US3608688A

US3608688A - Paragraph indentation mechanism for typewriters

Info

Publication number: US3608688A
Application number: US778489A
Authority: US
Inventors: Yukio Hishida; Toshio Nakai
Original assignee: Brother Industries Ltd
Current assignee: Brother Industries Ltd
Priority date: 1967-11-25
Filing date: 1968-11-25
Publication date: 1971-09-28
Anticipated expiration: 1988-09-28

Abstract

A paragraph indentation mechanism for a typewriter which has an escapement mechanism for controlling the letter-spacing movement of the carriage and which includes a rack mounted on the carriage and also a member pawl mounted on a frame for both pivotal and limited sliding movement in a carriage traveling direction. A special key is operatively connected to the member pawl and the escapement mechanism for engaging the member pawl with the rack and then disabling the escapement mechanism so as to move the carriage with the member pawl. By this mechanism, the carriage is moved in a letter-spacing direction a number of spaces, for example five, from any position where the carriage is retained by the escapement mechanism.

Description

United States Patent Inventors Yukio Hishida;

Toshio Nakai, both of Nagoya, Japan Appl. No. 778,489 Filed Nov. 25, 1968 Patented Sept. 28, 1971 Assignee Brother Industries Ltd.

Nagoya, Japan Priority Nov. 25, 1967 Japan PARAGRAPHINDENTATIONMECHANISM FOR TYPEWRITERS 11 Claims, 6 Drawing Figs.

US. Cl 197/82, 197/176 Int. Cl B41j19/00 Field 01 Search 197/60, 63,

[56] References Cited UNITED STATES PATENTS 728,170 5/1903 Joerissen 197/178 864,601 8/ 1907 Blickensderfer 197/66 UX 1,132,558 3/1915 Carlin 197/176 1,806,082 5/1931 Resch 197/176 2,893,532 7/1959 Heinze 197/84 Primary ExaminerErnest T. Wright, Jr. Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak ABSTRACT: A paragraph indentation mechanism for a typewriter which has an escapement mechanism for controlling the letter-spacing movement of the carriage and which includes a rack mounted on the carriage and also a member pawl mounted on a frame for both pivotal and limited sliding movement in a carriage traveling direction. A special key is operatively connected to the member pawl and the escapement mechanism for engaging the member pawl with the rack and then disabling the escapement mechanism so as to move the carriage with the member pawl. By this mechanism, the carriage is moved in a letter-spacing direction a number of spaces, for example five, from any position where the carriage is retained by the escapement mechanism.

PATENTEU SEP28 l97| SHEET 0F 6 FIG.

Human swam 3308.688

- SHEU 5 (IF 6 mechanism for a typewriter, and in particular to a paragraph indentation mechanism for controlling the movement of the carriage in the letter-spacing direction in order to increase the typing rate of the operator.

2. Description of the Prior Art When a document is typed, it is a common practice to initially set the position of the beginning and the end of a line with a pair of margin stop means disposed on the rightlefthand sides of the typewriter. It is also a common practice when starting a new paragraph to begin to type after leaving several blank spaces at the beginning of the lines. The number of blank spaces is usually five or ten from the beginning position of the line. The appearance of the typed document is enhanced by leaving several blank spaces, usually five, at the end of a sentence on the same line before beginning the subsequent sentence.

In making the above-described spaces at the beginning of the line, the carriage is advanced to the desired position by repeatedly pushing down on the space bar present in the conventional typewriter. If the typewriter is provided with a repeat-spacing mechanism, it is necessary to keep pushing down the repeat space key until the carriage is advanced the desired number of spaces.

The prior art as described above has several disadvantages which will now be discussed. The conventional method of repeatedly pushing down on the space key is an action which is troublesome and slow. It is also difficult to get the precise spacing desired because each advancing movement of the carriage has to be carefully counted by the operator. And even if the typewriter is provided with tabulating mechanism, it is impossible to stop the carriage at a position where the carriage is moved several spaces from any position where the carriage is retained by an escapement mechanism although the carriage can be stopped at a position predetermined by the setting of a selected tabulating stop.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mechanism for controlling the carriage of a typewriter so that a beautifully typed document can be rapidly obtained.

Another object of the present invention is to provide a paragraph indentation mechanism for controlling the movement of the carriage so that in order to move the carriage a fixed distance corresponding to several spaces from any optionally stopped position, where the carriage is retained by a normal escapement mechanism it is only necessary to push down on a single special key. A further object of the present invention is to provide a paragraph indentation mechanism which can be adapted to the conventional typewriter and which is completely different from the escapement mechanism used for advancing the carriage step-by-step and also different from the tabulating mechanism used for running the carriage to the predetermined stop position set by the tabulating stop.

A still further object of the present invention is to provide a paragraph indentation mechanism which is of simple construction, low cost, and is very efficient.

