US3513958A - Typewriter character adding attachment - Google Patents

Description

May 26, 1970 L. LICHTENSTEIN 3,513,958

TYPEWRITER CHARACTER ADDING ATTACHMENT Filed March 7, 1968 4 Sheets-Sheet l 4 FIG. 2

Xi fi ial"; I a I go) I x INVENTOR LEO LICHTENSTE! N BY Ed% AGENT y 1970 L. LICHTENSTEIN 3,513,958

TYPEWRITER CHARACTER ADDING ATTACHMENT Filed March 7, 1968 4 Sheets-Sheet 2 INVENTOR LEO LICHTENSTEIN AGENT May 26, 1970 1.. LICHTENSTEIN TYPEWRITER CHARACTER ADDING ATTACHMENT Filed March 7, 1968 4 Sheets-Sheet 5 INVENTOR LEO LICHTENSTEIN AGENT May 26, 1970 L. LICHTENSTEIN 3,513,958

TYPEWRI'I'ER CHARACTER ADDING ATTACHMENT Filed March 7. 1968 4 Sheets-Sheet 4.

INVENTOR LEO LICHTENSTEIN BY 5" 14 A AGENT United States Patent Office 3,513,958. Patented May 26, 1970 3,513,958 TYPEWRITER CHARACTER ADDING ATTACHlVIENT Leo Lichtenstein, Hicksville, N.Y., assignor of fifty percent to Frank Blaha, Jamaica, NY. Filed Mar. 7, 1968, Ser. No. 711,277 Int. Cl. B41j 25/20, 29/00 US. Cl. 197-480 18 Claims ABSTRACT OF THE DISCLOSURE Typewriter attachment permitting rapid selection of a plurality of additional characters and insertion in typewritten text produced with a typewriter fitted with the attachment. It has a set of typebars similar to those of the parent typewriter, held by a support in substantially vertical relation to the plane in which the typewriter segment moves. The attachment typebars have arcuately aligned pivot points converging toward a printing point which is common with that of the conventional typebars in the typewriter segment.

The attachment may have means to cause a selected attachment typebar to strike the platen, and may also be provided with manually or automatically operable means to return the selected typebar to its inoperative position. Optionally, a small arm may be provided on the typebar guide for spacing the selected attachment typebar a small distance away from the ribbon guide until the striking means is actuated.

The invention relates to typewriter attachments, and more particularly to an attachment removably connected to the typewriter so as to at least double the character capacity of the same, for typing a wide variety of auxiliary or special characters.

In the use of typewriters there frequently arises the necessity to insert different special characters such as letters, symbols, signs, etc., in the typewritten matter, where such characters are not available as part of the typewriters in question. This is especially true in typing of materials in scientific and technical fields where characters of foreign alphabets (e.g. the Greek), electrical and scientific symbols, etc., are not infrequently used.

For duplicating such texts, e.g. by the offset printing method, it is imperative that the special characters be inserted in a neat fashion and not by hand which would produce an irregular appearance. The installation of special keys would prove impractical, and the standard typewriters do not have room for more than one or two installed auxiliary keys and typebars.

It has been proposed in the prior art to use a character holder by which a selected special character can be held in front of the typebar guide, to be hit by one of the regular typewriter typebars. The selection is of course a tedious job; the special characters may become lost or misplaced; and the end result is still not satisfactory because the alignment is difficult if not impossible, particularly with unusual symbols having different sizes and/or irregular outlines as compared to standard typewriter characters.

Another proposal relates to a small device which can be clipped onto the typewriter and has its own auxiliary key. Operation of this device has been found cumbersome and rather limited in terms of the number of special characters that can be produced.

The prior art has also proposed a rather bulky and cumbersome attachment including a basket-shaped housing held by a separate pedestal which is horizontally and vertically adjustable behind the typewriter. An arcuate arm carries the basket-shaped housing in a position somewhat above the typewriter platen. A limited number, e.g. l6, typebars are pivotally held in the housing, and can be actuated to hang down so as to allow a character thereon to be printed onto the paper held on the platen.

For switching between two rows of characters provided on the typebars of the attachment, either the pedestal has to be raised and lowered, or the typewriter has to be of the type wherein the carriage is vertically reciprocable. Otherwise only one character could be provided on each auxiliary typebar.

There are numerous disadvantages of this kind of structure, as will be readily appreciated: the number of typebars and/or characters is limited, the resilience of the pedestal and also the swinging movement of the typebars creates problems in obtaining an accurate alignment of the added character with the typewritten text; carriage-shift typewriters are commercially obsolete by now; smudged or misaligned printing is the result with this earlier attachment.

