US2662691A - Numeral wheel actuating mechanism - Google Patents

Description

Dec. l5, 1953 c. F. WEBB 2,662,691

NUMERAL. WHEEL ACTUATING MECHANISM c) N BY U /ZMMH- E Dec. 15, 1953 c. F. WEBB 2,662,691

NUMERAL WHEEL ACTUATING MECHANISM Original Filed Nov, 22, 1948 2 Sheets-Sheet 2 JNVENTOR. CHRISTOPHER FREDERICK WEBB Patented Dec. 15, 1953 NUMERAL WHEEL ACTUATING MECHANISM Christopher Frederick Webb, London, England,

assignor to Bell Punch Company Limited,

London, England, a British company Original application November 22, 1948, Serial No. 61,348, now Patent No. 2,569,508, dated October 2, 1951. Divided and this application February 25, 1950, Serial No. 146,187

Claims priority, application Great Britain December 2, 1947 3 Claims. (Cl. 23E-82) This invention relates to calculating machines and has particular reference to the type of calculating machine in which the driving rack is normally out of engagement with the registering wheels, for example the type of machine disclosed in my United States Patents No. 2,291,853, dated August 4, 1942, and No. 2,356,714, dated August 22, 1944, and in my British Patent No. 522,721, accepted June 25, 1940,

In my British Patent No. 522,721, referred to above, there is disclosed a calculating machine in which the rack is movable by a key of a bank of keys upwardly and during its upward stroke is maintained out of engagement with the pinion o f the numeral wheel. When, however, the pinion has reached the position which corresponds to the full actuation of the operated key a trip bar is moved by the action of the said key to permit the rack, under the iniiuence of a yielding control, to move into engagement with 'the pinion of the numeral wheel. In that arrangement the operated key directly engages `with a bar which extends longitudinally through column of the machine and which, upon the actuation of the key, swings the bar in a direction transverse to the normal direction of the rack as it moves into engagement with the pinion so as to permit a catch to move downwardly in a slot formed in a member connected to the rack so that the rack is then free to move under the said yielding control into engagement with the pinion of the numeral wheel. Thus it will be seen that the catch moves transversely to the line of movement of the rack by the locking movement of the trip bar actuated by the key and exact adjustment is required to synchronise the moment of releasing the trip bar by the key with the arrest of the mechanism, and it is an obiect of the invention to accomplish the release without this exact relation. Furthermore, the release of the catch referred to only takes place at the very bottom of the key stroke thereby introducing a rather harsh operation, and it is a further object of the invention to eliminate, or at least greatly to reduce, this harshness.

In accordance with the present invention, upon actuation of a key, a trip bar is movable in a longitudinal direction so as to release a catch, and such release is effected directly by the mechanism and only through the medium of the key stem.

The objects of the present invention relate to the attainment of the ends above indicated. These general obiects as well as objects relating to details of construction and operation will become apparent from the following description read in conjunction with the accompanying #drawingsJ in which;

Figure 1 illustrates in vertical section the devices associated with one bank of keys of a machine of the type described; and

Figure 2 is a diagram particularly illustrating the actuation of the rack controlling linkage above referred to.

As will be evident from reference to the prior patents mentioned above, the machine is oi the general type disclosed therein and there are not herein detailed those elements of the complete machine which are known to the art through the disclosure of said patents, the disclosure being conned to those devices which include the improvements embodying the present inventions.

The bank of keys 2 illustrated in Figure l have associated with them a key bar I, the movement of which is transmitted through a chain of links 3, 4, 5, 6, and 'I to a quadrant rack `8 movable to transmit motion in degree related to the operated key to drive a pinion 9 connected to a numeral Wheel III. The link 1, of the said chain of links, is connected to the quadrant rack 8 so that anv relative movement between the quadrant rack 8 and the link 'l is solely of a pivotal nature. The link 'I is operable through the remaining links of the chain to impart to the quadrant rack 8 a velocity which increases from zero. The return movement of the quadrant rack 8 to its position of rest is also eiiected gradually, thus insuring that the ouadrant rack 8 is provided, both at the commencement of its movement and at the end thereof, with a relatively slow motion which reduces the inertia of the quadrant rack and the numeral wheel 9 to a minimum and assures the smooth and gradual arrest thereof.

