US2055561A - Typewriter - Google Patents

Description

Sept. 29, 1936.

| G. SAUND-ERS TYPEWRITER Filed June 22, .1934

I NV ENTOR Zyman G. Sad/Idem Patented Sept. 29, 1936 UNITED STATES PATENT OFFICE TYPEWRITER Application June 22, 1934, Serial No. 731,798

'1 Claims.

This invention relates to typewriters and it has to do more particularly with escapement operating mechanism therefor.

One of the objects of the invention is to provide an improved typewriter construction.

Another object is to provide an improved escapement operating mechanism.

A further object is to provide improved space bar mechanism.

A more specific object is to provide an improved arrangement wherein both a partial and a full escapement of the carriage takes place upon downward depression of the space bar whereby correct spacing of letters following operation of the space bar is insured.

Other objects and advantages will become apparent as this description progresses and by ref erence to the drawing wherein,--

Figure 1 is a rear, skeleton-like, perspective view of a machine showing one arrangement of escapement and space bar mechanism in normal position and embodying my invention; I

Fig. 2 is a fragmental left side view of the structure shown in Fig. 1 and illustrating the parts in their positions when the space bar is almost fully depressed and the initial or partial escapement action has taken place; and

Fig. 3 is a view similar to Fig. 2 except illustrating the parts in their positions with the final escapement action completed.

The invention has utility in various forms of typewriters; and it is to be understood that, although only those parts necessary for an understanding of this invention have been illustrated in detail, the typewriter mechanism as a whole includes all those parts requisite to a complete typewriter, including a traveling paper carriage, a platen and type bars.

Escapement mechanism 1 includes an escapement wheel supported by I a shaft 2| which is rotatably supported in any suitable manner. The escapement wheel 20 is drive-connected to the shaft 2! by an internal pawl (not shown). The shaft 21 supports a pinion 22 that is in constant mesh with a rack 23 carried by the paper carriage (not shown) which may be driven in the direction of the arrow (Fig. l) by the usual spring-drum structure (not shown) or other suitable means. With this 5 arrangement the escapement wheel 2|] is constantly urged in clockwise direction to space the carriage toward the left as viewed from the front of the typewriter, but movement of the escapement wheel 20 in this direction is opposed by a pair of escapement dogs 24 and 25.

The escapement dogs 24 and 25, the first of which is movable and the other fixed, as will be well understood, are carried by an escapement block 26 rigidly secured to a shaft 21 having its opposite ends journaled in any suitable fashion in the frame work (not shown) of the machine. Escapement movement of the carriage is permit-. ted by rocking motion of the escapement block 26 under the control of the shaft 21. 20

The escapement dogs 24 and 25 are mounted upon the block 26 in a laterally spaced and offset fashion and the movable dog 24 is normally engaged with the tooth (for example the tooth 28) of the escapement wheel. Rocking movement of the escapement block 26 in counterclockwise direction releases the dog 24 from the tooth 28 permitting the escapement wheel 20 to rotate in clockwise direction into engagement with the stationary dog 25 which, by the said rocking of the escapement block,'is moved into the path of the tooth 28. In this manner a partial escapement action is accomplished, the rack 23 and paper carriage being moved to the left a part space.- Upon disengagement of the dog 24 from the escapement wheel, a spring (not shown) moves this dog clockwise (as viewed in Fig. 1) to a position directly opposite the space between the escapement wheel tooth 28 and the next succeeding tooth (for example, the tooth 29) so that, when the escapement block 28 is rocked clockwise or restored to its normal position, the escapement dog 25 will be disengaged from the tooth 28 and the spring dog 24 will be moved into active position in front of the next succeeding escapement wheel tooth 29. As the dog 25 is released in the manner stated, the escapement wheel 20 is rotated further in clockwise direction until the succeeding tooth 29 engages the dog 24 and seats the same against the escapement block V 26, thus completing a full escapement movement or movement of the paper'carriage one full space to the left.

Rocking movement of the shaft 21 by the space bar I0 is accomplished through a lever arm 30 fixed upon the shaft 21. The lever 30, and in turn, the shaft 21 are constantly urged in clockwise direction to normally position the escapement block 26 (Fig. 1) by a spring 3| connected to the upper end of the lever arm and to a suitable fixed support (not shown) on the machine. Rocking movement of the lever 30 in clockwise direction is limited by a stationary, frame-carried stud 32. The forward face of the stud 32 is provided with a fiat-contact surface adapted to be engaged bythe lower end portion of the lever 30 providing a stop for more positively limiting the escapement block to its predetermined normal position of Fig. 1.

