US2008383A - Shift mechanism - Google Patents

Description

H. BENZING t July 16, 1935.

SHIFT MECHANI SM -3 sheets-s111561 1 Filed Dec. l, 1953 In ven/or' July 16, 1935. Y H .DBENZWG I 2,008,383

' SHIFT MECHANISM I Filed DGO. 1, 1953 I5 Sheets-Sheet 2 lvllllllll/iwww nPen/or.'

H. BENZING July 16, 1935.

SHIFT MECHANISM 25 Sheets-Sheet 5 Filed Deo. 1, 1935 I .Dann/or: j? f77' Patented July 16, 1935 UNITED STATES PATENT OFFICE Aktiengesellschaft Dresden, Germany vorm. Seidel & Naumann,

Application December 1, 1933, Serial No. 700,530 In Germany December 10, 1932 Claims.

The invention relates to a shift mechanism for typewriters,` calculating machines and the like with simple form Aof shift, and more particularly machines of that type in which the type bar seg- 5 ment is lifted and lowered in relation to the carriage. It has already been proposed in connection with shift mechanisms to employ alternately extending angle levers,l which limit the two extreme positions. These, however, have the disadvantage that the accelerations in respect of the lifting and lowering movements either merely increase or, vice versa, merely decrease. In consequence the one or the other extreme position cf the shifted portion terminates or commences merely with hard impact on the joints.

To overcome this drawback the segment or other part shifted is moved through the medium of a U-shaped rocker frame, which is mounted in the frame of the machine and may be lowered or` 2() lifted by means of two knee-joints, of which the one engages with the other at the middle joint, is situated approximately at right-angles thereto and is moved by the shift key bars, so that the extreme positions of both knee-joints may be limited by a common stop.

This arrangement has the advantage that with a shift-key movement which is of a uniform nature in itself the shifted part is raised slowly, as far as the middle, to top speed, which following thereon again slowly decreases down to zero in the extreme position.

The arrangement in question does away with all fixed or hard stops for limiting the extreme positions, and'provides the possibility of limiting the extended position of the two angle levers by means of merely one stop. This stop, therefore, may be of a soft, sound-damping material, as small irregularities in the transverse direction up to the extended state have no appreciable influence on the position of the shifted part.

It is necessary, however, that the bearings and pivot points be constructed with extreme care. The pivot points, therefore, must be entirely devoid of play, and should be made capable of subsequent readjustment, in order to ensure proper limitation in the extreme positions.

The details of the invention are illustrated in the drawings, in which Fig. 1 shows a possible form of embodiment of the shift mechanism of a'typ'ewriter in the stationary position, viewed from the top, wherein all parts have been omitted which are Unnecessary for comprehension of the operation of the 55 shift mechanism.

(Cl. IS7- 74) Fig. 2 is a section according to the line II-If in Fig. 1.

Fig. 3 is a view similar to Fig. 2, with the-shift mechanism in the operative position.

Figs. ,4-6 show sections through the different 5 pivot points.

Fig. 7 is a section according to the line VII-VII in Fig. 2 through the device for adjusting the stroke.

Fig. 8 shows a part of the locking means for the l0 shift bar in the operative position.

In the frame I of the machine there is mounted to rock about a journal 2 a U-shaped frame 3. In the vicinity of the two axes there are provided on this frame lugs 4 bent inwards at right-angles, each of which lugs terminates in a cantilever 5, which may possess a plurality of notches t, engaged selectively on either side by a spring l, which is secured in any way to the frame of the machine and serves merely to compensate the mass. The arms of the U-shaped frame 3 are engaged at 8 by links 9, the opposite ends of which are pivoted at l0 to the type bar segment i I. The type bar segment is guided between two vertical guides bars i3 by means of rolls l2. On the side on which the shift mechanism is located the 'arm of the frame 3 is extended beyond the pivot point 8, and carries at its end a stud i4 engaged by the lower end. of a knee-joint, the second joint portion of which is secured in permanent and rotatable fashion in a bearing It mounted on the frame of the niachne. The middle joint portion lli of the kneejoint l5a, l5?) is engaged by a second knee-joint I 8a, lb with its one end, the opposite end of which is mounted in permanent and rotatable fashion in the bearing i9 on the machine frame. The middle joint portion of this knee-joint is designated 2B. The lever |86 of this knee-joint is constructed as an angle lever, the free arm itc of which possesses at its end a stud 2l, which engages in the slot E2 of a lever 2li mounted in permanent and rotatable fashion on the frame of the machine at 23. The lever 2d possesses an arm 24', the end of which thrusts against a pin 25 on the shift key bar 26, which is mounted as usual in permanent and rocking fashion on the frame of the machine at 2l, and is connected with the shift key bar on the opposite side of the machine by a shaft.

