US1937047A - Typewriting machine - Google Patents

Description

Nov. 28, 1933. R. G. THOMPSON TYPEWRITING MACHINE Filed April 30, 1930 3 Sheets-Sheet l I Wall/11111111111 Nov. 28, 1933. R G TH P N 1,937,047

TYPEWRITING MACHINE Filed April 50, 1950 I 3 Sheets-Sheet 2 I I C I ///////I///////// I l I & If I 64 .INVENTOR 721's ATTORNEY Nov. 28, 1933.

R. e. THOMPSON TYPEWRITING MACHINE Filed April 30, 1930 5 Sheets-Sheet 3 mvau ma RgsseZGT/l Q Zia ATTORNEY Patented Nov. 28 1933 TYPEWRITING MACHINE Russell G. Thompson, Rochester, N. Y., assignor to Electromatic Typewriters,. Inc., Rochester,

N. Y., a corporation of New York Application April 30, 1930. Serial No. 448,564

2 Claims.

This invention relates to typewriting machines, and particularly to power driven means for operating the type action of such machines.

The principal object of .this invention is to provide power means for moving the type bars into engagement with the platen in a typewriting machine of the so-called noiseless type, in which the type bars are arranged radially with respect to the printing point and move in substantially straight lines to and from said printing point.

Another object of the invention is to provide power means for moving the type bars into engagement with the platen, said type bars being carried on swinging arms or, supports, whereby they move bodily to and from the platen in substantially straight lines.

Still another object of the invention is to provide power means for tilting a type bar of this kind having a plurality of printing characters to aline a selected character with the printing point on the platen.

A still further object of the invention is to provide power means for moving the type bars to the printing position in a typewriting machine of the noiseless type and having a plurality of type thereon arranged in groups, a key lever associated with each of said groups, at least one of which key levers controls means for tilting the type bar to print from a selected group of type, interlocking means being provided between said key levers for preventing the actuation of one of said keylevers when another is actuated.

Still another object of the invention is to provide means in a bodily movable type bar for 35 impressing 'the upper case type on the work with greater force than the lower case type.

To these and other ends, the invention consists in the construction and arrangement'of parts that will appear from the following description when read in conjunction with the accompanying drawings, the novel features being pointed out in the claims following the specification.

In the drawings:

Fig. 1 is a transverse section of a typewriting machine illustrating one embodiment of the invention, parts being brokenaway and others shown in section;

Fig. 2 is a similar view showing the type bar in position to print from its lower group of type;

Fig. 3 is a similar view showing the type bar in position to print from its upper group of type;

Fig. 4 is a fragmentary view showing means for rendering the type bar tilting means inoperative;

Fig. 5 is a fragmentary front elevation of the key lever guide, showing the interlocking means between key levers, and

Figure 6 is a fragmentary view similar'to Fig. 4 showing parts in another position.

Referring particularly to the drawings, in which like reference numerals refer to the same parts in all the figures, there is illustrated a typewriting machine of well known noiseless type, in which the type bars 1 are arranged radially about the printing point on the platen 2 and move bodily in substantially straight or slightly curved paths to and from the printing point to engage the platen or a work sheet thereon. Each of the type bars carries four types arranged in vertical alinement in groups 3 and 4 of two types each, corresponding to upper and lower case, each type bar being operable by either one of two keys 5 and 6, associated therewith and corresponding in number to the number of groups of characters on the type bar or the number of characters in each group, one of which is adapted to set in operation instrumentalities for tilting the type bar to select the particular group to be printed, while the platen is shiftable in the usual manner to bring its printing point into the path of the particular type selected to be printed. The platen 2 is rotatably mounted in a carriage adapted to move transversely on the frame 7 for letter and word spacing, as usual in this art.

Each of the type bars is carried on supports comprising links 8 and 9 pivoted to the bar, the link 8 being pivoted at 10 adjacent its rear end or head. The link 8 is mounted to swing on a pivot 11 carried on a swinging member or lever 12, while the link 9 turns on a pivot 13 mounted in a bracket fixed to the frame of the machine. The swinging member 12 is in the form of abell crank lever carried on a fixed arm 14 mounted on the frame of the machine for limited adjustment thereon. When the type is actuated to move to the printing point from the Fig. 1 to the Fig. 2 position, it moves bodily in a slightly curved path on the pivoted links 8 and 9 and is held against lateral thrust by the guiding member 15 in which it moves.

The path in which the type bar moves is slightly curved or has a long radius of curvature, and due to the changed position of the link 8 relative to the link 9 when printing from the upper group oftype, the curve of the path is reversed, although of the same general character. In order to swing the bell crank 12 to the Fig. 3 position to print from the upper group of types, the bell crank is pivotally connected at 19 with a link 18 pivotally connected with an actuator 20 1'! the form of a bell crank lever pivoted at 21 to a bracket on the frame of the machine. A fixed stop 20 on the reverse side limits the movement of the actuator in both directions, see Figs. 4 and 6.

