US2861669A - Power impulse control for type actions - Google Patents

Description

Nov. 25, 1958 c. B. LETTERMAN POWER IMPULSE! CONTROL FOR TYPE ACTIONS 5 Sheets-Sheet 1 Filed June 28, 1956 INVENTOR CHARLES E. LETTERMAN ATTO R N EY Nov. 25, 1958 C. B. LETTERM AN A POWER IMPULSE CONTROL FOR TYPE ACTIONS INVENTOR 4 CHARLES B LETTERMAN 3 Sheets-Sheet 2 Filed June 28, 1956 BY 4 ATTORNEY Nov. 25, 1958 c. B. LETTERMAN 2,851,669

POWER IMPULSE. CONTROL FOR TYPE ACTIONS Filed June 28, 1956 5 Sheets-Sheet 3 INVENTOR CHARLES B. LETTER/WIN ATTORNEY United States Patent l POWER IMPULSE CONTROL FOR TYPE ACTIONS Charles B. Letterman, West Hartford, Conn., assignor to Underwood Corporation, New York, N. Y., a corporation of Delaware Application June 28, 1956, Serial No. 594,490

6 Claims. (Cl. 197-17) This invention relates to strength-of-imprint controlling devices in power driven typewriting machines in general and particularly also relates to .such typewriting machines which embody type action actuators which are rendered active by selectively connecting them operatively with a continuously operating or rotating power member, or roll, whereby the type actions receive power operating impulses.

Such machines usually embody an element which is universal to all type actions and which is adjustable to vary predeterminedly the magnitude or the intensity of the type action operating power impulses. The particular kind of machine in connection with which the invention has been developed, embodies type action power actuators which stand normally clear of a toothed power roll and which are individually rendered active by movement selectively into toothed, motion-receiving relation with such roll. Each actuator, in receiving motion from the power roll, engages at a certain point in its operation an adjustable abutment carried on a common supporting bar and is deflected resultingly clear of the power roll. This might be termed a divorcement of the actuator from the power roll, and after such divorcement the type action completes its typing stroke or cycle under power of momentum stored in its parts. By adjustment of the abutments related to the individual type actions, the power impulses of the type actions are variable individually and by adjustment of the abutment supporting bar the power impulses are adjustable collectively for all type actions. The stated bar is adjustable at will by an impression regulator, thereby to vary universally the power impulses for all type actions. Since the upper-case types have printing faces which in respect to the related lowercase types are generally of somewhat larger area it fol lows that for uniform texture of upperand lower-case type impressions, the type actions need slightly longer or intensified power impulses for typing upper case characters. There arises the additional condition that whenever a ribboi'i'vibrating mechanism is set for a greater extent vibration, as called for in connection with typing by .a lower ribbon field, the typing impulses need lengthening or intensification to compensate for the dissipation of a greater amount of energy in the momentum phase of movement of the action to printing position.

It is a paramount object of the invention to provide an efficient power operated typewriter which under any operating condition of the machine and for any regulation of a manually adjustable imprint control will yield imprints of uniform tone or texture.

It is also an object of the invention to provide in a power operated typewriter efliciently operative means to vary or govern accurately and eificiently the power typing impulses under control of the case-shift mechanism, the

A 2,861,666 Patented Nov. za sss 2 such cases in conjunction with a greater or a lesser vibra-' tion of the ribbon.

It is a further object of the invention to provide reliably controlling, substantially unyielding mechanism whereby to effect the stated mutually complementing impulse governing adjustments.

Another object of the invention is to provide for the various stated impulse governing adjustments in a reliable, efiicient manner by parts which are constituted and arranged to exert accurate and positive control under all operating conditions of the machine.

It is also an object of the invention to attain the foregoing objects in a simple and economical manner.

Still many other objects and features of the invention will be apparent upon consideration of the detailed description which follows, as such description is read in the light of the accompanying drawings.

