US3722795A - Division control mechanism - Google Patents

Abstract

A device for momentarily stopping a calculating machine comprising clutch for releasably connecting a motor shaft with the main shaft of the machine. A link mechanism to be actuated by the last step of the tabulating stroke of a carriage in division operation is provided to cause the clutch to operatively connect the motor shaft with the main machine shaft only after the completion of the tabulating stroke for thereby ensuring that a sufficient safety time is provided between the completion of the tabulating stroke and the start of the operation of the machine.

Description

United States Patent 1 Barozzi et al.

[ 1 Mar. 27, 1973 l54| DIVISION CONTROL MECHANISM [75] inventors: Gian Piero Barozzi; Giancarlo I-Ioreschi, both of Crema, Italy [73] Assignee: Citizen Watch Co., Ltd., Tokyo,

Japan [22] Filed: Feb. 8, 1971 [21] Appl. No.: 113,586

[30] Foreign Application Priority Data Feb. 11, 1970 Italy ..20470 A/7O [52] [1.8. CI ..235/62 F, 235/60 R [51] Int. Cl. ..G06c 23/00 [58] Field of Search ..236/60 R, 60 M, 62 R, 62 F, 236/60.49

[56] References Cited UNITED STATES PATENTS 2,854,190 9/l958 Bogert ..235/60.49

8/1966 Gang ..235/62 F X 3/1970 Busch ..235/62 F X Primary Examiner-Richard B. Wilkinson Assistant ExaminerStanley A. Wal Att0mey--William D. Hall, Elliott I. Pollock, Fred C. Philpitt, George Vande Sande, Charles F. Steininger and Robert R. Priddy [57] ABSTRACT A device for momentarily stopping a calculating machine comprising clutch for releasably connecting a motor shaft with the main shaft of the machine. A link mechanism to be actuated by the last step of the tabulating stroke of a carriage in division operation is provided to cause the clutch to operatively connect the motor shaft with the main machine shaft only after the completion of the tabulating stroke for thereby ensuring that a sufficient safety time is provided between the completion of the tabulating stroke and the start of the operation of the machine.

4 Claims, 5 Drawing Figures mllii Patented March 27, 1973 3,722,795

3 Sheets-Sheet 1 Patented March 27,1973 8, 2 7 5 I s sheets-sheet s DIVISION CONTROL MECHANISM BACKGROUND OF INVENTION The present invention relates to a device for use with a calculating machine and, more particularly, to a device for momentarily stopping a calculating machine in the course of a division operation until a motion of the setting carriage of the machine is completed to thereby ensure that a sufficient stop or safety time is provided between the completion of a tabulating motion of the carriage for the divisor digits entered into the machine and the start of the operation of the machine so that the operation of the machine is again started only after the completion of the tabulating motion of the-carriage.

It is well known that, in conventional calculating machines, the carriage is moved step by step while the divisor digits are entered or set. In order to allow the carriage and the calculating section of a calculating machine to perform the tabulating stroke and the calculation of set figures, respectively, a supplementary waiting or safety time within which the carriage surely completes the tabulating stroke is provided in the heretofore-known calculating machine. In fact, the carriage motion is caused only by the resilient action of a return spring and depends upon the condition of the spring and upon the condition of guide ways on which the carriage slides, such as the degree of the surface finishing of the guide ways and the condition of the lubricant on the guide ways and so on. For this reason, there is no assurance that the motion of the carriage is completed in a predetermined time, i.e., always sin the same period of time.

In some known calculating machines, the above problem is solved by causing the machine to operate very slowly so that a sufficient time is provided for the completion of carriage motion. This solution, however, has the major disadvantages that the machine is incapable of performing quick calculating operations and, in addition, that there is no assurance that a calculating operation of the machine is restored after the completion of carriage motion. Stated in other words, while calculating machines of some known types are designed to have a sufficient time for the carriage motion, there nevertheless exists a possibility that such motion will be not completed within the given time, i.e., that the calculating operation of the machine is started before the carriage has completed its stroke.