A spring 28 on the lever 24 has the tendency to hold the knee-joint |8a, lb in extended or approximately extended position against the stop 3l, which is mounted on the frame l and is covered with an elastic material, whereby the type bar segment is safely limited in its upper position. 'I'he upper or stationary position of the shift key' bar is limited in the known fashion towards the top by a stop bar, which is preferably furnished with an elastic facing and cooperates with abutments 26 on the key bar 28. The springs 29 serve in the known manner to compensate the mass and hold the key bars in the elevated position.

If it is desired to actuate one of the type situated in the upper row on the type means, the type bar segment, with a carriage which is not movable in the vertical direction, must be moved downwards, either in anl inclined or, as in the present case, in a vertical direction. 'Ihis takes piace by depression of one of the shift keys 30. In this manner the lever 26 is rocked downwards about its fulcrum 21. 'I'he pin 25 thrusts against the end of the lever 24', and rocks the lever 24 against the action of the spring 28 about its fulcrum 23 into the position according to Fig. 3. This causes the arm I8c of the kneejoint to swing through the medium of the pin 2| about the. point I9, whereby the second arm |817, or its joint 2li respectively, which at the same time constitutes the pivot point of the knee-joint |8a, |817, moves downwards over a corresponding arc and accordingly extends the kneejoint I 5a, I5b, until the lever I 5b strikes with its abutment I5b', which if desired may also be furnished with a facing of elastic material, against the stop 3|, which is mounted on the frame of the machine and is furnished with an elastic facing.

Since the knee-joint I5a, I5b is secured with one end in the bearing I6, the end point I4 is able to yield only in a downward direction, and describes van arc about the journal 2 on* the frame 3. 'I'he pin 8 accordingly also moves downwards, and draws the type bar segment in a downward direction through the medium of the link 9. When the lower shift position of the type bar segment has been reached, the kneejoint I5a, I 5b is in its extended position and touches the stop 3|, in the same fashion as the knee-joint I8a, I8b is extended and thrusts against the stop 3| in the extreme upward shift position of the segment.

The movement of the type bar segment in both directions is dependent on the pivot point I4. Dependent on the fact as to whether the movement of this point is accelerated or retarded, there occurs an acceleration or retardation in the movement of the type bar segment. Upon shifting or when releasing the shift the movements of the point I4, and accordingly of the type bar segment, are as follows: Owing to the angle-lever effect there occurs in the arrangement according to the invention towards the extended position of an evenly moved or also somewhat accelerated point of the knee-joint a considerable delay in the movement of the affected point, i. e., large movements on the part of the joint portion I1 or 20 and correspondingly small movements of the end point'20 or I1, and consequently I4. The lowering and lifting movement of the type bar segment II will accordingly also be greatly retarded towards the extreme positions. A gentle shifting motion is obtained, therefore, in both directions.

'I'he position of the stop 3| is so chosen that even should the elastic facing of the stop be somewhat pressed in by use no perceptible variation takes place in the extreme positions of the type bar segment, as the small movements of the points I1, 20 in the range of the extended position correspond with still smaller movements of the point I4. A

An important factor as regards faultless operation of the shift mechanism when employing a system composed of two knee-joints is the proper embodiment of all pivot points and joints.

