US3190429A - Space bar line lock and escapement interlock mechanism - Google Patents

Description

June 1965 T. N. MADISON ETAL 3,190,429

SPACE BAR LINE LOCK AND ESCAPEMENT INTERLOCK MECHANISM Filed Jan. 28, 1963 INVENTORS THEODORE N. MADISON LUDWICK sz M, 3 BY a ATTORNEYS United States Patent SPACE BAR LINE LOCK AND ESCAPEMENT INTERLUCK IVECHANHSM Theodore N. Madison, Thompsonville, and Lndwick Szeluga, Wapping, Conn, assignors to Royal McBee gorporation, New York, N.Y., a corporation of New ork Filed Jan. 28, 1963, Ser. No. 254,292 Claims. (Cl. 197108) This invention relates to a mechanism in an electric Writing machine, such as, for example, a typewriter, whereby a plurality of actions may be powered, using a carriage return draw band as a source of power. More particularly the invention relates to escapement line lock and space bar lock operating mechanism all powered by a carriage return drawband.

' Certain models of electric typewriters are characterized by an escapement mechanism which includes a rotatable disk carrying a plurality of movable stops which are selectively movable so as to engage an abutment member upon actuation of a key lever or the space bar. Such a mechanism is disclosed in US. Patent 3,045,798. If during carriage return a key lever or the space bar were depressed, an escapement stop would be selected and would engage the abutment with possible damage to the escapement mechanism. These machines also usually include line lock and space bar lock devices that are driven in various Ways upon actuation of the carriage return lever in order to lock out the keyboard. Devices of this general nature are well known in the art and may be such as disclosed in Hart 2,202,415 (a line lock comprising a pivotable stop plate 62 operated through a link 59 by a lever or crank 52) and such as Helmond 1,864,540 (a space bar lock comprising a space bar 21, levers 22, arm 68 and link 31). It occasionally happens, particularly where a very fast typist is operating the machine, that these locking mechanisms do not react fast enough to preclude a key lever or space bar actuation immediately after operation of the carriage return key so that damage to I r the escapement is possible. It is accordingly an object of this invention to provide mechanism of the above nature that precludes such escapement damage. It is another object of the invention to provide such a mechanism that is powered by .the carriage return drawband.

Other objects will be in part apparent and in part pointed out hereinafter.

In the drawing wherein we have shown a preferred embodiment of the invention and wherein similar reference characters refer to similar parts throughout the several views:

FIGURE 1 is a fragmentary top plan view of the mechanism;

FIGURE 2 is a fragmentary section taken along the line 22 of FIGURE 1; and

FIGURE 3 is a fragmentary isometric view of a portion of the mechanism.

As shown in FIGURE 1 a portion of the machine frame is indicated at 10 extending through and secured to which is a shoulder screw 11. A lever, generally indicated at 12 is rockably mounted on screw 11 and includes an arm 13 through which screw 11 extends. A bushing 14 (FIGURE 2) is mounted on the screw which is held in place on the frame by a shoulder 11a on the screw and a nut 15 bearing against the side of frame 10. A drawband pulley 16 is rotatably mounted on screw 11 between the flange 17 of a shroud 18 and the head 11b of the screw, the screw extending through shroud flange 17. Shroud 18 also includes a short flange 19 (FIGURE 2) which overlies the outer side of pulley 16, the shroud ment.

3,190,429 Patented June 22, 1965 accordingly comprising a retainer for a drawband 20 trained over the pulley. Lever 12 includes another arm 21 on which another pulley 22 is rotatably mounted as by a screw 23 which also fastens another drawband shroud 24 similar to shroud 18 to arm 21, this second shroud acting as a retainer for drawband 20 where it trains around pulley 22. The ends of the drawband are respectively conventionally connected to the carriage (not shown) and the usual powered winding drum (not shown) as in the well known electric Royal typewriters- Lever 12 includes another arm 25 (FIGURE 3) through which screw 11 extends, this arm having an operating finger 25a notched as at 25b. Another lever arm 26 is integral with and extends from lever arm 25. As shown in FIGURE 1 a frame anchored spring 27 is connected to lever arm 13 and biases lever 12 counterclockwise, an ear 28 being provided on the lever to engage frame 10 to limit counterclockwise movement of the lever. Thus spring 27 normally holds lever 12 in the FIGURE 1 position forcing pulley 22 upwardly against drawband 20 to form a loop L in the band.

A crank 29 is pivotally mounted on frame 10 and is biased counterclockwise by a spring 30 to its normal FIGURE 1 position. Crank 29 carries a stud 31 adapted to be engaged by a cam surface 13a formed on lever arm 13. Crank 29 also carries a pin 32 adapted to engage a toggle link 33 which is pivotally mounted on frame 10 and which is pivotally connected to another toggle link 34 pivotally connected to an escapement disabling crank 35 which may resemble the member 20 in the said Lambert patent.

