US2741355A - Floating escapement mechanism - Google Patents

Floating escapement mechanism Download PDF

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Publication number
US2741355A
US2741355A US359598A US35959853A US2741355A US 2741355 A US2741355 A US 2741355A US 359598 A US359598 A US 359598A US 35959853 A US35959853 A US 35959853A US 2741355 A US2741355 A US 2741355A
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US
United States
Prior art keywords
rack
pawl
carriage
movement
base
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US359598A
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English (en)
Inventor
Ronald D Dodge
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE529316D priority Critical patent/BE529316A/xx
Priority to DENDAT1073007D priority patent/DE1073007B/de
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Priority to US359598A priority patent/US2741355A/en
Priority to GB16302/54A priority patent/GB751170A/en
Priority to CH325481D priority patent/CH325481A/fr
Application granted granted Critical
Publication of US2741355A publication Critical patent/US2741355A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J19/00—Character- or line-spacing mechanisms
    • B41J19/18—Character-spacing or back-spacing mechanisms; Carriage return or release devices therefor
    • B41J19/34—Escapement-feed character-spacing mechanisms
    • B41J19/40—Escapements having a single pawl or like detent

Definitions

  • FIG. 2 RONALD D. DODGE ATTORNEY April 10, 1956 R. D. DODGE FLOATING ESCAPEMENT MECHANISM 2 Sheets-Sheet 2 Filed June 4. 1955 FIG. 2
  • This invention relates to a typewriter carriage spacing mechanism, and more particularly to a floating escapement mechanism for a typewriter carriage.
  • a carriage in conventional typewriter construction, is a device for holding a work sheet, and for moving the same in steps into a printing position.
  • a carriage is a heavy mass high inertia element since it usually comprises a pair of rails slidable in a suitable track mounted on the typewriter base; a platen; line spacing mechanism; paper bail; and a toothed rack.
  • the rack which is secured to the carriage has teeth which are pitched in accordance with the class of type used by the machine, e. g., for pica type, the rack teeth are spaced .100" apart.
  • An escapement pawl is mounted on the typewriter base in operative engagement with the carriage rack to control the stepped movement of a spring biased carriage into alignment with the machines single print position.
  • the escapement pawl is operated by a type bar; i. e., any type bar, during a print stroke, and before it actually prints, strikes a universal bar which actuates the escapement pawl to release the spring biased carriage for movement one step at a time.
  • a type bar i. e., any type bar
  • Such a general construction is shown in U. S. Patent 1,945,847, C. W. Crumrine.
  • this invention relates to an improved carriage construction wherein a light mass carriage rack is positioned for controlled slideable movement relative to the carriage proper, and wherein the light mass rack can be moved into a position for an escapement action, before the heavy mass carriage reaches a corresponding position.
  • Fig. 1 is a perspective exploded view of a portion of a typewriter construction utilizing the improved spacing control rack, while Figs. 2 and 3 are partial plan views of the carriage and rack construction shown in Fig. 1.
  • a carriage escapement mechanism 1 comprising a carriage base 2, a rack 3, an escapement pawl 4,
  • the carriage base 2 supports a work sheet holding platen 7, and associated line spacing and tabulating mechanisms (not shown). Accordingly, the carriage should be considered as a heavy mass element which, because of its high inertia, is slow to start moving.
  • the base 2 is mounted for stepped transverse movement in response to a pull exerted by a tensioned tape 8, which pulls the carriage to the left (Fig. 1), across the typewriter print position 9.
  • the tension in tape 8 is small in comparison to the mass of the carriage base 2, and, therefore, the carriage base starts moving slowly, but it is constantly accelerated by the tape into the next print position.
  • the rack 3 (Figs. 2 and 3) is provided with a plurality of teeth 10, having a line pitch determined by the particular size of the type to be used (e. g., .100" for pica type).
  • Each tooth has a suitable blocking or stop surface 11 for engagement with pawl 4 thereby determining the limits of a stepped rack movement hereinafter described.
  • Each rack tooth further has a crown 12 over which the nose 13 of the pawl must be lifted to be brought into engagement with a sloping or spacing surface 14 of a rack tooth.
  • the escapement pawl 4 further has a tail 15 which is positioned for actuation by the escapement trip lever 5 to pivot the nose 13 out of engagement with any tooth stop surface 11.