In Fig. 4 there is shown a possible form of embodiment of a bearing of this kind on enlarged scale such as may conveniently be employed for the fixed bearing points I6 and I9. A block. a, which is secured in any suitable fashion to the frame of the machine, possesses an incision b, so that there is formed a fork-like portion c. In the part c there is provided a stud d, which is conical, tapered, part-spherical or also pointed at its end, and carries, for example, a worm screw, which may be secured in the usual fashion by a nut e. 'Ihe lever f to be mounted possesses a boring, which corresponds with the end of the stud and engages with the same, the lever thus being securely mounted.

Figs. 5 and 6 show possible forms of embodiment for pivot points which are not of a permanent kind, such as may be employed for example in connection with the points 8, I0, I4 and zo (Fig. 5) and the point l1 (Fig. 6). A yoke portion g encompasses with itstwo arms g1, g2 the levers h, h1 or hz to be pivotally connected.

'Ihe studs d provided in the two arms g1 and g2 jamming in the jointif, for example, owing to differences in the manufacture, the lever h does not swing exactly in the correct plane. According to Fig.` 6, three levers are provided, of which the middle lever h2 possesses on either side studs h2', which engage in corresponding bores in the adjacent levers. These studs h1 and h2' in the case of Weak levers are preferably formed in a stamping operation by means of correspondingly shaped dyes, which act simultaneously on both sides and are hollow at the centre for the purpose of forming the studs. A shoulder 32 on one of the levers supports the yoke g, and thus prevents a swinging backwards and forwards and accordingly a disturbing noise.

'I'hese bearings offer advantage in various respects, particularly as regards large-scale production and manufacture on a moving belt. The studs may be produced by automatic machines Without subsequent finishing, and the levers are stamped with special tools in one operation; the new bearings nevertheless operate accurately, since in a manner of speaking the same are able to yield. Small differences in the manufacture, which are diicult to avoid, may be compensated by adjustment of the bearings. The adjustment may be performed readily as considered necessary, and after any wear which may take placethe bearings may be tightened, whereupon the transmission will again occur without play,

For exact adjustment of the distance which the type bar segment is required to move in relation to the carriage upon the shifting operation, an adjustment means is provided which is simple and accurate in operation. The same is to be recognized in Figs. 2 and 3 at the joint 8 and is shown in section on enlarged scale in Fig. 7. In the arms of the U-shaped frame 3 there is furnished an arcuate slot 33, the centre point of curvature of which coincides with the point HI.

Y In this guide a slide 34, fitting well, may be reciprocated to a certain extent in the direction of the arrow. At the centre of preferably the longer guide edge of the recess 33 forming an arch there is provided a groove 33 disposed vertically to the direction of movement of the slidev` 34, into which groove there projects the stud 35 of a conical rotary member 36 furnished with a s lot suitable for manipulation by means of screw-drivers. This rotary member may. be turned in a well fitting bore in the slide 34 and displaces the slide 34 by reason of the fact that the same is anchored at a point 35 of its periphery outside of the slide. The slide at the same time is constructed as a cover plate, and may be firmly connected with the lever arm of the frame 3 by means of screws 31, the bores for which in the 'cover plate are oblong holes, whereby the rotary member 36, which in the present case is vconstructed in the form of -a truncated cone, is also preventedl from falling out. The slide furthermore possesses the bearing 8, which preferably is constructed in accordance with Fig. 5, in which in this case the lever h corresponds with the slide and the lever h.l with the intermediate lever 9. If the slide 34 is displaced, the lever arm mounted at the point 2, and accordingly the distance covered upon the shifting of the type bar segment H will be varied, without taking effect on the basic position of the type bar segment.

To improve the shift as regards more simple and rapid operation in connection with lengthy shift, there is provided the shift lock described in the following. The key fixing lever 3B, which is oscillatory about the saine point of rotation 2l as the shift key bar 26 possesses a pin 39, which cooperates in such fashion with a slot guide @il in a specially formed intermediate lever 42 mounted permanently but in rocking fashion on the machine frame at li that upon depression of the locking key 43 this intermediate lever is also rocked downwards in positive fashion, as shown in Fig. 8. The one edge ft2 of this intermediate lever is able tov slide on a bolt Ml of the shift key bar 2&5. This working edge possesses at the point corresponding withl the depressed position a recess in the form of a quarter of a circle, into which the bolt ifi is able to move. If, now the key system after depresson by means of the key i3 is left to itself, there results by reason of the cooperation of a plurality of equally directed turning moments between the bolt itl and the recess constituting the quarter circle a tension which holds the shift key system in the depressed position until a light pressure against one of the keys Si@ produces an oppositely directed turning moment, which overcomes the tension, whereby the intermediate lever if moves upwards with the lever 3@ by reason of the spring lili and thus releases 'the lock. The bolt iid is mounted in an oblong aperture il@ in the shift key bar 22d, so that any differences at this point arising from manufacture may be readily coinpensated. For reliable operation on the part of the locking means it is essential that the mounting of the intermediate lever takes place between the'fulcrum of rotation il of the shift key bar 26 and its pressure bolt lit.

