US2427694A

US2427694A - Hand-position indicator for typewriters

Info

Publication number: US2427694A
Application number: US620023A
Authority: US
Inventors: Sieurin Sven
Original assignee: Atvidabergs Industrier AB
Current assignee: Atvidabergs Industrier AB
Priority date: 1944-10-10
Filing date: 1945-10-03
Publication date: 1947-09-23
Anticipated expiration: 1964-09-23

Description

Sept. 23, 1947.

s. SIEURIN HAND POSITION INDICATOR FOR TYPEWRITERS Filed Oct. 3, 1945 I N VEN TOR MW'W/J B2 @ZLT Patented Sept. 23,1947

HAND-POSITION INDICATOR FOR TYPEWRITERS Sven Sieurin, Stockholm, Sweden, assignor to Aktiebolaget Atvidabergs Industrier, Atvidaberg, Sweden, a corporation of Sweden Application October 3, 1945, Serial No. 620,023 In Sweden October 10, 1944 7 Claims.

When persons are instructed and trained in ypewriting they incessantly must be told not to lower their hands and wrists but to hold them so high that the fingers are directed down against the keys.

The present invention has for its object to provide in typewriters a device for indicating the position of the hands when lowered, so that it is automatically pointed out to the typewriting person and to the teacher when the wrist of a hand is held too low and, thus, the position of the hand immediately can be corrected.

Another object of the invention is to provide a highly sensitive construction of a control device of said type, so that this device is actuated even by a light touch of the hand.

Still further objects will appear from the following description of a preferred embodiment, by way of example illustrated in the annexed drawing, in which:

Fig. 1 shows diagrammatically a plan of a typewriter provided with a device according to the invention;

Fig. 2 shows a longitudinal section through a left hand portion of the control device;

Fig. 3 shows a longitudinal section through a right hand portion of the control device.

The typewriter may be of any kind. In Fig. 1 only the outlines of some main details are indicated, viz. the platen at I the rockable cover at 2, the frame at 3 and the keyboard at 4.

The device for indicating the position of the hands when lowered, comprises, according to the invention, an electric indicating element, a circuit for supplying electric energy to said indicating element, and a circuit controlling member mounted yieldingly in front of the keyboard of the machine-to close said circuit when depressed by the wrist of a lowering hand.

This control member may be formed as an U- shaped fork, the middle portion of which extends horizontally in front of the machine, the two lateral end portions of this fork being mounted on the frame of the machine, preferably in an adjustable way so that the position of said middle portion in relation to the keyboard can be adjusted in vertical or horizontal direction or in both these directions.

The middle portion of said U-shaped control fork consists of two concentric cylindrical spiral springs 6 and 7, made of an electrically conducting material, such as steel, bronze or the like, and constituting electric contacts. The two end portions of said fork, which end portions serve as holding members for said springs, consist of tubes 8 which also are made of steel, bronze or the like and the ends of which are bent towards each other. Around these ends of the two tubes the outer spring 6 is securely mounted and in the interior of each one of the same tube ends an insulating body 9 is mounted (see Figs. 2 and 3). These insulating bodies have extensions in the shape of concentric studs 9 upon which the inner spring 7 is attached. Thus, the two springs are insulated from each other when they are in stretched condition.

The lateral tubes 8 of the control fork are mounted on the frame of the machine by means of fastening members If]. These members may consist of U-shaped or angular brackets which are mounted beneath the side portions of the frame of the machine in such way that the vertical portions of said U-shaped brackets are in contact with the lateral surfaces of the frame. Each bracket may be fixed to the machine frame by means of a screw I l which has a knurled head I l and also carries two jam discs l2, l3 for the lateral tube 8. These jam discs may have diametrical grooves for the tubes 8. The contact surface between the bracket l0 and the inner jam disc i2, may be milled.

The innner spring I is electrically connected with one end of a wire strand I6 which is passed through a channel in the insulating body 9 of one of the tubes 8 and further through this tube to an electric indicator or signal element in the form of a lamp I8 which, preferably, is mounted on the front side of the machine above the keyboard, for instance, inside a window in the rockable cover 2 usually arranged over the type-levers. From this lamp the circuit runs to one of the poles or terminals of a battery 20, for instance, located in the machine. This battery may be a cell of the type normally used for electric torches. The other terminal of said battery is connected with the machine frame which, thus, together with one of the tubes 8 constitutes one of the two branches forming the electric circuit.

Evidently, the outer spring 6 will yield for even the lightest touch and will then electrically engage the inner spring 'I, so that the circuit over the lamp I8 is closed. When the lamp is lighted the attention of the writing person is called to the fact that he holds the hands in a non-correct position and, thus, he immediately can correct the position of the hands. Also the teacher will observe the signal from the lamp. Of course, also an acoustic signal device may be used instead of the lamp, for instance electric bells, buzzers or the like, or other electrically actuated signal or indicator devices.

The device according to the invention can easily be mounted on machines already in use, the holding device being made in correspondence to the type of machine in question. However, the device according to the invention can be incorporated in the machine even by the manufacturer of the same.

What I claim is:

1. In typewriters, a device for giving an alarm when the hands and wrists are lowered, comprising, in combination, an electric alarm element, a circuit for supplying electric energy to said alarm element, and a circuit control member mounted yieldingly in front of the key-board of the machine to close said circuit when depressed by the Wrist of a lowering hand, said control member extending laterally along the whole front side of the key-board.

2. In typewriters, a device for giving an alarm when the typist lowers her wrists, comprising, in combination, an electric alarm element, a circuit for supplying electric energy to said alarm element, two electric contacts in said circuit, said contacts being suificiently long to extend laterally along the whole front side of the key-board, and means for mounting said contacts in front of the key-board of the machine parallel to each other and one above the other, at least the upper of said contacts consisting of a spring deformable to engage the lower contact when depressed by the wrist of the typists hand.

3. In typewriters, a device for indicating the position of the hands when lowered, comprising, in combination, an electric indicating element, a circuit for supplying electric energy to said indicating element, two lateral holders attached on the frame of the machine and extending to points in front of the keyboard of the same, two electric contacts in said circuit, which contacts consists of two cylindrical spiral springs concentrically extending between said holders, and insulating means in said holders to insulate said springs electrically from each other, the outer one of said springs making contact with the inner one when depressed by the wrist of a lowering hand.

4. In typewriters, a device for indicating the position of the hands when lowered, as claimed in claim 3, comprising, in combination, also the feature that said holders are adjustably mounted in the frame of the machine to allow adjustment of the position of the springs in relation to the key-board of the machine.

5. In typewriters, a device for indicating the position of the hands when lowered, as claimed in claim 3, comprising, in combination, also the features that said holders consist of metal tubes the end portions of which are bent towards each other and carry externally the outer spring, and that said insulating means consist of insulating bodies arranged in said tubes and carrying the inner spring.

6. In typewriters, a device for indicating the position of the hands when lowered, as claimed in claim 3, comprising, in combination, also the features that the outer spring is connected to one terminal of an electric source over the holders and the frame of the machine, and that the inner spring is connected to the other terminal of said source over a wire strand located in one of said holders, the electric indicating element being connected between said electric source and said wire strand.

7. In typewriters, a device for indicating the position of the hands when lowered, as claimed in claim 3, comprising, in combination, also the feature that said electric indicating element consists of a lamp mounted on the front side of the machine above the key-board.

SVEN SIEURIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number