US2057427A - Retarded electric interrupter and switch - Google Patents

Description

1936' A. GIORDANI ET AL 2, 57,

RETARDED ELECTRIC INTERRUPTER AND SWITCH Filed Fb. 21, 1955 Patented d. 13, I936 unrrap STATES RETARDED Ema-rare INTERRUPTEB AND swrron Aldo Giordani and Aronne Giordani, Padua, Italy Application February 21, 1935, Serial No. 7,591 In Italy February 21,1934

2 Claims.

This invention relates to retarded electric interrupters and switches in which the time for which the circuit is opened or closed is predetermined at will by means of a rotary disk as used in the art of automatic telephony. The object of the invention is to set the time of contact and the winding up of the mechanism by one single operation of the said disk. The device made in accordance with the present invention is especially designed for photographic purposes, but of course the device may be employed in any case where a delayed action interrupter or switch is recommendable, especially when the setting of the delay is frequently varied.

The invention is illustrated by way of example in the annexed drawing in which a switch made in accordance with the invention is shown.

Figs. 1 and 2 are a front and a side view of the apparatus respectively. Fig. 3 is a sectional view 20 taken along the line III-411 of Fig. 2. Figs. 4 and 5 show the rear of the apparatus, Fig. 4

illustrating the switch in its ordinary position,

Fig. 5 its position during the operation of switching, and Fig.6 shows the drive by a falling weight 25' instead of a spring.

The apparatus substantially comprises three principal parts: a dial or selecting disk i, an interrupter or switch 2, and a system of gears 3.

The dial or selecting disk I is entirely similar 30 to such used in automatic telephones. The numbers corresponding tothe units of time to be selected are engraved beside the openings. A finger is inserted into one of the openings, and then the disk is rotated until the finger touches 35 the abutment 4. Thelatter is not rigidly fixed, but is movable under a certain pressure against the action of a spring! so that the disk, after the abutment has been touched by the finger may berotated a little farther whereby half a unit of time is added.

The dial l is rigidly secured to its shaft 5 journaled in two plates 1 and 8 which are held together by bolts 9, thus forming the frame of 'the apparatus A spiral spring Ill adjacent to'the 45 plate 1 is fixed with one of its ends to this plate and with the other end to the shaft 6. Therefore by rotating the dial l and therewith its shaft 6 the spring I0 is wound up.

The shaft 6 projects from the frame plate 8 and has a plate ll rigidly secured to it and carrying at one side a coniifizt holder i2 and at the other side's. lever l3 freely rotating around its axis II.

a movable contact 2 forming the interrupter or This lever li is connected at its upper end with a'pa'wl l5 and carries at its lower end switch which according to its position bridges either the contacts a and b or the contacts 11 and 0 carried by the contact holder l2.

A spring l6 retains the lever l3 as well as the movable contact 2 in their normal positions. Another spring 11 maintains the desired pressure between the movable contact 2 and the contact holder l2. Finally, as soon as, owing to the rotation imparted to the dial, the end 20 of the pawl l5 has left the pin 2| a third spring I! presses the pawl l5 down so as to engage the cog wheel l9, located thereunder and offering a certain resistance to rotation.

The cog wheel is already forms part of the system of gears 3, because this wheel, even when free to rotate independently of the shaft 6, remains rigidly connected by means of the socket 22 (passing through plate 8) with the other cog wheel 23 which is just the first of the series of regulating gears 3. The latter are not described, as they are analogous to the common gears used in the mechanism of a time-piece.

The whole gearing 3 described above is to control, in addition to the function of regulating the velocity ratio of rotation, the speed during the releasing phase for which purpose it is provided with an anchor carrying a counter-weight 24 to efiect the desired speed.

The operation of the apparatus two steps:

After having selected the desired length of time, the operator puts his finger. into the opening of the dial I marked with the corresponding number, then he turns the dial from the normal or starting position shown in Fig. 4 until the finger touches the abutment l (or until the spring 5 is compressed) whereby the operated position shown in Fig. 5 is reached. During this rotation is divided into the'spring ill will have been wound up, and at the same time the pawl IE will have passed as many teeth of the cog wheel 19 as half-units of time were predetermined. On releasing the dial, the second step of the operation is automatically initiated, viz. the interruption or releasing phase. The spring l0 transfers its energy by the axis 6 to the plate H and the lever I3, and thereby to the pawl l5 whereby the cog wheel I9 and the whole system of gears 3 regulating the rate of release are made to rotate. The pawl [5 by transmitting its power to the cog wheel l9 forces the lever Hi to turn around its axis ll so that the movable contact 2 bridges the contacts I) and c can'ied by the contact holder 12.

The whole apparatus as above described now remains unchanged until the spring I0 is nearly released; and before the release is completed, the projecting end 20 of the pawl II meets the pin 2| and forces the pawl itself to disengage the cog wheel iii. The pressure of the pawl on the cog wheel now having ceased, the lever l3 returns under the action of the spring l6 into its position of rest, taking along the movable contact 2 andthus opening the circuit which up to this moment was closed by the contacts carried by the holder l2.

During the period referred to above the dial I will have slowly recovered its position of rest, and the apparatus is anew ready for use immediately after the second step of the operation has been completed.

It is obvious that other appropriate systems may be substituted for the herein described systerns of contacts and contact holders without departing from the gist of the invention. For instance, the above-described lever It could be replaced by one of the types of common mercury lnterrupters or commutators because this lever is perfectly lit for operating the said devices. On the other hand, the spring Ill may be replaced by another driving means, i'or instance, by a falling weight as in a clock, as shown in Fig. 6, in which a sprocket'wheel is mounted on the axis 6 and a chain 26 is wound around the said sprocket wheel and carries a weight 21.

We claim:-

1. Apparatus for interrupting an electriccurrent for a predetermined time comprising a frame, a rotary dial, a central shaft rigidly connected therewithand iournaled in the said frame, a spring connected at one of its ends to the said shaft and at its other end to the said frame, a

displaced so as to touch part of the said contacts.

a pawl resiliently secured to the said bridge and adapted to engage a cog-wheel loosely mounted on the said shaft so as to offer a certain resistance against rotation, the said cog-wheel being driven by the said pawl in the same sense, as the dial is driven by the first-named spring, and an abutment disengaging the said pawl after the dial has returned to its normal position.

2. Apparatuslfor interrupting an electric current for a predetermined time comprising a frame, a rotary dial, a central shaft rigidly connected therewith and journaled in the said frame, a spring connected at one of its ends to the said shaft and at its other end to the said frame, a plate rigidly connected with the said shaft, a number of contacts secured to the said plate, .a lever rotatably mounted on the said plate, a movable contact carried by the said lever, a spring tending to press the movable contact against a number of the first-named contacts, a spring tending to turn the said lever in the same sense as the first-named spring turns the dial, a pawl resiliently secured to the end of the said lever and adapted to engage a cog-wheel loosely mounted on the said shaft so as to offer a certain resistance against rotation, the said cog-wheel being driven by the said pawl in the same sense as the dial is driven by the first-named spring, and an abutment disengaging the said pawl after the dial has returned to its normal position.

ALDO GIORDANI. ARONNE GIORDANI.

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