It will be understood that no restriction is made to the particular form of embodiment illustrated in the drawings, and that various modifications are quite possible within the meaning of 1. A shift mechanism for typewriters, calcu- K lating machines and the like with simple form of shift, including in combination a U-'shaped frame mounted to rock in the frame of Athe machine to shift the type bar segment, a shift key two knee-joints connecting the shift key and the U-shaped frame for lowering 'and lifting the .said U-shaped frame upon actuation of the shift key, the one of the said knee-joints engaging with the middle joint 'position of the second kneejoint, being situated kapproximately at rightangles to the second knee-joint andy being moved by the shift key bar, and a common stop for limiting the straight positions of the two kneejoints. y

2.A shift mechanism for typewriters, calculating machines and the like with simple form of shift, including in combination a U-shaped frame mounted -to rock in the frame of the machine to shift the type bar segment, a shift key two kneejoints connecting thev shift key and the U-shaped frame for lowering and lifting the said U-shaped frame upon actuation of the shift key, the one of the said knee-joints engaging with the middle shift, including in combination a U-shaped .frame mounted to rock in the frame of the machine to shiftthe type bar segment, a shift key, two cooperatingknee-joints connecting the shift key and the U-shaped frame for lowering and lifting the said U-shaped frame upon actuation of the shift key, ya common stop foi-limiting the straight positions ofthe two knee-joints, and an adjustment means mounted in the said U-shaped frame' for exact adjustment of the extent of movement of the type bar segment, the said adjustment 4 means including adjustable bearing joints mounted in arcuate guide slots in the arms of the said U-shaped frame, links connecting the arms of the U-shaped frame with the type bar segment, supporting bearings for the said links carried by the said bearing joints, and a cranked pin for displacing the said joints.

4. A shift mechanism for typewriters, calculating machines and the like with simple form Lof shift, including in combination a U-shaped frame mounted to rock in the frame of the machine to shift the type bar segment, a shift key, two cooperating knee-joints connecting the shift key and the U-shaped frame for lowering and lifting the said U-shaped frame upon actuation of the shift key, a common stop for limiting the straight positions of the two knee-joints, and an adjustment means mounted in the said U-shaped frame for exact adjustment of the extent of movement of the type bar segment, the said adjustment F means including adjustable bearing joints mounted in arcuate guide slots inlthe arms of ythe said U-shaped frame, links connecting the arms of the U-shaped frame with the type bar segment, supporting bearings for the said links carried by the said bearing joints, a slide reciprocating in the arm of the said U-shaped frame, a rotary 'member having its longitudinal axis vertical to the direction of movement of the said slide. a cranked pin for displacing the said joints mounted on the said rotary member, the said rotary member co-operating with its jacket surface only in part with a bore in the wall of the said slide, and a projection on the periphery of the end face of the said rotary member, the rotary member upon its rotation swinging longitudinally about the said projection.

5. A shift mechanism for typewriters, calculating machines and the like with simple form of shift, including in combination` a U--shapedl frame mounted to rock in the frame of the machine to shift the type bar segment, a shift key two co-operating knee-joints connecting the shift key and the U-shaped frame for lowering and lifting the said U-shaped frame upon actuation of the shift key, links connecting the arms of the U-shaped frame with the type bar segment, adjustable joints devoid of play for connecting all levers, knee-joints and links of the shift mechanism, and a common stop for limiting the straight positions of the two knee-joints.

HU GO BENZING.

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