It is a primary object of the present invention to eliminate the afore-stated drawbacks in the art of calculating machines.

It is another object of the present invention to provide a device for use with a calculating machine which device will ensure that a carriage stroke is wholly performed at the speed allowed by a return means and that a calculating operation of the machine is started only after the completion of a carriage stroke, i.e., the start of machine operation depends upon the completion of a carriage stroke.

SUMMARY OF THE INVENTION According to the present invention, there is provided a device for momentarily stopping a calculating machine comprising clutch means for releasably connecting a motor shaft with the main shaft of said machine, means for controlling the engagement and disengagement of said clutch means, said clutch means being designed to have two disengaged positions one of which occurs at the end of all machine operations and the other of which occurs in the course of the division operation of the machine, the latter disengaged posi tion being maintained through the whole carriage stepping time required for the tabulation of the divisor, said clutch means being reengaged by the last tabulation step of said carriage to thereby ensure that the operation of the machine is restored only after the end of the tabulation stroke of said carriage.

In a preferred embodiment of the invention, the clutch means may consist of teeth carried by the motor shaft and a pawl carried by the main shaft of the machine. The clutch means may be disengaged by means operatively connected to a division operation starting key. The last-mentioned means may comprise a link mechanism.

The above and other objects and features of the invention will become apparent from the following description of a preferred embodiment of the invention with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view of the device according to an embodiment of the present invention with the components of the device being shown in their inoperative positions;

FIG. 2 is a view similar to FIG. 1 but illustrating the components in their operative positions; and

FIGS. 3a, 3b and 3c are sections taken along line III III in FIG. 1 in different operating positions of the same components.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIGS. 1 and 2 of the drawings, the machine comprises a conventional keyboard with numbered keys, not shown, to be actuated to operate different components of the machine through levers and transmissions; in particular, the components shown in the drawings are actuated by the key marked in the division operation of machine by a force exerted in the direction of arrow F. In more detail, the force is exerted on a lever l which is guided by a pin 2 along a slot 3 in the lever to move substantially in a direction parallel to the direction of the arrow F, thus shifting a pin 4 by which the lever l is connected with one end of a lever or bellcrank 5 which in turn is pivotally mounted on a fixed shaft 6. The bell crank 5 has its other end 7 pivotally connected by a pin 8 to one end of a slider 9. Slider 9 is guided by stationary supports 10 and is retained in the left hand or rest position, as viewed in FIG. I, by a tension spring 11 which extends between a pin 12 on the slider 9 and a stationary machine part 13.

Secured to the other end of the slider 9 is a pin 14 by which a lever 15 is pivotally connected substantially at the intermediary of the ends thereof to the slider 9. The right hand arm of the lever 15 is formed with a tongue 16 while the left hand arm is formed with a recess 17 and a bearing face 18. The recess 17 is designed to be engaged by a tongue 19 projecting out of a lever 20 which is hinge-connected as at 21 with a second bell crank 22 which in turn is pivotally mounted on a stationary shaft 23, the lever 20 being urged upwardly by a tension spring 24 having its opposite ends secured respectively to a stationary machine part 25 and to a portion of the lever 20 adjacent the upper end thereof.

The lever 20 is formed at the upper end portion with a window 26 in which a free end 27 of an arm ofa third bell crank 28 is engaged. The bell crank 28 has another arm 30 the free end 31 of which is adapted to operate a pawl 32 which is pivotally mounted by a pin 38 on a disk 33 which in turn is secured to a main shaft 34 of the machine, said pawl being designed to get engaged with teeth of a joint 35 mounted on a shaft 36 which is driven by a motor 37.

Referring next to FIGS. 3a to 3c of the drawings, the pawl 32 is always biased by a spring 39 in the direction of engagement of the pawl with the teeth of the joint 35 on the shaft 36. Such engagement of the pawl, however, is normally prevented by a main control member 40 which may be of conventional type and which can be operated by any key of the machine. The main control member 40 will release the pawl 32 when the member 40 is moved out of a notch 41 formed in the disk 33 at the same level of control arm 32a of the pawl 32.

