US2567943A

US2567943A - Mechanism for varying the tension of normalizing springs of typewriters or like machines

Info

Publication number: US2567943A
Application number: US110534A
Authority: US
Inventors: John F Kloski
Original assignee: Royal Typewriter Co Inc
Current assignee: Royal Typewriter Co Inc
Priority date: 1949-08-16
Filing date: 1949-08-16
Publication date: 1951-09-18
Anticipated expiration: 1968-09-18

Description

Sept. 18, 1951 J. F. KLOSKI 2,567,943

MECHANISM FOR VARYING THE TENSION OF NORMALIZING SPRINGS OF TYPEWRITERS OR LIKE MACHINES Filed Aug. 16, 1949 2 Sheets-Sheet l Sept. 18, 1951 J. F. KLOSKI MECHANISM FOR VARYING THE TENSION OF NORMALIZING SPRINGS QF TYPEWRITERS OR LIKE MACHINES Filed Aug. 16, 1949 2 Sheets-Sheet 2 W \q II I INVENTOR JUH/V F. HLOSK/ BY fl M,

fie ATTORNEYS Patented Sept. 18, 1951 UNITED STATES orrica MECHANISM FOR VARYING THE'TENSION "or NORMALIZING SPRINGS OF TYPE- WRITERS R LIKE MACHINES 1..

corporationnf New-York Application August 16, 1949, serial No. 110,534

' Claims. (01. lin -s3) I This invention relates to mechanism for varying the tension -of normalizing springs of typewriter or like machines, and more particularly to mechanism for varying the tension of springs, the normalizing 'force of whichzhas to be overcome by 'finger pressure applied to the .space bar or keys of such machines, especially power operated typewriters.

The prior art is replete with devices for adjusting the tension ofsprings which function to return key levers of typewriter or like machines to normal-or non-depressed positions. The principal broad object of the present invention is to provide key or the like normalizing spring adjusting mechanism which is of novel and improved construction and arrangement, and which enables fine or close adjustments to be made without the use of intricate or expensive parts, or the maintenance of uneconomically close tolerances.

In some power operatedtypewriter constructions, a key is depressed to move an intermediate drive-transmitting element into engagement with a continuously operating driving member, whereupon the drive transmitting element is actuated so as in turn, to actuate an associated typewriter instrumentality, 'e. g, a type bar, carriage feeding or back spacing mechanism, or any of the other well known typewriter mechanisms. In some such machines, each key lever is provided with a normalizing or returning spring; and the associated intermediate or drive-transmitting mechanism is provided with one or more'additional normalizing springs for the appropriate parts. The arrangement is such that all of the normalizingsprings associated with a particular mechanism group, for example, atyping key, typ'e bar, actuating mechanismja'nd intervening connections, resist depression of the key, .In accordance with the present invention, the total normalizing force of a plurality of springs tending to resist depression of a single key is made accurately adjustable by providing mechanism for variably tensioning one or more but less than all of the springs associated with each key lever or other manually operable part. One of the objects of the invention is to provide a novel, simple, and 'eflicient mechanism for effecting such adjustments.

A further object of the invention is to provide novel and improved mechanism for adjusting the position of the normalizing spring anchor of a typewriter or like machine.

Other objects will become apparent from a reading of the following description, the appended claims and the accompanying drawings, in which:

, 2 Figure -1 is a view-,wpartlyinelevation part ly in vertical section, toreand-aft of a typewriter embodying the invention, showing only some of the conventional =orfst'andard typewriter parts order to illustrate the .-application of mechanism embodying the invention to a typewriter construction; I H A b 4 Figure 2 is a .-iragmentar-y iore-and-aft section-a1 view of thespring tension adj usting mechanism-lshown in Figure '1, drawn on an enlarged scale,-the section being on the 'line -2--2 of Figure '3;

Figure 3'is :a horizontal sectional view on the line 3 3' of {Figure :1,- drawn onan 'enlargediscale, with somepartsomitted;

Figure 415 a detail perspective iviewof-an indicator sector ineluded in .the construction disclosed in'Figures 1,a2; :and 3; Figure 5 is a vertical fore-and-iaft :sectional view similar to Figure -2'but showing a modified construction; and.

Figure 6 is a :viewa-lso similar to Figure '2 but showing atiurthermodified construction.

