US2913090A - Carriage mechanism for typewriters - Google Patents

Description

Nov. 17, 1959 H. L. THoLsTRUP 2,913,090

CARRIAGE MECRANISM RoR 'mxswRI'rRRs l Q 4mm/Ey- Nov. 17, 1959 H. 1 .'1'HoLsTRUP 2,913,090

CARRIAGE MECI-IANISM FOR TYPEWRITERS Original Filed oct. 4. 195e IN V EN TOR. /fE/v/e y L //ozs mu y 147' 7 RA/EV Nov. 17, 1959 H. L. THoLs'rRuP 2,913,090

CARRIAGE MECHANSM FOR TYPEWRITERS original Filed oct. 4, 195e e sheets-sheet 4 IN V EN TOR.

Nov. 17, 1959 H. l.. THoLsTRUP 2,913,090

CARRIAGE MECHANISM FOR TYPEWRITERS original Filed oct. 4. 1956 csheets-sneet 5 l fe) \\\KI'."

IN VEN TOR. Hf/vy Z. 79m .f7/MP H. A| .T||o|\ s'|-RUP 2,913,090 CARRIAGE MECHANISM FOR TYPEWRITERS original Filed oci. 4,1956 Y Nov. 17, 1.959

6 Sheets-Sheet 6 IN VEN TOR. #5A/R y l 7240i; new

United States Patent AO CARRIAGE MEcHANrsM Fon TYPEWRITERS Henry L.' Tholstrup, Rochester, N.Y., assignor to Commercial Controls Corporation, Rochester, N.Y., a corporation of Delaware` Orig'nal application October 4, 1956, Serial No.

now Patent No. 2,900,065, Divided and this application No. 712,341

Claims. (Cl. 197-60) 613,900, dated August 18, 1959. January 31, 1958, Serial p Mechanism for Power Driven Printer, the power connection between the drive mechanism and the type levers is such that the type levers cannot be shifted byshifting the type basket between upper and lowercase positions. Itis, therefore, necessary to provide a special platen mounting carriage whichk provides for the shifting` of the platen between upper and lowercase printing positions.

It is, therefore, the principal object of this invention to provide a carriage structure for mounting the platen such'that the platen may be shifted between upper and lowercase positions in reference to a iixed type impact point.

' It is a further object of the invention to provide power means in conjunction with the carriage structure for shifting the platen into both uppercase and lowercase positions.

These and other objects and advantages of the invention will become apparent from a reading of the following specification in reference to the'drawings which form a part of this application, and in which drawings:

Fig. 1 is a side elevational view of acarriage mechanisrn in association with a power operated printer;

Fig. 2 is a horizontal view through the base of the carriage, taken on line 2 2 of Fig. l, parts being broken away to show underlying structure;

Fig. 3A is a vertical sectional view through the carriage of the printer, looking from the left and illustrating platen support and shifting mechanism at the right end of the carriage while the platen is in lowercase printing position;

Fig. 3B is a vertical sectional view on the same plane as that'illustrated in Fig. 3A, Fig. 3B illustrating power transmitting mechanism in the base of the printer, and Figs. .3A and 3B together constituting a continuation of the related mechanism at the right side of the printer;

Fig. 4 is a View on the sarne plane as Fig. 3A, showing, however, the platen shifted into uppercase position;

Fig. 5 is a view taken on line 5 5 of Fig. 4;

Fig. 6 is a view taken on line 6 6 of Fig. 4;

Fig. 7 is a fragmentary View of certain of the power transmitting mechanism shown in Fig. 3B, showing, however, the illustrated parts in the position occupied during uppercase printing;

Fig. 8 is a sectional view on line 8 8 of Fig. 3B;

, Fig. 9 is a vertical sectionalv view on line 9 9 of Fig. 3B; K

Fig. 10 is a horizontal sectional view on line 10-10 of Fig. 9; and

Fig. l1 is a diagrammatic representation of the platen control mechanism.

" ,A positive drive connection for the type levers requires that the type basket be fixed in relation to the power transmitting system. Therefore, resort must be had to a system for printing upper and lowercase characters which is compatible with a xed type basket. In printers of the conventional typewriter category, the type basket is disposed in an upper position for the typing of lowercase characters and is depressed to a lower position for the printing of uppercase characters. This arrangement, however, is not suitable in a machine having a fixed type basket; therefore, mechanism is provided herein whereby the platen may be` shifted upwardly for the typing of uppercase characters and returned to a lower position for the typing of lowercase characters. One form of mechanism for accomplishing these operations is illustrated in the drawings, and reference thereto will now be had in the description that is to follow.

