US727607A - Key-action for type-writing machines. - Google Patents

Description

PATENTED MAY 12, 1903.

R. J. FISHER. KEY ACTION FOR TYPE WRITING MACHINES.

APPLIOATION FILED JUNE 21, 1901;

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No. 727,607. PATENTED MAY 12, 1903.

R. J. FISHER.

KEY ACTION FOR. TYPE WRITING MACHINES.

Agrmon'xon rmm JUNE 21, 1901. no M01139 4 sunrs-snmir 2.

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PATENTED MAY 12. 1903.

R. J. FISHER.

KEY ACTION FOR TYPE WRITING MACHINES.

APPLIOATION FILED JUNE 21, 1901.

4 SHEETSBHEET 3.

NO MODEL.

No. 727,607. PATENTED MAY 12, 1903. R. J. FISHER. 7

KEY ACTION FOR TYPE WRITING M AOHINE S APPLIOATIONIILED mm 21, 1901. 30 MODEL; mums-sum 4.

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Patented May 12, 1909;.

T Fries.

ROBERT JOSEPH FISHER, OF ATHENS, TENNESSEE, ASSIGNOR TO THE FISHER BOOK TYPEWRITER COMPANY, OF CLEVELAND, OI'IIO, A

CORPORATION OF DELAWVARE.

KEY-ACTION FO'R .TYPlE-WRITING MACH N ES.

SPECIFIUATION forming part of Letters Patent No. 727,607, dated May 12, 1903.

Application filed June 21, 1901. Serial No. 65,467. (No model.)

To all whom, it may concern:

Be it known that I, ROBERT JOSEPH FISHER, a citizen of the United States, residing at Athens, in the county of McMinn and State of Tennessee, have invented a new and useful Key-Action for Type-Writing Machines, of which the following is a specification.

My present invention "relates to improvementsin type-writing machines, but has more especial reference to the improvement of the type-bar-operating mechanism.

In all types or classes of type-writing machines embodying movable keys for operating the type-bars it is desirable to produce the lightest possible touch and to eliminate the jarincident to the startingand stopping of the type-bar, and it is furthermore desirable to absolutely eliminate all rebound of the typebar after it has reached its retracted position. The shocks which the operator usually re ceives from the quick or staccato blow upon the key are (1 no to the'inertia of the type-bar, which offers resistance to being suddenly put in motion and tothe sudden arrest of the op erators finger by reason of the contact of the type with the platen. These shocks are comparatively slight; but the vast repetition thereof incidental to the operation of the type-writing machine renders their elimination a matter of some importance. The rebounding of the type-bars after their retrac-' tion is highly undesirable, for the reason that the type-bars so rebounding interfere with the type-bars being operated, and thus prevent the rapid manipulation of the printing mechanism. 7 V p p v The present in vention is especially designed for use in connection with type-writing machines whose type-bars strike downwardly, because the tendency of the bars togravitate from their retracted positions is apt to produce a greater rebound than in those types of machines wherein the force of gravity tends to retain the type-bar in the position to which it is moved after the printing operation. More particularly, however, the invention is contemplated for use in connection with the Fisher type-writing machine, a form of which is disclosed in my former patent, No. 569,626,

which machine is of the type jnstmentioned,

and is furthermore equipped with a type-head of that form disclosed in my concurrent application, Serial No. 28,419, filed August 29, 1900. For the purpose of illustrating the application of the invention, therefore, it is shown applied to a Fisher type-Writing machine; but it will of course be understood that any other machine employing type-bars may be equipped with the improvements contemplated by this invention. 7

The object of the invention, briefly stated, is to lighten the touch by minimizing or practically eliminating the shocks at the beginning and ending of the key-stroke and to antomatically lock the type-bar in its retracted position to prevent it from rebounding upon its sudden retraction after it has been pre sented to the platen.

