US2557976A - Action blocking or locking mechanism for power-operated typewriters or like machines - Google Patents

Description

J 1951 J. F. KLOSKI ACTION BLOCKING 0R LOCKING MECHANISM FOR POWER-OPERATED TYPEWRITERS 0R LIKE MACHINES 2 Sheets-Sheet 1 Filed Aug. 11, 1948 INVENTOR JOHN F. KLOSKI NEY5' ATTO June 26, 1951 J. F. KLOSKI ACTION BLOCKING 0R LOCKING MECHANISM FOR POWER-OPERATED TYPEWRITERS 0R LIKE MACH Filed Aug. 11, 1948 2 Sheets-Sheet 2 INVENTOR Jam/E KLOS/f! BY EJMM,M%, W

Patented June 26, 1951 ACTION BLOCKING OR LOCKING MECH- ANISM FOR POWER-OPERATED TYPE- WRITERS R LIKE MACHINES John F. Kloski, Hartford, Conn., assignor to Royal Typewriter Company; Inc., New York, N. Y., a

corporation of New York Application August 11, 1948, Serial No. 43,634

13 Claims.

This invention relates to action blocking or locking mechanism for power-operated typewriter or like machines, and more particularly to so-called line lock mechanism, that is, mechanism which is automatically rendered effective for preventing further operation of certain machine parts, especially the type action parts, when the carriage reaches a predetermined margin position during its letter spacing travel.

7 An object of the invention is to provide an improved mechanism of the kind referred to, including a member which may be moved from a normally ineffective position toa position in which it blocks certain parts of drive-transmitting connections against being moved into engagement with a power-operated driving member.

Another object of the invention is to provide mechanism of the class referred to in which the blocking member is operable upon drive-transmitting pawls which, but for the action of the blocking member, would be moved under a bias,

e. g., by spring means, into engagement with the power-operated driving member under control of operating keys.

Another object of the invention is to provide mechanism of the character stated in which the parts are so constructed and operatively related that when the blocking member is in blocking position a key may be depressed in the normal manner without being restrained substantially by the blocking member, the latter nevertheless preventing the drive-transmitting mechanism from becoming engaged with the power-operated driving member.

A further object of the invention is to provide a line lock mechanism including a blocking element of novel formation which is adapted to be effective for preventing transmission of power to the typing members, but which is incapable of preventing transmission of power to other mechanism, for example, back spacing mechanism.

Other objects will become apparent from a reading of the following description, the appended claims, and the accompanying drawings, in which:

Figure 1 is a fragmentary, vertical, fore-andaft sectional view of typewriting machine mechanism embodying the invention, some parts being shown in elevation;

Figure 2 is a fragmentary, vertical, end-to-end sectional view on the line 22 of Figure 1, drawn on an enlarged scale;

Figure 3 is a fragmentary, vertical, sectional view showing, on an enlarged scale, certain of the parts illustrated in Figure 1, a blocking shield being shown ina position different from that shown in Figure 1;

Figure 4 is a fragmentary, horizontal, sectional view taken on the line 4-4 of Figure 1 and drawn on an enlarged scale;

Figure dis a fragmentary detail View showing a portion of a blocking shield notched to render it ineffective for blocking certain drive-transmitting pawls; and

Figure 6 is a group or exploded view showing parts for mounting the blocking shield.

The invention may be embodied in typewriters or like machines of various kinds. For the purposes of illustration, the invention is shown as being embodied in an office type typewriter having, except for the power and line lock mechanism to be described, many featuresin common with the well known Royal Standard typewriter. The drawings show only enough of the standard or known typewriter construction to assist in illustrating the manner in which mechanism embodying the invention may be coordinated with a typewriter construction.

The known construction illustrated includes a main frame A on which a carriage B is mounted for letter spacing and return movements by means of a top rail l secured to the carriage, and rolling upon balls 2, which in turn are adapted to roll on a frame-mounted bottom rail or track 3. The carriage includes the usual end plates 4 and 5 on which a platen or cylinder 6 is journaled so that it can be rotated for line spacing.

A toothed margin stop bar 1 is mounted at its opposite ends on the carriage end plates 4 and 5. Right and left hand margin stops 8 and 9 respectively are mounted to slide along the bar 7 so that they may be positioned adjustably on the bar to cooperate with a center stop It) for determining the margins at the edges of work sheets typed upon. The stops 8 and 9 are shown as being equipped with the usual adjustable abutment screws II and I2 respectively, and may be releasably held in adjusted positions on the rod 1 by any suitable means (not shown), preferably, however, by mechanism of the kind disclosed in the patent to Hart, No. 2,208,367.

