US1988913A - Typewriter - Google Patents

Description

Jan.. 22, m5. G, Moneum, Lassla TYPEWRITER Filed Sept. 30, 1931 fnl/enfer:

@NWWQA Patented Jan. 22, 1935 l y l UNITED STATES PATENT OFFICE TYPEWBITER Gino vModigliani; Ivrea, Italy, assigner to rm: Ing. C. Olivetti & C., Ivrea, Italy Application September 30, 1931, Serial No, 566,104 l In Italy June 25, 1931 1 Claim. (Cl. 197-30) This invention relates to typewriters in which levers 2 all move in parallel planes, at right angles the characters are typed on the paper rolled over to the axis of the cylinder on which the paper is a cylinder by means of levers moved by the preslaid. sure exerted on the keys of the key-board by the A spring 5 maintains lever 2 in its rest posi- 5 ngers of the typist, with interposition of an tion, whilst two vstops 6 and 'I limit its stroke 5 inked ribbon; brought about by the nger's action. The end 8 -Its object is a new arrangement of levers obof lever 2 operates a bell-crank lever 9, pivotally taining a visible print, in which the types are carmounted on a steel wire 10, carried by a' plate 11, ried at the end of levers, pivotally mounted and provided also with notches in which are lodged oscillating as in most typewriters, around a pin: levers 9 and consequently similar in arrangement 10 but in which instead of impressing a great speed to plate 4. to the type-bar-lever so that the type strikes the Each lever 9 lies and moves in the plane of the paper with force acting inthe Way of a minute corresponding lever 2, and the motion is transhammer, said type-bar-lever, after having covmitted between the two levers with 'variable 16 ered apart of its swing, from the position of rest, ratios, because at the beginning of the motion 15 at a high velocity, slowsv down rapidly towards the key-lever operates the extremity of the arm the end of said swing, coming in contact with the of the bell-crank lever, whilst at the end the pointy paper at a very limited speed and consequently of contact between the two levers moves on very without a blow, obtaining subsequentlythe imnear to pin 10 of lever 9. Y 20 'pression by pressing stronglythe types upon the 'I'hus the inertia of the system is gradually 20 paper. In such a way percussion is replaced -by overcome by a very slight effort of the typist, inpressure, avoiding the noise of the blow of the creasing then gradually the angular velocity of type against the cylinder on which the paper is lever 9. i wound and thus securing a silent operation of` By means of a pull-rod formed by two memthe typewriter. bers 12 and 13 connected by a threaded part in 25 The accompanying drawing refers to a typeorder to adjust its length, the motion of lever'9 writer with standard key board in Which each is transmitted to a lever 16 swinging about pin 17 typebar-lever Carries two different Signs; 0f and carried by a plate 38, provided as usual with course the invention may be applied to typeslots for lodging the levers. The pull-rod 12-13` writers in which each of said levers carries either is pivoted in 14 on lever 9 and in 15 on lever 16; 30

a Single Sigh 01` more than WO- 30th the dl'aW- as will be explained hereafter it is convenient to ing and the specication are limited'exclusively design the pins of said pivots spherical. so as to to the parts and members concerning the present allow the pun-rod to incline somewhat on the invention, leaving out al1 the other parts of the p1ane of the levers. Lever 1s carries a nxed pin typewriter, so that in Figure 1, showing a Side 35 which can move al slot 18 cut in a lever 19 35 view of the typewriter in its position of rest and swinging around pin 20. Pin 20 is carried by an in Figure 2 showing the same in the position of angle plate 21 swinging in its turn around pin 22, work, is only represented the set of levers transcarried by plate 23 and Subjeei; to be adjusted mittng the motim from the key on which the by means of two screws 24 and 25 which can allow *I 40 finger of the typist presses, to the type-bar-lever. to said plate 23 slight displacements, ming it 40.