To the accomplishment of these ends the invention contemplates the interposition, in the line of connectionbetween the key element and the type-bar, of a motion-transmitting element which will serve to lighten the load opposed to the key element at the beginning of the strokeand to graduallyincrease the load after the inertia of the type-bar has been overcomethat is to say, the interposition of the motion-transmitting element is effected in a manner to transmit the motion from the key element to the type-bar in varying ratio, the type-bar being moved a distance of, say, one-fourth of its stroke during the first half of the stroke of the key element, the ratio of movement being then automatically varied to cause an acceleration of the transmitted movement, so that the last half or less of the key-stroke will effect the movement of the type-bar a distance of, say, three-quarters of its stroke. Thus the initial movement of the key being comparatively great to effect the starting of the type-bar, the shock incident to the overcoming of the inertia of the typebar is practically eliminated, and as the in-' crease of the load during the movement of the type-bar is gradual such increase is imperceptible to the operator and serves to absorb the movement of the hand and to minimize the shock occurring at the impact of the type upon the platen.

The means for effecting the several ends stated comprehends the employment of a motion-transmitting element preferably having the form of a bell-crank lever interposed, as already remarked, in the line of connection between the key element and the type-bar, but preferably in the draw-wire connecting the rear end of the key-lever with the rear or lower extremity of the type bar or lever. The fulcrum of the bell-crank lever is fixed, and said lever is connected at separated points to the contiguous ends of the draw-rod sections or to other connecting members, the fulcrum and the points of connection being disposed in triangular arrangement, so that said points of connection will move through arcs having angular relation. The effect of this arrangement of the fulcrum and points of connection is that while said points move through the same number of degrees the movements of the connected elements in a given direction will be of different extent. In other words, the bell-crank lever is so arranged-' as, forinstance, in the illustrated embodiment thereofthat one point of connection will move through a horizontal arc while the other point of connection moves through a vertical arc during the swinging of the bell-crank lever upon its fulcrum, and as a consequence one point of connection will have considerable vertical movement, while the other point of connection will have comparatively slight vertical movement, by reason of the fact that the major portion of the movement of said last-named element will be absorbed by its travel in a horizontal direction. The bell-crank lever thus employed is also disposed so as to normally bring its point of connection with the driven element in looking arrangement with the fulcru m of the bell-crank lever-that is to say,

in such relation to the fulcrum as would bring the strain from the rebounding tendency of the type-bar directly in line with said fulcrum, whereby said fulcrum will effectually resist any rebounding movement of the type-bar, but will offer no resistance to theswinging of the bell-crank lever to cause the actuation'of the type-bar under the impulse of the key element.

The invention further consists in certain details of construction and arrangement, all as will be more fully described hereinafter, illustrated in the accompanying drawings, and succinctly delined in the appended claims;

In said drawings, Figure l is a sectional view'of the traveling type carriage of a Fisher type-writing machine equipped with type-bar-operating mechanism constructed in accordance with my invention. Fig. 2 is a similar view with the type-basket removed and showing a diiferent arrangement of the power-transmitting element. Fig. 3 is asimilar view showing still another embodiment of the invention. Figs. 4, 5, and 6 are diagrammatical views illlustrating the movements ofthe power transmitting element when mounted in accordance with the con structions shown in Figs. 1, 2, and 3, respectively. Fig. 7 is a view of still another arrangement of the power transmitting element. Fig. 8 is a diagrammatical viewillustrating the movements thereof, and Fig. 9 is a detail view of a possible variation in the form of the power-transmitting element or lever.

Like numerals are employed to designate corresponding parts throughout the views.

The front and rear elevated guides l and 2 of the traveling machine-frame (illustrated fragmentarilyin Fig. 1) support in the usual manner the type-carriage 3, usually in the form of a hollow casing, as shown, and supporting thependent frame 4 of the type-basket. \Vithin the casing 3 are pivotally mounted in a manner well understood in the art a series of key-levers 5 of the first class, pivotally connected at their frontendsto the key-stems 6, fitted with suitable keys 7, hearing a character or characters corresponding with the type or types operated by the typebar 8, to which the individual key-lever is operatively related.

In the type of machine illustrated in the drawings the type are designed to impact against the horizontal writing-surface of a platen disposed below the type-basket, and are therefore mounted for downward movement when a type-key 7 is depressed. The

type-bars 8, which are equipped with the heads 9, described and claimed in my application Serial No. 28,419, are disposed normally in an upstanding position, as shown in Fig. 1, and are fulcrumed adjacent to their lower ends, as indicated at 10, the lower or rear extremities of the type-bars being connected to the rear extremities of the key-levers 5 through the medium of vertically-disposed draw-wires 11, comprising upper and lower sections 12 and 13. the type-bar 8 is retracted with more or less violence against the buffer-ring 14 under the impulse of the retracting-spring 15.

