US3229798A - Adjustable biasing device for the keys of a business machine - Google Patents

Adjustable biasing device for the keys of a business machine Download PDF

Info

Publication number
US3229798A
US3229798A US261159A US26115963A US3229798A US 3229798 A US3229798 A US 3229798A US 261159 A US261159 A US 261159A US 26115963 A US26115963 A US 26115963A US 3229798 A US3229798 A US 3229798A
Authority
US
United States
Prior art keywords
axis
adjusting lever
supporting frame
adjusting
spring
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
US261159A
Other languages
English (en)
Inventor
Grashoff Alfred
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.)
Individual
Original Assignee
Individual
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
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3229798A publication Critical patent/US3229798A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • B41J5/00—Devices or arrangements for controlling character selection
    • B41J5/08—Character or syllable selected by means of keys or keyboards of the typewriter type
    • B41J5/26—Regulating touch, key dip or stroke, or the like
    • 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
    • B41J35/00—Other apparatus or arrangements associated with, or incorporated in, ink-ribbon mechanisms
    • B41J35/04—Ink-ribbon guides
    • B41J35/10—Vibrator mechanisms; Driving gear therefor

Definitions

  • the present invention relates to an adjustable biasing device, and more particularly to a device for resiliently biasing the keys of a business machine for the purpose of adjusting the force of the impact of type levers controlled by the key levers.
  • a related object of the present invention is to provide an adjustable biasing device having fewer parts than known constructions serving the same purpose, and being consequently easier to assemble, and less expensive.
  • Another object of the invention is to provide an adjustable biasing device of simple construction by which the resilient force acting on the key levers of a business machine is adjusted for the purpose of varying the resistance encountered by the fingers of an operator actuating the keys, which has an influence on the impact force exerted by the type levers on the platen.
  • the present invention relates to an adjustable biasing device, which is advantageously applied to the keys of a business machine, such as a typewriter
  • One embodiment of the invention comprises a movable member, which may be used for biasing the keys of a typewriter, a turnable adjusting lever having a plurality of holding portions spaced different radial distances from its axis, and resilient means having one end secured to the movable member, and the other end thereof engaging a holding portion of the adjusting lever which is located on a line connecting the turning axis of the adjusting lever with a point of attachment of the resilient means to the movable member.
  • the distance between the ends of the resilient means is varied in each adjusted position, resulting in a variation of the spring force acting on the movable member, and if this movable member is used for biasing a set of keys, all keys are diiferently biased by turning the adjusting lever.
  • Such different bias will result in a different force required from the operator for actuating the keys, and consequently in a dilferent touch of the keys, and in an adjustment of the impact force exerted ice by the type levers.
  • It is advantageous to use the movable member which biases the key levers also for the purpose of raising the typewriter ribbon upon actuation of any selected key.
  • the end of the resilient means which engages the holding portions of the adjusting lever is provided with an engaging member guided in a guide slot extending in the direction of the above-mentioned line.
  • the holding portions are formed as recesses in an opening in a head portion of the adjusting lever, and successively engaged by the engaging portion of the resilient means when the adjusting lever is turned. In this manner, the adjusting lever is arrested in each adjusted turned position.
  • FIG. 1 is a fragmentary perspective, and exploded view, partially broken off, and illustrating one embodiment of the invention.
  • FIG. 2 is a fragmentary side view on an enlarged scale illustrating the adjustable biasing device of the invention.
  • the supporting frame of the business machine includes a pair of vertical walls 1 and 2 on which a shaft 3 is mounted for turning movement.
  • Shaft 3 has a pair of arms 4 and 5 connected by a rod 6.
  • a spring 9 which will be described in greater detail hereinafter, biases member 3, 4, 5, 6 to turn in counterclockwise direction as viewed in the drawing, so that projections on arms 4 and 5 abut a stop rod 10 which is also secured to walls 1 and 2.
  • Each key lever is mounted for turning movement on a shaft 20, and has a key 25.
  • a spring 22 biases each key lever 21 to turn in counterclockwise direction until abutting a stop 23 extending across all key levers 21.
  • each key lever 21 is biased by a spring 22, upon engagement of rod 6 by an actuated key lever 21, the spring force of spring 9 will be added to the force of the respective spring 22.
  • Member 3, 4, 5, 6 is normally held by stop rod 10 in a position slightly spaced from projections 24 of key levers 21 in the inoperative position abutting stop rod 23, so that spring 9 becomes effective after key lever 21 has been operated to move away from stop rod 23.
