US2392276A - Typewriting machine - Google Patents

Description

Jan 1, 1946 RyvoN REPPERT TYPEWRITING MACHINE Filed Dec. 11, 1943 2 Sheets-Sheet 1 A TTOHNE Y un .N

E Y ww km L Jan. 1, 194s. R VON REPPERT 2,392,276

TYPEWRITING MACHINE Filed Dec. ll, 1943 2 Sheets-Sheet 2 m, FIG. V635/53a A TTORNE Y UNITED STATES PATENT OFFICE TYPEWRITING MAcHmE- l Richard von Reppert, Rochester, N. Y., assigner to'lnternational Business Machines Corporation, New York, N. Y., a corporation of New York Application December 11, 1943, Serial No. 513,839

- 7 Claims. (Cl. 197-1i) This invention relates to typewriting machines.

An object of the present invention is to provide l a more quietly operating typewriting machine. An object is to provide a quietly operating type bar action.

Another object vis to'provide a quiet type bar I action which is suitable for operation by power.

An object is'to provide a novel type bar aligning means.

Another object is to provide means for preventing rebound of the type bars.

Other objects oi' the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by Way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

A divisional application Serial No. 552,245 illed September 1, 1944 is directed to the type bar aligning mechanism.

In the drawings:

Fig. 1 is a vertical section;

Fig. 2 is a large scale horizontal section on the line 2&2 in Fig. 1;

Fig. 3 is a large scale front elevation of the aligning means;

Fig. 4 is a plan view of the aligning means;

Fig. 5 is a vertical section on the line 5--5 in Fig. 32

Fig. 6 is a. plan view similar to Fig. 5 and showing a type bar under the control of the aligning means at the moment of impact. I

Fig. 1 illustrates in vertical section a machine embodying the novel type bar action and type bar aligning means of the present invention. In this view the numeral I0 designates in dot-dashoutline a portion of the base or housing frame which supports various cross frames and support bars carrying the mechanism. The numeral II designates one of the keys of the keyboard which keys are guided at their front or righthand-ends (Fig.

1) in a key comb I2. sound deadening strip I 3.

Each key II is somewhat T-shaped in general shape (Fig. 1) and one end of the crossbar of the T isformed with a hooked shaped portion IIa by means of which the key II is pivotally suspended from a fulcrum bar I4 secured to an angle strip I5 suitably mounted in the base I0. The fulcrum bar I4 also has secured thereto a comb I6 which spaces the key extensions I la of all the keys apart. The portion IIb of the crossbar of each key II extends downwardly and is slotted to embrace a pin 11a on the trip lever I1b lof a cam unit generally designated I1. There is pro- The latter also supports a vided a cam unit I1 for each key II and its associated typebar. The cam units are of a conventional Iorm well known in the art and are pivotally supported by a fulcrum wire I8 carried by a crossbar I9 mounted in the base I0. The cam units I1 have cams I1c which cooperate with a power roller 28 which rotates continuously in the direction of the arrow in Fig. 1 while the machine is in use.

When a key II is depressed, the extension IIb rocks the trip lever I1b'counterclockwise (Fig. 1) and causes the cam llc vto become operatively engaged with the power roller 20 in a well known way. The power roller, by rotating the cam Ilc a half revolution, eiIects clockwise rotation of the cam unit I1. y

The cam units I1 are connected by links 2| (Fig. 1) to intermediate levers 22 pivoted at 28a to short bars 23. The bars 23 are received in horizontal slots in a crossbar secured in the suitably supported in the base I 0.