Other objects will become apparent from the following description and claims taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a side elevational view, partly in section, showing a paragraph indentation mechanism constructed in accordance with the principles of the present invention;

FIG. 2 is a top plan view, with parts broken away and parts in section, of the mechanism shown in FIG. 1;

FIG. 3 is an enlarged top plan view of a portion of the apparatus shown in FIG. 2;

FIG. 4 is an enlarged front elevational view of a portion of the apparatus shown in FIGS. I and 2; and

FIGS. 5 and 6 are enlarged top plan views of a portion of the apparatus shown in FIG. 2, showing the sliding member in positions out of engagement with and in engagement with the rack, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing illustrating an embodiment of the present invention, the reference numerals I0 and 11 denote opposite side frames. A carriage 12 is disposed at the rear portion of the side frames 10,11. A plurality of keys 13 are arranged on the keyboard and disposed at the front side of the side frames 10, 11. A fixed rail 15 is secured to the lateral frame plate 14 and extends between the opposite side frames 10, 11 and a movable rail 16 is guided by the fixed rail 15 and slidably supports the carriage l2 thereon. The carriage 12 is provided with a platen 18 supported at the opposite ends thereof by a sideplate 17. Reference numeral 19 denotes a spring drum serving as a spring means for normally urging the carriage 12 in the letter-spacing direction which would be leftward as viewed in FIG. 2.

Numeral 20 denotes a rack disposed in the longitudinal direction of the carriage 12 and fixed to the movable rail 16. The pitch of the teeth formed on one side of the rack 20 is identical to one space, the length of which space is equal to the distance the carriage 12 moves when one key 13 is depressed. Numeral 21 denotes a pinion which is in meshing engagement with the teeth of rack 20. A shaft 22 is rotatably mounted on frame 23 and said pinion 21 is secured tothe upper end of the shaft 22. Numeral 24 denotes an escapement wheel fixed to the lower end of the rotatable shaft 22. The escapement wheel 24 is normally urged to rotate in the counterclockwise direction as viewed in FIG. 4 by means of the spring of the spring drum 19 through the pinion 2I. The peripheral teeth of the escapement wheel 24 are spaced such that the rack 20 is moved by one pitch when the escapement wheel 24 is rotated by one tooth. A holding pawl 25 is normally in engagement with the escapement wheel 24 and functions to prevent the escapement wheel 24 from being rotated by the spring means 19 and for holding the carriage 12 a the optional position. Numeral 26 denotes a feeding pawl normally disposed out of rotational range of the escapement wheel 24. The holding pawl 25 and feeding pawl 26 are pivotally mounted under the force of spring 9 a common pivot 27 so that they can be rotated in a plane parallel to the plane in which the escapement wheel 24 rotates. Holding pawl 25 and feeding pawl 26 are rotated about the pivot 27 in a fixed relation to each other by means of a stopper 28 and spring 29 so as to alternately engage the escapement wheel 24 and make the escapement wheel 24 rotate intermittently as a result of the force of spring means 19 said stopper 28 is secured to the feeding pawl 26 and said spring 29 is anchored to the holding pawl 25 and the feeding pawl 26.

Thus, an escapement mechanism is set forth for advancing the carriage 12 in the letter spacing direction by one space from an optional typing position by the

pawls

25 and 26 in cooperation with the escapement wheel 24 and the relative interconnected connected thereto in response to the typing or spacing operation. In the typing or spacing operation the actuating lever 30 is pivotally mounted at a pivot axis 52 secured to the frame 23 and adapted to engage with a pin 53 secured to the feeding pawl 26 so as to actuate the feeding pawl 26.

Lever 54 is pivotally mounted at a pivot 55 on the holding pawl 25 and the pivotal movement of the lever 54 is limited to a fixed extent by two stop 25a and 25b secured to the holding pawl 25. To the lever 54 and the holding pawl 25 is anchored a spring 56 by which the lever 54 is normally urged counterclockwise in FIG. 4.

When the lever 54 is in a position released from the escapement wheel 24, the spring 56 urges the lever 54 and holds the same in a position in engagement with the stop 25a. When the lever 54 engages the escapement wheel 24, the lever 54 is rocked clockwise against the spring 56 by the escapement wheel 24 in FIG. 4 until the lever 54 engages the stop 25b wherein the shock of engagement with the lever 54 and escapement wheel 24 is absorbed.

The holding pawl 25 is independently rotatable in the clockwise direction as viewed in the broken line in FIG. 4 so that the pawl 25 can be disengaged from the escapement wheel 24 in order to free the escapement wheel 24 and permit the carriage 12 to be released from the escapement mechanism. That is, by disengaging the holding pawl 25 from the escapement wheel 24, the escapement mechanism is disabled and the carriage 12 can rapidly advance in the letterspacing direction by means of the spring means in the drum 19. The reference numeral 31 denotes an intermediate lever rotatably mounted at an axis 57 beneath the surface of the lateral frame plate 24 and rockable in a plane parallel to that of the lateral frame plate 14. The intermediate lever 31 has two arms 31a, 3112, one arm 31a thereof being bent downward at the end thereof and in contact with one side of the holding pawl 25 whereas the other arm 31b is bent upward at the end thereof and which bent end is projected upward through a round opening 32 provided in the lateral frame 14. As can be best seen in Flg. 4, the holding pawl 25 can be disengaged from the escapement wheel 24 by the arm 3111 which rotates with the intermediate lever 31.

