US2327423A - Typewriting machine - Google Patents

Description

Aug. 24, 1943. w. F. HELMOND TYPEWRITING MACHINE Filed March 21, 1941 2 Sheets-$heet l- Aug. 24, 194-3. w E HELMOND 2,327,423

TYPEWRITING MACHINE- Filed March 21, 1941 '2 Sheets-Sheet 2 INVENTOR Mil/19M A'b'fZ/l/O/VD ATTORNEY Patented Aug. 24, 1943 TYPEWRITIN G MACHINE William F. Helmond, Clinton, Conn, assignor to Underwood Elliott Fisher Company, New York, N. Y., a corporation of Delaware Application March 21, 1941, Serial No. 384,530

8 Claims. (Cl. 197-138) This invention relates to paper-feeding means for typewriting machines, for feeding, guiding and holding a work sheet at the front of the typewriter platen above the typing line. f

In front strike typewriters, the paper-feed bail is arranged to be movable from platen contact to facilitate the insertion of a work sheet and the making of erasures. It is highly desirable to have the bail displaceable in a forward direction from its normal position to a position well away from the platen so that a Wide opening is affordedinto which the top end of the paper may be received as it is fed around the platen. When the paper is thus installed, the operator, in a carefree manner, may restore the bail to its normal position. Thus, the operator is relieved of the necessity of threading the paper under the ball, as would be the case with bails which are shiftable to positions upwardly or rearwardly of the platen. It is also desirablethat the bail, while being restored, approach the platen in a direction generally tangential thereto, thus to eliminate any tendency are obviated in certain bail structures characterized by a fixed pivotal mounting for the bail, such structures, in order to aifordthe advantages of forward displacement and tangential return,

require arrangement of the bail pivots well above andforwardly of the platen, necessitating supports projecting objectionably from the normal carriage structure.

The present invention has among its objects the provision of a paper-feeding means having a bail which is adapted to be displaced forwardly of and well away from the platen and restored in a path generally tangential to the platen, and

which is a simple, compact, inexpensive and reliably operative structure.

Another object is to provide a front bail mountaxis, so that the arrangement and operation of.

other conventional mechanisms of the platen carriage are not encumbered. J

A further object is to provide a mechanism in which the bail moves constantly in parallelism with the platen and may be operated by a light finger touch for displacement or restoration, thus enabling the use of the mechanism with extra long, as well as the usual length, platen carriages.

A further object is to provide paper-feed mechanism, the bail of which, although having its mounting entirely forward of the platen, approaches the platen tangentially whilebeing restored, and on engaging the platen, moves around same a suitable extent to assure the elimination of any bulging of-the paper at the typing line; another object being'to: provide a bail of this character which will readily accommodate var ious thicknesses of manifold work pack, holding same snugly against the platen.

A further object is to provide a paper-feed bail mechanism, the associated spring of which urges the bail to either its normal or inactive positions with a relatively light, yet ample ten-' sion, to permit operationof the bail with a light finger touch; the coaction of the parts at paperfeed position being such that the springimparts an additional force to the bail, so translated as to press the bail radially against the platen and with ample yield to, accommodate manifold sheets. r 7

Other objects and advantages will hereinafter appear. v

In the drawings,

Figure 1 is a front elevational view of a typewriter carriage unit showing the bail mechanism of the invention, with the bail rod in extended position away from the platen,

Figure 2 is a transverse sectional view through the mechanism, taken on line 22 of Figure 1, with the bail rod in corresponding position,-

Figure 3 is a view similar to Figure 2 but showing the bail rod in normal position with the feed rolls against the platen and in an intermediate position,

Figure 4 is an end elevation of the bail mechanism in position similar to that shown in Figure 3, illustrating the action of the mechanism in accommodating manifold work sheets,

Figure 5 is an end elevation, illustrating a modified form of the invention, the bail being shown in extended and intermediate positions, and

Figure 6 is a view similar to Figure 4 but illustrating the modified form of the invention.

Theusual. cylindrical platen 8 shown, is

mounted for rotation on end members 9 of the platen carriage and cooperates with the usual bottom feed rolls it to feed a work sheet in the Well-known manner. The platen mounting shown provides for removal of the platen for the usual purposes, the overhead bail mechanism of the invention being particularly suited for association with removable platen arrangements in that the bail mounting may be entirely forward of the platen and thus will not encumber the platen mounting affording removal. Each carriage end member 9 includes a bracket H on which the supporting devices of the bail mechanism are mounted.

