US2880837A - Anti-jamming device for typewriter type bars - Google Patents

Description

April 7, 1959 H. L. LAMBERT ErAl. 3

- ANTI-JAMMING DEVICE FQREYPEWRITER TYPE BARS Filed Mai; e, 1957 SShee'ts-Sheet 1 INVEN TORS HARRY L. LAMBERT ATTORNEYS a v I I Ba 5 k? April 7, 1959 v H. L. LAMBERT ETAL 2,880,837

ANTI-JAMMING DEVICE FOR TYPEWRITER TYPE BARS Filed May 6, 1957 :s Sheets-Sheet 2 INVENTORS HA RRY L.LAMBERT. PAUL F. PAGE ATTORNEYS April 7, .1959 H. L. LARFBERT ETAL 3 ANTI-JAMMING DEVICE FOR TYPEWRITER TYPE BARS v Filed May 6, 1957 I I y s Sheets-Sheet a INVENTOR5 HARRY L. LAMBERT PA L F. PAGE ATFONEYS H w-u VANTI-IAMMING DEVICEFOR mrwmm Y 7 TYPE BARS Harry Long Lambert and Pauli F. Page, West Hartford,

'Conn.,'assignors to Royal McBee 'Corporationylort Chester, N.Y., acorporation of New York Application May 6,1957,SerialNo.657,441

1 ai s-j 21- This, invention relates to an. anti jamming' device for printingniaehines, 'and' more particularly relates to. a mechanism for automaticaly disabling and enabling p the type bar actuatin'g linkag'esof'an electric typewriter..

Each typing action of'a'con'ventional electrictype writer is initiated by operatively engaging a coupling" element of the typ'ebar actuating linkage with a'jpower rolll, Selective depressioniofthe various keys of the machine serves to' sequentially couple the respective coupling elements with said power roll'to thereby opera-' tively displace the correspondingtype bars through their respective printing strokes. Thistyping action may continue aslong as the power rollfis being rotatably driven.

When the machine'is to beidle for a period of time the power supply switch is manually or automatically turned ofi and the power roll is no longer driven. In this con-' dition of the machine one'or'moreof said coupling ele-' ments may be engaged with the stationary roll by the accidental or deliberate depre'ssionofthe-typewriter keys. When the power supply switch is subsequently turned on,

the variouscouplingelements which have been engaged with the power roll'will be simultaneously actuated to, 1;; thereby drive the corresponding type bars towards'the' printing line, .of .the-.machine. ..;Theresultant mutual interference between the type bars seemnttamu cause said bars to jam up as theyapproach the typewriter platen. Such an operation of the machine is obyiously undesirable" not" only because of the l time consuming necessity of manuallynestoring the type bars "to their normal positions but also because such a jamming action may bend or otherwise damage the type bars involved.

One object of the instant invention is to provide a novel means for eliminating the untimely actuation and the jamming of the type bars of a typewriter when the power supply switch of the machine is turned on.

Another object of the invention is to provide a simple reliable mechanism for disabling the coupling elements of a typewriter during the time when the machine is not in use.

A further object of the invention is to provide a mechanism which is capable of disabling and enabling the coupling elements of an electric typewriter and which is automatically operated in response to the manipulation of the power supply switch.

Still another object of the invention is to provide a mechanism which is capable of disabling and enabling the type bar coupling elements of an electric typewriter and which is locked in its enabling condition when the power supply switch is turned on, and is released to its disabling condition when said switch is turned 01f.

Other objects will become apparent as the disclosure progresses.

In the drawings:

Figs. 1 and 2 are side elevational views of the antijamming mechanism and the related parts of a convent i o n al electric typewriter and show the positional relation between said parts and the elements of said mechq linkages may? cor'nprise'v anismlwhen ,theflpower supplyiswitch is in. the onfand.

Fig. 3 is a'front e'levational view'showingf the antijamming mechanismand jits'f structural relation to the adjacent-parts, offthejfmachine. 1=

v'l'here-are sleve'ralfd fi ent ypes of P writers. For example, the powergroll "maycomprise a' longitudinally grooved cylinder. and the associated coupling' elements forfthejvarious type bar. linkages may comprise a seriesof'carrierpawls wliich are selectively en-L gaged with f the jgrooves 'df'lthl'e ipower driven cylinder On theotherhan t e poweri m v' c mp s cy dsr; having an outer coating of hjafrdrubber, or thelike, while i the associated coupling'f'elenjie'ntfs fer the various type;bar series ofjperipherally knurled pivoted. cams 'v'yhich'. are, selectively friction ally 'engaged with the outer,sur'r'acesiof said coatedgcylinder."

For thepurposes of illustration the instant'invention is shownwand descrihed as embodied inf'an electric type-.1 writer of a type."hav'ing a,groovedcylindrical power .roll

and a plurality [of associated jcarrier pawls. Itwill be apparent however.ithat the' invention is capable'ofi'being used withlequal eflicacyjin' electric"typewriters of a type having the above descri 'ed" coated power lroll'an'd. associated knurled cams.