The invention may :bezemb'odied in typewriters or ilike machine of various ..=kinds. For :the Spunpo'se's'rof illustration, the invention :is shown as being embodied in an ioffice rtype wpewriter hav' ing, except iior the powerime'chanism and spring tension adjusting mechanism to be *described, many features in common with the well known Royal Standard typewriter. The drawings show onlyaen'ou'gh of thestandard or known typewriter construction 'tofa'ssi-s't in illustrating the manner in which mechanism embodyin the invention may be 7 coordinated' wi th other-parts of "a was: Writer construction.

I The known con'strtiction illustrated incl-tides a a sewage B -'eq'u'ipped V n C ismoiinteii for letter spacing return-movementsbymeans or a top rail 1 se cured :to the -fiari'ciagfe, and rolling upon balls 2,

which in tam are adapted to roll on a namemounted bottom raiPortrao'k 3. v

The carriage mayfbe driven towardlth'edft, that is, .in the"letter-'spa'cing direction, by any suitable mechanism, "for jeiiample, *by' a spring barrel and draw band oi'known or suitable asistruction (not shown), un'derfthe contij'ol off'suitable escapementfmechanism operated,.-'for exam} ple, as disclosed in the copenciing application (if Henry :J. Hart, serial. 1983138, I'fild June .13; 1949 (now Patent No. 2,563212-2, aated Ai 1gilSt 7, 951), K 7, I r Returning pf tl ie-carriagestowardtheright may be effected by power controlled :sfrom the typewriter keyboard, for example, by mechanism or the kind disclosed in the copending application of Henry J. Hart, Serial No. 21,476, filed April 16, 1948.

The machine is provided with the usual complment of type bars, one of which is shown at 4 in Figure 1 as being pivoted at 5 on a support or segment 6 equipped with a type bar abutment or banking ring 1. Normally the type bar 4 is in the position shown in Figure 1 with the type head resting upon a cushion 8. The type bar segment 6 may be shifted to upper and lower case positions by any suitable mechanism, for example, by power-operated mechanism of the kind shown in the copending application of William H. Kupper, Serial No. 133,322, filed December 16, 1949.

Power for operating the type bars or other instrumentalities is supplied by an electric motor (not shown), which drives an actuating mechanism generally designated D. The mechanism D is generally similar tomechanism described and claimed in copending application Serial No. 98,738'referred to'above,-and is similar to but embodies improvements in mechanism disclosed in the copending application of William H; Kupper, Serial No. 6.066, filed February 3, 1948. It includes a continuously operating driving member and controllable driving connections, which normally are-inoperative or ineffective; but which may be conditioned by the operator to effect operative driving connection between the continuously moving driving member and the instrumentalitiesto be operated. The driver is constituted by a continuously rotating element, more particularly a toothed snatch roll or bar 9, which may be of known form, and which is adapted to be driven in the direction ofthe arrow ain Figure 1.

The mechanism for transmitting drive from the driver 9 to each of the type bars 4 includes an actuator 10 which extends fore-and-aft of the typewriter and above the member 9. The actuator 19 is pivoted as at H to a lever 12 at a point oifset relatively to the pivotal mounting 13 of the lever on a fixed frame cross bar 14. Theactuator hasa forwardly extending part l5 projecting under an abutment or guide plate l6 mounted by screws 11 on the frame, A to extend parallel to the snatch roll 9. The downwardly extending part [5 of the actuator I projects through a slot (not shownlin the lower guide plate 18 which issecured to the frame by the screws I1. The actuator part I is cooperable with an adjustable knock-oif plate or member l9 for a purpose to be described hereinafter.

A normalizing spring 20 is interposed between the front end of the actuator and an anchor plate 2| securedby screws '22 to a fixed cross bar 23. The spring 20 normally maintains the actuator 19 in the positionshown in Figure 1 withthe front end of the actuator immediately below the upper guide plate 16.

The guide plates l6 and I8 and the spring anchor 2| extend across the front of the machine, the guide plates being cooperable with other actuators and associated parts similar to the actuator 10 and its associated parts, and the anchor 21 serving to anchor springs connected to the other actuators and corresponding to the spring shown in Figures 1 and 2.

A link 24, pivotally connected to the lever l2 and the heel of the type bar 4 at 25 and 26 respectively, causes the type bar to be driven clockwise to printing position when the lever 12 is rocked counterclockwise in the manner described below.

