US1955606A - Combined typewriting and computing - Google Patents

Description

' April 17, 1934. H PI MAN 1,955,606

COMBINED TYPEWRITING AND COMPUTING MACHINE Filed Feb. 23, 1932 EIGJ.

INVENTOR: 45 W M ATTORN- Patented Apr. 17, 1934 UNITED STATES PATENT OFFICE COMBINED TYPEWRITING AND COMPUTING MACHINE Application February 23, 1932, Serial No. 594,49

9 Claims.

cient functioning of such devices in a typewriter in which computing registers may be used and caused to be operated by strokes of numeral-keys. For correct operation of such registers, it is necessary not only that the key-stroke be completed in both directions, but that Where a full-stroke device is used, it is very desirable that there be very little backlash in the register-operating portion of either the down or the up stroke.

One of the aims of the invention is to provide a set of full-stroke racks which can be mounted as a unit in the combined typewriting and adding machine, and also to provide readily accessible and easily controllable means for setting said unit at difierent elevations or positions, so as to compensate for slight differences in manufacture in diiferent kinds of machines in this class.

According to the present invention, a full-stroke rack of simple form is employed in which teeth finely spaced to minimize the backlash may read- ,ily be out, said teeth co-operating with a doublearmed pawl pivoted to the key-lever to check untimely reversal of either the up or down keylever stroke. It is also desirable that for convenience of assembling and maintenance, the

racks be mounted stationary relatively to the keystrokes, such mounting of the racks being accomplished in the present invention by simple and inexpensive devices which also permit fine adjustment of the racks in the direction of keylever strokes, the racks being simple punched blanks, and being formed for easy attachment to said mounting, and for easy removal to facilitate inspection or replacement. It will be apparent, however, that material benefits may be derived from other features of the invention irrespective of whether it is the rack that is stationary with respect to the key-stroke or whether it is the pawl that is stationary.

For positively checking untimely reversal of the key-lever stroke, it is desirable that the rackteeth be of suitable form to engage and hold the pawl positively during such checking. Tothis end, a saw-tooth form is preferably used, and two series of teeth are cut in the rack, one arm of the key-lever pawl being engageable with one series, and the other arm of said pawl being engageable with the other series, the pawl-arms extending to opposite sides of the pawl-pivot, and substantially in the direction of the keystrokes. As viewed in profile, the saw-shaped teeth in one series are reversed with respect to the saw-shaped teeth in the other series, so that the saw-tooth form of each series may be effective with the pawl-arm with which it co-operates. A further feature of the improved full-stroke rack is a single two-way pawl-shifting cam formed on said rack between the two series of pawl-teeth, said cam being effective to engage either one of the pawl-arms. The two series of rack-teeth and the intermediate cam form a profile which in itself is complete to coact with the pawl-arms and to effect the shifting of the pawl, and which profile, including finely spaced teeth, may be cheaply, yet accurately, machined by a form-milling cutter, broaching device or other suitable tool. Blanks from which the racks are made are simple punchpress stampings.

Each key-lever Whose strokes it is desired to control is provided with one of the novel fullstroke racks, and one of the two-armed pawls is pivotally mounted on the side of the key-lever, so that the rack mounted adjacent to the keylever and extending in the direction of key-stroke may coact with said pawl. A suitable detentdevice for the pawl is also carried by the keylever and co-operates with the rack-cam to shift the pawl at the extremities of the key-strokes, said detent-device being also effective to hold the pawl in either of the positions into which it may be shifted to co-operate with one or the other series of rack teeth.

A difficulty that arises in machines in which the master-wheel of the adding mechanism is rotated by the key, and wherein the master-wheel comes to rest before the key has driven the typebar to the platen, and wherein the full-stroke rack ceases to function as soon as the masterwheel is completed, and wherein the key proceeds to descend further in order to complete the movement of the type-bar to the platen, and also in order to complete the initial movement of the carriage-feeding mechanism, is that there is considerable movement of the key possible at the lower portion of the stroke after the masterwheel has turned and after the full-stroke rack has ceased to function. Machines of this class are subject to a rebounding action of the type from the platen, and this rebound can occur in the above-described play of the key below the range of action of the full-stroke device. Due to such rebound and such play, the mechanism of the carriage is apt to be operated again, thereby causing a serious error in the calculation.

