US2070026A - Typewriting machine - Google Patents

Description

Feb. 9, 1937. H. L. PITMAN 25 TYPEWRITING MACHINE Original Filed Sept. 21, 1933 INVENTOR ATTOZEY Feb. 9, 1937. H. L. PITMAN 'IYPEWRITING MACHINE Original Filed Sept. 21, 1955 2 Sheets-Sheet 2 R O T N E V m ATTOR Patented Feb. 9, 1937 UNITED STATES PATENT or ies TYPEWRITING MACHINE Original application September 21-, 1933, Serial N 0. 690,301. Divided and this application September 30, 1935, Serial No. 42,808

6 Claims.

This invention relates to universal-bar mechanism for the ribbon-vibrator and escapement of typewriting machines, and one of its aims is to eliminate the liability of overthrowing or crumpling the vibrating ribbon.

It is usual for a common universal-bar stroke to effect simultaneously the escapement-operation and full amplitude of ribbon-vibration, the Stroke having the high speed or staccato characteristic due the desirability of working the escapement quickly. Because the ribbon is vibrated very fast, it is liable to overthrow, which causes bleeding in a two-color ribbon. It is further liable to crumpling, which, at high speed, is due to inertia of the ribbon relatively to the rapidly starting ribbop-vibrator.

It remains desirable to localize the universalbar mechanism at the region of the machine where it can be operated by a type-carrier which, swinging in the usual Wide arc, is the member best capable, by reason of its momentum at the end-portion of its swing followed by immediate recoil, of imparting the desired staccato impulse to the universal bar.

In the standard Underwood typing machine, for example, each of the arcuately-arrayed swinging type-bars has near its fulcrum a heel to actuate a single curved universal bar common 3 to the escapement and ribbon-vibratingdevices,

and which universal bar, in order to secure its staccato actuation, is only engaged by said heel at the final portion of the printing stroke. It Will be evident that when such common universal bar 35 and cooperating heel are used, the limit to which the speed of ribbon-vibration can be forced, limitedly determines the speed of the universal bar and hence, largely, the speed of the carriageeed.

In practicing the present invention, a univere sal-bar-actuating portion of the type-bar or other similarly moving type-action member is arranged relatively to a novel localized universalbar mechanism in such a way that the ribbonmovement to the printing point does not wait for the carriage-escapement operation, but starts substantially as soon as the type-bar leaves its normal position, and may continue substantially throughout the printing stroke. The movement of the ribbon to the printing point is thus protracted, and it may be effected with smooth acceleration. Thus there is eliminated the liability of either overthrowing or crumpling the ribbon. Said universal-bar-actuating portion of the typeaction member is further arranged relatively to the novel localized universal-bar mechanism, so that the escapement-actuating phase in the operation of said mechanism has the desired staccato characteristic, whereby the escapement is actuated in immediate correlation to, that is, very close to, the instant of type-impact, and it is feasible therefore to use a speed escapement with consequent benefit to the key-touch.

To these ends, the universal bar is preferably made in two parts, which parts present two universal'faces or edges which may be disposed next to one another in accordancewith the idea of localizing the universal-bar mechanism. One of the parts has its universal face or edge engaged preferably bya cam on the swinging typebar or similarly moving type-action member, and operative to impart the relatively slow movement to said ribbon-vibrating universal-bar part. The other universal-bar part. is. engaged by a formation on the type-action member, so disposed that it comes into play very close to the instant of type-impact, so that the desired quick operation of the carriage-escapement is effected.

In the Underwood type of machine, the twouniversal faces or edges may be arcuate to conform with the arcuate array of the type-bars, each of the latter being provided with said ribhon-vibrating cam and said escapement-actuating formation. Said arcuate universal-bar parts may be one above the other.

The arrangement may be such that the connections to operate the carriage-escapement and ribbon-vibrator may remain practically unaltered in respect to the connections used in prior machines, and the novel universal-bar mechanism may therefore be applied to existing types of machines at little expense.

The invention may be used in the form of a single universai bar having a universal face or edge formation, which is engageable, during the printing stroke, first by the protractedly-operating ribbon-vibrating cam of the type-action member, and then by a part on said type-action member, which part overhauls the single universal bar and gives the same a staccato impulse very close to the instant of type-impact, and, at the beginning of which impulse, said universal bar has reached the end of approach to, and has thereby become engaged with, a carriage-escapement-operating member.

This application is a division of my application Serial No. 690,301, filed September 21, 1933" (now patent No. 2,023,487, dated December 10, 1935).

Other features and advantages will hereinafter appear.

In the accompanying drawings,

Figure 1 is a perspective view showing the invention as applied to a single universal bar.

Figure 2 is a side elevation view showing the single universal bar and its relation to the novel type-bar heel and to the ribbon-vibrating and escapement-operating connections. Figure 3 is a front elevation view of parts of the organization seen in Figure 2, some of said parts being sectioned and broken away for clearness.