Space bar mechanism In prior typewriter constructions wherein the character keys and the space bar are depressed and then released in order to accomplish a full escapement action and spacing of the paper carriage, it is quite customary for a speedy operator to depress a character key immediately following a space bar operation and before the carriage escapement action under the control of the space bar has been fully completed. The result of this is that the first letterprinted after such an operation is incorrectly spaced. A condition of this character is entirely avoided by this invention in a very simple and inexpensive manner and with the use of a minimum number of operating parts. More particularly, this invention provides for both the partial and full escapement movement of the paper carriage on the downward depression of the space bar and before the latter is released, whereby a complete carriage escapement is effected by the time a character key can be depressed following a space bar operation.

The space bar mechanism includes the space bar I supported by a pair of side arms 40 that are fixed to a cross rock shaft 4| journaled in the side frames (not shown) of the machine in any suitable manner. The rock shaft 4| supports an upwardly extending arm 42, the upper end of which, as at 43, is pivotally connected to an escapement operating link 44.

The escapement operating link 44 extends rearwardly in a generally horizontal direction and, at its rear end, is provided with a forked, angular cam-like member 45 that receives a reduced portion 46 of the fixedistud 32. The link 44 is constantly urged upwardly by a spring 41 connected to the forked member 45 and to a stud 48 carried by the escapement operating lever 30, so that thelower fork arm 49 of the member 45 is yieldably urged upwardly into engagement with the stud portion 46. The forked member 45 of the link 44 extends upwardly from the horizontal at such an angle that, as the link 44 is moved forwardly under the control of the space bar Hi, the rear end of the link is lowered by the camming action between the angular forked member 45 and the stud 46.

The rear end of the link 44 is also provided with a horizontal, rearwardly-extending branch 50 disposed beneath the cam member '45 and having a lateral extension or lug that is adapted to extend behind the lower end portion of the lever arm 30. In the normal position of the parts, as shown in Fig. 1, the lug 5| is so positioned that it is substantially in engagement with the rear edge of the lever 30 at such a height thereon as to positively engage the same. It will be seen, therefore, that by depressing the space bar It, the shaft 4| and arm 42 are rocked clockwise and the link 44 is shifted forwardly; and as rocks the lever 30 in counterclockwise direction to initiate the escapement action and permit a partial escapement movement as hereinabove described.

As the space bar I0 is depressed and the link 44 is shifted forwardly to initiate the escapement action, the camming action afforded by the stud 46 and the forked member 45 moves the rear end of the link 44 downwardly or counterclockwise until the parts reach the position illustrated in Fig. 2 wherein the positive engagement between the lug 5| and the lower end of the lever 30 is substantially released. As the depression 01' the space bar I0 is continued, and it is fully depressed as shown in Fig. 3, the lug 5| is shifted downwardly still further by the camming action above described to a point below the lever 30. By this action the lever 30 is fully released and it is rocked clockwise under the urge of the spring 3| thereby rocking the escapement block 26 clockwise and restoring the escapement mechanism to its normal position, whereby a full escapement action is completed in the manner above more particularly set forth.

The spacing between the arms 49 and 52 of the forked end 45 or the link 44 is sufficiently great to permit considerable up and down movement of the rear end of the link 44 so that the foregoing action may take place in a free and unrestricted manner. As the lever 30 is restored to normal position' with the space bar Ill still in its depressed condition (Fig. 3), the lower end of the lever 3|] engaging the upper part of the lug 5| rocks the rear end of the link 44 downwardly to a slightly additional extent, this action being accommodated by the spacing of the forked arms 49 and 52.

When the space bar is released following the foregoing action, suitable spring means (not shown) in addition to the spring 41 moves the latter upwardly and restores it to normal position. As the space bar |IJ moves to its normal or raised position, the link 44 is shifted rearwardly to its position wherein the lug 5| is disposed behind the lower end of the lever arm 30 and the spring 41 returns the forked member 45 and the lug 5| to their normal positions shown in Fig. 1.

The operation and advantages of the invention will be readily understood from the foregoing description. Proper escapement action is insured under all key and space bar depression conditions. The proper spacing of the carriage is accomplished upon depression of the space bar regardless whether the space bar is held in depressed condition or is released, and in that case also the continued depression of the space bar does not affect successive operation of the character keys. The advantages first above stated are attained with but very few operating parts that are simply constructed and are reliable and highly efilcient in use. Operating speed is materially increased.

It will be understood that while I have shown only one form of structure embodying the invention, other changes in details and arrangement of parts may be made without departing from the spirit and scope of the invention as defined by the claims that follow.