Referring back to FIGS. 1 and 2, the lever 20 is normally in engagement at a projection 43 with a stationary stop 42 so that the lever 20 cannot be further swung leftwards as viewed in these figures, while it is free to swing rightwards by the action of the left side face of the recess 17 in the lever 15. The projection 43 rests on the stationary stop 42 when the lever 20 is swung leftwards and is lifted to a position shown in FIG. 2. The projection 43 is also designed to prevent the lever 20 from being lifted by the spring 24 when the lever 20 is not acted upon by the recess 17 in the lever (see FIG. 1).

The calculating machine also comprises a carriage 44 of an already known type, the carriage having conventional stops 45 which, when engaged with a stationary stop 46, will prevent the carriage from being moved leftwards by the action of spring 53. The stops can be shifted by means ofa projection 47 extending laterally from one end portion 49a of a lever 48 which is pivotally mounted on a stationary shaft 49 and is biased to swing in counter-clockwise direction by a spring 50 extending between the other end 49b of the lever 48 and the end 51 of a lever 52. Lever 52 is hinged to the lever 48 by means of a pin 54 thereon and a slot in the lever 52. The lever 48 is biased clockwise by a spring 55 which extends between the end 49a of the lever 48 and a stationary machine part. Formed on the projection 47 of the lever 48 is an inclined portion 47a with which the stops 45 are successively brought into slidable engagement at lateral extensions 45a thereof. The lever 52, which would tend to swing in clockwise direction under the bias of spring 50, is retained by a lateral projection 56 on the upper end of the lever 52 which projection is engaged with the upper end portion of the lever 20 to prevent any clockwise movement of the lever 52. The latter is also formed with a dog 57 which is positioned in front ofa motion bar 58 of the machine which can be moved in a direction indicated by arrow H (FIG. 1).

The bell crank 22, which is pivotally mounted on the fixed shaft 23, is rotated in the direction of arrow M by the carriage 44 when the latter is moved leftwards by the spring 53 to a position corresponding to the last column, as shown in dotted line in FIG. 1. The carriage 44, when moved to said position, urges an arm 22a of the bell crank 22 so that the same is swung in the direction of the arrow M.

The operation of the device according to the abovedescribed embodiment of the invention is as follows:

After a divisor is set on the machine in the division operation, the key is depressed so that a motion in the direction of the arrow F is imparted to the slider l to turn the bell crank 5 about the pin 6. The slider 9 slidably extending through the supports 10 will accordingly be moved rightwards as indicated by an arrow G by the pin 8 secured to the arm 7 of the bell crank 5. This movement of slider 9, in turn, causes the lever 15 to be moved rightwards to bring the left side face of the recess 17 in the lever 15 into engagement with the tongue 19 of the lever 20 so that lever 20 is swung rightwards or in clockwise direction about the pin 21. This motion causes the projection 43 to slide along the underside of the fixed stop 42 until the projection is disengaged from the stop, whereby the lever 20 is allowed to be lifted by the spring 24, causing a rotation of the bell crank 28 about the shaft 29 due to the fact that the arm 27 of the bell crank 28 is engaged into the window 26 in the lever 20. This rotation of the bell crank 28 causes the other arm 30 thereof to bring its tongue 31 into engagement with the peripheral edge of the disk 33, as shown in FIG. 3b. The inoperative position of the bell crank 28 is shown in FIG. 3a.

Simultaneously with the depression of the key, the control member 40 is cleared in conventional manner, i. c. said stop is lifted from the notch 41 in the disk 33 to thereby disengage from the disk and also to release the pawl 32. Thus, the pawl 32 is urged by the spring 39 into engagement with a recess defined between an adjacent pair of the teeth of the joint 35 on the motor shaft 36. As a result, the disk 33 is operatively or drivingly connected with the motor shaft 36 by the pawl 32 and the teeth of the joint 35 and, thus, the torque of the motor 37 is imparted to the main shaft 34 since the motor 37 has already been startedby the depression of the key.