In order to apply a power impulse to the ty e bar 4, the actuator 10 is operatively but indirectly connected to the driving member 9, the actuator itself neyer engaging the driving member. Mechanism for bringing about the operative connection of the actuator element ID to the member 9 includes an interponent pawl 21, pivoted as at 28 on the actuator. A spring 29, anchored to the actuator 10 and connected to the pawl 21, biases or urges the latter to rock clockwise so as to move its nose 21 into engagement with the snatch roll 9. Normally, the pawl is maintained out of engagement with the snatch roll by the restraining action of a control element or trigger 30 which is pivoted as at 3| on the actuator Ill. In the normal position of the trigger, its rear end 32 engages a holding surface 33 on the pawl so as to prevent the spring 29 from rocking the pawl element 21 into transient drive-transmitting engagement or connection with the driving member 9. The pawl 21 is formed with an inclined resetter cam face 34 which is located just below the holding surface 33; and which is acted upon by the trigger for rocking the pawl counterclockwise, and thus resetting it in normal, inoperative position.

Operator controlled means including a manually operable key 35 pivoted at 36 on the frame A is provided for bringing about operative driving connection between the driver 9 and the actuator 10. The key 35 has an upward projection 31 disposed behind an arm 38 of an operating lever 39, pivoted as at 49 on the frame-mounted cross bar 23.' The lever 39 has another arm 4| on which a limber dog or flipper 42 is pivoted at 43. A spring '44 urges the limber dog 42 to rock clockwise to yieldably retain it in its normal posi-,- tion of rest against a limit stop 45 and above an ear 46 on the actuator 19. The dog 42 can swing counterclockwise from the position shown in Figure 1, but cannot move clockwise from this position.

A normalizing or returning spring 41 is connected at its lower end to the intermediate lever 39, and at its upper end to a spring anchor 48 secured to the cross bar 23 by the screw 22. The. anchor 48 extends transversely of the machine so as to provide an anchorage for springs corresponding to the spring 41 and connected to other intermediate levers such as the lever 39 shown in Figure l. The spring 41 normally holds the intermediate lever 39 in the position shown in Figure 1, so that the lower end of the flipper 42 is positioned just above the ear 46 on the actuator 19.

The key lever 35 is normally held inelevated position by a normalizing spring 49, the lower end of which is connected to an ear 50 on the key lever, and the upper end of which is con-' nected in an aperture 5| formedin an anchor plate 52 which may be adjusted to vary the tensioning of the spring in a manner to be described hereinafter. -In operation, when the key 35 is depressed, the lever 39 is rocked clockwise to cause the flipper 42 to push the actuator I0 downwardly to an initial extent sufficient to bring thetrigger 39into engagement with the abutment 18. This causes the trigger to be rocked clockwise about its pivot 31, so as to release the pawl 21,.which is then moved by the spring 29 into engagement with the snatch roll 9. The snatch roll then drives the pawl 21 and actuator ID as a unit so as to rock the lever 12 and operate the link 24 and type bar 4. When the pawl 21 is cast off active position. The parts will then be returned 7 to their normal positions by the coaetion of, the

springs

20 and 41 and a spring 53 interposed Betwe'euthe rear of the frame" A- and a fink 54 connected to the lever 12.

{Means of the disclosed in thelcopenw 'i'ng application of Henry J. Hart, siil iallNQ 102,634,- are provided for'adjustingorvaryingthe amount -of driving impulse delivered to the in,-

dpawl 21 by the snatch roll 9. "The indi-vidual variation or adjustment is effected-by variably limiting the extent to which the actuator pawl nose 21 enters a tooth inters csa'ce on the'snatch roll 9 under the urge of the spring ifwhen the restraint of the trigger- 39 on the paw/r 21 is discontinued. In the form shown, the actuator It is provided witha-downwardly extending stop element or finger which is disposed in front of and normally out of contact" with a downwardly extending stop part, heel, or finger 56' on the pawl 21. When the pawl -21 is rocked clockwise by the spring 29* so as to move the pawl nose 21 into a "snatch roll "tooth interspace, the pawl stop '55 moves toward theactu'ator stop55, which may be so positioned to be engaged by the stop 56 to arrestrockmg-of the pawl '2'! before the tooth Thmcves to' the root of the snatch roll tooth interspace. fiyvariably positioning cheer the stops 55555, e. -g"., by bending the stop 55 towards or away fromthe stop 56-, the extent to which the pawl tooth "21 enters the tooth interspace can-be varied. Consequently, the angle through which the snatch roll rotates while in contact with the-pawl, which determines the amount of drivi n'g of the" pawl 21 and actuator II by the snatch roll 9, can b'e varied.- Any suitable'means or construction may be provided for adjusting one of the-stops 55, -56 relatively to the other. In' the preferred construction the stop 55' is formed irrtegral-ly with 'the actuator so 'as to be bend 'aloletoward or away from the "stop-56.