When a key 2 is depressed an abutment thereon engages with the kev bar I to move the same downwardly. The key bar I is connected at substantially the ends thereof to a bell crank lever II pivoted at IIa on a fixed transverse pin and to a link 4 which is shaped as a bell crank lever. The construction is such that as a key is moved downwardly the key bar moves downwardly and inwardly as described in said patents. As the kev bar I moves downwardly it imparts through the pins of links 3 to 1, inclusive, to the quadrant rack 8 a motion which will be more speciically set out in describing Figure 2. It will be observed that the link 3 is nivotallv connected to both the key bar I and the link 4 bv pivot pins I2 and I3. The link 4 is pivotallv mounted upon a xed pin I5 which ex'tends the entire breadth of the machine, and is common to the various key orders thereof. The end of the link 4, remote from that which is connected to the link 3, is pivotally connected to the link 5 which in turn is pivotally connected to a point intermediate the length of the link 6 which is shaped as a bell crank lever. The upper end of the link 6 is pivoted upon fixed spindle I6 which extends through the entire breadth of the machine. The lower end of the link 6 is pivotally connected to the link 'I which in turn is connected through a pivot pin to the quadrant rack 8 so that the only movement of the link 'I relatively to the quadrant rack 8 is a pivotal movement, thereby avoiding any sliding movement of the pivot in a cam groove as disclosed in Patent No. 2,356,714.

Referring specically to Figure 2, there 1s diagrammatically illustrated the operation of the chain of links as the key 2a carrying the numeral 9 is depressed to move the quadrant rack 3 from its position of rest through its complete movement of nine teeth. An arm 4a of the link 4 is shown pivotally connected at A1 to a selector bar I'I. As the key 2a of the series of keys 2 is operated it moves, through `the medium of the bell crank levers II and 4, with selector bar VI through the positions marked A, B, C, D and E. As the selector bar is moved through these positions the pivot pin of the arm lla moves through the positions A1, B1, C1, D1 and E1 and the free end of the link 4, shown as pivotally connected at Az to the link 5, moves through the positions A2, Bz, C2, D2 and E2, while the end of the link 5 which is shown as pivotally connected at A3 to the link 6 moves through the positions A3, B3, Cs, D3 and E3. The movable end of the link 6 is pivotally connected at A4 to the link 7 and moves through the positions A4, B4, C4, D4 and E4 while the link 1 which is pivotally connected at A5 to the quadrant rack 6 does not Vmove at all during the initial movement of the other links from their A to their B positions, after which the end of the link I which is pivotally connected to the quadrant rack 8 takes up the successive positions C5, D and E5. The initial positions A5 and B5 are coincident. -As the link 'I moves so that the quadrant rack 8 is moved the successive positions of the first tooth are those indicated at As, B6, Cs, De and Es, Ae and Be being coincident.

It will be observed that during the operation of the machine the upward movement of the rack may be arrested by the appropriate key at any tooth position from one to nine, this being controlled by the co-operation of key stems with the bars I and I'I, as disclosed in said prior patents. At any of such positions the connection of the link I with the link 9 becomes temporarily a stationary point about which the link 'I can swing to permit the quadrant rack 8, when released, to move into mesh with its pinion 9. It should further be noted that at any one of the said nine positions the link 1 will insure that the tooth engagement of the quadrant rack 8 with the pinion 9 is in a substantially radial direction relatively to the pinion 9. i

It will be observed from the above that upon the initial movement of the key the operator merely sets the chain of links which is to operate the quadrant rack 8 into motion, without effecting any movement of the rack 8 itself, after which the quadrant rack 8 is moved to an accelerated degree. Referring to Figure 1 it will be observed that the main spring I8 is anchored to a lateral extension 4b of the link 4, the arrangement being such that shortly after the movement of the link has commenced the anchorage point of the extension 4b of the link rises so as to cause the effective leverage of the tension spring I8 about the pivot A1 to diminish as the tension of the spring I8 increases. The arrangement of the link 4 and extension 4b thereof is designed to produce a substantially constant resistance to the pressure of the operators finger throughout an operating stroke. If the connection between the link I and the quadrant rack is of a purely pivotal character, friction is minimised as contrasted with that involved in a sliding pin and slot.