Under such condition, the disk 33 is rotated together with the shaft 36 until the notch 41 is reached by the free end 31 of the bell crank 28 which is biased toward the center of the disk 33 by the spring 24 through the lever 20 as will be seen in FIG. 1. As soon as the mentioned position is attained by the notch 41, the end 31 of the bell crank 28 springs thereinto, engages with the radial portion of the notch, and thus stops the disk 33.

In the course of the above motion, the end 31 of the bell crank 28 comes into contact with the extension 32a of the pawl 32 at a time slightly in advance of the stoppage of the disk 33, thus causing the pawl to be rotated about its pin 38 against the spring 39 and to disengage from the teeth of the joint 35. The disk 33, therefore, is disconnected from the shaft 36 and the machine is stopped. The resultant position is shown in FIG. 30.

Owing to the clockwise movement of the lever 20, the projection 56 on the upper end of the lever 52 which has been in engagement with the lever 20 is disengaged therefrom, allowing the lever 52 to be swung by the spring 50 in clockwise direction about the pin 54 on the lever 48 until the dog 57 is moved to a position under the motion bar 58. Immediately thereafter, the bar 58 is moved downwardly to downwardly shift the lever 52 along the pin 54 to stretch'the spring 50 and cause the extension 49b of the lever 48 to swing in the direction of arrow N. As a result, the projection 47 of the lever 48 operates at its inclined plane 47a to lift the stops 45 one at a time with the aid of the lateral extensions on the stops 45 until each stop is cleared from the stationary stop 46, thus allowing the carriage 44 to have a step of leftward movement by the action of the spring 53. The above operation is repeated for all of the stops 45 until the end of the movement as indicated by broken line in FIG. 1 is attained by the carriage 44, at which time the latter comes into engagement with the arm 22a of the bell crank 22 to cause same to be swung in the direction of arrow M.

FIG. 2 illustrates the position wherein the lever 52 is in engagement with the bar 58, the projection 43 on the lever is in engagement with the fixed stop 42 and the lever 48 is swung about the pin 49.

The rotation of the bell crank 22 in the direction of arrow M caused by the last step of the carriage 44, as described in the above, results in a downward motion of the lever 20 and, thus, in a disengagement of the projection 43 from the fixed stop 42, so that the projection 43 is allowed to return to its rest position under the fixed stop 42 as shown in FIG. 1. Concurrently with this downward motion, the free end 27 of the bell crank 28 is pulled downwardly to cause the latter to be swung about the shaft 29 for thereby lifting the other end 31 of the bell crank 28 back to the position as shown in FIG. 3a, i.e. the above of the disk 33 and out of contact therewith.

By the lifting of the end 31 of the bell crank 28 from the disk 33, the pawl 32 is also disengaged from the end 31 and brought into engagement with the joint 35 by the action of the spring 39, whereby the disk 33 is restored until the whole division operation is performed.

At the end of the above described sequence of cycles, the main control member is engaged again into the notch 41, thus disengaging the machine from the motor shaft 36 and consequently stopping all components thereof.

What is claimed is:

1. In a calculating machine having a setting carriage, a main shaft, and a motor for driving said main shaft, a clutch between the shaft of said motor and said main shaft, means for operating said clutch to its engaged condition at the start of any machine operation, said clutch normally being maintained in its engaged condition until the completion of all machine operations, and

a mechanism for momentarily interrupting drive from said motor shaft to said main shaft during performance of a division operation by said machine to provide a safety time between the completion ofa tabulating motion of said carriage and the subsequent start of operation of said machine, said mechanism including control means jointly responsive to commencement of said division operation by said calculating machine and to subsequent rotation of said motor shaft to a predetermined position for disengaging said clutch, means for retaining said clutch in its disengaged condition as said carria e effects a stepping motion required for the tabula ion of a divisor in said division operation, and

resetting means responsive to completion of said carriage stepping motion for actuating said control means to effect re-engagement of said clutch.