In typewriters or like machines in which all 'or'some of the instrumentalities to be operated,

mecharrism, tabulating mechanism, as wellas g escapement mechanism, carriage return typing mechanism, are operated-by power, it is This may be accom- Figure 1. Any suitable means (not shown) may be'provided for adjustably tilting or otherwise va'ria'bly positioning theknock-ofi bar 1 9 so that it will be engaged by the lower ends of the act'uators to control the timing 'of disengagement of. the associated actuator pawls fromthe snatch r011.

In-order to avoid congestion of the parts at the front of the machine, principally the-key "fevers and space bar, the key levers 35 are mounted, some on the :upper'pivot rod 35 and othersoii a lower pivot 51 as shown'in Figure 1, "arrangement being described: more fully *in the spring anchor 52. Figures 1-to4, a U-shaped bracket 65 is secured -to=the front frame cover by screwsjone-of the mpending application-of William Kupper'. 'figlififievpreviously referred to. keysronisome of the 'keylovers 3!: arelocated more. distantly fromthe associated pivots than therkeys-cn otheriofthe key levers. To com-- perxsate ion the diffierences leverage so as to provide rsubs-tazrtial uniformity of touch--,-or resistancerto r-key depression, the key lever=returning-.springs liif may have-different characteristics-so as to exert difierent' key raising. or normalizing efforts. wTh'llS, the springs connected to the key levers having keys on the --first'--,or lower bank of keys:-may be somewhat stronger thani'the springe tor returning-501' normalizing theikey .:levers having keys in the second bank. ;.:.It-nwi1l be seen-"that alt of the springs asso- "ciated Withieach key lever 35, namely, the actuator normalizing. spring '20-, the intermediate lever normalizing spring 41, and the key lever normalizing; spring 49, resist depression of the-key I'VGEL: *In acco'rdan'ce with the present invention, the touch or force-needed to beexerted on a k'ey for actuating the associated mechanism-4s regulated by varying or adjusting the tension of less-thar'rall of the associated three springs. the-form shown Figures 1 to- 4; thetouch is' regul'atcd; by adjusting or -varying the tens-ion of "only once-of: the three springaspecifically;the spring. 49" connected between the key lever-and the/anchor 52.

Such adjustment is effected by changing-the position of the'anchor 52 bymecha'nismhow'to be described. The anchor 52 isintheform-ofa plateextending transversely of the machineahd ham-pg a part-58" wrapped around a rod 59 and secured to the-rod. by pins 58. The-rod- 59 pivot end portions 60' which extend through re pivotedin openings in bearing plates B l secured byscrews'fl -to brackets 63 mounted on-"the main frame A. The brackets 63*are formed with-open-end slots' fi'l which receive the pivot parts 60 of the rod 59.. Because of the slots 64 being open at their front ends,- the "anchor assembly 5 2-'59 may readily be dismounted from thebrackets 63 by removing the screws62 so as to free the plates 6 I. The brackets '63 support the knock-off bar 19- arTT' the cross bar 2-3 previously referred 'to.

When the anchor 52 is rocked clockwise "as viewed-'inFigures 1 and 2, thesprings 49 are stretched or additionally tensioned so asto require aheavier or increased touch for operating thekey lever 35 and the associated intermediate lever 39 and actuator ID. Conversely, when the anchor'52 is rocked counterclockwise, the spring ""49" is permitted to contract so as to 'reduce lt tension. thereby providing foroperati it a lighter touch.- Close controlof the -v'ariation m the touchrequ'iredis made possible by varying thdtensidn ofonly one of the springs opposing depression of the key lever 35", the arrangement 'being such that considerable movement of the jumpy or erratic changesin the touch regulation.