It is also known to provide tandem typewriters where a common carriage and platen can travel above two interconnected typewriter systems, one having the regular and the other the auxiliary or special characters on its keyboard and typebars. It goes without saying that it is very tedious and sometimes diflicult to shift back and forth, sometimes for a single special character, between the two typewriter systems. If they are equipped with modern proportional spacing, it is very difiicult to provide proper correlation between the typing produced on the tandem machine. The typing with the tandem typewriters is a very slow process. Eventually, the typist becomes irritated and the end result is a poor and objectionable typing.

It is the object of the present invention to provide an attachment which can be secured to and disengaged from standard typewriters, without interfering with their normal operation, or materially obstructing the viewability of the typewritten matter.

The inventive typewriter attachment is easy to manufacture, to install and to maintain.

It is also the object of the invention to provide an attachment which substantially increases the number of characters in a typewriter, such as doubling their number (that is, from the usual 82-88 characters to about 176), Without any spatial or operational disadvantages.

It is yet an important object of the invention to have all auxiliary or special characters of a basic set right in front of the typist, without the danger of misplacing or confusing them, and also to provide clear and properly aligned impressions in the typewritten text.

It is a further object to the invention to provide at least one of the auxiliary typebars so that it can be removed from the attachment and interchanged with any of a number of further special-character typebars, thus further increasing the typing capacity of the typewriter to which the inventive attachment is fitted.

Finally it is also an object of the invention to provide coupling mechanism for sequentially operating two typebars of the typewriter, upon actuation of only one key lever, for correlating the printing and the clearing of the selected typebars. Alternatively, this expedient can also serve in a regular typewriter for printing slogans, trade names, or the like which are provided on two typebars and are always used in the same order.

According to one of the important features of the invention, the typewriter attachment comprises a set of typebars with characters additional to those of the regular typebars of the parent typewriter, and support means for the attachment typebars, removably connected to the typewriter in substantially vertical relation to the plane in which the segment is movable. The attachment typebars are pivotally held in the support means with arcuately aligned pivot points.

It has been found preferable to make the attachment typebars converge toward a common striking or printing point of the regular typebars of the parent typewriter.

The inventive typewriter attachment constitutes means for increasing the capacity of the parent typewriter to which it is attached. It is particularly adapted for poweroperated or electrically driven typewriters wherein the segment carrying the typebars is vertically movable while the carriage and platen are only lengthwise displaceable. The inventive attachment is however adapted for use with typewriters wherein the carriage is vertically reciprocable while the segment is stationary.

According to inventive features, the typebars of the attachment are manually movable between an upper position, to be called hereinafter the inoperative position, and a lower position to be referred to as the operative position. Means are provided to cause a selected attachment typebar to strike the platen after having been moved to the operative position.

Another important optional feature relates to the provision of mechanical means for returning the selected type-bar to its inoperative position, instead of manually flipping it back. The afore-mentioned striking means and the optional returning means are preferably provided by slightly modified keys and typebars of the parent typewriter, with their associated actuating mechanisms. The two operations may be automatically coupled with one another.

It is yet another feature of the invention that the attachment can be permanently mounted to a typewriter but can nevertheless be removed therefrom, for the ease of transportation of either the parent typewriter or the attachment proper.

It is a further feature of the inventive attachment that at least one of the additional typebars, preferably in the center of the arcuate arrangement, is removable and interchangeable with any number of separately stored similar typebars, thereby providing an added chance of unlimited character variations.

The attachment according to the invention can be easily fastened to and disconnected from the typewriter. When attached, the inventive device, together with the parent typewriter, constitutes a complete, integrated typewriter system with a total capacity of, say, 170 characters of which the 88 characters of the attachment may be tailored to or selected according to the individual users needs. There is also the added facility of substituting any number of further typebars, for a particular typebar.

The typing operation of the inventive typewriter attachment, when mechanically integrated with the parent typewriter, is extremely simple. The act of registering a selected attachment typebar (i.e. setting the selected one in front of the common printing point, slightly above the typebar guide of the parent typewriter) is under fingertip control of the typist or operator. Subsequently, the printing of the character in question is under key-touch control, by way of one of the keys of the typewriter, as is also the clearing of any registered typebar of the attachment if a different selection is desired prior to impres- The return of the selected typebar to its inoperative or rest position, subsequent to key-touch printing or clearing, may be automatic, as will be described in full detail as the specification proceeds.

The inventive typewriter attachment does not require additional carriage setting or resetting, as is necessary with the afore-mentioned tandem typewriters, since the striking or printing point of the additional or attachment typebars is precisely the same as for the conventional typebars of the parent typewriter. The inventive attachment does not of course require any key changing or key insertion in the original complement of typebars of the parent typewriter in order to have a plurality of additional characters.

