US2879877A - Automatic cut off device - Google Patents

Automatic cut off device Download PDF

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Publication number
US2879877A
US2879877A US478716A US47871654A US2879877A US 2879877 A US2879877 A US 2879877A US 478716 A US478716 A US 478716A US 47871654 A US47871654 A US 47871654A US 2879877 A US2879877 A US 2879877A
Authority
US
United States
Prior art keywords
power
wheel
bracket
cam
climbing wheel
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
US478716A
Other languages
English (en)
Inventor
Stig B Tibbling
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 NL92126D priority Critical patent/NL92126C/xx
Priority to BE544050D priority patent/BE544050A/xx
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Priority to US478716A priority patent/US2879877A/en
Priority to FR1143287D priority patent/FR1143287A/fr
Priority to GB36937/55A priority patent/GB816830A/en
Priority to DEI11096A priority patent/DE1085175B/de
Priority to CH335700D priority patent/CH335700A/fr
Application granted granted Critical
Publication of US2879877A publication Critical patent/US2879877A/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
    • B41J29/00—Details of, or accessories for, typewriters or selective printing mechanisms not otherwise provided for
    • B41J29/38—Drives, motors, controls or automatic cut-off devices for the entire printing mechanism
    • B41J29/387—Automatic cut-off devices

Definitions

  • This invention relates to typewriters and more particularly to an automaticpower cut off device for an electricallyoperatcd typewriter.
  • the typewriter has an electric motor operable under switch control to drive a power driving mechanism for the individual type bars in the typewriter.
  • Modern machines are built so that the motor runs so quietly as not to be detected, and accordingly, it sometimes happens that the motor is unintentionally* left on for prolonged periods.
  • Fig. 1 is a perspective view of some of the component parts of a power driven typewriter
  • Fig. 2 is a section view taken along the plane 2-2 of Fig. 1 in the direction of the arrows;
  • Fig. 3 is an exploded view of the cut off device shown in Fig. 2.
  • this invention relates to an. automatic cut oil device mounted in a bracket that isV pivotally supported on the typewriter for engagement with a continuously driven power roll.
  • a drivingwheel, an operating cam, and a climbing wheel are coaxially mounted in the bracket for engagement with the continuously operated power roll. If the machine is left unattended for a predetermined period, the climbing wheel will frictionally engage the operating cam which will act to cut olf the power to the electric motor.
  • the climbing wheel is resettable to its rest position upon operation of selected ones of the functioning device of the typewriter.
  • a power roll 2 is represented as being continuously rotated in the direction of the arrow under the control of an electric motor which is not shown.
  • the electric motor is represented as being operable under the control of an electricswitch 4 having oli and on position and shown in the o position in Fig. l.
  • the switch 4 is conventionally operated by a link system 6 which is actuated under the control of a switch arm 8 pivotally mounted on a pin 10 supported by the typewriter frame 12. If the switch arm 8 is rotated clockwise as viewed in Fig. 1, the arm 14 of the switch v 21,879,877 Patented Mar. 31, ⁇ 1959 4 will be moved to the dotted line position, thereby en-v ergizing the electric motor.
  • the improved cut oit device is shown as comprising ra bracket 16, a driving wheel 18, a power cam 20, a climbing wheel 22, and associated mechanisms for holding the parts in assembled relation.
  • the cut off device is shown pivotally .mounted byy a.
  • bracket 16 passing through apertures 30 in bracket 16, and mounted in the typewriter frame in such a manner that the driving wheel 18 and the climbing wheel 22 are swingable into and out of peripheral engagement with the continuously rotating power roll 2.
  • a spring 32 biases the bracket normally counterclockwise about pivot 28 to maintain contact of both the driving wheel 18and the climbing wheel 22 with the continuously rotated power roll 2.
  • the driving wheel 18 has integrally therewith a shaft 34, loosely mounted about a supporting pin 36.
  • a threaded bushing 24 is frictionally or force fitted on the shaft 34 for rotation therewith.
  • the threaded bushing serves the dual function of positioning the cam 20 adjacent the driving wheel, and acting as a screw for loosely accommodating an internally threaded bore 37 of the climbing wheel 22.
  • the cam element 20 is loosely mounted about the drive shaft 34 and is supported by bushings 38, 40 so that the drive shaft 34 may rotate within its central bore 42, while the cam 20 is held in a rest position (Fig. l).
  • the peripheral surface of cam 20 comprises a serrated surface 44 and a reduced surface 46. The latter surface is normally positioned so as to be slightly spaced peripherally from the continuously rotating power roll 2. However, if the ⁇ power cam 2t) is rotated slightly counterclockwise from its position shown in Fig. 1 and Fig.
  • the smallest radius of the serrated surface 44 will engage the power roll, thereby establishing a driving relation between the power roll and cam sending the latter through a liip cycle wherein the serrated surfaceof cam 20 will run in peripheral contact with the power roll 2 until after the point of maximum radius of serrated surface 44 has left the power roll, whereupon the power cam 20 will continue on its own momentum until it has reached-its rest position.
  • the latter position is determined by a spring wire 49 which is positioned for tangential engagement with a corresponding iiat surface 51 on the hub of the power cam 20.
  • the spring wire 49 holds cam 20 from rotating while t shaft 34 rotates through its center.
  • the climbing wheel 22 is loosely mounted on the threaded bushing 24, which construction provides-for the gradual moving of the climbing wheel 22 to the right as viewed in Fig. 3, as the climbing wheel rotates counterclockwise relative to the threaded bushing 24, while the loose construction (i.e. the bore 37 being greater than the diameter of bushing 24) permits an axial movement of the climbing wheel 22 relative to the threaded bushing 24 when the climbing wheel 22 has been disengaged from the power roll. More specifically, the climbing relationship between climbing wheel 22 and threaded bushing 24 exists only when a radial pressure is applied between the climbing wheel and the threaded bushing, for example, when the -climbing wheel is in engagement with the power roll.
  • a spring 26 is axially interpositioned between the climbing wheel 22 and the power cam 20. With this arrangement of parts, every time the climbing wheel 22 is removed from the power roll, the spring 26 will act to move the climbing wheel to the left as viewed in Fig. 3, to its rest position.
  • the threaded bushing 24 is a spirally wound spring which provides rounded threads having za maximum outside diameter smaller than the minimum inside diameter of the threaded wheel 22.
  • the drivingwheel 18 and the climbing wheel 22 are in continuous peripheral engagement with the power roll 2, and, therefore, both rotate in the same direction (counterclockwise as viewed in Fig. 1).
  • the climbing wheel 22, however, has a slightly smaller dam eter than that of the driving wheel 18; therefore, the climbing wheel will rotate at a slightly faster rate than the driving wheel 18 and accordingly, it will rotate relative to the threaded shaft 24 thereby permitting the climbing wheel 22 to move to the right along the thread carried by the shaft 24.