Improved mechanis is provided for rocking In the form shown in which is shown at 6]. The upper andlowenlegs of. thebracket provide bearings for a. shat-t 7 formed at itslower end with ascreworrworm thread 69. A shoulder :18 on the shaftGB abuts the upper leg of the bracket 65 to hold the shaft 68 against upward .movement, and a. knob. 11 secured-to the top of theshaft 88 .by set screws H holds the shaft against downward movement. A worm wheel sector-12 secured to the anchor rod 59 by aset screw 13 is formed with a series of teeth'meshing with the worm teeth 89, so that, upon rotation of the shaft 68 by the knob. 11, the sector 12 and the anchor ;52 will be rocked about the axis of the pivots 68 so as to vary the tension of the spring 49.

; In order to limit rocking ofz theanchor 52 and to prevent over-or under-stressing of the springs 49, thesector 12 is formed with stopportions and 15 (Figure 2) at the respective ends of the series of sector teeth onthesame are and diameter as the crests of theteethn When the 'partsare in a limit position, as shown in Figure 2,- anupper threadconvolution of the worm 69 .willbear against the stop portion -15so as to prevent further rotation ofv the knob H and rocking of-the-anchor 52, thus preventing over-stressing of the springs 49. Similarly, when the sector'12 is'grocked counterclockwise to its opposite limit position, a lower thread convolution on the worm .69, will bear against the other stop portion 14 so as, to prevent further rockingof the anchor 52. The stop portions 14 and 15 serve not. only to limit the adjusting of the springs 49, but also to prevent the worm 69 and sector teeth from being unmeshed. I H In orderthat the operator may be. informed {as to the touch regulation, an indicator sector 16 issecured tothe spring anchor rod 9.by means :of a set screw 11, and is, provided peripherally with scale marks 18 viewable througha window or opening 19 above which is a pointer 88, adapted to register with a scale marking. 18 for indicating the particularsetting or adjustment of the tension of the returning springs 49. Y

. In the modification shown in Figure 5, the

key mechanism

35, 36, intermediatelever 39, and acmating-mechanism including the actuator I8 are ,thesame as are shown in Figure l, and are shown gonly partiallyin Figure 5.. The mechanism shown in Figure 5 differs from that previously described in that-the key'lever normalizing spring 49 is under constant tension, whereas the actuator normalizing spring 28 and the intermediate lever normalizing spring 41 are arranged to beadjusted. The Figure 5 construction, however, is similar to the construction shown in Figures 1 mam that lessthan all. of the springs which fresist the depression. of the associated key are adjustable, so that a smooth, dependable adjust- "ment' or regulation of the touch is obtainable. As shown in Figure 5, an adjustable spring anchor {8| is provided with ears,- one, 82, of which is shown, pivoted ona rod 83 carried by ears, one of f'which is shown at84 extending forwardly from Ftheframe cross bar 23. The rod 83 serves not "only as apivot for the anchor 81, but also as an upper anchorage for the non-adjustable key.

lever normalizing springs 49. The anchor BI is formed with holes 85'for attachment of the upper ends of the springs 28 and 41.. .1

Mechanism for rocking the anchor 8| includes '-a bracket'86 secured by a screw 81 to the front mask panel 66, and an internally threaded sleeve 588 extending throughwhich is an adjusting screw 89, The partsare so' mounted that the screw axis extends upwardly and forwardly with respect to-the machine. A'clevis 88 is mounted on the .part I by screws I2I.

8 I lower end of thescrew 88 by a connectioncomprising a roove 9| in the screw, and a pin 92in the clevis extending tangentially through the groove so as to permit relative rotation ofthe screw and clevis, but so as to constrain the clevis to partake of the translatory movement of the screw. A coupling pin 93 extending transversely through the clevis 98 is encompassed by the wrapped end 94 of, a leaf 95 riveted as at 86 to theanchor 8|. A. knob 91 is secured to the upper end of the screw 89 by a set screw 98, and is formed with a frusto-conical circumferential part 99 provided with scale markings I88 which may be read in connection with a fixed pointer. I8I secured to the front maskpanel 66 by the screw .81. By rotating the knob 81, the screw is caused to move upwardly or downwardly so as to rock the anchor 8| about its pivot 83,, thereby'increasingfor decreasing the tension of the normalizing

springs

20 and 41. Theinclination of the frusto conical scale portion 99 facilitates observation or reading of the scale-indicated adjustment of the spring tension, and hence facilitates setting the touch control mechanism. v