It is yet another feature of the invention that it also provides a coupling attachment for typewriters, for sequentially operating two or possibly more typebars upon actuation of only one key lever, simulating the manual actuation of a particular key lever upon completion of the action of a previously actuated other lever mechanism which is coupled thereto.

Other objects, features and many of the attendant advantages of the invention will 'be readily appreciated as the same becomes better understood by reference to the following detailed description, when considered with the accompanying drawings, wherein FIG. 1 is a somewhat schematic side view of a conventional typewriter, with the inventive attachment mounted thereto;

. FIG. 2 is a front elevation of the basic elements of the attachment, together with portions of the typewriter to which it is mounted, and viewed in the direction of he arrow in FIG. 1;

FIG. 3 is an enlarged partial view of FIG. 2, showing the typebar guide of the parent typewriter together with an optional spacing arm forming part of the inventive attachment;

FIG. 4a is a vertical sectional view, through the at tachment and parts of the typewriter, constituting the up per part of a section taken along line 44 in FIG. 2;

FIG. 4b is another vertical sectional view, through parts of the typewriter mechanism only, constituting the lower part of the section 4-4 of FIG. 2;

FIG. 40 is a sectional view similar to that of FIG. 4b but showing additional parts of the typewriter for illustration of the inventive coupling attachment;

FIG. 5 is a vertical sectional view corresponding to a portion of FIG. 4a, with certain parts in a different position, and also showing the spacing arm of FIG. 3;

FIG. 6 is another vertical sectional view, similar to that of FIG. 5, but showing one of the attachment typebars removed for substitution by any of a number of further auxiliary typebars; and

FIG. 7 is a plan view of the coupling attachment between two adjoining key levers of the typewriter, taken along line 7--7 of FIG. 4b.

In the following, the inventive typewriter attachment will be described in detail, and occasionally reference will be made to parts of the associated or parent typewriter without, however, describing them in full detail since it is believed they will all be well known to those skilled in the art.

The typewriter, generally shown in FIG. 1, is designated by numeral 1. It has a conventional carriage 2 with a cylinder or platen 3 mounted therein. FIG. 2 also shows a segment support 4, a segment 5 with conventional typebars 6 therein, as well as a typebar guide 7. In FIG. 2, two of the typebars are identified by numerals 6a and 6b (also shown in FIG. 4a) which will be described in connection with other features of the inventive attachment as the description proceeds. A conventional ribbon guide and lift arm is identified by numeral 8. A power roller is shown at 9 in FIGS. 4b and 40.

Other operative parts of the typewriter will be described as the description proceeds, including usual transversal rods or wires for respectively mounting of the typebars 6, of operating cam levers as well as of key levers, identified respectively by numerals 5a, 9a and 9b. The keyboard of the typewriter 1 schematically shown in FIG. 1 includes two identified keys, namely 41 and 51, and some of the elements of the actuating mechanisms (such as parts 42, 45, 46) which will all be described in detail as the description proceeds.

Before installing the inventive attachment to a typewriter, two properly spaced holes, shown in FIG. 2 at 4, have to be drilled and tapped in the segment support 4. Into these holes are threaded two posts 10 of the attachment, which constitute parts of support means for the latter with respect to the typewriter.

It will be understood that other conventional means may be provided for securing the inventive attachment, e.g. to other parts of the parent typewriter. Thus, as a matter of example, support means may be provided by extending the motion bolts forming part of the segment support structure of the typewriter, instead of drilling and inserting the afore-mentioned posts.

The connection of posts to segment support 4 is an example of applying the inventive attachment to a typewriter having shift action through a reciprocable segment. For a typewriter having a carriage and platen movable with respect to non-reciprocable typebars, the support means may include one or more members held by stationary portions of the typewriter, such as its frame or other suitable structural parts.

A bracket 12 is connected, for example by way of nuts and interposed spacing elements, to the posts 10 so as to hold the attachment, as shown in FIG. 2. Bent support wires 14 are also attached to the posts, preferably above the brackets 12, for purposes to be explained somewhat later.

A segment forms an important part of the inventive attachment, with a plurality of slots therein, for pivotally holding a corresponding number of typebars 16. A centrally disposed attachment typebar is designated 16a and will be described later as an optional alternative. The segment 15 is secured to the bracket 12 in a conventional manner, as shown in FIG. 5.