In said system of levers an important feature i is the fact that each lever of the system describes dgtglglgl slgsehleof a plane motion and that all forces applied to said Th f d f 1 r- 19 o erates b means of lever act in the plane of motion. Thus there are, e ree en o eve p th ya l vl with regard tothe levers, no cross-stresses which pm 26 a link 27 hmged at lts o er enTil; i' pm 45 would cause friction in the pins, making the op'- 28 cafed by the type'bar'lever 29' efer eration of the' typewriter less even and quick. 29 SYVmgS arouxld Pin 3 formed by a' steel Wnje On examination of the drawing it may be seen camedby a ellelllar plate 31, whose centrens that key 1 on which the finger of the typist located, aS usually done in typewriters Wlth Iad 18l strikes, is carried by a lever 2 pivotally mounted arrangement 0f levers, in DIOXm-ty t0 the 130ml? 50 on a steel wire 3 carried by a plate 4, extending in Which the type-S Strke- LeVel 29 Carries 0n for the whole front length of the typewriter and its free end the types 32 and in its rest-position, provided with notches at equal distances, in rests on a cushion 33 in felt or in any other propwhich are lodged the various levers of the keys. er material. Said wire hinge 3 is arranged horizontally, so that The paper ,on which the typing is done is rolled 65 lows that to avoid oblique stresses, every pull as usual on a cylinder 34 against which the type 32 is brought to press.

As stated, as the type-bars all have to impress the type at the same point, they have the pins arranged on a circumference and move in radial planes, therefore only the type-bar arranged in the middle plane of the levers system will be in the same vertical plane of the corresponding keylever, whilst all other type-bars, will move in .planes morev or less inclined relatively to the corresponding key-lever, and more so the further the latter is from the middle type-bar.

In order that the forces operating on each lever may all act in the plane of the same, it is evidently necessary that all the links 27 and all the levers 19 and 16 should move all of them in the plane of motion of the corresponding typebar. Pins 17 and 20 are located on arcs of circles with their centres arranged on an axis going through the centre of plate 3l. As on the other hand key-levers 2 and bell-crank levers 9 are lying and move all in vertical planes, there folrod 12-13 must operate approximately along the intersection line of the two planes formed by each key-lever and its corresponding type-bar. Such a condition can be obtained by varying for each set of levers the distance between pin 10 and pin 14 which acts on the pull-rod altering therefore the form and length of the arm of the bell-crank levers 9 whose motion is transmitted by the key-levers 2, so as to cause all pull-rods 12 to accomplish exactly the same stroke.

Particularly in the lateral sets in which the angle formed by the plane of the type-bar and the plane of the corresponding key-lever is greater, the pull-rod during its motion will shift, however slightly, away from the intersection line of said two planes.

It is therefore convenient that, as stated above, the pins should be spherical thus allowing said displacement without injurious stresses.

It is nowpossible to see how the system operates: On pressing key 1, motion is transmitted from the bell-crank lever 9 and by pull-rod 12--13 to lever 16, which will swing around its pin 17 with a varying angular velocity, depending on the design of the transmission of motion between levers 2 and 9. By means of its pin 35 engaging in sector 18, lever 16 causes lever 19 to swing around pin 20, moving from the position shown in Fig. 1 to that shown in Fig. 2.

By this rotation lever 19, through link 27, causes the rotation of the type-carrying lever around pin 30, which latter lever moves from its rest position to the printing position (Fig. 2).

It should be noted that the motion of lever 19 is transmitted to the type-carrying lever with a ratio varying according to a trigonometric law. In fact lever 19 and link 27 form a knucklejoint mechanism, because the two members, which in the starting position are almost at right angles to each other, at the end of their swing, have their pins 20--26--28 in alignment, that is in dead centre position, in proximity of which the angular displacements of lever 19 have a 'decreasing influence on the displacement of point 28. It is evident in fact that if we suppose to divide in a certain number of equal parts the total swing of lever 19, to each single and subsequent equal angle of rotation correspond in the typebar-lever 29, angles of rotation decreasing progressively according to a trigonometric law.

