US2498781A - Ribbon vibrating mechanism for typewriting machines - Google Patents

Description

Feb. 28, 1950 E. WISE 2,498,781

RIBBON VIBR ATING MECHANISM FOR TYPEWRITING MACHINES Filed Jan. 26, 1946 M INVENTOR v ELMER L.W/J

WM ATTORNEY Patented Feb. 28, 1950 RIBBON VIBRATING MECHANISM FOR TYPEWRITING MACHINES Elmer L. Wise, Bridgeport, Conn., assignor to Underwood Corporation, New York, N. Y., a corporation of Delaware Application January 26, 1946, Serial No. 643,509

2 Claims. :(Cl.197152) the types. In the use of a bichrome ribbon, the

inaccuracy in the action of the ribbon vibrating mechanism often causes a letter or figure to be printed partly in a color different from that of the main body of the imprint.

Certain objects of the present invention are to improve the construction and mode of operation of ribbon vibrating mechanisms for typewriting machines and to produce a ribbon vibrating mechanism for typewriting machines which is constructed to locate accurately the ribbon in a predetermined position for contact of the type therewith both when the mechanism is comparatively new and also after the parts become worn by long continued use.

Another object of the invention is to provide typewriting machines with a ribbon vibrating mechanism which will avoid underthrow as well as overthrow in the projection of the ribbon into position for engagement of the types therewith.

With the above objects in view the invention consists in a ribbon vibrating mechanism embodying the novel and improved features, construction, and combinations of parts hereinafter described and particularly pointed out in the claims,the advantages of which will be readily understood and appreciated by those skilled in the art.

The invention will be clearly understood from the accompanying drawings illustrating a construction embodying the invention in its preferred form and the following detailed description of the construction therein shown.

The invention is illustrated in this application as embodied in a typewriting machine of the so-called Elliott-Fisher type provided with a substantially flat platen and with typewriting mechanisms in which each of the types is projected downwardly into engagement with thework sheet supported on the platen at the end of a downward stroke of the type bar. It is to be understood however, that the invention is not limited to machines of the Elliott-Fisher type but that certain fit features thereof may be embodied with advantage in other types of machines.

In the drawings:

Fig. 1 is a view in vertical section taken through the type head and line space frame of a machine of the Elliott-Fisher type and illustrating particularly the ribbon vibrating mechanism,

Fig. 2 is a detail view in side elevation illustrating a portion of the mechanism shown in Fig. 1 with certain of the parts in different positions,

Fig. 3 is a detail plan view illustrating certain parts of the ribbon vibrating mechanism shown in Fig. 1, and

Fig. 4 is a view similar to Fig. 3 illustrating certain of the parts in different positions.

The invention is illustrated in this application as embodied in a machine of the Elliott-Fisher type such as that illustrated and described in the patent to Foothorap No. 1,904,127, dated April 18, 1933. This machine comprises a platen frame provided with side rails connected together in spaced. relation by cross bars and a substantially flat platen mounted for vertical movement in said frame. Upon the side rails of the platen frame is supported a line space frame movable forwardly and rearwardly upon the upper edges of said rails to line space the type carriage with relation to the platen. The construction above described is fully and clearly illustrated and described in said Foothorap patent.

Upon the line space frame is mounted a type carriage or head indicated as a whole at 2 upon which are supported the usual series of type bars each carrying one or more types for engaging the work sheets supported upon the platen. The line space frame is provided with front and rear rails 4 and 6 and the type carriage is provided with front and rear wheels or rollers 8 and 9 respectively for engaging said rails to support the carriage for movement in letter spacing and return directions. The type bar mechanisms may have the construction and mode of operation of the type bar mechanisms illustrated and described in the patent to Foothorap No. 1,251,361 dated December 25, 1917 in which said mechanisms are operated by the fingers of the operator or the type bar mechanisms may be constructed and operated as illustrated and described in the Fatent to Sundstrand No. 2,370,505 dated February 27, 1945, in which said mechanisms are operated by power.