'I'he type bars are designated 21 (Figs. 1 and 2) and are pivotally mounted in the segment 28 by means of a fulcrum wire -29 received injan arcuate slot in a rib 28a formed on the top face of the segment 28, as best shown in Fig. 2. As usual,

the type bars 21 are arranged fan-shaped (Fig. 2)

in an arc oi' a circle, which, in the present case, is approximately 102. The segment 28 is secured to an angle bar 38 suitably supported in the base I0. i

` Associated with each type bar is a separate train of operating mechanism or. action which is actuated by the appropriate one of the intermediate levers 22. This train of mechanism is conveniently mounted on a removable support plate which enables the parts comprising the type bar action for a single type bar to be removed as a unit when required in servicing the machine. These plates are mounted in fan-shaped relation so as to be approximately co-planar with the type bars.

In the case of the type bar 21 shown in Fig. 1, the support rplate is designated` 8| and is formed with a round-nosed lug lla resting in a groove 32a formed in a curved crossframe 32 suitably supported in the base l0. The plates 3l are spaced from each other by a flat curved comb plate 33 secured to the top face of frame 32 and the groove 32a is concentric with the groove of the pivot wire 29, or at least lies in a cylinder which is concentric with a cylinder containing the pivot wire 29 toinsure that the distance between the pivot wire 29 and the lug 3|a may be constant for all of the ytype bars 21 and their supporting plates 3| The plates 3| are held with their lugs 3|a (Fig. 1) in the groove 32a in bar 32 by means of springs like 34 which are anchored to a curved angular strip 35 secured to the frame 32 and to holes in plates 3|.

Each of the plates 3| is f ormed with an upwardly extending arm 3|.b which is guided in`a comb 36 secured to the top face of a curved frame 31. Springs 38, anchored to hooks formed in the plates 3| and to a spring anchoring strip 39 secured to the frame 31, hold the extension arms 3|b against stop screws 40 carried by the frame 31. The plate 3| is also formed with a second extension arm 3|c formed with a lug 3|d received in a curved comb 4| fixed to the face of a curved strip 42 carried by the frame 43.' This frame is suitably supported in the base I and is curved concentrically with the frames 3'2 andv 31. The strip 42 is formed with a flange along its upper edge and has secured to its rear face a curved angle strip 44 supporting a resilient rebound strip 45 for the type bars 21. Each of the type bars 21 is formed with a pad or shoe 46 which engages the. rebound strip 45 to spread the force of rebound over a relatively large area of the rebound strip 45 to reduce cutting said strip.

The type bars 21 are formed with extensions 21a .(Fig. 1) which engage flat springs 41 secured to the under edge of the frame 43. These springs 41 are flexed to the broken line position of Fig. 1 when the type bar is operated and assist in restoring the type bars and parts of the type bar action after each operation. Each type bar is connected by a toggle link 48 to a toggle link 49 pivoted at 3|e to the `extension 3|b of frame 3|. The` link 49 has a short extension arm which is connected by a link to a three arm lever 5| pivoted at 3|f to the plate 3|. One of the arms of each lever 5l is formed with a curved surface 5|a engaging a leaf spring 52 clamped to a bent-over lug 3|g formed in the associated frame 3|.

Pivoted at 3|h (Fig. 1) is an arm 53 which extends over the third arm 5|b of the lever 5| so as to be engageable therewith when the arm 53 is rocked, clockwise. Arm 53 is connected by a vertical link 5 4 with one arm of a lever 55 pivoted at 3|i to the plate 3| adjacent the lug 3|a. The lever 55 is urged in a clockwise direction by means of a spring 56 anchored to the other arm of lever 55 and to a lug formed in the plate 3|. The rst arm of lever 55 in turn is connected by :2link 51 to the appropriate intermediate lever Operation of the train of mechanism just described is as follows: When the key is depressed the cam unit I1 is rendered operable by the power roller and draws down the link 2| to rock the intermediate lever 22 clockwise. This movement is transmitted to the arm 53 through the link 51, the lever 55, and the link 54, thereby rocking the arm 53 clockwise.` The latter engages the third arm 5|b` of the lever 5| `and rocks the latter counterclockwise thereby thrusting the link 5|) to the left, rocking the toggle link 49 clockwise, and, through the toggle link ,48 the type bar 21 is actuated counterclockwlse to the printing position shown by dot-dash lines in Fig. 1.