Upon the completion of a key stroke the quadrant rack 8 is released by the trip mechanism as hereinafter described and is moved under the iniiuence of the driving spring I 8 into engagement with the pinion 9, this being effected through the pivotal connection of the rack to the lever i9 to which the rear end of the spring is secured. As the quadrant rack returns to its position of rest under the influence of the spring I8 and therefore returns the pinion 9 and the numeral wheel I0 to their positions of rest it arrives at such a position of rest before the chain of links forming the operative connection between the quadrant rack andthe key bar have ceased moving. Consequently, it is insured that the numeral wheel it 2l and locking lever 22.

and its pinion 9 are stationary before the mechanism effecting the withdrawal of the rack from the pinion 9 is brought into operation.

Associated with each pinion 9 there is a pawl This arrangement normally locks the pinion 9 against rotation, and an arrangement is provided which, when a pinion 9 of a bank of keys is about to be set in motion as the result of actuation of a key, automatically releases the pinion. The pinions 9 are released either when the rack 8 positively moves the pinion or when a transfer mechanism 23 rotates through the medium of pins 23a a toothed wheel 24 connected to the pinion 9. mechanism is disclosed in Patent No. 2,291,853, and need not be described in detail except to the extent of reference to the pins 23a.

First, dealing with the instance where the pinion 9 is moved by the rack B it will be evident that when the trip mechanism described hereafter releases the rack S the lever 22 is moved in a counterclockwise direction about its pivot 2? by the iiexing of a spring 23 connected between it and the lever I9. By this action the lever 22 is moved downwardly and out of engagement with the locking surface 29 with which it normally engages. The pawl 2l released from its positive locking engagement with the pinion 9 permits the numeral wheel to be freeiy rotated. Due to the fact that the pawl 2I is not of a yieldingly controlled type which snaps into and out of engagement with the tooth of the pinion 9 the operation of the numeral wheel is rendered less noisy than in the case of a pinion wheel which is restrained by a yieldingly controlled pawl.

When a numeral wheel of a lower order is transferring to a numeral wheel of a higher order the pins 23a are arranged to engage with the right hand lateral extension 22a of the locking lever 22 to swing the same in a clockwise direction about its pivot 21 so as to move the locking lever out of engagement with the locking surface of the pawl 2 I. After the transfer action has taken place the pawl again becomes locked in the position indicated, this being insured by contact of pin 23a with the left hand extension 22a of the locking lever.

It has been shown that the numeral pinions are always positively locked except when an adding or transferring operation is in progress, but it will be appreciated that it is also necessary This transfer to remove any obstruction from the path of the pinions during a cancelling opeiation in order to permit the numeral wheels to be returned to zero. For this purpose there may be provided means for displacing by manual operation of a cancel lever all of the pawls 2| lin the axial direction of the pinions 9 so that the pawls 2| are temporarily moved out of the path of the pinions 9 Without in any way interfering with the locking functions already described. A spring 21a is arranged to exert a slight torque on the pawl 2l in axial direction to return the tip of the pawl into the plane of the pinion following a cancelling operation.

