US2049826A - Carriage-feeding device for typewriters - Google Patents

Description

Aug. 4, i936. H. scHULER 2,049,826

CARRIAGE FEEDING DEVICE FOR TYPEWRITERS Filed Nov. 14, 1935 2 Sheets-Sheet 1 IVY/Venta?? /i/afa. fcLZjer Aug. 4, 1936. H. scHULl-:R 2,049,826

CARRIAGE FEEDINCT DEVICE FOR TYPEWRITERS Filed Nov. 14, 1933 2 sheets-sheet 2 iufm@ Patented Aug. 4, l1936 UNITED STATES PATENT oFFicE CARRIAGE-FEEDING DEVICE FOR TYPEWRITERS Application November 14, 1933, Serial No. 697,971 In Germany November 19, 1932 10 Claims.

'Ihe present invention relates to a carriagefeeding device for typewriters, preferably noiseless typewriters, in which the types are relieved of key action at the printing point and in which 5 the letter-feed travel of the carriage is effected by the type carriers themselves or by their drive or link members through a universal bar.

The object of the invention is to provide a rapid and reliable carriage-feeding and particul larly to prevent double and faulty letter-feed movements of the paper carriage, which frequently occur owing to rebound movements of the type carriers in previously known typewriters of this kind, on violent key operation. 15 The mechanism according to the invention overcomes diiiiculties which occur in typewriters of this kind due to the type carriers being conflned in a very restricted space in front of the platen and all the drive members for the universal bar being concentrated in a small arc. The invention also aims at avoiding differences in the actuation of the universal bar by the middle and by the end type carriers respectively. The aforesaid advantages are achieved according to this invention which consists in that the operation of the members Which effect the letterfeed movements of the vcarriage takes place during a path of the types which is shorter than half that path which they traverse between the point, where the influence of the keys ceases, and the point of printing.

The drawings illustrate one embodiment of the invention as applied by way of example to a noiseless typewriter and in which:

Figure 1 is a side view partly in section showing the complete drive mechanism of the type heads with the parts in normal position,

Fig. 2 is a similar View showing also a carriage escapement mechanism with the parts at the instant of beginning or finished operation of the carriage-feeding.

Fig. 3 is a side view of the escapement mechanism with fixed dog in engagement with the escapement wheel at the instant of impact of 45 the type on the platen, and

Fig. 4 is a plan view of the universal bar.

In the typewriter illustrated, each type bar I which carries the type lhead 2a with the types is supported by two links 3 and 4. On depressing the key 5, the key lever 6 actuates, through an intermediate rod l, a hook-shaped drive member 8 provided with a camming curve member. The camming curve member actuates a transmission lever 9 which through the agency 55 of further transmission members II, I2, and. I 3

operates the type bar I from the normal position shown in Fig. 1 toward the platen I4 until the key and the key lever 6 reach the lowest position 5a and 6a indicated in Fig. 1 by dotted lines. During this movement the types 2 reach 5 the position shown by the dotted line I5 in which the type bar I and the transmission members 9, II, I2 and I3 are relieved of the action of the key 5, the outer end of the transmission lever 9 disengaging the camming curve member of the 10 drive member 8, and continuing its further movement independently of the latter. The further movement of the actuated type 2 up to the printing point indicated by the dotted line I6, and that of the associated mechanism 9, Il, i2, I3, I, 2, and 3 is effected exclusively under the action of momentum of the type bar I reinforced by the yweight Ill. The key 5, key lever 6, and drive member 8 do not participate in this further movement.

'Ihe operation of the members producing the letter-feed movement of the carriage is effected by means of lugs I8, one on each link 3, which move in dependence with the type bars I and which all operate on a universal bar I9. According to the present invention this actuation of the universal bar I9 and the other parts producing the carriage-feeding only begins when more than one-half of the path of the type 2 between the lines I5 and I6 has already been traversed, that is, when the corresponding type- 2 has reached the position indicated in Fig. 2 by the dotted line Il. Experiment has shown that the distance of the type 2, corresponding to the beginning of letter-feed operation (line 35 Il), from its printing point on the platen (line IS), should be so dimensioned that it amounts preferably to only one-fourth to one-iifth of the distance which exists at the instant of cessation of key movement and of the beginning of momentum movement, between the type 2 (line I5) and the printing point (line i6).

Heretofore the actuation of the members producing the carriage-feeding in typewriters, of this type began during the depression of the key and the movement of the parts associated therewith, or it began in the instant in which the key movement ended and the action of momentum of the type bar began. The beginning of the letter-feed operation thus lay in front of or at the point of type movement designated in the present example by line I5. For this reason it frequently happened that the type 2 after complete printing had already returned to the position of line I5 before the return movement 55 of the key and of the key lever from the position designated by 5a and 8a into the position shown in full lines, so that the outer end of the transmission member 9 moving with the type 2 under the influence of momentum'would again strike against the camming curve member oi the drive member 8 in its return movement. This produced a rebound and to and fro movement of the transmission members 9, Il, I2, I3, the ilyweight I0, and of the type bar I, causing the type 2 to move beyond the position of line |5 and again toward the platen |4.

