US2843244A - Type lever motion devices for typewriters and similar machines - Google Patents

Description

y 5. 19584 E. NEUMANN- 2,843,244

7 TYPE LEVER-MOTION DEVICES FOR TYIEWRITERS AND SIMILAR MACHINES,

Filed Dec. 5, 1955 =3 Sheets-Sheet 1 f I m B 5 8 r 'Z A Ja e/7:021

v July 15, 1958 "E, NEUMANN $843,244

TYPE LEVER MOTIONDEVICESFOR .TYPEWRITERS AND SIMILAR MACHINES Filed Dec. 5 1955 s Sheets-Sheet 2 lm/emarz' man/12 y 1953 I NEUMANN 2,843,244

TYPE LEVER MOTION DEVICES FOR TYPEWRITERS AND SIMILAR MACHINES Filed Dec. 5, 1955' 3 Sheets-Sheet 3 Inventor .Nawmmw fig United States Patent M TYPE LEVER MUTION DEVICES FOR TYPE- WRITEQRS AND SIMILAR MACHINES Erich Neumann, Bielefeld, Germany Application December 5, 1955, Serial No. 551,133

8 Claims. (Cl. 197-27) This invention relates to a type lever motion device for typewriters and similar machines, in which there is attached pivotall y to each key lever an intermediate lever, the points of attachment of which are coaxial for each row of keys and which coact with a tilting bar for the intermediate levers, which widens towards the sides of the machine, in such a manner that, with the same distance of travel for all key levers, each intermediate lever covers the angular path conforming to the striking path of the associated type lever.

In a known device of this kind the type levers are constructed as two-armed levers which are attached coaxially to the key levers of each row of keys and rest with one arm on a tilting bar forming a constructional unit with the key lever guiding comb member, so that, as the distance from the centre of the machine increases, through a shortening of the effective lever arm. the angular motions of the individual intermediate levers at their free ends become greater. Such an arrangement has the disadvantage, however, that it requires a relatively great amount of space, which works out unfavourably as regards the external dimensions, more particularly in the case of small machines (portable machines). "The great amount of space required is mainly due to the fact, that, through the described construction of the device, with an increase in the distance from the middle of the machine only the arm lying in frontof the points of attachment of the intermediate levers is altered in its effective length. If with such an arrangement it becomes necessary to restrict the space for the intermediate levers (for instance in the case of a portable machine), differences in the downward motions of the keys will result, which considerably impair the good typing properties of the machine. Moreover, the lateral guiding of the intermediate levers in the known arrangement also calls for improvea ment, more particularly since the intermediate levers are held in position only by their jointing means (for instance rivets). i i i i The object of the present invention is to remedy these defects. With this end in view the inventioriconsists substantially in locating the tilting bar, which provides a fulcrum for the intermediate levers, behind the points of attachment of the intermediate levers to the key levers (as viewed from the front of the machine), the change of angle paths of the intermediate levers being brought about by locating the fulcrum nearer to the'keys for the levers towards the sides of the rnachine than for those near themiddle, thus modifying the ratios of the lever arms.

As through the disposition of the tilting bar behind the points of attachment of the intermediate levers the displacement of the tilting points of the intermediatellevers has a very great influence on the angular motion of the intermediate levers and, moreover, the tilting bar can be placed in a relatively low position, the decisive advantage results, that the space required for the type lever motion device is considerablysmaller thanin the known 2,843,24 i Patented July 15, 1958 2 devices. Hence, it is possible even with small machines, more particularly with portable typewriters, to obtain excellent typing qualities, more particularly a uniformly light touch and an even depression of all the keys.

From the economical point of view it is of advantage according to the invention, if the tilting bar be made of a sheet metal strip, bent over several times in the longitudinal direction, and this strip be used at the same time as a support for the key levers, those supports having proved specially suitable, which are formed by slots adapted to the key levers and a spindle extending through these slots.

The intermediate lever tilting points disposed for each intermediate lever at a different place lie, according to a further feature of the invention, on two straight lines starting from the middle of the machine, which, as the distance from the middle of the machine increases get gradually closer to the keys. in many cases it is of advantage, however, to arrange the intermediate lever tilting points in a horizontal plane in arcuate formation in such a manner that the two outermost tilting points lie nearest the keys. The arcuate formation of the tilting points has the advantage, that, with an entirely uniform key depression, the required angular motions of the intermediate levers remain exactly the same in all ranges, more particularly as the type levers actuated by the intermediate levers are also as arule arranged along an arc.

According to a further feature of the invention the intermediate levers of each row of keys are made the same length, so that they may be manufactured very economically by being stamped out. i

The above referred to improvement of the lateral guiding of the intermediate levers may according to the in vention be very favourably efiected, through the intermediate lever tilting points lying in slots of the tilting bar and being formed by a rod or the like passing through all the slots. Whilst in the known arrangements the lateral guide is constituted solely by the pivoting means employed, for instance by a rivet, which is all the more laterally loaded, the further the intermediate lever lies from the middle of the machine, in the novel arrangement the occurring lateral forces are intercepted in the region of the tiltingedge, so that lateralbearing slackness which. would affect the typing qualities of the machine and eventually lead to troublesome noises cannot occur, even after the machine has been in use for a long time.