The modified construction shown in'Figure G is adapted for use in connection with keymech'a nism, intermediate lever mechanism, and actuator mechanism of the kind disclosed in Figure .l, andonly apart of the actuator I8 is shown. In this embodiment of the invention, only one of thethree normalizing springs, namely, the actuator. normalizing spring 28, is adjustable. A bracket I82 secured to the frame crossbar 23 is formedwith a fixed front anchor I83 for the key lever normalizing springs 49, and witha fixed rear anchor portion I84 forthe intermediate lever normalizing springs 41. The bracket I82 has an upper part I85 secured to the front frame panel 86 by a screw 186. Ears, one of which is shown at. 181, on .the bracket I82, support a pivot rod I88 on which 'are'pivoted ears, one of whichi's shown at I89, extending downwardly from an adjustable anchor IIU for the actuator springs 28. The tensionin of the springs 28 is adjusted by rocking the anchor 'I I8 by mechanismincluding an ear III on the bracket I82, on which is mounted a pivot screw I I2 for a manually adjustable arm or lever I I3. Alink I I4 is pivoted at I15 to th arm H3, and 'is pivoted at .I IE to an ear I I1 -on an extension I I8 of the anchor I I8. Rocking of the arm I I3 about its pivot I I2 acts through the link I I4 and extension I I8 to rock the anchor H8 so as to increase or decrease the tension of the springs 20, according to the direction in which the arm I I3 is rocked. In'orderthat the arm II 3 will be retained releasably. in a selected or set position of adjustment, it is formed withja plurality of flat ,ohordal parts II9'contactable with a leaf spring I28. secured to the bracket upper An indicator segment I'I2 secured to the bracket upper part I85 and the front mask panel 66 by the screw I88-is formedwith three raised indicator or. guide parts 123 for assistingrtheoperator in determining the set or adjusted position of the arm I I3, and hence the tensioning of the springs 28 and the'touch regulation. I a I Preferred embodiments of touch control mechanism constructed in accordance with, the invention have been describ'ed as applied to the "type ing keys of a typewriter. Mechanism embodying the invention, however, maybe and 15mtended to' be used in connection withthe other keys of typewriter or like machines, suchas'the space bar I24, shift key I25, and back spacing key 126, all of which are indicated in Figure 1. Itmay also be: applied in connection with such other auxiliary or service keys as the shift lock key,.tabular key, margin release key, and the carriage return key of a power operated typewriter. 7

Because of the dependable and close regulation of the touch which can be accomplished with mechanism .embodying the present invention, such mechanismrhas particular utility in connection with power operated typewriters constructed for operation with a touch lighter than normally is required in operating a conventional manually operated machine. When anexperienced operator, accustomed to using a. manually operated typewriter, first uses a power operated machine, the operator mayfind the touch unsatisfactorily or..unpleasingly light. During transition from manual machine operation. to powered machine operation, it may be desirable to set the touch regulating mechanism so as to require a key pressure not too much less than is required in the use of a manually operated machine, and thereafter to decrease the pressure from time to time until full advantage of the light touch characteristics of a power operated typewriter can be realized to the satisfaction of the operator. For this reason, and because of the very close and reliable key pressure regulation obtainable with mechanism embodying the invention, the invention is particularly, although not exclusively, adapted for use in power operated typewriters.

The constructions shown and described embody the invention in preferred forms, but. it is in tended that the. disclosure be. .illustrative rather than definitive, the invention being defined in the appended claims.

I claim:

1. In a power operated typewriter or like. machine, a power driven member; instrumentalities to be operated by said member; actuators respectively connected to. said instrumentalities; a spring anchor; a set of normalizing springs con-' nected to said anchor and respectively connected to" said actuators for .yieldably holding said actuators disconnected from said member; means including key levers for moving said actuators selectively against the urge of the associated normalizingsprings into engagement with said member; another spring anchor; a set of normalizing. springs connected to said. other spring anchor andrespectively connected to said key levers; means mounting. one of said anchors pivotally to rock about an axis oifset from the points of connection of the associated springs thereto; a worm wheel sectorpconnected to the pivotally mounted anchor; and a manually rotatable worm cooperable with said worm wheel sector for rocking thepivotally mounted anchor to vary the normal tensioning of the springs connected; thereto.

