction for resetting said remaining higher order register wheels.

8. A resettable register mechanism according to claim 7 wherein the positive stop means comprises first stop means rotated by the stepping motor as it is stepped in its reset angular direction, and second shiftable stop means adapted to be selectively shifted between a first extendeD position engageable by the first stop means to stop the rotation of the motor in its reset angular direction when the lowest order register wheel reaches its reset angular position and a second withdrawn position out of engagement by the first stop means, and shifting means for automatically shifting the second shiftable stop means to its said extended position as the stepping motor is stepped in its reset angular direction and for automatically shifting the shiftable stop means to its withdrawn position as the motor is stepped in its said one angular direction to index the register to successive registrations thereof.

9. In a resettable counter mechanism having a resettable counter with a plurality of rotary counter wheels of ascending order and adapted to be indexed to successive counts by indexing its lowest order counter wheel in one angular direction thereof, and a counter drive mechanism connected to the resettable counter and alternatively operable for indexing the lowest order counter wheel in its said one angular direction for indexing the counter to successive counts and for resetting the counter wheels to respective reset angular positions thereof; the improvement wherein the counter drive mechanism comprises a bidirectional electrical rotary stepping motor adapted to be selectively angularly stepped in each angular direction thereof, first drive means connecting the bidirectional stepping motor to the lowest order wheel for indexing the lowest order wheel in each angular direction thereof with the stepping motor in accordance with the angular direction and number of steps of operation of the stepping motor whereby the electrical stepping motor is adapted to be selectively electrically stepped in one angular direction thereof for selectively indexing the lowest order counter wheel in its said one angular direction for selectively indexing the counter to successive counts, and second drive means connecting the bidirectional electrical stepping motor to the resettable counter for resetting the remaining higher order counter wheels with the stepping motor as it is stepped in a reverse reset angular direction thereof for concurrently resetting the remaining higher order counter wheels with the lowest order wheel to their respective reset angular positions.