  • the resilient means by which member 4, 5, 6 is biased is shown to be an elongated coil spring 9 having one end secured to an attaching means on arm 5.
  • the attaching means is shown to be a bore 7 into which the end of this coil spring 9 is hooked.
  • the other end of coil spring 9 is attached to the lower end of a connecting rod 8 which carries at its upper end a guide member in the form of a cylindrical stud 11 which passes through a guide slot 13 in wall 2.
  • a pivot means 14 is mounted, and supports an adjusting lever 15 for turning movement about an axis.
  • a line connecting the axis of pivot means 14 with attaching bore 7 extends substantially perpendicularly to arm 5.
  • Adjusting lever 15 has a wider head portion formed with an opening which is bounded by a holding track including, for example, four recessed holding portions 16, 17, 18 and 19. Each holding portion 16, 17, 18 and 19 is spaced a different radial distance from the axis of pivot means 14, which is also the turning axis of adjusting lever 15.
  • a portion of guide member 11 projects from the other side of wall 2, and engages one of the recessed holding portions 16 to 19 of the adjusting lever.
  • the engaging portion of guide member 12 engages the recessed holding portion 16 which is farthest spaced from the turning axis of adjusting lever 15, and from pivot means 14.
  • the engaging portion of member 11 will engage the recessed holding portion 18 which is closer to pivot means 14, so that spring 9 is stretched and its spring force increased. It will be understood that by manually turning adjusting lever 15 between four different adjusted positions, the tension of spring 9 can be adjusted so that a different spring force has to be overcome by each operated key lever 21.
  • the recessed holding portion engaged by engaging portion 11 is located on the line which connects the axis of adjusting lever 15 with the attaching means 7. Irrespective of the adjustment of the spring force by turning adjusting lever 15, the force of spring 9 will always act along the above mentioned line and directly on the pivot means 14. Consequently, the force of spring 9 will tend to hold adjusting lever 15 in each adjusted position, and there will be no turning moment exerted on lever 15 which would tend to turn adjusting lever 15 out of an adjusted position selected by the operator,
  • pivot means 14 the operative holding portion 16 to 19, engaging member 11, spring 9, and attaching means 7 along a single line or plane extending substantially perpendicularly to the plane of arms 4- and 5.
  • adjusting lever 15 When it is desired to adjust the device to a position in which the finger pressure to be exerted on keys 25 is lowest, adjusting lever 15 is manually turned to the position illustrated in solid lines in FIG. 2. In this position, spring 9 is permitted to contract to its shortest length, and consequently exerts the smallest biasing force on the key levers 21. Since no turning moment is exerted by spring 9, adjusting lever 15 is arrested in this position.
  • adjusting lever 15 When a greater resilient resistance of the key levers is desired, adjusting lever 15 may be turned to the position illustrated in broken lines in FIG. 2 in which holding portion 18 is engaged by the engaging portion 11. Since holding portion 18 is spaced a shorter distance from the turning. axis of adjusting lever 15, spring 9 is stretched and exerts a greater resilient force so that the bias of the key levers 21 is increased. During such turning movement of adjusting lever 15, the slide portion of member 11 slides in slot 13 so that member 11 cannot be tran versely moved together with the turning adjusting lever 15. When adjusting lever 15 is turned in clockwise direction to its end position, spring 9 is fully expanded and the key levers are biased to require an even greater manual force for operation.
  • a keyboard operated machine including a touch adjustment arrangement, in combination, a supporting frame: a plurality of key levers mounted pivotally and parallel to each other on said supporting frame; a movable elongated touch control member engaging all said key levers spaced from the points at which they are pivoted to said supporting frame; attaching means secured to said movable touch control member; an adjusting member mounted on said supporting frame for turning movement about.
  • said adjusting member having a plurality of holding portions spaced different radial distances from said axis and being turnable about said axis into a plurality of adjusted positions in which different holding portions are located on a straight line connecting said axis with said attaching means; and tension spring means for pulling said movable elongated touch control member toward said adjusting member, said tension spring means having one end secured to said attaching means and the other end thereof engaging the holding portion which is located on said line, whereby in ditferent adjusted positions of said adjusting member the distance between the ends of said tension spring means and thereby the force of tension spring means pulling said movable elongated touch control member toward said adjusting means is varied while no turning moment is exerted on said adjusting member by said tension spring means.
  • Adjustable biasing device comprising, in combination, supporting means; a movable member mounted on said supporting means and having an attaching means; an adjusting lever mounted on said supporting means for turning movement about an axis, said adjusting lever having a holding means including a plurality of holding portions spaced different radial distances from said axis, said adjusting lever being.
