US1505093A - Ribbon mechanism for typewriters - Google Patents

Description

Aug. 19. 1924.

. DE WITT C. HARRIS RIBBON MECHANISM FOR TYPEWRITERS Find nay' s, 192:.

3 Sheets-Sheet 2 Aug.' 179, 1924;- 1,505,6193

Y l I DE WITT C. HARRIS RIBBON Mvcmmrsm Fon TYPEwRITERs File nay :5,1922 s sheets-sneer 3 fag, lr6

` dotted line 4 of Fig. l.

Patented Aug. 1 9, 1924,

DE WITT C. HARRIS, 0F PINELAND, FLORIDA.

RIBBON MEHANISM FR T'YIEEWRITERS.

Application filed May 3,

To all whom. 'it may concern Be it known that I, Dn `Wrr'r C. Ilanms, a citizenof the United States, residing at Pineland, in the county of Lee and @tate of Florica, have invented a certain new and useful Ribbon Mechanism for Typewriters, of which the following is a specification.

This invention relates particularly to improved means for vibrating the ribbon, for shifting from one color or field to the other, and for silencing the vibratorwhen it is desired to make imprints without using the ribbon, as when cutting stencils.

In the accompanying drawings, Figure l is a fragnrental longitudinal vertical central sectional view of one form of typewriter embodying the features of my invention. Fig. 2 is adetail View of the type guide and the ribbon guide. flfig. 3 is a horizontal sectional view showing a portion ofthe ribbon-vibrating mechanism, and vibrator-controlling mechanism in plan view. Fig. a is afragmental vi-ew of the vibrator-controlling mechanism, as viewed from the rear, that is to say, in the plane indicated by Fig. 5 is a Vview on an enlarged scale of certain of the parts shown in Fig. l. Fig. G is a view taken approximately in the plane of dotted line 6 6 of Fig. 5.

lVhiie the present invention in its broader aspects is applicable to typewriters of various classes, it is herein shown as embodied in a front-strike typewriter of the construction fully disclosed in `my copending appli- I cation Serial No. 541,930 tiled M'arclrS, 1922,

In this application I have described and claimed a complete typewriter which comprises a plurality of independent or selfcontained sections or units so constructed and related that they may be separately manufactured and assembled as units and then may be quickly associated together to form a complete machine, the said units being also readily demountable lor separable from each other to facilitate cleaning, adjustment or repair and to permit of the replacement cf a vworn unit by a new unit when necessary.

For the sake of lucidity I will herein describe briefly the general construction of this type of machine without, however, intending to limit the invention to such type; Referring to Fig. ,1 of thedrawings, the machine comprises an external lsection composed of a framework A which carries ceri922. Serial No. 558,077.

- This will be herein referred to as the frame unit. The machine also comprises an internal section hereinafter termed the action unit, which includes a frame or support B and operating mechanism thereon, said unit as a who-le being insert'able into the frame unit through the lower end of the latter, the two units being provided with complementary locking devices (not herein shown) which are arranged to be instantly operable by the operator-s fingers to lock the two units together or unlock them to permit of their separation.

This action unit comprises in the present :instance a vertically shiftable type bar segment C on which are pivoted the set of type bars, one being herein shown at D. E designates the type guidel which is fixed to and extends upwardly from the segment tl. @ne of the series of key levers is shown at F, said lever being pivoted upon a rod or devices II to the type bar. The action unit frame is provided with the usual feet I to rest upon al desk or other suitable support, and the frame unit rests upon and is supported by the action unit frame. In separating the two units the frame unit is lifted bodily in a vertical direction off the action unit without disturbing the latter. The operating mechanism on the respective units comprises parts which are arranged to assume an operative relationship to each other automatically in the act of assembling the two units. 4

In the machine disclosed in my said companion application there is a third demountable unit which Vcomprises the carriage. I have deemed `it unnecessary to show this unit in this application, the platen only being diagi'ammatically shown at K.

Referring now to thek ribbon mechanism which is the subject .matter of the present application, the ribbon itself is indicated by reference nume al l, one ofthe pair of spools on which it is wound being designated 2. This spool is mounted upon the upper end of a vertical shaft 3 suitably supported in a bearing in the frame unit, said shaft and the spool thereon being driven by suitable means herein shown as comprising a horizontally extending shaft 4; and a pair of intermeshing spiral gears 5 xed lon the shafts 3 and 4; respectively. That portion of the ribbon which is in proximity to shaft G andbeing connected by suitable the platen is carried in two guides 7 arranged at opposite sides of the printing point, said guides being secured to a vibrator stein 8 which is mounted on the type guide E for vertical reciprocation. The lower end of the stem S is pivotally connected at 9 (Fig. 5) t0 the forward end of an arm 10 which is integral with or otherwise attached to a cam structure 11. The latter' is pivoted at 12 to a bracket 13 fixed to the frame' B of the action unit. The cam structure 11 contains two cam slots of different forms, one being adapted to provide sufficient movement to aise the ribbon guides 7 from their normal position to a position where the upper field of the ribbon may be struck by the type, and the other cam beingof such form as to provide sufficiently greater movement to bring the lower field of the ribbon into printing position. In the present embodiment, the cam structure 11 consists of a piece of sheet metal vfolded to form two spaced parallel sides and a rear connecting web 14. In one side of the cam structure is formed a cam slot 15, and in the other side there is a cam slot 1G.

