US1474932A - Typewriting machine - Google Patents

Description

Nov. 20, E923. mms' .w. F. HELMOND TYPEWRITING MACHINE Filed March 8. 1922 Patented Nov. 2d, 1923.

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WILLIAM F. HELMOND, OF HARTFORD,

CONNECTICUT, ASSIGNOR T UNDERWOOD TYPEWRITER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

TYPEWRITIN G MACHINE.

Application filed March 8, 1922. Serial No. 31,908.

To all whom it may concern.

Be it known that I, VILLIAM F. HEL- MOND, a citizen of the United States, residing in Hartford, in the county of Hartford 5 and State of Connecticut, have invented certain new and useful Improvement in Typewriting Machines, of which the following is a specification.

in an Underwood typewriting machine,

1 the type-bar strikes a fixed abutment just as it reaches 'printingposition, the point of contact with the abutment being between the ends of the type-bar. The type-bar springs against the platen with sufiicient force to make the desired impression, but cannot strike a second time, or make a double impression. This construction usually conduces to clearness and sharpness of the im-- pression, and renders it permissible for the type-bars to be made of considerable length and very thin and light.

i In assembling the parts, it has been necessary to secure exactness of relationship between type-bars, the abutment or stop and the platen, it being usually necessary for the type to be within less than five-thousandths of an inch from the platen when arrested by the abutment, and it being also necessary to leave a space of some thousandths of an inch between the type and the platen, so as to avoid blurring or double printing. The permissible variation in the position of the type when arrested by the abutment has therefore been micro so scopic, and difficult to secure. If the typebar strikes the abutment a trifle too soon, it results that the type-bar springs excessively in reaching the platen, and the entreme tip of the type therefore makes too heavy an impression, compared with the main portion of the type. This ill efiect is produced when the type-bar is not more than ten or fifteen thousandths 01 an inch away from the laten at the time it strikes the abutment. he abutment is'rather near the type end'of the bar, causing the bar to spring or bend on a short radius, with the result that the top of the type prints so heavily. Theeiiect is the same as if the type were of? so its feet, and the trouble has to be corrected bending the type-bar with tools, or by fitting the type-bar more closely with relation to the abutment. This is a slow and expensive operation, every type-bar having to becarefully tested for exactness of relation with abutment and platen.

The lateral vibration of the type-bar is considerable, tending to impair the side alignment and the spacing of the type impressions. The capital letters particularly tend to incline to the right or left when the machine is re idly operated, the axis of the lateral vihi'atmn being at about the point where thetype-bar strikes the abutment, which, as already noted, is rather near the type, so that the angular extent of the lateral vibration is considerable.

In overcomin these dithculties, each type-bar is provided with a tongue or device projecting therefrom which strikes the abutment or stop just as the type almost reaches the platen. Said tongue is preferably resilient, and integral with the typebar. In using this improved bar, the types can be from .five thousandths to fitteen thousandths of an inch from the platen when the yielding ton ue or buffer contacts with the abutment. e improvement renders close work unnecessary, there being such a large margin that a high degree of skill is not required for adjustment, and. the machine can be manufactured more cheaply and rapidly.

After the abutment is struck, the irnproved bar can yield for a distance that is about equivalent to the entire length of the bar. Owing to this great springing or bending length, the type prints evenly. The difficulty of the top of the type printing the heaviest is overcome. The improved bar can be as far as fifteen thousandths of an inch away from the platen, when it arrested by the abutment, without printing heavily at the top of the type. This afi'ords considerable advantage in lowering the cost as and expediting the work of alignment, since a lower grade of aligning skill can be ergaged, microscopic closeness of relationship of the parts not being required, and it being therefore unnecessary to give the usual we close attention to testing the type-bars with relation to abutment and platen, substant ial range of variation being permissible.

A further advantage of the improved type-bar is that noise is reduced because the art that strikes the iised abutment is yieldin The yielding tongue is spring'y and back the type instantly from the platen, eliminating liability to blur. Moreover, since the type-bar starts back more promptly from printing position to its normal position, high speed of operation is favored.