It will be seen that according to the present invention there is provided a calculating machine in which the pinions of the numeral wheels are normally locked positively against rotation, and wherein the arrangement is such that when the pinion wheels are about to be set in motion the positive lock is released and the pinion wheels are free to be rotated eliminating all friction and enabling a lighter key touch to be employed in view of the fact that the driving spring I8 need not be as strong as would be the case if a yieldingly controlled pawl was employed. A

After the rack 8 has moved free of the pinion to the degree determined by the key which has been operated, it must be permitted to engage the pinion and this action is effected upon full depression of the key. The lower end of a key stem, when it reaches the position indicated in dotted lines at 2b, is adjacent one of the projecting lugs 32 formed on a trip bar 33. When the key stem reaches the dotted position a tooth of the bar l1 will have reached the face of the key at 2b and at the same time, a groove 2c formed in the opposite face of the key will be coincident with the lower guide through which the key passes. When the moving bar l1 touches the key the latter is therefore displaced horizontally a small amount, whereby the lug 32 and the trip bar 33 are moved from right to left as viewed in Figure 1. This movement of the trip bar 33 swings catch lever 34 pivotally mounted at 35 about this mount so as to move the end 36 thereof out of engagement With a tongue 31 carried by the lever I9 which at pivot point 3l is connected to the rack 8. When the catch lever 34 is released from the tongue 31 the spring i8 urges the rack in a direction toward the pinion 9 of the numeral wheel I0.

It will be noted that the lever I9 is released by the roller 26 on the bar l1 when a key is depressed, and that this same roller effects disengagement of the rack 8 from the pinion 9 by its action on the lever I9 when a key is released to its uppermost position.

Thus it will be seen that the movement of the bar I7 of the mechanism, in response to the depression of a key, causes the release of catch 36 without direct vertical contact of the end of the key stem as formerly required, and in ordinary operation the trip is effected by the momentum of the mechanism without direct influence from the key. Such an arrangement practically eliminates that harshness introduced by the dead end stroke operation inherent in the arrangement described in said British Patent No. 522,721.

This is a division of my application Serial No. 61,348, led November 22, 1948, now Patent No. 2,569,508, and contains subject-matter in common with the copending Webb application, Serial No. 146,186, led February 25, 1950.

What is claimed is:

l. In a calculating machine having a plurality of keys each having a key stem, a numeral wheel, a pinion connected to said numeral wheel, and differential actuating means movable by said keys to produce variable movements of said numei'al wheel, said means comprising a member movable longitudinally in response to depression of a key and being arrested by abutment against one side of a depressed key stem, a rack, a catch normally holding said rack out of mesh with said pinion, a spring urging said rack towards said pinion, and a trip bar having surfaces contiguous to the opposite sides of said key stems mounted for movement in a longitudinal direction, said trip bar being moved longitudinally by a key stern actuated by said longitudinally movable member upon effective actuation of a key to ren lease said catch.

2. In a calculating machine having a plurality of keys each having a key stem, a numeral wheel, a pinion connected to said numeral wheel, and differential actuating means movable by said keys to produce variable movements of said numeral wheel, said means comprising a member movable longitudinally in response to depression of a key and being arrested by abutment against one side of a depressed key stem, a rack, a pivotally mounted catch normally holding said rack out of mesh with said pinion, a spring urging said rack towards said pinion, and a trip bar having surfaces contiguous to the opposite sides of said key stems mounted for movement in a longitudinal direction and operatively connected to said catch, said trip bar being moved longitudinally by a key stem actuated by said longitudinally movable member upon effective actuation of a key to release said catch automatically by eiecting pivotal movement thereof.

3. In a calculating machine having a plurality of keys each having a key stem, a numeral wheel, a pinion connected to said numeral wheel, and differential actuating means operable by said keys to cause variable movements of said numeral wheel, said means comprising a rack, a

spring urging said rack towards said pinion, a catch comprising a longitudinally extending member pivoted on a transversely extending axis and normally holding said rack out of mesh with said pinion, means for positioning said rack in response to effective depression of a key and for moving the stem of the depressed key laterally of its longitudinal axis upon the completion of the rack positioning, a trip bar mounted for movement in a longitudinal direction in response to movement of said key stem by said positioning means and operatively connected to said catch to release said catch upon movement of said key stem by said positioning means by effecting pivotal movement of said longitudinally extending member.

CHRISTOPHER FREDERICK WEBB.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 926,151 Vincent June 29, 1909 1,538,447 Petter May 19, 1925 1,700,057 Johnson Jan. 22, 1929 1,983,945 Petter Dec. 11, 1934 2,356,714 Webb Aug. 22, 1944

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