  • Adjustable biasing device comprising, in combination, supporting means; a movable member mounted on said supporting means and having an attaching means; an adjusting lever mounted on said supporting means for turning movement about an axis, said adjusting lever having a holding means including a plurality of holding portions spaced different radial distances from said axis, said adjusting lever being turnable about said axis between a plurality of adjusting positions in which different holding portions are located on a straight line connecting said axis with said attaching means; a stationary guide means having a guide slot extending along said straight line; resilient means having one end secured to said attaching means; and a guide member secured to the other end of said resilient means guided in said guide slot and engaging the holding portion which is located on said line whereby in different adjusted positions of said adjusting lever the distance between the ends of said resilient means and the resilient force acting on said movable member are varied while no turning moment is exerted on said adjusting lever by said resilient means.
  • Adjustable basing device for the keys of a business machine, comprising, in combination, supporting frame means; a plurality of key levers mounted on said supporting frame means; a member mounted on said supporting frame means for turning movement and including a part extending across said key levers and adapted to be engaged and turned by any operated key lever, said member having an attaching means; an adjusting lever mounted on said supporting frame means for manual turning movement about an axis, said adjusting lever having a holding means including a plurality of holding portions spaced different radial distances from said axis, said adjusting lever being manually turnable about said axis between a plurality of adjusted positions in which different holding portions are located on a straight line connecting said axis with said attaching means; and resilient means having one end secured to said attaching means and having at the other end thereof an engaging portion slidably engaging said holding means, said engaging portion abutting the holding portion which is located on said line whereby in different adjusting positions of said adjusting lever the distance between the ends of said resilient means, and the resilient force acting
  • Adjustable biasing device for the keys of a business machine, comprising, in combination, supporting frame means having a guide means; a plurality of key levers mounted on said supporting frame means; a member mounted on said supporting frame means for turning movement and including a part extending across said key levers and adapted to be engaged and turned by any operated key lever, said member having an attaching means; an adjusting lever mounted on said supporting frame means for manual turning movement about an axis, said adjusting lever having a holding means including a plurality of holding portions spaced different radial distances from said axis, said adjusting lever being manually turnable about said axis between a plurality of adjusted positions in which different holding portions are located on a straight line connecting said axis with said attaching means and extending along said guide slot; an elongated spring having one end secured to said attaching means; and a guide member secured to the other end of said coil spring and being guided in said guide means, said guide member having an engaging portion projecting from said guide means slidably engaging said holding means, said engaging
  • Adjustable biasing device for the keys of a business machine, comprising, in combination, supporting frame means having a guide slot; a plurality of key levers mounted on said supporting frame means; a member mounted on said supporting frame means for turning movement and including a part extending across said key levers and adapted to be engaged and turned by any operated key lever, said member having an attaching means; an adjusting lever mounted on said supporting frame means for manual turning movement about an axis, said adjusting lever having a holding track including a plurality of recessed holding portions spaced different radial distances from said axis, said adjusting lever being manually turnable about said axis between a plurality of adjusted positions in which different recessed holding portions are located on a straight line connecting said axis with said attaching means and extending along said guide slot; an elongated coil spring having one end secured to said attaching means; and a guide member secured to the other end of said coil spring and being guided in said guide slot, said guide member having an engaging portion projecting from said guide slot slidably engaging said
  • Adjustable biasing device for the keys of a business machine, comprising, in combination, supporting frame means having a guide slot; a plurality of key levers mounted on said supporting frame means; a member mounted on said supporting frame means for turning movement and including a part extending across said key levers and adapted to be engaged and turned by any operated key lever, said member having an attaching means; an adjusting lever mounted on said supporting frame means for manual turning movement about an axis, said adjusting lever having a holding track including a plurality of recessed holding portions spaced different radial distances from said axis, said adjusting lever being manually turnable about said axis between a plurality of adjusted positions in which different recessed holding portions are located on a straight line connecting said axis with said attaching means and extending along said guide slot; an elongated coil spring having one end secured to said attaching means; and a connecting rod secured to the other end of said coil spring and having a guide portion guided in said guide slot and an engaging portion projecting from said guide slot slidably engaging said