Better carbon-copies are produced, because the type-bar is not stopped so sharply by the abutment, and does not have to bend or spring so much locally as heretofore. The invention has the effect of stopping the type-bar just the way it should be stopped.

In the new type-bar, the lateral vibration does not center at the point of contact with the abutment, asheretofore, but centers at a point close to the pivot of the type-bar, this beingrdue to the use of the spring tongue. he tremor takes place near the root of said tongue, and the lateral vibration of the types is reduced, because the tygpe-bar is very closely supported on both s1 es by the segment at about the axis of the lateral vibration. The ty )e impressions therefore have better side a ignment, and the impressions of the capital types also stand straighter, especially in rapid operation. The type impressions do not flare out to the right or left, and they stand inbetter vertical alignment. There is a sharper blow of the type on the paper.

Said spring tongues may lie exactly in the planes of their type-bars, or be edge to edge therewith, or they may be bent to either side or the other, so as to be out of the planes of their type-bars. In practice, the type ends of the bars are bent at different angles to the body-portions thereof, the bends or elbows being greatest at the sides of the typebar system. Consequently, side type-bar is at the printing point, the weight of the bar is at one side of a straight line joining the type-bar stop to the printing face of the type, where it touches the platen. Inasmuch as the type end of the bar moves at high speed against the platen, it results that the momentum of that por tion or elbow of the type-bar which is bent laterally from said straight line tends to spring said elbow, with the result of double printing or blurring of the type impression on the work-sheet. To said spring-tongue stop is bent laterally from the side of the type-bar opposite to that from which the type-block extends. At the left-hand side of the system. the type blocks are bent leftward from the type-bars, and the novel stop tongues are illustrated as bent out from the right-hand side of the type-bars. At the right-hand side of the system, the reverse is the case. From this it results that, as each type-bar approaches the platen, it is arrested by the spring tongue at a point somewhat to one side of the body of the bar; or at least the tongue itself is arrested while the body of the bar tends to continue towards the platen. The

when an extreme overcome this defect,

type impression therefore is produced by the springing of the type-bar beyond the point where the spring tongue is arrested. When the type is arrested by the platen, the momentum of the elbow-portion of the type bar causes it to tend to advance still farther; but inasmuch as the type-bar is now supported at the type and at. the pivot, it follows that such prolonged motion of the elbow-portion of the type-bar could only have the effect of twisting the bar; but this tendency to twist is intercepted by the spring tongue, which at this moment is under high tension, and which, by reason of its offset position, affords a support to the entire type-bar against twistin in this very direction. The result is that the entire momentum of the type-bar is utilized to make a strong, clear impression of the type on the work-sheet, and twisting of the bar minimized or eliminated. Viewed in another way, the type-bar, as soon as its spring tongue is arrested, tends to twist laterally away from said spring tongue; and thereafter when the type strikes, (and when, therefore, the spring tongue is under high tension) a tendency is set up for the type-bar to twist in the opposite direction from the first; and these two twisting tendencies counteract each other, while the spring tongue also opposes the final twisting tendency of the bar.

- Other features and advantages will hereinafter appear.

In the accompanying drawings,

Figure 1 is a plan of the type-bar portion of an Underwood front-strike typewriting machine; the spring tongues at the left-hand side of the system being bent to the right; and those at the right-hand side of the system being bent to the left, to varying degrees, depending upon the degree of bending of the type ends of the bars.

Figure 2 is a sectional side elevation, showing the type-bar in printing position.

Figure 3 is a front elevation of the typebar segment and platen, showing the graduated leftward bends of the spring-tongue stops of the type-bars at the right-hand side of the system.

The type-bars 1 are pivoted on a fulcrum-wire 2. and are operated by key-driven levers 3. The wire 2 is mounted in a seg ment 4, which has radial guide-slots 5 for the type-bars: said segment being provided with a dust-shelf 6 over the slots. The type strikes rearwardly against a-platen 7. Each typebar is a plate of thin sheet-metal having a longitudinal stiffening rib (not shown).