A plurality of type bars, a part of one of which is shown at !3, are pivoted. at M on a type bar segment mounted on the frame and shown in part at [5 in Figure 1. The heel of the type bar I3 is connected by a link It to a front lever I! which is pivoted at I 8 on a frame cross bar or mounting rail IS. A link 20 is connected at its front end to the lever I1, and at its rear end is formed with a hookll which receives a universal 6,066, filed February 3, 1948.

bar 22 forming part of a rocker frame 23 pivoted by means (not shown) on the frame A. A spring 24, connected between the front end portion of the link 29 and a spring anchor plate 25, yieldably maintains the type bar in its inactive position. The structure shown also includes a key lever mounting rail or bar 26 and a key lever abutment 2'1, both of which are carried on the main frame.

The parts described so far are generally similar. in construction and relative arrangement to the construction and relative arrangement of conventional parts in the well known Royal Standard typewriter. The present invention relates to other parts to be described later, and to the combination or relative arrangement of such other parts with the conventional parts referred to. Although only one type bar and associated set of operating connections are illustrated in the drawing, it will be understood that, in practice, the invention is embodied in a complete machine including a plurality of type bars. The other type bars inot shown) and their associated operating connections are similar to the type bar i3 and its operating connections. Inasmuch as the whole set of type bars of a complete machine is pivoted on an arcuate segment, some of the operating connections, such as the counterparts of the links l6 and levers H, vary in dimensions; but the general arrangement and operating principle are the same with respect to each type action. Accordingly, a descritpion of the present invention, as applied in connection with the single illustrated type bar l3, will serve also as a description of the application of the invention to the several type bars in a complete machine.

Power mechanism forming part of or used in connection with apparatus embodying the invention may be of the kind shown in the copending application of William Kupper, Serial No. It includes a driving element which operates continuously, and controllable driving connections which normally are inoperative or ineffective, but which may be conditioned by the operator to effect operative driving connection between the continuously moving driving member and the type bar 13. In the mechanism shown in the drawings, the driving member is constituted by a continuously rotating element, more particularly a toothed snatch roll or bar 28, which may be of known form, and which is adapted to be driven in the direction of the arrow at in Figure l by any suitable prime mover such as an electric motor (not shown).

The connections for transmitting drive from i the driving member 28 to the type bar l3 include an actuator 29 which extends fore-and-aft of the typewriter and above the member 28. The actuator is pivoted as at 30 to the lever i"! at a point offset relatively to the pivot 18, and has a forwardly extending part 3! projecting under an abutment or guide plate 32 mounted by screws 33 on the frame A to extend parallel to the snatch roll 28. A spring 34, interposed between the front end of the actuator 29 and an anchor plate 35,

- yieldably urges the actuator to rock clockwise,

and thus normally maintains the actuator in the position shown in Figure l with its front end part 3| bearing against the abutment or guide plate 32. Another abutment 36 is, disposed below the abutment 32 so as to underlie the actuator front end part 3!. The abutments 32 and 36 are formed with fore-and-aft extending slits providing a plurality of separate abutment portions 4 which are adapted to be adjusted separately by being bent vertically.

In order to drive the type bar 13 to the printing position, the actuator 29 is operatively but indirectly connected to the driving member 28, the

- actuator itself never engaging the driving memher. Mechanism for bringing about the operative connection of the actuator 29 to the member 28 includes an interponent pawl 3?, which is pivoted as at 38 on the actuator. A spring 39, anchored to the actuator 29 and connected to the pawl 31, urges the latter to rock clockwise so as to move its nose into engagement with the snatch roll 28. Normally, the pawl is maintained out of engagement with the snatch roll by the restraining action of a control element or trigger 40 which is pivoted as at M on the actuator 29. In the normal position of the trigger, shown in Figure 1, its rear end engages a holding surface is formed with an inclined cam face 53 which is located just below the holding surface 42, and

which is acted upon by the trigger for rocking the pawl counterclockwise, and thus re-setting it in normal, inoperative position.

