US2396401A - Typewriting machine - Google Patents

Description

arch E2, @946. R. VON REPPERT TYPEWRITING MACHINE Original Filed Dec. 11, 1943 2 Sheets-Sheet 1 H m T vllllllll 400" III/III,

1946- R. VON REPPERT TYPEWRITING MACHINE Original Filed Dec. 11, 1945 2 Sheets-Sheet 2 A TTORNEY Patented Mar. 12, 1946 TYPEWRITIN G MACHINE Richard von Reppert, Rochester, N. Y., assignor to International Business Machines Corporatlon, New York, N. Y., a corporation of New York Original application December 11, 1943, Serial No.

Divided and this application September 1, 1944, Serial No. 552,245

3 Claims.

This invention relates to typewriting machines.

This is a division of application Serial No. 513,939. filed December 11, 1943, by Richard v. Reppert, containing claims to the type bar action, whereas the present application claims the type bar aligning means.

The primary object of the present invention is to provide a novel type bar aligning means for typewriting machines.

An object is to provide a type bar aligning device suitable for use in noiseless typewriters in which type elements strike the work sheet at various angles, instead of at right angles as in machines having the type bars pivoted so that the type elements travel in arcs of circles intercepting the printing plane normally,

An object is to provide a type aligning device or guide which eliminates the necessity of providing a complexly milled type guide at the printing point to accommodate every possible angle of approach of a type member to the platen.

An object is to provide a type guide or aligning device which permits a larger angle of approach of the type member to the platen in order to thereby permit a larger number of type'members to be used.

Other objects of 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.

Fig. l 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 55 in Fig. 3;

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

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 Ill designates in dot-dash outline. a portion of the base or housing frame which supports various cross frames and support bars carrying the mechanism. The numeral ll designates one of the keys of the keyboard which keys are guided at their front or righthand ends Fig. l) in a key comb I2. The latter also supports a sound deadening strip I3.

Each key H is somewhat T-shapecl in general 55 shape (Fig. l) and one end of the crossbar of the T is formed with a hooked shaped portion Ha by means of which the key H is pivotally suspended from a fulcrum bar It secured to an angle strip I5 suitably mounted in the base Ill. The fulcrum bar I also has secured thereto a comb l6 which spaces the key extensions I la of'all the keys apart. The portion llb of the crossbar of each key I l extends downwardly and is slotted to embrace a pin I'la on the trip lever Nb of a cam unit generally designated II. There is provided a cam unit I! for each key H and its associated type bar. The cam units are of a conventional form well known in the art and are pivotally supported by a fulcrum wire 18 carried by a crossbar 19 mounted in the base It. The cam units l! have cams l'lc which cooperate with a power roller 20 which rotates continuously in the direc tion of the arrow in Fig. 1 while the machine is in use.

When a key II is depressed, the extension llb rocks the trip lever Ilb counterclockwise (Fig. 1) and causes the cam l'lc to become operatively engaged with the power roller 20 in a well known way. The power roller, by rotating the cam He 2. half revolution, effects clockwise rotation of the cam unit I].

The cam units H. are connected by links 2| (Fi l) to intermediate levers 22 pivoted at 23a to short bars 23. The bars 23 are received in horizontal slots in a crossbar 24 secured in the base Ill and are individually clamped in said slots by any suitable means such as a screw 25 and a suitable washer, the screws 25 being received in threaded holes in the crossbar 24. By this construction, the short bars 23 may be adjusted horizontally a limited extent. counterclockwise movement of the intermediate levers 22 is restricted by a resilient stop bar 26 which may consist of a strip of resilient material such as rubber secured in a channel shaped of metal suitably supported in the base It.

The type bars are designated 21 (Figs. 1 and 2) and are pivotally mounted in the segment 28 by means of a fulcrum wire 28 received in an ampate 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 of a circle, which, in the present case, is approximately 102. The segment 28 is secured to an angle bar 30 suitably supported in the base It.

Associated with each type bar is a separate train of operating mechanism or action which is actuated by the appropriate one of the interplate which enables the parts comprising the.

type bar action for asingle type bar to beremoved as a unit when required in servicing the machine. These plates are mounted in fanshaped relation so as to be approximately coplanar with the type bars.

In the case of the type bar 21 shown in ig. 1, the support plate is designated 3| and is formed with a round-nosed lug33|a resting in a groove 32a formed in a curved crossframe 32 suitably supported in the base.-|0. The plates 3| are spaced from each other by a fiat 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 23,.or atleast lies in a cylinder which is concentric with a cylinder containing the pivot wire 29 to insure that the distance between the pivot wire 29 and the lug 3|a maybe constant for all of the type 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 formed 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 33 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 theface of a curved strip 42 carried by the frame 43. This frame is suitably supported in the base l and is curved concentrically with the frames 32 and 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 45 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. I