The type bar 21 may be positively driven through approximately three fourths of its stroke by cam unit |1 and thereafter the further operation of the type bar is effected bythe momentum of the type bar itself and the members 48,

49, 50 and 5| against the opposing force of the.

restoring spring 52 which is flexed when the lever 5| is rocked to actuate the type bar. As the type bar 21 approaches the printing point, the toggle links 48, 43 straighten out and check the .momentum of the type bar causing it to print through the inking ribbon by pressure `rather than by percussion.

The arm 53 is operated through a predetermined distance by the cam unit |1 which may be materially less than the whole distance travelled by the third arm 5|b of lever 5| which said arm 53 engages, which the result that arm `53A completes its stroke and the cam unit |1 and parts connected thereto'at least start to restore before the type Ibar starts its restoring stroke.- This causes the type bar action to operate more quietly than heretofore because the restoring of the parts is divided into several phases so that the noises arising from the arrival of the parts back at their normal positions do not coincide but are spread over a period of time and at the same time their individual intensities are reduced. This is largely due to the fact that the power. type bar actuating means is not unyieldingly connected to the type bar itself through the type bar action, whereby there is considerably less momentum in the restoring movement of the type bar, thereby re ducing the noise of the shock produced when the parts arrived at their home position and at the same time reducing the tendency to rebound.

Since the train of connections lfrom the cam unit |1 to the type bar 21, unlike prior art constructions, is not composed of parts such as levers and links inseparabiy interconnected so as to compel movement of all parts together but is broken between arm 5|b and arm 53 so as to constitute a positive drive in only one direction, it is possible for the power operating mechanism tol not greatly affected by the momentum of the restoring type bars, the restoration of the power mechanism is effected more quietly. Thus, the noise for which the restoration of the power mechanism is responsible is not merely out of synchronism with the noise arising from restoration of the type bar, but also is diminished in volume. In other words, instead of a plurality of synchronized clicks heard as one big noise, there is produced several non-synchronized clicks of lesser magnitude and hence less noticeable.

There is some tendency for the type bars and the parts directly connected thereto to rebound during a restoring movement and this is prevented by means of a rebound check member 60 having a slot through which passes a pin 5|c carried by the lever 5|. The. member 60 is approximately T-shaped in outline with the crossbar, of the T extending symmetrically above and below the pin 5|c and engaged by a fiat spring 6| secured to an offset lug formed in the member 5|. This spring presses the member 60 to the lei't in Fig. 1 to the limit of theA slot in said member and also holds said member in the slanting position there shown which, in the normal positions of the parts prevents counterclockwlse rotation of the lever I by engagement with the end of arm 53, a slight clearance being provided to insure that the lefthand end of member 60 will always snap in front of the end of the arm 53 when the parts are restored. A gap is provided between the arm 53 and arm 5Ib so that. when the c am unit oper ates the type bar as described above, the arm 53 will be drawn downwardly for enough for the end of the arm 53 to clear the end of the rebound member 50 before engaging the arm 5ib of lever 5i to rock said lever counterclockwise. As the lever 5i rocks in this fashion the end of the member 55 passes to the left over the pivot of' the link 5I to the arm 53.

The cam unit I1 and the parts directly connected thereto up to and including the arm 53 are restored by spring 55 well in advance of the restoration of the type bar 21 with the result that the end of the arm 53 will be rising while the type bar is restoring thus resulting in rocking member 50 clockwise on the pin 5Ic against the tension of the spring 6|. In other words, an upward thrust of the arm 53 is transmitted to the lever 5i through the member' 50 andl spring 5i thereby assisting the restoring movement of the type bar. This also exerts a slight Jretarding effect on arm 53 due to the reaction imposed by spring 5i and lever 5i which helps to restore the cam unit i1 and parts connected thereby more smoothly and with less shock.