It is well understood by those skilled in the art that the rebounding of the type-bar after the retract-ion thereof is objectionable, especially if an adjoining type-bar is thrown down immediately after the stroke of the type-bar retracted, because in this event the rebound is apt to cause colliding of the typebars to the great annoyance of the operator and to cause loss of speed. As heretofore explained, the tendency of the type-bars to rebound is greatest'in machines of that type wherein the rebound of the bars is assisted by gravity. Various expedients for over coming the rebound of the type-bar have been resorted to. One was to make the bufierring as rigid as possible, and another was to set up a much greater tension of the return or retracting springs 15 than was necessary to merely return the type-bars to their normal positions. The'latter expedient, while overcoming the rebound to a considerable extent, resulted in a comparatively hard touch When the key is released,

mate out increasing the resistance at the key, but

should, on the contrary, be accomplished by means which will vary the resistance in a manner to minimize the shocks imparted to the hand of the operator at the beginning and ending of the key-stroke. These desirable results are obtained by the interposition in the line of connection between the key element and the type-bar of a bell-crank lever 16, arranged in a particular manner and constituting a power-transmitting element arranged to transmit motion from the key element to the type-bar in varying ratio, so that a minimum load or resistance is opposed to the initial movement of the key element and is gradually increased after the inertia of the type-bar has been overcome without appreciable shock to the finger of the operator.

In the preferred embodiment of the invention (illustrated in Fig. 1 of the drawings) the power-transmitting element or bell-crank lever 16 is fulcrumed at one end upon a bearing-wire 17, supported by suitable brackets 18, pendent from the bottom 19 of the carriage 3, the bearingwire 17 being sufficiently extensive to accommodate a lever 16 for each type-bar 8. As shown in the drawings, the several levers are retained in properly-spaced relation by the interposition of washers or spacing-sleeves 20. The end of the lever 16 opposite its fulcrum 17 is connected, as indicated at 21, to the upper end of the lower draw-rod section 13, and the connection of said lever with the lower end of the upper draw-rod section 12 is located at the angle of the lever 16, as indicated at 22. For the purpose of defining these several points of connection in the claims I shall define the lever 16 as being provided with a fulcrum, with a type-bar connection and with a key-element connection, and by these latterterms I mean to be understood as indicating those points upon the lever 16 at which it is connected either directly or indirectly to the type-bar or key element, as the case may be. I shall also define the key and the type-bar in certain of the claims as driving and driven elements, and in such case the key connection and the type-bar connection above identified will be termed the d living-element connection and the driven-element connection, respectively.

As shown in Fig. 1, the type-bar connection 21 is disposed normally below and slightly in rear of the fulcrum 17 of the bell-crank lever to position the lower section 13 of the draw-wire nearly in line with the fulcrum. Thus the type-bar in its retracted position will be retained against rebounding movement by an automatic lock, as it will appear iii) that any forward movement of the type-bar away from the bufier-ring 14: must be accompanied by an upward longitudinal movement of the draw-wire section 13, which movement is prevented by reason of the fact that the fulcrum 17 of the bell-crank lever 16 is either located directlyin the line of strain or slightly in front thereof. Therefore when the type-bar is retracted violently against the buffer-ring the connection 21 and. the furcrum 17 of the lever 16 are disposed in locking arrangement, and as the draw-wire section 13 is held against upward longitudinal movement the rebound of the type-bar will be absolutely prevented. It is clear, however, that while the draw-wire section 13 is held against movement and cannot, therefore, yield under power applied thereto from the type-bar the lever 16 may be readily swung upon its pivot by the application of power to the key 7. This is by reason of the fact that when the lever is swung in the manner indicated the first movement of the connection 21 will be in a horizontal direction, and such movement will present the connection 21 in advance of the vertical plane of the fulcrum 17 before the Vertical movement of the connection 21 is appreciable. Thus with the parts in the positions shown in Fig. 1 of the drawings it is impossible to pull the typebar forward, even though considerable force is applied, while the application of very slight pressure to the key 7 will cause the key-lever 5 to be oscillated and the bell-crank lever 16 to be swung to effect the forward or downward movement of the type-bar 8. Considered in this aspect alone the invention is of great practical importance, since the employment of the bell-crank lever in the manner specified provides for the automatic locking of the type-bar in its retracted position, and therefore permits a comparatively light retracting-spring to be employed, to the end that the touch of the key will be very much lighter than is possible Where the retracting mechanism is depended upon to hold the typebar against the buffer-ring. As premised, however, there is still another aspect in which the invention is possessed of special advantages entirely apart from those just noted-- that is to say, the arrangement of the lever 16 in the manner specified permits the movement of the type-key to be transmitted to the type-bar in varying ratio, considerable initial movement of the key being accompanied by comparatively slight movement of the type-bar and the subsequent movement of the key being transmitted to impart a comparatively greater movement to the type-bar.