Figure 4 is a side elevation of the universalbar train and connections of Figure 2, and shows the positions of the parts at the instant of typeimpact.

Figure 5 is a fragmentary side view indicating how the type-bar heel-cam may effect the ribhon-vibrating phase of universal-bar movement, and also indicating, in the use of asingle universal bar, how the escapement-actuating portion of said heel has overhauled the coacting edge of the single universal bar.

Depression of any alphabet or numeral typekey I0 on key-lever I I, Figure 2, swings, by means of suitable connections, a type-bar I3, pivoted at I4, to print against aplaten I5. Said connections may include a bell-crank I'I articulated to the 1 key-lever II by a pin-and-slot connection I9 and to the type-bar I3 by a link 20, as examplified in Patent No. 644,082, to Kauffman, of February 27, 1900.

A segment ZI on machine-frame 22 pivotally mounts the system of type-bars I3 in the usual arcuate array seen in Figure 3.

An Underwood platen-carriage is represented in Figure 2 by a case-shiftable frame 24 forming part of said carriage which has a letter-feeding rack 25 and is driven by the usual spring-motor (not shown) in a letter-feeding step at operation of a type-bar I3.

The novel ribbon and escapement actuating universal-bar mechanism will now be described with reference to its application in the illustrated machine. It may be noted beforehand that the escapement-mechanism includes the usual escapement-wheel 28 co-operative with the usual dog-rocker 29 having dogs 3| and 32, said escapement-wheel having a pinion 33 meshing with the carriage-rack 25.

For the purpose of vibrating the ribbon at relatively slow speed and the escapement at high speed by means of a localized universal-bar mechanism, the invention may be practiced by' means of a substantially one-piece or unitary universal bar or frame, which, to this end, may bearranged relatively to the type-bar I3, as shown in Figures 1 to 5. V

The heel-portion of each type-bar I3 is accordingly made substantially the same as hereinbefore described, to include a ribbon-vibrating camming edge 62 and an escapement-actuating 'The edge or face I03; associated with operation of the ribbon-vibrator, may be formed by a flange I00 of an arcuate bar I01. A similar bar I08 presents the edge I05 which is associated with operation of the escapement.

Said bars I01, I08 and a member III are fastened together by rivets I I0 to form the universalbar frame I 04 which has side arms I I3 connected to the rockable frame 46 to support the rear of the frame I04 for fore-and-aft movement. The forward part of said frame I 04 is supported for fore-and-aft movement by means of a tongue I I 4, slidably fitting in segment 2| A spring I I6 urges the universal-bar frame I04 forwardly, the forward movement of said frame being limited, as in Figure 2, by abutment of the face I03 thereof with the camming edge 62 of the type-bar.

The universal-bar-frame member II I also has an upstanding flange II! to carry the laterallyshiftable bracket 73 of the usual Underwood ribboil-vibrating train.

In the swing of the type-bar I3 from the Figure 2 position to the Figure 5 position, and beginning with the start of said swing, the camming edge 62* of said type-bar moves the universalbar frame I04 rearwardly with smooth acceleration indicated by the dotted lines I I8, Figure 5 representing the positions of the frame I94 at equally spaced stages in the swing of the type-bar. Hence the cam-edge 63* here, too, co-operates to raise the ribbon without liability of overthrowing or crumpling the same. As indicated in Figure 2, an escapement-actuating rear edge i I 9 of the frame I04, opposite the dog-rocker 29, is normally spaced forwardly of said dog-rocker, so that the latter is not moved until the type-bar reaches the Figure 5 position. The escapement-dog rocker 29 is therefore operated quickly, that is, in the relatively brief interval during which the type-bar I3 moves between the Figure 5 and the Figure 4 positions. This quick movement of the universalbar frame I04 is effected by means of said edge during said interval. Although the ribbon still has a residue of its movement to the printing point to be completed during said interval, the liability of overthrow or crumpling of the 'ribbon is, nevertheless, practically eliminated since said residue of movement is small, and hence the speed of the ribbon during said interval is very much less than where, as heretofore, the full amplitude of ribbon-vibration took place during said interval. Conversely, during the recoil stroke of the type-bar from the Figure 4 po sition, the universal-bar frame I04 at first moves quickly forward under the pull of spring II6 as the type-bar moves from the Figure 4 to the Figure 5 position, and, in this part of the typebar recoil stroke, the dog-rocker 29 quickly completes its reciprocatory movement. As the typebar further returns, from the Figure 5 position to the Figure 2 position, the universal-bar frame I04, still moving forward under the pull of spring H5, follows the camming edge 62 so that the return of the ribbon from the printing point is effected at relatively slow speed.