The bail rod indicated at I2 is; preferably square in cross section to provide surfaces for. let'- ter-space scales and which may accommodate feed rolls of the character shownv and described in my Patent No. 2,163,944, dated. June 27, 1939.

At each. end, of the rod. 52 is: rigidly secured a lever arm M, each. arm having: termed at,

one end. a ch'annel shap'ed lug to; which the bail rodz'is secured-L. The other end-101 each lever arm or bail: end. member [4 provides apivot i5 by which the lever arm; is articulated to a straight linkhl'ii pivotally mounted on thelcrracket H by a, stud 'i'.- AH: angle link 13 is connected to each lever armi I4 intennediate: the bail rod i2 and the pivot [5 by a. pivot 2-0: and these angle links. are pivotally mounted to the brackets l i by studs 21' carried on the brackets and: extending through.

elongate slots": 22 in the links. When the bail rod. 12 is. brought to extended: position away from the platen; as shown in Figures; 1 and 2; the angle links i8 cometorestagainst. stop pins 23 on the brackets ti. Sprmgs 2d are arranged toact upon. the straight links: so as to urge same to rotate about their studs I? in a counterclockwire direction as viewed in Figure- 2; Ihe

spring: 24*' is preferably fcrmedi'of a coil of wire embracing; the stud. ii, the end portions of the wirebeing oppositely extended to engage the link l fiand the bracket H respectively.

- The bail rod 12 and its and arms or members I 2 constitute a rigid bail or rectangular frame in moving between positions at or well away from the platen, moves fore and aft of the typewriter through aperpendicular plane intersecting the axis i5 of the bail. The extensible and collapsible-structure comprising the bail and supporting linkage controlsmovement of the bail toward the platen in a rearwardly swingin manner, while the bail is given a turning movement and its cross piece or bail rod 52 is constrained to take a substantially straight-line Q path toward the platen. The spring 24 resists the swinging movement of the bail until the bail has turned a predetermined extent and thereafter assists the swinging movement of the bail, tending to col lapse the linkage and thus urge the bail rod toward the platen. a

It will be seen that the bail mechanism at each end presents a three-arm linkage comprising the link [6, arm portion 25 and link 18, the arm portion 25 forming an intermediate or connecting member of the linkage. The coaction of the linkage elements however may be more readily understood by considering the mechanism as including first, the two-arm linkage I5, 25, and second, the two- arm linkage 25, 29, both linkages having as a common element, the linkage memher or arnrportion 25 ofthe bail [2,. 3.,

When. manual pressure is applied to the bail rod l2 in its extended position, Figure 2, the twoarm linkage is, 25 is being folded, during which the pivot I5 is moved in a clockwise direction about the. stud 5'! against the force of spring 24. The manual eiiort on the bail rod is continued until the linkage assumes a dead center position shown, in dotted outline in Figure 2. This dead center position is assumed when the second linkage 2,5,, 58' is in straight condition, that is, when the pivot 20 is on a straight line with the axes of pivot l5 and stud 2 i. When the linkage is moved, just beyond dead center position, the; force of spring 24 on the linkage mechanism tends to fold linkage 25, I18 and thus urges the bail rod 52 toward the platen to; the Figure 3 120-, si-tion Without further manual efiort. It will, therefore, be seen that the spring 24', although acting in a constant direction with respect to the, link i5 and its center of rotation I'Lhas the effect of an overthrow spring because of the coaction of the elements of the three-arm linkage in moving, from one side to. the other of the dead center position shown. To move the bail rod i2 from normal to extended positions, or vice versa, manual effort need be applied only to carry the mechanism just beyond dead center potion determined by the anglelink i3 engaging.

the. stop pin 23. In the normal position of the bail rod, Figure 3, the linkage it, 25 is folded and the spring 26, through the guiding action of link IS with the linkage elements i5, 2-5, bringsthe bail rod 12 in a substantially straight path to- Ward the platen, approaching the platen-in a direction generally tangential to its periphery. As

the, bail rod approaches the platen, the feed rolls i3 come into engagementwith the platen periphe cry or the work sheet therecn and roll over the platen for a short distance in a wiping action that tends to wrap the work sheet around the platen and thus eliminates any bulging of the sheet at the printing line The pivotiil of the linkage carries a pin Mwhich extends outwardly from the linkage to overlie the bracket I for cooperation with a shoulder 21 thereon, as shown in Figures 1 and 4. The normal position of the bail rod with the feed rolls l3 engaging the platen is determined by engagement of the pin 25withthe shoulder 21. This shoulder isso di-. rooted in relation to the platen axis that the pin 7 25, under influence of spring 24, is cammed in such direction as to press the feed rolls toward the platen in a direction generally radially thereof. i