  • pawl 4 is mounted for both pivotal and slideable movement with respect to the typewriter base by providing it with an elongated aperture 16 engageable with a stud 17 secured to the typewriter base.
  • a spring 18, interconnecting pawl 4 and the typewriter base pulls pawl 4 over the crest 12 of a tooth 10 and into sliding engagement with a spacing surface 14 (to the position shown in Fig. 3).
  • Spring 18 also biases pawl 4 clockwise about pivot 17 and into engagement with the rack teeth.
  • trip lever 5 is mounted for pivotal movement in a vertical plane, and since its operation is explained in detail in U. S. Patent 1,945,847, C. W. Crumrine, it is felt that a short summary statement of operation should be sulficient at this time.
  • trip lever 5 (Fig. 1) is mounted on a stud 19 secured to the typewriter base.
  • the tail of lever 5 is connected by link 20 to a universal bar 21 which, in turn, is mounted for oscillating movement in response to impact from a type bar enroute to the print position 9, i. e., the universal bar is spring biased (not shown) to a rest position (not shown), and it is driven by a type bar from the rest position to an actuating position (Fig. 1) wherein it is just about to pivot pawl 4 out of engagement with rack teeth 10.
  • a plate 22 is positioned between pawl 4 and the nose 23 of the actuating lever 5.
  • Plate 22, which is parallel to pawl 4, has an elongated aperture 24 (Fig. 2) by which it is mounted on pin 17 under pawl 4.
  • Plate 22 is biased by spring 25 to the right into the normal position shown in Fig. 2.
  • Plate 22 further has a shoulder 26 that overlies the tail 15 of pawl 4 when it is in the rest position shown in Fig. 1, and which is struck by nose 23 of actuating lever 5 to effect the tripping of pawl 4 from the position shown in Fig. 2.
  • the stroke of the pawl is not long enough to abut against the lever 5.
  • lever 22 is provided with a slot 24 and spring 25 so that it may yield and not present a positive block to the pawl. If thereafter, the lever 5 is released, the lever 22 would then under influence of spring 25, snap back to the position of Fig. 2 lever 15:
  • type bar 6 is also well known, but basically (see Fig. 1) it is rotatably supported in a segment 27 which guides the movement of the type bar from rest to a printing position.
  • a type bar actuating lever 28 is conditioned for actuation by key bar 29 and it is driven by power roll 30 to exert a pull on link 31 and thus rotate the type bar 6 to printing position 9 (Fig. 1).
  • This type bar action is shown in detail in U. S. Patent 2,506,444 assigned to same assignee as that of the present invention.
  • rack 3 is mounted for controlled slideable movement relative to carriage base 2.
  • the carriage base 2 is provided with a plurality of outstanding pins 32 (Figs. 2 and 3) while the rack 3 defines suitable elongated apertures 33.
  • the pins are passed through the apertures and peened over or otherwise suitably prevented from slipping through the apertures.
  • the apertures 33 have a transverse diameter slightly greater (sliding fit) than that of the pins 32, but in an axial direction, the apertures are elongated to permit the desired relative axial movement between the rack and carriage base.
  • a spring 34 (Figs.
  • This construction not only quiets the carriage stepped movement-through the cushion provided by spring 34 but further it permits the escapement rack to drive pawl 4 into tripping position before the heavy carriage base has moved into printing position.
  • An escapement mechanism for a carriage of a business machine comprising, in combination, a printing mechanism, a carriage base, means biasing said carriage base for movement in one direction across a fixed printing position, a toothed rack having a tooth pitch equal to the desired stepped movement of said carriage, means mounting said rack on said carriage base for controlled relative axial movement therebetween, means biasing said rack for movement in said one direction relative to said carriage base, a pawl mounted on said machine for releasable engagement with said rack thereby to limit the movement thereof, means supporting said pawl for both pivotal and limited longitudinal movement relative to said carriage, biasing means acting on said pawl for urging the latter into engagement with said rack and toward one limit of its longitudinal movement in a direction opposite to that produced on said rack by said rack biasing means, and means responsive to operation of said printing means when said pawl is moved to the other limit of its longitudinal travel for releasing said pawl from one tooth of said rack whereby said pawl and rack are free for movement each in response to its respective biasing means and