2. In a power operated typewriter or like machine,.a power driven member; instrumentalities to bev operated by said member; actuators respectively connected to said instrumentalities; a spring anchor; a set of normalizing springs connected to said anchor and respectively connected tosaid actuators for yieldably holding said actuators disconnected from saidmember; means including key levers for moving said actuators selectively against the urgeof the associated normalizing springs into engagement with said member; another. spring anchor; a set of. normalizing springs connected to said other spring anchor and respectively connected to said key levers; means mounting one of said anchors pivotally to rock about an axis offset from the points of connection of theassociated springs thereto; a worm wheel sector connected to the pivotally mounted anchor andhavinga series of teeth and, stop portions respectively at the ends of the series and on. the same are andldiameteras the crests of the teeth; and a manually operable worm meshing with said sector teeth and being cooperable therewith for rocking the pivotally mounted anchor to very the tensioning of the springs connected thereto, said stop portions beingenga'ge'able by the worm teeth for determining limits of rocking of the pivotally mounted anchor.

3. In a power operated typewriter or like machine, a power driven member; instrumentalities to be operated by said member; actuators respectively'connected'to said instrumentalities; a spring anchor; a set of normalizing springs cone nected to said anchor and respectively connected to said actuators for 'yieldably holding said actuators disconnected from said member; means including key levers for moving said actuators selectively against the urge of theassociated normalizing springs into engagement with said member; another spring anchor; a set of normalizing springs connected to said other spring anchor and respectively connected to said key levers; means mounting one of said anchors piv otally to rock about an axis offset from the points of connection of the associated springs thereto; a fixed, internally threaded sleeve; a manually rotatable screw having threaded engagement with said sleeve; and means connecting said screw to the pivotally mounted anchor for rocking the latter in consequence of translatory move ment of thescrewcaused by manual rotation thereof.

4. In a poweroperate'd typewriter or like machine, a power driven "member; instrumentalities to be operated by said member; actuators respectivelyconnected to said instrumentalities; a spring anchor; a set of normalizing springs con-'- nected' to said anchor and respectively connected to said 'actuators'for yieldably holding said notu'ators disconnected from said member; means including key levers for moving said actuators selectively against the urge of the associated normalizing springs into engagement with said member, another spring anchor; a set of normalizing springs connected tosaid other spring anchor and respectively connected to said key levers; means 'mounting one 'of said anchors pivotally to rock about an axis offset-from the points of connection of the-associated springs thereto; a pivotally mounted, manually operable adjusting arm connected to thepivo'tally mounted anchor for rocking the latter to vary the normal tensioning of the springs connected'thereto, said arm being formed with a plurality 'of' fiat surfaces.v substantially chordal with respect to the arm pivot axis; and a leaf spring adapted to bear against any one of said surfaces, according to the position of said arm, for yieldably holding the'latter in set adjusting position.

5. In a power operated typewriter or like machine, a power driven member; instrumentalities to be. operated by said member; actuators respectively connected to said instrumentalities; a sprin anchor; a set of normalizing springs connected to. said anchor and respectively. connected: to. said actuators, for yieldably holding said actuators disconnected from said member; means including key levers for movin said actuators selectively against the urge of the associated normalizing springs into engagement with said member; another spring anchor; a set of normalizing springs connected to said other spring anchor and respectively connected to said key levers; means mounting one of aid anchors pivotally to rock about an axis offset from the points of connection of the associated springs thereto; a pivotally mounted manually operable adjusting arm; means including a link connecting said arm to the pivotally mounted anchor for rocking the latter when the adjusting arm is rocked to vary the tensioning of the springs connected to the pivotally mounted anchor, said arm being formed with a plurality of fiat surfaces substantially chordal with respect to the arm pivot axis; and a leaf spring adapted to bear against any one of said surfaces. according to the position of said arm, for yieldably holding the latter in set adjusting position.

- 6. In a power operated typewriter or like machine, a power driven member: ,instrumentalities to be operated by said member; actuators respectively connected to said instrumentalities; a first spring anchor; a set of normalizingsprings connected to said first spring anchor and respectively connected to said actuators for yieldably holding said actuators disconnected from said member; means including key levers for moving said actuators selectively against the urge of the associated normalizing springs into engagementwith said member; another Spring anchor; a set of normalizing springs connected to said other spring anchor and respectively connected to said key levers; means mounting said first spring anchor pivotally to rock about an axis offset from the points of connection of the associated springs thereto; and manually operable means for rocking said first spring anchor to vary the normal tensioning of the springs connected thereto.