The reference numerals 33 and 34 denote carriage release keys. The release key 33 is located in one side of the carriage l2 and is connected through connecting levers 58, 59 and 60 to a releasing bar 35 disposed longitudinally relative to the carriage 12. The lever 58 is mounted on the sideplate 17 for vertically sliding movement along a pin 61 which is secured to the sideplate 17 and is inserted in a slot 58a formed in the lever 58. The lever 59 is rotatably mounted on the side plate about a pivot 62 secured to the sideplate l7 and is connected to the lever 58 by a pivot 63. To the pivot 63 and the pin 61 is anchored a spring 64 which normally urges the lever 58 to a normal position shown in full line in FIG. 1. The lever 60 is rotatably mounted on the sideplate 17 about a pivot 65 secured to the sideplate 17, one end of the lever 60 being connected to the lever 59 and the other secured to the releasing bar 35. To the lever 60 is anchored a spring 66 to rock the lever 60 counterclockwise in FIG. 1. The release key 34 is located in the other side of the carriage l2 and is connected through connecting levers having the same shapes as levers 58, 59, and 60, which are not shown in the drawing to the releasing bar 35 and is conditioned as well as the key 33. When the key 33 or 34 is depressed from the normal position, the levers 58, 59 and 60 are moved to the positions indicated by the broken line in FIG. 1 and as the result of this movement the releasing bar 35 is laterally moved. The releasing bar 35 is in contact at the central portion thereof with the projecting arm 31b which projects out of the intermediate lever 31. The releasing bar 35, when moved laterally, moves the arm 31b and rotates the intermediate lever 31, so that the other arm 31a disengages the holding pawl 25 from the escapement wheel 24.

The reference numeral 36 denotes a pawl member having at one end thereof an engaging portion 36a which is formed by bending the end of the pawl member 36 to permit it to engage with the rack 20. Numeral 37 denotes an elongated slot provided on the

pawl member

36, and 38 denotes a pivot pin fixed on the lateral frame 14 for supporting the pawl member 36 and to permit it to slide in a plane parallel to that of the lateral frame plate 14. Numeral 39 denotes a spring for normally urging the pawl member 36 to rock in the clockwise direction as viewed in FlG. and for urging the pawl member 36 to the initial position where the pivot pin 38 is positioned at the end of the elongated slot 37. In this initial position, the engaging portion 36a of pawl member 36 cannot engage the rack 20.

The reference numeral 40 denotes a rockable member which is mounted on a pivot axis 67 fixed beneath the lateral to the rockable member 40 and projects upward through the fan-shaped opening 43 provided on the lateral plate 14 and engages one side edge of the paw member 36 so as to hold the pawl member 36 in its initial position against the force of spring 39. The pin 42 forces the engaging portion 36a of the pawl member 36 into engagement with the rack 20 in response to the rocking of the rockable member 40 as viewed in FIG. 6. The rockable member 40 has a projection 40a thereon which is normally spaced from the arm 31a of the intermediate lever 31 and is brought into engagement with the arm 31b in response to the rotation of the rockablemember 40 as viewed in FIG. 6, whereby the intermediate lever 31 is rocked and the holding pawl 25 is disengaged from the escapement wheel 24 to disable the escapement mechanism.

The timing at which the projection 40a disables the escapement mechanism in response to the rocking movement rockable member 40 through the intermediate lever 31, is set to be after the pawl member 36 is completely engaged with the rack 20 by the pin 42. That is to say, the rockable member 40 has the effect of bringing the pawl member 36 to a position where it is engaged with the rack 20 and also the effect of a acting on the intermediate lever 31 at the arm 31b to disable the escapement mechanism. The two aforementioned effects are obtained with a time lag accompanying the rotation of the members other words, the rockable member 40 is engaged with the pawl member 36 and the intermediate lever 31 so that the escapement mechanism is disabled by the intermediate lever 31 so that the escapement mechanism is disabled by the intermediate lever 31 after completion of the engagement of the pawl member 36 and the rack 20. When the carriage 12 is freely advanced in the letter-spacing direction 9 from the optional typing position by the above-mentioned effect of disabling the escapement mechanism the pawl member 36 is also moved against the force of the spring 39 in meshing engagement with the rack 20 at the engaged positioned by the above first mentioned effect. The pawl member 36 is capable of being moved linearly a definite length determined by the relation of the pivot pin 38 and the slot 37, and this makes the carriage 12 stop at the position indicated in the broken line in H6. 6. The above-described definite length is the distance by which the pivot pin 38 is permitted to move from one end of the elongated slot 37 to the other end thereof. The length is made 4% pitch of the rack 20 in the embodiment shown in the drawing. Therefore, the carriage 12 is advanced by 4% spaces from the optional typing position where the carriage is retained by the escapement mechanism.