When guiding of the intermediate levers in the region of their tilting points is not possible, according to the invention the intermediate levers may be given additional guiding means between the connecting means to the type levers and their tilting points, which are preferably formed by incisions (slots) bridging the individual intermediate levers. These incisions which are naturally brought close to the point of attachment of the connecting means to the type levers give good laterial guidance of the intermediate levers, so that -sirnilarly to the slotted guides in the region of the tilting points-wear of the attaching means and impairment of the typing qualities ofthe machine are out of the question.

According to the invention the guiding incisions may be provided on a bridge member which is movable in opposition to the force of a spring and extends over all the intermediate levers, the lateral surfaces of the guiding incisions for the intermediate levers preferably extending in a wedge-shaped manner with respect to one another. The arrangement of the incisions in a movable bridge member has the advantage, that on the one hand only slight frictional forces arise and on the other hand the intermediate levers are subjected in the region of their additional guiding to only slight wear, so that the machine will remain in proper working order, even after being 3 in use for a long time. A wedge-like formation of the incisions is specially to be recommended in all cases, in which for lack of space the bridge cannot be made so wide that, when one intermediate lever has been moved out of its position of rest, the remaining intermediate levers will remain in their guiding slots.

Preferably, the bridge is supported at its ends by means of link members to the machine frame, which have separate arms, to which the returning springs acting in opposition to the bridge motion are attached. As in the region of the inner walls of the usual machine frames there is usually ample space, the link members and their supports may easily be made strong, so that no premature wear can occur here as well.

In order to make still better use of the bridge as a functional part provision is finally made, according to the invention for utilizing the bridge motion for the control of other motions, for instance the ribbon control, the carriage shift control or the like.

Several constructional examples of the invention are illustrated in the accompanying drawings, in which:

Fig. 1 shows the arrangement according to the invention in simplified form, viewed from the side and in section,

Fig. 2 the same in plan view,

Fig. 3 a modified constructional form of the arrangement shown in Figs. 1 and 2 in side view and in section,

Fig. 4 a plan view of the modified construction,

Fig. 5 a side view of a further construction according to the invention with additional guiding means of the intermediate levers in section,

Fig. 6 a plan view of the constructional example according to Fig. 5,

Figs. 7 and 8 details of the construction according to Figs. 5 and 6.

According to Figs. 1 and 2 there are inserted in a key lever guiding comb member 1 with an upper striking fillet 2, key levers 3 which, swivelling about a rod 4, can be pressed downwards, as indicated by dot and dash lines 5. At their ends extending beyond the guiding comb member 1 the key levers 3 have striking keys 6. The rod 4 is fixed in a tilting bar 7 having several bends in it. The key levers 3 have in the region of their points of attachment (rod 4) extensions 8 which engage in guiding slots 9 of the tilting bar 7.

Between the attaching rod 4 and the guiding comb 1 which guides the key levers 3 in slots 10 the key levers 3 have upwardly directed extensions to which, intermediate levers 12 are attached by means of rivets 13. These intermediate levers 12 themselves have extensions 14, to which tension springs 15 are attached, which with their other ends are suspended in hook-shaped lugs 16 of the key levers 3. In the intermediate levers 12 there are suspended at the free ends pull wires 17 which are themselves connected flexibly to type levers 18. The type levers 18 are supported so as to be capable of rocking in a separate supporting member 19 which need not be further explained, as it does not concern the arrangement according to the invention. Similarly, the stop bar 20 for the type levers 18 has no bearing on the invention.

The tilting bar 7 forms with its front side 21 tilting points for the intermediate levers 12, so that, on the keys 6 being depressed, the intermediate levers 12 act in the manner of two-armed levers, that is to say, in the movement referred to, the arm 12a of each lever 12 is swung upwards and the lever 12b downwards. A change in the angular path of the arms 12a is effected through the front side, that is to say the intermediate lever tilting points, approach from the middle of themachine nearer and nearer to the guiding comb member 1 or to the striking keys 6. The return of the key levers 3 into their initial position is effected by the spring 15 already alluded to, which is tensioned during its depression.