The invention is illustrated in connection with a type action system of the kind disclosed in the patent to Yaeger No. 2,254,764, dated September 2, 1941. It has also relation to the patent to Sagner No. 2,369,315, dated February 13, 1945, and the patent to Dorsey No. 1,818,200, dated August 11, 1931. Furthermore, the invention is an im provement over a copending patent application by the present applicant, Ser. No. 363,441, filed June 23, 1953, now Patent No. 2,757,774, dated August 7, 1956.

Referring now more particularly to the drawings,

Figure 1 is a fractional side view of the machine embodying the invention, from the right side thereof.

Figure 2 is a light-hand front perspective view of a ribbon bichrome setting mechanism figuring in the invention. 1

Figure 3 is a fractional front view illustrating in detail some of the parts of an impression regulating mechanism seen in Figure 4.

Figure 4 is a front sectional view taken substantially along a line 4-4 of Figure 1.

Figure 5 is a fractional side view looking leftwardly against the machine and illustrating portions of a case shift mechanism in conjunction with the impression regulating mechanism.

Figure 6 is a fractional front view depicting a manually settable impression control.

Finally, Figure 7 is a right-hand side elevation of the impression control of Figure 6 and certain parts con-- trolled thereby.

The invention is illustrated in connection with a power typing mechanism which corresponds substantially to the one of the above noted patent to Yaeger. It includes a toothed power shaft 12 which is generally coextensive with the width of the machine and turns continuously in the direction of the indicated arrow when the electric cur-- rent is turned on for the machine. The power shaft 12 is common to a usual complement of laterally distributed type actions which each includes a power actuator 13 normally posed clear above the power shaft 12 as shown in Figure l. The said actuators 13 include each a pivoted snatch pawl 14 and are at their front ends pivotally connected to arms 15 pendant from a transverse pivot rod 16. A transverse bar 17 supports said rod 16 and is slotted to accommodate the arms 15 in laterally spaced relations. Springs 18 urge the actuators individually upwardly and rearwardly so that their snatch pawls 14 lie normally clear above the teeth of the power shaft 12, upwardly against a crossbar 20, and so that the arms 15 rest rearwardly to the limit of the slots in the bar 17. Each of the arms 15 is adapted to operate an upstanding sub-lever 21 by rolling lever contact therewith as at 22, the subl'evers being pivoted on a transverse rod 29. The upper ends of said sub-levers 21, by links 23, are individually connected with type bars'24, the latter provided in a usual arcuate array for operation to a common printing point indicated at 26, against a platen 25. The type bar shown in Figure 5 is one at the middle of the system and is in normal position. In Figure -1, the same type bar is indicated in dot-and-dash lines, moved partially toward the printing point 26.

The actuators 13 are selectively movable into motion receiving relation with the toothed power shaft 12 under.

control of type keys, not shown, each key having a hook element 27 overlying a lug on one of the .actuators 13. Therefore, when any key is operated, its associated actuator 13 is drawn down, engaging its related snatch pawl 14 with the power shaft 12. In a usual manner, the power .roll then first turns the snatch pawl 14 limitedly on the actuator for securing a firm mesh, and then the snatch pawl moves the actuator 13 forwardly to operate the parts 15, 21 and 23 and thereby to operate the type bar 24 toward the printing point 26.

At a variable point in the movement of the type bar toward the printing point the actuator 13 is cammed upwardly and divorces the snatch pawl from the power shaft 12. The actuator 13 is then restored to the normal position seen in Figure 1 by its spring 18, the operated type bar 24 however concluding its movement to the printing point 26 under power of momentum, and a spring 37 associated with the sub-levers 21 finally becoming effective to return it and the type bar.

To the end of elfecting the automatic divorcement, each actuator has a rearwardly extending finger 28 provided with a downwardly and rearwardly inclined bottom cam face 39. These cam faces overlie with some clearance abutments individually related thereto and in the form of spring fingers 31 on a transverse bar 32 in the machine. These spring fingers 31 or abutments are each adjustable by a screw 33, the latter provided in a row on the bar 32. The bar 32 is of angular, stilf form and is a part of a pivoted bail structure which includes near each of two sidewalls 34 of the machine, an arm 35, the pivot rod 29 for the type action sub-levers 21 serving as a pivotal support also for the arms 35 and therefore the entire bail structure 32, 35.