When the rockable member 40 is rerocked to the position shown in FlG. 5 from the position shown in FIG. 6, the projection 40a releases the intermediate lever 31 which first engages the holding pawl 25 engage the through the arm 31a and causes the pawl 25 through the arm 31a and causes the pawl to engage the escapement wheel 24 to enable the escapement mechanism, and then the upward movement of the pin 42 allows pawl member 36 to be moved away from the rack 20 under the force of the spring 39 thereby moving the pawl member 36, back to its initial position. in the above operation, until the holding pawl 25 is completely engaged with the teeth of the escapement wheel 24, the carriage 12 is advanced by one-half space in the letter-spacing direction. Therefore, the carriage 12 is advanced a total of five spaces in the letter-spacing direction. The reference numeral 44 denotes a special key, which has a key lever 45 pivotally mounted at a pivot 68 on the frame 10. The key lever 45 is urged counterclockwise by a spring 69 about the pivot 68 in Fig. l and is held in a normal position indicated by the full line in FIG. 1 by a stop, which is not shown, against force of the spring 69.

Numerals 46 through 51 denote members which constitute an interconnecting lever mechanism for transmitting the movement of the key lever 45, caused by depression of the special key 44, to rotating member 40.

The bellcrank lever 46 is pivotally mounted at a pivot 70 on the frame 10 and is urged counterclockwise, in FIG. 1 about the pivot 70 by a spring 71, one arm of the lever 46 being engaged with a pin 72 secured to the key lever 45, the other arm of the lever 46 being connected to one end of the link 47.

The lever 48 is pivotally mounted at a pivot 73 on the frame 10, one arm of the lever 48 being connected to the other end of the link 47, the other arm of the lever 48 being connected to one end of the link 49.

The bellcrank lever 50 is pivotally mounted at a pivot 74 on a plate 75 secured to the rear frame 76, one arm of the lever 50 being connected to the other end of the link 49, the other arm of the lever 50 being connected to one end of the link 51. The other end of the link 51 is connected to the rockable member 40.

The above interconnecting lever mechanism 46-51 acts as a means for interconnecting the special key 44 with the rockable member 40, when the special key 44 is depressed from the normal position to a position indicated by the dotted line in Fig. 1.

As a result of this movement, bellcrank lever 50 is rocked counterclockwise, in FIG. 2 about the pivot 74 through the link 49 to pull the link 51 so that the rockable member 40 is rocked counterclockwise to the position shown in H0. 5 about the pivot axis 67 against the spring 41.

By releasing the special key 44, the rotating member 40 is moved back to the initial position shown in FIG. 5 through the interconnecting lever mechanism 46-51.

As described above, the rockable member 40 is rocked counterclockwise as shown in FIG. 6 by depressing the special key 44 through the interconnecting lever mechanism 46-51.

By this rocking movement, the pawl member 36 is engaged with the rack 20 and with a time lag, in other words, with lostmotion connection, the intermediate lever 31 is rocked to engage the holding pawl 25.

The escapement mechanism is disabled soon after the pawl member 36 is engaged with the rack 20, whereby the carriage 12 is rapidly advanced by five spaces in the letter-spacing direction from the optional typing position where the carriage 12 is retained by the escapement mechanism. When the controlling key 44 is released, the carriage 12 is again retained by the escapement mechanism enabled at the advanced position represented by five spaces. The five spaces by which the carriage 12 is freely advanced corresponds to an average of one word in the embodiment, but the spacing can be optionally selected by varying the design of the length of the elongated slot 37 of the sliding member 36 or the radius of the pivot pin 38.

As can be seen, the present invention permits the carriage 12 to be positively and rapidly advanced a definite several spaces from an optional typing position where the carriage is retained by the escapement mechanism, by merely depressing a single special key 44 as described herein above. This is very convenient and efiective when a definite space is required to be provided in a line or a definite space is required at the beginning of a line before actual typing begins. Therefore, the typing work can be done rapidly and its overall appearance enhanced. Also the paragraph indentation mechanism as described above in accordance with the present invention is simple and compact, and can be made at low coast because the parts necessary for embodying the present invention are few and these pans, such as the rockable member 40, the pawl member 36 and the intermediate lever 31 are constructed in a narrow space with parallel relation to the lateral frame plate 14.

Therefore, the paragraph indentation mechanism of the present invention cannot only be adapted to high-class business typewriters, but also to compact portable typewriters.

We claim:

I. A paragraph indentation mechanism for a typewriter having a keyboard comprising, in combination:

a frame having a lateral frame plate,

a carriage rail mounted on the lateral frame plate,

a carriage movably mounted on the rail and normally biased in a letter-spacing direction,

a rack mounted on the carriage and extending in a carriagetravelling direction,

an escapement mechanism operatively connected to the rack for controlling a step-by-step letter-spacing movement of the carriage in the letter-spacing direction,

a pawl member supported on the lateral frame plate for rocking movement into engagement with the rack and for sliding movement in the carriage-travelling direction,

means to limit the sliding movement of the pawl member to a limited extent corresponding to several letter spaces of the letter-spacing movement of the carriage,

spring means for urging pawl member in a direction opposite to the letter-spacing direction and for rocking the pawl member in a direction out of engagement with the rack,

movable abutment means in engagement with the pawl member to limit the racking movement thereof by the spring means, and

manually operable means operatively connected to the abutment means for rocking the pawl member into engagement with the rack against the force of the spring means, said manually operable means being further operatively connected through a lost-motion connection to the escapement mechanism for disabling the escapement mechanism after the pawl member is engaged with the rack,

whereby the carriage is moved several spaces in the letterspacing direction from any position where the carriage is retained by the escapement mechanism.