The type bars 21 areformed 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 50 to a three arm lever pivoted at 3| 1 to the plate 3|. One of the arms of each lever 5| 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 SI?) of the lever 5| so as to be engageable therewith when the arm 52 is rocked clockwise. Arm 53 is connected by a vertical link 54 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 first arm of lever 55 in turn 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 '"rocksthe latter counterclockwise thereby thrustv ing the link 50 to the left, rocking the toggle link 43 clockwise, and, through the toggle link .48,.the type bar 21 is actuated counterclockwise 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 strokeby cam unit I1 and thereafter the further operation of the type bar is effected by the momentum of the type bar itself and the members 48, 49, 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 43, 49 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 H which may be materially less than the whole distance travelled by the third arm 5"; of lever 5| which said arm 53 engages, with the result that arm 53 completes its stroke and the cam unit l1 and parts connected thereto at least start to restore before the type bar 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 to 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 reducing the noise of the shock produced when the parts arrive at their home position and at the same time reducing-the tendency to rebound.

Sincethe train of connections from the cam unit H to the type bar 21, unlike prior art constructions, is not composed of parts such as levers and links inseparably 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 to complete its operating cycle more rapidly and become restored well in advance of restoration of the type bar. Since the power mechanism is 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 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 |c carried by the lever 5| The member 6|! is approximately T-shaped in outline with the crossbar oi the T extending svmmetrically 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 left-in Fig. l to the limit of the slot in said member and also holds said member in the slanting position there shown which, in the normal positions of the parts prevents counterclockwise rotation of the lever 5| by engagement with the end of arm 53, a slight clearance being provided to insure that the lefthand end of member 63 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 5|b so that. when the cam unit operates the type bar as described above. the arm 53 will be drawn downwardly far enough for the end of the arm 53 to clear the end of the rebound member 60 before engaging the arm 5|b of lever 5| to rock said lever counterclockwise. As the lever 5| rocks in this fashion the end of the member 60 passes to the left over the pivot of the link 54 to the arm 53.

The cam unit I! and the parts directly connected thereto up to and including the arm 53 are restored by spring 56 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 60 clockwise on the pin 5|c against the tension of the spring 6|. In other words, an upward thrust of the arm 53 is transmitted to the lever 5| through the member 60 and spring 6| thereby assisting the restoring movement of the type bar. This also exerts a slight retarding effect on arm 53 due to the reaction imposed by spring 6| and lever 5| which helps to restore the cam unit I! and parts connected thereby more smoothly and with less shock.

In its restoring stroke, the lever 5| draws the member 60 to the right in Fig. l, dragging said member over the end of arm 53. until said member snaps in front of the end of arm 53. If new the type bar and other members involved in the train of connections from the type bar to the lever 5| tend to rebound, the member 60 will, by engagement with the arm 53, prevent rebound. The slot in the member 60 embracing pin 5|c 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 6| 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| 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 5|b which limits counterclockwise movement of member 6|]. This pin is not necessary in the normal operation of the mechanism because of the fact that the spring 6| presses against the fiat edge at the right hand end of the member Ill in the position of Fig. 1 independently of the pin 5|d. However, there is a possibility that in servicing the machine the member might be pushed downwardly accidentally far enough '0 be retained in a vertical position by the spring 6| In order to permit the lever 5| to rock clock wise when the cam unit I! is operated, a clearance is provided between the end of the arm 53 and the arm 5|b of lever 5| sufficient to enable the arm 53 to clear the member 60 before the lever 5| starts to rock. On account of the resistance which the arm 53 gives in the restoration of the type bar through the member 60, the spring 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 comprising infiexibly coupled elements.

The type bars 2'! being disposed fan-shaped. the type bars in the center strike the work sheet on platen virtually normal to the surface while the end type bars strike at an acute angle. Therefore, it is necessary to either bend the type bars varying amounts or to construct the type elements so that the type faces make varying angles with the body of the type bar, so as to enable all type faces to strike the platennormally, In the present case the type bars 21 are substantially flat but the bulk of the type element 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 effectin their impression on a work sheet on the platen through the usual inked ribbon not shown.

Secured to the top surface of the segment 23 is a bracket 66 (Figs. 1 and 3) which is formed with horizontal bent over flanges 66a in which are vertically guided, the rods 61L, 61R. 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 66 is an inverted U-shaped plate 68 the rear face of which is slotted to vertically guide the type aligning elements 69R, 69L, the guiding elements being held in the guide slots in plate 68 by means of a plate 68a secured to the back of the upper end of the plate 68. The guide elements 69R, 69L are formed with bent over lugs 69a which are engaged by the upper ends of the rods 61R, 61L, the rod 61R engaging the lug 69a for the element 69R and the rod 61L similarly engaging the element 69L.

The elements 69R, 69L are provided with pins H which extend through holes in the plate 68 which are considerably larger than the pins 1| whereby the edges of the holes'act as stops in cooperation with the pins H to limit the sliding movement of elements 69R, 69L. Normally the pins H 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 69R, 69L has formed therein at its upper end a bent over lug 10R, 10L. These lugs are slightly beveled at 69b forming a cam surface the function of which will be made clear.