The invention provides mechanism for adjustment of the bar 32 under mutually complemental control of several devices in the machine, but this mechanism will be explained later herein.

Referring now to Figure 5, the type bars 24 are pivotally supported in a usual manner on a segment 41 which is carried on a case-shift frame 41. This case-shift frame is shown in a lower-case position in Figure 5. It is guided at each lateral end by usual ball and raceway associations indicated at 42 and therebelow by a bail 43 having a member 45' extending transversely of the machine and having at each end of such member an arm 44. Studs 46 project laterally from said frame 41 into said arms 44. Pintles 47 fast upon the opposite sidewalls 34 of the machine, reach inwardly therefrom and support the bail 43 for rocking movement. The stud 46 on the left side of the machine reaches outwardly through a hole 48 in the sidewall 34 and is straddled therebeyond by two adjustable screws 511 provided on a rocker element 51. The latter is arranged for pivotal movement coaxially of the pintles 47 and therefore in unison with the bail. The said rocker element 51 is movable counterclockwise of Figure 5 to draw the case-shift frame 41 downwardly to an upper-case position, the upper-case types being then lined up for typing at the printing point 26. The hail 43 enforces equal movement of the case-shift frame at both ends. Converse movement of the rocker restores the case-shift frame 41 from upper-case to lowercase position. These opposite case-shift movements are effected under key control by a power device substantially as in the patent to Helmond, No. 2,275,759, dated March 10, 1942, the mechanism including an eccentric, not shown, adapted to operate a connecting rod 52 to impart reverse movements to the rocker 51 for effecting the case-shifts.

The machine also includes a usual ribbon vibrating universal bar 53 forming part of a bail generally designated by the numeral 54, see Figure 1. Downwardly reaching extensions of the sub-levers 21 actuate the universal bar upwardly at each typing operation. The said bail 54 has pivotal support in the opposite sidewalls 34 of the machine, as at 55, and beyond the right sidewall of the machine, has unitarily rockable therewith, an arm 56 having a roller 57. A spring 58 biases said arm 56 and hail 54 counterclockwise of Figure 1 to the normal position shown. At each operation of the bail 54, the roller 57 by camming action in a slot 62 of arm 60 displaces said arm downwardly about a pivot 61. From the rear end of the arm 60 there reaches upwardly a link 63 which, by a spring 59, is biased upwardly to the normal position seen in Figure 1. Having now more particular reference to Figure 2, such link at its upper end is associated with a bell crank 64 pivoted at 65. In turn, the bell crank 64, through a link 66, operates a ribbon vibrator 67 pivoted at 68. A ribbon 70 supported in said vibrator may have an upper black color field and a lower red color field, as indicated, or simply two tracks of use as represented by these fields.

In order that the upreaching link 63 may operate the vibrator 67 the required distance to present one or the other of said ribbon fields in front of the printing point, it is adapted by lateral positioning thereof to be coupled to either a pin 72 or a pin 73, the said link having at each side a notch for this purpose. So that the operation of the link 63 may present the upper color field'to the printing point, it is required to be coupled to the pin 72 of the bell crank 64 asin Figure 2. By coupling the link 63 to the pin 73, the link 63 will work on the bell crank 64 at smaller arms length and therefore will vibrate the ribbon to a higher point, namely it will present the lower color field at the printing point; The ribbonvibration to present either of said fields at the printing point occurs early in each typing stroke in view of the form of the slot 62 in the arm 60.