2. A paragraph indentation mechanism for a typewriter as defined in claim 1, wherein said limiting means includes an elongated slot formed in the pawl member, and a pin secured to the lateral frame plate and passing through the slot, said pin being engaged with one end of the slot when the pawl member is in the disengaged position, and said pawl member is rocked about the pin by the manually operable means.

3. A paragraph indentation mechanism for a typewriter as defined in claim 1, wherein said manually operable means includes a rockable member rockably mounted on the lateral frame plate and supporting said abutment means for engagement with the pawl member when the rockable member is rocked, said rockable member having a second portion which is operatively connected to the escapement mechanism when the rockable member is rocked, and wherein a special key is mounted on the keyboard and is depressible from a normal position, and an interconnecting mechanism connects the special key to the rockable member for rocking the rockable member when the special key is depressed.

4. A paragraph indentation mechanism for a typewriter having a keyboard comprising, in combination:

a frame having a lateral frame plate,

a carriage rail mounted on the lateral frame plate,

a rack mounted on the carriage and extending in a carriagetravelling direction,

means to limit the sliding movement of the pawl member to a limited extend corresponding to several letter spaces of the letter-spacing movement of the carriage,

spring means for urging the pawl member in a direction opposite to the letter-spacing direction and for rocking the pawl member in a direction out of engagement with the rack,

a rockable member pivotally secured to the lateral frame plate and rockable between an inoperable and an operable position for moving the pawl member into engagement with the rack against the force of the spring means, means for normally urging the rockable member toward the inoperable position,

said rockable member having a pin secured thereon which is engaged with the pawl member to limit the rocking movement thereof by said spring means when the rockable member is in the inoperable position, and having a portion operatively connected through a lost-motion connection to the escapement mechanism for disabling the escapement mechanism after the pawl member is engaged with the rack,

a special key mounted on the keyboard and depressible from a normal position, and

an interconnecting lever mechanism for connecting the special key to the rockable member for rocking said rockable member to the operable position when the special key is depressed,

whereby the carriage is moved several spaces from any position where the carriage is retained by the escapement mechanism.

5. A paragraph indentation mechanism for a typewriter as defined in claim 4, wherein said rocking and sliding movement of the pawl member and said rocking movement of the rockable member are in a plane parallel to that of the lateral frame plate.

6. A paragraph indentation mechanism for a typewriter as defined in claim 4, wherein said pin on the rockable member extends from one side edge thereof, and the pin serves to maintain the pawl member in engagement with the rack against the force of said spring means while the special key is depressed.

7. A paragraph indentation mechanism for a typewriter having a keyboard comprising, in combination:

a frame having a lateral frame plate,

a carriage rail mounted on the lateral frame plate,

a carriage movably mounted on the rail and normally biased in a letterspacing direction,

a rack mounted on the carriage and extending in a carriagetravelling direction,

an escapement mechanism operatively connected to the rack for controlling a step-by-step letter-spacing movement of the carriage in the letter-spacing direction, said escapement mechanism including a toothed member and a pair of pawls rockably mounted on the later frame plate to engage alternately with the toothed member, one of said pawls being a holding pawl normally engaged with the toothed member and the other being a feeding pawl normally disengaged from the toothed member,

a pawl member supported on the lateral frame plate for rocking movement into engagement with the rack and for sliding movement in the carriage-travelling direction means to limit the sliding movement of the pawl member to a limited extent corresponding to several letter spaces of the letter-spacing movement of the carriage,

movable abutment means in engagement with the pawl member to limit the rocking movement thereof by the spring means,

a rockable member pivotally secured to the lateral frame plate and rockable between an inoperable and an operable position for moving the pawl member into engagement with the rack against the force of said spring means, means for normally urging the rockable member to the inoperable position,

an intermediate lever pivotally secured to the lateral frame plate and located between the escapement mechanism and the rockable member,

said rockable member in the operable position being operatively engaged with the intermediate member to move it into engagement with the holding pawl, thereby to disengage the holding pawl from the toothed member after the rockable member moves the pawl member into engagement with the rack,

a interconnecting mechanism for connecting the special key to the rockable member for moving the rockable member from the inoperable position to the operable position when the special key is depressed, whereby the carriage is moved several spaces in the letterspacing direction from any position where the carriage is retained by the escapement mechanism. 8. A paragraph indentation mechanism for a typewriter having a keyboard comprising, in combination:

a frame having a lateral frame plate,

a carriage rail mounted on the lateral frame plate,

a carriage movable mounted on the rail and normally biased in a letter-spacing direction,

a rack mounted on the carriage and extending in a carriagetravelling direction,

an escapement mechanism operatively connected to the rack for controlling a step-by-step letter-spacing movement of the carriage in the letter-spacing direction, said escapement mechanism including a toothed member and a pair of pawls rockably mounted on the lateral frame plate to engage alternately with the toothed member, one