Key controlled means is provided for bringing about operative driving connection between the member 28 and the actuator 29. This means includes a key M pivoted as at on a rod carried by the cross bar 26. The key M has an upward projection 56 disposed behind an arm 4? of an operating lever 48, pivoted as at 33 on another frameunounted cross bar 50. The lever 48 has another arm 51 on which a limber dog or flipper 52 is pivoted at 53. A spring 54 urges the limber dog 52 to rock clockwise to yieldably retain it in its normal position of rest against a limit stop 55. The dog 52 can swing counterclockwise from the position shown in Figure 1, but cannot move clockwise from this position.

In operation, when the key 44 is depressed, the lever 58 is rocked clockwise so as to cause the flipper 52 to press downwardly on the actuator 29. In this manner, the actuator is initially rocked counterclockwise about its pivot 39 to an extent sufficient to move the lower part of the front end of the trigger 46 against the abutment surface 36, thereby rocking the trigger clockwise about its pivot 41 and causing the trigger rear end to move off and below the holding face 42 of the pawl 3'5. This releases the pawl from the restraining action of the trigger, and enables the spring 39 to rock the pawl 31 quickly so as instantaneously to bring the pawl nose into comtion with the driving member 28. Inasmuch as p the pawl 3'5 is moved by spring action, as distinguished from being moved manually into engagement with the snatch roll 28, there is no possibility of moving the pawl nose just barely into the path of the teeth on the snatch roll. Thus, once the key 44 has been depressed sufiiciently to move the trigger 30 to pawl-releasing position, the pawl 31 will snap immediately and completely into the effective drive-transmitting position.

The pawl 37, and with it the actuator 29, then will be driven toward the left, as viewed in Figure 1. Consequently, the actuator pivot 30 will be moved so as to rock the front lever 1! counterclockwise about its pivot (8, thereby pulling forwardly on the link l6 and moving the type bar 13 toward printing position. After a predetermined of the moving parts to free the pawl from the driving member 28, whereupon the spring 34 will rock the' actuator clockwise to move its front end portion 3I upwardly into engagement with the guide plate 32. Upward movement of the actuator of the trigger into engagement with the trigger re-setting means 32, thus rocking the trigger counterclockwise about its pivot 38. This will cause the trigger rear end portion to bear against the pawl re-setter cam device 43, thereby rocking the pawl 37 to position its nose well above the level of the driving member 28. The rocking of the trigger 40 will be sufiicient to move its rear end into restraining position in contact with the holding surface 42 on the pawl 31. The spring 24 will then move the actuator 29 to its initial position, thus moving the type bar I3 to its position of rest, and completing an operating cycle.

New and improved line lock mechanism is provided for preventing the operating of the typing on themain frame at I0I0. The lever; 69 comprises an upper horizontal arm II, a lower horizontal arm I2, and a vertically extending portion mechanism after the carriage has reached theend of its travel in the typing of a line and has been arrested by coaction of the abutment screw II of the margin stop 8 and the center stop III. In most typewriters, the line lock mechanism includes a device or equipment normally in inactive position but which is adapted to be moved to active position when the-carriage reaches the end ofits letter-spacing travel for blocking or otherwise preventing depression of the key levers. An example of such prior art mechanism is disclosed in thepatent to Henry J. Hart, Number 2,202,451,

granted May 28, 1940.

Line lock mechanism embodying the present invention need not act upon or prevent operation of the typing keys themselves, but instead is arranged to prevent the power mechanism-in this case, the snatch roll 28from being operatively connected to the type bars in response to depression of the typing keys. 7 In the form shown, an elongated shield 56, curved in crosssection, is

provided with pivot pins 51 and 58 which mount the shield 56 in frame walls 59 and 60 so as to .rock toward and away from the snatch roll 28.

The shield 56 extends longitudinally of and behind, and partially above, the snatch roll 28, and

normally is disposed as shown in Figure 1, so

that its front edge BI is positioned to the rear of the path of downward movement of the nose of the pawl 31 when the pawl moves into engagement with the snatch roll 28. Thus, as.so normally positioned, the shield 56 can have no eifect upon the operation of the pawl 31, permitting the pawl and the associated mechanism to be operated in the manner previously described for effecting printing movement of the type bar I3.

When, however, the shield 56 is rocked counterclockwise to the position shown in Figure 3, its

front edge 6I projects into a cut-out portion 62 of the pawl 31 so as to underlie a shoulder 63 on the pawl and prevent the pawl from being lowered into operative engagement with the snatch roll 28.

