US1396329A - Typewriter - Google Patents

Description

A. KING.

TYPEWRITER.

APPLICATION FILED JAN. 14. I920.

- Patented Nov. 8, 1921.

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TYPEWRITER.

APPLICATION FILED JAN.14, 1920. 1,396,829, Patented Nov. 8, 1921.

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TYPEWRITER.

Specification of Letters Patent.

Patented Nov. 8, 1921.

Application filed January 14, 1920. Serial No. 351,501.

To all whom it may concern:

Be it known that I, ANsoN KING, a citizen of the United States, and resident of Boston, in the county of Suffolk and State of Massachusetts, have' invented new and useful Improvements in Typewriters, of which the following is a specification.

This invention relates to typewriters and more particularly to the type of machines known as noiseless typewriters which have the following characteristics. The type members are unconnected to the key members and are arranged to be given an initial impulse and then to carry on after the key members stop. The escapement bar is actuated by the type members and not by the key members. Consequently the key members are not attached to any of the operative mechanism of the machine but merely engage the key members to gave them an initial impulse. The movement of the key members is limited by a fixed stop, usually covered with a thin layer of antinoise material, and the key members are re turned to normal position by springs operative upon the members at all 13111188.

While machines of this type are 1n many Ways superior to other typewriters they have certain disadvantages which the present invention will overcome. For example, the type members, being unrestrained except by the light restoring springs, {are stopped in their downward movement by said stop so suddenly that the fingers of.

the operator receive shocks which are both unpleasant and injurious to the nervous system. Moreover, the restoring springs cannot be properly adjusted to produce satisfactory action for the reason that they are operative upon the key members throughout the entire cycle of movement and with substantially the same force. If the springs are adjusted to exert a light restoring force they do not unduly resist the downward movements of the keys, but they do not re turn the keys sufiiciently quickly to attain the necessary speed. And on the other hand if they are adjusted to exert a strong restoring force thereby quickly to restore the keys, they unduly resist the downward movement of the keys.

The objects of the present invention are to overcome the aforesaid difficulties-and to produce a typewriter of the type referred to which does not impart unpleasant and injurious shocks to the operator and which can be adjusted to afford an action which is hght and relatively untiring and at the same time remarkably quick.

The invention consists in providing auxiliary resilient means, in addition to the usual key restorin springs, for yieldingly and more gradua ly stopping the downward movement of the keys and for applying a kick-back to the keys at the beginning of their upward movement which greatly increases the rate at which they are restored to normal position.

While my improvement is particularly applicable to the well-known noiseless typewriters where the keys are unconnected to all the operative mechanism of the machine and where the keys only engage the type members during the first part of their movement, the invention may also be applied to advantage to other typewriters.

I have illustrated one particular embodiment of the invention in the accompanying drawings, in whichigure 1 is a schematic view of my improved typewriter with the key in normal position;

Fig. 2 is a similar view showing the key depressed; and

Fig. 3 is a perspective view of a detail of construction.

The drawings show a noiseless t pewriter having a base A, a frame 1%, a paper roll C, a top plate D, and a type bar guide E. The escapement mechanism comprises the escapement bar F supported by the links G, connected by the link H to the bar I, this bar operating the escapement mechanism in a manner not fully shown since it is not a part of the present invention. The key levers K are attached to the auxiliary arm 0 which are hung by their rear hooks to a tubular support L and their tension is adjusted by means of the screw M acting upon the springs'N. The auxiliary arms 0 are connected to the levers P by the links Q. The levers P have wiper sur aces which act upon the cam arms R of the rocker arms S. These rocker arms S are hung from adjustable brackets T, and operate the type bars U through a toggle motion which comprises a longer member V and a shorter member W which latter is connected to the rocker arm I by a link carrying a endulum Y. The escapement is operate by a fork Z pivoted to the rocker arm S.

.straightens out the toggle motion V-W as shown in Fig. 2. This causes the type bar U to register an impression. It is particularly pointed out, as is clearly shown in Fig. 2, that there is now no connection between the key and type bar, the lever P and cam arm B being out of contact. The forward motion of the upper arm of the rocker S caused by the pendulum Y causes the cam arm R to swing downward and in so doing it operates the escapement by means of the fork Z depressing the escapement bar F.