- of said pawls being a holding pawl normally engaged with the toothed member and the other being a feeding pawl normally disengaged from the toothed member,

a pawl member supported on the lateral frame plate for rocking movement into engagement with the rack and for sliding movement in the carriage-travelling in the said rocking and sliding movement of said pawl member being in a plane parallel to that of the lateral frame plate,

means to limit the sliding movement of the pawl member to a limited extent corresponding to several letter spaces in the letter-spacing movement of the carriage,

rockable member pivotally secured to the lateral frame plate and rockable in a plane parallel to that of the lateral frame plate between an inoperable and an operable position for moving the pawl member into engagement with the rack against the force of said spring means, means for normally urging said rockable member to the inoperable position,

a two-armed lever pivotally secured to the lateral frame plate and rockable in a plane parallel to that of the lateral frame plate, one arm of said lever being engaged with said holding pawl of the escapement mechanism,

said rockable member having a pin secured thereon which is engaged with the pawl member and limits the rocking movement thereof by said spring means when the rockable member is in the inoperable position, and having a portion engageable with another arm of the two-armed lever, said portion being spaced from the other arm of the two-armed lever when the rockable member is in the inoperable position and and being engaged with other arm of the two-armed lever when the rockable member is rocked from the inoperable position to the operable position,

said two-armed lever being rocked by engagement of said portion and said other arm thereof for causing the one arm thereof to move the holding pawl out of engagement with the toothed member, thereby to disable the escapement mechanism after the pawl member is engaged with the rack,

an interconnecting mechanism for connecting the special key to the rockable member for moving the rockable member from the inoperable portion to the operable posi tion when the special key is depressed,

9. A paragraph indentation mechanism for a typewriter hava frame having a lateral frame plate,

a carriage rail mounted on the lateral frame plate,

a rack mounted on the carriage and extending in a carriagetravelling direction,

an escapement mechanism operatively connected to the rack for controlling a step-by-step letter-spacing movement of the carriage in the letter-spacing direction, said escapement mechanism including an escapement wheel; a wheel and a pair of pawls pivotally mounted on the lateral frame plate to engage alternately with the escapement wheel, one of said pawls being a holding pawl normally engaged with the escapement wheel and the other being a feeding pawl normally disengaged from the escapement wheel,

a pawl member supported on the lateral frame plate for rocking movement into engagement with the rack and for sliding movement in the carriage-travelling direction, said rocking and sliding movement of the pawl member being in a plane parallel to that of the lateral frame plate,

means to limit the sliding movement of the pawl member to a limited extent corresponding to several letter spaces of the letter spacing movement of the carriage said limiting means including a long slot formed in the pawl member and a pin secured to the lateral frame plate passing through the slot,

a spring disposed between the pawl member and the lateral frame plate for urging the pawl member in a direction opposite to the letter-spacing direction toward one end thereof where said pin is engaged with one end of the slot and for rocking the pawl member in a direction out of engagement with the rack,

a rockable member pivotally secured to the lateral frame plate and rockable in a plane parallel to that of the lateral frame plate between an inoperable and an operable position for moving the pawl member into rocking engagement with the rack against the force of the spring,

means for normally urging said rockable member to the inoperable position,

a two-armed lever pivotally secured to the lateral frame plate and rockable in a plane parallel to that of the lateral frame plate, one arm of said two armed lever being engaged with said holding pawl of the escapement mechanism,

an interconnecting mechanism for connecting the special key to the rockable member for moving the rockable member from the inoperable position to the operable position when the special key is depressed,

10. A paragraph indentation mechanism for a typewriter having a keyboard comprising in combination:

a frame having a lateral frame plate,

a carriage rail mounted on the lateral frame plate,

a rack mounted on the carriage and extending in a carriagetravelling direction,

an escapement mechanism operatively connected to the rack for controlling a stepby-step letter-spacing movement of the carriage in the letter-spacing direction,

spring means for urging the pawl member in a direction opposite to the letter-spacing direction and for rocking the pawl member in a direction out of engagement with the rack meansin engagement with a pawl member to limit the rocking movement thereof by the spring means,

a special key mounted on the keyboard and depressible from a normal position,

a key-controlled means responsive to depression of the special key to as to move the pawl member into rocking engagement with the rack against the face of the spring means, to disable the escapement mechanism after completion of said engagement of the pawl member and the rack, thereby moving the pawl member with the rack, and to keep the pawl member in engagement with the rack while the pawl member is moved to the limit extent determined by the limiting means, said key-controlled means being responsive to release of the special key so as to effect engagement of the escapement mechanism with the rack to disengage the pawl member from the rack after completion of said engagement of the escapement mechanism,

11. A paragraph indentation mechanism for a typewriter as defined in claim 10, wherein said limiting means includes a long slot formed in the pawl member and a pin secured to the lateral frame plate passing through the slot, said pin being engaged with one end of the slot when the pawl member is in the disengaged position, and wherein said pawl member is rocked about the pin by said key-controlled means.