A carriage 10 constitutes the vehicle for a platen 12 and a paper roll holder 14. The carriage consists essentially of a base plate 16 (Fig. 2) having a pair of upstanding'end walls 18 and 20. Fixed in the end walls 18 and 20 and located under the base plate 16 of the carriage are a pair of parallel guide rods 22 and 24. An identical pair of guide rods 26 and 28 are iixed in the side walls of a base frame 30. The guide rods 22 28 cooperate with a iioating carriage truck 32. The carriage truck 32 has a pair of elongated bearing sleeves 34 adapted to receive and slide on the bearing rods 22 and 26, respectively, and a pair of shorter bearing sleeves 36, which are adapted to receive and slide on the bearing rods 24 and 28, respectively. l

It will be seen, therefore, that the carriage truck 32 constitutes the connection between the carriage 10 and the base frame 30 of the printer. As shown in Fig. 1, an escapement rack '38is iixed to the bottom of the carriage frame and thereby controls the movement of the carriage transverse of the printer frame 30. Movement Iof the carriage truck 32 is controlled by a pair of sta.- bilizing tapes 40 and 42 which are effective-to limit the transverse movement of the carriage truck 32 to one-half lthe distancetraversed by the-carriage 10. The stabilizing tape 40 is trained about a pulley 44 attached to and extending laterally from one face of the carriage truck 32, one end of the tape 40 being attached to an anchor 46 iixed to the inner face of the printer frame 30- at one side thereof, and the other end of the tape being fixed to the same side of the printer by an anchor 48 located at the inner face of the end plate 20. In like manner, the tape 42 is trained about a pulley 50 txed to and extending from the opposite face'of the carriage truck 32, while its respective ends arel also anchored to the opposite Wall of the typewriter frame 30 by means of an anchor 52 and to the inner face of the end plate 18 by means of an anchor 54. From the foregoing description, it will be seen that as the carriage is reciprocated in respect to the printer frame, the carriage truck 32 will slide in the same direction on the guide rails 22-28, but this movement will be limited by the tapes to half the distance of carriage travel.`

The platen 12 is supported for rotation in a pair of identical platen support plates disposed respectively adjacent the end walls 18 and 20 of the carriage on which end walls the respective plates are mounted for oblique movement in an up and down path, whereby the platen can be shifted between lupper and lowercase printing positions. Since the platen support plates arev identical, their form and mounting may be observed by reference to Figs. 4 6, wherein is illustrated a platen support plate 56 which is associated with the carriage end wall 18y at the right of the printer. -The platen support platesr are mounted by means of reciprocating guide structures, one of which is shown in Fig. 5. In Fig. 4, lfor example, the platen support plate 56 has attached thereto a pair 3 of brackets 58 and 60 in each of which is fixed a depending guide pin as, for example, a guide pin 62 associated with the bracket 60. These guide pins are adapted to slide in guide bearings 64 and 64a which are mounted in the end wall 18 of the carriage. By means of a pair of such guide structures associated with each of the platen support plates, these plates are mounted for movement such that the platen 12 can be raised for the typing of uppercase characters, as shown in Fig. 4, or lowered for the printing of lowercase characters, as shown in Fig. 3A.

The platen supporting plates are operated into their respective upper and lower positions by means of a linkage system, of which that associated with the platen supporting plate 56, is shown in Figs. 3A and 3B. .lournalled in the side plate of the carriage 10, for example, is a lever 66 which is capable of rocking about a mounting pin 68. The lever 66 and the platen supporting plate 56 are operatively connected with each other by means of a link 70 which has one end thereof pivoted to the platen supporting plate 56 by means of a stud 72 while the other end thereof is pivoted to the lever 66 by means of a pin 74, which is located slightly above and in front of the pivot 68 about which the lever 66 moves. This constitutes the lever 66 and the link 70, an eccentric device which is adapted to exert an operating force on the platen support plate 56 which is generally parallel to the axis of the guide pins 62.