Each typebar 16, 16a accommodates two special characters, in any desired combination, subject to size restrictions only. Although FIG. 2 shows a full set of typebars 16 in segment 15, in a manner and number similar to those of the typebars 6 in segment 5 of the parent typewriter (some of the typebars have been omitted from the illustration for the sake of clarity). It will be understood that a smaller or even larger number of slots may be provided in the attachment segment 15, with a correspondingly smaller or larger number of typebars 16, 16a.

The geometric extensions of the slots in segment 15 converge, as can be seen from FIG. 2, at a common printing point which coincides with the point at which the characters on the typebars 6 of the typewriter proper face the platen 3 and the paper thereon. It can be seen in FIG. 2 and particularly in FIGS. 4a and 5 that the typebars 16, 16:: have extensions 16' at their remote ends which are adapted to fit into the conventional slot of the typebar guide 7 when these typebars are in their flipped-down, operative positions.

It will be understood that the typebars 16, 16a have the extensions 16' at a point beyond the characters applied thereto, if counting from the pivot points within the segment 15; at the same the conventional typebars 6 are adapted to engage the same guide 7 w1th portions just below their respective characters, closer to their pivot points in the segment 5. This assures proper fit of the attachment typebars 16, 16a in the guide 7, and proper operation of the key-shift lever (not shown) which consequently acts on both kinds of typebars (6 and 16, respectively) in the same manner, such as to shift from lower case to upper case or capital letters; or from one kind of special character to another, as provided in the respective inner and outer rows, as shown in FIG. 2, above the outer ends of the typebars 16, 16a, just below the extensions 16.

With the preferred, exemplary support means as illustrated in FIGS. 1, 2 and 4a, the attachment segment 15 is coordinated in its up-and-down movement with that of the typewriter segment 5 so as to follow the shift action, as required. If the inventive attachment is held by a stationary portion of the typewriter frame (not illustrated in detail), in case of a parent typewriter with a non-movable segment structure but vertically reciprocable carriage for shift action, the result will be the same insofar as the platen changes its position with respect to both the regular and the additional characters, providing again reliable shift action for both kinds of typebars and characters.

A back-up plate 18, preferably made from plastic or other light material, is arcuately shaped and held by the afore-mentioned support wires 14. The outer portion of the plate 18 may serve as a base for the visual identification of the typebars 16 and the characters thereon, by indicia applied to the plate 18, as shown for some of the typebars 16, 16a in the upper region of FIG. 2. Since the posts 10 and the attachment proper held there-by are at a slight inclination from the vertical, forming an angle past the perpendicular, away from the typist, the indicia applied to the plate 18 are easily legible. It should be noted that the inclination of the plate 18, and the typebars 16, 16a thereon, as schematically but not precisely shown in FIG. 1, may be identical with or different from the slanting plane of movement of the typewriter segment 5, and may assume values up to about 25 degrees.

A permanent-magnet strip 20, preferably of the rubberembedded or plastic type, is applied to the plate 18 underneath the ends of the typebars 16, 1611, just below the characters, so as to hold the typebars in place when flipped up into their upper or inoperative positions. The backward tilt of the plate 18, if any, provides stable equilibrium for the typebars, in addition to the magnetic holding action.

The typewriter attachment also comprises elements for an automatically activated typebar return assembly, including a bent, preferably U-shaped member or bar 22 substantially above the typebar guide 7 and in front of the segment 15, a 'U-bar extension 24 secured to the bent member or U-bar 22, two brackets 26 attached to the bracket 12 and the segment 15, and through which the members 22, 24 pass in a pivotable manner, as well as a retaining spring 28.

The latter is provided to return the U-bar 22 toward the segment 15 once it has been actuated.

The operation of this assembly will be explained somewhat later, in its role for returning the selected typebars 16, 16a both after printing and before (e.g. if it has been selected and registered before the typebar guide 7 erroneously, and should be returned to its inoperative or rest position).

FIG. 3 shows, on an enlarged scale, a mechanism for spacing away the registered typebars 16, 16a a distance away from the typewriter ribbon, passing through and vertically reciprocated by the guide and lift arm 8 mentioned before. The mechanism, also appearing on a smaller scale in FIG. 2, and in a side view in FIG. 5, includes a pivotable arm 30 attached to a stationary portion of the typewriter, having an upper limb 30a substantially above the slot of the typebar guide 7, and a lower limb 30b having a pin-shaped protrusion in the area of the cut-out in the ribbon guide arm 8, as clearly shown in FIG. 3. A spring 32 biases the mechanism so as to make the protrusion at 30b contact the edge of the guide-arm cut-out.