  • Adjustable biasing device for the keys of a business machine, comprising, in combination, supporting frame means; a plurality of key levers mounted on said supporting frame means; a member mounted on said supporting frame means for turning movement and including a part extending across said key levers and adapted to be engaged and turned by any operated key lever, said member having an attaching means; pivot means mounted on said frame means; an adjusting lever mounted on said pivot means for manual turning movement about an axis, said adjusting lever having a head portion formed with an opening, said opening being bounded on one side by a holding track including at least three recessed holding portions spaced different radial distances from said axis, said adjusting lever being manually turnable about said axis between at least three adjusted positions in which recessed holding portions are located on a straight line connecting said axis and said pivot means with said attaching means; and resilient means having one end secured to said attaching means and having at the other end thereof an engaging portion slidably engaging said holding track, said engaging portion abutting the recessed holding portion which is
  • Adjustable biasing device for the keys of a business machine, comprising, in combination, supporting frame means; a plurality of key levers mounted on said supporting frame means; a member including a supporting shaft mounted for turning movement on said frame means, at least two arms projecting from said shaft, and a rod connecting said arms and extending across said key levers and adapted to be engaged by any operated key lever so that said member is turned thereby, one arm of said member having a bore; an adjusting lever mounted on said supporting frame means for manual turning movement about an axis, said adjusting lever having a holding means including a plurality of holding portions spaced different radial distances from said axis, said adjusting lever being manually turnable about said axis between a plurality of adjusted positions in which different holding portions are located on a straight line connecting said axis with said bore; and resilient means having one end secured to said bore and having at the other end thereof an engaging portion slidably engaging said holding means, said engaging portion abutting the holding portion which is located on said line whereby in different adjusted
  • Adjustable biasing device for the keys of a business machine, comprising, in combination, supporting frame means having a guide slot; a plurality of key levers mounted on said supporting frame means; a member including a supporting shaft mounted for turning movement on said frame means, at least two arms projecting from said shaft, and a rod connecting said arms and extending across said key levers and adapted to be engaged by any operated key lever so that said member is turned thereby, said member being adaptedto be connected to means for raising the ribbon of the business machine for raising the ribbon when a key lever is operated, one arm of said member having a bore; an adjusting lever mounted on said supporting frame means for manual turning movement about an axis, said adjusting lever having a holding track including at least three recessed holding portions spaced different radial distances from said axis, said adjusting lever being manually turnable about said axis between at least three adjusted positions in which different recessed holding portions arev located on a straight line connecting said axis with said bore and extending along said guide slot; an elongated coil spring
  • said frame means includes a wall formed with said guide slot and supporting said pivot means.
  • a keyboard operated machine including a touch adjustment arrangement, in combination, a supporting frame; a plurality of key levers mounted pivotally and parallel to each other on said supporting frame; a movable elongated touch control member engaging all said key levers spaced from the points at which they are pivoted to said supporting frame; attaching means secured to said movable touch control member; an adjusting member mounted on said supporting frame for turning movement about an axis, said adjusting member having a holding track eccentric to said axis and including track portions spaced different radial distances from said axis, said adjusting member being turnable between a plurality of adjusted positions in which different track portions are located on a straight line connecting said axis with said attaching means; and tension spring means for pulling said movable elongated touch control member toward said adjusting member, said tension spring means having one end secured to said attaching means and the other end thereof engaging the track portion which is located on said straight line, whereby in different adjusted positions of said adjusting member the distance between the ends of said tension spring means and