The lever 66 is connected to an actuating plate 76 by means of a link 78. The actuating plate 76 is keyed to an upper shift-shaft 80 which extends between the end plates of the carriage and is journalled therein for rocking movement. By reference to Fig. 4, it will be seen that when the shaft 80 is rotated in a clockwise direction, the actuating plate 76 will pull the link 78 in a downward direction, thereby rocking the lever 66 in a counterclockwise direction. This effectively elevates the platen supporting plate 56 to the position illustrated in Fig. 4 where the platen 12 is positioned for uppercase printing. This is the position of the parts illustrated in Fig. ll which is a diagrammatic presentation of the mechanism involved for shifting the platen from one position to another.

By reference to Fig. 11, it will be seen that the opposite end of the upper shift-shaft 80 has also keyed thereto an operating plate 82 which serves thesame function as the operating plate. 76 but which has a coniiguration somewhat different by reason of the fact that while the plate 76 moves in one direction, the plate 82 must produce a motion which is effective in the opposite direction.

The operation plates 76 and 82, and consequently the upper shift-shaft 80, are alternately moved from one position to another by means of a pair of shift tapes 84 and 86 interconnecting the operating plates 76 and 82, respectively with an intermediate shift-shaft 88 located in the base of the printer. The intermediate shiftshaft 88 extends transversely of the printer base and has its ends journalled in the side Walls of the base, so that the shaft may be rocked from one position to another by mechanism shown in Figs. 3B, 7 and 8. In these figures, the intermediate shift-shaft 88 carries at each end generally similar mechanism for imparting rocking motion to the shaft. The mechanism shown in the figures referred to is that located at the right side of the. printer which may be considered the mechanism for shifting the platen to its lowercase position. As stated, the mechanism at the left end of the intermediate shift-shaft 88 is generally similar and such differences as exist will be pointed out in reference to the diagrammatic View of Fig. ll; it being pointed out here that themechanism at the left side of the printer is that which4 controls the rocking of the shaft 88 for shifting the platen mechanism into its uppercase printing position.

A bell crank shaft 90 has mounted at opposite ends 4 thereof platen shift bell cranks 92 which are identical. The lowercase shift bell crank of Fig. 3B will serve to disclose the structure.

These bell cranks are designed to transmit operating power to the shift mechanism by means of an interconnesting link, such as a link 94 associated with the lowercase bell crank '9 of Fig. 3B. The shift bell cranks are operated from a power shaft 96, as fully described in my above-noted application for patent, and such operation is under control of shift magnets, in all respects the same as more fully described in said application.

Briey: a bell crank 92 is rocked about a bell crank shaft 90' by means of a drive plate 98 fixed for rotation with the powerV shaft 9'6. Extending from one face of the drive plate 98 are a pair of drive pins 100' and 102. These drive pins are adapted to cooperate with elements of the bell crank 92 to drive the bell crank through its operative stroke. By reference to Fig.` 3B, i t may be seen that the bell crank 92 carries a bellV crank latch. 104,. a guide plate 106, a stop pawl 108 and a pair of lugs: 110 and 112. The bell crank latch 104 is pivoted on the bell crank 92 by means of a pivot pin 114. The bell crank latch 104 is biased about the pivot pin 114. in aV clockwise direction (as viewed in Fig. 3B) by means of a spring 116 which extends between the free end of the bell crank latch 104 and the bell crank 92. The bell crank latch 104 is normally held in retracted position by a bell crank trip lever 118. The bell crank trip lever 118 is pivoted on a trip lever shaft 120 about which it. is normally biased in a clockwise direction (as. viewed iny Fig. 3B) by a spring 122 connecting the upper end of the bell crank trip lever 118 with a casing 124 in which the bell crank assembly is located. The bell crank trip lever 118 is generally L-shaped and has an inwardly extending leg 126, which at its free end has a downwardly extending finger 128, adapted to engage a latch point 130 at the lower end of the bell crank latch 104. While the finger 128 and the latch 130 are engaged, as shown in Fig. 3B,. the bell crank latch 104 will be in its retracted position against the tension of the spring 116. The power shaft 96 is constantly rotated by a suitable electric motor and..

. therefore, the drive plate 98 also rotates constantly. So

long as the bell crank latch 104 is in its retracted position, the pins and 102 of the associated drive plate 98 will rotate freely in respect to the bell crank 92. In this connection, it should be noted that the pins 100 and 102 extend into proximity with the face of the bell crank 92A such that if the bell crank latch 104 is released, its lower free end 130 will be engaged by either of the pins 100 or 102 with the result that the bell crank 92 will be driven in a clockwise direction (as viewed in Fig. 3B) about the bell crank shaft 90.

