US2302301A

US2302301A - Typewriting machine

Info

Publication number: US2302301A
Application number: US295295A
Authority: US
Inventors: William A Dobson
Original assignee: Underwood Elliott Fisher Co
Current assignee: Underwood Elliott Fisher Co
Priority date: 1939-09-16
Filing date: 1939-09-16
Publication date: 1942-11-17
Anticipated expiration: 1959-11-17

Description

Nov. 17, 1942; w. A. DOBSON TYPEWRITING MACHINE Fild Sept. 16, 1959 INVENTOR 'W/LL/A/V A. 00650 WW I ATI'ORNEY Patented Nov. 17, 1942 TYPEWRITDIG MACHINE William A. Dobson, Wethersfield, Conn., assignor to Underwood Elliott Fisher Company, New York, N. Y., a corporation ofDelaware Application September 16, 1939, Serial No. 295,235

1 Claim.

This invention relates to ribbon-iced mechanisms for typewriting machines, and more particularly to mechanisms of this character wherein the reversing of the ribbon feed is automatically efiected in the final travel of the ribbon.

The invention has among its objects the provision of an automatic reversing ribbon feed mechanism having a minimum number of lightweight parts in a compact and reliably operative organization particularly adapted for typewriting machines of the portable class.

Other objects of th invention are to provide a ribbon feed and reversing mechanism wherein the ribbon reversing control is adapted either for manual or automatic operation, and to provide an automatic ribbon reversing mechanism of substantially simplified structure and arrangement.

In its more specific aspect the invention provides a ribbon feed mechanism including slidably reciprocatory drive pawls cooperating with ratchet wheels of each of the ribbon spools; these driving pawls being connected to, and reciprocated concomitantly by, the rocking movement of a universal bail actuatable by any of the type actions of the typewriter- The pawl and ratchet mechanism of each ribbon spool may be controlled by a shiftable control member engageable with the driving pawl and which also carries a holding pawl and a driving pawl spring, these elements being so associated that upon shifting the control members concomitantly, the two pawls of one spool mechanism are disabled, while the pawls of the other spool mechanism are operatively set. The direction of shifting the control members corresponds substantially to the direction of ribbon travel so that these members may be directly connected for concomitant shifting by a link which may be so disposed relative to the path of ribbon travel as to be adapted for automatic ribbon reversing by having the link engageable by projections on the ribbon adjacent its ends.

Other objects and anvantages will hereinafter appear.

Certain features of the reversible ribbon-feed mechanism herein described form the subject matter of my copending application Serial No. 295,296, filed September 16, 1939, now Patent No. 2,282,994, issued May 12, 1942.

In the drawing,

Figur 1 is a perspective view of the preferred embodiment of the invention, including only the related portions of the typewriter mechanism, and

Figure 2 is a top plan view of same, omitting the type action" and the actuating universal bail.

In the embodimentof the'invention illustrated, a central type action of'the'system similar to that of an Underwood portable typewriter is shown, to illustrate by way of example the preferred manner of actuating the ribbon feed mechanism. Each type action includes a key lever 4 fulcrumed at 5 and having a'driving connection 6 to a sublever 1. Each'sub-lever is pivoted at 8 and is operatively connected by a link 9 to a type bar ill fulcrumed at H on a mounting segment l2. Each sub-lever 1 of the type action system includes a part such as a finger l3 engageable with a universal bar [5 extending across the typewriter and supported adjacent each end by arms fixed to a rock shaft I6 pivoted at "on the main frame of the typewriter.

The bar l4 and the arms 15 constitute a bail oscillatable universally" by any of the type actions. Articulated to each of the arms It: at I8 is a slide arm I9 having a guide slot at its opposite end riding upon a' stud 2l mounted on the main frame. Each of the arms l9 extends in a fore and aft direction of the typewriter and includes an integral upstanding pawl arm 22 formed at its upper end to provide a driving pawl 23. A spring 2 1 restores'the universal bail l4, IE to normalcy and thus returns the driving pawls 23 to initial position after the driving stroke.

The usual inking ribbon'25 traverses the printing zone of the platen through a ribbon guide 26 to and from suitable ribbon spools 2? removably carried on spindles 28 in the well-known manner.

