US2303879A - Typewriting machine - Google Patents

Description

Dec. 1, 1942. w. F. HELMOND 2,303,879

TYPEWRITING MACHINE Filed June 4, 1941 INVENTOR H g 5 M: 1/19, fix/nlwma BY K TTORNEY Patented Dec. 1, 1942 TYPEWRITDIG MACHINE William F. Helmond, Clinton, Conn., assignor to Underwood Elliott Fisher Company, New York,

N. Y., a corporation of Delaware Application June 4, 1941, Serial No. 397,546

I 6 Claims.

mechanism capable of smooth. action and more eflicient' and durable in heavy service.

A further object is to improve the organization of the elements 'of the line-space mechanism so as to obviate the need of parts projecting materially beyond the normal lateral limits of the carriage end structure, thereby enhancing the appearance of this region of the typewriter;

The present invention is in the nature of an improvement in the line-space mechanism shown and described in my Patent No. 2,172,008, dated September 5, 1939,

In the drawing: Figure l is a fragmentary plan view of the platen carriage unit, the outer casing thereof being broken away to reveal the line-space mechanism,

Figure 2 is an end elevation of the carriage unit with the casing partly broken away, and

Figure 3 is a perspective view, the line-space lever and cam apart from the mechanism.

In the embodiment of the invention illustrated, a platen 5 is removably mounted in the typewriter carriage, having its shaft 6 journaled at each end in bearings I releasably held in open sockets 8 of carriage end members 9. Each platen bearing is releasably held in its socket by a keeper device indicated generally at II], which may be substantially that shown in my prior patent. The keeper device includes a finger lever II, the upward swingingof which moves an arm I2 out of platen-holding position so that the platen assembly may be lifted bodily out of the carriage.

The line-space mechanism includes the usual ratchet wheel [3 mounted on the platen shaft 6 and normally secured thereto to rotate with the platen. A drive pawl I4 is arranged to be reciprocated in uniform lengths of stroke by means hereinafter described so as to engage a tooth of the ratchet wheel and thus rotate the platen a selected number of line spaces. The pawl I4 is actuated through the medium of a lever I5 on which the pawl is pivoted at I6. A looped spring II, the ends of which are articulated to the pawl I4 and lever I5, respectively, tends to swing the pawl clockwise about pivot H5. The efiective stroke of the pawl is variable to afford linespace selection, for which purpose the pawl has a cam I8 at its free end cooperating with a stud I 9 carried on a line-space selector lever 20. Lever 20 is pivoted at 2| on the carriage end. member and is swingable to a plurality of positions, each of which is defined by a detent spring 22 seating in one of a series of notches in the lever. At each setting of the selector lever 20, the stud I9 assumes a different position with respect to the pawl pivot I 6 and, accordingly, the cam l8 causes the pawl to engage a different tooth of the ratchet wheel, thus rotating the platen either one, two or three line spaces, depending on the setting of lever 20.

A line-space detent arm 24 is pivoted on the carriage end member at 25 and carries a roller 26 pressed by a spring 21 into detenting coaction with the ratchet wheel teeth. A second arm 28 of the line-space detent is arranged for engagement by a release lever 29 pivoted at 30 on the carriage, which lever, upon being swung from the normal position shown, cams the detent 24, 28 to swing about pivot 25, thus moving the roller 26 from the ratchet wheel and concomitantly bringing a yieldable brake shoe 3| mounted on the detent into frictional contact with a brake drum adjacent the ratchet wheel.

The pawl actuating lever I5 is pivoted intermediate its ends on a stud 33 secured at one end to the carriage end member 9, see Figure 1, and lever I5 has a laterally extending portion folded over to provide an outer bearing 34 aligned with a second bearing in the body of the lever, through both of which the pivot stud 33 projects in support of the lever. An outer; casing or cover member 35 is detachably secured by suitable means to the carriage end member 9 and is arranged to house and conceal substantially the entire line-space mechanism. The outer end of pivot stud 33 may be securedto the cover member 35 by a screw 36 passing through an opening in the cover member and threadedly engaging the pivot stud, a spacer collar being interposed between the cover member and lever I5. A coil spring 31 embracing the stud 33, between the outer bearing 34 and lever I5, has one end engaging a pin on the end member 9 and the other end engaging a pin on lever I5 so as to tend to rotate said lever clockwise about pivot 33.