The arrangement of the lever 20 and link 18 is such as to form a toggle normally held in the straight line position of Figs. 1 and 2 by the engagement of the lever 20 with its fixed stop, when printing from the lower group of characters on the type bar. The forward end of the lever 20 has an actuating link 23 pivoted thereto, whereby it may be moved to the other extreme limit of its movement to move the parts of the toggle to the Fig. 3 position and swing the link 8 and the rear end of the type bar downwardly to print from its upper group of type. The link 23 may be actuated by a key lever, but in the present instance power driven means are provided for actuating it.

Pivoted on the stud 21 concentric with the lever 20 is a second bell crank lever or actuator 24 which is also power operated through the link 25'pivoted thereto. A link 26 is pivoted to the actuator 24 and connects it with one arm of a lever 27 pivotally mounted on a fixed bracket 28. The other arm of said lever is ofiset and extends to the opposite side of its support where it is provided with an arm 27' adapted to engage the actuator 20 and prevent actuation thereof when the link 25 is operated to print from the lower group of type, see Fig. 4.

A main driving lever 30 is pivoted at 31 on a fixed bracket. Said driving lever is a bell crank in type and constructed of two identical parts spaced from each other, and each having a rearwardly and downwardly curved arm 32, said arms being connected by a plate 32' underlying the forward ends of the actuators 20 and 24. The forward ends 33 and 34 of said actuators are similar in shape, each having a curved portion adapted to contact the arm 32 and swing the main driving lever on its pivot when one or the other of the actuators 20 or 24 is actuated by one of the links 23' or 25. At its upper end the lever 30 is connected by means of a link 36 with a bell crank lever 37 pivoted at one end on a fixed bracket and pivotally connected at its other end with the forward end of a link 38 pivotally connected at its rear end with the type bar 1. The lever 37 and link 38 constitute in effect a toggle so that when the lever 30 is operated by one or the other of its actuators from the Fig. 1 to the Fig. 2 or Fig. 3 position, they move to the substantially straight line position shown in the latter views, the parts being so adjusted that the toggle straightens with consequent slowing up of its motion just as the type bar contacts with the surface of the platen.

In order to provide means for fully straighten ing the toggle to press the type into contact with the platen, a weight 40 is'provided on the end of the link 36 which is normally arranged in front of the lever 30, as seen in Fig. 1, but swings forwardly over the lever 30 with the type bar to the Fig.2 position and gains momentum to move the parts of the toggle to the straight position shown in said Fig. 2. In order to insure complete return movement of the parts to the Fig. 1 position and prevent rebound, a link 41 is loosely pivoted to the weight 40 at one end and to a link 42 at its other end. The link 42 is pivoted to a fixed part and with the link 41 constitutes a toggle normally in the straight position shown in Fig. 1. When, however, the type bar is actuated to print, the parts of the toggle assume the position shown in Fig. 2 and serve to absorbv the momentum of the weight on the return movement. The link 41 is provided with a stop arm 43 adapted to engage a stop 44 on the weight to prevent rebound on the return stroke. This toggle formed by the links 41 and 42 serves to absorb the momentum of the parts on the return movement and causes them to come to rest in a noiseless manner.

Pivoted to the lower part of the lever 30 is link 45 bifurcated at its lower end to straddle and engage a universal bar 46 for operating the escapement or other devices, as usual in the art. The lever 30 is also provided with an integral arm 47 projecting forwardly therefrom and adapted to engage a fixed stop 48 to limit its turning movement. The stop 48 may be provided with a resilient pad 48' of felt or soft rubber to render the engagement therewith of the arm 47 substantial ly noiseless. A second stop 40 is arranged on the frame member 7 in the path of the weight 40. The stop 40 is also constructed of soft resilient material. By this arrangement, it will be noted that the stop 48' is a noiseless stop for limiting the movement of the toggle 37, 38 and the type bar and parts movable therewith in one direction, and the stop 40' is a noiseless stop for limiting the movement of said parts in the other direction.

The essential features ofthe parts thus far described are substantially those of a well known noiseless typewriting machine and form no part of the present invention except as they enter into combination therewith.

According to the present invention, power driven means are provided for actuating one or another of the links 23 or 25 selected by the actuation of one or another of the corresponding key levers 5 or 6. To this end, the links 23 and 25 are respectively pivotally connected with actuators 50 and 51, mounted in the base of the machine. The actuators 50 and 51 are similar in construction except that they are arranged to extend in opposite directions from the lower ends of the links. It is therefore believed that a de tailed description of one will suffice.