Claims

1. A paragraph indentation mechanism for a typewriter having a keyboard comprising, in combination: a frame having a lateral frame plate, a carriage rail mounted on the lateral frame plate, a carriage movably mounted on the rail and normally biased in a letter-spacing direction, a rack mounted on the carriage and extending in a carriagetravelling direction, an escapement mechanism operatively connected to the rack for controlling a step-by-step letter-spacing movement of the carriage in the letter-spacing direction, a pawl member supported on the lateral frame plate for rocking movement into engagement with the rack and for sliding movement in the carriage-travelling direction, means to limit the sliding movement of the pawl member to a limited extent corresponding to several letter spaces of the letter-spacing movement of the carriage, spring means for urging pawl member in a direction opposite to the letter-spacing direction and for rocking the pawl member in a direction out of engagement with the rack, movable abutment means in engagement with the pawl member to limit the rocking movement thereof by the spring means, and manually operable means operatively connected to the abutment means for rocking the pawl member into engagement with the rack against the force of the spring means, said manually operable means being further operatively connected through a lost-motion connection to the escapement mechanism for disabling the escapement mechanism after the pawl member is engaged with the rack, whereby the carriage is moved several spaces in the letterspacing direction from any position where the carriage is retained by the escapement mechanism.

4. A paragraph indentation mechanism for a typewriter having a keyboard comprising, in combination: a frame having a lateral frame plate, a carriage rail mounted on the lateral frame plate, a carriage movably mounted on the rail and normally biased in a letter-spacing direction, a rack mounted on the carriage and extending in a carriage-travelling direction, an escapement mechanism operatively connected to the rack for controlling a step-by-step letter-spacing movement of the carriage in the letter-spacing direction, a pawl member supported on the lateral frame plate for rocking movement into engagement with the rack and for sliding movement in the carriage-travelling direction, means to limit the sliding movement of the pawl member to a limited extend corresponding to several letter spaces of the letter-spacing movement of the carriage, spring means for urging the pawl member in a direction opposite to the letter-spacing direction and for rocking the pawl member in a direction out of engagement with the rack, a rockable member pivotally secured to the lateral frame plate and rockable between an inoperable and an operable position for moving the pawl member into engagement with the rack against the force of the spring means, means for normally urging the rockable member toward the inoperable position, said rockable member having a pin secured thereon which is engaged with the pawl member to limit the rocking movement thereof by said spring means when the rockable member is in the inoperable position, and having a portion operatively connected through a lost-motion connection to the escapement mechanism for disabling the escapement mechanism after the pawl member is engaged with the rack, a special key mounted on the keyboard and depressible from a normal position, and an interconnecting lever mechanism for connecting the special key to the rockable member for rocking said rockable member to the operable position when the special key is depressed, whereby the carriage is moved several spaces from any position where the carriage is retained by the escapement mechanism.

7. A paragraph indentation mechanism for a typewriter having a keyboard comprising, in combination: a frame having a lateral frame plate, a carriage rail mounted on the lateral frame plate, a carriage movably mounted on the rail and normally biased in a letter-spacing direction, a rack mounted on the carriage and extending in a carriage-travelling direction, an escapement mechanism operatively connected to the rack for controlling a step-by-step letter-spacing movement of the carriage in the letter-spacing direction, said escapement mechanism including a toothed member and a pair of pawls rockably mounted on the later frame plate to engage alternately with the toothed member, one of said pawls being a holding pawl normally engaged with the toothed member anD the other being a feeding pawl normally disengaged from the toothed member, a pawl member supported on the lateral frame plate for rocking movement into engagement with the rack and for sliding movement in the carriage-travelling direction means to limit the sliding movement of the pawl member to a limited extent corresponding to several letter spaces of the letter-spacing movement of the carriage, spring means for urging the pawl member in a direction opposite to the letter-spacing direction and for rocking the pawl member in a direction out of engagement with the rack, movable abutment means in engagement with the pawl member to limit the rocking movement thereof by the spring means, a rockable member pivotally secured to the lateral frame plate and rockable between an inoperable and an operable position for moving the pawl member into engagement with the rack against the force of said spring means, means for normally urging the rockable member to the inoperable position, an intermediate lever pivotally secured to the lateral frame plate and located between the escapement mechanism and the rockable member, said rockable member in the operable position being operatively engaged with the intermediate member to move it into engagement with the holding pawl, thereby to disengage the holding pawl from the toothed member after the rockable member moves the pawl member into engagement with the rack, a special key mounted on the keyboard and depressible from a normal position, and an interconnecting mechanism for connecting the special key to the rockable member for moving the rockable member from the inoperable position to the operable position when the special key is depressed, whereby the carriage is moved several spaces in the letter-spacing direction from any position where the carriage is retained by the escapement mechanism.