The present improvements aim to render the full-stroke rack effective for practically the entire descent of the key, so that the rebound of the type-bar and key cannot occur, or is at least so diminished that the carriage-escapement mechanism cannot make a false additional operation. In order to secure this full control by the fullstroke rack, the latter is rendered micrometrically adjustable, so that it can be rendered effective to the utmost possible extent, and so that thereafter there should be only enough left of the final portion of the key-stroke to enable it to reverse the action of the full-stroke pawl. This close adjustment of the full-stroke rack is effected by a micrometer adjustment which may be common to all the racks.

Novel means for supporting the full-stroke rack are devised to reduce manufacturing costs, and are thus of advantage where a full bank of numeral-keys and a corresponding number of racks are employed. To this end, there is provided a punched plate which may span the lower portion of the typewriter-frame to underlie the numeralkey-levers, said plate being provided with punched apertures into which the lower ends of the aforesaid racks may be inserted, said lower ends in the illustrated form herein shown being provided with a shoulder to abut the top of said plate, and also being provided with a hole through which, when the rack is inserted, there may be threaded a removable pin to abut the lower side of the plate, said shoulder and pin thus co-operating to keep the rack in place.

The rack-carrying plate with the upstanding racks therein is attached to the typewriter-frame in a manner to permit fine up-and-down adjustment of said plate and hence of the racks, said adjustment being efiective to set the racks relatively to the key-lever strokes; it being understood that the pawls which coact with the racks are pivoted on the key-levers.

Means preferably in the form of a grooved roll or stud are carried by each key-lever to guide the associated rack at its upper ends against displacement relatively to the pawl. Sufficient looseness in the connection of the lower end of the rack to the supporting plate may be provided for, the upper portion of the upstanding rack being thus able to float about a longitudinal axis of the rack. Hence, even though the guiding means are used to prevent relative displacement of the pawl and rack, binding between the keylever and rack during the key-lever strokes is avoided. This feature is conducive to economy in manufacture, inasmuch as the necessity for close tolerances in machining and assembling the parts is avoided.

Other features and advantages will hereinafter appear.

In the accompanying drawing,

Figure 1 is a view of a cross-section of the typewriting machine showing, in side elevation, the type-action, the computing register and the arrangement of the novel full-stroke device. Said view may be considered as representing a row of numeral-key levers.

Figure 2 is a partial perspective, looking at the front of the typewriter from the left side, and

brings out details of the full-stroke device, not apparent in Figure 1.

Figure 3 is a side elevation similar to the lower right portion of Figure l and illustrates the fullstroke device with the key-lever depressed.

;swing and print against a platen 17. Spri gs 11 return the parts to normal position in which the type-bars 16 rest on pad 12. Said key-levers 11 are spaced and guided near their forward ends by the usual slotted plate 35 attached to the typewriter-frame 13.

The usual letter-feeding carriage for said platen 17 is represented by an extension 18, to which is attached a computing register 19, which, in the carriage-travel, overrides a stationary actuator 20, connected to said numeral-key-levers by links 21, said register, actuator and key-levers co-operating in a well-known manner, to the end that whenever a numeral-key is operated in a column of a computing zone of the carriagetravel, a corresponding register-wheel 22 is rotated'to an extent corresponding to the value of the numeral-key. In order that said registerwheel 22 may register accurately, it is necessary that the numeral-key be operated to the full extent of its down and reverse strokes, proper operation of the usual value-translating devices (not shown), associated with the actuator 20, depending on the completion of said strokes, and also depending on the prevention of any untimely reverse movement of the key-lever during the operative portions of said strokes.

The novel mechanism whereby full-stroke. movements and the prevention of untimely reversals of such movements are assured, will now be described.

For co-operation with a full-stroke pawl 23, pivoted and retained on a numeral-keylever 11, by a headed pivot-stud 24, there is provided a full-stroke rack 25, there being a plurality of pawls and racks, so that there is one pawl and one rack for each numeral-key-lever. Said racks are held stationary relatively to the up-and-down key-lever strokes by means to be described in detail later on. Each rack 25 has a longitudinal' edge extending in the direction of key-lever strokes, on which edge are formed two series of teeth 26, 27. The upper series of teeth 26 may. engage an upper arm 28 of the pawl 23 to check,

ward movement of said key-lever when the key lever stroke is upward, the pawl 23 being shiftable about its pivot-stud 24, so that either of arms 28, 29 may engage the corresponding series of teeth, it being understood that while one arm is engaged with its series of teeth, the other arm is not so engaged. The shifting of the pawl oc curs at the ends of the key-lever strokes, and is effected by means of a single two-way V-cam 30, formed between and separating the two series of teeth 26, 27. The peak of said cam 30 projects suificiently beyond the tops of the rack-teeth to secure an adequate extent of shifting movement of the pawl.

pivot-stud 32. Said detent-lever' 31 has a V- shaped nose 33, the sides of which may override and engage the sides of a corresponding V-shaped arm 34 of the pawl 23.