Extending upwardly from the base portion of the type-bar, towards the free end thereof, is a tongue 10, to contact with an abutment l1 on the front face of the segment 4, this abutment being of arc shape,

suitable for all the type-bars. The spring tongue may be formed by cutting a long kerf or slot 1:2 at the middle of the bar, at a widened portion thereof, said widened portion beginning at 13 just above the dustshelf 6. The tongue 10 may be of any required length, the arc of the abutment being made of smaller radius wherethe tongue is longer.

When the tongue strikes the abutment, there is springing action, beginning at the abutment and extending down through the tongue and then up along the type-bar to the type 9; the tongue and type-bar both having a springy construction. This gives a lengt of spring which is about equivalent to the entire length of the type-bar, and the type can spring'very much more than heretofore after the type-bar strikes the abutment, and there is more uniformity of type impression, and less need of securing the precise relation heretofore found necessary between the type, the platen and the abutment.

The abutment 11 is barely raised from the front surface of the segment This permits the axis of the middle body-portion of the type-bar to be more nearly coincident with a line drawn from the pivot to the type, thus tending to reduce liability of skewing and distortion of the type-bar at the moment of printing. The slotted portion of the segment projects far forwardly from the faceof the segment, and

the standing type-bar at its bottom portion,

bends in close to the front face of the segment, and keeps this close relationship for the rest of the distance to the type.

It will be understood, from Figure 3, that the type-bars, when printing, occupy various positions radiating from the printing point,

' according to the positions of the bars in the segment i. However, the types 9 must occupy vertical positions, and hence elbows are bent in the type-bars near their type ends, at 18, just below the usual fixed central type-guide 14. Taking the case of the extreme right-hand type-bar, at Figure 3, it will be seen that the. elbow-portion of the bar from the type down to the bend 18,

and from said bend to the abutment l1, stands considerably-to one side of an imaginary line drawn from the type to the point where the type-bar crosses the abutment 11, and all this portion of the bar has heretofore tended to continue in motion after the type is arrested by the piaten, thereby setting up a tendency of the type-bar to twist, with a consequent blurring of the type impression. To reduce or overcome this ditli culty, the spring tongue 10 is bent to the left from the type-bars on the right-hand side of the system, at Figure 3, with the result that the tendency of the elbowportionv of the bar to continue in motion or to twist, in the manner stated, is met by the resistance spring tongue itself.

offered by the engagbment of the offset spring tongue with the stop-abutment 11. In other words, the tendency of the elbowportion of the bar is to twist to the left, and this is overcome by the support which is offered at the left of the type-bar by the bent-out spring tongue, at Figure 3, the point of bending of the tongue being indicated at 15. One of the distinctions over previous type-bars is therefore that the point of arrest and support at 19 is set considerably over from the elbow-portion of the type-bar in a direction to overcome its tendency to twist at the instant of printing. As the type approaches the platen, the ofiset spring tongue 10 is first arrested by reason of its engagement with the abutment 11. The type and the main portion of the typebar are not arrested, however, but continue on because of their momentum, and since this final motion cannot take place about the pivot 2, it takes the nature of a bowing or whipping of the bar, with a tendency to twist towards the right, at Figure 3, or away from the point 19 where the spring tongue strikes the abutment 11. The momentum of the types 9 is taken up by the platen 7. The momentum of the elbow-portion of the type-bar, including the bend 18, tends to continue its advance towards the platen. Since at this true the bar is supported not only at its pivot but also at its type, this final springing of the type-bar can only be in the nature of a longitudinal twist of the bar towards the left; but this twist is powerfully opposed by the offset spring tongue 10, which is also at the left of the main p0rtion of the bar, and which at this time is under high tension and therefore effective to counteract the twisting tendency of the bar. Thus, by offsetting the tongue 10, there is first set up a tendency of the bar to twist to the right, which counteracts to a great extent the subsequent tendency of the bar to twist to the left; and the last-named tendency is also strongly opposed by the offset At Figure 1, it. will be seen that the tongues for the typebars at the left-hand portion of the system are bent to the right, inasmuch. as their type ends are bent to the left.