U. S. Patent 926,050, to F. A. Cook, exemplifies the Underwood ribbon-vibrator connections in which platen case-shift rail 64 mounts a lever having an arm 68, carrying the ribbon-vibrator 35, and an arm 10 presenting pins'II selectively engageable by laterally shiftable bracket I3 (Figure 3) on the universal bar frame flange H1. The bracket I3 in the dotted-outline position 13 Figure 3, engages the upper pin H and hence rearward movement of the universal bar frame I04 will raise the ribbon-vibrator 36 only far enough to make the upper band of a two-color ribbon 21 effective. With the bracket 73 in the full-line position of Figure 3 to engage the lower pin "H, the rearward movement of the universal bar frame I04 brings the lower ribbon band to the printing point, Figure 4. The usual linkage for shifting bracket 13 is represented at 18.

It will be seen that the novel universal-bar mechanism is localized so that it occupies very little more room than was heretofore occupied by the single Underwood universal bar; and it will be further seen that the connections from said mechanism to the ribbon-vibrator 36 and the escapement-dog rocker 29 may be arranged as in prior machines, and that the invention may therefore be applied at little expense.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a typewriting machine, a system of members of individually-operable type-actions, and a universal-bar device for actuating the ribbon-vibrator and carriage-escapement of said machine, each member having means for actuating the ribbon-vibrator at relatively slow speed by Working said universal-bar device through a protracted period of the type-action stroke, each member also having a shoulder coming into play to actuate said universal-bar device to work the escapement quickly in correlation to the instant of typeimpact, said universal-bar device being arranged so that the points at which it is engaged by each of said means and corresponding shoulder are juxtaposed, next to one another, to localize said points and thereby compact said device.

2. In a typewriting machine, a system of members of individually-operable type-actions, and a universal-bar device for actuating the ribbonvibrator and carriage-escapement of said. machine, each member having a cam for actuating the ribbon-vibrator at relatively slow speed by working said universal-bar device through a protracted period of the type-action stroke, each member also having a shoulder coming into play to actuate said universal-bar device to work the escapement quickly in correlation to the instant of type-impact, said universal-bar device having two faces, one face for engagement by said cam, and the other face for engagement by said shoulder, said faces being juxtaposed, next to one another, to localize the same and thereby compact said device.

3. In a typewriting machine having a ribbonvibrator and an escapement-mechanism, a system of type-carriers mounted to swing individually to bring their types to a common printing point, and a universal-bar device operable to actuate the ribbon-vibrator and escapement, each type-carrier having at its fulcrum-end a cam to operate said universal-bar device through a protracted period of the type-carrier stroke, each type-carrier also having near its fulcrum-end a shoulder coming into play to actuate said universal-bar device to work the escapement quickly in correlation to the instant of type-impact, said universalbar device having means engageable by the cams and shoulders, and localized in operative contiguity thereto.

4. In a typewriting machine having a ribbonvibrator and an escapement-mechanism, a system of type-carriers mounted in arcuate array to swing their types to a common printing point, each type-carrier having at its fulcrum-end a cam, and also having a shoulder in sequence to the cam-contour, and a universal-bar structure operable to actuate the ribbon-vibrator and the escapement, said structure presenting a curved universal-bar portion for engagement by said cams and shoulders, the cam actuating the rib hon-vibrator at relatively slow speed by engaging said curved portion during a protracted period of the printing stroke, and the shoulder thereupon coming into play with said curved portion to work the escapement quickly in correlation to the instant of type-impact.

5. In a typewriting machine, a system of typeaction members swingable to bring types to and from the printing point, each of said type-action members having coaxial with its fulcrum a twopart cam, a universal bar displaceable by the rotation of any cam, and a letter-feeding escapement and a ribbon-vibrator operable by said universal bar, said cam and universal bar being relatively constructed so that the universal bar stroke is smoothly accelerated, by one part of the cam, from the beginning of and during a major portion of the printing stroke of the type-action member, and is then abruptly stepped up in speed, by another part of the cam, relatively to completion of the type-action member printing stroke, for eifecting, respectively, overthrow-preventing protraction of the ribbon-vibrator operation, and staccato high-speed operation of the letterfeed escapement.

6. In a typewriting machine, a system of typeactions printing individually at a common printing point, a universal bar, a ribbon-vibrator and an escapement mechanism operable by said universal bar, each type-action having two-part universal-bar-actuating means, one part serving for smoothly accelerating the universal bar stroke from the beginning of and during a major .portion of the printing stroke of the type-action, the other part then coming into play to abruptly impel the universal bar to a substantially higher speed during the remainder of the printing stroke, whereby, respectively, overthrow-preventing protraction of the ribbon-vibrator operation and staccato high-speed operation of the letter-feed escapement are effected by means of said universal bar.

HENRY L. PITMAN.

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