In the known mechanisms, moreover, as above described, even a small movement of the type 2 beyond the line I5 in the direction of the platen |4 initiates a new letter-feeding step of the carriage, so that on violent striking of the key 5 or on the latter sticking in the position 5a under a single manipulation, owing to the'repeated rebound of the transmission members 9-I3, two or more letter-feeding steps may take place. Contrary to this, when the carriagefeeding device according to the present invention is provided, no letter-feed movement of the paper carriage is initiated when the type 2 after being freed of influence by the key, has moved beyond the line I5, so that the rebound movements when the transmission members strike against the drive members on the return of the type 2 after impact against the platen I4 no longer produce double letter-feed movement o! the paper carriage.

In the mechanism illustrated by way or example, the letter-feed actuating lugs I8 are integrally arranged on the iront links 3 of the type bars I. In the position shown in Fig. 2 the actuating lug I8 bears against the universal bar I9. The universal bar I9 is attached by means of two angular projections 20 to a bridge consisting of a web 2| and two similar laterally bent arms 22 and 22a. To these arms 22 and 22a there are jointedly connected at pivotal points 25 and 26 two pairs of links 23 and 23a,

and 24 and 24a which are of equal length and parallel to each other. The pair of links 23 and 23a is xedly mounted on a shaft 21 which is journalled in a frame 29 fixed to the machine frame 28. Similarly the pair of links 24 and 24a is mounted on a shaft 30 which is also journalled in the frame 29. The shaft 30 has a lever 3| iixedly connected thereto. On the link 24 there is provided a lug 32 in which is mounted an adjusting screw 33which engages a stop 34 on the frame 29. By adjusting the screw 33 the pair of links 24 and 24a jointedly connected to the other pair of links 23 and 23a by means of the arms 22 and 22a of the bridge 2|, can be tilted whereby the position of the universal bar I9 relatively to the actuating lug |8 of the type bar link 3 is varied. The link 24 and lever 3| are connected by a small bar 35 which is attached at one end to a tension spring 38 and at the other end to a pin 31 on the shaft 21, said spring serving to permanently urge the shaft 21 and the pair of links 23 and 23a to swing in a counter-clockwise direction. By this means the bridge 2|, 22, 22a and the universal bar I3 at the end of a stroke are returned to the initial position in which the adjusting screw 33 bears against the stop 34 of the trame 29.

While the type 2 traverses the path between the lines I1 and I6, the actuating lug I8 of the type bar link 3 moves the universal bar I3 downwards a small distance. This distance, owing to the exact parallel guiding oi' the bridge 2|,` 22 and 22a, by means of thetwo pairs of links 23 and 23a, and 24 and 24a is equally large for all the actuating lugs I8 which are disposed around a very small arc.

The rotation of the shafts 21 and 30 is transmitted through a lever arm 3| on the shaft 30 to a rod 38 pivoted to sa'id arm and the free end of the rod 38 carries an adjustable stop nut 39 which engages the known carriage dog rocker escapement 40. 'Ihe dog rocker 40 is pivoted on a fixed pin 4I and carries a tlxed dog 42 and a loose dog 43.

During the letter-feed operation the fixed dog 42 is brought in known manner into engagement with the escapement wheel 44, the loose dog 43 moving out of engagement with this wheel and under the action of a weak spring snapping into the position corresponding to the next tooth of the escapement wheel 44.- When printing is completed the ilxed dog 42 releases the wheel 44 -and the reengaged loose dog 43 permits the drive spring of the paper carriage to eiect rotation of the escapement wheel 44 through one tooth and therefore a movement of the paper carriage by one letter space.

The cooperation between this known to and iro movement of the two dogs 42 and 43 and the.

owing to the long lever 3| projecting from the shaft 33 and also because the connecting rod 38 between this lever and the dog rocker iii engages the latter at a certain distance from its pivot pin 4I. This distance is smaller than the distance of thev two dogs 42 and 43 from the pivot pin 4I of the dog rocker 40 and smaller than the length of the lever 3|.

The letter-feed operation initiated byL the forward movement of the type toward the platen I4 in the position designated by the line |1, terminates during the return movement of the type 2 after printing on attaining the same position (line |1). Exceptionally rapid operation oi the carriage letter-feeding is made possible by the very small movement of the universal b'ar I9. This small movement of the universal bar I9 is transmitted with magnincation by means of the lever 3| and the rod 38 to the escapement dogs 42 and 43.