In its restoring stroke, the lever 5i draws the member 60 to the right in Fig. 1, dragging said member over the end of arm 53, until said member snaps in front of the end of arm 53; If now the type bar and other members involved in the train of connections from the type bar to the lever 5i tend to rebound, the member 60, will, by engagement with the arm 53, prevent rebound. The slot in the member 60 embracing pin 5ic allows a small amount of yielding movement which may assist in quieting the stoppage of the type bar and connected parts during the restoring movement. The spring 6I also prevents bending the type bar or any of the parts in the mechanical train to and including lever 5| in the event an attempt is made to move the type bar by hand, the spring 6 I yielding under these conditions.

In order to insure that the member 60 will not be accidentally pushed downwardly below the position of Fig. 1, there is provided a stop pin Sib which limits counterclockwise movement of member 60. This pin is not necessary in the normal operation of the mechanism because of the fact that the spring 6i presses against the fiat edge at the right hand end of the member 60 which edge is more or less symmetrical with respect to the pin 5ic and will hold the member 60 in the position of Fig. 1 independently of the pin 5 I d. However, there is a possibility that in servicing the machine the member 60 might be pushed' downwardly accidentally far enough to be retained in a vertical position by the spring 6 l In order to permit the lever 5| to rock clockwise when the cam unit i1 is operated, a clearanceis provided between the end of the arm 53 and the arm 5i b of lever 5i sufilcient to enable the arm' 53 to clear the member- 60 before the lever 5i starts to rock. On account of the resistance which the arm 53 gives in the restoration of the type bar through the member 50', thevspring 52 may be of weaker tension than would ordinarily be the case, consequently, the restoration of the-type bar may be effected more quietly and with less rebound than'is the case where relatively strong springs are directly connected'to the type bars or to the sub-levers of conventional type bar actions com prising inflexibly coupled elements.

'I'he type bars 21'being disposed fan-shaped, the type bars in the center strike the work sheet on platen 65 virtually normal to-the surface while the body of the type bar so as to enable all type faces to strike the platen normally. In the present case the type bars 21 are substantially fiat but the bulk of the type elements 21a are shaped as shown in Fig'. 6 so that the faces of the types make an angle of approximately 45 or less to the axis of the type bar. This, of course, is a feature old in the art.

Provision is made for aligning the type elements and guiding them in a direction normal to the platen while the type elements are eifecting their impression on a work sheet on the plater` through the usual inked ribbon not shown.

Secured to the top surface of the segment 25 is a bracket (Figs. 1 and 3) 'which is formed with horizontal bent over flanges 66a in which are vertically guided the rods STL, G1R.. These rods are so shaped that they are crossed for a purpose which presently will be made clear. Secured to the upper end of the bracket 56 is an inverted U-shaped plate 68 the rear face of which is slotted to vertically guide the type aligning elements BSR, GSL, the guiding elements being held in the guide slots in plate 68 by means of a plate 63a secured to the back of the upper end of the plate l 68. The guide elements BBR, GSL are formed with bent over lugs 69a which are engaged by the upper ends of the rods G1R, 61L, the rod G1R engaging the lug 69a for the element 69B. and the rod 511,

similarly engaging the element BSL.

The elements SSR, GSL are provided with pins 1i which extend through holes in the plate 65 which are considerably larger than the pins 1i whereby the edges of the holes ,act as stops in lcooperation with the pins 1I to limit the sliding movement of elements GSR, GSL. Normally the pins 1i are pressed downwardly on the lower edges of the holes in plate 68 by means of wishbone springs 12, each coiled around a pair of pins carried by plate 68. `Each element BSR, 6HL has' formed therein at its upper end a bent over lug 10R, 10L. These lugs are slightly beveled at 69h forming a cam surface the function of which will be made clear.