The limited play of the linkage, afforded by the elongate slot 22, allows movement of the feed rolls radially away from the platen to accommodate manifold sheets. That is, the feed rolls may move toward the position thereof shown in phantom in Figure 4, at which a work pack 01' material thickness may be accommodated. Burthe axes of pivots l and in the normal con-- dition of the linkage, so that the spring is flexed pin 28 slides along the shoulder 21 correspond ingly, all against the force of spring 2% which,

acting through the. linkage, presses the feed rolls l3 constantly toward the platen.

It will be observed that'the pivots at each end or" the frame or bail I2, I 4 define a longitudinal axis on which the frame or bail is swingable and movable, in a sense, edgewise upwardly and downwardly, it being apparent that the link Hi constitutes mounting means' by which such movement of'the frame is" afforded. -t will also be observed that the pivots Ell at each end of the frame form a longitudinalaxis adjacent the bail rod l2, which aXis is caused, by the mounting means embodied in the link l t, to move in a path generally transverse to said edgewise or ip-3,114 down movement of the frame. The two links i 5, is thus form mounting means for the frame bail l2, M by which the latter is capable of a combined swinging and turning movement about axes longitudinal with respect to the frame. The effect of the spring is that ofurging the frame 12, 14 against said upward movement bodily, with the result that the bail rod i2 is caused to be yielolably held in either position at or away from the platen, depending upon which side of the dead center position the axis so of the bail is disposed. r

The modified form of the inve in Figures 5 and 6, presents a linkage mecha 1i-.;m and bail arrangement like that described for the first form. The principal "difference in the ified form resides in the type and arrangement of the spring means .acting upon the linkage to carry the bail rod to either its normal or extended positions. In place of the torsion spring in the firstiorm, a tension springflc is provided.

one end of which is anchored on bra not H by a stud the other being connected. to the linkage at the pivot 55. linurging the bail rod to either position, spring 223 acts upon the linkage in substantially theisame manner as does the torsion spring 24, namely tending to constantly resist movement of the bail bodily up; To effect this operation, it is necessary that the point of anchorage 29 of the spring. be located in a particular relation to the axes of pivots l5 and il with the linkage in dead center position as shown in dotted outline in vlili ure 5. Accordingly, the anchorage point jlil should be located on a straight line projected from the pivot point !5 with the linkage at dead center,'said line passing slightly below or to the left of pivot point ll, as viewed in Figure 5. In this way, spring 28 always exerts a force on the pivot 15 tending to turn the link It in a constant direction.

As will be apparent Figure 6, the arrangement of spring 28 has the additional effect of urging the bail rod i2 directly toward the platen when the linkage is folded to normal position. In this condition, the pin being engaged with the shoulder 2'1, also engages the spring 23 intermediate its ends causin the spring to be flexed longitudinally out of its normal straight condition. The force of spring 28 is thus translated directly to the pin 26 in such manner that the feed rolls it are pressed toward the platen by an extra force in addition to that imparted to the feed rolls by the spring tension acting upon the linkage at pivot 55. The spring anchorage 23 should, of course be located also in reference to by {pin 26, as described. Although in this application, there is specifi- "cally described, two embodiments which the invention may assume in practice, it will be understood that same are shown for the purposes of illustration, 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.

What is claimed is:

1. In combination, :a typewriter carriage, a platen thereon, a paper-guiding bail having a crosspiece and opposite end members, and means for guiding the crosspiece toward and away from the platen,'comprising devices mounting the bail on the carriage, having provision for effecting a swinging movement of the bail combined with a turning movement on an axis intermediate the extremities of the bail end members as the cross piece is'movedtoward the platen and simultaneously constraining the crosspiece to take a substantially straight-line course toward the platen. it 1 2. In combination, a typewriter carriage, a platen thereon, a paper-guiding bail having a crosspiece and opposite end members, means for guiding theicrosspiece toward and away from the platen, comprising devices mounting the bail on the carriage, having provision for efiecting a combined swinging and turning movement of the bail as the crosspiece is moved toward the platen and simultaneously constraining the'crosspiece to take a substantiallyjstraight line course toward the platen, and spring means resisting the bail in its swinging movement until the bail has turned a predetermined extent and thereafter assisting the bail in its swinging movement until the crosspiece is at theplaten.