The present machine is provided with a ribbon supporting and vibrating mechanism having a construction, arrangement and mode ofopera tion similar in many respects to that illustrated and described in the patent to Foothorap No. 1,286,573 dated December 3, 1918. As illustrated and described in the latter patent, the ribbon indicated at H3, is supported upon ribbon spools mounted at the ends of the type carriage and in passing from one spool to the other'is threaded through a ribbon vibrator indicatedat. having.v guides 2 through which the ribbon U is threaded. The ribbon vibrator II is mounted to slide forwardly and rearwardly in guides carriedby the bracket 13 attached, forwardly of the printing point, to the cross bar l4 forming a part of the frame of the type carriage. The vibrator-car.- ries a pin l5 projecting upwardlytherefrom which engages in a guideway l6 formed in the bracket i3 and the bracket is formedwith spaced arms I! having downwardly bent flanges |8 formed with slots in which engage the inwardly directed flanges 9 formed on the vibrator.

The: ribbon'is' provided with a rear strip B impregnated with ink. of. one color and with a forward strip D impregnated with ink of another color. Usually the rear strip'is impregnated with black ink and the forward strip with red ink as shown.

The mechanism for reciprocating the ribbon vibrator is constructed and arranged to move the vibrator rearwardl to a predetermined position during each reciprocation of the vibrator. The vibrator is moved rearwardly to one predetermined position. for printing with the rear strip or band of the ribbon and is moved rearwardly to a greater extent to another predetermined position tolocate-the forward strip or band of the ribbon in position for printing.

To prevent overthrow of the ribbon vibrator-a mechanismhas. been provided in Which stops respectively have been placed in the path of an element carried; by the ribbon vibrating. mecha-' nism to limit the movement of the ribbon vibrator into'typing position. The stops are not normally operative during the action ofthe ribbon vibratingmechanism but are. only engaged where there is a tendency of the ribbon vibrating mechanism v to overthrown Such a mechanism is shown and described in the: patent to Foothorap No. 1,286,573, dated December 3, 1918.

In the present construction, the ribbon. vibrat ing mechanism comprises an-oscillatory lever 20 pivoted upon a stud 2| carried. by the type carriage and. formed with aslot. 2.2. in which engages a pin. or stud 24 projectin upwardly from the. ribbon vibrator H. In order to limit the movement. of. the lever 20 about the stud 2!. in. a counterclockwise direction, Figs. 3' and 4, to project the vibrator into typing position, a pin 28 is mounted upon the left hand arm of the lever 20, Figs, 3 and 4, andprojects downwardly therefrom into. a slotSfl. in. a stop member 32 fixed to the lower end. of a vertical rod or rock. shaft 34v mounted in hearings in the deck 36 and the arcuatev plate 38. of the frame. of the type head. The-stop member 32'is adjustable alternatively. in the position shown in. Fig. 3 or in that shown in Fig. 4. With the stop member adjusted in the: position shown. in- Fig. 3, the. movement of the lever 2!] in .a counterclockwise direction is limited by the engagement of the pin 28- with. a shoulder 35iformecl on thestop member. With the stop member 32 adjusted in the position shown in Fig. 4 the movement of the lever 20 in a counterclockwise direction islimited by the engagementot the. pin 28 with a stopface 49 on the. stop member; -When thepin 281s. engaged. with the shoulder 39 to limit the projecting movement of the ribbon vibrator into typing position, the ribbon vibrator is accurately located in position for the engagement of the types with the central portion of the rear strip B of the ribbon having ink of a certain color applied thereto as shown in Figure 3; The printing point is. indicated dia grammatically Figure 3 of the drawing at C. When the projecting movement of the ribbon vibrating mechanism is limited by the engagement of the. pin 28 with. the stop face 40, the vibrator I is located accurately in position for the engage ment of the types with the central portion of the forward strip. D of the ribbon which is impregmated with ink of another color as shown in Figures. This figure also shows the printing point diagrammaticallyat. C.