The nose 33 of the detent-lever 31 is caused to be spring-pressed against the V shaped pawl-arm 34 of the pawl by means of a spring 36, which may be anchored at one end to a stud 37 of the keylever, the other end of said spring 36 being attached to and pulling on an arm 38 of the detentlever 31. Figure 1 shows in full lines the keylever and its attached pawl and detent-lever in normal position, in which, as shown by such full A detent-lever 31 for the pawl is pivoted and retained on the key-lever by a headed,

tached pawl and detent-lever, in which position the lower arm 29 of the pawl is seen to be engaged with the lower series of rack-teeth 27. It will be seen in the normal or full-line position, Figure 1, of said key-lever that the upper side of the detent-lever V-shaped nose 33 presses against the lower side of the V-shaped pawl-arm 34, thereby causing, through the tension of the spring 36, the upper arm 28 of the pawl to be pressed against the upper series of rack-teeth 26. In a similar manner, it may be seen, in the broken line or depressed position of said key-lever 11, Figure 1, that the lower arm 29 is caused to press against the lower series of teeth 2'7, the lower edge of the V-shaped nose 33 in this instance pressing against the upper edge of the V-shaped pawlarm 34. Thus, during the downward key-movement, the tip of the upper pawl-arm 28 clicks or trails idly over the upper series of teeth 26, the lower pawl-arm 29 during said downward keymovement being totally disengaged from its series of teeth 27. It will similarly be seen that during an upward movement of a key-lever 11, the tip of the lower pawl-arm 29 will click or trail idly over the lower series of teeth 27, the upper arm 28 being in this instance totally disengaged from its corresponding series of teeth 26. To ensure that the tips of the pawl- arms 28, 29 may not escape from their respective rack- teeth 26, 27, when an untimely reverse movement of the key-lever stroke is to be prevented, said teeth are preferably made of saw-tooth form. As viewed in profile, it will be seen that the form of one series of teeth 26 is reverse with respect to the other series of teeth 27. In each series of teeth, therefore, the tip of the corresponding pawl-arm may be engaged by a tooth-edge that is so inclined relatively to the pawl-pivot that when the pawl-arm and tooth-series are in contact, said pawl-arm, in any attempt at untimely reversal of the key-stroke, is forced toward the rack-teeth and cannot escape therefrom, and said untimely reversal is positively prevented. It will also be seen that the teeth in each series may be cut with any requisite degree of spacing best suited to insure proper operation of the register 19 and its actuator 20.

Figure 3 shows how the cam 30, forming part of rack 25, efiects shifting of the pawl 23, said Figure 3 illustrating the instance in which the key-lever 11 is just about to complete its downward stroke. It will be seen from said Figure 3 that just before the key-lever completes said downward stroke, the peak of the V-shaped pawlarm 34 is just overriding the point of the V- shaped detent-lever nose 33, the pawl 23 having been caused to rotate counterclockwise as the upper pawl-arm is engaged and displaced by the rack-cam toward the end of the downward key-lever stroke. Completion of said downward key-lever stroke to the position indicated by the broken outline 40 of the key (Figure 3) will cause a further displacement of the upper pawl-arm 28 of the rack-cam 30, and hence further counterclockwise rotation of the pawl 23 about its pivot. This rotation of the pawl is extended by the pull of the spring 36 as the point of the V-shaped pawl-arm 34 passes the point of the V-shaped detent lever nose 33, so that, as shown by the broken-line position in Figure 1, the upper pawlarm 28 is caused to be fully separated from the teeth of the rack-cam 30 when the key-stroke is completed, the lower pawl-arm 29 being then in engagement with the lower series of teeth 2'7. In a similar manner, near the end ,of the upper key stroke, the lower arm 29 of the pawl is engaged and displaced by the rack-cam 30 with a consequent clockwise rotation or shifting of the pawl 23, so that it finally assumes the position shown by the full lines in Figure l, and in which position it will be seen that the lower arm 29 s ful y parated from the lower series of teeth 27 and that the upper pawl-arm 28 is then in engagement with the upper series of teeth 26.

For holding the racks 25 stationary relatively to the direction of key-lever strokes, there is provided a simple elongate plate 41 extending lengthwise from one side of the typewriter-frame to the other and underlying the key-levers. Said plate may be stiffened by turning up its edge, as seen at 42. The plate is provided with rectangular punched apertures 43, spaced like the key-levers 11, into which apertures the lower ends of the racks may be inserted, each rack being provided with a shoulder 44 to abut the top surface of the plate 41, and being further provided with a hole through which there may be threaded a removable cotter-pin 45, said shoulder and pin keeping the rack in place in the plate 41.