Normally both of the guide elements 69R, 69L 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 R, "L, is raised, however, the lugs R, 10!.- will be raised to the dotted position (Fig. 3) sufficiently to enable the cam surface or. surfaces 59b to engage the type element to the point 21b (Fig. 1) and guide it normally of the platen into engagement with the work sheet.

The plate 88a is provided with a clearance notch 68b through'which the heel portion 21b of the type element 210 passes in printing. When the aligning elements 89R, 69L are raised the lugs 10R, 10L thereof will be positioned on a level with this notch as shown by broken lines in Fig. 3. Movement of the elements 69R, 69L 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 HR, HM and ML (Figs. 1 and 2), which consist of fan-shaped fiat plates pivoted on a curved fulcrum wire located in a groove formed in a rib 28a integral with the segment 28. The forward or lower edges, Fig. 2, of the universal bars "R, "M, "L are curved to coincide with an arc of a circle which is concentric with the pivot wire 28 and are located so as to be engaged by the curved parts 21d (Figs. 1 and 2) of the type bars 21 adiacent the pivot wire 29. The universal bars "R, L are formed with rearward extensions 14a which underlie the lower ends of the rods 61R, ML. The extension "a of the universal bar HR presses lightly against the lower end of the rod 61L while the extension for the universal bar 14L presses against the end of the rod HR. The universal bar M has secured to it a crossbar "b which extends on each side to overlap the universal bars "R, "L respectively.

It is clear from the foregoing that when the front ends of the universal bars "R, "L are depressed, the rods 61L, 51R will beraised respectively. When the universal bar 14M, however, is operated both the universal bars 14R, 14L will be actuated and raise both rods 61R, 61L simultaneously.

The universal bar MM is associated with a small group of type bars 21 (Fig. 2) located at the center of the segment which make small an les with the platen, while the universal bars HR, "L 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 "L is associated, is actuated, the extension Ha of the universal bar 14L will raise the rod 61R and thereby will raise the righthand aligning element 69R (Figs. 3 and 6), this action taking place concomitantly withthe 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 210 will strike the cam surface 69b of the lug 10R on aligning element 69R and be guided into cooperation with the vertical flat lefthand edge 590 of the lug 10R. as in Fig. 6, which, in turn, will force the type element 21c, to travel rearwardly or straight upwardly in said figure 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 HR 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 impression.

When any type bar associated with the middle universal bar MM is operated, both universal bars "R, "L will be actuated along with the universal bar HM and will raise both type guide elements R, 681- and lugs 10R, 10L, 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 10R, 10L which, by engagement with the type elements, force them to travel in a direction normal to the platen in effecting an impression. In the case of the type bars associated with the universal bar 14M there is relatively little tendency for the type elements to slide in effecting 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 "R, "L, which function under these conditions in much the same eneral fashion as in a conventional type guide in which the guide 1118s are fixed relative to each other and to the type basket.

The main advantage of this construction is that a very complexly milled type guide element, such as has been used in present commercial noiseless machines is avoided. Such fixed elements are very difllcult to manufacture and expensive since the fixed guiding surfaces must be designed to accommodate a minimum of twenty-one difierent angles of approach of the type bars. Furthermore, when such fixed 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 shown 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 departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. In a typewriting machine having a series of type bars having a fan-shaped disposition symmetrically with respect to a plane passing through the printing point and normal to the surface receiving imprints whereby certain of the type bars strike at varying acute angles to such surface and others strike normally or closely approximating normal, a pair of normally retracted type aligning members located below and on opposite sides of said printing point, and a plurality universal bars for selectively raising said members when a type bar is operated and arranged to raise into type bar engaging position only the aligning member on the opposite side of said plane to the operated type bar when an acutely striking type bar is operated and to raise both aligning members when a normally or approximately normal type bar is operated, said aligning members guiding the acutely striking type bars normally of the platen and jointly preventing lateral vibration of the normally or approximately normally striking type bars.

2. In a typewriting machine having a series of type bars disposed fan-shaped and actuable to a common printing point and striking the print receiving surface with varying angles varying from the normal to materially less than a right angle, said type bars being divided into two main groups symmetrically disposed on each side of the printing point and comprising all of the type bars which strike with angles materially less than a right angle and including a central group comprising the type bars which strike at angles not materially less than a right angle;

vertically slidable type aligning members, one for each of said main groups, disposed below and on the opposite side of the printing point to the related main group of type bars; means whereby the operation of a type bar in either of said main groups raises into type aligning position the corresponding aligning member, and means whereby the operation of a type bar in the central group raises both aligning members into type aligning position.

3. In a typewriting machine, a series of type bars selectively actuable from diiferent positions to strike at the printing point with variant angles of approach, a pair of type aligning members normally disposed below the printing point and means selectively operated simultaneously with the approach of type bars to-the printing point to raise one or both of the aligning members to type aligning position according to the angle of approach of the selected type bar, said aligning members being operative to force the types to strike at the printing point along a fixed path irrespective of the angle of approach of the type bars.

RICHARD vou REPPERT.

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