Means in the nature of a pivoted arm is provided to engage the cam structure 11, said arm being laterally shiftable to engage either cam slot or to lie in an ineffective position between the sides of the cam structure. IVhile power to swing the abovementioned arm may be obtained from any suitable source, it is herein shown as actuated by means including a universal bar 17 connected at its ends to arms 18 which are pivoted upon the pivot G for the key levers "F. The key levers F have downwardly extending arms 19 with which the universal bar 17 normally is in contact. At the middle of the universal bar 17 is a rearwardlyextending projection 20 arranged to engage aA` short arm or lug 21 attached to a rock shaft 22. The shaft- 22 extends transversely of the machine from the right hand side thereof, t0 a point about midway of the sides the machine. Fixed to the inner end of the shaft 22 is a rearwardly-extending arm 23. On opposite sides of the free end of said arm are rollers 24- adapted to lie in the cam slots 15 and 1G. Said cam slots are of suoh form that when the ribbon -vibrator is'in its position of rest, the lower said sides and out of engagement with both cam slots. A coiled contractile spring 25 connected at` one end to the pivot 12 and at its other end to a lug 26 rigid with the shaft 22, normally holds the arm 23 in its lower-most position.

The means for longitudinally shifting the shaft 22 to place the rollers 24; in eugagemeut with the desired cani slot or in central neutral position nray partake of various forms. That herein shown comprises a lever 27 pivoted to the frame B of' the aetion unit to swing upon the vertical axis 2S (Figs. 1 and 3). The rearwardly extending arm of the lever 27 has a bent end which embraces the shaft 22 and lies between shoulders 29 (Fig. G) on said shaft. To the forwardly-extending arm of the lever 27 is pivoted a link 3() (Figs. 3 and 4) which extends to the longitudinal median plane of the machine and is there pivoted at 31 to the downwardly-extending arm of a three-arm levcr 32. Said three-arm lever is mounted to swing upon a horizontal axis 33 and comprises two oppositely-extending arms Set which extend freely through openings in the lower portions of two vertical parallel plungers 35. These plungers are guided in the frame B for vertical movement. In an overlying portion of the frame A are mounted two plungers 36 and 37 having at their lower ends heads 38 which engage the upper ends of the plungers 35. The upper ends of the plungers 3G and 37 constitute linger keys adapted for depression by the operator. It will be seen that when the plunger 3G is depressed, the three-arm lever 32 will be swung in the direction to push the shaft 22 into position to place the arm 23 in engagement with the cam slot 15, this cam slot being of such form that the oscillation of the arm 23 will cause only suilicient movement of the ribbon guides 7 to lace the upper field (for example, the black eld) in printing position. When the plunger 37 is depressed, the shaft 22 will be slid 1n the opposite direction to place the arm 23 in engagement with the cam slot 16, whereby swinging movement 0f the arm 23 will cause an increased range of movement of the ribbon guides 7, such movement being sullieient to place the lower or red field of the ribbon at the printing line.

If the operator depresscs the plungers 36 and 37 to an equal extent, the arm 23 will be caused to occupy a central position midway between the slotted sides of the cam structure 11, thus disconnecting the ealn structure 11 from the arm 23 and permitting operation of the machine with the ribbon at rest in its lower or ineffective position. This is the condition desired when work such as stencil cutting is to be done.

Means is provided for yieldingly holding the shaft 22 in any one of its three positions of adjustment. While any suitable means may be employed for this purpose, I have herein shown two locking balls 40 lying in openings in the upper and lower sides of a stationary supporting structure 41, these balls being adapted to engage in peripheral grooves 42 formed in the shaft 22. Leafl springs 43 serve to press the balls 4() yieldingly against opposite sides of the shaft 22.

Referring again to the demountable type of machine in which the invention is herein shown as embodied, it will be seen from Fig. l that the ribbon and its driving mechanism, that is, the mechanism for rotating the ribbon spools 2, are mounted upon the frame unit A and that the plungers 36 and 37 are also mounted upon this unit. The ribbonvibrating mechanism including' the means for shifting colors and for silencing the ribbon guide is mounted on the action unit B. Then the two units are to be separated the ribbon l is withdrawn from the guides 7 and the frame unit may then be lifted bodily off from the action unit, leaving the latter standing upon the desk or other support. In reassembling the two units the plungers 36 and 37 automatically assume their operative relation to the plungers 35. The ribbon-driving mechanism and the ribbon-vibrating and color-shift mechanism are so mounted and located upon the respective units A and B that they do not interfere with the separation and assembly of the two units.

I claim as my invention:

l. A typewriter having, in combination, ribbon-vibrating mechanism including a rock shaft extending transversely of the typewriter, a lever pivoted between its ends at one side of the typewriter, the rear arm of said lever being connected to said shaft, an operating element located in the longitudinal median plane of the typewriter, a connection between said element and the forward arm of said lever, and two finger keys arranged to move said element in opposite directions.

2. A typewriter having, in combination, a ribbon carrier, two cams rigidly secured together and connected to said carrier, a rock shaft, an arm on the shaft adapted to engage either of the cams or to lie in the space between the cams, a `key-lever universal bar arranged to move the shaft around its axis, and key-operated means for longitudinally moving the shaft.

3. A typewriter having, in combination, a frame unit and an action unit arranged to be readily separated and assembled, ribbondriving and supporting mechanism mounted on the frame unit and ribbon-vibrating mechanism mounted on the action unit.

4. A typewriter having, in combination, a frame unit and an action unit arranged to be readily separated and assembled, ribbonsupporting and driving means mounted on the frame unit, ribbon-vibrating and colorshift means mounted on the action unit, and means mounted on the frame unit for operating the ribbon color-shift means.

5. A typewriter having, in combination, a ribbon carrier, two spaced cams connected by an integral web, a rock shaft, an arm rigidly secured to said yrock shaft and adapted to engage either of said cams or to lie in the space between them, means for rotating said shaft to actuate said cams, and means for longitudinally moving said shaft to selectively position said arm with relation to said cams.

In testimony whereof, I have hereunto affixed my signature.

DE WITT C. HARRIS.

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