US2256256A

US2256256A - Ribbon actuating mechanism

Info

Publication number: US2256256A
Application number: US373510A
Authority: US
Inventors: Dieck Walter
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-12-28
Filing date: 1941-01-07
Publication date: 1941-09-16
Anticipated expiration: 1958-09-16

Description

.Sept. 16, 1941.

w. DIECK RIBBON ACTUATING MECHANISM Filed Jan. 7, 1941 Mf QW WWW! Patented Sept. 16, 1941 RIBBON ACTUATING MECHANISM Walter Dieck, Erfurt-Hochheim, Germany Application January '1, 1941, Serial No. 373,510 In Germany December 28, 1939 Claims.

The invention relates to typewriters and similar recording machines-and particularly to mechanism for actuating the ink ribbon vibrator thereof.

More particularly, the invention relates to improvements in ribbon vibrating mechanism in which the individual key levers or type levers of the type action cooperate with a universal bar which through suitable connections lifts the ribbon vibrator to shift the ribbon into printing position beneath the type bars when the machine is operated to cause one of the type-bars to move to printing position against the platen.

It is known to provide mechanism for lifting the ink ribbon vibrator uniformly during the duration of and coincidentally with the entire stroke of the type bars so that-both the type head and ink ribbon assume the final printing position substantially simultaneously. For accurate and neat work, it is desirable to bring the ribbon vibrator into printing position in advance of the completion of the printing stroke of the type bars so that the ribbon is at rest in the printing position at the time the type head impinges on the same to effect printing. However, the provision for movement of the ribbon vibrator to final position in advance of the type bars results in the vibrator engaging its limiting stop before the end of the stroke of the type bar and universal rail actuated thereby so that unless some special construction is provided the free motion of the type bars and universal bar will be interfered with. While this difficulty might be met by the introduction of spring connections permitting further motion of the universal bar after stopping of the ribbon vibrator, the use of spring connections is not practical if the ribbon vibrator is to be actuated with exactness and further the additional force required for overcoming the tension of the spring is objectionable.

It is the primary object of the invention to provide improved means for transmitting motion from the universal bar to the actuating connections for the ribbon vibrator which will effect accelerated lifting of the ribbon vibrator to printing position in advance of completion of the stroke of the type bars and provide for unhindered completion of the stroke of the type bars and motion of the universal bar after the ribbon vibrator has reached and while it remains at rest in the upper or printing position.

According to a preferred embodiment of the invention, the drawbacks discussed above and the objects of the invention are achieved by the provision of an adjustable cam connection between the universal bar and the lever system actuating the ribbon vibrator, the cam connection being shaped to provide for rapid movement of the ribbon vibrator to printing position upon initial movement of the universal bar by the type action and permitting free over-running movement of the universal bar and type bars with respect to the ribbon vibrator during the latter part of the printing stroke after the ribbon vibrator reaches and remains at rest in the upper or printing position.

The objects and advantages of the invention will be better understood by reference to the accompanying drawing, in which a preferred embodiment thereof is shown by way of example, and in which:

- Fig. 1 is a fragmentary sectional view through a typewriter embodying the invention, showing the parts in a position of rest, and

Fig. 2 is a similar view showing the disposition of the parts as the type bar approaches final printing position.

Referring more particularly to the drawing, wherein only so much of the typewriter mechanism has been shown as is necessary to an understanding of the invention, the type action comprises a key lever I, an intermediate rocking lever 2 and a type lever 3. The key lever is connected by a link 4 to one end of the intermediate lever 2 and a pull rod 5 connects the other end of the lever 2 to the heel of the type lever 3 which is pivotally mounted on the type segment 6. k

The segment 6 which mounts the type levers is formed to provide a guide and mounting for the ribbon vibrator I which carries the ribbon 8. These parts are'usual on typewriters and their construction and mode of operation are well understood, depression of the key lever I, through link 4, lever 2 and rod 5, throws the type lever from the at-rest position of Fig. 1 through the position shown in Fig. 2 to cause the type head to strike the platen 9, the ribbon vibrator being meanwhile raised to printing position so that the ribbon carried thereby is shifted into a position between the type head and the platen.

For th sake of simplicity, the color zone solecting means, usually associated with the ribbon mechanism has been omitted.

The lever system for actuating the ribbon vibrator I comprises a lever I0, pivotallly connected at one end to the vibrator l, as indicated at la. The lever III is mounted intermediate its ends on a stationary bearing pivot H and has its other .end pivotally connected with the end of one arm of a bell-crank lever I2 which latter is mounted on stationary pivot bearing I3. The connection between the lever I and bell crank I2 may be formed by engaging the hooked end of the arm through an aperture in the end, of the lever. A spring I2a connected between the, arm of the bell crank and a stationary part of a the frame urges the arm to the retracted position shown in Fig. 1.

A universal bar Ila is operated by a part of each type action. The bar extends transversely of the machine beneath the key levers in position to be engaged and depressed by the same upon the depression of any one of the keys.

The universal bar Ila has rearwardly extending side arms I4 ,at each end thereof by which it is journalled on horizontal pivot bolts I5 mounted on side frame members, not shown.,

roller I6 journalled on a horizontal pivot pin Ilia i disposed substantially perpendicularly above the 3 pivot bolt I5.

A lever arm I8, pivoted at one end on the rod Return springs I'I connected between i movement thereof, thus allowing completion of the stroke of the key lever and over travel of the universal bar after the ribbon vibrator has been shifted to its uppermost position.