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  • Character Spaces And Line Spaces In Printers (AREA)
US359598A 1953-06-04 1953-06-04 Floating escapement mechanism Expired - Lifetime US2741355A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BE529316D BE529316A (enrdf_load_stackoverflow) 1953-06-04
DENDAT1073007D DE1073007B (de) 1953-06-04 I Schrittschaltvorrichtung fur Schreib wagen von Schreibmaschinen
US359598A US2741355A (en) 1953-06-04 1953-06-04 Floating escapement mechanism
GB16302/54A GB751170A (en) 1953-06-04 1954-06-02 Floating escapement mechanism
CH325481D CH325481A (fr) 1953-06-04 1954-06-03 Mécanisme d'échappement flottant du chariot d'une machine à écrire

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US751170XA 1953-06-04 1953-06-04
US325481XA 1953-06-04 1953-06-04
US359598A US2741355A (en) 1953-06-04 1953-06-04 Floating escapement mechanism

Publications (1)

Publication Number Publication Date
US2741355A true US2741355A (en) 1956-04-10

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ID=27364163

Family Applications (1)

Application Number Title Priority Date Filing Date
US359598A Expired - Lifetime US2741355A (en) 1953-06-04 1953-06-04 Floating escapement mechanism

Country Status (3)

Country Link
US (1) US2741355A (enrdf_load_stackoverflow)
BE (1) BE529316A (enrdf_load_stackoverflow)
CH (1) CH325481A (enrdf_load_stackoverflow)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3211269A (en) * 1964-02-19 1965-10-12 Ibm Escapement assembly with force relieved before removement of pawl from rack
US3366215A (en) * 1965-07-28 1968-01-30 Ibm Single rack backspace
DE1293168B (de) * 1963-06-26 1969-04-24 Ibm Teilschrittschalteinrichtung fuer den Wagen von Schreib- und aehnlichen Maschinen
US3519115A (en) * 1967-09-11 1970-07-07 Singer Co Escapement mechanism responsive to the return portion of a reciprocal rotary motion
US3752289A (en) * 1969-12-31 1973-08-14 Triumph Werke Nuernberg Ag Typewriter escapement and control devices therefor
US3934698A (en) * 1974-02-01 1976-01-27 Mcgourty Thomas K Carriage mechanism for printer
US4687361A (en) * 1985-03-07 1987-08-18 Oki Electric Industry Co., Ltd. Rack mount for a rack and pinion carriage moving mechanism
US4738552A (en) * 1985-03-11 1988-04-19 Oki Electric Industry Co., Ltd. Platen gap adjusting mechanism of printer

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US430775A (en) * 1890-06-24 hamilton
US585235A (en) * 1897-06-29 Type-writing-machine feeding mechanism
US633139A (en) * 1898-05-24 1899-09-19 Thomas A Killman Type-writing machine.
US1539009A (en) * 1923-07-12 1925-05-26 Remington Typewriter Co Typewriting machine

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US430775A (en) * 1890-06-24 hamilton
US585235A (en) * 1897-06-29 Type-writing-machine feeding mechanism
US633139A (en) * 1898-05-24 1899-09-19 Thomas A Killman Type-writing machine.
US1539009A (en) * 1923-07-12 1925-05-26 Remington Typewriter Co Typewriting machine

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1293168B (de) * 1963-06-26 1969-04-24 Ibm Teilschrittschalteinrichtung fuer den Wagen von Schreib- und aehnlichen Maschinen
US3211269A (en) * 1964-02-19 1965-10-12 Ibm Escapement assembly with force relieved before removement of pawl from rack
US3366215A (en) * 1965-07-28 1968-01-30 Ibm Single rack backspace
US3519115A (en) * 1967-09-11 1970-07-07 Singer Co Escapement mechanism responsive to the return portion of a reciprocal rotary motion
US3752289A (en) * 1969-12-31 1973-08-14 Triumph Werke Nuernberg Ag Typewriter escapement and control devices therefor
US3934698A (en) * 1974-02-01 1976-01-27 Mcgourty Thomas K Carriage mechanism for printer
US4687361A (en) * 1985-03-07 1987-08-18 Oki Electric Industry Co., Ltd. Rack mount for a rack and pinion carriage moving mechanism
US4738552A (en) * 1985-03-11 1988-04-19 Oki Electric Industry Co., Ltd. Platen gap adjusting mechanism of printer

Also Published As

Publication number Publication date
CH325481A (fr) 1957-11-15
BE529316A (enrdf_load_stackoverflow)

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