In Fig. 1 I have illustrated the retracted position of the type-bar in full lines, the position of the type-bar when the key is moved slightly more than one-half of its stroke in heavy dotted lines, and the impacting or printing position of -the type-bar at the end of the key-strokein light dotted. lines, this character of illustration being adopted for the purpose of showing the relative extent of movement of the type-bar and key at different points in the key-stroke. When the key has been moved more than one-half of its entire stroke, the type-bar will have moved about one-fourth of its entire stroke, so that while there is a loss of speed in the initial movement of the load or type-bar there is a proportionate gain of power. After the inertia has thus been overcome and the typebar is in motion the arrangement of the bellcrank lever is such that the movements of the key and type-bar will be efiected in inverse ratio, and the load will thus be increased; but there will be a gain in speed.

Thus during the last half of the key-stroke the type-bar will move through, say, threefourths of its movement and will create suffieient resistance at the key to absorb in large,

measure the shock which would otherwise be incidental to the impact of the the platen.

The transmission of movement from the key to the type-bar in varying ratio has heretofore been effected in several ways, all of which have involved certain sliding connections, which are highly objectionable in typewriter constructions, and where such difierential movement has been secured it has usually been impossible to secure any locking action which would effectually prevent the rebound of the type-bar. The employment of the bell-crank lever 16 in accordance with my invention, however, dispenses with the necessity for the employment of all sliding connections and at the same time secures both the desired differential movement and the automatic locking of the type-bar.

In Fig. 4 is shown a diagram of the lever movements, which eifect the slow movement of the type-bar at first and its subsequent rapid movement after its inertia has been overcome. Referring now to Fig. 4, it will be seen that normally thevtype-bar connection 21 is located almost directly under the fulcrum 17 and that the key connection 22 is located at a considerable distance in advance of the fulcrum. Ifnow the key 7 is depressed one-half of its stroke, the key connection 22 at the angle of the bell-crank lever will move through the vertical arc a b, while the typebar connection 21 will move through the substantially horizontal are c d. The vertical movement of the key connection 22 will thus be from the horizontal plane 6 to the horizontal plane fipractically none of the movement of said connection being absorbed by the horizontal or lateral travel thereof. On the other hand, the movement of the type-bar connection 21, traveling through the substantially horizontal are 0 cl, will be largely absorbed by such lateral movement, and the vertical movement of the connection 21 will therefore be only from the horizontal plane g to the horizontal plane h, and the dilferential movements of the key and type-bar secured during this forward movement of the type against lever 16 will be represented by the difierent distances traveled by the connections 21 and 22. in a vertical direction, it being unnecessary for the purpose of the present illustration to take into account any allowance for the inclination of the draw-wire during the movement of the lever.