Landscapes

  • Transmission Devices (AREA)
  • Impression-Transfer Materials And Handling Thereof (AREA)
US261159A 1962-03-06 1963-02-26 Adjustable biasing device for the keys of a business machine Expired - Lifetime US3229798A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEG34410A DE1217978B (de) 1962-03-06 1962-03-06 Tastenanschlag-Reguliervorrichtung an Schreib- und aehnlichen Maschinen

Publications (1)

Publication Number Publication Date
US3229798A true US3229798A (en) 1966-01-18

Family

ID=7124919

Family Applications (1)

Application Number Title Priority Date Filing Date
US261159A Expired - Lifetime US3229798A (en) 1962-03-06 1963-02-26 Adjustable biasing device for the keys of a business machine

Country Status (3)

Country Link
US (1) US3229798A (de)
DE (1) DE1217978B (de)
NL (1) NL289857A (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3387694A (en) * 1966-12-21 1968-06-11 Teletype Corp Key lever return mechanism
US3409111A (en) * 1967-06-07 1968-11-05 Scm Corp Keylever touch control with compensating means directly proportional to keylever touch
US3517787A (en) * 1968-04-19 1970-06-30 Budd Co Sleet scraper for third rail assembly
US3786905A (en) * 1970-12-15 1974-01-22 Paillard Sa Device for the individual adjustment of the striking force in a typewriter
US3835772A (en) * 1971-10-06 1974-09-17 Heyer Inc Compensating impression roller mount for stencil duplicator
EP0016657A2 (de) * 1979-03-22 1980-10-01 Ing. C. Olivetti & C., S.p.A. Farbbandkassette für Schreibmaschinen und dergl.
US4491069A (en) * 1982-07-13 1985-01-01 Brother Kogyo Kabushiki Kaisha Printing hammer driver mechanism

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US319516A (en) * 1885-06-09 Bag-fastener
US1418149A (en) * 1919-11-17 1922-05-30 Joel W Hubble Tire-chain fastener
US1876138A (en) * 1929-12-05 1932-09-06 Eclipse Textile Devices Inc Spring adjustment
US2226924A (en) * 1937-06-04 1940-12-31 Underwood Elliott Fisher Co Typewriting machine
US2235416A (en) * 1938-09-15 1941-03-18 Remington Rand Inc Typewriting and like machines
US2344167A (en) * 1941-12-26 1944-03-14 Underwood Elliott Fisher Co Typewriting machine
US2506218A (en) * 1946-03-06 1950-05-02 Ingram Orville Spring device for drop end doors of gondola cars
US2682944A (en) * 1953-03-06 1954-07-06 Remington Rand Inc Typewriter type-action and touch control
US2987161A (en) * 1959-03-17 1961-06-06 Olympia Werke Ag Touch adjustment arrangement for typewriters

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2020223A (en) * 1935-05-02 1935-11-05 Royal Typewriter Co Inc Typewriting machine
DE711161C (de) * 1937-02-05 1941-09-26 Torpedo Werke A G Fahrraeder U Typenhebelantrieb fuer schreibende Geschaeftsmaschinen mit Einrichtung zum Veraendern der Anschlagstaerke
DE932014C (de) * 1952-09-18 1955-08-22 Olympia Werke Ag Vorrichtung zur Anschlagregelung bei Schreibmaschinen
DE1829040U (de) * 1955-10-13 1961-04-06 Triump Werke Nuernberg A G Vorrichtung zum einstellen der tastenanschlagstaerke bei tastenbetaetigten maschinen.
US2886158A (en) * 1956-06-01 1959-05-12 Alderwerke Vorm Heinrich Kleye Mechanism for varying the stroke of the keys of power-operated typewriters

