US2331639A - Time switch - Google Patents

Description

Oct. 12, 1943, T, G, TgGERsTEDT 2,331,639

TIME SWITCH Filed Sept. 16, 1942 Patented Oct. 12, 1943 TIME SWITCH Tor Gran Tigerstedt, Stockholm, Sweden, as-

signor to Aktiebolaget Esco Skandinaviska.

Companiet fr Utrikeshandel, Malmo, Sweden,

a corporation of Sweden Application September 16, 1942, Serial No. 458,545 In Sweden June 11, 1942 Claims.

The present invention relates to time switches of the type wherein an electrical circuit is closed by relative movementl of a contact pin or the like and a perforated disc covering a contact surface. The invention is particularly characterized by the feature that the said relative movement is composed of two different movements, one of which is a circling movement and the other of which is a movement occurring crosswise to the circling movement.

The object with this arrangement is that the contact pin shall always describe a new path upon the perforated disc and thus not move along the same path as before after the elapse of twenty-four hours. According to the invention it is possible by means of a single perforated disc to control switchings at any desired hour during long periods, for instance one or more weeks. The device is primarily intended as an automatic switch for radio receivers for which the entertainment schedules are generally published one week in advance. It is the intention that unperforateddiscs shall be supplied so that the owner of a time switch constructed according to this invention shall be able at the beginning of a new week to stamp out from the disc holes at the hours at which is desired that the radio receiver shallbe automatically switched on.

The invention is described in the following with reference to the accompanying drawing which shows diagramatically a preferred embodiment of the new time switch.

Numeral I designates a pointer shaft driven from the mechanism of a clock (not shown) which pointer shaft makes a complete revolution in twenty-four hours. The shaft I extends through a pinion 2 fastened to a suitable support so that it does not partake of the rotation of the shaft I. An arm 3 is mounted on the shaft I, and the free end of this arm is provided with a slot, as shown at 4. In the slot a sliding block 5 is movably mounted and this block carries a contact pin 6. In the arm 3 bearings are provided for a shaft I upon which a gear 8 meshing with the pinion 2 is fixed. The shaft I also carries a cam disc 9 having a helical contour. The contact pin 6 is urged against the edge of this cam disc by means of a spiral spring I0 extending between the sliding block and a xed point on the arm 3.

The contact pin 6 moves over a stationary metal plate II which is covered by an insulating disc I2 of paper or other suitable material provided with a line-pattern and with suitable text, of which disc only a fragment is shown. The

line-pattern on the paper disc consists of a helix or spiral-line I3 arranged near the periphery of the disc and comprising eight full windings between which are formed seven narrow helical bands I4 corresponding to the seven days of the week, further of twenty-four radial lines I5 arranged at equal distances and corresponding to the hours of the day, and nally of radial tenminutes lines I6 arranged between adjacent hourlines.

A contact spring I'I is shown bearing on the rotatable shaft I whereby it is also electrically connected to the contact pin 6. From the contact spring II the circuit leads through a source of current I8 to an electromagnetic relay I9 and from hence to the metal plate I I,

When the pointer shaft I of the time switch rotates in the clockwise direction and turns the arm 3 so that the gear 8 performs a planetary movement about the fixed pinion 2, the gear 8 and hence the cam disc 9 will rotate in the clockwise direction about the shaft l. The speed ratio is so chosen that the shaft I will make seven revolutions in the same time as the shaft 'I makes one revolution. Since the contact pin 6 is urged against the edge of the cam disc 9 by the spring I0, the said pin will move in a helical path outwardly on paper disc I2 covering the metal plate I I in the space between the windings of the helix I3.

In the paper disc I2 apertures 2l) are made by means of a pair of punching-tongs, a stamp or other suitable tool in squares corresponding to the desired switching-on-times. In the drawing the apertures are marked with black. In the embodiment shown apertures are made at the following hours: Monday at 17.10, Wednesday and Thursday at 17.20 and Friday at 18.10. At these hours the contact pin 6 will contact the metal plate II and close the circuit through the relay IS so that the latter is actuated and in turn closes a circuit through the radio receiver (not shown) The relay I9 should preferably be of the type which after being actuated by an electrical impulse from the source of current I8 remains in the closed position until it is brought back by hand to the off position.

The metal plate II should be arranged so as to be easy of access, for instance by being removably mounted in the time switch or by being mounted on a hinged nap or the like. Furthermore it should suitably be provided with pins or other centering and orientating means for the paper disc I2 which in turn should be provided with corresponding apertures for the pins so that it will always be fastened to the metal plate in the proper position. When the time switch is used for the switching-on of a radio receiver it is intended that the owner of the time switch at beginning of each week shall make holes in a paper disc I2 corresponding to the hours of desired reception during the whole week whereafter the disc is fastened to the metal plate Il.

Other modifications are also possible.

What I claim and desire to secure by Letters Patent is:

1. In a time switch for automatic control of an electric circuit, a contact surface, a stationary perforated insulating member covering saidl contact surface, a rotatable arm, and a contact pin mounted for radial movement upon said rotatable arm.

2. In a time switch for automatic control of an electric circuit, a contact surface, a stationary perforated insulating disc covering said contact surface, a clock, a rotatable arm driven by said clock, a contact pin mounted for radial movement upon said rotatable arm, and a cam member adapted to actuate said contact pin and to move the same radially at the rotation of the rotatable arm.

said clock, a shaft carried by said rotatable arm,`

a cam disc having a helical contour mounted on said shaft, a gear mounted on the same shaft as the cam disc, a stationary pinion m'eshing with said gear, and a contact pin. mounted for radial movement upon said rotatable arm and adapted to be urged against the contour of said cam disc.

4. A time switch according to claim 3, wherein the contact surface is provided with means for fastening the perforated insulating disc to the same in a centered and oriented position.

5. In a time switch for automatic control of an electric circuit, a contact surface in said circuit, a perforated insulating sheet covering said contact surface, means for closing said electric circuit through a perforation in said member, and means for producing a continuous relative scanning movement in two co-ordinate directions between said closing means and said perforated member.

TOR GRAN TIGERSTED'I.

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