I claim:

1. In a typewriter, escapement mechanism ineluding a lever arm rockable back and forth between predetermined limits to effect a complete escapement movement of said escapement mechaosasea cluding a lever member rockable between pre-' determined limits to effect one complete escapement operation, a space bar, and means actuated by said space bar for effecting one complete escapement movement upon depression oi said space bar including a link member bodily shiftable in longitudinal direction toward the space bar by depression of said space bar, means carried bysaid link member and engageable with said lever memher to rock the latter in one direction when said link member is shifted longitudinally, a stationary cam element, means carried by said link and en- I gageable with said cam element for moving said first means out of engagement with. said lever member as said link is shifted in said one longitudinal direction, and means operative independently of said space bar as said first means is disengaged from said lever member for moving said lever member in an oppositedirection to its normal position. 3. In a typewriter, escapement mechanism including a; lever arm rockable between predetermined limits for effecting escapcment movement of said escapement mechanlsm, a stationary cam member, a space bar, and means for effecting escapement movement of said escapement mechanism as said space bar is depressed including a link member shiftable toward said space bar as said space bar is depressed, anactuating element on said link member engageable with said lever arm for rocking the latter in one direction as said link is shifted by depression of said space bar, a cam element on said link member eng'ageable with said cam member as said link member is so shifted for depressing the latter and releasing said actuating element from said lever arm, means for rocking said lever arm back to normal position upon release of said actuating element and while said space bar remains depressed, said actuating element and said lever arm being automatically 'returned to operative relationship as said space baris released. i

, '4. In a typewriter, escapement mechanism, a

1 space bar, a member rockable back andforth to effect escapernent movement of said escapement mechanism, a second member shiftable by depression of said space bar, a stationary member, means on said second member positively engageable with said rockable member during a predetermined extent of depression of said space bar,

, positive means on said second member constantly e sed with said stationary member, and opera- -tive as said predetermined extent of space bar depression is exceeded-to shift .said first means out of engagement with said first member, means operative as said first member and first means are disengaged to rocksaid first member back to its normal position and complete an escapement movement, and means operative to restore said space bar to its raisedposition and said first memf her and said first means to their operative post time as said space bar is released.

5. In a typewriter, escapement mechanism th eluding a recs. member rockable back and foirtli between predetermined limits to efi'ect a complete escapement movement oi said escapement mecha= nism, a space bar, and connections between said space bar and rock member whereby a complete escapement movement is effected upon depression of said space bar, said connections includmg a link longitudinally shiftable by depression of said space bar, a stationary member, a lug on one end of said link member engageable said rock member for rocking the latter as said space bar is depressed, a iorked member on the'eid of link member and straddling said stationary mem=- her, said forked member being constructed and arranged to engage said stationary member and shift said link member downwardly as link member is shifted longitudinally to thereby dis disengaged therefrom to complete a full escapw merit movement of said escapement mechanism.

6. In a typewriter, escapement mechanism in= eluding a rock shaft having a rock arm project-=- ing therefrom. and rockable back and. forth be== tween predetermined limits to eflect a complete escapement movement of-said escapement mechanism, a space bar, a link connected to said space bar for longitudinal shift movement as said space bar is depressed, a laterallug on' the end of said link disposed normally behind the end portion of said arm and adapted to engage and rock the latter in one direction to effect a partial escapement movement as said link is shifted, a stationary cam element, another cam element on the end of said link adjacent said lug and engaged with said stationary cam element to shift said lug toward and beyond the end of said arm as said link is shifted, and means rocking said arm back to normal position as saidlug is moved beyond the end of said am to effect a complete escapement movement.

'7. In a typewriter, escapement mechanism-including a rock shaft having a rock arm projecting therefrom and rockable back and forth between predetermined limits to eflect' a complete escapement movement of said escapemcnt mechanism, a space bar, a link connected at one end to said space bar and having its other end projected horizontally and terminating in an upwardly turned forked portion having vertically spaced fork arms,

astationary member aligned with the horizontal portion of said link and received within'said forked portion, means yieldably urging the lowermost of said fork arms into engagement with said stationary member, a branch member onthe end of said link beneath said forked portionand hav ing a lateral extension Projecting behind saidrock arm for rock movement of the latter as said link is shifted by depression of said space bar, said forked portion of the link and saidstationary member operating to shift the adjacent end of saidlink downwardly and to disengage said lateral extension and rock arm as said space bar approaches its fully depressed condition, and means' rocking said rock arm back to normal position as J the latter is released from said lateral extension to completethe cscapement movement while said space bar remains depressed.

- .LYMAN G. SAUNDERS.

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