.nected toa lever generally designated 69 pivoted I3 connecting the arms TI and I2. A spring I4 connected under tension between the upper lever arm II and a post 15 normally urges the lever 69, the link 68, and the line lock lever 65 to theirinactive positions as shown in Figure 2. Movement of the parts under the urge of the spring I4 is limited by engagement of a lug 16 on the lower lever arml'IZ with the frame A as shown in Figure 4. The lower lever arm I2 is connected to the rear end of a linkII, the front end of which is formed at I8 to embrace a stud I9 carried by an extension on the shield56. o

In operation, when the carriage approaches the end of its letter-spacing travel, the. margin stop abutment screw II engagesthe upper end of the line lock lever 65 so as to rock thelatter about its pivot 66 until the upper end of the lever 65 moves into contact with the center stop III, thereby positively arresting further movement of the carriage in the letter-spacing direction. This rocking of the lever 65 moves the link 68 toward the right as viewed in Figure 2 so as to rock the lever 69 counterclockwise as viewed in Figure 4, thereby pulling the link I? rearwardly or to the right as shown in Figure 1. This causesv the shield 56 to be rocked counterclockwise asviewed in Figures 1 and 3 so as to move theshield front edge BI underneath the shoulders 63 of the-pawls 3! included in the severalmechanisms for transmitting drive from the snatchroll 28 to the type bars I3. Consequently, the pawls 3! will be prevented from moving into engagement with the snatch roll 28, even though their respective restraining triggers 40 might be releasedby inadvertent depression of typing keys 44 after the carriage has been arrested in its line-end position. When the carriage has been moved toward the right so as to free the upper end of the line lock lever 65, the spring I4 will rock the lever 69 to restore the associated parts, including the shield .56, to their normal or inactive positions, permitting the pawls '31 to be moved into engagement with the snatch roll 28 to drive the type bars to printing position as described above.

Occasionally, it may be desirable to extend the typing for a limited number of characters beyond the normal line-end position in which the carriage is arrested by coaction of the margin stop screw II and the center stop I0. To permit this to be done, the center stop is mounted so as to be movable to a displaced position in which the center stop and the line lock lever 65 are disposed laterally outside of the path of the margin stop abutment screw I I. In the form shown, the center stop I I] is pivoted as at 8I on a framemounted bracket 82, so that, upon being rocked about the pivot 8|, the upper ends of the center stop and the, line lock lever are moved to the rear of the path of the margin stop screw II. Rocking of the center stop I0 for this purpose is effected by an arm 83 secured to the lower end of the center stop and a link 84 connecting the arm 83 to an arm 85 on a margin release key 86 pivoted as at 81 on the frame cross bar 26.

The shield 56 is adapted, when moved to the operative position shown in Figure 3, to prevent operation of all of the pawls 31 included in the mechanism for transmitting drive from the snatch roll 28 to the type bars. However, it is desirable that movement of the shield 56 to its operative position should not prevent the effecsitions.

asszcve tive operation of certain other or auxiliary typewriter instrumentalities. For example, the invention may be embodied in power-driven typewriters equipped with a carriage return mechanism such as the mechanism disclosed in the copending application of Henry J. Hart, Serial No. 21,476, filed April 16, 1948. Figure 2 shows a portion of a carriage return clutch releasing lever 88 which is adapted to be rocked by the abutment screw I2 on the left margin stop 9 when the carriage reaches the end of its return travel. The lever 88 may be connected to mechanism of the kind disclosed in the Hart application Serial No. 21,476 for interrupting the carriage return drive. It will be apparent that the mechanism for initiating operation of the carriage return drive should not be disabled or interfered with by the shield 53 when the carriage is at the end of its letter-spacing travel, that is, when the carriage is so positioned that the line lock lever 65 and shield 56 are in their operative po- For this reason, and in accordance with a further feature of the invention, the shield 56 is formed with a notch 89 aligned with the pawl 31a which is similar to the pawl 37 previouslydescribed, but which forms part of mechanism operated by the snatch roll 28 for initiating a power-driven carriage returning operation. If the shield 56 is in the operative position shown in Figure 3, the pawl 31a may drop through the slot 88 into efiective engagement with the snatch roll 28.

Some other typewriter instrumentalities also should not be disabled when the carriage is at the end of its letter-spacing travel. For example, the back spacing mechanism should be conditioned for operation regardless of the position of the carriage. For this reason the shield 56 may also be formed with a notch 96 located adjacent the pawl 31b forming part of the powerdriven back spacing mechanism.

The construction disclosed embodies the invention in the form now preferred, but it will be apparent that changes may be made without departing from the invention as defined in the claims.