The mechanism for oscillating the lever about the stud 2| comprises a lever 4| pivoted at 42 upon a bracket 43 attached to the underside of the; deck 36;. The-lever 4|: isacted upon bya spring 44 which tends tov swing, the same in a counterclockwise direction. Upon the lower. end of the. lever 4| is pivoted a bell. crank lever 45 upon a1stud46 and this bellcrank is acted; upon by a. coiled spring 48- which normally maintains the bell crank in, the position with relation to the lever 4| shown in Figure- 1- in which. a stop pin- 50' carried by the bell crank engages av stop arm 52 onthe lever 4|. Thebellcrank 45 is connected by a. link 54 with the left hand, end of. the lever 20,

said. link. having a downwardly extending pin 56 which engages in an. opening in the lever.

The mechanism. for oscillating the lever 4| is I similar tothemechanism'. for oscillating the corresponding lever in the'machine shown and described in the patent to Foothorap No. 1,286,573 and the amplitude of. movement of the lever 4| is adjusted by a mechanism corresponding to. that shown in said. patent as the. stop member 32 is adjusted. respectively in the. positions shown inv 32 adjusted as shown inFigure 3, the movement. of the vibrator mechanism is limited by the engagement of the pin 28 with. the stop 38- and the movement. of the lever 4| continues thereafter to some extent, the bell crank 45 then swinging about its pivot 46. withrelationv to lever 4|, against the action of spring 48. as shown in Figure 2. With the stop member 32 adjusted. as. shown in Figure 4, the. movement of the ribbon vibrator mechanism is limited by the engagement of the pin 28 with thestop and the movement of, the lever 4| continues thereafter to a certain extent, the bell. crank then swinging about its pivot. 46 with relation to lever 4| against the action. of the spring 48 in. a manner. similar. tothat shown in.

Figure 2.. As the lever 4| swings back. to the right, Figure. 1,.thebell crank 45 first swings,

about the stud. 46 .in a directiontoengage the stop pin ill-with thestopprojection 52 and after link 54 swings the lever 20. to move back to. its forward position.

With the. above construction. there will be, no;

overthrow or-underthrow of. the. ribbon vibratorthe vibrator-being'ilocated aocurately iir po mechanism adjusted sition for typing with-each -adjustment of the stop member 32. Also, sincethe bell crank 45 yields immediately upon the engagement of the pin 28 with one of the stops o'nthe'sto'p' member 32 during the movement of the vibrating mechanism to project the vibrator II rearwardly into pperating position, there is no particular; strain 'put upon any of the parts during this action.

v As above indicated,'themachine is'provided with mechanism for actuating the lever-4I from thejtype bar mechanism which has a construction, arrangement and mode of operationsimilar to the corresponding mechanism shown and described in the patent to Foothorap No. 1,286,573 referred to above. In the present construction, however, there is no provision for enabling the vibrator to be held in its forward position during the actuation of the type bar mechanisms in the cutting of stencils.

The lever extends upwardly from its pivot 42 and is formed with a slot 58 in which engages a pin 60 projecting laterally from the left hand end of a link 62 connected at its opposite end at 64 to a downwardly extending arm 66 fixed to a rock shaft 68. The vertical position of the pin 60 in the slot 58 is controlled, to control the amplitude of movement of lever M, by a shifter I mounted for vertical movement upon a shifter guide bracket 12 fixed to the side plate I4 of the type head, this shifter having substantially the same construction as the corresponding shifter shown in Foothorap patent No. 1,286,573. The shifter is provided with spaced plates one of which is shown at I arranged on opposite sides of the shifter guide I2 and connected by pins I6 engaged in a slot I8 in the shifter guide. One of the plates of the shifter is provided with a cross slot 80 in which engages the pin 60 fixed to the adjacent end of the link 62.

The position of the shifter upon the shifter guide 12 is controlled to control the position of the pin 60 in the slot 58 by mechanism comprising a lever 82 pivoted at 84 upon a rod extending across the type head, said lever having at its forward end, a slot 86 in which engages a pin 88 extending from one of the plates of the guide as shown in Figure 1. The rear end of the lever 82 is connected by a link 90 with the rearwardly extending arm 9| of a lever 92 pivoted on the shaft 94 supported at its ends on the frame of the type carriage. The lever 92 is provided with a second arm 96 having an inclined or cam face 98 arranged to be engaged by a pin I00 mounted on a key lever I02 pivoted on a shaft I04 extending across the rear of the type carriage. The key lever I02 is normally held in elevated position by a coil spring I00 and the upward movement of the lever under the influence of the spring is limited by the engagement of a stop face I08 on the lever with a stop I I0 on the frame of the type carriage. The key lever I02 carries at its forward end a pin I I2 arranged to engage in a slot I I4 in a pivoted spring actuated latch H6, when the key is depressed, to hold the same in position.