From the foregoing it may now be seen that at the time for carriage return the several parts are in their FIGURE 1 positions. Accordingly, when the carriage is released for return movement drawband 20 is tensioned so that its loop L is flattened thus forcing pulley 22 downwardly to rock lever 12 clockwise. Such lever movement swings arm 26 to the right against a line lock crank 36 rocking the crank counterclockwise in line lock setting direction. Crank 36 includes an arm 36a interconnected to frame 10 by a return spring 40 which holds the arm 36a against lever arm 26. Such lever movement also rocks arm 25 clockwise so that the notch 25b in the end 25a thereof embraces a space bar trigger-37 to lock it against move- Also cam 13a on lever arm 13 engages stud 31 to break the toggle links 33 and 34 which rocks escapement crank 35 in escapement disabling direction. Clockwise movement of lever 12 is limited by the engagement of an ear 38 thereon with frame 10. At the end of carriage return the several parts resume their FIGURE 1 positions by virtue of spring 27 Le. spring 27 swings lever 12 counterclockwise permitting spring 30 to restore the toggle and permitting spring 40 to swing crank 36 clockwise to its unlocking position. Thus the several actions are powered by the drawband lending simplicity and efficiency to the system. Crank 36 and trigger 37, in general, resemble lever or crank 52 in the said Hart patent and link 31 in the said Helmond patent.

It should also be noted that when drawband 20 has imparted thereto an increase in tension resulting from actuation of the carriage return mechanism and before the carriage starts to move, lever arm 13 starts its clockwise movement causing the following events in the order stated:

(1) Space bar trigger 37 is locked out by arm 25;

(2) Line lock crank 36 is swung in line locking direction;

(3) The escapement crank 35 is rocked in escapement disabling direction.

Upon completion of these three events, additional tension on drawband 20 initiates carriage return movement.

When the carriage has completed its return travel and comes to rest, tension on the drawband decreases to allow lever 13 to return to its rest position under the bias 'of spring 27. In so doing events 1 -3 release in reverse order, i.e. 3-1. 7 Thus in a constantrnesh escapement,"as

disclosed in the above mentioned-Lambertpatent,Where the escapement is disengagedduring carriage return, the mechanism deseribedabove assures positive engagement and disengagement of theescapement .in relation to carment upon line, spacing thus preventing the occurrence of I carriage bounce; 1

"Still other advantagesresult from this mechanism; Dur ing the end of carriage return travel where a constant mesh engagement is used, the drawband willtemporarily loop out as 'a result of the abrupt stopping of the carriage;

The above described mechanism'not only reduces the loopout by'taking up length of 'thedrawband but'also vvill instantly engage the escapement beforeloopout takes place thus holding the carriage in proper positionl 7 i Thus through the-provision of the above. described mechanism the severalobjectsof the inventionare attained in a thoroughly efiicient and practical manner. 1

, As other embodiments of the inventionare'possible 1. arm and movable thereby into lockingposition upon a pivotal movement ofsaid lever, I

an escapement disabling crank mounted on saidframe for movement between escapement disabling and enabling position, 7 I a and means operated by said fourth lever for moving said escapement crank to escapement disabling position upon pivotal movement of said lever.

2. Mechanism according to claim'l wherein said second, third and-fourth lever arms are so oriented in relation to one another that said space bar trigger, said line "lock crank and saidescapement crank are serially operated in the order named.

3, Mechanism according to claim 1 wherein said means operated by said, fourth lever arm comprises a toggle connected to said'escap'ement crank and includinga cam follower and said fourthlever arm includes acam adapted 'torengage" said followerito break said toggletherebyto rock said escapementj crank to' escapeme nt disabling position; v

4. Mechanism according to claim lwhereinsaid lever includes apair of stopmembers engageable with a POI! tiontof said frame to limit clockwise and counterclockwise pivotal'movement of said lever.

and as modifications of the one disclosed may be made, I,

all without departing from the scope of the invention it is to be understood that the foregoing should be interpreted as illustrative and not in a limiting sense;

We claim: I 1. A typewriter carriage return band contnolled mechanism for operation during carriage'return movement of the typewriter carriage return drawband, in combination,

frame for said lever andrengagedby said, drawband, said second-- I pulley being so located with respect to said first pulley during letter spacingmovement of the drawband so aspto form a loop therein whereby carriage return operation of said band causes tensioning' thereof to straighten said loop thereby causing said drawband to exert pressure. on said second pulley topivot' said lever andraccordingly all of saidlever arms,

spring means interconnectingone of said lever arms and;

said frame to bias said first lever arm, on which said second pulley is mounted to maintain saidloop during and at, the end of letter spacing travel of said 7 drawband, a space bar trigger movably mounted on said frame and operatively associatedwith the second of said lever arms,said second lever arm including means to lock said trigger upon pivotal movement of said' lever,

a line lock operating crankpivotallymounted on said v frame and operatively' associated with said third lever, ROBERT E, PULFREY, Primary'Eraminer,