When a typebar 16 or 16a is brought into its operative position, in front of guide 7, its end portion contacts the arm portion 30a, as clearly shown in FIG. 5, while the extension 16' partly enters the slot in guide 7. When the impression or printing mechanism is actuated, as will be explained later, the ribbon mechanism of the typewriter is actuated, together with the carriage, in the conventional manner, whereby the arm 8 is raised together with the ribbon passing therethrough, the inventive spacing arm 30 is pivoted in counter-clockwise direction, as seen in FIG. 3 and thus the portion 30a clears the selected typebar, after the ribbon has been raised between the typebar and the platen.

Owing to this arrangement, the attachment typebar cannot interfere with the vertical ribbon movement despite its registered position at the typebar guide 7. When the lift arm 8 descends, spring 32 makes the pin at 3017 follow the cut-out, and the spacing arm portion 30a will again assume its position above the typebar guide slot, as illustrated.

It has been mentioned before that a special attachment typebar 16a is shown in the center of the segment 15 in FIG. 2, and of course also in FIGS. 4a, 5 and 6 which are taken along the section line 44 of FIG. 2. One or perhaps two typebars are provided in this fashion, and have special features allowing removal of the typebar 16a for interchangeability with a set of similar, separately stored typebars, thereby further expanding the characte typing capacity of the attachment.

The attachment segment 15 has a wire 34 passing through the pivot points of typebars 16, 16a (similar to the wire 5a of the typewriter segment 5 for the regular typebars 6, 6a, 6b), best shown in FIG. 4a. The typebar 16a has a composite, substantially axial slot therein with an angular outside portion 36, a somewhat rounded portion 36a having a diameter just about the same as that of the wire 34, and an elongated portion 36b, as shown in FIG. 6.

The resilience of the typebar portions on either side of the axial slot allows ready removal from and re-in sertion to the holding wire, as will be clear when comparing FIGS. 5 and 6 of the drawing. Thus, the typebar(s) 1611 can be individually replaced by other typebars with characters which may not be available in the complement of typebars 16.

It will be understood that the back-up plate 18' may have a removable index section just above the special typebar(s) 16a, allowing the respective indicia to be exchanged or altered, if necessary, for identification of the particular special characters which have been inserted.

In addition to the above-described basic and optional component parts of the typewriter attachment, the combination also comprises the following operational devices:

(A) An impression or printing bar 40, preferably provided by modifying one of the typebars of the parent typewriter. In the exemplary embodiment, it will be seen from FIG. 2 that the typebar 6a carries the printing bar 40 in the form of a wire loop (also shown edgewise in FIG. 4a), which is made from a relatively hard but resilient wire material. There are various ways in which the wire loop 40 can be secured to the body of the typebar 6a. As a matter of example, a sleeve is shown at the outer end of the bar, and the loop is frictionally held between the typebar and the sleeve; appropriate welding or soldering may be applied. The length of the loop allows it to hit upon the shank of the typebars 16, 16a, when in their operative or flipped-down position, rather than on their characters or terminal portions.

The typebar 6a is preferably at the penultimate position at the right-hand side of the typewriter keyboard and of the segment '5. The respective typewriter key 41 will be described in its operative function when dealing with the respective actuating mechanism which is similar for the aforementioned impression bar and for another special bar to be described hereafter.

(B) A clearing or return bar 50 which is similarly provided by modifying one of the typebars of the typewriter, namely preferably the last one on the right-hand side of the segment 5, identified by numeral 6b. This typebar is actuated by the key 51. The bar 50 is preferably in the form of a resilient block and is disposed so as to impinge upon the U-bar extension 24, thereby pivoting the same in clockwise direction, if viewed from the free end of the extension 24, whereby the U-bar 22 is entrained, imparting a sudden jolt to the selected typebar 16, 16a as the case may be, which will thus flip back, in upward direction, to its rest position on plate 18. Spring 28 returns the members 22 and 24 to their initial positions.

(C) The third operational device is constituted by a coupling attachment, generally designated by numeral 60, which is disposed between two key levers 42, 52, and their actuating mechanisms, respectively associated with the keys 41, 51, as shown in FIGS. 4b, 4c and 7.

In the following, the structure of both actuating mechanisms will be described for the bars 40, 50 and their respective keys 41, 51 and typebars 6a, 6b. It will be understood that the mechanism is identical for both systems, is part of the parent typewriter and not of the inventive attachment, and would not require description except for the provision of the coupling attachment 60 which, as will be explained later, interconnects the mechanisms of bars 40, '50 for automatic, sequential operation.