The structural embbdiment of my invention comprises a cushioned bar which as shown consists of the metallic channel member 4 and the resilient cushion 5 which are hung by a spring 6 from a bracket 7, the spring bein attached to a screw threaded member 8 w ich may be adjusted. relative to p the bracket by a wing nut 9. As shown in Figs. 1 and 2 the bracket is supported on the upper edge of the base frame A, but isto be understood that this is by way of illustration only as the bracket may be hung from any convenient fixed portion of the type writer. The tension of the springs of the stop-bar may be adjusted by turning the thumb nuts 9. The lower ends of the brackets 7 bear against the cushion 5 to maintain the barin its normal position.

The cushion element 5 serves to prevent a harsh click when the key strikes the bar and also when the bar rises again under the impulse of the spring and contacts with the lower end of the bracket 7 This'cushion is not essential to my inventionbut is desirable, especially when used in connection with a typrewriter which is intended to be noiseless. rom the foregoing it. will be apparent that the yielding stop-bar will gradually stop the ownward movement of the keys so as to avoid the sharp shock incident to typewriters of the type referred to. Moreover, the spring actuated stop-bar serves to kick-back the keys thereby affording an action which is remarkably quick. Owing to the fact that the springs of the stop-bar impart a quick return movement to the keys the usual key springs may be made very light thereby decreasing the resistanceto the downward movement of the keys. Indeed the key springs may be made so light that they merely hold the keys up afterthey have been restored by the stop springs, especially where the key springs are not required to restore the escapement bar or other operative parts of the machlne. Thus in menses the downward movement of the keys only a slight resistance is offered by the key springs until the keys reach substantially the end of their downward stroke, and then the stop-bar springs offer a high resistance I for a brief interval, thereby yieldingly stopping the keys and quickly returning them.

I claim:

1. In a typewriter, the combination with the key levers thereof, a stop-bar resiliently supported on fixed brackets, the bar in its normal position bearing against a portion of said brackets, and a cushion mem ber at said bearing points.

2. In a typewriter, the combination with the key levers thereof, of a stop bar resiliently supported on fixed brackets, the bar in its normal position bearing against a por= tion of the said brackets, the key levers being adapted. to bear upon said stop bar when depressed and to move said bar out of engagement with the bracket, said movement of the stop bar being adapted to cause the cushioned stop of the downward movement of the key levers.

3. In a typewriter, the combination with.

.the key levers thereof, of a stop-bar movably supported to limit the downward movement of the levers, a stop for limiting the movement of the bar in the direction opposite to the impacts of the levers thereon to hold the bar out of engagement with the levers in the normal position of the levers, and a cushion for softening the impact between said bar and said stop.

4 In a typewriter, the combination with the key levers, of a stop-bar for limiting the downward movement of the key levers, said bar being movable up and down, means for yieldingly urging said bar in the direction opposite to the impact of the levers thereon, a stop for limiting the movement of said bar in the opposite direction to hold the bar out of engagement with the levers in the normal position of the levers, and yielding means for softening the impact between said bar and said levers and stop.

5. In a typewriter, the combination with the key levers, of a stop-bar for limiting the downward movement of the key levers, said bar being movable up and down, means for yieldingly urging said bar in the direction opposite to the impact of the levers thereon, a stop for limiting the movement of said bar in the opposite direction, and yi elding means for'softening the impact between said bar and said levers and stop,said means comprising a single pad arranged to engage both the levers and the stop.

6. In a typewriter, the combination with the key levers of means for yieldingly countera-cting the downward movement of the bars near the limit of their strokes, said means including a stop-bar and a spring support therefor, said bar being disposed above the key levers, and stop members on the key levers overhanging said bar.

7. A typewriter comprising key levers, a yielding stop-bar for limiting the downward movement of the levers, said bar being disengaged from said levers in the normal position of the levers, means for yieldingly urging said bar in a direction opposite to the impact of the levers thereon, and means for adjusting said yielding means to different conditions of operation.

8. A typewriter comprising key levers, a stop-bar for limiting the downward movement of the levers, and a tension spring extending u )wardly from said bar for yieldingly pulling the bar upwardly, and a stop limiting the upward movement of said bar to hold the bar out of engagement with the levers in the normal position of the levers.

Signed by me at Boston, Massachusetts, this twenty-ninth day of December, 1919.

ANSON KING.

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