The machine includes a device seen in Figure 2 to move the universal bar actuatable link 63 selectively into coupled relation with either of the pins 72 or 73, thereby to condition the ribbon vibrating means for the desired extent of vibration. This device includes at the front of the machine a control wheel 74 fast on a short shaft 75 which is turnable in a hub 76 provided on the right sidewall 34 of the machine, see Figures 2 and 4. Secured to the right end of the shaft 75 is a wheel 77 having interspersed notches of three different depths in a repetitious pattern therearound. A roller 80 is carried on an arm 81 to bear against the notched wheel 77, said arm being pivotally provided on a stud 82 fast upon the adjacent sidewall 34. A primary slide 83 has a forked forward end in communication with a pivot pin for the roller 80. The said primary slide 33 and a secondary slide 84 are each provided with two fore and aft extending guide slots 85 whereby they are guided on two studs 36 that rigidly project from the right sidewall 34 of the machine. The secondary slide 84 has at its rear end a fork and pin connection at 87 with a bell crank 33 which swings horizontally on a pivot pin 1'11. A pin 91 on said bell crank reaches into a vertical slot 92 of the vertical link 63. The primary slide 83 has a pin 93 projecting into a slot 94 of the secondary slide 84, and a spring 95 arranged intermediate the two slides distends them normally to the limit of the pin 93 engaging the forward'end of the slot 94. A spring 96 associated with the primary slide 83 biases the same and the other slide 84 toward the front of the machine, the depth of entrance of the roll 80 into the different depth notches 33 of the wheel determining the position of the slide 83 and in turn the position of the bell crank 88.

In Figures 1 and 2 the control Wheel 74 exhibits in a .a nut 116 to clamp the stated parts together.

window 97 of the machine mask an index B, signifying that the black, upper ribbon field is selected. The stated position is one of three circumferentially evenly spread positions to which the wheel 74 may be turned to exhibit a fB in the window. In each of these positions one of three identical, maximum depth notches 98 in the wheel 77 is opposite the roller 80 and thereby determines its position as in Figures 1 and 2. The composite slide '83, 84 is distended to its full length established by the pin 93, with the roller 80 abutting in the notch 98 under the tension of the spring 96. Accordingly, the actuator link 63 for the ribbon vibrator is coupled with the pin 72'for the lesser ribbon vibration, as in Figure 2, for typing by the upper ribbon field. The control wheel 74 has also three evenly spaced indices R, and if it is turned to exhibit any of these in the window 97, the roller '80 will come to lie in one of three shallow notches of the wheel 77. The roller 80, through the composite slide 83, 84 and the bell crank 88, will then locate the link 63 so that it will be coupled to the pin 73 instead of the pin 72. Thus the machine is then conditioned for a greater-extent vibration of the ribbon, namely for typing by its lower or red color field. Interspersed with the deep and the shallow wheel notches 98, evenly spaced, are three other notches 98 which are of medium depth. Any of these notches are brought opposite the roller .80 by turning the control wheel 74 to an index S (stencil). The composite slide 83, 84 will accordingly locate the bell crank 88 so as to place the link 63 into a neutral position between the pins 72, 73 wherein its operation has no ribbon vibrating effect. It will be observed that the wheel 77 when showing anyone index B, R or .S, can be turned in one or the other direction to arrive directly at one of the other two index showing positions.

In turning the wheel 77 from position to position, the high point of the teeth which form the different depth notches 98 therebetween, pass the roller '80 displacing it beyond the extent required to effect coupling of the link 63 to the pin 72. However, the movement of the secondary slide 84 is limited by the left end of one of the slots 85 therein so that the bell crank 88 will move just far enough to couple the link 63 with the pin 73, the

' composite slide 83, 84, as the peaks of the teeth pass over the roller 80 (facilitated by the spring 95), being yieldingly shortened temporarily. Of course, the notchforming teeth in conjunction with the roller 80 serve in a detenting capacity.

It has been stated that the impression regulating bar 32 is adjustable under complemental control of several devices. These devices are (l) the described ribbon vibrating control mechanism including the control wheel 74, (2) the described case-shift means, and (3) a manipulative strength-of-inprint control mechanism yet to be described.

Drawing now more particularly attention to Figures 1, 3 and 4, the machine has fast on a transverse shaft 104, underneath each supporting arm 35 of the abutment bar 32, a helical cam 103. The shaft reaches oppositely through clearance holes 105 in the sidewalls 34 of the machine. Case-hardened plates 106 fastened by screws 107 to the outside of each sidewall 34, have short vertical guide slots 108. The shaft 104 has bushings 110 fast on opposite reduced end portions 112 thereof whereby it is guided for adjustment bodily up anddown in said slots 108. Both of the cams 103 are press fitted on the shaft 104. The bushing 110 on the right-hand reduced shaft portion 112 has coaxially thereof two other bushings 113 and 114. These bushings 113, 110 and 114 as well as a gear pinion 115 are axially stacked on the reduced shaft portion, the shaft having on a threaded end The bushings 110 and 114 at the right-hand plate 106 have circular flanges 117, 118, straddling the side faces of said plate the case-shift frame.