Lever I5 carries a roller 38 at its forward end,

arranged to cooperate with a cam 40 on a linespace and carriage-return lever 4|. Pivotal support of lever 4| is afforded by ears 42 on the end member 9 disposed at the top and bottom faces of the lever hub 43, and by a pivot screw 44 extending through the hub and the ears, and threadedly retained in the latter. The cam 4c is formed on the periphery of the hub 43, as shown more clearly in Figure 3, and has an initial inclined portion 65 on which the roller 38 rests with the mechanism quiescent. From the initial portion 45, the cam face is inclined in a gradual ascent 46 transforming into a substantially flat horizontal portion 47. At the highest point of the cam, a stop pin 48 is arranged in such position that when the line-space lever is fully actuated, the stop pin 48 engages roller 38, In the usual operation of the typewriter, after the lever 4| assumes its fully actuated position after having line spaced the platen, the carriage is thereafter impelled in its return run by a continued manual pressure on the lever. Under this condition the stop pin 4.8 arresting lever M transfers the strain of returning the carriage directly to the pivot stud 33, thereby preventing distortion of the crooked portion of lever l5 and the drive pawl l4 which might otherwise result. It may be here noted that when the line-space mechanism is fully operated, a lug 59 on the drive pawl l4 engages a shoulder 5| on the carriage end member thus preventing a rotative overthrow of the platen, in the usual manner. A pin 52 on the pawl l4, engageable with a shoulder on lever l5, prevents excessive rotation of the pawl by spring mainly to facilitate assembly.

Lever |5 has its pivotal mounting 33 preferably at the upper forward region of the carriage end structure Where the line-space lever 4| is best mounted for convenient access by the typist. The lever pivot 33 may, therefore, be adjacent the hub and cam of the line-space lever to permit the use of a relatively short lever arm portion carrying roller 88. The operative connection between levers 4| and 5, as embodied in the cam and roller, allows the line-space lever hub and pivot to be arranged substantially at the same elevation on the carriage as the pivot of lever l5, thus reducing the visual height of the machine at this region. Likewise, the lever hub and cam may be confined within the minimum lateral limits of the carriage end structure required to accommodate the other elements of the line-space mechanism, thus obviating the need of having mechanism parts project materially from the normal confines of the mechanism casspace mechanism having a drive pawl and a. pivoted pawl carrier extending below the platen i axis to facilitate platen removal; means for actuating the pawl carrier including a part of said carrier arranged to reciprocate up and down to swing the carrier, and a manually operable linespace lever pivoted on a substantially vertical axis and having a cam cooperable with said carrier part.

2. In a line-space mechanism for a typewriter having a rotatable platen removably journaled in open bearings of a platen carriage, the linespace mechanism having a drive pawl and a lever pivoted intermediate its ends and having an arm carrying said drive pawl extending from the lever pivot below the platen axis to facilitate platen removal; means for actuating the pawl-carrying lever including a second arm of said lever having a roller adapted to be reciprocated up and down to swing said lever, and a manually operable linespace lever pivoted on a substantially vertical axis and presenting a cam having a substantially vertical lead for actuating said roller.

3. In a line-space mechanism for a typewriter having a rotatable platen removably journaled in open bearings of a platen carriage, the linespace mechanism having a drive pawl and a lever pivoted intermediate its ends and having an arm carrying said drive pawl extending from the lever pivot below the platen axis to facilitate platen removal, and spring means to restore said lever to quiescent position; means for actuating the pawl-carrying lever including a second arm of said lever having a roller adapted to be reciprocated up and down to swing said lever, and a manually operable line-space lever pivoted on a substantially vertical axis and presenting a single faced cam cooperable with said roller.

4. In a line-space mechanism fora typewriter having a rotatatble platen removably journaled in open bearings of a platen carriage, the linespace mechanism having a drive pawl, a lever pivoted-intermediate its ends and having an arm carrying said drive pawl extending from the lever pivot below the platen axis to facilitate platen removal, and spring means to restore said lever to quiescent position; means for actuating the pawl-carrying lever including a second arm of said lever having a roller adapted to be reciprocated up and down to swing said lever, and a manually operable line-space and carriage-return lever pivoted on a substantially vertical axis and presenting a single faced cam cooperable with said roller and terminating in a stop member engageable with the roller to limit the swing of said line-space lever.

5. In a line-space mechanism for a typewriter having a rotatable platen, a ratchet wheel, a drive pawl therefor and a pivoted pawl carrier; means for actuating the pawl carrier including a part of said carrier arranged to reciprocate up and down to swing the carrier, and. a manually operable line-space lever pivoted on a substantially vertical axis and having a cam cooperable with said carrier part.

6. In a line-space mechanism for a typewriter having a rotatatble platen removably journaled in open bearings of a platen carriage, the linespace mechanism having a drive pawl and a pivoted pawl carrier extending below the platen axis to facilitate platen removal; means for actuating the pawl carrier including a part of said carrier arranged to reciprocate up and down to swing said carrier, a manually operable linespace lever pivoted on a substantially vertical axis, and means for translating reciprocatory pivotal movement of said line-space lever into the up-and-down movement of said pawl carrier part.

WILLIAM F. HELMOND.

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