As the drive pin 102 (for example) is rotated ina clockwise direction, its contact with the free end of the bell crank 104 will result in a clockwise movement of the bell crank 92 about the bell crank shaft 90. This movement will continue until the slot formed between. lug 112 and the end of the guide plate 106 coincides with the path of the drive pin 102. At this moment, the drive pin 102 will enter the slot and pass freely to the point where it contacts the lug 110. When the lug is engaged by the drive pin 102, the segment 92 will be rocked back to its original position.

When the shift segment 92 is operated, the link 94will transmit power to a link 132 which is mounted for free rotation on the intermediate shift-shaft 88. Associated with the link 132 is a mechanism which-is keyed to the intermediate shift-shaft 88 and which is adapted to rotate the intermediate shift-shaft 88 when operated by the link 132. This mechanism is, is effect, a flanged sleeve 134 (Fig. 8) which is keyed to the intermediate shiftshaft 88 by means of a pin 136. The sleeve 134 hasa pair of flanges projecting therefrom. A ange 138. is located in proximity to the link 132 and has a stud 140 projecting1 inwardly from the face thereof. The. stud' 140 lies in the vertical plane of the link 132 and isadapted to register with a notch 142 (Fig. 3B) which is formed in the upper edge of the linf. 132. When the shift mechanism is in the uppercase position, the disposition of the elements just referred to is such that the stud 140 rests in the notch 142 so that when the link 132 is pulled forward by operation of the shift segment 92, the -sleeve 134 and consequently the intermediate shift-shaft 88 will be rocked in a counterclockwise direction which is effective to lower the platen supporting mechanism into lowercase printing position.

When the intermediate shift-shaft 88 is rocked to its clockwise position, the shift tape 84 which is attached to a pin 144, carried by a ange 146 atthe opposite end of the sleeve 134, will be pulled down with the result that the actuating plate 76 of Fig. 3A will be rotated in a clockwise direction, thus rotating the shift-shaft 80 in a clockwise direction to effect elevation of the platen support plates into uppercase printing position. When the shift segment 92 is operated, the link 94 will be pulled forwardly with the result that the link 132 will engage the stud 140, if the stud is in its lower position at this time, thereby rocking the intermediate shift-shaft 88 in a counterclockwise direction. This, in effect, relieves the tension on the shift tape 84 and applies tension to the shift tape 86, as seen in Fig. 11. Tension of the shift tape 86 will rotate the plate 82 and consequently the upper shift-shaft 80 in a counterclockwise direction. The result of this is that the platen support plates are lowered into lowercase printing position.

The shift segment and associated mechanism for operating the intermediate shift-shaft 88 in a clockwise direction is in all respects the same as that described in connection with the lowercase shift mechanism with the exception that a link 148 of Fig. ll, which is the counterpart of the link 132 of Figs. 3B, 7 and 8 is oppositely mounted on the intermediate shift-shaft 88 and the link, corresponding to the link 94, connecting it to the uppercase shift segment is extended to the front of the intermediate shift-shaft 88 such that the link 148 is pulled about the intermediate shift-shaft 88 in a clockwise direction.

The fact that the shift tapes 84 and 86 each has an end thereof connected to a point in the base of the printer which is fixed in the horizontal direction and the other ends thereof connected to points in the carriage, which is movable in a horizontal direction, demands mechanism for keeping these tapes under constant tension at all times. The mechanism for the stated purpose is shown in the diagrammatic representation of Fig. 11 and the detailed nature thereof is more particularly illustrated in Figs. 9 and 10. In Fig. 11, it will be seen that the tension of the tape 84 is controlled by a pentagraph lever 150 while the tension of the tape 86 is controlled by an identical lever 152. As the carriage moves from right to left, for example, tension on the tape 86 tends to increase while tension on the tape 84 tends to decrease. Compensation of this condition is provided by the relative shortening of the pentagraph lever 152 and the relative elongation of the pentagraph lever 150. A consideration of these functions will become clear by reference to Fig. 10 which shows the details of the lever 150.