For free action of the key-levers, the sides of the upper portions of the racks are spaced slightly from the sides of the key-levers, and, to this end, each key-lever has projecting therefrom a grooved stud or roll 46, which, as seen in Figure 2, spaces the side of the upper rack-portion from the key-lever.

It will be apparent that any one of the racks 25 may be removed easily from the machine when its cotter-pin 45 is removed. To withdraw a rack, the best procedure is to raise the rack until its lower end clears the top of the plate 41 and then to bring said end forwardly to clear the plate 41 sufficiently to eifect downward withdrawal of the rack. The groove in said stud or roll 46 embraces a front edge 47 of the rack, said front edge 4'? bearing against the bottom of the groove, and thus preventing excessive forward and rearward displacement of the rack 25. A slight forward and rearward displacement of said rack is permissible, yet may be avoided by curving the rack-edge 47 to conform to the slightly arced path in which the grooved roll 46 moves. The arcing of this path is so slight, however, that in the illustrated form of the invention, said rackedge 4'7 is shown as being straight. The connece tion of the lower ends of the racks with the plate 41 may be of sufiicient looseness to permit the upper end of each rack to float about the vertical axis of said rack. Sufficient floating movement may thus be obtained, without any undue up-and-down play of the racks, and is conducive to free action of the key-levers during their proper operating strokes. This floating movement is also conducive to braking the key-lever against an untimely reversal of the key-stroke because, as already explained, when such an untimely reversal is attempted the active pawl- arm 28 or 29 is forced against the rack 25 which in turn is forced against the bottom of the groove in the roll or stud 46 to thereby afford a corresponding measure of braking effect upon the key-lever.

The initial and final positions of the keylevers are liable to variation, due to assembling adjustments of the type-action, and to accommodate such variation the plate 41 is provided with an up-and-down adjustment, so that the upstanding of said lug 48.

racks 25 in said plate may also be adjusted up and down. As already explained, the plate extends from side to side of the typewriter-frame, which, for attachment of said plate, may be provided with lugs 48. The ends oi the plates may be provided with downwardly-extending screwstems 50 having flanges 51 affording a broad bearing of said screw-stems 50 against the plate 41, in which the upper portions of said screwstems may be riveted, as indicated in Figure 2. The screw-stems 50 pass through clearance holes in the typewriter-frame lugs 48, and each stem has threaded thereon adjusting nuts 53, 54, the nut 53 being for abutment against the upper surface of the typewriter-frame ing 48, and the nut 54 being for abutment against the bottom surface It will be seen now that manipulation of the nuts 53, 54 may effect raising or lowering of the plate 41, and consequently raising or lowering of the racks 25 for adjustment of said racks relatively to the key-strokes. By means of the screw-jack- device 50, 53, 54 the instant at which the detent 31 snaps the pawl 23 into reversed position may be finely timed. The rack-unit 25, 42 is also easily and quickly adapted to variations which may obtain as between diiferent machines in respect to the spacing of the abutments or lugs 48 below the key-levers. The fine timing of pawl reversal may be so correlated to the operation of the usual carriage-feeding mechanism (not shown), operated by the usual heel 55 of the type-bar 16, that the fault of repeated printing is avoided.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a typewriting machine having frame side members, the combination with a row of laterallyspaced key-levers supported bet-ween said side members, of full-stroke devices including fullstroke racks, one for each key-lever, each rack adjacent its key-lever and extending in the direction of key-stroke, and a rack-supporting bridge attached to said frame side members, said racks being attached at their lower ends to said bridge and spaced therein according to the key-lever spacing, said bridge being spaced from and underlying said key-levers transversely.

2. In a typewriting machine having frame side members, the combination with a row of laterallyspaced key-levers supported between said frame side members, of full-stroke devices including full-stroke racks, one for each key-lever, each rack adjacent its key-lever and extending in the direction of key-stroke, a rack-supporting bridge spaced below and extending transversely of said key-levers, said racks being attached at their lower ends to said bridge to form a unit, and

spaced therein according to the key-lever spacing,

and means for attaching said bridge at its end to said frame side members, said means including devices arranged for micrometric adjustment of the bridge toward or from the key-levers, to finely adjust the position of the racks to the key-lever stroke.

