Title:
FUNCTION KEY MECHANISM IN CALCULATING MACHINE OR THE LIKE
United States Patent 3612831


Abstract:
A function key mechanism in a calculating machine or the like, wherein the selection of a lever, a shaft, etc. is effected by the drive of a motor, whereby the force required for operating a function key is remarkably reduced.



Inventors:
MIYAKE KENJI
Application Number:
04/889098
Publication Date:
10/12/1971
Filing Date:
12/30/1969
Assignee:
CITIZEN WATCH CO. LTD.
Primary Class:
Other Classes:
235/62B
International Classes:
G06C21/04; (IPC1-7): G06C23/00
Field of Search:
235/62,60
View Patent Images:
US Patent References:
3335947N/A1967-08-15Edwards et al.
3315889Control key arrangement for a calculator1967-04-25Thevis
3252653N/A1966-05-24Brinning
3092315N/A1963-06-04Toorell
2745601N/A1956-05-15Fowler et al.
1909714Automatic calculator1933-05-16Pasinski



Primary Examiner:
Tomsky, Stephen J.
Claims:
What is claimed is

1. A function key mechanism in a mechanical calculating machine comprising in combination,

2. The combination of claim 1 which further includes a pivotally supported swing lever (16) which is pivotally actuated by actuation of said function key (1),

Description:
The present invention relates to a selection lever driving mechanism in a calculating machine or the like, which is operatively associated with a function key.

A conventional selection lever driving mechanism to be operated by a function key is so constructed that in case of an adding operation, for example, selection members for selectively engaging cams or adding and subtraction gears, necessary for the operation, memory and typing, are operated by an adding key concurrently with a motor-driving switch lever. In such operation, since the selection of the levers necessary for operation, memory and typing involves pivotal movement and sliding of a large number of levers and shafts, the function key becomes heavy as compared with the numeral setting keys and 1 kg. or even larger force is required for operating the function key.

The object of the present invention is to reduce the force required for operating a function key of a calculating machine or the like, so that the function key can be operated lightly with a soft key touch.

The mechanism according to the present invention is characterized by the fact that the selection members which have selected the levers, shafts and cams, necessary for operation, memory and typing, by the drive of a motor, are operated upon actuation of the function key.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings, showing by way of example a preferred embodiment of the invention. In the drawings,

FIG. 1 is a side view diagrammatically showing an embodiment of present invention;

FIG. 2 is a plan view taken along the line A--A of FIG. 1;

FIG. 3 is a side view taken along the line B--B of FIG. 1;

FIG. 4 is a cross-sectional view taken on the line C--C of FIG. 1;

FIG. 5 is a cross-sectional view taken on the line D--D of FIG. 1;

FIG. 6 is a view taken along the line E--E of FIG. 1;

FIG. 7 is a cross-sectional view taken on the line F--F of FIG. 1;

FIG. 8 is a cross-sectional view taken on the line G--G of FIG. 2;

FIG. 9 is an operational view of FIG. 8;

FIG. 10 is an operational view of the mechanism operated by a key stem; and

FIG. 11 is an operational view of the mechanism operated by a clutch.

Referring to FIG. 1, numeral 1 designates a function key having its stem 2 slidably supported by an upper panel 3 and a lower panel 4 of a key board. The function key is biased upwardly by a spring 5. Numeral 6 designates a locking bar which is formed with projections 6a at the opposite ends of the upper edge thereof and with a projection 6b at about the center of the lower edge thereof, said projections 6a being slidably received in guide slots formed in the upper panel 3, respectively, and said projection 6b being slidably received in a guide slot formed in the lower panel 4 of the keyboard. The locking bar is also formed with projections 6c at the opposite ends of the lower edge thereof, which are in sliding engagement with the lower panel 4 of the key board and by which the position of the locking bar is determined. Further, the locking bar 6 is provided with oblique slits 6d for engagement with a pin 7 fixed to the key stem 2. Numeral 8 designates a control lever operatively associated with each key stem 2 and mounted on a shaft 9, fixed to a machine frame, for free-sliding and pivotal movements. A spring 10 has one end anchored the control lever 8 and the other end to the machine frame, so as to maintain the control lever 8 in the position shown in FIGS. 3 and 4.

The control lever 8 is provided with a cam 8a at the top portion thereof, which will engage the lower edge 2a of the key stem 2 to cause the lever to slide to the right or left as viewed in FIG. 3. Numeral 11 designates a selection lever which will selectively engage the respective control levers 8 to select the cams and levers of the known type necessary for operation, memory and typing. Numeral 12 (FIG. 1) designates a pivotable lever pivotably mounted on a shaft 13 fixed to the machine frame. One end of the lever 12 is pivotally connected to the locking lever 6 by a pin 14 and the other end thereof to a connecting lever 15. Numeral 16 designates a swing lever which is pivotably mounted on a shaft 17 fixed to the machine frame and yieldably connected to the connecting lever 15 by a spring 18. A vertically extending end 16a of the swing lever 16 is received in a slot 15a formed in the connecting lever 15 (see FIG. 6) and a horizontally extending end 16b thereof is in engagement with a clutch pawl 19. A projection 16c of the swing lever 16 is received in a slit 15b formed in an upright portion of the connecting lever 15 (see FIG. 7).

Numeral 20 designates a follower lever which is pivotably mounted on a shaft 21 fixed to the machine frame, and the clutch pawl 19 is pivotably mounted on a pin 22 fixed to the follower lever 20. A positioning lever 24 is pivotably mounted on a pin 23 fixed to the follower lever 20 and a V-shaped end 24a of said positioning lever 24 is received in a recess 19a formed in the clutch pawl 19 in pressure contact therewith under the biasing force of a spring 25.