  • the right side of the latter (as viewed in Figs.
  • the bracket 16 of the automatic cut off device is connected via the arm 54 to the shift mechanism.
  • arm 54 has a deep yoke 63 acted on by pin 62.
  • the purpose of this structure is that the extent of throw of arm 54 is controlled; i.e. depending on the depth of the yoke, the pin 62 will move through a considerable distance before the arm 54 moves, and consequently, the bracket 16 will be only displaced slightly from the position of Fig. l, and not far enough to shut off the switch 4.
  • the normal operation of the automatic cut off device is such that the climbing wheel 22 and the driving wheel 18 will be in engagement with the power roll 2 to permit the smaller diameter of the climbing wheel to produce relative movement with respect to threaded bushing 24. Accordingly, the climbing wheel will move gradually axially towards the power cam 20. When the climbing wheel has reached a frictional engagement with the hub of power cam '20, the latter will be rotated into engagement with the power roll thereby elfecting a flip cycle, which in turn, will cut off the switch of the typewriter.
  • a power driven typewriter-having a power roll, driving means therefor, and an electrical switch for coutrolling said driving means 'an automatic cut olf device comprising a driving wheel, a power cam, a climbing wheel, and bracket means mounting said parts in co-axial alignment, means pivotally mounting said bracket means for movement from a rest position wherein said wheels are in peripheral engagement with said power roll to an operative position, said climbing wheel-having a slightly smaller diameter than that of said driving wheel to provide for a relative rotational movement therebetween, means operable in response to said differential movement for advancing said climbing wheel laterally toward said driving wheel from a normal or rest position to an actuating position wherein said climbing wheel is in frictional driving engagement with said power cam to urge the latter into peripheral engagement with said power roll to initiate a cam flip cycle, means mounting said power cam on said bracket means to move the latter to its operative position in response to said power cam going through a flip cycle, and means interconnecting 'said bracket means and said switch to shut off said switch
  • an automatic cut ot device comprising a driving wheel, a power cam, a climbing wheel, and bracket means mounting said parts in co-axial alignment, means pivotally mounting said bracket for movement from a rest position wherein said wheels are in peripheral engagement with said power roll to' an operative position, said climbing wheel having a slightly smaller diameter than that of said driving wheel to provide for a relative rotational movement therebetween, means operable in response to said differenti-al movement for advancing said climbing wheel laterally' toward said driving wheel from a normal or rest position to an actuating position wherein said climbing" wheel is in frictional4 driving engagement with said power cam to urge the latter into peripheral engagement with said power roll to initiate a cam flip cycle, means mounting said power cam on said bracket means to move the latter to its operative position in response to said power cam going through a ip cycle, means interconnecting said bracket means and said switch to shut off said switch when said bracket means is rocked to
  • an automatic cut off device comprising a driving wheel, a power cam, a climbing wheel having a diameter slightly smaller than that of said driving wheel and bracket means mounting the same in sequential co-axial alignment, means pivotally mounting said bracket for movement from a normal position wherein said wheels are in peripheral engagement with said power roll to an operative position, spring means biasing said bracket to its normal position, said power cam having a relieved portion normally positioned proximate said power roll and spaced therefrom, screw thread means mounted for rotation with said driving wheel, said climbing wheel having a threaded bore centrally thereof loosely fitting over said screw thread means whereby when said climbing wheel and said driving wheel are in peripheral engagement with said power roll the relative rotation between said screw thread means and said climbing wheel causes the latter to advance laterally towards said power cam, means responsive to the movement of said climbing wheel toward said power cam for urging the latter into peripheral contact with said power roll thereby initiating a flip cycle of said power cam, said
  • an automatic cut off device comprising a driving wheel, a power cam, a climbing wheel having a diameter slightly smaller than that of said driving wheel and bracket means mounting the same in sequential co-axial alignment, means pivotally mounting said bracket means for movement from a normal position wherein said wheels are in peripheral engagement with said power roll to an operative position, spring means biasing said bracket means to its normal position, said power cam having a relieved portion normally positioned proximate said power roll and spaced therefrom, screw thread means mounted for rotation with said driving wheel, said climbing wheel having a threaded bore centrally thereof loosely tting over said screw thread means whereby when said climbing wheel and said driving wheel are in peripheral engagement with said power roll the relative rotation between said screw thread means and said climbing wheel causes the latter to advance laterally towards said power cam, means responsive to the movement of said climbing wheel tow-ard said power cam for urging the latter into peripheral contact with said power roll thereby initiating a flip cycle
  • an automatic cut off device comprising a bracket pivotally mounted in said typewriter for movement from a rest position to an operative position, linkage means interconnecting said bracket and said switch to shut off the latter when said bracket has been moved to its operative position, and actuating means carried by said bracket for rocking the latter from its rest position to its operative position after a predetermined uninterrupted period, said actuating means comprising a pair of wheels of different diameters coaxially mounted in said bracket for rotation in response to the operation of said rotatable power imparting means when said bracket is in its rest position, means for displacing one of said wheels laterally in response to a predetermined diferential rotation of said wheels, and cam means operated in response to the lateral displacement of said one wheel for rocking said bracket from its rest position to its operative position.
  • an automatic cut off device comprising a pair of wheels mounted for rotation about a common axis and driven -by the power roll at different speeds, a differential screw connection between said wheels, whereby there will be relative movement of one of the wheels along said axis with respect to the other, and means elective when said relative movement exceeds a predetermined amount for causing operation of said switch to stop said motor.
  • a power driven typewriter having a driving motor and a switch for control thereof, a pair of wheels mounted for rotation about a common axis, means actuated by said motor for driving said wheels at different speeds, and means responsive to a predetermined differential move ment between said wheels for causing operation of said switch to stop said motor.