3; 'In combination, a typewriter carriage, a

' platen thereon, a paper-guiding bail having a crosspiece and opposite-end members, means for guiding the crosspiece toward and away from the platen, comprising devices mounting the bail on the carriage, having provision for effecting a combined swinging and turning movement of the bail as the crosspiece is moved toward the platen and simultaneously constraining the crosspiece to take a substantially straight line course toward the platen, spring means resisting the bail in its swinging movement until the ball has turned a predetermined extent and thereafter assisting the bail in its swinging movement until the crosspiece is at the platen, and means for stopping the bail in its movement away from the platen, while the bail is maintained under the influence of the spring means.

i. In combination, a typewriter carriage, a platen thereon, and an extensible and collapsible structure comprising a crosspiece having end arms thereon providing an overhead bail for the platen, and links and connections for connecting the ball by its end arms to the carriage; said links and connections having provision for controlling movement of the bail toward the platen structure and urge the .crosspiece toward the-Q platen.

5. In a typewriting machine having a platei.

and a carriage; a paper-guiding bail including end arms and a rod connecting the arms; at

corresponding ends, means mounting said bail .onthe carriage and to the bail arm at a point remote from the bail rod, and a second link at each bail end pivoted on the carriage and to the bail at a point intermediate the bail rod and the first said link. V

6. In a typewriting machine having a platen and a platen carriage; a paper-guiding bail including end arms and aconneoting bail rod, means mounting said bail for movement to guide the bail rod in a normal path to or away from the platen, including a link at each bail end pivoted on the carriage and to the bail arm ad jacent its end for pivotal and edgewise movement of the bail, spring means yieldably resisting said edgewise bail movement in one direction, a second link at each bail end pivoted on the carriage and to the bail at a 'point adjacent the bail rod to guide said point in .a normal lineal path generally transverse to the edgewise movement of the bail, and a pin movable with the bail in a normal path. andengageable with a stop on the carriage to arrest the bail rod adjacent the platen, said stop extending transversely to. the normal path of said pin and said second link having provision for limited endwise movement to aiiord bail rod'movement in a direction transverse to its normal path.

7. In a typewriting machine having a platen V and a carriage; aVpaper-guiding bail including end arms and a connecting bail rod, means mounting said bail for movement to guide the bail rod in a normal'path to or awayfrom 'the platen, including a link at each bailiend pivoted on the carriage and to the bail arm adjacent its end for pivotal and edgewise movement of the bail, a second link at each bail end pivoted on the carriage and to the bail at a point adjacent the bail rod to guide said point in a normal lineal I path generally transverse to the edgewise move- 7 ment of the bail, means for limiting the extent of bail rocking movement to arrest said bail rod in positions at or away from the platen, said mounting means and limiting means having provision for limited movement of the bail rod in a direction transverse to its normal path, and spring means for resisting the edgewise ball movement and movement of the bail rod transverse to its normal path, said mounting means having a part engageable with'said spring means, with the bail rod adjacent the platen, to further resist movement of the bail rod in one direction transverse to its normal path.

S. In a typewriting machine having a platen and a platen carriage, a paper-guiding bail including end arms and a connecting bail rod, means mounting said bail for movement to guide the bail rod in a normal path to or away from the platen, including a link at each bail end pivoted on the carriage and to the bail arm adjacent its end for pivotal and edgewise movement of the bail, a tension spring interposed between the carriage and said mounting means to resist said edgewise bail movement in one direction, a second link at each bail end pivoted on the carriage and to the bail at a point adjacent the bail rod to guide said point in a normal lineal path generally transverse to the edge- Wise movement of the bail, and a pin movable with the bail in a normal path and engageable with a stop on the carriage to arrest the bail rod adjacent the platen, said stop extending transversely to the normal path of said pin and said second link having provision for limited endwlse movement to afford bail rod movement in a direction transverse to its normal path, said pin being adapted to engage said spring with the bail rod positioned adjacent the platen, whereby said spring directly resists movement of the bail rod in one direction transverse to its normal'path.

WILLIAM F. HELMOND.

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