It will thus appear that while the upper.

section 12 of the draw-wire 11 moves a distance equal to the interval between the planes 6 and f, the lower section of the draw-wire will move only a distance equal to the distance between the planes 9 and h, and the first half or more of the stroke of the key will therefore result in comparatively slight movement of the type-bar. The change inthe position of the lever now presents the connections 21 and 22 at the beginning of reverselydisposed arcsthat is to say, the connection 21 has arrived at the end of the substantially horizontal are c d and at the beginning of the substantially vertical are d '0', while the connection 22 has arrived at the end of the substantially vertical are a b and at the beginning of the substantially horizontal are I) k. Continued movement of the bell-crank lever 16 under the impulse of the key will therefore move the connection 21 from the horizontal plane it to the horizontal plane Z and will simultaneously move the connection 22 from the horizontal planefto the horizontal plane m. In this instance a reverse diiferential movement is secured, and instead of the movement of the key being in excess of the movement of the type-bar the movement of the type-bar is much in excess of the movement of the key, because while the lower drawwire section 13 has moved the distance of the interval between the planes h and Z the upper section 12 of the draw-wire has only moved the distance between the planesfm.

Instead of locating the bell-crank lever 16 between two sections of the draw-wire, as illustrated in Fig. 1, it is possible to fulcrum the lever upon a suitable support 23 in the type-carriage, as shown in Fig. 2, and to connect the rear end of the key-lever 5 directly to the lever 16 at the angle thereof, slight lost motionbeing provided for by means of the slot-and-pin connection 22 as shown. The principle underlying this application of the invention is precisely the same as that already described; but in Fig. 5 I have shown a diagram showing the manner in which the type-bar connection 21 moves from the plane g to theplane h, and thence to the plane I, while the key connection 22 moves from the plane 6 to the plane f, and thence to the plane m.

A still further embodiment of the invention is shown in Figs. 3 and 6 of the drawings, the location of the lever 16 at the front end of the key-lever 5 instead of at the rear end thereof necessitating the reversal of the position of the bell-crank lever. In this contamer provided with a slot-and-pin connection 22 at its opposite end with the lever 5 and with a similar slot-and-pin connection 21 at its angle with the lower end of the key-stem 6. The differential movements of the key connection and type-bar connection are the same, however, as in the other forms of the invention, as clearly shown in Fig. 6.

A still further embodiment of the invention is illustrated in Figs. 7and 8 of the drawings, wherein the fixed fulcrum 17" of the lever 16 is located at the angle of the lever instead of at one end thereof, as in the several forms already described. In this embodiment the lever 16 is located in the draw-wire, and the type-bar connection 21 and the key connection 22 are located at the ends of the lever. When this arrangement of the powertransmitting lever is employed, the short arm 29 and the type-bar connection 21 will bear such relation to the fulcrum 17 as will effect the locking of the type-bar against rebounding movement, it being possible in this instance, as in the others, to present the typebar connection in exact alinement between the fulcrum and the connection 30 or slightly in rear of the line of strain, as may be desired.

Throughout this specification I have referred to the power-transmitting element as having the form of a bell-crank lever, and while this form is preferable by reason of its simplicity, light weight, 850., it is evident that in lieu thereof it is possible to employ any mechanical element capable of being swung upon a fulcrum and having said fulcrumandthetype-barandkeyconnectionsdisposed so as to produce the relative movements of the key and type-bar necessary to the attainment of the several objects stated. In Fig. 9, for instance, I have shown a disk 31, which may be substituted for the lever 16 without departing from the invention.

It is believed that the construction, operation, and many advantages of the invention will readily appear from the foregoing, and, while the illustrated embodiments thereof are believed at this time to be preferable, I wish to reserve the right to efiect such changes, modifications,and variations of the illustrated structure as may be properly embraced within the scope of the protection prayed.

\Vhat I claim isl. In a type-writing machine, the combination with a type-bar and a key, of a lever having operative connection with each of said elements, the type-bar connection being disposed to assume a locking relation with the fulcrum of the lever in the normal position thereof.

2. In a type-writing machine, the combination with a type-bar and a key, of a bell-cran k lever having operative connection with each of said elements, the type-bar connection being disposed to assume a locking relation with the fulcrum of the lever in the normal position thereof.

3. In a type-writing machine, the combination with a typebar and a key, of a bell-crank lever having operative connection with the type-bar and key, and also having a fixed fulcrum, the type-bar connection being normally located in position to bring the strain exerted thereon by the type-bar substantially in line with the fulcrum of the lever, whereby the type-bar is locked against rebound.