With the above construction, upon the depression of the key lever I02, the lever 92 is swung in a counterclockwise direction, Figure 1, about shaft 94 thereby swinging the lever 82 in a corresponding direction to depress the shifter 10 and thereby locate the pin 60 in the lower portion of the slot 58. This positioning of the pin will cause the rearward movement of the ribbon vibrator produced by the action of a type bar mechanism to be increased to locate the ribbon in position for printing upon the forward strip D thereof.

The depression of the key I02 also shifts the 1 stop member. 82 from the position shown in Figure 3 to the position shown in Figure 4 to locate the stop in position to be engaged by the pin 28. To this end the lever 92 is formed with an arm I I8 which is connected by a link I20 with an arm I22 formed upon the upper end of the rod or shaft 34. Thus when the lever 92 is swung in a counterclockwisedirection, the shaft 34 is turned in a clockwise direction, Figures 3 and 4, tolocate the stop member 32 in the position shown in Figure 4.

The mechanism for oscillating the arm 66 to reciprocate the ribbon vibrator comprises spaced arms I24 attached to the rock shaft 88, from which is suspended upon hangers I26, the universal bar I28. The universal bar is arranged to be engaged by an abutment screw I29 mounted on each type bar actuating lever I30 and is depressed to move the ribbon vibrator rearwardly to locate the ribbon in typing position upon the depression of each lever I30. The levers I30 are pivoted in. parallel relation on the shaft I04 and may consist of key levers such as shown in Patent No. 1,251,361 or intermediate levers such as shown in Patent No. 2,370,505.

It is to be understood that the invention is not limited to the particular construction and arrangement of parts of the illustrated embodiment of the invention but that the invention may be embodied in other forms within the scope of the claims.

Having explained the nature and object of the invention and having specifically described a construction embodying the invention in its pre-- ferred form, What is claimed is:

1. In a typewriting machine, a horizontally movable ribbon guide and means for moving the guide rearwardly and forwardly, respectively, into and out of operating position comprising a lever pivoted on a substantially horizontal axis and extending below said axis to the rear of the guide, means for swinging said lever, a lever pivotally supported on the lower portion of said first lever to swing forwardly and rearwardly therewith and also to swing independently of said first lever on a substantially horizontal axis, a stop for limiting the movement of said second lever with relation to said first lever during the movement of said first lever to move the guide forwardly, a spring connecting said first lever with said second lever to maintain the latter in engagement with said stop during the greater part of the movement of said first lever to move the guide rearwardly and arranged to yield upon the arrest of the latter movement of the guide, stops shiftable alternatively into operating positions for limiting the movement of the guide rearwardly into operating position and means for shifting the stops.

2. In a typewriting machine, a horizontally movable ribbon guide and means for moving the guide rearwardly and forwardly, respectively, into and out of operating position comprising a lever pivoted to swing on a substantially vertical axis, a second lever pivoted to swing on a substantially horizontal axis located to the rear of the guide, means for swinging said second lever, a third lever pivotally supported on the second lever to swing forwardly and rearwardly with the movement of the second lever to move the ribbon guide into and out of operating position and also to swing independently of said second lever on a substantially horizontal axis, a stop carried by the second lever and arranged to be engaged by the third lever to limit the pivotal movement of the latter with relation to the second lever dur- .ing' the movement offthe second leverrjto move theribbon guide forwardly, a spring for maintaining. the third lever in engagement with the stop during the greater part. of the movement of the second lever to move the ribbon guide rear- Wa-rdly and arranged to yield upon the arrest of the latter movement of the guide, a. link connecting the first lever and the third lever,'a horizontally movable stop member for limiting the movement of the first lever and thereby the movement of the guide into operating position, two stops carried by said stopmember and means for adjusting said stop member to locate said stops alternatively in operating positions.

' ELMER L. WISE.

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

UNITED STATES PATENTS

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