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

Having thus described claini:

1. The combination with a platen, of pivoted type-barto print against said platen and having an elbow or bend near its type end whereby the type stands at one side of the body of the bar, atype-bar stop-device, and a single tongue on the type-bar to engage said stop-device before the type touches the platen, said tongue extending from t e type-bar near its pivot portion towards it my invention, T

type end andbeing bent to the side of the type-bar opposite the type to counteract the twisting tendency due to the -torm of the type end of the type-bar.

2. The combination with a platen, of a type-bar to print against said platen and having an elbow or bend near its type end whereby the type stands at one side of the body of the bar, and means for checking the typing movement of said type-bar and counteracting the twisting tendency due to said elbow, comprising a tongue formed by a longitudinal kert in said type-bar and bent to the side opposite the type and a typebar stop to be engaged by said tongue just before the type-bar engages the platen.

3. The combination with a platen, of a plurality of radially-arranged pivoted typebars, each having an elbow or bend near its type end whereby the type stands at one side of the body of the bar, means to guide the type-bars laterally attheir pivots, a type-bar guide to be engaged by the free ends of all the type-bars, a type-bar stopdevice about midway between the pivots of the type-bars and the type-bar guide, and a single resilient stop-device-engaging tongue on each type-bar having an elbow, the tongues joining the type-bars in proximity to said lateral guiding means and extending to the sides of the type-bar opposite the types to counteract the twisting tendency due to the elbows at the type ends of the type-bars.

4. A pivoted type-bar formed of thin metal and having near its type end an elbow or bend whereby the type stands at one side of the body of the bar, and near its pivot portion a single integral tongue extending towards its free end, and a stop to be engaged by the free end of the tongue just before the type strikes the platen, the typebar and the tongue being both resilient, to permit the type to spring to the platen after such arrest, and the tongue being bent in a direction opposite to the. direction of the bend at the type end of the type-bar to counteract the twisting tendency due to the bend at the type end.

5. The combination with a platen, of a type-bar to swing against the platen, said type-bar having an elbow or bend near its type end whereby the type stands at one side of the body of the bar, and arresting means to engage the bar between its ends and at one side only of the body of the type-bar, when the type reaches the proximity of the platen, to control the twisting tendencyof the typebar, so as to cause the type onv the bent end of the type-bar to strike the platen properly.

6. The combination with a platen, of atype-bar to swing against the platen, said type-bar having an elbow or bend near its type end whereby the type stands at one side of the body of the bar, and arresting means to engage the barbetween its ends and only at the side of the body of the typebar opposite the type, when the type reaches the'proximity of the platen.

7. The combination with a platen, of a type-bar to swing against the platen, said type-bar having an elbow or bend near its type end whereby the type stands at one side of the body of the bar, and arresting means to engage the bar between its ends,-

when the type reaches the proximity of the platen, the portion of the type-bar for enagement with the arresting means being bent to the opposite side of the type-bar from the type.

8. Th combination with a platen, of a type-bar to swing against the platen, said type-bar having an elbowor bend near its type end whereby the type stands at one side of the body of the bar, and arresting means -to engage the bar between its ends, when the type reaches the proximity of the platen, a portion of the type-bar being bent to the opposite. side of the type-bar from the type, to engage said arresting means,

said offset portion being in the form of a tongue extending laterally from and longitudinally of the type-bar.

9. The combination with a platen, of a type-bar to swing against the platen, said type-bar having an elbow or bend near its type end whereby the type stands at one side of the body of the bar, and arresting means to engage the bar between its ends when the type reaches the proximity of the platen, said type-bar having a singleottset portion to engage said arrestingmeans, said offset portion being bent to the opposite side of the type-bar from the type, and being in the form of a tongue extending laterally from the type-bar, both the type-bar and the tongue being resilient.

WILLIAM F. HELMOND.

-Witnesses EnwARnAMEnMAN, WILLIAM P. SMITH.

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