US1969274A - Typewriting machine - Google Patents

Description

Aug. 7, 1934. A. NEMCOVSKY TYPEWRITING MACHINE 4 Sheets-Sheet 1 Filed April 25, 1 929 Aug.'-7, 1934. 1.. A. NEMCOVSKY TYPEWRITING MACHINE Filed April 23, 1929 4 Sheets-Sheet 2 INVENTOR 14v ATTORNEYS 1934. A. NEMCOVSKY I 1,969,274

TYPEWRITING MACHINE Filed April 25, 1929 4 Sheets-Sheet "a 7 HI] [mu [m a INVENTOR .Doms' A. Mmcavs/ily BY 491W QMOWM ATTORNEYS Aug. 7, 1934. A. NEMCOVSKY 1,969,274

TYPEWRIT ING MACHINE Filed April 23, 1929 I 4Sheets-Sfieet 4 l NVENTOR JLL/ ATTORNEYS Patented Aug. 7, 1934 PATENT OFFICE 1,969,274 mnwm'rme MACHINE Louis A. Nemcovsky, New York, N. Y; assignor to Peerless Typewriter Corporation, a. corporation of New York Application April 23, 1929, Serial No. 357,388

4 Claims. (Cl. 197-25 My present invention is concerned with the provision of a typewriting machine which will be substantially silent in operation.

An object of the invention is to provide a 5 substantially noiseless typewriter of the modern front strike type bar variety which includes a standard key-board and which will be rapid in action, conventional in touch and capable of distinctly printing a large number of carbon copies with no special effort on the part of the operator.

More specifically an object is to provide a noiseless, rapid machine in which the depression of any key of the keyboard-is operative to cause the type of its associated type bar to be moved firmly and positively, quickly and silently against the platen in a direction substantially at right angles to the platen axis.

Such action represents a material improvement over the conventional so-called noiseless key actions in which many of the type members strike the platen at, an acute anglewith a resulting tendency to slide on the platen and to produce blurred and pale carbon copies.

Another object is to provide a noiseless machine devoid of complex lever trains whereby inaccuracies in type alinement due to the wear on the manifold pivots of a complex lever train are avoided.

Another object is'to provide a system of lever trains in which the possibility of bending or distorting any of the levers is reduced to a minimum even after a long period of use and even though the keys aredepressed with unnecessary force or unusual rapidity.

' Another object is to provide a typewriter of the class described in which the printing action is positively effected by key controlled means, and no energy-storing devices or other non- 40 positively acting means for forcing the type against the platen are utilized.

Another object is to provide a typewriter in which the initial adjustments at the time of the assembly operation are few and may be ex:

peditiously made, and a machine which may be quickly and conveniently readjusted at any time by a repair man.

Another object is to provide a machine which not only retains the standard keyboard but in which the instrumentalities necessary for efiecting noiseless operation are mounted on the body without increasing the size of the machine, detracting from its appearance or rendering it awkward and cumbersome to transport, manipulate, inspect or repair.

In accordance with a preferred embodiment of the invention, the machine is of the front strike type including a standard keyboard and a conventional roller platen. The usual series of pivoted key levers moving in parallel planes are employed. The type bars aredisposed in the usual basket frame when at rest, and operative connections are provided between the key levers and type bars for moving the type bars in non-parallel planes.

Preferably upon the depression of any key its associated type bar is moved to a point where the type which it carries is disposed closely adjacent the platen. and this type is subsequently positively pushed against the platen upon the continued depression of the key lever. Whipping or hammering of the type against the platen as well as' the non-positive final movement of the type by energy storing devices is avoided. 7

Preferably the head of each type bar mounts a type carrying member which is movable relatively to the type bar which carries it. Such type bearing members may assumemany forms and may travel in many paths in their final printing movement against the platen, but in any event are so designed that the type is moved positively against the platen in a direction at right anglesto the platen axis.