Additionally to the bushing the reduced left-end shaft portion 112 has a bushing 121. These bushings 112,

121 are axially clamped fast on the reduced shaft portion 112 by a screw 122. Each of the bushings 113 and 121 has directly adjacent to one of the bushings 112 a reduced portion to accommodate an annularly grooved roller 123.

The shaft 104 inclusive of the parts fast thereon is adapted to be raised and lowered bodily in the guide slots 108 under control of the case-shift mechanism. The mechanism for doing this will be described later herein. In any bodily adjusted position, said shaft moreover is adjustable rotatively. To this end a rack slide 124 is held in mesh with the pinion by a guide element 125. Such guide element has pivotal support on a reduced portion of the nut 1'16 and includes -a pair of fingers 126 slidingly fitting perforations provided in a horizontal flange of one of the sidewalls 34. Said guide element includes also an ear 127 forming therewith a guideway for the rack slide 124. It will be noted that the rack slide 124 stays appropriately connected with the gear pinion regardless of the position given to the shaft 104.

An impression regulating dial 128 is turnably accommodated, at the right of a keyboard portion of the machine, on a headed stud 130, the latter of which projects from the right sidewall 34 of the machine, rigidly secured thereto. This dial is preferably of a molded plastic material and includes a gear sector 131 in mesh with a forward portion of the rack slide 124. The rack slide 124 is kept in mesh with the gear sector 131 by a finger 132 which has a forked end for this purpose. The dial 128 comprises a cylindrical portion 133 having indicia 134 radially spaced thereon which in conjunction with a window 135 in the machine'mask identifies impression regulating adjustments given to the dial. For detenting the dial yieldably in various positions there is secured to the sidewall 34, by screws 136 and the stud 130, a plate 137 having radially spaced depressions 1=3'8.- For detenting action in said depressions 138, the dial carries a spring pressed plunger 140. Obviously the depressions 138 correspond with the several index positions of the dial.

The elevation of thecam shaft 104 is alterable by two interponents 142, one lying vertically between each roller 143 and the annularly grooved rollers 123 thereabove. The rollers 143 are turnably accommodated on studs 144 which rigidly extend from plates 145 secured to the sidewalls 34. Both the interponents 142 have a two-step face 146 and when the case-shift frame 41 is in the lower case position shown in Figures 1, 3, 4 and 5, the upper step of each face 146 underlies the roller 123 in its groove. Each of the interponents 142 has pivotal connection with a bell crank 147 which is associated for rocking movement conjointly with the guide bail 43 for Specifically, each of the bell cranks is carried on one end of the bail 43 coaxially of the pintles 47 and is secured fast to the bail by one of the studs 46. When the case-shift frame 41 is actuated downwardly to upper case position, the bell cranks 147 swing forwardly moving the interponents 142 so that then the lower steps of the faces 146 support the rollers 123, wherefore the shaft 104 assumes, consequently, a lower elevation to the end of conditioning the machine to yield stronger typing impulses.

There is interposed between each of the cams 103 and an arm 35 of the impression regulating bail, an interponent 150. These interponents have each a thick and a thin portion as shown. The thick portion is in interposed, active position in the B (black) as well as the- S" (stencil) position of the ribbon vibrating control 74. The thin portions of the interponents 150 move into controlling positions when thecontrol 74 is turned to any R (red) position. Said two interponents 150 are carried for conjoint movement on arms 149 of a bail 151 which includes a rod 152 extending intermediate of the two sidewalls 34 and is pivoted by studs 153 carried fast in the sidewalls 34. For exercising the stated con-.

trol, the wheel shaft 75 has two cam elements 154, 155 fast thereon which have high and low ranges so organized therearound to swing and hold a rocker 156 back and forth on a frame-supported pivot stud 157, respectively incidental to setting the ribbon vibrator control 74 to R and B. For being so controlled, said rocker 156 has one follower roller 158 contacting the rear of the cam 154 and one substantially diametrically thereacross contacting the front side of the cam 155. The rocker has an upwardly and rearwardly reaching extension 160 which by a link 161 is connected to an arm 162 which is unitary with the bail 151.