In such noiseless typewriters, especially typewriters with type bars, the type guide 45 is brought quite close to the platen |4 and the guide slot must be kept as short as possible because some of the type bars move at a very acute angle to the platen I4. Therefore the type heads 2a must be very accin'ately and reliably guided at the instant of printing. In this connection the device according to the present invention is very advantageous because the operation of the letter-feed mechanism takes place= entirely in the interval in which the type head 2a carrying the types 2 is in the slot of the type guide 45. Thus while the universal bar I9 is moving and while the link 3 of the type bar I supplies the necessary energy for actuating the:

letter-feed mechanism, the types 2 and their type heads 2a are guided on all sides so that departure from the printing direction is avoided. The letter-feed operation is reliably terminated when a type head 2a leaves the slot guide, and a new carriage-feeding is initiated only when the next type head 2a has entered the guide 45. Thus very strong and rapid successive type strok against the platen may be eiiected without disturbing the step by step paper carriage.

I claim as my invention:-

l. In a typewriter, a paper carriage, means for the stepwise letter-feeding of the carriage, key levers, type headsdrive means connecting the key levers with the type heads during the initial portion only of the path of said heads and which type heads are disconnected from the drive means during the subsequent portion of their path to printing position, and means movable proportionally to the movement of the type heads and timed to impart actuating steps to the carriage letter-feed means only during the movement of the type heads on less than onehalf of that portion of their path on which they are disconnected from said drive means.

2. In a typewriter, a paper carriage, means for the stepwise letter-feeding of the carriage, key levers, type heads, a type guide arranged quite close to the platen, drive means connecting the key levers with the type heads during the initial portion only of the path of said heads and which type heads are disconnected from the drive means during the subsequent portion of their path to printing position, and means movable proportionally to the movement of the type heads and timed to impart actuating steps to the carriage letter-feed means only during the movement of the type heads on less than one-C half of that portion of their path on which they are disconnected from said drive means during which movement the type heads are guided in the said type guide.v l

3. A carriage-feeding device f or typewriters, especially noiseless typewriters, in which Athe type bars are relieved of key action on a portion of their path adjacent the printing point, comprising an escapement mechanism for carriage letter-feeding, and means for actuating the escapement mechanism by the movement of the type bars carrying the types, said means being arranged to actuate the escapementv mechanism only during the movement of the types adjacent the printing point on a path which is smaller than half the length of the portion of the path on which the types are relieved of key action. l

4. A carriage-feeding device according to claim 3, in which the escapement mechanism is actuated by means of a universal bar supported feeding of the by two parallel pairs of links so that the bar is moved an equal amount by all of the type bars during their actuating movement, and in which an adjustable stop is provided on one of the links to adjust the initial position of the universal bar,

5. -In a typewriter, a paper carriage, means for the stepwise traverse of the carriage, key levers,

type heads, driving connections between the keyl levers and type heads and adapted' to disconnect said heads from said levers at an intermediate point of the travel of the heads towards the printing point. and means connected with said type heads and so located as to engage operatively the carriage traverse means only in that part of'thevtravel of the disconnected type heads lying immediately in front of the printing point and less than half the distance between the printing point and said intermediate point.

6. In a typewriter, a frame; a paper carriage; an escapement mechanism for carriage letterfeeding; key levers; type heads; driving connections between the key levers and the type heads and adapted to disconnect said heads from the levers at an intermediate point of the travel of the heads towards the printing point and a pair of links jointed to each head and pivoted in the frame; means for actuating ,the eseapement mechanism, said means comprising a universal bar and intermediate members between the universal bar and the escapement mechanism; and projections on onev of the links of each pair, all o! said'projections being so located as to engage operatively said universal bar, and said universal bar and said intermediate members being so arranged that the escapement mechanism is actuated only in that part of the travel of the disconnected type heads lying immediately in front of the printing point and less than half the distance between the printing point and said intermediate point.

7. In a typewriter, a frame; a paper carriage; an escapement mechanism for carriage letterfeeding; key levers; type heads; driving connections between the key levers and the type heads and adapted to disconnectsaid heads from the levers at an intermediate point of the travel oi' the heads towards the printing point and a pair of links pivoted in the frame and jointed to each head, one of said links being nearer the paper carriage than the other link; means for actuating' the escapement mechanism, said means comprising a universal bar and intermediate members between the universal bar and the escapement mechanism; and projections on the links nearer the paper carriage, all of said projecv tions being so located as to engage operatively said universal bar, and said universal bar and said intermediate members being so arranged that the v escapement mechanism is actuated only in that part of the travel of the disconnected type heads lying immediately in front of the printing point and. less than halt the distance between the printing point and said intermediate point.

8. A typewriter according to claim 6, in which the projections are located close to the pivots of the links with the frame.

9. A typewriter according to claim 6, in which the operative movement of the universal bar from its normal position is guided by links, and

that of the projections.

HUGO scrrLER.

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