I claim:

1. In a power operated typewriter or like machine, a plurality of type members; a power operated driving member; a plurality of actuators connected respectively to said type members and being normally disconnected from said driving member; interponents respectively mounted on said actuators and normally being disengaged from said driving member; key controlled means for sel ctively effecting initial movements of said actuators relative to said driving member; means responsive to such initial movement of an actuatcr for effecting movement of the interponent mounted thereon relative to said actuator and into engagement with said driving member for being driven thereby together with the associated actuator and type member; a normally ineiTective blocking member; and means for moving said blocking member into the paths of key-responsive movement of said interponents only for preventing engagement of said interponents with said driving member without obstructing key-effected initial movement of the associated actuators.

2. In a power operated typewriter or like machine, a plurality of type members; a power operated driving member; a plurality of actuators connected respectively to said type members and being normally disconnected from said driving member; interponents respectively mounted on said actuators and normally being disengaged from said driving member; key controlled means associated with said interponents for efiecting movement of the interponents selectively into engagement with said driving member for being driven thereby together with the associated actuators and type members; a blocking shield; means pivotally mounting said shield to rock from an ineffective position to a blocking position wherein an edge portion of said shield is disposed between parts of said interponents and said driving member; and means for rocking said shield into its blocking position for preventing engagement of said interponents with said driving member.

3. In a power operated typewriter or like machine, a plurality of type members; a power operated driving member; a plurality of actuators connected respectively to said type members and being normally disconnected fromsaid driving member; interponents respectively mounted'on said actuators and normally being disengaged from said driving member; key controlled spring means for moving said interponents selectively into engagement with said driving member for being driven thereby together with the associated actuators and type members; a normally inefiective blocking member; and means for moving said blocking member into the paths of movement of said interponents under the urge of said spring means for preventing said interponents from being moved by said spring means into engagement with said driving member.

4. In a power operated typewriter or like machine, a plurality of type members; a power operated driving member; a plurality of actuators connected respectively to said type members and being normally disconnected from said driving member; interponents respectively mounted on said actuators and normally being disengaged from said driving member; key controlled spring means for moving said interponents selectively into engagement with said driving member for being driven thereby together with the associated actuators and type members: a blocking shield; means pivotally mounting said shield to rock from an ineiiective position to a blocking position wherein an edge portion of said shield is disposed between parts of said interponents and said driving member; and means for rocking said shield into its blocking position for preventing said interponents from being moved by said spring means into engagement with said driving member.

5. In a power operated typewriter or like machine, a plurality of type members; a rotatable toothed driving member; a plurality of actuators connected respectively to said type members and being normally disconnected from said driving member; interponent pawls movably mounted on said actuators respectively and deployed in line adjacent said driving member; springs respectively urging said pawls toward engagement with said driving member; tri gers mounted respectively on said actuators for normally maintaining the associated pawls disengaged from said driving member; key controlled means for selectively moving said triggers to release the associated pawls to enable the pawls to be moved by said springs into engagement with said driving member for being driven thereby together with the associated actuators and type members; a normally ineffective blocking member extending in alignment with and adjacent to said pawls; and

means for moving said blocking member to effective position for preventing said pawls from 6. In a power operated typewriter or likema chine, a plurality of type members; a rotatable toothed driving member; a plurality of actuators connected respectively to said type members and being normally disconnected from said driving member; interponent pawls movably mounted on said actuators respectively and deployed in line adjacent said drivin member; springs respectively urging said pawls toward engagement with said driving member; triggers mounted respectively on said actuators for normallymaintaining the associated pawls disengaged from said driving member; key controlled means for selectively moving said triggers to release the associated pawls to enable the pawls to be moved by said springs 'into engagement with said driving member for being driven thereby together with the associated actuators and type members; a blocking shield; means pivotally mounting said shield to extend parallel to said driving member axis so as to rock from an ineffective position to a blocking position wherein an edge portion of said shield is disposed between parts of said pawls and said driving member; and means for rocking said shield into its blocking position for preventing said pawls from being moved by said springs into engagement with said driving member.