In accordance with the preferred and illustrated embodiment of the invention each type bearing member is in the form of a plunger guided for axial movement in the type bar head v and normally spring held in retracted position. The connections between the key levers and type bars are such that upon depression of a key the selected type bar is shifted to a position where its head is arranged closely adjacent the platen and the type carrying. plunger carried by the head is disposed at right angles to the platen axis. Upon further depression of the key, after the selected type bar has reached such position, a pusher engages the type. bearing plunger and moves the.same against action of its retracting spring into printing engagement 0 with the paper on the platen. I This pusher-actuated movement of the type carrying plunger is totally distinct from the wiping action or the hammer actionemployed with the conventional typewriting machine. in the nature of a positive and continuous thrust from its normally inactive position to its printing position. The plunger movement while a relatively rapid one, is not in the nature of a hammer blow nor is it dependent in any sense The plunger movement is upon the overthrowing or wiping action of either selected type bar head in accordance with the a type bar or a type bar actuating device. In fact, with the present construction the type bar merely serves as a carrier to bring the movable type-bearing element into proper position where it registers with the pusher. Thus, the effectiveness of the printing operation is in no way dependent upon or affected by the angles which the type bars themselves define with the platen axis, either when the type bars are at rest or when they have moved to a selected operative position. No matter which type bar is selected, the type plunger which it carries will always be positioned at right angles to the platen axis and the plunger means which preferably acts upon the plungers of any selected type bar will always move the type firmly against the platen to produce a strong, clean, rapid impression, particularly efiective where large numbers of carbon copies are to be made, due to the fact that no relative sliding of the type and platen surface is present. All of the carbon copies will be clean and distinct.

Preferably each type bar head carries two parallel plungers, lower case type being borne by the end of one plunger and upper case type by the end of the other plunger. A feature of the invention is the novel path of travel of the plunger-carrying type bar heads, the latter portion of this path being rectilinear for all angularities of the type bars and the selection of upper or lower case type being determined by the length ofthis final rectilinear travel of the typebar head.

Preferably each type bar is both pivotally and slidably mounted on its pivot and the operative connections between the key levers and type bars are such that the initial movement of the type bar carries the type bar head in an arcuate path-while the final movement of the type bar carries the head in a rectilinear path which is preferably vertical and parallel with the vertical plane of the longitudinal axis of the platen roller.

-A very simple stop mechanism is utilized for determining the total effective throw of the type bar and consequently determining the selection of the 'lower case and upper case type which it carries. Such stop mechanism ,is preferably in the nature of a key-selected stop device limiting the throw of one member of the sub-lever train which provides the operative connection between the key levers and type bars.

Preferably a single pusher member is employed, this pusher member acting upon any type plunger which may be alined therewith by the depression of a selected key and acting either upon the'upper or lower plunger of the position of the stop controlling key or capital shift-key of "the keyboard.

The means for actuating the pusher includes a lever train, connected to a power transmitting preferably in the nature of toggle joints or simimemberwhich preferably extends the full width of the machine and has operative connections with all of the key bars, such connections being lar noise eliminating .mechanism.

Such toggles additionally provide lost motion connections between the key levers and. the

' power transmitting element of the pusher-ac,

tuating lever train. The effect of this lost motion connection is to permitthe first portion of the key dip to be accomplished without trans- .mitting motion .to the pusher. intact, the lost 'inmotion, so that the selected type bar having reached its operative position during the initial portion of the key dip will retain this position until the'pusher has been actuated to slide the selected type plunger against the platen.

Preferablythe sub-lever train which connects each key lever to its type bar consists of only two levers which levers both operate on stationary fulcrums and are connected to each other by a movable fulcrum. Thus the repair of such lever train may be expeditiously effected, and there are but a few bearings at which wear may occur. In a similar manner the lever train for actuating the pusher is of simple construction, embodies few parts and may be readily repaired. It will be remembered, of course, that there is only one lever train for operating the common pusher, which in itself materially simplifies the construction.