Reference will be made primarily to FIGS. 4b, 4c and 7 of the drawings, wherein the lower portion of the section line 4-4 of FIG. 2 is illustrated. As shown, the keys 41, 51 are disposed on respective key levers 42, 52 which are both pivoted at their inner ends on the earlier-mentioned wire or rod 9b. The levers 42, 52 have extensions adapted to bear down, upon actuation of the respective keys, on laterally extending portions 43a, 53a of actuators or cam latches 43, 53 which are forwardly spring biased on cam levers 45, 55 with which they are pivotable about the wire or rod 9a, common for all actuating mechanisms, as is the aforementioned wire or rod 9b.

The cam latches 43, 53 have front end portions 43b, 53b to which reference will be made somewhat later. In a known manner, the cam latches can be slid backwards, once the respective mechanism has been actuated for making an impression by way of the cam lever 45, 55, its associated linkage 46, '56 and the typebar 6 (6a, 6b) connected thereto, as shown in FIG. 4a. The sliding action prevents repeated actuation of the mechanism by way of the key 41, 51, until the same has been let go by the typist, for making another impression (which may be by the same mechanism or another one, as the case may be).

The cam levers 45, 55 pivotally hold respective cams 44, 54 which are acted upon by the keys 41, 51 when depressed, by way of the aforedescribed elements 42 and 43a, as well as 52 and 53a, whereupon the earns 44, 54 contact the typewriter power roller 9 which rotates in the direction shown by the arrow, and thus entrains the actuated cam far enough to make the cam pivot the cam lever 45 or 55, initiating thereby the above-described typebar actuating train.

At the same time, the front portions 43b, 53b of the cam latches clear the extensions of the key levers 42, 52 if they should still be in a depressed condition. All this is, of course, part of the regular typewriter mechanism at least in representative structures having the described cam and lever action.

In FIGS. 4b and 4c, conventional biasing springs are shown, e.g. for the cam latches 43, 53, between the cams 44, 54 and the cam levers 45, 55, as well as for the latter (omitted in FIG. 4b), for urging the same into the full-line position shown in FIG. 4a. The broken-line position is the operated position in which the typebar is made to move toward the platen, as illustrated for the printing bar 40. The springs are conventional and need not be identified by numerals or described in more detail.

In the above-explained manner, key 41 will make the typebar 6a to operate, and bar 40 strike the shank of a selected attachment typebar 16 or 16a, by way of the interconnected, above-described mechanism. In a similar manner, operation of key 51 will actuate bar 50 which strikes the U-bar extension 24. The typist has thus control over both operational devices, as described earlier in sections A and B.

Now we come to the third device, the coupling attachment 60, interposed between the actuating mechanisms of the just described bars 40 and 50, in the following manner. The afore-mentioned FIGS. 4b, 4c and 7 show a coupling arm 62 held by the wire or rod 9b, and having a laterally protruding portion 62a through which is guided in a freely movable manner, the upper hooked end of a connecting link or wire 64, the lower end of the latter being hooked into an appropriate bore in the cam lever 45.

The arm 62 is positioned on the wire 9b intermediate the key levers 42 and 52, as shown in FIG. 7. Preferably,

an eccentric bushing 68 is provided for positioning the arm 62 on the wire 9b, allowing precise adjustment of the arm with respect to the cooperating elements, namely the aforementioned cam lever 45 and the cam latch 53 to which more reference will be had hereunder, as the operation of the coupling attachment is explained.

A spring 66 is secured to a stationary frame portion of the the typewriter for biasing the arm 62 in upward direction, in continuous contact with the bent upper end of the connecting link 64. In FIG. 7 the spring passes upwardly beyond the plane of the drawing. It can be seen from the same FIG. 7 that the portion 62a protrudes from the arm 62 in one direction (downwardly in the illustration) while the forward end of the arm has thereon a roller or similar bearing surface 62, adapted to engage from the front end portion 53b of the cam latch 53.

It will be clear from the above description that actuation of the system 41 45 (of the first or printing mechanism which ends in bar 40) is transferred by way of the coupling members 64 and 62 to the second or clearing mechanism, which ends in bar 50, by way of its actuator or cam latch 53. Thus, manual actuation of the key lever 52 is simulated upon completion of the action of the first mechanism.

It will be understood by those skilled in the art that the described coupling attachment or mechanism is equally adapted to the above-described operations and to use in typewriters which are not equipped with inventive typebar complement, e.g. for printing two or more characters or character combinations as a result of actuating a single key of the keyboard.

To effect an impression of any special character of the additional complement of typebars 16, 16a provided by the inventive attachment, the typist merely registers the appropriate typebar by a flick of the finger, bringing the same from the upward or inoperative position (resting on plate 18) to the downward or operative position; subsequently the typist depresses the impression key 41 on the keyboard of the typewriter.