It may now be seen with what law motion is transmitted from pin 35 to lever 19. The arrangement of slot 18 is such that at the outset the motion is transmitted rather slowly with positive acceleration. In fact pin 35 in the first part of its swing approaches pin 20 around which swings lever 19, and therefore the angular clisplacements of lever 19 for a certain constant angular rotation of lever 16 will go increasing. Then pin 35 moves again away from pin 20, thus causing a decrease oi angular velocity of lever 19, which decrease is rapidly enhanced by the particular form of the slot, which, when pins 20-26-28 are near to dead centre, combines approximately with a circular slot having its centre in point 17 and having a mean radius equal to the distance between points 17 and 35, so that a further rotational motion of lever 16 will have no appreciable action on the type-bar-lever.

As shown in the drawing, the slot in the lever is formed of a straight followed by a circular part, of course this particular form may be subject to alterations according to the law with which motion has to be transmitted from lever 16 to lever 19, thatis according to the desire of having a more or less sensitive positive acceleration at the beginning and negative acceleration of the end of the swing. Of course the morel thev last part of the' slot' will approach the circular form, with its centre falling in point 17 in its motion, the slower will be the motion with which the type carried by lever 29 will approach cylinder 34 and vice versa, the greater will be the pressure which it will exert, as it covers a very slight displacement for a large swing of lever 16.

There will therefore be no striking of the type on the paper, because said type will bear against it slowly and the impression will be obtained through the great pressure developing in the further displacement which the levers complete up to the dead centre position, that is until points 20-26-28 are in alignment.

A spring 36 which recalls lever 16 is provided in order to retrieve the set in its rest position; also in order that said lever may not reach the end of the slot on account of too great an impulse on the part of the typists finger, striking against said slots end, a cushion 37 of felt, rubber or other proper material, is provided: against this cornes to bear said lever 16 through a part conveniently bent from it.

In order to adjust correctly foreach type-carrying lever, the pressure with which it should bear against the cylinder pin 20 of lever 19 is carried in a particular manner.

Said pin 20 is carried in fact by the angle piece 21 pivoted around pin 22 and whose position can be adjusted and then blocked by the settingscrews 24 and 25. The position of pin 20 is chosen in such a way that the straight line connecting pins 22 and 20 results almost at right angles with the straight line connecting pins 20--26-28 when these are in alignment, namely in the printing position.

With such an arrangement, on acting upon the two screws 25 and 24 and causing the angle plate to rotate somewhat, it is possible to shift slightly the position of point 20, approximately along the line connecting pins 20-26-28, thus adjusting the pressure upon the paper. This adjusting device is given by way of example, and can of course be replaced by any other equivalent arrangement, for instance by a sliding piece adapted for shifting slightly pin 20 along the line connecting 20-26-28 when theyare in alignment. Similarly also the way the motionv is transmitted from the key-lever to lever 16 is shown solely as example, and can be replaced by any other arrangement with levers, slots, etc. adapted to obtain the transmission of motionV preferably with variable ratios and with positive acceleration, in order to overcome the inertia of the system more easily.

In above specification, it has been noted that lever 16 carries pin 35 moving in slot 18 of lever 19. Such an arrangement can of course be reversed, namely the pin can be iixed on lever 19 and the slot out on the end of lever 16, without altering thereby the conditions of operation, as in this case also by properly designing the shape of the slot, the transmission of the motion between the two'levers can be obtained according to any desired law.

What I claim is:

In a typewriter, a frame, a type bar pivoted on said frame, toggle means connected to said type bar including a first lever pivoted on said frame having a slot therein, a key bar pivoted on said frame, means operated by said key bar to move said rst lever including an element having a member engaging in said slot, said lever and element being so arranged and' said slot being so shaped that said member can continue to move in said slot after said type bar reaches printing y position, and an elastic cushion in the path of movement of said element against which said element strikes after the type bar reaches printing position to start the parts on their return movement. GINO MODIGLIAN I.

Cil

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