Normally both of the guide elements BSR, BSL are held in the lowered or retracted position (Fig. 1) by the springs 12 so as to be slightly below the position of the lower type on the type element at the moment of striking the work sheet. When either or both of the elements BSR, GSL, is raised, however, the lugs 10R, 10L will be raised to the dotted position (Fig. 3) sufficiently to enable thev the aligning elements GSR, 69L are raised the lugs 1UR, 1ilL thereof will be positioned ona level with this notch as shown by broken lines in Fig. 3. Movement of the elements 59E, SQL is effected selectively by a universal bar mechanism which conveniently may be operated directly by the type bars in moving to printing position.`

Three universal bars are provided designated 14R, 14M and ML (Figs. 1 and 2), which consist of fan-shaped flat plates pivoted on a curved fulcrum wire located in a groove formed i-n a rib 28D integral with the segment28. The forward or lower edgespFig. 2, of the universal bars 14R,

-l4M, ML are curved to coincide with an arc of a circle whichisconcentric with the pivot wire 29 and are located so as to be engaged by the curved parts 21d (Figs. 1 and 2) of the type bars 2l adjacent the pivot wire 29. The universal bars 14R, 'ML are formed with rearward extensions 14a which underlie the lower ends of the rods G1R, GIL. The extension 14a of the universal bar 'MR presses lightly against the lower end of the rod 6'lL while theY extension for the universal bar 'NL presses against the end of the rod G1R. The universal bar '14M has secured to it a crossbar Nb which extends on each side to overlap the universal bars 14R, 'ML respectively.

It is clear from the foregoing that when the front ends of the universal bars 14R, ML are depressed, the rods GTL, STR will be raised respectively. When the universal bar 14M, however, is operated both the universal bars 14R, 'HL will be actuated and Araise both rods G1R, GTL simultane ously.

'Ihe universal bar' 14M is associated with a small group of type bars 2l (Fig. 2) located at the center of the segment which makes small angles with the platen. While the universal bars 14R, 'ML are respectively associated with the remaining type bars to the right and to the left.

When a type bar in the lefthand group (Fig. 2) with which the universal bar 'ML is associated, is actuated, the extension 14a of the universal bar 'ML will raise the rod BIR and thereby will raise the righthand aligning element 69B. (Figs. 3 and 6), this action taking place concomitantly witl. the progress of the operated type bar toward the printing point. As a result, when the operated type bar is within a very short distance of the work sheet, the type element 21o will strike the cam surface 69h of the lug 'IBR on aligning element SSR and be guided into cooperation with the vertical flat lefthand edge 69a of the lug 'IGR as in Fig. 6. which, in turn, will force the typ element 21C, to travel rearwardly or straight upwardly in said iigure so as to strike the work sheet normally through notch 68a.

Similarly, when a type bar in the righthand group (Fig. 2), associated with the universal bar 14R is operated, the type aligning element 69L will be raised and guide the type element for said type bar normally to the platen to effect the im- 14R, 'ML will be actuated along with the universal bar 14M and will raise both type guide elements 69B, GSL and lugs TUR, '|0L, which together will form a narrow throat to guide the operated type bar normally of the platen;

In the case of all of the type bars, with the exception of the one or two at the center of the segment, there is a tendency of the type elements to slide on the work sheet parallel with the axis of the platen and this is prevented by the lugs TUR, IDL which, by engagement; with the type elements, force them to travel in a direction normal to the platen in eiectin'g an impression. In the case of the type bars associated with the universal bar 14M there is relatively little tendency for the type elements vto slide in eiecting the impression but, on account of the flexibility of the type bars, they tend to vibrate laterally in both directions and this is prevented by cooperation between both aligning elements TSR, 19L, which function under these conditions in much the same general fashion as in a conventional type guide in which the guide lugs are iixed relative to each other and to the type basket.

The main advantage of th'is construction is that a very complexly milled type guide element, such as has been used in present commercial nolselessv machines is avoided. Such Iixed elements are very diiicult to manufacture and expensive since the xed guiding surfaces must be designed to accommodate a minimum of twenty one different angles of approach of the type bars. Furthermore, when such xed type guides wear, as soon happens in normal use, a noticeably poor alignment of the characters develops which' is characteristic of commercial noiseless machines.