In Figs. 3 and 4 dilferently formed key levers 22 are inserted in the guiding comb member 1 with atop Striking edge 2. These key levers 22 again support striking keys 6 and are supported also with their rearward ends on a rod 4. The rod 4 lies in a solid bar 23 which with slots 24 laterally guides the ends of the key levers 22 in the region of the rod 4. In contradistinction to the constructional form first described the key levers 22 have rearwardly directed projections 25, to which intermediate levers 26 are attached by means of rivets 27. The tilting points for the intermediate levers 26 are in this case formed by a rod 28 which is inserted similarly to the rod 4 in the solid bar 23, extending through slots 29 in the bar 23. The intermediate levers 26 engage over the rod 28 with elongated holes 3t) open at one end, so that again, on the striking keys 6 being depressed, the part 26a of the intermediate lever, lying to the left, moves upwards and that lying to the right of the rod 28, near the part 26b, moves downwards. The movements of the parts, which occur, are indicated by dotted lines 31. For the return of the intermediate levers 26 and of the key levers 22 is effected 0 by springs 32 which engage on the one hand at the key levers and on the other hand at hook-like extensions 33 of the intermediate levers 26. For magnifying the angular motions of the lever arms 26a, as the distance from the middle of the machine increases, in this case the rod 28 is arcuate, as is clearly shown in Fig. 4.

According to Figs. 5 and 6 there are again inserted in a guiding comb member 1 with an upper striking fillet 2 key levers 34 with keys 6, which with their rearward ends are suspended in a tilting bar 35 bent in the manner of a hook. Each key lever 34 has an arm 36, to which an intermediate lever 37 is linked. The link connection is effected by a rivet 38. At a downwardly directed projection 39 a spring 40 engages, similar to the arrangement in Fig. 3, which with its other end is suspended in the particular key lever 34. The intermediate lever tilting points are formed by a flange 41 of the tilting bar 35 and are, as in Fig. 2 arranged on two straight lines lying obliquely to one another. On a key 6 being struck, the lever arm 37a will-as in all the constructional exampes-move upwards and the lever arm 37 b downwards. The angular path of the lever arm 37a becomes greater, the further the corresponding intermediate lever 37 lies away from the middle of the machine, since with the increasing distance the individual intermediate lever tilting points get nearer to the striking keys.

For the better lateral guidance of the intermediate levers 37 there is provided in this case a bridge 42 extending over all the intermediate levers 37, which with slots 43 engages over the individual intermediate levers 37. The lateral surfaces 44, 45 of the slots 43 extend in a wedge-shaped manner with respect to one another. To the two ends of the bridge 42 are riveted bent-over linking members 46, 47 which themselves are rotatably supported on pins 49, 50 fixed to the machine frame 48. The link members have in addition arms 51 (cf. more particularly Fig. 5), to which tension springs 52, 53 are attached and which allow the bridge 42 always to rest on the intermediate levers. The link members 46, 47 are also provided with pins 54, 55 to which pull and push wires 56, 57 are flexibly connected and which control, for instance, the ribbon motion (not shown).

For the sake of clearness there are shown separately in Figs. 7 and 8 the bridge 42 with one link member 46 and an intermediate lever 37, which bear the same reference numerals as in Figs. 5 and 6.

I claim:

1. A type-bar actuating device for typewriters and like machines, comprising: a plurality of key levers, a key on each key lever, the keys being arranged in rows, intermediate levers connecting the key levers with the type bars, all the intermediate levers of each row being of the same length, and the points of connection of the intermediate levers with the key levers being co-axial for each row of keys, and a tilting bar located behind the points of connection pf the intermediate levers to the key levers and forming a fulcrum for the intermediate levers, the position of the fulcrum determining the relative length of the two arms of each intermediate lever, the said tilting bar widening towards the sides of the machine in such a way that from the middle of the machine towards the sides the fulcrum becomes progressively nearer to the keys, so that with the same distance of travel for all the keys each intermediate lever rocks through an angle conforming to the striking path of its associated type bar.

2. A type-bar actuating device as claimed in claim 1, the tilting bar consisting of a strip of metal bent several times in its longitudinal direction, and being formed with bearings for the key levers.

3. A type-bar actuating device as claimed in claim 1, the fulcrum for the intermediate levers being curved in a horizontal plane, the two outermost fulcra being the nearest to the keys.

4. A type-bar actuating device as claimed in claim 1, the tilting bar being formed with transverse slots in which the intermediate levers engage, and including a longitudinal rod extending through the slots and constituting the fulcrum for the intermediate levers.

5. A type-bar actuating device as claimed in claim 1, further comprising a spring-controlled movable bridge extending over all the intermediate levers, the bridge being formed with guiding notches engaging laterally over the individual intermediate levers between their fulcra and their points of connection to the type bars.

6. A type-bar actuating device as claimed in claim 5, the lateral surfaces of the guiding notches being inclined to one another in such a way that each notch is wedgeshaped.

7. A type-bar actuating device as claimed in claim 5, further comprising: link members at the ends of the movable bridge, an arm extending from each of the said link members, and springs attached to the said arms and to the machine frame to control the motion of the bridge.

8. A type-bar actuating device as claimed in claim 5, the motion of the bridge being utilized for the control of other motions, for instance the ribbon control and the carriage-shift control.

References Cited in the file of this patent UNITED STATES PATENTS 2,008,384 Benzing July 16, 1935 FOREIGN PATENTS 879,248 Germany June 11, 1953

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