4. In a type-writing machine, the combination with a type-bar and a key, of a bell-crank lever having operative connection with the type-bar and key, and also having a fixed fulcrum, the type-bar connection being normally located in position to bring the strain exerted thereon by the type-bar substantially in line with the fulcrum of the lever to lock the typebar against rebound, and the key connection being normally located in position to permit the swinging of the bell-crank lever by the depression of the key.

5. In a type-writing machine, the combination with a type-bar and a key, of a bell-crank lever having operative connection with each of said elements, and having a fixed fulcrum, the type-bar connection, the key connection and the fulcrum having a triangular arrangement, and the type-bar connection being normally disposed to assume a locking relation with the fulcrum of the lever to prevent the rebound of the type-bar.

6. In a type-writing machine, the combination with a type-bar and a key, of a bell-crank lever having operative connection with each of said elements, and also havingafixed fulcrum, the fulcrum and the type-bar connection beinglocated at the ends of the bell-crank lever, and the key connection being located at the angle of the lever, said type-bar connection being disposed to assume a locking relation with the fulcrum of the lever in the of the lever in the normal position of said lever.

8. In a type-writing machine, the combination with a type-bar, a key-lever, and an interposed draw-Wire, of a bell-crank lever located in the draw-wire and having a fixed fulcrum, and connections with the type-bar and key-lever respectively, the connection of the lever with the type-bar being disposed to assume a position substantially in a line extending from the axis of the lever to that point of the type-bar connected with said lever, whereby the type-bar is locked against rebounding movement.

9. In a type-writing machine, the combination with a type-bar and a key-lever, of a drawwire, and a bell-crank lever located in the draw-wire and having a fixed fulcrum at one end, a connection at its opposite end with that portion of the draw-wire extending to the type-bar, and having a connection at its angle with that portion of the draw-wire extending to the key-lever.

10. In a type-writing machine, the combination with a key and a type-bar, of a lever having connection with each of said elements, said connections being so related to the direction of movement of the connected parts and to the fulcrum of the lever that the change of position of the lever will effect the decrease of the leverage of the key upon the type-bar, and thus increase the speed of said type-bar during the printing stroke.

11. In a type-writing machine, the combination with a type-bar and a key, of a bellcrank lever having operative connection with each of said elements, and having a fixed fulcrum,said connections being so disposed with respect to the fulcrum that the speed of movement of the type-bar will be increased during the printing stroke.

12. In a type-writing machine, the combination with a key and a type-bar, of a bellcrank lever having connection with each of said elements, said connections being so related to the direction of movement of the connected parts and to the fulcrum of the lever that the change of position of the bellcrank lever will effect the decrease of the leverage of the key upon the type-bar and thus increase the speed of said type-bar during the printing stroke.

13. In a type-Writing machine, the combination with the type-bar, a key-lever, and a vertical draw-wire, of a bell-crank lever located in the draw-wire and having a fixed fulcrum, and connections with the key-lever and type-bar respectively, said connections nection at its opposite end with the type-bar, and a connection at its angle with the keylever.

15. In a type-writing machine, the combination with a driving element and a driven element, as for instance a key-lever and a type-bar, of a bell-crank lever having connection with each of said elements, the driving-element connection being initially movable through an are disposed lengthwise of the line of movement of the connected part of the driving element, and the driven-element connection being initially movable through an are disposed transversely of the line of movement of the connected part of the driven element, the swinging of said bellcrank lever serving to change the relation of the parts to cause the driving-element connection to move through an are disposed transversely of the line of movement of the driving element, and to cause the driven-element connection to move through an are disposed lengthwise of the line of movement of the driven element,whereby the leverage will be decreased du ring the transmission of movement.

16. In a type-writing machine, the combination with a type-bar and key, of a lever having operative connection with each of said elements, said connections being so disposed that the speed of the type-bar will be increased during the printing stroke, and said type-bar connection being disposed to assume a locking relation with the fulcrum of the lever in the normal position thereof.

17. In a type-Writing machine, the combination with a type-bar and a key, of a bellcrank lever having operative connection with each of said elements, said connections being so disposed that the speed of the type-bar will be increased during the printing stroke, and said type-bar connection being disposed to assume a locking relation with the fulcrum of the lever in the normal position thereof.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

ROBERT JOSEPH FISHER.

Witnesses:

A. R. WVARNER, OHAs. F. LAGANKE.

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