2. The combination of claim 1 wherein said clutch comprises a toothed member on said motor shaft and a pawl on said main shaft, resilient means normally urging said pawl into engagement with said toothed member, a main control member and a bell crank both positioned for selective engagement with said pawl to effect selective disengagement of said pawl from said toothed member, means for actuating said main control member to disengage said pawl from said toothed member after the completion of all machine operations, linkage means between said bell crank and a division operation starting key in said machine for conditioning said bell crank toward engagement with said pawl upon actuation of said key, means responsive to subsequent rotation of said motor shaft to said predetermined position for moving said conditioned bell crank into engagement with said pawl thereby to disengage said pawl from said toothed member, said retaining means including means operative to hold said pawl in its disengaged position for the entire carriage stepping time required for the tabulation of a divisor, said resetting means including means operative to reengage said pawl with said toothed member upon the completion of said carriage tabulating motion thereby to restore the operation of said machine only after completion of the tabulating stroke of said carriage.

3. The combination of claim 2 wherein said resetting means includes a movable element, positioned to be engaged by said carriage at the end of the tabulating motion of said carriage, for moving a free end of said bell crank away from the path of travel of said pawl.

4. The combination of claim 1 including means operative during the tabulating motion of said carriage for setting stops corresponding to zeros that follow the last digit of the divisor that has been entered, thereby to ensure that, at the end of the carriage tabulating motion, all such stops are in their set positions.

Claims (4)

1. In a calculating machine having a setting carriage, a main shaft, and a motor for driving said main shaft, a clutch between the shaft of said motor and said main shaft, means for operating said clutch to its engaged condition at the start of any machine operation, said clutch normally being maintained in its engaged condition until the completion of all machine operations, and a mechanism for momentarily interrupting drive from said motor shaft to said main shaft during performance of a division operation by said machine to provide a safety time between the completion of a tabulating motion of said carriage and the subsequent start of operation of said machine, said mechanism including control means jointly responsive to commencement of said division operation by said calculating machine and to subsequent rotation of said motor shaft to a predetermined position for disengaging said clutch, means for retaining said clutch in its disengaged condition as said carriage effects a stepping motion required for the tabulation of a divisor in said division operation, and resetting means responsive to completion of said carriage stepping motion for actuating said control means to effect re-engagement of said clutch.

2. The combination of claim 1 wherein said clutch comprises a toothed member on said motor shaft and a pawl on said main shaft, resilient means normally urging said pawl into engagement with said toothed member, a main control member and a bell crank both positioned for selective engagement with said pawl to effect selective disengagement of said pawl from said toothed member, means for actuating said main control member to disengage said pawl from said toothed member after the completion of all machine operations, linkage means between said bell crank and a division operation starting key in said machine for conditioning said bell crank toward engagement with said pawl upon actuation of said key, means responsive to subsequent rotation of said motor shaft to said predetermined position for moving said conditioned bell crank into engagement with said pawl thereby to disengage said pawl from said toothed member, said retaining means including means operative to hold said pawl in its disengaged position for the entire carriage stepping time required for the tabulation of a divisor, said resetting means including means operative to re-engage said pawl with said toothed member upon the completion of said carriage tabulating motion thereby to restore the operation of said machine only after completion of the tabulating stroke of said carriage.

3. The combination of claim 2 wherein said resetting means includes a movable element, positioned to be engaged by said carriage at the end of the tabulating motion of said carriage, for moving a free end of said bell crank away from the path of travel of said pawl.

4. The combination of claim 1 including means operative during the tabulating motion of said carriage for setting stops corresponding to zeros that follow the last digit of the divisor that has been entered, therEby to ensure that, at the end of the carriage tabulating motion, all such stops are in their set positions.

Images