As has been explained in detail, the return of the typebar 16, 16a to the rest position may occur automatically, subsequent to the impression or printing of the desired character. To clear any typebar prior to impression the typist merely depresses the clearing or return key 51 instead of the impression key 41 of the keyboard.

The sequence of mechanical operations that actually occur during the above-mentioned operations are as follows:

(1) The selected typebar 16, 16a registers in a position about /2" away from the point of impression, in front of the guide 7. If the spacing arm 30 is provided, its limb portion 30a provides a proper spacing so as to avoid interference with the ascending ribbon. At this point either an impression of the desired character or a clearing of the registered typebar may be effected by depressing the respective key 41 or 51, as has been explained before.

(2) If the impression key 41 is depressed, the bar 40 is activated via the associated mechanism, as shown in FIGS. 4b, 4c and 7, in the same manner as any typebar 6 of the parent typewriter is activated.

(3) The bar 40 in motion lifts the ribbon by way of the guide and lift arm 8, and spaces the carriage 2 of the typewriter, just as in the typing sequence of any typebar 6 of the typewriter, in a well-known and conventional manner. At the same time, the cut-out of arm 8 lifts the protrusion 30b, arm 30 pivots away from the guide 7, and thus allows the character of the selected typebar 16 or 16a to approach the ribbon which has in the meantime been lifted at least to the level of the character to be printed.

(4) The impression bar 40 with its wire loop strikes the registered typebar 16 or 16a which then effects an impression of the desired character.

The returning impression bar 40 and its mechanism activates the clearing bar 50 automatically by means of the coupling attachment 60 between the respective actuating mechanisms of the systems 40 and 50.

(6) The clearing bar 50 strikes the U-bar extension 24, causing the U-bar 22 to flip the registered typebar to its rest position.

(7) Clearing of the registered typebar may also be effected following step (1), if the clearing key 51 is depressed instead of the impression key 41, as described in step (2).

Depression of the clear key 51 is equivalent to the activation of the bar 50, as described in step (5), and causes the same return action as described in step (6).

It should be understood, of course, that the foregoing disclosure relates only to a preferred exemplary embodiment of the inventive typewriter attachment, and that it is intended to cover all changes and modifications of the example described which do not constitute departures from the spirit and scope of the invention as set forth in the appended claims.

What I claim is:

1. An attachment for typewriters for adding thereto a set of additional characters, the typewriter having a lengthwise movable carriage and a platen rotatably mounted thereon; first segment means, and a first set of typebars pivotally carried by said first segment means and having a first set of characters mounted thereon; a typebar guide secured to said first segment means and extending upwardly from the latter to define a printing point adjacent said platen andto guide said typebars to said printing point; the attachment comprising, in combination, a second set of typebars carrying a second set of characters not included in said first set of characters; support means removably connected to the typewriter in a fixed position with respect to said first segment means, typebars of said second set being pivotally carried by said support means with the pivot points thereof being arranged in an arc so that said typebars of the second set converge toward and print at said printing point; said typebars of the second set being manually movable, from an inoperative position in which they extend upwardly from their respective pivot points, to an operative position in which they extend downwardly from said pivot points, with their respective characters being positioned adjacent said printing point and a portion of said typebars positioned in said typebar guide; and keyboard operated means to move a selected typebar of said second set to strike said platen for making an impression at said printing point after it has first been manually moved from said inoperative position to said operative position.

2. The typewriter attachment as defined in claim 1, wherein the typewriter is further equipped with ribbon guide and lift means, the attachment further comprising means for spacing said selected typebar of the second set a small distance away from said ribbon guide means at least until said striking means is actuated.

3. The typewriter attachment as defined in claim 2, wherein said spacing means includes an arm pivotally attached to the typewriter and having a first portion contacting said ribbon guide means so as to be pivoted thereby when it is actuated by the typewriter mechanism, as well as a second portion in front of said printing point and in the area of said typebar guide, said second portion constituting a temporary arrestment for said selected typebar of the second set to avoid its contact with the ribbon during the actuation of said ribbon guide and lift means.

4. The typewriter attachment as defined in claim 1, wherein said support means includes an arcuate resting surface for said typebars of the second set, said surface being tilted from the vertical, in a direction away from said typebars of the second set, so as to allow the latter to rest on said surface by gravity in said inoperative position.

5. The typewriter attachment as defined in claim 1, wherein said support means includes a back-up plate for said typebars of the second set, and having thereon indicia for identifying said characters of the attachment typebars.

6. The typewriter attachment as defined in claim 1, wherein said support means includes magnetic retaining means for temporarily holding said typebars of the second set in said inoperative positions.