All of the moving parts of the machine are so guided and so laterally braced that there is practically no danger of bending or twisting any of the levers, even though the keys be depressed with undue force and rapidity.

The particular type bar motion which. in-' volves moving the type bar head in a rectilinear 110 path at the end of its stroke permits thepusher to be moved through only a short distance in order to effect a printing operation, whereas the swinging of the type bar head in an arcuate path would necessitate a very long pusher movement due to the fact that the pusher would have to be placed well away from the platen to provide clearance for the swinging of the type bar head.

With the above noted and other objects in view. the invention consists in certain novel features of construction and combinations and arrangements of parts as will be more fully hereinafter described and pointed out in the claims.

The invention may be more fully understoodfrom the following description in connection with the accompanying drawings, wherein:

Fig. 1 is a transverse sectional view somewhat diagrammatic, through a typewriter machine 130 embodying the present invention. showing the normal position of the parts when at rest.

Fig. 2 is a view similar to Fig. 1, but showing the position of the parts when a selected key has 'been. fully depressed, the selected type 135 bar swung to'operative'position and the pusher has completed its printing stroke.

Fig. 3 is a view in longitudinal section through the machine taken approximately on the line Lf 33 of Fig. 1.

Fig. 4 is a transverse sectional detail taken approximately on the line 44 of Fig. 3-and showing the manner in which the capital shift key controls the position of the lever train stop;

Fig. 5 is a vertical sectional detail taken ap- 145 proximately on the line 5-5 of Fig. 4, and

Fig. 6 isa horizontal sectional detail on the line 6-6 of Fig. 5.

In the drawings, 1 have shown a frame including a back plate 10, side plates 11 and a relatively low front plate 12 from which rises a casing member 13, adapted to conceal the actuating lever train of the pusher. In accordance with conventional practice-the machine is preferably mounted upon cushioning feet 14 and is provided with the usual slidable and rotatable roller platen 15, the handles of which are shown at 16. The particular manner of rotatably and slidably mounting this platen, and the mechanism for imparting step-by-step rotary and sliding movements to it are not in themselves my invention. Consequently it will be understood that insofar as the present disclosure is concerned any conventional platen mounting and associated mechanism may be employed.

A standard four-bank keyboard is employed in combination with the usual spacer key 17.

The keys of this keyboard-are illustrated at 18 and the associated key levers include substantially horizontal portions 19 provided with offset vertical ends 20 upon which the keys are mounted. To further simplify the construction in'Figs. 1 and 2 I have shown the key action of only one key of the upper bank.

Preferably a cross-frame member 21 disposed closely adjacent the rear frame plate 10 extends the full width of the machine and is provided with a series of upstanding cars 22 between which the rear ends of the key levers 19 are pivoted, as at 23. Preferably also coiled expansion springs 24 pocketed in the frame member 21 exert an upward pressure on the key levers near their pivoted ends and act to retain all of the keys in the normal elevated position shown in Fig. 1.

A segmental casting 25 preferably secured as by screws 26 to a transverse frame bar 27 serves to anchor and support the type bars 28 as well as to guide the movement of these type bars to operative position and to firmly sustain the type bars against transverse bending strains when in operative position.

Segment 25 at its lower forward edge is provided with a relatively deep forward arcuate extension 29 having a series of slots 30 therein, such slots being radial relatively to the center of which the segment and are are struck and serving to accommodate the guide and laterally brace the offset ends 31 of the type bars 28. Preferably such ends are provided with arcuate slots 32 receiving roller pivots 33 which span slots 30 whereby the offset type bar ends have a compound pivotal and slidable connection with the pivots 33.

The type bar heads 34 are preferably of considerably greater width than the shanks of the type bars and maybe in the nature of skeleton frames in which a pair of plunger members or type carriers 35 and 36 are mounted for axial sliding movement in a direction'substantially at right angles to the longitudinal axis of the type bar shank. Preferably the skeleton which constitutes the type-bar head includes the spaced frame bars 37 and 38- defining spaced bearings for the plungers.