Numeral 26 designates a clutch gear which is mounted on a motor shaft 27 for engagement with a projection 19b of the clutch pawl 19. Numeral 28 designates a connecting rod with one end pivotally connected to the follower lever 20 and the other end pivotally connected to a pivotable lever 29 pivotally mounted on the shaft 13. Numeral 30 designates a driving plate slidably supported by the machine frame. The driving plate 30 is in pivotal engagement with the pivotable lever 29 at one end thereof and the control lever 8 will be brought into engagement with the driving plate 30 as indicated by the chain lines in FIGS. 3 and 5, when displaced by the key stem 2. Numeral 31 designates a connecting rod having one end pivotally connected to the pivotable lever 29 and the other end pivotally connected to a clutch holding lever 33 which is pivotally mounted on a shaft 32 fixed to the machine frame.

In FIGS. 8 and 9, numeral 34 designates a calculating machine driving clutch pawl pivotally mounted on a pin 36 which is fixed to a clutch plate 35 mounted on a cam shaft 40. Numeral 37 designates a clutch gear fixedly mounted on the motor shaft 27. A spring 38 has one end anchored to the clutch pawl 34 and the other end to the clutch plate 35, to engage the clutch pawl 34 with the clutch gear 37.

The mechanism constructed as described above operates in the following manner. When an optional function key, e.g., an adding, subtotal key 1a, is depressed, the pin 7 of said function key is brought into engagement with the oblique slit 6d of the locking bar 6, causing said rocking bar to slide in the direction of the arrow a. The pivotable lever 12 connected to the rocking bar 6 is pivoted in a counterclockwise direction and hence the swing lever 16 is pivoted in a clockwise direction by the connecting lever 15. The clutch pawl 19 is caused to rotate in the counterclockwise direction, as shown in FIG. 10, by the end 16b of the swing lever 16. The clutch pawl 19, the pin 22 and the clutch gear 26 are arranged in such a positional relation that the engagement between the clutch pawl 19 and the clutch gear 26 will become deeper and deeper, once they have been brought into engagement with each other. THe clutch gear 26 is constantly rotated by a motor (not shown) in a clockwise direction as indicated by the arrow b. Therefore, when the clutch pawl 19 is engaged by the clutch gear 26, said clutch pawl 19 and the follower lever 20 are integrally rotated in a counterclockwise direction about the shaft 21. The rotation of the follower lever 20 is transmitted to the clutch-holding lever 33 through the connecting rod 28, the pivotable lever 29 and the connecting rod 31 to pivot it in a counterclockwise direction as shown in FIG. 11, so that the pin 39 fixed to the clutch-holding lever 33 is released from engagement with the clutch pawl 34 (see FIGS. 3 and 9) and the clutch pawl 34 is brought into engagement with the clutch gear 37 on the motor shaft 27 under the biasing force of the spring 38 to rotate the cam shaft 40 (see FIG. 2). On the other hand, when the key stem 2 is moved down, the cam 8a of the control lever 8 engages the lower surface 2a of the key stem 2, with the result that the control lever 8 slides toward a position indicated by the phantom lines in FIGS. 3 and 5, in which it is held in engagement with the driving plate 30. Therefore, when the driving plate 30 is caused to slide to the right by the lever 29, the control lever 8 is pivoted in a counterclockwise direction and the selection lever 11 associated therewith selects a cam, a shaft and a lever (not shown) necessary for operation, memory and recording.

The cam, the shaft and the lever, which have been selected by the series of operation described above, must be retained until the calculation cycle will have been completed. For this purpose, the pin 39 fixed on the clutch holding lever 33 is withheld by the outer periphery of the clutch plate 35. Thus, the cam, the lever and the shaft selected will not be allowed to make an unnecessary movement in the course of the calculation cycle. When the calculation cycle is about to be ended, the pin 39 of the clutch holding lever 33 is received in the recess 35a of the clutch plate 35 and engages the clutch pawl 34. As a result, the clutch pawl 34 is released from engagement with the clutch gear 37 and the cam shaft 40 stops rotating. The above-described clutch mechanism is of the known type used in the conventional adding machines. As the pin 39 of the clutch holding lever 33 is received in the recess 35a of the clutch 35 at the terminal end of the calculation cycle, the control lever 8 is also returned to its original position which has previously been brought into engagement with the driving plate upon operating the function key stem 2.

The mechanism is so designed that the calculation cycle is always accomplished by a single step of operation. Namely, when the swing lever 16 is pivoted clockwise by the connecting lever 15, the projection 16a of the swing lever 16 moves the connecting lever 15 downward. Therefore, the engagement between the slit 15a of the connecting lever 15 and the projecting end 16a of the swing lever 16 is released as the pivotal movement of said swing lever 16 proceeds and the swing lever 16 only is returned to the original position under the biasing force of the spring 41. The engagement between the clutch pawl 19 and the clutch gear 26 is previously adjusted so as to cause a necessary stroke of the selection lever 11 and a necessary pivotal movement of the clutch holding lever 33. The clutch pawl 19 is returned to its original position (at the same time when the engagement thereof with the clutch gear 25 has been completed) and locked in a position shown in FIG. 1 by the spring 25. THerefore, the clutch pawl 19 will not engage the clutch gear 26 in the return step of the mechanism.

As will be apparent from the foregoing description according to the present invention the key can be operated very lightly since the selection of the lever and the shaft can be effected by the drive of a motor.