7. The typewriter attachment as defined in claim 1, wherein said typebars of the second set have extensions at their remote ends, beyond the respective characters, for sliding engagement with said typebar guide when in their operative positions, whereby said typebars of the second set are guided into proper striking position with respect to said platen.

8. The typewriter attachment as defined in claim 1, wherein said support means includes second segment means for said typebars of the second set, two posts threadedly engaging portions of said first segment means, and a bracket interposed between said posts for holding said second segment means therebetween.

9. The typewriter attachment as defined in claim 1, wherein said support means includes second segment means for said typebars of the second set, including a wire passing through said pivot points of the typebars of the second set, at least one of said typebars of the second set being slotted so as to be removable from said wire and interchangeable with similar slotted typebars having different characters thereon, for further increasing the typing capacity of the typewriter.

10. The typewriter attachment as defined in claim '1, wherein the typewriter carriage is vertically reciprocable while said first segment means is stationary, said support means including at least one support member connected to a stationary portion of the typewriter.

11. The typewriter attachment as defined in claim 1, wherein said striking means includes a resilient wire loop secured to the end of one of said typebars of the first set for hitting the shank of said selected typebar of the second set intermedaite the respective character and pivot point thereof.

12. The typewriter attachment as defined in claim 1, further comprising means to return said selected typebar of the second set typebar from said operative to said inoperative position.

13. The typewriter attachment as defined in claim 12, wherein said returning means includes a bent member pivotally supported in the area between said printing point and said pivot points of the typebars of the second set, said bent member being adapted to contact any one of said typebars of the second set when in its operative position, and an extension connected to said bent member, said extension being adapted to be acted upon by extraneous means to pivot said bent member, whereby said selected typebar of the second set in its operative position is imparted a pivotal movement so as to return to its inoperative position.

14. The typewriter attachment as defined in claim 13, wherein said extraneous means includes a resilient hammer secured to the end of another one of said typebars of the 12 first set for hitting said extension and thereby initiating said return of the selected typebar of the second set to its inoperative position.

15. The typewriter attachment as defined in claim 14, wherein said striking means includes a resilient wire loop secured to the end of one of said typebars of the first set for hitting the shank of said selected typebar of the second set, prior to the operation of said returning means.

16. The typewriter attachment as defined in claim 15, further comprising coupling means between said one and said other typebar of the first set, for sequential operation of said returning means upon completion of the operation of said striking means, whereby the operator of the typewriter only has to initiate operation of said striking means for obtaining, first, printing of the character of said selected typebar of the second set and, subsequently, said return thereof to its inoperative position.

17. The typewriter attachment as defined in claim 16, wherein the typewriter is further equipped with respective first and second actuating mechanisms for said one and said other typebars of the first set, each mechanism including a manually operable key lever, a pivotable cam, actuators linking said cam to said key lever, and a cam lever actuated by said cam for moving the associated typebars of said first set to their operative positions, with a common power roller acting on said cams, said coupling means including connecting means between the cam lever of said first mechanism and the actuators of said second mechanism, for actuation of the latter immediately upon completion of the action of said first mechanism.

18. The typewriter attachment as defined in claim 17, wherein the typewriter is further equipped with a support wire passing through the pivot points of all key levers, including those of said actuating mechanisms, said connecting means including an arm pivoted on said support wire, a link between said cam lever of the first mechanism and said arm, and means for biasing said arm away from said link, said arm having a portion adapted to engage one of said actuators of said second mechanism, whereby manual actuation of the key lever of said second mechanism is simulated upon said completion of the action of the first mechanism.

References Cited UNITED STATES PATENTS 2,138,151 11/1938 Going 1975 2,305,763 12/1942 Dietrich 197--l80 XR 2,666,515 1/1954 Brumhill et a1 197-5 2,717,686 9/1955 Seeber 1977 2,850,136 9/1958 Seeber et a1. 1977 3,063,541 11/1962 Hartnett et al 197180 3,289,804 12/1966 Schaeifer' 1977 3,349,889 10/1967 Barger 197-180 EDGAR S. BURR, Primary Examiner US. Cl. X.-R. 1977 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. v [915 i Dated y 6, 1970 gqg Leo Lichtenstein It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 5, two last lines (column 11, lines 2 and 5 in the patentj: change "attachment typebars." to typebars of the second set.

sen-m Anew Edward MJHMQIL WIHIIAM E. W. JR.

I I Qonmissioner of Patents Amman; 0mm

USCOMM-DC DOING-P69 FORM PO-IOSO (10-69) a u 5 GOVERNMENT Pmmmc. orncc I969 o-1us-u4

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