Crosspins or equivalent stop members 38a extend transversely of the plungers between the frame bars 37-38 and coiled expansion springs 39 encircling the plungers and confined between the frame bar 37 and the pins 38a tend to oppose movement of the plungers in a printing direction and to rapidly restore them to the position of Fig. 1 when their projecting rear ends have been released by the pusher.

Each plunger carries a type character 40 'on one end and has its other end suitably shaped for engagement by the pusher member whichwill' be later described.

An arcuate guiding and bracing plate 41 fixed I to the upper forward face of the segmental casting 25, as by a screw 42, is provided with a forwardly projecting flanged portion 43 The operative connections between the key levers and type bars include sub-lever trains composed of two sub-levers 46 and 47. Sublevers 46 are bell-cranks, the intermediate portions of whichare fulcrumed on a long cross pivot pin 46a extending across notches 48 of a transverse frame bar 49. The second sub-lever 47 is of general L-shape, the shorter vertical leg of this lever being fulcrumed on a pin 50 within a slot 51 in the under face of a segmental frame member 52. The opposite. end of the lever 47 is .pivotally connected as at 53 to-the type bar adjacent the point where the shank of a type bar 28 joins the offset 54 which con nects it to the offset end 31. One end of the bellcrank 46 is provided with a cam slot of angular formation including a straight end 55 opening sub-lever 46 by a slot and. pin connection, which may conveniently include a stud 57 on lever 46 working in a keyhole slot 58 in the lever 47.

The tail-piece 59 on the sub-lever 47 includes a shoulder 60 adapted to engage a padded stationary stop 61 on the frame 52 and includes also a pair of stepped shoulders62, 63, either of which may be selectively caused to engage a fixed stop 64 adjustable in the flange 65' of the arcuate adjustable stop bracket 66. Movement of the lever 47 in a clockwise direction is limited by the engagement of shoulder 62 or 63, as the case may be, with the stop member 64, while movement of this lever in a counterclockwise direction is limited by the engagement of shoulder 60 with the stop 61. It may be noted here that the stop 64, for purposes of convenient adjustment may simply comprise a screw 67,

adjustable through the flange 66 and locked in the proper key 18 is depressed. Upon depresj,

58 of the two sub-levers.

' 'head is caused to move through the compound path designated by the line a. in Fig. 1. It will be noted that the'first portion of this path is arcuate and the latter portion in a substantially rectilinear vertical direction. This rectilinear movement occurs after the pivot 53 has been swung into a straight line between the pivots and 33. It is caused by the fact that the cam slot 32 is struck on a radius equal to the distance between the fulcrum 50 and the.

pivot 53, so that the arcuate travel of the pivot 53 is compensated for by the similar arc of the cam slot 32.

By the time that the type bar has reached the vertical position of Fig. 2 the stud 56a will have reached the end of the slot section 56 and will be travelling in the slot section 55, thereby establishing the lost motion connection between the key lever 19 and the sub-lever 46 and permitting further depression of the key 18 without disturbing the position of the previously set type bar or the positions of the levers 46 and 47.

The portion of the key dip which occurs after the setting of the type bar and during the time that the stud 56a is riding down the slot 55, is the portion of the key bar stroke which actuates the pusher mechanism, to slide the selected plunger 35 or 36 as the case may be into printing engagement with the platen.

The pusher includes a substantially inverted U-shaped rocking frame, the depending leg portions vof which are pivotally secured as at 71 to the opposite side frame plates 11 of the machine. Rigidly connected with the upper ends of these arms is a cross-bar 72, the intermediate portion of which is formed with a conical rearwardly facing extension 73. Such extension is preferably bored for the reception of an adjusting screw 74 which backs and sets a tapered cushioning plug 75, which in the present instance constitutes the pusher proper.