Each ribbon spool spindle'has a ratchet wheel 30 arranged to rotate therewith and disposed to co; operate with the corresponding driving pawl 23 to effect travel on the ribbon. Each side wall of the typewriter main frame may include an inturned portion 31 providing a plate upon which each ribbon spool spindle 28 may be rotatably mounted. Shiftably mounted on each of the plates 3| adjacent each driving pawl 23 is a control member 32 preferably pivoted at 33 on the plate 3! and having an edge thereof extending alongside the driving pawl 23 for engagement therewith. At the free end of each control member 32 an upstanding lug 34 is formed to provide a mount for a bifurcated member 35 adjustably secured to the lug by a screw 35. Ihe member 35 provides, in an integral structure, a leaf spring 3'! and a holding dog 38 each formed of the tines of the member. In the operative setting of the control member 32, as shown at the left-hand ribbon spool, the holding dog 38 engages the teeth of its ratchet wheel 30 to prevent reverse rotation of same during the return stroke of the driving pawl 23. The leaf spring 31 of the bifurcated member 35 presses against the pawl 23 to yieldably hold same engaged with its ratchet wheel 30. Each control member 32 has a finger piece 48 extending laterally therefrom to project through the adjacent side of the type writer mask for access by the operator to manually reverse the direction of the ribbon feed, and the control members 32 are connected together by a link 4| extending across the machine for concomitant shifting of the members 32.

At least one of the control members 32 is yieldably held in eiiective and inoperative positions by a detent shown best at the right of Figure 2, which detent preferably comprises an arm 43 pivotally mounted at 44 on the plate 3! and urged by a spring 55 to press against an edge of the lug 34. The arm 43 carries a mound 36 having oppositely inclined edges coactive with the lug 34 so that in the condition of the parts as shown in Figure 2 the right-hand control member 32 is detented at its inoperative position, and when the lug 34 is pressed to the opposite side of the mound 46, the control member is detented at its efiective position. It will be seen that when the furthermost projecting finger piece 43 is manually pressed, the direction .of ribbon travel is reversed in that both control members are conjointly swung so that the one feed mechanism is rendered operative while the other feed mechanism is disabled.

In the operative condition of either feed mechanism, the driving pawl 23 under influence of its spring 31 engages its ratchet wheel 38 and the holding dog 38 is also engaged therewith, so that as the pawl arm [9 is reciprocated incident to the depression of a key lever, the spool 21 is rotated to wind the ribbon 25 thereon. As the control member 32 is swung to the inoperative setting, the holding dog 38 is moved to a position free of its ratchet wheel 39, and the driving pawl 23, being disposed between its spring 31 and an edge of the control member 32, is also moved to inoperative position free of the ratchet wheel. It will be observed that the pawl-carrying end of each arm 22 assumes a motion laterally of the typewriter in moving between effective and inoperative positions, this motion being accommodated at the stud 2| which is of such length as to permit the slot 20 to slide axially thereon.

In that the control members 32 are shiftable laterally of the machine to efiect reverse travel of the ribbon, that is, in the general direction of ribbon travel, the arrangement is particularly suited for an automatically efiected ribbon reversal. The link 4| is provided with two integral projecting members 4'! adjacent each of the ribbon spools 27, forming loops 48 disposed in the path of travel of the ribbon and through which the ribbon passes in traversing the printing zone. Adjacent each end of the ribbon 25, a projection such as a rivet 49 is afiixed thereto so that as the ribbon is unreeled from one of the spools the projection 49 abuts the loop 48 and the further travel of the ribbon pulls the link laterally so as to concomitantly swing both the control members 32 and thus reverse the positions of the driving pawl 23 and the holding dog 33 of each feed mechanism.

It will be seen from the foregoing that the invention provides an automatic reversing ribbon feed mechanism having a minimum number of I lightweight parts in a compact and reliably operative organization. Each of the elements in the right and left feed mechanisms may be identical in form, it being required only to make the correspondng parts in pairs of opposite hand. The link connecting each mechanism is also adapted for economic manufacture, in that same may be readily formed of a strip material such as wire having the ribbon-engaging loops in tegrally formed thereon. The arrangement of the parts is such that the machine may be equipped for either or both the automatic and the manual ribbon reversing, in that the control members, being shiftable laterally in the general direction of ribbon travel, are adapted for concomitant actuation by the connecting link and, being arranged in proximity to the side walls of the machine, may include the required finger pieces for the manual reversing.

Although in this application there is specifically described one embodiment which the invention may assume in practice, it will be understood that same is 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 claim.

What is claimed is:

In a ribbon feed mechanism for a typewriter; means operable to reverse the direction of ribbon feed, comprising a one-piece wire link having bent-off pivot members at each end supporting the link for endwise shifting and presenting integral upstanding loop portions intermediate its ends through which a ribbon may pass and adapted for engagement by ribbon-carried means, to actuate th reversing means, the pivot members holding said link non-rotative to maintain the loop portions in upstanding position.

WILLIAM A. DOBSON.