'3. In a typewriting machine, the combination with a row of numeral-keys, of a full-stroke device including a plurality of two-armed pawls, one for each key, and pivoted thereon, the pawl-arms extending from opposite sides of the pivot substantially in the direction of key-strokes, a corresponding plurality of full-stroke racks, a common mounting member for said racks, and micrometric adjusting means engaging said member at two spaced points and thereby effective to finely adjust the row of racks in parallelism with the pawls and also in the direction of key-strokes, each rack having. formed thereon a pawl-shifting cam.

4. The combination with a reciprocatory keyoperated member, of a pawl pivoted on said member, said pawl having two arms extending to opposite sides of the pawl-pivot substantially in the direction of the member-strokes, said pawl being shiftable to call one arm or the other into action, a full-stroke rack for co-operatio-n with said pawl, said rack having two spaced series of pawl-engaging teeth for engagement with respective pawl-arms, and also having a pawl-shifting cam formed between the two series of teeth and effective for engaging and displacing one or the other pawl-arm to shift said pawl at the ends of the reciprocal member-strokes, and means arranged for micrometrically adjusting said rack in the direction of said strokes for closely adjusting the shift of the pawl by said cam.

5. The combination with a reciprocatory keyoperated member, of a pawl pivoted on said member, said pawl having two arms extending to opposite sides of the pawl-pivot substantially in the direction of the member-strokes, said pawl being shiftable to call one arm or the other into action,

a full-stroke rack for co-operation with said pawl, said rack having a pawl-shifting cam effective to shift said pawl at the ends of the reciprocal member-strokes, a detent device carried by said keyoperated member and operative to snap the pawl to position after a partial shift of the pawl by said cam, and means arranged for micrometrically adjusting said rack in the direction of said strokes for closely adjusting the instant at which said pawl is snapped to position by said detent.

6. In a typewriting machine, the combination with a key-lever having a horizontal arm extending transversely of the key-stroke direction, of a full-stroke device including a shiftable full-stroke pawl pivoted on said key-lever arm, a full-stroke rack for co-operation with said pawl, said keylever arm having a rack-guide spaced from said pawl and effective to retain one end of said rack in position for co-operation with said pawl, said rack being extended in key-stroke direction to a point substantially below said pawl and guide, and a mounting arranged below said key-lever arm, for holding said rack stationary relatively to the direction of key-stroke, said mounting having an opening arranged to receive the lower end of said rack, said lower rack-end having a shoulder abutting a face of said mounting and a removable key abutting the opposite face of the mounting, whereby said rack is rendered readily removable from and replaceable in said mounting.

'7. In a typewriting machine having a frame, the combination with a key-lever having a horizontal arm extending transversely of the key-stroke direction, of a full stroke device including a shif able full-stroke pawl pivoted on said key-lever arm, a full-stroke rack for co-operation with said pawl, said key-lever arm having a rack-guide spaced from said pawl and effective to retain one end of said rack in position for co-operation with said pawl, said rack being extended in key-stroke direction to a point substantially below said pawl and guide, a mounting arranged below said keylever arm to receive the lower end of the rack, and means attaching said mounting to said frame, said means being micrometically adjustable to adjust the elevation of said mounting to compensate for variations in the frames of different machines.

8. In a typewriting machine having frame side members, the combination with a row of key-levers having horizontal arms extending transversely of the key-stroke direction, of a corresponding row of full-stroke racks, a plurality of full-stroke pawls, one for each key-lever and pivoted on the horizontal arm thereof, each key-lever having guiding means spaced from said pawl and effective to retain one end of a corresponding rack in cooperative relation to the pawl, a rack-supporting bar extending transversely of and substantially below the key-lever arms, said bar arranged to support said racks in upstanding position, and abutments on said frame side members arranged for securing and supporting said bar, at its ends, below the key-levers as aforesaid, and for inserting and removing said unit by way of the bottom of the machine.

9. In a typewriting machine having frame side members, the combination with a row of key-levers having horizontal arms extending transversely of the key-stroke direction, of a corresponding row of full-stroke racks, a plurality of full-stroke pavvls, one for each key-lever and pivoted on the horizontal arm thereof, each rack having a pawlreversing cam, a rack-supporting bar extending transversely of and substantially below the keylever arms, said bar arranged to support said racks in upstanding position, abutments on said side members for supporting said bar, at its ends, below the key-levers as aforesaid, and a screw-jack device between each bar-end and its abutment, the screw-iack-devices being arranged for securing the bar to said abutments and for micrometrically adjusting the same up or down for proper operation of the pawl-reversing cams.

HENRY L. PITMAN.

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