5. In a typewriter having a carriage return dr awband, the combination of,

aframe, a

a lever pivotally mounted, on said frame,

a pulley rotatably'mounted' on said lever and engaged by a looped portion of said drawband at the terminus of letter spacing travelof said carriage whereby carriage return operation of said carriage causes tensioning thereof to straighten said loop and thereby exert pressure on said'pulley'to rock said lever,

I a line lock crank 'pivotally'mounted on said frame 'for movement between unlocking and locking positions,

a space bar trigger movably mountedon said frame for movement between spacing and non-spacing vpositions, I a

an escapement crank pivotally mounted on said frame for movement between escapement enabling and disablingpositions, I I V I a and means including arms connected tosaid lever and movable therewith on rocking thereof when said loop is straightened to pivotnsaid line lock crank to'its locking position to, hold said space bar trigger in nonspacing position and to pivot said escapement jcrank to escapement disabling position.

References Cited by the Examiner UNITED STATES PATENTS 7 1,226,296 5/l7 [Anderson .Q 197-,66 l r 1,784,047 12/30 Degeneraar 197-65 2,189,942 or 2/40" Eibert' 19765, X 2,362,229 11/44 Yaeger 19.7l07 X 1,647,609 8/53 Sagner 19766 3,018,870 '1/62 Lambert et al. 19784.3 3,045,798 7/62 Lambert et al 19784 i FOREIGN PATENTS 581,662 8/33 7 Germany.

Claims (1)

1. A TYPEWRITER CARRIAGE RETURN BAND CONTROLLED MECHANISM FOR OPERATION DURING CARRIAGE RETURN MOVEMENT OF THE TYPEWRITER CARRIAGE RETURN DRAWBAND, IN COMBINATION, A FRAME, A LEVER COMPRISING FIRST, SECOND, THIRD AND FOURTH ARMS, MEANS TO MOUNT SAID LEVER ON SAID FRAME FOR PIVOTAL MOVEMENT ONLY IN RELATION TO SAID FRAME A FIRST PULLEY ROTATABLY SUPPORTED TO SAID FRAME FOR ENGAGEMENT BY SAID DRAWBAND, A SECOND PULLEY ROTATABLY MOUNTED ON SAID FIRST LEVER ARM AND MOVABLE THEREWITH UPON PIVOTAL MOVEMENT OF SAID LEVER AND ENGAGE BY SAID DRAWBAND, SAID SECOND PULLEY BEING SO LOCATED WITH RESPECT TO SAID FIRST PULLEY DURING LETTER SPACING MOVEMENT OF THE DRAWBAND SO AS TO FORM A LOOP THEREIN WHEREBY CARRIAGE RETURN OPERATION OF SAID BAND CAUSES TENTIONING THEREOF TO STRAIGHTEN SAID LOOP THEREBY CAUSING SAID DRAWBAND TO EXERT PRESSURE ON SAID SECOND PULLEY TO PIVOT SAID LEVER AND ACCORDINGLY ALL OF SAID LEVER ARMS, SPRING MEANS INTERCONNECTING ONE OF SAID LEVER ARMS AND SAID FRAME TO BIAS SAID FIRST LEVER ARM ON WHICH SAID SECOND PULLEY IS MOUNTED TO MAINTAIN SAID LOOP DURING AND AT THE END OF LETTER SPACING TRAVEL OF SAID DRAWBAND, A SPACE BAR TRIGGER MOVABLY MOUNTED ON SAID FRAME AND OPERATIVELY ASSOCIATED WITH THE SECOND OF SAID LEVER ARMS, SAID SECOND LEVER ARM INCLUDING MEANS TO LOCK SAID TRIGGER UPON PIVOTAL MOVEMENT OF SAID LEVER, A LINE LOCK OPERATING CRANK PIVOTALLY MOUNTED ON SAID FRAME AND OPERATIVELY ASSOCIATED WITH SAID THIRD LEVER ARM AND MOVABLE THEREBY INTO LOCKING POSITION UPON PIVOTAL MOVEMENT OF SAID LEVER, AN ESCAPEMENT DISABLING CRANK MOUNTED ON SAID FRAME FOR MOVEMENT BETWEEN ESCAPEMENT DISABLING AND ENABLING POSITION, AND MEANS OPERATED BY SAID FOURTH LEVER FOR MOVING SAID ESCAPEMENT CRANK TO ESCAPEMENT DISABLING POSITION UPON PIVOTAL MOVEMENT OF SAID LEVER.

Images