The actuator 51 is in the form of a bell crank lever pivoted at' 53 to the frame of the machine. It has an arm 54 extending rearwardly from its pivot, to the rear end of which the link 25 is pivoted at 55. It also has another arm 56 extending downwardly from the pivot 53, on the lower end of which a cam 57 is rotatably mounted at 58, which cam normally lies closely adjacent the surface of the driven roller 59 but is adapted to move into frictional engagement therewith to posed lugs 64, one or the other of which is normally engaged by a stop lever 65 having a lateral projection 66 on one of its arms adapted to engage one or the other of the lugs-64 to stop the 1 cam and retain it against actuation by the spring fingers The other arm of the stop lever has a laterally projecting lug 67 adapted to be engaged ,by the forked end 68 of one of the key levers,

case type against the platen. when, however, the platen is moved or shifted relatively to the type bars, the upper case type is impressed on the platen or the work sheet thereon. The forward movement of the type bar is substantially uniform at each actuation, due to the action of the toggle by which it is actuated. By an inspection of Fig. 1, it will be noted that the upper case type 3" of each group is raised from the face of the type bar to a greater extent than the lower case type 3 so that when the toggle which actuates the type bar is straightened, the upper case type projects beyond the plane of the lower case type to engage the platen or the work sheet thereon with greater pressure when the toggleis straightened, By this construction, the .upper case types may be impressed on the work sheet with the same weight per unit of area as the lower case types, although of comparatively greater area.

The operation briefly stated is as follows: The parts are normally in position to print from the lower group of type on the type bar. When the key lever 5 is depressed, as shown in Fig. 2, the

stop lever 65 connected therewith ismoved fromengagement with its lug 64 on the cam 57, thus permitting the cam to rotate under the action of its spring finger 62 into engagement with the driven roller 59, which is frictionally engaged thereby. The cam is then rotated by the roller and turns the actuator on its pivot and depresses the link 25 connected therewith, thus swinging the actuator 24 to lock the other actuator 20 and swing the .lever 30 to move the type bar to the printing point.

' When the other key lever 6, also adapted to actuate the type bar 1, is depressed, as shown in Fig. 3 to print from the upper group of type, the companion actuator 50 is operated in substantially the same manner as the actuator 51 to depress the link 23 and move the actuator 20 which swings the lever 12 and through it the supporting lever 8 to move the rear end of the type bar downwardly to bring its upper group of type to the printing point. During such movement the type bar swings on the link 9. Said actuator 20 also engages and swings the lever 30 to move the type bar to the printing position.

When the type action is operated rapidly by power. there is a tendency of the parts to drag and rebound. It has been found that this can be eflectively overcome by resiliently connecting the arm 32 of the lever 30 with the actuators 20 and 24 by means of retraction springs such as 73. which resiliently retain the lever 30 in its normal position.

It will be noted that two key levers 5 and 6 are associated with each of the type bars 1. In practice, it has been found that there is liability of an operator striking two keys associated with the same type bar at the same time. Should this occur, it would be likely to result in serious injury to the parts. To overcome this liability, means have been provided for engaging one of the key levers and preventing its actuation when the other is operated, thus preventing the simultaneous actuation of both key levers associated with the same type bar.

Referring to Fig. 5 of the drawings, it will be noted that the key levers engage verticallyarranged slots 75 in a fixed member or comb '76, which serves to guide their movements to vertical planes. The key levers 5 and 6 associated with any one of the type bars 1 are arranged in adjacent slots '75, and pivoted on the rear face of the comb 76 midway between the adjacent slots are locking members '77 which project laterally from their pivots beneath the adjacent key levers which are associated with one of the type bars and over the slots in the comb in which said key levers are guided. The locking members 7'7 are pivoted intermediate their ends so that they normally occupy a horizontal position under the action of gravity; When one or the other of the key levers 5 or 6 is actuated, it engagesone end of the locking member and swings it on its pivot out of the path of the key lever, and when the key lever is released and returns to normal position, the locking member also swings back to its normal position under the action of gravity. If both key levers are struck simultaneously, neither can be actuated a distance suificient to actuate the type bar, since both key levers simultaneously engage the locking member on opposite sides of its pivot and each key lever prevents it from swinging out of the path of the other.

Although only one embodiment of the invention is shown and described herein, it will be understood that this application is intended to cover such changes or modifications as come within the spirit of the invention or scope of the following claims.

I claim:

1. A type action for typewriting machines, comprising a bodily movable type bar, a plurality of groups of type thereon, key levers associated with said type bar and corresponding in number to the number of groups of type, an actuator operatively connected with each of said key levers, a bell crank lever operatively connected with the type bar for moving it to the printing point and having a part arranged in the path of said actuators, power operated means controlled by the depression of any of said key levers for moving the type bar to the printing point, and resilient means connecting said bell crank lever to. the actuators.

2. A type action for typewriting machines, comprising a bodily movable type bar, a plurality of 125 groups of type thereon, key levers associated with said type bar and corresponding in number to the number of groups of type, movable means on which said type bar is supported, an actuator operatively connected with one of said key levers 130 and with said movable means for tilting the type bar, a second actuator operatively connected with another of said key levers, a bell crank lever operatively connected with the type bar for moving it to the printing point and having a part arranged in the path of said actuators, power operated means controlled by the depression of any of said key levers for moving the type bar to the printing point, and resilient connections between said

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