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US319516A (en) * 1885-06-09 Bag-fastener
US1418149A (en) * 1919-11-17 1922-05-30 Joel W Hubble Tire-chain fastener
US1876138A (en) * 1929-12-05 1932-09-06 Eclipse Textile Devices Inc Spring adjustment
US2226924A (en) * 1937-06-04 1940-12-31 Underwood Elliott Fisher Co Typewriting machine
US2235416A (en) * 1938-09-15 1941-03-18 Remington Rand Inc Typewriting and like machines
US2344167A (en) * 1941-12-26 1944-03-14 Underwood Elliott Fisher Co Typewriting machine
US2506218A (en) * 1946-03-06 1950-05-02 Ingram Orville Spring device for drop end doors of gondola cars
US2682944A (en) * 1953-03-06 1954-07-06 Remington Rand Inc Typewriter type-action and touch control
US2987161A (en) * 1959-03-17 1961-06-06 Olympia Werke Ag Touch adjustment arrangement for typewriters

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3387694A (en) * 1966-12-21 1968-06-11 Teletype Corp Key lever return mechanism
US3409111A (en) * 1967-06-07 1968-11-05 Scm Corp Keylever touch control with compensating means directly proportional to keylever touch
US3517787A (en) * 1968-04-19 1970-06-30 Budd Co Sleet scraper for third rail assembly
US3786905A (en) * 1970-12-15 1974-01-22 Paillard Sa Device for the individual adjustment of the striking force in a typewriter
US3835772A (en) * 1971-10-06 1974-09-17 Heyer Inc Compensating impression roller mount for stencil duplicator
EP0016657A2 (de) * 1979-03-22 1980-10-01 Ing. C. Olivetti & C., S.p.A. Farbbandkassette für Schreibmaschinen und dergl.
EP0016657A3 (en) * 1979-03-22 1981-11-04 Ing. C. Olivetti & C., S.P.A. Ink ribbon cartridge and actuating mechanism, and typewriter therefor
US4491069A (en) * 1982-07-13 1985-01-01 Brother Kogyo Kabushiki Kaisha Printing hammer driver mechanism

Also Published As

Publication number Publication date
DE1217978B (de) 1966-06-02
NL289857A (de)

Similar Documents

Publication Publication Date Title
US3229798A (en) Adjustable biasing device for the keys of a business machine
US3225884A (en) Type lever action control arrangement
US3623587A (en) Type action drive
US2897941A (en) Type bar trip mechanism
US2682944A (en) Typewriter type-action and touch control
US3638775A (en) Repeat action mechanism for power-operated typewriters
US2209227A (en) Typewriting machine
US2691438A (en) Automatically and key controlled power actuating mechanism
US2987161A (en) Touch adjustment arrangement for typewriters
US2890782A (en) Adjusting device for spring-loaded key levers
US2226924A (en) Typewriting machine
US2757774A (en) Impression regulating control for power driven typewriters
US3179226A (en) Impression control mechanism
US2940576A (en) Typewriter mechanism
US2865488A (en) Proportional letter feed mechainism
US3204747A (en) Stop setting and clearing mechanism for typewriting and like printing machines
US2858925A (en) Keyboard touch device
US3409111A (en) Keylever touch control with compensating means directly proportional to keylever touch
US3310148A (en) Expand device for proportional escapement typewriters
US2897943A (en) Carriage return control arrangement
US2168518A (en) Typewriting machine
US3023696A (en) Printer keyboard
US2992719A (en) Stop mounting arrangement for typewriter line spacing devices
US948973A (en) Writing-machine.
US605264A (en) Type writing machine