Another advantage is that a larger number of type bars may be provided since a larger angle of approach may be accommodated than is the case with type guides hitherto provided in socalled noiseless typewriters. This results in very materially reduced cost of the type bars and greatly simplifies the problem of manufacturing accurately aligned types since only two types per type bar have to be aligned or replaced instead of four. On account of this feature, the replacing of defective or worn type bars is much cheaper and may be more conveniently accomplished. Furthermore it is unnecessary to disturb the alignment of the characters for two keys to repair misalignment or fracture of the types for a single key,

While there have been sh'own and described and pointed out the fundamental novel features of the invention as applied to a single embodiment it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art, without department from the spirit of the invention. It is the intention, therefore,v to be limited only as indicated by th'e scope of he' following claims.

What is claimed is:

1. In combination with a type bar, a type bar actuating member, a driving member engageable with said actuating member and having driving engagement with said actuating member only through aportion of the stroke of the actuating member, means to restore said driving member in advance of restoration of the actuating member, and means resiliently connected to said actuating member and operated by said driving member during the restoration of the latter for imparting a cushioning restoring force to said actuating member.

2. In a type bar action, an actuated member, a driving member engageable with the actuated member to actuate the latter th'rough a portion of its operating stroke, means to restore the driving member while the actuated member is still in its operating stroke, and means yieldingly mounted on said actuated member enabling the driving member to apply a restoring force to the actuated member to assist in restoring the actuated member upon the completion of its operating stroke.

3. In a type bar action, a rock lever, a. driving member actuable into engagement with said lever to positively drive said lever through only a portion of the stroke of said lever, means to at least partially restore said driving member while said lever is completing its 'operating stroke, and means pivotally yieldingly mounted on said lever and engaged by said driving member while the latter is restoring for restoring said lever.

4. In a type bar action, a rock lever, a driving member actuable into engagement with said lever to positively drive said lever through only a portion'll of the stroke of said lever, means to at least partially restore said driving member while said lever is completing its operating stroke; and spring actuated means pivotally mounted on said lever and engaged by said driving member while the latter is restoringi'or restoring said lever, said means being automatically positioned upon full 4"restoration of the rock lever to lock said lever against operation other than by the driving member.

5. In. a type bar action, an actuated member, a driving member engageable withl the actuated member to actuate the latter through a portion of its operating stroke, means to restore the driving member while the actuatedmember is still in its operating stroke, and spring actuated detent means pivotally mounted on the actuated e. In combination with a type bar, a type bail actuating member, a driving member engageable with said actuating member and having driving engagement with 4said actuating member only through a portion of the stroke of the actuating member, means to restore said driving member in advance of restoration of the actuating member; and separate means movably mounted on said actuating member and operated by said driving member during the restoration of the latter for imparting a restoring force to said actuating member and positioned for enabling the driving member to apply a restoring force to the actuated member to assist in restoring the actuated member upon the completion of its operating stroke, said means normally locking the actuated member against operation other than by the driving member,

member, said last named means being so constructed and arranged as to automatically move to a position to prevent rebound of the type bar at the end of its restoration.

'1. In a type bar actuating mechanism, an actuated lever, an actuating member having an initial idle movement to engage and drive the actuated lever, and a detent mounted on said lever and normally in alignment with a part of said member so as to prevent movement oi' said lever, said part moving out of alignment with said detent during said initial movement to permit movement of said lever by said member; said detent being yieldingly pivotally mounted on said lever so as to constitute a yielding driving arm movable after said initial movement to a position to be engaged by the actuating member in its restoring stroke so as to offer yielding opposition to the, restoration of the actuating member so as to simultaneously cushion the restoring movement of the actuating member and restore the actuated member.

- RICHARD vonV REPPERT.

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