The actuating mechanism for rocking this pusher from the position of Fig. l to the printing plunger-actuating position of Fig. 2 includes a transverse plate 76 extending across the front portion of the machine and rockably mounted at its ends on conical studs 77 carried by screws 78 which are adjustable in and out through the frame plates 11 and through castings 79 mounted at the inner faces of the frame plates. The centering conical bearings 77 are alined with the axis of rotation of the flat rocker plate 76, which axis is substantially adjacent the forward edge of the plate. Adjacent the rear edge of the plate a longitudinal pivot shaft 80 passes therethrough, the rocker plate having a series of notches therein at 81, to expose the pivot shaft and permit connection of this shaftwith all of the various key levers l9.'

The operative connections between'the key levers l9 and the shaft 80 consist of pairs of toggle links 81 and 82. Link 82 is pivotally.

connected as at 83 to the key bar 19, link 81 is pivotally connected to the shaft 80 and the two links are pivotally connected together at 84. These toggle links constitute lost motion c'onnectionswhich permit the keys to be initially depressed to points where the type bars are '75 moved to operative position and subsequently serve-as positive connections for rocking the plate 76 rearwardly about its pivots 77. In additoggle links 81' and 82 assure silent operation,

since the straightening of these toggles as the key levers pick up the plate 76 is necessarily a substantially noiseless operation.

A coiled contractile spring 85 anchored as at 86 to the forward wall of the casing 13 and at its other end to a lug 87 on the plate 76 tends to maintain the plate 76 in the position of Fig. 1 and the tension of this spring must be overcome in order to rock the plate after the toggles have been straightened out and during the latter portion of the key dip.

Fixedly secured as by screws 88 to the upper face of the plate 76 is one end of a crank arm 89, normally lying closely adjacent the front wall of the casing 13. The free end of this crank arm is connected by a short link 90 to the free end of a lever 91 which is fixed to a transverse shaft 92 extending across the rear upper portion of the casing 13. Also fixed to this shaft is a depending crank arm 93 preferably mounting an anti-friction roller 94 at its free end, which roller is maintained in operative engagement with the cross-bar 72 by a light coiled contractile spring 95 connecting the crank arm and cross-bar.

It will thus be seen that as the free end of lever 91 is drawn down by the link 90 upon rocking of the plate 76, crank arm 93 will be moved around the shaft 92in a clockwise direction and its roller 94 will exert a camming action on the crossbar 72 to rock the pusher frame from the position of Fig. 1 to the position of Fig. 2. In the course of such'rocking movement the pusher plug 75 engages the rear end of the pre-selected plunger 35 or 36, as the case may be, and positively moves it axially into printing engagement with the platen.

The stop mechanism, controlled by the capital shift-key, 95, shown best in Fig. 4, includes as above noted the arcuate stop bracket 66 with its adjustable stop member 64. The ends of this bracket carry castings 96 of general V- shape in horizontal cross-section (Fig. 6). V-shaped notches 97 in the end faces of the casting 96 cooperate with similar notches 98 in rails 99 fixed by screws 100 to the side frame plates 11 to accommodate ball bearings 101. These bearings provide an anti-friction mounting for the forward and rearward shifting of the carriage 96 under the influence of the capital shift-key.

The means for effecting such shifting preferably includes a key lever 102 to which the shiftkey 95 is fixed. Lever 102 isconnected by a substantially vertical link 103 with the intermediate portion of. a link 104 pivoted at 105 to the side frame plate ll. The other end of the link 104 is pivoted at 106 to a toggle link 107, which is one of a toggle link pair 107 and 108. Toggle link 108 has a fixed pivot at 109 on the frame plate 11 and the movable pivot between the toggle links is shown at 110. I

The intermediate portion of the link 103 is provided with a cam slot accommodating a roller 111 on the bracket 96, this slot being operative to shift the stop carriage or frame backwardly and forwardly.