8. A paragraph indentation mechanism for a typewriter having a keyboard comprising, in combination: a frame having a lateral frame plate, a carriage rail mounted on the lateral frame plate, a carriage movable mounted on the rail and normally biased in a letter-spacing direction, a rack mounted on the carriage and extending in a carriage-travelling direction, an escapement mechanism operatively connected to the rack for controlling a step-by-step letter-spacing movement of the carriage in the letter-spacing direction, said escapement mechanism including a toothed member and a pair of pawls rockably mounted on the lateral frame plate to engage alternately with the toothed member, one of said pawls being a holding pawl normally engaged with the toothed member and the other being a feeding pawl normally disengaged from the toothed member, a pawl member supported on the lateral frame plate for rocking movement into engagement with the rack and for sliding movement in the carriage-travelling direction, said rocking and sliding movement of said pawl member being in a plane parallel to that of the lateral frame plate, means to limit the sliding movement of the pawl member to a limited extent corresponding to several letter spaces in the letter-spacing movement of the carriage, spring means for urging the pawl member in a direction opposite to the letter-spacing direction and for rocking the pawl member in a direction out of engagement with the rack, rockable member pivotally secured to the lateral frame plate and rockable in a plane parallel to that of the lateral frame plate between an inoperable and an operable position for moving the pawl member into engagement with the rack against the force of said spring means, means for normally urging said rockable member to the inoperable position, a two-armed lever pivotally secured to the lateral frame plate and rockable in a plane parallel to that of the lateral frame plate, one arm of said lever being engaged with said holding pawl of the escapement mechanism, said rockable member having a pin secured thereOn which is engaged with the pawl member and limits the rocking movement thereof by said spring means when the rockable member is in the inoperable position, and having a portion engageable with another arm of the two-armed lever, said portion being spaced from the other arm of the two-armed lever when the rockable member is in the inoperable position and and being engaged with other arm of the two-armed lever when the rockable member is rocked from the inoperable position to the operable position, said two-armed lever being rocked by engagement of said portion and said other arm thereof for causing the one arm thereof to move the holding pawl out of engagement with the toothed member, thereby to disable the escapement mechanism after the pawl member is engaged with the rack, a special key mounted on the keyboard and depressible from a normal position, and an interconnecting mechanism for connecting the special key to the rockable member for moving the rockable member from the inoperable position to the operable position when the special key is depressed, whereby the carriage is moved several spaces in the letter-spacing direction from any position where the carriage is retained by the escapement mechanism.

9. A paragraph indentation mechanism for a typewriter having a keyboard comprising, in combination: a frame having a lateral frame plate, a carriage rail mounted on the lateral frame plate, a carriage movably mounted on the rail and normally biased in a letter-spacing direction, a rack mounted on the carriage and extending in a carriage-travelling direction, an escapement mechanism operatively connected to the rack for controlling a step-by-step letter-spacing movement of the carriage in the letter-spacing direction, said escapement mechanism including an escapement wheel and a pair of pawls pivotally mounted on the lateral frame plate to engage alternately with the escapement wheel, one of said pawls being a holding pawl normally engaged with the escapement wheel and the other being a feeding pawl normally disengaged from the escapement wheel, a pawl member supported on the lateral frame plate for rocking movement into engagement with the rack and for sliding movement in the carriage-travelling direction, said rocking and sliding movement of the pawl member being in a plane parallel to that of the lateral frame plate, means to limit the sliding movement of the pawl member to a limited extent corresponding to several letter spaces of the letter spacing movement of the carriage said limiting means including a long slot formed in the pawl member and a pin secured to the lateral frame plate passing through the slot, a spring disposed between the pawl member and the lateral frame plate for urging the pawl member in a direction opposite to the letter-spacing direction toward one end thereof where said pin is engaged with one end of the slot and for rocking the pawl member in a direction out of engagement with the rack, a rockable member pivotally secured to the lateral frame plate and rockable in a plane parallel to that of the lateral frame plate between an inoperable and an operable position for moving the pawl member into rocking engagement with the rack against the force of the spring, means for normally urging said rockable member to the inoperable position, a two-armed lever pivotally secured to the lateral frame plate and rockable in a plane parallel to that of the lateral frame plate, one arm of said two armed lever being engaged with said holding pawl of the escapement mechanism, a special key mounted on the keyboard and depressible from a normal position, and an interconnecting mechanism for connecting the special key to the rockable member for moving the rockable member from the inoperable position to the operable position when the special key is depressed, whereby the carriage is moved several spaces in the letter-spacing direction from any position where the carriage is retained By the escapement mechanism.

10. A paragraph indentation mechanism for a typewriter having a keyboard comprising in combination: a frame having a lateral frame plate, a carriage rail mounted on the lateral frame plate, a carriage movably mounted on the rail and normally biased in a letter-spacing direction, a rack mounted on the carriage and extending in a carriage-travelling direction, an escapement mechanism operatively connected to the rack for controlling a step-by-step letter-spacing movement of the carriage in the letter-spacing direction, a pawl member supported on the lateral frame plate for rocking movement into engagement with the rack and for sliding movement in the carriage-travelling direction, means to limit the sliding movement of the pawl member to a limited extent corresponding to several letter spaces of the letter-spacing movement of the carriage, spring means for urging the pawl member in a direction opposite to the letter-spacing direction and for rocking the pawl member in a direction out of engagement with the rack, means in engagement with a pawl member to limit the rocking movement thereof by the spring means, a special key mounted on the keyboard and depressible from a normal position, a key-controlled means responsive to depression of the special key so as to move the pawl member into rocking engagement with the rack against the face of the spring means, to disable the escapement mechanism after completion of said engagement of the pawl member and the rack, thereby moving the pawl member with the rack, and to keep the pawl member in engagement with the rack while the pawl member is moved to the limited extent determined by the limiting means, said key-controlled means being responsive to release of the special key so as to effect engagement of the escapement mechanism with the rack to disengage the pawl member from the rack after completion of said engagement of the escapement mechanism, whereby the carriage is moved several spaces in the letter-spacing direction from any position where the carriage is retained by the escapement mechanism.