The abutment bar 32, under the constant influence of springs 163 acting on its supporting arms 35, always compacts the spiral cams and their related interponents 142, 150 solidly upon the frame supported rollers 143. The power strokes of the actuators 13 are lengthened by lowering the bar 32 and conversely are shortened by raising it. In Figures 1 and 7, the strength-of-imprint control dial 128 is in an extra light imprint controlling position, wherefore the high portions of the spiral cams underlie the interponents 150, causing earlier divorcement of the actuators 13. Adjustment of the dial 128 progressively to the other positions, rearwardly, will lower the abutment bar.

The stated spiral cams 103 and the interponents 142 and 150 are solidly compacted upon each of the rollers 143 for any state of adjustment along a substantially straight line. Furthermore, these lines lie substantially in the direction of reaction exerted by the abutment bar 32 when the abutments thereon are struck. This is" highly important because the grip of the snatch pawls' in'the power shaft resists divorcement so strongly that the shock 'on the bar 32 tending to displace it and distort the supporting structure is quite strong. Since the abutment bar 32 is solidly supported in any compounded adjustment given thereto, it carries out its actuator-disengaging function without detrimental yielding, that is with utmost precision in accord with its adjusted position. Therefore, the presence of a greater ora smalleramount of friction or lubricant at'the'place of engagement "of the actuator with the abutment 30 or at the place of contact between the snatch pawl 14 and the power'r o'll'12, causing variations of shock on the bar 32, does not cause fluctuations in the power operating impulses. Moreover, the adjustments given to the spiraljcam s' 103, the

interponents 142 and the interponents 150, complement each other universally and reliably under all conditions so that for any strength-of-irnprint adjustment of the dial 128 the type impressions will be of uniform texture or strength.

The interponents 142, 150, which actually constitute cams, need not necessarily have two stepped faces. In such case they may be simply fingers of a certainthickness which when regulated to cause heavier impressions, may move completely clear from between their correlated parts. i

Other structures of entirely difierent forms may beresorted to within the scope and purposes of the invention, and portions of improvements may be used without others.

What is claimed is:

1. In a typewriting machine, the combination with a seriesof laterally adjacent type actions having actuators which are selectively associable with a common power member for reception of power impulses, of vibrator means normally holding a typewriter ribbon removed from a printing point, means operable by the type actions to operate said vibrator means, adjustable means universal to said type actions to predetermine therefor varying power impulses and in serving to vary such power impulses being subjected to a strong force in a certain direction, a rotatable-cam near each of the opposite ends of said adjustable means, two interponents'near each of the ends of said adjustable means having correlation with the cam thereat to adjust said universal means and firmly support it in the said direction, a shaft connecting the two cams for conjoint rotative adjustment, means to regulate the operation of the ribbon vibrator means for varied throw of the ribbon, means operable by said regulating means to adjust conjointly at each of the opposite ends of said adjustable means one of said interponents, case-shift means, means controlled by said case-shift means to adjust the two other interponents conjointly to different positions, and manually settable strength-of-imprint control means to rotate said shaft, said cam and interponents at both ends of the adjustable means having mutually complementing adjustment eifects on the adjustable means. i

2. In a typewriting machine in combination with a toothed power drive roll and a series of type actions having actuators which are selectively movable into toothed engagement with said power driven roll for reception of type-action operating impulses, of ribbon vibrator means normally holding a typewriter ribbon removed from a printing point, type-action operated means to operate said vibrator means, means comprising a transverse bar in the machine, engageable by said actuators to etfect divorcement thereof from said power driven roll, said'actuators at each said engagement exerting a violent force on said bar in a certain direction, settable strength-of-imprint control means, means manipulative to diiferent positions to predetermine different extents of operations of said vibrator means, case-shift means and means under complemental control of said last three introduced means to adjust said bar, comprising near each opposite end of said bar, a cam element, and ,two interponent elements related to each of the cam elements and movable for supplementing their adjustment, said cam elements adjustable conjointly by said control means, one interponent element at both opposite ends of the bar movable conjointly under control of said case-shift means, and another interponent element at both opposite ends of the bar movable conjointly under control of said manipulative means.