For the sakeof'lclarity the eratiyelyor,structurally perfinent to. the instant invention hav'been omitted from th edrawin'gst It'will be understood that the various elements shown are suitably'sup- Pom-ed? P-l 312 rame 9f, ,,t,he machine in a ma well. lundveIstobdtifiothe a Referring to the drawings there. is shown a.conventional type ,snatchfroll l1 which' jis rotatably driven in a' counterclockwise direction as noted by arrow 2. vPivot-I ally mounted adjacent. the"snatchf roll 1 is a normal complement of spring'biased type bar ac'tuating carrier pawls 3 each having a snatchf roll engaging nose 4. Cooperating with .eachpawl 3jis a pivoted latch 5 which operative engagement with the snatch roll 1 as shown by the dotted lines of Fig. 1. This key controlled selective coupling of the type bar actuating pawls 3 and the roll 1 is of a conventional nature and need not be further particularized here.

Fixedly mounted between the machine side frames 6 and 7 is an elongated comb member 8 to which is secured a pair of spaced upwardly extending brackets 10 and 11. Said brackets pivotally support a ball 12 by means of pins 13 and 14. Springs 15 and 16 are connected between the fixed cross member 17 and the respective side arms 18 and 19 of bail 12 and bias the bail in a counterclockwise direction so that the body portion 20 thereof engages the lower edges of said pawls 3. A forwardly extending arm 25 formed on the left end of bail 12 is provided with a headed stud 26 which is slidably engaged by the walls of an elongated slot 27 formed in the lower end of a link 28. The upper end of link 28 is pivotally connected by means of stud 30 to the rearward end of a lever 32 which is rotatably mounted on the hub 34 of the manually operated throw arm 35 of the typewriter power supply switch. A bent over ear 38 formed on the upper edge of lever 32 overlies the rearwardly disposed extension 40 of said throw arm 35. A laterally disposed bent over portion 42 is also provided at the rearward end of said lever 32.

On stud 43 of the left side frame 7 of the machine there is pivotally mounted a lever 44 which has a shoulder 1 lwer rolls and type; baicoupling elements usedin'conventional electrictypeg;

'various' parts and. components of the electric; typewriterfwhich are not o'p- 45 and a forwardly extending cam following finger 46 formed thereon. A spring 48 biases lever 44 in a counterclockwise direction into engagement with the bent over portion 42 of lever 32. The forward end of finger 46 is adapted to be engaged by the cam surface 50 of the throw arm 35 when the latter is moved clockwise to the off position shown in Fig. 2.

When the typewriter is in normal use and the switch throw arm 35 is in the on position shown in Fig. 1 the lever 32 will be locked in its counterclockwise position by reason of the shoulder 45 underlying the laterally disposed bent over portion 42 of said lever 32. Link 28 will thereby maintain the bail 12 in its clockwise position against the action of springs 15 and 16 whereby the bail body portion 20 remains spaced a sufiicient distance below the pawls 3 to allow said pawls to subsequently drop into engagement with the snatch roll 1 in response to the depression of the typewriter keys.

When the machine is to be idle for a period of time and the power supply switch throw arm 35 is manually or automatically moved to the o position shown in Fig. 2 the cam surface 50 of said arm 35 engages and rearwardly displaces the finger 46 whereupon shoulder 45 of lever 44 is moved out from under the bent over portion 42 of lever 32. This will free the bail 12 for counterclockwise rotation, under the action of springs 15 and 16, to a position wherein the bail body portion 20 engages the lower edges of pawls 3 thereby blocking the latter from moving into operative engagement with the snatch roll 1. Thereafter it will be impossible to operatively couple any of the type bars to the snatch roll prior to the turning on of the power supply switch, hence the possibility of the type bars jamming as above described is eliminated.

When the switch throw arm 35 is restored to the on position of Fig. l the rearward extension 40 of said arm 35 cooperating with the bent over ear 38 will rotate lever 32 and lift link 28 thereby moving the bail 12 to its clockwise or inoperative position, the bent over portion 42 of lever 32 having slid upwardly along the forward edge of lever 44 until shoulder 45 of said lever 44 is moved into locking position beneath said portion 42 under the action of spring 48.

It will be seen that the above described anti-jamming '4 the operative condition of the typewriter power supply switch.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration only and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

The invention claimed is:

1. In a typewriter having a frame, a plurality of type bars movably mounted on said frame, drive means for said type bars, switching means for controlling said drive means, and means for selectively coupling said type bars to said drive means; the improvement comprising a bail pivotally supported on said frame and adapted to move into and out of engagement with said coupling means, spring means for biasing said bail into engagement with said coupling means, locking means for retaining the bail out of engagement with said coupling means against the action of said spring means, and means for releasing said locking means in response to the operation of said switching means.

2. In a typewriter having a frame, a plurality of type bars movably mounted on said frame, power drive means for said type bars, an electrical switch for controlling said drive means, and means for selectively coupling said type bars to said drive means; the improvement comprising a bail pivotally' mounted on said frame and adapted to be moved into and out of engagement with said coupling means, spring means normally urging said bail into engagement with said coupling means, locking means for retaining said bail out of engagement with said coupling means, means responsive to the placing of said switch in the off condition for releasing said locking means to thereby allow said bail to move into engagement with said coupling means, and means responsive to the placing of said switch in the on condition for moving said bail out of engagement with said coupling means.

References Cited in the file of this patent UNITED STATES PATENTS

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