The lever 150, which is typical of both such levers employed, comprises a long arm 154, which is pivoted on the base 30 of the printer and a short curved arm 156, which is pivoted to the free end of the long arm 154. The end of the short arm 156, which is distant from its connection to the long arm 154, is pivoted to the underside of the carriage 10 by means of a pivot pin 158. The pivot pin 158 also supports a guide pulley 160 directly under the adjacent end of the short arm 156. There is also a guide pulley 162 on a pin 164 which connects the arms 154 and 156. A pin 166 by means of which the arm 154 is mounted on the base ,30 also supports a guide pulley 168. The shift taper84 is trained upwardly from the pin 144 (Fig. 3B) about a series of guide pulleys including the pulleys 160,162, 168 and 170. This shift tape also passes about a guide pulley-.172

mounted on a pin 174 extending downwardly from the will first be shifted to the right and as the printing ofa.- line proceeds, the `parts move progressively to the leftv and will assume the dotted line position of Fig. 10 by the time the carriage approaches-its left hand position. A study of Fig. 10 will indicate that as the arms 154 and 156 rotate about their respective pivot points 166 and 158 into the dotted line position, the short arm 156 will assume an extended position in respect to the long arm 154 and thereby maintain shift tape tension to compensate for change of carriage position.

What is claimed is:

1. In a typewriter, a base structure having a pair of opposite side walls, a transverse guide track mounted in said side walls, a carriage having a pair of opposite end walls, a transverse guide track mounted in said end walls, a truck having bearing surfaces embracing said guide tracks whereby said carriage is mounted on said base structure for transverse movement in respect thereto, a pair of tape guides extending laterally in opposite directions from said truck, separate truck-control tapes trained about each of said tape guides, one of said tapes having one of its ends fixedto one of said base side walls and the other end to the adjacent carriage end wall, and the other of said tapes having one of its ends fixed to the other of said base side walls and the other lend to the adjacent carriage end wall. l

2. In a typewriter, a base structure having a pair'of opposite side walls, a pair of transverse guide rods mounted in said side walls, a carriage having a pair of opposite end walls, a pair of transverse guide rods mounted in said end walls, a truck having bearing surfaces embracing said pairs of guide rods whereby said carriage is mounted on said base structure for transverse movement in respect thereto, a pair of tape guides extending laterally in opposite directions from said truck, separate truck-control tapes trained about each of said tape guides, one of said tapes having one of its ends fixed to one of said base side walls and the other end to the adjacent carriage end wall, and the other of said tapes having one of its ends fixed to the other of said base side Walls and the other end to the adjacent carriage end wall.

3. In a typewriter, a base structure having a pair of opposite side walls, a transverse guide track mounted in said side walls, a carriage having a pair of opposite end walls, a transverse guide track mounted in said end walls in such position that the track is disposed in a plane parallel to said first named track and spaced therefrom in a vertical direction, a truck having bearing surfaces embracing said pairs of guide rods whereby said carriage is mounted on-said base structure for transverse movement in respect thereto, a pair of tape guides extending laterally in opposite directions from said truck, separate truck-control tapes trained about each of said tape guides, one of said tapes having one of its ends fixed to one of said base side walls and the other end to the adjacent carriage end wall, and the other of said tapes having one of its ends fixed to the other of said base side walls and the other end to the adjacent carriage end wall.

4. In a typewriter, a base structure having a pair of opposite side walls, a pair of transverse guide rods mounted in said side walls, a carriage having a pair of opposite l, en'd walls, a pair of transverse guide rods mounted in said end walls' in such position that said guideY rods are disposed in a plane parallel to` said first pair of guide rods and spaced therefrom in a` Vertical direction, a truck: havingbearing. surfaces embracing said pairs of guide rods whereby said carriage is mounted on said base structure for transverse movement in respect thereto, a pair of tape guides extending laterally in opposite directions from said truck, separate truck-control tapes trained about each of said tape guides, one of said tapes having one of: its ends iixed to one of said base side Walls and the other endfto the adjacent carriage end Wall, and the other of said tapes having one of its ends fixed to the other of said base side Walls and the other end to the adjacent carriage end wall.

5. In a typewriter, a base structure having a pair of opposite side Walls, a pair of transverse 'guide rods mounted in said side Walls, a carriage having a pair of opposite end walls, a lpair ,of transverse guide rods mounted in said end walls,- a truck having a pair of bearing surfaces each consisting. of a pair of sleeves embracing said pairs of guide rods whereby said carriage is mounted on said hase strueturefor transverse movement in'` respect thereto, a pair of tape guides extending laterally in: opposite directions from said truck, separate truck-control tapes: trained about each. of said tape guides, one of said tapes having one of its ends txed to one of said base side walls and the other end to the adjacent carriage end wall, and the other of'said tapes having one 0fits` ends fixed to the other of said base side walls am1 the other end to the adjacent carriage end Wall.

No references cited.

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