3. In a typewriting machine, the combination with a series of type actions having actuators which are operatively associable selectively with a common power member for reception of power impulses, of vibrator means normally holding a typewriter ribbon removed from a printing point, means operable by the type actions to operate said vibrator means, means to regulate said vibrator means for varied throw of the ribbon, case-shift means, a manually settable strength-of-imprint control, a bar adjustably associated with said type actions to predetermine therefor varying power impulses and in serving to vary such power impulses being subjected to a strong force in a certain direction, a frame-supported roller at each end of the bar spaced therefrom in the said direction, means arranged intermediate said bar and said rollers to afiord in conjunction with the latter an adjustable support for said bar and comprising between the bar and each of the rollers a series of superimposed adjustable elements, each of the elements at one bar end having a related element at the other bar end and there being at least three pairs of such related elements, and means to adjust different pairs of said elements respectively by said ribbon vibration regulating means, said case-shift means and said settable strength-of-imprint control means.

4. In a typewriting machine having a frame, the combination with a series of laterally adjacent type actions having actuators which are selectively associable with a common power member for reception of power operating impulses, of vibrator means normally holding a typewriter ribbon removed from a printing point, means operable by said type actions to operate said vibrator means,

means universal to said type actions, substantially coextensive with the width of the machine and adjustable transversely to the said width to predetermine varying power impulses for said type actions, means to regulate the operations of said vibrator means for varied throw of the ribbon, case-shift means, manually settable strengthof-imprint control means, and means to effect complementary adjustments of said universal means by said last three means, comprising, a cam near each opposite end of said universal means, a shaft having said cams mounted thereon for rotative adjustment thereby, means at laterally spaced locations in the machine to mount said shaft on the frame for bodily adjustments transversely of its length and turnably, means associated with said shaft near its opposite ends to adjust it bodily, adjustable means interposed between said cams and said universal means, means to control adjustably said associated means and said adjustable means, one by the said regulating means and the other by said case-shift means, and means to rotate said shaft adjustably by said manually settable strength-of-imprint control.

5. In a typewriting machine having a frame, the combination with a series of laterally adjacent type actions having actuators which are selectively associable with a common power member for reception of power operating impulses, means universal to said type actions, substantially coextensive with the width of the machine and adjustable transversely to said width to predetermine varying power impulses for said type actions, a cam near each opposite end of said universal means, a shaft having said cams mounted thereon for rotative adjustment thereby, means at laterally spaced locations in the machine to mount said shaft on the frame for bodily adjustments transversely of its length and turnably, adjustable means interposed between said spiral cams and said universal 10 means, a manually settable strength-of-imprint control in the region of the keyboard of the machine, and means to turn said shaft by said control regardless of its transversely adjusted position.

6. In a typewriting machine the combination with a series of type actions having actuators which are selectively associable with a common power member for reception of type-action operating impulses, of vibrator means normally holding a typewriter ribbon removed from the printing point, type-action operated means to operate said vibrator means, means engageable by said actuators to efiect divorcements of the latter from the power member, the said actuators while being divorced exerting on the said engageable means a force generally in a certain direction, means to support said engageable means solidly and adjustably in the said direction for variably and accurately controlling said actuator divorcement from said power member, said supporting means comprising three complementary adjusting means arranged superimposed substantially in said direction to afford adjustable, solid support to said engageable means in the said direction, means to regulate the extent of operation of said vibrator means, manually settable strength-of-imprint control means, case-shift means and means to adjust each one of the three complementary adjustable means by one of the last three introduced means in a complementary manner to the other two complementary adjustable means.

Dorsey Aug. 11, 1931 Letterman Aug. 7, 1956

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