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  • Transmission Devices (AREA)
  • Impression-Transfer Materials And Handling Thereof (AREA)
US478716A 1954-12-30 1954-12-30 Automatic cut off device Expired - Lifetime US2879877A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
NL92126D NL92126C (xx) 1954-12-30
BE544050D BE544050A (xx) 1954-12-30
US478716A US2879877A (en) 1954-12-30 1954-12-30 Automatic cut off device
FR1143287D FR1143287A (fr) 1954-12-30 1955-12-21 Coupe-circuit automatique pour machines à écrire
GB36937/55A GB816830A (en) 1954-12-30 1955-12-23 Automatic cut off for electrically operated typewriters
DEI11096A DE1085175B (de) 1954-12-30 1955-12-28 Vorrichtung zum selbsttaetigen Abschalten des Kraftantriebes von Geschaeftsmaschinen, insbesondere kraftangetriebenen Schreibmaschinen
CH335700D CH335700A (fr) 1954-12-30 1955-12-28 Coupe-circuit automatique d'une machine à écrire électrique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US478716A US2879877A (en) 1954-12-30 1954-12-30 Automatic cut off device

Publications (1)

Publication Number Publication Date
US2879877A true US2879877A (en) 1959-03-31

Family

ID=23901093

Family Applications (1)

Application Number Title Priority Date Filing Date
US478716A Expired - Lifetime US2879877A (en) 1954-12-30 1954-12-30 Automatic cut off device

Country Status (7)

Country Link
US (1) US2879877A (xx)
BE (1) BE544050A (xx)
CH (1) CH335700A (xx)
DE (1) DE1085175B (xx)
FR (1) FR1143287A (xx)
GB (1) GB816830A (xx)
NL (1) NL92126C (xx)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1557457A (en) * 1925-10-13 Accounting machine and motor-drive mechanism
US2602529A (en) * 1949-06-16 1952-07-08 Ibm Automatic cutoff switch for typewriters

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE495079C (de) * 1930-04-02 Siemens Schuckertwerke Akt Ges Elektrisch angetriebene Muehle, insbesondere fuer Kaffee, mit selbsttaetiger Ausschaltung
DE1705323U (de) * 1955-03-31 1955-08-25 Brunsviga Maschinenwerke A G Zeitschalter fuer elektromotorische antriebe.

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1557457A (en) * 1925-10-13 Accounting machine and motor-drive mechanism
US2602529A (en) * 1949-06-16 1952-07-08 Ibm Automatic cutoff switch for typewriters

Also Published As

Publication number Publication date
CH335700A (fr) 1959-01-31
FR1143287A (fr) 1957-09-27
GB816830A (en) 1959-07-22
NL92126C (xx)
DE1085175B (de) 1960-07-14
BE544050A (xx)

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