By adjustment of the vertical position of the finger 2n and the angularity thereof with respect to the path of the roller I6, the extentand speed of movement of the ribbon vibrator with respect to the motion of the type action can be varied as desired.

While a preferred embodiment of the invention has been shown and described by way of illustration, it will he understood that various modifications in the details of construction and oper- 125 arms I'lb carries a projection in the form of a- I9 mounting the key levers I, extends forwardly thereof and at its forward end isprovided with 1 a sutstantially vertically extending terminal portion upon which is mounted a cam element in 1 1 the form of a forwardly extending curved finger member 20. The finger member 20 is carried by 1 a plate 20a which is secured on the end of arm It by screws 2I, the plate being slotted at 2Ia so that the position of the same may be adjusted. 1 The cam finger;20 engages under and extends The slots 2Ia in the 3 plate 20a extend vertically so as to permit verti- 1 cal adjustment of the plate and the upper slot is made considerably wider than the diameter of 1 up in front of the roller I6 carried by the lever 5 Ilb of universal bar Ila.

1 the shank of the screw 2I engaged therethrough 1 so that the inclined position as well as the verti- 1 cal position of the curved cam finger 20 may be adjusted in relation to the roller I6. 1 A horizontal pin I8a carried by the lever arm I8, forwardly of the pivot rod I8, engages the i 1 lower arm I2b of the bell crank lever I2 when the lever I8 is depressed, thus rocking the bell 5 crank and through the lever I0 raising the ribbon vibrator.

Thereturn spring I2a acting on bell crank I2 yieldingly holds the lever I8 in raised position with the cam finger 20 in engagement with roller I6.

The roller engaging surface of the curved cam 1 finger 20 is formed with a contour to eifect the desired movement of the ribbon vibrator in relaj tion to the stroke of the type lever. With the parts at least, as shown in Fig. 1, the roller I6 1 contacts a part 22 of the surfaceof the finger which extends substantially coincident with the ipath of the roller upon depression of the unif versal bar. The surface part 22 merges into the j cam surface 23 disposed in the path of the roller 1 I6 at a sharp angle to said path so that the lever iis rapidly depressed whenthe roller I6 moves from the position of Fig. 1, to the position of 2. The cam surface 23 merges into a final jend surface 24, which, in the depressed position ;of Fig. 2, extends substantially coincident with jthe path of travel of the roller I6 upon continued ation of the parts may be resorted to without departing from the spirit of the invention within the scope of the appended claims.

I claim:

1. In a typewriter, a platen, a type action including a type bar movable to and from printing engagement with the platen, a ribbon vibrator movable to and from the printing point on the platen, a universal bar operatively engaged by a part of the type action, a projection carried by said universal bar, an actuating linkage for said ribbon vibrator including a lever, a finger carried by said lever having a cam surface portion disposed in the path of said projection and so shaped that, upon actuation of said universal bar by said type action, said projection moves over a portion of said cam surface and actuates said lever to move said ribbon vibrator to the printing point before the type bar reaches the platen and then moves over a succeeding portion of said cam surface to maintain said ribbon vibrator at the printing point during final movement of the type bar into printing engagement with the platen.

2. In a typewriter according to claim 1, means for adjusting the position of said finger with respect to the projection carried by the universal bar.

3. In a typewriter, a platen, a type action including a type bar movable to and from printing engagement with the platen, a ribbon vibrator movable to and from the printing point on the platen, a universal bar pivoted on a horizontal axis and operatively engaged by a part of the type action, a roller carried by said universal bar spaced from the pivoted axis thereof, an actuating linkage for said ribbon vibrator including a lever, a projecting member carried by said lever having a cam surface disposed in the path of movement of said roller upon operation of said universal bar, said cam surface being so shaped that upon actuation of said type action and universal bar movement of said roller over a portion of said cam surface actuates said lever to move said ribbon vibrator to the printing point before the type bar reaches the platen and movement of said roller over a succeeding portion of said cam surface maintains said ribbon vibrator at the printing point during final movement of the type bar into printing engagement with the platen. Y

4. In a typewriter, a platen, a type action including a type bar movable to and from printing engagement with the platen and a key lever operatively connected with said type bar, a ribbon vibrator movable to and from the printing point on the platen, a universal bar pivoted on a horizontal axis and extending transversely beneath said key lever and operated thereby upon depression of the key lever to move said type-bar into printing engagement with the platen, an

upstanding lever arm carried by said universal bar, a laterally projecting roller carried by said lever arm, an operating linkage for said ribbon vibrator including a lever pivoted on a horizontal axis and extending from said axis to adjacent said lever arm, a plate mounted on said lever having a projecting flnger portion presenting a cam surface disposed in the path of movement of said roller, said cam surface including an active portion and a neutral portion so shaped that upon operation of said universal bar by depression of said key lever movement of said roller over the active portion of said cam surface actuates said lever and associated linkage to move the ribbon vibrator to the printing point before the type bar reaches said point and movement of said roller onto the neutral portion of the cam surface upon continued motion of the universal bar maintains the ribbon vibrator stationary at the printing point during final movement of the type bar into printing engagement with the platen.

5. In a typewriter according to claim 4, means for adjusting the position of said plate on said lever to vary the relation of said finger with said roller for regulating the amount and character of movement of said ribbon vibrator.

' WALTER DIECK.