With this end in view the cam slot includes an meagre Upon depression of the capital shift key 95 lever 102 acts to draw the link 103 downwardly, noiselessly breaking'the toggle links 107 and 108 and causing the roller 111 to be moved forwardly by the action of the inclined slot portion 114. This roller at the end of the capital shift key stroke being in the upper portion 112 of the cam slot and the stop carriage having been shifted forwardly the stop screws 64 are set for action with the shoulder 63 instead of with the shoulder 62, whereby the type bar head will have a longer rectilinearstroke and will bring the upper case type plunger 36 instead of the lower case type plunger 35 into position for actuation by the pusher 75. It is believed that the operation of the machine will be fully apparent from the foregoingdescription for all ordinary purposes. As is customary the capital shift key is always depressed when capital letters are to be printed prior to striking the particular printing key for the letter.- Depression of the capital shift key in this case serves to slightly retract the stop frame and set the stop 64 for coaction with the shoulder 63.

As the printing key is depressed the sequence of operations is as above described, the type head being first swung in an arcuate path and then moved directly upwardly in a rectilinear path by its actuating sub-lever train. The length of this rectilinear path is determined as aforesaid by the particular position of the stop carriage and this carriage insures alinement 'of either the upper case or lower case plungers 36 or 35 with the pusher. The above noted operations are accomplished on the initial operation of the printing key dip, lost motion toggle links 81' and 82 preventing actuation of the pusher lever train during this time. As soon as the printing plunger is moved to printing position, the lost motion connections of the sub-lever train come into operation so that the plunger is merely held in position while the pusher lever train operatesto urge the pusher against it and force it swiftly, firmly and silently against the platen.

Upon release of the printing key spring 24 restores thekey lever train while spring 85 restores the pusher lever train.

It will be evident that the type action described above not only eliminates the use of energy storing devices, but avoids movement of any printing plunger against the platen at other than a right angle. Thus sliding of the type on the platen is obviated, clean sharp carbons are produced and the undesirably noisy whipping,

action of conventional typewriting machines is avoided.

1 silent toggle links or other lost motion connections between the various-partaof the machine; further by the use of padded stops whenever abutment of one part against another is neces -sary; and fourthly by a lever train arrangement.

involving few pivots where wear is apt to occur and substantially self-sustaining against lateral vibration or hum while the machine is being.

operated.

The final stray sliding motion of the type plungers carries them but a short distance be-,

fore they reach the platen, and even though the printing keys be depressed with great rapidity the cam actuation of the pusher prevents these plungers from being hurled or smartly struck against the platen and insures that they are latter portion of which is.rectilinear, a pair of type members mounted inthe head of each type bar, stop means selectively controlling the total throw of the type bar whereby either type member may be registered with the platen, said type members being axially movable in the type bar head, and a pusher to axially shift the selected pushed rapidly and firmly but without sudden 'path, the first portion of which is arcuate and I member into printing contact with the platen.

2. In a typewriter including a platen, a key action including key levers, and type bar's, means connecting the key levers and type barsoperative to move the heads of the type bars to a position adjacent the platen through a path, the latter portion of which is rectilinear and the earlier portion of which is arcuate, a pair of type members mountedin the head ofqeach type bar, and stop means selectively controlling the total throw of the type bar whereby either type member maybe registered with the platen, the stop means including a shiftable stop member cooperating with said connecting means.

3. In a typewriter including a platen, a key action including key levers, and type bars, connections between the key levers and type bars operative to'move the heads of the type bars to -substantially right angles to the axis of the platen.

4. In a typewriter including a platen, a key action including key levers, and type bars, con- 'nections between the key levers and type bars operative to move the heads of the type bars to a position adjacent the platen through a path, the latter portion of which is rectilinear, and the earlier portion of which is arcuate, a pair of type members mounted in the head of each type bar,

stop means selectively controlling the totalthrow of the type bar whereby either type member may be registered with the platen, the stop means including a shiftable stop member lini= .-iting the throw of the key lever and type bar connections, and a'shift key controlling the po-.

member.

LOUIS A. NEMCOVSKY.

sition of the stop

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