'7.'A construction as set forth in claim 1, in which the springs connected to the key levers are connected to the pivotally mounted anchor.

8. A construction as set forth in claim 3, in which the springs connected to the actuators are connected to the pivotally mountedanchor.

9. A construction as set forth in claim 4, in which the springs connected to the actuators are connected to the pivotally mounted anchor.

10. In a power operated typewriter or like machine, a power driven member; instrumentalities to be operated by said member; actuators respectively connected to said instrumentalities; a first spring anchor; a set of normalizing springs connected to said anchor and respectively connected to said actuators for yieldably holding said actuators disconnected from said member; key levers; intermediate levers respectively interposed between said key levers and said actuators and being responsive to key lever depression for moving said actuators selectively against the urge of the associated normalizing springs into engagement with said member; another spring anchor; a set of normalizing springs connected to said other spring anchor and respectively connected to said key levers; a set'of normalizing springs connected to said first spring anchor and respectively connected to said intermediate levers; means mountin one of said anchors pivotally to rock about an axis offset from the points of connection of the associated springs 12 thereto; and manually operable means for rock-,- ing the pivotally mounted anchor to varyv the normal tensioning of the springs connected thereto. I

11. A construction as set forth in claim 10, in which said first spring anchor is pivoted and said other spring anchor is at the pivotal axis of said first spring anchor. g I 12. A construction as set forth in claim 10, in which the springs connected to the intermediate levers and the actuators are connected to the pivotally mounted anchor. g

13. In a power operated typewriter or like ma chine, a power driven member; instrumentalities to be operated by said member; actuators respec tively connected to said instrumentalities; a spring anchor; a set of normalizing springs connected to said anchor and respectively connected to said actuators for yieldablyholding said actuators disconnected from said member; key levers intermediate levers respectively interposed be tween said. key levers and said actuators and being res onsive to key lever depression formoving said actuators selectively against the urge of the associated normalizing springs into engage ment with said member; a second spring anchor; a set of normalizing springs'connected to said second spring anchor and 'respectively'connected to said key levers; a'third spring anchor a setof normalizing springs connected to said third spring anchor and respectively connectedto said intermediate levers; means mounting'one of said anchors pivotally 'to rock'about an axis offset from the points of connection of the associated springs thereto; and manually operable means forro'cking the pivotally mounted anchor to vary the normal tensioning of the springs connected thereto. 14. In a typewriter or like machine,'instrumentalities to be operated; means including key-operated levers for effecting operation of said instrumentalities selectively; a spring anchor; a set of springs connected to said anchor and respec-'- tively connected to said levers; means mounting said anchor pivotally to rock about an axis onset from the points of connection "of said springs thereto; an internally threaded sleeve fixedly mounted on the machine adjacent the front thereof and with its axis being inclined forwardly and upwardly with respect to the"ma'chine;'fa screw having threaded engagement 'withsai'd sleeve; means connecting the lower'end of said screw to said anchor for rocking the latter in con sequence of translation of said screw caused by rotation thereof; a manually rotatable knob secured to the upper end of said screw and having a scale-marked frusto-conical peripheral portion; and a fixed pointer cooperable with the scale markings for indicating the rotated position of said knob and screw and hence the rocked position of said anchor and the degree of tensioning of said springs. i i 15. In a typewriter or like machine, instrumentalities to be operated; means including keyoperated levers for effecting operation of said instrumentalities selectively; a spring anchor; a set of springs connected to said anchor and respectively connected to said levers; means mount ing said anchor pivotally to rock about an axis offset from the points of connection of said springs thereto; a pivotally mounted, manually operable adjusting arm connected to said anchor, said arm being formed with a plurality of flat surfaces substantially chordal with respect to the arm pivot axis; and a leaf spring adapted to bear 13 against any one of said surfaces. according to the position of said arm, for yieldably holding the latter in set adjusting position.

JOHN F. KLOSKI. 5

REFERENCES CITED The following references are of record in the file of this patent:

Number 14 UNITED STATES PATENTS Name Date Hess Aug. 4, 1908 Crawley May 15, 1923 Ellis May 26, 1925 Hokanson Jan. 18, 1927 Myers Aug. 15, 1939 Yaeger Sept. 2, 1941