'7. In a power operated typewriter or like machine, a plurality of type members; a rotatable toothed driving member; a plurality of actuators connected respectively to said type members and being normally disconnected from said driving member; interponent pawls movably mounted on said actuators respectively and deployed in line adjacent said driving member, said pawls respectively having noses normally disposed just out of the path of the teeth on said driving member and shoulders projecting at an angle to said noses and being disposed farther from said path of said teeth than said noses; springs respectively urging said pawl noses toward engagement with said driving member; triggers mounted respectively on said actuators for normally maintaining the associated pawl noses disengaged from said driving member; key controlled means for selectively moving said triggers to release the associated pawls to enable the pawls to be moved by said springs to place the associated pawl noses in engagement with said driving member so as to transmit drive from said driving member to said type members; a normally ineffective blocking member extending in aligment with and adjacent to said pawls; and means for moving said blocking member to position on edge thereof between said pawl shoulders and said driving member to prevent said pawl noses from being moved by said springs into engagement with said driving member.

8. In a power operated typewriter or like machine, a plurality of type members; a power operated driving member; a plurality of elements connected respectively to said type members and normally being disconnected from said driving member, said elements being biased to move into engagement with said driving member; releasable means normally restraining said elements against the bias to prevent their moving into engagement with said driving member; key operated means for causing said releasable means to release said elements to enable them to be moved under the'bias into engagement with said driving member; a normally ineiiective blocking member; and means for moving said blocking member into blocking relationship with said elements for preventing the latter from moving under the bias into engagement with said driving member, said key operated means being free to be moved without being substantially restrained by said blocking member regardless of the position of the latter.

9. In a power operated typewriter or like machine, a plurality of type members; a power operated driving member; a plurality of elements connected respectively to said type members and normally being disconnected from said driving member, springs biasing said elements to move into engagement with said driving member; releasable means normally restraining said elements against the urge of said springs to prevent the springs from moving said elements into engagement with said driving member; key

operated means for causing said releasablegmeans;

to release said elements to enable them to be moved by said springs into engagement with said driving member; a normally ineffective blocking member; and means for moving said blocking member into blocking relationship with said elements for preventing the latter from being moved by said springs into engagement with said driving member, said key operated means being free to be moved without being substantially restrained by said blocking member regardless of the position of the latter.

10. In a power operated typewriter or like machine, a plurality of type members; an elongated rotatable toothed driving member; a plurality of actuators connected respectively to said type members and being normally disconnected from said driving member; interponent pawls movably mounted on said actuators respectively and deployed in line adjacent said driving member; springs respectively urging said pawls toward engagement with said driving member; triggers mounted respectively on said actuators for normally maintaining the associated pawls disengaged from said driving member; key controlled means for selectively moving said triggers to release the associated pawls to enable the pawls to be moved by said springs into engagement with said driving member for being driven thereby together with the associated actuators and .type members; an elongated blocking member, curved in cross section; means pivotally mounting said blocking member to extend along and partially embrace said driving member; means normally maintaining said blocking member in such position on its pivotal axis that it is incapable of preventing movement of said pawls into engagement with said driving member; and means for rocking said blocking member to position an edge portion thereof for preventing said pawls from being moved by said springs into engagement with said driving member.

11. In a power operated typewriter or like machine, a driving member which operates continuously when the machine is in use; a plurality of type members; a plurality of actuators connected respectively to the type members and normally being operatively disconnected from said driving member; spring loaded interponent pawls adapted respectively to connect said actuators to said driving member; keys operative respectively when depressed for effecting spring powered movement of said pawls into engagement with said driving member; a normally ineffective blocking member; and means for mov-- ing said blocking member into an efiective position for blocking the spring powered movement of said pawls and thereby preventing said pavvls from becoming engaged with said driving memher even though a key or keys be depressed.

12. In a power operated typewriter or like machine, a plurality of type members; an auxiliary mechanism; a power operated driving member; a plurality of elements connected respectively to said type members and said auxiliary mechanism and being normally disconnected from said driving member; key controlled means for effecting movement of said elements into engagement with said driving member for being driven thereby; a blocking shield; means mounting said shield to move from an ineffective position to a blocking position wherein an edge portion of said shield is disposed between said driving member and parts of those of said elements which are connected to said type members, said shield edge 1 2 portion being notched so that no part of the shield can be positioned eifectively between said driving member and the one of said elements which is connected to said auxiliary mechanism; and means for moving said shield to its blocking position.

13. In a power operated typewriter or like machine, mechanism as set forth in claim 12 in which key controlled springs are provided for moving said elements into engagement with said driving member.

JOHN F. KLOSKI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,358,263 Sundstrand Sept. 12, 1944 2,362,229 Yaeger Nov. 7, 1944

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